Therapeutic effects of inhibition of brain-derived neurotrophic factor on voiding dysfunction in mice with spinal cord injury

Effects of low-intensity extracorporeal shock wave on bladder and urethral dysfunction in spinal cord injured rats

PURPOSE

To investigate the effects of low-intensity extracorporeal shock wave therapy (LiESWT) on bladder and urethral dysfunction with detrusor overactivity and detrusor sphincter dyssynergia (DSD) resulting from spinal cord injury (SCI).

METHODS

At 3 weeks after Th9 spinal cord transection, LiESWT was performed on the bladder and urethra of adult female Sprague Dawley rats with 300 shots of 2 Hz and an energy flux density of 0.12 mJ/mm2, repeated four times every 3 days, totaling 1200 shots. Six weeks postoperatively, a single cystometrogram (CMG) and an external urethral sphincter electromyogram (EUS-EMG) were simultaneously recorded in awake animals, followed by histological evaluation.

RESULTS

Voiding efficiency significantly improved in the LiESWT group (71.2%) compared to that in the control group (51.8%). The reduced EUS activity ratio during voiding (duration of reduced EUS activity during voiding/EUS contraction duration with voiding + duration of reduced EUS activity during voiding) was significantly higher in the LiESWT group (66.9%) compared to the control group (46.3%). Immunohistochemical examination revealed that fibrosis in the urethral muscle layer was reduced, and S-100 stained-positive area, a Schwann cell marker, was significantly increased in the urethra of the LiESWT group.

CONCLUSION

LiESWT targeting the urethra after SCI can restore the EUS-EMG tonic activity during voiding, thereby partially ameliorating DSD. Therefore, LiESWT is a promising approach for treating bladder and urethral dysfunction following SCI.

Pathology and physiology of acid-sensitive ion channels in the bladder

Acid-sensitive ion channels (ASICs) are sodium-permeable channels activated by extracellular acidification. They can be activated and trigger the inward flow of Na+ when the extracellular environment is acidic, leading to membrane depolarization and thus inducing action potentials in neurons. There are four ASIC genes in mammals (ASIC1-4). ASIC is widely expressed in humans. It is closely associated with pain, neurological disorders, multiple sclerosis, epilepsy, migraines, and many other disorders. Bladder pain syndrome/interstitial cystitis (BPS/IC) is a specific syndrome characterized by bladder pain. Recent studies have shown that ASICs are closely associated with the development of BPS/IC. A study revealed that ASIC levels are significantly elevated in a BPS/IC model. Additionally, researchers have reported differential changes in ASICs in the bladders of patients with neurogenic lower urinary tract dysfunction (NLUTD) caused by spinal cord injury (SCI). In this review, we summarize the structure and physiological functions of ASICs and focus on the mechanisms by which ASICs mediate bladder disease.

Sex differences in lower urinary tract function in mice with or without spinal cord injury

OBJECTIVES

We examined sex differences of lower urinary tract function and molecular mechanisms in mice with and without spinal cord injury (SCI).

METHODS

SCI was induced by Th8-9 spinal cord transection in male and female mice. We evaluated cystometrograms (CMG) and electromyography (EMG) of external urethral sphincter (EUS) at 6 weeks after SCI in spinal intact (SI) and SCI mice. The mRNA levels of Piezo2 and TRPV1 were measured in L6-S1 dorsal root ganglia (DRG). Protein levels of nerve growth factor (NGF) in the bladder mucosa was evaluated using an enzyme-linked immunosorbent assay.

RESULTS

Sex differences were found in the EUS behavior during voiding as voiding events in female mice with or without SCI occurred during EUS relaxation periods without EUS bursting activity whereas male mice with or without SCI urinated during EUS bursting activity in EMG recordings. In both sexes, SCI decreased voiding efficiency along with increased tonic EUS activities evident as reduced EUS relaxation time in females and longer active periods of EUS bursting activity in males. mRNA levels of Piezo2 and TRPV1 of DRG in male and female SCI mice were significantly upregulated compared with SI mice. NGF in the bladder mucosa showed a significant increase in male and female SCI mice compared with SI mice. However, there were no significant differences in Piezo2 or TRPV1 levels in DRG or NGF protein levels in the bladder mucosa between male and female SCI mice.

CONCLUSIONS

We demonstrated that female and male mice voided during EUS relaxation and EUS bursting activity, respectively. Also, upregulation of TRPV1 and Piezo2 in L6-S1 DRG and NGF in the bladder could be involved in SCI-induced lower urinary tract dysfunction in both sexes of mice.

Targeting neurotrophin and nitric oxide signaling to promote recovery and ameliorate neurogenic bladder dysfunction following spinal cord injury - Mechanistic concepts and clinical implications

This review summarizes the presentations made to a workshop entitled "Targeting Neurotrophin and Nitric Oxide Signaling to Promote Recovery and Ameliorate Neurogenic Bladder Dysfunction following Spinal Cord Injury - Mechanistic Concepts and Clinical Implications" at the International Continence Society (ICS) 2022 Vienna Meeting. Spinal cord injury (SCI; T8-T9 contusion/transection) causes impaired mobility, neurogenic detrusor overactivity (NDO), detrusor sphincter dyssynergia (DSD) and subsequent decreased quality of life. This workshop discussed the potential of future therapeutic agents that manage the lesion and its consequences, in particular possibilities to reduce the lesion itself and manage pathophysiological changes to the lower urinary tract (LUT). Attenuation of the spinal cord lesion itself was discussed with respect to the potential of a trio of agents: LM11A-3, a p75 neurotrophin receptor modulator to counter activation of local apoptotic pathways; LM22B-10 to promote neuronal growth by targeting tropomyosin-related kinase (Trk) receptors; and cinaciguat, a soluble guanylate cyclase (sGC) activator as an agent promoting angiogenesis at the injury site. The workshop also discussed targets on the bladder to block selectivity sites associated with detrusor overactivity and poor urinary filling profiles, such as purinergic pathways controlling excess contractile activity and afferent signaling, as well as excess fibrosis. Finally, the importance of increased mechanosensitive signaling as a contributor to DSD was considered, as well as potential drug targets. Overall, an emphasis was placed on targets that help restore function and reduce pathological LUT consequences, rather than downregulate normal function.

Assessing Neurogenic Lower Urinary Tract Dysfunction after Spinal Cord Injury: Animal Models in Preclinical Neuro-Urology Research

Neurogenic bladder dysfunction is a condition that affects both bladder storage and voiding function and remains one of the leading causes of morbidity after spinal cord injury (SCI). The vast majority of individuals with severe SCI develop neurogenic lower urinary tract dysfunction (NLUTD), with symptoms ranging from neurogenic detrusor overactivity, detrusor sphincter dyssynergia, or sphincter underactivity depending on the location and extent of the spinal lesion. Animal models are critical to our fundamental understanding of lower urinary tract function and its dysfunction after SCI, in addition to providing a platform for the assessment of potential therapies. Given the need to develop and evaluate novel assessment tools, as well as therapeutic approaches in animal models of SCI prior to human translation, urodynamics assessment techniques have been implemented to measure NLUTD function in a variety of animals, including rats, mice, cats, dogs and pigs. In this narrative review, we summarize the literature on the use of animal models for cystometry testing in the assessment of SCI-related NLUTD. We also discuss the advantages and disadvantages of various animal models, and opportunities for future research.

Molecular Mechanisms of Neurogenic Lower Urinary Tract Dysfunction after Spinal Cord Injury

This article provides a synopsis of current progress made in fundamental studies of lower urinary tract dysfunction (LUTD) after spinal cord injury (SCI) above the sacral level. Animal models of SCI allowed us to examine the effects of SCI on the micturition control and the underlying neurophysiological processes of SCI-induced LUTD. Urine storage and elimination are the two primary functions of the LUT, which are governed by complicated regulatory mechanisms in the central and peripheral nervous systems. These neural systems control the action of two functional units in the LUT: the urinary bladder and an outlet consisting of the bladder neck, urethral sphincters, and pelvic-floor striated muscles. During the storage phase, the outlet is closed, and the bladder is inactive to maintain a low intravenous pressure and continence. In contrast, during the voiding phase, the outlet relaxes, and the bladder contracts to facilitate adequate urine flow and bladder emptying. SCI disrupts the normal reflex circuits that regulate co-ordinated bladder and urethral sphincter function, leading to involuntary and inefficient voiding. Following SCI, a spinal micturition reflex pathway develops to induce an overactive bladder condition following the initial areflexic phase. In addition, without proper bladder-urethral-sphincter coordination after SCI, the bladder is not emptied as effectively as in the normal condition. Previous studies using animal models of SCI have shown that hyperexcitability of C-fiber bladder afferent pathways is a fundamental pathophysiological mechanism, inducing neurogenic LUTD, especially detrusor overactivity during the storage phase. SCI also induces neurogenic LUTD during the voiding phase, known as detrusor sphincter dyssynergia, likely due to hyperexcitability of Aδ-fiber bladder afferent pathways rather than C-fiber afferents. The molecular mechanisms underlying SCI-induced LUTD are multifactorial; previous studies have identified significant changes in the expression of various molecules in the peripheral organs and afferent nerves projecting to the spinal cord, including growth factors, ion channels, receptors and neurotransmitters. These findings in animal models of SCI and neurogenic LUTD should increase our understanding of pathophysiological mechanisms of LUTD after SCI for the future development of novel therapies for SCI patients with LUTD.

Therapeutic effects of KCC2 chloride transporter activation on detrusor overactivity in mice with spinal cord injury

This study aimed to clarify whether downregulation of K⁺-Cl^- cotransporter 2 (KCC2) in the sacral parasympathetic nucleus (SPN) of the lumbosacral spinal cord, from which the efferent pathway innervating the bladder originates, causes cellular hyperexcitability and triggers detrusor overactivity (DO) in spinal cord injury (SCI). SCI was produced by Th8-9 spinal cord transection in female C57BL/6 mice. At 4 wk after SCI, CLP290, a KCC2 activator, was administered, and cystometry was performed. Thereafter, neuronal activity with c-fos staining and KCC2 expression in cholinergic preganglionic parasympathetic neurons in the SPN was examined using immunohistochemistry. Firing properties of neurons in the SPN region were evaluated by extracellular recordings in the spinal cord slice preparations. DO evident as nonvoiding contractions was significantly reduced by CLP290 treatment in SCI mice. The number of c-fos-positive cells and coexpression of c-fos in choline acetyltransferase-positive cells were decreased in the SPN region of the SCI CLP290-treated group versus the SCI vehicle-treated group. KCC2 immunoreactivity was present on the cell membrane of SPN neurons and normalized fluorescence intensity of KCC2 in choline acetyltransferase-positive SPN neurons was decreased in the SCI vehicle-treated group versus the spinal intact vehicle-treated group but recovered in the SCI CLP290-treated group. Extracellular recordings showed that CLP290 suppressed the high-frequency firing activity of SPN neurons in SCI mice. These results indicated that SCI-induced DO is associated with downregulation of KCC2 in preganglionic parasympathetic neurons and that activation of KCC2 transporters can reduce DO, increase KCC2 expression in preganglionic parasympathetic neurons, and decrease neuronal firing of SPN neurons in SCI mice.NEW & NOTEWORTHY This study is the first report to suggest that activation of the Cl^- transporter K⁺-Cl^- cotransporter 2 may be a therapeutic modality for the treatment of spinal cord injury-induced detrusor overactivity by targeting bladder efferent pathways.

Therapeutic effects of a soluble guanylate cyclase activator, BAY 60-2770, on lower urinary tract dysfunction in mice with spinal cord injury

We aimed to evaluate the effects of a soluble guanylate cyclase (sGC) activator, BAY 60-2770, on neurogenic lower urinary tract dysfunction in mice with spinal cord injury (SCI). Mice were divided into the following three groups: spinal cord intact (group A), SCI + vehicle (group B), and SCI + BAY 60-2770 (group C). SCI mice underwent Th8-Th9 spinal cord transection and treatment with BAY 60-2770 (10 mg/kg/day) once daily for 2-4 wk after SCI. We evaluated urodynamic parameters using awake cystometry and external urethral sphincter electromyograms (EMG); mRNA levels of mechanosensory channels, nitric oxide (NO)-, ischemia-, and inflammation-related markers in L6-S1 dorsal root ganglia, the urethra, and bladder tissues; and protein levels of cGMP in the urethra at 4 wk after SCI. With awake cystometry, nonvoiding contractions, postvoid residual, and bladder capacity were significantly larger in group B than in group C. Voiding efficiency (VE) was significantly higher in group C than in group B. In external urethral sphincter EMGs, the duration of notch-like reductions in intravesical pressure and reduced EMG activity time were significantly longer in group C than in group B. mRNA expression levels of transient receptor potential ankyrin 1, transient receptor potential vanilloid 1, acid-sensing ion channel (ASIC)1, ASIC2, ASIC3, and Piezo2 in the dorsal root ganglia, and hypoxia-inducible factor-1α, VEGF, and transforming growth factor-β1 in the bladder were significantly higher in group B than in groups A and C. mRNA levels of neuronal NO synthase, endothelial NO synthase, and sGCα1 and protein levels of cGMP in the urethra were significantly lower in group B than in groups A and C. sGC modulation might be useful for the treatment of SCI-related neurogenic lower urinary tract dysfunction.NEW & NOTEWORTHY This is the first report to evaluate the effects of a soluble guanylate cyclase activator, BAY 60-2770, on neurogenic lower urinary tract dysfunction in mice with spinal cord injury.

Neuroprotective Effects of Estrogen Through BDNF-Transient Receptor Potential Channels 6 Signaling Pathway in the Hippocampus in a Rat Model of Perimenopausal Depression

Estradiol (E₂) has been proven to be effective in treating perimenopausal depression (PD); however, the downstream signaling pathways have not been fully elucidated. Transient receptor potential channels 6 (TRPC6) plays a vital role in promoting neuronal development and the formation of excitatory synapses. At present, we found that the serum levels of E₂ and brain-derived neurotrophic factor (BDNF) declined significantly in the women with PD compared to perimenopausal women, which was accompanied by a clear reduction in TRPC6 levels. To further reveal the effects of TRPC6 on neuronal survival and excitability, the PD-like rat model was established by the total removal of left ovary and 80% removal of right ovary followed by 21 days of the chronic unpredictable mild stress. Intragastric administration of E₂ (2 mg/kg), intraperitoneal injection of BDNF/TrB signaling pathway inhibitor (K252a, 100 μg/kg) and TRPC6 agonist (OAG, 0.6 mg/kg), and intracerebroventricular infusion of anti-BDNF antibody for blocking BDNF (0.5 μg/24 μl/rat) daily for 21 days were conducted. The levels of BDNF and TRPC6 in rat serum were lower in PD rats compared to the control rats; the depression-like behavior was induced, the neuronal death rate in the hippocampus increased, and the thickness of postsynaptic density (PSD) and the number of asymmetric synapses decreased significantly in the PD group. E₂ treatment greatly upregulated the serum levels of BDNF and TRPC6, the neuronal excitability indicated by an elevation in the PSD thickness and the numbers of asymmetric synapses, and these actions were reversed by K252a; co-administration of TRPC6 agonist and K252a improved neuronal degeneration and increased the neuronal excitability induced in the E₂-treated PD rats. K252a or anti-BDNF antibody inhibited the increased neuronal BDNF and TRPC6 expression in E₂-treated PD rats; co-treatment of TRPC6 agonist and anti-BDNF antibody reduced neuronal death and increased the BDNF and TRPC6 expression in the hippocampal CA1 neurons in the E₂-treated PD rats. These results suggest that the neuroprotective role of E₂ in PD is closely related to enhance the activity of BDNF/TRPC6 pathway and is helpful to provide new prevention and strategies.

Targeting neurotrophin and nitric oxide signaling to treat spinal cord injury and associated neurogenic bladder overactivity

Purpose or the research

Nearly 300,000 people are affected by spinal cord injury (SCI) with approximately 18,000 new cases annually, according to the National SCI Statistics Center. SCI affects physical mobility and impairs the function of multiple internal organs to cause lower urinary tract (LUT) dysfunctions manifesting as detrusor sphincter dyssynergia (DSD) and neurogenic detrusor overactivity (NDO) with detrimental consequences to the quality of life and increased morbidity. Multiple lines of evidence now support time dependent evolution of the complex SCI pathology which requires a multipronged treatment approach of immediate, specialized care after spinal cord trauma bookended by physical rehabilitation to improve the clinical outcomes. Instead of one size fits all treatment approach, we propose adaptive drug treatment to counter the time dependent evolution of SCI pathology, with three small molecule drugs with distinctive sites of action for the recovery of multiple functions.

Principal results

Our findings demonstrate the improvement in the recovery of hindlimb mobility and bladder function of spinal cord contused mice following administration of small molecules targeting neurotrophin receptors, LM11A-31 and LM22B-10. While LM11A-31 reduced the cell death in the spinal cord, LM22B-10 promoted cell survival and axonal growth. Moreover, the soluble guanylate cyclase (sGC) activator, cinaciguat, enhanced the revascularization of the SCI injury site to promote vessel formation, dilation, and increased perfusion.

Major conclusions

Our adaptive three drug cocktail targets different stages of SCI and LUTD pathology: neuroprotective effect of LM11A-31 retards the cell death that occurs in the early stages of SCI; and LM22B-10 and cinaciguat promote neural remodeling and reperfusion at later stages to repair spinal cord scarring, DSD and NDO. LM11A-31 and cinaciguat have passed phase I and IIa clinical trials and possess significant potential for accelerated clinical testing in SCI/LUTD patients.

Current knowledge and novel frontiers in lower urinary tract dysfunction after spinal cord injury: Basic research perspectives

This review article aims to summarize the recent advancement in basic research on lower urinary tract dysfunction (LUTD) following spinal cord injury (SCI) above the sacral level. We particularly focused on the neurophysiologic mechanisms controlling the lower urinary tract (LUT) function and the SCI-induced changes in micturition control in animal models of SCI. The LUT has two main functions, the storage and voiding of urine, that are regulated by a complex neural control system. This neural system coordinates the activity of two functional units in the LUT: the urinary bladder and an outlet including bladder neck, urethra, and striated muscles of the pelvic floor. During the storage phase, the outlet is closed and the bladder is quiescent to maintain a low intravesical pressure and continence, and during the voiding phase, the outlet relaxes and the bladder contracts to promote efficient release of urine. SCI impairs voluntary control of voiding as well as the normal reflex pathways that coordinate bladder and sphincter function. Following SCI, the bladder is initially areflexic but then becomes hyperreflexic due to the emergence of a spinal micturition reflex pathway. However, the bladder does not empty efficiently because coordination between the bladder and urethral sphincter is lost. In animal models of SCI, hyperexcitability of silent C-fiber bladder afferents is a major pathophysiological basis of neurogenic LUTD, especially detrusor overactivity. Reflex plasticity is associated with changes in the properties of neuropeptides, neurotrophic factors, or chemical receptors of afferent neurons. Not only C-fiber but also Aδ-fiber could be involved in the emergence of neurogenic LUTD such as detrusor sphincter dyssynergia following SCI. Animal research using disease models helps us to detect the different contributing factors for LUTD due to SCI and to find potential targets for new treatments.

Time-dependent progression of neurogenic lower urinary tract dysfunction after spinal cord injury in the mouse model

This study evaluated the time-course changes in bladder and external urinary sphincter (EUS) activity and the expression of mechanosensitive channels in lumbosacral dorsal root ganglia (DRG) after spinal cord injury (SCI). Female C57BL/6N mice in the SCI group underwent transection of the Th8/9 spinal cord. Spinal intact mice and SCI mice at 2, 4, and 6 wk post-SCI were evaluated by single-filling cystometry and EUS-electromyography (EMG). In another set of mice, the bladder and L6-S1 DRG were harvested for protein and mRNA analyses. In SCI mice, nonvoiding contractions were confirmed at 2 wk post-SCI and did not increase over time to 6 wk. In 2-wk SCI mice, EUS-EMG measurements revealed detrusor sphincter dyssynergia, but periodic EMG reductions during bladder contraction were hardly observed. At 4 wk, SCI mice showed increases of EMG activity reduction time with increased voiding efficiency. At 6 wk, SCI mice exhibited a further increase in EMG reduction time. RT-PCR of L6-S1 DRG showed increased mRNA levels of transient receptor potential vanilloid 1 and acid-sensing ion channels (ASIC1-ASIC3) in SCI mice with a decrease of ASIC2 and ASIC3 at 6 wk compared with 4 wk, whereas Piezo2 showed a slow increase at 6 wk. Protein assay showed SCI-induced overexpression of bladder brain-derived neurotrophic factor with a time-dependent decrease post-SCI. These results indicate that detrusor overactivity is established in the early phase, whereas detrusor sphincter dyssynergia is completed later at 4 wk with an improvement at 6 wk post-SCI, and that mechanosensitive channels may be involved in the time-dependent changes.NEW & NOTEWORTHY This is the first paper to evaluate the time-course changes of bladder dysfunction associated with mechanosensitive channels in a mouse model.

Inhibiting BDNF/TrkB.T1 receptor improves resiniferatoxin-induced postherpetic neuralgia through decreasing ASIC3 signaling in dorsal root ganglia

BACKGROUND

Postherpetic neuralgia (PHN) is a devastating complication after varicella-zoster virus infection. Brain-derived neurotrophic factor (BDNF) has been shown to participate in the pathogenesis of PHN. A truncated isoform of the tropomyosin receptor kinase B (TrkB) receptor TrkB.T1, as a high-affinity receptor of BDNF, is upregulated in multiple nervous system injuries, and such upregulation is associated with pain. Acid-sensitive ion channel 3 (ASIC3) is involved in chronic neuropathic pain, but its relation with BDNF/TrkB.T1 in the peripheral nervous system (PNS) during PHN is unclear. This study aimed to investigate whether BDNF/TrkB.T1 contributes to PHN through regulating ASIC3 signaling in dorsal root ganglia (DRGs).

METHODS

Resiniferatoxin (RTX) was used to induce rat PHN models. Mechanical allodynia was assessed by measuring the paw withdrawal thresholds (PWTs). Thermal hyperalgesia was determined by detecting the paw withdrawal latencies (PWLs). We evaluated the effects of TrkB.T1-ASIC3 signaling inhibition on the behavior, neuronal excitability, and inflammatory response during RTX-induced PHN. ASIC3 short hairpin RNA (shRNA) transfection was used to investigate the effect of exogenous BDNF on inflammatory response in cultured PC-12 cells.

RESULTS

RTX injection induced mechanical allodynia and upregulated the protein expression of BDNF, TrkB.T1, ASIC3, TRAF6, nNOS, and c-Fos, as well as increased neuronal excitability in DRGs. Inhibition of ASIC3 reversed the abovementioned effects of RTX, except for BDNF and TrkB.T1 protein expression. In addition, inhibition of TrkB.T1 blocked RTX-induced mechanical allodynia, activation of ASIC3 signaling, and hyperexcitability of neurons. RTX-induced BDNF upregulation was found in both neurons and satellite glia cells in DRGs. Furthermore, exogenous BDNF activated ASIC3 signaling, increased NO level, and enhanced IL-6, IL-1β, and TNF-α levels in PC-12 cells, which was blocked by shRNA-ASIC3 transfection.

CONCLUSION

These findings demonstrate that inhibiting BDNF/TrkB.T1 reduced inflammation, decreased neuronal hyperexcitability, and improved mechanical allodynia through regulating the ASIC3 signaling pathway in DRGs, which may provide a novel therapeutic target for patients with PHN.

Effects of a new β3-adrenoceptor agonist, vibegron, on neurogenic bladder dysfunction and remodeling in mice with spinal cord injury

AIMS

To examine vibegron effects on lower urinary tract dysfunction (LUTD) in mice with spinal cord injury (SCI).

METHODS

Female mice underwent Th8-9 spinal cord transection and were orally administered vehicle or vibegron after SCI. We evaluated urodynamic parameters at 4 weeks after SCI with or without vibegron. Fibrosis- and ischemia-related messenger RNA (mRNA) and protein levels of collagen and elastin were measured in bladders of vehicle- and vibegron-treated SCI mice, and spinal intact mice.

RESULTS

Non-voiding contractions (NVCs) were significantly fewer (15.3 ± 8.9 vs 29.7 ± 11.4 contractions; P < .05) and the time to the first NVC was significantly longer (1488.0 ± 409.5 vs 782.7 ± 399.7 seconds; P < .01) in vibegron-treated SCI mice vs vehicle-treated SCI mice. mRNAs levels of collagen types 1 and 3, transforming growth factor-β1 (TGF-β1), and hypoxia-inducible factor-1α (HIF-1α) were significantly upregulated in vehicle-treated SCI mice compared with spinal intact and vibegron-treated SCI mice (Col 1: 3.5 vs 1.0 and 2.0-fold; P < .01 and P < .05, Col 3: 2.1 vs 1.0 and 1.2-fold; P < .01 and P < .05, TGF-β1: 1.2 vs 1.0 and 0.9-fold; P < .05 and P < .05, HIF-1α: 1.4 vs 1.0 and 1.0-fold; P < .05 and P < .01). Total collagen and elastin protein levels in vehicle- and vibegron-treated SCI mice did not differ.

CONCLUSIONS

Vibegron reduced NVCs, delayed the first NVC, and improved collagen types 1 and 3, TGF-β1, and HIF-1α mRNA expression in SCI mice. Vibegron might be effective for SCI-induced LUTD.