CD14, Surfactant Proteins, and Vascular Inflammation

该项目的中心假设是血管壁内皮细胞和平滑肌细胞(SMC)是 调节炎症信号的复杂和高度调节的先天免疫系统的一部分 动脉硬化。我们发现人冠状动脉SMC(HCASMC)表达膜结合 CD14，一种模式识别受体，在转导天然免疫中发挥核心作用 炎症细胞对内毒素和其他细菌产物的反应。我们还检测到 表面活性蛋白D(SP-D)在血管细胞中的表达 它与内毒素和CD14结合，调节肺部的先天免疫反应。使用组合 在药理学、分子和基于基因的方法中，我们建议：1.检验假设 SMC中的CD14在多种炎症介质的免疫应答中起着核心作用。我们 我们将确定HCASMC中的CD14配体，并将检测HCASMC中CD14表达的调节 氧化应激和PPAR-γ激活对人冠状动脉内皮细胞的影响我们还将 确定CD14连接是否调节SMC清道夫受体的表达和功能。2L 验证SP-D调节CD14介导的血管细胞促炎信号的假设。 我们建议研究SP-D阻断血管细胞促炎信号的机制。 重点研究SP-D与内毒素和细胞信号蛋白结合的作用。我们还将确定 SP-D的表达是否受炎症介质和/或氧化应激的调节。3.测试 CD14和SP-D调控apoE-/-小鼠动脉粥样硬化的假说。使用CD14-/-和SP-DV-/-小鼠 与apoE-/-小鼠杂交，创造双基因敲除小鼠，我们将检查 动脉粥样硬化、血管炎症和内皮功能障碍 反复挑战低水平的内毒素以刺激天然免疫系统。总而言之，建议的 研究将为CD14在血管炎症中的潜在关键作用提供新的见解，以及 氧化应激和PPAR-γ对血管壁CD14表达的调节此外，建议的 这将是第一次研究SP-D在血管壁中的潜在免疫调节作用。 这些研究将有助于阐明血管壁细胞促进炎症的机制。 现在已知是动脉粥样硬化的重要原因。此外，我们的发现可能会导致新的 动脉粥样硬化的炎性成分的治疗方法。

The central hypothesis of this project is that vascular wall endothelial and smooth muscle cells (SMC) are part of a complex and highly regulated innate immune system that modulates inflammatory signaling in atherosclerosis. We have discovered that human coronary artery SMC (HCASMC) express membranebound CD14, a pattern recognition receptor that plays a central role in transducing innate immune responses to endotoxin and other bacterial products in inflammatory cells. We have also detected expression in vascular cells of surfactant protein D (SP-D), a member of the collectin family of proteins that binds to endotoxin and CD14 to modulate innate immune responses in the lung. Using a combination of pharmacological, molecular, and gene-based approaches, we propose to: 1. Test the hypothesis that CD14 in SMC plays a central role in transducing immune responses to multiple inflammatory mediators. We will identify CD14 ligands in HCASMC, and we will examine regulation of CD14 expression in HCASMC and human coronary artery endothelial cells by oxidative stress and activation of PPAR-gamma. We will also determine whether CD14 ligation modulates expression and function of scavenger receptors in SMC. 2L Test the hypothesis that SP-D modulates CD14-mediated pro-inflammatory signaling in vascular cells. We propose to examine mechanisms whereby SP-D blocks pro-inflammatory signaling in vascular cells, focusing on the role of binding of SP-D to endotoxin and cell signaling proteins. We will also determine whether SP-D expression is regulated by inflammatory mediators and/or oxidative stress. 3. Test the hypothesis that CD14 and SP-D modulate atherosclerosis in apoE-/- mice. Using CD14-/- and SP-DV-/- mice cross-bred with apoE-/- mice to create double knockout mice, we will examine the extent of atherosclerosis, vascular inflammation, and endothelial dysfunction in the absence and presence of recurrent challenges with low-level endotoxin to stimulate the innate immune system. Together, the proposed studies will provide novel insight into the potentially critical role of CD14 in vascular inflammation, and modulation of CD14 expression in the vascular wall by oxidant stress and PPAR-gamma. Further, the proposed studies will be the first to investigate the potential immunomodulatory role of SP-D in the vascular wall. These studies will help to elucidate mechanisms whereby vascular wall cells contribute to inflammation now known to be an important cause of atherosclerosis. Further, our findings may lead to new approaches to treating the inflammatory component of atherosclerosis.