电离辐射对小鼠肠道隐窝素4表达的影响及意义  

Alteration and significance of small intestinal cryptdin 4 in ionizing-radiated mice

作　　者：曹乐[1] 王成[1] 申明强[1] 王艾平[1] 陈芳[1] 耿放[1] 陈默[1] 张乃心[1] 粟永萍[1] 程天民[1] 王军平[1] 

机构地区：[1]第三军医大学军事预防医学院全军复合伤研究所,防原医学教研室,创伤,烧伤与复合伤国家重点实验室,重庆市纳米医药工程技术研究中心,重庆400038

出　　处：《第三军医大学学报》2015年第4期330-334,共5页Journal of Third Military Medical University

基　　金：全军后勤科研重点项目(BWS11J009);国家自然科学基金(81271898;81172600)~~

摘　　要：目的检测小鼠受电离辐射后隐窝素4(cryptdin 4,Crp4)的表达变化,探讨其在电离辐射肠损伤中的生物学意义。方法 8周龄BALB/c小鼠采用随机数字表法分为两组,未辐照组(n=5)和辐照组(n=15),辐照组给予8 Gy X射线全身一次性照射,分别于照后9、24、72 h取小鼠小肠组织和眼球血。免疫组织化学染色和Western blot分析小鼠小肠Paneth细胞隐窝素Crp4的表达变化,鲎试剂法检测小鼠血清LPS水平。化学合成Crp4多肽,采用涂布克隆计数法分析Crp4对肠道条件致病菌(大肠杆菌、粪肠球菌)和益生菌(乳酸杆菌、双歧杆菌)的抗菌活性;同时,观察Crp4对LPS诱导促炎因子IL-1β生成的影响。结果与对照组相比,小鼠电离辐射后小肠Crp4表达水平升高,72 h升高尤为显著(P<0.01);辐照小鼠血清LPS含量在9 h后显著增加(P<0.05),72 h后升高最为明显(P<0.01);Crp4对条件致病菌(大肠杆菌、粪肠球菌)的抗菌活性显著强于益生菌(乳酸杆菌、双歧杆菌),并能抑制LPS诱导单核巨噬细胞IL-1β的生成(P<0.01)。结论电离辐射可以诱导小鼠肠道隐窝素Crp4的表达上调,Crp4表达上调可发挥调节肠道菌群、减轻机体炎症反应的作用。Objective To observe the effect of ionizing radiation on the expression of mouse cryptdin4（ Crp4） and explore the biological significance. Methods BALB / c mice（ 8 weeks old） were randomly divided into a control group（ n = 5） and a radiated group（ n = 15）,and the radiated group was treated by total-body ionizing radiation（ 8 Gy X-ray）. The small intestinal tissue and eyeball blood were collected before and after ionizing radiation（ at 9,24,and 72 h respectively）. Immunohistochemical assay and Western blot analysis were employed to detect the alteration of Crp4 in mouse small intestine. Quantitative chromogenic tachypleus amebocyte lysate test was used to analyze the alteration of lipopolysaccharide（ LPS） in blood serum. Crp4 peptide was obtained through chemical synthesis. Colony counting was employed to assess the antibacterial activity of Crp4 against Escherichia coli,Enterococcus faecalis,Lactobacillus acidophilus,and Bifidobacterium bifidum. Also,the effect of Crp4 on the release of IL-1β from mouse RAW264. 7 cells after LPS simulation was evaluated. Results The expression of Crp4 in the mouse small intestine was increased after ionizing radiation,and the alteration was the most remarkable at 72 h（ P〈 0. 01）. The serum LPS level of the radiated mice was significantly increased after 9 h（ P〈 0. 05）,and peaked after 72 h（ P〈 0. 01）.Conditional pathogenic bacteria（ Escherichia coli and Enterococcus faecalis） were more sensitive to Crp4 than probiotics（ Lactobacillus acidophilus and Bifidobacterium bifidum）. Moreover,it was found that Crp4 could decrease the release of IL-1β from RAW264. 5 cells stimulated with LPS. Conclusion Ionizing radiation can induce the up-regulation of Crp4 expression,which might play an important role in the regulation of the intestinal flora and relieve of the inflammatory responses.

关 键 词：电离辐射 隐窝素4 抗菌 LPS IL-1Β 

分 类 号：R322.45[医药卫生—人体解剖和组织胚胎学] R392.3[医药卫生—基础医学]