MicroRNA-23b Cluster MicroRNAs Regulate Transforming Growth Factor-Beta/Bone Morphogenetic Protein Signaling and Liver Stem Cell Differentiation by Targeting Smads
MicroRNA-23b Cluster MicroRNAs Regulate Transforming Growth Factor-Beta/Bone Morphogenetic Protein Signaling and Liver Stem Cell Differentiation by Targeting Smads
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DOI：
10.1002/hep.22982
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发表时间：
2009-08-01
期刊：
影响因子：
13.5
通讯作者：
Rogler, Leslie E.
中科院分区：
文献类型：
--
作者：
Rogler, Charles E.;LeVoci, Lauretta;Rogler, Leslie E.
转化生长因子- β /骨形态发生蛋白（TGF - β /BMP）信号在胎鼠肝脏细胞命运选择中具有梯度效应。在TGF β配体和受体普遍存在的情况下，邻近细胞发育成胆管或积极生长为肝细胞的分子机制尚不清楚。我们假设microRNAs （miRNAs）可能在肝脏细胞命运决定中发挥作用。小鼠胎儿发育后期的miRNA分析发现，miR-23b集群miRNA包括miR-23b、miR-27b、miR-24-1和miR-10a、miR-26a和miR-30a上调。妊娠17.5天的胎肝原位杂交显示miR-23b簇仅在胎肝细胞中表达。采用互补(c)DNA微阵列方法鉴定与miR-23b簇mirna相互表达模式的基因。该方法确定Smads（母亲抗十足瘫痪同源物），关键TGF β信号分子，作为假定的miR-23b簇靶点。生物信息学分析在Smads 3、4和5的3' utr（非翻译区）中发现了多个候选靶点。双荧光素酶报告基因测定证实，miR-23b粉尘模拟物的混合物可下调含有Smad 3,4或5,3 ' utr的构建体。胎儿肝干细胞系HBC-3肝细胞分化过程中miR-23b mirna的敲低在这些细胞中，除了Smads外，还促进了胆管基因的表达。相反，在HBC-3细胞的胆管分化过程中，miR-23b模拟物的异位表达阻断了这一过程。结论：我们的数据提供了一个模型，miR-23b miRNAs通过下调Smads和TGF - β信号通路抑制胎儿肝细胞胆管基因表达，同时促进胎儿肝细胞生长。同时，胆管细胞中需要低水平的miR-23b mirna来允许TGF β信号传导和胆管形成。(肝脏病学50:575 2009;584)。
Transforming growth factor-beta / bone morphogenetic protein (TGF beta/BMP) signaling has a gradient of effects on cell fate choice in the fetal mouse liver. The molecular mechanism to understand why adjacent cells develop into bile ducts or grow actively as hepatocytes in the ubiquitous presence of both TGF beta ligands and receptors has been unknown. We hypothesized that microRNAs (miRNAs) might play a role in cell fate decisions in the liver. miRNA profiling during late fetal development in the mouse identified miR-23b cluster miRNAs comprising miR-23b, miR-27b, and miR-24-1 and miR-10a, miR-26a, and miR-30a as up-regulated. In situ hybridization of fetal liver at embryonic day 17.5 of gestation revealed miR-23b cluster expression only in fetal hepatocytes. A complementary (c)DNA microarray approach was used to identify genes with a reciprocal expression pattern to that of miR-23b cluster miRNAs. This approach identified Smads (mothers against decapentaplegic homolog), the key TGF beta signaling molecules, as putative miR-23b cluster targets. Bioinformatic analysis identified multiple candidate target sites in the 3' UTRs (untranslated regions) of Smads 3, 4, and 5. Dual luciferase reporter assays confirmed down-regulation of constructs containing Smad 3, 4, or 5, 3' UTRs by a mixture of miR-23b duster mimics. Knockdown of miR-23b miRNAs during hepatocytic differentiation of a fetal liver stem cell line, HBC-3. promoted expression of bile duct genes, in addition to Smads, in these cells. In contrast, ectopic expression of miR-23b mimics during bile duct differentiation of HBC-3 cells blocked the process. Conclusion: Our data provide a model in which miR-23b miRNAs repress bile duct gene expression in fetal hepatocytes while promoting their growth by down-regulating Smads and consequently TGF beta signaling. Concomitantly, low levels of the miR-23b miRNAs are needed in cholangiocytes to allow TGF beta signaling and bile duct formation. (HEPATOLOGY 2009;50:575-584.)