BACKGROUND: Adult stem cells come from many sources and have the capacity to 
differentiate into many cell types, including those of the skin. The most 
commonly studied stem cells are those termed mesenchymal stem cells (MSCs), 
which are easily isolated from bone marrow and adipose tissue. Mesenchymal stem 
cells are known to produce a wide array of cytokines that modulate the 
regeneration process. The ease of collection, propagation and use of these MSCs 
in therapy of traumatic, ischaemic and immune-mediated skin conditions is 
emerging.
APPROACH AND EVIDENCE: In traumatic and ischaemic skin damage, MSCs are used in 
tissue-engineered skin and by direct injection into damaged tissue. For 
immune-mediated diseases, systemic administration of stem cells can modulate the 
immune system. The earliest clinical work has been with autologous stem cell 
sources, such as adipose tissue and bone marrow. In immune-mediated diseases, 
the MSCs are used to downregulate production of inflammatory cytokines and to 
block T-cell activation. Cells are generally given intravenously. Multiple 
sclerosis, rheumatoid arthritis and lupus have been successfully treated in 
human clinical trials. Mesenchymal stem cells can also stimulate resident local 
cells, such as keratinocytes and progenitor cells, to proliferate, migrate and 
repair skin injury and disease.
LOOKING AHEAD: The discovery of the MSC in adipose tissue has spawned a global 
effort to utilize these cells in therapy of a wide range of diseases of the 
skin. Reconstructive surgery, scar blocking and resolution and skin regeneration 
have all been shown to be possible in human and animal studies.