Investigating the pathogenesis of Moyamoya Disease using patient derived induced pluripotent stem cells

项目摘要 烟雾病（MMD）是一种罕见的慢性脑血管疾病，影响大脑血管， 导致主要脑动脉阻塞和附近脆弱血管的形成。临床表现 MMD的主要症状是短暂性脑缺血发作和脑梗死，常导致缺血性或出血性卒中。 侵入性血运重建手术是目前唯一可用的治疗方法。可能是遗传因素， 循环和环境因素参与了MMD的发病过程，但其分子机制尚不清楚， 潜在的MMD在很大程度上是未知的，主要是由于缺乏确定的MMD特异性细胞或动物模型。 模型在这项提议中，我们的目标是通过使用MMD患者来源的iPSC来了解MMD的发病机制。 细胞模型结合功能测定和高通量测序方法。 MMD的主要组织病理学发现是血管最内层的纤维细胞增厚 （内膜），其导致血管的狭窄和闭塞。这很可能是由于扩散的增加。 血管平滑肌细胞（VSMC）或内皮细胞（EC）和细胞外基质组分。线索 可能导致VSMCs转变为增殖性表型，并从培养基迁移到 内膜，从而导致内膜增厚。因此，我们假设失调的信号传导 血管平滑肌细胞和内皮细胞之间的相互作用驱动了MMD病理学。使用MMD患者iPSC衍生的EC和VSMC，我们获得了 通过构建血管类器官，建立了共培养模型和三维细胞模型。初步共培养 数据显示，与健康对照相比，MMD EC和VSMC功能受损， 在细胞增殖和体外血管生成管稳定方面。在目标1中，我们的目标是描述 MMD iPSC衍生的EC和VSMC在共培养物中的功能特性，通过评估它们在细胞内的能力， 在正常和缺氧条件下的增殖、迁移和管形成。VSMC表型转换将是 使用特异性表型标记和收缩性测定进行检查。我们还将描述血管结构 使用我们建立的由MMD iPSC产生的血管类器官的特征。在目标2中，我们将使用RNA 测序技术研究VSMC和EC的转录组，并鉴定潜在的分子 介导MMD。将使用定量PCR及其表达模式验证最佳靶标 将在我们的细胞模型中使用免疫染色进行研究。我们的研究将阐明细胞类型特异性因子 可能导致MMD的病理变化MMD的血管类器官可能是一种有效的人MMD体外模型 并提供关于MMD机制的宝贵信息。我们的研究数据将推动知识的发展， MMD发病机制，并开辟新的研究途径，以产生临床相关的药物为基础的方法， 治疗MMD。

PROJECT SUMMARY Moyamoya Disease (MMD) is a rare, chronic cerebrovascular disease that affects the blood vessels of the brain, causing occlusion of major cerebral arteries and formation of fragile vessels in the vicinity. Clinical manifestations of MMD are transient ischemic attacks and cerebral infarctions, often leading to ischemic or hemorrhagic stroke. Invasive revascularization surgery is the only current treatment available. There may be a combination of genetic, circulating and environmental factors involved in the pathogenesis of MMD, however, the molecular mechanisms underlying MMD is largely unknown, mainly due to the lack of established MMD-specific cellular or animal models. In this proposal we aim to understand the pathogenesis of MMD by using MMD patient- derived iPSCs cellular models in combination with functional assays and high throughput sequencing approaches. The main histopathological finding in MMD is the fibro-cellular thickening of the innermost layer of the vessel (intima) which causes narrowing and occlusion of the vessel. This is likely due to an increase in proliferating vascular smooth muscle cells (VSMCs) or endothelial cells (ECs) and extracellular matrix components. Cues from ECs could cause VSMCs to switch to a phenotype that is proliferative and migrates from media to the intima, thus contributing to the thickening of the intima. Thus, we hypothesize that dysregulated signaling between VSMCs and ECs drive MMD pathology. Using MMD patient iPSC-derived ECs and VSMCs, we have established co-culture model and 3D cellular model by generating vascular organoids. Preliminary co-culture data show that both MMD ECs and VSMCs are functionally impaired when compared to healthy controls, with respect to cell proliferation and in vitro angiogenic tube stabilization. In Aim 1, we aim to characterize the functional properties of MMD iPSC-derived ECs and VSMCs in co-cultures by assessing their ability in cell proliferation, migration and tube formation in normal and hypoxic conditions. VSMC phenotype switching will be examined using specific phenotypic markers and contractility assay. We will also characterize vessel structural characteristics using our established vascular organoids generated from MMD iPSCs. In Aim 2, we will use RNA sequencing technology to investigate the transcriptome of VSMCs and ECs and identify potential molecular mediators involved in MMD. Top targets will be validated using quantitative PCR and their expression pattern will be investigated in our cellular models using immunostaining. Our study will elucidate cell-type specific factors that may drive MMD pathology. Vascular organoids from MMD may be an efficient human in vitro MMD model and provide invaluable information on MMD mechanisms. Data from our studies will advance the knowledge in MMD pathogenesis and open up new avenues of research to yield clinically relevant drug-based methods to treat MMD.