Abstract: FR-PO622
Deletion of the Homeobox Gene Cux1 Decreases Ciliogenesis in a Mouse Model of Polycystic Kidney Disease
Session Information
- Cystic Kidney Diseases: Mechanisms and Models
October 25, 2024 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Genetic Diseases of the Kidneys
- 1201 Genetic Diseases of the Kidneys: Cystic
Authors
- Vanden Heuvel, Greg, Western Michigan University Homer Stryker MD School of Medicine, Kalamazoo, Michigan, United States
- Wee, Zhi Nee, Western Michigan University Homer Stryker MD School of Medicine, Kalamazoo, Michigan, United States
- Bailey, Kristi L., Western Michigan University Homer Stryker MD School of Medicine, Kalamazoo, Michigan, United States
Background
Autosomal Dominant Polycystic Kidney Disease (ADPKD) is one of the most common inherited disorders affecting the kidney. Renal cyst development in ADPKD results from mutations in the PKD1 or PKD2 genes, which encode the proteins polycstin1 (PC1) and polycystin2 (PC2). PC1 and PC2 proteins are localized to primary cilia where they are proposed to form a receptor channel complex that detects flow transmitting a calcium-mediated signal. Primary cilia are critical to the pathogenesis of ADPKD, which is one of many ciliopathies that exhibit renal cystic disease. Cux1 is a cell cycle dependent transcriptional repressor that regulates the cyclin kinase inhibitor p27. Cux1 is highly and ectopically expressed in mice carrying a collecting duct (CD) specific mutation of Pkd1 (Pkd1 knockout) and in human ADPKD cells. Mice carrying mutations in both Cux1 and Pkd1 have reduced cystic disease and an increased life span.
Methods
To begin to determine whether Cux1 regulates ciliogenesis we evaluated cilia morphology and the expression of the ciliary proteins OFD1, Ptch1, and Ift122 in kidneys isolated from Pkd1 knockout and Pkd1/Cux1 double knock out mice. Cilia morphology was assessed by immunofluorescence labeling of alpha- tubulin, a major component of cilia, and the collecting duct marker dolichos biflorus agglutinin (DBA) to identify cells in which Pkd1 was deleted.
Results
Cilia in Pkd1/Cux1 double knockout kidneys were significantly shorter than cilia in the Pkd1 knockout kidneys alone, consistent with previous studies showing that decreased cilia length corresponds to decreased cystic disease. In addition, expression of OFD1, an inhibitor of cilia formation was significantly increased in Pkd1/Cux1 double knockout kidneys compared to Pkd1 knockout kidneys alone.
Conclusion
Taken together, our results suggest a novel role for Cux1 in regulating ciliogenesis in polycystic kidney disease.