Subtypes of bladder mast cells in interstitial cystitis

Lower Urinary Tract Symptoms (LUTS) as a New Clinical Presentation of Histamine Intolerance: A Prevalence Study of Genetic Diamine Oxidase Deficiency

Lower urinary tract symptoms (LUTS) are highly prevalent, and their treatment is mainly focused on the control of symptoms. Histamine intolerance (HIT) has been related to a variety of systemic symptoms. DAO deficiency has been identified as a significant factor contributing to histamine intolerance (HIT). Preclinical evidence indicates the involvement of histamine in the lower urinary tract. This study aimed to assess the prevalence of diamine oxidase deficiency (DAO) in a prospective cohort of 100 patients with at least moderate LUTS. A genetic study of four single nucleotide polymorphisms (SNPs) (c.-691G>T, c.47C>T, c.995C>T, and c.1990C>G) was performed. HIT was found in 85.9% of patients. The prevalence of at least one minor allele in the SNPs analyzed was 88%, without gender differences. Storage symptoms were more intense in the presence of HIT as well as asthenia and neurological and musculoskeletal symptoms. The presence of minor alleles of the AOC1 gene was associated with a higher intensity of symptoms. Minor alleles from c.-691G>T and c.47C>T SNPs were also associated with a greater severity of obstructive symptoms. Thirty-one percent of patients presented the four SNPS with at least one associated minor allele. The relationship between HIT and LUTS in a mixed population of men and women found in this study supports further investigations to define the pathophysiology of histamine in LUTS.

[S2K guideline on the diagnosis and treatment of interstitial cystitis (IC/BPS) : Discussion of the current guideline using a case study]

IC/BPS is a chronic progressive disorder that is often difficult and unsatisfactory for the person affected and the treating therapist. Treatment should therefore be comprehensive, interdisciplinary, multimodal and take into account the biopsychosocial model. The guideline forms a thread through the diverse diagnostic and therapeutic options and provides extensive background information on the definition, epidemiology and aetiopathogenesis of this rare disease. However, practice and theory/guideline are different. Adaptation to the individual case is therefore necessary and explicitly desired. The guideline should therefore serve as a source of ideas for colleagues to compile their own standards suitable for their practice. On the one hand, therapy approaches that have been tried and tested in everyday clinical practice are passed on. On the other hand, the frequent lack of evidence should also be viewed critically. Further studies, if possible multi-centre, specifically designed for different aspects of IC/BPS would be desirable. Close networking between therapists in private practice and special centres is essential for the best possible treatment of people with IC/BPS. The guideline is intended to show the limits of what can be done in practices and outpatient clinics and to provide guidance on when patients should be referred to a "Centre for Interstitial Cystitis and Pelvic Pain". Overall, the guideline has improved the presence of this rare disease among colleagues. A comprehensive supplement, update and further substantiation with the state of current research is thus desirable.

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.

Biomarkers in Interstitial Cystitis/Bladder Pain Syndrome with and without Hunner Lesion: A Review and Future Perspectives

Interstitial cystitis/bladder pain syndrome (IC/BPS) is a debilitating urinary bladder condition that presents with a wide variety of clinical phenotypes. It is commonly characterized by persistent pelvic pain and lower urinary tract symptoms, such as urinary frequency and urgency. Current clinicopathological and genomic evidence has indicated that IC/BPS with Hunner lesions is a clinically relevant distinct subtype with proven bladder pathology of subepithelial chronic inflammatory changes that are characterized by enhanced local immune responses and epithelial denudation. However, other forms of IC/BPS lacking Hunner lesions are a symptom syndrome complex of non-inflammatory conditions with little evidence of bladder etiology, characterized by aberrant neural activity in neurotransmission systems which leads to central nervous sensitization with potential involvement of urothelial malfunction, or clinical presentation of somatic and/or psychological symptoms beyond the bladder. Given such distinct potential pathophysiology between IC/BPS subtypes, disease biomarkers of IC/BPS should be provided separately for subtypes with and without Hunner lesions. Tailored approaches that target characteristic immunological inflammatory processes and epithelial denudation for IC/BPS with Hunner lesions, or the sensitized/altered nervous system, urothelial malfunction, association with other functional somatic syndromes, and psychosocial problems for IC/BPS without Hunner lesions, are essential to identify optimal and reliable disease-specific IC/BPS biomarkers.

P2X7 Receptor Blockade Protects Against Acrolein-Induced Bladder Damage: A Potential New Therapeutic Approach for the Treatment of Bladder Inflammatory Diseases

Inflammatory conditions of the urinary bladder have been shown to be associated with urothelial damage and loss of function. The purinergic P2X7 receptor has been implicated in several inflammatory conditions. The aim of this study was to investigate the role of the P2X7 receptor in acrolein-induced inflammatory damage using the porcine urinary bladder. For this purpose, an ex-vivo model of porcine urothelial damage induced by direct instillation of acrolein into the whole bladder lumen was used. To determine the role of the P2X7 receptor, the bladders were pre-incubated with a selective P2X7 receptor antagonist, A804598 (10 μM), for 1 h. The effects of the acrolein-induced urothelial damage on the bladder’s function were assessed by examining the bladder wall contractile response, structure changes, apoptosis, and oxidative stress in the bladder tissues. The acrolein treatment led to significant damage to the urothelium histology, tight junction expression, and contractile responses. Acrolein also induced apoptosis in the mucosa layer. All these acrolein-induced responses were attenuated by pre-treatment with the P2X7 receptor antagonist A804598. Acrolein also significantly induced DNA oxidation in the submucosal layer; however, the P2X7 receptor antagonism did not show any protective effect towards the acrolein-induced oxidative stress. These findings suggested that the P2X7 receptor is involved in the acrolein-induced damage to the urothelium; therefore, the P2X7 receptor antagonists may be a new therapeutic option for the treatment of bladder inflammation.

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.

Alterations in histamine responses between juvenile and adult urinary bladder urothelium, lamina propria and detrusor tissues

Inflammatory mediators may have a role in various lower urinary tract disorders. Histamine is known to induce significant increases in both the tension and frequency of spontaneous phasic contractions in both urothelium with lamina propria (U&LP) and detrusor muscle via the activation of H1 receptor in juvenile animal models. However, it is unclear whether age affects these contractile responses to histamine. This study assessed the histamine receptor subtypes mediating contraction in juvenile and adult porcine bladders and compared the urothelium with lamina propria and detrusor responses to histamine. Isolated tissue bath studies were conducted using strips of porcine U&LP and detrusor obtained from juvenile (6 months) and adult (3 years) animals exposed to histamine receptor agonists and antagonists. Treatment with histamine (100 µM) in U&LP of juvenile animals caused increases in baseline tension by 47.84 ± 6.52 mN/g (p < 0.001, n = 51) and by 50.76 ± 4.10 mN/g (p < 0.001, n = 55) in adult animals. Furthermore, the frequency of spontaneous phasic contractions was significantly enhanced in response to histamine in U&LP of both juvenile and adult tissues (p < 0.001 for both age groups). Treatment with an H2 agonist in U&LP of juvenile animals decreased baseline tension by 13.97 ± 3.45 mN/g (n = 12, p < 0.05), but had no effect in adult animals. Inhibition of H1 receptors resulted in significantly reduced contractile responses of U&LP and detrusor to histamine in both juvenile and adult animals (p < 0.05). Treatment with an H2 receptor antagonist significantly enhanced contractions in juvenile preparations (n = 10, p < 0.05) but had no effect in adult preparations (n = 8). In detrusor, treatment with histamine (100 µM) in juvenile tissues showed a significantly higher increase in baseline tension of 19.10 ± 4.92 mN/g (n = 51) when compared to adult tissues exhibiting increases of 8.21 ± 0.89 mN/g (n = 56, p < 0.05). The increases in the baseline tension were significantly inhibited by the presence of H1 receptor antagonists in both juvenile and adult detrusor preparations. Treatment with either the H2 receptor antagonist or agonist in detrusor had no effect on both juvenile and adult tissues. Therefore, the histamine receptor system may play an essential role in the maintenance of bladder function or in bladder dysfunction observed in some lower urinary tract disorders.

Histamine induces peripheral and central hypersensitivity to bladder distension via the histamine H1 receptor and TRPV1

Interstitial cystitis/bladder pain syndrome (IC/BPS) is a common chronic pelvic disorder with sensory symptoms of urinary urgency, frequency, and pain, indicating a key role for hypersensitivity of bladder-innervating sensory neurons. The inflammatory mast cell mediator histamine has long been implicated in IC/BPS, yet the direct interactions between histamine and bladder afferents remain unclear. In the present study, we show, using a mouse ex vivo bladder afferent preparation, that intravesical histamine enhanced the mechanosensitivity of subpopulations of afferents to bladder distension. Histamine also recruited “silent afferents” that were previously unresponsive to bladder distension. Furthermore, in vivo intravesical histamine enhanced activation of dorsal horn neurons within the lumbosacral spinal cord, indicating increased afferent signaling in the central nervous system. Quantitative RT-PCR revealed significant expression of histamine receptor subtypes ( Hrh1– Hrh3) in mouse lumbosacral dorsal root ganglia (DRG), bladder detrusor smooth muscle, mucosa, and isolated urothelial cells. In DRG, Hrh1 was the most abundantly expressed. Acute histamine exposure evoked Ca2+ influx in select populations of DRG neurons but did not elicit calcium transients in isolated primary urothelial cells. Histamine-induced mechanical hypersensitivity ex vivo was abolished in the presence of the histamine H1 receptor antagonist pyrilamine and was not present in preparations from mice lacking transient receptor potential vanilloid 1 (TRPV1). Together, these results indicate that histamine enhances the sensitivity of bladder afferents to distension via interactions with histamine H1 receptor and TRPV1. This hypersensitivity translates to increased sensory input and activation in the spinal cord, which may underlie the symptoms of bladder hypersensitivity and pain experienced in IC/BPS.

Purinergic P2X7 receptors as therapeutic targets in interstitial cystitis/bladder pain syndrome; key role of ATP signaling in inflammation

Interstitial cystitis/bladder pain syndrome (IC/BPS) is a chronic lower urinary tract condition. Patients with IC/BPS suffer from debilitating pain and urinary urgency. The underlying etiology of IC/BPS is unknown and as such current treatments are mostly symptomatic with no real cure. Many theories have been proposed to describe the etiology of IC/BPS, but this review focuses on the role of inflammation. In IC/BPS patients, the permeability of the urothelium barrier is compromised and inflammatory cells infiltrate the bladder wall. There are increased levels of many inflammatory mediators in patients with IC/BPS and symptoms such as pain and urgency that have been associated with the degree of inflammation. Recent evidence has highlighted the role of purinergic receptors, specifically the P2X7 receptor, in the process of inflammation. The results from studies in animals including cyclophosphamide-induced hemorrhagic cystitis strongly support the role of P2X7 receptors in inflammation. Furthermore, the deletion of the P2X7 receptor or antagonism of this receptor significantly reduces inflammatory mediator release from the bladder and improves symptoms. Research results from IC/BPS patients and animal models of IC/BPS strongly support the crucial role of inflammation in the pathophysiology of this painful disease. Purinergic signaling and purinergic receptors, especially the P2X7 receptor, play an undisputed role in inflammation. Purinergic receptor antagonists show positive results in treating different symptoms of IC/BPS.

Histamine modulation of urinary bladder urothelium, lamina propria and detrusor contractile activity via H1 and H2 receptors

The mechanisms underlying bladder contractile disorders such as overactive bladder are not fully understood, and there is limited understanding of the receptor systems modulating spontaneous bladder contractions. We investigated the potential for histamine to have a role in mediating contractility of the urothelium with lamina propria (U&LP) or detrusor via the H1-H4 histamine receptor subtypes. Isolated strips of porcine U&LP or detrusor smooth muscle were mounted in gassed Krebs-bicarbonate solution and responses to histamine obtained in the absence and presence of selective receptor antagonists. The presence of histamine increases the frequency of U&LP spontaneous phasic contractions and baseline tensions. In response to histamine, H1-antagonists pyrilamine, fexofenadine and cyproheptadine were effective at inhibiting contractile responses. Cimetidine (H2-antagonist) enhanced increases in baseline tension in response histamine, whereas amthamine (H2-agonist) induced relaxation. Although thioperamide (H3/H4-antagonist) increased baseline tension responses to histamine, selective H1/H2-receptor antagonism revealed no influence of these receptors. In detrusor preparations, pyrilamine, fexofenadine and cyproheptadine were effective at inhibiting baseline tension increases in response to histamine. Our findings provide evidence that histamine produces contractile responses both in the U&LP and detrusor via the H1-receptor, and this response is significantly inhibited by activation of the H2-receptor in the U&LP but not the detrusor.

The potential role of folate metabolism in interstitial cystitis

The topic of interstitial cystitis (IC), also known as painful bladder syndrome (PBS), and folate/one carbon metabolism has previously been unaddressed in research. This narrative review highlights a potential connection for those with mast cell-related IC and histamine-mediated pain that is explored through four conceptual sections. The first section focuses on the nature of mast cell involvement and histamine-mediated pain in some interstitial cystitis patients. The second section reviews the literature on folate status in wider allergic conditions. The third section addresses the role of folate and methylation in general in histamine excretion. Finally, folate metabolism and vascular function are addressed because of the vascular abnormalities present in some IC bladders.

Distribution of mast cell subtypes in interstitial cystitis: implications for novel diagnostic and therapeutic strategies?

AIMS

To identify the presence and geographical distribution of mast cell (MC) subtypes: MC_T (tryptase positive-chymase negative) and MC_TC (tryptase positive-chymase positive) in bladder tissue.

METHODS

Bladder tissue was obtained from patients with painful bladder syndrome/interstitial cystitis (n=14) and normal histology from University Hospital Southampton tissue bank. Sequential tissue slices were immunohistochemically stained for MC subtypes using anti-MC tryptase (for MC_T and MC_TC) and anti-MC chymase (for MC_TC). Stained sections were photographed, and positively stained MCs were quantified using ImageJ. Data were analysed using descriptive statistics and individual paired t-tests.

RESULTS

There was a significant difference in the density of MCs between each layer of the disease bladder, with the greatest accumulation within the detrusor (p<0.001). There was a significant increase in MC_TC subtype in the lamina (p=0.009) in painful bladder syndrome/interstitial cystitis.

CONCLUSIONS

Our results suggest that mastocytosis is present within all layers of disease bladder, especially the muscle layer. The varying increase in MC subtypes in the lamina and mucosa may explain the variability in painful bladder syndrome/interstitial cystitis symptoms. A high influx of MC_TC in the mucosa of individuals who also had ulceration noted within their diagnostic notes may be of the Hunner's ulcer subclassification. These findings suggest a relationship between the pathogenesis of MC subtypes and the clinical presentation of painful bladder syndrome/interstitial cystitis. A cohort study would further elucidate the diagnostic and/or therapeutic potential of MCs in patients with painful bladder syndrome/interstitial cystitis.

Bladder pain syndrome/interstitial cystitis is associated with asthma: A case-control study

OBJECTIVE

Although asthma and bladder pain syndrome/interstitial cystitis (BPS/IC) are considered to share similar pathophysiological pathways, the relationship between asthma and BPS/IC is uncertain. This case-control study aimed to investigate the relationship between prior asthma and BPS/IC using a large database in Taiwan.

MATERIALS AND METHODS

This study used data from the Taiwan Longitudinal Health Insurance Database 2005. We identified 500 female patients with BPS/IC as cases and 500 propensity score-matched females without BPS/IC as controls. We conducted logistic regressions to estimate the odds ratio (OR) and 95% confidence interval (CI) for prior asthma between cases and controls.

RESULTS

Results indicated that 143 (14.30%) of the total sampled patients had received a prior diagnosis of asthma. Moreover, prior asthma was found in 86 (17.20%) cases and 57 (11.40%) controls. The OR of prior asthma for cases was 1.61 (95%CI: 1.13-2.32) compared to propensity score-matched controls. Additionally, the ORs of prior asthma for females with BPS/IC aged 18-59 and ≥60 years were 1.72 (95%CI: 1.11-2.69) and 1.40 (95%CI: 0.74-2.62), respectively, compared to controls.

CONCLUSIONS

We concluded that prior asthma was significantly associated with BPS/IC in a female Taiwanese population.

Digital quantitative analysis of mast cell infiltration in interstitial cystitis

AIMS

To evaluate the significance of mast cell infiltration in interstitial cystitis (IC) by comparison with equally inflamed controls using a digital quantification technique.

METHODS

Bladder biopsy specimens from 31 patients with Hunner type IC and 38 patients with non-Hunner type IC were analyzed. Bladder biopsy specimens from 37 patients without IC, including 19 non-specific chronic cystitis ("non-IC cystitis") specimens and 18 non-inflamed bladder ("normal bladder") specimens, were used as controls. Mast cell tryptase-, CD3-, CD20-, and CD138-immunoreactive cells were quantified using digital image analysis software to evaluate both mast cell and lymphoplasmacytic cell densities. Mast cell and lymphoplasmacytic cell densities were counted independently in the entire lamina propria and detrusor areas and compared among the four groups.

RESULTS

In the lamina propria, there were no significant differences in mast cell and lymphoplasmacytic cell densities between Hunner type IC and non-IC cystitis or between non-Hunner type IC and normal bladder specimens. In the detrusor, the mast cell densities were not significantly different among the four groups. Mast cell density was correlated with lymphoplasmacytic cell density, but not with clinical parameters.

CONCLUSIONS

Mast cell density is not significantly different between IC specimens and non-IC control specimens with a similar degree of background inflammation. The intensity of mast cell infiltration generally correlated with that of lymphoplasmacytic cells. We conclude that mast cell count is of no value in the differential diagnosis between IC and other etiologies.

Mast Cell-Mediated Mechanisms of Nociception

Mast cells are tissue-resident immune cells that release immuno-modulators, chemo-attractants, vasoactive compounds, neuropeptides and growth factors in response to allergens and pathogens constituting a first line of host defense. The neuroimmune interface of immune cells modulating synaptic responses has been of increasing interest, and mast cells have been proposed as key players in orchestrating inflammation-associated pain pathobiology due to their proximity to both vasculature and nerve fibers. Molecular underpinnings of mast cell-mediated pain can be disease-specific. Understanding such mechanisms is critical for developing disease-specific targeted therapeutics to improve analgesic outcomes. We review molecular mechanisms that may contribute to nociception in a disease-specific manner.

Mast cells in chronic inflammation, pelvic pain and depression in women

Inflammatory and neuroinflammatory processes are increasingly recognized as critical pathophysiologic steps in the development of multiple chronic diseases and in the etiology of persistent pain and depression. Mast cells are immune cells now viewed as cellular sensors in inflammation and immunity. When stimulated, mast cells release an array of mediators to orchestrate an inflammatory response. These mediators can directly initiate tissue responses on resident cells, and may also regulate the activity of other immune cells, including central microglia. New evidence supports the involvement of peripheral and central mast cells in the development of pain processes as well as in the transition from acute, to chronic and neuropathic pain. That behavioral and endocrine states can increase the number and activation of peripheral and brain mast cells suggests that mast cells represent the immune cells that peripherally and centrally coordinate inflammatory processes in neuropsychiatric diseases such as depression and anxiety which are associated with chronic pelvic pain. Given that increasing evidence supports the activated mast cell as a director of common inflammatory pathways/mechanisms contributing to chronic and neuropathic pelvic pain and comorbid neuropsychiatric diseases, mast cells may be considered a viable target for the multifactorial management of both pain and depression.

IL-6, but not IL-4, stimulates chemokinesis and TNF stimulates chemotaxis of tissue mast cells: involvement of both mitogen-activated protein kinases and phosphatidylinositol 3-kinase signalling pathways

An increase in the number of mast cells within tissues is observed in many pathophysiological conditions. Current data indicate that migration of mature mast cells might be one of the key mechanisms responsible for rapid local accumulation of these cells. Considering that interleukin (IL)-6 and IL-4, as well as tumour necrosis factor (TNF), influence mast cell activity in various ways, the purpose of the current study was to examine whether these cytokines function as rat peritoneal mast cell chemoattractants. We showed that IL-4, in the concentration range from 10(-6) to 10(-3) ng/ml, did not induce a mast cell migratory response, even in the presence of laminin and fibronectin. Under the same experimental conditions, mast cells were shown to migrate in response to IL-6 stimulation in the presence of laminin. The optimal concentration of IL-6 for maximal migration of mast cells was 10(-4) ng/ml (i.e. approximately 5 nM). In comparison, the optimal concentration of TNF for maximal migration of mast cells was 5 x 10(-5) ng/ml (i.e. approximately 3 fM). IL-6-stimulated mast cell migration was the result of chemokinesis, whereas TNF-induced migration was the result of chemotaxis. Mast cell migratory responses to IL-6 and TNF were entirely blocked by specific anti-IL-6R and anti-TNFR1 antibodies. We also documented that the migration response of mast cells to stimulation with IL-6 and TNF was mediated through signal transduction pathways involving mitogen-activated protein kinases and phosphatidylinositol 3-kinase. Taken together, our results indicate that IL-6, as well as TNF, induces tissue mast cell migration. Thus, these proinflammatory cytokines can be responsible for mast cell accumulation at the site of diverse conditions accompanied by inflammation.

Cell signaling in interstitial cystitis/painful bladder syndrome

Evidence for several types of cell signaling abnormalities has been presented for patients with interstitial cystitis/painful bladder syndrome (IC/PBS), a poorly understood chronic painful bladder disorder for which currently there is no reliable effective therapy. Increases or decreases in various urine cytokines and growth factors have been found in patient specimens, along with abnormal expression of epithelial differentiation markers, growth factors, cell membrane proteins, neurotransmitters, and other cytokines in tissue biopsies and/or explanted bladder cells from IC/PBS patients. Some of the abnormalities found in bladder epithelial cells from IC/PBS patients have been shown to be induced in normal cells by an antiproliferative factor from IC/PBS bladder epithelial cells that binds to a functional cell membrane receptor (CKAP4/p63). Greater understanding of cell signaling events associated with this debilitating disorder may lead to the development of more effective therapies.

Tumor necrosis factor (TNF) is a potent rat mast cell chemoattractant

It is well known that mast cell number increases in local tissues under different pathophysiologic conditions, although the humoral factors that stimulate local mast cell accumulation within tissues are not yet well known. Taking into account that tumor necrosis factor (TNF) influences tissue mast cell activity in various ways, the aim of the present study was to investigate the chemotactic activity of TNF for rat peritoneal mast cells. We have found that TNF induces mast cell migratory response in a dose-dependent manner, even in the absence of extracellular matrix (ECM) proteins. Significant migration was observed at concentrations of TNF as low as approximately 3 fM; higher TNF concentrations caused significant inhibition of spontaneous mast cell migration. In the presence of ECM proteins, TNF induced migration of mast cells in a biphasic manner, with peaks of migration occurring at approximately 0.3 fM and approximately 60 pM (in the presence of fibronectin) and at approximately 0.6 fM and approximately 600 pM (in the presence of laminin). Under the same experimental conditions, RANTES induced dose-dependent mast cell migration, and the optimal concentration of this chemokine for maximal migration was approximately 13 nM. The mast cell migratory response to lower concentrations of TNF was chemotactic and to higher TNF concentrations was due to chemokinesis. TNF-induced mast cell migration was completely blocked by neutralizing anti-TNF and anti-TNFR1 antibodies. The tyrosine kinase inhibitor, genistein, significantly abrogated mast cell migration toward TNF. Additionally, we have documented that TNF does not induce degranulation of rat mast cells. Taken together, our results indicate that TNF serves as an extremely potent chemotactic factor for rat mast cells that would cause accumulation of these cells at the site of diverse pathophysiologic conditions accompanied by inflammation.

Transcription factor network downstream of protease activated receptors (PARs) modulating mouse bladder inflammation

BACKGROUND

All four PARs are present in the urinary bladder, and their expression is altered during inflammation. In order to search for therapeutic targets other than the receptors themselves, we set forth to determine TFs downstream of PAR activation in the C57BL/6 urinary bladders.

METHODS

For this purpose, we used a protein/DNA combo array containing 345 different TF consensus sequences. Next, the TF selected was validated by EMSA and IHC. As mast cells seem to play a fundamental role in bladder inflammation, we determined whether c-kit receptor deficient (Kit w/Kit w-v) mice have an abrogated response to PAR stimulation. Finally, TFEB antibody was used for CHIP/Q-PCR assay and revealed up-regulation of genes known to be downstream of TFEB.

RESULTS

TFEB, a member of the MiTF family of basic helix-loop-helix leucine zipper, was the only TF commonly up-regulated by all PAR-APs. IHC results confirm a correlation between inflammation and TFEB expression in C57BL/6 mice. In contrast, Kit w/Kit w-v mice did not exhibit inflammation in response to PAR activation. EMSA results confirmed the increased TFEB binding activity in C57BL/6 but not in Kit w/Kit w-v mice.

CONCLUSION

This is the first report describing the increased expression of TFEB in bladder inflammation in response to PAR activation. As TFEB belongs to a family of TFs essential for mast cell survival, our findings suggest that this molecule may influence the participation of mast cells in PAR-mediated inflammation and that targeting TFEB/MiTF activity may be a novel approach for the treatment of bladder inflammatory disorders.

Increased number of apoptotic endothelial cells in bladder of interstitial cystitis patients

In this study, we aimed to investigate possible abnormality of bladder endothelial cells in interstitial cystitis patients by detecting morphological changes such as apoptosis in bladder endothelial cells. A bladder biopsy specimen was collected from interstitial cystitis patients immediately after hydrodistension therapy. The patients were classified into two groups on the basis of their predominant symptom, one group of patients with bladder pain and another group of patients with urinary urgency. Dissociated cells from the biopsy specimen were analyzed by flow cytometry after staining with Annexin V and an anti-CD105 antibody. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) and electron microscopy were performed to confirm morphologic changes indicative of apoptosis. The percentage of Annexin V binding, an early apoptosis marker, was significantly higher in bladder endothelial cells from interstitial cystitis patients with pain [median 24.7% (range 15.1-77.2), n = 20, P < 0.01) than that from interstitial cystitis patients with urinary urgency [9.3% (range 0.7-19.11) n = 17) or control patients [1.5% (range 0.8-9.1), n = 7]. TUNEL staining showed apoptotic cells in microvascular endothelial cells but not in the endothelial cells of a venule. By electron microscopy, endothelial cells showed morphological changes indicative of apoptosis such as nuclear fragmentation. Our results indicate that increased apoptosis of bladder microvascular endothelial cells may play an important role in the pathogenesis of interstitial cystitis accompanied by bladder pain.

Estrogen receptor beta-deficient female mice develop a bladder phenotype resembling human interstitial cystitis

Interstitial cystitis/painful bladder syndrome is a disease seen mostly in women, and symptoms tend to be worse premenopausally or during ovulation. The four cardinal symptoms of interstitial cystitis/painful bladder syndrome are bladder pain, urgency, frequency, and nocturia. Estrogen has been implicated in the etiology of this disease, but the role of the two estrogen receptors (ER), ERalpha and ERbeta, has not been investigated. We found that, in the bladders of WT mice, ERbeta is expressed in the basal cell layer of the urothelium. Bladders of male ERbeta(-/-) mice were intact and morphologically indistinguishable from those of their WT littermates. However, in female ERbeta(-/-) mice, there was ulceration and atrophy of bladder urothelium concomitant with infiltration of gammadelta T cells concentrated in the areas of atrophy and shedding of urothelium. The data support the idea that activated gammadelta T cells are causing the damage to the urothelium. The hyperactivity of T cells may be because of an imbalance between ERalpha and ERbeta signaling in female ERbeta(-/-) mice. Our data suggest that reduced ERbeta signaling might have a role in the pathogenesis of interstitial cystitis, and ERbeta could be a candidate for a target of medical therapy.

The Mast Cell in Interstitial Cystitis: Role in Pathophysiology and Pathogenesis

Current evidence from clinical and laboratory studies confirms that mast cells play a central role in the pathogenesis and pathophysiology of interstitial cystitis (IC). In this article, we focus on the role of the mast cell in IC and examine the ways in which mast cells and other pathophysiologic mechanisms are interrelated in this disease. Identifying the patients with IC who have mast cell proliferation and activation will enable us to address this aspect of disease pathophysiology in these individuals with targeted pharmacotherapy to inhibit mast cell activation and mediator release.

Mandatory role of proteinase-activated receptor 1 in experimental bladder inflammation

Background

In general, inflammation plays a role in most bladder pathologies and represents a defense reaction to injury that often times is two edged. In particular, bladder neurogenic inflammation involves the participation of mast cells and sensory nerves. Increased mast cell numbers and tryptase release represent one of the prevalent etiologic theories for interstitial cystitis and other urinary bladder inflammatory conditions. The activity of mast cell-derived tryptase as well as thrombin is significantly increased during inflammation. Those enzymes activate specific G-protein coupled proteinase-activated receptors (PAR)s.

Four PARs have been cloned so far, and not only are all four receptors highly expressed in different cell types of the mouse urinary bladder, but their expression is altered during experimental bladder inflammation. We hypothesize that PARs may link mast cell-derived proteases to bladder inflammation and, therefore, play a fundamental role in the pathogenesis of cystitis.

Results

Here, we demonstrate that in addition to the mouse urinary bladder, all four PA receptors are also expressed in the J82 human urothelial cell line. Intravesical administration of PAR-activating peptides in mice leads to an inflammatory reaction characterized by edema and granulocyte infiltration. Moreover, the inflammatory response to intravesical instillation of known pro-inflammatory stimuli such as E. coli lipopolysaccharide (LPS), substance P, and antigen was strongly attenuated by PAR1-, and to a lesser extent, by PAR2-deficiency.

Conclusion

Our results reveal an overriding participation of PAR1 in bladder inflammation, provide a working model for the involvement of downstream signaling, and evoke testable hypotheses regarding the role of PARs in bladder inflammation. It remains to be determined whether or not mechanisms targeting PAR1 gene silencing or PAR1 blockade will ameliorate the clinical manifestations of cystitis.

Significance of complications of allergic diseases in young patients with interstitial cystitis

BACKGROUND

It was found that about one-half of interstitial cystitis (IC) patients have complications of allergic diseases. However, significance of the complications have not been studied.

PATIENTS AND METHODS

Thirty-four patients (age range 20 to 39 years old) meeting the diagnostic criteria of NIDDK established in 1987 were selected. Clinical allergic tests and significance of complications of allergic diseases were examined.

RESULTS

Eighty-six percent of young patients had complications of allergic diseases. In two patients, IC was a part of generalized allergic diseases. In 25 patients, IC was suggested to have some association with allergy. Of these 25 patients, there were alternating symptoms or proportionally changing symptoms of allergy and IC in 15 patients, and the number of eosinophils increased in six patients. Seven IC patients were considered to have developed allergic diseases only by chance without apparent association.

CONCLUSIONS

Complications of allergic diseases are frequent, particularly in young IC patients. The results suggest the involvement of allergy in about 80% of IC patients with complications of allergic diseases. In only 6% of patients, IC was a part of generalized allergic disease.

Gene expression profiling of inflammatory bladder disorders

Inflammation underlies all major bladder pathologies including malignancy and represents a defense reaction to injury caused by physical damage, chemical substances, micro-organisms or other agents. During acute inflammation, activation of specific molecular pathways leads to an increased expression of selected genes whose products attack the insult, but ultimately should protect the tissue from the noxious stimulus. However, once the stimulus ceases, gene-expression should return to basal levels to avoid tissue damage, fibrosis, loss of function, and chronic inflammation. If this down-regulation does not occur, tissue fibrosis occurs as a serious complication of chronic inflammation. Although sensory nerve and most cells products are known to be key parts of the inflammatory puzzle, other key molecules are constantly being described that have a role in bladder inflammation. Therefore, as the database describing the repertoire of inflammatory mediators implicated in bladder inflammation increases, the central mechanisms by which injury can induce inflammation, cell damage, and repair often becomes less rather than more clear. To make sense of the vast knowledge of the genes involved in the inflammatory response may require analysis of the patterns of change and the elucidation of gene networks far more than definition of additional members of inflammatory cascades. This review discuss the appropriate use of microarray technology, which promises to solve both of these problems as well as identifying key molecules and mechanisms involved in the transition between acute and chronic inflammation.

Gene expression profiling of mouse bladder inflammatory responses to LPS, substance P, and antigen-stimulation

Inflammatory bladder disorders such as interstitial cystitis (IC) deserve attention since a major problem of the disease is diagnosis. IC affects millions of women and is characterized by severe pain, increased frequency of micturition, and chronic inflammation. Characterizing the molecular fingerprint (gene profile) of IC will help elucidate the mechanisms involved and suggest further approaches for therapeutic intervention. Therefore, in the present study we used established animal models of cystitis to determine the time course of bladder inflammatory responses to antigen, Escherichia coli lipopolysaccharide (LPS), and substance P (SP) by morphological analysis and cDNA microarrays. The specific aim of the present study was to compare bladder inflammatory responses to antigen, LPS, and SP by morphological analysis and cDNA microarray profiling to determine whether bladder responses to inflammation elicit a specific universal gene expression response regardless of the stimulating agent. During acute bladder inflammation, there was a predominant infiltrate of polymorphonuclear neutrophils into the bladder. Time-course studies identified early, intermediate, and late genes that were commonly up-regulated by all three stimuli. These genes included: phosphodiesterase 1C, cAMP-dependent protein kinase, iNOS, beta-NGF, proenkephalin B and orphanin, corticotrophin-releasing factor (CRF) R, estrogen R, PAI2, and protease inhibitor 17, NFkB p105, c-fos, fos-B, basic transcription factors, and cytoskeleton and motility proteins. Another cluster indicated genes that were commonly down-regulated by all three stimuli and included HSF2, NF-kappa B p65, ICE, IGF-II and FGF-7, MMP2, MMP14, and presenilin 2. Furthermore, we determined gene profiles that identify the transition between acute and chronic inflammation. During chronic inflammation, the urinary bladder presented a predominance of monocyte/macrophage infiltrate and a concomitant increase in the expression of the following genes: 5-HT 1c, 5-HTR7, beta 2 adrenergic receptor, c-Fgr, collagen 10 alpha 1, mast cell factor, melanocyte-specific gene 2, neural cell adhesion molecule 2, potassium inwardly-rectifying channel, prostaglandin F receptor, and RXR-beta cis-11-retinoic acid receptor. We conclude that microarray analysis of genes expressed in the bladder during experimental inflammation may be predictive of outcome. Further characterization of the inflammation-induced gene expression profiles obtained here may identify novel biomarkers and shed light into the etiology of cystitis.

Mast cell involvement in interstitial cystitis: a review of human and experimental evidence

Interstitial cystitis (IC) is a heterogeneous syndrome of unknown etiology. Altered bladder glycosaminoglycans lining and bladder mastocytosis have been documented in IC. The objective of this article is to critically examine the published data on bladder mastocytosis in clinical, experimental, and animal studies, with particular emphasis on morphologic evidence of mast cell increase and activation. The literature on bladder mastocytosis and mast cell activation in IC is critically reviewed with particular reference to staining methodology, tryptase immunoreactivity, and electron microscopy. Data from humans and animal models of IC are included. Mastocytosis in IC is best documented by tryptase immunocytochemical staining. Standard surgical stains such as Giemsa and toluidine blue routinely underestimate the degree of mastocytosis. Mast cells are 6- to 8-fold higher in the detrusor compared with controls in "classic IC," and 2- to 3-fold higher in "nonulcerative" IC. Detrusor mastocytosis occurs in both classic and nonulcer IC. Mucosal mast cell increase is present in nonulcerative IC. Mast cell activation without typical exocytosis occurs in the mucosa and submucosa. Activation of mast cells, irrespective of bladder location or degree of mastocytosis, is significant. Mast cell-derived vasoactive and proinflammatory molecules may contribute to the pathogenesis of IC.

New agents for the medical treatment of interstitial cystitis

Interstitial cystitis (IC) is a painful, sterile, disorder of the urinary bladder characterised by urgency, frequency, nocturia and pain. IC occurs primarily in women but also in men with recent findings indicating that chronic, abacterial prostatitis may be a variant of this condition. The prevalence of IC has ranged from about 8 - 60 cases/100,000 female patients depending on the population evaluated. About 10% of patients have severe symptoms that are associated with Hunner's ulcers on bladder biopsy; the rest could be grouped in those with or without bladder inflammation. Symptoms of IC are exacerbated by stress, certain foods and ovulatory hormones. Many patients also experience allergies, irritable bowel syndrome (IBS) and migraines. There have been various reports indicating dysfunction of the bladder glycosaminoglycan (GAG) protective layer and many publications showing a high number of activated bladder mast cells. Increasing evidence suggests that neurogenic inflammation and/or neuropathic pain is a major component of IC pathophysiology. Approved treatments so far include intravesical administration of dimethylsulphoxide (DMSO) or oral pentosanpolysulphate (PPS). New treatments focus on the combined use of drugs that modulate bladder sensory nerve stimulation (neurolytic agents), inhibit neurogenic activation of mast cells, or provide urothelial cytoprotection, together with new drugs with anti-inflammatory activity.