The role of extracellular matrix in axon routing

细胞外基质在轴突路由中的作用

• 批准号: 10745085
• 负责人: Reyna I Martínez-De Luna
• 金额: $ 40.75万
• 依托单位: UPSTATE MEDICAL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-30 至 2027-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10745085
• 关键词: ADGR1 gene; Address; Adhesions; Anatomy; Antibodies; Axon; Basement membrane; Brain; Brain region; Cell Polarity; Cells; Cellular Morphology; Complex; Coupled; Cues; Data; Depth Perception; Development; Dominant-Negative Mutation; Dystroglycan; Extracellular Matrix; Future; Goals; Growth; In Vitro; Integrins; Ipsilateral; Knowledge; Label; Laminin; Laminin Receptor; Mediating; Membrane; Methods; Microscopy; Modeling; Molecular; Morphology; Mus; Neuroglia; Neurons; Optic Chiasm; Optic tract structure; PARD6A gene; Pattern; Phase; Proliferating; Proteins; Radial; Regulation; Resolution; Retinal Ganglion Cells; Role; Route; Side; Signal Transduction; Spatial Distribution; Surface; Techniques; Testing; Thinness; Time; Tissues; Vascular Endothelial Growth Factors; Vision; Visual System; Work; axon growth; axon guidance; axon regeneration; brain cell; experimental study; in vivo; information organization; innovation; insight; receptor; retinal axon; retinal ganglion cell regeneration; segregation; spatiotemporal; transmission process

Project Summary/Abstract Vision, in general, and stereopsis, in particular, depends on the selective decussation of retinal ganglion cell axons and their termination in an orderly topographic manner. Axonal decussation is directed by the radial glia and midline line neurons at the optic chiasm. The radial glia and midline neurons attach to the pial basement membrane (PBM), a cell adherent, highly organized extracellular matrix sheet that forms the basal surface of the brain including the chiasm. A key component of the PBM are laminins. In other brain regions laminins containing the 2 subunit (2 laminins) provide environmental cues that control tissue and cellular organization including polarity, proliferation, and differentiation. We hypothesize that 2 laminins in the PBM of the chiasm function to polarize the radial glia and midline neurons. This polarization, in turn, regulates the spatial organization of guidance cues thereby regulating axon decussation. Consistent with this hypothesis, we found that loss of 2 laminins from the PBM decreased axonal decussation resulting in an increased ipsilateral projection. We will critically test this hypothesis in three aims. In Aim 1 we will determine the role of 2 laminins in the control of axonal guidance cue expression during the early, peak, and late phases of axon growth. In Aim 2, we will determine which laminin receptors are required for the polarity of radial glial cells and axon decussation using a combination of in vivo and in vitro approaches. Our in vivo experiments will employ cell specific deletion of laminin receptors, while our in vitro experiments will employ a technically innovative organotypic approach using function blocking techniques. In Aim 3, we will determine how 2 laminins control the radial glia and midline neuron cell polarity using sparse labeling of the cells and high-resolution microscopy. The experiments proposed here will define the role of the β2 laminins during optic chiasm and tract formation. The findings from this work will pave the way to exploit cell-matrix interactions for the development of rational strategies to promote the guided growth and decussation of regenerating retinal ganglion cell axons.

项目摘要/摘要 通常，视觉，尤其是立体原理，取决于残留神经节细胞的选择性脱落 轴突及其以有序的地形方式终止。轴突延伸是由径向神经胶质引导的 和中线线神经元处于视神经chiasm处。径向神经胶质和中线神经元附着在丘陵地下室 膜（PBM），一种粘附的，高度有条理的细胞外基质片，形成了基本表面 大脑在内，包括chiasm。 PBM的关键成分是层粘连蛋白。在其他大脑区域层粘连蛋白中 2亚基（2层粘连蛋白）提供了控制组织和细胞组织的环境线索 极性，增殖和分化。我们假设CHIASM函数的PBM中的2层粘连蛋白 极化径向神经胶质和中线神经元。这种两极分化反过来调节 指导线索，从而调节轴突decuse。与这一假设一致，我们发现2的损失 来自PBM的层粘连蛋白降低了轴突衰减，导致同侧投射增加。我们将 批判性地检验了三个目标。在AIM 1中，我们将确定2层粘连蛋白在控制中的作用 轴突生长的早期，峰值和晚期阶段的轴突引导表达。在AIM 2中，我们将 确定使用A径向神经胶质细胞的极性和使用A轴突的极性需要哪种层粘连蛋白受体 体内和体外方法的组合。我们的体内实验将雇用层粘连蛋白的特定细胞缺失 接收器，而我们的体外实验将使用功能采用技术创新的有机方法 阻止技术。在AIM 3中，我们将确定2层粘连蛋白如何控制径向神经胶质细胞和中线神经元细胞 使用细胞稀疏标记和高分辨率显微镜的极性。这里提出的实验将 定义β2层粘连蛋白在视觉裂痕和道形成过程中的作用。这项工作的发现将铺路 利用细胞 - 矩阵相互作用以发展理性策略以促进指导增长的方法 以及重生的视网膜神经节细胞轴突的延迟。