Mybl2, downregulated during colon epithelial cell maturation, is suppressed by miR-365
Mybl2, downregulated during colon epithelial cell maturation, is suppressed by miR-365
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DOI：
10.1152/ajpgi.00066.2011
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发表时间：
2011-09-01
影响因子：
4.5
通讯作者：
Augenlicht, Leonard H.
中科院分区：
文献类型：
--
作者：
Papetti, Michael;Augenlicht, Leonard H.
基因表达谱的改变反映了肠上皮细胞在其成熟过程中沿着隐窝-管腔轴沿着的重编程。为了关注在这一过程中重要的基因，以及它们又是如何被调控的，我们确定了14种转录本，它们在永生化细胞系Caco-2（吸收性）、HT 29 Cl 16 E（杯状）和HT 29 Cl 19 A（分泌性）的谱系特异性成熟过程中通常表达下调，这些细胞系是由接触抑制生长或短链脂肪酸丁酸酯诱导的。一个这样的基因，Mybl 2（Myb相关蛋白B），已被链接到干细胞表型，我们报告也显着抑制在体内成熟细胞沿着隐窝腔轴。在结肠细胞成熟过程中，Mybl 2在转录上没有显著下调，但我们在Mybl 2 3 '-非翻译区鉴定了一个潜在的微RNA（miRNA）结合序列，该序列介导了分化中的结肠细胞中的报告基因抑制。因此，预测结合该功能靶标的miRNA在体外和体内分化的结肠上皮细胞中上调;其中之一hsa-miR-365（而不是hsa-324- 5 p）的表达抑制增殖的Caco-2细胞中Mybl 2蛋白的表达。这些数据表明，miRNA沉默在调节成熟结肠上皮细胞中的基因表达中起着重要作用，并且利用以靶标为中心的方法，而不是分析全局miRNA表达，可以鉴定生理相关的功能性miRNA。
Altered profiles of gene expression reflect the reprogramming of intestinal epithelial cells during their maturation along the crypt-luminal axis. To focus on genes important in this process, and how they in turn are regulated, we identified 14 transcripts commonly downregulated in expression during lineage-specific maturation of the immortalized cell lines Caco-2 (absorptive), HT29Cl16E (goblet), and HT29Cl19A (secretory) induced by contact inhibition of growth or the short-chain fatty acid butyrate. One such gene, Mybl2 (Myb-related protein B), has been linked to the stem cell phenotype, and we report is also markedly suppressed in maturing cells along the crypt-luminal axis in vivo. Mybl2 is not significantly downregulated transcriptionally during colon cell maturation, but we identified a potential micro-RNA (miRNA)-binding sequence in the Mybl2 3'-untranslated region that mediates reporter gene suppression in differentiating colon cells. Accordingly, miRNAs predicted to bind this functional target are upregulated in differentiating colon epithelial cells in vitro and in vivo; expression of one of these, hsa-miR-365 (but not hsa-324-5p), suppresses Mybl2 protein expression in proliferating Caco-2 cells. These data demonstrate that miRNA silencing plays an important role in regulating gene expression in maturing colon epithelial cells, and that utilizing a target-centered approach, rather than profiling global miRNA expression, can identify physiologically relevant, functional miRNAs.