NPHP-related polycystic kidney disease in man and mice

我们最近的证明，同源基因突变导致小鼠和人类的囊性肾病，现在提供了一个独特的机会来研究发病机制和治疗。我们已经证明，NPHP3的隐性亚型突变可导致儿童和成人的囊性肾病（青少年肾病），而更严重的NPHP3突变可导致致命的先天性疾病（异位）和/或肾-肝-胰发育不良综合征。同样，我们证明了小鼠的同源突变导致类似的肾脏表型。我们总结了这些不同的肾脏疾病，并建立了三种不同的小鼠模型，这些模型具有稳定的表型表达：1)亚形态Nphp3pcy/pcy突变小鼠（成年发病）；ii) Nphp3ko/ko缺陷小鼠（先天性疾病）；iii)复合突变型Nphp3ko/pcy小鼠（早期发病）。此外，我们还有助于理解NPHP蛋白在纤毛基部起守门人的作用。现在我们将利用我们的小鼠模型和患者材料来破译NPHP蛋白在细胞水平上的特定功能。为此，我们将使用免疫电镜和高分辨率中频技术研究纤毛门处的NPHP蛋白网络，并使用透射电镜和冷冻断裂电镜分析NPHP突变对纤毛项链和y型连接器的超微结构的功能后果。此外，我们将分析突变体纤毛和控制纤毛，以确定人类和小鼠中哪些纤毛蛋白受到NPHP门功能改变的影响。

Our recent demonstration, that mutations of orthologous genes result in cystic kidney disease in mice and man, gives now a unique opportunity to study pathogenesis and therapy. We have shown that recessive hypomorphic mutations of NPHP3 cause cystic kidney disease (adolescent nephronophthisis) in children and adults, whereas more severe NPHP3 mutations result in either lethal congenital disease (heterotaxia) and/or renal-hepaticpancreatic dysplasia syndrome. Likewise we demonstrated that orthologous mutations in mice result in similar renal phenotypes. We recapitulated these distinct renal disorders and generated three distinct mouse models with stable expression of phenotypes: i) hypomorphic Nphp3pcy/pcy mutant mice (adult onset); ii) Nphp3ko/ko deficient mice (congenital disease); iii) compound mutant Nphp3ko/pcy mice (early onset). In addition we have contributed to the understanding that NPHP proteins function as gatekeepers at the ciliary base. Now we will utilize our mouse models as well as patient material to decipher the specific function of NPHP proteins on the cellular level. For that purpose we will perform immuno- EM and high resolution IF to study the NPHP protein network at the ciliary gate and analyze the functional sequelae of NPHP mutations for the ultrastructure of the ciliary necklace as well as the y-connectors using transmission and freeze fracture EM. In addition we will analyze in mutant and control cilia to determine which ciliary proteins are affected by altered NPHP gate function in man and mice.