摘要
目的 探究鹅去氧胆酸(chenodeoxycholic acid, CDCA)通过FXR对高脂饮食诱导小鼠肠道GLP-1表达水平的影响及相关机制。方法 C57BL/6小鼠40只分为对照组(Control组)、高脂饮食组(HFD组)、HFD+CDCA组、HFD+Z-Gug(FXR拮抗剂)组、HFD+CDCA+Z-Gug组,每组8只。干预8周,期间每周检测体质量及24 h摄食量。第8周进行口服葡萄糖耐量实验(OGTT)、腹腔葡萄糖耐量实验(IPGTT)。小鼠处死后,检测血清学指标GLu、TG、CHO、LDL-C、HDL-C;免疫荧光检测小鼠肠道组织GLP-1及FXR表达水平;RT-qPCR检测炎性因子TNF-α、IL-6、IL-1β、Gcg及FXR mRNA表达;ELISA试剂盒检测血清GLP-1含量;流式细胞术检测小肠IELs亚群比例及CD26/DPP4表达水平。结果 与Control组相比,HFD组小鼠体质量增加,血清糖脂代谢异常,口服糖耐量受损,胃肠激素分泌减弱(P<0.05);FXR mRNA及蛋白表达水平增加,Gcg mRNA表达及GLP-1分泌水平下降(P<0.05);肠道炎性因子TNF-α、IL-6、IL-1β mRNA表达水平升高(P<0.05);TCRαβ+IELs、TCRαβ+CD8αα+IELs与TCRαβ+CD8αβ+IELs细胞比例增加,TCRγδ+IELs比例下降,IELs总CD26/DPP4表达增加(P<0.05)。与HFD组相比,HFD+CDCA组小鼠体质量增加,口服糖耐量异常,胃肠激素分泌减弱(P<0.05);肠组织FXR mRNA及蛋白表达增加,Gcg mRNA表达及GLP-1分泌降低(P<0.05);肠道炎性因子表达降低,TCRαβ+IELs、TCRαβ+CD8αα+IELs与TCRαβ+CD8αβ+IELs细胞比例下降,TCRγδ+IELs占IELs比例升高,IELs总CD26/DPP4表达升高(P<0.05),以上作用在加入FXR拮抗剂Z-Gug后被明显抑制(P<0.05)。结论 CDCA可能通过激活FXR受体抑制肠道组织GLP-1表达,减少GLP-1分泌;同时可能抑制相关炎症因子表达调节IELs亚群比例,上调CD26/DPP4表达水平,促进GLP-1降解,加重胰岛素抵抗。
Objective To explore the effect of chenodeoxycholic acid(CDCA)on the expression of glucagon-like peptide-1(GLP-1)in the intestine of mice induced by high-fat diet(HFD)through farnesoid X receptor(FXR),and investigate the related mechanism.Methods Forty C57BL/6 mice were divided into control group,HFD group,HFD+CDCA group,HFD+Z-Gug(FXR antagonist)group,and HFD+CDCA+Z-Gug group,with 8 animals in each group.During intervention for 8 weeks,body weight and 24-hour food intake were measured every week.At the 8th week,oral glucose tolerance test(OGTT)and intraperitoneal glucose tolerance test(IPGTT)were conducted.After the mice were sacrificed,the serum levels of GLu,TG,CHO,LDL-C and HDL-C were detected;the expression levels of GLP-1 and FXR in intestinal tissues were detected by immunofluorescence assay;and the mRNA levels of TNF-α,IL-6,IL-1β,Gcg and FXR were detected by RT-qPCR;the serum level of GLP-1 was detected by ELISA,and the proportion of intraepithelial lymphocytes(IELs)subsets and the expression of CD26/DPP4 were detected by flow cytometry.Results Compared with the control group,the HFD group had increased body weight,abnormal serum glucose and lipid metabolism,impaired oral glucose tolerance,and weakened secretion of gastrointestinal hormones(P<0.05),enhanced FXR expression at mRNA and protein levels,declined Gcg mRNA level and GLP-1 secretion level(P<0.05),increased mRNA levels of intestinal inflammatory factors TNF-α,IL-6 and IL-1β(P<0.05),raised proportions of TCRαβ+IELs,TCRαβ+CD8αα+IELs,and TCRαβ+CD8αβ+IELs but reduced proportion of TCRγδ+IELs,and increased total CD26/DPP4 expression in IELs(P<0.05).Compared with the HFD group,HFD+CDCA treatment resulted in significantly increased body weight,impaired oral glucose tolerance,decreased secretion of gastrointestinal hormones,increased FXR mRNA and protein expression,and decreased Gcg mRNA expression and GLP-1 secretion(P<0.05);decreased proportions of TCRαβ+IELs,TCRαβ+CD8αα+IELs and TCRααβ+CD8αβ+IELs but increased proportion of TCRγδ+cells in IELs,and increased expression of total CD26/DPP4 in IELs(P<0.05),which were significantly improved after Z-Gug intervention(P<0.05).Conclusion CDCA may inhibit the expression and secretion of GLP-1 in intestinal tissue by activating FXR,and reduce the secretion of GLP-1.At the same time,CDCA may inhibit the expression of related inflammatory factors,regulate the proportions of IELs subsets,up-regulate the expression level of CD26/DPP4,promote the degradation of GLP-1 and aggravate insulin resistance.
作者
李鹏飞
蒋玲
候鹏飞
董妞
糜漫天
易龙
LI Pengfei;JIANG Ling;HOU Pengfei;DONG Niu;MI Mantian;YI Long(Research Center for Nutrition and Food Safety,Chongqing Key Laboratory of Nutrition and Health,Chongqing Medical Nutrition Research Center,Faculty of Military Preventive Medicine,Army Medical University(Third Military Medical University),Chongqing,400038,China)
出处
《陆军军医大学学报》
CAS
CSCD
北大核心
2024年第9期952-961,共10页
Journal of Army Medical University
基金
国家自然科学基金面上项目(82173505)。
关键词
鹅去氧胆酸
GLP-1
FXR
IELs
CD26
chenodeoxycholic acid
glucagon-like peptide-1
farnesoid X receptor
intraepithelial lymphocytes
CD26
