Notch signals inhibit the development of erythroid/megakaryocytic cells by suppressing GATA-1 activity through the induction of HES1.
The effects of Notch signals on the erythroid/megakaryocytic differentiation of hematopoietic cells were examined. Activation of Notch signals by the intracellular Notch1 or an estradiol-inducible form of Notch1/ER suppressed the expression of the erythroid marker glycophorin A in an erythroid/megakaryocytic cell line K562. Although Mock-transfected K562 cells underwent megakaryocytic differentiation in response to 12-O-tetradecanoylphorbol-13-acetate (TPA), estradiol-activated Notch1/ER induced apoptosis during TPA treatment in the transfectant, which was accompanied by the reduced expression of an antiapoptotic molecule Bcl-XL. Even when apoptosis was prevented by the overexpression of Bcl-XL, activated Notch signals still inhibited TPA-induced megakaryocytic differentiation. As for this mechanism, Notch1/recombination signal binding protein J-kappa-induced HES1 but not HES5 was found to inhibit the function of an erythroid/megakaryocytic lineage-specific transcription factor GATA-1. Although HES1 did not affect the DNA binding activity of GATA-1 in gel shift and chromatin immunoprecipitation assays, it directly bound to GATA-1 and dissociated a critical transcriptional cofactor, p300, from GATA-1. Furthermore, overexpressed HES1 inhibited the development of erythroid and megakaryocytic cells in colony assays. Also, the Notch ligand Jagged1 expressed on NIH3T3 cells suppressed the development of erythroid and megakaryocytic cells from cocultured Lin-Sca-1+ hematopoietic stem/progenitor cells. These results suggest that Notch1 inhibits the development of erythroid/megakaryocytic cells by suppressing GATA-1 activity through HES1.
Ishiko
Eri
E
Department of Hematology and Oncology, Osaka University Graduate School of Medicine, 2-2, Yamada-oka, Suita, Osaka 565-0871, Japan.
Matsumura
Itaru
I
Ezoe
Sachiko
S
Gale
Karin
K
Ishiko
Jun
J
Satoh
Yusuke
Y
Tanaka
Hirokazu
H
Shibayama
Hirohiko
H
Mizuki
Masao
M
Era
Takumi
T
Enver
Tariq
T
Kanakura
Yuzuru
Y
D000818:Animals; D017209:Apoptosis; D051792:Basic Helix-Loop-Helix Proteins; D015152:Blotting, Northern; D002454:Cell Differentiation; D002460:Cell Line; D019070:Cell Lineage; D002467:Cell Nucleus / Q000378:metabolism; D047369:Chromatin Immunoprecipitation; D018920:Coculture Techniques; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D050881:E1A-Associated p300 Protein; D004912:Erythrocytes / Q000378:metabolism*; D050981:Erythroid-Specific DNA-Binding Factors; D004958:Estradiol / Q000378:metabolism; D005434:Flow Cytometry; D050982:GATA1 Transcription Factor; D006021:Glycophorins / Q000378:metabolism; D006412:Hematopoietic Stem Cells / Q000166:cytology; D018398:Homeodomain Proteins / Q000378:metabolism*; D006801:Humans; D015151:Immunoblotting; D047468:Immunoprecipitation; D020014:K562 Cells; D008156:Luciferases / Q000378:metabolism; D008533:Megakaryocytes / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D008856:Microscopy, Fluorescence; D008957:Models, Genetic; D041681:NIH 3T3 Cells; D009687:Nuclear Proteins / Q000378:metabolism; D010641:Phenotype; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D011960:Receptors, Estrogen / Q000378:metabolism; D051880:Receptors, Notch; D012190:Retroviridae / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013234:Stem Cells / Q000166:cytology; D013755:Tetradecanoylphorbol Acetate / Q000737:chemistry; D015534:Trans-Activators / Q000378:metabolism; D000072056:Transcription Factor HES-1; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic; D014162:Transfection; D051020:bcl-X Protein
D051792:Basic Helix-Loop-Helix Proteins; D004247:DNA; D004268:DNA-Binding Proteins; D050881:E1A-Associated p300 Protein; D050981:Erythroid-Specific DNA-Binding Factors; D004958:Estradiol; D050982:GATA1 Transcription Factor; D006021:Glycophorins; D018398:Homeodomain Proteins; D008156:Luciferases; D008565:Membrane Proteins; D009687:Nuclear Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D011960:Receptors, Estrogen; D051880:Receptors, Notch; D013755:Tetradecanoylphorbol Acetate; D015534:Trans-Activators; D000072056:Transcription Factor HES-1; D014157:Transcription Factors; D051020:bcl-X Protein; C494811:BCL2L1 protein, human; C494812:Bcl2l1 protein, mouse; C494688:GATA1 protein, human; C494689:Gata1 protein, mouse; C078493:HES1 protein, human; C494361:Ep300 protein, mouse