瘦素及其受体Ob-Rb在颞下颌关节骨关节炎中的作用研究

Leptin plays an important role in the pathological process of osteoarthritis, but the current studies are mostly limited to the knee joint, hip joint and the joint of fingers, there almost no direct study reports about TMJ-OA . Therefore this study includes the following aspects: 1. The leptin expression in synovial of TMJ-OA patients was detected, then analyze the relationships between the leptin levels and patient age, gender, BMI, the degree of inflammation and imaging manifestation of the disease. 2. The TMJ-OA model was established in rats, then observe the change of pathological lesions in different period of TMJ-OA. The expression of cytokines related to inflammation and distribution of leptin and its receptor Ob-Rb were detected. The TMJ-OA models were also established in obese rats induced by fat diet. Obesity may leads to the elevated leptin levels in rats serum. Observed the effects of elevated leptin levels on TMJ-OA. 3. Use leptin to stimulate the rat temporomandibular joints synovial fibroblasts and chondrocytes of mandibular condyle, then detect the expression levels of inflammatory cytokines, and to explore the molecular mechanism of leptin effects on the two cells. By liposome transfection or RNAi knockdown technology, Ob-Rb gene expression of targeted cells was increased or decreased. Study the effects of the leptin on the cells after of which Ob-Rb gene was increased or decreased. This study may clarify etiology and pathogenesis for the TMJ-OA.

瘦素在OA发生发展中发挥重要作用，但目前研究多限于膝关节、髋关节和手指间关节等，关于TMJ-OA几乎没有任何直接的文献报道。本课题拟研究：1.检测TMJ-OA患者滑液瘦素表达水平，分析其与患者年龄、性别、BMI、炎症程度及影像学表现之间的关系。2.建立大鼠TMJ-OA模型，观察病变不同时段TMJ病理改变；检测瘦素及其受体Ob-Rb表达分布情况及相关炎性因子表达水平。在此基础上高脂饮食诱导大鼠肥胖并构建TMJ-OA模型，观察肥胖导致的瘦素水平升高对TMJ-OA的影响。3. 瘦素刺激大鼠颞下颌关节滑膜成纤维细胞和髁突软骨细胞，检测相关炎性因子表达水平，并探索瘦素作用于上述细胞的分子机制；采用脂质体瞬时转染过表达或RNAi技术靶向敲减细胞Ob-Rb基因，研究Ob-Rb基因表达升高或降低后瘦素对细胞作用变化情况。本课题研究对于明确TMJ-OA病因和发病机制，从而寻找新的治疗思路和方法具有重要意义。

背景：颞下颌关节骨关节炎（temporomandibular joint osteoarthritis, TMJ-OA）是颞下颌关节骨关节的器质性病变，为颞下颌关节紊乱病（temporomandibular disorder,TMD）中最为严重的一种。瘦素（Leptin）在OA发生发展中发挥重要作用，但目前研究多限于膝关节、髋关节和手指间关节等，关于TMJ-OA几乎没有任何直接的文献报道。..主要研究内容：本研究项目建立了大鼠TMJ-OA的动物模型；体外进行了瘦素(Leptin)作用于人颞下颌关节滑膜成纤维细胞和髁突软骨细胞炎性因子分泌影响的实验研究，并探究了Leptin通过瘦素受体(Ob-Rb)作用于上述细胞的分子机制；同时我们收集了TMD患者及健康志愿者关节滑液，检测了Leptin及相关炎性因子的表达水平，同时记录患者年龄、性别，分析Leptin表达水平与上述各项指标之间的联系，以及与患者临床症状、炎症程度及影像学表现之间的关系。..重要结果、关键数据及其科学意义：完全弗氏佐剂诱导建立大鼠TMJ-OA模型，组织学检测显示滑膜及髁突软骨有明显的炎症改变。通过检测TMJ-OA患者关节滑液中Leptin含量，骨关节病组显著性高于其他各组，不可复性关节盘移位组和可复性关节盘移位组高于对照组，但不具有显著性。IL-6含量，骨关节病组显著性高于其他各组，同时不可复性关节盘移位组和可复性关节盘移位组显著高于对照组。但Leptin与IL-6含量间不具备显著相关性。体外实验，Leptin刺激人颞下颌关节滑膜成纤维细胞可通过激活JAK2/STAT3, p38 MAPK 和 PI3K/Akt信号通路明显诱导炎症因子IL-6的表达。这一作用主要通过细胞表面的瘦素受体发挥作用。采用RNA干扰技术靶向敲减大鼠颞下颌关节滑膜成纤维细胞 Ob-Rb基因，瘦素刺激IL-6的表达显著下降。该实验研究对于明确TMJ-OA病因和发病机制，从而寻找新的治疗思路和方法具有一定意义。