Function and Regulation of PMP22 in CMT1A and HNPP

项目总结/摘要 外周髓磷脂蛋白22（PMP 22）基因的重复和缺失导致 髓鞘形成障碍性周围神经病变说明了PMP 22对于周围髓鞘完整性的重要性。 PMP 22复制导致Charcot-Marie-Tooth病1A型（CMT 1A），PMP 22缺失导致 遗传性神经病与压力麻痹易感性（HNPP）。虽然CMT 1A和HNPP是最 常见的遗传性周围神经病，对他们的研究资金不足，目前没有 改善疾病的治疗方法这在很大程度上是由于PMP 22的功能和 PMP 22表达的改变仍不清楚。因此，迫切需要扩大对PMP 22 在髓鞘中，它是如何调节的，以及何时需要精确表达作为改善治疗效果的手段。 CMT 1A和HNPP的潜力。该提案旨在利用尖端技术，包括条件 小鼠模型和超分辨率显微镜，以及细胞粘附和膜生物物理学的知识， 促进对CMT 1A和HNPP病理机制的理解。我的主要假设是， 剂量和脂筏联合控制髓鞘粘附和紧密粘附的定位和组织 连接;在发育过程中最关键的功能。在目标1中，我将确定PMP 22如何 在发育和衰老过程中，超氧化物歧化酶调节周围神经髓鞘中的粘附连接组织 分辨率和电子显微镜。我将通过评估以下因素的影响来帮助解释这些研究： Madin-Darby犬肾（MDCK）中原型粘附和紧密连接上的改变的PMP 22表达 上皮细胞髓鞘中精确表达PMP 22的时间要求也将由以下定义： 产生CMT 1A和HNPP的强大条件性小鼠模型。在目标2中，我将确定如何 棕榈酰化影响PMP 22脂筏的结合和粘附连接的调节，并定义了 使用MDCK和Schwann细胞模型的质膜内的PMP 22的生物物理性质 CMT 1A和HNPP以及先进的生物物理方法。K22职业转型奖将为我提供 额外的培训，指导和细胞粘附，膜生物物理学和显微镜方面的专业知识，从而 使我的研究计划得以实现，并帮助我过渡到独立。培训将补充 我以前在细胞和分子神经生物学方面的训练，以及我目前的外周神经训练， 在第一阶段获得的专业知识将应用于第二阶段更复杂的模型，以扩大机械 续费这些目标的完成将加快我实现发展一个 独立的学术研究生涯研究CMT 1A和HNPP的病理机制， 提高其治疗潜力。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.