Bone is constantly being broken down and remodeled. Osteoporosis results when bone resorption outpaces bone regeneration. Production of reactive oxygen species, a form of oxidative stress, has been predicted to promote bone loss, but a source of reactive oxygen is unknown.

In this issue of the Journal of Clinical Investigation, Katrin Schröder and colleagues at Goethe-University identify a relationship between NADPH oxidase 4 (NOX4), an enzyme that promotes formation, and resorption. In a mouse model of osteoporosis, genetic disruption or drug-induced loss of NOX4 protected the mice from bone loss.

Additionally, the authors identify a small nuclear polymorphism in NOX4 in human patients that associated with increased bone turnover. Together, these data suggest treatments targeting NOX4 activity may benefit osteoporosis patients.

More information: NADPH oxidase 4 limits bone mass by promoting osteoclastogenesis, J Clin Invest. DOI: 10.1172/JCI67603

Journal information: Journal of Clinical Investigation