UCLA

Despite limited regenerative capacity as we age, cardiomyocytes maintain their function in part through compensatory mechanisms, e.g., Vinculin reinforcement of intercalated discs in aged organisms. This mechanism, which is conserved from flies to non-human primates, creates a more crystalline sarcomere lattice that extends lifespan, but systemic connections between the cardiac sarcomere structure and lifespan extension are not apparent. Using the rapidly aging fly system, we found that cardiac-specific Vinculin-overexpression [Vinculin heart-enhanced (VincHE)] increases heart contractility, maximal cardiac mitochondrial respiration, and organismal fitness with age. Systemic metabolism also dramatically changed with age and VincHE; steady state sugar concentrations, as well as aerobic glucose metabolism, increase in VincHE and suggest enhanced energy substrate utilization with increased cardiac performance. When cardiac stress was induced with the complex I inhibitor rotenone, VincHE hearts sustain contractions unlike controls. This work establishes a new link between the cardiac cytoskeleton and systemic glucose utilization and protects mitochondrial function from external stress.