Genetic Regulation of Progenitor Cells in Appendicular Skeletal Development

附肢骨骼发育中祖细胞的遗传调控

• 批准号: 9251238
• 负责人: Yasuhiko Kawakami
• 金额: $ 32.3万
• 依托单位: UNIVERSITY OF MINNESOTA
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-04-01 至 2018-09-11
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9251238
• 关键词: Anterior; Cartilage; Cell Cycle; Cell Lineage; Cell Proliferation; Cells; Congenital Abnormality; Congenital Limb Deformities; Cyclin-Dependent Kinase Inhibitor; Cyclin-Dependent Kinase Inhibitor Gene; Cyclin-Dependent Kinases; Cyclins; Data; Defect; Development; Differentiation and Growth; Digit structure; Disease; Distal; Elements; Embryo; Embryonic Development; Event; Femur; Fibroblast Growth Factor; Forelimb; Generations; Genes; Genetic; Genetic Counseling; Genetic Programming; Goals; Growth; Health; Hindlimb; Homeodomain Proteins; Homologous Gene; Human; Injury; Knowledge; Lateral; Limb Bud; Limb Development; Limb structure; Live Birth; Location; Mesenchyme; Mesoderm; Modeling; Molecular; Molecular Abnormality; Morphogenesis; Operating System; Pathway interactions; Phenotype; Positioning Attribute; Process; Proteins; Publications; Regulation; Shapes; Signal Transduction; Skeletal Development; Skeletal system; Skeleton; Stem cells; Structure; System; Testing; Tissues; Tretinoin; Up-Regulation; Zinc Fingers; beta catenin; bone; fibula; gene function; notochord; novel; progenitor; public health relevance; repaired; skeletal; skeletogenesis; tibia

DESCRIPTION (provided by applicant): The appendicular skeletal system represents a paradigm for development of skeletal elements with unique shapes and locations. Moreover, this system provides a platform to study how bone/cartilage in the same position develops into distinct shapes in two types of limbs, namely the forelimbs and hindlimbs. Elucidating how these skeletal elements are generated from progenitor cells is crucial for understanding the development of the appendicular skeletal system. During embryonic development, "the posterior growth zone", the structure located at the posterior of the body, grows and posteriorly extends the body. This process, called the body extension, progressively generates progenitor cells for various tissues, including the lateral plate mesoderm (LPM). Cells in the LPM give rise to the limb bud mesenchyme, which expand and undergo region-specific growth and differentiation, leading to progressive morphogenesis of skeletal elements from the most proximal (stylopod) to the middle (zeugopod) and distal (autopod) region. We obtained preliminary data supporting the idea that genetic systems earlier than limb bud formation regulate generation and expansion of progenitor cells for subsequent development of the appendicular skeletons. Conditional inactivation of Sall4, which encodes a zinc finger containing protein, prior to limb outgrowth, resulted in the loss of proximal-anterior skeletal elements only in the hindlimb, such as the femur, tibia and anterior digits. We also obtained preliminary data, suggesting that cells expressing Isl1, encoding a LIM homeodomain protein, in the hindlimb-forming region contribute to the formation of posterior-distal skeletal elements in hindlimbs, such as fibula and posterior digits. These results suggest that genetic systems by Isl1 and Sall4 operate in the LPM and regulate hindlimb progenitor cells to develop into specific skeletal elements. Furthermore, our preliminary data suggest that, in an earlier, upstream event, combined function of Sall4 and its homolog, Sall1, regulates body extension to generate hindlimb progenitors. The goal of the proposal is to determine the genetic and molecular mechanisms of Sall4, Isl1 and Sall1 operating in progenitor cells. We will have three specific aims for this goal. Aim 1 will test the hypothesis that Sall4 regulates proliferation and survival of hindlimb progenitors through regulation of the cyclin-dependent kinase inhibitor genes. Aim 2 will test the hypothesis that distinct regulation of ss-catenin by Sall4 and Isl1 controls proliferation and/or survival of hindlmb progenitor cells. Aim 3 will test the hypothesis that the combined function of Sall1 and Sall4 controls the formation of the hindlimb progenitors in the LPM through regulation of body extension. Completion of this project will reveal a novel concept that genetic systems regulate the expansion of progenitors in the LPM for development of the appendicular skeletal system in later stages. Elucidating this novel mechanism that regulates appendicular skeletal development will significantly advance our current understanding of appendicular skeletogenesis

描述（由申请人提供）：阑尾骨骼系统代表了开发具有独特形状和位置的骨骼元素的范式。此外，该系统提供了一个平台来研究同一位置的骨/软骨如何在两种类型的肢体中形成不同的形状，即前肢和后肢。阐明这些骨骼元素是如何从祖细胞产生的，对于理解阑尾骨骼系统的发展至关重要。在胚胎发育过程中，“后生长区”（位于人体后部的结构）生长并后部延伸。这个称为身体延伸的过程逐渐生成各种组织的祖细胞，包括侧板中胚层（LPM）。 LPM中的细胞会引起肢体芽中充质，该细胞扩展和经历了区域特异性的生长和分化，从而导致骨骼元素从最近端（Stylopod）到中间（Zeugopod）到中间（Zeugopod）和远端（Autopod）区域的骨骼元素进行性形态发生。我们获得了初步数据，该数据支持以下观点：遗传系统早于肢体芽形成调节祖细胞的产生和扩展，以便随后发展阑尾骨骼。在肢体生长之前编码含有蛋白质的锌指的SALL4的条件灭活，导致仅在后肢的后肢，例如股骨，胫骨和前数字，导致近端骨骼元素的损失。我们还获得了初步数据，这表明在后肢形成区域中表达ISL1并编码LIM同源域蛋白的细胞有助于形成后远的后端骨骼元素，例如腓骨和后数字。这些结果表明，ISL1和SALL4的遗传系统在LPM中起作用，并调节后肢祖细胞以发展为特定的骨骼元素。此外，我们的初步数据表明，在早期的上游事件中，SALL4及其同源物SALL1的合并功能调节身体扩展以产生后肢祖细胞。该提案的目的是确定在祖细胞中运行的SALL4，ISL1和SALL1的遗传和分子机制。我们将针对这个目标有三个具体的目标。 AIM 1将检验以下假设：SALL4通过调节细胞周期蛋白依赖性激酶抑制剂基因来调节后肢祖细胞的增殖和存活。 AIM 2将检验以下假设：SALL4和ISL1对SS-catenin的明显调节控制HindLMB祖细胞的增殖和/或存活。 AIM 3将检验以下假设：SALL1和SALL4的联合功能通过调节身体扩展来控制LPM中后肢祖细胞的形成。该项目的完成将揭示一个新的概念，即遗传系统调节LPM中祖细胞的扩展，以在后期阶段开发阑尾骨骼系统。阐明调节阑尾骨骼发育的这种新型机制将显着提高我们目前对阑尾骨骼生成的理解