Rôle du facteur de transcription Gfi1b au cours de l’hématopoïèse précoce
Growth factor independent 1b (GFI1b) is a transcription factor implicated in the regulation of hematopoiesis. It is highly expressed in hematopoietic stem cells (HSCs) and throughout the differentiation of erythroid and megakaryocytic lineages. Using a CreLox system, we have generated mice in which GFI1b is conditionally deleted in megakaryocytic lineages. These mice exhibit a strong proliferation of immature megakaryocytes, which are unable to produce platelets. We were unable to confirm the results of a previously published study from our group, which reported an increase of hematopoietic stem cells in the bone marrow using a different mouse model. However, in agreement with this publication, an increase in the circulating HSC pool can be detected in our GFI1b knockout mice. A preliminary analysis of the molecular role of GFI1b suggests that this transcription factor might be implicated in the circadian regulation of HSC mobilization in the blood. Finally, our experiments on the biological effects of the deletion of GFI1b in the adult murine hematopoietic compartment allowed us to better understand the role of GFI1b in hematopoiesis, and to confirm the major contribution of GFI1b to the development of megakaryocytes and the production of mature platelets.
Gfi1b Hematopoiesis Transcription factor