IWASAKI Masayuki    Department   Research Institutes and Facilities, Research Institutes and Facilities    Position   Assistant Professor
Article types	Original article
Language	English
Peer review	Peer reviewed
Title	MicroRNA-127-3p controls murine hematopoietic stem cell maintenance by limiting differentiation.
Journal	Formal name：Haematologica Abbreviation：Haematologica ISSN code：15928721/03906078
Domestic / Foregin	Foregin
Volume, Issue, Page	104(9),pp.1744-1755
Author and coauthor	Crisafulli Laura, Muggeo Sharon, Uva Paolo, Wang Yulei, Iwasaki Masayuki, Locatelli Silvia, Anselmo Achille, Colombo Federico S, Carlo-Stella Carmelo, Cleary Michael L, Villa Anna, Gentner Bernhard, Ficara Francesca
Publication date	2019
Summary	The balance between self-renewal and differentiation is crucial to ensure the homeostasis of the hematopoietic system, and is a hallmark of hematopoietic stem cells. However, the underlying molecular pathways, including the role of micro-RNA, are not completely understood. To assess the contribution of micro-RNA, we performed micro-RNA profiling of hematopoietic stem cells and their immediate downstream progeny multi-potent progenitors from wild-type control and Pbx1-conditional knockout mice, whose stem cells display a profound self-renewal defect. Unsupervised hierarchical cluster analysis separated stem cells from multi-potent progenitors, suggesting that micro-RNA might regulate the first transition step in the adult hematopoietic development. Notably, Pbx1-deficient and wild-type cells clustered separately, linking micro-RNAs to self-renewal impairment. Differential expression analysis of micro-RNA in the physiological stem cell-to-multi-potent progenitor transition and in Pbx1-deficient stem cells compared to control stem cells revealed miR-127-3p as the most differentially expressed. Furthermore, miR-127-3p was strongly stem cell-specific, being quickly down-regulated upon differentiation and not re-expressed further downstream in the bone marrow hematopoietic hierarchy. Inhibition of miR-127-3p function in Lineage-negative cells, achieved through a lentiviral-sponge vector, led to severe stem cell depletion, as assessed with serial transplantation assays. miR-127-3p-sponged stem cells displayed accelerated differentiation, which was uncoupled from proliferation, accounting for the observed stem cell reduction. miR-127-3p overexpression in Lineage-negative cells did not alter stem cell pool size, but gave rise to lymphopenia, likely due to lack of miR-127-3p physiological downregulation beyond the stem cell stage. Thus, tight regulation of miR-127-3p is crucial to preserve the self-renewing stem cell pool and homeostasis of the hematopoietic system.
DOI	10.3324/haematol.2018.198499
PMID	30792210