P2X7R调控急性痛风性关节炎发病的分子机制研究

Acute gouty arthritis is an inflammatory disease and IL-1β is believed to be the main cytokine involved in acute attack of gout arthritis. Previous studies found that uric acid can participate in the pathogenesis of acute gouty arthritis by stimulating IL-1β secretion in a variety of ways. However, uric acid signaling is not enough for explanation of some clinical phenomena. For example, some hyperuricemia patients never have onset of such disease, suggesting that stimulation of these pathways for IL-1β secretion is not sufficient for the onset of acute gouty arthritis, and may requires the synergistic effect of other pathways. Our previous research demonstrated that more IL-1β is produced from.leukocytes stimulated by combing uric acid and ATP in gout patients than hyperuricemia patients which never had acute attacks, suggesting that ATP-P2X7R axis is main determinant for acute attack of gout arthritis. Previous studies also showed that the regulative ability of P2X7R on IL-1β secretion is affected by P2X7R polymorphisms. Based on these findings, in this study, we will estimate the relationship between P2X7R genotype and IL-1β production, explore molecular mechanism of P2X7R for acute gout arthritis in multiple level by vivo, vitro and case control studies. Our program might provide new insight into the prevention and tretment for acute gouty arthritis.

痛风是一种炎症性疾病，IL-1β被认为是参与痛风性关节炎发病的主要细胞因子。既往证据表明尿酸盐晶体可以通过多种途径刺激IL-1β分泌，进而参与痛风发病。但是这种以尿酸盐为致病信号的理论无法解释部分高尿酸血症患者从不出现痛风发病的临床现象，提示痛风发病还存在其他致病信号。本项目组近期研究发现用尿酸盐和ATP共同刺激痛风患者外周血白细胞产生的IL-1β显著高于从不出现痛风发病的高尿酸血症患者，而单独使用尿酸盐刺激则没有差异，提示ATP及其受体P2X7R的作用是决定痛风能否发病的重要因素。前期研究还发现P2X7R基因多态性与IL-1β的分泌能力有关。基于上述内容，本项目拟在前期研究基础上，从P2X7R的不同SNP基因型与IL-1β分泌能力间相关联的角度，通过动物实验、临床实验、基因多态性和功能研究等多层面揭示P2X7R调控痛风发病的分子机制。本项目完成将有助于为痛风防治提供新思路和新的靶点。

痛风是一种炎症性疾病，IL-1β被认为是参与痛风性关节炎发病的主要细胞因子。既往证据表明尿酸盐晶体可以通过多种途径刺激IL-1β分泌，进而参与痛风发病。本项目从P2X7R的不同SNP基因型与IL-1β分泌能力间相关联的角度，通过动物实验、临床实验、基因多态性和功能研究等多层面揭示P2X7R调控痛风发病的分子机制。主要研究内容：（1）探讨嘌呤能受体P2X7R在大鼠急性痛风性关节炎发病机制中的作用（2）通过建立稳定表达P2X7R的野生型和突变体型THP-1源性单核细胞系，在高尿酸背景下分析P2X7R的野生型和三种不同SNPs基因型的功能改变（3）比较痛风患者和髙尿酸血症患者P2X7R基因汉族人群SNP位点的频率,确定痛风的P2X7R易感基因型,分析P2X7R基因SNP与痛风关节炎发病的关联。研究结果：（1）P2X7R通过激活NLRP3炎症小体促进IL-1β的释放：在12h，ATP组P2X7R，NLRP3和IL-1βmRNA的表达显著高于BBG组和对照组（P = 0.001,0.008; P = 0.000,0.012; P = 0.002,0.034）；在24h时，ATP组IL-1β的表达明显高于BBG组和对照组（P = 0.000,0.001），其次是对照组（P = 0.007），三组间差异有统计学意义（2）在高尿酸背景下，MA组中， Ala 348> Thr相比野生型以及空病毒型上调上清液中IL-1β水平，差异有统计学意义（P = 0.0007，P = 0.013）；野生型比空病毒型上清液中IL-1β水平高，差异无统计学意义。Glu 496>Ala相比野生型下调上清液中IL-1β水平，差异有统计学意义（P = 0.0189）；比空病毒型上清液中IL-1β水平低，差异无统计学意义。Arg 307>Gln相比野生型下调上清液中IL-1β水平，差异有统计学意义（P = 0.0164）；比空病毒型上清液中IL-1β水平低，差异无统计学意义。（3）痛风组rs1718119基因AA、AG、GG的基因型频率分别为5.9%、34.8%、59.3%，高尿酸组AA、AG、GG的基因型频率分别为2.9%、14.3%、82.9%，两组基因型差异具有统计学意义（2=13.48, P=0.001）。痛风组等位基因A和G的频率分别为23.3%和76.7%，高尿酸组等位基因A和G的频率分别为10