GPCR Kinase-2 in TNFalpha Signaling in Macrophages

巨噬细胞中 TNFα 信号转导中的 GPCR 激酶 2

• 批准号: 7633012
• 负责人: Narayanan Parameswaran
• 金额: $ 37.51万
• 依托单位: MICHIGAN STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-01 至 2011-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7633012
• 关键词: Adrenergic Receptor; Affect; Apolipoprotein E; Apoptosis; Arterial Fatty Streak; Atherosclerosis; Beta-Adrenergic Receptor Kinase 1; Biochemical; Biology; Cells; Chronic; Data; Development; Disease; Endothelial Cells; Foam Cells; Functional disorder; G Protein-Coupled Receptor Genes; Growth Factor; Immune; Inflammation Mediators; Inflammatory; Inflammatory Response; Knockout Mice; Lipoproteins; Low Density Lipoprotein Receptor; Mediating; Myeloid Cells; Pathogenesis; Pathway interactions; Phosphorylation; Phosphotransferases; Play; Production; Protein-Serine-Threonine Kinases; Role; Rupture; Signal Transduction; Smooth Muscle Myocytes; Staging; Testing; Tumor Necrosis Factor-alpha; Tumor Necrosis Factors; atherogenesis; chemokine; cytokine; inhibitor/antagonist; insight; macrophage; monocyte; new therapeutic target; novel; public health relevance; therapeutic target; uptake

Macrophages are important immune cells involved in the pathogenesis of many inflammatory diseases, including atherosclerosis and are one of the major immune cells in the atherosclerotic lesions. In addition to becoming foam cells upon uptake of modified lipoproteins in the vessel walls, macrophages also mediate the inflammatory responses that are associated with atherosclerotic plaque formation by producing cytokines, chemokines and growth factors. These agents further influence chemoattraction of more monocytes and other immune cells as well as profoundly affect the functions of smooth muscle cells and endothelial cells that are in the vicinity. Therefore, macrophages play an essential role in all stages of atherogenesis including fatty streaks to advanced plaques and eventually to plaque rupture. Thus, understanding the biochemical mechanisms by which macrophage biology is regulated is highly critical. Preliminary data demonstrates that macrophage biology is regulated by G-protein coupled receptor kinase-2 (GRK2). GRK2 is a serine/threonine kinase that was discovered for its role in the phosphorylation of 􀀂-adrenergic receptors. Evidence indicates that tumor necrosis factor-􀀁(TNF􀀁)-induced NF􀀃B signaling, and the consequent macrophage biology are critically regulated by GRK2, via interaction with, and potentially phosphorylation of the inhibitor of NF􀀃B signaling namely I􀀃B􀀁. These results suggest a novel and significant role for this kinase in macrophage biology and therefore in the pathogenesis of atherosclerosis. The objective of this proposal is to further expand on our preliminary findings and examine the mechanisms by which GRK2 regulates macrophage biology and importantly, also test if, loss of GRK2 affects the pathophysiology of atherosclerosis. The overall hypothesis is that GRK2 interaction with and phosphorylation of I􀀃B􀀁regulates TNF􀀁-induced NF􀀃B signaling, inflammatory mediator production, and macrophage survival/apoptosis and therefore, GRK2 plays a crucial role in the pathogenesis of atherosclerosis. To test this hypothesis we will examine the following specific aims: 1. Describe the mechanisms by which GRK-2 regulates TNF􀀁-induced NF􀀃B pathway in macrophages. 2. Examine the functional relevance of GRK2 in TNF􀀁signaling in macrophages. 3. Determine whether myeloid cell-specific loss of GRK2 affects the pathogenesis of atherosclerosis in LDLR knockout mice. Taken together, our studies should provide important mechanistic insight into TNF􀀁signaling in macrophages as well as identify potential therapeutic targets in the treatment of chronic inflammatory diseases

巨噬细胞是重要的免疫细胞，参与许多炎症性疾病的发病机制， 包括动脉粥样硬化，是动脉粥样硬化病变中的主要免疫细胞之一。此外 巨噬细胞在吸收血管壁中的修饰脂蛋白后变成泡沫细胞，还介导 通过产生细胞因子与动脉粥样硬化斑块形成相关的炎症反应， 趋化因子和生长因子。这些药物进一步影响更多单核细胞和其他细胞的化学吸引 免疫细胞以及深刻影响平滑肌细胞和内皮细胞的功能 附近。因此，巨噬细胞在动脉粥样硬化形成的所有阶段（包括脂肪纹）中发挥着重要作用 导致斑块进展并最终导致斑块破裂。因此，通过以下方式了解生化机制 哪种巨噬细胞生物学受到调节是非常关键的。初步数据表明巨噬细胞 生物学受 G 蛋白偶联受体激酶 2 (GRK2) 调节。 GRK2 是一种丝氨酸/苏氨酸激酶， 因其在α-肾上腺素能受体磷酸化中的作用而被发现。有证据表明肿瘤 坏死因子 (TNF) 诱导的 NF B 信号传导以及随之而来的巨噬细胞生物学至关重要 受 GRK2 调节，通过与 NF·B 信号传导抑制剂相互作用并对其进行潜在磷酸化 即I·B·。这些结果表明该激酶在巨噬细胞生物学和 因此在动脉粥样硬化的发病机制中。该提案的目的是进一步扩展我们的 初步发现并检查 GRK2 调节巨噬细胞生物学的机制 重要的是，还要测试 GRK2 的缺失是否会影响动脉粥样硬化的病理生理学。总体假设是 GRK2 与 I·B·B 的相互作用和 I·B·B 的磷酸化调节 TNF·诱导的 NF·B 信号传导， 炎症介质的产生和巨噬细胞的存活/凋亡，因此，GRK2 发挥着重要作用 在动脉粥样硬化的发病机制中起着至关重要的作用。为了检验这个假设，我们将检查以下内容 具体目标： 1. 描述 GRK-2 调节 TNF 诱导的 NF B 通路的机制 巨噬细胞。 2. 检查 GRK2 在巨噬细胞 TNF 信号传导中的功能相关性。 3. 确定 骨髓细胞特异性 GRK2 缺失是否影响 LDLR 敲除小鼠动脉粥样硬化的发病机制。 总而言之，我们的研究应该为巨噬细胞中 TNF 信号转导提供重要的机制见解 以及确定治疗慢性炎症性疾病的潜在治疗靶点