The transcription factor NF-Y participates in stem cell fate decision and regeneration in adult skeletal muscle

The transcription factor NF-Y promotes cell proliferation and often loses its activity during differentiation through the regulation of NF-YA, the DNA binding subunit of the complex. In stem cell compartments, the shorter NF-YA splice variant (NF-YAs) is abundantly expressed and sustains their expansion. Here, we report that satellite cells, the stem cell population of adult skeletal muscle necessary for its growth and regeneration, express uniquely the longer NF-YA isoform (NF-YAl), majorly associated with cell differentiation. Through the generation of a conditional knock out mouse model that selectively ablates NF-YA in satellite cells, we demonstrate that NF-YA expression, and hence NF-Y activity, is fundamental to preserve the pool of muscle stem cells. Moreover, NF-Y supports their commitment to differentiation and ensures robust regenerative response to muscle injury. Gene expression profiling highlights an unexpected role for NF-Y in stem cell biology and opens a new scenario for NF-Y activity that is dispensable for muscle stem cell proliferation but required for efficient myogenic differentiation. Expression profile of Muscle Satellite Cells in NF-YA cell-specific conditional Knock Out Mice.