Background: Skeletal muscle stem cells enable the formation, growth, maintenance, and regeneration of skeletal muscle throughout life. The regeneration process is compromised in several pathological conditions, and muscle progenitors derived from pluripotent stem cells have been suggested as a potential therapeutic source for tissue replacement. DNA methylation is an important epigenetic mechanism in the setting and maintenance of cellular identity, but its role in stem cell determination towards the myogenic lineage is unknown. Here we addressed the DNA methylation dynamics of the major genes orchestrating the myogenic determination and differentiation programs in embryonic stem (ES) cells, their Pax7-induced myogenic derivatives, and muscle stem cells in proliferating and differentiating conditions. Results: Our data showed a common muscle-specific DNA demethylation signature required to acquire and maintain the muscle-cell identity. This specific-DNA demethylation is Pax7-mediated, and it is a prime event in muscle stem cells gene activation. Notably, downregulation of the demethylation-related enzyme Apobec2 in ES-derived myogenic precursors reduced myogenin-associated DNA demethylation and dramatically impaired the expression of differentiation markers and, ultimately, muscle differentiation. Conclusions: Our results underscore DNA demethylation as a key mechanism driving myogenesis and identify specific Pax7-mediated DNA demethylation signatures to acquire and maintain the muscle-cell identity. Additionally, we provide a panel of epigenetic markers for the efficient and safe generation of ES- and induced pluripotent stem cell (iPS)-derived myogenic progenitors for therapeutic applications.
Bibliographical noteFunding Information:
We thank Irene López, Jessica Acosta, Dèlia Yubero and Ruth Montalbo for excellent technical assistance. We also thank Dr. Reuben Harris (University of Minnesota) for his advice on Apobec2 western blot. We are also grateful to Sonia Forcales for helpful discussions. E.C. is a FPI Fellow (MINECO). This work was supported by Ministerio de Economía y Competitividad (SAF2012-37427 to M.S., SAF2011-23638 and SAF2015-64521 to M.A.P.), Feder funds, Generalitat de Catalunya (2009 SGR1356 to M.A.P.), National Institutes of Health grant (R01 AR055299 (R.P.) and Minnesota Regenerative Medicine grant (MRM 2015 PDSCH 003 to A.M).
© 2016 Carrió et al.
- Cellular identity
- DNA methylation
- Pax7-induced ESCs