Genetic screen identifies microRNA cluster 99b/let-7e/125a as a regulator of primitive hematopoietic cells
Genetic screen identifies microRNA cluster 99b/let-7e/125a as a regulator of primitive hematopoietic cells
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DOI：
10.1182/blood-2011-01-331686
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发表时间：
2012-01-12
期刊：
影响因子：
20.3
通讯作者：
de Haan, Gerald
中科院分区：
文献类型：
--
作者：
Gerrits, Alice;Walasek, Marta A.;de Haan, Gerald
造血干细胞/祖细胞（HSPC）性状在基因不同的小鼠品系之间存在差异。例如，DBA/2小鼠比C57BL/6小鼠具有更高的HSPC频率。我们对从C57BL/6和DBA/2小鼠中分离的LSK、LS-K+、红系和髓系细胞之间差异表达的microrna进行了遗传筛选。该分析鉴定出131种不同细胞类型的微rna和15种不同小鼠品系的微rna。特别令人感兴趣的是位于17号染色体上的一个进化保守的miR簇，由miR-99b、let-7e和miR-125a组成。所有集群成员在lsk中表达最多，并在分化时下调。此外，这些microrna在DBA/2细胞中的表达高于C57BL/6细胞，因此与HSPC频率相关。为了从功能上表征这些microrna，我们在C57BL/6小鼠的BM细胞中过表达整个miR-cluster 99b/let-7e/125a和miR-125a。过表达miR-cluster或miR-125a可显著增加第35天的CAFC活性，并在移植后引起严重的造血表型。我们发现，miR-cluster的单个成员，即miR-125a，是大多数观察到的miR-cluster过表达效应的原因。最后，我们进行了全基因组基因表达阵列，并确定了miR-125a可能通过其调节HSPC命运的候选靶基因。(血。2012;119 (2):377 - 387)
Hematopoietic stem/progenitor cell (HSPC) traits differ between genetically distinct mouse strains. For example, DBA/2 mice have a higher HSPC frequency compared with C57BL/6 mice. We performed a genetic screen for microRNAs that are differentially expressed between LSK, LS-K+, erythroid and myeloid cells isolated from C57BL/6 and DBA/2 mice. This analysis identified 131 micro-RNAs that were differentially expressed between cell types and 15 that were differentially expressed between mouse strains. Of special interest was an evolutionary conserved miR cluster located on chromosome 17 consisting of miR-99b, let-7e, and miR-125a. All cluster members were most highly expressed in LSKs and down-regulated upon differentiation. In addition, these microRNAs were higher expressed in DBA/2 cells compared with C57BL/6 cells, and thus correlated with HSPC frequency. To functionally characterize these microRNAs, we overexpressed the entire miR-cluster 99b/let-7e/125a and miR-125a alone in BM cells from C57BL/6 mice. Overexpression of the miR-cluster or miR-125a dramatically increased day-35 CAFC activity and caused severe hematopoietic phenotypes upon transplantation. We showed that a single member of the miR-cluster, namely miR-125a, is responsible for the majority of the observed miR-cluster overexpression effects. Finally, we performed genome-wide gene expression arrays and identified candidate target genes through which miR-125a may modulate HSPC fate. (Blood. 2012;119(2):377-387)