Abstract：
Multiple regulatory mechanisms are in place to ensure the normal processes of bone metabolism, encompassing both bone formation and absorption. This study has identified chaperone-mediated autophagy (CMA) as a critical regulator that safeguards bone formation from the detrimental effects of excessive inflammation. By silencing LAMP2A or HSCA8, we observed a hindrance in the osteoblast differentiation of human bone marrow mesenchymal stem cells (hBMSCs) in vitro. To further elucidate the role of LAMP2A, we generated LAMP2A gene knockdown and overexpression of mouse BMSCs (mBMSCs) using adenovirus. Our results showed that LAMP2A knockdown led to a decrease in osteogenic-specific proteins, while LAMP2A overexpression favored the osteogenesis of mBMSCs. Notably, active-β-catenin levels were upregulated by LAMP2A overexpression. Furthermore, we found that LAMP2A overexpression effectively protected the osteogenesis of mBMSCs from TNF-α, through the PI3K/AKT/GSK3β/β-catenin pathway. Additionally, LAMP2A overexpression significantly inhibited osteoclast hyperactivity induced by TNF-α. Finally, in a murine bone defect model, we demonstrated that controlled release of LAMP2A overexpression adenovirus by alginate sodium capsule efficiently protected bone healing from inflammation, as confirmed by imaging and histological analyses. Collectively, our findings suggest that enhancing CMA has the potential to safeguard bone formation while mitigating hyperactivity in bone absorption.
摘要：
多种调节机制到位，以确保骨代谢的正常过程，包括骨形成和吸收。这项研究已经确定了伴侣介导的自噬（CMA）作为保护骨形成免受过度炎症的有害影响的关键调节因子。通过沉默LAMP2A或HSCA8，我们观察到人骨髓间充质干细胞（hBMSCs）在体外的成骨细胞分化障碍。为了进一步阐明LAMP2A的作用，我们使用腺病毒产生了小鼠BMSCs（mBMSCs）的LAMP2A基因敲低和过表达。我们的结果表明LAMP2A敲低导致成骨特异性蛋白的减少，而LAMP2A过表达有利于mBMSCs的成骨。值得注意的是,LAMP2A过表达上调活性β-连环蛋白水平。此外，我们发现LAMP2A过表达能有效保护mBMSCs从TNF-α,通过PI3K/AKT/GSK3β/β-catenin途径。此外,LAMP2A过表达显著抑制TNF-α诱导的破骨细胞过度活动。最后,在鼠骨缺损模型中，我们证明了通过海藻酸钠胶囊控制释放LAMP2A过表达腺病毒有效保护骨愈合免受炎症,如影像学和组织学分析所证实。总的来说，我们的研究结果表明,增强CMA有可能保护骨形成,同时减轻骨吸收过度活跃.
