[Pirfenidone alleviates urethral stricture following urethral injury in rats by suppressing TGF-ß1 signaling and inflammatory response].

OBJECTIVE: To investigate the effect of pirfenidone for reducing urethral stricture following urethral injury in rats and explore the possible mechanism. METHODS: Thirty male SD rats were randomly assigned into negative control group, positive control group and pirfenidone group (n=10). In pirfenidone and positive control groups, the rats were subjected to incision of the posterior urethral cavernous body followed by daily intraperitoneal injection of pirfenidone (100 mg/kg) and an equivalent volume of solvent, respectively. The rats in the negative control group were given intraperitoneal injections of solvent without urethral injury. At two weeks after modeling, retrograde urethrography was performed for observing urethral stricture, and the injured urethral tissues were harvested for HE staining, Masson staining, immunohistochemical staining and Western blotting for detecting the protein expressions of α-SMA and TGF-ß1. The mRNA expressions of the inflammatory factors TNF-α, IL-6, and IL-1ß were detected using qRT-PCR. RESULTS: The body weight of the rats in pirfenidone group was significantly decreased compared with that in the other two groups (P < 0.05). Retrograde urethrography showed significant narrowing of the urethra in the positive control group but not in the pirfenidone group. HE staining of the injured urethral tissues showed obvious proliferation of urethral epithelial cells with narrow urethral cavity and increased inflammatory cells in positive control group. The pathological findings of the urethra were similar between pirfenidone group and the negative control group. Masson staining revealed obviously reduced collagen fibers and regular arrangement of the fibers in pirfenidone group as compared to the positive control group. Compared with those in the negative control group, the expressions of α-SMA and TGF-ß1 were significantly increased in the positive control group, and pirfenidone treatment significantly inhibited their expressions (P < 0.05 or 0.01). Pirfenidone also significantly inhibited the mRNA expressions of TNF-α, IL-6, and IL-1ß in the injured urethral tissue (P < 0.05 or 0.01). CONCLUSION: Pirfenidone can prevent urethral fibrosis and stricture after urethral injury possibly by inhibiting the TGF-ß1 pathway and inflammatory response.

Differential expression of miRNAs involved in biological processes responsible for inflammation and immune response in lichen sclerosus urethral stricture disease.

PURPOSE: To better understand the pathophysiology of lichen sclerosus (LS) urethral stricture disease (USD), we aimed to investigate expression profiles of microRNAs (miRNAs) in tissue samples from men undergoing urethroplasty. METHODS: Urethral stricture tissue was collected from 2005-2020. Histologic features diagnostic of LS were the basis of pathologic evaluation. Foci of areas diagnostic for LS or non-LS strictures were chosen for RNA evaluation. In an initial screening analysis, 13 LS urethral strictures and 13 non-LS strictures were profiled via miRNA RT-qPCR arrays for 752 unique miRNA. A validation analysis of 23 additional samples (9 LS and 14 non-LS) was performed for 15 miRNAs. Statistical analyses were performed using SPSS v25. Gene Ontology (GO) analysis was performed using DIANA-mirPath v. 3.0. RESULTS: In the screening analysis 143 miRNAs were detected for all samples. 27 were differentially expressed between the groups (false discovery p-value <0.01). 15 of these miRNAs individually demonstrated an area under the curve (AUC)>0.90 for distinguishing between between LS and non-LS strictures. 11-fold upregulation of MiR-155-5p specifically was found in LS vs. non-LS strictures (p<0.001, AUC = 1.0). In the validation analysis, 13 of the 15 miRNAs tested were confirmed to have differential expression (false discovery p-value <0.10). CONCLUSIONS: To our knowledge this is the first study evaluating miRNA expression profiles in LS and non-LS USD. We identified several miRNAs that are differentially expressed in USD caused by LS vs other etiologies, which could potentially serve as biomarkers of LS USD. The top eight differentially expressed miRNAs have been linked to immune response processes as well as involvement in wound healing, primarily angiogenesis and fibrosis.

Familial Urethral Stricture, Five Adult Patients Overview.

Congenital stricture, specifically with manifestation in adulthood is extremely a rare cause of urethral stricture and is not associated with known etiologies. It was first described by Cobb et al., and to our knowledge only 5 families were reported in English literatures to have familial urethral stricture.We report two families with urethral stricture including five male patients referred to our tertiary reconstructive urology department during 1994 to 2017. The age and severity of symptoms at presentation are variable; as are the surgical interventions required. There are no phylogenetic, familiar or racial relationship between the two families described.

miR-21 modification enhances the performance of adipose tissue-derived mesenchymal stem cells for counteracting urethral stricture formation.

The treatment of complicated long segment strictures remains to a challenge, and the substitution urethroplasty treatment is often accompanied by subsequent tissue fibrosis and secondary stricture formation. In situ injection of human adipose tissue-derived stem cells (hADSC) could potential be applied for prevention of urethral fibrosis, but the cells transplantation alone may be insufficient because of the complicated histopathological micro-environmental changes in the injury site. This study investigated whether miR-21 modification can improve the therapeutic efficacy of ADSCs against urethral fibrosis to limit urethral stricture recurrence. MiR-21-modified ADSCs (miR-21) were constructed via lentivirus-mediated transfer of pre-miR-21 and GFP reporter gene. In vitro results suggested that miR-21 modification can increase the angiogenesis genes expression of ADSCs and enhance its anti-oxidative effects against reactive oxygen species (ROS) damage. In vivo results showed that miR-21 modification contributes to increased urodynamic parameters and better formation of the epithelium and the muscle layer as compared to ADSCs transplantation alone groups. The results demonstrated that miR-21 modification in ADSCs could improve urethral wound healing microenvironment, enhance stem cell survival through ROS scavenging and promote the neovascularization via regulating angiogenic genes expression, which eventually increase the ADSCs' therapeutic potential for urethral wound healing.

microRNA expression profiles of scar and normal tissue from patients with posterior urethral stricture caused by pelvic fracture urethral distraction defects.

Pelvic fracture urethral distraction defect (PFUDD) seriously affects the quality of life of patients. At present, there are few effective drug treatments available for PFUDD­induced urethral stricture, which is associated with fibrosis and scar formation in urethra lumen. Emerging evidence suggests that microRNAs (miRNAs/miRs) may be involved in the regulation of fibrosis, and analysis of miRNA expression profiles in urethral scar and normal urethra tissues may therefore benefit the discovery of novel treatments for urethral stricture with micro invasive procedures. In the present study, miRNA sequencing and quantitative polymerase chain reaction (qPCR) validation using paired scar and normal tissues from patients with PFUDD, and functional analysis of the miRNAs involved in the fibrosis associated signaling pathway was performed. A total of 94 differentially expressed miRNAs were identified in the scar tissue of patients with PFUDD. Among them, 26 miRNAs had significantly altered expression in the scar tissue compared with the normal tissue from the same patient. qPCR validation confirmed that miR­129­5p was overexpressed in scar tissue. The TGF­ß pathway­associated functions of a total of 5 miRNAs (hsa­miR­129­5p, hsa­miR­135a­5p, hsa­miR­363­3p, hsa­miR­6720­3p and hsa­miR­9­5p) were further analyzed, as well as their key molecular targets and functional mechanisms in signaling regulation. To conclude the miRNA sequencing indicated a significantly altered expression of hsa­miR­129­5p, hsa­miR­135a­5p, hsa­miR­363­3p, hsa­miR­6720­3p and hsa­miR­9­5p in patients with PFUDD. These miRNAs and their potential target genes were associated with fibrosis in several diseases, and the data from the present study may help explore potential miRNA targets for future precision treatments for urethral stricture.

Impact of Altered WNT2B Expression on Bladder Wall Fibroblasts: Implications for Apoptosis Regulation in the Stroma of the Lower Urinary Tract.

BACKGROUND: Little is known about the role of WNT signalling in pathological processes involving the urinary tract stroma. Here the impact of WNT signalling on bladder wall fibroblasts (BWFs) was studied using integrated expression profiling. MATERIAL AND METHODS: WNT ligand and downstream WNT pathway component expression was profiled in human BWFs using qRT-PCR. Highly expressed WNT2B was knocked down using siRNA in BWFs. The expression of 730 mRNAs and 800 miRNAs was analyzed on the nCounter MAX platform in #WNT2B and control transfected BWFs. qRT-PCR was used for validation in vitro and in matched scar and healthy bladder wall tissue samples of 12 patients with vesico-urethral anastomotic stricture (VUAS). RESULTS: Thirteen genes and 9 miRNAs showed differential expression in #WNT2B cells. Among these were TNFSF10, a key apoptosis inductor, (0.22fold, p = 0.011) and miR-1246 (36.2fold, p = 0.031). miRNA target prediction indicated TNFSF10 to be regulated by miR-1246. qRT-PCR analysis confirmed differential expression of miR-1246 and TNFSF10 in #WNT2B BWFs. Furthermore, TNFSF10 was significantly underexpressed in VUAS tissue (p = 0.009). CONCLUSION: Perturbation of WNT signalling results in an altered expression of the apoptosis inductor TNFSF10. Similar changes are observed in VUAS. Further studies investigating the crosslink between WNT signalling and apoptosis regulation in the urinary tract stroma are warranted.

Novel insights into a reputably irreversible process: combined mRNA and miRNA profiling of tissue from vesicourethral anastomotic stenosis after radical prostatectomy.

PURPOSE: Until recently, tissue fibrosis-ultimately leading to permanent scaring-has been considered an irreversible process. However, recent findings indicate that it may be reversible after all. Vesicourethral anastomotic stenosis (VUAS) as fibrous narrowing is a frequent complication after radical prostatectomy with high recurrence rates and requires invasive treatment. The pathophysiology is poorly understood. Therefore, a combined mRNA and miRNA transcription profiling in tissue from VUAS was performed using nCounter technology. METHODS: To assess tissue morphology and fiber composition, histochemical staining was performed. RNA expression of healthy and fibrotic tissue of twelve patients was analyzed using the human miRNA panel v3 and mRNA PanCancer pathway panel on the nCounter gene1 system and qRT-PCR. Differential expression data analysis was performed using the nSolver software implementing the R-based advanced pathway analysis tool. miRWalk2.0 was used for miRNA target prediction. RESULTS: More linearized tissue architecture, increased collagens, and decreased elastic fibers were observed in VUAS samples. 23 miRNAs and 118 protein coding genes were differentially expressed (p < 0.01) in fibrotic tissue. miRNA target prediction and overlap analysis indicated an interaction of the strongest deregulated miRNAs with 29 deregulated mRNAs. Pathway analysis revealed alterations in DNA repair, cell cycle regulation, and TGF-beta signaling. qRT-PCR confirmed differential expression of top deregulated miRNAs and mRNAs. CONCLUSIONS: In VUAS tissue, severe alterations on mRNA and miRNA level are found. These consistent changes give insights into the pathogenesis of VUAS after radical prostatectomy and point to future options for transcriptomics-based risk stratification and targeted therapies.

The effect of rapamycin on TGFß1 and MMP1 expression in a rabbit model of urethral stricture.

PURPOSE: To investigate the effect of rapamycin on TGFß1 and MMP1 expression in a rabbit model of urethral stricture. METHODS: Twenty-four adult New Zealand male rabbits underwent an electrocoagulation of the bulbar urethra with a 13Fr pediatric resectoscope. Then rabbits were randomly divided into three groups: (1) normal control group: normal saline (NS), (2) the vehicle control group: dimethyl sulfoxide (DMSO), and (3) the treatment group: effective-dose rapamycin in DMSO (Ra), with 12, 6, and 6 rabbits in each group, respectively. Drugs were given by urethral irrigation daily for 4 weeks. Urethral tissue was harvested for histological and molecular analyses. TGFß1 and MMP1 expression levels were evaluated by real-time quantitative PCR and immunohistochemistry. RESULTS: Ten, six, and six rabbits were evaluated finally in Ra, DMSO, and NS group, respectively. Histological examination revealed the distribution of fibrosis and the degree of collagen deposition in the Ra group were smaller and slighter than the two control groups. Collagen content was significantly less in the Ra group than in the DMSO group (P < 0.001) and the NS group (P < 0.001). qRT-PCR analysis showed a higher expression of MMP1 mRNA in the Ra group than in the DMSO group (P < 0.001) and the NS group (P < 0.001). Immunohistochemistry showed the protein levels of MMP1 in the Ra group were significantly increased when compared with the DMSO group (P < 0.01) and the NS group (P < 0.01). On the other hand, no statistical difference could be found between every two groups in both mRNA and protein levels of TGFß1. CONCLUSIONS: Rapamycin enhances the expression of MMP1 in a rabbit model of urethral stricture, but has no direct effect on the expression of TGFß1.

Rare copy number variants implicated in posterior urethral valves.

The cause of posterior urethral valves (PUV) is unknown, but genetic factors are suspected given their familial occurrence. We examined cases of isolated PUV to identify novel copy number variants (CNVs). We identified 56 cases of isolated PUV from all live-births in New York State (1998-2005). Samples were genotyped using Illumina HumanOmni2.5 microarrays. Autosomal and sex-linked CNVs were identified using PennCNV and cnvPartition software. CNVs were prioritized for follow-up if they were absent from in-house controls, contained ≥ 10 consecutive probes, were ≥ 20 Kb in size, had ≤ 20% overlap with variants detected in other birth defect phenotypes screened in our lab, and were rare in population reference controls. We identified 47 rare candidate PUV-associated CNVs in 32 cases; one case had a 3.9 Mb deletion encompassing BMP7. Mutations in BMP7 have been associated with severe anomalies in the mouse urethra. Other interesting CNVs, each detected in a single PUV case included: a deletion of PIK3R3 and TSPAN1, duplication/triplication in FGF12, duplication of FAT1--a gene essential for normal growth and development, a large deletion (>2 Mb) on chromosome 17q that involves TBX2 and TBX4, and large duplications (>1 Mb) on chromosomes 3q and 6q. Our finding of previously unreported novel CNVs in PUV suggests that genetic factors may play a larger role than previously understood. Our data show a potential role of CNVs in up to 57% of cases examined. Investigation of genes in these CNVs may provide further insights into genetic variants that contribute to PUV.

Crosstalk between TGF-ß1 and CXCR3 signaling during urethral fibrosis.

Urethral fibrosis is an important pathological feature of urethral stricture. TGF-ß1 and CXC chemokine receptor 3 (CXCR3) signaling have been reported as the critical pathways involved in the pathology of fibrosis. Here, we collected the urine samples from the patients with recurring urethral stricture, recurring stricture treated by cystostomy, and age- and gender-matched healthy people. ELISA detection revealed that TGF-ß1 level was significantly up-regulated for the urethral stricture patients. By contrast, flow cytometry, real-time PCR detection, and immunofluoresecent staining showed that urethral stricture resulted in decreased expression of CXCR3. TGF-ß1 treatment could increase cell proliferation and migration ability of urethra fibroblasts, whereas IP-10/CXCR3 signaling showed the opposite effect. Further, we found a crosstalk between TGF-ß1 and CXCR3 signaling in the regulation of urethral fibrosis. Thus, pharmacological intervention of TGF-ß1 or CXCR3 signaling has a potential as the therapeutic target for the prevention of urethral fibrosis.

Familial bulbar urethral strictures.

Strictures are commonly encountered in the urological practice. The most common aetiologies are infection, trauma and iatrogenic events. Familial occurrence of urethral stricture is exceptionally rare. We present a case in which bulbar urethral strictures developed in a father and his two sons.

Familial recurrence of urethral stenosis/atresia.

BACKGROUND: We report the familial recurrence of urethral stenosis/atresia in two sibling fetuses with bladder outlet obstruction, severe oligohydramnios, and pulmonary hypoplasia. Urethral obstruction in the fetus, when severe, results in a dilated urinary bladder (megacystis) and associated urinary anomalies (hydroureter, hydronephrosis, renal dysplasia). Distention of the fetal abdomen, the result of megacystis or urinary ascites, leads to stretching and eventually hypoplasia or even absence of abdominal muscles. CASES: This constellation of findings, known by a variety of terms including "prune belly" syndrome, is associated with a variety of urethral changes, including posterior urethral valves and urethral stenosis/atresia. One fetus manifested unilateral postaxial polydactyly of the left hand. CONCLUSIONS: A microdeletion of 6p25.3, identified in mother and one fetus, is not associated with a gene known to be involved in urethral development and therefore of unknown significance.

[Leiomyoma of the urethra - cause of an obstruction misdiagnosed as hereditary urethral stricture in a young man]. / Leiomyom der Urethra - Ursache einer als angeborene Harnröhrenenge fehlgedeuteten Striktur beim jungen Mann.

Leiomyomas are benign neoplasms arising from smooth muscle cells. We describe the case of a 17-year-old boy admitted with progressive severe obstructive voiding symptoms. Retrograde urethrography showed a bulbous urethral stricture which was resected with primary urethral anastomosis. Histopathological examination confirmed the very rare case of a leiomyoma of the urethra. In patients with urethral stricture, leiomyoma should be included in the diagnostic considerations.

Twenty-one-year-old male with congenital anomalies, obstructive uropathy and chronic renal failure: is this a case of Townes Brocks syndrome?

Townes Brocks syndrome is an autosomal dominant multiple malformations syndrome comprising of ear anomalies/hearing loss, limb defects, anal, genitourinary, eye, spine anomalies, heart defects and sometimes mental retardation. This report presents the case of a 21-year-old secondary school leaver as a likely case of Townes-Brocks syndrome. He was born with congenital abnormalities consisting of fixed flexion deformities of hands, wrist and elbows, urethral meatal stenosis, scoliosis and aortic stenosis. He was diagnosed with obstructive uropathy at the age of 19 years and subsequently developed chronic renal failure. The report aims to highlight the need for early recognition of potentially preventable conditions, which, if left unattended to, can lead to unnecessary fatality.

Immunohistochemical and molecular analysis in recurrent urethral stricture.

The authors have analyzed the most recent additions to the literature of immunohistochemical and molecular assessment of acquired urethral strictures and report on their data obtained in a selected clinical series. Innovative immunohistochemical studies in patients presenting with plurirecurrent symptoms suggest that urethral mesenchymal changes caused by tissue de-epithelialization may be the underlying cause of stricture. This condition may be congenital or acquired. It may determine aberrant connective tissue formation induced by abnormal fibroblastic activation with formation of over abundant hyperdense collagen scar tissue.

Apparent congenital anterior urethral stricture in brothers.

Anterior urethral strictures of apparent congenital origin are reported in brothers and the literature is reviewed.