MicroRNAs regulate distal region of mandibular development through Hh signaling
MicroRNAs regulate distal region of mandibular development through Hh signaling
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DOI：
10.1111/joa.13328
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发表时间：
2020-10
影响因子：
2.4
通讯作者：
Supaluk Trakanant;Jun Nihara;Takahiro Nagai;M. Kawasaki;K. Kawasaki;Y. Ishida;Fumiya Meguro;Takehisa Kudo;A. Yamada;T. Maeda;Isao Saito;A. Ohazama
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作者：
Supaluk Trakanant;Jun Nihara;Takahiro Nagai;M. Kawasaki;K. Kawasaki;Y. Ishida;Fumiya Meguro;Takehisa Kudo;A. Yamada;T. Maeda;Isao Saito;A. Ohazama
下颌畸形常见于各种先天性疾病，表明下颌发育受到严格的分子控制。因此，了解下颌骨发育的分子机制是至关重要的。MicroRNAs （miRNAs）是非编码的小单链rna，在调节基因表达水平中起关键作用。我们发现，由于缺乏Dicer（一种miRNA加工的基本分子，Dicerfl/fl;Wnt1Cre）而引起的间质条件缺失导致发育中的下颌骨远端形成异常凹槽。在E10.5，当该区域形成时，在Dicer突变下颌骨中，Hh信号的抑制剂Ptch1和Hhip1在该区域的表达增加，而Gli1 （Hh信号的主要介质）在突变下颌骨中显著下调。这些表明，在Dicer突变下颌骨的远端，Hh信号通过增加抑制剂被下调。为了了解下颌骨异常沟槽形成指标突变体是否由Hh信号下调引起，我们对由于缺乏Smo （Hh信号激活的必要分子，Smofl/fl;Wnt1Cre）而导致Hh信号活性间质缺失的小鼠进行了研究。Smofl / fl;Wnt1Cre小鼠在下颌骨远端区表现出与Dicerfl/fl小鼠相似的表型；Wnt1Cre老鼠。我们还发现，在E10.5时，野生型下颌间质中表达了大约400个mirna，其中6个mirna被鉴定为具有结合Ptch1和Hhip1的mirna。通过原位杂交证实其在下颌骨远端表达。这表明microRNAs通过控制Hh信号通路抑制剂的表达水平，参与下颌远端形成的早期调控。
Mandibular anomalies are often seen in various congenital diseases, indicating that mandibular development is under strict molecular control. Therefore, it is crucial to understand the molecular mechanisms involved in mandibular development. MicroRNAs (miRNAs) are noncoding small single‐stranded RNAs that play a critical role in regulating the level of gene expression. We found that the mesenchymal conditional deletion of miRNAs arising from a lack of Dicer (an essential molecule for miRNA processing, Dicerfl/fl;Wnt1Cre), led to an abnormal groove formation at the distal end of developing mandibles. At E10.5, when the region forms, inhibitors of Hh signaling, Ptch1 and Hhip1 showed increased expression at the region in Dicer mutant mandibles, while Gli1 (a major mediator of Hh signaling) was significantly downregulated in mutant mandibles. These suggest that Hh signaling was downregulated at the distal end of Dicer mutant mandibles by increased inhibitors. To understand whether the abnormal groove formation inDicer mutant mandibles was caused by the downregulation of Hh signaling, mice with a mesenchymal deletion of Hh signaling activity arising from a lack of Smo (an essential molecule for Hh signaling activation, Smofl/fl;Wnt1Cre) were examined. Smofl/fl;Wnt1Cre mice showed a similar phenotype in the distal region of their mandibles to those in Dicerfl/fl;Wnt1Cre mice. We also found that approximately 400 miRNAs were expressed in wild‐type mandibular mesenchymes at E10.5, and six microRNAs were identified as miRNAs with binding potential against both Ptch1 and Hhip1. Their expressions at the distal end of the mandible were confirmed by in situ hybridization. This indicates that microRNAs regulate the distal part of mandibular formation at an early stage of development by involving Hh signaling activity through controlling its inhibitor expression level.