Novel targets to regulate NF-kB & SREBP activity: an approach to combat diabetes

调节 NF-kB 的新靶点

• 批准号: 8150351
• 负责人: Haribabu Arthanari
• 金额: $ 15.18万
• 依托单位: HARVARD MEDICAL SCHOOL
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-30 至 2013-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8150351
• 关键词: 3T3-L1 Cells; Adipocytes; Affect; Binding; Binding Proteins; Biogenesis; Biological Assay; Blood; Brown Fat; Caenorhabditis elegans; Cell Culture Techniques; Cells; Centers for Disease Control and Prevention (U.S.); Chemicals; Cholesterol; Complement Factor B; Complex; Critical Pathways; Diabetes Mellitus; Elements; Epidemic; Family; Fluorescence Polarization; Future; Gene Activation; Gene Expression; Gene Expression Regulation; Gene Targeting; Genes; Genetic Transcription; Homeostasis; In Vitro; Indium; Inflammatory; Insulin; Life; Lipids; MED15; Mediator of activation protein; Messenger RNA; Metabolic; Metabolic Pathway; Metabolic stress; Metabolism; Methods; MicroRNAs; Mitochondria; Modeling; Molecular; Mus; NF-kappa B; NMR Spectroscopy; Nuclear; Outcome; Pathway interactions; Play; Recruitment Activity; Regulation; Regulatory Element; Respiration; Role; Solutions; Sterols; Structure; Testing; Therapeutic Intervention; Trans-Activators; Transactivation; Transcription Coactivator; Transcriptional Regulation; Triglycerides; United States; adipocyte differentiation; base; cellular imaging; combat; diabetic; glucose metabolism; high throughput screening; in vivo; inhibitor/antagonist; lipid biosynthesis; lipid metabolism; novel; p65; protein expression; public health relevance; small molecule; transcription factor

DESCRIPTION (provided by applicant): Diabetes has become an increasingly serious epidemic in recent years, with CDC estimates of 24 million people directly affected in the United States alone. There are two interconnected pathways that are critical in the onset of diabetes. They are the nutritionally-derived metabolic pathway, and the pro-inflammatory pathway. Aberrant activation of both the above pathways is commonly found to be associated with the pathological progression of diabetes. We have identified two novel transcription activator-Mediator interactions that control and regulate the metabolic and inflammatory pathway. The two transcription activators, NF-:B (Nuclear Factor- :B) and SREBP (Sterol Regulatory Element-Binding Protein), play significant roles in the onset and progression of diabetes. Both these factors have been shown to functionally interact with a co-activator known as the Activator Recruited Co-factor(ARC)/Mediator Complex. NF-:B and SREBP are critical in regulating the expression of a number of genes involved in the onset of diabetes. We propose to target the activator-Mediator interaction of these two transcription factors (SREBP and NF-:B) with small molecular effectors, thus inhibiting gene activation. The activator-Mediator interactions of SREBP and NF-:B represent novel targets because their inhibition would affect the most downstream element in their activation pathways. We will determine the structure of the minimal elements that constitute the interaction (i.e. the complex of KIX domain in the Mediator with the transactivation domain (TAD) of the activator) by solution state NMR. We will identify small molecule inhibitors for each of the activator-Mediator interactions by high-throughput screening and validate them in an in vitro transcription assay. We will subsequently study the effect of these inhibitors on gene transcription and adipocyte differentiation, in vivo (cell culture), in 3T3-L1 pre-adipocyte cells. This will form the basis for future studies wherein the inhibitors identified and characterized here, will be tested in C.elegans and diabetic murine models. In addition, we seek to elucidate a novel mechanism of regulation of SREBP target genes orchestrated by let-7 micro-RNA. Micro-RNAs are known to modulate mRNA levels of a set of genes, thus synergistically regulating an entire pathway. We hypothesize let-7 modulates levels of PGC-1 co-activators, which in turn regulates SREBP target genes, and is expected to have profound implications in lipogenesis and mitochondrial biogenesis. PUBLIC HEALTH RELEVANCE: Diabetes has become an increasingly serious epidemic in recent years. The nutritionally-derived metabolic pathway and the pro-inflammatory pathways are critical in the onset of diabetes and we have identified two novel transcription activator-Mediator interactions that control and regulate these pathway. We intend to target gene activation in these pathways by identifying small molecule inhibitors for the activator-Mediator interactions and understand endogenous gene regulation by micro-RNAs in these pathways.

描述（由申请人提供）：近年来，糖尿病已成为一种日益严重的流行病，据 CDC 估计，仅在美国就有 2400 万人直接受到影响。有两条相互关联的途径对于糖尿病的发病至关重要。它们是营养源代谢途径和促炎途径。通常发现上述两种途径的异常激活与糖尿病的病理进展有关。我们已经确定了两种控制和调节代谢和炎症途径的新型转录激活剂-介体相互作用。两种转录激活因子 NF-:B（核因子-:B）和 SREBP（甾醇调节元件结合蛋白）在糖尿病的发病和进展中发挥着重要作用。这两个因子已被证明与称为激活剂招募辅因子 (ARC)/介导复合体的共激活剂发生功能性相互作用。 NF-:B 和 SREBP 对于调节与糖尿病发病相关的许多基因的表达至关重要。我们建议将这两种转录因子（SREBP 和 NF-:B）与小分子效应子的激活子-介导子相互作用作为目标，从而抑制基因激活。 SREBP 和 NF-:B 的激活剂-介体相互作用代表了新的靶标，因为它们的抑制会影响其激活途径中最下游的元件。我们将通过溶液态 NMR 确定构成相互作用的最小元素的结构（即介体中的 KIX 结构域与激活剂的反式激活结构域 (TAD) 的复合物）。我们将通过高通量筛选来鉴定每种激活剂-介体相互作用的小分子抑制剂，并在体外转录测定中对其进行验证。我们随后将在体内（细胞培养）中研究这些抑制剂对 3T3-L1 前脂肪细胞中基因转录和脂肪细胞分化的影响。这将为未来的研究奠定基础，其中本文鉴定和表征的抑制剂将在秀丽隐杆线虫和糖尿病小鼠模型中进行测试。此外，我们试图阐明由let-7 micro-RNA协调的SREBP靶基因调节的新机制。众所周知，微小 RNA 可以调节一组基因的 mRNA 水平，从而协同调节整个通路。我们假设 let-7 调节 PGC-1 共激活剂的水平，进而调节 SREBP 靶基因，并有望对脂肪生成和线粒体生物合成产生深远的影响。 公共卫生相关性：近年来，糖尿病已成为一种日益严重的流行病。营养源代谢途径和促炎症途径在糖尿病的发病中至关重要，我们已经确定了两种控制和调节这些途径的新型转录激活剂-介体相互作用。我们打算通过鉴定激活剂-介体相互作用的小分子抑制剂来靶向这些途径中的基因激活，并了解这些途径中 micro-RNA 的内源基因调控。