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Bruserud Ø, Mosevoll KA, Bruserud Ø, Reikvam H, Wendelbo Ø. The Regulation of Neutrophil Migration in Patients with Sepsis: The Complexity of the Molecular Mechanisms and Their Modulation in Sepsis and the Heterogeneity of Sepsis Patients. Cells 2023; 12:cells12071003. [PMID: 37048076 PMCID: PMC10093057 DOI: 10.3390/cells12071003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 03/21/2023] [Accepted: 03/22/2023] [Indexed: 03/29/2023] Open
Abstract
Sepsis is defined as life-threatening organ dysfunction caused by a dysregulated host response to infection. Common causes include gram-negative and gram-positive bacteria as well as fungi. Neutrophils are among the first cells to arrive at an infection site where they function as important effector cells of the innate immune system and as regulators of the host immune response. The regulation of neutrophil migration is therefore important both for the infection-directed host response and for the development of organ dysfunctions in sepsis. Downregulation of CXCR4/CXCL12 stimulates neutrophil migration from the bone marrow. This is followed by transmigration/extravasation across the endothelial cell barrier at the infection site; this process is directed by adhesion molecules and various chemotactic gradients created by chemotactic cytokines, lipid mediators, bacterial peptides, and peptides from damaged cells. These mechanisms of neutrophil migration are modulated by sepsis, leading to reduced neutrophil migration and even reversed migration that contributes to distant organ failure. The sepsis-induced modulation seems to differ between neutrophil subsets. Furthermore, sepsis patients should be regarded as heterogeneous because neutrophil migration will possibly be further modulated by the infecting microorganisms, antimicrobial treatment, patient age/frailty/sex, other diseases (e.g., hematological malignancies and stem cell transplantation), and the metabolic status. The present review describes molecular mechanisms involved in the regulation of neutrophil migration; how these mechanisms are altered during sepsis; and how bacteria/fungi, antimicrobial treatment, and aging/frailty/comorbidity influence the regulation of neutrophil migration.
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Affiliation(s)
- Øystein Bruserud
- Leukemia Research Group, Department of Clinical Science, University of Bergen, 5021 Bergen, Norway
- Section for Hematology, Department of Medicine, Haukeland University Hospital, 5021 Bergen, Norway
- Correspondence:
| | - Knut Anders Mosevoll
- Section for Infectious Diseases, Department of Medicine, Haukeland University Hospital, 5021 Bergen, Norway
- Section for Infectious Diseases, Department of Clinical Research, University of Bergen, 5021 Bergen, Norway
| | - Øyvind Bruserud
- Department for Anesthesiology and Intensive Care, Haukeland University Hospital, 5021 Bergen, Norway
| | - Håkon Reikvam
- Leukemia Research Group, Department of Clinical Science, University of Bergen, 5021 Bergen, Norway
- Section for Hematology, Department of Medicine, Haukeland University Hospital, 5021 Bergen, Norway
| | - Øystein Wendelbo
- Section for Infectious Diseases, Department of Medicine, Haukeland University Hospital, 5021 Bergen, Norway
- Faculty of Health, VID Specialized University, Ulriksdal 10, 5009 Bergen, Norway
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Rudloff S, Bileck A, Janker L, Wanner N, Liaukouskaya N, Lundby C, Huber TB, Gerner C, Huynh-Do U. Dichotomous responses to chronic fetal hypoxia lead to a predetermined aging phenotype. Mol Cell Proteomics 2021; 21:100190. [PMID: 34958949 PMCID: PMC8808178 DOI: 10.1016/j.mcpro.2021.100190] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 12/07/2021] [Accepted: 12/21/2021] [Indexed: 12/29/2022] Open
Abstract
Hypoxia-induced intrauterine growth restriction increases the risk for cardiovascular, renal and other chronic diseases in adults, representing thus a major public health problem. Still, not much is known about the fetal mechanisms that predispose these individuals to disease. Using a previously validated mouse model of fetal hypoxia and bottom-up proteomics we characterize the response of the fetal kidney to chronic hypoxic stress. Fetal kidneys exhibit a dichotomous response to chronic hypoxia, comprising on the one hand cellular adaptations that promote survival (glycolysis, autophagy, and reduced DNA and protein synthesis), but on the other processes that induce a senescence-like phenotype (infiltration of inflammatory cells, DNA damage, and reduced proliferation). Importantly, chronic hypoxia also reduces the expression of the anti-aging proteins klotho and Sirt6, a mechanism that is evolutionary conserved between mice and humans. Taken together, we uncover that predetermined aging during fetal development is a key event in chronic hypoxia, establishing a solid foundation for Barker's hypothesis of fetal programming of adult diseases. This phenotype is associated with a characteristic biomarker profile in tissue and serum samples, exploitable for detecting and targeting accelerated aging in chronic hypoxic human diseases.
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Affiliation(s)
- Stefan Rudloff
- Division of Nephrology and Hypertension, University of Bern and University Hospital Bern, Freiburgstrasse 15, CH-3010 Bern, Switzerland
| | - Andrea Bileck
- Department of Analytical Chemistry, Faculty of Chemistry, University of Vienna, Waehringer Strasse 38, A-1090 Vienna, Austria
| | - Lukas Janker
- Department of Analytical Chemistry, Faculty of Chemistry, University of Vienna, Waehringer Strasse 38, A-1090 Vienna, Austria
| | - Nicola Wanner
- University Medical Center Hamburg-Eppendorf, III. Medizinische Klinik und Poliklinik, Martinistrasse 52, D-20246 Hamburg, Germany
| | - Nastassia Liaukouskaya
- University Medical Center Hamburg-Eppendorf, III. Medizinische Klinik und Poliklinik, Martinistrasse 52, D-20246 Hamburg, Germany
| | - Carsten Lundby
- Centre for Physical Activity Research (CFAS), Rigshospitalet Section 7641, Ole Maaloesvej 24, DK-2100 Copenhagen, Denmark; Faculty of Social and Health Sciences, Section for Health and Exercise Physiology, Inland Norway University of Applied Sciences, NO-2624 Lillehammer, Norway
| | - Tobias B Huber
- University Medical Center Hamburg-Eppendorf, III. Medizinische Klinik und Poliklinik, Martinistrasse 52, D-20246 Hamburg, Germany
| | - Christopher Gerner
- Department of Analytical Chemistry, Faculty of Chemistry, University of Vienna, Waehringer Strasse 38, A-1090 Vienna, Austria.
| | - Uyen Huynh-Do
- Division of Nephrology and Hypertension, University of Bern and University Hospital Bern, Freiburgstrasse 15, CH-3010 Bern, Switzerland.
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Richardson IM, Calo CJ, Hind LE. Microphysiological Systems for Studying Cellular Crosstalk During the Neutrophil Response to Infection. Front Immunol 2021; 12:661537. [PMID: 33986752 PMCID: PMC8111168 DOI: 10.3389/fimmu.2021.661537] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Accepted: 04/09/2021] [Indexed: 12/13/2022] Open
Abstract
Neutrophils are the primary responders to infection, rapidly migrating to sites of inflammation and clearing pathogens through a variety of antimicrobial functions. This response is controlled by a complex network of signals produced by vascular cells, tissue resident cells, other immune cells, and the pathogen itself. Despite significant efforts to understand how these signals are integrated into the neutrophil response, we still do not have a complete picture of the mechanisms regulating this process. This is in part due to the inherent disadvantages of the most-used experimental systems: in vitro systems lack the complexity of the tissue microenvironment and animal models do not accurately capture the human immune response. Advanced microfluidic devices incorporating relevant tissue architectures, cell-cell interactions, and live pathogen sources have been developed to overcome these challenges. In this review, we will discuss the in vitro models currently being used to study the neutrophil response to infection, specifically in the context of cell-cell interactions, and provide an overview of their findings. We will also provide recommendations for the future direction of the field and what important aspects of the infectious microenvironment are missing from the current models.
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Affiliation(s)
| | | | - Laurel E. Hind
- Department of Chemical and Biological Engineering, University of Colorado – Boulder, Boulder, CO, United States
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Zhao Y, Ting KK, Coleman P, Qi Y, Chen J, Vadas M, Gamble J. The Tumour Vasculature as a Target to Modulate Leucocyte Trafficking. Cancers (Basel) 2021; 13:cancers13071724. [PMID: 33917287 PMCID: PMC8038724 DOI: 10.3390/cancers13071724] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Revised: 03/29/2021] [Accepted: 04/03/2021] [Indexed: 12/14/2022] Open
Abstract
Simple Summary Tumour blood vessels, characterised by abnormal morphology and function, create an immunosuppressive tumour microenvironment via restricting the appropriate leucocyte subsets trafficking. Strategies to trigger phenotypic alteration in tumour vascular system to resemble normal vascular system, named vascular normalisation, promote effective trafficking of leucocytes into tumours through enhancing the interactions between leucocytes and endothelial cells. This review specifically demonstrates how targeting tumour blood vessels modulates the critical steps of leucocyte trafficking. Furthermore, selective regulation of leucocyte subsets trafficking in tumours can be achieved by vasculature-targeting strategies, contributing to improved immunotherapy and thereby delayed tumour progression. Abstract The effectiveness of immunotherapy against solid tumours is dependent on the appropriate leucocyte subsets trafficking and accumulating in the tumour microenvironment (TME) with recruitment occurring at the endothelium. Such recruitment involves interactions between the leucocytes and the endothelial cells (ECs) of the vessel and occurs through a series of steps including leucocyte capture, their rolling, adhesion, and intraluminal crawling, and finally leucocyte transendothelial migration across the endothelium. The tumour vasculature can curb the trafficking of leucocytes through influencing each step of the leucocyte recruitment process, ultimately producing an immunoresistant microenvironment. Modulation of the tumour vasculature by strategies such as vascular normalisation have proven to be efficient in facilitating leucocyte trafficking into tumours and enhancing immunotherapy. In this review, we discuss the underlying mechanisms of abnormal tumour vasculature and its impact on leucocyte trafficking, and potential strategies for overcoming the tumour vascular abnormalities to boost immunotherapy via increasing leucocyte recruitment.
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Affiliation(s)
- Yang Zhao
- Department of Biochemistry and Molecular Biology, School of Medicine & Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing 210023, China
- Correspondence: (Y.Z.); (J.G.); Tel.: +86-025-85811237 (Y.Z.); +61-02-95656225 (J.G.)
| | - Ka Ka Ting
- Vascular Biology Program, Centenary Institute, The University of Sydney, Sydney 2050, Australia; (K.K.T.); (P.C.); (Y.Q.); (M.V.)
| | - Paul Coleman
- Vascular Biology Program, Centenary Institute, The University of Sydney, Sydney 2050, Australia; (K.K.T.); (P.C.); (Y.Q.); (M.V.)
| | - Yanfei Qi
- Vascular Biology Program, Centenary Institute, The University of Sydney, Sydney 2050, Australia; (K.K.T.); (P.C.); (Y.Q.); (M.V.)
| | - Jinbiao Chen
- Liver Injury and Cancer Program, Centenary Institute, The University of Sydney, Sydney 2050, Australia;
| | - Mathew Vadas
- Vascular Biology Program, Centenary Institute, The University of Sydney, Sydney 2050, Australia; (K.K.T.); (P.C.); (Y.Q.); (M.V.)
| | - Jennifer Gamble
- Vascular Biology Program, Centenary Institute, The University of Sydney, Sydney 2050, Australia; (K.K.T.); (P.C.); (Y.Q.); (M.V.)
- Correspondence: (Y.Z.); (J.G.); Tel.: +86-025-85811237 (Y.Z.); +61-02-95656225 (J.G.)
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Paracellular and Transcellular Leukocytes Diapedesis Are Divergent but Interconnected Evolutionary Events. Genes (Basel) 2021; 12:genes12020254. [PMID: 33578809 PMCID: PMC7916592 DOI: 10.3390/genes12020254] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 02/03/2021] [Accepted: 02/06/2021] [Indexed: 12/15/2022] Open
Abstract
Infiltration of the endothelial layer of the blood-brain barrier by leukocytes plays a critical role in health and disease. When passing through the endothelial layer during the diapedesis process lymphocytes can either follow a paracellular route or a transcellular one. There is a debate whether these two processes constitute one mechanism, or they form two evolutionary distinct migration pathways. We used artificial intelligence, phylogenetic analysis, HH search, ancestor sequence reconstruction to investigate further this intriguing question. We found that the two systems share several ancient components, such as RhoA protein that plays a critical role in controlling actin movement in both mechanisms. However, some of the key components differ between these two transmigration processes. CAV1 genes emerged during Trichoplax adhaerens, and it was only reported in transcellular process. Paracellular process is dependent on PECAM1. PECAM1 emerged from FASL5 during Zebrafish divergence. Lastly, both systems employ late divergent genes such as ICAM1 and VECAM1. Taken together, our results suggest that these two systems constitute two different mechanical sensing mechanisms of immune cell infiltrations of the brain, yet these two systems are connected. We postulate that the mechanical properties of the cellular polarity is the main driving force determining the migration pathway. Our analysis indicates that both systems coevolved with immune cells, evolving to a higher level of complexity in association with the evolution of the immune system.
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Neutrophil transendothelial migration: updates and new perspectives. Blood 2019; 133:2149-2158. [PMID: 30898863 DOI: 10.1182/blood-2018-12-844605] [Citation(s) in RCA: 119] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Accepted: 03/14/2019] [Indexed: 02/06/2023] Open
Abstract
Neutrophils represent the first line of cellular defense against invading microorganism by rapidly moving across the blood-endothelial cell (EC) barrier and exerting effector cell functions. The neutrophil recruitment cascade to inflamed tissues involves elements of neutrophil rolling, firm adhesion, and crawling onto the EC surface before extravasating by breaching the EC barrier. The interaction between neutrophils and ECs occurs via various adhesive modules and is a critical event determining the mode of neutrophil transmigration, either at the EC junction (paracellular) or directly through the EC body (transcellular). Once thought to be a homogenous entity, new evidence clearly points to the plasticity of neutrophil functions. This review will focus on recent advances in our understanding of the mechanism of the neutrophil transmigration process. It will discuss how neutrophil-EC interactions and the subsequent mode of diapedesis, junctional or nonjunctional, can be context dependent and how this plasticity may be exploited clinically.
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de Almeida CJG. Caveolin-1 and Caveolin-2 Can Be Antagonistic Partners in Inflammation and Beyond. Front Immunol 2017; 8:1530. [PMID: 29250058 PMCID: PMC5715436 DOI: 10.3389/fimmu.2017.01530] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Accepted: 10/27/2017] [Indexed: 12/26/2022] Open
Abstract
Caveolins, encoded by the CAV gene family, are the main protein components of caveolae. In most tissues, caveolin-1 (Cav-1) and caveolin-2 (Cav-2) are co-expressed, and Cav-2 targeting to caveolae depends on the formation of heterooligomers with Cav-1. Notwithstanding, Cav-2 has unpredictable activities, opposing Cav-1 in the regulation of some cellular processes. While the major roles of Cav-1 as a modulator of cell signaling in inflammatory processes and in immune responses have been extensively discussed elsewhere, the aim of this review is to focus on data revealing the distinct activity of Cav-1 and Cav-2, which suggest that these proteins act antagonistically to fine-tune a variety of cellular processes relevant to inflammation.
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Baratchi S, Khoshmanesh K, Woodman OL, Potocnik S, Peter K, McIntyre P. Molecular Sensors of Blood Flow in Endothelial Cells. Trends Mol Med 2017; 23:850-868. [PMID: 28811171 DOI: 10.1016/j.molmed.2017.07.007] [Citation(s) in RCA: 111] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 07/16/2017] [Accepted: 07/19/2017] [Indexed: 01/08/2023]
Abstract
Mechanical stress from blood flow has a significant effect on endothelial physiology, with a key role in initiating vasoregulatory signals. Disturbances in blood flow, such as in regions of disease-associated stenosis, arterial branch points, and sharp turns, can induce proatherogenic phenotypes in endothelial cells. The disruption of vascular homeostasis as a result of endothelial dysfunction may contribute to early and late stages of atherosclerosis, the underlying cause of coronary artery disease. In-depth knowledge of the mechanobiology of endothelial cells is essential to identifying mechanosensory complexes involved in the pathogenesis of atherosclerosis. In this review, we describe different blood flow patterns and summarize current knowledge on mechanosensory molecules regulating endothelial vasoregulatory functions, with clinical implications. Such information may help in the search for novel therapeutic approaches.
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Affiliation(s)
- Sara Baratchi
- School of Health and Biomedical Sciences, RMIT University, Melbourne, VIC 3083, Australia; Baker Heart and Diabetes Institute, Melbourne, VIC 3004, Australia.
| | | | - Owen L Woodman
- School of Health and Biomedical Sciences, RMIT University, Melbourne, VIC 3083, Australia
| | - Simon Potocnik
- School of Health and Biomedical Sciences, RMIT University, Melbourne, VIC 3083, Australia
| | - Karlheinz Peter
- School of Health and Biomedical Sciences, RMIT University, Melbourne, VIC 3083, Australia; Baker Heart and Diabetes Institute, Melbourne, VIC 3004, Australia
| | - Peter McIntyre
- School of Health and Biomedical Sciences, RMIT University, Melbourne, VIC 3083, Australia
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9
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Caveolin-1 Is Critical for Lymphocyte Trafficking into Central Nervous System during Experimental Autoimmune Encephalomyelitis. J Neurosci 2017; 36:5193-9. [PMID: 27170118 DOI: 10.1523/jneurosci.3734-15.2016] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Accepted: 04/07/2016] [Indexed: 11/21/2022] Open
Abstract
UNLABELLED Multiple sclerosis (MS) is a progressive autoimmune disease of the CNS with its underlying mechanisms not fully understood. In the present study, we tested the hypothesis that caveolin-1, a major membrane scaffolding protein, plays a critical role in the pathogenesis of experimental autoimmune encephalomyelitis, a laboratory murine model of MS. We found increased expression of caveolin-1 in serum and spinal cord tissues in association with disease incidence and severity in wild-type mice with active encephalomyelitis. After immunization, Cav-1 knock-out mice showed remarkable disease resistance with decreased incidence and clinical symptoms. Furthermore, Cav-1 knock-out mice had alleviated encephalitogenic T cells trafficking into the CNS with decreased expressions of adhesion molecules ICAM-1 and VCAM-1 within the lesions. In agreement with in vivo studies, in vitro knockdown of caveolin-1 compromised the upregulation of ICAM-1 in endothelial cells, leading to the amelioration of the transendothelial migration of pathogenic TH1 and TH17 cells. Together, those results indicate that caveolin-1 serves as an active modulator of CNS-directed lymphocyte trafficking and could be a therapeutic target for neuroinflammatory diseases, such as multiple sclerosis. SIGNIFICANCE STATEMENT The hallmark feature of neuroinflammatory diseases is the massive infiltrations of encephalitogenic leukocytes into the CNS parenchyma, a process that remains largely unclear. Our study demonstrates the critical contribution of caveolin-1 to encephalomyelitis pathogenesis and CNS-directed lymphocyte trafficking by modulation of adhesion molecules ICAM-1 and VCAM-1, highlighting the pathological involvement of caveolin-1 in neuroinflammatory diseases.
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Schmidt EP, Kuebler WM, Lee WL, Downey GP. Adhesion Molecules: Master Controllers of the Circulatory System. Compr Physiol 2016; 6:945-73. [PMID: 27065171 DOI: 10.1002/cphy.c150020] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
This manuscript will review our current understanding of cellular adhesion molecules (CAMs) relevant to the circulatory system, their physiological role in control of vascular homeostasis, innate and adaptive immune responses, and their importance in pathophysiological (disease) processes such as acute lung injury, atherosclerosis, and pulmonary hypertension. This is a complex and rapidly changing area of research that is incompletely understood. By design, we will begin with a brief overview of the structure and classification of the major groups of adhesion molecules and their physiological functions including cellular adhesion and signaling. The role of specific CAMs in the process of platelet aggregation and hemostasis and leukocyte adhesion and transendothelial migration will be reviewed as examples of the complex and cooperative interplay between CAMs during physiological and pathophysiological processes. The role of the endothelial glycocalyx and the glycobiology of this complex system related to inflammatory states such as sepsis will be reviewed. We will then focus on the role of adhesion molecules in the pathogenesis of specific disease processes involving the lungs and cardiovascular system. The potential of targeting adhesion molecules in the treatment of immune and inflammatory diseases will be highlighted in the relevant sections throughout the manuscript.
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Affiliation(s)
- Eric P Schmidt
- Division of Pulmonary Sciences and Critical Care Medicine, Department of Medicine, University of Colorado, Aurora, Colorado, USA
| | - Wolfgang M Kuebler
- Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, Ontario, Canada
- Departments of Surgery and Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Warren L Lee
- Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, Ontario, Canada
- Division of Respirology and the Interdepartmental Division of Critical Care Medicine, Department of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Gregory P Downey
- Division of Pulmonary Sciences and Critical Care Medicine, Department of Medicine, University of Colorado, Aurora, Colorado, USA
- Division of Pulmonary, Critical Care, and Sleep Medicine, Departments of Medicine, Pediatrics, and Biomedical Research, National Jewish Health, Denver, Colorado, USA
- Departments of Medicine, and Immunology and Microbiology, University of Colorado, Aurora, Colorado, USA
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Abstract
The neutrophil transmigration across the blood endothelial cell barrier represents the prerequisite step of innate inflammation. Neutrophil recruitment to inflamed tissues occurs in a well-defined stepwise manner, which includes elements of neutrophil rolling, firm adhesion, and crawling onto the endothelial cell surface before transmigrating across the endothelial barrier. This latter step known as diapedesis can occur at the endothelial cell junction (paracellular) or directly through the endothelial cell body (transcellular). The extravasation cascade is controlled by series of engagement of various adhesive modules, which result in activation of bidirectional signals to neutrophils and endothelial cells for adequate cellular response. This review will focus on recent advances in our understanding of mechanism of leukocyte crawling and diapedesis, with an emphasis on leukocyte-endothelial interactions and the signaling pathways they transduce to determine the mode of diapedesis, junctional or nonjunctional. I will also discuss emerging evidence highlighting key differences in the two modes of diapedesis and why it is clinically important to understand specificity in the regulation of diapedesis.
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Affiliation(s)
- Marie-Dominique Filippi
- Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Research Foundation, Cincinnati, Ohio, USA; University of Cincinnati College of Medicine, Cincinnati, Ohio, USA.
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Filippi MD. Leukocyte transcellular diapedesis: Rap1b is in control. Tissue Barriers 2015; 3:e1052185. [PMID: 26451346 DOI: 10.1080/21688370.2015.1052185] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Revised: 05/11/2015] [Accepted: 05/13/2015] [Indexed: 12/30/2022] Open
Abstract
The neutrophil transmigration across the blood endothelial cell barrier represents the prerequisite step of innate inflammation. It is well known that neutrophils cross the endothelial barrier by transmigrating at the endothelial cell junction ('paracellular'). However, in vivo and in vitro evidence have clearly demonstrated occurrence of an alternate mode of migration directly through the endothelial cell body ('transcellular'). Despite our knowledge on mechanisms of transendothelial migration, it remains unclear which factors determine distinct modes of migration. We recently found that the Ras-like Rap1b GTPase limits neutrophil transcellular migration. Rap1b restrains transcellular migration by suppressing Akt-driven invasive protrusions while leaving the paracellular route unaffected. Furthermore, Rap1b limits neutrophil tissue infiltration in mice and prevents hyper susceptibility to endotoxin shock. These findings uncover a novel role for Rap1b in neutrophil migration and inflammation. Importantly, they offer emerging evidences that paracellular and transcellular migration of neutrophils are regulated by separate mechanisms. Here, we discuss the mechanisms of neutrophil transmigration and their clinical importance for vascular integrity and innate inflammation.
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Affiliation(s)
- Marie-Dominique Filippi
- Division of Experimental Hematology and Cancer Biology; Cincinnati Children's Research Foundation ; Cincinnati, OH USA ; University of Cincinnati College of Medicine ; Cincinnati, OH USA
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13
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Li X, Gu X, Boyce TM, Zheng M, Reagan AM, Qi H, Mandal N, Cohen AW, Callegan MC, Carr DJJ, Elliott MH. Caveolin-1 increases proinflammatory chemoattractants and blood-retinal barrier breakdown but decreases leukocyte recruitment in inflammation. Invest Ophthalmol Vis Sci 2014; 55:6224-34. [PMID: 25159208 DOI: 10.1167/iovs.14-14613] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
PURPOSE Caveolin-1 (Cav-1), the signature protein of caveolae, modulates inflammatory responses, and innate immunity. However, Cav-1's role in retinal inflammation has not been rigorously tested. In this study, we examined the effect of Cav-1 ablation on the sensitivity of the retina to inflammation. METHODS Cav-1 knockout (KO) mice were challenged by intravitreal injection of lipopolysaccharide (LPS) and inflammatory cell recruitment was assessed by flow cytometry and immunohistochemistry. Leukostasis was assessed in retinal flatmounts after perfusion with FITC-labeled Concanavalin A (FITC-ConA). Chemoattractants were measured by multiplex immunoassays. Blood-retinal barrier (BRB) breakdown was assessed quantitatively by a FITC-dextran permeability assay. The ratio of extravascular to total immune cells was determined by CD45 immunohistochemistry of retinal flatmounts. RESULTS Inflammatory challenge resulted in significant blunting of proinflammatory cytokine (monocyte chemoattractant protein-1 [MCP-1/CCL2], CXCL1/KC, IL-6, and IL-1β) responses as well as reduced inflammatory BRB breakdown in Cav-1 KO retinas. Paradoxically, Cav-1 deficiency resulted in significantly increased recruitment of immune cells compared with controls as well as increased leukostasis. A similar ratio of extravascular/total leukocytes were found in Cav-1 KO and wild-type (WT) retinas suggesting that Cav-1 deficient leukocytes were as competent to extravasate as those from WT mice. We found increased levels of circulating immune cells in naïve (not challenged with LPS) Cav-1 KO mice compared with controls. CONCLUSIONS Caveolin-1 paradoxically modulates inflammatory signaling and leukocyte infiltration through distinct mechanisms. We hypothesize that Cav-1 expression may enhance inflammatory signaling while at the same time supporting the physical properties of the BRB.
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Affiliation(s)
- Xiaoman Li
- Department of Ophthalmology/Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States
| | - Xiaowu Gu
- Department of Ophthalmology/Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States
| | - Timothy M Boyce
- Department of Ophthalmology/Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States
| | - Min Zheng
- Department of Ophthalmology/Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States
| | - Alaina M Reagan
- Department of Ophthalmology/Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States
| | - Hui Qi
- Department of Ophthalmology/Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States
| | - Nawajes Mandal
- Department of Ophthalmology/Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States
| | - Alex W Cohen
- Department of Ophthalmology/Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States
| | - Michelle C Callegan
- Department of Ophthalmology/Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States
| | - Daniel J J Carr
- Department of Ophthalmology/Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States Department of Microbiology & Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States
| | - Michael H Elliott
- Department of Ophthalmology/Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States
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14
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Crossing the wall: The opening of endothelial cell junctions during infectious diseases. Int J Biochem Cell Biol 2013; 45:1165-73. [DOI: 10.1016/j.biocel.2013.03.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Revised: 03/05/2013] [Accepted: 03/15/2013] [Indexed: 12/22/2022]
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Voisin MB, Nourshargh S. Neutrophil transmigration: emergence of an adhesive cascade within venular walls. J Innate Immun 2013; 5:336-47. [PMID: 23466407 DOI: 10.1159/000346659] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Accepted: 12/20/2012] [Indexed: 12/26/2022] Open
Abstract
Recruitment of neutrophils from the blood circulation to sites of infection or injury is a key innate immune response against invading pathogens and tissue injury. However, if inappropriately triggered, excessive and/or prolonged, this host defence response can also lead to severe pathological disorders. The migration of all leucocytes out of the vasculature is classically described by the leucocyte adhesion cascade that depicts a well-characterised sequence of cellular and molecular events within the vascular lumen. Recent findings have now illustrated that beyond the vascular lumen, the breaching of the venular wall can also involve an analogous cascade of adhesive events. For neutrophils this involves a tightly regulated and sequential series of responses within venular walls, initiating with adhesive steps that guide neutrophils through endothelial cells lining the venular wall, followed by responses that mediate and regulate their migration through the pericyte sheath and the venular basement membrane. The present review aims to provide a brief summary of novel additions to the classical adhesion cascade within the vascular lumen and then to discuss the emergence of a second adhesion cascade for neutrophils within venular walls, the latter illustrating the intricacies and complexities of neutrophil transmigration.
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Affiliation(s)
- Mathieu-Benoit Voisin
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK
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16
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Goddard LM, Iruela-Arispe ML. Cellular and molecular regulation of vascular permeability. Thromb Haemost 2013; 109:407-15. [PMID: 23389236 DOI: 10.1160/th12-09-0678] [Citation(s) in RCA: 103] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2012] [Accepted: 01/30/2013] [Indexed: 02/07/2023]
Abstract
Vascular permeability is a highly coordinated process that integrates vesicular trafficking, complex junctional rearrangements, and refined cytoskeletal dynamics. In response to the extracellular environment, these three cellular activities have been previously assumed to work in parallel to regulate the passage of solutes between the blood and tissues. New developments in the area of vascular permeability, however have highlighted the interdependence between trans- and para-cellular pathways, the cross-communication between adherens and tight junctions, and the instructional role of pericytes on endothelial expression of barrier-related genes. Additionally, significant effort has been placed in understanding the molecular underpinings that contribute to barrier restoration following acute permeability events and in clarifying the importance of context-dependent signaling initiated by permeability mediators. Finally, recent findings have uncovered an unpredicted role for transcription factors in the coordination of vascular permeability and clarified how junctional complexes can transmit signals to the nucleus to control barrier function. The goal of this review is to provide a concise and updated view of vascular permeability, discuss the most recent advances in molecular and cellular regulation, and introduce integrated information on the central mechanisms involved in trans-endothelial transport.
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Affiliation(s)
- Lauren M Goddard
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, CA 90095, USA
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17
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Reglero-Real N, Marcos-Ramiro B, Millán J. Endothelial membrane reorganization during leukocyte extravasation. Cell Mol Life Sci 2012; 69:3079-99. [PMID: 22573182 PMCID: PMC11114893 DOI: 10.1007/s00018-012-0987-4] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2011] [Revised: 03/22/2012] [Accepted: 03/29/2012] [Indexed: 12/30/2022]
Abstract
Leukocyte trafficking from the bloodstream to inflamed tissues across the endothelial barrier is an essential response in innate immunity. Leukocyte adhesion, locomotion, and diapedesis induce signaling in endothelial cells and this is accompanied by a profound reorganization of the endothelial cell surfaces that is only starting to be unveiled. Here we review the current knowledge on the leukocyte-mediated alterations of endothelial membrane dynamics and their role in promoting leukocyte extravasation. The formation of protein- and lipid-mediated cell adhesion nanodomains at the endothelial apical surface, the extension of micrometric apical membrane docking structures, which are derived from microvilli and embrace adhered leukocytes, as well as the vesicle-trafficking pathways that are required for efficient leukocyte diapedesis, are discussed. The coordination between these different endothelial membrane-remodeling events probably provides the road map for transmigrating leukocytes to find exit points in the vessel wall, in a context of severe mechanical and inflammatory stress. A better understanding of how vascular endothelial cells respond to immune cell adhesion should enable new therapeutic strategies to be developed that can abrogate uncontrolled leukocyte extravasation in inflammatory diseases.
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Affiliation(s)
- Natalia Reglero-Real
- Centro de Biología Molecular Severo Ochoa, CSIC-Universidad Autónoma de Madrid, C/Nicolás Cabrera 1, Cantoblanco, 28049 Madrid, Spain
| | - Beatriz Marcos-Ramiro
- Centro de Biología Molecular Severo Ochoa, CSIC-Universidad Autónoma de Madrid, C/Nicolás Cabrera 1, Cantoblanco, 28049 Madrid, Spain
| | - Jaime Millán
- Centro de Biología Molecular Severo Ochoa, CSIC-Universidad Autónoma de Madrid, C/Nicolás Cabrera 1, Cantoblanco, 28049 Madrid, Spain
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18
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Block H, Zarbock A. The role of the tec kinase Bruton's tyrosine kinase (Btk) in leukocyte recruitment. Int Rev Immunol 2012; 31:104-18. [PMID: 22449072 DOI: 10.3109/08830185.2012.668982] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Recruitment of leukocytes into inflamed tissue is a key component of the immune system. The activation of integrins on leukocytes is required for their recruitment into the inflamed tissue. Btk is a cytoplasmic nonreceptor tyrosine kinase belonging to the Tec-kinase family. It plays a key role in B-cell development and function, and recently published studies revealed important roles of Btk in myeloid cells. Btk might be activated through a variety of receptors leading to activation of integrins as the pivotal element in leukocyte recruitment. This review focuses on the role of Btk in B-lymphocyte homing and in neutrophil recruitment.
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Affiliation(s)
- Helena Block
- Department of Anesthesiology and Critical Care Medicine, University of Muenster, Muenster, Germany
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19
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Schmidt EP, Lee WL, Zemans RL, Yamashita C, Downey GP. On, around, and through: neutrophil-endothelial interactions in innate immunity. Physiology (Bethesda) 2012; 26:334-47. [PMID: 22013192 DOI: 10.1152/physiol.00011.2011] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
This manuscript will review our current understanding of neutrophilic polymorphonuclear leukocyte (neutrophil) interactions with the endothelium during immune and inflammatory responses, focusing on the molecular mechanisms regulating neutrophil adhesion to and migration through the endothelium in response to infection or tissue injury. This is a complex and dynamic area of research and one that has been the topic of several recent comprehensive reviews to which the interested reader is referred (64, 118, 131). By design, this review will begin with a brief review of some basic aspects of neutrophil biology and endothelial adhesion to provide a foundation. The remainder of the review will focus on selected areas of this complex field, specifically the role of the endothelial glycocalyx in regulating neutrophil adhesion and the mechanisms and consequences of migration of neutrophils between (paracellular) and through (transcellular) endothelial cells during egress from the vasculature.
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Affiliation(s)
- Eric P Schmidt
- Department of Medicine, Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado Denver, Aurora, Colorado, USA
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20
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Zarember KA, Kuhns DB. Editorial: will the real neutrophil please stand up? J Leukoc Biol 2011; 90:1039-41. [PMID: 22131359 PMCID: PMC3236553 DOI: 10.1189/jlb.0711334] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2011] [Revised: 08/01/2011] [Accepted: 08/03/2011] [Indexed: 01/13/2023] Open
Abstract
Discussion on exudate neutrophils as a more accurate model of the “working” functional in vivo neutrophil than their circulating progenitors.
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Affiliation(s)
- Kol A. Zarember
- Laboratory of Host Defenses, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA; and
| | - Douglas B. Kuhns
- Clinical Services Program, SAIC-Frederick, Inc., National Cancer Institute-Frederick, Frederick, Maryland, USA
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21
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Woodfin A, Voisin MB, Beyrau M, Colom B, Caille D, Diapouli FM, Nash GB, Chavakis T, Albelda SM, Rainger GE, Meda P, Imhof BA, Nourshargh S. The junctional adhesion molecule JAM-C regulates polarized transendothelial migration of neutrophils in vivo. Nat Immunol 2011; 12:761-9. [PMID: 21706006 PMCID: PMC3145149 DOI: 10.1038/ni.2062] [Citation(s) in RCA: 429] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2011] [Accepted: 05/26/2011] [Indexed: 12/14/2022]
Abstract
The migration of neutrophils into inflamed tissues is a fundamental component of innate immunity. A decisive step in this process is the polarized migration of blood neutrophils through endothelial cells (ECs) lining the venular lumen (transendothelial migration (TEM)) in a luminal-to-abluminal direction. By real-time confocal imaging, we found that neutrophils had disrupted polarized TEM ('hesitant' and 'reverse') in vivo. We noted these events in inflammation after ischemia-reperfusion injury, characterized by lower expression of junctional adhesion molecule C (JAM-C) at EC junctions, and they were enhanced by blockade or genetic deletion of JAM-C in ECs. Our results identify JAM-C as a key regulator of polarized neutrophil TEM in vivo and suggest that reverse TEM of neutrophils can contribute to the dissemination of systemic inflammation.
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Affiliation(s)
- Abigail Woodfin
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, UK
| | - Mathieu-Benoit Voisin
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, UK
| | - Martina Beyrau
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, UK
| | - Bartomeu Colom
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, UK
| | | | - Frantzeska-Maria Diapouli
- Centre for Cardiovascular Research, School of Clinical and Experimental Medicine, College of Medicine and Dentistry, University of Birmingham, B15 2TT
| | - Gerard B Nash
- Centre for Cardiovascular Research, School of Clinical and Experimental Medicine, College of Medicine and Dentistry, University of Birmingham, B15 2TT
| | | | | | - G Ed Rainger
- Centre for Cardiovascular Research, School of Clinical and Experimental Medicine, College of Medicine and Dentistry, University of Birmingham, B15 2TT
| | - Paolo Meda
- Centre Médical Universitaire, CH-1211 Geneva, Switzerland
| | - Beat A. Imhof
- Centre Médical Universitaire, CH-1211 Geneva, Switzerland
| | - Sussan Nourshargh
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, UK
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22
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Omri S, Behar-Cohen F, de Kozak Y, Sennlaub F, Verissimo LM, Jonet L, Savoldelli M, Omri B, Crisanti P. Microglia/macrophages migrate through retinal epithelium barrier by a transcellular route in diabetic retinopathy: role of PKCζ in the Goto Kakizaki rat model. THE AMERICAN JOURNAL OF PATHOLOGY 2011; 179:942-53. [PMID: 21712024 DOI: 10.1016/j.ajpath.2011.04.018] [Citation(s) in RCA: 151] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 11/17/2010] [Revised: 03/31/2011] [Accepted: 04/05/2011] [Indexed: 01/13/2023]
Abstract
Diabetic retinopathy is associated with ocular inflammation, leading to retinal barrier breakdown, macular edema, and visual cell loss. We investigated the molecular mechanisms involved in microglia/macrophages trafficking in the retina and the role of protein kinase Cζ (PKCζ) in this process. Goto Kakizaki (GK) rats, a model for spontaneous type 2 diabetes were studied until 12 months of hyperglycemia. Up to 5 months, sparse microglia/macrophages were detected in the subretinal space, together with numerous pores in retinal pigment epithelial (RPE) cells, allowing inflammatory cell traffic between the retina and choroid. Intercellular adhesion molecule-1 (ICAM-1), caveolin-1 (CAV-1), and PKCζ were identified at the pore border. At 12 months of hyperglycemia, the significant reduction of pores density in RPE cell layer was associated with microglia/macrophages accumulation in the subretinal space together with vacuolization of RPE cells and disorganization of photoreceptors outer segments. The intraocular injection of a PKCζ inhibitor at 12 months reduced iNOS expression in microglia/macrophages and inhibited their migration through the retina, preventing their subretinal accumulation. We show here that a physiological transcellular pathway takes place through RPE cells and contributes to microglia/macrophages retinal trafficking. Chronic hyperglycemia causes alteration of this pathway and subsequent subretinal accumulation of activated microglia/macrophages.
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Affiliation(s)
- Samy Omri
- INSERM, U872 Physiopathology of Ocular Diseases, Therapeutic Innovations, Paris, France
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23
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Madsen CD, Sahai E. Cancer dissemination--lessons from leukocytes. Dev Cell 2010; 19:13-26. [PMID: 20643347 DOI: 10.1016/j.devcel.2010.06.013] [Citation(s) in RCA: 146] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2009] [Revised: 06/21/2010] [Accepted: 06/21/2010] [Indexed: 12/21/2022]
Abstract
Cancer cells can move through tissues in a variety of different ways. In some cases, an epithelial-to-mesenchymal transition enables cancer cells to acquire fibroblast-like migratory properties. However, it is also becoming apparent that some cancer cells move in an amoeboid way similar to leukocytes. This theme will be the focus of the review, where we will discuss the similarities and differences between the mechanisms used by cancer cells and leukocytes to cross parenchymal basement membranes, move through interstitial tissue, and enter and exit the vasculature. Further, we propose that the ability to switch between different migratory mechanisms is critical for cells to relocate from one tissue to another.
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Affiliation(s)
- Chris D Madsen
- Cancer Research UK London Research Institute, 44 Lincoln's Inn Fields, London WC2A 3PX, UK
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24
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Abstract
PURPOSE OF REVIEW Proper control of endothelial cell contacts is the basis for maintenance of the vascular barrier function. Loss of this function leads to leak of fluid and protein from the vasculature and extensive leaks cause shock and death. The endothelial barrier also controls the entry of leukocytes into tissue and it is believed that leukocytes target endothelial cell contacts to reach sites of inflammation. RECENT FINDINGS Within the last 2 years several new molecular players and molecular interactions have been identified that either help in stabilizing the endothelial contacts or mediate their opening if triggered by the appropriate stimuli. Novel signaling mechanisms have been identified that regulate endothelial cell contacts. Whether, how and to what extent the complex of the endothelial specific adhesion molecule vascular endothelial-cadherin and its associated catenins is involved in these processes will be a major focus of this article. SUMMARY Endothelial cell contacts are regulated by a complex interplay between various receptors and signaling mediators that control the plasticity of the cytoskeleton and the function of junctional adhesion molecules. Knowing and understanding the essential players of this network will allow development of agents that could prevent breakdown of the vascular permeability barrier in shock or that could block leukocyte extravasation and thereby antagonize inflammation.
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25
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Fu C, He J, Li C, Shyy JYJ, Zhu Y. Cholesterol increases adhesion of monocytes to endothelium by moving adhesion molecules out of caveolae. Biochim Biophys Acta Mol Cell Biol Lipids 2010; 1801:702-10. [DOI: 10.1016/j.bbalip.2010.04.001] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2009] [Revised: 03/31/2010] [Accepted: 04/01/2010] [Indexed: 01/13/2023]
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26
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Komarova Y, Malik AB. Regulation of endothelial permeability via paracellular and transcellular transport pathways. Annu Rev Physiol 2010; 72:463-93. [PMID: 20148685 DOI: 10.1146/annurev-physiol-021909-135833] [Citation(s) in RCA: 468] [Impact Index Per Article: 33.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The endothelium functions as a semipermeable barrier regulating tissue fluid homeostasis and transmigration of leukocytes and providing essential nutrients across the vessel wall. Transport of plasma proteins and solutes across the endothelium involves two different routes: one transcellular, via caveolae-mediated vesicular transport, and the other paracellular, through interendothelial junctions. The permeability of the endothelial barrier is an exquisitely regulated process in the resting state and in response to extracellular stimuli and mediators. The focus of this review is to provide a comprehensive overview of molecular and signaling mechanisms regulating endothelial barrier permeability with emphasis on the cross-talk between paracellular and transcellular transport pathways.
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Affiliation(s)
- Yulia Komarova
- Department of Pharmacology and Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago, IL 60612, USA
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27
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Abstract
PURPOSE OF REVIEW As the migration of neutrophils from blood to inflamed tissues is an essential component of innate immunity and a key contributing factor to the pathogenesis of inflammatory disorders, this aspect of leukocyte biology continues to be a highly dynamic field of research. This review summarizes recent findings in this area, focusing on the mechanisms that mediate neutrophil transmigration, an area where significant progress has been made. RECENT FINDINGS The topics to be covered will include responses that are prerequisite to neutrophil migration through venular walls, such as leukocyte luminal crawling and cellular and molecular changes in leukocytes and endothelial cells (e.g. formation of protrusions) that collectively support leukocyte transendothelial cell migration. Advances in both paracellular and transcellular neutrophil migration through endothelial cells will be discussed, addressing the associated roles and regulation of expression of endothelial cell luminal and junctional adhesion molecules. Beyond the endothelium, migration through the vascular pericyte coverage and basement membrane will be reviewed. SUMMARY The unquestionable role of neutrophils in the development and progression of inflammatory conditions suggests that a better understanding of the tissue-specific and stimulus-specific mechanisms that mediate this response may identify novel pathways that could be exploited for the development of more specific anti-inflammatory interventions.
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Affiliation(s)
- Abigail Woodfin
- Queen Mary University of London, William Harvey Research Institute, UK
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