Glucocorticoid-regulated transcription networks in macrophage biology

巨噬细胞生物学中糖皮质激素调节的转录网络

• 批准号: 8819540
• 负责人: INEZ ROGATSKY
• 金额: $ 47.26万
• 依托单位: HOSPITAL FOR SPECIAL SURGERY
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-04-01 至 2019-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8819540
• 关键词: Adipocytes; Adipose tissue; Adverse effects; Affect; Anti-Inflammatory Agents; Anti-inflammatory; Antibodies; Attenuated; Binding Sites; Biochemical; Biological; Biological Assay; Biology; CDK9 Protein Kinase; Chronic; Clinic; Code; Comorbidity; Complex; Cost Measures; Data; Disease; Effectiveness; Embryo; Epidemic; Equilibrium; Family; Fibroblasts; Gene Expression; Gene Expression Profile; Gene Expression Regulation; Gene Targeting; Genes; Genetic Transcription; Genomics; Glucocorticoid Receptor; Glucocorticoids; Goals; Health; Homeostasis; Hormones; IRF3 gene; Immune system; In Vitro; Individual; Inflammation; Inflammatory; Insulin Resistance; Interferon Type I; Knockout Mice; Ligand Binding; Ligands; Mediating; Mediator of activation protein; Metabolic; Metabolic Control; Metabolic Diseases; Metabolic syndrome; Metabolism; Modeling; Mus; Natural Immunity; Non-Insulin-Dependent Diabetes Mellitus; Nuclear Receptors; Null Lymphocytes; Obesity; Pathogenesis; Pathway interactions; Pharmaceutical Preparations; Phenotype; Phosphorylation; Phosphotransferases; Play; Production; Property; Protein Isoforms; Proteins; Public Health; Recruitment Activity; Regulation; Response Elements; Role; Serine; Signal Transduction; Site; Site-Directed Mutagenesis; Small Interfering RNA; Specific qualifier value; Specificity; Testing; Therapeutic; Work; base; casein kinase II; cell type; cofactor; cost effective; design; diabetic; economic cost; genome-wide; human RIPK1 protein; improved; in vivo; insulin sensitivity; macrophage; mutant; novel; pleiotropism; programs; receptor; response; transcription factor

DESCRIPTION (provided by applicant): The epidemic of obesity, insulin resistance and type 2 diabetes with associated co-morbidities is a daunting problem in public health. Metabolic disease involves a strong inflammatory component in which adipose tissue macrophages (M¿) play a critical pathogenic role. Glucocorticoids (GCs) remain the most common and cost-effective class of medications for managing inflammatory diseases however, GCs are themselves diabetogenic, which hampers their therapeutic utility. In M¿, GCs broadly inhibit the production of proinflammatory mediators; moreover, GCs promote the polarization of 'alternatively activated' M2 M¿ that display an anti-inflammatory phenotype, and, paradoxically, increase insulin sensitivity. Untangling the dichotomy between the systemic vs. M2-specific metabolic actions of GCs is crucial for understanding the pathogenesis of insulin resistance and for creating anti-inflammatory drugs with improved therapeutic profiles. GCs signal through the GC receptor (GR) a ligand-regulated transcription factor of the nuclear receptor (NR) superfamily that recruits numerous coregulators to activate or repress transcription. Among those, the GR-interacting protein (GRIP) 1 is an established NR coactivator, that we have recently shown to serve as a key GR corepressor attenuating the inflammatory gene expression program in M¿. Unexpectedly, GRIP1 was also found to cooperate with non-receptor regulators in the immune system. What enables GRIP1 to selectively engage in antagonistic biological pathways or display opposite transcriptional activities is unknown. Recently, we found that GRIP1 undergoes GC-induced, GR interaction-dependent phosphorylation at multiple sites that was required for the induction of a subset of GR targets. The objective of this application is to dissect the role and mechanisms of GR-induced GRIP1 phosphorylation in M¿ as a modulator of anti-inflammatory and metabolic effects of GCs. Our central hypothesis is that liganded GR modifies its own coregulator by enabling GC-response element (GRE)-specific recruitment of GRIP1 kinases, thus dictating GRIP1 function in distinct GR transcription complexes, or preferential utilization of its activating vs. repressing properties. Our Specific Aims are to: 1) utilize our M¿-specific conditional GRIP1-deficient mice and GRIP1 phosphosite-specific antibodies to assess the genome-wide distribution of GRIP1 phospho-isoforms in M¿ and determine the functionally relevant binding sites; 2) dissect the function of putative GRIP1 kinases, cyclin-dependent kinase-9 and casein kinase-2, as GRE-specific components of GR transcription complexes; 3) identify (by blocking phosphorylation of endogenous GRIP1 or integrating GRIP1 phosphosite mutants into GRIP1-null cells) the role of GRIP1 phosphorylation in the assembly and gene regulation by GR transcription complexes, as well as in M¿ polarization and the M¿:adipocyte interactions. This work will yield detailed information on a novel mechanism contributing specificity to GR-mediated gene expression, which should reveal an important facet of metabolic control and new opportunities for the design of safer therapies for inflammatory diseases.

描述（由申请人提供）：肥胖、胰岛素抵抗和 2 型糖尿病及其相关并发症的流行是公共卫生中的一个令人畏惧的问题。代谢性疾病涉及强烈的炎症成分，其中脂肪组织巨噬细胞（M¿）发挥着关键的致病作用。糖皮质激素 (GC) 仍然是治疗炎症性疾病最常见且最具成本效益的一类药物，然而，GC 本身会导致糖尿病，这阻碍了其治疗效用。在 M¿ 中，GC 广泛抑制促炎介质的产生；此外，GC 促进“交替激活”M2 M 的极化，从而表现出抗炎表型，并且矛盾的是，增加了胰岛素敏感性。解开 GC 的全身代谢作用与 M2 特异性代谢作用之间的二分法对于了解胰岛素抵抗的发病机制以及开发具有改善治疗效果的抗炎药物至关重要。 GC 通过 GC 受体 (GR) 发出信号，GC 受体是核受体 (NR) 超家族的配体调节转录因子，可招募大量共调节因子来激活或抑制转录。其中，GR 相互作用蛋白 (GRIP) 1 是一种已确定的 NR 共激活因子，我们最近证明它可以作为关键的 GR 辅抑制因子，减弱 M¿ 中的炎症基因表达程序。出乎意料的是，GRIP1还被发现与免疫系统中的非受体调节因子合作。是什么使得 GRIP1 能够选择性地参与拮抗的生物途径或表现出相反的转录活性尚不清楚。最近，我们发现 GRIP1 在多个位点经历 GC 诱导的 GR 相互作用依赖性磷酸化，这是诱导 GR 靶标子集所需的。本申请的目的是剖析 M¿ 中 GR 诱导的 GRIP1 磷酸化作为 GC 抗炎和代谢作用调节剂的作用和机制。我们的中心假设是，配体 GR 通过启用 GRIP1 激酶的 GC 响应元件 (GRE) 特异性募集来修饰其自身的辅助调节器，从而决定 GRIP1 在不同 GR 转录复合物中的功能，或优先利用其激活与抑制特性。我们的具体目标是：1) 利用我们的 M¿ 特异性条件 GRIP1 缺陷小鼠和 GRIP1 磷酸位点特异性抗体来评估 M¿ 中 GRIP1 磷酸亚型的全基因组分布，并确定功能相关的结合位点； 2) 剖析假定的 GRIP1 激酶、细胞周期蛋白依赖性激酶 9 和酪蛋白激酶 2 的功能，作为 GR 转录复合物的 GRE 特异性成分； 3) 鉴定（通过阻断内源性 GRIP1 的磷酸化或将 GRIP1 磷酸位点突变体整合到 GRIP1 缺失细胞中）GRIP1 磷酸化在 GR 转录复合物的组装和基因调控中的作用，以及在 M¿ 极化和 M¿:脂肪细胞相互作用中的作用。这项工作将产生关于 GR 介导的基因表达特异性的新机制的详细信息，这应该揭示代谢控制的一个重要方面，并为设计更安全的炎症性疾病疗法提供新的机会。