Table 1.
Skin-specific stem cells and putative features of their niche.
| In situ location | Epidermal stem cell | Dermal stem cell | Adipose stem cell |
|---|---|---|---|
| Hair follicle bulge | Dermal papilla | Perivascular/vascular | |
| Signaling pathways | Wnt | Wnt | VEGF |
| β-catenin | Timp | PPARγ | |
| Shh | BMPs | FGF2 | |
| TGFβ | FGF | MMPs | |
| BMPs | Shh | PDGF | |
| p63 | IGF | ||
| Notch | |||
|
| |||
| Surface and structural proteins | K5 | NG2 | CD29 |
| K14 | CD34 | CD44 | |
| K15 | CD44 | CD73 | |
| E-cadherin | CD54 | CD90 | |
| LGR5 | CD73 | CD105 | |
| LGR6 | CD90 | CD166 | |
| CD29 | CD105 | PDGFRβ | |
| CD34 | CD133 | Integrin α6β1 | |
| CD49f | CD271 | ||
| CD117 | |||
| CD200 | |||
|
| |||
| Potential matrix components | Laminin | Fibrin | |
| Collagen IV | Collagen I | ||
| Collagen XVII | |||
| Nephronectin | |||
Wnt: wingless-type; Shh: sonic hedgehog; BMP: bone morphogenetic protein; TGFβ: transforming growth factor β, VEGF: vascular endothelial growth factor; FGF: fibroblast growth factor; IGF: insulin-like growth factor; PDGF: platelet-derived growth factor; PPARγ: peroxisome proliferator-activated receptor γ; MMP: matrix metalloproteinase; Timp: tissue inhibitor of metalloproteinases.