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Dudzińska E, Grabrucker AM, Kwiatkowski P, Sitarz R, Sienkiewicz M. The Importance of Visceral Hypersensitivity in Irritable Bowel Syndrome-Plant Metabolites in IBS Treatment. Pharmaceuticals (Basel) 2023; 16:1405. [PMID: 37895876 PMCID: PMC10609912 DOI: 10.3390/ph16101405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 09/28/2023] [Accepted: 10/02/2023] [Indexed: 10/29/2023] Open
Abstract
The visceral stimuli from the digestive tract are transmitted via afferent nerves through the spinal cord to the brain, where they are felt as pain. The overreaction observed in the brain of irritable bowel syndrome (IBS) patients may be due to increased peripheral sensitivity to stimuli from the gastrointestinal tract. Although the exact pathway is uncertain, attenuation of visceral hypersensitivity is still of interest in treating IBS. It has been shown that stress stimulates the sympathetic nervous system while inhibiting the vagus nerve (VN). In addition, stress factors lead to dysbiosis and chronic low-grade inflammation of the intestinal mucosa, which can lead to lower gastrointestinal visceral hypersensitivity. Therefore, an important goal in the treatment of IBS is the normalization of the intestinal microflora. An interesting option seems to be nutraceuticals, including Terminalia chebula, which has antibacterial and antimicrobial activity against various pathogenic Gram-positive and Gram-negative bacteria. Additionally, short-term transcutaneous vagus nerve stimulation can reduce the stress-induced increase in intestinal permeability, thereby reducing inflammation. The conducted studies also indicate a relationship between the stimulation of the vagus nerve (VN) and the activation of neuromodulatory networks in the central nervous system. Therefore, it seems reasonable to conclude that a two-way action through stimulating the VN and using nutraceuticals may become an effective therapy in treating IBS.
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Affiliation(s)
- Ewa Dudzińska
- Department of Dietetics and Nutrition Education, Medical University of Lublin, 20-093 Lublin, Poland
| | - Andreas M. Grabrucker
- Department of Biological Sciences, University of Limerick, V94 PH61 Limerick, Ireland;
- Bernal Institute, University of Limerick, V94 PH61 Limerick, Ireland
- Health Research Institute (HRI), University of Limerick, V94 PH61 Limerick, Ireland
| | - Paweł Kwiatkowski
- Department of Diagnostic Immunology, Pomeranian Medical University in Szczecin, Al. Powstancow Wlkp. 72, 70-111 Szczecin, Poland;
| | - Robert Sitarz
- Department of Human Anatomy, Medical University of Lublin, 20-090 Lublin, Poland;
- First Department of Surgical Oncology, St. John’s Cancer Center, 20-090 Lublin, Poland
| | - Monika Sienkiewicz
- Department of Pharmaceutical Microbiology and Microbiological Diagnostic, Medical University of Lodz, Muszynskiego 1, 90-151 Lodz, Poland;
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Johnson JC, Geesala R, Zhang K, Lin YM, M’Koma AE, Shi XZ. Smooth muscle dysfunction in the pre-inflammation site in stenotic Crohn's-like colitis: implication of mechanical stress in bowel dysfunction in gut inflammation. Front Physiol 2023; 14:1215900. [PMID: 37520831 PMCID: PMC10375711 DOI: 10.3389/fphys.2023.1215900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 07/06/2023] [Indexed: 08/01/2023] Open
Abstract
Background and Aims: Gut smooth muscle dysfunctions contribute to symptoms such as abdominal cramping, diarrhea, and constipation in inflammatory bowel disease (IBD). The mechanisms for muscle dysfunctions are incompletely understood. We tested the hypothesis that mechanical stress plays a role in muscle dysfunction in a rat model of Crohn's-like colitis where inflammatory stenosis leads to mechanical distention in the pre-inflammation site. Methods: Crohn's-like colitis was induced by intracolonic instillation of TNBS (65 mg/kg) in Sprague-Dawley rats. Control rats were instilled with saline. The rats were fed with either regular solid food or exclusively liquid diet. Rats were euthanized by day 7. Results: When rats were fed with solid food, TNBS treatment induced localized transmural inflammation with stenosis in the instillation site and marked distention with no inflammation in the pre-inflammation site of the colon. Smooth muscle contractility was suppressed, and expression of cyclo-oxygenase-2 (COX-2) and production of prostaglandin E2 (PGE2) were increased not only in the inflammation site but also in the pre-inflammation site. Liquid diet treatment, mimicking exclusive enteral nutrition, completely released mechanical distention, eliminated COX-2 expression and PGE2 production, and improved smooth muscle contractility especially in the pre-inflammation site. When rats were administered with COX-2 inhibitor NS-398 (5 mg/kg, i. p. daily), smooth muscle contractility was restored in the pre-inflammation site and significantly improved in the inflammation site. Conclusion: Colonic smooth muscle contractility is significantly impaired in stenotic Crohn's-like colitis rats not only in the inflammation site, but in the distended pre-inflammation site. Mechanical stress-induced expression of COX-2 plays a critical role in smooth muscle dysfunction in the pre-inflammation site in Crohn's-like colitis rats.
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Affiliation(s)
- John C. Johnson
- Department of Internal Medicine, University of Texas Medical Branch, Galveston, TX, United States
- John Sealy School of Medicine Class of 2025, University of Texas Medical Branch, Galveston, TX, United States
| | - Ramasatyaveni Geesala
- Department of Internal Medicine, University of Texas Medical Branch, Galveston, TX, United States
| | - Ke Zhang
- Department of Internal Medicine, University of Texas Medical Branch, Galveston, TX, United States
| | - You-Min Lin
- Department of Internal Medicine, University of Texas Medical Branch, Galveston, TX, United States
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, United States
| | - Amosy E. M’Koma
- Department of Biochemistry, Cancer Biology, Neuroscience and Pharmacology, Meharry Medical College School of Medicine, Nashville, TN, United States
| | - Xuan-Zheng Shi
- Department of Internal Medicine, University of Texas Medical Branch, Galveston, TX, United States
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Collatuzzo G, Boffetta P, Radaelli F, Cadoni S, Hassan C, Frazzoni L, Anderloni A, Laterza L, La Marca M, Rogai F, Binda C, Montale A, Soriani P, Fabbri C, Sacco M, Gallittu P, Mura D, Trovato C, Vitale G, Mussetto A, Musso A, Conti CB, Manno M, Repici A, Zagari RM, Farioli A, Fuccio L. Incidence, risk and protective factors of symptoms after colonoscopy. Dig Liver Dis 2022; 54:1698-1705. [PMID: 36154988 DOI: 10.1016/j.dld.2022.08.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 08/09/2022] [Accepted: 08/12/2022] [Indexed: 12/30/2022]
Abstract
BACKGROUND Few studies focused on minor adverse events which may develop after colonoscopy. AIMS To investigate the incidence and factors associated to post-colonoscopy symptoms. METHODS This is a prospective study conducted in 10 Italian hospitals. The main outcome was a cumulative score combining 10 gastrointestinal (GI) symptoms occurring the week following colonoscopy. The analyses were conducted via multivariate logistic regression. RESULTS Of 793 subjects included in the analysis, 361 (45.5%) complained the new onset of at least one GI symptom after the exam; one symptom was reported by 202 (25.5%), two or more symptoms by 159 (20.1%). Newly developed symptoms more frequently reported were epigastric/abdominal bloating (32.2%), pain (17.3%), and dyspeptic symptoms (17.9%). Symptoms were associated with female sex (odds ratio [OR]=2.54), increasing number of symptoms developed during bowel preparation intake (OR=1.35) and somatic symptoms (OR=1.27). An inverse association was observed with better mood (OR=0.74). A high-risk profile was identified, represented by women with bad mood and somatic symptoms (OR=8.81). CONCLUSION About half of the patients develop de novo GI symptoms following colonoscopy. Improving bowel preparation tolerability may reduce the incidence of post-colonoscopy symptoms, especially in more vulnerable patients.
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Affiliation(s)
- Giulia Collatuzzo
- Department of Medical and Surgical Sciences, University of Bologna, Bologna, Italy
| | - Paolo Boffetta
- Department of Medical and Surgical Sciences, University of Bologna, Bologna, Italy; Stony Brook Cancer Center, Stony Brook University, Stony Brook, NY, United States
| | | | - Sergio Cadoni
- Digestive Endoscopy Unit, Centro Traumatologico-Ortopedico Hospital, Iglesias, Italy
| | - Cesare Hassan
- Division of Gastroenterology and Digestive Endoscopy, Department of Gastroenterology, IRCCS Humanitas Research Hospital, via Manzoni 56, 20089 Rozzano, Milan, Italy; Department of Biomedical Sciences, Humanitas University, Via Rita Levi Montalcini 4, 20072 Pieve Emanuele, Milan, Italy
| | - Leonardo Frazzoni
- Department of Medical and Surgical Sciences, University of Bologna, Bologna, Italy; IRCCS Azienda Ospedaliero-Universitaria di Bologna, Department of Medical and Surgical Sciences, Gastroenterology Unit, University of Bologna, Bologna, Italy
| | - Andrea Anderloni
- Digestive Endoscopy Unit, Division of Gastroenterology, Humanitas Clinical and Research Center, Milan, Italy
| | - Liboria Laterza
- Department of Medical and Surgical Sciences, University of Bologna, Bologna, Italy; Endoscopy Service, AUSL Reggio Emilia, Reggio Emilia, Italy
| | - Marina La Marca
- Department of Medical and Surgical Sciences, University of Bologna, Bologna, Italy; IRCCS Azienda Ospedaliero-Universitaria di Bologna, Department of Medical and Surgical Sciences, Gastroenterology Unit, University of Bologna, Bologna, Italy
| | - Francesca Rogai
- IBD Unit, Gastroenterology Department, Careggi Hospital, University of Florence, Viale San Luca, 50134, Florence, Italy
| | - Cecilia Binda
- Unit of Gastroenterology and Digestive Endoscopy, Forli-Cesena Hospital, AUSL Romagna, Forli-Cesena, Italy
| | - Amedeo Montale
- IRCCS Azienda Ospedaliero-Universitaria di Bologna, Department of Medical and Surgical Sciences, Gastroenterology Unit, University of Bologna, Bologna, Italy
| | - Paola Soriani
- UOSD Gastroenterologia ed Endoscopia Digestiva, Azienda USL di Modena, Italy
| | - Carlo Fabbri
- Unit of Gastroenterology and Digestive Endoscopy, Forli-Cesena Hospital, AUSL Romagna, Forli-Cesena, Italy
| | - Marco Sacco
- Città della Salute e della Scienza, Turin, Italy
| | - Paolo Gallittu
- Digestive Endoscopy Unit, Centro Traumatologico-Ortopedico Hospital, Iglesias, Italy
| | - Donatella Mura
- Digestive Endoscopy Unit, Centro Traumatologico-Ortopedico Hospital, Iglesias, Italy
| | - Cristina Trovato
- Division of Endoscopy, Istituto di Ricovero e Cura a Carattere Scientifico, European Institute of Oncology, Milan, Italy
| | | | | | | | - Clara Benedetta Conti
- Gastroenterology Unit, Valduce Hospital, Como, Italy; Interventional Endoscopy ASST Monza, Monza, Italy
| | - Mauro Manno
- UOSD Gastroenterologia ed Endoscopia Digestiva, Azienda USL di Modena, Italy
| | - Alessandro Repici
- Division of Gastroenterology and Digestive Endoscopy, Department of Gastroenterology, IRCCS Humanitas Research Hospital, via Manzoni 56, 20089 Rozzano, Milan, Italy; Department of Biomedical Sciences, Humanitas University, Via Rita Levi Montalcini 4, 20072 Pieve Emanuele, Milan, Italy
| | - Rocco Maurizio Zagari
- Department of Medical and Surgical Sciences, University of Bologna, Bologna, Italy; IRCCS Azienda Ospedaliero-Universitaria di Bologna, Department of Medical and Surgical Sciences, Gastroenterology Unit, University of Bologna, Bologna, Italy
| | - Andrea Farioli
- Department of Medical and Surgical Sciences, University of Bologna, Bologna, Italy
| | - Lorenzo Fuccio
- Department of Medical and Surgical Sciences, University of Bologna, Bologna, Italy; IRCCS Azienda Ospedaliero-Universitaria di Bologna, Department of Medical and Surgical Sciences, Gastroenterology Unit, University of Bologna, Bologna, Italy.
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Geesala R, Lin YM, Zhang K, Shi XZ. Targeting Mechano-Transcription Process as Therapeutic Intervention in Gastrointestinal Disorders. Front Pharmacol 2021; 12:809350. [PMID: 34992543 PMCID: PMC8724579 DOI: 10.3389/fphar.2021.809350] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 12/06/2021] [Indexed: 12/16/2022] Open
Abstract
Mechano-transcription is a process whereby mechanical stress alters gene expression. The gastrointestinal (GI) tract is composed of a series of hollow organs, often encountered by transient or persistent mechanical stress. Recent studies have revealed that persistent mechanical stress is present in obstructive, functional, and inflammatory disorders and alters gene transcription in these conditions. Mechano-transcription of inflammatory molecules, pain mediators, pro-fibrotic and growth factors has been shown to play a key role in the development of motility dysfunction, visceral hypersensitivity, inflammation, and fibrosis in the gut. In particular, mechanical stress-induced cyclooxygenase-2 (COX-2) and certain pro-inflammatory mediators in gut smooth muscle cells are responsible for motility dysfunction and inflammatory process. Mechano-transcription of pain mediators such as nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) may lead to visceral hypersensitivity. Emerging evidence suggests that mechanical stress in the gut also leads to up-regulation of certain proliferative and pro-fibrotic mediators such as connective tissue growth factor (CTGF) and osteopontin (OPN), which may contribute to fibrostenotic Crohn's disease. In this review, we will discuss the pathophysiological significance of mechanical stress-induced expression of pro-inflammatory molecules, pain mediators, pro-fibrotic and growth factors in obstructive, inflammatory, and functional bowel disorders. We will also evaluate potential therapeutic targets of mechano-transcription process for the management of these disorders.
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5
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Lin YM, Tang Y, Fu Y, Hegde S, Shi DW, Huang LYM, Shi XZ. An opioid receptor-independent mechanism underlies motility dysfunction and visceral hyperalgesia in opioid-induced bowel dysfunction. Am J Physiol Gastrointest Liver Physiol 2021; 320:G1093-G1104. [PMID: 33908261 PMCID: PMC8285582 DOI: 10.1152/ajpgi.00400.2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Constipation and abdominal pain are commonly encountered in opioid-induced bowel dysfunction (OBD). The underlying mechanisms are incompletely understood, and treatments are not satisfactory. As patients with OBD often have fecal retention, we aimed to determine whether fecal retention plays a pathogenic role in the development of constipation and abdominal pain in OBD, and if so to investigate the mechanisms. A rodent model of OBD was established by daily morphine treatment at 10 mg/kg for 7 days. Bowel movements, colonic muscle contractility, visceromotor response to colorectal distention, and cell excitability of colon-projecting dorsal root ganglion neurons were determined in rats fed with normal pellet food, or with clear liquid diet. Morphine treatment (Mor) reduced fecal outputs starting on day 1, and caused fecal retention afterward. Compared with controls, Mor rats demonstrated suppressed muscle contractility, increased neuronal excitability, and visceral hypersensitivity. Expression of cyclooxygenase-2 (COX-2) and nerve growth factor (NGF) was upregulated in the smooth muscle of the distended colon in Mor rats. However, prevention of fecal retention by feeding rats with clear liquid diet blocked upregulation of COX-2 and NGF, restored muscle contractility, and attenuated visceral hypersensitivity in Mor rats. Moreover, inhibition of COX-2 improved smooth muscle function and fecal outputs, whereas anti-NGF antibody administration attenuated visceral hypersensitivity in Mor rats. Morphine-induced fecal retention is an independent pathogenic factor for motility dysfunction and visceral hypersensitivity in rats with OBD. Liquid diet may have therapeutic potential for OBD by preventing fecal retention-induced mechanotranscription of COX-2 and NGF.NEW & NOTEWORTHY Our preclinical study shows that fecal retention is a pathogenic factor in opioid-induced bowel dysfunction, as prevention of fecal retention with liquid diet improved motility and attenuated visceral hyperalgesia in morphine-treated animals by blocking expression of cyclooxygenase-2 and nerve growth factor in the colon.
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Affiliation(s)
- You-Min Lin
- 1Department of Internal Medicine, The University of Texas
Medical Branch, Galveston, Texas
| | - Yanbo Tang
- 1Department of Internal Medicine, The University of Texas
Medical Branch, Galveston, Texas,2Department of Gastroenterology, The First Affiliated Hospital, Guangxi University of Science and Technology, Guangxi, China
| | - Yu Fu
- 1Department of Internal Medicine, The University of Texas
Medical Branch, Galveston, Texas
| | - Shrilakshmi Hegde
- 1Department of Internal Medicine, The University of Texas
Medical Branch, Galveston, Texas
| | - Daniel W. Shi
- 1Department of Internal Medicine, The University of Texas
Medical Branch, Galveston, Texas,3College of Science, Texas A&M University, College Station, Texas
| | - Li-Yen M. Huang
- 4Department of Neuroscience and Cell Biology, The University of Texas Medical Branch, Galveston, Texas
| | - Xuan-Zheng Shi
- 1Department of Internal Medicine, The University of Texas
Medical Branch, Galveston, Texas
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6
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Tian YM, He HL, Cheng YT, Yi L, Yang Y, Yang P. A Combined Phytochemical and Network Pharmacology Approach to Reveal the Effective Substances and Mechanism of Eomecon chionantha Hance for the Treatment of Ulcerative Colitis. Nat Prod Commun 2021. [DOI: 10.1177/1934578x21992966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Eomecon chionantha Hance (ECH), a traditional Chinese herbal medicine, has been reported for the treatment of traumatic injuries and colitis. The current treatments for ulcerative colitis (UC) are unstable and have side effects, so ECH is potentially useful for treating this condition. However, the active ingredients and pharmacological mechanisms of ECH in treating UC remain unclear. In this study, 21 alkaloids were extracted and purified from the roots of ECH, among which 13 were extracted from this herb for the first time. Our results showed that 12 ingredients may have effective pharmacological effects after absorption, distribution, metabolism, and excretion (ADME) screening. Network pharmacological analysis revealed that the active ingredients may have positive effects on 19 significant signaling pathways, such as on small cell lung cancer, serotonergic synapses, the IL-17 signaling pathway, Th17 cell differentiation, the estrogen signaling pathway, transcriptional misregulation in cancer, the PI3K-Akt signaling pathway, and others by targeting 23 proteins, including MAPK14, RXRA, GSK3B, CDK2, RXRB, HSP90AA1, PTGS2, and ESR1. It is of great benefit to use separation, purification, and network pharmacology together to screen active natural products. This study indicated potential anti-UC mechanisms of the active ingredients of ECH and provides theoretical support for the treatment of UC using ECH.
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Affiliation(s)
- Yu-mei Tian
- Hunan Province Key Laboratory for Antibody-based Drug and Intelligent Delivery System, School of Pharmaceutical Sciences, School of Nursing, Hunan University of Medicine, Huaihua 418000, China
| | - Hai-lang He
- Hunan Province Key Laboratory for Antibody-based Drug and Intelligent Delivery System, School of Pharmaceutical Sciences, School of Nursing, Hunan University of Medicine, Huaihua 418000, China
| | - Ya-ting Cheng
- Hunan Province Key Laboratory for Antibody-based Drug and Intelligent Delivery System, School of Pharmaceutical Sciences, School of Nursing, Hunan University of Medicine, Huaihua 418000, China
| | - Li Yi
- Hunan Province Key Laboratory for Antibody-based Drug and Intelligent Delivery System, School of Pharmaceutical Sciences, School of Nursing, Hunan University of Medicine, Huaihua 418000, China
| | - Yuan Yang
- Hunan Province Key Laboratory for Antibody-based Drug and Intelligent Delivery System, School of Pharmaceutical Sciences, School of Nursing, Hunan University of Medicine, Huaihua 418000, China
- Dong Medicine Key Laboratory of Hunan Province, Department of Laboratory Medicine, Hunan University of Medicine, Huaihua 418000, China
- Hunan Provincial Key Laboratory for Synthetic Biology of Traditional Chinese Medicine, Hunan University of Medicine, Huaihua 418000, China
| | - Peng Yang
- Hunan Province Key Laboratory for Antibody-based Drug and Intelligent Delivery System, School of Pharmaceutical Sciences, School of Nursing, Hunan University of Medicine, Huaihua 418000, China
- Hunan Provincial Key Laboratory for Synthetic Biology of Traditional Chinese Medicine, Hunan University of Medicine, Huaihua 418000, China
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7
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Hegde S, Lin YM, Fu Y, Savidge T, Shi XZ. Precision Lactobacillus reuteri therapy attenuates luminal distension-associated visceral hypersensitivity by inducing peripheral opioid receptors in the colon. Pain 2020; 161:2737-2749. [PMID: 32569084 PMCID: PMC7669621 DOI: 10.1097/j.pain.0000000000001967] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Luminal distension and abdominal pain are major clinical hallmarks of obstructive bowel disorders and functional bowel disorders linked to gut dysbiosis. Our recent studies found that chronic lumen distension increased visceral sensitivity and decreased abundance of gut commensal Lactobacillus reuteri in a rodent model of partial colon obstruction (OB). To establish causation, we performed precision microbial therapy to assess whether recolonization of L. reuteri prevents visceral hypersensitivity in lumen distension, and if so, to identify the gut-microbiota mechanism. Lumen distension was induced in Sprague-Dawley rats by implanting an OB band in the distal colon for up to 7 days. L. reuteri strains or vehicle were gavage ingested 1 × 10 colony-forming units/g daily starting 2 days before OB. L. reuteri rat strains that were able to recolonize obstructed colon significantly improved food intake and body weight in OB rats, and attenuated referred visceral hyperalgesia measured by the withdrawal response to von Frey filament applications to the abdomen. Mechanistically, L. reuteri treatment attenuated hyperexcitability of the dorsal root ganglia neurons projecting to the distended colon by promoting opioid receptor function in affected tissues. The expression of µ, δ, and κ opioid receptors was significantly downregulated in colonic muscularis externae and sensory neurons in OB rats. However, L. reuteri treatment prevented the loss of opioid receptors. Furthermore, administration of peripheral opioid receptor antagonist naloxone methiodide abolished the analgesic effect of L. reuteri in OB. In conclusion, precision L. reuteri therapy prevents lumen distension-associated visceral hypersensitivity by local bacterial induction of opioid receptors.
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Affiliation(s)
- Shrilakshmi Hegde
- Dept. of Internal Medicine, University of Texas Medical Branch, Galveston, TX, USA
| | - You-Min Lin
- Dept. of Internal Medicine, University of Texas Medical Branch, Galveston, TX, USA
| | - Yu Fu
- Dept. of Internal Medicine, University of Texas Medical Branch, Galveston, TX, USA
| | - Tor Savidge
- Dept. of Pathology & Immunology, Baylor College of Medicine, Houston, TX, USA
| | - Xuan-Zheng Shi
- Dept. of Internal Medicine, University of Texas Medical Branch, Galveston, TX, USA
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8
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Grossi V, Hyams JS, Glidden NC, Knight BE, Young EE. Characterizing Clinical Features and Creating a Gene Expression Profile Associated With Pain Burden in Children With Inflammatory Bowel Disease. Inflamm Bowel Dis 2020; 26:1283-1290. [PMID: 31627210 DOI: 10.1093/ibd/izz240] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Indexed: 12/13/2022]
Abstract
BACKGROUND There is often dissociation between inflammatory activity and abdominal pain in children with inflammatory bowel disease (IBD), suggesting other factors may play a role in the pain experience. METHODS Patients (8 to 17 years) newly diagnosed with IBD were enrolled in the ALLAY Study: Assessing Risk Factors for Abdominal Pain in Children with Inflammatory Bowel Disease (NCT02984059). At diagnostic colonoscopy, 3 rectal biopsies were collected, and gene expression analysis was performed using Qiagen RT2 Profiler Neuropathic and Inflammatory Pain PCR Array. Relative fold difference in gene expression for 84 pain-associated genes was calculated using the 2-ΔΔ Cq method compared with pain-free controls. Factors affecting pain burden (Pain Burden Interview; PBI) were analyzed, including age, sex, rectal inflammation, and gene expression. Data were analyzed using multiple stepwise linear regression and 2-tailed t tests (P ≤ 0.05). RESULTS Thirty-nine newly diagnosed IBD patients were included (65% male, mean age 12.75 years [SD 2.63], 23 Crohn's disease, 16 ulcerative colitis), along with 3 controls. Mean PBI score was 7.73 (SD 6.4, range 0 to 23) for all patients. Age and sex were not predictive of pain burden, but disease activity score was (P = 0.03). Expression of TRPV3, OPRM1, P2X3, SCN9A, PTGS2, and MAPK14 were associated with PBI score. Subsequent 2-tailed t tests comparing patients with no pain (PBI score ≦ 2, N = 11) to those with pain (PBI > 2, N = 28) confirmed differential expression of TRPV3, PTGS2, and MAPK14 was in patients with pain (all P < 0.05). CONCLUSION Pain burden in newly diagnosed IBD patients may be linked to TRPV3, PTGS2, and MAPK14 expression, suggesting potential therapeutic targets for managing pain in IBD.
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Affiliation(s)
- Victoria Grossi
- Division of Digestive Diseases, Hepatology, and Nutrition, Connecticut Children's Medical Center, Hartford, Connecticut, USA.,Department of Pediatrics, University of Connecticut School of Medicine, Farmington, Connecticut, USA
| | - Jeffrey S Hyams
- Division of Digestive Diseases, Hepatology, and Nutrition, Connecticut Children's Medical Center, Hartford, Connecticut, USA.,Department of Pediatrics, University of Connecticut School of Medicine, Farmington, Connecticut, USA
| | - Nicole C Glidden
- Genetics and Genome Sciences, University of Connecticut School of Medicine, Farmington, Connecticut, USA
| | - Brittany E Knight
- Department of Neuroscience, University of Connecticut School of Medicine, Farmington, Connecticut, USA
| | - Erin E Young
- Department of Anesthesiology, University of Kansas School of Medicine, Kansas City, Kansas, USA
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Calcium Pyruvate Exerts Beneficial Effects in an Experimental Model of Irritable Bowel Disease Induced by DCA in Rats. Nutrients 2019; 11:nu11010140. [PMID: 30634696 PMCID: PMC6356508 DOI: 10.3390/nu11010140] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Revised: 01/05/2019] [Accepted: 01/08/2019] [Indexed: 12/12/2022] Open
Abstract
Pyruvate is a normal constituent of the body that participates in carbohydrate metabolism and functions as a scavenger of free radicals. Calcium pyruvate monohydrate (CPM) is a more stable derivative that has proved its anti-inflammatory effect in experimental colitis, among other disorders, and that could also be considered a source of calcium. Thus, it would be useful for the treatment of diseases with an inflammatory component and a high prevalence of osteoporosis like the irritable bowel syndrome (IBS). The aim of the present study is to evaluate the effects of CPM in a rat model of chronic post-inflammatory visceral pain induced by deoxycholic acid (DCA) that resembles IBS. Rats were administered DCA for three days intracolonically and then treated daily with CPM (40 and 100 mg/kg) or gabapentin (70 mg/kg) (positive control) by oral gavage for 17 days. The treatments reduced the visceral hypersensitivity measured by response to colorectal distension and referred pain. DCA induced changes in the colonic immune response characterized by increased expression of the cytokine Il-1β and the inducible enzyme Cox-2, which was reduced by the treatments. DCA also decreased the gut expression of the mucins Muc-2 and Muc-3, which was normalized by CPM, whereas gabapentin only increased significantly Muc-3. Moreover, DCA increased the expression of Tlr3, which was decreased to basal levels by all the treatments. However, the serotonin receptor Htr-4, which was also elevated, was not affected by any of the treatments, indicating no effect through this signalling pathway. In conclusion, CPM ameliorated the visceral hypersensitivity and the referred pain caused by DCA, being as effective as the control drug. Furthermore, it improved the immune status of the animals, which could contribute to the visceral analgesia and the regeneration of the intestinal epithelial barrier integrity.
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Fu Y, Lin YM, Winston JH, Radhakrishnan R, Huang LYM, Shi XZ. Role of brain-derived neurotrophic factor in the pathogenesis of distention-associated abdominal pain in bowel obstruction. Neurogastroenterol Motil 2018; 30:e13373. [PMID: 29781158 PMCID: PMC6160336 DOI: 10.1111/nmo.13373] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Accepted: 04/10/2018] [Indexed: 02/08/2023]
Abstract
BACKGROUND Previous studies found that visceral sensitivity is increased in bowel obstruction (BO). We hypothesized that mechanical stress-induced expression of BDNF in smooth muscle cells (SMC) of the distended bowel plays a critical role in visceral hypersensitivity in BO by altering voltage-gated K+ channel (Kv ) activity in sensory neurons. METHODS Partial colon obstruction was maintained in rats for 7 days. Colon-projecting neurons in the dorsal root ganglia (DRG, T13 to L2) were isolated for electrophysiological and gene expression studies. KEY RESULTS Compared to controls, membrane excitability of colon-projecting DRG neurons was markedly enhanced in BO. The densities of total Kv and transient A-type (IA ) K+ currents, but not sustained delayed IK current, were significantly reduced in the neurons in BO. The mRNA expression of IA subtype Kv 1.4 in colon neurons was down-regulated in BO. Expression of BDNF mRNA and protein was dramatically increased in colonic smooth muscle of the distended segment, but not in the non-distended aboral segment. Mechanical stretch of colon SMC in vitro increased BDNF expression. Treatment with anti-BDNF antibody restored total Kv and IA currents of neurons from BO rats. Administration of Trk B inhibitor ANA-12 blocked BO-associated changes of neuronal excitability, Kv activity and gene expression in obstruction. CONCLUSIONS AND INFERENCES Mechanical stress-induced expression of BDNF in colon SMC plays a critical role in visceral hypersensitivity in BO by suppressing A-type K+ currents and gene expression in sensory nerve. These findings help to identify therapeutic targets for distention-associated abdominal pain in the gut.
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Affiliation(s)
- Yu Fu
- Dept. of Internal Medicine, University of Texas Medical Branch, Galveston, TX, USA
| | - You-Min Lin
- Dept. of Internal Medicine, University of Texas Medical Branch, Galveston, TX, USA
| | - John H. Winston
- Dept. of Internal Medicine, University of Texas Medical Branch, Galveston, TX, USA
| | - Ravi Radhakrishnan
- Dept. of Surgery, University of Texas Medical Branch, Galveston, TX, USA
| | - Li-Yen M. Huang
- Dept. of Neuroscience & Cell Biology, University of Texas Medical Branch, Galveston, TX, USA
| | - Xuan-Zheng Shi
- Dept. of Internal Medicine, University of Texas Medical Branch, Galveston, TX, USA,Address for communication: Dr. Xuan-Zheng Shi, Department of Internal Medicine, Division of Gastroenterology, The University of Texas Medical Branch, 301 University Boulevard, 4.106 Basic Science Building, Galveston, TX 77555-0655, Phone: (409) 772-0940, FAX: (409) 747-3084,
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11
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Lin YM, Fu Y, Hegde S, Tang Y, Radhakrishnan R, Shi XZ. Microsomal Prostaglandin E Synthase-1 Plays a Critical Role in Long-term Motility Dysfunction after Bowel Obstruction. Sci Rep 2018; 8:8831. [PMID: 29891860 PMCID: PMC5995953 DOI: 10.1038/s41598-018-27230-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Accepted: 05/24/2018] [Indexed: 12/20/2022] Open
Abstract
Motility dysfunction is present not only during bowel obstruction (BO), but after obstruction is resolved. Previous studies found that lumen distension associated mechano-transcription of COX-2 and production of PGE2 in gut smooth muscle cells (SMC) account for motility dysfunction during obstruction. We hypothesized that PGE2 may exert autocrine effect in SMC to induce microsomal prostaglandin E synthase-1 (mPGES-1), which contributes to motility dysfunction after obstruction is resolved. Partial colon obstruction was induced in rats with an obstruction band, which was released 7 days later. Rats were further studied in the post-BO state. Circular muscle contractility of the mid colon (previously distended during obstruction) remained suppressed, and colon transit was impaired in the post-BO state. The COX-2, mPGES-1, and PGE2 levels were all increased in the distended bowel during obstruction. However, after obstruction was resolved, COX-2 expression returned to normal, whereas mPGES-1 and PGE2 levels remained increased. Expression of mPGES-1 in colon SMC was inducible by stretch or PGE2. Administration of mPGES-1 inhibitor Cay 10526 either before or after the release of obstruction normalized PGE2 levels and improved motility in the post-BO rats. In conclusion, mPGES-1 plays a critical role in the continuous suppression of motor function in the post-BO state.
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Affiliation(s)
- You-Min Lin
- Department of Internal Medicine, University of Texas Medical Branch, Galveston, TX, USA
| | - Yu Fu
- Department of Internal Medicine, University of Texas Medical Branch, Galveston, TX, USA
| | - Shrilakshmi Hegde
- Department of Internal Medicine, University of Texas Medical Branch, Galveston, TX, USA
| | - Yanbo Tang
- Department of Internal Medicine, University of Texas Medical Branch, Galveston, TX, USA.,Department of Gastroenterology, The first Affiliated Hospital, Guangxi University of Science and Technology, Liuzhou, Guangxi, China
| | - Ravi Radhakrishnan
- Department of Surgery, University of Texas Medical Branch, Galveston, TX, USA
| | - Xuan-Zheng Shi
- Department of Internal Medicine, University of Texas Medical Branch, Galveston, TX, USA.
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12
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Shi XZ, Lin YM, Hegde S. Novel Insights Into the Mechanisms of Abdominal Pain in Obstructive Bowel Disorders. Front Integr Neurosci 2018; 12:23. [PMID: 29937720 PMCID: PMC6002527 DOI: 10.3389/fnint.2018.00023] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 05/22/2018] [Indexed: 12/27/2022] Open
Abstract
Obstructive bowel disorders (OBD) are characterized by lumen distention due to mechanical or functional obstruction in the gut. Abdominal pain is one of the main symptoms in OBD. In this article, we aim to critically review the potential mechanisms for acute and chronic pain in bowel obstruction (BO). While clustered contractions and associated increase of intraluminal pressure may account for colicky pain in simple obstruction, ischemia may be involved in acute pain in severe conditions such as closed loop obstruction. Recent preclinical studies discovered that visceral sensitivity is increased in BO, and visceral hypersensitivity may underlie the mechanisms of chronic abdominal pain in BO. Mounting evidence suggests that lumen distension, as a circumferential mechanical stretch, alters gene expression (mechano-transcription) in the distended bowel, and mechano-transcription of nociceptive and inflammatory mediators plays a critical role in the development of visceral hypersensitivity in BO. Mechano-transcription of nerve growth factor (NGF) in gut smooth muscle cells is found to increase voltage-gated Na+ channel (Nav) activity of the primary sensory neurons by up-regulating expression of TTX-resistant Nav1.8, whereas mechanical stretch-induced brain-derived neurotrophic factor (BDNF) reduces Kv currents especially A-type (IA) currents by down-regulating expression of specific IA subtypes such as Kv1.4. The NGF and BDNF mediated changes in gene expression and channel functions in the primary sensory neurons may constitute the main mechanisms of visceral hypersensitivity in OBD. In addition, mechanical stretch-induced COX-2 and other inflammatory mediators in the gut may also contribute to abdominal pain by activating and sensitizing nociceptors.
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Affiliation(s)
- Xuan-Zheng Shi
- Department of Internal Medicine, University of Texas Medical Branch, Galveston, TX, United States
| | - You-Min Lin
- Department of Internal Medicine, University of Texas Medical Branch, Galveston, TX, United States
| | - Shrilakshmi Hegde
- Department of Internal Medicine, University of Texas Medical Branch, Galveston, TX, United States
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13
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Shi XZ. Mechanical Regulation of Gene Expression in Gut Smooth Muscle Cells. Front Physiol 2017; 8:1000. [PMID: 29259559 PMCID: PMC5723328 DOI: 10.3389/fphys.2017.01000] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 11/20/2017] [Indexed: 12/15/2022] Open
Abstract
Intraluminal contents and their movement along the gastrointestinal tract create shear stress and mechanical stretch on the gut wall. While the shear stress is important in the initiation of immediate physiological responses, the circumferential mechanical stretch, such as that in obstructive bowel disorders, exerts long-lasting impacts on bowel functions by mainly affecting the deeper muscularis externae. Recent studies demonstrate that mechanical stretch alters gene transcription in gut smooth muscle cells (SMC), and the stretch-altered gene expression (mechano-transcription) may play a critical role in pathogenesis of motility dysfunction and abdominal pain in obstruction. Specifically, stretch-induced cyclo-oxygenase-2 and other pro-inflammatory mediators in gut SMC account for impairments of muscle contractility. Mechano-transcription of pain mediators such as nerve growth factor may contribute to visceral hypersensitivity, by sensitizing primary sensory neurons. This review aims to highlight the novel findings of mechano-transcription in the gut, and to discuss the signaling mechanisms and pathophysiological significance of mechano-transcription.
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Affiliation(s)
- Xuan-Zheng Shi
- Department of Internal Medicine, University of Texas Medical Branch, Galveston, TX, United States
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14
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Lin YM, Fu Y, Winston J, Radhakrishnan R, Sarna SK, Huang LYM, Shi XZ. Pathogenesis of abdominal pain in bowel obstruction: role of mechanical stress-induced upregulation of nerve growth factor in gut smooth muscle cells. Pain 2017; 158:583-592. [PMID: 28079757 PMCID: PMC5354958 DOI: 10.1097/j.pain.0000000000000797] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Abdominal pain is one of the major symptoms in bowel obstruction (BO); its cellular mechanisms remain incompletely understood. We tested the hypothesis that mechanical stress in obstruction upregulates expression of nociception mediator nerve growth factor (NGF) in gut smooth muscle cells (SMCs), and NGF sensitizes primary sensory nerve to contribute to pain in BO. Partial colon obstruction was induced with a silicon band implanted in the distal bowel of Sprague-Dawley rats. Colon-projecting sensory neurons in the dorsal root ganglia (T13 to L2) were identified for patch-clamp and gene expression studies. Referred visceral sensitivity was assessed by measuring withdrawal response to stimulation by von Frey filaments in the lower abdomen. Membrane excitability of colon-projecting dorsal root ganglia neurons was significantly enhanced, and the withdrawal response to von Frey filament stimulation markedly increased in BO rats. The expression of NGF mRNA and protein was increased in a time-dependent manner (day 1-day 7) in colonic SMC but not in mucosa/submucosa of the obstructed colon. Mechanical stretch in vitro caused robust NGF mRNA and protein expression in colonic SMC. Treatment with anti-NGF antibody attenuated colon neuron hyperexcitability and referred hypersensitivity in BO rats. Obstruction led to significant increases of tetrodotoxin-resistant Na currents and mRNA expression of Nav1.8 but not Nav1.6 and Nav1.7 in colon neurons; these changes were abolished by anti-NGF treatment. In conclusion, mechanical stress-induced upregulation of NGF in colon SMC underlies the visceral hypersensitivity in BO through increased gene expression and activity of tetrodotoxin-resistant Na channels in sensory neurons.
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Affiliation(s)
- You-Min Lin
- Dept. of Internal Medicine, University of Texas Medical Branch, Galveston, TX, USA
| | - Yu Fu
- Dept. of Internal Medicine, University of Texas Medical Branch, Galveston, TX, USA
| | - John Winston
- Dept. of Internal Medicine, University of Texas Medical Branch, Galveston, TX, USA
| | - Ravi Radhakrishnan
- Dept. of Surgery, University of Texas Medical Branch, Galveston, TX, USA
| | - Sushil K. Sarna
- Dept. of Internal Medicine, University of Texas Medical Branch, Galveston, TX, USA
| | - Li-Yen M. Huang
- Dept. of Neuroscience & Cell Biology, University of Texas Medical Branch, Galveston, TX, USA
| | - Xuan-Zheng Shi
- Dept. of Internal Medicine, University of Texas Medical Branch, Galveston, TX, USA
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15
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Role of BK Ca in Stretch-Induced Relaxation of Colonic Smooth Muscle. BIOMED RESEARCH INTERNATIONAL 2016; 2016:9497041. [PMID: 28018918 PMCID: PMC5149602 DOI: 10.1155/2016/9497041] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 09/30/2016] [Accepted: 10/23/2016] [Indexed: 12/15/2022]
Abstract
Stretch-induced relaxation has not been clearly identified in gastrointestinal tract. The present study is to explore the role of large conductance calcium-activated potassium channels (BKCa) in stretch-induced relaxation of colon. The expression and currents of BKCa were detected and the basal muscle tone and contraction amplitude of colonic smooth muscle strips were measured. The expression of BKCa in colon is higher than other GI segments (P < 0.05). The density of BKCa currents was very high in colonic smooth muscle cells (SMCs). BKCa in rat colonic SMCs were sensitive to stretch. The relaxation response of colonic SM strips to stretch was attenuated by charybdotoxin (ChTX), a nonspecific BKCa blocker (P < 0.05). After blocking enteric nervous activities by tetrodotoxin (TTX), the stretch-induced relaxation did not change (P > 0.05). Still, ChTX and iberiotoxin (IbTX, a specific BKCa blocker) attenuated the relaxation of the colonic muscle strips enduring stretch (P < 0.05). These results suggest stretch-activation of BKCa in SMCs was involved in the stretch-induced relaxation of colon. Our study highlights the role of mechanosensitive ion channels in SMCs in colon motility regulation and their physiological and pathophysiological significance is worth further study.
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16
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Zhang YB, Guo ZD, Li MY, Fong P, Zhang JG, Zhang CW, Gong KR, Yang MF, Niu JZ, Ji XM, Lv GW. Gabapentin Effects on PKC-ERK1/2 Signaling in the Spinal Cord of Rats with Formalin-Induced Visceral Inflammatory Pain. PLoS One 2015; 10:e0141142. [PMID: 26512901 PMCID: PMC4626203 DOI: 10.1371/journal.pone.0141142] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Accepted: 10/05/2015] [Indexed: 11/19/2022] Open
Abstract
Currently, the clinical management of visceral pain remains unsatisfactory for many patients suffering from this disease. While preliminary animal studies have suggested the effectiveness of gabapentin in successfully treating visceral pain, the mechanism underlying its analgesic effect remains unclear. Evidence from other studies has demonstrated the involvement of protein kinase C (PKC) and extracellular signal-regulated kinase1/2 (ERK1/2) in the pathogenesis of visceral inflammatory pain. In this study, we tested the hypothesis that gabapentin produces analgesia for visceral inflammatory pain through its inhibitory effect on the PKC-ERK1/2 signaling pathway. Intracolonic injections of formalin were performed in rats to produce colitis pain. Our results showed that visceral pain behaviors in these rats decreased after intraperitoneal injection of gabapentin. These behaviors were also reduced by intrathecal injections of the PKC inhibitor, H-7, and the ERK1/2 inhibitor, PD98059. Neuronal firing of wide dynamic range neurons in L6–S1 of the rat spinal cord dorsal horn were significantly increased after intracolonic injection of formalin. This increased firing rate was inhibited by intraperitoneal injection of gabapentin and both the individual and combined intrathecal application of H-7 and PD98059. Western blot analysis also revealed that PKC membrane translocation and ERK1/2 phosphorylation increased significantly following formalin injection, confirming the recruitment of PKC and ERK1/2 during visceral inflammatory pain. These effects were also significantly reduced by intraperitoneal injection of gabapentin. Therefore, we concluded that the analgesic effect of gabapentin on visceral inflammatory pain is mediated through suppression of PKC and ERK1/2 signaling pathways. Furthermore, we found that the PKC inhibitor, H-7, significantly diminished ERK1/2 phosphorylation levels, implicating the involvement of PKC and ERK1/2 in the same signaling pathway. Thus, our results suggest a novel mechanism of gabapentin-mediated analgesia for visceral inflammatory pain through a PKC-ERK1/2 signaling pathway that may be a future therapeutic target for the treatment of visceral inflammatory pain.
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Affiliation(s)
- Yan-bo Zhang
- Department of Neurology, Affiliated Hospital of Taishan Medical University, Taian, China
- * E-mail:
| | - Zheng-dong Guo
- Department of Endocrinology, Affiliated Hospital of Taishan Medical University, Taian, China
| | - Mei-yi Li
- Department of Neurology, Shandong Taishan Chronic Disease Hospital, Taian, China
| | - Peter Fong
- Department of Neurology, University of California San Francisco, San Francisco, CA, United States of America
| | - Ji-guo Zhang
- Department of Pharmacology, College of Pharmacy, Taishan Medical University, Taian, China
| | - Can-wen Zhang
- Department of Neurology, Affiliated Hospital of Taishan Medical University, Taian, China
| | - Ke-rui Gong
- Department of Oral and Maxillofacial Surgery, University of California San Francisco, San Francisco, CA, United States of America
| | - Ming-feng Yang
- Department of Neurology, Affiliated Hospital of Taishan Medical University, Taian, China
| | - Jing-zhong Niu
- Department of Neurology, Affiliated Hospital of Taishan Medical University, Taian, China
| | - Xun-ming Ji
- Hypoxia Medical Institute, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Guo-wei Lv
- Hypoxia Medical Institute, Xuanwu Hospital, Capital Medical University, Beijing, China
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