Jiang Yuan-Yuan, Wen Juan, Gong Cheng, Lin Shuang, Zhang Cai Xia, Chen Sheng, Cheng Wei, Li Huang
Department of Orthodontics, Nanjing Stomatological Hospital, Medical School of Nanjing University, No. 30 Zhongyang Road, Nanjing, 210000, Jiangsu, China.
Department of Pathology, Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, China.
J Orthop Res. 2018 Apr;36(4):1228-1237. doi: 10.1002/jor.23748. Epub 2017 Nov 20.
Osteoarthritis induced by compressive mechanical force is characterized by decreased chondrocyte proliferation and degradation of the ECM. To examine underlying mechanisms of the pathological changes of mandibular cartilage induced by compressive mechanical force, an established animal model was used to examine Wnt signaling activation by glycogen synthase kinase-3 beta (GSK3β) inhibitor 6-Bromoindirubin-3'-oxime (BIO) injection in vivo. Histological changes in mandibular cartilage were assessed via hematoxylin & eosin (HE), masson, and alcian blue staining. Immunohistochemistry and real-time PCR were performed to evaluate activation of the Wnt signaling pathway and chondrocytes proliferation markers. Chondrocytes apoptosis was examined by TUNEL staining. During the compressive mechanical force loading-mediated process, Wnt signaling was largely inhibited, which showed the inhibited expression of β-catenin and the increased expression of GSK-3β. The expression of chondrocytes proliferation markers Ki67, and proliferating cell nuclear antigen (PCNA) also decreased. With BIO injection, the Wnt signaling was restored and the proliferation of mandibular chondrocytes was also increased in the late stage (7 days) of compressive mechanical force loading. Finally, the decreasing mandibular cartilage thickness, the degradation of extracellular matrix, and the erosion of bone trabecula were subsequently restored. Also, the changes of extracellular matrix markers such as collagen II and collagen X, matrix metalloproteases, and inflammatory cytokines were reversed followed by the injection of BIO. In summary, compressive mechanical force decreased endogenously Wnt signaling, leading to impaired proliferation in chondrocytes and degradation in cartilage matrix. Restoration of Wnt signaling largely recovered the proliferation defects and alleviated the pathological changes of mandibular cartilage. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1228-1237, 2018.
压缩机械力诱导的骨关节炎的特征是软骨细胞增殖减少和细胞外基质（ECM）降解。为了研究压缩机械力诱导的下颌软骨病理变化的潜在机制，使用已建立的动物模型，通过体内注射糖原合酶激酶-3β（GSK3β）抑制剂6-溴靛玉红-3'-肟（BIO）来检测Wnt信号通路的激活。通过苏木精和伊红（HE）染色、马松染色和阿尔辛蓝染色评估下颌软骨的组织学变化。进行免疫组织化学和实时聚合酶链反应（PCR）以评估Wnt信号通路的激活和软骨细胞增殖标志物。通过末端脱氧核苷酸转移酶介导的缺口末端标记（TUNEL）染色检测软骨细胞凋亡。在压缩机械力加载介导的过程中，Wnt信号通路受到很大抑制，表现为β-连环蛋白表达受抑制和GSK-3β表达增加。软骨细胞增殖标志物Ki67和增殖细胞核抗原（PCNA）的表达也降低。注射BIO后，在压缩机械力加载的后期（7天），Wnt信号通路恢复，下颌软骨细胞的增殖也增加。最后，下颌软骨厚度的减少、细胞外基质降解和骨小梁侵蚀随后得到恢复。此外，注射BIO后，细胞外基质标志物如Ⅱ型胶原蛋白和X型胶原蛋白、基质金属蛋白酶和炎性细胞因子的变化也得到逆转。总之，压缩机械力降低内源性Wnt信号通路，导致软骨细胞增殖受损和软骨基质降解。Wnt信号通路的恢复在很大程度上恢复了增殖缺陷并减轻了下颌软骨的病理变化。©2017骨研究学会。由威利期刊公司出版。《矫形外科学研究杂志》36:1228 - 1237，2018年。
