Effects of Rheum tanguticum polysaccharide on TNBS-induced colitis and CD4^+T cells in rats

AIM: To study the effects of Rheum tanguticum polysaccharide-1 (RTP-1) on ulcerative colitis in rats induced by 2, 4, 6-trinitrophene sulphonic acid (TNBS) and their possible mechanism.METHODS: RTP1 (200 mg@kg-1, ig) extracted from Rheum tanguticum Maxim. Ex Regel was administrated to rats with colitis induced by TNBS for 5 d, 7 d, 10 d and 14 d,respectively. The effects of RTP1 and dexamethasone (DX,0.2 mg@kg-1, ig) were contrastively investigated. The MPO level and SOD activity were determined by chromatometry.The expansion and protein expression of CD4+T lymphocytes isolated from colon mucosae and mesenteric lymph nodes of colitis rats were performed by immunohistochemical analysis and Western-blot methods.RESULTS: Treatments of RTP1 (200 mg@kg-1, ig) significantly reduced diarrhea, mortality, colon mass, ulcer areas and MPO level in colon mucosae on days 5, 7, 10 and 14 (5.2±1.4,5.4±0.7, 5.2±1.8, P＜0.05.3.4±0.8, P＜0.01. 16.1±12.1,P＜0.01.31.8±8.6, 17.7±5.3, 12.7±4.1, P＜0.05). The effectsof RTP1 were similar to those noted above in DX group, but there were no immunosupressive effects of DX in RTP-1group, such as body mass loss, thymus and spleen atrophy.The decreased number and down-regulated protein levels of CD4+T cells isolated from the colon of colitis rats treated with RTP1 were found.CONCLUSION: RTP1 shows significantly protective effects but lower side effects on rats with colitis induced by TNBS.The mechanism may be due to the resistance to over expansion of CD4.

基于蛋白质组学的支气管哮喘(巴达干赫依偏盛型)血清差异蛋白变化的机制研究

采用蛋白质组学寻找可能与支气管哮喘(bronchial asthma, BA)致病相关的关键蛋白。首先收集健康成年人与哮喘患者的血清样本,运用去除高丰度结构和非特异性蛋白质后的蛋白定量质谱(Tandem Mass TagTM,TMT),分别获得哮喘患者与健康成年人差异表达蛋白,并进行GO富集和KEGG富集分析,通过蛋白相互作用(PPI)网络分析筛选出哮喘组中的核心蛋白。然后将核心蛋白在3例支气管哮喘患者和3例健康成年人中进行蛋白印迹(Western blot)验证。通过蛋白质组学筛查共鉴定出778个差异表达蛋白,其中32个蛋白质包含定量信息(18个蛋白表达上调、14个蛋白表达下调);KEGG富集分析具有明显表达差异的信号通路有28条。PPI结果显示有10个蛋白(GDN、1433Z、VWF、HEMO、CERU、A1AT、TSP1、G3P、IBP7、KPYM)可能在支气管哮喘的发病机制中扮演重要作用。而相对于健康成年人,支气管哮喘患者血清中SLC25A4、SVEP1和KRT25蛋白表达水平升高,差异均具有统计学意义(P<0.05)。因此,推测多种免疫信号通路及差异表达蛋白在BA的发病机制中扮演了重要作用,为BA的治疗靶点研究进一步提供了方向。