Kidney Week

Abstract: FR-OR001

Targeting the Cell Cycle in ADPKD: The Role of Cyclin-Dependent Kinase 1

Session Information

• Advances in PKD: From Omics to Therapeutics
  November 08, 2019 | Location: 143, Walter E. Washington Convention Center
  Abstract Time: 04:30 PM - 04:42 PM

Category: Genetic Diseases of the Kidneys

• 1001 Genetic Diseases of the Kidneys: Cystic

Authors

• Pedroso Balbo, Bruno Eduardo, Yale University School of Medicine, New Haven, United States

Bruno Eduardo Pedroso Balbo, MD, PhD

• Zhang, Chao, Yale University School of Medicine, New Haven, Connecticut, United States

Chao Zhang,

• Tian, Xin, Yale School of Medicine, New Haven, Connecticut, United States

Xin Tian,

• Cai, Yiqiang, Yale University School of Medicine, New Haven, Connecticut, United States

Yiqiang Cai,

• Spitzer, Max, Yale University, New Haven, Connecticut, United States

Max Spitzer,

• Gallagher, Rachel, Yale University School of Medicine, New Haven, Connecticut, United States

Rachel Gallagher,

• Dong, Ke, Yale University School of Medicine, New Haven, Connecticut, United States

Ke Dong,

• Somlo, Stefan, Yale University, New Haven, Connecticut, United States

Stefan Somlo,

Background

Cilia ablation reduces cyst formation after polycystin inactivation, suggesting that a cilia-dependent cyst-activating (CDCA) mechanism is a driver in ADPKD. To investigate this pathway, we conducted transcriptomic profiling in adult-onset ADPKD models at an early stage following cyst initiation. We identified cyclin-dependent kinase 1 (Cdk1) as one of the most upregulated genes in incipient cyst cells following Pkd1 inactivation and we investigated its role in ADPKD pathogenesis.

Methods

To enrich for transcriptomes from cells destined to form cysts in the kidney, we isolated RNA by translating ribosome affinity purification (TRAP). RNAseq profiling was performed in 10wk-old mice (4/group): Pkd1^fl/+;R26^Rpl10a;Pax8^rtTA;TetO^Cre (non-cystic; NC), Pkd1^fl/fl;R26^Rpl10a; Pax8^rtTA;TetO^Cre (cystic, single KO; SKO) and Pkd1^fl/fl;Kif3a^fl/fl;R26^Rpl10a;Pax8^rtTA;TetO^Cre (non-cystic Pkd1-cilia double KO; DKO). Differential gene and KEGG pathway analyses were performed.
Mouse models with early- (Pkd1^fl/fl;Pkhd1^Cre) and late-onset Pkd1 deficiency (Pkd1^fl/fl;Pax8^rtTA;TetO^Cre) were combined with the Cdk1-floxed allele, generating single KO (Pkd1-KO) and double KO (Cdk1-Pkd1-KO) models. The early and late onset groups were evaluated respectively on P24 and on the 18^th wk of life (after doxycycline induction from P28-42).

Results

155 genes were identified from the overlap between groups that shared differential expression in both NC vs SKO and SKO vs DKO groups. KEGG pathway analysis identified the cell cycle pathway as the most enriched and upregulated. Cdk1 emerged as one of the most upregulated genes in this group. Polycystic kidney disease in Cdk1-Pkd1-KO group was significantly milder in both early onset and adult models when compared with Pkd1-KO models, as indicated by lower kidneys to body weight ratio, cystic index, and BUN. Cell proliferation rate (EdU incorporation) was significantly decreased in Cre-active tubule segments while no difference in apoptosis (TUNEL) was detected.

Conclusion

TRAP RNAseq on adult-onset ADPKD model at the early cystic stage has identified the cell cycle pathway as the most enriched one, suggesting that cell cycle changes occur early during the cyst formation. Cdk1 emerged as one of the most upregulated cell cycle genes during cyst formation, and inactivation of Cdk1 decreased cyst progression in ADPKD.

Funding

• NIDDK Support