Bulk RNAseq of mononucleated cells isolated from resting and regenerating adult and aged skeletal mouse muscle
Muscle regeneration is impaired in the aged organism, due to both intrinsic defects of muscle stem cells (MuSCs) and alterations of their environmental niche. However, the latter has still been poorly explored. Here, we compared and analyzed the time course of the various cell types constituting the MuSC niche during muscle generation in young and old mice. Aging altered the amplification of all niche cells with particularly prominent phenotypes in macrophages that impaired the resolution of inflammation in the old regenerating muscle. RNAsequencing of FACs-isolated MuSCs and non-myogenic niche cells during  regeneration uncovered specific profiles and kinetics of genes and molecular pathways differentially regulated in old versus young regenerating muscle, indicating that each cell type responded to aging in a specific manner. These data provide a unique resource to study the aging of the MuSC niche. Overall design: Adult (3 months) and aged (22-24 months) WT C57/B6 mice were subjected to a skeletal muscle injury and the mononucleated cells (muscle stem cells, fibroadipogenic precursor cells, endothelial cells, neutrophils, macrophages) were FACS-isolated at 0, 2, 4, and 7 days post injury and were proceed for bulk RNASeq