重症急性胰腺炎大鼠血浆中6种线粒体N-甲酰肽及胰腺FPR1的表达研究

The expression of six kinds of mitochondrial N-formyl peptides in plasma and pancreatic FPR1 in severe acute pancreatitis rats

目的检测重症急性胰腺炎(SAP)大鼠血浆中6种线粒体N-甲酰肽(NFPs)及胰腺中甲酰肽受体1(FPR1)的表达情况,探讨其与SAP病程进展的关系。方法30只雄性SD大鼠按随机数字表法分为假手术组、SAP模型3 h组和SAP模型6 h组,每组10只。假手术组仅在开腹后轻轻翻动胰腺后关闭腹腔;SAP模型3 h组和SAP模型6 h组均通过胆胰管内逆行注射5%牛磺胆酸钠(50 mg/kg)制备SAP大鼠模型,并分别于SAP造模3 h后和SAP造模6 h后取材。苏木素-伊红染色法观察胰腺组织病理变化;免疫组织化学法检测胰腺中FPR1的表达水平;蛋白质免疫印迹法检测血浆中6种线粒体NFPs的表达水平。结果与假手术组比较,SAP模型3 h组和SAP模型6 h组的胰腺均发生明显出血、腺泡细胞坏死、炎性细胞浸润、水肿等病理改变,病理评分明显升高,且SAP模型6 h组更高(P<0.05)。免疫组化结果显示SAP模型3 h组和SAP模型6 h组的胰腺组织FPR1表达水平均较假手术组升高,SAP模型6 h组更高(P<0.05)。6种线粒体NFPs的表达水平出现不同变化,其中MT-ND1、MT-ND3和MT-ND6随着SAP造模时间延长表达逐渐增加(P<0.05),MT-ND4则呈递减趋势(P<0.05),MT-ND5在3组中表达无明显差异。结论FPR1和部分线粒体N-甲酰肽与SAP病程进展密切相关,且可能与SAP的过度炎症反应和炎症级联放大有关。

Objective To detect the expression levels of six mitochondrial N-formyl peptides(NFPs)in plasma and formyl peptide receptor 1(FPR1)in pancreas of rats with severe acute pancreatitis(SAP),and to explore the correlation between them and the progression of SAP.Methods Thirty male SD rats were divided into the sham operation group,the SAP model 3 h group and the SAP model 6 h group by random number table method,with 10 rats in each group.In the sham operation group,the pancreas was turned slightly after laparotomy,and then the abdominal cavity was closed.SAP rat model was prepared in the SAP groups by retrograde injection of 5%sodium taurocholate(50 mg/kg)into the biliary duct.The expression levels of six mitochondrial NFPs in plasma were detected by Western Blotting.The pathological changes of pancreatic tissue were observed by hematoxylin-eosin staining.Immunohistochemistry was used to detect the protein expression of FPR1 in pancreas.Results Compared with the sham operation group,pancreatic hemorrhage,acinoid cell necrosis,inflammatory cell infiltration,edema and other pathological changes occurred in the SAP model 3 h group and the SAP model 6 h group,and the pathological scores were significantly increased,especially in the SAP model 6 h group(P<0.05).Immunohistochemical results showed that the expression levels of FPR1 in pancreatic tissue were significantly higher in the SAP model 3 h group and the SAP model 6 h group than that of the sham group,especially in the SAP model 6 h group(P<0.05).The expression levels of six mitochondrial NFPs were varied.The expression levels of MT-ND1,MT-ND3 and MT-ND6 were gradually increased with the prolonging of SAP modeling time(P<0.05),while MT-ND4 showed adecreasing trend(P<0.05).There was no significant difference in the expression of MT-ND5 between the three groups.Conclusion FPR1 and some mitochondrial N-formyl peptides are closely associated with the progression of SAP,and which may be related to the excessive inflammatory response and amplification of inflammatory cascade in SAP.