Researchers from the University of Sydney in Australia published an article in "The Journals of Gerontology" in February 2023, stating that NMN can delay the aging of human bone cells and promote bone healing in osteoporotic mice.
This paves the way for NMN as an effective improvement method for osteoporosis. As the researchers stated: "This study demonstrates that NMN is an effective and feasible method to prevent osteoporosis and improve bone healing in older adults with osteoporosis."
Joints are composed of articular surfaces, joint capsules, and joint cavities. A fracture refers to a trauma in which a bone is broken, broken or cracked under the action of external force.
When a fracture occurs, special stem cells in the bone marrow work through multiple stages to repair and heal the fracture.
These special stem cells, called bone marrow mesenchymal stem cells (BMSCs), are self-regenerative cells capable of differentiating into multiple types of cells, such as osteoblasts and adipocytes, which are key to bone regeneration.
Delayed fracture healing or even healing failure is often caused by low activity or dysfunction of BMSCs.
The effects of NMN on osteoporosis were studied by studying human bone-forming cells. To induce senescence, the researchers exposed bone-forming cells to an inflammatory factor called TNF-LMAR.
Although TNF-apical senescence is elevated, NMN reduces this senescence nearly 3-fold, suggesting that NMN reduces senescent osteoblasts.
Healthy osteoblasts form new bone tissue by converting into mature bone cells (osteoblasts).
△NMN promotes bone formation, and the reduction of osteoblasts induced by TNF-α is offset by NMN (TNF-α+NMN)
The researchers found that senescence-inducing TNF-telomeres reduced the number of mature bone cells. However, NMN increased the number of mature osteocytes, suggesting that NMN promotes bone formation.
NMN promotes bone formation. Reduction of inflammatory bone formation (hisalin red stained area) induced in TNF- mice was counteracted by NMN (TNFI+NMN).
After determining that NMN reduced senescent bone-forming cells and promoted their differentiation into mature bone cells, the researchers tested whether this would occur in living organisms.
△The bone accumulation (BV/TV) of untreated osteoporotic mice (control) was lower than that of NMN-treated osteoporotic mice.
To do this, they removed the ovaries of female mice and broke their femoral bones, which caused a reduction in bone volume, an indicator of osteoporosis.
To test the effects of NMN on osteoporotic mice, the researchers injected osteoporotic mice with 400 mg/kg/day of NMN for 2 months.
As a result, the bone volume of osteoporotic mice increased, suggesting that NMN partially reverses the symptoms of osteoporosis. Combined with the human osteoblast data, this means NMN could treat osteoporosis by increasing bone formation.
Reference: Lu, ZuFu et al. "Nicotinamide Mononucleotide Alleviates Osteoblast Senescence Induction and Promotes Bone Healing in Osteoporotic Mice." The journals of gerontology. Series A, Biological sciences and medical sciences vol. 78,2 (2023): 186-194 . doi:10.1093/gerona/glac175.