How Physical Activity across the Lifespan Can Reduce the Impact of Bone Ageing: A Literature Review

Bone remodeling is a lifelong process, due to the balanced activity of the osteoblasts (OBs), the bone-forming cells, and osteoclasts (OCs), the bone-resorbing cells. This equilibrium is mainly regulated by the WNT-ß-cathenin pathway and the RANK-RANKL/OPG system, respectively. Bone ageing is a process which normally occurs during life due to the imbalance between bone formation and bone resorption, potentially leading to osteoporosis. Bone loss associated with bone ageing is determined by oxidative stress, the result of the increasing production of reactive oxygen species (ROS). The promotion of physical exercise during growth increases the chances of accruing bone and delaying the onset of osteoporosis. Several studies demonstrate that physical exercise is associated with higher bone mineral density and lower fracture incidence, and the resulting bone mineral gain is maintained with ageing, despite a reduction of physical activity in adulthood. The benefits of exercise are widely recognized, thus physical activity is considered the best non-pharmacologic treatment for pathologies such as osteoporosis, obesity, diabetes and cardiovascular disease. We reviewed the physiological mechanisms which control bone remodeling, the effects of physical activity on bone health, and studies on the impact of exercise in reducing bone ageing.

Senescent Cells in Early Vascular Ageing and Bone Disease of Chronic Kidney Disease—A Novel Target for Treatment

Together with bone-mineral disorders, premature vascular ageing is a common feature of the uremic phenotype. A detailed understanding of mechanisms involved remains unclear and warrants further research. Available treatment options for end stage renal disease are principally dialysis and organ transplantation, as other treatment alternatives have proven insufficient. Chronic kidney disease (CKD) has been proposed as a model of early vascular and bone ageing, with accumulating evidence supporting the contribution of cellular senescence and the senescence-associated secretory phenotype (SASP) to cardiovascular pathology in CKD. Correspondingly, novel therapies based around the use of senolytic compounds and nuclear factor-erythroid-2-related factor 2 (Nrf2) agonists, have been suggested as attractive novel treatment options. In this review, we detail the contribution of the uremic environment to these processes underpinning ageing and how these relate to vascular health.

Collagen/Polyurethane-Coated Bioactive Glass: Early Achievements towards the Modelling of Healthy and Osteoporotic Bone

The development of suitable strategies to treat ageing-related pathologies has attracted the interest of researchers in view of the increasing life expectancy in the next decades. Osteoporosis is a worldwide disease with high prevalence in humans older than 50 that dramatically increases the risk of bone fractures with associated disabilities. The innovative use of new biomaterials as models of the healthy and osteoporotic bone matrix would be a new strategy to study the physiological conditions associated with osteoporosis and the connection between microenvironment changes and the bone ageing process. In this work, experimental bioactive glass substrates were coated with various polymer formulations in order to impart tunable surface features to the whole systems, which will act as models of the healthy and aged bone tissue once they have been colonized by cells.