Researchers from UC San Francisco and UC Davis have made a significant breakthrough in understanding why breastfeeding women maintain strong bones despite losing calcium to milk production. Their discovery of a hormone, now termed Maternal Brain Hormone (CCN3), could potentially revolutionize treatment for osteoporosis and bone fractures worldwide.
Published in Nature on July 10, their study addresses a long-standing puzzle in women’s health. Despite lowered estrogen levels during breastfeeding, which typically increase the risk of osteoporosis post-menopause, breastfeeding women rarely experience bone fractures. This anomaly suggested an alternative mechanism promoting bone health.
Lead researcher Dr. Holly Ingraham and her team initially identified CCN3’s role in increasing bone density and strength in female mice. The hormone, originally overlooked due to its atypical secretion profile from neurons, was pinpointed after an exhaustive search. Further experiments confirmed CCN3’s presence in lactating female mice’s brains, crucial for maintaining bone health during lactation.
Dr. Thomas Ambrosi of UC Davis, a collaborator on the study, highlighted CCN3’s unique ability to enhance bone strength without the typical brittleness associated with highly mineralized bones. Their findings showed that CCN3 stimulates stem cells responsible for bone regeneration, prompting new bone cell generation.
Excitingly, their research extended beyond lactation benefits. In elderly mice, application of a CCN3-releasing hydrogel patch at fracture sites significantly improved bone healing—an outcome previously unattainable with other methods.
Looking ahead, the team plans to delve into CCN3’s molecular mechanisms and its potential applications in treating various bone-related conditions. Dr. Muriel Babey, co-first author, expressed interest in exploring CCN3’s impact on bone metabolism across different clinical contexts, supported by UCSF’s Catalyst program.
Dr. Ingraham emphasized CCN3’s potential to address bone loss not only in post-menopausal women but also in breast cancer survivors and elderly men at risk of fractures. The hormone’s ability to enhance bone mass opens doors for novel therapeutic interventions in bone health.
As research progresses, the team aims to uncover more about CCN3’s efficacy and safety in clinical settings, offering hope for improved treatments in bone-related diseases worldwide.
