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Palus K, Chmielewska-Krzesińska M, Jana B, Całka J. Glyphosate-induced changes in the expression of galanin and GALR1, GALR2 and GALR3 receptors in the porcine small intestine wall. Sci Rep 2024; 14:8905. [PMID: 38632282 PMCID: PMC11024183 DOI: 10.1038/s41598-024-59581-8] [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: 09/11/2023] [Accepted: 04/12/2024] [Indexed: 04/19/2024] Open
Abstract
Glyphosate is the active ingredient of glyphosate-based herbicides and the most commonly used pesticide in the world. The goal of the present study was to verify whether low doses of glyphosate (equivalent to the environmental exposure) evoke changes in galanin expression in intramural neurons in the small intestine in pigs and to quantitatively determine changes in the level of galanin receptor encoding mRNA (GALR1, GALR2, GALR3) in the small intestine wall. The experiment was conducted on 15 sexually immature gilts divided into three study groups: control (C)-animals receiving empty gelatin capsules; experimental 1 (G1)-animals receiving a low dose of glyphosate (0.05 mg/kg b.w./day); experimental 2 (G2)-animals receiving a higher dose of glyphosate (0.5 mg/kg b.w./day) orally in gelatine capsules for 28 days. Glyphosate ingestion led to an increase in the number of GAL-like immunoreactive intramural neurons in the porcine small intestine. The results of RT-PCR showed a significant increase in the expression of mRNA, which encodes the GAL-receptors in the ileum, a decreased expression in the duodenum and no significant changes in the jejunum. Additionally, intoxication with glyphosate increased the expression of SOD2-encoding mRNA in the duodenum and decreased it in the jejunum and ileum, but it did not affect SOD1 expression. The results suggest that it may be a consequence of the cytotoxic and/or neurotoxic properties of glyphosate and/or its ability to induce oxidative stress.
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MESH Headings
- Animals
- Female
- Galanin/metabolism
- Glyphosate/metabolism
- Glyphosate/toxicity
- Intestine, Small/drug effects
- Intestine, Small/metabolism
- Receptor, Galanin, Type 2/drug effects
- Receptor, Galanin, Type 2/genetics
- Receptor, Galanin, Type 2/metabolism
- RNA, Messenger/metabolism
- Sus scrofa/genetics
- Swine
- Receptor, Galanin, Type 1/drug effects
- Receptor, Galanin, Type 1/genetics
- Receptor, Galanin, Type 1/metabolism
- Receptor, Galanin, Type 3/drug effects
- Receptor, Galanin, Type 3/genetics
- Receptor, Galanin, Type 3/metabolism
- Herbicides/toxicity
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Affiliation(s)
- Katarzyna Palus
- Department of Clinical Physiology, Faculty of Veterinary Medicine, University of Warmia and Mazury, Oczapowskiego 13, 10-719, Olsztyn, Poland.
| | - Małgorzata Chmielewska-Krzesińska
- Department of Pathophysiology, Forensic Veterinary Medicine and Administration, Faculty of Veterinary Medicine, University of Warmia and Mazury in Olsztyn, Oczapowskiego 13, 10-719, Olsztyn, Poland
| | - Barbara Jana
- Division of Reproductive Biology, Institute of Animal Reproduction and Food Research of the Polish Academy of Sciences, Tuwima 10, 10-078, Olsztyn, Poland
| | - Jarosław Całka
- Department of Clinical Physiology, Faculty of Veterinary Medicine, University of Warmia and Mazury, Oczapowskiego 13, 10-719, Olsztyn, Poland
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Yuan P, Li X, Xiong WJ, Jiang J, Jiang R. Downregulation of the expression of galanin impairs erectile function in hypoandrogenic rats. Sex Med 2023; 11:qfad029. [PMID: 37351545 PMCID: PMC10281959 DOI: 10.1093/sexmed/qfad029] [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: 02/07/2023] [Revised: 04/05/2023] [Accepted: 05/23/2023] [Indexed: 06/24/2023] Open
Abstract
Background The relationship between galanin and erectile function under low androgen levels is still unclear. Aim To explore whether a low testosterone level damages the erection of a rat by regulating the expression of galanin and GalR in penile cavernous tissue. Methods Thirty-six male Sprague-Dawley rats, 8 weeks of age, were randomly grouped as follows (n = 6): control, castration, castration + testosterone replacement, control + transfection, castration + transfection, and castration + empty transfection. At 4 weeks after castration, rats in the transfection group were injected with lentivirus carrying the targeting galanin gene (2 × 108 TU/mL, 10 μL) in the corpus cavernosum. After 1 week of injection, the intracavernosal pressure (ICP), mean arterial blood pressure (MAP), nitric oxide (NO), serum testosterone concentration, galanin, GalR1-3, ROCK1, ROCK2, and p-eNOS/eNOS in the rat penile tissues were evaluated. Outcomes ICPmax/MAP and the expression of galanin in the corpus cavernosum in castrated rats were obviously decreased as compared with those in the control rats. Results The castrated rats showed remarkably lower ICPmax/MAP, galanin, GalR1-3, p-eNOS/eNOS, and NO content and markedly higher ROCK1 and ROCK2 in penile tissues than the control group (P < .05). The transfected rats administrated with LV Gal had obviously higher ICPmax/MAP, p-eNOS/eNOS, and NO content and less ROCK1 and ROCK2 protein expression in the corpus cavernosum when compared with the castration group (P < .05). Clinical Translation Upregulating the expression of galanin in the penile corpus cavernosum might be a novel method of treating erectile dysfunction caused by a low androgen level. Strengths and Limitations The conclusions obtained in the animal experiments need to be confirmed in human data. Conclusion The erectile function of hypoandrogen rats might be inhibited by downregulating the level of galanin and GalR1-3, upregulating ROCK1 and ROCK2 levels, and inhibiting the eNOS/NO signaling pathway in penile corpus cavernosum.
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Affiliation(s)
| | | | - Wen-ju Xiong
- Department of Urology, The Affiliated Hospital of Southwest Medical University, Luzhou, 646000, China
| | - Jun Jiang
- Corresponding authors: Department of Thyroid Surgery, The Affiliated Hospital of Southwest Medical University, Taiping Road, Luzhou, Sichuan 646000, China. . Department of Urology, Nephropathy Clinical Medical Research Center of Sichuan Province, The Affiliated Hospital of Southwest Medical University, Taiping Road, Luzhou, Sichuan 646000, China.
| | - Rui Jiang
- Corresponding authors: Department of Thyroid Surgery, The Affiliated Hospital of Southwest Medical University, Taiping Road, Luzhou, Sichuan 646000, China. . Department of Urology, Nephropathy Clinical Medical Research Center of Sichuan Province, The Affiliated Hospital of Southwest Medical University, Taiping Road, Luzhou, Sichuan 646000, China.
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Diaz JR, Martá-Ariza M, Khodadadi-Jamayran A, Heguy A, Tsirigos A, Pankiewicz JE, Sullivan PM, Sadowski MJ. Apolipoprotein E4 Effects a Distinct Transcriptomic Profile and Dendritic Arbor Characteristics in Hippocampal Neurons Cultured in vitro. Front Aging Neurosci 2022; 14:845291. [PMID: 35572125 PMCID: PMC9099260 DOI: 10.3389/fnagi.2022.845291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 04/06/2022] [Indexed: 11/13/2022] Open
Abstract
The APOE gene is diversified by three alleles ε2, ε3, and ε4 encoding corresponding apolipoprotein (apo) E isoforms. Possession of the ε4 allele is signified by increased risks of age-related cognitive decline, Alzheimer's disease (AD), and the rate of AD dementia progression. ApoE is secreted by astrocytes as high-density lipoprotein-like particles and these are internalized by neurons upon binding to neuron-expressed apoE receptors. ApoE isoforms differentially engage neuronal plasticity through poorly understood mechanisms. We examined here the effects of native apoE lipoproteins produced by immortalized astrocytes homozygous for ε2, ε3, and ε4 alleles on the maturation and the transcriptomic profile of primary hippocampal neurons. Control neurons were grown in the presence of conditioned media from Apoe -/- astrocytes. ApoE2 and apoE3 significantly increase the dendritic arbor branching, the combined neurite length, and the total arbor surface of the hippocampal neurons, while apoE4 fails to produce similar effects and even significantly reduces the combined neurite length compared to the control. ApoE lipoproteins show no systemic effect on dendritic spine density, yet apoE2 and apoE3 increase the mature spines fraction, while apoE4 increases the immature spine fraction. This is associated with opposing effects of apoE2 or apoE3 and apoE4 on the expression of NR1 NMDA receptor subunit and PSD95. There are 1,062 genes differentially expressed across neurons cultured in the presence of apoE lipoproteins compared to the control. KEGG enrichment and gene ontology analyses show apoE2 and apoE3 commonly activate expression of genes involved in neurite branching, and synaptic signaling. In contrast, apoE4 cultured neurons show upregulation of genes related to the glycolipid metabolism, which are involved in dendritic spine turnover, and those which are usually silent in neurons and are related to cell cycle and DNA repair. In conclusion, our work reveals that lipoprotein particles comprised of various apoE isoforms differentially regulate various neuronal arbor characteristics through interaction with neuronal transcriptome. ApoE4 produces a functionally distinct transcriptomic profile, which is associated with attenuated neuronal development. Differential regulation of neuronal transcriptome by apoE isoforms is a newly identified biological mechanism, which has both implication in the development and aging of the CNS.
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Affiliation(s)
- Jenny R. Diaz
- Department of Neurology, New York University Grossman School of Medicine, New York, NY, United States
| | - Mitchell Martá-Ariza
- Department of Neurology, New York University Grossman School of Medicine, New York, NY, United States
| | | | - Adriana Heguy
- Department of Pathology, New York University Grossman School of Medicine, New York, NY, United States
| | - Aristotelis Tsirigos
- Department of Pathology, New York University Grossman School of Medicine, New York, NY, United States
| | - Joanna E. Pankiewicz
- Department of Neurology, New York University Grossman School of Medicine, New York, NY, United States
- Department of Biochemistry and Pharmacology, New York University Grossman School of Medicine, New York, NY, United States
| | - Patrick M. Sullivan
- Department of Medicine (Geriatrics), Duke University School of Medicine, Durham, NC, United States
- Durham VA Medical Center’s, Geriatric Research Education and Clinical Center, Durham, NC, United States
| | - Martin J. Sadowski
- Department of Neurology, New York University Grossman School of Medicine, New York, NY, United States
- Department of Biochemistry and Pharmacology, New York University Grossman School of Medicine, New York, NY, United States
- Department of Psychiatry, New York University Grossman School of Medicine, New York, NY, United States
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Pisarenko OI, Studneva IM, Veselova OM. Modified N-Terminal Fragments of Galanin: Cardioprotective Properties and Mechanisms of Action. BIOCHEMISTRY. BIOKHIMIIA 2021; 86:1342-1351. [PMID: 34903156 DOI: 10.1134/s000629792110014x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The design of new drugs for treatment of cardiovascular diseases based on endogenous peptide hormones is of undoubted interest and stimulates intensive experimental research. One of the approaches for development in this area is synthesis of the short bioactive peptides that mimic effects of the larger peptide molecules and have improved physicochemical characteristics. In recent years, it has been found that the N-terminal fragments of the neuropeptide galanin reduce metabolic and functional disorders in the experimental heart damage. The review presents literature data and generalized results of our own experiments on the effects of the full-size galanin and its chemically modified N-terminal fragments (2-11) and (2-15) on the heart in normal conditions and in modeling pathophysiological conditions in vitro and in vivo. It has been shown that the spectrum of the peptide actions on the damaged myocardium includes decrease in the necrotic death of cardiomyocytes, decrease in the damage of sarcolemma, improvement in the metabolic state of myocardium, decrease in the formation of reactive oxygen species (ROS) and lipid peroxidation (LPO) products. Mechanisms of the protective action of the modified galanin fragments associated with activation of the GalR2 receptor subtype and manifestation of antioxidant properties are discussed. The data summarized in the review indicate that the molecular design of pharmacological agonists of the GalR2 receptor is a promising approach, because they can serve as a basis for the development of cardioprotectors influencing processes of free radical oxidation and metabolic adaptation.
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Affiliation(s)
- Oleg I Pisarenko
- National Medical Research Center for Cardiology, Moscow, 121552, Russia.
| | - Irina M Studneva
- National Medical Research Center for Cardiology, Moscow, 121552, Russia
| | - Oxana M Veselova
- National Medical Research Center for Cardiology, Moscow, 121552, Russia
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Brzozowska M, Całka J. Review: Occurrence and Distribution of Galanin in the Physiological and Inflammatory States in the Mammalian Gastrointestinal Tract. Front Immunol 2021; 11:602070. [PMID: 33552060 PMCID: PMC7862705 DOI: 10.3389/fimmu.2020.602070] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Accepted: 12/11/2020] [Indexed: 12/13/2022] Open
Abstract
Galanin (GAL) is a broad-spectrum peptide that was first identified 37 years ago. GAL, which acts through three specific receptor subtypes, is one of the most important molecules on an ever-growing list of neurotransmitters. Recent studies indicate that this peptide is commonly present in the gastrointestinal (GI) tract and GAL distribution can be seen in the enteric nervous system (ENS). The function of the GAL in the gastrointestinal tract is, inter alia, to regulate motility and secretion. It should be noted that the distribution of neuropeptides is largely dependent on the research model, as well as the part of the gastrointestinal tract under study. During the development of digestive disorders, fluctuations in GAL levels were observed. The occurrence of GAL largely depends on the stage of the disease, e.g., in porcine experimental colitis GAL secretion is caused by infection with Brachyspira hyodysenteriae. Many authors have suggested that increased GAL presence is related to the involvement of GAL in organ renewal. Additionally, it is tempting to speculate that GAL may be used in the treatment of gastroenteritis. This review aims to present the function of GAL in the mammalian gastrointestinal tract under physiological conditions. In addition, since GAL is undoubtedly involved in the regulation of inflammatory processes, and the aim of this publication is to provide up-to-date knowledge of the distribution of GAL in experimental models of gastrointestinal inflammation, which may help to accurately determine the role of this peptide in inflammatory diseases and its potential future use in the treatment of gastrointestinal disorders.
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Affiliation(s)
- Marta Brzozowska
- Department of Clinical Physiology, Faculty of Veterinary Medicine, University of Warmia and Mazury, Olsztyn, Poland
| | - Jarosław Całka
- Department of Clinical Physiology, Faculty of Veterinary Medicine, University of Warmia and Mazury, Olsztyn, Poland
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Yu M, Fang P, Wang H, Shen G, Zhang Z, Tang Z. Beneficial effects of galanin system on diabetic peripheral neuropathic pain and its complications. Peptides 2020; 134:170404. [PMID: 32898581 DOI: 10.1016/j.peptides.2020.170404] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 09/01/2020] [Accepted: 09/02/2020] [Indexed: 11/16/2022]
Abstract
Diabetic peripheral neuropathic pain (DPNP) is a distal spontaneous pain, caused by lesion of sensory neurons and accompanied by depression and anxiety frequently, which reduce life quality of patients and increase society expenditure. To date, antidepressants, serotonin-noradrenaline reuptake inhibitors and anticonvulsants are addressed as first-line therapy to DPNP, alone or jointly. It is urgently necessary to develop novel agents to treat DPNP and its complications. Evidences indicate that neuropeptide galanin can regulate multiple physiologic and pathophysiological processes. Pain, depression and anxiety may upregulate galanin expression. In return, galanin can modulate depression, anxiety, pain threshold and pain behaviors. This article provides a new insight into regulative effects of galanin and its subtype receptors on antidepressant, antianxiety and against DPNP. Through activating GALR1, galanin reinforces depression-like and anxiogenic-like behaviors, but exerts antinociceptive roles. While via activating GALR2, galanin is referred to as anti-depressive and anti-anxiotropic compounds, and at low and high concentration facilitates and inhibits nociceptor activity, respectively. The mechanism of the galanin roles is relative to increase in K+ currents and decrease in Ca2+ currents, as well as neurotrophic and neuroprotective roles. These data are helpful to develop novel drugs to treat DPNP and its complications.
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Affiliation(s)
- Mei Yu
- Department of Physiology, School of Medicine and Life Sciences, Nanjing University of Chinese Medicine, Nanjing, Jiangsu, 210023, China; Department of Pharmacy, Taizhou Hospital of Traditional Chinese Medicine, Nanjing University of Chinese Medicine, Taizhou, Jiangsu, 225300, China
| | - Penghua Fang
- Department of Physiology, School of Medicine and Life Sciences, Nanjing University of Chinese Medicine, Nanjing, Jiangsu, 210023, China
| | - Hua Wang
- Department of Pharmacy, Taizhou Hospital of Traditional Chinese Medicine, Nanjing University of Chinese Medicine, Taizhou, Jiangsu, 225300, China
| | - Guiqin Shen
- Department of Pharmacy, Taizhou Hospital of Traditional Chinese Medicine, Nanjing University of Chinese Medicine, Taizhou, Jiangsu, 225300, China
| | - Zhenwen Zhang
- Department of Endocrinology, Clinical Medical College, Yangzhou University, Yangzhou, Jiangsu, 225001, China.
| | - Zongxiang Tang
- Department of Physiology, School of Medicine and Life Sciences, Nanjing University of Chinese Medicine, Nanjing, Jiangsu, 210023, China.
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Abot A, Lucas A, Bautzova T, Bessac A, Fournel A, Le-Gonidec S, Valet P, Moro C, Cani PD, Knauf C. Galanin enhances systemic glucose metabolism through enteric Nitric Oxide Synthase-expressed neurons. Mol Metab 2018; 10:100-108. [PMID: 29428595 PMCID: PMC5985240 DOI: 10.1016/j.molmet.2018.01.020] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Revised: 01/12/2018] [Accepted: 01/23/2018] [Indexed: 12/14/2022] Open
Abstract
Objective Decreasing duodenal contraction is now considered as a major focus for the treatment of type 2 diabetes. Therefore, identifying bioactive molecules able to target the enteric nervous system, which controls the motility of intestinal smooth muscle cells, represents a new therapeutic avenue. For this reason, we chose to study the impact of oral galanin on this system in diabetic mice. Methods Enteric neurotransmission, duodenal contraction, glucose absorption, modification of gut–brain axis, and glucose metabolism (glucose tolerance, insulinemia, glucose entry in tissue, hepatic glucose metabolism) were assessed. Results We show that galanin, a neuropeptide expressed in the small intestine, decreases duodenal contraction by stimulating nitric oxide release from enteric neurons. This is associated with modification of hypothalamic nitric oxide release that favors glucose uptake in metabolic tissues such as skeletal muscle, liver, and adipose tissue. Oral chronic gavage with galanin in diabetic mice increases insulin sensitivity, which is associated with an improvement of several metabolic parameters such as glucose tolerance, fasting blood glucose, and insulin. Conclusion Here, we demonstrate that oral galanin administration improves glucose homeostasis via the enteric nervous system and could be considered a therapeutic potential for the treatment of T2D. Targeting the enteric nervous system (ENS) is an innovative solution to treat diabetes. The ENS controls duodenal contractions to modulate glycemia via the gut–brain axis. ENS/contractions are targeted by the neuropeptide galanin in the intestine. Oral galanin treatment decreases duodenal hyper-contractility in diabetic mice. Oral galanin restores the gut–brain axis to improve glycemia in diabetic mice.
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Affiliation(s)
- Anne Abot
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1220, Université Paul Sabatier, UPS, Institut de Recherche en Santé Digestive et Nutrition (IRSD), CHU Purpan, Place du Docteur Baylac, CS 60039, 31024 Toulouse Cedex 3, France; NeuroMicrobiota, European Associated Laboratory (EAL) INSERM/UCL, France
| | - Alexandre Lucas
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1048, Université Paul Sabatier, UPS, Institut des Maladies Métaboliques et Cardiovasculaires (I2MC), CHU Rangueil, 1 Avenue Jean Poulhès, BP84225, 31432 Toulouse Cedex 4, France
| | - Tereza Bautzova
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1220, Université Paul Sabatier, UPS, Institut de Recherche en Santé Digestive et Nutrition (IRSD), CHU Purpan, Place du Docteur Baylac, CS 60039, 31024 Toulouse Cedex 3, France; NeuroMicrobiota, European Associated Laboratory (EAL) INSERM/UCL, France
| | - Arnaud Bessac
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1220, Université Paul Sabatier, UPS, Institut de Recherche en Santé Digestive et Nutrition (IRSD), CHU Purpan, Place du Docteur Baylac, CS 60039, 31024 Toulouse Cedex 3, France; NeuroMicrobiota, European Associated Laboratory (EAL) INSERM/UCL, France
| | - Audren Fournel
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1220, Université Paul Sabatier, UPS, Institut de Recherche en Santé Digestive et Nutrition (IRSD), CHU Purpan, Place du Docteur Baylac, CS 60039, 31024 Toulouse Cedex 3, France; NeuroMicrobiota, European Associated Laboratory (EAL) INSERM/UCL, France
| | - Sophie Le-Gonidec
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1048, Université Paul Sabatier, UPS, Institut des Maladies Métaboliques et Cardiovasculaires (I2MC), CHU Rangueil, 1 Avenue Jean Poulhès, BP84225, 31432 Toulouse Cedex 4, France
| | - Philippe Valet
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1048, Université Paul Sabatier, UPS, Institut des Maladies Métaboliques et Cardiovasculaires (I2MC), CHU Rangueil, 1 Avenue Jean Poulhès, BP84225, 31432 Toulouse Cedex 4, France
| | - Cédric Moro
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1048, Université Paul Sabatier, UPS, Institut des Maladies Métaboliques et Cardiovasculaires (I2MC), CHU Rangueil, 1 Avenue Jean Poulhès, BP84225, 31432 Toulouse Cedex 4, France
| | - Patrice D Cani
- NeuroMicrobiota, European Associated Laboratory (EAL) INSERM/UCL, France; Université Catholique de Louvain (UCL), Louvain Drug Research Institute, LDRI, Metabolism and Nutrition Research Group, WELBIO (Walloon Excellence in Life sciences and BIOtechnology), Avenue E. Mounier, 73 B1.73.11, B-1200, Brussels, Belgium.
| | - Claude Knauf
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1220, Université Paul Sabatier, UPS, Institut de Recherche en Santé Digestive et Nutrition (IRSD), CHU Purpan, Place du Docteur Baylac, CS 60039, 31024 Toulouse Cedex 3, France; NeuroMicrobiota, European Associated Laboratory (EAL) INSERM/UCL, France.
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Local cholinergic-GABAergic circuitry within the basal forebrain is modulated by galanin. Brain Struct Funct 2016; 222:1385-1400. [PMID: 27496091 DOI: 10.1007/s00429-016-1283-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Accepted: 07/26/2016] [Indexed: 02/07/2023]
Abstract
The basal forebrain (BF) is an important regulator of hippocampal and cortical activity. In Alzheimer's disease (AD), there is a significant loss and dysfunction of cholinergic neurons within the BF, and also a hypertrophy of fibers containing the neuropeptide galanin. Understanding how galanin interacts with BF circuitry is critical in determining what role galanin overexpression plays in the progression of AD. Here, we examined the location and function of galanin in the medial septum/diagonal band (MS/DBB) region of the BF. We show that galanin fibers are located throughout the MS/DBB and intermingled with both cholinergic and GABAergic neurons. Whole-cell patch clamp recordings from MS/DBB neurons in acute slices reveal that galanin decreases tetrodotoxin-sensitive spontaneous GABA release and dampens muscarinic receptor-mediated increases in GABA release in the MS/DBB. These effects are not blocked by pre-exposure to β-amyloid peptide (Aβ1-42). Optogenetic activation of cholinergic neurons in the MS/DBB increases GABA release back onto cholinergic neurons, forming a functional circuit within the MS/DBB. Galanin disrupts this cholinergic-GABAergic circuit by blocking the cholinergic-induced increase in GABA release. These data suggest that galanin works in the BF to reduce inhibitory input onto cholinergic neurons and to prevent cholinergic-induced increase in inhibitory tone. This disinhibition of cholinergic neurons could serve as a compensatory mechanism to counteract the loss of cholinergic signaling that occurs during the progression of AD.
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Campbell JC, Polan-Couillard LF, Chin-Sang ID, Bendena WG. NPR-9, a Galanin-Like G-Protein Coupled Receptor, and GLR-1 Regulate Interneuronal Circuitry Underlying Multisensory Integration of Environmental Cues in Caenorhabditis elegans. PLoS Genet 2016; 12:e1006050. [PMID: 27223098 PMCID: PMC4880332 DOI: 10.1371/journal.pgen.1006050] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 04/21/2016] [Indexed: 11/27/2022] Open
Abstract
C. elegans inhabit environments that require detection of diverse stimuli to modulate locomotion in order to avoid unfavourable conditions. In a mammalian context, a failure to appropriately integrate environmental signals can lead to Parkinson’s, Alzheimer’s, and epilepsy. Provided that the circuitry underlying mammalian sensory integration can be prohibitively complex, we analyzed nematode behavioral responses in differing environmental contexts to evaluate the regulation of context dependent circuit reconfiguration and sensorimotor control. Our work has added to the complexity of a known parallel circuit, mediated by interneurons AVA and AIB, that integrates sensory cues and is responsible for the initiation of backwards locomotion. Our analysis of the galanin-like G-protein coupled receptor NPR-9 in C. elegans revealed that upregulation of galanin signaling impedes the integration of sensory evoked neuronal signals. Although the expression pattern of npr-9 is limited to AIB, upregulation of the receptor appears to impede AIB and AVA circuits to broadly prevent backwards locomotion, i.e. reversals, suggesting that these two pathways functionally interact. Galanin signaling similarly plays a broadly inhibitory role in mammalian models. Moreover, our identification of a mutant, which rarely initiates backwards movement, allowed us to interrogate locomotory mechanisms underlying chemotaxis. In support of the pirouette model of chemotaxis, organisms that did not exhibit reversal behavior were unable to navigate towards an attractant peak. We also assessed ionotropic glutamate receptor GLR-1 cell-specifically within AIB and determined that GLR-1 fine-tunes AIB activity to modify locomotion following reversal events. Our research highlights that signal integration underlying the initiation and fine-tuning of backwards locomotion is AIB and NPR-9 dependent, and has demonstrated the suitability of C. elegans for analysis of multisensory integration and sensorimotor control. Multiple environmental cues are sensed by an organism in order to coordinate behavioral responses. Consequently, organisms must be able to simultaneously detect and integrate multiple external stimuli in order to appropriately modify their behavior. Identifying the unique circuits mediating the response to individual stimuli and points of overlap is essential to understanding how multiple signals can be integrated for a coordinated behavioral response. In order to analyze individual circuits, we have used the model organism C. elegans. We have identified that a C. elegans neuropeptide receptor (NPR-9) and a glutamate receptor (GLR-1) function in a single interneuron to play a broad regulatory role in multiple neural circuits. Our research has identified that interneuron AIB is involved in the integration of signals from numerous sensory neurons. Moreover, regulation of AIB via a neuropeptide receptor (NPR-9) and a glutamate receptor (GLR-1) coordinates AIB activity in the context of multisensory integration. Long-range chemotaxis behavior, in which an organism alters locomotory patterns based on odorant sensation, is also regulated by NPR-9. Our analysis indicates that reversals, and thus the pirouette model, are sufficient for chemotaxis.
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Affiliation(s)
- Jason C. Campbell
- Department of Biology, Queen’s University, Kingston, Ontario, Canada
| | | | - Ian D. Chin-Sang
- Department of Biology, Queen’s University, Kingston, Ontario, Canada
| | - William G. Bendena
- Department of Biology, Queen’s University, Kingston, Ontario, Canada
- Centre for Neuroscience, Queen’s University, Kingston, Ontario, Canada
- * E-mail:
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Zalecki M, Sienkiewicz W, Franke-Radowiecka A, Klimczuk M, Kaleczyc J. The Influence of Gastric Antral Ulcerations on the Expression of Galanin and GalR1, GalR2, GalR3 Receptors in the Pylorus with Regard to Gastric Intrinsic Innervation of the Pyloric Sphincter. PLoS One 2016; 11:e0155658. [PMID: 27175780 PMCID: PMC4866767 DOI: 10.1371/journal.pone.0155658] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 05/02/2016] [Indexed: 01/29/2023] Open
Abstract
Gastric antrum ulcerations are common disorders occurring in humans and animals. Such localization of ulcers disturbs the gastric emptying process, which is precisely controlled by the pylorus. Galanin (Gal) and its receptors are commonly accepted to participate in the regulation of inflammatory processes and neuronal plasticity. Their role in the regulation of gastrointestinal motility is also widely described. However, there is lack of data considering antral ulcerations in relation to changes in the expression of Gal and GalR1, GalR2, GalR3 receptors in the pyloric wall tissue and galaninergic intramural innervation of the pylorus. Two groups of pigs were used in the study: healthy gilts and gilts with experimentally induced antral ulcers. By double immunocytochemistry percentages of myenteric and submucosal neurons expressing Gal-immunoreactivity were determined in the pyloric wall tissue and in the population of gastric descending neurons supplying the pyloric sphincter (labelled by retrograde Fast Blue neuronal tracer). The percentage of Gal-immunoreactive neurons increased only in the myenteric plexus of the pyloric wall (from 16.14±2.06% in control to 25.5±2.07% in experimental animals), while no significant differences in other neuronal populations were observed between animals of both groups. Real-Time PCR revealed the increased expression of mRNA encoding Gal and GalR1 receptor in the pyloric wall tissue of the experimental animals, while the expression(s) of GalR2 and GalR3 were not significantly changed. The results obtained suggest the involvement of Gal, GalR1 and galaninergic pyloric myenteric neurons in the response of pyloric wall structures to antral ulcerations.
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Affiliation(s)
- Michal Zalecki
- Department of Animal Anatomy, Faculty of Veterinary Medicine, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
- * E-mail:
| | - Waldemar Sienkiewicz
- Department of Animal Anatomy, Faculty of Veterinary Medicine, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
| | - Amelia Franke-Radowiecka
- Department of Animal Anatomy, Faculty of Veterinary Medicine, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
| | - Magdalena Klimczuk
- Department of Animal Anatomy, Faculty of Veterinary Medicine, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
| | - Jerzy Kaleczyc
- Department of Animal Anatomy, Faculty of Veterinary Medicine, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
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11
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Psichas A, Glass LL, Sharp SJ, Reimann F, Gribble FM. Galanin inhibits GLP-1 and GIP secretion via the GAL1 receptor in enteroendocrine L and K cells. Br J Pharmacol 2016; 173:888-98. [PMID: 26661062 PMCID: PMC4761093 DOI: 10.1111/bph.13407] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Revised: 11/26/2015] [Accepted: 12/03/2015] [Indexed: 12/19/2022] Open
Abstract
Background and Purpose Galanin is a widely expressed neuropeptide, which in the gut is thought to modulate gastrointestinal motility and secretion. We aimed to elucidate the poorly characterised mechanisms underlying the inhibitory effect of galanin and the potential involvement of G‐protein coupled inwardly rectifying potassium, Kir3, (GIRK) channels in glucagon‐like peptide 1 (GLP‐1) and glucose‐dependent insulinotropic polypeptide (GIP) secretion. Experimental Approach Purified murine L and K cells were analysed for expression of galanin receptors and GIRK subunits. Hormone secretion was measured from primary murine intestinal cultures. Intracellular cAMP was monitored in primary L cells derived from mice expressing the Epac2camps sensor under the control of the proglucagon promoter. Key Results Galanin receptor 1 (GAL1, Galr1) and GIRK channel 1 (Kir3.1, Kcnj3) and 4 (Kir3.4, Kcnj5) mRNA expression was highly enriched in K and L cells. Galanin and a selective GAL1 receptor agonist (M617) potently inhibited GLP‐1 and GIP secretion from primary small intestinal cultures. In L cells, galanin significantly inhibited the forskolin‐induced cAMP response. The GIRK1/4 activator ML297 significantly reduced glucose‐stimulated and IBMX‐stimulated GLP‐1 secretion but had no effect on GIP. The GIRK blocker tertiapin‐Q did not impair galanin‐mediated GLP‐1 inhibition. Conclusions and Implications Galanin, acting via the GAL1 receptor and Gi‐coupled signalling in L and K cells, is a potent inhibitor of GLP‐1 and GIP secretion. Although GIRK1/4 channels are expressed in these cells, their activation does not appear to play a major role in galanin‐mediated inhibition of incretin secretion.
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Affiliation(s)
- Arianna Psichas
- Metabolic Research Laboratories and MRC Metabolic Diseases Unit, WT-MRC Institute of Metabolic Science, Addenbrooke's Hospital, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - Leslie L Glass
- Metabolic Research Laboratories and MRC Metabolic Diseases Unit, WT-MRC Institute of Metabolic Science, Addenbrooke's Hospital, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - Stephen J Sharp
- MRC Epidemiology Unit, WT-MRC Institute of Metabolic Science, Addenbrooke's Hospital, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - Frank Reimann
- Metabolic Research Laboratories and MRC Metabolic Diseases Unit, WT-MRC Institute of Metabolic Science, Addenbrooke's Hospital, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - Fiona M Gribble
- Metabolic Research Laboratories and MRC Metabolic Diseases Unit, WT-MRC Institute of Metabolic Science, Addenbrooke's Hospital, University of Cambridge, Cambridge, CB2 0QQ, UK
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Laque A, Yu S, Qualls-Creekmore E, Gettys S, Schwartzenburg C, Bui K, Rhodes C, Berthoud HR, Morrison CD, Richards BK, Münzberg H. Leptin modulates nutrient reward via inhibitory galanin action on orexin neurons. Mol Metab 2015; 4:706-17. [PMID: 26500842 PMCID: PMC4588437 DOI: 10.1016/j.molmet.2015.07.002] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2015] [Revised: 07/01/2015] [Accepted: 07/06/2015] [Indexed: 11/30/2022] Open
Abstract
Objective Leptin modulates food reward via central leptin receptor (LepRb) expressing neurons. Food reward requires stimulation of midbrain dopamine neurons and is modulated by central leptin action, but the exact central mechanisms remain unclear. Stimulatory and inhibitory leptin actions on dopamine neurons have been reported, e.g. by indirect actions on orexin neurons or via direct innervation of dopamine neurons in the ventral tegmental area. Methods We showed earlier that LepRb neurons in the lateral hypothalamus (LHA) co-express the inhibitory acting neuropeptide galanin (GAL-LepRb neurons). We studied the involvement of GAL-LepRb neurons to regulate nutrient reward in mice with selective LepRb deletion from galanin neurons (GAL-LepRbKO mice). Results We found that the rewarding value and preference for sucrose over fat was increased in GAL-LepRbKO mice compared to controls. LHA GAL-LepRb neurons innervate orexin neurons, but not the VTA. Further, expression of galanin and its receptor GalR1 are decreased in the LHA of GAL-LepRbKO mice, resulting in increased activation of orexin neurons. Conclusion We suggest galanin as an important mediator of leptin action to modulate nutrient reward by inhibiting orexin neurons. GAL-LepRbKO shows ↓ galanin and ↓ GalR1 mRNA, ↑ body weight gain. GAL-LepRbKO shows ↑ orexin/hypocretin neuronal activation. GAL-LepRb neurons innervate local orexin/hypocretin and noradrenergic locus coeruleus neurons. Leptin regulates natural reward and body weight via GAL-LepRb neurons.
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Affiliation(s)
- Amanda Laque
- Central Leptin Signaling Laboratory, Pennington Biomedical Research Center, LSU System, Baton Rouge, LA, USA
| | - Sangho Yu
- Central Leptin Signaling Laboratory, Pennington Biomedical Research Center, LSU System, Baton Rouge, LA, USA
| | - Emily Qualls-Creekmore
- Central Leptin Signaling Laboratory, Pennington Biomedical Research Center, LSU System, Baton Rouge, LA, USA
| | - Sarah Gettys
- Central Leptin Signaling Laboratory, Pennington Biomedical Research Center, LSU System, Baton Rouge, LA, USA
| | - Candice Schwartzenburg
- Central Leptin Signaling Laboratory, Pennington Biomedical Research Center, LSU System, Baton Rouge, LA, USA
| | - Kelly Bui
- Central Leptin Signaling Laboratory, Pennington Biomedical Research Center, LSU System, Baton Rouge, LA, USA
| | | | - Hans-Rudolf Berthoud
- Neurobiology of Nutrition Laboratory, Pennington Biomedical Research Center, LSU System, Baton Rouge, LA, USA
| | - Christopher D Morrison
- Neurosignaling Laboratory, Pennington Biomedical Research Center, LSU System, Baton Rouge, LA, USA
| | - Brenda K Richards
- Genetics of Eating Behavior Laboratory, Pennington Biomedical Research Center, LSU System, Baton Rouge, LA, USA
| | - Heike Münzberg
- Central Leptin Signaling Laboratory, Pennington Biomedical Research Center, LSU System, Baton Rouge, LA, USA
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13
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Lang R, Gundlach AL, Holmes FE, Hobson SA, Wynick D, Hökfelt T, Kofler B. Physiology, signaling, and pharmacology of galanin peptides and receptors: three decades of emerging diversity. Pharmacol Rev 2015; 67:118-75. [PMID: 25428932 DOI: 10.1124/pr.112.006536] [Citation(s) in RCA: 218] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Galanin was first identified 30 years ago as a "classic neuropeptide," with actions primarily as a modulator of neurotransmission in the brain and peripheral nervous system. Other structurally-related peptides-galanin-like peptide and alarin-with diverse biologic actions in brain and other tissues have since been identified, although, unlike galanin, their cognate receptors are currently unknown. Over the last two decades, in addition to many neuronal actions, a number of nonneuronal actions of galanin and other galanin family peptides have been described. These include actions associated with neural stem cells, nonneuronal cells in the brain such as glia, endocrine functions, effects on metabolism, energy homeostasis, and paracrine effects in bone. Substantial new data also indicate an emerging role for galanin in innate immunity, inflammation, and cancer. Galanin has been shown to regulate its numerous physiologic and pathophysiological processes through interactions with three G protein-coupled receptors, GAL1, GAL2, and GAL3, and signaling via multiple transduction pathways, including inhibition of cAMP/PKA (GAL1, GAL3) and stimulation of phospholipase C (GAL2). In this review, we emphasize the importance of novel galanin receptor-specific agonists and antagonists. Also, other approaches, including new transgenic mouse lines (such as a recently characterized GAL3 knockout mouse) represent, in combination with viral-based techniques, critical tools required to better evaluate galanin system physiology. These in turn will help identify potential targets of the galanin/galanin-receptor systems in a diverse range of human diseases, including pain, mood disorders, epilepsy, neurodegenerative conditions, diabetes, and cancer.
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Affiliation(s)
- Roland Lang
- Department of Dermatology (R.L.) and Laura Bassi Centre of Expertise, Department of Pediatrics (B.K.), Paracelsus Private Medical University, Salzburg, Austria; The Florey Institute of Neuroscience and Mental Health, and Florey Department of Neuroscience and Mental Health, The University of Melbourne, Melbourne, Victoria, Australia (A.L.G.); Schools of Physiology and Pharmacology and Clinical Sciences, Bristol University, Bristol, United Kingdom (F.E.H., S.A.H., D.W.); and Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden (T.H.)
| | - Andrew L Gundlach
- Department of Dermatology (R.L.) and Laura Bassi Centre of Expertise, Department of Pediatrics (B.K.), Paracelsus Private Medical University, Salzburg, Austria; The Florey Institute of Neuroscience and Mental Health, and Florey Department of Neuroscience and Mental Health, The University of Melbourne, Melbourne, Victoria, Australia (A.L.G.); Schools of Physiology and Pharmacology and Clinical Sciences, Bristol University, Bristol, United Kingdom (F.E.H., S.A.H., D.W.); and Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden (T.H.)
| | - Fiona E Holmes
- Department of Dermatology (R.L.) and Laura Bassi Centre of Expertise, Department of Pediatrics (B.K.), Paracelsus Private Medical University, Salzburg, Austria; The Florey Institute of Neuroscience and Mental Health, and Florey Department of Neuroscience and Mental Health, The University of Melbourne, Melbourne, Victoria, Australia (A.L.G.); Schools of Physiology and Pharmacology and Clinical Sciences, Bristol University, Bristol, United Kingdom (F.E.H., S.A.H., D.W.); and Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden (T.H.)
| | - Sally A Hobson
- Department of Dermatology (R.L.) and Laura Bassi Centre of Expertise, Department of Pediatrics (B.K.), Paracelsus Private Medical University, Salzburg, Austria; The Florey Institute of Neuroscience and Mental Health, and Florey Department of Neuroscience and Mental Health, The University of Melbourne, Melbourne, Victoria, Australia (A.L.G.); Schools of Physiology and Pharmacology and Clinical Sciences, Bristol University, Bristol, United Kingdom (F.E.H., S.A.H., D.W.); and Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden (T.H.)
| | - David Wynick
- Department of Dermatology (R.L.) and Laura Bassi Centre of Expertise, Department of Pediatrics (B.K.), Paracelsus Private Medical University, Salzburg, Austria; The Florey Institute of Neuroscience and Mental Health, and Florey Department of Neuroscience and Mental Health, The University of Melbourne, Melbourne, Victoria, Australia (A.L.G.); Schools of Physiology and Pharmacology and Clinical Sciences, Bristol University, Bristol, United Kingdom (F.E.H., S.A.H., D.W.); and Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden (T.H.)
| | - Tomas Hökfelt
- Department of Dermatology (R.L.) and Laura Bassi Centre of Expertise, Department of Pediatrics (B.K.), Paracelsus Private Medical University, Salzburg, Austria; The Florey Institute of Neuroscience and Mental Health, and Florey Department of Neuroscience and Mental Health, The University of Melbourne, Melbourne, Victoria, Australia (A.L.G.); Schools of Physiology and Pharmacology and Clinical Sciences, Bristol University, Bristol, United Kingdom (F.E.H., S.A.H., D.W.); and Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden (T.H.)
| | - Barbara Kofler
- Department of Dermatology (R.L.) and Laura Bassi Centre of Expertise, Department of Pediatrics (B.K.), Paracelsus Private Medical University, Salzburg, Austria; The Florey Institute of Neuroscience and Mental Health, and Florey Department of Neuroscience and Mental Health, The University of Melbourne, Melbourne, Victoria, Australia (A.L.G.); Schools of Physiology and Pharmacology and Clinical Sciences, Bristol University, Bristol, United Kingdom (F.E.H., S.A.H., D.W.); and Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden (T.H.)
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Duraffourd C, Kumala E, Anselmi L, Brecha NC, Sternini C. Opioid-induced mitogen-activated protein kinase signaling in rat enteric neurons following chronic morphine treatment. PLoS One 2014; 9:e110230. [PMID: 25302800 PMCID: PMC4193881 DOI: 10.1371/journal.pone.0110230] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Accepted: 09/18/2014] [Indexed: 01/20/2023] Open
Abstract
Opioids, acting at μ opioid receptors, are commonly used for pain management. Chronic opioid treatment induces cellular adaptations, which trigger long-term side effects, including constipation mediated by enteric neurons. We tested the hypothesis that chronic opioid treatment induces alterations of μ opioid receptor signaling in enteric neurons, which are likely to serve as mechanisms underlying opioid-induced constipation. In cultured rat enteric neurons, either untreated (naïve) or exposed to morphine for 4 days (chronic), we compared the effect of morphine and DAMGO (D-Ala2,MePhe4,Gly-ol5 enkephalin) on μ opioid receptor internalization and downstream signaling by examining the activation of the mitogen-activated protein kinase/extracellular signal-regulated kinases 1 and 2 (MAPK/ERK) pathway, cAMP accumulation and transcription factor cAMP Response Element-Binding protein (CREB) expression. μ opioid receptor internalization and MAPK/ERK phosphorylation were induced by DAMGO, but not morphine in naïve neurons, and by both opioids in chronic neurons. MAPK/ERK activation was prevented by the receptor antagonist naloxone, by blocking receptor trafficking with hypertonic sucrose, dynamin inhibitor, or neuronal transfection with mutated dynamin, and by MAPK inhibitor. Morphine and DAMGO inhibited cAMP in naïve and chronic enteric neurons, and induced desensitization of cAMP signaling. Chronic morphine treatment suppressed desensitization of cAMP and MAPK signaling, increased CREB phosphorylation through a MAPK/ERK pathway and induced delays of gastrointestinal transit, which was prevented by MAPK/ERK blockade. This study showed that opioids induce endocytosis- and dynamin-dependent MAPK/ERK activation in enteric neurons and that chronic morphine treatment triggers changes at the receptor level and downstream signaling resulting in MAPK/ERK-dependent CREB activation. Blockade of this signaling pathway prevents the development of gastrointestinal motility impairment induced by chronic morphine treatment. These findings suggest that alterations in μ opioid receptor downstream signaling including MAPK/ERK pathway in enteric neurons chronically treated with morphine contribute to the development of opioid-induced constipation.
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Affiliation(s)
- Celine Duraffourd
- CURE Digestive Diseases Research Center, Division of Digestive Diseases and Department of Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
- CURE Digestive Diseases Research Center, Division of Digestive Diseases and Department of Neurobiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Erica Kumala
- CURE Digestive Diseases Research Center, Division of Digestive Diseases and Department of Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
- CURE Digestive Diseases Research Center, Division of Digestive Diseases and Department of Neurobiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Laura Anselmi
- CURE Digestive Diseases Research Center, Division of Digestive Diseases and Department of Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Nicholas C. Brecha
- CURE Digestive Diseases Research Center, Division of Digestive Diseases and Department of Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
- CURE Digestive Diseases Research Center, Division of Digestive Diseases and Department of Neurobiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
- Veteran Administration Greater Los Angeles Healthcare System, Los Angeles, California, United States of America
| | - Catia Sternini
- CURE Digestive Diseases Research Center, Division of Digestive Diseases and Department of Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
- CURE Digestive Diseases Research Center, Division of Digestive Diseases and Department of Neurobiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
- Veteran Administration Greater Los Angeles Healthcare System, Los Angeles, California, United States of America
- * E-mail:
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