Lead-induced cardiomyocytes apoptosis by inhibiting gap junction intercellular communication via modulating the PKC?/Cx43 signaling pathway

Objective: The aim of this study was to investigate the regulatory mechanism of Pb regulates gap junction intercellular communication to induced apoptosis in H9c2 cells.Methods: H9c2 cell line is used as the research object in this study, and treated with different concentrations of Pb acetate. Subsequently, Cell viability was measured by the Cell Counting Kit-8 (CCK-8) assay. The levels of lactate dehydrogenase (LDH), aspartate transaminase (AST) and creatine kinase-MB (CK-MB) in the supernatants were measured using respective commercial enzyme-linked immune sorbent assay (ELISA) kits. Western blot was used to detect the expression of apoptosis-related protein in H9c2 cells in each group. Quantitative RT-PCR Analysis Total RNA was extracted from frozen H9c2 cells using Trizol reagent, the PKC alpha and Cx43 in the supernatant of H9c2 cells was determined by the BCA protein detection kit.Results: H9c2 cells increased release of cardiac enzymes (LDH, AST, and CK-MB) and decreased cell survival rate, and the Cx43, p-Cx43, PKC alpha and p-PKC alpha protein levels showed a dose-dependent decrease after Pb treatment. PKC alpha was activated with PMA, the relative expression level of Cx43 protein increased significantly, the expression of Bcl-2 increased and Bax and Cyt-c decreased compared with Pb exposure group, and the myocardial enzymes (LDH, AST, and CK-MB) in cell culture supernatant decreased compared with Pb exposure group, indicating that the degree of cell damage was alleviated. Results showed that Pb inhibited PKC alpha activity, decreased the expression of total Cx43 and P-Cx43 protein, and aggravated myocardial injury.Conclusions: Pb decrease gap junction intercellular communication, which induce apoptosis in H9c2 cells by inhibiting the PKC alpha/Cx43 signaling pathway.