Abstract: PO1517
Characterization of Porcine Models of Autosomal Recessive Polycystic Kidney Disease
Session Information
- Cystic Kidney Diseases: Mechanisms, Genetics, and Treatment
October 22, 2020 | Location: On-Demand
Abstract Time: 10:00 AM - 12:00 PM
Category: Genetic Diseases of the Kidneys
- 1001 Genetic Diseases of the Kidneys: Cystic
Authors
- Smith, Jessica M., Mayo Clinic Minnesota, Rochester, Minnesota, United States
- Coutts, Alexander Wynn, Recombinetics, St Paul, Minnesota, United States
- Tschida, Barbara Ryan, Recombinetics, St Paul, Minnesota, United States
- Wells, Harrison H., Mayo Clinic Minnesota, Rochester, Minnesota, United States
- Carlson, Daniel F., Recombinetics, St Paul, Minnesota, United States
- Harris, Peter C., Mayo Clinic Minnesota, Rochester, Minnesota, United States
Background
Autosomal recessive polycystic kidney disease (ARPKD), a relatively common form of mainly infantile PKD, is caused by biallelic mutations to PKHD1. The missense change, p.T36M, is the most common pathogenic allele (~15% of the total) and associated with severe disease. Mouse and rat models do not display the classical ARPKD presentation of early onset, enlarged, echogenic kidneys. Therefore, to better understand the pathomechanism, we developed and characterized porcine ARPKD models. The pig has a similar anatomy (multi-papillary structure) and physiology to humans, and thus it makes an ideal model system to study disease progression and test treatment options in this disorder.
Methods
Using the CRISPR/Cas9 methods and homology directed repair (HDR), we genetically engineered pigs with the p.T36M or null PKHD1alleles. The following genotypes were breed (WT, T36M/T36M, T36M/KO, KO/KO) and characterized longitudinally to 5-months old (where possible) using MRI and a blood chemistry panel, and analyzed histologically.
Results
Two KO/KO pigs were sacrificed at one and two days of age with a phenotype of greatly enlarged cystic kidneys with severe functional loss as well as fibrotic, cystic livers, matching classical human ARPKD. Four T36M/KO pigs were imaged monthly to five months but they only developed a few kidney cysts that did not grow significantly during follow up, and without a decline in function. Similar analysis of two T36M/T36M pigs revealed only occasional kidney cysts.
Conclusion
Through gene editing, an authentic porcine model of early onset ARPKD kidney and liver disease was developed that will be valuable for understanding the pathomechanism of neonatal ARPKD. MRI and biochemical assays enabled detailed evaluation of functional and morphological changes in the kidneys, liver, and heart of the milder genotypes. Analysis of the p.T36M allele indicates it more functional in pigs, and so associated with a milder phenotype than in humans.