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Updated: Dec 26, 2025
A RANKL-based Osteoclast Culture Assay of Mouse Bone Marrow to Investigate the Role of mTORC1 in Osteoclast Formation
Published on: March 15, 2018
Endogenous parathyroid hormone (PTH) signals through osteoblasts via RANKL during fracture healing to affect
Peng Sun1, Ming Wang2, Guo-Yong Yin3
1Department of Orthopedics, The Affiliated Huaian No.1 People's Hospital of Nanjing Medical University, Huaian, Jiangsu, 223300, China.
Aim:
To investigate the effect of endogenous PTH deficiency on osteoclasts during fracture healing and its mechanism.
Methods:
A femoral fracture model was used to determine the role of endogenous PTH in fracture healing. Immunohistochemistry, qPCR, and Western blot were used to determine the potential functions and mechanisms of endogenous PTH.
Result:
In this study, we found that expression of RANKL and CK was lower in PTH knockout (KO) mice than in wild type (WT) mice. In vitro culture of osteoclasts showed that under the same stimulation, there was no statistical difference in the number of osteoclasts and the area of bone resorption areas in PTH WT mice and PTH KO mice. We found that a high concentration of RANKL could promote the number and activity of osteoclasts. Upon induction of osteoblasts in vitro, those from the PTH WT group expressed higher RANKL protein and mRNA than those from the PTH KO group. Lastly, we confirmed that the PI3K/AKT/STAT5 pathway promotes RANKL increase from osteoblasts.
Conclusion:
During fracture healing, endogenous PTH deficiency can affect osteoclast activity by reducing RANKL expression in osteoblasts.
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