Department of Dermatology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA.
Physiol Genomics. 2013 Aug 15;45(16):720-8. doi: 10.1152/physiolgenomics.00089.2013. Epub 2013 Jun 18.
Many lines of evidence demonstrate that genetic variability contributes to chronic kidney disease susceptibility in humans as well as rodent models. Little progress has been made in discovering causal kidney disease genes in humans mainly due to genetic complexity. Here, we use a minimal congenic mapping strategy in the FHH (fawn hooded hypertensive) rat to identify Sorcs1 as a novel renal disease candidate gene. We investigated the hypothesis that genetic variation in Sorcs1 influences renal disease susceptibility in both rat and human. Sorcs1 is expressed in the kidney, and knocking out this gene in a rat strain with a sensitized genome background produced increased proteinuria. In vitro knockdown of Sorcs1 in proximal tubule cells impaired protein trafficking, suggesting a mechanism for the observed proteinuria in the FHH rat. Since Sorcs1 influences renal function in the rat, we went on to test this gene in humans. We identified associations between single nucleotide polymorphisms in SORCS1 and renal function in large cohorts of European and African ancestry. The experimental data from the rat combined with association results from different ethnic groups indicates a role for SORCS1 in maintaining proper renal function.
大量证据表明,遗传变异性不仅会导致人类慢性肾病,也会导致啮齿动物模型的慢性肾病。由于遗传复杂性,人类在发现导致肾脏疾病的基因方面几乎没有取得进展。在这里,我们使用 FHH(fawn hooded hypertensive)大鼠的最小同基因作图策略来鉴定 Sorcs1 作为一种新的肾脏疾病候选基因。我们研究了遗传变异 Sorcs1 是否会影响大鼠和人类的肾脏疾病易感性的假设。Sorcs1 在肾脏中表达,在具有敏感基因组背景的大鼠品系中敲除该基因会导致蛋白尿增加。体外敲低近端肾小管细胞中的 Sorcs1 会损害蛋白质运输,这表明 Sorcs1 在 FHH 大鼠中观察到的蛋白尿的一种机制。由于 Sorcs1 会影响大鼠的肾功能,我们继续在人类中测试该基因。我们在欧洲和非洲裔人群的大型队列中鉴定了 SORCS1 单核苷酸多态性与肾功能之间的关联。大鼠的实验数据和来自不同种族群体的关联结果表明 SORCS1 在维持正常肾功能方面起着重要作用。