Hairy tale of signaling in hair follicle development and cycling

Abstract

Hair follicle is an appendage from the vertebrate skin epithelium, and is critical for environmental sensing, animal appearance, and body heat maintenance. Hair follicles arise from the embryonic ectoderm and regenerate cyclically during adult life. Distinct morphological and functional stages from development through homeostasis have been extensively studied for the past decades to dissect the critical molecular mechanisms. Accumulating work suggests that different signaling cascades, such as Wnt, Bmp, Shh, and Notch, together with specific combinations of transcription factors are at work at different stages. Here we provide a comprehensive review of mouse genetics studies, which include lineage tracing along with knockout and over-expression of core genes from key signaling pathways, to paint an updated view of the molecular regulatory network that govern each stage of hair follicle development and adult cycling.

Transcriptome Analysis of Skin from SMP30/GNL Knockout Mice Reveals the Effect of Ascorbic Acid Deficiency on Skin and Hair

“…Shh and Wnt (14) been predicted that the differentiation and formation of hair follicles are prevented by VC deficiency. BMP and Notch signaling pathways are involved in hair growth (15); however, changes in these pathways were not identified in the present study.…”

Foxp1 maintains hair follicle stem cell quiescence through regulation of Fgf18

“…HFs then go through a quiescent phase (telogen) before re-entering the next growth phase. At distinct stages of the hair cycle, HFSCs receive either inhibitory or activating signals from both the micro-and macro-environments to either remain quiescent or become proliferative (Lee and Tumbar, 2012;Sennett and Rendl, 2012).…”

Progress and renewal in gustation: new insights into taste bud development

“…In other renewing epithelia, Hedgehog (Hh) functions as a mitogen or a differentiation factor (Lee and Tumbar, 2012;Takashima and Hartenstein, 2012) or can signal to maintain stem cells (Álvarez-Buylla and Ihrie, 2014;Ferent et al, 2014;Saade et al, 2013). To examine the role of Shh in taste cell renewal, a recent study used inducible genetic models in adult mice to express Shh in K14 + lingual progenitors (Castillo et al, 2014).…”

“…In embryos, Shh represses taste fate (Hall et al, 2003;Iwatsuki et al, 2007), whereas in adults it promotes taste bud differentiation (Castillo et al, 2014). This is not surprising, as the Wnt and Hh pathways have temporally and spatially distinct interactions in many tissues, including hair follicles and neural epithelium (Avilés et al, 2013;Lee and Tumbar, 2012). Interestingly, during embryogenesis BMP signaling promotes taste fate during placode specification and then represses taste fate once taste placodes have formed (Zhou et al, 2006).…”