Contributions of Endothelial RNA-binding Protein Dysregulation to Blood Brain Barrier Defects and Neurodegenerative Disease

剪接失调是由包括TDP-43在内的RNA结合剪接因子的缺陷引起的 被认为是神经元功能障碍和认知功能下降的标志和潜在驱动因素 阿尔茨海默氏症(AD)和相关痴呆(ADRD)。尽管大量证据表明 剪接功能障碍的遗传原因并不局限于神经细胞，剪接缺陷 AD和ADRD患者的血脑屏障内皮细胞尚未检测到。血脑屏障中的缺陷随着 年龄和AD和ADRD进展的早期，它们对疾病有贡献 进步。通过体内信息学和体外CRISPR筛选，我们鉴定了TDP-43 和其他几个AD和ADRD相关的剪接因子作为转录后调控因子 对内皮细胞进行剪接，以应对无菌炎症。使用一种新的方法分离 从冻存的人脑组织中提取内皮细胞核，我们发现核TDP减少。 血脑屏障内皮细胞43水平与增龄及AD、ADRD的关系 病人。此外，在一个新的小鼠模型中，我们发现TDP-43从 脑内皮细胞导致血脑屏障渗漏，激活微血管系统和 小胶质细胞。在这里，我们假设内皮细胞中核TDP-43的丢失 导致血脑屏障和微血管系统的缺陷，并通过影响 维持静止的内皮细胞所需的前-信使核糖核酸的剪接。我们建议 检测人AD和ADRD血管内皮细胞TDP-43的表达和剪接活性 以及核TDP-43缺失对阿尔茨海默病模型小鼠疾病进展的影响 ADRD额颞叶痴呆(FTLD)。此外，由于我们的新技术将 让我们对AD和ADRD的内皮有一个前所未有的看法，我们建议延长我们的 研究TDP-43以广泛检测这些疾病中内皮细胞的剪接变化 并使用我们建立的生物信息学和体外筛选方法来确定 其他内皮剪接因子的缺陷是否也会导致血脑屏障功能障碍。这个 这项工作的完成将对转录后基因的贡献提供新的见解 RNA结合蛋白对血脑屏障缺陷、微血管功能障碍的调节作用 AD和ADRD的进展。

Splicing dysregulation, caused by defects in RNA-binding splice factors including TDP-43, is considered a hallmark and potential driver of neuronal dysfunction and cognitive decline in Alzheimer’s (AD) and Related Dementia (ADRD). Although substantial evidence suggests that genetic causes of splicing dysfunction are not limited to neuronal cells, splicing defects in the BBB endothelium in AD and ADRD have not been examined. Defects in the BBB increase with age and early in the progression of AD and ADRD, where they contribute to disease progression. Through in vivo informatics and in vitro CRISPR screening, we identified TDP-43 and several other AD and ADRD associated splice factors as regulators of post-transcriptional splicing in the endothelium in response to sterile inflammation. Using a novel method to isolate endothelial nuclei from frozen banked human brain tissues, we identified reduced nuclear TDP- 43 levels in endothelial cells of the blood brain barrier (BBB) with age and in AD and ADRD patients. Furthermore, in a novel mouse model, we show that specific deletion of TDP-43 from the brain endothelium leads to leak across the BBB, and activation of the microvasculature and microglial cells. Here, we hypothesize that loss of nuclear TDP-43 in the endothelium contributes to defects in the BBB and microvasculature, and to AD and ADRD by affecting the splicing of pre-mRNA required for the maintenance of a quiescent endothelium. We propose to examine TDP-43 expression and splicing activity in the endothelium in human AD and ADRD, and the effect of loss of nuclear TDP-43 on disease progression in mouse models of AD and the ADRD Frontal temporal lobe dementia (FTLD). Furthermore, since our novel techniques will allow us an unprecedented view of the endothelium in AD and ADRD, we propose to extend our work on TDP-43 to broadly examine splicing alterations in the endothelium in these disease states, and use our established bioinformatics and in vitro screening approaches to determine whether defects in other endothelial splice factors also contribute to BBB dysfunction. The completion of this work will provide new insight into the contributions of post-transcriptional regulation by RNA-binding proteins to BBB defects, microvascular dysfunction and the progression of AD and ADRD.