Overactive bladder (OAB) is a symptomatic disease that is difficult to treat. This study developed APTES-functionalized spiky titanium dioxide nanoparticles (ASNPs) loaded with botulinum toxin A (ASNP@BA), which is coated with P407/HA (HP) thermosensitive gel to treat OAB. Spiky nanoparticles exhibited a spiky nanostructure and were APTES-functionalized to exhibit enhanced drug-loading capacity. The optimal HP gel changed from liquid to gel near body temperature. In vitro, ASNPs enter cells via MYH9-mediated endocytosis. The expression of ZO-1 and E-cadherin proteins, along with changes in TEER, indicates that ASNPs entering cells do not compromise the integrity of the bladder barrier. In vivo, ASNP@HP showed excellent biocompatibility. Following bladder instillation of ASNP@HP, no significant toxicity was observed in major organs. The bladder barrier integrity was not significantly compromised. In a rat model, pretreatment of the bladder with ASNP@HPBA significantly reduced the excessive contraction induced by acetic acid, markedly reducing the intercontraction interval decline to 41.83% ± 17.78% compared to controls (∼75%) and free BTX-A (71.72%). The downregulation of SNAP-25 and SNAP-23 in the ASNP@HPBA group demonstrated successful targeted delivery and bioactivity. This platform combines macromolecular drug delivery with effective therapeutic efficacy and safety profile, representing a promising strategy for the treatment of OAB.

Post-stroke neurogenic bladder dysfunction impairs patients' quality of life, yet current treatments offer limited effectiveness. This study investigated the therapeutic effects and underlying mechanisms of human amniotic fluid stem cell-derived extracellular vesicle (hAFSC-EV) on bladder dysfunction and neurovascular plasticity after cerebral ischemia. Thirty-six female rats underwent bilateral ovariectomy and were assigned to sham-operated or 90-min middle cerebral artery occlusion (MCAO) groups, with or without a single injection of hAFSC-EVs. Magnetic resonance imaging (MRI), cystometry, blood-brain barrier (BBB) permeability, and markers of neurogenesis and angiogenesis in ischemic brain were assessed. Bladder levels of brain-derived neurotrophic factor (BDNF), β3-adrenoceptor, adenylate cyclase, and M2- and M3-muscarinic receptors were evaluated at 7 and 28days post-MCAO or sham-operation. Compared with untreated rats, hAFSC-EV treatment significantly reduced cerebral infarct volume and BBB leakage, and enhanced microvessel and vascular density, along with angiogenesis. Neural markers such as BDNF, nestin, and doublecortin were significantly upregulated at 7 and/or 28days post-MCAO. hAFSC-EV treatment ameliorated MCAO-induced bladder dysfunction by reducing peak voided volume, intercontraction interval, and bladder capacity, along with improving residual urine volume. hAFSC-EV treatment significantly increased bladder expression of BDNF and M3-muscarinic receptors, and recovers the expressions of M2, β3-adrenoceptor, and adenylate cyclase to near control levels at 7 and 28days post-MCAO. hAFSC-EV treatment improves neurogenic bladder dysfunction and cerebral ischemia post-MCAO, potentially through reducing infarct volume and BBB disruption, enhancing neurogenesis and angiogenesis in the ischemic brain, and modulating the expression of bladder BDNF, β3-adrenoceptor, adenylate cyclase and muscarinic receptors.

In this study, we aimed to investigate the impact of vibegron, a β3-adrenergic receptor agonist, on lower urinary tract dysfunction in a diabetic rat model. Female rats were categorized into three groups: non-diabetic controls (N), streptozotocin-induced diabetic rats receiving vehicle (D), and diabetic rats treated with vibegron (DV). In the DV group, vibegron was administered orally at 30 mg/kg/day starting 7-8 weeks after diabetes induction. At 8 weeks post-induction, voiding assays, urinary 8-hydroxydeoxyguanosine (8-OHdG) measurements, cystometry, and analysis of bladder mRNA expression levels of ischemia- and inflammatory-related markers were performed. The 24-h voiding assays showed that Groups D and DV had markedly higher urine volume, average voided volume, voiding frequency, and water intake compared to Group N. Urinary 8-OHdG levels were markedly elevated in Group D than those in Groups N and DV. Group D also exhibited higher opening pressure and non-voiding contractions. Intercontraction intervals, voided volume, post-void residual volume, bladder capacity, and compliance were significantly increased, while voiding efficiency was markedly decreased in Groups D and DV compared to that in Group N. Bladder mRNA expression of hypoxia-inducible factor-1 alpha (Hif1a), vascular endothelial growth factor A (Vegfa), transforming growth factor-beta 1 (Tgfb1), and tumor necrosis factor alpha (Tnfa) was upregulated in Group D compared with that in Groups N and DV. These findings suggest that vibegron may be a promising therapeutic option for addressing detrusor overactivity, ischemia, and inflammation of the bladder associated with diabetes mellitus.

Adipose stem-cell-derived microvesicles ameliorate long-term bladder ischemia-induced bladder underactivity.

BACKGROUNDThe incidence of diabetic atherosclerosis (DMA) is increasing worldwide, but its pathogenesis remains incompletely understood. In addition to cardiovascular complications, bladder dysfunction is one of the common comorbidities associated with DMA but is often refractory to current treatments.AIMTo investigate the therapeutic effect of human amniotic fluid stem cell-derived extracellular vesicles (hAFSC-EVs) on the recovery of bladder dysfunction in DMA rats.METHODSEighty rats were divided into normal control, streptozotocin-induced diabetic rats, diabetic rats subjected to arterial balloon endothelial injury of common iliac artery (DMA), and DMA rats treated with hAFSC-EVs (DMA + hAFSC-EVs). At 4 weeks and 12 weeks after DMA induction, levels of blood glucose, total cholesterol, triglyceride, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, homeostasis model assessment (HOMA)-insulin resistance, and HOMA-β were measured. Cystometry, common iliac artery wall thickness, and bladder tumor necrosis factor (TNF)-α, interleukin (IL)-6, transforming growth factor (TGF)-β1, Smad3, connective tissue growth factor (CTGF) and fibronectin were also evaluated.RESULTSBladder weight and blood glucose, triglyceride, HOMA-insulin resistance, common iliac artery intima thickness, voided volume, intercontraction interval, bladder capacity, and mRNA expression of TNF-α, IL-6, TGF-β1, Smad3, CTGF and fibronectin were significantly increased at 4 weeks and 12 weeks after induction, while the HOMA-β level decreased at 4 weeks and 12 weeks, and the high-density lipoprotein cholesterol level decreased at 12 weeks. hAFSC-EVs treatment in DMA rats significantly reduced bladder weight and blood glucose, thickness of common iliac arterial intima, voided volume, intercontraction interval and bladder capacity at 4 weeks. The mRNA expression of TNF-α, TGF-β1, and CTGF in DMA rats treated with hAFSC-EVs were significantly decreased at 4 weeks, while the mRNA expressions of IL-6 and Smad3 were significantly decreased 12 weeks.CONCLUSIONhAFSC-EVs treatment can help restore DMA-induced bladder dysfunction, which is associated with lowered blood glucose levels, reduced arterial wall thickness, and decreased TNF-α, IL-6, TGF-β1, Smad3, and CTGF expression.

Activation of 5-HT2A receptor by TCB2 improves bladder function in rats with bilateral pelvic nerve injury via TRPV4.

Bladder outlet obstruction (BOO) leads to detrusor overactivity (DO) and structural remodeling of the bladder. However, the molecular mechanisms underlying this process remain incompletely understood. In a rat model of partial BOO, we assessed bladder function via cystometry and evaluated histological changes using hematoxylin and eosin staining. The expression and localization of aquaporin (AQP)-2 and caveolin (CAV)-1, -2, and -3 were analyzed by Western blotting and immunofluorescence in bladder tissues. Additionally, immunostaining was performed in cultured human bladder smooth muscle cells to assess protein co-localization. BOO rats exhibited elevated detrusor contraction pressure and shortened intercontraction intervals. Histologically, hypertrophied smooth muscle bundles and increased extracellular matrix were observed. Western blot analysis revealed significant upregulation of AQP2 and CAV1-3 in BOO bladders. Tissue immunofluorescence demonstrated increased expression and redistribution of these proteins in the detrusor muscle. Cultured cell analysis confirmed subcellular co-localization of AQP2 with CAV1-3. DO induced by BOO is associated with upregulated expression of AQP2 and CAV1-3 in the urinary bladder. The coexpression observed in bladder cells suggests potential molecular interactions between AQP2 and CAVs that may contribute to the pathophysiology of BOO-related bladder dysfunction.

The southern alligator lizard (Elgaria multicarinata) exhibits prolonged mate-holding behavior. This behavior maybe be underpinned by a phenomenon known as sustained force, observed in the jaw muscles of this species, in which the muscle fails to relax between subsequent contractions. However, it is not clear if sustained force is unique to the jaw muscles used in mate-holding, or what the mechanisms responsible for this phenomenon are. In situ and in vitro muscle preparations were used to determine peak force, sustained force, and relaxation rate in the jaw-adductor complex, the iliotibialis 2 (IT2), and the gastrocnemius muscles of E. multicarinata during repeated contractions to determine if sustained force is unique to the jaw. There was a significant effect of muscle on sustained force with only the jaw muscles exhibiting sustained force. To determine if sustained force was due to a slowing of relaxation or the engagement of a passive element such as the molecular spring titin, the inter-contraction interval was increased in the jaw-adductor complex to allow for greater relaxation time. There was a significant effect of inter-contraction interval on sustained force with sustained force being lost and the muscle fully relaxing and force returning to baseline between contractions with a longer inter-contraction interval. The uniqueness of sustained force to the jaw muscle provides support for it being an adaptation for mate-holding that may observed in multiple vertebrate groups. The loss of sustained force with increased inter-contraction interval implicates changes to relaxation process in the mechanism of the development of sustained force. This suggests that this is a fundamentally different mechanism from the catch mechanism used for prolonged maintenance of force in some invertebrates.

The lower urinary tract stores and periodically eliminates urine, which is regulated by the peripheral and central nervous system (CNS). Thromboxane A₂ (TxA2), an arachidonic acid metabolite known for platelet aggregation, is a neuromodulator exciting the glutamatergic nervous system, which is essential for the voiding function in the CNS. However, roles of brain TxA2 in regulating micturition reflex remain unclear. Therefore, we investigated the effects of (1) centrally administered TxA2 analogue U-46619 on the reflex, and (2) centrally pretreated TxA2 receptor (TP receptor) and glutamate receptor antagonists on analogue-induced responses in male rats. Under urethane anaesthesia, centrally administered U-46619 [10 nmol per rat, intracerebroventricularly (ICV)] significantly shortened intercontraction interval (ICI), the interval between two bladder voiding contractions. Additionally, U-46619 (10 nmol per rat, ICV) reduced the single-voided volume and bladder capacity without altering post-voided residual volume or voiding efficacy. However, the U-46619-induced ICI shortening was suppressed by pretreatment with S-18886 (TP receptor antagonist, 300 nmol per rat, ICV), or DNQX (α-amino-3-hydroxy-5-methyl-4-isoxazole propionate [AMPA] glutamate receptor antagonist, 3 nmol per rat, ICV). From these results, stimulation of brain TP receptors facilitates the micturition reflex through brain AMPA receptors. We propose a novel function of brain TxA2 in the micturition regulation.

To establish a reproducible male rat model exhibiting myogenic underactive bladder (UAB)-like features by applying bladder cryoinjury following direct saline instillation via fine-needle puncture, thereby providing a useful platform for studying UAB pathophysiology and treatment. Male Wistar rats underwent bladder cryoinjury using dry ice-cooled aluminum rods placed on the bladder wall after filling the bladder with saline through a 30G needle. Sham-operated rats received room-temperature rod application. Two weeks post-injury, continuous and single cystometry were performed to evaluate voiding pressure (VP), post-void residual volume (PVR), and voiding efficiency (VE). Bladder strips were examined in organ bath studies for carbachol-induced contractility. Hematoxylin and eosin staining was conducted for histological evaluation. Cryoinjured rats showed a significant increase in PVR and significant decreases in VP and VE compared to sham rats, indicating impaired voiding function consistent with UAB. No significant differences were observed in intercontraction interval or carbachol- or KCl-induced contractile responses in bladder strips between cryoinjured and sham rats. In bladder sections, cryoinjury induced acute inflammation with neutrophil infiltration and notable appearance of foamy macrophages, suggesting phagocytic activity. We established a practical and minimally invasive male rat model exhibiting myogenic UAB-like features 2 weeks after cryoinjury. While exvivo cholinergic and KCl-evoked contractility was largely preserved at this time point, invivo voiding remained impaired, suggesting contributions beyond muscle contractility. This model may facilitate mechanistic and therapeutic studies for UAB.

Potential role of brain nitric oxide in inhibiting α7 nicotinic acetylcholine receptor-mediated suppression of the micturition reflex in rats.

Optogenetics is a powerful technique for both investigating the mechanism underlying neurological disorders and modifying them using disease model animals. However, there is limited evidence demonstrating the potential of optogenetics in disease (lower urinary tractdysfunction; LUTD) model with targetingthe cerebral cortex.Here, we evaluated the effect of optogenetic stimulation of GABAergic neurons intheanterior cingulate cortex (ACC) on urodynamics in a urinary frequency mouse model. Channelrhodopsin-2 (ChR2) was selectively expressed in parvalbumin expressing neurons of the ACC in mice. For the induction of urinary frequency, 0.1% acetic acid was perfused into the bladder, while normal saline was used for control. Photostimulation was delivered to the ACC and intercontraction intervals (ICIs) were measured before, during and after photostimulation. Photostimulation prolonged ICI only during stimulation and ICI was recovered after stimulation in control condition. We found in the urinary frequency model that photostimulation also significantly prolonged ICI, which was recovered after stimulation. Cell-type selective photoactivation in the ACC can modulate urodynamics in disease model. The application of optogenetics for the treatment of LUTD have an advantage of temporal specificity, making it useful for controlling immediate urgency.

To investigate whether low-intensity energy shock wave therapy (LiESWT) applied to the bladder can alleviate maternal separation (MS)-induced lower urinary tract dysfunction and anxiety-like behavior in a rat model. Sprague-Dawley rat pups were divided into normal, MS, and MS + LiESWT groups. MS was performed on postnatal days 2-14. At 6weeks of age, the MS + LiESWT group received shock wave therapy (0.12mJ/mm2, 2Hz, 200 shocks per session, nine sessions) in the bladder region. At 9weeks of age, all groups underwent anxiety-like behavior assessment using the elevated plus maze test, followed by metabolic cage evaluation, cystometry, and histology to assess bladder function and morphology. Compared to normal rats, MS rats exhibited increased bladder weight, shortened intercontraction intervals, and increased anxiety-like behavior. LiESWT treatment normalized bladder weight and improved urinary frequency compared to MS rats, and reduced anxiety-like behavior, as evidenced by recovery of time spent in the open arms of the elevated plus maze. Sex-related differences were observed, with effects being more pronounced in females. This was particularly evident in the voiding frequency during the dark phase and the adrenal gland weight. LiESWT applied to the bladder improved bladder dysfunction and reduced anxiety-like behavior in MS rats, suggesting potential interactions between bladder function and emotional state that may involve shared neural circuits. The findings indicated the potential therapeutic applications of LiESWT for improving the stress-induced dysfunction affecting the integrated neurobiological pathways that govern both bladder control and behavioral regulation.

The pathogenesis of interstitial cystitis/bladder pain syndrome (IC/BPS) remains unclear, and there is no definitive treatment for this condition. Studies have shown that antisense oligonucleotide (asODN) targeting nerve growth factor (NGF) can downregulate the level of NGF in the bladder, however, the uptake of NGF asODN by the body is limited. Therefore, this study constructed cationic liposomes (CLs) as a delivery system to carry NGF asODN and evaluated its functional efficacy on the bladder. The results indicated that the optimized CLs/asODN delivery system had an average particle size of approximately 200 nm, an average zeta potential of around +53 mV, and an encapsulation efficiency of over 90% with good stability. Additionally, CLs/asODN significantly facilitated the uptake of asODN fluorescence by the urothelium, with an uptake rate of 14.6%, which was 40.2 times free asODN. In a rat model of IC/BPS, treatment with CLs/asODN reduced voiding frequency, significantly increased maximum cystometric capacity, prolonged inter-contraction interval of the bladder, and improved bladder compliance. Furthermore, hematoxylin-eosin staining and immunohistochemical analysis revealed significantly reduced expression levels of NGF, PACAP, Piezo2, CCL2, IL-6, and TGF-β factors after treatment, indicating that the overexpression of NGF in the bladder could be indirectly blocked by complexing NGF asODN with cationic liposomes. The CLs/asODN prepared in this study improved the adhesion and penetration of the drug at the bladder mucosa site, effectively alleviated bladder dysfunction in rats, and further enhanced the inhibitory effect of asODN on NGF, which may provide a new strategy for the treatment of IC/BPS.

Escitalopram can reverse co-occurring depression and overactive bladder induced by corticosterone in rats.

Prostaglandin E2 (PGE2) facilitates the micturition reflex at the lower urinary tract and spinal cord levels. However, the roles of brain PGE2 in reflex regulation remain unclear. Therefore, we aimed to investigate the effects of intracerebroventricularly administered PGE2 on the micturition reflex. We further investigated whether the PGE2-induced responses were dependent on the sympathetic nervous system (SNS) and identified the brain E-prostanoid receptor subtypes (EP1-EP4) involved in PGE2-induced effects. Intracerebroventricularly administered PGE2 (0.1, 0.3, or 1 nmol/rat) dose-dependently increased the intercontraction intervals (ICI) and threshold pressure required to induce micturition (TP) without altering maximal voiding pressure in urethane-anesthetized (0.8g/kg, ip) male rats. PGE2 (1 nmol/rat) significantly increased the mean blood pressure; 6-hydroxydopamine-induced chemical sympathectomy ameliorated this increase. In contrast, chemical sympathectomy had no significant effect on the PGE2-induced increases in ICI and TP. Intracerebroventricularly pretreated SC51322 (EP1 receptor antagonist, 100 nmol/rat) and PF04418948 (EP2 receptor antagonist, 100 nmol/rat), but not L-798106 (EP3 receptor antagonist, 100 nmol/rat) or L-161982 (EP4 receptor antagonist, 100 nmol/rat), significantly attenuated the PGE2 (1 nmol/rat)-induced changes in ICI and TP. These results suggest that centrally administered PGE2 suppresses the rat micturition reflex through brain EP1 and EP2 receptors, independent of SNS activation.

Ultra-High Frequency Spinal Nerve Neuromodulation for Improving Bladder Continence: Implications for Overactive Bladder Management

Sacral Magnetic Neuromodulation with Intermittent Theta Burst Waveform Enhances Overactive Bladder: In Vivo Study

Bacillus coagulans TCI803 confers gastroesophageal protection against Helicobacter pylori-evoked gastric oxidative stress and acid-induced lower esophageal sphincter inflammation

To investigate the effectiveness of acotiamide on lower urinary tract dysfunction by using a rat model of neurogenic underactive bladder induced through pelvic nerve crush (PNC) injury. Bilateral PNC injuries were performed on 8-week-old female Sprague-Dawley rats (PNC group); the sham surgery group was used as control (control group). Two weeks after surgery, awake cystometrography (CMG) was performed, and acotiamide (10 or 100 mg/kg) was subcutaneously administered to the control and PNC groups. Subsequently, CMG parameter values obtained before and after treatment were compared. In baseline CMG, compared to control group, PNC group revealed statistically significant elevations in the intercontraction intervals (ICIs), number of nonvoiding contractions, baseline pressure, threshold pressure, bladder capacity, voided volumes, and postvoid residual. However, contraction amplitudes and voiding efficiency were significantly decreased. In the control group, compared with the baseline values, 10-mg/kg acotiamide resulted in statistically significant elevations in contraction amplitudes. Treatment with 100-mg/kg acotiamide led to statistically significant elevations in contraction amplitudes and decreases in ICI and bladder volume. In the PNC group, there were no statistically significant changes noted in CMG parameters after treatment with 10-mg/kg acotiamide (n=6). Compared with the baseline values, the administration of 100-mg/kg acotiamide significantly decreased ICI (1,025±186 seconds vs. 578±161 seconds; P=0.012), bladder capacity (1,841±323 µL vs. 871±174 µL, respectively; P=0.0059) and postvoid residual (223±46 µL vs. 44±22 µL, respectively; P=0.023), and increased contraction amplitudes (22.09±1.76 cm H2O vs. 43.84±6.87 cm H2O, respectively; P=0.012) and voiding efficiency (0.87±0.02 vs. 0.94±0.03, respectively; P=0.029). Acotiamide showed effectiveness in the treatment of underactive bladder, possibly through activation of bladder afferent and detrusor activities.