Experimental Study on the Inhibition of RANKL-Induced Osteoclast Differentiation In Vitro by Metformin Hydrochloride

Zhang Chen; Liu Zige; Yeow Sai Kiang; Chen Desheng

doi:10.1155/2022/6778332

Experimental Study on the Inhibition of RANKL-Induced Osteoclast Differentiation In Vitro by Metformin Hydrochloride

Int J Endocrinol. 2022 Sep 12:2022:6778332. doi: 10.1155/2022/6778332. eCollection 2022.

Authors

Zhang Chen¹, Liu Zige², Yeow Sai Kiang³, Chen Desheng⁴

Affiliations

¹ Department of Orthopedic Surgery, General Hospital of Ningxia Medical University, Yinchuan, China.
² School of Clinical Medicine, Guangxi Medical University, Nanning, China.
³ Department of Orthopedic Surgery, Sengkang General Hospital, Singapore.
⁴ Department of Orthopedic Surgery, People's Hospital of Ningxia Hui Autonomous Region, Yinchuan, China.

Abstract

Objective: Establishment of an in vitro osteoclast induction model under nuclear factor-κB receptor activator ligand (RANKL) induction for investigating the effect of metformin hydrochloride (Met) on osteoclast differentiation.

Methods: RANKL induced the differentiation of mouse bone marrow macrophages (BMMs) into osteoclasts in vitro, and Met was added at different concentrations for intervention during the induction process. After 5 d of culture and fixation, the number of osteoclasts was counted by tartrate-resistant acid phosphatase (TRAP) staining and F-actin staining, and the function of osteoclasts was examined with hydroxyapatite-coated plates. Real-time fluorescence quantitative PCR was performed to detect the expression of Cathepsin K, osteoclast associated receptor (OSCAR), and TRAP, and the effect of Met on Mitogen-activated protein kinases (MAPK) signaling pathway was detected by Western blot.

Results: Met significantly reduced osteoclast formation, F-actin ring formation, bone resorption, and the expression of relevant genes Cathepsin K, OSCAR, and TRAP. The Western blotting study demonstrated that Met inhibited the MAPK signaling pathway by decreasing the phosphorylation of extracellular regulated protein kinase (ERK), which plays important roles in osteoclast formation.

Conclusion: Metformin hydrochloride inhibited the differentiation of osteoclasts, decreased the bone resorption area, and suppressed phosphorylation of ERK in vitro.