Identifying the earliest events in HIV-1 associated nephropathy via genome-wide

描述（由申请人提供）：本项目的目标是使用经过验证的小鼠模型来解剖介导HIV-1相关肾病（HIVAN）发展的分子途径。HIV-1是HIV-1感染的主要并发症，具有独特的病理特征。这种疾病是由HIV-1诱导肾小球足细胞去分化引起的，肾小球足细胞是维持肾脏滤过屏障结构的终末分化上皮细胞。HIVAN的遗传易感性具有复杂的决定因素，非肌肉肌球蛋白重链9 （MYH9）的遗传变异起着重要作用，MYH9是足细胞表达的基因。具有FVB/NJ遗传背景的HIV-1转基因小鼠概括了HIVAN的所有临床和病理特征。通过对HIVAN易感性对比的小鼠之间的定位队列，我们确定了三个分别位于染色体3、13和4上的肾病易感性位点（命名为HIVAN1- 3），并通过检测捕获这些间隔的同源小鼠确认了定位数据。通过结合F2分离的连锁分析和基因表达谱（eQTL定位），我们还证明了小鼠HIVAN易感位点编码足细胞基因表达的反调节因子，并且与已知的人类肾病基因（Myh9, Podocin, Nephrin, Cd2ap）属于相同的途径。HIV-1的引入导致基因型和特定足细胞基因表达之间关系的显著扰动，表明HIV-1干扰了转调控。这些考虑表明，仔细解剖与每个hiv位点相关的临床和分子表型，以及鉴定在HIV-1暴露时表现出最大的转调控扰动的基因，可以阐明肾病起始的最早事件，并描绘介导疾病发病机制的失调分子网络。为了实现这些目标，我们将首先对HIVAN基因小鼠进行表型表征，以确定每个位点对疾病发生和进展的贡献。接下来，我们将对HIV-1基因转基因小鼠和野生型小鼠的肾小球转录组进行分析，以推断HIVAN中的肾小球相互作用组，并发现表现出异常转调控模式的基因。最后，这些基因将通过在hiv分离株中进行eQTL定位、在人类足细胞中进行功能研究，并最终通过转基因系的产生来证实这些发现。HIVAN分子介质的鉴定有望为了解疾病的发病机制提供重要的见解，并为治疗干预提供新的靶点。

DESCRIPTION (provided by applicant): The goals of this project are to use a validated mouse model to dissect molecular pathways mediating he development of HIV-1 associated nephropathy (HIVAN). HIVAN is a major complication of HIV-1 infection with distinct pathologic features. This disorder is caused by HIV-1 induced dedifferentiation of glomerular podocytes, the terminally differentiated epithelial cells that maintain the structure of the kidney filtration barrier. Genetic susceptibility to HIVAN has complex determination, with significant contribution from genetic variation in the nonmuscle myosin heavy chain 9 (MYH9), a podocyte expressed gene. HIV-1 transgenic mice on the FVB/NJ genetic background recapitulate all the clinical and pathologic hallmarks of HIVAN. Using mapping cohorts between mice with contrasting susceptibility to HIVAN, we have identified three nephropathy susceptibility loci that map to chromosomes 3, 13, 4 respectively (named HIVAN1- 3) and have confirmed mapping data by examination of congenic mice that capture these intervals. By combining linkage analysis with gene expression profiling (eQTL mapping) in F2 segregants, we have also demonstrated that the murine HIVAN susceptibility loci encode transregulators of podocyte gene expression and belong to the same pathway as known human nephropathy genes (Myh9, Podocin, Nephrin, Cd2ap). The introduction of HIV-1 results in significant perturbations of the relationship between genotype and expression of specific sets of podocyte genes, indicating that HIV-1 interferes with transregulation. These considerations indicate that careful dissection of clinical and molecular phenotypes associated with each HIVAN locus and identifications of genes that demonstrate the greatest perturbation in transregulation upon HIV-1 exposure can elucidate the earliest events in the initiation of nephropathy and delineate dysregulated molecular networks mediating disease pathogenesis. To achieve these aims, we will first perform phenotypic characterization of HIVAN congenic mice to identify the contribution of each locus to initiation and progression of disease. Next we will perform analysis of glomerular transcriptome in HIV-1 transgenic congenic mice and wiltype counterparts to infer the glomerular interactome in HIVAN and discover genes that demonstrate aberrant patterns of transregulations. Finally, these genes will be validated by eQTL mapping in HIVAN segregants, by functional studies in human podocytes and ultimately, by generation of transgenic lines that will confirm findings. Identification of molecular mediators of HIVAN is expected to provide significant insight into the pathogenesis of disease and provide novel targets for therapeutic intervention. PUBLIC HEALTH RELEVANCE: HIV-1 associated nephropathy is a major complication of HV-1 infection and a significant cause of kidney failure worldwide. Identification of molecular mediators of HIVAN is expected to provide significant insight into the pathogenesis of disease and provide novel targets for therapeutic intervention.