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Updated: Jun 24, 2026
09:37
A RANKL-based Osteoclast Culture Assay of Mouse Bone Marrow to Investigate the Role of mTORC1 in Osteoclast Formation
Published on: March 15, 2018
Commitment to the osteoblast lineage is not required for RANKL gene expression
Carlo Galli1, Qiang Fu, Wenfang Wang
1Center for Osteoporosis and Metabolic Bone Diseases, University of Arkansas for Medical Sciences, and Central Arkansas Veterans Healthcare System, Little Rock, AR 72205, USA.
The Journal of Biological Chemistry
|March 13, 2009
Summary
Osteoclast differentiation requires RANKL from stromal cells. Osteoblast lineage commitment is not essential for RANKL gene expression but may enhance hormonal responses by regulating hormone receptors.
Area of Science:
- Bone biology
- Cell signaling
- Endocrinology
Background:
- Osteoclast differentiation depends on RANKL expressed by stromal cells, potentially of osteoblast lineage.
- Previous work suggested Runx2 transcription factor involvement in RANKL regulation.
Purpose of the Study:
- To investigate the role of osteoblast lineage commitment in RANKL expression and hormonal responsiveness.
- To determine if transcription factors Runx2 and osterix influence RANKL regulation by parathyroid hormone (PTH).
Main Methods:
- Studied RANKL expression in mice with reduced osteoblast numbers.
- Utilized fibroblastic stromal cell models to assess basal and PTH-stimulated RANKL expression.
- Examined the effect of osterix expression on RANKL responsiveness to PTH and vitamin D.
Main Results:
- PTH-stimulated RANKL expression was unaffected by reduced osteoblast numbers.
- Runx2 and Cbfb were not required for basal or PTH-stimulated RANKL expression.
- Osterix elevated RANKL responsiveness to PTH, linked to increased PTH receptor expression.
Conclusions:
- Commitment to the osteoblast lineage is not necessary for RANKL gene transcription in stromal cells.
- Osteoblast differentiation factors may enhance hormonal responsiveness of RANKL by modulating hormone receptor levels.
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