人肠道α-防御素5促进辐照诱导小鼠肠道损伤的修复  

Humanα-defensin 5 improves repair of irradiation-induced intestinal injury in mice

作　　者：吴杰 冉曦 王涛[2,4] 王艾平 WU Jie;RAN Xi;WANG Tao;WANG Aiping(Department of Cold Environmental Medicine,Faculty of High Altitude Military Medicine,Army Medical University(Third Military Medical University),Chongqing,400038;Department of Radiation Medicine,Faculty of Military Preventive Medicine,Army Medical University(Third Military Medical University),Chongqing,400038;Department of Clinical Laboratory,Second Affiliated Hospital,Army Medical University(Third Military Medical University),Chongqing,400037;State Key Laboratory of Trauma,Burns and Combined Injury,Chongqing,400042,China)

机构地区：[1]陆军军医大学(第三军医大学)高原军事医学系寒区医学教研室,重庆400038 [2]陆军军医大学(第三军医大学)军事预防医学系防原医学教研室,重庆400038 [3]陆军军医大学(第三军医大学)第二附属医院检验科,重庆400037 [4]创伤、烧伤与复合伤国家重点实验室,重庆400042

出　　处：《陆军军医大学学报》2023年第7期606-613,共8页Journal of Army Medical University

基　　金：国家自然科学基金面上项目(81773365)。

摘　　要：目的观察辐照对C57小鼠肠道的损伤作用及人α-防御素5(humanα-defensin 5,HD5)在其中的保护效应及功能。方法基于C57小鼠构建肠道α-防御素敲除小鼠(MMP7^(-/-)小鼠)模型,随后将HD5基因转入MMP7^(-/-)小鼠,构建HD5转基因小鼠(HD5tg小鼠)模型。将实验分为野生型C57小鼠组(WT组)、MMP7^(-/-)小鼠组和HD5tg小鼠组。利用5 Gy X射线(1.26 Gy/min)辐照各组小鼠后,统计分析30 d内小鼠生存状况,同时在0、2、10 d收取小鼠回肠组织。利用HE染色观察小鼠回肠病理损伤;TUNEL评估小鼠肠黏膜组织细胞凋亡;免疫荧光和PAS染色分析回肠肠道干细胞增殖、分化状态;Western blot检测TLR4、MyD88、NF-κB等蛋白表达;RT-qPCR检测肠黏膜IL-1、IL-6及IL-10等炎症因子转录水平。结果成功构建并繁育MMP7^(-/-)和HD5tg小鼠,WT组、MMP7^(-/-)组、HD5tg组辐照后30 d小鼠生存率分别为50%(10/20)、35%(7/20)和55%(11/20),WT组和HD5tg组小鼠生存率显著高于MMP7^(-/-)组(P<0.05),WT组和HD5tg组小鼠组间生存率无统计学差异。与MMP7^(-/-)组相比,HD5转入后显著改善小鼠辐照后小肠绒毛和隐窝结构病理损伤;抑制肠黏膜细胞发生凋亡;促进肠道干细胞增殖、分化;抑制TLR4-MyD88-NF-κB信号通路活性,进而降低IL-1β、IL-6炎性因子表达水平(P<0.05)。结论HD5通过改善辐照诱导的小鼠肠道上皮屏障功能障碍,促进肠黏膜细胞更新和组织修复,抑制炎性损伤,进而增强C57小鼠抗辐照能力。ObjectiveTo observe the damage effect of irradiation on intestine of C57 mice and investigate the protective effect and role of humanα-defensin 5(HD5)in the injury.MethodsIntestinalα-defensin knockout mice(MMP7^(-/-)mice)were constructed based on C57 mice,and HD5 gene was transferred into MMP7^(-/-)mice to construct and breed a HD5 transgenic mice(HD5tg mice).The experiment was divided into wild-type C57 mice group(WT group),MMP7^(-/-)mice group and HD5tg mice group.After the mice were irradiated with 5 Gy X-ray(1.26 Gy/min),the survival status of mice within 30 d was observed and statistically analyzed,and the ileal tissues were collected at 0,2 and 10 d.The pathological injury of the ileum was observed with HE staining,the cell apoptosis in the mice intestinal mucosa was evaluated by TUNEL,and the proliferation and differentiation of ileum intestinal stem cells were analyzed with immunofluorescence assay and PAS staining.The protein expression of TLR4,MyD88 and NF-κB was detected with Western blotting,and the transcription levels of IL-1,IL-6 and IL-10 in intestinal mucosa were measured with RT-qPCR.ResultsMMP7^(-/-)mice and HD5tg mice were successfully constructed in this study.At 30 d after irradiation,the survival rates of WT,MMP7^(-/-)and HD5tg groups were 50%(10/20),35%(7/20)and 55%(11/20),respectively.The survival rates of WT and HD5tg groups were significantly higher than that of MMP7^(-/-)group(P<0.05),but there was no statistic difference between WT group and HD5tg group.When compared with MMP7^(-/-)group,HD5 transfer significantly improved the pathological damage of villi and crypt structure in the small intestine of mice after irradiation,inhibited the apoptosis of intestinal mucosal cells,promoted the proliferation and differentiation of intestinal stem cells,and decreased transcription levels of inflammatory factors via inhibiting TLR4-MyD88-NF-κB signaling pathway(P<0.05).ConclusionHD5 promotes the renewal of intestinal mucosal cells and tissue repair and inhibit inflammatory injury by improvi

关 键 词：辐照 放射性肠损伤 金属基质蛋白酶7 人α-防御素5 

分 类 号：R322.45[医药卫生—人体解剖和组织胚胎学] R818.74[医药卫生—基础医学] R977.4