The Role Of Vasodilator Stimulated Phosphoprotein On Coronary Atherosclerosis And Possible Mechanism

BackgroudInflammation and endothelial dysfunction plays a central part in the pathogenesis of coronary atherosclerosis.In addition,the role of epicardial fat in coronary artery disease is also emphasized.VASP is an actin-binding protein which plays an important role in the regulation of cytoskeleton.AimTo investigate whether vasodilator stimulated phosphoprotein(VASP)is involved in resistin-related endothelial dysfunction and the phenotype conversion of epicardial adipocytes by regulating cytoskeletal polarity.Material and MethodsPart?Epicardial fat samples were taken from patients with valvular heart disease and non-coronary artery disease.Mature adipocytes identification was assessed using Oil Red O staining.F-actin staining in different conditions was examined with phalloidin.Gene expressions of UCP-1,PRDM 16 resistin and RIP140 in IL-6 at 100ng/ml and VASP-deficient adipocytes were determined by RT-PCR.Next,the expressions of proinflammatory cytokines IL-6,IL-8,TNF-? and MCP-1 were also determined by RT-PCR between LV-siVASP group and LV-sicntr group.Besides,the relative abundance of protein was assessed by Western blotting.Part?HCAECs transfected with control siRNA(LV-sicntr group)or VASP siRNA(LV-siVASP group),and VASP expressions in gene and protein levels were determined by quantitative RT-PCR and Western blotting.HCAECs were treated with different concentrations(0,10,20,50,100,200ng/mL)of resistin.Cell proliferation was evaluated by MTT assays.Cell migration was assessed by a Transwell chamber assay.Next,we observed the cell proliferation and migration between LV-sicntr group and LV-siVASP group in resistin at 100ng/ml.Last,immunofluorescent staining was used to analyze vascular endothelial growth factorreceptor 2 expression between LV-sicntr group and LV-siVASP group.ResultsPart?The epicardial adipocytes taken from patients with valvular heart disease and non-coronary artery disease had several lipid droplets of different sizes.The brown adipose tissue specific genes for UCP-1 and PRDM 16 decreased,but the white adipose tissue specific genes for resistin and RIP 140 increased in VASP-deficient adipocytes compared with LV-sicntr group.However,disruption of Ras homolog gene family,member A(RhoA)/Rho-associated kinase(ROCK)in VASP-deficient adipocytes with specific inhibitors could invert adipocyte phenotype existing in VASP-deficient adipocytes.Furthermore,the expressions of proinflammatory cytokines IL-6,IL-8,TNF-? and MCP-1 in VASP-deficient adipocytes were markedly upregulated compared with LV-sicntr group.Part?Resistin induced both endothelial proliferation and migration in a dose-dependent manner.Both resistin-induced cell proliferation and migration could be effectively blocked by ablation of VASP.The loss of VASP had no effect on expression on vascular endothelial growth factor receptor 2(VEGFR2)compared with LV-sicntr group.ConclusionsPart?VASP regulated phenotype conversion of epicardial adipocytes associated with inflammation.RhoA/ROCK activity was involved in VASP mediated phenotype conversion of EAT.Part?Resistin induces human coronary endothelial cells proliferation and migration,at least in part,by VASP protein.In conclusion,these results imply a physiological role for VASP in coronary atherosclerosis through regulating endothelial function and phenotype conversion of epicardiac adipose tissue by regulating cytoskeletal polarity.