Stem Cell Niches for Skin Regeneration

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.