A 'Hot' New Twist to Hair Biology: Involvement of Vanilloid Receptor-1 Signaling in Human Hair Growth Control
September 2004
in “
Experimental Dermatology
”
vanilloid receptor-1 VR1 capsaicin TGFβ2 IL‐1β HGF IGF‐1 SCF anagen phase catagen phase outer root sheath keratinocytes HaCaT keratinocytes apoptosis intracellular calcium vanilloid receptor transforming growth factor beta 2 interleukin 1 beta hepatocyte growth factor insulin-like growth factor 1 stem cell factor
TLDR VR1 signaling can inhibit hair growth by affecting cell processes and increasing hair growth inhibitors.
The study investigated the role of the vanilloid receptor-1 (VR1) in human hair follicles, focusing on its impact on hair growth. VR1 was found in specific epithelial compartments of hair follicles during anagen and catagen phases, but not in dermal papilla fibroblasts or hair follicle melanocytes. Activation of VR1 by capsaicin in organ culture led to a dose-dependent inhibition of hair shaft elongation, reduced cell proliferation, increased apoptosis, and induced catagen transformation, likely due to the upregulation of the hair growth inhibitor TGFβ2. Additionally, VR1 stimulation in cultured outer root sheath keratinocytes increased the expression of hair growth inhibitors (IL-1β and TGFβ2) and decreased the expression of growth stimulators (HGF, IGF-1, and SCF), without affecting key differentiation markers. The findings suggested that VR1 played a significant role in human hair growth control, extending its functions beyond sensory neuron-related nociception.
