Melatonin alleviates post-infarction cardiac remodeling and dysfunction by inhibiting Mst1.
J Pineal Res. 2016 Oct 1. Epub 2016 Aug 1. PMID: 27696525
Melatonin reportedly protects against several cardiovascular diseases including ischemia/reperfusion (I/R), atherosclerosis and hypertension. The present study investigated the effects and mechanisms of melatonin on cardiomyocyte autophagy, apoptosis and mitochondrial injury in the context of MI. We demonstrated that melatonin significantly alleviated cardiac dysfunction after MI. Four weeks after MI, echocardiography and Masson staining indicated that melatonin notably mitigated adverse left ventricle remodeling. The mechanism may be associated with increased autophagy, reduced apoptosis and alleviated mitochondrial dysfunction. Furthermore, melatonin significantly inhibited Mst1 phosphorylation while promoting Sirt1 expression after MI, which indicates that Mst1/ Sirt1 signaling may serve as the downstream target of melatonin. We thus constructed a MI model using Mst1 transgenic (Mst1 Tg) and Mst1 knockout (Mst1(-/-) ) mice. The absence of Mst1 abolished the favorable effects of melatonin on cardiac injury after MI. Consistently, melatonin administration did not further increase autophagy, decrease apoptosis or alleviate mitochondrial integrity and biogenesis in Mst1 knockout mice subjected to MI injury. These results suggest that melatonin alleviates post-infarction cardiac remodeling and dysfunction by up-regulating autophagy, decreasing apoptosis and modulating mitochondrial integrity and biogenesis. The attributed mechanism involved, at least in part, Mst1/Sirt1 signaling. This article is protected by copyright. All rights reserved.