Cellular Players in Skeletal Muscle Regeneration

Table 1

Phenotypic synopsis of the cells found in skeletal muscle interstitium.

Cell types				Markers	Negative markers	Reference	Secreted molecules	Reference
Stem cells	Resident	Satellite cells^*#		Pax7, Pax3, Myf5, Barx2, M-cadherin, CD206, CCL2/CCR2, CTRs, CXCR4, c-Met, CD34, p75NTR, Tie-2, α7-intergin, β1-integrin, VECAM-1, syndecan-3 and syndecan-4, NCAM/CD56, caveolin-1, Nestin, SM/C-2.6, PW1, HMGB1	CD45, Sca-1, desmin, MyHC	[15, 20–41]
		Nonspecified location	Muscle-derived side population cells (MSP cells)*	Abcg2, Sca-1, CD11, Gr-1, CD5	c-kit, CD43, CD45, CD34.	[8, 42, 43]
			PICs#	PW1, Sca-1, CD34, vimentin	PDGFRα	[43, 44]
			Slow-adhering stem cells (SASCs)*	Notch1, STAT3, Msx1, Pax3, MMP2		[45]
			Sk-34 myoendothelial progenitors#	CD34, Sca-1, c-Met	CD45, CD14, CD31, CD49, CD144 Flk1, MyoD, myf-5, myf-6, myogenin, M-cadherin, Pax-3, Pax-7.	[46]
		Vessel-associated	Mesoangioblasts (vessel-associated stem cells)*	E-selectin, β7, integrin, AlCAM, CD44, cav1, FGFR1, CXCR-4, TNF-R, TNFR 1a, IL-10R, IL-4R, RAGE, TLR4 (HMGB1 rec), CD13	CD34, CD45, CD117 CD31	[47–49]	HMGB1, VEGF, CXCL12/SDF1, CCL2, VEGF B, bFGF, FGF7, PDGF AA, HDGF	[49, 50]
			Myogenic endothelial cells (MECs)#	CD56, CD34, Pax7, von Willebrand factor, VE-cadherin/CD144, UEA-1 receptor	CD45	[51, 52]
			Pericytes^*#	CCR2, Abcg2, Alkaline phosphatase, αSMA, desmin, NG2, aminopeptidase A/B, RGS5, CD146, PDGFRα and β, NG2	vWF, CD31, CD34, CD144, CD45, CD56, Pax7	[52–60]	Ang 1	[29]
			Adventitial cells (ACs)#	CD34, Sca-1, Flk1, CD140b	c-kit, CD31, CD146, CD45	[61, 62]
	Blood-derived		AC133+ cells	CD133, CD34, CD90, CD45		[63]
			Bone marrow-derived SP cells	c-kit, CD43, CD45, Sca-1	B220, Mac-1, Gr-1, CD4, CD5, CD8, CD34	[42]
Interstitial cells	Vascular cells		Endothelial cells	von Willebrand factor, CD146, CD31, CD34, CD144, CD105, Abcg2, Tie-2	CCR2	[52, 54, 56, 64–66]	MCP-1, TNFα, VEGF, IGF-1, FGF-2, PDGF-BB, HGF, IL-6, IL-8, TNFα	[29, 33, 67–69]
			Smooth muscle cells	SMA, CCR2, α-actin, caldesmon, calponin		[59, 70, 71]	Ang 1	[29]
	Nerve cells		Schwann cells	NCAM/CD56, nestin; S-100, GFAP, Krox24	cytokeratin	[72–77]	CTNF, IGF-1, NGF	[78]
			Perineurial cells	Epithelial membrane antigen (EMA); GLUT-1, claudin-1, ZO-1, connexins, occludin, vinculin, talin, desmin, titin, spectrin, CD34, VE-cadherin, AQP-1, tenascin-C	cytokeratin; S-100, CD57, neurofilaments	[74, 79, 80]
					Neurons (axon)	Nf200, βIII tubulin		[76]	Neuregulin, calcitonin gene related peptide (CGRP)	[76]
	Resident cells in muscle connective tissue sheaths		Fibroblasts	CCR2, vimentin, procollagen, ET-TR, FSP-1, SMA		[60, 81–85]	PDGF AA, MCP-1, TNFα, Ang-1	[29, 50, 67, 69]
			Tcf4+ fibroblasts#	Tcf4, PDGFRα	Pax7, MyoD, F4/80	[86, 87]
			SDF-1+ muscle-derived fibroblasts*				SDF-1	[24]
			MPs
			FAPs^*#	Sca-1, PDGFRα, CD34	CD45, CD31, α7 integrin	[10, 56, 83, 88]	IL6	[83]
			PDGFRα+^*#	PDGFRα, vimentin	NG2, SMA, Pax7, M-cadherin	[10]
			Tie2+ skeletogenic  progenitors^*#	Tie2, Sca-1, PDFGRα, CD29, CD34	CD31, CD45, CD11b, CXCR4, c-kit, NG2	[89]
			Telocytes (TCs)^*#	c-kit, CD34, vimentin, PDGFRα/β		[90, 91]	VEGF	[91]
	Blood-derived connective tissue cells		Macrophages M1	CD68, CD86, CD40, CD14, MHC I/II, CCR2		[49, 71]	TNFα, IL1β, TNFα, IL-6, TNF-α, IL- 1β, IL-12, IFN-γ, NO, VEGF, HMGB1, CCL2, MCP-1	[49, 67]
			Macrophages M2	CD163, CD36, CD163, CD206, MHC I/II, CD14, αV-integrin, αVβ3I, VCAM-1, membrane-bound CX3CL1, ICAM-1 PECAM-1		[49, 92]	IGF1, IL10, MMP-9, IL10 and Low: IL-6, TNF-α, IL- 1β, IFN-γ	[49]
			Mast cells	c-kit, mast cell triptase		[93, 94]	TNFα, histamine, chymase, tryptase, IL-1, IL-6	[67, 93, 95]
			Polimorphonuclear	CXCR2, CD11b, CD45		[96]	MPO	[97]
		Myoblasts			Myogenin, Pax3 (cycling myoblasts), α-actin, myosin heavy chain, CCR1 and CCR5, CCR2. gp130 and LIFR, NCAM/CD56, VLA-4, CX3CR1, LFA-1 and PECAM-1, Sca-1, Tie-2, p75NTR, desmin, Myf5, HMGB1, TLR4, nestin	Pax7, CCR2	[28, 29, 34, 39, 73, 78, 88, 92, 98–103]	TNFα, INFγ, VEGF, Ang-1; G-CSF/G-CSFR	[104, 105]
	Myocytes/Myotubes			Myogenin, MRF4, CNTFR, NCAM/CD56, nestin, RAGE		[34, 73, 78, 102, 103]	TNFα	[104]

∗In vitro, #in situ.