A Phenotype-Optimized Zebrafish Model of Progressive Supranuclear Palsy

摘要 进行性核上性瘫痪(PSP)是一种神经退行性疾病，临床特点是 失去平衡和其他神经症状。跌倒是PSP早期表现和诊断的核心 导致骨折和住院治疗。目前还没有改善平衡或防止疾病进展的治疗方法。 强有力的病理、分子和遗传学证据表明，微量的4重复亚型沉积。 小管相关蛋白Tau(4R-Tau)在PSP病理生理学中的作用目前的模型难以将4R-Tau病理联系起来 追溯到定义PSP的令人衰弱的瀑布。PSP新疗法的开发将使PSP受益匪浅 从一种在负责平衡的神经回路的背景下评估干预措施的方法。 利用我们各个实验室的历史优势，我们共同设计了一种新的 在平衡的背景下对Tau病理进行建模的模型系统。我们的模型系统使用斑马鱼幼体， 一种小型脊椎动物，具有特殊的分子和光学可及性和严格定义的平衡行为。 在未发表的试点实验中，使用了一系列广泛的神经学和行为测试，表明表达 斑马鱼神经元的ING 4R-Tau引起：(I)分子和细胞病理学(Ii)运动和眼球运动 赤字(三)共同类似于PSP的系统性平衡赤字。在这里，我们建议扩展和验证 这款令人兴奋的新车型。 在R61目标中，为了在内部验证我们的模型，我们将开发两个互补的管道来分析平衡 并建立新的转基因品系和方案，以获得对4Rtau表达的时间控制。第一, 我们将使用严格定义的量化行为终端优化平衡分析，以满足 对化学修饰剂或候选基因靶标的有效评估。接下来我们将使用一种新型的光感应式反式 基因表达系统(GAVPO/UAS)，用于特定时间点的4Rtau水平的参数控制。如果我们的 平衡分析和转基因品系达到了确定的成功里程碑，我们将继续进行R33目标。那里, 我们将沿着三个轴线对我们的模型进行外部验证：首先，我们将通过测试是否符合条件来检验结构效度 MAN致病Tau突变增加了观察到的表型的严重性。第二，我们将测试表面效度 通过评估4R-Tau诱导后的病理、神经功能和平衡缺陷。最后，我们将作为 例如，通过在其他模型系统中使用已知的调节互变的化学物质来预测有效性。我们的 团队由一名内科科学家(在临床上)专门研究运动障碍和斑马鱼模型组成 神经退行性变(在实验室中)和一位成功地使用斑马鱼来理解 负责平衡的神经回路的正常发育和功能。我们共同提议建立 并验证一种创新的“表型优化”模型系统，以解决深层次的未得到满足的临床需求： PSP的神经治疗发现与其最终的平衡症状有关。这项工作具有广泛的意义 ICANT提高了我们定义神经退化的一般机制的能力。

Abstract Progressive supranuclear palsy (PSP) is a neurodegenerative disease characterized clinically both by profound loss of balance and other neurological symptoms. Falls are central to early PSP presentation and diagnosis and lead to fractures and hospitalization. No current treatments improve balance or prevent disease progression. Strong pathological, molecular, and genetic evidence implicates deposits of the 4­repeat isoform of the micro­ tubule associated protein Tau (4R­Tau) in PSP pathophysiology. Current models struggle to link 4R­Tau pathol­ ogy to the debilitating falls that define PSP. Development of new therapies for PSP would benefit profoundly from a means to evaluate interventions in the context of the neural circuits responsible for balance. Leveraging the historical strengths of our individual laboratories, we have worked together to design a new model system to model Tau pathology in the context of balance. Our model system uses the larval zebrafish, a small vertebrate with exceptional molecular and optical accessibility and rigorously defined balance behavior. In unpublished pilot experiments have used a wide set of neurological and behavioral tests show that express­ ing 4R­Tau in zebrafish neurons gives rise to: (i) molecular and cellular pathology (ii) locomotor and oculomotor deficits (iii) systematic balance deficits that together resemble PSP. Here we propose to extend and validate this new and exciting model. In the R61 aim, to validate our model internally we will develop two complementary pipelines to assay balance behavior and establish new transgenic lines and protocols to gain temporal control of 4R­Tau expression. First, we will optimize an assay of balance with rigorously­defined quantitative behavioral endpoints suitable for effi­ cient evaluation of chemical modifiers or candidate gene targets. Next we will use a novel light­inducible trans­ gene expression system (GAVPO/UAS) for parametric control of 4R­Tau levels at particular time points. If our balance assay and transgenic lines meet defined milestones for success, we will proceed to the R33 aim. There, we will validate our model externally along three axis: First, we will assay construct validity by testing if a hu­ man pathogenic Tau mutant enhances the severity of observed phenotypes. Second we will assay face validity by evaluating the pathology, neurological and balance deficits following induction of 4R­Tau. Lastly we will as­ say predictive validity by administering chemicals known to modulate tauopathy in other model systems. Our team consists of a physician scientist specializing in movement disorders (in the clinic) and zebrafish models of neurodegeneration (in the lab) and a basic neuroscientist who has successfully used zebrafish to understand normal development and function of neural circuits responsible for balance. Together, we propose to establish and validate an innovative new “phenotype­optimized” model system to address a deep unmet clinical need: neurotherapeutic discovery for PSP in the context of its definitive balance symptoms. The work is broadly signif­ icant as it advances our ability to define general mechanisms of neurodegeneration.