The effects of a galectin-3 inhibitor on bladder pain syndrome in mice with cyclophosphamide-induced cystitis.

AIMS: To explore the effect of blocking galectin-3 in the bladder pain syndrome associated with interstitial cystitis. METHODS: A galectin-3 inhibitor was used to treat mice with cyclophosphamide-induced cystitis. The expression of galectin-3 in bladder tissues and urine was examined by immunohistochemistry and enzyme-linked immunosorbent assay (ELISA), respectively. Suprapubic-pelvic pain, bladder voiding, bladder pain-like nociceptive behavior, and referred hyperalgesia were assessed. The weights of the bladders were also measured, and inflammatory cell infiltration and inflammatory cytokine levels were examined by histopathological evaluation. The inflammatory cytokines interleukin 1ß (IL-1ß), nerve growth factor (NGF), IL-6, and tumor necrosis factor α (TNF-α) were measured by ELISA. RESULTS: Increases in galectin-3 levels, inflammation, bladder weight, and bladder pain-related symptoms were observed in bladders with cyclophosphamide-induced cystitis. Administration of the galectin-3 inhibitor significantly mitigated bladder pain-related symptoms and inflammatory response. In response to the 500 µM dose of the galectin-3 inhibitor, nociceptive behaviors, nociceptive score, and bladder-to-body weight ratios were reduced by 65.1%, 65.3%, and 40.3%, respectively, while 500 µM Gal-3 inhibitor increased pelvic pain threshold by 86.7%. Moreover, galectin-3 inhibitor treatment inhibited the inflammation. Compared to untreated CYP-induced mice, there were significant changes in the levels of IL-1ß (41.72 ± 2.05 vs. 18.91 ± 2.26 pg/mg tissues), NGF (9.64 ± 0.38 vs. 1.88 ± 0.05 pg/mg tissues), IL-6 (42.67 + 1.51 vs. 21.26 + 2.78 pg/mg tissues, and TNF-α (22.02 ± 1.08 vs. 10.70 ± 0.80 pg/mg tissues) in response to the highest dose of the Gal-3 inhibitor subgroup (500 µM), and 500 µM Gal-3 inhibitor reduced mast cell infiltration ratios by 71.8%. CONCLUSIONS: The galectin-3 inhibitor relieved pelvic pain, urinary symptoms, and bladder inflammation in mice with cyclophosphamide-induced cystitis. Thus, galectin-3 inhibitors may be novel agents in interstitial cystitis treatment.

Pentosan polysulfate and a pigmentary maculopathy: causation versus correlation?

INTRODUCTION: Interstitial cystitis (IC) is a chronic disease with urinary tract symptoms and pain. Pentosan polysulfate (PPS) is the only U.S. Food and Drug Administration approved oral medication for the treatment of IC pain and symptoms. Recently, articles described a pigmentary maculopathy in IC patients on long term PPS therapy. Currently, there is no definitive study directly linking PPS as the cause of the pigmentary maculopathy. The aim of this review is to evaluate if PPS is the causative factor of the pigmentary maculopathy or if PPS use is only associated with the pigmentary maculopathy. MATERIALS AND METHODS: A comprehensive review of peer reviewed journals using the search terms IC, maculopathy, mast cells, immune inflammatory components, Tamm-Horsfall protein, cations and tight junctions was performed to examine the pathophysiology and role of chronic inflammation in IC and known retinal maculopathies. RESULTS: Chronic inflammatory cells have been reported in age-related macular degeneration choroid blood vessels and in bladder submucosal and detrusor layers in IC patients. Studies in IC and maculopathies demonstrate a significant milieu of activated chronic inflammatory and immunologic responses that cause a more "leaky" epithelium and a subsequent cascade of inflammatory events that results in the pathological changes seen in these two conditions. CONCLUSIONS: After an analysis of the literature describing a pigmentary maculopathy in IC patients on long term PPS, a causal relationship does not appear to be present. An alternate model is proposed postulating that the causative factor for the pigmentary maculopathy is the underlying inflammatory state associated with IC and not PPS use.

Uroprotective Potential of Campesterol in Cyclophosphamide Induced Interstitial Cystitis; Molecular Docking Studies.

Cyclophosphamide (CYP) is commonly used to treat cancer of the ovaries, breast, lymph, and blood system and produces interstitial cystitis (IC) via its urotoxic metabolite: i. e., acrolein. The present study was aimed to investigate the uroprotective effect of campesterol (a steroidal phytochemical) in cyclophosphamide induced IC. IC was induced by CYP (150 mg/kg, i. p.) in rats. The Enzyme linked immunosorbent assays for oxidative stress markers and Polymerase Chain Reaction (PCR) for inflammatory cytokines were carried out. The Tissue Organ Bath Technique was used for the evaluation of the spasmolytic effect of campesterol. Different pharmacological antagonists have been used to explore the mechanism of action of campesterol. Treatment with campesterol (70 mg/kg) reduced nociception (55 %), edema (67 %), hemorrhage (67 %), and protein leakage significantly (94 %). The antioxidant activity of campesterol was exhibited by a fall in MDA, NO, and an elevation in SOD, CAT, and GPX levels. Campesterol presented anti-inflammatory potential by decreasing IL-1, TNF-α, and TGF-ß expression levels. Histologically, it preserved urothelium from the deleterious effect of CYP. Campesterol showed a spasmolytic effect by reducing bladder overactivity that was dependent on muscarinic receptors, voltage-gated calcium and KATP channels, and cyclo-oxygenase pathways. In silico studies confirmed the biochemical findings. The findings suggest that campesterol could be valorized as a possible therapeutic agent against cyclophosphamide-induced interstitial cystitis.

Serpina3n/serpina3 alleviates cyclophosphamide-induced interstitial cystitis by activating the Wnt/ß-catenin signal.

BACKGROUND/OBJECTIVE: Serpina3n/Serpina3 has been identified to be implicated in inflammatory diseases, but its role in interstitial cystitis/bladder pain syndrome (IC/BPS) remains unknown. Here, we aimed to reveal serpina3n/serpina3 role in IC/BPS in vivo and in vitro. METHODS: The IC/BPS model in mice was induced by intraperitoneal injection of 150 mg/kg of cyclophosphamide (CYP). HE and toluidine blue staining were used for histology assessment. Serpina3n/serpina3 expression in the bladder tissues from IC/BPS patients and mouse models were determined by qPCR, immunohistochemistry and western blotting. XAV-939 treatment was applied to inhibit ß-catenin activation. Serpina3 role in modulating the growth and apoptosis of HBlEpCs, a human primary bladder epithelial cell line, was assessed by CCK-8 and flow cytometry assays. RESULTS: Serpina3n/serpina3 expression was decreased in both human and mice bladder tissues with IC/BPS. Upregulation of serpina3n significantly alleviated CYP-induced bladder injury, with decreased mast cells and pro-inflammatory factor levels, including IL-1ß, IL-6, and TNF-α, while increased IL-10 level. In addition, serpina3 overexpression inhibited the apoptosis of HBlEpCs, and increased cell growth. In mechanism, we found that serpina3 overexpression promoted the activation of wnt/ß-catenin signaling. And, the inhibition of wnt/ß-catenin signaling with XAV-939 abolished serpina3n/serpina3 role in protecting bladder tissues from CYP-induced cystitis, as well as inhibiting HBlEpC apoptosis. CONCLUSION: Serpina3n/serpina3 expression was decreased in IC/BPS. Overexpression of serpina3n could alleviate CYP-induced IC/BPS by activating the Wnt/ß-catenin signal. This study may provide a new therapeutic strategy for IC/BPS.

4-PBA inhibits endoplasmic reticulum stress to improve autophagic flux in the treatment of protamine/lipopolysaccharide-induced interstitial cystitis in rats.

Interstitial cystitis (IC) has severe clinical symptoms with unclear mechanism. The continuous inflammatory response of the bladder is the basis of its pathogenesis. Endoplasmic reticulum stress (ERS) is involved in the regulation and development of various inflammatory diseases. And autophagy plays an important role in IC. In this study, we mainly focus on the therapeutic effect of endoplasmic reticulum stress and autophagy on protamine/lipopolysaccharide-induced interstitial cystitis. Female Sprague-Dawley rats were randomized into three experimental groups as follows: sham controls(N), IC alone, and IC+4-PBA.Rats in group IC received 10 mg/ml PS in the urinary bladder, followed by 2 mg/ml LPS instillation after 30 min, IC+4-PBA group SD rats received 4-PBA solution administered intragastrically once a day for 5 days. ERS biomarker (GRP78), autophagy-related proteins (LC3I/II, and Beclin1), autophagic flux biomarker (P62), inflammatory biomarkers (IL-6, TNF-a, NF-κB), apoptotic biomarkers (Caspase 3, Bax) were highest in the IC group compared to IC+4-PBA group and N group and the biomarkers expression in IC+4-PBA group were lower than in the IC group, anti-apoptotic biomarker (Bcl-2) was highest in the N group compared to the IC group and IC+4-PBA group and lower in the IC group than in the IC+4-PBA group, oxidative stress biomarkers (HO-1, NQO-1) were remarkably lower in the control group than in the IC and IC+4-PBA groups and notably lower in the IC group than in the IC+4-PBA group. The histological score and mast cell count demonstrated most severe in the IC group than those in the IC+4-PBA group. TUNEL assay examined the level of apoptosis in IC group was higher than in the IC+4-PBA group. The bladder micturition function was significantly improved with 4-PBA treatment. 4-PBA inhibits ERS to recover autophagic flux, and then to suppress the bladder oxidative stress, the inflammatory reaction and apoptosis, finally improve the bladder urinary function in Protamine/Lipopolysaccharide (PS/LPS) induced IC.

Choreito, a Kampo medicine attenuates detrusor overactivity and bladder pain symptoms in rat tranilast-induced interstitial cystitis/bladder pain syndrome-like model.

AIMS: Interstitial cystitis/bladder pain syndrome (IC/BPS) is a chronic inflammatory condition of the bladder. However, there are only a few medicines that are of pharmaceutical grade and reliably effective for IC/BPS symptoms. Choreito (CRT) is a pharmaceutical-grade Kampo medicine and has been widely prescribed for patients of lower urinary tract symptoms (LUTS) and BPS in Japan. In this study, we exploratory investigated the effects of CRT on the IC/BPS-like symptoms induced by tranilast. METHODS: The rat IC/BPS-like model was induced by feeding administration with 0.4% tranilast. The rats were divided into the three following treatment groups: normal diet (Normal), tranilast treatment (Control), and the groups of 1% CRT (CRT) treatment for IC/BPS-like model. After 4 weeks, continuous cystmetry, locomotor, and vascular permeability was assessed. Furthermore, the cytokine levels in bladder were analyzed by the Bio-Plex suspension array system and plasma monoamine were measured. RESULTS: Control group exhibited 14.3% decrease of locomotor activity in the dark period, and which were 20.3% increase by 1%CRT treatment. The voiding interval was shorter in control than in other groups. 1%CRT suppressed the shortening of voiding interval. Evans blue leakage of bladder wall observed 44.8% higher in control group than in the normal group. The leakage of 1%CRT group was 33.3% less than in the control group. The cytokine level of IFNγ and VEGF were elevated in the control, and CRT treatment suppressed the elevation of IFNγ in the bladder. Plasma noradrenaline was significantly reduced by CRT treatment compared normal group. CONCLUSION: These results suggest that CRT can be an effective therapeutic agent for the treatment of IC/BPS-like symptoms.

[Urodynamic and histological evaluation of cyclophosphamide-induced bladder pain syndrome in SD rats].

OBJECTIVE: To establish a model of bladder pain syndrome in SD rats by cyclophosphamide intraperitoneal injection, to evaluate the effectiveness of the model from the urodynamic and histological levels, to lay a zoological foundation for the clinical study of bladder pain syndrome, and to further guide clinical treatment. METHODS: Thirty-two 8-week-old SD rats were randomly divided into 4 groups, including acute test group, acute control group, chronic test group, and chronic control group, with 8 rats in each group. The acute test group received intraperitoneal injection of cyclophosphamide 150 mg/kg immediately after the measurement of urodynamic data on the first day, and urodynamic examination was performed again 2 days later. After that, the rats were sacrificed to obtain bladder tissue. In the chronic test group, after measuring the baseline data of urodynamics on the first day, cyclophosphamide 75 mg/kg was intraperitoneally injected on the first, fourth, and seventh days, and the rats were sacrificed after measuring the urodynamic data again on the eighth day to obtain bladder tissue. The acute control group and the chronic control group were injected with the same amount of normal saline during intraperitoneal injection, and the urodynamic testing time point were consistent with the corresponding test groups. Histopathological changes of the bladder were assessed by HE staining. RESULTS: In each acute and chronic group, there were no intragroup differences in baseline urodynamic levels between the test and control groups. The urodynamic maximum bladder volume was significantly reduced in the acute test group after administration(t=-2.961, P < 0.05), histologically, severe interstitial edema, obvious inflammatory cell infiltration, mucosal edema and submucosal hemorrhage, and partial urothelium were absent could be seen, which were consistent with acute cystitis performance. The urodynamic maximum bladder capacity was significantly reduced in the chronic test group after administration (t=-3.886, P < 0.05), and the bladder compliance was lower than that in the control group, but not significant, the histological manifestations were urothelial exfoliation, interstitial edema, submucosal hemorrhage, infiltration of inflammatory cells such as lymphocytes, and dense vascular distribution. CONCLUSION: In the acute test group, a single intraperitoneal injection of cyclophosphamide could induce acute bladder inflammation in the rats. In the chronic test group, repeated injections of cyclophosphamide could induce histological changes in chronic inflammation of chronic bladder pain syndrome in the rats. But the bladder function was not significantly impaired.

The NLRP3 Inflammasome Inhibitor Dapansutrile Attenuates Cyclophosphamide-Induced Interstitial Cystitis.

Interstitial cystitis (IC)/bladder pain syndrome (BPS), hereafter referred together as IC, is a clinical syndrome characterized by sterile inflammation in the bladder. While the etiology and pathophysiology of IC remain unclear, it may involve autoimmunity in light of the significant role played by the NLRP3 inflammasome. However, the effect of NLRP3 inhibitors including dapansutrile (Dap) on IC had not been explored previously. Here, we investigated the effect of Dap in the cyclophosphamide (CYP)-induced experimental mouse model of IC, which results in functional and histological alterations confined to the urinary bladder (UB) comparable to that of clinical IC. CYP-induced mice treated with Dap exhibited improved UB pathology and reductions in inflammation scores and the frequency and the number of mast cells and neutrophils, relative to mice that received CYP alone. Dap- and CYP-treated mice also exhibited infiltration of T cells in the spleen and iliac lymph nodes (ILNs) and a concurrent significant decrease (p<0.01) in CXCR3+CD8+ T cells in the UB, induction of systemic and mucosal dendritic cells (DCs), and reduced levels of systemic proinflammatory cytokines, as compared to CYP alone. We also observed decreases in the expression of several signaling pathways regulators, including interleukin-1 beta (IL-1ß), NLRP3, caspase-1, nuclear factor kappa B (NF-κB), and inducible nitric oxide synthase (iNOS) in the UB of CYP- and Dap-treated mice, relative to those receiving CYP alone. Taken together, these results suggest that Dap suppresses IC through the reduction of CXCR3+T cells, mast cells, and neutrophils in the UB and induces DCs as a protective measure. The present study identifies the mechanisms underlying the amelioration of IC by the NLRP3 inhibitor Dap and may provide an avenue for a potential therapeutic agent for the treatment of IC.

Echinacoside Ameliorates Cyclophosphamide-Induced Bladder Damage in Mice.

Interstitial cystitis (IC) is featured by apoptosis and chronic inflammation in bladder tissue. We aimed to evaluate the effect of echinacoside (ECH), which is known to modulate inflammation and apoptosis on IC using relevant models. We established a mouse model of cystitis using cyclophosphamide (CYP) and treated human urothelium cells (SV-HUC-1) with lipopolysaccharide (LPS) + ATP as in vitro model. The bladder function was tested by urodynamics. Apoptosis of bladder cells was assessed by terminal deoxynucleotidyl transferase dUTP nick-end labeling assay. Expressions of apoptosis-associated and inflammation-related proteins were assessed using western blotting. Treatment with ECH significantly improved bladder function, reduced inflammatory damage, and decreased apoptosis in the models. Furthermore, ECH decreased the phosphorylation levels of IκB and NF-κB(p65), and upregulated the expression of peroxisome proliferator-activated receptor gamma (PPARγ), which are related to apoptosis and inflammation in CYP-induced mouse cystitis. Moreover, ECH did not reduce apoptosis of urothelial cells after treatment with PPARγ antagonist GW9662. Our findings suggest that ECH might have protective effect against IC in bladder and be mediated through modulation of the PPARγ/NF-κB pathway.

Age-Related Macular Degeneration Masquerade: A Review of Pentosan Polysulfate Maculopathy and Implications for Clinical Practice.

ABSTRACT: Pentosan polysulfate (PPS) sodium (Elmiron) is the only Food and Drug Administration (FDA)-approved oral medication to treat interstitial cystitis, also known as bladder pain syndrome. A symptomatic pigmentary maculopathy associated with PPS was reported in 2018. Since then, recognition of this unique drug toxicity has increased rapidly. This potentially sight-threatening side effect prompted the FDA in June 2020 to update the label for PPS to warn about "retinal pigmentary changes." A challenging feature of pentosan maculopathy is its ability to mimic many other retinal conditions, including inherited retinal dystrophies such as pattern dystrophy, mitochondrially inherited diabetes and deafness, and Stargardt disease, and age-related macular degeneration. In this review, we discuss the history of PPS maculopathy and its implications for thousands of at-risk interstitial cystitis patients. We use published literature and an illustrative case from our institution to highlight the importance of diagnosing PPS maculopathy. We also compare PPS maculopathy to age-related macular degeneration, explain why differentiating between the 2 is clinically important, and highlight avenues for further research. Finally, we highlight the paucity of data on patients of color and why this lack of understanding may impact patient care.

Activation of translocator protein alleviates mechanical allodynia and bladder dysfunction in cyclophosphamide-induced cystitis through repression of BDNF-mediated neuroinflammation.

BACKGROUND: Bladder pain syndrome/interstitial cystitis (BPS/IC) is a refractory disease accompanied by bladder-related pain and hyperactivity. Studies have shown that the translocator protein (TSPO) modulates neuroinflammation and central sensitisation associated with pain. Moreover, we previously demonstrated that brain-derived neurotrophic factor (BDNF) regulates neuroinflammation and mechanical allodynia in cyclophosphamide (CYP)-induced cystitis through activation of glial cells. Here, we aimed to explore whether activation of TSPO attenuates mechanical allodynia and bladder dysfunction by regulating BDNF induced neuroinflammation in a CYP-induced cystitis model. METHODS: Injection of CYP was performed to form a rat model of BPS/IC. The expression of TSPO was regulated by intrathecal injection of the TSPO agonist Ro5-4864. The von Frey filament test was applied to evaluate suprapubic allodynia. Bladder function was assessed using filling cystometry. Western blotting was used to detect the expression of TSPO, BDNF, GFAP, Iba-1, p-p38, p-JNK, TNF-α, and IL-1ß, and double immunofluorescence was performed to localise TSPO in the L6-S1 spinal dorsal horn (SDH). RESULTS: TSPO was activated in the SDH after CYP injection and was primarily colocalised with astrocytes. Ro5-4864 reversed mechanical allodynia and bladder dysfunction induced by CYP. Moreover, the upregulation of BDNF and activation of astrocytes and microglia was suppressed by Ro5-4864, resulting in downregulation of p-p38, p-JNK, TNF-α, and IL-1ß. CONCLUSIONS: Ro5-4864 alleviated mechanical allodynia and bladder dysfunction in the CYP model, possibly by inhibiting the elevation of BDNF and consequent activation of astrocytes and microglia induced neuroinflammation. TSPO may be a potential target for the treatment of BPS/IC. SIGNIFICANCE: This study examined the mechanism underlying the ability of the translocator protein to modulate bladder pain syndrome/interstitial cystitis.

Risk of maculopathy with pentosan polysulfate sodium use.

AIMS: Recent epidemiologic studies have examined the risk of maculopathy with pentosan polysulfate sodium (PPS), a drug indicated for the treatment of interstitial cystitis. However, results have been contradictory. Thus, we quantified the risk of maculopathy with PPS with a focus on risk with duration of use. METHODS: We used a new user, retrospective cohort study with an active comparator. We created a cohort of mutually exclusive 6221 PPS users and 89 744 amitriptyline users, a tricyclic antidepressant also used for the treatment of pain secondary to interstitial cystitis. Subjects were selected from the PharMetrics Plus database (IQVIA, Durham, NC) from 2006 to 2020. Cohort members were followed to the first event of the study outcome (maculopathy) or end of enrolment. A Cox regression model was constructed to adjust for potential confounders. RESULTS: The mean follow-up was 3.0 years for PPS users and amitriptyline users. The adjusted hazard ratio (HR) for maculopathy in PPS users was 2.64 (95% confidence interval [CI]: 1.90-3.68). The HR for the sensitivity analysis that combined maculopathy and age-related macular degeneration (AMD) was 1.38 (95% CI: 1.16-1.65). A cumulative duration-response pattern was observed, with use greater than 3 years having a 9.5-fold risk of maculopathy (HR = 9.56, 95% CI: 3.60-25.37) compared to a 2.3-fold risk of maculopathy with use for 1 year or less (HR = 2.27, 95% CI: 1.50-3.43). The number needed to harm for the first 4 years of use was 250. CONCLUSIONS: The results of this study suggest an increased risk of maculopathy with PPS use, particularly with longer duration of use.

Trypsin-induced elevated contractile responses in a rat model of interstitial cystitis/bladder pain syndrome: Involvement of PAR2 and intracellular Ca2+ release pathways.

AIMS: Interstitial cystitis/bladder pain syndrome (IC/BPS) is a chronic inflammatory disease with unclear etiology. Different receptors play a role in the pathophysiology including protease activated receptors (PARs). The present study aimed to investigate the subtypes and the effects of PARs on contractility using permeabilized detrusor smooth muscle strips in IC/BPS. MAIN METHODS: IC/BPS was induced by cyclophosphamide injection. Histopathological analysis, PCR for detecting PAR proteins, western blotting for indicating PAR2 protein expression levels and myograph recording for measuring contractile force were used. KEY FINDINGS: The present study reveals that in rat bladder PAR1 and PAR2 but not PAR4 were found to be expressed. The first evidence was revealed where trypsin-induced contractions in rat permeabilized detrusor were potentiated in CYP-induced cystitis. Moreover, the functional inhibition of trypsin-induced contractions by selective PAR2 antagonist (ENMD-1068) and the supporting immunoblotting results emphasized that the main PAR subtype involved in IC/BPS model in rat bladder is PAR2. Our data emphasize the prominent role of IP3 in cystitis pathology besides ryanodine channels. Trypsin-induced Ca2+sensitization contractions were also higher in cystitis. Both Rho kinase and protein kinase C played a role in this increased Ca2+sensitization situation. SIGNIFICANCE: The present paper highlights the intracellular pathways that are involved in trypsin-induced contractions mainly via PAR2 in permeabilized bladder detrusor smooth muscle in a rat model of IC/BPS.

Association Between Pentosan Polysulfate Sodium and Retinal Disorders.

IMPORTANCE: Case series have identified a macular condition hypothesized to be associated with the use of pentosan polysulfate sodium (PPS). Observational studies seeking to quantify this association have yielded equivocal results. OBJECTIVE: To estimate the association between PPS exposure and maculopathy. DESIGN, SETTING, AND PARTICIPANTS: This disproportionality analysis was conducted using the US Food and Drug Administration Adverse Event Reporting System from January 2013 through June 2020. EXPOSURE: Adverse event reports for pentosan polysulfate were selected and compared with adverse event reports associated with drugs taken for the following indications: interstitial cystitis, cystitis, bladder disorder, or bladder pain. MAIN OUTCOME MEASURES: Retinal adverse events were identified using the retinal disorders Standardized Medical Dictionary for Regulatory Activities (MedDRA) Query, which includes conditions associated with retinal damage attributable to blockage of its blood supply, nutritional deficiencies, toxins, and diseases affecting the retina. RESULTS: There were 2775 reports available for analysis in the PPS group (of which 1966 were for women [70.9%]) and 6833 reports in the other drugs group (of which 4036 [59.1%] were for women). The proportion of adverse events for any macular event relative to all other events was elevated for the users of PPS compared with those using other interstitial cystitis and bladder pain drugs (proportionate reporting ratio [PRR], 1.21 [95% CI, 1.01-1.44]). With respect to specific retinal conditions, macular degeneration (20 [0.8%] vs 15 [0.2%]), maculopathy (83 [3.4%] vs 2 [0.03%]), retinal dystrophy (3 [0.1%] vs 0), retinal injury (5 [0.2%] vs 0), and retinal toxicity (3 [0.1%] vs 0) were proportionately more common among users of PPS compared with those using other interstitial cystitis and bladder pain drugs, respectively. CONCLUSIONS AND RELEVANCE: The results of the current study add to the growing evidence that PPS use is associated with an increased risk of maculopathy. Studies that rule out prevalent retinal abnormalities prior to the initiation of PPS would strengthen the current body of literature.

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

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

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-ß 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.

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.