An Experimental Study On The Effect Of SLC7A11 Expression And Regulation On Vascular Smooth Muscle Cell Phenotype Transition And Intimal Hyperplasia After Vascular Injury

BackgroundVascular restenosis is due to a phenotype transition(dedifferentiation)from contractile to secretory phenotype of vascular smooth muscle cells(VSMCs)after vascular injury,that is,from a low proliferative,migratory,and secretory phenotype to a high proliferative,migratory and secretory phenotype,accompanied by changes in intracellular metabolic levels and redox balance.Solute carrier family 7 member 11(SLC7A11)is an anti-transporter of cystine/glutamate on the cell membrane and plays an important role in maintaining intracellular redox balance.The expression level of SLC7A11 is closely related to cell proliferation,but the expression changes in VSMCs after vascular injury and its effect on VSMCs have not been reported yet.ObjectivesTo explore the expression changes of SLC7A11 after vascular injury and the effect of regulating SLC7A11 on the VSMCs phenotype transition and intimal hyperplasia.MethodsRat primary aortic smooth muscle cells(VSMCs)were cultured in vitro,and platelet-derived growth factor(PDGF)was used to induce VSMCs to dedifferentiate.The expression of SLC7A11 and its changes over time were detected by RT-qPCR and Western blot(WB).A rat carotid balloon injury model was constructed,the degree of intimal hyperplasia was observed by H&E staining,and the expression changes of SLC7A11 after vascular injury were detected by immunohistochemistry(IHC),immunofluorescence(IF)and WB.After knockdown and overexpression of SLC7A11,Edu was used to assess the proliferation level of VSMCs,transwell and cell scratch assays were used to compare the migration ability of VSMCs,and WB was used to detect the changes of phenotypic proteins of VSMCs.VSMCs were pretreated with different concentrations of erastin,and cell viability was detected by CCK-8.Edu was used to study the proliferation level of VSMCs.Transwell and cell scratch experiments were used to study the migration ability of VSMCs.WB was used to detect the level of phenotypic proteins.After balloon injury,different concentrations of erastin/F 127 gel were locally administered,and vascular tissue was harvested 14 days after injury to calculate the intima area and intima/media area ratio.IHC and WB were used to detect the proliferation proteins and phenotypic proteins of VSMCs.ResultsThe expression of SLC7A11 in secretory VSMCs was significantly increased,and the expression of SLC7A11 reached a peak on the 7th day after balloon injury,and was concentrated in the VSMCs of the thickened intimal layer.After inhibition of SLC7A11,the proliferative and migratory ability of VSMCs decreased,and the contractile phenotypic protein aSMA and SM22α increased,and secretory phenotypic protein Vimentin decreased.Compared with the control group,the intima area and intima/media ratio of the erastin administration group were significantly decreased,the expressions of contractile proteins aSMA and SM22α were up-regulated,and the expression of secretory phenotypic protein PCNA and KLF4 was down-regulated.ConclusionsSLC7A11 regulates the proliferation,migration ability and phenotype transition of VSMCs,and inhibiting the expression of SLC7A11 can reduce intimal hyperplasia by inhibiting the proliferation of VSMCs and promoting the transition of VSMCs to contractile phenotype.