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Chen X, Lv R, Li M, Zhang L, Sun Y, Cao N, Gu B. The serotonin(5-HT)2A receptor is involved in the hypersensitivity of bladder afferent neurons in cyclophosphamide-induced cystitis. Eur J Pharmacol 2024; 982:176909. [PMID: 39154826 DOI: 10.1016/j.ejphar.2024.176909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Revised: 07/14/2024] [Accepted: 08/15/2024] [Indexed: 08/20/2024]
Abstract
Interstitial cystitis/bladder pain syndrome (IC/BPS) is a chronic bladder inflammation characterized by the main symptoms of urinary frequency, urgency, and pelvic pain. The hypersensitivity of bladder afferent neurons is considered a significant pathophysiologic mechanism in IC/PBS. Serotonin (5-HT, 5-hydroxytryptamine) receptors are known to be involved in the regulation of the micturition reflex and hyperalgesia, but the effect of 5-HT receptors on cystitis remains unknown. In this study, a rat model of interstitial cystitis induced by intraperitoneal injection of cyclophosphamide (CYP) was used to investigate the role of 5-HT receptors on cystitis. The histology and urodynamics exhibited chronic cystitis and overactive bladder in CYP-treated rats. Notably, among 5-HT1A, 5-HT2A and 5-HT7 receptors, the expression of 5-HT2A receptor was significantly increased in bladder afferent neurons in CYP-treated rats. Intrathecal administration of the 5-HT2A receptor antagonist M100907 could alleviate bladder overactivity and hyperalgesia in CYP-induced cystitis rats. Neuronal calcium imaging of bladder afferent neurons revealed increased calcium influx induced by the 5-HT2A receptor agonist or capsaicin in cystitis rats, which could be inhibited by M100907. Moreover, RNA sequencing indicated that differentially expressed genes were enriched in inflammation-related pathways and cellular calcium homeostasis. These findings suggest that the 5-HT2A receptor is involved in the hypersensitivity of bladder afferent neurons in CYP-induced cystitis, and M100907 could alleviate bladder overactivity and hyperalgesia in CYP-induced cystitis by inhibiting neuronal hypersensitivity in the afferent pathways. The 5-HT2A receptor may be a potential therapeutic target for the treatment of IC/BPS.
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MESH Headings
- Animals
- Cyclophosphamide
- Urinary Bladder/drug effects
- Urinary Bladder/innervation
- Urinary Bladder/pathology
- Urinary Bladder/metabolism
- Neurons, Afferent/metabolism
- Neurons, Afferent/drug effects
- Receptor, Serotonin, 5-HT2A/metabolism
- Rats
- Rats, Sprague-Dawley
- Cystitis/chemically induced
- Cystitis/metabolism
- Cystitis/pathology
- Female
- Hyperalgesia/chemically induced
- Hyperalgesia/metabolism
- Cystitis, Interstitial/chemically induced
- Cystitis, Interstitial/metabolism
- Cystitis, Interstitial/drug therapy
- Cystitis, Interstitial/pathology
- Serotonin 5-HT2 Receptor Antagonists/pharmacology
- Urinary Bladder, Overactive/chemically induced
- Urinary Bladder, Overactive/metabolism
- Urinary Bladder, Overactive/physiopathology
- Urinary Bladder, Overactive/drug therapy
- Disease Models, Animal
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Affiliation(s)
- Xun Chen
- Department of Urology, Shanghai Sixth's People's Hospital Affiliated Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Rong Lv
- Department of Urology, Shanghai Sixth's People's Hospital Affiliated Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Mingzhuo Li
- Department of Urology, Shanghai Sixth's People's Hospital Affiliated Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Lin Zhang
- Department of Urology, Shanghai Sixth's People's Hospital Affiliated Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yudong Sun
- Department of Urology, Shanghai Sixth's People's Hospital Affiliated Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Nailong Cao
- Department of Urology, Shanghai Sixth's People's Hospital Affiliated Shanghai Jiao Tong University School of Medicine, Shanghai, China.
| | - Baojun Gu
- Department of Urology, Shanghai Sixth's People's Hospital Affiliated Shanghai Jiao Tong University School of Medicine, Shanghai, China.
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Aghili SH, Manavi MA, Panji M, Farhang Ranjbar M, Abrishami R, Dehpour AR. Mirtazapine Improves Locomotor Activity and Attenuates Neuropathic Pain Following Spinal Cord Injury in Rats via Neuroinflammation Modulation. Neurochem Res 2024:10.1007/s11064-024-04240-7. [PMID: 39271550 DOI: 10.1007/s11064-024-04240-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2024] [Revised: 05/16/2024] [Accepted: 09/03/2024] [Indexed: 09/15/2024]
Abstract
Neuroinflammation-related locomotor deficits and neuropathic pain are expected outcomes of spinal cord injury (SCI). The atypical antidepressant mirtazapine has exhibited potential neuroprotective and anti-inflammatory effects. This research aims to investigate the impacts of mirtazapine on post-SCI neuropathic pain and locomotor recovery, with a particular focus on neuroinflammation. The study utilized 30 male Wistar rats divided into five groups: Sham, SCI with vehicle treatment, and SCI administered with mirtazapine (3, 10, and 30 mg/kg/day, ip, for one week). Locomotor activity was assessed using the Basso, Beattie, and Bresnahan (BBB) scale. Mechanical, thermal, and cold allodynia were assessed using von-Frey filaments, tail flick latency, and the acetone test, respectively. ELISA was utilized to measure cytokines, while Western blotting was used to determine TRPV1 channel, 5-HT2A receptor, NLRP3, and iNOS expression. Histopathological analyses were also examined, including hematoxylin and eosin (H&E) and Luxol fast blue (LFB) staining. Mirtazapine (10 and 30 mg/kg/day) significantly improved locomotor recovery according to BBB score. It attenuated mechanical, thermal, and cold allodynia post-SCI. Moreover, it decreased pro-inflammatory cytokines TNF-α, IL-1β, IL-6, and IL-18, while increasing anti-inflammatory cytokine IL-4 and IL-10. Furthermore, it downregulated iNOS, NLRP3, and TRPV1 expression and upregulated the 5-HT2A receptor. H&E and LFB staining further revealed attenuated tissue damage and decreased demyelination. Our findings suggest that mirtazapine can alleviate neuropathic pain and reinforce locomotor recovery post-SCI by modulating neuroinflammatory responses, NLRP3, iNOS, TRPV1 channel, and 5-HT2A receptor expression.
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Affiliation(s)
- Seyed Hadi Aghili
- Research Center for Trauma in Police Operations, Directorate of Health, Rescue & Treatment, Police Headquarter, Tehran, Iran
- Neurosurgery Department, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran
- Department of Neurosurgery, Valiasr Hospital, Tehran, Iran
| | - Mohammad Amin Manavi
- Experimental Medicine Research Center, Tehran University of Medical Sciences, P.O. Box 13145-784, Tehran, Iran
| | - Mohammad Panji
- Research Center for Life, Health Sciences & Biotechnology of the Police, Directorate of Health, Rescue & Treatment, Police Headquarters, Tehran, Iran
| | - Mehri Farhang Ranjbar
- Department of Support and Services Management, Institute of Management and Organizational Resources, Policing Sciences and Social Studies Research Institute, Tehran, Iran
| | - Ramin Abrishami
- Research Center for Trauma in Police Operations, Directorate of Health, Rescue & Treatment, Police Headquarter, Tehran, Iran.
- Department of Clinical Pharmacy, Faculty of Pharmacy, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran.
| | - Ahmad Reza Dehpour
- Experimental Medicine Research Center, Tehran University of Medical Sciences, P.O. Box 13145-784, Tehran, Iran.
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
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Lv R, Li M, Chen X, Li S, Cao N, Gu B. Serotonin (5-HT) 2A/2C receptor agonist 2,5-dimethoxy-4-iodophenyl-2-aminopropane hydrochloride improves detrusor sphincter dyssynergia by inhibiting L-type voltage-gated calcium channels in spinal cord injured rats. CNS Neurosci Ther 2024; 30:e14890. [PMID: 39097910 PMCID: PMC11298198 DOI: 10.1111/cns.14890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Revised: 06/11/2024] [Accepted: 07/17/2024] [Indexed: 08/06/2024] Open
Abstract
AIMS To explore the role of voltage-gated calcium channels (VGCC) in 5-HT2A/2C receptor agonist 2,5-dimethoxy-4-iodophenyl-2-aminopropane hydrochloride's improvement of spinal cord injury (SCI) induced detrusor sphincter dyssynergia and the expressions of the 5-hydroxy tryptamine (5-HT) 2A receptors and VGCCs in lumbosacral cord after SCI. METHODS Female Sprague-Dawley rats were randomized into normal control group and SCI group (N = 15 each). Cystometrogram (CMG), simultaneous CMG, and external urethral sphincter electromyography (EUS-EMG) were conducted in all groups under urethane anesthesia. Drugs were administered intrathecally during CMG and EUS-EMG. Rats were euthanized and L6-S1 spinal cord were acquired for immunofluorescence. RESULTS In SCI rats, intrathecal administration of 2,5-dimethoxy-4-iodophenyl-2-aminopropane hydrochloride or L-type VGCC blocker, nifedipine, could significantly increase voiding volume, voiding efficiency, and the number of high-frequency oscillations. They could also prolong EUS bursting activity duration on EUS-EMG. Moreover, the effect of 2,5-dimethoxy-4-iodophenyl-2-aminopropane hydrochloride can be eliminated with the combined administration of L-type VGCC agonist, (±)-Bay K 8644. No significant differences were observed in CMG after intrathecal administration of T-type VGCC blocker TTA-P2. Additionally, immunofluorescence of the lumbosacral cord in control and SCI rats showed that the 5-HT2A receptor and Cav1.2 immunolabeling-positive neurons in the anterior horn of the lumbosacral cord were increased in SCI rats. CONCLUSIONS Our study demonstrated that 5-HT2A/2C agonist 2,5-dimethoxy-4-iodophenyl-2-aminopropane hydrochloride may improve SCI-induced DSD by inhibiting the L-type voltage-gated calcium channel in lumbosacral cord motoneurons.
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Affiliation(s)
- Rong Lv
- Department of UrologyShanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of MedicineShanghaiChina
| | - Mingzhuo Li
- Department of UrologyShanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of MedicineShanghaiChina
| | - Xun Chen
- Department of UrologyShanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of MedicineShanghaiChina
| | - Shengtian Li
- Bio‐X Institutes, Key laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Key Laboratory of Psychotic Disorders, Brain Science and Technology Research CenterShanghai Jiao Tong UniversityShanghaiChina
| | - Nailong Cao
- Department of UrologyShanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of MedicineShanghaiChina
| | - Baojun Gu
- Department of UrologyShanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of MedicineShanghaiChina
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Lin CY, Li K, Thalluri R, Lee YS. Upregulated 5-HT 1A Receptors Regulate Lower Urinary Tract Function in Rats after Complete Spinal Cord Injury. J Neurotrauma 2023; 40:845-861. [PMID: 36762948 PMCID: PMC10162122 DOI: 10.1089/neu.2022.0329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023] Open
Abstract
Spinal cord injury (SCI) above the lumbosacral level often leads to dysfunction of the lower urinary tract (LUT) including detrusor hyper-reflexia, wherein bladder compliance is low, baseline pressures are increased, and filling is accompanied by numerous non-voiding contractions (NVCs) referred to as neurogenic detrusor overactivity. Here, we investigate the expression levels of the serotonin 1A (5-HT1A) receptor in segments both rostral and caudal to the injured site, as well as the effects on micturition of blocking 5-HT1A receptor using pharmacological interventions in spinally intact rats or T8 complete SCI rats. The activities of detrusor and external urethral sphincter (EUS) were assessed with the rats in a conscious condition. Adult female rats were divided into two groups: (1) sham control (T8 laminectomy only) and (2) T8 complete spinal cord transection. The observation period was 2 months after the original SCI. In Western blot analyses, we identified significant upregulation of the 5-HT1A receptor in the T10-L2 and L6/S1 segments after chronic complete SCI. In pharmacological studies, a dose-response study of the 5-HT1A receptor antagonist, WAY100635, indicated alterations in detrusor and EUS activities in spinally intact rats. Interestingly, blocking the 5-HT1A receptor alone resulted in inhibitory effects on NVCs with a reduced number and decreased amplitude, but in an increased interval between NVCs in SCI rats. In addition, the duration of EUS bursting was also significantly increased by WAY100635. These inhibitory effects of WAY100635 on NVCs were diminished by subsequent application of a beta-adrenergic blocker (propranolol). The reduction of NVCs observed by WAY100635 may be the result of blocking the constitutive activities of the 5-HT1A receptor but activating the beta-adrenergic sympathetic pathway, which in turn relaxes bladder activity. Together, the neuroplasticity of the 5-HT1A receptor can be a potential therapeutic target for treatment of bladder dysfunction after SCI.
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Affiliation(s)
- Ching-Yi Lin
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Kevin Li
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Rajaa Thalluri
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Yu-Shang Lee
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA
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Shimizu N, Saito T, Wada N, Hashimoto M, Shimizu T, Kwon J, Cho KJ, Saito M, Karnup S, de Groat WC, Yoshimura N. Molecular Mechanisms of Neurogenic Lower Urinary Tract Dysfunction after Spinal Cord Injury. Int J Mol Sci 2023; 24:7885. [PMID: 37175592 PMCID: PMC10177842 DOI: 10.3390/ijms24097885] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 04/21/2023] [Accepted: 04/22/2023] [Indexed: 05/15/2023] Open
Abstract
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.
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Affiliation(s)
- Nobutaka Shimizu
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA; (N.S.)
- Pelvic Floor Center, Kochi Medical School, Kochi University, Nankoku 783-8505, Japan
| | - Tetsuichi Saito
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA; (N.S.)
| | - Naoki Wada
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA; (N.S.)
| | - Mamoru Hashimoto
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA; (N.S.)
| | - Takahiro Shimizu
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA; (N.S.)
- Department of Pharmacology, Kochi Medical School, Kochi University, Nankoku 783-8505, Japan
| | - Joonbeom Kwon
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA; (N.S.)
| | - Kang Jun Cho
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA; (N.S.)
| | - Motoaki Saito
- Department of Pharmacology, Kochi Medical School, Kochi University, Nankoku 783-8505, Japan
| | - Sergei Karnup
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - William C. de Groat
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Naoki Yoshimura
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA; (N.S.)
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15213, USA
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Chen J, Wang L, Liu M, Gao G, Zhao W, Fu Q, Wang Y. Implantation of adipose-derived mesenchymal stem cell sheets promotes axonal regeneration and restores bladder function after spinal cord injury. Stem Cell Res Ther 2022; 13:503. [PMID: 36224621 PMCID: PMC9558366 DOI: 10.1186/s13287-022-03188-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2022] [Accepted: 09/30/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Cell-based therapy using adipose-derived mesenchymal stem cells (ADSCs) is a promising treatment strategy for neurogenic bladder (NB) associated with spinal cord injury (SCI). However, therapeutic efficacy is low because of inefficient cell delivery. Cell sheets improve the efficacy of cell transplantation. Therefore, this study was conducted to investigate the therapeutic efficacy of transplanting ADSC sheets into an SCI rat model and focused on the function and pathological changes of the bladder. METHODS ADSC sheets were prepared from adipose tissue of Sprague-Dawley (SD) rats using temperature-responsive cell culture dishes. Adult female SD rats were subjected to SCI by transection at the T10 level and administered ADSC sheets or gelatin sponge (the control group). Four and 8 weeks later, in vivo cystometrograms were obtained for voiding function assessment. Rats were sacrificed and the expression of various markers was analyzed in spinal and bladder tissues. RESULTS The number of β-tubulin III-positive axons in the ADSC sheet transplantation group was higher than that in the control group. Conversely, expression of glial fibrillary acidic protein in the ADSC sheet transplantation group was lower than that in the control group. Cystometry showed impairment of the voiding function after SCI, which was improved after ADSC sheet transplantation with increased high-frequency oscillation activity. Furthermore, ADSC sheet transplantation prevented disruption of the bladder urothelium in SCI rats, thereby maintaining the intact barrier. Compared with fibrosis of the bladder wall in the control group, the ADSC sheet transplantation group had normal morphology of the bladder wall and reduced tissue fibrosis as shown by downregulation of type 1 collagen. ADSC sheet transplantation also resulted in strong upregulation of contractile smooth muscle cell (SMC) markers (α-smooth muscle actin and smoothelin) and downregulation of synthetic SMC markers (MYH10 and RBP1). CONCLUSION ADSC sheet transplantation significantly improved voiding function recovery in rats after SCI. ADSC sheet transplantation is a promising cell delivery and treatment option for NB related to SCI.
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Affiliation(s)
- Jiasheng Chen
- Department of Urology, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai Eastern Institute of Urologic Reconstruction, Shanghai Jiao Tong University, Shanghai, China
| | - Lin Wang
- Department of Urology, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai Eastern Institute of Urologic Reconstruction, Shanghai Jiao Tong University, Shanghai, China
| | - Meng Liu
- Department of Urology, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai Eastern Institute of Urologic Reconstruction, Shanghai Jiao Tong University, Shanghai, China
| | - Guo Gao
- Key Laboratory for Thin Film and Micro Fabrication of the Ministry of Education, School of Sensing Science and Engineering, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Weixin Zhao
- Wake Forest Institute for Regenerative Medicine, Winston Salem, NC, USA
| | - Qiang Fu
- Department of Urology, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai Eastern Institute of Urologic Reconstruction, Shanghai Jiao Tong University, Shanghai, China.
| | - Ying Wang
- Department of Urology, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai Eastern Institute of Urologic Reconstruction, Shanghai Jiao Tong University, Shanghai, China.
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Delivery of the 5-HT 2A Receptor Agonist, DOI, Enhances Activity of the Sphincter Muscle during the Micturition Reflex in Rats after Spinal Cord Injury. BIOLOGY 2021; 10:biology10010068. [PMID: 33477834 PMCID: PMC7832846 DOI: 10.3390/biology10010068] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Revised: 01/10/2021] [Accepted: 01/15/2021] [Indexed: 11/17/2022]
Abstract
Simple Summary Spinal cord injury often disrupts connections between the brain and spinal cord leading to a plethora of health complications, including bladder dysfunction. Spinal cord injured patients are left with symptoms such as a leaky bladder (the inability to hold their urine), frequent urinary tract infections, and potential kidney failure. However, previous studies have shown that manipulation of serotoninergic receptors can improve urinary performance following spinal cord injury. In the current study, we sought to explore how stimulation of a specific serotonergic receptor subtype can significantly enhance bladder function in spinal cord injured rats. To do so, we utilized spinal cord injured female rats that underwent various bladder performance evaluations combined with pharmacological intervention of a specific serotonergic subtype. Additionally, the primary site of action was investigated to determine effects elicited during various administration routes (e.g., directly into the cord, into the femoral vein, or into the skin). Stimulation of this receptor subtype, regardless of delivery route, improved activity of the external urethral sphincter and detrusor-sphincter coordination in spinal cord injured rats. Collectively, the results of these experiments have the potential to provide vital guidance for the development of therapeutic strategies to alleviate urinary dysfunction following spinal cord injury. Abstract Traumatic spinal cord injury (SCI) interrupts spinobulbospinal micturition reflex pathways and results in urinary dysfunction. Over time, an involuntary bladder reflex is established due to the reorganization of spinal circuitry. Previous studies show that manipulation of serotonin 2A (5-HT2A) receptors affects recovered bladder function, but it remains unclear if this receptor regulates the activity of the external urethral sphincter (EUS) following SCI. To elucidate how central and peripheral serotonergic machinery acts on the lower urinary tract (LUT) system, we employed bladder cystometry and EUS electromyography recordings combined with intravenous or intrathecal pharmacological interventions of 5-HT2A receptors in female SCI rats. Three to four weeks after a T10 spinal transection, systemic and central blockage of 5-HT2A receptors with MDL only slightly influenced the micturition reflex. However, delivery of the 5-HT2A receptor agonist, DOI, increased EUS tonic activity and elicited bursting during voiding. Additionally, subcutaneous administration of DOI verified the enhancement of continence and voiding capability during spontaneous micturition in metabolic cage assays. Although spinal 5HT2A receptors may not be actively involved in the recovered micturition reflex, stimulating this receptor subtype enhances EUS function and the synergistic activity between the detrusor and sphincter to improve the micturition reflex in rats with SCI.
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Cao N, Huang J, Ni J, Si J, Gu B, Wang Z, Andersson KE. Streptozotocin-induced diabetes causes upregulation of serotonin (5-HT)2A/C receptors in lumbosacral cord motoneurons and down regulation of serotonergic paraneurons in the urethra. Brain Res 2019; 1715:21-26. [DOI: 10.1016/j.brainres.2019.03.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 03/11/2019] [Accepted: 03/13/2019] [Indexed: 01/12/2023]
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Salazar BH, Hoffman KA, Zhang C, Zhang Y, Cruz Y, Boone TB, Munoz A. Modulatory effects of intravesical P2X2/3 purinergic receptor inhibition on lower urinary tract electromyographic properties and voiding function of female rats with moderate or severe spinal cord injury. BJU Int 2019; 123:538-547. [PMID: 30255543 PMCID: PMC6715153 DOI: 10.1111/bju.14561] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
OBJECTIVES To evaluate the role that intravesical P2X2/3 purinergic receptors (P2X2/3Rs) play in early and advanced neurogenic lower urinary tract (LUT) dysfunction after contusion spinal cord injury (SCI) in female rats. MATERIALS AND METHODS Female Sprague-Dawley rats received a thoracic Th8/Th9 spinal cord contusion with either force of 100 kDy (cN); moderate) or 150 kDy (cN; severe); Sham rats had no injury. Evaluations on urethane-anesthetised rats were conducted at either 2 or 4 weeks after SCI. LUT electrical signals and changes in bladder pressure were simultaneously recorded using cystometry and a set of custom-made flexible microelectrodes, before and after intravesical application of the P2X2/3R antagonist AF-353 (10 μM), to determine the contribution of P2X2/3R-mediated LUT modulation. RESULTS Severe SCI significantly increased bladder contraction frequency, and reduced both bladder pressure amplitude and intraluminal-pressure high-frequency oscillations (IPHFO). Intravesical P2X2/3R inhibition did not modify bladder pressure or IPHFO in the Sham and moderate-SCI rats, although did increase the intercontractile interval (ICI). At 2 weeks after SCI, the Sham and moderate-SCI rats had significant LUT electromyographic activity during voiding, with a noticeable reduction in LUT electrical signals seen at 4 weeks after SCI. Intravesical inhibition of P2X2/3R increased the ICI in the Sham and moderate-SCI rats at both time-points, but had no effect on rats with severe SCI. The external urethral sphincter (EUS) showed strong and P2X2/3R-independent electrical signals in the Sham and moderate-SCI rats in the early SCI stage. At 4 weeks after SCI, the responsiveness of the EUS was significantly attenuated, independently of SCI intensity. CONCLUSIONS This study shows that electrophysiological properties of the LUT are progressively impaired depending on SCI intensity and that intravesical P2X2/3R inhibition can attenuate electrical activity in the neurogenic LUT at early, but not at semi-chronic SCI. This translational study should be useful for planning clinical evaluations.
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Affiliation(s)
- Betsy H. Salazar
- Regenerative Medicine and Tissue Engineering Program-Urology, Houston Methodist Research Institute
| | - Kristopher A. Hoffman
- Regenerative Medicine and Tissue Engineering Program-Urology, Houston Methodist Research Institute
| | - Chuan Zhang
- Regenerative Medicine and Tissue Engineering Program-Urology, Houston Methodist Research Institute
- Department of Biomedical Engineering University of Houston
- Guangdong Provincial Work Injury Rehabilitation Hospital, Guangdong, China
| | - Yingchun Zhang
- Regenerative Medicine and Tissue Engineering Program-Urology, Houston Methodist Research Institute
- Department of Biomedical Engineering University of Houston
- Guangdong Provincial Work Injury Rehabilitation Hospital, Guangdong, China
| | - Yolanda Cruz
- Centro Tlaxcala de Biología de la Conducta, Universidad Autónoma de Tlaxcala, México
| | - Timothy B. Boone
- Regenerative Medicine and Tissue Engineering Program-Urology, Houston Methodist Research Institute
- Department of Urology, Houston Methodist Hospital
| | - Alvaro Munoz
- Regenerative Medicine and Tissue Engineering Program-Urology, Houston Methodist Research Institute
- Centro Universitario del Norte, Universidad de Guadalajara, Colotlán, México
- Corresponding Author: Alvaro Munoz, PhD, Current affiliation: Centro Universitario del Norte, Universidad de Guadalajara, Carretera Federal No. 23, Km. 191, C.P. 46200, Colotlán, Jalisco, México., / Tel: +52-33-1058-5200 (Ext. 33679) / Fax: +1713-441-6463
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Intraspinal Grafting of Serotonergic Neurons Modifies Expression of Genes Important for Functional Recovery in Paraplegic Rats. Neural Plast 2018; 2018:4232706. [PMID: 30147717 PMCID: PMC6083740 DOI: 10.1155/2018/4232706] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2018] [Revised: 05/23/2018] [Accepted: 06/04/2018] [Indexed: 01/08/2023] Open
Abstract
Serotonin (5-hydroxytryptamine; 5-HT) plays an important role in control of locomotion, partly through direct effects on motoneurons. Spinal cord complete transection (SCI) results in changes in 5-HT receptors on motoneurons that influence functional recovery. Activation of 5-HT2A and 5-HT7 receptors improves locomotor hindlimb movements in paraplegic rats. Here, we analyzed the mRNA of 5-HT2A and 5-HT7 receptors (encoded by Htr2a and Htr7 genes, resp.) in motoneurons innervating tibialis anterior (TA) and gastrocnemius lateralis (GM) hindlimb muscles and the tail extensor caudae medialis (ECM) muscle in intact as well as spinal rats. Moreover, the effect of intraspinal grafting of serotonergic neurons on Htr2a and Htr7 gene expression was examined to test the possibility that the graft origin 5-HT innervation in the spinal cord of paraplegic rats could reverse changes in gene expression induced by SCI. Our results indicate that SCI at the thoracic level leads to changes in Htr2a and Htr7 gene expression, whereas transplantation of embryonic serotonergic neurons modifies these changes in motoneurons innervating hindlimb muscles but not those innervating tail muscles. This suggests that the upregulation of genes critical for locomotor recovery, resulting in limb motoneuron plasticity, might account for the improved locomotion in grafted animals.
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