Hepassocin (HPS), is a liver-specific gene with mitogenic activity on isolated hepatocytes. It is up-regulated following partial hepatectomy and down-regulated frequently in heptocellular carcinoma (HCC). However, very little is known about the HPS transcription regulation mechanism. In this study, we identified HNF1␣ (hepatocyte nuclear factor-1␣) as an important liver-specific cis-acting element for HPS using in vivo luciferase assays. Deletion of the HNF1 binding site not only led to a complete loss of HPS promoter activity in vivo but also abolished the induction of the HPS promoter by HNF1␣. An electrophoretic mobility shift assay demonstrated that HNF1␣ interacted with the HPS gene promoter in vitro. Chromatin immunoprecipitation showed that HNF1␣ interacted with HMGB1 and CREBbinding protein, and all of them were recruited to the HPS promoter in vivo. Moreover, HNF1␣ expression was lower in HCC cell lines and tissues and correlated significantly with the downregulation of HPS expression. Re-expression of HNF1␣ in human hepatoma HepG2 cells reinduced HPS expression. In contrast, knockdown of endogenous HNF1␣ expression by small interfering RNA resulted in a significant reduction of HPS expression. Furthermore, we found that partial hepatectomy and IL-6 significantly induced promoter activity of HPS, depending on STAT3 and HNF1 binding sites in the HPS promoter. These results demonstrate that the HNF1 binding site and HNF1␣ are critical to liver-specific expression of HPS, and down-regulation or loss of HNF1␣ causes, at least in part, the transcriptional down-regulation of HPS in HCC.
While melatonin is known to have protective effects in mitochondria-related diseases, aging, and neurodegenerative disorders, there is poor understanding of the effects of melatonin treatment on mitophagy in Alzheimer's disease (AD).We used proteomic analysis to investigate the effects and underlying molecular mechanisms of oral melatonin treatment on mitophagy in the hippocampus of 4-month-old wild-type mice versus age-matched 5 × FAD mice, an animal model of AD. 5 × FAD mice showed disordered mitophagy and mitochondrial dysfunction as revealed by increased mtDNA, mitochondrial marker proteins and MDA production, decreased electron transport chain proteins and ATP levels, and colocalization of Lamp1 and Tomm20. Melatonin treatment reversed the abnormal expression of proteins in the signaling pathway of lysosomes, pathologic phagocytosis of microglia, and mitochondrial energy metabolism. Moreover, melatonin restored mitophagy by improving mitophagosome-lysosome fusion via Mcoln1,
Two types of novel deep eutectic solvents with different functional groups were designed for highly efficient dissolution of different types of lignin.
The current study was aimed at evaluating the therapeutic implication of apigenin and to elucidate the underlying mechanism. The tert-butyl hydroperoxide (t-BHP) at 200 μM was used to induce oxidative stress-associated injury in ARPE-19 cells. Apigenin at concentrations less than 800 μM did not cause cytotoxic effects on ARPE-19 cells. Cell viability assay showed that apigenin at 200 μM significantly promoted cell survival in t-BHP-treated ARPE-19 cells. Additionally, apigenin at 100 μM significantly protected ARPE-19 cells from t-BHP-induced apoptosis. Molecular examinations demonstrated that apigenin at 400 μM significantly upregulated the mRNA and protein expression of Nrf2 and stimulated its nuclear translocation in ARPE-19 cells treated with or without t-BHP. Apigenin 400 μM also significantly elevated the expression of HO-1, NQO1, and GCLM at both mRNA and protein levels in the presence or absence of t-BHP. Furthermore, apigenin at 400 μM significantly increased the activities of SOD, CAT, GSH-PX, and T-AOC and reduced the levels of ROS and MDA in t-BHP-treated ARPE-19 cells. However, these effects of apigenin were all abolished by being transfected with Nrf2 siRNA. Collectively, our current data indicated that apigenin exerted potent antioxidant properties in ARPE-19 cells challenged with t-BHP, which were dependent on activation of Nrf2 signaling.
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