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Govindappa PK, Begom M, Gupta Y, Elfar JC, Rawat M, Elfar W. A critical role for erythropoietin on vagus nerve Schwann cells in intestinal motility. BMC Biotechnol 2023; 23:12. [PMID: 37127673 PMCID: PMC10152589 DOI: 10.1186/s12896-023-00781-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Accepted: 03/30/2023] [Indexed: 05/03/2023] Open
Abstract
BACKGROUND Dysmotility and postoperative ileus (POI) are frequent major clinical problems post-abdominal surgery. Erythropoietin (EPO) is a multifunctional tissue-protective cytokine that promotes recovery of the intestine in various injury models. While EPO receptors (EPOR) are present in vagal Schwann cells, the role of EPOR in POI recovery is unknown because of the lack of EPOR antagonists or Schwann-cell specific EPOR knockout animals. This study was designed to explore the effect of EPO via EPOR in vagal nerve Schwann cells in a mouse model of POI. RESULTS The structural features of EPOR and its activation by EPO-mediated dimerization were understood using structural analysis. Later, using the Cre-loxP system, we developed a myelin protein zero (Mpz) promoter-driven knockout mouse model of Schwann cell EPOR (MpzCre-EPORflox/flox / Mpz-EPOR-KO) confirmed using PCR and qRT-PCR techniques. We then measured the intestinal transit time (ITT) at baseline and after induction of POI with and without EPO treatment. Although we have previously shown that EPO accelerates functional recovery in POI in wild type mice, EPO treatment did not improve functional recovery of ITT in POI of Mpz-EPOR-KO mice. CONCLUSIONS To the best of our knowledge, this is the first pre-clinical study to demonstrate a novel mouse model of EPOR specific knock out on Schwan cells with an effect in the gut. We also showed novel beneficial effects of EPO through vagus nerve Schwann cell-EPOR in intestinal dysmotility. Our findings suggest that EPO-EPOR signaling in the vagus nerve after POI is important for the functional recovery of ITT.
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Affiliation(s)
- Prem Kumar Govindappa
- Department of Orthopaedics and Sports Medicine, University of Arizona College of Medicine, Tucson, AZ, 85724, USA
| | - Mosammat Begom
- Department of Medicine, The Penn State University College of Medicine, Hershey, PA, 17033, USA
| | - Yash Gupta
- Department of Medicine, The Penn State University College of Medicine, Hershey, PA, 17033, USA
| | - John C Elfar
- Department of Orthopaedics and Sports Medicine, University of Arizona College of Medicine, Tucson, AZ, 85724, USA
| | - Manmeet Rawat
- Department of Medicine, The Penn State University College of Medicine, Hershey, PA, 17033, USA.
| | - Walaa Elfar
- Department of Pediatrics, University of Arizona College of Medicine, Tucson, AZ, 85724, USA.
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Wang Y, Zhan G, Cai Z, Jiao B, Zhao Y, Li S, Luo A. Vagus nerve stimulation in brain diseases: Therapeutic applications and biological mechanisms. Neurosci Biobehav Rev 2021; 127:37-53. [PMID: 33894241 DOI: 10.1016/j.neubiorev.2021.04.018] [Citation(s) in RCA: 66] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2020] [Revised: 04/12/2021] [Accepted: 04/18/2021] [Indexed: 12/21/2022]
Abstract
Brain diseases, including neurodegenerative, cerebrovascular and neuropsychiatric diseases, have posed a deleterious threat to human health and brought a great burden to society and the healthcare system. With the development of medical technology, vagus nerve stimulation (VNS) has been approved by the Food and Drug Administration (FDA) as an alternative treatment for refractory epilepsy, refractory depression, cluster headaches, and migraines. Furthermore, current evidence showed promising results towards the treatment of more brain diseases, such as Parkinson's disease (PD), autistic spectrum disorder (ASD), traumatic brain injury (TBI), and stroke. Nonetheless, the biological mechanisms underlying the beneficial effects of VNS in brain diseases remain only partially elucidated. This review aims to delve into the relevant preclinical and clinical studies and update the progress of VNS applications and its potential mechanisms underlying the biological effects in brain diseases.
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Affiliation(s)
- Yue Wang
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
| | - Gaofeng Zhan
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
| | - Ziwen Cai
- Department of Cardiovascular Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
| | - Bo Jiao
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
| | - Yilin Zhao
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
| | - Shiyong Li
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
| | - Ailin Luo
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
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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: 73] [Impact Index Per Article: 12.2] [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.
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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
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Abstract
BACKGROUND How vagotomy affects host responses to gut ischemia-reperfusion (I/R) is unclear. MATERIALS AND METHODS Experiment 1: male Institute of Cancer Research mice (n = 22) were assigned to the I/R or the vago-I/R group. The I/R mice underwent 45-min superior mesenteric artery (SMA) occlusion. The vago-I/R mice received vagotomy before SMA occlusion. Survival was observed for 48 h.Experiment 2: mice (n = 55) were divided into four groups (Sham, vago, I/R, vago-I/R). Sham and vago groups did not undergo gut I/R. Mice were killed at 3 or 6 h after reperfusion, and cytokine levels in the plasma, jejunum, and ileum were evaluated. In addition, gut histology at 6 h was examined.Experiment 3: mice (n = 24) were divided into four groups as in Experiment 2. The small intestine was harvested at 3 h after reperfusion and the tissue was cultured ex vivo for 3 h. Cytokine levels of the culture supernatant were then measured. RESULTS Experiment 1: survival was significantly worse with vago-I/R than I/R.Experiment 2: along with severe gut injury, vago-I/R increased IL-6 and monocyte chemoattractant protein-1 (MCP-1) in plasma, IFN-γ in the jejunum and MCP-1 in the ileum, as compared with I/R. Significant positive correlations were noted between plasma and intestinal levels of pro-inflammatory cytokines (IL-6, MCP-1, and TNF-α).Experiment 3: MCP-1 in the jejunal culture medium was higher in the vago-I/R than in the I/R group. CONCLUSIONS Vagotomy worsens survival after gut I/R, together with increases in pro-inflammatory cytokines in both plasma and the gut in association with severe intestinal tissue damage.
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Langness S, Kojima M, Coimbra R, Eliceiri BP, Costantini TW. Enteric glia cells are critical to limiting the intestinal inflammatory response after injury. Am J Physiol Gastrointest Liver Physiol 2017; 312:G274-G282. [PMID: 28082286 DOI: 10.1152/ajpgi.00371.2016] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Revised: 01/05/2017] [Accepted: 01/05/2017] [Indexed: 02/06/2023]
Abstract
Vagal nerve stimulation (VNS) has been shown to limit intestinal inflammation following injury; however, a direct connection between vagal terminals and resident intestinal immune cells has yet to be identified. We have previously shown that enteric glia cell (EGC) expression is increased after injury through a vagal-mediated pathway to help restore gut barrier function. We hypothesize that EGCs modulate immune cell recruitment following injury and relay vagal anti-inflammatory signals to resident immune cells in the gut. EGCs were selectively ablated from an isolated segment of distal bowel with topical application of benzalkonium chloride (BAC) in male mice. Three days following BAC application, mice were subjected to an ischemia-reperfusion injury (I/R) by superior mesenteric artery occlusion for 30 min. VNS was performed in a separate cohort of animals. EGC+ and EGC- segments were compared utilizing histology, flow cytometry, immunohistochemistry, and intestinal permeability. VNS significantly reduced immune cell recruitment after I/R injury in EGC+ segments with cell percentages similar to sham. VNS failed to limit immune cell recruitment in EGC- segments. Histologic evidence of gut injury was diminished with VNS application in EGC+ segments, whereas EGC- segments showed features of more severe injury. Intestinal permeability increased following I/R injury in both EGC+ and EGC- segments. Permeability was significantly lower after VNS application compared with injury alone in EGC+ segments only (95.1 ± 30.0 vs. 217.6 ± 21.7 μg/ml, P < 0.05). Therefore, EGC ablation uncouples the protective effects of VNS, suggesting that vagal-mediated signals are translated to effector cells through EGCs.NEW & NOTEWORTHY Intestinal inflammation is initiated by local immune cell activation and epithelial barrier breakdown, resulting in the production of proinflammatory mediators with subsequent leukocyte recruitment. Vagal nerve stimulation (VNS) has been shown to limit intestinal inflammation following injury; however, direct connection between vagal terminals and resident intestinal immune cells has yet to be identified. Here, we demonstrate that intact enteric glia cells are required to transmit the gut anti-inflammatory effects of VNS.
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Affiliation(s)
- Simone Langness
- Division of Trauma, Surgical Critical Care, Burns, and Acute Care Surgery, Department of Surgery, University of California, San Diego Health Sciences, San Diego, California
| | - Mitsuaki Kojima
- Division of Trauma, Surgical Critical Care, Burns, and Acute Care Surgery, Department of Surgery, University of California, San Diego Health Sciences, San Diego, California
| | - Raul Coimbra
- Division of Trauma, Surgical Critical Care, Burns, and Acute Care Surgery, Department of Surgery, University of California, San Diego Health Sciences, San Diego, California
| | - Brian P Eliceiri
- Division of Trauma, Surgical Critical Care, Burns, and Acute Care Surgery, Department of Surgery, University of California, San Diego Health Sciences, San Diego, California
| | - Todd W Costantini
- Division of Trauma, Surgical Critical Care, Burns, and Acute Care Surgery, Department of Surgery, University of California, San Diego Health Sciences, San Diego, California
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Browning KN, Verheijden S, Boeckxstaens GE. The Vagus Nerve in Appetite Regulation, Mood, and Intestinal Inflammation. Gastroenterology 2017; 152:730-744. [PMID: 27988382 PMCID: PMC5337130 DOI: 10.1053/j.gastro.2016.10.046] [Citation(s) in RCA: 189] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 09/27/2016] [Accepted: 10/27/2016] [Indexed: 02/07/2023]
Abstract
Although the gastrointestinal tract contains intrinsic neural plexuses that allow a significant degree of independent control over gastrointestinal functions, the central nervous system provides extrinsic neural inputs that modulate, regulate, and integrate these functions. In particular, the vagus nerve provides the parasympathetic innervation to the gastrointestinal tract, coordinating the complex interactions between central and peripheral neural control mechanisms. This review discusses the physiological roles of the afferent (sensory) and motor (efferent) vagus in regulation of appetite, mood, and the immune system, as well as the pathophysiological outcomes of vagus nerve dysfunction resulting in obesity, mood disorders, and inflammation. The therapeutic potential of vagus nerve modulation to attenuate or reverse these pathophysiological outcomes and restore autonomic homeostasis is also discussed.
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Affiliation(s)
- Kirsteen N. Browning
- Department of Neural and Behavioral Science Penn State College of Medicine 500 University Drive MC H109 Hershey, PA 17033
| | - Simon Verheijden
- Translational Research Center of Gastrointestinal Disorders (TARGID) KU Leuven Herestraat 49 3000 Leuven, Belgium
| | - Guy E. Boeckxstaens
- Translational Research Center of Gastrointestinal Disorders (TARGID) KU Leuven Herestraat 49 3000 Leuven, Belgium,Division of Gastroenterology & Hepatology University Hospital Leuven Herestraat 49 3000 Leuven, Belgium,Address of correspondence: Prof. dr. Guy Boeckxstaens,
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Therapeutic Potentials of Enteric Nerve Activation with Vagus Nerve Stimulation. J Am Coll Surg 2016; 222:103-5. [PMID: 26721757 DOI: 10.1016/j.jamcollsurg.2015.10.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Accepted: 10/15/2015] [Indexed: 11/23/2022]
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