Transforming growth factor beta1, MicroRNAs and Diabetic Nephropathy

转化生长因子 beta1、MicroRNA 和糖尿病肾病

• 批准号: 7652597
• 负责人: RAMA NATARAJAN
• 金额: $ 39.84万
• 依托单位: BECKMAN RESEARCH INSTITUTE/CITY OF HOPE
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-05-01 至 2014-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7652597
• 关键词: Adopted; Arts; Attenuated; Binding; Binding Sites; Biochemical Pathway; Biological; Biological Assay; Biological Process; Boxing; Collagen; Collagen Gene; Complications of Diabetes Mellitus; Data; Deposition; Development; Diabetes Mellitus; Diabetic Nephropathy; Diabetic mouse; Disease; Dose; Down-Regulation; Effectiveness; Elements; End stage renal failure; Extracellular Matrix; Extracellular Matrix Proteins; Family; Fibrosis; Figs - dietary; Functional RNA; Functional disorder; Gene Expression; Gene Expression Profile; Gene Expression Regulation; Gene Targeting; Genes; Genetic Transcription; Healthcare; In Vitro; Insulin-Dependent Diabetes Mellitus; Kidney; Kidney Diseases; Knockout Mice; Lead; Luciferases; Mediating; Messenger RNA; MicroRNAs; Modeling; Modification; Molecular; Morbidity - disease rate; Nuclear; Nucleotides; Oligonucleotides; Pathogenesis; Play; Production; Proteins; Publishing; RNA Processing; RNA-Binding Proteins; Receptors, Adrenergic, beta-1; Regulation; Relative (related person); Renal function; Reporter; Repression; Research; Role; Signal Transduction; Small RNA; Streptozocin; Testing; Text; Therapeutic; Time; Toxic effect; Translations; Up-Regulation; alpha 2 collagen type I; alpha2 Chain Collagen Type I; base; c-ets1 transcription factor; chromatin immunoprecipitation; diabetic; feeding; glomerulosclerosis; human TGFB1 protein; improved; in vivo; locked nucleic acid; loss of function; member; mesangial cell; mortality; mouse model; new therapeutic target; novel; promoter; public health relevance; research study; transcription factor

DESCRIPTION (provided by applicant): Diabetic nephropathy (DN) is one of the major complications of diabetes that can lead to end stage renal disease. Key features of DN include increased glomerulosclerosis and mesangial cell widening due to extracellular matrix (ECM) deposition. Although several biochemical pathways and key profibrotic factors, such as transforming growth factor-beta 1 (TGF-¿) and the ECM protein collagen, have been implicated in the pathogenesis of DN, the subtle molecular and nuclear mechanisms regulating them are unclear. We recently uncovered a novel connection between key gene targets of TGF-¿ in mesangial cells (MCs) and members of a family of small non-coding RNAs called micro-RNAs (miRs). Increasing evidence shows that miRs play important roles in gene regulation since they can suppress the expression of target genes by binding to their mRNAs. Although several targets of miRs have been predicted, much needs to be done to determine their biological and disease relevance. The mechanisms by which miRs are regulated under normal and disease conditions are also not clear. We propose to explore these aspects in the context of DN. We discovered that TGF-¿ downregulates key repressive factors involved in collagen regulation, and that these factors are also targeted and downregulated by two specific miRs expressed in the kidney and MCs. The expressions of these miRs are increased in MCs treated with TGF-¿ and also in the glomeruli of diabetic mice. Furthermore, we observed that these miRs can trigger regulatory and feed forward mechanisms that enhance the expression of collagen. We therefore put forward the novel hypothesis that increased TGF-¿ in DN leads to the aberrant production and actions of key miRs and their target genes which result in enhanced glomerulosclerosis. Specific Aim 1 will examine the transcriptional mechanisms by which TGF-¿ upregulates a master miR and its downstream effector miR in MCs. Specific Aim 2 will evaluate the specific gene target of the downstream miR and how it contributes to TGF-¿ mediated collagen regulation. Specific Aim 3 will test the in vivo functional relevance by evaluating the therapeutic potential of anti-miR oligo-nucleotides in diabetic mice, and by examining the progression of DN in a miR knockout mouse. Our preliminary results have uncovered novel hitherto unexplored mechanisms of action of TGF-¿. This state-of-the-art study could break new ground and have a major impact in the field of renal research by deciphering the biological functions of these elusive small RNAs in the kidney. They could also pave the way for novel new therapies for diabetic kidney disease. PUBLIC HEALTH RELEVANCE: Diabetes is highly prevalent in the USA and a major healthcare problem. This is further magnified by the fact that it is associated with significantly accelerated and debilitating complications such as diabetic nephropathy. This project proposes to identify novel new mechanisms involved that could lead to the development of sorely needed newer therapies to reduce the morbidity and mortality of diabetic nephropathy.

描述（由申请人提供）：糖尿病肾病（DN）是糖尿病的主要并发症之一，可导致终末期肾脏疾病。DN的主要特征包括肾小球硬化加重和细胞外基质（ECM）沉积引起的系膜细胞增宽。虽然几种生化途径和关键的促纤维化因子，如转化生长因子- β 1 （TGF-¿）和ECM蛋白胶原蛋白，都与DN的发病有关，但调控它们的微妙分子和核机制尚不清楚。我们最近发现了TGF-¿在系膜细胞（MCs）中的关键基因靶点与称为微rna （miRs）的小非编码rna家族成员之间的新联系。越来越多的证据表明，miRs可以通过结合靶基因的mrna抑制靶基因的表达，在基因调控中发挥重要作用。虽然已经预测了miRs的几个靶点，但要确定它们的生物学和疾病相关性还需要做很多工作。mir在正常和疾病条件下的调节机制也不清楚。我们建议在DN的背景下探讨这些方面。我们发现TGF-¿下调参与胶原蛋白调节的关键抑制因子，这些因子也被肾脏和MCs中表达的两种特异性miRs靶向和下调。TGF-¿处理的MCs和糖尿病小鼠肾小球中这些miRs的表达均增加。此外，我们观察到这些miRs可以触发调节和前馈机制，增强胶原蛋白的表达。因此，我们提出了新的假设，即DN中TGF-¿的增加导致关键miRs及其靶基因的异常产生和作用，从而导致肾小球硬化的加剧。特异性目的1将研究TGF-¿在MCs中上调主miR及其下游效应miR的转录机制。Specific Aim 2将评估下游miR的特定基因靶点及其如何参与TGF-¿介导的胶原调节。特异性Aim 3将通过评估抗miR寡核苷酸在糖尿病小鼠中的治疗潜力，以及在miR敲除小鼠中检测DN的进展，来测试其体内功能相关性。我们的初步结果揭示了迄今为止未知的TGF-¿的作用机制。这项最新的研究可以通过破译肾脏中这些难以捉摸的小rna的生物学功能，在肾脏研究领域开辟新的领域并产生重大影响。它们还可能为糖尿病肾病的新疗法铺平道路。公共卫生相关性：糖尿病在美国非常普遍，是一个主要的卫生保健问题。它与糖尿病肾病等显著加速和衰弱性并发症相关，这一事实进一步放大了这一点。该项目旨在确定新的机制，从而开发出迫切需要的新疗法，以降低糖尿病肾病的发病率和死亡率。