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Segmental outflow dynamics in the trabecular meshwork of living mice. Exp Eye Res 2022; 225:109285. [PMID: 36273576 DOI: 10.1016/j.exer.2022.109285] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 10/10/2022] [Accepted: 10/14/2022] [Indexed: 12/29/2022]
Abstract
Aqueous humour does not drain uniformly through the trabecular meshwork (TM), but rather follows non-uniform or "segmental" routes. In this study, we examined whether segmental outflow patterns in the TM change over time in living mice and whether such changes are affected by age. Segmental outflow patterns were labelled by constant-pressure infusion of fluorescent tracer microparticles into the anterior chamber of anesthetised C57BL/6J mice at 3 or 8 months of age. Two different tracer colours were infused at separate time points with an interval of Δt = 0, 2, 7 or 14 days. In a separate experiment, one tracer was infused in vivo while the second tracer was infused ex vivo after 2 days. The spatial relationship between the two tracer patterns was analysed using the Pearson's correlation coefficient, r. In 3-month-old mice, there was a time-dependent decay in r, which was near unity at Δt = 0 and near zero at Δt = 14 days. In 8-month-old mice, r remained elevated for 14 days. Segmental outflow patterns measured in young mice ex vivo were not significantly different from those measured in vivo after accounting for the expected changes over 2 days. Therefore, segmental outflow patterns are not static in the TM but redistribute over time, achieving near complete loss of correlation by 2 weeks in young healthy mice. There is an age-related decline in the rate at which segmental outflow patterns redistribute in the TM. Further research is needed to understand the dynamic factors controlling segmental outflow.
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Abstract
Since the initial reports implicating caveolin-1 (CAV1) in neoplasia, the scientific community has made tremendous strides towards understanding how CAV1-dependent signaling and caveolae assembly modulate solid tumor growth. Once a solid neoplastic tumor reaches a certain size, it will increasingly rely on its stroma to meet the metabolic demands of the rapidly proliferating cancer cells, a limitation typically but not exclusively addressed via the formation of new blood vessels. Landmark studies using xenograft tumor models have highlighted the importance of stromal CAV1 during neoplastic blood vessel growth from preexisting vasculature, a process called angiogenesis, and helped identify endothelium-specific signaling events regulated by CAV1, such as vascular endothelial growth factor (VEGF) receptors as well as the endothelial nitric oxide (NO) synthase (eNOS) systems. This chapter provides a glimpse into the signaling events modulated by CAV1 and its scaffolding domain (CSD) during endothelial-specific aspects of neoplastic growth, such as vascular permeability, angiogenesis, and mechanotransduction.
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Affiliation(s)
- Pascal Bernatchez
- Department of Anesthesiology, Pharmacology & Therapeutics, Faculty of Medicine, University of British Columbia (UBC), 2176 Health Sciences mall, room 217, Vancouver, BC, V6T 1Z3, Canada. .,Centre for Heart & Lung Innovation, St. Paul's Hospital, Vancouver, Canada.
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Role of the Platelets and Nitric Oxide Biotransformation in Ischemic Stroke: A Translative Review from Bench to Bedside. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2020; 2020:2979260. [PMID: 32908630 PMCID: PMC7474795 DOI: 10.1155/2020/2979260] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 07/27/2020] [Indexed: 12/13/2022]
Abstract
Ischemic stroke remains the fifth cause of death, as reported worldwide annually. Endothelial dysfunction (ED) manifesting with lower nitric oxide (NO) bioavailability leads to increased vascular tone, inflammation, and platelet activation and remains among the major contributors to cardiovascular diseases (CVD). Moreover, temporal fluctuations in the NO bioavailability during ischemic stroke point to its key role in the cerebral blood flow (CBF) regulation, and some data suggest that they may be responsible for the maintenance of CBF within the ischemic penumbra in order to reduce infarct size. Several years ago, the inhibitory role of the platelet NO production on a thrombus formation has been discovered, which initiated the era of extensive studies on the platelet-derived nitric oxide (PDNO) as a platelet negative feedback regulator. Very recently, Radziwon-Balicka et al. discovered two subpopulations of human platelets, based on the expression of the endothelial nitric oxide synthase (eNOS-positive or eNOS-negative platelets, respectively). The e-NOS-negative ones fail to produce NO, which attenuates their cyclic guanosine monophosphate (cGMP) signaling pathway and-as result-promotes adhesion and aggregation while the e-NOS-positive ones limit thrombus formation. Asymmetric dimethylarginine (ADMA), a competitive NOS inhibitor, is an independent cardiovascular risk factor, and its expression alongside with the enzymes responsible for its synthesis and degradation was recently shown also in platelets. Overproduction of ADMA in this compartment may increase platelet activation and cause endothelial damage, additionally to that induced by its plasma pool. All the recent discoveries of diverse eNOS expression in platelets and its role in regulation of thrombus formation together with studies on the NOS inhibitors have opened a new chapter in translational medicine investigating the onset of acute cardiovascular events of ischemic origin. This translative review briefly summarizes the role of platelets and NO biotransformation in the pathogenesis and clinical course of ischemic stroke.
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Leloup AJA, Van Hove CE, De Moudt S, De Keulenaer GW, Fransen P. Ex vivo aortic stiffness in mice with different eNOS activity. Am J Physiol Heart Circ Physiol 2020; 318:H1233-H1244. [DOI: 10.1152/ajpheart.00737.2019] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Endothelial function and NO bioavailability are important determinants of aortic biomechanics and function. With a new technique we investigated the ex vivo aortic segment biomechanics of different mouse models with altered NO signaling. Our experiments clearly show that chronic distortion of NO signaling triggered several compensatory mechanisms that reflect the organism’s attempt to maintain optimal central hemodynamics.
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Affiliation(s)
- Arthur J. A. Leloup
- Department of Pharmaceutical Sciences, University of Antwerp, Antwerp, Belgium
| | - Cor E. Van Hove
- Faculty of Medicine and Health Sciences, Laboratory of Pharmacology, University of Antwerp, Antwerp, Belgium
| | - Sofie De Moudt
- Department of Pharmaceutical Sciences, University of Antwerp, Antwerp, Belgium
| | - Gilles W. De Keulenaer
- Department of Pharmaceutical Sciences, University of Antwerp, Antwerp, Belgium
- Department of Cardiology, Middelheim Hospital, Antwerp, Belgium
| | - Paul Fransen
- Department of Pharmaceutical Sciences, University of Antwerp, Antwerp, Belgium
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Sellers SL, Milad N, Chan R, Mielnik M, Jermilova U, Huang PL, de Crom R, Hirota JA, Hogg JC, Sandor GG, Van Breemen C, Esfandiarei M, Seidman MA, Bernatchez P. Inhibition of Marfan Syndrome Aortic Root Dilation by Losartan: Role of Angiotensin II Receptor Type 1-Independent Activation of Endothelial Function. THE AMERICAN JOURNAL OF PATHOLOGY 2019; 188:574-585. [PMID: 29433732 DOI: 10.1016/j.ajpath.2017.11.006] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Revised: 10/18/2017] [Accepted: 11/16/2017] [Indexed: 01/13/2023]
Abstract
Marfan syndrome (MFS) is a genetic disorder that frequently leads to aortic root dissection and aneurysm. Despite promising preclinical and pilot clinical data, a recent large-scale study using antihypertensive angiotensin II (AngII) receptor type 1 (ATR1) blocker losartan has failed to meet expectations at preventing MFS-associated aortic root dilation, casting doubts about optimal therapy. To study the deleterious role of normal ATR1 signaling in aortic root widening, we generated MFS mice lacking ATR1a expression in an attempt to preserve protective ATR2 signaling. Despite being hypotensive and resistant to AngII vasopressor effects, MFS/ATR1a-null mice showed unabated aortic root enlargement and remained fully responsive to losartan, confirming that blood pressure lowering is of minor therapeutic value in MFS and that losartan's antiremodeling properties may be ATR1 independent. Having shown that MFS causes endothelial dysfunction and that losartan can activate endothelial function in mice and patients, we found that nitric oxide synthase (NOS) inhibition renders losartan therapeutically inactive, whereas multiple transgenic and pharmacologic models of endothelial NOS activation block aortic root dilation by correcting extracellular signal-regulated kinase signaling. In vitro, losartan can increase endothelial NO release in the absence of AngII and correct MFS NO levels in vivo. Our data suggest that increased protective endothelial function, rather than ATR1 inhibition or blood pressure lowering, might be of therapeutic significance in preventing aortic root disease in MFS.
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Affiliation(s)
- Stephanie L Sellers
- Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia (UBC), Vancouver, British Columbia, Canada; UBC Centre for Heart Lung Innovation and St. Paul's Hospital, University of British Columbia (UBC), Vancouver, British Columbia, Canada
| | - Nadia Milad
- Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia (UBC), Vancouver, British Columbia, Canada; UBC Centre for Heart Lung Innovation and St. Paul's Hospital, University of British Columbia (UBC), Vancouver, British Columbia, Canada
| | - Rayleigh Chan
- Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia (UBC), Vancouver, British Columbia, Canada; UBC Centre for Heart Lung Innovation and St. Paul's Hospital, University of British Columbia (UBC), Vancouver, British Columbia, Canada
| | - Michael Mielnik
- Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia (UBC), Vancouver, British Columbia, Canada; UBC Centre for Heart Lung Innovation and St. Paul's Hospital, University of British Columbia (UBC), Vancouver, British Columbia, Canada
| | - Una Jermilova
- Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia (UBC), Vancouver, British Columbia, Canada; UBC Centre for Heart Lung Innovation and St. Paul's Hospital, University of British Columbia (UBC), Vancouver, British Columbia, Canada
| | - Paul L Huang
- Cardiovascular Research Centre, Massachusetts General Hospital, Harvard University, Charlestown, Massachusetts
| | - Rini de Crom
- Department of Cell Biology and Genetics, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Jeremy A Hirota
- UBC Centre for Heart Lung Innovation and St. Paul's Hospital, University of British Columbia (UBC), Vancouver, British Columbia, Canada; Division of Respiratory Medicine, Department of Medicine, Chan-Yeung Centre for Occupational and Environmental Respiratory Disease, University of British Columbia (UBC), Vancouver, British Columbia, Canada
| | - James C Hogg
- UBC Centre for Heart Lung Innovation and St. Paul's Hospital, University of British Columbia (UBC), Vancouver, British Columbia, Canada; Department of Pathology and Laboratory Medicine, University of British Columbia (UBC), Vancouver, British Columbia, Canada
| | - George G Sandor
- Providence Health Care, and the Child and Family Research Institute, University of British Columbia (UBC), Vancouver, British Columbia, Canada
| | - Casey Van Breemen
- Providence Health Care, and the Child and Family Research Institute, University of British Columbia (UBC), Vancouver, British Columbia, Canada
| | - Mitra Esfandiarei
- Department of Biomedical Sciences, Midwestern University, Glendale, Arizona
| | - Michael A Seidman
- UBC Centre for Heart Lung Innovation and St. Paul's Hospital, University of British Columbia (UBC), Vancouver, British Columbia, Canada; Department of Pathology and Laboratory Medicine, University of British Columbia (UBC), Vancouver, British Columbia, Canada
| | - Pascal Bernatchez
- Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia (UBC), Vancouver, British Columbia, Canada; UBC Centre for Heart Lung Innovation and St. Paul's Hospital, University of British Columbia (UBC), Vancouver, British Columbia, Canada.
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Natarajan M, Habib SL, Reddick RL, Delma CR, Manickam K, Prihoda TJ, Werner SL, Mohan S. Endothelial cell-specific overexpression of endothelial nitric oxide synthase in Ins2Akita mice exacerbates diabetic nephropathy. J Diabetes Complications 2019; 33:23-32. [PMID: 30424931 PMCID: PMC6344355 DOI: 10.1016/j.jdiacomp.2018.10.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 08/13/2018] [Accepted: 10/07/2018] [Indexed: 10/28/2022]
Abstract
Previous studies demonstrated that global deficiency of eNOS in diabetic mice exacerbated renal lesions and that overexpression of eNOS may protect against tissue injury. Our study revealed for the first time overexpression of eNOS leads to disease progression rather than protection. Transgenic mice selectively expressing eNOS in endothelial cells (eNOSTg) were cross bred with Ins2Akita type-1 (AK) diabetic mice to generate eNOS overexpressing eNOSTg/AK mice. Wild type, eNOSTg, AK and eNOSTg/AK mice were assessed for kidney function and blood glucose levels. Remarkably, overexpressing eNOSTg mice showed evidence of unpredicted glomerular injury with segmental mesangiolysis and occasional microaneurysms. Notably, in eNOSTg/AK mice overexpression of eNOS led to increased glomerular/endothelial injury that was associated with increased superoxide levels and renal dysfunction. Results indicate for the first time that overexpressing eNOS in endothelial cells cannot ameliorate diabetic lesions, but paradoxically leads to progression of nephropathy likely due to eNOS uncoupling and superoxide upsurge. This novel finding has a significant impact on current therapeutic strategies to improve endothelial function and prevent progression of diabetic renal disease. Further, the eNOSTg/AK model developed in this study has significant translational potentials for elucidating the underlying mechanism implicated in the deflected function of eNOS in diabetic nephropathy.
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Affiliation(s)
- Mohan Natarajan
- Department of Pathology and Laboratory Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Samy L Habib
- Geriatric Research Education and Clinical Center, South Texas Veterans Healthcare System and Cell Systems & Anatomy, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Robert L Reddick
- Department of Pathology and Laboratory Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Caroline R Delma
- Department of Pathology and Laboratory Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Krishnan Manickam
- Department of Pathology and Laboratory Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Thomas J Prihoda
- Department of Pathology and Laboratory Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Sherry L Werner
- Department of Pathology and Laboratory Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Sumathy Mohan
- Department of Pathology and Laboratory Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.
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7
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Eroglu E, Charoensin S, Bischof H, Ramadani J, Gottschalk B, Depaoli MR, Waldeck-Weiermair M, Graier WF, Malli R. Genetic biosensors for imaging nitric oxide in single cells. Free Radic Biol Med 2018; 128:50-58. [PMID: 29398285 PMCID: PMC6173299 DOI: 10.1016/j.freeradbiomed.2018.01.027] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Revised: 01/19/2018] [Accepted: 01/22/2018] [Indexed: 01/16/2023]
Abstract
UNLABELLED Over the last decades a broad collection of sophisticated fluorescent protein-based probes was engineered with the aim to specifically monitor nitric oxide (NO), one of the most important signaling molecules in biology. Here we report and discuss the characteristics and fields of applications of currently available genetically encoded fluorescent sensors for the detection of NO and its metabolites in different cell types. LONG ABSTRACT Because of its radical nature and short half-life, real-time imaging of NO on the level of single cells is challenging. Herein we review state-of-the-art genetically encoded fluorescent sensors for NO and its byproducts such as peroxynitrite, nitrite and nitrate. Such probes enable the real-time visualization of NO signals directly or indirectly on the level of single cells and cellular organelles and, hence, extend our understanding of the spatiotemporal dynamics of NO formation, diffusion and degradation. Here, we discuss the significance of NO detection in individual cells and on subcellular level with genetic biosensors. Currently available genetically encoded fluorescent probes for NO and nitrogen species are critically discussed in order to provide insights in the functionality and applicability of these promising tools. As an outlook we provide ideas for novel approaches for the design and application of improved NO probes and fluorescence imaging protocols.
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Affiliation(s)
- Emrah Eroglu
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Suphachai Charoensin
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Helmut Bischof
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Jeta Ramadani
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Benjamin Gottschalk
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Maria R Depaoli
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Markus Waldeck-Weiermair
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Wolfgang F Graier
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria; BioTechMed Graz, Mozartgasse 12/II, 8010 Graz, Austria
| | - Roland Malli
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria; BioTechMed Graz, Mozartgasse 12/II, 8010 Graz, Austria.
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8
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Radziwon-Balicka A, Lesyk G, Back V, Fong T, Loredo-Calderon EL, Dong B, El-Sikhry H, El-Sherbeni AA, El-Kadi A, Ogg S, Siraki A, Seubert JM, Santos-Martinez MJ, Radomski MW, Velazquez-Martinez CA, Winship IR, Jurasz P. Differential eNOS-signalling by platelet subpopulations regulates adhesion and aggregation. Cardiovasc Res 2018; 113:1719-1731. [PMID: 29016749 DOI: 10.1093/cvr/cvx179] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Accepted: 09/01/2017] [Indexed: 12/22/2022] Open
Abstract
Aims In addition to maintaining haemostasis, circulating blood platelets are the cellular culprits that form occlusive thrombi in arteries and veins. Compared to blood leucocytes, which exist as functionally distinct subtypes, platelets are considered to be relatively simple cell fragments that form vascular system plugs without a differentially regulated cellular response. Hence, investigation into platelet subpopulations with distinct functional roles in haemostasis/thrombosis has been limited. In our present study, we investigated whether functionally distinct platelet subpopulations exist based on their ability to generate and respond to nitric oxide (NO), an endogenous platelet inhibitor. Methods and results Utilizing highly sensitive and selective flow cytometry protocols, we demonstrate that human platelet subpopulations exist based on the presence and absence of endothelial nitric oxide synthase (eNOS). Platelets lacking eNOS (approximately 20% of total platelets) fail to produce NO and have a down-regulated soluble guanylate cyclase-protein kinase G (sGC-PKG)-signalling pathway. In flow chamber and aggregation experiments eNOS-negative platelets primarily initiate adhesion to collagen, more readily activate integrin αIIbβ3 and secrete matrix metalloproteinase-2, and form larger aggregates than their eNOS-positive counterparts. Conversely, platelets having an intact eNOS-sGC-PKG-signalling pathway (approximately 80% of total platelets) form the bulk of an aggregate via increased thromboxane synthesis and ultimately limit its size via NO generation. Conclusion These findings reveal previously unrecognized characteristics and complexity of platelets and their regulation of adhesion/aggregation. The identification of platelet subpopulations also has potentially important consequences to human health and disease as impaired platelet NO-signalling has been identified in patients with coronary artery disease.
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Affiliation(s)
- Aneta Radziwon-Balicka
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB T6G-2E1, Canada
| | - Gabriela Lesyk
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB T6G-2E1, Canada
| | - Valentina Back
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB T6G-2E1, Canada
| | - Teresa Fong
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB T6G-2E1, Canada
| | - Erica L Loredo-Calderon
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB T6G-2E1, Canada
| | - Bin Dong
- Neurochemical Research Unit, Department of Psychiatry, University of Alberta, Edmonton, AB T6G-2R3, Canada
| | - Haitham El-Sikhry
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB T6G-2E1, Canada
| | - Ahmed A El-Sherbeni
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB T6G-2E1, Canada
| | - Ayman El-Kadi
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB T6G-2E1, Canada
| | - Stephen Ogg
- Department of Medical Microbiology and Immunology, University of Alberta Edmonton, AB T6G-2E1, Canada
| | - Arno Siraki
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB T6G-2E1, Canada
| | - John M Seubert
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB T6G-2E1, Canada.,Department of Pharmacology, University of Alberta Edmonton, AB T6G-2H7, Canada.,Cardiovascular Research Centre, University of Alberta, Edmonton, AB T6G-2S2, Canada.,Mazankowski Heart Institute, Edmonton, AB T6G-2R7
| | | | - Marek W Radomski
- College of Medicine, University of Saskatchewan, Saskatoon, SK S7N-5E5, Canada
| | | | - Ian R Winship
- Neurochemical Research Unit, Department of Psychiatry, University of Alberta, Edmonton, AB T6G-2R3, Canada
| | - Paul Jurasz
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB T6G-2E1, Canada.,Department of Pharmacology, University of Alberta Edmonton, AB T6G-2H7, Canada.,Cardiovascular Research Centre, University of Alberta, Edmonton, AB T6G-2S2, Canada.,Mazankowski Heart Institute, Edmonton, AB T6G-2R7
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9
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Seynhaeve ALB, Oostinga D, van Haperen R, Eilken HM, Adams S, Adams RH, Ten Hagen TLM. Spatiotemporal endothelial cell - pericyte association in tumors as shown by high resolution 4D intravital imaging. Sci Rep 2018; 8:9596. [PMID: 29941944 PMCID: PMC6018425 DOI: 10.1038/s41598-018-27943-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 06/12/2018] [Indexed: 12/21/2022] Open
Abstract
Endothelial cells and pericytes are integral cellular components of the vasculature with distinct interactive functionalities. To study dynamic interactions between these two cells we created two transgenic animal lines. A truncated eNOS (endothelial nitric oxide synthase) construct was used as a GFP tag for endothelial cell evaluation and an inducible Cre-lox recombination, under control of the Pdgfrb (platelet derived growth factor receptor beta) promoter, was created for pericyte assessment. Also, eNOStag-GFP animals were crossed with the already established Cspg4-DsRed mice expressing DsRed fluorescent protein in pericytes. For intravital imaging we used tumors implanted in the dorsal skinfold of these transgenic animals. This setup allowed us to study time and space dependent complexities, such as distribution, morphology, motility, and association between both vascular cell types in all angiogenetic stages, without the need for additional labeling. Moreover, as fluorescence was still clearly detectable after fixation, it is possible to perform comparative histology following intravital evaluation. These transgenic mouse lines form an excellent model to capture collective and individual cellular and subcellular endothelial cell – pericyte dynamics and will help answer key questions on the cellular and molecular relationship between these two cells.
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Affiliation(s)
- Ann L B Seynhaeve
- Laboratory Experimental Surgical Oncology, Department of Surgery, Erasmus MC, 3015CE, Rotterdam, The Netherlands.
| | - Douwe Oostinga
- Laboratory Experimental Surgical Oncology, Department of Surgery, Erasmus MC, 3015CE, Rotterdam, The Netherlands
| | - Rien van Haperen
- Department of Cell Biology, Erasmus MC, 3015CE, Rotterdam, The Netherlands
| | - Hanna M Eilken
- Department of Tissue Morphogenesis, Max-Planck-Institute for Molecular Biomedicine, and Faculty of Medicine, University of Münster, D-48149, Münster, Germany
| | - Susanne Adams
- Department of Tissue Morphogenesis, Max-Planck-Institute for Molecular Biomedicine, and Faculty of Medicine, University of Münster, D-48149, Münster, Germany
| | - Ralf H Adams
- Department of Tissue Morphogenesis, Max-Planck-Institute for Molecular Biomedicine, and Faculty of Medicine, University of Münster, D-48149, Münster, Germany
| | - Timo L M Ten Hagen
- Laboratory Experimental Surgical Oncology, Department of Surgery, Erasmus MC, 3015CE, Rotterdam, The Netherlands
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10
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Seynhaeve ALB, Ten Hagen TLM. Intravital Microscopy of Tumor-associated Vasculature Using Advanced Dorsal Skinfold Window Chambers on Transgenic Fluorescent Mice. J Vis Exp 2018. [PMID: 29443052 PMCID: PMC5908657 DOI: 10.3791/55115] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Tumor and tumor vessel development, as well as tumor response to therapeutics, are highly dynamic biological processes. Histology provides static information and is often not sufficient for a correct interpretation. Intravital evaluation, in which a process is followed in time, provides extra and often unexpected information. With the creation of transgenic animals expressing cell-specific markers and live cell tracers, improvements to imaging equipment, and the development of several imaging chambers, intravital microscopy has become an important tool to better understand biological processes. This paper describes an experimental design for the investigation of tumor vessel development and of therapeutic effects in a spatial and temporal manner. Using this setup, the stage of vessel development, tip cell and lumen formation, blood flow, extravasation, an established vascular bed, and vascular destruction can be visualized and followed. Furthermore, therapeutic effects, intratumoral fate, and the localization of chemotherapeutic compounds can also be followed.
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Affiliation(s)
- Ann L B Seynhaeve
- Laboratory Experimental Surgical Oncology, Section Surgical Oncology, Department of Surgery, Erasmus MC
| | - Timo L M Ten Hagen
- Laboratory Experimental Surgical Oncology, Section Surgical Oncology, Department of Surgery, Erasmus MC;
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11
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Rzechorzek W, Zhang H, Buckley BK, Hua K, Pomp D, Faber JE. Aerobic exercise prevents rarefaction of pial collaterals and increased stroke severity that occur with aging. J Cereb Blood Flow Metab 2017; 37:3544-3555. [PMID: 28685617 PMCID: PMC5669350 DOI: 10.1177/0271678x17718966] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Revised: 06/07/2017] [Accepted: 06/10/2017] [Indexed: 11/16/2022]
Abstract
Variation in extent of the brain's collateral circulation is an important determinant of variation in the severity of stroke and efficacy of revascularization therapies. However, the number and diameter of pial collateral "arterioles" decrease with aging in associated with reduced eNOS and increased oxidative stress. We tested whether exercise reduces this aging-induced rarefaction. Twelve-month-old mice were randomized to sedentary or voluntary wheel-running. At 26 months' age, permanent MCA occlusion was followed 72 h later by determination of infarct volume and vascular casting after maximal dilation. The decline in collateral number and diameter and 2.4-fold increase in infarct volume evident in 26-versus 3-month-old sedentary mice were prevented by exercise-training. In contrast, number and diameter of the posterior communicating collateral "arteries" were unaffected by aging or exercise. Interestingly, diameter of the primary intracranial arteries increased with aging. Mechanistically, genetic overexpression of eNOS inhibited age-induced collateral rarefaction, and exercise increased eNOS and SOD2 and decreased the inflammatory marker NFkB assessed in hindlimb arteries. In conclusion, exercise prevented age-induced rarefaction of pial collaterals and reduced infarct volume. Aging also promoted outward remodeling of intracranial arteries. These effects were associated with increased eNOS and reduced markers of inflammation and aging in the vascular wall.
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Affiliation(s)
- Wojciech Rzechorzek
- Departments of Cell Biology and Physiology, University of North Carolina at Chapel Hill, NC, USA
| | - Hua Zhang
- Departments of Cell Biology and Physiology, University of North Carolina at Chapel Hill, NC, USA
| | - Brian K Buckley
- Departments of Cell Biology and Physiology, University of North Carolina at Chapel Hill, NC, USA
| | - Kunjie Hua
- Department of Genetics, University of North Carolina at Chapel Hill, NC, USA
| | - Daniel Pomp
- Department of Genetics, University of North Carolina at Chapel Hill, NC, USA
| | - James E Faber
- Departments of Cell Biology and Physiology, University of North Carolina at Chapel Hill, NC, USA
- McAllister Heart Institute, University of North Carolina at Chapel Hill, NC, USA
- Curriculum in Neurobiology, University of North Carolina at Chapel Hill, NC, USA
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12
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Edgar KS, Galvin OM, Collins A, Katusic ZS, McDonald DM. BH4-Mediated Enhancement of Endothelial Nitric Oxide Synthase Activity Reduces Hyperoxia-Induced Endothelial Damage and Preserves Vascular Integrity in the Neonate. Invest Ophthalmol Vis Sci 2017; 58:230-241. [PMID: 28114584 PMCID: PMC6039076 DOI: 10.1167/iovs.16-20523] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2016] [Accepted: 11/06/2016] [Indexed: 01/11/2023] Open
Abstract
Purpose Endothelial nitric oxide synthase (eNOS)-derived nitric oxide (NO) has important vasoprotective functions that are compromised in the vasodegenerative phase of retinopathy of prematurity, owing to hyperoxia-induced depletion of the essential NOS cofactor BH4. Because modulating eNOS function can be beneficial or detrimental, our aim was to investigate the effect of BH4 supplementation on eNOS function and vascular regression in hyperoxia. Methods Endothelial-specific eNOS-green fluorescent protein (GFP) overexpressing mice at postnatal day 7 (P7) were exposed to hyperoxia for 48 hours in the presence or absence of supplemental BH4, achieved by administration of sepiapterin, a stable BH4 precursor. Tissue was collected either for retinal flat mounts that were stained with lectin to determine the extent of vessel coverage or for analysis of BH4 by high-performance liquid chromatography, nitrotyrosine (NT) marker by Western blotting, VEGF expression by ELISA, and NOS activity by arginine-to-citrulline conversion. Primary retinal microvascular endothelial cells (RMEC) were similarly treated, and hyperoxia-induced damage was determined. Results Sepiapterin effectively enhanced BH4 levels in hyperoxia-exposed retinas and brains, elevated NOS activity, and reduced NT-modified protein, leading to reversal of the exacerbated vasoregression observed in the presence of eNOS overexpression. In RMECs, hyperoxia-mediated depletion of BH4 dysregulated the redox balance by reducing nitrite and elevating superoxide and impaired proliferative ability. BH4 supplementation restored normal RMEC proliferation in vitro and also in vivo, providing a mechanistic link with the enhanced vascular coverage in eNOS-GFP retinas. Conclusions These results demonstrate that BH4 supplementation corrects hyperoxia-induced RMEC dysfunction and preserves vascular integrity by enhancing eNOS function.
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Affiliation(s)
- Kevin S. Edgar
- Centre for Experimental Medicine, Queen's University Belfast, United Kingdom
| | - Orla M. Galvin
- Centre for Experimental Medicine, Queen's University Belfast, United Kingdom
| | - Anthony Collins
- Centre for Experimental Medicine, Queen's University Belfast, United Kingdom
| | - Zvonimir S. Katusic
- Department of Anesthesiology and Pharmacology, Mayo Clinic, Minnesota, United States
| | - Denise M. McDonald
- Centre for Experimental Medicine, Queen's University Belfast, United Kingdom
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13
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Biwer LA, Taddeo EP, Kenwood BM, Hoehn KL, Straub AC, Isakson BE. Two functionally distinct pools of eNOS in endothelium are facilitated by myoendothelial junction lipid composition. BIOCHIMICA ET BIOPHYSICA ACTA 2016; 1861:671-9. [PMID: 27106139 PMCID: PMC4869716 DOI: 10.1016/j.bbalip.2016.04.014] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Revised: 03/10/2016] [Accepted: 04/16/2016] [Indexed: 12/21/2022]
Abstract
In resistance arteries, endothelial cells (EC) make contact with smooth muscle cells (SMC), forming myoendothelial junctions (MEJ). Endothelial nitric oxide synthase (eNOS) is present in the luminal side of the EC (apical EC) and the basal side of the EC (MEJ). To test if these eNOS pools acted in sync or separately, we co-cultured ECs and SMCs, then stimulated SMCs with phenylephrine (PE). Adrenergic activation causes inositol [1,4,5] triphosphate (IP3) to move from SMC to EC through gap junctions at the MEJ. PE increases MEJ eNOS phosphorylation (eNOS-P) at S1177, but not in EC. Conversely, we used bradykinin (BK) to increase EC calcium; this increased EC eNOS-P but did not affect MEJ eNOS-P. Inhibiting gap junctions abrogated the MEJ eNOS-P after PE, but had no effect on BK eNOS-P. Differential lipid composition between apical EC and MEJ may account for the compartmentalized eNOS-P response. Indeed, DAG and phosphatidylserine are both enriched in MEJ. These lipids are cofactors for PKC activity, which was significantly increased at the MEJ after PE. Because PKC activity also relies on endoplasmic reticulum (ER) calcium release, we used thapsigargin and xestospongin C, BAPTA, and PKC inhibitors, which caused significant decreases in MEJ eNOS-P after PE. Functionally, BK inhibited leukocyte adhesion and PE caused an increase in SMC cGMP. We hypothesize that local lipid composition of the MEJ primes PKC and eNOS-P for stimulation by PE, allowing for compartmentalized function of eNOS in the blood vessel wall.
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Affiliation(s)
- Lauren A Biwer
- Department of Molecular Physiology and Biophysics, University of Virginia, USA; Robert M. Berne Cardiovascular Research Center, University of Virginia, USA
| | - Evan P Taddeo
- Department of Pharmacology, University of Virginia, USA
| | | | - Kyle L Hoehn
- Department of Pharmacology, University of Virginia, USA; School of Biotechnology and Biomolecular Sciences, University of New South Wales, Australia
| | - Adam C Straub
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, USA; Heart, Lung, Blood and Vascular Medicine Institute; University of Pittsburgh, USA
| | - Brant E Isakson
- Department of Molecular Physiology and Biophysics, University of Virginia, USA; Robert M. Berne Cardiovascular Research Center, University of Virginia, USA.
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14
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Krishnan M, Janardhanan P, Roman L, Reddick RL, Natarajan M, van Haperen R, Habib SL, de Crom R, Mohan S. Enhancing eNOS activity with simultaneous inhibition of IKKβ restores vascular function in Ins2(Akita+/-) type-1 diabetic mice. J Transl Med 2015; 95:1092-104. [PMID: 26214584 DOI: 10.1038/labinvest.2015.96] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2015] [Revised: 04/24/2015] [Accepted: 05/28/2015] [Indexed: 12/13/2022] Open
Abstract
The balance of nitric oxide (NO) versus superoxide generation has a major role in the initiation and progression of endothelial dysfunction. Under conditions of high glucose, endothelial nitric oxide synthase (eNOS) functions as a chief source of superoxide rather than NO. In order to improve NO bioavailability within the vessel wall in type-1 diabetes, we investigated treatment strategies that improve eNOS phosphorylation and NO-dependent vasorelaxation. We evaluated methods to increase the eNOS activity by (1) feeding Ins2(Akita) spontaneously diabetic (type-1) mice with l-arginine in the presence of sepiapterin, a precursor of tetrahydrobiopterin; (2) preventing eNOS/NO deregulation by the inclusion of inhibitor kappa B kinase beta (IKKβ) inhibitor, salsalate, in the diet regimen in combination with l-arginine and sepiapterin; and (3) independently increasing eNOS expression to improve eNOS activity and associated NO production through generating Ins2(Akita) diabetic mice that overexpress human eNOS predominantly in vascular endothelial cells. Our results clearly demonstrated that diet supplementation with l-arginine, sepiapterin along with salsalate improved phosphorylation of eNOS and enhanced vasorelaxation of thoracic/abdominal aorta in type-1 diabetic mice. More interestingly, despite the overexpression of eNOS, the in-house generated transgenic eNOS-GFP (TgeNOS-GFP)-Ins2(Akita) cross mice showed an unanticipated effect of reduced eNOS phosphorylation and enhanced superoxide production. Our results demonstrate that enhancement of endogenous eNOS activity by nutritional modulation is more beneficial than increasing the endogenous expression of eNOS by gene therapy modalities.
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Affiliation(s)
- Manickam Krishnan
- Department of Pathology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Preethi Janardhanan
- Department of Pathology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Linda Roman
- Department of Biochemistry, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Robert L Reddick
- Department of Pathology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Mohan Natarajan
- Department of Pathology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Rien van Haperen
- Department of Cell Biology and Genetics, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Samy L Habib
- Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Rini de Crom
- Department of Cell Biology and Genetics, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Sumathy Mohan
- Department of Pathology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
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15
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Chang JYH, Stamer WD, Bertrand J, Read AT, Marando CM, Ethier CR, Overby DR. Role of nitric oxide in murine conventional outflow physiology. Am J Physiol Cell Physiol 2015; 309:C205-14. [PMID: 26040898 DOI: 10.1152/ajpcell.00347.2014] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Accepted: 05/30/2015] [Indexed: 11/22/2022]
Abstract
Elevated intraocular pressure (IOP) is the main risk factor for glaucoma. Exogenous nitric oxide (NO) decreases IOP by increasing outflow facility, but whether endogenous NO production contributes to the physiological regulation of outflow facility is unclear. Outflow facility was measured by pressure-controlled perfusion in ex vivo eyes from C57BL/6 wild-type (WT) or transgenic mice expressing human endothelial NO synthase (eNOS) fused to green fluorescent protein (GFP) superimposed on the endogenously expressed murine eNOS (eNOS-GFPtg). In WT mice, exogenous NO delivered by 100 μM S-nitroso-N-acetylpenicillamine (SNAP) increased outflow facility by 62 ± 28% (SD) relative to control eyes perfused with the inactive SNAP analog N-acetyl-d-penicillamine (NAP; n = 5, P = 0.016). In contrast, in eyes from eNOS-GFPtg mice, SNAP had no effect on outflow facility relative to NAP (-9 ± 4%, P = 0.40). In WT mice, the nonselective NOS inhibitor N(G)-nitro-l-arginine methyl ester (l-NAME, 10 μM) decreased outflow facility by 36 ± 13% (n = 5 each, P = 0.012), but 100 μM l-NAME had no detectable effect on outflow facility (-16 ± 5%, P = 0.22). An eNOS-selective inhibitor (cavtratin, 50 μM) decreased outflow facility by 19 ± 12% in WT (P = 0.011) and 39 ± 25% in eNOS-GFPtg (P = 0.014) mice. In the conventional outflow pathway of eNOS-GFPtg mice, eNOS-GFP expression was localized to endothelial cells lining Schlemm's canal and the downstream vessels, with no apparent expression in the trabecular meshwork. These results suggest that endogenous NO production by eNOS within endothelial cells of Schlemm's canal or downstream vessels contributes to the physiological regulation of aqueous humor outflow facility in mice, representing a viable strategy to more successfully lower IOP in glaucoma.
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Affiliation(s)
- Jason Y H Chang
- Department of Bioengineering, Imperial College London, London, United Kingdom; Department of Ophthalmology, Duke University School of Medicine, Durham, North Carolina
| | - W Daniel Stamer
- Department of Ophthalmology, Duke University School of Medicine, Durham, North Carolina
| | - Jacques Bertrand
- Department of Bioengineering, Imperial College London, London, United Kingdom
| | - A Thomas Read
- Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, Ontario, Canada; and
| | - Catherine M Marando
- Department of Bioengineering, Imperial College London, London, United Kingdom
| | - C Ross Ethier
- Department of Bioengineering, Imperial College London, London, United Kingdom; Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia
| | - Darryl R Overby
- Department of Bioengineering, Imperial College London, London, United Kingdom;
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16
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Duncker DJ, van Deel ED, de Waard MC, de Boer M, Merkus D, van der Velden J. Exercise training in adverse cardiac remodeling. Pflugers Arch 2014; 466:1079-91. [PMID: 24573174 DOI: 10.1007/s00424-014-1464-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Revised: 01/27/2014] [Accepted: 01/28/2014] [Indexed: 12/14/2022]
Abstract
Cardiac remodeling in response to a myocardial infarction or chronic pressure-overload is an independent risk factor for the development of heart failure. In contrast, cardiac remodeling produced by regular physical exercise is associated with a decreased risk for heart failure. There is evidence that exercise training has a beneficial effect on disease progression and survival in patients with cardiac remodeling and dysfunction, but concern has also been expressed that exercise training may aggravate pathological remodeling and dysfunction. Here we present studies from our laboratory into the effects of exercise training on pathological cardiac remodeling and dysfunction in mice. The results indicate that even in the presence of a large infarct, exercise training exerts beneficial effects on the heart. These effects were mimicked in part by endothelial nitric oxide synthase (eNOS) overexpression and abrogated by eNOS deficiency, demonstrating the importance of nitric oxide signaling in mediating the cardiac effects of exercise. Exercise prior to a myocardial infarction was also cardioprotective. In contrast, exercise tended to aggravate pathological cardiac remodeling and dysfunction in the setting of pressure-overload produced by an aortic stenosis. These observations emphasize the critical importance of the underlying pathological stimulus for cardiac hypertrophy and remodeling, in determining the effects of exercise training. Future studies are needed to define the influence of exercise type, intensity and duration in different models and severities of pathological cardiac remodeling. Together such studies will aid in optimizing the therapy of exercise training in the setting of cardiovascular disease.
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Affiliation(s)
- Dirk J Duncker
- Division of Experimental Cardiology, Department of Cardiology, Thoraxcenter Erasmus MC University Medical Center Rotterdam, PO Box 2040, 3000, CA, Rotterdam, The Netherlands,
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17
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Warren CM, Ziyad S, Briot A, Der A, Iruela-Arispe ML. A ligand-independent VEGFR2 signaling pathway limits angiogenic responses in diabetes. Sci Signal 2014; 7:ra1. [PMID: 24399295 DOI: 10.1126/scisignal.2004235] [Citation(s) in RCA: 94] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Although vascular complications are a hallmark of diabetes, the molecular mechanisms that underlie endothelial dysfunction are unclear. We showed that reactive oxygen species generated from hyperglycemia promoted ligand-independent phosphorylation of vascular endothelial growth factor receptor 2 (VEGFR2). This VEGFR2 signaling occurred within the Golgi compartment and resulted in progressively decreased availability of VEGFR2 at the cell surface. Consequently, the responses of endothelial cells to exogenous VEGF in a mouse model of diabetes were impaired because of a specific deficiency of VEGFR2 at the cell surface, despite a lack of change in transcript abundance. Hyperglycemia-induced phosphorylation of VEGFR2 did not require intrinsic receptor kinase activity and was instead mediated by Src family kinases. The reduced cell surface abundance of VEGFR2 in diabetic mice was reversed by treatment with the antioxidant N-acetyl-L-cysteine, suggesting a causative role for oxidative stress. These findings uncover a mode of ligand-independent VEGFR2 signaling that can progressively lead to continuously muted responses to exogenous VEGF and limit angiogenic events.
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Affiliation(s)
- Carmen M Warren
- 1Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, CA 90095, USA
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18
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Heyne GW, Kiland JA, Kaufman PL, Gabelt BT. Effect of nitric oxide on anterior segment physiology in monkeys. Invest Ophthalmol Vis Sci 2013; 54:5103-10. [PMID: 23800771 DOI: 10.1167/iovs.12-11491] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To determine the effect of the nitric oxide donor, sodium nitroprusside (SNP), and the nitric oxide synthase (NOS) inhibitor, L-nitro-arginine-methylester (L-NAME), on IOP, mean arterial pressure (MAP), pupil diameter (PD), refraction (Rfx), aqueous humor formation (AHF), and outflow facility (OF) in monkeys. METHODS Monkeys were treated with single or multiple topical treatments of 500 μg SNP or L-NAME to one eye. IOP was determined by Goldmann applanation tonometry, PD with vernier calipers in room light, Rfx by Hartinger coincidence refractometry, AHF by fluorophotometry, and MAP with a blood pressure monitor. OF was determined by two-level constant pressure perfusion following anterior chamber exchange. RESULTS Following four topical treatments with 500 μg SNP, 30 minutes apart, IOP was significantly decreased from 2 to 6 hours compared with the contralateral control with the maximum IOP reduction of 20% at 3 hours (P < 0.001). PD, Rfx, and AHF were unchanged. Effects on MAP were variable. OF after SNP exchange was significantly increased by 77% (P < 0.05) at 10(-3) M. Topical L-NAME had no effect on IOP, PD, Rfx, or MAP. CONCLUSIONS Enhancement of nitric oxide concentration at targeted tissues in the anterior segment may be a useful approach for IOP reduction for glaucoma therapy. Additional studies are warranted before conclusions can be made regarding the effect of NOS inhibition on ocular physiology in nonhuman primates.
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Affiliation(s)
- Galen W Heyne
- Department of Ophthalmology and Visual Sciences, University of Wisconsin, Madison, Wisconsin, USA
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19
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Edgar K, Gardiner TA, van Haperen R, de Crom R, McDonald DM. eNOS overexpression exacerbates vascular closure in the obliterative phase of OIR and increases angiogenic drive in the subsequent proliferative stage. Invest Ophthalmol Vis Sci 2012; 53:6833-50. [PMID: 22930723 DOI: 10.1167/iovs.12-9797] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
PURPOSE In ischemic retinopathies, the misdirection of reparative angiogenesis away from the hypoxic retina leads to pathologic neovascularization. Thus, therapeutic strategies that reverse this trend would be extremely beneficial. Nitric oxide (NO) produced by endothelial nitric oxide synthase (eNOS) is an important mediator of vascular endothelial growth factor (VEGF) function facilitating vascular growth and maturation. However, in addition to NO, eNOS can also produce superoxide (O(2)(-)), exacerbating pathology. Here, our aim was to investigate the effect of eNOS overexpression on vascular closure and subsequent recovery of the ischemic retina. METHODS Mice overexpressing eNOS-GFP were subjected to oxygen-induced retinopathy (OIR) and changes in retinal vascularization quantified. Background angiogenic drive was assessed during vascular development and in aortic rings. NOS activity was measured by Griess assay or conversion of radiolabeled arginine to citrulline, nitrotyrosine (NT), and superoxide by immunolabeling and dihydroethidium fluorescence and VEGF by ELISA. RESULTS In response to hyperoxia, enhanced eNOS expression led to increased NOS-derived superoxide and dysfunctional NO production, NT accumulation, and exacerbated vessel closure associated with tetrahydrobiopterin (BH₄) insufficiency. Despite worse vaso-obliteration, eNOS overexpression resulted in elevated hypoxia-induced angiogenic drive, independent of VEGF production. This correlated with increased vascular branching similar to that observed in isolated aortas and during development. Enhanced recovery was also associated with neovascular tuft formation, which showed defective NO production and increased eNOS-derived superoxide and NT levels. CONCLUSIONS In hyperoxia, reduced BH₄ bioavailability causes overexpressed eNOS to become dysfunctional, exacerbating vaso-obliteration. In the proliferative phase, however, eNOS has important prorepair functions enhancing angiogenic growth potential and recovery in ischemia.
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Affiliation(s)
- Kevin Edgar
- Centre for Vision and Vascular Science, Queen's University Belfast, United Kingdom
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20
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van der Horst G, van der Pluijm G. Preclinical imaging of the cellular and molecular events in the multistep process of bone metastasis. Future Oncol 2012; 8:415-30. [DOI: 10.2217/fon.12.33] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Bone metastasis is a complex process that ultimately leads to devastating metastatic bone disease. It is therefore of key interest to unravel the mechanisms underlying the multistep process of skeletal metastasis and cancer-induced bone disease, and to develop better treatment and management of patients with this devastating disease. Fortunately, novel technologies are rapidly emerging that allow real-time imaging of molecules, pathogenic processes, drug delivery and drug response in preclinical in vivo models. The outcome of these experimental studies will facilitate clinical cancer research by improving the detection of cancer cell invasion, metastasis and therapy response.
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Affiliation(s)
- Geertje van der Horst
- Department of Urology, Leiden University Medical Center, J3–100, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
| | - Gabri van der Pluijm
- Department of Urology, Leiden University Medical Center, J3–100, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
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21
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Abstract
Control is intrinsic to biological organisms, whose cells are in a constant state of sensing and response to numerous external and self-generated stimuli. Diverse means are used to study the complexity through control-based approaches in these cellular systems, including through chemical and genetic manipulations, input-output methodologies, feedback approaches, and feed-forward approaches. We first discuss what happens in control-based approaches when we are not actively examining or manipulating cells. We then present potential methods to determine what the cell is doing during these times and to reverse-engineer the cellular system. Finally, we discuss how we can control the cell's extracellular and intracellular environments, both to probe the response of the cells using defined experimental engineering-based technologies and to anticipate what might be achieved by applying control-based approaches to affect cellular processes. Much work remains to apply simplified control models and develop new technologies to aid researchers in studying and utilizing cellular and molecular processes.
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Affiliation(s)
- Philip R LeDuc
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, USA.
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22
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van der Horst G, van der Pluijm G. Preclinical models that illuminate the bone metastasis cascade. Recent Results Cancer Res 2012; 192:1-31. [PMID: 22307368 DOI: 10.1007/978-3-642-21892-7_1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
In this chapter currently available preclinical models of tumor progression and bone metastasis, including genetically engineered mice that develop primary and metastatic carcinomas and transplantable animal models, will be described. Understanding the multistep process of incurable bone metastasis is pivotal to the development of new therapeutic strategies. Novel technologies for imaging molecules or pathologic processes in cancers and their surrounding stroma have emerged rapidly and have greatly facilitated cancer research, in particular the cellular behavior of osteotropic tumors and their response to new and existing therapeutic agents. Optical imaging, in particular, has become an important tool in preclinical bone metastasis models, clinical trials and medical practice. Advances in experimental and clinical imaging will-in the long run-result in significant improvements in diagnosis, tumor localization, enhanced drug delivery and treatment.
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Stamer WD, Lei Y, Boussommier-Calleja A, Overby DR, Ethier CR. eNOS, a pressure-dependent regulator of intraocular pressure. Invest Ophthalmol Vis Sci 2011; 52:9438-44. [PMID: 22039240 DOI: 10.1167/iovs.11-7839] [Citation(s) in RCA: 127] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Pathology in the primary drainage pathway for aqueous humor in the eye is responsible for ocular hypertension, the only treatable risk factor in patients with glaucoma. Unfortunately, the mechanisms that regulate pressure-dependent drainage of aqueous humor and thus intraocular pressure (IOP) are unknown. To better understand one possible underlying molecular factor that regulates IOP, nitric oxide (NO), pressure-dependent drainage in transgenic mice overexpressing endothelial NO synthase (eNOS) was studied. METHODS IOP was measured by rebound tonometry in mice, and pressure versus flow data were measured by ex vivo perfusion at multiple pressures between 8 and 45 mm Hg, using mock AH ±100 μM L-NAME. A subset of eyes was examined histologically using standard techniques or was assayed for fusion protein expression by Western blot analysis. RESULTS IOP was lower (9.6 ± 2.7 vs. 11.4 ± 2.5 mm Hg; mean ± SD; P = 0.04) and pressure-dependent drainage was higher (0.0154 ± 0.006 vs. 0.0066 ± 0.0009 μL/min/mm Hg; P = 0.002) in the transgenic mice than in the wild-type animals; however, pressure-independent drainage was unaffected. The NOS inhibitor L-NAME normalized pressure-dependent drainage in transgenic animals. For IOP >35 mm Hg, the slope of the pressure-flow curve in wild-type mice increased to match that seen in transgenic mice. Shear stress in the pressure-dependent pathway at elevated pressures was calculated to be in a range known to affect eNOS expression and activity in vascular endothelia. CONCLUSIONS Endothelial NOS overexpression lowers IOP by increasing pressure-dependent drainage in the mouse eye. Data are consistent with NO's having a mechanoregulatory role in aqueous humor dynamics, with eNOS induction at elevated IOPs leading to increased pressure-dependent outflow.
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Affiliation(s)
- W Daniel Stamer
- Department of Ophthalmology and Vision Science, University of Arizona, Tucson, Arizona, USA.
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Redding KM, Chen BL, Singh A, Re RN, Navar LG, Seth DM, Sigmund CD, Tang WW, Cook JL. Transgenic mice expressing an intracellular fluorescent fusion of angiotensin II demonstrate renal thrombotic microangiopathy and elevated blood pressure. Am J Physiol Heart Circ Physiol 2010; 298:H1807-18. [PMID: 20363893 PMCID: PMC2886647 DOI: 10.1152/ajpheart.00027.2010] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2010] [Accepted: 03/29/2010] [Indexed: 01/09/2023]
Abstract
We have generated transgenic mice that express angiotensin II (ANG II) fused downstream of enhanced cyan fluorescent protein, expression of which is regulated by the mouse metallothionein promoter. The fusion protein, which lacks a secretory signal, is retained intracellularly. In the present study, RT-PCR, immunoblot analyses, whole-animal fluorescent imaging, and fluorescent microscopy of murine embryonic fibroblasts confirm expression of the fusion protein in vivo and in vitro. The transgene is expressed in all tissues tested (including brain, heart, kidney, liver, lung, and testes), and radioimmunoassay of plasma samples obtained from transgenic mice indicate no increase in circulating ANG II over wild-type levels, consistent with intracellular retention of the transgene product. Kidneys from transgenic and corresponding wild-type littermates were histologically evaluated, and abnormalities in transgenic mice consistent with thrombotic microangiopathy were observed; microthrombosis was frequently observed within the glomerular capillaries and small vessels. In addition, systolic and diastolic blood pressures, measured by telemetry (n = 8 for each group), were significantly higher in transgenic mice compared with wild-type littermates. Blood pressure of line A male transgenic mice was 125 + or - 1.7 over 97 + or - 1.6 compared with 109 + or - 1.7 over 83 + or - 1.4 mmHg in wild-type littermates (systolic over diastolic). In summary, overexpression of an intracellular fluorescent fusion protein of ANG II correlates with elevated blood pressure and kidney pathology. This transgenic model may be useful to further explore the intracellular renin-angiotensin system and its implication in abnormal kidney function and hypertension.
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Affiliation(s)
| | | | - A. Singh
- Department of Molecular Genetics and
| | - R. N. Re
- Department of Cardiology, Ochsner Clinic Foundation, and
| | - L. G. Navar
- Department of Physiology, Tulane University Health Sciences Center, New Orleans, Louisiana
| | - D. M. Seth
- Department of Physiology, Tulane University Health Sciences Center, New Orleans, Louisiana
| | - C. D. Sigmund
- Department of Physiology, University of Iowa, Carver College of Medicine, Iowa City, Iowa; and
| | - W. W. Tang
- Department of Pathology, Ochsner Clinic Foundation, New Orleans, Louisiana
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Snoeks TJA, Löwik CWGM, Kaijzel EL. 'In vivo' optical approaches to angiogenesis imaging. Angiogenesis 2010; 13:135-47. [PMID: 20449766 PMCID: PMC2911541 DOI: 10.1007/s10456-010-9168-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2010] [Accepted: 04/20/2010] [Indexed: 10/27/2022]
Abstract
In recent years, molecular imaging gained significant importance in biomedical research. Optical imaging developed into a modality which enables the visualization and quantification of all kinds of cellular processes and cancerous cell growth in small animals. Novel gene reporter mice and cell lines and the development of targeted and cleavable fluorescent "smart" probes form a powerful imaging toolbox. The development of systems collecting tomographic bioluminescence and fluorescence data enabled even more spatial accuracy and more quantitative measurements. Here we describe various bioluminescent and fluorescent gene reporter models and probes that can be used to specifically image and quantify neovascularization or the angiogenic process itself.
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Affiliation(s)
- T J A Snoeks
- Department of Endocrinology, Leiden University Medical Center, Building 1, C4-R86, Albinusdreef 2, 2333ZA, Leiden, The Netherlands
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de Waard MC, van Haperen R, Soullié T, Tempel D, de Crom R, Duncker DJ. Beneficial effects of exercise training after myocardial infarction require full eNOS expression. J Mol Cell Cardiol 2010; 48:1041-9. [PMID: 20153335 DOI: 10.1016/j.yjmcc.2010.02.005] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2009] [Revised: 01/30/2010] [Accepted: 02/02/2010] [Indexed: 02/09/2023]
Abstract
Exercise training attenuates left ventricular (LV) dysfunction after myocardial infarction (MI). It could be speculated that these effects of exercise are mediated by increased endothelial NO synthase (eNOS) activity. In the present study we tested the hypothesis that eNOS plays a critical role in the exercise-induced amelioration of LV dysfunction after MI. MI or sham was induced in eNOS(-/-), eNOS(+/-) and eNOS(+/+) mice. After 8 weeks of voluntary wheel running (approximately 7 km/day in all groups) or sedentary housing, global cardiac function was determined in vivo and (immuno)histochemistry was performed to assess cardiomyocyte size, fibrosis, capillary density and apoptosis in remote myocardium. At baseline eNOS(-/-) mice had higher mean aortic pressure compared to eNOS(+/-) and eNOS(+/+) mice, but had normal global cardiac function. MI resulted in marked LV remodeling, including cardiomyocyte hypertrophy and a reduction in capillary density, increased fibrosis and apoptosis, as well as LV systolic and diastolic dysfunction to the same extent in all genotypes. In eNOS(+/+) MI mice exercise abolished fibrosis and apoptosis in the remote myocardium, attenuated LV systolic dysfunction and ameliorated pulmonary congestion. These beneficial effects were lost in eNOS(+/-) and eNOS(-/-) mice, while LV systolic dysfunction and pulmonary congestion in eNOS(+/-) mice were exacerbated by exercise. In conclusion, the beneficial effects of exercise after MI on LV remodeling and dysfunction depend critically on endogenous eNOS. The observation that the lack of one eNOS allele is sufficient to negate all beneficial effects of exercise, strongly suggests that exercise depends on full eNOS expression.
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Affiliation(s)
- Monique C de Waard
- Experimental Cardiology, Department of Cardiology, Thoraxcenter, Erasmus MC, University Medical Center Rotterdam, The Netherlands
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Qian J, Zhang Q, Church JE, Stepp DW, Rudic RD, Fulton DJR. Role of local production of endothelium-derived nitric oxide on cGMP signaling and S-nitrosylation. Am J Physiol Heart Circ Physiol 2010; 298:H112-8. [PMID: 19855060 PMCID: PMC3774418 DOI: 10.1152/ajpheart.00614.2009] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2009] [Accepted: 10/13/2009] [Indexed: 11/22/2022]
Abstract
Nitric oxide (NO), synthesized by endothelial nitric oxide synthase (eNOS), exerts control over vascular function via two distinct mechanisms, the activation of soluble guanylate cyclase (sGC)/cGMP-dependent signaling or through S-nitrosylation of proteins with reactive thiols (S-nitrosylation). Previous studies in cultured endothelial cells revealed that eNOS targeted to the plasma membrane (PM) releases greater amounts of NO compared with Golgi tethered eNOS. However, the significance of eNOS localization to sGC-dependent or -independent signaling is not known. Here we show that PM-targeted eNOS, when expressed in human aortic endothelial cells (HAEC) and isolated blood vessels, increases sGC/cGMP signaling to a greater extent than Golgi-localized eNOS. The ability of local NO production to influence sGC-independent mechanisms was also tested by monitoring the secretion of Von Willebrand factor (vWF), which is tonically inhibited by the S-nitrosylation of N-ethylmaleimide sensitive factor (NSF). In eNOS "knockdown" HAECs, vWF secretion was attenuated to a greater degree by PM eNOS compared with a Golgi-restricted eNOS. Moreover, the PM-targeted eNOS induced greater S-nitrosylation of NSF vs. Golgi eNOS. To distinguish between the amount of NO generated and the intracellular location of synthesis, we expressed Golgi and PM-targeted calcium-insensitive forms of eNOS in HAEC. These constructs, which generate equal amounts of NO regardless of location, produced equivalent increases in cGMP in bioassays and equal inhibition of vWF secretion. We conclude that the greater functional effects of PM eNOS are due to the increased amount of NO produced rather than effects derived from the local synthesis of NO.
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Affiliation(s)
- Jin Qian
- Vascular Biology Center, Medical College of Georgia, Augusta, GA 30912, USA
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28
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Staton CA, Reed MWR, Brown NJ. A critical analysis of current in vitro and in vivo angiogenesis assays. Int J Exp Pathol 2009; 90:195-221. [PMID: 19563606 DOI: 10.1111/j.1365-2613.2008.00633.x] [Citation(s) in RCA: 332] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The study of angiogenesis has grown exponentially over the past 40 years with the recognition that angiogenesis is essential for numerous pathologies and, more recently, with the advent of successful drugs to inhibit angiogenesis in tumours. The main problem with angiogenesis research remains the choice of appropriate assays to evaluate the efficacy of potential new drugs and to identify potential targets within the angiogenic process. This selection is made more complex by the recognition that heterogeneity occurs, not only within the endothelial cells themselves, but also within the specific microenvironment to be studied. Thus, it is essential to choose the assay conditions and cell types that most closely resemble the angiogenic disease being studied. This is especially important when aiming to translate data from in vitro to in vivo and from preclinical to the clinic. Here we critically review and highlight recent advances in the principle assays in common use including those for endothelial cell proliferation, migration, differentiation and co-culture with fibroblasts and mural cells in vitro, vessel outgrowth from organ cultures and in vivo assays such as chick chorioallantoic membrane (CAM), zebrafish, sponge implantation, corneal, dorsal air sac, chamber and tumour angiogenesis models. Finally, we briefly discuss the direction likely to be taken in future studies, which include the use of increasingly sophisticated imaging analysis systems for data acquisition.
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Affiliation(s)
- Carolyn A Staton
- Microcirculation Research Group, Academic Unit of Surgical Oncology, School of Medicine and Biomedical Sciences, University of Sheffield, Sheffield, UK.
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29
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North TE, Goessling W, Peeters M, Li P, Ceol C, Lord AM, Weber GJ, Harris J, Cutting CC, Huang P, Dzierzak E, Zon LI. Hematopoietic stem cell development is dependent on blood flow. Cell 2009; 137:736-48. [PMID: 19450519 DOI: 10.1016/j.cell.2009.04.023] [Citation(s) in RCA: 337] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2008] [Revised: 12/23/2008] [Accepted: 04/07/2009] [Indexed: 01/20/2023]
Abstract
During vertebrate embryogenesis, hematopoietic stem cells (HSCs) arise in the aorta-gonads-mesonephros (AGM) region. We report here that blood flow is a conserved regulator of HSC formation. In zebrafish, chemical blood flow modulators regulated HSC development, and silent heart (sih) embryos, lacking a heartbeat and blood circulation, exhibited severely reduced HSCs. Flow-modifying compounds primarily affected HSC induction after the onset of heartbeat; however, nitric oxide (NO) donors regulated HSC number even when treatment occurred before the initiation of circulation, and rescued HSCs in sih mutants. Morpholino knockdown of nos1 (nnos/enos) blocked HSC development, and its requirement was shown to be cell autonomous. In the mouse, Nos3 (eNos) was expressed in HSCs in the AGM. Intrauterine Nos inhibition or embryonic Nos3 deficiency resulted in a reduction of hematopoietic clusters and transplantable murine HSCs. This work links blood flow to AGM hematopoiesis and identifies NO as a conserved downstream regulator of HSC development.
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Affiliation(s)
- Trista E North
- Stem Cell Program and Hematology/Oncology, Children's Hospital, Howard Hughes Medical Institute, Harvard Stem Cell Institute, Harvard Medical School, Boston, MA 02115, USA
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30
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de Waard MC, van der Velden J, Boontje NM, Dekkers DHW, van Haperen R, Kuster DWD, Lamers JMJ, de Crom R, Duncker DJ. Detrimental effect of combined exercise training and eNOS overexpression on cardiac function after myocardial infarction. Am J Physiol Heart Circ Physiol 2009; 296:H1513-23. [PMID: 19286956 DOI: 10.1152/ajpheart.00485.2008] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
It has been reported that exercise after myocardial infarction (MI) attenuates left ventricular (LV) pump dysfunction by normalization of myofilament function. This benefit could be due to an exercise-induced upregulation of endothelial nitric oxide synthase (eNOS) expression and activity. Consequently, we first tested the hypothesis that the effects of exercise after MI can be mimicked by elevated eNOS expression using transgenic mice with overexpression of human eNOS (eNOSTg). Both exercise and eNOSTg attenuated LV remodeling and dysfunction after MI in mice and improved cardiomyocyte maximal force development (F(max)). However, only exercise training restored myofilament Ca(2+)-sensitivity and sarco(endo)plasmic reticulum Ca(2+)-ATPase (SERCA)2a protein levels and improved the first derivative of LV pressure at 30 mmHg. Conversely, only eNOSTg improved survival. In view of these partly complementary actions, we subsequently tested the hypothesis that combining exercise and eNOSTg would provide additional protection against LV remodeling and dysfunction after MI. Unexpectedly, the combination of exercise and eNOSTg abolished the beneficial effects on LV remodeling and dysfunction of either treatment alone. The latter was likely due to perturbations in Ca(2+) homeostasis, as myofilament F(max) actually increased despite marked reductions in the phosphorylation status of several myofilament proteins, whereas the exercise-induced increases in SERCA2a protein levels were lost in eNOSTg mice. Antioxidant treatment with N-acetylcysteine or supplementation of tetrahydrobiopterin and l-arginine prevented these detrimental effects on LV function while partly restoring the phosphorylation status of myofilament proteins and further enhancing myofilament F(max). In conclusion, the combination of exercise and elevated eNOS expression abolished the cardioprotective effects of either treatment alone after MI, which appeared to be, at least in part, the result of increased oxidative stress secondary to eNOS "uncoupling."
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Affiliation(s)
- Monique C de Waard
- Div. of Experimental Cardiology, Dept. of Cardiology, Thoraxcenter, Erasmus Univ. Medical Center, PO Box 2040, Rotterdam 3000 CA, The Netherlands
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31
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Cheng C, Tempel D, Oostlander A, Helderman F, Gijsen F, Wentzel J, van Haperen R, Haitsma DB, Serruys PW, van der Steen AFW, de Crom R, Krams R. Rapamycin modulates the eNOS vs. shear stress relationship. Cardiovasc Res 2007; 78:123-9. [PMID: 18079107 DOI: 10.1093/cvr/cvm103] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
AIMS Studies in animals and patients indicate that rapamycin affects vasodilatation differently in outer and inner curvatures of blood vessels. We evaluated in this study whether rapamycin affects endothelial nitric oxide synthase (eNOS) responsiveness to shear stress under normo- and hypercholesteraemic conditions to explain these findings. METHODS AND RESULTS Shear stress levels were varied over a large range of values in carotid arteries of transgenic mice expressing human eNOS fused to enhanced green fluorescence protein. The mice were divided into control, low-dose rapamycin (3 microg/kg/day), and high-dose rapamycin (3 mg/kg/day) groups and into normocholesteraemic and hypercholesteraemic (ApoE-/- on high cholesterol diet for 3-4 weeks) groups. The effect of rapamycin treatment on eNOS was evaluated by quantification of eNOS expression and of intracellular protein levels by en face confocal microscopy. A sigmoid curve fit was used to described these data. The efficacy of treatment was confirmed by measurement of rapamycin serum levels (2.0 +/- 0.5 ng/mL), and of p27kip1 expression in vascular tissue (increased by 2.4 +/- 0.5-fold). In control carotid arteries, eNOS expression increased by 1.8 +/- 0.3-fold in response to rapamycin. In the treated vessels, rapamycin reduced maximal eNOS expression at high shear stress levels (>5 Pa) in a dose-dependent way and shifted the sigmoid curve to the right. Hypercholesteraemia had a tendency to increase the leftward shift and the reduction in maximal eNOS expression (P = 0.07). CONCLUSION Rapamycin is associated with high eNOS in low shear regions, i.e. in atherogenic regions, protecting these regions against atherosclerosis, and is associated with a reduction of eNOS at high shear stress affecting vasomotion in these regions.
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Affiliation(s)
- Caroline Cheng
- Department of Cardiology, Thoraxcenter, Erasmus University Medical Center, Rotterdam, The Netherlands
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Murata T, Lin MI, Huang Y, Yu J, Bauer PM, Giordano FJ, Sessa WC. Reexpression of caveolin-1 in endothelium rescues the vascular, cardiac, and pulmonary defects in global caveolin-1 knockout mice. ACTA ACUST UNITED AC 2007; 204:2373-82. [PMID: 17893196 PMCID: PMC2118452 DOI: 10.1084/jem.20062340] [Citation(s) in RCA: 201] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Caveolin-1 (Cav-1) is the principal structural component of caveolae organelles in smooth muscle cells, adipocytes, fibroblasts, epithelial cells, and endothelial cells (ECs). Cav-1–deficient (Cav-1 knockout [KO]) mice are viable and show increases of nitric oxide (NO) production in vasculature, cardiomyopathy, and pulmonary dysfunction. In this study, we generated EC-specific Cav-1–reconstituted (Cav-1 RC) mice and reexamined vascular, cardiac, and pulmonary phenotypes. Cav-1 KO pulmonary arteries had decreased smooth muscle contractility and increased endothelial NO synthase activation and hypotension; the latter two effects were rescued completely in Cav-1 RC mice. Cav-1 KO mice exhibited myocardial hypertrophy, pulmonary hypertension, and alveolar cell hyperproliferation caused by constitutive activation of p42/44 mitogen-activated protein kinase and Akt. Interestingly, in Cav-1 RC mice, cardiac hypertrophy and pulmonary hypertension were completely rescued, whereas alveolar hyperplasia was partially recovered because of the lack of rescue of Cav-1 in bronchiolar epithelial cells. These results provide clear physiological evidence supporting the important role of cell type–specific Cav-1 expression governing multiple phenotypes in the vasculature, heart, and lung.
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Affiliation(s)
- Takahisa Murata
- Department of Pharmacology and Program in Vascular Cell Signaling and Therapeutics, Boyer Center for Molecular Medicine, Yale University School of Medicine, New Haven, CT 06511
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33
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Mees B, Wagner S, Ninci E, Tribulova S, Martin S, van Haperen R, Kostin S, Heil M, de Crom R, Schaper W. Endothelial nitric oxide synthase activity is essential for vasodilation during blood flow recovery but not for arteriogenesis. Arterioscler Thromb Vasc Biol 2007; 27:1926-33. [PMID: 17556651 DOI: 10.1161/atvbaha.107.145375] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
OBJECTIVE Arteriogenesis is the major mechanism of vascular growth, which is able to compensate for blood flow deficiency after arterial occlusion. Endothelial nitric oxide synthase (eNOS) activity is essential for neovascularization, however its specific role in arteriogenesis remains unclear. We studied the role of eNOS in arteriogenesis using 3 mouse strains with different eNOS expression. METHODS AND RESULTS Distal femoral artery ligation was performed in eNOS-overexpressing mice (eNOStg), eNOS-deficient (eNOS-/-) mice, and wild type (WT) controls. Tissue perfusion and collateral-dependent blood flow were significantly increased in eNOStg mice compared with WT only immediately after ligation. In eNOS-/- mice, although tissue perfusion remained significantly decreased, collateral-dependent blood flow was only decreased until day 7, suggesting normal, perhaps delayed collateral growth. Histology confirmed no differences in collateral arteries of eNOStg, eNOS-/-, and WT mice at 1 and 3 weeks. Administration of an NO donor induced vasodilation in collateral arteries of eNOS-/- mice, but not in WT, identifying the inability to vasodilate collateral arteries as main cause of impaired blood flow recovery in eNOS-/- mice. CONCLUSIONS This study demonstrates that eNOS activity is crucial for NO-mediated vasodilation of peripheral collateral vessels after arterial occlusion but not for collateral artery growth.
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Affiliation(s)
- Barend Mees
- Department of Cell Biology & Genetics, Erasmus University MC Rotterdam, Dr. Molewaterplein 50, 3015 GE Rotterdam, The Netherlands.
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34
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van Deel ED, Merkus D, van Haperen R, de Waard MC, de Crom R, Duncker DJ. Vasomotor control in mice overexpressing human endothelial nitric oxide synthase. Am J Physiol Heart Circ Physiol 2007; 293:H1144-53. [PMID: 17496213 DOI: 10.1152/ajpheart.00773.2006] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Nitric oxide (NO) plays a key role in regulating vascular tone. Mice overexpressing endothelial NO synthase [eNOS-transgenic (Tg)] have a 20% lower systemic vascular resistance (SVR) than wild-type (WT) mice. However, because eNOS enzyme activity is 10 times higher in tissue homogenates from eNOS-Tg mice, this in vivo effect is relatively small. We hypothesized that the effect of eNOS overexpression is attenuated by alterations in NO signaling and/or altered contribution of other vasoregulatory pathways. In isoflurane-anesthetized open-chest mice, eNOS inhibition produced a significantly greater increase in SVR in eNOS-Tg mice compared with WT mice, consistent with increased NO synthesis. Vasodilation to sodium nitroprusside (SNP) was reduced, whereas the vasodilator responses to phosphodiesterase-5 blockade and 8-bromo-cGMP (8-Br-cGMP) were maintained in eNOS-Tg compared with WT mice, indicating blunted responsiveness of guanylyl cyclase to NO, which was supported by reduced guanylyl cyclase activity. There was no evidence of eNOS uncoupling, because scavenging of reactive oxygen species (ROS) produced even less vasodilation in eNOS-Tg mice, whereas after eNOS inhibition the vasodilator response to ROS scavenging was similar in WT and eNOS-Tg mice. Interestingly, inhibition of other modulators of vascular tone [including cyclooxygenase, cytochrome P-450 2C9, endothelin, adenosine, and Ca-activated K(+) channels] did not significantly affect SVR in either eNOS-Tg or WT mice, whereas the marked vasoconstrictor responses to ATP-sensitive K(+) and voltage-dependent K(+) channel blockade were similar in WT and eNOS-Tg mice. In conclusion, the vasodilator effects of eNOS overexpression are attenuated by a blunted NO responsiveness, likely at the level of guanylyl cyclase, without evidence of eNOS uncoupling or adaptations in other vasoregulatory pathways.
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Affiliation(s)
- Elza D van Deel
- Experimental Cardiology, Thoraxcenter, Erasmus MC, University Medical Center Rotterdam, The Netherlands
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35
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Riou S, Mees B, Esposito B, Merval R, Vilar J, Stengel D, Ninio E, van Haperen R, de Crom R, Tedgui A, Lehoux S. High Pressure Promotes Monocyte Adhesion to the Vascular Wall. Circ Res 2007; 100:1226-33. [PMID: 17395876 DOI: 10.1161/01.res.0000265231.59354.2c] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Hypertension is a known risk factor for the development of atherosclerosis. To assess how mechanical factors contribute to this process, mouse carotid arteries were maintained in organ culture at normal (80 mm Hg) or high (150 mm Hg) intraluminal pressure for 1, 6, 12, or 24 hours. Thereafter, fluorescent human monocytic cells (U937) were injected intraluminally and allowed to adhere for 30 minutes before washout. U937 adhesion was increased in vessels kept at 150 mm Hg 12 hours (23.5+/-5.7 versus 9.9+/-2.2 cells/mm at 80 mm Hg; P<0.05) or 24 hours (26.7+/-5.7 versus 8.8+/-1.5 cells/mm; P<0.05). At 24 hours, high pressure was associated with increased mRNA expression of monocyte chemoattractant protein-1, interleukin-6, keratinocyte-derived chemokine, and vascular cell adhesion molecule-1 (6.9+/-2.1, 4.4+/-0.1, 9.8+/-2.8, and 2.4+/-0.1-fold respectively; P<0.05), as assessed by quantitative RT-PCR and corroborated by immunohistochemistry, which also revealed an increase in intracellular adhesion molecule-1 expression. Nuclear factor kappaB inhibition using SN50 peptide abolished the overexpression of chemokines and adhesion molecules and reduced U937 adhesion in vessels at 150 mm Hg. Moreover, treatment of vessels and cells with specific neutralizing antibodies established that monocyte chemoattractant protein-1, interleukin-6, and keratinocyte-derived chemokine released from vessels at 150 mm Hg primed the monocytes, increasing their adhesion to vascular cell adhesion molecule-1 but not intracellular adhesion molecule-1 via alpha4beta1 integrins. The additive effect of chemokines on the adhesion of U937 cells to vascular cell adhesion molecule-1 was confirmed by in vitro assay. Finally, pressure-dependent U937 adhesion was blunted in arteries from mice overexpressing endothelial NO synthase. Hence, high intraluminal pressure induces cytokine and adhesion molecule expression via nuclear factor kappaB, leading to monocytic cell adhesion. These results indicate that hypertension may directly contribute to the development of atherosclerosis through nuclear factor kappaB induction.
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Affiliation(s)
- Stéphanie Riou
- INSERM U689, Centre de Recherche Cardiovasculaire Inserm Lariboisière, Paris, France
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36
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Yu J, Bergaya S, Murata T, Alp IF, Bauer MP, Lin MI, Drab M, Kurzchalia TV, Stan RV, Sessa WC. Direct evidence for the role of caveolin-1 and caveolae in mechanotransduction and remodeling of blood vessels. J Clin Invest 2006; 116:1284-91. [PMID: 16670769 PMCID: PMC1451207 DOI: 10.1172/jci27100] [Citation(s) in RCA: 285] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2005] [Accepted: 01/17/2006] [Indexed: 02/04/2023] Open
Abstract
Caveolae in endothelial cells have been implicated as plasma membrane microdomains that sense or transduce hemodynamic changes into biochemical signals that regulate vascular function. Therefore we compared long- and short-term flow-mediated mechanotransduction in vessels from WT mice, caveolin-1 knockout (Cav-1 KO) mice, and Cav-1 KO mice reconstituted with a transgene expressing Cav-1 specifically in endothelial cells (Cav-1 RC mice). Arterial remodeling during chronic changes in flow and shear stress were initially examined in these mice. Ligation of the left external carotid for 14 days to lower blood flow in the common carotid artery reduced the lumen diameter of carotid arteries from WT and Cav-1 RC mice. In Cav-1 KO mice, the decrease in blood flow did not reduce the lumen diameter but paradoxically increased wall thickness and cellular proliferation. In addition, in isolated pressurized carotid arteries, flow-mediated dilation was markedly reduced in Cav-1 KO arteries compared with those of WT mice. This impairment in response to flow was rescued by reconstituting Cav-1 into the endothelium. In conclusion, these results showed that endothelial Cav-1 and caveolae are necessary for both rapid and long-term mechanotransduction in intact blood vessels.
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Affiliation(s)
- Jun Yu
- Department of Pharmacology and Program in Vascular Cell Signaling and Therapeutics, Boyer Center for Molecular Medicine, Yale University School of Medicine, New Haven, Connecticut, USA.
Max Planck Institute for Molecular Cell Biology and Genetics, Dresden, Germany.
Department of Pathology, Dartmouth Medical School, Hanover, New Hampshire, USA
| | - Sonia Bergaya
- Department of Pharmacology and Program in Vascular Cell Signaling and Therapeutics, Boyer Center for Molecular Medicine, Yale University School of Medicine, New Haven, Connecticut, USA.
Max Planck Institute for Molecular Cell Biology and Genetics, Dresden, Germany.
Department of Pathology, Dartmouth Medical School, Hanover, New Hampshire, USA
| | - Takahisa Murata
- Department of Pharmacology and Program in Vascular Cell Signaling and Therapeutics, Boyer Center for Molecular Medicine, Yale University School of Medicine, New Haven, Connecticut, USA.
Max Planck Institute for Molecular Cell Biology and Genetics, Dresden, Germany.
Department of Pathology, Dartmouth Medical School, Hanover, New Hampshire, USA
| | - Ilkay F. Alp
- Department of Pharmacology and Program in Vascular Cell Signaling and Therapeutics, Boyer Center for Molecular Medicine, Yale University School of Medicine, New Haven, Connecticut, USA.
Max Planck Institute for Molecular Cell Biology and Genetics, Dresden, Germany.
Department of Pathology, Dartmouth Medical School, Hanover, New Hampshire, USA
| | - Michael P. Bauer
- Department of Pharmacology and Program in Vascular Cell Signaling and Therapeutics, Boyer Center for Molecular Medicine, Yale University School of Medicine, New Haven, Connecticut, USA.
Max Planck Institute for Molecular Cell Biology and Genetics, Dresden, Germany.
Department of Pathology, Dartmouth Medical School, Hanover, New Hampshire, USA
| | - Michelle I. Lin
- Department of Pharmacology and Program in Vascular Cell Signaling and Therapeutics, Boyer Center for Molecular Medicine, Yale University School of Medicine, New Haven, Connecticut, USA.
Max Planck Institute for Molecular Cell Biology and Genetics, Dresden, Germany.
Department of Pathology, Dartmouth Medical School, Hanover, New Hampshire, USA
| | - Marek Drab
- Department of Pharmacology and Program in Vascular Cell Signaling and Therapeutics, Boyer Center for Molecular Medicine, Yale University School of Medicine, New Haven, Connecticut, USA.
Max Planck Institute for Molecular Cell Biology and Genetics, Dresden, Germany.
Department of Pathology, Dartmouth Medical School, Hanover, New Hampshire, USA
| | - Teymuras V. Kurzchalia
- Department of Pharmacology and Program in Vascular Cell Signaling and Therapeutics, Boyer Center for Molecular Medicine, Yale University School of Medicine, New Haven, Connecticut, USA.
Max Planck Institute for Molecular Cell Biology and Genetics, Dresden, Germany.
Department of Pathology, Dartmouth Medical School, Hanover, New Hampshire, USA
| | - Radu V. Stan
- Department of Pharmacology and Program in Vascular Cell Signaling and Therapeutics, Boyer Center for Molecular Medicine, Yale University School of Medicine, New Haven, Connecticut, USA.
Max Planck Institute for Molecular Cell Biology and Genetics, Dresden, Germany.
Department of Pathology, Dartmouth Medical School, Hanover, New Hampshire, USA
| | - William C. Sessa
- Department of Pharmacology and Program in Vascular Cell Signaling and Therapeutics, Boyer Center for Molecular Medicine, Yale University School of Medicine, New Haven, Connecticut, USA.
Max Planck Institute for Molecular Cell Biology and Genetics, Dresden, Germany.
Department of Pathology, Dartmouth Medical School, Hanover, New Hampshire, USA
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Gambillara V, Chambaz C, Montorzi G, Roy S, Stergiopulos N, Silacci P. Plaque-prone hemodynamics impair endothelial function in pig carotid arteries. Am J Physiol Heart Circ Physiol 2006; 290:H2320-8. [PMID: 16415081 DOI: 10.1152/ajpheart.00486.2005] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Hemodynamic forces play an active role in vascular pathologies, particularly in relation to the localization of atherosclerotic lesions. It has been established that low shear stress combined with cyclic reversal of flow direction (oscillatory shear stress) affects the endothelial cells and may lead to an initiation of plaque development. The aim of the study was to analyze the effect of hemodynamic conditions in arterial segments perfused in vitro in the absence of other stimuli. Left common porcine carotid segments were mounted into an ex vivo arterial support system and perfused for 3 days under unidirectional high and low shear stress (6 ± 3 and 0.3 ± 0.1 dyn/cm2) and oscillatory shear stress (0.3 ± 3 dyn/cm2). Bradykinin-induced vasorelaxation was drastically decreased in arteries exposed to oscillatory shear stress compared with unidirectional shear stress. Impaired nitric oxide-mediated vasodilation was correlated to changes in both endothelial nitric oxide synthase (eNOS) gene expression and activation in response to bradykinin treatment. This study determined the flow-mediated effects on native tissue perfused with physiologically relevant flows and supports the hypothesis that oscillatory shear stress is a determinant factor in early stages of atherosclerosis. Indeed, oscillatory shear stress induces an endothelial dysfunction, whereas unidirectional shear stress preserves the function of endothelial cells. Endothelial dysfunction is directly mediated by a downregulation of eNOS gene expression and activation; consequently, a decrease of nitric oxide production and/or bioavailability occurs.
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Affiliation(s)
- Veronica Gambillara
- Laboratory of Hemodynamics and Cardiovascular Technology, Federal Institute of Technology, 1015 Lausanne, Switzerland.
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38
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Loomans CJM, Wan H, de Crom R, van Haperen R, de Boer HC, Leenen PJM, Drexhage HA, Rabelink TJ, van Zonneveld AJ, Staal FJT. Angiogenic murine endothelial progenitor cells are derived from a myeloid bone marrow fraction and can be identified by endothelial NO synthase expression. Arterioscler Thromb Vasc Biol 2006; 26:1760-7. [PMID: 16728651 DOI: 10.1161/01.atv.0000229243.49320.c9] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Endothelial progenitor cells (EPCs) contribute to postnatal neovascularization and are therefore of great interest for autologous cell therapies to treat ischemic vascular disease. However, the origin and functional properties of these EPCs are still in debate. METHODS AND RESULTS Here, ex vivo expanded murine EPCs were characterized in terms of phenotype, lineage potential, differentiation from bone marrow (BM) precursors, and their functional properties using endothelial NO synthase (eNOS)-green fluorescent protein transgenic mice. Despite high phenotypic overlap with macrophages and dendritic cells, EPCs displayed unique eNOS expression, endothelial lineage potential in colony assays, and angiogenic characteristics, but also immunologic properties such as interleukin-12p70 production and low levels of T-cell stimulation. The majority of EPCs developed from an immature, CD31(+)Ly6C+ myeloid progenitor fraction in the BM. Addition of myeloid growth factors such as macrophage-colony-stimulating factor (M-CSF) and granulocyte/macrophage (GM)-CSF stimulated the expansion of spleen-derived EPCs but not BM-derived EPCs. CONCLUSIONS The close relationship between EPCs and other myeloid lineages may add to the complexity of using them in cell therapy. Our mouse model could be a highly useful tool to characterize EPCs functionally and phenotypically, to explore the origin and optimize the isolation of EPC fractions for therapeutic neovascularization.
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Affiliation(s)
- C J M Loomans
- Department of Immunology, Erasmus Medical Center, Dr Molewaterplein 50, 3015GE Rotterdam, Netherlands
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39
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Gan Y, Shen YH, Utama B, Wang J, Coselli J, Wang XL. Dual effects of histone deacetylase inhibition by trichostatin A on endothelial nitric oxide synthase expression in endothelial cells. Biochem Biophys Res Commun 2006; 340:29-34. [PMID: 16338217 DOI: 10.1016/j.bbrc.2005.11.151] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2005] [Accepted: 11/22/2005] [Indexed: 10/25/2022]
Abstract
Inhibition of histone deacetylases by trichostatin A (TSA) has pleiotropic effects on gene expression. We demonstrated that at low dose (0.1 microg) TSA increased the eNOS mRNA levels, which was followed by a time- and dose-dependent down-regulation. Cycloheximide, a protein synthesis inhibitor, completely abolished TSA-induced decrease in eNOS expression, indicating that new protein synthesis is required for the inhibiting effect. Mevastatin--an inhibitor HMG-CoA reductase and geranylgeranylation reaction dose-dependently antagonized TSA-induced reduction. This mevastatin-mediated antagonism was completely abolished by geranylgeranylpyrophosphate, suggesting that geranylgeranyl modification is needed to activate the eNOS mRNA destabilizing factor--a mechanism responsible for statin-mediated eNOS upregulation.
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Affiliation(s)
- Yehua Gan
- Laboratory of Molecular Biology and Center for TMJ Disorders, Peking University School of Stomatology, Beijing 100081, China
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40
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Hemodynamic manipulation of eNOS in vivo. Blood 2005. [DOI: 10.1182/blood-2005-09-3685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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41
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Davies PF, Spaan JA, Krams R. Shear Stress Biology of the Endothelium. Ann Biomed Eng 2005; 33:1714-8. [PMID: 16389518 DOI: 10.1007/s10439-005-8774-0] [Citation(s) in RCA: 140] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2003] [Accepted: 06/06/2005] [Indexed: 12/31/2022]
Abstract
The relationships between blood flow, mechanotransduction, and the localization of arterial lesions can now be advanced by the incorporation of new technologies and the refinement of existing methods in imaging modalities, computational modeling, fluid dynamics, and high throughput genomics and proteomics. When combined with traditional cell and molecular technologies, a powerful palette of investigative approaches is available to address shear stress biology of the endothelium at levels extending from nanoscale subcellular detailed mechanistic responses through to higher organizational levels of regional endothelial phenotypes and heterogeneous vascular beds.
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Affiliation(s)
- Peter F Davies
- Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, PA, 19104, USA.
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42
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Cheng C, van Haperen R, de Waard M, van Damme LCA, Tempel D, Hanemaaijer L, van Cappellen GWA, Bos J, Slager CJ, Duncker DJ, van der Steen AFW, de Crom R, Krams R. Shear stress affects the intracellular distribution of eNOS: direct demonstration by a novel in vivo technique. Blood 2005; 106:3691-8. [PMID: 16105973 DOI: 10.1182/blood-2005-06-2326] [Citation(s) in RCA: 191] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The focal location of atherosclerosis in the vascular tree is correlated with local variations in shear stress. We developed a method to induce defined variations in shear stress in a straight vessel segment of a mouse. To this end, a cylinder with a tapered lumen was placed around the carotid artery, inducing a high shear stress field. Concomitantly, regions of low shear stress and oscillatory shear stress were created upstream and down-stream of the device, respectively. This device was used in mice transgenic for an eNOS3GFP fusion gene. We observed a strong induction of endothelial nitric oxide synthase-green fluorescent protein (eNOS-GFP) mRNA expression in the high shear stress region compared with the other regions (P < .05). Quantification of eNOS-GFP fluorescence or of immunoreactivity to the Golgi complex or to platelet endothelial cell adhesion molecule 1 (PECAM-1) showed an increase in the high shear stress region (P < .05) compared with nontreated carotid arteries. Colocalization of eNOS-GFP with either the Golgi complex or PECAM-1 also responded to alterations of shear stress. In conclusion, we showed a direct response of mRNA and protein expression in vivo to induced variations of shear stress. This model provides the opportunity to study the relationship between shear stress alterations, gene expression, and atherosclerosis.
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Affiliation(s)
- Caroline Cheng
- Department of Cardiology, Erasmus University Medical Center, Rotterdam, The Netherlands
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43
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Panda K, Chawla-Sarkar M, Santos C, Koeck T, Erzurum SC, Parkinson JF, Stuehr DJ. Visualizing inducible nitric-oxide synthase in living cells with a heme-binding fluorescent inhibitor. Proc Natl Acad Sci U S A 2005; 102:10117-22. [PMID: 16006534 PMCID: PMC1177357 DOI: 10.1073/pnas.0408972102] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2004] [Indexed: 12/30/2022] Open
Abstract
The study of nitric-oxide synthase (NOS) physiology is constrained by the lack of suitable probes to detect NOS in living cells or animals. Here, we characterized a fluorescent inducible NOS (iNOS) inhibitor called PIF (pyrimidine imidazole FITC) and examined its utility for microscopic imaging of iNOS in living cells. PIF binding to iNOS displayed high affinity, isoform selectivity, and heme specificity, and was essentially irreversible. PIF was used to successfully image iNOS expressed in RAW264.7 cells, HEK293T cells, human A549 epithelial cells, and freshly obtained human lung epithelium. PIF was used to estimate a half-life for iNOS of 1.8 h in HEK293T cells. Our work reveals that fluorescent probes like PIF will be valuable for studying iNOS cell biology and in understanding the pathophysiology of diseases that involve dysfunctional iNOS expression.
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Affiliation(s)
- Koustubh Panda
- Department of Immunology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA.
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44
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Gan Y, Shen YH, Wang J, Wang X, Utama B, Wang J, Wang XL. Role of histone deacetylation in cell-specific expression of endothelial nitric-oxide synthase. J Biol Chem 2005; 280:16467-75. [PMID: 15722551 PMCID: PMC1283144 DOI: 10.1074/jbc.m412960200] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Histone acetylation plays an important role in chromatin remodeling and gene expression. The molecular mechanisms involved in cell-specific expression of endothelial nitric-oxide synthase (eNOS) are not fully understood. In this study we investigated whether histone deacetylation was involved in repression of eNOS expression in non-endothelial cells. Induction of eNOS expression by histone deacetylase (HDAC) inhibitors trichostatin A (TSA) and sodium butyrate was observed in all four different types of non-endothelial cells examined. Chromatin immunoprecipitation assays showed that the induction of eNOS expression by TSA was accompanied by a remarkable increase of acetylation of histone H3 associated with the eNOS 5'-flanking region in the non-endothelial cells. Moreover, DNA methylation-mediated repression of eNOS promoter activity was partially reversed by TSA treatment, and combined treatment of TSA and 5-aza-2'-deoxycytidine (AzadC) synergistically induced eNOS expression in non-endothelial cells. The proximal Sp1 site is critical for basal activity of eNOS promoter. The induction of eNOS by inhibition of HDACs in non-endothelial cells, however, appeared not mediated by the changes in Sp1 DNA binding activity. We further showed that Sp1 bound to the endogenous eNOS promoter and associated with HDAC1 in non-endothelial HeLa cells. Combined TSA and AzadC treatment increased Sp1 binding to the endogenous eNOS promoter but decreased the association between HDAC1 and Sp1 in HeLa cells. Our data suggest that HDAC1 plays a critical role in eNOS repression, and the proximal Sp1 site may serve a key target for HDCA1-mediated eNOS repression in non-endothelial cells.
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Affiliation(s)
- Yehua Gan
- From the Division of Cardiothoracic Surgery, Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, Texas 77030 and
- Center for TMJ Disorders, Peking University School of Stomatology, Beijing 100081, China
| | - Ying H. Shen
- From the Division of Cardiothoracic Surgery, Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, Texas 77030 and
| | - Jian Wang
- From the Division of Cardiothoracic Surgery, Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, Texas 77030 and
| | - Xinwen Wang
- From the Division of Cardiothoracic Surgery, Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, Texas 77030 and
| | - Budi Utama
- From the Division of Cardiothoracic Surgery, Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, Texas 77030 and
| | - Jing Wang
- From the Division of Cardiothoracic Surgery, Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, Texas 77030 and
| | - Xing Li Wang
- From the Division of Cardiothoracic Surgery, Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, Texas 77030 and
- ¶ An American Heart Association Established Investigator. To whom correspondence should be addressed: Michael E. DeBakey, Dept. of Surgery, MS NAB 2010, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030. Tel.: 713-798-5485; Fax: 713-798-1705; E-mail:
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Merkus D, Brzezinska AK, Zhang C, Saito S, Chilian WM. Cardiac myocytes control release of endothelin-1 in coronary vasculature. Am J Physiol Heart Circ Physiol 2005; 288:H2088-92. [PMID: 15637126 DOI: 10.1152/ajpheart.00522.2003] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Alpha-adrenergic vasoconstriction in the coronary circulation is mediated through alpha-adrenoceptors on cardiac myocytes and subsequent release of endothelin, a very potent, long-lasting vasoconstrictor. Recent studies found that adult cardiac myocytes do not express the preproendothelin gene. Thus we hypothesized that alpha-adrenoceptor stimulation on the cardiac myocytes results in the production of an endothelin-releasing factor, which stimulates the coronary vasculature to produce endothelin. We tested this hypothesis by using an in vitro model in which isolated adult rat cardiac myocytes can be stimulated with an alpha-adrenoceptor agonist (phenylephrine). Their bathing fluid is then transferred to isolated coronary arterioles, and vasoactive responses are measured. To identify the source of endothelin, the endothelin-converting enzyme inhibitor phosphoramidon was added to either the myocytes or the isolated arterioles. Phenylephrine enhanced the vasoconstrictor properties of the myocyte bathing fluid. Administration of phosphoramidon (in either the presence or the absence of phenylephrine) to the myocytes had no effect on the vasoactive properties of the bathing fluid. In contrast, administration of phosphoramidon to the isolated arteriole before administration of the bathing fluid converted vasoconstriction to vasodilation, similar to the effect of the endothelin A receptor antagonist JKC-301, indicating that the endothelin is indeed produced by the coronary vasculature. Administration of the angiotensin type 1 receptor antagonist losartan to the vessel bath enhanced vasodilation to the bathing fluid of the phenylephrine-treated but not control myocytes. In conclusion, during alpha-adrenergic activation cardiac myocytes release a factor, probably angiotensin II, that stimulates the vascular production of endothelin. Although the physiological implications of this mechanism are not obvious, this may represent a protective mechanism that integrates neuronal vasoconstrictor mechanisms with myocardial metabolism, which minimizes periods of both coronary underperfusion and overperfusion.
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Affiliation(s)
- Daphne Merkus
- Experimental Cardiology, Thoraxcenter, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands.
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46
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McDonald DM, Alp NJ, Channon KM. Functional comparison of the endothelial nitric oxide synthase Glu298Asp polymorphic variants in human endothelial cells. ACTA ACUST UNITED AC 2004; 14:831-9. [PMID: 15608562 DOI: 10.1097/00008571-200412000-00006] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The G894T endothelial nitric oxide synthase (eNOS) polymorphism results in a Glu to Asp substitution at position 298. This position is located externally on the protein and as the regulation of eNOS is dependent on its subcellular localization and interaction with modulatory proteins, we aimed to address whether the substitution of Asp at 298 had any effect on these mechanisms. Initially, we developed a novel method to accurately determine molar quantities of each variant by expressing them as green fluorescent protein (GFP) fusion proteins and using recombinant adenoviruses to facilitate transient infection of human microvascular endothelial cells. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis and Western blotting of eNOSAsp revealed a 135-kDa proteolytic fragment which was not present with eNOSGlu. This proteolysis was prevented by using LDS buffer confirming that this differential cleavage is an artefact of sample preparation and unlikely to occur intracellularly. Nitric oxide was measured following stimulation with calcium ionophore or oestrogen in the presence of varying sepiapterin concentrations. GFP fluorescence was used to quantify the amount of fusion protein and calculate intracellular specific activity. There was no significant difference in intracellular specific activity between Glu and Asp eNOS in response to calcium ionophore or oestrogen. Tetrahydrobiopterin supplementation increased eNOS activity of both variants in an identical manner. The presence of the GFP also facilitated the visualization of the variants by confocal microscopy and demonstrated that both localized to the plasma membrane and the Golgi. These findings demonstrate that the Asp substitution at 298 does not have a major effect in modulating eNOS activity in vivo.
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Affiliation(s)
- Denise M McDonald
- Department of Cardiovascular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, UK.
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47
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Fulton D, Babbitt R, Zoellner S, Fontana J, Acevedo L, McCabe TJ, Iwakiri Y, Sessa WC. Targeting of endothelial nitric-oxide synthase to the cytoplasmic face of the Golgi complex or plasma membrane regulates Akt- versus calcium-dependent mechanisms for nitric oxide release. J Biol Chem 2004; 279:30349-57. [PMID: 15136572 DOI: 10.1074/jbc.m402155200] [Citation(s) in RCA: 109] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The heterogeneous localization of endothelial nitricoxide synthase (eNOS) on the Golgi complex versus the plasma membrane has made it difficult to dissect the regulation of each pool of enzyme. Here, we generated fusion proteins that specifically target the plasma membrane or cytoplasmic aspects of the Golgi complex and have assessed eNOS activation. Plasma membrane-targeted eNOS constructs were constitutively active, phosphorylated, and responsive to transmembrane calcium fluxes, yet were insensitive to further activation by Akt-mediated phosphorylation. In contrast, cis-Golgi complex-targeted eNOS behaved similarly to wild-type eNOS and was less sensitive to calcium-dependent activation and highly responsive to Akt-dependent phosphorylation compared with plasma membrane versions. In plasma membrane- and Golgi complex-targeted constructs, Ser1179 is critical for NO production. This study provides clear evidence for functional roles of plasma membrane- and Golgi complex-localized eNOS and supports the concept that proteins thought to be regulated and to function exclusively in the plasma membrane of cells can indeed signal and be regulated in internal Golgi membranes.
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Affiliation(s)
- David Fulton
- Department of Pharmacology and the Program in Vascular Cell Signaling and Therapeutics, Boyer Center for Molecular Medicine, Yale University School of Medicine, New Haven, Connecticut 06536-0812, USA
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48
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Seki T, Hong KH, Yun J, Kim SJ, Oh SP. Isolation of a Regulatory Region of Activin Receptor-Like Kinase 1 Gene Sufficient for Arterial Endothelium-Specific Expression. Circ Res 2004; 94:e72-7. [PMID: 15059937 DOI: 10.1161/01.res.0000127048.81744.31] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Activin receptor-like kinase 1 (Acvrl1; Alk1) is a type I receptor for transforming growth factor-beta (TGF-beta). ALK1 plays a pivotal role in vascular development and is involved in the development of hereditary hemorrhagic telangiectasia 2 (HHT2), a dominantly inherited vascular disorder, and pulmonary hypertension. We have previously shown that Alk1 is expressed predominantly in arterial endothelial cells (ECs). Despite recent discoveries of a number of artery-specific genes, the regulatory elements of these genes have not been characterized. To investigate the cis-acting elements essential for the artery-specific Alk1 expression, we have generated a series of transgenic constructs with various lengths and regions of Alk1 genomic fragments connected to a LacZ reporter gene, and analyzed the reporter gene expression in transgenic mice. We found that a 9.2-kb genomic fragment, which includes 2.7-kb promoter region and the entire intron 2, is sufficient to drive arterial endothelium-specific expression. The defined regulatory region, as well as the transgenic mouse lines, would be invaluable resources in studying the mechanisms underlying angiogenesis, arteriogenesis, and vascular disorders, such as HHT and pulmonary hypertension. The full text of this article is available online at http://circres.ahajournals.org.
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MESH Headings
- Activin Receptors, Type I/biosynthesis
- Activin Receptors, Type I/genetics
- Activin Receptors, Type I/physiology
- Activin Receptors, Type II
- Animals
- Arteries/cytology
- Arteries/embryology
- Arteries/growth & development
- Arteries/metabolism
- Binding Sites
- Consensus Sequence
- Endothelium, Vascular/metabolism
- Exons/genetics
- Female
- Gene Expression Regulation, Developmental
- Genes, Reporter
- Humans
- Introns/genetics
- Lac Operon
- Male
- Mice
- Mice, Transgenic
- Neovascularization, Physiologic/genetics
- Organ Specificity
- Promoter Regions, Genetic/genetics
- Regulatory Sequences, Nucleic Acid
- Sequence Alignment
- Sequence Homology
- Skin/injuries
- Species Specificity
- Transcription Factors/metabolism
- Wound Healing/genetics
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Affiliation(s)
- Tsugio Seki
- Department of Physiology and Functional Genomics, University of Florida,Gainesville, Fla 32610, USA
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