Modeling of early-onset retinal dystrophy development in optic vesicle containing-brain organoids

先天性视网膜疾病，包括Leber先天性黑色素沉着症(LCA)/早发性严重视网膜营养不良和眼皮肤白化病(OCA)，是一种遗传性视网膜疾病，每年影响约150名活产儿。这些先天性视网膜疾病发生在视网膜发育的早期，其疾病发展的机制尚不清楚。因此，在与疾病相关的实验系统中支持触发疾病发展的缺陷细胞机制是设计治疗策略的先决条件。一个重要的限制因素是缺乏一个实验系统，从生理上重现发育中的前脑的早期视网膜发生。这一优先项目的第一个资助期支持我们生成3D脑器官，以局部受限的方式发育两侧对称的视泡(OVB-器官)。OVB-类器官培养方法是稳健的，因为我们可以从五个独立的IPSCs捐赠者那里产生大量OVB-类有机物。在目前的资助期间，我们将使用患者特有的OVB有机化合物来模拟LCA和OCA的发育疾病机制，并测试药物和基因增强策略是否可以缓解疾病的表型。为此，我们通过与人类遗传学家的合作，确定了携带SPATA7、CEP290(导致LCA)和HPS1(导致OCA)突变的患者。值得注意的是，这些患者的突变是非综合征性的，这意味着这些突变不会影响大脑发育过程，而只影响视网膜。这项研究计划结合我们的跨学科专业知识，剖析导致患者特定OVB有机体疾病发展的放松调控的细胞通路，并评估潜在的基于基因的治疗方法。为了实现这一最终目标，我们将1。产生血管化的OVB-有机物(v-OVB-有机物)以延长存活时间，以产生成熟的视网膜细胞类型。生成患者特异性的v-OVB-有机物，以剖析由于SPATA7、CEP290和HPS1突变导致的LCA和OCA的发育病理生理。确定翻译通读剂和AAV基因增强在减轻疾病表型方面的影响。总体而言，凭借我们使用新型3D脑-视网膜混合有机体的跨学科专业知识，我们将识别导致LCA和OCA的视网膜发育障碍的非调控细胞通路，并提供新的治疗方案。

Congenital retinal disorders, including Leber Congenital Amaurosis (LCA) /early-onset severe retinal dystrophy and Oculocutaneous Albinism (OCA), are genetically inherited retinal disorders affecting ~150 live births every year. These congenital retinal disorders occur at the early onset of retinal development, for which the mechanisms of disease development remain unknown. Therefore, underpinning the defective cellular mechanisms that trigger the disease development in a disease-relevant experimental system is a prerequisite to designing therapeutic strategies. A significant limiting factor for this is the lack of an experimental system that physiologically recapitulates the early retinogenesis from the developing forebrain. The first funding period of this priority prograhas supported us to generate 3D brain organoids developing bilaterally symmetric optic vesicles in a topographically restricted manner (OVB-organoids). The OVB-organoid culturing method is robust as we could generate numerous OVB-organoids from five independent iPSCs donors. In the current funding period, we will model the developmental disease mechanisms of LCA and OCA using patient-specific OVB-organoids and test if pharmacological agents and gene augmentation strategies can mitigate the disease phenotypes.To this end, via collaborating with human geneticists, we have identified patients carrying mutations in SPATA7, Cep290 (causing LCA), and HPS1 (causing OCA). Notably, these patient mutations are non-syndromic, meaning that the mutations do not affect the brain developmental process but only the retina.This research program combines our interdisciplinary expertise to dissect the deregulated cellular pathways that elicit disease development in patient-specific OVB-organoids and evaluate potential gene-based therapies. To accomplish this ultimate goal, we will1. Generate vascularized OVB-organoids (v-OVB-organoids) for an extended period of viability to generate mature retinal cell types.2. Generate patient-specific v-OVB-organoids to dissect developmental pathophysiology of LCA and OCA due to SPATA7, Cep290, and HPS1 mutations.3. Determine the impact of translational read-through agents and AAV-gene augmentations in mitigating the disease phenotypes. Overall, with our interdisciplinary expertise that uses novel types of 3D brain-retinal hybrid organoids, we will identify deregulated cellular pathways of retinal developmental disorders causing LCA and OCA and offer novel therapeutic options.