PKD2通过JAK-STAT途径调控巨噬细胞迁移与极化及其在IBD中的作用机制研究

巨噬细胞的募集及极化失衡是炎症性肠病的关键病理因素，其机制尚不清楚。蛋白激酶D2（PKD2）是新近发现的钙离子依赖性激酶，申请人前期工作发现PKD2在IBD外周血单个核细胞及肠粘膜中低表达，并通过调节粘膜免疫而调控IBD的进展，可作为IBD治疗的新靶点。最新的研究表明JAK-STAT信号通路参与巨噬细胞的极化，结合我们前期PKD2酶活性缺陷转基因小鼠mRNA测序结果，我们推测其可能与PKD2调控IBD相关。本课题拟在前期基础上: 1.利用功能获得与缺失实验，在细胞水平和转基因动物水平分析PKD2对IBD中巨噬细胞的迁移与极化的影响，并检测其与JAK-STAT的关系；2.进一步探讨PKD2调控JAK-STAT信号通路参与巨噬细胞迁移与极化的机制。通过上述体内、体外实验的结合，探讨PKD2作为IBD干预靶点调控巨噬细胞极化的可能性，为IBD的治疗奠定理论基础。

Migration and polarization imbalance of macrophages remains the major pathological cause of IBD. However, the underlying mechanism is poorly understood. Protein kinase d2 (PKD2) is a newly discovered calcium/calmodulin-dependent kinase, and we firstly reported that expression of PKD2 in PBMCs and colonic biopsies with IBD was markedly decreased compared with normal controls. Moreover, PKD2 catalytic activity deficiency mice exacerbated increased susceptibility to DSS-induced colitis by modulating immunological responses, which implies that PKD2 might be a new target in IBD therapy. It has been recently reported that JAK-STAT pathway is closely associated with the polarization imbalance of macrophages in IBD and based on our previous studies of RNA sequencing of PKD2 catalytic activity deficient mice, we supposed that PKD2 might modulate JAK-STAT pathway to control the development of IBD. So some tests were designed as follows: firstly, to explore the effect of PKD2 on macrophages migration and polarization in vitro and in vivo via gain or loss of function of PKD2, as well as to evaluate whether the role of PKD2 is correlated with JAK-STAT pathway; secondly, to determine the mechanism of PKD2 and JAK-STAT pathway involved in macrophages migration and polarization. Our results will provide a theoretical foundation for deepening the understanding of the pathogenesis of PKD2 in macrophages function and exploring new therapeutic targets for IBD.