Loading...
Osteoporosis represents an imbalance: Bone resorption exceeds bone formation. No available treatments restore that balance. Potent agents that enhance bone formation (such as parathyroid hormone) also enhance bone resorption. Potent agents that discourage bone resorption (such as bisphosphonates) also discourage bone formation.
A Japanese team has identified a molecule, semaphorin 3A (Sema3A), that simultaneously promotes bone formation and inhibits bone resorption. After investigating this trait in vitro, the investigators created mice in which both copies of the gene for Sema3A were inactivated — such mice are severely osteopenic. Finally, intravenous administration of Sema3A to such mice enhanced bone volume and promoted bone regeneration…