青藤碱通过调控肠道菌群与色氨酸代谢激活芳香烃受体改善类风湿性关节炎

Sinomenine ameliorates rheumatoid arthritis by modulating tryptophan metabolism and activating aryl hydrocarbon receptor via gut microbiota regulation

肠道菌群失调与类风湿关节炎(RA)的发生发展密切相关.青藤碱(sinomenine,SIN)是临床上有效用于治疗RA的中药制剂,但SIN如何调节肠道菌群缓解RA仍有待研究.为了确定与SIN改善类风湿关节炎作用相关的关键肠道微生物和差异代谢物,本研究通过16S rRNA基因测序、抗生素干预和粪菌移植实验,评估SIN抗RA作用是否依赖于肠道菌群.然后,通过代谢组学分析、转录组学分析和单菌/差异代谢物体内给药验证,寻找SIN调控肠道菌群以降低RA严重程度的关键菌群、代谢物和作用靶点.实验结果表明:SIN主要通过升高Lactobacillus属丰度改善肠道菌群失调,进而显著缓解胶原诱导的类风湿性关节炎(CIA)症状.同时,SIN可显著提高肠道微生物来源的色氨酸代谢产物吲哚-3-丙烯酸、吲哚-3-丙酸和吲哚-3-乙酸水平.体内、外色氨酸代谢产物给药实验得出,色氨酸代谢产物可通过激活芳香烃受体(AhR),改善Th17/Treg平衡缓解CIA大鼠的关节炎症和免疫反应.最后,L.paracasei和L.case单菌体内定植实验证实,SIN可通过富集L.paracasei和L.case缓解RA症状.综上,SIN通过调控肠道菌群特别是乳酸杆菌属L.paracasei和L.case丰度影响微生物源的色氨酸代谢产物水平来激活AhR协同治疗RA.

Gut microbiota dysbiosis is associated with the development of rheumatoid arthritis(RA).Sinomenine(SIN)is an effective immunosuppressive and anti-inflammatory drug used for treating RA,but how SIN regulates gut microbiota to alleviate RA remains underexplored.To identify the critical gut microbial species and microbial metabolites associated with the RA-protective effects of SIN,the microbiotadependent anti-RA effects of SIN were assessed by 16S rRNA gene sequencing,antibiotic treatment,and fecal microbiota transplantation.Metabolomics analysis,transcriptional analysis,and targeted bacteria/metabolites gavage were conducted to explore how SIN regulates gut microbiota to reduce the severity of RA.SIN could restore intestinal microbial balance by mainly modulating the abundance of Lactobacillus,and significantly relieve collagen-induced arthritis(CIA)symptoms in a gut microbiotadependent manner.SIN significantly elevated microbial tryptophan metabolites indole-3-acrylic acid(IA),indole-3-propionic acid(IPA),and indole-3-acetic acid(IAA).Tryptopha n metabolites supplementation could activate aryl hydrocarbon receptor(AhR)and regulate Th17/Treg balance in CIA rats.Intriguingly,SIN relieved the arthritis symptoms involving the enrichment of two beneficial anti-CIA Lactobacillus species,L.paracasei and L.casei by mono-colonization.The promising therapeutic function of SIN was mostly attributed to the activation of AhR by explicitly targeting the Lactobacillus and microbial tryptophan metabolites.The intestinal bacterium L.paracasei and L.casei may be used to reduce the severity of CIA.