Abstract: SA-OR14
Downregulation of O-GlcNAc Reduces Ciliary Length and Attenuates Renal Cystic Disease in PKD Mice
Session Information
- Genetics, Development, and Therapies
November 05, 2022 | Location: W308, Orange County Convention Center‚ West Building
Abstract Time: 04:57 PM - 05:06 PM
Category: Genetic Diseases of the Kidneys
- 1101 Genetic Diseases of the Kidneys: Cystic
Authors
- Kavanaugh, Matthew A., University of Kansas Medical Center Department of Anatomy and Cell Biology, Kansas City, Kansas, United States
- Wang, Wei, University of Kansas Medical Center Department of Anatomy and Cell Biology, Kansas City, Kansas, United States
- Wang, Henry, University of Kansas Medical Center Department of Anatomy and Cell Biology, Kansas City, Kansas, United States
- Hufft-Martinez, Brittany M., University of Kansas Medical Center Department of Anatomy and Cell Biology, Kansas City, Kansas, United States
- Slawson, Chad, The Jared Grantham Kidney Institutue, Kansas City, Kansas, United States
- Parnell, Stephen C., The Jared Grantham Kidney Institutue, Kansas City, Kansas, United States
- Wallace, Darren P., The Jared Grantham Kidney Institutue, Kansas City, Kansas, United States
- Tran, Pamela Vivian, University of Kansas Medical Center Department of Anatomy and Cell Biology, Kansas City, Kansas, United States
Background
Renal cysts occur in both ciliopathies and mitochondrial diseases, and primary cilia and cellular metabolism are important modifiers of autosomal dominant polycystic kidney disease (ADPKD). The nutrient sensor, O-linked b-N-acetylglucosamine (O-GlcNAc), regulates mitochondrial function as well as ciliary homeostasis. Thus, we hypothesized that O-GlcNAc signaling is misregulated in ADPKD and contributes to renal cystogenesis.
Methods
Immunostaining and Western blot analysis were performed to examine O-GlcNAc levels in mouse and human ADPKD tissues. Using the HoxB7-Cre in mice, Pkd1 was deleted in collecting ducts, alone and together with O-GlcNAc transferase (Ogt), which transfers O-GlcNAc onto protein substrates. Mouse kidneys were analyzed on postnatal days 14 and 21. ADPKD patient cells were treated with pharmacological inhibitors of OGT and ciliogenesis, and effects on cilia lengths and in vitro cyst formation were examined. Co-immunoprecipitation in mouse renal tissue was performed to determine endogenous targets of OGT.
Results
O-GlcNAc levels were elevated in mouse and human ADPKD renal cyst-lining cells compared to normal tissues. Ogt deletion in juvenile Pkd1 conditional knock-out mice reduced ciliary length, renal cystogenesis and kidney weight/body weight, improved kidney function, and increased survival of the mice. Similarly, OGT inhibition in cultured ADPKD patient renal epithelial cells shortened primary cilia and reduced in vitro cyst formation. Additionally, combined treatment of ADPKD cells with OGT and ciliogenesis inhibitors reduced cyst formation to a greater extent than treatment with either inhibitor alone. Co-immunoprecipitation data revealed that OGT interacts with intraflagellar transport protein IFT81, which is important for cilia synthesis and maintenance.
Conclusion
O-GlcNAc is elevated in ADPKD kidneys, and its downregulation reduces ciliary length and renal cystogenesis. OGT binds to IFT81, which may present a novel mechanism of ciliary length control. We propose that O-GlcNAc links the metabolic and ciliary defects in ADPKD and may present new avenues for designing therapeutic strategies.
Funding
- Other U.S. Government Support