Mitochondrial fission protein, dynamin-related protein 1, contributes to the promotion of hypertensive cardiac hypertrophy and fibrosis in Dahl-salt sensitive rats

Abstract Background Hypertension promotes cardiac hypertrophy which finally leads to cardiac dysfunction. Although aberrant mitochondrial dynamics is known to be a relevant contributor of pathogenesis in heart disease, little is known about the relationship between mitochondrial dynamics and cardiac hypertrophy. We investigated the pathophysiological roles of Dynamin-related protein1 (Drp1, a mitochondrial fission protein) on the hypertensive cardiac hypertrophy. Methods & results Dahl salt-sensitive rats were fed with a low-salt (0.3% NaCl) or a high-salt (8% NaCl) chow to promote hypertension with and without administration of mdivi1 (an inhibitor of Drp1: 1 mg/kg/every alternative day), and then the hypertensive cardiac hypertrophy was assessed. High-salt fed rats exhibited left ventricular hypertrophy (LVH), myocytes hypertrophy, and cardiac fibrosis, and mdivi-1 suppressed them without alteration of the blood pressure. Mdivi1 also reduced ROS production by hypertension, which subsequently suppressed the Ca 2+ -activated protein phosphatase calcineurin and Ca 2+ /calmodulin-dependent kinase II (CaMKII). Conclusions Our results suggest that Drp1 contributes to the pathogenesis of hypertensive cardiac hypertrophy via ROS production and the Drp1 suppression may be effective to prevent the hypertensive cardiac hypertrophy.