How Aging Hurts Bone Healing
Via EurekAlert!: "Researchers have unraveled crucial details of how aging causes broken bones to heal slowly, or not at all, [and] also successfully conducted preclinical tests on a potential new class of treatments designed to 'rescue' healing capability lost to aging. ... COX-2 levels drop dramatically with age, and that the drop most explains why stem cells no longer turn into cartilage as efficiently, an early step in the chain reaction of healing. While a role for COX-2 in bone repair had been detailed prior to the current study, the cell populations responsible for the supply of COX-2 to the fracture callus, the layer of pre-cartilage cells (cartilage progenitors) that form first around a fracture to guide bone building, had not. The team also confirmed for the first time that healing ability lost with age can be rescued by manipulating the COX-2 pathway with existing, experimental drugs. The study was in mice, but is especially relevant to human medicine because of the similarity between human and mouse COX-2 gene."
Link: http://www.eurekalert.org/pub_releases/2009-01/uorm-rdh011509.php