Experimental autoimmune cystitis: a potential murine model for ulcerative interstitial cystitis

Hypertension and urologic chronic pelvic pain syndrome: An analysis of MAPP-I data

BACKGROUND

Urologic chronic pelvic pain syndrome (UCPPS), which includes interstitial cystitis/bladder pain syndrome (IC/BPS) and chronic prostatitis (CP/CPPS), is associated with increased voiding frequency, nocturia, and chronic pelvic pain. The cause of these diseases is unknown and likely involves many different mechanisms. Dysregulated renin-angiotensin-aldosterone-system (RAAS) signaling is a potential pathologic mechanism for IC/BPS and CP/CPPS. Many angiotensin receptor downstream signaling factors, including oxidative stress, fibrosis, mast cell recruitment, and increased inflammatory mediators, are present in the bladders of IC/BPS patients and prostates of CP/CPPS patients. Therefore, we aimed to test the hypothesis that UCPPS patients have dysregulated angiotensin signaling, resulting in increased hypertension compared to controls. Secondly, we evaluated symptom severity in patients with and without hypertension and antihypertensive medication use.

METHODS

Data from UCPPS patients (n = 424), fibromyalgia or irritable bowel syndrome (positive controls, n = 200), and healthy controls (n = 415) were obtained from the NIDDK Multidisciplinary Approach to the Study of Chronic Pelvic Pain I (MAPP-I). Diagnosis of hypertension, current antihypertensive medications, pain severity, and urinary symptom severity were analyzed using chi-square test and t-test.

RESULTS

The combination of diagnosis and antihypertensive medications use was highest in the UCPPS group (n = 74, 18%), followed by positive (n = 34, 17%) and healthy controls (n = 48, 12%, p = 0.04). There were no differences in symptom severity based on hypertension in UCPPS and CP/CPPS; however, IC/BPS had worse ICSI (p = 0.031), AUA-SI (p = 0.04), and BPI pain severity (0.02). Patients (n = 7) with a hypertension diagnosis not on antihypertensive medications reported the greatest severity of pain and urinary symptoms.

CONCLUSION

This pattern of findings suggests that there may be a relationship between hypertension and UCPPS. Treating hypertension among these patients may result in reduced pain and symptom severity. Further investigation on the relationship between hypertension, antihypertensive medication use, and UCPPS and the role of angiotensin signaling in UCPPS conditions is needed.

The Unmet Needs for Studying Chronic Pelvic/Visceral Pain Using Animal Models

The different definitions of chronic pelvic/visceral pain used by international societies have changed over the years. These differences have a great impact on the way researchers study chronic pelvic/visceral pain. Recently, the role of systemic changes, including the role of the central nervous system, in the perpetuation and chronification of pelvic/visceral pain has gained weight. Consequently, researchers are using animal models that resemble those systemic changes rather than using models that are organ- or tissue-specific. In this review, we discuss the advantages and disadvantages of using bladder-centric and systemic models, enumerating some of the central nervous system changes and pain-related behaviors occurring in each model. We also present some drawbacks when using animal models and pain-related behavior tests and raise questions about possible, yet to be demonstrated, investigator-related bias. We also suggest new approaches to study chronic pelvic/visceral pain by refining existing animal models or using new ones.

Activation of CXCL13/CXCR5 axis aggravates experimental autoimmune cystitis and interstitial cystitis/bladder pain syndrome

The abnormal CXCL13/CXCR5 axis is involved in many inflammatory diseases and its selective inhibitor, TAK-799 has exhibited strong anti-inflammatory potency. The sequencing of clinical specimens from interstitial cystitis/bladder pain syndrome (IC/BPS) has shown that CXCL13 and CXCR5 are highly expressed, but the role of CXCL13/CXCR5 axis in IC/BPS has not been rarely reported. Therefore, in this study, we analyzed the GSE11783 sequencing data of IC/BPS patients and investigate the role and mechanism of CXCL13/CXCR5 axis and TAK-779 in the mouse model of experimental autoimmune cystitis (EAC). We verified that CXCL13 and CXCR5 were significantly up-regulated in EAC model. EAC mice exhibited increased bladder inflammatory factors (IL-6, TNF-α, IL-1β), apoptosis-related proteins (Bax, Caspase-3, Caspase-8), frequency of voiding. Using TAK779 to block CXCL13/CXCR5 axis significantly attenuated these inflammatory damages and efficiently improved bladder function (significant reduction in micturition frequency, significant prolongation of inter-contraction interval). Further investigation showed that inhibiton of JNK and NF-kappaB activation, the bioinformatics analysis-indicated downstream signaling of CXCL13/CXCR5 axis, is responsible for the protective effect of TAK779. Taken together, we demonstrate that activation of the CXCL13/CXCR5 axis is involved in the pathophysiology of IC/BPS and EAC. Blocking CXCL13/CXCR5 axis activation by TAK-779 reduces bladder inflammation and improves bladder function in EAC mice.

Interstitial cystitis/bladder pain syndrome: The evolving landscape, animal models and future perspectives

Interstitial cystitis/bladder pain syndrome is a debilitating condition of unknown etiology characterized by persistent pelvic pain with lower urinary tract symptoms and comprises a wide variety of potentially clinically useful phenotypes with different possible etiologies. Current clinicopathological and genomic evidence suggests that interstitial cystitis/bladder pain syndrome should be categorized by the presence or absence of Hunner lesions, rather than by clinical phenotyping based on symptomatology. The Hunner lesion subtype is a distinct inflammatory disease with proven bladder etiology characterized by epithelial denudation and enhanced immune responses frequently accompanied by clonal expansion of infiltrating B cells, with potential engagement of infection. Meanwhile, the non-Hunner lesion subtype is a non-inflammatory disorder with little evidence of bladder etiology. It is potentially associated with urothelial malfunction and neurophysiological dysfunction, and frequently presents with somatic and/or psychological symptoms, that commonly result in central nervous sensitization. Animal models of autoimmune cystitis and neurogenic sensitization might serve as disease models for the Hunner lesion and non-Hunner lesion subtypes, respectively. Here, we revisit the taxonomy of interstitial cystitis/bladder pain syndrome according to current research, and discuss its potential pathophysiology and representative animal models. Categorization of interstitial cystitis/bladder pain syndrome based on cystoscopy is mandatory to design optimized treatment and research strategies for each subtype. A tailored approach that specifically targets the characteristic inflammation and epithelial denudation for the Hunner lesion subtype, or the urothelial malfunction, sensitized/altered nervous system and psychosocial problems for the non-Hunner lesion subtype, is essential for better clinical management and research progress in this complex condition.

Application of Adult and Pluripotent Stem Cells in Interstitial Cystitis/Bladder Pain Syndrome Therapy: Methods and Perspectives

Interstitial cystitis/bladder pain syndrome (IC/BPS) is a multifactorial, chronic disease without definite etiology characterized by bladder-related pelvic pain. IC/BPS is associated with pain that negatively affects the quality of life. There are various therapeutic approaches against IC/BPS. However, no efficient therapeutic agent against IC/BPS has been discovered yet. Urothelium dysfunction is one of the key factors of IC/BPS-related pathogenicity. Stem cells, including adult stem cells (ASCs) and pluripotent stem cells (PSCs), such as embryonic stem cells (ESCs) and induced PSCs (iPSCs), possess the abilities of self-renewal, proliferation, and differentiation into various cell types, including urothelial and other bladder cells. Therefore, stem cells are considered robust candidates for bladder regeneration. This review provides a brief overview of the etiology, pathophysiology, diagnosis, and treatment of IC/BPS as well as a summary of ASCs and PSCs. The potential of ASCs and PSCs in bladder regeneration via differentiation into bladder cells or direct transplantation into the bladder and the possible applications in IC/BPS therapy are described in detail. A better understanding of current studies on stem cells and bladder regeneration will allow further improvement in the approaches of stem cell applications for highly efficient IC/BPS therapy.

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-1β, 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-1β, 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.

Comprehensive urinary metabolomic characterization of a genetically induced mouse model of prostatic inflammation

Dysfunction of the lower urinary tract commonly afflicts the middle-aged and aging male population. The etiology of lower urinary tract symptoms (LUTS) is multifactorial. Benign prostate hyperplasia, fibrosis, smooth muscle contractility, and inflammation likely contribute. Here we aim to characterize the urinary metabolomic profile associated with prostatic inflammation, which could inform future personalized diagnosis or treatment, as well as mechanistic research. Quantitative urinary metabolomics was conducted to examine molecular changes following induction of inflammation via conditional Interleukin-1β expression in prostate epithelia using a novel transgenic mouse strain. To advance method development for urinary metabolomics, we also compared different urine normalization methods and found that normalizing urine samples based on osmolality prior to LC-MS most completely separated urinary metabolite profiles of mice with and without prostate inflammation via principal component analysis. Global metabolomics was combined with advanced machine learning feature selection and classification for data analysis. Key dysregulated metabolites and pathways were identified and were relevant to prostatic inflammation, some of which overlapped with our previous study of human LUTS patients. A binary classification model was established via the support vector machine algorithm to accurately differentiate control and inflammation groups, with an area-under-the-curve value of the receiver operating characteristic of 0.81, sensitivity of 0.974 and specificity of 0.995, respectively. This study generated molecular profiles of non-bacterial prostatic inflammation, which could assist future efforts to stratify LUTS patients and develop new therapies.

Sub-noxious Intravesical Lipopolysaccharide Triggers Bladder Inflammation and Symptom Onset in A Transgenic Autoimmune Cystitis Model: A MAPP Network Animal Study

Patients with interstitial cystitis/bladder pain syndrome (IC/BPS) can potentially develop symptom flares after exposure to minor bladder irritants such as subclinical bacterial infection. To reproduce this symptom onset, we intravesically instilled a sub-noxious dose of uropathogenic E. coli component lipopolysaccharide (LPS) in young URO-OVA/OT-I mice, a transgenic autoimmune cystitis model that spontaneously develops bladder inflammation at ≥10 weeks of age. Female URO-OVA/OT-I mice (6-weeks old) were treated intravesically with phosphate-buffered saline (PBS) or PBS containing a sub-noxious dose (1 μg) of LPS. Mice were evaluated for bladder inflammation, pelvic pain, and voiding dysfunction at days 1, 7, and 14 post-treatment. Mice treated with LPS but not PBS developed early bladder inflammation with increased macrophage infiltration. Accordingly, the inflamed bladders expressed increased levels of mRNA for proinflammatory cytokines (IL-1β and IL-6) and pain mediator (substance P precursor). In addition, LPS-treated mice exhibited pelvic pain and voiding dysfunction such as increased urinary frequency and reduced bladder capacity. These functional changes sustained up to day 14 tested. Our results indicate that a single sub-noxious dose of intravesical LPS triggers early bladder inflammation and symptom onset in URO-OVA/OT-I mice, providing a useful model for IC/BPS symptom flare study.

Establishment of a Novel Autoimmune Experimental Model of Bladder Pain Syndrome/Interstitial Cystitis in C57BL/6 Mice

The aim of this study is to identify whether vaccinating twice with bladder homogenate can establish a new model of experimental autoimmune cystitis (EAC) in C57BL/6 strain mice. C57BL/6 mice were vaccinated with bladder homogenate in complete Freund's adjuvant (CFA) and boost immunized with bladder homogenate in incomplete Freund's adjuvant (IFA) after 2 weeks were used as the EAC model. Mice immunized with phosphate-buffered saline (PBS) in CFA or IFA were used as the control. Micturition habits and suprapubic-pelvic pain threshold were measured 4 weeks after primary immunization. Bladder to body weight ratios and expression of inflammatory cytokines and neurokinin 1 receptor (NK1R) were then examined. Histologic and immunohistochemical examination of the bladder was carried out, and IL-1β, IFN-γ, and TNF-α production by the kidneys, liver, and lungs was also tested. Double-immunized mice were extensively sensitive to pressure applied on the pelvic area (P < 0.001). Compared to single-immunized mice or controls, double-immunized mice showed more micturition frequency, lower urine output per micturition, higher bladder to body weight ratio, and significant elevation in the expression of inflammatory cytokines, including IL-1β, IL-4, IL-6, IL-10, IFN-γ, and TNF-α (all P < 0.05). NK1R gene expression was significantly increased in double-immunized mice compared to the other three groups (P < 0.001). A nonspecific immune response occurred in the liver but was much weaker than bladder inflammation. Our dual immunization EAC model in C57BL/6 mice can effectively mimic the symptoms and pathophysiologic characteristics of BPS/IC and thus can be widely used to investigate the pathogenesis and therapeutic strategies of BPS/IC.

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 Kit^W-sh mice to generate URO-OVA/Kit^W-sh mice that retained urothelial OVA expression but lacked endogenous mast cells. We compared URO-OVA mice with URO-OVA/Kit^W-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/Kit^W-sh mice developed reduced bladder inflammation with no mast cells and LUTD detected. However, after mast cell reconstitution URO-OVA/Kit^W-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.

Pelvic floor spasm as a cause of voiding dysfunction

PURPOSE OF REVIEW

Pelvic floor disorders can present with lower urinary tract symptoms, bowel, sexual dysfunction, and/or pain. Symptoms of pelvic muscle spasm (nonrelaxing pelvic floor or hypertonicity) vary and can be difficult to recognize. This makes diagnosis and management of these disorders challenging. In this article, we review the current evidence on pelvic floor spasm and its association with voiding dysfunction.

RECENT FINDINGS

To distinguish between the different causes of voiding dysfunction, a video urodynamics study and/or electromyography is often required. Conservative measures include patient education, behavioral modifications, lifestyle changes, and pelvic floor rehabilitation/physical therapy. Disease-specific pelvic pain and pain from pelvic floor spasm needs to be differentiated and treated specifically. Trigger point massage and injections relieves pain in some patients. Botulinum toxin A, sacral neuromodulation, and acupuncture has been reported in the management of patients with refractory symptoms.

SUMMARY

Pelvic floor spasm and associated voiding problems are heterogeneous in their pathogenesis and are therefore often underrecognized and undertreated; it is therefore essential that a therapeutic strategy needs to be personalized to the individual patient's requirements. Therefore, careful evaluation and assessment of individuals using a multidisciplinary team approach including a trained physical therapist/nurse clinician is essential in the management of these patients.

Interleukin-33 and Mast Cells Bridge Innate and Adaptive Immunity: From the Allergologist's Perspective

Interleukin (IL) 33, a member of the IL-1 superfamily, is an “alarmin” protein and is secreted in its active form from damaged cells undergoing necrotic cell death. Mast cells are one of the main effector cell types in allergic disorders. They secrete a variety of mediators, including T helper 2 cytokines. As mast cells have high-affinity IgE receptors (FcεRI) on their surface, they can capture circulating IgE. IgE-bound mast cells degranulate large amounts of histamine, heparin, and proteases when they encounter antigens. As IL-33 is an important mediator of innate immunity and mast cells play an important role in adaptive immune responses, interactions between the two could link innate and adaptive immunity. IL-33 promotes the adhesion of mast cells to laminin, fibronectin, and vitronectin. IL-33 increases the expression of adhesion molecules, such as intracellular adhesion molecule-1 and vascular cell adhesion molecule-1, in endothelial cells, thus enhancing mast cell adhesion to blood vessel walls. IL-33 stimulates mast cell proliferation by activating the ST2/Myd88 pathway; increases mast cell survival by the activation of survival proteins such as Bcl-XL; and promotes the growth, development, and maturation of mast cell progenitors. IL-33 is also involved in the activation of mature mast cells and production of different proinflammatory cytokines. The interaction of IL-33 and mast cells could have important clinical implications in the field of clinical urology. Epithelial dysfunction and mast cells could play an important role in the pathogenesis of interstitial cystitis. Urinary levels of IL-33 significantly increase in patients with interstitial cystitis. In addition, the number of mast cells significantly increase in the urinary bladders of patients with interstitial cystitis. Therefore, inhibition of mast cell activation and degranulation in response to increase in IL-33 is a potential therapeutic target in the treatment of interstitial cystitis.

The severity of experimental autoimmune cystitis can be ameliorated by anti-CXCL10 Ab treatment

Background

Interstitial cystitis (IC), more recently called painful bladder syndrome (PBS) is a complex disease associated with chronic bladder inflammation that primarily affects women. Its symptoms include frequent urinary urgency accompanied by discomfort or pain in the bladder and lower abdomen. In the United States, eight million people, mostly women, have IC/PBS. New evidence that autoimmune mechanisms are important in the pathogenesis of IC/PBS triggered interest.

Methodology/Principal Findings

SWXJ mice immunized with a homogenate of similar mice’s urinary bladders develop an autoimmune phenotype comparable to clinical IC with functional and histological alterations confined to the urinary bladder. Using the murine model of experimental autoimmune cystitis (EAC), we found that serum levels of CXCR3 ligand and local T helper type 1 (Th1) cytokine are elevated. Also, IFN-γ-inducible protein10 (CXCL10) blockade attenuated overall cystitis severity scores; reversed the development of IC; decreased local production of CXCR3 and its ligands, IFN-γ, and tumor necrosis factor-α (TNF-α); and lowered systemic levels of CXCR3 ligands. Urinary bladder CD4⁺ T cells, mast cells, and neutrophils infiltrates were reduced following anti-CXCL10 antibody (Ab) treatment of mice. Anti-CXCL10 Ab treatment also reversed the upregulated level of CXCR3 ligand mRNA at urinary bladder sites. The decreased number and percentage of systemic CD4⁺ T cells in EAC mice returned to normal after anti-CXCL10 Ab treatment.

Conclusion/Significance

Taken together, our findings provide important new information about the mechanisms underlying EAC pathogenesis, which has symptoms similar to those of IC/PBS. CXCL10 has the potential for use in developing new therapy for IC/PBS.

Uroplakin peptide-specific autoimmunity initiates interstitial cystitis/painful bladder syndrome in mice

The pathophysiology of interstitial cystitis/painful bladder syndrome (IC/PBS) is enigmatic. Autoimmunity and impaired urothelium might lead the underlying pathology. A major shortcoming in IC/PBS research has been the lack of an appropriate animal model. In this study, we show that the bladder specific uroplakin 3A-derived immunogenic peptide UPK3A 65–84, which contains the binding motif for IA^d MHC class II molecules expressed in BALB/c mice, is capable of inducing experimental autoimmune cystitis in female mice of that strain. A highly antigen-specific recall proliferative response of lymph node cells to UPK3A 65–84 was observed, characterized by selectively activated CD4+ T cells with a proinflammatory Th1-like phenotype, including enhanced production of interferon γ and interleukin-2. T cell infiltration of the bladder and bladder-specific increased gene expression of inflammatory cytokines were observed. Either active immunization with UPK3A 65–84 or adoptive transfer of peptide-activated CD4+ T cells induced all of the predominant IC/PBS phenotypic characteristics, including increased micturition frequency, decreased urine output per micturition, and increased pelvic pain responses to stimulation with von Frey filaments. Our study demonstrates the creation of a more specific experimental autoimmune cystitis model that is the first inducible model for IC/PBS that manifests all of the major symptoms of this debilitating condition.

Urothelial antigen-specific CD4+ T cells function as direct effector cells and induce bladder autoimmune inflammation independent of CD8+ T cells

The role of CD4(+) T cells in bladder autoimmune inflammation has not been identified because of the lack of a proper animal model. We investigated CD4(+) T-cell responses to bladder urothelial ovalbumin (OVA), a model self-antigen (Ag), in transgenic URO-OVA mice. The expression of bladder urothelial OVA rendered mice unresponsive to OVA and resulted in quick clearance of Ag-specific CD4(+) T cells. Adoptive transfer of naive OVA-specific CD4(+) T cells led to exogenous T-cell proliferation, activation, and bladder infiltration but no inflammatory induction. In contrast, adoptive transfer of preactivated OVA-specific CD4(+) T cells induced bladder inflammation. Studies further demonstrated that CD4(+) T cells induced bladder inflammation in URO-OVA mice depleted of CD8(+) T cells or deficient in the recombinase activating gene-1 (Rag-1(-/-)). These results indicate that urothelial Ag-specific CD4(+) T cells can function as direct effector cells to induce bladder autoimmune inflammation independent of CD8(+) T cells.

Models of inflammation of the lower urinary tract

Inflammation of the lower urinary tract occurs frequently in people. The causes remain obscure, with the exception of urinary tract infection. Animal models have proven useful for investigating and assessing mechanisms underlying symptoms associated with lower urinary tract inflammation and options for suppressing these symptoms. This review will discuss various animal models of lower urinary tract inflammation, including feline spontaneous (interstitial) cystitis, neurogenic cystitis, autoimmune cystitis, cystitis induced by intravesical instillation of chemicals or bacterial products (particularly lipopolysaccharide or LPS), and prostatic inflammation initiated by transurethral instillation of bacteria. Animal models will continue to be of significant value in identifying mechanisms resulting in bladder inflammation, but the relevance of some of these models to the causes underlying clinical disease is unclear. This is primarily because of the lack of understanding of causes of these disorders in people. Comparative and translational studies are required if the full potential of findings obtained with animal models to improve prevention and treatment of lower urinary tract inflammation in people is to be realized.

Intravesical dimethyl sulfoxide inhibits acute and chronic bladder inflammation in transgenic experimental autoimmune cystitis models

New animal models are greatly needed in interstitial cystitis/painful bladder syndrome (IC/PBS) research. We recently developed a novel transgenic cystitis model (URO-OVA mice) that mimics certain key aspects of IC/PBS pathophysiology. This paper aimed to determine whether URO-OVA cystitis model was responsive to intravesical dimethyl sulfoxide (DMSO) and if so identify the mechanisms of DMSO action. URO-OVA mice developed acute cystitis upon adoptive transfer of OVA-specific OT-I splenocytes. Compared to PBS-treated bladders, the bladders treated with 50% DMSO exhibited markedly reduced bladder histopathology and expression of various inflammatory factor mRNAs. Intravesical DMSO treatment also effectively inhibited bladder inflammation in a spontaneous chronic cystitis model (URO-OVA/OT-I mice). Studies further revealed that DMSO could impair effector T cells in a dose-dependent manner in vitro. Taken together, our results suggest that intravesical DMSO improves the bladder histopathology of IC/PBS patients because of its ability to interfere with multiple inflammatory and bladder cell types.

EAU guidelines on chronic pelvic pain

CONTEXT

These guidelines were prepared on behalf of the European Association of Urology (EAU) to help urologists assess the evidence-based management of chronic pelvic pain (CPP) and to incorporate the recommendations into their clinical practice.

OBJECTIVE

To revise guidelines for the diagnosis, therapy, and follow-up of CPP patients.

EVIDENCE ACQUISITION

Guidelines were compiled by a working group and based on a systematic review of current literature using the PubMed database, with important papers reviewed for the 2003 EAU guidelines as a background. A panel of experts weighted the references.

EVIDENCE SYNTHESIS

The full text of the guidelines is available through the EAU Central Office and the EAU Web site (www.uroweb.org). This article is a short version of the full guidelines text and summarises the main conclusions from the guidelines on the management of CPP.

CONCLUSIONS

A guidelines text is presented including chapters on chronic prostate pain and bladder pain syndromes, urethral pain, scrotal pain, pelvic pain in gynaecologic practice, neurogenic dysfunctions, the role of the pelvic floor and pudendal nerve, psychological factors, general treatment of CPP, nerve blocks, and neuromodulation. These guidelines have been drawn up to provide support in the management of the large and difficult group of patients suffering from CPP.

Lower urinary tract phenotype of experimental autoimmune cystitis in mouse: a potential animal model for interstitial cystitis

OBJECTIVE

To examine bladder function in a newly developed experimental autoimmune cystitis (EAC) model in female SWXJ strain mice, as a potential animal model for interstitial cystitis (IC).

MATERIALS AND METHODS

In all, 20 SWXJ female mice were divided into two groups: an EAC group immunized with mouse bladder homogenate in complete Freund's adjuvant (CFA) and a control group immunized with CFA alone. At 4 months after injection, the bladder function of some mice (six) was studied with 24-h micturition habits using metabolic cages and conscious cystometrography (CMG). The bladder and lung were harvested for histological examination and to assess interferon-gamma (IFN-gamma) mRNA expression.

RESULTS

Histology examination showed obviously thickened lamina propria, infiltration of lymphocytes, giant cells, and increased mast cells in the detrusor muscle of the EAC mice. The lungs of EAC mice showed normal histology. The IFN-gamma mRNA expression increased significantly in the bladder, but not in the lung of the EAC mice. The 24-h micturition habits measurements showed increased frequency of urination in the EAC mice compared with the controls. Similarly, CMG showed decreased intercontraction intervals and voided volumes per micturition in the EAC mice compared with the controls. However, there were no significant differences in peak voiding pressure or total voiding volume between the EAC and control mice.

CONCLUSIONS

Our murine EAC model has comparable functional and histological alterations to those seen in human IC, and may provide a useful model for the study of the pathogenesis and treatment of IC.

Angiotensin II plays a role in acute murine experimental autoimmune cystitis

OBJECTIVES

To investigate whether angiotensin II (AII) receptor antagonism decreases the inflammation and oedema in acute murine experimental autoimmune cystitis (EAC), as interstitial cystitis (IC) might have an autoimmune component and AII has been implicated in autoimmune-mediated vascular congestion, oedema and scarring.

MATERIALS AND METHODS

Female Balb/cAN mice were divided into three treatment groups (eight in each group) that were autoimmunized with bladder homogenate to induce EAC. One group received an AII type 1 receptor (AT(1)) antagonist, one group an AII type 2 receptor (AT(2)) antagonist, and one group remained untreated (EAC). A control and sham-injected group were also included. After 10 weeks, bladders were removed, sectioned, and stained with haematoxylin and eosin.

RESULTS

Grossly, there was no thickening or adhesions in the bladders of the control or sham-injected mice. In five of seven surviving EAC bladders, there were dense adhesions to surrounding peritoneal structures. There were also adhesions and bladder thickening in all of the AT(2) antagonist-treated mice (though in a milder form) but in only two of seven surviving AT(1) antagonist-treated mice. There was no inflammation or oedema in the sham and control groups. All the EAC bladders were inflamed, with submucosal oedema and urothelial detachment from the lamina propria. In the AT(1) antagonist-treated mice there was no inflammation or oedema. By contrast, all AT(2) antagonist-treated mice had moderate inflammation and minor detachment of the urothelium from the lamina propria.

CONCLUSIONS

AT(1) receptor blockade ameliorated the inflammatory infiltration, submucosal oedema, and urothelial detachment associated with EAC in mice. This was achieved to a lesser extent by AT(2) receptor blockade. If some patients with IC have a pathophysiology similar to that of EAC mice, there might be potential benefit from AII receptor blockade.

The Mast Cell in Interstitial Cystitis: Role in Pathophysiology and Pathogenesis

Current evidence from clinical and laboratory studies confirms that mast cells play a central role in the pathogenesis and pathophysiology of interstitial cystitis (IC). In this article, we focus on the role of the mast cell in IC and examine the ways in which mast cells and other pathophysiologic mechanisms are interrelated in this disease. Identifying the patients with IC who have mast cell proliferation and activation will enable us to address this aspect of disease pathophysiology in these individuals with targeted pharmacotherapy to inhibit mast cell activation and mediator release.

Gene expression profiling of mouse bladder inflammatory responses to LPS, substance P, and antigen-stimulation

Inflammatory bladder disorders such as interstitial cystitis (IC) deserve attention since a major problem of the disease is diagnosis. IC affects millions of women and is characterized by severe pain, increased frequency of micturition, and chronic inflammation. Characterizing the molecular fingerprint (gene profile) of IC will help elucidate the mechanisms involved and suggest further approaches for therapeutic intervention. Therefore, in the present study we used established animal models of cystitis to determine the time course of bladder inflammatory responses to antigen, Escherichia coli lipopolysaccharide (LPS), and substance P (SP) by morphological analysis and cDNA microarrays. The specific aim of the present study was to compare bladder inflammatory responses to antigen, LPS, and SP by morphological analysis and cDNA microarray profiling to determine whether bladder responses to inflammation elicit a specific universal gene expression response regardless of the stimulating agent. During acute bladder inflammation, there was a predominant infiltrate of polymorphonuclear neutrophils into the bladder. Time-course studies identified early, intermediate, and late genes that were commonly up-regulated by all three stimuli. These genes included: phosphodiesterase 1C, cAMP-dependent protein kinase, iNOS, beta-NGF, proenkephalin B and orphanin, corticotrophin-releasing factor (CRF) R, estrogen R, PAI2, and protease inhibitor 17, NFkB p105, c-fos, fos-B, basic transcription factors, and cytoskeleton and motility proteins. Another cluster indicated genes that were commonly down-regulated by all three stimuli and included HSF2, NF-kappa B p65, ICE, IGF-II and FGF-7, MMP2, MMP14, and presenilin 2. Furthermore, we determined gene profiles that identify the transition between acute and chronic inflammation. During chronic inflammation, the urinary bladder presented a predominance of monocyte/macrophage infiltrate and a concomitant increase in the expression of the following genes: 5-HT 1c, 5-HTR7, beta 2 adrenergic receptor, c-Fgr, collagen 10 alpha 1, mast cell factor, melanocyte-specific gene 2, neural cell adhesion molecule 2, potassium inwardly-rectifying channel, prostaglandin F receptor, and RXR-beta cis-11-retinoic acid receptor. We conclude that microarray analysis of genes expressed in the bladder during experimental inflammation may be predictive of outcome. Further characterization of the inflammation-induced gene expression profiles obtained here may identify novel biomarkers and shed light into the etiology of cystitis.

Mast cell involvement in interstitial cystitis: a review of human and experimental evidence

Interstitial cystitis (IC) is a heterogeneous syndrome of unknown etiology. Altered bladder glycosaminoglycans lining and bladder mastocytosis have been documented in IC. The objective of this article is to critically examine the published data on bladder mastocytosis in clinical, experimental, and animal studies, with particular emphasis on morphologic evidence of mast cell increase and activation. The literature on bladder mastocytosis and mast cell activation in IC is critically reviewed with particular reference to staining methodology, tryptase immunoreactivity, and electron microscopy. Data from humans and animal models of IC are included. Mastocytosis in IC is best documented by tryptase immunocytochemical staining. Standard surgical stains such as Giemsa and toluidine blue routinely underestimate the degree of mastocytosis. Mast cells are 6- to 8-fold higher in the detrusor compared with controls in "classic IC," and 2- to 3-fold higher in "nonulcerative" IC. Detrusor mastocytosis occurs in both classic and nonulcer IC. Mucosal mast cell increase is present in nonulcerative IC. Mast cell activation without typical exocytosis occurs in the mucosa and submucosa. Activation of mast cells, irrespective of bladder location or degree of mastocytosis, is significant. Mast cell-derived vasoactive and proinflammatory molecules may contribute to the pathogenesis of IC.

New agents for the medical treatment of interstitial cystitis

Interstitial cystitis (IC) is a painful, sterile, disorder of the urinary bladder characterised by urgency, frequency, nocturia and pain. IC occurs primarily in women but also in men with recent findings indicating that chronic, abacterial prostatitis may be a variant of this condition. The prevalence of IC has ranged from about 8 - 60 cases/100,000 female patients depending on the population evaluated. About 10% of patients have severe symptoms that are associated with Hunner's ulcers on bladder biopsy; the rest could be grouped in those with or without bladder inflammation. Symptoms of IC are exacerbated by stress, certain foods and ovulatory hormones. Many patients also experience allergies, irritable bowel syndrome (IBS) and migraines. There have been various reports indicating dysfunction of the bladder glycosaminoglycan (GAG) protective layer and many publications showing a high number of activated bladder mast cells. Increasing evidence suggests that neurogenic inflammation and/or neuropathic pain is a major component of IC pathophysiology. Approved treatments so far include intravesical administration of dimethylsulphoxide (DMSO) or oral pentosanpolysulphate (PPS). New treatments focus on the combined use of drugs that modulate bladder sensory nerve stimulation (neurolytic agents), inhibit neurogenic activation of mast cells, or provide urothelial cytoprotection, together with new drugs with anti-inflammatory activity.

Neurokinin-1 (NK-1) receptor is required in antigen-induced cystitis

Interstitial cystitis (IC) is a debilitating disease that has been adversely affecting the quality of women's lives for many years. The trigger in IC is not entirely known, and a role for the sensory nerves in its pathogenesis has been suggested. In addition to inflammation, increased mast cell numbers in the detrusor muscle have been reported in a subset of IC patients. Experimentally, several lines of evidence support a central role for substance P and neurokinin-1 (NK-1) receptors in cystitis. The availability of mice genetically deficient in neurokinin-1 receptor (NK-1R(-/-)) allows us to directly evaluate the importance of substance P in cystitis. An unexpected finding of this investigation is that NK-1R(-/-) mice present increased numbers of mast cells in the bladder when compared with wild-type control mice. Despite the increase in mast cell numbers, no concomitant inflammation was observed. In addition, bladder instillation of wild-type mice with a sensitizing antigen induces activation of mast cells and an acute inflammatory response characterized by plasma extravasation, edema, and migration of neutrophils. Antigen-sensitized NK-1R(-/-) mice also exhibit bladder mast cell degranulation in response to antigen challenge. However, NK-1R(-/-) mice are protected from inflammation, failing to present bladder inflammatory cell infiltrate or edema in response to antigen challenge. This work presents the first evidence of participation of NK-1 receptors in cystitis and a mandatory participation of these receptors on the chain of events linking mast cell degranulation and inflammation.

Interstitial cystitis

Interstitial cystitis (IC) is a multifactorial syndrome with symptoms of pelvic or perineal pain, urinary frequency and urgency. The etiologies are unknown, but several theories have been proposed. Diagnosis is often delayed because most of the conventional evaluation is normal. Pelvic examination is normal except for bladder tenderness. Urodynamics are normal except for increased bladder sensitivity and low capacity. Urinalysis, urine culture and office cystoscopy are also normal. The diagnostic test is cystoscopy under anesthesia with bladder distension. Small submucosal hemorrhages (glomerulations) or ulcers appear after distension. Many empiric treatments have been proposed for IC. None is universally effective, and so treatments are tried sequentially until good symptom relief is achieved. Bladder distension gives excellent (but transient) relief in some patients, especially those with severe bladder inflammation (who also tend to be older). A variety of oral, intravesical and adjunctive treatments are also described.

Interstitial cystitis: a critique of current concepts with a new proposal for pathologic diagnosis and pathogenesis

Interstitial cystitis (IC) has continued to be an unresolved problem in clinical urology despite intense investigation over the past 16 or more years. Its etiology and pathogenesis are still undetermined, and its pathologic diagnosis is essentially one of exclusion, with no specific or clear criteria. In this review, current concepts of the etiology/pathogenesis and pathology are critically analyzed, new pathologic observations summarized, and a proposal of neurogenic inflammation as the primary pathogenetic factor is presented in the context of all currently available information. The popular postulate attributing IC to a deficient or defective glycosaminoglycan urothelial surface layer is not substantiated by morphologic, experimental, clinical, or therapeutic observations. Although the consensus seems to discount an infectious etiology, there is sufficient evidence that a microbial factor-short of a bona fide clinical infection-may have a role. Both autoimmunity and mast cell infiltration also appear to have a role, despite the lack of evidence that either is involved as the primary etiologic factor. Claims that the so-called feline urologic syndrome may represent a natural animal model of IC are shaky. As it now stands, there is no natural or induced animal model that duplicates IC as it occurs in humans. No specific or diagnostic light microscopic pathologic features are provided by either routine histopathology or immunohistochemistry. Increasingly, it has been recognized that detrusor mast cell count has little or no diagnostic value. On the other hand, electron microscopy has provided important new observations: (a) presence of mast cells, activated by piecemeal degranulation, in close proximity to intrinsic nerves-particularly in suburothelium: (b) distinctive pathologic changes in urothelium, suburothelium, and muscularis in biopsy samples obtained after diagnostic bladder hydrodistension; (c) constant associated changes in venules, capillaries, and neural elements in the same biopsy samples; and (d) diffuse involvement of bladder wall, with the most evident and profound pathologic changes in posthydrodistension biopsy samples obtained from cystoscopically obvious lesions (glomerulations). These features are sufficiently distinctive to allow definitive pathologic diagnosis of IC, and provide a firm basis for primary involvement of neurogenic inflammation in its pathogenesis. A proposal is presented regarding the mechanisms invoked by neurogenic inflammation. This proposal revolves around sensory nerve excitation, the release of neuropeptides, and activated differential secretion of potent mast cell mediators. This proposal can account for the heterogeneity and variability of observed pathologic features, and upholds the tacit acceptance of IC as a disease of pluricausal etiology and multifactorial pathogenesis.

Experimental autoimmune cystitis in the Lewis rat: a potential animal model for interstitial cystitis

To develop an autoimmune animal model for interstitial cystitis (IC), we injected rats with Freund's adjuvant (CFA) containing bladder homogenate (experimentals) or CFA alone (shams). We observed a doubling of urinary frequency in the experimental animals over the shams (P = 0.004) and histopathologic changes (venular congestion) consistent with IC. Statistically significant bladder capacity changes were not found. Mast cell (MC) number was not statistically different between experimentals and controls but the number of MCs from section to adjacent section within the same animal's bladder did vary markedly, indicating the MC counts are not a reliable measure of disease in the rat bladder. Splenocytes cultured from the experimental animals and transferred to naive syngeneic recipients were capable of transferring the urinary frequency changes and vascular congestion while splenocytes from animals which did not develop the condition were without effect. In summary, we have developed and autoimmune model for IC consistent with the clinical features of IC. The features of this model can be transferred to naive syngeneic recipients via adoptive splenocyte transfer. The model will permit us to ask and answer important questions about the pathogenesis and treatment of the human disease.

Development of collagenous colitis in a cecoplasty of a patient with interstitial cystitis

We present the case of a 45-yr-old female patient with a 23 yr history of interstitial cystitis that multiple surgical procedures, including a ceco-cystoplasty, were unable to cure. After a cystectomy was performed, histological examination of the bladder showed the development of collagenous colitis. Although the etiology of both interstitial cystitis and collagenous colitis is unknown, this report postulates an association between these two conditions.

Autoantibodies in interstitial cystitis

We have identified and partially characterized autoantibodies from the sera of patients with interstitial cystitis. Our characterization included initial screening by antinuclear antibody testing on human HEp-2 cell substrate and mouse kidney/stomach tissue substrate, titering and subtyping of positive sera, and Western blotting to identify target autoantigens. Of 96 interstitial cystitis patients 35 (36%) were positive for antinuclear antibodies at titers of 1/40 or greater. Among the antinuclear antibody patterns observed 24 were dense fine nuclear speckles, 7 were nucleolar, 3 were mitochondrial and 1 was coarse nuclear speckles. All but 4 of the antinuclear antibody positive sera were exclusively of the IgG class. As determined by unique antinuclear antibody staining patterns and by specificities on Western blots, interstitial cystitis autoantibodies appear to recognize novel autoantigens not previously described in patients with systemic autoimmune diseases, such as lupus, scleroderma and Sjögren's syndrome.