Microenvironment Mimicry

Muscle stem cells cultured in vitro retain regenerative ability when conditions reflect the physical nature of their in vivo environment. Stem cells define their physiological homes, or niches, as the place of residence where they self-renew and differentiate ( 1 ), supporting growth, homeostasis, and tissue-regenerative response upon injury and disease ( 2 ). On page 1078 of this issue, Gilbert et al. ( 3 ) remind us that home is not merely a location, but also a specialized physical environment that modulates cell behavior. The authors show that muscle stem cells derived from mice retain their regenerative properties in cell culture as long as the elastic comforts of their physiological niche are duplicated. Thus, mimicking the biophysical properties of a niche may be equally important to other stem cell types.