Department of Anatomy, Taipei Medical University, Taipei, Taiwan, ROC.
School of Medical Laboratory Science and Biotechnology, Taipei Medical University, Taipei, Taiwan, ROC.
Br J Nutr. 2014 Mar 28;111(6):1032-9. doi: 10.1017/S0007114513003425. Epub 2013 Nov 14.
The present study investigated the effect of glutamine (Gln) on dextran sulphate sodium (DSS)-induced changes in the expression of small-intestinal intraepithelial lymphocyte (IEL) γδ-T cells in mice. Mice were randomly assigned to a normal control (NC) group and two DSS-treated groups. The NC group and one of the DSS-treated groups (DSS-C) were fed a common semi-purified diet, while the other DSS-treated group (DSS-G) was fed an identical diet, except that part of casein was replaced by Gln, which provided 25 % of total amino acid nitrogen. After being fed the diets for 10 d, mice in the NC group were given distilled water, while the DSS-treated groups were given distilled water containing 2·5 % DSS for 5 d. At the end of the experiment, the mice were killed. The small-intestinal IEL γδ-T-cell subset was isolated for further analysis. The results indicated that DSS treatment resulted in a lower percentage of small-intestinal IEL γδ-T cells and higher mRNA expressions of interferon-γ, TNF-α, IL-17, complement 5a receptor and keratinocyte growth factor in IEL γδ-T cells. Gln administration increased the proportion of small-intestinal IEL γδ-T cells, and the expression levels of immunomodulatory mediator genes in IEL γδ-T cells were lower in the DSS-treated mice. The histological findings indicated that the immunoreactive intensity of the tight junction protein ZO-1 in the small-intestinal mucosa was higher in the DSS-G group than in the DSS-C group. These results indicate that pretreatment with Gln increases the proportion of small-intestinal IEL γδ-T cells and down-regulates γδ-T-cell-expressed inflammatory mediators, which may consequently ameliorate the severity of DSS-induced small-intestinal epithelial injury.
本研究探讨了谷氨酰胺（Gln）对葡聚糖硫酸钠（DSS）诱导的小鼠小肠上皮内淋巴细胞（IEL）γδ-T 细胞表达变化的影响。将小鼠随机分为正常对照组（NC）和两组 DSS 处理组。NC 组和 DSS 处理组之一（DSS-C）喂食普通半纯化饮食，而另一个 DSS 处理组（DSS-G）喂食相同的饮食，只是部分酪蛋白被 Gln 取代，提供总氨基酸氮的 25%。喂食饮食 10 天后，NC 组的小鼠给予蒸馏水，而 DSS 处理组给予含有 2.5% DSS 的蒸馏水 5 天。实验结束时，处死小鼠。分离小肠 IEL γδ-T 细胞亚群进行进一步分析。结果表明，DSS 处理导致小肠 IEL γδ-T 细胞比例降低，IEL γδ-T 细胞中干扰素-γ、TNF-α、IL-17、补体 5a 受体和角质形成细胞生长因子的 mRNA 表达升高。Gln 给药增加了小肠 IEL γδ-T 细胞的比例，DSS 处理小鼠 IEL γδ-T 细胞中免疫调节介质基因的表达水平较低。组织学发现 DSS-G 组小肠黏膜紧密连接蛋白 ZO-1 的免疫反应强度高于 DSS-C 组。这些结果表明，Gln 预处理可增加小肠 IEL γδ-T 细胞的比例，并下调 γδ-T 细胞表达的炎症介质，从而可能改善 DSS 诱导的小肠上皮损伤的严重程度。
