Melatonin prevents Drp1-mediated mitochondrial fission in diabetic hearts through SIRT1-PGC1α pathway

J Pineal Res. 2018 Sep;65(2):e12491. doi: 10.1111/jpi.12491. Epub 2018 Apr 14.

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-1α and inhibited Drp1-mediated mitochondrial fission and mitochondria-derived superoxide production. In contrast, SIRT1 or PGC-1α 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-1α-dependent manner. Moreover, chromatin immunoprecipitation analysis revealed that PGC-1α 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-PGC1α 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.

Keywords: Drp1; PGC-1α; diabetes; melatonin; mitochondrial fission; silent information regulator 1.

MeSH terms

  • Animals
  • Cell Line
  • Diabetes Mellitus, Experimental / drug therapy*
  • Diabetes Mellitus, Experimental / genetics
  • Diabetes Mellitus, Experimental / metabolism
  • Diabetes Mellitus, Experimental / pathology
  • Diabetic Cardiomyopathies / drug therapy*
  • Diabetic Cardiomyopathies / genetics
  • Diabetic Cardiomyopathies / metabolism
  • Diabetic Cardiomyopathies / pathology
  • Dynamins / genetics
  • Dynamins / metabolism*
  • Melatonin / pharmacokinetics*
  • Mice
  • Mice, Knockout
  • Mitochondria, Heart / genetics
  • Mitochondria, Heart / metabolism*
  • Mitochondria, Heart / pathology
  • Mitochondrial Dynamics / drug effects*
  • Mitochondrial Dynamics / genetics
  • Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha / genetics
  • Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha / metabolism*
  • Signal Transduction / drug effects*
  • Signal Transduction / genetics
  • Sirtuin 1 / genetics
  • Sirtuin 1 / metabolism*

Substances

  • Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha
  • Ppargc1a protein, mouse
  • Sirt1 protein, mouse
  • Sirtuin 1
  • Dnm1l protein, mouse
  • Dynamins
  • Melatonin