High mobility group box-1 release from H2O2-injured hepatocytes due to sirt1 functional inhibition
| Autor: | Xiao-Feng Yan, Yan-Lin Lu, Ting-Jie Ye, Xu-Dong Hu, Xiao-Ling Wang |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
Male
Cytoplasm Poly (ADP-Ribose) Polymerase-1 Nicotinamide adenine dinucleotide medicine.disease_cause chemistry.chemical_compound Mice 0302 clinical medicine PARP1 Liver Function Tests Sirtuin 1 Gene expression High mobility group box-1 HMGB1 Protein RNA Small Interfering Cells Cultured biology medicine.diagnostic_test Quinolinium Compounds Gastroenterology Acetylation General Medicine Basic Study Poly ADP-ribose polymerase 1 Liver 030220 oncology & carcinogenesis 030211 gastroenterology & hepatology Carbazoles chemical and pharmacologic phenomena Diet High-Fat Cell Line 03 medical and health sciences Western blot Lactate dehydrogenase medicine Animals Humans Sirtuin1 Cell Nucleus Ethanol Hydrogen Peroxide Molecular biology Fatty Liver Disease Models Animal Oxidative Stress chemistry biology.protein Hepatocytes NAD+ kinase Oxidative stress |
| Zdroj: | World Journal of Gastroenterology |
| ISSN: | 2219-2840 1007-9327 |
| Popis: | Background High mobility group box-1 (HMGB1), recognized as a representative of damage-associated molecular patterns, is released during cell injury/death, triggering the inflammatory response and ultimately resulting in tissue damage. Dozens of studies have shown that HMGB1 is involved in certain diseases, but the details on how injured hepatocytes release HMGB1 need to be elicited. Aim To reveal HMGB1 release mechanism in hepatocytes undergoing oxidative stress. Methods C57BL6/J male mice were fed a high-fat diet for 12 wk plus a single binge of ethanol to induce severe steatohepatitis. Hepatocytes treated with H2O2 were used to establish an in vitro model. Serum alanine aminotransferase, liver H2O2 content and catalase activity, lactate dehydrogenase and 8-hydroxy-2-deoxyguanosine content, nicotinamide adenine dinucleotide (NAD+) levels, and Sirtuin 1 (Sirt1) activity were detected by spectrophotometry. HMGB1 release was measured by enzyme linked immunosorbent assay. HMGB1 translocation was observed by immunohistochemistry/immunofluorescence or Western blot. Relative mRNA levels were assayed by qPCR and protein expression was detected by Western blot. Acetylated HMGB1 and poly(ADP-ribose)polymerase 1 (Parp1) were analyzed by Immunoprecipitation. Results When hepatocytes were damaged, HMGB1 translocated from the nucleus to the cytoplasm because of its hyperacetylation and was passively released outside both in vivo and in vitro. After treatment with Sirt1-siRNA or Sirt1 inhibitor (EX527), the hyperacetylated HMGB1 in hepatocytes increased, and Sirt1 activity inhibited by H2O2 could be reversed by Parp1 inhibitor (DIQ). Parp1 and Sirt1 are two NAD+-dependent enzymes which play major roles in the decision of a cell to live or die in the context of stress . We showed that NAD+ depletion attributed to Parp1 activation after DNA damage was caused by oxidative stress in hepatocytes and resulted in Sirt1 activity inhibition. On the contrary, Sirt1 suppressed Parp1 by negatively regulating its gene expression and deacetylation. Conclusion The functional inhibition between Parp1 and Sirt1 leads to HMGB1 hyperacetylation, which leads to its translocation from the nucleus to the cytoplasm and finally outside the cell. |
| Databáze: | OpenAIRE |
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