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Reis C, Chambel S, Ferreira A, Cruz CD. Involvement of nerve growth factor (NGF) in chronic neuropathic pain - a systematic review. Rev Neurosci 2023; 34:75-84. [PMID: 35792932 DOI: 10.1515/revneuro-2022-0037] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 06/03/2022] [Indexed: 01/11/2023]
Abstract
Pain is a complex experience, encompassing physiological and psychological components. Amongst the different types of pain, neuropathic pain, resulting from injuries to the peripheral or central nervous system, still constitutes a challenge for researchers and clinicians. Nerve growth factor (NGF) is currently regarded as a key contributor and may serve as a therapeutic target in many types of pain, likely including neuropathic pain. Here, we reviewed the role of NGF in neuropathic pain of peripheral and central origin, also addressing its potential use as a pharmacological target to better help patients dealing with this condition that severely impacts the everyday life. For this, we conducted a search in the databases PubMed and Scopus. Our search resulted in 1103 articles (458 in PubMed and 645 in Scopus). Only articles related to the involvement of NGF in pain or articles that approached its potential use as a target in treatment of pain symptoms were included. Duplicates were eliminated and 274 articles were excluded. After careful analysis, 23 articles were selected for review. Original articles studying the role of NGF in pathology as well as its modulation as a possible therapeutic target were included. We found that NGF is widely regarded as a key player in neuropathic pain and seen as a putative therapeutic target. However, evidence obtained from years of clinical trials highlights the toxic adverse effects of anti-NGF therapeutics, precluding its use in clinical context. Further studies are, thus, needed to improve treatment of chronic neuropathic pain.
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Affiliation(s)
- Catarina Reis
- Faculty of Medicine of Porto, University of Porto, Porto, Portugal
| | - Sílvia Chambel
- Experimental Biology Unit, Department of Biomedicine, Faculty of Medicine of Porto, University of Porto, Porto, Portugal
- Translational Neurourology, Instituto de Investigação e Inovação em Saúde-i3S and IBMC, Universidade do Porto, Porto, Portugal
| | - Ana Ferreira
- Experimental Biology Unit, Department of Biomedicine, Faculty of Medicine of Porto, University of Porto, Porto, Portugal
- Translational Neurourology, Instituto de Investigação e Inovação em Saúde-i3S and IBMC, Universidade do Porto, Porto, Portugal
| | - Célia Duarte Cruz
- Experimental Biology Unit, Department of Biomedicine, Faculty of Medicine of Porto, University of Porto, Porto, Portugal
- Translational Neurourology, Instituto de Investigação e Inovação em Saúde-i3S and IBMC, Universidade do Porto, Porto, Portugal
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Bouchet C, Cardouat G, Douard M, Coste F, Robillard P, Delcambre F, Ducret T, Quignard JF, Vacher P, Baudrimont I, Marthan R, Berger P, Guibert C, Freund-Michel V. Inflammation and Oxidative Stress Induce NGF Secretion by Pulmonary Arterial Cells through a TGF-β1-Dependent Mechanism. Cells 2022; 11:cells11182795. [PMID: 36139373 PMCID: PMC9496672 DOI: 10.3390/cells11182795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 08/31/2022] [Accepted: 09/02/2022] [Indexed: 11/16/2022] Open
Abstract
Expression of the nerve growth factor NGF is increased in pulmonary hypertension (PH). We have here studied whether oxidative stress and inflammation, two pathological conditions associated with transforming growth factor-β1 (TGF-β1) in PH, may trigger NGF secretion by pulmonary arterial (PA) cells. Effects of hydrogen peroxide (H2O2) and interleukin-1β (IL-1β) were investigated ex vivo on rat pulmonary arteries, as well as in vitro on human PA smooth muscle (hPASMC) or endothelial cells (hPAEC). TβRI expression was assessed by Western blotting. NGF PA secretion was assessed by ELISA after TGF-β1 blockade (anti-TGF-β1 siRNA, TGF-β1 blocking antibodies, TβRI kinase, p38 or Smad3 inhibitors). TβRI PA expression was evidenced by Western blotting both ex vivo and in vitro. H2O2 or IL-1β significantly increased NGF secretion by hPASMC and hPAEC, and this effect was significantly reduced when blocking TGF-β1 expression, binding to TβRI, TβRI activity, or signaling pathways. In conclusion, oxidative stress and inflammation may trigger TGF-β1 secretion by hPASMC and hPAEC. TGF-β1 may then act as an autocrine factor on these cells, increasing NGF secretion via TβRI activation. Since NGF and TGF-β1 are relevant growth factors involved in PA remodeling, such mechanisms may therefore be relevant to PH pathophysiology.
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Affiliation(s)
- Clément Bouchet
- Centre de Recherche Cardio-Thoracique de Bordeaux, University Bordeaux, U1045, 33600 Pessac, France
- INSERM (Institut National de la Santé Et de la Recherche Médicale), Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, 33600 Pessac, France
| | - Guillaume Cardouat
- Centre de Recherche Cardio-Thoracique de Bordeaux, University Bordeaux, U1045, 33600 Pessac, France
- INSERM (Institut National de la Santé Et de la Recherche Médicale), Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, 33600 Pessac, France
| | - Matthieu Douard
- Centre de Recherche Cardio-Thoracique de Bordeaux, University Bordeaux, U1045, 33600 Pessac, France
- INSERM (Institut National de la Santé Et de la Recherche Médicale), Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, 33600 Pessac, France
- IHU Institut de Rythmologie et Modélisation Cardiaque (LIRYC), 33600 Pessac, France
| | - Florence Coste
- Laboratoire de Pharm-Écologie Cardiovasculaire (LaPEC-EA 4278), Université d’Avignon et des Pays du Vaucluse, 84000 Avignon, France
| | - Paul Robillard
- Centre de Recherche Cardio-Thoracique de Bordeaux, University Bordeaux, U1045, 33600 Pessac, France
- INSERM (Institut National de la Santé Et de la Recherche Médicale), Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, 33600 Pessac, France
| | | | - Thomas Ducret
- Centre de Recherche Cardio-Thoracique de Bordeaux, University Bordeaux, U1045, 33600 Pessac, France
- INSERM (Institut National de la Santé Et de la Recherche Médicale), Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, 33600 Pessac, France
| | - Jean-François Quignard
- Centre de Recherche Cardio-Thoracique de Bordeaux, University Bordeaux, U1045, 33600 Pessac, France
- INSERM (Institut National de la Santé Et de la Recherche Médicale), Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, 33600 Pessac, France
| | - Pierre Vacher
- Centre de Recherche Cardio-Thoracique de Bordeaux, University Bordeaux, U1045, 33600 Pessac, France
- INSERM (Institut National de la Santé Et de la Recherche Médicale), Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, 33600 Pessac, France
| | - Isabelle Baudrimont
- Centre de Recherche Cardio-Thoracique de Bordeaux, University Bordeaux, U1045, 33600 Pessac, France
- INSERM (Institut National de la Santé Et de la Recherche Médicale), Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, 33600 Pessac, France
| | - Roger Marthan
- Centre de Recherche Cardio-Thoracique de Bordeaux, University Bordeaux, U1045, 33600 Pessac, France
- INSERM (Institut National de la Santé Et de la Recherche Médicale), Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, 33600 Pessac, France
- CHU de Bordeaux, 33000 Bordeaux, France
| | - Patrick Berger
- Centre de Recherche Cardio-Thoracique de Bordeaux, University Bordeaux, U1045, 33600 Pessac, France
- INSERM (Institut National de la Santé Et de la Recherche Médicale), Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, 33600 Pessac, France
- CHU de Bordeaux, 33000 Bordeaux, France
| | - Christelle Guibert
- Centre de Recherche Cardio-Thoracique de Bordeaux, University Bordeaux, U1045, 33600 Pessac, France
- INSERM (Institut National de la Santé Et de la Recherche Médicale), Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, 33600 Pessac, France
| | - Véronique Freund-Michel
- Centre de Recherche Cardio-Thoracique de Bordeaux, University Bordeaux, U1045, 33600 Pessac, France
- INSERM (Institut National de la Santé Et de la Recherche Médicale), Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, 33600 Pessac, France
- Correspondence:
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Feng J, Hibberd TJ, Luo J, Yang P, Xie Z, Travis L, Spencer NJ, Hu H. Modification of Neurogenic Colonic Motor Behaviours by Chemogenetic Ablation of Calretinin Neurons. Front Cell Neurosci 2022; 16:799717. [PMID: 35317196 PMCID: PMC8934436 DOI: 10.3389/fncel.2022.799717] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Accepted: 01/31/2022] [Indexed: 12/31/2022] Open
Abstract
How the enteric nervous system determines the pacing and propagation direction of neurogenic contractions along the colon remains largely unknown. We used a chemogenetic strategy to ablate enteric neurons expressing calretinin (CAL). Mice expressing human diphtheria toxin receptor (DTR) in CAL neurons were generated by crossing CAL-ires-Cre mice with Cre-dependent ROSA26-DTR mice. Immunohistochemical analysis revealed treatment with diphtheria toxin incurred a 42% reduction in counts of Hu-expressing colonic myenteric neurons (P = 0.036), and 57% loss of CAL neurons (comprising ∼25% of all Hu neurons; P = 0.004) compared to control. As proportions of Hu-expressing neurons, CAL neurons that contained nitric oxide synthase (NOS) were relatively spared (control: 15 ± 2%, CAL-DTR: 13 ± 1%; P = 0.145), while calretinin neurons lacking NOS were significantly reduced (control: 26 ± 2%, CAL-DTR: 18 ± 5%; P = 0.010). Colonic length and pellet sizes were significantly reduced without overt inflammation or changes in ganglionic density. Interestingly, colonic motor complexes (CMCs) persisted with increased frequency (mid-colon interval 111 ± 19 vs. 189 ± 24 s, CAL-DTR vs. control, respectively, P < 0.001), decreased contraction size (mid-colon AUC 26 ± 24 vs. 59 ± 13 gram/seconds, CAL-DTR vs. control, respectively, P < 0.001), and lacked preferential anterograde migration (P < 0.001). The functional effects of modest calretinin neuron ablation, particularly increased neurogenic motor activity frequencies, differ from models that incur general enteric neuron loss, and suggest calretinin neurons may contribute to pacing, force, and polarity of CMCs in the large bowel.
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Affiliation(s)
- Jing Feng
- Center for the Study of Itch and Sensory Disorders, Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO, United States
- Center for Neurological and Psychiatric Research and Drug Discovery, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Tim J. Hibberd
- College of Medicine and Public Health, Centre for Neuroscience, Flinders University, Adelaide, SA, Australia
| | - Jialie Luo
- Center for the Study of Itch and Sensory Disorders, Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO, United States
| | - Pu Yang
- Center for the Study of Itch and Sensory Disorders, Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO, United States
| | - Zili Xie
- Center for the Study of Itch and Sensory Disorders, Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO, United States
| | - Lee Travis
- College of Medicine and Public Health, Centre for Neuroscience, Flinders University, Adelaide, SA, Australia
| | - Nick J. Spencer
- College of Medicine and Public Health, Centre for Neuroscience, Flinders University, Adelaide, SA, Australia
- *Correspondence: Nick J. Spencer,
| | - Hongzhen Hu
- Center for the Study of Itch and Sensory Disorders, Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO, United States
- Hongzhen Hu,
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Matsumoto K, Suenaga M, Mizutani Y, Matsui K, Yoshida A, Nakamoto T, Kato S. Role of transient receptor potential vanilloid subtype 2 in lower oesophageal sphincter in rat acid reflux oesophagitis. J Pharmacol Sci 2021; 146:125-135. [PMID: 34030795 DOI: 10.1016/j.jphs.2021.03.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 03/24/2021] [Accepted: 03/29/2021] [Indexed: 12/12/2022] Open
Abstract
Gastroesophageal reflux disease (GERD) is a common gastrointestinal disorder. In the present study, we investigated TRP vanilloid subfamily member 2 (TRPV2) expression in lower oesophageal sphincter (LES) and its involvement in acid reflux oesophagitis in rats. Expression of TRPV2 and nerve growth factor mRNAs was significantly enhanced in LES of rats with reflux oesophagitis compared with normal rats. TRPV2 was mainly expressed in inhibitory motor neurons, and partly in intrinsic and extrinsic primary afferent neurons, and macrophages in LES of normal and reflux oesophagitis rats. Number of TRPV2-immunopositive nerve fibres was significantly increased, but that of nNOS-, CGRP-, and PGP9.5-nerve fibres was not changed in reflux oesophagitis compared with normal group. Probenecid produced nitric oxide production and relaxation in LES and this response was significantly enhanced in oesophagitis compared with normal group. Probenecid-induced relaxant effect was blocked by a TRPV2 inhibitor, tranilast, and a NOS inhibitor, NG-nitro-l-arginine methyl ester, in reflux oesophagitis rats. Oral administration of tranilast significantly improved body weight loss, oesophageal lesions, and epithelial thickness in oesophagitis model. These results suggest that up-regulation of TRPV2 in inhibitory motor neurons is involved in LES relaxation in oesophagitis model. TRPV2 inhibition might be beneficial for treatment of GERD.
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Affiliation(s)
- Kenjiro Matsumoto
- Division of Pathological Sciences, Department of Pharmacology and Experimental Therapeutics, Kyoto Pharmaceutical University, Kyoto, Japan.
| | - Minako Suenaga
- Division of Pathological Sciences, Department of Pharmacology and Experimental Therapeutics, Kyoto Pharmaceutical University, Kyoto, Japan
| | - Yumi Mizutani
- Division of Pathological Sciences, Department of Pharmacology and Experimental Therapeutics, Kyoto Pharmaceutical University, Kyoto, Japan
| | - Kohei Matsui
- Division of Pathological Sciences, Department of Pharmacology and Experimental Therapeutics, Kyoto Pharmaceutical University, Kyoto, Japan
| | - Ayano Yoshida
- Division of Pathological Sciences, Department of Pharmacology and Experimental Therapeutics, Kyoto Pharmaceutical University, Kyoto, Japan
| | - Tomohiro Nakamoto
- Division of Pathological Sciences, Department of Pharmacology and Experimental Therapeutics, Kyoto Pharmaceutical University, Kyoto, Japan
| | - Shinichi Kato
- Division of Pathological Sciences, Department of Pharmacology and Experimental Therapeutics, Kyoto Pharmaceutical University, Kyoto, Japan
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Abstract
Beyond their well-known role in embryonic development of the central and peripheral nervous system, neurotrophins, particularly nerve growth factor and brain-derived neurotrophic factor, exert an essential role in pain production and sensitization. This has mainly been studied within the framework of somatic pain, and even antibodies (tanezumab and fasinumab) have recently been developed for their use in chronic somatic painful conditions, such as osteoarthritis or low back pain. However, data suggest that neurotrophins also exert an important role in the occurrence of visceral pain and visceral sensitization. Visceral pain is a distressing symptom that prompts many consultations and is typically encountered in both 'organic' (generally inflammatory) and 'functional' (displaying no obvious structural changes in routine clinical evaluations) disorders of the gut, such as inflammatory bowel disease and irritable bowel syndrome, respectively. The present review provides a summary of neurotrophins as a molecular family and their role in pain in general and addresses recent investigations of the involvement of nerve growth factor and brain-derived neurotrophic factor in visceral pain, particularly that associated with inflammatory bowel disease and irritable bowel syndrome.
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Coelho A, Oliveira R, Antunes-Lopes T, Cruz CD. Partners in Crime: NGF and BDNF in Visceral Dysfunction. Curr Neuropharmacol 2019; 17:1021-1038. [PMID: 31204623 PMCID: PMC7052822 DOI: 10.2174/1570159x17666190617095844] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 03/23/2019] [Accepted: 06/03/2019] [Indexed: 12/12/2022] Open
Abstract
Neurotrophins (NTs), particularly Nerve Growth Factor (NGF) and Brain-Derived Neurotrophic Factor (BDNF), have attracted increasing attention in the context of visceral function for some years. Here, we examined the current literature and presented a thorough review of the subject. After initial studies linking of NGF to cystitis, it is now well-established that this neurotrophin (NT) is a key modulator of bladder pathologies, including Bladder Pain Syndrome/Interstitial Cystitis (BPS/IC) and Chronic Prostatitis/Chronic Pelvic Pain Syndrome (CP/CPPS. NGF is upregulated in bladder tissue and its blockade results in major improvements on urodynamic parameters and pain. Further studies expanded showed that NGF is also an intervenient in other visceral dysfunctions such as endometriosis and Irritable Bowel Syndrome (IBS). More recently, BDNF was also shown to play an important role in the same visceral dysfunctions, suggesting that both NTs are determinant factors in visceral pathophysiological mechanisms. Manipulation of NGF and BDNF improves visceral function and reduce pain, suggesting that clinical modulation of these NTs may be important; however, much is still to be investigated before this step is taken. Another active area of research is centered on urinary NGF and BDNF. Several studies show that both NTs can be found in the urine of patients with visceral dysfunction in much higher concentration than in healthy individuals, suggesting that they could be used as potential biomarkers. However, there are still technical difficulties to be overcome, including the lack of a large multicentre placebo-controlled studies to prove the relevance of urinary NTs as clinical biomarkers.
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Affiliation(s)
| | | | | | - Célia Duarte Cruz
- Address correspondence to this author at the Department of Experimental Biology, Experimental Biology Unit, Faculty of Medicine of the University of Porto, Alameda Hernâni Monteiro; Tel: 351 220426740; Fax: +351 225513655; E-mail:
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A potential relationship between gut microbes and atrial fibrillation: Trimethylamine N-oxide, a gut microbe-derived metabolite, facilitates the progression of atrial fibrillation. Int J Cardiol 2018; 255:92-98. [DOI: 10.1016/j.ijcard.2017.11.071] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Revised: 11/11/2017] [Accepted: 11/20/2017] [Indexed: 12/20/2022]
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Jardí F, Fernández-Blanco JA, Martínez V, Vergara P. Persistent alterations in colonic afferent innervation in a rat model of postinfectious gut dysfunction: Role for changes in peripheral neurotrophic factors. Neurogastroenterol Motil 2016; 28:693-704. [PMID: 26768324 DOI: 10.1111/nmo.12766] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 12/02/2015] [Indexed: 01/08/2023]
Abstract
BACKGROUND Visceral hypersensitivity in the inflamed gut is related partly to the effects of peripheral neurotrophic factors (NTFs) on local afferent neurons. However, alterations in sensory afferents of distant areas remain unexplored. Using the Trichinella spiralis infection model, which causes a jejunitis, we investigated the remodeling of colonic afferents and the potential role of NTFs. METHODS Rats were infected with T. spiralis. Inflammatory-like changes, mucosal mast cells (MMCs) dynamics, and expression of nerve growth factor and glial cell line-derived NTFs (glial cell-derived neurotrophic factor, artemin, and neurturin) were determined in the colon up to day 30 postinfection. Functional responses of colonic afferents were determined assessing changes in the expression of sensory-related markers in thoracolumbar (TL)/lumbosacral (LS) dorsal root ganglias (DRGs) following intracolonic capsaicin. KEY RESULTS Trichinella spiralis induced an inflammatory-like response within the colon, partly resolved at day 30 postinfection, except for a persistent MMC infiltrate. While the jejunum of infected animals showed an up-regulation in the expression of NTFs, a transitory down-regulation was observed in the colon. Overall, T. spiralis effects on DRGs gene expression were restricted to a transient down-regulation of TPRV1. Stimulation with intracolonic capsaicin induced a down-regulation of TRPV1 levels in TL and LS DRGs, an effect enhanced in LS DRGs of infected animals, regardless the postinfection time considered. CONCLUSIONS & INFERENCES During intestinal inflammation, spread morphological and functional alterations, including remodeling of visceral afferents, are observed outside the primary region affected by the insult. Similar mechanisms might be operating in states of widespread alterations of visceral sensitivity.
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Affiliation(s)
- F Jardí
- Department of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - J A Fernández-Blanco
- Department of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - V Martínez
- Department of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, Barcelona, Spain.,Instituto de Neurociencias, Universitat Autònoma de Barcelona, Barcelona, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Instituto de Salud Carlos III, Madrid, Spain
| | - P Vergara
- Department of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, Barcelona, Spain.,Instituto de Neurociencias, Universitat Autònoma de Barcelona, Barcelona, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Instituto de Salud Carlos III, Madrid, Spain
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Li Q, Winston JH, Sarna SK. Noninflammatory upregulation of nerve growth factor underlies gastric hypersensitivity induced by neonatal colon inflammation. Am J Physiol Regul Integr Comp Physiol 2015; 310:R235-42. [PMID: 26608656 DOI: 10.1152/ajpregu.00342.2015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 11/18/2015] [Indexed: 02/08/2023]
Abstract
Gastric hypersensitivity is one of the key contributors to the postprandial symptoms of epigastric pain/discomfort, satiety, and fullness in functional dyspepsia patients. Epidemiological studies found that adverse early-life experiences are risk factors for the development of gastric hypersensitivity. Preclinical studies found that neonatal colon inflammation elevates plasma norepinephrine (NE), which upregulates expression of nerve growth factor (NGF) in the muscularis externa of the gastric fundus. Our goal was to investigate the cellular mechanisms by which NE upregulates the expression of NGF in gastric hypersensitive (GHS) rats, which were subjected previously to neonatal colon inflammation. Neonatal colon inflammation upregulated NGF protein, but not mRNA, in the gastric fundus of GHS rats. Western blotting showed upregulation of p110γ of phosphatidylinositol 4,5-bisphosphate 3-kinase (PI3K), phosphoinositide-dependent kinase-1 (PDK1), pAKT(Ser473), and phosphorylated 4E-binding protein (p4E-BP1)(Thr70), suggesting AKT activation and enhanced NGF protein translation. AKT inhibitor MK-2206 blocked the upregulation of NGF in the fundus of GHS rats. Matrix metalloproteinase 9 (MMP-9), the major NGF-degrading protease, was suppressed, indicating that NGF degradation was impeded. Incubation of fundus muscularis externa with NE upregulated NGF by modulating the protein translation and degradation pathways. Yohimbine, an α2-adrenergic receptor antagonist, upregulated plasma NE and NGF expression by activating the protein translation and degradation pathways in naive rats. In contrast, a cocktail of adrenergic receptor antagonists suppressed the upregulation of NGF by blocking the activation of the protein translation and degradation pathways. Our findings provide evidence that the elevation of plasma NE induces NGF expression in the gastric fundus.
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Affiliation(s)
- Qingjie Li
- Enteric Neuromuscular Disorders and Visceral Pain Center, Division of Gastroenterology and Hepatology, Department of Internal Medicine, The University of Texas Medical Branch at Galveston, Galveston, Texas; and
| | - John H Winston
- Enteric Neuromuscular Disorders and Visceral Pain Center, Division of Gastroenterology and Hepatology, Department of Internal Medicine, The University of Texas Medical Branch at Galveston, Galveston, Texas; and
| | - Sushil K Sarna
- Enteric Neuromuscular Disorders and Visceral Pain Center, Division of Gastroenterology and Hepatology, Department of Internal Medicine, The University of Texas Medical Branch at Galveston, Galveston, Texas; and Department of Neuroscience and Cell Biology, The University of Texas Medical Branch at Galveston, Galveston, Texas
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