Arteriosclerosis, thrombosis, and vascular biology
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Arterioscler. Thromb. Vasc. Biol. · Sep 2012
ReviewTargeting the consequences of the metabolic syndrome in the Diabetes Prevention Program.
This review describes the effect of lifestyle change or metformin compared with standard care on incident type 2 diabetes and cardiometabolic risk factors in the Diabetes Prevention Program and its Outcome Study. The Diabetes Prevention Program was a randomized controlled clinical trial of intensive lifestyle and metformin treatments versus standard care in 3234 subjects at high risk for type 2 diabetes. At baseline, hypertension was present in 28% of subjects, and 53% had metabolic syndrome with considerable variation in risk factors by age, sex, and race. ⋯ This was accompanied by significant improvement in cardiovascular disease risk factors over time in all treatment groups, in part associated with increasing use of lipid-lowering and antihypertensive medications. Thus a program of lifestyle change significantly reduced type 2 diabetes incidence and metabolic syndrome prevalence in subjects at high risk for type 2 diabetes. Metformin had more modest effects.
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Arterioscler. Thromb. Vasc. Biol. · Sep 2012
Vascular smooth muscle cell Smad4 gene is important for mouse vascular development.
Smad4 is a central mediator of transforming growth factor-β/bone morphogenetic protein signaling that controls numerous developmental processes as well as homeostasis in the adult. The present studies sought to understand the function of Smad4 expressed in vascular smooth muscle cells (VSMC) in vascular development and the underlying mechanisms. ⋯ SMC-specific deletion of Smad4 results in vascular defects that lead to embryonic lethality in mice, which may be attributed to decreased VSMC differentiation, proliferation, migration, as well as cell attachment and spreading. The transforming growth factor-β signaling pathway contributes to VSMC differentiation and function, whereas the bone morphogenetic protein signaling pathway regulates VSMC migration. These studies provide important insight into the role of Smad4 and its upstream Smads in regulating SMC function and vascular development of mice.
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Arterioscler. Thromb. Vasc. Biol. · Jul 2012
Proprotein convertase subtilisin/kexin type 9 interacts with apolipoprotein B and prevents its intracellular degradation, irrespective of the low-density lipoprotein receptor.
proprotein convertase subtilisin/kexin type 9 (PCSK9) negatively regulates the low-density lipoprotein (LDL) receptor (LDLR) in hepatocytes and therefore plays an important role in controlling circulating levels of LDL-cholesterol. To date, the relationship between PCSK9 and metabolism of apolipoprotein B (apoB), the structural protein of LDL, has been controversial and remains to be clarified. ⋯ We propose a new role for PCSK9 that involves shuttling between apoB and LDLR. The present study thus provides new insights into the action of PCSK9 in regulating apoB metabolism. Furthermore, our results indicate that targeting PCSK9 expression represents a new paradigm in therapeutic intervention against hyperlipidemia.
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Arterioscler. Thromb. Vasc. Biol. · Jun 2012
Synergistic effect of thrombin and CD40 ligand on endothelial matrix metalloproteinase-10 expression and microparticle generation in vitro and in vivo.
Thrombin induces CD40 ligand (CD40L) and matrix metalloproteinases (MMPs) under inflammatory/prothrombotic conditions. Thrombin and CD40L could modulate endothelial MMP-10 expression in vitro and in vivo. ⋯ Thrombin/CD40L elicited a strong synergistic effect on endothelial MMP-10 expression and microparticles containing MMP-10 in vitro and in vivo, which may represent a new link between inflammation/thrombosis with prognostic implications.
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Arterioscler. Thromb. Vasc. Biol. · Jun 2012
Comparative StudyRole of Src tyrosine kinases in experimental pulmonary hypertension.
Pulmonary arterial hypertension is a progressive pulmonary vascular disorder with high morbidity and mortality. Compelling evidence suggests that receptor tyrosine kinases, such as platelet-derived growth factor (PDGF) are closely involved in the pathogenesis of pulmonary arterial hypertension. We investigated the effects of 2 novel PDGF inhibitors, nilotinib/AMN107 (Abl kinases/PDGF receptor inhibitor) and dasatinib/BMS-354825 (Abl kinases/PDGF receptor/Src inhibitor), on the proliferation and migration of pulmonary arterial smooth muscle cells (PASMCs) and on the hemodynamics and pulmonary vascular remodeling in experimental pulmonary hypertension, and determined the expression and regulation of Src family kinases. ⋯ We suggest that dual inhibition of PDGF receptor and Src kinases potently inhibits mitogenic and motogenic responses to growth factors in PASMCs and pulmonary vascular remodeling in vivo so that dual inhibition may represent an alternative therapeutic approach for pulmonary arterial hypertension.