NUCLEAR FACTOR KAPPA BETA AND INITIATION OF THE ATHEROSC

描述（由申请人提供）： 动脉粥样硬化是男性和女性发病和死亡的主要原因 妇女。多种系统性危险因素，包括高血压、糖尿病 糖尿病、吸烟和脂蛋白紊乱参与了发病机制 这种慢性动脉炎症性疾病的研究，但迄今为止，尚未得到证实 可能将危险因素与常见的致病机制联系起来。 最近的证据表明一小群转录因子可能是 将不同的风险因素与启动风险因素联系起来至关重要 动脉粥样硬化病变。 该项目强调其中一种转录因子，核因子-kappaB (NF-kappaB)，其激活与 动脉粥样硬化通过一系列显着的相关性。这些包括 观察发现激活的内皮 NF-κB 主要存在于 动脉粥样硬化病变，其中 NF-κB 依赖性内皮基因也 有选择地表达；动脉粥样硬化是对不同刺激的反应而发生的 具有产生氧化应激和激活 NF-kappaB 的能力 系统；多种抑制病变形成的药物也可作为抗氧化剂 并稳定 NF-κB 和；动脉粥样硬化病变在不同区域形成 动脉树，特别是在分支点或大曲率处或附近 其中内皮 NF-κB 系统被选择性激活。 尽管这些相关性具有启发性，但没有直接证据 证明 NF-kappaB 激活是必要或充分的 动脉粥样硬化或用于确定易发生病变的区域。此举的目标 因此，建议确定内皮 NF-κB 在 动脉粥样硬化病变的开始。不幸的是，功能丧失 小鼠中几种 NF-κB 系统组件的突变体表现出显着的 发育异常，妨碍其用于研究 动脉粥样硬化。在此应用中，使用条件鼠标的策略 遗传学被提出来避免这种并发症并检验以下假设： NF-kappaB系统在早期细胞的形成中起着关键作用 动脉粥样硬化病变。在第一个具体目标中，LDLR-/- 小鼠模型 动脉粥样硬化将用于确定是否需要 NF-kappaB 表达 用于体内早期病变形成。这些研究利用 Cre-loxP 系统 实现NF-kappaB系统的内皮限制性条件突变 组件。在第二个具体目标中，我们将确定是否失调 通常抑制 NF-κB 的基因在内皮中表达 激活改变了 LDLR-/- 小鼠的早期病变形成。这些研究将 使用四环素调节的转基因表达来产生具有 NF-κB 抑制剂的诱导型和内皮限制性表达 激活。在第三个具体目标中，我们将确定 NF-kappaB 是否 信号传导在指定易损伤区域和抗损伤区域中发挥作用 LDLR-/- 小鼠的主动脉。综合这些研究应该确定是否 NF-kappaB系统对于启动是必要的和/或充分的 动脉粥样硬化病变。

DESCRIPTION (provided by the applicant): Atherosclerosis is a major cause of morbidity and mortality among both men and women. Multiple systemic risk factors, including hypertension, diabetes mellitus, smoking, and 1ipoprotein disorders are involved in the pathogenesis of this chronic inflammatory disease of arteries, but to date, it has not been possible to associate the risk factors with common pathogenic mechanism. Recent evidence suggests that a small group of transcription factors may be critical in linking the diverse risk factors to the initiation of the atherosclerotic lesion. This project emphasizes one of these transcription factors, nuclear factor-kappaB (NF-kappaB), whose activation has been linked to the onset of atherosclerosis through a remarkable series of correlations. These include observations that activated endothelial NF-kappaB is found predominately in atherosclerotic lesions where NF-kappaB-dependent endothelial genes are also selectively expressed; atherosclerosis develops in response to diverse stimuli that share the ability to create oxidant stress and activate the NF-kappaB system; several agents inhibiting lesion formation also act as antioxidants and stabilize NF-kappaB and; atherosclerotic lesions form at distinct regions of the arterial tree, especially at or near branch points or major curvatures where the endothelial NF-kappaB system is selectively activated. Although these correlations are provocative, there is no direct evidence demonstrating that NF-kappaB activation is necessary or sufficient for atherosclerosis or for defining lesion-prone regions. The goal of this proposal, therefore, is to determine the role of endothelial NF-kappaB in initiation of the atherosclerotic lesion. Unfortunately, loss of function mutants of several NF-kappaB system components in mice present significant developmental abnormalities precluding their use for studies of atherosclerosis. In this application, strategies using conditional mouse genetics are proposed to avoid this complication and test the hypothesis that the NF-kappaB system plays a key role in the formation of the early atherosclerotic lesion. In the First Specific Aim, the LDLR-/- mouse model of atherosclerosis will be used to determine if NF-kappaB expression is required for early lesion formation in vivo. These studies utilize the Cre-loxP system to achieve endothelial -restricted conditional mutation of NF-kappaB system components. In the Second Specific Aim, we will determine if dysregulated expression in endothelium of a gene that normally inhibits NF-kappaB activation alters early lesion formation in LDLR-/- mice. These studies will use tetracycline-regulated transgene expression to generate mice with inducible and endothelial-restricted expression of an inhibitor of NF-kappaB activation. In the Third Specific Aim, we will determine if NF-kappaB signaling plays a role in specifying lesion prone and lesion resistant regions of aorta in LDLR-/- mice. Taken together these studies should determine if the NF-kappaB system is necessary and/or sufficient for the initiation of the atherosclerotic lesion.