Re: Pentosan polysulfate and a pigmentary maculopathy: causation versus correlation?

How should a conscientious physician advise patients with Interstitial Cystitis /Bladder Pain Syndrome (IC/BPS) when they want to know if taking Pentosan Polysulfate Sodium (PPS) will lead to loss of vision? Ever since the initial report from Pearce et al in 2018 suggesting that PPS usage can lead to the development of pigmented maculopathy (PM), my patients have been inundated with solicitations from attorneys looking to sign up clients for class action lawsuits.1 While there have been additional reports suggesting a relationship between PPS exposure and the development of PM, Ludwig et al found that there was no difference in the rate of macular disease between patients with documented IC/BPS who had taken PPS and those with IC/BPS with no history of PPS use.2 The large size of Ludwig's study certainly suggests that PPS may not cause PM to develop, and if the rate of PM in the IC population is higher than in controls, it may be due to the disease itself and not from the medication. In this manuscript, Proctor clearly describes the immune inflammatory response that is responsible for the development of the bladder damage seen with IC/BPS. Also, he describes how inflammatory mediators can enter the blood stream and might be a potential cause for the development of PM.3 This is a thought-provoking hypothesis that demands further evaluation. I have prescribed PPS since its approval and have many patients who feel it is an essential part of their IC treatment regimen. There is no other prescription medication that functions in the same fashion. I require them to follow the FDA recommendations for annual eye exams to look for PM development. I also advise patients that as they improve, we will discuss dose reduction and even discontinuation if their IC symptoms have abated. By following these suggestions, one should be able to continue to prescribe PPS for appropriate patients while carefully monitoring them for PM. I found this article extremely informative and will refer to it when counseling patients about IC/BPS and PPS.

Small-Fiber Polyneuropathy Is Prevalent in Patients With Interstitial Cystitis/Bladder Pain Syndrome

IMPORTANCE

The pathophysiology of interstitial cystitis/bladder pain syndrome (IC/BPS) is imperfectly understood. Recent studies reported that small-fiber polyneuropathy (SFPN) is common in fibromyalgia, a condition commonly comorbid with IC/BPS.

OBJECTIVE

The objective of this study was to determine the prevalence of SFPN in a large cohort of IC/BPS patients.

METHODS

Adults diagnosed with IC/BPS scheduled to undergo either therapeutic hydrodistention (n = 97) or cystectomy with urinary diversion (n = 3) were prospectively recruited to this study. A skin biopsy obtained from the lower leg was used for intraepidermal nerve fiber density measurement. Small-fiber polyneuropathy (+/-) status was determined by comparing linear intraepidermal nerve fiber density (fibers/mm2) with normative reference values. Demographic information, medical history, and diagnoses for 14 conditions (both urologic and nonurologic) known to co-occur with IC/BPS were documented from self-report and electronic medical record.

RESULTS

In this large cohort of patients with IC/BPS, 31% (31/100) were positive for SFPN. Intraepidermal nerve fiber density was below the median for age and sex in 81% (81/100) of patients. Approximately one-third (31%) of SFPN+ patients reported co-occurring chronic fatigue syndrome, compared with 10.6% of the SFPN- group (P = 0.034). Small-fiber polyneuropathy-positive patients reported significantly fewer allergies than SFPN- patients (37.9% vs 60.6%; P = 0.047). There were no significant differences in bladder capacity or Hunner lesion status between the SFPN+ and SFPN- subgroups.

CONCLUSIONS

Small-fiber polyneuropathy is a common finding in patients with IC/BPS, and SFPN status is significantly correlated with co-occurring chronic fatigue syndrome and negatively correlated with the presence of allergies in this population.

Pulsed Electromagnetic Field Therapy for Pain Management in Interstitial Cystitis/Bladder Pain Syndrome: A Proof-of-Concept Case Series

OBJECTIVE

To evaluate the efficacy of pulsed electromagnetic field (PEMF) therapy for symptom and pain management in women with non-bladder centric interstitial cystitis/bladder pain syndrome (IC/BPS).

METHODS

Women with non-bladder centric IC/BPS and a numeric rating scale score for pelvic pain ≥6 underwent twice-daily 8-minute full body PEMF therapy sessions for 4 weeks. The primary outcome metric was a reduction in pelvic pain score ≥2 points. A 7-day voiding diary (collected at baseline and conclusion), 3 validated symptom scores, and the Short Form-36 Quality of Life questionnaire (completed at baseline, conclusion of treatment, and 8-week follow-up), were used to assess secondary outcomes. Treatment effects were analyzed via Wilcoxon-signed rank test; P < .05 was considered significant.

RESULTS

The 4-week treatment protocol was completed by 8 of 10 enrolled patients, and 7:8 (87.5%) had a significant reduction in pelvic pain (-3.0 points, P = .011) after 4 weeks. There was also a significant decrease in scores on all validated IC/BPS questionnaires, daily number of voids, and nocturia symptom score (P < .05). Significant increases in several quality-of-life questionnaire sub-scores were also identified at 4 weeks (P < .05). At 8-week post-therapy, the positive effects were somewhat attenuated, yet 4:8 patients (50%) continued to have significant pain reduction (P = .047). No adverse events or side effects were reported.

CONCLUSION

Whole body pulsed electromagnetic field therapy is an alternative treatment option for women with chronic bladder pain syndrome that warrants investigation through comparative trials.

Blood vessel occlusion by Cryptococcus neoformans is a mechanism for haemorrhagic dissemination of infection

Meningitis caused by infectious pathogens is associated with vessel damage and infarct formation, however the physiological cause is often unknown. Cryptococcus neoformans is a human fungal pathogen and causative agent of cryptococcal meningitis, where vascular events are observed in up to 30% of patients, predominantly in severe infection. Therefore, we aimed to investigate how infection may lead to vessel damage and associated pathogen dissemination using a zebrafish model that permitted noninvasive in vivo imaging. We find that cryptococcal cells become trapped within the vasculature (dependent on their size) and proliferate there resulting in vasodilation. Localised cryptococcal growth, originating from a small number of cryptococcal cells in the vasculature was associated with sites of dissemination and simultaneously with loss of blood vessel integrity. Using a cell-cell junction tension reporter we identified dissemination from intact blood vessels and where vessel rupture occurred. Finally, we manipulated blood vessel tension via cell junctions and found increased tension resulted in increased dissemination. Our data suggest that global vascular vasodilation occurs following infection, resulting in increased vessel tension which subsequently increases dissemination events, representing a positive feedback loop. Thus, we identify a mechanism for blood vessel damage during cryptococcal infection that may represent a cause of vascular damage and cortical infarction during cryptococcal meningitis.

Meningitis is a life threatening form of infection in the brain that is difficult to treat. How infection spreads from the blood to cause meningitis is not well understood. Here we have shown how infection with the fungus Cryptococcus neoformans can be spread from the blood by blocking and bursting blood vessels. Using zebrafish larvae, we were able to follow the same infections over a period of days to understand how this infection behaves in blood vessels. We found that fungal cells become stuck within blood vessels depending on their size. These cells grow within blood vessels, resulting in the blood vessels becoming wider. We measured increased tension in blood vessels suggesting that, with the bloackage and widening of vessels, there was increased local blood pressure. We found that vessel blockage was associated with their rupture and spreading of fungus into the surround tissue. Finally, by increasing the tension in vessels we could increase the number of blood bursting events supporting our conclusion that blood vessel blockage leads to the spread of the infection outside of blood vessels.

Functional genomic analyses of IC/BPS patient subgroups: a pilot study

INTRODUCTION

To further facilitate understanding of disease pathophysiology and patient stratification in interstitial cystitis/bladder pain syndrome (IC/BPS), we utilized molecular phenotyping to compare three clinically distinct IC/BPS patient subgroups.

MATERIALS AND METHODS

Total RNA (miRNA and mRNA) was isolated via standard protocols from IC/BPS patient bladder biopsies and assayed on whole genome and microRNA expression arrays. Data from three patient subgroups (n = 4 per group): (1) low bladder capacity (BC; ≤ 400 cc) without Hunner's lesion, (2) low BC with Hunner's lesion, and (3) non-low BC (> 400 cc) were used in comparative analyses to evaluate the influence of BC and HL on gene expression profiles in IC/BPS.

RESULTS

The BC comparison (Group 1 v 3) identified 54 miRNAs and 744 mRNAs. Eleven miRNAs mapped to 40 genes. Hierarchical clustering of miRNA revealed two primary clusters: (1) 3/4 low BC patients; (2) 4/4 non-low and 1/4 low BC patients. Clustering of mRNA provided clear separation based on BC. The HL comparison (Group 1 v 2) identified 16 miRNAs and 917 mRNAs. 4 miRNAs mapped to 13 genes. Clustering of miRNA and mRNA revealed clear separation based on HL status.

CONCLUSIONS

Significant molecular differences in IC/BPS were found to be associated with the low BC phenotype (e.g., an upregulation of cell proliferation and inflammation marker genes), as well as additional molecular findings that further define the HL+ phenotype (e.g., upregulation of genes involved in bioenergetics reactions) and suggest oxidative stress may play a role.

Anesthetic Bladder Capacity is a Clinical Biomarker for Interstitial Cystitis/Bladder Pain Syndrome Subtypes

OBJECTIVE

To further examine anesthetic bladder capacity as a biomarker for interstitial cystitis/bladder pain syndrome (IC/BPS) patient subtypes, we evaluated demographic and clinical characteristics in a large and heterogeneous female patient cohort.

MATERIAL AND METHODS

This is a retrospective review of data from women (n = 257) diagnosed with IC/BPS who were undergoing therapeutic bladder hydrodistention (HOD). Assessments included medical history and physical examination, validated questionnaire scores, and anesthetic BC. Linear regression analyses were computed to model the relationship between anesthetic BC and patient demographic data, symptoms, and diagnoses. Variables exhibiting suggestive correlations (P ≤ .1) were candidates for a multiple linear regression analysis and were retained if significant (P ≤ .05).

RESULTS

Multiple regression analysis identified a positive correlation between BC and endometriosis (P = .028) as well as negative correlations between BC and both ICSI score (P < .001) and the presence of Hunner's lesions (P < .001). There were higher average numbers of pelvic pain syndrome (PPS) diagnoses (P = .006) and neurologic, autoimmune, or systemic pain (NASP) diagnoses (P = .003) in IC/BPS patients with a non-low BC, but no statistical difference in the duration of diagnosis between patients with low and non-low BC (P = .118).

CONCLUSION

These data, generated from a large IC/BPS patient cohort, provide additional evidence that higher BC correlates with higher numbers of non-bladder-centric syndromes while lower BC correlates more closely with bladder-specific pathology. Taken together, the results support the concept of clinical subgroups in IC/BPS.

Vaccinia virus hijacks ESCRT-mediated multivesicular body formation for virus egress

Poxvirus extracellular virions are critical for virus virulence. This study shows that multivesicular bodies serve as a major cellular source of membrane for their formation and spread.

Poxvirus egress is a complex process whereby cytoplasmic single membrane–bound virions are wrapped in a cell-derived double membrane. These triple-membrane particles, termed intracellular enveloped virions (IEVs), are released from infected cells by fusion. Whereas the wrapping double membrane is thought to be derived from virus-modified trans-Golgi or early endosomal cisternae, the cellular factors that regulate virus wrapping remain largely undefined. To identify cell factors required for this process the prototypic poxvirus, vaccinia virus (VACV), was subjected to an RNAi screen directed against cellular membrane-trafficking proteins. Focusing on the endosomal sorting complexes required for transport (ESCRT), we demonstrate that ESCRT-III and VPS4 are required for packaging of virus into multivesicular bodies (MVBs). EM-based characterization of MVB-IEVs showed that they account for half of IEV production indicating that MVBs are a second major source of VACV wrapping membrane. These data support a model whereby, in addition to cisternae-based wrapping, VACV hijacks ESCRT-mediated MVB formation to facilitate virus egress and spread.

Pulsed electromagnetic field (PEMF) as an adjunct therapy for pain management in interstitial cystitis/bladder pain syndrome

INTRODUCTION AND HYPOTHESIS

Patients with interstitial cystitis/bladder pain syndrome (IC/BPS) often experience chronic pelvic and even systemic pain that can be difficult to clinically manage. Pulsed electromagnetic field (PEMF) therapy, a non-invasive strategy that has shown significant efficacy for pain reduction in other chronic pain conditions, may provide benefit for pain management in patients with IC/BPS.

METHODS

PEMF delivery to patients occurs via a bio-electromagnetic-energy device which consists of a flexible mat (180 × 50 cm) that the patient lies on for systemic, full-body delivery and/or a flexible pad (50 × 15 cm) for targeted delivery to a specific body region (e.g., pelvic area). The duration of individual sessions, number of sessions per day, total number of sessions, and follow-up observation period vary between previously published studies. Positive outcomes are typically reported as a significant reduction in visual analog scale (VAS) pain score and functional improvement assessed using validated questionnaires specific to the condition under study.

RESULTS AND CONCLUSIONS

The use of PEMF has been evaluated as a therapeutic strategy for pain management in several clinical scenarios. Randomized, double-blinded, placebo-controlled trials have reported positive efficacy and safety profiles when PEMF was used to treat non-specific low back pain, patellofemoral pain syndrome, chronic post-operative pain, osteoarthritis-related pain, rheumatoid arthritis-related pain, and fibromyalgia-related pain. Based on these positive outcomes in a variety of pain conditions, clinical trials to evaluate whether PEMF can provide a safe, non-invasive therapeutic approach to improve symptoms of chronic pain and fatigue in patients with IC/BPS are warranted.

Hydrodistention does not alter bladder gene expression profiles in patients with non-Hunner lesion interstitial cystitis/bladder pain syndrome

AIMS

Gene expression profiling of bladder biopsies in patients with interstitial cystitis/bladder pain syndrome (IC/BPS), typically obtained following therapeutic bladder hydrodistention (HOD), is used to improve our understanding of molecular phenotypes. The objective of this study was to determine if the HOD procedure itself impacts the biopsy gene expression profile and, by extension, whether biopsies from non-HOD bladders are appropriate controls.

METHODS

Bladder biopsies were obtained just before HOD and immediately following HOD from 10 consecutively recruited IC/BPS patients undergoing therapeutic HOD. Biopsies were also obtained from four non-IC/BPS patients who did not undergo HOD (controls). Total RNA was isolated from each of the 24 samples and used to query whole-genome microarrays. Differential gene expression analysis was performed to compare expression profiles of IC/BPS biopsies before and after HOD, and between IC/BPS and control biopsies.

RESULTS

Principal component analysis revealed complete separation between gene expression profiles from IC/BPS and control samples (q ≤ 0.05) and while IC/BPS samples before and after HOD showed no significant differences in expressed genes, 68 transcripts were found to be significantly different between IC/BPS and control samples (q ≤ 0.05).

CONCLUSIONS

The bladder HOD procedure itself does not significantly change gene expression within the IC/BPS patient bladder, a finding that provides evidence to support the use of biopsies from non-IC/BPS patients that have not undergone HOD as controls for gene expression studies.

Correction: 15-keto-prostaglandin E2 activates host peroxisome proliferator-activated receptor gamma (PPAR-γ) to promote Cryptococcus neoformans growth during infection

[This corrects the article DOI: 10.1371/journal.ppat.1007597.].

Role of urinary cations in the etiology of interstitial cystitis: A multisite study

OBJECTIVE

To determine whether patients with interstitial cystitis have elevated levels of toxic urinary cations, to identify and quantify these cationic metabolites, and to assess their cytotoxicity.

METHODS

Isolation of cationic fraction was achieved by solid phase extraction using an Oasis MCX cartridge on urine specimens from interstitial cystitis patients and controls. C₁₈ reverse phase high-performance liquid chromatography was used to profile cationic metabolites, and they were quantified by the area under the peaks and normalized to creatinine. Major cationic fraction peaks were identified by reverse phase high-performance liquid chromatography and liquid chromatography-mass spectrometry. HTB-4 urothelial cells were used to determine the cytotoxicity of cationic fraction and of individual metabolites.

RESULTS

The reverse phase high-performance liquid chromatography analysis was carried out on cationic fraction metabolites isolated from urine samples of 70 interstitial cystitis patients and 34 controls. The mean for controls versus patients was 3.84 (standard error of the mean 0.20) versus 6.71 (0.37) mAU*min/µg creatinine, respectively (P = 0.0001). The cationic fraction cytotoxicity normalized to creatinine for controls versus patients in mean percentage was -7.79% (standard error of the mean 3.32%) versus 20.03% (standard error of the mean 2.75%; P < 0.0005). The major toxic cations were 1-methyladenosine, 1-methylguanine, N² ,N² -dimethylguanosine and L-tryptophan.

CONCLUSIONS

These data confirm significant elevation of toxic cations in the urine of interstitial cystitis patients. These toxic cations likely represent a primary cause of interstitial cystitis, as they can injure the bladder mucus and initiate an epithelial leak.

Non-bladder centric interstitial cystitis/bladder pain syndrome phenotype is significantly associated with co-occurring endometriosis

INTRODUCTION

Interstitial cystitis/bladder pain syndrome (IC/BPS) and endometriosis are coexistent diagnoses in 48%-65% of women with chronic pelvic pain (CPP), suggesting that dual screening may be warranted. To further investigate the clinical relationship and risk factors between these two conditions, we performed a retrospective review of our large IC/BPS patient data registry.

MATERIALS AND METHODS

We evaluated IC/BPS patients who were prospectively enrolled into our registry who completed validated questionnaires and underwent therapeutic hydrodistension, during which anesthetic bladder capacity (BC) and Hunner's lesion (HL) status were recorded. Demographic/medical history were reviewed. IC/BPS patients with co-occurring endometriosis diagnosis versus those without were compared using descriptive statistics as well as multivariate regression analyses to determine predictors of co-occurring disease.

RESULTS

Of 431 IC/BPS participants, 82 (19%) were also diagnosed with endometriosis. These women were significantly younger, had increased prevalence of non-low BC (> 400 cc), and decreased prevalence of HL (p < 0.05). Patients with co-occurring endometriosis also had increased prevalence of irritable bowel syndrome (IBS), CPP, fibromyalgia, and vulvodynia (p < 0.05). On multivariate analysis, non-low BC (OR 4.53, CI 1.004-20.42, p = 0.049), CPP (OR 1.84, CI 1.04-3.24, p = 0.04), and fibromyalgia (OR 1.80, CI 1.03-3.14, p < 0.04) were significantly associated with a diagnosis of endometriosis.

CONCLUSIONS

Patients with IC/BPS and co-occurring endometriosis were significantly more likely to carry a non-bladder centric IC/BPS phenotype as well as several comorbid, systemic pain diagnoses. This study characterizes features of a target IC/BPS phenotype that could potentially benefit from endometriosis and systemic pain syndrome screening.

Injection location does not impact botulinum toxin A efficacy in interstitial cystitis/bladder pain syndrome patients

INTRODUCTION

Botulinum toxin A (BTX-A) is currently used as a fourth-line therapeutic option for interstitial cystitis/bladder pain syndrome (IC/BPS) management. The purpose of this study was to determine if BTX-A injection can mitigate pain and if injection location (i.e. trigone-including versus trigone-sparing injection template) impacts treatment efficacy and/or treatment complications profile.

MATERIALS AND METHODS

Female IC/BPS patients refractory to conservative management strategies were prospectively enrolled and asked to complete a baseline history and physical exam, post-void residual (PVR) urine volume determination, O'Leary Sant (OLS) questionnaire, and Pelvic Pain and Urgency/Frequency Symptom Scale (PUF) questionnaire. Participants were randomly assigned to one of two treatment groups and received either: 1) a trigone-including BTX-A injection template or 2) a trigone-sparing injection template. Following therapy, patients were examined in clinic at 30 and 90 day post-treatment with symptom re-assessment via repeat questionnaires and for evidence of post-procedural complications.

RESULTS

Compared to baseline, patients in both treatment groups experienced significant improvement in OLS and PUF scores at both 30 and 90 days post-treatment with BTX-A, regardless of which injection template was used (p < 0.05). Complications resulting from BTX-A were minimal (most commonly urinary tract infection (UTI) and urinary retention) and not significantly different between the treatment groups (p > 0.05). No distant spread of BTX-A was observed in any patient in either treatment group.

CONCLUSIONS

BTX-A treatment using either a trigone-sparing or trigone-including injection template resulted in significant, but not location-dependent, improvement in IC/BPS symptom scores at 30 and 90 day points post-procedure with no significant difference in post-treatment complication profiles.

PPAR-gamma Fun(gi) With Prostaglandin

In our recent publication, we show for the first time that the fungal pathogen Cryptococcus neoformans is able to manipulate host cells by producing eicosanoids that mimic those found in the host. Using complementary in vivo zebrafish and in vitro macrophage cell culture models of Cryptococcus infection, we found that these eicosanoids manipulate host innate immune cells by activating the host receptor PPAR-gamma which is an important regulator of macrophage inflammatory phenotypes. We initially identified PGE2 as the eicosanoid species responsible for this effect; however, we later found that a derivative of PGE2—15-keto-PGE₂—was ultimately responsible and that this eicosanoid acted as a partial agonist to PPAR-gamma. In this commentary, we will discuss some of the concepts and conclusions in our original publication and expand on their implications and future directions.

Bladder Hydrodistention Does Not Result in a Significant Change in Bladder Capacity for Interstitial Cystitis/Bladder Pain Syndrome Patients

OBJECTIVE

To assess the impact of multiple (2 or more) bladder hydrodistentions (HODs) on anesthetic bladder capacity (BC) in a large cohort of interstitial cystitis/bladder pain syndrome (IC/BPS) patients. Urinary HOD under anesthesia is a third line therapeutic approach used to treat patients with IC/BPS. There is some concern that performing multiple therapeutic HODs may be contraindicated due to the potential for contributing to a diminished BC over time.

MATERIALS AND METHODS

This is a retrospective chart review of IC/BPS patients from a single institution who had undergone 2 or more bladder HOD procedures. Patient demographic and clinical data, including BC under anesthesia, were retrieved from patient charts for analysis. Least squares regression slopes of BC under anesthesia were calculated and used to estimate within-patient BC changes over time.

RESULTS

Data from 168 patients (637 HOD procedures) were included for analysis. The average change in BC, 0.52 ± 8.33 mL/mo, was not significantly different from 0 (P= .42). Linear regression analyses did not identify any significant correlation between BC over time with: (1) age, (2) number of HODs, (3) frequency of HODs, (4) average BC, (5) length of time with an IC/BPS diagnosis, or (6) length of time during which the patient's BC was evaluated. Moreover, there was no difference in BC change over time in patients with and without Hunner's lesion (P = .86).

CONCLUSION

Multiple therapeutic HODs, over several years, do not result in a significant change in BC in IC/BPS patients.

Small fiber polyneuropathy as a potential therapeutic target in interstitial cystitis/bladder pain syndrome

INTRODUCTION AND HYPOTHESIS

Interstitial cystitis/bladder pain syndrome (IC/BPS) and fibromyalgia (FM) are frequently co-occurring medical diagnoses in patients referred to the urology clinic for secondary and tertiary treatment options.

METHODS

Abundant literature has shown that many patients with FM have small fiber polyneuropathy (SFPN) that can be confirmed via skin punch biopsy and immunological staining to measure nerve density.

RESULTS AND CONCLUSIONS

This finding of SFPN provides a therapeutic target for FM and in this article we hypothesize and provide rationale for the idea that this same phenomenon (SFPN) might explain, in some IC/BPS patients, the finding of widespread pain and likewise provide a therapeutic target for these patients.

15-keto-prostaglandin E2 activates host peroxisome proliferator-activated receptor gamma (PPAR-γ) to promote Cryptococcus neoformans growth during infection

Cryptococcus neoformans is one of the leading causes of invasive fungal infection in humans worldwide. C. neoformans uses macrophages as a proliferative niche to increase infective burden and avoid immune surveillance. However, the specific mechanisms by which C. neoformans manipulates host immunity to promote its growth during infection remain ill-defined. Here we demonstrate that eicosanoid lipid mediators manipulated and/or produced by C. neoformans play a key role in regulating pathogenesis. C. neoformans is known to secrete several eicosanoids that are highly similar to those found in vertebrate hosts. Using eicosanoid deficient cryptococcal mutants Δplb1 and Δlac1, we demonstrate that prostaglandin E₂ is required by C. neoformans for proliferation within macrophages and in vivo during infection. Genetic and pharmacological disruption of host PGE₂ synthesis is not required for promotion of cryptococcal growth by eicosanoid production. We find that PGE₂ must be dehydrogenated into 15-keto-PGE₂ to promote fungal growth, a finding that implicated the host nuclear receptor PPAR-γ. C. neoformans infection of macrophages activates host PPAR-γ and its inhibition is sufficient to abrogate the effect of 15-keto-PGE₂ in promoting fungal growth during infection. Thus, we describe the first mechanism of reliance on pathogen-derived eicosanoids in fungal pathogenesis and the specific role of 15-keto-PGE₂ and host PPAR-γ in cryptococcosis.

Cryptococcus neoformans is an opportunistic fungal pathogen that is responsible for significant numbers of deaths in the immunocompromised population worldwide. Here we address whether eicosanoids produced by C. neoformans manipulate host innate immune cells during infection. Cryptococcus neoformans produces several eicosanoids that are notable for their similarity to vertebrate eicosanoids, it is therefore possible that fungal-derived eicosanoids may provoke physiological effects in the host. Using a combination of in vitro and in vivo infection models we identify a specific eicosanoid species—prostaglandin E2 –that is required by C. neoformans for growth during infection. We subsequently show that prostaglandin E₂ must be converted to 15-keto-prostaglandin E₂ within the host before it has these effects. Furthermore, we find that prostaglandin E₂/15-keto-prostaglandin E₂ mediated virulence is via activation of host PPAR-γ –an intracellular eicosanoid receptor known to interact with 15-keto-PGE₂.

The Interplay of Host Autophagy and Eukaryotic Pathogens

For intracellular pathogens, host cells provide a replicative niche, but are also armed with innate defense mechanisms to combat the intruder. Co-evolution of host and pathogens has produced a complex interplay of host-pathogen interactions during infection, with autophagy emerging as a key player in the recent years. Host autophagy as a degradative process is a significant hindrance to intracellular growth of the pathogens, but also can be subverted by the pathogens to provide support such as nutrients. While the role of host cell autophagy in the pathogenesis mechanisms of several bacterial and viral pathogens have been extensively studied, less is known for eukaryotic pathogens. In this review, we focus on the interplay of host autophagy with the eukaryotic pathogens Plasmodium spp, Toxoplasma, Leishmania spp and the fungal pathogens Candida albicans, Aspergillus fumigatus and Cryptococcus neoformans. The differences between these eukaryotic pathogens in terms of the host cell types they infect, infective strategies and the host responses required to defend against them provide an interesting insight into how they respond to and interact with host cell autophagy. Due to the ability to infect multiple host species and cell types during the course of their usually complex lifestyles, autophagy plays divergent roles even for the same pathogen. The scenario is further compounded since many of the eukaryotic pathogens have their own sets of either complete or partial autophagy machinery. Eukaryotic pathogen-autophagy interplay is thus a complex relationship with many novel insights for the basic understanding of autophagy, and potential for clinical relevance.

A transgenic zebrafish model for the in vivo study of the blood and choroid plexus brain barriers using claudin 5

The central nervous system (CNS) has specific barriers that protect the brain from potential threats and tightly regulate molecular transport. Despite the critical functions of the CNS barriers, the mechanisms underlying their development and function are not well understood, and there are very limited experimental models for their study. Claudin 5 is a tight junction protein required for blood brain barrier (BBB) and, probably, choroid plexus (CP) structure and function in vertebrates. Here, we show that the gene claudin 5a is the zebrafish orthologue with high fidelity expression, in the BBB and CP barriers, that demonstrates the conservation of the BBB and CP between humans and zebrafish. Expression of claudin 5a correlates with developmental tightening of the BBB and is restricted to a subset of the brain vasculature clearly delineating the BBB. We show that claudin 5a-expressing cells of the CP are ciliated ependymal cells that drive fluid flow in the brain ventricles. Finally, we find that CP development precedes BBB development and that claudin 5a expression occurs simultaneously with angiogenesis. Thus, our novel transgenic zebrafish represents an ideal model to study CNS barrier development and function, critical in understanding the mechanisms underlying CNS barrier function in health and disease.

Summary: A novel transgenic zebrafish, using claudin 5a, represents an ideal model to study blood brain barrier and choroid plexus barrier development and function in vivo.

Impact of Cystectomy With Urinary Diversion Upon Tracked Receipt of Opioid Prescriptions Among Patients With Interstitial Cystitis/Bladder Pain Syndrome

OBJECTIVE

To compare opioid requirements before and after cystectomy for end-stage Interstitial Cystitis/Bladder Pain Syndrome (IC/BPS) using a statewide tracking system.

METHODS

Narcotic prescriptions were captured using the North Carolina Controlled Substance Reporting System for patients at a single institute undergoing cystectomy with urinary diversion (CWUD) for refractory, end-stage IC/BPS between 2010 and 2017. Values were documented for the year before and the year after surgery (excluding 30 days postoperatively to account for surgical pain) and converted to morphine equivalents (ME). Values were compared using Student t test.

RESULTS

Following CWUD, there was a mean decrease in opioid receipt per patient of 6535 ME/year (P = .321). 8/26 (31%) had not filled any opiate prescriptions for the preceding 3 months at time of manuscript writing.

CONCLUSION

In certain patients with end-stage, refractory IC/BPS, CWUD can help reduce opioid requirements.

Abstract 519: Antitumor activity of MET antibody emibetuzumab (LY2875358) in combination with EGFR inhibitors in erlotinib resistant (ER) xenograft mouse models

Background: MET amplification (amp) is a resistance mechanism to EGFR TKI treatment. Emibetuzumab, a bivalent MET antibody (Ab) blocks HGF binding to MET and internalizes the receptor. Combination of emibetuzumab with EGFR TKIs (erlotinib, AZD9291, CO1686) or EGFR Ab (necitumumab, cetuximab) was evaluated in 3 ER xenograft models.

Methods: Model 1: ER cell line HCC827ERL with high focal MET amp, high pMET, EGFR ex19 del (no T790M) was created from parental HCC827 NSCLC (EGFR ex19 del, EGFR amp, no MET amp) by increasing concentration of erlotinib in vitro over 7 months. Model 2: ER cell line HCC827-A8 was derived from HCC827 parental xenograft tumor serially passed in vivo with long term treatment of gefitinib and erlotinib. HCC827-A8 cells express high focal MET amp, high pMET/AXL (Western blot) while retaining EGFR ex19 del (no T790M). Model 3: LU0858 was an ER patient-derived NSCLC xenograft tumor, with focal MET amp, EGFR L858R (no T790M). MET amp and EGFRmt was determined by FISH and LNA-PCR sequencing respectively. Compound dosing: emibetuzumab 20 mg/kg qw; necitumumab 4 mg/kg or 20 mg/kg biw; cetuximab 4 mg/kg biw; erlotinib 25 mg/kg qd; 5 mg/kg AZD9291 qd; 30 mg/kg CO1686 bid.

Results: EGFR inhibitors, but not emibetuzumab showed significant single agent anti-tumor effect in xenograft tumors derived from non-MET amp HCC827 parental cells. In MET amp ER models, single agent emibetuzumab resulted in tumor growth inhibition in Model 1 (T/C= 51.7%-61.0%, p&lt;0.05) and 3 (T/C=2.8%, p&lt;0.05)] but no tumor regression, and no anti-tumor effect in Model 2. Where evaluated, EGFR inhibitors showed no anti-tumor effect in the 3 ER models as monotherapy, except necitumumab (20 mg/kg) in Model 1 (T/C = 36.2%, p&lt;0.05). However, combination of emibetuzumab with AZD9291, CO1686, necitumumab (20 mg/kg), or erlotinib resulted in 80.4%, 58.2%, 44.4%, 69.1% tumor regression respectively (p&lt;0.001) in Model 1, while emibetuzumab + cetuximab (4 mg/kg) resulted in tumor stasis (T/C=0.2%, p&lt;0.05). In Model 2, emibetuzumab + AZD9291 resulted in tumor stasis (T/C = 12.9%, p&lt;0.05). In Model 3, emibetuzumab + necitumumab (20 mg/kg) resulted in 80.1% tumor regression (p&lt;0.001).

Conclusion: The three erlotinib resistant models with MET amp and retaining sensitizing EGFRmt (ex19 del or L858R), and no acquired T790M were found resistant to other EGFR inhibitors (Abs and TKIs). Emibetuzumab in combination with either EGFR TKI or Ab showed anti-tumor activity in MET amp ER xenograft models including tumor regression in 2 out of 3 models. The combination of emibetuzumab with erlotinib is being evaluated in NSCLC patients with EGFR activating mutation (NCT01897480).

Citation Format: Suzane L. Um, Victoria L. Peek, Jennifer R. Stephens, Jessica A. Baker, Holly K. Cannon, Joel D. Cook, Isabella H. Wulur, Roger Agyei, Sudhakar Chintharlapalli, Robert J. Evans, William J. Feaver, Lysiane Huber, Linda N. Lee, Ling Liu, Liandong Ma, Ruslan Novosiadly, Volker Wacheck, Sau-Chi Betty Yan. Antitumor activity of MET antibody emibetuzumab (LY2875358) in combination with EGFR inhibitors in erlotinib resistant (ER) xenograft mouse models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 519. doi:10.1158/1538-7445.AM2017-519

Application of DRIFTS, 13C NMR, and py-MBMS to Characterize the Effects of Soil Science Oxidation Assays on Soil Organic Matter Composition in a Mollic Xerofluvent

Chemical oxidations are routinely employed in soil science to study soil organic matter (SOM), and their interpretation could be improved by characterizing oxidation effects on SOM composition with spectroscopy. We investigated the effects of routinely employed oxidants on SOM composition in a Mollic Xerofluvent representative of intensively managed agricultural soils in the California Central Valley. Soil samples were subjected to oxidation by potassium permanganate (KMnO₄), sodium hypochlorite (NaOCl), and hydrogen peroxide (H₂O₂). Additionally, non-oxidized and oxidized soils were treated with hydrofluoric acid (HF) to evaluate reduction of the mineral component to improve spectroscopy of oxidation effects. Oxidized non-HF and HF-treated soils were characterized by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), ¹³C cross polarization magic angle spinning (CP-MAS) nuclear magnetic resonance (NMR) spectroscopy, and pyrolysis molecular beam mass spectrometry (py-MBMS), and for particle size distribution (PSD) using laser diffractometry (LD). Across the range of soil organic carbon (OC) removed by oxidations (14-72%), aliphatic C-H stretch at 3000-2800 cm^-1 (DRIFTS) decreased with OC removal, and this trend was enhanced by HF treatment due to significant demineralization in this soil (70%). Analysis by NMR spectroscopy was feasible only after HF treatment, and did not reveal trends between OC removal and C functional groups. Pyrolysis-MBMS did not detect differences among oxidations, even after HF treatment of soils. Hydrofluoric acid entailed OC loss (13-39%), and for H₂O₂ oxidized soils increased C:N and substantially decreased mean particle size. This study demonstrates the feasibility of using HF to improve characterizations of SOM composition following oxidations as practiced in soil science, in particular for DRIFTS. Since OC removal by oxidants, mineral removal by HF, and the interaction of oxidants and HF observed for this soil may differ for soils with different mineralogies, future work should examine additional soil and land use types to optimize characterizations of oxidation effects on SOM composition.

Transcriptome analysis of bladder biopsy from interstitial cystitis/bladder pain syndrome patients

Interstitial cystitis and bladder pain syndrome (IC/BPS) are terms used to describe a heterogeneous chronic pelvic and bladder pain disorder. Despite its significant prevalence, the disease etiology is not well understood and providing diagnosis and treatment can be challenging. In our study, published recently in the Journal of Urology (Colaco et al., 2014), we describe the use of microarrays as a tool to characterize IC/BPS and to determine if there are clinical factors that correlate with gene expression. This data-in-brief article describes the methodology for that study, including data analysis, in further detail. Deposited data can be found in the Gene Expression Omnibus (GEO) database: GSE57560.

Current recommendations for bladder instillation therapy in the treatment of interstitial cystitis/bladder pain syndrome

Bladder instillation therapy refers to the direct introduction of medication into the bladder and is a common treatment modality for patients with interstitial cystitis/bladder pain syndrome (IC/BPS) who have failed conservative and oral therapies. The current American Urological Association (AUA) recommendations list three medications as options for IC/BPS instillation therapy: dimethyl sulfoxide, heparin, and lidocaine. The purpose of this review is to examine the evidence behind the recommendations for these medications. We also examine several historical or experimental therapies that do not hold recommendations but are still used on rare occasion. Finally, we discuss our bladder instillation strategies as well as potential future research and development in intravesicular therapy.

Amplification of human platelet activation by surface pannexin-1 channels

BACKGROUND

Pannexin-1 (Panx1) forms an anion-selective channel with a permeability up to ~1 kDa and represents a non-lytic, non-vesicular ATP release pathway in erythrocytes, leukocytes and neurons. Related connexin gap junction proteins have been reported in platelets; however, the expression and function of the pannexins remain unknown.

OBJECTIVE

To determine the expression and function of pannexins in human plate-lets, using molecular, cellular and functional techniques.

METHODS

Panx1 expression in human platelets was det-ermined using qPCR and antibody-based techniques. Contributions of Panx1 to agonist-evoked efflux of cytoplasmic calcein, Ca(2+) influx, ATP release and aggregation were assessed in washed platelets under conditions where the P2X1 receptor response was preserved (0.32 U mL(-1) apyrase). Thrombus formation in whole blood was assessed in vitro using a shear chamber assay. Two structurally unrelated and widely used Panx1 inhibitors, probenecid and carbenoxolone, were used throughout this study, at concentrations that do not affect connexin channels.

RESULTS

PANX1, but not PANX2 or PANX3, mRNA was detected in human platelets. Furthermore, Panx1 protein is glycosylated and present on the plasma membrane of platelets, and displays weak physical association with P2X1 receptors. Panx1 inhibition blocked thrombin-evoked efflux of calcein, and reduced Ca(2+) influx, ATP release, platelet aggregation and thrombus formation under arterial shear rates in vitro. The Panx1-dependent contribution was not additive to that of P2X1 receptors.

CONCLUSIONS

Panx1 is expressed on human platelets and amplifies Ca(2+) influx, ATP release and aggregation through the secondary activation of P2X1 receptors. We propose that Panx1 represents a novel target for the management of arterial thrombosis.

Correlation of gene expression with bladder capacity in interstitial cystitis/bladder pain syndrome

PURPOSE

Interstitial cystitis and bladder pain syndrome are terms used to describe a heterogeneous chronic pelvic and bladder pain disorder. Despite its significant prevalence, our understanding of disease etiology is poor. We molecularly characterized interstitial cystitis/bladder pain syndrome and determined whether there are clinical factors that correlate with gene expression.

MATERIALS AND METHODS

Bladder biopsies from female subjects with interstitial cystitis/bladder pain syndrome and female controls without signs of the disease were collected and divided into those with normal and low anesthetized bladder capacity, respectively. Samples then underwent RNA extraction and microarray assay. Data generated by these assays were analyzed using Omics Explorer (Qlucore, Lund, Sweden), GeneSifter® Analysis Edition 4.0 and Ingenuity® Pathway Analysis to determine similarity among samples within and between groups, and measure differentially expressed transcripts unique to each phenotype.

RESULTS

A total of 16 subjects were included in study. Principal component analysis and unsupervised hierarchical clustering showed clear separation between gene expression in tissues from subjects with low compared to normal bladder capacity. Gene expression in tissue from patients with interstitial cystitis/bladder pain syndrome who had normal bladder capacity did not significantly differ from that in controls without interstitial cystitis/bladder pain syndrome. Pairwise analysis revealed that pathways related to inflammatory and immune response were most involved.

CONCLUSIONS

Microarray analysis provides insight into the potential pathological condition underlying interstitial cystitis/bladder pain syndrome. This pilot study shows that patients with this disorder who have low compared to normal bladder capacity have significantly different molecular characteristics, which may reflect a difference in disease pathophysiology.

Discovery and characterization of LY2784544, a small-molecule tyrosine kinase inhibitor of JAK2V617F

Owing to the prevalence of the JAK2V617F mutation in myeloproliferative neoplasms (MPNs), its constitutive activity, and ability to recapitulate the MPN phenotype in mouse models, JAK2V617F kinase is an attractive therapeutic target. We report the discovery and initial characterization of the orally bioavailable imidazopyridazine, LY2784544, a potent, selective and ATP-competitive inhibitor of janus kinase 2 (JAK2) tyrosine kinase. LY2784544 was discovered and characterized using a JAK2-inhibition screening assay in tandem with biochemical and cell-based assays. LY2784544 in vitro selectivity for JAK2 was found to be equal or superior to known JAK2 inhibitors. Further studies showed that LY2784544 effectively inhibited JAK2V617F-driven signaling and cell proliferation in Ba/F3 cells (IC₅₀=20 and 55 nM, respectively). In comparison, LY2784544 was much less potent at inhibiting interleukin-3-stimulated wild-type JAK2-mediated signaling and cell proliferation (IC₅₀=1183 and 1309 nM, respectively). In vivo, LY2784544 effectively inhibited STAT5 phosphorylation in Ba/F3-JAK2V617F-GFP (green fluorescent protein) ascitic tumor cells (TED₅₀=12.7 mg/kg) and significantly reduced (P<0.05) Ba/F3-JAK2V617F-GFP tumor burden in the JAK2V617F-induced MPN model (TED₅₀=13.7 mg/kg, twice daily). In contrast, LY2784544 showed no effect on erythroid progenitors, reticulocytes or platelets. These data suggest that LY2784544 has potential for development as a targeted agent against JAK2V617F and may have properties that allow suppression of JAK2V617F-induced MPN pathogenesis while minimizing effects on hematopoietic progenitor cells.

Discovery and characterization of LY2784544, a small-molecule tyrosine kinase inhibitor of JAK2V617F

Owing to the prevalence of the JAK2V617F mutation in myeloproliferative neoplasms (MPNs), its constitutive activity, and ability to recapitulate the MPN phenotype in mouse models, JAK2V617F kinase is an attractive therapeutic target. We report the discovery and initial characterization of the orally bioavailable imidazopyridazine, LY2784544, a potent, selective and ATP-competitive inhibitor of janus kinase 2 (JAK2) tyrosine kinase. LY2784544 was discovered and characterized using a JAK2-inhibition screening assay in tandem with biochemical and cell-based assays. LY2784544 in vitro selectivity for JAK2 was found to be equal or superior to known JAK2 inhibitors. Further studies showed that LY2784544 effectively inhibited JAK2V617F-driven signaling and cell proliferation in Ba/F3 cells (IC50=20 and 55 nM, respectively). In comparison, LY2784544 was much less potent at inhibiting interleukin-3-stimulated wild-type JAK2-mediated signaling and cell proliferation (IC50=1183 and 1309 nM, respectively). In vivo, LY2784544 effectively inhibited STAT5 phosphorylation in Ba/F3-JAK2V617F-GFP (green fluorescent protein) ascitic tumor cells (TED50=12.7 mg/kg) and significantly reduced (P<0.05) Ba/F3-JAK2V617F-GFP tumor burden in the JAK2V617F-induced MPN model (TED50=13.7 mg/kg, twice daily). In contrast, LY2784544 showed no effect on erythroid progenitors, reticulocytes or platelets. These data suggest that LY2784544 has potential for development as a targeted agent against JAK2V617F and may have properties that allow suppression of JAK2V617F-induced MPN pathogenesis while minimizing effects on hematopoietic progenitor cells.

In vivo and in vitro models for the therapeutic targeting of Wnt signaling using a Tet-OΔN89β-catenin system

Although significant progress has been made in understanding the importance of Wnt signaling in the initiation of colorectal cancer, less is known about responses that accompany the reversal of oncogenic Wnt signaling. The aim of this study was to analyze in vivo and in vitro responses to an 'ideal' Wnt pathway inhibitor as a model for the therapeutic targeting of the pathway. A tetracycline-inducible transgenic mouse model expressing truncated β-catenin (ΔN89β-catenin) that exhibited a strong intestinal hyperplasia was analyzed during the removal of oncogenic β-catenin expression both in 3D 'crypt culture' and in vivo. Oncogenic Wnt signaling was rapidly and completely reversed. The strongest inhibition of Wnt target gene expression occurred within 24 h of doxycycline removal at which time the target genes Ascl2, Axin2 and C-myc were downregulated to levels below that in the control intestine. In vitro, the small molecule Wnt inhibitor CCT036477 induced a response within 4 h of treatment. By 7 days following doxycycline withdrawal, gene expression, cell proliferation and tissue morphology were undistinguishable from control animals.In conclusion, these results demonstrate that the reversal of Wnt signaling by inhibitors should ideally be studied within hours of treatment. The reversible system described, involving medium throughput in vitro approaches and rapid in vivo responses, should allow the rapid advance of early stage compounds into efficacy models that are more usually considered later in the drug discovery pipeline.

Molecular basis of selective antagonism of the P2X1 receptor for ATP by NF449 and suramin: contribution of basic amino acids in the cysteine-rich loop

BACKGROUND AND PURPOSE

The cysteine-rich head region, which is adjacent to the proposed ATP-binding pocket in the extracellular ligand-binding loop of P2X receptors for ATP, is absent in the antagonist-insensitive Dictyostelium receptors. In this study we have determined the contribution of the head region to the antagonist action of NF449 and suramin at the human P2X1 receptor.

EXPERIMENTAL APPROACH

Chimeras and point mutations in the cysteine-rich head region were made between human P2X1 and P2X2 receptors. Mutant receptors were expressed in Xenopus oocytes and P2X receptor currents characterized using two-electrode voltage clamp.

KEY RESULTS

The chimera replacing the region between the third and fourth conserved cysteine residues of the P2X1 receptor with the corresponding part of P2X2 reduced NF449 sensitivity a thousand fold from an IC₅₀ of ∼1 nM at the P2X1 receptor to that of the P2X2 receptor (IC₅₀∼1 µM). A similar decrease in sensitivity resulted from mutation of four positively charged P2X1 receptor residues in this region that are absent from the P2X2 receptor. These chimeras and mutations were also involved in determining sensitivity to the antagonist suramin. Reciprocal chimeras and mutations in the P2X2 receptor produced modest increases in antagonist sensitivity.

CONCLUSIONS AND IMPLICATIONS

These data indicate that a cluster of positively charged residues at the base of the cysteine-rich head region can account for the highly selective antagonism of the P2X1 receptor by the suramin derivative NF449.

A collaboratively-derived science-policy research agenda

The need for policy makers to understand science and for scientists to understand policy processes is widely recognised. However, the science-policy relationship is sometimes difficult and occasionally dysfunctional; it is also increasingly visible, because it must deal with contentious issues, or itself becomes a matter of public controversy, or both. We suggest that identifying key unanswered questions on the relationship between science and policy will catalyse and focus research in this field. To identify these questions, a collaborative procedure was employed with 52 participants selected to cover a wide range of experience in both science and policy, including people from government, non-governmental organisations, academia and industry. These participants consulted with colleagues and submitted 239 questions. An initial round of voting was followed by a workshop in which 40 of the most important questions were identified by further discussion and voting. The resulting list includes questions about the effectiveness of science-based decision-making structures; the nature and legitimacy of expertise; the consequences of changes such as increasing transparency; choices among different sources of evidence; the implications of new means of characterising and representing uncertainties; and ways in which policy and political processes affect what counts as authoritative evidence. We expect this exercise to identify important theoretical questions and to help improve the mutual understanding and effectiveness of those working at the interface of science and policy.

ATP-gated P2X1 ion channels protect against endotoxemia by dampening neutrophil activation

BACKGROUND

In sepsis, extracellular ATP, secreted by activated platelets and leukocytes, may contribute to the crosstalk between hemostasis and inflammation. Previously, we showed that, in addition to their role in platelet activation, ATP-gated P2X(1) ion channels are involved in promoting neutrophil chemotaxis.

OBJECTIVES

To elucidate the contribution of P2X(1) ion channels to sepsis and the associated disturbance of hemostasis.

METHODS

We used P2X(1) (-/-) mice in a model of lipopolysaccharide (LPS)-induced sepsis. Hemostasis and inflammation parameters were analyzed together with outcome. Mechanisms were further studied ex vivo with mouse and human blood or isolated neutrophils and monocytes.

RESULTS

P2X(1) (-/-) mice were more susceptible to LPS-induced shock than wild-type mice, despite normal cytokine production. Plasma levels of thrombin-antithrombin complexes were higher, thrombocytopenia was worsened, and whole blood coagulation time was markedly reduced, pointing to aggravated hemostasis disturbance in the absence of P2X(1). However, whole blood platelet aggregation occurred normally, and P2X(1) (-/-) macrophages displayed normal levels of total tissue factor activity. We found that P2X(1) (-/-) neutrophils produced higher amounts of reactive oxygen species. Increased amounts of myeloperoxidase were released in the blood of LPS-treated P2X(1) (-/-) mice, and circulating neutrophils and monocytes expressed higher levels of CD11b. Neutrophil accumulation in the lungs was also significantly augmented, as was lipid peroxidation in the liver. Desensitization of P2X(1) ion channels led to increased activation of human neutrophils and enhanced formation of platelet-leukocyte aggregates.

CONCLUSIONS

P2X(1) ion channels play a protective role in endotoxemia by negatively regulating systemic neutrophil activation, thereby limiting the oxidative response, coagulation, and organ damage.

Proof of concept trial of tanezumab for the treatment of symptoms associated with interstitial cystitis

PURPOSE

In this randomized, double-blind, placebo controlled phase 2 study we investigated tanezumab, a humanized monoclonal antibody that specifically inhibits nerve growth factor as a treatment for interstitial cystitis pain.

MATERIALS AND METHODS

Patients with interstitial cystitis received a single intravenous dose of 200 μg/kg tanezumab or placebo. Patients recorded daily pain scores (on an 11-point numerical rating scale) 7 days before attending study visits and completed a urinary symptom diary for 3 of those days. Patients also completed the Interstitial Cystitis Symptom Index questionnaire and a global response assessment. The primary end point was change in average daily numerical rating scale pain score from baseline to week 6. Secondary end points included global response assessment, Interstitial Cystitis Symptom Index score, micturition and urgency episode frequency per 24 hours, and mean voided volume per micturition. The incidence of adverse events was also assessed.

RESULTS

A total of 34 patients received tanezumab and 30 received placebo. At week 6 tanezumab produced a significant reduction from baseline in average daily pain score vs placebo (treatment difference [LS mean, 90% CI] was -1.4 [-2.2, -0.5]). A significantly higher proportion of patients on tanezumab responded as improved in the global response assessment and tanezumab also significantly reduced urgency episode frequency vs placebo. Tanezumab had no significant effect on Interstitial Cystitis Symptom Index score, micturition frequency or mean voided volume per micturition. The most common adverse events were headache (tanezumab 20.6%, placebo 16.7%) and paresthesia (tanezumab 17.6%, placebo 3.3%).

CONCLUSIONS

Tanezumab has shown preliminary efficacy in the treatment of pain associated with interstitial cystitis.

Abstract C211: Therapeutic utility of GSK-3 inhibitors for the treatment of cancer

Glycogen synthase kinase-3 (GSK-3) is a constitutively active protein kinase that plays a role in diverse signaling pathways. Initially described as a regulator of glycogen synthesis and metabolism, GSK-3 is now known to play a central role in a variety of cellular functions ranging from maintenance of stem cell function to regulation of cell cycle and apoptosis. In mammals, there are two highly homologous isoforms of GSK-3 (GSK-3α and GSK-3β) which share substrate specificity and functional properties. GSK3β is one of the key components of the β-catenin destruction complex and phosphorylation of β-catenin by GSK-3 targets the substrate protein for ubiquitylation and proteosomal destruction - conversely, inhibition of GSK-3β activity results in loss of phosphorylation sites and stabilization of β-catenin in the cellular cytoplasm and nucleus. GSK-3 expression and/or activity have been reported to be elevated in multiple tumor types, including pancreatic, gastric and colorectal carcinomas. Equally important, inhibition of GSK-3 expression in colorectal tumor cell lines via specific siRNAs induced apoptosis and attenuated the proliferation of tumor cells. Together, these findings suggest that GSK-3 inhibitors may represent a new class of therapeutic agents against colorectal cancer.

LY-GSK-3i is a novel, potent and selective ATP competitive inhibitor of both isoforms of GSK-3. In vitro, LY potently inhibits the enzymatic activity of GSK-3α and GSK-3β with IC50s of 1.5 nM and 0.9 nM, respectively. Pharmacologic activity of other GSK-3 inhibitors in the literature against cancer is not clear. LY-GSK-3i did not evidence useful antitumor activity in its own right against colorectal, ovarian or non-small cell lung (NSCL) tumor lines. However, when combined with different chemotherapeutic agents, LY was found to potentiate their pro-apoptotic activity. LY-GSK-3i was shown to significantly potentiate caspase-3 activation when combined cisplatin in HCT-116 and Colo-205 colorectal carcinoma lines. Enhancement of caspase-3 activity was also observed when LY-GSK-3i was combined with 5-fluorouracyl (5-FU) in HCT-116 cells. In order to explore the potential of LY-GSK-3i in other tumor types, we assessed the pro-apoptotic activity of the LY/cisplatin combination against ovarian (A2780) and lung (A549 and NCI-H460) cell lines. In all cases, LY-GSK-3i was shown to significantly elevate caspase-3 activity when compared to cisplatin alone. In vivo, administration of a single dose of LY-GSK-3i to xenograft-bearing mice lead to a time-and dose-dependent accumulation of the substrate protein -catenin in tumor tissues. In vivo xenograft growth studies revealed that administration of 5 mg/kg LY-GSK-3i in combination with cisplatin, given every 7 or 14 days, was sufficient to significantly improve the efficacy as compared to cisplatin alone given at the same intervals. Together, our findings provide evidence for the potential therapeutic utility of GSK-3 inhibitors for the treatment of cancer.

Citation Information: Mol Cancer Ther 2009;8(12 Suppl):C211.

Association between response to pentosan polysulfate sodium therapy for interstitial cystitis and patient questionnaire-based treatment satisfaction

OBJECTIVE

To evaluate the relationship between symptom reduction and satisfaction with pentosan polysulfate sodium (PPS) therapy in subjects with interstitial cystitis (IC).

METHODS

A secondary analysis was conducted in 128 subjects treated with PPS 300 mg/day (US Food and Drug Administration-approved dose) from a 32-week multicenter, randomized, double-blind study of 380 subjects with IC who were treated with PPS 300 mg/day, 600 mg/day, or 900 mg/day. Self-rated outcome measures included the O'Leary-Sant Interstitial Cystitis Symptom Index (ICSI) and a treatment satisfaction questionnaire. Treatment responders were defined as subjects having > or =30% reduction in ICSI from baseline to study end point.

RESULTS

A reduction in IC symptoms was associated with significantly higher satisfaction with PPS (p < 0.05). Compared with nonresponders, subjects achieving a > or = 30% reduction in ICSI were more likely to be pleased with PPS for IC symptoms, to have benefited from PPS for their IC symptoms, to recommend PPS for IC symptoms to others with the same condition, and to say that PPS provides better relief, based on prior experience with other IC treatments. Among all subjects at week 32, 75% said they would recommend PPS therapy for IC symptoms to others with the condition.

CONCLUSION

Despite limitations (lack of placebo control, use of a nonvalidated instrument), this analysis demonstrated significantly increased treatment satisfaction with PPS therapy among treatment responders versus nonresponders. There was a significant positive correlation between ICSI scores and response on the treatment satisfaction questionnaire. Treatment response and patient satisfaction with treatment are important clinical considerations in the management of patients with IC.

Rapid and recurrent neutrophil mobilization regulated by T134, a CXCR4 peptide antagonist

The CXCR4/stromal cell-derived factor-1 (SDF-1) axis plays important roles in development, leukocyte trafficking, HIV infection, and tumorigenesis. Its critical function in bone marrow stem cell and hematopoietic progenitor cell retention, homing and release has been well-characterized by genetic and pharmacological analyses. However, its role in neutrophil retention and release is still poorly understood. In this study, we demonstrated that T134, a peptide antagonist of human CXCR4, is also a potent antagonist of mouse CXCR4. Treatment of C57BL/6 mice with T134 resulted in a rapid and time-dependent increase of white blood cells (WBC) and neutrophils, as well as hematopoietic stem and progenitor cells in peripheral blood. Interestingly, recurrent WBC and neutrophil mobilization was achieved by repeated T134 treatment, and the T134-mediated increase and subsequent retreat of WBC and neutrophils correlated with T134 activity in the peripheral blood. Kinetic analysis revealed that T134 binding to CXCR4 did not induce any significant cell-surface receptor downregulation, indicating that T134-induced WBC and neutrophil mobilization is likely due to direct blockage of the CXCR4/SDF-1 interaction. The results from this study support an important role of CXCR4/SDF-1 axis in neutrophil retention and release in the marrow.

Orthosteric and allosteric binding sites of P2X receptors

P2X receptors for ATP comprise a distinct family of ligand gated ion channels with a range of properties. They have been shown to be involved in a variety of physiological processes including blood clotting, sensory perception, pain sensation, bone formation as well as inflammation and may provide a number of novel drug targets. In addition to the orthosteric site for ATP binding it has been suggested that there may be additional allosteric sites that regulate agonist action at the receptor. There is currently no crystal structure available for P2X receptors and the lack of sequence similarity to other ATP binding proteins has meant that a mutagenesis-based approach has been used primarily to investigate receptor structure-function. This review aims to provide an overview of recent work that gives an insight into residues involved in ATP action and allosteric regulation.

P2X1 and P2X4 receptor currents in mouse macrophages

BACKGROUND AND PURPOSE

Activation of P2X receptors on macrophages is an important stimulus for cytokine release. This study seeks evidence for functional expression of P2X receptors in macrophages that had been only minimally activated.

EXPERIMENTAL APPROACH

Whole-cell recordings were made from macrophages isolated 2-6 h before by lavage from mouse peritoneum, without further experimental activation. ATP (1-1000 muM) elicited inward currents in all cells (holding potential -60 mV). The properties of this current were compared among cells from wild type, P2X1 (-/-) and P2X4 (-/-) mice.

KEY RESULTS

Immunoreactivity for P2X1 and P2X4 receptors was observed in wild type macrophages but was absent from the respective knock-out mice. In cells from wild type mice, ATP and alpha beta methyleneATP (alpha beta meATP) evoked inward currents rising in 10-30 ms and declining in 100-300 ms: these were blocked by pyridoxal-phosphate-6-azophenyl-2',4'-disulphonic acid (PPADS, 10 microM). ATP also elicited a second, smaller ( approximately 10% peak amplitude), more slowly decaying (1-3 s) at concentrations > or =10 microM: this was resistant to PPADS and prolonged by ivermectin. Macrophages from P2X1 (-/-) mice responded to ATP (>100 microM) but not alpha beta meATP: these small currents were prolonged by ivermectin. Macrophages from P2X4 (-/-) mice responded to ATP and alpha beta meATP as cells from wild type mice, except that ATP did not evoke the small, slowly decaying component: these currents were blocked by PPADS.

CONCLUSION

Mouse peritoneal macrophages that are minimally activated demonstrate membrane currents in response to ATP and alpha beta meATP that have the predominate features of P2X1 receptors.

Purinergic 2X1 receptors mediate endothelial dependent vasodilation to ATP

ATP is an important endogenous mediator in the cardiovascular system. It induces endothelium dependent vasodilation, but the precise receptor pathway activated in this response is currently under debate. We have used traditional bioassay techniques to show that ATP-induced vasodilation in mesenteric vessels is endothelium-dependent. Furthermore, ATP-induced vasodilation was inhibited by both suramin and 2',3'-O-(2,4,6-trinitrophenyl)-ATP (TNP-ATP), consistent with a P2X(1)-, P2X(2)-, or P2X(3)-mediated event and was not potentiated by ivermectin, indicating that these responses were not P2X(4) receptor-mediated. ATP did not induce vasodilation in vessels from P2X (-/-)(1) mice, confirming an absolute requirement for this receptor. Finally, in pure cell populations of mouse mesenteric artery endothelial cells, we show that P2X(1) mRNA is specifically expressed. However, in line with observations in the brain, the P2X(1) present in endothelial cells does not seem to be recognized by conventional antibodies. Together, these results show that ATP-induced vasodilation is mediated by P2X(1) receptor activation on mesenteric arterial endothelial cells. These observations establish a critical role for P2X(1) receptors in the ATP vasodilator pathway.

Current diagnosis of interstitial cystitis: an evolving paradigm

Our approaches to the diagnosis of interstitial cystitis (IC) are evolving as a result of recent advances in our knowledge of the disease. With increasing awareness of IC prevalence and presentation, clinicians are identifying cases of IC earlier in the disease process. A diagnosis of IC can now be established without applying each step of the traditional diagnostic paradigm, which was designed to identify "classic" cases of IC. In this article, we present an updated paradigm for the diagnosis of IC based on recent clinical data and consensus discussions conducted at the International Consultation on Interstitial Cystitis in Japan (ICICJ) and the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)/Interstitial Cystitis Association (ICA) research symposium in 2003. The diagnosis is established on the basis of a thorough physical examination and the patient's history of urgency/frequency and/or pain in the absence of bacterial infection or malignancy. Use of a symptom questionnaire to capture and record the presence of all IC symptoms is helpful in establishing the diagnosis. In this evolving paradigm, all other diagnostic measures are optional. Evidence-based medicine does not require the use of either cystoscopy or urodynamics in a workup for IC.

Rational approaches to the treatment of patients with interstitial cystitis

Symptoms of interstitial cystitis can usually be successfully managed with heparinoid therapy to theoretically alter bladder urothelial abnormalities, and with oral medications to inhibit neural upregulation or to control mast cell dysfunction. Other forms of care ranging from intravesical therapy to endoscopic, percutaneous, or open surgery are options that may be used singly or in combination to optimize symptom reduction.

VCC-1, a novel chemokine, promotes tumor growth

We have identified a novel human gene by transcriptional microarray analysis, which is co-regulated in tumors and angiogenesis model systems with VEGF expression. Isolation of cDNA clones containing the full-length VCC-1 transcript from both human and mouse shows a 119 amino acid protein with a 22 amino acid cleavable signal sequence in both species. Comparison of the protein product of this gene with hidden Markov models of all known proteins shows weak but significant homology with two known chemokines, SCYA17 and SCYA16. Northern analysis of human tissues detects a 1 kb band in lung and skeletal muscle. Murine VCC-1 expression can also be detected in lung as well as thyroid, submaxillary gland, epididymis, and uterus tissues by slot blot analysis. By quantitative real time RT-PCR 71% of breast tumors showed 3- to 24-fold up-regulation of VCC-1. In situ hybridization of breast carcinomas showed strong expression of the gene in both normal and transformed mammary gland ductal epithelial cells. In vitro, human microvascular endothelial cells grown on fibronectin increase VCC-1 expression by almost 100-fold. In addition, in the mouse angioma endothelial cell line PY4.1 the gene was over-expressed by 28-fold 6 h after induction of tube formation while quiescent and proliferating cells showed no change. VCC-1 expression is also increased by VEGF and FGF treatment, about 6- and 5-fold, respectively. Finally, 100% of mice injected with NIH3T3 cells over-expressing VCC-1 develop rapidly progressing tumors within 21 days while no growth is seen in any control mice injected with NIH3T3 cells containing the vector alone. These results strongly suggest that VCC-1 plays a role in angiogenesis and possibly in the development of tumors in some tissue types.