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Cui X, Zhao X, Wang Y, Yang Y, Zhang H. Glucagon‑like peptide‑1 analogue exendin‑4 modulates serotonin transporter expression in intestinal epithelial cells. Mol Med Rep 2020; 21:1934-1940. [PMID: 32319618 PMCID: PMC7057813 DOI: 10.3892/mmr.2020.10976] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 01/23/2020] [Indexed: 02/07/2023] Open
Abstract
Serotonin-selective reuptake transporter (SERT) regulates extracellular availability of serotonin (5-hydroxytryptamine; 5-HT) and participates in the pathogenesis of functional disorders. Colonic SERT expression is decreased in colonic sensitized rats, and the glucagon-like peptide-1 analogue, exendin-4, reduces visceral hypersensitivity by decreasing 5-HT levels and increasing SERT expression. The present in vitro study aimed to further investigate the effects of exendin-4 on SERT expression, and to examine the role of GLP-1 and its receptor in the regulation of 5-HT. SERT mRNA and protein expression levels were detected by reverse transcription-quantitative PCR and western blotting. A [3H]−5-HT reuptake experiment was performed in IEC-6 rat intestinal epithelial cells treated with exendin-4. Effects on the adenosine cyclophosphate (AC)/PKA pathway were examined by variously treating cells with the AC activator forskolin, the protein kinase A (PKA) inhibitor H89 and the AC inhibitor SQ22536. Exendin-4 treatment upregulated SERT expression and enhanced 5-HT reuptake in IEC-6 cells. Also, PKA activity in IEC-6 cells was increased by both exendin-4 and forskolin, whereas these effects were abolished by the pre-treatment of exendin-9, which is a GLP-1R inhibitor, SQ22536 and H89. In conclusion, exendin-4 may be associated with the upregulation of SERT expression via the AC/PKA signaling pathway.
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Affiliation(s)
- Xiufang Cui
- Department of Gastroenterology, First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, P.R. China
| | - Xiaojing Zhao
- Department of Gastroenterology, First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, P.R. China
| | - Ying Wang
- Department of Gastroenterology, First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, P.R. China
| | - Yan Yang
- Department of Gastroenterology, First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, P.R. China
| | - Hongjie Zhang
- Department of Gastroenterology, First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, P.R. China
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Ginés I, Gil-Cardoso K, D’Addario C, Falconi A, Bellia F, Blay MT, Terra X, Ardévol A, Pinent M, Beltrán-Debón R. Long-Lasting Effects of GSPE on Ileal GLP-1R Gene Expression Are Associated with a Hypomethylation of the GLP-1R Promoter in Female Wistar Rats. Biomolecules 2019; 9:biom9120865. [PMID: 31842341 PMCID: PMC6995503 DOI: 10.3390/biom9120865] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 12/03/2019] [Accepted: 12/10/2019] [Indexed: 12/14/2022] Open
Abstract
Flavonoids have been shown to modulate GLP-1 in obesity. GLP-1 induces some of its effects through the intestinal GLP-1 receptor (GLP-1R), though no data exist on how flavonoids affect this receptor. Here, we examine how a dose of grape seed proanthocyanidin extract (GSPE) with anti-obesity activity affects intestinal GLP-1R and analyze whether epigenetics play a role in the long-lasting effects of GSPE. We found that 10-day GSPE administration prior to the cafeteria diet upregulated GLP-1R mRNA in the ileum 17 weeks after the GSPE treatment. This was associated with a hypomethylation of the GLP-1R promoter near the region where the SP1 transcription factor binds. In the colon, the cafeteria diet upregulated GLP-1R without showing any GSPE effect. In conclusion, we have identified long-lasting GSPE effects on GLP-1R gene expression in the ileum that are partly mediated by hypomethylation at the gene promoter and may affect the SP1 binding factor.
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Affiliation(s)
- Iris Ginés
- MoBioFood Research Group, Universitat Rovira i Virgili, Departament de Bioquímica i Biotecnologia, c/Marcel·lí Domingo 1, 43007 Tarragona, Spain; (I.G.); (K.G.-C.); (M.T.B.); (X.T.); (A.A.); (R.B.-D.)
| | - Katherine Gil-Cardoso
- MoBioFood Research Group, Universitat Rovira i Virgili, Departament de Bioquímica i Biotecnologia, c/Marcel·lí Domingo 1, 43007 Tarragona, Spain; (I.G.); (K.G.-C.); (M.T.B.); (X.T.); (A.A.); (R.B.-D.)
| | - Claudio D’Addario
- Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, Via Renato Balzarini 1, 64100 Teramo, Italy; (C.D.); (A.F.); (F.B.)
| | - Anastasia Falconi
- Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, Via Renato Balzarini 1, 64100 Teramo, Italy; (C.D.); (A.F.); (F.B.)
| | - Fabio Bellia
- Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, Via Renato Balzarini 1, 64100 Teramo, Italy; (C.D.); (A.F.); (F.B.)
| | - M Teresa Blay
- MoBioFood Research Group, Universitat Rovira i Virgili, Departament de Bioquímica i Biotecnologia, c/Marcel·lí Domingo 1, 43007 Tarragona, Spain; (I.G.); (K.G.-C.); (M.T.B.); (X.T.); (A.A.); (R.B.-D.)
| | - Ximena Terra
- MoBioFood Research Group, Universitat Rovira i Virgili, Departament de Bioquímica i Biotecnologia, c/Marcel·lí Domingo 1, 43007 Tarragona, Spain; (I.G.); (K.G.-C.); (M.T.B.); (X.T.); (A.A.); (R.B.-D.)
| | - Anna Ardévol
- MoBioFood Research Group, Universitat Rovira i Virgili, Departament de Bioquímica i Biotecnologia, c/Marcel·lí Domingo 1, 43007 Tarragona, Spain; (I.G.); (K.G.-C.); (M.T.B.); (X.T.); (A.A.); (R.B.-D.)
| | - Montserrat Pinent
- MoBioFood Research Group, Universitat Rovira i Virgili, Departament de Bioquímica i Biotecnologia, c/Marcel·lí Domingo 1, 43007 Tarragona, Spain; (I.G.); (K.G.-C.); (M.T.B.); (X.T.); (A.A.); (R.B.-D.)
- Correspondence: ; Tel.: +34-977-55-9566; Fax: +34-977-55-8232
| | - Raúl Beltrán-Debón
- MoBioFood Research Group, Universitat Rovira i Virgili, Departament de Bioquímica i Biotecnologia, c/Marcel·lí Domingo 1, 43007 Tarragona, Spain; (I.G.); (K.G.-C.); (M.T.B.); (X.T.); (A.A.); (R.B.-D.)
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May AT, Crowe MS, Blakeney BA, Mahavadi S, Wang H, Grider JR, Murthy KS. Identification of expression and function of the glucagon-like peptide-1 receptor in colonic smooth muscle. Peptides 2019; 112:48-55. [PMID: 30508636 PMCID: PMC6342651 DOI: 10.1016/j.peptides.2018.11.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 11/07/2018] [Accepted: 11/26/2018] [Indexed: 01/01/2023]
Abstract
The insulinotropic effects of the incretin hormone, glucagon-like peptide-1 (GLP-1) are mediated via GLP-1 receptors (GLP-1R) present on pancreatic β cells. GLP-1 causes a decrease in the motility of stomach and intestine which involves both central and peripheral nervous systems. The expression and function of GLP-1R in gastrointestinal smooth muscle, however, are not clear. Muscle strips and isolated muscle cells were prepared from mouse colon and the effect of GLP-1(7-36) amide on acetylcholine (ACh)-induced contraction was measured. Muscle cells in culture were used to identify the expression of GLP-1R and the signaling pathways activated by GLP-1(7-36) amide. GLP-1R was expressed in the mucosal and non-mucosal tissue preparations derived from colon, and in smooth muscle cell cultures devoid of other cells such as enteric neurons. In colonic muscle strips, the addition of GLP-1(7-36) amide caused dose-dependent inhibition of acetylcholine-induced contractions. The effect of GLP-1(7-36) amide was partly inhibited by the neuronal blocker tetrodotoxin and nitric oxide (NO) synthase inhibitor l-NNA suggesting both NO-dependent neural and NO-independent direct effects on smooth muscle. In isolated colonic smooth muscle cells, GLP-1(7-36) amide caused an increase in Gαs activity, cAMP levels, and PKA activity, and inhibited ACh-induced contraction. The effect of GLP-1(7-36) amide on Gαs activity and cAMP levels was blocked by NF449, an inhibitor of Gαs, and the effect of GLP-1(7-36) amide on contraction was blocked by NF449 and myristoylated PKI, an inhibitor of PKA. We conclude that colonic smooth muscle cells express GLP-1R, and GLP-1(7-36) amide inhibits acetylcholine-induced contraction via GLP-1R coupled to the Gαs/cAMP/PKA pathway.
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Affiliation(s)
- Alexander T May
- Department of Physiology and Biophysics, VCU Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Box 980551, Richmond, VA, 23298, United States
| | - Molly S Crowe
- Department of Physiology and Biophysics, VCU Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Box 980551, Richmond, VA, 23298, United States
| | - Bryan A Blakeney
- Department of Physiology and Biophysics, VCU Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Box 980551, Richmond, VA, 23298, United States
| | - Sunila Mahavadi
- Department of Physiology and Biophysics, VCU Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Box 980551, Richmond, VA, 23298, United States
| | - Hongxia Wang
- Department of Physiology and Biophysics, VCU Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Box 980551, Richmond, VA, 23298, United States
| | - John R Grider
- Department of Physiology and Biophysics, VCU Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Box 980551, Richmond, VA, 23298, United States
| | - Karnam S Murthy
- Department of Physiology and Biophysics, VCU Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Box 980551, Richmond, VA, 23298, United States.
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Li ZY, Zhang N, Wen S, Zhang J, Sun XL, Fan XM, Sun YH. Decreased glucagon-like peptide-1 correlates with abdominal pain in patients with constipation-predominant irritable bowel syndrome. Clin Res Hepatol Gastroenterol 2017; 41:459-465. [PMID: 28215540 DOI: 10.1016/j.clinre.2016.12.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Revised: 10/26/2016] [Accepted: 12/15/2016] [Indexed: 02/04/2023]
Abstract
BACKGROUND AND OBJECTIVE The glucagon-like peptide-1 (GLP-1) analog, ROSE-010, plays a critical role in alleviating abdominal pain in patients with irritable bowel syndrome (IBS); however, the underling mechanism is unclear. In the present study, we determined the serum GLP-1 level in patients with constipation-predominant IBS (IBS-C). The relationship between GLP-1 and abdominal pain was investigated. In addition, the expression of the GLP-1 receptor in the colon was determined. METHODS Rectosigmoid biopsies were gathered from 38 patients with IBS-C who met the Rome III criteria, and 22 healthy controls. Abdominal pain was quantified by a validated questionnaire. Serum GLP-1 was measured by ELISA and correlated with abdominal pain scores. The presence of the GLP-1 receptor in the colonic mucosa was assessed by immunohistochemistry. RESULTS Serum GLP-1 was substantially decreased in patients with IBS-C. Decreased serum GLP-1 had a negative correlation with the abdominal pain scores. Biopsies from patients with IBS-C revealed a significant down-regulation of the GLP-1 receptor in colonic mucosa compared with control subjects. CONCLUSIONS Decreased serum GLP-1 correlates with abdominal pain in patients with IBS-C. Decreased expression of GLP-1 and GLP-1 receptor may be the basis for alleviation of abdominal pain in patients with IBS-C by ROSE-010.
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Affiliation(s)
- Zheng-Yang Li
- Department of Gastroenterology, Dalian friendship Hospital, Dalian, Liaoning 116001, PR China
| | - Na Zhang
- Department of Gastroenterology, Dalian friendship Hospital, Dalian, Liaoning 116001, PR China
| | - Shuang Wen
- Department of Gastroenterology, Dalian friendship Hospital, Dalian, Liaoning 116001, PR China
| | - Jing Zhang
- Department of Gastroenterology, Dalian friendship Hospital, Dalian, Liaoning 116001, PR China
| | - Xiu-Li Sun
- Department of Gastroenterology, Dalian friendship Hospital, Dalian, Liaoning 116001, PR China
| | - Xiao-Ming Fan
- Department of Gastroenterology, Jinshan hospital of Fudan University, Shanghai 201508, PR China.
| | - Yong-Hong Sun
- Department of Gastroenterology, Dalian friendship Hospital, Dalian, Liaoning 116001, PR China.
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Abstract
PURPOSE OF REVIEW To summarize the recent findings. RECENT FINDINGS Studies of changes in the plasma levels confirm the earlier concepts, but offer little proof of causal effect. It is increasingly realized that peptides produced in the gut have a paracrine role or an indirect effect via the gut-brain axis. Interest in prokinetic peptide agonists remains high despite the failure of two candidate drugs, but relamorelin and camicinal offer new hope. SUMMARY We review the original studies published since January 2013 on peptides produced in the gut and with an effect on gastrointestinal motility.
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Affiliation(s)
- Theo L Peeters
- Gut Peptide Laboratory, Faculty of Medicine, Catholic University of Leuven, Leuven, Belgium
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Siekmeier R, Hofmann T, Scheuch G, Pokorski M. Aerosolized GLP-1 for treatment of diabetes mellitus and irritable bowel syndrome. Adv Exp Med Biol 2014; 849:23-38. [PMID: 25427821 DOI: 10.1007/5584_2014_94] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Diabetes is a global burden and the prevalence of the disease, in particular diabetes mellitus type 2 is rapidly increasing worldwide. After introduction of insulin into clinical therapy about 90 years ago a major number of pharmaceuticals has been developed for treatment of diabetes mellitus type 2. One of these, the incretin glucagon-like peptide 1 (GLP-1), like insulin, needs subcutaneous administration causing inconvenience to patients. However, administration of GLP-1 plays also a role for treatment of irritable bowel syndrome (IBS). To improve patient convenience inhaled insulin (Exubera(®)) was developed and approved but failed market acceptance some years ago. Recently, another inhalative insulin (Afrezza(®)) received market approval and GLP-1 may serve as another candidate drug for inhalative administration. This review analyzes the current literature investigating alternative administration of GLP-1 and GLP-1 analogs focusing on inhalation. Several formulations for inhalative administration of GLP-1 and analogs were investigated in animal studies, whereas there are only few clinical data. However, feasibility of GLP-1 inhalation has been shown and should be further investigated as such type of drug administration may serve for improvement of therapy in patients with diabetes mellitus or irritable bowel syndrome.
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Affiliation(s)
- Rüdiger Siekmeier
- Drug Regulatory Affairs, Pharmaceutical Institute, Bonn University, An der Immenburg 4, 53121, Bonn, Germany,
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