长期低蛋白饮食对中老年小鼠非特异性炎症反应和脾脏T细胞的影响  

The influence of long-term low-protein intake on nonspecific inflammatory responses and spleen T lymphocytes in middle-aged and older mice

作　　者：王郝莹 张丽君 张琼 郭建红 

机构地区：[1]山西医科大学基础医学院病理生理学教研室,太原030001

出　　处：《中华老年医学杂志》2018年第2期215-219,共5页Chinese Journal of Geriatrics

基　　金：山西省自然科学基金（2013011054-2）

摘　　要：目的探讨长期低蛋白饮食对中老年小鼠肝脏非特异性炎症反应和脾脏T淋巴细胞的影响及相关机制。方法14月龄雌性昆明小鼠数字抽签随机分为对照组、低蛋白组、高蛋白组、高蛋白＋西罗莫司组，另设2月龄雌性昆明小鼠为成年组，分别给予标准基础饲料或自配特殊饲料，高蛋白＋西罗莫司组隔日腹腔注射西罗莫司。于实验3个月末处死小鼠，制备肝脏切片观察肝脏病理改变、检测CD68和mTOR蛋白表达；制备脾脏淋巴细胞悬液，通过流式细胞学检测脾脏CD4^＋T、CD8^＋T细胞百分比。结果肝组织切片低蛋白组和高蛋白＋西罗莫司组与对照组比较，肝细胞排列整齐、肝窦无明显扩张，时间相关性改变减轻；给予中老年小鼠低蛋白饮食或高蛋白饮食＋西罗莫司，其肝脏CD68表达低于对照组（P〈0．05），脾脏CD4^＋T、CD8^＋T细胞数均高于对照组（P〈0．05）；肝脏mTOR蛋白在低蛋白组和高蛋白＋西罗莫司组的表达均低于对照组（P〈0．05）；而高蛋白组与以上结果相反。结论长期给予低蛋白饮食有利于延缓脾脏T淋巴细胞的衰减，改善肝脏时间相关性结构及非特异性炎症改变，其机制可能与下调mTOR蛋白的表达相关。Objective To explore the effects of long-term low-protein intake on nonspecific inflammatory responses in the liver and T lymphocytes in the spleen in middle-aged and older mice and underlying mechanisms. Methods Fourteen month-old female KM（Kunming）mice were randomly divided into the control group, the low-protein group, the high-protein group and the high-protein ＋ rapamycin group. Additionally, Two month-old female KM mice served as the adult group and were fed regular chow. Animals in the high-protein ＋ rapamycin group received injections of rapamycin intraperitoneally once every two days. Animals were sacrificed at the end of 3 months. Liver histology slices were prepared for the examination of pathological changes and detection of the expression of CD68 and mTOR（the mechanistic target of rapamycin）. Spleen lymphocyte suspensions were prepared to count the percentages of CD4^＋ T and CD8^＋ T cells. Results Compared with the control group,the low-protein group and the high-protein ＋ rapamycin group in histology slides showed regularly arranged hepatocytes, no obvious sinus hepaticus expansion and only mild time-related changes. Moreover,compared with the control group, the low-protein and high-protein ＋ rapamycin groups were associated with increased percentages of CD4^＋ T and CD8^＋ T cells in the spleen（all P〈 0.05）and decreased expression of CD68 in the liver（P〈0.05）, though the levels of roTOR were similar among the groups. Conclusions Long-term low-protein intake has beneficial effects in mitigating the reduction of T lymphocytes in the spleen and slowing age-related structural and nonspecific inflammatory changes in the liver, possibly through downregulation of the expression of the mTOR protein.

关 键 词：衰老 膳食 限制蛋白质 T淋巴细胞 

分 类 号：R363[医药卫生—病理学]