Glucocorticoid Regulation of NF-kB Function by O-GlcNAc

O-GlcNAc 糖皮质激素对 NF-kB 功能的调节

• 批准号: 6741199
• 负责人: Xiaoyong Yang
• 金额: $ 4.73万
• 依托单位: SALK INSTITUTE FOR BIOLOGICAL STUDIES
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-09-01 至 2007-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6741199
• 关键词: RNA interference; biochemistry; biological signal transduction; chromatin immunoprecipitation; corticosteroid receptors; enzyme activity; gene induction /repression; glycosyltransferase; immune response; immunoregulation; inflammation; nuclear factor kappa beta; postdoctoral investigator; protein protein interaction; transfection

DESCRIPTION (provided by applicant): NF-kappaB-induced activation of proinflammatory genes can be completely repressed by the glucocorticoid receptor upon hormone binding. However, critical cofactors and mechanism that transmit the glucocorticoid signal into the NF-kappaB pathway remain elusive. We recently defined O-GIcNAc transferase (OGT) as an atypical mediator in gene repression. Hence, our first specific aim is to explore the role of this enzyme as a candidate corepressor for the glucocorticoid receptor in antiinflammatory responses. We will test a physical interaction between OGT and the glucocorticoid receptor by biochemical approaches and will examine their functional interaction by cell-based gene reporter assays. Using RNA interference, we will assess a possible role of OGT in regulating endogenous proinflammatory genes. Unlike OGT, little is known about the impact of the opposing enzyme O-Incase (OGN) on transcription. Hence, our second specific aim is to discern how these two reciprocal enzymes contribute to the activation or inhibition of the proinflammatory genetic network. Using a chromatin immunoprecipitation assay, we will study the dynamics of OGT and OGN at the promoters of either active or repressive proinflammatory genes. Moreover, we will seek to identify upstream regulators and downstream targets of these two enzymes in the transcriptional apparatus through biochemical approaches. This study is designed to delineate a precise mechanism by which O-GIcNAc regulates transcription. As glucocorticoids are currently used to treat inflammation and cancer, understanding their action via O-GIcNAc offers a new approach to treatment and drug designs.

描述（由申请人提供）：NF-κB诱导的促炎基因激活可在激素结合后被糖皮质激素受体完全抑制。然而，将糖皮质激素信号传递到 NF-κB 通路的关键辅助因子和机制仍然难以捉摸。我们最近将 O-GlcNAc 转移酶 (OGT) 定义为基因抑制中的非典型介质。因此，我们的第一个具体目标是探索这种酶作为糖皮质激素受体在抗炎反应中的候选辅阻遏物的作用。我们将通过生化方法测试 OGT 和糖皮质激素受体之间的物理相互作用，并将通过基于细胞的基因报告分析检测它们的功能相互作用。使用 RNA 干扰，我们将评估 OGT 在调节内源性促炎基因中的可能作用。与 OGT 不同，我们对相反酶 O-Incase (OGN) 对转录的影响知之甚少。因此，我们的第二个具体目标是了解这两种相互作用的酶如何促进促炎基因网络的激活或抑制。使用染色质免疫沉淀测定，我们将研究活性或抑制性促炎基因启动子处的 OGT 和 OGN 动态。此外，我们将寻求通过生化方法来确定转录装置中这两种酶的上游调节因子和下游靶标。本研究旨在描绘 O-GlcNAc 调节转录的精确机制。由于糖皮质激素目前用于治疗炎症和癌症，通过 O-GIcNAc 了解其作用为治疗和药物设计提供了一种新方法。