A Two-Step Mechanism for Stem Cell Activation during Hair Regeneration

By V. Greco, Ting-mei Chen, Michael Rendl, M. Schober, H. Pasolli, N. Stokes, June dela Cruz-Racelis, Elaine Fuchs. Cell Stem Cell, 2009

785 citations recorded by the source corpus.

SUMMARY Hair follicles (HFs) undergo cyclic bouts of degeneration, rest, and regeneration. During rest (telogen), the hair germ (HG) appears as a small cell cluster between the slow-cycling bulge and dermal papilla (DP). Here we show that HG cells are derived from bulge stem cells (SCs) but become responsive quicker to DP-promoting signals. In vitro, HG cells also proliferate sooner but display shorter-lived potential than bulge cells. Molecularly, they more closely resemble activated bulge rather than transit-amplifying (matrix) cells. Transcriptional profiling reveals precocious activity of both HG and DP in late telogen, accompanied by Wnt signaling in HG and elevated FGFs and BMP inhibitors in DP. FGFs and BMP inhibitors participate with Wnts in exerting selective and potent stimuli to the HG both in vivo and in vitro. Our findings suggest a model where HG cells fuel initial steps in hair regeneration, while the bulge is the engine maintaining the process.

Subfields: Cell Biology, Molecular Biology, Urology

View Paper: https://www.semanticscholar.org/paper/6e9c8cc53e0aacd2000638b1ff5be0dbccc7eb7f

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Cell Biology

1. V. Horsley
2. H. Pasolli
3. Elaine Fuchs
4. C. Blanpain
5. Pengfei Lu

In Molecular Biology

1. V. Horsley
2. H. Pasolli
3. Y. Hsu
4. Elaine Fuchs
5. G. Gurtner
6. Melanie Rodrigues
7. Nina Kosaric
8. S. Angers

In Urology

1. V. Horsley
2. H. Pasolli
3. Y. Hsu
4. Elaine Fuchs
5. C. Blanpain

Citations in the corpus

• Adipocyte lineage cells contribute to the skin stem cell niche to drive hair cycling (2011, background): “Following hair follicle morphogenesis (growth phase, anagen), the active portion of the follicle regresses (death phase, catagen), leaving the bulge region with a small hair germ that remains dormant during the resting phase (telogen) (Greco et al., 2009).”
• Wound healing and skin regeneration. (2015, background): “Once the hair follicle forms, hair is produced cyclically by interactions between epithelial stem cells in the hair follicle bulge/secondary hair germ area and dermal papilla cells throughout life (Cotsarelis et al. 1990; Kishimoto et al. 2000; Botchkarev et al. 2001; Ito et al. 2002, 2004; Rendl et”
• Wound Healing: A Cellular Perspective. (2019, background): “Cells within the secondary hair germ maintain similar markers as the lower bulge stem cells but undergo more divisions in anaphase than the bulge cells due to their proximity to signals from the dermal papilla (156).”
• Wnt signaling in development and tissue homeostasis (2018, background): “Specifically, Wnt-β-catenin signaling acts on multiple cell types to induce the telogen-anagen transition (Greco et al., 2009; Kishimoto et al., 2000; Van Mater et al., 2003).”
• Dynamics Between Stem Cells, Niche and Progeny in the Hair Follicle (2011, positive): “Our findings agree with prior studies emphasizing close proximity to DP stimuli in explaining why HG is activated so quickly at the start of a new cycle (Greco et al., 2009).”