姜黄素干预BCL-6/Blimp-1信号调控Tfh细胞分化治疗溃疡性结肠炎的分子机制研究

In the recent years，abnormal differentiation of follicular helper T cells (Tfh) resulted in inflammatory bowel disease (IBD) is a research hotspot, while BCL-6/Blimp-1 signaling pathway and its epigenetics factors change are the determining factor of Tfh differentiation. And these are critical factors in pathogenesis of ulcerative colitis. All evidences had hinted that it is an effective therapeutic strategy treated IBD via regulating Tfh differentiation by BCL-6/Blimp-1 signaling pathway. In our previous NSFC project, we found that Curcumin (Cur) effectively treated experimental colitis, which was realized by inhibiting Dendritic Cells via repressing JAK/STAT/SOCS to restore immunologic balance, and Cur obviously inhibited expressions of key upstream proteins of BCL-6/Blimp-1 signaling pathway. Our results indicated that Cur have potential functions on regulation of Tfh differentiation and BCL-6/Blimp-1 signaling pathway. So, we proposed scientific hypothesis that Cur effectively treated UC by regulating BCL-6/Blimp-1 pathway to control Tfh differentiation. In the present project, we will verify the effect of Cur treated experimental colitis, and evaluate levels of Tfh types, Tfh subpopulation and memory of Tfh. While we will analyze expressions of core index, positive and negative regulation of BCL-6/Blimp-1 pathway, and observe its epigenetics factors change on histone modification and miRNA. It it to explore mechanism of Cur treated UC via BCL-6/Blimp-1 pathway to regulate Tfh differentiation, and to expand the category of Cur’s immunophamacology.

BCL-6/Blimp-1信号及其表观遗传学因素改变是滤泡辅助性T细胞 (Tfh) 分化的决定性因素，是溃疡性结肠炎(UC)发病的关键因素之一，也是其药物作用机制研究热点，提示干预BCL-6/Blimp-1信号调控Tfh分化可能是治疗UC的的有效策略之一。我们前一个国家基金表明，姜黄素(Cur)有效治疗UC是通过抑制DCs活性恢复免疫平衡实现的，且明显抑制该信号上关键蛋白表达，提示Cur具有调控Tfh分化和BCL-6/Blimp-1信号潜在可能。故我们提出Cur可能通过干预该信号调控Tfh分化治疗UC的科学假设。我们再次验证Cur治疗UC有效性，并评价Tfh分型、Tfh亚群及记忆性Tfh水平，并分析BCL-6/Blimp-1信号上核心指标、正性调控和负性调控因素的表达，继而考察该信号表观遗传学因素的改变，从干预BCL-6/Blimp-1信号调控Tfh分化全面探索Cur治疗UC的作用机制。

BCL-6/Blimp-1信号及其表观遗传学因素改变是滤泡辅助性T细胞 (Tfh) 分化的决定性因素，是溃疡性结肠炎(UC)发病的关键因素之一，也是其药物作用机制研究热点，提示干预BCL-6/Blimp-1信号调控Tfh分化可能是治疗UC的的有效策略之一。 在本课题中，我们采用DSS诱导的结肠炎小鼠，经姜黄素给药治疗后，发现结肠重量指数、镜下病理损伤评分明显降低，结肠粘膜病理性损伤缓解、降低 IL-1β、IL-2、IL-6、IL-9、IL-17A、IL-7、IL-15、IL-21、IL-23、IL-12、TGF-β1表达等，同时其中枢性记忆性Tfh细胞水平显著升高，同时性效应性记忆性Tfh细胞水平显著下降，且BCL-6+Tfh细胞、PD-1+Tfh细胞、PD-L1+Tfh细胞、ICOS+Tfh细胞等细胞水平明显下降，同时Blimp-1+Tfh细胞水平则显著升高，而且IFN-γ+Tfh细胞、IL-10+Tfh细胞、IL-21+Tfh细胞、Foxp3+Tfh细胞水平显著升高，同时IL-17A+Tfh细胞水平明显下降，表明姜黄素治疗DSS诱导的小鼠实验性结肠炎可能是通过调节其Tfh细胞平衡来实现的。同时BCL-6，p-STAT3，FOXO1，Foxp1，Roqunin-1，Roqunin-2，SAP的表达水平明显下降，但Blimp-1，STAT3蛋白的表达水平明显升高，同时BCL-6 mRAN, TSC1 mRAN, Ncor1 mRAN, MTA3 mRAN, SMRT mRAN, AP-1 mRAN, BAZF mRAN等相关基因的表达明显下降，同时Ncor2 mRAN, MIZ1 mRAN, H4K3me3 mRNA, Bcor2 mRAN等表达明显增加，提示姜黄素可通过调控影响DSS诱导的结肠炎小鼠结肠黏膜中BCL-6/Blimp-1信号活化的表观遗传学相关基因的表达从而抑制BCL-6/Blimp-1信号活化，进一步提示姜黄素可能通过调控BCL-6/Blimp-1信号活化的表观遗传学相关基因的表达进而抑制BCL-6/Blimp-1信号活化而调节Tfh细胞分化而有效治疗溃疡性结肠炎。