Abstract: FR-PO611
Role of Ankyrin Repeat and Single KH Domain 1 in Autosomal Dominant Polycystic Kidney Disease Pathogenesis and CyclinD1/CDK4-Induced Proliferation
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
- Terzenidou, Maria-Eirini, Queen Mary University of London Faculty of Medicine and Dentistry, London, London, United Kingdom
- Macleod, Fiona, Queen Mary University of London Faculty of Medicine and Dentistry, London, London, United Kingdom
- Fragiadaki, Maria, Queen Mary University of London Faculty of Medicine and Dentistry, London, London, United Kingdom
Background
Autosomal dominant polycystic kidney disease (ADPKD) is the most common genetic cause of renal failure worldwide. It is a multisystem and progressive disease presenting with renal cyst formation, kidney enlargement, and extrarenal organ involvement. ADPKD involves mutations in PKD1, which encodes for polycystin-1 (PC1), and accounts for 85% of ADPKD cases, and PKD2, which encodes for polycystin-2 (PC2), and contributes to 15% of cases. PC1 and PC2 play a crucial role in controlling cell proliferation, while mutations in these proteins lead to uncontrolled proliferation, is a driver of ADPKD. The only clinically approved medicine for ADPKD, Tolvaptan, has limited use due to its high cost and adverse effects, e.g. liver failure.
It is crucial to develop new therapeutic approaches. Ankyrin Repeat and single KH Domain 1 (ANKHD1) is a cancer-associated protein, which drives uncontrolled cellular proliferation and growth and has never been studied in ADPKD previously. We report that ANKHD1 drives excessive proliferation in mouse and human models of ADPKD.
Methods
We used immunostaining and advanced microscopy along with Western blotting. We performed our experiments in mouse models of ADPKD and patient-derived cell lines.
Results
In this study, we find that ANKHD1 protein levels are elevated in human and murine models of ADPKD and localise in cyst-lining cells. ANKHD1 knockdown in human ADPKD-derived epithelial cells or knockout of ANKHD1 in mouse tissues results in reduced proliferation, slower cystic growth in vitro and smaller kidneys in vivo; critically leading to improved renal function. To gain mechanistic insight we coupled RNA-seq with RNA immunoprecipitation (RIP)-seq, revealing that ANKHD1 controls the CDK4/cyclin D1 axis by binding to CDK4 mRNA. ANKHD1 mediates enhancement of CyclinD1/CDK4 activity via increased retinoblastoma phosphorylation (pRB). This is a p19-dependent and p53/p21-independent mechanism.
Conclusion
Taken together, we find a novel key role for ANKHD1 in ADPKD as a regulator of Cyclin D1/CDK4 cell cycle activity and proliferation, which in the context of ADPKD contributes to disease progression.
Funding
- Government Support – Non-U.S.