樟芝多糖通过调节肠黏膜浸润的Th9及IL-9的表达调控小鼠慢性结肠炎的机制研究

Mechanism Study on Antrodia Camphorata Polysaccharide Regulate Mouse Chronic Colitis via Intestinal Mucosal Infiltration of Th9 and Its Cell Factor IL-9

目的研究樟芝多糖调节结肠黏膜浸润的Th9及其细胞因子IL-9的表达,从而减轻小鼠慢性结肠炎的机制。方法利用葡聚糖硫酸钠(dextran sulfate sodium,DSS)构建小鼠慢性结肠炎模型,设置正常组、模型组、阳性对照组(抗IL-9抗体注射组)以及樟芝多糖组(20 mg·kg^(-1))。DAI评分综合评价小鼠1个月内活动能力,测定小鼠1个月内的体质量变化,流式细胞术检测外周血、结肠黏膜固有层中单个核细胞中CD4+IL-9+T细胞的比例,ELISA法检测外周血及结肠黏膜中IL-9、TGF-β以及IL-4的表达,实时荧光定量PCR检测小鼠结肠黏膜中IL-9、TGF-β、smad3及IL-4的表达,HE染色观察小鼠结肠组织病理。结果 DSS可以引起小鼠慢性结肠炎性病变,DAI评分结果显示模型组小鼠活动能力明显下降,而樟芝多糖干预后DAI评分显著降低(P<0.05),模型组小鼠外周血及结肠黏膜固有层中Th9比例相比正常组显著增高(P<0.05),外周血及结肠黏膜中IL-9、TGF-β及IL-4的蛋白及mRNA表达也显著增高(P<0.05)。阳性对照组及樟芝多糖组小鼠外周血及结肠黏膜固有层中Th9比例相比模型组显著下调(P<0.05),且外周血及结肠黏膜中IL-9,TGF-β以及IL-4的蛋白及mRNA表达也显著下调(P<0.05),HE染色结肠病理情况明显好转。结论樟芝多糖可以通过调节Th9比例和IL-9表达改善小鼠慢性结肠炎,其作用与免疫调节及抗炎作用有关。

OBJECTIVE To study the mechanism of Antrodia camphorata polysaccharide regulate mouse chronic colitis via intestinal mucosal infiltration of Th9 and its cell factor IL-9. METHODS The chronic colitis model was established by dextran sulfate sodium（DSS）. Set the normal group, the model group, the positive control group（anti IL-9 antibody injection group）, the Antrodia camphorata polysaccharide group（20 mg·kg^-1 Antrodia camphorata polysaccharide）. Activity in mice within one month was comprehensive evaluated by DAI score. Body weight changes of mice in one month were detected. Flow cytometry was used to detect the proportion of CD4＋IL-9＋T cells in the mononuclear cells of the peripheral blood and intestinal mucosa. The expression of IL-9, TGF-β and IL-4 in peripheral blood and intestinal mucosa were detected by ELISA. IL-9, TGF-β, Smad3 and IL-4 expression in mouse mucosa were detected by real-time quantitative PCR. HE staining was used to observe the pathological changes of colon tissue in mice. RESULTS DSS could induce chronic colitis in mice, DAI results showed that the activity of mice in the model group decreased significantly and therer is a significant decreased in DAI score in the prognosis of polysaccharides（P〈0.05）. The ratio of Th9 in the peripheral blood and intestinal lamina propria of model mice was significantly higher than that in the normal group（P〈0.05）. The expressions of IL-9, TGF-β, IL-4 protein and m RNA in peripheral blood and intestinal mucosa were also increased significantly（P〈0.05）. In the positive control group and the Antrodia camphorata polysaccharide group, the ratio of Th9 in the peripheral blood and intestinal lamina propria was lower than that in the model group after intervention（P〈0.05）. The expressions of IL-9 TGF-β, IL-4 protein and m RNA in peripheral blood and intestinal mucosa were also declined significantly（P〈0.05）. The pathological changes of colon were obviously improved by HE staining. CONCLUSION Antrodia camphorata polysaccharide can improve chronic colitis in mice via intestinal mucosal infiltration of Th9 and its cell factor IL-9. The mechanism is related to immune regulation and anti-inflammatory reaction