Toll样受体4在重症急性胰腺炎大鼠胰腺组织中的表达和作用

Role and expression of TLR4 in pancreatic tissue of rat with severe acute pancreatitis

目的:探讨Toll样受体4(TLR4)在实验性重症急性胰腺炎(severe acute pancreatitis,SAP)中的表达和作用。方法:32只雄性Sprague-Dawley大鼠随机分为对照组(NC组)和3组SAP(3h、6 h、12 h),每组8只。以4%牛磺胆酸钠胰胆管逆行注射诱导SAP模型。动态测定各组血清淀粉酶(AMY)水平;光镜下观察胰腺大体及组织学表现;ELISA方法测定大鼠血清中IL-1β、IL-6的表达情况;蛋白印迹法(Western blot)和免疫组织化学法测定胰腺组织中TLR4的定位和表达。结果:与NC组相比,SAP各组AMY水平均明显升高(P<0.05);光镜下胰腺组织损伤随病情进展而逐渐加重;各组血清中均有IL-1β、IL-6表达,与NC组比较,SAP各组IL-1β、IL-6表达水平显著上调(P<0.05);NC组有极少量的TLR4表达,SAP各组TLR4蛋白表达明显高于NC组,且随造模时间延长逐渐增高(P<0.05);TLR4表达变化与胰腺组织的严重程度和血清炎症因子的变化均一致。结论:TLR4在SAP的发病和病情变化中起到非常重要的促炎作用。

AIM： To investigate the mechanism of Toll-like receptor 4 （ TLR4 ） in experimental severe acute pancreatitis （SAP）. METHODS ： The rat model of SAP was reproduced by retrograde in- jection of 4% sodium tauroeholate into the bilio-pan- creatic duct. Thirty-two male SD rats were randomly assigned into 4 groups （8 each ）： normal control group （NC） , SAP 3 h, 6 h, and 12 h groups. The level of serum amylase （AMY） was measured dy- namically. The pathological changes in pancreas were observed under the light microscope, The con- centration of IL-1β, IL-6 were determined by ELISA. The localization and expression of TLR4 protein in pancreas were determined by immunohis- tochemical staining and Western blotting. RESULTS：Compared with NC group, serum level of AMY increased significantly in SAP group （P 〈0.05 ） , and the pancreas injuries under the light mi- croscope were gradually aggravated with disease pro- gression. The serum concentration of IL-1β, IL-6 in the SAP groups increased significantly compared with NC group （P 〈 0.05 ）. The concentration of TLR4 protein in NC group was little, the concentra- tion of TLR4 protein in SAP groups increased signifi- cantly compared with that in NC groups （P 〈 0.05 ）. The change of TLR4 protein concentration is in accordance with the severity of pancreas tissue as well as the serum concentration of IL-1β, IL-6. CONCLUSION： TLR4 plays an important role in triggering inflammatory response of SAP.