Melatonin prevents Drp1-mediated mitochondrial fission in diabetic hearts through SIRT1-PGC1? pathway.

ABSTRACT: Myocardial contractile dysfunction is associated with an increase in mitochondrial fission in patients with diabetes. However, whether mitochondrial fission directly promotes diabetes-induced cardiac dysfunction is still unknown. Melatonin exerts a substantial influence on the regulation of mitochondrial fission/fusion. This study investigated whether melatonin protects against diabetes-induced cardiac dysfunction via regulation of mitochondrial fission/fusion and explored its underlying mechanisms. Here, we show that melatonin prevented diabetes-induced cardiac dysfunction by inhibiting dynamin-related protein 1 (Drp1)-mediated mitochondrial fission. Melatonin treatment decreased Drp1 expression, inhibited mitochondrial fragmentation, suppressed oxidative stress, reduced cardiomyocyte apoptosis, improved mitochondrial function and cardiac function in streptozotocin (STZ)-induced diabetic mice, but not in SIRT1^-/- diabetic mice. In high glucose-exposed H9c2 cells, melatonin treatment increased the expression of SIRT1 and PGC-1? and inhibited Drp1-mediated mitochondrial fission and mitochondria-derived superoxide production. In contrast, SIRT1 or PGC-1? siRNA knockdown blunted the inhibitory effects of melatonin on Drp1 expression and mitochondrial fission. These data indicated that melatonin exerted its cardioprotective effects by reducing Drp1-mediated mitochondrial fission in a SIRT1/PGC-1?-dependent manner. Moreover, chromatin immunoprecipitation analysis revealed that PGC-1? directly regulated the expression of Drp1 by binding to its promoter. Inhibition of mitochondrial fission with Drp1 inhibitor mdivi-1 suppressed oxidative stress, alleviated mitochondrial dysfunction and cardiac dysfunction in diabetic mice. These findings show that melatonin attenuates the development of diabetes-induced cardiac dysfunction by preventing mitochondrial fission through SIRT1-PGC1? pathway, which negatively regulates the expression of Drp1 directly. Inhibition of mitochondrial fission may be a potential target for delaying cardiac complications in patients with diabetes.

SUBMITTER: Ding M 

PROVIDER: S-EPMC6099285 | biostudies-literature | 2018 Sep

REPOSITORIES: biostudies-literature