Orthopedic Institute, Medical College, Soochow University , Suzhou, P.R. China.
Department of Orthopedics, The First Affiliated Hospital of Soochow University , Suzhou, P.R. China.
Connect Tissue Res. 2020 Sep;61(5):445-455. doi: 10.1080/03008207.2019.1611796. Epub 2019 Jul 5.
Osteoarthritis (OA) is a chronic degenerative joint disease. Sensory nerves play an important role in bone metabolism and in the progression of inflammation. This study explored the effects of sensory nerve on OA progression at early stage in mice.
OA was induced via destabilization of the medial meniscus (DMM) in C57BL/6 mice. Sensory denervation was induced by subcutaneous injection of capsaicin (90 mg/kg) one week prior to DMM. One week after capsaicin injection, sensory denervation in the tibia was confirmed by immunofluorescent staining. Four weeks after DMM, micro-CT scans, histological analysis, and RT-PCR tests were performed to evaluate OA progression.
Subcutaneous injection of capsaicin successfully induced sensory denervation in tibia. The Osteoarthritis Research Society International (OARSI) score and synovitis score of the capsaicin+DMM group were significantly higher than the score of the vehicle+DMM group. The BV/TV of the tibial subchondral bone in the capsaicin+DMM group was significantly lower than in the vehicle+DMM group. In addition, the level of expression of inflammatory factors in the capsaicin+DMM group was significantly higher than in the vehicle+DMM group.
Capsaicin-induced sensory denervation accelerated OA progression at early stage in mice. To put it another way, sensory nerve protects from OA progression at early stage in mice.
骨关节炎（OA）是一种慢性退行性关节疾病。感觉神经在骨代谢和炎症进展中起着重要作用。本研究探讨了感觉神经在早期小鼠 OA 进展中的作用。
通过内侧半月板不稳定（DMM）在 C57BL/6 小鼠中诱导 OA。在 DMM 前一周通过皮下注射辣椒素（90mg/kg）诱导感觉神经去神经支配。辣椒素注射后一周，通过免疫荧光染色确认胫骨中的感觉神经去神经支配。在 DMM 后 4 周，进行 micro-CT 扫描、组织学分析和 RT-PCR 测试，以评估 OA 进展。
皮下注射辣椒素成功诱导了胫骨中的感觉神经去神经支配。辣椒素+DMM 组的骨关节炎研究协会国际（OARSI）评分和滑膜炎评分明显高于载体+DMM 组。辣椒素+DMM 组胫骨软骨下骨的 BV/TV 明显低于载体+DMM 组。此外，辣椒素+DMM 组炎症因子的表达水平明显高于载体+DMM 组。
辣椒素诱导的感觉神经去神经支配加速了早期小鼠 OA 的进展。换句话说，感觉神经在早期保护小鼠免受 OA 进展的影响。
