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Hough RF, Alvira CM, Bastarache JA, Erzurum SC, Kuebler WM, Schmidt EP, Shimoda LA, Abman SH, Alvarez DF, Belvitch P, Bhattacharya J, Birukov KG, Chan SY, Cornfield DN, Dudek SM, Garcia JGN, Harrington EO, Hsia CCW, Islam MN, Jonigk DD, Kalinichenko VV, Kolb TM, Lee JY, Mammoto A, Mehta D, Rounds S, Schupp JC, Shaver CM, Suresh K, Tambe DT, Ventetuolo CE, Yoder MC, Stevens T, Damarla M. Studying the Pulmonary Endothelium in Health and Disease: An Official American Thoracic Society Workshop Report. Am J Respir Cell Mol Biol 2024; 71:388-406. [PMID: 39189891 PMCID: PMC11450313 DOI: 10.1165/rcmb.2024-0330st] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2024] [Indexed: 08/28/2024] Open
Abstract
Lung endothelium resides at the interface between the circulation and the underlying tissue, where it senses biochemical and mechanical properties of both the blood as it flows through the vascular circuit and the vessel wall. The endothelium performs the bidirectional signaling between the blood and tissue compartments that is necessary to maintain homeostasis while physically separating both, facilitating a tightly regulated exchange of water, solutes, cells, and signals. Disruption in endothelial function contributes to vascular disease, which can manifest in discrete vascular locations along the artery-to-capillary-to-vein axis. Although our understanding of mechanisms that contribute to endothelial cell injury and repair in acute and chronic vascular disease have advanced, pathophysiological mechanisms that underlie site-specific vascular disease remain incompletely understood. In an effort to improve the translatability of mechanistic studies of the endothelium, the American Thoracic Society convened a workshop to optimize rigor, reproducibility, and translation of discovery to advance our understanding of endothelial cell function in health and disease.
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Yadav D, Conner JA, Wang Y, Saunders TL, Ubogu EE. A novel inducible von Willebrand Factor Cre recombinase mouse strain to study microvascular endothelial cell-specific biological processes in vivo. Vascul Pharmacol 2024; 155:107369. [PMID: 38554988 DOI: 10.1016/j.vph.2024.107369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 03/17/2024] [Accepted: 03/27/2024] [Indexed: 04/02/2024]
Abstract
Mouse models are invaluable to understanding fundamental mechanisms in vascular biology during development, in health and different disease states. Several constitutive or inducible models that selectively knockout or knock in genes in vascular endothelial cells exist; however, functional and phenotypic differences exist between microvascular and macrovascular endothelial cells in different organs. In order to study microvascular endothelial cell-specific biological processes, we developed a Tamoxifen-inducible von Willebrand Factor (vWF) Cre recombinase mouse in the SJL background. The transgene consists of the human vWF promoter with the microvascular endothelial cell-selective 734 base pair sequence to drive Cre recombinase fused to a mutant estrogen ligand-binding domain [ERT2] that requires Tamoxifen for activity (CreERT2) followed by a polyadenylation (polyA) signal. We initially observed Tamoxifen-inducible restricted bone marrow megakaryocyte and sciatic nerve microvascular endothelial cell Cre recombinase expression in offspring of a mixed strain hemizygous C57BL/6-SJL founder mouse bred with mT/mG mice, with >90% bone marrow megakaryocyte expression efficiency. Founder mouse offspring were backcrossed to the SJL background by speed congenics, and intercrossed for >10 generations to develop hemizygous Tamoxifen-inducible vWF Cre recombinase (vWF-iCre/+) SJL mice with stable transgene insertion in chromosome 1. Microvascular endothelial cell-specific Cre recombinase expression occurred in the sciatic nerves, brains, spleens, kidneys and gastrocnemius muscles of adult vWF-iCre/+ SJL mice bred with Ai14 mice, with retained low level bone marrow and splenic megakaryocyte expression. This novel mouse strain would support hypothesis-driven mechanistic studies to decipher the role(s) of specific genes transcribed by microvascular endothelial cells during development, as well as in physiologic and pathophysiologic states in an organ- and time-dependent manner.
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Affiliation(s)
- Dinesh Yadav
- Neuromuscular Immunopathology Research Laboratory, Division of Neuromuscular Disease, Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Jeremy A Conner
- Neuromuscular Immunopathology Research Laboratory, Division of Neuromuscular Disease, Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Yimin Wang
- Neuromuscular Immunopathology Research Laboratory, Division of Neuromuscular Disease, Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Thomas L Saunders
- Transgenic Animal Model Core, University of Michigan, Ann Arbor, MI, USA
| | - Eroboghene E Ubogu
- Neuromuscular Immunopathology Research Laboratory, Division of Neuromuscular Disease, Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA.
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Abstract
PURPOSE OF REVIEW The use of genetic models has facilitated the study of the origins and mechanisms of vascular disease. Mouse models have been developed to specifically target endothelial cell populations, with the goal of pinpointing when and where causative mutations wreck their devastating effects. Together, these approaches have propelled the development of therapies by providing an in-vivo platform to evaluate diagnoses and treatment options. This review summarizes the most widely used mouse models that have facilitated the study of vascular disease, with a focus on mouse models of vascular malformations and the road ahead. RECENT FINDINGS Over the past 3 decades, the vascular biology scientific community has been steadily generating a powerful toolkit of useful mouse lines that can be used to tightly regulate gene ablation, or to express transgenic genes, in the murine endothelium. Some of these models inducibly (constitutively) alter gene expression across all endothelial cells, or within distinct subsets, by expressing either Cre recombinase (or inducible versions such as CreERT), or the tetracycline controlled transactivator protein tTA (or rtTA). This now relatively standard technology has been used to gain cutting edge insights into vascular disorders, by allowing in-vivo modeling of key molecular pathways identified as dysregulated across the vast spectrum of vascular anomalies, malformations and dysplasias. However, as sequencing of human patient samples expands, the number of interesting candidate molecular culprits keeps increasing. Consequently, there is now a pressing need to create new genetic mouse models to test hypotheses and to query mechanisms underlying vascular disease. SUMMARY The current review assesses the collection of mouse driver lines that have been instrumental is identifying genes required for blood vessel formation, remodeling, maintenance/quiescence and disease. In addition, the usefulness of these driver lines is underscored here by cataloguing mouse lines developed to experimentally assess the role of key candidate genes in vascular malformations. Despite this solid and steady progress, numerous new candidate vascular malformation genes have recently been identified for which no mouse model yet exists.
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Affiliation(s)
- Ondine Cleaver
- Department of Molecular Biology, Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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Lee H. Rapid Way to Generate Mouse Models for In Vivo Studies of the Endothelium. J Lipid Atheroscler 2020; 10:24-41. [PMID: 33537251 PMCID: PMC7838514 DOI: 10.12997/jla.2021.10.1.24] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 10/10/2020] [Accepted: 11/05/2020] [Indexed: 11/09/2022] Open
Abstract
A single layer of squamous endothelial cells (ECs), the endothelium, regulates the flow of substance and fluid into and out of a tissue. The endothelium is also involved in vasculogenesis, the formation of new blood vessels, which is a crucial process for organ development in the embryo and fetus. Because most murine mutations of genes involved in EC development cause early embryo lethality, EC-specific conditional knockout (cKO) mouse models are indispensable for in vivo studies. cKO mice including the floxed allele can be generated through advanced approaches including embryonic stem cell-mediated gene targeting or the CRISPR/Cas system. EC-specific mouse models can be generated through further breeding of floxed mice with a Cre driver line, the latest information of which is available in the Jackson Cre Repository or the EUCOMMTOOLS project. Because it takes a long time (generally 1-2 years) to generate EC-specific mouse models, researchers must thoroughly design and plan a breeding strategy before full-scale mouse experiments, which saves time and money for in vivo study. In summary, revolutionary technical advances in embryo manipulation and assisted reproduction technologies have made it easier to generate EC-specific mouse models, which have been used as essential resources for in vivo studies of the endothelium.
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Affiliation(s)
- Ho Lee
- Graduate School of Cancer Science and Policy, Research Institute, National Cancer Center, Goyang, Korea
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Goldthorpe H, Jiang JY, Taha M, Deng Y, Sinclair T, Ge CX, Jurasz P, Turksen K, Mei SHJ, Stewart DJ. Occlusive lung arterial lesions in endothelial-targeted, fas-induced apoptosis transgenic mice. Am J Respir Cell Mol Biol 2016; 53:712-8. [PMID: 25879383 DOI: 10.1165/rcmb.2014-0311oc] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Pulmonary arterial hypertension (PAH) is a lethal disease that is characterized by functional and structural abnormalities involving distal pulmonary arterioles that result in increased pulmonary vascular resistance and ultimately right heart failure. In experimental models of pulmonary hypertension, endothelial cell (EC) apoptosis is a necessary trigger for the development of obliterative lung arteriopathy, inducing the emergence of hyperproliferative and apoptosis-resistant vascular cells. However, it has not been established whether EC apoptosis is sufficient for the induction of complex lung arteriolar lesions. We generated a conditional transgenic system in mice to test the hypothesis that lung endothelial cell apoptosis is sufficient to induce a PAH phenotype. The Fas-induced apoptosis (FIA) construct was expressed under the control of endothelial-specific Tie2 promoter (i.e., EFIA mice), and administration of a small molecule dimerizing agent, AP20187, resulted in modest pulmonary hypertension, which was associated with obliterative vascular lesions localized to distal lung arterioles in a proportion of transgenic mice. These lesions were characterized by proliferating cells, predominantly CD68 macrophages. Although endothelial cell apoptosis was also seen in the kidney, evidence of subsequent arteriopathy was seen only in the lung. This model provides direct evidence that lung endothelial cell apoptosis acts as a trigger to initiate a PAH phenotype and provides initial insight into the potential mechanisms that underlie a lung-specific arterial response to endothelial injury.
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Affiliation(s)
- Heather Goldthorpe
- 1 Sinclair Centre for Regenerative Medicine, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.,2 Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada; and
| | - Jin-Yi Jiang
- 1 Sinclair Centre for Regenerative Medicine, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.,2 Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada; and
| | - Mohamad Taha
- 1 Sinclair Centre for Regenerative Medicine, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.,2 Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada; and
| | - Yupu Deng
- 1 Sinclair Centre for Regenerative Medicine, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
| | - Tammy Sinclair
- 1 Sinclair Centre for Regenerative Medicine, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
| | - Cindy X Ge
- 1 Sinclair Centre for Regenerative Medicine, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
| | - Paul Jurasz
- 3 Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Kursad Turksen
- 1 Sinclair Centre for Regenerative Medicine, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.,2 Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada; and
| | - Shirley H J Mei
- 1 Sinclair Centre for Regenerative Medicine, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
| | - Duncan J Stewart
- 1 Sinclair Centre for Regenerative Medicine, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.,2 Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada; and
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Endothelial Expression of Scavenger Receptor Class B, Type I Protects against Development of Atherosclerosis in Mice. BIOMED RESEARCH INTERNATIONAL 2015; 2015:607120. [PMID: 26504816 PMCID: PMC4609362 DOI: 10.1155/2015/607120] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Revised: 07/10/2015] [Accepted: 07/24/2015] [Indexed: 11/23/2022]
Abstract
The role of scavenger receptor class B, type I (SR-BI) in endothelial cells (EC) was examined in several novel transgenic mouse models expressing SR-BI in endothelium of mice with normal C57Bl6/N, apoE-KO, or Scarb1-KO backgrounds. Mice were also created expressing SR-BI exclusively in endothelium and liver. Endothelial expression of the Tie2-Scarb1 transgene had no significant effect on plasma lipoprotein levels in mice on a normal chow diet but on an atherogenic diet, significantly decreased plasma cholesterol levels, increased plasma HDL cholesterol (HDL-C) levels, and protected mice against atherosclerosis. In 8-month-old apoE-KO mice fed a normal chow diet, the Tie2-Scarb1 transgene decreased aortic lesions by 24%. Mice expressing SR-BI only in EC and liver had a 1.5 ± 0.1-fold increase in plasma cholesterol compared to mice synthesizing SR-BI only in liver. This elevation was due mostly to increased HDL-C. In EC culture studies, SR-BI was found to be present in both basolateral and apical membranes but greater cellular uptake of cholesterol from HDL was found in the basolateral compartment. In summary, enhanced expression of SR-BI in EC resulted in a less atherogenic lipoprotein profile and decreased atherosclerosis, suggesting a possible role for endothelial SR-BI in the flux of cholesterol across EC.
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Suarez J, Wang H, Scott BT, Ling H, Makino A, Swanson E, Brown JH, Suarez JA, Feinstein S, Diaz-Juarez J, Dillmann WH. In vivo selective expression of thyroid hormone receptor α1 in endothelial cells attenuates myocardial injury in experimental myocardial infarction in mice. Am J Physiol Regul Integr Comp Physiol 2014; 307:R340-6. [PMID: 24848360 DOI: 10.1152/ajpregu.00449.2013] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Ischemic heart disease (IHD) is the single most common cause of death. New approaches to enhance myocardial perfusion are needed to improve outcomes for patients with IHD. Thyroid hormones (TH) are known to increase blood flow; however, their usefulness for increasing perfusion in IHD is limited because TH accelerates heart rate, which can be detrimental. Therefore, selective activation of TH effects is desirable. We hypothesized that cell-type-specific TH receptor (TR) expression can increase TH action in the heart, while avoiding the negative consequences of TH treatment. We generated a binary transgenic (BTG) mouse that selectively expresses TRα1 in endothelial cells in a tetracycline-inducible fashion. In BTG mice, endothelial TRα1 protein expression was increased by twofold, which, in turn, increased coronary blood flow by 77%, coronary conductance by 60%, and coronary reserve by 47% compared with wild-type mice. Systemic blood pressure was decreased by 20% in BTG mice after TRα1 expression. No effects on heart rate were observed. Endothelial TRα1 expression activated AKT/endothelial nitric oxide synthase pathway and increased A2AR adenosine receptor. Furthermore, hearts from BTG mice overexpressing TRα1 that were submitted to 20 min ischemia and 20 min reperfusion showed a 20% decline in left ventricular pressure (LVP) compared with control mice where LVP was decreased by 42%. Studies using an infarction mouse model demonstrated that endothelial overexpression of TRα1 decreased infarct size by 45%. In conclusion, selective expression of TRα1 in endothelial cells protects the heart against injury after an ischemic insult and does not result in adverse cardiac or systemic effects.
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Affiliation(s)
- Jorge Suarez
- Department of Medicine, University of California, San Diego, California
| | - Hong Wang
- Department of Medicine, University of California, San Diego, California
| | - Brian T Scott
- Department of Medicine, University of California, San Diego, California
| | - Haiyun Ling
- Department of Pharmacology, University of California, San Diego, California; and
| | - Ayako Makino
- Department of Medicine, University of California, San Diego, California
| | - Eric Swanson
- Department of Medicine, University of California, San Diego, California
| | - Joan Heller Brown
- Department of Pharmacology, University of California, San Diego, California; and
| | - Jorge A Suarez
- Department of Medicine, University of California, San Diego, California
| | - Shera Feinstein
- Department of Medicine, University of California, San Diego, California
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Lee D, Shenoy S, Nigatu Y, Plotkin M. Id proteins regulate capillary repair and perivascular cell proliferation following ischemia-reperfusion injury. PLoS One 2014; 9:e88417. [PMID: 24516656 PMCID: PMC3917915 DOI: 10.1371/journal.pone.0088417] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Accepted: 01/07/2014] [Indexed: 01/08/2023] Open
Abstract
Acute kidney injury (AKI) results in microvascular damage that if not normally repaired, may lead to fibrosis. The Id1 and 3 proteins have a critical role in promoting angiogenesis during development, tumor growth and wound repair by functioning as dominant negative regulators of bHLH transcription factors. The goal of this study was to determine if Id proteins regulate microvascular repair and remodeling and if increased Id1 expression results in decreased capillary loss following AKI. The effect of changes in Id expression in vivo was examined using Id1−/−, Id3RFP/+ (Id1/Id3 KO) and Tek (Tie2)-rtTA, TRE-lacz/TRE Id1 (TRE Id1) mice with doxycycline inducible endothelial Id1 and β-galactosidase expression. Id1 and 3 were co-localized in endothelial cells in normal adult kidneys and protein levels were increased at day 3 following ischemia-reperfusion injury (IRI) and contralateral nephrectomy. Id1/Id3 KO mice had decreased baseline capillary density and pericyte coverage and increased tubular damage following IRI but decreased interstitial cell proliferation and fibrosis compared with WT littermates. No compensatory increase in kidney size occurred in KO mice resulting in increased creatinine compared with WT and TRE Id1 mice. TRE Id1 mice had no capillary rarefaction within 1 week following IRI in comparison with WT littermates. TRE Id1 mice had increased proliferation of PDGFRβ positive interstitial cells and medullary collagen deposition and developed capillary rarefaction and albuminuria at later time points. These differences were associated with increased Angiopoietin 1 (Ang1) and decreased Ang2 expression in TRE Id1 mice. Examination of gene expression in microvascular cells isolated from WT, Id1/Id3 KO and TRE Id1 mice showed increased Ang1 and αSMA in Id1 overexpressing cells and decreased pericyte markers in cells from KO mice. These results suggest that increased Id levels following AKI result in microvascular remodeling associated with increased fibrosis.
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Affiliation(s)
- David Lee
- Department of Medicine, Renal Research Division, New York Medical College, Valhalla, New York, United States of America
| | - Shantheri Shenoy
- Department of Medicine, Renal Research Division, New York Medical College, Valhalla, New York, United States of America
| | - Yezina Nigatu
- Department of Medicine, Renal Research Division, New York Medical College, Valhalla, New York, United States of America
| | - Matt Plotkin
- Department of Medicine, Renal Research Division, New York Medical College, Valhalla, New York, United States of America
- * E-mail:
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Endothelial PGC-1α mediates vascular dysfunction in diabetes. Cell Metab 2014; 19:246-58. [PMID: 24506866 PMCID: PMC4040246 DOI: 10.1016/j.cmet.2013.12.014] [Citation(s) in RCA: 127] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2013] [Revised: 10/08/2013] [Accepted: 12/10/2013] [Indexed: 12/26/2022]
Abstract
Endothelial dysfunction is a central hallmark of diabetes. The transcriptional coactivator PGC-1α is a powerful regulator of metabolism, but its role in endothelial cells remains poorly understood. We show here that endothelial PGC-1α expression is high in diabetic rodents and humans and that PGC-1α powerfully blocks endothelial migration in cell culture and vasculogenesis in vivo. Mechanistically, PGC-1α induces Notch signaling, blunts activation of Rac/Akt/eNOS signaling, and renders endothelial cells unresponsive to established angiogenic factors. Transgenic overexpression of PGC-1α in the endothelium mimics multiple diabetic phenotypes, including aberrant re-endothelialization after carotid injury, blunted wound healing, and reduced blood flow recovery after hindlimb ischemia. Conversely, deletion of endothelial PGC-1α rescues the blunted wound healing and recovery from hindlimb ischemia seen in type 1 and type 2 diabetes. Endothelial PGC-1α thus potently inhibits endothelial function and angiogenesis, and induction of endothelial PGC-1α contributes to multiple aspects of vascular dysfunction in diabetes.
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10
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Vaisman BL, Andrews KL, Khong SML, Wood KC, Moore XL, Fu Y, Kepka-Lenhart DM, Morris SM, Remaley AT, Chin-Dusting JPF. Selective endothelial overexpression of arginase II induces endothelial dysfunction and hypertension and enhances atherosclerosis in mice. PLoS One 2012; 7:e39487. [PMID: 22829869 PMCID: PMC3400622 DOI: 10.1371/journal.pone.0039487] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2012] [Accepted: 05/21/2012] [Indexed: 01/10/2023] Open
Abstract
Background Cardiovascular disorders associated with endothelial dysfunction, such as atherosclerosis, have decreased nitric oxide (NO) bioavailability. Arginase in the vasculature can compete with eNOS for L-arginine and has been implicated in atherosclerosis. The aim of this study was to evaluate the effect of endothelial-specific elevation of arginase II expression on endothelial function and the development of atherosclerosis. Methodology/Principal Findings Transgenic mice on a C57BL/6 background with endothelial-specific overexpression of human arginase II (hArgII) gene under the control of the Tie2 promoter were produced. The hArgII mice had elevated tissue arginase activity except in liver and in resident peritoneal macrophages, confirming endothelial specificity of the transgene. Using small-vessel myography, aorta from these mice exhibited endothelial dysfunction when compared to their non-transgenic littermate controls. The blood pressure of the hArgII mice was 17% higher than their littermate controls and, when crossed with apoE −/− mice, hArgII mice had increased aortic atherosclerotic lesions. Conclusion We conclude that overexpression of arginase II in the endothelium is detrimental to the cardiovascular system.
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Affiliation(s)
- Boris L. Vaisman
- Cardiovascular-Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Karen L. Andrews
- Vascular Pharmacology Laboratory, Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
- * E-mail:
| | - Sacha M. L. Khong
- Vascular Pharmacology Laboratory, Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Katherine C. Wood
- Cardiovascular-Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Xiao L. Moore
- Vascular Pharmacology Laboratory, Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Yi Fu
- Vascular Pharmacology Laboratory, Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Diane M. Kepka-Lenhart
- Departments of Microbiology and Molecular Genetics, University of Pittsburgh, School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Sidney M. Morris
- Departments of Microbiology and Molecular Genetics, University of Pittsburgh, School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Alan T. Remaley
- Cardiovascular-Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Jaye P. F. Chin-Dusting
- Vascular Pharmacology Laboratory, Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
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Vaisman BL, Demosky SJ, Stonik JA, Ghias M, Knapper CL, Sampson ML, Dai C, Levine SJ, Remaley AT. Endothelial expression of human ABCA1 in mice increases plasma HDL cholesterol and reduces diet-induced atherosclerosis. J Lipid Res 2012; 53:158-67. [PMID: 22039582 PMCID: PMC3243472 DOI: 10.1194/jlr.m018713] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2011] [Revised: 10/26/2011] [Indexed: 01/08/2023] Open
Abstract
The role of endothelial ABCA1 expression in reverse cholesterol transport (RCT) was examined in transgenic mice, using the endothelial-specific Tie2 promoter. Human ABCA1 (hABCA1) was significantly expressed in endothelial cells (EC) of most tissues except the liver. Increased expression of ABCA1 was not observed in resident peritoneal macrophages. ApoA-I-mediated cholesterol efflux from aortic EC was 2.6-fold higher (P < 0.0001) for cells from transgenic versus control mice. On normal chow diet, Tie2 hABCA1 transgenic mice had a 25% (P < 0.0001) increase in HDL-cholesterol (HDL-C) and more than a 2-fold increase of eNOS mRNA in the aorta (P < 0.04). After 6 months on a high-fat, high-cholesterol (HFHC) diet, transgenic mice compared with controls had a 40% increase in plasma HDL-C (P < 0.003) and close to 40% decrease in aortic lesions (P < 0.02). Aortas from HFHC-fed transgenic mice also showed gene expression changes consistent with decreased inflammation and apoptosis. Beneficial effects of the ABCA1 transgene on HDL-C levels or on atherosclerosis were absent when the transgene was transferred onto ApoE or Abca1 knockout mice. In summary, expression of hABCA1 in EC appears to play a role in decreasing diet-induced atherosclerosis in mice and is associated with increased plasma HDL-C levels and beneficial gene expression changes in EC.
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Affiliation(s)
- Boris L Vaisman
- Cardiovascular-Pulmonary Branch, National Heart, Lung, and Blood Institute, Clinical Center, National Institutes of Health, Bethesda, MD, USA.
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Targeting FVIII expression to endothelial cells regenerates a releasable pool of FVIII and restores hemostasis in a mouse model of hemophilia A. Blood 2010; 116:3049-57. [PMID: 20606161 DOI: 10.1182/blood-2010-03-272419] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The natural cell type(s) that synthesize and release factor VIII (FVIII) into the circulation are still not known with certainty. In vitro studies indicate that artificial expression of FVIII in endothelial cells produces an intracellular pool of FVIII that can be mobilized together with its carrier protein, von Willebrand factor (VWF), by agonists. Here, we show that expression of human B-domain deleted FVIII (hFVIII) in the vascular endothelium of otherwise FVIII-deficient mice results in costorage of FVIII and VWF in endothelial Weibel-Palade bodies and restores normal levels and activity of FVIII in plasma. Stored FVIII was mobilized into the circulation by subcutaneous administration of epinephrine. Human FVIII activity in plasma was strictly dependent on the presence of VWF. Endothelial-specific expression of hFVIII rescued the bleeding diathesis of hemophilic mice lacking endogenous FVIII. This hemostatic function of endothelial cell-derived hFVIII was suppressed in the presence of anti-FVIII inhibitory antibodies. These results suggest that targeting FVIII expression to endothelial cells may establish a releasable pool of FVIII and normalize plasma FVIII level and activity in hemophilia A, but does not prevent the inhibitory effect of anti-FVIII antibodies on the hemostatic function of transgene-derived hFVIII as is seen with platelet-derived FVIII expression.
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13
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The power of reversibility regulating gene activities via tetracycline-controlled transcription. Methods Enzymol 2010; 477:429-53. [PMID: 20699154 DOI: 10.1016/s0076-6879(10)77022-1] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Tetracycline-controlled transcriptional activation systems are widely used to control gene expression in transgenic animals in a truly conditional manner. By this we refer to the capability of these expression systems to control gene activities not only in a tissue specific and temporal defined but also reversible manner. This versatility has made the Tet regulatory systems to a preeminent tool in reverse mouse genetics. The development of the technology in the past 15 years will be reviewed and guidelines will be given for its implementation in creating transgenic rodents. Finally, we highlight some recent exciting applications of the Tet technology as well as its foreseeable combination with other emerging technologies in mouse transgenesis.
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Kleinhenz JM, Kleinhenz DJ, You S, Ritzenthaler JD, Hansen JM, Archer DR, Sutliff RL, Hart CM. Disruption of endothelial peroxisome proliferator-activated receptor-gamma reduces vascular nitric oxide production. Am J Physiol Heart Circ Physiol 2009; 297:H1647-54. [PMID: 19666848 DOI: 10.1152/ajpheart.00148.2009] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Vascular endothelial cells express the ligand-activated transcription factor, peroxisome proliferator-activated receptor-gamma (PPARgamma), which participates in the regulation of metabolism, cell proliferation, and inflammation. PPARgamma ligands attenuate, whereas the loss of function mutations in PPARgamma stimulate, endothelial dysfunction, suggesting that PPARgamma may regulate vascular endothelial nitric oxide production. To explore the role of endothelial PPARgamma in the regulation of vascular nitric oxide production in vivo, mice expressing Cre recombinase driven by an endothelial-specific promoter were crossed with mice carrying a floxed PPARgamma gene to produce endothelial PPARgamma null mice (ePPARgamma(-/-)). When compared with littermate controls, ePPARgamma(-/-) animals were hypertensive at baseline and demonstrated comparable increases in systolic blood pressure in response to angiotensin II infusion. When compared with those of control animals, aortic ring relaxation responses to acetylcholine were impaired, whereas relaxation responses to sodium nitroprusside were unaffected in ePPARgamma(-/-) mice. Similarly, intact aortic segments from ePPARgamma(-/-) mice released less nitric oxide than those from controls, whereas endothelial nitric oxide synthase expression was similar in control and ePPARgamma(-/-) aortas. Reduced nitric oxide production in ePPARgamma(-/-) aortas was associated with an increase in the parameters of oxidative stress in the blood and the activation of nuclear factor-kappaB in aortic homogenates. These findings demonstrate that endothelial PPARgamma regulates vascular nitric oxide production and that the disruption of endothelial PPARgamma contributes to endothelial dysfunction in vivo.
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Affiliation(s)
- Jennifer M Kleinhenz
- Department of Medicine, Atlanta Veterans Affairs and Emory University Medical Centers, Atlanta, Georgia, USA
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15
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Hara-Kaonga B, Gao YA, Havrda M, Harrington A, Bergquist I, Liaw L. Variable recombination efficiency in responder transgenes activated by Cre recombinase in the vasculature. Transgenic Res 2009; 15:101-6. [PMID: 16475014 DOI: 10.1007/s11248-005-2541-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2005] [Accepted: 08/26/2005] [Indexed: 10/25/2022]
Abstract
Cre recombinase has become a ubiquitous tool in transgenic strategies for regulation of transgene expression in a tissue-specific manner. We report analysis of two SM22alphaCre lines and their ability to mediate genomic recombination in five independent Cre-responsive transgenic lines. One of the SM22alphaCre lines developed was a tet-on system based on the reverse tetracycline transactivator. Our goal was to use this strategy to inhibit the Notch signaling pathway specifically in smooth muscle cells. Our responder transgenes contained a constitutively expressed marker gene (chloramphenicol acetyltransferase, CAT), flanked by loxP sites in direct orientation, upstream of Notch-related transgenes. We developed two dominant negative Notch transgenic responder lines activated by Cre-mediated DNA recombination. The first is the extracellular domain of human Jagged1, and the second is the extracellular domain of the human Notch2 receptor. Despite high expression of the marker gene in all responder lines, we found that Cre-mediated genomic recombination between these five lines was highly variable, ranging from 46 to 93% of individuals using an SM22alphaCre activating strain, or 8-58% of individuals using an inducible SM22alphartTACre. In all cases examined, detection of recombination by PCR correlated with expression of the transgene as determined by Western blot analysis. Our studies reflect the variability in recombination success based on the responder strain, presumably due to inaccessibility of the locus of integration of the responder allele.
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Affiliation(s)
- Bochiwe Hara-Kaonga
- Center for Molecular Medicine, Maine Medical Center Research Institute, 81 Research Drive, Scarborough, ME 04074, USA
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16
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Shear stress-induced transcriptional regulation via hybrid promoters as a potential tool for promoting angiogenesis. Angiogenesis 2009; 12:231-42. [PMID: 19322670 DOI: 10.1007/s10456-009-9143-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2009] [Accepted: 03/13/2009] [Indexed: 10/21/2022]
Abstract
Among the key effects of fluid shear stress on vascular endothelial cells is modulation of gene expression. Promoter sequences termed shear stress response elements (SSREs) mediate the responsiveness of endothelial genes to shear stress. While previous studies showed that shear stress responsiveness is mediated by a single SSRE, these endogenous promoters often encode for multiple SSREs. Moreover, hybrid promoters encoding a single SSRE rarely respond to shear stress at the same magnitude as the endogenous promoter. Thus, to better understand the interplay between the various SSREs, and between SSREs and endothelial-specific sequences (ESS), we generated a series of constructs regulated by SSREs cassettes alone, or in combination with ESS, and tested their response to shear stress and endothelial specific expression. Among these constructs, the most responsive promoter (NR1/2) encoded a combination of two GAGACC/SSREs, the Sp1/Egr1 sequence, as well as a TPA response element (TRE). This construct was four- to five-fold more responsive to shear stress than a promoter encoding a single SSRE. The expression of constructs containing other SSRE combinations was unaffected or suppressed by shear stress. Addition of ESS derived from the Tie2 promoter, either 5' or 3' to NR1/2 resulted in shear stress transcriptional suppression, yet retained endothelial specific expression. Thus, the combination and localization order of the various SSREs in a single promoter is crucial in determining the pattern and degree of shear stress responsiveness. These shear stress responsive cassettes may prove beneficial in our attempt to time the expression of an endothelial transgene in the vasculature.
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17
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Ye X, Ding J, Zhou X, Chen G, Liu SF. Divergent roles of endothelial NF-kappaB in multiple organ injury and bacterial clearance in mouse models of sepsis. ACTA ACUST UNITED AC 2008; 205:1303-15. [PMID: 18474628 PMCID: PMC2413029 DOI: 10.1084/jem.20071393] [Citation(s) in RCA: 158] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
To define the roles of endothelial-intrinsic nuclear factor κB (NF-κB) activity in host defense and multiple organ injury in response to sepsis, we generated double transgenic (TG) mice (EC-rtTA/I-κBαmt) that conditionally overexpress a degradation-resistant form of the NF-κB inhibitor I-κBα (I-κBαmt) selectively on vascular endothelium. The EC-rtTA/I-κBαmt mice had no basal, but a relatively high level of doxycycline-inducible, I-κBαmt expression. I-κBαmt expression was detected in endothelial cells, but not in fibroblasts, macrophages, and whole blood cells, confirming that transgene expression was restricted to the endothelium. When subjected to endotoxemia, EC-rtTA/I-κBαmt mice showed endothelial-selective blockade of NF-κB activation, repressed expression of multiple endothelial adhesion molecules, reduced neutrophil infiltration into multiple organs, decreased endothelial permeability, ameliorated multiple organ injury, reduced systemic hypotension, and abrogated intravascular coagulation. When subjected to cecal ligation and puncture–induced sepsis, the TG mice had less severe multiple organ injury and improved survival compared with wild-type (WT) mice. WT and EC-rtTA/I-κBαmt mice had comparable capacity to clear three different pathogenic bacteria. Our data demonstrate that endothelial NF-κB activity is an essential mediator of septic multiple organ inflammation and injury but plays little role in the host defense response to eradicate invading pathogenic bacteria.
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Affiliation(s)
- Xiaobing Ye
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, The Feinstein Institute for Medical Research and Long Island Jewish Medical Center, The Long Island Campus for the Albert Einstein College of Medicine, New Hyde Park, NY 11040, USA
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18
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Inducible endothelial cell-specific gene expression in transgenic mouse embryos and adult mice. Exp Cell Res 2008; 314:1202-16. [DOI: 10.1016/j.yexcr.2007.12.026] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2007] [Revised: 12/23/2007] [Accepted: 12/24/2007] [Indexed: 02/01/2023]
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19
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Vervoort VS, Lu M, Valencia F, Lesperance J, Breier G, Oshima R, Pasquale EB. A novel Flk1-TVA transgenic mouse model for gene delivery to angiogenic vasculature. Transgenic Res 2007; 17:403-15. [DOI: 10.1007/s11248-007-9156-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2007] [Accepted: 10/26/2007] [Indexed: 10/22/2022]
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20
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Ching S, Zhang H, Belevych N, He L, Lai W, Pu XA, Jaeger LB, Chen Q, Quan N. Endothelial-specific knockdown of interleukin-1 (IL-1) type 1 receptor differentially alters CNS responses to IL-1 depending on its route of administration. J Neurosci 2007; 27:10476-86. [PMID: 17898219 PMCID: PMC6673171 DOI: 10.1523/jneurosci.3357-07.2007] [Citation(s) in RCA: 125] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2006] [Revised: 08/08/2007] [Accepted: 08/09/2007] [Indexed: 12/22/2022] Open
Abstract
Interleukin-1 (IL-1) has been implicated as a critical mediator of neuroimmune communication. In the brain, the functional receptor for IL-1, type 1 IL-1 receptor (IL-1R1), is localized primarily to the endothelial cells. In this study, we created an endothelial-specific IL-1R1 knockdown model to test the role of endothelial IL-1R1 in mediating the effects of IL-1. Neuronal activation in the hypothalamus was measured by c-fos expression in the paraventricular nucleus and the ventromedial preoptic area. In addition, two specific sickness symptoms, febrile response and reduction of locomotor activity, were studied. Intracerebroventricular injection of IL-1 induced leukocyte infiltration into the CNS, activation of hypothalamic neurons, fever, and reduced locomotor activity in normal mice. Endothelial-specific knockdown of IL-1R1 abrogated all these responses. Intraperitoneal injection of IL-1 also induced neuronal activation in the hypothalamus, fever, and reduced locomotor activity, without inducing leukocyte infiltration into the brain. Endothelial-specific knockdown of IL-1R1 suppressed intraperitoneal IL-1-induced fever, but not the induction of c-fos in hypothalamus. When IL-1 was given intravenously, endothelial knockdown of IL-1R1 abolished intravenous IL-1-induced CNS activation and the two monitored sickness symptoms. In addition, endothelial-specific knockdown of IL-1R1 blocked the induction of cyclooxygenase-2 expression induced by all three routes of IL-1 administration. These results show that the effects of intravenous and intracerebroventricular IL-1 are mediated by endothelial IL-1R1, whereas the effects of intraperitoneal IL-1 are partially dependent on endothelial IL-1R1.
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Affiliation(s)
| | | | | | | | | | - Xin-an Pu
- Center for Neurobiology, Ohio State University, Columbus, Ohio 43210-1094, and
| | - Laura B. Jaeger
- Department of Pharmacology and Physiology, St. Louis University, St. Louis, Missouri 63106
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21
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Nguyen Din Cat A, Sainte-Marie Y, Jaisser F. Animal models in cardiovascular diseases: new insights from conditional models. Handb Exp Pharmacol 2007:377-405. [PMID: 17203664 DOI: 10.1007/978-3-540-35109-2_16] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Conditional systems have proven to be efficient and powerful to delineate several aspects of cardiac pathophysiology and diseases. The possibility of addressing a particular time point in animal life is certainly an important breakthrough allowed by conditional strategies with temporal control of either transgene expression or gene modifications. The purpose of this review is to present various mouse models for cardiovascular diseases based on conditional approaches.
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Affiliation(s)
- A Nguyen Din Cat
- INSERM U772, College De France, 11 Place Marcelin Berthelot, 75231 Parisx 05, France
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22
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Fathers KE, Stone CM, Minhas K, Marriott JJA, Greenwood JD, Dumont DJ, Coomber BL. Heterogeneity of Tie2 expression in tumor microcirculation: influence of cancer type, implantation site, and response to therapy. THE AMERICAN JOURNAL OF PATHOLOGY 2006; 167:1753-62. [PMID: 16314485 PMCID: PMC1613180 DOI: 10.1016/s0002-9440(10)61256-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
To evaluate the expression of the Tie2/Tek tyrosine kinase receptor in tumor blood vessels, we examined Tie2lacZ(+)/RAG1(-) mice. There was considerable heterogeneity (Tie2-negative, Tie2-positive, or Tie2-composite blood vessels) in subcutaneous xenografts of human colorectal carcinoma (HCT116; 97.5% Tie2-positive vessels) versus human melanoma (WM115; 75.9% Tie2-positive vessels). Similar patterns of Tie2 expression occurred in abdominal metastases derived from the same cell lines. Immunostaining for endothelial markers and Tie2 revealed that endogenous protein levels corresponded with transgene activity. Endothelial cells were confirmed to be of mouse origin through triple immunofluorescence staining with mouse antiserum to human nuclei, isolectin GS-IB(4), and anti-Tie2. Similar Tie2 heterogeneity was observed in clinical specimens from a variety of human cancers, including malignant melanoma and colorectal carcinoma. We also examined the effect of Tek-Delta Fc anti-angiogenic therapy on tumor growth and Tie2 expression patterns in HCT116 and WM115 subcutaneous xenografts. Tek-Delta induced extensive tumor regression in HCT116 tumors and concomitant reductions in Tie2-expressing blood vessels. However, no significant responses were seen in Tek-Delta-treated WM115 tumors. Thus, vascular heterogeneity of Tie2 expression is cancer-type specific, suggesting that the tumor microenvironment and/or direct cancer cell interactions influence Tie2 endothelial expression.
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Affiliation(s)
- Kelly E Fathers
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Canada
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23
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Abstract
The integrity of the endothelial lining of the vasculature is essential for vascular homeostasis and normal organ function. Endothelial injury or dysfunction has been implicated in the pathogenesis of diverse vascular diseases. Studies in vitro have demonstrated that a wide variety of stimuli can induce programmed cell death (apoptosis) of endothelial cells, and have suggested that apoptosis could be an important mechanism of vascular injury, resulting in vascular leak, inflammation, and coagulation. In this review, we focus on the potential role of endothelial apoptosis in the initiation and progression of inflammatory and immune disorders, reviewing human diseases and in vivo models in which endothelial cell apoptosis has been demonstrated. Although endothelial cell apoptosis is observed in many inflammatory and immune disorders, we find that there is, as yet, only limited experimental evidence demonstrating that it is critical to the pathogenesis of disease.
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Affiliation(s)
- R K Winn
- Department of Surgery, University of Washington, Seattle, WA, USA.
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