The Effects Of Lnc RNA-SRA On The Proliferation Of Vascular Smooth Muscle Cells And Its Mechanism

Objective: Vascular smooth muscle cells play an important role in the process of atherosclerosis and restenosis.It is thought that the process of restenosis is a process of neointimal hyperplasia and vascular remodeling,and the therapeutic intervention to inhibit the proliferation of vascular smooth muscle cells is beneficial to prevent neointimal hyperplasia and restenosis.Studies have been made that long non-coding RNA(lncRNA)-SRA promotes cell proliferation,differentiation and apoptosis by long non-coding RNA-SRA transgenic mice with BrDU immunohistochemistry,but its effect on vascular smooth muscle cell proliferation has not yet been reported.Therefore,the aim of this study was to investigate the effect of lncRNA-SRA on the proliferation and migration of vascular smooth muscle cells,to explore possible molecular mechanisms and related signal transduction pathways and to investigate new target for the prevention of neointima hyperplasia and restenosis.Method:1.C57BL/6 mice underwent right femoral artery guide wire injury.Hematoxylineosin staining(HE)was used to observe and evaluate the morphological changes of endometrium.2.The lncRNA-SRA adenovirus was injected into the tail vein after the femoral artery injury in C57BL/6 mice,and the expression of ki67 was detected by immunohistochemistry.3.Construction of lentiviral vector overexpressing lncRNA-SRA vascular smooth muscle cells,MTS and EdU were used to detect cell proliferation.Western blot was used to detect the proliferation marker gene.4.The effect of lncRNA-SRA on MEK-ERK-CREB signaling pathway was detected by Western blot.Results:1.The morphological analysis of vascular endothelium induced by guide wire injury showed that the elastic membrane disappeared,the VSMC of the medial membrane was disordered after 14 days of intimal injury,the diffuse thickening of the intima and the lumen gradually narrowed.Injured induction of mouse endometrial hyperplasia model was successfully constructed.2.Overexpression of lncRNA-SRA promotes the proliferation of vascular intima and the expression of proliferating markers after the femoral artery injury.The results of HE staining showed that the degree of hyperplasia(±)of overexpressing SRA(pAd-SRA)was significantly higher than that pAd group(* p <0.05).IHC results showed that the expression of Ki67 in the vascular tissue of the injured group with overexpression of SRA was significantly up-regulated.3.Overexpression of lncRNA-SRA promotes the proliferation and migration of vascular smooth muscle cells.At the same time,the protein levels of PCNA and CyclinD1 in vascular smooth muscle cells were significantly up-regulated.4.Overexpression of lncRNA-SRA promoted the expression of P-MEK1/2,P-ERK1/2,P-CREB,and the expression of P-MEK1/2,P-ERK1/2 and P-CREB were down-regulated under the influence of U0126(inhibitor of MEK1/2).U0126 reversed the effect of lncRNA-SRA on the proliferation of vascular smooth muscle cells.Our results suggest that lncRNA-SRA promotes the proliferation and migration of vascular smooth muscle cells by up-regulating MEK1/2 phosphorylation,suggesting that lncRNA-SRA may promote the occurrence and development of restenosis after vascular intervention via MEK-ERK-CREB signaling pathway.Conclusions:1.LncRNA-SRA overexpression promotes balloon injury-induced intimal hyperplasia.2.LncRNA-SRA promotes vascular endothelial cell proliferation throughMEK/ERK/CREB signaling pathway,and then activates proliferation-related gene expression.