1
|
Seguella L, Palenca I, Franzin SB, Zilli A, Esposito G. Mini-review: Interaction between intestinal microbes and enteric glia in health and disease. Neurosci Lett 2023; 806:137221. [PMID: 37031943 DOI: 10.1016/j.neulet.2023.137221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 03/24/2023] [Accepted: 03/31/2023] [Indexed: 04/11/2023]
Abstract
Enteric glia are a unique population of peripheral neuroglia associated with the enteric nervous system (ENS) throughout the digestive tract. The emerging data from the latest glial biology studies unveiled enteric glia as a heterogenic population with plastic and adaptative abilities that display phenotypic and functional changes upon distinct extrinsic cues. This aspect is essential in the dynamic signaling that enteric glia engage with neurons and other neighboring cells within the intestinal wall, such as epithelial, endocrine, and immune cells to maintain local homeostasis. Likewise, enteric glia sense signals from luminal microbes, although the extent of this active communication is still unclear. In this minireview, we discuss the recent findings that support glia-microbes crosstalk in the intestine in health and disease, pointing out the critical aspects that require further investigation.
Collapse
Affiliation(s)
- Luisa Seguella
- Department of Physiology and Pharmacology "V. Erspamer", Sapienza University of Rome, Italy.
| | - Irene Palenca
- Department of Physiology and Pharmacology "V. Erspamer", Sapienza University of Rome, Italy.
| | - Silvia Basili Franzin
- Department of Physiology and Pharmacology "V. Erspamer", Sapienza University of Rome, Italy.
| | - Aurora Zilli
- Department of Physiology and Pharmacology "V. Erspamer", Sapienza University of Rome, Italy.
| | - Giuseppe Esposito
- Department of Physiology and Pharmacology "V. Erspamer", Sapienza University of Rome, Italy.
| |
Collapse
|
2
|
Johnson AC, Louwies T, Ligon CO, Greenwood-Van Meerveld B. Enlightening the frontiers of neurogastroenterology through optogenetics. Am J Physiol Gastrointest Liver Physiol 2020; 319:G391-G399. [PMID: 32755304 PMCID: PMC7717115 DOI: 10.1152/ajpgi.00384.2019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Neurogastroenterology refers to the study of the extrinsic and intrinsic nervous system circuits controlling the gastrointestinal (GI) tract. Over the past 5-10 yr there has been an explosion in novel methodologies, technologies and approaches that offer great promise to advance our understanding of the basic mechanisms underlying GI function in health and disease. This review focuses on the use of optogenetics combined with electrophysiology in the field of neurogastroenterology. We discuss how these technologies and tools are currently being used to explore the brain-gut axis and debate the future research potential and limitations of these techniques. Taken together, we consider that the use of these technologies will enable researchers to answer important questions in neurogastroenterology through fundamental research. The answers to those questions will shorten the path from basic discovery to new treatments for patient populations with disorders of the brain-gut axis affecting the GI tract such as irritable bowel syndrome (IBS), functional dyspepsia, achalasia, and delayed gastric emptying.
Collapse
Affiliation(s)
- Anthony C. Johnson
- 1Oklahoma Center for Neuroscience, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma,2Oklahoma City Veterans Affairs Health Care System, Oklahoma City, Oklahoma,3Department of Neurology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Tijs Louwies
- 1Oklahoma Center for Neuroscience, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Casey O. Ligon
- 1Oklahoma Center for Neuroscience, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Beverley Greenwood-Van Meerveld
- 1Oklahoma Center for Neuroscience, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma,2Oklahoma City Veterans Affairs Health Care System, Oklahoma City, Oklahoma,4Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| |
Collapse
|
3
|
Deschenes MR, Tufts HL, Oh J, Li S, Noronha AL, Adan MA. Effects of exercise training on neuromuscular junctions and their active zones in young and aged muscles. Neurobiol Aging 2020; 95:1-8. [PMID: 32739557 DOI: 10.1016/j.neurobiolaging.2020.07.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 07/01/2020] [Accepted: 07/02/2020] [Indexed: 12/28/2022]
Abstract
The neuromuscular junction (NMJ) connects the motor neuron with myofibers allowing muscle contraction. Both aging and increased activity result in NMJ remodeling. Here, the effects of exercise were examined in young and aged soleus muscles. Using immunofluorescent staining procedures, cellular and active zone components of the NMJ were quantified following a treadmill running program. Immunofluorescence was employed to determine myofiber profiles (size and type). Two-way analysis of variance procedures with main effects of age and treatment showed that when analyzing NMJs at the cellular level, significant (p ≤ 0.05) effects were identified for age, but not treatment. However, when examining subcellular active zones, effects for exercise, but not for age, were detected. Myofiber cross-sectional area showed that aging elicited atrophy and that among younger muscles endurance exercise training yielded decrements in myofiber size. Conversely, among aged muscles training elicited whole muscle and myofiber trends (p < 0.10) toward hypertrophy. Thus, different components of the neuromuscular system harbor unique sensitivities to various stimuli enabling proper adaptations to attain optimal function under differing conditions.
Collapse
Affiliation(s)
- Michael R Deschenes
- Department of Kinesiology & Health Sciences, College of William & Mary, Williamsburg, VA, USA; Program in Neuroscience, College of William & Mary, Williamsburg, VA, USA.
| | - Hannah L Tufts
- Program in Neuroscience, College of William & Mary, Williamsburg, VA, USA
| | - Jeongeun Oh
- Department of Kinesiology & Health Sciences, College of William & Mary, Williamsburg, VA, USA
| | - Shuhan Li
- Department of Kinesiology & Health Sciences, College of William & Mary, Williamsburg, VA, USA
| | - Alexa L Noronha
- Department of Kinesiology & Health Sciences, College of William & Mary, Williamsburg, VA, USA
| | - Matthew A Adan
- Department of Kinesiology & Health Sciences, College of William & Mary, Williamsburg, VA, USA
| |
Collapse
|
4
|
Canals M, Poole DP, Veldhuis NA, Schmidt BL, Bunnett NW. G-Protein-Coupled Receptors Are Dynamic Regulators of Digestion and Targets for Digestive Diseases. Gastroenterology 2019; 156:1600-1616. [PMID: 30771352 PMCID: PMC6508858 DOI: 10.1053/j.gastro.2019.01.266] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 12/15/2018] [Accepted: 01/08/2019] [Indexed: 01/11/2023]
Abstract
G-protein-coupled receptors (GPCRs) are the largest family of transmembrane signaling proteins. In the gastrointestinal tract, GPCRs expressed by epithelial cells sense contents of the lumen, and GPCRs expressed by epithelial cells, myocytes, neurons, and immune cells participate in communication among cells. GPCRs control digestion, mediate digestive diseases, and coordinate repair and growth. GPCRs are the target of more than one third of therapeutic drugs, including many drugs used to treat digestive diseases. Recent advances in structural, chemical, and cell biology research have shown that GPCRs are not static binary switches that operate from the plasma membrane to control a defined set of intracellular signals. Rather, GPCRs are dynamic signaling proteins that adopt distinct conformations and subcellular distributions when associated with different ligands and intracellular effectors. An understanding of the dynamic nature of GPCRs has provided insights into the mechanism of activation and signaling of GPCRs and has shown opportunities for drug discovery. We review the allosteric modulation, biased agonism, oligomerization, and compartmentalized signaling of GPCRs that control digestion and digestive diseases. We highlight the implications of these concepts for the development of selective and effective drugs to treat diseases of the gastrointestinal tract.
Collapse
Affiliation(s)
- Meritxell Canals
- Centre for Membrane Proteins and Receptors (COMPARE), School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Daniel P. Poole
- Monash Institute of Pharmaceutical Sciences and Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, Victoria, Australia,Department of Anatomy and Neuroscience, University of Melbourne, Parkville, Victoria, Australia
| | - Nicholas A. Veldhuis
- Monash Institute of Pharmaceutical Sciences and Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, Victoria, Australia
| | - Brian L. Schmidt
- Bluestone Center for Clinical Research, New York University College of Dentistry, New York, New York
| | - Nigel W. Bunnett
- Monash Institute of Pharmaceutical Sciences and Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, Victoria, Australia,Department of Pharmacology and Therapeutics, University of Melbourne, Parkville, Victoria, Australia,Columbia University College of Physicians and Surgeons, Columbia University, New York, New York
| |
Collapse
|
5
|
Bellodas Sanchez J, Kadrofske M. Necrotizing enterocolitis. Neurogastroenterol Motil 2019; 31:e13569. [PMID: 30793842 DOI: 10.1111/nmo.13569] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2018] [Revised: 01/15/2019] [Accepted: 01/17/2019] [Indexed: 12/12/2022]
Abstract
Necrotizing enterocolitis (NEC) is an acute inflammatory disease of the intestine which primarily affects preterm infants and is a leading cause of morbidity and mortality in the neonatal intensive care unit. From a clinical standpoint, and during the early course of the disease, NEC can be difficult to distinguish from other diseases and conditions common to the preterm infant, and this warrants the need for specific disease biomarkers. The pathogenesis of NEC is only partly understood but likely involves an altered intestinal barrier immune response to feeding and the developing microbiome. Recent evidence points toward a role of the enteric nervous system in NEC pathogenesis. In this issue, Meister and colleagues use a rodent model of NEC to demonstrate that NEC is associated with diminished vagal tone, as determined by decreased high-frequency heart rate variability (HF-HRV), and altered myenteric nitrergic inhibitory neurotransmission. These results augment their previous findings that describe decreased HF-HRV in human preterm infants with NEC. This mini-review provides a brief summary of clinical and pathophysiologic aspects of NEC with focus on certain aspects of neurogastroenterology.
Collapse
Affiliation(s)
- Jenny Bellodas Sanchez
- Neonatal-Perinatal Medicine Fellowship Program, Michigan State University and Sparrow Hospital, Lansing, Michigan
| | - Mark Kadrofske
- Department of Pediatrics and Human Development, Division of Neonatology, Michigan State University, East Lansing, Michigan
| |
Collapse
|
6
|
Sharkey KA, Beck PL, McKay DM. Neuroimmunophysiology of the gut: advances and emerging concepts focusing on the epithelium. Nat Rev Gastroenterol Hepatol 2018; 15:765-784. [PMID: 30069036 DOI: 10.1038/s41575-018-0051-4] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The epithelial lining of the gastrointestinal tract serves as the interface for digestion and absorption of nutrients and water and as a defensive barrier. The defensive functions of the intestinal epithelium are remarkable considering that the gut lumen is home to trillions of resident bacteria, fungi and protozoa (collectively, the intestinal microbiota) that must be prevented from translocation across the epithelial barrier. Imbalances in the relationship between the intestinal microbiota and the host lead to the manifestation of diseases that range from disorders of motility and sensation (IBS) and intestinal inflammation (IBD) to behavioural and metabolic disorders, including autism and obesity. The latest discoveries shed light on the sophisticated intracellular, intercellular and interkingdom signalling mechanisms of host defence that involve epithelial and enteroendocrine cells, the enteric nervous system and the immune system. Together, they maintain homeostasis by integrating luminal signals, including those derived from the microbiota, to regulate the physiology of the gastrointestinal tract in health and disease. Therapeutic strategies are being developed that target these signalling systems to improve the resilience of the gut and treat the symptoms of gastrointestinal disease.
Collapse
Affiliation(s)
- Keith A Sharkey
- Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada. .,Snyder Institute for Chronic Diseases, University of Calgary, Calgary, Alberta, Canada. .,Gastrointestinal Research Group, University of Calgary, Calgary, Alberta, Canada. .,Department of Physiology & Pharmacology, University of Calgary, Calgary, Alberta, Canada.
| | - Paul L Beck
- Snyder Institute for Chronic Diseases, University of Calgary, Calgary, Alberta, Canada.,Gastrointestinal Research Group, University of Calgary, Calgary, Alberta, Canada.,Inflammation Research Network, University of Calgary, Calgary, Alberta, Canada.,Division of Gastroenterology and Hepatology, University of Calgary, Calgary, Alberta, Canada.,Department of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Derek M McKay
- Snyder Institute for Chronic Diseases, University of Calgary, Calgary, Alberta, Canada.,Gastrointestinal Research Group, University of Calgary, Calgary, Alberta, Canada.,Department of Physiology & Pharmacology, University of Calgary, Calgary, Alberta, Canada.,Inflammation Research Network, University of Calgary, Calgary, Alberta, Canada
| |
Collapse
|
7
|
Opportunities and Challenges for Single-Unit Recordings from Enteric Neurons in Awake Animals. MICROMACHINES 2018; 9:mi9090428. [PMID: 30424361 PMCID: PMC6187697 DOI: 10.3390/mi9090428] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 08/17/2018] [Accepted: 08/23/2018] [Indexed: 12/18/2022]
Abstract
Advanced electrode designs have made single-unit neural recordings commonplace in modern neuroscience research. However, single-unit resolution remains out of reach for the intrinsic neurons of the gastrointestinal system. Single-unit recordings of the enteric (gut) nervous system have been conducted in anesthetized animal models and excised tissue, but there is a large physiological gap between awake and anesthetized animals, particularly for the enteric nervous system. Here, we describe the opportunity for advancing enteric neuroscience offered by single-unit recording capabilities in awake animals. We highlight the primary challenges to microelectrodes in the gastrointestinal system including structural, physiological, and signal quality challenges, and we provide design criteria recommendations for enteric microelectrodes.
Collapse
|
8
|
Boesmans W, Hao MM, Vanden Berghe P. Optogenetic and chemogenetic techniques for neurogastroenterology. Nat Rev Gastroenterol Hepatol 2018; 15:21-38. [PMID: 29184183 DOI: 10.1038/nrgastro.2017.151] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Optogenetics and chemogenetics comprise a wide variety of applications in which genetically encoded actuators and indicators are used to modulate and monitor activity with high cellular specificity. Over the past 10 years, development of these genetically encoded tools has contributed tremendously to our understanding of integrated physiology. In concert with the continued refinement of probes, strategies to target transgene expression to specific cell types have also made much progress in the past 20 years. In addition, the successful implementation of optogenetic and chemogenetic techniques thrives thanks to ongoing advances in live imaging microscopy and optical technology. Although innovation of optogenetic and chemogenetic methods has been primarily driven by researchers studying the central nervous system, these techniques also hold great promise to boost research in neurogastroenterology. In this Review, we describe the different classes of tools that are currently available and give an overview of the strategies to target them to specific cell types in the gut wall. We discuss the possibilities and limitations of optogenetic and chemogenetic technology in the gut and provide an overview of their current use, with a focus on the enteric nervous system. Furthermore, we suggest some experiments that can advance our understanding of how the intrinsic and extrinsic neural networks of the gut control gastrointestinal function.
Collapse
Affiliation(s)
- Werend Boesmans
- Laboratory for Enteric Neuroscience (LENS), Translational Research Center for Gastrointestinal Disorders (TARGID), University of Leuven, Herestraat 49, O&N 1 Box 701, 3000 Leuven, Belgium.,Department of Pathology, Maastricht University Medical Center, P. Debeijelaan 25, 6229 HX, Maastricht, The Netherlands
| | - Marlene M Hao
- Laboratory for Enteric Neuroscience (LENS), Translational Research Center for Gastrointestinal Disorders (TARGID), University of Leuven, Herestraat 49, O&N 1 Box 701, 3000 Leuven, Belgium.,Department of Anatomy and Neuroscience, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Pieter Vanden Berghe
- Laboratory for Enteric Neuroscience (LENS), Translational Research Center for Gastrointestinal Disorders (TARGID), University of Leuven, Herestraat 49, O&N 1 Box 701, 3000 Leuven, Belgium
| |
Collapse
|