Rho kinase inhibition ameliorates cyclophosphamide-induced cystitis in rats

Aberrant activation of TGF-β/ROCK1 enhances stemness during prostatic stromal hyperplasia

Benign prostatic hyperplasia (BPH) is a multifactorial disease in which abnormal growth factor activation and embryonic reawakening are considered important factors. Here we demonstrated that the aberrant activation of transforming growth factor β (TGF-β)/Rho kinase 1 (ROCK1) increased the stemness of BPH tissue by recruiting mesenchymal stem cells (MSCs), indicating the important role of embryonic reawakening in BPH. When TGF-β/ROCK1 is abnormally activated, MSCs are recruited and differentiate into fibroblasts/myofibroblasts, leading to prostate stromal hyperplasia. Further research showed that inhibition of ROCK1 activation suppressed MSC migration and their potential for stromal differentiation. Collectively, our findings suggest that abnormal activation of TGF-β/ROCK1 regulates stem cell lineage specificity, and the small molecule inhibitor GSK269962A could target ROCK1 and may be a potential treatment for BPH.

The Assessment of the Efficacy of Imperatorin in Reducing Overactive Bladder Symptoms

Overactive bladder syndrome (OAB) is a prevalent condition that affects the elderly population in particular and significantly impairs quality of life. Imperatorin, a naturally occurring furocoumarin, possesses diverse pharmacological properties that warrant consideration for drug development. The aim of this study was to investigate the potential of imperatorin (IMP) to attenuate the cystometric and biochemical changes typically associated with retinyl acetate-induced overactive bladder (OAB) and to assess its viability as a pharmacological intervention for OAB patients. A total of 60 rats were divided into four groups: I-control, II-rats with rapamycin (RA)-induced OAB, III-rats administered IMP at a dose of 10 mg/kg/day, and IV-rats with RA-induced OAB treated with IMP. IMP or vehicle were injected intraperitoneally for 14 days. The cystometry and assessment of bladder blood flow were performed two days after the last dose of IMP. The rats were then placed in metabolic cages for 24 h. Urothelial thickness measurements and biochemical analyses were performed. Intravesical infusion of RA induced OAB. Notably, intraperitoneal administration of imperatorin had no discernible effect on urinary bladder function and micturition cycles in normal rats. IMP attenuated the severity of RA-induced OAB. RA induced increases in urothelial ATP, calcitonin gene-related peptide (CGRP), organic cation transporter 3 (OCT3), and vesicular acetylcholine transporter (VAChT), as well as significant c-Fos expression in all micturition areas analyzed, which were attenuated by IMP. Furthermore, elevated levels of Rho kinase (ROCK1) and VAChT were observed in the detrusor, which were reversed by IMP in the context of RA-induced OAB in the urothelium, detrusor muscle, and urine. Imperatorin has a mitigating effect on detrusor overactivity. The mechanisms of action of IMP in the bladder appear to be diverse and complex. These findings suggest that IMP may provide protection against RA-induced OAB and could potentially develop into an innovative therapeutic strategy for the treatment of OAB.

Uro-protective role of chrysin against cyclophosphamide-induced hemorrhagic cystitis in rats involving the turning-off NF-κB/P38-MAPK, NO/PARP-1 and STAT-3 signaling cascades

BACKGROUND

Chemotherapeutic agents are used to treat a wide range of cancer types, but they cause serious side effects which must be managed after treatment. Cyclophosphamide (CYP) is one of chemotherapeutic drugs that causes hemorrhagic cystitis (HC) induced by acrolein.

OBJECTIVE

The current investigation intended to uncover the role of chrysin (CHR) in CYP-induced HC in rats and explore the signaling pathway beyond this effect.

ANALYSIS

process: A single dose of CYP (200 mg/kg/IP) was injected, meanwhile CHR (25, 50 and 100 mg/kg, P.O) was administered respectively for 7 days prior to CYP administration and resume for 7 days afterwards. Urinary bladder tissue was then isolated from all rats to assess oxidative stress and inflammatory biomarkers. Moreover, histopathological examinations were performed.

RESULTS

Treatment with CHR showed a marked alleviation in oxidative stress biomarkers induced by CYP. Furthermore, CHR treatment presented a dose-dependent boost in the anti-inflammatory; IL-10 levels and a drop in the pro-inflammatory biomarkers; IL-1β, IL-6, and TNF-α. Additionally, stabilization of the PARP-1 protein expression was also detected thus preventing DNA damage. Similarly, CHR restored the urinary bladder cGMP levels. Notably, CHR treatment was accompanied with inhibition in NF-κB/p38-MAPK, NO/PARP-1 and STAT-3 signaling pathways inflammatory cascades. All these findings conformed with the histopathological examinations as well as iNOS immunostaining in the urinary bladder tissue.

CONCLUSION

Co-administration of CHR and CYP attained uro-protective therapeutic potential to guard against HC as well as spot the tangled mechanism of CHR in attenuating the HC induced by CYP.

Sulfhydryl functionalized hyaluronic acid hydrogels attenuate cyclophosphamide-induced bladder injury

Clinical management of cyclophosphamide (CYP) results in numerous side effects including hemorrhagic cystitis (HC), which is characterized by inflammation and oxidative stress damage. Intravesical hyaluronic acid (HA) supplementation, a therapeutic method to restore barrier function of bladder, avoid the stimulation of metabolic toxicants on bladder and reduce inflammatory response, has shown good results in acute or chronic bladder diseases. However, there are unmet medical needs for the treatment of HC to temporarily restore bladder barrier and reduce inflammation. Herein, sulfhydryl functionalized HA (HA-SH) and dimethyl sulfoxide (DMSO) were used to prepared a hydrogel system for optimizing the treatment of HC. We systematically evaluated the physicochemical of hydrogels and their roles in a rat model of CYP-induced HC. The prepared hydrogels exhibited outstanding gel forming properties, injectability, and biosafety. Swelling and retention studies showed that hydrogels were stable and could prolong the residence time of HA in the bladder. Histopathology and vascular permeability studies indicated that the hydrogels significantly attenuated bladder injury caused by CYP administration. Moreover, the hydrogels also showed excellent anti-inflammation and anti-oxidation properties. In conclusion, these data suggest that intravesical instillation of HA-SH/DMSO hydrogels reduces CYP-induced bladder toxicity and this work provides a new strategy for the prevention and early treatment of HC.

The Uroprotective Efficacy of Total Ginsenosides in Chinese Ginseng on Chemotherapy with Cyclophosphamide

Hemorrhagic cystitis is a recognizable complication of cyclophosphamide (CYP) attributable to its lively metabolite acrolein, which produces urothelial injury. The study intended to examine the uroprotective efficacy of total ginsenosides in Chinese ginseng (TGCG) in CYP-induced hemorrhagic cystitis. In total, 24 virgin female rats were randomized into four groups as follows: group 1 (control group; injected with normal saline), group 2 (injected with CYP plus a placebo with normal saline), group 3 (given CYP and TGCG (200 mg/kg)), and group 4 (given CYP and 2-mercaptoethane sulfonate sodium (Mesna, 30 mg/kg)). An evaluation by cystometry was conducted. Values of the voiding interval were assessed in anesthetized rats and histological examinations of the bladders were measured. In the cystometry analysis, the voiding interval was significantly reduced in the CYP group. TGCG and Mesna significantly increased in the voiding interval values, individually. Bladder edema and urothelial injury were examined after contact with CYP. Contrasted to the group given CYP, CYP-induced hemorrhagic cystitis, TGCG significantly increased the urothelial thickness, and significantly reduced scores of mucosal break and submucosal edema in the bladder. In conclusion, these findings mean that the treatment with TGCG in CYP rats can avoid hemorrhagic cystitis. TGCG decreases urothelial injury. TGCG may participate as the chief character of uroprotection in CYP-induced hemorrhagic cystitis.

Protective effects of hydrogen sulfide pretreatment on cyclophosphamide-induced bladder dysfunction in rats via suppression of bladder afferent nerves

Cyclophosphamide (CYP), a broad-spectrum anticancer drug, causes serious side effects, such as haemorrhagic cystitis (HC). Hydrogen sulfide (H₂S), an endogenous gasotransmitter, has physiological properties, including anti-inflammation, anti-oxidation, and neuromodulation. In this study, we investigated the effects of NaHS (H₂S donor) pretreatment on bladder dysfunction in CYP-treated rats. Male Wistar rats were intraperitoneally pretreated with NaHS (3 or 10 μmol/kg) or vehicle once daily for 7 days before cystometry, and CYP (150 mg/kg) or saline was intraperitoneally administered 2 days before cystometry. After cystometry, the bladder tissues were collected for haematoxylin and eosin staining. In some rats, capsaicin (CAP), which can desensitise CAP-sensitive afferent nerves, was subcutaneously injected at 125 mg/kg 4 days before cystometry. CYP reduced intercontraction intervals (ICI) and bladder compliance (Comp) and increased the number of non-voiding contractions (NVCs) compared with the saline-treated control group. NaHS pretreatment dose-dependently improved the CYP-induced these changes. In bladder tissues, CYP increased histological scores of neutrophil infiltration, haemorrhage, and oedema, while NaHS had no effect on these CYP-induced changes. CAP showed a tendency to suppress CYP-induced changes in ICI. NaHS-induced improvement in CYP-induced changes in urodynamic parameters were not detected in CAP-treated rats. These findings suggest that NaHS pretreatment prevented bladder dysfunction in CYP-treated rats by suppressing CAP-sensitive bladder afferent nerves, but not by suppressing bladder inflammation. Therefore, H₂S represents a new candidate as a protective drug for bladder dysfunction induced by HC, a side effect of CYP chemotherapy.

Potentilla chinensis aqueous extract attenuates cyclophosphamide-induced hemorrhagic cystitis in rat model

Cyclophosphamide (CYP) damages all mucosal defence lines and induces hemorrhagic cystitis (HC) leading to detrusor overactivity. Patients who undergo combined chemio-radiotherapy are at higher risk of HC. Potentilla chinensis extract (PCE) prevent oxidative stress-dependent diseases. Thus, the aim of the study was to investigate the effect of PCE on urinary bladder function in CYP-induced HC in preclinical study. 60 rats were divided into 4 groups, as follows: I—control, II—rats with CYP-induced HC, III—rats received PCE in dose of 500 mg/kg, and IV—rats with CYP-induced HC which received PCE in dose of 500 mg/kg. PCE or vehicle were administered orally for 14 days. The cystometry was performed 3 days after the last dose of the PCE. Next, urothelium thickness and oedema measurement and biochemical analyses were performed. Cyclophosphamide induced hemorrhagic cystitis. PCE had no influence on the urinary bladder function and micturition cycles in normal rats. PCE diminished the severity of CYP-induced hemorrhagic cystitis. In the urothelium the cyclophosphamide induced the elevation of CGRP, TNF-α, IL-6, IL-1β, OTC_3, NIT, and MAL. Also, the level of T-H protein, HB-EGF, and ZO1 was decreased. Moreover, the level of ROCK1 and VAChT in detrusor muscle increased. cyclophosphamide caused an increased concentration of BDNF and NGF in the urine. In turn, PCE in cyclophosphamide-induced hemorrhagic cystitis caused a reversal of the described biochemical changes within urothelium, detrusor muscle and urine. PCE attenuates detrusor overactivity. In conclusion, our results revealed that PCE attenuates detrusor overactivity in case of cyclophosphamide-induced hemorrhagic cystitis. The potential properties of PCE appear to be important in terms of preventing of oxidative stress-dependent dysfunction of urinary bladder. PCE may become a potential supportive treatment in patient to whom cyclophosphamide-based chemotherapy is used.

5-Aminolevulinic acid has the potential to prevent bladder dysfunction in cyclophosphamide-induced hemorrhagic cystitis

OBJECTIVES

To investigate the effects of pretreatment with 5-aminolevulinic acid hydrochloride combined with sodium ferrous citrate on bladder dysfunction in cyclophosphamide-induced hemorrhagic cystitis in rats.

METHODS

Male Wistar rats (340-460 g) were pretreated with vehicle or with 5-aminolevulinic acid hydrochloride combined with sodium ferrous citrate (100/157 or 300/471 mg/kg/day, po) once daily for 7 days before cystometry. Saline or cyclophosphamide (150 mg/kg, ip) was administered 2 days before cystometry. Cystometry was performed under urethane anesthesia (0.8 g/kg, ip) via a catheter inserted into the bladder. After cystometry, bladder tissues were collected to perform hematoxylin and eosin staining for pathological evaluation (neutrophil infiltration, edema, and bleeding scores), and for enzyme-linked immunosorbent assay and real-time polymerase chain reaction for investigating tissue levels of myeloperoxidase, and mRNA levels of haem oxygenase-1 as a cytoprotective molecule.

RESULTS

Compared to controls, cyclophosphamide induced a shorter intercontraction interval, lower bladder compliance, increased number of non-voiding contractions, and increased pathological scores and myeloperoxidase expression in the bladder. Pretreatment with 5-aminolevulinic acid hydrochloride combined with sodium ferrous citrate (300/471 mg/kg/day) significantly improved cyclophosphamide-induced intercontraction interval shortening and increases in number of non-voiding contractions and neutrophil infiltration/bleeding scores and enhanced haem oxygenase-1 expression in the bladder. In addition, cyclophosphamide-induced decreases in bladder compliance and increases in myeloperoxidase were not detected with 5-aminolevulinic acid hydrochloride combined with sodium ferrous citrate pretreatment.

CONCLUSIONS

Pretreatment with 5-aminolevulinic acid expects protective effects on bladder dysfunction in cyclophosphamide-induced hemorrhagic cystitis by improving inflammatory changes in bladder tissues perhaps via up-regulation of haem oxygenase-1.

Silencing ROCK1 ameliorates ventilator-induced lung injury in mice by inhibiting macrophages' NLRP3 signaling

Rho kinase, including two subtypes, ROCK1 and ROCK2, controls a variety of biological processes helping coordinate the tissues response to stress and injury. Some authors believe that alveolar macrophages (AMs) play a key role in the early phase of ventilator-induced lung injury (VILI), which is closely related to the activation of NLRP3 inflammasome and NF-κB signaling. However, there is currently little known about the relationship between ROCK signaling and NLRP3 inflammasome. Accordingly, we focused on exploring the effect of ROCK for NLRP3 inflammasome, the results showed that VILI in C57BL/6 mice significantly increased NF-κB, NLRP3, ASC, caspase1 expression, and the secretion of cytokines, which was reversed by applying the ROCK Inhibitor-Y27632. Moreover, the use of AMs and mechanical stretching suggested that ROCK regulated transcriptional level of NF-κB and NLRP3 inflammasome in AMs. Specifically, we silenced the ROCK1 and ROCK2 respectively, and found that the inflammation of MH-S cells after LPS and ATP priming could be regulated by ROCK1 and ROCK2, while the NLRP3 was only dependent upon ROCK1. Meantime, the related genes of NLRP3 signal are also regulated by ROCK1. Collectively, our data suggest that silencing ROCK1 ameliorates VILI in mice in part by inhibiting AMs' NLRP3 signaling pathway.

The Potential of Asiatic Acid in the Reversion of Cyclophosphamide-Induced Hemorrhagic Cystitis in Rats

The purpose of this study was to determine if asiatic acid may act efficiently in the model of cyclophosphamide (CYP)-induced cystitis in rats. We performed experiments after administration of CYP (single dose 200 mg/kg, intraperitoneally), asiatic acid (30 mg/kg/day for 14 consecutive days, by oral gavage), or CYP plus asiatic acid, during which conscious cystometry, measurements of urothelium thickness and bladder edema, as well as selected biomarkers analyses were conducted. In rats that received asiatic acid together with CYP, a drop in bladder basal pressure, detrusor overactivity index, non-voiding contraction amplitude, non-voiding contraction frequency, and the area under the pressure curve were observed, when compared to the CYP group. Furthermore, a significant increase in threshold pressure, voided volume, intercontraction interval, bladder compliance, and volume threshold to elicit NVC were found in that group accordingly. Administration of the asiatic acid successfully restored concentrations of biomarkers both in bladder urothelium (BDNF, CGRP, OCT-3, IL-1β, IL-6, NGF, nitrotyrosine, malondialdehyde, TNF-α, SV2A, SNAP23, SNAP25, PAC-1, ORM1, occludin, IGFBP-3, HB-EGF, T–H protein, Z01, and HPX) and detrusor muscle (Rho kinase and VAChT) in CYP-treated rats. Finally, asiatic acid significantly decreased urothelium thickness and bladder oedema. Asiatic acid proved to be a potent and effective drug in the rat model of CYP-induced cystitis.

Double benefit of metformin treatment: improved bladder function in cyclophosphamide-induced cystitis and enhanced cytotoxicity in cancer cells

Cyclophosphamide (CP) is a widely used anti-neoplastic drug; however, it leads to bladder dysfunction in the form of hemorrhagic cystitis that is a serious dose-limiting complication in cancer patients. We aimed to evaluate the protective effects of metformin (MET) in a mouse model of CP-related cystitis in parallel with its effect on CP-induced cytotoxicity in a breast cancer cell line, MDA-MB-231. Cystitis was induced by a single intraperitoneal injection of CP (300 mg/kg), and mice were administered MET, mesna, or vehicle treatment. 24 hours after cystitis induction, the bladders were removed for histopathological analysis and ex vivo evaluation of detrusor muscle contractility. The effect of MET on the cytotoxicity of CP in MDA-MB-231 cells was evaluated as the viability of the cells via MTT assay. Histopathological evaluation confirmed that CP induced a severe cystitis, and MET partially inhibited CP-induced bladder damage. Carbachol-evoked cholinergic contractions were significantly decreased in detrusor strips of mice injected with CP only compared to control (E_max=293.67± 20.00 vs. 497.79± 21.78 mg tension/mg tissue, respectively). In CP-injected mice, treatment with 100 mg/kg MET restored cholinergic contractions (E_max=473.72±62.61 mg tension/mg tissue). In MDA-MB-231 cells, MET decreased their viability, and the combination of MET and CP caused more decrease in cell viability as compared to CP alone (p<0.05), demonstrating that MET enhances the cytotoxicity of CP in these cancer cells. Our results indicate that MET has a strong potential as a therapeutic adjuvant to prevent CP-induced cystitis while enhancing the efficacy of CP.

Asiatic Acid, a Natural Compound that Exerts Beneficial Effects on the Cystometric and Biochemical Parameters in the Retinyl Acetate-Induced Model of Detrusor Overactivity

Scientists have been constantly looking for new synthetic and natural compounds that could have beneficial effects in bladder overactivity. Our attention was drawn by asiatic acid that influences a number of molecules and signaling pathways relevant for the proper functioning of the urinary tracts in humans. In the present project we wanted to check whether asiatic acid would have positive effects in the confirmed animal model of detrusor overactivity (DO) and whether it would affect the bladder blood flow, urothelium thickness, inflammatory and oxidative stress markers, neurotrophic and growth factors, and other parameters important for the activity of the urinary bladder. The outcomes of our study showed that a 14-day administration of asiatic acid (30 mg/kg/day) by oral gavage normalizes the cystometric parameters corresponding to DO and reduces the accompanying oxidative stress (measured by the levels of malondialdehyde–61,344 ± 24,908 pg/ml vs. 33,668 ± 5,071 pg/ml, 3-nitrotyrosine–64,615 ± 25,433 pg/ml vs. 6,563 ± 1,736 pg/ml, and NOS2–2,506 ± 411.7 vs. 3,824 ± 470.1 pg/ml). Moreover, it decreases the urinary secretion of neurotrophins (BDNF–304.4 ± 33.21 pg/ml vs. 119.3 ± 11.49 pg/ml and NGF–205.5 ± 18.50 vs. 109.7 ± 15.94 pg/ml) and prevents the changes in a range of biomarkers indicating the dysfunction of the urinary bladder, CGRP (421.1 ± 56.64 vs. 108.1 ± 11.73 pg/ml), E-Cadherin (773.5 ± 177.5 pg/ml vs. 1,560 ± 154.5 pg/ml), OCT3 (3,943 ± 814.6 vs. 1,018 ± 97.07 pg/ml), SNAP-23 (6,763 ± 808.9 pg/ml vs. 3,455 ± 554.5 pg/ml), SNAP-25 (2,038 ± 162.7 pg/ml vs. 833.3 ± 65.48), substance P (171.7 ± 16.86 pg/ml vs. 65.07 ± 8.250 pg/ml), SV2A (1,927 ± 175.3 pg/ml vs. 1,154 ± 254.9 pg/ml), tight junction protein 1 (360.1 ± 95.05 pg/ml vs. 563.4 ± 65.43 pg/ml), VAChT (16,470 ± 2,419 pg/ml vs. 7,072 ± 1,339 pg/ml), VEGFA (318.3 ± 37.89 pg/ml vs. 201.5 ± 22.91 pg/ml). The mentioned parameters are associated with smooth muscle contractions, urothelial barrier, transportation and release of transmitters, or bladder compensation. Thus, the presented findings allow to suggest a possible future role of asiatic acid in the prevention of conditions accompanied by DO, such as overactive bladder.

The influence of Potentilla chinensis aqueous extract on urinary bladder function in retinyl acetate-induced detrusor overactivity in rats

INTRODUCTION & OBJECTIVES

In overactive bladder (OAB) therapy several herbal medicines presented promising effects, however the results are sparse to provide their efficacy. Herbals may become a popular alternative for OAB therapy. Therefore, we investigated whether Potentilla chinensis extract (PCE) would reverse retinyl acetate (RA)-induced detrusor overactivity (DO).

MATERIAL & METHODS

60 rats were divided into 4 groups, as follows: I - control, II - rats with RA-induced DO, III - rats received PCE in dose of 500 mg/kg, and IV - rats with RA-induced DO which received PCE. PCE or vehicle were administered orally for 14 days. The cystometry and bladder blood flow assessment were performed 3 days after the last dose of the PCE. Then the rats were put into the metabolic cages for 24 h. Next, urothelium thickness measurement and biochemical analyses were performed. < /p><p> Results. Intravesical infusion of RA solution induced DO. PCE had no influence on the urinary bladder function and&nbsp; micturition cycles in normal rats. PCE diminished the severity of RA-induced DO. In the urothelium the RA induced the elevation of ATP, CGRP, substance P, VEGF-A, OTC3, and ERK1/2. The concentration of NOS2, CDH1, and ZO1 decreased. Moreover, RA affected the concentration of SNARE proteins (increased concentration of SNAP23, SNAP25, and SV2A). Also in detrusor the elevated level of ROCK1 and VAChT were observed. In turn, PCE in RA-induced DO caused a reversal of the described biochemical changes within urothelium, detrusor muscle and urine. < /p><p> Conclusions. PCE attenuates detrusor overactivity. The potential mechanisms of action of PCE in the urinary bladder seem to be multifactorial and complex. PCE seems to become a reasonable novel OAB therapy.

Tropisetron ameliorates cyclophosphamide-induced hemorrhagic cystitis in rats

Hemorrhagic cystitis is one of the most important complications of cyclophosphamide, a drug widely used in cancer chemotherapy and bone marrow transplantation. 5-HT₃ antagonists are anti-emetic agents and have been shown to have notable anti-inflammatory and antioxidant properties. This study was designed to investigate the possible protective effects of tropisetron against cyclophosphamide-induced hemorrhagic cystitis in rats. Hemorrhagic cystitis was induced in female rats by cyclophosphamide (270 mg/kg). Tropisetron (2.5, 5 and 7.5 mg/kg), granisetron (2.5 and 5 mg/kg), and ondansetron (5 mg/kg) were injected 15 min before, 4 and 8 h after cyclophosphamide. To evaluate the role of alpha7 nicotinic acetylcholine receptor (α7nAChR), its antagonist, methyllycaconitine (5 mg/kg) was administered 30 min before tropisetron. After 24 h, animals were killed under anesthesia. Macroscopic and histological changes were evaluated. Malondialdehyde (MDA), glutathione (GSH) and Evans blue were measured spectrophotometrically. Furthermore, the protein levels of p38 mitogen-activated protein kinases (P38 MAPK), p-P38, signal transducer and activator of transcription 3 (STAT3), p-STAT3 and Poly (ADP-ribose) polymerase (PARP) were determined using Western blot. Cyclophosphamide administration significantly induced histopathological damages and increased MDA, p-p38/p38, p-STAT3/STAT3, and PARP levels compared with the saline group. Tropisetron treatment diminished histopathological injuries as well as MDA level, and STAT3 activity compared to cyclophosphamide treated rats. Co-administration of methyllycaconitine with tropisetron, partially or completely reversed the protective effects of tropisetron. Our results showed that prophylactic administration of tropisetron markedly ameliorated the cyclophosphamide-induced bladder hemorrhage and inflammation in rats. These effects of tropisetron were α7nAChR dependent.

The effect of O-1602, a GPR55 agonist, on the cyclophosphamide-induced rat hemorrhagic cystitis

The goal of our study was to determine whether GPR55 agonists, O-1602, could reverse the cyclophosphamide (CYP)-induced changes in cystometric and inflammatory parameters, indicative of the development of bladder inflammation and overactivity. If confirmed, the stimulation of novel cannabinoid receptor - GPR55, could be a reasonable strategy as a treatment of CYP-induced haemorrhagic cystitis. The experiments were conducted in female Wistar rats. Based on the methodology of our published studies on CYP-induced heamorrhagic cystitis we performed experiments after administration of CYP, O-1602 or CYP plus O-1602. These included surgical procedures, conscious cystometry, measurements of bladder oedema and urothelium thickness using the Evans Blue dye leakage technique, as well as biochemical analyses with particular ELISA kits. O-1602 ameliorated the symptoms of CYP-induced detrusor overactivity leading to an increase in voided volume (0.59 vs. 0.93 ml), and lowering the detrusor overactivity index (703 vs. 115 cm H2O/ml). Intravenous administration of the GPR55 agonist to animals that received CYP significantly decreased Evans Blue extravasation and increased urothelium thickness. O-1602 also reversed the pro-inflammatory activity of CYP by restoring concentrations of brain-derived neurotrophic factor, nerve growth factor, calcitonin gene related peptide, interleukin 1-beta, interleukin-6, tumour necrosis factor alpha, malondialdehyde, nitrotyrosine, occludin, and organic cation transporter 3. GPR55 agonist, O-1602, represents a novel class of uroprotective agents, targeting the inflammatory basis of cystitis. To our knowledge, this is the first paper proposing O-1602 agent, as a candidate for future studies in the treatment of CYP-induced cystitis.

A Novel Alternative in the Treatment of Detrusor Overactivity? In Vivo Activity of O-1602, the Newly Synthesized Agonist of GPR55 and GPR18 Cannabinoid Receptors

The aim of the research was to assess the impact of O-1602—novel GPR55 and GPR18 agonist—in the rat model of detrusor overactivity (DO). Additionally, its effect on the level of specific biomarkers was examined. To stimulate DO, 0.75% retinyl acetate (RA) was administered to female rats’ bladders. O-1602, at a single dose of 0.25 mg/kg, was injected intra-arterially during conscious cystometry. Furthermore, heart rate, blood pressure, and urine production were monitored for 24 h, and the impact of O-1602 on the levels of specific biomarkers was evaluated. An exposure of the urothelium to RA changed cystometric parameters and enhanced the biomarker levels. O-1602 did not affect any of the examined cystometric parameters or levels of biomarkers in control rats. However, the O-1602 injection into animals with RA-induced DO ameliorated the symptoms of DO and caused a reversal in the described changes in the concentration of CGRP, OCT₃, BDNF, and NGF to the levels observed in the control, while the values of ERK1/2 and VAChT were significantly lowered compared with the RA-induced DO group, but were still statistically higher than in the control. O-1602 can improve DO, and may serve as a promising novel substance for the pharmacotherapy of bladder diseases.

NO-Releasing Nanoparticles Ameliorate Detrusor Overactivity in Transgenic Sickle Cell Mice via Restored NO/ROCK Signaling

Sickle cell disease (SCD) is associated with overactive bladder (OAB). Detrusor overactivity, a component of OAB, is present in an SCD mouse, but the molecular mechanisms for this condition are not well-defined. We hypothesize that nitric oxide (NO)/ ras homolog gene family (Rho) A/Rho-associated kinase (ROCK) dysregulation is a mechanism for detrusor overactivity and that NO-releasing nanoparticles (NO-nps), a novel NO delivery system, may serve to treat this condition. Male adult SCD transgenic, combined endothelial NO synthases (eNOSs) and neuronal NOS (nNOS) gene-deficient (dNOS^-/-), and wild-type (WT) mice were used. Empty nanoparticle or NO-np was injected into the bladder, followed by cystometric studies. The expression levels of phosphorylated eNOS (Ser-1177), protein kinase B (Akt) (Ser-473), nNOS (Ser-1412), and myosin phosphatase target subunit 1 (MYPT1) (Thr-696) were assessed in the bladder. SCD and dNOS^-/- mice had a greater (P < 0.05) number of voiding and nonvoiding contractions compared with WT mice, and they were normalized by NO-np treatment. eNOS (Ser-1177) and AKT (Ser-473) phosphorylation were decreased (P < 0.05) in the bladder of SCD compared with WT mice and reversed by NO-np. Phosphorylated MYPT1, a marker of the RhoA/ROCK pathway, was increased (P < 0.05) in the bladder of SCD mice compared with WT and reversed by NO-np. nNOS phosphorylation on positive (Ser-1412) regulatory site was decreased (P < 0.05) in the bladder of SCD mice compared with WT and was not affected by NO-np. NO-nps did not affect any of the measured parameters in WT mice. In conclusion, dysregulation of NO and RhoA/ROCK pathways is associated with detrusor overactivity in SCD mice; NO-np reverses these molecular derangements in the bladder and decreases detrusor overactivity. SIGNIFICANCE STATEMENT: Voiding abnormalities commonly affect patients with sickle cell disease (SCD) but are problematic to treat. Clarification of the science for this condition in an animal model of SCD may lead to improved interventions for it. Our findings suggest that novel topical delivery of a vasorelaxant agent nitric oxide into the bladder of these mice corrects overactive bladder by improving deranged bladder physiology regulatory signaling.

Functional effects of blocking VEGF/VEGFR2 signaling in the rat urinary bladder in acute and chronic CYP-induced cystitis

High expression of VEGF is associated with immature angiogenesis within the urinary bladder wall and bladder afferent nerve sensitization, leading to visceral hyperalgesia and pelvic pain. Research suggests a shift in VEGF alternative splice variant (VEGF-A_xxxa and VEGF-A_xxxb) expression with several pathologies (e.g., neuropathic pain and inflammation) as well as differing effects on pain. Translational studies have also demonstrated increased total VEGF expression in the bladders of women with interstitial cystitis/bladder pain syndrome. In the present study, we quantified VEGF alternative splice variant expression in lower urinary tract tissues under control conditions and with cyclophosphamide (CYP)-induced cystitis. Using conscious cystometry and intravesical instillation of a potent and selective VEGF receptor 2 (VEGFR2) tyrosine kinase inhibitor (Ki-8751, 1 mg/kg) in Wistar rats (male and female) with acute and chronic CYP-induced cystitis and control (no CYP) rats, we further determined the functional effects of VEGFR2 blockade on bladder function. With VEGFR2 blockade, bladder capacity increased (P ≤ 0.01) in male and female control rats as well as in male and female rats with acute (P ≤ 0.05) or chronic (P ≤ 0.01 or P ≤ 0.05, respectively) CYP-induced cystitis. Void volume also increased in female control rats (P ≤ 0.01) and female rats with acute (P ≤ 0.05) or chronic (P ≤ 0.05) CYP-induced cystitis as well as in male control rats (P ≤ 0.05) and male rats with chronic CYP-induced cystitis (P ≤ 0.01). These data suggest that VEGF may be a biomarker for interstitial cystitis/bladder pain syndrome and that targeting VEGF/VEGFR2 signaling may be an effective treatment.

Blebbistatin reveals beneficial effects on the cystometric parameters in an animal model of detrusor overactivity

The aims of the study were to determine the effectiveness of blebbistatin (BLEB) on detrusor overactivity (DO) in an animal model induced by retinyl acetate (RA) and, because of potential urothelial permeability, to evaluate the degenerative impact of BLEB on the urothelium. Three days after RA instillation into the urinary bladder, BLEB was administered into the bladder and immediately after cystometric assessment was performed. Furthermore, Evans Blue extravasation into bladder tissue and urothelium thickness were measured. Sixty female Wistar rats were used and randomly assigned to one of four groups (n = 15 in each group): (1) control, (2) RA, (3) BLEB, and (4) RA + BLEB. RA administration induced changes in cystometric parameters reflecting DO, as previously reported. Treatment with BLEB did not significantly alter cystometric parameters in rats which did not receive RA. Administration of BLEB to rats pretreated with RA reversed changes in cystometric parameters induced by RA in basal pressure, threshold pressure, detrusor overactivity index, amplitude of nonvoiding contractions, frequency of nonvoiding contractions, voided volume, volume threshold, intercontraction interval, bladder compliance, and volume threshold to elicit nonvoiding contractions. There were no significant differences in Evans Blue extravasation into bladder tissue or urothelium thickness between the groups. The current research provides new data on the possible utility of blebbistatin in the pharmacotherapy of DO, which is an important feature of overactive bladder (OAB). Further studies in human patients with DO/OAB are warranted to confirm these preclinical results.

Downregulation of tight junction protein zonula occludens-2 and urothelium damage in a cyclophosphamide-induced mouse model of cystitis

OBJECTIVES

The cyclophosphamide (CYP)-induced model of cystitis in mice closely fits the symptoms of chronic bladder inflammation. Cystitis was recently found to be due to an altered gap junction protein in a rat model. Thus, this study was conducted to evaluate changes in protein expression and composition in the bladder of CYP-treated mice.

MATERIALS AND METHODS

Administration of CYP induced cystitis-related symptoms in mice. Cystometry was assessed and cell junction-associated protein zonula occludens-2 (ZO-2) expression was measured. Voiding interval values (time between voids) were assessed in mice under anesthesia. The bladders were removed for proteomic analysis using label-free quantitative proteomics and liquid chromatography-mass spectrometry. Additionally, immunochemistry (IHC) and Western blot were used to confirm the location and level, respectively, of ZO-2 expression.

RESULTS

Compared to the control group, the voiding interval values and urothelial thickness in the bladder in the CYP-treated group were significantly decreased. Additionally, we identified 105 differentially expressed proteins in the bladder of CYP-treated mice with proteomic analysis. These proteins were involved in cell-cell tight junctions, exocytosis, muscle development, contraction, and regulation, immune responses, proteolysis, and cell adhesion. IHC and Western blot confirmed the downregulation of the tight junction protein ZO-2 in the urothelium of bladder.

CONCLUSIONS

Our results suggest that downregulation in tight junction protein ZO-2 and urothelium damage may have a role in cystitis-related OAB. These changes could be related to the molecular mechanism of cystitis-related OAB.