HGM 2010 Programme / Abstract

Hematopoiesis entails a series of hierarchically organized events that proceed throughout cell specification and terminates with cell differentiation. Commitment needs the transcription factors effort that, in concert with microRNAs, drives cell fate and responds to promiscuous patterns of gene expression by turning-on lineage-specific genes and repressing alternate lineage transcripts. We obtained microRNAs profiles from human CD34+ hematopoietic progenitor cells and in-vitro differentiated erythroblasts, megakaryoblasts, monoblasts and myeloblasts precursors, that we analyzed together with their gene expression profiles. The integrated analysis of microRNA-mRNA expression levels highlighted an inverse correlation between microRNAs specifically up-regulated in one single cell progeny and their putative target genes, which resulted down-regulated. Among the up-regulated lineage-enriched microRNAs, hsa-miR-299-5p emerged as having a role in controlling CD34+ progenitors fate, grown in multilineage culture conditions. Gain- and loss-of-function experiments revealed that hsa-miR-299-5p participates the regulation of hematopoietic progenitors fate, modulating megakaryocytic-granulocytic versus erythroid-monocytic differentiation.