Ion channel mediated control of mophogen signaling for craniofacial development in mammals

项目总结 创伤、肿瘤和头面部疾病后需要进行颅面重建。骨移植和 合成支架的成功有限。骨形态发生蛋白(BMPs)刺激 骨骼和软骨的产生，是牙齿发育、腭部闭合和正常所必需的 头面部发育。BMP也是骨修复所必需的，可以刺激干细胞 软骨和骨骼的命运。我们最近发现，离子通道控制着果蝇BMP的分泌。 我们的假设是，离子通道活动调节哺乳动物体内BMP的分泌。 机制。为了支持这一假设，钾通道功能受损的小鼠数量减少 BMP信号的激活以及与BMP突变体相似的表型。如果我们的假设被证明是正确的，电学 影响离子通道活性的刺激或小分子可以提供控制BMP释放的能力 骨骼和牙齿的正常发育和再生。我们的长期目标是使用一种新的方法来 操纵细胞分泌内源性BMP以促进头面部骨骼发育。第一步 这一目标是确定离子通道参与BMP信号转导的机制。 哺乳动物。在这个方案中，我们使用Kir2.1钾(K+)通道来确定分子连接 哺乳动物体内离子导电性和BMP信号之间的关系。携带Kir2.1基因突变的人类和小鼠 先天性头面部缺陷，包括腭裂、牙齿缺陷和小颌症，表明这一点 经络在颅面发育中起着至关重要的作用。目标1确定Kir2.1在BMP中的作用位置 在哺乳动物中使用上位性和拯救实验的途径。Aim 2测试了离子通道的假设 调节哺乳动物的BMP分泌，就像它们对苍蝇所做的那样。在其他类型的细胞中，离子通道影响细胞内 钙来调节分泌。在目标3中，我们确定了细胞内钙离子如何影响BMP的释放。这个 拟议的实验将为未来利用离子通道潜力的研究奠定基础 刺激组织生长和再生。

PROJECT SUMMARY Craniofacial reconstruction is required after trauma, tumors, and for craniofacial disorders. Bone grafts and synthetic scaffolds have resulted in limited success. Bone morphogenetic proteins (BMPs) stimulate the production of bone and cartilage, and are necessary for tooth development, palate closure and normal craniofacial development. BMPs are also required for bone repair and can stimulate stem cells to take on cartilage and bone fate. We recently discovered that ion channels control the secretion of BMP in the fruit fly. Our hypothesis is that ion channel activity regulates BMP secretion in mammals in a conserved mechanism. In support of this hypothesis, mice with disrupted potassium channel function have decreased activation of BMP signaling and similar phenotypes to BMP mutants. If our hypothesis proves correct, electrical stimuli or small molecules that affect ion channel activity may provide the ability to control release of BMP for proper bone and tooth development and regeneration. Our long-term goal is to use a novel approach of manipulating cells to secrete endogenous BMP to encourage craniofacial bone development. The first step towards this goal is to determine the mechanism by which an ion channel contributes to BMP signaling in mammals. In this proposal, we use the Kir2.1 potassium (K+) channel to determine the molecular connection between ion conductivity and BMP signaling in mammals. Humans and mice with mutations in Kir2.1 have congenital craniofacial defects including cleft palate, dental defects, and micrognathia showing that this channel plays an essential role in craniofacial development. Aim 1 determines where Kir2.1 acts in the BMP pathway in mammals using epistasis and rescue experiments. Aim 2 tests the hypothesis that ion channels regulate BMP secretion in mammals as they do in flies. In other cell types, ion channels influence intracellular calcium to regulate secretion. In Aim 3, we determine how intracellular calcium influences BMP release. The proposed experiments will lay a foundation for future studies to harness the potential of ion channels to stimulate tissue growth and regeneration.