Partial Bladder Research Articles

β-Adrenoceptor Signaling Activation Improves Bladder Fibrosis by Inhibiting Extracellular Matrix Deposition of Bladder Outlet Obstruction

Background: Partial bladder outlet obstruction (pBOO) causes deposition of extracellular matrix (ECM), promotes bladder fibrosis, and decreases bladder compliance. Methods: To investigate the effect of β-adrenoceptor (ADRB) on the ECM deposition of pBOO rat model and explore its underlying mechanism, human bladder smooth muscle cells (hBSMCs) were exposed to the pathological hydrostatic pressure (100 cm H2O) for 6 h, reverse transcription-polymerase chain reaction (RT-PCR) and western blotting were employed. Then the rats of sham operation and pBOO model were treated with vehicle or ADRB agonists for 3 weeks, and the alterations of the bladder were observed via Masson staining and immunohistochemical analysis. Results: 100 cm H2O hydrostatic pressure significantly upregulated the expression of collagen I (COL1), collagen III (COL3) and fibronectin (FN), and downregulated the expression of ADRB2 and ADRB3 of hBSMCs at 6 h. The agonists of ADRB2 and ADRB3, Formoterol and BRL 37344, decreased COL1 and FN expression of hBSMCs under 100 cm H2O for 6 h compared with the cells exposed to hydrostatic pressure only. As the classic downstream pathways of ADRB, the EPAC pathway inhibited COL1 and FN expression of hBSMCs via regulating SMAD3 and SMAD2 activities, respectively. In pBOO rats, Procaterol (ADRB2 agonist), and Mirabegron (ADRB3 agonist) inhibited the formation of collagen and decreased the expression of FN and COL1 in the bladders of pBOO rats. Conclusions: The bladder fibrosis of pBOO and deposition of hBSMCs ECM under hydrostatic pressure were regulated by ADRB2, and ADRB3 via EPAC/SMAD2/FN and EPAC/SMAD3/COL1 pathways, these findings pave an avenue for effective treatment of pBOO.

Increased Expression of Hypoxia Inducible Factors in Detrusor Fibrosis Due to Partial Bladder Outlet Obstruction in Male Rats

Increased Expression of Hypoxia Inducible Factors in Detrusor Fibrosis Due to Partial Bladder Outlet Obstruction in Male Rats

Local Injection of Stem Cells Can Be a Potential Strategy to Improve Bladder Dysfunction after Outlet Obstruction in Rats.

This study investigates whether hAFSCs can improve bladder function in partial bladder outlet obstruction (pBOO) rats by targeting specific cellular pathways. Thirty-six female rats were divided into sham and pBOO groups with and without hAFSCs single injection into the bladder wall. Cystometry, inflammation/hypoxia, collagen/fibrosis/gap junction proteins, and smooth muscle myosin/muscarinic receptors were examined at 2 and 6 weeks after pBOO or sham operation. In pBOO bladders, significant increases in peak voiding pressure and residual volume stimulated a significant upregulation of inflammatory and hypoxic factors, TGF-β1 and Smad2/3. Collagen deposition proteins, collagen 1 and 3, were significantly increased, but bladder fibrosis markers, caveolin 1 and 3, were significantly decreased. Gap junction intercellular communication protein, connexin 43, was significantly increased, but the number of caveolae was significantly decreased. Markers for the smooth muscle phenotype, myosin heavy chain 11 and guanylate-dependent protein kinase, as well as M2 muscarinic receptors, were significantly increased in cultured detrusor cells. However, hAFSCs treatment could significantly ameliorate bladder dysfunction by inactivating the TGFβ-Smad signaling pathway, reducing collagen deposition, disrupting gap junctional intercellular communication, and modifying the expressions of smooth muscle myosin and caveolae/caveolin proteins. The results support the potential value of hAFSCs-based treatment of bladder dysfunction in BOO patients.

Ex vivo Study of Partial Bladder Resection in a Porcine Model.

Partial cystectomy aims to preserve bladder function, yet its urodynamic impacts remain unclear. We investigate these effects using an ex vivo porcine model, evaluating bladder volume, compliance, and wall thickness, alongside with thermal damage after bi- and monopolar resection. Within an artificial human pelvis, we conducted partial bladder wall resections (5 cm2, 10 cm2). Urodynamic tests and sonography assessed volume, compliance, and thickness changes. Traction force for catheter retrieval and thermal collagen destruction were measured. Bladder compliance decreased by 1.12 and 1.5 after 5 cm2 and 10 cm2 resections, respectively, with volume reductions of 3-6% and 10-18%. Wall thickness decreased by 20% and 30% post-resection. Comparable thermal damage was observed with mono- and bipolar resection methods. Our study outlines urodynamic impacts and technical considerations of partial cystectomy, affirming its endoscopic feasibility while highlighting potential bladder dysfunction risks.

The Lebanese percreta group: A retrospective cohort study of both radical and conservative management outcomes of abnormally invasive placenta.

The aim of the present study was to illustrate the outcomes of abnormally invasive placenta (AIP) cases managed in three leading centers in Lebanon. We conducted a retrospective multicenter cohort study. Patients managed conservatively (cesarean delivery with successful placental separation) or radically (cesarean hysterectomy) were included in the study. Data included patient characteristics, surgical outcomes (blood loss, operative time, transfusion, partial bladder resection), maternal outcomes (death, length of stay, ICU admission, postoperative hemoglobin level) and neonatal outcomes (Apgar score, neonatal weight, admission to neonatal intensive care unit, neonatal death). The study included 189 patients. In the radical treatment subgroup (141/189), patients were para 3 and delivered at 34 4/7 weeks in average, bled 1.5 L and were transfused with three packed red blood cells, with operative time averaging 160 min. A total of 36% were admitted to the ICU and patients stayed on average for 1 week despite partial bladder resection in 19% of cases. Unscheduled radical delivery occurred at a lower gestational age, was associated with more blood loss, higher rate and volume of transfusion, and risk of maternal and neonatal death. In addition, patients delivered in an unscheduled fashion experienced higher rates of partial bladder resection and longer interventions. In the conservative treatment subgroup, on average patients were para 2 and delivered at 36 weeks, bled 800 mL on average with low rates of transfusion (35%) and ICU admission (22.9%). With regard to neonatal outcomes, the average neonatal birth weight was 2.4 kg in the radical subgroup and 2.5 kg in the conservative subgroup. Neonatal death occurred in 5.4% of cases requiring radical management while it occurred in 2% of patients treated conservatively. Through their multidisciplinary approach, the three centers demonstrated that management of AIP in Lebanon has led to excellent outcomes with no maternal mortality occurring in scheduled radical treatment. By comparison of the three leading centers, pitfalls in each center were identified and addressed.

A case of inguinal hernia with partial bladder herniation

A case of inguinal hernia with partial bladder herniation

Detrusor Overactivity After Partial Bladder Outlet Obstruction Is Associated With High Urinary Adenosine Triphosphate Levels in Female Wistar Rats.

Bladder outlet obstruction (BOO) commonly causes detrusor overactivity (DO). In this study, a post hoc analysis of previous obtained data, we investigate if DO occurring in initial phases of BOO is associated with changes in urinary adenosine triphosphate (ATP) levels. Adult female Wistar rats were submitted to partial BOO (pBOO) or to sham obstruction. Cystometry was performed at 3 or 15 days after pBOO and saline voided was collected for ATP determination. Normality was tested using Shapiro-Wilk test. The mean frequency of voiding contractions (VCs) of the sham-operated animals at 15 days after surgery, plus or minus 3 standard deviations, was used to represent the normal range. Statistical analyses were performed using the chi-square and Mann-Whitney tests. DO was indicated by a VC frequency greater than or equal to 0.9 VCs/min. DO was observed in 63% of animals at 3 days and in 33% at 15 days following pBOO. ATP levels were significantly higher in rats with DO compared to those without DO. The DO phenotype, occurring in the initial phases of BOO, is associated with comparatively high urinary ATP levels.

Robotic Assisted En-Bloc Removal of Kidney, Ureter and Bladder Wall for Endometriosis

To highlight a case where a nephroureterectomy and partial bladder cystectomy needed to be done due to endometriosis. A video article demonstrating a case study and the surgical management. Ureteral endometriosis is a complex form of endometriosis [1]. If left untreated, the ureter can become significantly compressed leading to hydroureter, hydronephrosis and complete loss of kidney function [2]. This is a case of a 29-year-old patient with pelvic pain and cyclical rectal bleeding. Further investigation showed significant left hydronephrosis and almost complete loss of left kidney function (8% on renogram). MRI revealed endometriosis involving the posterior bladder wall and distal left ureter, a large full-thickness sigmoid nodule and a large left endometrioma. The patient underwent a robotic-assisted left nephroureterectomy, partial cystectomy (bladder), excision of pelvic endometriosis and sigmoid resection. This procedure was performed jointly with the gynecologist, urologist, and colorectal surgeon and the SOSURE technique was employed [3]. The specimen (left kidney, whole length of ureter and bladder wall around ureteric orifice) was removed en-bloc through a small 3cm extension of the umbilical incision. As the distance between the sigmoid nodule and the anal verge was 35cm, which was above the limit of the transanal circular stapler, a limited resection was performed over a discoid excision. The patient made a good recovery postoperatively. Ureteral endometriosis is an indolent and aggressive condition which can lead to silent kidney loss. It is essential that hydronephrosis and hydroureter is ruled out in cases with deep endometriosis. Isolated hydronephrosis should also prompt a suspicion for endometriosis.

Targeting Thbs1 reduces bladder remodeling caused by partial bladder outlet obstruction via the FGFR3/p-FGFR3 pathway.

Partial bladder outlet obstruction (pBOO) may lead to bladder remodeling, including fibrosis and extracellular matrix (ECM) deposition. Despite the extensive research on the mechanisms underlying pBOO, potential therapeutic targets for the treatment of pBOO require further research. Dysregulated expression of thrombospondin-1 (Thbs1) has been reported in various human fibrotic diseases; however, its relationship with pBOO remains unclear. Investigate the effects of Thbs1 on bladder remodeling caused by pBOO. We established a pBOO model in Sprague-Dawley rats and performed urodynamic analyses to estimate functional changes in the bladder, validated the histopathological changes in the bladder by using haematoxylin-eosin and Masson's trichrome staining, identified key target genes by integrating RNA sequencing(RNA-seq) and bioinformatics analyses, validated the expression of related factors using Western blot analysis and RT-qPCR, and used immunofluorescence staining to probe the potential interaction factors of Thbs1. Urodynamic results showed that pressure-related parameters were significantly increased in rats with pBOO. Compared with the sham group, the pBOO group demonstrated significant increases in bladder morphology, bladder weight, and collagen deposition. Thbs1 was significantly upregulated in the bladder tissues of rats with pBOO, consistent with the RNA-seq data. Thbs1 upregulation led to increased expression of matrix metalloproteinase (MMP) 2, MMP9, and fibronectin (Fn) in normal human urinary tract epithelial cells (SV-HUC-1), whereas anti-Thbs1 treatment inhibited the production of these cytokines in TGF-β1-treated SV-HUC-1. Further experiments indicated that Thbs1 affected bladder remodeling in pBOO via the fibroblast growth factor receptor 3 (FGFR3) pathway. Thbs1 plays a crucial role in bladder remodeling caused by pBOO. Targeting Thbs1 might alleviate ECM damage. Mechanistically, Thbs1 may function via the FGFR signaling pathway by regulating the FGFR3 receptor, identified as the most relevant disease target of pBOO, and FGF2 may be a mediator. These findings suggest that Thbs1 plays a role in BOO development and is a therapeutic target for this condition.

Excitatory purinergic and cholinergic expression changed in a partial bladder outlet obstruction-induced overactive bladder rat model

Overactive bladder (OAB) is a common, long-term symptom complex with a high prevalence in women worldwide. OAB has caused a social burden, and effective treatments are urgently needed. However, the pathogenesis of OAB has yet to be elucidated. Model rats underwent bladder outlet obstruction surgery. In the 2nd, 3rd, and 4th weeks after surgery, metabolic cages were used to detect the 12 h urine volume of rats in the sham and model groups. The urodynamic parameters bladder leak point pressure (BPLL), maximum voiding pressure (MVP), residual volume (RV), maximum bladder capacity (MBC), bladder compliance (BC), voided efficiency (VE), and non-voiding contractions (NVCs) were also detected. Moreover, the contractile responses of isolated detrusor muscles to electrical and carbachol stimulation were examined at the abovementioned time points. At the 4th week after surgery, the bladders of both groups were obtained for hematoxylin–eosin (H&E) and Masson’s trichrome staining. Real-time qPCR and Western blot were performed to quantify the expression of choline acetyltransferase (ChAT) and solute carrier family 17 member 9 (SLC17A9). At week 4, compared with the sham group, the 12 h urine volume of PBOO group increased significantly. The BLPP, MVP, VE, MBC, and NVCs increased significantly, and the VE was significantly reduced in 4-week PBOO group. The contractile responses of isolated detrusor muscles to electrical and carbachol stimulation significantly increased in 4-week PBOO group. In the 4-week PBOO group, the bladder wall and the ratio of bladder muscle to collagen within the bladder smooth muscle layer wall were significantly higher than those in the sham group. ChAT and SLC17A9 mRNA and protein expression in the OAB model rats significantly increased. At 4 weeks after PBOO, the OAB model was successfully established. The gene and protein expression levels of ChAT and SLC17A9 increased in the bladder of the OAB model, suggesting that OAB may be related to increased excitatory purinergic and cholinergic expression.

ARTIA-Bladder: Daily Online Adaptive Short-Course Radiation Therapy (RT) and Concurrent Chemotherapy for Muscle-Invasive Bladder Cancer (MIBC): A Prospective Trial of an Individualized Approach for Reducing Bowel and Bladder Toxicity

Concurrent chemo-radiotherapy is commonly prescribed for muscle-invasive bladder cancer (MIBC). Post hoc analysis of two large, randomized trials found that hypofractionation improves loco-regional control (LRC) vs. standard fractionation in this population. A challenge in traditional image-guided radiotherapy of the bladder is that daily changes in bladder position and size requires large margins to ensure target coverage. This makes it difficult to spare uninvolved bladder from high-dose treatment, increases the risk of bowel toxicity, and results in historical rates of acute G3+ toxicity exceeding 20-30%. Daily online adaptive RT (ART) may enable reduced, personalized margins that maintain target coverage while reducing dose to OARs. This prospective clinical trial will test whether: 1) participants undergoing ART for MIBC have a lower rate of acute G3+ GI/GU toxicity compared with the 31% historical control rate (Stage III BC2001 trial), and 2) 2-year LRC with ART will be non-inferior to historical controls (75%). This multi-national trial will enroll 165 adult subjects with stage cT2-T4aN0M0 urothelial MIBC. Subjects will have undergone an attempt at maximal transurethral resection of bladder tumor. Patients with clinically involved nodes or G2+ GI or G3+ GU symptoms/conditions at baseline are ineligible. Concurrent with chemotherapy, participants will receive (at the discretion of the investigator) either 55 Gy in 20 fx to whole-bladder or 46 Gy in 20 fx to whole-bladder plus simultaneous in-field boost of 55 Gy in 20 fx to tumor bed. A personalized ITV will be derived for each subject based on bladder expansion, as assessed on two CT simulations separated by 30 min. Daily ART will be attempted for all subjects. The primary endpoint is acute G3+ GI/GU toxicity. Secondary endpoints are LRC; quality of life (EORTC QLQ-BLM30, EPIC 26 bowel and urinary); global function (EQ-5D-5L ); 2-year disease-free, bladder intact event-free, and overall survival; 2-year bladder cancer-specific mortality; NTCP model of acute GI toxicity for hypofractionated bladder RT; workflow feasibility of ART; improved target coverage ± reduced dose to critical OARs vs. non-ART dosimetry; acute G3+ GI/GU toxicity rate in subjects with ≥75% of their treatments as ART; and acute G3+ GI/GU toxicity in the cohort treated with partial bladder boost. Exploratory translational and correlative endpoints will also be examined. This trial opened to enrollment on Feb 2, 2023; the study duration is expected to be 4-5 years. This prospective clinical trial will provide robust clinical data to inform healthcare providers' decisions on the use of daily online ART and hypofractionation as a bladder preservation strategy for this population.

Spontaneous urinary bladder regeneration after subtotal cystectomy increases YAP/WWTR1 signaling and downstream BDNF expression: Implications for smooth muscle injury responses.

Rodents have the capacity for spontaneous bladder regeneration and bladder smooth muscle cell (BSMC) migration following a subtotal cystectomy (STC). YAP/WWTR1 and BDNF (Brain-derived neurotrophic factor) play crucial roles in development and regeneration. During partial bladder outlet obstruction (PBO), excessive YAP/WWTR1 signaling and BDNF expression increases BSMC hypertrophy and dysfunction. YAP/WWTR1 and expression of BDNF and CYR61 were examined in models of regeneration and wound repair. Live cell microscopy was utilized in an ex vivo model of STC to visualize cell movement and division. In Sprague-Dawley female rats, STC was performed by resection of the bladder dome sparing the trigone, followed by closure of the bladder. Smooth muscle migration and downstream effects on signaling and expression were also examined after scratch wound of BSMC with inhibitors of YAP and BDNF signaling. Sham, PBO and incision (cystotomy) were comparators for the STC model. Scratch wound in vitro increased SMC migration and expression of BDNF, CTGF and CYR61 in a YAP/WWTR1-dependent manner. Inhibition of YAP/WWTR1 and BDNF signaling reduced scratch-induced migration. BDNF and CYR61 expression was elevated during STC and PBO. STC induces discrete genes associated with endogenous de novo cell regeneration downstream of YAP/WWTR1 activation.

METTL3-dependent m6A modification mediates bladder remodeling after partial bladder outlet obstruction through CCN2 activation.

N6-methyladenosine (m6A) modification is a critical posttranscriptional event in gene regulation. Thus, identifying methyltransferase, demethylase, or m6A binding protein-mediated m6A modifications in cancer or noncancer transcriptomes has become a promising novel strategy for disease therapy development. However, novel insights into m6A modification in partial bladder outlet obstruction (pBOO) and detailed information about the drivers of bladder remodeling remain to be elucidated. Here, we first characterized the m6A modification landscape in pBOO and investigated potential actionable pharmaceutical targets for future therapies. We generated an improved animal model of pBOO in SD rats with urethral meatus stricture induced by suturing. Urodynamic investigations and cystometry were carried out to evaluate the physiologic changes elicited by pBOO. Whole-transcriptome sequencing (RNA-seq) and m6A-modified RNA immunoprecipitation sequencing (MeRIP-seq) were subsequently performed to analyze the expression pattern associated with bladder remodeling in pBOO. The cystometric evaluation of bladder function demonstrated obvious increases in pressure-related parameters in the pBOO group. Hematoxylin and eosinstaining and Masson's trichrome staining validated the occurrence of bladder remodeling. A global elevation in m6A RNA methylation levels was observed in parallel to a increased expression of METTL3 in the pBOO group. High-throughput sequencing revealed the differences in expression patterns between the pBOO and sham-operated groups. Furthermore, potential m6A-modified genes, including CCN2, may serve as new pharmaceutical targets to reverse bladder remodeling. Exploring the roles of m6A-modified genes identified as associated with bladder remodeling by integrating RNA-seq and MeRIP-seq data can offer new insights for developing promising treatments for pBOO patients.

Trimodal Therapy Using an MR–guided Radiation Therapy Partial Bladder Tumor Boost in Muscle Invasive Bladder Cancer

Bladder preservation with trimodal therapy (TMT; maximal tumor resection followed by chemoradiation) is an effective paradigm for select patients with muscle invasive bladder cancer. We report our institutional experience of a TMT protocol using nonadaptive magnetic resonance imaging-guided radiation therapy (MRgRT) for partial bladder boost (PBB). A retrospective analysis was performed on consecutive patients with nonmetastatic muscle invasive bladder cancer who were treated with TMT using MRgRT between 2019 and 2022. Patients underwent intensity modulated RT-based nonadaptive MRgRT PBB contoured on True fast imaging with steady state precession (FISP) images (full bladder) followed sequentially by computed tomography-based RT to the whole empty bladder and pelvic lymph nodes with concurrent chemotherapy. MRgRT treatment time, table shifts, and dosimetric parameters of target coverage and normal tissue exposure were described. Prospectively assessed acute and late genitourinary and gastrointestinal (GI) toxicity were reported. Two-year local control was assessed with Kaplan-Meier methods. Seventeen patients were identified for analysis. PBB planning target volume margins were ≤8 mm in 94% (n=16) of cases. Dosimetric target coverage parameters were favorable and all normal tissue dose constraints were met. For MRgRT PBB fractions, median table shifts were 0.4 cm (range, 0-3.15), 0.45 cm (0-2.65), and 0.75 cm (0-4.8) in the X, Y, and Z planes, respectively. Median treatment time for MRgRT PBB fractions was 9 minutes (range, 6.9-17.4). We identified 32 out of 100 total MRgRT fractions that may have benefitted from online adaptation based on changes in organ position relative to planning target volume, predominantly because of small bowel (13/32, 41%) or rectum (8/32, 25%). Two patients discontinued RT prematurely. The incidence of highest-grade acute genitourinary toxicity was 1 to 2 (69%) and 3 (6%), whereas the incidence of acute GI toxicity was 1 to 2 (81%) and 3 (6%). There were no late grade 3 events; 17.6% had late grade 2 cystitis and none had late GI toxicity. With median follow-up of 18.2 months (95% CI, 12.4-22.5), the local control rate was 92%, and no patient has required salvage cystectomy. Nonadaptive MRgRT PBB is feasible with favorable dosimetry and low resource utilization. Larger studies are needed to evaluate for potential benefits in toxicity and local control associated with this approach in comparison to standard treatment techniques.

V-048 COMBINED ETEP AND OPEN APPROACH FOR M4 AND L3 VENTRAL HERNIA AFTER COMPLICATED INGUINAL HERNIA REPAIR

Abstract We present the case of a 49 y-o woman with a previous open inguinal hernia repair with a superficial surgical site infection during the immediate postoperative period. She required surgical debridement and negative pressure therapy. Ten months after surgery she persisted with discharge and inflammatory changes. The preoperative CT-scan revealed a misplaced mesh with chronic inflammatory changes in the right inguinal and hypogastric region. An M4 3,5cm diameter defect with a right lateralized 13×5×10cm hernia sac was also observed. A combined open and eTEP approach for mesh removal and retrorectus hernia repair was proposed. Retrorectus dissection began at the left rectus muscle, using two 5 mm trocars for dissection and after crossover a contralateral Hasson trocar was placed. A M4-5W2 and L3 hernia with omental fat and partial bladder sliding into the hernia sac was observed. The right posterior fascia was fibrotic and laterally retracted. After sac contents were fully mobilized, a right partial TAR was necessary in order to close the peritoneum and obtain an adequate dissection for mesh placement. A 25×20cm polypropylene mesh was placed in the retrorectal space. Using a right inguinal incision, previously infected mesh was removed and a silver coated polypropylene mesh was placed below the anterior fascia. The patient was discharged on the third postoperative day and her one month follow up visit was uneventful. We conclude that in this case a hybrid approach can provide an adequate mesh placement via eTEP, with mesh removal by a less invasive approach.

MP03-19 ROLE OF MICROFIBRILLAR-ASSOCIATED PROTEIN 4 IN PARTIAL BLADDER OUTFLOW OBSTRUCTION-RELATED BLADDER FIBROSIS

You have accessJournal of UrologyCME1 Apr 2023MP03-19 ROLE OF MICROFIBRILLAR-ASSOCIATED PROTEIN 4 IN PARTIAL BLADDER OUTFLOW OBSTRUCTION-RELATED BLADDER FIBROSIS Reine Kanaan, Anders Schlosser, Grith Lykke Sorensen, and Peter Zvara Reine KanaanReine Kanaan More articles by this author , Anders SchlosserAnders Schlosser More articles by this author , Grith Lykke SorensenGrith Lykke Sorensen More articles by this author , and Peter ZvaraPeter Zvara More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003214.19AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Partial bladder outflow obstruction (pBOO) causes remodeling of the bladder wall, with smooth muscle hypertrophy and an excessive deposition of extracellular matrix (ECM) proteins, leading to bladder fibrosis. Our understanding of the pathophysiology of this process is limited and no effective treatment to prevent or reverse bladder fibrosis exists. Microfibrillar-associated protein 4 (MFAP4) is an ECM glycoprotein, localized to elastic fiber-rich regions. It binds ECM components including elastin and collagen and contributes to the process of elastogenesis in healthy tissues. Emerging data suggest the involvement of MFAP4 in the pathogenesis of disease-induced tissue remodeling, including fibrosis. To determine its value as a potential therapeutic target, we compared MFAP4 expression in sham-operated bladders to bladders 6 weeks following pBOO. MFAP4 levels were then correlated with bladder function. METHODS: Partial BOO, was induced in 9 male Sprague Dawley rats, 5 underwent sham surgery. Six weeks following surgery, rats were placed in a metabolic cage overnight to record 12-hour micturition frequency and volume per void. Gene expression levels of MFAP4, alpha-smooth muscle actin (α-SMA) and collagen I were quantified in the bladder tissue using real-time PCR. RESULTS: The bladder/body ratio was significantly higher in the pBOO group (0.07±0.04) when compared to the SHAM group (0.024±0.003). Obstructed rats with increased MFAP4 expression demonstrated an increase in α-SMA expression. No significant increase in collagen I levels was recorded in the pBOO group. Animals with bladder overactivity as determined by frequent low volume micturitions (≥4 micturitions with <0.1 mL per void/12 hours) had higher MFAP4 expression than animals in the SHAM group, which exhibited normal micturition pattern. CONCLUSIONS: These initial observations show that pBOO lasting 6 weeks results in detrusor hypertrophy. Although bladder wall fibrosis did not develop within the 6-week timeframe, our data suggest that bladder remodeling following pBOO is associated with increased MFAP4 levels and that MFAP4 might be involved in the pathogenesis of pBOO-induced bladder dysfunction. Experiments addressing processes extending beyond 6 weeks post-pBOO and possible involvement of MFAP4 in their pathophysiology are ongoing. Source of Funding: Odense University hospital © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e31 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Reine Kanaan More articles by this author Anders Schlosser More articles by this author Grith Lykke Sorensen More articles by this author Peter Zvara More articles by this author Expand All Advertisement PDF downloadLoading ...

Establishment of an overactive bladder model in mice

BackgroundOveractive bladder (OAB) is a syndrome characterized by symptoms of urinary urgency, often accompanied by frequent urination and nocturia or urge incontinence.MethodsTwenty female ICR mice were randomly divided into pBOO (partial bladder outlet obstruction) and control groups. The mouse OAB model was constructed by ligating the bladder outlet. Eight weeks after the operation, the methods of voiding spot on paper (VSOP), isolated detrusor muscle, and HE staining were used for analysis and research.ResultsAfter the operation, two mice in the experimental and one in control died, and one in the control groups had an abnormal bladder size, so it was excluded from the statistical analysis. Eight weeks after the operation, there was an insignificant difference (P = 0.15) in the body weight of mice in the pBOO (26.54 ± 2.62 g) and the control group (24.84 ± 1.76 g). The number of urinations in 12 h was significantly higher (P < 0.001) in the pBOO (7.63 ± 1.19) than in the control group (4.13 ± 0.99). Also, the 12-h urine volume of pBOO (1491.23 ± 94.72 μL) was significantly greater (P = 0.006) than that of the control group (1344.86 ± 88.17 μL). The isolated bladder of the pBOO mice was significantly heavier than that in the control group (53.16 ± 1.79 mg vs. 24.54 ± 1.80 mg, P < 0.001), the horizontal and vertical length of the bladder in pBOO group were larger than those in the control group (P < 0.001). The detrusor thickness of pBOO group (357.50 ± 11.88 µm) was significantly thicker than that of control group (258.52 ± 17.22 µm, P < 0.001), and the isolated muscle strip was more sensitive to carbachol stimulation. According to HE staining, the bladder wall of the pBOO mice was significantly thickened.ConclusionsA pBOO-mediated mouse OAB model was successfully established by ligating the bladder outlet.

Pathophysiological analysis of detrusor overactivity following partial bladder outlet obstruction

Pathophysiological analysis of detrusor overactivity following partial bladder outlet obstruction

HucMSC exosomes attenuate partial bladder outlet obstruction-induced renal injury and cell proliferation via the Wnt/β-catenin pathway

Bladder outlet obstruction (BOO) can cause serious complications including kidney damage; nevertheless, there are currently no animal models for studying BOO-induced kidney damage. Mesenchymal stem cells (MSCs) are widely used in therapeutic studies of renal fibrosis. However, MSC-derived exosomes show improved safety profile and more controllable characteristics compared with those of MSCs. Herein, we established a kidney injury mouse model of partial bladder outlet obstruction (PBOO) and evaluated the effects of human umbilical cord MSC-derived exosomes (hucMSC-Exos) on PBOO-induced reflux kidney injury in this model. Exosomes were isolated from a hucMSC-conditioned medium, purified by ultracentrifugation, and examined. Living image was performed to indicate the distribution of hucMSC-Exos. The PBOO-treated mice interacted with PBS (phosphate-buffered saline) or hucMSC-Exos. Morphologic changes and expression of interstitial-fibrosis—related, cell proliferation and Wnt/β-catenin signaling-pathway indices were evaluated. At 7 days after induction of PBOO, structural destruction of renal tubules was observed. Expression of the interstitial markers and the cellular-proliferation index increased significantly in the PBOO group compared with the control group. The isolated exosomes were 30–150 nm in diameter, showing a round shape and bilayer membrane structure with CD63, TSG101, Alix expressed, enriched in the kidney of the PBOO group. Administering hucMSC-Exos to post-PBOO mice reversed renal injury and suppressed expression of Wnt/β-catenin signaling pathway-related proteins. hucMSC-Exos inhibited PBOO-induced kidney injury and cellular proliferation and suppressed the Wnt/β-catenin signaling pathway. Our findings will spur the development of novel hucMSC-Exo-mediated therapies for treating patients with renal fibrosis.

Molecular Characterization of Non-Neurogenic and Neurogenic Lower Urinary Tract Dysfunction (LUTD) in SCI-Induced and Partial Bladder Outlet Obstruction Mouse Models.

We examined bladder function following spinal cord injury (SCI) by repeated urodynamic investigation (UDI), including external urethral sphincter (EUS) electromyography (EMG) in awake restrained mice and correlated micturition parameters to gene expression and morphological changes in the bladder. A partial bladder outlet obstruction (pBOO) model was used for comparison to elucidate both the common and specific features of obstructive and neurogenic lower urinary tract dysfunction (LUTD). Thirty female C57Bl/6J mice in each group received an implanted bladder catheter with additional electrodes placed next to the EUS in the SCI group. UDI assessments were performed weekly for 7 weeks (pBOO group) or 8 weeks (SCI group), after which bladders were harvested for histological and transcriptome analysis. SCI mice developed detrusor sphincter dyssynergia (DSD) one week after injury with high-pressure oscillations and a significantly increased maximal bladder pressure Pmax and were unable to void spontaneously during the whole observation period. They showed an increased bladder-to-bodyweight ratio, bladder fibrosis, and transcriptome changes indicative of extracellular matrix remodeling and alterations of neuronal signaling and muscle contraction. In contrast, pBOO led to a significantly increased Pmax after one week, which normalized at later time points. Increased bladder-to-bodyweight ratio and pronounced gene expression changes involving immune and inflammatory pathways were observed 7 weeks after pBOO. Comparative transcriptome analysis of SCI and pBOO bladders revealed the activation of Wnt and TGF-beta signaling in both the neurogenic and obstructive LUTD and highlighted FGF2 as a major upregulated transcription factor during organ remodeling. We conclude that SCI-induced DSD in mice leads to profound changes in neuronal signaling and muscle contractility, leading to bladder fibrosis. In a similar time frame, significant bladder remodeling following pBOO allowed for functional compensation, preserving normal micturition parameters.