High mobility group box-1 release from H2O2-injured hepatocytes due to sirt1 functional inhibition
High mobility group box-1 release from H2O2-injured hepatocytes due to sirt1 functional inhibition
复制标题
由于sirt1功能抑制，H2O2损伤的肝细胞释放高迁移率族box-1
DOI：
10.3748/wjg.v25.i36.5434
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发表时间：
2019-09
影响因子：
4.3
通讯作者：
Wang Xiao-Ling
中科院分区：
文献类型：
--
作者：
Ye Ting-Jie;Lu Yan-Lin;Yan Xiao-Feng;Hu Xu-Dong;Wang Xiao-Ling
背景高迁移率族蛋白-1(HMGB1)被认为是损伤相关分子模式的代表，在细胞损伤/死亡过程中释放，触发炎症反应，最终导致组织损伤。数十项研究表明，HMGB1与某些疾病有关，但关于受损肝细胞如何释放HMGB1的细节还有待研究。目的揭示氧化应激下肝细胞释放HMGB1的机制。方法以C57BL6/J雄性小鼠为模型，高脂饲料喂养12wk，单次饮酒诱发重度脂肪性肝炎。用过氧化氢处理肝细胞建立体外模型。用分光光度法检测血清丙氨酸氨基转移酶、肝脏过氧化氢酶活性、乳酸脱氢酶和8-羟基-2-脱氧鸟苷含量、烟酰胺腺嘌呤二核苷酸(NAD+)含量和Sirt1活性。采用酶联免疫吸附试验检测HMGB1的释放。免疫组织化学/免疫荧光法或Western印迹法观察HMGB1易位。用定量聚合酶链式反应检测相对mRNA水平，用Western印迹法检测蛋白表达。用免疫沉淀法分析乙酰化HMGB1和聚腺苷二磷酸核糖聚合酶1(PARP1)。结果肝细胞损伤时，HMGB1因其高乙酰化作用从胞核移位至胞浆，在体内和体外均被被动释放。经Sirt1-siRNA或Sirt1抑制剂(EX527)处理后，肝细胞中高乙酰化的HMGB1活性增加，被H_2O_2抑制的Sirt1活性可被PARP1抑制剂(DIQ)逆转。PARP1和Sirt1是两种依赖NAD+的酶，它们在决定细胞在应激环境中的生存或死亡方面发挥着重要作用。我们发现NAD+的耗竭归因于DNA损伤后PARP1的激活，这是由肝细胞内的氧化应激引起的，并导致Sirt1活性抑制。相反，Sirt1通过负调控PARP1的基因表达和去乙酰化来抑制PARP1。结论PARP1和Sirt1之间的功能抑制导致HMGB1高乙酰化，导致HMGB1从胞核移位到胞浆，最后移位到细胞外。
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.
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影响因子：
--
作者：
Luna A;Aladjem MI;Kohn KW
通讯作者：
Kohn KW
影响因子：
24.1
作者：
通讯作者：
--
影响因子：
13.8
作者：
Malarkey, Christopher S.;Churchill, Mair E. A.
通讯作者：
Churchill, Mair E. A.
影响因子：
19.6
作者：
通讯作者：
--
DOI：
10.1073/pnas.1706981114
发表时间：
2017-08-15
影响因子：
11.1
作者：
Robu, Mihaela;Shah, Rashmi G.;Shah, Girish M.
通讯作者：
Shah, Girish M.