Objective: To investigate the role and mechanism of S100 calcium binding protein B (S100B) in osteoarthritis (OA) cartilage damage repair.
Methods: Twenty New Zealand rabbits were randomly divided into control group and model group, with 10 rabbits in each group. Rabbits in the model group were injured by the right knee joint immobilization method to make the artilage injury model, while the control group did not deal with any injury. After 4 weeks, the levels of interleukin-1β (IL-1β) and tumor necrosis factor α (TNF-α) in synovial fluid were detected by ELISA method; the mRNA and protein expressions of S100B, fibroblast growth factor 2 (FGF-2), and FGF receptor 1 (FGFR1) in cartilage tissue were examined by real-time fluorescence quantitative PCR (qRT-PCR) and Western blot assay. Human synovial fibroblasts (SF) were isolated and cultured in vitro. The effects of S100B overexpression and knockdown on the levels of IL-1β and TNF-α (ELISA method) and the expressions of FGF-2 and FGFR1 gene (qRT-PCR) and protein (Western blot) were observed. Moreover, the effects of FGFR1 knockdown in above S100 overexpression system on the levels of IL-1β and TNF-α (ELISA method) and the expressions of FGF-2 and FGFR1 gene (qRT-PCR) and protein (Western blot) were observed.
Results: ELISA detection showed that the expressions of IL-1β and TNF-α in the synovial fluid of the model group were significantly higher than those of the control group ( P<0.05); qRT-PCR and Western blot detection showed that the mRNA and protein expressions of S100B, FGF-2, and FGFR1 in cartilage tissue were significantly higher than those of the control group ( P<0.05). Overexpression and knockdown S100 could respectively significantly increase and decrease lipopolysaccharides (LPS) induced IL-1β and TNF-α levels elevation and the mRNA and protein expressions of FGF-2 and FGFR1 ( P<0.05); whereas FGFR1 knockdown could significantly decrease LPS induced IL-1β and TNF-α levels elevation and the mRNA and protein expressions of FGF-2 and FGFR1 ( P<0.05).
Conclusion: S100B protein can regulate the inflammatory response of SF and may affect the repair of cartilage damage in OA, and the mechanism may be related to the activation of FGF-2/FGFR1 signaling pathway.
目的: 探讨 S100 钙结合蛋白 B（S100B）在骨性关节炎（osteoarthritis，OA）软骨损伤修复中的作用及机制。.
方法: 取 20 只新西兰兔随机分为对照组和模型组，每组 10 只。模型组兔右膝关节制动法制备软骨损伤模型，对照组不作任何处理。4 周后采用 ELISA 法检测关节液 IL-1β、TNF-α 水平，实时荧光定量 PCR（real-time fluorescence quantitative PCR，qRT-PCR）和 Western blot 检测软骨组织 S100B、FGF-2、FGF 受体 1（FGF receptor 1，FGFR1）基因及蛋白表达。分离培养人滑膜成纤维细胞（synovial fibroblasts，SF），观察过表达、干扰 S100B 以及拮抗 FGFR1 对细胞 IL-1β 和 TNF-α 水平（ELISA 法）以及 FGF-2 和 FGFR1 基因（qRT-PCR 检测）和蛋白（Western blot 检测）表达的影响。.
结果: ELISA 检测示模型组兔关节液中 IL-1β 和 TNF-α 表达水平均明显高于对照组（ P<0.05）；qRT-PCR 和 Western blot 检测示，模型组兔软骨组织 S100B、FGF-2、FGFR1 mRNA 和蛋白表达量均显著高于对照组（ P<0.05）。过表达和干扰 S100 能够分别显著升高和降低脂多糖（lipopolysaccharides，LPS）诱导的 IL-1β 和 TNF-α 水平及 FGF-2 和 FGFR1 mRNA 和蛋白表达，差异均有统计学意义（ P<0.05）。而拮抗 FGFR1 能够显著降低 LPS 诱导的 IL-1β 和 TNF-α 水平及 FGF-2 和 FGFR1 mRNA 和蛋白表达，差异均有统计学意义（ P<0.05）。.
结论: S100B 能够调节 SF 炎性反应并可能影响 OA 软骨损伤修复，其机制可能与激活 FGF-2/FGFR1 信号通路有关。.
Keywords: S100 calcium binding protein B; cartilage damage; fibroblast growth factor 2; fibroblast growth factor receptor 1; osteoarthritis; synovial fibroblasts.