Transcriptomic, therapeutic and genetic investigations of sickle cell nephropathy

镰状细胞肾病的转录组学、治疗和遗传学研究

基本信息

批准号：
9334844
负责人：
ALLISON E ASHLEY-KOCH
金额：
$ 23.85万
依托单位：
DUKE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-08-18 至 2019-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9334844
关键词：
APOL1 gene Adult Albuminuria Alleles Angiotensin-Converting Enzyme Inhibitors Architecture Autophagocytosis Biological Assay Biology CRISPR/Cas technology Candidate Disease Gene Cells Chemicals Chloride Channels Chromosomes, Human, Pair 22 Chronic Kidney Failure Clinical Clustered Regularly Interspaced Short Palindromic Repeats Code Complement Complex Conflict (Psychology)Data Dominant-Negative Mutation End stage renal failure Enzyme-Linked Immunosorbent Assay Exhibits FDA approved Family Family health status Fluorescence Functional disorder GC gene Genes Genetic Genetic Transcription Genetic study Healthcare Hereditary Disease Human Investigation Kidney Kidney Diseases Kidney Failure Knowledge Larva Lead Libraries Linkage Disequilibrium Meta-Analysis Methods Modeling Molecular Genetics Monitor Names Other Genetics Outcome Pathogenicity Pathology Pathway interactions Patients Phenotype Physiological Predisposition Proteinuria Renal function Reporting Reproducibility Research Infrastructure Risk Risk Factors Role Series Sickle Cell Sickle Cell Anemia Signal Transduction Stress Susceptibility Gene Testing Therapeutic Therapeutic Intervention Transcript Transgenic Organisms Validation Variant Vascular Endothelial Cell Zebrafish base cell type cellular pathology cohort deep sequencing differential expression effective therapy genetic risk factor genetic variant genome wide association study in vivo in vivo Model loss of function multidisciplinary mutant next generation sequencing novel novel therapeutics podocyte risk variant small molecule spatiotemporal targeted treatment tool transcriptome sequencing transcriptomics translational study

项目摘要

ABSTRACT Sickle cell disease (SCD) is a genetic disorder with profound consequences to families and the health care infrastructure. Notably, SCD can trigger nephropathy leading to end-stage renal disease (ESRD) with poor outcomes and no effective treatment. SCD-dependent susceptibility to ESRD is influenced by genetic factors. We demonstrated previously that MYH9 and APOL1, two loci in close physical proximity on chromosome 22, are independent predictors of proteinuria in SCD. This region, particularly two major risk alleles (named G1 and G2), has been replicated widely in non-SCD nephropathy. However, conflicting studies have suggested that alleles in either APOL1 or MYH9 might contribute to the pathology through an as yet unclear mechanism. Recently, we employed in vivo studies to understand the contribution of this locus to ESRD. We discovered a role for APOL1 in the developing zebrafish kidney and uncovered a complex genetic architecture, wherein the APOL1 G1 risk allele is a functional null while the G2 risk allele exerts a dominant negative effect. Critically, we also found that APOL1 and MYH9 interact genetically, in the context of anemic stress, potentially reconciling diverse observations about the roles of each gene in ESRD. These advances afford us the opportunity to probe key questions in the field, including: the spatiotemporal context involved in the pathology; the underlying cellular mechanisms and pathways that could be targeted for therapeutic intervention; and the extent to which other genetic factors contribute the SCD nephropathy. Equipped with potent, multidisciplinary working tools, including zebrafish mutants that recapitulate an experimentally tractable, physiologically relevant in vivo pathology, we propose three Aims. First, to examine the cellular pathology of the APOL1/MYH9 locus we will investigate the altered transcriptional networks in multiple relevant cell types in our APOL1 zebrafish models. Through this method, we will be able to query both suggested pathways, such as autophagy and altered chloride channel functionality and discover new ones in an unbiased fashion. Second, the absence of mechanistic knowledge in SCD nephropathy has limited therapeutic options. Although angiotensin-converting enzyme inhibitors (ACEi) appear to reduce albuminuria and are used widely, their efficacy in the context of APOL1 and SCD nephropathies remains unproven. We will screen our relevant APOL1 in vivo models for FDA-approved lead therapeutic compounds that could be transitioned rapidly into the clinical arena. Finally, although APOL1 and MYH9 convey critical risk for SCD nephropathy, there is clear evidence for additional genetic risk factors, the identification of which will likely inform pathomechanism. We will leverage our large SCD nephropathy cohort and our in vivo tools to identify additional susceptibility loci and, thus, provide potentially orthogonal entry points into the biology of this phenotype. Taken together, our studies will inform the pathomechanism underpinned by the MYH9/APOL1 locus, identify new drivers for SCD nephropathy and offer an exciting opportunity to identify lead compounds that will have both investigative and therapeutic potential.

抽象的镰状细胞病 (SCD) 是一种遗传性疾病，对家庭和医疗保健产生深远影响基础设施。值得注意的是，SCD 可引发肾病，导致终末期肾病 (ESRD) 结果且无有效治疗。 SCD 依赖性 ESRD 易感性受遗传因素影响。我们之前证明了 MYH9 和 APOL1 这两个位点在 22 号染色体上物理上非常接近，是 SCD 蛋白尿的独立预测因子。该区域，特别是两个主要风险等位基因（名为 G1 和 G2)，已在非 SCD 肾病中广泛复制。然而，相互矛盾的研究表明 APOL1 或 MYH9 中的等位基因可能通过尚不清楚的机制促成病理学。最近，我们采用体内研究来了解该基因座对 ESRD 的贡献。我们发现了一个 APOL1 在发育中的斑马鱼肾脏中的作用，并揭示了一个复杂的遗传结构，其中 APOL1 G1 风险等位基因是功能无效的，而 G2 风险等位基因则发挥显性负面影响。关键的是，我们还发现，在贫血应激的情况下，APOL1 和 MYH9 在遗传上相互作用，可能会调和关于 ESRD 中每个基因的作用的不同观察。这些进步使我们有机会探讨该领域的关键问题，包括：病理学涉及的时空背景；底层的可作为治疗干预目标的细胞机制和途径；以及程度其他遗传因素也会导致 SCD 肾病。配备强大的多学科工作工具，包括斑马鱼突变体，它们重现了实验上易于处理、生理相关的体内病理学方面，我们提出三个目标。首先，为了检查 APOL1/MYH9 基因座的细胞病理学，我们将研究我们的 APOL1 斑马鱼模型中多种相关细胞类型的转录网络的改变。通过这种方法，我们将能够查询两种建议的途径，例如自噬和改变氯离子通道功能并以公正的方式发现新功能。二、缺席 SCD 肾病的机制知识限制了治疗选择。虽然血管紧张素转换酶抑制剂（ACEi）似乎可以减少蛋白尿并被广泛使用，其在以下情况下的功效 APOL1 和 SCD 肾病尚未得到证实。我们将筛选相关的 APOL1 体内模型 FDA 批准的先导治疗化合物可以迅速进入临床领域。最后，尽管 APOL1 和 MYH9 会带来 SCD 肾病的严重风险，但有明确的证据表明需要额外的遗传风险因素，其识别可能会为病理机制提供信息。我们将利用我们庞大的 SCD 肾病队列和我们的体内工具可识别其他易感位点，从而提供该表型生物学的潜在正交切入点。总而言之，我们的研究将为以 MYH9/APOL1 基因座为基础的病理机制，确定 SCD 肾病的新驱动因素并提供这是一个令人兴奋的机会来识别具有研究和治疗潜力的先导化合物。