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Delfini M, Stakenborg N, Viola MF, Boeckxstaens G. Macrophages in the gut: Masters in multitasking. Immunity 2022; 55:1530-1548. [PMID: 36103851 DOI: 10.1016/j.immuni.2022.08.005] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 07/17/2022] [Accepted: 08/09/2022] [Indexed: 11/05/2022]
Abstract
The gastrointestinal tract has the important task of absorbing nutrients, a complex process that requires an intact barrier allowing the passage of nutrients but that simultaneously protects the host against invading microorganisms. To maintain and regulate intestinal homeostasis, the gut is equipped with one of the largest populations of macrophages in the body. Here, we will discuss our current understanding of intestinal macrophage heterogeneity and describe their main functions in the different anatomical niches of the gut during steady state. In addition, their role in inflammatory conditions such as infection, inflammatory bowel disease, and postoperative ileus are discussed, highlighting the roles of macrophages in immune defense. To conclude, we describe the interaction between macrophages and the enteric nervous system during development and adulthood and highlight their contribution to neurodegeneration in the context of aging and diabetes.
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Affiliation(s)
- Marcello Delfini
- Translational Research Center for GI Disorders (TARGID), Department of Chronic Diseases, Metabolism and Ageing, KU Leuven-University of Leuven, Leuven, Belgium
| | - Nathalie Stakenborg
- Translational Research Center for GI Disorders (TARGID), Department of Chronic Diseases, Metabolism and Ageing, KU Leuven-University of Leuven, Leuven, Belgium
| | - Maria Francesca Viola
- Translational Research Center for GI Disorders (TARGID), Department of Chronic Diseases, Metabolism and Ageing, KU Leuven-University of Leuven, Leuven, Belgium
| | - Guy Boeckxstaens
- Translational Research Center for GI Disorders (TARGID), Department of Chronic Diseases, Metabolism and Ageing, KU Leuven-University of Leuven, Leuven, Belgium.
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Caravaca AS, Levine YA, Drake A, Eberhardson M, Olofsson PS. Vagus Nerve Stimulation Reduces Indomethacin-Induced Small Bowel Inflammation. Front Neurosci 2022; 15:730407. [PMID: 35095387 PMCID: PMC8789651 DOI: 10.3389/fnins.2021.730407] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Accepted: 12/16/2021] [Indexed: 12/11/2022] Open
Abstract
Crohn's disease is a chronic, idiopathic condition characterized by intestinal inflammation and debilitating gastrointestinal symptomatology. Previous studies of inflammatory bowel disease (IBD), primarily in colitis, have shown reduced inflammation after electrical or pharmacological activation of the vagus nerve, but the scope and kinetics of this effect are incompletely understood. To investigate this, we studied the effect of electrical vagus nerve stimulation (VNS) in a rat model of indomethacin-induced small intestinal inflammation. 1 min of VNS significantly reduced small bowel total inflammatory lesion area [(mean ± SEM) sham: 124 ± 14 mm2, VNS: 62 ± 14 mm2, p = 0.002], intestinal peroxidation and chlorination rates, and intestinal and systemic pro-inflammatory cytokine levels as compared with sham-treated animals after 24 h following indomethacin administration. It was not known whether this observed reduction of inflammation after VNS in intestinal inflammation was mediated by direct innervation of the gut or if the signals are relayed through the spleen. To investigate this, we studied the VNS effect on the small bowel lesions of splenectomized rats and splenic nerve stimulation (SNS) in intact rats. We observed that VNS reduced small bowel inflammation also in splenectomized rats but SNS alone failed to significantly reduce small bowel lesion area. Interestingly, VNS significantly reduced small bowel lesion area for 48 h when indomethacin administration was delayed. Thus, 1 min of electrical activation of the vagus nerve reduced indomethacin-induced intestinal lesion area by a spleen-independent mechanism. The surprisingly long-lasting and spleen-independent effect of VNS on the intestinal response to indomethacin challenge has important implications on our understanding of neural control of intestinal inflammation and its potential translation to improved therapies for IBD.
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Affiliation(s)
- April S. Caravaca
- Laboratory of Immunobiology, Department of Medicine, Karolinska University Hospital, Solna, Sweden
- MedTechLabs, BioClinicum, Stockholm Center for Bioelectronic Medicine, Karolinska University Hospital, Solna, Sweden
- SetPoint Medical, Inc., Valencia, CA, United States
| | - Yaakov A. Levine
- Laboratory of Immunobiology, Department of Medicine, Karolinska University Hospital, Solna, Sweden
- MedTechLabs, BioClinicum, Stockholm Center for Bioelectronic Medicine, Karolinska University Hospital, Solna, Sweden
- SetPoint Medical, Inc., Valencia, CA, United States
- Institute of Bioelectronic Medicine, The Feinstein Institutes for Medical Research, New York, NY, United States
| | - Anna Drake
- SetPoint Medical, Inc., Valencia, CA, United States
| | - Michael Eberhardson
- Laboratory of Immunobiology, Department of Medicine, Karolinska University Hospital, Solna, Sweden
- MedTechLabs, BioClinicum, Stockholm Center for Bioelectronic Medicine, Karolinska University Hospital, Solna, Sweden
- Department of Gastroenterology and Hepatology, University Hospital of Linköping, Linköping, Sweden
- Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden
| | - Peder S. Olofsson
- Laboratory of Immunobiology, Department of Medicine, Karolinska University Hospital, Solna, Sweden
- MedTechLabs, BioClinicum, Stockholm Center for Bioelectronic Medicine, Karolinska University Hospital, Solna, Sweden
- Institute of Bioelectronic Medicine, The Feinstein Institutes for Medical Research, New York, NY, United States
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Populin L, Stebbing MJ, Furness JB. Neuronal regulation of the gut immune system and neuromodulation for treating inflammatory bowel disease. FASEB Bioadv 2021; 3:953-966. [PMID: 34761177 PMCID: PMC8565205 DOI: 10.1096/fba.2021-00070] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 08/04/2021] [Accepted: 08/10/2021] [Indexed: 02/06/2023] Open
Abstract
The gut immune system in the healthy intestine is anti-inflammatory, but can move to a pro-inflammatory state when the gut is challenged by pathogens or in disease. The nervous system influences the level of inflammation through enteric neurons and extrinsic neural connections, particularly vagal and sympathetic innervation of the gastrointestinal tract, each of which exerts anti-inflammatory effects. Within the enteric nervous system (ENS), three neuron types that influence gut immune cells have been identified, intrinsic primary afferent neurons (IPANs), vasoactive intestinal peptide (VIP) neurons that project to the mucosa, and cholinergic neurons that influence macrophages in the external muscle layers. The enteric neuropeptides, calcitonin gene-related peptide (CGRP), tachykinins, and neuromedin U (NMU), which are contained in IPANs, and VIP produced by the mucosa innervating neurons, all influence immune cells, notably innate lymphoid cells (ILCs). ILC2 are stimulated by VIP to release IL-22, which promotes microbial defense and tissue repair. Enteric neurons are innervated by the vagus, and, in the large intestine, by the pelvic nerves. Vagal nerve stimulation reduces gut inflammation, which may be both by stimulation of efferent (motor) pathways to the ENS, and stimulation of afferent pathways that connect to integrating centers in the CNS. Efferent pathways from the CNS have their anti-inflammatory effects through either or both vagal efferent neurons and sympathetic pathways. The final neurons in sympathetic pathways reduce gut inflammation by the action of noradrenaline on β2 adrenergic receptors expressed by immune cells. Activation of neural anti-inflammatory pathways is an attractive option to treat inflammatory bowel disease that is refractory to other treatments. Further investigation of the ways in which enteric reflexes, vagal pathways and sympathetic pathways integrate their effects to modulate the gut immune system and gut inflammation is needed to optimize neuromodulation therapy.
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Affiliation(s)
- Luis Populin
- Department of NeuroscienceSchool of Medicine and Public HealthUniversity of Wisconsin‐MadisonMadisonWisconsinUSA
| | - Martin J. Stebbing
- Florey Institute of Neuroscience and Mental HealthParkvilleVICAustralia
- Department of Anatomy & PhysiologyUniversity of MelbourneParkvilleVICAustralia
| | - John B. Furness
- Florey Institute of Neuroscience and Mental HealthParkvilleVICAustralia
- Department of Anatomy & PhysiologyUniversity of MelbourneParkvilleVICAustralia
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Ye R, Huang J, Wang Z, Chen Y, Dong Y. Trace Element Selenium Effectively Alleviates Intestinal Diseases. Int J Mol Sci 2021; 22:ijms222111708. [PMID: 34769138 PMCID: PMC8584275 DOI: 10.3390/ijms222111708] [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: 08/23/2021] [Revised: 10/18/2021] [Accepted: 10/26/2021] [Indexed: 12/28/2022] Open
Abstract
Selenium (Se) is an essential trace element in the body. It is mainly used in the body in the form of selenoproteins and has a variety of biological functions. Intestinal diseases caused by chronic inflammation are among the most important threats to human health, and there is no complete cure at present. Due to its excellent antioxidant function, Se has been proven to be effective in alleviating intestinal diseases such as inflammatory bowel diseases (IBDs). Therefore, this paper introduces the role of Se and selenoproteins in the intestinal tract and the mechanism of their involvement in the mediation of intestinal diseases. In addition, it introduces the advantages and disadvantages of nano-Se as a new Se preparation and traditional Se supplement in the prevention and treatment of intestinal diseases, so as to provide a reference for the further exploration of the interaction between selenium and intestinal health.
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Affiliation(s)
- Ruihua Ye
- College of Veterinary Medicine, China Agricultural University, Beijing 100193, China; (R.Y.); (Z.W.); (Y.C.)
| | - Jiaqiang Huang
- Key Laboratory of Precision Nutrition and Food Quality, Ministry of Education, China Agricultural University, Beijing 100193, China;
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, Department of Nutrition and Health, China Agricultural University, Beijing 100193, China
| | - Zixu Wang
- College of Veterinary Medicine, China Agricultural University, Beijing 100193, China; (R.Y.); (Z.W.); (Y.C.)
| | - Yaoxing Chen
- College of Veterinary Medicine, China Agricultural University, Beijing 100193, China; (R.Y.); (Z.W.); (Y.C.)
| | - Yulan Dong
- College of Veterinary Medicine, China Agricultural University, Beijing 100193, China; (R.Y.); (Z.W.); (Y.C.)
- Correspondence:
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Tracey KJ, Chavan S, Murakami M. Introduction: Electronic Medicine in Immunology Special Issue Part 1. Int Immunol 2021. [DOI: 10.1093/intimm/dxab024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Electronic Medicine in Immunology.
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Affiliation(s)
- Kevin J Tracey
- Institute of Bioelectronic Medicine, The Feinstein Institutes for Medical Research, Northwell Health, 350 Community Drive, NY 11030, USA
- Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, 500 Hofstra Blvd., Hempstead, NY 11549, USA
- The Elmezzi Graduate School of Molecular Medicine, 350 Community Drive, Manhasset, NY 11030, USA
| | - Sangeeta Chavan
- Institute of Bioelectronic Medicine, The Feinstein Institutes for Medical Research, Northwell Health, 350 Community Drive, NY 11030, USA
- Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, 500 Hofstra Blvd., Hempstead, NY 11549, USA
- The Elmezzi Graduate School of Molecular Medicine, 350 Community Drive, Manhasset, NY 11030, USA
| | - Masaaki Murakami
- Molecular Psychoimmunology, Institute for Genetic Medicine, Graduate School of Medicine, Hokkaido University, N15 W7, Kita-ku, Sapporo, Hokkaido 060-8638, Japan
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