Design principle of gene expression used by human stem cells: implication for pluripotency.
Human embryonic stem cells (ESC) are undifferentiated and are endowed with the capacities of self-renewal and pluripotential differentiation. Adult stem cells renew their own tissue, but whether they can transdifferentiate to other tissues is still controversial. To understand the genetic program that underlies the pluripotency of stem cells, we compared the transcription profile of ESC with that of progenitor/stem cells of human hematopoietic and keratinocytic origins, along with their mature cells to be viewed as snapshots along tissue differentiation. ESC gene profiles show higher complexity with significantly more highly expressed genes than adult cells. We hypothesize that ESC use a strategy of expressing genes that represent various differentiation pathways and selection of only a few for continuous expression upon differentiation to a particular target. Such a strategy may be necessary for the pluripotency of ESC. The progenitors of either hematopoietic or keratinocytic cells also follow the same design principle. Using advanced clustering, we show that many of the ESC expressed genes are turned off in the progenitors/stem cells followed by a further down-regulation in adult tissues. Concomitantly, genes specific to the target tissue are up-regulated toward mature cells of skin or blood.
Golan-Mashiach
Michal
M
Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel.
Dazard
Jean-Eudes
JE
Gerecht-Nir
Sharon
S
Amariglio
Ninette
N
Fisher
Tamar
T
Jacob-Hirsch
Jasmine
J
Bielorai
Bella
B
Osenberg
Sivan
S
Barad
Omer
O
Getz
Gad
G
Toren
Amos
A
Rechavi
Gideon
G
Itskovitz-Eldor
Joseph
J
Domany
Eytan
E
Givol
David
D
D002454:Cell Differentiation / Q000235:genetics; D002460:Cell Line; D019070:Cell Lineage / Q000235:genetics; D016000:Cluster Analysis; D019295:Computational Biology / Q000379:methods; D015536:Down-Regulation / Q000235:genetics; D004622:Embryo, Mammalian / Q000166:cytology; D020869:Gene Expression Profiling / Q000379:methods / Q000706:statistics & numerical data; D005786:Gene Expression Regulation / Q000235:genetics; D018507:Gene Expression Regulation, Developmental / Q000235:genetics*; D005819:Genetic Markers / Q000235:genetics; D006412:Hematopoietic Stem Cells / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D015603:Keratinocytes / Q000737:chemistry / Q000378:metabolism / Q000502:physiology; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods; D009928:Organ Specificity / Q000235:genetics; D039904:Pluripotent Stem Cells / Q000737:chemistry / Q000378:metabolism; D012107:Research Design / Q000592:standards*; D013234:Stem Cells / Q000737:chemistry* / Q000378:metabolism*
D005819:Genetic Markers