肠源性内毒素与Treg在重症急性胰腺炎肝损伤中的作用

摘要

目的 探讨肠源性内毒素(ET)及CD4+ CD25+调节性T细胞(Treg)在重症急性胰腺炎(SAP)肝损伤中的作用.方法 雄性Wistar大鼠60只,随机分成假手术组(SO组)和SAP组.逆行性胰胆管注射牛磺胆酸钠造模.分别于术后3、6、12 h留取标本,检测血淀粉酶及丙氨酸转氨酶水平,鲎试剂法测血浆内毒素含量,流式细胞术测外周血Treg百分数,肝脏及胰腺行病理组织学观察,免疫组化法测肝脏组织Foxp3表达,并对以上指标进行相关性分析.结果 病理组织学观察及丙氨酸转氨酶水平证实,SAP组肝脏出现病理性形态改变.与SO组相比,SAP各组Treg百分数显著升高(SAP组3、6、12h分别为:2.26％±0.32％、2.36％±0.48％、2.80％±0.35％),差异有统计学意义(P＜0.01).SAP各组ET水平与SO组相比,差异有统计学意义(P＜0.01),与12 h(0.85±0.11)相比,3 h(0.74±0.11)和6 h(0.78±0.07)差异无统计学意义(P＞0.05).SAP各组肝脏Foxp3蛋白表达明显上调,Treg的表达与ET呈正相关(r=0.89,P＜0.01).结论 SAP可致肝损伤,ET与Treg细胞在SAP肝损伤中可能发挥重要作用.%Objective To investigate the role of CD4+ CD25+ regulatory T cells(Treg) in peripheral blood and intestinal endotoxin (ET) in liver injury of rat severe acute pancreatitis (SAP).Methods Sixty male Wistar rats were randomly allocated into sham operation group(SO group) and severe acute pancreatitis group(SAP group).The rats in SAP group recevied the injection of Sodium Taurocholate(NaTc) into their far-end of bile-pancreatic duct and were sacrificed in 3-,6-and 12-hour,serum amylase(AMY) and alanine aminotransferase(ALT) determined by full-automatic biochemistry instrument,limulus reagent method is used to determine ET content in plasma,the proportion of Treg among peripheral lymphocytes was determined by Flow Cytometry(FCM),HE stain is used to observe pathological changes in liver and pancreas,the protein of Foxp3 activity was evaluated by immunohistochemistry staining,and the relationships between these indicators were analyzed using Pearson correlation analysis test.Results Histopathologic examination and the level of ALT revealed the occurrence of pancreatic inflammation and pathological changes of liver in SAP group.The percentage of Treg in SAP groups significantly increased at 3 h(2.26％ ±0.32％),6 h(2.36 ％ ±0.48％)and 12 h(2.80％ ±0.35％) comparing to the SO groups(P＜0.01) ; plasma ET levels compared with the SO group was statistically significant (P＜ 0,01 ),and 12 h (0.85 ± 0.11) compared to,3 h (0.74±0.11) and 6 h (0.78-±-0.07) was no significant difference (P＞0.05).The expression of Foxp3 protein on the livers were upregulated markedly.Pearson correlation analysis teat showed that quantities of Treg were positively proportional to the levels of ET(r=0.89,P＜0.01) after liver injury of SAP.Conclusions SAP may lead to liver injury and the high plasma levels of ET and Treg in peripheral blood may play an important role in liver injury of SAP.