Role of oxidative stress in bone ageing

Abstract

Oxidative stress (OS) plays a major role in ageing process. Aerobic metabolism involves the production of reactive oxygen species (ROS) whose accumulation produces irreversible cell damage. Nature has developed various antioxidant mechanisms as defence against oxidative stress, but their efficacy decreases with ageing, which leads to homeostasis alterations. There is evidence showing that OS plays a major role in the development of age-related osteopenia. In bone, loss of oestrogen production and chronic illnesses such as diabetes mellitus contribute to the increased ROS levels with age. However, typical antioxidants such as N -acetyl cysteine or catalase are not effective to prevent the deleterious effects of high OS in this tissue, probably due to their concomitant anti-remodelling action. Of interest, it has very recently been reported that parathyroid hormone, the only currently available anabolic agent for osteoporosis, exerts various osteogenic effects including anti-OS features. Unravelling the mechanisms underlying the increase of OS and its relation to bone loss with age would be important to design novel strategies to prevent the development of osteoporosis in ageing subjects.