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(申请人提供)：近年来，糖尿病已成为一种日益严重的流行病，美国疾病控制与预防中心估计，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在糖尿病的发病中起着关键作用。它们是营养来源的新陈代谢途径和促炎途径。上述两条通路的异常激活通常被发现与糖尿病的病理进展有关。我们已经确定了两种新的转录激活因子-介体相互作用，它们控制和调节代谢和炎症途径。核因子-B和固醇调节元件结合蛋白在糖尿病的发生发展中起着重要的作用。这两个因子都已被证明在功能上与被称为激活剂招募的辅因子(ARC)/介体复合体的共同激活剂相互作用。核因子：B和SREBP在调节与糖尿病发病相关的一些基因的表达方面起着关键作用。我们建议针对这两个转录因子(SREBP和NF-：B)与小分子效应器的激活-介体相互作用，从而抑制基因的激活。SREBP和NF-：B的激活剂-介体相互作用是新的靶点，因为它们的抑制会影响其激活途径中最下游的元件。我们将通过溶液状态核磁共振确定组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)的复合体)。我们将通过高通量筛选确定每个激活剂-介体相互作用的小分子抑制剂，并在体外转录试验中验证它们。随后，我们将在体内(细胞培养)研究这些抑制剂对3T3-L1前脂肪细胞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，在这些研究中，这里确定和表征的抑制剂将在线虫和糖尿病小鼠模型中进行测试。此外，我们还试图阐明一种由let-7微RNA调控SREBP靶基因的新机制。已知的是，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共激活因子的水平，而PGC-1共激活因子反过来调节SREBP靶基因，并有望在脂肪形成和线粒体生物发生中产生深远影响。 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。营养来源的代谢途径和促炎途径在糖尿病的发病中起关键作用，我们已经确定了两种新的转录激活物-介体相互作用来控制和调节这些途径。我们打算通过识别激活-介体相互作用的小分子抑制物来靶向这些途径中的基因激活，并了解这些途径中微小RNA对内源性基因的调控。