Search

Aims: To discuss the role of autocrine/paracrine signaling of urothelial arginine vasopressin (AVP) on mammalian bladder capacities and micturition thresholds, impact of distension on water/urea reabsorption from the bladder, review of the literature to better characterize the central/peripheral effects of AVP, desmopressin (dAVP) toxicity, and urine biomarkers of nocturia., Methods: This review summarizes discussions during an International Consultation on Incontinence-Research Society 2024 think tank with respect to the role of urothelial AVP in aged individuals with nocturnal polyuria, impact of solute and water reabsorption by the bladder on uninterrupted sleep, central effects of AVP, pharmacological basis of dAVP toxicity, and biomarkers in nocturia/lower urinary tract dysfunction (LUTD) with neurological diseases., Results: Consensus recognized AVP function and pathways in the central nervous system (CNS), pre-proAVP localized using immunohistochemistry in bladder sections from adult/aged noncancerous human punch biopsies and rodent bladder sections is likely to accelerate the systemic uptake of water and urea from the bladder of anesthetized mice instilled with 3 H-water and 14 C-urea. Mechanisms for charged and uncharged solutes and water transport across the bladder, mechanism of dAVP toxicity, and utility of urine biomarkers in those with neurological diseases/nocturia were determined from literature reviews., Conclusion: Pre-proAVP is present in human/rodent bladders and may be involved in water reabsorption from bladder that prevents the sensation of fullness for uninterrupted sleep in healthy adults. The mechanism of action of AVP in the CNS was discussed, as was electrolyte/water transport across the bladder, the basis for dAVP toxicity, and feasibility of urine biomarkers to identify nocturia/LUTD with neurological diseases., (© 2024 The Author(s). Neurourology and Urodynamics published by Wiley Periodicals LLC.)

Introduction: Inflammation and neuronal hypersensitivity are reactive protective mechanisms after urothelial injury. In lower urinary tract dysfunctions (LUTD), such as urinary tract infection (UTI), bladder pain syndrome with interstitial cystitis (BPS/IC) and neurogenic LUTD after spinal cord injury (SCI), chronic inflammation can develop. It is unclear how the protective reactionary inflammation escalates into chronic disease in some patients., Methods: During its 2023 meeting in Bristol, the International Consultation on Incontinence-Research Society (ICI-RS) reviewed the urothelial and inflammatory changes after UTI, BPS/IC and SCI. Potential factors contributing to the evolution into chronic disease were explored in a think-tank., Results: Five topics were discussed. (1) Visceral fat metabolism participates in the systemic pro-inflammatory effect of noradrenalin in BPS/IC and SCI. Sympathetic nervous system-adipocyte-bladder crosstalk needs further investigation. (2) Sympathetic hyperactivity also potentiates immune depression in SCI and needs to be investigated in BPS/IC. Gabapentin and tumor necrosis factor-α are promising research targets. (3) The exact peripheral neurons involved in the integrative protective unit formed by nervous and immune systems need to be further identified. (4) Neurotransmitter changes in SCI and BPS/IC: Neurotransmitter crosstalk needs to be considered in identifying new therapeutic targets. (5) The change from eubiosis to dysbiosis in SCI can contribute to UTI susceptibility and needs to be unraveled., Conclusions: The think-tank discussed whether visceral fat metabolism, immune depression through sympathetic hyperactivity, peripheral nerves and neurotransmitter crosstalk, and the change in microbiome could provide explanations in the heterogenic development of chronic inflammation in LUTD. High-priority research questions were identified., (© 2023 The Authors. Neurourology and Urodynamics published by Wiley Periodicals LLC.)

Background and Purpose: The aim of this study is to decipher the underlying mechanisms of CCAAT/enhancer-binding protein delta (CEBPD)-enhanced glycolysis as well as the biological significance of CEBPD and MYC coamplification in urothelial carcinoma (UC)., Methods: In vitro analyses were conducted to examine the effects of altered CEBPD or MYC expression on UC cells. The in vivo effects of CEBPD overexpression in a high-glucose environment on tumour growth were investigated in xenografted induced diabetic severe combined immunodeficiency/beige mice. Data mining was used to cross-validate the associations between CEBPD and MYC copy number and transcriptional expression, quantitative reverse transcription-polymerase chain reaction, immunohistochemistry, chromogenic in situ hybridization, and in situ hybridization targeting microRNA were performed on 635 UC patient samples and xenograft samples. UC patient survival in relation to diabetes was validated by using the National Health Insurance Research Database., Results: CEBPD and MYC coamplification (29.6%) occurred at a high frequency, MYC expression promoted chromosomal instability, facilitating CEBPD copy number gain and expression. CEBPD promoted glucose uptake and lactate production by upregulating SLC2A1 and HK2, leading to mitochondrial fission, increased extracellular acidification rate and decreased oxygen consumption rate to fuel cell growth. CEBPD upregulated HK2 expression through multiple regulation pathways including MYC stabilization, suppression of FBXW7 transactivation and MYC-independent transcriptional suppression of hsa-miR-429. Clinical and xenografted experiments confirmed the growth advantage of CEBPD in relation to glucose metabolic dysregulation and the significant correlations between the expression of these genes., Conclusions: We confirmed that CEBPD has an oncogenic role in UC by activating AKT signalling and initiating metabolic reprogramming from mitochondrial oxidative phosphorylation to glycolysis to satisfy glucose addiction. These novel CEBPD- and MYC-centric multilayered positive feedback loops enhance cancer growth that could complement theranostic approaches., (© 2021 The Authors. Clinical and Translational Medicine published by John Wiley & Sons Australia, Ltd on behalf of Shanghai Institute of Clinical Bioinformatics.)

The mechanisms that link visceral mechanosensation to the perception of internal organ status (i.e., interoception) remain elusive. In response to bladder filling, the urothelium releases ATP, which is hypothesized to stimulate voiding function by communicating the degree of bladder fullness to subjacent tissues, including afferent nerve fibers. To determine if PIEZO channels function as mechanosensors in these events, we generated conditional urothelial Piezo1-, Piezo2-, and dual Piezo1/2-knockout (KO) mice. While functional PIEZO1 channels were expressed in all urothelial cell layers, Piezo1-KO mice had a limited phenotype. Piezo2 expression was limited to a small subset of superficial umbrella cells, yet male Piezo2-KO mice exhibited incontinence (i.e., leakage) when their voiding behavior was monitored during their active dark phase. Dual Piezo1/2-KO mice had the most affected phenotype, characterized by decreased urothelial responses to mechanical stimulation, diminished ATP release, bladder hypoactivity in anesthetized Piezo1/2-KO females but not males, and urinary incontinence in both male and female Piezo1/2-KO mice during their dark phase but not inactive light one. Our studies reveal that the urothelium functions in a sex- and circadian rhythm-dependent manner to link urothelial PIEZO1/2 channel-driven mechanotransduction to normal voiding function and behavior, and in the absence of these signals, bladder dysfunction ensues.

Introduction: The pathophysiology and management of male patients with lower urinary tract symptoms (LUTS) is still a matter of debate. In the past few years, the urothelium and the urinary microbiota represented important areas of research to improve the understanding and management of these patients. Aim of the present review was to summarize the available data on the urothelium and the microbiota related to male LUTS., Evidence Acquisition: A National Center for Biotechnology Information (NCBI) PubMed search for relevant articles published between January 2000 and December 2019 was performed using the medical subjects heading "urothelium," "microbioma," "microbiota," "urobioma," "urobiota," "benign prostatic hyperplasia," "benign prostatic enlargement," "lower urinary tract symptoms," "lower urinary tract dysfunction," "men," "male," "overactive bladder," "receptors." Exclusion criteria included: animal studies and studies on muscarinic and adrenergic pathways., Evidence Synthesis: The urothelium has been recently evaluated in humans to evaluate new possible markers and pathways. New possible targets for the treatment of male LUTS include the neural growth factor, the cannabinoid, the vanilloid and the ATP pathways. However, studies in humans are still needed to elucidate the exact role of these pathways in the management of male patients with LUTS. The available evidence on the urinary microbioma in male is poor. Standing to the available, urinary microbioma is evident in healthy urine in males. Moreover, the urinary microbioma varies depending on the method of collection, sexually transmitted disease status, inflammation and urinary symptoms. A possible role of probiotics in the management of LUTS in women has been proposed and may have a role in male patients as well., Conclusions: The urothelium and the urinary microbiota are still poorly studied in men with LUTS. Most of the evidence and the hypothesis on the relationship between urothelium/urinary microbiota and LUTS comes from animal/in-vitro evidence while clinical trials are lacking. These pathways seem interesting even in LUTS pathogenesis in men but their possible role as a new therapeutic target is still an open debate.

Introduction: The pathophysiology knowledge of the overactive bladder syndrome has evolved considerably over the past 20 years. The objective of this work was, from a review of the literature, to synthesize current knowledge on the pathophysiology of the overactive bladder syndrome., Method: A systematic review based on Pubmed, Embase, Google Scholar, was conducted in February 2020 using the keywords "overactive bladder" and "pathophysiology"., Results: Four pathophysiological mechanisms involved in the overactive bladder syndrome development can be described. They include the detrusor muscle dysfunction, an urothelial or sub-urothelial origin, a neurological origin and a change in the urinary microbiome. At the same time, it should be noted that all of the pathophysiological mechanisms described above are favored by different clinical conditions such as aging, ischemia, metabolic syndrome, menopause and the dysfunction of other abdominopelvic systems., Conclusion: The pathophysiology of the overactive bladder syndrome is complex and includes several mechanisms most often associated., (Copyright © 2020 Elsevier Masson SAS. All rights reserved.)

To examine the effects of intravenous and intravesical application of vibegron, a new β 3 -adrenoceptor (β 3 -AR) agonist, on bladder function in rats with oxotremorine methiodide (oxo-M: a nonselective muscarinic receptor agonist)-induced bladder overactivity. Cystometry was performed in conscious female rats with intravesical instillation of oxo-M (200 μM). In oxo-M-treated rats, vehicle or vibegron (1 and 10 mg/kg) was cumulatively applied intravenously at 30-min intervals. In other groups of rats, oxo-M + vehicle or oxo-M + vibegron (10, 100 μM, and 1 mM) was cumulatively instilled intravesically at 60-min intervals followed by intravenous application of vibegron (10 mg/kg). Expression of β 3 -ARs in the bladder was also evaluated using immunohistochemical staining. Intravenous application of vibegron (10 mg/kg) significantly increased bladder capacity (1.3 times) and decreased baseline, threshold, and maximal voiding pressure compared with vehicle. Next, intravesical application of vibegron (1 mM) significantly increased threshold pressure and bladder capacity (1.2 times) compared with vehicle. Combined treatments of intravesical (1 mM) and intravenous (10 mg/kg) application of vibegron induced a significantly larger degree of increases in bladder capacity (1.4 times) compared with vehicle. In addition, β 3 -ARs were expressed throughout the rat bladder, mainly in the urothelium. These results suggest that vibegron excreted in urine as an unchanged compound can induce the additive inhibitory effects on bladder overactivity possibly through urothelial β 3 -AR activation, which inhibits the afferent limb of micturition reflex rather than the efferent function as evidenced by the increases in threshold pressure and bladder capacity without affecting bladder contractile function after intravesical vibegron application.

Choreito (CRT), a traditional Japanese (Kampo) medicine, is widely used for the treatment of overactive bladder (OAB) and other lower urinary tract symptoms in Japan. This study aimed to identify the effects and therapeutic mechanism of CRT on the improvement of detrusor overactivity (DO) using an experimental rat model. Forty-five female Sprague-Dawley rats were equally divided into three groups: intravesical saline instillation with normal food (normal group), intravesical acetic acid (AA) instillation with normal food (AA group), and intravesical AA instillation with CRT (AA with CRT group). To induce a decrease in bladder capacity, instillation of 0.2% AA was used based on prior studies. Cystometric investigation was employed to clarify the effects of AA and CRT. Microcirculation was performed using a laser blood flowmeter, and the localization of hypoxia-inducible factor 1α (HIF1α) was assessed by immunohistochemistry. The bladder capacities of the normal, AA, and AA with CRT groups were 1.2 ± 0.3 mL, 0.4 ± 0.1 mL, and 0.8 ± 0.1 mL, respectively. CRT significantly attenuated AA irritation of the urinary bladder and exerted protective effects on basal pressure, micturition pressure, micturition interval, and micturition volume. Furthermore, CRT could prevent the excess blood flow and edematous change under the urothelium induced by intravesical AA instillation. No obvious changes in immunohistochemical HIF1α staining were observed among the groups. CRT attenuated DO induced by intravesical AA instillation in a rat experimental model. CRT might impart therapeutic effects on OAB via the mitigation of urothelial damage and regulation of excess blood flow., (© 2020 John Wiley & Sons Australia, Ltd.)

Introduction: The following is a report on the proceedings of the 2019 International Consultation on Incontinence-Research Society nocturia think tank (NTT)., Objectives: The objectives of the 2019 NTT were as follows: (a) to evaluate the role of urothelium in the pathophysiology of nocturia; (b) to determine whether nocturia is a circadian disorder; (c) to discuss the role of melatonin in nocturia; (d) to consider ambulatory urodynamic monitoring in evaluating patients with nocturia; (e) to explore studies of water handling in human compartments utilizing heavy water; and (f) to explore whether basic science is the key to understanding the treatment options for diminished bladder capacity in patients with nocturia., Methods: A compendium of discussions of the role of experimental science in understanding the pathophysiology of nocturia is described herein., Results and Conclusions: Translational science will play an increasing role in understanding the pathophysiology of nocturia, which may result in improved treatment strategies., (© 2020 Wiley Periodicals, Inc.)

In recent years, although the development of clinical therapy for diabetic kidney disease (DKD) has made great progress, the progression of DKD still cannot be controlled. Therefore, further study of the pathogenesis of DKD and improvements in DKD treatment are crucial for prognosis. Traditional studies have shown that podocyte injury plays an important role in this process. Recently, it has been found that glomerulotubular balance and tubuloglomerular feedback (TGF) may be involved in the progression of DKD. Glomerulotubular balance is the specific gravity absorption of the glomerular ultrafiltrate by the proximal tubules, which absorbs only 65% to 70% of the ultrafiltrate. This ensures that the urine volume will not change much regardless of whether the glomerular filtration rate (GFR) increases or decreases. TGF is one of the significant mechanisms of renal blood flow and self-regulation of GFR, but how they participate in the development of DKD in the pathological state and the specific mechanism is not clear. Injury to tubular epithelial cells (TECs) is the key link in DKD. Additionally, injury to glomerular endothelial cells (GECs) plays a key role in the early occurrence and development of DKD. However, TECs and GECs are close to each other in anatomical position and can crosstalk with each other, which may affect the development of DKD. Therefore, the purpose of this review was to summarize the current knowledge on the crosstalk between TECs and GECs in the pathogenesis of DKD and to highlight specific clinical and potential therapeutic strategies., (© 2020 The Authors. Cell Proliferation published by John Wiley & Sons Ltd.)

Alterations to arginine vasopressin (AVP) secretion, the urinary bladder urothelium (UT) and other components of the bladder, and the water homeostasis biosystem may be relevant to the pathophysiology of nocturia and nocturnal polyuria (NP). AVP is the primary hormone involved in water homeostasis. Disruption to the physiological release of AVP or its target effects may relate to several urinary disturbances. Circadian dysregulation and the effects of aging, for example, the development of oxidative stress and mitochondrial dysfunction, may play a role in nocturia voiding symptoms. The urinary bladder UT not only acts as a highly efficient barrier that is maintained during the filling and voiding of the urinary bladder, but is also capable of sensory and transducer function through a network of functional receptors and ion channels that enable reciprocal communication between UT cells and neighboring elements of the bladder mucosa and wall. Functional components of the UT (eg, claudins and receptors or ion channels) play important roles in AVP-mediated water homeostasis. These components and functions involved in water homeostasis, as well as kidney function, may be affected by the aging process, including age-related mitochondrial dysfunction. The characteristics of NP are discussed and the association between NP and circadian rhythm is examined in light of reports that suggest that nocturia should be considered as a type of circadian dysfunction. Many possible pathologic mechanisms that underlie nocturia and NP have been identified. Future studies may provide further insight into pathophysiology with the hope of identifying new treatment modalities., (Copyright © 2019. Published by Elsevier Inc.)

Aims: To measure the effects of nicotine on lower urinary tract symptoms (LUTS), bladder blood flow, and the urothelial markers hypoxia-inducible factor 1α (HIF1α), uroplakin III (UPIII), and aquaporin 3 (AQP3)., Methods: Ten-week-old female Sprague Dawley rats were subcutaneously injected with 2 mg/kg nicotine (n = 17) or vehicle (control, n = 18) twice daily for 13 days. Some nicotine-treated rats (n = 10) were injected daily with 1 mg/kg tadalafil for the last 6 days of nicotine treatment. One day before cystometry, the bladders of some nicotine-treated and control rats were instilled with 0.08% acetic acid. Urinary frequency and volume were measured 1 day after treatment. Blood flow in the bladder neck was measured, and the urothelia were immunochemically assayed for HIF1α, UPIII, and AQP3., Results: Following acetic acid treatment, both voiding interval and micturition volume of the nicotine-treated rats were significantly lower than controls. Nicotine-treated rats had lower blood flow than controls, and the urothelial expression of HIF1α was higher than controls. Simultaneously, the expressions of UPIII and AQP3 were decreased. Tadalafil treatment increased bladder blood flow, and nicotine-treated rats had increased voiding interval and micturition volume. Further, the expression of HIF1α decreased, and both UPIII and AQP3 levels increased., Conclusions: Nicotine-treated rats stimulated by intravesicular acetic acid instillation exhibited deterioration of bladder storage functions. Changes in tissue markers in the nicotine-treated rats were consistent with hypoxia and loss of urothelial function. Restoration of blood flow reversed the nicotine effects. Nicotine may induce LUTS through reduced bladder blood flow and urothelial hypoxia., (© 2019 Wiley Periodicals, Inc.)

Context: Current literature suggests that several pathophysiological factors and mechanisms might be responsible for the nonspecific symptom complex of overactive bladder (OAB)., Objective: To provide a comprehensive analysis of the potential pathophysiology underlying detrusor overactivity (DO) and OAB., Evidence Acquisition: A PubMed-based literature search was conducted in April 2018, to identify randomised controlled trials, prospective and retrospective series, animal model studies, and reviews., Evidence Synthesis: OAB is a nonspecific storage symptom complex with poorly defined pathophysiology. OAB was historically thought to be caused by DO, which was either "myogenic" (urgency initiated from autonomous contraction of the detrusor muscle) or "neurogenic" (urgency signalled from the central nervous system, which initiates a detrusor contraction). Patients with OAB are often found to not have objective evidence of DO on urodynamic studies; therefore, alternative mechanisms for the development of OAB have been postulated. Increasing evidence on the role of urothelium/suburothelium and bladder afferent signalling arose in the early 2000s, emphasising an afferent "urotheliogenic" hypothesis, namely, that urgency is initiated from the urothelium/suburothelium. The urethra has also recently been regarded as a possible afferent origin of OAB-the "urethrogenic" hypothesis. Several other pathophysiological factors have been implicated, including metabolic syndrome, affective disorders, sex hormone deficiency, urinary microbiota, gastrointestinal functional disorders, and subclinical autonomic nervous system dysfunctions. These various possible mechanisms should be considered as contributing to diagnostic and treatment algorithms., Conclusions: There is a temptation to label OAB as "idiopathic" without obvious causation, given the poorly understood nature of its pathophysiology. OAB should be seen as a complex, multifactorial symptom syndrome, resulting from multiple potential pathophysiological mechanisms. Identification of the underlying causes on an individual basis may lead to the definition of OAB phenotypes, paving the way for personalised medical care., Patient Summary: Overactive bladder (OAB) is a storage symptom syndrome with multiple possible causes. Identification of the mechanisms causing a patient to experience OAB symptoms may help tailor treatment to individual patients and improve outcomes., (Copyright © 2019 European Association of Urology. Published by Elsevier B.V. All rights reserved.)

The results of recent studies on the mechanisms of kidney damage are presented in the review of literature. The role of the immune system in the occurrence, development and outcome of damage to the epithelium of the renal tubules, as well as molecular, genetic and metabolic changes which determine the extent and consequences of renal trauma are described in details. The mechanisms of restoration of the renal parenchyma and the development of fibrosis following the cessation of injury are given.

This study aimed to compare the oncologic outcomes between retroperitoneal radical nephroureterectomy (rRNU) and transperitoneal radical nephroureterectomy (tRNU) for the treatment of patients with upper urinary tract urothelial carcinoma (UTUC). Medical records of 743 eligible patients who underwent rRNU or tRNU between 1995 and 2015 were reviewed retrospectively. Progression-free survival (PFS), cancer-specific survival (CSS), and overall survival (OS) were compared according to the surgical approach using the Kaplan-Meier method. Predictors of PFS, CSS, and OS were analyzed with a multivariable Cox regression model. Overall, 620 (83.4%) and 123 (16.6%) patients were treated with rRNU and tRNU, respectively. Five-year CSS and OS rates were equivalent between rRNU and tRNU groups, but 5-year PFS was lower in the tRNU group than the rRNU group (P = 0.005). When patients were stratified by pathological T stage, PFS was significantly different between the two groups in favor of the rRNU group for both organ-confined disease (pTis/pTa/pT1/T2) (P = 0.022) and locally advanced disease (pT3/pT4) (P = 0.039). However, no significant differences in CSS or OS was observed when comparing the two surgical types in patients with organ-confined disease (P = 0.336 and P = 0.851) or patients with locally advanced disease (P = 0.499 and P = 0.278). tRNU was a significant predictor of PFS (hazard ratio = 1.54; P = 0.023), but not CSS or OS. Our findings indicate that the rRNU approach resulted in better PFS than the tRNU approach in patients with UTUC.

The internal surface of the bladder is lined by the urothelium, a stratified epithelium that forms an impermeable barrier to water and urine constituents. Abnormalities in the urothelial barrier have been described in certain forms of cystitis and were hypothesized to contribute to irritative voiding symptoms and pain by allowing the permeation of urinary K + into suburothelial tissues, which then alters afferent signaling and smooth muscle function. Here, we examined the mechanisms underlying organ hyperactivity and pain in a model of cystitis caused by adenoviral-mediated expression of claudin-2 (Cldn2), a tight junction protein that forms paracellular pores and increases urothelial permeability. We found that in the presence of a leaky urothelium, intravesical K + sensitizes bladder afferents and enhances their response to distension. Notably, dietary K + restriction, a maneuver that reduces urinary K + , prevented the development of pelvic allodynia and inflammation seen in rats expressing Cldn2. Most importantly, intravesical K + causes and is required to maintain bladder hyperactivity in rats with increased urothelial permeability. Our study demonstrates that in the face of a leaky urothelium, urinary K + is the main determinant of afferent hyperexcitability, organ hyperactivity and pain. These findings support the notion that voiding symptoms and pain seen in forms of cystitis that coexist with urothelial barrier dysfunction could be alleviated by cutting urinary K + levels.

Aim: Chronic stress exacerbates the symptoms of most pain disorders including interstitial cystitis/bladder pain syndrome (IC/BPS). Abnormalities in urothelial cells (UTC) occur in this debilitating bladder condition. The sequence of events that might link stress (presumably through increased sympathetic nervous system-SNS activity) to urothelial dysfunction are unknown. Since autonomic dysregulation, mitochondrial dysfunction, and oxidative stress all occur in chronic pain, we investigated whether chronic psychological stress initiated a cascade linking these three dysfunctions., Methods: Adult female Wistar Kyoto rats were exposed to 10 days of water avoidance stress (WAS). Bladders were then harvested for Western blot and single cell imaging in UTC cultures., Results: UTC from WAS rats exhibited depolarized mitochondria membrane potential (Ψm ∼30% more depolarized compared to control), activated AMPK and altered UT mitochondria bioenergetics. Expression of the fusion protein mitofusion-2 (MFN-2) was upregulated in the mucosa, suggesting mitochondrial structural changes consistent with altered cellular metabolism. Intracellular calcium levels were elevated in cultured WAS UTC, consistent with impaired cellular function. Stimulation of cultured UTC with alpha-adrenergic (α-AR) receptor agonists increased reactive oxidative species (ROS) production, suggesting a direct action of SNS activity on UTC. Treatment of rats with guanethidine to block SNS activity prevented most of WAS-induced changes., Conclusions: Chronic stress results in persistent sympathetically mediated effects that alter UTC mitochondrial function. This may impact the urothelial barrier and signaling, which contributes to bladder dysfunction and pain. This is the first demonstration, to our knowledge, of a potential autonomic mechanism directly linking stress to mitochondrial dysfunction., (© 2018 Wiley Periodicals, Inc.)

Objective: To evaluate the changes in urothelial dysfunction protein expressions in bladder after onabotulinumtoxin injection and correlate that with clinical outcomes in spinal cord injury (SCI) patients., Methods: Twenty-six patients with neurogenic detrusor overactivity (NDO) and urinary incontinence due to suprasacral SCI were treated with onabotulinumtoxinA 200U detrusor injection. Urodynamic studies and bladder biopsies were obtained at baseline, 3, and 6 months after treatment. Biopsy tissues were investigated for E-cadherin, zonula occludens-1 (ZO-1), mast cell activity, and urothelial cell apoptosis, sensory protein expression including purinergic receptor P2X3, endothelial NOS, inducible NOS, β3-adrenoceptors, and muscarinic receptors M2 and M3. Differences in functional protein expression between controls and SCI patients and between successful and failed treatment groups were analyzed., Results: SCI patients had significantly lower E-cadherin, higher mast cell activity, increased apoptosis, decreased M3 and eNOS expressions than the controls at baseline. Of the 26 patients, 17 (65%) showed improvement in bladder capacity by >50% at 3 months; however, improvement declined by 6 months after treatment. The urothelial expression of E-cadherin and ZO-1 increased at 3 months but had declined at 6 months. The urothelial sensory protein expression did not change significantly after treatment. M3 receptor density was significantly decreased in SCI patients at baseline and patients with treatment success 3 months after injection (p = 0.01)., Conclusion: A single injection of onabotulinumtoxinA 200U improved clinical symptoms but did not significantly alter urothelial sensory protein expression. The results imply that a single 200U onabotulinumtoxinA dose might not be adequate for urothelial dysfunction in NDO. IRB: TCGH 098-53., (Copyright © 2018. Published by Elsevier B.V.)

The urothelium is an epithelia barrier lined by a luminal layer of binucleated, octoploid, superficial cells. Superficial cells are critical for production and transport of uroplakins, a family of proteins that assemble into a waterproof crystalline plaque that helps protect against infection and toxic substances. Adult urothelium is nearly quiescent, but rapidly regenerates in response to injury. Yet the mechanism by which binucleated, polyploid, superficial cells are produced remains unclear. Here, we show that superficial cells are likely to be derived from a population of binucleated intermediate cells, which are produced from mononucleated intermediate cells via incomplete cytokinesis. We show that binucleated intermediate and superficial cells increase DNA content via endoreplication, passing through S phase without entering mitosis. The urothelium can be permanently damaged by repetitive or chronic injury or disease. Identification of the mechanism by which superficial cells are produced may be important for developing strategies for urothelial repair., (Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.)

Urinary tract obstruction represents a common cause of kidney injury across the human life span, resulting in chronic kidney disease and end-stage renal disease. Yet, the extent of obstructive renal damage can be heterogeneous between individuals, implying the existence of unknown mechanisms that protect against or accelerate kidney injury. In this study, we investigated the role of urothelial remodeling in renal adaptation during congenital and acquired obstruction. In the Megabladder ( Mgb -/- ) model of congenital obstruction and unilateral ureteral ligation model of acute obstruction, progressive hydronephrosis is strongly associated with dynamic reorganization of the renal urothelium, which elaborates a continuous uroplakin (Upk) plaque. This led us to postulate that the Upk plaque prevents parenchymal injury during urinary tract obstruction. To test this hypothesis, we interbred Mgb -/- and Upk1b -/- mice, which lack the critical Upk1b subunit for Upk plaque formation. Upk1b -/- ; Mgb -/- mice experienced an accelerated onset of bilateral hydronephrosis with severe (>67%) parenchymal loss, leading to renal failure and mortality in adolescence. To investigate the function of the renal Upk plaque during acute obstruction, we destabilized the Upk plaque by Upk1b deletion or genetically depleted Upk + cells following unilateral ureteral obstruction. Both of these strategies accelerated renal parenchymal loss following ureteral ligation, attesting to a conserved, stabilizing role for Upk plaque deposition in the acutely obstructed kidney. In aggregate, these complementary experiments provide the first evidence that the Upk plaque confers an essential, protective adaptation to preserve renal parenchymal integrity during congenital and acquired urinary tract obstruction.

Aims: Botulinum toxin A (BTX-A) and sacral nerve stimulation (SNS) are established treatments for overactive bladder (OAB) and are standard of care in refractory cases in international guidelines. Despite long term use over decades their "exact" working mechanisms are not entirely clear. At the ICI-RS meeting in Bristol in 2017 a think tank was convened to address the question., Methods: The think tank conducted a literature review and an expert consensus meeting focusing on current mechanisms and what could be learned from clinical experience and objective urodynamic data., Results: BTX-A results suggests effects on both filling and voiding parts of the micturition cycle. The salient data in this regard is presented as well as additional studies related to the urothelium and evidence for central effects. Urodynamics have consistently shown increases in bladder capacity, compliance, and reductions in detrusor pressures during filling, however post void residuals also increase in a dose-dependent fashion. During SNS activation of somatic afferents inhibits bladder sensory pathways and reflex bladder hyperactivity. Evidence in cats suggest the inhibition of bladder activity occurs primarily in the CNS by inhibition of the ascending or descending pathways of the spinobulbospinal micturition reflex. Urodynamics have suggested improvement in bladder capacity and reduction in detrusor pressures during filling with little observed effects on voiding parameters., Conclusions: The working mechanism of BTX-A and SNS is complex. The exact mechanisms are still unknown, although considerable progress has been made in our understanding. Further research proposals are suggested to help further elucidate these mechanisms., (© 2018 Wiley Periodicals, Inc.)

Introduction: Storage phase bladder activity is a counter-intuitive observation of spontaneous contractions. They are potentially an intrinsic feature of the smooth muscle, but interstitial cells in the mucosa and the detrusor itself, as well as other muscular elements in the mucosa may substantially influence them. They are identified in several models explaining lower urinary tract dysfunction., Methods: A consensus meeting at the International Consultation on Incontinence Research Society (ICI-RS) 2017 congress considered the origins and relevance of spontaneous bladder contractions by debating which cell type(s) modulate bladder spontaneous activity, whether the methodologies are sufficiently robust, and implications for healthy and abnormal lower urinary tract function., Results: The identified research priorities reflect a wide range of unknown aspects. Cellular contributions to spontaneous contractions in detrusor smooth muscle are still uncertain. Accordingly, insight into the cellular physiology of the bladder wall, particularly smooth muscle cells, interstitial cells, and urothelium, remains important. Upstream influences, such as innervation, endocrine, and paracrine factors, are particularly important. The cellular interactions represent the key understanding to derive the integrative physiology of organ function, notably the nature of signalling between mucosa and detrusor layers. Indeed, it is still not clear to what extent spontaneous contractions generated in isolated preparations mirror their normal and pathological counterparts in the intact bladder. Improved models of how spontaneous contractions influence pressure generation and sensory nerve function are also needed., Conclusions: Deriving approaches to robust evaluation of spontaneous contractions and their influences for experimental and clinical use could yield considerable progress in functional urology., (© 2018 Wiley Periodicals, Inc.)

Aims: Denervation of the bladder is a detrimental consequence of bladder outlet obstruction (BOO). We have previously shown that, during BOO, inflammation triggered by the NLRP3 inflammasome in the urothelia mediates physiological bladder dysfunction and downstream fibrosis in rats. The aim of this study was to assess the effect of NLRP3-mediated inflammation on bladder denervation during BOO., Methods: There were five groups of rats: (i) Control (no surgery); (ii) Sham-operated; (iii) BOO rats given vehicle; (iv) BOO rats given the NLRP3 inhibitor glyburide; and (v) BOO rats given the IL-1 receptor antagonist anakinra. BOO was constructed by ligating the urethra over a 1 mm catheter and removing the catheter. Medications were given prior to surgery and once daily for 12 days. Bladder sections were stained for PGP9.5, a pan-neuronal marker. Whole transverse sections were used to identify and count nerves while assessing cross-sectional area. For in vitro studies, pelvic ganglion neurons were isolated and treated with IL-1β. After a 48 h incubation apoptosis, neurite length and branching were assessed., Results: In obstructed bladders, the number of nerves decreased while total area increased, indicating a loss of cell number and/or branching. The decrease in nerve density was blocked by glyburide or anakinra, clearly implicating the NLRP3 pathway in denervation. In vitro analysis demonstrated that IL-1β, a product of the inflammasome, induced apoptosis in pelvic ganglion neurons, suggesting one mechanism of BOO-induced denervation is NLRP3/IL-1β triggered apoptosis., Conclusions: The NLRP3/IL-1β-mediated inflammation pathway plays a significant role in denervation during BOO., (© 2017 Wiley Periodicals, Inc.)

The urothelium of the bladder has long been recognized as a protective barrier between detrusor and urine. In recent years, it has become more evident that the urothelium plays a role as an active source of mediators. The urothelium can release neurotransmitters and modulators such as acetylcholine, ATP, nitric oxide, prostaglandins and neuropeptides. They exert both excitatory and inhibitory effects in modulating urinary tract motility. In addition, several studies have reported the existence of an urothelium-derived unknown inhibitory factor in the urinary bladder. By the use of a new serial cascade superfusion bioassay on guinea pig ureter, recent studies confirm that the guinea pig bladder urothelium releases a substance with inhibitory bioactivity, which was resistant to treatment with nitric oxide synthase inhibitor and cyclooxygenase inhibitor and to adenosine A1/A2 receptor blockade. Lately, a marked and quickly inactivated novel release of PGD 2 from the bladder urothelium was discovered, together with localization of prostaglandin D synthase therein. PGD 2 was found to have an inhibitory influence on nerve-induced contractions in guinea pig urinary bladder and on spontaneous contractions in the out-flow region. An altered release of excitatory and inhibitory factors is likely to play an important part in bladder motility disturbances, of which the prostanoids are a notable group. Due to the fact that the bladder is relaxed 99% of the time, not only excitatory mechanisms in the bladder are necessary to study, but also inhibitory mechanisms need considerable attention, which will contribute to the discovery of new targets to treat bladder motility disorders., (© 2017 Nordic Association for the Publication of BCPT (former Nordic Pharmacological Society).)

Ketamine-induced ulcerative cystitis (KIC) initially damaged the bladder mucosa and induced contracted bladder thereafter. Hyaluronan (hyaluronic acid; HA) instillation to the bladder has been used to treat KIC. The present study investigated bladder injury by urothelial defect and HA degeneration and bladder repair by urothelium proliferation and differentiation. This work was based on the hypothesis that HA treatment altered the bladder urothelial layer and the expression of hyaluronan-metabolizing enzymes and/or HA receptors in KIC. Cystometrogram study and tracing analysis of voiding behavior revealed that the ketamine-treated rats exhibited significant bladder hyperactivity with an increase in micturition frequency and a decrease in bladder capacity. The expression of inflammatory and fibrosis markers was also increased in the ketamine-treated group. Moreover, ketamine administration decreased the expression of urothelial barrier-associated protein, altered HA production, and induced abnormal urothelial differentiation, which might attribute to urothelial lining defects. However, HA instillation ameliorated bladder hyperactivity, lessened bladder mucosa damage, and decreased interstitial fibrosis. HA instillation also improved the level of HA receptors (CD44, Toll-like receptor-4, and receptor for HA-mediated motility) and HA synthases 1 to 3 and decreased the expression of hyaluronidases in the urothelial layer of bladder, resulting in enhanced mucosal regeneration. These findings suggested that HA could modulate inflammatory responses, enhance mucosal regeneration, and improve urothelial lining defects in KIC., (Copyright © 2017 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.)

Objectives: To investigate urothelial dysfunction, suburothelial inflammation, and muscarinic receptor expression in diabetic patients with overactive bladder (OAB)., Methods: A total 19 patients with OAB and diabetes mellitus (DM), 14 OAB patients without DM, and 10 healthy control subjects were enrolled in the study. Immunofluorescence staining of E-cadherin, zonula occludens-1 (ZO-1), tryptase (mast cell activation), and apoptosis tests on the bladder urothelium and suburothelium were performed. Tissue muscarinic receptor M2, M3, and purinergic receptor P2X3 levels were measured by Western blotting. Video urodynamic studies were analyzed in relation to immunofluorescence and western blotting results., Results: The mean age of the controls, OAB patients without and with DM were comparable (62.9 ± 6.9, 58.4 ± 21.3, and 68.9 ± 11.3 years, respectively, P = 0.25). E-cadherin and mast cell expression in the bladder urothelium samples of the DM-OAB group and the OAB group without DM differed significantly from those of the control group (all P < 0.05). However, immunofluorescence analyses including E-cadherin, mast cells, apoptotic cell counts, and ZO-1 were comparable between OAB patients with and without DM. In addition, M3 muscarinic protein expression in the bladders of OAB patients with and without DM was significantly higher than that in the control subjects. The video urodynamic parameters did not correlate with the immunofluorescence data, M2 and M3 muscarinic receptor data, or P2X3 protein expression., Conclusion: Urothelial dysfunction and chronic suburothelial inflammation may contribute to the pathogeneses of OAB. However, DM does not aggravate the severity of urothelial inflammation in OAB patients., (© 2016 John Wiley & Sons Australia, Ltd.)

Aims: There are some reports that bladder C-fibers are partially involved in detrusor overactivity in patients with brain lesions. We investigated the contribution of bladder C-fiber to decreased bladder capacity in rats with cerebral infarction., Methods: Cerebral infarction was induced under halothane anesthesia by left middle cerebral artery occlusion with 4-0 nylon thread in female Sprague-Dawley rats. Intramural amounts of ATP and prostaglandin E 2 , in vivo and in vitro ATP, NGF, and prostaglandin E 2 release from the distended bladder urothelium, and changes in mRNA expressions of sensor molecules and receptors were monitored 6 h after the occlusion. Cystometry was performed in rats with or without resiniferatoxin pretreatment., Results: Overexpression of sensor molecule, transient receptor potential vanilloid-type channel 1, acid-sensing ion channel 2, purinergic receptors P2X 3 , and M 2 /M 3 muscarinic receptors was found in the bladder. These changes were accompanied by increases in ATP and NGF release from the urothelium. In contrast, when bladder C-fibers were desensitized by resiniferatoxin, no increase in NGF release from the urothelium was found either in vivo or in vitro. There was no difference in the percentage decrease in bladder capacity between cerebral infarction rats pretreated with resiniferatoxin and cerebral infarction rats without pretreatment., Conclusions: Results indicate that expression of sensor molecules in the bladder is altered by distant infarction in the brain. ATP and NGF release from the urothelium also increased. NGF release was related to activation of bladder C-fibers. Bladder C-fibers might not contribute much to decreased bladder capacity caused by cerebral infarction., (© 2016 Wiley Periodicals, Inc.)

The clinical and financial impact of chronic kidney disease (CKD) is significant, while its progression and prognosis is variable and often poor. Studies using the megabladder (mgb -/- ) model of CKD show that renal urothelium plays a key role in modulating early injury responses following the development of congenital obstruction. The aim of this review is to examine the role that urothelium has in normal urinary tract development and pathogenesis. We discuss normal morphology of renal urothelium and then examine the role that uroplakins (Upks) play in its development. Histologic, biochemical, and molecular characterization of Upk1b RFP/RFP mice indicated Upk1b expression is essential for normal urinary tract development, apical plaque/asymmetric membrane unit (AUM) formation, and differentiation and functional integrity of the renal urothelium. Our studies provide the first evidence that Upk1b is directly associated with the development of congenital anomalies of the urinary tract (CAKUT), spontaneous age-dependent hydronephrosis, and dysplastic urothelia. These observations demonstrate the importance of proper urothelial differentiation in normal development and pathogenesis of the urinary tract and provide a unique working model to test the hypothesis that the complex etiology associated with CKD is dependent upon predetermined genetic susceptibilities that establish pathogenic thresholds for disease initiation and progression.

Objective: To investigate the urothelium function and sensory receptors difference between interstitial cystitis/bladder pain syndrome (IC/BPS) patients with or without Hunner's lesion., Methods: Fourteen female IC/BPS patients with Hunner's lesion (Hunner IC) and 14 age-matched IC/BPS patients without Hunner's lesions (non-Hunner IC) were enrolled. Bladder mucosa biopsies were obtained. Bladder inflammation, eosinophil infiltration, and urothelial denudation were graded on a 4-point scale after staining with hematoxylin and eosin. Adhesive protein E-cadherin, tryptase, and zonula occuldens-1 in the bladder tissues were assessed with immunofluorescence staining. Urothelial muscarinic receptors M2, M3, endothelial nitric oxide synthase (eNOS), and purinergic receptor P2X3 were evaluated by Western blotting., Results: Hunner IC patients had a significantly higher mean visual analog scale pain score and smaller cystometric bladder capacity than non-Hunner IC patients. The Hunner IC bladder specimens showed more severe or moderate eosinophilic infiltration and urothelial denudation than the non-Hunner IC bladder specimens did. The E-cadherin expression was significantly lower, and eNOS expression was significantly higher in the Hunner IC bladder samples than in the non-Hunner IC samples. The other functional proteins or sensory receptors did not differ between groups., Conclusion: Bladder inflammation and urothelial cell adhesion defects were more severe in the Hunner IC than that in the non-Hunner IC patients. eNOS was significantly higher in the Hunner IC than in the non-Hunner IC bladder samples, suggesting that eNOS expression difference may implicate different pathogenesis in 2 types of IC., (Copyright © 2016 Elsevier Inc. All rights reserved.)

The internal face of the detrusor smooth muscle wall of the urinary bladder is covered by a mucosa, separating muscle from the hostile environment of urine. However, the mucosa is more than a very low permeability structure and offers a sensory function that monitors the extent of bladder filling and composition of the urine. The mucosa may be considered as a single functional structure and comprises a tight epithelial layer under which is a basement membrane and lamina propria. The latter region itself is a complex of afferent nerves, blood vessels, interstitial cells and in some species including human beings a muscularis mucosae. Stress on the bladder wall through physical or chemical stressors elicits release of chemicals, such as ATP, acetylcholine, prostaglandins and nitric oxide that modulate the activity of either afferent nerves or the muscular components of the bladder wall. The release and responses are graded so that the mucosa forms a dynamic sensory structure, and there is evidence that the gain of this system is increased in pathologies such as overactive bladder and bladder pain syndrome. This system therefore potentially provides a number of drug targets against these conditions, once a number of fundamental questions are answered. These include how is mediator release regulated; what are the intermediate roles of interstitial cells that surround afferent nerves and blood vessels; and what is the mode of communication between urothelium and muscle - by diffusion of mediators or by cell-to-cell communication?, (© 2016 Nordic Association for the Publication of BCPT (former Nordic Pharmacological Society).)

Objectives: To determine whether protein kinase B (Akt) signalling and secretion of specific downstream effector proteins are abnormal in specific cell fractions of bladder epithelial cells from patients with interstitial cystitis/bladder pain syndrome (IC/BPS), as explanted bladder epithelial cells from patients with IC/BPS produce a frizzled 8-related glycopeptide antiproliferative factor (APF) that inhibits normal bladder epithelial cell proliferation and expression of several proteins known to be regulated by Akt signalling. A related secondary objective was to determine whether treatment of normal bladder epithelial cells with active synthetic asialo-antiproliferative factor (as-APF) induces similar changes in Akt signalling and specific downstream effector proteins/mRNAs., Patients and Methods: Cell proteins were extracted into four subcellular fractions from primary bladder epithelial explants of six patients who fulfilled modified National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) criteria for IC/BPS and six age- and gender-matched controls. Total and/or phosphorylated cellular Akt, glycogen synthase kinase 3β (GSK3β), and β-catenin; total cellular JunB; and secreted matrix metalloproteinase 2 (MMP2) and heparin-binding epidermal growth factor-like growth factor (HB-EGF) levels were determined by Western blot. MMP2, JunB, p53, uroplakin 3 (UPK3), and β-actin mRNAs were quantified by quantitative reverse transcriptase-polymerase chain reaction. Akt activity was determined by nonradioactive assay., Results: IC/BPS cells had lower Akt activity, along with lower Akt ser473- and GSK3β ser9-phosphorylation and higher β-catenin ser33,37/thr41-phosphorylation in specific fractions as compared with matched control cells. IC/BPS explants also had evidence of additional downstream abnormalities compared with control cells, including lower nuclear JunB; lower secreted MMP2 and HB-EGF; plus lower MMP2, JunB, and UPK3 mRNAs but higher p53 mRNA relative to β-actin. Each of these IC/BPS cell abnormalities was also induced in normal cells by as-APF., Conclusion: These findings indicate that IC/BPS cells have abnormal Akt activity with downstream protein expression abnormalities including decreased MMP2 and HB-EGF secretion. They also support the hypothesis that APF plays a role in the pathogenesis of IC/BPS via its effects on cell Akt signalling and HB-EGF production., (Published 2016. This article is a U.S. Government work and is in the public domain in the USA.)

Aims: Diabetic bladder dysfunction (DBD) has been extensively studied in animal models of type 1 diabetes. We aimed to examine the functional and morphological alterations of the urinary bladder in a type 2 diabetes model, FVB(db/db) mice., Methods: FVB(db/db) mice and age-matched FVB/NJ control mice were tested at either 12, 24 or 52weeks of age. Body weight, blood glucose and glycated hemoglobin (HbA1c) levels were measured. Bladder function was assessed by measurement of 24-h urination behavior and conscious cystometry. Bladder was harvested for Masson's Trichrome staining and morphometric analysis., Results: The body weights of FVB(db/db) mice were twice as those of FVB/NJ control mice. The blood glucose and HbA1c levels were higher in FVB(db/db) mice at 12 and 24weeks, but not at 52weeks. A significant increase in the mean volume per void, but decrease in the voiding frequency, in FVB(db/db) mice was observed. Cystometry evaluation showed increased bladder capacity, voided volume, and peak micturition pressure in FVB(db/db) mice compared with FVB/NJ mice. Morphometric analysis revealed a significant increase in the areas of detrusor muscle and urothelium in FVB(db/db) mice. In addition, some FVB(db/db) mice, especially males at 12 and 24weeks, showed small-volume voiding during 24-h urination behavior measurement, and detrusor overactivity in the cystometry measurement., Conclusions: The FVB(db/db) mouse, displaying DBD characterized by not only increased bladder capacity, void volume, and micturition pressure, but also bladder overactivity, is a useful model to further investigate the mechanisms of type 2 diabetes-related bladder dysfunction., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Aims: To investigate urothelial dysfunction and suburothelial inflammation in patients with chronic SCI at different spinal cord levels., Methods: Immunofluorescence staining of E-cadherin, zonula occludens-1 (ZO-1), tryptase (mast cell activation), and apoptosis tests on bladder biopsy specimens including urothelium and suburothelium were performed in 34 chronic SCI patients and 10 controls. Video-urodynamic studies were also analyzed and correlated with immunofluorescence findings., Results: The mean interval from SCI to bladder biopsy was 9.3 ± 8.4 years. Patients with chronic SCI had significantly lower expression of E-cadherin (20.86 ± 14.07 vs. 42.40 ± 16.73, the fluorescence intensity per 4 µm(2)) and ZO-1 (5.54 ± 3.73 vs. 11.01 ± 5.66, the fluorescence intensity per 4 µm(2)) than controls (both P < 0.05). Additionally, suburothelial activated mast cells (16.60 ± 6.85 vs. 1.25 ± 1.15, positive cells per 100 cells) and apoptotic cell numbers (5.39 ± 4.86 vs. 0.08 ± 0.26, positive cells per 100 cells) were significantly higher than in controls (both P < 0.05). Immunofluorescence characteristics and video-urodynamic findings did not differ between patients with 15 cervical and 19 thoracic SCIs. Suburothelial activated mast cell numbers correlated negatively to E-cadherin expression in the urothelium (r = -0.559, P < 0.05). Additionally, apoptotic cell number correlated negatively with cystometric bladder capacity (r = -0.535, P < 0.05)., Conclusions: Decreased expression of urothelial adhesion and junction proteins and increased suburothelial inflammation and apoptosis were found in patients with chronic SCI, regardless of injury level. Such mechanisms might contribute to the vulnerability of patients with SCI to cystitis and recurrent bacterial infections., (© 2014 Wiley Periodicals, Inc.)

Introduction: This study investigated the mRNA expression pattern and distribution of 5-hydroxytryptamine (5-HT) receptors 5-HT2A, 5-HT2B, 5-HT3A, 5-HT4, and 5-HT7 within the urothelium and detrusor of normal bladder tissue and in the urothelium of bladders from patients with benign prostatic hyperplasia (BPH)., Methods: Normal urinary bladder specimens were obtained from 13 patients undergoing radical cystectomy due to bladder cancer (normal group) and BPH specimens were obtained from 27 benign prostatic obstruction patients receiving transurethral prostatectomy or retropubic prostatectomy. Receptor subtype mRNA expression was determined by real-time reverse transcription polymerase chain reaction on urothelium, detrusor, and whole mucosal preparations. Receptor distribution was determined by immunohistochemistry., Results: In normal tissues, expressions of 5-HT2B and 5-HT7 receptor mRNAs in the urothelium, detrusor, and whole mucosa were greater than the average expression for all receptor subtype mRNAs. 5-HT2B receptor protein was distributed in the apical urothelium and among the detrusor smooth muscle layers. In contrast, the 5-HT7 receptors were within the urothelium middle cell layers and detrusor smooth muscle cells. The expression pattern of each 5-HT receptor subtype mRNA within the BPH urothelium was similar to that in the normal urothelium. The expression level of 5-HT2A receptor mRNA in the BPH group was significantly lower than the normal group; however, the expressions of both 5-HT3A and 5-HT7 mRNAs were significantly higher. The expressions of both 5-HT2B and 5-HT4 mRNAs were not significantly different between the normal and BPH groups., Conclusion: In normal urinary bladders, the expressions of both 5-HT2B and 5-HT7 mRNAs were higher compared to the 5-HT2A, 5-HT3A, and 5-HT4 mRNAs. The distributions of 5-HT2B and 5-HT7 receptors were different in the urothelium and detrusor layers. The 5-HT3A and 5-HT7 receptor mRNAs in the BPH group were significantly higher compared to the normal urothelium, while the 5-HT2A mRNA was significantly lower., Funding: Asahi Kasei Pharma Corporation.

Ketamine abusers develop severe lower urinary tract symptoms. The major aims of the present study were to elucidate ketamine-induced ulcerative cystitis and bladder apoptosis in association with oxidative stress mediated by mitochondria and the endoplasmic reticulum (ER). Sprague-Dawley rats were distributed into three different groups, which received normal saline or ketamine for a period of 14 or 28 days, respectively. Double-labeled immunofluorescence experiments were performed to investigate tight junction proteins for urothelial barrier functions. A TUNEL assay was performed to evaluate the distribution of apoptotic cells. Western blot analysis was carried out to examine the expressions of urothelial tight junction proteins, ER stress markers, and apoptosis-associated proteins. Antioxidant enzymes, including SOD and catalase, were investigated by real-time PCR and immunofluorescence experiments. Ketamine-treated rats were found to display bladder hyperactivity. This bladder dysfunction was accompanied by disruptions of epithelial cadherin- and tight junction-associated proteins as well as increases in the expressions of apoptosis-associated proteins, which displayed features of mitochondria-dependent apoptotic signals and ER stress markers. Meanwhile, expressions of mitochondria respiratory subunit enzymes were significantly increased in ketamine-treated bladders. Conversely, mRNA expressions of the antioxidant enzymes Mn-SOD (SOD2), Cu/Zn-SOD (SOD1), and catalase were decreased after 28 days of ketamine treatment. These results demonstrate that ketamine enhanced the generation of oxidative stress mediated by mitochondria- and ER-dependent pathways and consequently contributed to bladder apoptosis and urothelial lining defects. Such oxidative stress-enhanced bladder cell apoptosis and urothelial barrier defects are potential factors that may play a crucial role in bladder overactivity and ulceration., (Copyright © 2015 the American Physiological Society.)

Objectives: To analyze the urothelial responses to mitomycin C treatment after urethral injury in rats, as the urothelium might play a role in the pathogenesis of urethral stricture., Methods: Male Sprague-Dawley rats were divided into four groups (n = 5/group): negative control, positive control without further treatment, experimental control treated with sodium hyaluronate and sodium carboxymethylcellulose, and experimental treated with mitomycin C after internal urethrotomy., Results: Compared with negative controls, positive controls showed a significant increase in cell proliferation and DNA damage accompanied by a considerable decrease in DNA repair in the urothelium, which resulted in urethral stricture. Experimental controls showed a significant increase in cell proliferation, DNA damage and DNA repair compared with negative controls. The mitomycin C-treated group showed a significant decrease in cell proliferation and DNA damage, but a considerable increase in DNA repair compared with the positive and experimental control groups. DNA damage was immediately increased after urethral injury, but DNA repair and cell proliferation showed belated and upregulated expression after mitomycin C treatment., Conclusions: Mitomycin C could induce healthy re-epithelialization without severe damage in the urothelium. This finding might support the possibility of using mitomycin C as an adjuvant therapy for urethral strictures, and it might also suggest a urothelial role in the process of urethral stricture after urethral injury., (© 2015 The Japanese Urological Association.)

Objective: Lower urinary tract symptoms (LUTS) are common in various bladder disorders. This study investigated urothelial dysfunction and chronic inflammation in the urothelium in different types of lower urinary tract dysfunction (LUTD), which causes bladder storage symptoms., Methods: Bladder tissues were obtained from patients with LUTD including 17 with interstitial cystitis/bladder pain syndrome (IC/BPS), 15 with bladder outlet obstruction (BOO), 12 with spinal cord injury (SCI), 12 with recurrent urinary tract infection (UTI), 13 with ketamine related cystitis (KC) and 10 controls. The bladder specimens were investigated using immunofluorescence (IF) staining of the urothelial junction protein E-cadherin and the TUNEL assay for urothelial apoptosis. Mast cell activation was also measured by IF using tryptase for mucosal inflammation. Statistical analysis was performed using the Kruskal-Wallis and Wilcoxon rank-sum test and P-values less than 0.05 were considered significant., Results: Highly significant increases of mast cell infiltration were observed in patients with KC (7.8 ± 3.7), IC/BPS (4.6 ± 3.0), recurrent UTI (2.4 ± 1.2), SCI (3.7 ± 2.7), and BOO (5.1 ± 2.0) compared with controls (1.3 ± 1.2) (all p < 0.05). Statistically significant increases of apoptotic cells were observed in patients with KC (4.2 ± 1.5), IC/BPS (2.4 ± 1.7), SCI (2.4 ± 1.4), recurrent UTI (1.9 ± 2.4), and BOO (1.2 ± 1.1) compared with controls (0.08 ± 0.3) (all p < 0.05). Significantly decreased expression of E-cadherin in patients with IC/BPS (25.1 ± 16.3), KC (11.0 ± 11.3), and recurrent UTI (26.2 ± 5.0) was found compared to controls (42.4 ± 16.7) and patients with SCI (44.4 ± 18.8) or BOO (42.8 ± 14.3) (all P < 0.05)., Conclusion: Increased urothelial inflammation and urothelial cell apoptosis seem to share common pathophysiologies of various LUTDs that cause similar bladder symptoms., (© 2014 Wiley Publishing Asia Pty Ltd.)

Storage dysfunction of the urinary bladder, specifically overactive bladder syndrome, is a condition that occurs frequently in the general population. Historically, pathophysiological and treatment concepts related to overactive bladder have focused on smooth muscle cells. Although these are the central effector, numerous anatomic structures are involved in their regulation, including the urothelium, afferent and efferent nerves, and the central nervous system. Each of these structures involves receptors for—and the urothelium itself also releases—many mediators. Moreover, hypoperfusion, hypertrophy, and fibrosis can affect bladder function. Established treatments such as muscarinic antagonists, β-adrenoceptor agonists, and onabotulinumtoxinA each work in part through their effects on the urothelium and afferent nerves, as do α1-adrenoceptor antagonists in the treatment of voiding dysfunction associated with benign prostatic hyperplasia; however, none of these treatments are specifically targeted to the urothelium and afferent nerves. It remains to be explored whether future treatments that specifically act at one of these structures will provide a therapeutic advantage.

Urinary incontinence remains an important clinical problem worldwide, having a significant socio-economic, psychological, and medical burden. Maintaining urinary continence and coordinating micturition are complex processes relying on interaction between somatic and visceral elements, moderated by learned behavior. Urinary viscera and pelvic floor must interact with higher centers to ensure a functionally competent system. This article aims to describe the relevant anatomy and neuronal pathways involved in the maintenance of urinary continence and micturition. Review of relevant literature focusing on pelvic floor and urinary sphincters anatomy, and neuroanatomy of urinary continence and micturition. Data obtained from both live and cadaveric human studies are included. The stretch during bladder filling is believed to cause release of urothelial chemical mediators, which in turn activates afferent nerves and myofibroblasts in the muscosal and submucosal layers respectively, thereby relaying sensation of bladder fullness. The internal urethral sphincter is continuous with detrusor muscle, but its arrangement is variable. The external urethral sphincter blends with fibers of levator ani muscle. Executive decisions about micturition in humans rely on a complex mechanism involving communication between several cerebral centers and primitive sacral spinal reflexes. The pudendal nerve is most commonly damaged in females at the level of sacrospinous ligament. We describe the pelvic anatomy and relevant neuroanatomy involved in maintaining urinary continence and during micturition, subsequently highlighting the anatomical basis of urinary incontinence. Comprehensive anatomical understanding is vital for appropriate medical and surgical management of affected patients, and helps guide development of future therapies., (© 2014 Wiley Periodicals, Inc.)

Objectives: To investigate the effect of diabetes on urothelial modulation of bladder contractility., Methods: Bladder strips (urothelium intact or denuded) were prepared from 8-week-old streptozotocin-induced diabetic (n = 19) and non-diabetic control rats (n = 10). The effect of modulators of MaxiK (iberiotoxin and tetraethylammonium) and Kv7 (XE991 and retigabine) potassium channel activity were investigated for their effects on both carbachol-induced force generation and spontaneous contractile activity., Results: In bladder strips from non-diabetic animals, the presence of the urothelium resulted in marked sensitivity to carbachol-induced force generation by modulators of MaxiK and Kv7 channel activity, whereas in the diabetic animal urothelial sensitivity to these agents was significantly diminished. Urothelial-intact bladder strips from non-diabetic animals were more sensitive to modulators of Kv7 activity in reducing the amplitude of spontaneous phasic contractions than urothelial-denuded bladder strips, whereas in diabetic animals the presence or absence of the urothelium did not alter the sensitivity to modulators of Kv7 activity. Spontaneous activity in the presence of tetraethylammonium was not affected by the urothelium in bladder strips from either diabetic or non-diabetic animals., Conclusions: The presence of the urothelium in bladders from non-diabetic animals modulates the activity of potassium blockers to affect bladder contractility, whereas in the diabetic bladder this effect is attenuated. These findings could help to explain the lack of success of pharmaceutical treatments targeting potassium channels to treat bladder pathology in patients with diseases imparing urothelial function., (© 2014 The Japanese Urological Association.)

There is abundant evidence that the lower urinary tract (LUT) mucosal layer is involved both in mechanosensory functions that regulate bladder contractile activity and in urethral sensation. Changes to the mucosa can be associated with a number of bladder pathologies. For example, alterations of the urothelium and underlying lamina propria at both the molecular and structural levels have been reported in both patients and animals associated with disorders such as bladder pain syndrome and diabetic cystopathy. In contrast to the urinary bladder, much less is known about the urothelium/lamina propria of the bladder neck/proximal urethra. There are important gender differences in the outflow region both anatomically and with respect to innervation, hormonal sensitivity, and location of the external urethral sphincter. There is reasonable evidence to support the view that the mucosal signaling pathway in the proximal urethra is important for normal voiding, but it has also been speculated that the proximal urethra can initiate bladder overactivity. When dysfunctional, the proximal urethra may be an interesting target, for example, botulinum toxin injections aiming at eliminating both urgency and incontinence due to detrusor overactivity., (© 2014 Wiley Periodicals, Inc.)

A hallmark of functional pain syndromes, such as bladder pain syndrome/interstitial cystitis (BPS/IC) is pain in the absence of demonstrable infection or pathology of the viscera or associated nerves. There are no clear definitions of this syndrome, no proven etiologies and no effective treatments able to eradicate the symptoms. This condition is characterized by suprapubic pain, associated with bladder filling and can also be accompanied by a persistent strong desire to void, increased frequency of urination and nocturia. Severe cases of this disorder, which affects primarily women, can have considerable impact on the quality of life of patients due to extreme pain and urinary frequency, which are often difficult to treat. In addition, BPS/IC patients may also suffer co-morbid conditions where pain is a common symptom (such as irritable bowel syndrome, fibromyalgia). Theories explaining the pathology of bladder pain syndrome are many and include an altered bladder lining and possible contribution of a bacterial agent., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Introduction: Interstitial cystitis (IC) or bladder pain syndrome (BPS) is defined as supra-pubic pain related to bladder filling. IC is characterized by a particular symptom complex with no identifiable causes; as with bladder hypersensitivity it is usually associated with urinary frequency and urgency with bladder pain. No current treatments have a significant impact on symptoms over time., Areas Covered: This systematic review examines the pharmacokinetic aspects and adverse event of present IC therapy to highlight appropriate treatment to improve the symptoms of IC. This article reviews material obtained via Medline, PubMed, and EMBASE literature searches up to October 2013., Expert Opinion: The correct approach to IC should consider a multidisciplinary team of specialists and a multimodal treatment package that include psychotherapy, behavior change, physical activation, and analgesic treatment. Unfortunately, a single therapeutic target for IC is not yet known. With regard to pathophysiology and therapy, there is more to discover. The first insult damages the bladder urothelium, hence vehicles that lead the drug to penetrate the wall of the bladder might be a novel strategic approach.

High mobility group box 1 (HMGB1), one of damage-associated molecular patterns (DAMPs), plays roles in not only inflammation but also processing of somatic pain. Given that no evidence for roles of HMGB1 in visceral pain signaling is available, we asked if HMGB1 participates in bladder pain accompanying cystitis caused by cyclophosphamide in mice, using the anti-HMGB1 neutralizing antibody and recombinant human soluble thrombomodulin (rhsTM) that sequesters HMGB1 and promotes its degradation by thrombin. Cyclophosphamide, administered i.p., caused bladder pain-like nociceptive behavior and referred hyperalgesia accompanying cystitis symptoms including increased bladder weight, an indicator of edema, in mice. The cyclophosphamide-induced bladder pain and referred hyperalgesia, but not increased bladder weight, were prevented by i.p. preadministration of the anti-HMGB1 neutralizing antibody or rhsTM. HMGB1, given i.p., facilitated the bladder pain and referred hyperalgesia caused by a subeffective dose of cyclophosphamide, an effect blocked by rhsTM. In the cyclophosphamide-treated mice, HMGB1 levels greatly decreased in the bladder tissue, particularly in the urothelial cells, but did not change in the plasma. Low molecular weight heparin, known to inhibit the receptor for advanced glycation end products (RAGE), but not lipopolysaccharide from Rhodobacter sphaeroides, an inhibitor of toll-like receptor 4 (TLR4), blocked the cyclophosphamide-induced bladder pain and referred hyperalgesia. Thus, our data indicate involvement of HMGB1 in the cyclophosphamide-induced bladder pain signaling, but not cystitis itself, and suggest that targeting HMGB1 with rhsTM or blocking RAGE might serve as a novel therapeutic strategy for the management of bladder pain., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

This study aimed to develop optimal gelatin-based mucoadhesive nanocomposites as scaffolds for intravesical gene delivery to the urothelium. Hydrogels were prepared by chemically crosslinking gelatin A or B with glutaraldehyde. Physicochemical and delivery properties including hydration ratio, viscosity, size, yield, thermosensitivity, and enzymatic degradation were studied, and scanning electron microscopy (SEM) was carried out. The optimal hydrogels (H), composed of 15% gelatin A175, displayed an 81.5% yield rate, 87.1% hydration ratio, 42.9 Pa·s viscosity, and 125.8 nm particle size. The crosslinking density of the hydrogels was determined by performing pronase degradation and ninhydrin assays. In vitro lentivirus (LV) release studies involving p24 capsid protein analysis in 293T cells revealed that hydrogels containing lentivirus (H-LV) had a higher cumulative release than that observed for LV alone (3.7-, 2.3-, and 2.3-fold at days 1, 3, and 5, resp.). Lentivirus from lentivector constructed green fluorescent protein (GFP) was then entrapped in hydrogels (H-LV-GFP). H-LV-GFP showed enhanced gene delivery in AY-27 cells in vitro and to rat urothelium by intravesical instillation in vivo. Cystometrogram showed mucoadhesive H-LV reduced peak micturition and threshold pressure and increased bladder compliance. In this study, we successfully developed first optimal gelatin-based mucoadhesive nanocomposites as intravesical gene delivery scaffolds.

A new study by Xu et al. presents compelling evidence for an important role of the glomerular endothelium in acute kidney injury. They show that lipopolysaccharide reduces the endothelial surface layer, resulting in mild albuminuria, reduced glomerular filtration rate, and fewer endothelial fenestrae. Tumor necrosis factor-α (TNF-α) is identified as instrumental in these lipopolysaccharide effects through the TNF-α type 1 receptor. The study highlights that the glomerular endothelium has a key role in the maintenance of the glomerular filtration barrier.

Severe sepsis is often accompanied by acute kidney injury (AKI) and albuminuria. Here we studied whether the AKI and albuminuria associated with lipopolysaccharide (LPS) treatment in mice reflects impairment of the glomerular endothelium with its associated endothelial surface layer. LPS treatment decreased the abundance of endothelial surface layer heparan sulfate proteoglycans and sialic acid, and led to albuminuria likely reflecting altered glomerular filtration permselectivity. LPS treatment decreased the glomerular filtration rate (GFR), while also causing significant ultrastructural alterations in the glomerular endothelium. The density of glomerular endothelial cell fenestrae was 5-fold lower, whereas the average fenestrae diameter was 3-fold higher in LPS-treated than in control mice. The effects of LPS on the glomerular endothelial surface layer, endothelial cell fenestrae, GFR, and albuminuria were diminished in TNF receptor 1 (TNFR1) knockout mice, suggesting that these LPS effects are mediated by TNF-α activation of TNFR1. Indeed, intravenous administration of TNF decreased GFR and led to loss of glomerular endothelial cell fenestrae, increased fenestrae diameter, and damage to the glomerular endothelial surface layer. LPS treatment decreased kidney expression of vascular endothelial growth factor (VEGF). Thus, our findings confirm the important role of glomerular endothelial injury, possibly by a decreased VEGF level, in the development and progression of AKI and albuminuria in the LPS model of sepsis in the mouse.