Background/Aims: Melatonin has been demonstrated to protect cardiac microvascular endothelial cells (CMECs) against ischemia/reperfusion injury (IRI). Autophagy plays different roles in the heart during ischemia and reperfusion. The AMP activated protein kinase/mammalian target of rapamycin (AMPK/mTOR) pathway is associated with autophagy. This study sought to explore whether melatonin regulates CMEC autophagy through the AMPK/mTOR signaling pathway. Methods: The effects of melatonin in IRI were investigated in vivo rat models and in vitro neonatal CMECs. Myocardial infarct size was achieved by Evans blue and triphenyltetrazolium chloride staining. The severity of cell injury was evaluated by cell vitality and lactate dehydrogenase (LDH) release assays, and autophagy was evaluated by transmission electron microscopy and the assessment of autophagy-related gene expression, such as that of Beclin 1 and light chain 3-II. Results: In vivo, melatonin markedly reduced infarcted area, improved cardiac function and decreased LDH release. However, the AMPK activator AICAR and the mTOR inhibitor rapamycin reduced the protective effects of melatonin on IRI. In vitro, Beclin1 and light chain 3-II protein were found to be down-regulated and autophagosomes were found to be reduced in response to melatonin, together with an increase in cell vitality and a decrease in LDH. Treatment with AICAR or rapamycin ablated the benefit observed with melatonin treatment. Conclusions: Melatonin played an important and protective role in CMECs by inhibiting autophagy against IRI via the AMPK/mTOR system.

An efficient and environment-friendly treatment for the preparation of EWP–TP conjugates.

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BackgroundOvarian cancer is the fifth leading cause of cancer deaths in women worldwide. LncRNACCAT1 was reported to play a critical role in cell metastasis of ovarian cancer. However, little is known about the detailed mechanism of how CCAT1 enhances TGFβ1-induced EMT of ovarian cancer cells.MethodsWe used RT-qPCR to examine the level of miR-490-3p and CCAT1 and western blot to detect the protein level of TGFβR1 and EMT-associated markers. We utilized luciferase reporter assay to confirm the direct interaction of CCAT1 or TGFβ1 with miR-490-3p. Wound healing and invasion assay were employed to investigate the role of CCAT1 and miR-490-3p in the TGFβ1-induced migration and cell invasion of ovarian cancer cells, respectively.ResultsTGFβ1 stimulated the expression of CCAT1. And CCAT1 knockdown decreased cell migration, invasion and EMT-associated markers expression of ovarian cancer cells treated with TGFβ1. CCAT1 directly targeted and downregulated miR-490-3p, then increasing TGFβR1 level. miR-490-3p was shown to regulate cell invasion, migration and EMT markers expression via TGFβR1. In addition, we also observed that miR-490-3p was essential for TGFβ1-induced tumor cell invasion and migration influenced by CCAT1. CCAT1 level was significantly higher in tumors than adjacent normal tissue, in contrast, miR-490-3p level was lower in ovarian tumors.ConclusionHere, we reveal that CCAT1 contributes to TGFβ1-induced EMT of ovarian tumor cells through miR-490-3p/TGFR1 axis. These findings will provide deep insights into the mechanism by which CCAT1 exerts its oncogenic role in ovarian cancer progression and facilitate developing novel therapeutical therapies for treating ovarian cancer.