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Buonfiglio F, Xia N, Yüksel C, Manicam C, Jiang S, Zadeh JK, Musayeva A, Elksne E, Pfeiffer N, Patzak A, Li H, Gericke A. Studies on the Effects of Hypercholesterolemia on Mouse Ophthalmic Artery Reactivity. Diseases 2023; 11:124. [PMID: 37873768 PMCID: PMC10594501 DOI: 10.3390/diseases11040124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 09/10/2023] [Accepted: 09/18/2023] [Indexed: 10/25/2023] Open
Abstract
Atherogenic lipoproteins may impair vascular reactivity, leading to tissue damage in various organs, including the eye. This study aimed to investigate whether ophthalmic artery reactivity is affected in mice lacking the apolipoprotein E gene (ApoE-/-), a model for hypercholesterolemia and atherosclerosis. Twelve-month-old male ApoE-/- mice and age-matched wild-type controls were used to assess vascular reactivity using videomicroscopy. Moreover, the vascular mechanics, lipid content, levels of reactive oxygen species (ROS), and expression of pro-oxidant redox enzymes and the lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) were determined in vascular tissue. Unlike the aorta, the ophthalmic artery of ApoE-/- mice developed no signs of endothelial dysfunction and no signs of excessive lipid deposition. Remarkably, the levels of ROS, nicotinamide adenine dinucleotide phosphate oxidase 1 (NOX1), NOX2, NOX4, and LOX-1 were increased in the aorta but not in the ophthalmic artery of ApoE-/- mice. Our findings suggest that ApoE-/- mice develop endothelial dysfunction in the aorta by increased oxidative stress via the involvement of LOX-1, NOX1, and NOX2, whereas NOX4 may participate in media remodeling. In contrast, the ophthalmic artery appears to be resistant to chronic apolipoprotein E deficiency. A lack of LOX-1 expression/overexpression in response to increased oxidized low-density lipoprotein levels may be a possible mechanism of action.
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Affiliation(s)
- Francesco Buonfiglio
- Department of Ophthalmology, University Medical Center, Johannes Gutenberg University Mainz, Langenbeckstr. 1, 55131 Mainz, Germany
| | - Ning Xia
- Department of Pharmacology, University Medical Center, Johannes Gutenberg University Mainz, Langenbeckstr. 1, 55131 Mainz, Germany
| | - Can Yüksel
- Department of Ophthalmology, University Medical Center, Johannes Gutenberg University Mainz, Langenbeckstr. 1, 55131 Mainz, Germany
| | - Caroline Manicam
- Department of Ophthalmology, University Medical Center, Johannes Gutenberg University Mainz, Langenbeckstr. 1, 55131 Mainz, Germany
| | - Subao Jiang
- Department of Ophthalmology, University Medical Center, Johannes Gutenberg University Mainz, Langenbeckstr. 1, 55131 Mainz, Germany
| | - Jenia Kouchek Zadeh
- Department of Ophthalmology, University Medical Center, Johannes Gutenberg University Mainz, Langenbeckstr. 1, 55131 Mainz, Germany
| | - Aytan Musayeva
- Department of Ophthalmology, University Medical Center, Johannes Gutenberg University Mainz, Langenbeckstr. 1, 55131 Mainz, Germany
| | - Eva Elksne
- Department of Ophthalmology, University Medical Center, Johannes Gutenberg University Mainz, Langenbeckstr. 1, 55131 Mainz, Germany
| | - Norbert Pfeiffer
- Department of Ophthalmology, University Medical Center, Johannes Gutenberg University Mainz, Langenbeckstr. 1, 55131 Mainz, Germany
| | - Andreas Patzak
- Institute of Translational Physiology, Charité—Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
| | - Huige Li
- Department of Pharmacology, University Medical Center, Johannes Gutenberg University Mainz, Langenbeckstr. 1, 55131 Mainz, Germany
| | - Adrian Gericke
- Department of Ophthalmology, University Medical Center, Johannes Gutenberg University Mainz, Langenbeckstr. 1, 55131 Mainz, Germany
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Numaga-Tomita T, Shimauchi T, Kato Y, Nishiyama K, Nishimura A, Sakata K, Inada H, Kita S, Iwamoto T, Nabekura J, Birnbaumer L, Mori Y, Nishida M. Inhibition of transient receptor potential cation channel 6 promotes capillary arterialization during post-ischaemic blood flow recovery. Br J Pharmacol 2023; 180:94-110. [PMID: 36068079 PMCID: PMC10092707 DOI: 10.1111/bph.15942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 08/29/2022] [Accepted: 08/31/2022] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND AND PURPOSE Capillary arterialization, characterized by the coverage of pre-existing or nascent capillary vessels with vascular smooth muscle cells (VSMCs), is critical for the development of collateral arterioles to improve post-ischaemic blood flow. We previously demonstrated that the inhibition of transient receptor potential 6 subfamily C, member 6 (TRPC6) channels facilitate contractile differentiation of VSMCs under ischaemic stress. We here investigated whether TRPC6 inhibition promotes post-ischaemic blood flow recovery through capillary arterialization in vivo. EXPERIMENTAL APPROACH Mice were subjected to hindlimb ischaemia by ligating left femoral artery. The recovery rate of peripheral blood flow was calculated by the ratio of ischaemic left leg to non-ischaemic right one. The number and diameter of blood vessels were analysed by immunohistochemistry. Expression and phosphorylation levels of TRPC6 proteins were determined by western blotting and immunohistochemistry. KEY RESULTS Although the post-ischaemic blood flow recovery is reportedly dependent on endothelium-dependent relaxing factors, systemic TRPC6 deletion significantly promoted blood flow recovery under the condition that nitric oxide or prostacyclin production were inhibited, accompanying capillary arterialization. Cilostazol, a clinically approved drug for peripheral arterial disease, facilitates blood flow recovery by inactivating TRPC6 via phosphorylation at Thr69 in VSMCs. Furthermore, inhibition of TRPC6 channel activity by pyrazole-2 (Pyr2; BTP2; YM-58483) promoted post-ischaemic blood flow recovery in Apolipoprotein E-knockout mice. CONCLUSION AND IMPLICATIONS Suppression of TRPC6 channel activity in VSMCs could be a new strategy for the improvement of post-ischaemic peripheral blood circulation.
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Affiliation(s)
- Takuro Numaga-Tomita
- National Institute for Physiological Sciences (NIPS), National Institutes of Natural Sciences, Aichi, Japan.,Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, Aichi, Japan.,SOKENDAI (School of Life Science, The Graduate University for Advanced Studies), Aichi, Japan.,Shinshu University School of Medicine, Nagano, Japan
| | - Tsukasa Shimauchi
- National Institute for Physiological Sciences (NIPS), National Institutes of Natural Sciences, Aichi, Japan.,Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, Aichi, Japan.,Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan.,Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Yuri Kato
- Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan
| | - Kazuhiro Nishiyama
- Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan
| | - Akiyuki Nishimura
- National Institute for Physiological Sciences (NIPS), National Institutes of Natural Sciences, Aichi, Japan.,Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, Aichi, Japan.,SOKENDAI (School of Life Science, The Graduate University for Advanced Studies), Aichi, Japan
| | - Kosuke Sakata
- Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan
| | - Hiroyuki Inada
- National Institute for Physiological Sciences (NIPS), National Institutes of Natural Sciences, Aichi, Japan
| | - Satomi Kita
- Faculty of Medicine, Fukuoka University, Fukuoka, Japan.,Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Tokushima, Japan
| | | | - Junichi Nabekura
- National Institute for Physiological Sciences (NIPS), National Institutes of Natural Sciences, Aichi, Japan
| | - Lutz Birnbaumer
- NIEHS, NIH, Research Triangle Park, North Carolina, USA.,Institute for Biomedical Research (BIOMED), Catholic University of Argentina, Buenos Aires, Argentina
| | - Yasuo Mori
- Graduate School of Engineering, Kyoto University, Kyoto, Japan
| | - Motohiro Nishida
- National Institute for Physiological Sciences (NIPS), National Institutes of Natural Sciences, Aichi, Japan.,Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, Aichi, Japan.,SOKENDAI (School of Life Science, The Graduate University for Advanced Studies), Aichi, Japan.,Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan
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3
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Apolipoprotein E Deficiency Causes Endothelial Dysfunction in the Mouse Retina. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2019; 2019:5181429. [PMID: 31781340 PMCID: PMC6875001 DOI: 10.1155/2019/5181429] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 09/25/2019] [Accepted: 10/16/2019] [Indexed: 02/06/2023]
Abstract
Objective Atherogenic lipoproteins may impair vascular reactivity consecutively causing tissue damage in multiple organs via abnormal perfusion and excessive reactive oxygen species generation. We tested the hypothesis that chronic hypercholesterolemia causes endothelial dysfunction and cell loss in the retina. Methods Twelve-month-old apolipoprotein E-deficient (ApoE-/-) mice and age-matched wild-type controls were used in this study (n = 8 per genotype for each experiment). Intraocular pressure, blood pressure, and ocular perfusion pressure were determined. Retinal arteriole responses were studied in vitro, and reactive oxygen and nitrogen species were quantified in the retinal and optic nerve cryosections. The expression of the lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) and the NADPH oxidase isoforms, NOX1, NOX2, and NOX4, were determined in retinal cryosections by immunofluorescence microscopy. Pro- and antioxidant redox genes were quantified in retinal explants by PCR. Moreover, cell number in the retinal ganglion cell layer and axon number in the optic nerve was calculated. Results Responses to the endothelium-dependent vasodilator, acetylcholine, were markedly impaired in retinal arterioles of ApoE-/- mice (P < 0.01). LOX-1 (P = 0.0007) and NOX2 (P = 0.0027) expressions as well as levels of reactive oxygen species (P = 0.0022) were increased in blood vessels but not in other retinal structures. In contrast, reactive nitrogen species were barely detectable in both mouse genotypes. Messenger RNA for HIF-1α, VEGF-A, NOX1, and NOX2, but also for various antioxidant redox genes was elevated in the retina of ApoE-/- mice. Total cell number in the retinal ganglion cell layer did not differ between ApoE-/- and wild-type mice (P = 0.2171). Also, axon number in the optic nerve did not differ between ApoE-/- and wild-type mice (P = 0.6435). Conclusion Apolipoprotein E deficiency induces oxidative stress and endothelial dysfunction in retinal arterioles, which may trigger hypoxia in the retinal tissue. Oxidative stress in nonvascular retinal tissue appears to be prevented by the upregulation of antioxidant redox enzymes, resulting in neuron preservation.
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Lu J, Sun M, Wu X, Yuan X, Liu Z, Qu X, Ji X, Merriman TR, Li C. Urate-lowering therapy alleviates atherosclerosis inflammatory response factors and neointimal lesions in a mouse model of induced carotid atherosclerosis. FEBS J 2019; 286:1346-1359. [PMID: 30690853 PMCID: PMC6849826 DOI: 10.1111/febs.14768] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Revised: 11/10/2018] [Accepted: 01/23/2019] [Indexed: 12/18/2022]
Abstract
Hyperuricemia (HU) is a cause of gout. Clinical studies show a link between HU and cardiovascular disease. However, the role of soluble serum urate (SU) on atherosclerosis development remains elusive. We aimed to use a new HU mouse model [Uricase/Uox knockout (KO)] to further investigate the relationship between HU and atherosclerosis. A mouse model by perivascular collar placement of induced carotid atherosclerosis was established in male Uox-KO mice. The Uox-KO mice had elevated SU levels and enhanced levels of atherosclerosis inflammatory response proteins. In contrast, Uox-KO mice with carotid atherosclerosis showed severe neointimal changes in histology staining consistent with increases in intimal area and increases in proliferating cell nuclear antigen (PCNA)- and F4/80-positive cells. Allopurinol reduced neointimal areas induced by the perivascular collar in hyperuricemic mice, accompanied by decreased expression of PCNA- and F4/80-positive cells. Urate-lowering treatment alleviated atherosclerosis inflammatory response factors and reactive oxygen species (ROS) intensities in both collar placement Uox-KO mice and urate-stimulated human umbilical vein endothelial cells (HUVECs). In vitro results using HUVECs showed ROS was induced by urate and ROS induction was abrogated using antioxidants. These data demonstrate that urate per se does not trigger atherosclerosis intima lesions in male mice. Urate worsens carotid neointimal lesions induced by the perivascular collar and urate-lowering therapy partially abrogates the effects. The current study warrants clinical studies on the possible benefits of urate-lowering therapy in atherosclerosis patients with HU.
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Affiliation(s)
- Jie Lu
- Institute of Metabolic Diseases, Qingdao University, China.,Shandong Provincial Key Laboratory of Metabolic Diseases and Qingdao Key Laboratory of Gout, The Affiliated Hospital of Qingdao University, China.,Department of Endocrinology and Metabolic Diseases, The Affiliated Hospital of Qingdao University, China
| | - Mingshu Sun
- Institute of Metabolic Diseases, Qingdao University, China.,Shandong Provincial Key Laboratory of Metabolic Diseases and Qingdao Key Laboratory of Gout, The Affiliated Hospital of Qingdao University, China.,Department of Rheumatology and Clinical Immunology, The Affiliated Hospital of Qingdao University, China
| | - Xinjiang Wu
- Institute of Metabolic Diseases, Qingdao University, China
| | - Xuan Yuan
- Institute of Metabolic Diseases, Qingdao University, China
| | - Zhen Liu
- Institute of Metabolic Diseases, Qingdao University, China.,Shandong Provincial Key Laboratory of Metabolic Diseases and Qingdao Key Laboratory of Gout, The Affiliated Hospital of Qingdao University, China
| | - Xiaojie Qu
- Institute of Metabolic Diseases, Qingdao University, China.,Shandong Provincial Key Laboratory of Metabolic Diseases and Qingdao Key Laboratory of Gout, The Affiliated Hospital of Qingdao University, China.,Department of Endocrinology and Metabolic Diseases, The Affiliated Hospital of Qingdao University, China
| | - Xiaopeng Ji
- Institute of Metabolic Diseases, Qingdao University, China.,Shandong Provincial Key Laboratory of Metabolic Diseases and Qingdao Key Laboratory of Gout, The Affiliated Hospital of Qingdao University, China
| | - Tony R Merriman
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
| | - Changgui Li
- Institute of Metabolic Diseases, Qingdao University, China.,Shandong Provincial Key Laboratory of Metabolic Diseases and Qingdao Key Laboratory of Gout, The Affiliated Hospital of Qingdao University, China.,Department of Endocrinology and Metabolic Diseases, The Affiliated Hospital of Qingdao University, China
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5
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Ye X, Beckett T, Bagher P, Garland CJ, Dora KA. VEGF-A inhibits agonist-mediated Ca 2+ responses and activation of IK Ca channels in mouse resistance artery endothelial cells. J Physiol 2018; 596:3553-3566. [PMID: 29862503 DOI: 10.1113/jp275793] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 05/15/2018] [Indexed: 01/06/2023] Open
Abstract
KEY POINTS Prolonged exposure to vascular endothelial growth factor A (VEGF-A) inhibits agonist-mediated endothelial cell Ca2+ release and subsequent activation of intermediate conductance Ca2+ -activated K+ (IKCa ) channels, which underpins vasodilatation as a result of endothelium-dependent hyperpolarization (EDH) in mouse resistance arteries. Signalling via mitogen-activated protein/extracellular signal-regulated kinase kinase (MEK) downstream of VEGF-A was required to attenuate endothelial cell Ca2+ responses and the EDH-vasodilatation mediated by IKCa activation. VEGF-A exposure did not modify vasodilatation as a result of the direct activation of IKCa channels, nor the pattern of expression of inositol 1,4,5-trisphosphate receptor 1 within endothelial cells of resistance arteries. These results indicate a novel role for VEGF-A in resistance arteries and suggest a new avenue for investigation into the role of VEGF-A in cardiovascular diseases. ABSTRACT Vascular endothelial growth factor A (VEGF-A) is a potent permeability and angiogenic factor that is also associated with the remodelling of the microvasculature. Elevated VEGF-A levels are linked to a significant increase in the risk of cardiovascular dysfunction, although it is unclear how VEGF-A has a detrimental, disease-related effect. Small resistance arteries are central determinants of peripheral resistance and endothelium-dependent hyperpolarization (EDH) is the predominant mechanism by which these arteries vasodilate. Using isolated, pressurized resistance arteries, we demonstrate that VEGF-A acts via VEGF receptor-2 (R2) to inhibit both endothelial cell (EC) Ca2+ release and the associated EDH vasodilatation mediated by intermediate conductance Ca2+ -activated K+ (IKCa ) channels. Importantly, VEGF-A had no direct effect against IKCa channels. Instead, the inhibition was crucially reliant on the downstream activation of the mitogen-activated protein/extracellular signal-regulated kinase kinase 1/2 (MEK1/2). The distribution of EC inositol 1,4,5-trisphosphate (IP3 ) receptor-1 (R1) was not affected by exposure to VEGF-A and we propose an inhibition of IP3 R1 through the MEK pathway, probably via ERK1/2. Inhibition of EC Ca2+ via VEGFR2 has profound implications for EDH-mediated dilatation of resistance arteries and could provide a mechanism by which elevated VEGF-A contributes towards cardiovascular dysfunction.
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Affiliation(s)
- Xi Ye
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, UK
| | - Taylor Beckett
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, UK.,School of Biomedical Sciences, University of Queensland, Brisbane, Australia
| | - Pooneh Bagher
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, UK.,Department of Medical Physiology, College of Medicine, Texas A&M University Health Science Center, Bryan, TX, USA
| | | | - Kim A Dora
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, UK
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6
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Patel J, Chuaiphichai S, Douglas G, Gorvin CM, Channon KM. Vascular wall regulator of G-protein signalling-1 (RGS-1) is required for angiotensin II-mediated blood pressure control. Vascul Pharmacol 2018; 108:15-22. [PMID: 29654907 PMCID: PMC6073721 DOI: 10.1016/j.vph.2018.04.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Revised: 03/18/2018] [Accepted: 04/05/2018] [Indexed: 02/07/2023]
Abstract
G-Protein coupled receptors (GPCRs) activate intracellular signalling pathways by coupling to heterotrimeric G-proteins that control many physiological processes including blood pressure homeostasis. The Regulator of G-Protein Signalling-1 (RGS1) controls the magnitude and duration of downstream GPCR signalling by acting as a GTPase-activating protein for specific Gα-proteins. RGS1 has contrasting roles in haematopoietic and non-haematopoietic cells. Rgs1−/−ApoE−/− mice are protected from Angiotensin II (Ang II)-induced aortic aneurysm rupture. Conversely, Ang II treatment increases systolic blood pressure to a greater extent in Rgs1−/−ApoE−/− mice than ApoE−/− mice, independent of its role in myeloid cells. However the precise role of RGS1 in hypertension and vascular-derived cells remains unknown. We determined the effects of Rgs1 deletion on vascular function in ApoE−/− mice. Rgs1 deletion led to enhanced vasoconstriction in aortas and mesenteric arteries from ApoE−/− mice in response to phenylephrine (PE) and U46619 respectively. Rgs1 was shown to have a role in the vasculature, with endothelium-dependent vasodilation being impaired, and endothelium-independent dilatation to SNP being enhanced in Rgs1−/−ApoE−/− mesenteric arteries. To address the downstream signalling pathways in vascular smooth muscle cells (VSMCs) in response to Ang II-stimulation, we assessed pErk1/2, pJNK and pp38 MAPK activation in VSMCs transiently transfected with Rgs1. pErk1/2 signalling but not pJNK and pp38 signalling was impaired in the presence of Rgs1. Furthermore, we demonstrated that the enhanced contractile response to PE in Rgs1−/−ApoE−/− aortas was reduced by a MAPK/Erk (MEK) inhibitor and an L-type voltage gated calcium channel antagonist, suggesting that Erk1/2 signalling and calcium influx are major effectors of Rgs1-mediated vascular contractile responses, respectively. These findings indicate RGS1 is a novel regulator of blood pressure homeostasis and highlight RGS1-controlled signalling pathways in the vasculature that may be new drug development targets for hypertension.
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MESH Headings
- Angiotensin II
- Animals
- Aorta, Thoracic/metabolism
- Aorta, Thoracic/physiopathology
- Blood Pressure/genetics
- Calcium Signaling
- Cell Line
- Disease Models, Animal
- Hypertension/chemically induced
- Hypertension/genetics
- Hypertension/metabolism
- Hypertension/physiopathology
- Male
- Mesenteric Arteries/metabolism
- Mesenteric Arteries/physiopathology
- Mice, Knockout, ApoE
- Mitogen-Activated Protein Kinase 1/metabolism
- Mitogen-Activated Protein Kinase 3/metabolism
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/physiopathology
- Phosphorylation
- RGS Proteins/deficiency
- RGS Proteins/genetics
- RGS Proteins/metabolism
- Receptor, Angiotensin, Type 1/metabolism
- Vasoconstriction
- Vasodilation
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Affiliation(s)
- Jyoti Patel
- Division of Cardiovascular Medicine, British Heart Foundation Centre of Research Excellence, Radcliffe Department of Medicine, John Radcliffe Hospital, University of Oxford, Oxford, OX3 9DU, UK; Wellcome Centre for Human Genetics, University of Oxford, Oxford, OX3 7BN, UK.
| | - Surawee Chuaiphichai
- Division of Cardiovascular Medicine, British Heart Foundation Centre of Research Excellence, Radcliffe Department of Medicine, John Radcliffe Hospital, University of Oxford, Oxford, OX3 9DU, UK; Wellcome Centre for Human Genetics, University of Oxford, Oxford, OX3 7BN, UK
| | - Gillian Douglas
- Division of Cardiovascular Medicine, British Heart Foundation Centre of Research Excellence, Radcliffe Department of Medicine, John Radcliffe Hospital, University of Oxford, Oxford, OX3 9DU, UK; Wellcome Centre for Human Genetics, University of Oxford, Oxford, OX3 7BN, UK
| | - Caroline M Gorvin
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology, and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, OX3 7LE, UK
| | - Keith M Channon
- Division of Cardiovascular Medicine, British Heart Foundation Centre of Research Excellence, Radcliffe Department of Medicine, John Radcliffe Hospital, University of Oxford, Oxford, OX3 9DU, UK; Wellcome Centre for Human Genetics, University of Oxford, Oxford, OX3 7BN, UK
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Bondarenko AI, Panasiuk O, Okhai I, Montecucco F, Brandt KJ, Mach F. Ca 2+-dependent potassium channels and cannabinoid signaling in the endothelium of apolipoprotein E knockout mice before plaque formation. J Mol Cell Cardiol 2018; 115:54-63. [PMID: 29305938 DOI: 10.1016/j.yjmcc.2018.01.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Revised: 12/30/2017] [Accepted: 01/02/2018] [Indexed: 01/06/2023]
Abstract
Endothelial Ca2+-dependent K+ channels (KCa) regulate endothelial function. We also know that stimulation of type 2 cannabinoid (CB2) receptors ameliorates atherosclerosis. However, whether atherosclerosis is accompanied by altered endothelial KCa- and CB2 receptor-dependent signaling is unknown. By utilizing an in situ patch-clamp approach, we directly evaluated the KCa channel function and the CB2 receptor-dependent electrical responses in the endothelium of aortic strips from young ApoE-/- and C57Bl/6 mice. In the ApoE-/- group, the resting membrane potential (-30.1±1.1mV) was less negative (p<0.05) compared to WT (-38.9±1.4mV) and voltage ramps generated an overall KCa current of reduced amplitude. The peak hyperpolarization to 2μM Ach was not different between the groups. However, the sustained component was significantly reduced in ApoE-/- strips. In contrast, the peak hyperpolarization to 0.2μM Ach was increased in the ApoE-/- group, and SKA-31, a direct IKCa/SKCa channel opener, produced a hyperpolarization and whole-cell current of greater amplitude. The BKCa opener NS1619 produced hyperpolarization that was enhanced in ApoE-/- group. N-arachidonoyl glycine, a BKCa opener, produced a hyperpolarization of enhanced amplitude in ApoE-/- arteries. Selective CB2 receptor agonist AM1241 (5μM) had no effect on endothelial membrane potential in WT group; however, in ApoE-/- group, it elicited hyperpolarization that was inhibited by a selective CB2 receptor antagonist AM630. Conclusively, our data point to functional down-regulation of basal IKCa activity in unstimulated endothelium of ApoE-/- mice. Direct and indirect IKCa stimulation resulted in increased recruitment of the channels. In addition, our data point to up-regulation of endothelial BKCa channels and CB2 receptors in ApoE-/- arteries.
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Affiliation(s)
- Alexander I Bondarenko
- Circulatory Physiology Department, Bogomoletz Institute of Physiology, NAS of Ukraine, Bogomoletz Str.4, 01024 Kiev, Ukraine.
| | - Olga Panasiuk
- Circulatory Physiology Department, Bogomoletz Institute of Physiology, NAS of Ukraine, Bogomoletz Str.4, 01024 Kiev, Ukraine
| | - Iryna Okhai
- Circulatory Physiology Department, Bogomoletz Institute of Physiology, NAS of Ukraine, Bogomoletz Str.4, 01024 Kiev, Ukraine
| | - Fabrizio Montecucco
- First Clinic of Internal Medicine, Department of Internal Medicine, University of Genoa, 6 viale Benedetto XV, 16132 Genoa, Italy; Ospedale Policlinico San Martino, largo Benzi 10, 16132 Genoa, Italy; Centre of Excellence for Biomedical Research (CEBR), University of Genoa, 9 viale Benedetto XV, 16132 Genoa, Italy
| | - Karim J Brandt
- Division of Cardiology, Foundation for Medical Researches, Department of Internal Medicine, University of Geneva, Av. de la Roseraie 64, CH -1211 Geneva, 4, Switzerland
| | - François Mach
- Division of Cardiology, Foundation for Medical Researches, Department of Internal Medicine, University of Geneva, Av. de la Roseraie 64, CH -1211 Geneva, 4, Switzerland
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8
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Lemmey HAL, Ye X, Ding HC, Triggle CR, Garland CJ, Dora KA. Hyperglycaemia disrupts conducted vasodilation in the resistance vasculature of db/db mice. Vascul Pharmacol 2018; 103-105:29-35. [PMID: 29339138 PMCID: PMC5906692 DOI: 10.1016/j.vph.2018.01.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2017] [Revised: 11/27/2017] [Accepted: 01/10/2018] [Indexed: 11/17/2022]
Abstract
Vascular dysfunction in small resistance arteries is observed during chronic elevations in blood glucose. Hyperglycaemia-associated effects on endothelium-dependent vasodilation have been well characterized, but effects on conducted vasodilation in the resistance vasculature are not known. Small mesenteric arteries were isolated from healthy and diabetic db/db mice, which were used as a model of chronic hyperglycaemia. Endothelium-dependent vasodilation via the Gq/11-coupled proteinase activated receptor 2 (PAR2) was stimulated with the selective agonist SLIGRL. The Ca2+-sensitive fluorescent indicator fluo-8 reported changes in endothelial cell (EC) [Ca2+]i, and triple cannulated bifurcating mesenteric arteries were used to study conducted vasodilation. Chronic hyperglycaemia did not affect either EC Ca2+ or local vasodilation to SLIGRL. However, both acute and chronic exposure to high glucose or the mannitol osmotic control attenuated conducted vasodilation to 10μM SLIGRL. This investigation demonstrates for the first time that a hypertonic solution containing glucose or mannitol can interfere with the spread of a hyperpolarizing current along the endothelium in a physiological setting. Our findings reiterate the importance of studying the effects of hyperglycaemia in the vasculature, and provide the basis for further studies regarding the modulation of junctional proteins involved in cell to cell communication by diseases such as diabetes.
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Affiliation(s)
- Hamish A L Lemmey
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, UK.
| | - Xi Ye
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, UK.
| | - Hong C Ding
- Department of Pharmacology, Weill Cornell Medicine in Qatar, P.O. Box 24144, Education City, Doha, Qatar.
| | - Christopher R Triggle
- Department of Pharmacology, Weill Cornell Medicine in Qatar, P.O. Box 24144, Education City, Doha, Qatar.
| | - Christopher J Garland
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, UK.
| | - Kim A Dora
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, UK.
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Sfyri P, Matsakas A. Crossroads between peripheral atherosclerosis, western-type diet and skeletal muscle pathophysiology: emphasis on apolipoprotein E deficiency and peripheral arterial disease. J Biomed Sci 2017; 24:42. [PMID: 28688452 PMCID: PMC5502081 DOI: 10.1186/s12929-017-0346-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 06/07/2017] [Indexed: 12/16/2022] Open
Abstract
Atherosclerosis is a chronic inflammatory process that, in the presence of hyperlipidaemia, promotes the formation of atheromatous plaques in large vessels of the cardiovascular system. It also affects peripheral arteries with major implications for a number of other non-vascular tissues such as the skeletal muscle, the liver and the kidney. The aim of this review is to critically discuss and assimilate current knowledge on the impact of peripheral atherosclerosis and its implications on skeletal muscle homeostasis. Accumulating data suggests that manifestations of peripheral atherosclerosis in skeletal muscle originates in a combination of increased i)-oxidative stress, ii)-inflammation, iii)-mitochondrial deficits, iv)-altered myofibre morphology and fibrosis, v)-chronic ischemia followed by impaired oxygen supply, vi)-reduced capillary density, vii)- proteolysis and viii)-apoptosis. These structural, biochemical and pathophysiological alterations impact on skeletal muscle metabolic and physiologic homeostasis and its capacity to generate force, which further affects the individual's quality of life. Particular emphasis is given on two major areas representing basic and applied science respectively: a)-the abundant evidence from a well-recognised atherogenic model; the Apolipoprotein E deficient mouse and the role of a western-type diet and b)-on skeletal myopathy and oxidative stress-induced myofibre damage from human studies on peripheral arterial disease. A significant source of reactive oxygen species production and oxidative stress in cardiovascular disease is the family of NADPH oxidases that contribute to several pathologies. Finally, strategies targeting NADPH oxidases in skeletal muscle in an attempt to attenuate cellular oxidative stress are highlighted, providing a better understanding of the crossroads between peripheral atherosclerosis and skeletal muscle pathophysiology.
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Affiliation(s)
- Peggy Sfyri
- Molecular Physiology Laboratory, Centre for Atherothrombotic & Metabolic Disease, Hull York Medical School, University of Hull, Cottingham Road, Hull, HU6 7RX, United Kingdom
| | - Antonios Matsakas
- Molecular Physiology Laboratory, Centre for Atherothrombotic & Metabolic Disease, Hull York Medical School, University of Hull, Cottingham Road, Hull, HU6 7RX, United Kingdom.
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10
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Tykocki NR, Boerman EM, Jackson WF. Smooth Muscle Ion Channels and Regulation of Vascular Tone in Resistance Arteries and Arterioles. Compr Physiol 2017; 7:485-581. [PMID: 28333380 DOI: 10.1002/cphy.c160011] [Citation(s) in RCA: 212] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Vascular tone of resistance arteries and arterioles determines peripheral vascular resistance, contributing to the regulation of blood pressure and blood flow to, and within the body's tissues and organs. Ion channels in the plasma membrane and endoplasmic reticulum of vascular smooth muscle cells (SMCs) in these blood vessels importantly contribute to the regulation of intracellular Ca2+ concentration, the primary determinant of SMC contractile activity and vascular tone. Ion channels provide the main source of activator Ca2+ that determines vascular tone, and strongly contribute to setting and regulating membrane potential, which, in turn, regulates the open-state-probability of voltage gated Ca2+ channels (VGCCs), the primary source of Ca2+ in resistance artery and arteriolar SMCs. Ion channel function is also modulated by vasoconstrictors and vasodilators, contributing to all aspects of the regulation of vascular tone. This review will focus on the physiology of VGCCs, voltage-gated K+ (KV) channels, large-conductance Ca2+-activated K+ (BKCa) channels, strong-inward-rectifier K+ (KIR) channels, ATP-sensitive K+ (KATP) channels, ryanodine receptors (RyRs), inositol 1,4,5-trisphosphate receptors (IP3Rs), and a variety of transient receptor potential (TRP) channels that contribute to pressure-induced myogenic tone in resistance arteries and arterioles, the modulation of the function of these ion channels by vasoconstrictors and vasodilators, their role in the functional regulation of tissue blood flow and their dysfunction in diseases such as hypertension, obesity, and diabetes. © 2017 American Physiological Society. Compr Physiol 7:485-581, 2017.
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Affiliation(s)
- Nathan R Tykocki
- Department of Pharmacology, University of Vermont, Burlington, Vermont, USA
| | - Erika M Boerman
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri, USA
| | - William F Jackson
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Michigan, USA
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11
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Dora KA. Conducted dilatation to ATP and K + in rat skeletal muscle arterioles. Acta Physiol (Oxf) 2017; 219:202-218. [PMID: 26804547 PMCID: PMC5215486 DOI: 10.1111/apha.12656] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Revised: 11/25/2015] [Accepted: 01/19/2016] [Indexed: 11/28/2022]
Abstract
AIM During exercise in humans, circulating levels of ATP and K+ increase at a time when blood flow increases to satisfy metabolic demand. Both molecules can activate arteriolar K+ channels to stimulate vasodilatation; here, it is established whether conducted dilatation is observed in a skeletal muscle bed. METHODS Isolated and cannulated rat cremaster arterioles were used to assess both local and conducted responses. Agents were either added to the bath, focally pulse-ejected to the downstream end of arterioles, or in triple-cannulated arterioles, luminally perfused into the downstream branches to assess both local and conducted responses. RESULTS The endothelium-dependent agonist ACh and the KATP channel opener levcromakalim each stimulated both local and conducted vasodilatation. Focal, bolus delivery of ATP (10 μm) or KCl (33 mm) to the outside of arterioles stimulated a biphasic vasomotor response: rapid vasoconstriction followed by dilatation as each washed away. At lower concentrations of KCl (19 mm), constriction was avoided, and instead, Ba2+ -sensitive local dilatation and conducted dilatation were both observed. Luminal perfusion of ATP avoided constriction and activated P2Y1 receptors stimulating vasodilatation secondary to opening of KCa channels. In triple-cannulated arterioles, either ATP (10 μm) or K+ (15 mm) luminally perfused into daughter branches of a bifurcation stimulated local dilatation which conducted into the parent arteriole. CONCLUSION The recognized physiological autocrine and paracrine mediators ATP and K+ each act to evoke both local and conducted vasodilatation in rat cremaster arterioles. Therefore, in situations when circulating levels are raised, such as during exercise, these agents can act as important regulators of blood flow.
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Affiliation(s)
- K. A. Dora
- Department of PharmacologyUniversity of OxfordOxfordUK
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12
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Perez-Ternero C, Rodriguez-Rodriguez R, Herrera MD, Alvarez de Sotomayor M. Diet supplementation with rice bran enzymatic extract restores endothelial impairment and wall remodelling of ApoE−/− mice microvessels. Atherosclerosis 2016; 250:15-22. [DOI: 10.1016/j.atherosclerosis.2016.04.023] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Revised: 04/26/2016] [Accepted: 04/26/2016] [Indexed: 01/19/2023]
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Schmidt K, Windler R, de Wit C. Communication Through Gap Junctions in the Endothelium. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2016; 77:209-40. [PMID: 27451099 DOI: 10.1016/bs.apha.2016.04.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
A swarm of fish displays a collective behavior (swarm behavior) and moves "en masse" despite the huge number of individual animals. In analogy, organ function is supported by a huge number of cells that act in an orchestrated fashion and this applies also to vascular cells along the vessel length. It is obvious that communication is required to achieve this vital goal. Gap junctions with their modular bricks, connexins (Cxs), provide channels that interlink the cytosol of adjacent cells by a pore sealed against the extracellular space. This allows the transfer of ions and charge and thereby the travel of membrane potential changes along the vascular wall. The endothelium provides a low-resistance pathway that depends crucially on connexin40 which is required for long-distance conduction of dilator signals in the microcirculation. The experimental evidence for membrane potential changes synchronizing vascular behavior is manifold but the functional verification of a physiologic role is still open. Other molecules may also be exchanged that possibly contribute to the synchronization (eg, Ca(2+)). Recent data suggest that vascular Cxs have more functions than just facilitating communication. As pharmacological tools to modulate gap junctions are lacking, Cx-deficient mice provide currently the standard to unravel their vascular functions. These include arteriolar dilation during functional hyperemia, hypoxic pulmonary vasoconstriction, vascular collateralization after ischemia, and feedback inhibition on renin secretion in the kidney.
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Affiliation(s)
- K Schmidt
- Institut für Physiologie, Universität zu Lübeck, Lübeck, Germany; Deutsches Zentrum für Herz-Kreislauf-Forschung (DZHK) e.V. (German Center for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, Lübeck, Germany
| | - R Windler
- Institut für Physiologie, Universität zu Lübeck, Lübeck, Germany; Deutsches Zentrum für Herz-Kreislauf-Forschung (DZHK) e.V. (German Center for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, Lübeck, Germany
| | - C de Wit
- Institut für Physiologie, Universität zu Lübeck, Lübeck, Germany; Deutsches Zentrum für Herz-Kreislauf-Forschung (DZHK) e.V. (German Center for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, Lübeck, Germany.
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Romero M, Leon-Gomez E, Lobysheva I, Rath G, Dogné JM, Feron O, Dessy C. Effects of BM-573 on Endothelial Dependent Relaxation and Increased Blood Pressure at Early Stages of Atherosclerosis. PLoS One 2016; 11:e0152579. [PMID: 27019366 PMCID: PMC4809599 DOI: 10.1371/journal.pone.0152579] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 03/16/2016] [Indexed: 12/19/2022] Open
Abstract
Endothelial dysfunction is considered to be an early event in atherosclerosis and plays a pivotal role in the development, progression and clinical complications of atherosclerosis. Previous studies have shown the beneficial effects of combined inhibition of thromboxane synthase and antagonism of thromboxane receptors by BM-573 on atherosclerosis; however our knowledge about the beneficial effects of BM-573 on endothelial function and increased blood pressure related to early stage of atherosclerosis is limited. In the present study, we investigated the effects of short-term (3 μM, 1 hour) and chronic (10 mg/L, 8 weeks) treatments with BM-573 on vasodilatory function, nitric oxide (NO) bioavailability, oxidative stress and systolic blood pressure in 15 weeks old apolipoprotein E-deficient (ApoE-KO) mice. ApoE-KO mice showed a reduced endothelium-derived relaxation. In addition, NO bioavailability was reduced and oxidative stress and blood pressure were increased in ApoE-KO mice versus wild-type mice. BM-573 treatments were able to improve the relaxation profile in ApoE-KO mice. Short-term effects of BM-573 were mainly mediated by an increased phosphorylation of both eNOS and Akt, whereas BM-573 in vivo treatment also reduced oxidative stress and restored NO bioavailability. In addition, chronic administration of BM-573 reduced systolic blood pressure in ApoE-KO mice. In conclusion, pharmacological modulation of TxA2 biosynthesis and biological activities by dual TP antagonism/TxAS inhibition with BM-573, already known to prevent plaque formation, has the potential to correct vasodilatory dysfunction at the early stages of atherosclerosis.
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Affiliation(s)
- Miguel Romero
- Pole of Pharmacology and Therapeutics (FATH), Institute of Experimental & Clinical Research (IREC), Université Catholique de Louvain (UCL) Medical School, Brussels, Belgium
- * E-mail: (MR); (CD)
| | - Elvira Leon-Gomez
- Pole of Pharmacology and Therapeutics (FATH), Institute of Experimental & Clinical Research (IREC), Université Catholique de Louvain (UCL) Medical School, Brussels, Belgium
| | - Irina Lobysheva
- Pole of Pharmacology and Therapeutics (FATH), Institute of Experimental & Clinical Research (IREC), Université Catholique de Louvain (UCL) Medical School, Brussels, Belgium
| | - Géraldine Rath
- Pole of Pharmacology and Therapeutics (FATH), Institute of Experimental & Clinical Research (IREC), Université Catholique de Louvain (UCL) Medical School, Brussels, Belgium
| | | | - Olivier Feron
- Pole of Pharmacology and Therapeutics (FATH), Institute of Experimental & Clinical Research (IREC), Université Catholique de Louvain (UCL) Medical School, Brussels, Belgium
| | - Chantal Dessy
- Pole of Pharmacology and Therapeutics (FATH), Institute of Experimental & Clinical Research (IREC), Université Catholique de Louvain (UCL) Medical School, Brussels, Belgium
- * E-mail: (MR); (CD)
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15
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Structural, mechanical and myogenic properties of small mesenteric arteries from ApoE KO mice: Characterization and effects of virgin olive oil diets. Atherosclerosis 2015; 238:55-63. [DOI: 10.1016/j.atherosclerosis.2014.11.022] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Revised: 10/18/2014] [Accepted: 11/18/2014] [Indexed: 01/19/2023]
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Ewart MA, Kennedy S, Macmillan D, Raja ALN, Watt IM, Currie S. Altered vascular smooth muscle function in the ApoE knockout mouse during the progression of atherosclerosis. Atherosclerosis 2014; 234:154-61. [PMID: 24657385 PMCID: PMC3997800 DOI: 10.1016/j.atherosclerosis.2014.02.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Revised: 01/29/2014] [Accepted: 02/18/2014] [Indexed: 02/07/2023]
Abstract
Objectives Relaxation of vascular smooth muscle (VSM) requires re-uptake of cytosolic Ca2+ into the sarcoplasmic reticulum (SR) via the Sarco/Endoplasmic Reticulum Ca2+ ATPase (SERCA), or extrusion via the Plasma Membrane Ca2+ ATPase (PMCA) or sodium Ca2+ exchanger (NCX). Peroxynitrite, a reactive species formed in vascular inflammatory diseases, upregulates SERCA activity to induce relaxation but, chronically, can contribute to atherogenesis and altered vascular function by escalating endoplasmic reticulum stress. Our objectives were to determine if peroxynitrite-induced relaxation and Ca2+ handling processes within vascular smooth muscle cells were altered as atherosclerosis develops. Methods Aortae from control and ApoE−/− mice were studied histologically, functionally and for protein expression levels of SERCA and PMCA. Ca2+ responses were assessed in dissociated aortic smooth muscle cells in the presence and absence of extracellular Ca2+. Results Relaxation to peroxynitrite was concentration-dependent and endothelium-independent. The abilities of the SERCA blocker thapsigargin and the PMCA inhibitor carboxyeosin to block this relaxation were altered during fat feeding and plaque progression. SERCA levels were progressively reduced, while PMCA expression was upregulated. In ApoE−/− VSM cells, increases in cytosolic Ca2+ [Ca2+]c in response to SERCA blockade were reduced, while SERCA-independent Ca2+ clearance was faster compared to control. Conclusion As atherosclerosis develops in the ApoE−/− mouse, expression and function of Ca2+ handling proteins are altered. Up-regulation of Ca2+ removal via PMCA may offer a potential compensatory mechanism to help normalise the dysfunctional relaxation observed during disease progression. Expression and function of SERCA and PMCA are temporally altered in ApoE−/− VSM. TG-induced increases in [Ca2+]c were reduced in ApoE−/− aortic SM cells. Ca2+ extrusion is upregulated in isolated ApoE−/− aortic SM cells.
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Affiliation(s)
- Marie-Ann Ewart
- Institute of Cardiovascular & Medical Sciences, University of Glasgow, G12 8QQ, UK.
| | - Simon Kennedy
- Institute of Cardiovascular & Medical Sciences, University of Glasgow, G12 8QQ, UK
| | - Debbi Macmillan
- Strathclyde Institute of Pharmacy & Biomedical Sciences, University of Strathclyde, Glasgow G4 0NR, UK
| | - Abhirami L N Raja
- Institute of Cardiovascular & Medical Sciences, University of Glasgow, G12 8QQ, UK
| | - Ian M Watt
- Institute of Cardiovascular & Medical Sciences, University of Glasgow, G12 8QQ, UK
| | - Susan Currie
- Strathclyde Institute of Pharmacy & Biomedical Sciences, University of Strathclyde, Glasgow G4 0NR, UK
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Mian MOR, Idris-Khodja N, Li MW, Leibowitz A, Paradis P, Rautureau Y, Schiffrin EL. Preservation of endothelium-dependent relaxation in atherosclerotic mice with endothelium-restricted endothelin-1 overexpression. J Pharmacol Exp Ther 2013; 347:30-7. [PMID: 23902937 DOI: 10.1124/jpet.113.206532] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
In human atherosclerosis, which is associated with elevated plasma and coronary endothelin (ET)-1 levels, ETA receptor antagonists improve coronary endothelial function. Mice overexpressing ET-1 specifically in the endothelium (eET-1) crossed with atherosclerosis-prone apolipoprotein E knockout mice (Apoe(-/-)) exhibit exaggerated high-fat diet (HFD)-induced atherosclerosis. Since endothelial dysfunction often precedes atherosclerosis development, we hypothesized that mice overexpressing endothelial ET-1 on a genetic background deficient in apolipoprotein E (eET-1/Apoe(-/-)) would have severe endothelial dysfunction. To test this hypothesis, we investigated endothelium-dependent relaxation (EDR) to acetylcholine in eET-1/Apoe(-/-) mice. EDR in mesenteric resistance arteries from 8- and 16-week-old mice fed a normal diet or HFD was improved in eET-1/Apoe(-/-) compared with Apoe(-/-) mice. Nitric oxide synthase (NOS) inhibition abolished EDR in Apoe(-/-). EDR in eET-1/Apoe(-/-) mice was resistant to NOS inhibition irrespective of age or diet. Inhibition of cyclooxygenase, the cytochrome P450 pathway, and endothelium-dependent hyperpolarization (EDH) resulted in little or no inhibition of EDR in eET-1/Apoe(-/-) compared with wild-type (WT) mice. In eET-1/Apoe(-/-) mice, blocking of EDH or soluble guanylate cyclase (sGC), in addition to NOS inhibition, decreased EDR by 36 and 30%, respectively. The activation of 4-aminopyridine-sensitive voltage-dependent potassium channels (Kv) during EDR was increased in eET-1/Apoe(-/-) compared with WT mice. We conclude that increasing eET-1 in mice that develop atherosclerosis results in decreased mutual dependence of endothelial signaling pathways responsible for EDR, and that NOS-independent activation of sGC and increased activation of Kv are responsible for enhanced EDR in this model of atherosclerosis associated with elevated endothelial and circulating ET-1.
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Affiliation(s)
- Muhammad Oneeb Rehman Mian
- Lady Davis Institute for Medical Research (M.O.R.M., N.I.-K., M.W.L., A.L., P.P., Y.R., E.L.S.), and Department of Medicine (E.L.S.), Sir Mortimer B. Davis-Jewish General Hospital, McGill University, Montréal, Québec, Canada
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Billaud M, Lohman AW, Straub AC, Parpaite T, Johnstone SR, Isakson BE. Characterization of the thoracodorsal artery: morphology and reactivity. Microcirculation 2012; 19:360-72. [PMID: 22335567 DOI: 10.1111/j.1549-8719.2012.00172.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
OBJECTIVES In this paper, we describe the histological and contractile properties of the thoracodorsal artery (TDA), which indirectly feeds the spinotrapezius muscle. METHODS We used immunolabelling techniques to histologically characterize the TDA while the contractile properties were assessed using pressure arteriography. RESULTS Our results demonstrate that the TDA is composed of approximately one to two layers of smooth muscle cells, is highly innervated with adrenergic nerves, and develops spontaneous tone at intraluminal pressures above 80 mmHg. The reactivity of the TDA in response to various contractile agonists such as phenylephrine, noradrenaline, angiotensin II, serotonin, endothelin 1, and ATP, as well as vasodilators, shows that the TDA exhibits a remarkably comparable reactivity to what has been observed in mesenteric arteries. We further studied the different components of the TDA response to acetylcholine, and found that the TDA was sensitive to TRAM 34, a blocker of the intermediate conductance potassium channel, which is highly suggestive of an endothelium-dependent hyperpolarization. CONCLUSIONS We conclude that the TDA exhibits comparable characteristics to other current vascular models, with the additional advantage of being easily manipulated for molecular and ex vivo vasoreactivity studies.
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Affiliation(s)
- Marie Billaud
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, Virginia 22908, USA
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Senadheera S, Kim Y, Grayson TH, Toemoe S, Kochukov MY, Abramowitz J, Housley GD, Bertrand RL, Chadha PS, Bertrand PP, Murphy TV, Tare M, Birnbaumer L, Marrelli SP, Sandow SL. Transient receptor potential canonical type 3 channels facilitate endothelium-derived hyperpolarization-mediated resistance artery vasodilator activity. Cardiovasc Res 2012; 95:439-47. [PMID: 22721989 DOI: 10.1093/cvr/cvs208] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
AIMS Microdomain signalling mechanisms underlie key aspects of artery function and the modulation of intracellular calcium, with transient receptor potential (TRP) channels playing an integral role. This study determines the distribution and role of TRP canonical type 3 (C3) channels in the control of endothelium-derived hyperpolarization (EDH)-mediated vasodilator tone in rat mesenteric artery. METHODS AND RESULTS TRPC3 antibody specificity was verified using rat tissue, human embryonic kidney (HEK)-293 cells stably transfected with mouse TRPC3 cDNA, and TRPC3 knock-out (KO) mouse tissue using western blotting and confocal and ultrastructural immunohistochemistry. TRPC3-Pyr3 (ethyl-1-(4-(2,3,3-trichloroacrylamide)phenyl)-5-(trifluoromethyl)-1H-pyrazole-4-carboxylate) specificity was verified using patch clamp of mouse mesenteric artery endothelial and TRPC3-transfected HEK cells, and TRPC3 KO and wild-type mouse aortic endothelial cell calcium imaging and mesenteric artery pressure myography. TRPC3 distribution, expression, and role in EDH-mediated function were examined in rat mesenteric artery using immunohistochemistry and western blotting, and pressure myography and endothelial cell membrane potential recordings. In rat mesenteric artery, TRPC3 was diffusely distributed in the endothelium, with approximately five-fold higher expression at potential myoendothelial microdomain contact sites, and immunoelectron microscopy confirmed TRPC3 at these sites. Western blotting and endothelial damage confirmed primary endothelial TRPC3 expression. In rat mesenteric artery endothelial cells, Pyr3 inhibited hyperpolarization generation, and with individual SK(Ca) (apamin) or IK(Ca) (TRAM-34) block, Pyr3 abolished the residual respective IK(Ca)- and SK(Ca)-dependent EDH-mediated vasodilation. CONCLUSION The spatial localization of TRPC3 and associated channels, receptors, and calcium stores are integral for myoendothelial microdomain function. TRPC3 facilitates endothelial SK(Ca) and IK(Ca) activation, as key components of EDH-mediated vasodilator activity and for regulating mesenteric artery tone.
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Affiliation(s)
- Sevvandi Senadheera
- Department of Physiology, School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney 2052, Australia.
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Triggle CR, Samuel SM, Ravishankar S, Marei I, Arunachalam G, Ding H. The endothelium: influencing vascular smooth muscle in many ways. Can J Physiol Pharmacol 2012; 90:713-38. [PMID: 22625870 DOI: 10.1139/y2012-073] [Citation(s) in RCA: 157] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The endothelium, although only a single layer of cells lining the vascular and lymphatic systems, contributes in multiple ways to vascular homeostasis. Subsequent to the 1980 report by Robert Furchgott and John Zawadzki, there has been a phenomenal increase in our knowledge concerning the signalling molecules and pathways that regulate endothelial - vascular smooth muscle communication. It is now recognised that the endothelium is not only an important source of nitric oxide (NO), but also numerous other signalling molecules, including the putative endothelium-derived hyperpolarizing factor (EDHF), prostacyclin (PGI(2)), and hydrogen peroxide (H(2)O(2)), which have both vasodilator and vasoconstrictor properties. In addition, the endothelium, either via transferred chemical mediators, such as NO and PGI(2), and (or) low-resistance electrical coupling through myoendothelial gap junctions, modulates flow-mediated vasodilatation as well as influencing mitogenic activity, platelet aggregation, and neutrophil adhesion. Disruption of endothelial function is an early indicator of the development of vascular disease, and thus an important area for further research and identification of potentially new therapeutic targets. This review focuses on the signalling pathways that regulate endothelial - vascular smooth muscle communication and the mechanisms that initiate endothelial dysfunction, particularly with respect to diabetic vascular disease.
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Affiliation(s)
- Chris R Triggle
- Department of Pharmacology, Weill Cornell Medical College in Qatar, P.O. Box 24144, Education City, Doha, Qatar.
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Jackson WF. Standing out in a crowd: knockout of ApoE increases the potency of endothelium-dependent vasodilators in mesenteric arteries. Cardiovasc Res 2011; 92:183-4. [DOI: 10.1093/cvr/cvr253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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