Identification of a novel pathway that regulates optic nerve myelination and remy

项目总结 在视神经中，少突胶质细胞是唯一的髓鞘生成细胞。髓磷脂提供隔热 以及对RGC轴突的营养支持，并允许正常视力。白斑狼疮的死亡和视神经脱髓鞘 神经是通常损害视力的脱髓鞘疾病的特征，包括视神经炎和多发性 硬化症。控制OL存活和脱髓鞘的信号机制仍然知之甚少。 以前的研究已经确定了无数的细胞外信号和OL细胞表面受体介导OL 生存和分化，但将这些营养信号与下游事件联系起来的内在途径仍然存在 难以捉摸。在我之前的研究中，我通过鉴定转录因子EB(TFEB)有了一个惊人的发现 作为缺失的一环。我发现TFEB在中枢神经系统中的OL系细胞中高表达，包括 视神经。我产生了一种新的TFEB条件性小鼠株系，并在小鼠的大脑中显示了TFEB 强效拮抗髓鞘形成，促进髓鞘形成前OL细胞凋亡 抑制OL成熟。基于这些发现，我建议检验TFEB作为 在无轴突接触或营养的情况下促进细胞凋亡的髓前白斑中的关键感受器 TFEB调节自噬途径以控制OL成熟和髓鞘形成。我会利用 以啮齿动物视神经为模型系统来验证这些假说。在我的K99阶段，我已经确定了 TFEB在啮齿动物视神经髓鞘形成中的表达和作用 TFEB促进早髓鞘OL细胞死亡的分子机制。此外，我还获得了 在我的合作导师的实验室里接受动物外科和老鼠视觉行为分析方面的培训。作为一种 独立调查员，我将利用我在K99阶段获得的专业知识和技术来 全面研究TFEB在视神经髓鞘形成中的作用，并确定其在髓鞘中的作用 视神经炎动物模型的修复。具体地说，我的实验室将利用细胞类型特定的TFEB条件 我已经产生的突变体，从基因上剖析了TFEB在OL发育和 髓鞘形成。我们将进行全基因组RNA测序实验，以确定候选途径 TFEB调控髓鞘形成的OL，并进一步研究一个候选途径，自噬 控制髓鞘形成的途径。最后，我们将确定TFEB通路在视神经中的功能 脱髓鞘和重新髓鞘形成，并进一步调节TFEB通路，促进视神经功能恢复 神经炎动物模型。这项拟议的研究将描述一种新的调节视神经的途径 髓鞘形成，并将决定潜在的机制。通过开发针对TFEB的新药 途径，我们的目标是减轻视神经损伤，促进患者的重新髓鞘形成和视力恢复 患有视神经炎和多发性硬化症。

Project Summery In the optic nerve, oligodendrocytes (OLs) are sole myelin-producing cells. Myelin provides insulation and trophic support for RGC axons and allows for normal vision. Death of OLs and demyelination in the optic nerve are the hallmarks of demyelinating diseases that often impair vision, including optic neuritis and multiple sclerosis. The signaling mechanisms that controls OL survival and demyelination are still poorly understood. Previous studies have identified a myriad of extracellular cues and OL cell surface receptors that mediate OL survival and differentiation but the intrinsic pathways that link these trophic cues to downstream events remain elusive. In my previous studies, I made a striking discovery by identifying the Transcription Factor EB (TFEB) as the missing link. I discovered that TFEB is highly expressed by OL lineage cells in the CNS including the optic nerve. I generated a novel TFEB conditional mouse line and showed that in the mouse brain TFEB powerfully antagonizes myelination by promoting premyelinating OL cell apoptosis and simultaneously inhibiting OL maturation. Based on these findings, I propose to test the hypotheses that TFEB serves as the critical sensor in premyelinating OLs that facilitates cell apoptosis in the absence of axonal contact or trophic support, and that TFEB regulates the autophagy pathway to control OL maturation and myelination. I will utilize the rodent optic nerve as a model system to test these hypotheses. In my K99 phase, I have determined the expression and function of TFEB in developing myelination in the rodent optic nerves, and I have addressed the molecule mechanisms through which TFEB promotes premyelinating OL cell death. In addition, I gained training in animal surgery and mouse visual behavioral assays in my co-mentor's laboratory. As an independent investigator, I will leverage the expertise and techniques that I have acquired in my K99 phase to comprehensively investigate TFEB function in optic nerve myelination, and to determine its roles in myelin repair in optic neuritis animal models. Specifically, my laboratory will utilize cell-type specific TFEB conditional mutants that I have already generated to genetically dissect out the roles of TFEB in OL development and myelination. We will perform whole-genome RNA sequencing experiments to identify the candidate pathways that TFEB regulates in myelinating OLs, and further investigate one candidate pathway, the autophagy pathway in controlling myelination. Finally, we will determine the function of TFEB pathway in optic nerve demyelination and remyelination, and further modulate the TFEB pathway to promote vision recovery in optic neuritis animal models. The proposed research will characterize a novel pathway regulating optic nerve myelination and will determine the underlying mechanisms. By developing new drugs that target the TFEB pathway, our goal is to lessen optic nerve damage and promote remyelination and visual recovery in patients with optic neuritis and multiple sclerosis.