Abstract 19664: Molecular Mechanisms of Gα12 Regulated E-cadherin Shedding in Epithelial Cells
Introduction and hypothesis: E-cadherin plays an important role in maintaining the integrity of cell polarity and cell junctions. It is one of the major proteins that forms part of the polycystin-1 (PC1) complex in renal epithelial cells. We previously showed that deletion of the PC1-regulated protein, Gα12, protected kidneys from development of kidney cysts induced by Pkd1 inactivation and activation of Gα12 increased the shedding of E-cadherin in autosomal dominant polycystic kidney disease (ADPKD). The objective of this study was to determine the molecular mechanisms by which Gα12 regulates E-cadherin shedding.
Methods: We analyzed polycystic kidneys from human and from Pkd1 knock-out mice. Using Madin-Darby canine kidney (MDCK) cells, we developed a Pkd1 deletion in vitro model using Pkd1 siRNA.
Results: Our data shows that Pkd1 deletion caused accumulation of cleaved E-cadherin fragment in renal cystic fluid in both human polycystic kidneys and in our mice model. In addition, we found that activation of Gα12 increased the active form of ADAM10, the cleavage protein for E-cadherin in both human and mice polycystic kidneys, in vivo. In our MDCK cellular three-dimensional culture system, Gα12 activation promoted cyst formation and this phenomenon was inhibited by ADAM10 knockdown. Furthermore, knockdown of ADAM10 abolished the shedding of E-cadherin caused by Gα12 activation. These data indicate that ADAM10 is the major sheddase for cleavage of E-cadherin caused by Gα12 activation.
Conclusion: Our results demonstrate that Gα12 activation increases ADAM10 activity and promotes the ectodomain shedding of E-cadherin, which is an important mechanism in the development of kidney cysts induced by Pkd1 deletion in ADPKD.
Author Disclosures: J. Xu: None. Y. Wu: None. S. Li: None. K. Lim: Employment; Significant; Oregon Health and Science University. Research Grant; Significant; Early Clinical Investigator (ECI) Grant, Medical Research Foundation (MRF). T. Kong: Employment; Significant; Brigham and Women’s Hospital. Research Grant; Significant; NIH/NIDDK. T. Lu: Employment; Significant; Brigham and Women’s Hospital. Research Grant; Significant; Brigham and Women’s Hospital Research Sundry fund.
- © 2014 by American Heart Association, Inc.