G6PI介导Rho信号促进RA成纤维样滑膜细胞迁移与侵袭作用及机制

The proliferation and migration of fibroblast-like synoviocytes (FLS) in rheumatoid arthritis (RA) play a key role in abnormal inflammation and progressive destruction of cartilage and bone. Rho signaling is a crucial role in the regulation of cell motility and significantly activated in RA-FLS. Our previous study found that the concentrations of soluble G6PI in the sera and synovial fluids of RA patients were elevated, and the sera G6PI level correlated positively with the activity of RA. G6PI also enhanced the proliferation capacity on cultured RA-FLS. G6PI is also named autocrine mobile factor, and can promote tumor cell invasion and metastasis via Rho signaling. But so far the pathogenesis of G6PI in RA remains unclear. Further study will be continued. With construction of G6PI-shRNA and G6PI lentivirus vector, the regulatory effects of G6PI on migration and invasion of RA-FLS were to be explored by Bio-plex suspension chips and qPCR Array in cellular and mouse RA model. We will also screen and identify the key effector molecules regulated by G6PI in Rho signaling pathway, to further elucidate the molecular mechanism of G6PI in RA. In addition, it is tempting to develop a new strategy in the prevention and treatment of joint lesions from a new angle by suppressing G6PI and / or blocking Rho signaling pathway.

滑膜成纤维样细胞（FLS）活化增殖和侵袭性增强是类风湿性关节炎（RA）滑膜增生以及关节持续破坏的关键环节。Rho信号在调控细胞运动中起关键作用，研究发现其在RA-FLS中显著激活。课题组前期研究发现RA患者血清和关节液中葡萄糖6磷酸异构酶（G6PI）含量异常增高，升高程度与病情活动度呈正相关，且能促进FLS活化、增殖。G6PI又称为肿瘤自分泌移动因子，可通过受体途径激活Rho信号促进肿瘤细胞转移与侵袭，但在RA关节病变中的作用未阐明。本项目拟继续深入，利用G6PI过表达和干扰慢病毒载体，采用Bio-plex悬液芯片、qPCR Array等技术，从细胞和动物水平研究G6PI在RA-FLS迁移和侵袭中的调控作用， 筛选、鉴定G6PI所调控Rho信号通路的关键效应分子，阐明G6PI调控作用的分子机制，并从抑制G6PI和/或阻断Rho信号通路关键效应分子角度探索防治RA关节病变的新策略。

RA的病理过程主要是炎症细胞的浸润和滑膜组织的增生以及软骨和骨质破坏，其中滑膜衬里层的FLS的活化增殖和侵袭性增强是RA关节滑膜增生以及关节持续破坏的关键环节，抑制RA-FLS的这一病理特性，将有助于控制病情、减少关节骨质受损。本课题组证实G6PI在RA患者血清、关节液以及滑膜组织中含异常增高，且与关节破坏、炎症浸润、骨质侵袭等病情活动度成正相关。同时动物实验显示G6PI能诱导DBA/1鼠发生不同程度的、类似于人RA关节滑膜病变的关节炎。进一步研究发现G6PI可以显著促进RA-FLS的增殖、迁移和侵袭，抑制RA-FLS中G6PI的表达，其生长和迁移均明显受到抑制。通过qPCR Array基因表达分析系统分析筛选和鉴定G6PI调控RA-FLS侵袭相关靶分子。结果证实G6PI可以通过RHOA/ROCK介导的信号通路，促进E-Catherine、MMP9、MMP3等侵袭相关基因的表达,从而促进FLS的迁移和侵袭性，促进关节骨和软骨的破坏。同时成功构建靶向抑制G6PI的纳米载体 siG6PI-MSN，并进一步联合RHO信号通路的抑制剂，在RA模型中，初步探索其在RA治疗中的应用，结果证实经G6PI靶向纳米载体或者RHO通路抑制剂治疗的关节炎鼠，病情获得了部分缓解，关节肿胀指数明显降低，关节腔积液明显减少,关节骨质的破坏有所缓解。本次研究进一步阐明G6PI在RA发病中的调控机制，并从抑制G6PI和/或阻断Rho信号通路关键效应分子角度探索防治RA关节病变的新策略。