绣球菌多糖对免疫低下小鼠盲肠短链脂肪酸、G蛋白偶联受体及免疫因子的调节

Regulation of Sparassis Latifolia Polysaccharide on Short Chains Fatty Acids,G Protein-Coupled Receptors and Immune Factors in Cecum of Immunocompromised Mice

为探究广叶绣球菌多糖对免疫低下小鼠盲肠中短链脂肪酸、G蛋白偶联受体及免疫因子的调节作用,用腹腔注射环磷酰胺构建免疫低下小鼠模型,将小鼠分为6组:正常对照组,模型组,广叶绣球菌多糖低、中、高剂量组以及阳性对照组。连续饲养30 d后处死取样,检测免疫器官指数,高效液相色谱(HPLC)技术分析盲肠内容物短链脂肪酸(SCFAs)的含量,实时荧光定量PCR(qRTPCR)及蛋白免疫印迹技术(Western blot)分析小肠中下游相关因子的基因表达与G蛋白偶联受体蛋白的表达,分析SCFAs与GPCR蛋白表达的相关性。结果表明:广叶绣球菌多糖中、高剂量组均可显著提高3种短链脂肪酸的含量(P<0.05或P<0.01),绣球菌多糖高剂量组GPR41、GPR43、GPR109A、FOXP-3、IL-6、IL-8和L-10的mRNA表达水平与GPR41、GPR43和GPR109A蛋白表达量均显著增加(P<0.01),SCFAs与GPCR蛋白的表达显著相关。广叶绣球菌多糖可通过提高免疫低下小鼠盲肠内乙酸、丙酸和丁酸含量,诱导GPR41、GPR43和GPR109A表达,上调FOXP-3、IL-6、IL-8和L-10的mRNA表达,参与调节小鼠肠道的免疫反应,发挥抗炎作用。

In order to study the regulatory mechanism of Sparassis latifolia polysaccharide(SLP)on intestinal immune function in immunosuppressed mice.The immunosuppressive mice model was established by intraperitoneal injection of cyclophosphamide.The mice were randomly divided into 6 groups:normal control group,model group,low,medium and high dose SLP group,and positive group.The continous feeding lasted for 30 days.The immune organ index was detected,the content of short chain fatty acids(SCFAs)in cecal were analyzed by HPLC.Fluorescence quantitative RT-PCR was used to detect the expression of GPR41,GPR43,GPR109A,FOXP-3,IL-6,IL-8 and L-10 gene mRNA in the small intestine.Western blot was used to detect the protein expression of GPR41,GPR43 and GPR109A in the small intestine.The correlation between SCFAs and GPCR protein expression was analyzed.The results showed that,the content of three main short chain fatty acids in cecum of high and medium dose group were significantly increased(P<0.05 or P<0.01);the high dose of SLP can significantly improve the relative expression level of GPR41,GPR43,GPR109A,FOXP-3,IL-6,IL-8,L-10 mRNA(P<0.01)and improve the protein expression of GPR41,GPR43 and GPR109A in the small intestine(P<0.01).SLP can effectively regulate the intestinal immune function of immunosuppressed mice by promoting the content of short chain fatty acids,increasing the relative expression level of GPR41,GPR43,GPR109A,FOXP-3,IL-6,IL-8,L-10 mRNA,to participate in the body’s immune response and act as anti-inflammatory.