Exogenous glycosaminoglycans coat damaged bladder surfaces in experimentally damaged mouse bladder

Restoring the barrier of chronically damaged urothelium using chondroitin sulfate glycosaminoglycan-replenishment therapy

PURPOSE OF REVIEW

This study aims to further understand the physiological mechanism of chondroitin sulfate treatment on the urinary bladder in cases of inflammation, by investigating the effect of chondroitin sulfate therapy on recovery of urothelial barrier in an in-vitro chronic injury model.

RECENT FINDINGS

With inflammatory bladder conditions, the urothelial barrier seems decreased. Glycosaminoglycan (GAG) replacement therapy is supposed to help restore this barrier. Clinical studies on inflammatory bladder conditions are complicated because of the heterogeneous patient population, hence the need for preclinical models.

SUMMARY

In a model using porcine urothelial cells, functional barrier (TEER) and barrier markers were assessed. Chronic urothelial damage was simulated through protamine sulfate instillations with and without subsequent chondroitin sulfate instillations during 3 days. Chondroitin sulfate instillations significantly improved TEER compared to protamine sulfate treatment only (TEER difference 310 Ω.cm 2 , P  < 0.001). This consistent effect over 3 days resulted in a significant higher mean TEER value in the chondroitin sulfate treated group (difference 1855 Ω.cm 2 , P  < 0.001). Enhanced recovery of chondroitin sulfate and other barrier markers was observed.Chondroitin sulfate therapy shows promise in facilitating the recovery of the urothelial barrier in cases of chronic damage. This preclinical study lends support to the use of clinical GAG replenishment therapy for patients with a chronically impaired urothelium.

The urothelial barrier in interstitial cystitis/bladder pain syndrome: its form and function, an overview of preclinical models

PURPOSE OF REVIEW

Investigating bladder pain syndrome/interstitial cystitis (IC/BPS) preclinically is challenging. Various research models have been used to mimic the urothelial barrier closely and replicate the disease. The aim of this review is to discuss preclinical research related to the urothelial barrier in context of IC/BPS.

RECENT FINDINGS

In vivo models mimic IC/BPS mainly with toxic substances in the urine, with protaminesulfate and proteoglycan deglycolysation resembling a temporary impaired barrier as seen in IC/BPS. This temporary increased permeability has also been found in vitro models. Glycosaminoglycan replenishment therapy has been described, in vivo and in vitro, to protect and enhance recover properties of the urothelium. The roles of immune and neurogenic factors in the pathogenesis of IC/BPS remains relatively understudied.

SUMMARY

Preclinical studies provide opportunities to identify the involvement of specific pathologic pathways in IC/BPS. For further research is warranted to elucidate the primary or secondary role of permeability, together with inflammatory and neurogenic causes of the disease.

MRI as a Tool to Assess Interstitial Cystitis Associated Bladder and Brain Pathologies

Interstitial cystitis/bladder pain syndrome (IC/BPS) is a chronic, often incapacitating condition characterized by pain seeming to originate in the bladder in conjunction with lower urinary tract symptoms of frequency and urgency, and consists of a wide range of clinical phenotypes with diverse etiologies. There are currently no diagnostic tests for IC/BPS. Magnetic resonance imaging (MRI) is a relatively new tool to assess IC/BPS. There are several methodologies that can be applied to assess either bladder wall or brain-associated alterations in tissue morphology and/or pain. IC/BPS is commonly associated with bladder wall hyperpermeability (BWH), particularly in severe cases. Our group developed a contrast-enhanced magnetic resonance imaging (CE-MRI) approach to assess BWH in preclinical models for IC/BPS, as well as for a pilot study for IC/BPS patients. We have also used the CE-MRI approach to assess possible therapies to alleviate the BWH in preclinical models for IC/BPS, which will hopefully pave the way for future clinical trials. In addition, we have used molecular-targeted MRI (mt-MRI) to quantitatively assess BWH biomarkers. Biomarkers, such as claudin-2, may be important to assess and determine the severity of BWH, as well as to assess therapeutic efficacy. Others have also used other MRI approaches to assess the bladder wall structural alterations with diffusion-weighted imaging (DWI), by measuring changes in the apparent diffusion coefficient (ADC), diffusion tensor imaging (DTI), as well as using functional MRI (fMRI) to assess pain and morphological MRI or DWI to assess anatomical or structural changes in the brains of patients with IC/BPS. It would be beneficial if MRI-based diagnostic tests could be routinely used for these patients and possibly used to assess potential therapeutics.

Effect of Glycosaminoglycan Replacement on Markers of Interstitial Cystitis In Vitro

Aims: To examine the effect of three commercial intravesical formulations of glycosaminoglycan on in vitro inflammatory models of IC/BPS to better understand there effect on specific markers of disease.

Methods: Human urothelial cells (HTB-4) were cultured under four conditions in the presence or absence of commercial GAG formulations. Cells were cultured under a basal condition or pre-treated with protamine sulfate (100 ng/ml) (damages the endogenous glycosaminoglycan layer), hydrogen peroxide (1%) (a metabolic stressor) or TNFα (10 ng/ml) (creating an inflammatory environment). Each of these four culture conditions was then treated with one of three GAG formulations, CystistatⓇ, iAluRilⓇ and HyacystⓇ. Assays were then performed to examine the effect of the exogenous GAGs on cell viability, cell migration, sGAG production, cytokine and gene expression.

Results: All GAG formulations were well tolerated by the HTB-4 cells and supported cell growth and migration. iAluRilⓇ was most effective at stimulating endogenous sGAG production under all conditions, increasing sGAGs by up to 15-fold. All GAG formulations significantly reduced the production of the pro-inflammatory cytokine IL-8 under basal conditions, while no GAG treatment suppressed cytokine production under any other condition. Only Cystistat^Ⓡ had a significant effect on HA receptor expression, significantly increasing ICAM-1 expression at 3 h that returned to basal levels at 24 h. No GAG treatment significantly changed the expression of GAG synthesis enzymes (CSGALNACT1, CSGALNACT2) or markers of tissue remodeling (MMP2, TIMP1) and pain (COX-1/PTGS-1, NGF).

Conclusions: The data presented in this study reveal that commercial intravesical formulation support cell viability and migration. In addition, the commercial GAG formulations have a mild anti-inflammatory effect in the in vitro model of interstitial cystitis/bladder pain syndrome.

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.

Effect of twice-daily oral administration of a chondroitin sulfate-containing supplement on urine chondroitin sulfate concentrations in dogs

OBJECTIVE

To quantify the magnitude and duration of changes in urine chondroitin sulfate concentration (uCS) as a result of oral administration of a chondroitin sulfate-containing supplement in dogs.

ANIMALS

8 healthy privately owned dogs.

PROCEDURES

A urine sample was collected from each dog via cystocentesis on day 1; free-catch midstream urine samples were collected once daily on days 2 through 5. Pretreatment uCS was established from those samples. Each dog then received a chondroitin sulfate-containing supplement (20 to 30 mg/kg, PO, q 12 h) for 8 days (on days 7 through 14). Urine samples were collected on days 8 through 12 and day 15. For each sample, uCS was quantified by liquid chromatography-tandem mass spectrometry. Variable urine concentration was accounted for by dividing the uCS by urine creatinine concentration (uCrea) to determine the uCS:uCrea ratio. Pretreatment uCS:uCrea ratios were compared with treatment uCS:uCrea ratios to calculate the fold change in uCS after supplement administration.

RESULTS

Among the study dogs, oral administration of the chondroitin sulfate-containing supplement resulted in a 1.9-fold increase in the median uCS:uCrea ratio. Data obtained on days 8 through 12 and day 15 indicated that the daily increase in uCS remained consistent and was not additive.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicated that oral administration of supplemental chondroitin sulfate to dogs modestly increased uCS within 24 hours; however, subsequent supplement administration did not have an additive effect. A potential therapeutic benefit of persistently increased uCS in preventing recurrent urinary tract infections in dogs warrants investigation.

GAG replenishment therapy for bladder pain syndrome/interstitial cystitis

AIMS

To present a rationale for the inclusion of urothelial coating dysfunction in the etipathogenesis of bladder pain syndrome/interstitial cystitis (BPS/IC) and the preclinical and clinical evidence in support of glycosaminoglycan (GAG) replenishment therapy in the treatment of BPS/IC, supplemented by the clinical experience of medical experts in the field and patient advocates attending a symposium on GAG replenishment at ESSIC'17, the annual Meeting of the International Society for the Study of Bladder Pain Syndrome, held in Budapest, Hungary in 2017.

RESULTS

The urothelial GAG layer has a primary role in providing a permeability barrier to prevent penetration of urinary toxins and pathogens into the bladder wall. Disruption of the GAG layer contributes to the development of BPS/IC. The evidence shows that replenishment of GAGs can restore the GAG layer in BPS/IC, reducing inflammation, pain, and other symptoms.

CONCLUSIONS

Although data from large randomized controlled studies are limited, long clinical observation and the experience of clinicians and patients support the beneficial effects of intravesical GAG replenishment therapy for providing symptomatic relief for patients with BPS/IC.

ls clinical practice aligned with the latest scientific evidence on GAG therapy?

The role of glycosaminoglycans (GAGs) as key components of the protective bladder barrier is well accepted. Replenishment of the GAG layer could restore the normal protective barrier function of the damaged bladder urothelium and re-establish normal permeability. A number of bladder diseases, including interstitial cystitis/bladder pain syndrome, recurrent urinary tract infections, radiation cystitis, and other forms of cystitis may benefit from GAG therapy.

Intravesical Glycosaminoglycan Replacement with Chondroitin Sulphate (Gepan(®) instill) in Patients with Chronic Radiotherapy- or Chemotherapy-Associated Cystitis

Background and Objective

Intravesical instillation of glycosaminoglycans is a promising option for the treatment of chronic cystitis, as it supports the regeneration of the damaged urothelial layer. We investigated the efficacy of short-term intravesical chondroitin sulphate treatment (six courses of instillation) in patients with chronic radiotherapy- or chemotherapy-associated cystitis.

Methods

This prospective, observational study included patients with chronic radiotherapy- or chemotherapy-associated cystitis, who received six once-weekly intravesical instillations of 0.2 % chondroitin sulphate 40 mL. Every week, patients recorded their symptoms and their benefits and tolerance of treatment, using a self-completed questionnaire.

Results

The study included 16 patients (mean age 68.5 years; 50 % male). During the study, a reduction in all evaluated parameters was observed. After one dose of chondroitin sulphate, symptom improvement was observed in 38 % of patients, and after the second dose, an additional 31 % of patients showed improvement. At week 6, 80 % of patients had either improved or were symptom free, and significant improvements in urinary urgency (p = 0.0082), pollakisuria (p = 0.0022), urge frequency (p = 0.0033) and lower abdominal pain (p = 0.0449) were observed. Haematuria, present in 9 of the 16 patients at baseline, was completely resolved in all cases after 6 weeks. The majority of patients (93 %) evaluated the tolerance of chondroitin sulphate as ‘good’ or ‘very good’. No treatment-related adverse events were reported.

Conclusion

Intravesical administration of chondroitin sulphate was effective for the treatment of radiotherapy- or chemotherapy-associated cystitis. Even short-term treatment appears to be effective in reducing symptoms and improving the quality of life of patients.

Glycosaminoglycans: how much do we know about their role in the bladder?

The urothelium is a unique lining in the body providing a protective barrier against the penetration of toxic agents, urine, and bacteria. The glycosaminoglycan (GAG) layer consists of a thick mucus layer of glycoproteins and proteoglycans on the surface of the urothelial cells. Damage to the GAG layer disrupts its protective barrier function giving rise to increased permeability into the deep layers of the urothelium and bladder, causing inflammation and pain. Replenishment of the GAG layer appears to restore normal permeability allowing for urothelial layer recovery.

Current guidelines in the management of interstitial cystitis

Interstitial cystitis (IC) is a heterogeneous chronic disease of unknown etiology that impacts a very large number of women. Symptoms are highly variable: patients may suffer from pelvic pain that is exacerbated by bladder filling, and can be associated with a variety of lower urinary tract symptoms including frequency and urgency. Given the varying presentations and severities of corresponding treatment must be tailored to each specific patient. Current American Urological Association (AUA) guidelines separate the IC treatment recommendations into six tiers of increasing invasive therapies. These treatment guidelines begin with education and lifestyle modifications and progress through levels of physical, pharmacological, and ultimately surgical therapies for those that fail the less invasive therapies. The purpose of this review is to outline the recommendations for the treatment of IC and the evidence from which these recommendations arise. Furthermore, we examine the most up to date literature so that we may recognize future directions in the treatment of IC.

Intravesical hyaluronic acid treatment improves bacterial cystitis and reduces cystitis-induced hypercontractility in rats

OBJECTIVE

To investigate the effect of intravesical hyaluronic acid on Escherichia coli-induced cystitis and cystitis-induced hypercontractility in rats.

METHODS

Bacterial cystitis was induced in Wistar female rats by intravesical inoculation of E. coli. Isotonic saline was instilled in the control group (n = 6). The rats were either non-treated, treated with gentamycin (4 mg/kg, 5 days) or treated intravesically with hyaluronic acid (0.5 mL, 0.5%). On the eighth day, the bladder tissues were excised for histological examination, and the measurements of myeloperoxidase, superoxide dismutase and catalase activities. Contraction/relaxation responses to carbachol, isoprotrenol and papaverine were studied.

RESULTS

Tissue myeloperoxidase activity was increased, but superoxide dismutase and catalase activities were decreased in bacterial cystitis, while hyaluronic acid treatment reversed these changes. In the hyaluronic acid-treated group, healing of the uroepithelium was observed, while decreased inflammatory cell infiltration was obvious in gentamycin-treated group. E. coli-induced cystitis in all rats resulted in increased contraction responses to carbachol compared with controls (P < 0.01). Treatment with hyaluronic acid, but not gentamycin, significantly (P < 0.05) depressed hypercontractility at maximum carbachol concentrations. In all rats with cystitis, papaverine-induced relaxation was increased, whereas isoproterenol-induced relaxation curves were not different between the studied groups.

CONCLUSION

Gentamycin treatment, despite its ameliorative effect on inflammation, had no impact on the contractile dysfunction of the injured bladder. Intravesical hyaluronic acid, in addition to its supportive role in the healing of the epithelium, seems to lower the increased threshold for contraction and to reduce oxidative stress. These findings support a potential role for hyaluronic acid in the treatment of bacterial cystitis.

Current recommendations for bladder instillation therapy in the treatment of interstitial cystitis/bladder pain syndrome

Bladder instillation therapy refers to the direct introduction of medication into the bladder and is a common treatment modality for patients with interstitial cystitis/bladder pain syndrome (IC/BPS) who have failed conservative and oral therapies. The current American Urological Association (AUA) recommendations list three medications as options for IC/BPS instillation therapy: dimethyl sulfoxide, heparin, and lidocaine. The purpose of this review is to examine the evidence behind the recommendations for these medications. We also examine several historical or experimental therapies that do not hold recommendations but are still used on rare occasion. Finally, we discuss our bladder instillation strategies as well as potential future research and development in intravesicular therapy.

Effects of exogenous glycosaminoglycans on the histological structure of the rat bladder in experimental cystitis

The protective effects of a complex glycosaminoglycan preparation in doses of 50 and 100 mg/kg were studied in experimental cystitis induced in rats by administration of 9% acetic acid. Daily glycosaminoglycan intake for 2 weeks before intrabladder injection of acetic acid resulted in a less severe injury to the bladder mucosa in comparison with controls receiving no glycosaminoglycans.

GAG layer replenishment therapy for chronic forms of cystitis with intravesical glycosaminoglycans--a review

AIMS

Glycosaminoglycan (GAG) layer replenishment is a cornerstone in the therapy of interstitial cystitis (IC). During the last years intravesical GAG layer replenishment has proven to be an effective treatment for overactive bladder (OAB), radiation cystitis, and recurrent urinary tract infections (UTIs).

METHODS

Examination of different substances available for intravesical GAG replenishment and evaluation of the evidence for the treatment of the above-mentioned conditions.

RESULTS

We searched the Medical Literature Analysis and Retrieval System Online (MEDLINE) database for studies on intravesical GAG replenishment. A total of 27 clinical studies remain relevant to this topic, many of them with mixed patient selection and suboptimal definition of symptom improvement/success. Two placebo controlled studies with hyaluronic acid failed to show superiority and have not been published. One active controlled randomized study has been published showing that chondroitin sulphate 0.2% has a clear benefit for OAB patients. Another study with chondroitin sulphate 2.0% failed to show statistically significant evidence, but was underpowered.

CONCLUSIONS

A short number of randomized controlled studies confirm efficacy of intravesical GAG layer replenishment therapy. Concluded from the study background (which comprises also uncontrolled studies), so far chondroitin sulphate 0.2% is in favor for intravesical GAG layer replenishment therapy. In general, large-scale trials are urgently needed to underline the benefit of this type of therapy.

Alkalinized lidocaine and heparin provide immediate relief of pain and urgency in patients with interstitial cystitis

INTRODUCTION

It has been reported in an open-label study that the combination of alkalinized lidocaine and heparin can immediately relieve the symptoms of urinary urgency, frequency, and pain associated with interstitial cystitis (IC). This combination has also been reported to relieve pain associated with sex in patients with IC.

AIM

The aim of this study was to corroborate these findings in a multicenter setting.

METHODS

The study design was a multicenter prospective, double-blind, crossover, placebo-controlled trial. Each participant met all of the clinical National Institute of Diabetes and Digestive and Kidney Diseases criteria (excluding cystoscopy) for IC. Each patient received drug and control, in random order, within 48 hours of enrolling in the study.

MAIN OUTCOME MEASURES

The primary outcome measure was percent change in pain score (11-point analog pain scale) 12 hours after receiving the drug or control. Secondary measures were the global assessment response (GAR) of symptoms and 12-hour average urgency reduction determined from 11-point urgency scales.

RESULTS

Eighteen (18) patients completed the trial. The average reduction of pain over 12 hours was 21% for control and 42% for active drug (P = 0.0363). GAR was 13% for control and 50% for drug (P = 0.0137). Average urgency reduction was 13% for control and 35% for drug (P = 0.0328).

CONCLUSIONS

The combination of alkalinized lidocaine and heparin provides up to 12 hours of relief from urgency and pain associated with IC. This combination provides significant immediate relief of symptoms for patients with IC.

Leukotriene D4 receptor antagonist montelukast alleviates protamine sulphate-induced changes in rat urinary bladder

What's known on the subject? and What does the study add? The mastocytosis in detrusor muscle and the leaky epithelium in interstitial cystitis were the most studied features. In this study the leaky epithelium was shown using the ruthenium red staining in electron microscopy and uroplakin distribution in light microscopy besides the mast cell concentration in detrusor muscle using tryptase immunohistochemistry.

OBJECTIVE

• To study the effects of montelukast (ML), a leukotriene receptor antagonist which has been shown to be effective in inhibiting the action of cysteinyl-containing leukotrienes, on protamine sulphate (PS)-induced changes in rat urinary bladder.

MATERIALS AND METHODS

• Wistar female rats were catheterized and intravesically infused with PBS (control group) or PS (PS group) dissolved in PBS twice in 24 h. • In the PS-applied and ML-treated group (PS + ML group) after the 10 mg/kg PS instillation, ML was injected i.p. twice daily for 3 days. • The urinary bladder was investigated for general morphology under a light microscope. • Tryptase immunohistochemistry was used to observe mast cell distribution and activation. Uroplakin distribution was also identified with immunohistochemistry.

RESULTS

• Alterations of glycosaminoglycan (GAG) and urothelial permeability were seen with ruthenium red (RR) staining techniques under a transmission electron microscope, and topographical changes of luminal urothelial structure were seen with a scanning electron microscope. • Biochemically malondialdehyde (MDA) and gluthatione (GSH) concentrations were analysed. In the PS group, there was degenerated urothelium with irregular uroplakin distribution, increased inflammatory cell infiltration, increased number of both granulated and activated mast cells, irregularity of GAG and penetration of RR into the intercellular spaces and dilated tight junctions. • In PS + ML group, there was relatively regular uroplakin distribution, a decrease in inflammatory cell infiltration, a decreased number of both activated and granulated mast cells in the mucosa, regular GAG and no penetration of RR into the intercellular areas, and regular tight junctions in most regions. • The significant decrease in MDA and the increased GSH concentrations in the PS + ML group was in accordance with the histological findings.

CONCLUSION

• Montelukast appears to have a protective function in the bladder injury model via the anti-inflammatory effects of this leukotriene receptor antagonist.

Prophylactic vesical instillations with 0.2% chondroitin sulfate may reduce symptoms of acute radiation cystitis in patients undergoing radiotherapy for gynecological malignancies

Introduction and hypothesis

We studied the feasibility and efficacy of intravesical instillations with 40 ml chondroitin sulfate 0.2% solution to prevent or reduce acute radiation cystitis in women undergoing pelvic radiotherapy.

Methods

In a comparative pilot study in 20 patients, half of the patients received instillations. Instillations' bother was measured with visual analog scores (VAS, 0–10); bladder pain, with VAS; micturition-related quality of life, with the urogenital distress inventory (UDI).

Results

One of the instilled patients discontinued the instillations. The first median “acceptability”-VAS was 0 (range, 0–3); the last median was 1 (range, 0–3). “Bladder pain”-VAS peaked halfway in the treatment among controls (median, 1; range, 0–5) and after treatment in the instilled patients (median, 1; range, 1–3). UDI scores showed over time median follow-up scores at or above median baseline scores in controls and at or below median baseline scores in instilled patients.

Conclusion

Intravesical instillations with chondroitin sulfate 0.2% solution may decrease the bother related to bladder symptoms and are well tolerated.

Restoring barrier function to acid damaged bladder by intravesical chondroitin sulfate

PURPOSE

Chondroitin sulfate (Stellar Pharmaceuticals, London, Ontario, Canada), which is less expensive and more inert than heparinoids, hyaluronan or pentosan polysulfate, has been introduced to restore the barrier function lost due to epithelial dysfunction in interstitial cystitis cases. To our knowledge chondroitin sulfate binding to damaged bladder as a function of the urinary pH range, its efficacy in restoring the bladder permeability barrier and the capacity of the damaged bladder to bind chondroitin sulfate have not been determined previously.

MATERIALS AND METHODS

Chondroitin sulfate binding to bladder urothelium was investigated quantitatively using chondroitin sulfate highly labeled with Texas Red(R) and quantitative fluorescence microscopy in a mouse model of urothelial acid damage. The efficacy of restoring barrier function was determined using the passage of intravesically instilled (86)Rb, a potassium ion mimetic, through the urothelium into the bloodstream in a rat model of bladder damage. The binding capacity of acid damaged bladder was determined by fluorometry.

RESULTS

Chondroitin sulfate bound tightly and exclusively to the mouse bladder surface damaged by acid but showed only minimal binding to undamaged bladder. There was no systematic variation in pH. The model showed some variability in the degree of damage induced. In rats chondroitin sulfate instillation restored permeability to (86)Rb to control levels. Binding was saturable at a mean +/- SEM 0.67 +/- 0.13 mg/cm(2) of the bladder surface.

CONCLUSIONS

Chondroitin sulfate binds preferentially to damaged urothelium and restores the impermeability barrier. This suggests that the glycosaminoglycan layer is a major contributor to bladder urothelial impermeability. As determined by binding capacity, the dose applied in humans in Canada (400 mg per instillation) is sufficient to achieve maximum efficacy.

Chondroitin sulphate: a complex molecule with potential impacts on a wide range of biological systems

Chondroitin sulphate (CS) is widely consumed orally by humans, and non-humans as it is believed to be beneficial for those with joint-related pathologies. Data concerning the functions of chondroitin sulphate in this, and other, biological systems are being actively extended. However, it is important to appreciate that chondroitin sulphate molecules represent a heterogeneous population the structure of which varies with source. As commercially available chondroitin sulphate is derived from a range of sources, and the molecular functions of chondroitin sulphate depend upon the structure, there are a range of structures available with differing potential for therapeutic impacts on a range of pathologies. While the safety of CS is not presently in doubt, poor quality finished products have the potential to compromise clinical and lab-based studies and will fail to give consumers all of the benefits available. Major parameters including bioavailability and uptake have been studied but it is clear that significant challenges remain in the identification of composition, sequence and size impacts on function, understanding how the consumed material is altered during uptake and travels to a site of action and how it exerts an influence on biological processes. If we understand these factors it may be possible to predict impacts upon biological processes and identify specific chondroitin sulphate structures which may target specific pathologies.

Differentiation-induced uroplakin III expression promotes urothelial cell death in response to uropathogenic E. coli

Uropathogenic E. coli (UPEC) expressing type 1 pili underlie most urinary tract infections (UTIs). UPEC adherence to the bladder urothelium induces a rapid apoptosis and exfoliation of terminally differentiated urothelial cells, a critical event in pathogenesis. Of the four major uroplakin proteins that are densely expressed on superficial urothelial cells, UPIa serves as the receptor for type 1-piliated UPEC, but the contributions of uroplakins to cell death are not known. We examined the role of differentiation and uroplakin expression on UPEC-induced cell death. Utilizing in vitro models of urothelial differentiation, we demonstrated induction of tissue-specific differentiation markers including uroplakins. UPEC-induced urothelial cell death was shown to increase with enhanced differentiation but required expression of uroplakin III: infection with an adenovirus encoding uroplakin III significantly increased cell death, while siRNA directed against uroplakin III abolished UPEC-induced cell death. In a murine model of UTI where superficial urothelial cells were selectively eroded to expose less differentiated cells, urothelial apoptosis was reduced, indicating a requirement for differentiation in UPEC-induced apoptosis in vivo. These data suggest that induction of uroplakin III during urothelial differentiation sensitizes cells to UPEC-induced death. Thus, uroplakin III plays a pivotal role in UTI pathogenesis.

Bladder defense molecules, urothelial differentiation, urinary biomarkers, and interstitial cystitis

It has long been recognized that interstitial cystitis (IC) is a disease of the urothelium. In this article, we review the results of published studies and present new data concerning the precise role of the bladder epithelium in IC. We discuss bladder defenses against both the penetration of urinary solutes and bacterial adherence, and we present new information about the proteoglycans that are present on the normal bladder. Previously published results and new data presented here support the conclusion that IC involves an aberrant differentiation program in the bladder urothelium that leads to altered synthesis of several proteoglycans, cell adhesion and tight junction proteins, and bacterial defense molecules such as GP51. These findings lend support to the rationale for glycosaminoglycan replacement therapy for the treatment of patients with IC.

Treatment approaches for painful bladder syndrome/interstitial cystitis

Painful bladder syndrome/interstitial cystitis (PBS/IC) is a disease of unknown aetiology, characterised by severe pressure and pain in the bladder area or lower pelvis that is frequently or typically relieved by voiding, along with urgency or frequency of urination in the absence of urinary tract infections. PBS/IC occurs primarily in women, is increasingly recognised in young adults, and may affect as many as 0.1-1% of adult women. PBS/IC is often comorbid with allergies, endometriosis, fibromyalgia, irritable bowel syndrome and panic syndrome, all of which are worsened by stress. As a result, patients may visit as many as five physicians, including family practitioners, internists, gynaecologists, urologists and pain specialists, leading to confusion and frustration. There is no curative treatment; intravesical dimethyl sulfoxide, as well as oral amitriptyline, pentosan polysulfate and hydroxyzine have variable results, with success more likely when these drugs are given together. Pilot clinical trials suggest that the flavonoid quercetin may be helpful. Lack of early diagnosis and treatment can affect outcomes and leads to the development of hyperalgesia/allodynia.

Local drug delivery to bladder using technology innovations

Local delivery of drugs directly into the bladder by way of a urethral catheter is a clever approach to optimize drug delivery to the disease site while reducing systemic bioavailability. Pharmacotherapy by this route is referred to as intravesical delivery. In recent years, intravesical delivery has been used in combination with and oral regimen of drugs or as second-line treatment for neurogenic bladder and detrusor overactivity. Negligible absorption of instilled drugs into the systemic circulation explains the near-minimal adverse toxicity reported with this form of therapy. The authors discuss shortcomings of the current options available for intravesical delivery and provide a broad overview of the latest advances through technology innovation to overcome these drawbacks.