在肠缺血再灌注下骨形成蛋白-4下调IL-7/IL-7R信号促进肠上皮间淋巴细胞凋亡的研究  

Bone morphogenetic protein-4 promote apoptosis of intestinal intraepithelial lymphocytes through downregulate IL-7/IL-7R signaling after ischemia-reperfusion condition

作　　者：罗彬予 张琴[2] 张朝军[3] 田云鸿[1] 任明扬[1] LUO Binyu;ZHANG Qin;ZHANG Chaojun;TIAN Yunhong;REN Mingyang(Department of Gastrointestinal Surgery, The Second Clinical School of Northern Sichuan Medical College, Nanchong Central Hospital, Nanchong 637000, Sichuan, China;Department of Rehabilitation Medicine, The Affiliated Hospital of Zunyi Medical College, Zunyi 663003, Guizhou, China;Department of General Surgery, Naval General Hospital ,PLA, Beijing 100048, China)

机构地区：[1]川北医学院第二临床医学院.南充市中心医院胃肠外科,四川南充637000 [2]遵义医学院附属医院康复医学科,贵州遵义563000 [3]中国人民解放军海军总医院普通外科,北京100048

出　　处：《西部医学》2018年第6期803-808,共6页Medical Journal of West China

基　　金：国家自然科学基金项目(NSFC 81071532;NSFC 81370479);四川省卫生和计划生育委员会科研课题(17PJ200)

摘　　要：目的探讨小鼠小肠在肠缺血再灌注(I/R)条件下骨形成蛋白(BMP-4)通过下调IL-7/IL-7R信号通路促进IELs凋亡的机制。方法建立小鼠小肠I/R损伤模型,随机分为手术组(I/R组)、假手术组(Sham组),每组各16只,免疫荧光检测IECs中IL-7蛋白和流式细胞术检测IELs中IL-7受体(CD127)及STAT5蛋白磷酸化水平变化;外源性BMP-4蛋白刺激IEC-6培养6小时后,Western blot检测IEC-6中IL-7蛋白表达变化;分离培养正常小鼠IELs,分别加入外源性BMP-4蛋白及BMP4拮抗剂NOGGIN蛋白刺激,流式细胞术观察BMP4对IELs中IL-7受体(CD127)及STAT5蛋白磷酸化变化;分离培养正常小鼠IELs,分别加入外源性BMP-4蛋白及IL-7蛋白刺激,观察IELs凋亡率的变化。结果在I/R刺激下,IECs中IL-7蛋白表达I/R组较Sham组明显减少(P<0.05);IELs中IL-7受体(CD127)及STAT5蛋白磷酸化水平均较Sham组表达减少(P<0.05);体外培养实验发现:IECs中IL-7蛋白表达在BMP-4刺激下明显减少,IELs单独培养给予BMP4蛋白刺激后CD127及P-STAT5较Sham组减少(P<0.05);给予BMP特异性拮抗剂RNOGGIN可逆转BMP对IL-7/IL-7R信号通路的抑制作用;BMP-4促进IELs的凋亡率增加(P<0.05),给予外源性IL-7蛋白刺激后,有效的抑制IELs的凋亡率增加(P<0.05),BMP-4抑制IL-7对IELs的增殖作用,促进IELs的凋亡。结论小肠在I/R条件下,肠上皮细胞中BMP-4蛋白抑制IL-7/IL-7R信号通路,使IELs的保护性细胞因子减少,从而促进IELs的凋亡率增加,进一步加重肠免疫屏障损伤。Objective To explore the mechanism of the bone morphogenetic protein-4 （BMP-4） promote apoptosis of intestinal intraepithelial lymphocytes through downregulating IL-7/IL-7R signaling after I/R. Methods Mouse intestinal I/R model was established. The mice were randomly divided into I/R group and sham operation group. IL-7 protein expression in IECs （immunofluorescence） and IL-7 receptor（CD127） and phosphorylation of STAT5 proteins in IELs （flow cytometry） were detected. Western-boh detect the change of IL-7protein expression after treating the IEC-6 with exogenous BMP-4 protein for 6 hour. IELs were stimulated with exogenous BMP4 and BMP4 antagonist NOGGIN protein. IL-7 receptor （CD127） and P-STAT5 proteins expression were measured by flow cytometry. IEL was stimulated with exogenous BMP-4 and IL-7 protein. The apoptosis was detected. Results The IL-7 protein secretion of I/R group significantly decreased, compared with that of sham group after I/R in IECs. The IL-7 receptor （CD127） and P-STAT5 expression of I/R group were also decreased after I/R in IELs（P〈0.05）. Under condition of exogenous BMP-4 stimulation, the expression of IL-7 protein was decreased in IEC-6, and the expression of CD127 and P-STAT5 protein also decreased in IELs（P〈0.05）. The apoptosis of IELs were significantly increased with BMP-4 protein stimulation than the control group（P〈0.05）. However, IL-7 protein can promote the apoptosis of IELs（P〈0.05）. Conclusion The IECs derived BMP-4 protein downregulates IL-7/IL-7R signaling pathway in I/R. The protective factors of IELs are decreased, and the apoptosis rate of IELs is increased.

关 键 词：肠缺血再灌注 骨形成蛋白-4 白细胞介素-7 肠上皮间淋巴细胞 

分 类 号：R656.7[医药卫生—外科学]