Plasticity of muscle stem cells in homeostasis and aging

We are living longer, but our healthspan has not increased. The goal of regenerative medicine is to increase quality of life through an understanding of the cellular and molecular processes that underlie effective tissue repair in order to restore damaged tissues. The drivers of muscle regeneration are the muscle stem cells that cycle between quiescent and activated states to meet tissue regenerative demands. Here we review recent findings on the role of the niche, or tissue microenvironment, in the modulation of muscle stem cell plasticity and the mechanisms responsible for the drastic loss of stem cell function with aging. These new studies unveil fundamental mechanisms of stem cell plasticity with broad relevance to other tissues and lay the foundation for the development of therapeutic strategies to boost the regenerative potential of aged muscle stem cells.