1
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Jamka JR, Gulbransen BD. Mechanisms of enteric neuropathy in diverse contexts of gastrointestinal dysfunction. Neurogastroenterol Motil 2024:e14870. [PMID: 39038157 DOI: 10.1111/nmo.14870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Revised: 06/11/2024] [Accepted: 07/10/2024] [Indexed: 07/24/2024]
Abstract
The enteric nervous system (ENS) commands moment-to-moment gut functions through integrative neurocircuitry housed in the gut wall. The functional continuity of ENS networks is disrupted in enteric neuropathies and contributes to major disturbances in normal gut activities including abnormal gut motility, secretions, pain, immune dysregulation, and disrupted signaling along the gut-brain axis. The conditions under which enteric neuropathy occurs are diverse and the mechanistic underpinnings are incompletely understood. The purpose of this brief review is to summarize the current understanding of the cell types involved, the conditions in which neuropathy occurs, and the mechanisms implicated in enteric neuropathy such as oxidative stress, toll like receptor signaling, purines, and pre-programmed cell death.
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Affiliation(s)
- Julia R Jamka
- Department of Physiology, Michigan State University, East Lansing, Michigan, USA
| | - Brian D Gulbransen
- Department of Physiology, Michigan State University, East Lansing, Michigan, USA
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2
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Llorente C. The Imperative for Innovative Enteric Nervous System-Intestinal Organoid Co-Culture Models: Transforming GI Disease Modeling and Treatment. Cells 2024; 13:820. [PMID: 38786042 PMCID: PMC11119846 DOI: 10.3390/cells13100820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Revised: 04/29/2024] [Accepted: 05/08/2024] [Indexed: 05/25/2024] Open
Abstract
This review addresses the need for innovative co-culture systems integrating the enteric nervous system (ENS) with intestinal organoids. The breakthroughs achieved through these techniques will pave the way for a transformative era in gastrointestinal (GI) disease modeling and treatment strategies. This review serves as an introduction to the companion protocol paper featured in this journal. The protocol outlines the isolation and co-culture of myenteric and submucosal neurons with small intestinal organoids. This review provides an overview of the intestinal organoid culture field to establish a solid foundation for effective protocol application. Remarkably, the ENS surpasses the number of neurons in the spinal cord. Referred to as the "second brain", the ENS orchestrates pivotal roles in GI functions, including motility, blood flow, and secretion. The ENS is organized into myenteric and submucosal plexuses. These plexuses house diverse subtypes of neurons. Due to its proximity to the gut musculature and its cell type complexity, there are methodological intricacies in studying the ENS. Diverse approaches such as primary cell cultures, three-dimensional (3D) neurospheres, and induced ENS cells offer diverse insights into the multifaceted functionality of the ENS. The ENS exhibits dynamic interactions with the intestinal epithelium, the muscle layer, and the immune system, influencing epithelial physiology, motility, immune responses, and the microbiome. Neurotransmitters, including acetylcholine (ACh), serotonin (5-HT), and vasoactive intestinal peptide (VIP), play pivotal roles in these intricate interactions. Understanding these dynamics is imperative, as the ENS is implicated in various diseases, ranging from neuropathies to GI disorders and neurodegenerative diseases. The emergence of organoid technology presents an unprecedented opportunity to study ENS interactions within the complex milieu of the small and large intestines. This manuscript underscores the urgent need for standardized protocols and advanced techniques to unravel the complexities of the ENS and its dynamic relationship with the gut ecosystem. The insights gleaned from such endeavors hold the potential to revolutionize GI disease modeling and treatment paradigms.
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Affiliation(s)
- Cristina Llorente
- Department of Medicine, University of California San Diego, MC0063, 9500 Gilman Drive, La Jolla, CA 92093, USA
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3
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Liu J, Zhang S, Emadi S, Guo T, Chen L, Feng B. Morphological, molecular, and functional characterization of mouse glutamatergic myenteric neurons. Am J Physiol Gastrointest Liver Physiol 2024; 326:G279-G290. [PMID: 38193160 PMCID: PMC11211033 DOI: 10.1152/ajpgi.00200.2023] [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: 09/18/2023] [Revised: 12/26/2023] [Accepted: 01/02/2024] [Indexed: 01/10/2024]
Abstract
The enteric nervous system (ENS) functions largely independently of the central nervous system (CNS). Glutamate, the dominant neurotransmitter in the CNS and sensory afferents, is not a primary neurotransmitter in the ENS. Only a fraction (∼2%) of myenteric neurons in the mouse distal colon and rectum (colorectum) are positive for vesicular glutamate transporter type 2 (VGLUT2), the structure and function of which remain undetermined. Here, we systematically characterized VGLUT2-positive enteric neurons (VGLUT2-ENs) through sparse labeling with adeno-associated virus, single-cell mRNA sequencing (scRNA-seq), and GCaMP6f calcium imaging. Our results reveal that the majority of VGLUT2-ENs (29 of 31, 93.5%) exhibited Dogiel type I morphology with a single aborally projecting axon; most axons (26 of 29, 89.7%) are between 4 and 10 mm long, each traversing 19 to 34 myenteric ganglia. These anatomical features exclude the VGLUT2-ENs from being intrinsic primary afferent or motor neurons. The scRNA-seq conducted on 52 VGLUT2-ENs suggests different expression profiles from conventional descending interneurons. Ex vivo GCaMP6f recordings from flattened colorectum indicate that almost all VGLUT2-EN (181 of 215, 84.2%) are indirectly activated by colorectal stretch via nicotinic cholinergic neural transmission. In conclusion, VGLUT2-ENs are a functionally unique group of enteric neurons with single aborally projecting long axons that traverse multiple myenteric ganglia and are activated indirectly by colorectal mechanical stretch. This knowledge will provide a solid foundation for subsequent studies on the potential interactions of VGLUT2-EN with extrinsic colorectal afferents via glutamatergic neurotransmission.NEW & NOTEWORTHY We reveal that VGLUT2-positive enteric neurons (EN), although constituting a small fraction of total EN, are homogeneously expressed in the myenteric ganglia, with a slight concentration at the intermediate region between the colon and rectum. Through anatomic, molecular, and functional analyses, we demonstrated that VGLUT2-ENs are activated indirectly by noxious circumferential colorectal stretch via nicotinic cholinergic transmission, suggesting their participation in mechanical visceral nociception.
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Affiliation(s)
- Jia Liu
- Department of Biomedical Engineering, University of Connecticut, Storrs, Connecticut, United States
| | - Shaopeng Zhang
- Department of Biomedical Engineering, University of Connecticut, Storrs, Connecticut, United States
| | - Sharareh Emadi
- Department of Biomedical Engineering, University of Connecticut, Storrs, Connecticut, United States
| | - Tiantian Guo
- Department of Biomedical Engineering, University of Connecticut, Storrs, Connecticut, United States
| | - Longtu Chen
- Department of Biomedical Engineering, University of Connecticut, Storrs, Connecticut, United States
| | - Bin Feng
- Department of Biomedical Engineering, University of Connecticut, Storrs, Connecticut, United States
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Guha L, Agnihotri TG, Jain A, Kumar H. Gut microbiota and traumatic central nervous system injuries: Insights into pathophysiology and therapeutic approaches. Life Sci 2023; 334:122193. [PMID: 37865177 DOI: 10.1016/j.lfs.2023.122193] [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: 06/28/2023] [Revised: 10/12/2023] [Accepted: 10/18/2023] [Indexed: 10/23/2023]
Abstract
Traumatic brain injury and spinal cord injury are two distinct but fundamentally similar types of acute insults to the central nervous system (CNS) that often culminate in death or cognitive and motor impairment. Over the past decade, researchers have tapped into research to discover the potential role being played by gut bacteria in CNS. After an acute CNS injury, the altered composition of the gut microbiota disturbs the balance of the bidirectional gut-brain axis, aggravating secondary CNS injury, motor dysfunctions, and cognitive deficits, which worsens the patient's prognosis. Some of the well-known therapeutic interventions which can also be used as adjuvant therapy for alleviating CNS injuries include, the use of pro and prebiotics, fecal microbiota transplantation, and microbial engineering. In this review, we aim to discuss the importance of gut microbes in our nervous system, anatomy, and signaling pathways involved in regulating the gut-brain axis, the alteration of the gut microbiome in CNS injuries, and the therapeutic strategies to target gut microbiomes in traumatic CNS injuries.
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Affiliation(s)
- Lahanya Guha
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER)-Ahmedabad, Gandhinagar, Gujarat 382355, India
| | - Tejas Girish Agnihotri
- Department of Pharmaceutics, National Institute of Pharmaceutical Education and Research (NIPER)-Ahmedabad, Gandhinagar, Gujarat 382355, India
| | - Aakanchha Jain
- Department of Pharmaceutics, National Institute of Pharmaceutical Education and Research (NIPER)-Ahmedabad, Gandhinagar, Gujarat 382355, India
| | - Hemant Kumar
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER)-Ahmedabad, Gandhinagar, Gujarat 382355, India.
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5
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Münzberg H, Berthoud HR, Neuhuber WL. Sensory spinal interoceptive pathways and energy balance regulation. Mol Metab 2023; 78:101817. [PMID: 37806487 PMCID: PMC10590858 DOI: 10.1016/j.molmet.2023.101817] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 10/02/2023] [Accepted: 10/03/2023] [Indexed: 10/10/2023] Open
Abstract
Interoception plays an important role in homeostatic regulation of energy intake and metabolism. Major interoceptive pathways include gut-to-brain and adipose tissue-to brain signaling via vagal sensory nerves and hormones, such as leptin. However, signaling via spinal sensory neurons is rapidly emerging as an additional important signaling pathway. Here we provide an in-depth review of the known anatomy and functions of spinal sensory pathways and discuss potential mechanisms relevant for energy balance homeostasis in health and disease. Because sensory innervation by dorsal root ganglia (DRG) neurons goes far beyond vagally innervated viscera and includes adipose tissue, skeletal muscle, and skin, it is in a position to provide much more complete metabolic information to the brain. Molecular and anatomical identification of function specific DRG neurons will be important steps in designing pharmacological and neuromodulation approaches to affect energy balance regulation in disease states such as obesity, diabetes, and cancer.
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Affiliation(s)
- Heike Münzberg
- Neurobiology of Nutrition & Metabolism Department, Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA, USA.
| | - Hans-Rudolf Berthoud
- Neurobiology of Nutrition & Metabolism Department, Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA, USA.
| | - Winfried L Neuhuber
- Institute for Anatomy and Cell Biology, Friedrich-Alexander University, Erlangen, Germany.
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6
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Robinson BG, Oster BA, Robertson K, Kaltschmidt JA. Loss of ASD-related molecule Cntnap2 affects colonic motility in mice. Front Neurosci 2023; 17:1287057. [PMID: 38027494 PMCID: PMC10665486 DOI: 10.3389/fnins.2023.1287057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Accepted: 10/24/2023] [Indexed: 12/01/2023] Open
Abstract
Gastrointestinal (GI) symptoms are highly prevalent among individuals with autism spectrum disorder (ASD), but the molecular link between ASD and GI dysfunction remains poorly understood. The enteric nervous system (ENS) is critical for normal GI motility and has been shown to be altered in mouse models of ASD and other neurological disorders. Contactin-associated protein-like 2 (Cntnap2) is an ASD-related synaptic cell-adhesion molecule important for sensory processing. In this study, we examine the role of Cntnap2 in GI motility by characterizing Cntnap2's expression in the ENS and assessing GI function in Cntnap2 mutant mice. We find Cntnap2 expression predominately in enteric sensory neurons. We further assess in vivo and ex vivo GI motility in Cntnap2 mutants and show altered transit time and colonic motility patterns. The overall organization of the ENS appears undisturbed. Our results suggest that Cntnap2 plays a role in GI function and may provide a molecular link between ASD and GI dysfunction.
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Affiliation(s)
- Beatriz G. Robinson
- Wu Tsai Neurosciences Institute, Stanford University, Stanford, CA, United States
- Neurosciences IDP Graduate Program, Stanford University School of Medicine, Stanford, CA, United States
| | - Beau A. Oster
- Nevada ENDURE Program, University of Nevada, Reno, Reno, NV, United States
| | - Keiramarie Robertson
- Wu Tsai Neurosciences Institute, Stanford University, Stanford, CA, United States
- Neurosciences IDP Graduate Program, Stanford University School of Medicine, Stanford, CA, United States
| | - Julia A. Kaltschmidt
- Wu Tsai Neurosciences Institute, Stanford University, Stanford, CA, United States
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, United States
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7
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Liu J, Zhang S, Emadi S, Guo T, Chen L, Feng B. Morphological, molecular, and functional characterization of mouse glutamatergic myenteric neurons. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.18.558146. [PMID: 37781576 PMCID: PMC10541117 DOI: 10.1101/2023.09.18.558146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/03/2023]
Abstract
The enteric nervous system (ENS) functions largely independently of the central nervous system (CNS). Correspondingly, glutamate, the dominant neurotransmitter in the CNS and sensory afferents, is not a primary neurotransmitter in the ENS. Only a fraction (approximately 2%) of myenteric neurons in the mouse distal colon and rectum (colorectum) are positive for vesicular glutamate transporter type 2 (VGLUT2), the structure and function of which remain undetermined. Here, we systematically characterized VGLUT2-positive enteric neurons (VGLUT2-ENs) through sparse labeling with adeno-associated virus, single-cell mRNA sequencing (scRNA-seq), and GCaMP6f calcium imaging. Our results reveal that the majority of VGLUT2-ENs (29 out of 31, 93.5%) exhibited Dogiel type I morphology with a single aborally projecting axon; most axons (26 out of 29, 89.7%) are between 4 and 10 mm long, each traversing 19 to 34 myenteric ganglia. These anatomical features exclude the VGLUT2-ENs from being intrinsic primary afferent or motor neurons. The scRNA-seq conducted on 52 VGLUT2-ENs suggests different expression profiles from conventional descending interneurons. Ex vivo GCaMP6f recordings from flattened colorectum indicate that almost all VGLUT2-EN (181 out of 215, 84.2%) are indirectly activated by colorectal stretch via nicotinic cholinergic neural transmission. In conclusion, VGLUT2-ENs are a functionally unique group of enteric neurons with single aborally projecting long axons that traverse multiple myenteric ganglia and are activated indirectly by colorectal mechanical stretch. This knowledge will provide a solid foundation for subsequent studies on the potential interactions of VGLUT2-EN with extrinsic colorectal afferents via glutamatergic neurotransmission. New & Noteworthy We reveal that VGLUT2-positive enteric neurons (EN), although constituting a small fraction of total EN, are homogeneously expressed in the myenteric ganglia, with a slight concentration at the intermediate region between the colon and rectum. This concentration coincides with the entry zone of extrinsic afferents into the colorectum. Given that VGLUT2-ENs are indirectly activated by colorectal mechanical stretch, they are likely to participate in visceral nociception through glutamatergic neural transmission with extrinsic afferents.
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8
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Robinson BG, Oster BA, Robertson K, Kaltschmidt JA. Loss of ASD-Related Molecule Cntnap2 Affects Colonic Motility in Mice. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.17.537221. [PMID: 37131706 PMCID: PMC10153124 DOI: 10.1101/2023.04.17.537221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Gastrointestinal (GI) symptoms are highly prevalent among individuals with autism spectrum disorder (ASD), but the molecular link between ASD and GI dysfunction remains poorly understood. The enteric nervous system (ENS) is critical for normal GI motility and has been shown to be altered in mouse models of ASD and other neurological disorders. Contactin-associated protein-like 2 (Cntnap2) is an ASD-related synaptic cell-adhesion molecule important for sensory processing. In this study, we examine the role of Cntnap2 in GI motility by characterizing Cntnap2's expression in the ENS and assessing GI function in Cntnap2 mutant mice. We find Cntnap2 expression predominately in enteric sensory neurons. We further assess in-vivo and ex-vivo GI motility in Cntnap2 mutants and show altered transit time and colonic motility patterns. The overall organization of the ENS appears undisturbed. Our results suggest that Cntnap2 plays a role in GI function and may provide a molecular link between ASD and GI dysfunction.
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Affiliation(s)
- Beatriz G. Robinson
- Wu Tsai Neurosciences Institute, Stanford University, Stanford, CA 94305, USA
- Neurosciences IDP Graduate Program, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Beau A. Oster
- Nevada ENDURE Program, University of Nevada, Reno, Reno, NV 89557, USA
| | - Keiramarie Robertson
- Wu Tsai Neurosciences Institute, Stanford University, Stanford, CA 94305, USA
- Neurosciences IDP Graduate Program, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Julia A. Kaltschmidt
- Wu Tsai Neurosciences Institute, Stanford University, Stanford, CA 94305, USA
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA 94305, USA
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9
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Chen BN, Humenick A, Yew WP, Peterson RA, Wiklendt L, Dinning PG, Spencer NJ, Wattchow DA, Costa M, Brookes SJH. Types of Neurons in the Human Colonic Myenteric Plexus Identified by Multilayer Immunohistochemical Coding. Cell Mol Gastroenterol Hepatol 2023; 16:573-605. [PMID: 37355216 PMCID: PMC10469081 DOI: 10.1016/j.jcmgh.2023.06.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 06/14/2023] [Accepted: 06/15/2023] [Indexed: 06/26/2023]
Abstract
BACKGROUND AND AIMS Gut functions including motility, secretion, and blood flow are largely controlled by the enteric nervous system. Characterizing the different classes of enteric neurons in the human gut is an important step to understand how its circuitry is organized and how it is affected by disease. METHODS Using multiplexed immunohistochemistry, 12 discriminating antisera were applied to distinguish different classes of myenteric neurons in the human colon (2596 neurons, 12 patients) according to their chemical coding. All antisera were applied to every neuron, in multiple layers, separated by elutions. RESULTS A total of 164 combinations of immunohistochemical markers were present among the 2596 neurons, which could be divided into 20 classes, with statistical validation. Putative functions were ascribed for 4 classes of putative excitatory motor neurons (EMN1-4), 4 inhibitory motor neurons (IMN1-4), 3 ascending interneurons (AIN1-3), 6 descending interneurons (DIN1-6), 2 classes of multiaxonal sensory neurons (SN1-2), and a small, miscellaneous group (1.8% of total). Soma-dendritic morphology was analyzed, revealing 5 common shapes distributed differentially between the 20 classes. Distinctive baskets of axonal varicosities surrounded 45% of myenteric nerve cell bodies and were associated with close appositions, suggesting possible connectivity. Baskets of cholinergic terminals and several other types of baskets selectively targeted ascending interneurons and excitatory motor neurons but were significantly sparser around inhibitory motor neurons. CONCLUSIONS Using a simple immunohistochemical method, human myenteric neurons were shown to comprise multiple classes based on chemical coding and morphology and dense clusters of axonal varicosities were selectively associated with some classes.
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Affiliation(s)
- Bao Nan Chen
- Human Physiology, College of Medicine and Public Health, Flinders University, Adelaide, South Australia, Australia
| | - Adam Humenick
- Human Physiology, College of Medicine and Public Health, Flinders University, Adelaide, South Australia, Australia
| | - Wai Ping Yew
- Human Physiology, College of Medicine and Public Health, Flinders University, Adelaide, South Australia, Australia
| | - Rochelle A Peterson
- Human Physiology, College of Medicine and Public Health, Flinders University, Adelaide, South Australia, Australia
| | - Lukasz Wiklendt
- Human Physiology, College of Medicine and Public Health, Flinders University, Adelaide, South Australia, Australia
| | - Phil G Dinning
- Human Physiology, College of Medicine and Public Health, Flinders University, Adelaide, South Australia, Australia; Colorectal Surgical Unit, Division of Surgery, Flinders Medical Centre, Bedford Park, South Australia, Australia
| | - Nick J Spencer
- Human Physiology, College of Medicine and Public Health, Flinders University, Adelaide, South Australia, Australia
| | - David A Wattchow
- Colorectal Surgical Unit, Division of Surgery, Flinders Medical Centre, Bedford Park, South Australia, Australia
| | - Marcello Costa
- Human Physiology, College of Medicine and Public Health, Flinders University, Adelaide, South Australia, Australia
| | - Simon J H Brookes
- Human Physiology, College of Medicine and Public Health, Flinders University, Adelaide, South Australia, Australia.
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10
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Sharkey KA, Mawe GM. The enteric nervous system. Physiol Rev 2023; 103:1487-1564. [PMID: 36521049 PMCID: PMC9970663 DOI: 10.1152/physrev.00018.2022] [Citation(s) in RCA: 58] [Impact Index Per Article: 58.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 12/12/2022] [Accepted: 12/15/2022] [Indexed: 12/23/2022] Open
Abstract
Of all the organ systems in the body, the gastrointestinal tract is the most complicated in terms of the numbers of structures involved, each with different functions, and the numbers and types of signaling molecules utilized. The digestion of food and absorption of nutrients, electrolytes, and water occurs in a hostile luminal environment that contains a large and diverse microbiota. At the core of regulatory control of the digestive and defensive functions of the gastrointestinal tract is the enteric nervous system (ENS), a complex system of neurons and glia in the gut wall. In this review, we discuss 1) the intrinsic neural control of gut functions involved in digestion and 2) how the ENS interacts with the immune system, gut microbiota, and epithelium to maintain mucosal defense and barrier function. We highlight developments that have revolutionized our understanding of the physiology and pathophysiology of enteric neural control. These include a new understanding of the molecular architecture of the ENS, the organization and function of enteric motor circuits, and the roles of enteric glia. We explore the transduction of luminal stimuli by enteroendocrine cells, the regulation of intestinal barrier function by enteric neurons and glia, local immune control by the ENS, and the role of the gut microbiota in regulating the structure and function of the ENS. Multifunctional enteric neurons work together with enteric glial cells, macrophages, interstitial cells, and enteroendocrine cells integrating an array of signals to initiate outputs that are precisely regulated in space and time to control digestion and intestinal homeostasis.
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Affiliation(s)
- Keith A Sharkey
- Hotchkiss Brain Institute and Snyder Institute for Chronic Diseases, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Gary M Mawe
- Department of Neurological Sciences, Larner College of Medicine, University of Vermont, Burlington, Vermont
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11
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Al Doghmi A, Barta BP, Egyed-Kolumbán A, Onhausz B, Kiss S, Balázs J, Szalai Z, Bagyánszki M, Bódi N. Gut Region-Specific Interleukin 1β Induction in Different Myenteric Neuronal Subpopulations of Type 1 Diabetic Rats. Int J Mol Sci 2023; 24:ijms24065804. [PMID: 36982878 PMCID: PMC10064852 DOI: 10.3390/ijms24065804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Revised: 03/13/2023] [Accepted: 03/16/2023] [Indexed: 03/30/2023] Open
Abstract
Interleukin 1β (IL1β) is a pro-inflammatory cytokine that may play a crucial role in enteric neuroinflammation in type 1 diabetes. Therefore, our goal is to evaluate the effects of chronic hyperglycemia and insulin treatment on IL1β immunoreactivity in myenteric neurons and their different subpopulations along the duodenum-ileum-colon axis. Fluorescent immunohistochemistry was used to count IL1β expressing neurons as well as the neuronal nitric oxide synthase (nNOS)- and calcitonin gene-related peptide (CGRP)-immunoreactive myenteric neurons within this group. Tissue IL1β level was measured by ELISA in muscle/myenteric plexus-containing homogenates. IL1β mRNA was detected by RNAscope in different intestinal layers. The proportion of IL1β-immunoreactive myenteric neurons was significantly higher in the colon than in the small intestine of controls. In diabetics, this proportion significantly increased in all gut segments, which was prevented by insulin treatment. The proportion of IL1β-nNOS-immunoreactive neurons only increased in the diabetic colon, while the proportion of IL1β-CGRP-immunoreactive neurons only increased in the diabetic ileum. Elevated IL1β levels were also confirmed in tissue homogenates. IL1β mRNA induction was detected in the myenteric ganglia, smooth muscle and intestinal mucosa of diabetics. These findings support that diabetes-related IL1β induction is specific for the different myenteric neuronal subpopulations, which may contribute to diabetic motility disturbances.
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Affiliation(s)
- Afnan Al Doghmi
- Department of Physiology, Anatomy and Neuroscience, University of Szeged, 6726 Szeged, Hungary
| | - Bence Pál Barta
- Department of Physiology, Anatomy and Neuroscience, University of Szeged, 6726 Szeged, Hungary
| | - Abigél Egyed-Kolumbán
- Department of Physiology, Anatomy and Neuroscience, University of Szeged, 6726 Szeged, Hungary
| | - Benita Onhausz
- Department of Physiology, Anatomy and Neuroscience, University of Szeged, 6726 Szeged, Hungary
| | - Szilvia Kiss
- Department of Physiology, Anatomy and Neuroscience, University of Szeged, 6726 Szeged, Hungary
| | - János Balázs
- Department of Physiology, Anatomy and Neuroscience, University of Szeged, 6726 Szeged, Hungary
| | - Zita Szalai
- Department of Physiology, Anatomy and Neuroscience, University of Szeged, 6726 Szeged, Hungary
| | - Mária Bagyánszki
- Department of Physiology, Anatomy and Neuroscience, University of Szeged, 6726 Szeged, Hungary
| | - Nikolett Bódi
- Department of Physiology, Anatomy and Neuroscience, University of Szeged, 6726 Szeged, Hungary
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12
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Edwards BS, Stiglitz ES, Davis BM, Smith-Edwards KM. Abnormal enteric nervous system and motor activity in the ganglionic proximal bowel of Hirschsprung's disease. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.08.531750. [PMID: 36945585 PMCID: PMC10028932 DOI: 10.1101/2023.03.08.531750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2023]
Abstract
Hirschsprung's disease (HSCR) is a congenital defect in which the enteric nervous system (ENS) does not develop in the distal bowel, requiring surgical removal of the portions of bowel without ENS ganglia ('aganglionic') and reattachment of the 'normal' proximal bowel with ENS ganglia. Unfortunately, many HSCR patients have persistent dysmotility (e.g., constipation, incontinence) and enterocolitis after surgery, suggesting that the remaining bowel is not normal despite having ENS ganglia. Anatomical and neurochemical alterations have been observed in the ENS-innervated proximal bowel from HSCR patients and mice, but no studies have recorded ENS activity to define the circuit mechanisms underlying post-surgical HSCR dysfunction. Here, we generated a HSCR mouse model with a genetically-encoded calcium indicator to map the ENS connectome in the proximal colon. We identified abnormal spontaneous and synaptic ENS activity in proximal colons from GCaMP-Ednrb -/- mice with HSCR that corresponded to motor dysfunction. Many HSCR-associated defects were also observed in GCaMP-Ednrb +/- mice, despite complete ENS innervation. Results suggest that functional abnormalities in the ENS-innervated bowel contribute to post-surgical bowel complications in HSCR patients, and HSCR-related mutations that do not cause aganglionosis may cause chronic colon dysfunction in patients without a HSCR diagnosis.
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13
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Nakanishi S, Mantani Y, Ohno N, Morishita R, Yokoyama T, Hoshi N. Histological study on regional specificity of the mucosal nerve network in the rat large intestine. J Vet Med Sci 2023; 85:123-134. [PMID: 36517005 PMCID: PMC10017283 DOI: 10.1292/jvms.22-0433] [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: 12/14/2022] Open
Abstract
Our previous studies and others have revealed detailed characteristics of the mucosal nerve network in the small intestine, but much remains unknown about the corresponding network in the large intestine. We herein investigated regional differences in the expression of neurochemical markers, the nerve network structure, and the cells in contact with nerve fibers by histological analysis using both immunohistochemistry and serial block-face scanning electron microscopy (SBF-SEM). Immunohistochemistry revealed that immunopositive structures for protein gene product 9.5, vasoactive intestinal peptide (VIP), calretinin and vesicular acetylcholine transporter were more prevalent in the lamina propria of the ascending colon than the cecum and descending colon (DC). There was no significant difference in the frequency of most neurochemical markers between the cecum and DC, but the frequencies of VIP+ structures were higher in the cecum than in the DC. SBF-SEM analysis showed that the nerve network structure was more developed on the luminal side of the DC than the cecum. The cells that nerve fibers abundantly contacted were subepithelial and lamina propria fibroblast-like cells and macrophages. In addition, nerve fibers in the cecum were in more frequent contact with immune cells such as macrophages and plasma cells than nerve fibers in the DC. Thus, the present histological analysis suggested that the mucosal nerve network in the large intestine possessed both regional universality and various specificities, and revealed the intimate relationship between the nerve network and immune cells, especially in the cecum.
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Affiliation(s)
- Satoki Nakanishi
- Laboratory of Histophysiology, Department of Bioresource Science, Graduate School of Agricultural Science, Kobe University, Hyogo, Japan
| | - Youhei Mantani
- Laboratory of Histophysiology, Department of Bioresource Science, Graduate School of Agricultural Science, Kobe University, Hyogo, Japan
| | - Nobuhiko Ohno
- Department of Anatomy, Division of Histology and Cell Biology, Jichi Medical University, School of Medicine, Tochigi, Japan.,Division of Ultrastructural Research, National Institute for Physiological Sciences, Aichi, Japan
| | - Rinako Morishita
- Laboratory of Histophysiology, Department of Bioresource Science, Graduate School of Agricultural Science, Kobe University, Hyogo, Japan
| | - Toshifumi Yokoyama
- Laboratory of Animal Molecular Morphology, Department of Bioresource Science, Graduate School of Agricultural Science, Kobe University, Hyogo, Japan
| | - Nobuhiko Hoshi
- Laboratory of Animal Molecular Morphology, Department of Bioresource Science, Graduate School of Agricultural Science, Kobe University, Hyogo, Japan
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14
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Salami AT, Oyagbemi AA, Alabi MV, Olaleye SB. Naringenin modulates Cobalt activities on gut motility through mechanosensors and serotonin signalling. Biomarkers 2023; 28:11-23. [PMID: 36250715 DOI: 10.1080/1354750x.2022.2137235] [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: 01/26/2023]
Abstract
IntroductionCobalt chloride-(CoCl2) exerts beneficial and toxic activities depending on dose however Naringenin-(Nar) a flavonoid, chelates heavy metals. Absorption of ingested heavy metals, or chelates are dependent on gut motility (gastric emptying and intestinal transit time) and mechanosensor regulation. Literature is vague on CoCl2 activities on gut motility and mechanosensor nor probable chelating actions with naringenin which was investigated in this study.MethodOne hundred male Wistar rats were grouped viz; A to D (25, 62, 150 and 300 mg/kg CoCl2), E to H doses of CoCl2+Nar (50 mg/kg), I-Narigenin and J-Control. Gastric emptying and intestinal transit time were evaluated by day eight, intestinal tissue assayed for biochemical, histological and immunohistochemistry reactivity.ResultCoCl2 significantly increased Gastric emptying (150 and 300 mg/kg) and Intestinal transit time unlike Naringenin. CoCl2 (150 mg/kg) significantly increased Catalase and Nitric oxide but ameliorated by Naringenin. ATPase activities significantly increased in 150 mg/kg-CoCl2 but ameliorated by Naringenin. Carbonyl levels increased in all CoCl2+Nar groups. High Enterochromaffin-cell count in 25 and 62 mg/kg-CoCl2 were ameliorated by Naringenin. Serotonin immunoreactivity increased in CoCl2 (25, 62, 300 mg/kg) but reduced in CoCl2+Nar groups.ConclusionCobalt chloride enhanced gastric motility via increased mechanosensor activities and serotonin expression at low doses. Naringenin ameliorated toxicity of high cobalt chloride via metal-flavonoid chelates.
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Affiliation(s)
- Adeola Temitope Salami
- Gastrointestinal Secretion and Inflammation Research Unit, Department of Physiology, Faculty of Basic Medical Sciences, University of Ibadan, Ibadan, Nigeria
| | - Ademola Adetokubo Oyagbemi
- Cardiorenal Laboratory, Department of Veterinary Physiology and Biochemistry, Faculty of Veterinary Medicine, University of Ibadan, Ibadan, Nigeria
| | - Moyosore Victoria Alabi
- Gastrointestinal Secretion and Inflammation Research Unit, Department of Physiology, Faculty of Basic Medical Sciences, University of Ibadan, Ibadan, Nigeria
| | - Samuel Babafemi Olaleye
- Gastrointestinal Secretion and Inflammation Research Unit, Department of Physiology, Faculty of Basic Medical Sciences, University of Ibadan, Ibadan, Nigeria
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15
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Takla M, Saadeh K, Tse G, Huang CLH, Jeevaratnam K. Ageing and the Autonomic Nervous System. Subcell Biochem 2023; 103:201-252. [PMID: 37120470 DOI: 10.1007/978-3-031-26576-1_10] [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: 05/01/2023]
Abstract
The vertebrate nervous system is divided into central (CNS) and peripheral (PNS) components. In turn, the PNS is divided into the autonomic (ANS) and enteric (ENS) nervous systems. Ageing implicates time-related changes to anatomy and physiology in reducing organismal fitness. In the case of the CNS, there exists substantial experimental evidence of the effects of age on individual neuronal and glial function. Although many such changes have yet to be experimentally observed in the PNS, there is considerable evidence of the role of ageing in the decline of ANS function over time. As such, this chapter will argue that the ANS constitutes a paradigm for the physiological consequences of ageing, as well as for their clinical implications.
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Affiliation(s)
| | | | - Gary Tse
- Kent and Medway Medical School, Canterbury, UK
- University of Surrey, Guildford, UK
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16
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Kuehs S, Teege L, Hellberg AK, Stanke C, Haag N, Kurth I, Blum R, Nau C, Leipold E. Isolation and transfection of myenteric neurons from mice for patch-clamp applications. Front Mol Neurosci 2022; 15:1076187. [PMID: 36618826 PMCID: PMC9810798 DOI: 10.3389/fnmol.2022.1076187] [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: 10/21/2022] [Accepted: 12/05/2022] [Indexed: 12/24/2022] Open
Abstract
The enteric nervous system (ENS) is a complex neuronal network organized in ganglionated plexuses that extend along the entire length of the gastrointestinal tract. Largely independent of the central nervous system, the ENS coordinates motility and peristalsis of the digestive tract, regulates secretion and absorption, and is involved in immunological processes. Electrophysiological methods such as the patch-clamp technique are particularly suitable to study the function of neurons as well as the biophysical parameters of the underlying ion channels under both physiological and pathophysiological conditions. However, application of the patch-clamp method to ENS neurons remained difficult because they are embedded in substantial tissue layers that limit access to and targeted manipulation of these cells. Here, we present a robust step-by-step protocol that involves isolation of ENS neurons from adult mice, culturing of the cells, their transfection with plasmid DNA, and subsequent electrophysiological characterization of individual neurons in current-clamp and voltage-clamp recordings. With this protocol, ENS neurons can be prepared, transfected, and electrophysiologically characterized within 72 h. Using isolated ENS neurons, we demonstrate the feasibility of the approach by functional overexpression of recombinant voltage-gated NaV1.9 mutant channels associated with hereditary sensory and autonomic neuropathy type 7 (HSAN-7), a disorder characterized by congenital analgesia and severe constipation that can require parenteral nutrition. Although our focus is on the electrophysiological evaluation of isolated ENS neurons, the presented methodology is also useful to analyze molecules other than sodium channels or to apply alternative downstream assays including calcium imaging, proteomic and nucleic acid approaches, or immunochemistry.
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Affiliation(s)
- Samuel Kuehs
- Department of Anesthesiology and Intensive Care, Center of Brain, Behavior and Metabolism (CBBM), University of Lübeck, Lübeck, Germany
| | - Laura Teege
- Department of Anesthesiology and Intensive Care, Center of Brain, Behavior and Metabolism (CBBM), University of Lübeck, Lübeck, Germany
| | - Ann-Katrin Hellberg
- Department of Anesthesiology and Intensive Care, Center of Brain, Behavior and Metabolism (CBBM), University of Lübeck, Lübeck, Germany
| | - Christina Stanke
- Department of Anesthesiology and Intensive Care, Center of Brain, Behavior and Metabolism (CBBM), University of Lübeck, Lübeck, Germany
| | - Natja Haag
- Institute for Human Genetics and Genomic Medicine, Medical Faculty, Rhine-Westphalia Technical University of Aachen, Aachen, Germany,Institute of Physiology, Medical Faculty, Rhine-Westphalia Technical University of Aachen, Aachen, Germany
| | - Ingo Kurth
- Institute for Human Genetics and Genomic Medicine, Medical Faculty, Rhine-Westphalia Technical University of Aachen, Aachen, Germany
| | - Robert Blum
- Department of Neurology, University Hospital of Würzburg, Würzburg, Germany
| | - Carla Nau
- Department of Anesthesiology and Intensive Care, Center of Brain, Behavior and Metabolism (CBBM), University of Lübeck, Lübeck, Germany
| | - Enrico Leipold
- Department of Anesthesiology and Intensive Care, Center of Brain, Behavior and Metabolism (CBBM), University of Lübeck, Lübeck, Germany,*Correspondence: Enrico Leipold,
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17
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Piletz JE, Cooper J, Chidester K, Erson K, Melton S, Osemeka A, Patterson M, Strickland K, Wan JX, Williams K. Transepithelial Effect of Probiotics in a Novel Model of Gut Lumen to Nerve Signaling. Nutrients 2022; 14:nu14224856. [PMID: 36432542 PMCID: PMC9697698 DOI: 10.3390/nu14224856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 10/31/2022] [Accepted: 11/03/2022] [Indexed: 11/18/2022] Open
Abstract
Recent studies have shown that the gut microbiome changes brain function, behavior, and psychiatric and neurological disorders. The Gut-Brain Axis (GBA) provides a neuronal pathway to explain this. But exactly how do commensal bacteria signal through the epithelial layer of the large intestine to activate GBA nerve afferents? An in vitro model is described. We differentiated two human cell lines: Caco2Bbe1 into mature epithelium on 0.4-micron filters and then SH-SY5Y into mature neurons in 24-well plates. These were co-cultured by placing the epithelium-laden filters 1 mm above the neurons. Twenty-four hours later they were tri-cultured by apical addition of 107Lactobacillus rhamnosus or Lactobacillus fermentum which settled on the epithelium. Alone, the Caco2bbe1 cells stimulated neurite outgrowth in underlying SH-SY5Y. Beyond this, the lactobacilli were well tolerated and stimulated further neurite outgrowth by 24 h post-treatment, though not passing through the filters. The results provide face validity for a first-of-kind model of transepithelial intestinal lumen-to nerve signaling. The model displays the tight junctional barrier characteristics found in the large intestine while at the same time translating stimulatory signals from the bacteria through epithelial cells to attracted neurons. The model is easy to set-up with components widely available.
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Affiliation(s)
- John E. Piletz
- Office of Global Education, Mississippi College, Clinton, MS 39058, USA
- Department of Biology, Mississippi College, Clinton, MS 39058, USA
- Correspondence: ; Tel.: +1-(601)-925-7762 or +1-601-853-0966
| | - Jason Cooper
- Department of Biology, Mississippi College, Clinton, MS 39058, USA
| | - Kevin Chidester
- Department of Biology, Mississippi College, Clinton, MS 39058, USA
| | - Kyle Erson
- Department of Biology, Mississippi College, Clinton, MS 39058, USA
| | - Sydney Melton
- Department of Biology, Mississippi College, Clinton, MS 39058, USA
| | - Anthony Osemeka
- Department of Biology, Mississippi College, Clinton, MS 39058, USA
| | - Megan Patterson
- Department of Biology, Mississippi College, Clinton, MS 39058, USA
| | | | - Jing Xuan Wan
- Department of Biology, Mississippi College, Clinton, MS 39058, USA
| | - Kaitlin Williams
- Department of Biology, Mississippi College, Clinton, MS 39058, USA
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18
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Baker PA, Ibarra-García-Padilla R, Venkatesh A, Singleton EW, Uribe RA. In toto imaging of early enteric nervous system development reveals that gut colonization is tied to proliferation downstream of Ret. Development 2022; 149:278609. [PMID: 36300492 PMCID: PMC9686996 DOI: 10.1242/dev.200668] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 09/27/2022] [Indexed: 01/19/2023]
Abstract
The enteric nervous system is a vast intrinsic network of neurons and glia within the gastrointestinal tract and is largely derived from enteric neural crest cells (ENCCs) that emigrate into the gut during vertebrate embryonic development. Study of ENCC migration dynamics and their genetic regulators provides great insights into fundamentals of collective cell migration and nervous system formation, and these are pertinent subjects for study due to their relevance to the human congenital disease Hirschsprung disease (HSCR). For the first time, we performed in toto gut imaging and single-cell generation tracing of ENCC migration in wild type and a novel ret heterozygous background zebrafish (retwmr1/+) to gain insight into ENCC dynamics in vivo. We observed that retwmr1/+ zebrafish produced fewer ENCCs localized along the gut, and these ENCCs failed to reach the hindgut, resulting in HSCR-like phenotypes. Specifically, we observed a proliferation-dependent migration mechanism, where cell divisions were associated with inter-cell distances and migration speed. Lastly, we detected a premature neuronal differentiation gene expression signature in retwmr1/+ ENCCs. These results suggest that Ret signaling may regulate maintenance of a stem state in ENCCs.
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Affiliation(s)
- Phillip A. Baker
- BioSciences Department, Rice University, Houston, TX 77005, USA,Biochemistry and Cell Biology Program, Rice University, Houston, TX 77005, USA
| | - Rodrigo Ibarra-García-Padilla
- BioSciences Department, Rice University, Houston, TX 77005, USA,Biochemistry and Cell Biology Program, Rice University, Houston, TX 77005, USA
| | | | | | - Rosa. A. Uribe
- BioSciences Department, Rice University, Houston, TX 77005, USA,Biochemistry and Cell Biology Program, Rice University, Houston, TX 77005, USA,Author for correspondence ()
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19
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Schneider KM, Kim J, Bahnsen K, Heuckeroth RO, Thaiss CA. Environmental perception and control of gastrointestinal immunity by the enteric nervous system. Trends Mol Med 2022; 28:989-1005. [PMID: 36208986 DOI: 10.1016/j.molmed.2022.09.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 05/25/2022] [Accepted: 09/07/2022] [Indexed: 12/12/2022]
Abstract
The enteric nervous system (ENS) forms a versatile sensory system along the gastrointestinal tract that interacts with most cell types in the bowel. Herein, we portray host-environment interactions at the intestinal mucosal surface through the lens of the enteric nervous system. We describe local cellular interactions as well as long-range circuits between the enteric, central, and peripheral nervous systems. Additionally, we discuss recently discovered mechanisms by which enteric neurons and glia respond to biotic and abiotic environmental changes and how they regulate intestinal immunity and inflammation. The enteric nervous system emerges as an integrative sensory system with manifold immunoregulatory functions under both homeostatic and pathophysiological conditions.
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Affiliation(s)
- Kai Markus Schneider
- Microbiology Department, Institute for Immunology, Perelman School of Medicine, University of Pennsylvania, PA, USA; Institute for Diabetes, Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, PA, USA
| | - Jihee Kim
- Microbiology Department, Institute for Immunology, Perelman School of Medicine, University of Pennsylvania, PA, USA; Institute for Diabetes, Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, PA, USA
| | - Klaas Bahnsen
- Microbiology Department, Institute for Immunology, Perelman School of Medicine, University of Pennsylvania, PA, USA; Institute for Diabetes, Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, PA, USA
| | - Robert O Heuckeroth
- Department of Pediatrics, Children's Hospital of Philadelphia Research Institute, University of Pennsylvania, Philadelphia, PA 19104, USA; Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Christoph A Thaiss
- Microbiology Department, Institute for Immunology, Perelman School of Medicine, University of Pennsylvania, PA, USA; Institute for Diabetes, Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, PA, USA.
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20
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Poon SSB, Hung LY, Wu Q, Parathan P, Yalcinkaya N, Haag A, Luna RA, Bornstein JC, Savidge TC, Foong JPP. Neonatal antibiotics have long term sex-dependent effects on the enteric nervous system. J Physiol 2022; 600:4303-4323. [PMID: 36082768 PMCID: PMC9826436 DOI: 10.1113/jp282939] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2022] [Accepted: 07/18/2022] [Indexed: 01/12/2023] Open
Abstract
Infants and young children receive the highest exposures to antibiotics globally. Although there is building evidence that early life exposure to antibiotics increases susceptibility to various diseases including gut disorders later in life, the lasting impact of early life antibiotics on the physiology of the gut and its enteric nervous system (ENS) remains unclear. We treated neonatal mice with the antibiotic vancomycin during their first 10 postnatal days, then examined potential lasting effects of the antibiotic treatment on their colons during young adulthood (6 weeks old). We found that neonatal vancomycin treatment disrupted the gut functions of young adult female and male mice differently. Antibiotic-exposed females had significantly longer whole gut transit while antibiotic-treated males had significantly lower faecal weights compared to controls. Both male and female antibiotic-treated mice had greater percentages of faecal water content. Neonatal vancomycin treatment also had sexually dimorphic impacts on the neurochemistry and Ca2+ activity of young adult myenteric and submucosal neurons. Myenteric neurons of male mice were more disrupted than those of females, while opposing changes in submucosal neurons were seen in each sex. Neonatal vancomycin also induced sustained changes in colonic microbiota and lasting depletion of mucosal serotonin (5-HT) levels. Antibiotic impacts on microbiota and mucosal 5-HT were not sex-dependent, but we propose that the responses of the host to these changes are sex-specific. This first demonstration of long-term impacts of neonatal antibiotics on the ENS, gut microbiota and mucosal 5-HT has important implications for gut function and other physiological systems of the host. KEY POINTS: Early life exposure to antibiotics can increase susceptibility to diseases including functional gastrointestinal (GI) disorders later in life. Yet, the lasting impact of this common therapy on the gut and its enteric nervous system (ENS) remains unclear. We investigated the long-term impact of neonatal antibiotic treatment by treating mice with the antibiotic vancomycin during their neonatal period, then examining their colons during young adulthood. Adolescent female mice given neonatal vancomycin treatment had significantly longer whole gut transit times, while adolescent male and female mice treated with neonatal antibiotics had significantly wetter stools. Effects of neonatal vancomycin treatment on the neurochemistry and Ca2+ activity of myenteric and submucosal neurons were sexually dimorphic. Neonatal vancomycin also had lasting effects on the colonic microbiome and mucosal serotonin biosynthesis that were not sex-dependent. Different male and female responses to antibiotic-induced disruptions of the ENS, microbiota and mucosal serotonin biosynthesis can lead to sex-specific impacts on gut function.
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Affiliation(s)
- Sabrina S. B. Poon
- Department of Anatomy and PhysiologyThe University of MelbourneParkvilleVictoriaAustralia
| | - Lin Y. Hung
- Department of Anatomy and PhysiologyThe University of MelbourneParkvilleVictoriaAustralia
| | - Qinglong Wu
- Department of Pathology & ImmunologyBaylor College of MedicineHoustonTXUSA
- Texas Children's Microbiome CenterTexas Children's HospitalHoustonTXUSA
| | - Pavitha Parathan
- Department of Anatomy and PhysiologyThe University of MelbourneParkvilleVictoriaAustralia
| | - Nazli Yalcinkaya
- Department of Pathology & ImmunologyBaylor College of MedicineHoustonTXUSA
- Texas Children's Microbiome CenterTexas Children's HospitalHoustonTXUSA
| | - Anthony Haag
- Department of Pathology & ImmunologyBaylor College of MedicineHoustonTXUSA
- Texas Children's Microbiome CenterTexas Children's HospitalHoustonTXUSA
| | - Ruth Ann Luna
- Department of Pathology & ImmunologyBaylor College of MedicineHoustonTXUSA
- Texas Children's Microbiome CenterTexas Children's HospitalHoustonTXUSA
| | - Joel C. Bornstein
- Department of Anatomy and PhysiologyThe University of MelbourneParkvilleVictoriaAustralia
| | - Tor C. Savidge
- Department of Pathology & ImmunologyBaylor College of MedicineHoustonTXUSA
- Texas Children's Microbiome CenterTexas Children's HospitalHoustonTXUSA
| | - Jaime P. P. Foong
- Department of Anatomy and PhysiologyThe University of MelbourneParkvilleVictoriaAustralia
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21
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Zeng W, Yang F, Shen WL, Zhan C, Zheng P, Hu J. Interactions between central nervous system and peripheral metabolic organs. SCIENCE CHINA. LIFE SCIENCES 2022; 65:1929-1958. [PMID: 35771484 DOI: 10.1007/s11427-021-2103-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 04/07/2022] [Indexed: 02/08/2023]
Abstract
According to Descartes, minds and bodies are distinct kinds of "substance", and they cannot have causal interactions. However, in neuroscience, the two-way interaction between the brain and peripheral organs is an emerging field of research. Several lines of evidence highlight the importance of such interactions. For example, the peripheral metabolic systems are overwhelmingly regulated by the mind (brain), and anxiety and depression greatly affect the functioning of these systems. Also, psychological stress can cause a variety of physical symptoms, such as bone loss. Moreover, the gut microbiota appears to play a key role in neuropsychiatric and neurodegenerative diseases. Mechanistically, as the command center of the body, the brain can regulate our internal organs and glands through the autonomic nervous system and neuroendocrine system, although it is generally considered to be outside the realm of voluntary control. The autonomic nervous system itself can be further subdivided into the sympathetic and parasympathetic systems. The sympathetic division functions a bit like the accelerator pedal on a car, and the parasympathetic division functions as the brake. The high center of the autonomic nervous system and the neuroendocrine system is the hypothalamus, which contains several subnuclei that control several basic physiological functions, such as the digestion of food and regulation of body temperature. Also, numerous peripheral signals contribute to the regulation of brain functions. Gastrointestinal (GI) hormones, insulin, and leptin are transported into the brain, where they regulate innate behaviors such as feeding, and they are also involved in emotional and cognitive functions. The brain can recognize peripheral inflammatory cytokines and induce a transient syndrome called sick behavior (SB), characterized by fatigue, reduced physical and social activity, and cognitive impairment. In summary, knowledge of the biological basis of the interactions between the central nervous system and peripheral organs will promote the full understanding of how our body works and the rational treatment of disorders. Thus, we summarize current development in our understanding of five types of central-peripheral interactions, including neural control of adipose tissues, energy expenditure, bone metabolism, feeding involving the brain-gut axis and gut microbiota. These interactions are essential for maintaining vital bodily functions, which result in homeostasis, i.e., a natural balance in the body's systems.
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Affiliation(s)
- Wenwen Zeng
- Institute for Immunology, and Department of Basic Medical Sciences, School of Medicine, Tsinghua University, Beijing, 100084, China. .,Tsinghua-Peking Center for Life Sciences, Beijing, 100084, China. .,Beijing Key Laboratory for Immunological Research on Chronic Diseases, Beijing, 100084, China.
| | - Fan Yang
- The Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, 518055, China.
| | - Wei L Shen
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China.
| | - Cheng Zhan
- Department of Hematology, The First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230026, China. .,National Institute of Biological Sciences, Beijing, 102206, China. .,Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing, 100084, China.
| | - Peng Zheng
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, 400042, China. .,Institute of Neuroscience and the Collaborative Innovation Center for Brain Science, Chongqing Medical University, Chongqing, 400016, China. .,Chongqing Key Laboratory of Neurobiology, Chongqing, 400016, China.
| | - Ji Hu
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
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22
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Hibberd TJ, Yew WP, Dodds KN, Xie Z, Travis L, Brookes SJ, Costa M, Hu H, Spencer NJ. Quantification of CGRP-immunoreactive myenteric neurons in mouse colon. J Comp Neurol 2022; 530:3209-3225. [PMID: 36043843 DOI: 10.1002/cne.25403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2022] [Revised: 08/08/2022] [Accepted: 08/17/2022] [Indexed: 11/07/2022]
Abstract
Quantitative data of biological systems provide valuable baseline information for understanding pathology, experimental perturbations, and computational modeling. In mouse colon, calcitonin gene-related peptide (CGRP) is expressed by myenteric neurons with multiaxonal (Dogiel type II) morphology, characteristic of intrinsic primary afferent neurons (IPANs). Analogous neurons in other species and gut regions represent 5-35% of myenteric neurons. We aimed to quantify proportions of CGRP-immunopositive (CGRP+) myenteric neurons. Colchicine-treated wholemount preparations of proximal, mid, and distal colon were labeled for HuC/D, CGRP, nitric oxide synthase (NOS), and peripherin (Per). The pan-neuronal markers (Hu+/Per+) co-labeled 94% of neurons. Hu+/Per- neurons comprised ∼6%, but Hu-/Per+ cells were rare. Thus, quantification was based on Hu+ myenteric neurons (8576 total; 1225 ± 239 per animal, n = 7). CGRP+ cell bodies were significantly larger than the average of all Hu+ neurons (329 ± 13 vs. 261 ± 12 μm2 , p < .0001). CGRP+ neurons comprised 19% ± 3% of myenteric neurons without significant regional variation. NOS+ neurons comprised 42% ± 2% of myenteric neurons overall, representing a lower proportion in proximal colon, compared to mid and distal colon (38% ± 2%, 44% ± 2%, and 44% ± 3%, respectively). Peripherin immunolabeling revealed cell body and axonal morphology in some myenteric neurons. Whether all CGRP+ neurons were multiaxonal could not be addressed using peripherin immunolabeling. However, of 118 putatively multiaxonal neurons first identified based on peripherin immunoreactivity, all were CGRP+ (n = 4). In conclusion, CGRP+ myenteric neurons in mouse colon were comprehensively quantified, occurring within a range expected of a putative IPAN marker. All Per+ multiaxonal neurons, characteristic of Dogiel type II/IPAN morphology, were CGRP+.
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Affiliation(s)
- Timothy J Hibberd
- College of Medicine and Public Health, Flinders Health and Medical Research Institute, Flinders University, Adelaide, South Australia, Australia
| | - Wai Ping Yew
- College of Medicine and Public Health, Flinders Health and Medical Research Institute, Flinders University, Adelaide, South Australia, Australia
| | - Kelsi N Dodds
- College of Medicine and Public Health, Flinders Health and Medical Research Institute, Flinders University, Adelaide, South Australia, Australia
| | - Zili Xie
- Department of Anesthesiology, The Center for the Study of Itch & Sensory Disorders, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Lee Travis
- College of Medicine and Public Health, Flinders Health and Medical Research Institute, Flinders University, Adelaide, South Australia, Australia
| | - Simon J Brookes
- College of Medicine and Public Health, Flinders Health and Medical Research Institute, Flinders University, Adelaide, South Australia, Australia
| | - Marcello Costa
- College of Medicine and Public Health, Flinders Health and Medical Research Institute, Flinders University, Adelaide, South Australia, Australia
| | - Hongzhen Hu
- Department of Anesthesiology, The Center for the Study of Itch & Sensory Disorders, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Nick J Spencer
- College of Medicine and Public Health, Flinders Health and Medical Research Institute, Flinders University, Adelaide, South Australia, Australia
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Mercado-Perez A, Beyder A. Gut feelings: mechanosensing in the gastrointestinal tract. Nat Rev Gastroenterol Hepatol 2022; 19:283-296. [PMID: 35022607 PMCID: PMC9059832 DOI: 10.1038/s41575-021-00561-y] [Citation(s) in RCA: 48] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/22/2021] [Indexed: 12/11/2022]
Abstract
The primary function of the gut is to procure nutrients. Synchronized mechanical activities underlie nearly all its endeavours. Coordination of mechanical activities depends on sensing of the mechanical forces, in a process called mechanosensation. The gut has a range of mechanosensory cells. They function either as specialized mechanoreceptors, which convert mechanical stimuli into coordinated physiological responses at the organ level, or as non-specialized mechanosensory cells that adjust their function based on the mechanical state of their environment. All major cell types in the gastrointestinal tract contain subpopulations that act as specialized mechanoreceptors: epithelia, smooth muscle, neurons, immune cells, and others. These cells are tuned to the physical properties of the surrounding tissue, so they can discriminate mechanical stimuli from the baseline mechanical state. The importance of gastrointestinal mechanosensation has long been recognized, but the latest discoveries of molecular identities of mechanosensors and technical advances that resolve the relevant circuitry have poised the field to make important intellectual leaps. This Review describes the mechanical factors relevant for normal function, as well as the molecules, cells and circuits involved in gastrointestinal mechanosensing. It concludes by outlining important unanswered questions in gastrointestinal mechanosensing.
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Affiliation(s)
- Arnaldo Mercado-Perez
- Enteric NeuroScience Program (ENSP), Division of Gastroenterology & Hepatology, Mayo Clinic, Rochester, MN, USA
- Medical Scientist Training Program (MSTP), Mayo Clinic, Rochester, MN, USA
| | - Arthur Beyder
- Enteric NeuroScience Program (ENSP), Division of Gastroenterology & Hepatology, Mayo Clinic, Rochester, MN, USA.
- Department of Physiology & Biomedical Engineering, Mayo Clinic, Rochester, MN, USA.
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24
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DeSesso JM. Comparative anatomy, pre- and postnatal changes during the development and maturation of the small intestine: Life-stage influences on exposure. Birth Defects Res 2022; 114:449-466. [PMID: 35451574 DOI: 10.1002/bdr2.2015] [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: 02/16/2022] [Revised: 04/04/2022] [Accepted: 04/05/2022] [Indexed: 11/08/2022]
Abstract
The gastrointestinal (GI) system absorbs nutrients and xenobiotics, excretes waste, and performs immunologic and endocrine functions. The subdivisions of the mature gut and the complexity of their corrugated, absorptive luminal surfaces differ greatly among mammals. Regardless, the embryonic gut tube in all mammalian species arises when cephalocaudal folding incorporates the roof of the yolk sac into the embryo. The gut tube quickly lengthens and bulges into the umbilical cord. Upon reentry into the abdominal cavity, the gut tube begins to differentiate-a process that continues until well into the lactation period. Differentiation of the small intestine involves (1) increasing the absorptive surface area of the lumen; (2) establishing mechanisms to control the pH of luminal contents; (3) forming a hierarchical vascular system for distribution of absorbed nutrients; (4) developing a complex enteric nervous system to control motility; (5) providing a system for replenishment of cells; and (6) contributing to the immunity of the organism. Because the length of gestation varies among species typically used in safety tests and is much shorter than human gestation, the state of GI maturation at the time of parturition differs significantly. Differences in GI maturation can contribute to species differences in the rate and extent of absorption; these differences must be considered when designing and interpreting pharmacological/toxicological studies and extrapolating safety test results to humans.
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Affiliation(s)
- John M DeSesso
- Health Sciences Center, Exponent, Inc, Alexandria, Virginia, USA.,Department of Biochemistry and Molecular & Cellular Biology, Georgetown University School of Medicine, Washington, District of Columbia, USA
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GLP1 Exerts Paracrine Activity in the Intestinal Lumen of Human Colon. Int J Mol Sci 2022; 23:ijms23073523. [PMID: 35408884 PMCID: PMC8998470 DOI: 10.3390/ijms23073523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 03/18/2022] [Accepted: 03/22/2022] [Indexed: 02/01/2023] Open
Abstract
GLP1 produced in the upper part of the gut is released after food intake and acts by activating insulin secretion, but the role of GLP1 in the colon, where it is predominantly produced, remains unknown. Here we characterized the apical versus basolateral secretion of GLP1 and PYY and the paracrine mechanisms of action of these enterohormones in the human colon. We stimulated human colon tissue in different ex vivo models with meat peptone and we used immunofluorescence to study the presence of canonical and non-canonical receptors of GLP1. We found that PYY and GLP1 are secreted mainly at the gut lumen in unstimulated and stimulated conditions. We detected DPP4 activity and found that GLP1R and GCGR are widely expressed in the human colon epithelium. Unlike GLP1R, GCGR is not expressed in the lamina propria, but it is located in the crypts of Lieberkühn. We detected GLP1R expression in human colon cell culture models. We show that the apical secretion of PYY and GLP1 occurs in humans, and we provide evidence that GLP1 has a potential direct paracrine function through the expression of its receptors in the colon epithelium, opening new therapeutic perspectives in the use of enterohormones analogues in metabolic pathologies.
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26
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Microbiota and Pain: Save Your Gut Feeling. Cells 2022; 11:cells11060971. [PMID: 35326422 PMCID: PMC8946251 DOI: 10.3390/cells11060971] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 02/28/2022] [Accepted: 03/08/2022] [Indexed: 12/04/2022] Open
Abstract
Recently, a growing body of evidence has emerged regarding the interplay between microbiota and the nervous system. This relationship has been associated with several pathological conditions and also with the onset and regulation of pain. Dysregulation of the axis leads to a huge variety of diseases such as visceral hypersensitivity, stress-induced hyperalgesia, allodynia, inflammatory pain and functional disorders. In pain management, probiotics have shown promising results. This narrative review describes the peripheral and central mechanisms underlying pain processing and regulation, highlighting the role of the gut-brain axis in the modulation of pain. We summarized the main findings in regard to the stress impact on microbiota’s composition and its influence on pain perception. We also focused on the relationship between gut microbiota and both visceral and inflammatory pain and we provided a summary of the main evidence regarding the mechanistic effects and probiotics use.
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27
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Panther EJ, Dodd W, Clark A, Lucke-Wold B. Gastrointestinal Microbiome and Neurologic Injury. Biomedicines 2022; 10:biomedicines10020500. [PMID: 35203709 PMCID: PMC8962360 DOI: 10.3390/biomedicines10020500] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 02/16/2022] [Accepted: 02/18/2022] [Indexed: 02/05/2023] Open
Abstract
Communication between the enteric nervous system (ENS) of the gastrointestinal (GI) tract and the central nervous system (CNS) is vital for maintaining systemic homeostasis. Intrinsic and extrinsic neurological inputs of the gut regulate blood flow, peristalsis, hormone release, and immunological function. The health of the gut microbiome plays a vital role in regulating the overall function and well-being of the individual. Microbes release short-chain fatty acids (SCFAs) that regulate G-protein-coupled receptors to mediate hormone release, neurotransmitter release (i.e., serotonin, dopamine, noradrenaline, γ-aminobutyric acid (GABA), acetylcholine, and histamine), and regulate inflammation and mood. Further gaseous factors (i.e., nitric oxide) are important in regulating inflammation and have a response in injury. Neurologic injuries such as ischemic stroke, spinal cord injury, traumatic brain injury, and hemorrhagic cerebrovascular lesions can all lead to gut dysbiosis. Additionally, unfavorable alterations in the composition of the microbiota may be associated with increased risk for these neurologic injuries due to increased proinflammatory molecules and clotting factors. Interventions such as probiotics, fecal microbiota transplantation, and oral SCFAs have been shown to stabilize and improve the composition of the microbiome. However, the effect this has on neurologic injury prevention and recovery has not been studied extensively. The purpose of this review is to elaborate on the complex relationship between the nervous system and the microbiome and to report how neurologic injury modulates the status of the microbiome. Finally, we will propose various interventions that may be beneficial in the recovery from neurologic injury.
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Affiliation(s)
- Eric J. Panther
- Department of Neurosurgery, University of Florida, Gainesville, FL 32601, USA;
- Correspondence:
| | - William Dodd
- College of Medicine, University of Central Florida, Orlando, FL 32816, USA; (W.D.); (A.C.)
| | - Alec Clark
- College of Medicine, University of Central Florida, Orlando, FL 32816, USA; (W.D.); (A.C.)
| | - Brandon Lucke-Wold
- Department of Neurosurgery, University of Florida, Gainesville, FL 32601, USA;
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Hamilton MK, Wall ES, Robinson CD, Guillemin K, Eisen JS. Enteric nervous system modulation of luminal pH modifies the microbial environment to promote intestinal health. PLoS Pathog 2022; 18:e1009989. [PMID: 35143593 PMCID: PMC8830661 DOI: 10.1371/journal.ppat.1009989] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 01/07/2022] [Indexed: 01/02/2023] Open
Abstract
The enteric nervous system (ENS) controls many aspects of intestinal homeostasis, including parameters that shape the habitat of microbial residents. Previously we showed that zebrafish lacking an ENS, due to deficiency of the sox10 gene, develop intestinal inflammation and bacterial dysbiosis, with an expansion of proinflammatory Vibrio strains. To understand the primary defects resulting in dysbiosis in sox10 mutants, we investigated how the ENS shapes the intestinal environment in the absence of microbiota and associated inflammatory responses. We found that intestinal transit, intestinal permeability, and luminal pH regulation are all aberrant in sox10 mutants, independent of microbially induced inflammation. Treatment with the proton pump inhibitor, omeprazole, corrected the more acidic luminal pH of sox10 mutants to wild type levels. Omeprazole treatment also prevented overabundance of Vibrio and ameliorated inflammation in sox10 mutant intestines. Treatment with the carbonic anhydrase inhibitor, acetazolamide, caused wild type luminal pH to become more acidic, and increased both Vibrio abundance and intestinal inflammation. We conclude that a primary function of the ENS is to regulate luminal pH, which plays a critical role in shaping the resident microbial community and regulating intestinal inflammation.
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Affiliation(s)
- M. Kristina Hamilton
- Institute of Neuroscience, University of Oregon, Eugene, Oregon, United States of America
- Institute of Molecular Biology, University of Oregon, Eugene, Oregon, United States of America
| | - Elena S. Wall
- Institute of Molecular Biology, University of Oregon, Eugene, Oregon, United States of America
| | - Catherine D. Robinson
- Institute of Molecular Biology, University of Oregon, Eugene, Oregon, United States of America
| | - Karen Guillemin
- Institute of Molecular Biology, University of Oregon, Eugene, Oregon, United States of America
- Humans and the Microbiome Program, CIFAR, Toronto, Ontario, Canada
- * E-mail: (KG); (JSE)
| | - Judith S. Eisen
- Institute of Neuroscience, University of Oregon, Eugene, Oregon, United States of America
- * E-mail: (KG); (JSE)
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29
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O’Day C, Finkelstein DI, Diwakarla S, McQuade RM. A Critical Analysis of Intestinal Enteric Neuron Loss and Constipation in Parkinson's Disease. JOURNAL OF PARKINSON'S DISEASE 2022; 12:1841-1861. [PMID: 35848035 PMCID: PMC9535602 DOI: 10.3233/jpd-223262] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 06/26/2022] [Indexed: 06/06/2023]
Abstract
Constipation afflicts many patients with Parkinson's disease (PD) and significantly impacts on patient quality of life. PD-related constipation is caused by intestinal dysfunction, but the etiology of this dysfunction in patients is unknown. One possible cause is neuron loss within the enteric nervous system (ENS) of the intestine. This review aims to 1) Critically evaluate the evidence for and against intestinal enteric neuron loss in PD patients, 2) Justify why PD-related constipation must be objectively measured, 3) Explore the potential link between loss of enteric neurons in the intestine and constipation in PD, 4) Provide potential explanations for disparities in the literature, and 5) Outline data and study design considerations to improve future research. Before the connection between intestinal enteric neuron loss and PD-related constipation can be confidently described, future research must use sufficiently large samples representative of the patient population (majority diagnosed with idiopathic PD for at least 5 years), implement a consistent neuronal quantification method and study design, including standardized patient recruitment criteria, objectively quantify intestinal dysfunctions, publish with a high degree of data transparency and account for potential PD heterogeneity. Further investigation into other potential influencers of PD-related constipation is also required, including changes in the function, connectivity, mitochondria and/or α-synuclein proteins of enteric neurons and their extrinsic innervation. The connection between enteric neuron loss and other PD-related gastrointestinal (GI) issues, including gastroparesis and dysphagia, as well as changes in nutrient absorption and the microbiome, should be explored in future research.
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Affiliation(s)
- Chelsea O’Day
- Gut-Axis Injury & Repair Laboratory, Department of Medicine - Western Centre for Health Research and Education (WCHRE), The University of Melbourne, Sunshine Hospital, St Albans, VIC, Australia
- The Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia
- Australian Institute of Musculoskeletal Science (AIMSS), Western Centre for Health Research and Education (WCHRE) Level 3 and 4, Sunshine Hospital, St Albans, VIC, Australia
| | - David Isaac Finkelstein
- Parkinson’s Disease Laboratory, The Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia
| | - Shanti Diwakarla
- Gut-Axis Injury & Repair Laboratory, Department of Medicine - Western Centre for Health Research and Education (WCHRE), The University of Melbourne, Sunshine Hospital, St Albans, VIC, Australia
- The Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia
- Australian Institute of Musculoskeletal Science (AIMSS), Western Centre for Health Research and Education (WCHRE) Level 3 and 4, Sunshine Hospital, St Albans, VIC, Australia
| | - Rachel Mai McQuade
- Gut-Axis Injury & Repair Laboratory, Department of Medicine - Western Centre for Health Research and Education (WCHRE), The University of Melbourne, Sunshine Hospital, St Albans, VIC, Australia
- The Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia
- Australian Institute of Musculoskeletal Science (AIMSS), Western Centre for Health Research and Education (WCHRE) Level 3 and 4, Sunshine Hospital, St Albans, VIC, Australia
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30
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Perez-Medina A, Galligan JJ. Nitrergic and Purinergic Nerves in the Small Intestinal Myenteric Plexus and Circular Muscle of Mice and Guinea Pigs. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1383:33-43. [PMID: 36587144 DOI: 10.1007/978-3-031-05843-1_4] [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
ATP is an excitatory and inhibitory neurotransmitter, while nitric oxide (NO) is an inhibitory neurotransmitter in the enteric nervous system (ENS). We used a vesicular nucleotide transporter (SLC17A9, VNUT) antibody and a nitric oxide synthase (NOS) antibody to identify purinergic and nitrergic nerves in mouse and guinea ileum. Mouse: VNUT-immunoreactivity (ir) was detected in nerve fibers in myenteric ganglia and circular muscle. VNUT-ir fibers surrounded choline acetyltransferase (ChAT), nitric oxide synthase (nNOS), and calretinin-ir neurons. VNUT-ir nerve cell bodies were not detected. Tyrosine hydroxylase (TH)-ir nerves were detected in myenteric ganglia and the tertiary plexus. Guinea pig: VNUT-ir was detected in neurons and nerves fibers and did not overlap with NOS-ir nerve fibers. VNUT-ir was detected in nerve fibers in ganglia but not nerve cell bodies. VNUT-ir nerve fibers surrounded NOS-ir and NOS- neurons. NOS-ir and VNUT-ir nerve fibers did not overlap in myenteric ganglia or circular muscle. VNUT-ir nerves surrounded some ChAT-ir neurons. VNUT-ir and ChAT-ir were detected in separate nerves in the CM. VNUT-ir nerve fibers surrounded calretinin-ir neurons.Conclusions: VNUT-ir neurons likely mediate purinergic signaling in small intestinal myenteric ganglia and circular muscle. ATP and NO are likely released from different inhibitory motorneurons. VNUT-ir and ChAT-ir interneurons mediate cholinergic and purinergic synaptic transmission in the myenteric plexus.
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Affiliation(s)
- Alberto Perez-Medina
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, USA
| | - James J Galligan
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, USA. .,The Neuroscience Program, Michigan State University, East Lansing, MI, USA.
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31
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Spencer NJ, Costa M. Rhythmicity in the Enteric Nervous System of Mice. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1383:295-306. [PMID: 36587167 DOI: 10.1007/978-3-031-05843-1_27] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The enteric nervous system (ENS) is required for many cyclical patterns of motor activity along different regions of the gastrointestinal (GI) tract. What has remained mysterious is precisely how many thousands of neurons within the ENS are temporally activated to generate cyclical neurogenic contractions of GI-smooth muscle layers. This has been an especially puzzling conundrum, since the ENS consists of an extensive network of small ganglia, with each ganglion consisting of a heterogeneous population of neurons, with diverse cell soma morphologies, neurochemical and biophysical characteristics, and neural connectivity. Neuronal imaging studies of the mouse large intestine have provided major new insights into how the different classes of myenteric neurons are activated during cyclical neurogenic motor patterns, such as the colonic motor complex (CMC). It has been revealed that during CMCs (in the isolated mouse whole colon), large populations of myenteric neurons, across large spatial fields, coordinate their firing, via bursts of fast synaptic inputs at ~2 Hz. This coordinated firing of many thousands of myenteric neurons synchronously over many rows of interconnected ganglia occurs irrespective of the functional class of neuron. Aborally directed propulsion of content along the mouse colon is due, in large part, to polarity of the enteric circuits including the projections of the intrinsic excitatory and inhibitory motor neurons but still involves the fundamental ~2 Hz rhythmic activity of specific classes of enteric neurons. What remains to be determined are the mechanisms that initiate and terminate the patterned firing of large ensembles of enteric neurons during cyclic activity. This remains an exciting challenge for future studies.
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Affiliation(s)
- Nick J Spencer
- Visceral Neurophysiology Laboratory, Department of Physiology, College of Medicine and Public Health & Centre for Neuroscience, Flinders University, Bedford Park, SA, Australia.
| | - Marcello Costa
- Visceral Neurophysiology Laboratory, Department of Physiology, College of Medicine and Public Health, Flinders University, Bedford Park, SA, Australia
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32
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Luo S, Zhu H, Zhang J, Wan D. The Pivotal Role of Microbiota in Modulating the Neuronal-Glial-Epithelial Unit. Infect Drug Resist 2021; 14:5613-5628. [PMID: 34992388 PMCID: PMC8711043 DOI: 10.2147/idr.s342782] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Accepted: 11/26/2021] [Indexed: 12/12/2022] Open
Abstract
The enteric nervous system (ENS) consists of enteric neurons and enteric glial cells (EGCs) and controls the function of the epithelial barrier. Thus, a novel concept of neuronal-glial-epithelial unit in the gut was put forward by analogy with neuronal-glial-endothelial unit in the brain. The environment in the gastrointestinal (GI) tract is complex as it harbours millions of bacteria, which extensively attach with intestinal epithelium. The cross-talk between the neuronal-glial-endothelial unit and microbiota plays a pivotal role in modulating the epithelial barrier's permeability, intestinal development and immune response. And evidence shows dysbiosis is the potent risk factor in the pathologic process of Parkinson's disease (PD) and inflammatory bowel disease (IBD). In this review, we summarize the compelling results in favor of microbiota serving as the key modulator in the neuronal-glial-epithelial unit development and function, with profound effects on intestinal homeostasis.
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Affiliation(s)
- Siyu Luo
- Department of Emergency & Critical Care Medicine, The First Affiliated Hospital of Chongqing Medical University, Chongqing, People’s Republic of China
| | - Huifeng Zhu
- College of Pharmaceutical Sciences & Chinese Medicine, Southwest University, Chongqing, People’s Republic of China
| | - Junhui Zhang
- Health Management Center, The First Affiliated Hospital of Chongqing Medical University, Chongqing, People’s Republic of China
| | - Dong Wan
- Department of Emergency & Critical Care Medicine, The First Affiliated Hospital of Chongqing Medical University, Chongqing, People’s Republic of China
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33
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Magalhães HIR, Castelucci P. Enteric nervous system and inflammatory bowel diseases: Correlated impacts and therapeutic approaches through the P2X7 receptor. World J Gastroenterol 2021; 27:7909-7924. [PMID: 35046620 PMCID: PMC8678817 DOI: 10.3748/wjg.v27.i46.7909] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Revised: 08/19/2021] [Accepted: 11/25/2021] [Indexed: 02/06/2023] Open
Abstract
The enteric nervous system (ENS) consists of thousands of small ganglia arranged in the submucosal and myenteric plexuses, which can be negatively affected by Crohn's disease and ulcerative colitis - inflammatory bowel diseases (IBDs). IBDs are complex and multifactorial disorders characterized by chronic and recurrent inflammation of the intestine, and the symptoms of IBDs may include abdominal pain, diarrhea, rectal bleeding, and weight loss. The P2X7 receptor has become a promising therapeutic target for IBDs, especially owing to its wide expression and, in the case of other purinergic receptors, in both human and model animal enteric cells. However, little is known about the actual involvement between the activation of the P2X7 receptor and the cascade of subsequent events and how all these activities associated with chemical signals interfere with the functionality of the affected or treated intestine. In this review, an integrated view is provided, correlating the structural organization of the ENS and the effects of IBDs, focusing on cellular constituents and how therapeutic approaches through the P2X7 receptor can assist in both protection from damage and tissue preservation.
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Affiliation(s)
| | - Patricia Castelucci
- Department of Anatomy, Institute of Biomedical Sciences, University of São Paulo, São Paulo 08000-000, Brazil
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Ahmed MA, Venugopal S, Jung R. Engaging biological oscillators through second messenger pathways permits emergence of a robust gastric slow-wave during peristalsis. PLoS Comput Biol 2021; 17:e1009644. [PMID: 34871315 PMCID: PMC8675931 DOI: 10.1371/journal.pcbi.1009644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Revised: 12/16/2021] [Accepted: 11/15/2021] [Indexed: 11/19/2022] Open
Abstract
Peristalsis, the coordinated contraction—relaxation of the muscles of the stomach is important for normal gastric motility and is impaired in motility disorders. Coordinated electrical depolarizations that originate and propagate within a network of interconnected layers of interstitial cells of Cajal (ICC) and smooth muscle (SM) cells of the stomach wall as a slow-wave, underly peristalsis. Normally, the gastric slow-wave oscillates with a single period and uniform rostrocaudal lag, exhibiting network entrainment. Understanding of the integrative role of neurotransmission and intercellular coupling in the propagation of an entrained gastric slow-wave, important for understanding motility disorders, however, remains incomplete. Using a computational framework constituted of a novel gastric motility network (GMN) model we address the hypothesis that engaging biological oscillators (i.e., ICCs) by constitutive gap junction coupling mechanisms and enteric neural innervation activated signals can confer a robust entrained gastric slow-wave. We demonstrate that while a decreasing enteric neural innervation gradient that modulates the intracellular IP3 concentration in the ICCs can guide the aboral slow-wave propagation essential for peristalsis, engaging ICCs by recruiting the exchange of second messengers (inositol trisphosphate (IP3) and Ca2+) ensures a robust entrained longitudinal slow-wave, even in the presence of biological variability in electrical coupling strengths. Our GMN with the distinct intercellular coupling in conjunction with the intracellular feedback pathways and a rostrocaudal enteric neural innervation gradient allows gastric slow waves to oscillate with a moderate range of frequencies and to propagate with a broad range of velocities, thus preventing decoupling observed in motility disorders. Overall, the findings provide a mechanistic explanation for the emergence of decoupled slow waves associated with motility impairments of the stomach, offer directions for future experiments and theoretical work, and can potentially aid in the design of new interventional pharmacological and neuromodulation device treatments for addressing gastric motility disorders. The coordinated contraction and relaxation of the muscles of the stomach, known as peristalsis is important for normal gastric motility and primarily governed by electrical depolarizations that originate and propagate within a network of interconnected layers of interstitial cells of Cajal (ICCs) and smooth muscle cells of the stomach wall as a slow-wave. Under normal conditions, a gastric slow-wave oscillates with a single period and uniform rostrocaudal lag, exhibiting network entrainment. However, the understanding of intrinsic and extrinsic mechanisms that ensure propagation of a robust entrained slow-wave remains incomplete. Here, using a computational framework, we show that in conjunction with an enteric neural innervation gradient along the rostrocaudal ICC chain, and intercellular electrical coupling, the intercellular exchange of inositol trisphosphate between ICCs prevents decoupling by extending the longitudinal entrainment range along the stomach wall, even when variability in intercellular coupling exists. The findings from our study indicate ways that ensure the rostrocaudal spread of a robust gastric slow-wave and provide a mechanistic explanation for the emergence of decoupled slow waves associated with motility impairments of the stomach.
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Affiliation(s)
- Md Ashfaq Ahmed
- Department of Biomedical Engineering, Florida International University, Miami, Florida, United States of America
| | - Sharmila Venugopal
- Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, California, United States of America
- * E-mail: (SV); (RJ)
| | - Ranu Jung
- Department of Biomedical Engineering, Florida International University, Miami, Florida, United States of America
- * E-mail: (SV); (RJ)
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35
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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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Pustovit RV, Zhang X, Liew JJ, Praveen P, Liu M, Koo A, Oparija-Rogenmozere L, Ou Q, Kocan M, Nie S, Bathgate RA, Furness JB, Hossain MA. A Novel Antagonist Peptide Reveals a Physiological Role of Insulin-Like Peptide 5 in Control of Colorectal Function. ACS Pharmacol Transl Sci 2021; 4:1665-1674. [PMID: 34661082 DOI: 10.1021/acsptsci.1c00171] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Indexed: 12/23/2022]
Abstract
Insulin-like peptide 5 (INSL5), the natural ligand for the relaxin family peptide receptor 4 (RXFP4), is a gut hormone that is exclusively produced by colonic L-cells. We have recently developed an analogue of INSL5, INSL5-A13, that acts as an RXFP4 agonist in vitro and stimulates colorectal propulsion in wild-type mice but not in RXFP4-knockout mice. These results suggest that INSL5 may have a physiological role in the control of colorectal motility. To investigate this possibility, in this study we designed and developed a novel INSL5 analogue, INSL5-A13NR. This compound is a potent antagonist, without significant agonist activity, in two in vitro assays. We report here for the first time that this novel antagonist peptide blocks agonist-induced increase in colon motility in mice that express RXFP4. Our data also show that colorectal propulsion induced by intracolonic administration of bacterial products (short-chain fatty acids, SCFAs) is antagonized by INSL5-A13NR. Therefore, INSL5-A13NR is an important research tool and potential drug lead for the treatment of colon motility disorders, such as bacterial diarrheas.
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Affiliation(s)
- Ruslan V Pustovit
- The Florey Institute of Neuroscience and Mental Health; Department of Anatomy and Physiology; School of Biosciences, Melbourne Mass Spectrometry and Proteomics Facility, Bio21 Institute; Department of Biochemistry and Pharmacology; School of Chemistry; The University of Melbourne, Parkville, Victoria 3052, Australia
| | - Xiaozhou Zhang
- The Florey Institute of Neuroscience and Mental Health; Department of Anatomy and Physiology; School of Biosciences, Melbourne Mass Spectrometry and Proteomics Facility, Bio21 Institute; Department of Biochemistry and Pharmacology; School of Chemistry; The University of Melbourne, Parkville, Victoria 3052, Australia
| | - Jamie Jm Liew
- The Florey Institute of Neuroscience and Mental Health; Department of Anatomy and Physiology; School of Biosciences, Melbourne Mass Spectrometry and Proteomics Facility, Bio21 Institute; Department of Biochemistry and Pharmacology; School of Chemistry; The University of Melbourne, Parkville, Victoria 3052, Australia
| | - Praveen Praveen
- The Florey Institute of Neuroscience and Mental Health; Department of Anatomy and Physiology; School of Biosciences, Melbourne Mass Spectrometry and Proteomics Facility, Bio21 Institute; Department of Biochemistry and Pharmacology; School of Chemistry; The University of Melbourne, Parkville, Victoria 3052, Australia
| | - Mengjie Liu
- The Florey Institute of Neuroscience and Mental Health; Department of Anatomy and Physiology; School of Biosciences, Melbourne Mass Spectrometry and Proteomics Facility, Bio21 Institute; Department of Biochemistry and Pharmacology; School of Chemistry; The University of Melbourne, Parkville, Victoria 3052, Australia
| | - Ada Koo
- The Florey Institute of Neuroscience and Mental Health; Department of Anatomy and Physiology; School of Biosciences, Melbourne Mass Spectrometry and Proteomics Facility, Bio21 Institute; Department of Biochemistry and Pharmacology; School of Chemistry; The University of Melbourne, Parkville, Victoria 3052, Australia
| | - Lalita Oparija-Rogenmozere
- The Florey Institute of Neuroscience and Mental Health; Department of Anatomy and Physiology; School of Biosciences, Melbourne Mass Spectrometry and Proteomics Facility, Bio21 Institute; Department of Biochemistry and Pharmacology; School of Chemistry; The University of Melbourne, Parkville, Victoria 3052, Australia
| | - Qinghao Ou
- The Florey Institute of Neuroscience and Mental Health; Department of Anatomy and Physiology; School of Biosciences, Melbourne Mass Spectrometry and Proteomics Facility, Bio21 Institute; Department of Biochemistry and Pharmacology; School of Chemistry; The University of Melbourne, Parkville, Victoria 3052, Australia
| | - Martina Kocan
- The Florey Institute of Neuroscience and Mental Health; Department of Anatomy and Physiology; School of Biosciences, Melbourne Mass Spectrometry and Proteomics Facility, Bio21 Institute; Department of Biochemistry and Pharmacology; School of Chemistry; The University of Melbourne, Parkville, Victoria 3052, Australia
| | - Shuai Nie
- The Florey Institute of Neuroscience and Mental Health; Department of Anatomy and Physiology; School of Biosciences, Melbourne Mass Spectrometry and Proteomics Facility, Bio21 Institute; Department of Biochemistry and Pharmacology; School of Chemistry; The University of Melbourne, Parkville, Victoria 3052, Australia
| | - Ross Ad Bathgate
- The Florey Institute of Neuroscience and Mental Health; Department of Anatomy and Physiology; School of Biosciences, Melbourne Mass Spectrometry and Proteomics Facility, Bio21 Institute; Department of Biochemistry and Pharmacology; School of Chemistry; The University of Melbourne, Parkville, Victoria 3052, Australia
| | - John B Furness
- The Florey Institute of Neuroscience and Mental Health; Department of Anatomy and Physiology; School of Biosciences, Melbourne Mass Spectrometry and Proteomics Facility, Bio21 Institute; Department of Biochemistry and Pharmacology; School of Chemistry; The University of Melbourne, Parkville, Victoria 3052, Australia
| | - Mohammed Akhter Hossain
- The Florey Institute of Neuroscience and Mental Health; Department of Anatomy and Physiology; School of Biosciences, Melbourne Mass Spectrometry and Proteomics Facility, Bio21 Institute; Department of Biochemistry and Pharmacology; School of Chemistry; The University of Melbourne, Parkville, Victoria 3052, Australia
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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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Gershon MD, Margolis KG. The gut, its microbiome, and the brain: connections and communications. J Clin Invest 2021; 131:143768. [PMID: 34523615 PMCID: PMC8439601 DOI: 10.1172/jci143768] [Citation(s) in RCA: 68] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Modern research on gastrointestinal behavior has revealed it to be a highly complex bidirectional process in which the gut sends signals to the brain, via spinal and vagal visceral afferent pathways, and receives sympathetic and parasympathetic inputs. Concomitantly, the enteric nervous system within the bowel, which contains intrinsic primary afferent neurons, interneurons, and motor neurons, also senses the enteric environment and controls the detailed patterns of intestinal motility and secretion. The vast microbiome that is resident within the enteric lumen is yet another contributor, not only to gut behavior, but to the bidirectional signaling process, so that the existence of a microbiota-gut-brain "connectome" has become apparent. The interaction between the microbiota, the bowel, and the brain now appears to be neither a top-down nor a bottom-up process. Instead, it is an ongoing, tripartite conversation, the outline of which is beginning to emerge and is the subject of this Review. We emphasize aspects of the exponentially increasing knowledge of the microbiota-gut-brain "connectome" and focus attention on the roles that serotonin, Toll-like receptors, and macrophages play in signaling as exemplars of potentially generalizable mechanisms.
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Affiliation(s)
| | - Kara Gross Margolis
- Department of Pediatrics, Columbia University Vagelos College of Physicians and Surgeons, New York, New York, USA
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Spencer NJ, Travis L, Wiklendt L, Costa M, Hibberd TJ, Brookes SJ, Dinning P, Hu H, Wattchow DA, Sorensen J. Long range synchronization within the enteric nervous system underlies propulsion along the large intestine in mice. Commun Biol 2021; 4:955. [PMID: 34376798 PMCID: PMC8355373 DOI: 10.1038/s42003-021-02485-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 07/15/2021] [Indexed: 02/07/2023] Open
Abstract
How the Enteric Nervous System (ENS) coordinates propulsion of content along the gastrointestinal (GI)-tract has been a major unresolved issue. We reveal a mechanism that explains how ENS activity underlies propulsion of content along the colon. We used a recently developed high-resolution video imaging approach with concurrent electrophysiological recordings from smooth muscle, during fluid propulsion. Recordings showed pulsatile firing of excitatory and inhibitory neuromuscular inputs not only in proximal colon, but also distal colon, long before the propagating contraction invades the distal region. During propulsion, wavelet analysis revealed increased coherence at ~2 Hz over large distances between the proximal and distal regions. Therefore, during propulsion, synchronous firing of descending inhibitory nerve pathways over long ranges aborally acts to suppress smooth muscle from contracting, counteracting the excitatory nerve pathways over this same region of colon. This delays muscle contraction downstream, ahead of the advancing contraction. The mechanism identified is more complex than expected and vastly different from fluid propulsion along other hollow smooth muscle organs; like lymphatic vessels, portal vein, or ureters, that evolved without intrinsic neurons.
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Affiliation(s)
- Nick J Spencer
- Visceral Neurophysiology Laboratory, College of Medicine and Public Health, Centre for Neuroscience, Flinders University, Bedford Park, SA, Australia.
| | - Lee Travis
- Visceral Neurophysiology Laboratory, College of Medicine and Public Health, Centre for Neuroscience, Flinders University, Bedford Park, SA, Australia
| | - Lukasz Wiklendt
- Discipline of Gastroenterology, College of Medicine and Public Health, Flinders Medical Centre, Bedford Park, SA, Australia
| | - Marcello Costa
- Visceral Neurophysiology Laboratory, College of Medicine and Public Health, Centre for Neuroscience, Flinders University, Bedford Park, SA, Australia
| | - Timothy J Hibberd
- Visceral Neurophysiology Laboratory, College of Medicine and Public Health, Centre for Neuroscience, Flinders University, Bedford Park, SA, Australia
| | - Simon J Brookes
- Visceral Neurophysiology Laboratory, College of Medicine and Public Health, Centre for Neuroscience, Flinders University, Bedford Park, SA, Australia
| | - Phil Dinning
- Discipline of Gastroenterology, College of Medicine and Public Health, Flinders Medical Centre, Bedford Park, SA, Australia
| | - Hongzhen Hu
- Department of Anesthesiology, The Center for the Study of Itch, Washington University, St Louis, MO, USA
| | - David A Wattchow
- Discipline of Surgery, College of Medicine and Public Health, Flinders Medical Centre, Bedford Park, SA, Australia
| | - Julian Sorensen
- Visceral Neurophysiology Laboratory, College of Medicine and Public Health, Centre for Neuroscience, Flinders University, Bedford Park, SA, Australia
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Li ZS, Hung LY, Margolis KG, Ambron RT, Sung YJ, Gershon MD. The α isoform of cGMP-dependent protein kinase 1 (PKG1α) is expressed and functionally important in intrinsic primary afferent neurons of the guinea pig enteric nervous system. Neurogastroenterol Motil 2021; 33:e14100. [PMID: 33655600 PMCID: PMC8681866 DOI: 10.1111/nmo.14100] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Revised: 01/18/2021] [Accepted: 01/26/2021] [Indexed: 12/15/2022]
Abstract
BACKGROUND Intrinsic primary afferent neurons (IPANs) enable the gut to manifest reflexes in the absence of CNS input. PKG1α is selectively expressed in a subset of neurons in dorsal root ganglia (DRG) and has been linked to nociception and long-term hyperexcitability. METHODS We used immunoblotting, immunocytochemistry, and in vitro assays of IPAN-dependent enteric functions to test hypotheses that subsets of primary neurons of the ENS and DRG share a reliance on PKG1α expression. KEY RESULTS PKG1α immunoreactivity was demonstrated in immunoblots from isolated myenteric ganglia. PKG1α, but not PKG1β, immunoreactivity, was coincident with that of neuronal markers (HuC/D; β3-tubulin) in both enteric plexuses. PKG1α immunoreactivity also co-localized with the immunoreactivities of the IPAN markers, calbindin (100%; myenteric plexus) and cytoplasmic NeuN (98 ± 1% submucosal plexus). CGRP-immunoreactive DRG neurons, identified as visceral afferents by retrograde transport, were PKG1α-immunoreactive. We used intraluminal cholera toxin to determine whether PKG1α was necessary to enable stimulation of the mucosa to activate Fos in enteric neurons. Tetrodotoxin (1.0 µM), low Ca2+ /high Mg2+ media, and the PKG inhibitor, N46 (100 µM), all inhibited Fos activation in myenteric neurons. N46 also concentration dependently inhibited peristaltic reflexes in isolated preparations of distal colon (IC50 = 83.3 ± 1.3 µM). CONCLUSIONS & INFERENCES These data suggest that PKG1α is present and functionally important in IPANs and visceral afferent nociceptive neurons.
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Affiliation(s)
- Zhi S. Li
- Departments of Pathology & Cell Biology, Columbia University, New York, NY, USA
| | - Lin Y. Hung
- Departments of Pediatrics, Columbia University, New York, NY, USA
| | - Kara G. Margolis
- Departments of Pediatrics, Columbia University, New York, NY, USA
| | - Richard T. Ambron
- Departments of Pathology & Cell Biology, Columbia University, New York, NY, USA
| | - Ying J. Sung
- Departments of Basic Science, The Commonwealth Medical College, Scranton, PA, USA
| | - Michael D. Gershon
- Departments of Pathology & Cell Biology, Columbia University, New York, NY, USA
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Wang L, Challis C, Li S, Fowlkes CC, Kumar SR, Yuan PQ, Taché YF. Multicolor sparse viral labeling and 3D digital tracing of enteric plexus in mouse proximal colon using a novel adeno-associated virus capsid. Neurogastroenterol Motil 2021; 33:e14014. [PMID: 33094876 PMCID: PMC8568587 DOI: 10.1111/nmo.14014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 08/15/2020] [Accepted: 09/22/2020] [Indexed: 02/08/2023]
Abstract
BACKGROUND Intravenous administration of adeno-associated virus (AAV) can be used as a noninvasive approach to trace neuronal morphology and links. AAV-PHP.S is a variant of AAV9 that effectively transduces the peripheral nervous system. The objective was to label randomly and sparsely enteric plexus in the mouse colon using AAV-PHP.S with a tunable two-component multicolor vector system and digitally trace individual neurons and nerve fibers within microcircuits in three dimensions (3D). METHODS A vector system including a tetracycline inducer with a tet-responsive element driving three separate fluorophores was packaged in the AAV-PHP.S capsid. The vectors were injected retro-orbitally in mice, and the colon was harvested 3 weeks after. Confocal microscopic images of enteric plexus were digitally segmented and traced in 3D using Neurolucida 360, neuTube, or Imaris software. KEY RESULTS The transduction of multicolor AAV vectors induced random sparse spectral labeling of soma and neurites primarily in the myenteric plexus of the proximal colon, while neurons in the submucosal plexus were occasionally transduced. Digital tracing in 3D showed various types of wiring, including multiple conjunctions of one neuron with other neurons, neurites en route, and endings; clusters of neurons in close apposition between each other; axon-axon parallel conjunctions; and intraganglionic nerve endings consisting of multiple nerve endings and passing fibers. Most of digitally traced neuronal somas were of small or medium in size. CONCLUSIONS & INFERENCES The multicolor AAV-PHP.S-packaged vectors enabled random sparse spectral labeling and revealed complexities of enteric microcircuit in the mouse proximal colon. The techniques can facilitate digital modeling of enteric micro-circuitry.
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Affiliation(s)
- Lixin Wang
- Department of Medicine, Taman Manoukisan Digestive Diseases Division, UCLA, Los Angeles, CA, USA,Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA, USA
| | - Collin Challis
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Songlin Li
- Department of Medicine, Taman Manoukisan Digestive Diseases Division, UCLA, Los Angeles, CA, USA
| | | | - Sripriya Ravindra Kumar
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Pu-Qing Yuan
- Department of Medicine, Taman Manoukisan Digestive Diseases Division, UCLA, Los Angeles, CA, USA
| | - Yvette F. Taché
- Department of Medicine, Taman Manoukisan Digestive Diseases Division, UCLA, Los Angeles, CA, USA,Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA, USA
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Interactions between the microbiota and enteric nervous system during gut-brain disorders. Neuropharmacology 2021; 197:108721. [PMID: 34274348 DOI: 10.1016/j.neuropharm.2021.108721] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 07/13/2021] [Accepted: 07/13/2021] [Indexed: 02/08/2023]
Abstract
For the last 20 years, researchers have focused their intention on the impact of gut microbiota in healthy and pathological conditions. This year (2021), more than 25,000 articles can be retrieved from PubMed with the keywords "gut microbiota and physiology", showing the constant progress and impact of gut microbes in scientific life. As a result, numerous therapeutic perspectives have been proposed to modulate the gut microbiota composition and/or bioactive factors released from microbes to restore our body functions. Currently, the gut is considered a primary site for the development of pathologies that modify brain functions such as neurodegenerative (Parkinson's, Alzheimer's, etc.) and metabolic (type 2 diabetes, obesity, etc.) disorders. Deciphering the mode of interaction between microbiota and the brain is a real original option to prevent (and maybe treat in the future) the establishment of gut-brain pathologies. The objective of this review is to describe recent scientific elements that explore the communication between gut microbiota and the brain by focusing our interest on the enteric nervous system (ENS) as an intermediate partner. The ENS, which is known as the "second brain", could be under the direct or indirect influence of the gut microbiota and its released factors (short-chain fatty acids, neurotransmitters, gaseous factors, etc.). Thus, in addition to their actions on tissue (adipose tissue, liver, brain, etc.), microbes can have an impact on local ENS activity. This potential modification of ENS function has global repercussions in the whole body via the gut-brain axis and represents a new therapeutic strategy.
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Jakob MO, Kofoed-Branzk M, Deshpande D, Murugan S, Klose CSN. An Integrated View on Neuronal Subsets in the Peripheral Nervous System and Their Role in Immunoregulation. Front Immunol 2021; 12:679055. [PMID: 34322118 PMCID: PMC8312561 DOI: 10.3389/fimmu.2021.679055] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 06/15/2021] [Indexed: 12/21/2022] Open
Abstract
The peripheral nervous system consists of sensory circuits that respond to external and internal stimuli and effector circuits that adapt physiologic functions to environmental challenges. Identifying neurotransmitters and neuropeptides and the corresponding receptors on immune cells implies an essential role for the nervous system in regulating immune reactions. Vice versa, neurons express functional cytokine receptors to respond to inflammatory signals directly. Recent advances in single-cell and single-nuclei sequencing have provided an unprecedented depth in neuronal analysis and allowed to refine the classification of distinct neuronal subsets of the peripheral nervous system. Delineating the sensory and immunoregulatory capacity of different neuronal subsets could inform a better understanding of the response happening in tissues that coordinate physiologic functions, tissue homeostasis and immunity. Here, we summarize current subsets of peripheral neurons and discuss neuronal regulation of immune responses, focusing on neuro-immune interactions in the gastrointestinal tract. The nervous system as a central coordinator of immune reactions and tissue homeostasis may predispose for novel promising therapeutic approaches for a large variety of diseases including but not limited to chronic inflammation.
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Affiliation(s)
- Manuel O Jakob
- Department of Microbiology, Infectious Diseases and Immunology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Michael Kofoed-Branzk
- Department of Microbiology, Infectious Diseases and Immunology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Divija Deshpande
- Department of Microbiology, Infectious Diseases and Immunology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Shaira Murugan
- Department of BioMedical Research, Group of Visceral Surgery and Medicine, University of Bern, Bern, Switzerland
| | - Christoph S N Klose
- Department of Microbiology, Infectious Diseases and Immunology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
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Nitrergic and Substance P Immunoreactive Neurons in the Enteric Nervous System of the Bottlenose Dolphin ( Tursiops truncatus) Intestine. Animals (Basel) 2021; 11:ani11041057. [PMID: 33918065 PMCID: PMC8069003 DOI: 10.3390/ani11041057] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 04/04/2021] [Accepted: 04/05/2021] [Indexed: 12/11/2022] Open
Abstract
Simple Summary The gastrointestinal tract of the bottlenose dolphin (Tursiops truncatus) differs structurally and functionally from that of terrestrial mammals. In particular, the intestine does not show any macroscopic subdivision and lacks a caecum. In addition, the histological aspect of the intestine is relatively constant, without marked differences between the anterior and posterior parts. Although the intestine of these cetaceans presents differences in comparison with terrestrial mammals, little information is currently available on their enteric nervous system. The aim of the present study was to investigate the morphological and quantitative aspects of neurons immunoreactive (IR) for the neuronal nitric oxide synthase (nNOS) and Substance P (SP) in the intestine of bottlenose dolphins (Tursiops truncatus). In these dolphin specimens, a smaller number of nNOS-IR neurons in the submucosal plexus and a larger number of SP-IR neurons in the myenteric plexus were observed compared to other mammals. Interestingly, no co-localization between nNOS- and SP-IR neurons was detected in either of the plexuses, suggesting the existence of two completely distinct functional classes of neurons in the intestine of the bottlenose dolphin. Abstract Compared with other mammals, the digestive system of cetaceans presents some remarkable anatomical and physiological differences. However, the neurochemical features of the enteric nervous system (ENS) in these animals have only been described in part. The present study gives a description of the nitrergic and selected peptidergic systems in the myenteric plexus (MP) and submucosal plexus (SMP) of the intestine of the bottlenose dolphin (Tursiops truncatus). The distribution and morphology of neurons immunoreactive (IR) for the neuronal nitric oxide synthase (nNOS) and Substance P (SP) were immunohistochemically studied in formalin-fixed specimens from the healthy intestine of three animals, and the data were compared with those described in the literature on other mammals (human and non-human). In bottlenose dolphins, the percentages of nitrergic neurons (expressed as median and interquartile range—IQR) were 28% (IQR = 19–29) in the MP and 1% (IQR = 0–2) in the SMP, while the percentages of SP-IR neurons were 31% (IQR = 22–37) in the MP and 41% (IQR = 24–63) in the SMP. Although morphological features of nNOS- and SP-IR neurons were similar to those reported in other mammals, we found some noticeable differences in the percentages of enteric neurons. In fact, we detected a lower proportion of nNOS-IR neurons in the SMP and a higher proportion of SP-IR neurons in the MP compared to other mammals. To the best of the authors’ knowledge, this study represents the first description and quantification of nNOS-IR neurons and the first quantification of SP-IR neurons in the intestine of a cetacean species. As nNOS and SP are important mediators of intestinal functions and the nitrergic population is an important target for many neuroenteropathies, data obtained from a healthy intestine provide a necessary basis to further investigate and understand possible functional differences and motor intestinal dysfunctions/alterations in these special mammals.
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Maiuolo J, Gliozzi M, Musolino V, Carresi C, Scarano F, Nucera S, Scicchitano M, Oppedisano F, Bosco F, Ruga S, Zito MC, Macri R, Palma E, Muscoli C, Mollace V. The Contribution of Gut Microbiota-Brain Axis in the Development of Brain Disorders. Front Neurosci 2021; 15:616883. [PMID: 33833660 PMCID: PMC8021727 DOI: 10.3389/fnins.2021.616883] [Citation(s) in RCA: 54] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Accepted: 02/05/2021] [Indexed: 12/19/2022] Open
Abstract
Different bacterial families colonize most mucosal tissues in the human organism such as the skin, mouth, vagina, respiratory, and gastrointestinal districts. In particular, the mammalian intestine hosts a microbial community of between 1,000 and 1,500 bacterial species, collectively called "microbiota." Co-metabolism between the microbiota and the host system is generated and the symbiotic relationship is mutually beneficial. The balance that is achieved between the microbiota and the host organism is fundamental to the organization of the immune system. Scientific studies have highlighted a direct correlation between the intestinal microbiota and the brain, establishing the existence of the gut microbiota-brain axis. Based on this theory, the microbiota acts on the development, physiology, and cognitive functions of the brain, although the mechanisms involved have not yet been fully interpreted. Similarly, a close relationship between alteration of the intestinal microbiota and the onset of several neurological pathologies has been highlighted. This review aims to point out current knowledge as can be found in literature regarding the connection between intestinal dysbiosis and the onset of particular neurological pathologies such as anxiety and depression, autism spectrum disorder, and multiple sclerosis. These disorders have always been considered to be a consequence of neuronal alteration, but in this review, we hypothesize that these alterations may be non-neuronal in origin, and consider the idea that the composition of the microbiota could be directly involved. In this direction, the following two key points will be highlighted: (1) the direct cross-talk that comes about between neurons and gut microbiota, and (2) the degree of impact of the microbiota on the brain. Could we consider the microbiota a valuable target for reducing or modulating the incidence of certain neurological diseases?
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Affiliation(s)
- Jessica Maiuolo
- IRC-FSH Department of Health Sciences, University “Magna Græcia” of Catanzaro, Catanzaro, Italy
| | - Micaela Gliozzi
- IRC-FSH Department of Health Sciences, University “Magna Græcia” of Catanzaro, Catanzaro, Italy
| | - Vincenzo Musolino
- IRC-FSH Department of Health Sciences, University “Magna Græcia” of Catanzaro, Catanzaro, Italy
| | - Cristina Carresi
- IRC-FSH Department of Health Sciences, University “Magna Græcia” of Catanzaro, Catanzaro, Italy
| | - Federica Scarano
- IRC-FSH Department of Health Sciences, University “Magna Græcia” of Catanzaro, Catanzaro, Italy
| | - Saverio Nucera
- IRC-FSH Department of Health Sciences, University “Magna Græcia” of Catanzaro, Catanzaro, Italy
| | - Miriam Scicchitano
- IRC-FSH Department of Health Sciences, University “Magna Græcia” of Catanzaro, Catanzaro, Italy
| | - Francesca Oppedisano
- IRC-FSH Department of Health Sciences, University “Magna Græcia” of Catanzaro, Catanzaro, Italy
| | - Francesca Bosco
- IRC-FSH Department of Health Sciences, University “Magna Græcia” of Catanzaro, Catanzaro, Italy
| | - Stefano Ruga
- IRC-FSH Department of Health Sciences, University “Magna Græcia” of Catanzaro, Catanzaro, Italy
| | - Maria Caterina Zito
- IRC-FSH Department of Health Sciences, University “Magna Græcia” of Catanzaro, Catanzaro, Italy
| | - Roberta Macri
- IRC-FSH Department of Health Sciences, University “Magna Græcia” of Catanzaro, Catanzaro, Italy
| | - Ernesto Palma
- IRC-FSH Department of Health Sciences, University “Magna Græcia” of Catanzaro, Catanzaro, Italy
| | - Carolina Muscoli
- IRC-FSH Department of Health Sciences, University “Magna Græcia” of Catanzaro, Catanzaro, Italy
- IRCCS San Raffaele, Rome, Italy
| | - Vincenzo Mollace
- IRC-FSH Department of Health Sciences, University “Magna Græcia” of Catanzaro, Catanzaro, Italy
- IRCCS San Raffaele, Rome, Italy
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46
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Howard AGA, Baker PA, Ibarra-García-Padilla R, Moore JA, Rivas LJ, Tallman JJ, Singleton EW, Westheimer JL, Corteguera JA, Uribe RA. An atlas of neural crest lineages along the posterior developing zebrafish at single-cell resolution. eLife 2021; 10:e60005. [PMID: 33591267 PMCID: PMC7886338 DOI: 10.7554/elife.60005] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Accepted: 01/31/2021] [Indexed: 02/06/2023] Open
Abstract
Neural crest cells (NCCs) are vertebrate stem cells that give rise to various cell types throughout the developing body in early life. Here, we utilized single-cell transcriptomic analyses to delineate NCC-derivatives along the posterior developing vertebrate, zebrafish, during the late embryonic to early larval stage, a period when NCCs are actively differentiating into distinct cellular lineages. We identified several major NCC/NCC-derived cell-types including mesenchyme, neural crest, neural, neuronal, glial, and pigment, from which we resolved over three dozen cellular subtypes. We dissected gene expression signatures of pigment progenitors delineating into chromatophore lineages, mesenchyme cells, and enteric NCCs transforming into enteric neurons. Global analysis of NCC derivatives revealed they were demarcated by combinatorial hox gene codes, with distinct profiles within neuronal cells. From these analyses, we present a comprehensive cell-type atlas that can be utilized as a valuable resource for further mechanistic and evolutionary investigations of NCC differentiation.
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Affiliation(s)
| | - Phillip A Baker
- Department of BioSciences, Rice UniversityHoustonUnited States
| | | | - Joshua A Moore
- Department of BioSciences, Rice UniversityHoustonUnited States
| | - Lucia J Rivas
- Department of BioSciences, Rice UniversityHoustonUnited States
| | - James J Tallman
- Department of BioSciences, Rice UniversityHoustonUnited States
| | | | | | | | - Rosa A Uribe
- Department of BioSciences, Rice UniversityHoustonUnited States
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47
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Banfi D, Moro E, Bosi A, Bistoletti M, Cerantola S, Crema F, Maggi F, Giron MC, Giaroni C, Baj A. Impact of Microbial Metabolites on Microbiota-Gut-Brain Axis in Inflammatory Bowel Disease. Int J Mol Sci 2021; 22:1623. [PMID: 33562721 PMCID: PMC7915037 DOI: 10.3390/ijms22041623] [Citation(s) in RCA: 56] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 01/29/2021] [Accepted: 02/02/2021] [Indexed: 02/07/2023] Open
Abstract
The complex bidirectional communication system existing between the gastrointestinal tract and the brain initially termed the "gut-brain axis" and renamed the "microbiota-gut-brain axis", considering the pivotal role of gut microbiota in sustaining local and systemic homeostasis, has a fundamental role in the pathogenesis of Inflammatory Bowel Disease (IBD). The integration of signals deriving from the host neuronal, immune, and endocrine systems with signals deriving from the microbiota may influence the development of the local inflammatory injury and impacts also more distal brain regions, underlying the psychophysiological vulnerability of IBD patients. Mood disorders and increased response to stress are frequently associated with IBD and may affect the disease recurrence and severity, thus requiring an appropriate therapeutic approach in addition to conventional anti-inflammatory treatments. This review highlights the more recent evidence suggesting that alterations of the microbiota-gut-brain bidirectional communication axis may concur to IBD pathogenesis and sustain the development of both local and CNS symptoms. The participation of the main microbial-derived metabolites, also defined as "postbiotics", such as bile acids, short-chain fatty acids, and tryptophan metabolites in the development of IBD-associated gut and brain dysfunction will be discussed. The last section covers a critical evaluation of the main clinical evidence pointing to the microbiome-based therapeutic approaches for the treatment of IBD-related gastrointestinal and neuropsychiatric symptoms.
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Affiliation(s)
- Davide Banfi
- Department of Medicine and Surgery, University of Insubria, via H Dunant 5, 21100 Varese, Italy; (D.B.); (A.B.); (M.B.); (F.M.); (A.B.)
| | - Elisabetta Moro
- Department of Internal Medicine and Therapeutics, Section of Pharmacology, University of Pavia, via Ferrata 9, 27100 Pavia, Italy; (E.M.); (F.C.)
| | - Annalisa Bosi
- Department of Medicine and Surgery, University of Insubria, via H Dunant 5, 21100 Varese, Italy; (D.B.); (A.B.); (M.B.); (F.M.); (A.B.)
| | - Michela Bistoletti
- Department of Medicine and Surgery, University of Insubria, via H Dunant 5, 21100 Varese, Italy; (D.B.); (A.B.); (M.B.); (F.M.); (A.B.)
| | - Silvia Cerantola
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Largo Meneghetti 2, 35131 Padova, Italy; (S.C.); (M.C.G.)
| | - Francesca Crema
- Department of Internal Medicine and Therapeutics, Section of Pharmacology, University of Pavia, via Ferrata 9, 27100 Pavia, Italy; (E.M.); (F.C.)
| | - Fabrizio Maggi
- Department of Medicine and Surgery, University of Insubria, via H Dunant 5, 21100 Varese, Italy; (D.B.); (A.B.); (M.B.); (F.M.); (A.B.)
| | - Maria Cecilia Giron
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Largo Meneghetti 2, 35131 Padova, Italy; (S.C.); (M.C.G.)
| | - Cristina Giaroni
- Department of Medicine and Surgery, University of Insubria, via H Dunant 5, 21100 Varese, Italy; (D.B.); (A.B.); (M.B.); (F.M.); (A.B.)
- Centre of Neuroscience, University of Insubria, 21100 Varese, Italy
| | - Andreina Baj
- Department of Medicine and Surgery, University of Insubria, via H Dunant 5, 21100 Varese, Italy; (D.B.); (A.B.); (M.B.); (F.M.); (A.B.)
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48
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Puthanmadhom Narayanan S, O'Brien D, Sharma M, Miller K, Adams P, Passos JF, Eirin A, Ordog T, Bharucha AE. Duodenal mucosal mitochondrial gene expression is associated with delayed gastric emptying in diabetic gastroenteropathy. JCI Insight 2021; 6:143596. [PMID: 33491664 PMCID: PMC7934845 DOI: 10.1172/jci.insight.143596] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 12/03/2020] [Indexed: 12/14/2022] Open
Abstract
Hindered by a limited understanding of the mechanisms responsible for diabetic gastroenteropathy (DGE), management is symptomatic. We investigated the duodenal mucosal expression of protein-coding genes and microRNAs (miRNA) in DGE and related them to clinical features. The diabetic phenotype, gastric emptying, mRNA, and miRNA expression and ultrastructure of duodenal mucosal biopsies were compared in 39 DGE patients and 21 controls. Among 3175 differentially expressed genes (FDR < 0.05), several mitochondrial DNA–encoded (mtDNA-encoded) genes (12 of 13 protein coding genes involved in oxidative phosphorylation [OXPHOS], both rRNAs and 9 of 22 transfer RNAs) were downregulated; conversely, nuclear DNA–encoded (nDNA-encoded) mitochondrial genes (OXPHOS) were upregulated in DGE. The promoters of differentially expressed genes were enriched in motifs for transcription factors (e.g., NRF1), which regulate mitochondrial biogenesis. Seventeen of 30 differentially expressed miRNAs targeted differentially expressed mitochondrial genes. Mitochondrial density was reduced and correlated with expression of 9 mtDNA OXPHOS genes. Uncovered by principal component (PC) analysis of 70 OXPHOS genes, PC1 was associated with neuropathy (P = 0.01) and delayed gastric emptying (P < 0.05). In DGE, mtDNA- and nDNA-encoded mitochondrial genes are reduced and increased — associated with reduced mitochondrial density, neuropathy, and delayed gastric emptying — and correlated with cognate miRNAs. These findings suggest that mitochondrial disturbances may contribute to delayed gastric emptying in DGE.
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Affiliation(s)
| | - Daniel O'Brien
- Department of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota, USA
| | - Mayank Sharma
- Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | - Karl Miller
- Sanford Burnham Prebys Medical Discovery Institute, San Diego, California, USA
| | - Peter Adams
- Sanford Burnham Prebys Medical Discovery Institute, San Diego, California, USA
| | - João F Passos
- Department of Physiology and Biomedical Engineering and
| | - Alfonso Eirin
- Division of Nephrology & Hypertension Research, Department of Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | - Tamas Ordog
- Department of Physiology and Biomedical Engineering and
| | - Adil E Bharucha
- Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, Minnesota, USA
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49
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Huang Z, Liao L, Wang Z, Lu Y, Yan W, Cao H, Tan B. An efficient approach for wholemount preparation of the myenteric plexus of rat colon. J Neurosci Methods 2021; 348:109012. [PMID: 33249181 DOI: 10.1016/j.jneumeth.2020.109012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 11/15/2020] [Accepted: 11/24/2020] [Indexed: 12/12/2022]
Abstract
BACKGROUND The nerve plexus of the enteric nervous system (ENS) plays a crucial part in regulating gastrointestinal functions, such as muscle contractile activity and nutrient absorption. Studying the nerve plexus can provide vital information for research on ENS disorders. Whole-mount preparation is an important technique for investigating the nerve plexus. However, currently available methods are time consuming and highly technical. NEW METHOD This study describes a simple and rapid method for preparing whole mounts of the longitudinal muscle and myenteric plexuses (LMMPs) of rat colon. Integral LMMPs can be easily separated from the underlying layer by using glass rods and wet cotton swabs. RESULTS The proposed method allows the easy separation of the LMMPs in intact sheets. Immunofluorescence histochemical staining of whole mounts enable clear visualization of enteric ganglia, nerve fibers, and several subtypes of neuronal populations residing in the myenteric plexus. COMPARISON WITH EXISTING METHODS Compared with existing procedures for whole-mount preparations, the proposed method achieves a quicker and more efficient preparation of high-quality LMMPs from intestinal segments in sufficient quantity. CONCLUSIONS This work provides a rapid method for efficiently preparing whole mounts of the intestines. Our method can be used for in situ observation of the morphological and functional alterations of the myenteric plexus for further studies on the ENS.
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Affiliation(s)
- Zitong Huang
- Research Center for Integrative Medicine, School of Basic Medical Sciences, Guangzhou University of Chinese Medicine, Guangzhou, PR China
| | - Lu Liao
- Research Center for Integrative Medicine, School of Basic Medical Sciences, Guangzhou University of Chinese Medicine, Guangzhou, PR China
| | - Zhesheng Wang
- Research Center for Integrative Medicine, School of Basic Medical Sciences, Guangzhou University of Chinese Medicine, Guangzhou, PR China
| | - Yulin Lu
- Research Center for Integrative Medicine, School of Basic Medical Sciences, Guangzhou University of Chinese Medicine, Guangzhou, PR China
| | - Weiming Yan
- The Third Clinical Medical College, Guangzhou University of Chinese Medicine, Guangzhou, PR China
| | - Hongying Cao
- School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou, PR China
| | - Bo Tan
- Research Center for Integrative Medicine, School of Basic Medical Sciences, Guangzhou University of Chinese Medicine, Guangzhou, PR China.
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50
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Joly A, Leulier F, De Vadder F. Microbial Modulation of the Development and Physiology of the Enteric Nervous System. Trends Microbiol 2020; 29:686-699. [PMID: 33309188 DOI: 10.1016/j.tim.2020.11.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 11/11/2020] [Accepted: 11/13/2020] [Indexed: 12/15/2022]
Abstract
The gastrointestinal tract harbors an intrinsic neuronal network, the enteric nervous system (ENS). The ENS controls motility, fluid homeostasis, and blood flow, but also interacts with other components of the intestine such as epithelial and immune cells. Recent studies indicate that gut microbiota diversification, which occurs alongside postnatal ENS maturation, could be critical for the development and function of the ENS. Here we discuss the possibility that this functional relationship starts in utero, whereby the maternal microbiota would prime the developing ENS and shape its physiology. We review ENS/microbiota interactions and their modulation in physiological and pathophysiological contexts. While microbial modulation of the ENS physiology is now well established, further studies are required to understand the contribution of the gut microbiota to the development and pathology of the ENS and to reveal the precise mechanisms underlying microbiota-to-ENS communications.
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Affiliation(s)
- Amélie Joly
- Institut de Génomique Fonctionnelle de Lyon, Université de Lyon, École Normale Supérieure de Lyon, Centre National de la Recherche Scientifique, Université Claude Bernard Lyon 1, UMR5242, Lyon, France
| | - François Leulier
- Institut de Génomique Fonctionnelle de Lyon, Université de Lyon, École Normale Supérieure de Lyon, Centre National de la Recherche Scientifique, Université Claude Bernard Lyon 1, UMR5242, Lyon, France
| | - Filipe De Vadder
- Institut de Génomique Fonctionnelle de Lyon, Université de Lyon, École Normale Supérieure de Lyon, Centre National de la Recherche Scientifique, Université Claude Bernard Lyon 1, UMR5242, Lyon, France.
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