RNA-Binding Proteins in the Regulation of Vascular Inflammation and Immunity

炎症旨在摧毁、禁用或遏制致病入侵者，但必须控制为 避免破坏关键的宿主系统，如血管系统。当免疫细胞和细胞之间的相互作用 血管系统出现问题，会导致动脉瘤、动脉粥样硬化等血管病变。 疾病。先天免疫细胞与动脉壁相互作用的实验研究 动脉粥样硬化--一种含有关键炎症成分的无菌慢性损伤过程--已经揭示 对改变炎症细胞外成分的选择性剪接反应的广泛调控 内膜和重新招募的免疫细胞的行为，以保护动脉壁免受损害。指导原则 这些数据和新的体外CRISPR筛选，以探索RNA结合蛋白(RBP)在 调节内皮细胞炎症，我们发现了一组RBP对天然免疫细胞的反应 募集在通过NFkB信号协调内皮细胞激活过程中起关键作用。这里, 我们检验了这样的假设，即其中一个RBP，Eavl1，协调动脉内膜中的选择性剪接 对先天免疫细胞招募的反应，以调节慢性免疫功能(目标1)。在寻求一种 更深入地了解这种免疫调节系统，我们有了意想不到的发现，比如 许多RBP与插入到基因中的转座元件(TE)序列强烈结合，并且它们的 核糖核酸记录(p&lt；0.0001)。虽然大多数TE是不活动的，但这些残留的TE序列约占45% 我们的基因组，几乎在所有基因中都能找到，并能在转录本中提供隐秘的剪接位点，依赖于 RBP活动。因此，我们的目标是定义TE结合RBP家族，以了解它们在 炎症反应及其通过结合对剪接模式和炎症反应的影响 到TE(目标2)。这些目标的完成将为内皮细胞的贡献提供新的见解 慢性炎症状态下对炎症的选择性剪接反应及其作用 普遍存在的TE衍生序列通过结合它们的RBP进行转录调控，提供了新的途径 了解和治疗心血管系统的慢性炎症。

Inflammation is designed to destroy, disable, or contain pathogenic invaders, but must be controlled to avoid destruction of key host systems, like the vasculature. When the interaction between immune cells and the vasculature goes awry, it can contribute to vascular lesions in aneurysm, atherosclerosis, and other diseases. Our study of the interactions between innate immune cells and the arterial wall in models of atherosclerosis – a sterile and chronic injury process with a critical inflammatory component – has revealed broad regulation of alternative splicing responses that change the extracellular composition of the inflamed intima and the behavior of recruited immune cells that protect the arterial wall from damage. Guided by these data and novel in vitro CRISPR screens to probe the function of RNA binding proteins (RBP) in the regulation endothelial inflammation, we have discovered a set of RBP responsive to innate immune cell recruitment that are critical in orchestrating the activation of the endothelium through NFkB signaling. Here, we test the hypothesis that one of these RBP, Elavl1, coordinates alternative splicing in the arterial intima in response to innate immune cell recruitment to regulate chronic immune functions (Aim 1). In seeking a deeper understanding of this immune-regulatory system, we made the unexpected discovery that, like Elavl1, many RBP strongly bind to transposable element (TE) sequences inserted within genes and their RNA transcripts (p<0.0001). While most TE are inactive, these vestigial TE sequences account for ~45% of our genome, are found in nearly all genes, and can provide cryptic splice sites in transcripts that depend on RBP activity. Thus, we aim to define the family of TE-binding RBP, to understand their regulation during inflammatory responses, and their impact on splicing patterns and inflammatory responses through binding to TE (Aim 2). The completion of these aims will provide new insight into the contribution of endothelial alternative splicing responses to inflammation in chronic inflammatory states, and the contribution of pervasive TE-derived sequence to transcript regulation through RBP that bind them, providing new avenues to understand and treat chronic inflammation in the cardiovascular system.