Fig. 4.

Impact of muscle contraction platelet-derived growth factor receptor-α-positive lineage-negative (PDGFα⁺Lin⁻) fibroadipogenic progenitor (FAP) cell gene expression. Mice (15-to 17 wk old) were subjected to a single bout of electrical stimulation (e-stim). Gastrocnemius-soleus complexes were harvested and processed 3 h (A) and 24 h (B) post e-stim for isolation of FAPs by FACS and targeted analysis of gene expression using quantitative PCR. Genes are categorized by function, including factors related to tissue growth vascular remodeling (GF/VAS), extracellular matrix remodeling (ECM), myogenesis (MYO), fibroadipogenesis (ADIPO), and neurogenic support (NEURO). Values are means ± SE (n = 3–6). *P < 0.05 vs. sham.