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Grondin JA, Khan WI. Emerging Roles of Gut Serotonin in Regulation of Immune Response, Microbiota Composition and Intestinal Inflammation. J Can Assoc Gastroenterol 2024; 7:88-96. [PMID: 38314177 PMCID: PMC10836984 DOI: 10.1093/jcag/gwad020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2024] Open
Abstract
Although the exact etiology of inflammatory bowel diseases (IBD) is unknown, studies have shown that dysregulated immune responses, genetic factors, gut microbiota, and environmental factors contribute to their pathogenesis. Intriguingly, serotonin (5-hydroxytryptamine or 5-HT) seems to be a molecule with increasingly strong implications in the pathogenesis of intestinal inflammation, affecting host physiology, including autophagy and immune responses, as well as microbial composition and function. 5-HT may also play a role in mediating how environmental effects impact outcomes in IBD. In this review, we aim to explore the production and important functions of 5-HT, including its impact on the gut. In addition, we highlight the bidirectional impacts of 5-HT on the immune system, the gut microbiota, and the process of autophagy and how these effects contribute to the manifestation of intestinal inflammation. We also explore recent findings connecting 5-HT signalling and the influence of environmental factors, particularly diet, in the pathogenesis of IBD. Ultimately, we explore the pleiotropic effects of this ancient molecule on biology and health in the context of intestinal inflammation.
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Affiliation(s)
- Jensine A Grondin
- Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, ON, Canada
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada
| | - Waliul I Khan
- Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, ON, Canada
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada
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Akram N, Faisal Z, Irfan R, Shah YA, Batool SA, Zahid T, Zulfiqar A, Fatima A, Jahan Q, Tariq H, Saeed F, Ahmed A, Asghar A, Ateeq H, Afzaal M, Khan MR. Exploring the serotonin-probiotics-gut health axis: A review of current evidence and potential mechanisms. Food Sci Nutr 2024; 12:694-706. [PMID: 38370053 PMCID: PMC10867509 DOI: 10.1002/fsn3.3826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 10/24/2023] [Accepted: 11/01/2023] [Indexed: 02/20/2024] Open
Abstract
Modulatory effects of serotonin (5-Hydroxytryptamine [5-HT]) have been seen in hepatic, neurological/psychiatric, and gastrointestinal (GI) disorders. Probiotics are live microorganisms that confer health benefits to their host. Recent research has suggested that probiotics can promote serotonin signaling, a crucial pathway in the regulation of mood, cognition, and other physiological processes. Reviewing the literature, we find that peripheral serotonin increases nutrient uptake and storage, regulates the composition of the gut microbiota, and is involved in mediating neuronal disorders. This review explores the mechanisms underlying the probiotic-mediated increase in serotonin signaling, highlighting the role of gut microbiota in the regulation of serotonin production and the modulation of neurotransmitter receptors. Additionally, this review discusses the potential clinical implications of probiotics as a therapeutic strategy for disorders associated with altered serotonin signaling, such as GI and neurological disorders. Overall, this review demonstrates the potential of probiotics as a promising avenue for the treatment of serotonin-related disorders and signaling of serotonin.
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Affiliation(s)
- Noor Akram
- Department of Food and NutritionGovernment College University FaisalabadFaisalabadPakistan
| | - Zargham Faisal
- Department of Human NutritionBahauddin Zakariya University MultanMultanPakistan
| | - Rushba Irfan
- Faculty of Food Nutrition & Home SciencesUniversity of AgricultureFaisalabadPakistan
| | - Yasir Abbas Shah
- Natural & Medical Science Research CenterUniversity of NizwaNizwaOman
| | - Syeda Ayesha Batool
- Department of Food ScienceGovernment College University FaisalabadFaisalabadPakistan
| | - Toobaa Zahid
- Department of Food and NutritionGovernment College University FaisalabadFaisalabadPakistan
| | - Aqsa Zulfiqar
- Department of Food and NutritionGovernment College University FaisalabadFaisalabadPakistan
| | - Areeja Fatima
- National Institute of Food Science & TechnologyUniversity of AgricultureFaisalabadPakistan
| | - Qudsia Jahan
- Department of Food and NutritionGovernment College University FaisalabadFaisalabadPakistan
| | - Hira Tariq
- Department of Food and NutritionGovernment College University FaisalabadFaisalabadPakistan
| | - Farhan Saeed
- Department of Food ScienceGovernment College University FaisalabadFaisalabadPakistan
| | - Aftab Ahmed
- Department of Nutritional SciencesGovernment College University FaisalabadFaisalabadPakistan
| | - Aasma Asghar
- Department of Nutritional SciencesGovernment College University FaisalabadFaisalabadPakistan
| | - Huda Ateeq
- Department of Food ScienceGovernment College University FaisalabadFaisalabadPakistan
| | - Muhammad Afzaal
- Department of Food ScienceGovernment College University FaisalabadFaisalabadPakistan
| | - Mahbubur Rahman Khan
- Department of Food Processing and PreservationHajee Mohammad Danesh Science & Technology UniversityDinajpurBangladesh
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Xiao S, Xie W, Zhang Y, Pan Y, Lei L. The Immune Landscape and Molecular Subtypes of Pediatric Crohn's Disease: Results from In Silico Analysis. J Pers Med 2023; 13:jpm13040571. [PMID: 37108957 PMCID: PMC10142949 DOI: 10.3390/jpm13040571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2023] [Revised: 03/02/2023] [Accepted: 03/03/2023] [Indexed: 04/29/2023] Open
Abstract
Pediatric Crohn's disease (CD) presents a distinct phenotype from adult-onset disease. A dysregulated immune response is critical in CD pathogenesis; thus, it is clinically important to describe immune cell alterations and to identify a new molecular classification for pediatric CD. To this end, in this study, a RNA-seq derived dataset GSE101794-which contains the expression profiles of 254 treatment-naïve pediatric CD samples, including CIBERSORTx and weighted gene-co-expression network analysis (WGCNA)-were performed to estimate the ratio of immune cells and to identify modules and genes related to specific immune cell infiltration, respectively. Hub genes derived from WGCNA were further employed to create a molecular classification using unsupervised K-means clustering. In the pediatric CD samples, it was found that M2 macrophages, CD4+ memory resting T cells, CD8+ T cells, and resting mast cells were the most prominent immune cells in intestinal tissues. Then, 985 up-regulated genes and 860 down-regulated genes were identified in samples with high immune cell infiltration. Of these differential genes, 10 hub genes (APOA1, CYB5A, XPNPEP2, SLC1A7, SLC4A6, LIPE, G6PC, AGXT2, SLC13A1, and SOAT2) were associated with CD8+T cell infiltration. Clinically, the higher expression of these 10 hub genes was strongly associated with an earlier age of CD onset and colonic-type CD. Furthermore, based on these key genes, pediatric CD could be classified into three molecular subtypes, displaying a different immune landscape. Altogether, this in silico analysis provides a novel insight into the immune signature of pediatric CD, and a new classification of pediatric CD is presented, which may help us develop more personalized disease management and treatments for pediatric CD.
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Affiliation(s)
- Shiyu Xiao
- Department of Gastroenterology, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu 610072, China
- School of Medicine, University of Electronic Science and Technology of China, Chengdu 100034, China
| | - Wenhui Xie
- Department of Rheumatology and Clinical Immunology, Peking University First Hospital, Beijing 100034, China
| | - Yinghui Zhang
- Department of Gastroenterology, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu 610072, China
- School of Medicine, University of Electronic Science and Technology of China, Chengdu 100034, China
| | - Yan Pan
- Department of Gastroenterology, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu 610072, China
- School of Medicine, University of Electronic Science and Technology of China, Chengdu 100034, China
| | - Lei Lei
- Department of Gastroenterology, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu 610072, China
- School of Medicine, University of Electronic Science and Technology of China, Chengdu 100034, China
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Wang A, Li P, Ma F, Li X, Mu G, Tuo Y. Mixed Lactiplantibacillus plantarum strains alleviated DSS-induced intestinal inflammation of Balb/c mice via the 5-HT/5-HT7R/NF-κB signaling pathway. J Funct Foods 2023. [DOI: 10.1016/j.jff.2023.105435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023] Open
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Chen YM, Li Y, Wang X, Wang ZL, Hou JJ, Su S, Zhong WL, Xu X, Zhang J, Wang BM, Wang YM. Effect of Bacillus subtilis, Enterococcus faecium, and Enterococcus faecalis supernatants on serotonin transporter expression in cells and tissues. World J Gastroenterol 2022; 28:532-546. [PMID: 35316963 PMCID: PMC8905020 DOI: 10.3748/wjg.v28.i5.532] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 10/16/2021] [Accepted: 01/06/2022] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Bacillus subtilis (B. subtilis), Enterococcus faecium (E. faecium), and Enterococcus faecalis (E. faecalis) are probiotics that are widely used in the clinical treatment of irritable bowel syndrome (IBS). Whether the supernatants of these three probiotics can improve gastrointestinal sensation and movement by regulating the serotonin transporter (SERT) expression needs to be clarified.
AIM To investigate whether B. subtilis, E. faecium, and E. faecalis supernatants can upregulate SERT expression in vitro and in vivo.
METHODS Caco-2 and HT-29 cells were stimulated with probiotic culture supernatants for 12 and 24 h, respectively. A male Sprague-Dawley rat model of post-infectious irritable bowel syndrome (PI-IBS) was established and the rats were treated with phosphate-buffered saline (group A) and three probiotics culture supernatants (groups B, C, and D) for 4 wk. The levels of SERT were detected by quantitative PCR and western blotting.
RESULTS The levels of SERT at post-treatment 12 and 24 h were significantly elevated in Caco-2 cells treated with B. subtilis supernatant compared with those in the control group (aP < 0.05). Those levels were markedly upregulated in Caco-2 cells stimulated with E. faecium and E. faecalis supernatants at 24 h (aP < 0.05). In addition, SERT expression in groups B, C, and D was significantly higher than that in group A in the 2nd wk (aP < 0.05). Increased SERT expression was only found in group D in the 3rd wk (aP < 0.05). However, there was no significant difference in SERT expression between the groups in the last week (P > 0.05).
CONCLUSION The supernatants of B. subtilis, E. faecium, and E. faecalis can upregulate SERT expression in intestinal epithelial cells and the intestinal tissues in the rat model of PI-IBS.
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Affiliation(s)
- Yi-Ming Chen
- Department of Gastroenterology and Hepatology, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Ying Li
- Department of Gastroenterology and Hepatology, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Xin Wang
- Department of Gastroenterology and Hepatology, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Ze-Lan Wang
- Department of Gastroenterology and Hepatology, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Jun-Jie Hou
- Department of Gastroenterology and Hepatology, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Shuai Su
- Department of Gastroenterology and Hepatology, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Wei-Long Zhong
- Department of Gastroenterology and Hepatology, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Xin Xu
- Department of Gastroenterology and Hepatology, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Jie Zhang
- Department of Gastroenterology and Hepatology, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Bang-Mao Wang
- Department of Gastroenterology and Hepatology, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Yu-Ming Wang
- Department of Gastroenterology and Hepatology, Tianjin Medical University General Hospital, Tianjin 300052, China
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Engevik M, Ruan W, Visuthranukul C, Shi Z, Engevik KA, Engevik AC, Fultz R, Schady DA, Spinler JK, Versalovic J. Limosilactobacillus reuteri ATCC 6475 metabolites upregulate the serotonin transporter in the intestinal epithelium. Benef Microbes 2021; 12:583-599. [PMID: 34550056 DOI: 10.3920/bm2020.0216] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The serotonin transporter (SERT) readily takes up serotonin (5-HT), thereby regulating the availability of 5-HT within the intestine. In the absence of SERT, 5-HT remains in the interstitial space and has the potential to aberrantly activate the many 5-HT receptors distributed on the epithelium, immune cells and enteric neurons. Perturbation of SERT is common in many gastrointestinal disorders as well as mouse models of colitis. Select commensal microbes regulate intestinal SERT levels, but the mechanism of this regulation is poorly understood. Additionally, ethanol upregulates SERT in the brain and dendritic cells, but its effects in the intestine have never been examined. We report that the intestinal commensal microbe Limosilactobacillus (previously classified as Lactobacillus) reuteri ATCC PTA 6475 secretes 83.4 mM ethanol. Consistent with the activity of L. reuteri alcohol dehydrogenases, we found that L. reuteri tolerated various levels of ethanol. Application of L. reuteri conditioned media or exogenous ethanol to human colonic T84 cells was found to upregulate SERT at the level of mRNA. A 4-(4-(dimethylamino) phenyl)-1-methylpyridinium (APP+) uptake assay confirmed the functional activity of SERT. These findings were mirrored in mouse colonic organoids, where L. reuteri metabolites and ethanol were found to upregulate SERT at the apical membrane. Finally, in a trinitrobenzene sulphonic acid model of acute colitis, we observed that mice treated with L. reuteri maintained SERT at the colon membrane compared with mice receiving phosphate buffered saline vehicle control. These data suggest that L. reuteri metabolites, including ethanol, can upregulate SERT and may be beneficial for maintaining intestinal homeostasis with respect to serotonin signalling.
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Affiliation(s)
- M Engevik
- Department of Pathology & Immunology, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX 77030, USA
- Department of Regenerative Medicine & Cell Biology, Medical University of South Carolina, 173 Ashely Ave, BSB 626, Charleston, SC 29425, USA
| | - W Ruan
- Department of Pediatrics, Baylor College of Medicine, 6701 Fannin Street, Houston, TX 77030, USA
- Section of Gastroenterology, Hepatology, and Nutrition, Texas Children's Hospital, 6701 Fannin St, Houston, TX 77030, USA
| | - C Visuthranukul
- Department of Pathology & Immunology, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX 77030, USA
- Pediatric Nutrition Research Unit, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Z Shi
- Department of Pathology & Immunology, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX 77030, USA
- Department of Pathology, Texas Children's Hospital, 6621 Fannin St, Houston, TX 77030, USA
| | - K A Engevik
- Department of Molecular Virology & Microbiology, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX 7703, USA
| | - A C Engevik
- Departments of Surgery, Vanderbilt University Medical Center, 1211 Medical Center Dr, Nashville, TN 37232, USA
| | - R Fultz
- Department of Neuroscience, Cell Biology, and Anatomy, University of Texas Medical Branch, 301 University Boulevard, Galveston, TX 77555-0625, USA
| | - D A Schady
- Department of Pathology & Immunology, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX 77030, USA
- Department of Pathology, Texas Children's Hospital, 6621 Fannin St, Houston, TX 77030, USA
| | - J K Spinler
- Department of Pathology & Immunology, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX 77030, USA
- Department of Pathology, Texas Children's Hospital, 6621 Fannin St, Houston, TX 77030, USA
| | - J Versalovic
- Department of Pathology & Immunology, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX 77030, USA
- Department of Pathology, Texas Children's Hospital, 6621 Fannin St, Houston, TX 77030, USA
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Enteric Microbiota-Mediated Serotonergic Signaling in Pathogenesis of Irritable Bowel Syndrome. Int J Mol Sci 2021; 22:ijms221910235. [PMID: 34638577 PMCID: PMC8508930 DOI: 10.3390/ijms221910235] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 09/18/2021] [Accepted: 09/19/2021] [Indexed: 12/12/2022] Open
Abstract
Irritable bowel syndrome (IBS) is a chronic functional disorder that affects the gastrointestinal tract. Details regarding the pathogenesis of IBS remain largely unknown, though the dysfunction of the brain-gut-microbiome (BGM) axis is a major etiological factor, in which neurotransmitters serve as a key communication tool between enteric microbiota and the brain. One of the most important neurotransmitters in the pathology of IBS is serotonin (5-HT), as it influences gastrointestinal motility, pain sensation, mucosal inflammation, immune responses, and brain activity, all of which shape IBS features. Genome-wide association studies discovered susceptible genes for IBS in serotonergic signaling pathways. In clinical practice, treatment strategies targeting 5-HT were effective for a certain portion of IBS cases. The synthesis of 5-HT in intestinal enterochromaffin cells and host serotonergic signaling is regulated by enteric resident microbiota. Dysbiosis can trigger IBS development, potentially through aberrant 5-HT signaling in the BGM axis; thus, the manipulation of the gut microbiota may be an alternative treatment strategy. However, precise information regarding the mechanisms underlying the microbiota-mediated intestinal serotonergic pathway related to the pathogenesis of IBS remains unclear. The present review summarizes current knowledge and recent progress in understanding microbiome–serotonin interaction in IBS cases.
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Taverniti V, Cesari V, Gargari G, Rossi U, Biddau C, Lecchi C, Fiore W, Arioli S, Toschi I, Guglielmetti S. Probiotics Modulate Mouse Gut Microbiota and Influence Intestinal Immune and Serotonergic Gene Expression in a Site-Specific Fashion. Front Microbiol 2021; 12:706135. [PMID: 34539604 PMCID: PMC8441017 DOI: 10.3389/fmicb.2021.706135] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Accepted: 07/23/2021] [Indexed: 12/12/2022] Open
Abstract
Probiotic microorganisms may benefit the host by influencing diverse physiological processes, whose nature and underlying mechanisms are still largely unexplored. Animal models are a unique tool to understand the complexity of the interactions between probiotic microorganisms, the intestinal microbiota, and the host. In this regard, in this pilot study, we compared the effects of 5-day administration of three different probiotic bacterial strains (Bifidobacterium bifidum MIMBb23sg, Lactobacillus helveticus MIMLh5, and Lacticaseibacillus paracasei DG) on three distinct murine intestinal sites (ileum, cecum, and colon). All probiotics preferentially colonized the cecum and colon. In addition, probiotics reduced in the ileum and increased in the cecum and colon the relative abundance of numerous bacterial taxonomic units. MIMBb23sg and DG increased the inducible nitric oxide synthase (iNOS) in the ileum, which is involved in epithelial homeostasis. In addition, MIMBb23sg upregulated cytokine IL-10 in the ileum and downregulated the cyclooxygenase COX-2 in the colon, suggesting an anti-inflammatory/regulatory activity. MIMBb23sg significantly affected the expression of the main gene involved in serotonin synthesis (TPH1) and the gene coding for the serotonin reuptake protein (SERT) in the ileum and colon, suggesting a potential propulsive effect toward the distal part of the gut, whereas the impact of MIMLh5 and DG on serotonergic genes suggested an effect toward motility control. The three probiotics decreased the expression of the permeability marker zonulin in gut distal sites. This preliminary in vivo study demonstrated the safety of the tested probiotic strains and their common ability to modulate the intestinal microbiota. The probiotics affected host gene expression in a strain-specific manner. Notably, the observed effects in the gut were site dependent. This study provides a rationale for investigating the effects of probiotics on the serotonergic system, which is a topic still widely unexplored.
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Affiliation(s)
- Valentina Taverniti
- Department of Food, Environmental and Nutritional Sciences, Università degli Studi di Milano, Milan, Italy
| | - Valentina Cesari
- Department of Agricultural and Environmental Sciences, Università degli Studi di Milano, Milan, Italy
| | - Giorgio Gargari
- Department of Food, Environmental and Nutritional Sciences, Università degli Studi di Milano, Milan, Italy
| | - Umberto Rossi
- Department of Food, Environmental and Nutritional Sciences, Università degli Studi di Milano, Milan, Italy
| | - Cristina Biddau
- Department of Food, Environmental and Nutritional Sciences, Università degli Studi di Milano, Milan, Italy
| | - Cristina Lecchi
- Department of Veterinary Medicine, Università degli Studi di Milano, Milan, Italy
| | | | - Stefania Arioli
- Department of Food, Environmental and Nutritional Sciences, Università degli Studi di Milano, Milan, Italy
| | - Ivan Toschi
- Department of Agricultural and Environmental Sciences, Università degli Studi di Milano, Milan, Italy
| | - Simone Guglielmetti
- Department of Food, Environmental and Nutritional Sciences, Università degli Studi di Milano, Milan, Italy
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Koopman N, Katsavelis D, Hove AST, Brul S, de Jonge WJ, Seppen J. The Multifaceted Role of Serotonin in Intestinal Homeostasis. Int J Mol Sci 2021; 22:9487. [PMID: 34502396 PMCID: PMC8431144 DOI: 10.3390/ijms22179487] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 08/26/2021] [Accepted: 08/27/2021] [Indexed: 12/12/2022] Open
Abstract
The monoamine serotonin, 5-hydroxytryptamine (5-HT), is a remarkable molecule with conserved production in prokaryotes and eukaryotes and a wide range of functions. In the gastrointestinal tract, enterochromaffin cells are the most important source for 5-HT production. Some intestinal bacterial species are also able to produce 5-HT. Besides its role as a neurotransmitter, 5-HT acts on immune cells to regulate their activation. Several lines of evidence indicate that intestinal 5-HT signaling is altered in patients with inflammatory bowel disease. In this review, we discuss the current knowledge on the production, secretion, and signaling of 5-HT in the intestine. We present an inventory of intestinal immune and epithelial cells that respond to 5-HT and describe the effects of these signaling processes on intestinal homeostasis. Further, we detail the mechanisms by which 5-HT could affect inflammatory bowel disease course and describe the effects of interventions that target intestinal 5-HT signaling.
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Affiliation(s)
- Nienke Koopman
- Swammerdam Institute for Life Sciences (SILS), University of Amsterdam, 1098XH Amsterdam, The Netherlands; (N.K.); (D.K.); (S.B.)
| | - Drosos Katsavelis
- Swammerdam Institute for Life Sciences (SILS), University of Amsterdam, 1098XH Amsterdam, The Netherlands; (N.K.); (D.K.); (S.B.)
| | - Anne S. ten Hove
- Tytgat Institute for Liver and Intestinal Research, Amsterdam University Medical Centers, Location AMC, 1105BK Amsterdam, The Netherlands; (A.S.t.H.); (W.J.d.J.)
| | - Stanley Brul
- Swammerdam Institute for Life Sciences (SILS), University of Amsterdam, 1098XH Amsterdam, The Netherlands; (N.K.); (D.K.); (S.B.)
| | - Wouter J. de Jonge
- Tytgat Institute for Liver and Intestinal Research, Amsterdam University Medical Centers, Location AMC, 1105BK Amsterdam, The Netherlands; (A.S.t.H.); (W.J.d.J.)
| | - Jurgen Seppen
- Tytgat Institute for Liver and Intestinal Research, Amsterdam University Medical Centers, Location AMC, 1105BK Amsterdam, The Netherlands; (A.S.t.H.); (W.J.d.J.)
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Liu N, Sun S, Wang P, Sun Y, Hu Q, Wang X. The Mechanism of Secretion and Metabolism of Gut-Derived 5-Hydroxytryptamine. Int J Mol Sci 2021; 22:ijms22157931. [PMID: 34360695 PMCID: PMC8347425 DOI: 10.3390/ijms22157931] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 06/16/2021] [Accepted: 06/19/2021] [Indexed: 12/17/2022] Open
Abstract
Serotonin, also known as 5-hydroxytryptamine (5-HT), is a metabolite of tryptophan and is reported to modulate the development and neurogenesis of the enteric nervous system, gut motility, secretion, inflammation, sensation, and epithelial development. Approximately 95% of 5-HT in the body is synthesized and secreted by enterochromaffin (EC) cells, the most common type of neuroendocrine cells in the gastrointestinal (GI) tract, through sensing signals from the intestinal lumen and the circulatory system. Gut microbiota, nutrients, and hormones are the main factors that play a vital role in regulating 5-HT secretion by EC cells. Apart from being an important neurotransmitter and a paracrine signaling molecule in the gut, gut-derived 5-HT was also shown to exert other biological functions (in autism and depression) far beyond the gut. Moreover, studies conducted on the regulation of 5-HT in the immune system demonstrated that 5-HT exerts anti-inflammatory and proinflammatory effects on the gut by binding to different receptors under intestinal inflammatory conditions. Understanding the regulatory mechanisms through which 5-HT participates in cell metabolism and physiology can provide potential therapeutic strategies for treating intestinal diseases. Herein, we review recent evidence to recapitulate the mechanisms of synthesis, secretion, regulation, and biofunction of 5-HT to improve the nutrition and health of humans.
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Affiliation(s)
- Ning Liu
- Key Laboratory of Precision Nutrition and Food Quality, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China;
- Department of Nutrition and Health, China Agricultural University, Beijing 100193, China; (P.W.); (Y.S.); (Q.H.)
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, China Agricultural University, Beijing 100193, China
| | - Shiqiang Sun
- Department of Gastroenterology and Hepatology, University Medical Center Groningen, University of Groningen, 9713ZG Groningen, The Netherlands;
- Department of Genetics, University Medical Center Groningen, University of Groningen, 9713ZG Groningen, The Netherlands
| | - Pengjie Wang
- Department of Nutrition and Health, China Agricultural University, Beijing 100193, China; (P.W.); (Y.S.); (Q.H.)
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, China Agricultural University, Beijing 100193, China
| | - Yanan Sun
- Department of Nutrition and Health, China Agricultural University, Beijing 100193, China; (P.W.); (Y.S.); (Q.H.)
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, China Agricultural University, Beijing 100193, China
| | - Qingjuan Hu
- Department of Nutrition and Health, China Agricultural University, Beijing 100193, China; (P.W.); (Y.S.); (Q.H.)
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, China Agricultural University, Beijing 100193, China
| | - Xiaoyu Wang
- Key Laboratory of Precision Nutrition and Food Quality, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China;
- Correspondence: ; Tel.: +86-10-6273-8589
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Grifka-Walk HM, Jenkins BR, Kominsky DJ. Amino Acid Trp: The Far Out Impacts of Host and Commensal Tryptophan Metabolism. Front Immunol 2021; 12:653208. [PMID: 34149693 PMCID: PMC8213022 DOI: 10.3389/fimmu.2021.653208] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Accepted: 05/11/2021] [Indexed: 12/12/2022] Open
Abstract
Tryptophan (Trp) is an essential amino acid primarily derived from the diet for use by the host for protein synthesis. The intestinal tract is lined with cells, both host and microbial, that uptake and metabolize Trp to also generate important signaling molecules. Serotonin (5-HT), kynurenine and its downstream metabolites, and to a lesser extent other neurotransmitters are generated by the host to signal onto host receptors and elicit physiological effects. 5-HT production by neurons in the CNS regulates sleep, mood, and appetite; 5-HT production in the intestinal tract by enterochromaffin cells regulates gastric motility and inflammation in the periphery. Kynurenine can signal onto the aryl hydrocarbon receptor (AHR) to elicit pleiotropic responses from several cell types including epithelial and immune cells, or can be further metabolized into bioactive molecules to influence neurodegenerative disease. There is a remarkable amount of cross-talk with the microbiome with regard to tryptophan metabolites as well. The gut microbiome can regulate the production of host tryptophan metabolites and can use dietary or recycled trp to generate bioactive metabolites themselves. Trp derivatives like indole are able to signal onto xenobiotic receptors, including AHR, to elicit tolerogenic effects. Here, we review studies that demonstrate that tryptophan represents a key intra-kingdom signaling molecule.
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Affiliation(s)
- Heather M Grifka-Walk
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, United States
| | - Brittany R Jenkins
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, United States
| | - Douglas J Kominsky
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, United States
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12
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Yaghoubfar R, Behrouzi A, Zare Banadkoki E, Ashrafian F, Lari A, Vaziri F, Nojoumi SA, Fateh A, Khatami S, Siadat SD. Effect of Akkermansia muciniphila, Faecalibacterium prausnitzii, and Their Extracellular Vesicles on the Serotonin System in Intestinal Epithelial Cells. Probiotics Antimicrob Proteins 2021; 13:1546-1556. [PMID: 33852147 DOI: 10.1007/s12602-021-09786-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/07/2021] [Indexed: 02/07/2023]
Abstract
The gastrointestinal (GI) tract is an essential reservoir of serotonin or 5-hydroxytryptamine (5-HT), which possesses a set of bacterial species communities. Intestinal microbiota has the ability to modulate the host's serotonin system. In this regard, we evaluated the effect of Akkermansia muciniphila and Faecalibacterium prausnitzii along with their extracellular vesicles (EVs) on serotonin system-related genes in human epithelial colorectal adenocarcinoma (Caco-2) cells. The differentiated Caco-2 cells were treated with A. muciniphila and F. prausnitzii with the multiplicity of infection ratio of 1 and 10 and the EV concentration of 1 μg/mL and 50 μg/mL, respectively. After 24 h, the serotonin level was quantified using an ELISA kit and also the gene expression of serotonin system-related genes was examined using the quantitative real-time PCR method. According to the results, treatment with A. muciniphila and F. prausnitzii-derived EVs increased the serotonin level, while none of the bacteria could affect the serotonin level in the Caco-2 cells. Both bacteria had significant effects on the mRNA expression of serotonin system-related genes in the Caco-2 cells. Moreover, we observed that A. muciniphila and F. prausnitzii-derived EVs could impact the expression of major genes involved in the serotonin system. Our findings showed that A. muciniphila and F. prausnitzii along with their EVs could modulate serotonin system-related genes; hence, they may be useful in microbiota modulation therapies to maintain the homeostasis of the serotonin system.
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Affiliation(s)
- Rezvan Yaghoubfar
- Department of Mycobacteriology and Pulmonary Research, Pasteur Institute of Iran, Tehran, Iran.,Microbiology Research Center (MRC), Pasteur Institute of Iran, Tehran, Iran
| | - Ava Behrouzi
- Department of Mycobacteriology and Pulmonary Research, Pasteur Institute of Iran, Tehran, Iran.,Microbiology Research Center (MRC), Pasteur Institute of Iran, Tehran, Iran
| | | | - Fatemeh Ashrafian
- Department of Mycobacteriology and Pulmonary Research, Pasteur Institute of Iran, Tehran, Iran.,Microbiology Research Center (MRC), Pasteur Institute of Iran, Tehran, Iran
| | - Arezou Lari
- Systems Biomedicine Unit, Pasteur Institute of Iran, Tehran, Iran
| | - Farzam Vaziri
- Department of Mycobacteriology and Pulmonary Research, Pasteur Institute of Iran, Tehran, Iran.,Microbiology Research Center (MRC), Pasteur Institute of Iran, Tehran, Iran
| | - Seyed Ali Nojoumi
- Department of Mycobacteriology and Pulmonary Research, Pasteur Institute of Iran, Tehran, Iran.,Microbiology Research Center (MRC), Pasteur Institute of Iran, Tehran, Iran
| | - Abolfazl Fateh
- Department of Mycobacteriology and Pulmonary Research, Pasteur Institute of Iran, Tehran, Iran. .,Microbiology Research Center (MRC), Pasteur Institute of Iran, Tehran, Iran.
| | - Shohreh Khatami
- Department of Biochemistry, Pasteur Institute of Iran, Tehran, Iran.
| | - Seyed Davar Siadat
- Department of Mycobacteriology and Pulmonary Research, Pasteur Institute of Iran, Tehran, Iran.,Microbiology Research Center (MRC), Pasteur Institute of Iran, Tehran, Iran
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13
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Suga N, Murakami A, Arimitsu H, Nakamura T, Nakamura Y, Kato Y. Luteolin suppresses 5-hydroxytryptamine elevation in stimulated RBL-2H3 cells and experimental colitis mice. J Clin Biochem Nutr 2021; 69:20-27. [PMID: 34376910 PMCID: PMC8325766 DOI: 10.3164/jcbn.20-192] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 12/20/2020] [Indexed: 01/11/2023] Open
Abstract
Increased 5-hydroxytryptamine may be associated with the development and progression of inflammatory bowel disease. In this study, we examined the suppressive effect of flavonoids on the increased intra- and extracellular 5-hydroxytryptamine levels in rat mast RBL-2H3 cells, known to produce 5-hydroxytryptamine by the phorbol 12-myristate 13-acetate stimulation. Among the flavonoids examined, luteolin and quercetin significantly reduced the cellular 5-hydroxytryptamine concentration. Gene and protein expression analyses revealed that luteolin significantly suppressed cellular tryptophan hydroxylase 1 expression induced by phorbol 12-myristate 13-acetate stimulation. Mitogen-activated protein kinase/extracellular signal-regulated kinase signaling was also suppressed by luteolin, suggesting that this pathway is one of targets of 5-hydroxytryptamine modulation by luteolin. An in vivo experimental colitis model was prepared by administering 2.5% dextran sodium sulfate in drinking water to C57BL/6 mice for seven days. The ingestion of 0.1% dietary luteolin suppressed the increasing 5-hydroxytryptamine in the colorectal mucosa. In conclusion, luteolin possesses a suppressive effect on extensive 5-hydroxytryptamine formation in both experimental RBL-2H3 cells and colitis models.
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Affiliation(s)
- Naoko Suga
- Graduate School of Human Science and Environment, University of Hyogo, Himeji, Hyogo 670-0092, Japan
| | - Akira Murakami
- Graduate School of Human Science and Environment, University of Hyogo, Himeji, Hyogo 670-0092, Japan.,Research Institute for Food and Nutritional Sciences, University of Hyogo, Himeji, Hyogo 670-0092, Japan
| | - Hideyuki Arimitsu
- Graduate School of Human Science and Environment, University of Hyogo, Himeji, Hyogo 670-0092, Japan.,Research Institute for Food and Nutritional Sciences, University of Hyogo, Himeji, Hyogo 670-0092, Japan
| | - Toshiyuki Nakamura
- Graduate School of Environmental and Life Science, Okayama University, Okayama, Okayama 700-8530, Japan
| | - Yoshimasa Nakamura
- Graduate School of Environmental and Life Science, Okayama University, Okayama, Okayama 700-8530, Japan
| | - Yoji Kato
- Graduate School of Human Science and Environment, University of Hyogo, Himeji, Hyogo 670-0092, Japan.,Research Institute for Food and Nutritional Sciences, University of Hyogo, Himeji, Hyogo 670-0092, Japan
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14
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Yaghoubfar R, Behrouzi A, Fateh A, Nojoumi SA, Vaziri F, Khatami S, Siadat SD. Effects of Akkermansia muciniphila and Faecalibacterium prausnitzii on serotonin transporter expression in intestinal epithelial cells. J Diabetes Metab Disord 2021; 20:1-5. [PMID: 34222056 DOI: 10.1007/s40200-020-00539-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/29/2019] [Revised: 04/29/2020] [Accepted: 05/06/2020] [Indexed: 02/06/2023]
Abstract
Purpose The highest level of peripheral serotonin in the body can be found in the gastrointestinal (GI) tract as its reservoir. There is complete interaction between human gastrointestinal microbiota and serotonin system. Serotonin in the GI is transferred by serotonin transporters (SERTs), which play a crucial role in the bioavailability of serotonin in the GI. SERT impairment is associated with the pathology of GI disorders. It is known that intestinal microbiota can regulate the SERT function. Therefore, it may be useful to regulate of SERT expression by modulation of microbiota and improvement of intestinal motility and GI sensation. In this study, we aimed to evaluate the effects of two next-generation probiotics, including Akkermansia muciniphila and Faecalibacterium prausnitzii, and their supernatants on SERT gene expression in human epithelial colorectal adenocarcinoma cells (Caco-2). Methods The Caco-2 cells were treated with multiplicity of infection (MOI) ratio of 100 of A. muciniphila and F. prausnitzii, as well as their supernatants. After 24 h, SERT gene expression was examined by quantitative real-time polymerase chain reaction (qRT-PCR) assay. Results A. muciniphila up-regulated the SERT mRNA level by 3.01 folds, compared to the control group. F. prausnitzii, similar to A. muciniphila, increased the expression of SERT gene in Caco-2 cells by 3.43 folds (P < 0.001). Moreover, the supernatants of A. muciniphila and F. prausnitzii significantly up-regulated the expression of SERT gene in the cell line by 2.4 and 5.7 folds, respectively, compared to the control group (P < 0.001). Conclusions The present results showed that A. muciniphila and F. prausnitzii, as well as their supernatants, increased the expression of SERT gene in Caco-2 cells. Therefore, they might be helpful in the microbiota-modulating treatment of inflammatory bowel diseases.
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Affiliation(s)
- Rezvan Yaghoubfar
- Department of Mycobacteriology and Pulmonary Research, Pasteur Institute of Iran, Tehran, Iran.,Microbiology Research Center (MRC), Pasteur Institute of Iran, Tehran, Iran
| | - Ava Behrouzi
- Department of Mycobacteriology and Pulmonary Research, Pasteur Institute of Iran, Tehran, Iran.,Microbiology Research Center (MRC), Pasteur Institute of Iran, Tehran, Iran
| | - Abolfazl Fateh
- Department of Mycobacteriology and Pulmonary Research, Pasteur Institute of Iran, Tehran, Iran.,Microbiology Research Center (MRC), Pasteur Institute of Iran, Tehran, Iran
| | - Seyed Ali Nojoumi
- Department of Mycobacteriology and Pulmonary Research, Pasteur Institute of Iran, Tehran, Iran.,Microbiology Research Center (MRC), Pasteur Institute of Iran, Tehran, Iran
| | - Farzam Vaziri
- Department of Mycobacteriology and Pulmonary Research, Pasteur Institute of Iran, Tehran, Iran.,Microbiology Research Center (MRC), Pasteur Institute of Iran, Tehran, Iran
| | - Shohreh Khatami
- Department of Biochemistry, Pasteur Institute of Iran, Tehran, Iran
| | - Seyed Davar Siadat
- Department of Mycobacteriology and Pulmonary Research, Pasteur Institute of Iran, Tehran, Iran.,Microbiology Research Center (MRC), Pasteur Institute of Iran, Tehran, Iran
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15
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Jørandli JW, Thorsvik S, Skovdahl HK, Kornfeld B, Sæterstad S, Gustafsson BI, Sandvik AK, van Beelen Granlund A. The serotonin reuptake transporter is reduced in the epithelium of active Crohn's disease and ulcerative colitis. Am J Physiol Gastrointest Liver Physiol 2020; 319:G761-G768. [PMID: 32967429 DOI: 10.1152/ajpgi.00244.2020] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Serotonin is a highly conserved and ubiquitous signaling molecule involved in a vast variety of biological processes. A majority of serotonin is produced in the gastrointestinal epithelium, where it is suggested to act as a prominent regulatory molecule in the inflammatory bowel diseases (IBDs) Crohn's disease (CD) and ulcerative colitis (UC). Extracellular and circulating serotonin levels are thought to be elevated during intestinal inflammation, but the underlying mechanisms have been poorly understood. The data on human material are limited, contradictory, and in need of further investigation and substantiating. In this study, we show a potent and significant downregulation of the dominant serotonin reuptake transporter (SERT) mRNA (SLC6A4) in the epithelium from active CD ileitis, CD colitis, and UC colitis, compared with healthy controls. The mRNA of tryptophan hydroxylase 1, the rate-limiting enzyme in serotonin synthesis, was unregulated. Immunohistochemistry showed expression of the SERT protein in both the epithelium and the lamina propria and localized the downregulation to the epithelial monolayer. Laser capture microdissection followed by RNA sequencing confirmed downregulation of SLC6A4 in the epithelial monolayer during intestinal inflammation. Patient-derived colon epithelial cell lines (colonoids) incubated with the proinflammatory cytokine tumor necrosis factor alpha (TNF-α) reduced SERT expression. In summary, these results show that intestinal inflammation potently reduces the expression of SERT in both CD and UC and that TNF-α alone is sufficient to induce a similar reduction in colonoids. The reduced serotonin reuptake capacity may contribute to the increased interstitial serotonin level associated with intestinal inflammation.NEW & NOTEWORTHY The serotonin reuptake transporter is potently reduced in inflamed areas of Crohn's ileitis, Crohn's colitis, and ulcerative colitis. The changes are localized to the intestinal epithelium and can be induced by TNF-α. The serotonin synthesis through tryptophan hydroxylase 1 is unchanged. This regulation is suggested as a mechanism underlying the increased extracellular serotonin levels associated with intestinal inflammation.
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Affiliation(s)
- Jonas Woll Jørandli
- Department of Clinical and Molecular Medicine (IKOM), Norwegian University of Science and Technology, Trondheim, Norway
| | - Silje Thorsvik
- Department of Clinical and Molecular Medicine (IKOM), Norwegian University of Science and Technology, Trondheim, Norway.,Department of Gastroenterology and Hepatology, St. Olav's University Hospital, Trondheim, Norway.,Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, Trondheim, Norway
| | - Helene Kolstad Skovdahl
- Department of Clinical and Molecular Medicine (IKOM), Norwegian University of Science and Technology, Trondheim, Norway.,Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, Trondheim, Norway
| | - Benedikt Kornfeld
- Department of Clinical and Molecular Medicine (IKOM), Norwegian University of Science and Technology, Trondheim, Norway
| | - Siri Sæterstad
- Department of Clinical and Molecular Medicine (IKOM), Norwegian University of Science and Technology, Trondheim, Norway
| | - Björn Inge Gustafsson
- Department of Gastroenterology and Hepatology, St. Olav's University Hospital, Trondheim, Norway.,Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway
| | - Arne Kristian Sandvik
- Department of Clinical and Molecular Medicine (IKOM), Norwegian University of Science and Technology, Trondheim, Norway.,Department of Gastroenterology and Hepatology, St. Olav's University Hospital, Trondheim, Norway.,Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, Trondheim, Norway
| | - Atle van Beelen Granlund
- Department of Clinical and Molecular Medicine (IKOM), Norwegian University of Science and Technology, Trondheim, Norway.,Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, Trondheim, Norway
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16
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Mishima Y, Ishihara S. Molecular Mechanisms of Microbiota-Mediated Pathology in Irritable Bowel Syndrome. Int J Mol Sci 2020; 21:ijms21228664. [PMID: 33212919 PMCID: PMC7698457 DOI: 10.3390/ijms21228664] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Revised: 11/12/2020] [Accepted: 11/13/2020] [Indexed: 02/07/2023] Open
Abstract
Irritable bowel syndrome (IBS) is one of the most prevalent functional gastrointestinal disorders, and accumulating evidence gained in both preclinical and clinical studies indicate the involvement of enteric microbiota in its pathogenesis. Gut resident microbiota appear to influence brain activity through the enteric nervous system, while their composition and function are affected by the central nervous system. Based on these results, the term “brain–gut–microbiome axis” has been proposed and enteric microbiota have become a potential therapeutic target in IBS cases. However, details regarding the microbe-related pathophysiology of IBS remain elusive. This review summarizes the existing knowledge of molecular mechanisms in the pathogenesis of IBS as well as recent progress related to microbiome-derived neurotransmitters, compounds, metabolites, neuroendocrine factors, and enzymes.
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17
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Manzella CR, Jayawardena D, Pagani W, Li Y, Alrefai WA, Bauer J, Jung B, Weber CR, Gill RK. Serum Serotonin Differentiates Between Disease Activity States in Crohn's Patients. Inflamm Bowel Dis 2020; 26:1607-1618. [PMID: 32844174 PMCID: PMC7500525 DOI: 10.1093/ibd/izaa208] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Indexed: 12/11/2022]
Abstract
BACKGROUND Diagnosis and monitoring of inflammatory bowel diseases (IBDs) utilize invasive methods including endoscopy and tissue biopsy, with blood tests being less specific for IBDs. Substantial evidence has implicated involvement of the neurohormone serotonin (5-hydroxytryptamine, 5-HT) in the pathophysiology of IBDs. The current study investigated whether serum 5-HT is elevated in patients with active ulcerative colitis (UC) or Crohn's disease (CD). METHODS Serum samples were obtained from a German cohort of 96 CD and UC patients with active disease, refractory disease, or remission of disease based upon their disease activity index (DAI) and disease history. High pressure liquid chromatography with tandemmass spectrometry was used to measure 5-HT, tryptophan (TRP), and kynurenine (KYN) levels in the serum samples, and Luminex Multiplex ELISA was used to measure cytokine levels. Intestinal mucosal biopsies were obtained from a separate cohort of healthy and CD patients, and the immunoreactivity of the serotonin transporter (SERT) was determined. RESULTS There was no statistically significant difference in TRP or KYN levels between disease categories in either UC or CD. Interestingly, 5-HT levels were significantly elevated in patients with active CD but not active UC when compared with the levels in remission or refractory disease. Serum 5-HT was superior to C-reactive protein and circulating cytokines in differentiating between disease categories in CD. Additionally, SERT immunoreactivity was decreased in the ileum and colon of patients with CD compared to healthy controls. CONCLUSION We have shown that the serum 5-HT can differentiate between active disease and refractory disease or remission among CD patients, emphasizing the potential suitability of serum 5-HT as an auxiliary measure in diagnosing active CD.
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Affiliation(s)
- Christopher R Manzella
- Department of Physiology & Biophysics, University of Illinois at Chicago, Chicago, IL, USA
| | - Dulari Jayawardena
- Division of Gastroenterology & Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, IL, USA
| | - Wilfredo Pagani
- Department of Medicine, University of Illinois at Chicago, Chicago, IL, USA
| | - Ye Li
- Department of Pathology, University of Chicago, Chicago, IL, USA
| | - Waddah A Alrefai
- Department of Physiology & Biophysics, University of Illinois at Chicago, Chicago, IL, USA
- Jesse Brown VA Medical Center, Chicago, IL, USA
| | - Jessica Bauer
- Department of Medicine, University of Washington, WA, USA
| | - Barbara Jung
- Department of Medicine, University of Washington, WA, USA
| | | | - Ravinder K Gill
- Department of Physiology & Biophysics, University of Illinois at Chicago, Chicago, IL, USA
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18
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Holton NW, Singhal M, Kumar A, Ticho AL, Manzella CR, Malhotra P, Jarava D, Saksena S, Dudeja PK, Alrefai WA, Gill RK. Hepatocyte nuclear factor-4α regulates expression of the serotonin transporter in intestinal epithelial cells. Am J Physiol Cell Physiol 2020; 318:C1294-C1304. [PMID: 32348179 PMCID: PMC7311735 DOI: 10.1152/ajpcell.00477.2019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 04/23/2020] [Accepted: 04/23/2020] [Indexed: 12/20/2022]
Abstract
The serotonin transporter (SERT) functions to regulate the availability of serotonin (5-HT) in the brain and intestine. An intestine-specific mRNA variant arising from a unique transcription start site and alternative promoter in the SERT gene has been identified (iSERT; spanning exon 1C). A decrease in SERT is implicated in several gut disorders, including inflammatory bowel diseases (IBD). However, little is known about mechanisms regulating the iSERT variant, and a clearer understanding is warranted for targeting SERT for the treatment of gut disorders. The current studies examined the expression of iSERT across different human intestinal regions and investigated its regulation by HNF4α (hepatic nuclear factor-4α), a transcription factor important for diverse cellular functions. iSERT mRNA abundance was highest in the human ileum and Caco-2 cell line. iSERT mRNA expression was downregulated by loss of HNF4α (but not HNF1α, HNF1β, or FOXA1) in Caco-2 cells. Overexpression of HNF4α increased iSERT mRNA concomitant with an increase in SERT protein. Progressive promoter deletion and site-directed mutagenesis revealed that the HNF4α response element spans nucleotides -1,163 to -1150 relative to the translation start site. SERT mRNA levels in the intestine were drastically reduced in the intestine-specific HNF4α-knockout mice relative to HNF4αFL/FL mice. Both HNF4α and SERT mRNA levels were also downregulated in mouse model of ileitis (SAMP) compared with AKR control mice. These results establish the transcriptional regulation of iSERT at the gut-specific internal promoter (hSERTp2) and have identified HNF4α as a critical modulator of basal SERT expression in the intestine.
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Affiliation(s)
- Nathaniel W Holton
- Division of Gastroenterology and Hepatology, University of Illinois at Chicago, Chicago, Illinois
| | - Megha Singhal
- Division of Gastroenterology and Hepatology, University of Illinois at Chicago, Chicago, Illinois
| | - Anoop Kumar
- Division of Gastroenterology and Hepatology, University of Illinois at Chicago, Chicago, Illinois
| | - Alexander L Ticho
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, Illinois
| | - Christopher R Manzella
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, Illinois
| | - Pooja Malhotra
- Division of Gastroenterology and Hepatology, University of Illinois at Chicago, Chicago, Illinois
| | - David Jarava
- Division of Gastroenterology and Hepatology, University of Illinois at Chicago, Chicago, Illinois
| | - Seema Saksena
- Division of Gastroenterology and Hepatology, University of Illinois at Chicago, Chicago, Illinois
- Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois
| | - Pradeep K Dudeja
- Division of Gastroenterology and Hepatology, University of Illinois at Chicago, Chicago, Illinois
- Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois
| | - Waddah A Alrefai
- Division of Gastroenterology and Hepatology, University of Illinois at Chicago, Chicago, Illinois
- Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois
| | - Ravinder K Gill
- Division of Gastroenterology and Hepatology, University of Illinois at Chicago, Chicago, Illinois
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19
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Manzella C, Singhal M, Ackerman M, Alrefai WA, Saksena S, Dudeja PK, Gill RK. Serotonin transporter untranslated regions influence mRNA abundance and protein expression. GENE REPORTS 2020; 18. [PMID: 34113740 DOI: 10.1016/j.genrep.2019.100513] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The serotonin transporter (SERT, SLC6A4) is a Na+-dependent transporter that regulates the availability of serotonin (5-HT, 5-hydroxytryptamine), a key neurotransmitter and hormone in the brain and the intestine. The human SERT gene consists of two alternate promoters that drive expression of an identical SERT protein. However, there are different mRNA transcript variants derived from these two promoters that differ in their 5' untranslated region (5'UTR), which is the region of the mRNA upstream from the protein-coding region. Two of these transcripts contain exon-1a and are abundant in neuronal tissue, whereas the third transcript contains exon-1c and is abundant in the intestine. The 3'UTR is nearly identical among the transcripts. Current studies tested the hypothesis that the UTRs of SERT influence its expression in intestinal epithelial cells (IECs) by controlling mRNA or protein levels. The SERT UTRs were cloned into luciferase reporter plasmids and luciferase mRNA and activity were measured following transient transfection of the UTR constructs into the model IEC Caco-2. Luciferase activity and mRNA abundance were higher than the empty vector for two of the three 5'UTR variants. Calculation of translation index (luciferase activity divided by the relative luciferase mRNA level) revealed that the exon-1a containing 5'UTRs had enhanced translation when compared to the exon-1c containing 5'UTR which exhibited a low translation efficiency. Compared to the empty vector, the SERT 3'UTR markedly decreased luciferase activity. In silico analysis of the SERT 3'UTR revealed many conserved potential miRNA binding sites that may be responsible for this decrease. In conclusion, we have shown that the UTRs of SERT regulate mRNA abundance and protein expression. Delineating the molecular basis by which the UTRs of SERT influence its expression will lead to an increased understanding of post-transcriptional regulation of SERT in GI disorders associated with altered 5-HT availability.
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Affiliation(s)
- Christopher Manzella
- Department of Physiology & Biophysics, University of Illinois at Chicago, Chicago, IL, United States of America
| | - Megha Singhal
- Division of Gastroenterology & Hepatology, University of Illinois at Chicago, Chicago, IL, United States of America
| | - Max Ackerman
- University of Illinois at Chicago, College of Liberal Arts and Sciences, United States of America
| | - Waddah A Alrefai
- Division of Gastroenterology & Hepatology, University of Illinois at Chicago, Chicago, IL, United States of America.,Jesse Brown VA Medical Center, Chicago, IL, United States of America
| | - Seema Saksena
- Division of Gastroenterology & Hepatology, University of Illinois at Chicago, Chicago, IL, United States of America.,Jesse Brown VA Medical Center, Chicago, IL, United States of America
| | - Pradeep K Dudeja
- Division of Gastroenterology & Hepatology, University of Illinois at Chicago, Chicago, IL, United States of America.,Jesse Brown VA Medical Center, Chicago, IL, United States of America
| | - Ravinder K Gill
- Division of Gastroenterology & Hepatology, University of Illinois at Chicago, Chicago, IL, United States of America.,Jesse Brown VA Medical Center, Chicago, IL, United States of America
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20
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Manzella CR, Ackerman M, Singhal M, Ticho AL, Ceh J, Alrefai WA, Saksena S, Dudeja PK, Gill RK. Serotonin Modulates AhR Activation by Interfering with CYP1A1-Mediated Clearance of AhR Ligands. Cell Physiol Biochem 2020; 54:126-141. [PMID: 32017483 PMCID: PMC7050772 DOI: 10.33594/000000209] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/18/2019] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND/AIMS Serotonin (5-hydroxytryptamine, 5-HT) is a neurotransmitter and hormone with important physiological functions in many organs, including the intestine. We have previously shown that 5-HT activates the aryl hydrocarbon receptor (AhR) in intestinal epithelial cells (IECs) via a serotonin transporter (SERT)-dependent mechanism. AhR is a nuclear receptor that binds a variety of molecules including tryptophan (TRP) metabolites to regulate physiological processes in the intestine including xenobiotic detoxification and immune modulation. We hypothesized that 5-HT activates AhR indirectly by interfering with metabolic clearance of AhR ligands by cytochrome P450 1A1 (CYP1A1). METHODS Inhibition of CYP1A1 activity by 5-HT was assessed in the human intestinal epithelial cell line Caco-2 and recombinant CYP1A1 microsomes using both luciferase and LC-MS/MS. Degradation of 5-HT by recombinant CYP1A1 was measured by LC-MS/MS. For in vitro studies, CYP1A1 and CYP1B1 mRNA expression levels were measured by RT-PCR and CYP1A1 activity was measured by ethoxyresorufin-O-deethylase (EROD) assays. For in vivo studies, AhR ligands were administered to SERT KO mice and WT littermates and intestinal mucosa CYP1A1 mRNA was measured. RESULTS We show that 5-HT inhibits metabolism of both the pro-luciferin CYP1A1 substrate Luc-CEE as well as the high affinity AhR ligand 6-formylindolo[3,2-b] carbazole (FICZ). Recombinant CYP1A1 assays revealed that 5-HT is metabolized by CYP1A1 in an NADPH dependent manner. Treatment with 5-HT in TRP-free medium, which is devoid of trace AhR ligands, showed that 5-HT requires the presence of AhR ligands to activate AhR. Cotreatment with 5-HT and FICZ confirmed that 5-HT potentiates induction of AhR target genes by AhR ligands. However, this was only true for ligands which are CYP1A1 substrates such as FICZ. Administration of β-napthoflavone by gavage or indole-3-carbinol via diet to SERT KO mice revealed that lack of SERT impairs intestinal AhR activation. CONCLUSION Our studies provide novel evidence of crosstalk between serotonergic and AhR signaling where 5-HT can influence the ability of AhR ligands to activate the receptor in the intestine.
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Affiliation(s)
- Christopher R Manzella
- Department of Physiology & Biophysics, University of Illinois at Chicago, Chicago, IL, USA
| | - Max Ackerman
- Division of Gastroenterology & Hepatology, University of Illinois at Chicago, Chicago, IL, USA
| | - Megha Singhal
- Division of Gastroenterology & Hepatology, University of Illinois at Chicago, Chicago, IL, USA
| | - Alexander L Ticho
- Department of Physiology & Biophysics, University of Illinois at Chicago, Chicago, IL, USA
| | - Justin Ceh
- Division of Gastroenterology & Hepatology, University of Illinois at Chicago, Chicago, IL, USA
| | - Waddah A Alrefai
- Division of Gastroenterology & Hepatology, University of Illinois at Chicago, Chicago, IL, USA.,Jesse Brown VA Medical Center, Chicago, IL, USA
| | - Seema Saksena
- Division of Gastroenterology & Hepatology, University of Illinois at Chicago, Chicago, IL, USA.,Jesse Brown VA Medical Center, Chicago, IL, USA
| | - Pradeep K Dudeja
- Division of Gastroenterology & Hepatology, University of Illinois at Chicago, Chicago, IL, USA.,Jesse Brown VA Medical Center, Chicago, IL, USA
| | - Ravinder K Gill
- Division of Gastroenterology & Hepatology, University of Illinois at Chicago, Chicago, IL, USA,
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21
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Accarie A, Vanuytsel T. Animal Models for Functional Gastrointestinal Disorders. Front Psychiatry 2020; 11:509681. [PMID: 33262709 PMCID: PMC7685985 DOI: 10.3389/fpsyt.2020.509681] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2019] [Accepted: 10/22/2020] [Indexed: 12/12/2022] Open
Abstract
Functional gastrointestinal disorders (FGID), such as functional dyspepsia (FD) and irritable bowel syndrome (IBS) are characterized by chronic abdominal symptoms in the absence of an organic, metabolic or systemic cause that readily explains these complaints. Their pathophysiology is still not fully elucidated and animal models have been of great value to improve the understanding of the complex biological mechanisms. Over the last decades, many animal models have been developed to further unravel FGID pathophysiology and test drug efficacy. In the first part of this review, we focus on stress-related models, starting with the different perinatal stress models, including the stress of the dam, followed by a discussion on neonatal stress such as the maternal separation model. We also describe the most commonly used stress models in adult animals which brought valuable insights on the brain-gut axis in stress-related disorders. In the second part, we focus more on models studying peripheral, i.e., gastrointestinal, mechanisms, either induced by an infection or another inflammatory trigger. In this section, we also introduce more recent models developed around food-related metabolic disorders or food hypersensitivity and allergy. Finally, we introduce models mimicking FGID as a secondary effect of medical interventions and spontaneous models sharing characteristics of GI and anxiety-related disorders. The latter are powerful models for brain-gut axis dysfunction and bring new insights about FGID and their comorbidities such as anxiety and depression.
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Affiliation(s)
- Alison Accarie
- Department of Chronic Diseases, Metabolism and Ageing (ChroMetA), Translational Research Center for Gastrointestinal Disorders (TARGID), KU Leuven, Leuven, Belgium
| | - Tim Vanuytsel
- Department of Chronic Diseases, Metabolism and Ageing (ChroMetA), Translational Research Center for Gastrointestinal Disorders (TARGID), KU Leuven, Leuven, Belgium.,Department of Gastroenterology and Hepatology, University Hospitals Leuven, Leuven, Belgium
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22
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Shajib MS, Chauhan U, Adeeb S, Chetty Y, Armstrong D, Halder SLS, Marshall JK, Khan WI. Characterization of Serotonin Signaling Components in Patients with Inflammatory Bowel Disease. J Can Assoc Gastroenterol 2019; 2:132-140. [PMID: 31294376 PMCID: PMC6619411 DOI: 10.1093/jcag/gwy039] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Tryptophan hydroxylase (TPH)1 catalyzes the biosynthesis of serotonin (5-hydroxytrptamine; 5-HT) in enterochromaffin (EC) cells, the predominant source of gut 5-HT. Secreted 5-HT regulates various gut functions through diverse 5-HT receptor (5-HTR) families, and 5-HT transporter (5-HTT) sequesters its activity via uptake into surrounding cells. In inflammatory bowel disease (IBD) mucosal 5-HT signaling is altered, including upregulated EC cell numbers and 5-HT levels. We examined key mucosal 5-HT signaling components and blood 5-HT levels and, as part of a pilot study, investigated the association between 5-HTT gene-linked polymorphic region (5HTTLPR) and Crohn's disease (CD). METHODS In the context of inflammation, colonic expressions of TPH1, 5-HTT and 5-HTRs were studied in CD patients (n=15) and healthy controls (HC; n=10) using quantitative polymerase chain reaction (qPCR). We also investigated 5HTTLPR in 40 CD patients and HC utilizing PCR and measured platelet-poor plasma (PPP) and plasma 5-HT concentrations. RESULTS Compared with HC, inflammation in CD patients was associated with elevated TPH1, 5-HTR3, 5-HTR4, 5-HTR7 and downregulated 5-HTT expressions. In our second cohort of participants, significantly higher PPP and plasma 5-HT levels and higher S-genotype (L/S+S/S) than L/L genotype were observed in CD patients compared with HC. CONCLUSION Our results suggest that augmented mucosal 5-HT signaling and specific 5-HTTLPR genotype-associated decreased efficiency in 5-HT reuptake, the latter through increased 5-HT availability, may contribute to inflammation in CD patients. These findings revealed important information on various components of 5-HT signaling in intestinal inflammation which may ultimately lead to effective strategies targeting this pathway in IBD.
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Affiliation(s)
- Md Sharif Shajib
- Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, Ontario, Canada
- Department of Pathology & Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Usha Chauhan
- Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, Ontario, Canada
- Hamiltion Health Sciences, Hamilton, Ontario, Canada
| | - Salman Adeeb
- Department of Pathology & Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Yeshale Chetty
- Department of Pathology & Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
| | - David Armstrong
- Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, Ontario, Canada
- Division of Gastroenterology, Department of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Smita L S Halder
- Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, Ontario, Canada
- Division of Gastroenterology, Department of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - John K Marshall
- Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, Ontario, Canada
- Division of Gastroenterology, Department of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Waliul I Khan
- Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, Ontario, Canada
- Department of Pathology & Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
- Correspondence: Dr Waliul I. Khan (nominated for communications with the editorial office), Department of Pathology & Molecular Medicine, McMaster University, HSC 3N7-1280 Main Street West, Hamilton, ON, L8S 4K1, Canada, e-mail
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23
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Stavely R, Fraser S, Sharma S, Rahman AA, Stojanovska V, Sakkal S, Apostolopoulos V, Bertrand P, Nurgali K. The Onset and Progression of Chronic Colitis Parallels Increased Mucosal Serotonin Release via Enterochromaffin Cell Hyperplasia and Downregulation of the Serotonin Reuptake Transporter. Inflamm Bowel Dis 2018; 24:1021-1034. [PMID: 29668991 DOI: 10.1093/ibd/izy016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2017] [Indexed: 12/21/2022]
Abstract
BACKGROUND Serotonin (5-hydroxytryptamine, 5-HT) has been linked with several inflammation-associated intestinal diseases, including ulcerative colitis (UC). The largest pool of 5-HT in the body is in enterochromaffin (EC) cells located throughout the intestinal tract. EC cells are mechanosensitive and detect noxious stimuli, inducing secretion of 5-HT, which plays an important role in enteric reflexes and immunomodulation. In this study, we evaluated intestinal 5-HT levels in the Winnie mouse model of spontaneous chronic colitis, which closely replicates UC. METHODS Real-time electrochemical recordings of 5-HT oxidation currents were obtained from ex vivo preparations of jejunum, ileum, proximal, and distal colon from Winnie (5-25 weeks old) and age matched C57BL/6 mice. EC cells were examined by immunohistochemistry, and the gene expression of tryptophan hydroxylase 1 (5-HT synthesis) and the serotonin reuptake transporter (SERT) were determined by quantitative Real-Time Polymerase Chain Reaction (RT-qPCR). RESULTS Compression-evoked and basal 5-HT concentrations were elevated in the distal and proximal colon of Winnie mice. EC cell hyperplasia and downregulation of SERT on the transcriptional level were identified as mechanisms underlying increased levels of 5-HT. Increase in mucosal 5-HT release was observed at the onset of disease at 7-14 weeks, confirmed by disease activity scores. Furthermore, increases in 5-HT levels and progression of disease activity correlated linearly with age, but not sex. CONCLUSIONS Our findings in the Winnie mouse model of spontaneous chronic colitis demonstrate for the first time that the onset and progression of chronic UC-like intestinal inflammation is associated with increased 5-HT levels in the colonic mucosa.
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Affiliation(s)
- Rhian Stavely
- College of Health and Biomedicine, Victoria University; Western Centre for Health, Research and Education, Sunshine Hospital, Melbourne, Victoria, Australia.,Department of Medicine, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Regenerative Medicine and Stem Cells Program, Australian Institute of Musculoskeletal Science (AIMSS), Western Health
| | - Sarah Fraser
- Centre for Chronic Disease; College of Health and Biomedicine, Victoria University, Melbourne, Victoria, Australia
| | - Shilpa Sharma
- Department of Medicine, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Regenerative Medicine and Stem Cells Program, Australian Institute of Musculoskeletal Science (AIMSS), Western Health
| | - Ahmed A Rahman
- College of Health and Biomedicine, Victoria University; Western Centre for Health, Research and Education, Sunshine Hospital, Melbourne, Victoria, Australia.,Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, Australia
| | - Vanesa Stojanovska
- College of Health and Biomedicine, Victoria University; Western Centre for Health, Research and Education, Sunshine Hospital, Melbourne, Victoria, Australia.,Hudson Institute of Medical Research; Monash Health Translation Precinct, Melbourne, Victoria, Australia
| | - Samy Sakkal
- College of Health and Biomedicine, Victoria University; Western Centre for Health, Research and Education, Sunshine Hospital, Melbourne, Victoria, Australia
| | - Vasso Apostolopoulos
- Centre for Chronic Disease; College of Health and Biomedicine, Victoria University, Melbourne, Victoria, Australia
| | - Paul Bertrand
- School of Health and Biomedical Sciences, Royal Melbourne Institute of Technology University, Melbourne, Victoria, Australia
| | - Kulmira Nurgali
- College of Health and Biomedicine, Victoria University; Western Centre for Health, Research and Education, Sunshine Hospital, Melbourne, Victoria, Australia.,Department of Medicine, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Regenerative Medicine and Stem Cells Program, Australian Institute of Musculoskeletal Science (AIMSS), Western Health
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24
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Serotonin is an endogenous regulator of intestinal CYP1A1 via AhR. Sci Rep 2018; 8:6103. [PMID: 29666456 PMCID: PMC5904159 DOI: 10.1038/s41598-018-24213-5] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Accepted: 03/28/2018] [Indexed: 02/07/2023] Open
Abstract
Aryl hydrocarbon receptor (AhR) is a nuclear receptor that controls xenobiotic detoxification via induction of cytochrome P450 1A1 (CYP1A1) and regulates immune responses in the intestine. Metabolites of L-tryptophan activate AhR, which confers protection against intestinal inflammation. We tested the hypothesis that serotonin (5-HT) is an endogenous activator of AhR in intestinal epithelial cells. Treatment of Caco-2 monolayers with 5-HT induced CYP1A1 mRNA in a time- and concentration-dependent manner and also stimulated CYP1A1 activity. CYP1A1 induction by 5-HT was dependent upon uptake via serotonin transporter (SERT). Antagonism of AhR and knockdown of AhR and its binding partner aryl hydrocarbon receptor nuclear translocator (ARNT) attenuated CYP1A1 induction by 5-HT. Activation of AhR was evident by its nuclear translocation after 5-HT treatment and by induction of an AhR-responsive luciferase reporter. In vivo studies showed a dramatic decrease in CYP1A1 expression and other AhR target genes in SERT KO ileal mucosa by microarray analysis. These results suggest that intracellular accumulation of 5-HT via SERT induces CYP1A1 expression via AhR in intestinal epithelial cells, and SERT deficiency in vivo impairs activation of AhR. Our studies provide a novel link between the serotonergic and AhR pathways which has implications in xenobiotic metabolism and intestinal inflammation.
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25
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Coates MD, Tekin I, Vrana KE, Mawe GM. Review article: the many potential roles of intestinal serotonin (5-hydroxytryptamine, 5-HT) signalling in inflammatory bowel disease. Aliment Pharmacol Ther 2017; 46:569-580. [PMID: 28737264 DOI: 10.1111/apt.14226] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2017] [Revised: 04/10/2017] [Accepted: 06/24/2017] [Indexed: 12/19/2022]
Abstract
BACKGROUND Serotonin (5-hydroxytryptamine, 5-HT) is an important mediator of every major gut-related function. Recent investigations also suggest that 5-HT can influence the development and severity of inflammation within the gut, particularly in the setting of inflammatory bowel disease (IBD). AIM To review the roles that the intestinal serotonin signalling system plays in gut function, with a specific focus on IBD. METHODS We reviewed manuscripts from 1952 to 2017 that investigated and discussed roles for 5-HT signalling in gastrointestinal function and IBD, as well as the influence of inflammation on 5-HT signalling elements within the gut. RESULTS Inflammation appears to affect every major element of intestinal 5-HT signalling, including 5-HT synthesis, release, receptor expression and reuptake capacity. Importantly, many studies (most utilising animal models) also demonstrate that modulation of selective serotonergic receptors (via agonism of 5-HT4 R and antagonism of 5-HT3 R) or 5-HT signal termination (via serotonin reuptake inhibitors) can alter the likelihood and severity of intestinal inflammation and/or its complicating symptoms. However, there are few human studies that have studied these relationships in a targeted manner. CONCLUSIONS Insights discussed in this review have strong potential to lead to new diagnostic and therapeutic tools to improve the management of IBD and other related disorders. Specifically, strategies that focus on modifying the activity of selective serotonin receptors and reuptake transporters in the gut could be effective for controlling disease activity and/or its associated symptoms. Further studies in humans are required, however, to more completely understand the pathophysiological mechanisms underlying the roles of 5-HT in this setting.
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Affiliation(s)
- M D Coates
- Department of Medicine, Division of Gastroenterology & Hepatology, Penn State Hershey Medical Center, Hershey, PA, USA
| | - I Tekin
- Neuroscience Institute, University of California at Santa Barbara, Santa Barbara, CA, USA
| | - K E Vrana
- Department of Pharmacology, Penn State College of Medicine, Hershey, PA, USA
| | - G M Mawe
- Department of Neurological Sciences, University of Vermont College of Medicine, Burlington, VT, USA
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26
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Shajib MS, Baranov A, Khan WI. Diverse Effects of Gut-Derived Serotonin in Intestinal Inflammation. ACS Chem Neurosci 2017; 8:920-931. [PMID: 28288510 DOI: 10.1021/acschemneuro.6b00414] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The gut is the largest producer of serotonin or 5-hydroxytryptamine (5-HT) in the human body, and 5-HT has been recognized as an important signaling molecule in the gut for decades. There are two distinct sources of enteric 5-HT. Mucosal 5-HT is predominantly produced by enterochromaffin (EC) cells of the gastrointestinal (GI) tract, and neuronal 5-HT in the gut is produced by serotonergic neurons of the enteric nervous system (ENS). The quantity of mucosal 5-HT produced vastly eclipses the amount of neuronal 5-HT in the gut. Though it is difficult to separate the functions of neuronal and mucosal 5-HT, in the normal gut both types of enteric 5-HT work synergistically playing a prominent role in the maintenance of GI functions. In inflammatory conditions of the gut, like inflammatory bowel disease (IBD) recent studies have revealed new diverse functions of enteric 5-HT. Mucosal 5-HT plays an important role in the production of pro-inflammatory mediators from immune cells, and neuronal 5-HT provides neuroprotection in the ENS. Based on searches for terms such as "5-HT", "EC cell", "ENS", and "inflammation" in pubmed.gov as well as by utilizing pertinent reviews, the current review aims to provide an update on the role of enteric 5-HT and its immune mediators in the context of intestinal inflammation.
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Affiliation(s)
- Md. Sharif Shajib
- Farncombe Family Digestive Health Research Institute, Hamilton, Ontario L8S
4K1, Canada
- Department of Pathology & Molecular Medicine, McMaster University, Hamilton, Ontario L8S 4K1, Canada
| | - Adriana Baranov
- Farncombe Family Digestive Health Research Institute, Hamilton, Ontario L8S
4K1, Canada
- Department of Pathology & Molecular Medicine, McMaster University, Hamilton, Ontario L8S 4K1, Canada
| | - Waliul I. Khan
- Farncombe Family Digestive Health Research Institute, Hamilton, Ontario L8S
4K1, Canada
- Department of Pathology & Molecular Medicine, McMaster University, Hamilton, Ontario L8S 4K1, Canada
- Hamilton
Regional Laboratory Medicine Program, Hamilton Health Sciences, Hamilton, Ontario L8N 3Z5, Canada
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27
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GENETIC TRIGGERS AND NEUROHUMORAL MESSENGERS OF POSTOPERATIVE INTESTINAL PARESIS, ITS VALUE IN PREDICTION, PREVENTION AND TREATMENT. EUREKA: HEALTH SCIENCES 2016. [DOI: 10.21303/2504-5679.2016.00036] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The aim of research: to study the causes and mechanisms of postoperative intestinal paresis on the base of assessment of genetic determinism of neurohormonal processes which regulate the contractile ability of the intestines, to determine their role for the choice of treatment tactics.
The study presents data about connection between variants of SERT gene, which regulates the reuptake of serotonin, and its concentration in blood plasma and the probability of occurrence of postoperative intestinal paresis. This made it possible not only to predict the occurrence of postoperative disorders of motor-evacuation function of the intestines, but also to improve the algorithms of prevention and pathogenetic based treatment.
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