Profilin-1's Role in Atherosclerosis

项目总结 动脉粥样硬化是世界范围内心血管相关死亡的主要原因。肌动蛋白结合蛋白Profilin-1 肌动蛋白细胞骨架的重要调节因子(PFN1)在临床前期动脉粥样硬化斑块中过表达 模型以及人类疾病方面的研究。通过胚胎杂合敲除(KO)基因降低PFN1的表达 在小鼠的PFN1基因中，促动脉粥样硬化的炎症细胞的血管渗透减少(即 巨噬细胞)和斑块大小，提示PFN1减少 对动脉粥样硬化有部分保护作用。由于动脉粥样硬化是一种涉及到 多种细胞类型(血管内皮细胞、各种免疫细胞、平滑肌细胞)， 以前的研究不能区分PFN1的S在动脉粥样硬化进展过程中来自特定细胞类型的贡献。 此外，缺乏上市的pfn1小分子抑制剂阻碍了靶向的翻译努力。 PFN1作为一种潜在的策略来减缓动脉粥样硬化的发展和/或进展。的目标是 拟议的研究是专门剖析内皮细胞PFN1在动脉粥样硬化中的作用，并进一步探讨 PFN1是一个有效的减轻动脉粥样硬化的药理靶点。为了实现这一目标，一种新的可诱导 血管内皮细胞特异性PFN1 KO小鼠模型及针对PFN1-肌动蛋白的新型小分子研究化合物 将使用交互界面。血管生成和血管通透性促进营养物质的输送和 白细胞侵入，促进动脉粥样硬化形成，斑块生长，最终斑块破裂。我们已经证明了 在生理环境中，内皮细胞PFN1是血管生成的重要介质。我们还发现，PFN1 血管内皮细胞耗竭改善屏障功能，这一发现与pfn1的S加剧激动剂诱导的能力一致。 体内微血管高通透性。因此，我们假设抑制血管内皮细胞PFN1 Function通过减少斑块血管生成和血管通透性发挥动脉粥样硬化保护作用。 Aim 1A将利用一种新的EC特异性的PFN1 KO小鼠来研究PFN1缺陷的动脉粥样硬化进展 老鼠。在Aim 1B中，将利用体外内皮细胞对PFN1表达的扰动来揭示PFN1对 静态和流动分析中白细胞粘附性和外渗性的变化，以及 内皮细胞的收缩能力。AIM 2将筛选出最有效的新型PFN1：肌动蛋白相互作用抑制剂 通过内皮细胞增殖、迁移、生化检测和体内血管生成确定的抑制物 化验。优化的抑制剂将用于载脂蛋白E缺陷小鼠模型，作为一种潜在的治疗 动脉硬化。

PROJECT SUMMARY Atherosclerosis is a major cause of cardiovascular-related death worldwide. Actin-binding protein Profilin-1 (Pfn1), an important regulator of actin cytoskeleton is overexpressed in atherosclerotic plaques in preclinical models as well as in human disease. Global reduction of Pfn1 by embryonic heterozygous knockout (KO) of the Pfn1 gene in mice displays diminished vascular infiltration of pro-atherogenic inflammatory cells (i.e. macrophages) and plaque size in experimentally induced atherosclerosis, suggesting that Pfn1 diminution confers partial protection against atherosclerosis. Since atherosclerosis is a disease that involves pathology of multiple cell types (vascular endothelial cells (VEC), various types of immune cells, smooth muscle cells), previous studies could not discern Pfn1’s contribution from specific cell types in atherosclerosis progression. Furthermore, lack of marketed small molecule inhibitors of Pfn1 has hampered translational efforts of targeting Pfn1 as a potential strategy to mitigate atherosclerosis development and/or progression. The goal of the proposed study is to specifically dissect the role of endothelial Pfn1 in atherosclerosis and further explore whether Pfn1 is an impactful pharmacological target to diminish atherosclerosis. To address this goal, a novel inducible VEC-specific Pfn1 KO mouse model and novel small molecule investigative compounds targeting the Pfn1-actin interaction interface will be used. Angiogenesis and vascular permeability facilitate nutrient delivery and leukocyte invasion, promoting atherogenesis, plaque growth and eventually plaque rupture. We have shown that endothelial Pfn1 is an important mediator of angiogenesis in physiological settings. We also found that Pfn1 depletion in VEC improves barrier function, a finding consistent with Pfn1’s ability to exacerbate agonist-induced microvascular hyper-permeability in vivo. Thus, we hypothesize that inhibition of vascular endothelial Pfn1 function exerts an atheroprotective effect by reducing plaque angiogenesis and vascular permeability. Aim 1A will utilize a novel EC-specific Pfn1 KO mouse to study atherosclerosis progression in Pfn1 deficient mice. In Aim 1B, in vitro endothelial perturbation of Pfn1 expression will be used to reveal the effect of Pfn1 to changes in leukocytic adhesion and extravasation in static and flow-based assays, as well as changes in endothelial contractility. Aim 2 will winnow available novel Pfn1:actin interaction inhibitors to the most effective inhibitor as determined by endothelial proliferation, migration, biochemical assays, and in vivo angiogenesis assays. The optimal inhibitor will be used in ApoE deficient mouse model as a potential therapeutic for atherosclerosis.