Antisenescence therapies for age-related bone loss: Target factors, medicines, biomedical materials

Progress in living conditions and medical technology have extended the human life span such that population aging, and thus the development of multi-system degenerative diseases, has become a major problem in many countries. Bone is a metabolically dynamic tissue and bone aging is closely related to a shift in the balance between bone resorption and bone formation. The resulting loss of bone mass and bone mechanical properties in older adults place them at risk of injury and premature death. Cellular senescence occurs in response to endogenous and exogenous stresses that lead to permanent cell cycle arrest and, thus, to tissue degeneration and dysfunction. Senescence in the bone microenvironment, as occurs during aging, induces a decline in bone formation. Research into the treatment of bone aging has therefore focused on the senescence process. This review begins with a summary of the key events in cellular senescence and bone aging and then examines recent progress in the targeting of cellular senescence, both to treat aging-related bone diseases. Novel therapeutic agents, natural products, and innovative biomedical materials are considered. Our discussion concludes by considering areas of future research.