The role of DNA damage response signaling in chronic kidney disease

摘要 DNA损伤反应信号在慢性肾脏疾病中的作用肾结核（NPHP）是 一种常染色体隐性遗传慢性肾病（CKD），特征为肾小管间质纤维化、肾小管 基底膜破裂和肾囊肿。肾纤维化是终末期肾病的主要决定因素 肾脏疾病，目前尚无有效的治疗方法。最近的研究表明，NPHP是一种 "纤毛病"，由基因突变引起，其蛋白质定位于中心体和/或初级纤毛， 并产生了一个统一的NPHP-related ciliopathies（NPHP-RC）的致病性概念。尽管 在超过30个基因的突变鉴定为NPHP-RC的病因，很少有人知道的分子 疾病的潜在机制。最近，通过全外显子组重测序，我参与了 3个新基因CEP164、FAN1和SDCCAG8与肾性NPHP-RC相关性研究 变性/纤维化。令人惊讶的是，中心体蛋白CEP164和SDCCAG 8也被表达。 定位于细胞核，其失活导致DNA损伤反应（DDR）信号转导受损 伴随着细胞周期缺陷。因此，与已知的DNA损伤修复蛋白FAN 1一起， CEP164和SDCCAG 8暗示缺陷DDR信号传导是NPHP-RC的新病理机制。 我推测NPHP-RC中的肾变性/纤维化是由DNA损伤反应缺陷引起的 途径。为了验证这一假设，我将（1）检查“纤毛蛋白”在调节DNA中的作用， 使用Cep164和Sdccag8肾纤维化小鼠模型的损伤反应途径;（2）进行 高通量筛选影响和抵消NPHP-RC的小分子 研究CEP164和SDCCAG8的功能和调控机制 它们在中心体和核中的双重定位之间的差异。完成拟议的研究 将提供（1）对纤毛病病理机制的新见解;（2）新的化合物， 导致NPHP-RC和肾纤维化的治疗;（3）研究DDR相关疾病的新动物模型。 本K99/R00申请的目的是利用新生成的动物模型研究 NPHP-RC的分子机制。这将有助于我的研究生涯向一个 独立调查员职位。该奖项的培训（K99）阶段将由Friedhelm博士指导 Hildebrandt是霍华德休斯医学研究所的研究员，也是国际公认的 人类遗传学和小儿肾脏疾病领域。2013年3月，我将搬到波士顿。 儿童医院（BCH）/哈佛医学院（HMS）与Hildebrandt博士的实验室。我的长期 我的职业目标是成为肾脏研究领域的独立研究者，专注于 肾脏疾病的动物模型。BCH/HMS有几个合作研究小组， 肾脏发育和疾病为我的培训和职业发展提供了理想的环境。

ABSTRACT The role of DNA damage response signaling in chronic kidney disease. Nephronophthisis (NPHP) is an autosomal recessive chronic kidney disease (CKD), characterized by tubulointerstitial fibrosis, tubular basement membrane disruption and kidney cysts. Renal fibrosis is the primary determinant of end-stage kidney disease, with no effective therapy available today. Recent work has identified NPHP as a “ciliopathy”, caused by mutations in genes, whose proteins localize to the centrosome and/or primary cilium, and has generated a unifying pathogenic concept for NPHP-related ciliopathies (NPHP-RC). Despite the identification of mutations in more than 30 genes as causative of NPHP-RC, little is known about the molecular mechanisms underlying the disease. Recently, by whole exome resequencing I was involved in the identification of 3 novel genes – CEP164, FAN1 and SDCCAG8 as causing NPHP-RC with renal degeneration/fibrosis when mutated. Surprisingly, the centrosomal proteins CEP164 and SDCCAG8 were also localized at cell nuclei, and their inactivation led to impaired DNA damage response (DDR) signaling accompanied by cell cycle defects. Hence, together with FAN1, which is a known DNA damage repair protein, CEP164 and SDCCAG8 implicate defective DDR signaling as a novel pathomechanism of NPHP-RC. I hypothesize that renal degeneration/fibrosis in NPHP-RC is caused by defects in DNA damage response pathways. To test this hypothesis, I will (1) examine the role of “ciliopathy proteins” in regulating the DNA damage response pathway using the Cep164 and Sdccag8 mouse models of renal fibrosis; (2) perform a high-throughput screen for small molecules that influence and counteract the NPHP-RC pathogenesis; (3) characterize the functions and regulation of trafficking of CEP164 and SDCCAG8 between their dual localizations at centrosomes and in nuclei. Accomplishment of the proposed research will provide (1) new insights into the pathomechanisms of ciliopathies; (2) new chemical compounds that can lead to therapies for NPHP-RC and renal fibrosis; (3) new animal models for studying DDR-related diseases. The objective of this K99/R00 application is to utilize the newly generated animal models for the study of molecular mechanisms of NPHP-RC. This will facilitate the transition of my research career towards an independent investigator position. The training (K99) phase of this award will be mentored by Dr. Friedhelm Hildebrandt, who is an investigator of Howard Hughes Medical Institute and internationally recognized leader in the fields of human genetics and of pediatric kidney diseases. In March 2013 I will move to the Boston Children's Hospital (BCH)/Harvard Medical School (HMS) with Dr. Hildebrandt's laboratory. My long-term career goal is to establish myself as an independent investigator in the field of kidney research, focusing on animal models of kidney diseases. The BCH/HMS has several collaborative research groups working on kidney development and diseases providing an ideal environment for my training and career development.