RESUMO
Autophagy protects cardiomyocytes in various pathological and physiological conditions; however, the molecular mechanisms underlying its influence and the promotion of autophagic clearance are not completely understood. The present study aimed to explore the role of H(+)/Cl() exchange transporter 7 (CLC7) in cardiomyocyte autophagy. In this study, rapamycin was used to induce autophagy in mouse cardiomyocytes, and the changes in CLC7 were investigated. The expression levels of CLC7 and autophagyrelated proteins, such as microtubule associated protein 1 light chain 3, autophagy related 5 and Beclin 1, were detected using western blotting or immunofluorescence. Autolysosomes were observed and analyzed using transmission electron microscopy and immunofluorescence following CLC7 silencing with small interfering RNAs. Cellular viability was assessed using Cell Counting Kit8 and lactate dehydrogenase assays. Lysosomal acidification was measured using an acidification indicator. Increased CLC7 colocalization with lysosomes was identified during autophagy. CLC7 knockdown weakened the acidification of lysosomes, which are the terminal compartments of autophagy flux, and consequently impaired autophagy flux, ultimately resulting in cell injury. Collectively, the present study demonstrated that in cardiomyocytes, CLC7 may contribute to autophagy via regulation of lysosomal acidification. These findings provide novel insights into the role of CLC7 in autophagy and cytoprotection.