Specialized pro-resolution mediators in the bladder: effects of resolvin E1 on diabetic bladder dysfunction in the type 1 diabetic male Akita mouse model.

BACKGROUND: One of the most common, but least studied, diabetic complication is diabetic bladder dysfunction. Current therapies include glucose control and symptom-based interventions. However, efficacy of these therapies is mixed and often have undesirable side effects. Diabetes is now known to be a chronic inflammatory disease. Specialized pro-resolving mediators are a class of compounds that promote the resolution of inflammation and have been shown to be effective in treating chronic inflammatory conditions. In this study we examine the ability of resolvin E1 to improve signs of diabetic bladder dysfunction. METHODS: Male Akita mice (Type 1 diabetic) develop hyperglycemia at 4 weeks and signs of bladder underactivity by 15 weeks. Starting at 15 weeks, mice were given one or two weeks of daily resolvin E1 and compared to age-matched wild type and untreated Akita mice. RESULTS: Resolvin E1 did not affect diabetic blood glucose after one week, although there was a slight decrease after two weeks. Diabetes decreased body weight and increased bladder weights and this was not affected by resolvin E1. Evan's blue dye extravasation (an indirect index of inflammation) was dramatically suppressed after one week of resolvin E1 treatment, but, surprisingly, had returned to diabetic levels after two weeks of treatment. Using cystometry, untreated Akita mice showed signs of underactivity (increased void volumes and intercontraction intervals). One week of resolvin E1treatment restored these cystometric findings back to control levels. After two weeks of treatment, cystometric changes were changed from controls but still significantly different from untreated levels, indicating a durable treatment effect even in the presence of increased inflammation at 2 weeks. CONCLUSIONS: Resolvin E1 has a beneficial effect on diabetic bladder dysfunction in the type 1 diabetic male Akita mouse model.

Single-port hidden incision endoscopic (HIdES) pediatric nephrectomy via pfannenstiel incision.

Laparoendoscopic single-site surgery (LESS) and hidden incision endoscopic surgery techniques are increasingly used in pediatric urology. For pediatric nephrectomy, access through a single Pfannenstiel incision is novel and may offer cosmetic benefit. In this retrospective study, we describe this approach and assess operative outcomes associated with this technique. Patients who underwent LESS nephrectomy through a single Pfannenstiel incision had minimal blood loss, short length of stay, low risk of surgical complications, and satisfactory wound healing. The Pfannenstiel approach to LESS nephrectomy is feasible, versatile, and achieves excellent operative and cosmetic outcomes, although direct comparison to other approaches is warranted.

Why Are Some People with Lower Urinary Tract Symptoms (LUTS) Depressed? New Evidence That Peripheral Inflammation in the Bladder Causes Central Inflammation and Mood Disorders.

Anecdotal evidence has long suggested that patients with lower urinary tract symptoms (LUTS) develop mood disorders, such as depression and anxiety, at a higher rate than the general population and recent prospective studies have confirmed this link. Breakthroughs in our understanding of the diseases underlying LUTS have shown that many have a substantial inflammatory component and great strides have been made recently in our understanding of how this inflammation is triggered. Meanwhile, studies on mood disorders have found that many are associated with central neuroinflammation, most notably in the hippocampus. Excitingly, work on other diseases characterized by peripheral inflammation has shown that they can trigger central neuroinflammation and mood disorders. In this review, we discuss the current evidence tying LUTS to mood disorders, its possible bidirectionally, and inflammation as a common mechanism. We also review modern theories of inflammation and depression. Finally, we discuss exciting new animal studies that directly tie two bladder conditions characterized by extensive bladder inflammation (cyclophosphamide-induced hemorrhagic cystitis and bladder outlet obstruction) to neuroinflammation and depression. We conclude with a discussion of possible mechanisms by which peripheral inflammation is translated into central neuroinflammation with the resulting psychiatric concerns.

Inflammation triggered by the NLRP3 inflammasome is a critical driver of diabetic bladder dysfunction.

Diabetes is a rapidly expanding epidemic projected to affect as many as 1 in 3 Americans by 2050. This disease is characterized by devastating complications brought about high glucose and metabolic derangement. The most common of these complications is diabetic bladder dysfunction (DBD) and estimates suggest that 50-80% of patients experience this disorder. Unfortunately, the Epidemiology of Diabetes Interventions and Complications Study suggests that strict glucose control does not decrease ones risk for incontinence, although it does decrease the risk of other complications such as retinopathy, nephropathy and neuropathy. Thus, there is a significant unmet need to better understand DBD in order to develop targeted therapies to alleviate patient suffering. Recently, the research community has come to understand that diabetes produces a systemic state of low-level inflammation known as meta-inflammation and attention has focused on a role for the sterile inflammation-inducing structure known as the NLRP3 inflammasome. In this review, we will examine the evidence that NLRP3 plays a central role in inducing DBD and driving its progression towards an underactive phenotype.

Framing the picture: Impact of radiographic imaging on parental vesicoureteral reflux management preferences.

INTRODUCTION/OBJECTIVE: Given the variety of treatment options for vesicoureteral reflux (VUR), shared decision making between clinicians and parents is essential. Despite its importance, shared decision making is limited by the framing effect - people process the same information differently depending on how it is presented. Studies have also demonstrated that showing patients their radiology images can impact behaviors. In this pilot study, we sought to determine if showing parents radiographic images could serve as a framing tool that impacts the decision of whether to pursue surgery, endoscopic intervention, or conservative management for VUR. METHODS: We designed a survey instrument which provided background on VUR and a hypothetical scenario of a 2-year-old child with VUR who had a breakthrough febrile urinary tract infection (UTI). Guideline-concordant management options were presented: (1) change antibiotics, (2) endoscopic management, or (3) open or laparoscopic surgery. All options were similarly presented regarding risks, benefits, and length of stay. Respondents were randomized into a group with no image accompanying the clinical scenario or a group which had a labeled image of a voiding cystourethrogram (VCUG) demonstrating unilateral VUR. Respondents also answered demographic and health experience questions. The instrument was published on Amazon's Mechanical Turk online work interface which provides reliable and validated results in VUR experiments. Parents aged 18-60 years old were eligible. Responses with failed attention questions, duplicate internet addresses, or submission times <1 or >30 min were disqualified. Data were analyzed using t-test, chi-square, and multinomial logistic regression. Sensitivity analyses were performed after excluding all responses submitted under 2, 3, and 5 min. RESULTS: There were a total of 914 responses, 426 met inclusion criteria. The presence or absence of a VCUG image did not result in a statically significant difference in the management decision (p = 0.081). Multinomial logistic regression demonstrated that prior UTI experience influenced the management decision (p = 0.027). Sensitivity analyses revealed a significant difference in the management decision when excluding responses <5 min (p = 0.039). CONCLUSION: In this analysis, there was no statistically significant framing effect by radiographic images on parental management decision for VUR. Multinomial analyses suggested that prior experience with UTI has an impact on VUR management decisions. These results need to be considered within the limitations of this pilot study - the respondents were given a hypothetical clinical scenario and the survey instrument cannot replace an in-office discussion. Further analyses on framing and its role in pre-operative counseling is warranted.

Diabetic bladder dysfunction progresses from an overactive to an underactive phenotype in a type-1 diabetic mouse model (Akita female mouse) and is dependent on NLRP3.

AIMS: Diabetic bladder dysfunction (DBD) is a prevalent diabetic complication thought to progress from overactive (OAB) to underactive (UAB) bladder. Previously we found OAB at 15 weeks in the Akita mouse, a genetic model of Type 1 diabetes. The first aim of this study assesses bladder function at 30 weeks to assess progression. In addition, inflammation triggered by the NLRP3 inflammasome is implicated in DBD. In a second aim we assessed a role for NLRP3 by crossing Akita mice with NLRP3-/- mice. MAIN METHODS: Akita mice were bred with NLRP3-/- mice. The effect of diabetes was assessed by comparing nondiabetic to diabetic mice (all NLRP3+/+). The effect of diabetes in the absence of the NLRP3 inflammasome was assessed by comparing nondiabetic/NLRP3-/- to diabetic/NLRP3-/- mice. Mice were assessed at 30 weeks for blood glucose (glucometer), inflammation (Evans blue), bladder morphology (histology) and bladder function (urodynamics). KEY FINDINGS: At 30 weeks blood glucose of nondiabetics and diabetics was not affected by the presence of absence of NLRP3. Diabetic/NLRP3+/+ mice showed bladder inflammation and detrusor hypertrophy which was blocked in the diabetic/NLRP3-/- mice, clearly showing a role for NLRP3. When bladder function was examined, diabetic/NLRP3+/+ showed an increase in voiding volume and a decrease in frequency, two signs of underactive bladder. However, in the NLRP3-/- mice, diabetes was unable to effectuate these changes, demonstrating that NLRP3-induced inflammation is responsible for UAB symptoms in these mice. SIGNIFICANCE: Akita diabetic mice progress from OAB to UAB. NLRP3 is a possible target to treat DBD.

A Multidimensional Bioinformatic Platform for the Study of Human Response to Surgery.

OBJECTIVE: To design and establish a prospective biospecimen repository that integrates multi-omics assays with clinical data to study mechanisms of controlled injury and healing. BACKGROUND: Elective surgery is an opportunity to understand both the systemic and focal responses accompanying controlled and well-characterized injury to the human body. The overarching goal of this ongoing project is to define stereotypical responses to surgical injury, with the translational purpose of identifying targetable pathways involved in healing and resilience, and variations indicative of aberrant peri-operative outcomes. METHODS: Clinical data from the electronic medical record combined with large-scale biological data sets derived from blood, urine, fecal matter, and tissue samples are collected prospectively through the peri-operative period on patients undergoing 14 surgeries chosen to represent a range of injury locations and intensities. Specimens are subjected to genomic, transcriptomic, proteomic, and metabolomic assays to describe their genetic, metabolic, immunologic, and microbiome profiles, providing a multidimensional landscape of the human response to injury. RESULTS: The highly multiplexed data generated includes changes in over 28,000 mRNA transcripts, 100 plasma metabolites, 200 urine metabolites, and 400 proteins over the longitudinal course of surgery and recovery. In our initial pilot dataset, we demonstrate the feasibility of collecting high quality multi-omic data at pre- and postoperative time points and are already seeing evidence of physiologic perturbation between timepoints. CONCLUSIONS: This repository allows for longitudinal, state-of-the-art geno-mic, transcriptomic, proteomic, metabolomic, immunologic, and clinical data collection and provides a rich and stable infrastructure on which to fuel further biomedical discovery.

Specialized pro-resolution mediators in the bladder: Receptor expression and recovery of bladder function from cystitis.

Inflammation is a central process in most benign bladder disorders, and its control is a delicate balance between initiating factors and resolving factors. While recent discoveries have shown a central role for the NLRP3 inflammasome in initiation, the resolving pathways remain unexplored. Resolution is controlled by specialized pro-resolution mediators (SPMs) functioning through seven receptors (six in rodents). Here we demonstrate expression of all seven in humans (six in mice) through immunocytochemistry. Expression was universal in urothelia with most also expressed in smooth muscle. We next explored the therapeutic potential of three SPMs; Resolvin E1 (RvE1), Maresin 1 (MaR1), and Protectin D1 (PD1). SPMs promote epithelial wound/barrier repair and RvE1 triggered dose-dependent wound closure in urothelia in vitro (scratch assay) (EC90 = 12.5 nM). MaR1 and PD1 were equally effective at this concentration. In vivo analyses employed a cyclophosphamide (CP) model of bladder inflammation (Day 0-CP [150 mg/kg], Day 1 to 3 SPM [25 µg/kg/day], Day 4 - analysis). All three SPMs reduced bladder inflammation (Evans blue) and bladder weights to control levels. Effects of RvE1 were also examined by urodynamics. CP decreased void volume, increased frequency and decreased bladder capacity while RvE1 restored values to control levels. Finally, SPMs reduce fibrosis and RvE1 reduced urothelial expression of TGF-ß and collagen I to control values. Together these results expand the known SPMs active in the bladder tissue and provide promising therapeutic targets for controlling inflammation in a wide variety of inflammation-associated benign bladder diseases.

Association between race and in-hospital outcomes in children with spina bifida following inpatient urologic surgery.

PURPOSE: Post-operative complication rates may vary among racial and/or ethnic groups and have not been previously described in individuals with spina bifida (SB) undergoing urologic surgery. The aim of this study was to compare in-hospital complication frequencies of individuals with SB following urologic surgery by race/ethnicity. METHODS: The Nationwide Inpatient Sample was used to identify pediatric patients with SB who underwent inpatient urologic procedures. A pediatric cohort (<18 years old) with SB that underwent urologic surgery were assessed. All analyses report weighted descriptive statistics, outcomes, and race/ethnicity was the primary predictor variable. The primary outcome of interest was post-operative complications which were defined using NSQIP ICD-9 code definitions. Secondary analysis included length of stay (LOS), and encounter cost was estimated using the cost-to-charge ratio files provided by the Healthcare Cost and Utilization Project. RESULTS: The unadjusted model showed no differences in complications, LOS, and cost. In the adjusted model there were no differences in complications, LOS, and cost between Black and White encounters. However, Hispanic ethnicity was associated with a 20%(95%CI: 4-40%) increase in LOS and 18%(95%CI: 2-35%, p = 0.02) increase in cost compared to White encounters. CONCLUSION: There was no evidence of variation for in-hospital complication rates among racial/ethnic groups undergoing urologic surgery. Hispanic ethnicity was associated with higher costs and longer LOS in pediatric SB encounters.

The Importance of Early Diagnosis and Management of Pediatric Neurogenic Bladder Dysfunction.

Neurogenic bladder dysfunction is a major source of urologic morbidity in children, especially in those with spina bifida (SB). Complications from progression of bladder dysfunction can include urinary tract infections (UTIs), urinary incontinence, upper tract deterioration, and renal dysfunction or failure. In these children, there has been a recent trend toward proactive rather than expectant management of neurogenic bladder. However, there is a lack of consensus on how to best achieve the three main goals of neurogenic bladder management: 1) preserving kidney function, 2) achieving continence (if desired by the family/individual), and 3) achieving social and functional urologic independence (if appropriate). Hence, our objective was to perform a narrative literature review to evaluate the approaches to diagnosis and management of pediatric neurogenic bladder dysfunction, with special focus on children with SB. The approach strategies vary across a spectrum, with a proactive strategy on one end of the spectrum and an expectant strategy at the other end. The proactive management strategy is characterized by early and frequent labs, imaging, and urodynamic (UDS) evaluation, with early initiation of clean intermittent catheterization (CIC) and proceeding with pharmacotherapy, or surgery if indicated. The expectant management strategy prioritizes surveillance labs and imaging prior to proceeding with invasive assessments and interventions such as UDS or pharmacotherapy. Both treatment strategies are currently utilized and data have historically been inconclusive in demonstrating efficacy of one regimen over the other. We performed a narrative literature evaluating proactive and expectant treatment strategies as they relate to diagnostics and management of Spina Bifida. From the available literature and our practice, a proactive strategy favors greater benefit in preventative management and may decrease risk of renal dysfunction compared with expectant management.

Specialized proresolution mediators in the bladder: annexin-A1 normalizes inflammation and bladder dysfunction during bladder outlet obstruction.

Bladder outlet obstruction (BOO) is ultimately experienced by ≈90% of men, most commonly secondary to benign prostatic hyperplasia. Inflammation is a critical driver of BOO pathology in the bladder and can be divided into two critical steps: initiation and resolution. Although great strides have been made toward understanding the initiation of inflammation in the bladder [through the NLR family pyrin domain containing 3 (NLRP3) inflammasome], no studies have examined resolution. Resolution is controlled by five classes of compounds known as specialized proresolving mediators (SPMs), all of which bind to one or more of the seven different receptors. Using immunocytochemistry, we showed the presence of six of the known SPM receptors in the bladder of control and BOO rats; the seventh SPM receptor has no rodent homolog. Expression was predominantly localized to urothelia, often with some expression in smooth muscle, but little to none in interstitial cells. We next examined the therapeutic potential of the annexin-A1 resolution system, also present in control and BOO bladders. Using the peptide mimetic Ac2-26, we blocked inflammation-initiating pathways (NLRP3 activation), diminished BOO-induced inflammation (Evans blue dye extravasation), and normalized bladder dysfunction (urodynamics). Excitingly, Ac2-26 also promoted faster and more complete functional recovery after surgical deobstruction. Together, the results demonstrate that the bladder expresses a wide variety of potential proresolving pathways and that modulation of just one of these pathways can alleviate many detrimental aspects of BOO and speed recovery after deobstruction. This work establishes a precedent for future studies evaluating SPM effectiveness in resolving the many conditions associated with bladder inflammation.NEW & NOTEWORTHY To our knowledge, this is the first study of proinflammation-resolving pathways in the bladder, which is the basis of a new pharmacological genus-dubbed "resolution pharmacology" aimed at reducing inflammation without creating an immunocompromised state. Inflammation plays a causative or exacerbating role in numerous bladder maladies. We documented proresolution receptors in the rat bladder and the effectiveness of a specialized proresolving mediator, annexin-A1, in alleviating detrimental aspects of bladder outlet obstruction and speeding recovery after deobstruction.

BOO induces fibrosis and EMT in urothelial cells which can be recapitulated in vitro through elevated storage and voiding pressure cycles.

PURPOSE: To determine the unique contributions from elevated voiding and storage pressures in the development of fibrosis and the epithelial-to-mesenchymal transition (EMT) in urothelial cells, and how progressive BOO pressure cycling is an important mechanical cue leading to these pathological changes. MATERIALS AND METHODS: Urothelial cells isolated from control, SHAM, 2 (acute)- or 6 (chronic)-week BOO rats treated with an inflammasome inhibitor or no drug. Total RNA was isolated and RT-PCR was conducted with custom primers for pro-fibrotic and EMT genes. In separate experiments, a rat urothelial cell line was exposed to cyclic pressure regimes characteristic of acute and chronic BOO in the presence or absence of an inflammasome inhibitor. Following exposure, RT-PCR was conducted, collagen content was determined and intracellular caspase-1 activity was measured. RESULTS: Urothelial cells isolated from acute and chronic BOO rat models demonstrated expression of pro-fibrotic and EMT genes. Similarly, MYP3 rat urothelial cells subjected to pressure cycling regimes that reflect intravesical pressures in the acute or chronic BOO bladder also demonstrated increased expression of pro-fibrotic and EMT genes, along with elevated soluble collagen. Treatment with inflammasome inhibitors reduced expression of pro-fibrotic genes in the rat model and pressure cycling model but had a limited effect on EMT. CONCLUSION: These results indicate that acute and chronic BOO pressure cycling are essential in the initiation and progression of fibrosis in the bladder via the NLRP3 inflammasome, but also provide new evidence that there is also an alternative NLRP3-independent pathway leading to EMT and fibrosis.

Immune Expression in Children With Vesicoureteral Reflux: A Pilot Study.

OBJECTIVE: To perform an exploratory, descriptive pilot study of the systemic and local immune environment in patients with vesicoureteral reflux (VUR) and bladder-bowel dysfunction (BBD). METHODS: Consecutive children with VUR undergoing intravesical ureteral reimplantation were enrolled. Patients were assessed for presence of BBD by reported patient history and validated questionnaire. Fresh blood and bladder tissue, collected at the time of surgery, were immediately processed for analysis. Immune cell compositions were determined via flow cytometry. Immune cell activation was also defined at the time of analysis. LegendPlex assay analysis was utilized to define levels of circulating chemokines and cytokines. RESULTS: A total of 7 patients were enrolled. Although percentages of circulating immune cells in the blood of those with VUR/BBD and VUR alone were similar, within bladder tissue, VUR/BBD demonstrated increased immune infiltrates compared to VUR alone. Bladder sample analysis showed that B cells, and Effector Memory and Naïve T cell percentages were significantly increased in VUR/BBD patients compared to VUR patients. T cell expression of PD1 was increased in bladder tissues of BBD/VUR. Additionally, analysis of circulating neutrophils displayed significantly increased upregulation of PDL-1 in patients with VUR/BBD vs those with VUR only. CONCLUSION: These pilot data suggest an immune-rich microenvironment is present within VUR. Severity of inflammation appeared to correlate with presence of BBD. This implies that targeting pelvic inflammation may be a novel therapy for children with VUR- or non-VUR-related BBD. Follow-up studies are currently underway.

Delayed presentation of urethrocutaneous fistulae after hypospadias repair.

BACKGROUND: Delayed urethrocutaneous fistula (UCF) presentation after hypospadias repair is rarely reported. The aim of this study is to report our experience with delayed UCF presenting more than 5 years after hypospadias repair. METHODS: We conducted a retrospective review of patients who underwent UCF repair (CPT codes 54,340 and 54,344) at our institution between 1997 and 2017. Delayed UCF presentation was defined as a single normal urinary stream after initial hypospadias repair and subsequent presentation of a UCF/s urinary stream more than 5 years after initial hypospadias or UCF repair. Demographic and clinical data were reviewed after approval from our institutional review committee. RESULTS: We identified 12 patients with delayed UCF. The mean age at hypospadias repair was 12.3 months (Range 6-32). The mean time to delayed UCF presentation was 11.5 years (Range 7.1-15.8). Four patients with delayed UCF (33.3%) required additional surgery for UCF recurrence with a mean time to recurrence of 2.2 years (Range < 1-5.6). CONCLUSIONS: Delayed UCF presentation can occur more than 15 years after initial repair. Pubertal penile skin changes and increased genital awareness in older children may be contributing factors as all but one presented at age 10 years or older. LEVEL OF EVIDENCE: III.

Cyclophosphamide-induced cystitis results in NLRP3-mediated inflammation in the hippocampus and symptoms of depression in rats.

Recent breakthroughs demonstrate that peripheral diseases can trigger inflammation in the brain, causing psychosocial maladies, including depression. While few direct studies have been made, anecdotal reports associate urological disorders with mental dysfunction. Thus, we investigated if insults targeted at the bladder might elicit behavioral alterations. Moreover, the mechanism of neuroinflammation elicited by other peripheral diseases involves the NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome, which is present in microglia in the brain and cleaves and activates proinflammatory cytokines such as IL-1ß. Thus, we further explored the importance of NLRP3 in behavioral and neuroinflammatory changes. Here, we used the well-studied cyclophosphamide (CP)-treated rat model. Importantly, CP and its metabolites do not cross the blood-brain barrier or trigger inflammation in the gut, so that any neuroinflammation is likely secondary to bladder injury. We found that CP triggered an increase in inflammasome activity (caspase-1 activity) in the hippocampus but not in the pons. Evans blue extravasation demonstrated breakdown of the blood-brain barrier in the hippocampal region and activated microglia were present in the fascia dentata. Both changes were dependent on NLRP3 activation and prevented with 2-mercaptoethane sulfonate sodium (Mesna), which masks the effects of the CP metabolite acrolein in the urine. Finally, CP-treated rats displayed depressive symptoms that were prevented by NLRP3 inhibition or treatment with Mesna or an antidepressant. Thus, we conclude that CP-induced cystitis causes NLRP3-dependent hippocampal inflammation leading to depression symptoms in rats. This study proposes the first-ever causative explanation of the previously anecdotal link between benign bladder disorders and mood disorders.

Parental Preferences for Vesicoureteral Reflux Treatment: A Crowd-sourced, Best-worst Scaling Study.

OBJECTIVE: To quantitatively evaluate parental preferences for the various treatments for vesicoureteral reflux using crowd-sourced best-worst scaling, a novel technique in urologic preference estimation. METHODS: Preference data were collected from a community sample of parents via 2 best-worst scaling survey instruments published to Amazon's Mechanical Turk online community. Attributes and attribute levels were selected following extensive review of the reflux literature. Respondents completed an object case best-worst scaling exercise to prioritize general aspects of reflux treatments and multiprofile case best-worst scaling to elicit their preferences for the specific differences in reflux treatments. Data were analyzed using multinomial logistic regression. Results from the object-case provided probability scaled values (PSV) that reflected the order of importance of attributes. RESULTS: We analyzed data for 248 and 228 respondents for object and multiprofile case BWS, respectively. When prioritizing general aspects of reflux treatment, effectiveness (PSV = 20.37), risk of future urinary tract infection (PSV = 14.85), and complication rate (PSV = 14.55) were most important to parents. Societal cost (PSV = 1.41), length of hospitalization (PSV = 1.09), and cosmesis (PSV = 0.91) were least important. Parents perceived no difference in preference for the cosmetic outcome of open vs minimally invasive surgery (P = .791). Bundling attribute preference weights, parents in our study would choose open surgery 74.9% of the time. CONCLUSION: High treatment effectiveness was the most important and preferred attribute to parents. Alternatively, cost and cosmesis were among the least important. Our findings serve to inform shared parent-physician decision-making for vesicoureteral reflux.

NLRP3 Promotes Diabetic Bladder Dysfunction and Changes in Symptom-Specific Bladder Innervation.

The NLRP3 inflammasome senses diabetic metabolites and initiates inflammation implicated in diabetic complications and neurodegeneration. No studies have investigated NLRP3 in diabetic bladder dysfunction (DBD), despite a high clinical prevalence. In vitro, we found that numerous diabetic metabolites activate NLRP3 in primary urothelial cells. In vivo, we demonstrate NLRP3 is activated in urothelia from a genetic type 1 diabetic mouse (Akita) by week 15. We then bred an NLRP3-/- genotype into these mice and found this blocked bladder inflammation and cystometric markers of DBD. Analysis of bladder innervation established an NLRP3-dependent decrease in overall nerve density and Aδ-fibers in the bladder wall along with an increase in C-fiber populations in the urothelia, which potentially explains the decreased sense of bladder fullness reported by patients and overactivity detected early in DBD. Together, the results demonstrate the role of NLRP3 in the genesis of DBD and suggest specific NLRP3-mediated neuronal changes can produce specific DBD symptoms.

Bladder decompensation and reduction in nerve density in a rat model of chronic bladder outlet obstruction are attenuated with the NLRP3 inhibitor glyburide.

Bladder outlet obstruction (BOO) leads to progressive voiding dysfunction. Acutely, obstruction triggers inflammation that drives bladder dysfunction. Over time, inflammation leads to decreased bladder nerve density and increased fibrosis, responsible for eventual decompensation and irreversibility. We have previously shown that BOO triggers inflammation, reduced bladder nerve density and increased fibrosis via activation of the NLRP3 inflammasome in an acutely obstructed (12-day) rat model. However, as BOO progresses, the bladder may become decompensated with an increase in postvoid residual volume and decreased voiding efficiency. Currently, we have examined rat bladder function and nerve densities after chronic BOO to determine whether NLRP3 plays a role in the decompensation at this stage. Four groups were examined: control, sham-operated, BOO, or BOO+gly (glyburide; an NLRP3 inhibitor). After 42 days, bladder weight, inflammation (Evans blue), urodynamics, and nerve density were measured. BOO greatly enhanced bladder weights and inflammation, while inflammation was prevented by glyburide. Voiding pressures were increased, and flow rates decreased in BOO and BOO+gly groups, demonstrating physical obstruction. No difference in frequency or voided volume was detected. However, postvoid residual volumes were greatly increased in BOO rats while BOO+gly rats were not different than controls. Moreover, there was a dramatic decrease in voiding efficiency in the chronic BOO rats, which was prevented with glyburide treatment. Finally, a reduction in nerve density was apparent with BOO and attenuated with glyburide. Together the results suggest a critical role for NLRP3 in mediating bladder decompensation and nerve density during chronic BOO.

Diabetic bladder dysfunction is associated with bladder inflammation triggered through hyperglycemia, not polyuria.

PURPOSE: Diabetes is a grave and progressive condition characterized by debilitating complications. Diabetic bladder dysfunction (DBD) is a very common complication with no specific treatments currently available. Unlike other tissues affected by this disease, the bladder is subjected to two independent insults; 1) polyuria, created by the osmotic effects of glucose in the urine, and 2) hyperglycemia itself. Based on our understanding of inflammation as a major contributor to the underlying organ damage in several other diabetic complications, its presence in the bladder during DBD and the contribution of polyuria and hyperglycemia to its development were assessed. METHODS: Awake, restrained cystometry was performed on wild type C57BL/6 mice and diabetic (Akita) mice on a C57BL/6 background at 15 weeks of age. A subgroup of the Akita mice were treated with phlorizin, an inhibitor of sodium-glucose linked transporter types 1 and 2 that prevents glucose reabsorption in the kidney. All groups were assessed for serum glucose, 4-hour voiding totals, and inflammation in the bladder (Evans blue assay). RESULTS: Akita mice develop cystometrically-defined DBD by 15 weeks of age, as evidenced by an increase in urinary frequency, a decrease in voiding volume, and an increase in post-voiding residual volume. Phlorizin effectively normalized serum glucose in these animals while increasing the urine output. Inflammation in the bladder was present in the diabetic animals at this time point, but not detectable in animals receiving phlorizin. CONCLUSION: Inflammation in the bladder of diabetic mice correlates with the development of DBD and is triggered by hyperglycemia, not polyuria.

Elevated hydrostatic pressure stimulates ATP release which mediates activation of the NLRP3 inflammasome via P2X4 in rat urothelial cells.

Partial bladder outlet obstruction (pBOO) is a prevalent urological condition commonly accompanied by increased intravesical pressure, inflammation, and fibrosis. Studies have demonstrated that pBOO results in increased NLRP3 inflammasome and caspase-1 activation and that ATP is released from urothelial cells in response to elevated pressure. In the present study, we investigated the role of elevated pressure in triggering caspase-1 activation via purinergic receptors activation in urothelial cells. Rat urothelial cell line, MYP3 cells, was subjected to hydrostatic pressures of 15 cmH2O for 60 min, or 40 cmH2O for 1 min to simulate elevated storage and voiding pressure conditions, respectively. ATP concentration in the supernatant media and intracellular caspase-1 activity in cell lysates were measured. Pressure experiments were repeated in the presence of antagonists for purinergic receptors to determine the mechanism for pressure-induced caspase-1 activation. Exposure of MYP3 cells to both pressure conditions resulted in an increase in extracellular ATP levels and intracellular caspase-1 activity. Treatment with P2X7 antagonist led to a decrease in pressure-induced ATP release by MYP3 cells, while P2X4 antagonist had no effect but both antagonists inhibited pressure-induced caspase-1 activation. Moreover, when MYP3 cells were treated with extracellular ATP (500 µM), P2X4 antagonist inhibited ATP-induced caspase-1 activation, but not P2X7 antagonist. We concluded that pressure-induced extracellular ATP in urothelial cells is amplified by P2X7 receptor activation and ATP-induced-ATP release. The amplified ATP signal then activates P2X4 receptors, which mediate activation of the caspase-1 inflammatory response.