Molecular Mechanisms of Mesangial Sclerosis

系膜硬化的分子机制

• 批准号: 7578923
• 负责人: CHRISTINE KREGER ABRASS
• 金额: $ 32.38万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-03-01 至 2012-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7578923
• 关键词: Actin-Binding Protein; Actins; Aftercare; Appearance; Binding; C-terminal; Cell Nucleus; Cell physiology; Cells; Cleaved cell; Complex; Data; Development; Diabetic Nephropathy; Disease; FHL2 gene; Figs - dietary; Focal Adhesions; Gene Expression; Gene Targeting; Generations; Genes; Genetic Transcription; Goals; Hyperglycemia; Indium; Insulin-Like Growth Factor Binding Protein 5; Integrins; Kidney Diseases; LIM Domain Protein; Laminin; Mediating; Molecular; Nuclear; Nuclear Protein; Nuclear Proteins; Phenotype; Phosphorylation; Play; Process; Progress Reports; Protein Isoforms; Recruitment Activity; Renal glomerular disease; Research Personnel; Role; Sclerosis; Stimulus; Stress Fibers; Transcriptional Regulation; base; crosslink; filamin; insight; laminin-9; mesangial cell; nephrogenesis; novel; programs; promoter; rho GTP-Binding Proteins; transcription factor

Temporal and spatial expression of laminin (LN)isoforms is critical to glomerular development and contributes to altered cell function in diabetic nephropathy and other progressive renal diseases. Yet, little is known about the mechanisms that regulate LN isoform expression. We propose that insulin-like growth factor binding protein-5 (IGFBP-5) leads to formation of a filamin-based nuclear shuttle that binds transcription factors (e.g.sox9, GKLF, Sp1, Smad) and transcriptional co-activators (e.g., IGFBP-5 and LIM domain proteins such as FHL2) and regulates laminin (LN)isoform expression in mesangial cells (MC). This hypothesis suggests a novel mechanism whereby perturbations in the cell-matrix interface regulate gene expression. This hypothesis will be examined by: Specific Aim 1: To characterize the generation and composition of the filamin nuclear shuttle following treatment of MC with IGFBP-5. First, we will demonstrate that a fragment of filamin forms and translocates to the nucleus. Second, we will characterize the transcription factors that are recruited to the complex; and finally, we will evaluate the role of transcriptional co-activators, LIM domain protein FHL2 and IGFBP-5, in the complex. Specific Aim 2: To demonstrate that nuclear accumulation of filamin is required for IGFBP-5-mediated changes in LN gene expression. First, we will demonstrate that filamin is required for IGFBP-5-mediated effects on LN gene expression. Second, we will show that the filamin shuttle is recruited to LN gene loci where it specifically midifies LN gene transcription. Specific Aim 3: To define the mechanisms whereby the filamin nuclear shuttle activates LN gene transcription. First, we will determine if FLN interacts directly with the LN promoter and if it drives transcription. Second, we will define the elements in the shuttle that are required for transcriptional control. These studies will define the role of a filamin-based nuclear shuttle in mediating the effects of IGFBP-5 on laminin gene expresison. Understanding transcriptional control of LN isoform expression will add new insights into the role that LN plays in normal glomerulogenesis and that becomes disordered in glomerular disease.

层粘连蛋白（LN）亚型的时空表达对肾小球发育至关重要， 导致糖尿病肾病和其他进行性肾病中细胞功能改变。然而， 了解调节LN亚型表达的机制。我们认为胰岛素样生长 因子结合蛋白-5（IGFBP-5）导致形成基于细丝蛋白的核穿梭， 转录因子（例如sox 9、GKLF、Sp1、Smad）和转录共激活因子（例如，IGFBP-5和LIM 结构域蛋白如FHL 2）并调节肾小球系膜细胞（MC）中层粘连蛋白（LN）同种型表达。这 一种假说提出了一种新的机制，即细胞-基质界面的扰动调节基因 表情这一假设将通过以下方式进行检验： 具体目的1：表征细丝蛋白核穿梭体的产生和组成， 用IGFBP-5治疗MC。首先，我们将证明细丝蛋白片段的形成和易位， 原子核第二，我们将描述被募集到复合物中的转录因子的特征; 最后，我们将评估转录辅激活因子LIM结构域蛋白FHL 2和IGFBP-5在 复杂的。 具体目的2：证明IGFBP-5介导的细胞凋亡需要细丝蛋白的核积累。 LN基因表达的变化。首先，我们将证明细丝蛋白是IGFBP-5介导的 影响LN基因表达。其次，我们将证明细丝蛋白穿梭体被募集到LN基因位点， 它特异性地抑制LN基因的转录。 具体目标3：确定细丝蛋白核穿梭激活LN基因的机制 转录。首先，我们将确定FLN是否直接与LN启动子相互作用， 转录。第二，我们将定义穿梭中转录控制所需的元件。 这些研究将确定细丝蛋白为基础的核穿梭在介导IGFBP-5的作用， 层粘连蛋白基因表达了解LN亚型表达的转录控制将增加新的 深入了解LN在正常肾小球形成中的作用，以及在肾小球疾病中LN的作用。 疾病