Methods and Results— ApoE^–/– mice were treated with TWEAK-inhibiting fusion protein, Fn14-Fc, in an early (5 to 17 weeks of age) or delayed (17 to 29 weeks of age) setting. In the aortic arch, Fn14-Fc as compared to control treatment resulted in advanced plaques which were smaller (early treatment), fewer (delayed treatment), lower in fibrotic content (early and delayed treatment), and exhibited an increased macrophage content and smaller macrophage size (delayed treatment). There were no differences in apoptosis in atherosclerotic plaques after Fn14-Fc versus control Ab treatment. However, blocking TWEAK resulted in less macrophage uptake of modified lipids in vitro.

Conclusions— Fn14-Fc fusion protein treatment did not prevent lesion initiation but inhibited some features of plaque progression and induced a unique advanced plaque phenotype with increased macrophage content and smaller macrophage size, which may be attributable to reduced lipid uptake. These findings indicate that TWEAK/Fn14 interactions regulate atherosclerosis and mediate lipid uptake in macrophages.

Methods and Results— LDLR-null mice receiving ritonavir were compared with those receiving ritonavir plus lipolysis inhibitor acipimox or vehicle alone to determine how acipimox would affect ritonavir-induced atherogenesis. Intermittent high-fat high-cholesterol diet was used to facilitate optimal atheromatous lesion development. Drug effects were assessed as changes in aortic lesion score, plasma lipid and lipoprotein profile, body fat mass, and insulin-induced suppression of plasma fatty acid concentrations. Ritonavir increased aortic lesions, in association with decreased body fat mass, impaired antilipolysis action of insulin, and increased proatherogenic plasma lipoproteins. All these adverse effects were attenuated by cotreatment with acipimox.

Conclusions— Our results provide the first direct evidence that supports the hypothesis that dysregulation of adipose lipolysis is an important contributor to the proatherogenic role of selected HIV protease inhibitors.

Methods and Results— Absence of Akt1 reduces VSMC proliferation and migration. Mechanistically, the proliferation and migratory phenotype found in Akt1-null VSMCs was linked to reduced Rac-1 activity and MMP-2 secretion. Serum starvation and stress-induced apoptosis was enhanced in Akt1 null VSMCs as determined by flow cytometry using Annexin V/PI staining. Immunohistochemical analysis of atherosclerotic plaques from Akt1^{–/–ApoE–/–} mice showed a dramatic increase in plaque vulnerability characteristics such as enlarged necrotic core and reduced fibrous cap and collagen content. Finally, we show evidence of myocardial infarcts and cardiac dysfunction in Akt1^{–/–ApoE–/–} mice analyzed by immunohistochemistry and echocardiography, respectively.

Conclusion— Akt1 is essential for VSMC proliferation, migration, and protection against oxidative stress–induced apoptosis. Absence of Akt1 induces features of plaque vulnerability and cardiac dysfunction in a mouse model of atherosclerosis.

Methods and Results— Cholesterol-rich diet feeding of miniature pigs was associated with an increase in PAFAH activity and an increase of the PAFAH to PON1 ratio. PLA2G7 RNA (coding for PAFAH) expression was increased in blood monocytes and plaque macrophages. Increased PAFAH activity was associated with higher plasma lysophosphatidylcholine and correlated with oxidized LDL. In THP1 monocytes and macrophages and in human blood-derived macrophages, oxidized LDL induced PLA2G7 RNA expression. Atherogenic diet feeding induced the accumulation of macrophages and oxidized LDL in the arterial wall leading to atherosclerosis. PAFAH activity correlated positively with plaque size and TNFalpha expression in plaque macrophages.

Conclusions— We demonstrated that an increase in PAFAH activity was associated with increased levels of lysophosphatidylcholine, oxidized LDL, and inflammation, resulting in accelerated atherosclerosis in hypercholesterolemic minipigs. The significant correlation between PLA2G7 RNA expression in plaque macrophages and plasma PAFAH activity suggests that the latter is a consequence, rather than a cause of macrophage accumulation. Our cell experiments suggest that oxidized LDL can induce PAFAH, resulting in accumulation of lysophosphatidylcholine that increases the inflammatory action of oxidized LDL.

Methods and Results— We generated human apoAII transgenic (Tg) rabbits, a species that normally does not have an endogenous apoAII gene. Plasma levels of human apoAII in Tg rabbits were 30 mg/dL, similar to the plasma levels in healthy humans. The expression of human apoAII in Tg rabbits resulted in increased levels of plasma triglycerides, total cholesterol, and phospholipids accompanied by a marked reduction in HDL-cholesterol levels compared with non-Tg littermates. Analysis of lipoprotein fractions showed that hyperlipidemia exhibited by Tg rabbits was caused by elevated levels of very-low-density lipoproteins (VLDL) and intermediate-density lipoproteins. Furthermore, postheparin lipoprotein lipase activity significantly decreased in Tg rabbits compared with non-Tg rabbits.

Conclusions— These results indicate that apoAII plays an important role in both VLDL and HDL metabolism, possibly through the inhibition of lipoprotein lipase activity. ApoAII Tg rabbits may become a new model for the study of human familial combined hyperlipidemia.

Methods and Results— ITX5061, a molecule initially characterized as a p38 MAPK inhibitor, increased HDL-C levels by 20% in a human population of hypertriglyceridemic subjects with low HDL levels. ITX5061 also moderately increased apoA-I but did not affect VLDL/LDL cholesterol or plasma triglyceride concentrations. ITX5061 increased HDL-C in WT and human apoA-I transgenic mice, and kinetic experiments showed that ITX5061 decreased the fractional catabolic rate of HDL-CE and reduced its hepatic uptake. In transfected cells, ITX5061 inhibited SR-BI–dependent uptake of HDL-CE. Moreover, ITX5061 failed to increase HDL-C levels in SR-BI^–/– mice. To assess effects on atherosclerosis, ITX5061 was given to atherogenic diet–fed Ldlr^+/– mice with or without CETP expression for 18 weeks. In both the control and CETP-expressing groups, ITX5061-treated mice displayed reductions of early atherosclerotic lesions in the aortic arch –40%, P<0.05), and a nonsignificant trend to reduced lesion area in the proximal aorta.

Conclusions— Our data indicate that ITX5061 increases HDL-C levels by inhibition of SR-BI activity. This suggests that pharmacological inhibition of SR-BI has the potential to raise HDL-C and apoA-I levels without adverse effects on VLDL/LDL cholesterol levels in humans.

Methods and Results— ApoE^–/– mice were fed with hyperlipidemic diet for 4 to 10 weeks, then randomized and treated with saline (controls), TWEAK (10 µg/kg/d), anti-TWEAK neutralizing mAb (1000 µg/kg/d), TWEAK plus anti-TWEAK antibody (10 µg TWEAK +1000 µg anti-TWEAK/kg/d), or nonspecific IgG (1000 µg/kg/d) daily for 9 days. In ApoE^–/– mice, exogenous TWEAK administration in ApoE^–/– mice induced activation of NF-B, a key transcription factor implicated in the regulation of the inflammatory response, in vascular and renal lesions. Furthermore, TWEAK treatment increased chemokine expression (RANTES and MCP-1), as well as macrophage infiltration in atherosclerotic plaques and renal lesions. These effects were associated with exacerbation of vascular and renal damage. Conversely, treatment of ApoE^–/– mice with an anti-TWEAK blocking mAb decreased NF-B activation, proinflammatory cytokine expression, macrophage infiltration, and vascular and renal injury severity, indicating a pathological role for endogenous TWEAK. Finally, in murine vascular smooth muscle cells or tubular cells, either ox-LDL or TWEAK treatment increased expression and secretion of both RANTES and MCP-1. Furthermore, ox-LDL and TWEAK synergized for induction of MCP-1 and RANTES expression and secretion.

Conclusion— Our results suggest that TWEAK exacerbates the inflammatory response associated with a high lipid–rich diet. TWEAK may be a novel therapeutic target to prevent vascular and renal damage associated with hyperlipidemia.

Methods and Results— Mice were treated with once daily intraperitoneal injections of leptin (125 µg/mouse/d) for 2 months. The mice were then euthanized, and sections of the aortic root and thoracic aorta analyzed histomorphometrically. Measurements of lesion size and surface area occupied by atherosclerotic lesions did not reveal any differences between nontreated and leptin-treated animals. However, von Kossa staining of the aortic root demonstrated an 8.3±2.0-fold increase in lesion calcification as well as a 2.5±0.6-fold increase in valvular calcification in those animals treated with leptin. In addition, the percent total lesion area demonstrating ALP-positive staining was 5.4±2.1-fold greater in leptin-treated mice when compared to nontreated control mice. This increase in ALP staining was also accompanied by an increase in the expression of the osteoblast-specific markers, osteocalcin, and osteopontin.

Conclusions— Based on these observations, we conclude that leptin may increase cardiovascular risk by promoting osteogenic differentiation and thus vascular calcification.

Methods and Results— Chinese miniswine (n=28) were randomized to 1 of 4 groups (n=7 per group): control, SIMV (0.25 mg/kg · d), MSC transplantation, and SIMV+MSCs. AMI was created by ligating the left anterior descending coronary artery; MSCs were injected immediately into the cyanotic myocardium. At 6 weeks, MRI showed the number of dyskinetic segments and the infarct size were significantly decreased in the SIMV group. Cardiac function improved and the perfusion defect decreased significantly in the SIMV+MSC group but not in the MSC-only group (P<0.05, versus control group). MSC survival and differentiation were significantly better in the combination group than in the MSC-only group (P<0.01). Cell apoptosis decreased significantly in both the SIMV and the SIMV+MSC groups but not in the MSC-only group when compared with controls (P<0.05). Furthermore, oxidative stress and inflammatory response was significantly reduced in the infarcted regions in both the SIMV and the SIMV+MSCs groups.

Conclusions— SIMV treatment improves the therapeutic efficacy of MSC transplantation in acutely infarcted hearts by promoting cell survival and cardiovascular differentiation.

Methods and Results— Key parameters of cardiovascular function were compared among adult mice haploinsufficient for elastin (Eln^+/–), fibrillin-1 (Fbn1^+/–), or both proteins (dHet). Physiological and morphological comparisons correlate elastin haploinsufficiency with increased blood pressure and vessel length and tortuosity in dHet mice, and fibrillin-1 haploinsufficiency with increased aortic diameter in the same mutant animals. Mechanical tests confirm that elastin and fibrillin-1 impart elastic recoil and tensile strength to the aortic wall, respectively. Additional ex vivo analyses demonstrate additive and overlapping contributions of elastin and fibrillin-1 to the material properties of vascular tissues. Lastly, light and electron microscopy evidence implicates fibrillin-1 in the hypertension-promoted remodeling of the elastin-deficient aorta.

Conclusions— These results demonstrate that elastin and fibrillin-1 have both differential and complementary roles in arterial wall formation and function, and advance our knowledge of the structural determinants of vascular physiology and disease.

Methods and Results— We showed a predominant arteriogenesis process in the thigh and a predominant angiogenesis-related process in the tibiofibular region, in response to ischemia during the first 15 days. After 15 days, mCT quantitative analysis reveals a remodeling of arterial neovessels and a regression depending on the restoration of the blood flow. We provided also new mCT data on the rapid and potent angiogenic effects of mesenchymal stem cell therapy on vessel formation and organization. We discussed the contribution of this technique compared with or in addition to data generated by the more conventional approaches.

Conclusion— This study demonstrated that optimized mCT is a robust method for providing new insights into the 3D understanding of postischemic vessel formation.

Methods and Results— qRT-PCR and Western blot confirmed highly increased FSS-dependent expression of Abra in growing collaterals. NO blockage by L-NAME abolished FSS-generated Abra expression as well as the whole arteriogenic process. Cell culture studies demonstrated an Abra-triggered proliferation of smooth muscle cells through a mechanism that requires Rho signaling. Local intracollateral adenoviral overexpression of Abra improved collateral conductance by 60% in rabbits compared to the natural response after FAL. In contrast, targeted deletion of Abra in CL57BL/6 mice led to impaired arteriogenesis.

Conclusions— FSS-induced Abra expression during arteriogenesis is triggered by NO and leads to stimulation of collateral growth by smooth muscle cell proliferation.

Methods and Results— To determine whether AngIV would inhibit fibrinolysis via PAI-1 activation and promote thrombosis, we evaluated the degree of fibrinolysis in thrombosis models and investigated the roles of AT4R after vascular injury using IRAP knockout mice (IRAP^–/–). In endothelial cells from control mice (WT; C57Bl6/J), both AngII and AngIV treatments increased PAI-1 mRNA expression in a dose-dependent manner, whereas the response was blunted in endothelial cells from IRAP^–/– mice. FeCl₃-induced thrombosis was suppressed in the carotid arteries of IRAP^–/– mice when compared with WT mice. Similarly, in a model of carotid artery ligation and cuff placement, IRAP^–/– mice demonstrated accelerated fibrinolysis 7 days after surgery and reduced occlusive thrombosis with negative remodeling at 28 days.

Conclusions— AngIV-AT4R signaling has a key role in fibrinolysis and the subsequent formation of arterial thrombosis after vascular injury. AT4R may be a novel therapeutic target against cardiovascular disease.

Methods and Results— Thrombin induced endothelial MMP-10 mRNA and protein levels, through a protease-activated receptor-1 (PAR-1)–dependent mechanism, in a dose- and time-dependent manner. This effect was mimicked by a PAR-1 agonist peptide (TRAP-1) and antagonized by an anti–PAR-1 blocking antibody. MMP-10 induction was dependent on extracellular regulated kinase1/2 (ERK1/2) and c-jun N-terminal kinase (JNK) pathways. By serial deletion analysis, site-directed mutagenesis and electrophoretic mobility shift assay an AP-1 site in the proximal region of MMP-10 promoter was found to be critical for thrombin-induced MMP-10 transcriptional activity. Thrombin and TRAP-1 upregulated MMP-10 in murine endothelial cells in culture and in vivo in mouse aorta. This effect of thrombin was not observed in PAR-1–deficient mice. Interestingly, circulating MMP-10 levels (P<0.01) were augmented in patients with endothelial activation associated with high (disseminated intravascular coagulation) and moderate (previous acute myocardial infarction) systemic thrombin generation.

Conclusion— Thrombin induces MMP-10 through a PAR-1–dependent mechanism mediated by ERK1/2, JNK, and AP-1 activation. Endothelial MMP-10 upregulation could be regarded as a new proinflammatory effect of thrombin whose pathological consequences in thrombin-related disorders and plaque stability deserve further investigation.

Methods and Results— The effects of ADMA on VEGF-induced endothelial cell motility, focal adhesion turnover, and angiogenesis were studied in human umbilical vein endothelial cells (HUVECs) and DDAH I heterozygous knockout mice. ADMA inhibited VEGF-induced chemotaxis in vitro and angiogenesis in vitro and in vivo in an NO-dependent way. ADMA effects were prevented by overexpression of DDAH but were not associated with decreased proliferation, increased apoptosis, or changes in VEGFR-2 activity or expression. ADMA inhibited endothelial cell polarization, protrusion formation, and decreased focal adhesion dynamics, resulting from Rac1 inhibition after decrease in phosphorylation of vasodilator stimulated phosphoprotein (VASP). Constitutively active Rac1, and to a lesser extent dominant negative RhoA, abrogated ADMA effects in vitro and in vivo.

Conclusion— The ADMA/DDAH pathway regulates VEGF-induced angiogenesis in an NO- and Rac1-dependent manner.

Methods and Results— When murine ES cell-derived VEGFR2⁺ cells were exposed to shear stress, expression of the arterial EC marker protein ephrinB2 increased dose-dependently. The ephrinB2 mRNA levels also increased in response to shear stress, whereas the mRNA levels of the venous EC marker EphB4 decreased. Notch cleavage and translocation of the Notch intracellular domain (NICD) into the nucleus occurred as early as 30 minutes after the start of shear stress and increased with time. Gamma-Secretase inhibitors (DAPT and L685 458) and the recombinant extracellular domain of the Notch ligand DLL4 abolished the shear stress-induced NICD translocation, and that, in turn, blocked the shear stress-induced upregulation of ephrinB2 expression. In addition, the VEGF receptor kinase inhibitor SU1498 was found to suppress both the shear-stress-induced Notch cleavage and up-regulation of ephrinB2 expression.

Conclusion— Exposure to shear stress induces an increase in expression of ephrinB2 in murine ES cells via VEGF-Notch signaling pathways.

Methods and Results— Northern blot analysis and ELISA revealed that LPS-induced TNF- upregulation was strongly suppressed by PHD inhibitors, dimethyloxallyl glycine (DMOG), and TM6008 in RAW264.7 macrophages. DMOG suppressed LPS-induced TNF- upregulation in HIF-1–depleted cells and HIF-1 overexpression failed to suppress the induction of TNF-. DMOG rather suppressed LPS-induced NF-B transcriptional activity. Downregulation of Phd1 or Phd2 mRNA by RNA interference partially attenuated LPS-induced TNF- induction. DMOG also inhibited LPS-induced TNF- production in peritoneal macrophages as well as human macrophages.

Conclusions— PHD inhibition by DMOG or RNA interference inhibited LPS-induced TNF- upregulation in macrophages possibly through NF-B inhibition, which is independent of HIF-1 accumulation. This study suggests that PHDs are positive regulators of LPS-induced inflammatory process, and therefore inhibition of PHD may be a novel strategy for the treatment of inflammatory diseases.

Methods and Results— In THP-1 monocytes treated with TNF- (1 to 100 pmol/L/30 minutes), cytosolic RhoA small GTPase rapidly translocated to the plasma membrane via functionally active ezrin/radixin/moesin (ERM) complex, a cytoskeletal linker, and subsequent actin polymerization through NF-B activation. The threonine phosphorylation of ERM was accomplished by the activation of TNF receptor type I (TNFRI) and signaling pathways involving PI3K and an atypical PKC; ie, PKC. The TNF--treated monocytes (10 pmol/L) displayed more potent and prolonged generation of GTP-bound RhoA in response to secondary stimulation with RhoA-activating monocyte chemoattractant protein-1 (MCP-1). Clearly, human circulating monocytes preconditioned by 10 pmol/L TNF- augmented MCP-1–mediated chemotaxis and firm adhesion on VCAM-1 and ICAM-1 in vitro and ex vivo. The elevation of serum TNF- (>5 pmol/L within 16 hours), which was introduced by intraperitoneal injection of mouse-specific TNF- to C57/BL6 mice, enhanced the number of CD80+ monocytes transmigrating to the JE/MCP-1–injected intraperitoneal space.

Conclusions— Picomolar concentrations of TNF- in the bloodstream may prime the RhoA-dependent activities of circulating monocytes to enhance recruitment to active inflammatory foci.

Methods and Results— Cells were treated with eotaxin, and the monolayer permeability was studied by using a costar transwell system with a Texas Red–labeled dextran tracer. Eotaxin significantly increased monolayer permeability in a concentration-dependent manner. In addition, eotaxin treatment significantly decreased the mRNA and protein levels of endothelial junction molecules including zonula occludens-1 (ZO-1), occludin, and claudin-1 in a concentration-dependent manner as determined by real-time RT-PCR and Western blot analysis, respectively. Increased oxidative stress was observed in eotaxin-treated HCAECs by analysis of cellular glutathione levels. Furthermore, eotaxin treatment substantially activated the phosphorylation of MAPK p38. HCAECs expressed CCR3. Consequently, antioxidants (ginkgolide B and MnTBAP), specific p38 inhibitor SB203580, and anti-CCR3 antibody effectively blocked the eotaxin-induced permeability increase in HCAECs. Eotaxin also increased the phosphorylation of Stat3 and nuclear translocation of NF-B in HCAECs.

Conclusions— Eotaxin increases vascular permeability through CCR3, the downregulation of tight junction proteins, increase of oxidative stress, and activation of MAPK p38, Stat3, and NF-kB pathways in HCAECs.

Methods and Results— By screening phosphorylation-deficient and mimetic mutations in SRF^–/– embryonic stem cells, we identified T159 as a phosphorylation site that significantly inhibits SMC-specific gene expression in an embryonic stem cell model of SMC differentiation. This residue conforms to a highly conserved consensus cAMP-dependent protein kinase (PKA) site, and in vitro and in vivo labeling studies demonstrated that it was phosphorylated by PKA. Results from gel shift and chromatin immunoprecipitation assays demonstrated that T159 phosphorylation inhibited SRF binding to SMC-specific CArG elements. Interestingly, the myocardin factors could at least partially rescue the effects of the T159D mutation under some conditions, but this response was promoter specific. Finally, PKA signaling had much less of an effect on c-fos promoter activity and SRF binding to the c-fos CArG.

Conclusions— Our results indicate that phosphorylation of SRF by PKA inhibits SMC-specific transcription suggesting a novel signaling mechanism for the control of SMC phenotype.

Methods and Results— Mass spectrometry studies showed overexpressed rat GCH-1 was phosphorylated at serine (S) 51, S167, and threonine (T) 231 in HEK293 cells, whereas a computational analysis of GCH-1 revealed 8 potential phosphorylation sites (S51, S72, T85, T91, T103, S130, S167 and T231). GCH-1 activity and BH4 were significantly decreased in cells transfected with the phospho-defective mutants (S72A, T85A, T91A, T103A, or S130A) and increased in cells transfected with the T231A mutant. BH4 and BH2 were increased in cells transfected with S51E, S72E, T85E, T91E, T103D, or T130D mutants, but decreased in cells transfected with the T231D mutant, whereas cells transfected with the S167A or the S167E mutant had increased BH2. Additionally, cells transfected with the T231A mutant had reduced GCH-1 nuclear localization and nuclear GCH-1 activity.

Conclusion— Our data suggest GCH-1 activity is regulated either positively by phosphorylation S51, S72, T85, T91, T103, and S130, or negatively at T231. Such information might be useful in designing new therapies aiming at improving BH4 bioavailability.

Methods and Results— Formation of redox-active phosphatidylcholine hydroperoxides (PCOOH) and redox-inactive phosphatidylcholine hydroxides (PCOH) was initiated in LDL by free radical-induced oxidation. Human HDL3 inactivated LDL-derived PCOOH (–62%, P<0.01) and enhanced accumulation of PCOH (2.1-fold, P<0.05); in parallel, HDL3 accumulated minor amounts of PCOOH. Enzyme-deficient reconstituted dense HDL potently inactivated PCOOH (–43%, P<0.01). HDL3-mediated reduction of PCOOH to PCOH occurred concomitantly with oxidation of methionine residues in HDL3-apolipoprotein AI (apoAI). Preoxidation of methionine residues by chloramine T markedly attenuated PCOOH inactivation (–35%); by contrast, inhibition of HDL3-associated enzymes was without effect. PCOOH transfer rates from oxidized LDL to phospholipid liposomes progressively decreased with increment in the rigidity of the phospholipid monolayer.

Conclusions— The redox status of apoAI and surface lipid rigidity represent major determinants of the potent HDL3-mediated protection of LDL against free radical-induced oxidation. Initial transfer of PCOOH to HDL3 is modulated by the surface rigidity of HDL3 particles with subsequent reduction of PCOOH to PCOH by methionine residues of apoAI.

Methods and Results— The prospective observational Cancer and Thrombosis Study (CATS) includes patients with newly diagnosed cancer or disease progression, study end point is symptomatic VTE. FVIII was measured on a Sysmex CA 7000 analyzer. Data on 840 patients (median age: 62 years, 25th to 75th percentile 53 to 68, 378 women) were available for analyses, of these 111 patients had hematologic malignancies and 729 solid cancer. During a median observation time of 495 days 62 events occurred. Cumulative probability of VTE after 6 months was 14% in patients with elevated FVIII-levels and 4% in those with normal levels (P=0.001). The association was strongest in younger patients: whereas in 40-year-old patients a 2-fold VTE risk per factor VIII increase of 20% was observed (HR=2.0 [95% CI: 1.5 to 2.7], P<0.0001), this association was still present but attenuated in older patients.

Conclusions— FVIII is independently associated with an increased risk of VTE in cancer patients. The association between FVIII and VTE risk declines with increasing age.

Methods and Results— Cardiac death and nonfatal MI events were identified in the ARIC cohort during follow-up from 1987 through 2001. Markers of inflammation and hemostasis were determined at baseline using standardized procedures. Cox proportional hazard regression and polytomous logistic regression were used to estimate associations. We observed a positive gradient in incidence of sudden cardiac death (SCD), nonsudden cardiac death (NSCD), and nonfatal MI in association with decreasing levels of albumin and increasing levels of white blood cell count and of markers of hemostasis (fibrinogen, von Willebrand factor, factor VIIIc). Associations for von Willebrand factor were stronger for fatal relative to nonfatal events (3rd versus 1st tertile hazard ratios: SCD 3.11 [95% CI 2.10, 4.59], NSCD 2.12 [95% CI 1.28, 3.49], nonfatal MI 1.42 [95% CI 1.19, 1.70]). For factor VIIIc those associations were strongest for sudden cardiac death: SCD 3.16 (95% CI 2.18, 4.58), NSCD 1.44 (95% CI 0.93, 2.24), nonfatal MI 1.54 (95% CI 1.29, 1.84). Gradients of association for fibrinogen and white blood cell count, examined over tertiles of distribution and per one SD increase, were similar for the 3 end points. All associations were independent of smoking status.

Conclusion— von Willebrand factor and factor VIIIc are associated with an increased risk of cardiac death as compared to the risk of nonfatal MI.

Methods and Results— A white 49-year-old diabetic man had profound FBHL (LDLC: 16 mg/dL) whereas his daughter and sister displayed a milder phenotype (LDLC 44 mg/dL and 57 mg/dL, respectively), all otherwise healthy with a normal liver function. A monoallelic PCSK9 double-mutant R104C/V114A cosegregated with FBHL, with no mutation found at other FHBL-causing loci. A dose-effect was also found in FBHL relatives for plasma APOB and PCSK9 (very-low to undetectable in proband, 50% decreased in sister and daughter) and LDL catabolic rate (256% and 88% increased in proband and daughter). Transient transfection in hepatocytes showed severely impaired processing and secretion of the double mutant which acted as a dominant negative over secretion of wild-type PCSK9.

Conclusion— These results show that heterozygous PCSK9 missense mutations may associate with profound hypobetalipoproteinemia and constitute the first direct evidence in human that decrease of plasma LDLC concentrations associated to PCSK9 LOF mutations are attributable to an increased clearance rate of LDL.

Methods and Results— Lethally-irradiated Ldlr^–/– mice were rescued with hematopoietic progenitors lacking tyrosylprotein sulfotransferase (TPST) activity attributable to deletion of the Tpst1 and Tpst2 genes. TPST deficient progenitors efficiently reconstituted hematopoiesis in Ldlr^–/– recipients and transplantation had no effect on plasma lipids on a standard or atherogenic diet. However, we observed a substantial reduction in the size of atherosclerotic lesions and the number of macrophages in lesions from hyperlipidemic Ldlr^–/– recipients transplanted with TPST deficient progenitors compared to wild-type progenitors. We also document for the first time that murine Psgl-1 and Cx3cr1 are tyrosine-sulfated.

Conclusions— These data demonstrate that protein-tyrosine sulfation is an important contributor to monocytes/macrophage recruitment and/or retention in a mouse model of atherosclerosis.

Methods and Results— We used a bone marrow transplant (BMT) approach and apolipoprotein E–deficient (Apoe^–/–) mice to investigate cellular mechanisms of uPA-accelerated atherosclerosis, aortic dilation, and sudden death. We also used BMT to determine whether postnatal loss of uPA expression in macrophages retards atherosclerosis. BMT from uPA-overexpressing mice yielded recipients with macrophage-specific uPA overexpression; whereas BMT from uPA knockout mice yielded recipients with macrophage-specific loss of uPA expression. Recipients of uPA-overexpressing BM acquired all the vascular phenotypes (accelerated atherosclerosis, aortic medial destruction and dilation, severe coronary stenoses) as well as the sudden death phenotype of uPA-overexpressing mice. Moreover, fat-fed 37-week-old recipients of uPA-null BM had significantly less atherosclerosis than recipients of uPA wild-type marrow (40% less aortic surface lesion area; P=0.03).

Conclusions— The level of uPA expression by macrophages—over a broad range—is an important determinant of atherosclerotic lesion growth in Apoe^–/– mice.

Methods and Results— Congenic 14DKK animals, consisting of a castaneus (CASA/Rk) chromosome 14 interval introgressed onto the C57BL/6J background, displayed a moderate decrease in cholesterol absorption rates. The effect of moderately decreased absorption on atherosclerosis formation was determined in 14DKK apolipoprotein E knockouts (14DKK-apoEKO). When compared to chow diet–fed control apoEKO mice, congenic 14DKK-apoEKO displayed a moderate 41% decrease in cholesterol absorption rates, 30% to 37% decrease in plasma cholesterol levels, and a 70% decrease in atherosclerosis formation. Studies on cholesterol efflux and reverse cholesterol transport (RCT) from 14DKK bone marrow–derived macrophages rejected a 14DKK interval-dependent atheroprotective effects that operate in macrophages. In contrast, 14DKK-apoEKO congenics were characterized by a 60% increase in RCT from peripheral tissue macrophages.

Conclusions— These studies strongly suggest that moderately decreased cholesterol absorption rates result in a large atheroprotective effect attributable to a decrease in plasma cholesterol levels and an increase in RCT from peripheral tissue macrophages.

Methods and Results— In vitro estrogens prompted the release of HSP27 from macrophages in an ERβ specific manner that involved exosomal trafficking. Ovariectomy nullified the previously recognized attenuation in aortic lesion area in HSP27^o/eapoE^–/– mice compared to apoE^–/– mice. Supplementation with 17β-estradiol resulted in a >15x increase in uterine weight and attenuation of atherogenesis in all mice, although HSP27^o/eapoE^–/– had 34% less lesion burden compared to apoE^–/– mice. Mice treated with the ERβ-specific agonist, DPN had no effect on uterine weight but a 28% decrease in aortic lesion area in HSP27^o/eapoE^–/– compared to apoE^–/– mice. HSP27 serum levels showed a similar gradual increase with E2 and DPN replacement treatment but did not change in untreated mice.

Conclusions— The extracellular release of and atheroprotection provided by HSP27 is estrogen dependent.

Methods and Results— Human and mouse atherosclerotic plaques expressed high level of B1R mRNA and protein. In addition, B1R expression was upregulated in the aortic arch (low LSS region) of ApoE^–/– mice fed a high-fat diet compared to vascular regions of high LSS and animals fed normal chow. Of interest, a greater expression of B1R was noticed in endothelial cells from regions of low LSS in aortic arch of ApoE^–/– mice. B1R was also upregulated in human umbilical vein endothelial cells (HUVECs) exposed to low LSS (0 to 2 dyn/cm²) compared to physiological LSS (6 to 10 dyn/cm²): an effect similarly evident in murine vascular tissue perfused ex vivo. Functionally, B1R activation increased prostaglandin and CXCL5 expression in cells exposed to low, but not physiological, LSS. IL-1β and ox-LDL induced B1R expression and function in HUVECs, a response substantially enhanced under low LSS conditions and inhibited by blockade of NFB activation.

Conclusion— Herein, we show that LSS is a major determinant of functional B1R expression in endothelium. Furthermore, whereas physiological high LSS is a powerful repressor of this inflammatory receptor, low LSS at sites of atheroma is associated with substantial upregulation, identifying this receptor as a potential therapeutic target.

Methods and Results— ApoE^–/– mice infused for 28 days with AngII using osmotic minipumps were treated with placebo, 10 mg/kg/d simvastatin, or 100 mg/kg/d CI1040. 95% of AngII-treated mice developed AAA with neovascularization of the lesion, increased ERK phosphorylation, MCP-1 secretion, and MMP activity. These effects were markedly reversed by simvastatin and in part by CI1040. Furthermore, simvastatin and the ERK inhibitor U0126 reversed AngII-stimulated angiogenesis and MMP secretion by human umbilical vein endothelial cells.

Conclusions— These data support the conclusion that simvastatin interferes with AAA formation induced by AngII in ApoE^–/– mice at least in part via ERK inhibition.

Methods and Results— Smooth muscle cells isolated from control (smLrp1^+/+) and smooth muscle-specific Lrp1 knockout (smLrp1^–/–) mice were characterized based on morphology, smooth muscle marker protein expression levels, and growth rates in vitro. Vascular functions were assessed by aortic constrictive response to agonist stimulation in situ and neointimal hyperplasia to carotid arterial injury in vivo. The smLrp1^–/– smooth muscle cells displayed reduced -actin and calponin expression and an accelerated growth rate attribtuable to sustained phosphorylation of platelet-derived growth factor receptor (PRGFR) and protein kinase B/Akt. Vasoconstrictive response to agonist stimulation was impaired in aortic rings isolated from smLrp1^–/– mice. Injury-induced neointimal hyperplasia was significantly increased in smLrp1^–/– mice. The increase in neointima was associated with corresponding elevated activation of PDGFR signaling pathway.

Conclusions— Smooth muscle expression of Lrp1 is important in maintaining normal vascular functions under normolipidemic conditions. The absence of Lrp1 expression results in greater smooth muscle cell proliferation, deficient contractile protein expression, impairment of vascular contractility, and promotion of denudation-induced neointimal hyperplasia.

Methods and Results— Reduced glutathione (GSH) and glutathione disulfide (GSSG) levels in peritoneal macrophages isolated from mildly, moderately, and severe metabolically-stressed LDL-R^–/– mice were measured by HPLC, and the glutathione reduction potential (E_h) was calculated. Macrophage E_h correlated with the macrophage content in both atherosclerotic (r²=0.346, P=0.004) and renal lesions (r²=0.480, P=0.001) in these mice as well as the extent of both atherosclerosis (r²=0.414, P=0.001) and kidney injury (r²=0.480, P=0.001). Compared to LDL-R^–/– mice exposed to mild metabolic stress, macrophage recruitment into MCP-1-loaded Matrigel plugs injected into LDL-R^–/– mice increased 2.6-fold in moderately metabolically-stressed mice and 9.8-fold in severely metabolically-stressed mice. The macrophage E_h was a strong predictor of macrophage chemotaxis (r²=0.554, P<0.001).

Conclusion— Thiol oxidative stress enhances macrophage recruitment into vascular and renal lesions by increasing the responsiveness of macrophages to chemoattractants. This novel mechanism contributes at least in part to accelerated atherosclerosis and kidney injury associated with dyslipidemia and diabetes in mice.

Methods and Results— Stimulation of the mouse cremaster muscle with Ccl2/JE/MCP-1 or Ccl3/MIP-1 induced a significant increase in numbers of firmly adherent and transmigrated leukocytes (>70% neutrophils) as observed by in vivo microscopy. This increase was significantly attenuated in mice receiving an inhibitor of RNA transcription (actinomycin D) or antagonists of platelet activating factor (PAF; BN 52021) and leukotrienes (MK-886; AA-861). In contrast, leukocyte responses elicited by PAF and leukotriene-B₄ (LTB₄) themselves were not affected by actinomycin D, BN 52021, MK-886, or AA-861. Conversely, PAF and LTB₄, but not Ccl2/JE/MCP-1 and Ccl3/MIP-1, directly activated neutrophils as indicated by shedding of CD62L and marked upregulation of CD11b. Moreover, Ccl2/JE/MCP-1- and Ccl3/MIP-1-elicited leakage of fluorescein isothiocyanate dextran as well as collagen IV remodeling within the venular basement membrane were completely absent in neutrophil-depleted mice.

Conclusions— Ccl2/JE/MCP-1 and Ccl3/MIP-1 mediate firm adherence and (subsequent) transmigration of neutrophils via protein synthesis and secondary generation of leukotrienes and PAF, which in turn directly activate neutrophils. Thereby, neutrophils facilitate basement membrane remodeling and promote microvascular leakage.

Methods and Results— Dorsal skinfold window chambers were implanted into C57Bl/6 wild-type (WT) mice, as well as the following bone marrow chimeras (donor-host): WT-WT, CCR2^–/–-WT, WT-CCR2^–/–, and EGFP⁺-WT. One day after implantation, tissue MCP-1 levels rose from "undetectable" to 463pg/mg, and the number of EGFP⁺ cells increased more than 4-fold, indicating marked inflammation. A 66% (28 µm) increase in maximum arteriolar diameter was observed over 7 days in WT-WT mice. This arteriolar remodeling response was completely abolished in CCR2^–/–-WT mice but largely rescued in WT-CCR2^–/– mice. EGFP⁺ BMCs were numerous throughout the tissue, but we found no evidence that EGFP⁺ BMCs transdifferentiate into smooth muscle, based on examination of >800 arterioles and venules.

Conclusions— BMC-specific CCR2 expression is required for injury/inflammation-associated arteriolar remodeling, but this response is not characterized by the differentiation of BMCs into smooth muscle.

Methods and Results— Human CXCR4⁺ and CXCR4^– BMCs were sorted by magnetic beads. CXCR4⁺ BMCs showed a significantly higher invasion capacity under basal conditions and after SDF-1 stimulation. Hematopoietic or mesenchymal colony-forming capacity did not differ between CXCR4⁺ and CXCR4^– BMCs. Injection of CXCR4⁺ BMCs in mice after induction of hindlimb ischemia significantly improved the recovery of perfusion compared to injection of CXCR4^– BMCs. Likewise, capillary density was significantly increased in CXCR4⁺ BMC-treated mice. Because part of the beneficial effects of cell therapy were attributed to the release of paracrine effectors, we analyzed BMC supernatants for secreted factors. Importantly, supernatants of CXCR4⁺ BMCs were enriched in the proangiogenic cytokines HGF and PDGF-BB.

Conclusion— CXCR4⁺ BMCs exhibit an increased therapeutic potential for blood flow recovery after acute ischemia. Mechanistically, their higher migratory capacity and their increased release of paracrine factors may contribute to enhanced tissue repair.

Methods and Results— Pigs (n=6 per group) were studied after 10 weeks of normal, renovascular HTN, or renovascular HTN+ bindarit (MCPs inhibitor, 50 mg/kg/d PO). Left ventricular (LV) function, myocardial microvascular permeability, and fractional vascular volume were assessed by fast computed tomography before and after adenosine infusion (400 µg/kg/min). Myocardial fibrosis, inflammation, and microvascular remodeling were determined ex vivo. Hypertension was not altered by bindarit, but LV hypertrophy and diastolic function were improved. In response to adenosine, myocardial microvascular permeability increased in HTN (from 0.0083±0.0009 to 0.0103±0.0011 AU, P=0.038 versus baseline) and fractional vascular volume decreased, whereas both remained unchanged in normal and HTN+bindarit pigs. HTN upregulated endothelin-1 expression, myocardial inflammation, and microvascular wall thickening, which were inhibited by bindarit.

Conclusions— MCPs partly mediate myocardial inflammation, fibrosis, vascular remodeling, and impaired vascular integrity induced by hypertension. Inhibition of MCPs could potentially be a therapeutic target in hypertensive cardiomyopathy.

Methods and Results— In a rat model of repetitive episodic myocardial ischemia (RI, 40 seconds LAD occlusion every 20 minutes for 2 hours and 20 minutes, 3 times/d for 5 days) CCG was deduced from collateral-dependent flow (flow to LAD region during occlusion). After RI, G-CSF (100 µg/kg/d) increased CCG (P<0.01) (0.47±0.15) versus vehicle (0.14±0.06). Surprisingly, G-CSF treatment without RI increased CCG (0.57±0.18) equal to G-CSF+RI. We evaluated ROS by dihydroethidine (DHE) fluorescence (LV injection, 60 µg/kg, during two episodes of ischemia). DHE fluorescence was double in G-CSF+RI versus vehicle+RI (P<0.01), and even higher in G-CSF without RI (P<0.01). Interestingly, the DHE signal did not colocalize with myeloperoxidase (immunostaining, neutrophil marker) but appeared in cardiac myocytes. The study of isolated cardiac myocytes revealed the cytokine stimulates ROS which elicit production of angiogenic factors. Apocynin inhibited G-CSF effects both in vivo and in vitro.

Conclusions— G-CSF stimulates ROS production directly in cardiomyocytes, which plays a pivotal role in triggering adaptations of the heart to ischemia including growth of the coronary collaterals.

Methods and Results— We selected 2 TUFs of more than 27 to study their role for blood vessel development in zebrafish. Morpholino (MO) knockdown of the zebrafish orthologs of the first TUF (TUF1, mouse cDNA BC022623) showed disruption of the intersegmental vessels (ISV) at 2 days postfertilization as observed by live imaging of fli:EGFP-transgenic embryos. The morphants showed abnormal blood circulation, but no effect on hematopoiesis was observed as demonstrated by gata-1 in situ hybridizations. Because knockdown of TUF1 resulted in disruption of the ISV patterning we named the TUF1 somitovasculin. TUF2 has been identified as cDNA clone BC020535. The MO knockdown of TUF2 resulted in a phenotype with an enlarged heart and the embryos lacked circulation completely.

Conclusion— We have shown the participation of a novel transcript (named somitovasculin) in circulatory vessel development. The combination of expression profiling in differentiating mES cells and the zebrafish model has the potential for rapid identification and functional characterization of TUFs.

Methods and Results— PBS, 1x10⁶ human fibroblasts (Fbr), 1x10⁵ USSCs (LD), or 1x10⁶ USSCs (HD) were transplanted intramyocardially 20 minutes after ligating the LAD of nude rats. Echocardiography and a microtip conductance catheter at day 28 revealed a dose-dependent improvement of LV function after USSC transplantation. Necropsy examination revealed dose-dependent augmentation of capillary density and inhibition of LV fibrosis. Dual-label immunohistochemistry for cardiac troponin-I and human nuclear antigen (HNA) demonstrated that human cardiomyocytes (CMCs) were dose-dependently generated in ischemic myocardium 28 days after USSC transplantation. Similarly, dual-label immunostaining for smooth muscle actin and class I human leukocyte antigen or that for von Willebrand factor and HNA also revealed a dose-dependent vasculogenesis after USSC transplantation. RT-PCR indicated that expression of human-specific genes of CMCs, smooth muscle cells, and endothelial cell markers in infarcted myocardium were significantly augmented in USSC-treated animals compared with control groups.

Conclusions— USSC transplantation leads to functional improvement and recovery from MI and exhibits a significant and dose-dependent potential for concurrent cardiomyogenesis and vasculogenesis.

Methods and Results— The basic-region leucine zipper protein, c-Jun is poorly expressed in the normal myocardium and is induced within 24 hours after myocardial ischemia-reperfusion injury. Synthetic catalytic DNA molecules (DNAzymes) targeting c-Jun (Dz13) reduce infarct size in the area-at-risk (AAR) regardless of whether it is delivered intramyocardially at the initiation of ischemia or at the time of reperfusion. Dz13 attenuates neutrophil infiltration, c-Jun and ICAM-1 expression in vascular endothelium, cardiomyocyte apoptosis, and the generation of reactive oxygen species in the reperfused myocardium. It inhibits infiltration into the AAR of complement 3 (C3), C3a receptor (C3aR), membrane attack complex-1 (Mac-1), or matrix metalloproteinase-2 (MMP-2) positive inflammatory cells. Dz13 also improves cardiac function without influencing myocardial vascularity or fibrosis.

Conclusion— These findings demonstrate the regulatory role of c-Jun in the pathogenesis of myocardial inflammation and infarction following ischemia-reperfusion injury, and inhibition of this process using catalytic DNA.

Methods and Results— Cardiac hypertrophy and dysfunction were established in mice by transverse aortic constriction (TAC). Nrf2 expression was transiently increased and then declined to the basal level while impairment of cardiac function proceeded. The knockout of Nrf2 (Nrf2^–/–) did not cause any apparent structural and functional abnormalities in the unstressed heart. However, Nrf2^–/– mice after TAC developed pathological cardiac hypertrophy, significant myocardial fibrosis and apoptosis, overt heart failure, and increased mortality, which were associated with elevated myocardial levels of 4-hydroxy-2-nonenal and 8-hydroxydeoxyguanosine and a complete blockade of the myocardial expression of several antioxidant genes. Overexpression of Nrf2 dramatically inhibited hypertrophic factor–induced ROS production and growth in both cardiomyocytes and cardiac fibroblasts, whereas knockdown of Nrf2 exerted opposite effects in both cells.

Conclusions— These findings demonstrate that activation of Nrf2 provides a novel mechanism to protect the murine heart against pathological cardiac hypertrophy and heart failure via suppressing oxidative stress.

Methods and Results— En face staining revealed that Nrf2 was activated in ECs at an atheroprotected region of the murine aorta where it negatively regulated p38–VCAM-1 signaling, but was expressed in an inactive form in ECs at an atherosusceptible site. Treatment with sulforaphane, a dietary antioxidant, activated Nrf2 and suppressed p38–VCAM-1 signaling at the susceptible site in wild-type but not Nrf2^–/– animals, indicating that it suppresses EC activation via Nrf2. Studies of cultured ECs revealed that Nrf2 inactivates p38 by suppressing an upstream activator MKK3/6 and by enhancing the activity of the negative regulator MKP-1.

Conclusions— Nrf2 prevents ECs at the atheroprotected site from exhibiting a proinflammatory state via the suppression of p38–VCAM-1 signaling. Pharmacological activation of Nrf2 reduces EC activation at atherosusceptible sites and may provide a novel therapeutic strategy to prevent or reduce atherosclerosis.

Methods and Results— Aliskiren (10 mg/kg/d) or PBS was administered to C57BL/6 mice (6–7 weeks of age; Oriental Yeast, Tokyo, Japan) for 2 weeks via an osmotic pump. Blood pressure was not significantly changed in the 2 groups throughout the experimental period. A perivascular cuff injury was then introduced to the femoral artery and real-time intravital microscopic observation was conducted 24 hours after injury. The number of adherent leukocytes was elevated in the injured mice without aliskiren (43.8±9.3/10^–2 mm²), whereas that was significantly reduced in the mice with aliskiren (18.4±4.4, P<0.05). Treatment of human umbilical vein endothelial cells (HUVECs) with aliskiren significantly reduced the adhesion of THP-1 cells to TNF-–activated HUVECs (P<0.05). Interestingly, TNF-–induced renin activity and angiotensin II production in HUVECs were also blunted by aliskiren. Furthermore, exogenous renin and angiotensin II abrogated the aliskiren-mediated reduction of THP-1 cell adhesion to HUVECs.

Conclusions— Our in vivo and in vitro findings indicate a pivotal role for renin inhibition in vascular inflammation independent of blood pressure.

Methods and Results— In collagen matrices seeded with a mixture of mast cells and fibroblasts, fibroblasts lacking the 11 integrin subunit (11^–/–) contracted collagen gels less efficiently than control fibroblasts, suggesting that the 11β1 integrin is able to mediate tensile force in connective tissues. In 11^–/– mice, control Pif in skin did not differ from the pressure found in wild-type mice. Whereas a reduction in Pif was found in control mice after inducing inflammation, thereby contributing to fluid extravasation and edema formation, such a reduction was not seen in 11^–/– mice. That this effect is mediated through the extracellular compartment is suggested by a similar plasma protein extravasation ratio in 11^–/– and wild-type mice.

Conclusions— Our data suggest that 11β1 integrins on dermal fibroblasts mediate collagen lattice remodeling and have a mechanistic role in controlling Pif in inflammation and thereby fluid extravasation and edema formation in vivo.

Methods and Results— We have used mice lacking PPARβ/ (PPARβ/^–/–) to show the effects of the PPARβ/ agonist GW501516 on platelet adhesion and cAMP levels are mediated specifically by PPARβ/, however GW501516 had no PPARβ/-specific effect on platelet aggregation. Studies in human platelets showed that PKC, which can mediate platelet activation, was bound and repressed by PPARβ/ after platelets were treated with GW501516.

Conclusions— These data provide evidence of a novel mechanism by which PPAR receptors influence platelet activity and thereby thrombotic risk.

Methods and Results— We discovered that human and mouse megakaryocytes express Foxp3 mRNA and protein. Using shRNA and Foxp3^sf mice, we demonstrated that Foxp3-deficient mouse and human megakaryocyte progenitors exhibited proliferation defects. Striking platelet abnormalities were observed in both an IPEX patient and Foxp3^sf mice. Impaired platelet spreading and release of TGF-β and CD40 ligand (CD40L), and abnormal levels of plasma CD40L were observed in a case of IPEX syndrome. Foxp3^sf mice were thrombocytopenic and had increased platelet volume and altered serum levels of CD40L, TXB₂, and TGF-β.

Conclusion— These findings provide compelling new evidence that Foxp3 is needed for proper megakaryopoiesis and plays a role in regulating platelet function including spreading and release.

Methods and Results— Platelets were stimulated with A23187, thapsigargin (TG) and thrombin plus convulxin (Thr/Cvx), and Jurkat cells with ionomycin, in the presence or absence of cyclosporin A (CsA), a mitochondrial permeability transition pore inhibitor. m loss occurred when platelets were stimulated in Ca²⁺ medium in conditions exposing PS, but also in EGTA medium. CsA inhibited PS exposure, [Ca²⁺]_cyt increase, and m loss in platelets stimulated with TG and Thr/Cvx, but had no inhibitory effect on A23187 stimulation. CsA reduced TG-induced Ca²⁺ release from the endoplasmic reticulum and, consequently, external Ca²⁺ influx. In ionomycin-stimulated Jurkat cells, rapid PS exposure was evidenced but not m loss, and CsA did not inhibit the process. The status of phosphorylated Bad and Bcl-2 in both cell types remained unchanged on stimulation.

Conclusions— Whether m loss occurs or not, PS exposure is triggered by a high [Ca²⁺]_cyt increase. Data further demonstrate that CsA prevents membrane scrambling by inhibiting the high [Ca²⁺]_cyt increase, independently of its effect on mitochondrial permeability transition pore.

Methods and Results— Genotyped primary human umbilical vein endothelial cells (ECs) were exposed to fluid shear stress (FSS) and analyzed for nitric oxide (NO) and superoxide anion (O₂^–) formation as well as mRNA and protein expression of different antioxidant enzymes. Dysfunctional CC-genotype ECs failed to upregulate NO synthase expression in response to FSS and exhibited a reduced NO synthesis capacity when compared to functionally intact TT-genotype ECs. However, only CC-genotype ECs responded to FSS with an Egr-1–mediated increase in manganese-containing superoxide dismutase (SOD-2) expression, shielding them from endothelin-1–induced oxidative stress in a NO-independent manner.

Conclusions— This FSS-induced rise in SOD-2 expression in CC-genotype ECs effectively stabilizes their antiatherosclerotic phenotype and may explain not only the comparatively slow onset of CAD in homozygous carriers of the C-allele of the nos-3 gene but also define a general strategy for preventing endothelial dysfunction at the outset of atherosclerosis.

Methods and Results— In human cultured endothelial cells, nitric oxide synthase expression was exclusively shear stress–dependent whereas expression of glutathione peroxidase-1 (GPx-1), but not that of Cu²⁺/Zn²⁺-superoxide dismutase or Mn²⁺-superoxide dismutase, was upregulated solely in response to cyclic stretch. GPx-1 expression was also enhanced in isolated mouse arteries perfused at high pressure. Combined pharmacological and decoy oligodeoxynucleotide blockade revealed that activation of p38 MAP kinase followed by nuclear translocation of CCAAT/enhancer binding protein plays a pivotal role in stretch-induced GPx-1 expression in human endothelial cells. Antisense oligodeoxynucleotide knockdown of GPx-1 reinforced both their capacity to generate hydrogen peroxide and the transient stretch-induced expression of CD40, monocyte chemoatractant protein-1, and vascular cell adhesion molecule-1. Consequently, THP-1 monocyte adhesion to the GPx-1–depleted cells was augmented.

Conclusions— Stretch-induced proatherosclerotic gene expression in human endothelial cells seems to be hydrogen peroxide-mediated. The concomitant rise in GPx-1 expression, but not that of other antioxidant enzymes, may comprise an adaptive mechanism through which the cells maintain their antiatherosclerotic properties in spite of a decreased bioavailability of nitric oxide.

Methods and Results— AMPK inhibition by Compound C or siRNA had a significant blocking effect on the PS-induced KLF2 expression. The induction of KLF2 by PS led to the increase in eNOS and the suppression of ET-1, which could be reversed by KLF2 siRNA. In addition, PS induced the phosphorylation of ERK5 and MEF2 which are necessary for the KLF2 expression. These mechanotransduction events were abrogated by the blockade of AMPK. Furthermore, the phosphorylation levels of ERK5 and MEF2, as well as the expression of KLF2, were significantly reduced in the aorta of AMPK2 knockout mice when compared with wild-type control mice.

Conclusion— The flow-mediated AMPK activation is a newly defined KLF2 regulatory pathway in vascular endothelium that acts via ERK5/MEF2.

Methods and Results— We found that vascular β-amyloid (Aβ), Aβ40, inhibited the proliferative activity of human brain vascular endothelial cells (HBECs) without toxic effects on them. This peptide also inhibited tube formation and migration of HBECs. Moreover, Aβ40 inhibited ex vivo hippocampal revascularization, reendothelialization, and the differentiation of adult endothelial progenitor cells. Importantly, Aβ40 suppressed the proliferative activity of HBECs through the induction of "self-digesting" autophagy. This induction involved the intracellular regulation of class 3 phosphatidylinositol 3-kinase (PI3K) as well as Akt signaling in HBECs. Furthermore, tissue culture of murine brain sections from GFP-LC3 transgenic mice revealed that Aβ40 not only reduced the vessel density in hippocampal lesions, but also induced autophagy in neurovascular ECs.

Conclusions— Our present findings indicate that the initial progression of AD might be in part driven by Aβ40-induced endothelial autophagy and impairment of neurovascular regeneration, suggesting important implications for therapeutic approaches to AD.

Methods and Results— In isolated hamster gracilis muscle resistance arteries, pressure-dependent activation/translocation of Sk1 by ERK1/2 was critically dependent on its serine 225 phosphorylation site. Specifically, expression of Sk1^S225A reduced resting and myogenic tone, resting Ca²⁺, pressure-induced Ca²⁺ elevations, and Ca²⁺ sensitivity. The lack of function of the Sk1^S225A mutant could not be entirely overcome by forced localization to the plasma membrane via a myristoylation/palmitylation motif; the membrane anchor also significantly inhibited the function of the wild-type Sk1 enzyme. In both cases, Ca²⁺ sensitivity and myogenic tone were attenuated, whereas Ca²⁺ handling was normalized/enhanced. These discrete effects are consistent with cell surface receptor-mediated effects (Ca²⁺ sensitivity) and intracellular effects of S1P (Ca²⁺ handling). Accordingly, S1P₂ receptor inhibition (1µmol/L JTE013) attenuated myogenic tone without effect on Ca²⁺.

Conclusions— Translocation and precise subcellular positioning of Sk1 is essential for full Sk1 function; and two distinct S1P pools, proposed to be intra- and extracellular, contribute to the maintenance of vascular tone.

Methods and Results— Exposure of bone marrow–derived macrophages from human CETP transgenic mice to the T0901317 LXR agonist increased CETP, PLTP, and ABCA1 mRNA levels. T0901317 also markedly increased CETP mRNA levels and CETP production in human differentiated macrophages, whereas it had no effect on CETP expression in human peripheral blood monocytes. In inflammatory mouse and human macrophages, LXR-mediated CETP gene upregulation was inhibited, even though ABCA1, ABCG1, and SREBP1c inductions were maintained. The inhibition of CETP gene response to LXR agonists in inflammatory cells was independent of lipid loading (ie, oxidized LDL increased CETP production in noninflammatory macrophages with a synergistic effect of synthetic LXR agonists).

Conclusion— LXR-mediated induction of human CETP expression is switched on during monocyte-to-macrophage differentiation, is magnified by lipid loading, and is selectively lost in inflammatory macrophages, which suggests that inflammatory cells may not increase the circulating CETP pool on LXR agonist treatment.

Methods and Results— ABCG1 mRNA levels were strongly increased in acLDL-loaded THP-1 macrophages and in HMDM on stimulation with LXR agonists. However, silencing of ABCG1 expression using ABCG1-specific siRNA indicated that ABCG1 was not essential for cholesterol efflux to HDL in cholesterol-loaded human macrophages stimulated with LXR agonists. Indeed, ABCA1 was solely responsible for the stimulation of cholesterol efflux to HDL on LXR activation, as this effect was abolished in HMDM from Tangier patients. Furthermore, depletion of cellular ATP indicated that the LXR-induced export of cholesterol was an ATP-dependent transport mechanism in human macrophages. Finally, use of an anti–Cla-1 blocking antibody identified the Cla-1 receptor as a key component in cholesterol efflux to HDL from cholesterol-loaded human macrophages.

Conclusion— Our data indicate that stimulation of cholesterol efflux to HDL by LXR agonists in human foam cells involves an ATP-dependent transport mechanism mediated by ABCA1 that it appears to be independent of ABCG1 expression.

Methods and Results— Long-chain acyl CoA synthetases (ACSLs) play a critical role in fatty acid homeostasis by channeling fatty acids to diverse metabolic pools. We treated mouse peritoneal macrophages (MPMs) with VLDL or FFAs in the presence of triacsin C, an inhibitor of the 3 ACSL isoforms present in macrophages. Treatment of macrophages with VLDL and triacsin C resulted in reduced TG accumulation but increased intracellular FFA levels, which induced lipotoxicity characterized by apoptosis. Treatment of MPMs with the saturated fatty acid stearic acid in the presence of triacsin C increased intracellular stearic acid and induced apoptosis. Stromal vascular cells collected from high-fat diet–fed mice displayed foam cell morphology and exhibited increased mRNA levels of macrophage markers and ACSL1. Importantly, all of these changes were associated with increased FFA level in AT.

Conclusions— Inhibition of ACSLs during fatty acid loading results in apoptosis via accumulation of FFAs. Our data have implications in understanding the consequences of dysregulated fatty acid metabolism in macrophages.

Methods and Results— We investigated the effects of SFAs on TLR-dependent signaling using a broad range of cell types and readouts. In HEK-293 cells transfected with TLR2, TLR4, or TLR5, SFAs complexed with fatty-acid-free bovine serum albumin (BSA)-stimulated TLR-dependent signaling. However, SFAs alone did not elicit a similar response. Further analysis showed that the effect seen with the complexed SFAs was attributable to LPS and lipopeptide contamination of fatty-acid-free BSA. Additional studies in macrophages, endothelial cells, smooth muscle cells, adipocytes, skeletal muscle cells, and human peripheral blood mononuclear cells confirmed the lack of stimulation of TLR-dependent signaling pathways or expression of TLR-target genes by SFAs.

Conclusions— SFAs do not directly stimulate TLR-dependent signaling, suggesting that alternative mechanisms link dietary fat intake with TLR-associated pathologies. LPS and lipopeptide contamination of the widely used reagent fatty-acid-free BSA explains the previously reported stimulation of TLR2 and TLR4 by SFAs.

Methods and Results— In culture, VICs spontaneously form multicellular aggregates that subsequently develop into calcified nodules, providing an in vitro model for aortic stenosis. Using real-time microscopic tracking, we observed that confluent VIC monolayers spontaneously contract into rounded nodules, suggesting that myofibroblastic contractility is a critical step in the process of nodule formation. Overexpression of SMA increased VIC calcific nodule formation and contractility, whereas knockdown of SMA with siRNAs reduced these phenotypes, suggesting that the expression and contractile properties of SMA are essential to the formation of nodules. Statin treatment of VICs reduced SMA expression, inhibited contractility, and decreased nodule formation. When statins were used to treat preformed nodules, no decrease in the number of calcified nodules was observed, suggesting that statins may play more of a preventative role in aortic stenosis than a cure.

Conclusions— Our studies provide evidence of a causal relationship between VIC myofibroblastic activity and initial VIC calcific nodule formation. Furthermore, we demonstrate that pravastatin inhibition of calcific nodule formation is related to inhibition of myofibroblastic activity.

Methods and Results— We performed a high-resolution genome-wide association study of serum soluble E-selectin levels in 685 white individuals with type 1 diabetes from the Diabetes Control and Complications Trial (DCCT)/Epidemiology of Diabetes Intervention and Complications (EDIC) study to identify major loci influencing levels. Highly significant evidence for association (P=10^–29) was observed for rs579459 near the ABO blood group gene, accounting for 19% of the variance in E-selectin levels. Levels of E-selectin were higher in O/O than O/A heterozygotes, which were likewise higher than A/A genotypes. Analysis of subgroups of A alleles reveals heterogeneity in the association, and even after this was accounted for, an intron 1 SNP remained significantly associated. We replicate the ABO association in nondiabetic individuals.

Conclusion— ABO is a major locus for serum soluble E-selectin levels. We excluded population stratification, fine-mapped the association to sub-A alleles, and also document association with additional variation in the ABO region.

Methods and Results— Statistical analysis was undertaken in 2000 healthy middle aged men (NPHSII). Higher soluble EPCR levels were confirmed for Gly allele carriers (P<0.0001). Significantly higher levels of FVII, FVIIa, and downstream markers of activated coagulation in the extrinsic pathway (FIX activation pep [FIXpep]; FX activation pep [FXpep]), and prothrombin F1+2 (F1+2) were identified in baseline samples, in Gly carriers compared to Ser/Ser (P<=0.04 for trend). In repeat samples collected for up to 5 years, levels of FVII and F1+2 were higher in Gly allele carriers compared to Ser/Ser by (FVII: 6.9% CI 5.5 to 8.4 in Ser/Gly; and 23.4% CI 16.3 to 30.8 in Gly/Gly, P<0.0001), (F1+2: 8.1% CI 5.2 to 11.1 in Ser/Gly; 25.2% CI 11.8 to 40.3 in Gly/Gly, P<0.04), confirming reproducibility of findings at baseline. Molar ratios for FIXpep, FXpep, and F1+2 to FVIIa were constant in Ser/Ser and Ser/Gly but tended to be higher in Gly/Gly, reaching statistical significance for FIXpep:FVIIa (P=0.04).

Conclusions— These data suggest that higher levels of FVII and FVIIa circulate when EPCR shedding is greatest. Furthermore, these results suggest consequences for activation of extrinsic coagulation.

Methods and Results— We tested whether combinations of lipoprotein subfractions independently predict CVD in a prospective cohort of 4594 initially healthy men and women (the Malmö Diet and Cancer Study, mean follow-up 12.2 years, 377 incident cardiovascular events). Plasma lipoproteins and lipoprotein subfractions were measured at baseline with a novel high-resolution ion mobility technique. Principal component analysis (PCA) of subfraction concentrations identified 3 major independent (ie, zero correlation) components of CVD risk, one representing LDL-associated risk, a second representing HDL-associated protection, and the third representing a pattern of decreased large HDL, increased small/medium LDL, and increased triglycerides. The last corresponds to the previously described "atherogenic lipoprotein phenotype." Several genes that may underlie this phenotype—CETP, LIPC, GALNT2, MLXIPL, APOA1/A5, LPL—are suggested by SNPs associated with the combination of small/medium LDL and large HDL.

Conclusion— PCA on lipoprotein subfractions yielded three independent components of CVD risk. Genetic analyses suggest these components represent independent mechanistic pathways for development of CVD.

Methods and Results— Coregistration of FMT and CT was achieved with a multimodal imaging cartridge containing fiducial markers detectable by both modalities. A high-resolution CT angiography protocol accurately localized fluorescence to the aortic root of atherosclerotic apoE^–/– mice. To identify suitable sensors, we first modeled signal kinetics in-silico and then compared 3 probes with oligo-l-lysine cleavage sequences: PS-5, 5 nm in diameter containing 2 fluorochromes, PS-25, a 25-nm version with an elongated lysine chain and PS-40, a polymeric nanoparticle. Serial FMT-CT showed fastest kinetics for PS-5 but, surprisingly, highest fluorescence in lesions of the aortic root for PS-40. PS-40 robustly reported therapeutic effects of atorvastatin, corroborated by ex vivo imaging and qPCR for the model protease cathepsin B.

Conclusions— FMT-CT is a robust and observer-independent tool for noninvasive assessment of inflammatory murine atherosclerosis. Reporter-containing nanomaterials may have unique advantages over small molecule agents for in vivo imaging.

Methods and Results— Apo E^–/– mice maintained on a high-fat diet underwent continuous infusion with angiotensin II at 1000 ng/kg/min (Ang II) or vehicle (Control) via subcutaneous osmotic pump. Serial transabdominal ultrasound measurements of abdominal aortic diameter were recorded (n=16 mice, 3 to 4 time points per mouse) for up to 28 days. Near-infrared receptor fluorescent (NIRF) imaging was performed on Ang II mice (n=9) and Controls (n=5) with scVEGF/Cy, a single-chain VEGF homo-dimer labeled with Cy5.5 fluorescent tracer (7 to 18 µg/mouse IV). NIRF with inactivated single chain VEGF/Cy tracer (scVEGF/In, 18 µg/mouse IV) was performed on 2 additional Ang II mice to control for nonreceptor-mediated tracer binding and uptake. After image acquisition and sacrifice, aortae were harvested for analysis. An additional AAA mouse cohort received either an oral angiogenesis inhibitor or suitable negative or positive controls to clarify the significance of angiogenesis in experimental aneurysm progression. Aneurysms developed in the suprarenal aortic segment of all Ang II mice. Significantly greater fluorescent signal was obtained from aneurysmal aorta as compared to remote, uninvolved aortic segments in Ang II scVEGF/Cy mice or AAA in scVEGF/In mice or suprarenal aortic segments in Control mice. Signal intensity increased in a diameter-dependent fashion in aneurysmal segments. Immunostaining confirmed mural VEGFR-2 expression in medial smooth muscle cells. Treatment with an angiogenesis inhibitor attenuated AAA formation while decreasing mural macrophage infiltration and CD-31⁺ cell density.

Conclusion— Mural VEGFR expression, as determined by scVEGF/Cy fluorescent imaging and VEGFR-2 immunostaining, increases in experimental AAAs in a diameter-dependent fashion. Angiogenesis inhibition limits AAA progression. Clinical VEGFR expression imaging strategies, if feasible, may improve real-time monitoring of AAA disease progression and response to suppressive strategies.

Methods and Results— Hypertrophied white adipocytes surrounded abdominal aortas, whereas brown adipocytes surrounded thoracic aortas of obese mice. mRNA abundance of macrophage proinflammatory chemokines and their receptors were elevated with obesity to a greater extent in abdominal compared to thoracic periaortic adipose tissue. Periaortic adipose tissue explants surrounding abdominal aortas of obese mice released greater concentrations of MCP-1 and promoted more macrophage migration than explants from thoracic aortas. Male C57BL/6 mice were fed a high-fat (HF) diet for 1, 2, or 4 months and then infused with AngII (1000 ng/kg/min) for 28 days. AAA incidence increased progressively with the duration of HF feeding (18%, 36%,and 60%, respectively). Similarly, AngII-infused ob/ob mice exhibited increased AAAs compared to lean controls (76% compared to 32%, respectively, P<0.05). Infusion of AngII to obese mice promoted further macrophage infiltration into periaortic and visceral adipose tissue, and obese mice exhibiting AAAs had greater macrophage content in visceral adipose tissue than mice not developing AAAs.

Conclusions— Increased macrophage accumulation in periaortic adipose tissue surrounding abdominal aortas of AngII-infused obese mice is associated with enhanced AAA formation.

Methods and Results— Diabetes increased the expression of vascular cell adhesion molecule (VCAM)-1 in cerebral arteries >150 µm in diameter as well as the macrophage accumulation in aortic root atherosclerotic plaques in apoE^–/– mice. A more pronounced vascular inflammatory response was observed in diabetic TNF-deficient apoE^–/– mice. These mice were also characterized by increased accumulation of IgG and IgM autoantibodies in atherosclerotic lesions. Diabetes also increased VCAM-1 expression and plaque formation in apoE-competent TNF^–/– mice, whereas no such effects were observed in C57BL/6 wild-type mice.

Conclusions— The present findings suggest that TNF does not mediate diabetic-induced vascular inflammation in mice and reveal an unexpected protective role for TNF. These effects are partly attributable to a direct antiinflammatory role of TNF, but may also reflect a defective development of the immune system in these mice.

Methods and Results— Ovariectomized monkeys (n=34) consumed atherogenic diets for 30 months which contained either no hormones (control, n=17) or conjugated equine estrogens (CEE, n=17) at a human dose equivalent of 0.625 mg/d. Hepatic cholesterol content, low-density lipoprotein (LDL) receptor expression, cholesterol 7-hydroxylase and acyl-coenzyme A:cholesterol acyltransferase (ACAT) activity, and expression levels were determined. CEE treatment resulted in lower plasma concentrations of very-low- and intermediate- density lipoprotein cholesterol (V+IDLC; P=0.01), smaller LDL particles (P=0.002), and 50% lower hepatic cholesterol content (total, free, and esterified; P<0.05 for all). Total ACAT activity was significantly lower (P=0.01), explained primarily by reductions in the activity of ACAT2. Estrogen regulation of enzymatic activity was at the protein level as both ACAT1 and 2 protein, but not mRNA levels, were lower (P=0.02 and <0.0001, respectively). ACAT2 activity was significantly associated with hepatic total cholesterol, plasma V+IDLC cholesterol, and atherosclerosis.

Conclusions— Atheroprotective effects of estrogen therapy may be related to reduced hepatic secretion of ACAT2-derived cholesteryl esters in plasma lipoproteins.

Methods and Results— Hypercholesterolemic apoe^–/– mice were treated with recombinant 15 mg/kg OPG or vehicle injections twice a week for 10 consecutive weeks. Mice treated with OPG showed increased amounts of smooth muscle cells and collagen within the atherosclerotic lesions. OPG treatment did not affect atherosclerotic lesion size (8.2% versus 7.6%) or total vessel area but led to a 250% increase in lesion collagen, formation of mature collagen fibers in subendothelial fibrous caps, and upregulated mRNA for lysyl oxidase that promotes collagen crosslinking. In cell culture studies, OPG promoted cell proliferation in rat aortic smooth muscle cells. In contrast, OPG treatment did not affect markers of vascular or systemic inflammation.

Conclusion— OPG treatment promotes smooth muscle accumulation, collagen fiber formation, and development of fibrous caps but does not affect inflammatory properties of atherosclerotic lesions. Its effects may contribute to plaque stabilization.

Methods and Results— ApoE^o mice transplanted with bone marrow from LDLR^o/CD36^o mice had significantly less aortic lesion compared with those transplanted with LDLR^o marrow. Reciprocal macrophage transfer into hyperlipidemic apoE^o and LDLR^o animals showed that foam cell formation induced by in vivo modified lipoproteins was dependent on the lipoprotein, not macrophage type. LDLR^o and LDLR^o/CD36^o mice were fed a cholesterol-enriched diet (HC), and we observed significant lesion inhibition in LDLR^o/CD36^o mice. LDL/plasma isolated from HC-fed LDLR^o mice induced significantly greater jnk phosphorylation, cytokine release, and reactive oxygen species secretion than LDL/plasma from WD-fed LDLR^o mice, and this was CD36-dependent. HC-fed LDLR^o mice had higher circulating levels of cytokines than WD-fed mice.

Conclusions— These data support the hypothesis that CD36-dependent atherogenesis is contingent on a proinflammatory milieu that promotes the creation of specific CD36 ligands, not solely hypercholesterolemia, and may explain the greater degree/accelerated rate of atherosclerosis observed in syndromes associated with inflammatory risk.

Methods and Results— Using wild-type and LXR/β-deficient mice, we show here that bexarotene induces hypertriglyceridemia and activates hepatic LXR-target genes of lipogenesis in an LXR-dependent manner, hence exerting a permissive effect on RXR/LXR heterodimers. Interestingly, RNA analysis and Chromatin Immunoprecipitation assays performed in the liver reveal that the in vivo permissive effect of bexarotene on the RXR/LXR heterodimer is restricted to lipogenic genes without modulation of genes controlling cholesterol homeostasis.

Conclusion— These findings demonstrate that the hypertriglyceridemic action of bexarotene occurs via the RXR/LXR heterodimer and show that RXR heterodimers can act with a selective permissivity on target genes of specific metabolic pathways in the liver.

Methods and Results— WT apoA-I– or apoA-I_M–expressing mice were intraperitoneally injected with [H³]cholesterol-labeled J774 mouse macrophages. After 48 hours, no significant difference was detected in the amount of cholesterol removed from the macrophages and deposited in the feces via the RCT pathway between the WT apoA-I and apoA-I_M groups. Analysis of the individual components of the RCT pathway demonstrated that the apoA-I_M–expressing mice promoted ATP-binding cassette transporter A1 (ABCA1)-mediated cholesterol efflux as efficiently as WT apoA-I but that apoA-I_M had a reduced ability to promote cholesterol esterification via lecithin cholesterol-acyltransferase (LCAT). This resulted in reduced cholesteryl ester (CE) and increased free cholesterol (FC) levels in the plasma of mice expressing apoA-I_M compared to WT apoA-I. These differences did not affect the rate of delivery of labeled cholesterol to the liver via SR-BI–mediated selective uptake or its subsequent excretion in the feces.

Conclusion— Within the limits of the in vivo assay, WT apoA-I and apoA-I_M are equally efficient at promoting macrophage RCT, suggesting that if apoA-I_M is more atheroprotective than WT apoA-I it is not attributable to an enhancement of macrophage RCT.

Methods and Results— C57BL/6J mice were fed a FO diet, whereas control mice were fed diets containing alternative sources of fats, soybean oil (SO), and coconut oil (CO) for 4 weeks. Macrophage RCT was assessed by injecting [³H]cholesterol-labeled J774 macrophages intraperitoneally into mice. After 48 hours, tissues were harvested and feces were collected. An increase in the excretion of macrophage-derived [³H]-tracer recovered in fecal neutral sterols for FO-fed mice was observed (273% versus SO and 182% versus CO). FO also decreased [³H]-tracer in hepatic cholesteryl ester compared to SO and CO by 76% and 56%, respectively. To specifically determine the effect of FO on the fate of HDL-derived cholesterol, mice fed FO or SO diets were injected with HDL labeled with [³H]cholesteryl oleate, and the disappearance of [³H]-tracer from blood and its excretion in feces was measured. There was no significant difference in the fractional catabolic rate of [³H]cholesteryl oleate-HDL between the 2 groups. However, there was a 242% increase in the excretion of HDL-derived [³H]-tracer recovered in fecal neutral sterols in FO-fed mice, concordant with significantly increased expression of hepatic Abcg5 and Abcg8 mRNA.

Conclusion— As measured by this tracer-based assay, FO promoted reverse cholesterol transport, primarily by enhancement of the hepatic excretion of macrophage-derived and HDL-derived cholesterol.

Methods and Results— Pretreatment of mice with soluble JAM-C (sJAM-C), used as a pharmacological blocker of JAM-C-mediated reactions, significantly suppressed leukocyte migration in models of kidney and cremaster muscle I/R injury (39 and 51% inhibition, respectively). Furthermore, in the cremaster muscle model (studied by intravital microscopy), both leukocyte adhesion and transmigration were suppressed in JAM-C-deficient mice (JAM-C^–/–) and enhanced in mice overexpressing JAM-C in their endothelial cells (ECs). Analysis of JAM-C subcellular expression by immunoelectron microscopy indicated that in I/R-injured tissues, EC JAM-C was redistributed from cytoplasmic vesicles and EC junctional sites to nonjunctional plasma membranes, a response that may account for the role of JAM-C in both leukocyte adhesion and transmigration under conditions of I/R injury.

Conclusions— The findings demonstrate a role for EC JAM-C in mediating leukocyte adhesion and transmigration in response to I/R injury and indicate the existence of a novel regulatory mechanism for redistribution and hence function of EC JAM-C in vivo.

Methods and Results— In GC-A–deficient mice (GC-A-KO), hind-limb ischemia resulted in autoamputation or severe ulcers in 60% of mice (6/10) during the 28-day observation period. In wild-type (WT) mice, partial amputation or mild ulcers were detected in only 20% of mice (2/10). Laser Doppler perfusion imaging revealed that the recovery of blood flow in the ischemic limb was significantly inhibited in GC-A-KO mice compared with WT mice. Immunostainings with anti–PECAM-1 antibody demonstrated that, in GC-A-KO, the capillary density of the ischemic tissue was significantly diminished compared to WT. Furthermore, bone marrow transplantation showed the predominant role of GC-A on local ischemic tissue rather than on vascular progenitor cells mobilized from bone marrow during vascular remodeling. In cultured human endothelial cells, ANP treatment significantly stimulated mRNA expressions of vascular endothelial growth factor and endothelial nitric oxide synthase via Erk1/2-dependent mechanism.

Conclusion— These results suggest that endogenous ANP and BNP play important roles in reparative vascular remodeling in ischemic tissue.

Methods and Results— To mimic a clinical situation of increased oxidative stress, mice were exposed to cigarette smoke before and after the surgical induction of hindlimb ischemia. Nox2 expression and oxidative stress in ischemic tissues were significantly increased in wild-type mice, but not in mice deficient for the Nox2-containing NADPH oxidase (Nox2^–/–). Nox2^–/– mice demonstrated faster blood flow recovery, increased capillary density in ischemic muscles, and improved endothelial progenitor cell functional activities compared to Nox2^+/+ mice. In addition, Nox2 deficiency was associated with increased antioxidant and nitrite concentrations in plasma, together with a preserved expression of eNOS in ischemic tissues. In vitro, Nox2^–/– endothelial cells exhibit resistance against superoxide induction and improved VEGF-dependent angiogenic activities compared to Nox2^+/+ endothelial cells. Importantly, the beneficial effects of Nox2 deficiency on neovascularization in vitro and in vivo were lost after treatment with the NO inhibitor L-NAME.

Conclusions— Nox2-containing NADPH oxidase deficiency protects against ischemia in conditions of increased oxidative stress. The mechanism involves improved neovascularization through a reduction of ROS formation, preserved activation of the VEGF/NO angiogenic pathway, and improved functional activities of endothelial progenitor cells.

Methods and Results— We generated BM chimeric apoE^–/– mice repopulated with AT₁-deficient (Agtr1^–/–) or wild-type (Agtr1^+/+) BM cells. The atherosclerotic development was significantly reduced in apoE^–/–/BM-Agtr1^–/– mice compared with apoE^–/–/BM-Agtr1^+/+ mice, accompanied by decreased numbers of BM granulocyte/macrophage progenitors (GMP:c-Kit⁺Sca-1^–Lin^–CD34⁺CD16/32⁺) and peripheral blood monocytes. Macrophage-colony-stimulating factor (M-CSF)–induced differentiation from hematopoietic stem cells (HSCs:c-Kit⁺Sca-1⁺Lin^–) to promonocytes (CD11b^highLy-6G^low) was markedly reduced in HSCs from Agtr1^–/– mice. The expression of M-CSF receptor c-Fms was decreased in HSCs/promonocytes from Agtr1^–/– mice, accompanied by a marked inhibition in M-CSF–induced phosphorylation of PKC- and JAK2. c-Fms expression in HSCs/promonocytes was mainly regulated by TNF- derived from BM CD45^–CD34^– stromal cells, and Ang II specifically regulated the TNF- synthesis and release from BM stromal cells.

Conclusions— Ang II regulates the expression of c-Fms in HSCs and monocyte-lineage cells through BM stromal cell–derived TNF- to promote M-CSF–induced differentiation/proliferation of monocyte-lineage cells and contributes to the proatherogenic action.

Methods and Results— In a rabbit model of aortic balloon injury, pharmacological induction of HO-1 enhanced reendothelialization at sites with and without adjacent blood vessels, the latter indicative of a contribution by EPCs. Coinciding with maximal HO-1 induction in the injured vessel, plasma concentrations of bilirubin and the numbers of circulating progenitor cells were elevated. Both processes were abolished by cotreatment of the animals with an inhibitor of HO-1. Inducers of HO-1 promoted bone marrow cells to form progenitor cell colonies, and Flk1⁺/Sca-1⁺-cells to adhere to the luminal surface of the injured vessel. In noninjured mice, HO-1 inducers also increased bone marrow and circulating EPCs, and the ability of these cells to differentiate and form colonies. Compared to wild-type mice, bone marrow cells from HO-1^–/– mice generated fewer endothelial colony-forming cells, and HO-1 inducers failed to promote CFU-Hill colony formation.

Conclusions— These findings suggest that HO-1 contributes to vascular repair by increasing circulating EPCs derived from the bone marrow.

Methods and Results— The respective roles of endothelial and hematopoietic targets of E2 were investigated in a mouse carotid injury model, using confocal microscopy, to follow endothelium repair. Grafting ER^–/– mice with ER^+/+ bone marrow (BM) was not sufficient to restore the accelerative effect of E2 on reendothelialization, demonstrating the necessary role of extrahematopoietic ER. Using an endothelial-specific inactivation of ER (Cre-Lox system), we showed that endothelial ER plays a pivotal role in this E2 action. Conversely, in ER^+/+ grafted with ER^–/– BM, the E2 regenerative effect was abolished, demonstrating that ER-expressing hematopoietic cells are also needed. As eNOS expression in BM was required for this action, both endothelial progenitor cells and platelets could be the hematopoietic targets that participate to this beneficial E2 effect.

Conclusions— We demonstrate that endothelial ER plays a pivotal role in E2-mediated reendothelialization. However, endothelial targeting alone is not sufficient because the concomitant stimulation of a subpopulation of BM ER is necessary. This cooperation should be taken into account in strategies aimed at optimizing in-stent reendothelialization.

Methods and Results— 129X1/SvJ mice developed significantly more neointima and late lumen loss compared to C57BL/6 mice. Gene expression analysis of intimal tissue revealed major differences in the expression of inflammatory and hematopoietic stem and progenitor cell–associated genes in response to arterial injury. In 129X1/SvJ mice stronger mobilization of lin^–sca-1⁺CXCR4⁺ cells was observed after vascular injury. Bone marrow transplantation identified the extent of neointima formation as clearly dependent on the genetic background of BMCs (ie, mice with 129X1/SvJ BMCs developed more intimal hyperplasia). The inflammatory response and the recruitment of BMCs to the site of arterial injury were significantly increased in mice with 129X1/SvJ BMCs.

Conclusions— The genetically controlled mechanisms leading to lumen narrowing in vascular remodeling are dependent on mobilization and recruitment capacities of particular BMCs.

Methods and Results— Adenovirus-mediated overexpression of clusterin (Ad-Clu) repressed TNF-–stimulated expression of MCP-1, fractalkine, ICAM-1, VCAM-1, and MMP-9, leading to inhibition of VSMC migration. Both Ad-Clu and secreted clusterin suppressed VSMC proliferation by inhibiting DNA synthesis, but not by inducing apoptosis. Ad-Clu upregulated p53 and p21^cip1/waf1 but downregulated cyclins D and E, leading to suppression of pRb phosphorylation and subsequent induction of G1 arrest in VSMCs. Clusterin deficiency augmented VSMC proliferation in vitro and accelerated neointimal hyperplasia in vivo, but concomitantly impaired reendothelialization in wire-injured murine femoral arteries. Moreover, Ad-Clu significantly reduced neointimal thickening in balloon-injured rat carotid arteries. Clusterin also diminished TNF-–induced apoptosis of human umbilical vein endothelial cells and restored endothelial nitric oxide synthase expression suppressed by TNF-.

Conclusion— These results suggest that upregulation of clusterin during vascular injury may be a protective response against, rather than a causative response to, the development of neointimal hyperplasia.

Methods and Results— Rats underwent carotid artery injury and received intraperitoneal injections of saline or mutant forms of PAI-1 for 14 days, including an active stable mutant (PAI-1-14-1b), a mutant lacking anti-PA activity (PAI-1-R), or a mutant defective in vitronectin (VN) binding (PAI-1-K). All forms of PAI-1 significantly inhibited neointima formation, whereas elastase-cleaved PAI-1, which lacks both anti-PA and VN-binding functions, did not. Similar effects were observed in a murine model. However, the antiproliferative effect of PAI-1-R was lost in Vn^–/– mice, suggesting that PAI-1 can inhibit intimal hyperplasia in vivo by a VN-dependent pathway not involving direct inhibition of proteases. In vitro, recombinant PAI-1 inhibited wild-type vascular smooth muscle cell (VSMC) proliferation, promoted apoptosis, and inhibited migration. These effects were lost in VN-deficient VSMCs.

Conclusion— Recombinant PAI-1 inhibits intimal hyperplasia by inhibiting proteases and binding VN. VN is a key determinant of the antiproliferative effect of PAI-1 overexpression. PAI-1-R has therapeutic potential to inhibit vascular restenosis without promoting thrombosis.

Methods and Results— Two weeks on the kDa increased plasma levels of free fatty acids and ketones accompanied by hypoglycemia in mice. Plasma PAI-1 concentrations were extremely elevated in accordance with mRNA expression levels in the heart and liver, but not in the kidneys of KD mice. Circadian expression of PAI-1 mRNA was phase-advanced for 4.7, 7.9, and 7.8 hours in the heart, kidney, and adipose tissues, respectively, as well as that of circadian genes mPer2 and DBP in KD mice, suggesting that peripheral clocks were phase-advanced by ketosis despite feeding ad libitum under a periodic light-dark cycle. The circadian clock that regulates behavioral activity rhythms was also phase-advanced, and its free-running period was significantly shortened in KD mice.

Conclusions— Our findings suggest that ketogenic status increases hypofibrinolytic risk by inducing abnormal circadian expression of PAI-1.

Methods and Results— We evaluated effects of BAY 41-2272 and BAY 58-2667 on expression and activity of TF in human monocytes and umbilical vein endothelial cells (HUVECs). Both compounds reduced expression of active TF protein in monocytes stimulated with lipopolysaccharide, as demonstrated by immunoblotting and a TF procoagulant activity assay. In-cell Western assay revealed that this effect was associated with a marked reduction of total and surface TF presentation. Furthermore, BAY 41-2272 and BAY 58-2667 decreased TF protein expression and the TF-dependent procoagulant activity in HUVECs stimulated with TNF-. The sGC agonists also suppressed transcriptional activity of NF-B. A siRNA-mediated knockdown of the 1-subunit of sGC in monocytes and HUVECs confirmed that the inhibitory effect of BAY 41-2272 and BAY 58-2667 on TF expression is mediated through the sGC-dependent mechanisms.

Conclusions— Inhibition of TF expression and activity by sGC agonists might provide therapeutic benefits in cardiovascular diseases associated with enhanced procoagulant and inflammatory response.

Methods and Results— Proteasome inhibitors as a class markedly induced the expression of thrombomodulin and enhanced the protein C activating capacity of endothelial cells. Thrombomodulin upregulation was independent of NF-B signaling, a principal target of proteasome inhibitors, but was instead a direct consequence of increased expression of the Krüppel-like transcription factors, KLF2 and KLF4. These effects were confirmed in vivo, where systemic administration of a proteasome inhibitor enhanced thrombomodulin expression that was paralleled by changes in the expression of KLF2 and KLF4.

Conclusions— These findings identify a novel mechanism of action of proteasome inhibitors that may help to explain their clinically observed thromboprotective effects.

Methods and Results— Normal rat VSMCs were used. First, Western blotting and RT-PCR analyses showed that thrombin induces the expression of EGFR at transcription and translation levels in VSMCs. Second, pharmacological inhibitors, dominant negative mutants, and short hairpin RNA interference (shRNA) technology enabled us to demonstrate that thrombin-induced EGFR expression is mediated through PKC()/c-Src-dependent transactivation of EGFR linking to PI3K/Akt and ERK1/2. We further investigated whether the transcription factors AP-1 and NF-B are involved in this response by a promoter assay. Finally, data obtained by using EGFR shRNA technology and XTT assay demonstrated that thrombin-enhanced VSMC proliferation was mediated through upregulation of EGFR.

Conclusions— Our results demonstrate that thrombin-enhanced VSMC proliferation was mediated through upregulation of EGFR via a PKC()/c-Src-dependent transactivation of EGFR, PI3K-Akt, and ERK, and AP-1/NF-B pathway.

Methods and Results— Platelet adhesion to immobilized FXI was abrogated in the presence of the low-density lipoprotein (LDL) receptor antagonist, receptor-associated protein (RAP), soluble recombinant apolipoprotein E receptor 2 (ApoER2), or the LDL-binding domain 1 or 2 of ApoER2. FXI supported wild-type murine platelet binding; in contrast, ApoER2-deficient murine platelets did not adhere to FXI. In the presence of shear, platelet aggregates formed on FXI or activated FXI (FXIa) surfaces, whereas the presence of RAP, binding domain 1 of ApoER2, or an anti-GPIb mAb blocked platelet adhesion to FXI or FXIa under shear. Soluble FXI bound to immobilized ApoER2' with an affinity of 61 nmol/L.

Conclusions— This study has identified apolipoprotein E receptor 2 (ApoER2, LRP8), a member of the LDL receptor family, as a platelet receptor for FXI. The interaction of FXI with other cell types that express ApoER2 remains to be explored.

Methods and Results— Human ATL subsets were characterized by flow cytometry in subcutaneous ATs from 92 individuals with body mass index (BMI) ranging from 19 to 43 kg/m² and in paired biopsies of subcutaneous and visceral AT from 45 class II/III obese patients. CD3⁺ ATLs were composed of effector and memory CD4⁺ helper and CD8⁺ cytotoxic T cells. The number of ATLs correlated positively with BMI and was higher in visceral than subcutaneous AT. Mature adipocytes stimulated the migration of ATLs and released the chemokine CCL20, the receptor of which (CCR6) was expressed in ATLs. The expression of adipocyte CCL20 was positively correlated with BMI and increased in visceral compared to subcutaneous adipocytes. ATLs expressed inflammatory markers and released interferon gamma (IFN). Progenitor and adipocyte treatment with ATL-conditioned media reduced the insulin-mediated upregulation of lipogenic enzymes, an effect involving IFN.

Conclusions— Therefore, crosstalk occurs between adipocytes and lymphocytes within human AT involving T cell chemoattraction by adipocytes and modulation of lipogenesis by ATLs.

Methods and Results— AgLDL resides for prolonged periods in surface-connected compartments. Although agLDL is still extracellular, we demonstrate that an increase in free cholesterol occurs at sites of contact between agLDL and cells because of hydrolysis of agLDL-derived cholesteryl ester. This increase in free cholesterol causes enhanced actin polymerization around the agLDL. Inhibition of cholesteryl ester hydrolysis results in decreased actin polymerization.

Conclusions— We describe a novel process that occurs during agLDL–macrophage interactions in which local release of free cholesterol causes local actin polymerization, promoting a pathological positive feedback loop for increased catabolism of agLDL and eventual foam cell formation.

Methods and Results— In ex vivo or in vitro models as well as in intact animals, administration of cLDL was associated with endothelial internalization of cLDL and subendothelial translocation (transcytosis). In vitro recombinant LOX-1 and SREC-1 receptors showed the greatest cLDL binding. However, pretreatment of the endothelial cells with specific inhibiting antibodies demonstrated that cLDL binds mainly to LOX-1 and CD36 receptors. The transcytosis was dependent on SR-A1, SREC-1, and CD36 receptors whereas LOX-1 receptor was not involved. The cytotoxicity was mediated by several studied scavenger receptors, but cLDL-induced monocyte adhesion depended only on LOX-1. The cLDL-induced synthesis of LOX-1 protein significantly contributed to both cytotoxicity and accelerated monocyte adhesion to endothelial cells.

Conclusions— Our data suggest that cLDL uses a unique pattern of scavenger receptors. They show that LOX-1 receptor, and partially CD36, SREC-1, and SR-A1 receptors, are essential for the proatherogenic effects of cLDL on human endothelial cells.

Methods and Results— SMCs were cultured on either fibrillar or monomer collagen for 48 hours and [¹⁴C]-acetate incorporation into cholesterol was evaluated. Fibrillar collagen reduced by 72.9±2.6% cholesterol biosynthesis without affecting cellular cholesterol levels. Fibrillar collagen also reduced 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMG-CoA) promoter activity (–72.6±7.3%), mRNA (–58.7±6.4%), protein levels (–35.5±8.5%), and enzyme activity (–37.7±2.2%). Intracellular levels of the active form of sterol regulatory element binding proteins (SREBP) 1a was decreased by 60.7±21.7% in SMCs cultured on fibrillar collagen, whereas SREBP2 was not significantly affected (+12.1±7.1%). The overexpression of the active form of SREBP1a rescued the downregulation of fibrillar collagen on HMG-CoA reductase levels. Blocking antibody to 2 integrin partially reversed the downregulation of HMG-CoA reductase mRNA expression. Finally, fibrillar collagen led to an intracellular accumulation of unprenylated Ras.

Conclusions— Our study demonstrated that 2β1 integrin interaction with fibrillar collagen affected the expression of HMG-CoA reductase, which led to the inhibition of cholesterol biosynthesis in human SMCs.

Methods and Results— We identified 1008 bp of the OPG 5'-flanking region to be sufficiently transcriptionally active in osteosarcoma cell lines and generated serial promoter deletion constructs. Individual subcloning revealed the existence of 3 molecular haplotypes (MolHaps): [T^–960-A^–946-G^–900-T^–864; MolHap1, wild type], [T^–960-G^–946-G^–900-T^–864; MolHap2], [C^–960-G^–946-A^–900-G^–864; MolHap4]. Compared to MolHap1, transcriptional activities of MolHaps 2 and 4 were significantly reduced (P=0.0018). Whereas introduction of the –159C allele reduced transcriptional activities of the full-length constructs (P=0.0014), it significantly increased activities of the deletion constructs (P=0.0005). Electrophoretic mobility shift, competition, and chromatin immunoprecipitation assays revealed specific DNA:protein interactions for the MolHaps with Sp1 and NF-1, and identified Egr1 interacting exclusively with the –159T allele.

Conclusions— We propose new structural and transcriptional features within the OPG promoter region and identified MolHaps being differentially transcriptionally active and allele-dependently interacting with a proximal polymorphic site.

Methods and Results— Carotid ligation injury was performed in wild-type and S1P2R-null mice. At various time points after injury, expression of multiple SMC differentiation genes, myocardin, and S1P receptors (S1P1R, S1P2R, and S1P3R) was measured by quantitative PCR. These experiments demonstrate that at day 7 after injury, S1P2R specifically regulates expression of smooth muscle -actin (SMA) and that this is not mediated by changes in expression of myocardin or any of the S1PRs. In vitro studies using carotid SMCs prepared from wild-type and S1P2R-null mice show that S1P stimulates expression of all SMC-differentiation genes tested, but S1P2R significantly regulates expression of SMA and SM22 only. Chromatin immunoprecipitation assays suggest that S1P-induced recruitment of serum response factor to the SMA promoter and enhancer largely depends on S1P2R. S1P-stimulated SMA expression requires S1P2R-dependent activation of RhoA and mobilization of calcium from intracellular stores. Chelation of calcium does not affect the activation of RhoA by S1P, whereas blockade of Rho by C3 exotoxin partially inhibits the mobilization of calcium by S1P.

Conclusions— The results of this study support the hypothesis that S1P2R regulates expression of SMA after injury. We further conclude that transcriptional regulation of SMA by S1P in vitro requires S1P2R-dependent activation of RhoA and mobilization of calcium from intracellular calcium stores.

Methods and Results— Using coronary microvascular endothelial cells isolated from wild-type and p47^phox knockout mice, we found that knockout of p47^phox increased the level of p40^phox expression, whereas depletion of p40^phox in wild-type cells increased p47^phox expression. In both cases, the basal ROS production (without agonist stimulation) was well preserved. Double knockout of p40^phox and p47^phox dramatically reduced (65%) ROS production and cells started to die. The transcriptional regulation of p40^phox and p47^phox expressions involves HBP1. p40^phox was prephosphorylated in resting cells. PMA stimulation induced p40^phox swift dephosphorylation (within 1 minute) in parallel with the start of p47^phox phosphorylation. p40^phox was then rephosphorylated, and this was accompanied with an increase in ROS production. Depletion of p40^phox resulted in 67% loss in agonist-induced ROS production despite the presence of p47^phox. These were further supported by experiments on mouse aortas stimulated with angiotensin II.

Conclusion— p40^phox is prephosphorylated in resting endothelial cells and can compensate p47^phox in keeping basal ROS production. Dephosphorylation of p40^phox is a prerequisite for agonist-induced p47^phox phosphorylation, and p40^phox through its dynamic dephosphorylation and rephosphorylation is involved in the regulation of agonist-induced ROS production.

Methods and Results— Adenoviral vectors were used to manipulate the expression of regulator of G protein signaling (RGS) domain containing Rho-specific guanine exchange factors (RhoGEFs) and proline-rich tyrosine kinase 2 (PYK2), a nonreceptor tyrosine kinase, in primary rat vascular smooth muscle cells. As an evidence of RhoA activation, RhoA translocation and MYPT1 (the regulatory subunit of myosin light chain phosphatase) phosphorylation were analyzed by Western blot. Results showed that overexpression of PDZ-RhoGEF, but not p115-RhoGEF or leukemia-associated RhoGEF (LARG), enhanced RhoA activation by angiotensin II. Knockdown of PDZ-RhoGEF decreased RhoA activation by angiotensin II. PDZ-RhoGEF was phosphorylated and activated by PYK2 in vitro, and knockdown of PDZ-RhoGEF reduced RhoA activation by constitutively active PYK2, indicating that PDZ-RhoGEF links PYK2 to RhoA. Knockdown of PYK2 or PDZ-RhoGEF markedly decreased RhoA activation by A23187, a Ca²⁺ ionophore, demonstrating that PYK2/PDZ-RhoGEF couples RhoA activation to Ca²⁺.

Conclusions— PYK2 and PDZ-RhoGEF are necessary for angiotensin II–induced RhoA activation and for Ca²⁺ signaling to RhoA.

Methods and Results— We cultured primary human macrophages derived from peripheral blood monocytes in moderate hypoxia (2% O₂ tension) or normoxia (21% O₂) for 10 days. Moderate hypoxia did not affect macrophage differentiation assessed via expression levels of scavenger receptor A. Chronic moderate hypoxia, but not normoxia, activated Akt and inactivated GSK-3β, a negative effector of Akt, thus allowing nuclear translocation of β-catenin. 2% O₂ tension increased accumulation of hypoxia-inducible factors 1 (HIF-1) transiently at 3 to 5 days. Hypoxia induced mRNA expression of the β-catenin-associated genes: MMP-7, CD44, and c-Myc. RNAi of TCF7L2, a cofactor of β-catenin, suppressed MMP-7 expression induced by hypoxia. Inhibition of Akt phosphorylation with LY294002 abolished hypoxia-induced GSK-3β inactivation, β-catenin activation, and MMP-7 expression. Macrophages under hypoxia were more resistant for oxLDL-induced apoptosis. Moreover, phospho-Akt colocalized with MMP-7 and CD44 expression in macrophages of human atherosclerotic plaques.

Conclusions— Chronic moderate hypoxia induces macrophage activation via the Akt and β-catenin pathways, providing new insight into the pathogenesis of inflammatory diseases.

Methods and Results— We demonstrate that a conserved sequence within the 9p21.3 locus has enhancer activity and that the risk variant significantly increases reporter gene expression in primary aortic smooth muscle cells. Whole blood RNA expression of the short variants of ANRIL was increased by 2.2-fold whereas expression of the long ANRIL variant was decreased by 1.2-fold in healthy subjects homozygous for the risk allele. Expression levels of the long and short ANRIL variants were positively correlated with that of the cyclin-dependent kinase inhibitor, CDKN2B (p15) and TDGF1 (Cripto), respectively. Relevant to atherosclerosis, genome-wide expression profiling demonstrated upregulation of gene sets modulating cellular proliferation in carriers of the risk allele.

Conclusion— These findings are consistent with the hypothesis that the 9p21.3 risk allele contains a functional enhancer, the activity of which is altered in carriers of the risk allele. 9p21.3 may promote atherosclerosis by regulating expression of ANRIL, which in turn is associated with altered expression of genes controlling cellular proliferation pathways.

Methods and Results— We investigated whether the K121Q polymorphism is associated with increased PP in white Caucasians and with ED in vitro. In 985 individuals, (390 unrelated and 595 from 248 families), the K121Q polymorphism was associated with PP (P=8.0x10^–4). In the families, the Q121 variant accounted for 0.08 of PP heritability (P=9.4x10^–4). This association was formally replicated in a second sample of 475 individuals (P=2.6x10^–2) but not in 2 smaller samples of 289 and 236 individuals (P=0.49 and 0.21, respectively). In the individual patients’ data meta-analysis, comprising 1985 individuals, PP was associated with the Q121 variant (P=1.2x10^–3). Human endothelial cells carrying the KQ genotype showed, as compared to KK cells, reduced insulin-mediated insulin receptor autophosphorylation (P=0.03), Ser⁴⁷³-Akt phosphorylation (P=0.03), and NO synthase activity (P=0.003).

Conclusions— Our data suggest that the ENPP1 Q121 variant is associated with increased PP in vivo and reduced insulin signaling and ED in vitro, thus indicating a possible pathogenic mechanism for the increased cardiovascular risk observed in ENPP1 Q121 carriers.

Methods and Results— We measured sESAM, soluble intercellular adhesion molecule (sICAM)-1, and soluble vascular cell adhesion molecule (sVCAM)-1 in 3222 subjects participating in the Dallas Heart Study, a probability-based population sample. Coronary artery calcium (CAC) was measured by electron beam computed tomography, and abdominal aortic wall thickness (AWT), aortic plaque burden (APB), and aortic compliance (AC) by MRI. Increasing levels of sESAM were associated with all major cardiovascular risk factors as well as with inflammatory markers such as monocyte chemoattractant protein-1, but only weakly correlated with sICAM-1 and sVCAM-1. In multivariate analyses, sESAM was independently associated with prevalent CAC (OR 1.2 per SD increase, 95% CI 1.1 to 1.3; P=0.005), AWT (P=0.035), and AC (P=0.006), but not APB (P=0.15). In contrast, no independent associations were observed between sICAM-1 or sVCAM-1 and any of the atherosclerosis phenotypes.

Conclusions— In this first reported clinical study of sESAM in humans, sESAM levels were independently associated with CAC, AWT, and AC, whereas sICAM-1 and sVCAM-1 were not. These findings support a unique role of this cellular adhesion molecule in atherosclerosis and suggest the need for further exploration of sESAM as a predictive biomarker and potential mediator of atherosclerosis.

Methods and Results— Men and women from the general population (n=4691), without history of myocardial infarction or stroke, were examined. Incidence of hospitalizations attributable to heart failure was studied over a mean follow-up of 13 years. A total of 75 subjects were hospitalized with a primary diagnosis of heart failure. Adjusted for risk factors, the hazards ratios (95% CI) were 1.00, 0.98 (0.36 to 2.7), 1.9 (0.80 to 4.6), and 2.7 (1.1 to 6.2), respectively, for the 1st, 2nd, 3rd, and 4th quartiles of IMT (P for trend=0.003). The HR associated with CRP levels ≥3 mg/L (versus <1 mg/L) was 2.0 (95% CI: 1.06 to 3.9) after adjustments for risk factors. There was a significant interaction between IMT and CRP on heart failure incidence (P=0.028). Subjects with CRP ≥3 mg/L and IMT in the 4th quartile had an adjusted HR of 3.7 (1.9 to 7.1) compared to those with CRP <3 mg/L and IMT in quartile 1 to 3.

Conclusion— High IMT and high CRP are both independent risk factors for incidence of heart failure requiring hospitalization. The joint exposure to both risk factors substantially increases the risk.

Methods and Results— Seventy-seven patients with ≥50% carotid stenosis in at least one side by duplex ultrasound underwent bilateral multi-contrast carotid MRI scans. Measurements for wall and lipid-rich/necrotic core sizes, presence of hemorrhage, and fibrous cap status (classified as intact thick, intact thin or ruptured) were recorded. Arteries with poor image quality, occlusion, or no detectable lipid-rich/necrotic core were excluded. For the 798 MRI slices included, multivariate ordinal regression analysis demonstrated larger %lipid-rich/necrotic core (odds ratio for 10% increase, 1.49; P=0.02) and presence of hemorrhage (odds ratio, 5.91; P<0.001) were independently associated with a worse (intact thin or ruptured) stage of fibrous cap status. For artery-based multivariate analysis, a larger maximum %lipid-rich/necrotic core and presence of hemorrhage independently associated with worse fibrous cap status (P<0.001, for both). No hemorrhage was detected in arteries with thick fibrous caps.

Conclusion— Hemorrhage and larger %lipid-rich/necrotic core were independently associated with a thin or ruptured fibrous cap status at an early to advanced stage of carotid atherosclerosis.

Methods and Results— Endothelial function, arterial stiffness, carotid intima-media thickness, and analysis of atheromatous plaques were examined in 84 rheumatoid arthritis patients without cardiovascular disease versus healthy controls matched for age, sex, and traditional cardiovascular disease risk factors, as well as in 48 diabetes patients matched for age, sex, and disease duration with 48 rheumatoid arthritis patients. Rheumatoid arthritis duration associated with arterial stiffening, whereas disease activity associated with carotid plaque vulnerability. All markers of preclinical atherosclerosis were significantly worse in rheumatoid arthritis compared to controls, whereas they did not differ in comparison to diabetes despite a worse cardiovascular risk factor profile in diabetics. Both diseases were associated independently with increased intima-media thickness; rheumatoid arthritis, but not diabetes, was independently associated with endothelial dysfunction.

Conclusions— Preclinical atherosclerosis appears to be of equal frequency and severity in rheumatoid arthritis and diabetes of similar duration with differential impact of traditional risk factors and systemic inflammation. Cardiovascular disease risk factors in rheumatoid arthritis may need to be targeted as aggressively as in diabetes.

Methods and Results— We generated apolipoprotein E-null mice with transgenes that allow regulated overexpression of active TGF-β1 in their hearts. Compared to littermate controls, these mice had elevated cardiac and plasma TGF-β1, less aortic root atherosclerosis (P≤0.002), fewer lesions in the thoracic and abdominal aortae (P≤0.01), less aortic root dilation (P<0.001), and fewer pseudoaneurysms (P=0.02). Mechanistic studies revealed no effect of TGF-β1 overexpression on plasma lipids or cytokines, or on peripheral lymphoid organ cells. However, aortae of TGF-β1-overexpressing mice had fewer T-lymphocytes, more collagen, less lipid, lower expression of inflammatory cytokines and matrix metalloproteinase-13, and higher expression of tissue inhibitor of metalloproteinase-2.

Conclusions— When overexpressed in the heart and plasma, TGF-β1 is an antiatherogenic, vasculoprotective cytokine that limits atherosclerosis and prevents aortic dilation. These actions are associated with significant changes in cellularity, collagen and lipid accumulation, and gene expression in the artery wall.

Methods and Results— LRP1 knock-in mice carrying an inactivating mutation in the NPxYxxL motif were crossed with LDLR-deficient mice, a model for atherosclerosis. In this LDLR^–/– background the mutated mice showed a more atherogenic lipoprotein profile, which was associated with a decreased clearance of postprandial lipids because of a compromised endocytosis rate and reduced lipase activity. On an atherogenic diet LRP1 mutant mice revealed a 50% increased development of atherosclerosis. This aggravation was accompanied by an increase in smooth muscle cell (SMC) and collagen content and apoptotic cells in the lesions. The mutation showed, however, a limited impact on basal PDGFR-β expression and signaling and the antimigratory property of apoE on PDGF-BB–stimulated SMCs. Additionally, levels of LRP1 atherogenic ligands, like MMP2, t-PA, FVIII, and the inflammatory ligand TNF- showed to be significantly elevated.

Conclusion— These findings demonstrate that the NPxYxxL motif is essential for the atheroprotective role of LRP1. This motif is relevant for normal control of lipid metabolism and of atherogenic and inflammatory ligands, but has no pronounced effect on regulating PDGF-BB/PDGFR-β signaling in SMCs.

Methods and Results— Six-month-old apolipoprotein E–deficient mice were chronically infused with angiotensin II (1.44 mg/kg/d) for 4 weeks to induce abdominal aortic aneurysm (AAA), accelerate atherosclerosis development and carotid artery ligation-induced vascular remodeling. The mice were treated with a novel s-EH inhibitor, AR9276 (1.5 g/L in drinking water) or vehicle for 4 weeks. The results demonstrated that AR9276 significantly reduced the rate of AAA formation and atherosclerotic lesion area, but had no effect on ligation-induced carotid artery remodeling. These effects were associated with a reduction of serum lipid, IL-6, murine IL-8-KC, and IL-1, and downregulation of gene expressions of ICAM-1, VCAM-1, and IL-6 in the arterial wall.

Conclusions— The present data demonstrate that treatment with an s-EH inhibitor attenuates AAA formation and atherosclerosis development. The attendant downregulation of inflammatory mediators and lipid lowering effects may both contribute to the observed vascular protective effects.

Methods and Results— The first carotid artery was crush-injured and harvested after 30 minutes. Pigs then received intravenous lovastatin (100 µg/kg bolus+100 µg/kg/h infusion, n=6) or saline (n=11) before injury of the second carotid artery. Thrombus size was quantified by scintillation detection of autologous ¹¹¹In-platelets. Sequential carotid injury produced a thrombus more than 50% greater in volume in the second (3149±2053x10⁶/cm²) relative to the first injured artery (2081±1552x10⁶/cm²; P=0.04) in control pigs. This augmentation was inhibited by intravenous lovastatin which acutely reduced platelet deposition (944±246x10⁶/cm²) relative to saline control (P=0.02). Flow chamber closure times increased on average by 2.45-fold in response to whole blood lovastatin incubation. Lovastatin (P<0.05) and simvastatin (P<0.05) reduced platelet dense granule secretion in vitro.

Conclusions— Sequential arterial injury augments the thrombotic response suggesting that the propensity for arterial thrombosis is at least partially acquired. This thrombotic augmentation can be acutely attenuated by intravenous lovastatin which may result from a pleiotropic impact on platelet function. These results appear to be a class effect of 3-hydroxy-3-methyl-glutaryl-CoA reductase inhibitors.

Methods and Results— We examined the impact of renal dysfunction on macrophage cholesterol homeostasis in the apoE^–/– mouse model of atherosclerosis. Renal impairment induced by uninephrectomy dramatically increased macrophage cholesterol content, linked to striking impairment of macrophage cholesterol efflux. This blunted efflux was associated with downregulation of the cholesterol transporter ATP-binding cassette transporter A1 (ABCA1) and activation of the nuclear factor-kappa B (NF-B). Treatment with the angiotensin receptor blocker (ARB) losartan decreased NF-B and restored cholesterol efflux.

Conclusions— Our findings show that mild renal dysfunction perturbs macrophage lipid homeostasis by inhibiting cholesterol efflux, mediated by decreased ABCA1 transporter and activation of NF-B, and that ARB can restore cholesterol efflux.

Methods and Results— OxLDL-induced macrophage survival required glucose metabolism. OxLDL stimulated 2 phases of glucose uptake, namely acute and chronic, which required PI3K but not MEK1/2 activity. PI3K appeared to regulate glucose transport via glucose transporter affinity and/or mobilization. OxLDL also maintained levels of the prosurvival proteins, Bcl-2 and Bcl-x_L, after CSF-1 had been removed through a combination of mechanisms including transcription, translation, and protein stabilization. Significantly, inhibition of glucose metabolism reduced Bcl-2 and Bcl-x_L protein levels. MEK1/2 and PI3K activities were also required for oxLDL-induced Bcl-2 and Bcl-x_L mRNA upregulation.

Conclusions— These results suggest that oxLDL enhances macrophage survival in the absence of CSF-1 by inducing PI3K-dependent glucose uptake, which is metabolized to maintain Bcl-2 and Bcl-x_L protein levels.

Methods and Results— Methyl-β-cyclodextrin (MβCD) removed up to 73% and 45% of membrane cholesterol from HL-60 cells and neutrophils, whereas MβCD/cholesterol complexes resulted in maximum enrichment of 65% and 40%, respectively, above control levels. Cells were perfused at a venous wall shear rate of 100 s^–1 over adherent P-selectin–coated 1-µm diameter beads, uncoated 10-µm diameter beads, P-selectin–coated surfaces, or activated endothelium. Elevated cholesterol enhanced capture efficiency to 1-µm beads and increased membrane tether growth rate by 1.5- to 2-fold, whereas cholesterol depletion greatly reduced tether formation. Elevated cholesterol levels increased tether lifetime by 17% in neutrophils and adhesion lifetime by 63% in HL-60 cells. Deformation of cholesterol-enriched neutrophils increased the contact time with 10-µm beads by 32% and the contact area by 7-fold. On both P-selectin surfaces and endothelial-cell monolayers, cholesterol-enriched neutrophils rolled more slowly, more stably, and were more likely to firmly arrest. Cholesterol depletion resulted in opposite effects.

Conclusions— Increasing membrane cholesterol enhanced membrane tether formation and whole cell deformability, contributing to slower, more stable rolling on P-selectin and increased firm arrest on activated endothelium.

Methods and Results— We used SAA and SR-BI adenoviral vector expression models to study the interaction between these entities. SR-BI processing of mouse AP HDL generated progressively smaller discreet HDL particles with distinct apolipoprotein compositions. SR-BI actions segregated apolipoproteins with the smallest particles containing only apoA-I. Larger remnants contained apoA-I, apoA-II, and SAA. Small apoA-I only particles failed to associate with preformed HDL, whereas larger remnants readily did. The presence of SAA on SR-BI-processed HDL particles propelled apoA-I to a small lipid-poor form and accelerated apoA-I catabolism.

Conclusions— Data indicate that after core and surface HDL lipid perturbation by SR-BI, SAA propels apoA-I to a small lipid-poor form while accelerating HDL metabolism.

Methods and Results— We used a Markov model to compare the vitamin E supplemented virtual cohorts with nonsupplemented cohorts derived from published randomized clinical trials that were included in at least one of the major meta-analyses. The difference between the virtual supplemented and nonsupplemented cohorts is given in terms of a composite end point denoted quality-adjusted life year (QALY). The vitamin E supplemented virtual cohort had 0.30 QALY (95%CI 0.21 to 0.39) less than the nontreated virtual cohort.

Conclusions— Our study demonstrates that in terms of QALY, indiscriminate supplementation of high doses of vitamin E is not beneficial in preventing CVD. Selective supplementation of vitamin E to individuals under oxidative stress requires further investigation.

Methods and Results— 49 tagging and candidate polymorphisms in 9 genes were genotyped in 1507 post-ACS subjects randomized to atorvastatin or pravastatin. Two polymorphisms (rs7412, rs429358) that define the 2, 3, and 4 isoforms of apolipoprotein E were significantly associated with percent reduction in LDL-C with atorvastatin (2 carriers 53.8%, 3/3 48.1%, and 4 carriers 46.4%, respectively, P=0.00039) and replicated in the pravastatin arm (2 carriers 22.1%, 3/3 21.8%, and 4 carriers 16.6%, respectively, P=0.00038). The proportion of subjects achieving an LDL-C ≤70 mg/dL at day 30 was higher for 2 than 4 carriers (P=1.3x10^–5). In the pravastatin group, the triallelic rs2032582 variant (G2677T/A) in ABCB1 was associated with the percent reduction in LDL-C (GG 23.3%, non-G heterozygote 20.3%, and non-G homozygote 17.4%, P=0.042).

Conclusion— Carriers of APOE 2 versus 4 had significantly greater LDL-C reduction with atorvastatin and with pravastatin, and more frequently achieved a guideline-recommended LDL-C ≤70 mg/dL. Polymorphisms in triallelic G2677T/A variant in ABCB1 were associated with the degree of LDL-C lowering with pravastatin.

Methods and Results— Twelve common (minor allele frequency ≥0.1) single nucleotide polymorphisms in LRP6 were genotyped in 703 individuals from 213 Polish pedigrees (Silesian Cardiovascular Study families). The family-based analysis revealed that the minor allele of rs10845493 clustered with elevated LDL-C in offspring more frequently than expected by chance (P=0.0053). The quantitative analysis restricted to subjects free of lipid-lowering treatment confirmed the association between rs10845493 and age-, sex-, and BMI-adjusted circulating levels of LDL-C in families as well as 2 additional populations – 218 unrelated subjects from Silesian Cardiovascular Study replication panel and 1138 individuals from Young Men Cardiovascular Association cohort (P=0.0268, P=0.0476, and P=0.0472, respectively). In the inverse variance weighted meta-analysis of the 3 populations each extra minor allele copy of rs10845493 was associated with 0.14 mmol/L increase in age-, sex-, and BMI-adjusted LDL-C (SE=0.05, P=0.0038).

Conclusions— Common polymorphism in the gene underlying monogenic form of coronary artery disease impacts on risk of LDL-C elevation.

Methods and Results— In stage 1, 13 tag-SNPs were tested for association in Dutch samples ascertained for familial combined hyperlipidemia (FCHL) or increased risk for CVD (CVR). In stage 2, we further investigated the SNP with the strongest association from stage 1, a Methionine/Valine substitution at amino-acid 67, in Finnish FCHL families and in subjects with CVR from METSIM, a Finnish population-based cohort. The combined analysis of both stages reached region-wide significance (P=9x10^–4), but this association was not seen in the entire METSIM cohort. Our functional analysis demonstrated that Valine at position 67 augments ATF6 protein and its targets Grp78 and Grp94 as well as increases luciferase expression through Grp78 promoter.

Conclusions— A common nonsynonymous variant in ATF6 increases ATF6 protein levels and is associated with cholesterol levels in subjects at increased risk for CVD, but this association was not seen in a population-based cohort. Further replication is needed to confirm the role of this variant in lipids.

Methods and Results— The gene expression of scavenger receptors including scavenger receptor-A (SRA), CD36, and lectin-like oxidized LDL receptor-1 (LOX-1) were studied in subcutaneous adipose tissue of nondiabetic subjects and in vitro. Adipose tissue SRA expression was independently associated with insulin resistance. Pioglitazone downregulated SRA gene expression in adipose tissue of subjects with impaired glucose tolerance and decreased LOX-1 mRNA in vitro. Macrophage LOX-1 expression was decreased when macrophages were cocultured with adipocytes or when exposed to adipocyte conditioned medium. Adding adiponectin neutralizing antibody resulted in a 2-fold increase in LOX-1 gene expression demonstrating that adiponectin regulates LOX-1 expression.

Conclusion— Adipose tissue scavenger receptors are strongly associated with insulin resistance. Pioglitazone and adiponectin regulate gene expression of SRA and LOX-1, and this may have clinical implications in arresting the untoward sequalae of insulin resistance and diabetes, including accelerated atherosclerosis.

Methods and Results— Twelve HIV-1 infected patients, with stably suppressed HIV-1 viral load using AZT/3TC/abacavir for ≥6 months, added NVP to their current antiretroviral regimen. Patients received a primed bolus infusion of the stable isotope L-[1-¹³C]-valine for 12 hours before, as well as 6 and 24 weeks after, the addition of NVP to study apolipoprotein A-I (apoA-I) kinetics. Absolute production rate (APR) and fractional catabolic rate (FCR) of apoA-I were calculated using SAAM-II modeling. Major HDLc-modulating enzymes were assessed. Plasma apoA-I and HDLc levels increased significantly after 24 weeks of treatment by, respectively, 13±4% (P=0.01) and 16±6% (P=0.015). Concomitantly, apoA-I production rate at 24 weeks increased by 17±7% (P=0.04). ApoA-I catabolism did not change. A modest increase of lecithin:cholesterol acyltransferase and cholesteryl ester transfer protein activity was observed.

Conclusions— NVP increases apoA-I production, which contributes to the HDLc increase after introduction of NVP-containing regimens. In view of the potent antiatherogenic effects of apoA-I, the observed increase may contribute to the favorable cardiovascular profile of NVP.

Methods and Results— Iliac arteries were taken from 24 male Ossabaw pigs divided into lean control and metabolic syndrome groups and were imaged by multimodal NLO microscopy where sum-frequency generation (SFG) and 2-photon excitation fluorescence (TPEF) were integrated on a coherent anti-Stokes Raman scattering (CARS) microscope platform. Foam cells, lipid deposits, matrices, and fibrous caps were visualized with submicron 3D resolution. Starting from the adaptive intimal thickening in the initial stage to the fibrous atheroma or mineralization in the advanced stages, lesions were visualized without labels. Histological staining of each lesion confirmed the lesion stages. Lipid and collagen contents were quantitatively analyzed based on the CARS and SFG signals. Lipid accumulation in thickened intima culminated in type IV whereas the highest collagen deposition was found in Type V lesions. Luminal CARS imaging showed the capability of viewing the location of superficial foam cells that indicate relatively active locus in a lesion artery.

Conclusions— We have demonstrated the capability of CARS-based multimodal NLO microscopy to interrogate different stages of lesion development with subcellular detail to permit quantitative analysis of lipid and collagen contents.

Methods and Results— Mice deficient in both PEMT and low-density lipoprotein receptors (Pemt^–/–/Ldlr^–/– mice) were fed a high-fat/high-cholesterol diet for 16 weeks. Atherosclerotic lesion area was 80% lower (P<0.01) in Pemt^–/–/Ldlr^–/– mice than in Pemt^+/+/Ldlr^–/– mice, consistent with the atheroprotective plasma lipoprotein profile (ie, significant reduction in very low–density lipoprotein [VLDL]/intermediate-density lipoprotein/low-density lipoprotein–associated phospholipids [45%], triacylglycerols [65%], cholesterol [58%], and cholesteryl esters [68%]). Plasma apoB was decreased by 40% to 60%, whereas high-density lipoprotein levels were not altered. In addition, PEMT deficiency reduced plasma homocysteine by 34% to 52% in Pemt^–/–/Ldlr^–/– mice. The molar ratio of PC/phosphatidylethanolamine in nascent VLDLs produced by Pemt^–/–/Ldlr^–/– mice was lower than in VLDLs in Pemt^+/+/Ldlr^–/– mice. Furthermore, deletion of PEMT modestly reduced hepatic VLDL secretion in Ldlr^–/– mice and altered the rate of VLDL clearance from plasma.

Conclusion— This is the first report showing that inhibition of hepatic phospholipid biosynthesis attenuates atherosclerosis.

Methods and Results— Syndecan-1–null mice developed a large neointimal lesion after injury, whereas wild-type mice made little or none. This was accompanied by a significant increase in both medial and intimal SMC replication. Cultured syndecan-1–null SMCs showed a significant increase in proliferation in response to PDGF-BB, thrombin, FGF2, EGF, and serum. In response to thrombin, PDGF-BB, and serum syndecan-1–null SMCs expressed more PDGF-B chain message than did wild-type SMCs. Downregulation of PDGF-BB or PDGFRβ inhibited thrombin-, PDGF-BB–, and serum-induced DNA synthesis in syndecan-1–null SMCs.

Conclusions— These results suggest the possibility that syndecan-1 may limit intimal thickening in injured arteries by suppressing SMC activation through inhibition of SMC PDGF-B chain expression and PDGFRβ activation.

Methods and Results— Human cell cultures were treated with various cytokines, and PHD expression was examined using qRT-PCR and immunoblotting. IFN and, to a lesser extent, IFN significantly induced PHD3, but not PHD1 or 2, mRNA, and protein expression selectively in ECs directly via a JAK/STAT1 pathway as demonstrated by pharmacological inhibition, siRNA knockdown, and chromatin immunoprecipitation. Inhibition of PHD activity with dimethyloxallyl glycine or desferroxamine reduced IFNg-dependent responses in these same cells.

Conclusions— IFN induces PHD3 through a JAK/STAT1-dependent mechanism in human ECs. Induction is independent of HIF-1 and may contribute to expression of IFN-dependent genes.

Methods and Results— After incubation of human endothelial cells with palmitate at a concentration known to induce cellular inflammation (100 µmol/L), we measured superoxide levels by using electron spin resonance spectroscopy and the spin trap 1-hydroxy-3-methoxycarbonyl-2,2,5,5-tetramethylpyrrolidine (CMH). Palmitate exposure induced a >2-fold increase in superoxide levels, an effect associated with activation of NF-B signaling as measured by phospho-IB, NF-B activity, IL-6, and ICAM expression. Reduction in superoxide levels by each of 3 different interventions—pretreatment with superoxide dismutase (SOD), diphenylene iodinium (DPI), or knockdown of NADPH oxidase 4 (NOX4) by siRNA—attenuated palmitate-mediated NF-B signaling. Inhibition of toll like receptor-4 (TLR4) signaling also suppressed palmitate-mediated superoxide production and associated inflammation, whereas palmitate-mediated superoxide production was not affected by overexpression of a phosphorylation mutant IB (NF-B super repressor) that blocks cellular inflammation downstream of IKKβ/NF-B. Finally, high-fat feeding increased expression of NOX4 and an upstream activator, bone morphogenic protein (BMP4), in thoracic aortic tissue from C57BL/6 mice, but not in TLR4^–/– mice, compared to low-fat fed controls.

Conclusions— These results suggest that NADPH oxidase–dependent superoxide production links palmitate-stimulated TLR4 activation to NF-B signaling in endothelial cells.

Method and Results— PKD2 is the predominant isoform of PKD expressed in monocytic THP-1 cells and primary human monocytes. Lysophosphatidylcholine (lysoPC), a prominent component of oxidized low-density lipoprotein, induces rapid and marked PKD activation in these cells. Using multiple approaches, including dominant-negative mutants and small interfering RNA knock-down, we found that lysoPC-induced PKD2 activation was required for the activation of both ERK and p38 MAPK. p38 MAPK mediation of lysoPC-induced monocytic cell migration was reported previously; our results reveal that the lysoPC-induced PKD2-p38 pathway controls monocyte migration.

Conclusions— This study provides the first evidence that (1) lysoPC activates PKD, (2) PKD2 has a novel role in p38 activation, and (3) the PKD2-activated p38 pathway is responsible for lysoPC-induced migration of THP-1 cells and human monocytes. Thus, PKD is a novel and functional intracellular regulator in both lysoPC signaling and monocyte migration. These results suggest a new role for PKD2 in the development of atherosclerosis and other inflammatory diseases.

Methods and Results— Plasma was isolated from 1011 consecutive consenting subjects undergoing elective diagnostic cardiac catheterization, and future major adverse cardiac events (MACE, including myocardial infarction, stroke, and death) at 3 years were investigated. Plasma levels of asymmetrical dimethylarginine (ADMA, endogenous nitric oxide synthase [NOS] inhibitor), symmetrical dimethylarginine (SDMA, which lacks NOS inhibitory activity), N-mono-methylarginine (MMA, a potent NOS inhibitor), methyl-lysine (Methyl-Lys, an unrelated methylated amino acid), arginine, and its major catabolites (citrulline and ornithine) were quantified simultaneously by stable isotope dilution HPLC with online electrospray ionization tandem mass spectrometry and adjusted for traditional risk factors, C-reactive protein, and estimated creatinine clearance. High SDMA levels (adjusted odds ratio [OR] 1.6, 95%CI, 1.1 to 2.6, P<0.001), low MMA (adjusted OR 0.5, 95%CI 0.4 to 0.8, P=0.007), but not ADMA (adjusted OR 1.3, 95%CI 0.88 to 2.0, P=0.177) were associated with increased prevalence of significantly obstructive CAD. Elevated levels of SDMA (adjusted Hazard Ratio [HR] 2.4, 95%CI 1.2 to 4.6, P=0.009), ADMA (adjusted HR 2.2, 95%CI 1.2 to 4.0, P=0.015), as well as an integrated index of arginine methylation [ArgMI=(ADMA+SDMA)/MMA] (adjusted HR 2.4, 95%CI 1.3 to 4.5, P=0.006) were significant independent predictors of incident MACE. ArgMI was predictive of incident MACE even following adjustments for global arginine bioavailability, particularly within secondary prevention patients.

Conclusions— ADMA, SDMA, and the integrated quantification of arginine methylation (in the form of a methylation index) provided independent risk prediction for both significantly obstructive CAD and incident MACE in stable patients undergoing cardiac evaluation. These results suggest that factors beyond direct NOS inhibition contribute to the clinical associations between methylarginines and CAD outcomes.

Methods and Results— In the 195 young healthy women of the Atherosclerosis Risk Factors in Female Youngsters (ARFY) study, cadmium (Cd) level was independently associated with early atherosclerotic vessel wall thickening (intima-media thickness exceeding the 90th percentile of the distribution; multivariable OR 1.6[1.1.–2.3], P=0.016). In line, Cd-fed ApoE knockout mice yielded a significantly increased aortic plaque surface compared to controls (9.5 versus 26.0 mm², P<0.004). In vitro results indicate that physiological doses of Cd increase vascular endothelial permeability up to 6-fold by (1) inhibition of endothelial cell proliferation, and (2) induction of a caspase-independent but Bcl-xL-inhibitable form of cell death more than 72 hours after Cd addition. Both phenomena are preceded by Cd-induced DNA strand breaks and a cellular DNA damage response. Zinc showed a potent protective effect against deleterious effects of Cd both in the in vitro and human studies.

Conclusion— Our research suggests Cd has promoting effects on early human and murine atherosclerosis, which were partly offset by high Zn concentrations.

Methods and Results— Using Rochester Epidemiology Project resources, we identified all Olmsted County, Minn residents who met objective criteria for incident VTE over the 25-year period, 1976 to 2000 (n=1922), and 1 to 2 resident controls per case, matched on age, gender, and length of medical history (n=2115). Complete medical histories in the community were reviewed for previously identified independent VTE risk factors and diabetes-related variables. We tested diabetes and diabetes complications (retinopathy, nephropathy or neuropathy, and ketoacidosis) as potential VTE risk factors, both alone and after adjusting for VTE risk factors. Univariately, diabetes by clinical diagnosis or by stricter criteria (fasting ambulatory blood glucose ≥140 mg/dL or antidiabetic drug therapy), and diabetes complications, were associated with overall incident VTE. However, after controlling for hospitalization for major surgery or medical illness and nursing home confinement, diabetes was no longer associated with VTE.

Conclusion— Diabetes mellitus and diabetes complications are not independent risk factors for incident VTE.