Table 1.

Known advantages and problems associated with the possible therapeutic use of different myogenic cell types

Cell type	Advantages	Major problems	Ref.
Myoblasts	• Pure populations can be isolated and readily expanded and transduced in vitro	• Limited engraftment and migration in host muscle	8, 24, 100
		• High number of cells required for transplantation
		• Immediate immune response after grafting due to high number of cells
		• Poor ability to populate the host satellite cell niche
Satellite cells	• Low numbers required for transplantation	• Limited migration	21, 22, 101, 102
	• Efficient engraftment	• Only small numbers can be isolated
	• Efficient population of the satellite cell niche of the recipient	• Cannot be cultured/maintained ex vivo
Satellite stem cells	• Very efficient engraftment	• No definitive markers available for the enrichment of viable cells	65, 68, 73
	• Few cells required for transplantation
	• Highly efficient population of the satellite cell niche of the recipient	• Not investigated in species other than mouse
	• Extensive migration
Satellite cells on fibers	• Maximal engraftment	• Very difficult to apply in a clinical setting	25, 36, 65
	• Minimal number of cells required
	• Maximal population of the satellite cell niche
Muscle side population cells	• Certain SP cells can home into muscle from the blood stream (systemic delivery possible)	• Contact with myoblasts required for differentiation	90, 103, 104
	• Population of the satellite cell niche of the recipient	• Low engraftment
Mesoangioblasts/pericytes	• Homing from the blood stream into the muscle (systemic delivery possible)	• Undergo senescence after a certain number of population doublings	81, 82, 105–107
	• Can be cultivated ex vivo
	• Readily transducible
		• Sufficient engraftment
	• Engraftment as satellite cells
CD133 positive cells	• Homing from the blood stream into the muscle (systemic delivery possible)	• Engraftment only shown in animal models with severely compromised immune system	85, 86
	• Increased vasculogenesis
	• Engraftment as satellite cells
Myoendothelial cells	• Can be cultured for a long period retaining myogenic potential	• Engraftment only shown in animal models with severely compromised immune system	87
	• Tolerance for oxidative stress
Muscle resident ALDH positive CD34 negative cells	• High proliferative potential upon transplantation	• Engraftment only shown in animal models with severely compromised immune system	88
PW1+ interstitial cells	• Engraftment as satellite cells	• Only shown in a mouse model with severely compromised immune system	89
Bone marrow derived stem cells	• Homing from the blood stream into the muscle (systemic delivery possible)	• Low engraftment	91, 108
Mesenchymal stem cells	• Inhibition of inflammation	• Low engraftment	93, 94
hMAD: human mesenchymal stem cell from adipose tissue	• Easy to access from adipose tissue	• Low engraftment potential without forced expression of MyoD	109, 110
	• Engraftment only shown in animal models with severely compromised immune system
ES cells	• Engraftment as satellite cells	• Risk of teratoma formation	97, 111
		• Pax3/7 overexpression required for reprogramming
iPS cells	• Engraftment as satellite cells	• Risk of teratoma formation	112
	• Autologous transplantations possible	• Reprogramming and purification required
		• Differentiation may be impaired by epigenetic memory of the donor tissue