自然衰老与D-半乳糖诱导的衰老大鼠肠道形态学和上皮紧密连接蛋白表达的对比研究  

A comparative study on the intestinal morphology and expression of tight junction proteins in epithelial cells of the aging rats induced by natural senescence and D-galactose

作　　者：任卫英[1] 李锂[1] 吴克芬[1] 李希[1] 胡予[1] 

机构地区：[1]复旦大学附属中山医院老年病科,上海市200032

出　　处：《老年医学与保健》2016年第4期215-218,222,共5页Geriatrics & Health Care

基　　金：国家自然科学基金(81570795)

摘　　要：目的研究自然衰老大鼠和D-半乳糖诱导的衰老模型大鼠肠道组织形态学、小肠黏膜上皮细胞间紧密连接蛋白表达的变化,评估两种衰老模型大鼠肠道屏障结构和功能。方法将大鼠分为26月龄组(A组)、D-半乳糖组(B组)和3月龄组(C组)3组。取各组大鼠回肠组织常规HE染色观察形态学改变,透射电镜下观察肠上皮细胞间紧密连接超微结构,采用Real-time PCR检测小肠黏膜组织中紧密连接蛋白(ZO-1和Occludin)的mRNA表达,采用Western blot检测ZO-1和Occludin的蛋白表达。结果 A组和B组大鼠小肠黏膜厚度及绒毛高度均比C组大鼠降低[小肠黏膜厚度:A组(89.88±6.12)μm、B组(87.62±6.32)μm、C组(162.91±7.28)μm,P<0.05;绒毛高度:A组(59.95±4.47)μm、B组(56.43±5.38)μm、C组(108.12±6.42)μm,P<0.05]。透射电镜下观察到A组和B组大鼠的肠上皮细胞间紧密连接比C组疏松,间隙增宽,密度降低。与C组比较,A组和B组大鼠的小肠组织中ZO-1、Occludin mRNA和蛋白的表达均减少(均P<0.05)。而A组与B组大鼠的小肠黏膜厚度、绒毛高度、小肠组织中ZO-1、Occludin mRNA和蛋白表达水平差异无统计学意义。结论自然衰老大鼠和D-半乳糖诱导的衰老模型大鼠小肠黏膜结构和上皮屏障功能均受损,小肠黏膜厚度、绒毛高度等肠道组织形态学指标,上皮细胞间紧密连接结构的改变和紧密连接蛋白表达下调等变化具有高度一致性。Objective To study the changes of the intestinal morphology and the expression of tight junction proteins in the small intestinal epithelium in natural aging rats and aging model rats induced by D-galactose, and to evaluate the structure and function of the intestinal barrier in these two aging model rats. Methods SD rats were divided into 3 groups： 26- month-old rats （Group A）, aging model rats induced by D-galactose （Group B） and 3-month-old rats （Group C）. The small intestinal morphological changes were observed by light microscope with HE staining in the ileum tissues, and the tight junction ultrastructure was observed under transmission electron microscope. The expression of ZO- 1 mRNA and Occludin mRNA was detected by RT-PCR assay. The expression of ZO-1 protein and Occludin protein was detected by Western blot. Results The thickness of the small intestine mucosa and villi height both in Group A and in Group B rats were lower than that in Group C. The mucosal thickness of ileum was （89.88±6.12）μm （Group A）, （87.62 ±6.32）μω （Group B） and （162.91±7.28） μm （Group C）, respectively （P〈0.05）. The villi height of ileum was （59.95 ± 4.47） μm （Group A）, （56.43±5.38） μm （Group B） and （108.12 ± 6.42）μm （Group C）, respectively （P〈0.05）. The tight junction of intestinal epithelial cells both in Group A and in Group B was looser than that in Group C, within widened gap and decreased density. The expression of ZO-1, Occludin mRNA and protein were decreased both in Group A and in Group B as compared with that in Group C. There were no significant differences in the ZO-1 and Occludin expression be- tween Group A and Group B （P〉0.05）. Conclusion The intestinal mucosal structure and epithelial barrier function in natural aging rats and in aging model rats induced by D-galactose were impaired, the changes of intestinal mucosal thickness, villi height, the tight junction structure of epithelial cells and the expression of tight junction

关 键 词：衰老 模型 动物 肠道屏障 紧密连接蛋白质类 

分 类 号：R339.38[医药卫生—人体生理学]