Inflamm-aging' Causes Loss of Bone Healing Ability in Seniors

A study published in the Proceedings of the National Academy of Sciences suggests flare-ups in chronic inflammation are mainly responsible for why injured bones do not heal as well with age, reports ScienceDaily . According to the researchers, exposing stem cells from young mice to the blood serum of older mice made their stem cells four times less likely to divide and multiply, via indirect activation of a key immune-related protein, NF?B. Previous studies also showed senescent stem cells send signals that encourage chronic inflammation. In addition, treatment over time with sodium salicylate, an ingredient in aspirin, repressed NF?B signals and related aged-induced chronic inflammation, enlarging the number and bone-healing contribution of skeletal stem cells. "These results suggest that it is inflammation, not chronological age, that hinders bone healing in seniors," says New York University School of Medicine's Anne Marie Josephson. She notes a barrier to the translation of the findings into future treatments is that revitalizing bone stem cells with anti-inflammatory drugs just after a fracture would also inhibit the acute inflammation necessary for successful bone healing.