KLF2 as a regulator of endothelial cell biology

KLF2 作为内皮细胞生物学的调节剂

• 批准号: 6925410
• 负责人: MUKESH Kumar JAIN
• 金额: $ 42.52万
• 依托单位: BRIGHAM AND WOMEN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-08-01 至 2006-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6925410
• 关键词: RNA interference; biomechanics; body fluid osmolarity; cAMP response element binding protein; cell adhesion molecules; cell biology; enzyme induction /repression; fluid flow; gel mobility shift assay; gene expression; genetically modified animals; immunocytochemistry; inflammation; interleukin 1; laboratory mouse; microarray technology; nitric oxide synthase; transcription factor; vascular endothelium; vasomotion; yeast two hybrid system

DESCRIPTION (provided by applicant): The vascular endothelium is a critical regulator of vascular function. Accumulating clinical and experimental studies strongly support the hypothesis that atherosclerosis is a chronic inflammatory disease state. Exposure to inflammatory cytokines results in the expression and/or elaboration of factors, which allow for immune cell recruitment and adhesion to the blood vessel wall. However, despite this systemic inflammatory state, the lesions of atherosclerosis show a non-random pattern of distribution such as branch points and areas of major curvature. These observations have led to the hypothesis that local events such as fluid mechanical forces can affect endothelial function. Indeed, experimental studies demonstrate that uniform laminar flow confers anti-proliferative, anti-thrombotic, anti-adhesive, and anti-oxidant properties to the endothelium. To obtain a greater understanding of how inflammatory stimuli and fluid forces impact on endothelial cell biology, we undertook a genomic profiling approach to assess global patterns of gene expression. These studies identified the transcription factor KLF2 as being induced by laminar shear stress and inhibited by the inflammatory cytokine IL-lbeta. Over expression of KLF2 in endothelial cells robustly induced the expression and activity of endothelial nitric oxide synthase - a central regulator of vascular homeostasis. In addition, KLF2 potently inhibits the induction of endothelial adhesion molecules such as VCAM-1 and E-selectin in response to diverse inflammatory stimuli. Consistent with these observations, in vitro flow assays demonstrate that immune cell attachment and rolling to an endothelial monolayer is markedly attenuated. Finally, our studies implicate recruitment of the transcriptional coactivator cyclic AMP response element-binding protein (CBP/p300) as a unifying mechanism for these distinct effects of KLF2. These observations support an important role for KLF2 as a "molecular switch" which regulates endothelial function. In AIM 1 and 2 of this proposal studies will be undertaken to understand the molecular basis for KLF2 ability to both induce eNOS and inhibit the cytokine- mediated induction of adhesion molecules. In AIM 3 we will overexpress, in an endothelial specific manner, KLF2 in vivo and assess for effects on vascular inflammation and vasoreactivity. These studies will provide a detailed understanding of KLF2 role in endothelial cell biology in health and disease states.

描述（由申请人提供）：血管内皮是血管功能的关键调节因子。累积的临床和实验研究强烈支持动脉粥样硬化是一种慢性炎症性疾病状态的假设。暴露于炎性细胞因子导致因子的表达和/或加工，其允许免疫细胞募集和粘附到血管壁。然而，尽管存在这种全身炎症状态，动脉粥样硬化病变显示出非随机分布模式，例如分支点和大弯区域。这些观察结果导致了局部事件如流体机械力可以影响内皮功能的假设。事实上，实验研究表明，均匀层流赋予内皮抗增殖、抗血栓形成、抗粘附和抗氧化特性。为了更好地了解炎症刺激和流体力如何影响内皮细胞生物学，我们采用基因组分析方法来评估基因表达的全球模式。这些研究鉴定了转录因子KLF 2被层流剪切应力诱导并被炎性细胞因子IL-1 β抑制。KLF 2在内皮细胞中的过度表达强烈地诱导内皮型一氧化氮合酶的表达和活性，内皮型一氧化氮合酶是血管稳态的中心调节因子。此外，KLF 2还能有效抑制内皮细胞粘附分子（如VCAM-1和E-选择素）对多种炎症刺激的反应。与这些观察结果一致，体外流动试验表明，免疫细胞附着和滚动到内皮单层显着减弱。最后，我们的研究表明，转录辅激活因子环磷酸腺苷反应元件结合蛋白（CBP/p300）的招募是KLF 2这些不同作用的统一机制。这些观察结果支持KLF 2作为调节内皮功能的“分子开关”的重要作用。在本提案的AIM 1和2中，将进行研究以了解KLF 2诱导eNOS和抑制细胞因子介导的粘附分子诱导的能力的分子基础。在AIM 3中，我们将以内皮特异性方式在体内过表达KLF 2，并评估其对血管炎症和血管反应性的影响。这些研究将详细了解KLF 2在健康和疾病状态下内皮细胞生物学中的作用。