Send to

Choose Destination
J Biol Chem. 2012 Nov 2;287(45):37808-23. doi: 10.1074/jbc.M112.385369. Epub 2012 Sep 17.

Intracellular and extracellular ATP coordinately regulate the inverse correlation between osteoclast survival and bone resorption.

Author information

Department of Geriatric Medicine, Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology, Tokyo, Japan.


Osteoclasts, highly differentiated bone-resorbing cells of hematopoietic origin, have two conflicting tendencies: a lower capacity to survive and a higher capacity to execute energy-consuming activities such as bone resorption. Here, we report that when compared with their precursors, mature mitochondria-rich osteoclasts have lower levels of intracellular ATP, which is associated with receptor activator of nuclear factor κ-B ligand (RANKL)-induced Bcl-x(L) down-regulation. Severe ATP depletion, caused by disrupting mitochondrial transcription factor A (Tfam) gene, leads to increased bone-resorbing activity despite accelerated apoptosis. Although AMP-activated protein kinase (AMPK) activation by ATP depletion is not involved in the regulation of osteoclast function, the release of ATP from intracellular stores negatively regulates bone-resorbing activity through an autocrine/paracrine feedback loop by altering cytoskeletal structures. Furthermore, osteoclasts derived from aged mice exhibit reduced mitochondrial DNA (mtDNA) and intracellular ATP levels with increased bone-resorbing activity, implicating the possible involvement of age-related mitochondrial dysfunction in osteoporosis. Thus, our study provides evidence for a mechanism underlying the control of cellular functions by reciprocal changes in intracellular and extracellular ATP, which regulate the negative correlation between osteoclast survival and bone resorption.

[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for HighWire Icon for PubMed Central
Loading ...
Support Center