Effects Of Cx43 On Proliferation And Apoptosis Of Cardiomyocytes Under High And Low Glucose

Objective: the purpose of this study was to observe the effects of high glucose and low glucose on cardiac fibroblasts and cardiac myocytes and to explore the role of Cx43 in this study.Methods:(1)high glucose experiment: cardiac fibroblasts were divided into control group(5.5mM,Con),high glucose group(33.3mM,HG),mannitol control group(Man),Cx43 overexpression group(HG+Cx43),inhibitor group(HG+Cx43+CBX).CCK-8 experiment,EdU experiment were used to detected cells proliferation;scratch test and Transwell assay were used to detected cells migration;to detect the expression of Cx43 protein,Western blot assay and immunofluorescence assay were used;Scrape-loading and dye transfer(SLDT)was used to detected the gap function.(2)low glucose experiment: H9c2 cells were divided into control group(5.5mM),high glucose group(33.3mM),low glucose group(2.5mM),mannitol control group(Man)and inhibitor group(3-MA).Cell viability was observed by MTT test,cytotoxicity was observed by LDH release assay,and expression of Cx43,autophagy and apoptosis related protein was detected by Western blot assay.Results:(1)high glucose leads to myocardial fibroblast proliferation,migration and the transcriptional level of fibrosis related genes(?-SMA,Collagen I)was significantly increased,the expression of Cx43 and the gap junction function were decline;overexpression of Cx43 can significantly reverse the situation,but CBX did not significantly change the phenomenon.(2)cells cultured in low glucose resulted in decreased H9c2 cell proliferation,increased cytotoxicity and apoptosis,reduced Cx43 expression and autophagy,while 3-MA inhibited autophagy activation(LC3 and Beclin-1 decreased),inhibited Cx43 degradation and reduced myocardial damage.Conclusion: High glucose culture promoted the activation of myocardial fibroblasts,while low glucose culture increased the apoptosis of cardiac myocytes.The decrease of Cx43 expression may be involved in the activation of cardiac fibroblasts under high glucose and promote the apoptosis of cardiomyocytes under low glucose.