Italian Journal of Anatomy and Embryology - contenuto non piu disponibile

It has been recently reported that, after physical exercise activity, the skeletal muscle releases Irisin, the newly identified myokine able of driving transition of white adipocytes into brown, following a phenomenon known as the browning response. This result suggested that skeletal muscle is crucial in the regulation of energy homeostasis, supporting its role as endocrine organ that targets adipose tissue by promoting energy expenditure. In accordance with this new finding, we demonstrated that conditioned media (CM) collected from primary myoblasts of exercised mice were able to induce osteoblast differentiation in a greater extent than those of mice housed in resting conditions and this effect is Irisin-mediated. In view of further proving the involvement of Irisin in bone metabolism, we validate its direct effect on osteoblasts by using r-Irisin. Here we show that phosphorylation of MAP kinase ERK and expression of Atf 4 (p