151
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Stapleton PA, James ME, Goodwill AG, Frisbee JC. Obesity and vascular dysfunction. ACTA ACUST UNITED AC 2008; 15:79-89. [PMID: 18571908 DOI: 10.1016/j.pathophys.2008.04.007] [Citation(s) in RCA: 127] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2007] [Revised: 02/18/2008] [Accepted: 04/28/2008] [Indexed: 01/04/2023]
Abstract
One of the most profound challenges facing public health and public health policy in Western society is the increased incidence and prevalence of both overweight and obesity. While this condition can have significant consequences for patient mortality and quality of life, it can be further exacerbated as overweight/obesity can be a powerful stimulus for the development of additional risk factors for a negative cardiovascular outcome, including increased insulin resistance, dyslipidemia and hypertension. This manuscript will present the effects of systemic obesity on broad issues of vascular function in both afflicted human populations and in the most relevant animal models. Among the topics that will be covered are alterations to vascular reactivity (both dilator and constrictor responses), adaptations in microvascular network and vessel wall structure, and alterations to the patterns of tissue/organ perfusion as a result of the progression of the obese condition. Additionally, special attention will be paid to the contribution of chronic inflammation as a contributor to alterations in vascular function, as well as the role of perivascular adipose tissue in terms of impacting vessel behavior. When taken together, it is clearly apparent that the development of the obese condition can have profound, and frequently difficult to predict, impacts on integrated vascular function. Much of this complexity appears to have its basis in the extent to which other co-morbidities associated with obesity (e.g., insulin resistance) are present and exert contributing effects.
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Affiliation(s)
- Phoebe A Stapleton
- Division of Exercise Physiology, West Virginia University School of Medicine, Morgantown, WV 26506, USA
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152
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Chou MY, Hartvigsen K, Hansen LF, Fogelstrand L, Shaw PX, Boullier A, Binder CJ, Witztum JL. Oxidation-specific epitopes are important targets of innate immunity. J Intern Med 2008; 263:479-88. [PMID: 18410591 DOI: 10.1111/j.1365-2796.2008.01968.x] [Citation(s) in RCA: 117] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
During the oxidation of LDL, a central pathophysiological component of atherogenesis, a wide variety of chemical and physical changes occur leading to the generation of oxidation-specific neoepitopes. These epitopes are not only immunogenic, leading to adaptive humoral responses, but are also a prominent target of multiple arcs of innate immunity. The pattern recognition receptors (PRRs) of innate immunity are germ line encoded, conserved by natural selection, and bind to pathogen-associated molecular patterns (PAMPs) common on multiple structures. However, it is not intuitive as to why they should recognize oxidation-specific neoepitopes. Yet it is clear that multiple macrophage scavenger receptors, which are classic PRRs, recognize oxidation-specific epitopes, such as those found on oxidized LDL (OxLDL). Other innate proteins, such as C-reactive protein, also bind to OxLDL. Natural antibodies (NAbs), the humoral arc of innate immunity, provide a nonredundant role in the first line of defence against pathogens, but are also believed to provide important homeostatic house-keeping functions against self-antigens. Our work demonstrates that oxidation-specific epitopes, as found on OxLDL, are a major target of NAbs. In this review, we will discuss the specific example of the prototypic NAb T15/E06, which is increased in atherosclerotic mice and mediates atheroprotection, and discuss the potential role of NAbs in atherogenesis, and in inflammation in general. We also review data that oxidation-specific epitopes are generated whenever cells undergo programmed cell death, forming a common set of PAMPs recognized by oxidation-specific PRRs on macrophages, NAbs and innate proteins. We present the hypothesis that oxidation-specific epitopes on apoptotic cells exerted evolutionary pressure for the conservation of these PRRs and also serve to maintain the expansion of a substantial proportion of NAbs directed to these stress-induced self-antigens.
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Affiliation(s)
- M-Y Chou
- Department of Medicine, University of California at San Diego, La Jolla, CA, USA
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153
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Abstract
Atherosclerosis is a chronic inflammatory disease characterized by accumulation of oxidized lipoproteins, increased cell death and hypertrophic degeneration of the arterial intima. The disease process is associated with local formation of modified self antigens that are targeted by both innate and adaptive immune responses. Although it remains to be firmly established it is likely that these autoimmune responses initially have a beneficial effect facilitating the removal of potentially harmful rest products from oxidized LDL and dying cells. However, studies performed on hypercholesterolaemic mice deficient in different components of the immune system uniformly suggest that the net effect of immune activation is pro-atherogenic and that atherosclerosis, at least to some extent, should be regarded as an autoimmune disease. These observations point to the possibility of developing new treatments for atherosclerosis based on modulation of immune responses against plaque antigens, an approach presently tested clinically for several other chronic inflammatory diseases with autoimmune components. Pilot studies in animals have provided promising results for both parental and oral vaccines based on oxidized LDL antigens. The time when this concept is ready for clinical testing is rapidly approaching but it will be important not to underestimate the difficulties that will be encountered in transferring the promising results from experimental animals into humans.
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Affiliation(s)
- J Nilsson
- Department of Clinical Sciences, Malmö University Hospital, Lund University, Malmö, Sweden
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154
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van Leeuwen M, Gijbels MJ, Duijvestijn A, Smook M, van de Gaar MJ, Heeringa P, de Winther MP, Tervaert JWC. Accumulation of Myeloperoxidase-Positive Neutrophils in Atherosclerotic Lesions in LDLR
−/−
Mice. Arterioscler Thromb Vasc Biol 2008; 28:84-9. [DOI: 10.1161/atvbaha.107.154807] [Citation(s) in RCA: 160] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Objective—
Atherosclerosis is a chronic inflammatory disease in which the immune system plays an important role. Neutrophils have not been thoroughly studied in the context of atherogenesis. Here, we investigated neutrophils in the development of murine atherosclerotic lesions.
Methods and Results—
LDLR
−/−
mice were given a high-fat diet for different time periods and subsequently atherosclerotic lesions were studied by immunohistochemistry. Staining with anti–Ly-6G monoclonal antibody, a specific marker for neutrophils, revealed a marked accumulation of neutrophils during atherosclerosis development. Neutrophils were observed in the lesion, attached to the cap, and in the arterial adventitia. In addition, at some sites, neutrophil accumulation colocalized with endothelial E-selectin expression. Immunofluorescence double staining with anti-myeloperoxidase and anti–Ly-6G antibodies demonstrated the presence of myeloperoxidase in atherosclerotic lesions and its colocalization with neutrophils. After introducing the high-fat diet, levels of circulating myeloperoxidase in plasma strongly increased, with a peak at 6 weeks and a subsequent decrease to almost normal levels after 16 weeks of diet.
Conclusions—
We here demonstrate for the first time the presence of neutrophils and myeloperoxidase in murine atherosclerotic lesions. As a major cell type in inflammatory responses the neutrophil may also be an important mediator in the development of atherosclerosis.
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Affiliation(s)
- Marcella van Leeuwen
- From the Departments of Clinical and Experimental Immunology (M.v.L., A.D., M.S., M.J.v.d.G., P.H., J.W.C.T.), Molecular Genetics (M.J.J.G., M.P.J.d.W.), and Pathology (M.J.J.G.), Cardiovascular Research Institute Maastricht, Maastricht University; and the Department of Pathology and Laboratory Medicine (P.H.), Medical Biology Section, University Medical Center Groningen, Groningen, the Netherlands
| | - Marion J.J. Gijbels
- From the Departments of Clinical and Experimental Immunology (M.v.L., A.D., M.S., M.J.v.d.G., P.H., J.W.C.T.), Molecular Genetics (M.J.J.G., M.P.J.d.W.), and Pathology (M.J.J.G.), Cardiovascular Research Institute Maastricht, Maastricht University; and the Department of Pathology and Laboratory Medicine (P.H.), Medical Biology Section, University Medical Center Groningen, Groningen, the Netherlands
| | - Adriaan Duijvestijn
- From the Departments of Clinical and Experimental Immunology (M.v.L., A.D., M.S., M.J.v.d.G., P.H., J.W.C.T.), Molecular Genetics (M.J.J.G., M.P.J.d.W.), and Pathology (M.J.J.G.), Cardiovascular Research Institute Maastricht, Maastricht University; and the Department of Pathology and Laboratory Medicine (P.H.), Medical Biology Section, University Medical Center Groningen, Groningen, the Netherlands
| | - Marjan Smook
- From the Departments of Clinical and Experimental Immunology (M.v.L., A.D., M.S., M.J.v.d.G., P.H., J.W.C.T.), Molecular Genetics (M.J.J.G., M.P.J.d.W.), and Pathology (M.J.J.G.), Cardiovascular Research Institute Maastricht, Maastricht University; and the Department of Pathology and Laboratory Medicine (P.H.), Medical Biology Section, University Medical Center Groningen, Groningen, the Netherlands
| | - Marie José van de Gaar
- From the Departments of Clinical and Experimental Immunology (M.v.L., A.D., M.S., M.J.v.d.G., P.H., J.W.C.T.), Molecular Genetics (M.J.J.G., M.P.J.d.W.), and Pathology (M.J.J.G.), Cardiovascular Research Institute Maastricht, Maastricht University; and the Department of Pathology and Laboratory Medicine (P.H.), Medical Biology Section, University Medical Center Groningen, Groningen, the Netherlands
| | - Peter Heeringa
- From the Departments of Clinical and Experimental Immunology (M.v.L., A.D., M.S., M.J.v.d.G., P.H., J.W.C.T.), Molecular Genetics (M.J.J.G., M.P.J.d.W.), and Pathology (M.J.J.G.), Cardiovascular Research Institute Maastricht, Maastricht University; and the Department of Pathology and Laboratory Medicine (P.H.), Medical Biology Section, University Medical Center Groningen, Groningen, the Netherlands
| | - Menno P.J. de Winther
- From the Departments of Clinical and Experimental Immunology (M.v.L., A.D., M.S., M.J.v.d.G., P.H., J.W.C.T.), Molecular Genetics (M.J.J.G., M.P.J.d.W.), and Pathology (M.J.J.G.), Cardiovascular Research Institute Maastricht, Maastricht University; and the Department of Pathology and Laboratory Medicine (P.H.), Medical Biology Section, University Medical Center Groningen, Groningen, the Netherlands
| | - Jan Willem Cohen Tervaert
- From the Departments of Clinical and Experimental Immunology (M.v.L., A.D., M.S., M.J.v.d.G., P.H., J.W.C.T.), Molecular Genetics (M.J.J.G., M.P.J.d.W.), and Pathology (M.J.J.G.), Cardiovascular Research Institute Maastricht, Maastricht University; and the Department of Pathology and Laboratory Medicine (P.H.), Medical Biology Section, University Medical Center Groningen, Groningen, the Netherlands
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155
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Hollan I, Prayson R, Saatvedt K, Almdahl SM, Nossent HC, Mikkelsen K, Liang MH, Kvelstad IL, Aamodt G, Førre ØT. Inflammatory Cell Infiltrates in Vessels With Different Susceptibility to Atherosclerosis in Rheumatic and Non-Rheumatic Patients A Controlled Study of Biopsy Specimens Obtained at Coronary Artery Surgery. Circ J 2008; 72:1986-92. [DOI: 10.1253/circj.cj-08-0473] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Ivana Hollan
- Department of Cardiac Surgery, Feiring Heart Clinic
- Hospital for Rheumatic Diseases
| | | | - Kjell Saatvedt
- Department of Cardiothoracic Surgery, Rikshospitalet University Hospital
| | | | - Hans C. Nossent
- Department of Rheumatology, University Hospital of North Norway
| | | | | | | | - Geir Aamodt
- Department of Epidemiology, Norwegian Institute of Public Health
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156
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Nachtigal M, Ghaffar A, Mayer EP. Galectin-3 gene inactivation reduces atherosclerotic lesions and adventitial inflammation in ApoE-deficient mice. THE AMERICAN JOURNAL OF PATHOLOGY 2007; 172:247-55. [PMID: 18156214 DOI: 10.2353/ajpath.2008.070348] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
This study has examined the role of galectin-3 (GaL3), a multicompartmented N-acetyllactosamine-binding chimeric lectin, on atherogenesis in the ApoE-deficient mouse model of atherosclerosis. Pathological changes consisting of atheromatous plaques, atherosclerotic microaneurysms extending into periaortic vascular channels, and adventitial and periaortic inflammatory infiltrates were assessed in an equal number (n = 36) of apolipoprotein (Apo)E-deficient mice and ApoE-GaL3 double-knockout mice. These mice were divided into three age groups, 21 to 23 weeks, 25 to 31 weeks, and 36 to 44 weeks of age. Results of this morphological analysis have shown an age-related increase in the incidence of aorta atheromatous plaques and periaortic vascular channels in ApoE-deficient mice. By contrast ApoE/GaL3 double-knockout mice did not show an increase in pathological changes with age. The 36- to 44-week group of ApoE(-/-)/GaL3(-/-) mice had a significantly lower number of atherosclerotic lesions (P < 0.004) and fewer atheromatous plaques (P < 0.008) when compared with ApoE(-/-)/GaL3+/+ mice of the same age. ApoE(-/-)/GaL3(-/-) mice had a lower number of perivascular inflammatory infiltrates and mast cells than those found in ApoE(-/-)/GaL3+/+ mice. The reduced number of perivascular mast cells may have resulted in a low level of interleukin-4 that contributed to the reduction in the morphological parameters of atherogenesis correlated with the lack of GaL3 expression. The effect of GaL3 deficiency on atherogenesis decrease could be related to its function as a multifunctional protein implicated in macrophage chemotaxis, angiogenesis, lipid loading, and inflammation.
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Affiliation(s)
- Maurice Nachtigal
- Department of Pathology, Microbiology, and Immunology, University of South Carolina School of Medicine, Columbia, SC 29208, USA
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157
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Klingenberg R, Nofer JR, Rudling M, Bea F, Blessing E, Preusch M, Grone HJ, Katus HA, Hansson GK, Dengler TJ. Sphingosine-1-Phosphate Analogue FTY720 Causes Lymphocyte Redistribution and Hypercholesterolemia in ApoE-Deficient Mice. Arterioscler Thromb Vasc Biol 2007; 27:2392-9. [PMID: 17761943 DOI: 10.1161/atvbaha.107.149476] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Objective—
Resident immune cells are a hallmark of atherosclerotic lesions. The sphingolipid analogue drug FTY720 mediates retrafficking of immune cells and inhibits their homing to inflammatory sites. We have evaluated the effect of FTY720 on atherogenesis and lipid metabolism.
Methods and Results—
ApoE
−/−
mice on a normal laboratory diet received oral FTY720 for 12 weeks, which led to a 2.4-fold increase in serum cholesterol (largely VLDL fraction) and a 1.8-fold increase in hepatic HMGCoA reductase mRNA. FTY720 increased plasma sphingosine-1-phosphate and induced marked peripheral blood lymphopenia. A discoordinate modulation of B, T and monocyte cell numbers was found in peripheral lymphoid organs. Overall depletion of T cells was accompanied by a relative (2-fold) increase in regulatory T cell content paralleled by a similar increase in effector memory T cells (CD4+CD44hiCD62lo) as absolute numbers of both subpopulations remained essentially unchanged. Lymphocyte function was unaltered as indicated by anti-OxLDL antibodies and T cell proliferation. There were no changes in atherosclerotic lesions in early and established atherosclerosis.
Conclusions—
FTY720 mediated peripheral lymphocyte depletion and retrafficking without altering function and overall balance of pro- and antiatherogenic lymphocyte populations. A net decrease in lymphocyte numbers occurred concomitantly with a more proatherogenic hypercholesterolemia resulting in unaltered atherogenesis.
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158
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Gossl M, Lerman LO, Lerman A. Frontiers in nephrology: early atherosclerosis--a view beyond the lumen. J Am Soc Nephrol 2007; 18:2836-42. [PMID: 17928505 DOI: 10.1681/asn.2007030333] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Endothelial dysfunction is an established clinical marker of early coronary artery disease and has been shown to be associated with increased cardiovascular morbidity and mortality. New concepts now extend the view of endothelial dysfunction beyond the traditional involvement of the coronary arterial endothelium alone. Recent research indicates that the coronary vessel wall, especially the vasa vasorum, as well as bone marrow-derived endothelial progenitor cells may be subject to proatherosclerotic changes, even before the development of angiographically evident endothelial dysfunction; therefore, "microvascular endothelial dysfunction," which is composed of dysfunction of the vasa vasorum's endothelium as well as "microcellular endothelial dysfunction," reflecting impaired mobilization and function of endothelial progenitor cells, may precede "macrovascular endothelial dysfunction." Vasa vasorum neovascularization, with endothelial leakage and dysfunction increasing influx of proinflammatory and proatherogenic cellular and noncellular substances into the vessel wall, is proposed as one feature of this new concept. In addition, the role of bone marrow-derived endothelial progenitor cells is discussed as are the potential impact of impaired progenitor cell mobilization, release from the marrow, and function in acute and stable coronary artery disease. Finally, potential future therapies are proposed, focusing on interventions that may prevent or diminish the development of the microvascular and microcellular endothelial dysfunction.
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Affiliation(s)
- Mario Gossl
- Division of Cardiovascular Diseases, Mayo Clinic College of Medicine, Rochester, MN 55905, USA
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159
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Galkina E, Harry BL, Ludwig A, Liehn EA, Sanders JM, Bruce A, Weber C, Ley K. CXCR6 promotes atherosclerosis by supporting T-cell homing, interferon-gamma production, and macrophage accumulation in the aortic wall. Circulation 2007; 116:1801-11. [PMID: 17909108 DOI: 10.1161/circulationaha.106.678474] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND T lymphocytes are thought to be important in atherosclerosis, but very little is known about the mechanisms of lymphocyte recruitment into atherosclerosis-prone aortas. In this study we tested the hypothesis that CXCR6, a chemokine receptor that is expressed on a subset of CD4+ T helper 1 cells and natural killer T cells, is involved in lymphocyte homing into the aortic wall and modulates the development and progression of atherosclerosis. METHODS AND RESULTS To investigate the role of CXCR6 in the development and progression of atherosclerosis, we bred CXCR6-deficient (CXCR6(GFP/GFP)) mice with apolipoprotein E-deficient (ApoE(-/-)) mice. We found that CXCR6(GFP/GFP)/ApoE(-/-) mice fed a Western diet for 17 weeks or a chow diet for 56 weeks had decreased atherosclerosis compared with ApoE(-/-) controls. Flow cytometry analysis of the aortas from CXCR6(GFP/GFP)/ApoE(-/-) mice showed that the reduction of atherosclerosis was accompanied by a decreased percentage of CXCR6+ T cells within the aortas. Short-term homing experiments demonstrated that CXCR6 is involved in the recruitment of CXCR6+ leukocytes into the atherosclerosis-prone aortic wall. The reduced percentage of CXCR6+ T cells within the aortas resulted in significantly diminished production of interferon-gamma and reduction of CD11b+/CD68+ macrophages in the aorta. CONCLUSIONS These data provide evidence for a proatherosclerotic role of CXCR6. Absence of CXCR6 alters the recruitment of CXCR6+ leukocytes and modulates the local immune response within the aortic wall.
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Affiliation(s)
- Elena Galkina
- Department of Biomedical Engineering and Robert M. Berne Cardiovascular Research Center, University of Virginia, Health Sciences Center, Charlottesville, VA 22908, USA.
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160
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Rao RM, Yang L, Garcia-Cardena G, Luscinskas FW. Endothelial-dependent mechanisms of leukocyte recruitment to the vascular wall. Circ Res 2007; 101:234-47. [PMID: 17673684 DOI: 10.1161/circresaha.107.151860b] [Citation(s) in RCA: 292] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Inflammation is a fundamental process that protects organisms by removing or neutralizing injurious agents. A key event in the inflammatory response is the localized recruitment of various leukocyte subsets. Here we address the cellular and regulatory mechanisms of leukocyte recruitment to the vessel wall in cardiovascular disease and discuss our evolving understanding of the role of the vascular endothelium in this process. The vascular endothelium is the continuous single-cell lining of the cardiovascular system that forms a critical interface between the blood and its components on one side and the tissues and organs on the other. It is heterogeneous and has many synthetic and metabolic functions including secretion of platelet-derived growth factor, von Willebrand factor, prostacyclin, NO, endothelin-1, and chemokines and the expression of adhesion molecules. It also acts as a nonthrombogenic and selective permeable barrier. Endothelial cells also interact closely with the extracellular matrix and with adjacent cells including pericytes and smooth muscle cells within the vessel wall. A central question in vascular biology is the role of the endothelium in the initiation of inflammatory response, the extent of its "molecular conversations" with recruited leukocytes, and its influence on the extent and/or outcome of this response.
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Affiliation(s)
- Ravi M Rao
- Vascular Science, National Heart and Lung Institute, Imperial College School of Medicine, Hammersmith Hospital, London, UK
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161
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Abstract
Numerous reports document the role of vascular adhesion molecules in the development and progression of atherosclerosis. Recent novel findings in the field of adhesion molecules require an updated summary of current research. In this review, we highlight the role of vascular adhesion molecules including selectins, vascular cell adhesion molecule (VCAM)-1, intercellular adhesion molecule1 (ICAM-1), PECAM-1, JAMs, and connexins in atherosclerosis. The immune system is important in atherosclerosis, and significant efforts are under way to understand the vascular adhesion molecule-dependent mechanisms of immune cell trafficking into healthy and atherosclerosis-prone arterial walls. This review focuses on the role of vascular adhesion molecules in the regulation of immune cell homing during atherosclerosis and discusses future directions that will lead to better understanding of this disease.
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Affiliation(s)
- Elena Galkina
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA 22908, USA
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162
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Maiellaro K, Taylor WR. The role of the adventitia in vascular inflammation. Cardiovasc Res 2007; 75:640-8. [PMID: 17662969 PMCID: PMC3263364 DOI: 10.1016/j.cardiores.2007.06.023] [Citation(s) in RCA: 288] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2007] [Revised: 06/19/2007] [Accepted: 06/21/2007] [Indexed: 10/23/2022] Open
Abstract
Traditional concepts of vascular inflammation are considered "inside-out" responses centered on the monocyte adhesion and lipid oxidation hypotheses. These mechanisms likely operate in concert, holding the central tenet that the inflammatory response is initiated at the luminal surface. However, growing evidence supports a new paradigm of an "outside-in" hypothesis, in which vascular inflammation is initiated in the adventitia and progresses inward toward the intima. Hallmarks of the outside-in hypothesis include population of the adventitia with exogenous cell types, including monocytes, macrophages, and lymphocytes, the phenotypic switch of adventitial fibroblasts into migratory myofibroblasts, and increased vasa vasorum neovascularization. The resident and migrating cells deposit collagen and matrix components, respond to and upregulate inflammatory chemokines and/or antigens, and regulate the local redox state of the adventitia. B cells and T cells generate local humoral immune responses against local antigen presentation by foam cells and antigen presenting cells. These events result in increased local expression of cytokines and growth factors, evoking an inflammatory response that propagates inward toward the intima. Ultimately, it appears that the basic mechanisms of cellular activation and migration in vascular inflammation are highly conserved across a variety of cardiovascular disease states and that major inflammatory events begin in the adventitia.
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Affiliation(s)
- Kathryn Maiellaro
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, GA, USA.
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163
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Maffia P, Zinselmeyer BH, Ialenti A, Kennedy S, Baker AH, McInnes IB, Brewer JM, Garside P. Images in cardiovascular medicine. Multiphoton microscopy for 3-dimensional imaging of lymphocyte recruitment into apolipoprotein-E-deficient mouse carotid artery. Circulation 2007; 115:e326-8. [PMID: 17372180 DOI: 10.1161/circulationaha.106.658492] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Pasquale Maffia
- Department of Experimental Pharmacology, University of Naples Federico II, via D. Montesano 49, 80131 Naples, Italy.
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164
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Michel JB, Thaunat O, Houard X, Meilhac O, Caligiuri G, Nicoletti A. Topological determinants and consequences of adventitial responses to arterial wall injury. Arterioscler Thromb Vasc Biol 2007; 27:1259-68. [PMID: 17395854 DOI: 10.1161/atvbaha.106.137851] [Citation(s) in RCA: 147] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Arteries are composed of 3 concentric tissue layers which exhibit different structures and properties. Because arterial injury is generally initiated at the interface with circulating blood, most studies performed to unravel the mechanisms involved in injury-induced arterial responses have focused on the innermost layer (intima) rather than on the outermost adventitial layer. In the present review, we focus on the involvement of the adventitia in response to various types of arterial injury leading to vascular remodeling. Physiologically, soluble vascular mediators are centrifugally conveyed by mass transport toward the adventitia. Moreover, in pathological conditions, neomediators and antigens can be generated within the arterial wall, whose outward conveyance triggers different patterns of local adventitial response. Adventitial angiogenesis, immunoinflammation, and fibrosis sequentially interact and their net balance defines the participation of the adventitial response in arterial pathology. In the present review we discuss 4 pathological entities in which the adventitial response to arterial wall injury participates in arterial wall remodeling. Hence, the adventitial adaptive immune response predominates in chronic rejection. Inflammatory phagocytic cell recruitment and initiation of a shift from innate to adaptive immunity characterize the adventitial response to products of proteolysis in abdominal aortic aneurysm. Adventitial sprouting of neovessels, leading to intraplaque hemorrhages, predominates in atherothrombosis. Adventitial fibrosis characterizes the response to mechanical stress and is responsible for the constrictive remodeling of arterial segments and initiating interstitial fibrosis in perivascular tissues. These adventitial events, therefore, have an impact not only on the vessel wall biology but also on the surrounding tissue.
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Affiliation(s)
- Jean-Baptiste Michel
- INSERM unit 698 and University Denis Diderot-Paris 7, CHU Xavier Bichat, 46 rue Henri Huchard, 75018 Paris, France.
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165
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Jackson CL, Bennett MR, Biessen EAL, Johnson JL, Krams R. Assessment of unstable atherosclerosis in mice. Arterioscler Thromb Vasc Biol 2007; 27:714-20. [PMID: 17332492 DOI: 10.1161/01.atv.0000261873.86623.e1] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
There is an urgent need for representative animal models where prospective examination of the events leading up to plaque rupture and the rupture process itself can be performed. Recently, reports have begun to emerge that apolipoprotein E and low density lipoprotein receptor knockout mice may spontaneously develop unstable atherosclerosis, with plaques in certain parts of the arterial tree showing features suggestive of plaque rupture. Here we discuss the problems inherent in applying definitions of plaque rupture as seen in human arteries to mice; the anatomic locations in mice where unstable plaques do and do not occur; methods of inducing plaque instability in mice; and how to assess plaque stability in mice. These considerations lead us to a number of general recommendations.
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Affiliation(s)
- Christopher L Jackson
- Bristol Heart Institute, Bristol Royal Infirmary, University of Bristol, Bristol, UK.
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166
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Funk CD, Cao RY, Zhao L, Habenicht AJR. Is there a role for the macrophage 5-lipoxygenase pathway in aortic aneurysm development in apolipoprotein E-deficient mice? Ann N Y Acad Sci 2007; 1085:151-60. [PMID: 17182931 DOI: 10.1196/annals.1383.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Activation of the 5-lipoxygenase (5-LO) pathway leads to the biosynthesis of proinflammatory leukotriene (LT) lipid mediators in macrophages, mast cells, and other inflammatory cell types. A recent surge in interest in this pathway within the cardiovascular system has arisen from a variety of exciting findings using genetic, pathological specimen, and biochemical approaches in humans and mice. We found that a subset of CD68-positive macrophages, localized within the adventitial layer of apolipoprotein E (apo E)-deficient mice, expressed 5-LO and that these cells represented a significant cellular component of aortic aneurysms induced by an atherogenic diet containing cholate. Surprisingly, almost no 5-LO-expressing cells were observed in atherosclerotic lesions in the same mice. Correspondingly, lesion size in the fat-fed mice did not depend on 5-LO gene expression but aneurysm incidence was reduced in the absence of the 5-LO pathway. We are currently exploring the potential mechanisms for 5-LO/LT involvement in aneurysm pathogenesis and if this pathway might come into play in other models such as induction by angiotensin II.
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Affiliation(s)
- Colin D Funk
- Department of Physiology, Queen's University, Kingston, ON K7L 3N6 Canada.
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167
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Hayden MR, Karuparthi PR, Chowdhury NA, Govindarajan G, Habibi J, Ortmann RA. Autoimmune Vasculitis and Plaque Erosion in the Cardiometabolic Syndrome and Type 2 Diabetes Mellitus. ACTA ACUST UNITED AC 2006; 1:228-32. [PMID: 17679803 DOI: 10.1111/j.1559-4564.2006.05817.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Melvin R Hayden
- Department of Internal Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Missouri School of Medicine, Harry S.Truman VA Medical Center, Columbia, MO, USA.
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168
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Eriksson EE. Atherosclerosis: cell biology and lipoproteins. Curr Opin Lipidol 2006; 17:369-71. [PMID: 16680043 DOI: 10.1097/01.mol.0000226130.25252.5c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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169
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Galkina E, Kadl A, Sanders J, Varughese D, Sarembock IJ, Ley K. Lymphocyte recruitment into the aortic wall before and during development of atherosclerosis is partially L-selectin dependent. ACTA ACUST UNITED AC 2006; 203:1273-82. [PMID: 16682495 PMCID: PMC2121208 DOI: 10.1084/jem.20052205] [Citation(s) in RCA: 354] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Atherosclerosis is an inflammatory disease of large arteries. Flow cytometry of aortic cell suspensions showed that B and T lymphocytes and some macrophages and dendritic cells are already present in the adventitia of normal/noninflamed mouse aortas. Adoptively transferred lymphocytes constitutively homed to the aorta and resided within the adventitia up to 7 d after transfer. Lymphocyte trafficking into normal/noninflamed or atherosclerosis-prone aortas was partially L-selectin dependent. Antigen-activated dendritic cells induced increased T lymphocyte proliferation within the aorta 72 h after adoptive transfer. During progression of atherosclerosis in apolipoprotein-E-deficient mice, the total number of macrophages, T cells, and dendritic cells, but not B cells, increased significantly. This alteration in immune cell composition was accompanied by the formation of tertiary lymphoid tissue in the adventitia of atherosclerotic aortas. These results demonstrate that lymphocytes already reside within the normal/noninflamed aorta before the onset atherosclerosis as a consequence of constitutive trafficking. Atherosclerosis induces the recruitment of macrophages and dendritic cells that support antigen presentation.
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Affiliation(s)
- Elena Galkina
- Department of Biomedical Engineering, University of Virginia, Health Sciences Center, Charlottesville, VA 22908, USA
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170
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Saraswathi V, Hasty AH. The role of lipolysis in mediating the proinflammatory effects of very low density lipoproteins in mouse peritoneal macrophages. J Lipid Res 2006; 47:1406-15. [PMID: 16639077 DOI: 10.1194/jlr.m600159-jlr200] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Hypertriglyceridemia is an important risk factor for atherosclerosis, especially in obesity. Macrophages are one of the primary cell types involved in atherogenesis and are thought to contribute to lesion formation through both lipid accumulation and proinflammatory gene expression. In this study, we sought to determine the direct impact of triglyceride (TG)-rich VLDL-induced lipid accumulation on macrophage proinflammatory processes. Incubation of mouse peritoneal macrophages with 100 microg/ml VLDL for 6 h led to 2.8- and 3.7-fold increases in intracellular TGs and FFAs, respectively (P < 0.05). The inflammatory proteins tumor necrosis factor-alpha, interleukin-1beta, monocyte chemoattractant protein-1, intercellular adhesion molecule-1, matrix metalloproteinase 3 (MMP3), and macrophage inflammatory protein-1alpha (MIP-1alpha) were all upregulated by at least 2-fold (P < 0.05) in a dose-dependent manner in VLDL-treated macrophages. The increase in inflammatory gene expression coincided with the phosphorylation of the mitogen-activated protein kinase (MAPK) pathway members extracellular signal-regulated kinase (ERK) 1/2, stress-activated protein kinase/c-Jun NH2-terminal kinase, and p38 MAPK and was ameliorated by U0126, an inhibitor of ERK1/2. Inhibition of extracellular TG hydrolysis with tetrahydrolipstatin (Orlistat) resulted in the absence of intracellular TG and FFA accumulation and was accompanied by the amelioration of ERK1/2 phosphorylation and MIP-1alpha gene expression. These data indicate that VLDL hydrolysis, and the subsequent accumulation of intracellular FFAs and TGs, plays a substantive role in mediating the proinflammatory effects of VLDL. These data have important implications for the direct proatherogenic effects of VLDL on macrophage-driven atherosclerosis.
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Affiliation(s)
- Viswanathan Saraswathi
- Department of Molecular Physiology and Biophysics,Vanderbilt University Medical Center, Nashville, TN 37232, USA
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