Restoring Ocrl1 function in Lowe Syndrome and Dent-2 disease

恢复 Lowe 综合征和 Dent-2 疾病中的 Ocrl1 功能

基本信息

批准号：
10344291
负责人：
Ruben Claudio Aguilar
金额：
$ 34.54万
依托单位：
PURDUE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-09-20 至 2026-06-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10344291
关键词：
Active Sites Address Adolescence Affect Affinity Age Algorithms Allosteric Site Animal Model Behavior Binding Biological Models Birth Cataract Cell Line Cessation of life Child Complement Dextrans Disease Enzyme Kinetics Enzymes Equilibrium FDA approved Genes Genetic Diseases Glaucoma In Vitro Investigation Kidney Kidney Calculi Kidney Failure Lead Lipids Maps Measurement Mental Retardation Missense Mutation Modeling Modification Molecular Conformation Mutate Mutation Nature Oculocerebrorenal Syndrome Organoids Oxalates Patients Pharmaceutical Preparations Phenotype Phosphoric Monoester Hydrolases Process Proteins Proteinuria Publishing Renal function Research Risk Management Safety Series Structure Symptoms Techniques Testing Therapeutic Therapeutic Agents Therapeutic Index Toxic effect Toxicology Variant Zebrafish cilium biogenesis conformer design disease-causing mutation drug action drug candidate experimental study kidney cell mutant novel therapeutic intervention patient subsets remediation small molecule translational impact uptake

项目摘要

Lowe Syndrome (LS) is a disease caused by mutations in the OCRL1 gene that unfortunately leads to the early death of affected children and has no cure. However, this project aims to change such scenario. Further, since OCRL1 mutations also cause a related renal condition known as Dent-2 (D2) disease, this proposal will also benefit D2 patients. LS patients display mental retardation, ocular (e.g., glaucoma, cataracts) and renal (e.g., kidney stones, LMW proteinuria) abnormalities, while D2 patients show renal symptoms almost exclusively. Although most OCRL1 missense mutations found in patients alter the phosphatase domain of the encoded protein Ocrl1, about half of these changes do not affect residues involved in binding or modification of the substrate. In fact, our results indicate that a substantial number of patients express Ocrl1 mutated proteins with intact binding/catalytic sequences but locked in a conformation unable to process lipid substrates. Therefore, we HYPOTHESIZE that a subset of Ocrl1 patient mutated proteins can re-acquire functionality by action of drugs able to stabilize the enzymatically active conformer (allosteric activators). Indeed, as a result of a series of small molecule screens performed in our lab, we identified a group of compounds (including FDA-approved drugs) as able to restore catalytic activity of different Ocrl1 patient mutants and to suppress a readout LS/D2 cellular phenotype. To test our hypothesis, 4 allosteric activator candidates will be used along with a panel of LS and D2 Ocrl1 patient mutated variants to pursue the following specific aims focused on kidney function: AIM 1. To determine the in vitro effect of selected candidate drugs ON THE BIOCHEMICAL ACTIVITY of a panel of Ocrl1 LS/D2 patient mutated variants. AIM 2. To determine the effect of selected candidate drugs ON MULTIPLE LS PHENOTYPES observed in kidney cell lines, kidney organoids and a zebrafish animal model bearing LS/D2 patient OCRL1 mutations. AIM 3. To determine the effect of selected candidate drugs ON THE STABILITY AND STRUCTURE of the Ocrl1 LS/D2 mutated variants bound or not to substrate. This project is INNOVATIVE because it introduces the concept of LS and D2 as heterogenous conditions with some patients displaying a conformational/misfolding disease component and proposes a novel therapeutic approach using allosteric activators. Importantly, this project has high SIGNIFICANCE as it will address the lack of therapeutic approaches designed to suppress the upstream cause of a disease that affects tens of thousands of children in the US and worldwide. Further, FDA-approved candidate drugs currently used to ameliorate other conditions can be readily repurposed to LS/D2. Therefore, the translational IMPACT of this project is very high.

Lowe 综合征 (LS) 是一种由 OCRL1 基因突变引起的疾病，不幸的是，该疾病会导致受影响的儿童早逝且无法治愈。然而，这个项目旨在改变这种情况。更远，由于 OCRL1 突变还会引起一种称为 Dent-2 (D2) 疾病的相关肾脏疾病，因此该提案将也使 D2 患者受益。 LS 患者表现出智力低下、眼部（例如青光眼、白内障）和肾部（例如肾结石、 LMW 蛋白尿）异常，而 D2 患者几乎只表现出肾脏症状。虽然大多数在患者中发现的 OCRL1 错义突变改变了编码蛋白 Ocrl1 的磷酸酶结构域，大约这些变化中有一半不影响参与底物结合或修饰的残基。事实上，我们的结果表明，大量患者表达具有完整结合/催化功能的 Ocrl1 突变蛋白序列，但锁定在无法处理脂质底物的构象中。因此，我们假设 Ocrl1 患者突变蛋白的子集可以通过能够稳定的药物的作用重新获得功能酶活性构象异构体（变构激活剂）。事实上，由于一系列小分子通过在我们实验室进行的筛选，我们确定了一组化合物（包括 FDA 批准的药物）能够恢复不同 Ocrl1 患者突变体的催化活性并抑制读出 LS/D2 细胞表型。为了检验我们的假设，将使用 4 种变构激活剂候选物以及一组 LS 和 D2 Ocrl1 患者突变变体以追求以下针对肾功能的特定目标：目的 1. 确定所选候选药物对一组生物化学活性的体外影响 Ocrl1 LS/D2 患者突变变体。目的 2. 确定所选候选药物对肾脏中观察到的多种 LS 表型的影响细胞系、肾类器官和带有 LS/D2 患者 OCRL1 突变的斑马鱼动物模型。目的 3. 确定所选候选药物对 Ocrl1 稳定性和结构的影响 LS/D2 突变变体与底物结合或不结合。这个项目是创新的，因为它引入了 LS 和 D2 作为异质条件的概念一些患者表现出构象/错误折叠疾病成分，并提出了一种新的治疗方法使用变构激活剂的方法。重要的是，该项目具有很高的意义，因为它将解决缺乏旨在抑制影响数以万计的疾病的上游病因的治疗方法美国和世界各地的儿童。此外，FDA 批准的候选药物目前用于改善其他症状条件可以很容易地重新用于 LS/D2。因此，该项目的转化影响力非常高。