Parkin Insufficiency Accentuates High-Fat Diet-Induced Cardiac Remodeling and Contractile Dysfunction Through VDAC1-Mediated Mitochondrial Ca Overload.

Mitochondrial Ca overload contributes to obesity cardiomyopathy, yet mechanisms that directly regulate it remain elusive. The authors investigated the role of Parkin on obesity-induced cardiac remodeling and dysfunction in human hearts and a mouse model of 24-week high-fat diet (HFD) feeding. Parkin knockout aggravated HFD-induced cardiac remodeling and dysfunction, mitochondrial Ca overload, and apoptosis without affecting global metabolism, blood pressure, and aortic stiffness. Parkin deficiency unmasked HFD-induced decline in voltage-dependent anion channel (VDAC) type 1 degradation through the ubiquitin-proteasome system but not other VDAC isoforms or mitochondrial Ca uniporter complex. These data suggest that Parkin-mediated proteolysis of VDAC type 1 is a promising therapeutic target for obesity cardiomyopathy.