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

调节 NF-kB 的新靶点

• 批准号: 8318211
• 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 2014-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8318211
• 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越来越严重的流行病，仅在美国，疾病预防控制中心估计有2400万人直接受到影响。有两种相互联系的途径在糖尿病的发作中至关重要。它们是营养衍生的代谢途径，也是促炎途径。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。我们已经确定了两个新型的转录激活剂相互作用，以控制和调节代谢和炎症途径。两个转录激活剂NF-：B（核因子 - ：B）和SREBP（固醇调节元件结合蛋白）在糖尿病的发作和进展中起着重要作用。这两个因素均已证明与称为激活剂募集的共同因素（ARC）/中介体复合物的共激活因子在功能上相互作用。 NF-：B和SREBP对于调节糖尿病发作的许多基因的表达至关重要。我们建议靶向这两个转录因子（SREBP和NF-：B）与小分子效应子的激活剂 - 辅助相互作用，从而抑制基因激活。 SREBP和NF-：B的激活因子介导者的相互作用代表新靶标，因为它们的抑制作用会影响其激活途径中最下游元件。我们将通过溶液状态NMR确定构成相互作用的最小元素的结构（即，在介体中与激活剂的反式激活域（TAD）（TAD）中的Kix结构域的复合物的结构。我们将通过高通量筛选来鉴定每种激活剂 - 介导相互作用的小分子抑制剂，并在体外转录测定中验证它们。随后，我们将研究这些抑制剂对3T3-L1前脂肪细胞细胞中基因转录和脂肪细胞分化的影响。这将构成未来研究的基础，在此研究中，在此鉴定和表征的抑制剂将在C.级别和糖尿病鼠模型中进行测试。此外，我们试图阐明一种由Let-7 Micro-RNA策划的SREBP靶基因调节的新机制。已知微RNA可以调节一组基因的mRNA水平，从而协同调节整个途径。我们假设Let-7调节PGC-1共激活剂的水平，这反过来调节SREBP靶基因，并有望对脂质发生和线粒体生物发生有深远的影响。 公共卫生相关性：近年来糖尿病已成为越来越严重的流行病。营养衍生的代谢途径和促炎途径在糖尿病的发作中至关重要，我们已经确定了控制和调节这些途径的两种新型转录激活剂相互作用。我们打算通过鉴定激活剂 - 介导相互作用的小分子抑制剂并了解这些途径中微RNA的内源基因调节来靶向这些途径中的基因激活。