Proteolipid protein suppression for Pelizaeus Merzbacher Disease

摘要 Pelizaeus-Merzbacher病(PMD)是一种严重的X连锁儿童神经退行性疾病 中枢神经系统(CNS)的髓鞘形成。PMD是由功能突变的毒性获得所致 编码中枢神经系统中最普遍的髓鞘蛋白--蛋白脂蛋白的plp1基因。PMD展示了一种 反映广泛的基因异质性的临床表型谱。大多数PLP1变异体， 包括多余的拷贝和各种点突变，导致进行性神经恶化和 死亡，通常发生在童年时期。然而，PLP1缺失的患者和小鼠表现出相对温和的表型， 提示PLP1异常表达的减少可能为PMD提供一种治疗策略 基因分型。在这项建议中，我们将量化反义寡核苷酸(ASO)的生物学活性，以 靶向和抑制PMD小鼠异常蛋白脂蛋白并检测其治疗效果(in 活体)和人体(体外)模型。在R61阶段，我们将使用蛋白质脂蛋白水平作为 药效学标记物，告知ASOS的剂量范围和治疗方案。此外，我们还将测量 PMD模型中表型终点的可变性，以确保所有疗效研究都得到了适当的支持。 在R33阶段，我们将测试ASOS抑制蛋白脂蛋白和增强 精确复制的PMD小鼠模型的髓鞘形成和神经功能。另外， 我们将测试ASOS抑制蛋白脂蛋白和提高人类少突胶质细胞存活的效果 以及在少皮质球体(有组织的3D人类中枢神经系统组织样结构)中的功能 来自PMD患者的特征性诱导多能干细胞系的小组。总的来说，这些研究将 证明靶向PLP1的ASO是否具有足够的生物活性以保证继续治疗 发展。

SUMMARY Pelizaeus-Merzbacher disease (PMD) is a severe X-linked pediatric neurodegenerative disorder impacting myelination in the central nervous system (CNS). PMD results from toxic gain of function mutations in the PLP1 gene which encodes the most prevalent myelin protein, proteolipid protein, of the CNS. PMD exhibits a spectrum of clinical phenotypes that reflect wide genotypic heterogeneity. The majority of PLP1 variants, including supernumerary copies and various point mutations, lead to progressive neurological deterioration and death, often during childhood. However, PLP1-null patients and mice display comparatively mild phenotypes, suggesting that reduction of aberrant PLP1 expression might provide a therapeutic strategy across PMD genotypes. In this proposal we will quantify the biological activity of antisense oligonucleotides (ASOs) to target and suppress aberrant proteolipid protein and measure the resulting therapeutic effect in PMD mouse (in vivo) and human (in vitro) models. During the R61 phase we will use proteolipid protein levels as a pharmacodynamic marker to inform dose ranges and regimens of ASOs. Additionally, we will measure variability of phenotypic endpoints in PMD models to ensure that all efficacy studies are appropriately powered. In the R33 phase, we will test the in vivo efficacy of ASOs to suppress proteolipid protein and enhance myelination and neurological function in a genomically accurate duplication mouse model of PMD. Additionally, we will test the efficacy of ASOs to suppress proteolipid protein and enhance human oligodendrocyte survival and function in oligocortical spheroids (organized 3D human CNS tissue-like structures) from a comprehensive panel of characterized induced pluripotent stem cell lines from PMD patients. Collectively, these studies will demonstrate whether PLP1-targeting ASOs have sufficient biological activity to warrant continued therapeutic development.