Who is to blame? Investigating Genes within the 22q11.2 Deletion Region as potential Risk Factors for Parkinson's Disease using Human iPS Cells and CRISPR Perturbation

帕金森病（PD）是世界上第二大常见的神经退行性疾病。然而，PD的发病机制尚不完全清楚，治疗PD仅限于对症治疗，这可能导致不良的长期副作用。了解和治疗PD的主要限制是其具有遗传和环境风险因素的异质性病因，以及当前PD模型不能完全概括该疾病的所有临床和神经病理学相关方面的挑战。新的体外人源性干细胞模型的发展为PD的发病机制提供了新的线索，并证实了PD的神经发育与神经变性的联系。发现和研究导致神经发育缺陷和PD发展风险增加的新的遗传危险因素可能为更好地了解PD的发病机制提供切入点。直到最近，最常见的缺失综合征之一（约1:20 00-4,000活产）22q11.2DS才被发现是发生早发性PD的重要遗传风险因素。由于与散发性PD患者相比，22q11.2 ds的PD患者可以出现相似的症状，这表明22q11缺失区受影响基因的失调引发了常见的疾病机制和途径。我们假设，鉴定22q.11.2缺失中导致22q.11.2 ds发育缺陷的基因，将有助于发现PD病理中涉及的新靶基因，并可能揭示对开发未来治疗策略至关重要的机制。该研究的总体目标是增加我们对22q11.2缺失区域内基因及其在22q11.2 ds和22q11.2 ds PD中的潜在作用的理解。[目的1]我将利用来自22q11.2DS患者的人类干细胞的神经元构建与22q11.2DS相关的体外神经网络，并利用一种新型的高含量微电极阵列芯片，通过高含量成像、分子生物学读数和电生理记录来探测良好描述的疾病相关表型。[目的2]我将进一步通过基因克隆产生表达集群规则间隔短回文重复序列激活（CRISPRa）或干扰（CRISPRi）机制的iPSCs，以调节22q11DS内内源性位点的基因表达。[目的3]这将使我能够通过在发达的神经网络中使用crispr修饰子筛选，识别与22q11.2 ds PD检测到的表型（在目标1中）相关的22q11.2缺失中的特定基因。

Parkinson’s disease (PD) is the second most common neurodegenerative disorder worldwide. Still, the pathogenesis of PD is incompletely understood, and treating PD is limited to symptomatic therapies, which can lead to undesirable long-term side effects. Major limitations in understanding and treating PD is its heterogeneous etiology with genetic as well as environmental risk factors and the challenge that current models of PD do not fully recapitulate all clinical and neuropathological relevant aspects of the disease. The development of new human-derived stem cell models in vitro shed new light on PD pathogenesis and confirmed a neurodevelopmental link to neurodegeneration of PD. Discovery and investigation of new genetic risk factors contributing to neurodevelopmental defects and increased risk for the development of PD might provide an entry point towards better understanding PD pathogenesis.Only recently one of the most common deletion syndromes (~1:2,000-4,000 live births) the 22q11.2DS was found to constitute a significant genetic risk factor for developing early-onset PD. Since PD patients with 22q11.2DS can develop similar symptoms as compared to patients with sporadic PD, this indicates common disease mechanisms and pathways triggered by the dysregulation of affected genes in the 22q11 deletion region. We hypothesize that identifying genes within the 22q.11.2 deletion that are responsible for developmental defects described for 22q.11.2DS will enable the discovery of new target genes involved in PD pathology and might bear the potential to uncover mechanisms that are essential in developing future treatment strategies.The overall goal of this fellowship is to increase our understanding of genes within the 22q11.2 deletion region and their potential role in 22q11.2DS and 22q11.2DS PD. [Objective 1] I will build an in vitro neuronal network relevant for 22q11.2DS with neurons derived from human stem cells from 22q11.2DS patients and probe for well-described disease-associated phenotypes by using high-content imaging, molecular biological readouts, and electrophysiological recordings with a novel high-content microelectrode array chip. [Objective 2] I will further generate iPSCs expressing Clustered Regularly Interspaced Short Palindromic Repeats activation (CRISPRa) or interference (CRISPRi) machinery by genetic cloning to regulate gene expression from endogenous loci within the 22q11DS. [Objective 3] This will allow me to identify specific genes inside the 22q11.2 deletion involved in phenotypes detected (in Objective 1) for 22q11.2DS PD by employing a CRISPR-modifier screen in the developed neuronal networks.