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DuToit J, Brothers P, Stephens M, Keane K, de Jesus FN, Roizes S, von der Weid PY. Flow-dependent regulation of rat mesenteric lymphatic vessel contractile response requires activation of endothelial TRPV4 channels. Microcirculation 2024; 31:e12839. [PMID: 38044795 DOI: 10.1111/micc.12839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 11/06/2023] [Accepted: 11/22/2023] [Indexed: 12/05/2023]
Abstract
OBJECTIVES The objective of our study is to evaluate the involvement of the transient receptor potential vanilloid 4 (TRPV4) in the alteration of lymphatic pumping in response to flow and determine the signaling pathways involved. METHODS We used immunofluorescence imaging and western blotting to assess TRPV4 expression in rat mesenteric lymphatic vessels. We examined inhibition of TRPV4 with HC067047, nitric oxide synthase (NOS) with L-NNA and cyclooxygenases (COXs) with indomethacin on the contractile response of pressurized lymphatic vessels to flow changes induced by a stepwise increase in pressure gradients, and the functionality of endothelial TRPV4 channels by measuring the intracellular Ca2+ response of primary lymphatic endothelial cell cultures to the selective agonist GSK1016790A. RESULTS TRPV4 protein was expressed in both the endothelial and the smooth muscle layer of rat mesenteric lymphatics with high endothelial expression around the valve sites. When maintained under constant transmural pressure, most lymphatic vessels displayed a decrease in contraction frequency under conditions of flow and this effect was ablated through inhibition of NOS, COX or TRPV4. CONCLUSIONS Our findings demonstrate a critical role for TRPV4 in the decrease in contraction frequency induced in lymphatic vessels by increases in flow rate via the production and action of nitric oxide and dilatory prostanoids.
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Affiliation(s)
- Jacques DuToit
- Inflammation Research Network, Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, Department of Physiology & Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Peter Brothers
- Inflammation Research Network, Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, Department of Physiology & Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Matthew Stephens
- Inflammation Research Network, Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, Department of Physiology & Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Keith Keane
- Inflammation Research Network, Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, Department of Physiology & Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Flavia Neto de Jesus
- Inflammation Research Network, Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, Department of Physiology & Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Simon Roizes
- Inflammation Research Network, Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, Department of Physiology & Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Pierre-Yves von der Weid
- Inflammation Research Network, Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, Department of Physiology & Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
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2
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Edwards-Glenn JM, Fontes MT, Waigi EW, Costa TJ, Maiseyeu A, Webb RC, McCarthy CG, Wenceslau CF. Specialized Pro-resolving Mediator Improves Vascular Relaxation via Formyl Peptide Receptor-2. Am J Hypertens 2023; 36:542-550. [PMID: 37439351 PMCID: PMC10502783 DOI: 10.1093/ajh/hpad062] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 06/29/2023] [Accepted: 07/11/2023] [Indexed: 07/14/2023] Open
Abstract
BACKGROUND The resolution of inflammation is an active phenomenon important for switching off inflammatory processes once the harmful stimuli are removed and facilitate the return to homeostasis. Specialized pro-resolving mediators (SPMs), such as lipoxin A4, resolvin D1, and resolvin E1, derived from ω-3 or ω-6 polyunsaturated fatty acids, are crucial for the resolution of inflammation. We hypothesized that SPMs are decreased in hypertension which contributes to the acetylcholine-induced contraction in resistance arteries, which are well known to be mediated by leukotrienes and prostaglandins. Moreover, treatment with SPMs will decrease this contraction via formyl peptide receptor-2 (FPR-2) in resistance arteries from spontaneously hypertensive rats (SHR). METHODS AND RESULTS We performed a comprehensive eicosanoid lipid panel analysis, and our data showed for the first time that precursors of SPMs are decreased in SHR, limiting the production of SPMs and resolution of inflammation in vivo. This phenomenon was associated with an increase in lipid peroxidation in resistance arteries. Although SPMs did not abolish acetylcholine-induced contraction, these lipid mediators improved endothelial function in arteries from SHR via FPR-2 activation at nanomolar concentrations. SPMs also buffered TNF-α-induced reactive oxygen species generation in endothelial cells from C57Bl/6 mice. CONCLUSIONS We suggest that FPR-2 and SPMs could be revealed as a new target or therapeutic agent to improve vascular function in arteries from hypertensive rats.
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Affiliation(s)
- Jonnelle M Edwards-Glenn
- Cardiovascular Research Institute, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
| | - Milene T Fontes
- Cardiovascular Translational Research Center, Department of Cell Biology and Anatomy, University of South Carolina School of Medicine, Columbia, South Carolina, USA
| | - Emily W Waigi
- Cardiovascular Translational Research Center, Department of Cell Biology and Anatomy, University of South Carolina School of Medicine, Columbia, South Carolina, USA
| | - Tiago J Costa
- Cardiovascular Translational Research Center, Department of Cell Biology and Anatomy, University of South Carolina School of Medicine, Columbia, South Carolina, USA
| | - Andrei Maiseyeu
- Cardiovascular Research Institute, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
| | - R Clinton Webb
- Cardiovascular Translational Research Center, Department of Cell Biology and Anatomy, University of South Carolina School of Medicine, Columbia, South Carolina, USA
- Biomedical Engineering Program, College of Engineering and Computing, University of South Carolina, Columbia, South Carolina, USA
| | - Cameron G McCarthy
- Cardiovascular Translational Research Center, Department of Cell Biology and Anatomy, University of South Carolina School of Medicine, Columbia, South Carolina, USA
- Biomedical Engineering Program, College of Engineering and Computing, University of South Carolina, Columbia, South Carolina, USA
| | - Camilla F Wenceslau
- Cardiovascular Translational Research Center, Department of Cell Biology and Anatomy, University of South Carolina School of Medicine, Columbia, South Carolina, USA
- Biomedical Engineering Program, College of Engineering and Computing, University of South Carolina, Columbia, South Carolina, USA
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3
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The spectrin cytoskeleton integrates endothelial mechanoresponses. Nat Cell Biol 2022; 24:1226-1238. [PMID: 35817960 DOI: 10.1038/s41556-022-00953-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 06/01/2022] [Indexed: 12/13/2022]
Abstract
Physiological blood flow induces the secretion of vasoactive compounds, notably nitric oxide, and promotes endothelial cell elongation and reorientation parallel to the direction of applied shear. How shear is sensed and relayed to intracellular effectors is incompletely understood. Here, we demonstrate that an apical spectrin network is essential to convey the force imposed by shear to endothelial mechanosensors. By anchoring CD44, spectrins modulate the cell surface density of hyaluronan and sense and translate shear into changes in plasma membrane tension. Spectrins also regulate the stability of apical caveolae, where the mechanosensitive PIEZO1 channels are thought to reside. Accordingly, shear-induced PIEZO1 activation and the associated calcium influx were absent in spectrin-deficient cells. As a result, cell realignment and flow-induced endothelial nitric oxide synthase stimulation were similarly dependent on spectrin. We conclude that the apical spectrin network is not only required for shear sensing but also transmits and distributes the resulting tensile forces to mechanosensors that elicit protective and vasoactive responses.
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Edwards JM, McCarthy CG, Wenceslau CF. The Obligatory Role of the Acetylcholine-Induced Endothelium-Dependent Contraction in Hypertension: Can Arachidonic Acid Resolve this Inflammation? Curr Pharm Des 2021; 26:3723-3732. [PMID: 32303165 DOI: 10.2174/1381612826666200417150121] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Accepted: 04/10/2020] [Indexed: 02/07/2023]
Abstract
The endothelium produces many substances that can regulate vascular tone. Acetylcholine is a widely used pharmacological tool to assess endothelial function. In general, acetylcholine binds to G-protein coupled muscarinic receptors that mediate a transient elevation in intracellular, free calcium. This intracellular rise in calcium is responsible for triggering several cellular responses, including the synthesis of nitric oxide, endothelium- derived hyperpolarizing factor, and eicosanoids derived from arachidonic acid. Endothelial arachidonic acid metabolism is also an important signaling pathway for mediating inflammation. Therefore, in conditions with sustained and excessive inflammation such as hypertension, arachidonic acid serves as a substrate for the synthesis of several vasoconstrictive metabolites, predominantly via the cyclooxygenase and lipoxygenase enzymes. Cyclooxygenase and lipoxygenase products can then activate G-protein coupled receptors expressed on vascular smooth muscle cells to causes contractile responses. As a result, acetylcholine-induced contraction due to arachidonic acid is a commonly observed feature of endothelial dysfunction and vascular inflammation in hypertension. In this review, we will critically analyze the literature supporting this concept, as well as address the potential underlying mechanisms, including the possibility that arachidonic acid signaling is diverted away from the synthesis of pro-resolving metabolites in conditions such as hypertension.
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Affiliation(s)
- Jonnelle M Edwards
- Center for Hypertension and Precision Medicine, Department of Physiology and Pharmacology, University of Toledo College of Medicine & Life Sciences, Toledo, OH, United States
| | - Cameron G McCarthy
- Center for Hypertension and Precision Medicine, Department of Physiology and Pharmacology, University of Toledo College of Medicine & Life Sciences, Toledo, OH, United States
| | - Camilla F Wenceslau
- Center for Hypertension and Precision Medicine, Department of Physiology and Pharmacology, University of Toledo College of Medicine & Life Sciences, Toledo, OH, United States
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5
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Hong KS, Lee MG. Endothelial Ca 2+ signaling-dependent vasodilation through transient receptor potential channels. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2020; 24:287-298. [PMID: 32587123 PMCID: PMC7317173 DOI: 10.4196/kjpp.2020.24.4.287] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 04/03/2020] [Accepted: 04/14/2020] [Indexed: 01/18/2023]
Abstract
Ca2+ signaling of endothelial cells plays a critical role in controlling blood flow and pressure in small arteries and arterioles. As the impairment of endothelial function is closely associated with cardiovascular diseases (e.g., atherosclerosis, stroke, and hypertension), endothelial Ca2+ signaling mechanisms have received substantial attention. Increases in endothelial intracellular Ca2+ concentrations promote the synthesis and release of endothelial-derived hyperpolarizing factors (EDHFs, e.g., nitric oxide, prostacyclin, or K+ efflux) or directly result in endothelial-dependent hyperpolarization (EDH). These physiological alterations modulate vascular contractility and cause marked vasodilation in resistance arteries. Transient receptor potential (TRP) channels are nonselective cation channels that are present in the endothelium, vascular smooth muscle cells, or perivascular/sensory nerves. TRP channels are activated by diverse stimuli and are considered key biological apparatuses for the Ca2+ influx-dependent regulation of vasomotor reactivity in resistance arteries. Ca2+-permeable TRP channels, which are primarily found at spatially restricted microdomains in endothelial cells (e.g., myoendothelial projections), have a large unitary or binary conductance and contribute to EDHFs or EDH-induced vasodilation in concert with the activation of intermediate/small conductance Ca2+-sensitive K+ channels. It is likely that endothelial TRP channel dysfunction is related to the dysregulation of endothelial Ca2+ signaling and in turn gives rise to vascular-related diseases such as hypertension. Thus, investigations on the role of Ca2+ dynamics via TRP channels in endothelial cells are required to further comprehend how vascular tone or perfusion pressure are regulated in normal and pathophysiological conditions.
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Affiliation(s)
- Kwang-Seok Hong
- Department of Physical Education, College of Education, Chung-Ang University, Seoul 06974, Korea
| | - Man-Gyoon Lee
- Sports Medicine and Science, Graduate School of Physical Education, Kyung Hee University, Yongin 17104, Korea
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6
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Lin Q, Zhao L, Jing R, Trexler C, Wang H, Li Y, Tang H, Huang F, Zhang F, Fang X, Liu J, Jia N, Chen J, Ouyang K. Inositol 1,4,5-Trisphosphate Receptors in Endothelial Cells Play an Essential Role in Vasodilation and Blood Pressure Regulation. J Am Heart Assoc 2019; 8:e011704. [PMID: 30755057 PMCID: PMC6405661 DOI: 10.1161/jaha.118.011704] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Accepted: 01/17/2019] [Indexed: 01/06/2023]
Abstract
Background Endothelial NO synthase plays a central role in regulating vasodilation and blood pressure. Intracellular Ca2+ mobilization is a critical modulator of endothelial NO synthase function, and increased cytosolic Ca2+ concentration in endothelial cells is able to induce endothelial NO synthase phosphorylation. Ca2+ release mediated by 3 subtypes of inositol 1,4,5-trisphosphate receptors ( IP 3Rs) from the endoplasmic reticulum and subsequent Ca2+ entry after endoplasmic reticulum Ca2+ store depletion has been proposed to be the major pathway to mobilize Ca2+ in endothelial cells. However, the physiological role of IP 3Rs in regulating blood pressure remains largely unclear. Methods and Results To investigate the role of endothelial IP 3Rs in blood pressure regulation, we first generated an inducible endothelial cell-specific IP 3R1 knockout mouse model and found that deletion of IP 3R1 in adult endothelial cells did not affect vasodilation and blood pressure. Considering all 3 subtypes of IP 3Rs are expressed in mouse endothelial cells, we further generated inducible endothelial cell-specific IP 3R triple knockout mice and found that deletion of all 3 IP 3R subtypes decreased plasma NO concentration and increased basal blood pressure. Furthermore, IP 3R deficiency reduced acetylcholine-induced vasodilation and endothelial NO synthase phosphorylation at Ser1177. Conclusions Our results reveal that IP 3R-mediated Ca2+ release in vascular endothelial cells plays an important role in regulating vasodilation and physiological blood pressure.
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MESH Headings
- Animals
- Aorta, Thoracic/metabolism
- Aorta, Thoracic/pathology
- Aorta, Thoracic/physiopathology
- Blood Pressure/physiology
- Calcium/metabolism
- Disease Models, Animal
- Endothelial Cells/metabolism
- Endothelial Cells/pathology
- Endothelium, Vascular/metabolism
- Endothelium, Vascular/pathology
- Endothelium, Vascular/physiopathology
- Hypertension/metabolism
- Hypertension/pathology
- Hypertension/physiopathology
- Immunoblotting
- Inositol 1,4,5-Trisphosphate Receptors/physiology
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Myography
- Vasodilation/physiology
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Affiliation(s)
- Qingsong Lin
- Drug Discovery CenterState Key Laboratory of Chemical OncogenomicsSchool of Chemical Biology and BiotechnologyPeking University Shenzhen Graduate SchoolShenzhenChina
| | - Lingyun Zhao
- Drug Discovery CenterState Key Laboratory of Chemical OncogenomicsSchool of Chemical Biology and BiotechnologyPeking University Shenzhen Graduate SchoolShenzhenChina
| | - Ran Jing
- Department of CardiologyThe Second Xiangya HospitalCentral South UniversityChangshaHunanChina
| | - Christa Trexler
- Department of MedicineSchool of MedicineUniversity of California San DiegoLa JollaCA
| | - Hong Wang
- Drug Discovery CenterState Key Laboratory of Chemical OncogenomicsSchool of Chemical Biology and BiotechnologyPeking University Shenzhen Graduate SchoolShenzhenChina
| | - Yali Li
- Drug Discovery CenterState Key Laboratory of Chemical OncogenomicsSchool of Chemical Biology and BiotechnologyPeking University Shenzhen Graduate SchoolShenzhenChina
| | - Huayuan Tang
- Drug Discovery CenterState Key Laboratory of Chemical OncogenomicsSchool of Chemical Biology and BiotechnologyPeking University Shenzhen Graduate SchoolShenzhenChina
| | - Fang Huang
- Drug Discovery CenterState Key Laboratory of Chemical OncogenomicsSchool of Chemical Biology and BiotechnologyPeking University Shenzhen Graduate SchoolShenzhenChina
| | - Fei Zhang
- Drug Discovery CenterState Key Laboratory of Chemical OncogenomicsSchool of Chemical Biology and BiotechnologyPeking University Shenzhen Graduate SchoolShenzhenChina
| | - Xi Fang
- Department of MedicineSchool of MedicineUniversity of California San DiegoLa JollaCA
| | - Jie Liu
- Department of PathophysiologySchool of MedicineShenzhen UniversityShenzhenChina
| | - Nan Jia
- Department of CardiologyThe Eighth Affiliated HospitalSun Yat‐sen UniversityShenzhenChina
| | - Ju Chen
- Department of MedicineSchool of MedicineUniversity of California San DiegoLa JollaCA
| | - Kunfu Ouyang
- Drug Discovery CenterState Key Laboratory of Chemical OncogenomicsSchool of Chemical Biology and BiotechnologyPeking University Shenzhen Graduate SchoolShenzhenChina
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7
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Gulzar M, Ali S, Khan FI, Khan P, Taneja P, Hassan MI. Binding mechanism of caffeic acid and simvastatin to the integrin linked kinase for therapeutic implications: a comparative docking and MD simulation studies. J Biomol Struct Dyn 2019; 37:4327-4337. [PMID: 30488773 DOI: 10.1080/07391102.2018.1546621] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Integrin linked kinase (ILK) is a Ser/Thr kinase, which regulates various integrin mediated signaling pathways, and is involved in cell adhesion, migration and differentiation. Alteration in the ILK is responsible for abnormal functioning of the cell system, which may lead to the cancer progression and metastasis. Caffeic acid (CA) and simvastatin are used as antioxidant and possess anticancer properties. Thus, inhibiting the kinase activity of ILK by CA and simvastatin may be implicated in the cancer therapy. In this study, we have performed molecular docking followed by 100 ns MD simulations to understand the interaction mechanism of ILK protein with the CA and simvastatin. Average potential energy was found to be highest in case of ILK-CA complex (-770,949 kJ/mol). Binding free energy was found to be higher in case of simvastatin than CA. Our results indicate that simvastatin binds more effectively to the active pocket of ILK. We further performed MTT assay to understand its anticancer potential. Simvastatin shows the IC50 values for HepG2 and MCF-7 as 19.18 ± 0.12 and 13.84 ± 0.22 µM, respectively. However, the IC50 value of CA on HepG2 and MCF-7 was reported as 175.50 ± 1.44 and 144.90 ± 1.53 µM, respectively. Our study provides a deeper insight into the binding mechanism of simvastatin and CA to ILK, which further opens a promising channel for their implications in cancer therapy.
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Affiliation(s)
- Mehak Gulzar
- Department of Biotechnology, Sharda University , Greater Noida , Uttar Pradesh, India
| | - Shahid Ali
- School of Food Science and Engineering, South China University of Technology , Guangzhou , People's Republic of China
| | - Faez Iqbal Khan
- Computational Mechanistic Chemistry and Drug Discovery, Rhodes University , Grahamstown , South Africa
| | - Parvez Khan
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia , New Delhi , India
| | - Pankaj Taneja
- Department of Biotechnology, Sharda University , Greater Noida , Uttar Pradesh, India
| | - Md Imtaiyaz Hassan
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia , New Delhi , India
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8
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Lee MD, Wilson C, Saunter CD, Kennedy C, Girkin JM, McCarron JG. Spatially structured cell populations process multiple sensory signals in parallel in intact vascular endothelium. Sci Signal 2018; 11:11/561/eaar4411. [PMID: 30563865 DOI: 10.1126/scisignal.aar4411] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Blood flow, blood clotting, angiogenesis, vascular permeability, and vascular remodeling are each controlled by a large number of variable, noisy, and interacting chemical inputs to the vascular endothelium. The endothelium processes the entirety of the chemical composition to which the cardiovascular system is exposed, carrying out sophisticated computations that determine physiological output. Processing this enormous quantity of information is a major challenge facing the endothelium. We analyzed the responses of hundreds of endothelial cells to carbachol (CCh) and adenosine triphosphate (ATP) and found that the endothelium segregates the responses to these two distinct components of the chemical environment into separate streams of complementary information that are processed in parallel. Sensitivities to CCh and ATP mapped to different clusters of cells, and each agonist generated distinct signal patterns. The distinct signals were features of agonist activation rather than properties of the cells themselves. When there was more than one stimulus present, the cells communicated and combined inputs to generate new distinct signals that were nonlinear combinations of the inputs. Our results demonstrate that the endothelium is a structured, collaborative sensory network that simplifies the complex environment using separate cell clusters that are sensitive to distinct aspects of the overall biochemical environment and interactively compute signals from diverse but interrelated chemical inputs. These features enable the endothelium to selectively process separate signals and perform multiple computations in an environment that is noisy and variable.
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Affiliation(s)
- Matthew D Lee
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, Glasgow G4 0RE, UK
| | - Calum Wilson
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, Glasgow G4 0RE, UK
| | - Christopher D Saunter
- Centre for Advanced Instrumentation, Biophysical Sciences Institute, Department of Physics, Durham University, South Road, Durham DH1 3LE, UK
| | - Charles Kennedy
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, Glasgow G4 0RE, UK
| | - John M Girkin
- Centre for Advanced Instrumentation, Biophysical Sciences Institute, Department of Physics, Durham University, South Road, Durham DH1 3LE, UK
| | - John G McCarron
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, Glasgow G4 0RE, UK.
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9
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Ghosh A, Gao L, Thakur A, Siu PM, Lai CWK. Role of free fatty acids in endothelial dysfunction. J Biomed Sci 2017; 24:50. [PMID: 28750629 PMCID: PMC5530532 DOI: 10.1186/s12929-017-0357-5] [Citation(s) in RCA: 262] [Impact Index Per Article: 37.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Accepted: 07/24/2017] [Indexed: 02/06/2023] Open
Abstract
Plasma free fatty acids levels are increased in subjects with obesity and type 2 diabetes, playing detrimental roles in the pathogenesis of atherosclerosis and cardiovascular diseases. Increasing evidence showing that dysfunction of the vascular endothelium, the inner lining of the blood vessels, is the key player in the pathogenesis of atherosclerosis. In this review, we aimed to summarize the roles and the underlying mechanisms using the evidence collected from clinical and experimental studies about free fatty acid-mediated endothelial dysfunction. Because of the multifaceted roles of plasma free fatty acids in mediating endothelial dysfunction, elevated free fatty acid level is now considered as an important link in the onset of endothelial dysfunction due to metabolic syndromes such as diabetes and obesity. Free fatty acid-mediated endothelial dysfunction involves several mechanisms including impaired insulin signaling and nitric oxide production, oxidative stress, inflammation and the activation of the renin-angiotensin system and apoptosis in the endothelial cells. Therefore, targeting the signaling pathways involved in free fatty acid-induced endothelial dysfunction could serve as a preventive approach to protect against the occurrence of endothelial dysfunction and the subsequent complications such as atherosclerosis.
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Affiliation(s)
- Arijit Ghosh
- Department of Health Technology and Informatics, The Hong Kong Polytechnic University, HKSAR, China
- Department of Biomedical Sciences, City University of Hong Kong, HKSAR, China
| | - Lei Gao
- Department of Health Technology and Informatics, The Hong Kong Polytechnic University, HKSAR, China
| | - Abhimanyu Thakur
- Department of Biomedical Sciences, City University of Hong Kong, HKSAR, China
| | - Parco M. Siu
- Department of Health Technology and Informatics, The Hong Kong Polytechnic University, HKSAR, China
| | - Christopher W. K. Lai
- Department of Health Technology and Informatics, The Hong Kong Polytechnic University, HKSAR, China
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10
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Charoensin S, Eroglu E, Opelt M, Bischof H, Madreiter-Sokolowski CT, Kirsch A, Depaoli MR, Frank S, Schrammel A, Mayer B, Waldeck-Weiermair M, Graier WF, Malli R. Intact mitochondrial Ca 2+ uniport is essential for agonist-induced activation of endothelial nitric oxide synthase (eNOS). Free Radic Biol Med 2017; 102:248-259. [PMID: 27923677 PMCID: PMC5381715 DOI: 10.1016/j.freeradbiomed.2016.11.049] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Revised: 11/14/2016] [Accepted: 11/28/2016] [Indexed: 12/18/2022]
Abstract
Mitochondrial Ca2+ uptake regulates diverse endothelial cell functions and has also been related to nitric oxide (NO•) production. However, it is not entirely clear if the organelles support or counteract NO• biosynthesis by taking up Ca2+. The objective of this study was to verify whether or not mitochondrial Ca2+ uptake influences Ca2+-triggered NO• generation by endothelial NO• synthase (eNOS) in an immortalized endothelial cell line (EA.hy926), respective primary human umbilical vein endothelial cells (HUVECs) and eNOS-RFP (red fluorescent protein) expressing human embryonic kidney (HEK293) cells. We used novel genetically encoded fluorescent NO• probes, the geNOps, and Ca2+ sensors to monitor single cell NO• and Ca2+ dynamics upon cell treatment with ATP, an inositol 1,4,5-trisphosphate (IP3)-generating agonist. Mitochondrial Ca2+ uptake was specifically manipulated by siRNA-mediated knock-down of recently identified key components of the mitochondrial Ca2+ uniporter machinery. In endothelial cells and the eNOS-RFP expressing HEK293 cells we show that reduced mitochondrial Ca2+ uptake upon the knock-down of the mitochondrial calcium uniporter (MCU) protein and the essential MCU regulator (EMRE) yield considerable attenuation of the Ca2+-triggered NO• increase independently of global cytosolic Ca2+ signals. The knock-down of mitochondrial calcium uptake 1 (MICU1), a gatekeeper of the MCU, increased both mitochondrial Ca2+ sequestration and Ca2+-induced NO• signals. The positive correlation between mitochondrial Ca2+ elevation and NO• production was independent of eNOS phosphorylation at serine1177. Our findings emphasize that manipulating mitochondrial Ca2+ uptake may represent a novel strategy to control eNOS-mediated NO• production.
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Affiliation(s)
- Suphachai Charoensin
- Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University of Graz, Austria
| | - Emrah Eroglu
- Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University of Graz, Austria
| | - Marissa Opelt
- Institute of Pharmaceutical Sciences, Department of Pharmacology and Toxicology, University of Graz, Austria
| | - Helmut Bischof
- Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University of Graz, Austria
| | | | - Andrijana Kirsch
- Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University of Graz, Austria
| | - Maria R Depaoli
- Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University of Graz, Austria
| | - Saša Frank
- Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University of Graz, Austria
| | - Astrid Schrammel
- Institute of Pharmaceutical Sciences, Department of Pharmacology and Toxicology, University of Graz, Austria
| | - Bernd Mayer
- Institute of Pharmaceutical Sciences, Department of Pharmacology and Toxicology, University of Graz, Austria
| | - Markus Waldeck-Weiermair
- Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University of Graz, Austria
| | - Wolfgang F Graier
- Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University of Graz, Austria
| | - Roland Malli
- Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University of Graz, Austria.
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11
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Affiliation(s)
- Paulo W Pires
- From the Department of Pharmacology, Center for Cardiovascular Research, University of Nevada School of Medicine, Reno
| | - Scott Earley
- From the Department of Pharmacology, Center for Cardiovascular Research, University of Nevada School of Medicine, Reno.
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12
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Eroglu E, Gottschalk B, Charoensin S, Blass S, Bischof H, Rost R, Madreiter-Sokolowski CT, Pelzmann B, Bernhart E, Sattler W, Hallström S, Malinski T, Waldeck-Weiermair M, Graier WF, Malli R. Development of novel FP-based probes for live-cell imaging of nitric oxide dynamics. Nat Commun 2016; 7:10623. [PMID: 26842907 PMCID: PMC4743004 DOI: 10.1038/ncomms10623] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 01/05/2016] [Indexed: 12/22/2022] Open
Abstract
Nitric oxide () is a free radical with a wide range of biological effects, but practically impossible to visualize in single cells. Here we report the development of novel multicoloured fluorescent quenching-based probes by fusing a bacteria-derived -binding domain close to distinct fluorescent protein variants. These genetically encoded probes, referred to as geNOps, provide a selective, specific and real-time read-out of cellular dynamics and, hence, open a new era of bioimaging. The combination of geNOps with a Ca(2+) sensor allowed us to visualize and Ca(2+) signals simultaneously in single endothelial cells. Moreover, targeting of the probes was used to detect signals within mitochondria. The geNOps are useful new tools to further investigate and understand the complex patterns of signalling on the single (sub)cellular level.
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Affiliation(s)
- Emrah Eroglu
- Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University of Graz, Harrachgasse 21/III, 8010 Graz, Austria
| | - Benjamin Gottschalk
- Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University of Graz, Harrachgasse 21/III, 8010 Graz, Austria
| | - Suphachai Charoensin
- Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University of Graz, Harrachgasse 21/III, 8010 Graz, Austria
| | - Sandra Blass
- Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University of Graz, Harrachgasse 21/III, 8010 Graz, Austria
| | - Helmut Bischof
- Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University of Graz, Harrachgasse 21/III, 8010 Graz, Austria
| | - Rene Rost
- Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University of Graz, Harrachgasse 21/III, 8010 Graz, Austria
| | - Corina T Madreiter-Sokolowski
- Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University of Graz, Harrachgasse 21/III, 8010 Graz, Austria
| | - Brigitte Pelzmann
- Institute of Biophysics, Center of Physiological Medicine, Medical University of Graz, Harrachgasse 21/IV, 8010 Graz, Austria
| | - Eva Bernhart
- Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University of Graz, Harrachgasse 21/III, 8010 Graz, Austria
| | - Wolfgang Sattler
- Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University of Graz, Harrachgasse 21/III, 8010 Graz, Austria
| | - Seth Hallström
- Institute of Physiological Chemistry, Center of Physiological Medicine, Medical University of Graz, Harrachgasse 21/II, 8010 Graz, Austria
| | - Tadeusz Malinski
- Nanomedical Research Laboratory, Department of Chemistry and Biochemistry, Ohio University, 350 West State Street, Athens, Ohio 45701, USA
| | - Markus Waldeck-Weiermair
- Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University of Graz, Harrachgasse 21/III, 8010 Graz, Austria
| | - Wolfgang F Graier
- Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University of Graz, Harrachgasse 21/III, 8010 Graz, Austria
| | - Roland Malli
- Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University of Graz, Harrachgasse 21/III, 8010 Graz, Austria
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Liu Y, Wang G, Yang M, Chen H, zhao Y, Yang S, Sun C. Arctigenin reduces blood pressure by modulation of nitric oxide synthase and NADPH oxidase expression in spontaneously hypertensive rats. Biochem Biophys Res Commun 2015; 468:837-42. [PMID: 26585490 DOI: 10.1016/j.bbrc.2015.11.041] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Accepted: 11/09/2015] [Indexed: 01/02/2023]
Abstract
Arctigenin is a bioactive constituent from dried seeds of Arctium lappa L., which was traditionally used as medicine. Arctigenin exhibits various bioactivities, but its effects on blood pressure regulation are still not widely studied. In this study, we investigated antihypertensive effects of arctigenin by long-term treatment in spontaneously hypertensive rats (SHRs). Arctigenin (50 mg/kg) or vehicle was administered to SHRs or Wistar rats as negative control by oral gavage once a day for total 8 weeks. Nifedipine (3 mg/kg) was used as a positive drug control. After treatment, hemodynamic and physical parameters, vascular reactivity in aorta, the concentration of plasma arctigenin and serum thromboxane B2, NO release and vascular p-eNOS, p-Akt, caveolin-1 protein expression, and vascular superoxide anion generation and p47phox protein expression were detected and analyzed. The results showed that arctigenin significantly reduced systolic blood pressure and ameliorated endothelial dysfunction of SHRs. Arctigenin reduced the levels of thromboxane B2 in plasma and superoxide anion in thoracic aorta of SHRs. Furthermore, arctigenin increased the NO production by enhancing the phosphorylation of Akt and eNOS (Ser 1177), and inhibiting the expression of NADPH oxidase in thoracic aorta of SHRs. Our data suggested that antihypertensive mechanisms of arctigenin were associated with enhanced eNOS phosphorylation and decreased NADPH oxidase-mediated superoxide anion generation.
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Affiliation(s)
- Ying Liu
- Department of Nutrition and Food Hygiene, Public Health College, Harbin Medical University, Harbin, PR China.
| | - Guoyuan Wang
- First Affiliated Hospital, Harbin Medical University, Harbin, PR China
| | - Mingguang Yang
- Third Affiliated Hospital, Harbin Medical University, Harbin, PR China
| | - Haining Chen
- Department of Nutrition and Food Hygiene, Public Health College, Harbin Medical University, Harbin, PR China
| | - Yan zhao
- Department of Nutrition and Food Hygiene, Public Health College, Harbin Medical University, Harbin, PR China
| | - Shucai Yang
- Department of Anatomy, Basic Medical Science College, Harbin Medical University, Harbin, PR China
| | - Changhao Sun
- Department of Nutrition and Food Hygiene, Public Health College, Harbin Medical University, Harbin, PR China
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Koskela S, Laine O, Mäkelä S, Pessi T, Tuomisto S, Huhtala H, Karhunen PJ, Pörsti I, Mustonen J. Endothelial Nitric Oxide Synthase G894T Polymorphism Associates with Disease Severity in Puumala Hantavirus Infection. PLoS One 2015; 10:e0142872. [PMID: 26561052 PMCID: PMC4641644 DOI: 10.1371/journal.pone.0142872] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2015] [Accepted: 10/27/2015] [Indexed: 11/25/2022] Open
Abstract
Introduction Hantavirus infections are characterized by both activation and dysfunction of the endothelial cells. The underlying mechanisms of the disease pathogenesis are not fully understood. Here we tested the hypothesis whether the polymorphisms of endothelial nitric oxide synthase, eNOS G894T, and inducible nitric oxide synthase, iNOS G2087A, are associated with the severity of acute Puumala hantavirus (PUUV) infection. Patients and Methods Hospitalized patients (n = 172) with serologically verified PUUV infection were examined. Clinical and laboratory variables reflecting disease severity were determined. The polymorphisms of eNOS G894T (Glu298Asp, rs1799983) and iNOS G2087A (Ser608Leu, rs2297518) were genotyped. Results The rare eNOS G894T genotype was associated with the severity of acute kidney injury (AKI). The non-carriers of G-allele (TT-homozygotes) had higher maximum level of serum creatinine than the carriers of G-allele (GT-heterozygotes and GG-homozygotes; median 326, range 102–1041 vs. median 175, range 51–1499 μmol/l; p = 0.018, respectively). The length of hospital stay was longer in the non-carriers of G-allele than in G-allele carriers (median 8, range 3–14 vs. median 6, range 2–15 days; p = 0.032). The rare A-allele carriers (i.e. AA-homozygotes and GA-heterozygotes) of iNOS G2087A had lower minimum systolic and diastolic blood pressure than the non-carriers of A-allele (median 110, range 74–170 vs.116, range 86–162 mmHg, p = 0.019, and median 68, range 40–90 vs. 72, range 48–100 mmHg; p = 0.003, respectively). Conclusions Patients with the TT-homozygous genotype of eNOS G894T had more severe PUUV-induced AKI than the other genotypes. The eNOS G894T polymorphism may play role in the endothelial dysfunction observed during acute PUUV infection.
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Affiliation(s)
- Sirpa Koskela
- Department of Internal Medicine, Tampere University Hospital, Tampere, Finland
- * E-mail:
| | - Outi Laine
- Department of Internal Medicine, Tampere University Hospital, Tampere, Finland
- School of Medicine, University of Tampere, Tampere, Finland
| | - Satu Mäkelä
- Department of Internal Medicine, Tampere University Hospital, Tampere, Finland
- School of Medicine, University of Tampere, Tampere, Finland
| | - Tanja Pessi
- School of Medicine, University of Tampere, Tampere, Finland
- Science Centre, Pirkanmaa Hospital District, Tampere, Finland
| | - Sari Tuomisto
- School of Medicine, University of Tampere, Tampere, Finland
- Fimlab Laboratories Ltd, Tampere, Finland
| | - Heini Huhtala
- School of Health Sciences, University of Tampere, Tampere, Finland
| | - Pekka J. Karhunen
- School of Medicine, University of Tampere, Tampere, Finland
- Fimlab Laboratories Ltd, Tampere, Finland
| | - Ilkka Pörsti
- Department of Internal Medicine, Tampere University Hospital, Tampere, Finland
- School of Medicine, University of Tampere, Tampere, Finland
| | - Jukka Mustonen
- Department of Internal Medicine, Tampere University Hospital, Tampere, Finland
- School of Medicine, University of Tampere, Tampere, Finland
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15
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Wang LY, Zhang JH, Yu J, Yang J, Deng MY, Kang HL, Huang L. Reduction of Store-Operated Ca(2+) Entry Correlates with Endothelial Progenitor Cell Dysfunction in Atherosclerotic Mice. Stem Cells Dev 2015; 24:1582-90. [PMID: 25753987 DOI: 10.1089/scd.2014.0538] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The dysfunction of endothelial progenitor cells (EPCs) has been shown to prevent endothelial repair during the development of atherosclerosis (AS). Previous studies have revealed that store-operated calcium entry (SOCE) is an important factor in regulating EPC functions. However, whether this is also the mechanism in AS has not been elucidated. Therefore, we evaluated the role of SOCE in EPCs isolated from an atherosclerotic mouse model. Atheromatous plaques were more frequent in the aortas of ApoE(-/-) mice fed a high-fat diet for 16 weeks compared with controls, and the proliferative and migratory activities of atherosclerotic EPCs were significantly decreased. Accordingly, SOCE amplitude, as well as spontaneous or VEGF-induced Ca(2+) oscillations, decreased in atherosclerotic EPCs. These results may be associated with the downregulated expression of Stim1, Orai1, and TRPC1, which are major mediators of SOCE. In addition, eNOS expression and phosphorylation at Ser(1177), which are critical regulators of EPC function, were markedly reduced in the atherosclerotic EPCs. The impairment of eNOS activity could also be induced by using an SOCE inhibitor or by Stim1 gene silencing, indicating a link between the activities of eNOS and SOCE in AS. Furthermore, decreased SOCE function inhibited EPC proliferation and migration in vitro. In conclusion, our results showed that the reduction of SOCE induced EPC dysfunction during AS, potentially through downregulation of store-operated calcium channel (SOCC) components and impaired eNOS activity. Approaches aimed at reestablishing SOCE activity may thus improve the function of EPCs during AS.
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Affiliation(s)
- Lian-You Wang
- Institute of Cardiovascular Diseases of PLA, Xinqiao Hospital, Third Military Medical University , Chongqing, People's Republic of China
| | - Ji-Hang Zhang
- Institute of Cardiovascular Diseases of PLA, Xinqiao Hospital, Third Military Medical University , Chongqing, People's Republic of China
| | - Jie Yu
- Institute of Cardiovascular Diseases of PLA, Xinqiao Hospital, Third Military Medical University , Chongqing, People's Republic of China
| | - Jie Yang
- Institute of Cardiovascular Diseases of PLA, Xinqiao Hospital, Third Military Medical University , Chongqing, People's Republic of China
| | - Meng-Yang Deng
- Institute of Cardiovascular Diseases of PLA, Xinqiao Hospital, Third Military Medical University , Chongqing, People's Republic of China
| | - Hua-Li Kang
- Institute of Cardiovascular Diseases of PLA, Xinqiao Hospital, Third Military Medical University , Chongqing, People's Republic of China
| | - Lan Huang
- Institute of Cardiovascular Diseases of PLA, Xinqiao Hospital, Third Military Medical University , Chongqing, People's Republic of China
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16
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Rocha BAM, Barroso-Neto IL, Teixeira CS, Santiago MQ, Pires AF, Souza LAG, Nascimento KS, Sampaio AH, Delatorre P, Assreuy AMS, Cavada BS. CRLI induces vascular smooth muscle relaxation and suggests a dual mechanism of eNOS activation by legume lectins via muscarinic receptors and shear stress. Arch Biochem Biophys 2014; 565:32-9. [PMID: 25444858 DOI: 10.1016/j.abb.2014.11.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Revised: 10/25/2014] [Accepted: 11/06/2014] [Indexed: 11/26/2022]
Abstract
Lectins are proteins able to recognize carbohydrates, without modifying their structure, via the carbohydrate-recognition domain (CRD). Here, the three-dimensional structure of the mannose-binding lectin isolated from Cymbosema roseum (CRLI) was determined with X-man molecule modeled into the carbohydrate recognition domain. CRLI relaxant activity in thoracic rat aorta was also investigated, and based on the results, a molecular docking of CRLI with heparan sulfate was performed to investigate the possible interaction with mechanoreceptors involved in vasorelaxation. CRLI (IC₅₀=12.4 μg mL(-)(1)) elicited vasorelaxant response (96%) in endothelialized rat aorta contracted with phenylephrine. Endothelium-derived relaxant factors, extracellular calcium (Ca(2+)e) and muscarinic receptors were also evaluated as putative participants in the CRLI relaxant effect. CRLI relaxant effect was blocked by L-NAME, a nonselective inhibitor of nitric oxide synthase (NOS), and partially inhibited in a calcium-free solution (0Ca) and by atropine, but it remained unchanged in the presence of indomethacin and TEA. In summary, our data suggest interaction between CRLI and muscarinic receptors located in vascular endothelial cells leading to NOS activation triggered by a mechanism that involves Ca(2+)e along with the ability of CRLI to interact with heparan sulfate, a highly rated mechanoreceptor involved in eNOS activation.
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Affiliation(s)
- Bruno A M Rocha
- Laboratório de Moléculas Biologicamente Ativas, Universidade Federal do Ceará, Fortaleza, Brazil
| | - Ito L Barroso-Neto
- Laboratório de Moléculas Biologicamente Ativas, Universidade Federal do Ceará, Fortaleza, Brazil
| | - Claudener S Teixeira
- Laboratório de Moléculas Biologicamente Ativas, Universidade Federal do Ceará, Fortaleza, Brazil; Departamento de Ciências Biológicas, Universidade Regional do Cariri, Campos Sales, Brazil
| | - Mayara Q Santiago
- Laboratório de Moléculas Biologicamente Ativas, Universidade Federal do Ceará, Fortaleza, Brazil
| | - Alana F Pires
- Instituto Superior de Ciências Biomédicas, Universidade Estadual do Ceará, Fortaleza, Brazil
| | - Luiz A G Souza
- Instituto Nacional de Pesquisas da Amazônia-INPA, Manaus, Amazonas, Brazil
| | - Kyria S Nascimento
- Laboratório de Moléculas Biologicamente Ativas, Universidade Federal do Ceará, Fortaleza, Brazil
| | - Alexandre H Sampaio
- Biomol-Mar, Departamento de Engenharia de Pesca, Universidade Federal do Ceará, Fortaleza, Brazil
| | - Plinio Delatorre
- Departamento de Biologia Molecular, Universidade Federal da Paraíba, João Pessoa, Brazil.
| | - Ana M S Assreuy
- Instituto Superior de Ciências Biomédicas, Universidade Estadual do Ceará, Fortaleza, Brazil
| | - Benildo S Cavada
- Laboratório de Moléculas Biologicamente Ativas, Universidade Federal do Ceará, Fortaleza, Brazil.
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17
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Vinet R, Cortés MP, Alvarez R, Delpiano MA. Bradykinin and histamine-induced cytosolic calcium increase in capillary endothelial cells of bovine adrenal medulla. Cell Biol Int 2014; 38:1023-31. [PMID: 24798323 DOI: 10.1002/cbin.10300] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Revised: 03/26/2014] [Accepted: 03/29/2014] [Indexed: 11/11/2022]
Abstract
We have assessed the effect of bradykinin and histamine on the cytosolic free calcium concentration ([Ca(2+)]i ) of bovine adrenal medulla capillary endothelial cells (BAMCECs). To measure [Ca(2+)]i changes in BAMCECs the intracellular fluorescent probe, fluo-3 AM, was used. Bradykinin (3 µM) produced a transient monophasic increase in [Ca(2+)]i , which was depressed by B1650 (0.1 µM), a B2-bradykinin receptor antagonist (D-Arg-[Hyp(3), Thi(5,8) , D-Phe(7)]-Bradykinin). Similarly, increase in [Ca(2+)]i induced by histamine was also depressed by tripolidine (0.1 µM), an H1-histamine receptor antagonist. [Ca(2+)]i increase induced by both agonists was unaffected in the absence of extracellular Ca(2+) or presence of antagonists of voltage operated Ca(2+) channels (VOCCs). Thapsigargin (1 µM) did not abolish the increase of [Ca(2+)]i produced by bradykinin, but abolished that of histamine. In contrast, caffeine (100 µM), abolished the [Ca(2+)]i response induced by bradykinin (3 µM), but did not affect the [Ca(2+)]i increase induced by histamine (100 µM). The results indicate the presence of B2 bradykinin- and H1 histamine-receptors in BAMCECs. Liberation of Ca(2+) induced by both agonists occurs through 2 different intracellular mechanisms. While bradykinin activates a sarco(endo) plasmic reticulum (SER) containing a SER Ca(2+) -ATPase (SERCA) thapsigargin-insensitive, histamine activates a SER containing a SERCA thapsigargin-sensitive. We suggest that the increase in [Ca(2+)]i induced by bradykinin and histamine could be of physiological relevance, modulating adrenal gland microcirculation.
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Affiliation(s)
- Raúl Vinet
- Laboratory of Pharmacology, Faculty of Pharmacy, Universidad de Valparaíso, Gran Bretaña 1093, 2360102 Valparaíso, Chile; Centro Regional de Estudios en Alimentos Saludables (CREAS), Región de Valparaíso, Avda. Universidad 330, 2360102 Valparaíso, Chile
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18
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Deak AT, Groschner LN, Alam MR, Seles E, Bondarenko AI, Graier WF, Malli R. The endocannabinoid N-arachidonoyl glycine (NAGly) inhibits store-operated Ca2+ entry by preventing STIM1-Orai1 interaction. J Cell Sci 2012; 126:879-88. [PMID: 23239024 DOI: 10.1242/jcs.118075] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The endocannabiniod anandamide (AEA) and its derivate N-arachidonoyl glycine (NAGly) have a broad spectrum of physiological effects, which are induced by both binding to receptors and receptor-independent modulations of ion channels and transporters. The impact of AEA and NAGly on store-operated Ca(2+) entry (SOCE), a ubiquitous Ca(2+) entry pathway regulating many cellular functions, is unknown. Here we show that NAGly, but not AEA reversibly hinders SOCE in a time- and concentration-dependent manner. The inhibitory effect of NAGly on SOCE was found in the human endothelial cell line EA.hy926, the rat pancreatic β-cell line INS-1 832/13, and the rat basophilic leukemia cell line RBL-2H3. NAGly diminished SOCE independently from the mode of Ca(2+) depletion of the endoplasmic reticulum, whereas it had no effect on Ca(2+) entry through L-type voltage-gated Ca(2+) channels. Enhanced Ca(2+) entry was effectively hampered by NAGly in cells overexpressing the key molecular constituents of SOCE, stromal interacting molecule 1 (STIM1) and the pore-forming subunit of SOCE channels, Orai1. Fluorescence microscopy revealed that NAGly did not affect STIM1 oligomerization, STIM1 clustering, or the colocalization of STIM1 with Orai1, which were induced by Ca(2+) depletion of the endoplasmic reticulum. In contrast, independently from its slow depolarizing effect on mitochondria, NAGly instantly and strongly diminished the interaction of STIM1 with Orai1, indicating that NAGly inhibits SOCE primarily by uncoupling STIM1 from Orai1. In summary, our findings revealed the STIM1-Orai1-mediated SOCE machinery as a molecular target of NAGly, which might have many implications in cell physiology.
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Affiliation(s)
- Andras T Deak
- Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University Graz, Graz, Austria
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19
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Bryan NS. Pharmacological therapies, lifestyle choices and nitric oxide deficiency: A perfect storm. Pharmacol Res 2012; 66:448-56. [DOI: 10.1016/j.phrs.2012.09.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2012] [Revised: 08/28/2012] [Accepted: 09/15/2012] [Indexed: 01/05/2023]
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20
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The importance of velocity acceleration to flow-mediated dilation. Int J Vasc Med 2012; 2012:589213. [PMID: 22315688 PMCID: PMC3270398 DOI: 10.1155/2012/589213] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2011] [Accepted: 10/12/2011] [Indexed: 01/22/2023] Open
Abstract
The validity of the flow-mediated dilation test has been questioned due to the lack of normalization to the primary stimulus, shear stress. Shear stress can be calculated using Poiseuille's law. However, little attention has been given to the most appropriate blood velocity parameter(s) for calculating shear stress. The pulsatile nature of blood flow exposes the endothelial cells to two distinct shear stimuli during the cardiac cycle: a large rate of change in shear at the onset of flow (velocity acceleration), followed by a steady component. The parameter typically entered into the Poiseuille's law equation to determine shear stress is time-averaged blood velocity, with no regard for flow pulsatility. This paper will discuss (1) the limitations of using Posieuille's law to estimate shear stress and (2) the importance of the velocity profile-with emphasis on velocity acceleration-to endothelial function and vascular tone.
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21
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Paciaroni M, Bogousslavsky J. Trafermin for stroke recovery: is it time for another randomized clinical trial? Expert Opin Biol Ther 2011; 11:1533-41. [DOI: 10.1517/14712598.2011.616888] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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22
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Félétou M. The Endothelium, Part I: Multiple Functions of the Endothelial Cells -- Focus on Endothelium-Derived Vasoactive Mediators. ACTA ACUST UNITED AC 2011. [DOI: 10.4199/c00031ed1v01y201105isp019] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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24
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The GPR55 agonist lysophosphatidylinositol directly activates intermediate-conductance Ca2+ -activated K+ channels. Pflugers Arch 2011; 462:245-55. [PMID: 21603896 PMCID: PMC3132407 DOI: 10.1007/s00424-011-0977-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2011] [Revised: 04/27/2011] [Accepted: 05/10/2011] [Indexed: 12/16/2022]
Abstract
Lysophosphatidylinositol (LPI) was recently shown to act both as an extracellular mediator binding to G protein-coupled receptor 55 (GPR55) and as an intracellular messenger directly affecting a number of ion channels including large-conductance Ca(2+) and voltage-gated potassium (BK(Ca)) channels. Here, we explored the effect of LPI on intermediate-conductance Ca(2+)-activated K(+) (IK(Ca)) channels using excised inside-out patches from endothelial cells. The functional expression of IK(Ca) was confirmed by the charybdotoxin- and TRAM-34-sensitive hyperpolarization to histamine and ATP. Moreover, the presence of single IK(Ca) channels with a slope conductance of 39 pS in symmetric K(+) gradient was directly confirmed in inside-out patches. When cytosolically applied in the range of concentrations of 0.3-10 μM, which are well below the herein determined critical micelle concentration of approximately 30 μM, LPI potentiated the IK(Ca) single-channel activity in a concentration-dependent manner, while single-channel current amplitude was not affected. In the whole-cell configuration, LPI in the pipette was found to facilitate membrane hyperpolarization in response to low (0.5 μM) histamine concentrations in a TRAM-34-sensitive manner. These results demonstrate a so far not-described receptor-independent effect of LPI on the IK(Ca) single-channel activity of endothelial cells, thus, highlighting LPI as a potent intracellular messenger capable of modulating electrical responses in the vasculature.
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Ghasemi M, Farrokhi-Khajeh-Pasha Y, Ostovaneh MR, Dehpour AR. Lithium decreased endothelium-mediated, but not nonadrenergic noncholinergic, relaxation of guinea pig corpus cavernosum in vitro: a role for nitrergic system. Fundam Clin Pharmacol 2011; 25:191-9. [DOI: 10.1111/j.1472-8206.2010.00825.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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26
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Werthmann RC, Lohse MJ, Bünemann M. Temporally resolved cAMP monitoring in endothelial cells uncovers a thrombin-induced [cAMP] elevation mediated via the Ca²+-dependent production of prostacyclin. J Physiol 2010; 589:181-93. [PMID: 21059757 DOI: 10.1113/jphysiol.2010.200121] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The barrier function of the endothelium is controlled by the second messengers Ca2+ and cAMP that differentially regulate the permeability of endothelial cells. The Ca2+-elevating agent thrombin has been demonstrated to increase endothelial permeability and to decrease cAMP levels as detected via enzyme immunoassays. To study the effects of thrombin on cAMP with high temporal resolution, we utilised the FRET-based cAMP sensor Epac1-camps in single intact human umbilical vein endothelial cells (HUVECs). In these cells, thrombin induced a delayed increase in [cAMP], initiating after about 40 s, with maximum cAMP levels after 130 s of thrombin application. This increase of cAMP levels was Ca2+-dependent, but did not require calmodulin (CaM). Pharmacological approaches revealed that phospholipase A2 (PLA2) activity and cyclooxygenase (COX)-mediated synthesis of prostaglandins was required for the thrombin-induced elevation of [cAMP]. Furthermore, preincubation of HUVECs with a prostacyclin-receptor antagonist significantly reduced the thrombin-induced increase in [cAMP]. We conclude that thrombin causes the synthesis of prostacyclin in endothelial cells and that the subsequent stimulation of Gs-coupled prostacyclin receptors then results in an increase in [cAMP].
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Affiliation(s)
- R C Werthmann
- Institute of Pharmacology and Toxicology, University of Würzburg, Versbacherstrasse 9, 97078 Würzburg, Germany
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Vang A, Mazer J, Casserly B, Choudhary G. Activation of endothelial BKCa channels causes pulmonary vasodilation. Vascul Pharmacol 2010; 53:122-9. [PMID: 20470901 DOI: 10.1016/j.vph.2010.05.001] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2009] [Revised: 04/28/2010] [Accepted: 05/06/2010] [Indexed: 12/21/2022]
Abstract
BACKGROUND Large-conductance Ca(2+)-activated K(+) (BK(Ca)) channels cause hyperpolarization and can regulate vascular tone. In this study, we evaluated the effect of endothelial BK(Ca) activation on pulmonary vascular tone. METHODS The presence of BK(Ca) channels in lung microvascular endothelial cells (LMVEC) and rat lung tissue was confirmed by RT-PCR, immunoblotting and immunohistochemistry. Isolated pulmonary artery (PA) rings and isolated ventilated-perfused rat lungs were used to assay the effects of BK(Ca) channel activation on endothelium-dependent vasodilation. RESULTS Immunoblotting and RT-PCR revealed the presence of BK(Ca) channel alpha- and beta(4)-subunits in LMVEC. Immunohistochemical staining showed BK(Ca) channel alpha-subunit expression in vascular endothelium in rat lungs. In arterial ring studies, BK(Ca) channel activation by NS1619 enhanced endothelium-dependent vasodilation that was attenuated by tetraethylammonium and iberiotoxin. In addition, activation of BK(Ca) channels by C-type natriuretic peptide caused endothelial-dependent vasodilation that was blocked by iberiotoxin, L-NAME, and lanthanum. Furthermore, BK(Ca) activation by NS1619 caused a dose-dependent reduction in PA pressures that was attenuated by L-NAME. In vitro, BK(Ca) channel activation in LMVEC caused hyperpolarization and increased NO production. CONCLUSIONS Pulmonary endothelium expresses BK(Ca) channels. Activation of endothelial BK(Ca) channels causes hyperpolarization and NO mediated endothelium-dependent vasodilation in micro- and macrovasculature in the lung.
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Affiliation(s)
- Alexander Vang
- Vascular Research Laboratory, Providence VA Medical Center, Providence, RI 02908, USA
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Kuhr F, Lowry J, Zhang Y, Brovkovych V, Skidgel RA. Differential regulation of inducible and endothelial nitric oxide synthase by kinin B1 and B2 receptors. Neuropeptides 2010; 44:145-54. [PMID: 20045558 PMCID: PMC2830320 DOI: 10.1016/j.npep.2009.12.004] [Citation(s) in RCA: 107] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2009] [Revised: 12/01/2009] [Accepted: 12/04/2009] [Indexed: 02/07/2023]
Abstract
Kinins are vasoactive peptides that play important roles in cardiovascular homeostasis, pain and inflammation. After release from their precursor kininogens, kinins or their C-terminal des-Arg metabolites activate two distinct G protein-coupled receptors (GPCR), called B2 (B2R) or B1 (B1R). The B2R is expressed constitutively with a wide tissue distribution. In contrast, the B1R is not expressed under normal conditions but is upregulated by tissue insult or inflammatory mediators. The B2R is considered to mediate many of the acute effects of kinins while the B1R is more responsible for chronic responses in inflammation. Both receptors can couple to Galphai and Galphaq families of G proteins to release mediators such as nitric oxide (NO), arachidonic acid, prostaglandins, leukotrienes and endothelium-derived hyperpolarizing factor and can induce the release of other inflammatory agents. The focus of this review is on the different transduction events that take place upon B2R and B1R activation in human endothelial cells that leads to generation of NO via activation of different NOS isoforms. Importantly, B2R-mediated eNOS activation leads to a transient ( approximately 5min) output of NO in control endothelial cells whereas in cytokine-treated endothelial cells, B1R activation leads to very high and prolonged ( approximately 90min) NO production that is mediated by a novel signal transduction pathway leading to post-translational activation of iNOS.
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Affiliation(s)
- F Kuhr
- Department of Pharmacology, University of Illinois at Chicago, College of Medicine, 835 South Wolcott, (M/C 868), Chicago, IL 60612, United States
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Oliveira APS, Lunardi CN, Rodrigues GJ, Bendhack LM. Relaxation induced by calcium ionophore is impaired in carotid arteries from 2K-1C rats due to failed effect of nitric oxide on the smooth muscle cells. Vascul Pharmacol 2009; 50:153-9. [PMID: 19100862 DOI: 10.1016/j.vph.2008.11.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2008] [Revised: 11/19/2008] [Accepted: 11/22/2008] [Indexed: 10/21/2022]
Abstract
Vascular endothelium generates nitric oxide (NO) in large vessels and induces relaxation of vascular smooth muscle cells (VSMC). The aim of this study was to evaluate the contribution of NO produced in the endothelial cells (EC) to the relaxation induced by the Ca2+ ionophore A23187 and whether this relaxation is impaired in renal hypertensive (2K-1C) rat arteries. Concentration-effect curves for A23187 were constructed in intact endothelium isolated carotid rings from 2K-1C and normotensive (2K) in the absence or in the presence of the extracellular NO scavenger haemoglobin or inhibitors of NO-synthase (NOS, L-NOARG), guanylyl-cyclase (GC, ODQ). In carotid rings loaded with Fluo-3AM, both EC and VSMC were simultaneously imaged by a confocal microscope and [Ca2+]c was derived from fluorescence intensities (IF). The maximal relaxation (ME) induced by A23187 was lower in 2K-1C than in 2K arteries. A23187-induced relaxation was abolished by haemoglobin and L-NOARG in both groups. ODQ reduced the ME to A23187 in 2K and abolished its relaxation in 2K-1C. A23187 increased [Ca2+]c in a similar way in 2K and 2K-1C EC, and decreased [Ca2+]c in VSMC, which effect was higher in 2K than in 2K-1C arteries. L-NOARG inhibited the effect of A23187 in VSMC from 2K and abolished it in 2K-1C rats. On the other hand, L-NOARG did not modify the effect of A23187 in EC from 2K and 2K-1C rats. The basal content of cGMP was higher in 2K than in 2K-1C arterial rings that was similarly increased by A23187. In conclusion, the Ca2+ ionophore A23187 increases Ca2+, activates NOS and NO production in the EC activating GC in VSMC and [Ca2+]c decrease. All these effects are higher in 2K, which contribute to the impaired relaxation to A23187 in 2K-1C rat arteries.
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Affiliation(s)
- Ana P S Oliveira
- Laboratório de Farmacología, Faculdade de Ciências Farmaocêuticas de Ribeirão Preto, Universidade de São Paulo, 14040-903 RibeirBo Preto, SP Brazil
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Korkmaz H, Karaca I, Koç M, Önalan O, Yilmaz M, Bilen MN. Early Effects of Treatment with Nebivolol and Quinapril on Endothelial Function in Patients with Hypertension. ACTA ACUST UNITED AC 2009; 15:149-55. [DOI: 10.1080/10623320802125565] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Lang D, Shah AM, Lewis MJ. Aniotensin-Converting Enzyme (ACE) Activity: Aortic ancf Endocardial Endothelium Compared. ACTA ACUST UNITED AC 2009. [DOI: 10.3109/10623329609024681] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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Zhirnov VV, Iakovenko IN. Ultra-low dose beta-irradiation induces constriction of rabbit carotid arteries via the endothelium. Int J Radiat Biol 2009; 81:813-20. [PMID: 16484150 DOI: 10.1080/09553000600562229] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
PURPOSE To investigate the action of ultra-low dose beta-radiation (ULDBR) on isolated segments of blood vessels. MATERIALS AND METHODS We used the pharmacological model of isolated rabbit carotid arteries with intact or mechanically removed endothelium. Specific vascular responses to beta-irradiation were registered after addition of (90)Sr in the concentration range between 12 and 96 microCi l(-1) to the organ bath containing physiological salt solution (PSS). RESULTS Intact vascular rings, preconstricted with 20 mM K(+)-PSS, developed an additional constriction upon the addition of (90)Sr depending on the absorbed radiation dose (21.5, 42.9, 85.8, and 171.6 microGy) and the dose rate (51.5, 103.0, 206.0 and 412.0 microGy h(-1)). The vasoconstriction due to (90)Sr was absent in the endothelium-denuded vascular segments indicating the endothelium dependent action of ULDBR. Irradiation did not alter the endothelium dependent relaxation of rabbit carotid arteries induced by acetylcholine. The endothelium dependent responses to ULDBR were abolished after increasing the extra-cellular K(+) to 40 mM. CONCLUSIONS ULDBR acts on rabbit carotid arteries as a pharmacological signalling agent because ULDBR effects were completely reversible. ULDBR-mediated contractile responses of the vessels are endothelium dependent. The resistance of acetylcholine endothelium-dependent relaxation of rabbit carotid arteries to ULDBR indicates that the polyphosphoinositide-nitric oxide (NO) signalling cascade is not impaired by ULDBR in endothelial cells.
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Affiliation(s)
- Victor V Zhirnov
- Department of Cell Signal Systems, Institute of Bioorganic Chemistry and Petrochemistry of National Academy of Sciences of Ukraine, Kiev, Ukraine.
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Fèlix C, Jacome P, Lòpez A, Moya W, Narvàez M, Lòpez-Jaramillo P. The hypotensive effect of calcium supplementation during normal pregnancy in Andean women is not related to vascular production of prostacyclin by umbilical arteries. J OBSTET GYNAECOL 2009. [DOI: 10.3109/01443619109013523] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Inhibition of the histamine-induced Ca2+ influx in primary human endothelial cells (HUVEC) by volatile anaesthetics. Eur J Anaesthesiol 2008; 25:976-85. [PMID: 18631421 DOI: 10.1017/s0265021508004778] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND OBJECTIVE Vasoactive substances such as histamine, acetylcholine or ATP increase the [Ca2+]i of endothelial cells, which leads to the activation of nitric oxide synthase (eNOS). The NO produced by this enzyme relaxes the underlying smooth muscle. Evidence suggests that eNOS activation is dependent on agonist-induced Ca2+ entry. Recently we have shown that in human endothelial cells (HUVEC), this Ca2+ entry is sensitive to isoflurane. The objective here was to study the mechanism by which volatile anaesthetics can depress the histamine-induced Ca2+ entry into HUVEC cells. METHODS HUVECs on coverslips were loaded with the Ca2+ indicator Fluo-3 and inserted in a gastight, temperature-controlled perfusion chamber. Excitation was at 488 nm and fluorescence signals were monitored with a confocal laser scanning microscope (MRC1024, Biorad). Direct measurement of the Ca2+ influx was with Mn2+ as surrogate for calcium at 360 nm in cells loaded with Fura-2. RESULTS Addition of histamine induces a biphasic [Ca2+]i increase consisting of Ca2+ release from internal stores and a Ca2+ influx from the external medium (plateau phase). The plateau phase was dose-dependently inhibited by enflurane and sevoflurane (13.7 resp. 21.9% inhibition by 1 MAC anaesthetic). Direct measurement of the Ca2+ influx using the Mn2+ quench of the Fura-2 fluorescence gave similar results. The inhibition of the anaesthetics was not reduced by inhibition of the cGMP pathway, inactivation of protein kinase C, depolarization of the cells or the presence of specific Ca2+-dependent K+ channel inhibitors. Interestingly, unsaturated fatty acids inhibit the histamine-induced Ca2+ influx in a similar way as the volatile anaesthetics. CONCLUSIONS Volatile anaesthetics dose-dependently inhibit the histamine-induced Ca2+ influx in HUVECs by a mechanism that may involve unspecific perturbation of the lipid bilayer.
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Sheng JZ, Arshad F, Braun JE, Braun AP. Estrogen and the Ca2+-mobilizing agonist ATP evoke acute NO synthesis via distinct pathways in an individual human vascular endothelium-derived cell. Am J Physiol Cell Physiol 2008; 294:C1531-41. [PMID: 18367584 DOI: 10.1152/ajpcell.00561.2007] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In this study, we have systematically evaluated the signaling mechanisms underlying stimulated nitric oxide (NO) synthesis by estrogen (E2) and other vasoactive agents at the level of a single endothelium-derived cell. To do so, we have characterized and contrasted rapid E2-evoked NO synthesis with that of ATP using single-cell microfluorimetry and patch-clamp recordings to monitor stimulated changes in cellular NO synthesis (via 4-amino-5-methylamino-2',7'-difluorofluorescein), Ca2+ transients (via Fluo-3), and membrane hyperpolarization in cultured human EA.hy926 cells. E2-evoked NO synthesis in single cells (EC50 approximately 0.3 nM) was blocked by the E2 receptor antagonist ICI 182,780 and the NO synthase inhibitor N(omega)-nitro-l-arginine methyl ester. Although both E2 and ATP stimulated comparable Ca2+ transients, E2-induced NO synthesis was insensitive to intracellular BAPTA-AM or removal of external Ca2+. In contrast, ATP-evoked NO production was abolished by either one of these treatments. ATP-evoked hyperpolarizations ( approximately 20 mV) and NO production were both inhibited by the respective small-conductance and intermediate-conductance calcium- activated K+ channel blockers apamin and charybdotoxin. E2 minimally affected membrane potential, and stimulated NO synthesis was insensitive to calcium-activated K+ channel blockers. Exposure to either the phosphatidylinositol 3-kinase inhibitor LY-294002 or the MAP kinase inhibitor PD-98059 abolished the NO response to E2, but not that to ATP. Finally, the NO response evoked by a combined stimulus of E2 plus ATP was similar to that of ATP alone. In conclusion, our data directly demonstrate that an individual human EA.hy926 cell contains at least two distinct mechanisms for stimulated NO synthesis that depend on either calcium or protein kinase signaling events.
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Affiliation(s)
- Jian-Zhong Sheng
- Smooth Muscle Research Group, Libin Cardiovascular Institute and Department of Pharmacology and Therapeutics, Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada T2N 4N1
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Mitchell JA, Ali F, Bailey L, Moreno L, Harrington LS. Role of nitric oxide and prostacyclin as vasoactive hormones released by the endothelium. Exp Physiol 2007; 93:141-7. [DOI: 10.1113/expphysiol.2007.038588] [Citation(s) in RCA: 178] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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Harrington LS, Carrier MJ, Gallagher N, Gilroy D, Garland CJ, Mitchell JA. Elucidation of the temporal relationship between endothelial-derived NO and EDHF in mesenteric vessels. Am J Physiol Heart Circ Physiol 2007; 293:H1682-8. [PMID: 17557917 DOI: 10.1152/ajpheart.00389.2007] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Although the endothelium co-generates both nitric oxide (NO) and endothelium-derived hyperpolarizing factor (EDHF), the relative contribution from each vasodilator is not clear. In studies where the endothelium is stimulated acutely, EDHF responses predominate in small arteries. However, the temporal relationship between endothelial-derived NO and EDHF over more prolonged periods is unclear but of major physiological importance. Here we have used a classical pharmacological approach to show that EDHF is released transiently compared with NO. Acetylcholine (3 x 10(-6) mol/l) dilated second- and/or third-order mesenteric arteries for prolonged periods of up to 1 h, an effect that was reversed fully and immediately by the subsequent addition of L-NAME (10(-3) mol/l) but not TRAM-34 (10(-6) mol/l) plus apamin (5 x 10(-7) mol/l). When vessels were pretreated with L-NAME, acetylcholine induced relatively transient dilator responses (declining over approximately 5 min), and vessels were sensitive to TRAM-34 plus apamin. When measured in parallel, the dilator effects of acetylcholine outlasted the smooth muscle hyperpolarization. However, in the presence of L-NAME, vasodilatation and hyperpolarization followed an identical time course. In vessels from NOSIII(-/-) mice, acetylcholine induced small but detectable dilator responses that were transient in duration and blocked by TRAM-34 plus apamin. EDHF responses in these mouse arteries were inhibited by an intracellular calcium blocker, TMB-8, and the phospholipase A(2) inhibitor AACOCF(3), suggesting a role for lipid metabolites. These data show for the first time that EDHF is released transiently, whereas endothelial-derived NO is released in a sustained manner.
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Affiliation(s)
- Louise S Harrington
- Cardiothoracic Pharmacology, Unit of Critical Care Medicine, The National Heart and Lung Institute, Imperial College, London, United Kingdom
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Sheng JZ, Braun AP. Small- and intermediate-conductance Ca2+-activated K+ channels directly control agonist-evoked nitric oxide synthesis in human vascular endothelial cells. Am J Physiol Cell Physiol 2007; 293:C458-67. [PMID: 17459950 DOI: 10.1152/ajpcell.00036.2007] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The contribution of small-conductance (SK(Ca)) and intermediate-conductance Ca(2+)-activated K(+) (IK(Ca)) channels to the generation of nitric oxide (NO) by Ca(2+)-mobilizing stimuli was investigated in human umbilical vein endothelial cells (HUVECs) by combining single-cell microfluorimetry with perforated patch-clamp recordings to monitor agonist-evoked NO synthesis, cytosolic Ca(2+) transients, and membrane hyperpolarization in real time. ATP or histamine evoked reproducible elevations in NO synthesis and cytosolic Ca(2+), as judged by 4-amino-5-methylamino-2',7'-difluorofluorescein (DAF-FM) and fluo-3 fluorescence, respectively, that were tightly associated with membrane hyperpolarizations. Whereas evoked NO synthesis was unaffected by either tetraethylammonium (10 mmol/l) or BaCl(2) (50 micromol/l) + ouabain (100 micromol/l), depleting intracellular Ca(2+) stores by thapsigargin or removing external Ca(2+) inhibited NO production, as did exposure to high (80 mmol/l) external KCl. Importantly, apamin and charybdotoxin (ChTx)/ triarylmethane (TRAM)-34, selective blockers SK(Ca) and IK(Ca) channels, respectively, abolished both stimulated NO synthesis and membrane hyperpolarization and decreased evoked Ca(2+) transients. Apamin and TRAM-34 also inhibited an agonist-induced outwardly rectifying current characteristic of SK(Ca) and IK(Ca) channels. Under voltage-clamp control, we further observed that the magnitude of agonist-induced NO production varied directly with the degree of membrane hyperpolarization. Mechanistically, our data indicate that SK(Ca) and IK(Ca) channel-mediated hyperpolarization represents a critical early event in agonist-evoked NO production by regulating the influx of Ca(2+) responsible for endothelial NO synthase activation. Moreover, it appears that the primary role of agonist-induced release of intracellular Ca(2+) stores is to trigger the opening of both K(Ca) channels along with Ca(2+) entry channels at the plasma membrane. Finally, the observed inhibition of stimulated NO synthesis by apamin and ChTx/TRAM-34 demonstrates that SK(Ca) and IK(Ca) channels are essential for NO-mediated vasorelaxation.
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Affiliation(s)
- Jian-Zhong Sheng
- Department of Pharmacology and Therapeutics, University of Calgary, Alberta, Canada T2N 4N1
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Rodríguez-Rodríguez R, Herrera MD, Perona JS, Ruiz-Gutiérrez V. Potential vasorelaxant effects of oleanolic acid and erythrodiol, two triterpenoids contained in ‘orujo’ olive oil, on rat aorta. Br J Nutr 2007; 92:635-42. [PMID: 15522132 DOI: 10.1079/bjn20041231] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
‘Orujo’ olive oil is obtained by chemical processes from the waste resulting from the mechanical extraction of virgin olive oil. The aim of the present study was to evaluate a new pharmacological property of two natural triterpenoids contained in olive oil, as vasodilatory agents, and to determine their mechanism of action. The two compounds studied were oleanolic acid and erythrodiol. The vasorelaxant effect induced by these pentacyclic triterpenoids was studied in isolated thoracic rat aorta. Oleanolic acid and erythrodiol, accumulatively added, showed vasorelaxant activities in aortic rings with endothelium pre-contracted by 10−6M-phenylephrine (maximum percentage of relaxation 86·38 (SEM 2·89) and 73·53 (SEM 6·01), respectively). They had almost no relaxant effect on depolarised or endothelium-denuded aortic segments. The relaxation was significantly attenuated by pre-treatment with the NO synthase inhibitor Nω-nitro-L-arginine-methylester (L-NAME; 3×10−4m). To characterise the involvement of endothelial factors, in addition to NO, arteries with endothelium were exposed to 10−5M-indomethacin (INDO), a cyclo-oxygenase inhibitor, or INDO plus L-NAME. INDO did not have any significant effect on the relaxant response of both compounds. The combination of L-NAME plus INDO only abolished the oleanolic acid-induced relaxation. The present results suggest that the mechanism of relaxation seems to be mainly mediated by the endothelial production of NO; however, other mechanisms cannot be excluded. It can be concluded that oleanolic acid and erythrodiol may have interesting therapeutic potential as new vasodilator drugs, thus protecting the cardiovascular system. Therefore, the intake of ‘orujo’ olive oil, as a source of these compounds, might be beneficial in this regard.
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Affiliation(s)
- Rosalía Rodríguez-Rodríguez
- Instituto de la Grasa, Consejo Superior de Investigaciones Científicas, Avda Padre García Tejero n. 4, 41012 Sevilla, Spain
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Sadeghipour H, Ghasemi M, Ebrahimi F, Dehpour AR. Effect of lithium on endothelium-dependent and neurogenic relaxation of rat corpus cavernosum: Role of nitric oxide pathway. Nitric Oxide 2007; 16:54-63. [PMID: 16828320 DOI: 10.1016/j.niox.2006.05.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2006] [Revised: 05/08/2006] [Accepted: 05/24/2006] [Indexed: 11/29/2022]
Abstract
INTRODUCTION Some studies have reported erectile dysfunction in patients receiving lithium through a mechanism that has not yet been defined. The aim of the present study was to verify the effect of acute lithium administration on the nonadrenergic noncholinergic (NANC)- and endothelium-mediated relaxation of rat isolated corpus cavernosum. MATERIALS AND METHODS The isolated rat corporeal strips were precontracted with phenylephrine hydrochloride (7.5 microM) and electrical field stimulation (EFS) was applied at different frequencies (2, 5, 10, and 15 Hz) to obtain NANC-mediated relaxation or relaxed by adding cumulative doses of acetylcholine (10nM-1mM) to obtain endothelium-dependent relaxation in the presence or absence of lithium (0.3, 0.5, 1, and 5mM). Also, effects of combining lithium (0.3mM) with 30 nM and 0.1 nM L-NAME (an NO synthase inhibitor) on NANC- and acetylcholine-mediated relaxation was investigated, respectively. Moreover, effects of combining lithium (1mM) with 0.1mM and 10 microM L-arginine (a precursor of NO) on NANC- and endothelium-mediated relaxation was assessed, respectively. Also, the effect of lithium (1mM) on relaxation to sodium nitroprusside (SNP; 1nM-1mM), an NO donor, was investigated. RESULTS The NANC-mediated relaxation was significantly (P<0.001) reduced by 1 and 5mM, but not by 0.3 and 0.5mM lithium. Lithium significantly (P<0.001) attenuated the maximum response to acetylcholine in a concentration-dependent manner. Combination of lithium (0.3mM) with 30 and 0.1 nM L-NAME, which separately had a minimum effect on NANC- and endothelium-mediated relaxation, significantly (P<0.001) reduced the NANC- and endothelium-mediated relaxation, respectively. Although L-arginine at 10 microM and 0.1mM did not alter the relaxant responses to acetylcholine and EFS, it improved the inhibition by lithium (1mM) of relaxant responses to acetylcholine and EFS, respectively. Also, SNP produced similar concentration-dependent relaxations from both groups. DISCUSSION Our experiments indicated that lithium likely by interfering with NO pathway in both endothelium and nitrergic nerve can result in impairment of both the endothelium- and NANC-mediated relaxation of rat corpus cavernosum.
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Affiliation(s)
- Hamed Sadeghipour
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
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Sadeghipour H, Ghasemi M, Nobakht M, Ebrahimi F, Dehpour AR. Effect of chronic lithium administration on endothelium-dependent relaxation of rat corpus cavernosum: the role of nitric oxide and cyclooxygenase pathways. BJU Int 2007; 99:177-82. [PMID: 17034495 DOI: 10.1111/j.1464-410x.2006.06530.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
OBJECTIVE To verify the effect of chronic lithium administration on the endothelium-dependent relaxation of rat corpus cavernosum, as lithium is a major drug for treating bipolar disorder and some studies showed that lithium might cause erectile dysfunction in such patients, by a mechanism as yet unknown. MATERIALS AND METHODS LiCl (600 mg/L) was dissolved in drinking water and Sprague-Dawley rats received the solution for 30 days; control rats received tap water. After 30 days corporeal strips were prepared from both groups, mounted under tension in oxygenated organ baths, and pre-contracted with phenylephrine (7.5 microm). After equilibration, the strips were relaxed by acetylcholine (10 nm to 1 mm) in the presence or absence of indomethacin (a cyclooxygenase inhibitor; 20 microm). Furthermore, the relaxant responses to sodium nitroprusside (1 nm to 1 mm), a nitric oxide (NO) donor, were investigated in both groups. NADPH-diaphorase histochemistry was used to identify NO synthase within cavernosal tissue strips of both groups. RESULTS The acetylcholine-dependent relaxation was significantly lower in lithium-treated rats than in controls. Although indomethacin decreased significantly the relaxant responses to acetylcholine in controls, it increased the relaxant responses in lithium-treated rats. NADPH-diaphorase staining was greater in the chronic lithium-treated than in control preparations. Sodium nitroprusside produced similar relaxation in both groups. CONCLUSION Chronic lithium administration can impair the endothelium-dependent relaxation of rat corpus cavernosum; NO availability might decrease after lithium administration and the cyclooxygenase pathways might have a role in this effect.
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Affiliation(s)
- Hamed Sadeghipour
- Department of Pharmacology, School of Medicine, Sina Hospital, Tehran University of Medical Sciences, Tehran, Iran
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Jiang JG, Chen RJ, Xiao B, Yang S, Wang JN, Wang Y, Cowart LA, Xiao X, Wang DW, Xia Y. Regulation of endothelial nitric-oxide synthase activity through phosphorylation in response to epoxyeicosatrienoic acids. Prostaglandins Other Lipid Mediat 2007; 82:162-74. [PMID: 17164144 DOI: 10.1016/j.prostaglandins.2006.08.005] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2006] [Revised: 08/25/2006] [Accepted: 08/29/2006] [Indexed: 11/29/2022]
Abstract
Endothelial nitric oxide synthase (eNOS) is a key enzyme in NO-mediated cardiovascular homeostasis and its activity is modulated by a variety of hormonal and mechanical stimuli via phosphorylation modification. Our previous study has demonstrated that epoxyeicosatrienoic acids (EETs), the cytochrome P450 (CYP)-dependent metabolites of arachidonic acid, could robustly up-regulate eNOS expression. However, the molecular mechanism underlying the effects of EETs on eNOS remains elusive. Particularly, whether and how EETs affect eNOS phosphorylation is unknown. In the present study, we investigated the effects of EETs on eNOS phosphorylation with cultured bovine aortic endothelial cells (BAECs). BAECs were either treated with exogenous EETs or infected with recombinant adeno-associated virus (rAAV) carrying CYP2C11-CYPOR, CYP102 F87V mutant and CYP2J2, respectively, to increase endogenous EETs. Both addition of EETs and CYP epoxygenase transfection markedly increased eNOS phosphorylation at its Ser1179 and Thr497 residues. Inhibition of phosphatidylinositol 3-kinase (PI3K) with LY294002 prevented EETs-induced increases of eNOS-Ser(P)1179 but had no effect on the phosphorylation status of Thr497. However, inhibitors of protein kinase B (Akt), mitogen-activated protein kinase (MAPK) and MAPK kinase could block phosphorylation of eNOS at both sites. Inhibition of these kinases also attenuated the up-regulation of eNOS expression by EETs. Finally, administration of viral CYP epoxygenases expression vectors into rats enhanced eNOS phosphorylation and function in vivo. Thus, in addition to up-regulating eNOS expression, EETs also augment eNOS function by enhancing eNOS phosphorylation. EETs-induced up-regulation of eNOS phosphorylation and expression appears to involve in both PI3K/Akt and MAPK pathways.
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Affiliation(s)
- Jian Gang Jiang
- The Institute of Hypertension and Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science & Technology, Wuhan 430030, China
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45
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Abstract
The endothelium controls vascular tone not only by releasing nitric oxide (NO) and prostacyclin but also by other pathways causing hyperpolarization of the underlying smooth muscle cells. This characteristic was at the origin of the denomination endothelium-derived hyperpolarizing factor (EDHF). We know now that this acronym includes different mechanisms. In general, EDHF-mediated responses involve an increase in the intracellular calcium concentration, the opening of calcium-activated potassium channels of small and intermediate conductance and the hyperpolarization of the endothelial cells. This results in an endothelium-dependent hyperpolarization of the smooth muscle cells, which can be evoked by direct electrical coupling through myo-endothelial junctions and/or the accumulation of potassium ions in the intercellular space. Potassium ions hyperpolarize the smooth muscle cells by activating inward rectifying potassium channels and/or Na+/K(+)-ATPase. In some blood vessels, including large and small coronary arteries, the endothelium releases arachidonic acid metabolites derived from cytochrome P450 monooxygenases. The epoxyeicosatrienoic acids (EET) generated are not only intracellular messengers but also can diffuse and hyperpolarize the smooth muscle cells by activating large conductance calcium-activated potassium channels. Additionally, the endothelium can produce other factors such as lipoxygenases derivatives or hydrogen peroxide (H2O2). These different mechanisms are not necessarily exclusive and can occur simultaneously.
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Affiliation(s)
- Michel Félétou
- Department of Angiology, Institut de Recherches Servier, Suresnes, France
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46
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Abstract
Major advances have been made over the last decade towards the elucidation of the molecular mechanisms involved in the endothelium-dependent regulation of vascular tone and blood flow. While the primary endothelium-derived vasodilator autacoid is nitric oxide, it is clear that epoxyeicosatrienoic acids and other endothelium-derived hyperpolarising factors, as well as endothelin-1 and reactive oxygen species, play a significant role in the regulation of vascular tone and gene expression. This review is intended as an overview of the signalling mechanisms that link haemodynamic stimuli (such as shear stress and cyclic stretch) and endothelial cell perturbation to the activation of enzymes generating vasoactive autacoids.
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Affiliation(s)
- R Busse
- Vascular Signalling Group, Institut für Kardiovaskuläre Physiologie, Klinikum der J.W. Goethe-Universität, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany
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Abstract
The vascular endothelium synthesises the vasodilator and anti-aggregatory mediator nitric oxide (NO) from L-arginine. This action is catalysed by the action of NO synthases, of which two forms are present in the endothelium. Endothelial (e)NOS is highly regulated, constitutively active and generates NO in response to shear stress and other physiological stimuli. Inducible (i)NOS is expressed in response to immunological stimuli, is transcriptionally regulated and, once activated, generates large amounts of NO that contribute to pathological conditions. The physiological actions of NO include the regulation of vascular tone and blood pressure, prevention of platelet aggregation and inhibition of vascular smooth muscle proliferation. Many of these actions are a result of the activation by NO of the soluble guanylate cyclase and consequent generation of cyclic guanosine monophosphate (cGMP). An additional target of NO is the cytochrome c oxidase, the terminal enzyme in the electron transport chain, which is inhibited by NO in a manner that is reversible and competitive with oxygen. The consequent reduction of cytochrome c oxidase leads to the release of superoxide anion. This may be an NO-regulated cell signalling system which, under certain circumstances, may lead to the formation of the powerful oxidant species, peroxynitrite, that is associated with a variety of vascular diseases.
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Affiliation(s)
- S Moncada
- The Wolfson Institute for Biomedical Research, University College London, Gower Street, London WC1E 6BT, UK.
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Madeira SVF, de Castro Resende A, Ognibene DT, de Sousa MAV, Soares de Moura R. Mechanism of the endothelium-dependent vasodilator effect of an alcohol-free extract obtained from a vinifera grape skin. Pharmacol Res 2005; 52:321-7. [PMID: 16023862 DOI: 10.1016/j.phrs.2005.05.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2005] [Revised: 05/10/2005] [Accepted: 05/13/2005] [Indexed: 10/25/2022]
Abstract
An alcohol-free grape-skin extract (GSE) obtained from skins of Vitis labrusca has significant anti-hypertensive, antioxidant and vasodilator effects. According to our previous results, the vasodilator effect of GSE in the isolated mesenteric vascular bed (MVB) of the rat is dependent on endothelium and partially dependent on nitric oxide (NO). In the MVB of the rat pre-contracted with norepinephrine (NE), bolus injections of GSE induced a long-lasting dose-dependent vasodilation that is significantly reduced after the treatment with 1H-[1,2,3] oxadiazolo [4,4-a] quinoxalin-1-one (ODQ). Additionally, in vessels pre-contracted with norepinephrine and depolarized with KCl (25 mM) or treated with Ca(2+)-dependent K(+)-channel blockers charybdotoxin (ChTx) plus apamin, the vasodilator effect of GSE was significantly reduced and almost abolished by ChTx plus apamin plus L-NAME. However, the vasodilator effect of GSE was unaffected by D-Arg[Hyp(3),Thi(5),D-Tic(7),Oic(8)]bradykinin (HOE-140), atropine, yohimbine, pyrilamine and 4-aminopyridine (4-AP). The vasoconstriction response elicited by bolus injection of KCl was not affected by GSE, whereas the vasoconstrictor response induced by NE was dose-dependently and completed inhibited by GSE in the presence but not in the absence of endothelium. However, NE-induced vasoconstriction in calcium-free condition or without endothelium was not reduced by GSE. The present results demonstrate that GSE induces a vasodilator effect in the rat MVB, which is dependent on NO in combination with endothelium-derived hyperpolarizing factor (EDHF). Additionally, our results indicated that extracellular Ca(2+) has an important role on the endothelium-dependent vasodilator effect induced by GSE.
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Affiliation(s)
- Socorro Vanesca Frota Madeira
- Department of Pharmacology, IBRAG-CB State University of Rio de Janeiro, Av. 28 de setembro, 87, CEP 20551-030 Rio de Janeiro, Brazil
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Fernandes L, Fortes ZB, Casarini DE, Nigro D, Tostes RCA, Santos RAS, de Carvalho MHC. Role of PGI2 and effects of ACE inhibition on the bradykinin potentiation by angiotensin-(1-7) in resistance vessels of SHR. ACTA ACUST UNITED AC 2005; 127:183-9. [PMID: 15680485 DOI: 10.1016/j.regpep.2004.12.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2004] [Accepted: 12/01/2004] [Indexed: 01/09/2023]
Abstract
The present study determined the participation of PGI2 in the angiotensin-(1-7) [Ang-(1-7)]/bradykinin (BK) interaction, in the presence and absence of Angiotensin Converting Enzyme (ACE) inhibition, trying to correlate it with tissue levels of both peptides. The isolated mesenteric arteriolar bed of Spontaneously Hypertensive Rats (SHR) was perfused with Krebs or Krebs plus enalaprilat (10 nM), and drugs were injected alone or in association. BK (10 ng)-induced relaxation was potentiated by Ang-(1-7) (2.2 microg) in the presence or absence of enalaprilat. Ang-(1-7) receptor blockade [A-779 (4.8 microg)] did not interfere with the BK effect in preparations perfused with normal Krebs, but reversed the increased BK relaxation observed after ACE inhibition. PGI2 release by mesenteric vessels was not altered by BK or Ang-(1-7) alone, but was increased when both peptides were injected in association, in the absence or in the presence of enalaprilat. ACE inhibition caused a 2-fold increase in the BK tissue levels, and a significant decrease in the Ang-(1-7) values. We conclude that endogenous Ang-(1-7) has an important contribution to the effect of ACE inhibitors participating in the enhancement of BK response. The mechanism of Ang-(1-7) potentiating effect probably involves an increased production of PGI2. Our results suggest that a different enzymatic pathway (non-related to ACE) is involved in the local Ang-(1-7) metabolism.
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Affiliation(s)
- Liliam Fernandes
- Department of Pharmacology, Institute of Biomedical Sciences, University of São Paulo, São Paulo-SP 05508900, Brazil.
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Bauer G, . CS, . AE, . HT, . BW, . CK, . JW, Munz B. Dietary Flavonoid Phloretin Modulates Ca2+-activated K+ Channels Resulting in an Increase of Endothelial Nitric Oxide Production. INT J PHARMACOL 2004. [DOI: 10.3923/ijp.2005.38.43] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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