Bladder Fibrosis Research Articles

Think Tank 2: How Do We Precisely Define the "High Risk Bladder" and What Are the Interrelationships Between Inflammation, Blood Flow, Fibrosis, and Loss of Bladder Compliance?

Defining "high-risk bladder" or "high-pressure bladder" involves recognizing the potential for an unsafe lower urinary tract, where dysfunction in storage and micturition can threaten upper urinary tract health, leading to unfavorable outcomes like dialysis, recurrent infections, systemic impact, or mortality. ICI-RS was held in Bristol in June 2024, and Think Tank 2 aimed to define research priorities including identifying clinical predictors and developing prevention and monitoring strategies. Risk factors encompass both congenital and neurogenic lower urinary tract dysfunction, bladder outlet obstruction, vascular diseases, and inflammatory disorders, but a validated stratification risk is lacking. Reduced compliance and detrusor overactivity lead to high filling pressures and raised detrusor leak point pressure, playing urodynamic studies a crucial role in risk assessment, though further research is needed for different neurogenic populations. Congenital conditions such as spina bifida, posterior urethral valves, and bladder exstrophy also contribute to a high-risk bladder through fibrosis and reduced compliance. Inflammation and ischemia are key factors, with inflammation leading to fibrosis and impaired bladder storage and voiding function. Novel treatments, including sGC activators, PDE5 inhibitors, and regenerative therapies like stem cell injections and extracorporeal shock wave treatment, show promise in mitigating fibrosis and improving bladder compliance. Identifying and validating clinical risk stratification models, precise biomarkers and therapeutic windows remains essential for effective management and reversal of bladder fibrosis and dysfunction.

The relationship between urodynamic bladder compliance and urinary fibrosis markers in children with neurogenic bladder dysfunction

BackgroundDecreased bladder compliance is an important risk factor for upper urinary tract in children with neurogenic bladder dysfunction (NBD). Urodynamics is the gold standard in determining bladder compliance. ObjectiveTo investigate the relationship between low bladder compliance and urinary fibrosis markers in NBD. Study designSpina bifida patients with NBD, who admitted between March 2021 and July 2021 were included. Patients with low compliant bladders, no renal scar, no recurrent urinary tract infections formed low compliance, LC group. Normal compliance, NC group, was comprised of patients with normocompliant bladders and the same characteristics. Control group (Group C) consisted of patients for outpatient surgery and had no known bladder dysfunction. Compliance was calculated with the formula ΔV/ΔP and a value of under 15 ml/cmH2O was accepted as low. Age, gender, urine density, serum urea, creatinine levels and urodynamic parameters were noted. Urinary type 1, type 3 collagen and its precursor procollagen type 3 and serum type 1 and 3 collagen were determined by ELISA. Results72 patients were included (LC group, n:31, NC group, n:24, C group n:17, mean age 7,39±1,24 years). No significant difference was observed in the comparison of age, gender, urine density and serum urea and creatinine values. No significant difference was observed between the LC and NC groups for urodynamic parameters, except for bladder compliance. Urinary collagen type 1 in LC group (11,71±3,02 ng/ml) was found to be significantly higher than that of the C group (9,45±1,97 ng/ml) (p=0,03). Urinary procollagen type 3 was significantly higher in LC group (103,15±24 ng/ml) when compared to C group (82,42±22,26 ng/ml) (p=0,016). Urinary collagen type 1 level above 9,20 ng/ml was 80,6% sensitive and 70,6% specific and urinary procollagen type 3 level above 78 ng/ml was 87% sensitive and 70,6% specific in predicting low compliance. DiscussionThis study seems to be the first study in the literature to evaluate bladder fibrosis and compliance, biochemically, by measuring urinary collagen levels in NBD. Urinary fibrosis markers are not currently an alternative to urodynamics for bladder compliance, but they may have potential to reduce the need for urodynamics with this indication. ConclusionDetermination of urinary collagen levels may be a marker of bladder wall fibrosis and may indirectly show decreased bladder compliance. It is plausible to say that invasive methods such as urodynamics may be less preferred for defining bladder compliance, instead, urinary biomarkers may have merit for this purpose in the future.

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.

A New Rat Model of Sacral Cord Injury Producing a Neurogenic Bladder and Its Functional and Mechanistic Studies.

Sacral spinal cord injury (SSCI) can disrupt bladder neuromodulation and impair detrusor function. Current studies provide limited information on the histologic and genetic changes associated with SSCI-related neurogenic lower urinary tract dysfunction (NLUTD), resulting in few treatment options. This study aimed to establish a simple animal model of SSCI to better understand the disease progression. Ninety 8-week-old Sprague-Dawley (SD) rats were randomly separated into sham operation and SSCI groups. The SSCI group underwent sacral spinal cord injury, while the sham group did not. Urodynamic and histological assessments were conducted at various intervals (1, 2, 3, 4, and 6 weeks) post-injury to elucidate the disease process. Urodynamic examinations revealed significant bladder dysfunction in the SSCI group compared to the sham group, stabilizing around 3-4 weeks post-injury. Histological examination, including hematoxylin-eosin and Masson's trichrome staining, correlated these functional changes with bladder microstructural alterations. RNA-seq was performed on bladder tissues from the sham group and SSCI group at 6 weeks to identify differentially expressed genes and pathways. Selected genes were further analyzed using polymerase chain reaction (PCR). The findings indicated a pronounced inflammatory response in the first 2 weeks post-SSCI, progressing to bladder fibrosis at 3-4 weeks. In conclusion, this study presents a reliable, reproducible, and straightforward SSCI model, providing insights into bladder functional and morphological alterations post-SSCI and laying the groundwork for future therapeutic research.

Preclinical Female Model of Urogenital Dysfunction and Pathophysiological Changes After Pelvic Radiation Therapy.

Introduction Radiation therapy (RT) is the gold standard for many pelvic cancers and improves overall patient survival. However, pelvic RT is associated with increased sexual dysfunction and urinary incontinence. Although the side effects of pelvic RT are well-documented, the pathological mechanisms leading to pelvic organ dysfunction are unknown, and a preclinical model has not been established. This study characterized the impact of pelvic RT at early and late timepoints on female rat bladder, vaginal, and urethral physiology and morphology. Methods Adult female Sprague-Dawley rats were divided into three groups (n = 8/group): (I) Sham, (II) four weeks RT (4wk RT), and (III) nine weeks RT (9wk RT). The RT groups received a single dose of 20 Gy external beam radiation, and experiments were conducted at 4wk and 9wk post-RT. Nerve-mediated vaginal blood flow was measured via laser Doppler. Tissue bath studies assessed vaginal contractility to electric field stimulation (EFS), adrenergic and cholinergic agonists, and relaxation to a nitric oxide donor. Bladder and urethral sphincters were evaluated for cholinergic, caffeine, and EFS-mediated contractility. Quantitative polymerase chain reaction (qPCR) measured gene expression of markers of oxidative stress. Vaginal, bladder, and urethral fibrosis were assessed with Masson's trichrome staining. Results At 4wk post-RT, total vaginal blood flow decreased, and at 9wk post-RT, returned to baseline levels. At 9wk post-RT, vaginal neurogenic and adrenergic-mediated contractile responses increased significantly. Vaginal epithelial thickness decreased post-RT and correlated with an acute rise in vaginal inflammatory gene expression. At 4wk post-RT, bladder neurogenic contractions decreased and remained lowered. Internal urethral contractions increased at 4wk post-RT and returned to Sham levels after 9wk post-RT. Pelvic RT increased external urethral neurogenic contractions, which remained elevated. Conclusion This novel preclinical model provides valuable insights into the temporal pathophysiology of pelvic RT-induced sexual and urinary dysfunction. The establishment of this model is crucial for understanding the underlying mechanisms involved in RT-induced pelvic injury. A reliable, clinically relevant model will allow for the testing of therapeutic strategies to prevent adverse effects with RT in pelvic cancer survivors.

Mechanosensitive Piezo1 channels promote neurogenic bladder fibrosis via regulating TGF-β1/smad and Hippo/YAP1 pathways

Bladder fibrosis is the final common pathway of neurogenic bladder (NB), and its underlying mechanisms are not fully understood. The current study aims to evaluate the involvement of Piezo1, a mechanosensitive channel, in bladder fibrosis. A full-thickness bladder specimen was taken during ileocystoplasty or ureteral reimplantation from the surgical cut's edge. By chopping off the bilateral lumbar 6 (L6) and sacral 1 (S1) spinal nerves, NB rat models were produced. Utilizing both pharmacological inhibition and Piezo1 deletion, the function of Piezo1 in the TGF-β1-induced fibrosis model of SV-HUC-1 cells was delineated. RNA-seq, immunofluorescence, immunohistochemistry (IHC), and Western blotting were used to evaluate the degrees of fibrosis and biochemical signaling pathways. Piezo1 protein expression was noticeably elevated in the human NB bladder. The abundance of Piezo1 protein in bladder of NB rats was significantly increased. RNA-seq analysis revealed that the ECM-receptor interaction signaling pathway and collagen-containing ECM were increased in spinal cord injury (SCI)-induced bladder fibrosis. Moreover, the bladder of the NB rat model showed activation of YAP1 and TGF-β1/Smad. In SV-HUC-1 cells, siRNA suppression of Piezo1 led to profibrotic responses and activation of the TGF-β1/Smad pathway. However, Yoda1, a Piezo1-specific agonist, significantly reduced these effects. TGF-β1 increased Piezo1 activation and profibrotic responses in SV-HUC-1 cells. In the TGF-β1-induced fibrosis model of SV-HUC-1 cells, the TGF-β1/Smad pathway was activated, whereas the Hippo/YAP1 signal pathway was blocked. Inhibition of Piezo1 further prevented this process. Piezo1 is involved in the progression of NB bladder fibrosis and profibrotic alterations in SV-HUC-1 cells, likely through regulating the TGF-β1/Smad and Hippo/YAP1 pathways.

High Hydrostatic Pressure Exacerbates Bladder Fibrosis through Activating Piezo1.

Bladder outlet obstruction (BOO) results in significant fibrosis in the chronic stage and elevated bladder pressure. Piezo1 is a type of mechanosensitive (MS) channel that directly responds to mechanical stimuli. To identify new targets for intervention in the treatment of BOO-induced fibrosis, this study investigated the impact of high hydrostatic pressure (HHP) on Piezo1 activity and the progression of bladder fibrosis. Immunofluorescence staining was conducted to assess the protein abundance of Piezo1 in fibroblasts from obstructed rat bladders. Bladder fibroblasts were cultured under normal atmospheric conditions (0 cmH2O) or exposed to HHP (50 cmH2O or 100 cmH2O). Agonists or inhibitors of Piezo1, YAP1, and ROCK1 were used to determine the underlying mechanism. The Piezo1 protein levels in fibroblasts from the obstructed bladder exhibited an elevation compared to the control group. HHP significantly promoted the expression of various pro-fibrotic factors and induced proliferation of fibroblasts. Additionally, the protein expression levels of Piezo1, YAP1, ROCK1 were elevated, and calcium influx was increased as the pressure increased. These effects were attenuated by the Piezo1 inhibitor Dooku1. The Piezo1 activator Yoda1 induced the expression of pro-fibrotic factors and the proliferation of fibroblasts, and elevated the protein levels of YAP1 and ROCK1 under normal atmospheric conditions in vitro. However, these effects could be partially inhibited by YAP1 or ROCK inhibitors. The study suggests that HHP may exacerbate bladder fibrosis through activating Piezo1.

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.

Pirfenidone improves voiding function by suppressing bladder fibrosis in underactive bladder rats

Underactive bladder (UAB), characterized by a complex set of symptoms with few treatment options, can significantly reduce the quality of life of affected people. UAB is characterized by hyperplasia and fibrosis of the bladder wall as well as decreased bladder compliance. Pirfenidone is a powerful anti-fibrotic agent that inhibits the progression of fibrosis in people with idiopathic pulmonary fibrosis. In the current study, we evaluated the efficacy of pirfenidone in the treatment of bladder fibrosis in a UAB rat model. UAB was induced by crushing damage to nerve bundles in the major pelvic ganglion. Forty-two days after surgery, 1 mL distilled water containing pirfenidone (100, 300, or 500 mg/kg) was orally administered once every 2 days for a total of 10 times for 20 days to the rats in the pirfenidone-treated groups.Crushing damage to the nerve bundles caused voiding dysfunction, resulting in increased bladder weight and the level of fibrous related factors in the bladder, leading to UAB symptoms. Pirfenidone treatment improved urinary function, increased bladder weight and suppressed the expression of fibrosis factors. The results of this experiment suggest that pirfenidone can be used to ameliorate difficult-to-treat urological conditions such as bladder fibrosis. Therefore, pirfenidone treatment can be considered an option to improve voiding function in patient with incurable UAB.

Insights into the epidemiology, pathogenesis, and differential diagnosis of schistosomiasis.

Schistosomiasis is a neglected tropical disease that is prevalent in low- and middle-income countries. There are five human pathogenic species, of which Schistosoma haematobium, Schistosoma mansoni and Schistosoma japonicum are the most prevalent worldwide and cause the greatest burden of disease in terms of mortality and morbidity. In addition, hybrid schistosomes have been identified through molecular analysis. Human infection occurs when cercariae, the larval form of the parasite, penetrate the skin of people while bathing in contaminated waters such as lakes and rivers. Schistosomiasis can cause both urogenital and intestinal symptoms. Urogenital symptoms include haematuria, bladder fibrosis, kidney damage, and an increased risk of bladder cancer. Intestinal symptoms may include abdominal pain, sometimes accompanied by diarrhoea and bloodin the stool. Schistosomiasis affects more than 250 million people and causes approximately 70 million Disability-Adjusted Life Years (DALYs), mainly in Africa, South America, and Asia. Tocontrol infection, it is essential to establish sensitive and specific diagnostic tests for epidemiological surveillance and morbidity reduction. This review provides an overview of schistosomiasis, with a focus on available diagnostic tools for Schistosoma spp. Current molecular detection methods and progress in the development of new diagnostics for schistosomiasis infection are also discussed.

Long non-coding RNA H19 mediates the miR-29b/transforming growth factor-β1/Drosophila mothers against decapentaplegic 3 signalling pathway to promote bladder fibrosis in diabetic rats.

Diabetic bladder fibrosis is a common comorbidity. Altered expression of some long non-coding RNAs (LncRNAs) has been associated with bladder fibrosis. LncRNA H19 has been reported to regulate bladder cancer through miR-29b. However, the action mechanism of LncRNA H19 in bladder fibrosis is unclear. In vitro, human bladder smooth muscle cells (HBSMCs) were cultured with transforming growth factor-β1 (TGF-β1) for 48h to construct cell model of bladder fibrosis. HBSMCs were then transfected with si-LncRNA H19, si-NC, miR-29b-mimic, mimic-NC, or miR-29b-inhibitor. In vivo, Sprague-Dawley (SD) rats were given a high-sucrose-high-fat (HSHF) diet for 4weeks and injected with streptozotocin (STZ, 50mg/kg) to induce bladder fibrosis model in diabetic rats, followed by injection of lentiviral particles knocking down LncRNA H19 expression, empty vector, or miR-29b-inhibitor, respectively. LncRNA H19 was up-regulated in TGF-β1-induced HBSMC fibrosis and STZ-induced diabetic rat bladder fibrosis, whereas miR-29b was down-regulated. si-LncRNA H19 reduced blood glucose levels and improved histopathological damage of bladder tissue in rats. In addition, si-LncRNA H19 or miR-29b-mimic increased the expression of E-cadherin, but decreased the expression of N-cadherin, vimentin, fibronectin (FN) in bladder tissues, and HBSMCs. si-LncRNA H19 reduced TGF-β1/p-drosophila mothers against decapentaplegic 3 (Smad3) protein in HBSMCs and in rat bladder tissues, while miR-29b-inhibitor reversed the effect of si-LncRNA H19. This study indicated that LncRNA H19 may inhibit bladder fibrosis in diabetic rats by targeting miR-29b via the TGF-β1/Smad3 signalling pathway.

Statement of Retraction: Circular RNA Plasmacytoma Variant Translocation 1 (CircPVT1) knockdown ameliorates hypoxia-induced bladder fibrosis by regulating the miR-203/Suppressor of Cytokine Signaling 3 (SOCS3) signaling axis

Statement of Retraction: Circular RNA Plasmacytoma Variant Translocation 1 (CircPVT1) knockdown ameliorates hypoxia-induced bladder fibrosis by regulating the miR-203/Suppressor of Cytokine Signaling 3 (SOCS3) signaling axis

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.

Melatonin serves as a novel treatment in bladder fibrosis through TGF-β1/Smad and EMT.

Melatonin (MEL) is an indole amine molecule primarily produced in the pineal gland. Melatonin has been shown in numerous studies to have antifibrotic effects on the kidney, liver, and other organs. However, it is still unclear how melatonin works in bladder fibrosis. We explored how melatonin affects animals with bladder fibrosis and the underlying mechanisms. MEL was used to treat human bladder smooth muscle cells (HBdSMCs) after they were stimulated with transforming growth factor-β1 (TGF-β1) in vitro. Proteomic analysis and bioinformatic analysis of the altered expression of these proteins were subsequently performed on HBdSMCs from the different processing methods. To construct an in vivo bladder fibrosis model, we injected protamine sulfate (PS) and lipopolysaccharide (LPS) twice a week into the rat bladder for six weeks. After two weeks of PS/LPS treatment, the mice in the treatment group were treated with MEL (20 mg/kg/d) for 4 weeks. Finally, we detected the expression of fibrosis markers from different perspectives. The TGF-β1/Smad pathway and epithelial-mesenchymal transition (EMT) in cell and bladder tissues were also identified. Further proteomic analysis was also performed. In vitro, we found that TGF-β1 treatment enhanced the expression of the fibrosis markers collagen III and α-SMA in HBdSMCs. E-cadherin expression decreased while the TGF-β1/Smad pathway was activated. Vimentin and N-cadherin expression was also elevated at the same time. Similar findings were observed in the LPS group. After MEL treatment, the expression of collagen III and α-SMA decreased, the expression of E-cadherin increased, and the expression of vimentin and N-cadherin also decreased. According to our quantitative proteomics analysis, CCN1 and SQLE may be important proteins involved in the development of bladder fibrosis. MEL decreased the expression of these genes, leading to the relief of bladder fibrosis. Bioinformatics analysis revealed that the extracellular space structure related to metabolic pathways, actin filament binding, and stress fibers can serve as a pivotal focus in the management of fibrosis. Melatonin attenuates bladder fibrosis by blocking the TGF-β1/Smad pathway and EMT. CCN1 appears to be a possible therapeutic target for bladder fibrosis.

Pattern of Expression of MicroRNA in Patients with Radiation-Induced Bladder Injury

Introduction: Bladder cancer (BC) is sensitive to radiation treatment and a subset of patients experience radiation-induced injuries including shrinkage of bladder due to bladder fibrosis. Methods: This study is a retrospective cohort study. Three Japanese BC patients were randomly selected. Using a microRNA (miRNA) array, comparing their samples with or without radiation-induced injuries, we have checked the clustering of miRNA expression. Results: Hsa-miR-130a, hsa-miR-200c, hsa-miR-141, and hsa-miR-96 were found to be highly expressed (>50 times) in patients with fibrotic bladder shrinkage (FBS) compared to those with intact bladder (IB) function. In patients with FBS, hsa-miR-6835, hsa-miR-4675, hsa-miR-371a, and hsa-miR-6885 were detected to have lesser than half expression to IB patients. We have analyzed the significance of these genes in relation to overall survival of 409 BC patients retrieved from the Cancer Genome Atlas data set. All available cutoff values between the lower and upper quartiles of expression are used for the selected genes, and false discovery rate using the Benjamini-Hochberg method is computed to correct for multiple hypothesis testing. We have run combined survival analysis of the mean expression of these four miRNAs highly expressed in FBS patients. 175 patients with high expression had a longer median survival of 98.47 months than 23.73 months in 233 patients with low expression (hazard ratio [HR]: 0.53; 0.39–0.72, log-rank p value: 7.3e−0.5). Combination analysis of all 8 genes including hsa-miR-6835, hsa-miR-4675, hsa-miR-371a, and hsa-miR-6885 showed the same HR for OS. Target scanning for these miRNAs matched specific cytokines known as an early biomarker to develop radiation-induced fibrosis. Conclusions: BC patients with fibrotic radiation injury have specific miRNA expression profile targeting profibrotic cytokines and these miRNAs possibly render to favorable survival.

Actomyosin Activity and Piezo1 Activity Synergistically Drive Urinary System Fibroblast Activation.

Mechanical cues play a crucial role in activating myofibroblasts from quiescent fibroblasts during fibrosis, and the stiffness of the extracellular matrix is of significant importance in this process. While intracellular force mediated by myosin II and calcium influx regulated by Piezo1 are the primary mechanisms by which cells sense and respond to mechanical forces, their intercellular mechanical interaction remains to be elucidated. Here, hydrogels with tunable substrate are used to systematically investigate the crosstalk of myosin II and Piezo1 in fibroblast to myofibroblast transition (FMT). The findings reveal that the two distinct signaling pathways are integrated to convert mechanical stiffness signals into biochemical signals during bladder-specific FMT. Moreover, it is demonstrated that the crosstalk between myosin II and Piezo1 sensing mechanisms synergistically establishes a sustained feed-forward loop that contributes to chromatin remodeling, induces the expression of downstream target genes, and ultimately exacerbates FMT, in which the intracellular force activates Piezo1 by PI3K/PIP3 pathway-mediated membrane tension and the Piezo1-regulated calcium influx enhances intracellular force by the classical FAK/RhoA/ROCK pathway. Finally, the multifunctional Piezo1 in the complex feedback circuit of FMT drives to further identify that targeting Piezo1 as a therapeutic option for ameliorating bladder fibrosis and dysfunction.

Inhibition of the NF-κB Signaling Pathway Alleviates Pyroptosis in Bladder Epithelial Cells and Neurogenic Bladder Fibrosis

Most children with a neurogenic bladder (NB) have bladder fibrosis, which causes irreversible bladder dysfunction and damage to the upper urinary tract. However, the mechanism of bladder fibrosis remains unclear. This study aimed to investigate the underlying causes of bladder fibrosis. Here, the lumbar 6 (L6) and sacral 1 (S1) spinal nerves of Sprague Dawley rats were severed bilaterally to establish NB models. Using RNA-seq, we discovered that the NF-κB signaling pathway and inflammation were upregulated in spinal cord injury (SCI)-induced bladder fibrosis. Subsequent Western blotting, enzyme-linked immunosorbent assays, immunohistochemical staining, and immunofluorescence staining verified the RNA-seq findings. To further clarify whether the NF-κB signaling pathway and pyroptosis were involved in bladder fibrosis, a TGF-β1-treated urinary epithelial cell line (SV-HUC-1 cells) was used as an in vitro model. Based on the results of RNA-seq, we consistently found that the NF-κB signaling pathway and pyroptosis might play important roles in TGF-β1-treated cells. Further experiments also confirmed the RNA-seq findings in vitro. Moreover, using the NLRP3 inhibitor MCC950 rescued TGF-β1-induced fibrosis, and the NF-κB signaling pathway inhibitor BAY 11-7082 effectively rescued TGF-β1-induced pyroptosis and the deposition of extracellular matrix by SV-HUC-1 cells. In summary, our research demonstrated for the first time that the NF-κB signaling pathway inhibition rescued bladder epithelial cells pyroptosis and fibrosis in neurogenic bladders.

Lack of expression of miR-29a/b1 impairs bladder function in male mice.

Lower urinary tract symptoms (LUTS) refer to various urological diseases, and incomplete bladder emptying is common among affected patients. Etiology of LUTS is largely unknown, and investigations of LUTS suggest that bladder fibrosis contributes to pathogenesis of LUTS. MicroRNAs (miRNAs) are short (∼22 nucleotides), non-coding RNAs that repress target gene expression by a combination of mRNA degradation and translation inhibition. The miR-29 family is best known for its anti-fibrotic role in various organs. miR-29 was decreased in bladders of patients with outlet obstruction and a rat model of bladder outlet obstruction, suggesting that miR-29 may contribute to impaired bladder function subsequent to tissue fibrosis. We characterized bladder function in male mice lacking expression of MIR29A and MIR29B1 (miR-29a/b1). Lack of miR-29a/b1 resulted in severe urinary retention, increased voiding duration with reduced flow rate, and these mice failed to void or voided irregularly during anesthetized cytometry. Collagens and elastin were increased in bladders of mice lacking miR-29a/b1. These findings reveal an important role of mir-29 in bladder homeostasis and suggest therapeutic potential of miR-29 to improve symptoms in patients with LUTS.

Activation of TRPA1 in Bladder Suburothelial Myofibroblasts Counteracts TGF-β1-Induced Fibrotic Changes.

The activation of the transient receptor potential ankyrin 1 (TRPA1) channel has anti-fibrotic effects in the lung and intestine. Suburothelial myofibroblasts (subu-MyoFBs), a specialized subset of fibroblasts in the bladder, are known to express TRPA1. However, the role of the TRPA1 in the development of bladder fibrosis remains elusive. In this study, we use the transforming growth factor-β1 (TGF-β1) to induce fibrotic changes in subu-MyoFBs and assess the consequences of TRPA1 activation utilizing RT-qPCR, western blotting, and immunocytochemistry. TGF-β1 stimulation increased α-SMA, collagen type I alpha 1 chain(col1A1), collagen type III (col III), and fibronectin expression, while simultaneously suppressing TRPA1 in cultured human subu-MyoFBs. The activation of TRPA1, with its specific agonist allylisothiocyanate (AITC), inhibited TGF-β1-induced fibrotic changes, and part of these inhibition effects could be reversed by the TRPA1 antagonist, HC030031, or by reducing TRPA1 expression via RNA interference. Furthermore, AITC reduced spinal cord injury-induced fibrotic bladder changes in a rat model. The increased expression of TGF-β1, α-SMA, col1A1 and col III, and fibronectin, and the downregulation of TRPA1, were also detected in the mucosa of fibrotic human bladders. These findings suggest that TRPA1 plays a pivotal role in bladder fibrosis, and the negative cross talk between TRPA1 and TGF-β1 signaling may represent one of the mechanisms underlying fibrotic bladder lesions.

ABT-263 exerts a protective effect on upper urinary tract damage by alleviating neurogenic bladder fibrosis

This study investigated the mechanism of action of ABT-263 in the treatment of neurogenic bladder fibrosis (NBF)and its protective effects against upper urinary tract damage (UUTD). Sixty 12-week-old Sprague-Dawley (SD) rats were randomly divided into sham, sham + ABT-263 (50 mg/kg), NBF, NBF + ABT-263 (25 mg/kg, oral gavage), and NBF + ABT-263 (50 mg/kg, oral gavage) groups. After cystometry, bladder and kidney tissue samples were collected for hematoxylin and eosin (HE), Masson, and Sirius red staining, and Western Blotting (WB) and qPCR detection. Primary rat bladder fibroblasts were isolated, extracted, and cultured. After co-stimulation with TGF-β1 (10 ng/mL) and ABT-263 (concentrations of 0, 0.1, 1, 10, and 100 µmol/L) for 24 h, cells were collected. Cell apoptosis was detected using CCK8, WB, immunofluorescence, and annexin/PI assays. Compared with the sham group, there was no significant difference in any physical parameters in the sham + ABT-263 (50 mg/kg) group. Compared with the NBF group, most of the markers involved in fibrosis were improved in the NBF + ABT-263 (25 mg/kg) and NBF + ABT-263 (50 mg/kg) groups, while the NBF + ABT-263 (50 mg/kg) group showed a significant improvement. When the concentration of ABT-263 was increased to 10 µmol/L, the apoptosis rate of primary bladder fibroblasts increased, and the expression of the anti-apoptotic protein BCL-xL began to decrease.ABT-263 plays an important role in relieving NBF and protecting against UUTD, which may be due to the promotion of myofibroblast apoptosis through the mitochondrial apoptosis pathway.