SIRT1 Ameliorates Lamin A/C Deficiency-Induced Cardiac Dysfunction by Promoting Mitochondrial Bioenergetics.

Dilated cardiomyopathy (DCM) is associated with high mortality despite advanced therapies. The LMNA gene encodes lamin A/C and is the second most frequently mutated gene associated with DCM, for which therapeutic options are limited. Here we generated Lmna -/- mice and found they exhibited cardiac dysfunction at the age of 1 month but not at 2 weeks. Proteomics showed down-regulation of mitochondrial function-related pathways in Lmna -/- hearts. Moreover, early injured mitochondria with decreased cristae density and sirtuin 1 (SIRT1) down-regulation were observed in 2-week-old Lmna -/- hearts. Adenoviral overexpression of SIRT1 in lamin A/C knockdown neonatal rat ventricular myocytes improved mitochondrial oxidative respiration capacity. Adeno-associated virus-mediated SIRT1 overexpression alleviated mitochondrial injury, cardiac systolic dysfunction, ventricular dilation, and fibrosis, and prolonged lifespan in Lmna -/- mice. Mechanistically, LMNA maintains mitochondrial bioenergetics through the SIRT1-PARKIN axis. Our results suggest that targeting the SIRT1 signaling pathway is expected to be a novel therapeutic strategy for LMNA mutation-associated DCM.