The Role of IRF6 During Craniofacial Development

描述（由申请人提供）：孤立性唇腭裂是一种常见的先天性问题，病因复杂。本研究的目的是确定腭形成的关键基因的功能。干扰素调节因子6（IRF 6）的遗传变异导致货车德沃德综合征（VWS），并导致12%的孤立性唇腭裂风险。含有Irf 6的途径及其在协调腭发育中的细胞作用尚不清楚。缺乏Irf 6的小鼠具有腭裂、小颌畸形和口腔粘连。缺乏FgflO或Tbx 1的小鼠具有腭裂和口腔粘连。人类中Tbx，1、Fgf 10和Fgf 8的突变导致唇腭裂。来自我们实验室的初步数据表明，腭间充质中的Fgf 10表达和腭上皮中的Fgf 8表达可能是Irf 6激活的下游靶标。此外，Irf 6在颅面区域可以调节Tbx 1在腭中的表达。因此，我们假设Irf 6的功能在细胞自主的方式来调节上皮分化和在非细胞自主的方式影响间充质分化，这些功能部分介导的FGF信号转导途径和Tbx 1。我们建议建立IRF 6在腭发育和上皮间质信号传导中的作用。我们将评估细胞凋亡和增殖的IrfSA-腭架在体内和使用体外腭培养。嵌合小鼠将用于确定Irf 6是否以细胞自主方式发出信号。为了确定Irf 6在腭间充质发育中的作用，我们将使用神经嵴和非神经嵴特异性的小鼠系。在目标2中，我们将确定FgflO是否是腭生长期间Irf 6信号传导的下游靶标。我们将评估Irf 6和FgflO缺失小鼠中Irf 6和FgflO表达的变化，并通过创建双Fgf 10/lrf 6杂合小鼠来测试是否存在直接的遗传相互作用。在目标3中，我们将鉴定负责从上皮到间充质的Irf 6信号传导的基因。我们将研究在lrf 6 - 1-小鼠中Tbx 1和Fgf 8表达的变化。为了测试是否存在直接的遗传相互作用，我们将创建双杂合Irf 6/Tbx 1和Irf 6/Fgf 8小鼠。这项研究的目的是了解包括IRF 6在内的信号通路，以及该通路的缺陷如何导致唇腭裂。我们将利用这些信息来研究人类唇腭裂患者中潜在的基因-基因相互作用。

DESCRIPTION (provided by applicant): Isolated cleft lip and palate is a common congenital problem with a complex etiology. The objective of this research is to identify the function of genes critical to palatal formation. Genetic variation in Interferon Regulatory Factor 6 (IRF6) causes Van der Woude syndrome (VWS) and contributes 12% risk of isolated cleft lip and palate. The pathway containing Irf6 and its cellular role in orchestrating palatal development is not known. Mice deficient for Irf6 have cleft palate, micrognathia and oral adhesions. Mice deficient for either FgflO or Tbx1 have cleft palate and oral adhesions. Mutations in Tbx,1, FgflO, and Fgf8 in humans cause cleft lip and palate. Preliminary data from our laboratory suggests that FgflO expression in the palatal mesenchyme and Fgf8 expression in the palatal epithelium may be downstream targets for Irf6 activation. Furthermore, Irf6 in the craniofacial region may modulate expression of Tbx1 in the palate. Thus, we hypothesize that Irf6 functions in both a cell-autonomous manner to regulate epithelial differentiation and in a non-cell autonomous manner affecting mesenchymal differentiation and these functions are mediated in part through the Fgf signal transduction pathway and Tbx1. We propose to establish the role of Irf6 in palatogenesis and epithelial-mesenchymal signaling. We will evaluate apoptosis and proliferation in IrfSA- palatal shelves in-vivo and using in-vitro palatal cultures. Chimeric mice will be used to determine if Irf6 signals in a cell-autonomous fashion. To identify the role of Irf6 in palatal mesenchyme development we will use neural crest and non-neural crest specific ere mouse lines. In Aim 2 we will determine if FgflO is a downstream target of Irf6 signaling during palatal growth. We will evaluate changes in Irf6 and FgflO expression in Irf6 and FgflO null mice and test if there is a direct genetic interaction by creating double Fgf10/lrf6 heterozygous mice. In Aim 3 we will identify the gene(s) responsible for Irf6 signaling from the epithelium to the mesenchyme. We will investigate changes in expression of Tbx1 and Fgf8 in lrf6-\- mice. To test whether there is a direct genetic interaction, we will create double heterozygous Irf6/Tbx1 and Irf6/Fgf8 mice. The goal of this research is to understand the signaling pathway that includes IRF6, and how defects in this pathway lead to cleft lip and palate. We will use this information to examine potential gene-gene interactions in human cleft lip and palate patients.