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Antonsen KW, Hviid CVB, Hagensen MK, Sørensen BS, Møller HJ. Soluble PD-1 (sPD-1) is expressed in human macrophages. Cell Immunol 2021; 369:104435. [PMID: 34482260 DOI: 10.1016/j.cellimm.2021.104435] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 08/17/2021] [Accepted: 08/25/2021] [Indexed: 01/01/2023]
Abstract
The PD-1/PD-L1 axis plays a crucial role in regulating the anti-tumour immune response. A soluble PD-1 protein (sPD-1) has previously been observed, which could block the binding of PD-L1 to PD-1. Tumour associated macrophages are abundant in tumours, and evidence suggest they express PD-1. However, whether they also express sPD-1 remains unclear. The objective of this study was to investigate expression of sPD-1 in two in vitro models of human macrophages: THP-1 cells and monocyte-derived macrophages (MDM). Cells were polarised with either LPS + IFN-γ or IL-4 + IL-13 or left unpolarised. PD-1 and sPD-1 mRNAs were measured using droplet digital PCR, sPD-1 protein by electrochemiluminescence immunoassay and PD-1 by flow cytometry. sPD-1 mRNA was induced in both THP-1 cells and MDM after polarisation with LPS + IFN-γ, while IL-4 + IL-13 induced sPD-1 mRNA in MDM only. sPD-1 protein was measurable in culture supernatants. These findings show that macrophages can be induced to express sPD-1.
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Affiliation(s)
- Kristian W Antonsen
- Department of Clinical Biochemistry, Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, 8200 Aarhus N, Denmark
| | - Claus V B Hviid
- Department of Clinical Biochemistry, Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, 8200 Aarhus N, Denmark
| | - Mette K Hagensen
- Department of Clinical Biochemistry, Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, 8200 Aarhus N, Denmark
| | - Boe S Sørensen
- Department of Clinical Biochemistry, Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, 8200 Aarhus N, Denmark
| | - Holger J Møller
- Department of Clinical Biochemistry, Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, 8200 Aarhus N, Denmark.
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El Dabagh YSH, Mohanakumar S, Hagensen MK, Pedersen M. Remote Ischemic Conditioning in Rodents: Tourniquet vs. Cuff Occlusion. FASEB J 2018. [DOI: 10.1096/fasebj.2018.32.1_supplement.727.10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Sheyanth Mohanakumar
- Department of Cardiothoracic and Vascular SurgeryAarhus University HospitalAarhus NDenmark
| | - Mette K. Hagensen
- Department of Clinical BiochemistryAarhus University HospitalAarhus NDenmark
| | - Michael Pedersen
- Comparative Medicine LaboratoryAarhus University HospitalAarhus NDenmark
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Shim J, Poulsen CB, Hagensen MK, Larsen T, Heegaard PM, Christoffersen C, Bolund L, Schmidt M, Liu Y, Li J, Li R, Callesen H, Bentzon JF, Sørensen CB. Apolipoprotein E Deficiency Increases Remnant Lipoproteins and Accelerates Progressive Atherosclerosis, But Not Xanthoma Formation, in Gene-Modified Minipigs. ACTA ACUST UNITED AC 2017; 2:591-600. [PMID: 30062172 PMCID: PMC6058916 DOI: 10.1016/j.jacbts.2017.06.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Revised: 06/01/2017] [Accepted: 06/08/2017] [Indexed: 01/21/2023]
Abstract
APOE-deficient Yucatan minipigs were created by recombinant adeno-associated virus mediated gene targeting in porcine fibroblasts followed by somatic cell nuclear transfer. APOE−/− minipigs displayed increased plasma cholesterol and accumulation of APOB48-containing chylomicron remnants on low fat-diet, which was significantly accentuated upon feeding a high-fat, high-cholesterol diet. APOE−/− minipigs showed accelerated progressive atherosclerosis but not xanthoma formation indicating that remnant lipoproteinemia does not induce early lesions but is atherogenic in pre-existing atherosclerosis.
Deficiency of apolipoprotein E (APOE) causes familial dysbetalipoproteinemia in humans resulting in a higher risk of atherosclerotic disease. In mice, APOE deficiency results in a severe atherosclerosis phenotype, but it is unknown to what extent this is unique to mice. In this study, APOE was targeted in Yucatan minipigs. APOE−/− minipigs displayed increased plasma cholesterol and accumulation of apolipoprotein B-48–containing chylomicron remnants on low-fat diet, which was significantly accentuated upon feeding a high-fat, high-cholesterol diet. APOE−/− minipigs displayed accelerated progressive atherosclerosis but not xanthoma formation. This indicates that remnant lipoproteinemia does not induce early lesions but is atherogenic in pre-existing atherosclerosis.
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Key Words
- APOB, apolipoprotein B
- APOE, apolipoprotein E
- HFHC, high-fat high-cholesterol
- IDL, intermediate-density lipoprotein
- LAD, left anterior descending (coronary artery)
- LDL, low-density lipoprotein
- LDLR, low-density lipoprotein receptor
- LF, low-fat
- Neo, neomycin
- SMC, smooth muscle cell
- VLDL, very-low-density lipoprotein
- apolipoprotein E
- atherosclerosis
- cDNA, complementary DNA
- pig
- rAAV, recombinant adeno-associated virus
- remnant cholesterol dysbetalipoproteinemia
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Affiliation(s)
- Jeong Shim
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Department of Cardiology, Aarhus University Hospital, Aarhus, Denmark
| | - Christian Bo Poulsen
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Department of Cardiology, Aarhus University Hospital, Aarhus, Denmark
| | - Mette K. Hagensen
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Department of Cardiology, Aarhus University Hospital, Aarhus, Denmark
| | - Torben Larsen
- Department of Animal Science, Aarhus University, Aarhus, Denmark
| | - Peter M.H. Heegaard
- National Veterinary Institute, Technical University of Denmark, Lyngby, Denmark
| | | | - Lars Bolund
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Mette Schmidt
- Section for Veterinary Reproduction and Obstetrics, Department of Veterinary Clinical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Ying Liu
- Department of Animal Science, Aarhus University, Aarhus, Denmark
| | - Juan Li
- Department of Animal Science, Aarhus University, Aarhus, Denmark
| | - Rong Li
- Department of Animal Science, Aarhus University, Aarhus, Denmark
| | - Henrik Callesen
- Department of Animal Science, Aarhus University, Aarhus, Denmark
| | - Jacob F. Bentzon
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Department of Cardiology, Aarhus University Hospital, Aarhus, Denmark
- Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain
- Address for correspondence: Dr. Jacob F. Bentzon, CNIC, C/Melchor Fernández Almagro, 28029 Madrid, Spain.
| | - Charlotte B. Sørensen
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Department of Cardiology, Aarhus University Hospital, Aarhus, Denmark
- Dr. Charlotte B. Sørensen, Aarhus University, Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, DK-8200 Aarhus N, Denmark.
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Hagensen MK, Mortensen MB, Kjolby M, Stillits NL, Steffensen LB, Bentzon JF. Reply to "Bioinformatics analysis in type 1 diabetes increases retention of low-density lipoprotein in the atherosclerosis-prone area of the murine aorta". Atherosclerosis 2017; 263:428-429. [PMID: 28693830 DOI: 10.1016/j.atherosclerosis.2017.06.926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Accepted: 06/28/2017] [Indexed: 11/30/2022]
Affiliation(s)
- Mette K Hagensen
- Atherosclerosis Research Unit, Institute of Clinical Medicine, Department of Cardiology, Aarhus University Hospital, Skejby, Denmark.
| | - Martin Bødtker Mortensen
- Atherosclerosis Research Unit, Institute of Clinical Medicine, Department of Cardiology, Aarhus University Hospital, Skejby, Denmark
| | - Mads Kjolby
- Danish Diabetes Academy, Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Ninna L Stillits
- Atherosclerosis Research Unit, Institute of Clinical Medicine, Department of Cardiology, Aarhus University Hospital, Skejby, Denmark
| | - Lasse B Steffensen
- Atherosclerosis Research Unit, Institute of Clinical Medicine, Department of Cardiology, Aarhus University Hospital, Skejby, Denmark; Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Jacob F Bentzon
- Atherosclerosis Research Unit, Institute of Clinical Medicine, Department of Cardiology, Aarhus University Hospital, Skejby, Denmark
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Mortensen MB, Nilsson L, Larsen TG, Espeseth E, Bek M, Bjørklund MM, Hagensen MK, Wolff A, Gunnersen S, Füchtbauer EM, Boedtkjer E, Bentzon JF. Prior renovascular hypertension does not predispose to atherosclerosis in mice. Atherosclerosis 2016; 249:157-63. [PMID: 27100924 DOI: 10.1016/j.atherosclerosis.2016.03.030] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Revised: 03/14/2016] [Accepted: 03/22/2016] [Indexed: 11/19/2022]
Abstract
BACKGROUND Hypertension is a major risk factor for development of atherosclerotic cardiovascular disease (ASCVD). Although lowering blood pressure with antihypertensive drugs reduces the increased risk of ASCVD, residual increased risk still remains, suggesting that hypertension may cause chronic changes that promote atherosclerosis. Thus, we tested the hypothesis that hypertension increases the susceptibility to atherosclerosis in mice even after a period of re-established normotension. METHODS We used the 2-kidney, 1-clip (2K1C) technique to induce angiotensin-driven renovascular hypertension, and overexpression of the proprotein convertase subtilisin/kexin type 9 (PCSK9) gene to cause severe hypercholesterolemia and atherosclerosis. RESULTS First, we performed 2K1C (n = 8) or sham surgery (n = 9) in PCSK9 transgenic mice before they were fed a high fat diet for 14 weeks. As expected, 2K1C did not affect cholesterol levels, but induced cardiac hypertrophy and significantly increased the atherosclerotic lesion area compared to sham mice (1.8 fold, p < 0.01). Next, we performed 2K1C (n = 13) or sham surgery (n = 14) in wild-type mice but removed the clipped/sham-operated kidney after 10 weeks to eliminate hypertension, and subsequently induced hypercholesterolemia by way of adeno-associated virus-mediated hepatic gene transfer of PCSK9 combined with high-fat diet. After 14 weeks of hypercholesterolemia, atherosclerotic lesion areas were not significantly different in mice with or without prior 2K1C hypertension (0.95 fold, p = 0.35). CONCLUSION Renovascular hypertension in mice does not induce pro-atherogenic changes that persist beyond the hypertensive phase. These results indicate that hypertension only promotes atherogenesis when coinciding temporally with hypercholesterolemia.
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Affiliation(s)
- Martin Bødtker Mortensen
- Department of Clinical Medicine, Aarhus University, Denmark; Department of Cardiology, Aarhus University Hospital, Denmark.
| | - Line Nilsson
- Department of Clinical Medicine, Aarhus University, Denmark
| | - Tore G Larsen
- Department of Clinical Medicine, Aarhus University, Denmark
| | | | - Marie Bek
- Department of Clinical Medicine, Aarhus University, Denmark
| | - Martin M Bjørklund
- Department of Clinical Medicine, Aarhus University, Denmark; Department of Cardiology, Aarhus University Hospital, Denmark
| | - Mette K Hagensen
- Department of Clinical Medicine, Aarhus University, Denmark; Department of Cardiology, Aarhus University Hospital, Denmark
| | - Anne Wolff
- Department of Clinical Medicine, Aarhus University, Denmark
| | - Stine Gunnersen
- Department of Clinical Medicine, Aarhus University, Denmark; Department of Cardiology, Aarhus University Hospital, Denmark
| | | | | | - Jacob F Bentzon
- Department of Clinical Medicine, Aarhus University, Denmark; Department of Cardiology, Aarhus University Hospital, Denmark
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Hagensen MK, Mortensen MB, Kjolby M, Bentzon JF, Gregersen S. Abstract 591: Increased Retention of LDL From Type 1 Diabetic Patients in an Atherosclerosis-prone Area of the Murine Arterial Wall. Arterioscler Thromb Vasc Biol 2015. [DOI: 10.1161/atvb.35.suppl_1.591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background:
Individuals with type 1 diabetes mellitus (T1DM) are at high risk of developing atherosclerotic cardiovascular disease but the exact mechanisms by which T1DM accelerates atherosclerosis remain unknown. In the present study, we investigated whether modifications of low density lipoprotein (LDL) in T1DM patients causes an increased retention of LDL in the vessel wall.
Methods and Results:
Fluorescently-labeled human LDL from either T1DM patients (n=10) or healthy non-diabetic subjects (control) (n=7) was injected into mice with T1DM. After 24 hours, when LDL was completely cleared from the circulation, cryosections of the inner curvature of the aortic arch (i.e. atherosclerosis prone area) was analyzed for retained LDL by fluorescence microscopy (Red in figure A). We found significantly more retained T1DM LDL (n=10) compared to LDL from non-diabetic subjects (n=7) with a fold change of 4.35 (p < 0.05). Nuclear magnetic resonance (NMR) spectroscopy analysis of LDL revealed no differences in the level of the atherogenic small dense LDL between T1DM LDL (274.4±47.8 nmol/L) and non-diabetic LDL (263.8±55.3 nmol/L). Using LiCor Odyssey infrared imaging scanning of the whole aorta en face, we found that in vitro glycation of LDL from a non-diabetic subject significantly increased retention (n=8) compared to LDL prepared similarly but without glucose (n=8), with a fold change of 8.87 (p < 0.001) (Figure B).
Conclusion:
LDL from patients with T1DM as well as ex vivo glycated LDL showed increased retention at atherosclerosis-prone sites in the arterial wall of mice. This may contribute to the accelerated development of atherosclerosis in T1DM.
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Affiliation(s)
- Mette K Hagensen
- Atherosclerosis Rsch Unit, Dept of Clinical Medicine and Dept of Cardiology, Aarhus Univ, Aarhus N, Denmark
| | - Martin B Mortensen
- Atherosclerosis Rsch Unit, Dept of Clinical Medicine and Dept of Cardiology, Aarhus Univ, Aarhus N, Denmark
| | - Mads Kjolby
- Dept of Biomedicine, Aarhus Univ, Aarhus, Denmark
| | - Jacob F Bentzon
- Atherosclerosis Rsch Unit, Dept of Clinical Medicine and Dept of Cardiology, Aarhus Univ, Aarhus N, Denmark
| | - Soeren Gregersen
- Dept of Endocrinology and Internal Medicine, Aarhus Univ Hosp, Aarhus, Denmark
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Abstract
For more than a decade, a prevailing hypothesis in research related to arterial disease has been that circulating endothelial progenitor cells (EPCs) provide protection by their innate ability to replace dysfunctional or damaged endothelium. This paradigm has led to extensive investigation of EPCs in the hope of finding therapeutic targets to control their homing and differentiation. However, from the very beginning, the nomenclature and the phenotype of EPCs have been subject to controversy and there are currently no specific markers that can unambiguously identify these cells. Moreover, many of the initial observations that EPCs differentiate to endothelial cells in the course of arterial disease have been criticized for methodological problems. The present review discusses the contrasting experimental evidence as to the role of EPCs in contributing to relining of the endothelium and highlights some of the methodological pitfalls and terminological ambiguities that confuse the field.
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Affiliation(s)
- Mette K Hagensen
- Atherosclerosis Research Unit, Institute of Clinical Medicine and Department of Cardiology, Aarhus University Hospital, Brendstrupgaardsvej, Skejby, Aarhus N, Denmark.
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Hagensen MK, Raarup MK, Mortensen MB, Thim T, Nyengaard JR, Falk E, Bentzon JF. Circulating endothelial progenitor cells do not contribute to regeneration of endothelium after murine arterial injury. Cardiovasc Res 2011; 93:223-31. [PMID: 22012957 DOI: 10.1093/cvr/cvr278] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
AIMS Endothelial regeneration after vascular injury, including percutaneous coronary intervention, is essential for vascular homeostasis and inhibition of neointima formation. Circulating endothelial progenitor cells (EPCs) have been implicated to contribute by homing and differentiating into endothelial cells (ECs). We tested this theory in a murine arterial injury model using carotid artery transplants and fluorescent reporter mice. METHODS AND RESULTS Wire-injured carotid artery segments from wild-type mice were transplanted into TIE2-GFP transgenic mice expressing green fluorescent protein (GFP) in ECs. We found that the endothelium regenerated with GFP(+) ECs as a function of time, evolving from the anastomosis sites towards the centre of the transplant. A migration front of ECs at Day 7 was verified by scanning electron microscopy and by bright-field microscopy using recipient TIE2-lacZ mice with endothelial β-galactosidase expression. These experiments indicated migration of flanking ECs rather than homing of circulating cells as the underlying mechanism. To confirm this, we interposed non-injured wild-type carotid artery segments between the denuded transplant and the TIE2-GFP recipient mouse. Among 1186 ECs identified in re-endothelialized transplants (n= 5) by staining for von Willebrand Factor or vascular endothelial-cadherin, we did not find any blood-derived (GFP(+)) cells. CONCLUSION Endothelial regeneration after vascular injury did not involve circulating EPCs but was mediated solely by migration of ECs from the adjacent healthy endothelium.
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Affiliation(s)
- Mette K Hagensen
- Atherosclerosis Research Unit, Department of Cardiology, Institute of Clinical Medicine, Aarhus University Hospital, Skejby, Denmark.
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Hagensen MK, Shim J, Falk E, Bentzon JF. Flanking recipient vasculature, not circulating progenitor cells, contributes to endothelium and smooth muscle in murine allograft vasculopathy. Arterioscler Thromb Vasc Biol 2011; 31:808-13. [PMID: 21233450 DOI: 10.1161/atvbaha.110.221184] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
OBJECTIVE The prevailing view assumes that circulating endothelial and smooth muscle progenitor cells participate in allograft vasculopathy (AV), although the seminal studies in the field were not designed to distinguish between circulating and migrating cells of recipient origin. We developed a double-transplantation technique to overcome this problem and reinvestigated the origin of endothelial cells (ECs) and smooth muscle cells (SMCs) in murine AV. METHODS AND RESULTS Carotid artery segments from BALB/c mice were allografted to apolipoprotein E(-/-) B6 mice with or without a "flanking" isograft interpositioned between the allograft and the recipient artery. Either recipient mice or interpositioned isografts expressed enhanced green fluorescent protein, and consequently, cells migrating into the allograft from the flanking vasculature could easily be tracked and distinguished from recruited circulating cells. Without immunosuppression, allograft donor cells vanished as expected, and AV developed by replacement and accumulation of ECs and SMCs of recipient origin. The double transplantation models revealed that all ECs and SMCs in AV had migrated into the allograft from the flanking vasculature without any contribution from putative progenitor cells in the blood. CONCLUSIONS Migrating cells from the flanking vasculature, not circulating progenitor cells, are the source of recipient-derived ECs and SMCs in murine AV.
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Affiliation(s)
- Mette K Hagensen
- Atherosclerosis Research Unit, Department of Cardiology, Institute of Clinical Medicine, Aarhus University Hospital, Skejby, Denmark.
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Hagensen MK, Abe AS, Wang T. Baroreflex control of heart rate in the broad-nosed caiman Caiman latirostris is temperature dependent. Comp Biochem Physiol A Mol Integr Physiol 2010; 156:458-62. [DOI: 10.1016/j.cbpa.2010.03.028] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2010] [Revised: 03/23/2010] [Accepted: 03/27/2010] [Indexed: 10/19/2022]
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Abstract
BACKGROUND It has been reported that circulating endothelial progenitor cells (EPCs) home to and differentiate into endothelial cells after various kinds of arterial injury. By inference, EPCs are also proposed to be important in the most important arterial disease, atherosclerosis, but the evidence for this theory is not clear. In the present study, we assessed the contribution of circulating EPCs to plaque endothelium in apolipoprotein E-deficient (apoE(-/-)) mice. METHODS AND RESULTS To investigate whether EPCs in the circulating blood are a source of plaque endothelial cells during atherogenesis, we examined plaques in lethally irradiated apoE(-/-) mice reconstituted with bone marrow cells from enhanced green fluorescent protein (eGFP) transgenic apoE(-/-) mice and plaques induced in segments of common carotid artery transplanted from apoE(-/-) mice into eGFP(+)apoE(-/-) mice. Among 4232 endothelial cells identified by a cell-type-specific marker (von Willebrand factor) and analyzed by high-resolution microscopy, we found only 1 eGFP(+). Using the Y chromosome to track cells after sex-mismatched transplants yielded similar results. To investigate whether circulating EPCs are involved in plaque reendothelialization after plaque disruption and superimposed thrombosis, we produced mechanical plaque disruptions in carotid bifurcation plaques in old lethally irradiated apoE(-/-) mice reconstituted with eGFP(+)apoE(-/-) bone marrow cells and carotid bifurcation plaques transplanted from old apoE(-/-) mice into eGFP(+)apoE(-/-) mice. Only 1 eGFP(+) endothelial cell was found among 3170 analyzed. CONCLUSIONS Circulating EPCs rarely, if ever, contribute to plaque endothelium in apoE(-/-) mice. These findings bring into question the prevailing theory that circulating EPCs play an important role in atherogenesis.
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Affiliation(s)
- Mette K Hagensen
- MSc, Atherosclerosis Research Unit, Institute of Clinical Medicine and Department of Cardiology, Aarhus University Hospital, Skejby, Brendstrupgaardsvej 100, 8200 Aarhus N, Denmark.
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Abstract
SUMMARYThe reptilian heart consists of a thick inner spongy myocardium that derives its oxygen and nutrient supply directly from the blood within the ventricular cavity, which is surrounded by a thin outer compact layer supplied by coronary arteries. The functional importance of these coronary arteries remains unknown. In the present study we investigate the effects of permanent coronary artery occlusion in the South American rattlesnake (Crotalus durissus) on the ability to maintain heart rate and blood pressure at rest and during short term activity. We used colored silicone rubber(Microfil) to identify the coronary artery distribution and interarterial anastomoses. The coronary circulation was occluded and the snakes were then kept for 4 days at 30°C. Microfil injections verified that virtually all coronary arteries had successfully been occluded, but also made visible an extensive coronary supply to the outer compact layer in untreated snakes. Electrocardiogram (ECG), blood pressure (Psys) and heart rate (fH) were measured at rest and during enforced activity at day 1 and 4. Four days after occlusion of the coronary circulation, the snakes could still maintain a Psys and fH of 5.2±0.2 kPa and 58.2±2.2 beats min–1, respectively, during activity and the ECG was not affected. This was not different from sham-operated snakes. Thus, while the outer compact layer of the rattlesnake heart clearly has an extensive coronary supply, rattlesnakes sustain a high blood pressure and heart rate during activity without coronary artery blood supply.
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Affiliation(s)
- Mette K. Hagensen
- Department of Zoophysiology, Institute of Biological Sciences, University of Aarhus, Denmark
- Department of Cardiology, Research Unit, Aarhus University Hospital (Skejby),Denmark
| | - Augusto S. Abe
- Departamento de Zoologia, Centro de Aquicultura, UNESP, Rio Claro, São Paulo, Brazil
| | - Erling Falk
- Department of Cardiology, Research Unit, Aarhus University Hospital (Skejby),Denmark
| | - Tobias Wang
- Department of Zoophysiology, Institute of Biological Sciences, University of Aarhus, Denmark
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Abstract
Plaque rupture precipitates approximately 75% of all fatal coronary thrombi. Therefore, the plaque prone to rupture is the primary focus of this review. The lipid-rich core and fibrous cap are pivotal in the understanding of plaque rupture. Plaque rupture is a localized process within the plaque caused by degradation of a tiny fibrous cap rather than by diffuse inflammation of the plaque. Atherosclerosis is a multifocal disease, but plaques prone to rupture seem to be oligofocal at most.
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Affiliation(s)
- T Thim
- Atherosclerosis Research Unit, Department of Cardiology, Aarhus University Hospital (Skejby), Aarhus, Denmark.
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