ASN's Mission

ASN leads the fight to prevent, treat, and cure kidney diseases throughout the world by educating health professionals and scientists, advancing research and innovation, communicating new knowledge, and advocating for the highest quality care for patients.

learn more

Contact ASN

1401 H St, NW, Ste 900, Washington, DC 20005

email@asn-online.org

202-640-4660

The Latest on Twitter

Kidney Week

Abstract: FR-PO735

Diverse Receptor Tyrosine Kinase Phosphorylation in Urine-Derived Immortalized Tubular Epithelial Cells of ADPKD Patients

Session Information

Category: Genetic Diseases of the Kidneys

  • 1001 Genetic Diseases of the Kidneys: Cystic

Authors

  • Ikeda, Kisho, Department of Nephrology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
  • Kusaba, Tetsuro, Kyoto Prefectural University of Medicine, Kyoto-city, Japan
  • Tamagaki, Keiichi, Kyoto Prefectural University of Medicine, Kyoto-city, Japan
  • Uehara, Masahiro, kyoto prefecture university of medicine, KYOTO, Kyoto, Japan
Background

Clinical features of autosomal dominant polycystic kidney disease (ADPKD), including responses to drugs, differ among patients even if they have the same gene mutation in PKD1 or PKD2. This suggests that there is diversity in the expression of other modifier genes or in the underlying molecular mechanisms of ADPKD, but these are not well understood. In this study, we analyzed the diversity in receptor tyrosine kinase (RTK) phosphorylation in tubular epithelial cells of ADPKD patients.

Methods

Urine-derived epithelial cells were primarily cultured, and immortalized cell lines were established by SV40 large T gene transfection. SLC12A3-positive colonies, which is a specific marker of distal tubules, were used for experiments. RTK phosphorylation and its downstream signaling were analyzed in established cell lines. Three-dimensional culture of MDCK cells was used as a cyst formation model of ADPKD.

Results

Comprehensive analysis of RTK phosphorylation in immortalized tubular epithelial cells from 8 ADPKD patients and 4 healthy controls revealed diversity in the activation of several molecules, such as Axl (Gas6 receptor) and Met (HGF receptor), and there were differences even among patients from the same family. Golvatinib, a selective Met inhibitor, or transduction of siRNA for Met suppressed cell proliferation as well as downstream signaling, such as phosphorylation of Akt, only in the cell lines in which hyperphosphorylation of Met was observed. In three-dimensional culture of MDCK cells, HGF activated Met and its downstream signaling, such as Akt or Erk, resulting in an increased total cyst number and total cyst volume. Golvatinib treatment inhibited these phenotypes in MDCK cells.

Conclusion

The analysis of urine-derived tubular epithelial cells demonstrated diverse RTK phosphorylation in ADPKD, and Met phosphorylation was noted in some patients. Given the difference in the effects of golvatinib on immortalized tubular epithelial cells among patients, this analysis may aid in determining suitable drugs for individual ADPKD patients as "precision medicine".