MicroRNA-146靶向Toll样受体4信号通路参与痛风急性炎症自发缓解的机制研究

The molecular mechanism of spontaneous resolution of acute gouty inflammation is still unclear, although spontaneous resolution is one of the characteristics in gout differentiated from the other arthropathy and auto-inflammatory diseases. Studies have demonstrated that toll-like receptor (TLR) 4-interleukin (IL)-11β signalling pathway is involved in the pathogenesis of acute gouty arthritis induced by monosodium urate (MSU) crystal. MicroRNA(MiR)-146a/b can repress TLRs activation induced by LPS to tightly regulate inflammatory response. We found expression of miR-146a/b was significantly increased while IL-1β decreased in the spontaneous resolution process of acute gouty inflammation. We speculated that miR-146a/b might target TLR4 signalling pathway to negative regulate the inflammation mediated by MSU, and to be involved in the spontaneous resolution of acute gouty arthritis. Overexpression or non-expression of miR-146a/b lentiviral vectors will be constructed, and be transfected with THP-1 cell, and cytokines will be measured after MSU crystal stimulated. Whether miR-146a/b binding one of the element or more elements of the TLR4 signalling to repress the inflammation induced by MSU will be investigate using Luciferase Reporter Assay, siRNA, chromatin Immunoprecipitation, electrophoretic mobility shift assay; whether miR-146a/b and anti-inflammatory cytokines are co-involved in the pathogenesis of the spontaneous resolution and the concret molecular mechanism will be studied.

痛风急性炎症的自限性是其区别于其他关节病或自身炎性疾病的特征之一，但其炎症自限的确切分子机制不明确。研究证实TLR4-IL1β通路参与尿酸钠（MSU）晶体诱导的痛风炎症反应。MicroRNA(MiR)-146a/b可抑制LPS诱导的TLRs活化，从而精细调节炎症反应。我们发现随着痛风炎症的自限， miR-146a/b的表达增加而IL1β降低。我们推测miR-146a/b通过靶向TLR4通路抑制MSU晶体诱发的炎症因子来参与痛风炎症的自发缓解。我们拟构建miR-146过表达与抑制miR-146表达的慢病毒载体，分别转染THP细胞，MSU刺激后检测相关炎症因子。再通过荧光酶报告载体、siRNA、染色质免疫共沉淀、凝胶迁移实验等方法探索miR-146a/b是否通过结合TLR4通路中一个或多个分子而抑制MSU诱导的炎症因子，研究miR-146a/b是否与抗炎因子共同参与痛风炎症自限及具体分子机制。

痛风急性炎症的自限性是其区别于其他关节病或其他自身炎性疾病的特征之一，但其炎症自限的确切分子机制并不明确。研究已经证实TLR4-IL-1β通路参与了尿酸钠（MSU）晶体诱导的痛风炎症反应。MicroRNA (miR) 因其在炎性疾病中的负调节作用而备受关注。我们前期研究发现随着痛风炎症的逐渐好转，MiR-146a在外周血的表达逐渐增加而IL-1β浓度逐渐降低。本研究分别通过过表达或低表达MiR-146a后发现TLR4及其下游分子的表达刚好与MiR-146a的表达相反；当抑制TLR4后，TLR4下游分子及炎症介质基本不受MiR-146a表达量的影响。在MSU诱导的炎症中，抗炎因子TGF-β1、IL37与MiR-146a共同参与了炎症的负反馈调控，但TGF-β1、IL37不受MiR-146a调节。本研究提示MiR-146a可靶向TLR4-IL-1β信号通路抑制痛风急性炎症反应，从而参与痛风炎症的自发缓解。本研究为痛风急性炎症的治疗提供了新的思路。