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Almeida PP, Brito ML, Thomasi B, Mafra D, Fouque D, Knauf C, Tavares-Gomes AL, Stockler-Pinto MB. Is the enteric nervous system a lost piece of the gut-kidney axis puzzle linked to chronic kidney disease? Life Sci 2024; 351:122793. [PMID: 38848938 DOI: 10.1016/j.lfs.2024.122793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Revised: 05/20/2024] [Accepted: 06/04/2024] [Indexed: 06/09/2024]
Abstract
The enteric nervous system (ENS) regulates numerous functional and immunological attributes of the gastrointestinal tract. Alterations in ENS cell function have been linked to intestinal outcomes in various metabolic, intestinal, and neurological disorders. Chronic kidney disease (CKD) is associated with a challenging intestinal environment due to gut dysbiosis, which further affects patient quality of life. Although the gut-related repercussions of CKD have been thoroughly investigated, the involvement of the ENS in this puzzle remains unclear. ENS cell dysfunction, such as glial reactivity and alterations in cholinergic signaling in the small intestine and colon, in CKD are associated with a wide range of intestinal pathways and responses in affected patients. This review discusses how the ENS is affected in CKD and how it is involved in gut-related outcomes, including intestinal permeability, inflammation, oxidative stress, and dysmotility.
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Affiliation(s)
| | - Michele Lima Brito
- Pathology Post Graduate Program, Fluminense Federal University (UFF), Niterói, RJ, Brazil
| | - Beatriz Thomasi
- Department of Physiology, Neuroscience Program, Michigan State University (MSU), East Lansing, MI, USA
| | - Denise Mafra
- Graduate Program in Biological Sciences - Physiology, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
| | - Denis Fouque
- Department of Nephrology, Centre Hopitalier Lyon Sud, INSERM 1060, CENS, Université de Lyon, France
| | - Claude Knauf
- INSERM U1220 Institut de Recherche en Santé Digestive, CHU Purpan, Université Toulouse III Paul Sabatier Toulouse, Toulouse, France
| | - Ana Lúcia Tavares-Gomes
- Neurosciences Post Graduate Program, Fluminense Federal University (UFF), Niterói, RJ, Brazil
| | - Milena Barcza Stockler-Pinto
- Pathology Post Graduate Program, Fluminense Federal University (UFF), Niterói, RJ, Brazil; INSERM U1220 Institut de Recherche en Santé Digestive, CHU Purpan, Université Toulouse III Paul Sabatier Toulouse, Toulouse, France
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2
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Liu W, Yan H, Jia W, Huang J, Fu Z, Xu W, Yu H, Yang W, Pan W, Zheng B, Liu Y, Chen X, Gao Y, Tian D. Association between gut microbiota and Hirschsprung disease: a bidirectional two-sample Mendelian randomization study. Front Microbiol 2024; 15:1366181. [PMID: 38516012 PMCID: PMC10956417 DOI: 10.3389/fmicb.2024.1366181] [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: 01/05/2024] [Accepted: 02/20/2024] [Indexed: 03/23/2024] Open
Abstract
Background Several studies have pointed to the critical role of gut microbiota (GM) and their metabolites in Hirschsprung disease (HSCR) pathogenesis. However, the detailed causal relationship between GM and HSCR remains unknown. Methods In this study, we used two-sample Mendelian randomization (MR) analysis to investigate the causal relationship between GM and HSCR, based on the MiBioGen Consortium's genome-wide association study (GWAS) and the GWAS Catalog's HSCR data. Reverse MR analysis was performed subsequently, and the sensitivity analysis, Cochran's Q-test, MR pleiotropy residual sum, outlier (MR-PRESSO), and the MR-Egger intercept were used to analyze heterogeneity or horizontal pleiotropy. 16S rDNA sequencing and targeted mass spectrometry were developed for initial validation. Results In the forward MR analysis, inverse-variance weighted (IVW) estimates suggested that Eggerthella (OR: 2.66, 95%CI: 1.23-5.74, p = 0.01) was a risk factor for HSCR, while Peptococcus (OR: 0.37, 95%CI: 0.18-0.73, p = 0.004), Ruminococcus2 (OR: 0.32, 95%CI: 0.11-0.91, p = 0.03), Clostridiaceae1 (OR: 0.22, 95%CI: 0.06-0.78, p = 0.02), Mollicutes RF9 (OR: 0.27, 95%CI: 0.09-0.8, p = 0.02), Ruminococcaceae (OR: 0.16, 95%CI: 0.04-0.66, p = 0.01), and Paraprevotella (OR: 0.45, 95%CI: 0.21-0.98, p = 0.04) were protective factors for HSCR, which had no heterogeneity or horizontal pleiotropy. However, reverse MR analysis showed that HSCR (OR: 1.02, 95%CI: 1-1.03, p = 0.049) is the risk factor for Eggerthella. Furthermore, some of the above microbiota and short-chain fatty acids (SCFAs) were altered in HSCR, showing a correlation. Conclusion Our analysis established the relationship between specific GM and HSCR, identifying specific bacteria as protective or risk factors. Significant microbiota and SCFAs were altered in HSCR, underlining the importance of further study and providing new insights into the pathogenesis and treatment.
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Affiliation(s)
- Wei Liu
- Department of Pediatric Surgery, The Second Affiliated Hospital, Xi'an Jiaotong University, Xi'an, China
- Institute of Neurobiology, Environment and Genes Related to Diseases Key Laboratory of Chinese Ministry of Education, Xi'an Jiaotong University, Xi'an, China
| | - Hanlei Yan
- Department of Pediatric Surgery, The Second Affiliated Hospital, Xi'an Jiaotong University, Xi'an, China
- Institute of Neurobiology, Environment and Genes Related to Diseases Key Laboratory of Chinese Ministry of Education, Xi'an Jiaotong University, Xi'an, China
| | - Wanying Jia
- Department of Pediatric Surgery, The Second Affiliated Hospital, Xi'an Jiaotong University, Xi'an, China
- Institute of Neurobiology, Environment and Genes Related to Diseases Key Laboratory of Chinese Ministry of Education, Xi'an Jiaotong University, Xi'an, China
| | - Jingjing Huang
- Department of Pediatric Surgery, The Second Affiliated Hospital, Xi'an Jiaotong University, Xi'an, China
- Institute of Neurobiology, Environment and Genes Related to Diseases Key Laboratory of Chinese Ministry of Education, Xi'an Jiaotong University, Xi'an, China
| | - Zihao Fu
- Department of Pediatric Surgery, The Second Affiliated Hospital, Xi'an Jiaotong University, Xi'an, China
- Institute of Neurobiology, Environment and Genes Related to Diseases Key Laboratory of Chinese Ministry of Education, Xi'an Jiaotong University, Xi'an, China
| | - Wenyao Xu
- Department of Pediatric Surgery, The Second Affiliated Hospital, Xi'an Jiaotong University, Xi'an, China
- Institute of Neurobiology, Environment and Genes Related to Diseases Key Laboratory of Chinese Ministry of Education, Xi'an Jiaotong University, Xi'an, China
| | - Hui Yu
- Department of Pediatric Surgery, The Second Affiliated Hospital, Xi'an Jiaotong University, Xi'an, China
- Institute of Neurobiology, Environment and Genes Related to Diseases Key Laboratory of Chinese Ministry of Education, Xi'an Jiaotong University, Xi'an, China
| | - Weili Yang
- Department of Pediatric Surgery, The Second Affiliated Hospital, Xi'an Jiaotong University, Xi'an, China
| | - Weikang Pan
- Department of Pediatric Surgery, The Second Affiliated Hospital, Xi'an Jiaotong University, Xi'an, China
| | - Baijun Zheng
- Department of Pediatric Surgery, The Second Affiliated Hospital, Xi'an Jiaotong University, Xi'an, China
| | - Yong Liu
- Institute of Neurobiology, Environment and Genes Related to Diseases Key Laboratory of Chinese Ministry of Education, Xi'an Jiaotong University, Xi'an, China
| | - Xinlin Chen
- Institute of Neurobiology, Environment and Genes Related to Diseases Key Laboratory of Chinese Ministry of Education, Xi'an Jiaotong University, Xi'an, China
| | - Ya Gao
- Department of Pediatric Surgery, The Second Affiliated Hospital, Xi'an Jiaotong University, Xi'an, China
| | - Donghao Tian
- Department of Pediatric Surgery, The Second Affiliated Hospital, Xi'an Jiaotong University, Xi'an, China
- Institute of Neurobiology, Environment and Genes Related to Diseases Key Laboratory of Chinese Ministry of Education, Xi'an Jiaotong University, Xi'an, China
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Elfers K, Watanangura A, Hoffmann P, Suchodolski JS, Khattab MR, Pilla R, Meller S, Volk HA, Mazzuoli-Weber G. Fecal supernatants from dogs with idiopathic epilepsy activate enteric neurons. Front Neurosci 2024; 18:1281840. [PMID: 38356649 PMCID: PMC10864448 DOI: 10.3389/fnins.2024.1281840] [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: 08/23/2023] [Accepted: 01/15/2024] [Indexed: 02/16/2024] Open
Abstract
Introduction Alterations in the composition and function of the gut microbiome have been reported in idiopathic epilepsy (IE), however, interactions of gut microbes with the enteric nervous system (ENS) in this context require further study. This pilot study examined how gastrointestinal microbiota (GIM), their metabolites, and nutrients contained in intestinal contents communicate with the ENS. Methods Fecal supernatants (FS) from healthy dogs and dogs with IE, including drug-naïve, phenobarbital (PB) responsive, and PB non-responsive dogs, were applied to cultured myenteric neurons to test their activation using voltage-sensitive dye neuroimaging. Additionally, the concentrations of short-chain fatty acids (SCFAs) in the FS were quantified. Results Our findings indicate that FS from all examined groups elicited neuronal activation. Notably, FS from PB non-responsive dogs with IE induced action potential discharge in a higher proportion of enteric neurons compared to healthy controls, which exhibited the lowest burst frequency overall. Furthermore, the highest burst frequency in enteric neurons was observed upon exposure to FS from drug-naïve dogs with IE. This frequency was significantly higher compared to that observed in PB non-responsive dogs with IE and showed a tendency to surpass that of healthy controls. Discussion Although observed disparities in SCFA concentrations across the various FS samples might be associated with the induced neuronal activity, a direct correlation remains elusive at this point. The obtained results hint at an involvement of the ENS in canine IE and set the basis for future studies.
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Affiliation(s)
- Kristin Elfers
- Institute for Physiology and Cell Biology, University of Veterinary Medicine Hannover Foundation, Hannover, Germany
| | - Antja Watanangura
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover Foundation, Hannover, Germany
- Center for Systems Neuroscience (ZSN), Hannover, Germany
- Veterinary Research and Academic Service, Faculty of Veterinary Medicine, Kasetsart University, Kamphaeng Saen, Nakhon Pathom, Thailand
| | - Pascal Hoffmann
- Institute for Physiology and Cell Biology, University of Veterinary Medicine Hannover Foundation, Hannover, Germany
| | - Jan S. Suchodolski
- Gastrointestinal Laboratory, Department of Small Animal Clinical Sciences, Texas A&M University, College Station, TX, United States
| | - Mohammad R. Khattab
- Gastrointestinal Laboratory, Department of Small Animal Clinical Sciences, Texas A&M University, College Station, TX, United States
| | - Rachel Pilla
- Gastrointestinal Laboratory, Department of Small Animal Clinical Sciences, Texas A&M University, College Station, TX, United States
| | - Sebastian Meller
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover Foundation, Hannover, Germany
| | - Holger A. Volk
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover Foundation, Hannover, Germany
- Center for Systems Neuroscience (ZSN), Hannover, Germany
| | - Gemma Mazzuoli-Weber
- Institute for Physiology and Cell Biology, University of Veterinary Medicine Hannover Foundation, Hannover, Germany
- Center for Systems Neuroscience (ZSN), Hannover, Germany
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Barth BB, Redington ER, Gautam N, Pelot NA, Grill WM. Calcium image analysis in the moving gut. Neurogastroenterol Motil 2023; 35:e14678. [PMID: 37736662 PMCID: PMC10999186 DOI: 10.1111/nmo.14678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 08/14/2023] [Accepted: 08/28/2023] [Indexed: 09/23/2023]
Abstract
BACKGROUND The neural control of gastrointestinal muscle relies on circuit activity whose underlying motifs remain limited by small-sample calcium imaging recordings confounded by motion artifact, paralytics, and muscle dissections. We present a sequence of resources to register images from moving preparations and identify out-of-focus events in widefield fluorescent microscopy. METHODS Our algorithm uses piecewise rigid registration with pathfinding to correct movements associated with smooth muscle contractions. We developed methods to identify loss-of-focus events and to simulate calcium activity to evaluate registration. KEY RESULTS By combining our methods with principal component analysis, we found populations of neurons exhibit distinct activity patterns in response to distinct stimuli consistent with hypothesized roles. The image analysis pipeline makes deeper insights possible by capturing concurrently calcium dynamics from more neurons in larger fields of view. We provide access to the source code for our algorithms and make experimental and technical recommendations to increase data quality in calcium imaging experiments. CONCLUSIONS These methods make feasible large population, robust calcium imaging recordings and permit more sophisticated network analyses and insights into neural activity patterns in the gut.
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Affiliation(s)
- Bradley B. Barth
- Department of Biomedical Engineering, Duke University, Durham, NC 27708
| | - Emily R. Redington
- Department of Biomedical Engineering, Duke University, Durham, NC 27708
- Current employment Regeneron Pharmaceuticals, Inc. Contributions to this article were made as an employee of Duke University and the views expressed do not necessarily represent the views of Regeneron Pharmaceuticals Inc
| | - Nitisha Gautam
- Department of Biomedical Engineering, Duke University, Durham, NC 27708
| | - Nicole A. Pelot
- Department of Biomedical Engineering, Duke University, Durham, NC 27708
| | - Warren M. Grill
- Department of Biomedical Engineering, Duke University, Durham, NC 27708
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Zhang T, Liu W, Lu H, Cheng T, Wang L, Wang G, Zhang H, Chen W. Lactic acid bacteria in relieving constipation: mechanism, clinical application, challenge, and opportunity. Crit Rev Food Sci Nutr 2023:1-24. [PMID: 37971876 DOI: 10.1080/10408398.2023.2278155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2023]
Abstract
Constipation is a prevalent gastrointestinal symptom that can considerably affect a patients' quality of life. Although several drugs have been used to treat constipation, they are associated with high costs, side effects, and low universality. Therefore, alternative intervention strategies are urgently needed. Traditional lactic acid bacteria (LAB), such as Bifidobacterium and Lactobacillus, play a vital role in regulating intestinal microecology and have demonstrated favorable effects in constipation; however, a comprehensive review of their constipation relief mechanisms is limited. This review summarizes the pathogenesis of constipation and the relationship between intestinal motility and gut microbiota, elucidates the possible mechanism by which LAB alleviates of constipation through a systematic summary of animal and clinical research, and highlights the challenges and applications of LAB in the treatment of constipation. Our review can improve our understanding of constipation, and advance targeted microecological therapeutic agents, such as LAB.
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Affiliation(s)
- Tong Zhang
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, China
- School of Food Science and Technology, Jiangnan University, Wuxi, China
| | - Wenxu Liu
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, China
- School of Food Science and Technology, Jiangnan University, Wuxi, China
| | - Huimin Lu
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, China
- School of Food Science and Technology, Jiangnan University, Wuxi, China
| | - Ting Cheng
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, China
- School of Food Science and Technology, Jiangnan University, Wuxi, China
| | - Linlin Wang
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, China
- School of Food Science and Technology, Jiangnan University, Wuxi, China
- (Yangzhou) Institute of Food Biotechnology, Jiangnan University, Yangzhou, China
| | - Gang Wang
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, China
- School of Food Science and Technology, Jiangnan University, Wuxi, China
- (Yangzhou) Institute of Food Biotechnology, Jiangnan University, Yangzhou, China
| | - Hao Zhang
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, China
- School of Food Science and Technology, Jiangnan University, Wuxi, China
- (Yangzhou) Institute of Food Biotechnology, Jiangnan University, Yangzhou, China
| | - Wei Chen
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, China
- School of Food Science and Technology, Jiangnan University, Wuxi, China
- National Engineering Research Center for Functional Food, Jiangnan University, Wuxi, China
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Yeramilli V, Cheddadi R, Shah J, Brawner K, Martin C. A Review of the Impact of Maternal Prenatal Stress on Offspring Microbiota and Metabolites. Metabolites 2023; 13:metabo13040535. [PMID: 37110193 PMCID: PMC10142778 DOI: 10.3390/metabo13040535] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 04/06/2023] [Accepted: 04/07/2023] [Indexed: 04/29/2023] Open
Abstract
Maternal prenatal stress exposure affects the development of offspring. We searched for articles in the PubMed database and reviewed the evidence for how prenatal stress alters the composition of the microbiome, the production of microbial-derived metabolites, and regulates microbiome-induced behavioral changes in the offspring. The gut-brain signaling axis has gained considerable attention in recent years and provides insights into the microbial dysfunction in several metabolic disorders. Here, we reviewed evidence from human studies and animal models to discuss how maternal stress can modulate the offspring microbiome. We will discuss how probiotic supplementation has a profound effect on the stress response, the production of short chain fatty acids (SCFAs), and how psychobiotics are emerging as novel therapeutic targets. Finally, we highlight the potential molecular mechanisms by which the effects of stress are transmitted to the offspring and discuss how the mitigation of early-life stress as a risk factor can improve the birth outcomes.
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Affiliation(s)
- Venkata Yeramilli
- Division of Pediatric Surgery, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Riadh Cheddadi
- Division of Pediatric Surgery, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Juhi Shah
- Burnett School of Medicine, Texas Christian University, Fort Worth, TX 76129, USA
| | - Kyle Brawner
- Department of Biology, Lipscomb University, Nashville, TN 37204, USA
| | - Colin Martin
- Division of Pediatric Surgery, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL 35294, USA
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Hazart D, Delhomme B, Oheim M, Ricard C. Label-free, fast, 2-photon volume imaging of the organization of neurons and glia in the enteric nervous system. Front Neuroanat 2023; 16:1070062. [PMID: 36844894 PMCID: PMC9948619 DOI: 10.3389/fnana.2022.1070062] [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: 10/14/2022] [Accepted: 12/19/2022] [Indexed: 02/11/2023] Open
Abstract
The enteric nervous system (ENS), sometimes referred to as a "second brain" is a quasi-autonomous nervous system, made up of interconnected plexuses organized in a mesh-like network lining the gastrointestinal tract. Originally described as an actor in the regulation of digestion, bowel contraction, and intestinal secretion, the implications of the ENS in various central neuropathologies has recently been demonstrated. However, with a few exceptions, the morphology and pathologic alterations of the ENS have mostly been studied on thin sections of the intestinal wall or, alternatively, in dissected explants. Precious information on the three-dimensional (3-D) architecture and connectivity is hence lost. Here, we propose the fast, label-free 3-D imaging of the ENS, based on intrinsic signals. We used a custom, fast tissue-clearing protocol based on a high refractive-index aqueous solution to increase the imaging depth and allow us the detection of faint signals and we characterized the autofluorescence (AF) from the various cellular and sub-cellular components of the ENS. Validation by immunofluorescence and spectral recordings complete this groundwork. Then, we demonstrate the rapid acquisition of detailed 3-D image stacks from unlabeled mouse ileum and colon, across the whole intestinal wall and including both the myenteric and submucosal enteric nervous plexuses using a new spinning-disk two-photon (2P) microscope. The combination of fast clearing (less than 15 min for 73% transparency), AF detection and rapid volume imaging [less than 1 min for the acquisition of a z-stack of 100 planes (150*150 μm) at sub-300-nm spatial resolution] opens up the possibility for new applications in fundamental and clinical research.
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Affiliation(s)
- Doriane Hazart
- Université Paris Cité, CNRS, Saints-Pères Paris Institute for the Neurosciences, Paris, France
| | - Brigitte Delhomme
- Université Paris Cité, CNRS, Saints-Pères Paris Institute for the Neurosciences, Paris, France
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Jiang W, Wu J, Zhu S, Xin L, Yu C, Shen Z. The Role of Short Chain Fatty Acids in Irritable Bowel Syndrome. J Neurogastroenterol Motil 2022; 28:540-548. [PMID: 36250361 PMCID: PMC9577580 DOI: 10.5056/jnm22093] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Accepted: 10/07/2022] [Indexed: 11/20/2022] Open
Abstract
Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder that is characterized by abdominal pain and disordered bowel habits. The etiology of IBS is multifactorial, including abnormal gut-brain interactions, visceral hypersensitivity, altered colon motility, and psychological factors. Recent studies have shown that the intestinal microbiota and its metabolites short chain fatty acids (SCFAs) may be involved in the pathogenesis of IBS. SCFAs play an important role in the pathophysiology of IBS. We discuss the underlying mechanisms of action of SCFAs in intestinal inflammation and immunity, intestinal barrier integrity, motility, and the microbiota-gut-brain axis. Limited to previous studies, further studies are required to investigate the mechanisms of action of SCFAs in IBS and provide more precise therapeutic strategies for IBS.
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Affiliation(s)
- Wenxi Jiang
- Department of Gastroenterology, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | - Jiali Wu
- Department of Gastroenterology, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | - Shefeng Zhu
- Department of Gastroenterology, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | - Linying Xin
- Department of Gastroenterology, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | - Chaohui Yu
- Department of Gastroenterology, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | - Zhe Shen
- Department of Gastroenterology, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
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Atractyloside-A ameliorates spleen deficiency diarrhea by interfering with TLR4/MyD88/NF-κB signaling activation and regulating intestinal flora homeostasis. Int Immunopharmacol 2022; 107:108679. [DOI: 10.1016/j.intimp.2022.108679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 02/28/2022] [Accepted: 03/01/2022] [Indexed: 11/20/2022]
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Joyce SA, O'Malley D. Bile acids, bioactive signalling molecules in interoceptive gut-to-brain communication. J Physiol 2022; 600:2565-2578. [PMID: 35413130 PMCID: PMC9325455 DOI: 10.1113/jp281727] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 04/07/2022] [Indexed: 11/08/2022] Open
Abstract
Aside from facilitating solubilisation and absorption of dietary lipids and lipid-soluble vitamins, amphipathic bile acids (BAs) also act as bioactive signalling molecules. A plethora of conjugated or un-conjugated primary and bacterially-modified secondary BA moieties have been identified, with significant divergence between species. These molecules are excreted into the external environment of the intestinal lumen, yet nuclear and membrane receptors that are sensitive to BAs are expressed internally in the liver, intestinal and neural tissues, amongst others. The diversity of BAs and receptors underpins the multitude of distinct bioactive functions attributed to BAs, but also hampers elucidation of the physiological mechanisms underpinning these actions. In this topical review, we have considered the potential of BAs as cross-barrier signalling molecules that contribute to interoceptive pathways informing the central nervous system of environmental changes in the gut lumen. Activation of BAs on FGF19 -secreting enterocytes, enteroendocrine cells coupled to sensory nerves or intestinal immune cells would facilitate indirect signalling, whereas direct activation of BA receptors in the brain are likely to occur primarily under pathophysiological conditions when concentrations of BAs are elevated. Abstract figure legend The figure illustrates the microbial modification of hepatic primary bile acids into secondary bile acids. In addition to facilitating lipid digestion and absorption, bile acids act as bioactive signalling molecules by binding to bile acid receptors expressed on enterocytes, neural afferent-coupled enteroendocrine cells and immune cells. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Susan A Joyce
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland.,APC Microbiome Ireland, University College Cork, Cork, Ireland
| | - Dervla O'Malley
- APC Microbiome Ireland, University College Cork, Cork, Ireland.,Department of Physiology, College of Medicine and Health, University College Cork, Cork, Ireland
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12
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Vanden Berghe P, Fung C. Optical Approaches to Understanding Enteric Circuits Along the Radial Axis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1383:71-79. [PMID: 36587147 DOI: 10.1007/978-3-031-05843-1_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The gastrointestinal tract operates in a highly dynamic environment. The gut is typically exposed to continually changing and highly convoluted luminal compositions comprising not only ingested content but also a multitude of resident microbes and microbial factors. It is therefore critical that the gut is capable of distinguishing between nutritious components from noxious substances. This is facilitated by specialized cellular sensory machinery that are in place in the intestinal epithelium and the ENS. However, the specific chemosensory processes and enteric neuronal pathways that enable the gut to discern and respond appropriately to different chemicals remain unclear. A major hurdle in studying the neural processing of luminal information has been the complex spatial organization of the mucosal structures and their innervation along the radial axis. Much of our current knowledge of enteric neuronal responses to luminal stimuli stems from studies that used semi-dissected guinea pig small intestine preparations with the mucosa and submucosa removed in one-half in order to record electrical activity from exposed myenteric neurons or in the circular muscle. Building on this, we ultimately strive to work towards integrated systems with all the gut layers intact. With advanced microscopy techniques including multiphoton intravital imaging, together with transgenic technologies utilizing cell-type specific activity-dependent reporters, we stand in good stead for studying the ENS in more intact preparations and even in live animals. In this chapter, we highlight recent contributions to the knowledge of sensory gut innervation by the developing and mature ENS. We also revisit established work examining the functional connectivity between the myenteric and submucosal plexus, and discuss the methodologies that can help advance our understanding of the enteric circuitry and signaling along the mucosa-serosa axis.
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Affiliation(s)
- Pieter Vanden Berghe
- Laboratory for Enteric NeuroScience (LENS), Translational Research Center for Gastrointestinal Disorders (TARGID), University of Leuven, Leuven, Belgium.
| | - Candice Fung
- Laboratory for Enteric NeuroScience (LENS), Translational Research Center for Gastrointestinal Disorders (TARGID), University of Leuven, Leuven, Belgium
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Najjar SA, Edwards BS, Albers KM, Davis BM, Smith-Edwards KM. Optogenetic activation of the distal colon epithelium engages enteric nervous system circuits to initiate motility patterns. Am J Physiol Gastrointest Liver Physiol 2021; 321:G426-G435. [PMID: 34468219 PMCID: PMC8560371 DOI: 10.1152/ajpgi.00026.2021] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 08/18/2021] [Accepted: 08/23/2021] [Indexed: 02/07/2023]
Abstract
Digestive functions of the colon depend on sensory-motor reflexes in the enteric nervous system (ENS), initiated by intrinsic primary afferent neurons (IPANs). IPAN terminals project to the mucosal layer of the colon, allowing communication with epithelial cells comprising the colon lining. The chemical nature and functional significance of this epithelial-neural communication in regard to secretion and colon motility are of high interest. Colon epithelial cells can produce and release neuroactive substances such as ATP and 5-hydroxytryptamine (5-HT), which can activate receptors on adjacent nerve fibers, including IPAN subtypes. In this study, we examined if stimulation of epithelial cells alone is sufficient to activate neural circuits that control colon motility. Optogenetics and calcium imaging were used in ex vivo preparations of the mouse colon to selectively stimulate the colon epithelium, measure changes in motility, and record activity of neurons within the myenteric plexus. Light-mediated activation of epithelial cells lining the distal, but not proximal, colon caused local contractions and increased the rate of colonic migrating motor complexes. Epithelial-evoked local contractions in the distal colon were reduced by both ATP and 5-HT receptor antagonists. Our findings indicate that colon epithelial cells likely use purinergic and serotonergic signaling to initiate activity in myenteric neurons, produce local contractions, and facilitate large-scale coordination of ENS activity responsible for whole colon motility patterns.NEW & NOTEWORTHY Using an all-optical approach to measure real-time cell-to-cell communication responsible for colon functions, we show that selective optogenetic stimulation of distal colon epithelium produced activity in myenteric neurons, as measured with red genetically encoded calcium indicators. The epithelial-induced neural response led to local contractions, mediated by both purinergic and serotonergic signaling, and facilitated colonic motor complexes that propagate from proximal to distal colon.
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Affiliation(s)
- Sarah A Najjar
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
- Pittsburgh Center for Pain Research, University of Pittsburgh, Pittsburgh, Pennsylvania
- Center for Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Brian S Edwards
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
- Pittsburgh Center for Pain Research, University of Pittsburgh, Pittsburgh, Pennsylvania
- Center for Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Kathryn M Albers
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
- Pittsburgh Center for Pain Research, University of Pittsburgh, Pittsburgh, Pennsylvania
- Center for Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Brian M Davis
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
- Pittsburgh Center for Pain Research, University of Pittsburgh, Pittsburgh, Pennsylvania
- Center for Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Kristen M Smith-Edwards
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
- Pittsburgh Center for Pain Research, University of Pittsburgh, Pittsburgh, Pennsylvania
- Center for Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania
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