UPK3A+ umbrella cell damage mediated by TLR3-NR2F6 triggers programmed destruction of urothelium in Hunner-type interstitial cystitis/painful bladder syndrome

Urothelial damage and barrier dysfunction emerge as the foremost mechanisms in Hunner-type interstitial cystitis/bladder pain syndrome (HIC). Although treatments aimed at urothelial regeneration and repair have been employed, their therapeutic effectiveness remains limited due to the inadequate understanding of specific cell types involved in damage and the lack of specific molecular targets within these mechanisms. Therefore, we harnessed single-cell RNA sequencing to elucidate the heterogeneity and developmental trajectory of urothelial cells within HIC bladders. Through reclustering, we identified eight distinct clusters of urothelial cells. There was a significant reduction in UPK3A+ umbrella cells and a simultaneous increase in progenitor-like pluripotent cells (PPCs) within the HIC bladder. Pseudotime analysis of the urothelial cells in the HIC bladder revealed that cells faced challenges in differentiating into UPK3A+ umbrella cells, while PPCs exhibited substantial proliferation to compensate for the loss of UPK3A+ umbrella cells. The urothelium in HIC remains unrepaired, despite the substantial proliferation of PPCs. Thus, we propose that inhibiting the pivotal signaling pathways responsible for the injury to UPK3A+ umbrella cells is paramount for restoring the urothelial barrier and alleviating lower urinary tract symptoms in HIC patients. Subsequently, we identified key molecular pathways (TLR3 and NR2F6) associated with the injury of UPK3A+ umbrella cells in HIC urothelium. Finally, we conducted in vitro and in vivo experiments to confirm the potential of the TLR3-NR2F6 axis as a promising therapeutic target for HIC. These findings hold the potential to inhibit urothelial injury, providing promising clues for early diagnosis and functional bladder self-repair strategies for HIC patients. © 2024 The Pathological Society of Great Britain and Ireland.

MIF-Modulated Spinal Proteins Associated with Persistent Bladder Pain: A Proteomics Study

Bladder pain is a prominent symptom in Interstitial Cystitis/Bladder Pain Syndrome (IC/BPS). We studied spinal mechanisms of bladder pain in mice using a model where repeated activation of intravesical Protease Activated Receptor-4 (PAR4) results in persistent bladder hyperalgesia (BHA) with little or no bladder inflammation. Persistent BHA is mediated by spinal macrophage migration inhibitory factor (MIF), and is associated with changes in lumbosacral proteomics. We investigated the contribution of individual spinal MIF receptors to persistent bladder pain as well as the spinal proteomics changes associated with relief of persistent BHA by spinal MIF antagonism. Female mice with persistent BHA received either intrathecal (i.t.) MIF monoclonal antibodies (mAb) or mouse IgG1 (isotype control antibody). MIF antagonism temporarily reversed persistent BHA (peak effect: 2 h), while control IgG1 had no effect. Moreover, i.t. antagonism of the MIF receptors CD74 and C-X-C chemokine receptor type 4 (CXCR4) partially reversed persistent BHA. For proteomics experiments, four separate groups of mice received either repeated intravesical scrambled peptide and sham i.t. injection (control, no pain group) or repeated intravesical PAR4 and: sham i.t.; isotype IgG1 i.t. (15 μg); or MIF mAb (15 μg). L6-S1 spinal segments were excised 2 h post-injection and examined for proteomics changes using LC-MS/MS. Unbiased proteomics analysis identified and relatively quantified 6739 proteins. We selected proteins that showed significant changes compared to control (no pain group) after intravesical PAR4 (sham or IgG i.t. treatment) and showed no significant change after i.t. MIF antagonism. Six proteins decreased during persistent BHA (V-set transmembrane domain-containing protein 2-like confirmed by immunohistochemistry), while two proteins increased. Spinal MIF antagonism reversed protein changes. Therefore, spinal MIF and MIF receptors mediate persistent BHA and changes in specific spinal proteins. These novel MIF-modulated spinal proteins represent possible new targets to disrupt spinal mechanisms that mediate persistent bladder pain.

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.

[The interpretation of the updated American Urological Association guideline of interstitial cystitis/bladder pain syndrome in 2022]

In 2022, American Urological Association updated the guideline for the diagnosis and treatment of interstitial cystitis/bladder pain syndrome (IC/BPS). A significant change has been made in treatment recommendations. The updated guideline no longer divided treatments into first-line through sixth-line tiers. Instead, treatment is categorized into behavioral/non-pharmacologic, oral medicines, bladder instillations, procedures, and major surgery. This change emphasizes the heterogeneity of IC/BPS patients and the importance of individualized treatment, overturns traditional unreasonable ideas about hierarchical and progressive treatment, and encourages patients and physicians to make treatment decisions together. At the same time, the panel emphasized the importance of early implementation of cystoscopy in patients suspected of Hunner lesions and warned against the possibility of pentosan polysulfate causing a unique retinal pigmentary maculopathy. Urinary reconstruction surgery was considered to only be used as a last resort for the treatment of IC/BPS, and there is uncertainty about the overall balance between benefits and risks/burdens. The updated guideline provides a new understanding and decision-making basis for the diagnosis and treatment of IC/BPS. However, it should be noted that the clinical characteristics of Chinese patients should be considered in practice and the application of the guideline should be localized.

Machine Learning-Based Classification of Transcriptome Signatures of Non-Ulcerative Bladder Pain Syndrome

Lower urinary tract dysfunction (LUTD) presents a global health challenge with symptoms impacting a substantial percentage of the population. The absence of reliable biomarkers complicates the accurate classification of LUTD subtypes with shared symptoms such as non-ulcerative Bladder Pain Syndrome (BPS) and overactive bladder caused by bladder outlet obstruction with Detrusor Overactivity (DO). This study introduces a machine learning (ML)-based approach for the identification of mRNA signatures specific to non-ulcerative BPS. Using next-generation sequencing (NGS) transcriptome data from bladder biopsies of patients with BPS, benign prostatic obstruction with DO, and controls, our statistical approach successfully identified 13 candidate genes capable of discerning BPS from control and DO patients. This set was validated using Quantitative Polymerase Chain Reaction (QPCR) in a larger patient cohort. To confirm our findings, we applied both supervised and unsupervised ML approaches to the QPCR dataset. A three-mRNA signature TPPP3, FAT1, and NCALD, emerged as a robust classifier for non-ulcerative BPS. The ML-based framework used to define BPS classifiers establishes a solid foundation for comprehending the gene expression changes in the bladder during BPS and serves as a valuable resource and methodology for advancing signature identification in other fields. The proposed ML pipeline demonstrates its efficacy in handling challenges associated with limited sample sizes, offering a promising avenue for applications in similar domains.

TGF-β inhibitor treatment of H₂O₂-induced cystitis models provides biochemical mechanism for elucidating interstitial cystitis/painful bladder syndrome patients

Interstitial cystitis/painful bladder syndrome (IC/PBS) is a chronic disease for which no effective treatment is available. Transforming growth factor-β (TGF-β) is thought to be involved in the pathogenesis of IC/PBS, and previous studies have suggested that administrations of a TGF-β inhibitor significantly ameliorated IC/PBS in a mouse model. However, the molecular mechanisms underlying the therapeutic effect of a TGF-b inhibitor on IC/PBS has not been comprehensively analyzed. TGF-β has a variety of actions, such as regulation of immune cells and fibrosis. In our study, we induced IC/PBS-like disease in mice by an intravesical administration of hydrogen peroxide (H₂O₂) and examined the effects of three TGF-β inhibitors, Repsox, SB431542, and SB505124, on the urinary functions as well as histological and gene expression profiles in the bladder. TGF-β inhibitor treatment improved urinary function and histological changes in the IC/PBS mouse model, and SB431542 was most effective among the TGF-β inhibitors. In our present study, TGF-β inhibitor treatment improved abnormal enhancement of nociceptive mechanisms, immunity and inflammation, fibrosis, and dysfunction of bladder urothelium. These results show that multiple mechanisms are involved in the improvement of urinary function by TGF-β inhibitor.

Serum anandamide and lipids associated with linoleic acid can distinguish interstitial cystitis/bladder pain syndrome from overactive bladder: An exploratory study

OBJECTIVES

Diagnosing interstitial cystitis/bladder pain syndrome presents a major challenge because it relies on subjective symptoms and empirical cystoscopic findings. A practical biomarker should discriminate diseases that cause increased urinary frequency, particularly overactive bladder. Therefore, we aimed to identify blood biomarkers that can discriminate between interstitial cystitis/bladder pain syndrome and overactive bladder.

METHODS

We enrolled patients with Hunner-type interstitial cystitis (n = 20), bladder pain syndrome (n = 20), and overactive bladder (n = 20) and without lower urinary tract symptoms (controls, n = 15) at Ueda Clinic and Nara Medical University Hospital from February 2020 to August 2021. The degree of interstitial cystitis/bladder pain syndrome symptoms was evaluated using the interstitial cystitis symptom and problem indices. Metabolomics analysis was performed on 323 serum metabolites using liquid chromatography time-of-flight mass spectrometry.

RESULTS

In the Hunner-type interstitial cystitis or bladder pain syndrome group, we observed smaller relative areas, including anandamide, acylcarnitine (18:2), linoleoyl ethanolamide, and arachidonic acid, compared to those in the overactive bladder or control group. Notably, the differences in the relative areas of anandamide were statistically significant (median: 3.950e-005 and 4.150e-005 vs. 8.300e-005 and 9.800e-005), with an area under the curve of 0.9321, demonstrating its ability to discriminate interstitial cystitis/bladder pain syndrome.

CONCLUSIONS

Serum anandamide may be a feasible diagnostic biomarker for interstitial cystitis/bladder pain syndrome. Reduced serum anandamide levels may be associated with pain and inflammation initiation, reflecting the pathology of interstitial cystitis/bladder pain syndrome. Furthermore, our findings suggest that abnormal linoleic acid metabolism may be involved in the pathogenesis of interstitial cystitis/bladder pain syndrome.

Immunogenic Cell Death Associated Molecular Patterns and the Dual Role of IL17RA in Interstitial Cystitis/Bladder Pain Syndrome

The unclear etiology and pathogenesis of interstitial cystitis/bladder pain syndrome (IC/BPS) are responsible for the lack of effective treatment and the poor patient prognosis. Various studies show that chronic inflammation and immune responses are important factors contributing to the pathogenesis of IC/BPS. The process of immunogenic cell death (ICD) involves both the immune response and inflammatory process, and the involvement of ICD in IC/BPS pathogenesis has not been explored. Two IC/BPS transcriptome datasets collected from the Gene Expression Omnibus (GEO) database were used to identify distinct ICD-associated molecular patterns (IAMPs). IAMPs and IC/BPS subtypes were found to be related. The inflammatory immune microenvironments (IIME) in different IAMPs were studied. The potential mechanism by which the interleukin 17 receptor A (IL17RA) influences IC/BPS was examined using in vitro assays. The expression of ICD-related genes (IRGs) was upregulated in IC/BPS bladders, compared with normal bladders. Disease prediction models, based on differentially expressed IRGs, could accurately predict IC/BPS. The IC/BPS patients had two distinct IAMPs, each with its own subtype and clinical features and association with remodeling IIME. IL17RA, a well-established IC/BPS bladder biomarker, mediates both the inflammatory insult and the protective responses. In summary, the current study identified different IAMPs in IC/BPS, which may be involved in the pathogenesis of IC/BPS by remodeling the IIME. The chronic inflammatory process in IC/BPS may be prolonged by IL17RA, which could mediate both pro- and anti-inflammatory responses. The IL17RA-associated pathway may play a significant role in the development of IC/BPS and can be used as a therapeutic target.

Acute Intravesical Capsaicin for the Study of TRPV1 in the Lower Urinary Tract: Clinical Relevance and Potential for Innovation

Capsaicin acts on sensory nerves via vanilloid receptors. TRPV1 has been extensively studied with respect to functional lower urinary tract (LUT) conditions in rodents and humans. We aimed to (1) provide background information on capsaicin and TRPV1 and its mechanisms of action and basis for clinical use, (2) review the use of acute intravesical capsaicin instillation (AICI) in rodents to mimic various LUT disorders in which capsaicin sensitive C-fibers are involved and (3) discuss future innovative treatments. A comprehensive search of the major literature databases until June 2022 was conducted. Both capsaicin-sensitive and resistant unmyelinated bladder afferent C-fibers are involved in non-neurogenic overactive bladder/detrusor overactivity (OAB/DO). AICI is a suitable model to study afferent hyperactivity mimicking human OAB. Capsaicin-sensitive C-fibers are also involved in neurogenic DO (NDO) and potential targets for NDO treatment. AICI has been successfully tested for NDO treatment in humans. Capsaicin-sensitive bladder afferents are targets for NDO treatment. TRPV1-immunoreactive nerve fibers are involved in the pathogenesis of interstitial cystitis/painful bladder syndrome (IC/PBS). The AICI experimental model appears relevant for the preclinical study of treatments targeting bladder afferents for refractory IC/BPS. The activity of capsaicin-sensitive bladder afferents is increased in experimental bladder outlet obstruction (BOO). The AICI model may also be relevant for bladder disorders resulting from C-fiber hyperexcitabilities related to BOO. In conclusion, there is a rationale for the selective blockade of TRPV1 channels for various bladder disorders. The AICI model is clinically relevant for the investigation of pathophysiological conditions in which bladder C-fiber afferents are overexcited and for assessing innovative treatments for bladder disorders based on their pathophysiology.

Comprehensive transcriptome profiling of urothelial cells following TNFα stimulation in an in vitro interstitial cystitis/bladder pain syndrome model

Urothelial cells of the urinary bladder play a critical role in the development and progression of interstitial cystitis/bladder pain syndrome (IC/BPS), a chronic and debilitating inflammatory disease. Given the lack of data on the exact phenotype and function of urothelial cells in an inflammatory setting (as in IC/BPS), we performed the first in-depth characterization of these cells using RNA sequencing, qPCR, ELISA, Western blot, and immunofluorescence. After TNFα stimulation, urothelial cells in the in vitro model of IC/BPS showed marked upregulation of several proinflammatory mediators, such as SAA, C3, IFNGR1, IL1α, IL1β, IL8, IL23A, IL32, CXCL1, CXCL5, CXCL10, CXCL11, TNFAIPR, TNFRSF1B, and BIRC3, involved in processes and pathways of innate immunity, including granulocyte migration and chemotaxis, inflammatory response, and complement activation, as well as TLR-, NOD-like receptor- and NFkB-signaling pathways, suggesting their active role in shaping the local immune response of the bladder. Our study demonstrates that the TNFα-stimulated urothelial cells recapitulate key observations found in the bladders of patients with IC/BPS, underpinning their utility as a suitable in vitro model for understanding IC/BPS mechanisms and confirming the role of TNFα signaling as an important component of the associated pathology. The present study also identifies novel upregulated gene targets of TNFα in urothelial cells, including genes encoding the acute phase protein SAA, complement component C3, and the cytokine receptor IFNGR1, which could be exploited as therapeutic targets of IC/BPS. Altogether, our study provides a reference database of the phenotype of urothelial cells in an inflammatory environment that will not only increase our knowledge of their role in IC/BPS, but also advance our understanding of how urothelial cells shape tissue immunity in the bladder.

Possible role of intravenous administration of mesenchymal stem cells to alleviate interstitial cystitis/bladder pain syndrome in a Toll-like receptor-7 agonist-induced experimental animal model in rat

BACKGROUND

Interstitial cystitis/bladder pain syndrome (IC/BPS) categorized with and without Hunner lesions is a condition that displays chronic pelvic pain related to the bladder with no efficacious treatment options. There are strong associations suggested between Hunner-type IC and autoimmune diseases. Recently, we established an animal model of Hunner-type IC using a Toll-like receptor-7 (TLR7) agonist. Intravenous infusion of mesenchymal stem cells (MSCs) can be used to treat injury via multimodal and orchestrated therapeutic mechanisms including anti-inflammatory effects. Here, we investigated whether infused MSCs elicit therapeutic efficacy associated with the TLR7-related anti-inflammatory pathway in our Hunner-type IC model.

METHODS

Voiding behaviors were monitored 24 h prior to the Loxoribine (LX), which is a TLR7 agonist instillation in order to establish a Hunner-type IC model (from - 24 to 0 h) in female Sprague-Dawley rats. LX was instilled transurethrally into the bladder. At 0 h, the initial freezing behavior test confirmed that no freezing behavior was observed in any of the animals. The LX-instilled animals were randomized. Randomized LX-instilled rats were intravenously infused with MSCs or with vehicle through the right external jugular vein. Sampling tissue for green fluorescent protein (GFP)-positive MSCs were carried out at 48 h. Second voiding behavior tests were monitored from 72 to 96 h. After the final evaluation of the freezing behavior test at 96 h after LX instillation (72 h after MSC or vehicle infusion), histological evaluation with H&E staining and quantitative real-time polymerase chain reaction (RT-PCR) to analyze the mRNA expression levels of inflammatory cytokines were performed.

RESULTS

Freezing behavior was reduced in the MSC group, and voiding behavior in the MSC group did not deteriorate. Hematoxylin-eosin staining showed that mucosal edema, leukocyte infiltration, and hemorrhage were suppressed in the MSC group. The relative expression of interferon-β mRNA in the bladder of the MSC group was inhibited. Numerous GFP-positive MSCs were distributed mainly in the submucosal and mucosal layers of the inflammatory bladder wall.

CONCLUSION

Intravenous infusion of MSCs may have therapeutic efficacy in a LX-instilled Hunner-type IC rat model via a TLR7-related anti-inflammatory pathway.

B6 Mouse Strain: The Best Fit for LPS-Induced Interstitial Cystitis Model

Interstitial cystitis (IC) is a chronic inflammatory disease characterized by bladder pain and increased urinary frequency. Although the C57BL/6J (B6) and FVB/NJ (FVB) mouse strains are commonly used as animal models for studies involving the urinary system, few reports have compared their lower urinary tract anatomy, despite the importance of such data. Our study aimed to characterize bladder function changes in FVB and B6 mouse strains with lipopolysaccharide (LPS)-induced IC, to understand mouse model-based bladder research. The bladder function parameters were measured by cystometrogram. Histological assay was examined by hematoxylin and eosin stain, Masson’s trichrome stain, and immunofluorescence staining. Results indicated that the two strains in the control group exhibited different bladder structures and functions, with significant anatomical differences, including a larger bladder size in the FVB than in the B6 strain. Furthermore, cystometry tests revealed differences in bladder function pressure. LPS-treated B6 mice presented significant changes in peak pressure, with decreased intercontraction intervals; these results were similar to symptoms of IC in humans. Each strain displayed distinct characteristics, emphasizing the care required in choosing the appropriate strain for bladder-model studies. The results suggested that the B6 mouse strain is more suitable for IC models.

Interstitial cystitis/bladder pain syndrome patient is associated with subsequent increased risks of outpatient visits and hospitalizations: A population-based study

Interstitial cystitis/bladder pain syndrome (IC/BPS) is not only a chronic urinary bladder pain syndrome but is also associated with multifactorial etiology. Our study aimed to test the hypothesis that IC/BPS is associated with subsequent increased risks of outpatient visits and hospitalizations. Using nationwide database, the diagnoses were based on the International Classification Codes (ICD-9-CM) (595.1) of at least three outpatient services during 2002-2008, (n = 27,990) and cystoscopic finding Hunner type and/or glomerulation with pre-audit criteria. All recruited cases monitored for subsequent outpatient visits and hospitalizations for 2 years, including all-cause and specialty-specific departments, were classified according to medical specialty and age group (<40, 40-60, ≥60 years of age). IC/BPS patients have more overall outpatient department (OPD) visits and an overall adjusted incidence rate ratio (IRR) of 1.64. As for specialty, IRRs were higher in psychiatry (2.75), Chinese medicine (2.01), and emergency medicine (2.00), besides urology and gynecology. The IRRs decreased as age advanced (2.01, 1.71, and 1.44, respectively), except for gynecology (2.42, 2.52, and 2.81). A similar phenomenon happens in hospitalization with IRR of 1.69. Due to claim data characteristics, whether ulcer type IC/BPS findings can be deductive to non-ulcer type remains inclusive. Current results indicate the impacts of healthcare burden in broad spectrum about IC/PBS patients. IC/BPS has been suggested to be associated with lower threshold of healthcare visits and some coexisting disease and is comprised of systemic dysregulation, and is beyond the scope of local bladder-urethra disease. Adequate recognition of associated or comorbid factors and possible recommendation or referral for IC/BPS patients can help provide better healthcare quality.

Therapeutic effect of modulating the NLRP3-regulated transforming growth factor-β signaling pathway on interstitial cystitis/bladder pain syndrome

Interstitial cystitis/bladder pain syndrome (IC/BPS) is a disorder with complex pathogenesis and lacks effective treatment. Chronic inflammation is the main pathogenesis of Hunner-type IC/BPS. The NLR family pyrin domain-containing 3 (NLRP3) inflammasome-related transforming growth factor-β (TGF-β)/Smad signaling pathway plays a crucial role in inflammation-related tissue fibrosis. Lipopolysaccharide (LPS) and protamine sulfate (LPS/PS) were instilled into the mouse bladder twice a week for 5 consecutive weeks to establish a chronic inflammation-induced IC/BPS model (LPS/PS model). Following LPS/PS treatment, curcumin (oral, 100 mg/kg; a potent NLRP3 modulator) was administered for 2 weeks in the curcumin treatment group, and normal saline was used for the sham group. Bladder function was evaluated by performing the voiding spot assay and examining the status of urothelial denudation and fibrosis in bladder tissues. The expression of NLRP3 inflammasome, interleukin-1β, TGF-β, Smad, vimentin, and E-cadherin in bladder tissues was evaluated through immunohistochemistry staining. Results revealed that the repeated instillation of LPS/PS leads to voiding dysfunction, bladder urothelium denudation, and detrusor muscle fibrosis through the upregulation of the NLRP3 inflammasome/IL-1β-related TGF-β/Smad pathway and the increased epithelial-mesenchymal transition process in bladder tissues. The downregulation of the NLRP3 inflammasome/IL-1β-related TGF-β/Smad pathway in bladder tissues through curcumin effectively mitigated bladder injury in the LPS/PS model. In conclusion, the NLRP3 inflammasome/IL-1β-related TGF-β/Smad pathway plays a crucial role in bladder injury in the LPS/PS model, and modulation of this pathway, such as by using curcumin, can effectively mitigate the sequelae of chronic inflammation-induced IC/BPS.

Monotypic Plasma Cell Proliferation of Uncertain Clinical Significance Mimicking Interstitial Cystitis: An Early Lesion of MALT Lymphoma?

We prospectively studied our institutional experience of bladder extranodal marginal zone (mucosa-associated lymphoid tissue [MALT]) lymphoma including bladder biopsies in which the possibility of MALT lymphoma was considered. We identified a subset of cases primary to the urinary bladder, presenting with prominent plasma cell infiltrates and symptoms mimicking bladder pain syndrome/interstitial cystitis. These proliferations were designated for this study as "monotypic plasma cell proliferation of uncertain clinical significance" (MPCP-US), as the features were insufficient for diagnosis of MALT lymphoma. We identified 33 patients, consisting of 22 cases of MPCP-US (6 of which were associated with amyloid deposition) and 11 cases of MALT lymphoma. MPCP-US was more prevalent in men (73%), a mass lesion was not identified at cystoscopy, and only 1 case had an accompanying urinary tract infection (4.5%). Histologically, MPCP-US presented as monotypic plasma cells arranged in a superficial band-like distribution in the lamina propria, predominantly kappa restricted (68%) and IgA+ or IgM+ (64% and 23%, respectively) and without a histologic mass of atypical B cells or plasma cells, not diagnostic for established MALT lymphoma or plasmacytoma. Secondary involvement of the bladder by other lymphoproliferative disorders was excluded and there was no evidence of progressive disease. MALT lymphomas are presented for comparison and our analysis demonstrated that MPCP-US represent a different clinicopathologic entity compared with classic MALT lymphoma. We present the first series of cases of MPCP-US. The recognition of this entity is fundamental to the development of management protocols to relieve intractable symptoms mimicking bladder pain syndrome/interstitial cystitis in these patients.

Gabapentin reduces painful bladder hypersensitivity in rats with lipopolysaccharide-induced chronic cystitis

Although interstitial cystitis/bladder pain syndrome (IC/BPS) is a chronic condition causing bladder pain and urinary symptoms, effective treatments have not been established. The aim of this study was to adapt a chronic cystitis model in rats using lipopolysaccharide (LPS), which reflects IC/BPS pathology, and characterize the model's histological and behavioral effects. Furthermore, we investigated the effect of an α2 δ subunit ligand, gabapentin (GBP), on bladder hypersensitivity of rats with chronic cystitis. Cystitis models were created by repeated intravesical injections of LPS. In the histological examination, the LPS-injected group had greater inflammatory response, fibrosis, and abnormally thick re-epithelialization. In the LPS-injected group, LPS prompted hyperalgesia in both the lower abdomen and hind paw regions after day 1 of the first injection compared with the saline-injected controls, without any recovery for 21 days at least. During cystometry, the LPS-injected group showed bladder hyperactivity at all times. Systemic administration of GBP reduced cystitis-related pain due to chronic inflammation and reduced the increased frequency of voiding in the LPS-injected group. These results suggest that repeated intravesical injections of LPS induce long-lasting bladder inflammation, pain, and overactivity in rats, while GBP is effective in the management of those symptoms in this chronic cystitis model. The current study identifies a relatively simple method to develop an animal model for chronic cystitis and provides evidence that GBP may be an effective treatment option for patients with IC/BPS.

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.

In vivo and ex vivo assessment of bladder hyper-permeability and using molecular targeted magnetic resonance imaging to detect claudin-2 in a mouse model for interstitial cystitis

OBJECTIVES

To determine if the URO-MCP-1 mouse model for bladder IC/BPS is associated with in vivo bladder hyper-permeability, as measured by contrast-enhanced MRI (CE-MRI), and assess whether molecular-targeted MRI (mt-MRI) can visualize in vivo claudin-2 expression as a result of bladder hyper-permeability. Interstitial cystitis/bladder pain syndrome (IC/BPS) is a chronic, painful condition of the bladder that affects primarily women. It is known that permeability plays a substantial role in IC/BPS. Claudins are tight junction membrane proteins that are expressed in epithelia and endothelia and form paracellular barriers and pores that determine tight junction permeability. Claudin-2 is a molecular marker that is associated with increased hyperpermeability in the urothelium.

MATERIALS AND METHODS

CE-MRI was used to measure bladder hyper-permeability in the URO-MCP-1 mice. A claudin-2-specific mt-MRI probe was used to assess in vivo levels of claudin-2. The mt-MRI probe consists of an antibody against claudin-2 conjugated to albumin that had Gd-DTPA (gadolinium diethylenetriamine pentaacetate) and biotin attached. Verification of the presence of the mt-MRI probe was done by targeting the biotin moiety for the probe with streptavidin-horse radish peroxidase (SA-HRP). Trans-epithelial electrical resistance (TEER) was also used to assess bladder permeability.

RESULTS

The URO-MCP-1 mouse model for IC/BPS was found to have a significant increase in bladder permeability, following liposaccharide (LPS) exposure, compared to saline-treated controls. mt-MRI- and histologically-detectable levels of the claudin-2 probe were found to increase with LPS -induced bladder urothelial hyper-permeability in the URO-MCP-1 IC mouse model. Levels of protein expression for claudin-2 were confirmed with immunohistochemistry and immunofluorescence imaging. Claudin-2 was also found to highly co-localize with zonula occlidens-1 (ZO-1), a tight junction protein.

CONCLUSION

The combination of CE-MRI and TEER approaches were able to demonstrate hyper-permeability, a known feature associated with some IC/BPS patients, in the LPS-exposed URO-MCP-1 mouse model. This MRI approach could be clinically translated to establish which IC/BPS patients have bladder hyper-permeability and help determine therapeutic options. In addition, the in vivo molecular-targeted imaging approach can provide invaluable information to enhance our understanding associated with bladder urothelium hyper-permeability in IC/BPS patients, and perhaps be used to assist in developing further therapeutic strategies.

Relevance of the Endoscopic Evaluation in the Diagnosis of Bladder Pain Syndrome/Interstitial Cystitis

OBJECTIVE

To assess the relevance of the endoscopic evaluation in clinically suspected cases of Bladder Pain Syndrome/Interstitial Cystitis (BPS/IC), using ESSIC criteria, established in 2008 by the European Society for the Study of Interstitial Cystitis (ESSIC).

METHODS

We included all patients who underwent endoscopic evaluation between January 01, 2015 and October 31, 2019 for clinical suspicion of BPS/IC. Collected data included demographic and baseline clinical features, endoscopic appearance (prior and after hydrodistension), and bladder wall biopsy results, both defined according to ESSIC criteria. Data were cross tabulated to define ESSIC phenotypes, while subgroups and multivariate analyses were carried out to assess the influence of clinical variables on ESSIC phenotypes.

RESULTS

Fifty-two subjects were included, mainly women (92%). Median age at evaluation was 45 (32.9-58.2) years. At hydrodistension, 21 patients (42%) had positive and 29 (58%) had negative findings. Grade 2-3 glomerulations were found in 18 patients, while Hunner lesions were reported only in 1 patient. Positive results at biopsy were found in 24 pts (51.1%), while negative in 23 (48.9%). Overall, the positive and negative concordance between hydrodistension and biopsy results was 78%. No significant differences in ESSIC subtypes were found after stratification based on clinical features and at multivariate analysis. Retrospective design is the main limitation.

CONCLUSION

Cystoscopy with hydrodistension and biopsy do have a role in the diagnostic pathway of BPS/IC. However, results should be considered in the clinical context of the individual patient.

Experimental Cannabinoid 2 Receptor Activation by Phyto-Derived and Synthetic Cannabinoid Ligands in LPS-Induced Interstitial Cystitis in Mice

Interstitial cystitis (IC) is a chronic bladder disorder with unclear etiology. The endocannabinoid system has been identified as a key regulator of immune function, with experimental evidence for the involvement of cannabinoid receptors in bladder inflammation. This study used intravital microscopy (IVM) and behavioral testing in lipopolysaccharide-induced IC, to investigate the anti-inflammatory analgesic effects of a natural dietary sesquiterpenoid, beta-caryophyllene (BCP), which is present in cannabis among other plants, and has reported agonist actions at the cannabinoid 2 receptor (CB₂R). BCP’s anti-inflammatory actions were compared to the synthetic CB₂R-selective cannabinoid, HU308, and to an FDA-approved clinical treatment (dimethyl sulfoxide: DMSO). IVM data revealed that intravesical instillation of BCP and/or HU308 significantly reduces the number of adhering leukocytes in submucosal bladder venules and improves bladder capillary perfusion. The effects of BCP were found to be comparable to that of the selective CB₂R synthetic cannabinoid, HU308, and superior to intravesical DMSO treatment. Oral treatment with BCP was also able to reduce bladder inflammation and significantly reduced mechanical allodynia in experimental IC. Based on our findings, we believe that CB₂R activation may represent a viable therapeutic target for IC, and that drugs that activate CB₂R, such as the generally regarded as safe (GRAS) dietary sesquiterpenoid, BCP, may serve as an adjunct and/or alternative treatment option for alleviating symptoms of inflammation and pain in the management of IC.

Patterns and predictors of Hunner lesion recurrence in patients with interstitial cystitis

AIMS

To evaluate the patterns and predictive factors associated with Hunner lesions (HLs) recurrence in patients with interstitial cystitis (IC).

METHODS

This study was a retrospective analysis of data from patients with IC who underwent transurethral resection and cauterization (TUR-C) of HLs between October 2011 and December 2017. Symptoms were evaluated using the Pelvic Pain and Urgency/Frequency Patient Symptom Scale (PUF), O'Leary-Sant Interstitial Cystitis Symptom Index, and Visual Analogue Scale (VAS). Patients attended follow-up visits every 3 months; cystoscopy was performed immediately in patients with aggravated symptoms. Recurrence was defined as a VAS score greater than or equal to 4 and HLs recurrence on cystoscopy.

RESULTS

A total of 91 patients were enrolled (25 male, 66 female): median follow-up was 30.6 months. HLs recurrence occurred in 101 sites (53 patients), 21.8% in the previous TUR-C site, 18.8% de novo, and 59.4% at both previous and de novo sites. The recurrence rate was approximately 12.7%, 40%, and 55.2% at 6, 12, and 18 months, respectively. A higher PUF bother score was the only predictive factor of recurrence (odds ratio: 1.142, 95% confidence interval: 1.016-1.284, P = 0.026), with a cut-off value of 7.5 (sensitivity: 67.9%, specificity: 62.5%). In case of late recurrence (>18 months), there was no predictive factor.

CONCLUSIONS

The HLs recurrence pattern was unpredictable, involving both previous TUR-C and de novo areas. More accurately defining the HLs resection margin may lead to better surgical outcomes but this remains to be proven.

Interstitial cystitis: elements of diagnosis and place of histopathological examination. About 16 cases

BACKGROUND

Interstitial cystitis (IC) is a rare disease, of difficult diagnosis. The diagnostic utility of histopathological examination of bladder biopsy remains controversial.

AIM

We conducted a retrospective study to assess the frequency of interstitial cystitis, to analyze its clinical presentation and the data from the paraclinical examinations. We discuss the steps and criteria of diagnosis, as well as the place of histopathological examination for diagnosis.

METHODS

Sixteen patients diagnosed with IC were followed in the Urology Department of the Sahloul University Hospital between 1996 and 2013. The diagnosis was suggested by clinical history and confirmed on the basis of clinical symptoms and results of the paraclinical explorations: urodynamic assessment, cystoscopy and bladder biopsy.

RESULTS

Six men (37.5%) and ten women (62.5%), with an average age of 56 years complained of pelvic pain and urination disorders for two years on average before the diagnosis. The urodynamic study found decreased bladder compliance in 13 cases and bladder instability in nine cases. Cystoscopy demonstrated inflammatory mucosa in 13 patients (81%). Histologically, the classic ulcerative form accounted for 50% of the cases. The number of mast cells was high in both the mucosa and the muscular in 12 cases, both in the classical and non-ulcerative forms.

CONCLUSION

The IC remains a diagnosis of exclusion. The first line of diagnosis is patient selection based on symptoms and an exclusion of diseases with similar presentation. Vesical biopsy is useful for confirmation and classification of the disease.

Electron microscopic characteristics of interstitial cystitis/bladder pain syndrome and their association with clinical condition

Background

Electron microscopy (EM) characteristics of the urothelium in interstitial cystitis/bladder pain syndrome (IC/BPS) and their association with clinical condition are unclear.

Methods

Ten IC/BPS patients who were admitted for hydrodistention and 5 patients with stress urinary incontinence (control patients) were enrolled. All patients provided detailed clinical histories and underwent urodynamic studies. Cystoscopic bladder biopsies were obtained and processed for transmission EM (TEM) and scanning EM (SEM). The severity of the urothelium findings was graded on a 4-point scale (0: none, 1: mild, 2: moderate, and 3: severe). The EM findings between IC/BPS and control patients were compared; the results were analyzed using the chi-square test.

Results

Compared with the urothelium of control patients, the urothelium of IC/BPS patients had more severe defects of the urothelial cell layers and integrity of umbrella cells in TEM (p = 0.045 and 0.01, respectively). In SEM, umbrella cell pleomorphism increased and microplicae of the cell membrane decreased in the IC/BPS group, and both were more severe than in the control group (p = 0.022 and 0.007, respectively). The patients with moderate to severe defects of umbrella cell integrity had more severe bladder pain and smaller maximal bladder capacity (MBC) (both p = 0.010). Patients with moderate to severe defects in microplicae of the cell membrane had smaller cystometric bladder capacity and MBC (p = 0.037 and 0.047, respectively).

Conclusions

The results revealed significant urothelium defects in IC/BPS, especially in the umbrella cells. Defects of umbrella cells may play an important role in the pathogenesis of IC/BPS.

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.

Apoptotic effect as biomarker of disease, severity and follow-up in interstitial cystitis

OBJECTIVE

To determine whether the apoptotic effect test could serve as a biomarker of severity in bladder pain syndrome/interstitial cystitis.

MATERIAL AND METHODS

A prospective study was conducted between January 2010 and January 2015, which included 57 patients diagnosed with interstitial cystitis and 49 diagnosed with chronic pelvic pain of gynaecological origin. The urine was exposed to cell cultures, and the urine's capacity for inducing apoptosis in the cultures was analysed. A statistical analysis was then conducted to assess whether the apoptotic effect was associated with the symptoms.

RESULTS

After performing an analysis of the association between the degree of apoptotic effect and the symptoms of patients with interstitial cystitis, we observed a significant increase in the mean percentages of apoptosis as the degree of symptom severity increased. After analysing the association between the apoptotic effect and symptoms, we obtained a positive correlation in the patients with interstitial cystitis and a lack of correlation in the patients with chronic pelvic pain of gynaecological origin. The rates of apoptosis increased progressively in the patients with interstitial cystitis as the symptoms increased, while the patients with chronic pelvic pain of gynaecological origin remained stable.

CONCLUSIONS

The apoptotic effect of the urine of patients with interstitial cystitis could be a marker of disease, thus differentiating patients with interstitial cystitis from patients with chronic pelvic pain. The effect could also provide an objective measure of symptom severity.

Interstitial Cystitis: An uncommon revelation in primitive Sjögren syndrome

Interstitial cystitis is an exceptional entity during primary Sjögren's syndrome. In this regard, we report the case of a 67-year-old patient in whom initially idiopathic interstitial cystitis revealed primary Sjögren's syndrome after 5 years of evolution in front of xerostomiaa, xerophtalmia and bilateral parotid hypertrophy with histological confirmation at the biopsy of accessory salivary glands.

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-1β, 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.

Nociceptin/orphanin FQ receptor expression in clinical pain disorders and functional effects in cultured neurons

The nociceptin/orphanin FQ peptide receptor (NOP), activated by its endogenous peptide ligand nociceptin/orphanin FQ (N/OFQ), exerts several effects including modulation of pain signalling. We have examined, for the first time, the tissue distribution of the NOP receptor in clinical visceral and somatic pain disorders by immunohistochemistry and assessed functional effects of NOP and μ-opioid receptor activation in cultured human and rat dorsal root ganglion (DRG) neurons. Quantification of NOP-positive nerve fibres within the bladder suburothelium revealed a remarkable several-fold increase in detrusor overactivity (P < 0.0001) and painful bladder syndrome patient specimens (P = 0.0014) compared with controls. In postmortem control human DRG, 75% to 80% of small/medium neurons (≤50 μm diameter) in the lumbar (somatic) and sacral (visceral) DRG were positive for NOP, and fewer large neurons; avulsion-injured cervical human DRG neurons showed similar numbers. NOP immunoreactivity was significantly decreased in injured peripheral nerves (P = 0.0004), and also in painful neuromas (P = 0.025). Calcium-imaging studies in cultured rat DRG neurons demonstrated dose-dependent inhibition of capsaicin responses in the presence of N/OFQ, with an IC50 of 8.6 pM. In cultured human DRG neurons, 32% inhibition of capsaicin responses was observed in the presence of 1 pM N/OFQ (P < 0.001). The maximum inhibition of capsaicin responses was greater with N/OFQ than μ-opioid receptor agonist DAMGO. Our findings highlight the potential of NOP agonists, particularly in urinary bladder overactivity and pain syndromes. The regulation of NOP expression in visceral and somatic sensory neurons by target-derived neurotrophic factors deserves further study, and the efficacy of NOP selective agonists in clinical trials.

Effects of hyperbaric oxygen therapy on hydrochloric acid-induced interstitial cystitis in rats: a histological and ultrastructural study

INTRODUCTION

Currently no definitive cure exists for interstitial cystitis (IC). We investigated the therapeutic effects of hyperbaric oxygen (HBO₂) therapy in this syndrome in an experimental IC model through biochemical analyses and histopathological assessments.

METHODS

24 Sprague Dawley rats were divided into three treatment groups sham (transurethral intravesical injection with sterile distilled water), rats with IC (induced by transurethral intravesical injection with hydrochloric acid), and rats with IC + HBO₂. After completion of experiments the animals were sacrificed and their urinary bladders were removed surgically. Tissues were evaluated by light and electron microscopy. Lesion index scoring system for IC was used to evaluate vesical injury. TNF-α levels were measured by ELISA test kit.

RESULTS

Lesion index scores and TNF-α levels of the sham and IC + HBO₂ treatment groups were quite similar (p < 0.01). Although HBO₂ treatment did not show any effect in reducing the number of mast cells (p > 0.05), it reduced the mast cell activity (p < 0.05). All parameters except mitochondrial damage (p > 0.05) were improved in the IC + HBO₂ treatment group compared to the IC without HBO₂ treatment group.

CONCLUSION

HBO₂ treatment may alleviate the inflammation, may lead to a certain degree of reversal of adverse histopathological changes, and is effective in enhancing the healing process in interstitial cystitis. We believe that HBO₂ treatment may be included as a weapon in our armamentarium against IC.

In the absence of overt urothelial damage, chondroitinase ABC digestion of the GAG layer increases bladder permeability in ovariectomized female rats

Loss of integrity of the protective impermeability barrier in the urothelium has been identified as significant in bladder dysfunction. In this study, we tested the theory that the luminal layer of glycosaminoglycans (GAG) serves as an important component of barrier function. The peptide polycation protamine sulfate (PS), 1 mg/ml, was instilled intravesically for 10 min into rat bladders. Chondroitinase ABC (ChABC), 63 IU/ml, was instilled into an additional six rats for 30 min to digest the GAG layer. Unmanipulated controls and sham-injected controls were also performed. After 24 h, the rats were euthanized, the bladders were removed, and permeability was assessed in the Ussing chamber and by diffusion of FITC-labeled dextran (4 kDa) to measure macromolecular permeability. The status of tight junctions was assessed by immunofluorescence and electron microscopy. In control and sham treated rat bladders, the transepithelial electrical resistance were means of 2.5 ± 1.1 vs. 2.6 ± 1.1 vs 1.2 ± 0.5 and 1.01 ± 0.7 kΩ·cm(2) in the PS-treated and ChABC-treated rat bladders (P = 0.0016 and P = 0.0039, respectively). Similar differences were seen in dextran permeability. Histopathology showed a mild inflammation following PS treatment, but the ChABC-treated bladders were indistinguishable from controls. Tight junctions generally remained intact. ChABC digestion alone induced bladder permeability, confirming the importance of the GAG layer to bladder barrier function and supports that loss of the GAG layer seen in bladder biopsies of interstitial cystitis patients could be a significant factor producing symptoms for at least some interstitial cystitis/painful bladder syndrome patients.

Impaired Expression of Prostaglandin E2 (PGE2) Synthesis and Degradation Enzymes during Differentiation of Immortalized Urothelial Cells from Patients with Interstitial Cystitis/Painful Bladder Syndrome

Purpose

The differentiated superficial cells of the urothelium restrict urine flow into the bladder wall. We have demonstrated that urothelial cells isolated from bladders of patients with interstitial cystitis/painful bladder syndrome (IC/PBS) fail to release PGE₂ in response to tryptase. This study examines the expression of PGE₂ synthesis and degradation enzymes in urothelial cells during differentiation.

Materials and Methods

We measured immunoprotein expression of cyclooxygenase-2 (COX-2), prostaglandin E₂ synthase (PGES) and 15-hydroxyprostaglandin dehydrogenase (PGDH) in human urothelial cells and in immortalized urothelial cells isolated from the bladders of IC/PBS patients or normal subjects during stratification and differentiation produced by increased calcium and fetal bovine serum (Ca/FBS) in the culture medium for 1, 3 and 7 days.

Results

PGES immunoprotein expression increased during differentiation in normal and IC/PBS urothelial cells. COX-2 expression also increased in cells from normal patients following differentiation. Remarkably, no COX-2 expression was detectable in urothelial cells isolated from 3 out of 4 IC/PBS patients. PGDH immunoprotein expression decreased in normal cells after 1 and 3 days of Ca/FBS addition, but returned to normal after 7 days. PGDH expression was unchanged during differentiation at 1 and 3 days, but was more than 2-fold higher at 7 days compared to day 0 in the IC/PBS cells. Urothelial cells isolated from IC/PBS patients demonstrated no PGE₂ release in response to tryptase under any of the experimental conditions studied.

Conclusions

Taken together, our results indicate that PGE₂ release is compromised during stratification and differentiation in IC/PBS urothelium and may contribute to impaired barrier function.

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.

Morphometric and quantitative immunohistochemical analysis of disease-related changes in the upper (suburothelial) lamina propria of the human bladder dome

The upper (suburothelial) lamina propria (ULP) is a distinct region in the human bladder with dense populations of interstitial cells (IC), fine vascular networks and variable development of muscularis mucosae (MM). It is more and more obvious that the ULP plays an important role in bladder physiology and bladder disease, and in the present study we have quantified changes in the cellular key players of the ULP in bladders from patients with carcinoma in situ (CIS), multiple sclerosis (MS) and bladder pain syndrome (BPS). Tissue samples for the different patient groups were obtained from radical cystectomy-specimens. Standardized immunohistochemistry with a panel of specific cell markers was used to characterise the ULP cellular structures, followed by digitalised morphometry and quantitative staining analysis. Alterations in the ULP area were most pronounced in MS bladders, but also present in BPS and CIS bladders. We observed an increased thickness and increased variability in thickness of the ULP IC area in MS and BPS bladders; a significantly increased development of MM in MS bladders; a changed organization of vascular plexuses in the lamina propria in most pathologic bladders and a changed phenotype of ULP IC: a significantly decreased expression of progesterone receptor in MS bladders and a trend towards decreased expression of alpha-smooth muscle actin in BPS bladders. We show here for the first time the presence of disease-specific changes in organisation and/or phenotype of the different key players of the ULP area in human bladder. The present findings further support the hypothesis that the ULP area is involved and altered in different bladder diseases.

Are mast cells still good biomarkers for bladder pain syndrome/interstitial cystitis?

PURPOSE

ESSIC identifies mast cell infiltrates of detrusor muscle as a diagnostic criterion for bladder pain syndrome/interstitial cystitis. However, an increased mast cell count is also characteristic of overactive bladder syndrome. The lack of uniformity in mast cell detection methods hampers data comparison. Using state-of-the-art techniques we investigated whether mast cells differ among bladder conditions.

MATERIALS AND METHODS

We analyzed bladder biopsies from 56 patients, including 31 with bladder pain syndrome/interstitial cystitis with (12) or without (19) Hunner lesions, 13 with overactive bladder syndrome and 12 without bladder symptoms to determine the quantity, location, distribution and activation of mast cells using immunohistochemistry with anti-mast cell tryptase. Patients were allocated to study groups by key bladder symptoms commonly used to define conditions (pain and major urgency).

RESULTS

Subepithelial mast cell localization (p <0.001) and an increased detrusor mast cell count (p = 0.029) were characteristic of bladder pain syndrome/interstitial cystitis with Hunner lesions. The optimal cutoff of 32 detrusor mast cells per mm(2) achieved only 68% accuracy with 38% positive predictive value. No difference was observed between bladder pain syndrome/interstitial cystitis without Hunner lesions and overactive bladder syndrome. Patient groups differed in lymphocyte infiltration (p = 0.001), nodular lymphocyte aggregates (p <0.001) and urothelium integrity (p <0.001).

CONCLUSIONS

Subepithelial mast cell distribution was characteristic of bladder pain syndrome/interstitial cystitis with Hunner lesions. Detrusor mastocytosis had poor predictive value for bladder pain syndrome/interstitial cystitis. Mast cell assessment did not distinguish bladder pain syndrome/interstitial cystitis without Hunner lesions from overactive bladder syndrome.

Corticotropin-releasing factor family peptide signaling in feline bladder urothelial cells

Corticotropin-releasing factor (CRF) plays a central role in the orchestration of behavioral and neuroendocrine responses to stress. The family of CRF-related peptides (CRF and paralogs: urocortin (Ucn)-I, -II, and -III) and associated receptors (CRFR1 and CRFR2) are also expressed in peripheral tissues such as the skin and gastrointestinal tract. Local signaling may exert multiple effects of stress-induced exacerbation of many complex syndromes, including psoriasis and visceral hypersensitivity. Interstitial cystitis/painful bladder syndrome (IC/PBS), a chronic visceral pain syndrome characterized by urinary frequency, urgency, and pelvic pain, is reported to be exacerbated by stress. Functional changes in the epithelial lining of the bladder, a vital blood-urine barrier called the urothelium, may play a role in IC/PBS. This study investigated the expression and functional activity of CRF-related peptides in the urothelium of normal cats and cats with feline interstitial cystitis (FIC), a chronic idiopathic cystitis exhibiting similarities to humans diagnosed with IC/PBS. Western blots analysis showed urothelial (UT) expression of CRFR1 and CRFR2. Enzyme immunoassay revealed release of endogenous ligands (CRF and Ucn) by UT cells in culture. Evidence of functional activation of CRFR1 and CRFR2 by receptor-selective agonists (CRF and UCN3 respectively) was shown by i) the measurement of ATP release using the luciferin-luciferase assay and ii) the use of membrane-impermeant fluorescent dyes (FM dyes) for fluorescence microscopy to assess membrane exocytotic responses in real time. Our findings show evidence of CRF-related peptide signaling in the urothelium. Differences in functional responses between FIC and normal UT indicate that this system is altered in IC/PBS.

Health care service utilization among patients with bladder pain syndrome/interstitial cystitis in a single payer healthcare system

Background

This study aims to investigate the differences in the utilization of healthcare services between patients with bladder pain syndrome/interstitial cystitis (BPS/IC) and patients without using a population-based database in Taiwan.

Methods

This study comprised of 350 patients with BPS/IC and 1,750 age-matched controls. Healthcare resource utilization was evaluated in the one-year follow-up period as follows: number of outpatient visits and inpatient days, and the mean costs of outpatient and inpatient treatment. A multivariate regression analysis was used to evaluate the relationship between BPS/IC and total costs of health care services.

Results

For urological services, patients with BPS/IC had a significantly higher number of outpatient visits (2.5 vs. 0.2, p<0.001) as well as significantly higher outpatient costs ($US166 vs. $US6.8, p<0.001) than the controls. For non–urologic services, patients with BPS/IC had a significantly high number of outpatient visits (35.0 vs. 21.3, p<0.001) as well as significantly higher outpatient cots ($US912 vs. $US675, p<0.001) as compared to the controls. Overall, patients with BPS/IC had 174% more outpatient visits and 150% higher total costs than the controls. Multiple-regression-analyses also showed that the patients with BPS/IC had significantly higher total costs for all healthcare services than the controls.

Conclusions

This study found that patients with BPS/IC have a significantly higher number of healthcare related visits, and have significantly higher healthcare related costs than age-matched controls. The high level of healthcare services utilization accrued with BPS/IC was not necessarily exclusive for BPS/IC, but may have also been associated with medical co-morbidities.

Podoplanin (D2-40) is a reliable marker of urinary bladder myofibroblasts (telocytes)

Podoplanin, D2-40, has been described in a variety of normal and neoplastic tissues. It is often used for highlighting lymphatics. We evaluated the expression of podoplanin in α-smooth muscle actinpositive myofibroblasts producing the suburothelial layer in tunica propria of the urinary bladder that have some similar features with telocytes. Our results showed that these cells demonstrate distinct D2-40 immunoreactivity from telocytes occurring in the renal pelvis and ureter. We observed positive reaction not only in bioptic specimens from women with interstitial cystitis, but also in a control group of women and men treated for pathological bladder lesion different from interstitial cystitis. It is interesting that identical staining reaction was observed in the ureters only exceptionally. In addition, we examined samples from myofibroblastic tumoriform lesions of soft tissue such as nodular fascitis and fibromatosis (desmoid) and we obtained negative results. It means that the so-called myofibroblasts of urinary bladder tunica propria have a unique immunophenotype that has probably not been described until now. Our findings suggest that D2-40 can be used as a complementary immunostainer to α-smooth muscle actin on urinary bladder biopsies from patients with interstitial cystitis. The role of D2-40 as an immunohistochemical marker is still being investigated.

Local immune response in bladder pain syndrome/interstitial cystitis ESSIC type 3C

INTRODUCTION AND HYPOTHESIS

Bladder pain syndrome/interstitial cystitis (BPS/IC) is identified based on subjective symptoms which lead to heterogeneous patient populations. Previous studies using gene expression arrays for BPS/IC with Hunner's lesions [European Society for the Study of Interstitial Cystitis (ESSIC) type 3C], a subtype of the condition discernible by cystoscopy, have revealed characteristic immune responses and urothelial abnormalities. This current study aimed to further characterize this subtype using a gene expression panel. We hypothesized that B-cell activation with high levels of urinary antibody concentration would be found.

METHODS

Cold-cup bladder biopsies, catheterized urine and blood were collected from 15 BPS/IC ESSIC type 3C patients, 11 non-inflammatory overactive bladder (OAB) patients and eight healthy controls. Gene expression in biopsies was quantified by real-time quantitative polymerase chain reaction (RT-qPCR), immunohistochemistry was performed on bladder tissue and urinary immunoglobulins G and A were quantified by enzyme-linked immunosorbent assay. Statistical analyses included the Kruskal-Wallis test for non-parametric data and post hoc tests identified differences between groups.

RESULTS

High expression of T- and B-cell markers (CTLA4, CD20, CD79A, IGH@), low expression of urothelial markers (KRT20, UPK1B, UPK3A), focal lymphoid aggregates in the submucosa and high immunoglobulin concentration in urine were found exclusively in BPS/IC ESSIC type 3C patients. Results for OAB were in intermediate ranges between the other two groups and UPK1B even reached significantly lower expression when compared to healthy controls.

CONCLUSIONS

BPS/IC ESSIC type 3C is characterized by a local adaptive immune response with elevated urinary antibody concentrations. Quantification of urinary immunoglobulin levels could be used for a non-invasive diagnosis of BPS/IC ESSIC type 3C.

[The role of immunomodulating therapy in the treatment and prevention of exacerbations of chronic cystitis]

The article presents the results of the examination and treatment of 60 women with chronic cystitis aged 20 to 80 years. The mean disease duration was 4,9 years (ranged from 6 months to 40 years). Immunomodulator Tilorone was included in the complex therapy of 30 patients of the main group. Besides the standard examination, immunological studies, including the definition of netrophil phagocytic rates in the patients were performed. It was revealed that the inclusion of immunomodulator in the treatment regimen of exacerbations of chronic cystitis contributes to an increase of index of activation of neutrophil phagocytic reserve, significant reduction in the frequency of exacerbations of the disease after the basic and preventive courses of treatment.

Intravesical botulinum toxin a injections do not benefit patients with ulcer type interstitial cystitis

BACKGROUND

Ulcer type and non-ulcer type interstitial cystitis/bladder pain syndromes (IC/BPS) are considered different disease entities. Thus, intravesical botulinum toxin A (BoNT-A) treatment outcomes could differ for each entity.

OBJECTIVES

To evaluate and compare the treatment outcomes of BoNT-A injections for treatment of each IC/BPS type.

STUDY DESIGN

Prospective interventional study.

SETTING

Tertiary medical center affiliated with Buddhist Tzu Chi General Hospital and Tzu Chi University, Taiwan.

METHODS

Forty-four consecutive patients with IC/BPS for whom conventional treatments failed were prospectively enrolled in this study. Patients were classified as having ulcer (n = 10) or non-ulcer (n = 30) IC/BPS based on their previous cystoscopic findings.

INTERVENTION

All patients received 4 sets of intravesical BoNT-A injections (100 U in 40 suburothelial injections) every 6 months. The primary end-point was the global response assessment (GRA) 6 months after the fourth set of BoNT-A injections. Secondary end-points included the O'Leary-Sant score (OSS) including symptom indexes (ICSI) and problem indexes (ICPI), visual analog scale (VAS) pain score, voiding diary, and urodynamics variables.

RESULTS

After 4 sets of BoNT-A injections, 15 patients with non-ulcer IC/BPS had GRA scores >= 2, while the other 15 had GRA scores < 2. All 10 patients with ulcer IC/BPS had GRA scores < 2 at the study end-point (treatment failure). At baseline, patients with ulcer IC/BPS had significantly higher daytime frequency, nocturia, smaller functional bladder capacity, smaller voided volume, greater VAS, smaller maximal bladder capacity, and greater glomerulation grade than did patients with non-ulcer IC/BPS. After 4 sets of BoNT-A injections, patients with non-ulcer IC/BPS and GRA scores >= 2 or < 2 all had significantly decreased ICSI, ICPI, OSS, VAS pain scores, frequency episodes, and increased functional bladder capacity. However, patients with ulcer IC/BPS showed no significant change in any clinical or urodynamic variable. After failure of repeated BoNT-A injections, all 10 patients with ulcer IC/BPS underwent transurethral electrocauterization of their ulcers, which resulted in immediate pain relief.

LIMITATIONS

Lack of a control arm in this study.

CONCLUSION

Repeated intravesical BoNT-A injections provided effective treatment outcomes at the end-point in half of the patients with non-ulcer IC/BPS, but did not benefit any patient with ulcer type IC/BPS. Ulcer type IC/BPS should be treated as a different disease than non-ulcer IC/BPS. INSTITUTIONAL REVIEW: This study was approved by the Institutional Review Board of the Tzu-chi General Hospital (TCGH 100-06).

Estrogen and progesterone receptors in patients with bladder pain syndrome

OBJECTIVE

Analyze if bladder mucosa of patients with bladder pain syndrome (BPS) have more estrogen receptor (ER) and progesterone receptor (PR) than the normal population.

MATERIAL AND METHOD

Between July 2009 and December 2010, 15 female patients with chronic bladder pain syndrome and 10 female patients without bladder pain were enrolled in the present study. Three pieces of trigonal bladder mucosa were biopsied and sent for estrogen receptor and progesterone receptor immunohistochemistry staining by the Benchmark automated machine. The results were reported as positive and negative and then compared between the two groups.

RESULTS

Estrogen receptor was found in 14 out of 15 patients in the BPS group (93%) and in 7 out of 10 patients in the control group (70%). Progesterone receptor was found in 10 out of 15 patients in the BPS group (66.7%) and 5 out of 10 patients in the control group. Both were not significantly different with p = 0.267 and p = 0.678, respectively.

CONCLUSION

The authors concluded that ER and PR might not play a role in the etiopathogenesis of BPS/IC. However other receptors should be further investigated about their role in this type of pain.

Down-regulation of annexin A1 in the urothelium decreases cell survival after bacterial toxin exposure

PURPOSE

We examined the role of annexins in bladder urothelium. We characterized expression and distribution in normal bladders, biopsies from patients with bladder pain syndrome, cultured human urothelium and urothelial TEU-2 cells.

MATERIALS AND METHODS

Annexin expression in bladder layers was analyzed by quantitative reverse transcriptase-polymerase chain reaction and immunofluorescence. We assessed cell survival after exposure to the pore forming bacterial toxin streptolysin O by microscopy and alamarBlue® assay. Bladder dome biopsies were obtained from 8 asymptomatic controls and 28 patients with symptoms of bladder pain syndrome.

RESULTS

Annexin A1, A2, A5 and A6 were differentially distributed in bladder layers. Annexin A6 was abundant in detrusor smooth muscle and low in urothelium, while annexin A1 was the highest in urothelium. Annexin A2 was localized to the lateral membrane of umbrella cells but excluded from tight junctions. TEU-2 cell differentiation caused up-regulation of annexin A1 and A2 and down-regulation of annexin A6 mRNA. Mature urothelium dedifferentiation during culture caused the opposite effect, decreasing annexin A1 and increasing annexin A6. Annexin A2 influenced TEU-2 cell epithelial permeability. siRNA mediated knockdown of annexin A1 in TEU-2 cells caused significantly decreased cell survival after streptolysin O exposure. Annexin A1 was significantly reduced in biopsies from patients with bladder pain syndrome.

CONCLUSIONS

Several annexins are expressed in human bladder and TEU-2 cells, in which levels are regulated during urothelial differentiation. Annexin A1 down-regulation in patients with bladder pain syndrome might decrease cell survival and contribute to compromised urothelial function.

NAD(P)H:quinone oxidoreductase 1 protects bladder epithelium against painful bladder syndrome in mice

Painful bladder syndrome (PBS), or interstitial cystitis, is a poorly understood chronic disease that is characterized by thinning of the bladder epithelium and intense pain. Here we demonstrate that NAD(P)H:quinone oxidoreductase 1(-/-) (NQO1(-/-)) mice developed in our laboratory represent a new animal model of PBS. NQO1 is known to protect against physiological stress as well as protecting transcription factors against proteasomal degradation. In this study we demonstrate that NQO1 is necessary for bladder epithelium integrity and to prevent the development/progression of PBS. We observed downregulation of energy metabolism, adhesion, and apoptotic signaling cascades, which led to mitochondrial aberrations and profound alterations in energy metabolism, increased susceptibility to reactive oxygen species generation, and apoptosis in luminal epithelium in NQO1(-/-) mice that were absent in wild-type mice. These pathophysiological changes led to the incidence of PBS in NQO1(-/-) mice. Altogether, the results demonstrate for the first time that NQO1 is an endogenous factor in protection against PBS.

The potential of non-adrenergic, non-cholinergic targets in the treatment of interstitial cystitis/painful bladder syndrome

Regulation of bladder function involves both divisions of the autonomic nervous system. However, in addition to the classical autonomic transmitters, noradrenaline and acetylcholine, other autonomic transmitters and other signalling components play important roles in physiology and pathophysiology of the lower urinary tract. Several substances of neuronal non-adrenergic, non-cholinergic (NANC) systems have already proven to considerably influence functional responses in the inflamed urinary bladder. Interstitial cystitis (IC) or painful bladder syndrome (PBS) is a chronic inflammatory bladder disease, characterized by urinary frequency, urgency and pelvic pain. IC/PBS is difficult to diagnose, especially because the etiology of the condition is largely unknown. Despite the unclear nature of the cause and manifestation of IC/PBS, it has been shown that the disease involves a significant NANC component. Here, we review the possible roles of ATP, adenosine, nitric oxide, vasoactive intestinal polypeptide, substance P, and pituitary adenylate cyclase-activating peptide in the contribution to IC/PBS development and manifestation of IC/PBS symptoms.

[Combination of intersticial cystitis and adenomyosis in females suffering from chronic pelvic pain syndrome]

General and endoscopic examinations of 25 patients aged 40-48 years with chronic pelvic pain syndrome (CPPS) revealed combination of two urogenital diseases: interstitial cystitis and adenomyosis of the second-third degree. The complex treatment including a course of lavomax immunocorrection relieved CPPS in 72% (18) patients, reduced the number of recurrences of chronic pelvic diseases in 16% (4) patients. The therapeutic complex proposed may serve an alternative to surgical treatment of adenomyosis of the second-third degree which is uncomplicated with posthemorrhagic iron-deficiency anemia, manifests with pain only and associated with interstitial cystitis.

[Complex local and central therapy of interstitial cystitis with devices AMUS-01-INTRAMAG and AMO-ATOS-E]

A total of 86 females with interstitial cystitis (IC) aged 26-52 years with the disease history over 2.7 years were exposed to intravesical electrostimulation in combination with electromagnetophoresis of heparin-containing mixture of medicines. Relief of pain syndrome and elimination of central hypersensitization were achieved with local procedures on the urinary bladder (UB) alternating (every other day) with procedures of transcranial electrostimulation (TES-therapy, mesodiencephalic modulation). The above treatment proved effective: subjective assessment of pain lowered to "rare" in 60% females, urgency decreased 2-fold, mean effective volume of the bladder increased by 46.2%.

Enhanced urothelial expression of human chorionic gonadotropin beta (hCGβ) in bladder pain syndrome/interstitial cystitis (BPS/IC)

PURPOSE

Bladder pain syndrome/interstitial cystitis (BPS/IC) is associated with urothelial lesions. Pathomechanisms of urothelial damage and factors for urothelial restoration are unknown. hCG is a factor for cellular differentiation, angiogenesis and immune competence of the endometrium during pregnancy. Clinical observations demonstrate improvement of BPS/IC symptoms during pregnancy or during infertility treatment with hCG. Our research aims were to examine the expression of hCG and luteinizing hormone receptor (LHR) in the urothelium of BPS/IC patients and compare the levels of hCGβ with healthy controls.

METHODS

Bladder biopsies of BPS/IC (CLSM: n = 10; qPCR: n = 15); Tumour-free control tissue from cystectomies (n = 12). hCGα, hCGβ and LHR expression were examined by confocal laser scanning microscopy (CLSM), and hCGβ expression was quantified. hCGβ5 and hCGβ7 mRNA splice variants were quantified in real-time polymerase chain reaction.

RESULTS

We found constitutive expression of hCGα, hCGβ and LHR in healthy controls. HCGβ was significantly upregulated in BPS/IC patients in CLSM. PCR analysis revealed higher levels of hCGβ7 than hCGβ5 in controls and BPS/IC patients.

CONCLUSIONS

The constitutive expression of hCG and LHR speaks in favour for a functional signalling in urothelial cells without any association with either pregnancy or tumour. We show for the first time that hCGβ is upregulated in BPS/IC urothelium and that hCGβ7 is the dominant splice variant in those cells. Our findings imply a major role of hCG for urothelial integrity and a disturbance of hCG signalling in case of BPS/IC. We conclude that hCG could gain therapeutical relevance in the future.

[A new experimental model for inducing interstitial cystitis by oxidative stress using bladder instillation of a nitric oxide donor gel]

PURPOSE

The aim of this study is to develop a new experimental model of inducing interstitial cystitis (IC) through vesical instillation of a polymeric solution containing the NO donor S-nitrousglutathione (GSNO) and to compare it to the experimental interstitial cystitis induced by vesical instillation of protamine and potassium chloride.

MATERIAL AND METHOD

For that purpose 40 female Wistar rats were used, divided in four groups: 1. saline solution + GSNO; 2. saline solution + polymeric solution (without GNSO); 3. protamine sulphate + KCl; 4. protamine sulphate + GSNO. The rats received one application (5 animals) or 3 applications (5 animals) of the corresponding substance through intravesical instillation, and after 6 days (5 animals) or 9 days (5 animals) they were euthanized and their bladders were removed for macroscopic evaluation and histological study.

RESULTS

In the macroscopic evaluation we observed edema and hyperemia of the mucosa in 2 (22%) of the animals in group 1, in 0 (0%) of the animals in group 2, in 10 (100%) of the animals in group 3, and in 5 (50%) of the animals in group 4. In the protamine + KCl group and in saline + GSNO similar effects were observed on the bladder wall. The animals in group 2 (saline + polymeric) showed vascular congestion, significantly smaller than the rest after 9 days instillations (p=0.0035). Significant increased fibrosis was observed after instillations in groups 3 and 4, after 6 days (p=0.3781) and 9 days (p=0.0459) respectively, when compared to control (group 2). All groups presented neutrophilic infiltrate of variable intensity 6 days after instillations (p=0.7277). After 9 days, there was a regression of the infiltrate, with no evidence of accentuated neutrophilic reaction in all the groups (p=0.2301).

CONCLUSION

The inflammatory response to bladder instillation of an aqueous solution of S-nitrousglutathione was very similar to that induced by bladder instillation of protamine and KCl. Instillation of an aqueous solution of GSNO can be considered a new model for experimental induction of interstitial cystitis.