Role of autophagy in bone and muscle biology.

Autophagy in eukaryotic cells is a constitutive process and functions as a homeostatic mechanism; it is upregulated in response to specific stress stimuli such as starvation, hypoxia and as oxidative stress. In addition to playing a crucial role in adaptive responses to different stimuli, autophagy is also required for intracellular quality control. This second aspect is important to prevent the activation of pathological processes. Autophagy also plays a central role in cellular development and differentiation because it is involved in the regulation of energetic balance. This final aspect is critical for maintaining proper bone and muscle function as well as to prevent any pathological changes. Therefore, identifying new molecular targets involved in autophagy is critical to assure a good quality of life.