Increased Expression of Hypoxia-inducible Factor-1α and Vascular Endothelial Growth Factor Associated With Glomerulation Formation in Patients With Interstitial Cystitis

Elucidation of the pathophysiology of interstitial cystitis/bladder pain syndrome via experimental autoimmune cystitis rat model

Although the cause of interstitial cystitis/painful bladder syndrome (IC/PBS) remains unknown, autoimmune involvement has been strongly suggested to be a contributing factor. To elucidate the pathophysiology of IC/PBS, we characterized the experimental autoimmune cystitis (EAC) in rats. Adult female Sprague-Dawley rats were divided into the EAC and control groups. The EAC rats were generated by administrating a homogenate of donor rat bladder tissue as a bladder antigen. The characteristics of the two groups were determined by evaluating pain behavior and conducting cystometry, histopathology, and molecular analyses. The EAC rats showed: 1) a decreased paw withdrawal threshold, 2) a reduced intercontraction interval on cystometry, 3) the irregular surfaces of the umbrella cells of epithelium throughout the bladder wall, 4) accumulation of stress granules in the bladder and vascular endothelium, 5)the increased expression of genes related to inflammation and ischemia at the mRNA and protein levels, 6) a significantly increased paw withdrawal threshold with pain treatment, and 7) the induction of glomerulation of the bladder wall, epithelium denudation, and lymphocyte infiltration in the interstitium by bladder distension. These results suggest that the EAC rats showed pain and frequent urination with the overexpression of inflammatory chemokines, reflecting clinical IC/BPS, and the bladder epithelium and vascular endothelium may be the primary sites of IC/BPS, and bladder injury, such as bladder distension, can cause progression from BPS to IC with Hunner lesions.NEW & NOTEWORTHY The experimental autoimmune cystitis model rats showed pain and frequent urination with the overexpression of inflammatory chemokines, reflecting clinical interstitial cystitis/painful bladder syndrome (IC/PBS), and the bladder epithelium and vascular endothelium may be the primary sites of IC/BPS, and bladder injury, such as bladder distension, can cause progression from BPS to IC with Hunner lesions.

Therapeutic Approaches for Urologic Chronic Pelvic Pain Syndrome; Management: Research Advances, Experimental Targets, and Future Directions

Urologic chronic pelvic pain syndrome (UCPPS) is a painful chronic condition with persistent pain originating from the pelvis that often leads to detrimental lifestyle changes in the affected patients. The syndrome develops in both sexes, with an estimated prevalence of 5.7% to 26.6% worldwide. This narrative review summarizes currently recommended therapies for UCPPS, followed by the latest animal model findings and clinical research advances in the field. The diagnosis of UCPPS by clinicians has room for improvement despite the changes in the past decade aiming to decrease the time to treatment. Therapeutic approaches targeting growth factors (i.e., nerve growth factor, vascular endothelial growth factor), amniotic bladder therapy, and stem cell treatments gain more attention as experimental treatment options for UCPPS. The development of novel diagnostic tests based on the latest advances in urinary biomarkers would be beneficial to assist with the clinical diagnosis of UCPPS. Future research directions should address the role of chronic psychologic stress and the mechanisms of pain refractory to conventional management strategies in UCPPS etiology. Testing the applicability of cognitive behavioral therapy in this cohort of UCPPS patients might be promising to increase their quality of life. The search for novel lead compounds and innovative drug delivery systems requires clinically relevant translational animal models. The role of autoimmune responses triggered by environmental factors is another promising research direction to clarify the impact of the immune system in UCPPS pathophysiology. SIGNIFICANCE STATEMENT: This minireview provides an up-to-date summary of the therapeutic approaches for UCPPS with a focus on recent advancements in the clinical diagnosis and treatments of the disease, pathophysiological mechanisms of UCPPS, signaling pathways, and molecular targets involved in pelvic nociception.

Urine biomarker could be a useful tool for differential diagnosis of a lower urinary tract dysfunction

A precision diagnosis of lower urinary tract dysfunctions (LUTD) such as bladder outlet obstruction, detrusor overactivity (DO), interstitial cystitis/bladder pain syndrome (IC/BPS), dysfunctional voiding (DV), or detrusor underactivity (DU) needs invasive videourodynamic study. Exploring non-invasive tools to help screening LUTD is necessary for clinicians in their daily practice. This article reviews recently clinical studies of using urinary inflammatory proteins and oxidative stress biomarkers in the identification of specific LUTD among men and women with lower urinary tract symptoms (LUTS). Some important findings have been reported: (1) Using urine chemokines CXCL-1 and interleukin-8 (IL-8), we may discriminate overactive bladder (OAB) symptoms in women between DO and urinary tract infection. (2) Urinary levels of oxidative stress biomarkers such as 8-hydroxydeoxyguanosine (8-OHdG) and 8-isoprostane have a potential being used as a tool to identify women with mixed DO and stress urinary incontinence. (3) Urine levels of total antioxidant capacity (TAC), and prostaglandin E2 (PGE2) are positively correlated with voiding detrusor pressure in patients with DU. (4) Urine levels of brain-derived neurotrophic factor (BDNF) and PGE2 were significantly higher in the DU patients with detrusor function recovery. (5) Women with DV had higher urinary levels of tumor necrosis factor-alpha (TNF-α) and 8-OHdG, and urinary IL-2 level was significantly lower. (6) Urine level of 8-isoprostane was higher in the patients with idiopathic DO and neurogenic DO. (7) Higher urine cytokine levels of monocyte chemoattractant protein-1 (MCP-1), regulated on activation, normal T-cell expressed and secreted (RANTES), CXCL-10, IL-7, and eotaxin-1 in patients with IC/BPS than controls. (8) The urine levels of IL-8, CXCL-10, BDNF, IL-6, and RANTES were significantly higher in patients with Hunner's IC than non-Hunner's IC. (9) Male patients with IC/BPS had a significantly higher level of eotaxin, MCP-1, TNF-α, 8-OHdG, and TAC. Combining a higher eotaxin and a higher TNF-α can provide a satisfactory diagnostic value in discriminating IC/BPS from other LUTD in men. These studies provide evidence that measurement of cluster of urine biomarkers could be used as a diagnostic tool to differentiate different LUTD in patients with similar LUTS.

Latest insights into the pathophysiology of bladder pain syndrome/interstitial cystitis

PURPOSE OF REVIEW

Bladder pain syndrome/interstitial cystitis (BPS/IC) is a common medical problem in both sexes affecting people of all ages. Patients might report overactive bladder symptoms with additional bladder pain at maximum bladder filling, during and after micturition. This review aims to highlight pathophysiological mechanisms associated with this disease.

RECENT FINDINGS

Latest literature exposes different pathophysiological mechanisms such as impaired urothelial barrier function, alteration of urothelial factors and cytokines, chronic inflammation, vascular lesions, neurogenic inflammation and processes in the central nervous system leading to central sensitization. According to the involved mechanisms, BPS/IC may be arranged in clusters according to the clinical phenotype thus helping in clinical decision-making and treatment. Moreover, patients with BPS/IC suffer from other comorbidities such as fibromyalgia, irritable bowel syndrome, chronic pain and functional syndromes and psychosomatic diseases making the management challenging for medical professionals.

SUMMARY

Bladder pain syndrome/interstitial cystitis is a complex heterogeneous medical condition involving different pathomechanisms leading to bladder pain and dysfunction, consequently, impairing quality-of-life in affected individuals. However, these mechanisms are still not fully understood, so that patient treatments often remain unsatisfactory. For this reason, continuing research is important to understand the underlying pathomechanisms to discover biomarkers and treatment targets eventually improving diagnostic and therapeutic measures of BPS/IC.

Therapeutic effects of axitinib, an anti-angiogenic tyrosine kinase inhibitor, on interstitial cystitis

To investigate the therapeutic effects of axitinib, a tyrosine kinase inhibitor, in an interstitial cystitis (IC) rat model. IC patients with or without Hunner lesion and non-IC controls were enrolled (n = 5/group). Bladder tissues were stained with vascular endothelial growth factor (VEGF), VEGF receptor 2 (VEGFR-2), platelet-derived growth factor (PDGF), and PDGF receptor B (PDGFR-B). The IC group showed extensive VEGFR-2 and PDGFR-B staining compared with controls. Next, ten-week-old female Sprague Dawley rats were divided into three groups (n = 10/group): sham, hydrochloride (HCl), and axitinib groups. One week after HCl instillation (day 0), the axitinib group received oral axitinib (1 mg/kg) for five consecutive days and pain was evaluated daily. Bladder function, histology and genetics were evaluated on day 7. The pain threshold significantly improved 3 days after axitinib administration. Axitinib decreased non-voiding contraction and increased the micturition interval and micturition volume and alleviated urothelial denudation, angiogenesis, mast cell infiltration, and fibrosis. HCl instillation increased the expression of tyrosine kinase receptors, including VEGFR-2 and PDGFR-B; axitinib administration inhibited their expression. Oral administration of axitinib improved pain, voiding profiles, and urothelial integrity by inhibiting angiogenesis in IC rat model. Axitinib may have potential therapeutic efficacy in IC patients.

Urinary Oxidative Stress Biomarker Levels Might Be Useful in Identifying Functional Bladder Disorders in Women with Frequency and Urgency Syndrome

Purpose: lower urinary tract dysfunctions (LUTDs) are difficult to diagnose based on symptoms. This study used a cluster of urinary biomarkers, including inflammatory cytokines, neurogenic proteins, and oxidative stress biomarkers, to identify LUTDs in women with frequency and urgency symptoms. Methods: in total, 253 women with video urodynamics (VUDS)- and cystoscopy-confirmed detrusor overactivity (DO), interstitial cystitis/bladder pain syndrome (IC/BPS), dysfunctional voiding (DV), and hypersensitive bladder (HSB), and normal controls were included. Before diagnosis and treatment, urine samples were collected for analysis of biomarkers. The urine levels of biomarkers were compared between groups with bladder dysfunctions and controls and were combined to test the sensitivity in identifying total pathological bladder diseases and specific bladder diseases. Results: After video urodynamic study, VUDS, and urological examinations, bladder dysfunctions were classified into DO (n = 31), IC/BPS (n = 114), DV (n = 45), HSB (n = 29), and control (n = 34) groups. By using a cystomeric bladder capacity of ≤350 mL, 186/219 (84.9%) of the patients with DO, IC/BPS, DV, and HSB can be discriminated from the controls. Among these urine biomarkers, oxidative stress biomarkers 8-isoprostane, 8-hydroxydeoxyguanosine (8-OHdG), or total antioxidant capacity (TAC) are useful for identifying pathological bladder dysfunction (DO, IC/BPS, and DV) and HSB. With elevated IL-1β and lower IL-2, and elevated TNF-α levels, most patients with DV can be identified. Between DO and IC/BPS, a higher NGF level can identify 58.3% of IC/BPS cases, whereas a lower NGF level can identify 75.0% of DO cases. Conclusion: by using a cluster of urine biomarkers, DO, IC/BPS, and DV cases can be identified based on elevated levels of urine oxidative stress biomarkers 8-isoprostane, TAC, or 8-OHdG, and HSB cases with a low TAC. These urine biomarkers are useful for identifying specific LUTDs in women with frequency and urgency symptoms.

Platelet Lysate Therapy Attenuates Hypoxia Induced Apoptosis in Human Uroepithelial SV-HUC-1 Cells through Regulating the Oxidative Stress and Mitochondrial-Mediated Intrinsic Apoptotic Pathway

(1) Background: Ischemia/hypoxia plays an important role in interstitial cystitis/bladder pain syndrome (IC/BPS). Platelet-rich plasma (PRP) has been shown to relieve symptoms of IC/BPS by regulating new inflammatory processes and promoting tissue repair. However, the mechanism of action of PRP on the IC/BPS bladder remains unclear. We hypothesize that PRP might protect the urothelium during ischemia/hypoxia by decreasing apoptosis. (2) Methods: SV-HUC-1 cells were cultured under hypoxia for 3 h and treated with or without 2% PLTGold^® human platelet lysate (PL). Cell viability assays using trypan blue cell counts were examined. Molecules involved in the mitochondrial-mediated intrinsic apoptosis pathway, HIF1α, and PCNA were assessed by Western blot analysis. The detection of apoptotic cells and CM-H2DCFDA, an indicator of reactive oxygen species (ROS) in cells, was analyzed by flow cytometry. (3) Results: After 3 h of hypoxia, the viability of SV-HUC-1 cells and expression of PCNA were significantly decreased, and the expression of ROS, HIF1α, Bax, cytochrome c, caspase 3, and early apoptosis rate were significantly increased, all of which were attenuated by PL treatment. The addition of the antioxidant N-acetyl-L-cysteine (NAC) suppressed the levels of ROS induced by hypoxia, leading to inhibition of late apoptosis. (4) Conclusions: PL treatment could potentially protect the urothelium from apoptosis during ischemia/hypoxia by a mechanism that modulates the expression of HIF1α, the mitochondria-mediated intrinsic apoptotic pathway, and reduces ROS.

Stress-Induced Changes in Trophic Factor Expression in the Rodent Urinary Bladder: Possible Links With Angiogenesis

PURPOSE

Substantive evidence supports a role of chronic stress in the development, maintenance, and even enhancement of functional bladder disorders such as interstitial cystitis/bladder pain syndrome (IC/BPS). Increased urinary frequency and bladder hyperalgesia have been reported in rodents exposed to a chronic stress paradigm. Here, we utilized a water avoidance stress (WAS) model in rodents to investigate the effect of chronic stress on vascular perfusion and angiogenesis.

METHODS

Female Wistar-Kyoto rats were exposed to WAS for 10 consecutive days. Bladder neck tissues were analyzed by western immunoblot for vascular endothelial growth factor (VEGF) and nerve growth factor precursor (proNGF). Vascular perfusion was assessed by fluorescent microangiography followed by Hypoxyprobe testing to identify regions of tissue hypoxia.

RESULTS

The expression of VEGF and proNGF in the bladder neck mucosa was significantly higher in the WAS rats than in the controls. There was a trend toward increased vascular perfusion, but without a statistically significant difference from the control group. The WAS rats displayed a 1.6-fold increase in perfusion. Additionally, a greater abundance of vessels was observed in the WAS rats, most notably in the microvasculature.

CONCLUSION

These findings show that chronic psychological stress induces factors that can lead to increased microvasculature formation, especially around the bladder neck, the region that contains most nociceptive bladder afferents. These findings may indicate a link between angiogenesis and other inflammatory factors that contribute to structural changes and pain in IC/BPS.

Current Understanding of the Pathophysiology and Novel Treatments of Interstitial Cystitis/Bladder Pain Syndrome

The pathophysiology of interstitial cystitis/bladder pain syndrome (IC/BPS) is multifactorial. Identifying the clinical characteristics and cystoscopic findings of bladder-centered IC/BPS facilitates optimal treatment strategies targeting the diseased urinary bladder. Patients with Hunner’s lesion (HIC) and without Hunner’s lesion (NHIC) should be treated differently. Based on the histopathological findings, NHIC can be treated with intravesical instillation of urothelial protective agents, such as hyaluronic acid, to cover the urothelial defects. In non-responders, chronic inflammation and higher urothelial dysfunction can be treated with intravesical botulinum toxin A injection, platelet-rich plasma injection, or low-energy shock wave treatment to reduce inflammation, increase tissue regeneration, and improve the urothelial barrier. Patients with HIC should be treated with electrocauterization first; augmentation enterocystoplasty should only be used in end-stage HIC when the contracted bladder is refractory to other treatments. The antiviral agent, valacyclovir, can be used in patients with HIC, small bladder capacity, and high-grade glomerulations. In addition, behavioral modification is always recommended from the beginning of treatment. Treatment with cognitive behavioral therapy interventions in combination with bladder therapy can reduce anxiety and improve treatment outcomes. Herein, recent advances in the pathophysiology and novel treatments for IC/BPS are reviewed.

Urine Oxidative Stress Biomarkers as Novel Biomarkers in Interstitial Cystitis/Bladder Pain Syndrome

Both hypoxia and chronic suburothelial inflammation are important pathophysiological findings in patients with interstitial cystitis/bladder pain syndrome (IC/BPS). This study investigated the roles of urine oxidative stress biomarkers and inflammatory cytokines in patients with IC/BPS. Urine samples were collected from 159 IC/BPS patients and 28 controls. The targeted analytes included oxidative stress biomarkers (8-OHdG, 8-isoprostane, and total antioxidant capacity) and inflammatory cytokines (MCP-1, RANTES, CXCL10, Eotaxin, MIP-1β, and IL-8). IC/BPS patients were classified into four clinical subgroups, based on the glomerulation grade and the maximal bladder capacity under anesthesia. Patients with IC/BPS had urine oxidative stress biomarkers and inflammatory cytokines profiles that were distinct from those of the controls and among each subgroup. Both 8-OHdG and 8-isoprostane showed a high diagnostic ability to distinguish type 2 IC/BPS patients (as classified by the European Society for the Study of Interstitial Cystitis) from controls. Additionally, they both showed positive and negative correlations with the glomerulation grade and the maximal bladder capacity under anesthesia, respectively. Limitations included intra-individual variation and sex influence. Urine oxidative stress biomarkers might have a role in diagnosing IC/BPS and differentiating its clinical subtypes. In addition to inflammatory cytokines, urine oxidative stress biomarkers have the potential to be novel biomarkers in patients with IC/BPS.

Molecular Mechanisms and Key Processes in Interstitial, Hemorrhagic and Radiation Cystitis

Simple Summary

Pathologies of the bladder are called cystitis. They cause discomfort for the patient. Due to persistent pain, bleeding, urinary incontinence, and uncontrolled urination, the chronic forms cause considerable degradation to patient quality of life. Currently, there is no curative treatment for the most severe forms. This is both an economic and a societal problem. Although the different forms of cystitis have different causes, they share common mechanisms. We propose to describe in detail the key processes and the associated mechanisms involved in abacterial cystitis.

Abstract

Cystitis is a bladder disease with a high rate of prevalence in the world population. This report focuses on Interstitial Cystitis (IC), Hemorrhagic Cystitis (HC) and Chronic Radiation Cystitis. These pathologies have different etiologies, but they share common symptoms, for instance, pain, bleeding, and a contracted bladder. Overall, treatments are quite similar for abacterial cystitis, and include bladder epithelium protective or anti-inflammatory agents, alleviating pain and reducing bleeding. This review summarizes the mechanisms that the pathologies have in common, for instance, bladder dysfunction and inflammation. Conversely, some mechanisms have been described as present in only one pathology, such as neural regulation. Based on these specificities, we propose identifying a mechanism that could be common to all the above-mentioned pathologies.

Can We Use Urinary Cytokine/Chemokine Analysis in Discriminating Ulcer-Type Interstitial Cystitis/Bladder Pain Syndrome?

Purpose: Interstitial cystitis/bladder pain syndrome (IC/BPS) has ulcer (HIC) and non-ulcer subtypes. Differentiation of these two subtypes could only be based by cystoscopy. This study analyzed the urinary cytokines and chemokines among IC/BPS subtypes and controls for discriminating HIC from non-HIC and controls. Materials and Methods: A total of 309 consecutive patients with clinically diagnosed IC/BPS were enrolled. All patients received cystoscopic hydrodistention under anesthesia and urine samples were collected prior to the procedure. Enrolled patients were classified into subtypes based on the glomerulation grade, maximal bladder capacity (MBC), and presence of Hunner’s lesion. Inflammation-related cytokines and chemokines in urine samples, including interleukin-8 (IL-8), C-X-C motif chemokine ligand 10 (CXCL10), monocyte chemoattractant protein-1 (MCP-1), brain-derived neurotrophic factor (BDNF), eotaxin-1 (eotaxin), IL-6, macrophage inflammatory protein-1 beta (MIP-1β), regulated upon activation, normally T-expressed, and presumably secreted (RANTES), tumor necrosis factor-alpha (TNF-α), and prostaglandin E2 (PGE2) were assayed using commercially available microspheres with the Milliplex® Human Cytokine/Chemokine Magnetic Bead-based Panel kit. The clinical data and urine levels of analytes between IC/BPS patients and controls, and among HIC, non-HIC, and controls were analyzed. Results: Among the 10 proteins, MCP-1, eotaxin, MIP-1β, TNF-α, and PGE2 were significantly different between IC/BPS and control, while IL-8, CXCL10, BDNF, IL-6, and RANTES were significantly higher in HIC than non-HIC patients. The receiver operating characteristic curve was used to analyze each urine biomarker in the patients with IC/BPS and controls. Among the 10 urine biomarkers, MIP-1β and TNF-α had an area under curve of >0.70 to predict IC/BPS from controls, however, the predictive values of these urine biomarkers to predict HIC from non-HIC were low. Combined cut-off values of MIP-1β and TNF-α can only have a 50% sensitivity and 39.6% specificity in identifying HIC from non-HIC. Conclusion: The results of this study demonstrate that urine cytokines and chemokines may be useful to discriminate patients with HIC from controls. An elevation of urine levels of IL-8, CXCL 10, BDNF, IL-6, and RANTES in IC/BPS patients should prompt physicians to consider the diagnosis of HIC.

The Role of Urinary VEGF in Observational Studies of BPS/IC Patients: A Systematic Review

Background: Bladder pain syndrome/interstitial cystitis (BPS/IC) is a chronic pain condition, often underdiagnosed, with an important impact on patient quality of life. More recently, an association between VEGF and its receptors has been suggested in BPS/IC pathophysiology, due to their role in promoting angiogenesis and inflammation, which can enhance bladder pain. Eventually, VEGF may be used as a biomarker for the diagnosis and prognostication of BPS/IC. To further clarify this issue, this review aims to critically summarize the available information, giving rise to a solid starting point for future studies. Methods: We systematically searched PubMed and Embase, using the queries “urinary VEGF”, “urinary VEGF” AND “pain”, “urinary VEGF” AND “lower urinary tract symptoms” and “urinary VEGF” AND “LUTS” from January 2016 to February 2022. Results: A total of 1026 papers were identified from which 7 articles were included in this study, which assessed 1036 participants. Regarding VEGF levels, overactive bladder (OAB) and healthy patients were used for comparison with BPS/IC patients. VEGF concentration seems to be higher when compared to healthy patients and overactive bladder (OAB) patients. Higher levels of VEGF were associated with pain severity, while a decrease in VEGF concentration was associated with pain and symptom improvement in women. However, these findings were not constant in all studies. Conclusions: There is a trend toward a relevant association between increased VEGF levels and pain or symptom severity in BPS/IC patients. Although there are some discrepancies among the studies and the number of patients included is small, VEGF and its receptors should be considered for future studies regarding its use in BPS/IC pathophysiology, diagnosis and prognostication.

Low-Energy Shock Wave Plus Intravesical Instillation of Botulinum Toxin A for Interstitial Cystitis/Bladder Pain Syndrome: Pathophysiology and Preliminary Result of a Novel Minimally Invasive Treatment

Low-energy shock wave (LESW) therapy is known to facilitate tissue regeneration with analgesic and anti-inflammatory effects. LESW treatment has been demonstrated to be effective in treating chronic prostatitis and pelvic pain syndrome as well as overactive bladder, and it has a potential effect on interstitial cystitis/bladder pain syndrome (IC/BPS) in humans. LESW reduces pain behavior, downregulates nerve growth factor expression, and suppresses bladder overactivity by decreasing the expression of inflammatory proteins. Previous rat IC models have shown that LESW can increase urothelial permeability, facilitate intravesical delivery of botulinum toxin A (BoNT-A), and block acetic acid-induced hyperactive bladder, suggesting that LESW might be a potential therapeutic module for relieving bladder inflammatory conditions, such as bladder oversensitivity, IC/BPS, and overactive bladder. A recent clinical trial showed that LESW monotherapy was associated with a significant reduction in pain scores and IC symptoms. BoNT-A detrusor injection or liposome-encapsulated BoNT-A instillation could also inhibit inflammation and improve IC symptoms. However, BoNT-A injection requires anesthesia and certain complications might occur. Our preliminary study using LESW plus intravesical BoNT-A instillation every week demonstrated an improvement in global response assessment without any adverse events. Moreover, an immunohistochemistry study revealed the presence of cleaved SNAP25 protein in the suburothelium of IC bladder tissue, indicating that BoNT-A could penetrate across the urothelial barrier after application of LESW. These results provide evidence for the efficacy and safety of this novel IC/BPS treatment by LESW plus BoNT-A instillation, without anesthesia, and no bladder injection. This article reviews the current evidence on LESW and LESW plus intravesical therapeutic agents on bladder disorders and the pathophysiology and pharmacological mechanism of this novel, minimally invasive treatment model for IC/BPS.

Pharmacogenetic inhibition of lumbosacral sensory neurons alleviates visceral hypersensitivity in a mouse model of chronic pelvic pain

The study investigated the cellular and molecular mechanisms in the peripheral nervous system (PNS) underlying the symptoms of urologic chronic pelvic pain syndrome (UCPPS) in mice. This work also aimed to test the feasibility of reversing peripheral sensitization in vivo in alleviating UCPPS symptoms. Intravesical instillation of vascular endothelial growth factor A (VEGFA) was used to induce UCPPS-like symptoms in mice. Spontaneous voiding spot assays and manual Von Frey tests were used to evaluate the severity of lower urinary tract symptoms (LUTS) and visceral hypersensitivity in VEGFA-instilled mice. Bladder smooth muscle strip contractility recordings (BSMSC) were used to identify the potential changes in myogenic and neurogenic detrusor muscle contractility at the tissue-level. Quantitative real-time PCR (qPCR) and fluorescent immunohistochemistry were performed to compare the expression levels of VEGF receptors and nociceptors in lumbosacral dorsal root ganglia (DRG) between VEGFA-instilled mice and saline-instilled controls. To manipulate primary afferent activity, Gi-coupled Designer Receptors Exclusively Activated by Designer Drugs (Gi-DREADD) were expressed in lumbosacral DRG neurons of TRPV1-Cre-ZGreen mice via targeted adeno-associated viral vector (AAVs) injections. A small molecule agonist of Gi-DREADD, clozapine-N-oxide (CNO), was injected into the peritoneum (i. p.) in awake animals to silence TRPV1 expressing sensory neurons in vivo during physiological and behavioral recordings of bladder function. Intravesical instillation of VEGFA in the urinary bladders increased visceral mechanical sensitivity and enhanced RTX-sensitive detrusor contractility. Sex differences were identified in the baseline detrusor contractility responses and VEGF-induced visceral hypersensitivity. VEGFA instillations in the urinary bladder led to significant increases in the mRNA and protein expression of transient receptor potential cation channel subfamily A member 1 (TRPA1) in lumbosacral DRG, whereas the expression levels of transient receptor potential cation channel subfamily V member 1 (TRPV1) and VEGF receptors (VEGFR1 and VEGFR2) remained unchanged when compared to saline-instilled animals. Importantly, the VEGFA-induced visceral hypersensitivity was reversed by Gi-DREADD-mediated neuronal silencing in lumbosacral sensory neurons. Activation of bladder VEGF signaling causes sensory neural plasticity and visceral hypersensitivity in mice, confirming its role of an UCPPS biomarker as identified by the Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP) research studies. Pharmacogenetic inhibition of lumbosacral sensory neurons in vivo completely reversed VEGFA-induced pelvic hypersensitivity in mice, suggesting the strong therapeutic potential for decreasing primary afferent activity in the treatment of pain severity in UCPPS patients.

Urinary Biomarkers in Interstitial Cystitis/Bladder Pain Syndrome and Its Impact on Therapeutic Outcome

Interstitial cystitis/bladder pain syndrome (IC/BPS) is defined as a chronic bladder disorder with suprapubic pain (pelvic pain) and pressure and/or discomfort related to bladder filling accompanied by lower urinary tract symptoms, such as urinary frequency and urgency without urinary tract infection (UTI) lasting for at least 6 weeks. IC/BPS presents significant bladder pain and frequency urgency symptoms with unknown etiology, and it is without a widely accepted standard in diagnosis. Patients’ pathological features through cystoscopy and histologic features of bladder biopsy determine the presence or absence of Hunner lesions. IC/PBS is categorized into Hunner (ulcerative) type IC/BPS (HIC/BPS) or non-Hunner (nonulcerative) type IC/BPS (NHIC/BPS). The pathophysiology of IC/BPS is composed of multiple possible factors, such as chronic inflammation, autoimmune disorders, neurogenic hyperactivity, urothelial defects, abnormal angiogenesis, oxidative stress, and exogenous urine substances, which play a crucial role in the pathophysiology of IC/BPS. Abnormal expressions of several urine and serum specimens, including growth factor, methylhistamine, glycoprotein, chemokine and cytokines, might be useful as biomarkers for IC/BPS diagnosis. Further studies to identify the key molecules in IC/BPS will help to improve the efficacy of treatment and identify biomarkers of the disease. In this review, we discuss the potential medical therapy and assessment of therapeutic outcome with urinary biomarkers for IC/BPS.

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.

Improves symptoms and urinary biomarkers in refractory interstitial cystitis/bladder pain syndrome patients randomized to extracorporeal shock wave therapy versus placebo

Extracorporeal shock wave therapy (ESWT) has been shown to improve symptoms in patients with interstitial cystitis/bladder pain syndrome (IC/BPS); however, there is a lack of objective evidence. We measured change of urinary biomarker levels in 25 patients with IC/BPS received ESWT or placebo once a week for 4 weeks. Urines were collected from participants at baseline, 4 and 12 weeks post treatment. A representative 41 inflammatory growth factors, cytokines, and chemokines in urine were measured using a MILLIPLEX immunoassay kit. Symptom bother was assessed by O’Leary-Sant symptom scores (OSS), and visual analog scale (VAS) for pain. The ESWT group exhibited a significant reduction in the OSS and VAS compared to the placebo group 4 weeks post-treatment (P < 0.05), and the effects were persistent at 12 weeks. The difference in urinary markers change in ESWT versus placebo was P = 0.054 for IL4, P = 0.013 for VEGF, and P = 0.039 for IL9 at 4 weeks. The change of urine biomarker was not significant in other biomarkers or all the measured proteins at 12 weeks. The current data suggest that IL4, IL9, and VEGF mediation may be involved in its pathophysiologic mechanisms and response to LESW treatment.

Pain in Women: A Perspective Review on a Relevant Clinical Issue that Deserves Prioritization

Introduction

Gender equity and gender medicine are opportunities not to be missed, and this Expert Group Opinion Paper on pain in women aims to review the treatment of pain conditions mainly affecting women, as well as the fundamental aspects of the different clinical response to drug treatment between the genders, and what can be done for gender-specific rehabilitation.

Methods

Perspective review.

Results

Genotypic and phenotypic differences in pain between the sexes are conditioned by anatomical, physiological, neural, hormonal, psychological, social, and cultural factors, such as the response to pharmacological treatment to control pain. The examination of these factors shows that women are affected by pain diseases more frequently and severely than men and that they report pain more frequently and with a lower pain threshold than men. Some forms of pain are inherently related to gender differences, such as pain related to the genitourinary system. However, other forms of chronic pain are seen more frequently in women than men, such as migraine, rheumatological, and musculoskeletal pain, in particular fibromyalgia.

Discussion

Research is needed into the pathophysiological basis for gender differences in the generation of acute pain and maintenance of chronic pain, including the factors that put women at higher risk for developing chronic pain. In addition, different specialties need to collaborate to develop gender-related diagnostic and therapeutic guidelines, and healthcare professionals need to upskill themselves in the appropriate management of pain using existing diagnostic tools and therapeutic options.

Clinical manifestations and results of cystoscopy in women with interstitial cystitis/bladder pain syndrome

OBJECTIVE:

Interstitial cystitis/bladder pain syndrome (IC/BPS) refers to diseases that are challenging to identify, diagnose and treat. Thus, there is a need to study the clinical and cystoscopic picture of IC/BPS. The present research aims to study the clinical manifestations and results of cystoscopy with hydrodistension in women with IC/BPS.

METHODS:

One hundred twenty-six women with clinically diagnosed IC/BPS were examined – their mean age was 46.7±14.0 years. Patients were surveyed on pelvic pain and urgency/frequency patient symptom score (PUF), visual analogue scale (VAS) and urgency severity scale (USS). All patients underwent a potassium test (PST) and cystoscopy with hydrodistension. Statistical analysis was performed using SPSS software version 15.0 (SPSS Inc., Chicago, Illinois, USA).

RESULTS:

The average PUF score was 8.14±1.76 points, VAS – 5.45±0.93 points and USS – 2.63±0.91 points. A positive potassium test was detected in 91.3% of cases. The maximum average anatomical capacity of the bladder was 308.0±77.5 ml. The maximal cystometric capacity in women with mild pain was higher than among women with moderate and severe pain by 30.9% (p<0.05) and 53.0% (p<0.01), respectively. In most cases, mucosal changes were diffuse (n=57) or located in two parts of the bladder. One of the most common symptoms was the diffuse bleeding of the bladder mucosa (III degree). A statistically significant inverse correlation (r=-0.57, p<0.01) was found between the maximal cystometric bladder volume and the severity of the bladder mucosa changes. At the same time, a positive correlation was found between the severity of the bladder mucosa changes and the sum of points on the PUF questionnaire (r=+0.61, p=0.0003), the sum of points on the VAS questionnaire (r=+0.59, p=0.0008) and the USS questionnaire (r=+0.66, p=0.005).

CONCLUSION:

A relationship has been established between the clinical manifestations of IC/BPS among examined women and changes in the wall of the bladder. The data obtained from our investigation can help increase IC/BPS diagnostics and improve IC/BPS treatment results.

Evaluation of HIF-1α and VEGF-A expression in radiation-induced cystitis: A case-control study

The standard treatment for locally advanced cervical cancer (CC) is chemoradiotherapy. Once the bladder receives part of the radiation, a typical inflammatory condition that configures radiation-induced cystitis may develop. Chronic radiation-induced cystitis is commonly characterized by the bladder new submucosal vascularization, which is typically fragile and favors hematuria. The current study aims to investigate if Hypoxia-Induced Factor (HIF-1α) and its transcriptional target Vascular Endothelial Growth Factor A (VEGF-A) could be a primary pathway leading to increased submucosal vascularization. HIF-1α and VEGF-A mRNA levels in bladder core biopsies from CC patients treated with radiotherapy versus untreated (non-irradiated) patients were analyzed using a droplet digital polymerase chain reaction technology. Gene expression results showed that HIF-1α and VEGF-A had no significant differences between bladder samples from patients previously irradiated and untreated patient samples. However, a direct relationship between the degree of late morbidity and the expression of HIF-1α and VEGF-A has been demonstrated. Despite the lack of statistical significance precludes a definitive conclusion, the data presented herein suggests that further studies investigating the role of HIF-1α in bladder neovascularization in radiation-induced cystitis are highly recommended.

New Frontiers or the Treatment of Interstitial Cystitis/Bladder Pain Syndrome - Focused on Stem Cells, Platelet-Rich Plasma, and Low-Energy Shock Wave

Interstitial cystitis/bladder pain syndrome (IC/BPS), which is characterized by bladder pain and irritative voiding symptoms, is a frustrating disease without effective treatment. The cause is still largely not understood, although urothelium ischemia/hypoxia, apoptosis, denudation, and infiltration of inflammatory cells are common histopathological findings. The current uncertainty regarding the etiology and pathology of IC/BPS has a negative impact on its timely and successful treatment; therefore, the development of new treatment modalities is urgently needed. Herein, we present advances in our knowledge on this topic and review the potential application of regenerative medicine for the treatment of IC/BPS. This article provides information on the basic characteristics and clinical evidence of stem cells, platelet-rich plasma (PRP), and low-energy shock waves (LESWs) based on a literature review with a search strategy for articles related to IC/BPS, stem cells, PRP, and LESW published in MEDLINE and PubMed. Stem cells, PRP, and LESW, which modulate inflammatory processes and promote tissue repair, have been proven to improve bladder regeneration, relieve bladder pain, inhibit bladder inflammation, and increase bladder capacity in some preclinical studies. However, clinical studies are still in their infancy. Based on the mechanisms of action of stem cells, PRP, and LESW documented in many preclinical studies, the potential applications of regenerative medicine for the treatment of IC/BPS is an emerging frontier of interest. However, solid evidence from clinical studies remains to be obtained.

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

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

Clinical and morphological effects of hyperbaric oxygen therapy in patients with interstitial cystitis associated with fibromyalgia

Background

Interstitial Cystitis (IC) is a debilitating disorder of the bladder, with a multifactorial and poorly understood origin dealing with microcirculation repeated damages. Also Fibromyalgia (FM) is a persistent disorder whose etiology is not completely explained, and its theorized alteration of pain processing can compromise the quality of life. Both these conditions have a high incidence of conventional therapeutic failure, but recent literature suggests a significant beneficial response to Hyperbaric Oxygen Therapy (HBOT). With this study, this study we evaluated the effects of HBOT on quality of life, symptoms, urodynamic parameters, and cystoscopic examination of patients suffering from both IC and FM.

Methods

We structured an observational clinical trial design with repeated measures (questionnaires, urodynamic test, and cystoscopy) conducted before and 6 months after a therapeutic protocol with hyperbaric oxygen for the treatment of patients suffering from both IC and FM. Patients were exposed to breathing 100% oxygen at 2 atm absolute (ATA) in a multiplace pressure chamber for 90 min using an oro-nasal mask. Patients undertook a cycle of 20 sessions for 5 days per week, and a second cycle of 20 sessions after 1 week of suspension.

Results

Twelve patients completed the protocol. Changes after HBOT were not significant, except for hydrodistension tolerance (mean pre-treatment: 409.2 ml; mean post-treatment: 489.2 ml; p < 0.05). A regression of petechiae and Hunner’s ulcers was also noted 6 months after the completion of HBOT.

Conclusions

Our study showed no improvement of symptoms, quality of life, and urodynamic parameters, except for hydrodistension, and a slight improvement in cystoscopic pattern. However, to date, we could not demonstrate the significance of overall results to justify the use of HBOT alone in patients with IC and FM. This observation suggests that additional studies are needed to better understand if HBOT could treat this subset of patients.

Trial registration

NCT03693001; October 2, 2018. Retrospectively registered.

Functional effects of blocking VEGF/VEGFR2 signaling in the rat urinary bladder in acute and chronic CYP-induced cystitis

High expression of VEGF is associated with immature angiogenesis within the urinary bladder wall and bladder afferent nerve sensitization, leading to visceral hyperalgesia and pelvic pain. Research suggests a shift in VEGF alternative splice variant (VEGF-A_xxxa and VEGF-A_xxxb) expression with several pathologies (e.g., neuropathic pain and inflammation) as well as differing effects on pain. Translational studies have also demonstrated increased total VEGF expression in the bladders of women with interstitial cystitis/bladder pain syndrome. In the present study, we quantified VEGF alternative splice variant expression in lower urinary tract tissues under control conditions and with cyclophosphamide (CYP)-induced cystitis. Using conscious cystometry and intravesical instillation of a potent and selective VEGF receptor 2 (VEGFR2) tyrosine kinase inhibitor (Ki-8751, 1 mg/kg) in Wistar rats (male and female) with acute and chronic CYP-induced cystitis and control (no CYP) rats, we further determined the functional effects of VEGFR2 blockade on bladder function. With VEGFR2 blockade, bladder capacity increased (P ≤ 0.01) in male and female control rats as well as in male and female rats with acute (P ≤ 0.05) or chronic (P ≤ 0.01 or P ≤ 0.05, respectively) CYP-induced cystitis. Void volume also increased in female control rats (P ≤ 0.01) and female rats with acute (P ≤ 0.05) or chronic (P ≤ 0.05) CYP-induced cystitis as well as in male control rats (P ≤ 0.05) and male rats with chronic CYP-induced cystitis (P ≤ 0.01). These data suggest that VEGF may be a biomarker for interstitial cystitis/bladder pain syndrome and that targeting VEGF/VEGFR2 signaling may be an effective treatment.

Identification of novel non-invasive biomarkers of urinary chronic pelvic pain syndrome: findings from the Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP) Research Network

OBJECTIVE

To examine a series of candidate markers for urological chronic pelvic pain syndrome (UCPPS), selected based on their proposed involvement in underlying biological processes so as to provide new insights into pathophysiology and suggest targets for expanded clinical and mechanistic studies.

METHODS

Baseline urine samples from Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP) Research Network study participants with UCPPS (n = 259), positive controls (PCs; chronic pain without pelvic pain, n = 107) and healthy controls (HCs, n = 125) were analysed for the presence of proteins that are suggested in the literature to be associated with UCPPS. Matrix metalloproteinase (MMP)-2, MMP-9, MMP-9/neutrophil gelatinase-associated lipocalin (NGAL) complex (also known as Lipocalin 2), vascular endothelial growth factor (VEGF), VEGF receptor 1 (VEGF-R1) and NGAL were assayed and quantitated using mono-specific enzyme-linked immunosorbent assays for each protein. Log-transformed concentration (pg/mL or ng/mL) and concentration normalized to total protein (pg/μg) values were compared among the UCPPS, PC and HC groups within sex using the Student's t-test, with P values adjusted for multiple comparisons. Multivariable logistic regression and receiver-operating characteristic curves assessed the utility of the biomarkers in distinguishing participants with UCPPS and control participants. Associations of protein with symptom severity were assessed by linear regression.

RESULTS

Significantly higher normalized concentrations (pg/μg) of VEGF, VEGF-R1 and MMP-9 in men and VEGF concentration (pg/mL) in women were associated with UCPPS vs HC. These proteins provided only marginal discrimination between UCPPS participants and HCs. In men with UCCPS, pain severity was significantly positively associated with concentrations of MMP-9 and MMP-9/NGAL complex, and urinary severity was significantly positively associated with MMP-9, MMP-9/NGAL complex and VEGF-R1. In women with UCPPS, pain and urinary symptom severity were associated with increased normalized concentrations of MMP-9/NGAL complex, while pain severity alone was associated with increased normalized concentrations of VEGF, and urinary severity alone was associated with increased normalized concentrations of MMP-2. Pain severity in women with UCPPS was significantly positively associated with concentrations of all biomarkers except NGAL, and urinary severity with all concentrations except VEGF-R1.

CONCLUSION

Altered levels of MMP-9, MMP-9/NGAL complex and VEGF-R1 in men, and all biomarkers in women, were associated with clinical symptoms of UCPPS. None of the evaluated candidate markers usefully discriminated UCPPS patients from controls. Elevated VEGF, MMP-9 and VEGF-R1 levels in men and VEGF levels in women may provide potential new insights into the pathophysiology of UCPPS.

Anti-vascular endothelial growth factor treatment decreases bladder pain in cyclophosphamide cystitis: a Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP) Research Network animal model study

OBJECTIVE

To investigate whether treatment with anti-vascular endothelial growth factor (VEGF)-neutralizing antibodies can reduce pain and voiding dysfunction in the cyclophosphamide (CYP) cystitis model of bladder pain in mice.

MATERIALS AND METHODS

Adult female mice received anti-VEGF-neutralizing antibodies (10 mg/kg i.p. B20-4.1.1 VEGF mAb) or saline (control) pre-treatment, followed by CYP (150 mg/kg i.p.) to induce acute cystitis. Pelvic nociceptive responses were assessed by applying von Frey filaments to the pelvic area. Spontaneous micturition was assessed using the void spot assay.

RESULTS

Systemic anti-VEGF-neutralizing antibody treatment significantly reduced the pelvic nociceptive response to CYP cystitis compared with control (saline). In the anti-VEGF pre-treatment group, there was a significant increase in pelvic hypersensitivity, measured by the area under the curve (AUC) using von Frey filaments at 5 h post-CYP administration (P = 0.004); however, by 48 h and 96 h post-CYP administration, pelvic hypersensitivity had reduced by 54% and 47%, respectively, compared with the 5 h post-CYP administration time point, and were no longer significantly different from baseline (P = 0.22 and 0.17, respectively). There was no difference in urinary frequency and mean voided volume between the two pre-treatment groups.

CONCLUSION

Systemic blockade of VEGF signalling with anti-VEGF-neutralizing antibodies was effective in reducing pelvic/bladder pain in the CYP cystitis model of bladder pain. Our data support the further investigation of the use of anti-VEGF antibodies to manage bladder pain or visceral pain.

Pathomechanism of Interstitial Cystitis/Bladder Pain Syndrome and Mapping the Heterogeneity of Disease

Interstitial cystitis/bladder pain syndrome (IC/BPS) is a heterogeneous syndrome which is usually characterized by urinary frequency, nocturia, and bladder pain. Several pathomechanisms have been proposed, including uroepithelial dysfunction, mast cell activation, neurogenic inflammation, autoimmunity, and occult urinary tract infections. It is possible that an inflammatory process alters regulation of urothelial homeostasis and results in dysfunction of the bladder epithelium. Different phenotypes of IC/BPS have been explored including Hunner and non-Hunner type IC, hypersensitive bladder, and bladder pain both with and without functional somatic syndrome. Different gene expressions have also been found in different IC phenotypes. Abnormal expressions of uroplakin, chondroitin sulfate and adhesive protein E-cadherin, tight junction protein zonula occludens-1 in IC/BPS bladder suggest abnormal epithelial differentiation in this bladder disease. Analysis of inflammatory proteins, or cytokines in the urine or serum provides another diagnostic foundation forIC/BPS subtypes. The involvement of IC/BPS in systemic functional somatic syndrome and other pelvic organ diseases might also subdivide subtypes of IC/BPS. Chronic inflammation, increased urothelial apoptosis, and abnormal urothelial function are closely associated in IC bladders. This article reviews recent research on the pathomechanisms of IC, which might help us in mapping the heterogeneity of the disease.

Clinical guidelines for interstitial cystitis and hypersensitive bladder updated in 2015

Clinical guidelines for interstitial cystitis and hypersensitive bladder have been updated as of 2015. The guidelines define interstitial cystitis by the presence of hypersensitive bladder symptoms (discomfort, pressure or pain in the bladder usually associated with urinary frequency and nocturia) and bladder pathology, after excluding other diseases explaining symptoms. Interstitial cystitis is further classified by bladder pathology; either Hunner type interstitial cystitis with Hunner lesions or non-Hunner type interstitial cystitis with mucosal bleeding after distension in the absence of Hunner lesions. Hypersensitive bladder refers to a condition, where hypersensitive bladder symptoms are present, but bladder pathology or other explainable diseases are unproven. Interstitial cystitis and hypersensitive bladder severely affect patients' quality of life as a result of disabling symptoms and/or comorbidities. Reported prevalence suggestive of these disorders varies greatly from 0.01% to >6%. Pathophysiology would be an interaction of multiple factors including urothelial dysfunction, inflammation, neural hyperactivity, exogenous substances and extrabladder disorders. Definite diagnosis of interstitial cystitis and hypersensitive bladder requires cystoscopy with or without hydrodistension. Most of the therapeutic options lack a high level of evidence, leaving a few as recommended therapeutic options.

Revisiting the Role of Potassium Sensitivity Testing and Cystoscopic Hydrodistention for the Diagnosis of Interstitial Cystitis

OBJECTIVES

To revisit the diagnostic roles of cystoscopic hydrodistention and the potassium sensitivity test (PST) for the diagnosis of interstitial cystitis (IC).

METHODS

We prospectively enrolled 214 patients clinically diagnosed with IC, 125 non-IC patients who underwent video urodynamic studies and PST, and another 144 non-IC patients who underwent cystoscopic hydrodistention before transurethral surgery. The sensitivity, specificity, and positive and negative predictive values were calculated for the PST and glomerulations after cystoscopic hydrodistention.

RESULTS

After cystoscopic hydrodistention, glomerulations developed in 211/214 (98.6%) IC patients and 61/144 (42.4%) of the non-IC patients including patients with stones (45/67, 67%), hematuria (2/5, 40%), and stress urinary incontinence (SUI) (6/17, 35%). When positive glomerulation was defined as grade 2 or more, the sensitivity was 61.7%. The PST was positive in 183/214 (85.5%) IC patients and 7/17 (41%) with hypersensitive bladder, 7/32 (22%) with detrusor overactivity, 5/27 (18%) with SUI, 2/21 (10%) with lower urinary tract symptoms, and 2/25 (8%) with bladder outlet obstruction. The PST had a sensitivity of 85.5% and a specificity of 81.6% for diagnosis of IC. IC patients with a positive PST had a significantly smaller urgency sensation capacity, smaller voided volume, and greater bladder pain score.

CONCLUSIONS

Both the PST and glomerulations after hydrodistention are sensitive indicators of IC, but the specificity of glomerulations in the diagnosis of IC is lower than that of the PST. A positive PST is associated with a more hypersensitive bladder and bladder pain, but not the grade of glomerulations in IC patients. Neither test provided 100% diagnostic accuracy for IC, we might select patients into different subgroups based on different PST and hydrodistention results, not for making a diagnosis of IC but for guidance of different treatments.

Impaired Na(+)/K(+)-ATPase Function in Patients with Interstitial Cystitis/Painful Bladder Syndrome

Na(+)/K(+)-ATPase (NKA) is abundantly expressed in the basolateral membrane of epithelial cells, which is necessary for tight junction formation. The tight junction is an urothelial barrier between urine and the underlying bladder. Impairment of tight junctions allows migration of urinary solutes in patients with interstitial cystitis/painful bladder syndrome (IC/PBS). We evaluated NKA expression and activity in bladder samples from patients with IC/PBS. The study group consisted of 85 patients with IC/PBS, and the control group consisted of 20 volunteers. Bladder biopsies were taken from both groups. We determined the expression and distribution of NKA using NKA activity assays, immunoblotting, immunohistochemical staining, and immunofluorescent staining. The protein levels and activity of NKA in the study group were significantly lower than the control group (1.08 ± 0.06 vs. 2.39 ± 0.29 and 0.60 ± 0.04 vs. 1.81 ± 0.18 µmol ADP/mg protein/hour, respectively; P < 0.05). Additionally, immunofluorescent staining for detection of CK7, a marker of the bladder urothelium, predominantly colocalized with NKA in patients in the study group. Our results demonstrated the expression and activity of NKA were decreased in bladder biopsies of patients with IC/PBS. These findings suggest that NKA function is impaired in the bladders from patients with IC/PBS.

Potential urine and serum biomarkers for patients with bladder pain syndrome/interstitial cystitis

There is a lack of consensus on the pathophysiology of bladder pain syndrome/interstitial cystitis. The chronic pain symptoms of bladder pain syndrome/interstitial cystitis refractory to local treatment could be a result of central nervous system sensitization and persisting abnormalities in the bladder wall, which activate the afferent sensory system. Evidence also shows that bladder pain syndrome/interstitial cystitis is a heterogeneous syndrome and that the two subtypes, the ulcerative (classic) and non-ulcerative types, represent different disease entities. There is a need for non-invasive markers for the differential diagnoses of the subtypes of bladder pain syndrome/interstitial cystitis, and between bladder pain syndrome/interstitial cystitis and bladder sensory disorders, such as hypersensitive bladder syndrome or overactive bladder. Bladder pain syndrome/interstitial cystitis, but not overactive bladder, involves an aberrant differentiation program in the bladder urothelium that leads to altered synthesis of several proteoglycans, cell adhesion and tight junction proteins, and bacterial defense molecules. These findings have led to the rationale for identifying urinary biomarkers to detect bladder pain syndrome/interstitial cystitis in patients with frequency urgency syndrome. Recently, the markers that have been the focus of the most research are antiproliferative factor, epidermal growth factor, heparin-binding epidermal growth factor, glycosaminoglycans and bladder nitric oxide. In addition, inflammatory proteins in the urine and serum play important roles in the pathogenesis of bladder pain syndrome/interstitial cystitis. The urinary proteome is an easily accessible source of biomarkers for differentiation between inflammatory bladder disorders. Analysis of multiple urinary proteins and serum cytokines could provide a diagnostic basis for bladder pain syndrome/interstitial cystitis, and could be a tool for the differential diagnosis of bladder pain syndrome/interstitial cystitis and other sensory bladder disorders.

Reduced expression of prostacyclin synthase and nitric oxide synthase in subcutaneous arteries of type 2 diabetic patients

Diabetic endothelial dysfunction is characterized by impaired endothelium-dependent relaxation. In this study, we measured the expression of endothelial nitric oxide synthase (eNOS), cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2), prostacyclin synthase (PGIS), and prostacyclin receptor (IP) in subcutaneous arteries of type-2 diabetic and non-diabetic patients. Subcutaneous arteries were dissected from tissues from seven diabetics (4 males and 3 females) and seven non-diabetics (5 males and 2 females) aged between 18 to 65 years, who underwent lower limb surgical procedures. Diabetics had higher fasting blood glucose compared to non-diabetics, but there were no differences in blood pressure, body mass index and age. Patients were excluded if they had uncontrolled hypertension, previous myocardial infarction, coronary heart disease, renal or hepatic failure and tumor. The relative expression levels of eNOS, COX-1, COX-2, PGIS and IP receptor were determined by Western blotting analysis, normalized with the β-actin level. Increased expression of COX-2 was observed in subcutaneous arteries of diabetics compared to non-diabetics, whereas the expression levels of eNOS and PGIS were significantly lower in diabetics. There were no significant differences in expression levels of COX-1 and IP receptor between the two groups. Immunohistochemical study of subcutaneous arteries showed that the intensities of eNOS and PGIS staining were lower in diabetics, with higher COX-2 staining. In conclusion, type-2 diabetes is associated with higher COX-2 expression, but lower eNOS and PGIS expression in subcutaneous arteries. These alterations may lead to impaired endothelium-dependent vasodilatation, and thus these proteins may be potential targets for protection against the microvascular complications of diabetes.

Evidence for bladder urothelial pathophysiology in functional bladder disorders

Understanding of the role of urothelium in regulating bladder function is continuing to evolve. While the urothelium is thought to function primarily as a barrier for preventing injurious substances and microorganisms from gaining access to bladder stroma and upper urinary tract, studies indicate it may also function in cell signaling events relating to voiding function. This review highlights urothelial abnormalities in bladder pain syndrome/interstitial cystitis (BPS/IC), feline interstitial cystitis (FIC), and nonneurogenic idiopathic overactive bladder (OAB). These bladder conditions are typified by lower urinary tract symptoms including urinary frequency, urgency, urgency incontinence, nocturia, and bladder discomfort or pain. Urothelial tissues and cells from affected clinical subjects and asymptomatic controls have been compared for expression of proteins and mRNA. Animal models have also been used to probe urothelial responses to injuries of the urothelium, urethra, or central nervous system, and transgenic techniques are being used to test specific urothelial abnormalities on bladder function. BPS/IC, FIC, and OAB appear to share some common pathophysiology including increased purinergic, TRPV1, and muscarinic signaling, increased urothelial permeability, and aberrant urothelial differentiation. One challenge is to determine which of several abnormally regulated signaling pathways is most important for mediating bladder dysfunction in these syndromes, with a goal of treating these conditions by targeting specific pathophysiology.

Activation of extrinsic apoptotic pathway from bladder biopsy in patients with interstitial cystitis/painful bladder syndrome

OBJECTIVE

To investigate the intrinsic or extrinsic pathway of apoptosis from bladder biopsy that was performed in interstitial cystitis/painful bladder syndrome (IC/PBS). Although previous studies have reported observations of the dysfunction, denudation, and thinning of the bladder urothelium in patients associated with an increase of cell apoptosis, the molecular mechanism is unclear.

METHODS

The study group consisted of 32 patients with IC/PBS, and the control group consisted of 12 volunteers without any symptoms of IC. Bladder biopsies were obtained from both the groups. The expression of apoptosis-associated proteins was observed by detecting the Bcl-2/Bax ratio and the levels of cleaved caspase-9, Fas, cleaved caspase-8, and cleaved caspase-3 to differentiate intrinsic or extrinsic pathway. The data were analyzed using Mann-Whitney U test.

RESULTS

Increased levels of cleaved caspase-3 were found in the IC/PBS group relative to the control group (P <.05). The levels of the extrinsic apoptotic pathway proteins, Fas and cleaved caspase-8, were also increased in the study group compared with the control group (P <.05). There was no significant difference in the levels of the intrinsic apoptotic pathway proteins, including cleaved caspase-9 and the Bcl-2/Bax ratio, between the control and study groups.

CONCLUSION

Our findings demonstrate the activation of extrinsic apoptotic pathway from bladder biopsy in patients with IC/PBS. This study might help us to clarify the molecular changes and lead to a better understanding of this bladder disease.

[The care situation of patients with interstitial cystitis in Germany: results of a survey of 270 patients]

BACKGROUND

Using a comprehensive questionnaire the care situation of 270 patients with interstitial cystitis (IC) and bladder pain syndrome in Germany was recorded. Despite comprehensive literature on IC (62,000 citations in PubMed) almost nothing is known of the everyday care and quality of patient care in Germany.

RESULTS

In total 94% of the patients were women and 6% men, the average age of women was 53.5 years and that of men 67 years and 47.77% of the patients felt that they were well or very well informed about the disease whereby the internet was the source of information in many cases. The exchange of information among patients will increase further through social networks. The diagnosis of IC was made most frequently (62.22%) by biopsy and histological examination followed by urodynamics, potassium test, hydrodistension and cystoscopy. The average duration of the diagnosis was 9 years, 46.67% of the patients consulted a doctor more than 20 times before the diagnosis was made and 51.84% had to pass water more than 14 times per day. Frequency, nocturia and pain were the leading symptoms and 25% of the patients complained of urge incontinence. Among oral medications, analgesics were taken most frequently (61.7%) followed by pentosan polysulphate, antidepressants, antiepileptic drugs, antispasmodics and remedies for urinary urgency. In the self-assessment of the success of treatment with oral medications (helped very well and well), pentosan polysulphate, analgesics, antidepressants and antiepileptic drugs were considered to be the best. Medications that restore the glucosamine lining of the bladder were used predominantly for instillation into the bladder included hyaluronic acid, chondroitin sulphate and a combination of both and pentosan polysulphate. In the self-assessment of the success of treatment with instillation therapy (helped very well or well) the order was: chondroitin sulphate (62.69%), hyaluronic acid (55.77%), a combination of both (53.66%) and pentosan polysulphate (46.30%). The electromotive drug administration (EMDA) procedure with the use of direct current to introduce medications into the bladder wall was mentioned surprisingly often, namely, in 119 patients. In the self-assessment success (helped very well or well) was considered the best for intravesical procedures with 61.34%.

CONCLUSIONS

Compared with all drug procedures instillation of medications into the bladder was mentioned 368 times and was assessed by the patients as having helped very well and noticeably by 53.53%, followed by special invasive procedures at 50.56%/271 mentions, alternative therapies at 41.11%/287 mentions and oral medication at 39.75%/1,024 mentions. Hyaluronic acid and chondroitin sulphate products, the combination of both and pentosan polysulphate (oral and intravesical) are not reimbursed by the statutory health insurance. Over 40% of patients treated with these therefore discontinued the treatment for reasons of cost.