Cdk1/p53/p21 feedback loop mechanisms in the pathogenesis of interstitial cystitis/bladder pain syndrome

Purpose: This study aimed to elucidate the role of the CDK1/p53/p21 feedback loop in the pathogenesis of interstitial cystitis (IC)/bladder pain syndrome (BPS).

Materials and methods: An IC/BPS cell model was established. Cell viability was determined using the CCK-8 assay. Flow cytometry was adopted to assess cell Apoptosis rates. ELISA was employed to measure secretion levels of inflammatory factors (IL-6, IL-8, and TNF-α). Gene expressions were assessed using PCR, while protein expressions were analyzed through Western blotting analysis. Epithelial permeability was demonstrated using the phenol red leakage experiment and FITC-dextran permeability assay. The interaction between proteins was determined using co-immunoprecipitation, and protein localization was investigated using immunofluorescence.

Results: The CCK-8 assay revealed a significantly reduced viability of IC/BPS cells compared to normal epithelial cells (p < 0.05). Elevated levels of IL-6, IL-8, and TNF-α were detected in IC/BPS cells. Changes in the expressions of E-cadherin and ZO-1 were evident, leading to increased epithelial permeability in IC/BPS cells. Furthermore, within IC/BPS cells, CDK1 phosphorylated p53 in the nucleus. The CDK1/p53/p21 feedback loop was established to influence urothelial permeability. Both p21 and CDK1 inhibitors notably reduced the epithelial permeability in IC/BPS cells.

Conclusion: The CDK1/p53/p21 feedback loop was instrumental in IC/BPS, acting as a regulator of urothelial permeability. This discovery offered a novel therapeutic approach for IC/BPS management.

Cdk1; Feedback loop; IC/BPS; Urothelial permeability; p53/p21.