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Calcium signaling in osteoclast differentiation and bone resorption
1Department of Physiological Science and Molecular Biology, Fukuoka Dental College, Fukuoka 814-0133, Japan. kajiya@college.fdcnet.ac.jp
Advances in Experimental Medicine and Biology
|March 29, 2012
Summary
Calcium (Ca2+) signaling drives osteoclast differentiation via long-term oscillations but inhibits bone resorption in mature cells through short-term increases. This dual role is crucial for bone remodeling.
Area of Science:
- Cell Biology
- Biochemistry
- Physiology
Background:
- Calcium (Ca2+) signaling is vital for cellular functions.
- Osteoclast Ca2+ signals regulate differentiation, bone resorption, and gene transcription.
- Intracellular Ca2+ signaling is critical for osteoclast differentiation.
Purpose of the Study:
- To investigate the dual role of calcium (Ca2+) signaling in osteoclast differentiation and mature osteoclast function.
- To elucidate the mechanisms of Ca2+ regulation during osteoclastogenesis.
- To differentiate the effects of long-term Ca2+ oscillations versus short-term Ca2+ increases.
Main Methods:
- Analysis of Receptor activator of NF-κB ligand (RANKL) signaling pathways.
- Investigation of intracellular Ca2+ release and entry mechanisms (IP3 channels, SOCE, TRP V channels).
- Measurement of intracellular Ca2+ concentrations ([Ca2+]i) in response to various stimuli.
Main Results:
- RANKL signaling induces oscillatory Ca2+ changes, activating NFATc1 for osteoclast differentiation.
- RANKL-induced Ca2+ oscillations involve intracellular release and store-operated/TRP V channel entry.
- Elevated [Ca2+]i in mature osteoclasts inhibits motility and bone resorption.
Conclusions:
- Calcium (Ca2+) signaling differentially regulates osteoclast precursors and mature osteoclasts.
- Long-term Ca2+ oscillations promote osteoclast differentiation.
- Short-term Ca2+ increases suppress mature osteoclast resorption activity.
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