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

 描述(申请人提供)：创伤、肿瘤和颅面部疾病后需要颅面重建。骨移植和合成支架的成功有限。骨形态发生蛋白(BMPs)刺激骨和软骨的生成，对牙齿发育、腭部闭合和正常的颅面发育是必不可少的。BMP也是骨修复所必需的，可以刺激干细胞形成软骨和骨的命运。我们的假设是，离子通道活动以一种保守的机制调节哺乳动物BMP的分泌。如果我们的假设被证明是正确的，影响离子通道活动的电刺激或小分子可能提供控制BMP释放的能力，以促进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来促进头面部骨骼的发育。我们最近发现，离子通道控制着果蝇BMP的分泌。迈向这一目标的第一步是确定离子通道如何促进哺乳动物的头面部发育。在这个建议中，我们使用Kir2.1钾(K+)通道来确定哺乳动物离子电导和发育信号之间的分子联系。Kir2.1基因突变的人类和小鼠都有先天性颅面缺陷，包括腭裂、牙齿缺陷和小颌症，这表明这一通道在颅面发育中起着至关重要的作用。目标1定义了需要Kir2.1的腭闭合的发育过程(增殖、凋亡、腭架融合、分化和/或 骨化)，并测试了Kir2.1在小鼠体内调节BMP信号的假设。AIM 2确定了需要Kir2.1才能发育成腭部的细胞类型。在目标3中，我们操纵离子通道功能来验证细胞去极化可以增加BMP分泌的假设。拟议的实验将为未来的研究奠定新的基础，以利用不可兴奋细胞中的离子通道潜力来刺激组织生长和再生。

 DESCRIPTION (provided by applicant): 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. Our hypothesis is that ion channel activity regulates BMP secretion in mammals in a conserved mechanism. 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. We recently discovered that ion channels control the secretion of BMP in the fruit fly. The first step towards this goal is to determine how ion channels contribute to craniofacial development in mammals. In this proposal, we use the Kir2.1 potassium (K+) channel to determine the molecular connection between ion conductivity and developmental 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 defines the developmental processes in palate closure that require Kir2.1 (proliferation, apoptosis, palate shelf fusion, differentiation, and/or ossification) and tests the hypothesis that Kir2.1 modulates BMP signaling in mice. Aim 2 identifies the cell types that require Kir2.1 for palate development. In Aim 3, we manipulate ion channel function to test the hypothesis that cellular depolarization can increase BMP secretion. The proposed experiments will lay a new foundation for future studies to harness the potential of ion channels in non- excitable cells to stimulate tissue growth and regeneration.