Novel Modulators of TGFß1 signaling in regulation of remyelination by neural stem cells

TGFα1 信号传导在神经干细胞髓鞘再生调节中的新型调节剂

• 批准号: 10544041
• 负责人: Jayshree Samanta
• 金额: $ 38.21万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-01-01 至 2023-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10544041
• 关键词: Ablation; Adult; Binding Sites; Bioinformatics; Brain; CD44 gene; Cell Culture Techniques; Cells; Choline; Chronic; Clinical; Corpus Callosum; Cuprizone; Data; Demyelinating Diseases; Demyelinations; Diet; Disease; Exhibits; Gene Expression; Genes; Glycoproteins; Human; In Vitro; Injections; Knock-out; Knockout Mice; Lesion; Ligands; LoxP-flanked allele; Mediating; Mediator; Modeling; Molecular; Multiple Sclerosis; Mus; Nerve Degeneration; Nonmetastatic; Oligodendroglia; Outcome; Pathway interactions; Population Heterogeneity; Promoter Regions; Recovery of Function; Regulation; Reporting; Role; Signal Pathway; Signal Transduction; Source; Testing; Toxin; Transforming Growth Factor beta; Work; axonal degeneration; cell type; differential expression; dosage; extracellular; glycoprotein NMB; human disease; in vivo; insight; melanoma; multiple sclerosis patient; nerve stem cell; novel; overexpression; paracrine; peripheral blood; prevent; receptor; receptor binding; recruit; remyelination; repaired; response; subventricular zone; therapeutic target; transcription factor; transcriptome sequencing; transcriptomics

ABSTRACT Loss of oligodendrocytes gives rise to demyelination, ultimately resulting in axonal degeneration and debilitating clinical outcomes in diseases like Multiple Sclerosis. While remyelination can prevent neurodegeneration, there are currently no approved therapies for promoting remyelination. Thus, there is an urgent need to identify factors that control remyelination. Neural stem cells in the adult subventricular zone are one of the sources of remyelinating oligodendrocytes. These cells are a heterogeneous population that show diverse responses to signaling pathways in the healthy vs demyelinated brain. We have studied one such pool marked by Gli1, which generates remyelinating oligodendrocytes only in response to demyelination. Our previous work showed that the recruitment and differentiation into oligodendrocytes leading to functional recovery is increased substantially by loss of Gli1 in this pool of neural stem cells; however the molecular mechanisms involved in this repair is not known. Through a transcriptomic analysis comparing gene expression in neural stem cells with and without Gli1 expression, we identified the TGFβ1 pathway as a major regulator of remyelination mediated by neural stem cells. However, the effects of TGFβ1 signaling are context dependent and differ with the cell-type, timing and dosage suggesting the presence of specific modulators of the pathway in different cells. Using a combination of bioinformatic analysis and remyelination studies in mice, we discovered a novel mediator of the TGFβ1 pathway, Gpnmb which is highly expressed along with its receptor CD44 in neural stem cells in response to demyelination. In the first aim, we will define the cell-autonomous function of Gpnmb in neural stem cells and its role in remyelination by neural stem cells. In the second aim, we will determine the impact of paracrine Gpnmb signaling through CD44 receptor on remyelination mediated by neural stem cells. In the third aim, we will elucidate the mechanisms of regulation of Gpnmb by TGFβ1 ligand and reciprocal modulation of the TGFβ1 pathway by Gpnmb. For the remyelination studies, we will use the toxin induced models of demyelination. To define the molecular mechanisms of the TGFβ1-Gpnmb signaling pathway, we will utilize in vitro neural stem cell cultures from adult mouse brain. Together, these studies will help identify therapeutic targets for promoting remyelination.

摘要 少突胶质细胞的损失引起脱髓鞘，最终导致轴突变性和衰弱。 多发性硬化症等疾病的临床结果。虽然髓鞘再生可以防止神经变性， 目前还没有批准的促进髓鞘再生的疗法。因此，迫切需要查明各种因素， 控制髓鞘再生成体室管膜下区的神经干细胞是神经干细胞的来源之一， 髓鞘再生少突胶质细胞这些细胞是一个异质群体，显示出不同的反应， 健康大脑和脱髓鞘大脑中的信号通路。我们已经研究了一个这样的池，标记为Gli 1， 产生再生髓鞘的少突胶质细胞只对脱髓鞘作出反应。我们以前的工作表明， 募集和分化为少突胶质细胞，导致功能恢复， 在这个神经干细胞库中Gli 1的丢失;然而，参与这种修复的分子机制并不 知道的通过转录组学分析比较有和没有Gli 1的神经干细胞中的基因表达 表达，我们确定了TGFβ1途径作为神经干细胞介导的髓鞘再生的主要调节因子。 细胞然而，TGFβ1信号传导的作用是环境依赖性的，并且随着细胞类型、时间和细胞周期的不同而不同。 剂量表明在不同细胞中存在该途径的特异性调节剂。结合使用 通过对小鼠的生物信息学分析和髓鞘再生研究，我们发现了TGFβ1通路的一种新介质， 在神经干细胞中响应脱髓鞘而沿着其受体CD 44高度表达的GPnmb。 在第一个目标中，我们将明确Gpnmb在神经干细胞中的细胞自主功能及其在神经干细胞中的作用。 神经干细胞的髓鞘再生在第二个目标中，我们将确定旁分泌Gpnmb信号传导的影响， 通过CD 44受体对神经干细胞介导的髓鞘再生的影响。在第三个目标中，我们将阐明 TGFβ1配体对Gpnmb的调节机制以及TGFβ1途径的相互调节 GPNMB。对于髓鞘再生研究，我们将使用毒素诱导的脱髓鞘模型。来定义 TGFβ1-Gpnmb信号通路的分子机制，我们将利用体外神经干细胞培养 成年老鼠的大脑。总之，这些研究将有助于确定促进髓鞘再生的治疗靶点。