Not etched in bone: the role of osteoclast proton-sensing receptors.

The osteoclast proton-sensing receptors may play a role in osteoclastogenesis or bone resorption. The current study by Kreiger et al. found that in female mice, osteoclast-specific deletion of the gene for OGR1 resulted in increased bone mass, which demonstrates that in some situations this receptor is playing a role. However, there are some inconsistencies because the bone resorption was not reduced in their global knockout mice, and the effects are not seen in both genders or by other investigators. More work should be done to better define the role of OGR1 because acidosis is an important cause of bone loss.