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.

TRPV1 and mast cell involvement in repeated variate stress-induced urinary bladder dysfunction in adult female mice.

The etiology of interstitial cystitis/bladder pain syndrome (IC/BPS) is unknown but likely multifactorial. IC/BPS symptoms can be exacerbated by psychological stress, but underlying mechanisms remain to be defined. Transient receptor potential vanilloid 1 (TRPV1) channels, expressed on nerve fibers, have been implicated in bladder dysfunction and colonic hypersensitivity with stress in rodents. Histamine/H1R activation of TRPV1+ nerves increases bladder afferent fiber sensitivity to distension. TRPV1 channels are also expressed on mast cells, previously implicated in contributing to IC/BPS etiology and symptoms. We have examined the contribution of TRPV1 and mast cells to bladder dysfunction after repeated variate stress (RVS). RVS increased (P ≤ 0.05) serum and fecal corticosterone expression and induced anxiety-like behavior in wild-type (WT) mice. Intravesical instillation of the selective TRPV1 antagonist capsazepine (CPZ) rescued RVS-induced bladder dysfunction in WT mice. Trpv1 knockout (KO) mice did not increase voiding frequency with RVS and did not exhibit increased serum corticosterone expression despite exhibiting anxiety-like behavior. Mast cell-deficient mice (B6.Cg-Kitw-sh) failed to demonstrate RVS-induced increased voiding frequency or serum corticosterone expression, whereas control (no stress) mast cell-deficient mice had similar functional bladder capacity to WT mice. TRPV1 protein expression was significantly increased in the rostral lumbar (L1-L2) spinal cord and dorsal root ganglia (DRG) in WT mice exposed to RVS, but no changes were observed in lumbosacral (L6-S1) spinal segments or DRG. These studies demonstrated TRPV1 and mast cell involvement in RVS-induced increased voiding frequency and suggest that TRPV1 and mast cells may be useful targets to mitigate stress-induced urinary bladder dysfunction.NEW & NOTEWORTHY Using pharmacological tools and transgenic mice in a repeated variate stress (RVS) model in female mice, we demonstrate that transient receptor potential vanilloid 1 (TRPV1) and mast cells contribute to the increased voiding frequency observed following RVS. TRPV1 and mast cells should continue to be considered as targets to improve bladder function in stress-induced bladder dysfunction.

EBV infection mediated BDNF expression is associated with bladder inflammation in interstitial cystitis/bladder pain syndrome with Hunner's lesion.

Interstitial cystitis/bladder pain syndrome with Hunner's lesion (HIC) is characterized by chronic inflammation and nerve hyperplasia; however, the pathogenesis of HIC remains a mystery. In this study, we detected both Epstein-Barr virus (EBV) latency infection genes EBNA-1 and LMP-1 and EBV lytic infection BZLF-1 and BRLF-1 expression in the HIC bladders, indicating the coexistence of EBV persistence and reactivation in the B cells in HIC bladders. Upregulation of EBV-associated inflammatory genes in HIC bladders, such as TNF-α and IL-6, suggests EBV infection is implicated in the pathogenesis of bladder inflammation. Nerve hyperplasia and upregulation of brain-derived neurotrophic factor (BDNF) were noted in the HIC bladders. Double immunochemical staining and flow cytometry revealed the origin of BDNF to be EBV-infected B cells. Inducible BDNF expression was noted in B cells upon EBV infection, but not in the T cells. A chromatin immunoprecipitation study revealed BDNF transcription could be promoted by cooperation between EBV nuclear antigens, chromatin modifiers, and B-cell-specific transcription. Knockdown of BDNF in EBV-infected B cells resulted in the inhibition of cell proliferation and viability. Downregulation of phosphorylated SMAD2 and STAT3 after BDNF knockdown may play a role in the mechanism. Implantation of latent EBV-infected B cells into rat bladder walls resulted in a higher expression level of CD45 and PGP9.5, suggesting tissue inflammation and nerve hyperplasia. In contrast, implantation of BDNF depleted EBV-infected B cells abrogated these effects. This is the first study to provide insights into the mechanisms underlying the involvement of EBV-infected B cells in HIC pathogenesis. © 2022 The Pathological Society of Great Britain and Ireland.

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.

The multi-generational familial aggregation of interstitial cystitis, other chronic nociplastic pain disorders, depression, and panic disorder.

BACKGROUND: Interstitial cystitis/painful bladder syndrome (IC) is a chronic pelvic pain condition which has high comorbidity with other nociplastic, or unexplained, pain disorders [e.g. fibromyalgia (FM), irritable bowel syndrome (IBS), and myalgic encephalomyelitis/chronic fatigue (ME/CFS)] and some psychiatric conditions [major depressive disorder (MDD) and panic disorder (PD)]. Here we investigated the shared familiality of IC and these other nociplastic and psychiatric conditions. METHODS: Subjects were identified in the Utah Population Database, which links genealogy data back to the 1800s to medical record diagnosis billing code data back to 1995. We computed the relative risk of each of these disorders among first (FDR), second (SDR), and third-degree relatives (TDR) of six proband groups: IC, FM, IBS, ME/CFS, PD, and MDD. Given the known familial aggregation of each of these disorders, we conducted our analyses to test for heritable interrelationships using proband subgroups whose members did not have the diagnosis assessed in their relatives. RESULTS: We observed strong evidence for heritable interrelationships among all six disorders. Most analyses indicated significantly increased risk for each of the six disorders in FDR, SDR, and TDR of all or most proband groups. Out of 30 possible bidirectional disorder interrelationships, 26 were significant among FDR, 23 were significant among SDR, and 7 were significant among TDR. Clustering was observed in both close and distant relatives. CONCLUSIONS: Our results support a common, heritable component to IC and other nociplastic and psychiatric conditions.

Molecular Profiling of Inflammatory Processes in a Mouse Model of IC/BPS: From the Complete Transcriptome to Major Sex-Related Histological Features of the Urinary Bladder.

Animal models are invaluable in the research of the pathophysiology of interstitial cystitis/bladder pain syndrome (IC/BPS), a chronic aseptic urinary bladder disease of unknown etiology that primarily affects women. Here, a mouse model of IC/BPS was induced with multiple low-dose cyclophosphamide (CYP) applications and thoroughly characterized by RNA sequencing, qPCR, Western blot, and immunolabeling to elucidate key inflammatory processes and sex-dependent differences in the bladder inflammatory response. CYP treatment resulted in the upregulation of inflammatory transcripts such as Ccl8, Eda2r, and Vegfd, which are predominantly involved in innate immunity pathways, recapitulating the crucial findings in the bladder transcriptome of IC/BPS patients. The JAK/STAT signaling pathway was analyzed in detail, and the JAK3/STAT3 interaction was found to be most activated in cells of the bladder urothelium and lamina propria. Sex-based data analysis revealed that cell proliferation was more pronounced in male bladders, while innate immunity and tissue remodeling processes were the most distinctive responses of female bladders to CYP treatment. These processes were also reflected in prominent histological changes in the bladder. The study provides an invaluable reference dataset for preclinical research on IC/BPS and an insight into the sex-specific mechanisms involved in the development of IC/BPS pathology, which may explain the more frequent occurrence of this disease in women.

WGCNA and molecular docking reveal key hub genes and potential natural inhibitor in interstitial cystitis/bladder pain syndrome.

INTRODUCTION AND HYPOTHESIS: The etiology and treatment of interstitial cystitis/bladder pain syndrome are still controversial. The purpose of this study is to determine the key genes and specific regulatory pathways related to it and to find potential drug-active components through integrated bioinformatics. METHODS: The data set GSE11783 was downloaded from GEO database. The modules significantly related to interstitial cystitis/bladder pain syndrome were identified by weighted correlation network analysis. The genes in the key modules were analyzed by functional enrichment and protein interaction by Cytoscape software, and finally the core hub genes were screened. Furthermore, the molecular docking verification of active components and key proteins was carried out by using AutoDock Vin software. RESULTS: Among the 14 modules derived from WGCNA, turquoise module had the highest correlation with IC/BPS (r = 0.85, P < 0.001). The genes in the module were mainly enriched in the biological processes such as the interaction between cytokines and cytokine receptors and chemokine signaling pathway. The genes in the related modules of differentially expressed genes and WGCNA traits were intersected to obtain the core hub genes. Protein-protein interaction network analysis showed that the key genes were upregulated genes CCR7 and CCL19. In terms of molecular docking, triptolide, the active component in the traditional anti-inflammatory drug Tripterygium wilfordii, can form effective molecular binding with both core hub genes. CONCLUSIONS: Our study identified the core hub genes CCR7 and CCL19, which acted as essential components in interstitial cystitis/bladder pain syndrome. Furthermore, CCR7 and CCL19 can form effective binding with triptolide, which will provide new insights into the development of new therapies for interstitial cystitis/bladder pain syndrome.

Functional genomic analyses of IC/BPS patient subgroups: a pilot study.

INTRODUCTION: To further facilitate understanding of disease pathophysiology and patient stratification in interstitial cystitis/bladder pain syndrome (IC/BPS), we utilized molecular phenotyping to compare three clinically distinct IC/BPS patient subgroups. MATERIALS AND METHODS: Total RNA (miRNA and mRNA) was isolated via standard protocols from IC/BPS patient bladder biopsies and assayed on whole genome and microRNA expression arrays. Data from three patient subgroups (n = 4 per group): (1) low bladder capacity (BC; ≤ 400 cc) without Hunner's lesion, (2) low BC with Hunner's lesion, and (3) non-low BC (> 400 cc) were used in comparative analyses to evaluate the influence of BC and HL on gene expression profiles in IC/BPS. RESULTS: The BC comparison (Group 1 v 3) identified 54 miRNAs and 744 mRNAs. Eleven miRNAs mapped to 40 genes. Hierarchical clustering of miRNA revealed two primary clusters: (1) 3/4 low BC patients; (2) 4/4 non-low and 1/4 low BC patients. Clustering of mRNA provided clear separation based on BC. The HL comparison (Group 1 v 2) identified 16 miRNAs and 917 mRNAs. 4 miRNAs mapped to 13 genes. Clustering of miRNA and mRNA revealed clear separation based on HL status. CONCLUSIONS: Significant molecular differences in IC/BPS were found to be associated with the low BC phenotype (e.g., an upregulation of cell proliferation and inflammation marker genes), as well as additional molecular findings that further define the HL+ phenotype (e.g., upregulation of genes involved in bioenergetics reactions) and suggest oxidative stress may play a role.

CircTHBS1 facilitates the progression of interstitial cystitis depending on the regulation of miR-139-5p/MFN2 axis.

Circular RNA (circRNA) have been found to play an important role in the progression of many diseases, including interstitial cystitis (IC). However, the role of circTHBS1 in IC progression is still unclear. Exploring the role and potential molecular mechanism of circTHBS1 in the development of IC. The enzyme-linked immunosorbent assay was used to assess the levels of inflammatory cytokines. The expression levels of circTHBS1, microRNA (miR)-139-5p, and mitofusin 2 (MFN2) were evaluated using quantitative real-time PCR. Cell proliferation and migration were determined using MTT assay, Edu staining, and transwell assay. The protein levels of epithelial-mesenchymal transition (EMT) markers and MFN2 were examined using western blot analysis. The relationship between miR-139-5p and circTHBS1 or MFN2 was confirmed using the dual-luciferase reporter assay and RIP assay. CircTHBS1 was highly repressed in IC tissues and cells, and its expression was positively correlated with the inflammatory response of IC patients. CircTHBS1 could promote the proliferation, migration, EMT process, and inflammation of IC cells, while its knockdown had an opposite effect. CircTHBS1 could serve as a sponge of miR-139-5p, and miR-139-5p could participate in the regulation of circTHBS1 on IC cell progression. In addition, miR-139-5p could target MFN2, and it could inhibit the progression of IC cells by targeting MFN2. Furthermore, circTHBS1 sponged miR-139-5p to positively regulate MFN2. CircTHBS1 promoted IC cell proliferation, migration, EMT process, and inflammation by regulating the miR-139-5p/MFN2 axis indicating that circTHBS1 might be a potential target for IC treatment.

Identification of key genes in human urothelial cells corresponding to interstitial cystitis/bladder pain syndrome in a lipopolysaccharide-induced cystitis model.

AIMS: The cellular functions of bladder urothelial cells in interstitial cystitis/bladder pain syndrome (IC/BPS) have not been well revealed and understood. Thus, the study aims to identify key genes and significant pathways in urothelium corresponding to IC/BPS in a lipopolysaccharide (LPS)-induced cystitis model and provide novel clues related to diagnosis and treatment of IC/BPS. METHODS: Human urothelial cells (HUCs) were incubated with LPS (50 µg/ml for 24 h). Microarray was applied to analyze the differentially expressed genes (DEGs) between HUCs under LPS treatment and the control group. DEGs in the two groups were identified and then used for enrichment analysis. Subsequently, protein-protein interaction (PPI) network based on DEGs was constructed. Lastly, the top five key genes were identified through the Cytoscape (version 3.7.2) using the "Clustering Coefficient" algorithm. RESULTS: One hundred and seventy-one DEGs (96 upregulated genes and 75 downregulated genes) were identified between the LPS treatment and control group. The established PPI network was composed of 169 nodes and 678 edges. Moreover, C19orf33, TRIM31, MUC21, ELF3, and IFI27 were identified as hub genes in the PPI network. Subsequently, a statistically increased expression level of TRIM31 and ELF3 was validated by real-time quantitative-polymerase chain reaction and immunohistochemistry in bladder tissues from 20 patients with IC/BPS. CONCLUSIONS: TRIM31 and ELF3 may be the two hub genes in urothelium corresponding to IC/BPS. More studies are warranted to further validate the findings. The identified marker genes may be useful targets for further studies to develop diagnostic tools and more effective therapies for a broader group of women with IC/PBS.

Hydrodistention does not alter bladder gene expression profiles in patients with non-Hunner lesion interstitial cystitis/bladder pain syndrome.

AIMS: Gene expression profiling of bladder biopsies in patients with interstitial cystitis/bladder pain syndrome (IC/BPS), typically obtained following therapeutic bladder hydrodistention (HOD), is used to improve our understanding of molecular phenotypes. The objective of this study was to determine if the HOD procedure itself impacts the biopsy gene expression profile and, by extension, whether biopsies from non-HOD bladders are appropriate controls. METHODS: Bladder biopsies were obtained just before HOD and immediately following HOD from 10 consecutively recruited IC/BPS patients undergoing therapeutic HOD. Biopsies were also obtained from four non-IC/BPS patients who did not undergo HOD (controls). Total RNA was isolated from each of the 24 samples and used to query whole-genome microarrays. Differential gene expression analysis was performed to compare expression profiles of IC/BPS biopsies before and after HOD, and between IC/BPS and control biopsies. RESULTS: Principal component analysis revealed complete separation between gene expression profiles from IC/BPS and control samples (q ≤ 0.05) and while IC/BPS samples before and after HOD showed no significant differences in expressed genes, 68 transcripts were found to be significantly different between IC/BPS and control samples (q ≤ 0.05). CONCLUSIONS: The bladder HOD procedure itself does not significantly change gene expression within the IC/BPS patient bladder, a finding that provides evidence to support the use of biopsies from non-IC/BPS patients that have not undergone HOD as controls for gene expression studies.

Integrated mRNA-miRNA transcriptome analysis of bladder biopsies from patients with bladder pain syndrome identifies signaling alterations contributing to the disease pathogenesis.

BACKGROUND: Interstitial cystitis, or bladder pain syndrome (IC/BPS), is a chronic bladder disorder characterized by lower abdominal pain associated with the urinary bladder and accompanied by urinary frequency and urgency in the absence of identifiable causes. IC/PBS can be separated into the classic Hunner's ulcerative type and the more prevalent non-ulcerative disease. Our aim was to unravel the biological processes and dysregulated cell signaling pathways leading to the bladder remodeling in non-ulcerative bladder pain syndrome (BPS) by studying the gene expression changes in the patients' biopsies. METHODS: We performed paired microRNA (miRNA) and mRNA expression profiling in the bladder biopsies of BPS patients with non-Hunner interstitial cystitis phenotype, using comprehensive Next-generation sequencing (NGS) and studied the activated pathways and altered biological processes based on the global gene expression changes. Paired mRNA-miRNA transcriptome analysis delineated the regulatory role of the dysregulated miRNAs by identifying their targets in the disease-induced pathways. RESULTS: EIF2 Signaling and Regulation of eIF4 and p70S6K Signaling, activated in response to cellular stress, were among the most significantly regulated processes during BPS. Leukotriene Biosynthesis nociceptive pathway, important in inflammatory diseases and neuropathic pain, was also significantly activated. The biological processes identified using Gene Ontology over-representation analysis were clustered into six main functional groups: cell cycle regulation, chemotaxis of immune cells, muscle development, muscle contraction, remodeling of extracellular matrix and peripheral nervous system organization and development. Compared to the Hunner's ulcerative type IC, activation of the immune pathways was modest in non-ulcerative BPS, limited to neutrophil chemotaxis and IFN-γ-mediated signaling. We identified 62 miRNAs, regulated and abundant in BPS and show that they target the mRNAs implicated in eIF2 signalling pathway. CONCLUSIONS: The bladders of non-ulcerative BPS patients recruited in this study had alterations consistent with a strong cell proliferative response and an up-regulation of smooth muscle contractility, while the contribution of inflammatory processes was modest. Pathway analysis of the integrated mRNA-miRNA NGS dataset pinpointed important regulatory miRNAs whose dysregulation might contribute to the pathogenesis. Observed molecular changes in the peripheral nervous system organization and development indicate the potential role of local bladder innervation in the pain perceived in this type of BPS.

Exploration of the core genes in ulcerative interstitial cystitis/bladder pain syndrome.

OBJECTIVE: Interstitial cystitis (IC)/bladder pain syndrome (BPS) is a chronic inflammatory disease that can cause bladder pain and accompanying symptoms, such as long-term urinary frequency and urgency. IC/BPS can be ulcerative or non-ulcerative. The aim of this study was to explore the core genes involved in the pathogenesis of ulcerative IC, and thus the potential biomarkers for clinical treatment. MATERIALS AND METHODS: First, the gene expression dataset GSE11783 was downloaded using the Gene Expression Omnibus (GEO) database and analyzed using the limma package in R to identify differentially expressed genes (DEGs). Then, the Database for Annotation, Visualization and Integrated Discovery (DAVID) was used for Gene Ontology (GO) functional analysis, and the Kyoto Encyclopedia of Genes and Genomes (KEGG) was used for pathway enrichment analysis. Finally, the protein-protein interaction (PPI) network was constructed, and key modules and hub genes were determined using the STRING and Cytoscape software. The resulting key modules were then analyzed for tissue-specific gene expression using BioGPS. RESULTS: A total of 216 up-regulated DEGs and 267 down-regulated genes were identified, and three key modules and nine hub genes were obtained. CONCLUSION: The core genes (CXCL8, CXCL1, IL6) obtained in this study may be potential biomarkers of interstitial cystitis with guiding significance for clinical treatment.

HMGB1 and its membrane receptors as therapeutic targets in an intravesical substance P-induced bladder pain syndrome mouse model.

HMGB1, a nuclear protein, once released to the extracellular space, promotes somatic and visceral pain signals. We thus analyzed the role of HMGB1 in an intravesical substance P-induced bladder pain syndrome (BPS) mouse model. Intravesical administration of substance P caused referred hyperalgesia/allodynia in the lower abdomen and hindpaw without producing severe urothelial damage, which was prevented by an anti-HMGB1-neutralizing antibody, thrombomodulin α capable of inactivating HMGB1 and antagonists of RAGE or CXCR4. The HMGB1 inactivation or RAGE blockade also reversed the established bladder pain symptoms. HMGB1 and RAGE are thus considered to serve as therapeutic targets for BPS.

Bioinformatics analysis of the Hub genes and key pathways of interstitial cystitis pathogenesis.

AIMS: This study aimed to identify suitable datasets for reanalysis and then explore potential key genes and related pathways of interstitial cystitis (IC). METHODS: We searched the Gene Expression Omnibus database and three expression profile datasets and included 23 lesions of IC and 9 normal tissues in the analysis. Eight urine specimens of patients with IC and five urine specimens of healthy controls were also included. Then, these datasets were reanalyzed to determine the differentially expressed genes (DEGs), which were used to perform Gene Ontology and pathway enrichment analyses. These identified candidate genes were also applied to generate a protein-protein interaction (PPI) network. RESULTS: Forty-two common DEGs were sorted and identified from two datasets, both of which included the samples of bladder lesions. Based on their functions and signaling pathways, these 42 DEGs are mainly classified as cell-surface proteins and are involved in the immune and inflammatory responses. The PPI network included 41 nodes. In this network, we identified 11 genes as central nodes that are involved in the immune system and the inflammatory response. Furthermore, IC with Hunner's lesions shared the same DEGs with IC without Hunner's lesions. In both subgroups (IC with and without Hunner's lesions), we identified some common DEGs shared between bladder lesions and urine samples. CONCLUSION: Using bioinformatics, we integrated different IC-related datasets and identified potential critical genes involved in IC that may contribute to future research on IC.

Non-bladder centric interstitial cystitis/bladder pain syndrome phenotype is significantly associated with co-occurring endometriosis.

INTRODUCTION: Interstitial cystitis/bladder pain syndrome (IC/BPS) and endometriosis are coexistent diagnoses in 48%-65% of women with chronic pelvic pain (CPP), suggesting that dual screening may be warranted. To further investigate the clinical relationship and risk factors between these two conditions, we performed a retrospective review of our large IC/BPS patient data registry. MATERIALS AND METHODS: We evaluated IC/BPS patients who were prospectively enrolled into our registry who completed validated questionnaires and underwent therapeutic hydrodistension, during which anesthetic bladder capacity (BC) and Hunner's lesion (HL) status were recorded. Demographic/medical history were reviewed. IC/BPS patients with co-occurring endometriosis diagnosis versus those without were compared using descriptive statistics as well as multivariate regression analyses to determine predictors of co-occurring disease. RESULTS: Of 431 IC/BPS participants, 82 (19%) were also diagnosed with endometriosis. These women were significantly younger, had increased prevalence of non-low BC (> 400 cc), and decreased prevalence of HL (p < 0.05). Patients with co-occurring endometriosis also had increased prevalence of irritable bowel syndrome (IBS), CPP, fibromyalgia, and vulvodynia (p < 0.05). On multivariate analysis, non-low BC (OR 4.53, CI 1.004-20.42, p = 0.049), CPP (OR 1.84, CI 1.04-3.24, p = 0.04), and fibromyalgia (OR 1.80, CI 1.03-3.14, p < 0.04) were significantly associated with a diagnosis of endometriosis. CONCLUSIONS: Patients with IC/BPS and co-occurring endometriosis were significantly more likely to carry a non-bladder centric IC/BPS phenotype as well as several comorbid, systemic pain diagnoses. This study characterizes features of a target IC/BPS phenotype that could potentially benefit from endometriosis and systemic pain syndrome screening.

Molecular pathogenesis of interstitial cystitis/bladder pain syndrome based on gene expression.

Interstitial cystitis/painful bladder syndrome (IC/PBS) is a chronic bladder inflammation that leads to chronic bladder pain and urinary urgency and frequency. The presentation of IC/PBS is heterogeneous, and it is classified as ulcerative IC/PBS and nonulcerative IC/PBS. The main cause of IC/PBS is thought to be a persistent inflammatory condition in the bladder, though the actual pathophysiology has not been identified yet. Although the underlying pathophysiology of IC/PBS is not completely understood, several theories for the etiology of this syndrome have been suggested, including deficiency of the glycosaminoglycan covering urothelium surface that results in leaky urothelium infection, immunological etiology, activated mast cells, neural changes, and inflammation. In addition, there are no gold standards for the detection of this disorder to date. So, determination of gene expression and its role in different signaling pathways in the pathogenesis of this heterogeneous disorder contribute to the more efficient cognition of the pathophysiology of this disease and to the design of effective treatments and molecular diagnostic methods for IC/PBS.

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

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

Molecular Taxonomy of Interstitial Cystitis/Bladder Pain Syndrome Based on Whole Transcriptome Profiling by Next-Generation RNA Sequencing of Bladder Mucosal Biopsies.

PURPOSE: We systematically characterized gene expression, inflammation and neovascularization in patients with interstitial cystitis/bladder pain syndrome to obtain biological evidence supporting diagnosis and classification. MATERIALS AND METHODS: We sequenced RNA obtained from bladder mucosal biopsies of 33 patients with 3 subtypes of interstitial cystitis/bladder pain syndrome, including Hunner lesions in 12, no Hunner lesions in 11 but with glomerulations and neither Hunner lesions nor glomerulations in 10, and 9 controls. Differentially expressed genes of each subtype were searched to identify subtype specific biological pathways and candidate genes important for pathogenesis. Candidate genes were validated by quantitative polymerase chain reaction and immunohistochemistry. Digital immunohistochemical quantification was performed to assess subepithelial lymphoplasmacytic cell and microvessel density. Relationships between candidate gene over expression and symptom severity were explored. RESULTS: Patients with Hunner lesions showed a distinct gene expression profile associated with significant up-regulation of biological processes involving immune responses and infection, and an increase in subepithelial lymphoplasmacytic cell and microvessel density. Over expression of 2 candidate genes, VEGF and BAFF, correlated with symptom severity. Meanwhile, the gene expression profiles of patients with the 2 subtypes without Hunner lesions were similar to those of controls. No difference in biological pathways or subepithelial lymphoplasmacytic cell and microvessel density were detected between these 2 subtypes and controls. CONCLUSIONS: Interstitial cystitis/bladder pain syndrome with Hunner lesions shows distinct genomic and histological features associated with immune responses and infection. In addition, VEGF and BAFF are potential disease biomarkers and therapeutic targets. This subtype should be considered separate from the syndrome.

Analysis of key genes and micro-RNA-mRNA regulatory networks in women with ulcerative interstitial cystitis/pain bladder syndrome.

INTRODUCTION AND HYPOTHESIS: This aim of this study was to better understand ulcerative interstitial cystitis/painful bladder syndrome (IC/PBS) at the molecular level and provide new clues related to diagnosis and treatment. METHODS: The microarray data set GSE11783, including the mRNA and miRNA profiles of bladder tissue obtained at cystoscopic biopsy from patients with ulcerative IC/PBS (presence of at least one Hunner's ulcer) and normal controls, was downloaded from the GEO (Gene Expression Omnibus) database (National Center for Biotechnology Information). These were evaluated using Greenspring GX and Ingenuity Pathway Analysis (IPA) software. The differentially expressed genes (DEGs) and miRNAs (DEMs) in these two groups were identified. Subsequently, the DEGs were subjected to functional analysis, and a protein-protein interaction (PPI) network was constructed. Finally, the miRNA-mRNA regulatory network was visualized using Cystoscope software. RESULTS: Four DEMs and 1521 DEGs were identified between the ulcerative IC/PBS and control groups. The PPI network of the DEGs was constructed by STRING, which was composed of 393 nodes and 1039 edges, including 221 upregulated genes and 172 downregulated genes. Moreover, 27 genes in the PPI network were identified as hub genes in the IC/PBS group, e.g., PNOC, SSTR1, FPR3, GPR18 and APLNR. Subsequently, 27 clusters were selected from the PPI network using MCODE. It was shown that the most significant cluster consisted of 22 nodes and 231 edges. Moreover, miR-21 was the most significantly upregulated miRNA and was predicted to target one upregulated gene (RASGRP1) and two downregulated genes (KLF5 and SC5D). CONCLUSIONS: The results of this data mining and integration provide further information on the possible molecular basis of IC/PBS pathogenesis as well as potential biomarkers and therapeutic targets for ulcerative IC/PBS diagnosis and treatment.