Sirtuins as Metabolic Modulators of Muscle Plasticity

In skeletal muscle, imbalances in energy homeostasis or chronic insults of cellular stress have dramatic effects on bioenergetics through the alteration of cellular substrate use and/or changes in mitochondrial content and function. For example, cellular stress induced by exercise or caloric restriction can increase mitochondrial biogenesis and function as an adaptation to low energetic levels. In addition, with an increase in mitochondrial biogenesis comes an increased demand for oxygen delivery through the activation of angiogenesis. Over the last decade researchers have examined the involvement of sirtuin proteins, as metabolic sensors, to regulate these adaptations. Our review will therefore summarize the recent findings related to sirtuin-mediated responses to metabolic stress in skeletal muscle.