芳香烃受体调控人脂肪间充质干细胞的免疫调节功能

AHR regulates the immunomodulatory function of human adipose-derived mesenchymal stem cells

目的探索芳香烃受体(AHR)对人脂肪间充质干细胞(MSCs)免疫调节功能的影响。方法RT-qPCR和免疫荧光染色法检测炎性细胞因子刺激前后,MSCs中吲哚胺2,3-双加氧酶1(IDO1)、白细胞介素-4诱导基因1(IL4I1)和芳香烃受体表达水平;将si-Ctrl、si-IDO1、si-IL4I1、si-AHR转染至MSCs,阻断AHR信号通路;将MSCs的条件培养基与巨噬细胞共培养,RT-qPCR和ELISA检测巨噬细胞炎性因子IL-6、IL-1β、TNF-α水平。结果未经细胞因子刺激的MSCs高表达AHR,几乎不表达IDO和IL4I1蛋白;不同细胞因子刺激后,代谢酶IDO1、IL4I1及AHR表达上调(P<0.05),IFN-γ刺激后IDO1、IL4I1表达上调最为显著(P<0.001),进入细胞核的AHR增多;下调AHR的表达削弱MSCs的免疫抑制作用(P<0.05)。结论AHR参与调节MSCs的免疫功能,下调AHR可以抑制MSCs的免疫调节作用。

Objective To explore the effect of aryl hydrocarbon receptor(AHR)on the immunomodulatory function of human adipose derived mesenchymal stem cells(MSCs).Methods RT-qPCR and immunofluorescence staining were used to detect the expression levels of indoleamine 2,3-dioxygenase 1(IDO1),interleukin-4-inducible gene 1(IL4I1)and AHR in MSCs before and after inflammatory cytokine stimulation;siCtrl,siIDO1,siIL4I1 and siAHR were transfected into MSCs and blocked the AHR signaling pathway;conditioned medium from MSCs was co-incubated with macrophages,RT-qPCR and ELISA were performed to detect the level of IL-6,IL-1β,TNF-α.Results MSCs without cytokine stimulation highly expressed AHR and hardly expressed IDO1 and IL4I1 proteins;IDO1,IL4I1 and AHR were up-regulated after different cytokine stimulation(P<0.05),the expression of IDO1 and IL4I1 was most significantly up-regulated after stimulation by IFN-γ(P<0.001),AHR entering the nucleus was increased;down-regulation of AHR expression could inhibit the immunomodulatory effect of MSCs(P<0.05).Conclusions AHR regulates the immune function of MSCs,downregulates expression of AHR could inhibit the immunomodulatory effects of MSCs.