基于IL-23/Th17炎症轴探讨苗药黑骨藤提取物治疗类风湿关节炎的分子机制

T helper cell 17 (Th17) is an important effect T cell subsets in Rheumatoid Arthritis(RA), and Interleukin-17(IL-17) is main effector molecule of Th17 that has a primary role to run immunoregulation. According to the latest research literature which can confirm the inflammation axis consisted of Interleukin-23(IL-23)/Th17 plays a pivotal role in the developing of chronic inflammation arthropathy such as RA, its unbalance of signal pathway maybe the foundation of chronic synovitis in RA. Periploca forrestii Schltr is used to treat Jiangjianfeng in Guizhou Miao people，and the Miao medicine theory consider that congestion turns into disease and patency becomes healthy. When the noxious wind, coldness and dampness attack human body, they will be latent into bones and joints, further let sinew and vessel become congestion, in the end turn into the disease-Jiangjianfeng which could be treated by clear sinew and disperse the pathogenic factor. Beneath this theory, our early study proved that both Miao medicine Periploca forrestii Schltr total glycosides and its compound preparation have a good effect in the treatment of anti-RA. So based on early research, we come up with a hypothesis that IL-23/Th17 inflammation axis is the critical factor of synovitis in RA, and Miao medicine Periploca forrestii Schltr total glycosides could regulate the axis and its related gene, and further to alleviate the synovitis in RA. From the above, we plan to build RA animal model and cell model to probe the effect of using Miao medicine Periploca forrestii Schltr total glycosides to intervene the models, and further demonstrate the curative effect of using Miao medicine Periploca forrestii Schltr total glycosides to treat RA, which maybe hopeful to explore a new drug to treat RA.

Th17是类风湿关节炎(RA)重要的效应T细胞亚群，IL-17是Th17细胞发挥免疫调节作用的主要效应因子。IL-23是维持Thl7细胞活性和扩增，诱导Th17细胞分泌IL-17的关键细胞因子。据最新的国内外研究文献证实IL-23/Th17构成的炎症轴在RA等慢性炎症关节病的发病中起枢纽作用，其信号通路的失调可能是RA慢性滑膜炎症的基础。黑骨藤是贵州苗族民间用于治疗“僵腱风”的常用药，苗医理论认为“壅塞为病，通达为康”，风寒湿毒侵袭人体，蕴结骨与关节，筋脉不通则发病，治疗宜“通筋散邪”，并在前期研究中证实黑骨藤提取物和黑骨藤复方均具有良好的抗RA作用。因此，我们提出IL-23/Th17炎症轴是RA滑膜炎症的关键因素，并在前期研究的基础上，建立RA动物模型和细胞模型，探讨黑骨藤提取物调控IL-23/Th17炎症轴相关基因的表达，从而缓解RA滑膜炎症的科学假说，有望为RA的治疗发掘新的用药。

IL-23对维持Th17细胞和IL-17的分泌具有重要作用，后者是类风湿关节炎(RA)发病机制的主要刽子手。IL-23主要通过IL-17和Th17细胞产生作用，提示Th17/IL-23在RA关节炎症和破坏中的重要作用。本研究以RA经典模型—胶原诱导性关节炎（CIA）大鼠和RA滑膜细胞（synovial cell）为研究对象，CIA大鼠随机分成6组—分别为空白组、模型对照组、苗药黑骨藤提取物（PFE）低剂量组、苗药黑骨藤提取物中剂量组、苗药黑骨藤提取物高剂量组、 来氟米特组，RA滑膜细胞分为5组—空白组、苗药黑骨藤提取物低剂量组、苗药黑骨藤提取物中剂量组、苗药黑骨藤提取物高剂量组、 来氟米特组。我们发现苗药黑骨藤提取物可降低CIA模型大鼠关节炎指数、关节肿胀度，减少炎性细胞浸润及新生血管形成，在CIA大鼠滑膜组织中检测到了升高的IL-6、IL-17、IL-23炎症因子，高表达的转录因子RORα和STAT3以及IL-17、IL-23p19mRNA的高表达；培养的RA滑膜细胞中检测出高分泌量的IL-6、IL-17、IL-23，高表达水平的IL-23、IL-17mRNA基因，高表达蛋白水平的IL-23R、JAK2、STAT3、pJAK2、pSTAT3、ROR-γt和低表达的FOXP3蛋白水平，证实了IL-17、IL-23在RA炎症反应中的存在，并通过检测Th17细胞标记物RORγt和Foxp3的相对mRNA和蛋白水平，间接证实了Th17细胞在滑膜细胞异常增殖和凋亡中发挥着重要作用，IL-23/Th17炎症轴相关因子的表达与RA滑膜细胞的异常增殖与凋亡相关，苗药黑骨藤提取物可通过降低IL17/IL23分泌、影响Th17细胞分化来改善RA。提示Th17/IL-23炎症轴的异常可能是RA发病的机制之一，苗药黑骨藤提取物可能通过影响该炎症轴相关的致炎因子、蛋白及mRNA的表达从而减轻炎症的程度、减缓病程的进展。