Mitochondrial dynamics maintain stem cell regenerative competence throughout adult life by regulating metabolism and mitophagy. Mitochondrial dynamics maintain stem cell regenerative competence throughout adult life by regulating metabolism and mitophagy

We profiled by bulk RNA-seq the transcriptional changes upon deletion of Drp1 in murine satellite cells, freshly harvested from young and old homeostatic muscle and during regeneration, after acute cardiotoxin-induced myoinjury Overall design: Hindlimb skeletal muscles from tamoxifen-treated WT ( Pax7-CreER; ROSA26YFP) and conditional Drp1-KO (Pax7-CreER;ROSA26YFP;Drp1fl/fl) mice were collected, manually minced, and mechano-enzymatically dissociated with Liberase/Dispase for 1-1.5 hours at 37ºC. Tissue homogenates were filtered and red blood cells lysed. The final single-suspension cell pellets were stained and processed for FACS-sorting to isolate highly purified satellite cells based on YFP+ expression (QSC, quiescent satellite cells). Concurrently pre-injured (tibialis anterior, quadriceps, and gastrocnemius) muscles, were also harvested from equivalent groups of genotype- and age-matched animals at 1-day ('Activated' satellite cells, ASC) or 3-days ('Proliferating' satellite cells) post-cardiotoxin-injection (DPI). For these timepoint conditions, cells were FACS-sorted from the regenerating bulk homogenates based on YFP+ (1DPI) or CD34-YFP+ (3DPI) immunophenotypes. Ages for the Young and the Old animal groups were 3 and 24 months, respectively.