H(+)/Cl(‑) exchange transporter 7 promotes lysosomal acidification‑mediated autophagy in mouse cardiomyocytes

Area of Science:

• Cardiology
• Cell Biology
• Molecular Mechanisms

Background:

• Autophagy is vital for cardiomyocyte health, but its regulation is not fully understood.
• The specific role of chloride channel 7 (CLC-7) in cardiomyocyte autophagy requires further investigation.

Purpose of the Study:

• To investigate the function of H(+)/Cl(-) exchange transporter 7 (CLC-7) in regulating autophagy within mouse cardiomyocytes.
• To elucidate the molecular mechanisms by which CLC-7 influences autophagic clearance and cytoprotection.

Main Methods:

• Rapamycin was used to induce autophagy in mouse cardiomyocytes.
• CLC-7 expression and autophagy-related proteins (LC3, ATG5, Beclin-1) were analyzed via Western blotting and immunofluorescence.
• Transmission electron microscopy and siRNA-mediated CLC-7 knockdown were employed to assess autophagosome formation and lysosomal function.
• Cell viability and lysosomal acidification were measured using CCK-8, LDH assays, and specific indicators.

Main Results:

• Increased co-localization of CLC-7 with lysosomes was observed during induced autophagy.
• Knockdown of CLC-7 impaired lysosomal acidification, a critical step in autophagy.
• Disruption of lysosomal acidification by CLC-7 silencing led to impaired autophagy flux and subsequent cardiomyocyte injury.
• CLC-7 expression levels correlated with the efficiency of autophagic clearance.

Conclusions:

• Chloride channel 7 (CLC-7) plays a significant role in promoting cardiomyocyte autophagy.
• CLC-7 contributes to cytoprotection in cardiomyocytes by regulating lysosomal acidification and maintaining autophagy flux.
• These findings highlight CLC-7 as a potential therapeutic target for conditions involving impaired autophagy in the heart.