BACKGROUND Cartilage repair has been a challenge in the field of orthopaedics for decades, highlighting the significance of investigating potential therapeutic drugs. In this study, we explored the effect of the SHP2 inhibitor SHP099, a small-molecule drug, on cartilage repair. METHODS Human synovial mesenchymal stem cells (SMSCs) were isolated, and their three-way differentiation potential was examined. After treatment with chondrogenic medium, the chondrogenic effect of SHP099 on SMSCs was examined by western blot, qPCR, and immunofluorescence (IF). Micro-mass culture was also used to detect the effect of SHP099. To explore the chondrogenic effects of SHP099 in vivo, full-thickness cartilage defects with microfractures were constructed in the right femoral trochlea of New Zealand White rabbits. Intraarticular injection of SHP099 or normal saline was performed twice a week for 6 weeks. Cartilage repair was evaluated by haematoxylin and eosin (HE) staining and safranin O/fast green staining. Immunohistochemistry (IHC) for collagen II (COL2) was also conducted to verify the abundance of cartilage extracellular matrix after SHP099 treatment. The mechanism involving yes-associated protein (YAP) and WNT signalling was investigated in vitro. RESULTS SMSCs isolated from human synovium have optimal multi-differentiation potential. SHP099 increased chondrogenic marker (SOX9, COL2) expression and decreased hypertrophic marker (COL10, RUNX2) expression in SMSCs. In micro-mass culture, the SHP099-induced cartilage tissues had a better result of Safranin O and Toluidine blue staining and are enriched in cartilage-specific collagen II. Inhibition of YAP and WNT signalling was also observed. Moreover, compared to the normal saline group at 6 weeks, intraarticular injection of SHP099 resulted in better defect filling, forming increased hyaline cartilage-like tissue with higher levels of glycosaminoglycan (GAG) and COL2. CONCLUSION SHP099 promotes the repair of rabbit full-thickness cartilage defects, representing a potential therapeutic drug for cartilage repair. THE TRANSLATIONAL POTENTIAL OF THIS ARTICLE This study provides evidence that SHP2 inhibition promotes chondrogenesis and the repair of cartilage in defect area, which could be a novel therapeutic approach for cartilage repair.

中文翻译：

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SHP2抑制剂SHP099关节内注射促进兔全层软骨缺损修复。

背景软骨修复几十年来一直是骨科领域的挑战，突出了研究潜在治疗药物的重要性。在这项研究中，我们探讨了小分子药物 SHP2 抑制剂 SHP099 对软骨修复的影响。方法分离人滑膜间充质干细胞（SMSCs），检测其三向分化潜能。用成软骨培养基处理后，通过蛋白质印迹、qPCR 和免疫荧光 (IF) 检查 SHP099 对 SMSCs 的成软骨作用。微量培养也用于检测 SHP099 的效果。为了探索 SHP099 在体内的软骨形成作用，在新西兰白兔的右股骨滑车中构建了具有微骨折的全层软骨缺损。每周两次进行关节内注射 SHP099 或生理盐水，持续 6 周。通过苏木精和伊红（HE）染色和番红O/固绿染色评估软骨修复。还进行了胶原蛋白 II (COL2) 的免疫组织化学 (IHC) 以验证 SHP099 处理后软骨细胞外基质的丰度。在体外研究了涉及yes相关蛋白（YAP）和WNT信号传导的机制。结果 从人类滑膜中分离出的 SMSCs 具有最佳的多分化潜能。SHP099 增加了 SMSCs 中软骨形成标志物（SOX9、COL2）的表达并降低了肥大标志物（COL10、RUNX2）的表达。在微量培养中，SHP099 诱导的软骨组织具有更好的番红 O 和甲苯胺蓝染色结果，并且富含软骨特异性胶原蛋白 II。还观察到对 YAP 和 WNT 信号传导的抑制。此外，与生理盐水组在 6 周时相比，关节内注射 SHP099 导致更好的缺损填充，形成增加的透明软骨样组织，具有更高水平的糖胺聚糖 (GAG) 和 COL2。结论 SHP099促进兔全层软骨缺损的修复，是一种潜在的软骨修复治疗药物。本文的翻译潜力 本研究提供的证据表明，SHP2 抑制可促进软骨形成和缺损区域软骨的修复，这可能是一种新的软骨修复治疗方法。形成具有更高水平的糖胺聚糖（GAG）和COL2的增加的透明软骨样组织。结论 SHP099促进兔全层软骨缺损的修复，是一种潜在的软骨修复治疗药物。本文的翻译潜力 本研究提供的证据表明，SHP2 抑制可促进软骨形成和缺损区域软骨的修复，这可能是一种新的软骨修复治疗方法。形成具有更高水平的糖胺聚糖（GAG）和COL2的增加的透明软骨样组织。结论 SHP099促进兔全层软骨缺损的修复，是一种潜在的软骨修复治疗药物。本文的翻译潜力 本研究提供的证据表明，SHP2 抑制可促进软骨形成和缺损区软骨的修复，这可能是一种新的软骨修复治疗方法。