Quercetin Promotes Production of Secondary Hair Follicle Stem Cells in Cashmere Goat: A Mechanistic Study

This study investigated the effects of quercetin on the proliferation and apoptosis of secondary hair follicle stem cells (SHFSCs) isolated from Arbas cashmere goats. SHFSCs were treated with varying quercetin concentrations. Treatment with 10 μg/mL quercetin for 48 h significantly promoted cell proliferation. CCK-8, EdU assays, and flow cytometry analyses indicated enhanced cell viability, with the proportion of S-phase cells increasing from 15.5% to 21.2%. The mRNA expression levels of prolifer-ation markers PCNA and TERT and their corresponding protein levels were upregu-lated. Additionally, quercetin inhibited cell apoptosis, as evidenced by the downregu-lation of the pro-apoptotic genes BAX, TP53, and CASP3, upregulation of the an-ti-apoptotic gene BCL-2, and a reduced number of late apoptotic cells. Mechanistically, quercetin activated the PI3K–Akt, Wnt, and TGF-β signaling pathways, upregulated the expression of cell cycle genes (CCND1 and CDK4), and improved cellular energy metabolism and antioxidant status by enhancing mitochondrial membrane potential, reducing reactive oxygen species levels, and promoting the secretion of growth factors (VEGF/FGF/HGF). Transcriptome analyses revealed that differentially expressed genes (DEGs) were enriched in translational processes, insulin-like growth factor binding, and proliferation-related signaling pathways. Quercetin therefore promotes SHFSC proliferation through multiple pathways, providing a regulatory strategy for improv-ing cashmere production from goats.