Kidney Week

Abstract: TH-PO584

ADAM10-MMP14 Complex Regulates Renal Cystogenesis in Autosomal Dominant Polycystic Kidney Disease

Session Information

• Cystic Kidney Diseases - I
  November 02, 2017 | Location: Hall H, Morial Convention Center
  Abstract Time: 10:00 AM - 10:00 AM

Category: Genetic Diseases of the Kidney

• 801 Cystic Kidney Diseases

Authors

• Xu, Frank, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States

Frank Xu,

• Ho, Li-lun, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States

Li-lun Ho,

• Denker, Bradley M., Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States

Bradley M. Denker,

• Kong, Tianqing, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States

Tianqing Kong,

• Bonventre, Joseph V., Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States

Joseph V. Bonventre,

• Lu, Tzongshi, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States

Tzongshi Lu,

Background

Autosomal dominant polycystic kidney disease (ADPKD) is associated with mutations in polycystins, alterations in cell-cell junctions and focal adhesions in renal epithelial cells. Polycystin 1 (PC1) forms a large protein complex that includes E-cadherin and Gα12 binding proteins that play key roles to maintain cell-cell junctions and cell polarity. We previously reported that deletion of PC1-regulated protein, Gα12, protected kidneys from kidney cystogenesis induced by Pkd1 inactivation, and activation of Gα12 increased the shedding of E-cadherin. However, signaling pathways of PC1 induced ADPKD are not fully understood.

Methods

We used Madin-Darby canine kidney (MDCK) cells, Pkd1 deletion renal cells and Pkd1 knockout mice kidney tissue. Inducible Pkd1 knockout mice were generated by flanking exons 2 through 6 with two LoxP sites (Mx1Cre+; Pkd1flox/flox). Double knockout of Pkd1 and Gα12 mice were obtained by crossing Mx1Cre⁺Pkd1^flox/flox mice with Gα12^-/- mice (Pkd1-/-Gα12-/-) . MDCK Tet-off inducible Gα12 and Gα12QL cell lines were used in 3D cell culture.

Results

The conditional deletion of Pkd1 (Pkd1^-/-) resulted in multiple kidney cysts forming within 9 weeks, but Pkd1-/-Gα12-/- mice had no structural and functional abnormalities in the kidneys. Pkd1 deletion promoted increased E-cadherin fragments in renal cystic fluid. No change in cyst E-cadherin fragments in Gα12^-/- mice. Gα12 increased the active form of ADAM10, and knockdown of ADAM10 blocked the Gα12 mediated E-cadherin shedding. Our data indicate that ADAM10 is the major sheddase for cleavage of E-cadherin caused by Gα12 activation. Increased ADAM10/MMP14 complex promotes cystogenesis in renal epithelial cells. ADAM10 activity is dependent on the catalytic and hemopexin domains of MMP14. Inhibition of ADAM10 and MMP14 activity blocks cystogenesis induced by Gα12 activation. The deletion of Pkd1 increases the activation of Gα12, which subsequently decreases cell-matrix and cell-cell adhesion by affecting focal adhesion and E-cadherin cleavage.

Conclusion

Gα12 is an essential downstream signaling molecule for PC1, and Gα12 activation increases ADAM10 activity promoting the ectodomain shedding of E-cadherin that plays a key role in renal cystogenesis in Pkd1 deletion induced ADPKD. The ADAM10-MMP14-Ecadherin axis is a potential therapeutic target for ADPKD.

Funding

• Private Foundation Support