State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST), Key Laboratory of Oral Biomedicine Ministry of Education (KLOBM), School and Hospital of Stomatology, Wuhan University, 237 Luoyu Road, Wuhan, Hubei, China.
Department of Stomatology, Zhongnan Hospital of Wuhan University, Wuhan, China.
Sci Rep. 2021 Aug 3;11(1):15695. doi: 10.1038/s41598-021-95251-9.
Subchondral bone degeneration is the main pathological change during temporomandibular joint (TMJ) osteoarthritis (OA) development. Netrin-1, an axon-guiding factor, might play roles in OA development and pain. The purpose of this study was to investigate the expression of Netrin-1 in TMJ OA and its possible role in the progression of TMJ OA and pain. The synovial fluids of temporomandibular joint disorders (TMDs) patients were collected for Netrin-1 by enzyme linked immunosorbent assay (ELISA). TMJ OA model was built by MIA joint injection, and then the von Frey test, hematoxylin & eosin (H&E) staining, toluidine blue (TB) staining, immunohistochemical (IHC) staining and micro-CT were performed. After induction of osteoclast differentiation of raw264.7 cells, immunofluorescence (IF) was used to detect the Netrin-1 and its receptors on osteoclast membrane. The concentration of Netrin-1 increased in the synovial fluid of TMJ OA patients. After MIA injection to TMJ, the head withdrawal threshold (HWT) was significantly decreased. Microscopically, the structural disorder of subchondral bone was the most obvious at the 2nd week after MIA injection. In addition, Netrin-1 expression increased in the subchondral bone at the 2nd week after MIA injection. In vitro, the expressions of Netrin-1 and its receptor Unc5B were upregulated on the osteoclast membrane. Netrin-1 might be an important regulator during bone degeneration and pain in the process of TMJ OA.
软骨下骨退变是颞下颌关节（TMJ）骨关节炎（OA）发展过程中的主要病理变化。轴突导向因子 Netrin-1 可能在 OA 的发展和疼痛中发挥作用。本研究旨在探讨 Netrin-1 在 TMJ OA 中的表达及其在 TMJ OA 进展和疼痛中的可能作用。通过酶联免疫吸附试验（ELISA）检测颞下颌关节紊乱病（TMD）患者的滑液中的 Netrin-1。通过 MIA 关节内注射建立 TMJ OA 模型，然后进行 von Frey 试验、苏木精和伊红（H&E）染色、甲苯胺蓝（TB）染色、免疫组织化学（IHC）染色和 micro-CT。在诱导 raw264.7 细胞破骨细胞分化后，通过免疫荧光（IF）检测破骨细胞膜上的 Netrin-1 和其受体。TMJ OA 患者的滑液中 Netrin-1 浓度增加。MIA 注射 TMJ 后，头部撤回阈值（HWT）明显降低。显微镜下，MIA 注射后第 2 周，软骨下骨结构紊乱最明显。此外，MIA 注射后第 2 周，软骨下骨中 Netrin-1 表达增加。体外，破骨细胞膜上的 Netrin-1 和其受体 Unc5B 的表达上调。Netrin-1 可能是 TMJ OA 过程中骨退变和疼痛过程中的一个重要调节因子。
