(2012) The role of AKT1 and autophagy in the protective effect of hydrogen sulphide against hepatic ischemia/reperfusion injury in mice, Autophagy, 8:6, 954-962, DOI: 10.4161/auto.19927 To link to this article: https://doi.org/10.4161/auto.19927 Do not distribute.The role of AKT1 and autophagy in the protective effect of hydrogen sulphide against hepatic ischemia/reperfusion injury in mice Keywords: hydrogen sulphide, liver, ischemia-reperfusion injury, autophagy, mouseAbbreviations: I/R, ischemia-reperfusion; H 2 S, hydrogen sulphide; A/R, anoxia/reoxygenation; NaHS, sodium hydrosulfide; GPT, glutamic-pyruvate transaminase/alanine aminotransferase; GOT1, glutamic-oxaloacetic transaminase 1, soluble/aspartate aminotransferase; TNF, tumor necrosis factor(-a); IL6, interleukin 6; PtdIns3K, phosphatidylinositol 3-kinase; LC3, microtubule-associated protein 1 light chain 3; 3MA, 3-methyladenine; TUNEL, TdT-mediated dUTP nick-end labeling;ELISA, enzyme-linked immunosorbent assayHydrogen sulphide (H 2 S) exerts a protective effect in hepatic ischemia-reperfusion (I/R) injury. However, the exact mechanism of H 2 S action remains largely unknown. This study was designed to investigate the role of the PtdIns3K-AKT1 pathways and autophagy in the protective effect of H 2 S against hepatic I/R injury. Primary cultured mouse hepatocytes and livers with or without NaHS (a donor of H 2 S) preconditioning were exposed to anoxia/reoxygenation (A/R) and I/R, respectively. In certain groups, they were also pretreated with LY294002 (AKT1-specific inhibitor), 3-methyladenine (3MA, autophagy inhibitor) or rapamycin (autophagy enhancer), alone or simultaneously. Cell viability, expression of P-AKT1, T-AKT1, LC3 and BECN1 were examined. The severity of liver injury was measured by the levels of serum aminotransferase and inflammatory cytokine, apoptosis and histological examination. GFP-LC3 redistribution and transmission electron microscopy were used to test the activity of autophagy. H 2 S preconditioning activated PtdIns3K-AKT1 signaling in hepatocytes. LY294002 could abolish the AKT1 activation and attenuate the protective effect of H 2 S on hepatocytes A/R and hepatic I/R injuries. H 2 S suppressed hepatic autophagy in vitro and in vivo. Further reducing autophagy by 3MA also diminished the protective effect of H 2 S, while rapamycin could reverse the autophagy inhibitory effect and enhance the protective effect of H 2 S against hepatocytes A/R and hepatic I/R injuries, consequently. Taken together, H 2 S protects against hepatocytic A/R and hepatic I/R injuries, at least in part, through AKT1 activation but not autophagy. An autophagy agonist could be applied to potentiate this hepatoprotective effect by reversing the autophagy inhibition of H 2 S.

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Cholangiocarcinoma (CCA) is a notoriously lethal tumor mostly due to the de novo or acquired resistance to traditional chemotherapy besides gemcitabine and, therefore, an increasing need for effective strategies to prevent and treat the poor prognosis of this tumor is required. Thymoquinone (TQ), a hopeful natural product derived from black cumin (Nigella sativa) has shown considerable antineoplastic properties. Whether TQ exerts antitumor effects on CCA cells in vitro and in vivo remains unknown. Examinations of cell viability assay, detection of cell cycle and apoptosis, electrophoretic mobility shift assay (EMSA), western blotting and immunohistochemistry were used in the present study. We demonstrated that TQ inhibited the growth of human CCA cell lines (TFK-1 and HuCCT1) in a dose- and time-dependent manner. Firstly, our results provided evidence that TQ not only inhibits the proliferation of CCA cells, induces cell cycle arrest and prompts cell apoptotic effect in vitro, but it also exhibits inhibitory effects of tumor growth and angiogenesis in vivo. The responsible mechanism is at least partially due to TQ inhibiting the growth of CCA cell lines induced by downregulation of PI3K/Akt and NF-κB and regulated gene products, including p-AKT, p65, XIAP, Bcl-2, COX-2, VEGF. Taken together, these results provide strong evidence of our hypothesis that TQ alone presents a promising therapeutic regimen for the treatment of CCA cells with better efficiency.

HT exerts protective effects against hepatic I/R injury in mice, which might be associated with its anti-oxidative, anti-inflammatory, and anti-apoptotic properties. HT may be an effective hepatoprotective agent and a promising candidate for the treatment of liver I/R injury.

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