Mutant Laminin Chains and Nephrotic Syndrome

层粘连蛋白链突变与肾病综合征

基本信息

批准号：
8723163
负责人：
Ying Maggie Chen
金额：
$ 12.83万
依托单位：
WASHINGTON UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2010
资助国家：
美国
起止时间：
2010-09-15 至 2016-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8723163
关键词：
Affect Amino Acid Sequence Animal Model Attenuated Biological Assay Cells Chemicals Childhood Congenital Nephrotic Syndrome Cultured Cells Data Defect Deposition Destinations Disease Endoplasmic Reticulum Engineering Exhibits Extracellular Matrix Goals Human In Vitro Kidney Kidney Diseases Kidney Failure Laminin Lead Missense Mutation Molecular Molecular Chaperones Molecular Weight Mus Mutant Strains Mice Mutation Nephrotic Syndrome Neurologic Pathogenesis Patients Peptide Sequence Determination Phenotype Point Mutation Production Protein Conformation Proteins Proteinuria Reporting Research Scheme Syndrome Taurodeoxycholic Acid Testing Therapeutic Therapeutic Uses Transgenes Transgenic Mice Variant WT1 gene endoplasmic reticulum stress glomerular basement membrane human disease improved in vivo lamin B2 mouse model mutant nephrin null mutation podocyte polymerization promoter protein folding protein misfolding public health relevance response scaffold trafficking

项目摘要

DESCRIPTION (provided by applicant): Laminin (2 (LAMB2) is a component of Laminin-521, the major laminin trimer of the kidney glomerular basement membrane (GBM). Null mutations in LAMB2 cause Pierson syndrome, characterized by congenital nephrotic syndrome with severe ocular and neurological defects. In contrast, most missense LAMB2 mutations, such as R246Q, cause isolated congenital nephrotic syndrome. To investigate the mechanisms whereby missense mutations cause proteinuria, we have generated transgenic mice in which R246Q mutant (2 is expressed in podocytes at different levels and replaces normal (2 in the GBM. Our preliminary data show that these mice exhibit proteinuria that can be attenuated by increased deposition of mutant R246Q-LAMB2 into the GBM. Moreover, in vitro, secretion of mutant LAMB2 proteins is severely inhibited compared to wild-type. Therefore, we hypothesize that pathogenic LAMB2 point mutations cause protein misfolding, ER stress, and secretion defects both in vitro and in vivo. Chemical chaperones, such as taurodeoxycholic acid (TUDCA), are low molecular weight compounds that can stabilize protein conformation and rescue trafficking-defective misfolded proteins. We have shown that TUDCA treatment of cells expressing the mutants significantly increases the secretion of mutant LAMB2 proteins into the medium. We propose, therefore, that chemical chaperones can improve the folding of mutant LAMB2 proteins, reduce ER stress, and improve the secretion of mutant laminin trimers into the GBM, thereby attenuating proteinuria in Lamb2-/-; mutLAMB2 transgenic mice. To test these hypotheses, we will: 1. Examine whether LAMB2 point mutations cause protein misfolding and ER stress both in vitro and in vivo. 2. Determine whether chemical chaperones can improve the secretion of LAMB2 point mutants and reduce ER stress in vitro. 3. Investigate whether chemical chaperones improve secretion of mutant laminin (2 and attenuate proteinuria in Lamb2-/-; mutLAMB2 mice. These studies will help us to understand the molecular mechanisms underlying the pathogenesis of congenital nephrotic syndrome and assay the feasibility for therapeutic use of chemical chaperones in a relevant animal model. Our results may have significant therapeutic implications for the treatment of congenital nephrotic syndrome in patients carrying missense LAMB2 mutations.

描述（由申请人提供）：层粘连蛋白（2（LAMB2）是层粘连蛋白521的组成部分，肾小球肾小球蛋白的主要层粘连蛋白三聚体（GBM）。lamb2中的无效突变导致皮尔森综合征在pierson综合征中，由过度的肾上腺素综合征和凸起的大多数凸起的凸起，在凸起。 R246q，导致孤立的先天性肾病综合征研究，使错过突变引起蛋白尿的机制，我们已经产生了R246Q突变体的转基因小鼠（2在脚下表达2个以不同的水平表达R246Q-LAMB2在GBM中，在体外，与野生型相比，突变的Lamb2蛋白的分泌受到严重抑制。化学伴侣，例如牛头陶胆酸（TUDCA），是低分子量化合物，可以稳定蛋白质构象并营救运输缺陷型错误折叠蛋白。我们已经表明，表达突变体的细胞的TUDCA处理可显着增加突变兰布2蛋白的分泌到培养基中。因此，我们提出，化学伴侣可以改善突变型LAMB2蛋白的折叠，减轻ER应激，并改善突变层粘连蛋白三聚体向GBM的分泌，从而减弱lamb2 - / - 中的蛋白尿； mutlamb2转基因小鼠。为了检验这些假设，我们将： 1。检查lamb2点突变是否引起蛋白质折叠和质网应激体外和体内。 2。确定化学伴侣是否可以改善LAMB2点的分泌突变体并在体外减轻质心质网应力。 3。研究化学伴侣是否改善突变层粘连蛋白的分泌（2和在lamb2-/ - 衰减蛋白尿mutlamb2小鼠。这些研究将有助于我们了解先天性肾病综合征发病机理的基础的分子机制，并在相关的动物模型中测定化学伴侣治疗使用的可行性。我们的结果可能对携带错义LAMB2突变患者的先天性肾病综合征的治疗具有显着的治疗意义。