Modulation of glial diversity and functional heterogeneity concerning brain activity by the lipoprotein receptor-related protein 1 (LRP1) receptor and the glycoprotein of the extracellular matrix tenascin-C

脂蛋白受体相关蛋白 1 (LRP1) 受体和细胞外基质腱蛋白-C 糖蛋白对大脑活动的神经胶质多样性和功能异质性的调节

• 批准号: 254968232
• 负责人: Professor Dr. Andreas Faissner
• 金额: --
• 依托单位: Lehrstuhl für Zellmorphologie und Molekulare Neurobiologie
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2014
• 资助国家: 德国
• 起止时间: 2013-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/254968232?language=en
• 关键词: Modulation; glial; diversity; functional; heterogeneity

During the first funding period the laboratory has shown that the complex 487LeX and 5750LeX glycans of the LewisX (LeX) family are differentially expressed on the surface of radial glia stem and glial progenitor cells and permit the enrichment of glial subpopulations. The glycoprotein of the extracellular matrix tenascin C (Tnc) and the lipoprotein receptor related protein 1 (LRP1) were identified as carrier proteins. Tnc is a constituent of the stem cell niche matrisome and regulates the maturation of astrocyte progenitors. Applying digital time lapse video microscopy we could show that Tnc modulates the lineage trees and the cell cycle of embryonic spinal cord glial stem and progenitor cells. Preliminary data suggest the adult behave differently than the embryonic glial stem and progenitor cells. The functional heterogeneity of the micro milieu of neural stem cells will be addressed during the second funding period with reference to Tnc. LRP1 is a multifunctional receptor with multiple ligands, including particular components of the ECM. We could show that the deletion of LRP1 from glial stem and progenitor cells impairs neurogenesis and the generation of oligodendrocytes, and favours the differentiation of astrocytes. This effect relies partly on LRP1 dependent signal transduction, rather than on endocytosis. Selective deletion of LRP1 from cortical radial resulted in a severe neurological phenotype. Beginning with the third postnatal week increasing neuronal excitability and epileptic seizures leading to increased mortality were detected. Based on these results and preliminary data, we plan to investigate glial heterogeneity and its impact on neural activity on a mechanistic basis. The following aims will be addressed: i) the heterogeneity of embryonic and adult glial stem and progenitor cells will be explored with regard to their differential response to Tnc containing microenvironments using digital time lapse video microscopy; ii) the expression of the 487LeX and 5750LeX glycans in the adult CNS will be monitored and corresponding glial populations will be characterized; iii) the functional relevance of LRP1 in astroglial subpopulations with respect to overall CNS activity will be examined by conditional deletion in the GLASTCre/wtLRP1fl/flReporterfl/fl mouse model; iv) the functional significance of LRP1 in NG2 cell subpopulations with respect to overall CNS activity will be analysed by conditional deletion in the NG2Cre/wtLRP1fl/flReporterfl/fl mouse model. The project combines genetic, cell biological and biochemical approaches to examine the generation of glial heterogeneity and its influence on overall brain activity in a developmental perspective.

在第一个资助期，实验室发现leisX(Lex)家族的487LeX和5750LeX复合体糖链在放射状神经胶质干细胞和神经胶质前体细胞表面有差异表达，并允许神经胶质细胞亚群的丰富。细胞外基质TNC的糖蛋白(TNC)和脂蛋白受体相关蛋白1(LRP1)被鉴定为载体蛋白。TNC是干细胞微环境的一个组成部分，调节星形胶质细胞前体细胞的成熟。应用数字时间推移视频显微镜，我们可以显示TNC调节了胚胎脊髓神经胶质干细胞和祖细胞的细胞周期和谱系树。初步数据表明，成体细胞的行为与胚胎神经胶质干细胞和祖细胞不同。神经干细胞微环境的功能异质性将在第二个资助期内参照跨国公司加以解决。LRP1是一种多功能受体，具有多个配体，包括ECM的特定成分。我们可以证明，从胶质干细胞和前体细胞中缺失LRP1会损害神经发生和少突胶质细胞的生成，并有利于星形胶质细胞的分化。这种作用部分依赖于LRP1依赖的信号转导，而不是内吞作用。从皮质放射状区域选择性缺失LRP1导致了严重的神经表型。从出生后第三周开始，检测到神经元兴奋性增加和癫痫发作导致死亡率增加。基于这些结果和初步数据，我们计划从机制上研究神经胶质细胞的异质性及其对神经活动的影响。将致力于以下目标：i)将利用数字时间推移视频显微镜研究胚胎和成人神经胶质干细胞和前体细胞对含有TNC的微环境的差异反应的异质性；ii)将监测487LeX和5750LeX多糖在成人中枢神经系统中的表达，并将表征相应的神经胶质细胞群体；iii)将在GLASTCre/wtLRP1fl/flReporterfl/fl小鼠模型中通过条件缺失来检验LRP1在星形胶质细胞亚群中与整体中枢神经系统活动的功能相关性；IV)在NG2Cre/wtLRP1fl/flReporterfl/fl小鼠模型中，将通过条件性缺失来分析NG2细胞亚群中LRP1相对于整体中枢神经系统活动的功能意义。该项目结合了遗传学、细胞生物学和生物化学的方法，从发育的角度研究神经胶质异质性的产生及其对整体大脑活动的影响。