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率和死亡率的主要原因 女人。多种系统性风险因素，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，但到目前为止，它还没有 可能将危险因素与共同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 在将不同的风险因素与启动 动脉粥样硬化病变。 这个项目强调的是其中一种转录因子，核因子-kappaB (核因子-kappaB)，其激活与 动脉粥样硬化通过一系列显著的相关性。这些措施包括 观察到活化的内皮细胞核因子-kappaB主要存在于 依赖于核因子-kappaB的内皮基因也存在的动脉粥样硬化病变 选择性表达；动脉粥样硬化是对不同刺激的反应 共同具有产生氧化应激和激活核因子-kappaB的能力 系统；几种抑制病变形成的药物也起抗氧化剂的作用 稳定核因子-kappaB；动脉粥样硬化病变形成于不同的区域 指动脉树的，尤指在分支点或主要弯曲处或其附近 血管内皮细胞的核因子-kappaB系统被选择性地激活。 尽管这些关联具有挑衅性，但没有直接证据 证明核因子-kappaB的激活是必要的或充分的 动脉粥样硬化或定义病变易发区域。这样做的目的是 因此，建议确定内皮细胞核因子-kappaB在 动脉粥样硬化病变的开始。不幸的是，功能丧失 几种核因子-kappaB系统组分的突变在小鼠中具有重要意义 发育异常使其不能用于研究 动脉硬化。在此应用程序中，使用条件鼠标的策略 遗传学的提出是为了避免这种复杂的情况，并检验这一假设 核因子-kappaB系统在早期白血病的形成中起着关键作用。 动脉粥样硬化病变。在第一个特定目的中，LDLR-/-小鼠模型 动脉粥样硬化将被用来确定是否需要表达核因子-kappaB 用于体内早期损伤形成。这些研究利用了Cre-loxP系统 实现核因子-kappaB系统内皮限制性条件性突变 组件。在第二个具体目标中，我们将确定是否存在监管失调 正常抑制核因子-kappaB基因在血管内皮细胞中的表达 激活改变LDLR-/-小鼠的早期损伤形成。这些研究将 利用四环素调控的转基因表达产生小鼠 核因子-kappaB抑制因子的诱导性和内皮限制性表达 激活。在第三个具体目标中，我们将确定核因子-kappaB是否 信号在指定病变易发区域和病变抵抗区域中起作用 对LDLR-/-小鼠的主动脉的影响。总而言之，这些研究应该可以确定 核因子-kappaB系统是启动 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.