Characterization of the phosphoinositide 3-kinase-dependent transcriptome in murine embryonic stem cells: identification of novel regulators of pluripotency.
Phosphoinositide 3-kinase (PI3K)-dependent signaling has been implicated in the regulation of embryonic stem (ES) cell fate. To gain further insight into the mechanisms regulated by PI3Ks in murine ES cells, we have performed expression profiling using Affymetrix GeneChips to characterize the transcriptional changes that arise as a result of inhibition of PI3K-dependent signaling. Using filtering of greater than 1.5-fold change in expression and an analysis of variance significance level of p < .05, we have defined a dataset comprising 646 probe sets that detect changes in transcript expression (469 down and 177 up) on inhibition of PI3Ks. Changes in expression of selected genes have been validated by quantitative reverse transcription polymerase chain reaction. Gene ontology analyses reveal significant over-representation of transcriptional regulators within our dataset. In addition, several known regulators of ES cell pluripotency, for example, Nanog, Esrrb, Tbx3, and Tcl-1, are among the downregulated genes. To evaluate the functional involvement of selected genes in regulation of ES cell self-renewal, we have used short interfering RNA-mediated knockdown. These studies identify genes not previously associated with control of ES cell fate that are involved in regulating ES cell pluripotency, including the protein tyrosine phosphatase Shp-1 and the Zscan4 family of zinc finger proteins. Further gain-of-function analyses demonstrate the importance of Zscan4c in regulation of ES cell pluripotency.
Department of Pharmacy and Pharmacology, Centre for Regenerative Medicine, University of Bath, Bath, United Kingdom.
Michael P
MP
Storm
Benjamin
B
Kumpfmueller
Belinda
B
Thompson
Raivo
R
Kolde
Jaak
J
Vilo
Oliver
O
Hummel
Herbert
H
Schulz
Melanie J
MJ
Welham
D000818:Animals; D015153:Blotting, Western; D002478:Cells, Cultured; D053595:Embryonic Stem Cells / Q000502:physiology*; D005434:Flow Cytometry; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D007150:Immunohistochemistry; D051379:Mice; D020411:Oligonucleotide Array Sequence Analysis; D019869:Phosphatidylinositol 3-Kinases / Q000502:physiology*; D039904:Pluripotent Stem Cells / Q000502:physiology*; D053824:Protein Tyrosine Phosphatase, Non-Receptor Type 6 / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000502:physiology*; D014157:Transcription Factors / Q000235:genetics; D016335:Zinc Fingers / Q000235:genetics
D014157:Transcription Factors; D019869:Phosphatidylinositol 3-Kinases; D053824:Protein Tyrosine Phosphatase, Non-Receptor Type 6; C509248:Ptpn6 protein, mouse