Immune cell profiles of patients with interstitial cystitis/bladder pain syndrome

Characteristic genes and immune landscape of interstitial cystitis

BACKGROUND

Interstitial cystitis (IC) was still a disease with the exclusive diagnosis and lacked an effective gold standard. It was of great significance to find diagnostic markers for IC. Our study was aimed to screen characteristic genes via machine learning algorithms, characterize the immune landscape of IC, and show correlations between characteristic genes and immune cell subtypes.

METHODS

RNA sequencing data sets on IC were downloaded from Gene Expression Omnibus (GEO) database, including GSE57560, GSE11783 and GSE621, whose corresponding platforms were GPL16699, GPL570 and GPL262 respectively. Three machine learning algorithms were applied for identification of characteristic gene for IC. Single sample Gene Set Enrichment Analysis (ssGSEA) was applied to figure out the immune cell infiltration (ICI) of IC and normal tissue samples. Correlation analysis was performed via Spearman test. Receiver operator characteristic curve (ROC) was used to evaluate diagnostic efficacy of key genes.

RESULTS

CCL18, MMP10 and WIF1 were identified as characteristic gene via machine learning algorithms. MMP10 and CCL18 were with higher expression in IC tissues compared with normal bladder tissues, while WIF1 had lower expressionin IC tissues (P < 0.05). These three genes had good diagnostic efficacy for IC. Compared with normal bladder tissues, 18 immune cell subtypes were up-regulated in interstitial cystitis tissues (P < 0.05). MMP10 and CCL18 were positively correlated to immune scores in IC, while WIF1 was negatively correlated to immune scores (P > 0.05).

CONCLUSION

We screened the feature genes, CCL18, MMP10 and WIF1, among the differentially expressed genes (DEGs) by three different machine learning algorithms. They showed good diagnostic performance in both training and testing cohorts and were potential diagnostic markers for IC. We paint the immune landscape of IC. In IC tissue, immune cell subtypes infiltrated extensively. Most immune cell subtypes were up-regulated in IC tissue, including mast cells, activated CD4 T cells, and regulatory T cells that suppress immune responses. MMP10 and CCL18 had positive correlation to ICI, while WIF was negatively correlated with ICI. MMP10 and CCL18 may be the driving factors of immune response or their expression levels may be increased by immune response. The effect of characteristic genes of IC on immune cell subtypes still needed to be further explored.

The integration of biomarkers and patient-reported outcomes improves prediction of interstitial cystitis syndrome

INTRODUCTION

Interstitial Cystitis/Bladder Pain Syndrome (IC/BPS) is a chronic condition characterized by debilitating bladder pain and urinary symptoms, such as urgency and frequency. Its considerable impact on patients' quality of life is compounded by the diagnostic challenges stemming from symptom overlap with other urological disorders and insufficient standardization of diagnostic criteria.

AREAS COVERED

This review examines various key aspects of IC/BPS, including the identification of biomarkers such as interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), monocyte chemotactic protein-1 (MCP-1) and vascular endothelial growth factor (VEGF) that correlate with symptom severity and underlying inflammatory processes. It discusses the importance of urinary and serum biomarkers, current challenges in clinical assessments, the variability in biomarker collection and analysis methods, and emphasizes the role of patient-reported outcomes (PROs) such as the O'Leary - Sant (ICSI/ICPI) questionnaires and the Visual Analogue Scale in capturing the patient's subjective experience and quality of life.

EXPERT OPINION

Strengthening the integration of biomarkers with PROs is crucial for enhancing diagnostic accuracy and personalizing treatment approaches for IC/BPS patients. The review calls for future research to develop standardized protocols, which will improve patient care by facilitating a more tailored management strategy based on a comprehensive understanding of IC/BPS.

Suoquan Wan mitigates bladder overactivity via modulation of neuroimmune homeostasis in perimenopausal rats

BACKGROUND

Overactive bladder (OAB) is a common disorder in perimenopausal women, involving detrusor regulation by bladder neuro-immune interactions. While Suoquan Wan (SQW) has shown efficacy in alleviating OAB symptoms, its underlying mechanisms remain unclear.

PURPOSE

The aim of this study was to investigate the therapeutic effects of SQW on perimenopausal overactive bladder (OAB) and elucidate its underlying mechanisms in restoring bladder neuro-immune homeostasis.

METHODS

Initially, vaginal smears were performed to identify perimenopausal rats. The effects of SQW on the structure and function of the perimenopausal bladder were assessed using urodynamic studies, organ bath assays, and histological analyses, including hematoxylin and eosin (HE) and Masson staining. Subsequently, single-nucleus RNA sequencing (snRNA-seq) was conducted to investigate the mechanisms by which SQW modulates neuron-macrophage interactions. To validate the sequencing data, PCR and immunofluorescence (IF) assays were utilized to evaluate neural homeostasis. Further analyses involved IF, flow cytometry, and fluorescence bead assays to determine the function and proportion of bladder macrophages. The co-localization of neurons and macrophages was visualized using IF. Finally, transwell co-culture experiments were carried out to explore the regulatory effects of SQW on bladder neuro-immune homeostasis.

RESULTS

SQW significantly attenuates the frequency of non-micturition contractions and reduces residual urine volume, alleviates detrusor hyperactivity in OAB rats in response to external stimuli such as EFS, CCh, and KCl, and markedly improves urinary efficiency in perimenopausal OAB rats. SnRNA-seq data indicate that SQW modulates bladder neuro-immune homeostasis in these rats. Furthermore, SQW obviously decreases the proportion of ChAT-positive nerve fibers while enhancing the abundance of nNOS and MAP-positive nerve fibers in the bladder. SQW also reduces the proportion of CD45+ CD11b/C+MHCⅡ+ macrophages in the bladder muscle layer. Transwell co-culture assays reveal that the effects of SQW on MAP-2 and ChAT are mediated through the neuron-macrophage interaction mechanism.

CONCLUSIONS

SQW alleviated perimenopausal OAB by specifically modulating the neuron-macrophage interaction and enhancing bladder neuro-immune homeostasis.

Telitacicept for refractory cystitis associated with severe systemic lupus erythematosus: A case report

BACKGROUND

Lupus cystitis, a severe complication of systemic lupus erythematosus (SLE), presents considerable treatment challenges.

PURPOSE

This case report describes the use of telitacicept in treating severe SLE with lupus cystitis.

RESEARCH DESIGN

A single patient with lupus cystitis.

STUDY SAMPLE

A patient with symptoms including frequent urination, urgency, and acute urinary retention.

DATA COLLECTION AND ANALYSIS

Initial treatments included corticosteroid pulse therapy, immunoglobulin, and cyclophosphamide, which improved laboratory indicators but failed to alleviate symptoms of urinary retention. The patient was then treated with telitacicept.

RESULTS

Significant alleviation of urinary retention was observed shortly after incorporating telitacicept into the treatment regimen. The patient's condition remained stable with no relapse during the subsequent 10 months of follow-up.

CONCLUSIONS

This case highlights the therapeutic potential of telitacicept for SLE patients who are unresponsive to conventional therapies, particularly those with severe manifestations such as lupus cystitis.

Sex-specific transcriptome similarity networks elucidate comorbidity relationships

Humans present sex-driven biological differences. Consequently, the prevalence of analyzing specific diseases and comorbidities differs between the sexes, directly impacting patients' management and treatment. Despite its relevance and the growing evidence of said differences across numerous diseases (with 4,370 PubMed results published within the past year), knowledge at the comorbidity level remains limited. In fact, to date, no study has attempted to identify the biological processes altered differently in women and men, promoting differences in comorbidities. To shed light on this problem, we analyze expression data for more than 100 diseases from public repositories, analyzing each sex independently. We calculate similarities between differential expression profiles by disease pairs and find that 13-16% of transcriptomically similar disease pairs are sex-specific. By comparing these results with epidemiological evidence, we recapitulate 53-60% of known comorbidities distinctly described for men and women, finding sex-specific transcriptomic similarities between sex-specific comorbid diseases. The analysis of shared underlying pathways shows that diseases can co-occur in men and women by altering alternative biological processes. Finally, we identify different drugs differentially associated with comorbid diseases depending on patients' sex, highlighting the need to consider this relevant variable in the administration of drugs due to their possible influence on comorbidities.

Identification and validation of immune and diagnostic biomarkers for interstitial cystitis/painful bladder syndrome by integrating bioinformatics and machine-learning

Background

The etiology of interstitial cystitis/painful bladder syndrome (IC/BPS) remains elusive, presenting significant challenges in both diagnosis and treatment. To address these challenges, we employed a comprehensive approach aimed at identifying diagnostic biomarkers that could facilitate the assessment of immune status in individuals with IC/BPS.

Methods

Transcriptome data from IC/BPS patients were sourced from the Gene Expression Omnibus (GEO) database. We identified differentially expressed genes (DEGs) crucial for gene set enrichment analysis. Key genes within the module were revealed using weighted gene co-expression network analysis (WGCNA). Hub genes in IC/BPS patients were identified through the application of three distinct machine-learning algorithms. Additionally, the inflammatory status and immune landscape of IC/BPS patients were evaluated using the ssGSEA algorithm. The expression and biological functions of key genes in IC/BPS were further validated through in vitro experiments.

Results

A total of 87 DEGs were identified, comprising 43 up-regulated and 44 down-regulated genes. The integration of predictions from the three machine-learning algorithms highlighted three pivotal genes: PLAC8 (AUC: 0.887), S100A8 (AUC: 0.818), and PPBP (AUC: 0.871). Analysis of IC/BPS tissue samples confirmed elevated PLAC8 expression and the presence of immune cell markers in the validation cohorts. Moreover, PLAC8 overexpression was found to promote the proliferation of urothelial cells without affecting their migratory ability by inhibiting the Akt/mTOR/PI3K signaling pathway.

Conclusions

Our study identifies potential diagnostic candidate genes and reveals the complex immune landscape associated with IC/BPS. Among them, PLAC8 is a promising diagnostic biomarker that modulates the immune response in patients with IC/BPS, which provides new insights into the future diagnosis of IC/BPS.

Exploring the therapeutic potential of PACAP in Hunner-type Interstitial Cystitis

PURPOSE

This study aims to elucidate the role of pituitary adenylate cyclase-activating polypeptide (PACAP) in Hunner-type Interstitial Cystitis (HIC) and evaluate its potential as a therapeutic target.

METHODS

Bladder tissue samples were obtained from HIC patients and normal bladder tissue from bladder cancer patients. PACAP expression was assessed through immunohistochemistry. An in vitro HIC model was established using LPS-induced SV-HUC1 cells. PACAP knockdown was performed using siRNA. The expression of inflammatory markers (IL-6, IL-1β, TNF-α) and fibrotic markers (fibronectin 1, TGF-β1, collagen I) was evaluated via qPCR, Western blot, and ELISA. Cell migration and proliferation were analyzed using wound healing and CCK-8 assays. Transcriptomic profiling was conducted to identify differentially expressed genes (DEGs) and explore their functional significance.

RESULTS

PACAP expression was significantly elevated in the bladder tissues of HIC patients. LPS stimulation of SV-HUC1 cells induced PACAP expression alongside increased levels of inflammatory cytokines, validating the inflammatory model. PACAP knockdown markedly suppressed IL-6, IL-1β, and TNF-α expression and attenuated LPS-induced fibrosis by reducing fibronectin 1, TGF-β1, and collagen I levels. Additionally, PACAP knockdown inhibited LPS-induced cell migration and proliferation, as evidenced by wound healing and CCK-8 assays. Transcriptomic analysis revealed distinct molecular alterations in HIC tissues, including PACAP upregulation, implicating it in HIC pathogenesis.

CONCLUSION

PACAP plays a pivotal role in the inflammatory and fibrotic pathways of HIC. PACAP knockdown alleviates LPS-induced pathological responses, highlighting its potential as a novel therapeutic target. Further research is warranted to investigate PACAP's precise mechanisms in HIC and its translational application in clinical settings.

Matched serum- and urine-derived biomarkers of interstitial cystitis/bladder pain syndrome

Setting up the correct diagnosis of interstitial cystitis/bladder pain syndrome (IC/BPS), a chronic inflammatory disease of the bladder, is a challenge, as there are neither diagnostic criteria nor reliable and non-invasive disease biomarkers available. The aim of the present study was to simultaneously determine matched serum- and urine-derived biomarkers of IC/BPS, which would provide additional insights into disease mechanisms and set the basis for further biomarker validation. Our study included 12 female patients with IC/BPS and 12 healthy controls. A total of 33 different biomarkers were measured, including cytokines and chemokines, proteins involved in extracellular matrix remodeling, adhesion molecules, growth factors, and markers of oxidative stress using enzyme linked immunoassays and multiplex technology. Heatmaps and principal component analysis based on significantly altered biomarkers, revealed urine- and serum-associated IC/BPS signatures that clearly differentiated IC/BPS patients from controls. Four biomarkers, including CCL11, BAFF, HGF and MMP9, were significantly upregulated in both serum and urine of patients with IC/BPS compared to controls. Serum levels of MMP9 were associated with disease severity and could distinguish well between IC/BPS patients with and without Hunner's lesions. Systemic levels of MMP9 can therefore mirror the local pathology within the bladders of IC/BPS patients, and MMP9 may prove to be a useful target for the development of novel therapeutic interventions. Utilizing a comprehensive panel of both urine and serum biomarkers, identified here, holds promise for disease detection in IC/BPS patients.

Lactoferrin in the treatment of interstitial cystitis: a retrospective pilot study

Interstitial cystitis (IC), defined as a painful bladder syndrome (PBS), is a chronic condition that manifests itself as a suprapubic pain associated with an enhancing of frequency/urgency of urination, and for which there is no cure. Here, we present a retrospective pilot study on women affected from IC/PBS and treated with bovine lactoferrin (bLf). A total of 31 women, affected (20) or unaffected (11) from hereditary thrombophilia (HT), presented the median of 6 episodes of IC/PBS during the 6 months before the study. Treatment consisted of 17 weeks of orally administered Valpalf® capsules, containing bLf plus sodium bicarbonate and citrate. Out of 31 patients, only 3 women had one episode of IC/PBS during the follow-up period, while no episode was observed in 28 women. In the HT group, a significant decrease in both serum IL-6 and D-dimers was found after Valpalf® treatment. Moreover, in Valpalf®-treated women, cystoscopy revealed a global improvement in the appearance of the bladder, especially in term of inflammation/irritation and presence of Hunner ulcers. Even if our results must be corroborated by randomized double-blinded controlled trials on a larger number of patients, our observations indicate that bLf treatment is efficient in relieving IC/PBS symptoms, without side effects.

Purine nucleoside phosphorylase as a target for the treatment of interstitial cystitis/bladder pain syndrome with and without Hunner lesions

Chronic visceral pain disorders, such as interstitial cystitis/bladder pain syndrome (IC/BPS), are difficult to treat, and therapies are limited in number and efficacy. Emerging evidence suggests that alterations in the enzyme purine nucleoside phosphorylase (PNPase) may participate in oxidative injury and cellular damage. PNPase is important for the metabolism of 'tissue-protective' purine metabolites to 'tissue-damaging' purines that generate free radicals. The aim of this study is to test whether patients living with IC/BPS without or with Hunner lesions and irrespective of any therapies exhibit purine dysregulation with higher levels of tissue-damaging purine metabolites as measured by liquid chromatography-tandem mass spectrometry. Our results demonstrate that levels of urotoxic purine metabolites (hypoxanthine and xanthine) in IC/BPS patients with and without Hunner lesions are elevated compared to healthy controls. These findings suggest there may be pathophysiologic commonalities between patient subtypes. Furthermore, the accumulation of uroprotective purines and depletion of urodamaging purines by PNPase inhibition may be therapeutically effective in both groups of patients.

Cytokines in Bladder Pain Syndrome: A Review of the Literature

INTRODUCTION AND HYPOTHESIS

Bladder pain syndrome (BPS) is poorly understood with both the aetiology and pathophysiology being unknown. Symptoms overlap with other disorders, such as overactive bladder (OAB) and chronic pelvic pain disorders such as endometriosis, making a consensus on how to diagnosis and manage patients challenging. The development of biomarkers for BPS may be the key to understanding more about its pathophysiology, as well as aiding diagnosis, subclassification, and discovering new drug targets for its management. As inflammation is widely understood to hold a central role in BPS, the evaluation of cytokines has gained interest. This article summarises the current literature and understanding of urinary, serum, and bladder tissue cytokines found elevated in patients with bladder pain syndrome.

METHODS

literature search using Pub Med with the keywords "bladder pain syndrome", "painful bladder syndrome", "bladder pain", "Interstitial cystitis" AND "cytokines" or "inflammation". This study was except from institutional approval.

RESULTS

Thirty-six cytokines have been identified as being statistically significantly elevated in either the serum, urine, or bladder tissue of patients with bladder pain syndrome in the 22 studies identified in this review of the literature. These cytokines include those from the interleukin group (n = 14), the CXC chemokine group (n = 5), and the C-C chemokine group (n = 7).

CONCLUSIONS

CXCL-1, CXCL-8, CXCL-9, CXCL-10, CXCL-11 from the CXC chemokine group, and CCL2, CCL4, CCL5, CCL7, and CCL11 from the C-C chemokine group have been found to be significantly elevated in patients with bladder pain in the literature. Many of these analytes also have supporting evidence for their roles in bladder pain from animal models and studies in other chronic inflammatory conditions. It is likely that a single cytokine will not serve as an adequate biomarker of disease in bladder pain syndrome for either diagnosis or disease severity. Instead, panels of inflammatory mediators may reveal more about the different pathways of inflammation leading to similar presentations of bladder pain in patients.

Interstitial cystitis-an imbalance of risk and protective factors?

Interstitial cystitis (IC) presents as a chronic pain condition with variable combinations of symptoms depending on the species and individual patient. It is diagnosed by the presence of lower urinary tract signs and symptoms in combination with a variety of comorbid health problems, a history of life adversities, and the absence of other conditions that could cause the lower urinary tract signs. IC occurs naturally in humans and cats as a dimensional condition, with patients presenting with mild, moderate, and severe symptoms. Most patients appear to recover without specific treatment. A number of rodent models of IC have been used to study its causes and treatments. Unfortunately, current therapies generally fail to ameliorate IC symptoms long-term. The recent classification of IC as a chronic primary pain disorder calls for a rethinking of current clinical and research approaches to it. Beginning when a patient encounters a clinician, precipitating, perpetuating, and palliating risk factors can be addressed until a cause or reliably effective therapy is identified, and identifying predisposing and preventive factors can inform epidemiological studies and health promotion interventions. Predisposing, precipitating, and perpetuating risk factors, including environmental, psychological, and biological, increase the activity of the central threat response system (CTRS), which plays a clinically important role in IC symptoms. Studies in cats and rodent models have revealed that environmental enrichment (EE), in the absence of bladder-directed therapies, leads to amelioration of IC symptoms, implying a central role for the CTRS in symptom precipitation and perpetuation. Conceptually moving the source of IC pain to the brain as a motivational state rather than one resulting from peripheral nociceptive input offers both clinicians and researchers novel opportunities to improve care for patients with IC and for researchers to use more ecologically valid rodent models. It may even be that IC results from an excess of risk to protective factors, making this imbalance a targetable cause rather than a consequence of IC.

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.

Identification of shared pathogenetic mechanisms between COVID-19 and IC through bioinformatics and system biology

COVID-19 increased global mortality in 2019. Cystitis became a contributing factor in SARS-CoV-2 and COVID-19 complications. The complex molecular links between cystitis and COVID-19 are unclear. This study investigates COVID-19-associated cystitis (CAC) molecular mechanisms and drug candidates using bioinformatics and systems biology. Obtain the gene expression profiles of IC (GSE11783) and COVID-19 (GSE147507) from the Gene Expression Omnibus (GEO) database. Identified the common differentially expressed genes (DEGs) in both IC and COVID-19, and extracted a number of key genes from this group. Subsequently, conduct Gene Ontology (GO) functional enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis on the DEGs. Additionally, design a protein-protein interaction (PPI) network, a transcription factor gene regulatory network, a TF miRNA regulatory network, and a gene disease association network using the DEGs. Identify and extract hub genes from the PPI network. Then construct Nomogram diagnostic prediction models based on the hub genes. The DSigDB database was used to forecast many potential molecular medicines that are associated with common DEGs. Assess the precision of hub genes and Nomogram models in diagnosing IC and COVID-19 by employing Receiver Operating Characteristic (ROC) curves. The IC dataset (GSE57560) and the COVID-19 dataset (GSE171110) were selected to validate the models' diagnostic accuracy. A grand total of 198 DEGs that overlapped were found and chosen for further research. FCER1G, ITGAM, LCP2, LILRB2, MNDA, SPI1, and TYROBP were screened as the hub genes. The Nomogram model, built using the seven hub genes, demonstrates significant utility as a diagnostic prediction model for both IC and COVID-19. Multiple potential molecular medicines associated with common DEGs have been discovered. These pathways, hub genes, and models may provide new perspectives for future research into mechanisms and guide personalised and effective therapeutics for IC patients infected with COVID-19.

The Tumor Necrosis Factor-α Level in Platelet-Rich Plasma Might Be Associated with Treatment Outcome in Patients with Interstitial Cystitis/Bladder Pain Syndrome or Recurrent Urinary Tract Infection

Using platelet-rich plasma (PRP) injections to treat urological diseases has attracted great attention. This study investigated the impact of cytokine concentrations in PRP on the treatment outcome of patients with recurrent urinary tract infection (rUTI) and interstitial cystitis/bladder pain syndrome (IC/BPS). Forty patients with IC/BPS and twenty-one patients with rUTI were enrolled for four-monthly repeated PRP injections. PRP was collected at the first injection and analyzed with multiplex immunoassays for 12 target cytokines. In patients with IC/BPS, a Global Response Assessment (GRA) score ≥ 2 was defined as a successful outcome. In rUTI patients, ≤2 episodes of UTI recurrence during one year of follow-up was considered a successful outcome. Nineteen (47.5%) patients with IC/BPS and eleven (52.4%) patients with rUTI had successful outcomes. The IC/BPS patients with successful outcomes had significantly lower levels of tumor necrosis factor-α (TNF-α) in their PRP than those with unsuccessful outcomes (p = 0.041). The rUTI patients with successful outcomes also had a lower level of TNF-α (p = 0.025) and a higher level of epidermal growth factor (p = 0.035) and transforming growth factor-β2 (p = 0.024) in PRP than those with unsuccessful outcomes. A lower level of TNF-α in PRP might be a potentially predictive factor of treatment outcome.

Temporally complex inflammatory networks in an animal model reveal signatures for interstitial cystitis and bladder pain syndrome phenotype

INTRODUCTION AND OBJECTIVE

Interstitial cystitis and bladder pain syndrome (IC/BPS) presents with symptoms of debilitating bladder pain and is typically a diagnosis of exclusion. The cystoscopic detection of Hunner's lesions increases the likelihood of detecting tissue inflammation on bladder biopsy and increases the odds of therapeutic success with anti-inflammatory drugs. However, the identification of this subgroup remains challenging with the current lack of surrogate biomarkers of IC/BPS. On the path towards identifying biomarkers of IC/BPS, we modeled the dynamic evolution of inflammation in an experimental IC/BPS rodent model using computational biological network analysis of inflammatory mediators (cytokines and chemokines) released into urine. The use of biological network analysis allows us to identify urinary proteins that could be drivers of inflammation and could therefore serve as therapeutic targets for the treatment of IC/BPS.

METHODS

Rats subjected to cyclophosphamide (CYP) injection (150 mg/kg) were used as an experimental model for acute IC/BPS (n = 8). Urine from each void was collected from the rats over a 12-h period and was assayed for 13 inflammatory mediators using Luminex™. Time-interval principal component analysis (TI-PCA) and dynamic network analysis (DyNA), two biological network algorithms, were used to identify biomarkers of inflammation characteristic of IC/BPS over time.

RESULTS

Compared to vehicle-treated rats, nearly all inflammatory mediators were elevated significantly (p < 0.05) in the urine of CYP treated rats. TI-PCA highlighted that GRO-KC, IL-5, IL-18, and MCP-1 account for the greatest variance in the inflammatory response. At early time points, DyNA indicated a positive correlation between IL-4 and IL-1β and between TNF-α and IL-1β. Analysis of TI-PCA and DyNA at later time points showed the emergence of IL-5, IL-6, and IFNγ as additional key mediators of inflammation. Furthermore, DyNA network complexity rose and fell before peaking at 9.5 h following CYP treatment. This pattern of inflammation may mimic the fluctuating severity of inflammation associated with IC/BPS flares.

CONCLUSIONS

Computational analysis of inflammation networks in experimental IC/BPS analysis expands on the previously accepted inflammatory signatures of IC by adding IL-5, IL-18, and MCP-1 to the prior studies implicating IL-6 and GRO as IC/BPS biomarkers. This analysis supports a complex evolution of inflammatory networks suggestive of the rise and fall of inflammation characteristic of IC/BPS flares.

Plasma proteomic profiles of pain subtypes in adolescents and young adults with endometriosis

STUDY QUESTION

What are the similarities and differences in the systemic proteomic profiles by endometriosis-associated pain subtypes among adolescents and young adults with endometriosis?

SUMMARY ANSWER

Endometriosis-associated pain subtypes exhibited distinct plasma proteomic profiles.

WHAT IS KNOWN ALREADY

Endometriosis patients, especially those diagnosed in adolescents and young adults, are often plagued by various pain symptoms. However, it is not clear what biological processes underlie this heterogeneity.

STUDY DESIGN, SIZE, DURATION

We conducted a cross-sectional analysis using data and plasma samples from 142 adolescent or young adult participants of the Women's Health Study: From Adolescence to Adulthood cohort with laparoscopically confirmed endometriosis.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We measured 1305 plasma protein levels by SomaScan. We classified self-reported endometriosis-associated pain into subtypes of dysmenorrhea, acyclic pelvic pain, life impacting pelvic pain, bladder pain, bowel pain, and widespread pain phenotype. We used logistic regression to calculate the odds ratios and 95% confidence intervals for differentially expressed proteins, adjusting for age, BMI, fasting status, and hormone use at blood draw. Ingenuity Pathway Analysis identified enriched biological pathways.

MAIN RESULTS AND THE ROLE OF CHANCE

Our study population consisted mainly of adolescents and young adults (mean age at blood draw = 18 years), with nearly all (97%) scored as rASRM stage I/II at laparoscopic diagnosis of endometriosis, which is a common clinical presentation of endometriosis diagnosed at a younger age. Pain subtypes exhibited distinct plasma proteomic profiles. Multiple cell movement pathways were downregulated in cases with severe dysmenorrhea and life impacting pelvic pain compared to those without (P < 7.5×10-15). Endometriosis cases with acyclic pelvic pain had upregulation of immune cell adhesion pathways (P < 9.0×10-9), while those with bladder pain had upregulation of immune cell migration (P < 3.7×10-8) and those with bowel pain had downregulation (P < 6.5×10-7) of the immune cell migration pathways compared to those without. Having a wide-spread pain phenotype involved downregulation of multiple immune pathways (P < 8.0×10-10).

LIMITATIONS, REASONS FOR CAUTION

Our study was limited by the lack of an independent validation cohort. We were also only able to explore any presence of a pain subtype and could not evaluate multiple combinations by pain subtypes. Further mechanistic studies are warranted to elucidate the differences in pathophysiology by endometriosis-pain subtype.

WIDER IMPLICATIONS OF THE FINDINGS

The observed variation in plasma protein profiles by pain subtypes suggests different underlying molecular mechanisms, highlighting the need for potential consideration of pain subtypes for effectively treating endometriosis patients presenting with various pain symptoms.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by the Department of Defense W81XWH1910318 and the 2017 Boston Center for Endometriosis Trainee Award. Financial support for establishment of and data collection within the A2A cohort were provided by the J. Willard and Alice S. Marriott Foundation. N.S., A.F.V., S.A.M., and K.L.T. have received funding from the Marriott Family Foundation. C.B.S. is funded by an R35 MIRA Award from NIGMS (5R35GM142676). S.A.M. and K.L.T. are supported by NICHD R01HD094842. S.A.M. reports serving as an advisory board member for AbbVie and Roche, Field Chief Editor for Frontiers in Reproductive Health, personal fees from Abbott for roundtable participation; none of these are related to this study. Other authors report no conflict of interest.

TRIAL REGISTRATION NUMBER

N/A.

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.

Cannabidiol as a Promising Therapeutic Option in IC/BPS: In Vitro Evaluation of Its Protective Effects against Inflammation and Oxidative Stress

Several animal studies have described the potential effect of cannabidiol (CBD) in alleviating the symptoms of interstitial cystitis/bladder pain syndrome (IC/BPS), a chronic inflammatory disease of the urinary bladder. However, the effects of CBD, its mechanism of action, and modulation of downstream signaling pathways in urothelial cells, the main effector cells in IC/BPS, have not been fully elucidated yet. Here, we investigated the effect of CBD against inflammation and oxidative stress in an in vitro model of IC/BPS comprised of TNFα-stimulated human urothelial cells SV-HUC1. Our results show that CBD treatment of urothelial cells significantly decreased TNFα-upregulated mRNA and protein expression of IL1α, IL8, CXCL1, and CXCL10, as well as attenuated NFκB phosphorylation. In addition, CBD treatment also diminished TNFα-driven cellular reactive oxygen species generation (ROS), by increasing the expression of the redox-sensitive transcription factor Nrf2, the antioxidant enzymes superoxide dismutase 1 and 2, and hem oxygenase 1. CBD-mediated effects in urothelial cells may occur by the activation of the PPARγ receptor since inhibition of PPARγ resulted in significantly diminished anti-inflammatory and antioxidant effects of CBD. Our observations provide new insights into the therapeutic potential of CBD through modulation of PPARγ/Nrf2/NFκB signaling pathways, which could be further exploited in the treatment of IC/BPS.

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.

NLRP3+ macrophages aggravate inflammatory cystitis in diabetes

Inflammatory macrophages play a pivotal role in the progression of inflammatory cystitis. Formation of NOD-, LRR- and PYD domains-containing protein 3 (NLRP3) inflammasome triggers the activation of caspase-1/IL-1β signaling cascades to mediate inflammatory response. However, it is not known whether NLRP3 activation in macrophages during cystitis may differ in normal or diabetic setting as well as the importance of it. In this study, we found that NLRP3 levels significantly increased in bladder macrophages in diabetic mice that underwent cystitis. Moreover, bladder macrophages from diabetic mice appeared to have increased their potential of growth, migration and phagocytosis. Furthermore, specific depletion of NLRP3 in macrophages alleviated the severity of cystitis in diabetic mice, but not in non-diabetic mice. Together, our data suggest that NLRP3 depletion in macrophages may be a promising strategy for treating diabetic cystitis.

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.

Transient receptor potential vanilloid type 4 (TRPV4) in urinary bladder structure and function

Bladder pain syndrome (BPS)/interstitial cystitis (IC) is a urologic, chronic pelvic pain syndrome characterized by pelvic pain, pressure, or discomfort with urinary symptoms. Symptom exacerbation (flare) is common with multiple, perceived triggers including stress. Multiple transient receptor potential (TRP) channels (TRPA1, TRPV1, TRPV4) expressed in the bladder have specific tissue distributions in the lower urinary tract (LUT) and are implicated in bladder disorders including overactive bladder (OAB) and BPS/IC. TRPV4 channels are strong candidates for mechanosensors in the urinary bladder and TRPV4 antagonists are promising therapeutic agents for OAB. In this perspective piece, we address the current knowledge of TRPV4 distribution and function in the LUT and its plasticity with injury or disease with an emphasis on BPS/IC. We review our studies that extend the knowledge of TRPV4 in urinary bladder function by focusing on (i) TRPV4 involvement in voiding dysfunction, pelvic pain, and non-voiding bladder contractions in NGF-OE mice; (ii) distention-induced luminal ATP release mechanisms and (iii) involvement of TRPV4 and vesicular release mechanisms. Finally, we review our lamina propria studies in postnatal rat studies that demonstrate: (i) the predominance of the TRPV4+ and PDGFRα+ lamina propria cellular network in early postnatal rats; (ii) the ability of exogenous mediators (i.e., ATP, TRPV4 agonist) to activate and increase the number of lamina propria cells exhibiting active Ca2+ events; and (iii) the ability of ATP and TRPV4 agonist to increase the rate of integrated Ca2+ activity corresponding to coupled lamina propria network events and the formation of propagating wavefronts.