EKLF restricts megakaryocytic differentiation at the benefit of erythrocytic differentiation.
Previous observations suggested that functional antagonism between FLI-1 and EKLF might be involved in the commitment toward erythrocytic or megakaryocytic differentiation. We show here, using inducible shRNA expression, that EKLF knockdown in mouse erythroleukemia (MEL) cells decreases erythrocytic and increases megakaryocytic as well as Fli-1 gene expression. Chromatin immunoprecipitation analyses revealed that the increase in megakaryocytic gene expression is associated with a marked increase in RNA pol II and FLI-1 occupancy at their promoters, albeit FLI-1 protein levels are only minimally affected. Similarly, we show that human CD34(+) progenitors infected with shRNA lentivirus allowing EKLF knockdown generate an increased number of differentiated megakaryocytic cells associated with increased levels of megakaryocytic and Fli-1 gene transcripts. Single-cell progeny analysis of a cell population enriched in bipotent progenitors revealed that EKLF knockdown increases the number of megakaryocytic at the expense of erythrocytic colonies. Taken together, these data indicate that EKLF restricts megakaryocytic differentiation to the benefit of erythrocytic differentiation and suggest that this might be at least partially mediated by the inhibition of FLI-1 recruitment to megakaryocytic and Fli-1 gene promoters.
Université de Lyon, Lyon, France.
Fabrice
F
Bouilloux
Gaëtan
G
Juban
Nathalie
N
Cohet
Dorothée
D
Buet
Boris
B
Guyot
William
W
Vainchenker
Fawzia
F
Louache
François
F
Morlé
D000818:Animals; D002454:Cell Differentiation; D002460:Cell Line; D004912:Erythrocytes / Q000166:cytology*; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000187:drug effects; D006801:Humans; D051741:Kruppel-Like Transcription Factors / Q000235:genetics / Q000502:physiology*; D008533:Megakaryocytes / Q000166:cytology*; D051379:Mice; D051789:Proto-Oncogene Protein c-fli-1 / Q000037:antagonists & inhibitors / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis; D034741:RNA, Small Interfering / Q000494:pharmacology
D051741:Kruppel-Like Transcription Factors; D051789:Proto-Oncogene Protein c-fli-1; D012333:RNA, Messenger; D034741:RNA, Small Interfering; C080774:erythroid Kruppel-like factor