Regulation of osteoblast autophagy based on PI3K/AKT/mTOR signaling pathway study on the effect of β-ecdysterone on fracture healing

Journal of Orthopaedic Surgery and Research

Yanghua Tang¹  Linru Zeng¹  Yafeng Mo¹  Dawei Xin¹  Zhenfei Xiong¹  Gan Luo¹  Yanguang Cao² 

[1] Department of Orthopedics, Hospital of Traditional Chinese Medicine of Xiaoshan District, No. 156, Yucai Road, Xiaoshan District, Hangzhou City, Zhejiang Province, China;Department of Orthopedics, The Second Affiliated Hospital of Zhejiang Chinese Medical University, No. 318, ChaoWang Road, Gongshu District, Hangzhou City, Zhejiang Province, China;

关键词: β-Ecdysterone;    Autophagy;    Fracture healing;    mTOR;    Rapamycin;    AKT;   

DOI  :  10.1186/s13018-021-02862-z

来源: Springer

【 摘 要 】

ObjectivesTo investigate the effects of β-ecdysterone on fracture healing and the underlying mechanism.MethodsMTT assay was used to detect the cell viability. AO/PI and flow cytometry assays were used to determine the apoptotic rate. The expression level of RunX2, ATG7 and LC3 was evaluated by qRT-PCR and Western blot assays. X-ray and HE staining were conducted on the fractured femur. Immunohistochemical assay was used to detect the expression level of Beclin-1 and immunofluorescence assay was used to measure the expression level of LC3 in the fractured femurs. Western blot was utilized to determine the expression level of PI3K, p-AKT1, AKT1, p-mTOR, mTOR, p-p70S6K, and p70S6K.ResultsThe ALP activity and the expression of RunX2 in fractured osteoblasts were significantly elevated, the apoptotic rate was suppressed by rapamycin, 60, and 80 μM β-ecdysterone. The state of autophagy both in fractured osteoblasts and femurs was facilitated by rapamycin and β-ecdysterone. Compared to control, Garrett score was significantly promoted in rapamycin and β-ecdysterone groups, accompanied by ameliorated pathological state. Lastly, the PI3K/AKT/mTOR pathway both in fractured osteoblasts and femurs was inhibited by rapamycin and β-ecdysterone.Conclusionβ-ecdysterone might facilitate fracture healing by activating autophagy through suppressing PI3K/AKT/mTOR signal pathway.

【 授权许可】

CC BY