慢性间歇性低氧激活NLRP1炎性小体引起小鼠肝损伤

Chronic intermittent hypoxia activates NLRP1 inflammasome and causes liver injury

目的 探讨慢性间歇性低氧(CIH)是否能激活含pyrin结构域核苷酸结合寡聚结构域样受体家族蛋白1(NLRP1)炎性小体引起肝损伤。方法 将C57BL/6雄性小鼠随机分为对照组、 CIH组。CIH组小鼠放入CIH仓进行造模(每天8 h,连续4周)。造模后,采用HE染色观察肝组织细胞形态、试剂盒检测小鼠血清中丙氨酸转氨酶(ALT)和天冬氨酸转氨酶(AST)水平,二氢乙啶(DHE)标记检测肝组织活性氧(ROS)的水平,免疫组织化学染色法检测小鼠肝组织NLRP1、含胱天蛋白酶激活和募集结构域凋亡相关斑点样蛋白(ASC)和胱天蛋白酶1(caspase-1)的表达和定位,Western blot法检测小鼠肝组织中NLRP1、 ASC、 caspase-1、白细胞介素1β(IL-1β)和肿瘤坏死因子α(TNF-α)的蛋白表达,ELISA检测小鼠血清IL-1β、 TNF-α水平。结果与对照组相比,CIH组肝细胞病变明显,细胞出现破裂、坏死、炎症细胞聚集,ALT、 AST、 ROS、 IL-1β和TNF-α水平显著升高;NLRP1、 ASC、caspase-1、IL-1β和TNF-α的蛋白表达升高。结论 CIH通过激活NLRP1炎性小体引起肝损伤。

Objective To investigate the liver injury induced by chronic intermittent hypoxia(CIH)activation of NOD-like receptor pyrin domain containing protein 1(NLRP1)inflammasome.Methods C57BL/6 male mice were randomly divided into control group and CIH group.Mice in CIH group were put into CIH chamber for molding(8 hours a day for 4 weeks).After 4 weeks of molding,liver tissue cells was observed by HE staining,and the levels of alanine aminotransferase(ALT)and aspartate aminotransferase(AST)in serum of mice were detected by kit.The levels of reactive oxygen species(ROS)in liver tissue were detected by dihydroethidine(DHE).The expression and localization of NLRP1,apoptosis speck-like protein containing a caspase activation and recruiting domain(ASC)and caspase-1 were detected by immunohistochemical staining.The protein expressions of NLRP1,ASC,caspase-1,interleukin 1β(IL-1β)and tumor necrosis factorα(TNF-α)were detected by Western blot analysis.The serum levels of IL-1βand TNF-αwere detected by ELISA.Results Compared with the control group,the CIH group exhibited significant pathological changes in hepatocytes.Hepatocytes showed signs of rupture and necrosis,accompanied by inflammatory cell aggregation.Furthermore,the levels of ALT,AST,ROS,IL-1βand TNF-αwere elevated,along with increased protein expressions of NLRP1,ASC,caspase-1,IL-1βand TNF-α.Conclusion CIH causes liver injury by activating NLRP1 inflammasome.