姜黄素干预JAK/STAT/SOCS信号通路对溃疡性结肠炎大鼠树突状细胞功能紊乱的调控作用

It is an effective and reliable pathway to regulate activation and function of dendritic cell (DC) by JAK/STAT/SOCS signal, and an important treated tactics of autoimmune disease including ulcerative colitis (UC) treated by DC. However, clinical studies had shown Curcumin effectively and securely treated UC, but its mechanism is not sufficiently clear to regulate DC. The study will evaluate therapeutic effect of Curcumin by score of pathological injuries after Curcumin was administrated rats with UC. From these respects as subgroup, phenotype, function, costimulatory molecules, and so on, while Curcumin will be investigated to regulate functional disorder of DC separated from peripheral blood and mesocolic lymph nodes of UC rats by flow cytometry, Western blot analyze, ELISA and immunohistochemistry. Furthermore, the critical proteins expressed on DC in JAK/STAT/SOCS signal pathway were analyzed to explore target point and mechanism of Curcumin which could regulate function of DC from UC rats on JAK/STAT/SOCS signal pathway correlated with differentiation, maturation and activation of DC.

JAK/STAT/SOCS信号作为调控树突状细胞（DC）活化及功能的有效途径已为众人公认，而且以DC为靶点已成为治疗包括溃疡性结肠炎(UC)等在内的自身免疫性疾病的重要策略之一。尽管临床研究表明姜黄素治疗UC安全有效，但其能否调节DC功能以治疗UC的作用机制及途径不明。本课题拟通过复制UC大鼠模型，姜黄素干预后，采用病理性损伤评分评价姜黄素治疗大鼠UC疗效，同时分离外周血及结肠系膜淋巴结中的DC，并采用Western blot 分析等方法，从DC的亚群、表型、功能、表面共刺激分子表达，外周血Th17/Treg水平和刺激淋巴细胞增殖等多个角度，全面地考察姜黄素对UC大鼠DC功能紊乱的调控作用。同时从涉及DC分化、成熟、活化的JAK/STAT/SOCS信号出发，分析JAK/STAT/SOCS信号上关键性蛋白在DC的表达水平，探索姜黄素调控UC大鼠DC功能的可能作用机制及作用靶点。

树突状细胞在炎症性肠病的发病过程中发挥了重要作用，且受JAK/STAT/SOCS信号调节。作为抗炎的有效组分，姜黄素是治疗慢性炎症性肠病的可行替代品和治疗辅助品。我们发现通过复制溃疡性结肠炎大鼠模型，姜黄素灌胃治疗7天后，结肠炎小鼠体重，结肠重量，结肠重量指数明显下降，结肠长度延长，同时组织学评价可见病理症状和组织进行性修复，粘膜层及粘膜下层炎细胞浸润，溃疡数量下降，充血，水肿程度明显减轻，镜下病理损伤评分明显下降。提示姜黄素可有效治疗实验性结肠炎，同时树突状细胞表面的共刺激分子，如 MHC-II CD83, CD28, B7-DC, CD40, CD40 L and TLR2 明显被抑制，且IL-4, IL-10 and IFN-γ表达上调, 而 GM-CSF, IL-12p70, IL-15, IL-23 and TGF-β1水平下降. 进而JAK2, STAT3 and STAT6 蛋白活化被抑制, 然而其下游SOCS1, SOCS3 and PIAS3则高表达 。Treg cells数量明显升高，并伴有TNF-α, IL-2, IL-6, IL-12 p40, IL-17 和 IL-21, 及 树突状细胞表面共刺激分子CD205, CD54 [ICAM-1], TLR4, CD252 [OX40 L], CD256 [RANK] 和CD254 [RANK L])。同时在脾脏和PP结CD8 + CD11c + cells总数明显下降，伴有MHC II, CD205, CD40, CD40L 和ICAM-1 表达被抑制, IL-10, IFN-γ和 TGF-β1 水平被升高等现象。所有结果表明，姜黄素有效治疗实验性结肠炎，可能是通过调节JAK/STAT/SOCS 信号抑制DCs活性恢复免疫平衡而实现的。