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Kumar KP, Wilson JL, Nguyen H, McKay LD, Wen SW, Sepehrizadeh T, de Veer M, Rajasekhar P, Carbone SE, Hickey MJ, Poole DP, Wong CHY. Stroke Alters the Function of Enteric Neurons to Impair Smooth Muscle Relaxation and Dysregulates Gut Transit. J Am Heart Assoc 2024; 13:e033279. [PMID: 38258657 PMCID: PMC11056134 DOI: 10.1161/jaha.123.033279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2023] [Accepted: 12/05/2023] [Indexed: 01/24/2024]
Abstract
BACKGROUND Gut dysmotility is common after ischemic stroke, but the mechanism underlying this response is unknown. Under homeostasis, gut motility is regulated by the neurons of the enteric nervous system that control contractile/relaxation activity of muscle cells in the gut wall. More recently, studies of gut inflammation revealed interactions of macrophages with enteric neurons are also involved in modulating gut motility. However, whether poststroke gut dysmotility is mediated by direct signaling to the enteric nervous system or indirectly via inflammatory macrophages is unknown. METHODS AND RESULTS We examined these hypotheses by using a clinically relevant permanent intraluminal midcerebral artery occlusion experimental model of stroke. At 24 hours after stroke, we performed in vivo and ex vivo gut motility assays, flow cytometry, immunofluorescence, and transcriptomic analysis. Stroke-induced gut dysmotility was associated with recruitment of muscularis macrophages into the gastrointestinal tract and redistribution of muscularis macrophages away from myenteric ganglia. The permanent intraluminal midcerebral artery occlusion model caused changes in gene expression in muscularis macrophages consistent with an altered phenotype. While the size of myenteric ganglia after stroke was not altered, myenteric neurons from post-permanent intraluminal midcerebral artery occlusion mice showed a reduction in neuronal nitric oxide synthase expression, and this response was associated with enhanced intestinal smooth muscle contraction ex vivo. Finally, chemical sympathectomy with 6-hydroxydopamine prevented the loss of myenteric neuronal nitric oxide synthase expression and stroke-induced slowed gut transit. CONCLUSIONS Our findings demonstrate that activation of the sympathetic nervous system after stroke is associated with reduced neuronal nitric oxide synthase expression in myenteric neurons, resulting in impaired smooth muscle relaxation and dysregulation of gut transit.
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Affiliation(s)
- Kathryn Prame Kumar
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences at Monash Health, Monash Medical CentreMonash UniversityClaytonVictoriaAustralia
| | - Jenny L. Wilson
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences at Monash Health, Monash Medical CentreMonash UniversityClaytonVictoriaAustralia
| | - Huynh Nguyen
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences at Monash Health, Monash Medical CentreMonash UniversityClaytonVictoriaAustralia
| | - Liam D. McKay
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences at Monash Health, Monash Medical CentreMonash UniversityClaytonVictoriaAustralia
| | - Shu Wen Wen
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences at Monash Health, Monash Medical CentreMonash UniversityClaytonVictoriaAustralia
| | | | - Michael de Veer
- Monash Biomedical ImagingMonash UniversityClaytonVictoriaAustralia
| | - Pradeep Rajasekhar
- Centre for Dynamic ImagingWalter and Eliza Hall Institute of Medical ResearchParkvilleVictoriaAustralia
| | - Simona E. Carbone
- Drug Discovery Biology, Faculty of Pharmacy and Pharmaceutical SciencesMonash Institute of Pharmaceutical Sciences, Monash UniversityParkvilleVictoriaAustralia
| | - Michael J. Hickey
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences at Monash Health, Monash Medical CentreMonash UniversityClaytonVictoriaAustralia
| | - Daniel P. Poole
- Drug Discovery Biology, Faculty of Pharmacy and Pharmaceutical SciencesMonash Institute of Pharmaceutical Sciences, Monash UniversityParkvilleVictoriaAustralia
| | - Connie H. Y. Wong
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences at Monash Health, Monash Medical CentreMonash UniversityClaytonVictoriaAustralia
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2
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Prame Kumar K, McKay LD, Nguyen H, Kaur J, Wilson JL, Suthya AR, McKeown SJ, Abud HE, Wong CHY. Sympathetic-Mediated Intestinal Cell Death Contributes to Gut Barrier Impairment After Stroke. Transl Stroke Res 2023:10.1007/s12975-023-01211-y. [PMID: 38030854 DOI: 10.1007/s12975-023-01211-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 09/25/2023] [Accepted: 10/28/2023] [Indexed: 12/01/2023]
Abstract
Tissue injury induced by stroke is traditionally thought to be localised to the brain. However, there is an accumulating body of evidence to demonstrate that stroke promotes pathophysiological consequences in peripheral tissues including the gastrointestinal system. In this study, we investigated the mechanisms underlying gut permeability after stroke. We utilised the clinically relevant experimental model of stroke called permanent intraluminal middle cerebral artery occlusion (pMCAO) to examine the effect of cerebral ischaemia on the gut. We detected stroke-induced gut permeability at 5 h after pMCAO. At this timepoint, we observed significantly elevated intestinal epithelial cell death in post-stroke mice compared to their sham-operated counterparts. At 24 h after stroke onset when the gut barrier integrity is restored, our findings indicated that post-stroke intestinal epithelium had higher expression of genes associated with fructose metabolism, and hyperplasia of intestinal crypts and goblet cells, conceivably as a host compensatory mechanism to adapt to the impaired gut barrier. Furthermore, we discovered that stroke-induced gut permeability was mediated by the activation of the sympathetic nervous system as pharmacological denervation decreased the stroke-induced intestinal epithelial cell death, goblet cell and crypt hyperplasia, and gut permeability to baseline levels. Our study identifies a previously unknown mechanism in the brain-gut axis by which stroke triggers intestinal cell death and gut permeability.
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Affiliation(s)
- Kathryn Prame Kumar
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences at Monash Health, Monash Medical Centre, Monash University, Clayton, VIC, 3168, Australia
| | - Liam D McKay
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences at Monash Health, Monash Medical Centre, Monash University, Clayton, VIC, 3168, Australia
| | - Huynh Nguyen
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences at Monash Health, Monash Medical Centre, Monash University, Clayton, VIC, 3168, Australia
| | - Jasveena Kaur
- Department of Anatomy and Developmental Biology, Development and Stem Cells Program, Biomedical Discovery Institute, Monash University, Clayton, VIC, 3800, Australia
| | - Jenny L Wilson
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences at Monash Health, Monash Medical Centre, Monash University, Clayton, VIC, 3168, Australia
| | - Althea R Suthya
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences at Monash Health, Monash Medical Centre, Monash University, Clayton, VIC, 3168, Australia
| | - Sonja J McKeown
- Department of Anatomy and Developmental Biology, Development and Stem Cells Program, Biomedical Discovery Institute, Monash University, Clayton, VIC, 3800, Australia
| | - Helen E Abud
- Department of Anatomy and Developmental Biology, Development and Stem Cells Program, Biomedical Discovery Institute, Monash University, Clayton, VIC, 3800, Australia
| | - Connie H Y Wong
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences at Monash Health, Monash Medical Centre, Monash University, Clayton, VIC, 3168, Australia.
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3
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Tan Z, Hall P, Costin A, Crawford SA, Ramm G, Wong CHY, Kitching AR, Hickey MJ. Removal of the endothelial surface layer via hyaluronidase does not modulate monocyte and neutrophil interactions with the glomerular endothelium. Microcirculation 2023; 30:e12823. [PMID: 37494581 PMCID: PMC10909409 DOI: 10.1111/micc.12823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 07/13/2023] [Accepted: 07/14/2023] [Indexed: 07/28/2023]
Abstract
OBJECTIVE The endothelial surface layer (ESL), a layer of macromolecules on the surface of endothelial cells, can both impede and facilitate leukocyte recruitment. However, its role in monocyte and neutrophil recruitment in glomerular capillaries is unknown. METHODS We used multiphoton intravital microscopy to examine monocyte and neutrophil behavior in the glomerulus following ESL disruption with hyaluronidase. RESULTS Constitutive retention and migration of monocytes and neutrophils within the glomerular microvasculature was unaltered by hyaluronidase. Consistent with this, inhibition of the hyaluronan-binding molecule CD44 also failed to modulate glomerular trafficking of these immune cells. To investigate the contribution of the ESL during acute inflammation, we induced glomerulonephritis via in situ immune complex deposition. This resulted in increases in glomerular retention of monocytes and neutrophils but did not induce marked reduction in the glomerular ESL. Furthermore, hyaluronidase treatment did not modify the prolonged retention of monocytes and neutrophils in the acutely inflamed glomerular microvasculature. CONCLUSIONS These observations indicate that, despite evidence that the ESL has the capacity to inhibit leukocyte-endothelial cell interactions while also containing adhesive ligands for immune cells, neither of these functions modulate trafficking of monocytes and neutrophils in steady-state or acutely-inflamed glomeruli.
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Affiliation(s)
- ZheHao Tan
- Centre for Inflammatory Diseases, Monash University Department of MedicineMonash Medical CentreClaytonVictoriaAustralia
| | - Pam Hall
- Centre for Inflammatory Diseases, Monash University Department of MedicineMonash Medical CentreClaytonVictoriaAustralia
| | - Adam Costin
- Monash Ramaciotti Centre for Cryo‐Electron MicroscopyMonash UniversityClaytonVictoriaAustralia
| | - Simon A. Crawford
- Monash Ramaciotti Centre for Cryo‐Electron MicroscopyMonash UniversityClaytonVictoriaAustralia
| | - Georg Ramm
- Monash Ramaciotti Centre for Cryo‐Electron MicroscopyMonash UniversityClaytonVictoriaAustralia
| | - Connie H. Y. Wong
- Centre for Inflammatory Diseases, Monash University Department of MedicineMonash Medical CentreClaytonVictoriaAustralia
| | - A. Richard Kitching
- Centre for Inflammatory Diseases, Monash University Department of MedicineMonash Medical CentreClaytonVictoriaAustralia
- Department of NephrologyMonash Medical CentreClaytonVictoriaAustralia
- Department of Pediatric NephrologyMonash Medical CentreClaytonVictoriaAustralia
| | - Michael J. Hickey
- Centre for Inflammatory Diseases, Monash University Department of MedicineMonash Medical CentreClaytonVictoriaAustralia
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4
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Wen SW, Shim R, Hall P, Bedo J, Wilson JL, Nicholls AJ, Hickey MJ, Wong CHY. Lung Imaging Reveals Stroke-Induced Impairment in Pulmonary Intravascular Neutrophil Function, a Response Exacerbated with Aging. J Immunol 2022; 208:2019-2028. [PMID: 35365565 DOI: 10.4049/jimmunol.2100997] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 02/05/2022] [Indexed: 06/14/2023]
Abstract
In stroke patients, infection is a significant contributor to morbidity and mortality. Moreover, older stroke patients show an increased risk of developing stroke-associated infection, although the mechanisms underlying this increased susceptibility to infection are unknown. In this study, using an experimental mouse model of ischemic stroke, we showed that older (12-15 mo of age) mice had elevated lung bacterial infection and inflammatory damage after stroke when compared with young (8-10 wk of age) counterparts, despite undergoing the same degree of brain injury. Intravital microscopy of the lung microvasculature revealed that in younger mice, stroke promoted neutrophil arrest in pulmonary microvessels, but this response was not seen in older poststroke mice. In addition, bacterial phagocytosis by neutrophils in the lung microvasculature was reduced by both aging and stroke, such that neutrophils in aged poststroke mice showed the greatest impairment in this function. Analysis of neutrophil migration in vitro and in the cremaster muscle demonstrated that stroke alone did not negatively impact neutrophil migration, but that the combination of increased age and stroke led to reduced effectiveness of neutrophil chemotaxis. Transcriptomic analysis of pulmonary neutrophils using RNA sequencing identified 79 genes that were selectively altered in the context of combined aging and stroke, and they were associated with pathways that control neutrophil chemotaxis. Taken together, the findings of this study show that stroke in older animals results in worsening of neutrophil antibacterial responses and changes in neutrophil gene expression that have the potential to underpin elevated risk of stroke-associated infection in the context of increased age.
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Affiliation(s)
- Shu Wen Wen
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences, Monash University, Clayton, Victoria, Australia
| | - Raymond Shim
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences, Monash University, Clayton, Victoria, Australia
| | - Pam Hall
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences, Monash University, Clayton, Victoria, Australia
| | - Justin Bedo
- Bioinformatics Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia; and
- School of Computing and Information Systems, The University of Melbourne, Parkville, Victoria, Australia
| | - Jenny L Wilson
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences, Monash University, Clayton, Victoria, Australia
| | - Alyce J Nicholls
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences, Monash University, Clayton, Victoria, Australia
| | - Michael J Hickey
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences, Monash University, Clayton, Victoria, Australia
| | - Connie H Y Wong
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences, Monash University, Clayton, Victoria, Australia;
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5
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Shim R, Wilson JL, Phillips SE, Lambert GW, Wen SW, Wong CHY. The role of β 2 adrenergic receptor on infection development after ischaemic stroke. Brain Behav Immun Health 2021; 18:100393. [PMID: 34877554 PMCID: PMC8633818 DOI: 10.1016/j.bbih.2021.100393] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 10/31/2021] [Accepted: 11/21/2021] [Indexed: 01/17/2023] Open
Abstract
Mechanisms underlying post-stroke immune impairments and subsequent development of fatal lung infection have been suggested to involve multiple pathways, including hyperactivation of the sympathetic nervous system (SNS), which results in the excessive release of catecholamines and activation of β-adrenergic receptors (βARs). Indeed, previous reports from experimental studies demonstrated that post-stroke infection can be inhibited with treatment of β-blockers. However, the effectiveness of β-blockers in reducing post-stroke infection has yielded mixed results in retrospective clinical trials and its use remain controversial. In this study, we performed mid-cerebral artery occlusion in mice either genetically deficient in β2-adrenergic receptor (β2AR) or treated with non-selective and selective βAR antagonists to explore the contributions of the SNS in the development of post-stroke lung infection. Stroke induced a systemic activation of the SNS as indicated by elevated levels of plasma catecholamines and UCP-1 activity. However, β2AR deficient mice showed similar degrees of post-stroke immune impairment and infection rate compared to wildtype counterparts, potentially due to compensatory mechanisms common in transgenic animals. To overcome this, we treated post-stroke wildtype mice with pharmacological inhibitors of the βARs, including the non-selective antagonist propranolol (PPL) and selective β2AR antagonist ICI-118551. Both pharmacological strategies to block the action of SNS signalling were unable to reduce infection in mice that underwent ischaemic stroke. Overall, our data suggests that other mechanisms independent or in combination with β2AR activation contribute to the development of post-stroke infection. Ischaemic stroke induced a systemic activation of the sympathetic nervous system. Mice deficient of β2 adrenergic receptor showed similar post-stroke infection and signs of immune impairment compared to wildtype counterparts. Pharmacological blockade of sympathetic signalling was unable to reduce infection in mice after stroke.
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Affiliation(s)
- Raymond Shim
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences at Monash Health, Monash Medical Centre, Monash University, Clayton, Victoria, Australia
| | - Jenny L Wilson
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences at Monash Health, Monash Medical Centre, Monash University, Clayton, Victoria, Australia
| | - Sarah E Phillips
- Inversion Health Innovation Research Institute and School of Health Sciences, Swinburne University of Technology, Victoria, Australia.,Human Neurotransmitters Laboratory, Baker Heart and Diabetes Institute, Victoria, Australia
| | - Gavin W Lambert
- Inversion Health Innovation Research Institute and School of Health Sciences, Swinburne University of Technology, Victoria, Australia.,Human Neurotransmitters Laboratory, Baker Heart and Diabetes Institute, Victoria, Australia
| | - Shu Wen Wen
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences at Monash Health, Monash Medical Centre, Monash University, Clayton, Victoria, Australia
| | - Connie H Y Wong
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences at Monash Health, Monash Medical Centre, Monash University, Clayton, Victoria, Australia
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6
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Selvadurai MV, Moon MJ, Mountford SJ, Ma X, Zheng Z, Jennings IG, Setiabakti NM, Iman RP, Brazilek RJ, Z Abidin NA, Chicanne G, Severin S, Nicholls AJ, Wong CHY, Rinckel JY, Eckly A, Gachet C, Nesbitt WS, Thompson PE, Hamilton JR. Disrupting the platelet internal membrane via PI3KC2α inhibition impairs thrombosis independently of canonical platelet activation. Sci Transl Med 2021; 12:12/553/eaar8430. [PMID: 32718993 DOI: 10.1126/scitranslmed.aar8430] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 03/12/2020] [Accepted: 06/05/2020] [Indexed: 12/17/2022]
Abstract
Arterial thrombosis causes heart attacks and most strokes and is the most common cause of death in the world. Platelets are the cells that form arterial thrombi, and antiplatelet drugs are the mainstay of heart attack and stroke prevention. Yet, current drugs have limited efficacy, preventing fewer than 25% of lethal cardiovascular events without clinically relevant effects on bleeding. The key limitation on the ability of all current drugs to impair thrombosis without causing bleeding is that they block global platelet activation, thereby indiscriminately preventing platelet function in hemostasis and thrombosis. Here, we identify an approach with the potential to overcome this limitation by preventing platelet function independently of canonical platelet activation and in a manner that appears specifically relevant in the setting of thrombosis. Genetic or pharmacological targeting of the class II phosphoinositide 3-kinase (PI3KC2α) dilates the internal membrane reserve of platelets but does not affect activation-dependent platelet function in standard tests. Despite this, inhibition of PI3KC2α is potently antithrombotic in human blood ex vivo and mice in vivo and does not affect hemostasis. Mechanistic studies reveal this antithrombotic effect to be the result of impaired platelet adhesion driven by pronounced hemodynamic shear stress gradients. These findings demonstrate an important role for PI3KC2α in regulating platelet structure and function via a membrane-dependent mechanism and suggest that drugs targeting the platelet internal membrane may be a suitable approach for antithrombotic therapies with an improved therapeutic window.
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Affiliation(s)
- Maria V Selvadurai
- Australian Centre for Blood Diseases, Monash University, Melbourne, VIC 3004, Australia
| | - Mitchell J Moon
- Australian Centre for Blood Diseases, Monash University, Melbourne, VIC 3004, Australia
| | - Simon J Mountford
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
| | - Xiao Ma
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
| | - Zhaohua Zheng
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
| | - Ian G Jennings
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
| | - Natasha M Setiabakti
- Australian Centre for Blood Diseases, Monash University, Melbourne, VIC 3004, Australia.,Faculty of Medicine, Universitas Indonesia, Salemba, Jakarta 10430, Indonesia
| | - Rizani P Iman
- Australian Centre for Blood Diseases, Monash University, Melbourne, VIC 3004, Australia.,Faculty of Medicine, Universitas Indonesia, Salemba, Jakarta 10430, Indonesia
| | - Rose J Brazilek
- Australian Centre for Blood Diseases, Monash University, Melbourne, VIC 3004, Australia
| | - Nurul Aisha Z Abidin
- Australian Centre for Blood Diseases, Monash University, Melbourne, VIC 3004, Australia
| | - Gaëtan Chicanne
- Institut des Maladies Métaboliques et Cardiovasculaires, Inserm U1048, Université Toulouse III, 31432 Toulouse CEDEX 4, France
| | - Sonia Severin
- Institut des Maladies Métaboliques et Cardiovasculaires, Inserm U1048, Université Toulouse III, 31432 Toulouse CEDEX 4, France
| | - Alyce J Nicholls
- Centre for Inflammatory Diseases, Department of Medicine, Monash Medical Centre, Monash University, Clayton, VIC 3800, Australia
| | - Connie H Y Wong
- Centre for Inflammatory Diseases, Department of Medicine, Monash Medical Centre, Monash University, Clayton, VIC 3800, Australia
| | - Jean-Yves Rinckel
- Université de Strasbourg, INSERM, EFS Grand Est, BPPS UMR-S 1255, FMTS, F-67000 Strasbourg, France
| | - Anita Eckly
- Université de Strasbourg, INSERM, EFS Grand Est, BPPS UMR-S 1255, FMTS, F-67000 Strasbourg, France
| | - Christian Gachet
- Université de Strasbourg, INSERM, EFS Grand Est, BPPS UMR-S 1255, FMTS, F-67000 Strasbourg, France
| | - Warwick S Nesbitt
- Australian Centre for Blood Diseases, Monash University, Melbourne, VIC 3004, Australia.,Microplatforms Research Group, School of Engineering, RMIT University, Melbourne, VIC 3000, Australia
| | - Philip E Thompson
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
| | - Justin R Hamilton
- Australian Centre for Blood Diseases, Monash University, Melbourne, VIC 3004, Australia.
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7
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Shen S, Prame Kumar K, Wen SW, Shim R, Wanrooy BJ, Stanley D, Moore RJ, Van TTH, Robert R, Hickey MJ, Wong CHY. Deficiency of Dietary Fiber Modulates Gut Microbiota Composition, Neutrophil Recruitment and Worsens Experimental Colitis. Front Immunol 2021; 12:619366. [PMID: 33708211 PMCID: PMC7940676 DOI: 10.3389/fimmu.2021.619366] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 01/18/2021] [Indexed: 12/14/2022] Open
Abstract
Ulcerative colitis is an inflammatory disease of the colon that is associated with colonic neutrophil accumulation. Recent evidence indicates that diet alters the composition of the gut microbiota and influences host–pathogen interactions. Specifically, bacterial fermentation of dietary fiber produces metabolites called short-chain fatty acids (SCFAs), which have been shown to protect against various inflammatory diseases. However, the effect of fiber deficiency on the key initial steps of inflammation, such as leukocyte–endothelial cell interactions, is unknown. Moreover, the impact of fiber deficiency on neutrophil recruitment under basal conditions and during inflammation in vivo is unknown. Herein, we hypothesized that a fiber-deficient diet promotes an inflammatory state in the colon at baseline and predisposes the host to more severe colitis pathology. Mice fed a no-fiber diet for 14 days showed significant changes in the gut microbiota and exhibited increased neutrophil-endothelial interactions in the colonic microvasculature. Although mice fed a no-fiber diet alone did not have observable colitis-associated symptoms, these animals were highly susceptible to low dose (0.5%) dextran sodium sulphate (DSS)-induced model of colitis. Supplementation of the most abundant SCFA, acetate, prevented no-fiber diet-mediated enrichment of colonic neutrophils and colitis pathology. Therefore, dietary fiber, possibly through the actions of acetate, plays an important role in regulating neutrophil recruitment and host protection against inflammatory colonic damage in an experimental model of colitis.
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Affiliation(s)
- Sj Shen
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences at Monash Health, Monash Medical Centre, Monash University, Clayton, VIC, Australia
| | - Kathryn Prame Kumar
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences at Monash Health, Monash Medical Centre, Monash University, Clayton, VIC, Australia
| | - Shu Wen Wen
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences at Monash Health, Monash Medical Centre, Monash University, Clayton, VIC, Australia
| | - Raymond Shim
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences at Monash Health, Monash Medical Centre, Monash University, Clayton, VIC, Australia
| | - Brooke J Wanrooy
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences at Monash Health, Monash Medical Centre, Monash University, Clayton, VIC, Australia
| | - Dragana Stanley
- School of Health Medical and Applied Sciences, Central Queensland University, Rockhamptom, QLD, Australia
| | - Robert J Moore
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, VIC, Australia.,School of Science, Royal Melbourne Institute of Technology (RMIT) University, Melbourne, VIC, Australia
| | - Thi Thu Hao Van
- School of Science, Royal Melbourne Institute of Technology (RMIT) University, Melbourne, VIC, Australia
| | - Remy Robert
- Monash Biomedicine Discovery Institute and Department of Physiology, Monash University, Clayton, VIC, Australia
| | - Michael J Hickey
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences at Monash Health, Monash Medical Centre, Monash University, Clayton, VIC, Australia
| | - Connie H Y Wong
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences at Monash Health, Monash Medical Centre, Monash University, Clayton, VIC, Australia
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8
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Lao XQ, Lau APS, Wong CHY, Yu TSI. Traffic-related air pollution and Hong Kong school children: abridged secondary publication. Hong Kong Med J 2020; 26 Suppl 6:6-9. [PMID: 33229594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023] Open
Affiliation(s)
- X Q Lao
- JC School of Public Health and Primary Care, The Chinese University of Hong Kong
| | - A P S Lau
- Division of Environment, Hong Kong University of Science and Technology
| | - C H Y Wong
- JC School of Public Health and Primary Care, The Chinese University of Hong Kong
- Environment Protection Department, Hong Kong
| | - T S I Yu
- JC School of Public Health and Primary Care, The Chinese University of Hong Kong
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9
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Wong CHY, Jenne CN, Kolaczkowska E. Editorial: Intravital Microscopy Imaging of Leukocytes. Front Immunol 2020; 11:2137. [PMID: 33013902 PMCID: PMC7511581 DOI: 10.3389/fimmu.2020.02137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 08/06/2020] [Indexed: 11/13/2022] Open
Affiliation(s)
- Connie H Y Wong
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences at Monash Health, Monash University, Clayton, VIC, Australia
| | - Craig N Jenne
- Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, Calgary, AB, Canada
| | - Elzbieta Kolaczkowska
- Department of Experimental Hematology, Institute of Zoology and Biomedical Research, Jagiellonian University, Krakow, Poland
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10
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Sun M, Brady RD, Wanrooy B, Mychasiuk R, Yamakawa GR, Casillas-Espinosa PM, Wong CHY, Shultz SR, McDonald SJ. Experimental traumatic brain injury does not lead to lung infection. J Neuroimmunol 2020; 343:577239. [PMID: 32302792 DOI: 10.1016/j.jneuroim.2020.577239] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 03/23/2020] [Accepted: 04/08/2020] [Indexed: 12/13/2022]
Abstract
Traumatic brain injury (TBI) patients often experience post-traumatic infections, especially in the lung. Pulmonary infection is associated with unfavorable outcomes and increased mortality rates in TBI patients; however, our understanding of the underlying mechanisms is poor. Here we used a lateral fluid percussion injury (LFPI) model in rats to investigate whether TBI could lead to spontaneous lung infection. Analysis of bacterial load in lung tissue indicated no occurrence of spontaneous lung infection at 24 h, 48 h, and 7 d following LFPI. This may suggest that exogenous infectious agents play a crucial role in post-TBI infection in patients.
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Affiliation(s)
- Mujun Sun
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC 3004, Australia.
| | - Rhys D Brady
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC 3004, Australia; Department of Medicine, The University of Melbourne, Melbourne, VIC 3052, Australia.
| | - Brooke Wanrooy
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences, Monash University, Melbourne, VIC 3168, Australia.
| | - Richelle Mychasiuk
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC 3004, Australia.
| | - Glenn R Yamakawa
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC 3004, Australia.
| | - Pablo M Casillas-Espinosa
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC 3004, Australia; Department of Medicine, The University of Melbourne, Melbourne, VIC 3052, Australia.
| | - Connie H Y Wong
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences, Monash University, Melbourne, VIC 3168, Australia.
| | - Sandy R Shultz
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC 3004, Australia; Department of Medicine, The University of Melbourne, Melbourne, VIC 3052, Australia.
| | - Stuart J McDonald
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC 3004, Australia; Department of Physiology, Anatomy and Microbiology, School of Life Sciences, La Trobe University, Melbourne, VIC 3086, Australia.
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11
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Shim R, Wen SW, Wanrooy BJ, Rank M, Thirugnanachandran T, Ho L, Sepehrizadeh T, de Veer M, Srikanth VK, Ma H, Phan TG, Sobey CG, Wong CHY. Stroke Severity, and Not Cerebral Infarct Location, Increases the Risk of Infection. Transl Stroke Res 2019; 11:387-401. [PMID: 31709500 DOI: 10.1007/s12975-019-00738-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2019] [Revised: 09/09/2019] [Accepted: 09/10/2019] [Indexed: 12/16/2022]
Abstract
Infection is a leading cause of death in patients with stroke; however, the impact of cerebral infarct size or location on infectious outcome is unclear. To examine the effect of infarct size on post-stroke infection, we utilised the intraluminal middle-cerebral artery occlusion (MCAO) mouse model of ischemic stroke and adjusted the duration of arterial occlusion. At 1 day following stroke onset, the proportion of mice with infection was significantly greater in mice that had larger infarct sizes. Additionally, the presence of lung infection in these mice with severe strokes extended past 2 days, suggestive of long-term immune impairment. At the acute phase, our data demonstrated an inverse relationship between infarct volume and the number of circulating leukocytes, indicating the elevated risk of infection in more severe stroke is associated with reduced cellularity in peripheral blood, owing predominately to markedly decreased lymphocyte numbers. In addition, the stroke-induced reduction of lymphocyte-to-neutrophil ratio was also evident in the lung of all post-stroke animals. To investigate the effect of infarct location on post-stroke infection, we additionally performed a photothrombotic (PT) model of stroke and using an innovative systematic approach of analysis, we found the location of cerebral infarct does not impact on the susceptibility of post-stroke infection, confirming the greater role of infarct volume over infarct location in the susceptibility to infection. Our experimental findings were validated in a clinical setting and reinforced that stroke severity, and not infarct location, influences the risk of infection after stroke.
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Affiliation(s)
- Raymond Shim
- Centre for Inflammatory Diseases, Department of Medicine at Monash Health, School of Clinical Sciences, Monash Medical Centre, Monash University, Clayton, VIC, 3168, Australia
| | - Shu Wen Wen
- Centre for Inflammatory Diseases, Department of Medicine at Monash Health, School of Clinical Sciences, Monash Medical Centre, Monash University, Clayton, VIC, 3168, Australia
| | - Brooke J Wanrooy
- Centre for Inflammatory Diseases, Department of Medicine at Monash Health, School of Clinical Sciences, Monash Medical Centre, Monash University, Clayton, VIC, 3168, Australia
| | - Michelle Rank
- Department of Anatomy and Neuroscience, School of Biomedical Sciences, The University of Melbourne, Parkville, Victoria, Australia
- School of Health and Biomedical Sciences, RMIT University, Bundoora, Victoria, Australia
| | - Tharani Thirugnanachandran
- Stroke and Ageing Research Group, Department of Medicine at Monash Health, School of Clinical Sciences, Monash Medical Centre, Monash University, Clayton, Victoria, Australia
| | - Luke Ho
- Centre for Inflammatory Diseases, Department of Medicine at Monash Health, School of Clinical Sciences, Monash Medical Centre, Monash University, Clayton, VIC, 3168, Australia
- Department of Medicine (Academic Unit), Peninsula Clinical School, Central Clinical School, Monash University, Frankston, Victoria, Australia
| | - Tara Sepehrizadeh
- Monash Biomedical Imaging, Monash University, Clayton, Victoria, Australia
| | - Michael de Veer
- Monash Biomedical Imaging, Monash University, Clayton, Victoria, Australia
| | - Velandai K Srikanth
- Department of Medicine (Academic Unit), Peninsula Clinical School, Central Clinical School, Monash University, Frankston, Victoria, Australia
| | - Henry Ma
- Stroke and Ageing Research Group, Department of Medicine at Monash Health, School of Clinical Sciences, Monash Medical Centre, Monash University, Clayton, Victoria, Australia
| | - Thanh G Phan
- Stroke and Ageing Research Group, Department of Medicine at Monash Health, School of Clinical Sciences, Monash Medical Centre, Monash University, Clayton, Victoria, Australia
| | - Christopher G Sobey
- Department of Physiology, Anatomy and Microbiology, School of Life Sciences, La Trobe University, Bundoora, Victoria, Australia
| | - Connie H Y Wong
- Centre for Inflammatory Diseases, Department of Medicine at Monash Health, School of Clinical Sciences, Monash Medical Centre, Monash University, Clayton, VIC, 3168, Australia.
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12
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13
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Wen SW, Shim R, Ho L, Wanrooy BJ, Srikhanta YN, Prame Kumar K, Nicholls AJ, Shen SJ, Sepehrizadeh T, Veer M, Srikanth VK, Ma H, Phan TG, Lyras D, Wong CHY. Advanced age promotes colonic dysfunction and gut-derived lung infection after stroke. Aging Cell 2019; 18:e12980. [PMID: 31199577 PMCID: PMC6718525 DOI: 10.1111/acel.12980] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 04/16/2019] [Accepted: 05/12/2019] [Indexed: 12/15/2022] Open
Abstract
Bacterial infection a leading cause of death among patients with stroke, with elderly patients often presenting with more debilitating outcomes. The findings from our retrospective study, supported by previous clinical reports, showed that increasing age is an early predictor for developing fatal infectious complications after stroke. However, exactly how and why older individuals are more susceptible to infection after stroke remains unclear. Using a mouse model of transient ischaemic stroke, we demonstrate that older mice (>12 months) present with greater spontaneous bacterial lung infections compared to their younger counterparts (7–10 weeks) after stroke. Importantly, we provide evidence that older poststroke mice exhibited elevated intestinal inflammation and disruption in gut barriers critical in maintaining colonic integrity following stroke, including reduced expression of mucin and tight junction proteins. In addition, our data support the notion that the localized pro‐inflammatory microenvironment driven by increased tumour necrosis factor‐α production in the colon of older mice facilitates the translocation and dissemination of orally inoculated bacteria to the lung following stroke onset. Therefore, findings of this study demonstrate that exacerbated dysfunction of the intestinal barrier in advanced age promotes translocation of gut‐derived bacteria and contributes to the increased risk to poststroke bacterial infection.
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Affiliation(s)
- Shu Wen Wen
- Department of Medicine, Centre for Inflammatory Diseases, School of Clinical Sciences Monash University Clayton Victoria Australia
| | - Raymond Shim
- Department of Medicine, Centre for Inflammatory Diseases, School of Clinical Sciences Monash University Clayton Victoria Australia
| | - Luke Ho
- Department of Medicine, Centre for Inflammatory Diseases, School of Clinical Sciences Monash University Clayton Victoria Australia
- Department of Medicine (Academic Unit), Peninsula Clinical School, Central Clinical School Monash University Frankston Victoria Australia
| | - Brooke J. Wanrooy
- Department of Medicine, Centre for Inflammatory Diseases, School of Clinical Sciences Monash University Clayton Victoria Australia
| | - Yogitha N. Srikhanta
- Department of Microbiology, Monash Biomedicine Discovery Institute Monash University Clayton Victoria Australia
| | - Kathryn Prame Kumar
- Department of Medicine, Centre for Inflammatory Diseases, School of Clinical Sciences Monash University Clayton Victoria Australia
| | - Alyce J. Nicholls
- Department of Medicine, Centre for Inflammatory Diseases, School of Clinical Sciences Monash University Clayton Victoria Australia
| | - SJ. Shen
- Department of Medicine, Centre for Inflammatory Diseases, School of Clinical Sciences Monash University Clayton Victoria Australia
| | - Tara Sepehrizadeh
- Monash Biomedical Imaging Monash University Clayton Victoria Australia
| | - Michael Veer
- Monash Biomedical Imaging Monash University Clayton Victoria Australia
| | - Velandai K. Srikanth
- Department of Medicine (Academic Unit), Peninsula Clinical School, Central Clinical School Monash University Frankston Victoria Australia
| | - Henry Ma
- Stroke and Ageing Research Group, Department of Medicine, School of Clinical Sciences, Monash Medical Centre Monash University Clayton Victoria Australia
| | - Thanh G. Phan
- Stroke and Ageing Research Group, Department of Medicine, School of Clinical Sciences, Monash Medical Centre Monash University Clayton Victoria Australia
| | - Dena Lyras
- Department of Microbiology, Monash Biomedicine Discovery Institute Monash University Clayton Victoria Australia
| | - Connie H. Y. Wong
- Department of Medicine, Centre for Inflammatory Diseases, School of Clinical Sciences Monash University Clayton Victoria Australia
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14
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Al-Sharea A, Lee MKS, Whillas A, Michell DL, Shihata WA, Nicholls AJ, Cooney OD, Kraakman MJ, Veiga CB, Jefferis AM, Jackson K, Nagareddy PR, Lambert G, Wong CHY, Andrews KL, Head GA, Chin-Dusting J, Murphy AJ. Chronic sympathetic driven hypertension promotes atherosclerosis by enhancing hematopoiesis. Haematologica 2018; 104:456-467. [PMID: 30361420 PMCID: PMC6395347 DOI: 10.3324/haematol.2018.192898] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 10/22/2018] [Indexed: 01/16/2023] Open
Abstract
Hypertension is a major, independent risk factor for atherosclerotic cardiovascular disease. However, this pathology can arise through multiple pathways, which could influence vascular disease through distinct mechanisms. An overactive sympathetic nervous system is a dominant pathway that can precipitate in elevated blood pressure. We aimed to determine how the sympathetic nervous system directly promotes atherosclerosis in the setting of hypertension. We used a mouse model of sympathetic nervous system-driven hypertension on the atherosclerotic-prone apolipoprotein E-deficient background. When mice were placed on a western type diet for 16 weeks, we showed the evolution of unstable atherosclerotic lesions. Fortuitously, the changes in lesion composition were independent of endothelial dysfunction, allowing for the discovery of alternative mechanisms. With the use of flow cytometry and bone marrow imaging, we found that sympathetic activation caused deterioration of the hematopoietic stem and progenitor cell niche in the bone marrow, promoting the liberation of these cells into the circulation and extramedullary hematopoiesis in the spleen. Specifically, sympathetic activation reduced the abundance of key hematopoietic stem and progenitor cell niche cells, sinusoidal endothelial cells and osteoblasts. Additionally, sympathetic bone marrow activity prompted neutrophils to secrete proteases to cleave the hematopoietic stem and progenitor cell surface receptor CXCR4. All these effects could be reversed using the β-blocker propranolol during the feeding period. These findings suggest that elevated blood pressure driven by the sympathetic nervous system can influence mechanisms that modulate the hematopoietic system to promote atherosclerosis and contribute to cardiovascular events.
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Affiliation(s)
- Annas Al-Sharea
- Haematopoiesis and Leukocyte Biology Laboratory, Division of Immunometabolism, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia
| | - Man K S Lee
- Haematopoiesis and Leukocyte Biology Laboratory, Division of Immunometabolism, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia
| | - Alexandra Whillas
- Haematopoiesis and Leukocyte Biology Laboratory, Division of Immunometabolism, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia
| | - Danielle L Michell
- Haematopoiesis and Leukocyte Biology Laboratory, Division of Immunometabolism, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Waled A Shihata
- Haematopoiesis and Leukocyte Biology Laboratory, Division of Immunometabolism, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Department of Pharmacology, Monash University, Clayton, VIC, Australia
| | | | - Olivia D Cooney
- Haematopoiesis and Leukocyte Biology Laboratory, Division of Immunometabolism, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia
| | - Michael J Kraakman
- Haematopoiesis and Leukocyte Biology Laboratory, Division of Immunometabolism, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Naomi Berrie Diabetes Center and Department of Medicine, Columbia University, New York, NY, USA
| | - Camilla Bertuzzo Veiga
- Haematopoiesis and Leukocyte Biology Laboratory, Division of Immunometabolism, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia
| | | | - Kristy Jackson
- Neuropharmacology Laboratory, Division of Hypertension and Cardiac Disease, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia
| | | | - Gavin Lambert
- Human Neurotransmitters Laboratory, Division of Hypertension and Cardiac Disease, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Iverson Health Innovation Research Institute, Swinburne University of Technology, Hawthorn, VIC, Australia
| | | | - Karen L Andrews
- Department of Pharmacology, Monash University, Clayton, VIC, Australia
| | - Geoff A Head
- Neuropharmacology Laboratory, Division of Hypertension and Cardiac Disease, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia
| | - Jaye Chin-Dusting
- Department of Pharmacology, Monash University, Clayton, VIC, Australia
| | - Andrew J Murphy
- Haematopoiesis and Leukocyte Biology Laboratory, Division of Immunometabolism, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia .,Department of Immunology, Monash University, Melbourne, VIC, Australia
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15
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Wanrooy BJ, Kumar KP, Wen SW, Qin CX, Ritchie RH, Wong CHY. Distinct contributions of hyperglycemia and high-fat feeding in metabolic syndrome-induced neuroinflammation. J Neuroinflammation 2018; 15:293. [PMID: 30348168 PMCID: PMC6198529 DOI: 10.1186/s12974-018-1329-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 10/09/2018] [Indexed: 01/04/2023] Open
Abstract
Background High-fat feeding and hyperglycemia, key risk factors for the development of metabolic syndrome (MetS), are emerging to associate with increased risk of developing dementia and cognitive decline. Despite this, clinical and experimental studies have yet to elucidate the specific contributions of either high-fat feeding or hyperglycemia to potential neuroinflammatory components. In this study, we delineate these individual components of MetS in the development of neuroinflammation. Methods Male C57Bl/6 J adult mice were treated with either citrate vehicle (CIT) or streptozotocin (STZ; 55 mg/kg) 3, 5 and 7 days before commencement of either a normal or high-fat diet for 9 or 18 weeks. By creating separate models of high-fat feeding, STZ-induced hyperglycemia, as well as in combination, we were able to delineate the specific effects of a high-fat diet and hyperglycemia on the brain. Throughout the feeding regime, we measured the animals’ body weight and fasting blood glucose levels. At the experimental endpoint, we assessed plasma levels of insulin, glycated haemoglobin and performed glucose tolerance testing. In addition, we examined the effect of high fat-feeding and hyperglycemia on the levels of systemic inflammatory cytokines, gliosis in the hippocampus and immune infiltration in cerebral hemispheric tissue. Furthermore, we used intravital multiphoton microscopy to assess leukocyte-endothelial cell interactions in the cerebral vasculature of mice in vivo. Results We showed that acute hyperglycemia induces regional-specific effects on the brain by elevating microglial numbers and promotes astrocytosis in the hippocampus. In addition, we demonstrated that chronic hyperglycemia supported the recruitment of peripheral GR1+ granulocytes to the cerebral microvasculature in vivo. Moreover, we provided evidence that these changes were independent of the systemic inflammation associated with high-fat feeding. Conclusions Hyperglycemia alone preferentially induces microglial numbers and astrocytosis in the hippocampus and is associated with the peripheral recruitment of leukocytes to the cerebrovasculature, but not systemic inflammation. High-fat feeding alone, and in combination with hyperglycemia, increases the systemic pro-inflammatory cytokine milieu but does not result in brain-specific immune gliosis. These results shed light on the specific contributions of high-fat feeding and hyperglycemia as key factors of MetS in the development of neuroinflammation. Electronic supplementary material The online version of this article (10.1186/s12974-018-1329-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Brooke J Wanrooy
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences at Monash Health, Monash Medical Centre, Monash University, Clayton, VIC, 3168, Australia
| | - Kathryn Prame Kumar
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences at Monash Health, Monash Medical Centre, Monash University, Clayton, VIC, 3168, Australia
| | - Shu Wen Wen
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences at Monash Health, Monash Medical Centre, Monash University, Clayton, VIC, 3168, Australia
| | - Cheng Xue Qin
- Baker Heart and Diabetes Institute, Melbourne, Australia
| | - Rebecca H Ritchie
- Baker Heart and Diabetes Institute, Melbourne, Australia.,Department of Diabetes, Monash University, Melbourne, Australia
| | - Connie H Y Wong
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences at Monash Health, Monash Medical Centre, Monash University, Clayton, VIC, 3168, Australia.
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16
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Zeng Z, Surewaard BGJ, Wong CHY, Guettler C, Petri B, Burkhard R, Wyss M, Le Moual H, Devinney R, Thompson GC, Blackwood J, Joffe AR, McCoy KD, Jenne CN, Kubes P. Sex-hormone-driven innate antibodies protect females and infants against EPEC infection. Nat Immunol 2018; 19:1100-1111. [DOI: 10.1038/s41590-018-0211-2] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Accepted: 08/20/2018] [Indexed: 12/21/2022]
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17
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Abstract
Our aging population is set to grow considerably in the coming decades. In fact, the number of individuals older than 65 years will double by 2050. This projected increase in people living with extended life expectancy represents an inevitable upsurge in the presentation of age-related pathologies. However, our current understanding of the impact of aging on a number of biological processes is unfortunately inadequate. Cardiovascular, cerebrovascular, and neurodegenerative diseases are particularly prevalent in the elderly population. Intriguingly, these pathologies are all associated with vascular dysfunction, suggesting that the process of aging can induce structural and functional impairments in vascular networks. Together with elevated cell senescence, pre-existing comorbidities, and the emerging concept of age-associated inflammatory imbalance, impaired vascular functions can significantly increase one's risk in acquiring age-related diseases. In this short review, we highlight some current clinical and experimental evidence of how biological aging contributes to three vascular-associated pathologies: atherosclerosis, stroke, and Alzheimer's disease.
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Affiliation(s)
- Shu Wen Wen
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences, Monash University, Clayton, Vic., Australia
| | - Connie H Y Wong
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences, Monash University, Clayton, Vic., Australia
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18
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Shen S, Prame Kumar K, Stanley D, Moore RJ, Van TTH, Wen SW, Hickey MJ, Wong CHY. Invariant Natural Killer T Cells Shape the Gut Microbiota and Regulate Neutrophil Recruitment and Function During Intestinal Inflammation. Front Immunol 2018; 9:999. [PMID: 29867976 PMCID: PMC5949322 DOI: 10.3389/fimmu.2018.00999] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Accepted: 04/23/2018] [Indexed: 12/16/2022] Open
Abstract
Invariant natural killer T (iNKT) cells and neutrophils play an increasingly important part in the pathogenesis of inflammatory diseases, but their precise roles in modulating colitis remain unclear. Previous studies have shown important interplays between host immune system and the gut microbiota, and the resulting modulation of inflammation. However, the interactions between iNKT cells, neutrophil and gut microbiota in regulating colitis pathology are poorly understood. Here, we show iNKT cell-deficient Jα18−/− mice display reduced dextran sodium sulfate (DSS)-induced colonic inflammation compared to their wild-type (WT) counterparts. We reveal that there is a distinct gut microbiota shaped by the absence of iNKT cells, which comprises of microorganisms that are associated with protection from colonic inflammation. Additionally, the reduced inflammation in Jα18−/− mice was correlated with increased expressions of neutrophil chemoattractant (Cxcl1 and Cxcl2) and increased neutrophil recruitment. However, these neutrophils were recruited to the colon at day 3 of our model, prior to observable clinical signs at day 5. Further analysis shows that these neutrophils, primed by the microbiota shaped by the lack of iNKT cells, exhibit anti-inflammatory and immune-modulatory properties. Indeed, depletion of neutrophils in DSS-treated Jα18−/− mice demonstrates that neutrophils confer an anti-colitogenic effect in the absence of iNKT cells. Thus, our data supports a changing dogma that neutrophils possess important regulatory roles in inflammation and highlights the complexity of the iNKT cell–microbiota–neutrophil axis in regulating colonic inflammation.
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Affiliation(s)
- Sj Shen
- Centre for Inflammatory Diseases, Monash University Department of Medicine, Monash Medical Centre, Clayton, VIC, Australia
| | - Kathryn Prame Kumar
- Centre for Inflammatory Diseases, Monash University Department of Medicine, Monash Medical Centre, Clayton, VIC, Australia
| | - Dragana Stanley
- School of Health Medical and Applied Sciences, Central Queensland University, Rockhampton, QLD, Australia
| | - Robert J Moore
- Infection and Immunity Program, Department of Microbiology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, VIC, Australia.,School of Science, RMIT University, Melbourne, VIC, Australia
| | - Thi Thu Hao Van
- School of Science, RMIT University, Melbourne, VIC, Australia
| | - Shu Wen Wen
- Centre for Inflammatory Diseases, Monash University Department of Medicine, Monash Medical Centre, Clayton, VIC, Australia
| | - Michael J Hickey
- Centre for Inflammatory Diseases, Monash University Department of Medicine, Monash Medical Centre, Clayton, VIC, Australia
| | - Connie H Y Wong
- Centre for Inflammatory Diseases, Monash University Department of Medicine, Monash Medical Centre, Clayton, VIC, Australia
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19
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Shim R, Wong CHY. Complex interplay of multiple biological systems that contribute to post-stroke infections. Brain Behav Immun 2018; 70:10-20. [PMID: 29571897 DOI: 10.1016/j.bbi.2018.03.019] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 03/14/2018] [Accepted: 03/14/2018] [Indexed: 02/08/2023] Open
Abstract
Stroke is a leading contributor of death and disability around the world. Despite its recognised debilitating neurological deficits, a devastating clinical complication of surviving stroke patients that needs more attention is infection. Up to half of the patients develop infections after stroke, and a high proportion of them will die as a direct consequence. Major clinical trials that examined preventive antibiotic therapy in stroke patients have demonstrated this method of prevention is not effective as it does not reduce incidence of post-stroke pneumonia or improve patient outcome. Additionally, retrospective studies evaluating the use of β-blockers for the modulation of the sympathetic nervous system to prevent post-stroke infections have given mixed results. Therefore, there is an urgent need for more effective therapeutic options that target the underlying mechanisms of post-stroke infections. The understanding that infections are largely attributable to the "stroke-induced systemic immunosuppression" phenomenon has begun to emerge, and thus, exploring the pathways that trigger post-stroke immunosuppression is expected to reveal potential new therapeutics. As such, we will outline the impacts that stroke has on several biological systems in this review, and discuss how these contribute to host susceptibility to infection after stroke. Furthermore, the emerging role of the gut and its microbiota has recently come to surface and intensifies the complex pathways to post-stroke infection. Finally, we identify potential avenues to combat infection that target the pathways of stroke-induced systemic immunosuppression to ultimately improve stroke patient outcome.
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Affiliation(s)
- Raymond Shim
- Centre for Inflammatory Diseases, Department of Medicine, Monash Medical Centre, Monash University, Clayton, Victoria, Australia
| | - Connie H Y Wong
- Centre for Inflammatory Diseases, Department of Medicine, Monash Medical Centre, Monash University, Clayton, Victoria, Australia.
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20
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Abstract
Neutrophils are becoming recognized as highly versatile and sophisticated cells that display de novo synthetic capacity and potentially prolonged lifespan. Emerging concepts such as neutrophil heterogeneity and plasticity have revealed that, under pathological conditions, neutrophils may differentiate into discrete subsets defined by distinct phenotypic and functional characteristics. Indeed, these newly described neutrophil subsets will undoubtedly add to the already complex interactions between neutrophils and other immune cell types for an effective immune response. The interactions between neutrophils and monocytes/macrophages enable the host to efficiently defend against and eliminate foreign pathogens. However, it is also becoming increasingly clear that these interactions can be detrimental to the host if not tightly regulated. In this review, we will explore the functional cooperation of neutrophil and monocytes/macrophages in homeostasis, during acute inflammation and in various disease settings. We will discuss this in the context of cardiovascular disease in the form of atherosclerosis, an autoimmune disease mainly occurring in the kidneys, as well as the unique intestinal immune response of the gut that does not conform to the norms of the typical immune system.
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Affiliation(s)
- Kathryn Prame Kumar
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences, Monash Medical Centre, Monash University, Clayton, VIC, 3168, Australia
| | - Alyce J Nicholls
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences, Monash Medical Centre, Monash University, Clayton, VIC, 3168, Australia
| | - Connie H Y Wong
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences, Monash Medical Centre, Monash University, Clayton, VIC, 3168, Australia.
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21
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Abstract
Recent work from our laboratory has provided evidence that indicates selective bacterial translocation from the host gut microbiota to peripheral tissues (i.e. lung) plays a key role in the development of post-stroke infections. Despite this, it is currently unknown whether mucosal bacteria that live on and interact closely with the host intestinal epithelium contribute in regulating bacterial translocation after stroke. Here, we found that the microbial communities within the mucosa of gastrointestinal tract (GIT) were significantly different between sham-operated and post-stroke mice at 24 h following surgery. The differences in microbiota composition were substantial in all sections of the GIT and were significant, even at the phylum level. The main characteristics of the stroke-induced shift in mucosal microbiota composition were an increased abundance of Akkermansia muciniphila and an excessive abundance of clostridial species. Furthermore, we analysed the predicted functional potential of the altered mucosal microbiota induced by stroke using PICRUSt and revealed significant increases in functions associated with infectious diseases, membrane transport and xenobiotic degradation. Our findings revealed stroke induces far-reaching and robust changes to the intestinal mucosal microbiota. A better understanding of the precise molecular events leading up to stroke-induced mucosal microbiota changes may represent novel therapy targets to improve patient outcomes.
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Affiliation(s)
- Dragana Stanley
- School of Health Medical and Applied Sciences, Central Queensland University, Bruce Highway, Rockhampton, Queensland, 4702, Australia
| | - Robert J Moore
- School of Science, RMIT University, Bundoora, Victoria, 3083, Australia.,Infection and Immunity Program, Biomedicine Discovery Institute, Department of Microbiology, Monash University, Clayton, Victoria, 3800, Australia
| | - Connie H Y Wong
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences, Monash University, Clayton, Victoria, 3168, Australia.
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22
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Nicholls AJ, Wen SW, Hall P, Hickey MJ, Wong CHY. Activation of the sympathetic nervous system modulates neutrophil function. J Leukoc Biol 2017; 103:295-309. [PMID: 29345350 PMCID: PMC6635748 DOI: 10.1002/jlb.3ma0517-194rr] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Revised: 10/04/2017] [Accepted: 12/06/2017] [Indexed: 01/19/2023] Open
Abstract
Emerging evidence has revealed that noradrenaline (NA), the main neurotransmitter of the sympathetic nervous system (SNS), regulates a variety of immune functions via binding to adrenergic receptors present on immune cells. In this study, we examined the role of NA in the regulation of neutrophil functions. Neutrophils were isolated from the bone marrow of naïve mice and treated with NA at various concentrations to assess the effect on various neutrophil functions. Additionally, we performed cremaster intravital microscopy to examine neutrophil‐endothelial cell interactions following NA superfusion in vivo. In a separate group of animals, mice were subjected to an experimental model of stroke and at 4 and 24 h neutrophils were isolated for assessment on their ability to migrate toward various chemokines. Treatment of neutrophils with NA for 4 h significantly impaired neutrophil chemotaxis and induced an N2 neutrophil phenotype with reduced expression of the genes critical for cytoskeleton remodeling and inflammation. Prolonged NA administration promoted neutrophils to release myeloperoxidase and IL‐6, but suppressed the production of interferon‐γ and IL‐10, reduced neutrophil activation and phagocytosis. Superfusion of NA over the cremaster muscle almost completely inhibited fMLP‐induced neutrophil adhesion/arrest and transmigration. Furthermore, using a mouse model of stroke, a pathological condition in which SNS activation is evident, neutrophils isolated from poststroke mice showed markedly reduced chemotaxis toward all of the chemokines tested. The findings from our study indicate that neutrophil chemotaxis, activation, and phagocytosis can all be negatively regulated in an NA‐dependent manner. A better understanding of the relationship between sympathetic activation and neutrophil function will be important for the development of effective antibacterial interventions.
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Affiliation(s)
- Alyce J Nicholls
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences at Monash Health, Monash University, Australia
| | - Shu Wen Wen
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences at Monash Health, Monash University, Australia
| | - Pam Hall
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences at Monash Health, Monash University, Australia
| | - Michael J Hickey
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences at Monash Health, Monash University, Australia
| | - Connie H Y Wong
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences at Monash Health, Monash University, Australia
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Abstract
Microbiota research, in particular that of the gut, has recently gained much attention in medical research owing to technological advances in metagenomics and metabolomics. Despite this, much of the research direction has focused on long-term or chronic effects of microbiota manipulation on health and disease. In this addendum, we reflect on our recent publication that reported findings addressing a rather unconventional hypothesis. Bacterial pneumonia is highly prevalent and is one of the leading contributors to stroke morbidity and mortality worldwide. However, microbiological cultures of samples taken from stroke patient with a suspected case of pneumonia often return with a negative result. Therefore, we proposed that post-stroke infection may be due to the presence of anaerobic bacteria, possibly those originated from the host gut microbiota. Supporting this, we showed that stroke promotes intestinal barrier breakdown and robust microbiota changes, and the subsequent translocation of selective bacterial strain from the host gut microbiota to peripheral tissues (i.e. lung) induces post-stroke infections. Our findings were further supported by various elegant studies published in the past 12 months. Here, we discuss and provide an overview of our key findings, supporting studies, and the implications for future advances in stroke research.
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Affiliation(s)
- Shu Wen Wen
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences, Monash University, Clayton, Victoria, Australia
| | - Connie H. Y. Wong
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences, Monash University, Clayton, Victoria, Australia,CONTACT Connie H. Y. Wong, PhD. , Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences, Monash Medical Centre, Monash University, Clayton, VIC 3168 Australia
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Zhang M, Downes CE, Wong CHY, Brody KM, Guio-Agulair PL, Gould J, Ates R, Hertzog PJ, Taylor JM, Crack PJ. Type-I interferon signalling through IFNAR1 plays a deleterious role in the outcome after stroke. Neurochem Int 2017. [PMID: 28647375 DOI: 10.1016/j.neuint.2017.06.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Neuroinflammation contributes significantly to the pathophysiology of stroke. Here we test the hypothesis that the type I interferon receptor (IFNAR1) plays a critical role in neural injury after stroke by regulating the resultant pro-inflammatory environment. Wild-type and IFNAR1-/- primary murine neurons and glia were exposed to oxygen glucose deprivation (OGD) and cell viability was assessed. Transient cerebral ischemia/reperfusion injury was induced by mid-cerebral artery occlusion (MCAO) in wild-type and IFNAR1-/- and IFNAR2-/- mice in vivo, and infarct size, and molecular parameters measured. To block IFNAR1 signalling, wild-type mice were treated with a blocking monoclonal antibody directed to IFNAR1 (MAR-1) and MCAO was performed. Quantitative PCR confirmed MCAO in wild-type mice induced a robust type-I interferon gene regulatory signature. Primary cultured IFNAR1-deficient neurons were found to be protected from cell death when exposed to OGD in contrast to primary cultured IFNAR1-deficient glial cells. IFNAR1-/- mice demonstrated a decreased infarct size (24.9 ± 7.1 mm3 n = 8) compared to wild-type controls (65.1 ± 4.8 mm3 n = 8). Western blot and immunohistochemistry showed alterations in Akt and Stat-3 phosphorylation profiles in the IFNAR1-/- brain. MAR-1 injection into WT mice (i.v. 0.5 mg 60 min prior to MCAO) resulted in a 60% decrease in infarct size when compared to the IgG control. IFNAR2-/- mice failed to display the neuroprotective phenotype seen in IFNAR1-/- mice after MCAO. Our data proposes that central nervous system signalling through IFNAR1 is a previously unrecognised factor that is critical to neural injury after stroke.
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Affiliation(s)
- Moses Zhang
- Department of Pharmacology and Therapeutics, The University of Melbourne, Parkville, Australia
| | - Catherine E Downes
- Department of Pharmacology and Therapeutics, The University of Melbourne, Parkville, Australia
| | - Connie H Y Wong
- Centre for Inflammatory Diseases, Monash University, Clayton, Australia
| | - Kate M Brody
- Department of Pharmacology and Therapeutics, The University of Melbourne, Parkville, Australia
| | - Pedro L Guio-Agulair
- Department of Pharmacology and Therapeutics, The University of Melbourne, Parkville, Australia
| | - Jodee Gould
- Hudson Institute of Medical Research, Clayton, Australia
| | - Robert Ates
- Department of Pharmacology and Therapeutics, The University of Melbourne, Parkville, Australia
| | - Paul J Hertzog
- Hudson Institute of Medical Research, Clayton, Australia
| | - Juliet M Taylor
- Department of Pharmacology and Therapeutics, The University of Melbourne, Parkville, Australia
| | - Peter J Crack
- Department of Pharmacology and Therapeutics, The University of Melbourne, Parkville, Australia.
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Wong CHY, Jenne CN, Tam PP, Léger C, Venegas A, Ryckborst K, Hill MD, Kubes P. Prolonged Activation of Invariant Natural Killer T Cells and T H2-Skewed Immunity in Stroke Patients. Front Neurol 2017; 8:6. [PMID: 28154551 PMCID: PMC5244395 DOI: 10.3389/fneur.2017.00006] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Accepted: 01/05/2017] [Indexed: 01/09/2023] Open
Abstract
Background Infection is highly prevalent and contribute significantly to mortality of stroke patients. In addition to the well described robust systemic lymphocytopenia and skewed T helper 2 (TH2)-immunity after stroke, emerging experimental evidence demonstrate that the development of infection poststroke is attributed by the activation of invariant natural killer T (iNKT) cells. In this prospective study, we examined the levels of a broad spectrum of inflammatory mediators, the activation status of iNKT cell in the blood of patients with various degree of stroke severity, and investigate whether these parameters differ in patients who later develop poststroke infections. Methods and results We obtained blood from stroke patients and matching controls to perform flow cytometry and multiplex measurement of inflammatory mediators. Our data suggest a pronounced activation of iNKT cells in stroke patients as compared with matched Healthy and Hospital control patients. The magnitude of iNKT activation is positively correlated with the severity of stroke, supporting the hypothesis that iNKT cells may contribute in the modulation of the host immune response after stroke-associated brain injury. In addition, stroke severity is closely correlated with decreased TH1/TH2 ratio, increased production of interleukin (IL)-10, with infected stroke patients showing exacerbated production of IL-10. Conclusion Stroke triggers a robust and sustained shift in systemic immunity in patients, including specific lymphopenia, robust activation of iNKT cells, systemic production of IL-10, and a prolonged TH2-skewed immunity, all are potential contributors to severe immune suppression seen in patients after stroke. Future studies with large sample size will provide potential causality relationship insights.
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Affiliation(s)
- Connie H Y Wong
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Science, Monash University, Melbourne, VIC, Australia; Department of Physiology and Pharmacology, Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AB, Canada
| | - Craig N Jenne
- Department of Physiology and Pharmacology, Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AB, Canada; Department of Critical Care, Snyder Institute for Critical Care, University of Calgary, Calgary, AB, Canada
| | - Patrick P Tam
- Department of Critical Care, Snyder Institute for Critical Care, University of Calgary , Calgary, AB , Canada
| | - Caroline Léger
- Department of Critical Care, Snyder Institute for Critical Care, University of Calgary , Calgary, AB , Canada
| | - Andres Venegas
- Stroke Unit, Department of Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary , Calgary, AB , Canada
| | - Karla Ryckborst
- Stroke Unit, Department of Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary , Calgary, AB , Canada
| | - Michael D Hill
- Stroke Unit, Department of Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary , Calgary, AB , Canada
| | - Paul Kubes
- Department of Physiology and Pharmacology, Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AB, Canada; Department of Critical Care, Snyder Institute for Critical Care, University of Calgary, Calgary, AB, Canada
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Stanley D, Mason LJ, Mackin KE, Srikhanta YN, Lyras D, Prakash MD, Nurgali K, Venegas A, Hill MD, Moore RJ, Wong CHY. Translocation and dissemination of commensal bacteria in post-stroke infection. Nat Med 2016; 22:1277-1284. [DOI: 10.1038/nm.4194] [Citation(s) in RCA: 215] [Impact Index Per Article: 26.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 09/01/2016] [Indexed: 12/13/2022]
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Kamp ME, Shim R, Nicholls AJ, Oliveira AC, Mason LJ, Binge L, Mackay CR, Wong CHY. G Protein-Coupled Receptor 43 Modulates Neutrophil Recruitment during Acute Inflammation. PLoS One 2016; 11:e0163750. [PMID: 27658303 PMCID: PMC5033414 DOI: 10.1371/journal.pone.0163750] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 09/13/2016] [Indexed: 12/14/2022] Open
Abstract
Fermentation of dietary fibre in the gut yields large amounts of short chain fatty acids (SCFAs). SCFAs can impart biological responses in cells through their engagement of ‘metabolite-sensing’ G protein-coupled receptors (GPCRs). One of the main SCFA receptors, GPR43, is highly expressed by neutrophils, which suggests that the actions of GPR43 and dietary fibre intake may affect neutrophil recruitment during inflammatory responses in vivo. Using intravital imaging of the small intestine, we found greater intravascular neutrophil rolling and adhesion in Gpr43−/−mice in response to LPS at 1 h. After 4 h of LPS challenge, the intravascular rolling velocity of GPR43-deficient neutrophils was reduced significantly and increased numbers of neutrophils were found in the lamina propria of Gpr43−/−mice. Additionally, GPR43-deficient leukocytes demonstrated exacerbated migration into the peritoneal cavity following fMLP challenge. The fMLP-induced neutrophil migration was significantly suppressed in wildtype mice that were treated with acetate, but not in Gpr43−/−mice, strongly suggesting a role for SCFAs in modulating neutrophil migration via GPR43. Indeed, neutrophils of no fibre-fed wildtype mice exhibited elevated migratory behaviour compared to normal chow-fed wildtype mice. Interestingly, this elevated migration could also be reproduced through simple transfer of a no fibre microbiota into germ-free mice, suggesting that the composition and function of microbiota stemming from a no fibre diet mediated the changes in neutrophil migration. Therefore, GPR43 and a microbiota composition that allows for SCFA production function to modulate neutrophil recruitment during inflammatory responses.
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Affiliation(s)
- Marjon E. Kamp
- School of Biomedical Sciences, Monash University, Victoria, Australia
| | - Raymond Shim
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences, Monash University, Victoria, Australia
| | - Alyce J. Nicholls
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences, Monash University, Victoria, Australia
| | - Ana Carolina Oliveira
- Laboratório de Imunologia Molecular, Instituto de Biofisica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Linda J. Mason
- School of Biomedical Sciences, Monash University, Victoria, Australia
| | - Lauren Binge
- School of Biomedical Sciences, Monash University, Victoria, Australia
| | - Charles R. Mackay
- School of Biomedical Sciences, Monash University, Victoria, Australia
| | - Connie H. Y. Wong
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences, Monash University, Victoria, Australia
- * E-mail:
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Chevalier N, Macia L, Tan JK, Mason LJ, Robert R, Thorburn AN, Wong CHY, Tsai LM, Bourne K, Brink R, Yu D, Mackay CR. The Role of Follicular Helper T Cell Molecules and Environmental Influences in Autoantibody Production and Progression to Inflammatory Arthritis in Mice. Arthritis Rheumatol 2016; 68:1026-38. [PMID: 26501485 DOI: 10.1002/art.39481] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Accepted: 10/22/2015] [Indexed: 01/17/2023]
Abstract
OBJECTIVE Antibody-mediated autoimmunity involves cognate interactions between self-reactive T cells and B cells during germinal center (GC) reactions. The aim of this study was to determine the role of essential follicular helper T (Tfh) cell molecules (CXCR5, signaling lymphocytic activation molecule-associated protein) on autoreactive CD4+ cells and the role of certain environmental influences that may determine GC-driven autoantibody production and arthritis development. METHODS We transferred self-reactive CD4+ cells from KRN-Tg mice into recipient mice, which induced autoantibodies and autoinflammatory arthritis. This model allowed manipulation of environmental effects, such as inflammation, and use of transferred cells that were genetically deficient in important Tfh cell-associated molecules. RESULTS A deficiency of signaling lymphocytic activation molecule-associated protein (SAP) in CD4+ cells from KRN-Tg mice completely protected against arthritis, indicating that stable T cell-B cell interactions are required for GC formation, autoantibody production, and arthritis induction. In contrast, a CXCR5 deficiency in CD4+ cells from KRN-Tg mice still induced disease when these cells were transferred into wild-type mice, suggesting that T cell help for B cells could rely on other migration mechanisms. However, various manipulations influenced this system, including elimination of bystander effects through use of CD28(-/-) recipient mice (reduced disease) or use of inflammation-inducing Freund's complete adjuvant (progression to arthritis). We also examined the capacity of preexisting GCs with a nonautoimmune specificity to co-opt autoimmune T cells and observed no evidence for any influence. CONCLUSION In addition to the quality and quantity of cognate CD4+ cell help, external factors such as inflammation and noncognate CD4+ cell bystander activation trigger autoimmunity by shaping events within autoimmune GC responses. SAP is an essential molecule for autoimmune antibody production, whereas the importance of CXCR5 varies depending on the circumstances.
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Affiliation(s)
- Nina Chevalier
- University Medical Centre Freiburg, Freiburg, Germany, Monash University, Clayton Campus, Melbourne, Victoria, Australia, and Garvan Institute of Medical Research, Sydney, New South Wales, Australia
| | - Laurence Macia
- Monash University, Clayton Campus, Melbourne, Victoria, Australia, and Charles Perkins Centre, University of Sydney, Camperdown, New South Wales, Australia
| | - Jian K Tan
- Monash University, Clayton Campus, Melbourne, Victoria, Australia
| | - Linda J Mason
- Monash University, Clayton Campus, Melbourne, Victoria, Australia
| | - Remy Robert
- Monash University, Clayton Campus, Melbourne, Victoria, Australia
| | | | - Connie H Y Wong
- Monash University, Clayton Campus, Melbourne, Victoria, Australia
| | - Louis M Tsai
- Monash University, Clayton Campus, Melbourne, Victoria, Australia
| | - Katherine Bourne
- Garvan Institute of Medical Research, Sydney, New South Wales, Australia
| | - Robert Brink
- Garvan Institute of Medical Research, Sydney, New South Wales, Australia
| | - Di Yu
- Monash University, Clayton Campus, Melbourne, Victoria, Australia
| | - Charles R Mackay
- Monash University, Clayton Campus, Melbourne, Victoria, Australia
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Shim R, Wong CHY. Ischemia, Immunosuppression and Infection--Tackling the Predicaments of Post-Stroke Complications. Int J Mol Sci 2016; 17:ijms17010064. [PMID: 26742037 PMCID: PMC4730309 DOI: 10.3390/ijms17010064] [Citation(s) in RCA: 103] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 12/14/2015] [Accepted: 12/24/2015] [Indexed: 12/29/2022] Open
Abstract
The incidence of stroke has risen over the past decade and will continue to be one of the leading causes of death and disability worldwide. While a large portion of immediate death following stroke is due to cerebral infarction and neurological complications, the most common medical complication in stroke patients is infection. In fact, infections, such as pneumonia and urinary tract infections, greatly worsen the clinical outcome of stroke patients. Recent evidence suggests that the disrupted interplay between the central nervous system and immune system contributes to the development of infection after stroke. The suppression of systemic immunity by the nervous system is thought to protect the brain from further inflammatory insult, yet this comes at the cost of increased susceptibility to infection after stroke. To improve patient outcome, there have been attempts to lessen the stroke-associated bacterial burden through the prophylactic use of broad-spectrum antibiotics. However, preventative antibiotic treatments have been unsuccessful, and therefore have been discouraged. Additionally, with the ever-rising obstacle of antibiotic-resistance, future therapeutic options to reverse immune impairment after stroke by augmentation of host immunity may be a viable alternative option. However, cautionary steps are required to ensure that collateral ischemic damage caused by cerebral inflammation remains minimal.
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Affiliation(s)
- Raymond Shim
- Centre for Inflammatory Diseases, Department of Medicine, Monash Medical Centre, Monash University, Clayton, VIC 3168, Australia.
| | - Connie H Y Wong
- Centre for Inflammatory Diseases, Department of Medicine, Monash Medical Centre, Monash University, Clayton, VIC 3168, Australia.
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30
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Thorburn AN, McKenzie CI, Shen S, Stanley D, Macia L, Mason LJ, Roberts LK, Wong CHY, Shim R, Robert R, Chevalier N, Tan JK, Mariño E, Moore RJ, Wong L, McConville MJ, Tull DL, Wood LG, Murphy VE, Mattes J, Gibson PG, Mackay CR. Evidence that asthma is a developmental origin disease influenced by maternal diet and bacterial metabolites. Nat Commun 2015; 6:7320. [PMID: 26102221 DOI: 10.1038/ncomms8320] [Citation(s) in RCA: 586] [Impact Index Per Article: 65.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Accepted: 04/27/2015] [Indexed: 12/27/2022] Open
Abstract
Asthma is prevalent in Western countries, and recent explanations have evoked the actions of the gut microbiota. Here we show that feeding mice a high-fibre diet yields a distinctive gut microbiota, which increases the levels of the short-chain fatty acid, acetate. High-fibre or acetate-feeding led to marked suppression of allergic airways disease (AAD, a model for human asthma), by enhancing T-regulatory cell numbers and function. Acetate increases acetylation at the Foxp3 promoter, likely through HDAC9 inhibition. Epigenetic effects of fibre/acetate in adult mice led us to examine the influence of maternal intake of fibre/acetate. High-fibre/acetate feeding of pregnant mice imparts on their adult offspring an inability to develop robust AAD. High fibre/acetate suppresses expression of certain genes in the mouse fetal lung linked to both human asthma and mouse AAD. Thus, diet acting on the gut microbiota profoundly influences airway responses, and may represent an approach to prevent asthma, including during pregnancy.
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Affiliation(s)
- Alison N Thorburn
- Department of Immunology, Monash University, Clayton, Victoria 3800, Australia
| | - Craig I McKenzie
- Department of Immunology, Monash University, Clayton, Victoria 3800, Australia
| | - Sj Shen
- Department of Immunology, Monash University, Clayton, Victoria 3800, Australia
| | - Dragana Stanley
- School of Medical and Applied Sciences, Central Queensland University, Rockhampton, Queensland 4702, Australia
| | - Laurence Macia
- Department of Immunology, Monash University, Clayton, Victoria 3800, Australia
| | - Linda J Mason
- Department of Immunology, Monash University, Clayton, Victoria 3800, Australia
| | - Laura K Roberts
- Department of Immunology, Monash University, Clayton, Victoria 3800, Australia
| | - Connie H Y Wong
- Department of Immunology, Monash University, Clayton, Victoria 3800, Australia
| | - Raymond Shim
- Department of Immunology, Monash University, Clayton, Victoria 3800, Australia
| | - Remy Robert
- Department of Immunology, Monash University, Clayton, Victoria 3800, Australia
| | - Nina Chevalier
- 1] Department of Immunology, Monash University, Clayton, Victoria 3800, Australia [2] Department of Rheumatology and Clinical Immunology, University Medical Center, 79106 Freiburg, Germany
| | - Jian K Tan
- Department of Immunology, Monash University, Clayton, Victoria 3800, Australia
| | - Eliana Mariño
- Department of Immunology, Monash University, Clayton, Victoria 3800, Australia
| | - Rob J Moore
- 1] CSIRO Animal, Food, and Health Sciences, Geelong, Victoria 3220, Australia [2] Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia
| | - Lee Wong
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia
| | - Malcolm J McConville
- 1] Department of Biochemistry and Molecular Biology, Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Melbourne, Victoria 3010, Australia [2] Metabolomics Australia, Bio21 Institute of Molecular Sciences and Biotechnology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Dedreia L Tull
- Metabolomics Australia, Bio21 Institute of Molecular Sciences and Biotechnology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Lisa G Wood
- Centre for Asthma and Respiratory Disease, Hunter Medical Research Institute, University of Newcastle, Newcastle, New South Wales 2300, Australia
| | - Vanessa E Murphy
- Centre for Asthma and Respiratory Disease, Hunter Medical Research Institute, University of Newcastle, Newcastle, New South Wales 2300, Australia
| | - Joerg Mattes
- Centre for Asthma and Respiratory Disease, Hunter Medical Research Institute, University of Newcastle, Newcastle, New South Wales 2300, Australia
| | - Peter G Gibson
- Centre for Asthma and Respiratory Disease, Hunter Medical Research Institute, University of Newcastle, Newcastle, New South Wales 2300, Australia
| | - Charles R Mackay
- 1] Department of Immunology, Monash University, Clayton, Victoria 3800, Australia [2] Charles Perkins Centre, Sydney University Medical School, University of Sydney, Sydney, New South Wales 2006, Australia
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Dal-Secco D, Wang J, Zeng Z, Kolaczkowska E, Wong CHY, Petri B, Ransohoff RM, Charo IF, Jenne CN, Kubes P. A dynamic spectrum of monocytes arising from the in situ reprogramming of CCR2+ monocytes at a site of sterile injury. ACTA ACUST UNITED AC 2015; 212:447-56. [PMID: 25800956 PMCID: PMC4387291 DOI: 10.1084/jem.20141539] [Citation(s) in RCA: 317] [Impact Index Per Article: 35.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Accepted: 02/24/2015] [Indexed: 12/20/2022]
Abstract
Monocytes are recruited from the blood to sites of inflammation, where they contribute to wound healing and tissue repair. There are at least two subsets of monocytes: classical or proinflammatory (CCR2(hi)CX3CR1(low)) and nonclassical, patrolling, or alternative (CCR2(low)CX3CR1(hi)) monocytes. Using spinning-disk confocal intravital microscopy and mice with fluorescent reporters for each of these subsets, we were able to track the dynamic spectrum of monocytes that enter a site of sterile hepatic injury in vivo. We observed that the CCR2(hi)CX3CR1(low) monocytes were recruited early and persisted for at least 48 h, forming a ringlike structure around the injured area. These monocytes transitioned, in situ, from CCR2(hi)Cx3CR1(low) to CX3CR1(hi)CCR2(low) within the ringlike structure and then entered the injury site. This phenotypic conversion was essential for optimal repair. These results demonstrate a local, cytokine driven reprogramming of classic, proinflammatory monocytes into nonclassical or alternative monocytes to facilitate proper wound-healing.
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Affiliation(s)
- Daniela Dal-Secco
- Immunology Research Group, Snyder Institute for Chronic Diseases; Department of Microbiology, Immunology, and Infectious Diseases; and Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Jing Wang
- Immunology Research Group, Snyder Institute for Chronic Diseases; Department of Microbiology, Immunology, and Infectious Diseases; and Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada Immunology Research Group, Snyder Institute for Chronic Diseases; Department of Microbiology, Immunology, and Infectious Diseases; and Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Zhutian Zeng
- Immunology Research Group, Snyder Institute for Chronic Diseases; Department of Microbiology, Immunology, and Infectious Diseases; and Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada Immunology Research Group, Snyder Institute for Chronic Diseases; Department of Microbiology, Immunology, and Infectious Diseases; and Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Elzbieta Kolaczkowska
- Immunology Research Group, Snyder Institute for Chronic Diseases; Department of Microbiology, Immunology, and Infectious Diseases; and Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Connie H Y Wong
- Immunology Research Group, Snyder Institute for Chronic Diseases; Department of Microbiology, Immunology, and Infectious Diseases; and Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Björn Petri
- Immunology Research Group, Snyder Institute for Chronic Diseases; Department of Microbiology, Immunology, and Infectious Diseases; and Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada Immunology Research Group, Snyder Institute for Chronic Diseases; Department of Microbiology, Immunology, and Infectious Diseases; and Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Richard M Ransohoff
- Neuroinflammation Research Center, Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195
| | - Israel F Charo
- Gladstone Institute of Cardiovascular Disease and Cardiovascular Research Institute, Department of Medicine, University of California, San Francisco, San Francisco, CA 94143
| | - Craig N Jenne
- Immunology Research Group, Snyder Institute for Chronic Diseases; Department of Microbiology, Immunology, and Infectious Diseases; and Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada Immunology Research Group, Snyder Institute for Chronic Diseases; Department of Microbiology, Immunology, and Infectious Diseases; and Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Paul Kubes
- Immunology Research Group, Snyder Institute for Chronic Diseases; Department of Microbiology, Immunology, and Infectious Diseases; and Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada Immunology Research Group, Snyder Institute for Chronic Diseases; Department of Microbiology, Immunology, and Infectious Diseases; and Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
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Jenne CN, Wong CHY, Zemp FJ, McDonald B, Rahman MM, Forsyth PA, McFadden G, Kubes P. Neutrophils recruited to sites of infection protect from virus challenge by releasing neutrophil extracellular traps. Cell Host Microbe 2013; 13:169-80. [PMID: 23414757 DOI: 10.1016/j.chom.2013.01.005] [Citation(s) in RCA: 307] [Impact Index Per Article: 27.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2012] [Revised: 11/08/2012] [Accepted: 01/16/2013] [Indexed: 12/29/2022]
Abstract
Neutrophils mediate bacterial clearance through various mechanisms, including the release of mesh-like DNA structures or neutrophil extracellular traps (NETs) that capture bacteria. Although neutrophils are also recruited to sites of viral infection, their role in antiviral innate immunity is less clear. We show that systemic administration of virus analogs or poxvirus infection induces neutrophil recruitment to the liver microvasculature and the release of NETs that protect host cells from virus infection. After systemic intravenous poxvirus challenge, mice exhibit thrombocytopenia and the recruitment of both neutrophils and platelets to the liver vasculature. Circulating platelets interact with, roll along, and adhere to the surface of adherent neutrophils, forming large, dynamic aggregates. These interactions facilitate the release of NETs within the liver vasculature that are able to protect host cells from poxvirus infection. These findings highlight the role of NETs and early tissue-wide responses in preventing viral infection.
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Affiliation(s)
- Craig N Jenne
- Calvin, Phoebe, and Joan Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AB T2N 4N1, Canada
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Wong CHY, Jenne CN, Petri B, Chrobok NL, Kubes P. Nucleation of platelets with blood-borne pathogens on Kupffer cells precedes other innate immunity and contributes to bacterial clearance. Nat Immunol 2013; 14:785-92. [PMID: 23770641 PMCID: PMC4972575 DOI: 10.1038/ni.2631] [Citation(s) in RCA: 260] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2013] [Accepted: 04/25/2013] [Indexed: 12/13/2022]
Abstract
Using intravital imaging of the liver, we unveil a collaborative role for platelets with Kupffer cells (KCs) in eradicating bloodborne bacterial infections. Under basal conditions, platelets via glycoprotein Ib (GPIb) formed transient “touch-and-go” interactions with von Willebrand factor (vWF) constitutively expressed on KCs. Bacteria, such as Bacillus cereus and Methicillin-resistant Staphylococcus aureus (MRSA), were rapidly caught by KCs and triggered platelets to switch from “touch-and-go” to sustained GPIIb-mediated adhesion on the KC surface to encase the bacterium. Infected GpIbα−/− mice demonstrated increased endothelial and KC damage, leading to increased fluid leakage, significant polycythemia and rapid mortality. This study identifies a novel surveillance mechanism of intravascular macrophage by platelets that rapidly converts to a critical host response against bloodborne bacteria.
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Affiliation(s)
- Connie H Y Wong
- Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, Department of Physiology and Pharmacology, University of Calgary, Alberta, Canada
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Abstract
Systemic immunosuppression has been associated with stroke for many years, but the underlying mechanisms are poorly understood. In this study, we demonstrated that stroke induced profound behavioral changes in hepatic invariant NKT (iNKT) cells in mice. Unexpectedly, these effects were mediated by a noradrenergic neurotransmitter rather than a CD1d ligand or other well-characterized danger signals. Blockade of this innervation was protective in wild-type mice after stroke but had no effect in mice deficient in iNKT cells. Selective immunomodulation of iNKT cells with a specific activator (α-galactosylceramide) promoted proinflammatory cytokine production and prevented infections after stroke. Our results therefore identify a molecular mechanism that leads to immunosuppression after stroke and suggest an attractive potential therapeutic alternative to antibiotics, namely, immunomodulation of iNKT cells to prevent stroke-associated infections.
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Affiliation(s)
- Connie H Y Wong
- Calvin, Phoebe, and Joan Snyder Institute for Infection, Immunity, and Inflammation, University of Calgary, Calgary, Alberta, Canada
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Chen MJ, Wong CHY, Peng ZF, Manikandan J, Melendez AJ, Tan TM, Crack PJ, Cheung NS. A global transcriptomic view of the multifaceted role of glutathione peroxidase-1 in cerebral ischemic-reperfusion injury. Free Radic Biol Med 2011; 50:736-48. [PMID: 21193029 DOI: 10.1016/j.freeradbiomed.2010.12.025] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2010] [Revised: 12/09/2010] [Accepted: 12/16/2010] [Indexed: 12/01/2022]
Abstract
Transient cerebral ischemia often results in secondary ischemic/reperfusion injury, the pathogenesis of which remains unclear. This study provides a comprehensive, temporal description of the molecular events contributing to neuronal injury after transient cerebral ischemia. Intraluminal middle cerebral artery occlusion (MCAO) was performed to induce a 2-h ischemia with reperfusion. Microarray analysis was then performed on the infarct cortex of wild-type (WT) and glutathione peroxidase-1 (a major antioxidant enzyme) knockout (Gpx1(-/-)) mice at 8 and 24h postreperfusion to identify differential gene expression profile patterns and potential alternative injury cascades in the absence of Gpx1, a crucial antioxidant enzyme, in cerebral ischemia. Genes with at least ±1.5-fold change in expression at either time point were considered significant. Global transcriptomic analyses demonstrated that 70% of the WT-MCAO profile overlapped with that of Gpx1(-/-)-MCAO, and 28% vice versa. Critical analysis of the 1034 gene probes specific to the Gpx1(-/-)-MCAO profile revealed regulation of additional novel pathways, including the p53-mediated proapoptotic pathway and Fas ligand (CD95/Apo1)-mediated pathways; downplay of the Nrf2 antioxidative cascade; and ubiquitin-proteasome system dysfunction. Therefore, this comparative study forms the foundation for the establishment of screening platforms for target definition in acute cerebral ischemia intervention.
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MESH Headings
- Animals
- Apoptosis/genetics
- Disease Models, Animal
- Fas Ligand Protein/genetics
- Gene Expression Profiling
- Genes, p53
- Glutathione Peroxidase/genetics
- Glutathione Peroxidase/metabolism
- Infarction, Middle Cerebral Artery/genetics
- Infarction, Middle Cerebral Artery/metabolism
- Infarction, Middle Cerebral Artery/pathology
- Inflammation
- Ischemic Attack, Transient/genetics
- Ischemic Attack, Transient/metabolism
- Ischemic Attack, Transient/pathology
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- NF-E2-Related Factor 2/genetics
- Oligonucleotide Array Sequence Analysis
- Oxidation-Reduction
- Polymerase Chain Reaction
- Reactive Oxygen Species
- Reperfusion Injury/genetics
- Reperfusion Injury/metabolism
- Reperfusion Injury/pathology
- Reperfusion Injury/surgery
- Signal Transduction
- Ubiquitin-Protein Ligase Complexes/genetics
- Glutathione Peroxidase GPX1
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Lee WY, Moriarty TJ, Wong CHY, Zhou H, Strieter RM, van Rooijen N, Chaconas G, Kubes P. An intravascular immune response to Borrelia burgdorferi involves Kupffer cells and iNKT cells. Nat Immunol 2010; 11:295-302. [PMID: 20228796 DOI: 10.1038/ni.1855] [Citation(s) in RCA: 255] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2009] [Accepted: 02/12/2010] [Indexed: 12/11/2022]
Abstract
Here we investigate the dynamics of the hepatic intravascular immune response to a pathogen relevant to invariant natural killer T cells (iNKT cells). Immobilized Kupffer cells with highly ramified extended processes into multiple sinusoids could effectively capture blood-borne, disseminating Borrelia burgdorferi, creating a highly efficient surveillance and filtering system. After ingesting B. burgdorferi, Kupffer cells induced chemokine receptor CXCR3-dependent clustering of iNKT cells. Kupffer cells and iNKT cells formed stable contacts via the antigen-presenting molecule CD1d, which led to iNKT cell activation. An absence of iNKT cells caused B. burgdorferi to leave the blood and enter the joints more effectively. B. burgdorferi that escaped Kupffer cells entered the liver parenchyma and survived despite Ito cell responses. Kupffer cell-iNKT cell interactions induced a key intravascular immune response that diminished the dissemination of B. burgdorferi.
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Affiliation(s)
- Woo-Yong Lee
- Department of Physiology & Pharmacology, University of Calgary, Alberta, Canada
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Abstract
A fundamental feature of any immune response is the movement of leucocytes from one site in the body to another to provide effector functions. Therefore, elucidating the molecular mechanisms underlying the migration of leucocytes from the blood to tissues is critical to our understanding of immune function during inflammation. The classic steps of leucocyte trafficking involve leucocyte tethering and rolling on vessel walls of the vasculature, followed by firm adhesion to the endothelium. Recent evidence suggests that upon adhering, leucocytes crawl within the vessels before transmigrating across vessel walls and crawling into targeted tissues. The directed nature of the crawling events is orchestrated by a complex array of soluble factors and molecular regulators in combination with the local intravascular and extracellular environment. In fact, this process is known as chemotaxis and orientates cell movement in relation to the ligand gradient. Several signalling pathways have been proposed to be involved in this gradient-sensing and amplification process, but the best studied, discussed in detail here, is the phosphatidylinositol 3-kinase pathway. Substantial progress has been made in understanding how cells roll and adhere in blood vessels; however, how cells crawl in blood vessels, emigrate, and then crawl in tissues has received much less attention. Therefore, the focus of this review is to provide recent insights into molecular mechanisms and cellular processes that mediate leucocyte crawling in blood vessels and tissues during the inflammatory response.
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Affiliation(s)
- Connie H Y Wong
- Department of Physiology and Biophysics, Calvin, Phoebe and Joan Snyder Institute for Infection, Immunity and Inflammation, University of Calgary, HRIC 4A26A, 3280 Hospital Drive NW, Alberta, Canada T2N 4N1.
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Zhou H, Andonegui G, Wong CHY, Kubes P. Role of endothelial TLR4 for neutrophil recruitment into central nervous system microvessels in systemic inflammation. J Immunol 2009; 183:5244-50. [PMID: 19786543 DOI: 10.4049/jimmunol.0901309] [Citation(s) in RCA: 125] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Brain inflammation is a frequent consequence of sepsis and septic shock. We imaged leukocyte recruitment in brain postcapillary venules induced by i.p. administration of LPS as a simple model of systemic inflammation. The i.p. injection of LPS (0.5 mg/kg) induced significant leukocyte rolling and adhesion in brain postcapillary venules of wild-type (WT) mice and more than 90% were neutrophils. However, no emigrated neutrophils were detected in brain parenchyma. High levels of TNF-alpha and IL-1beta were detected in the plasma after LPS injection but a different profile (IL-1beta but not TNF-alpha) was detected in the brain. LPS caused no recruitment in TLR4 knockout mice. In chimeric mice with TLR4-expressing resident cells but TLR4-deficient bone marrow-derived circulating cells, neutrophil rolling and adhesion was similar to WT mice. This observation is consistent with a requirement for resident cells in the LPS-induced neutrophil recruitment into brain microvessels. Transgenic mice engineered to express TLR4 exclusively on endothelial cells had a similar level of leukocyte recruitment in brain as WT mice in response to LPS. High dose LPS (10 mg/kg) led to neutrophil infiltration in the brain parenchyma in WT mice. High KC and MIP-2 production was observed from brain parenchyma microglial cells, and CXCR2 knockout mice failed to recruit neutrophils. However, neither neutrophil infiltration nor KC or MIP-2 was observed in endothelial TLR4 transgenic mice in response to this LPS dose. Our results demonstrate that direct endothelial activation is sufficient to mediate leukocyte rolling and adhesion in cerebral microvessels but not sufficient for emigration to brain parenchyma.
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Affiliation(s)
- Hong Zhou
- Immunology Research Group, Department Physiology and Biophysics, University of Calgary, NW Calgary, Alberta, Canada
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Wong CHY, Bozinovski S, Hertzog PJ, Hickey MJ, Crack PJ. Absence of glutathione peroxidase-1 exacerbates cerebral ischemia-reperfusion injury by reducing post-ischemic microvascular perfusion. J Neurochem 2008; 107:241-52. [DOI: 10.1111/j.1471-4159.2008.05605.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Abstract
The mechanisms leading to cellular damage from ischemia-reperfusion (I/R) injury are complex and multi-factorial. Accumulating evidence suggests an important role for oxidative stress in the regulation of neuro-inflammation following stroke. Gene expression studies have revealed that the increase in oxygen radicals post-ischemia triggers the expression of a number of pro-inflammatory genes. These genes are regulated by the transcription factor, nuclear factor-kappa-B (NF-kappaB) which is redox-sensitive. It is hypothesised that changes in the oxidative state may modulate alterations in the neuro-inflammatory response following an I/R injury. Furthermore, NF-kappaB is involved in the transcriptional regulation of adhesion molecules, which play an important role in leukocyte-endothelium interactions. Recent studies have demonstrated that adhesion molecule-mediated leukocyte recruitment is associated with increased tissue damage in stroke, while mice lacking key adhesion molecules conferred neuro-protection. Nevertheless, the involvement of oxidative stress in leukocyte recruitment and the subsequent regulated cell injury is yet to be elucidated. While leukocyte infiltration into the ischemic brain is detrimental, leukocyte accumulation in the microvasculature was shown to be one of the many factors implicated in reduced reperfusion. Although this "no-reflow" phenomenon was confirmed in a variety of animal models of cerebral ischemia, the exact mechanism is still uncertain. This review aims to highlight the impact that oxidative stress has in the regulation of post-ischemic neuro-inflammation and the implication for the cerebral microvasculature after injury.
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Affiliation(s)
- Connie H Y Wong
- Centre for Functional Genomics and Human Disease, Monash Institute of Medical Research, Monash University, Victoria, Australia
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Chan WK, Chung TS, Lau BST, Law HT, Yeung AKM, Wong CHY. Management of hypertension by private doctors in Hong Kong. Hong Kong Med J 2006; 12:115-8. [PMID: 16603778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2023] Open
Abstract
OBJECTIVE To investigate the management of hypertension by private doctors in Hong Kong. DESIGN Self-administered questionnaire survey. SETTING Hong Kong. PARTICIPANTS Private doctors from all districts in Hong Kong selected by simple random sampling from the website of "The Hong Kong Doctors Homepage" from March to June 2005. MAIN OUTCOME MEASURES Practice of blood pressure measurement and the treatment prescribed to hypertensive patients. RESULTS A total of 225 (46%) completed questionnaires were analysed. Only 24.4% of the respondents measured blood pressure in all new patients aged above 18 years. A total of 28.0% of doctors reported that hypertensive status was unknown in over 30% of their patients prior to their first clinic visit when it was consequently diagnosed. Calcium channel blockers (31%), angiotensin-converting enzyme inhibitors (28.5%), diuretics (27.5%), and beta-blockers (21.2%) were the most commonly prescribed antihypertensive medication. Drug efficacy was the reason cited by more than half (56.9%) of doctors for selecting a given drug. Public education about hypertension was considered insufficient by 66.2% of doctors and 32% believed that self-medication would have a very significant effect on drug compliance. CONCLUSIONS In private clinics, blood pressure measurement should become a routine procedure. There is a need to raise public awareness of hypertension.
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Affiliation(s)
- W K Chan
- Division of Cardiology, Department of Medicine and Geriatrics, United Christian Hospital, Kwun Tong, Hong Kong.
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