Toll样受体4在猪急性坏死性胰腺炎肠道组织中的表达及其意义

Signif icance of expression of Toll-like receptor 4 in the intestinal tract of pigs with acute necrotizing pancreatitis

目的:探讨猪急性坏死性胰腺炎(acute necrotizing pancreatitis,ANP)回肠组织中Toll样受体4(Toll-like receptor4,TLR4)的表达及其意义.方法:选择太湖梅山猪,随机分成对照组(C,n=4)、急性坏死性胰腺炎组(ANP,n=4).诱导制备ANP模型.用分光光度法检测血清及回肠组织匀浆中二胺氧化酶(DAO)活性;动态比浊法检测血浆内毒素水平;RT-PCR检测回肠黏膜组织TLR4、TNF-α及IL-6mRNA表达.结果:ANP组回肠组织DAO水平明显低于C组,血清中DAO明显升高(P<0.05).ANP组血浆内毒素水平较C组明显升高(P<0.05);回肠黏膜组织TLR4、TNF-α、IL-6mRNA在C组表达非常低,ANP组表达明显增加;TLR4mRNA表达水平与肠黏膜DAO水平呈负相关(r=-0.762,P=0.028),与血浆内毒素呈正相关(r=0.778,P=0.023).结论:ANP时回肠组织内TLR4mRNA表达上调,可能与ANP肠黏膜屏障功能障碍有关;其可能机制与TLR4介导激活核转录因子NF-αB信号转导途径有关.

AIM：To detect the expression of Toll-like receptor 4 gene（TLR4） in the ileum of pigs with acute necrotizing pancreatitis（ANP）.METHODS：Eight pigs were randomized into ANP group and control group.ANP was induced by retrograde injection of sodium taurocholate.Blood levels of DAO were measured at various time points.Endotoxin concentration was determined using a commercial kit.The expression of tumor necrosis factor alpha（TNF-α）,interleukin（IL）-6 and Toll-like receptor（TLR） 4 mRNAs in the ileum was assayed by reverse transcriptionpolymerase chain reaction（RT-PCR）.RESULTS：Compared to the control group,plasma endotoxin concentrations and serum DAO levels increased significantly（both P 0.05）,DAO levels in the ileal tissue homogenate decreased（P 0.05）,and expression of TLR4,TNF-α,and IL-6 mRNAs was significantly upregulated（all P 0.05） in the ANP group.The expression levels of TLR4 mRNA were correlated with DAO levels in ideal tissue（r =-0.762,P = 0.028） and plasma endotoxin concentrations（r = 0.778,P = 0.023）.CONCLUSION：Expression of TLR4 mRNA increased in the ileum of ANP pigs,and TLR4 mRNA overexpression may correlate with intestinal mucosa injury and development of enterogenic infection.