睡眠剥夺小鼠肝脏中肿瘤坏死因子α表达上调

Upregulation of tumor necrosis factor-α expression in livers of sleep deprived mice

目的探讨睡眠剥夺(sleep deprivation,SD)对小鼠肝脏形态、功能的影响及肿瘤坏死因子α(tumor necrosis factor,TNF-α)表达的意义。方法 C57雄性小鼠随机分为正常对照组、睡眠剥夺24h、48h和72h组,全自动生化分析仪检测血清中谷丙转氨酶(alanine aminotransferase,ALT),谷草转氨酶(aspartate aminotransferase,AST)的活性,硫代巴比妥酸法检测肝组织丙二醛(malonaldehyde,MDA)含量,黄嘌呤氧化酶法检测肝组织超氧化物歧化酶(superoxidedismutase,SOD)活性;采用HE染色检测肝组织学特征,免疫组织化学染色和Western blot检测肝组织TNF-α表达水平。结果随睡眠剥夺时间延长肝脏组织中,SOD表达量下降,MDA表达量增加;ALT、AST水平在睡眠剥夺24h后显著增高,48h、72h表达水平持续增高;HE染色可见睡眠剥夺组小鼠出现肝细胞肿胀、排列不规则、肝小叶结构破坏、Kupffer细胞增生、大量炎症细胞浸润;免疫组织化学及免疫印迹显示,睡眠剥夺组小鼠肝脏中TNF-α的表达随睡眠剥夺时间的延长而表达持续增加。结论睡眠剥夺后肝细胞过氧化脂质作用诱发氧化应激导致小鼠肝脏形态和功能受损,活化TNF-α,诱发炎症反应,加重对肝脏的损害。

Objective To investigate the impact of sleep deprivation on morphology,functions and tumor necrosis factor(TNF-α)expression in livers of mice.Methods C57male mice were randomly divided into four groups:control versus groups with sleepdeprivation for24h,48h,or72h respectively.Serum alanine aminotransferase(ALT)and aspartate aminotransferase(AST)levels inliver tissue were determined using automatic biochemical analyzer.The contents of superoxide dismutase(SOD)and malondialdehyde(MDA)in liver tissue were measured by xanthine oxidase method and thiobarbituric acid method.HE staining was used to analyze thehistological features of liver.The expression of TNF-αin liver tissue was detected by immunohistochemical staining and western blot.Results With prolonged sleep deprivation,the expression of SOD decreased and the expression of MDA increased in liver tissue.ALTand AST levels significantly increased at24h and continued to rise over the rest of time course.HE staining showed swollen and irregularlyarranged hepatocytes,hepatic lobular structure destruction,Kupffer cell proliferation,and extensive inflammatory cell infiltration.Immunohistochemistry and immunoblotting showed that the increased expression of TNF-αin the liver was associated with prolongedsleep deprivation time.Conclusion The elevated lipid peroxidation in response to sleep deprivation induces oxidative stress which maylead to impaired liver morphology and functions.Upregulation of TNF-αelicits inflammatory response,which may further contributeto liver damage.