Neurovascular functions of a small RNA Snord118-mediated ribosome biogenesis

项目摘要/摘要 神经血管单位(NVU)功能障碍与弥漫性白质障碍相关 血管疾病(SVD)，影响大约50%的痴呆症，包括阿尔茨海默病和 阿尔茨海默病相关痴呆(AD/ADRD)。脊椎病是一组由人类引起的疾病 通过核糖体蛋白或核糖体生物发生因子的突变。普遍核糖体的调节失调 生物发生过程导致组织特异性表型仍然知之甚少。这项提议的目标是 建立两种新的遗传性SVD小鼠模型并用于确定NVU细胞类型(S) 选择性地容易受到无处不在的核糖体生物发生过程的干扰。我们将重点关注 非编码RNA Snord118，编码核糖体生物发生因子。人类SNOD118点突变研究 导致SVD的白质脑病称为脑白质钙化和囊肿病(LCC)，这是第一个纯粹 核糖体病中的神经紊乱。我们收集了以下初步数据：1)生成了两个 独立病变点突变敲入(KI)小鼠模型，表现出患者样的运动和认知 行为异常；2)确定周细胞丢失，以及微血管和白质损伤 Snord118KI小鼠脑，反映血管单位损伤，不造成致命性出血；3) 开发了一种基于PARIS的高通量MAP RNA交联和测序新技术 单分子和全基因组水平的碱基对分辨的结构和RNA-RNA相互作用；4) 使用了paris并在发育早期的小鼠大脑中识别了Snord118靶点。初步数据 这让我们假设，Snord118突变介导的核糖体生物发生中断选择性地影响 NVU细胞通过靶向rRNA和非rRNA导致LCC样表型。为了检验这一假设，有两个例子 提出了具体的目标。目的1将建立小鼠LCC模型，并鉴定NVU细胞(S)是如何 选择性地受到Snord118突变的影响。AIM 2将使用巴黎结合Ki小鼠来识别Snord118 体内靶点并确定Snord118 RNA的结构-功能关系。使用我们的新KI鼠标和最新的 巴黎，这项研究将产生第一个目前还不存在的Snord118 LCC易驯服的小鼠模型， 确定Snord118作用和LCC疾病的机制，揭示以前未知的弱点 特定的NVU细胞破坏了无处不在的核糖体生物发生过程，因此有助于调和 核糖体生物发生的全球性要求下核糖病的神经学表型特异性 在所有的牢房里。

PROJECT SUMMARY / ABSTRACT Dysfunction of neurovascular unit (NVU) contributes to diffuse white matter disorder associated with small- vessel disease (SVD), which affects approximately 50% of all dementia, including Alzheimer's disease and Alzheimer's disease-related dementias (AD/ADRD). Ribosomopathies are a group of human disorders caused by mutations in ribosomal proteins or ribosome biogenesis factors. How dysregulation of a universal ribosome biogenesis process leads to tissue-specific phenotypes remains poorly understood. The goal of this proposal is to develop two new genetic mouse models for SVD and use them to determine how NVU cell type(s) are selectively vulnerable to the disruption of a ubiquitous ribosome biogenesis process. We will focus on noncoding RNA Snord118, which encodes a ribosome biogenesis factor. Snord118 point mutations in humans lead to SVD named leukoencephalopathy with calcifications and cysts (LCC), which represents the first purely neurological disorder in ribosomopathies. We have assembled the following preliminary data: 1) generated two independent disease point mutation knock-in (KI) mouse models, which display patient-like motor and cognitive behavioral abnormalities; 2) identified pericyte loss, and microvascular and white matter injury in these Snord118 KI mouse brains, which reflects the vascular unit impairment without causing lethal hemorrhage; 3) developed a new crosslinking and sequencing based technology named PARIS to high throughput map RNA structures and RNA-RNA interactions at single molecule and genome-wide levels with base-pair resolution; 4) used PARIS and identified Snord118 targets in mouse brains at early developmental stage. Preliminary data led us to hypothesize that Snord118 mutation-mediated disruption of ribosome biogenesis selectively affects NVU cells via targeting rRNAs and non-rRNAs leading to LCC-like phenotypes. To test this hypothesis, two specific aims are proposed. Aim 1 will establish mouse models of LCC and identify how NVU cell(s) are selectively affected by Snord118 mutations. Aim 2 will use PARIS coupled with KI mice to identify Snord118 targets in vivo and determine Snord118 RNA structure-function relationships. Using our new KI mice and latest PARIS, this study will generate the first tractable mouse models that do not currently exist for Snord118 LCC, identify mechanisms of Snord118 action and LCC disease, uncover a previously unknown vulnerability of specific NVU cells to the disruption of a ubiquitous ribosome biogenesis process, therefore help to reconcile the neurological phenotype specificity of ribosomopathies with the global requirement of ribosome biogenesis in all cells.