Adult stem and progenitor cells.
The discovery of adult stem cells in most adult tissues is the basis of a number of clinical studies that are carried out, with therapeutic use of hematopoietic stem cells as a prime example. Intense scientific debate is still ongoing as to whether adult stem cells may have a greater plasticity than previously thought. Although cells with some features of embryonic stem cells that, among others, express Oct4, Nanog and SSEA1 are isolated from fresh tissue, it is not clear if the greater differentiation potential is acquired during cell culture. Moreover, adult more pluripotent cells do not have all pluripotent characteristics typical for embryonic stem cells. Recently, some elegant studies were published in which adult cells could be completely reprogrammed to embryonic stem cell-like cells by overexpression of some key transcription factors for pluripotency (Oct4, Sox2, Klf4 and c-Myc). It will be interesting for the future to investigate the exact mechanisms underlying this reprogramming and whether similar transcription factor pathways are present and/or can be activated in adult more pluripotent stem cells.
Interdepartementaal Stamcelinstituut Leuven (SCIL), Katholieke Universiteit Leuven, Herestraat 49 bus 804, 3000, Leuven, Belgium, Martine.Geraerts@med.kuleuven.be.
Martine
M
Geraerts
Catherine M
CM
Verfaillie
D000328:Adult; D053687:Adult Stem Cells / Q000166:cytology* / Q000378:metabolism; D002454:Cell Differentiation; D002478:Cells, Cultured; D065150:Cellular Reprogramming / Q000235:genetics*; D015870:Gene Expression; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000378:metabolism; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D057026:Induced Pluripotent Stem Cells / Q000166:cytology* / Q000378:metabolism; D000090062:Kruppel-Like Factor 4; D016256:Lewis X Antigen / Q000235:genetics / Q000378:metabolism; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000378:metabolism; D000071317:Nanog Homeobox Protein; D050814:Octamer Transcription Factor-3 / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction
D018398:Homeodomain Proteins; C000715467:KLF4 protein, human; D000090062:Kruppel-Like Factor 4; D016256:Lewis X Antigen; C486780:NANOG protein, human; D000071317:Nanog Homeobox Protein; D050814:Octamer Transcription Factor-3; C494173:POU5F1 protein, human