Zhang Qin, Li Ning, Dai Zhen-Zhen, Liu Xiao-Man, Ding Jing, Sha Lin, Li Hai
1Department of Pediatric Orthopedics, Xin Hua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China.
Shanghai Jiao Tong University School of Medicine, Shanghai, China.
Front Immunol. 2025 Aug 15;16:1659230. doi: 10.3389/fimmu.2025.1659230. eCollection 2025.
Disruption of growth plate cartilage often leads to severe bone growth defects in children, necessitating novel therapeutic strategies. Following growth plate injury, an inflammatory response is rapidly initiated, resulting in the release of pro-inflammatory cytokines such as IL-6 into the injured tissue, which subsequently induce and enhance osteoclast generation and differentiation. This study investigates the role of SHP2 in regulating IL-6-driven osteoclastogenesis during growth plate injury repair.
Tibial drill-hole injuries were induced in C57BL/6 mice (n=9), with SHP099 (30 mg/kg, intra-articular) administered to intervention groups and tissues were harvested for qPCR/histology. RAW 264.7 cells were treated with RANKL (100 ng/ml) ± IL-6 (100 ng/ml) ± SHP099 (15 µM). Osteoclast differentiation, expression level of pro-inflammatory cytokines and the associated signaling pathway were assessed via TRAP staining, Western blot, qPCR and ELISA.
SHP2/PTPN11, osteoclast markers (CTSK/OSCAR) and pro-inflammatory cytokines (IL-6, IL-1β, TNF-α) was upregulated and could be inhibited by SHP099 at injury sites. IL-6 enhanced p-SHP2/p-TAK1 expression, osteoclastogenesis and inflammatory response in vitro, while SHP099 effectively reduced osteoclast numbers, downregulating CTSK/OSCAR and pro-inflammatory cytokines (IL-6, IL-1β, TNF-α). Furthermore, the NF-κB pathway remained unaffected by SHP099, indicating a distinct signaling mechanism through which SHP2 regulates osteoclastogenesis.
Our findings underscore the pivotal role of SHP2 as a downstream signaling molecule of IL-6 in mediating inflammatory responses during bone repair, suggesting that SHP2 inhibition may present a novel therapeutic approach to prevent pathological bone remodeling and enhance recovery following growth plate injuries. Future investigations should focus on the translational potential of SHP2 inhibitors in pediatric orthopedics.
生长板软骨的破坏常常导致儿童严重的骨骼生长缺陷，因此需要新的治疗策略。生长板损伤后，炎症反应迅速启动，导致促炎细胞因子如白细胞介素-6（IL-6）释放到受损组织中，随后诱导并增强破骨细胞的生成和分化。本研究探讨了SHP2在生长板损伤修复过程中调节IL-6驱动的破骨细胞生成中的作用。
对C57BL/6小鼠（n = 9）造成胫骨钻孔损伤，干预组给予SHP099（30mg/kg，关节内注射），然后采集组织进行qPCR/组织学检测。RAW 264.7细胞用RANKL（100ng/ml）±IL-6（100ng/ml）±SHP099（15μM）处理。通过抗酒石酸酸性磷酸酶（TRAP）染色、蛋白质免疫印迹法（Western blot）、qPCR和酶联免疫吸附测定（ELISA）评估破骨细胞分化、促炎细胞因子的表达水平及相关信号通路。
在损伤部位，SHP2/PTPN11、破骨细胞标志物（组织蛋白酶K/破骨细胞相关受体，CTSK/OSCAR）和促炎细胞因子（IL-6、白细胞介素-1β、肿瘤坏死因子-α，IL-1β/TNF-α）上调，且可被SHP099抑制。IL-6在体外增强了p-SHP2/p-TAK1表达、破骨细胞生成和炎症反应，而SHP099有效减少了破骨细胞数量，下调了CTSK/OSCAR和促炎细胞因子（IL-6、IL-1β、TNF-α）。此外，核因子κB（NF-κB）通路不受SHP099影响，这表明SHP2调节破骨细胞生成存在独特的信号机制。
我们的研究结果强调了SHP2作为IL-6的下游信号分子在骨修复过程中介导炎症反应的关键作用，表明抑制SHP2可能是一种预防病理性骨重塑和促进生长板损伤后恢复的新治疗方法。未来的研究应聚焦于SHP2抑制剂在小儿骨科中的转化潜力。
