Syndecan-1在小鼠结肠炎模型中的表达和意义

Expression and Significance of Syndecan-1 in Mice Colitis Model

背景:Syndecan-1是一种由硫酸乙酰肝素链和硫酸软骨素链修饰的Ⅰ型跨膜蛋白,主要表达于上皮细胞和内皮细胞,与炎症发生的各个环节均有密切联系。目的:观察结肠炎模型小鼠结肠组织中Syndecan-1的表达,探讨其在炎症性肠病(IBD)中的作用。方法:以三硝基苯磺酸(TNBS)-乙醇溶液灌肠诱导小鼠结肠炎模型。于造模后3、7、14、21d分批处死各组小鼠,于光学显微镜下观察结肠组织学改变并评分;分别以逆转录聚合酶链反应(RT-PCR)和免疫组化方法检测结肠组织Syndecan-1mRNA和蛋白水平的表达。结果:各模型组结肠组织学评分均显著高于正常对照组(P<0.01),以造模后第3d最高,其后逐渐减低。各模型组结肠组织Syndecan-1mRNA表达水平与正常对照组相比差异无统计学意义,但蛋白表达评分均显著低于正常对照组(P<0.01),以造模后第3d最低,其后逐渐回升。结论:结肠组织Syndecan-1蛋白表达与模型小鼠结肠炎病变严重程度有关,有可能成为IBD诊治和病情监测的指标之一。

Background： Syndecan-1 is a type Ⅰ transmembrane protein modified by heparan sulfate and chondroitic acid. It is mainly expressed on the surface of epithelial cells and endothelial cells, and has close correlation with the progress of inflammatory reaction. Aims： To explore the expression of syndeean-1 in the colonic tissues of mice colitis model, and to investigate the role of syndecan-1 in inflammatory bowel disease （IBD）. Methods： Trinitrobenzenesulfonic acid （TNBS）- ethanol solution was administered rectally to construct colitis model in mice. The animals were sacrificed on the 3rd, 7th, 14th and 21st day, respectively after model construction. Then the colonic histologic changes were observed and scored by light microscopy, and the expression of syndecan-1 in colonic tissues at mRNA and protein levels was determined by reverse transcriptase polymerase chain reaction （RT-PCR） and immunohistochemistry, respectively. Results： The histologic score in colitis model groups was significantly higher than that in the normal controls （P〈0.01）, the highest score occurred on the 3rd day after model construction, and then decreased gradually. The expression of colonic syndeean-1 protein in model groups was significantly lower than that in the normal controls （P〈0.01）, but not the expression of syndecan-1 mRNA, which was not significantly different from that in the normal controls. The syndecan-1 protein expression was the least on the 3rd day after model construction, and then increased gradually. Conclusions： The colonic expression of syndecan-1 protein in colitis model mice is correlated with the severity of colitis. Syndecan-1 might be used as a marker for the diagnosis, treatment and disease monitoring of IBD.