Control of vertebrate multiciliogenesis by miR-449 through direct repression of the Delta/Notch pathway
Control of vertebrate multiciliogenesis by miR-449 through direct repression of the Delta/Notch pathway
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DOI：
10.1038/ncb2241
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发表时间：
2011-06-01
影响因子：
21.3
通讯作者：
Barbry, Pascal
中科院分区：
文献类型：
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作者：
Marcet, Brice;Chevalier, Benoit;Barbry, Pascal
一些脊椎动物上皮表面的多纤毛细胞对于各种生理过程（例如气道清洁）至关重要(1-3)。然而，控制运动纤毛生物合成的机制仍不清楚。我们将 miR-449 microRNA 确定为脊椎动物多纤毛发生的进化保守的关键调节因子。在人气道上皮和非洲爪蟾胚胎表皮中，miR-449 microRNA 在多纤毛细胞中大量积累。在这两个模型中，我们表明 miR-449 microRNA 通过直接抑制 Delta/Notch 通路来促进中心粒增殖和多纤毛发生。我们将 Notch1 及其配体 Delta-like 1 (DLL1) 确定为 miR-449 的真正靶标。多纤毛细胞中的人 DLL1 和 NOTCH1 蛋白水平低于周围细胞，在 miR-449 过表达后降低，在 miR-449 抑制后升高。在青蛙中，miR-449 沉默导致 Dill 表达增加。一致地，缺乏 miR-449 靶位点的 Dill mRNA 过表达会抑制多纤毛发生，而 Dill 和 Notch1 敲低都可以挽救 miR-449 缺陷细胞中的多纤毛发生。内源性人Notch1或青蛙莳萝的miR-449结合位点的反义介导保护强烈抑制多纤毛发生。我们的结果揭示了一种保守机制，即 Notch 信号传导必须经历 miR-449 介导的抑制才能允许纤毛细胞祖细胞分化。
Multiciliated cells lining the surface of some vertebrate epithelia are essential for various physiological processes, such as airway cleansing(1-3). However, the mechanisms governing motile cilia biosynthesis remain poorly elucidated. We identify miR-449 microRNAs as evolutionarily conserved key regulators of vertebrate multiciliogenesis. In human airway epithelium and Xenopus laevis embryonic epidermis, miR-449 microRNAs strongly accumulated in multiciliated cells. In both models, we show that miR-449 microRNAs promote centriole multiplication and multiciliogenesis by directly repressing the Delta/Notch pathway. We established Notch1 and its ligand Delta-like 1 (DLL1) as miR-449 bona fide targets. Human DLL1 and NOTCH1 protein levels were lower in multiciliated cells than in surrounding cells, decreased after miR-449 overexpression and increased after miR-449 inhibition. In frog, miR-449 silencing led to increased Dill expression. Consistently, overexpression of Dill mRNA lacking miR-449 target sites repressed multiciliogenesis, whereas both Dill and Notch1 knockdown rescued multiciliogenesis in miR-449-deficient cells. Antisense-mediated protection of miR-449-binding sites of endogenous human Notch1 or frog Dill strongly repressed multiciliogenesis. Our results unravel a conserved mechanism whereby Notch signalling must undergo miR-449-mediated inhibition to permit differentiation of ciliated cell progenitors.