PHARMACOLOGICAL RESCUE OF MUTANT LAMININ IN NEPHROTIC SYNDROME

突变层粘连蛋白对肾病综合征的药理学拯救

基本信息

批准号：
8953410
负责人：
Ying Maggie Chen
金额：
$ 7.63万
依托单位：
WASHINGTON UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-08-01 至 2017-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8953410
关键词：
Accounting Animal Model Apoptosis Apoptotic Attenuated Biological Assay Cells Chemicals Combined Modality Therapy Complex DNA Sequence Alteration Data Destinations Development End stage renal failure Endoplasmic Reticulum Functional disorder Genes Genetic Goals Human Hypoalbuminemia In Vitro Individual Injury Kidney Diseases Kidney Failure Knock-out Laminin Lead MG132 Mediating Missense Mutation Molecular Chaperones Morbidity - disease rate Mus Mutant Strains Mice Mutate Mutation Nephrotic Syndrome Pathway interactions Patients Pharmaceutical Preparations Pharmacologic Substance Preclinical Testing Proteasome Inhibitor Protein Conformation Proteins Proteinuria Rattus Renal function Research Risk Signal Transduction System Taurodeoxycholate Therapeutic Therapeutic Intervention Therapeutic Uses Time Transgenic Mice Ubiquitin Western Blotting Wild Type Mouse attenuation base biological adaptation to stress cost effective therapy endoplasmic reticulum stress glomerular basement membrane improved in vivo innovation lamin B2 loss of function mortality mouse model multicatalytic endopeptidase complex mutant nephrin novel strategies novel therapeutics podocyte promoter protein degradation protein misfolding public health relevance small molecule trafficking treatment effect treatment strategy

项目摘要

DESCRIPTION (provided by applicant): Nephrotic syndrome (NS) is characterized by heavy proteinuria, hypoalbuminemia, and increased risk of progressive loss of kidney function. It causes serious morbidity and high mortality, accounting for 15% of prevalent end-stage renal disease at an annual cost of more than $3 billion in the US. There is no effective treatment for most cases of NS associated with genetic mutations. Our research has been focused on a monogenic form of NS caused by missense mutations of LAMB2, one of the most commonly mutated genes in NS. Laminin 2 encoded by LAMB2 is a component of laminin-521 ( 5 2 1), the major laminin trimer of the glomerular basement membrane (GBM). Using our established cell and knockout/transgenic mouse models, we have found that inhibited secretion of misfolded C321R-LAMB2 from podocytes to the GBM and the resulting podocyte endoplasmic reticulum (ER) stress lead to proteinuria. In addition, increased accumulation of the mutant in the GBM alleviates proteinuria. Therefore, restoring defective trafficking of the mutant laminin and rescuing misfolded 2 proteins to reach their functional destination are hopeful therapeutic strategies. The overall goal of this research is to investigate a novel strategy for therapeutic intervention in genetic forms of NS. To accomplish our research goal, we have generated a NS mouse model (Lamb2-/-; NEPH- C321R-LAMB2 mice) in which podocyte-targeted expression of the mutant form of rat LAMB2 (C321R-LAMB2) via the mouse nephrin promoter (NEPH) replaces the wild-type mouse LAMB2. Our preliminary data show that the misfolded mutant protein is much more susceptible to protein degradation, which is mediated by the ubiquitin-proteasome pathway. More excitingly, a combination of a chemical chaperone correcting protein misfolding and a proteasome inhibitor blocking protein degradation elicit a much more pronounced pro- secretion effect as compared to the chemical chaperone alone in vitro. Thus, the effect of combined treatment regulating both protein misfolding and degradation will be further investigated in our NS mouse model. The proposed study will assay the feasibility for therapeutic use of chemical chaperones in combination with proteasome inhibitors in a NS animal model. The results may have significant therapeutic implications for the treatment of familial or sporadic NS patients caused by aberrant ER proteostasis and podocyte ER dysfunction.

描述（由申请人提供）：肾病综合征（NS）的特点是大量蛋白尿、低蛋白血症和肾功能进行性丧失的风险增加，它导致严重的发病率和高死亡率，占目前流行的终末期肾病的 15%。美国每年的费用超过 30 亿美元，对于大多数与基因突变相关的 NS 病例没有有效的治疗方法，我们的研究重点是由错义突变引起的单基因形式的 NS。 LAMB2 是 NS 中最常见的突变基因之一，由 LAMB2 编码，是层粘连蛋白 521 (5 2 1) 的组成部分，层粘连蛋白是肾小球基底膜 (GBM) 的主要层粘连蛋白三聚体。在转基因小鼠模型中，我们发现抑制错误折叠的 C321R-LAMB2 从足细胞分泌到 GBM 以及由此产生的足细胞内质此外，GBM 中突变体积累的增加可缓解蛋白尿，因此，恢复突变层粘连蛋白的运输缺陷并挽救错误折叠的 2 种蛋白质以达到其功能目的地是有希望的治疗策略。这项研究的目的是研究一种治疗干预 NS 遗传形式的新策略为了实现我们的研究目标，我们建立了 NS 小鼠模型（Lamb2-/-；NEPH-）。 C321R-LAMB2小鼠），其中通过小鼠去氧肾上腺素启动子（NEPH）足细胞靶向表达突变型大鼠LAMB2（C321R-LAMB2）取代了野生型小鼠LAMB2。我们的初步数据表明错误折叠的突变蛋白很多。更容易受到泛素蛋白酶体途径介导的蛋白质降解，更令人兴奋的是，化学伴侣纠正蛋白质错误折叠和与体外单独的化学伴侣相比，阻断蛋白质降解的蛋白酶体抑制剂引起更显着的促分泌作用，因此，将在我们的 NS 小鼠模型中进一步研究调节蛋白质错误折叠和降解的联合治疗的效果。该研究将在 NS 动物模型中分析化学伴侣与蛋白酶体抑制剂联合治疗的可行性，结果可能对治疗由异常 ER 引起的家族性或散发性 NS 患者具有重要的治疗意义。蛋白质稳态和足细胞 ER 功能障碍。