Cutaneous Consequences of Inhibiting EGF Receptor Signaling In Vivo: Normal Hair Follicle Development, But Retarded Hair Cycle Induction and Inhibition of Adipocyte Growth in EgfrWa5 Mice

The study investigated the effects of reduced epidermal growth factor receptor (EGFR) signaling in Waved-5 mice, which carry a dominant-negative EGFR allele. Despite significantly reduced EGFR signaling, hair follicle morphogenesis appeared normal, although hair cycle induction was slightly delayed. The proliferation and apoptosis of keratinocytes were unaffected. However, there was a notable reduction in subcutaneous adipose tissue thickness and adipocyte proliferation in Waved-5 mice during early postnatal days, suggesting a role for EGFR in regulating subcutaneous fat. These findings indicated that compensatory mechanisms in murine skin maintained normal epidermal and hair follicle function despite low EGFR signaling levels.