Nestin-GFP reporter expression defines the quiescent state of skeletal muscle satellite cells

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ydbio.2006.12.026 Byline: Kenneth Day (a), Gabi Shefer (a), Joshua B. Richardson (a), Grigori Enikolopov (c), Zipora Yablonka-Reuveni (a)(b) Keywords: Satellite cells; Self-renewal; Stem cells; Endothelial cells; Nestin; Desmin; Myf5; Pax3; Pax7; Sca1; CD31; GFP; Sca1-GFP; Nestin-GFP Abstract: Repair of adult skeletal muscle depends on satellite cells, quiescent myogenic stem cells located beneath the myofiber basal lamina. Satellite cell numbers and performance decline with age and disease, yet the intrinsic molecular changes accompanying these conditions are unknown. We identified expression of GFP driven by regulatory elements of the nestin (NES) gene within mouse satellite cells, which permitted characterization of these cells in their niche. Sorted NES-GFP.sup.+ cells exclusively acquired a myogenic fate, even when supplemented with media supporting non-myogenic development. Mutual and unique gene expression by NES-GFP.sup.+ cells from hindlimb and diaphragm muscles demonstrated intra- and inter-muscular heterogeneity of satellite cells. NES-GFP expression declined following satellite cell activation and was reacquired in late stage myogenic cultures by non-proliferating Pax7.sup.+ progeny. The dynamics of this expression pattern reflect the cycle of satellite cell self-renewal. The NES-GFP model reveals unique transcriptional activity within quiescent satellite cells and permits novel insight into the heterogeneity of their molecular signatures. Author Affiliation: (a) Department of Biological Structure, University of Washington School of Medicine, Seattle, WA 98195, USA (b) Institute for Stem Cell and Regenerative Medicine, University of Washington School of Medicine, Seattle, WA 98195, USA (c) Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA Article History: Received 25 August 2006; Revised 7 November 2006; Accepted 12 December 2006