Function and Regulation of PMP22 in CMT1A and HNPP

项目摘要/摘要 外周血髓鞘蛋白22(PMP22)基因的复制和缺失均可引起 髓鞘变性周围神经病说明PMP22对于周围髓鞘完整性的重要性。 PMP22复制导致1A型Charcot-Marie-Tooth病(CMT1A)和PMP22缺失导致 遗传性神经病伴压力性瘫痪(HNPP)。虽然CMT1A和HNPP是最多的 常见的遗传性周围神经病，对它们的研究资金不足，目前没有 疾病修正疗法。这在很大程度上是由于PMP22的功能和 改变的PMP22表达仍不清楚。因此，迫切需要扩展关于PMP22的知识 在髓鞘中的作用，它是如何调节的，以及何时需要精确表达作为改善治疗的手段 CMT1A和HNPP的潜力。这项提议旨在利用尖端技术，包括有条件的 小鼠模型和超分辨率显微镜，以及细胞黏附和膜生物物理学的知识 进一步了解CMT1a和HNPP的发病机制。我的中心假设是PMP22基因 剂量和脂筏结合支配髓鞘黏附和紧密的定位和组织 连接点；在发展过程中最关键的功能。在目标1中，我将确定PMP22如何 SUBER对周围神经髓鞘发育衰老过程中黏附连接组织的调节作用 分辨率和电子显微镜。我将通过评估这些研究的效果来帮助解释这些研究 PMP22在Madin-Darby犬肾脏典型黏附和紧密连接上的表达变化 上皮细胞。髓鞘中精确表达PMP22的时间要求也将通过以下方式定义 生成强大的CMT1A和HNPP的条件小鼠模型。在目标2中，我将决定如何 棕榈酰化影响PMP22脂筏结合和黏附连接的调节，并定义 用MDCK和Schwann细胞模型研究PMP22在质膜中的生物物理性质 CMT1a和HNPP以及先进的生物物理方法。这个K22职业转折奖将为我提供 在细胞黏附、膜生物物理学和显微镜方面的额外培训、指导和专门知识，从而 使我能够进行拟议的研究，并促进我向独立的过渡。这一培训将是对 我以前接受的细胞和分子神经生物学培训，以及现在的周围神经培训，以及 在第一阶段获得的专业知识将在第二阶段应用于更复杂的模型，以扩展机械 细节。完成这些目标将加快我的长期目标，即发展一个 研究CMT1A和HNPP致病机制的独立学术研究生涯 提高他们的治疗潜力。该奖项提供的培训和指导将扩大我的 技术技能和专业知识，使我成为一名成功的独立调查员。

Project Summary/Abstract The fact that both duplication and deletion of the Peripheral Myelin Protein 22 (PMP22) gene cause dysmyelinating peripheral neuropathy illustrates the importance of PMP22 for peripheral myelin integrity. PMP22 duplication causes Charcot-Marie-Tooth Disease Type 1A (CMT1A) and PMP22 deletion causes Hereditary Neuropathy with Liability to Pressure Palsies (HNPP). Although CMT1A and HNPP are the most common inherited peripheral neuropathies, research on them is underfunded and there are currently no disease-modifying treatments. This is largely due to the fact that PMP22 function and the consequence of altered PMP22 expression remain unclear. Thus, there is a critical need to expand knowledge of what PMP22 does in myelin, how it is regulated and when precise expression is required as a means to improve therapeutic potential of CMT1A and HNPP. This proposal aims to utilize cutting-edge techniques, including conditional mouse models and super resolution microscopy, and knowledge of cell adhesion and membrane biophysics to advance understanding of CMT1A and HNPP pathomechanisms. My central hypothesis is that PMP22 gene dosage and lipid raft association govern localization and organization of myelin adherens and tight junctions; a function that is most critical during development. In Aim 1, I will determine how PMP22 regulates adhesion junction organization in peripheral nerve myelin during development and aging with super resolution and electron microscopy. I will aid the interpretation of these studies by evaluating the effects of altered PMP22 expression on prototypical adherens and tight junctions in Madin-Darby Canine Kidney (MDCK) epithelial cells. The temporal requirement for precise PMP22 expression in myelin will also be defined by generating powerful conditional mouse models of CMT1A and HNPP. In Aim 2, I will determine how palmitoylation impacts PMP22 lipid raft association and regulation of adhesion junctions and define the biophysical properties of PMP22 within the plasma membrane using MDCK and Schwann cell models of CMT1A and HNPP and advanced biophysical methods. This K22 Career Transition Award will provide me with additional training, mentorship and expertise in cell adhesion, membrane biophysics and microscopy, thereby enabling my proposed research and facilitating my transition to independence. This training will complement my previous training in cell and molecular neurobiology and my current peripheral nerve training, and the expertise acquired during Phase I will be applied to more complex models in Phase II to expand mechanistic details. Completion of these aims will accelerate progress towards my long-term goal of developing an independent academic research career studying pathomechanisms of CMT1A and HNPP as a means to improve their therapeutic potential. The training and mentorship provided by this award will expand my technical skills and expertise, positioning me for success as an independent investigator.