Apoptosis Repressor With Caspase Recruitment Domain(ARC)promotes Vascular Smooth Muscle Cell Proliferation And Phenotypic Modulation Through 14-3-3?/YAP Signaling

Objective: Abnormal proliferation,migration and phenotype modulation of vascular smooth muscle cells(VSMCs)is the main basis of atherosclerosis.Therefore,the molecular mechanism of proliferation,migration and phenotype modulation of VSMC can provide new therapeutic targets for atherosclerosis.In response to vascular injury,VSMC may change from a contractile phenotype to a proliferative phenotype and consequently become conducive to neointima formation.Apoptosis repressor with caspase recruitment domain(ARC)was initially discovered as an endogenous apoptosis inhibitor,but whether ARC plays a role in VSMCs and whether it can participate in the regulation of atherosclerosis are unknown.Methods: Protein and m RNA levels of ARC in tissues and cells were detected by western blot and quantitative real-time PCR.Immunofluorescence staining was used to detect the protein location,and immunohistochemistry was used to detect protein expression in tissues.VSMC proliferation was analyzed using Cell Counting Kit-8(CCK-8)and Ed U assays,while migration was assessed by Transwell assay.Mechanistically,the direct binding between two proteins was verified by immunoprecipitation.Results: The results showed that ARC expression was stimulated in VSMCs during cell proliferation.Our results also showed that ARC promoted cell proliferation and induced phenotypic modulation of VSMCs.Mechanistic studies demonstrated that ARC increased the nuclear localization of Yes associated protein(YAP)by binding to 14-3-3? and that ARC played a role in promoting cell proliferation and phenotypic modulation.Additionally,the transcription factor p53 negatively regulated ARC expression at the transcriptional level during cell proliferation and phenotypic modulation.Conclusions: In this study,we focused on the function and underlying mechanism of ARC in VSMC phenotypic modulation.We have investigated the specific role of ARC in the regulation of YAP in VSMC phenotype modulation.Furthermore,we have also demonstrated that p53 negatively regulates the expression of ARC at the transcriptional level during cell proliferation,migration and phenotypic modulation.Our findings define a novel role for ARC in the phenotypic transition of proliferating VSMCs,which may provide a new strategy for regulating neointimal formation.