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Schneider JG, Finck BN, Ren J, Standley KN, Takagi M, Maclean KH, Bernal-Mizrachi C, Muslin AJ, Kastan MB, Semenkovich CF. ATM-dependent suppression of stress signaling reduces vascular disease in metabolic syndrome. Cell Metab 2006; 4:377-89. [PMID: 17084711 DOI: 10.1016/j.cmet.2006.10.002] [Citation(s) in RCA: 188] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2006] [Revised: 09/18/2006] [Accepted: 10/05/2006] [Indexed: 10/23/2022]
Abstract
Metabolic syndrome is associated with insulin resistance and atherosclerosis. Here, we show that deficiency of one or two alleles of ATM, the protein mutated in the cancer-prone disease ataxia telangiectasia, worsens features of the metabolic syndrome, increases insulin resistance, and accelerates atherosclerosis in apoE-/- mice. Transplantation with ATM-/- as compared to ATM+/+ bone marrow increased vascular disease. Jun N-terminal kinase (JNK) activity was increased in ATM-deficient cells. Treatment of ATM+/+apoE-/- mice with low-dose chloroquine, an ATM activator, decreased atherosclerosis. In an ATM-dependent manner, chloroquine decreased macrophage JNK activity, decreased macrophage lipoprotein lipase activity (a proatherogenic consequence of JNK activation), decreased blood pressure, and improved glucose tolerance. Chloroquine also improved metabolic abnormalities in ob/ob and db/db mice. These results suggest that ATM-dependent stress pathways mediate susceptibility to the metabolic syndrome and that chloroquine or related agents promoting ATM activity could modulate insulin resistance and decrease vascular disease.
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Affiliation(s)
- Jochen G Schneider
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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52
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Weis SM, Lindquist JN, Barnes LA, Lutu-Fuga KM, Cui J, Wood MR, Cheresh DA. Cooperation between VEGF and beta3 integrin during cardiac vascular development. Blood 2006; 109:1962-70. [PMID: 17062734 PMCID: PMC1801042 DOI: 10.1182/blood-2005-10-038893] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
In the developing myocardium, vascular endothelial growth factor (VEGF)-dependent neovascularization occurs by division of existing vessels, a process that persists for several weeks following birth. During this remodeling phase, mRNA expression of beta3 integrin in the heart decreases significantly as vessel maturation progresses. However, in male mice lacking beta3, coronary capillaries fail to mature and continue to exhibit irregular endothelial thickness, endothelial protrusions into the lumen, and expanded cytoplasmic vacuoles. Surprisingly, this phenotype was not seen in female beta3-null mice. Enhanced VEGF signaling contributes to the beta3-null phenotype, because these vessels can be normalized by inhibitors of VEGF or Flk-1. Moreover, intravenous injection of VEGF induces a similar angiogenic phenotype in hearts of adult wild-type mice. These findings show a clear vascular phenotype in the hearts of mice lacking beta3 and suggest this integrin plays a critical role in coronary vascular development and the vascular response to VEGF.
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Affiliation(s)
- Sara M Weis
- Moores UCSD Cancer Center, University of California, San Diego, CA 92093-0803, USA
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53
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Rowe RK, Pekosz A. Bidirectional virus secretion and nonciliated cell tropism following Andes virus infection of primary airway epithelial cell cultures. J Virol 2006; 80:1087-97. [PMID: 16414986 PMCID: PMC1346943 DOI: 10.1128/jvi.80.3.1087-1097.2006] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2005] [Accepted: 11/02/2005] [Indexed: 02/02/2023] Open
Abstract
Hantavirus pulmonary syndrome (HPS) is an acute disease resulting from infection with any one of a number of New World hantaviruses. HPS has a mortality rate of 40% and, unlike many other severe respiratory diseases, often occurs in young, healthy adults. Infection is usually initiated after inhalation of rodent excreta containing virus particles, but human-to-human transmission has been documented. Postmortem tissue samples show high levels of viral antigen within the respiratory endothelium, but it is not clear how the virus can traverse the respiratory epithelium in order to initiate infection in the microvasculature. We have utilized Andes virus infection of primary, differentiated airway epithelial cells to investigate the ability of the virus to interact with and cross the respiratory epithelium. Andes virus infects the Clara and goblet cell populations but not the ciliated cells, and this infection pattern corresponds to the expression of beta(3) integrin, the viral receptor. The virus can infect via the apical or basolateral membrane, and progeny virus particles are secreted bidirectionally. There is no obvious cytopathology associated with infection, and beta(3) integrins do not appear to be critical for respiratory epithelial cell monolayer integrity. Our data suggest that hantavirus infection of the respiratory epithelium may play an important role in the early or prodrome phase of disease as well as serving as a source of virus involved in transmission.
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Affiliation(s)
- Regina K Rowe
- Department of Molecular Microbiology, Washington University School of Medicine, Campus Box 8230, 660 S. Euclid Avenue, St. Louis, MO 63110, USA
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54
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Abstract
The role of angiogenesis in atherosclerosis and other cardiovascular diseases has emerged as a major unresolved issue. Angiogenesis has attracted interest from opposite perspectives. Angiogenic cytokine therapy has been widely regarded as an attractive approach both for treating ischemic heart disease and for enhancing arterioprotective functions of the endothelium; conversely, a variety of studies suggest that neovascularization contributes to the growth of atherosclerotic lesions and is a key factor in plaque destabilization leading to rupture. Here, we critically review the evidence supporting a role for angiogenesis and angiogenic factors in atherosclerosis and neointima formation, emphasizing the problems raised by some of the landmark studies and the suitability of animal models of atherosclerosis and neointimal thickening for investigating the role of angiogenesis. Because many of the relevant studies have focused on the role of vascular endothelial growth factor (VEGF), we consider this work in the wider context of VEGF biology and in light of recent experience from clinical trials of VEGF and other angiogenic cytokines for ischemic heart disease. Also discussed are recent findings suggesting that, although angiogenesis may contribute to neointimal growth, it is not required for the initiation of intimal thickening. Our assessment of the evidence leads us to conclude that, although microvessels are a feature of advanced human atherosclerotic plaques, it remains unclear whether angiogenesis either plays a central role in the development of atherosclerosis or is responsible for plaque instability. Furthermore, current evidence from clinical trials of both proangiogenic and antiangiogenic therapies does not suggest that inhibition of angiogenesis is likely to be a viable therapeutic strategy for cardiovascular disease.
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Affiliation(s)
- Rohit Khurana
- Department of Medicine, University College London, London WC1E 6JJ, UK
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55
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Massberg S, Schürzinger K, Lorenz M, Konrad I, Schulz C, Plesnila N, Kennerknecht E, Rudelius M, Sauer S, Braun S, Kremmer E, Emambokus NR, Frampton J, Gawaz M. Platelet adhesion via glycoprotein IIb integrin is critical for atheroprogression and focal cerebral ischemia: an in vivo study in mice lacking glycoprotein IIb. Circulation 2005; 112:1180-8. [PMID: 16103235 DOI: 10.1161/circulationaha.105.539221] [Citation(s) in RCA: 108] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND The platelet glycoprotein (GP) IIb/IIIa integrin binds to fibrinogen and thereby mediates platelet aggregation. Here, we addressed the role of GP IIb for platelet adhesion and determined the relevance of platelet GP IIb for the processes of atherosclerosis and cerebral ischemia-reperfusion (I/R) injury. METHODS AND RESULTS GP IIb(-/-) mice were generated and bred with ApoE(-/-) animals to create GP IIb(-/-)ApoE(-/-) mice. Platelet adhesion to the mechanically injured or atherosclerotic vessel wall was monitored by in vivo video fluorescence microscopy. In the presence of GP IIb, vascular injury and early atherosclerosis induced platelet adhesion in the carotid artery (CA). In contrast, platelet adhesion was significantly reduced in the absence of GP IIb integrin (P<0.05). To address the contribution of platelet GP IIb to atheroprogression, we determined atherosclerotic lesion formation in the CA and aortic arch (AA) of GP IIb(+/+)ApoE(-/-) or GP IIb(-/-)ApoE(-/-) mice. Interestingly, the absence of GP IIb attenuated lesion formation in CA and AA, indicating that platelets, via GP IIb, contribute substantially to atherosclerosis. Next, we assessed the implication of GP IIb for cerebral I/R injury. We observed that after occlusion of the middle cerebral artery, the cerebral infarct size was drastically reduced in mice lacking GP IIb compared with wild-types. CONCLUSIONS These findings show for the first time in vivo that GP IIb not only mediates platelet aggregation but also triggers platelet adhesion to exposed extracellular matrices and dysfunctional endothelial cells. In a process strictly involving GP IIb, platelets, which are among the first blood cells to arrive at the scene of endothelial dysfunction, contribute essentially to atherosclerosis and cerebral I/R injury.
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Affiliation(s)
- Steffen Massberg
- Deutsches Herzzentrum and 1. Medizinische Klinik, Technische Universität München, Lazarettstrasse 36, D-80636 Munich, Germany.
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56
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Abstract
Platelets play a central role in hemostasis and thrombosis but also in the initiation of atherosclerosis, making platelet receptors and their intracellular signaling pathways important molecular targets for antithrombotic and anti-inflammatory therapy. Historically, much of the knowledge about hemostasis and thrombosis has been derived from patients suffering from bleeding and thrombotic disorders and the identification of the underlying molecular defects. In recent years, the availability of genetically modified mouse strains with defined defects in platelet function and the development of in vivo models to assess platelet-related physiologic and pathophysiologic processes have opened new ways to identify the individual roles and the interplay of platelet proteins in adhesion, activation, aggregation, secretion, and procoagulant activity in vitro and in vivo. This review will summarize key findings made by these approaches and discuss them in the context of human disease.
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Affiliation(s)
- B Nieswandt
- Rudolf Virchow Center, DFG Research Center for Experimental Biomedicine, University of Würzburg, Würzburg, Germany.
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58
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Abstract
During the past decade, interrelationships between inflammation and thrombosis have been the subject of extensive works, and it is now commonly recognized that inflammation (notably leucocyte recruitment) directly affects thrombosis, and that thrombosis also constitutes a pro-inflammatory event. This tight link is partly attributable to P-selectin, which is functional not only when expressed on the surface of activated platelets and endothelial cells, but also when shed, generating its soluble form, termed sP-selectin. In this review, we will provide an overview of the relative roles of the different compartments of P-selectin (platelet, endothelial cell, plasma) in haemostasis and vascular pathologies, and the potential therapeutic benefits achievable in targeting this molecule.
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Affiliation(s)
- Patrick André
- Portola Pharmaceuticals, South San Francisco, CA 94080, USA.
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59
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Antonov AS, Kolodgie FD, Munn DH, Gerrity RG. Regulation of macrophage foam cell formation by alphaVbeta3 integrin: potential role in human atherosclerosis. THE AMERICAN JOURNAL OF PATHOLOGY 2004; 165:247-58. [PMID: 15215180 PMCID: PMC1618536 DOI: 10.1016/s0002-9440(10)63293-2] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The accumulation of macrophage foam cells in atherosclerotic lesions is associated with both initiation and progression of this disease. Scavenger receptors CD36 and SRA are the primary receptors responsible for conversion of macrophages into foam cells. Integrin alphaVbeta3 plays a role in the differentiation of several cell types, but its involvement in the transition of macrophages into foam cells and the potential role of this receptor in atherosclerosis have not been examined. Using an in vitro model of single surface receptor activation by binding with an immobilized monoclonal antibody specific to alphaVbeta3 integrin we show that ligation of alphaVbeta3 integrin prevents differentiation of blood monocytes and macrophages into the foam cell phenotype via coordinate down-regulation of CD36 and SRA. This effect of alphaVbeta3 integrin ligation can be reproduced by contact with endothelial cells, whereas the inhibition of alphaVbeta3 receptor ligation restores the uptake of oxidized low-density lipoprotein. Moreover, we found that alphaVbeta3 integrin is readily detected in situ on macrophages in early and advanced atherosclerotic lesions and that in vitro exposure to oxidized low-density lipoprotein up-regulates alphaVbeta3 integrin expression. We hypothesize that alphaVbeta3 integrin regulates macrophage functional maturation into foam cells in a persistent manner, and therefore, by targeting alphaVbeta3 receptor it could potentially be possible to regulate progression of atherosclerosis in humans.
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Affiliation(s)
- Alexander S Antonov
- Department of Pathology, BF 231, Medical College of Georgia, 1120 15th Street, Augusta, GA 30912, USA.
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60
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Abstract
Platelets are blood cell fragments that originate from the cytoplasm of megakaryocytes in the bone marrow and circulate in blood to play a major role in the hemostatic process and in thrombus formation after an endothelial injury. Recent studies have provided insight into platelet functions in inflammation and atherosclerosis. A range of molecules, present on the platelet surface and/or stored in platelet granules, contributes to the cross-talk of platelets with other inflammatory cells during the vascular inflammation involved in the development and progression of atherosclerosis. This review discusses the nature of these molecules and the mechanisms involved in the participation of platelets in atherosclerosis, with emphasis on P-selectin, platelet-monocyte interactions, chemokines, and inflammatory cytokines.
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Affiliation(s)
- Yuqing Huo
- Cardiovascular Research Center and Department of Biomedical Engineering, University of Virginia Health Science Center, Box 801394, Charlottesville, VA 22908, USA.
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61
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Grenache DG, Coleman T, Semenkovich CF, Santoro SA, Zutter MM. Alpha2beta1 integrin and development of atherosclerosis in a mouse model: assessment of risk. Arterioscler Thromb Vasc Biol 2003; 23:2104-9. [PMID: 14512368 DOI: 10.1161/01.atv.0000097282.22923.ef] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE The alpha2beta1 integrin serves as a collagen or collagen/laminin receptor on many cell types, including endothelial cells and platelets. Many studies indicate that the alpha2beta1 integrin is a critical mediator of platelet adhesion to collagen. Epidemiologic studies suggest a direct correlation between the genetically determined platelet surface density of the alpha2beta1 integrin and the risk of thrombotic diseases, such as myocardial infarction and stroke, in the young, which are well-established complications of atherosclerosis. We have now used the alpha2beta1 integrin-deficient mouse to evaluate the contributions of the alpha2beta1 integrin to the development of atherosclerosis. METHODS AND RESULTS We generated wild-type (alpha2+/+) or alpha2beta1 integrin-deficient (alpha2-/-) mice that were also deficient in the apolipoprotein E (ApoE) gene (ApoE-/-) and compared atherosclerotic lesion development in alpha2+/+ ApoE-/- and alpha2-/- ApoE-/- mice that were fed a high-fat, cholesterol-containing diet for 6 or 15 weeks. Total lesional area did not differ significantly between the alpha2-null animals and the wild-type animals at either 6 or 15 weeks. CONCLUSIONS Our results suggest that risk for arterial thrombotic disease associated with high-level alpha2beta1 integrin expression is not attributable to enhanced development of atherosclerosis per se but may rather be a consequence of thrombotic complications at the plaques.
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Affiliation(s)
- David G Grenache
- Department of Pathology & Immunology, Washington University School of Medicine, St Louis, Mo, USA
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