PAI-1对炎症性肠病大鼠模型内质网应激的相关影响研究

Effect of PAI-1 on endoplasmic reticulum stress in rats with inflammatory bowel disease

目的探究纤溶酶原激活剂抑制物-1(PAI-1)基因对炎症性肠病(IBD)大鼠模型内质网应激的相关影响。方法将Wistar大鼠24只分为正常对照(control)组、IBD大鼠模型(IBD)组、Knockout PAI-1正常大鼠模型(Knockout PAI-1 control)组、Knockout PAI-1+IBD大鼠模型(Knockout PAI-1+IBD)组,每组6只。采用2,4,6-三硝基苯磺酸(TNBS)/无水乙醇法进行IBD造模,3d后腹腔注射3%戊巴比妥钠1.5ml/kg麻醉,迅速剖腹,剪下肛门以上7~8cm结肠,HE染色检测各组大鼠结肠组织病理情况,qRT-PCR检测PAI-1、IL-6、IFN-γ和重链结合蛋白(BIP)转录水平;Western blot检测各组大鼠PAI-1、IL-6、IL-10、IFN-γ、BIP、p-IRE1α、p-JNK及JNK蛋白表达水平。结果control组与Knockout PAI-1 control组镜下未见明显炎症活动;Knock out PAI-1+IBD组的肠壁炎症程度较Knockout PAI-1 control组轻。基因转录表达方面,与control组相比较,IBD大鼠组PAI-1、IL-6、IFN-γ和BIP转录水平均明显上调(均P<0.01),IL-6、IL-10、IFN-γ、BIP、p-IRE1α、JNK蛋白表达水平明显上调;而Knockout PAI-1+IBD组与IBD组相比,炎症情况减轻,IL-6、IFN-γ和BIP转录表达水平明显下调(P<0.01),IL-6、IL-10、IFN-γ、BIP、p-IRE1α、JNK蛋白表达水平显著下调,PAI-1转录水平及蛋白表达水平无统计学差异。结论抑制PAI-1基因的表达可能改善了IBD大鼠组织炎症及内质网应激水平。

Objective To investigate the effect of plasminogen activator inhibitor-1(PAI-1)on endoplasmic reticulum stress in rats with inflammatory bowel disease(IBD).Methods Twenty-four Wistar rats were divided into four groups with 6 in each group:control group,IBD group,PAI-1 knockout group and PAI-1 knockout+IBD group.The IBD model was induced by 2,4,6-trinitrobenzene sulfonic acid(TNBS)/absolute ethanol method.The pathological grade was evaluated using HE staining.The gene transcriptional levels of PAI-1,IL-6,IFN-γ,BIP were measured by quantitative real-time PCR(qRT-PCR).The protein expression levels of PAI-1,IL-6,IL-10,IFN-γ,BIP,p-IRE1α,p-JNK,JNK were measured by Western blot.Results HE staining showed that there was no significant inflammatory activity in control group and PAI-1 knockout group,and the degree of intestinal wall inflammation in the PAI-1 knockout+IBD group was lighter than that in the IBD group.Compared with IBD group,the mRNA expression levels of PAI-1,IL-6,IFN-γ,BIP and the protein expression levels of PAI-1,IL-6,IL-10,IFN-γ,BIP,p-IRE1α,p-JNK in PAI-1 knockout+IBD group were down-regulated(P<0.01).Conclusion Inhibition of the PAI-1 expression may improve tissue inflammation and endoplasmic reticulumstress in IBD rats.