miRNA expression in granulopoiesis

Normal human neutrophil development is a complex biological process, where the balance between cell proliferation, differentiation and apoptosis is tightly regulated by a transcriptional program that results in the production of appropriate numbers of circulating mature neutrophils. MicroRNAs (miRNAs) are small non-coding RNAs of 18~25 nt that affect cellular protein levels. Only limited data is available on miRNA expression patterns during normal granulocytic differentiation of primary human cells. We have examined miRNA expression patterns in distinct stages of granulocytic differentiation sorted from human bone marrow and identified highly stage-specific expressed miRNAs. Some of these differentially expressed miRNA are related to each other in terms of seed sequence (miRNA families) and location on the genome (miRNA clusters). These data reveal distinct expression patterns of specific miRNA sets that closely follow the transition of discrete maturation stages along the myeloblast-neutrophil pathway. In total 13 samples were measured, 2 myeloblast, 3 myeloblast/promyelocyte, 4 metamyelocytes and 3 neutrophils