Establishment of animal models for pharmaceutical experiment in polycystic kidney disease (PKD)

常染色体显性遗传性多囊肾病（autosomaldominantpolycystickiddisease，ADPKD）是人类最常见的遗传性肾脏病，其PKD 1或PKD 2基因均发生突变。本研究拟以小鼠和青鳉鱼为实验动物，建立多囊性肾病的药物实验动物模型。首先，将Pkd 1基因敲除的异种小鼠（Pkd 1 ^<+/->）与端粒酶缺陷小鼠进行杂交。由于基因组的不稳定性，端粒缩短会导致频繁的体细胞突变。虽然与Pkd 1 ^<+/->/Terc ^<+/->（hetero）小鼠相比，Pkd 1 ^<+/->/Terc^<+/->（homo）小鼠似乎存在早期囊肿形成，但在我们的实验中并没有产生类似人类ADPKD的多囊性肾。除获得EF-1α启动子（EF-1α-A-EGFP-pkd 2 ΔC）转基因株外，还将转录因子rtTA（EF-1α-A-tTA）和青鳉Pkd 2基因缺失突变株与Tet-on载体交配，获得Tet-On EGFP-pkd 2 ΔC转基因株。在EF-1α启动子菌株的肾脏中观察到不同数量的囊肿。此外，四个月后Tet-On菌株显示多囊肾类似于人类ADPKD。这些结果表明青鳉Pkd 2基因的缺失突变体以显性负抑制的方式抑制内源Pkd 2基因。在未来，我们希望此转基因青鳉可以作为多囊肾疾病药物实验的动物模型。

Autosomal dominant polycystic kidney disease (ADPKD) is a most common human hereditary renal disease mutated in either PKD1 or PKD2 gene. We planned to generate animal models for pharmaceutical experiment in polycystic kidney disease using mice and small fish, medaka.First, Pkd1 knockout hetero mice (Pkd1^<+/->) were intercrossed with telomerase-deficiency mice. Telomere shortening could lead frequent somatic mutation because of genome instability. Although early cystogenesis seemed to be indicated in Pkd1^<+/->/Terc^<+/-> (homo) mice compared to Pkd1^<+/->/Terc^<+/-> (hetero) mice, polycystic kidneys like human ADPKD were not generated in our experiment.Second, we generated transgenic medaka carrying a deletion mutant of medaka Pkd2 cDNA. Beside the transgenic strain with EF-1α promotor (EF-1α-A-EGFP-pkd2ΔC) strains, other strain (Tet-On EGFP-pkd2ΔC strain) was obtained by mating one strain of transcriptional factor rtTA (EF-1α-A-tTA) and one strain of the deletion mutant of medaka Pkd2 gene with Tet-on vector. Various number of cysts were observed in the kidneys of EF-1α promotor strains. Furthermore, Tet-On strains after four months revealed polycystic kidneys resembled to human ADPKD. These results suggest that a deletion mutant of medaka Pkd2 gene inhibit intrinsic Pkd2 gene in a dominant-negative manner. In the future, we hope that this transgenic medaka could be an animal model for pharmaceutical experiment in polycystic kidney disease.