1. Chaperone-mediated autophagy protects the bone formation from excessive inflammation through PI3K/AKT/GSK3β/β-catenin pathway.
- Author
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Hang K, Wang Y, Bai J, Wang Z, Wu W, Zhu W, Liu S, Pan Z, Chen J, and Chen W
- Subjects
- Animals, Mice, Humans, Signal Transduction, Male, Mice, Inbred C57BL, Osteoblasts metabolism, Cell Differentiation, Osteoclasts metabolism, Osteogenesis physiology, Glycogen Synthase Kinase 3 beta metabolism, Glycogen Synthase Kinase 3 beta genetics, Proto-Oncogene Proteins c-akt metabolism, Phosphatidylinositol 3-Kinases metabolism, beta Catenin metabolism, Chaperone-Mediated Autophagy, Mesenchymal Stem Cells metabolism, Inflammation metabolism, Lysosomal-Associated Membrane Protein 2 metabolism, Lysosomal-Associated Membrane Protein 2 genetics
- 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., (© 2024 Federation of American Societies for Experimental Biology.)
- Published
- 2024
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