BCG invokes superior STING-mediated innate immune response over radiotherapy in a carcinogen murine model of urothelial cancer

Radiation and bacillus Calmette-Guérin (BCG) instillations are used clinically for treatment of urothelial carcinoma, but the precise mechanisms by which they activate an immune response remain elusive. The role of the cGAS-STING pathway has been implicated in both BCG and radiation-induced immune response; however, comparison of STING pathway molecules and the immune landscape following treatment in urothelial carcinoma has not been performed. We therefore comprehensively analyzed the local immune response in the bladder tumor microenvironment following radiotherapy and BCG instillations in a well-established spontaneous murine model of urothelial carcinoma to provide insight into activation of STING-mediated immune response. Mice were exposed to the oral carcinogen, BBN, for 12 weeks prior to treatment with a single 15 Gy dose of radiation or three intravesical instillations of BCG (1 × 108  CFU). At sacrifice, tumors were staged by a urologic pathologist and effects of therapy on the immune microenvironment were measured using the NanoString Myeloid Innate Immunity Panel and immunohistochemistry. Clinical relevance was established by measuring immune biomarker expression of cGAS and STING on a human tissue microarray consisting of BCG-treated non-muscle-invasive urothelial carcinomas. BCG instillations in the murine model elevated STING and downstream STING-induced interferon and pro-inflammatory molecules, intratumoral M1 macrophage and T-cell accumulation, and complete tumor eradication. In contrast, radiotherapy caused no changes in STING pathway or innate immune gene expression; rather, it induced M2 macrophage accumulation and elevated FoxP3 expression characteristic of immunosuppression. In human non-muscle-invasive bladder cancer, STING protein expression was elevated at baseline in patients who responded to BCG therapy and increased further after BCG therapy. Overall, these results show that STING pathway activation plays a key role in effective BCG-induced immune response and strongly indicate that the effects of BCG on the bladder cancer immune microenvironment are more beneficial than those induced by radiation. © 2021 The Pathological Society of Great Britain and Ireland.

TERT promoter mutations and other prognostic factors in patients with advanced urothelial carcinoma treated with an immune checkpoint inhibitor

BACKGROUND

Immune checkpoint inhibitors (ICI) can achieve durable responses in a subset of patients with locally advanced or metastatic urothelial carcinoma (aUC). The use of tumor genomic profiling in clinical practice may help suggest biomarkers to identify patients most likely to benefit from ICI.

METHODS

We undertook a retrospective analysis of patients treated with an ICI for aUC at a large academic medical center. Patient clinical and histopathological variables were collected. Responses to treatment were assessed for all patients with at least one post-baseline scan or clear evidence of clinical progression following treatment start. Genomic profiling information was also collected for patients when available. Associations between patient clinical/genomic characteristics and objective response were assessed by logistic regression; associations between the characteristics and progression-free survival (PFS) and overall survival (OS) were examined by Cox regression. Multivariable analyses were performed to identify independent prognostic factors.

RESULTS

We identified 119 aUC patients treated with an ICI from December 2014 to January 2020. Genomic profiling was available for 78 patients. Overall response rate to ICI was 29%, and median OS (mOS) was 13.4 months. Favorable performance status at the start of therapy was associated with improved OS (HR 0.46, p=0.025) after accounting for other covariates. Similarly, the presence of a TERT promoter mutation was an independent predictor of improved PFS (HR 0.38, p=0.012) and OS (HR 0.32, p=0.037) among patients who had genomic profiling available. Patients with both a favorable performance status and a TERT promoter mutation had a particularly good prognosis with mOS of 21.1 months as compared with 7.5 months in all other patients (p=0.03).

CONCLUSIONS

The presence of a TERT promoter mutation was an independent predictor of improved OS in a cohort of aUC patients treated with an ICI who had genomic data available. Most of the clinical and laboratory variables previously shown to be prognostic in aUC patients treated with chemotherapy did not have prognostic value among patients treated with an ICI. Genomic profiling may provide important prognostic information and affect clinical decision making in this patient population. Validation of these findings in prospective patient cohorts is needed.

Urothelial Carcinoma In Situ of the Bladder: Correlation of CK20 Expression With Adaptive Immune Resistance, Response to BCG Therapy, and Clinical Outcome

Immunohistochemical stains have been suggested to aid in diagnostically challenging cases of urothelial carcinoma in-situ (CIS). Although full thickness immunostaining for CK20 is supportive of CIS, a subset of CIS cases is CK20(-), the clinical significance of which was unknown. This study included 43 patients with primary diagnosis of bladder CIS including 32 with only CIS, 5 with CIS and separate noninvasive high-grade papillary urothelial carcinoma, and 6 with CIS and separate high-grade urothelial carcinoma with lamina propria invasion. Digital morphometric image analysis showed that the average nuclear areas of enlarged nuclei were similar in CK20(+) and CK20(-) CIS (26.9 vs. 24.5 µM2; P=0.31). Average Ki67 index for CK20(+) CIS was higher than CK20(-) CIS (31.1% vs. 18.3%; P=0.03). Patients with CK20(+) CIS [28 (65%)] and patients with CK20(-) CIS [15 (35%)] had the same rates of Bacillus Calmete-Guerin (BCG) failure but patients with CK20(-) CIS had higher stage progression [3 CK20(+) (11%) vs. 6 CK20(-) (40%); P=0.02]. Given recent approval of immune checkpoint inhibitors in patients with CIS refractory to BCG, programmed death ligand-1 expression and colocalization with CD8(+) lymphocytes was investigated as signature of adaptive immune response and was seen in 8 patients regardless of CK20 status and exclusively among patients who failed BCG. Our results confirm that negative CK20 IHC does not exclude CIS and that those patients have similar clinical outcomes as patients with CK20(+) CIS. Programmed death ligand-1 and CD8 colocalization seen among patients who failed BCG therapy is an easy assay to perform to identify patients who could potentially benefit from combined BCG therapy and immune checkpoint inhibition.

Shionone alleviates NLRP3 inflammasome mediated pyroptosis in interstitial cystitis injury

Shionone is a triterpenoid component derived from the herbal medicine Aster tataricus, and it has been reported to possess marked anti-inflammatory properties. The activation of NLRP3 inflammasome plays an important role in cystitis, and the effect of Shionone on NLRP3 inflammasome-dependent pyroptosis remains unclear. In this study, we established an interstitial cystitis (IC) rat model and SV-HUC-1 cell model with CYP or LPS + ATP treatment to mimic inflammation response and induce NLRP3 inflammasome activation. Shionone treatment significantly attenuated the bladder wet weight, score of edema and hemorrhage, enhanced the viability of SV-HUC-1 cell, decreased the rate of pyroptosis. Moreover, Shionone reduced the expression of NF-κB, NLRP3, ASC, Pro-caspase-1, Caspase-1, GSDMD, GSDMD-N at the mRNA and protein levels both in rat and SV-HUC-1 cell model, demonstrating NLRP3 inflammasome pathway was blocked and pyroptosis degree was reduced. These results indicated that Shionone could alleviate interstitial cystitis in Rat model and enhancing the viability of SV-HUC-1 cells via NF-κB/NLRP3/GSDMD-N pathway, which illustrated that Shionone could be used as a drug candidate for the treatment of interstitial cystitis.

Radiation of the urinary bladder attenuates the development of lipopolysaccharide-induced cystitis

In the present study we assessed how ionizing radiation affects TLR4-stimulated immune activation in lipopolysaccharide (LPS)-induced cystitis. LPS or saline was administered intravesically to female rats followed by urinary bladder irradiation (20 Gy) 24 h later or sham treatment. Presence in the urinary bladder of inflammatory cells (mast cells, CD3+, ionized calcium-binding adapter molecule 1 (Iba-1)+, CD68+, CD40+, CD80+, CD11c + and CD206 + cells) and expression of oxidative stress (8-OHdG), hypoxia (HIF1α) and anti-oxidative responses (NRF2, HO-1, SOD1, SOD2, catalase) were assessed 14 days later with western blot, qPCR and/or immunohistochemistry. LPS stimulation resulted in a decrease of Iba-1 + cells in the urothelium, an increase in mast cells in the submucosa and a decrease in the bladder protein expression of HO-1, while no changes in the bladder expression of 8-OHdG, NRF2, SOD1, SOD2, catalase and HIF1α were observed. Bladder irradiation inhibited the LPS-driven increase in mast cells and the decrease in Iba1 + cells. Combining LPS and radiation increased the expression of 8-OHdG and number of CD3-positive cells in the urothelium and led to a decrease in NRF2α gene expression in the urinary bladder. In conclusion, irradiation may attenuate LPS-induced immune responses in the urinary bladder but potentiates LPS-induced oxidative stress, which as a consequence may have an impact on the urinary bladder immune sensing of pathogens and danger signals.

CD4+ T cells induce rejection of urothelial tumors after immune checkpoint blockade

Immune checkpoint blockade (ICB) provides clinical benefit to a minority of patients with urothelial carcinoma (UC). The role of CD4+ T cells in ICB-induced antitumor activity is not well defined; however, CD4+ T cells are speculated to play a supportive role in the development of CD8+ T cells that kill tumor cells after recognition of tumor antigens presented by MHC class I. To investigate the mechanisms of ICB-induced activity against UC, we developed mouse organoid-based transplantable models that have histologic and genetic similarity to human bladder cancer. We found that ICB can induce tumor rejection and protective immunity with these systems in a manner dependent on CD4+ T cells but not reliant on CD8+ T cells. Evaluation of tumor infiltrates and draining lymph nodes after ICB revealed expansion of IFN-γ-producing CD4+ T cells. Tumor cells in this system express MHC class I, MHC class II, and the IFN-γ receptor (Ifngr1), but none were necessary for ICB-induced tumor rejection. IFN-γ neutralization blocked ICB activity, and, in mice depleted of CD4+ T cells, IFN-γ ectopically expressed in the tumor microenvironment was sufficient to inhibit growth of tumors in which the epithelial compartment lacked Ifngr1. Our findings suggest unappreciated CD4+ T cell-dependent mechanisms of ICB activity, principally mediated through IFN-γ effects on the microenvironment.

FGFR3 mutation increases bladder tumourigenesis by suppressing acute inflammation

Recent studies of muscle-invasive bladder cancer show that FGFR3 mutations are generally found in a luminal papillary tumour subtype that is characterised by better survival than other molecular subtypes. To better understand the role of FGFR3 in invasive bladder cancer, we examined the process of tumour development induced by the tobacco carcinogen OH-BBN in genetically engineered models that express mutationally activated FGFR3 S249C or FGFR3 K644E in the urothelium. Both occurrence and progression of OH-BBN-driven tumours were increased in the presence of an S249C mutation compared to wild-type control mice. Interestingly, at an early tumour initiation stage, the acute inflammatory response in OH-BBN-treated bladders was suppressed in the presence of an S249C mutation. However, at later stages of tumour progression, increased inflammation was observed in S249C tumours, long after the carcinogen administration had ceased. Early-phase neutrophil depletion using an anti-Ly6G monoclonal antibody resulted in an increased neutrophil-to-lymphocyte ratio at later stages of pathogenesis, indicative of enhanced tumour pathogenesis, which supports the hypothesis that suppression of acute inflammation could play a causative role. Statistical analyses of correlation showed that while initial bladder phenotypes in morphology and inflammation were FGFR3-dependent, increased levels of inflammation were associated with tumour progression at the later stage. This study provides a novel insight into the tumour-promoting effect of FGFR3 mutations via regulation of inflammation at the pre-tumour stage in the bladder. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Evaluation of Sienna Cancer Diagnostics hTERT Antibody on 500 Consecutive Urinary Tract Specimens

OBJECTIVES

Telomerase activity can be detected in up to 90% of urothelial carcinomas (UC). Telomerase activity can also be detected in urinary tract cytology (UTC) specimens and indicate an increased risk of UC. We evaluated the performance of a commercially available antibody that putatively binds the telomerase reverse transcriptase (hTERT) subunit on 500 UTC specimens.

STUDY DESIGN

Unstained CytospinTM preparations were created from residual urine specimens and were stained using the anti-hTERT antibody (SCD-A7). Two algorithms were developed for concatenating the hTERT result and cytologic diagnosis: a "no indeterminates algorithm," in which a negative cytology and positive hTERT result are considered positive, and a "high-specificity algorithm," in which a negative cytology and positive hTERT result are considered indeterminate (and thus negative for comparison to the gold standard).

RESULTS

The "no indeterminates algorithm" and "high-specificity algorithm" yielded a sensitivity of 60.6 and 52.1%, a specificity of 70.4 and 90.7%, a positive predictive value of 39.1 and 63.8%, and a negative predictive value of 85.0 and 85.8%, respectively.

CONCLUSIONS

A positive hTERT result may identify a subset of patients with an increased risk of high-grade UC (HGUC) who may otherwise not be closely followed, while a negative hTERT immunocytochemistry result is associated with a reduction in risk for HGUC.

TGFβ attenuates tumour response to PD-L1 blockade by contributing to exclusion of T cells

Therapeutic antibodies that block the programmed death-1 (PD-1)-programmed death-ligand 1 (PD-L1) pathway can induce robust and durable responses in patients with various cancers, including metastatic urothelial cancer. However, these responses only occur in a subset of patients. Elucidating the determinants of response and resistance is key to improving outcomes and developing new treatment strategies. Here we examined tumours from a large cohort of patients with metastatic urothelial cancer who were treated with an anti-PD-L1 agent (atezolizumab) and identified major determinants of clinical outcome. Response to treatment was associated with CD8+ T-effector cell phenotype and, to an even greater extent, high neoantigen or tumour mutation burden. Lack of response was associated with a signature of transforming growth factor β (TGFβ) signalling in fibroblasts. This occurred particularly in patients with tumours, which showed exclusion of CD8+ T cells from the tumour parenchyma that were instead found in the fibroblast- and collagen-rich peritumoural stroma; a common phenotype among patients with metastatic urothelial cancer. Using a mouse model that recapitulates this immune-excluded phenotype, we found that therapeutic co-administration of TGFβ-blocking and anti-PD-L1 antibodies reduced TGFβ signalling in stromal cells, facilitated T-cell penetration into the centre of tumours, and provoked vigorous anti-tumour immunity and tumour regression. Integration of these three independent biological features provides the best basis for understanding patient outcome in this setting and suggests that TGFβ shapes the tumour microenvironment to restrain anti-tumour immunity by restricting T-cell infiltration.

Immunotherapy for Patients with Advanced Urothelial Cancer: Current Evidence and Future Perspectives

In recent years, immunotherapy has produced encouraging results in a rapidly increasing number of solid tumors. The responsiveness of bladder cancer to immunotherapy was first established in nonmuscle invasive disease in 1976 with intravesical instillations of bacillus Calmette-Guérin (BCG). Very recently immune checkpoint inhibitors demonstrated good activity and significant efficacy in metastatic disease. In particular the best results were obtained with programmed death-ligand-1 (PD-L1) and programmed death-1 (PD-1) inhibitors, but many other immune checkpoint inhibitors, including anti-cytotoxic T-lymphocyte-associated protein-4 (CTLA-4) antibodies, are currently under investigation in several trials. Simultaneously other therapeutic strategies which recruit an adaptive immune response against tumoral antigens or employ externally manipulated tumor infiltrating lymphocytes might change the natural history of bladder cancer in the near future. This review describes the rationale for the use of immunotherapy in bladder cancer and discusses recent and ongoing clinical trials with checkpoint inhibitors and other novel immunotherapy agents.

Immunotherapy in urothelial cancer, part 1: T-cell checkpoint inhibition in advanced or metastatic disease

Cancer of the urothelium is the sixth most common cancer in the United States and is seen predominantly in men. Most cases of this disease present as non-muscle-invasive bladder cancer (NMIBC), with cancer recurrence or progression to muscle-invasive cancer in more than 50% of patients after initial therapy. NMIBC is an immune-responsive disease, as indicated by the use of intravesical bacillus Calmette-Guérin as treatment for more than 3 decades. More recently, immunotherapy has seen much progress in a variety of cancers, including advanced and metastatic bladder cancer, in which historical 5-year survival rates are approximately 15%. The advent of T-cell checkpoint inhibitors, especially those directed at programmed death 1 (PD-1) and its ligand (PD-L1), has had a significant effect on the therapy of advanced urothelial cancer. This had led to accelerated approval by the US Food and Drug Administration for atezolizumab and nivolumab in advanced urothelial cancer previously treated with platinum-based chemotherapy. In addition, level 1 evidence supports the use of pembrolizumab over single-agent tubulin-directed chemotherapy in the same setting. Several other treatments with immune-mediating mechanisms of action are in development and hold great promise, including monoclonal antibodies directed at other checkpoint molecules, oncolytic virus therapy, adoptive T-cell therapy, combination immunotherapy, and antibody-drug conjugates. This review focuses on the recent development of T-cell checkpoint inhibitors in advanced and metastatic urothelial cancer and addresses their potential use in combination. It also discusses a spectrum of novel immunotherapies with potential use in urothelial cancer.

Hyaluronic acid decreases IL-6 and IL-8 secretion and permeability in an inflammatory model of interstitial cystitis

Hyaluronic acid (HA) has received a lot of attention recently as a biomaterial with applications in wound healing, drug delivery, vascular repair and cell and/or gene delivery. Interstitial cystitis (IC) is characterised by an increase in the permeability of the bladder wall urothelium due to loss of the glycosaminoglycan (GAG) layer. The degradation of the urothelium leads to chronic pain and urinary dysfunction. The aetiology of the degradation of the GAG layer in this instance is currently unknown. At a clinical level, GAG replacement therapy using a HA solution is currently utilised as a treatment for IC. However, there is a significant lack of data on the mechanism of action of HA in IC. The current study investigates the mechanistic effect of clinically relevant HA treatment on an in vitro model of IC using urothelial cells, examining cytokine secretion, GAG secretion and trans-epithelial permeability. This study demonstrates that HA can significantly decrease induced cytokine secretion (4-5 fold increase), increase sulphated GAG production (2-fold increase) and without altering tight junction expression, decrease trans-epithelial permeability, suggesting that the HA pathway is a clinical target and potential treatment vector.

Role of Hypoxia Inducible Factor-1α (HIF-1α) in Innate Defense against Uropathogenic Escherichia coli Infection

Uropathogenic E. coli (UPEC) is the primary cause of urinary tract infections (UTI) affecting approximately 150 million people worldwide. Here, we revealed the importance of transcriptional regulator hypoxia-inducible factor-1 α subunit (HIF-1α) in innate defense against UPEC-mediated UTI. The effects of AKB-4924, a HIF-1α stabilizing agent, were studied using human uroepithelial cells (5637) and a murine UTI model. UPEC adherence and invasion were significantly reduced in 5637 cells when HIF-1α protein was allowed to accumulate. Uroepithelial cells treated with AKB-4924 also experienced reduced cell death and exfoliation upon UPEC challenge. In vivo, fewer UPEC were recovered from the urine, bladders and kidneys of mice treated transurethrally with AKB-4924, whereas increased bacteria were recovered from bladders of mice with a HIF-1α deletion. Bladders and kidneys of AKB-4924 treated mice developed less inflammation as evidenced by decreased pro-inflammatory cytokine release and neutrophil activity. AKB-4924 impairs infection in uroepithelial cells and bladders, and could be correlated with enhanced production of nitric oxide and antimicrobial peptides cathelicidin and β-defensin-2. We conclude that HIF-1α transcriptional regulation plays a key role in defense of the urinary tract against UPEC infection, and that pharmacological HIF-1α boosting could be explored further as an adjunctive therapy strategy for serious or recurrent UTI.

Urinary tract infection (UTI), commonly caused by uropathogenic E.coli (UPEC), affects more than 150 million people worldwide, resulting in 14 million hospital visits per year and an estimated total cost of 6 billion dollars in direct health care. Due to the high prevalence of UTI and rapid emergence of antibiotic-resistant bacteria, new effective strategies to prevent and treat UTI are urgently needed. Here, we describe a global regulatory role of transcription factor hypoxia-inducible factor-1 (HIF-1) in innate antimicrobial defense against UPEC. HIF-1 stabilization reduces UPEC attachment to and invasion of uroepithelial cells, and protects bladders from UPEC-mediated cytotoxicity in vivo. In the murine UTI model, we found normal bladder HIF-1 expression is required for efficient UPEC clearance, since HIF-1-deficient mice suffer more severe infection than normal mice. Further studies showed that key elements of host protection provided by HIF-1 regulation are uroepithelial cell nitric oxide and antimicrobial peptide production. This study provides valuable insight into the importance of HIF-1 in supporting host immunity during UTI and its potential as a therapeutic target.

Association between C13ORF31, NOD2, RIPK2 and TLR10 polymorphisms and urothelial bladder cancer

Several evidences have been published linking polymorphism in genes involved in chronic or recurrent inflammation with increased tumor risk and progression. Nevertheless the influence of innate immune receptors in urothelial cancer risk and characteristics has not been sufficient explored. We studied the possible association of polymorphisms in genes encoding NOD2, RIPK2, TLR10 and C13ORF31 with the risk, clinical/pathological characteristics and outcomes of urothelial cancer. We have found association between RIPK2 (rs42490) and cancer risk (AA vs AT&TT, p=0042). In addition, we found statistical differences in TLR10 (rs4129009) gen between low and high tumor infiltration stage (p=0.033). NOD2 (rs9302752) and RIPK2 (rs42490) were found to be associated with development of lymph node metastasis (p=0.011 and p=0.015). Importantly we detect association of TLR10 (Log Rank=0.035) and RIPK2 (Log Rank=0040) with overall survival. Multivariate Cox analysis revealed that both SNPs were survival prognosis factor independent of tumor stage and grade. Our results indicate that innate immunity receptors play a role in modulating urothelial cancer risk and progression.

The differential immunological activities of Ganoderma lucidum on human pre-cancerous uroepithelial cells

AIMS OF THE STUDY

Ganoderma lucidum is active to stimulate immunological effector cells, but the effects on uroepithelial cells have never been explored. The present study compared the expression of major cytokines induced by the water (GLw) and ethanol (GLe) extracts of G. lucidum.

MATERIALS AND METHODS

The pre-cancerous human uroepithelial cell (HUC-PC) line was employed. A total of 15 cytokines, including major Th1/Th2 cytokines and chemokines, were measured in the complete media after 24h incubation with GLw and GLe. Additionally, the following assays were performed: cytotoxicity, apoptosis, migration of neutrophils, and nuclear factor-kappaB (NF-κB) DNA binding activity.

RESULTS

GLe inhibited the growth of HUC-PC cells through apoptosis. Interleukins IL-2, IL-6, and IL-8 were significantly up-regulated by GLe in dose-dependent manners, but not by GLw. However, MCP-1 level was significantly increased by GLw but was oppositely reduced by GLe. Furthermore, the elevation of cytokine expression was correlated with the enhancement of p50/p65 NF-κB activity induced by GLe. The elevated IL-8 levels in GLe-treated cells were also correlated with the migration of neutrophils.

CONCLUSIONS

GLe and GLw exhibited different immunological activities on the HUC-PC cells. In particular, the activities of GLe may favor the clearance of high risk urothelial cells, suggesting potent chemopreventive ingredients are extractable by ethanol from G. lucidum.

[Regulatory interconnections of cyclooxigenase and inducible no-synthase in urinary bladder epithelial cells of the frog Rana temporaria under action of bacterial stimuli]

Earlier we have shown that in epithelial cells of the frog urinary bladder under action of bacterial lipopolysaccharides (LPS) there is activated expression of inducible NO-synthase (iNOS) and there is increased the NO production, which can play an important role in providing protective cell reactions from pathogens. The goal of the present work consisted in study of cyclooxigenase (cOG) products and mechanisms of their regulatory effect on expression of iNOS under action of LPS. In experiments on urinary bladder epithelial cells on the frog Rana temporaria it has been shown that incubation of the cells for 21 h with LPS leads to a rise in production of PGE2 and nitrites, stable NO metabolites. Inhibitor of iNOS 1400W decreased sharply production of nitrites, but did not affect the PGE2 level. Both the basal and the LPS-stimulated level of PGE2 and nitrites were inhibited in the presence of selective cOG inhibitors--SC-560 (cOG-1) and NS-398 (cOG-2). The IC50 value amounted to 90, 220, and 470 microM for NS-398, SC-560, and diclofenac (unspecific inhibitor of both isoforms), respectively. PGE2 and butaprost, the EP2-receptor agonist, but not agonists of EP1/EP3 or EP1 receptors, partially eliminated the inhibitory action of diclofenac on production of nitrites. Action of PGE2 was accompanied by an increase in the intracellular cAMP. Analysis of expression of iNOS mRNA in the epithelial cells incubated with LPS or LPS + inhibitor of cOG has shown the LPS-stimulated rise in expression of iNOS mRNA to decrease sharply in the presence of SC-560 or NS-398. Thus, the epithelial cells of the frog urinary bladder have the effectively functioning system of the congenital immune protection against bacterial pathogens, the most important component of this system being PGE2 and NO. Analysis of mechanisms of regulatory interactions of cOG and iNOS indicates that in this cell type the main regulators of iNOS expression and of the nitrogen oxide level are products of the cOG catalytic activity.

Analysis of the reactivity of indirect immunofluorescence in patients with pemphigus foliaceus and pemphigus vulgaris using rat bladder epithelium as a substrate

OBJECTIVES

To evaluate the reactivity of indirect immunofluorescence using rat bladder epithelium as a substrate in patients with pemphigus foliaceus and pemphigus vulgaris from the Department of Dermatology, University of São Paulo Medical School, Brazil.

METHODS

Thirty-two patients (8 male and 24 female) from the Department of Dermatology, University of São Paulo Medical School, were selected. Three had mucosal pemphigus vulgaris, 20 had mucocutaneous pemphigus vulgaris, and 9 had pemphigus foliaceus. Patients' sera were tested by indirect immunofluorescence performed on human foreskin and rat bladder epithelium and by ELISA assays utilizing baculovirus-expressed recombinant desmoglein 3 and desmoglein 1.

RESULTS

No patients with mucosal pemphigus vulgaris, 5 of 20 patients with mucocutaneous pemphigus vulgaris (25%) and 4 of 9 patients with pemphigus foliaceus (44%) had positive indirect immunofluorescence using rat bladder epithelium as a substrate.

CONCLUSION

Indirect immunofluorescence using rat bladder epithelium as a substrate is recommended whenever a diagnosis of paraneoplastic pemphigus is considered. The identification of a subset of pemphigus foliaceus and pemphigus vulgaris patients that recognizes desmoplakins by this laboratory tool is critical to avoid the misdiagnosis of paraneoplastic pemphigus.

Interleukin-8 is essential for normal urothelial cell survival

Interleukin-8 (IL-8; CXCL8) has been shown to play a role in multiple cellular processes. Here, we report an additional role of IL-8 as a growth and essential survival factor for normal human urothelial cells. Supplementing exogenous recombinant human IL-8 to normal urothelial cells promoted cell growth through the Akt pathway. Inhibition of IL-8 expression by small inhibitory RNA (siRNA) caused normal urothelial cells to die. Addition of recombinant human IL-8 rescued the normal urothelial cells treated with IL-8 siRNA. This rescue effect could be blocked by antibodies to the IL-8 receptor CXCR1 but not by CXCR2, suggesting that normal urothelial cells normally have IL-8 autocrine or paracrine activity for survival and growth mediated by CXCR1. IL-8 mRNA levels were lower in samples from patients with interstitial cystitis, a urinary bladder disorder associated with urothelial cell dysfunction and/or loss. Taken together, these results suggest that IL-8 is an important normal urothelial growth factor and is necessary for normal urothelial cell survival in vitro and in vivo. Lower IL-8 expression levels in the urinary bladder may contribute to pathophysiology of interstitial cystitis.

[Lipopolysaccharide-mediated regulation of interleukin-6 in cultured human detrusor smooth muscle cells]

BACKGROUND

Interleukin-6 (IL-6) is a pleiotropic cytokine which shows elevated plasma and urine levels in cancer and inflammatory diseases of the urinary tract. The aim of the study is to define IL-6 target gene regulation in cultivated human detrusor smooth muscle cells.

PATIENTS AND METHODS

The expression of IL-6 and IL-6R (gp80, gp130) was studied by confocal immunofluorescence, rtPCR and Western blotting. Lipopolysaccharide (LPS) stimulation experiments were conducted in smooth muscle cell cultures derived from bladder biopsies of four male tumor patients.

RESULTS

IL-6 and IL-6R expression was found in urothelium, lamina propria and detrusor cells. LPS stimulation evoked a time-dependent synthesis and/or release of IL-6, IL-6R and STAT3.

CONCLUSIONS

Our results favor the notion that IL-6 can stimulate various cells of the human urinary bladder. Both detrusor cells and urothelium can serve as a source of elevated IL-6 levels. Finding genes regulated by IL-6 could be of great value for new therapeutical approaches in cancer and chronic inflammation of the lower urinary tract.

Modulation of host innate immune response in the bladder by uropathogenic Escherichia coli

Uropathogenic Escherichia coli (UPEC), the most frequent cause of urinary tract infection (UTI), is associated with an inflammatory response which includes the induction of cytokine/chemokine secretion by urothelial cells and neutrophil recruitment to the bladder. Recent studies indicate, however, that UPEC can evade the early activation of urothelial innate immune response in vitro. In this study, we report that infection with the prototypic UPEC strain NU14 suppresses tumor necrosis factor alpha (TNF-alpha)-mediated interleukin-8 (CXCL-8) and interleukin-6 (CXCL-6) secretion from urothelial cell cultures compared to infection with a type 1 piliated E. coli K-12 strain. Furthermore, examination of a panel of clinical E. coli isolates revealed that 15 of 17 strains also possessed the ability to suppress cytokine secretion. In a murine model of UTI, NU14 infection resulted in diminished levels of mRNAs encoding keratinocyte-derived chemokine, macrophage inflammatory peptide 2, and CXCL-6 in the bladder relative to infection with an E. coli K-12 strain. Furthermore, reduced stimulation of inflammatory chemokine production during NU14 infection correlated with decreased levels of bladder and urine myeloperoxidase and increased bacterial colonization. These data indicate that a broad phylogenetic range of clinical E. coli isolates, including UPEC, may evade the activation of innate immune response in the urinary tract, thereby providing a pathogenic advantage.

Expression of cyclooxygenase-2 in urinary bladder in rats with cyclophosphamide-induced cystitis

These studies examined the expression of cyclooxygenase-2 (COX-2) expression in the urothelium and suburothelial space and detrusor from rats treated with cyclophosphamide (CYP) to induce acute (4 h), intermediate (48 h), or chronic (10-day) cystitis. Western blot analysis and immunohistochemistry were used to demonstrate COX-2 expression. In whole mount preparations of urinary bladder, nerve fibers in the suburothelial plexus, and inflammatory cell infiltrates were characterized for COX-2 expression after CYP-induced cystitis. COX-2 expression significantly (P <or= 0.01) increased in the urothelium + suburothelium and detrusor smooth muscle with acute, intermediate, and chronic (10-day) CYP-induced cystitis, but expression in urothelium + suburothelium was significantly greater. CYP-induced upregulation of COX-2 showed by immunostaining in the urothelium + suburothelium was similar to that observed with Western blot analysis and also demonstrated COX-2 inflammatory cell infiltrates (CD86+) and nerve fibers (PGP+) in the suburothelial plexus. Although COX-2 expression was significantly (P <or= 0.01) increased in detrusor smooth muscle, immunohistochemistry failed to demonstrate an obvious change in COX-2-immunoreactivity (IR) in detrusor muscle, but COX-2 inflammatory infiltrates were present throughout the detrusor. COX-2-IR nerve fibers exhibited increased density in the suburothelial plexus with acute or chronic CYP-induced cystitis. COX-2-IR macrophages (CD86+) were present throughout the urinary bladder with acute and chronic CYP-induced cystitis. These studies demonstrate cellular targets in the urinary bladder where COX-2 inhibitors may act.

Mycobacterium bovis bacillus Calmette-Guérin (BCG) induces human CC- and CXC-chemokines in vitro and in vivo

Both CC- and CXC-chemokines are known to be potent leucocyte activators and chemoattractants and play important roles in inflammatory responses. However, chemokine response to bacillus Calmette-Guérin (BCG) infection remains incompletely defined. In this study, we investigated human CC- [macrophage-derived chemokine (MDC), monocyte chemoattractant protein (MCP)-1, macrophage inflammatory protein (MIP)-1alpha and eosinophil chemoattractant activity (eotaxin)] and CXC-interferon-inducible protein (IP)-10 chemokine production in response to BCG stimulation. BCG efficiently induced all chemokines tested in the urine of four bladder cancer patients undergoing intravesical BCG immunotherapy. The peak urinary chemokine responses occurred generally between the fourth and sixth weekly treatment, except eotaxin, which was less predictable. To evaluate the effect of BCG on induction of chemokines in vitro, urothelial cell lines and peripheral blood mononuclear cells (PBMCs) were used. Although BCG induced no or marginal chemokines from urothelial SV-HUC-1, RT4 and T24 cells, BCG-derived cytokines [interleukin (IL)-1beta, interferon (IFN)-gamma and tumour necrosis factor (TNF)-alpha] induced all chemokines tested except eotaxin from these cell lines. BCG also efficiently induced all chemokines tested except eotaxin from PBMCs of both BCG-naive and BCG-vaccinated subjects. MCP-1 and MIP-1alpha emerged at 4-5 h post-BCG exposure (early chemokines); IP-10 elevated at day 1 and peaked at day 2 (intermediate chemokine); and MDC elevated at day 1 and peaked at day 7 (late chemokine). This kinetic pattern was paralleled with that of BCG-induced cytokines [early: TNF-alpha; intermediate: IL-6 and IL-10; and late: IFN-gamma and granulocyte-macrophage colony-stimulating factor (GM-CSF)]. Taken together, these results indicate that BCG directly or indirectly induces human CC- and CXC-chemokine production, which may represent one of the mechanisms by which BCG exerts its anti-tumour activity.

Urothelial CD44 FacilitatesEscherichia coliInfection of the Murine Urinary Tract

Escherichia coli is the most common pathogen found in urinary tract infections (UTIs), mainly affecting children and women. We report that CD44, a hyaluronic acid (HA) binding protein that mediates cell-cell and cell-matrix interactions, facilitates the interaction of E. coli with urothelial cells and thus the infection of the host. We found that CD44 is constitutively expressed on urothelial cells and that HA accumulates in E. coli-induced UTI. In CD44-deficient mice, the bacterial outgrowth was dramatically less compared with wild-type mice despite similar granulocyte influx in the bladder and in the kidney as well as comparable cytokines/chemokines levels in both genotypes. E. coli was able to bind HA, which adhered to CD44-positive tubular epithelial cells. Most importantly, the interaction of CD44 on tubular epithelial cells with HA facilitated the migration of E. coli through the epithelial monolayer. The results provide evidence that CD44 on urothelial cells facilitates E. coli UTI. Disruption of the interaction between CD44 and HA in the bladder may provide a new approach to prevent and to treat UTI.

Expression of TGFbeta-1 and Type I TGFbeta-receptor on sequential biopsies of renal transplants with chronic allograft nephropathy

The aim of this study was to determine the expression of transforming growth factor-beta (TGFbeta)-1 and type I TGFbeta-receptor on sequential biopsies from renal transplants with and without chronic allograft nephropathy. Twenty-four renal transplant recipients entered the study. They underwent sequential biopsies performed before (T1: 1.44 +/- 1.2 months) and 6 months after (T2: 15.96 +/- 7.2 months) transplantation. Lesions were graded according to the criteria of the Banff classification. C4d was detected by fluorescence microscopy. Immunohistochemistry was performed in order to identify cells expressing TGFbeta-1 and type I TGFbeta-receptor. In normal renal tissue (n = 4), TGFbeta-1 is expressed by tubular epithelial cells and endothelial cells lining glomerular and peritubular capillaries, whereas type 1 TGFbeta-receptor is expressed by tubular epithelial cells and smooth muscle cells in the media of arteries. In recipients with chronic allograft nephropathy (group 1, n = 14), diffuse epithelial expression of both molecules was found in more patients at T2 than at T1 (42.8% vs 21.4%). In contrast, this pattern of expression remained stable or decreased over time in recipients with long-term normal transplants (group 2, n = 10). Furthermore, type 1 TGFbeta-receptor was detected on the smooth muscle cells of arteries in 12/14 (85.7%) of recipients in group 1 and only in 4/9 (44.4%) of recipients in group 2. No relationship was noticed with regard to C4d deposits. These data suggest that the synthesis of TGFbeta-1 and type I TGFbeta-receptor increases over time in recipients developing chronic allograft nephropathy. Further studies are in progress in order to quantify mRNA of both molecules with real-time polymerase chain reaction.

Correlation between sigma2 receptor protein expression and histopathologic grade in human bladder cancer

Sigma2 (sigma2) receptor proteins are overexpressed in several tissues and tumour cell lines. Although the biomolecular mechanism of this overexpression must be elucidated, sigma2 receptor was considered a potential biomarker for monitoring solid tumour proliferation. In this study, we verified first sigma2 receptor overexpression by saturation analysis with radioligand in six human bladder cancer specimens, then if a possible correlation could be established between sigma2 overexpression and tumour tissue stage and grade. The results displayed that sigma2 receptor protein was normally expressed in human bladder and overexpressed in the case of high-grade transitional cell carcinomas. Moreover, these receptors were undetected in a low-grade squamous cell carcinoma and in a very rare form of anaplastic, large cells plasmacytoid cancer.

A novel mechanism of CD40-induced apoptosis of carcinoma cells involving TRAF3 and JNK/AP-1 activation

Membrane-presented CD40 agonists can induce apoptosis in carcinoma, but not normal homologous epithelial cells, whereas soluble agonists are growth inhibitory but not proapoptotic unless protein synthesis is blocked. Here we demonstrate that membrane-presented CD40 ligand (CD154) (mCD40L), but not soluble agonists, triggers cell death in malignant human urothelial cells via a direct mechanism involving rapid upregulation of TNFR-associated factor (TRAF)3 protein, without concomitant upregulation of TRAF3 mRNA, followed by activation of the c-Jun N-terminal kinase (JNK)/activator protein-1 (AP-1) pathway and induction of the caspase-9/caspase-3-associated intrinsic apoptotic machinery. TRAF3 knockdown abrogated JNK/AP-1 activation and prevented CD40-mediated apoptosis, whereas restoration of CD40 expression in CD40-negative carcinoma cells restored apoptotic susceptibility via the TRAF3/AP-1-dependent mechanism. In normal human urothelial cells, mCD40L did not trigger apoptosis, but induced rapid downregulation of TRAF2 and 3, thereby paralleling the situation in B-lymphocytes. Thus, TRAF3 stabilization, JNK activation and caspase-9 induction define a novel pathway of CD40-mediated apoptosis in carcinoma cells.

Effect of human anti-DNA antibodies on proximal renal tubular epithelial cell cytokine expression: implications on tubulointerstitial inflammation in lupus nephritis

This study aimed to investigate the effects of human anti-DNA antibodies (Ab) from patients with lupus on renal proximal tubular epithelial cells (PTEC), focusing on alterations in cell morphology and proinflammatory cytokine synthesis. Immunohistochemistry showed increased tubulointerstitial IL-6 expression and IgG deposition in renal biopsies from patients with diffuse proliferative lupus nephritis, not observed in controls or membranous lupus nephritis, which correlated with the severity of inflammatory cell infiltration. Sera from patients with lupus nephritis contained IgG that bound to cultured PTEC. Such binding increased with disease activity and correlated with the level of anti-DNA Ab. Incubation of PTEC with anti-DNA Ab that were isolated during active (active Ab) or inactive (inactive Ab) disease induced IL-6 synthesis, both apically and from the basolateral aspect. This was accompanied by altered cell morphology, increased cell proliferation (P < 0.05), and lactate dehydrogenase release (P < 0.05). The binding of inactive Ab and active Ab to PTEC resulted in differential and sequential upregulation of TNF-alpha, IL-1beta, and IL-6 secretion (P < 0.05). Early induction of TNF-alpha was observed with active Ab; the two then acted synergistically to induce IL-6 secretion. Exposure of PTEC to inactive Ab was associated with modest induction of TNF-alpha, which was not involved in downstream induction of other proinflammatory peptides. These data suggest distinct immunopathogenetic mechanisms during disease flare or remission. Conditioned media from human mesangial cells acted synergistically with anti-DNA Ab to induce cytokine secretion in PTEC. Results from these studies underscore the pivotal role of PTEC in the pathogenesis of tubulointerstitial inflammation and fibrosis in lupus nephritis.

Intrinsic expression of Th2 cytokines in urothelium of congenital ureteropelvic junction obstruction

BACKGROUND

The cytokine-producing ability of urothelium, a urinary tract barrier between urine and underlying connective tissue, may exacerbate the pathogenesis of congenital ureteropelvic junction obstruction (UPJ-O) disease. A role for urothelium in human urinary tract obstruction has rarely been described. In this study, we investigated the immunopathologic characteristics of, and cytokine production by, urothelium in children with congenital UPJ-O.

METHODS

Twenty-four children with congenital UPJ-O who had received pyeloplasty were enrolled. Morphologic abnormalities and pathologic and inflammatory changes of UPJ-O segments were studied. Expression of cytokines and chemokines in urothelium was investigated and compared with control tissue by immunohistochemistry (IHC), in situ hybridization (ISH), and urinary enzyme-linked immunosorbent assay (ELISA).

RESULTS

Atypical or simple hyperplasia of the urothelium with evidence of Ki67 over-expression was found frequently in UPJ-O. There were variable degrees of inflammatory cell and eosinophil infiltration. Augmented expression of IL-5 and eotaxin detected by IHC and ISH, and enhanced degranulation of tissue mast cells were observed in the urothelium of UPJ-O segments. IL-4, IFN-gamma, and TNF-alpha were undetectable. Significantly higher levels of urinary IL-5, IFN-gamma, and eotaxin were detected in urine collected from the obstructed kidney. Among these, high urinary IL5 and/or IFN-gamma levels were associated with more severe obstructive uropathy (P < 0.05).

CONCLUSION

Urothelium, like intestinal and respiratory epithelia, plays an active role in immunoregulation and may contribute to exacerbation of the pathogenesis of congenital UPJ-O. Many eosinophil-associated disease cytokines, which can lead to the degranulation of mast cells, are predominant regulators in UPJ-O urothelium.

[Status of extracellular matrix and adhesion markers in urothelial cancer of the urinary bladder]

39 cases of transitory cell (15 cases of well differentiated, 12-moderately and 12- poorly differentiated) urothelial bladder carcinoma were studied immunohistochemically. Expression of adhesion molecules, collagen, laminin and tenascsin was investigated. Their role in a decrease of a differentiation degree of urothelial carcinoma was revealed. The possibility of the above markers use for individual prognosis is demonstrated.

Osteoinductive properties of urothelium depend on inherent bone morphogenetic proteins (BMPs)

BACKGROUND

The mechanism of heterotopic ossicle formation induced by grafted transitional epithelium, described in several species, has not yet been elucidated. This phenomenon is not species specific, but in xenogeneic systems, immunosuppression of the host is needed to protect the implant long enough for it to exert its osteoinductive potency. We showed a strong correlation between the intensity of bone induction caused by implantation of HeLa cell lines and their ability to synthesize and secrete seven different isoforms of BMPs (bone morphogenetic proteins). We decided to discover whether the urothelium of guinea pig, having high osteoinductive potency, differs in BMP content from human urothelium, which does not induce heterotopic bone.

MATERIAL/METHODS

The RT-PCR technique was used to investigate the expression of BMP family genes. PCR products were directly sequenced with an ABI Prism 310 sequencer. The obtained sequences were analyzed using BLAST.

RESULTS

Two isoforms of BMP (BMP-3 and BMP-4) were detected in the guinea pig urinary bladder mucosa. The sequences of these products were identified by BLAST analysis and compared with human mRNA and protein. The experiment performed on human urinary bladder mucosa failed to detect the expression of these BMPs, while b-actin mRNA was detected.

CONCLUSIONS

Our findings explain the reason for the osteoinductive properties of guinea pig urothelium and are in line with the explanation of the osteoinductive properties of HeLa cells. Moreover, human urothelium, which did not express any BMP mRNA, therefore probably lacks osteoinductive competence.

Minireview: functions of the renal tract epithelium in coordinating the innate immune response to infection

Infection of the urinary tract remains one of the most common infections affecting mankind. Renal epithelial cells, being one of the first cells to come into contact with invading organisms, are in a key position to coordinate host defense. The epithelium not only provides a physical barrier to infection, but can also augment the immune response via the production of a number of inflammatory mediators and antimicrobial proteins. Recent work has demonstrated that cells of the innate immune system, including epithelial cells, express toll-like receptors (TLRs), with the capacity to recognize bacterial components. Although the exact mechanisms remain unclear, engagement of TLRs can lead to epithelial cell activation and the production of inflammatory mediators. These include complement proteins, other bactericidal peptides, and chemotactic cytokines. The resulting inflammatory infiltrate serves to aid bacterial clearance, but can also lead to renal damage. In this review, we describe how renal epithelial cells contribute to the innate immune response to ascending urinary tract infection. We specifically relate previous work to more recent developments in this field. An improved understanding of the mechanisms involved may highlight potential therapeutic avenues to aid bacterial clearance and prevent the renal scarring associated with infection.

Complement activation regulates the capacity of proximal tubular epithelial cell to stimulate alloreactive T cell response

Tissue expression of C3 is an unexpected regulator of the alloimmune response in mouse kidney transplantation. It is unclear, however, whether a direct or an indirect action of complement on the host immune response is involved. Also unknown is which of the complement effector products, cleaved C3, cleaved C5, or C5b-9, is responsible. Proximal tubular epithelial cells (PTEC) not only constitute a major target of the alloimmune response but also produce substantial amounts of C3. This study investigated the property of mouse PTEC to stimulate alloreactive T cells in a complement-dependent manner. The proliferative and cytokine responses of primed alloreactive T cells were measured after exposure to donor-specific PTEC that had been pretreated with normal mouse serum, heat-inactivated mouse serum, or complement- deficient (C3, C5, or C6) mouse sera to differentially deposit complement components. PTEC were able to stimulate alloreactive T cells in an antigen-specific manner. Complement activation leading to the deposition of cleaved C3 on PTEC enhanced the alloreactive T cell response. This complement-mediated stimulation of the T cell response was dependent on C3 but not on C5 or C6. The primary influence of tissue-bound complement was on CD4(+) T cells. Moreover, the effect of complement on alloreactive T cells was B7 dependent, shown by inhibition studies with CTLA4-Ig. These results suggest that donor epithelium-bound C3 can upregulate the alloimmune response. It is postulated that surface-bound C3 interacts with complement receptors on alloreactive T cells or on antigen presenting cells to increase allo-immune stimulation.

Expression and function of bradykinin B1 and B2 receptors in normal and inflamed rat urinary bladder urothelium

The bladder urothelium exhibits dynamic sensory properties that adapt to changes in the local environment. These studies investigated the localization and function of bradykinin receptor subtypes B1 and B2 in the normal and inflamed (cyclophosphamide (CYP)-induced cystitis) bladder urothelium and their contribution to lower urinary tract function in the rat. Our findings indicate that the bradykinin 2 receptor (B2R) but not the bradykinin 1 receptor (B1R) is expressed in control bladder urothelium. B2R immunoreactivity was localized throughout the bladder, including the urothelium and detrusor smooth muscle. Bradykinin-evoked activation of this receptor elevated intracellular calcium (EC(50) = 8.4 nM) in a concentration-related manner and evoked ATP release from control cultured rat urothelial cells. In contrast, B1R mRNA was not detected in control rat urinary bladder; however, following acute (24 h) and chronic (8 day) CYP-induced cystitis in the rat, B1R mRNA was detected throughout the bladder. Functional B1Rs were demonstrated by evoking ATP release and increases in [Ca(2+)](i) in CYP (24 h)-treated cultured rat urothelial cells with a selective B1 receptor agonist (des-Arg(9)-bradykinin). Cystometry performed on control anaesthetized rats revealed that intravesical instillation of bradykinin activated the micturition pathway. Attenuation of this response by the P2 receptor antagonist PPADS suggests that bradykinin-induced micturition facilitation may be due in part to increased purinergic responsiveness. CYP (24 h)-treated rats demonstrated bladder hyperactivity that was significantly reduced by intravesical administration of either B1 (des-Arg(10)-Hoe-140) or B2 (Hoe-140) receptor antagonists. These studies demonstrate that urothelial expression of bradykinin receptors is plastic and is altered by pathology.

Overexpression of human carcinoma-associated antigen in urothelial carcinoma of the bladder

CONTEXT

Human carcinoma-associated antigen (HCA) is a mucin protein whose level is increased in the sera of patients with a variety of carcinomas. We have previously shown that prostatic carcinoma overexpresses HCA in comparison to benign prostatic tissue. To our knowledge, expression of HCA in other tumors has not been reported previously.

OBJECTIVE

The current study was designed to determine if HCA is overexpressed in urothelial carcinoma (UCa) of the bladder.

DESIGN

Forty cystectomy specimens with UCa were selected, of which 27 cases had invasive UCa, 21 cases had a noninvasive component, and 36 cases had benign urothelium. Seven cystectomy specimens with benign conditions were chosen as controls. Anti-HCA monoclonal antibody HAE3 was used for immunohistochemical staining. Results were recorded as positive (> or =5% of cells staining and staining intensity 2+ or 3+) or negative (<5% of cells staining or staining intensity <2+) and analyzed using the Fisher exact test.

RESULTS

HAE3 staining was positive in 67% of invasive UCa, 29% of noninvasive UCa, but only 5% of benign urothelium specimens. The difference in HCA expression between benign urothelium and UCa and that between invasive and noninvasive UCa was statistically significant (P =.008). No statistically significant difference was found between low-grade and high-grade noninvasive papillary UCa (P =.06).

CONCLUSIONS

Human carcinoma-associated antigen is selectively overexpressed in a significant number of cases of UCa of the bladder, suggesting the potential utility of monitoring the serum and/or urine levels of HCA in monitoring patients with HCA-positive UCa for recurrence or progression.

Hyaluronan attenuates transforming growth factor-beta1-mediated signaling in renal proximal tubular epithelial cells

Increased expression of hyaluronan (HA) has been associated with both acute renal injury and progressive renal disease, although the functional significance of this remains unclear. There is overwhelming evidence that transforming growth factor (TGF)-beta1 is critical to the development of progressive renal disease. Recent studies suggest an interaction between HA and TGF-beta signaling in cancer cell biology. The aim of this study was to examine the potential role of HA as a modulator of TGF-beta1 function in renal proximal tubular epithelial cells (PTC). Under resting conditions, co-localization of the principal receptor for HA, CD44, and both the TGF-beta type I and type II receptors was demonstrated by immunoprecipitation and western analysis and further confirmed by immunocytochemistry and confocal microscopy. Stimulation of PTC with TGF-beta1 led to increased synthesis of both type III and type IV collagen assessed by Western analysis. Addition of HA did not alter collagen synthesis, but abrogated TGF-beta1-mediated increase in type III and type IV collagen. This effect was blocked by the addition of a blocking antibody to CD44 and also by inhibition of MAP kinase kinase (MEK) activity. Furthermore HA decreased TGF-beta1 activation of a luciferase-SMAD responsive construct, and decreased translocation of SMAD4 into the cell nucleus. We have previously demonstrated an anti-migratory effect of TGF-beta1 in a scratch wounding model. As with HA antagonism of TGF-beta1 extracellular matrix generation, HA reduced the anti-migratory effect of TGF-beta1 in a CD44-dependent manner. In contrast to the effect of TGF-beta1 on collagen synthesis, which is SMAD-dependent, the anti-migratory effect of TGF-beta1 in this model is known to be dependent of activation of RhoA. In the presence of HA, TGF-beta1-mediated activation of RhoA was also abrogated in a CD44-dependent manner. The results suggest that co-localization of CD44 and TGF-beta receptors facilitate modulation of both SMAD and non-SMAD-dependent TGF-beta1-mediated events by HA. Our results therefore suggest that alteration of HA synthesis may represent an endogenous mechanism to limit renal injury.

Renal tubular epithelial cell apoptosis by Fas-FasL–dependent self-injury can augment renal allograft injury

The role of Fas-FasL interactions in kidney allograft injury may be complex as renal tubular epithelial cells (TEC) express both Fas and FasL. The role and regulation of TEC self-injury has not been investigated. In co-cultures of TEC, FasL-bearing, Fas-null TEC was demonstrated to induce apoptosis of TEC-bearing Fas. Co-culturing effector lpr-TEC (M3.1-lpr) with target WT-TEC (CS3.7) at a ratio of 10:1 (E/T) induced 15.2 +/- 2.4% of target apoptosis as compared to its basal level of 2.6 +/- 0.3%. Similarly lpr-TEC induced apoptosis in gld-TEC (MRM-gld) from a basal level of 3.7 +/- 0.2% to 6.4 +/- 0.3%. Expression of kidney Fas-FasL on injury was tested in a renal transplant model. C57BL/6 (B6) mice were transplanted with Fas-deficient C3H-lpr/lpr or FasL mutation C3H-gld/gld kidneys as compared to normal (wild-type [WT]) C3H/Hej donors. Survival of both lpr and gld recipient was improved compared to WT donors (P <.05) as was function of lpr and gld kidneys indicated by a lower serum creatinine (LPR: 41 +/- 8 micromol/L; GLD: 52 +/- 7 micromol/L) as compared to the WT donors (84 +/- 8 micromol/L, P <.001). These results demonstrate that activated TEC may commit a novel and previously unreported form of self-injury (fractricide) through Fas-FasL. These results suggest that inhibition of renal Fas or FasL might be a useful strategy to prevent TEC loss during rejection.

Phospholipid metabolite production in human urothelial cells after protease-activated receptor cleavage

Our laboratory demonstrated previously that stimulation of protease-activated receptors (PARs) on the human urothelial carcinoma cell line RT4 results in activation of a calcium-independent phospholipase A(2) (iPLA(2)), leading to arachidonic acid and PGE(2) release. In this study, we have examined PAR activation in normal human urothelial cells (HUR) leading to the production of inflammatory or cytoprotective phospholipid metabolites. The presence of both PAR-1 and PAR-2 on HUR was confirmed by immunoblotting. Stimulation of PAR-1 with thrombin or PAR-2 by tryptase leads to activation of a membrane-associated iPLA(2) and the production of platelet-activating factor, arachidonic acid, and PGE(2). These responses were all blocked by pretreatment with the iPLA(2)-selective inhibitor bromoenol lactone. Thus stimulation of PAR-1 or PAR-2 on HUR leads to iPLA(2)-catalyzed phospholipid hydrolysis, resulting in the production of metabolites that may mediate inflammation or provide cytoprotection to the bladder.

Mast cell activation triggers a urothelial inflammatory response mediated by tumor necrosis factor-alpha

PURPOSE

Mast cells have been implicated in bladder inflammation and pathogenesis. To determine if mast cell secretion products can modulate urothelial inflammatory responses we developed an in vitro model of mast cell-urothelial cell interactions.

MATERIALS AND METHODS

Cultures of the immortalized urothelial cell line TEU-2 were incubated in the conditioned medium of mast cell cultures. The urothelial inflammatory response to mast cell secretion products was then determined by quantifying nuclear factor kappaB activity, the expression of endogenous nuclear factor kappaB dependent genes and the protein expression of inflammation markers.

RESULTS

Conditioned medium from RBL-2H3 mast cells induced a 4-fold increase in TEU-2 nuclear factor kappaB activity that was independent of the activation state of the mast cells. In contrast, ribonuclease protection assays revealed that the nuclear factor kappaB dependent transcripts tumor necrosis factor-alpha (TNF-alpha), interleukin (IL) 8 and 1beta, and intracellular adhesion molecule 1 (ICAM-1) were induced by mast cell conditioned medium in a manner that strictly depended on mast cell activation (antigen challenge of IgE sensitized RBL-2H3 cells). The dependence on mast cell activation was confirmed by the observation that IL-8 secretion and ICAM-1 protein expression in TEU-2 cultures were induced only by conditioned medium of stimulated RBL-2H3 cells The induction of TEU-2 IL-8 secretion and ICAM-1 expression by mast cell conditioned medium could be blocked by an anti-TNF-alpha antibody or the cysteine protease inhibitor N-acetyl-leucinyl-leucinyl-norleucinal.

CONCLUSIONS

Our data support the hypothesis that mast cells may participate in bladder inflammation. Furthermore, TNF-alpha acting via the nuclear factor kappaB signaling pathway may be a mediator of the urothelial response to mast cell secretion products.

Sodium pentosan polysulfate reduces urothelial responses to inflammatory stimuli via an indirect mechanism

PURPOSE

Sodium pentosan polysulfate has been promoted as a urothelial cytoprotective agent for treating interstitial cystitis. The nuclear transcription factor nuclear factor kappaB is thought to have a role in mediating the urothelial inflammatory response of interstitial cystitis. We further defined a possible cytoprotective effect of sodium pentosan polysulfate by characterizing the effect of the drug on the expression of nuclear factor kappaB.

MATERIALS AND METHODS

For cell culture human urothelial cells were incubated in various concentrations of sodium pentosan polysulfate for 16 hours in keratinocyte serum-free medium. They were subsequently treated with the known nuclear factor kappaB stimulants tumor necrosis factor-alpha, lipopolysaccaride (LPS) and double-stranded RNA (dsRNA). Each stimulant was then incubated with sodium pentosan polysulfate separately and the mixture was used to treat cultured urothelial cells. For electrophoretic mobility shift assay total cell extracts were prepared and run in electrophoretic mobility shift assays using a radiolabeled nuclear factor kappaB consensus sequence as a probe. Western blot analysis was done to assess nuclear factor kappaB activation by measuring degradation of the inhibitory subunit of the nuclear factor kappaB complex.

RESULTS

Nuclear factor kappaB activation by tumor necrosis factor-alpha, LPS and dsRNA was unaltered when cultured cells were incubated in sodium pentosan polysulfate before treatment. In contrast, nuclear factor kappaB activation by LPS and dsRNA was suppressed when the stimulants were incubated with sodium pentosan polysulfate before cell treatment. This suppressive effect was confirmed by Western blot analysis.

CONCLUSION

Sodium pentosan polysulfate may have a nonspecific effect against the viral (dsRNA) and bacterial (LPS) activation of nuclear factor kappaB. The observed clinical effect of sodium pentosan polysulfate may be mediated by nonspecific binding of sodium pentosan polysulfate molecules and the inflammatory stimulants of urothelial activation. These findings suggest a mechanism of action for sodium pentosan polysulfate that occurs in the urine rather than at the mucosal membrane by direct interaction of the drug with potential interstitial cystitis inducing inflammatory agents.

Modulation of IFN-gamma-induced immunogenicity by phosphatidylethanolamine-linked hyaluronic acid

BACKGROUND

The present study was conducted to examine the possibility of modulating interferon (IFN-gamma)-induced immunogenicity by a novel compound that is composed of a PLA2 inhibitor linked to hyaluronic acid (HYPE).

METHODS

HYPE was tested for its effect on IFN-gamma-induced expression of MHC class I, class II, and intercellular adhesion molecule (ICAM-1) in cultured endothelial and renal proximal tubular cells by flow cytometric analysis (FACS) as well as its ability to influence T cell activation in mixed lymphocyte reaction (MLR) or after mitogen stimulation.

RESULTS

In FACS, a profound inhibition in MHC class I and ICAM-1 staining was observed in stimulated or unstimulated cells that were incubated with HYPE. This was not due to down-regulation of antigen expression and only occurred when monoclonal antibodies, but not when polyclonal antibodies, were used. HYPE inhibited the induction of MHC class II in both cell types after IFN-gamma stimulation in a dose-dependent manner. Moreover, the induction of class II transactivator (CIITA) was completely inhibited under these conditions, most likely because it blocked the binding of IFN-gamma to the cell membrane. Addition of HYPE to MLR inhibited the proliferation of T cells and the secretion of interleukin (IL)-2, IFN-gamma, and IL-10. This was not observed when HYPE was added together with anti-CD3 or phytohemagglutinin (PHA).

CONCLUSION

Our study provides experimental evidence that HYPE has immunosuppressive features. This makes the compound an interesting candidate as an immunosuppressive drug, not only in organ transplantation, but also in diseases where IFN-gamma is overexpressed.

LPS-sensory peptide communication in experimental cystitis

Stimulation of sensory nerves can lead to release of peptides such as substance P (SP) and consequently to neurogenic inflammation. We studied the role of bacterial lipopolysaccharide (LPS) in regulating SP-induced inflammation. Experimental cystitis was induced in female mice by intravesical instillation of SP, LPS, or fluorescein-labeled LPS. Uptake of fluorescein-labeled LPS was determined by confocal analysis, and bladder inflammation was determined by morphological analysis. SP was infused into the bladders of some mice 24 h after exposure to LPS. In vitro studies determined the capacity of LPS and SP to induce histamine and cytokine release by the bladder. LPS was taken up by urothelial cells and distributed systemically. Twenty-four hours after instillation of LPS or SP, bladder inflammation was characterized by edema and leukocytic infiltration of the bladder wall. LPS pretreatment enhanced neutrophil infiltration induced by SP, increased in vitro release of histamine, tumor necrosis factor-alpha, and interferon-gamma, and significantly reduced transforming growth factor-beta1 release. These findings suggest that LPS amplifies neurogenic inflammation, thereby playing a role in the pathogenesis of neurogenic cystitis.

Distribution of lymphocytes of the alpha(E)beta(7) phenotype and E-cadherin in normal human urothelium and bladder carcinomas

The primary aim of this work was to survey normal urothelium and transitional cell carcinoma (TCC) for the presence of T lymphocytes expressing the intraepithelial, CD103(+) phenotype. This antigen defines the alpha(E)beta(7)-integrin. The adhesive counter-receptor for alpha(E)beta(7) is E-cadherin, which is down-regulated during cancer progression. The secondary aim was to determine the pattern of distribution of CD103(+) lymphocytes in relation to E-cadherin expression in bladder cancer. Cryostat sections of normal bladder and TCC were treated with antibodies specific for human CD103, CD3, CD8 and E-cadherin. Visualization was performed by immunoperoxidase or alkaline phosphatase development with light and confocal microscopy. Dual staining and serial sections were used to assess the relationship between these antigens. Four samples of normal bladder and 26 TCC samples were assessed. Occasional T lymphocytes (CD3(+)) were seen in normal urothelium and lamina propria. In the urothelium the majority of these T lymphocytes (71%) were also CD8(+) and of these 68% expressed the CD103 marker. In the lamina propria 62% of the T lymphocytes were CD8(+) and 56% of these expressed the CD103 marker. In carcinomas significantly greater numbers of CD103(+) T lymphocytes were present in the surrounding stroma rather than infiltrating the carcinomas (P = 0.0006). Of those T lymphocytes infiltrating the tumours, 71% were CD8(+) and of these 58% expressed CD103. In the surrounding stroma 52% of lymphocytes were CD8(+) and 82% of this subset expressed CD103. Infiltration by CD103(+) lymphocytes was not related to the intensity of E-cadherin expression. T lymphocytes of the CD103(+) phenotype are present in normal urothelium where they may play a role in immunosurveillance. Rather than infiltrating into carcinomas, these cells predominate in the surrounding stroma which could suggest a failure of immune function.

Tubules are the major site of M-CSF production in experimental kidney disease: correlation with local macrophage proliferation

BACKGROUND

Local proliferation of macrophages occurs within both the glomerulus and the interstitium in severe forms of human and experimental glomerulonephritis and plays an important role in amplifying renal injury. Macrophage colony-stimulating factor (M-CSF) is thought to be the growth factor driving this local macrophage proliferation. Previous studies have found that glomeruli are the predominant source of M-CSF production. However, this is difficult to reconcile with the prominent macrophage accumulation and proliferation seen in the interstitial compartment in glomerulonephritis. To address this issue, we localized M-CSF expression in rat models of glomerular versus tubulointerstitial injury and examined its relationship to local macrophage proliferation.

METHODS

M-CSF expression (Northern blotting, in situ hybridization, immunostaining, Western blotting) and local macrophage proliferation (double immunostaining) was examined in normal rat kidney on days 1 and 14 of rat anti-glomerular basement membrane (anti-GBM) glomerulonephritis and on day 5 following unilateral ureteric obstruction.

RESULTS

M-CSF mRNA and protein expression were identified in small numbers of glomerular podocytes, approximately 25% of cortical tubules, and most medullary tubules in normal rat kidney. Northern blotting showed a significant increase in whole kidney M-CSF mRNA in rat anti-GBM glomerulonephritis. Up-regulation of glomerular and, most prominently, tubular M-CSF production was confirmed by three independent methods: in situ hybridization, immunostaining, and Western blotting. The increase in M-CSF expression colocalized with local macrophage proliferation (ED1+PCNA+ cells) in both the glomerulus and tubulointerstitium. On day 5 after ureter ligation, there was a significant increase in tubular M-CSF mRNA and protein expression in the obstructed kidney, with no change in glomerular M-CSF. In parallel with M-CSF expression, macrophage accumulation and proliferation was prominent in the interstitium, but was absent from glomeruli.

CONCLUSIONS

The tubular epithelial cell is the major site of M-CSF production within the injured kidney. Indeed, substantial macrophage accumulation and local proliferation can occur in the tubulointerstitium in the absence of glomerular inflammation. These results suggest that M-CSF production within the kidney, particularly by tubular epithelial cells, plays an important role in regulating local macrophage proliferation in experimental kidney disease.

Prostate stem cell antigen is overexpressed in human transitional cell carcinoma

Prostate stem cell antigen (PSCA), a homologue of the Ly-6/Thy-1 family of cell surface antigens, is expressed by a majority of human prostate cancers and is a promising target for prostate cancer immunotherapy. In addition to its expression in normal and malignant prostate, we recently reported that PSCA is expressed at low levels in the transitional epithelium of normal bladder. In the present study, we compared the expression of PSCA in normal and malignant urothelial tissues to assess its potential as an immunotherapeutic target in transitional cell carcinoma (TCC). Immunohistochemical analysis of PSCA protein expression was performed on tissue sections from 32 normal bladder specimens, as well as 11 cases of low-grade transitional cell dysplasia, 21 cases of carcinoma in situ (CIS), 38 superficial transitional cell tumors (STCC, stages T(a)-T(1)), 65 muscle-invasive TCCs (ITCCs, stages T(2)-T(4)), and 7 bladder cancer metastases. The level of PSCA protein expression was scored semiquantitatively by assessing both the intensity and frequency (i.e., percentage of positive tumor cells) of staining. We also examined PSCA mRNA expression in a representative sample of normal and malignant human transitional cell tissues. In normal bladder, PSCA immunostaining was weak and confined almost exclusively to the superficial umbrella cell layer. Staining in CIS and STCC was more intense and uniform than that seen in normal bladder epithelium (P < 0.001), with staining detected in 21 (100%) of 21 cases of CIS and 37 (97%) of 38 superficial tumors. PSCA protein was also detected in 42 (65%) of 65 of muscle-invasive and 4 (57%) of 7 metastatic cancers, with the highest levels of PSCA expression (i.e., moderate-strong staining in >50% of tumor cells) seen in 32% of invasive and 43% of metastatic samples. Higher levels of PSCA expression correlated with increasing tumor grade for both STCCs and ITCCs (P < 0.001). Northern blot analysis confirmed the immunohistochemical data, showing a dramatic increase in PSCA mRNA expression in two of five muscle-invasive transitional cell tumors when compared with normal samples. Confocal microscopy demonstrated that PSCA expression in TCC is confined to the cell surface. These data demonstrate that PSCA is overexpressed in a majority of human TCCs, particularly CIS and superficial tumors, and may be a useful target for bladder cancer diagnosis and therapy.

Neutrophil recruitment, chemokine receptors, and resistance to mucosal infection

Neutrophil migration to infected mucosal sites involves a series of complex interactions with molecules in the lamina propria and at the epithelial barrier. Much attention has focussed on the vascular compartment and endothelial cells, but less is known about the molecular determinants of neutrophil behavior in the periphery. We have studied urinary tract infections (UTIs) to determine the events that initiate neutrophil recruitment and interactions of the recruited neutrophils with the mucosal barrier. Bacteria activate a chemokine response in uroepithelial cells, and the chemokine repertoire depends on the bacterial virulence factors and on the specific signaling pathways that they activate. In addition, epithelial chemokine receptor expression is enhanced. Interleukin (IL)-8 and CXCR1 direct neutrophil migration across the epithelial barrier into the lumen. Indeed, mIL-8Rh knockout mice showed impaired transepithelial neutrophil migration, with tissue accumulation of neutrophils, and these mice developed renal scarring. They had a defective antibacterial defense and developed acute pyelonephritis with bacteremia. Low CXCR1 expression was also detected in children with acute pyelonephritis. These results demonstrate that chemokines and chemokine receptors are essential to orchestrate a functional antimicrobial defense of the urinary tract mucosa. Mutational inactivation of the IL-8R caused both acute disease and chronic tissue damage.

Immunoglobulins in the human male genitourinary tract

Human male genitourinary tract was processed for the immunohistochemical demonstration of IgG and IgM, in order to verify the presence and the source of these immunoglobulins. Only the epithelia of the prostate gland and urethra showed a marked IgM-immunopositivity, localized in the cytoplasm of apical cells. An intense immunoreactivity for IgG was observed in the apical cells of the vesical epithelium; a less intense immunoreactivity for IgG in the pelvic apical epithelial cells was found. Immunostaining in the ureteric epithelium was absent. Clusters of IgM- and IgG-positive immunocompetent cells were present in the subepithelial layers of the organs observed in our study. This study indicates that IgM, present in mucosal surfaces, derived from an active secretion, as well as secretory IgA, whereas most of the IgG present in the human seminal plasma were probably due to transudation process. Immunoreactivity for IgG in the vesical and pelvic epithelia could depend upon to virus-specific IgG antibodies produced by the mucosa. This in turn can contribute to the total antiviral activity in mucosal secretions.

T-cell anergy: a consequence of interaction between T cells and allogeneic rat renal epithelial cells

In order to study the immunogenicity of parenchymal cells within an allograft, renal tubular cells were propagated from both PVG and DA strain rats. These cells were induced to express class II major histocompatibility (MHC) antigens by stimulation for 4 days with interferon-gamma (IFN-gamma). It was found that resting lymphoid cells derived from Lewis rats responded vigorously after stimulation with irradiated splenic cells from PVG rats. However, stimulation with renal cells from PVG rats did not result in interleukin (IL-2) production or lymphoproliferation. Furthermore, lymphocytes from this mixture failed to respond to secondary stimulation by PVG splenic cells; lymphocytes primed by mixture with DA renal cells responded normally to secondary stimulation by PVG splenic cells. These results indicate that renal epithelial cells can specifically anergise allogeneic lymphocytes.

Secretion of cytokines by uroepithelial cells stimulated by Escherichia coli and Citrobacter spp

Urinary tract epithelial cells (T 24/83) are able to express interleukin (IL)-6, IL-8, platelet-derived growth factor (PDGF) and tumour necrosis factor-alpha, but not IL-1 beta, IL-2, IL-4 and IL-10 in response to an infection with uropathogenic bacteria. The process of cytokine secretion is time dependent, with a significant increase in the cytokine activity after 60 min. The expression of virulence factors of the bacteria does not seem to play a role. The interaction between bacterial products (e.g. lipopolysaccharide) and/or bacterial adhesion mediated by adhesins and specific receptor molecules of cell surfaces may be responsible for the activity of mediator protein expression in the epithelial cells. The release of PDGF and IL-8 was found to be higher when due to Escherichia coli HB 101 (rough form) than that caused by other bacterial strains. Citrobacter CB 3009 provoked the highest level of IL-6. The PDGF level correlated significantly with IL-6 and IL-8 values (P<0.001). There was a significant correlation between the time-dependent release of IL-6 and IL-8 (P<0.05). In epithelial cytokine response to bacterial infection, the reaction of the epithelial cells may modify themselves (e.g. internalization of bacteria) and the immuno-regulatory processes that are caused by infection and responsible for parenchymal injury.