DACH1 transcriptomic regulation of glucocorticoid-responsive glomerular disease

DACH1 糖皮质激素反应性肾小球疾病的转录组调控

• 批准号: 10338127
• 负责人: Lewis Kaufman
• 金额: $ 37.29万
• 依托单位: ICAHN SCHOOL OF MEDICINE AT MOUNT SINAI
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-03-12 至 2025-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10338127
• 关键词: Adriamycin PFS; Alleles; Benefits and Risks; Binding; Binding Proteins; Binding Sites; Cell Line; Clinical; Data; Disease; Enhancers; Event; Focal Segmental Glomerulosclerosis; Genes; Genetic; Genetic Polymorphism; Genetic Transcription; Genotype; Glucocorticoid Receptor; Glucocorticoids; Goals; Human; In Vitro; Injury; Kidney Diseases; Kidney Transplantation; Knockout Mice; Link; Mediating; Mus; Mutation; Nephrology; Nephrotic Syndrome; Outcome; Patients; Phenotype; Predisposition; Proteinuria; Regulation; Renal glomerular disease; Reporter; Resistance; Signal Transduction; Single Nucleotide Polymorphism; Stratification; Susceptibility Gene; Testing; Therapeutic; Toxic effect; Transgenic Mice; Transplant Recipients; Up-Regulation; Work; chromatin immunoprecipitation; cohort; design; genome wide association study; immunoregulation; in vivo; induced pluripotent stem cell; mouse model; novel; novel therapeutic intervention; overexpression; patient subsets; podocyte; preservation; promoter; protective allele; receptor binding; resistance allele; response; risk variant; systemic toxicity; targeted treatment; transcription factor; transcriptome; transcriptomics; treatment choice

Project Summary: Podocyte injury is the causative event in all proteinuric kidney diseases including minimal change disease (MCD) and FSGS. Glucocorticoids (GCs) are often the initial and preferred treatment for these conditions. The beneficial effects of GCs are not caused by immunomodulation, but are mediated by their direct effects on podocytes. Unfortunately, GC therapy is riddled with severe systemic toxicities that limit their use. Identification of essential salutary GC-induced targets in podocytes might allow for new therapeutic approaches that can minimize toxicity but maintain efficacy. In the current proposal, we identified diminished expression of the transcription factor dachshund1 (DACH1) in a large-scale mutagenic screen designed to identify mutations that restored injury susceptibility to genetically injury-resistant podocytes. We found DACH1 to be essential to podocyte function in both novel global and podocyte-specific knock out mouse models. Importantly, podocyte- specific DACH1 heterozygous mice, which have reduced glomerular DACH1 expression levels similar to human MCD and FSGS patients, were remarkably susceptible to adriamycin nephropathy, and this phenotype was ameliorated by GC therapy. We found that GC administration caused early and significant induction of DACH1 expression, and we confirm binding of GC receptor to the DACH1 promoter by ChIP assay. Moreover, the protective allele of a DACH1 intronic SNP (rs626277), which has been identified in genome-wide association studies as linked to incident and prevalent CKD, introduced a GC-alpha transcription factor-binding site that was abrogated in the presence of the risk allele. When we tested these alleles in reporter studies, the protective allele dramatically augmented DACH1 promoter activity in response to GCs, consistent with GC- potentiated enhancer function. In GC treated kidney transplant patients, the protective rs626277 allele correlated closely with increased glomerular DACH1 expression and improvement in proteinuria. Furthermore, in a cohort of MCD and FSGS patients, protective and risk alleles correlated with GC responsiveness and resistance respectively. We hypothesize that DACH1 is a central transcriptomic regulator of the salutary glomerular GC response and that rs626277 genotype status, which modulates podocyte DACH1 transcription in the setting of GC therapy, is an important determinant of GC-responsiveness in nephrotic syndrome patients. Our proposal includes three specific aims: i) demonstrate that DACH1 over-expression is protective using a novel inducible podocyte-specific DACH1 transgenic mouse model ii) show that the beneficial effects of GCs in podocytes are mitigated in the absence of DACH1 expression using novel inducible podocyte-specific knockout mice iii) correlate rs626277 genotype status with clinical outcomes in GC-treated MCD and FSGS patients in NEPTUNE and cross-examine mechanistic and transcriptomic data obtained from the first two aims in these patients. If validated, rs626277 genotype status could serve to individualize risk-benefit stratification of GC therapy in nephrotic syndrome patients PRIOR to treatment initiation.

项目摘要： 足细胞损伤是所有蛋白尿肾脏疾病（包括最小变化疾病）的病因事件 （MCD）和FSG。糖皮质激素（GC）通常是这些条件的初始和首选治疗方法。这 GC的有益作用不是由免疫调节引起的，而是由它们的直接影响介导的 足细胞。不幸的是，GC疗法充满了严重的全身毒性，这些毒性限制了它们的使用。鉴别 基本有益的GC诱导的足细胞中的靶标可能允许新的治疗方法 最小化毒性但保持功效。在当前的建议中，我们确定了 在大规模诱变屏幕中的转录因子Dachshund1（Dach1）旨在识别突变 恢复了损伤对遗传损伤的足细胞的敏感性。我们发现Dach1对于 新型全局和足细胞特异性敲除小鼠模型中的足细胞功能。重要的是，足细胞 - 特定的DACH1杂合小鼠，它们降低了肾小球DACH1表达水平类似 人MCD和FSGS患者非常容易受到adrimycin肾病的影响，并且这种表型 通过GC治疗改善。我们发现，GC给药引起了早期和显着的诱导 DACH1表达，我们通过CHIP测定法证实GC受体与DACH1启动子的结合。而且， DACH1内含子SNP（RS626277）的保护性等位基因已在全基因组中鉴定出来 与事件和普遍CKD相关的关联研究引入了GC-Alpha转录因子结合 在存在风险等位基因的情况下被废除的地点。当我们在记者研究中测试这些等位基因时 保护性等位基因响应GC急剧增强的DACH1启动子活性，与GC-一致 增强增强子功能。在GC治疗的肾脏移植患者中，保护性RS626277等位基因 与肾小球DACH1表达增加和蛋白尿的改善密切相关。此外， 在MCD和FSGS患者的队列中，保护性和风险等位基因与GC反应性相关 电阻分别。我们假设DACH1是有益的中央转录组调节剂 肾小球GC响应和RS626277基因型状态，该状态调节Podocyte Dach1转录 在GC治疗的情况下，是肾病综合征GC响应性的重要决定因素 患者。我们的建议包括三个具体目标：i）证明DACH1过表达是保护性的 使用新型的诱导型足细胞特异性DACH1转基因小鼠模型II）表明， 在不使用DACH1表达的情况下，使用新型的诱导型足细胞特异性来减轻足细胞中的GC。 敲除小鼠iii）将RS626277基因型状态与GC处理的MCD和FSG中的临床结果相关联 从前两个目的获得的海王星和盘问机械和转录组数据的患者 在这些患者中。如果经过验证，RS626277基因型状态可能有助于个性化风险效益分层 在治疗开始之前，肾病综合征患者的GC治疗。