Decreased urothelial cytoskeleton and cell proliferation protein expression suggest interstitial cystitis/bladder pain syndrome patients with Hunner's lesion and grade 3 glomerulation might be different from other types of patients.

OBJECTIVES

To explore the expression of cytoskeletal and cell proliferation proteins in urothelial cells of patients diagnosed with various clinical subtypes of interstitial cystitis/bladder pain syndrome.

METHODS

Biopsy specimens from 85 interstitial cystitis/bladder pain syndrome patients were classified according to findings on cystoscopy. Cytokeratins and cell proliferation proteins detected in the specimens were evaluated with immunofluorescence staining and quantified with western blotting. A total of 22 patients diagnosed with pure stress urinary incontinence were enrolled as controls.

RESULTS

Interstitial cystitis/bladder pain syndrome patients with Hunner's lesion and with grade 3 glomerulation hemorrhage had smaller bladder capacities than the other interstitial cystitis/bladder pain syndrome patients without Hunner's lesion. Diminished expression of CK14, CK20, cell proliferation protein tumor protein 63, sonic hedgehog, and fibroblast growth factor receptors 3 and 4, and increased expression of CK5 and BCL2-associated X protein were observed in biopsy specimens from patients with Hunner's lesion compared with those from patients without Hunner's lesion and controls. In the patients with grade 3 glomerulation hemorrhage, lower expression levels of urothelial CK20, tumor protein 63 and fibroblast growth factor receptor 4, and lower expression of CK5 and BCL2-associated X protein were detected compared with other types of NHIC.

CONCLUSION

A diminished expression of proliferation proteins tumor protein 63 and the mature urothelium marker CK20, and increased expression of the immature marker CK5 in specimens from both Hunner's lesion and grade 3 glomerulation hemorrhage patients can be observed. The urothelium of patients with interstitial cystitis/bladder pain syndrome might be in a state of persistent or chronic injury that could relate to the limited expression of cell proliferation proteins.