Oxymatrine Protects Against UC Through PI3K/AKT Signaling Pathway And BMSC-EVs Regulate Th17 Cells Differentiation In UC Via H3K27me3

Part I: Oxymatrine improves UC by inhibiting PI3K/AKT signaling pathwayObjective: To study the effect of Oxymatrine,the main active component of Sophora flavescens,on the improvement of UC and its mechanism of action.Methods: A mouse model of DSS-induced colitis was established.Mice were treated respectively with high,medium,and low doses(200,100,50 mg/kg)of oxymatrine and the disease activity index and colon pathology were assessed.The efficacy of Oxymatrine efficacy was observed through these factors.At the same time,in order to further explore the mechanism of Oxymatrine in the treatment of UC,we studied the PI3K/AKT signaling pathway and LY294002,a classical PI3K/AKT pathway inhibitor,was used as a positive control.We explored the function of Oxymatrine on this pathway and its effect on apoptosis-related proteins,inflammatory mediators and immune cells downstream of PI3K/AKT pathway.Results: 1.Oxymatrine can significantly improve UC mice's body weight and the shortened colon length,reduce the DAI score and histological score,relieve colon inflammation,gland destruction and mucosal tissue damage.2.Oxymatrine can inhibit the expression of anti-apoptotic proteins NF-?Bp65 and Bcl-2 downstream of PI3K/AKT and promote the pro-apoptotic effects of the pro-apoptotic proteins Bad,cleaved-caspase9 and cleaved-caspase3.And the differences are statistically significant(P<0.05).3.Oxymatrine can significantly inhibit the expression of inflammatory cytokines TNF-?,IL-6,IL-1? and helper T cells Th1,Th17 downstream of PI3K/AKT pathway.The differences are statistically significant(P<0.05).4.The effect of oxymatrine on the expression of total AKT protein in each group is not statistically different,but it could significantly reduce the expression of phosphorylated AKT protein and the difference is statistically significant(P<0.05).Conclusion: Oxymatrine can improve UC via inhibiting the PI3K/AKT signaling pathway by exerting anti-inflammatory,pro-apoptotic and immune-modulating effects.Part II : BMSC-EVs regulate Th17 cells differentiation in UC via H3K27me3Objective: To study the effect of BMSC-EVs on the differentiation of Th17 cells in UC rats and its epigenetic mechanism.Methods: A rat model of TNBS-induced colitis was established.Rat BMSCs were cultured and BMSC-EVs were obtained by gradient centrifugation.The model rats were injected by tail vein with high,medium and low doses(200,100,50?g/kg)of BMSC-EVs.The effect of BMSC-EVs on UC and differentiation of UC Th17 cells were observed though evaluating the improvement of inflammation in rat colon tissue and measuring the proportion of Th17 cells in the spleen and lymph nodes of rats.Meanwhile,in order to investigate the mechanism of BMSC-EVs on regulating UC Th17 cells differentiation,we used the epigenetic histone H3K27me3 as a new target.We detected the expression levels of H3K27me3 in colon tissues and its methyltransferases(SUZ12,EZH1,EZH2,EED)and demethylases(Jmjd3,UTX).Results: 1.BMSC-EVs can improve UC rats body weight,colon length and weight,and reduce DAI score and inflammatory lesions.2.BMSC-EVs can inhibit the ratio of Th17 cells in lymph nodes and spleen of UC rats,and can also inhibit the expression of Th17 cell transcription factors ROR?t,STAT3 and cytokines IL-17 A,IL-21 and IL-22.The differences are statistically significant(P<0.05).3.BMSC-EVs can increase the expression of H3K27me3 and H3K27me3 methyltransferases SUZ12,EZH1,EZH2,and EED in UC,and decrease the expression of demethylases Jmjd3 and UTX,and the differences are statistically significant(P<0.05).Conclusion: BMSC-EVs may inhibit the differentiation of UC Th17 cells by regulating H3K27me3.