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: 8496097
• 负责人: Narayanan Parameswaran
• 金额: $ 35.15万
• 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 2015-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8496097
• 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; GRK; Growth Factor; Immune; Inflammation Mediators; Inflammatory; Inflammatory Response; Knockout Mice; Lipoproteins; Mediating; Pathogenesis; Pathway interactions; Phosphorylation; Phosphotransferases; Play; Production; Protein-Serine-Threonine Kinases; Role; Rupture; Signal Transduction; Smooth Muscle Myocytes; Staging; Testing; Tumor Necrosis Factor-alpha; atherogenesis; chemokine; cytokine; inhibitor/antagonist; insight; macrophage; monocyte; new therapeutic target; novel; public health relevance; therapeutic target; uptake

DESCRIPTION (provided by applicant): 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 (including inflammatory mediator production, and macrophage apoptosis/survival) is regulated is highly critical. Preliminary data demonstrates that macrophage biology is regulated by a serine/threonine kinase, namely, G-protein coupled receptor kinase-2 (GRK2). GRK2 was originally discovered for its role in the phosphorylation of -adrenergic receptor and other GPCRs. Recent studies indicate that there are other cytosolic targets of GRK2. However, the role of GRK2 in macrophages, particularly as it relates to non-GPCRs and cytosolic targets is not well known. Preliminary data demonstrates that tumor necrosis factor- (TNF)-induced NFB signaling, and the consequent inflammatory mediator expression and survival of macrophages are critically regulated by GRK2. Preliminary findings also suggest that GRK2 mediates its effects on NFB signaling via interaction with, and potentially phosphorylation of the inhibitor of NFB signaling namely IB. 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 IB regulates TNF-induced NFB signaling, inflammatory mediator production, and macrophage survival/apoptosis and therefore, plays a crucial role in the pathogenesis of atherosclerosis. To test this hypothesis we will examine the following specific aims: 1. Determine the mechanisms by which GRK-2 regulates TNF-induced NFB pathway in macrophages. 2. Examine the functional relevance of GRK2 in TNF signaling in macrophages. 3. Determine whether loss of GRK2 affects the pathogenesis of atherosclerosis in Apo-E knockout mice. Taken together, our studies should provide important insight into the mechanisms of TNF signaling in macrophages as well as identify potential therapeutic targets in the treatment of chronic inflammatory diseases.

描述（由申请人提供）：巨噬细胞是参与许多炎性疾病（包括动脉粥样硬化）发病机制的重要免疫细胞，并且是动脉粥样硬化病变中的主要免疫细胞之一。除了在血管壁中摄取修饰的脂蛋白后成为泡沫细胞之外，巨噬细胞还通过产生细胞因子、趋化因子和生长因子介导与动脉粥样硬化斑块形成相关的炎症反应。这些药物进一步影响更多单核细胞和其他免疫细胞的化学吸引，并深刻影响附近平滑肌细胞和内皮细胞的功能。因此，巨噬细胞在动脉粥样硬化形成的所有阶段都起着至关重要的作用，包括脂肪条纹到晚期斑块和最终斑块破裂。因此，了解巨噬细胞生物学（包括炎症介质产生和巨噬细胞凋亡/存活）调节的生化机制是非常关键的。初步数据表明，巨噬细胞生物学是由丝氨酸/苏氨酸激酶，即G蛋白偶联受体激酶-2（GRK 2）调节的。GRK 2最初是由于其在β-肾上腺素能受体和其他GPCR的磷酸化中的作用而被发现的。最近的研究表明GRK 2还有其他的胞质靶点。然而，GRK 2在巨噬细胞中的作用，特别是当它涉及非GPCR和胞质靶标时，还不是众所周知的。初步数据表明，肿瘤坏死因子（TNF）诱导的NFB信号传导，以及随之而来的炎症介质的表达和巨噬细胞的存活受到GRK 2的严格调节。初步研究结果还表明，GRK 2通过与NFB信号传导抑制剂即IB的相互作用和潜在磷酸化来介导其对NFB信号传导的影响。这些结果表明，这种激酶在巨噬细胞生物学中的一个新的和重要的作用，因此在动脉粥样硬化的发病机制。本提案的目的是进一步扩展我们的初步发现，并检查GRK 2调节巨噬细胞生物学的机制，重要的是，还测试GRK 2的丢失是否影响动脉粥样硬化的病理生理学。总体假设是GRK 2与IB的相互作用和IB的磷酸化调节TNF诱导的NFB信号传导、炎症介质产生和巨噬细胞存活/凋亡，因此在动脉粥样硬化的发病机制中起关键作用。为了检验这一假设，我们将研究以下具体目标：1。确定GRK-2调节巨噬细胞中TNF诱导的NFB途径的机制。2.检查GRK 2在巨噬细胞中的TNF信号传导中的功能相关性。3.确定GRK 2的缺失是否影响Apo-E基因敲除小鼠动脉粥样硬化的发病机制。总之，我们的研究应该提供重要的洞察TNF信号在巨噬细胞中的机制，以及确定潜在的治疗靶点在慢性炎症性疾病的治疗。