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

炎症的目的是破坏，禁用，或包含致病性入侵者，但必须加以控制， 避免破坏关键的宿主系统，如脉管系统。当免疫细胞和 当脉管系统出错时，它可以导致动脉瘤、动脉粥样硬化和其他疾病中的血管病变。 疾病我们研究了先天性免疫细胞和动脉壁之间的相互作用， 动脉粥样硬化是一种无菌的慢性损伤过程，具有重要的炎症成分， 选择性剪接反应的广泛调节改变了炎症细胞的细胞外组成， 内膜和保护动脉壁免受损伤的募集免疫细胞的行为。指导 这些数据和新的体外CRISPR筛选，以探测RNA结合蛋白（RBP）在细胞中的功能， 通过调节内皮炎症，我们发现了一组对先天性免疫细胞应答的RBP， 在通过NFkB信号传导协调内皮活化中至关重要的细胞募集。在这里， 我们检验了这样的假设：其中一种RBP（Elavl 1）在动脉内膜中协调选择性剪接， 应答先天免疫细胞募集以调节慢性免疫功能（目的1）。积极推动 更深入地了解这种免疫调节系统，我们意外地发现， Elavl 1，许多RBP强烈结合插入基因内的转座因子（TE）序列，并且它们的 RNA转录物（p<0.0001）。虽然大多数TE是无活性的，但这些残留的TE序列占约45%。 我们的基因组，几乎在所有的基因中都能找到，并且可以在转录本中提供隐蔽的剪接位点， RBP活性。因此，我们的目标是定义TE结合RBP家族，以了解它们在细胞周期中的调控。 炎症反应，以及它们通过结合对剪接模式和炎症反应的影响 目标2（Aim 2）这些目标的完成将为内皮细胞在肿瘤发生中的作用提供新的见解。 慢性炎症状态下对炎症的选择性剪接反应，以及 广泛的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.