胸腺素α1对酵母多糖诱导多器官功能衰竭模型大鼠肝损伤的保护

Thymosin alpha1 protects against liver injury in rats with zymosan-induced multiple organ failure

背景:多器官功能衰竭模型中的肝损伤给临床医师的用药造成较大的困扰,胸腺素α1用于慢性肝炎的治疗,对肝损伤具有明显的保护作用。目的:基于ADPN/Akt/NF-κB信号通路探讨胸腺素α1对多器官功能衰竭大鼠肝脏的保护机制。方法:SPF级SD雄性大鼠随机分为4组:正常组、模型组、实验组、对照组。除正常组外其余大鼠参照文献采用腹腔注射500 mg/kg酵母多糖(50 g/L)构建大鼠多器官功能衰竭模型;正常组大鼠腹腔注射等剂量生理盐水。注射30 min后,实验组、对照组大鼠每日定点分别腹腔注射2 mL的0.5 mg/kg胸腺素α1和甘草酸二铵注射液,正常组和模型组腹腔注射等剂量生理盐水。在连续给药7 d后,进行肝功能检测;采用苏木精-伊红染色、TUNEL染色检测大鼠肝组织病理学改变及细胞凋亡率;采用免疫组化、Western blot检测大鼠肝组织白细胞介素10、肿瘤坏死因子α的水平及脂联素、AdipoR2、p-AKT和核转录因子κB的蛋白表达。结果与结论:①与正常组相比,模型组大鼠血清中丙氨酸转氨酶、天冬氨酸转氨酶、总胆红素、肝损伤病理评分、细胞凋亡率、肿瘤坏死因子α水平及核转录因子κB的蛋白表达明显升高,总蛋白、白细胞介素10水平及脂联素、AdipoR2、p-AKT的蛋白表达明显降低(均P<0.05);与模型组相比,实验组和对照组大鼠血清中丙氨酸转氨酶、天冬氨酸转氨酶、总胆红素、肝损伤病理评分、细胞凋亡率、肿瘤坏死因子α水平及核转录因子κB的蛋白表达明显降低,总蛋白、白细胞介素10水平及脂联素、AdipoR2、p-AKT的蛋白表达明显升高(均P<0.05);②结果说明,胸腺素α1对酵母多糖诱导的多器官衰竭大鼠的肝脏有保护作用,其机制与ADPN/Akt/NF-κB信号通路信号通路有关,ADPN/Akt被激活,抑制核转录因子κB的活化,从而减轻炎症反应。

BACKGROUND:Liver injury in a multiple organ failure model causes great troubles to clinicians’medication.Thymosinα1 is used for treating chronic hepatitis and it has obvious protective effects against liver injury.OBJECTIVE:To investigate the protective mechanism of thymosinα1 on liver injury in a rat model of multiple organ failure,based on adiponectin(ADPN)/protein kinase B(Akt)/nuclear factorκB(NF-κB)signaling pathway.METHODS:Male SPF Sprague-Dawley rats were randomly divided into four groups:normal group,model group,experimental group,and control group.Rats in the model group,experimental group,and control group were given intraperitoneal injection of 500 mg/kg zymosan(50 g/L)to construct the rat multiple organ failure model.Normal rats were injected intraperitoneally with equal doses of normal saline.Thirty minutes after the injection,the rats in the experimental group and the control group were injected intraperitoneally with 2 mL of thymosinα1 and ganlixin with the dose of 0.5 mg/kg daily,respectively.The normal group and the model group were injected intraperitoneally with the same dose of normal saline.After 7 days of continuous administration,liver function parameters were tested;histopathological changes of rat liver tissues and cell apoptosis were detected using hematoxylin-eosin staining and TUNEL staining;immunohistochemistry and western blot were used to detect the expression of interleukin-10,tumor necrosis factorα(TNF-α),adiponectin(ADPN),adiponectin recepror 2,AdipoR2,p-AKT and NF-κB.RESULTS AND CONCLUSION:Compared with the normal group,the levels of alanine aminotransferase,aspartate aminotransferase,total bilirubin in the serum,the pathological scores of liver injury,the cell apoptotic rate,and the expression levek of TNF-αand NF-κB were significantly increased in the model group,while the serum levels of total protein,interleukin-10,ADPN,AdipoR2 and p-AKT were significantly reduced in the model group(all P<0.05).Compared with the model group,the serum levels of alanine aminotransferase,aspartate aminotransferase,total bilirubin,the pathological scores of liver injury,and cell apoptotic rate in the experimental group and control group were significantly reduced,and the serum levels of total protein,interleukin-10,ADPN,AdipoR2 and p-AKT were significantly increased(all P<0.05).To conclude,thymosinα1 has a protective effect on the liver of rats with multiple organ failure induced by zymosan.The mechanism is related to the ADPN/Akt/NF-κB signaling pathway.ADPN/Akt is activated and the activation of NF-κB is inhibited,then reducing the inflammatory response.