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Abstract: FR-PO345

Pkd2 Re-Expression Can Reverse Liver Cysts and Improve GFR in Mouse Models of Autosomal Dominant Polycystic Kidney Disease

Session Information

Category: Genetic Diseases of the Kidneys

  • 1101 Genetic Diseases of the Kidneys: Cystic

Authors

  • Dong, Ke, Yale University School of Medicine Department of Internal Medicine, New Haven, Connecticut, United States
  • Tham, Mingshen, Yale University School of Medicine Department of Internal Medicine, New Haven, Connecticut, United States
  • Cordido, Adrian, Yale University School of Medicine Department of Internal Medicine, New Haven, Connecticut, United States
  • Cai, Yiqiang, Yale University School of Medicine Department of Internal Medicine, New Haven, Connecticut, United States
  • Pei, Steven Lim Cho, Yale University School of Medicine Department of Internal Medicine, New Haven, Connecticut, United States
  • Bhardwaj, Rishi, Yale University School of Medicine Department of Internal Medicine, New Haven, Connecticut, United States
  • Wei, Zemeng, Yale University School of Medicine Department of Internal Medicine, New Haven, Connecticut, United States
  • Rehman, Michael, Yale University School of Medicine Department of Internal Medicine, New Haven, Connecticut, United States
  • Roy, Kasturi, Yale University School of Medicine Department of Internal Medicine, New Haven, Connecticut, United States
  • Tian, Xin, Yale University School of Medicine Department of Internal Medicine, New Haven, Connecticut, United States
  • Somlo, Stefan, Yale University School of Medicine Department of Internal Medicine, New Haven, Connecticut, United States
Background

We have previously shown that PKD gene re-expression reverses polycystic kidney disease in inducible, whole nephron Cre mediated mouse models of ADPKD. We now sought to investigate the potential for cyst reversal in the Pkd2WS25 mouse model in which macrocyst formation occurs by stochastic, non-Cre recombinase dependent, second hit events that better resemble the genetic mechanism of human ADPKD and allows determination of the potential to reverse both polycystic kidney and liver phenotypes.

Methods

Pkd2WS25/- and tamoxifen inducible Pkd2-BAC re-expression (Pkd2FSF;Rosa26FlpoER) models previously established in the lab were intercrossed to generate Pkd2WS25/-;Pkd2FSF;Rosa26FlpoER mice (Pkd2WS25/Flpo). Pkd2 re-expression was induced with 7 daily intraperitoneal tamoxifen injections beginning at 16 weeks. Serial kidney MRI were obtained at 16, 19 and 24 weeks and kidney and liver histology was examined at 24 weeks. In addition, we used our published Pkd2Cre/Flpo model with doxycycline induced Pkd2 inactivation at 4-6 weeks and reactivation at 16 weeks to measure serial GFR at 16 and 19 weeks.

Results

Compared to 16-week-old Pkd2WS25/- mice, kidney weight/body weight ratio (1.812% vs 1.333%, P=0.0049), liver weight/body weight ratio (5.299% vs 4.371%, P=0.0198) and kidney cystic index (22.18% vs 7.164%, P=0.0002) were significantly reduced in 24-week-old Pkd2WS25/Flpo mice following Pkd2 reactivation at 16 weeks. Moreover, MRI images shows progressive decrease in kidney cystic burden from 16 to 24 weeks. Kidney and liver histology at 24 weeks showed reduced cystic changes but persistent residual fibrosis and focal inflammation compared to 16-week-old Pkd2WS25/- mice which exhibited multifocal cysts. Separately, Pkd2Cre/Flpo mice which showed reduced GFR at 16 weeks before Pkd2 re-expression, had normalization of GFR at 19 weeks age, 3 weeks after Pkd2 re-expression (0.77 ml/min/100g vs 1.45 ml/min/100g, P=0.0032).

Conclusion

Pkd2 re-expression can reverse both kidney and liver cysts in a spontaneous, non-Cre recombinase dependent Pkd2 model that more closely recapitulates the human ADPKD phenotype with a smaller number of larger macrocysts. Furthermore, our follow-up study to our published data shows that improved GFR accompanies improved histology following Pkd gene re-expression.

Funding

  • NIDDK Support