Zhu Jun-Yi, Fu Yulong, Richman Adam, Zhao Zhanzheng, Ray Patricio E, Han Zhe
Centers for Cancer and Immunology Research and.
Department of Nephrology, First Affiliated Hospital of Zhengzhou University, Zhengzhou, China; and.
J Am Soc Nephrol. 2017 Sep;28(9):2607-2617. doi: 10.1681/ASN.2016060626. Epub 2017 Apr 20.
Clinical studies have identified patients with nephrotic syndrome caused by mutations in genes involved in the biosynthesis of coenzyme Q (CoQ), a lipid component of the mitochondrial electron transport chain and an important antioxidant. However, the cellular mechanisms through which these mutations induce podocyte injury remain obscure. Here, we exploited the striking similarities between nephrocytes and human podocytes to develop a model of these renal diseases, and performed a systematic analysis assessing the role of CoQ pathway genes in renal function. Nephrocyte-specific silencing of , , and , which are genes involved in the CoQ pathway that have been associated with genetic nephrotic syndrome in humans, induced dramatic adverse changes in these cells. In particular, silencing of led to an abnormal localization of slit diaphragms, collapse of lacunar channels, and more dysmorphic mitochondria. In addition, -deficient nephrocytes showed elevated levels of autophagy and mitophagy, increased levels of reactive oxygen species, and increased sensitivity to oxidative stress. Dietary supplementation with CoQ at least partially rescued these defects. Furthermore, expressing the wild-type human gene specifically in nephrocytes rescued the defective protein uptake, but expressing the mutant allele derived from a patient with nephropathy did not. We conclude that transgenic lines carrying mutations in the CoQ pathway genes are clinically relevant models with which to explore the pathogenesis of podocyte injury and could serve as a new platform to test novel therapeutic approaches.
临床研究已鉴定出由参与辅酶Q(CoQ)生物合成的基因突变引起的肾病综合征患者,辅酶Q是线粒体电子传递链的脂质成分和重要的抗氧化剂。然而,这些突变诱导足细胞损伤的细胞机制仍不清楚。在这里,我们利用肾细胞与人类足细胞之间的显著相似性来建立这些肾脏疾病的模型,并进行了系统分析,以评估CoQ途径基因在肾功能中的作用。对CoQ途径中与人类遗传性肾病相关的基因、和进行肾细胞特异性沉默,会在这些细胞中引起显著的不良变化。特别是,的沉默导致裂孔隔膜异常定位、腔隙通道塌陷以及线粒体形态异常。此外,缺乏的肾细胞显示出自噬和线粒体自噬水平升高、活性氧水平增加以及对氧化应激的敏感性增加。饮食中补充CoQ至少部分挽救了这些缺陷。此外,在肾细胞中特异性表达野生型人类基因挽救了有缺陷的蛋白质摄取,但表达来自肾病患者的突变等位基因则没有。我们得出结论,携带CoQ途径基因突变的转基因品系是探索足细胞损伤发病机制的临床相关模型,可作为测试新治疗方法的新平台。