TRPV4 activation prevents lipopolysaccharide-induced painful bladder hypersensitivity in rats by regulating immune pathways.

Chronic inflammation in the urinary bladder is a potential risk factor for bladder dysfunction, including interstitial cystitis/bladder pain syndrome (IC/BPS). Although several studies have reported that activation of transient receptor potential vanilloid 4 (TRPV4) contributes to bladder pain and overactive bladder with a cardinal symptom of acute or chronic cystitis, others have reported its involvement in the protective response mediated by lipopolysaccharides (LPS) to secrete anti-inflammatory/pro-resolution cytokines. Therefore, we investigated the potential benefit of an intravesical TRPV4 agonist for painful bladder hypersensitivity in a rat model of LPS-induced cystitis and determined whether its effects modulate the LPS signal for inflammatory reaction, cytokine release, and macrophage phenotype change. Previously, we showed that repeated intravesical instillations of LPS induce long-lasting bladder inflammation, pain, and overactivity in rats. In the present study, concurrent instillation of the selective TRPV4 agonist GSK1016790A (GSK) with LPS into the rat bladder improved LPS-induced bladder inflammation and reduced the number of mast cells. Furthermore, co-instillation of GSK prevented an increase in bladder pain-related behavior and voiding frequency caused by LPS. Cytokine profiling showed that LPS-stimulated inflammatory events, such as the production and secretion of pro-inflammatory cytokines (CXCL1, CXCL5, CXCL9, CXCL10, CCL3, CCL5, CCL20, and CX3CL1), are suppressed by GSK. Furthermore, TRPV4 activation switched LPS-stimulated pro-inflammatory M1-type macrophages to anti-inflammatory M2-type macrophages. These results suggest that TRPV4 activation in the bladder negatively regulates the pro-inflammatory response induced by LPS and prevents bladder hypersensitivity. These TRPV4 functions may be promising therapeutic targets for refractory IC/BPS.

Human Umbilical Cord Mesenchymal Stem Cell Therapy Mitigates Interstitial Cystitis by Inhibiting Mast Cells.

BACKGROUND Interstitial cystitis (IC) is a recurrent and chronic inflammatory disease that compromises patients' quality of life. Effective treatments for IC are limited. This study aimed to evaluate the therapeutic potency of human umbilical cord-derived mesenchymal stem cells (UC-MSCs) in an IC-induced rat model and investigate the potential molecular mechanism in a mast cell model (rat basophilic leukemia cells, RBL-2H3) in treating IC in a coculture system. MATERIAL AND METHODS The rat model of IC was induced by cyclophosphamide (CYP). Rats were randomly divided into 3 groups: sham, IC+PBS, and IC+MSC. In the coculture system, RBL-2H3 cells were sensitized overnight to Compound 48/80 (C48/80), cocultured with UC-MSCs for 3 days, and collected for subsequent experiments. RBL-2H3 cells were randomly divided into 3 groups: sham, C48, and UC-MSCs (C48+MSC). RESULTS The UC-MSCs marked by thymidine analog 5-ethynyl-2-deoxyuridine (EdU) were transplanted in the treatment group, and were densely distributed in the bladder. Accordingly, the conscious cystometry was measured and the bladder tissues were harvested. Compared with the sham group, the treated IC rats exhibited shorter bladder voiding intervals (307±35 vs 217±37 s; P<0.01), more integral epithelia, and less collagen fiber aggregation, infiltration and degranulation of mast cells, and inflammatory cytokines in the bladder tissue. In the coculture system, compared with the C48 group, the UC-MSC-treated RBL-2H3 cells had suppressed degranulation. CONCLUSIONS UC-MSCs treatment showed a promising therapeutic effect on treating IC in vivo and in vitro. UC-MSCs inhibit mast cell degranulation in IC and could be a potential therapeutic target to ameliorate inflammation in IC.

Identification of novel biomarkers in Hunner's interstitial cystitis using the CIBERSORT, an algorithm based on machine learning.

BACKGROUND:  Hunner's interstitial cystitis (HIC) is a complex disorder characterized by pelvic pain, disrupted urine storage, and Hunner lesions seen on cystoscopy. There are few effective diagnostic biomarkers. In the present study, we used the novel machine learning tool CIBERSORT to measure immune cell subset infiltration and potential novel diagnostic biomarkers for HIC. METHODS: The GSE11783 and GSE57560 datasets were downloaded from the Gene Expression Omnibus for analysis. Ten HIC and six healthy samples from GSE11783 were analyzed using the CIBERSORT algorithm. Gene Set Enrichment Analysis (GSEA) was performed to identify biological processes that occur during HIC pathogenesis. Finally, expression levels of 11 T cell follicular helper cell (Tfh) markers were compared between three healthy individuals and four patients from GSE57560. RESULTS: Six types of immune cells in HIC from GSE11783 showed significant differences, including resting mast cells, CD4+ memory-activated T cells (CD3+ CD4+ HLA-DR+ cells), M0 and M2 macrophages, Tfh cells, and activated natural killer cells. Except for plasma cells, there were no significant differences between Hunner's lesion and non-Hunner's lesion areas in HIC. The GSEA revealed significantly altered biological processes, including antigen-antibody reactions, autoimmune diseases, and infections of viruses, bacteria, and parasites. There were 11 Tfh cell markers with elevated expression in patients from GSE57560. CONCLUSION: This was the first demonstration of Tfh cells and CD3+ CD4+ HLA-DR+ cells with elevated expression in HIC. These cells might serve as novel diagnostic biomarkers.

Does Pollen Trigger Urological Chronic Pelvic Pain Syndrome Flares? A Case-Crossover Analysis in the Multidisciplinary Approach to the Study of Chronic Pelvic Pain Research Network.

PURPOSE: We sought to determine whether pollen triggers urological chronic pelvic pain syndrome flares. MATERIALS AND METHODS: We assessed flare status every 2 weeks for 1 year as part of the Multidisciplinary Approach to the Study of Chronic Pelvic Pain case-crossover analysis of flare triggers (NCT01098279). Flare symptoms, flare start date and exposures in the 3 days before a flare were queried for the first 3 flares and at 3 randomly selected nonflare times. These data were linked to daily pollen count by date and the first 3 digits of participants' zip codes. Pollen count in the 3 days before and day of a flare, as well as pollen rises past established thresholds, were compared to nonflare values by conditional logistic regression. Poisson regression was used to estimate flare rates in the 3 weeks following pollen rises past established thresholds in the full longitudinal study. Analyses were performed in all participants and separately in those who reported allergies or respiratory tract disorders. RESULTS: Although no associations were observed for daily pollen count and flare onset, positive associations were observed for pollen count rises past medium or higher thresholds in participants with allergies or respiratory tract disorders in the case-crossover (OR 1.31, 95% CI 1.04-1.66) and full longitudinal (RR 1.23, 95% CI 1.03-1.46) samples. CONCLUSIONS: We found some evidence to suggest that rising pollen count may trigger flares of urological chronic pelvic pain syndrome. If confirmed in future studies, these findings may help to inform flare pathophysiology, prevention and treatment, and control over the unpredictability of flares.

Shionone alleviates NLRP3 inflammasome mediated pyroptosis in interstitial cystitis injury.

Shionone is a triterpenoid component derived from the herbal medicine Aster tataricus, and it has been reported to possess marked anti-inflammatory properties. The activation of NLRP3 inflammasome plays an important role in cystitis, and the effect of Shionone on NLRP3 inflammasome-dependent pyroptosis remains unclear. In this study, we established an interstitial cystitis (IC) rat model and SV-HUC-1 cell model with CYP or LPS + ATP treatment to mimic inflammation response and induce NLRP3 inflammasome activation. Shionone treatment significantly attenuated the bladder wet weight, score of edema and hemorrhage, enhanced the viability of SV-HUC-1 cell, decreased the rate of pyroptosis. Moreover, Shionone reduced the expression of NF-κB, NLRP3, ASC, Pro-caspase-1, Caspase-1, GSDMD, GSDMD-N at the mRNA and protein levels both in rat and SV-HUC-1 cell model, demonstrating NLRP3 inflammasome pathway was blocked and pyroptosis degree was reduced. These results indicated that Shionone could alleviate interstitial cystitis in Rat model and enhancing the viability of SV-HUC-1 cells via NF-κB/NLRP3/GSDMD-N pathway, which illustrated that Shionone could be used as a drug candidate for the treatment of interstitial cystitis.

Microbiota: a novel regulator of pain.

Among the various regulators of the nervous system, the gut microbiota has been recently described to have the potential to modulate neuronal cells activation. While bacteria-derived products can induce aversive responses and influence pain perception, recent work suggests that "abnormal" microbiota is associated with neurological diseases such as Alzheimer's, Parkinson's disease or autism spectrum disorder (ASD). Here we review how the gut microbiota modulates afferent sensory neurons function and pain, highlighting the role of the microbiota/gut/brain axis in the control of behaviors and neurological diseases. We outline the changes in gut microbiota, known as dysbiosis, and their influence on painful gastrointestinal disorders. Furthermore, both direct host/microbiota interaction that implicates activation of "pain-sensing" neurons by metabolites, or indirect communication via immune activation is discussed. Finally, treatment options targeting the gut microbiota, including pre- or probiotics, will be proposed. Further studies on microbiota/nervous system interaction should lead to the identification of novel microbial ligands and host receptor-targeted drugs, which could ultimately improve chronic pain management and well-being.

Treatment with low-energy shock wave alleviates pain in an animal model of uroplakin 3A-induced autoimmune interstitial cystitis/painful bladder syndrome.

Purpose: To investigate whether treatment with low-energy shock wave (LESW) alleviates pain and bladder dysfunction in a mouse model of uroplakin 3A (UPK3A)-induced interstitial cystitis/painful bladder syndrome (IC/PBS). Materials and Methods: Forty female BALB/c mice were divided into four groups (n=10/group): Sham, Sham+LESW, UPK3A, and UPK3A+LESW. At 6 weeks of age, mice were injected with an emulsion containing water and complete Freund's adjuvant with (UPK3A and UPK3A+LESW groups) or without (Sham and Sham+LESW groups) 200 µg of UPK3A. At 10 weeks, mice received a second dose of Freund's adjuvant to booster immunization. At 12 weeks, mice underwent pain assessment and a frequency volume chart (FVC) test as the pretreatment assessment. LESW treatment and pain assessment were conducted from 13 to 15 weeks. One week after the final treatment, pain assessment and the FVC were conducted again as the post-treatment assessment. Mice were euthanized and sacrificed at 17 weeks. Results: The presence of tactile allodynia and bladder dysfunction was significant in the UPK3A-injected mice. LESW raised the pain threshold and improved bladder function with decreased urinary frequency and increased mean urine output. Expression and secretion of local and systemic inflammatory markers, including tumor necrosis factor-α (TNF-α) and nerve growth factor (NGF), increased after UPK3A immunization. These markers were significantly decreased after LESW treatment (p<0.05). Conclusions: LESW treatment attenuated pain and bladder dysfunction in a UPK3A-induced model of IC/PBS. Local and systemic inflammation was partially controlled, with a reduced number of infiltrated inflammatory cells and reduced levels of TNF-α and NGF.

Risks of interstitial cystitis among patients with systemic lupus erythematosus: A population-based cohort study.

OBJECTIVE: To investigate whether the risk of interstitial cystitis increases among the patients with systemic lupus erythematosus. METHODS: This was a nationwide population-based cohort study. Data were obtained from the National Health Insurance Research Database in Taiwan. Women aged >18 years newly diagnosed as systemic lupus erythematosus during 2001-2008 were identified as the control group. The comparison included individuals randomly selected from the National Health Insurance Research Database in the year of 2000, by matching one systemic lupus erythematosus participant with eight non-systemic lupus erythematosus participants with sex and age. These participants were followed up until being diagnosed as interstitial cystitis, or the end of 2011. Women diagnosed with lupus cystitis were excluded from this study. RESULTS: This study included 7240 women with systemic lupus erythematosus and 57 920 women without systemic lupus erythematosus as controls. The incidence rate of interstitial cystitis was significantly higher in the systemic lupus erythematosus group, with an incidence rate ratio of 2.26 (95% confidence interval 1.57-3.27, P < 0.0001). After adjustment, the risk increased by 2.45-fold (adjusted hazard ratio 2.45, 95% confidence interval 1.57-3.27, P < 0.05). Age as a factor increases incidence rate ratios among all age groups, 2.12-, 3.32- and 4.65-fold. Age ≥45 years had an increased adjusted hazard ratio (2.07, 95% confidence interval 1.37-3.13, P < 0.05). Comorbidities, for example, hypertension, diabetes mellitus, dyslipidemia and renal disease, were insignificant. CONCLUSIONS: This is the first population-based cohort study showing a higher incidence of interstitial cystitis among patients with systemic lupus erythematosus. These findings support the concordance of interstitial cystitis with autoimmune diseases, and the temporal relationship to develop interstitial cystitis in patients with systemic lupus erythematosus.

Cystitis-induced bladder pain is Toll-like receptor 4 dependent in a transgenic autoimmune cystitis murine model: a MAPP Research Network animal study.

Altered Toll-like receptor (TLR)4 activation has been identified in several chronic pain conditions but has not been well studied in interstitial cystitis/bladder pain syndrome (IC/BPS). Our previously published human studies indicated that patients with IC/BPS present altered systemic TLR4-mediated inflammatory responses, which were significantly correlated with reported pain severity. In the present study, we sought to determine whether altered TLR4 activation plays a role in pelvic/bladder pain seen in patients with IC/BPS using our validated IC/BPS-like transgenic autoimmune cystitis model (URO-OVA). URO-OVA mice developed responses consistent with pelvic and bladder pain after cystitis induction, which was associated with increased splenocyte production of TLR4-mediated proinflammatory cytokines IL-1ß, IL-6, and TNF-α. Increased spinal expression of mRNAs for proinflammatory cytokines IL-6 and TNF-α, glial activation markers CD11b and glial fibrillary acidic protein, and endogenous TLR4 ligand high mobility group box 1 was also observed after cystitis induction. Compared with URO-OVA mice, TLR4-deficient URO-OVA mice developed significantly reduced nociceptive responses, although similar bladder inflammation and voiding dysfunction, after cystitis induction. Intravenous administration of TAK-242 (a TLR4-selective antagonist) significantly attenuated nociceptive responses in cystitis-induced URO-OVA mice, which was associated with reduced splenocyte production of TLR4-mediated IL-1ß, IL-6, and TNF-α as well as reduced spinal expression of mRNAs for IL-6, TNF-α, CD11b, glial fibrillary acidic protein, and high mobility group box 1. Our results indicate that altered TLR4 activation plays a critical role in bladder nociception independent of inflammation and voiding dysfunction in the URO-OVA model, providing a potential mechanistic insight and therapeutic target for IC/BPS pain.

A Randomized, Double-blind, Placebo-controlled Trial of Certolizumab Pegol in Women with Refractory Interstitial Cystitis/Bladder Pain Syndrome.

BACKGROUND: Interstitial cystitis/bladder pain syndrome (IC/BPS) is a chronic, disabling bladder disease, with an uncertain pathophysiology and no universally effective treatment. OBJECTIVE: To evaluate the efficacy and safety of certolizumab pegol compared with placebo in women with refractory IC/BPS. DESIGN, SETTING, AND PARTICIPANTS: Eligible women, aged 18-65 yr with moderate to severe IC/BPS, were enrolled in this randomized, double-blind, placebo-controlled pilot study. INTERVENTION: Study patients were randomized at a 2:1 ratio to receive either certolizumab pegol or placebo. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The primary outcome measure was a patient-reported global response assessment (GRA). Secondary endpoints included Interstitial Cystitis Symptom Index (ICSI), Interstitial Cystitis Problem Index (ICPI), and a numeric rating scale for pain and urgency. RESULTS AND LIMITATIONS: The primary endpoint of GRA improvement at week 2 was not met. However, by week 18, there was significant improvement in GRA for certolizumab pegol compared with placebo in pain (odds ratio [OR]=17.3, p=0.002), urgency (OR=9.92, p=0.02), and overall symptoms (OR=15.0, p=0.006). At week 18, there was a statistically significant improvement for certolizumab pegol compared with placebo in change from baseline for ICSI of -3.6 (95% confidence interval [CI]: -6.9 to -0.29, p=0.03), ICPI of -3.0 (95% CI: -6.1 to 0.12, p=0.042), pain scale of -2.0 (95% CI: -3.9 to -0.15, p=0.02), and urgency scale of -1.7 (95% CI: -3.5 to 0.06, p=0.03). There was a significant difference in greater than 30% reduction in pain from baseline comparing certolizumab pegol with placebo at week 18 (OR=13.0, p=0.02). Limitations include a larger, longer, multicenter trial is warranted with phenotypic categorization of patients. CONCLUSIONS: Women with moderate to severe refractory IC/BPS were more likely to experience significant improvement in symptoms with certolizumab pegol compared with placebo therapy. Further investigation of certolizumab pegol for the treatment of IC/BPS is warranted with a larger, longer, multicenter, randomized, placebo-controlled trial. PATIENT SUMMARY: Women with moderate to severe interstitial cystitis/bladder pain syndrome were helped with a medication used to treat autoimmune diseases.

Crosstalk between the immune system and neural pathways in interstitial cystitis/bladder pain syndrome.

Interstitial Cystitis/Bladder Pain Syndrome (IC/BPS) is a condition causing intense pelvic pain and urinary symptoms. While it is thought to affect millions of people and significantly impair quality of life, difficulty with diagnosis and a lack of reliably effective treatment options leave much progress to be made in managing this condition. We describe what is currently known about the immunological and neurological basis of this disease, focusing on the interactions between the immune and nervous system. Evidence for immune involvement in IC/BPS comes from its high co-occurrence with known autoimmune diseases, altered cytokine profiles, and immune cell infiltration in patients. These cytokines have the ability to cross-talk with the nervous system via NGF signaling, resulting in hyper-sensitization of pain receptors, causing them to release substance P and creating a positive feedback loop of neuroinflammation. While it seems that the crosstalk between the immune and nervous system in IC is understood, much of the information comes from studying other diseases or from animal models, and it remains to be confirmed in patients with the disease. Identifying biomarkers and confirming the mechanism of IC/BPS are ultimately important for selecting drug targets and for improving the lives of patients with this disease.

Adelmidrol + sodium hyaluronate in IC/BPS or conditions associated to chronic urothelial inflammation. A translational study.

Interstitial cystitis/painful bladder syndrome (IC/PBS) is a chronic bladder condition characterized by frequent urination, bladder inflammation and pain. It is a particular challenging disease and a clear unmet medical need in terms of identifying new therapeutic strategies. The aim of study was to evaluate the anti-inflammatory effects of intravesical Vessilen® (a new formulation of 2% adelmidrol (the diethanolamide derivative of azelaic acid) + 0.1% sodium hyaluronate) administration in rodent models of IC/BPS and in IC/BPS patients or other bladder disorders. Acute and chronic animal models of cystitis were induced by a single or repetitive intraperitoneal injections of cyclophosphamide (CYP); patients with IC/BPS or with bladder pain syndrome associated with symptoms of the lower urinary tract treated once weekly by bladder instillation of Vessilen® for 8 weeks. CYP instillation caused macroscopic and histological bladder alterations, inflammatory infiltrates, increased mast cell numbers, bladder pain, increased expression of nitrotyrosine, decreased expression of endothelial tight junction zonula occludens-1. Intravesical Vessilen® treatment was able to ameliorate CYP induced bladder inflammation and pain by inhibiting nuclear factor-κB pathway and inflammatory mediator levels as well as reduced mechanical allodynia and nerve growth factor levels. A significant improvement in quality of life and symptom intensity were evident in patients with IC/BPS or other bladder disorders treated with Vessilen®. Vessilen® could be a new therapeutic approach for human cystitis.

Pharmacological management of interstitial cystitis /bladder pain syndrome and the role cyclosporine and other immunomodulating drugs play.

INTRODUCTION: Interstitial cystitis/bladder pain syndrome (IC/BPS) is a symptomatic disorder characterized by pelvic pain and urinary frequency. Immunological responses are considered as one of the possible etiologies of IC/BPS. In this review, we focused on emerging targets, especially on those modulating immunological mechanisms for the treatments of IC/BPS. Area covered: This review was based on the literature search of PubMed/MEDLINE, for which key words following bladder pain syndrome, interstitial cystitis, and/or cyclosporine A (CyA) were used. We discussed current treatments and the drugs targeting the immune responses including CyA and other drugs with different mechanisms including NGF antibodies and P2X3 antagonists. Expert commentary: IC/BPS is often difficult to treat by current treatments. Immunosuppression agents, especially CyA are considered as effective treatments for IC/BPS with Hunner's lesion because these drugs suppress the inflammatory responses in the bladder underlying urinary symptoms of the disease. Base on the previous literatures, we should use CyA for the refractory IC/BPS, especially that with Hunner's lesion due to its side effects. New drugs targeting other mechanisms such as urothelial or afferent nerve dysfunction or new delivery systems such as sustained drug releasing devices or gene therapy techniques may be promising for the future treatments of IC/BPS.

Umbilical cord-derived mesenchymal stem cells alleviated inflammation and inhibited apoptosis in interstitial cystitis via AKT/mTOR signaling pathway.

Interstitial cystitis (IC) is a bladder syndrome characterized by pelvic pain and urinary frequency without infection or other identifiable pathology. There are no effective treatments to cure IC. This study investigated the effects of human umbilical cord-derived mesenchymal stem cells (UC-MSCs) injection on IC rat model. Furthermore, we used a coculture system to find the possible molecular mechanism on the human uroepithelial cells (SV-HUC-1), which was the cell model of IC. A rat model of IC was established via systemic injection with cyclophosphamide (CYP) and a cell model of IC was induced by being exposed to tumor necrosis factor (TNF)-α (10 ng/ml). After one week, UC-MSCs injection significantly ameliorated the bladder voiding function in IC rat model. And the Histo- and immunohistochemical analyses showed that UC-MSCs can repair impaired bladder, reduce mast cell infiltration and inhibit apoptosis of urothelium. ELISA results showed that UC-MSCs can decrease IL-1ß, IL-6 and TNF-α in bladder. In the coculture system, UC-MSCs can promote proliferation of impaired SV-HUC-1 cells, and inhibit apoptosis. However, while knocked down EGF secreted by UC-MSCs with siRNA, the effects would be weaken. Western blot showed that UC-MSCs increase protein expression levels of p-AKT and p-mTOR in SV-HUC-1 cells, and decrease the levels of cleaved caspase-3. Taken together, we provide evidence that UC-MSCs therapy can successfully alleviate IC in a preclinical animal Model and cell model by alleviating inflammation, promoting proliferation and inhibiting apoptosis. In addition, we demonstrate that the AKT/mTOR signaling pathway was activated.

Evidence for the Role of Mast Cells in Cystitis-Associated Lower Urinary Tract Dysfunction: A Multidisciplinary Approach to the Study of Chronic Pelvic Pain Research Network Animal Model Study.

Bladder inflammation frequently causes cystitis pain and lower urinary tract dysfunction (LUTD) such as urinary frequency and urgency. Although mast cells have been identified to play a critical role in bladder inflammation and pain, the role of mast cells in cystitis-associated LUTD has not been demonstrated. Interstitial cystitis/bladder pain syndrome (IC/BPS) is a chronic and debilitating inflammatory condition of the urinary bladder characterized by the hallmark symptoms of pelvic pain and LUTD. In this study we investigated the role of mast cells in LUTD using a transgenic autoimmune cystitis model (URO-OVA) that reproduces many clinical correlates of IC/BPS. URO-OVA mice express the membrane form of the model antigen ovalbumin (OVA) as a self-antigen on the urothelium and develop bladder inflammation upon introduction of OVA-specific T cells. To investigate the role of mast cells, we crossed URO-OVA mice with mast cell-deficient KitW-sh mice to generate URO-OVA/KitW-sh mice that retained urothelial OVA expression but lacked endogenous mast cells. We compared URO-OVA mice with URO-OVA/KitW-sh mice with and without mast cell reconstitution in response to cystitis induction. URO-OVA mice developed profound bladder inflammation with increased mast cell counts and LUTD, including increased total number of voids, decreased mean volume voided per micturition, and decreased maximum volume voided per micturition, after cystitis induction. In contrast, similarly cystitis-induced URO-OVA/KitW-sh mice developed reduced bladder inflammation with no mast cells and LUTD detected. However, after mast cell reconstitution URO-OVA/KitW-sh mice restored the ability to develop bladder inflammation and LUTD following cystitis induction. We further treated URO-OVA mice with cromolyn, a mast cell membrane stabilizer, and found that cromolyn treatment reversed bladder inflammation and LUTD in the animal model. Our results provide direct evidence for the role of mast cells in cystitis-associated LUTD, supporting the use of mast cell inhibitors for treatment of certain forms of IC/BPS.

Hunner-Type (Classic) Interstitial Cystitis: A Distinct Inflammatory Disorder Characterized by Pancystitis, with Frequent Expansion of Clonal B-Cells and Epithelial Denudation.

Interstitial cystitis (IC) is a chronic bladder disease with urinary frequency, bladder discomfort or bladder pain of unknown etiology. Based on cystoscopic findings, patients with IC are classified as either Hunner-type/classic IC (HIC), presenting with a specific Hunner lesion, or non-Hunner-type IC (NHIC), presenting with no Hunner lesion, but post-hydrodistension mucosal bleeding. Inflammatory cell infiltration, composed predominantly of lymphocytes, plasma cells and epithelial denudation, has in the past been documented as a major pathological IC finding. However, the significance of the pathological evaluation of IC, especially with regard to the difference between HIC and NHIC, has been downplayed in recent years. In this study, we performed immunohistochemical quantification of infiltrating T-lymphocytes, B-lymphocytes and plasma cells, and measured the amount of residual epithelium in urinary bladder biopsy specimens taken from patients with HIC and NHIC, and those with no IC, using image analysis software. In addition, in situ hybridization of the light chains was performed to examine clonal B-cell expansion. Lymphoplasmacytic infiltration was significantly more severe in HIC specimens than in NHIC specimens (P <0.0001). Substantial lymphoplasmacytic inflammation (≥200 cells/mm2) was observed in 93% of HIC specimens, whereas only 8% of NHIC specimens were inflamed. Plasmacytic infiltration was more prominent in HIC specimens compared with NHIC and non-IC cystitis specimens (P <0.005). Furthermore, expansion of light-chain-restricted B-cells was observed in 31% of cases of HIC. The amount of residual epithelium was decreased in HIC specimens compared with NHIC specimens and non-IC cystitis specimens (P <0.0001). These results suggest that NHIC and HIC are distinct pathological entities, with the latter characterized by pancystitis, frequent clonal B-cell expansion and epithelial denudation. An abnormality in the B-cell population may be involved in the pathogenesis of HIC.

Hyaluronic acid decreases IL-6 and IL-8 secretion and permeability in an inflammatory model of interstitial cystitis.

Hyaluronic acid (HA) has received a lot of attention recently as a biomaterial with applications in wound healing, drug delivery, vascular repair and cell and/or gene delivery. Interstitial cystitis (IC) is characterised by an increase in the permeability of the bladder wall urothelium due to loss of the glycosaminoglycan (GAG) layer. The degradation of the urothelium leads to chronic pain and urinary dysfunction. The aetiology of the degradation of the GAG layer in this instance is currently unknown. At a clinical level, GAG replacement therapy using a HA solution is currently utilised as a treatment for IC. However, there is a significant lack of data on the mechanism of action of HA in IC. The current study investigates the mechanistic effect of clinically relevant HA treatment on an in vitro model of IC using urothelial cells, examining cytokine secretion, GAG secretion and trans-epithelial permeability. This study demonstrates that HA can significantly decrease induced cytokine secretion (4-5 fold increase), increase sulphated GAG production (2-fold increase) and without altering tight junction expression, decrease trans-epithelial permeability, suggesting that the HA pathway is a clinical target and potential treatment vector.

Chronic pelvic allodynia is mediated by CCL2 through mast cells in an experimental autoimmune cystitis model.

The cause of chronic pelvic pain in interstitial cystitis/painful bladder syndrome (IC/PBS) remains unclear; autoimmunity is a possible etiology. We have recently shown that injection of a single immunogenic peptide of uroplakin 3A (UPK3A 65-84) induces experimental autoimmune cystitis (EAC) in female BALB/cJ mice that is unique among experimental models in accurately reflecting both the urinary symptoms and pelvic pain of IC/PBS. The aim of this project was to identify the roles of mast cells and mast cell chemoattractant/activator monocyte chemoattractant protein-1 [chemokine (C-C motif) ligand 2 (CCL2)] in the allodynia in this model. We immunized 6- to 8-wk-old female BALB/cJ mice with UPK3A 65-84 peptide and, 5-40 days later, observed increased responses to stimulation of the suprapubic abdominal and hindpaw surfaces with von Frey monofilaments compared with mice injected with adjuvant alone. Suprapubic and hindpaw tactile allodynia responses by EAC mice were blocked by instillation of lidocaine into the bladder but not by lidocaine in the uterus, confirming the bladder as the source of the hypersensitivity. Markedly increased numbers of activated mast cells and expression of CCL2 were found in the bladder after immunization with UPK3A 65-84. Hypersensitive responses were inhibited by mast cell stabilizer cromolyn sodium and antagonists of histamine receptors 1 and 2. Furthermore, BALB/cJ mice with deletion of the Ccl2 or chemokine (C-C motif) receptor 2 gene exhibited markedly reduced allodynia and accumulation of mast cells after UPK3A 65-84 immunization. These results show that UPK3A 65-84 immunization causes chronic visceral allodynia and suggest that it is mediated by CCL2-driven mast cell accumulation in the bladder.

Pharmacokinetic considerations for therapies used to treat interstitial cystitis.

INTRODUCTION: Interstitial cystitis (IC) or bladder pain syndrome (BPS) is defined as supra-pubic pain related to bladder filling. IC is characterized by a particular symptom complex with no identifiable causes; as with bladder hypersensitivity it is usually associated with urinary frequency and urgency with bladder pain. No current treatments have a significant impact on symptoms over time. AREAS COVERED: This systematic review examines the pharmacokinetic aspects and adverse event of present IC therapy to highlight appropriate treatment to improve the symptoms of IC. This article reviews material obtained via Medline, PubMed, and EMBASE literature searches up to October 2013. EXPERT OPINION: The correct approach to IC should consider a multidisciplinary team of specialists and a multimodal treatment package that include psychotherapy, behavior change, physical activation, and analgesic treatment. Unfortunately, a single therapeutic target for IC is not yet known. With regard to pathophysiology and therapy, there is more to discover. The first insult damages the bladder urothelium, hence vehicles that lead the drug to penetrate the wall of the bladder might be a novel strategic approach.