A Deficit of Proteoglycans on the Bladder Uroepithelium in Interstitial Cystitis

Improving the barrier function of damaged cultured urothelium using chondroitin sulfate

AIMS

To determine whether glycosaminoglycan (GAG) replenishment is able to improve recovery of a deficient urothelial barrier, chondroitin sulfate (CS) instillations were tested using an in vitro model. Porcine urothelial cells (Ucells) were terminally differentiated in culture conditions to construct a urothelial layer with a functional barrier. This layer was damaged to compromise barrier function to simulate a key characteristic of bladder pain syndrome/interstitial cystitis. The functional effect of subsequent treatment with CS was evaluated.

METHODS

Primary porcine Ucells were isolated and cultured on inserts. Differentiation of cells was evaluated with immunohistochemical analysis for the presence of umbrella cells, tight junctions and CS. Transepithelial electrical resistance (TEER) measurements were performed to evaluate barrier function. Protamine was used to simulate mild urothelial damage. CS 0.2% (vol/vol), a GAG, was subsequently instilled in the treatment group. The recovery of barrier function was further evaluated with TEER measurements. The Student t test was used for the analysis of results.

RESULTS

After induction of differentiation, the Ucells expressed barrier markers and a functional barrier was established (measured by high TEER). TEER decreased significantly after instillation with protamine. CS instillation improved recovery of TEER significantly measured after 7 hours (84% vs 22% in controls). After 24 hours; however, the TEER was comparable in both experimental groups.

CONCLUSION

CS instillation improves the recovery of the urothelial barrier after damage in vitro. This functional experiment shows that CS improves recovery of damaged urothelial function, which supports the hypothesis behind the mechanism of action of GAG-replenishment therapy.

Long-term experience with sodium chondroitin sulfate in patients with painful bladder syndrome

OBJECTIVE

To assess the response of patients diagnosed with painful bladder syndrome to treatment with instillations of sodium chondroitin sulfate.

MATERIAL AND METHODS

We present a series of cases of patients with painful bladder syndrome who followed a bladder instillation protocol with sodium chondroitin sulfate, according to our centre's regimen. The response to treatment was assessed with respect to pain, according to the Downie scale; urinary frequency, according to the voiding diary; and subjective improvement, according to the Patient Global Impression of Improvement (PGI-I) scale.

RESULTS

A total of 28 patients with a median age of 59 years (range 22-90) followed this protocol. From the medical histories, 19.4% had suffered an infection of the urinary tract, 3.8% had suffered urinary tuberculosis, 7.6% received pelvic radiation therapy and 26.9% had taken anticholinergic drugs for overactive bladder syndrome. We evaluated the response to treatment at 0, 3, 6 and 12 months and found that at the end of treatment 72.3% of the patients had improved bladder pain and 75% were significantly better.

CONCLUSIONS

Treatment with sodium chondroitin sulfate through endovesical instillation in painful bladder syndrome improves pain, voiding frequency and quality of life in the long term.