熊果酸对肝纤维化大鼠NOX2/ROS/NLRP3炎性小体活化的影响

摘要

Objective To investigate the effect of ursolic acid(UA) on NOX2/ROS/NLRP3 inflammasome activation in carbon tetrachloride(CCl4)-induced liver fibrosis SD rat,and to observe the improvement of collagen deposition in liver tissues. Methods All rats were randomly divided into 3 group:control group,CCl4model group,UA treatment group. Liver fibrosis model SD rats was established by the CCl4-induced method and half of them was used as UA treatment group. Serum ALT was detected by ALT detection kit.The liver pathology and collagen deposition were ob-served by HE and Sirius-red staining. The mRNA expression of Nox2,Nlrp3,Caspase1,IL-1β in liver tissues was detected by RT-qPCR. The protein expression of NOX2,NLRP3,caspase-1 and IL-1β in liver tissues was detected by Western blot and immunohistochemistry and the ROS generation in liver tissues was detected by DCFH-DA fluores-cence probe. Results Compared with control group,in the CCl4model group,the serum ALT was much higher (P<0.05);the Ishak's fibrosis score and collagen deposition was significantly increased(P<0.05) and mRNA of Nox2, Nlrp3,Caspase1,IL-1β was increased.In addition,both the NOX2,NLRP3,caspase-1 p10 and IL-1β protein expres-sion and ROS level (P<0.05) of CCl4model group were significant increased.Compared with CCl4model group,in the UA treatment group Ishak's fibrosis score,collagen deposition and ALT decreased.Both mRNA expression of the Nox2, Nlrp3,Caspase1,IL-1β and protein expression of NOX2,NLRP3,caspase-1 p10 and IL-1β as well as ROS were signif-icant decreased,but the caspase-1 p45 protein level has no difference among all these groups (P>0.05). Conclusions Ursolic acid attenuates the liver injury and reduces the collagen deposition,which may relate to its inhibitory effects on NOX2/ROS/NLRP3 inflammasome activation to reduce IL-1β releasing.%目的 观察熊果酸(UA)对肝纤维化模型大鼠肝内胶原沉积的改善作用及其对NADPH氧化酶2(NOX2)/活性氧簇(ROS)/NLRP3炎性小体活化的影响.方法 将大鼠随机分为对照组、CCl4模型组及UA治疗组.用CCl4诱导构建SD大鼠肝纤维化模型,一半用作UA治疗组.用试剂盒检测血清ALT含量;HE染色观察肝脏病理;天狼星红染色观察肝内胶原沉积;RT-qPCR法检测Nox2、Nlrp3、caspase1及IL-1β mRNA表达量;Western blot及免疫组化检测肝脏中NOX2、NLRP3、casepase-1 p45、caspase-1 p10及IL-1β蛋白表达;DCFH-DA荧光探针法检测肝脏组织内ROS水平.结果 与对照组相比,CCl4模型组血清ALT水平升高(P<0.05),Ishak's肝纤维化评分明显上升,胶原沉积明显增多(P<0.05),Nox2、Nlrp3、Caspase1及IL-1β mRNA的表达水平明显上升(P<0.05);NOX2、NLRP3、caspase-1 p10及IL-1β蛋白的表达均出现明显增加,肝组织内ROS含量增加(P<0.05);与CCl4模型组相比,UA治疗组血清ALT含量下降(P<0.05),肝脏Ishak's肝纤维化评分及胶原沉积减少(P<0.05),Nox2、Nlrp3、caspase1及IL-1β mRNA的表达水平明显下降(P<0.05),NOX2、NLRP3、caspase-1 p10及IL-1β蛋白表达明显下降,肝脏组织内ROS水平显著改善(P<0.05).结论 UA减轻肝脏炎性反应并减少肝内胶原沉积,其机制可能与其抑制肝纤维化大鼠肝内NOX2/ROS/NLRP3炎性小体活化及IL-1β的释放减少有关.