Role of Irf6 in palatal epithelium

描述(申请人提供)：上颚分隔口腔和鼻腔，并允许在进食和饮水的同时进行呼吸。两大类细胞类型在腭部发育过程中是至关重要的；覆盖腭架的上皮细胞层和成为结缔组织的间充质细胞，最终提供支持和完整性。在人类和小鼠中，这两个细胞层中的任何一个的功能障碍都会导致分裂，这是一种常见的发育缺陷，会造成严重的出生后后果。乳沟可能导致喂养困难，并在关键的新生儿时期无法增加或保持体重。我们的研究小组发现干扰素调节因子6(IRF6)是导致人类唇裂的主要原因。我们感兴趣的是确定由于IRF6基因突变导致的分裂的机制，并设计干预措施来预防这种出生缺陷。为了实现这一目标，我们的实验室开发了一个小鼠模型。到目前为止，我们的研究揭示了关于IRF6及其在腭部发育中的作用的几个重要事实。首先，我们知道IRF6是角质形成细胞增殖和分化的重要调节因子，角质形成细胞是一种上皮细胞。其次，我们证明了IRF6在腭部发育过程中的表达最强，在对腭部形成至关重要的周皮和内侧边缘上皮(MEE)中。第三，我们知道IRF6剂量的变化会导致小鼠的裂隙和口腔粘连。最后，我们设计了实验室方案和小鼠模型来控制腭部上皮细胞中IRF6的浓度。基于这些事实，我推测IRF6在周皮和MEE中剂量的变化将影响腭部的发育。在目标I中，我的目标是减少其他正常小鼠的MEE细胞中IRF6的剂量，并分析随之而来的腭部发育的变化。根据以前的数据和初步发现，我预测由于MEE和IRF6在这一过程中的重要性，腭部发育不会结束。在AIM II中，我的目标是使用腺病毒载体将Irf6运送到Irf6缺陷胚胎的周皮细胞。在这些实验中，我预测IRF6传递到 周皮将挽救细胞功能，导致口腔粘连显著减少。 这项工作具有技术、生物学和临床意义。从技术上讲，我已经提出了一种将基因输送到口腔的方案，这对其他口腔病理和基因可能有用。我们还创造了一个IRF6条件等位基因，可以用来分析IRF6在其他组织和不同时间点的功能。生物学上，我们已经提出了高度复杂的周皮和MEE的基因操作方案，以检验它们作为IRF6的功能在腭部发育中的特殊作用。临床上，AIM II提供了 在胚胎发育过程中减轻或防止裂隙形成的主要实验。

DESCRIPTION (provided by applicant): The palate separates the oral and nasal cavity and allows breathing to occur alongside eating and drinking. Two broad categories of cell types are critical during palatal development; an epithelial cell layer that covers the palatal shelves and mesenchymal cells that become connective tissue, ultimately providing support and integrity. In humans and mice, dysfunction of either of these cell layers leads to clefting, a common developmental defect with serious postnatal consequences. A cleft can lead to feeding difficulty and the inability to gain or maintain weight at critical neonatal periods. Our group identified Interferon Regulatory Factor 6 (IRF6) as a major cause of clefting in humans. We are interested in identifying the mechanisms of clefting due to mutations in IRF6 and in designing interventions to prevent this birth defect. To realize this goal, our lab developed a mouse model. Thus far, our studies uncovered several important facts about Irf6 and its role in palatal development. First, we know that Irf6 is an essential regulator of proliferation and differentiation in keratinocytes, type of epithelial cell. Second, we demonstrated that Irf6 is expressed most robustly during palatal development in the periderm and Medial Edge Epithelium (MEE), epithelial cells that are critical for palatal formation. Third, we know that changes in Irf6 dose lead to clefting and oral adhesions in the mouse. Finally, we engineered laboratory protocols and mouse models to manipulate the concentration of Irf6 in palatal epithelial cells. Based on these facts, I hypothesize that changes in Irf6 dose in the periderm and MEE will affect palatal development. In Aim I, my goal is to reduce Irf6 dose in the MEE cells of otherwise normal mice and analyze the changes in palatal development that ensue. Based on previous data and preliminary findings, I predict that palatal development will not conclude due to the importance of the MEE and Irf6 in the process. In Aim II, my goal is to deliver Irf6 using an Adenoviral vehicle to periderm cells of Irf6-deficient embryos. In these experiments, I predict that Irf6 delivery to the periderm will rescue cellular function, leading to a significant decrease in oral cavity adhesions. This work has technical, biological and clinical significance. Technically, I have proposed a gene delivery protocol to the oral cavity, something that can be useful to other oral pathologies and genes. We have also created an Irf6 conditional allele, which can be used to assay the function of Irf6 in other tissues and at different timepoints. Biologically, we have proposed highly sophisticated gene manipulation protocols for the periderm and the MEE to examine their specific utility in palatal development as a function of Irf6. Clinically, Aim II provides proof-of principal experiments in mitigating the severity or preventing cleft formation during embryologic development.