The detrusor muscle: an innocent victim of bladder outlet obstruction

Persistent Lower Urinary Tract Symptoms After BPH Surgery

PURPOSE OF REVIEW

Lower urinary tract symptoms (LUTS) after surgical management for BPH pose a significant clinical challenge for urologists. Despite high success rates in relieving LUTS, there is a subset of patients who experience persistent symptoms after intervention. In this review article, we describe the management of patients with new or persistent LUTS after endoscopic bladder outlet surgery.

RECENT FINDINGS

Previously, the goal for BPH management was to remove as much adenomatous tissue as possible. While potentially effective, this may lead to unwanted side effects. There has been a recent paradigm shift for new minimally invasive surgical therapies (MIST) that strategically treat adenomatous tissue, adding potential complexity in managing patients with new or residual symptoms in the postoperative setting. There is a paucity of literature to guide optimal workup and care of patients with persistent LUTS after surgical management. We characterize patients into distinct groups, defined by types of symptoms, irritative versus obstructive, and timing of the symptomatology, short term versus long term. By embracing this patient-centered approach with shared decision management, clinicians can optimize outcomes efficiently improving their patients' quality of life.

Advancing Holmium Laser Enucleation of the Prostate Outcomes Reporting: An Assessment of Patient-Reported Outcomes in the Literature

Holmium laser enucleation of the prostate (HoLEP) is a size-independent option for benign prostatic hyperplasia surgical management. Since lower urinary tract symptoms (LUTS) are a quality-of-life issue, studies should prioritize patient-reported outcomes (PROs). This HoLEP review assesses PROs inclusion in the top 20 cited HoLEP studies and defines their limitations. PROs were categorized by domain: LUTS, incontinence, sexual function, pain, hematuria, and patient satisfaction. On review, no top-cited study included all PRO domains. The nuanced patient experience after HoLEP could be better defined via standardized utilization of validated PROs, while also improving comparability between HoLEP studies.

Single-cell transcriptomics reveal the remodeling landscape of bladder in patients with obstruction-induced detrusor underactivity

Detrusor underactivity (DUA) is a common and thorny problem in urology, which severely impairs patients' bladder function and quality of life. However, its underlying pathophysiological mechanism remains unclear. Hence, we sequenced 69,973 cells from five controls and nine patients with bladder dysfunction using single-cell RNA sequencing. Twelve distinct cell types were identified and they showed high cellular and functional heterogeneity among each group. Among them, fibroblasts, macrophages, and epithelial cells had the most intercellular communications. Their aberrant gene expressions and altered intercellular interactions were mainly involved in extracellular matrix organization, inflammation/immune regulation, and cellular injury. Further re-cluster analysis revealed an accumulation of the RBFOX1+ fibroblasts and RIPOR2+ macrophages in dysfunctional bladder wall, which mediated bladder remodeling through dysfunctional extracellular matrix organization and inflammation/immune reaction. Besides, the subtype of the epithelial cells was significantly altered. They underwent an intricate process including inflammation, damage, and repair during bladder remodeling. Overall, this work constructed the first single-cell atlas for obstruction-induced DUA, which could provide a valuable resource for deciphering the cellular heterogeneity and function changes in DUA, as well as potential strategies for bladder function improvement.

Is there a best timing for benign prostatic hyperplasia surgery?

INTRODUCTION

Treatment of lower urinary tract symptoms (LUTS) related to benign prostatic hyperplasia (BPH) has shifted over the last decades, with medical therapy becoming the primary treatment modality while surgery is being reserved mostly to patients who are not responding to medical treatment or presenting with complications from BPH. Here, we aim to to discuss the optimal timing of surgical management of LUTS/BPH.

MATERIALS AND METHODS

A literature search was conducted on Pub-Med/MEDLINE database to identify reports published from January 1990 until January 2022 by combining the following MeSH terms: "Lower Urinary Tract Symptoms"; "Prostatic Hyperplasia"; "Prostatic Hyperplasia/therapy"; "Prostatic Hyperplasia/complications"; "Treatment Outcome"; "Time-to-Treatment". Evidence supporting or not early surgical treatment of BPH was examined and reported in a pros and cons form.

RESULTS

The "pro early surgery" highlighted the superior efficacy and cost-effectiveness of surgery over medical treatment for BPH, as well as the possibility of worse postoperative outcomes for delayed surgical treatment. The "con early surgery" considered that medical therapy is efficient in well-selected patients and can avoid the serious risks inherent to surgical treatment of BPH including important sexual side effects.

CONCLUSIONS

Clinical trials comparing the outcomes for prolonged medical therapy versus early surgical treatment could determine which approach is more beneficial in the long-term in context of the aging population. Until then, both approaches have their advantages and patients should be involved in the treatment decision.

Circulating exosomal miR-16-5p and let-7e-5p are associated with bladder fibrosis of diabetic cystopathy

Diabetic cystopathy (DCP) is a prevalent etiology of bladder dysfunction in individuals with longstanding diabetes, frequently leading to bladder interstitial fibrosis. Research investigating the initial pathological alterations of DCP is notably scarce. To comprehend the development of fibrosis and find effective biomarkers for its diagnosis, we prepared streptozotocin-induced long-term diabetic SD rats exhibiting a type 1 diabetes phenotype and bladder fibrosis in histology detection. After observing myofibroblast differentiation from rats' primary bladder fibroblasts with immunofluorescence, we isolated fibroblasts derived exosomes and performed exosomal miRNA sequencing. The co-differentially expressed miRNAs (DEMis) (miR-16-5p and let-7e-5p) were screened through a joint analysis of diabetic rats and long-term patients' plasma data (GES97123) downloaded from the GEO database. Then two co-DEMis were validated by quantitative PCR on exosomes derived from diabetic rats' plasma. Following with a series of analysis, including target mRNAs and transcription factors (TFs) prediction, hubgenes identification, protein-protein interaction (PPI) network construction and gene enrichment analysis, a miRNA-mediated genetic regulatory network consisting of two miRNAs, nine TFs, and thirty target mRNAs were identified in relation to fibrotic processes. Thus, circulating exosomal miR-16-5p and let-7e-5p are associated with bladder fibrosis of DCP, and the crucial genes in regulatory network might hold immense significance in studying the pathogenesis and molecular mechanisms of fibrosis, which deserves further exploration.

Comparison between combination of tamsulosin and Pentoxifylline versus tamsulosin alone in the treatment of lower urinary tract symptoms due to benign prostate hyperplasia: A preliminary study

BACKGROUND

In older adults, bladder outlet obstruction (BOO) is prevalent, primarily due to benign prostatic hyperplasia (BPH). These patients' lower urinary tract symptoms can be treated surgically and with medical therapy. Compared to standard treatment with tamsulosin, Pentoxifylline, a phosphodiesterase inhibitor, could benefit patients with BOO due to its properties on microcirculatory blood flow and oxygenation of ischemic tissues. Hence, this trial intended to study the efficacy of Pentoxifylline combined with tamsulosin in treating BOO patients.

MATERIALS AND METHODS

This randomized, double-blind clinical trial recruited 60 patients with BPH from a single center in 2022. Upon consent of patients meeting the eligibility criteria, they were randomly allocated to intervention (Pentoxifylline + tamsulosin) and control (placebo + tamsulosin) groups. The patients were evaluated for international prostate symptom score (IPSS), quality of life (QoL), maximum urinary flow rate (Qmax ) by uroflowmetry, and post-void residual volume (PVR) by abdominal sonography at the onset of the study and after the 12th week.

RESULTS

Patients who used the combination therapy had significantly better results of prostate symptoms and quality of life improvement (IPSS: -36.6%, QoL: -45.3%) compared to patients who received tamsulosin alone (IPSS: -21.2%, QoL: -27.7%) (p < .001). Also, this study shows that the improvement in maximum urinary flow rate and residual volume by combination therapy is significantly higher (Qmax : +42.5%, PVR: -42.6%) compared to monotherapy (Qmax : +25.1%, PVR: -26.1%) (p < .001).

CONCLUSION

When combined with tamsulosin, Pentoxifylline could significantly improve the lower urinary symptoms of BPH patients. It is well tolerated, and the treatment outcomes are better in patients who receive the combination of Pentoxifylline and tamsulosin than those who only receive tamsulosin.

Modeling study of the effect of placebo and medical therapy on storage and voiding symptoms, nocturia, and quality of life in men with prostate enlargement at risk for progression

BACKGROUND

Modeling studies using large datasets from men with lower urinary tract symptoms/benign prostate enlargement (LUTS/BPE) can predict changes in International Prostate Symptom Score (IPSS) and risk of acute urinary retention/surgery under different treatment regimens and according to predictors (baseline characteristics) that commonly define risk of progression. We assessed the impact of treatments on different symptom types (storage, voiding, and nocturia), quality of life (QoL; IPSS Q8), and BPH Impact Index [BII]).

METHODS

Generalized least squares models were used to predict each outcome. Data from the CombAT study were used to predict outcomes for active treatments (dutasteride, tamsulosin, combination therapy). Predictors included: age; IPSS total, storage, voiding, nocturia and QoL (IPSS Q8) scores; BII; prostate volume; maximum urine flow rate (Qmax), prostate-specific antigen, postvoid residual urine (PVR); alpha-blocker usage within 12 months. Data from phase III dutasteride monotherapy studies were used to predict placebo outcomes. Results were visualized using an interactive web-based tool ( www.bphtool.com ).

RESULTS

Combination therapy provided greater predicted benefit than either monotherapy for all five outcomes for most patient profiles within the CombAT inclusion criteria. PVR and corresponding subscores were significant predictors of change in both storage and voiding subscores. Alpha-blocker use within 12 months, age (storage subscore), and Qmax (voiding subscore) were also significant predictors. PVR, age, Qmax, and nocturia score were significant predictors of change in nocturia. PVR, Qmax, previous alpha-blocker use, total IPSS, and QoL (IPSS Q8) score were significant predictors of change in QoL (IPSS Q8) score. For BII, significant predictors were PVR, age, total IPSS, and BII score. The multivariable effect of covariates and treatments is best visualized through the interactive web-based tool.

CONCLUSIONS

This predictive modeling study informs our understanding of how risk factors for disease progression interact and affect treatment impact on different symptom types and QoL scores.

Intradetrusor OnabotulinumtoxinA Injections at the Time of Holmium Laser Enucleation of the Prostate for Men with Severe Storage Symptoms

Introduction: Intradetrusor onabotulinumtoxinA (OTA) injection is a well-established treatment option for refractory overactive bladder; however, its use at the time of holmium laser enucleation of the prostate (HoLEP) for men with bladder outlet obstruction (BOO) and severe storage symptoms has not been previously reported. Materials and Methods: We retrospectively identified men with BOO and severe storage symptoms who underwent treatment with 200 U of intradetrusor OTA (Botox®) at the time of HoLEP. Patients were propensity score matched to a cohort of HoLEP-only patients based on age, Michigan Incontinence Symptom Index (M-ISI) score, preoperative urinary retention, urge incontinence, and prostate size. Perioperative, postoperative, and patient-reported outcomes were examined between groups. Results: We identified 82 men who underwent HoLEP, including 41 patients in the OTA group and 41 patients in the control group. There was no difference in operative times (59 minutes OTA vs 55 minutes control, p = 0.2), rates of same-day trial of void (TOV) (92% OTA vs 94% control, p = 0.7), or rates of same-day discharge (88% OTA vs 85% control, p = 0.6) between groups. There was no difference in temporary postoperative urinary retention (7% OTA vs 2% control, p = 0.3) between groups. Patients who received OTA injections had a significant reduction in their incontinence scores at 3-month follow-up (M-ISI -8, interquartile range [IQR]: -13 to 0, p < 0.001), whereas control patients did not (M-ISI -5, IQR: -8 to -1, p = 0.2). There was no difference in rates of 90-day complications between groups (OTA 10% vs control 5%, p = 0.7). Conclusions: Intradetrusor OTA at the time of HoLEP is safe and is associated with improved urinary incontinence scores and AUA Symptom Score. Rates of same-day discharge and same-day TOV after HoLEP were not affected by OTA. These findings support the role of OTA as an adjunct to surgical intervention in men with incontinence in the presence of BOO.

The application of "S.I.S" technique improves long-term continence after robotic radical prostatectomy

AIMS

To propose a novel S.I.S technique during the robotic-assisted radical prostatectomy (RARP), encompassing pubourethral suspension, posterior wall intensification, and bladder neck stripping, and to present functional and oncological outcomes with a special focus on long-term continence.

METHODS

From January 1, 2018, to December 31, 2019, consecutive patients who underwent RARP were retrospectively investigated and separated into the S.I.S group and the conventional group. Preoperative patient characteristics, tumor status, and perioperative parameters were collected, followed by the assessment of self-reported status on continence, using an International Consultation on Incontinence Modular Questionnaire-urinary incontinence short form (ICIQ-UI-SF). Statistical comparisons were performed on variables between the two surgery groups, and multivariate logistic regression analysis was used to determine predictive factors for postoperative incontinence severity.

RESULTS

A total of 602 subjects were analyzed with a median follow-up of 24 months. There was no significant difference regarding baseline characteristics and perioperative parameters, except for a more advanced tumor stage in the S.I.S group. The application of the S.I.S technique did not jeopardize the positive surgical margin rate at the bladder neck or long-term tumor control. Notably, the patient-reported degree of incontinence was significantly reduced with the assistance of S.I.S technique, as evidenced by the diminished severe-to-very severe cases. On multivariate analysis, both preoperative body mass index and use of S.I.S modification were independent predictive factors for the long-term incontinence severity.

CONCLUSIONS

The application of S.I.S technique during RARP is feasible and superior compare with the conventional approach, with a significantly alleviated long-term incontinence severity, without compromising cancer control.

Impact of the bladder detrusor muscular ring on lower urinary tract symptoms due to benign prostatic hyperplasia: A quantitative MRI analysis

BACKGROUND

The etiology of lower urinary tract symptoms secondary to benign prostatic hyperplasia (LUTS/BPH) remains uncertain.

OBJECTIVE

The purpose of our study was to quantitatively analyze anatomic characteristics on magnetic resonance imaging (MRI) to assess novel independent factors for symptoms.

METHODS

This retrospective single-institution study evaluated treatment-naïve men who underwent prostate MRI within 3 months of international prostate symptom score (IPSS) scoring from June 2021 to February 2022. Factors measured on MRI included: size of the detrusor muscular ring (DMR) surrounding the bladder outlet, central gland (CG) mean apparent diffusion coefficient (ADC), levator hiatus (LH) volume, intrapelvic volume, intravesicular prostate protrusion (IPP) volume, CG volume, peripheral zone (PZ) volume, prostate urethra angle (PUA), and PZ background ordinal score. Multivariable logistic regression and receiver operating characteristic analysis were used to analyze factors for moderate/severe (IPSS ≥ 8) and severe LUTS/BPH (IPSS ≥ 20).

RESULTS

A total of 303 men (mean age: 66.1 [SD: 8.1]) were included: 154 demonstrated moderate or severe symptoms with 28 severe and 149 with asymptomatic/mild symptoms. Increasing age [p = 0.02; odds ratio (OR): 1.05 (1.01-1.08)], PUA [p = 0.02; OR: 1.05 (1.01-1.09)], LH volume [p = 0.04; OR: 1.02 (1.00-1.05)], and DMR size measured as diameter [p < 0.001; OR: 5.0 (3.01-8.38)] or area [p < 0.001; OR: 1.92 (1.47-2.49)] were significantly independently associated with moderate/severe symptoms, with BMI [p = 0.02; OR: 0.93 (0.88-0.99)] inversely related. For every one cm increase in DMR diameter, patients had approximately five times the odds for moderate/severe symptoms. Increasing DMR size [diameter p < 0.001; OR: 2.74 (1.76-4.27) or area p < 0.001; OR: 1.37 (1.18-1.58)] was independently associated with severe symptoms. Optimal criterion cutoff of DMR diameter for moderate/severe symptoms was 1.2 cm [sensitivity: 77.3; specificity: 71.8; AUC: 0.80 (0.75-0.84)]. Inter-reader reliability was excellent for DMR diameter [ICC = 0.92 (0.90-0.94)].

CONCLUSION

Expansion of the DMR surrounding the bladder outlet is a novel anatomic factor independently associated with moderate and severe LUTS/BPH, taking into account prostate volumes, including quantified IPP volume, which were unrelated. Detrusor ring diameter, easily and reliably measured on routine prostate MRI, may relate to detrusor dysfunction from chronic stretching of this histologically distinct smooth muscle around the bladder neck.

CircRNA/miRNA/mRNA axis participates in the progression of partial bladder outlet obstruction

BACKGROUND

More and more evidence showed that circRNA/miRNA/mRNA axis played a vital role in the pathogenesis of some diseases. However, the role of circRNA/miRNA/mRNA axis in partial bladder outlet obstruction (pBOO) remains unknown. Our study aimed to explore the complex regulatory mechanism of circRNA/miRNA/mRNA axis in pBOO.

METHODS

The pBOO rat model was established, and the bladder tissues were collected for mRNA sequencing. The differentially expressed mRNAs were analyzed by high-throughput sequencing, and the GO and KEGG analysis of the differentially expressed mRNAs were performed. Competing endogenous RNAs (ceRNAs) analysis identified the potential regulation function of circRNA/miRNA/mRNA axis in pBOO. qRT-PCR detected the expression of circRNA/miRNA/mRNA. miRanda software was performed to predict the relationship between circRNA and miRNA, miRNA and mRNA.

RESULTS

Compared with the sham group, a total of 571 mRNAs were differentially expressed in the pBOO group, of which 286 were up-regulated and 285 were down-regulated. GO analysis showed that the mRNAs were mainly involved in cellular process, single-organism process, and cell, etc. KEGG analysis showed that the enriched signaling pathways were metabolic pathways, cell adhesion molecules (CAMs), and HTLV-I infection, etc. Based on the previous transcriptome data and differentially expressed circRNAs, we drew the ceRNA network regulation diagram. qRT-PCR results confirmed that chr3:113195876|113197193/rno-miR-30c-1-3p/Gata4, chr1:126188351|126195625/rno-miR-153-5p/Diaph3, and chr9:81258380|81275269/rno-miR-135b-5p/Pigr axis may have ceRNA function. miRanda confirmed there have the binding sites of circRNA/miRNA/mRNA axis.

CONCLUSIONS

CircRNA/miRNA/mRNA axis was involved in the progression of pBOO. Our research on the circRNA/miRNA/mRNA axis revealed new pathogenesis and treatment strategies for pBOO.

Change in postoperative storage symptoms and de novo urge-incontinence after Thulium: YAG laser enucleation of the prostate: results from a prospective, multicenter study

OBJECTIVES

To assess the change of storage symptoms and their impact on quality of life in men undergoing Thulium: YAG laser enucleation of the prostate (ThuLEP) for benign prostatic hyperplasia (BPH).

MATERIALS AND METHODS

BPH patients requiring surgery were prospectively evaluated (April 2019-October 2020).

INCLUSION CRITERIA

International Prostate Symptom Score (IPSS) ≥8, maximum urinary flow rate  ≤15 ml/s, and urinary retention.

EXCLUSION CRITERIA

previous urethral/prostatic surgery, pelvic irradiation, bladder/prostate cancer, neurogenic bladder, concomitant transurethral surgery, and active urinary tract infection. IPSS, International Continence Society-Overactive Bladder (ICIQ-OAB) and International Continence Society-Overactive Bladder Quality of Life (ICIQ-OABq) scores were gathered before surgery and 1,3,6 and 12 months after surgery.

RESULTS

117 men were included. Mean age was 68.0±7.7 years. Mean prostate volume was 86.6±34 cc. Mean IPSS subscore was 8.7±3.1 and 11.7±4.7 for storage and voiding symptoms, respectively. Mean ICIQ-OAB was 29.1±16.8. Mean ICIQ-OABq was 80.3±30.6. Voiding IPSS decreased 72.8% at 1-month, whereas the reduction of storage IPSS was 38.0%. ICIQ-OAB decreased 49.6% at 1-month. ICIQ-OABq showed a 30.0% reduction. One year after surgery, the reduction of voiding IPSS was 94.8%, ICIQ-OAB 85.5%, storage IPSS 76.7%, and ICIQ-OABq 60.5%. Urge-incontinence was present in 26.5% of men at 1-month, 15.4% at 3-month and 4.3% at 6-month. 4(3.4%) patients complained of urge-incontinence 12 months after surgery.

CONCLUSION

Both storage and voiding LUTS significantly decreased after ThuLEP but storage symptoms showed less reduction with a significant impact on patients' quality of life, particularly during the first 3 months.

Effect of Metabolic Syndrome on Anatomy and Function of the Lower Urinary Tract Assessed on MRI

OBJECTIVE

To investigate the relationship between metabolic syndrome (MetS) and lower urinary tract symptoms (LUTS) with functional and anatomic changes of the lower urinary tract with MRI.

MATERIALS AND METHODS

The bladder and prostate of 95 subjects (56M, 39F) were segmented on T2-weighted pelvic MRI using Materialize Mimics 3D software. Bladder wall volume (BWV), post-void residual (PVR) and prostate volume (PV) were quantified from the 3D renderings. LUTS were quantified using validated questionnaires administered at the time of MRI. Wilcoxin rank sum, win ratio and chi-square tests were used to correlate symptom scores, BWV, PVR and PV in patients 1) without vs with MetS, 2) with mild (IPSS or UDI-6: 0-7) vs moderate-severe (IPSS: 8-35 or UDI-6: ≥8) and 3) normal vs enlarged prostates (>40cm³). Multivariate linear regression was used to determine predictors for BWV, PVR and PV.

RESULTS

Men with MetS had increased BWV (66.8 vs 51.1cm³, P = .003), higher PVR (69.1 vs 50.5cc, P= .05) and increased PV (67.2 vs 40.1cm³, P= .01). Women without and with MetS had similar BWV, PVR and LUTS (P= .3-.78). There was no difference in prevalence of MetS, BWV, PVR or PV in men or women with mild vs moderate-severe LUTS (P = .26-.97). Men with enlarged prostates were more likely to have MetS (P = .003). There was no difference in BWV, PVR and LUTS for men with normal vs enlarged prostates (P= .44-.94). In men, BWV was highly correlated with MetS (P = .005) on regression analysis.

CONCLUSION

MetS leads to detrusor hypertrophy and may contribute to impaired bladder function, likely related to the effect on the prostate.

Efficacy of Holmium laser enucleation of the prostate in men with impaired bladder contractility: A review

Introduction:

Since Holmium laser enucleation of the prostate (HoLEP) was introduced in the 1990s as an endoscopic deobstructing modality for benign prostatic hyperplasia (BPH), several reports have concluded that HoLEP has compared favourably to transurethral resection of prostate (TURP) in relieving Bladder Outlet Obstruction (BOO). However, there has been no consensus regarding the efficacy of surgical management of men with Detrusor Underactivity (DU) and BOO.

Methods:

We performed a literature search of PubMed, Google Scholar, Scopus, and Web of Science databases. All studies that provided data on the effectiveness of HoLEP in men with BOO and DU were assessed. Data collected included the number of patients, median follow-up, International Prostate Symptom Score (IPSS), Qmax, post-void residual (PVR) and catheter dependency pre- and post-intervention.

Results:

Nine studies were identified in the literature with a follow-up range between 6 and 60 months. Only one prospective study was identified where investigators performed urodynamic studies (UDSs) before and after the intervention. In addition to a significant improvement of voiding parameters, they reported partial recovery of detrusor muscle contractility in approximately 80% of patients. Furthermore, all other studies reported an improvement in all outcome parameters and proved the efficacy of HoLEP in patients with DU and BOO.

Conclusion:

The current literature underpins the efficacy of HoLEP in patients with impaired bladder contractility. However, current research is limited and the majority of the published data are retrospective in nature. Therefore, more well-conducted prospective randomised studies are needed to reinforce high-level evidence for this hypothesis.

Level of evidence:

Not applicable.

Partial inhibition of activin receptor-like kinase 4 alleviates bladder fibrosis caused by bladder outlet obstruction

The bladder undergoes profound structural alterations after bladder outlet obstruction (BOO), characterized by hypertrophy of the bladder wall and accumulation of extracellular matrix (ECM). Transforming growth factor-β (TGF-β) has been found to promote fibrosis of the bladder induced by partial bladder outlet obstruction (pBOO). Activin receptor-like kinase 4 (ALK4) is a downstream receptor of the TGF-β superfamily. However, the role of the ALK4-Smad2/3 pathway in the pathogenesis of bladder fibrosis caused by pBOO remains unknown. This study focused on learning the role of ALK4 in the process of bladder fibrosis caused by pBOO. The pBOO mice models showed that ALK4 expression was found to upregulate in the wild-type bladder 6 weeks after pBOO compared to control group. Then, mice with heterozygous knockout of the ALK4 gene (ALK4+/-) were generated. Histological analysis and Western blot (WB) results showed significant suppression of collagen expression in the bladders of ALK4+/- mice after pBOO compared with WT mice. WB also showed that ALK4+/- mice demonstrated significant suppression of phosphorylated Smad2/3 (p-Smad2/3) expression in the bladder 6 weeks after pBOO but not of phosphorylated extracellular signal-regulated kinase, c-Jun N-terminal kinase or protein 38 (p-ERK, p-JNK, p-P38) expression. This effect might have occurred through partial inactivation of the Smad2/3 signaling pathway. In vitro, ALK4 overexpression promoted collagen production in cultured BSMCs and activated the Smad2/3 signaling pathway. Taken together, our results demonstrated that ALK4 insufficiency alleviated bladder fibrosis in a mouse model of pBOO partly by suppressing Smad2/3 activity.

Inhibition of DNA methylation during chronic obstructive bladder disease (COBD) improves function, pathology and expression

Partial bladder outlet obstruction due to prostate hyperplasia or posterior urethral valves, is a widespread cause of urinary dysfunction, patient discomfort and also responsible for immense health care costs. Even after removal or relief of obstruction, the functional and pathologic aspects of obstruction remain as a chronic obstructive bladder disease (COBD). Epigenetic changes, such as DNA methylation, contribute to the persistent character of many chronic diseases, and may be altered in COBD. We tested whether candidate genes and pathways and the pathophysiology of COBD were affected by a hypomethylating agent, decitabine (DAC). COBD was created in female Sprague-Dawley rats by surgical ligation of the urethra for 6 weeks, followed by removal of the suture. Sham ligations were performed by passing the suture behind the urethra. After removal of the obstruction or sham removal, animals were randomized to DAC treatment (1 mg/kg/3-times/week intraperitoneally) or vehicle (normal saline). Bladder function was non-invasively tested using metabolic cages, both one day prior to de-obstruction at 6 weeks and prior to sacrifice at 10 weeks. Residual volume and bladder mass were measured for each bladder. Bladders were examined by immunostaining as well as qPCR. The effects of DNA methyltransferase (DNMT)-3A knockout or overexpression on smooth muscle cell (SMC) function and phenotype were also examined in bladder SMC and ex vivo culture. Residual volumes of the DAC treated group were not significantly different from the NS group. Compared to COBD NS, COBD DAC treatment helped preserve micturition volume with a significant recovery of the voiding efficiency (ratio of the maximum voided volume/maximum bladder capacity) by one third (Fig. 1, p > 0.05). Brain-derived neurotrophic factor (BDNF) variants 1 and 5 were upregulated by COBD and significantly reduced by DAC treatment. Deposition of collagen in the COBD bladder was reduced by DAC, but gross hypertrophy remained. In bladder SMC, DNMT3A overexpression led to a loss of contractile function and phenotype. In bladders, persistently altered by COBD, inhibition of DNA-methylation enhances functional recovery, unlike treatment during partial obstruction, which exacerbates obstructive pathology. The underlying mechanisms may relate to the gene expression changes in BDNF and their effects on signaling in the bladder.

Is Early Surgical Treatment for Benign Prostatic Hyperplasia Preferable to Prolonged Medical Therapy: Pros and Cons

Background and objectives: Treatment of lower urinary tract symptoms (LUTS) related to benign prostatic hyperplasia (BPH) has shifted over the last decades, with medical therapy becoming the primary treatment modality while surgery is being reserved mostly to patients who are not responding to medical treatment or presenting with complications from BPH. Here, we aim to explore the evidence supporting or not early surgical treatment of BPH as opposed to prolonged medical therapy course. Materials and Methods: The debate was presented with a “pro and con” structure. The “pro” side supported the early surgical management of BPH. The “con” side successively refuted the “pro” side arguments. Results: The “pro” side highlighted the superior efficacy and cost-effectiveness of surgery over medical treatment for BPH, as well as the possibility of worse postoperative outcomes for delayed surgical treatment. The “con” side considered that medical therapy is efficient in well selected patients and can avoid the serious risks inherent to surgical treatment of BPH including important sexual side effects. Conclusions: Randomized clinical trials comparing the outcomes for prolonged medical therapy versus early surgical treatment could determine which approach is more beneficial in the long-term in context of the aging population. Until then, both approaches have their advantages and patients should be involve in the treatment decision.

Potential urine biomarkers in bladder outlet obstruction-related detrusor underactivity

Detrusor underactivity (DU), an important but under-researched issue, is thought to be complex and multifactorial in etiology, pathophysiology, and diagnosis. Bladder outlet obstruction (BOO) is one of the important known etiologies of DU, with significant morphologic and physiologic changes of the urothelium, suburothelium, and detrusor muscle in the urinary bladder. Chronic urinary bladder ischemia and repeated cycles of ischemia and reperfusion injury cause excessive oxidative stress, and it is thought to be responsible for the development of DU. DU might be the late phase or decompensated status of BOO, with the possible mechanisms of afferent nervous dysfunction, increased inflammation, denervation of the detrusor muscle, and myogenic failure. Prostaglandin E2 (PGE2) involves in the physiological detrusor contraction, and might provide the prognostic value for the recoverability of DU. Neurotrophins, including nerve growth factor and brain-derived neurotrophic factor, involve in the neuroplastic changes in many inflammatory bladder diseases, including BOO and DU. Oxidative stress biomarkers, including 8-hydroxy-2-deoxyguanosine, F2-isoprostane, and the involved pro-inflammatory cytokines, have been applied in BOO due to their involvements in chronic bladder ischemia. PGE2, neurotrophins, inflammatory cytokines, and oxidative stress biomarkers are the potential urine biomarkers in BOO-related DU.

Comprehensive non-invasive analysis of lower urinary tract anatomy using MRI

PURPOSE

Anatomic changes that coincide with aging including benign prostatic hyperplasia (BPH) and lower urinary tract symptoms (LUTS) negatively impact quality of life. Use of MRI with its exquisite soft tissue contrast, full field-of-view capabilities, and lack of radiation is uniquely suited for quantifying specific lower urinary tract features and providing comprehensive measurements such as total bladder wall volume (BWV), bladder wall thickness (BWT), and prostate volume (PV). We present a technique for generating 3D anatomical renderings from MRI to perform quantitative analysis of lower urinary tract anatomy.

METHODS

T2-weighted fast-spin echo MRI of the pelvis in 117 subjects (59F;58 M) aged 30-69 (49.5 ± 11.3) without known lower urinary tract symptoms was retrospectively segmented using Materialise software. Virtual 3D models were used to measure BWV, BWT, and PV.

RESULTS

BWV increased significantly between the 30-39 and 60-69 year age group in women (p = 0.01), but not men (p = 0.32). BWV was higher in men than women aged 30-39 and 40-49 (p = 0.02, 0.05, respectively) ,but not 50-59 or 60-69 (p = 0.18, 0.16, respectively). BWT was thicker in men than women across all age groups. Regional differences in BWT were observed both between men and women and between opposing bladder wall halves (anterior/posterior, dome/base, left/right) within each sex in the 50-59 and 60-69 year groups. PV increased from the 30-39 to 60-69 year groups (p = 0.05). BWT was higher in subjects with enlarged prostates (> 40cm³) (p = 0.05).

CONCLUSION

Virtual 3D MRI models of the lower urinary tract reliably quantify sex-specific and age-associated changes of the bladder wall and prostate.

Urodynamics in Posterior Urethral Valve: Pursuit of prognostication or optimisation

INTRODUCTION

Detrusor dysfunction is known to persist in several patients of Posterior Urethral Valve (PUV) after successful fulguration leading to progressive deterioration of renal function. Persistent bladder outlet obstruction (BOO) in the form of bladder neck hypertrophy, residual valves or strictures may contribute to progressive detrusor dysfunction. These are assessed radiologically or cystoscopically and are managed variedly by anticholinergics, alpha-adrenergic blockers or even bladder neck incision. Unfortunately, currently we do not have any objective measures to evaluate the degree of BOO in children or follow treatment outcome of any such measures.

OBJECTIVE

To assess the feasibility of pressure flow studies in children and proposition of an age independent index to quantify outflow parameters.

STUDY DESIGN

We retrospectively studied the urodynamic data of the follow up cases of PUV who had been referred to us for urodynamic evaluation. Free flow uroflowmetries and filling and voiding cystometrogram were performed as per recommended protocol. Parameters like Adjusted Bladder Capacity (ABC = Voided volume + post void residue; expressed as percentage of expected bladder capacity {EBC}), overactivity, compliance, Qmax and P _{det at Qmax} were taken into consideration. Indices like Bladder Outlet Obstruction Index (BOOI) and Bladder Contractility Index (BCI) were calculated. Multivariate analysis was run to assess correlation of ABC with other parameters. Receiver Operating Characteristics (ROC) curve analysis was performed to assess predictive values of BOOI for ABC.

RESULTS

We did not find the ABC to change with age as has been classically described. Qmax and BCI were found to correlate with age. Values obtained for P _{det at Qmax} and BOOI were not dependent on age and were in similar range as observed in adults. On multivariate analysis, small bladder was found to positively correlate with presence of overactivity, high BOOI and low BCI. ROC curve analysis showed a BOOI >29 could predict ABC to be <100% EBC with moderate sensitivity and specificity.

DISCUSSION

Pressure flow studies are the only objective means of quantifying outlet resistance, hitherto they have been considered to be unrepresentative in children. Documentation and correction of high outflow pressures may arrest the cycle of detrusor hypertrophy and dysfunction.

CONCLUSION

Quality pressure flow studies are feasible in children. Values of P _{det at Qmax} and BOOI in children are age independent and similar to those observed in adults. BOOI can be potentially used in children to assess degree of BOO.

A pilot study of bladder voiding with real-time MRI and computational fluid dynamics

Lower urinary track symptoms (LUTS) affect many older adults. Multi-channel urodynamic studies provide information about bladder pressure and urinary flow but offer little insight into changes in bladder anatomy and detrusor muscle function. Here we present a novel method for real time MRI during bladder voiding. This was performed in a small cohort of healthy men and men with benign prostatic hyperplasia and lower urinary tract symptoms (BPH/LUTS) to demonstrate proof of principle; The MRI urodynamic protocol was successfully implemented, and bladder wall displacement and urine flow dynamics were calculated. Displacement analysis on healthy controls showed the greatest bladder wall displacement in the dome of the bladder while men with BPH/LUTS exhibited decreased and asymmetric bladder wall motion. Computational fluid dynamics of voiding showed men with BPH/LUTS had larger recirculation regions in the bladder. This study demonstrates the feasibility of performing MRI voiding studies and their potential to provide new insight into lower urinary tract function in health and disease.

Rac1 silencing, NSC23766 and EHT1864 reduce growth and actin organization of bladder smooth muscle cells

AIMS

RacGTPase-mediated proliferation and smooth muscle contraction in the lower urinary tract has been recently suggested and may offer putative targets for treamtment of lower urinary tract symptoms. However, RacGTPase function for proliferation of detrusor smooth muscle cells is unknown and the specificity of Rac inhibitors has been questioned. Here, we examined effects of Rac1 knockdown and of the Rac inhibitors NSC23766 and EHT1864 in human bladder smooth muscle cells (hBSMCs).

MAIN METHODS

Rac1 expression was silenced by shRNA expression. Effects of silencing and Rac inhibitors were assessed by CCK-8 assay, EdU staining, RT-PCR, colony formation assay, flow cytometry, and phalloidin staining.

KEY FINDINGS

Silencing of Rac1 expression reduced the viability (up to 83% compared to scramble shRNA) and proliferation (virtually completely in proliferation assay), increased apoptosis (124%) and the number of dead cells (51%), and caused breakdown of actin organization (56% reduction of polymerized actin compared to scramble shRNA). Effects on proliferation, viability, and actin organization were mimicked by NSC23766 and EHT1864, while both compounds showed divergent effects on cell death (32-fold increase of dead cells by EHT1864, but not NSC23766). Effects of NSC23766 and EHT1864 on viability of hBSMCs were not altered by Rac1 knockdown.

SIGNIFICANCE

Rac1 promotes proliferation, viability, and cytoskeletal organization, and suppresses apoptosis in bladder smooth muscle cells, which may be relevant in overactive bladder or diabetes-related bladder dysfunction. NSC23766 and EHT1864 mimick these effects, but may act Rac1-independently, by shared and divergent effects.

Clinical Efficacy of Transurethral Resection of the Prostate Combined with Oral Anticholinergics or Botulinum Toxin - A Injection to Treat Benign Prostatic Hyperplasia with Overactive Bladder: A Case-Control Study

Introduction

Recent investigations showed that anticholinergic drugs could use for the management of storage symptoms after transurethral resection of the prostate (TURP). The use of intravesical botulinum toxin-A (BTX-A) for the management of overactive bladder is rapidly increasing. In this research, we assess the efficacy of BTX-A vs solifenacin in men suffering from bladder outlet obstruction–over active bladder (BOO-OAB) managed with TURP.

Methods

In this case–control study, 50 men with BOO-OAB randomized into two groups. The control group (A) underwent TURP and subsequently managed by solifenacin 5 mg daily, and the case group (B) underwent TURP and BTX-A injection in the bladder wall in the same session. Treatment success was the primary outcome and defined as post-injection improvement in the storage score of the International Prostate Symptom Score (IPSS) from baseline.

Results

The IPSS, post-void residual volume, frequency, incomplete emptying, nocturia and urgency subscores considerably ameliorated after 12 weeks and 36 weeks for both groups, but it was more significant in the case arm. The quality of life (QoL) scores significantly improved after the treatments in both groups. Intervention group showed significant reductions regarding urgency incontinence compared with the solifenacin group at 12th and 36th weeks.

Conclusion

BTX-A is an effective and well-tolerated treatment in patients with benign prostatic hyperplasia (BPH) who are candidates of TURP and simultaneously suffer from OAB symptoms.

Super early detailed assessment of lower urinary tract symptoms after holmium laser enucleation of the prostate (HoLEP): a prospective study

PURPOSE

To prospectively investigate early and consecutive changes of lower urinary tract symptoms (LUTS), specifically storage symptoms after holmium laser enucleation of the prostate (HoLEP).

METHODS

Patients referred for HoLEP completed the International Prostatic Symptom Score (IPSS) the day before, at discharge, and 1, 2, 3, 4, 6, 8, 12, 16, 20, 24, and 52 weeks after HoLEP. Total IPSS was stratified into mild (score 0-7), moderate (8-19), and severe (20-35) LUTS. Storage symptoms were sub-stratified into storage "negative" and "positive". IPSS changes served as the main postoperative outcome. Mixed linear models identified risk factors affecting postoperative recovery of LUTS.

RESULTS

Between December 2010 and 2012, 144 consecutive HoLEP patients were prospectively included in the study. Preoperatively 57.6% of the cohort reported severe storage symptoms (mean total IPSS: 22.6 ± 5.0). Total IPSS decreased significantly immediately after surgery (p < 0.001). Patients with severe LUTS, storage-positive sub-score, and high maximum urinary flow rate were affected by a rebound of mainly storage symptoms 6-8 weeks after HoLEP and prolonged recovery from LUTS. Of these, about 7.4% presented persisting urge complaints. Finally, 12 weeks following HoLEP, the vast majority of patients were symptom-free. Limitations of this study include missing urodynamic workup and a comparative patient cohort.

CONCLUSION

Immediately after HoLEP, patients experience a significant decrease of LUTS. Continuous symptom recovery seems to be hampered in patients with severe and storage-positive baseline symptoms. (De-novo) storage symptoms slightly affect postoperative recovery. Quality of life is restored to a stable and significantly improved status 3 months after surgery.

Activation of Prejunctional P2x2/3 Heterotrimers by ATP Enhances the Cholinergic Tone in Obstructed Human Urinary Bladders

The objective of this study was to investigate the role of ATP in cholinergic neurotransmission in the urinary bladder of control men and of patients obstructed as a result of benign prostatic hyperplasia (BPH). Human detrusor samples were collected from 41 patients who submitted to transvesical prostatectomy resulting from BPH and 26 male organ donors. The release of [³H]acetylcholine ([³H]ACh) was evoked by electrical field stimulation (10 Hz, 200 pulses) in urothelium-denuded detrusor strips. Myographic recordings were performed to test detrusor strip sensitivity to ACh and ATP. Nerve-evoked [³H]ACh release was 1.5-fold higher in detrusor strips from BPH patients compared with controls. This difference was abolished after desensitization of ionotropic P2X1-3 receptors with an ATP analog, α,β-methylene ATP (30 μM, applied for 15 minutes). TNP-ATP (10 nM, a preferential P2X2/3 antagonist) and A317491 (100 nM, a selective P2X3 antagonist) were about equipotent in decreasing nerve-evoked [³H]ACh release in control detrusor strips, but the selective P2X1 receptor antagonist NF023 (3 μM) was devoid of effect. The inhibitory effect of TNP-ATP (10 nM) increased from 27% ± 9% to 43% ± 6% in detrusor strips of BPH patients, but the effect of A317491 (100 nM) [³H]ACh release unaltered (20% ± 2% vs. 24% ± 4%). The amplitude of ACh (0.1-100 μM)-induced myographic recordings decreased, whereas sensitivity to ATP (0.01-3 mM) increased in detrusor strips from BPH patients. Besides the well characterized P2X1 receptor-mediated contractile activity of ATP in pathologic human bladders, we show here for the first time that cholinergic hyperactivity in the detrusor of BPH patients is facilitated by activation of ATP-sensitive P2X2/3 heterotrimers. SIGNIFICANCE STATEMENT: Bladder outlet obstruction often leads to detrusor overactivity and reduced bladder compliance in parallel to atropine-resistant increased purinergic tone. Our data show that P2X1 purinoceptors are overexpressed in the detrusor of patients with benign prostatic hyperplasia. Besides the P2X1 receptor-mediated detrusor contractions, ATP favors nerve-evoked acetylcholine release via the activation of prejunctional P2X2/3 excitatory receptors in these patients Thus, our hypothesis is that manipulation of the purinergic tone may be therapeutically useful to counteract cholinergic overstimulation in obstructed patients.

Is there a correlation between structural changes of the bladder wall and its dysfunction? A Prospective Study

The aim of the study was to evaluate the microscopic structure of the bladder wall in children with a neurogenic bladder to find a correlation between changes in the microscopic structure of the bladder wall and functional disorders. The study group consisted of 42 children who underwent bladder augmentation. Full-thickness fragments of the bladder wall were collected during operation, photographed for evaluation with a morphometric analysis. The proportion of muscle and connective tissue was determined. Results were correlated with the results of urodynamic tests. The analysis showed a progressive increase in connective/muscle tissue ratio with a decrease in the number of nerve trunks with a correlation between the connective/muscle tissue ratio and the deterioration of lower urinary tract in urodynamic investigations. Dysfunctions of the bladder are associated with histological abnormalities of the bladder wall, particularly increases in the amount of connective tissue and reduction of the number of nerve trunks. The increase in the percentage of the connective tissue correlates positively with deterioration of bladder function, reduced compliance of the bladder wall, and changes in the structure of the bladder wall and deterioration of the upper urinary tract.

The Utilization of Benign Prostatic Hyperplasia and Bladder-Related Medications After a Transurethral Prostatectomy

OBJECTIVE

To determine how often prostate- and bladder-specific medications for lower urinary tract symptoms are used following a transurethral prostatectomy (TURP).

METHODS

This study utilized several linked, routinely collected datasets from the province of Ontario, Canada to identify men older than 66 years who underwent their first TURP between April 2003 and March 2016. The primary outcome was the probability of using at least 30 days of either prostate-specific alpha blockers (AB), 5-alpha reductase inhibitors (5ARI), or anticholinergics/beta-3 agonists (AC/B3) after their TURP.

RESULTS

We identified 58,038 men (median age 75), with a median follow-up of 4.9 years. In the 6 months prior to their TURP, AB, 5ARIs or AC/B3 were used by 62%, 32%, and 6%, respectively. Following a 90-day washout period after TURP, these medications were used by 27%, 20%, and 15% of men, respectively. The cumulative probability of using these medications within the first 10 years after TURP was 38%, 28%, and 20%, respectively. Family physicians prescribed the majority of AB, while urologists prescribed the majority of the AC/B3. Among men on AC/B3 prior to TURP, 46% used them after TURP; in multivariate cox regression analysis age ≥75, diabetes, preoperative use of AC/B3, and no preoperative urinary retention predicted postoperative utilization of AC/B3 medications.

CONCLUSION

There is considerable use of AB and 5ARIs despite a lack of evidence for using these medications after a TURP. Given the well-characterized placebo response in BPH patients, this practice should be properly evaluated for clinical efficacy.

Responses of bladder smooth muscle to the stretch go through extracellular signal-regulated kinase (ERK)/p90 ribosomal S6 protein kinase (p90RSK)/Nuclear factor-κB (NF-κB) Pathway

AIMS

The present study was designed to study changes and its potential mechanisms in human bladder smooth muscle subjected to stretch.

METHODS

Bioinformatics analyses including differential expression analysis, overrepresentation enrichment analysis, principal component analysis, and weighted gene coexpression network analysis were used to analyze a microarray dataset (GSE47080) of partial bladder outlet obstruction (pBOO) in rat to find the potential changes of gene expressions. Bladder from pBOO model and human bladder smooth muscle cells (HBSMCs) subjected to sustained prolonged stretch were collected for Western blot analysis, real-time polymerase chain reaction, and fluorescence analysis to verify the changes of gene expressions and preliminarily study the potential role of signaling pathway regulation in treatment of pBOO.

RESULTS

The bioinformatics analysis showed that chronic obstruction activated mitogen-activated protein kinase pathway and changed cytoskeleton structure in bladder smooth muscle. In in vivo experiments in mice, pBOO was verified by cystometry. Partial BOO activated the extracellular signal-regulated kinase (ERK)/p90 ribosomal S6 protein kinase (p90RSK)/nuclear factor-κB (NF-κB) signaling pathway in DM. The messenger RNA (mRNA) expressions of contractile phenotypic proteins increased after pBOO. In in vitro experiments of HBSMCs, mechanical stretch activated ERK/p90RSK/NF-κB in HBSMCs in a time-dependent manner. The mRNA expressions of α-smooth muscle actin and SM22 also increased and filamentous actin (F-actin) polymerization was enhanced as well. Inhibition of ERK/p90RSK/NF-κB pathway reversed mechanical stretch-induced changes of contractile phenotypic expression and F-action polymerization.

CONCLUSIONS

Continuous stretch increases expressions of contractile phenotypic proteins and promotes the polymerization of F-actin. This process partially goes through ERK/p90RSK/NF-κB pathway.

Association between urodynamic parameters and urine neutrophil gelatinase-associated lipocalin concentrations in children with neuropathic bladders

BACKGROUND

Neutrophil gelatinase-associated lipocalin (NGAL) is a marker of acute kidney injury, and has been shown to be a sensitive marker of renal damage in urinary tract obstruction. Children with neurogenic bladders are at risk of renal damage as a result of increased pressure within the urinary system. A marker of upper tract deterioration in this population would be useful to guide management.

OBJECTIVE

The aim of the study is to compare urinary NGAL (uNGAL) concentrations between children who have elevated and normal detrusor pressure and between those with low and normal compliance, on urodynamics.

STUDY DESIGN

This is a cross-sectional study of children with neurogenic bladder who underwent routine urodynamics from August 2015 to March 2016. Patients with positive urine cultures from the time of urodynamics were excluded from analysis. Urine was obtained from the time of urodynamics for uNGAL measurement. Urodynamics were reviewed. High pressure is defined as a detrusor pressure of 40 cm of water or greater at the volume where catheterization is normally performed. Compliance was calculated at the volume where catheterization is performed.

RESULTS

A total of 89 patients were included (low pressure, n = 73; high pressure, n = 16 and low compliance, n = 41; normal compliance, n = 40). Median uNGAL concentrations were not different between patients with low and high pressure, but there was a higher median uNGAL concentration in patients with normal compliance compared with those with low compliance. There was no correlation between maximum detrusor pressure and uNGAL concentration, but there was a moderate relationship between compliance and uNGAL concentration (r_s = 0.43, p < 0.01 for non-normalized uNGAL and r_s = 0.30, p < 0.01 for normalized uNGAL).

DISCUSSION AND CONCLUSION

There is an increase in uNGAL concentrations in patients with normal compliance compared with those with low compliance, but no difference between patients with low or high pressure.

Functional changes in low- and high-threshold afferents in obstruction-induced bladder overactivity

Neural mechanisms of lower urinary tract symptoms in obstruction-induced bladder overactivity remain unclear. We made the first single unit recordings from different types of spinal afferents to determine the effects of bladder outlet obstruction in guinea pigs. A model of gradual bladder outlet obstruction in male guinea pigs was used to produce overactive bladder. Conscious voiding was assessed in metabolic cages, and micturition was recorded in anesthetized guinea pigs in vivo. Single unit extracellular recordings were made ex vivo from spinal afferent nerves in flat sheet preparations of the bladder. Guinea pigs with partially obstructed bladders showed a significant increase in conscious voiding frequency compared with sham-operated guinea pigs. Also, nonvoiding contractions increased significantly in both frequency and amplitude. Although spontaneous firing of low-threshold bladder afferents was increased, their stretch-induced firing was reduced. The proportion of capsaicin-sensitive low-threshold afferents increased in obstructed bladders. Interestingly, spontaneous and stretch-induced firing were both significantly increased in high-threshold afferents after obstruction. In summary, sensory signaling increased in the obstructed bladder during the filling phase. This is largely mediated by low-threshold stretch-sensitive afferents that are activated by increased local nonvoiding contractions. Increased spontaneous firing by high-threshold afferents also contributes. Our findings revealed a complex effect of bladder outlet obstruction on different types of bladder afferents that needs consideration for potential therapeutic targeting of lower urinary tract symptoms in obstruction-induced bladder overactivity.

Effects of Qianlie Tongqiao Capsule on Bladder Weight and Growth Factors in Bladder Tissue of Rats with Testosterone-Induced Benign Prostatic Hyperplasia

Qianlie Tongqiao Capsule (QTC) is clinically confirmed to be efficacious and safe in treating lower urinary tract syndromes and bladder dysfunction that are induced by benign prostatic hyperplasia (BPH). However, the functional mechanisms of QTC remain unclear. We aim to investigate the effects of QTC on both bladder weight and several growth factors in the bladder tissue of rats with testosterone-induced BPH. BPH in the rats was established through bilateral orchiectomy and subcutaneous administration of testosterone propionate (5 mg/kg) dissolved in corn oil. At the end of the study, all bladder tissues were collected and weighed, and a histological examination was conducted using H&E staining. Immunohistochemistry and quantitative reverse transcription-polymerase chain reaction (qRT-PCR) were applied to detect the expression of nerve growth factor (NGF), basic fibroblast growth factor (bFGF), and transformation growth factor-β1 (TGF-β1) in the bladder tissue. The expression of Bcl-2 and Bax in the bladder tissue was tested by Western Blot and qRT-PCR. We found that QTC, especially when administered in high-dosages, had a significant inhibitory effect on bladder weight gain and overexpression of NGF, bFGF, and TGF-β1 in rats with BPH. In addition, QTC downregulated and upregulated protein and mRNA expression of Bcl-2 and Bax in the bladder after prostatic obstruction, respectively. Furthermore, QTC balanced the Bcl-2/Bax ratio. Overall, these results reveal possible functional mechanisms of QTC in treating BPH-caused bladder dysfunction, and further studies are needed.

Changes in brain white matter structure are associated with urine proteins in urologic chronic pelvic pain syndrome (UCPPS): A MAPP Network study

The Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP) Research Network has yielded neuroimaging and urinary biomarker findings that highlight unique alterations in brain structure and in urinary proteins related to tissue remodeling and vascular structure in patients with Urological Chronic Pelvic Pain Syndrome (UCPPS). We hypothesized that localized changes in diffusion tensor imaging (DTI) measurements might be associated with corresponding changes in urinary protein levels in UCPPS. To test this hypothesis, we created statistical parameter maps depicting the linear correlation between DTI measurements (fractional anisotropy (FA) and apparent diffusion coefficient (ADC)) and urinary protein quantification (MMP2, MMP9, NGAL, MMP9/NGAL complex, and VEGF) in 30 UCPPS patients from the MAPP Research Network, after accounting for clinical covariates. Results identified a brainstem region that showed a strong correlation between both ADC (R² = 0.49, P<0.0001) and FA (R² = 0.39, P = 0.0002) with urinary MMP9 levels as well as a correlation between both ADC (R² = 0.42, P = 0.0001) and FA (R² = 0.29, P = 0.0020) and urinary MMP9/NGAL complex. Results also identified significant correlations between FA and urinary MMP9 in white matter adjacent to sensorimotor regions (R² = 0.30, P = 0.002; R² = 0.36, P = 0.0005, respectively), as well as a correlation in similar sensorimotor regions when examining ADC and urinary MMP2 levels (R² = 0.42, P<0.0001) as well as FA and urinary MMP9/NGAL complex (R² = 0.33, P = 0.0008). A large, diffuse cluster of white matter was identified as having a strong correlation between both ADC (R² = 0.35, P = 0.0006) and FA (R² = 0.43, P<0.0001) with urinary NGAL levels. In contrast, no significant association between DTI measurements and VEGF was observed. Results suggest that elevated MMP9 or MMP9/NGAL in UCPPS may be related to degenerative neuronal changes in brainstem nuclei through excitotoxicity, while also facilitating synaptic plasticity in sensorimotor regions.

Comprehensive urinary metabolomic characterization of a genetically induced mouse model of prostatic inflammation

Dysfunction of the lower urinary tract commonly afflicts the middle-aged and aging male population. The etiology of lower urinary tract symptoms (LUTS) is multifactorial. Benign prostate hyperplasia, fibrosis, smooth muscle contractility, and inflammation likely contribute. Here we aim to characterize the urinary metabolomic profile associated with prostatic inflammation, which could inform future personalized diagnosis or treatment, as well as mechanistic research. Quantitative urinary metabolomics was conducted to examine molecular changes following induction of inflammation via conditional Interleukin-1β expression in prostate epithelia using a novel transgenic mouse strain. To advance method development for urinary metabolomics, we also compared different urine normalization methods and found that normalizing urine samples based on osmolality prior to LC-MS most completely separated urinary metabolite profiles of mice with and without prostate inflammation via principal component analysis. Global metabolomics was combined with advanced machine learning feature selection and classification for data analysis. Key dysregulated metabolites and pathways were identified and were relevant to prostatic inflammation, some of which overlapped with our previous study of human LUTS patients. A binary classification model was established via the support vector machine algorithm to accurately differentiate control and inflammation groups, with an area-under-the-curve value of the receiver operating characteristic of 0.81, sensitivity of 0.974 and specificity of 0.995, respectively. This study generated molecular profiles of non-bacterial prostatic inflammation, which could assist future efforts to stratify LUTS patients and develop new therapies.

Augmentation Cystoplasty of Diseased Porcine Bladders with Bi-Layer Silk Fibroin Grafts

IMPACT STATEMENT

The search for an ideal "off-the-shelf" biomaterial for augmentation cystoplasty remains elusive and current scaffold configurations are hampered by mechanical and biocompatibility restrictions. In addition, preclinical evaluations of potential scaffold designs for bladder repair are limited by the lack of tractable large animal models of obstructive bladder disease that can mimic clinical pathology. The results of this study describe a novel, minimally invasive, porcine model of partial bladder outlet obstruction that simulates clinically relevant phenotypes. Utilizing this model, we demonstrate that acellular, bi-layer silk fibroin grafts can support the formation of vascularized, innervated bladder tissues with functional properties.

Urinary bladder organ hypertrophy is partially regulated by Akt1-mediated protein synthesis pathway

AIMS

The present study aims to investigate the role of Akt in the regulation of urinary bladder organ hypertrophy caused by partial bladder outlet obstruction (pBOO).

MAIN METHODS

Male rats were surgically induced for pBOO. Real-time PCR and western blot were used to examine the levels of mRNA and protein. A phosphoinositide 3-kinase (PI3K) inhibitor LY294002 was used to inhibit the activity of endogenous Akt.

KEY FINDINGS

The urinary bladder developed hypertrophy at 2 weeks of pBOO. The protein but not mRNA levels of type I collagen and α-smooth muscle actin (αSMA) were increased in pBOO bladder when compared to sham control. The phosphorylation (activation) levels of Akt1 (p-Ser⁴⁷³), mammalian target of rapamycin (mTOR), p70S6 kinase (p70S6K), and 4E-BP1 were also increased in pBOO bladder. LY294002 treatment reduced the phosphorylation levels of Akt1 and 4E-BP1, and the protein levels of type I collagen and αSMA in pBOO bladder. The mRNA and protein levels of proliferating cell nuclear antigen (PCNA) were increased in pBOO bladder, and PCNA up-regulation occurred in urothelial not muscular layer. LY294002 treatment had no effect on the mRNA and protein levels of PCNA in pBOO bladder. LY294002 treatment partially reduced the bladder weight caused by pBOO.

SIGNIFICANCE

pBOO-induced urinary bladder hypertrophy is attributable to fibrosis, smooth muscle cellular hypertrophy, and urothelium cell hyper-proliferation. Akt1-mediated protein synthesis in pBOO bladder contributes to type I collagen and αSMA but not PCNA up-regulation. Target of Akt1 is necessary but not sufficient in treatment of urinary bladder hypertrophy following pBOO.

Progressive bladder remodeling due to bladder outlet obstruction: a systematic review of morphological and molecular evidences in humans

BACKGROUND

Bladder outlet obstruction is a common urological condition. We aimed to summarize available evidences about bladder outlet obstruction-induced molecular and morphological alterations occurring in human bladder.

METHODS

We performed a literature search up to December 2017 including clinical and preclinical basic research studies on humans. The following search terms were combined: angiogenesis, apoptosis, bladder outlet obstruction, collagen, electron microscopy, extracellular matrix, fibrosis, hypoxia, histology, inflammation, innervation, ischemia, pressure, proliferation, remodeling, suburothelium, smooth muscle cells, stretch, urothelium.

RESULTS

We identified 36 relevant studies. A three-stages model of bladder wall remodeling can be hypothesized involving an initial hypertrophy phase, a subsequent compensation phase and a later decompensation. Histological and molecular alterations occur in the following compartments: urothelium, suburothelium, detrusor smooth muscle cells, detrusor extracellular matrix, nerves. Cyclic stretch, increased hydrostatic and cyclic hydrodynamic pressure and hypoxia are stimuli capable of modulating multiple signaling pathways involved in this remodeling process.

CONCLUSIONS

Bladder outlet obstruction leads to progressive bladder tissue remodeling in humans. Multiple signaling pathways are involved.

Activation of bitter taste receptors (tas2rs) relaxes detrusor smooth muscle and suppresses overactive bladder symptoms

Bitter taste receptors (TAS2Rs) are traditionally thought to be expressed exclusively on the taste buds of the tongue. However, accumulating evidence has indicated that this receptor family performs non-gustatory functions outside the mouth in addition to taste. Here, we examined the role of TAS2Rs in human and mouse detrusor smooth muscle (DSM). We showed that mRNA for various TAS2R subtypes was expressed in both human and mouse detrusor smooth muscle (DSM) at distinct levels. Chloroquine (CLQ), an agonist for TAS2Rs, concentration-dependently relaxed carbachol- and KCl-induced contractions of human DSM strips. Moreover, 100 μM of CLQ significantly inhibited spontaneous and electrical field stimulation (EFS)-induced contractions of human DSM strips. After a slight contraction, CLQ (1 mM) entirely relaxed carbachol-induced contraction of mouse DSM strips. Furthermore, denatonium and quinine concentration-dependently decreased carbachol-induced contractions of mouse DSM strips. Finally, we demonstrated that CLQ treatment significantly suppressed the overactive bladder (OAB) symptoms of mice with partial bladder outlet obstruction (PBOO). In conclusion, we for the first time provide evidence of the existence of TAS2Rs in the urinary DSM and demonstrate that TAS2Rs may represent a potential target for OAB. These findings open a new approach to develop drugs for OAB in the future.

Bioinformatic analysis of microRNA-mRNA expression profiles of bladder tissue induced by bladder outlet obstruction in a rat model

Various microRNAs (miRNAs) have previously been demonstrated to exhibit an association with the process of bladder remodeling, induced by bladder outlet obstruction (BOO). However, little is known about miRNA and gene expression profiles and the molecular mechanism underlying bladder pathophysiological alterations. The present study used bioinformatic analysis technology to examine the altered miRNA and mRNA expression profiles of bladder tissue in a rat model of BOO and validate the involved signaling pathways. The gene expression profile data was downloaded from Gene Expression Omnibus (GEO), and the differentially expressed genes (DEGs) and differentially expressed miRNAs (DEMs) were screened. Potential target genes of DEMs were predicted. The target genes and DEGs were used for further gene ontology (GO) analysis followed by Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis using the Database for Annotation, Visualization and Integrated Discovery. The present study additionally constructed a DEM‑DEG interaction network. A total of 9 DEMs (3 upregulated and 6 downregulated) were identified; 664 DEGs were screened. KEGG analysis revealed that the DEGs were involved in the regulation of the actin cytoske-leton, extracellular matrix (ECM) remodeling, cell adhesion and the cell cycle. Additionally, KEGG classification indicated that these genes were important in angiogenesis, and in the p53 and transforming growth factor‑β signaling pathways. Notably, rno‑miRNA (miR)‑26b and rno‑miR‑101b were the two larger nodes of the 7 obstruction‑associated DEMs and interacted with 32 and 27 DEGs, respectively. On removal of obstruction, few DEMs were present; however, 370 genes exhibited the opposite expression trend. The majority of pathways enriched for the DEGs were identified and were associated with ECM‑receptor interaction and focal adhesion. In the DEM‑DEG regulatory network, miR‑495, miR‑494 and their target genes were significantly differentially expressed. The present study demonstrated that miRNAs and genes may be potential biomarkers of bladder remodeling induced by BOO, and additionally provided novel insights into the molecular mechanisms underlying this disorder.

The Obstructed Bladder: Expression of Collagen, Matrix Metalloproteinases, Muscarinic Receptors, and Angiogenic and Neurotrophic Factors in Patients With Benign Prostatic Hyperplasia

OBJECTIVE

To evaluate the gene expression of collagen, matrix metalloproteinases (MMPs) and inhibitors, cholinergic muscarinic receptors (CHRMs), and angiogenic and nerve growth factors (NGFs) in the bladder of patients with bladder outlet obstruction caused by benign prostatic hyperplasia (BPH).

METHODS

We analyzed bladder specimens from 43 patients with obstructive BPH undergoing transurethral resection of the prostate as compared to 10 age-matched controls with an International Prostatic Symptom Score of <8 and a prostate volume of <30 g. A bladder biopsy was performed for relative gene expression analysis with quantitative real-time polymerase chain reaction of collagens I and III, MMP-1, MMP-2, and MMP-9; tissue inhibitors of metalloproteinases (TIMPs) TIMP-1, TIMP-2, and reversion-inducing cysteine-rich protein with kazal motifs (RECK); CHRM2 and CHRM3; VEGF and CD105; and NGF and nerve growth factor receptor (NGFr).

RESULTS

Patients with bladder outlet obstruction presented a statistically significant overexpression of collagens I and III, VEGF, CHRM2, and CHRM3. CD105, MMP-9, and TIMP-1 were underexpressed. Expressions of NGF, NGFr, MMP-1, MMP-2, TIMP-2, and RECK were heterogeneous. CHRM2 and CHRM3 were overexpressed in patients with persistent detrusor overactivity. Smokers presented an upregulation of NGFr and VEGF; dyslipidemic patients had an overexpression of NGFr.

CONCLUSION

Bladder upregulation of collagens I and III on transcriptional level appears to be relevant in BPH. Muscarinic receptors CHRM2 and CHRM3 are also overexpressed, more so in patients with persistent detrusor overactivity. Upregulation of VEGF and NGFr, particularly in subjects with risk factors for atherosclerosis, reinforces the role of ischemia in BPH-induced modifications of the bladder.

Predictors of Improvement in Storage Symptoms at Three Years After 120W GreenLight High Performance System Laser Treatment for Benign Prostate Hyperplasia

PURPOSE

This study was conducted to investigate the indicators of recovery in storage symptoms after GreenLight High Performance System photoselective vaporization of the prostate (HPS-PVP) in men with benign prostate hyperplasia.

METHODS

A total of 155 men with a baseline subtotal storage symptom score of international prostate symptom score (sIPSS) greater than or equal to six, who underwent HPS-PVP and were followed up on for as much as 3 years, were included in this retrospective study. Surgical outcomes were evaluated at 1, 3, 6, 12, 24, and 36 months after surgery. Improvement of storage symptoms was defined as a reduction greater than or equal to 30% of sIPSS after surgery compared to the baseline.

RESULTS

The mean age was 67.5 ± 7.8 years and the preoperative median prostate-specific antigen, mean total prostate volume, and sIPSS were 1.95 (0.97-5.27) ng/mL, 52.1 ± 32.5 mL, and 9.6 ± 2.6, respectively. The mean improvement rate of sIPSS after 3 years was 34.4%. Age was only associated with an improvement of sIPSS in the multivariate analysis (odds ratio = 0.889, p = 0.008). The mean improvement rates of sIPSS according to age group (<65 vs ≥65) were 44.7% and 26.0%, respectively.

CONCLUSIONS

Age can serve as an independent predictor of storage symptom improvement for as much as 3 years. Therefore, we suggest that older patients who are being considered candidates for surgical treatment should be further evaluated.

Benign Prostatic Obstruction Relief in Patients with Lower Urinary Tract Symptoms Suggestive of Benign Prostatic Enlargement Undergoing Endoscopic Surgical Procedures or Therapy with Alpha-Blockers: A Review of Urodynamic Studies

Benign prostatic obstruction (BPO) contributes to the genesis of lower urinary tract symptoms as well as to pathologic remodeling of the lower and upper urinary tract in patients with benign prostate enlargement. Urodynamic studies demonstrate that both medical therapy with alpha-blockers (ABs) and endoscopic surgical procedures provide BPO relief. However, the magnitude of improvement is higher after surgery. Among ABs, silodosin is associated with the highest improvement of bladder outlet obstruction index (BOOI). A complex relationship exists between BOOI improvement and variations of both maximum urinary flow (Q _max) and detrusor pressure. When the reduction of BOOI is small, the improvement of Q _max is clinically irrelevant and the BOOI is mainly influenced by a decrease of detrusor pressure. In contrast, when the magnitude of BOOI reduction is robust, a meaningful improvement of both detrusor pressure and urinary flow is evident. When clustering ABs according to their receptor pharmacologic selectivity and urodynamic efficacy, three subgroups can be identified,with silodosin being the only member of a subgroup characterized by the highest levels of BOOI improvement and α-1A/α-1B receptor affinity ratio.

Increased detrusor collagen is associated with detrusor overactivity and decreased bladder compliance in men with benign prostatic obstruction

Background

This study aimed to investigate the relationship between detrusor collagen content and urodynamic parameters in men with benign prostatic obstruction.

Material and methods

Nineteen consecutive patients undergoing open prostatectomy for bladder outlet obstruction (BOO) due to benign prostatic hyperplasia (BPH) were evaluated. Urodynamic tests were performed in all patients. BOO and detrusor contractility were assessed with the BOO index (BOOI) and the bladder contractility index (BCI), respectively. A bladder fragment was obtained during prostatectomy. Eight cadaveric organ donors composed the control group. Bladder sections were stained with picrosirius red and hematoxylin-eosin. The collagen to smooth muscle ratio (C/M) in the detrusor was measured and its relationship with urodynamic parameters was investigated.

Results

Seven (36.8%) patients were operated on due to lower urinary tract symptoms and 12 (63.2%) had urinary retention. The mean prostate volume was 128.6 cm³ ± 32.3 cm³, the mean BOOI was 76.4 ± 33.0, and the mean BCI was 116.1 ± 33.7. The mean C/M in BPH patients and controls were 0.43 ± 0.13 and 0.33 ± 0.09, respectively (P = 0.042). A negative correlation was shown between C/M and bladder compliance (r = –0.488, P = 0.043). The C/M was increased in BPH patients with detrusor overactivity (DO) compared to those without DO (0.490 ± 0.110 and 0.360 ± 0.130, respectively; P = 0.030) and also in patients with urinary retention (P = 0.002). No correlation was shown between C/M and maximum cystometric capacity, BOOI, or BCI.

Conclusion

Men with BOO/BPH have increased detrusor collagen content which is associated with decreased bladder compliance, detrusor overactivity, and urinary retention.