1
|
Zinkevich NS, Drachuk K, Zhang DX. Prolonged L-NAME exposure changes the vasodilator factor from NO to H 2O 2 in human arterioles in response to A23187. Vascul Pharmacol 2024; 157:107440. [PMID: 39537001 PMCID: PMC11624973 DOI: 10.1016/j.vph.2024.107440] [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: 09/10/2024] [Revised: 11/05/2024] [Accepted: 11/09/2024] [Indexed: 11/16/2024]
Abstract
The Ca2+ ionophore A23187 induces endothelium-dependent and non-receptor-mediated vasodilation in human adipose arterioles (HAAs). The purpose of this study was to determine the mechanism of A23187-induced dilation in HAAs from patients with and without coronary artery disease (CAD). HAAs were freshly isolated from adipose tissues obtained from non-CAD (n = 25) and CAD (n = 14) patients, and vascular reactivity was studied by videomicroscopy. No difference in baseline dose response to A23187 was observed between non-CAD and CAD subjects. However, acute (30 min) incubation with N(omega)-nitro-l-arginine methyl ester (L-NAME), NO synthase inhibitor strongly reduced A23187-induced dilation in non-CAD arterioles, while catalase, an H2O2 scavenger, largely abolished dilation in CAD. Surprising, prolonged (90 min) incubation with L-NAME restored A23187 response in non-CAD subjects, which was subsequently inhibited by catalase. The action of prolonged L-NAME exposure was not reversible after washing with Krebs while the effect of acute L-NAME exposure was largely reversible. To further determine the role of mitochondria-derived ROS in A23187-induced dilation, arterioles were treated with rotenone, an inhibitor of complex I of the electron transport chain. Rotenone abolished A23187 response in CAD patients and in non-CAD arterioles after prolonged L-NAME, but not in non-CAD controls. These data indicate that NO contributes to A23187-induced dilation in HAAs from non-CAD patients and H2O2 contributes to the dilation in CAD patients. Prolonged L-NAME exposure induces a NO-H2O2 switch in the mechanism of dilation in non-CAD subjects. Moreover, the effect of prolonged L-NAME exposure is not readily reversible, while the action of acute L-NAME exposure is reversible.
Collapse
Affiliation(s)
- Natalya S Zinkevich
- College of Health, Science and Technology, School of Integrated Sciences, Sustainability, and Public Health, Biology, University of Illinois Springfield, Springfield, IL 62703-5407, USA; Department of Medicine, Medical College of Wisconsin, Milwaukee, WI 53226, USA; Department of Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA.
| | - Kostiantyn Drachuk
- Department of Medicine, Medical College of Wisconsin, Milwaukee, WI 53226, USA; Department of Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA.
| | - David X Zhang
- Department of Medicine, Medical College of Wisconsin, Milwaukee, WI 53226, USA; Department of Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA.
| |
Collapse
|
2
|
Carrara E, Soliveri L, Poloni S, Bozzetto M, Campiglio CE. Effects of high-frequency mechanical stimuli on flow related vascular cell biology. Int J Artif Organs 2024; 47:590-601. [PMID: 39166431 PMCID: PMC11487902 DOI: 10.1177/03913988241268105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Accepted: 07/12/2024] [Indexed: 08/23/2024]
Abstract
Mechanical forces related to blood pressure and flow patterns play a crucial role in vascular homeostasis. Perturbations in vascular stresses and strain resulting from changes in hemodynamic may occur in pathological conditions, leading to vascular dysfunction as well as in vascular prosthesis, arteriovenous shunt for hemodialysis and in mechanical circulation support. Turbulent-like blood flows can induce high-frequency vibrations of the vessel wall, and this stimulus has recently gained attention as potential contributors to vascular pathologies, such as development of intimal hyperplasia in arteriovenous fistula for hemodialysis. However, the biological response of vascular cells to this stimulus remains incompletely understood. This review provides an analysis of the existing literature concerning the impact of high-frequency stimuli on vascular cell morphology, function, and gene expression. Morphological and functional investigations reveal that vascular cells stimulated at frequencies higher than the normal heart rate exhibit alterations in cell shape, alignment, and proliferation, potentially leading to vessel remodeling. Furthermore, vibrations modulate endothelial and smooth muscle cells gene expression, affecting pathways related to inflammation, oxidative stress, and muscle hypertrophy. Understanding the effects of high-frequency vibrations on vascular cells is essential for unraveling the mechanisms underlying vascular diseases and identifying potential therapeutic targets. Nevertheless, there are still gaps in our understanding of the molecular pathways governing these cellular responses. Further research is necessary to elucidate these mechanisms and their therapeutic implications for vascular diseases.
Collapse
Affiliation(s)
- Elena Carrara
- Department of Biomedical Engineering, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Luca Soliveri
- Department of Biomedical Engineering, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Sofia Poloni
- Department of Engineering and Applied Sciences, University of Bergamo, Dalmine, Italy
| | - Michela Bozzetto
- Department of Biomedical Engineering, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Chiara Emma Campiglio
- Department of Management, Information and Production Engineering, University of Bergamo, Dalmine, Italy
| |
Collapse
|
3
|
Mironova GY, Kowalewska PM, El-Lakany M, Tran CHT, Sancho M, Zechariah A, Jackson WF, Welsh DG. The conducted vasomotor response and the principles of electrical communication in resistance arteries. Physiol Rev 2024; 104:33-84. [PMID: 37410448 PMCID: PMC11918294 DOI: 10.1152/physrev.00035.2022] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 06/26/2023] [Accepted: 07/01/2023] [Indexed: 07/07/2023] Open
Abstract
Biological tissues are fed by arterial networks whose task is to set blood flow delivery in accordance with energetic demand. Coordinating vasomotor activity among hundreds of neighboring segments is an essential process, one dependent upon electrical information spreading among smooth muscle and endothelial cells. The "conducted vasomotor response" is a functional expression of electrical spread, and it is this process that lies at the heart of this critical review. Written in a narrative format, this review first highlights historical manuscripts and then characterizes the conducted response across a range of preparations. Trends are highlighted and used to guide subsequent sections, focused on cellular foundations, biophysical underpinnings, and regulation in health and disease. Key information has been tabulated; figures reinforce grounding concepts and reveal a framework within which theoretical and experimental work can be rationalized. This summative review highlights that despite 30 years of concerted experimentation, key aspects of the conducted response remain ill defined. Of note is the need to rationalize the regulation and deterioration of conduction in pathobiological settings. New quantitative tools, along with transgenic technology, are discussed as a means of propelling this investigative field forward.
Collapse
Affiliation(s)
- Galina Yu Mironova
- Department of Physiology and Pharmacology, Robarts Research Institute, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
| | - Paulina M Kowalewska
- Department of Physiology and Pharmacology, Robarts Research Institute, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
| | - Mohammed El-Lakany
- Department of Physiology and Pharmacology, Robarts Research Institute, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Alexandria University, Alexandria, Egypt
| | - Cam Ha T Tran
- Department of Physiology, Faculty of Medicine, University of Nevada (Reno), Reno, Nevada, United States
| | - Maria Sancho
- Department of Physiology, Faculty of Medicine, Complutense University of Madrid, Madrid, Spain
| | - Anil Zechariah
- Division of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland and Labrador, St. John's, Newfoundland, Canada
| | - William F Jackson
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Michigan, United States
| | - Donald G Welsh
- Department of Physiology and Pharmacology, Robarts Research Institute, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
| |
Collapse
|
4
|
Di X, Gao X, Peng L, Ai J, Jin X, Qi S, Li H, Wang K, Luo D. Cellular mechanotransduction in health and diseases: from molecular mechanism to therapeutic targets. Signal Transduct Target Ther 2023; 8:282. [PMID: 37518181 PMCID: PMC10387486 DOI: 10.1038/s41392-023-01501-9] [Citation(s) in RCA: 140] [Impact Index Per Article: 70.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 05/10/2023] [Accepted: 05/11/2023] [Indexed: 08/01/2023] Open
Abstract
Cellular mechanotransduction, a critical regulator of numerous biological processes, is the conversion from mechanical signals to biochemical signals regarding cell activities and metabolism. Typical mechanical cues in organisms include hydrostatic pressure, fluid shear stress, tensile force, extracellular matrix stiffness or tissue elasticity, and extracellular fluid viscosity. Mechanotransduction has been expected to trigger multiple biological processes, such as embryonic development, tissue repair and regeneration. However, prolonged excessive mechanical stimulation can result in pathological processes, such as multi-organ fibrosis, tumorigenesis, and cancer immunotherapy resistance. Although the associations between mechanical cues and normal tissue homeostasis or diseases have been identified, the regulatory mechanisms among different mechanical cues are not yet comprehensively illustrated, and no effective therapies are currently available targeting mechanical cue-related signaling. This review systematically summarizes the characteristics and regulatory mechanisms of typical mechanical cues in normal conditions and diseases with the updated evidence. The key effectors responding to mechanical stimulations are listed, such as Piezo channels, integrins, Yes-associated protein (YAP) /transcriptional coactivator with PDZ-binding motif (TAZ), and transient receptor potential vanilloid 4 (TRPV4). We also reviewed the key signaling pathways, therapeutic targets and cutting-edge clinical applications of diseases related to mechanical cues.
Collapse
Affiliation(s)
- Xingpeng Di
- Department of Urology and Institute of Urology, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, P.R. China
| | - Xiaoshuai Gao
- Department of Urology and Institute of Urology, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, P.R. China
| | - Liao Peng
- Department of Urology and Institute of Urology, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, P.R. China
| | - Jianzhong Ai
- Department of Urology and Institute of Urology, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, P.R. China
| | - Xi Jin
- Department of Urology and Institute of Urology, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, P.R. China
| | - Shiqian Qi
- Department of Urology and Institute of Urology, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, P.R. China
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu, P.R. China
| | - Hong Li
- Department of Urology and Institute of Urology, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, P.R. China
| | - Kunjie Wang
- Department of Urology and Institute of Urology, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, P.R. China.
| | - Deyi Luo
- Department of Urology and Institute of Urology, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, P.R. China.
| |
Collapse
|
5
|
Xie Y, Nishijima Y, Zinkevich NS, Korishettar A, Fang J, Mathison AJ, Zimmermann MT, Wilcox DA, Gutterman DD, Shen Y, Zhang DX. NADPH oxidase 4 contributes to TRPV4-mediated endothelium-dependent vasodilation in human arterioles by regulating protein phosphorylation of TRPV4 channels. Basic Res Cardiol 2022; 117:24. [PMID: 35469044 PMCID: PMC9119129 DOI: 10.1007/s00395-022-00932-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 04/11/2022] [Accepted: 04/12/2022] [Indexed: 02/07/2023]
Abstract
Impaired endothelium-dependent vasodilation has been suggested to be a key component of coronary microvascular dysfunction (CMD). A better understanding of endothelial pathways involved in vasodilation in human arterioles may provide new insight into the mechanisms of CMD. The goal of this study is to investigate the role of TRPV4, NOX4, and their interaction in human arterioles and examine the underlying mechanisms. Arterioles were freshly isolated from adipose and heart tissues obtained from 71 patients without coronary artery disease, and vascular reactivity was studied by videomicroscopy. In human adipose arterioles (HAA), ACh-induced dilation was significantly reduced by TRPV4 inhibitor HC067047 and by NOX 1/4 inhibitor GKT137831, but GKT137831 did not further affect the dilation in the presence of TRPV4 inhibitors. GKT137831 also inhibited TRPV4 agonist GSK1016790A-induced dilation in HAA and human coronary arterioles (HCA). NOX4 transcripts and proteins were detected in endothelial cells of HAA and HCA. Using fura-2 imaging, GKT137831 significantly reduced GSK1016790A-induced Ca2+ influx in the primary culture of endothelial cells and TRPV4-WT-overexpressing human coronary artery endothelial cells (HCAEC). However, GKT137831 did not affect TRPV4-mediated Ca2+ influx in non-phosphorylatable TRPV4-S823A/S824A-overexpressing HCAEC. In addition, treatment of HCAEC with GKT137831 decreased the phosphorylation level of Ser824 in TRPV4. Finally, proximity ligation assay (PLA) revealed co-localization of NOX4 and TRPV4 proteins. In conclusion, both TRPV4 and NOX4 contribute to ACh-induced dilation in human arterioles from patients without coronary artery disease. NOX4 increases TRPV4 phosphorylation in endothelial cells, which in turn enhances TRPV4-mediated Ca2+ entry and subsequent endothelium-dependent dilation in human arterioles.
Collapse
Affiliation(s)
- Yangjing Xie
- School of Basic Medical Sciences, Anhui Medical University, 81 Meishan Road, Hefei 230032, China.,Department of Cardiology, The First Affiliated Hospital of Anhui Medical University, Hefei, China.,Cardiovascular Center, Department of Medicine, Medical College of Wisconsin, Milwaukee, WI, USA.,Biopharmaceutical Institute, Anhui Medical University, 81 Meishan Road, Hefei 230032, China
| | - Yoshinori Nishijima
- Cardiovascular Center, Department of Medicine, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Natalya S. Zinkevich
- Cardiovascular Center, Department of Medicine, Medical College of Wisconsin, Milwaukee, WI, USA.,Department of Biology, College of Liberal Arts and Sciences, University of Illinois at Springfield, Springfield, IL, USA
| | - Ankush Korishettar
- Cardiovascular Center, Department of Medicine, Medical College of Wisconsin, Milwaukee, WI, USA.,Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Juan Fang
- Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI, USA.,Children’s Research Institute, Children’s Wisconsin, Milwaukee, WI, USA
| | - Angela J. Mathison
- Bioinformatics Research and Development Laboratory, Genomic Sciences and Precision Medicine Center (GSPMC), Department of Surgery, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Michael T. Zimmermann
- Bioinformatics Research and Development Laboratory, Genomic Sciences and Precision Medicine Center (GSPMC), Department of Surgery, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - David A. Wilcox
- Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI, USA.,Children’s Research Institute, Children’s Wisconsin, Milwaukee, WI, USA
| | - David D. Gutterman
- Cardiovascular Center, Department of Medicine, Medical College of Wisconsin, Milwaukee, WI, USA.,Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Yuxian Shen
- School of Basic Medical Sciences, Anhui Medical University, 81 Meishan Road, Hefei 230032, China.,Biopharmaceutical Institute, Anhui Medical University, 81 Meishan Road, Hefei 230032, China.,Article correspondence to: David X. Zhang, Ph.D., Department of Medicine, Cardiovascular Center, Medical College of Wisconsin, 8701 Watertown Plank Rd, Milwaukee, WI, 53226, USA, Tel: (414) 955-5633, Fax: (414) 955-6572, And Yuxian Shen, Ph.D., School of Basic Medical Sciences and Biopharmaceutical Institute, Anhui Medical University, 81 Meishan Road, Hefei 230032, China, Tel: +86-551-6511-3776,
| | - David X. Zhang
- Cardiovascular Center, Department of Medicine, Medical College of Wisconsin, Milwaukee, WI, USA.,Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, WI, USA.,Article correspondence to: David X. Zhang, Ph.D., Department of Medicine, Cardiovascular Center, Medical College of Wisconsin, 8701 Watertown Plank Rd, Milwaukee, WI, 53226, USA, Tel: (414) 955-5633, Fax: (414) 955-6572, And Yuxian Shen, Ph.D., School of Basic Medical Sciences and Biopharmaceutical Institute, Anhui Medical University, 81 Meishan Road, Hefei 230032, China, Tel: +86-551-6511-3776,
| |
Collapse
|
6
|
VanAntwerp IR, Phelps LE, Peuler JD, Kopf PG. Effects of trans- versus cis-resveratrol on adrenergic contractions of the rat tail artery and role of endothelium. Physiol Rep 2020; 8:e14666. [PMID: 33369273 PMCID: PMC7758980 DOI: 10.14814/phy2.14666] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 10/26/2020] [Accepted: 11/11/2020] [Indexed: 11/30/2022] Open
Abstract
The health benefits of the natural polyphenol trans‐resveratrol may play an important role in preventing a variety of diseases. Resveratrol has been shown to reduce blood pressure and improve metabolic diseases such as type 2 diabetes mellitus and obesity. Our previous studies examined the role of K+ channels in the vasorelaxation responses to trans‐resveratrol in the rat tail artery. During these studies, we uncovered a novel transient contraction prior to the sustained relaxation effect of trans‐resveratrol. Thus, the purpose of this study was to determine the role of the endothelium in these vascular contraction and relaxation responses to trans‐resveratrol. We additionally sought to determine if the cis‐isomer of resveratrol exerts any of the same vascular effects as the trans‐isomer. The vascular responses to trans‐resveratrol were examined in rat tail arteries with intact or denuded endothelium over a 2‐hr period. Additionally, the vascular responses to trans‐ and cis‐resveratrol were compared in rat tail arteries with intact endothelium. Both the transient contractile response and the persistent relaxation response to trans‐resveratrol were similar in the arterial rings with intact or denuded endothelium. There was a significant correlation between the initial contraction‐enhancing action of trans‐resveratrol and the magnitude of the sustained relaxation for vessels with both intact and denuded endothelium. Moreover, we demonstrated that cis‐resveratrol produced a significantly greater relaxation response as compared to trans‐resveratrol without the initial contractile response. These data demonstrate the role of the vascular smooth muscle in the vascular responses to resveratrol and the potential clinical benefits of the cis‐isomer of resveratrol as compared to the trans‐isomer.
Collapse
Affiliation(s)
- Ian R VanAntwerp
- Department of Pharmacology, Midwestern University, Downers Grove, IL, USA
| | - Laura E Phelps
- Department of Pharmacology, Midwestern University, Downers Grove, IL, USA
| | - Jacob D Peuler
- Department of Pharmacology, Midwestern University, Downers Grove, IL, USA
| | - Phillip G Kopf
- Department of Pharmacology, Midwestern University, Downers Grove, IL, USA
| |
Collapse
|
7
|
Lemmey HAL, Garland CJ, Dora KA. Intrinsic regulation of microvascular tone by myoendothelial feedback circuits. CURRENT TOPICS IN MEMBRANES 2020; 85:327-355. [PMID: 32402644 DOI: 10.1016/bs.ctm.2020.01.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The endothelium is an important regulator of arterial vascular tone, acting to release nitric oxide (NO) and open Ca2+-activated K+ (KCa) channels to relax vascular smooth muscle cells (VSMCs). While agonists acting at endothelial cell (EC) receptors are widely used to assess the ability of the endothelium to reduce vascular tone, the intrinsic EC-dependent mechanisms are less well characterized. In small resistance arteries and arterioles, the presence of heterocellular gap junctions termed myoendothelial gap junctions (MEGJs) allows the passage of not only current, but small molecules including Ca2+ and inositol trisphosphate (IP3). When stimulated to contract, the increase in VSM Ca2+ and IP3 can therefore potentially pass through MEGJs to activate adjacent ECs. This activation releases NO and opens KCa channels, which act to limit contraction. This myoendothelial feedback (MEF) is amplified by EC Ca2+ influx and release pathways, and is dynamically modulated by processes regulating gap junction conductance. There is a remarkable localization of key signaling and regulatory proteins within the EC projection toward VSM, and the intrinsic EC-dependent signaling pathways occurring with this highly specialized microdomain are reviewed.
Collapse
Affiliation(s)
- Hamish A L Lemmey
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
| | | | - Kim A Dora
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom.
| |
Collapse
|
8
|
Tsibulnikov SY, Maslov LN, Gorbunov AS, Voronkov NS, Boshchenko AA, Popov SV, Prokudina ES, Singh N, Downey JM. A Review of Humoral Factors in Remote Preconditioning of the Heart. J Cardiovasc Pharmacol Ther 2019; 24:403-421. [PMID: 31035796 DOI: 10.1177/1074248419841632] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
A humoral mechanism of cardioprotection by remote ischemic preconditioning (RIP) has been clearly demonstrated in various models of ischemia-reperfusion including upper and lower extremities, liver, and the mesenteric and renal arteries. A wide range of humoral factors for RIP have been proposed including hydrophobic peptides, opioid peptides, adenosine, prostanoids, endovanilloids, endocannabinoids, calcitonin gene-related peptide, leukotrienes, noradrenaline, adrenomedullin, erythropoietin, apolipoprotein, A-I glucagon-like peptide-1, interleukin 10, stromal cell-derived factor 1, and microRNAs. Virtually, all of the components of ischemic preconditioning's signaling pathway such as nitric oxide synthase, protein kinase C, redox signaling, PI3-kinase/Akt, glycogen synthase kinase β, ERK1/2, mitoKATP channels, Connexin 43, and STAT were all found to play a role. The signaling pattern also depends on which remote vascular bed was subjected to ischemia and on the time between applying the rip and myocardial ischemia occurs. Because there is convincing evidence for many seemingly diverse humoral components in RIP, the most likely explanation is that the overall mechanism is complex like that seen in ischemic preconditioning where multiple components are both in series and in parallel and interact with each other. Inhibition of any single component in the right circumstance may block the resulting protective effect, and selectively activating that component may trigger the protection. Identifying the humoral factors responsible for RIP might be useful in developing drugs that confer RIP's protection in a more comfortable and reliable manner.
Collapse
Affiliation(s)
- Sergey Y Tsibulnikov
- 1 Cardiology Research Institute, Tomsk National Research Medical Center of the Russian Academy of Science, Tomsk, Russia
| | - Leonid N Maslov
- 1 Cardiology Research Institute, Tomsk National Research Medical Center of the Russian Academy of Science, Tomsk, Russia
| | - Alexander S Gorbunov
- 1 Cardiology Research Institute, Tomsk National Research Medical Center of the Russian Academy of Science, Tomsk, Russia
| | - Nikita S Voronkov
- 1 Cardiology Research Institute, Tomsk National Research Medical Center of the Russian Academy of Science, Tomsk, Russia
| | - Alla A Boshchenko
- 1 Cardiology Research Institute, Tomsk National Research Medical Center of the Russian Academy of Science, Tomsk, Russia
| | - Sergey V Popov
- 1 Cardiology Research Institute, Tomsk National Research Medical Center of the Russian Academy of Science, Tomsk, Russia
| | - Ekaterina S Prokudina
- 1 Cardiology Research Institute, Tomsk National Research Medical Center of the Russian Academy of Science, Tomsk, Russia
| | - Nirmal Singh
- 2 Department of Pharmaceutical Sciences and Drug Research, Punjabi University, Patiala, India
| | - James M Downey
- 3 Department of Physiology and Cell Biology, College of Medicine, University of South Alabama, Mobile, AL, USA
| |
Collapse
|
9
|
Yang H, Xue Y, Kuang S, Zhang M, Chen J, Liu L, Shan Z, Lin Q, Li X, Yang M, Zhou H, Rao F, Deng C. Involvement of Orai1 in tunicamycin-induced endothelial dysfunction. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2019; 23:95-102. [PMID: 30820153 PMCID: PMC6384200 DOI: 10.4196/kjpp.2019.23.2.95] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/13/2018] [Revised: 09/04/2018] [Accepted: 10/10/2018] [Indexed: 12/28/2022]
Abstract
Endoplasmic reticulum (ER) stress is mediated by disturbance of Ca2+ homeostasis. The store-operated calcium (SOC) channel is the primary Ca2+ channel in non-excitable cells, but its participation in agent-induced ER stress is not clear. In this study, the effects of tunicamycin on Ca2+ influx in human umbilical vein endothelial cells (HUVECs) were observed with the fluorescent probe Fluo-4 AM. The effect of tunicamycin on the expression of the unfolded protein response (UPR)-related proteins BiP and CHOP was assayed by western blotting with or without inhibition of Orai1. Tunicamycin induced endothelial dysfunction by activating ER stress. Orai1 expression and the influx of extracellular Ca2+ in HUVECs were both upregulated during ER stress. The SOC channel inhibitor SKF96365 reversed tunicamycin-induced endothelial cell dysfunction by inhibiting ER stress. Regulation of tunicamycin-induced ER stress by Orai1 indicates that modification of Orai1 activity may have therapeutic value for conditions with ER stress-induced endothelial dysfunction.
Collapse
Affiliation(s)
- Hui Yang
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong Provincial Key Laboratory of Clinical Pharmacology, Guangzhou, Guangdong 510080, China.,Research Center of Medical Sciences, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, China
| | - Yumei Xue
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong Provincial Key Laboratory of Clinical Pharmacology, Guangzhou, Guangdong 510080, China.,Research Center of Medical Sciences, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, China
| | - Sujuan Kuang
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong Provincial Key Laboratory of Clinical Pharmacology, Guangzhou, Guangdong 510080, China.,Research Center of Medical Sciences, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, China
| | - Mengzhen Zhang
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong Provincial Key Laboratory of Clinical Pharmacology, Guangzhou, Guangdong 510080, China.,Research Center of Medical Sciences, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, China
| | - Jinghui Chen
- Department of Anesthesiology, Guangzhou Women and Children's Medical Center, Guangzhou, Guangdong 510623, China
| | - Lin Liu
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong Provincial Key Laboratory of Clinical Pharmacology, Guangzhou, Guangdong 510080, China.,Research Center of Medical Sciences, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, China
| | - Zhixin Shan
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong Provincial Key Laboratory of Clinical Pharmacology, Guangzhou, Guangdong 510080, China.,Research Center of Medical Sciences, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, China
| | - Qiuxiong Lin
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong Provincial Key Laboratory of Clinical Pharmacology, Guangzhou, Guangdong 510080, China.,Research Center of Medical Sciences, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, China
| | - Xiaohong Li
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong Provincial Key Laboratory of Clinical Pharmacology, Guangzhou, Guangdong 510080, China.,Research Center of Medical Sciences, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, China
| | - Min Yang
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong Provincial Key Laboratory of Clinical Pharmacology, Guangzhou, Guangdong 510080, China.,Research Center of Medical Sciences, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, China
| | - Hui Zhou
- Department of Pharmacy, Guangzhou Panyu Shiqiao Hospital, Guangzhou, Guangdong 511400, China
| | - Fang Rao
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong Provincial Key Laboratory of Clinical Pharmacology, Guangzhou, Guangdong 510080, China.,Research Center of Medical Sciences, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, China
| | - Chunyu Deng
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong Provincial Key Laboratory of Clinical Pharmacology, Guangzhou, Guangdong 510080, China.,Research Center of Medical Sciences, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, China
| |
Collapse
|
10
|
Kapela A, Behringer EJ, Segal SS, Tsoukias NM. Biophysical properties of microvascular endothelium: Requirements for initiating and conducting electrical signals. Microcirculation 2018; 25. [PMID: 29117630 DOI: 10.1111/micc.12429] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2017] [Accepted: 11/02/2017] [Indexed: 12/24/2022]
Abstract
OBJECTIVE Electrical signaling along the endothelium underlies spreading vasodilation and blood flow control. We use mathematical modeling to determine the electrical properties of the endothelium and gain insight into the biophysical determinants of electrical conduction. METHODS Electrical conduction data along endothelial tubes (40 μm wide, 2.5 mm long) isolated from mouse skeletal muscle resistance arteries were analyzed using cable equations and a multicellular computational model. RESULTS Responses to intracellular current injection attenuate with an axial length constant (λ) of 1.2-1.4 mm. Data were fitted to estimate the axial (ra ; 10.7 MΩ/mm) and membrane (rm ; 14.5 MΩ∙mm) resistivities, EC membrane resistance (Rm ; 12 GΩ), and EC-EC coupling resistance (Rgj ; 4.5 MΩ) and predict that stimulation of ≥30 neighboring ECs is required to elicit 1 mV of hyperpolarization at distance = 2.5 mm. Opening Ca2+ -activated K+ channels (KCa ) along the endothelium reduced λ by up to 55%. CONCLUSIONS High Rm makes the endothelium sensitive to electrical stimuli and able to conduct these signals effectively. Whereas the activation of a group of ECs is required to initiate physiologically relevant hyperpolarization, this requirement is increased by myoendothelial coupling and KCa activation along the endothelium inhibits conduction by dissipating electrical signals.
Collapse
Affiliation(s)
- Adam Kapela
- Department of Biomedical Engineering, Florida International University, Miami, FL, USA
| | - Erik J Behringer
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO, USA.,Department of Basic Sciences, Loma Linda University, Loma Linda, CA, USA
| | - Steven S Segal
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO, USA.,Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO, USA
| | - Nikolaos M Tsoukias
- Department of Biomedical Engineering, Florida International University, Miami, FL, USA.,School of Chemical Engineering, National Technical University of Athens, Athens, Greece
| |
Collapse
|
11
|
Cipolla MJ, Liebeskind DS, Chan SL. The importance of comorbidities in ischemic stroke: Impact of hypertension on the cerebral circulation. J Cereb Blood Flow Metab 2018; 38:2129-2149. [PMID: 30198826 PMCID: PMC6282213 DOI: 10.1177/0271678x18800589] [Citation(s) in RCA: 227] [Impact Index Per Article: 32.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Comorbidities are a hallmark of stroke that both increase the incidence of stroke and worsen outcome. Hypertension is prevalent in the stroke population and the most important modifiable risk factor for stroke. Hypertensive disorders promote stroke through increased shear stress, endothelial dysfunction, and large artery stiffness that transmits pulsatile flow to the cerebral microcirculation. Hypertension also promotes cerebral small vessel disease through several mechanisms, including hypoperfusion, diminished autoregulatory capacity and localized increase in blood-brain barrier permeability. Preeclampsia, a hypertensive disorder of pregnancy, also increases the risk of stroke 4-5-fold compared to normal pregnancy that predisposes women to early-onset cognitive impairment. In this review, we highlight how comorbidities and concomitant disorders are not only risk factors for ischemic stroke, but alter the response to acute ischemia. We focus on hypertension as a comorbidity and its effects on the cerebral circulation that alters the pathophysiology of ischemic stroke and should be considered in guiding future therapeutic strategies.
Collapse
Affiliation(s)
- Marilyn J Cipolla
- 1 Department of Neurological Sciences, University of Vermont Larner College of Medicine, Burlington, VT, USA
| | - David S Liebeskind
- 2 Neurovascular Imaging Research Core and Stroke Center, Department of Neurology, University of California at Los Angeles, Los Angeles, CA, USA
| | - Siu-Lung Chan
- 1 Department of Neurological Sciences, University of Vermont Larner College of Medicine, Burlington, VT, USA
| |
Collapse
|
12
|
Jackson WF. Boosting the signal: Endothelial inward rectifier K + channels. Microcirculation 2018; 24. [PMID: 27652592 DOI: 10.1111/micc.12319] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 09/12/2016] [Indexed: 12/19/2022]
Abstract
Endothelial cells express a diverse array of ion channels including members of the strong inward rectifier family composed of KIR 2 subunits. These two-membrane spanning domain channels are modulated by their lipid environment, and exist in macromolecular signaling complexes with receptors, protein kinases and other ion channels. Inward rectifier K+ channel (KIR ) currents display a region of negative slope conductance at membrane potentials positive to the K+ equilibrium potential that allows outward current through the channels to be activated by membrane hyperpolarization, permitting KIR to amplify hyperpolarization induced by other K+ channels and ion transporters. Increases in extracellular K+ concentration activate KIR allowing them to sense extracellular K+ concentration and transduce this change into membrane hyperpolarization. These properties position KIR to participate in the mechanism of action of hyperpolarizing vasodilators and contribute to cell-cell conduction of hyperpolarization along the wall of microvessels. The expression of KIR in capillaries in electrically active tissues may allow KIR to sense extracellular K+ , contributing to functional hyperemia. Understanding the regulation of expression and function of microvascular endothelial KIR will improve our understanding of the control of blood flow in the microcirculation in health and disease and may provide new targets for the development of therapeutics in the future.
Collapse
Affiliation(s)
- William F Jackson
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, USA
| |
Collapse
|
13
|
Salomonsson M, Brasen JC, Sorensen CM. Role of renal vascular potassium channels in physiology and pathophysiology. Acta Physiol (Oxf) 2017; 221:14-31. [PMID: 28371470 DOI: 10.1111/apha.12882] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Revised: 05/10/2016] [Accepted: 03/22/2017] [Indexed: 12/31/2022]
Abstract
The control of renal vascular tone is important for the regulation of salt and water balance, blood pressure and the protection against damaging elevated glomerular pressure. The K+ conductance is a major factor in the regulation of the membrane potential (Vm ) in vascular smooth muscle (VSMC) and endothelial cells (EC). The vascular tone is controlled by Vm via its effect on the opening probability of voltage-operated Ca2+ channels (VOCC) in VSMC. When K+ conductance increases Vm becomes more negative and vasodilation follows, while deactivation of K+ channels leads to depolarization and vasoconstriction. K+ channels in EC indirectly participate in the control of vascular tone by endothelium-derived vasodilation. Therefore, by regulating the tone of renal resistance vessels, K+ channels have a potential role in the control of fluid homoeostasis and blood pressure as well as in the protection of the renal parenchyma. The main classes of K+ channels (calcium activated (KCa ), inward rectifier (Kir ), voltage activated (Kv ) and ATP sensitive (KATP )) have been found in the renal vessels. In this review, we summarize results available in the literature and our own studies in the field. We compare the ambiguous in vitro and in vivo results. We discuss the role of single types of K+ channels and the integrated function of several classes. We also deal with the possible role of renal vascular K+ channels in the pathophysiology of hypertension, diabetes mellitus and sepsis.
Collapse
Affiliation(s)
| | - J. C. Brasen
- Department of Electrical Engineering; Technical University of Denmark; Kgs. Lyngby Denmark
| | - C. M. Sorensen
- Department of Biomedical Sciences; Division of Renal and Vascular Physiology; University of Copenhagen; Copenhagen Denmark
| |
Collapse
|
14
|
Stom SM, Phelps LE, Peuler JD. Resveratrol can both enhance and relax adrenergic contractions of the rat tail artery. J Smooth Muscle Res 2016; 52:18-35. [PMID: 26936000 PMCID: PMC5137260 DOI: 10.1540/jsmr.52.18] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Our aims were to determine 1) if resveratrol's vasorelaxant action is greater in the
distal (resistance) versus proximal (conductance) portion of the rat tail artery, and 2)
if it can be blocked by agents known to block different potassium (K) channels in arterial
smooth muscle. We found that its half-maximally effective concentration values were
essentially identical (25 ± 3 versus 27 ± 3 μM) for relaxing adrenergically-precontracted
rings prepared from distal versus proximal tissues. This does not confirm a previous
report of greater relaxation in resistance versus conductance arteries. We also found that
its relaxation could not be blocked by any of seven different K channel blockers. However,
we uncovered a novel unanticipated action not yet reported. In half our arterial ring
preparations, resveratrol transiently enhanced adrenergically-induced precontractions
beginning well before its sustained relaxant effect became apparent. This action provides
the first reasonable explanation for previously unexplained increases in arterial
pressures observed during acute intravenous administration of resveratrol to animal models
of traumatic ischemic tissue injury, in which hypotension is often present and in need of
correction. Also unanticipated, this same transient enhancement of adrenergic contraction
was notably inhibited by some of the same K channel blockers (particularly
tetraethylammonium and glibenclamide) that failed to influence its relaxant effect.
Although we do not rule out smooth muscle as a possible site for such a paradoxical
finding, we suspect resveratrol could also be acting on K-selective mechano-sensitive ion
channels located in the endothelium where they may participate in release of contracting
factors.
Collapse
Affiliation(s)
- Sayra M Stom
- Pharmacology Department, Midwestern University, Downers Grove, IL 60515, USA
| | | | | |
Collapse
|
15
|
Calycosin and Formononetin Induce Endothelium-Dependent Vasodilation by the Activation of Large-Conductance Ca 2+-Activated K + Channels (BK Ca). EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2016; 2016:5272531. [PMID: 27994632 PMCID: PMC5141325 DOI: 10.1155/2016/5272531] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 09/26/2016] [Accepted: 10/19/2016] [Indexed: 12/13/2022]
Abstract
Calycosin and formononetin are two structurally similar isoflavonoids that have been shown to induce vasodilation in aorta and conduit arteries, but study of their actions on endothelial functions is lacking. Here, we demonstrated that both isoflavonoids relaxed rat mesenteric resistance arteries in a concentration-dependent manner, which was reduced by endothelial disruption and nitric oxide synthase (NOS) inhibition, indicating the involvement of both endothelium and vascular smooth muscle. In addition, the endothelium-dependent vasodilation, but not the endothelium-independent vasodilation, was blocked by BKCa inhibitor iberiotoxin (IbTX). Using human umbilical vein endothelial cells (HUVECs) as a model, we showed calycosin and formononetin induced dose-dependent outwardly rectifying K+ currents using whole cell patch clamp. These currents were blocked by tetraethylammonium chloride (TEACl), charybdotoxin (ChTX), or IbTX, but not apamin. We further demonstrated that both isoflavonoids significantly increased nitric oxide (NO) production and upregulated the activities and expressions of endothelial NOS (eNOS) and neuronal NOS (nNOS). These results suggested that calycosin and formononetin act as endothelial BKCa activators for mediating endothelium-dependent vasodilation through enhancing endothelium hyperpolarization and NO production. Since activation of BKCa plays a role in improving behavioral and cognitive disorders, we suggested that these two isoflavonoids could provide beneficial effects to cognitive disorders through vascular regulation.
Collapse
|
16
|
Randhawa PK, Jaggi AS. Gadolinium and ruthenium red attenuate remote hind limb preconditioning-induced cardioprotection: possible role of TRP and especially TRPV channels. Naunyn Schmiedebergs Arch Pharmacol 2016; 389:887-96. [PMID: 27118661 DOI: 10.1007/s00210-016-1251-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 04/20/2016] [Indexed: 01/16/2023]
Abstract
Remote ischemic preconditioning is a well reported therapeutic strategy that induces cardioprotective effects but the underlying intracellular mechanisms have not been widely explored. The current study was designed to investigate the involvement of TRP and especially TRPV channels in remote hind limb preconditioning-induced cardioprotection. Remote hind limb preconditioning stimulus (4 alternate cycles of inflation and deflation of 5 min each) was delivered using a blood pressure cuff tied on the hind limb of the anesthetized rat. Using Langendorff's system, the heart was perfused and subjected to 30-min ischemia and 120-min reperfusion. The myocardial injury was assessed by measuring infarct size, lactate dehydrogenase (LDH), creatine kinase (CK), LVDP, +dp/dtmax, -dp/dtmin, heart rate, and coronary flow rate. Gadolinium, TRP blocker, and ruthenium red, TRPV channel blocker, were employed as pharmacological tools. Remote hind limb preconditioning significantly reduced the infarct size, LDH release, CK release and improved coronary flow rate, hemodynamic parameters including LVDP, +dp/dtmax, -dp/dtmin, and heart rate. However, gadolinium (7.5 and 15 mg kg(-1)) and ruthenium red (4 and 8 mg kg(-1)) significantly attenuated the cardioprotective effects suggesting the involvement of TRP especially TRPV channels in mediating remote hind limb preconditioning-induced cardioprotection. Remote hind limb preconditioning stimulus possibly activates TRPV channels on the heart or sensory nerve fibers innervating the heart to induce cardioprotective effects. Alternatively, remote hind limb preconditioning stimulus may also activate the mechanosensitive TRP and especially TRPV channels on the sensory nerve fibers innervating the skeletal muscles to trigger cardioprotective neurogenic signaling cascade. The cardioprotective effects of remote hind limb preconditioning may be mediated via activation of mechanosensitive TRP and especially TRPV channels.
Collapse
Affiliation(s)
- Puneet Kaur Randhawa
- Department of Pharmaceutical Sciences and Drug Research, Punjabi University, Patiala, 147002, India
| | - Amteshwar Singh Jaggi
- Department of Pharmaceutical Sciences and Drug Research, Punjabi University, Patiala, 147002, India.
| |
Collapse
|
17
|
Abstract
KATP channels are integral to the functions of many cells and tissues. The use of electrophysiological methods has allowed for a detailed characterization of KATP channels in terms of their biophysical properties, nucleotide sensitivities, and modification by pharmacological compounds. However, even though they were first described almost 25 years ago (Noma 1983, Trube and Hescheler 1984), the physiological and pathophysiological roles of these channels, and their regulation by complex biological systems, are only now emerging for many tissues. Even in tissues where their roles have been best defined, there are still many unanswered questions. This review aims to summarize the properties, molecular composition, and pharmacology of KATP channels in various cardiovascular components (atria, specialized conduction system, ventricles, smooth muscle, endothelium, and mitochondria). We will summarize the lessons learned from available genetic mouse models and address the known roles of KATP channels in cardiovascular pathologies and how genetic variation in KATP channel genes contribute to human disease.
Collapse
Affiliation(s)
- Monique N Foster
- Departments of Pediatrics, Physiology & Neuroscience, and Biochemistry and Molecular Pharmacology, NYU School of Medicine, New York, New York
| | - William A Coetzee
- Departments of Pediatrics, Physiology & Neuroscience, and Biochemistry and Molecular Pharmacology, NYU School of Medicine, New York, New York
| |
Collapse
|
18
|
Hald BO, Welsh DG, Holstein-Rathlou NH, Jacobsen JCB. Gap junctions suppress electrical but not [Ca(2+)] heterogeneity in resistance arteries. Biophys J 2015; 107:2467-76. [PMID: 25418315 DOI: 10.1016/j.bpj.2014.09.036] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Revised: 09/03/2014] [Accepted: 09/30/2014] [Indexed: 01/03/2023] Open
Abstract
Despite stochastic variation in the molecular composition and morphology of individual smooth muscle and endothelial cells, the membrane potential along intact microvessels is remarkably uniform. This is crucial for coordinated vasomotor responses. To investigate how this electrical homogeneity arises, a virtual arteriole was developed that introduces variation in the activities of ion-transport proteins between cells. By varying the level of heterogeneity and subpopulations of gap junctions (GJs), the resulting simulations shows that GJs suppress electrical variation but can only reduce cytosolic [Ca(2+)] variation. The process of electrical smoothing, however, introduces an energetic cost due to permanent currents, one which is proportional to the level of heterogeneity. This cost is particularly large when electrochemically different endothelial-cell and smooth-muscle-cell layers are coupled. Collectively, we show that homocellular GJs in a passively open state are crucial for electrical uniformity within the given cell layer, but homogenization may be limited by biophysical or energetic constraints. Owing to the ubiquitous presence of ion transport-proteins and cell-cell heterogeneity in biological tissues, these findings generalize across most biological fields.
Collapse
Affiliation(s)
- Bjørn Olav Hald
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark.
| | - Donald G Welsh
- Department of Physiology & Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | | | | |
Collapse
|
19
|
Veit F, Pak O, Brandes RP, Weissmann N. Hypoxia-dependent reactive oxygen species signaling in the pulmonary circulation: focus on ion channels. Antioxid Redox Signal 2015; 22:537-52. [PMID: 25545236 PMCID: PMC4322788 DOI: 10.1089/ars.2014.6234] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
SIGNIFICANCE An acute lack of oxygen in the lung causes hypoxic pulmonary vasoconstriction, which optimizes gas exchange. In contrast, chronic hypoxia triggers a pathological vascular remodeling causing pulmonary hypertension, and ischemia can cause vascular damage culminating in lung edema. RECENT ADVANCES Regulation of ion channel expression and gating by cellular redox state is a widely accepted mechanism; however, it remains a matter of debate whether an increase or a decrease in reactive oxygen species (ROS) occurs under hypoxic conditions. Ion channel redox regulation has been described in detail for some ion channels, such as Kv channels or TRPC6. However, in general, information on ion channel redox regulation remains scant. CRITICAL ISSUES AND FUTURE DIRECTIONS In addition to the debate of increased versus decreased ROS production during hypoxia, we aim here at describing and deciphering why different oxidants, under different conditions, can cause both activation and inhibition of channel activity. While the upstream pathways affecting channel gating are often well described, we need a better understanding of redox protein modifications to be able to determine the complexity of ion channel redox regulation. Against this background, we summarize the current knowledge on hypoxia-induced ROS-mediated ion channel signaling in the pulmonary circulation.
Collapse
Affiliation(s)
- Florian Veit
- 1 Excellence Cluster Cardiopulmonary System (ECCPS), Universities of Giessen and Marburg Lung Center (UGMLC), German Center for Lung Research (DZL) , Giessen, Germany
| | | | | | | |
Collapse
|
20
|
Wragg JW, Durant S, McGettrick HM, Sample KM, Egginton S, Bicknell R. Shear stress regulated gene expression and angiogenesis in vascular endothelium. Microcirculation 2015; 21:290-300. [PMID: 24471792 DOI: 10.1111/micc.12119] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Accepted: 01/22/2014] [Indexed: 01/13/2023]
Abstract
The behavior of vascular EC is greatly altered in sites of pathological angiogenesis, such as a developing tumor or atherosclerotic plaque. Until recently it was thought that this was largely due to abnormal chemical signaling, i.e., endothelial cell chemo transduction, at these sites. However, we now demonstrate that the shear stress intensity encountered by EC can have a profound impact on their gene expression and behavior. We review the growing body of evidence suggesting that mechanotransduction, too, is a major regulator of pathological angiogenesis. This fits with the evolving story of physiological angiogenesis, where a combination of metabolic and mechanical signaling is emerging as the probable mechanism by which tight feedback regulation of angiogenesis is achieved in vivo.
Collapse
Affiliation(s)
- Joseph W Wragg
- Angiogenesis Group, Centre for Cardiovascular Sciences, Institute for Biomedical Research, Schools of Immunity and Infection and Cancer Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | | | | | | | | | | |
Collapse
|
21
|
Dubey M, Bugiani M, Ridder MC, Postma NL, Brouwers E, Polder E, Jacobs JG, Baayen JC, Klooster J, Kamermans M, Aardse R, de Kock CPJ, Dekker MP, van Weering JRT, Heine VM, Abbink TEM, Scheper GC, Boor I, Lodder JC, Mansvelder HD, van der Knaap MS. Mice with megalencephalic leukoencephalopathy with cysts: A developmental angle. Ann Neurol 2014; 77:114-31. [DOI: 10.1002/ana.24307] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Revised: 10/27/2014] [Accepted: 11/02/2014] [Indexed: 11/11/2022]
Affiliation(s)
- Mohit Dubey
- Department of Pediatrics/Child Neurology; Neuroscience Campus Amsterdam, VU University Medical Center
- Department of Integrative Neurophysiology; Center for Neurogenomics and Cognitive Research, VU University
| | - Marianna Bugiani
- Department of Pediatrics/Child Neurology; Neuroscience Campus Amsterdam, VU University Medical Center
- Department of Pathology; VU University Medical Center
| | - Margreet C. Ridder
- Department of Pediatrics/Child Neurology; Neuroscience Campus Amsterdam, VU University Medical Center
| | - Nienke L. Postma
- Department of Pediatrics/Child Neurology; Neuroscience Campus Amsterdam, VU University Medical Center
| | - Eelke Brouwers
- Department of Pediatrics/Child Neurology; Neuroscience Campus Amsterdam, VU University Medical Center
- Department of Integrative Neurophysiology; Center for Neurogenomics and Cognitive Research, VU University
| | - Emiel Polder
- Department of Pediatrics/Child Neurology; Neuroscience Campus Amsterdam, VU University Medical Center
| | - J. Gerbren Jacobs
- Department of Pediatrics/Child Neurology; Neuroscience Campus Amsterdam, VU University Medical Center
- Department of Functional Genomics; Center for Neurogenomics and Cognitive Research, VU University
| | | | - Jan Klooster
- Department of Retinal Signal Processing; Netherlands Institute for Neuroscience-KNAW; Amsterdam Netherlands
| | - Maarten Kamermans
- Department of Retinal Signal Processing; Netherlands Institute for Neuroscience-KNAW; Amsterdam Netherlands
| | - Romy Aardse
- Department of Integrative Neurophysiology; Center for Neurogenomics and Cognitive Research, VU University
| | - Christiaan P. J. de Kock
- Department of Integrative Neurophysiology; Center for Neurogenomics and Cognitive Research, VU University
| | - Marien P. Dekker
- Department of Functional Genomics; Center for Neurogenomics and Cognitive Research, VU University
| | - Jan R. T. van Weering
- Department of Functional Genomics; Center for Neurogenomics and Cognitive Research, VU University
| | - Vivi M. Heine
- Department of Pediatrics/Child Neurology; Neuroscience Campus Amsterdam, VU University Medical Center
- Department of Functional Genomics; Center for Neurogenomics and Cognitive Research, VU University
| | - Truus E. M. Abbink
- Department of Pediatrics/Child Neurology; Neuroscience Campus Amsterdam, VU University Medical Center
| | - Gert C. Scheper
- Department of Pediatrics/Child Neurology; Neuroscience Campus Amsterdam, VU University Medical Center
| | - Ilja Boor
- Department of Pediatrics/Child Neurology; Neuroscience Campus Amsterdam, VU University Medical Center
| | - Johannes C. Lodder
- Department of Integrative Neurophysiology; Center for Neurogenomics and Cognitive Research, VU University
| | - Huibert D. Mansvelder
- Department of Integrative Neurophysiology; Center for Neurogenomics and Cognitive Research, VU University
| | - Marjo S. van der Knaap
- Department of Pediatrics/Child Neurology; Neuroscience Campus Amsterdam, VU University Medical Center
- Department of Functional Genomics; Center for Neurogenomics and Cognitive Research, VU University
| |
Collapse
|
22
|
Origins of variation in conducted vasomotor responses. Pflugers Arch 2014; 467:2055-67. [PMID: 25420525 DOI: 10.1007/s00424-014-1649-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Revised: 10/09/2014] [Accepted: 11/07/2014] [Indexed: 10/24/2022]
Abstract
Regulation of blood flow in the microcirculation depends on synchronized vasomotor responses. The vascular conducted response is a synchronous dilatation or constriction, elicited by a local electrical event that spreads along the vessel wall. Despite the underlying electrical nature, however, the efficacy of conducted responses varies significantly between different initiating stimuli within the same vascular bed as well as between different vascular beds following the same stimulus. The differences have stimulated proposals of different mechanisms to account for the experimentally observed variation. Using a computational approach that allows for introduction of structural and electrophysiological heterogeneity, we systematically tested variations in both arteriolar electrophysiology and modes of stimuli. Within the same vessel, our simulations show that conduction efficacy is influenced by the type of cell being stimulated and, in case of depolarization, by the stimulation strength. Particularly, simultaneous stimulation of both endothelial and vascular smooth muscle cells augments conduction. Between vessels, the specific electrophysiology determines membrane resistance and conduction efficiency-notably depolarization or radial currents reduce electrical spread. Random cell-cell variation, ubiquitous in biological systems, only cause small or no reduction in conduction efficiency. Collectively, our simulations can explain why CVRs from hyperpolarizing stimuli tend to conduct longer than CVRs from depolarizing stimuli and why agonists like acetylcholine induce CVRs that tend to conduct longer than electrical injections. The findings demonstrate that although substantial heterogeneity is observed in conducted responses, it can be largely ascribed to the origin of electrical stimulus combined with the specific electrophysiological properties of the arteriole. We conclude by outlining a set of "principles of electrical conduction" in the microcirculation.
Collapse
|
23
|
Pugliese SC, Poth JM, Fini MA, Olschewski A, El Kasmi KC, Stenmark KR. The role of inflammation in hypoxic pulmonary hypertension: from cellular mechanisms to clinical phenotypes. Am J Physiol Lung Cell Mol Physiol 2014; 308:L229-52. [PMID: 25416383 DOI: 10.1152/ajplung.00238.2014] [Citation(s) in RCA: 157] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Hypoxic pulmonary hypertension (PH) comprises a heterogeneous group of diseases sharing the common feature of chronic hypoxia-induced pulmonary vascular remodeling. The disease is usually characterized by mild to moderate pulmonary vascular remodeling that is largely thought to be reversible compared with the progressive irreversible disease seen in World Health Organization (WHO) group I disease. However, in these patients, the presence of PH significantly worsens morbidity and mortality. In addition, a small subset of patients with hypoxic PH develop "out-of-proportion" severe pulmonary hypertension characterized by pulmonary vascular remodeling that is irreversible and similar to that in WHO group I disease. In all cases of hypoxia-related vascular remodeling and PH, inflammation, particularly persistent inflammation, is thought to play a role. This review focuses on the effects of hypoxia on pulmonary vascular cells and the signaling pathways involved in the initiation and perpetuation of vascular inflammation, especially as they relate to vascular remodeling and transition to chronic irreversible PH. We hypothesize that the combination of hypoxia and local tissue factors/cytokines ("second hit") antagonizes tissue homeostatic cellular interactions between mesenchymal cells (fibroblasts and/or smooth muscle cells) and macrophages and arrests these cells in an epigenetically locked and permanently activated proremodeling and proinflammatory phenotype. This aberrant cellular cross-talk between mesenchymal cells and macrophages promotes transition to chronic nonresolving inflammation and vascular remodeling, perpetuating PH. A better understanding of these signaling pathways may lead to the development of specific therapeutic targets, as none are currently available for WHO group III disease.
Collapse
Affiliation(s)
- Steven C Pugliese
- Developmental Lung Biology, Cardiovascular Pulmonary Research Laboratories, Division of Pulmonary Sciences and Critical Care Medicine, Division of Pediatrics-Critical Care, Departments of Medicine and Pediatrics, University of Colorado, Anschutz Medical Campus, Aurora, Colorado;
| | - Jens M Poth
- Developmental Lung Biology, Cardiovascular Pulmonary Research Laboratories, Division of Pulmonary Sciences and Critical Care Medicine, Division of Pediatrics-Critical Care, Departments of Medicine and Pediatrics, University of Colorado, Anschutz Medical Campus, Aurora, Colorado
| | - Mehdi A Fini
- Developmental Lung Biology, Cardiovascular Pulmonary Research Laboratories, Division of Pulmonary Sciences and Critical Care Medicine, Division of Pediatrics-Critical Care, Departments of Medicine and Pediatrics, University of Colorado, Anschutz Medical Campus, Aurora, Colorado
| | - Andrea Olschewski
- Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria; and
| | - Karim C El Kasmi
- Department of Pediatrics, Division of Gastroenterology, Hepatology, and Nutrition, University of Colorado Denver, School of Medicine, Anschutz Medical Campus, Aurora, Colorado
| | - Kurt R Stenmark
- Developmental Lung Biology, Cardiovascular Pulmonary Research Laboratories, Division of Pulmonary Sciences and Critical Care Medicine, Division of Pediatrics-Critical Care, Departments of Medicine and Pediatrics, University of Colorado, Anschutz Medical Campus, Aurora, Colorado
| |
Collapse
|
24
|
Abstract
AIMS Endothelium-dependent vasorelaxation is mediated by endothelium-derived relaxing factor and endothelium-derived hyperpolarizing factor (EDHF). However, the molecular entity of EDHF remains unclear. The present study examined whether hydrogen sulfide (H₂S) acts as EDHF and how H₂S mediates EDHF pathways from endothelial origination to downstream target of smooth muscle cells (SMCs). RESULTS We found that knocking-out the expression of cystathionine γ-lyase (CSE) in mice (CSE-knockout [KO]) elevated resting-membrane-potential of SMCs and eliminated methacholine-induced endothelium-dependent relaxation of mesenteric arteries, but not that of aorta. Methacholine, a cholinergic-muscarinic agonist, hyperpolarized SMC in endothelium-intact mesenteric arteries from wide-type mice. This effect was inhibited by muscarinic antagonist (atropine) or the co-application of charybdotoxin and apamin, which blocked intermediate- and small-conductance KCa (IKCa and SKCa) channels, or abolished in CSE-KO mice. Supplementation of exogenous H₂S hyperpolarized vascular SMCs and endothelial cells from wide-type and CSE-KO mice. Both methacholine and H₂S induced greater SMC hyperpolarization of female wide-type mesenteric arteries than that of male ones. H2S-induced hyperpolarization is blocked by -SH oxidants and -SSH inhibitor. The expression of SK2.3 but not IK3.1 channel in vascular tissues was increased by H₂S and decreased by CSE inhibitor or CSE gene KO. INNOVATION AND CONCLUSIONS Taken together, H₂S is an EDHF. The identification of H2S as an EDHF will not only solve one of the long-lasting perplexing puzzles for the mechanisms underlying endothelium-dependent vasorelaxation, but also shed light on potential therapeutic effects of H₂S on pathological abnormalities in peripheral resistance arteries.
Collapse
Affiliation(s)
- Guanghua Tang
- 1 Department of Biology, Lakehead University , Thunder Bay, Ontario, Canada
| | | | | | | | | | | |
Collapse
|
25
|
Moccia F, Berra-Romani R, Tanzi F. Update on vascular endothelial Ca 2+ signalling: A tale of ion channels, pumps and transporters. World J Biol Chem 2012; 3:127-58. [PMID: 22905291 PMCID: PMC3421132 DOI: 10.4331/wjbc.v3.i7.127] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Revised: 07/04/2012] [Accepted: 07/11/2012] [Indexed: 02/05/2023] Open
Abstract
A monolayer of endothelial cells (ECs) lines the lumen of blood vessels and forms a multifunctional transducing organ that mediates a plethora of cardiovascular processes. The activation of ECs from as state of quiescence is, therefore, regarded among the early events leading to the onset and progression of potentially lethal diseases, such as hypertension, myocardial infarction, brain stroke, and tumor. Intracellular Ca2+ signals have long been know to play a central role in the complex network of signaling pathways regulating the endothelial functions. Notably, recent work has outlined how any change in the pattern of expression of endothelial channels, transporters and pumps involved in the modulation of intracellular Ca2+ levels may dramatically affect whole body homeostasis. Vascular ECs may react to both mechanical and chemical stimuli by generating a variety of intracellular Ca2+ signals, ranging from brief, localized Ca2+ pulses to prolonged Ca2+ oscillations engulfing the whole cytoplasm. The well-defined spatiotemporal profile of the subcellular Ca2+ signals elicited in ECs by specific extracellular inputs depends on the interaction between Ca2+ releasing channels, which are located both on the plasma membrane and in a number of intracellular organelles, and Ca2+ removing systems. The present article aims to summarize both the past and recent literature in the field to provide a clear-cut picture of our current knowledge on the molecular nature and the role played by the components of the Ca2+ machinery in vascular ECs under both physiological and pathological conditions.
Collapse
Affiliation(s)
- Francesco Moccia
- Francesco Moccia, Franco Tanzi, Department of Biology and Biotechnologies "Lazzaro Spallanzani", Laboratory of Physiology, University of Pavia, Via Forlanini 6, 27100 Pavia, Italy
| | | | | |
Collapse
|
26
|
Kapela A, Nagaraja S, Parikh J, Tsoukias NM. Modeling Ca2+ signaling in the microcirculation: intercellular communication and vasoreactivity. Crit Rev Biomed Eng 2012; 39:435-60. [PMID: 22196162 DOI: 10.1615/critrevbiomedeng.v39.i5.50] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
A network of intracellular signaling pathways and complex intercellular interactions regulate calcium mobilization in vascular cells, arteriolar tone, and blood flow. Different endothelium-derived vasoreactive factors have been identified and the importance of myoendothelial communication in vasoreactivity is now well appreciated. The ability of many vascular networks to conduct signals upstream also is established. This phenomenon is critical for both short-term changes in blood perfusion as well as long-term adaptations of a vascular network. In addition, in a phenomenon termed vasomotion, arterioles often exhibit spontaneous oscillations in diameter. This is thought to improve tissue oxygenation and enhance blood flow. Experimentation has begun to reveal important aspects of the regulatory machinery and the significance of these phenomena for the regulation of local perfusion and oxygenation. Mathematical modeling can assist in elucidating the complex signaling mechanisms that participate in these phenomena. This review highlights some of the important experimental studies and relevant mathematical models that provide the current understanding of these mechanisms in vasoreactivity.
Collapse
Affiliation(s)
- Adam Kapela
- Department of Biomedical Engineering, Florida International University, Miami, FL, USA
| | | | | | | |
Collapse
|
27
|
Abstract
It has been known for more than 60 years, and suspected for over 100, that alveolar hypoxia causes pulmonary vasoconstriction by means of mechanisms local to the lung. For the last 20 years, it has been clear that the essential sensor, transduction, and effector mechanisms responsible for hypoxic pulmonary vasoconstriction (HPV) reside in the pulmonary arterial smooth muscle cell. The main focus of this review is the cellular and molecular work performed to clarify these intrinsic mechanisms and to determine how they are facilitated and inhibited by the extrinsic influences of other cells. Because the interaction of intrinsic and extrinsic mechanisms is likely to shape expression of HPV in vivo, we relate results obtained in cells to HPV in more intact preparations, such as intact and isolated lungs and isolated pulmonary vessels. Finally, we evaluate evidence regarding the contribution of HPV to the physiological and pathophysiological processes involved in the transition from fetal to neonatal life, pulmonary gas exchange, high-altitude pulmonary edema, and pulmonary hypertension. Although understanding of HPV has advanced significantly, major areas of ignorance and uncertainty await resolution.
Collapse
Affiliation(s)
- J T Sylvester
- Division of Pulmonary & Critical Care Medicine, Department of Medicine, The Johns Hopkins University School ofMedicine, Baltimore, Maryland, USA.
| | | | | | | |
Collapse
|
28
|
Abstract
The endothelium is a highly dynamic structure lining the inside of blood vessels that exhibits physical and chemical properties that are critical determinants of overall vascular function. Physically, the endothelium constitutes a semipermeable barrier. Chemically, the endothelium synthesizes numerous factors such as reactive oxygen species (ROS) that can act as autocrine and paracrine signaling molecules. Oxidative stress results when ROS levels increase to levels that cause cellular injury, and, in the endothelium oxidative stress leads to barrier disruption. Endothelial barrier disruption also results from increased cytosolic calcium through store-operated calcium (SOC) entry channels. Although it is known that ROS can interact with and regulate some ion channels, relatively little is known about the interaction of these species with components of endothelial SOC entry channels, the canonical transient receptor potential (TRPC) proteins. Here we review our current understanding of ROS-mediated TRPC channel function and how it affects SOC entry and endothelial barrier disruption.
Collapse
Affiliation(s)
- Donna L Cioffi
- Department of Biochemistry and Molecular Biology, Center for Lung Biology, University of South Alabama College of Medicine, Mobile, AL 36688, USA.
| |
Collapse
|
29
|
Shaikh MA, Wall DJN, David T. Macro-scale phenomena of arterial coupled cells: a massively parallel simulation. J R Soc Interface 2011; 9:972-87. [PMID: 21920960 DOI: 10.1098/rsif.2011.0453] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Impaired mass transfer characteristics of blood-borne vasoactive species such as adenosine triphosphate in regions such as an arterial bifurcation have been hypothesized as a prospective mechanism in the aetiology of atherosclerotic lesions. Arterial endothelial cells (ECs) and smooth muscle cells (SMCs) respond differentially to altered local haemodynamics and produce coordinated macro-scale responses via intercellular communication. Using a computationally designed arterial segment comprising large populations of mathematically modelled coupled ECs and SMCs, we investigate their response to spatial gradients of blood-borne agonist concentrations and the effect of micro-scale-driven perturbation on the macro-scale. Altering homocellular (between same cell type) and heterocellular (between different cell types) intercellular coupling, we simulated four cases of normal and pathological arterial segments experiencing an identical gradient in the concentration of the agonist. Results show that the heterocellular calcium (Ca(2+)) coupling between ECs and SMCs is important in eliciting a rapid response when the vessel segment is stimulated by the agonist gradient. In the absence of heterocellular coupling, homocellular Ca(2+) coupling between SMCs is necessary for propagation of Ca(2+) waves from downstream to upstream cells axially. Desynchronized intracellular Ca(2+) oscillations in coupled SMCs are mandatory for this propagation. Upon decoupling the heterocellular membrane potential, the arterial segment looses the inhibitory effect of ECs on the Ca(2+) dynamics of the underlying SMCs. The full system comprises hundreds of thousands of coupled nonlinear ordinary differential equations simulated on the massively parallel Blue Gene architecture. The use of massively parallel computational architectures shows the capability of this approach to address macro-scale phenomena driven by elementary micro-scale components of the system.
Collapse
Affiliation(s)
- Mohsin Ahmed Shaikh
- Center for Bioengineering, University of Canterbury, Christchurch, New Zealand.
| | | | | |
Collapse
|
30
|
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: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
|
31
|
Kolte D, Osman N, Yang J, Shariat-Madar Z. High molecular weight kininogen activates B2 receptor signaling pathway in human vascular endothelial cells. J Biol Chem 2011; 286:24561-71. [PMID: 21586566 DOI: 10.1074/jbc.m110.211557] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
The nonenzymatic cofactor high molecular weight kininogen (HK) is a precursor of bradykinin (BK). The production of BK from HK by plasma kallikrein has been implicated in the pathogenesis of inflammation and vascular injury. However, the functional role of HK in the absence of prekallikrein (PK), the proenzyme of plasma kallikrein, on vascular endothelial cells is not fully defined. In addition, no clinical abnormality is seen in PK-deficient patients. Therefore, an investigation into the effect of HK, in the absence of PK, on human pulmonary artery endothelial cell (HPAEC) function was performed. HK caused a marked and dose-dependent increase in the intracellular calcium [Ca(2+)](i) level in HPAEC. Gd(3+) and verapamil potentiated the HK-induced increase in [Ca(2+)](i). HK-induced Ca(2+) increase stimulated endothelial nitric oxide (NO) and prostacyclin (PGI(2)) production. The inhibitors of B(2) receptor-dependent signaling pathway impaired HK-mediated signal transduction in HPAEC. HK had no effect on endothelial permeability at physiological concentration. This study demonstrated that HK regulates endothelial cell function. HK could play an important role in maintaining normal endothelial function and blood flow and serve as a cardioprotective peptide.
Collapse
Affiliation(s)
- Dhaval Kolte
- Departmen of Pharmacology, University of Mississippi, USA
| | | | | | | |
Collapse
|
32
|
Tsoukias NM. Calcium dynamics and signaling in vascular regulation: computational models. WILEY INTERDISCIPLINARY REVIEWS-SYSTEMS BIOLOGY AND MEDICINE 2011; 3:93-106. [PMID: 21061306 DOI: 10.1002/wsbm.97] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Calcium is a universal signaling molecule with a central role in a number of vascular functions including in the regulation of tone and blood flow. Experimentation has provided insights into signaling pathways that lead to or affected by Ca(2+) mobilization in the vasculature. Mathematical modeling offers a systematic approach to the analysis of these mechanisms and can serve as a tool for data interpretation and for guiding new experimental studies. Comprehensive models of calcium dynamics are well advanced for some systems such as the heart. This review summarizes the progress that has been made in modeling Ca(2+) dynamics and signaling in vascular cells. Model simulations show how Ca(2+) signaling emerges as a result of complex, nonlinear interactions that cannot be properly analyzed using only a reductionist's approach. A strategy of integrative modeling in the vasculature is outlined that will allow linking macroscale pathophysiological responses to the underlying cellular mechanisms.
Collapse
|
33
|
Nediani C, Raimondi L, Borchi E, Cerbai E. Nitric oxide/reactive oxygen species generation and nitroso/redox imbalance in heart failure: from molecular mechanisms to therapeutic implications. Antioxid Redox Signal 2011; 14:289-331. [PMID: 20624031 DOI: 10.1089/ars.2010.3198] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Adaptation of the heart to intrinsic and external stress involves complex modifications at the molecular and cellular levels that lead to tissue remodeling, functional and metabolic alterations, and finally to failure depending upon the nature, intensity, and chronicity of the stress. Reactive oxygen species (ROS) have long been considered as merely harmful entities, but their role as second messengers has gradually emerged. At the same time, our comprehension of the multifaceted role of nitric oxide (NO) and the related reactive nitrogen species (RNS) has been upgraded. The tight interlay between ROS and RNS suggests that their imbalance may implicate the impairment in physiological NO/redox-based signaling that contributes to the failing of the cardiovascular system. This review initially provides basic concepts on the role of nitroso/oxidative stress in the pathophysiology of heart failure with a particular focus on sources of ROS/RNS, their downstream targets, and endogenous modulators. Then, the role of NO/redox regulation of cardiomyocyte function, including calcium homeostasis, electrogenesis, and insulin signaling pathways, is described. Finally, an overview of old and emerging therapeutic opportunities in heart failure is presented, focusing on modulation of NO/redox mechanisms and discussing benefits and limitations.
Collapse
Affiliation(s)
- Chiara Nediani
- Department of Biochemical Sciences, University of Florence, Florence, Italy.
| | | | | | | |
Collapse
|
34
|
Contributory role of endothelium and voltage-gated potassium channels in apocynin-induced vasorelaxations. J Hypertens 2010; 28:2102-10. [DOI: 10.1097/hjh.0b013e32833d0197] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
35
|
Zhang H, Zhang J, Zha R, Hu M, Wang Y. Magnesium lithospermate B decreases [Ca(2+)]i in endothelial cells by inhibiting K(+) currents. Eur J Pharmacol 2010; 650:285-9. [PMID: 20868678 DOI: 10.1016/j.ejphar.2010.09.028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2009] [Revised: 08/27/2010] [Accepted: 09/15/2010] [Indexed: 01/09/2023]
Abstract
Magnesium lithospermate B (MLB) is a hydrophilic active component of Salviae miltiorrhizae Radix. Studies have shown that MLB affected intracellular calcium ([Ca(2+)]i), but the underlying mechanism was unclear yet. The present work was aimed to investigate the underlying mechanism of MLB affecting [Ca(2+)]i in endothelial cells (ECs). Isolated mesentery arteries were employed to test the involvement of L-Ca(2+) channel. [Ca(2+)]i was measured in ECs loaded with Fluo-3. Membrane potential and membrane currents were recorded in ECs using patch-clamp techniques. Results showed that MLB did not inhibit Ca(2+) influx via L-Ca(2+) channel in isolated mesenteric arteries. However, MLB decreased [Ca(2+)]i in a concentration-dependent manner in ECs. MLB depolarized the membrane potential of ECs and inhibited K(+) currents. These results demonstrated that MLB decreased [Ca(2+)]i by inhibiting K(+) currents and depolarizing membrane potential in ECs.
Collapse
Affiliation(s)
- Haifei Zhang
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | | | | | | | | |
Collapse
|
36
|
Celotto AC, Capellini VK, Restini CBA, Baldo CF, Bendhack LM, Evora PRB. Extracellular alkalinization induces endothelium-derived nitric oxide dependent relaxation in rat thoracic aorta. Nitric Oxide 2010; 23:269-74. [PMID: 20682356 DOI: 10.1016/j.niox.2010.07.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2010] [Revised: 07/10/2010] [Accepted: 07/29/2010] [Indexed: 10/19/2022]
Abstract
AIM To investigate the mechanism through which the extracellular alkalinization promotes relaxation in rat thoracic aorta. METHODS The relaxation response to NaOH-induced extracellular alkalinization (7.4-8.5) was measured in aortic rings pre-contracted with phenylephrine (Phe, 10(-6) M). The vascular reactivity experiments were performed in endothelium-intact and -denuded rings, in the presence or and absence of indomethacin (10(-5) M), NG-nitro-l-arginine methyl ester (L-NAME, 10(-4) M), N-(6-Aminohexyl)-5-chloro-1-naphthalenesulfonamide/HCl (W-7, 10(-7) M), 2,5-dimethylbenzimidazole (DMB, 2×10(-5) M) and methyl-β-cyclodextrin (10(-2) M). In addition, the effects of NaOH-induced extracellular alkalinization (pH 8.0 and 8.5) on the intracellular nitric oxide (NO) concentration was evaluated in isolated endothelial cells loaded with diaminofluorescein-FM diacetate (DAF-FM DA, 5 μM), in the presence and absence of DMB (2×10(-5) M). RESULTS The extracellular alkalinization failed to induce any change in vascular tone in aortic rings pre-contracted with KCl. In rings pre-contracted with Phe, the extracellular alkalinization caused relaxation in the endothelium-intact rings only, and this relaxation was maintained after cyclooxygenase inhibition; completely abolished by the inhibition of nitric oxide synthase (NOS), Ca(2+)/calmodulin and Na(+)/Ca(2+) exchanger (NCX), and partially blunted by the caveolae disassembly. CONCLUSIONS These results suggest that, in rat thoracic aorta, that extracellular alkalinization with NaOH activates the NCX reverse mode of endothelial cells in rat thoracic aorta, thereby the intracellular Ca(2+) concentration and activating the Ca(2+)/calmodulin-dependent NOS. In turn, NO is released promoting relaxation.
Collapse
Affiliation(s)
- A C Celotto
- Laboratory of Endothelial Function, Department of Surgery and Anatomy, School of Medicine, University of São Paulo, Ribeirão Preto, SP, Brazil
| | | | | | | | | | | |
Collapse
|
37
|
Triggle CR, Ding H. A review of endothelial dysfunction in diabetes: a focus on the contribution of a dysfunctional eNOS. ACTA ACUST UNITED AC 2010; 4:102-15. [PMID: 20470995 DOI: 10.1016/j.jash.2010.02.004] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2009] [Revised: 01/25/2010] [Accepted: 02/04/2010] [Indexed: 12/31/2022]
Abstract
Although the etiology of vascular dysfunction in diabetes has been extensively investigated in both humans as well as animal models of human diabetes, the relative importance of the cellular pathways involved is still not fully understood. In this review, we focus on reviewing the literature that provides insights into how an acute exposure to hyperglycemia results in a dysregulation of endothelial nitric oxide synthase function, the subsequent downstream effects of endothelial nitric oxide synthase dysregulation, and the development of endothelial dysfunction.
Collapse
Affiliation(s)
- Chris R Triggle
- Department of Medical Education, Weill Cornell Medical College in Qatar, Education City, Doha, Qatar.
| | | |
Collapse
|
38
|
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: 2.5] [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.
Collapse
Affiliation(s)
- Alexander Vang
- Vascular Research Laboratory, Providence VA Medical Center, Providence, RI 02908, USA
| | | | | | | |
Collapse
|
39
|
Ding H, Triggle CR. Endothelial dysfunction in diabetes: multiple targets for treatment. Pflugers Arch 2010; 459:977-94. [PMID: 20238124 DOI: 10.1007/s00424-010-0807-3] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2010] [Revised: 02/13/2010] [Accepted: 02/16/2010] [Indexed: 12/20/2022]
Abstract
Robert Furchgott's discovery of the obligatory role that the endothelium plays in the regulation of vascular tone has proved to be a major advance in terms of our understanding of the cellular basis of diabetic vascular disease. Endothelial dysfunction, as defined by a reduction in the vasodilatation response to an endothelium-dependent vasodilator (such as acetylcholine) or to flow-mediated vasodilatation, is an early indicator for the development of the micro- and macroangipathy that is associated with diabetes. In diabetes, hyperglycaemia plays a key role in the initiation and development of endothelial dysfunction; however, the cellular mechanisms involved as well as the importance of dyslipidaemia and co-morbidities such as hypertension and obesity remain incompletely understood. In this review, we discuss the mechanisms whereby hyperglycaemia, oxidative stress and dyslipidaemia can alter endothelial function and highlight their effects on endothelial nitric oxide synthase (eNOS), the endothelium-dependent hyperpolarising factor (EDHF) pathway(s), as well as on the role of endothelium-derived contracting factors (EDCFs) and adipocyte-derived vasoactive factors such as adipose-derived relaxing factor (ADRF).
Collapse
Affiliation(s)
- Hong Ding
- Department of Pharmacology & Medical Education, Weill Cornell Medical College in Qatar, P.O. Box 24144, Education City, Doha, Qatar
| | | |
Collapse
|
40
|
Halichlorine is a novel L-type Ca2+ channel inhibitor isolated from the marine sponge Halichondria okadai Kadota. Eur J Pharmacol 2010; 628:128-31. [DOI: 10.1016/j.ejphar.2009.11.026] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2009] [Accepted: 11/10/2009] [Indexed: 11/20/2022]
|
41
|
Simon A, Liu GX, Koren G, Choudhary G. cANF causes endothelial cell hyperpolarization by activation of chloride channels. Peptides 2009; 30:2337-42. [PMID: 19682521 DOI: 10.1016/j.peptides.2009.08.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2009] [Revised: 07/06/2009] [Accepted: 08/05/2009] [Indexed: 01/12/2023]
Abstract
OBJECTIVES Natriuretic peptides bind with natriuretic peptide receptor (NPR)-C, which can alter cellular function through its interaction with the G(i) protein complex. NPR-C has been found to mediate the activation of K(+) channels and non-selective cation channels in vascular smooth muscle and cardiac fibroblast cells, respectively. However, the electrophysiological effect of NPR-C activation on endothelial cells (EC) has not been previously examined. In this study we sought to elucidate the effect of cANF(4-23), a selective NPR-C ligand, on EC membrane potential (E(m)). METHODS/RESULTS Changes in EC E(m) was measured through non-invasive fluorescence imaging. EC were preincubated in the potentiometric dye, DiBAC(4)(3) and subsequently exposed to cANF(4-23), in the presence of selective inhibitors of ion-channels or second messengers. NPR-C expression in rat lung microvascular endothelial cells was assessed by RT-PCR. cANF(4-23) induced a sustained decrease in EC cellular fluorescence, indicating endothelial cell hyperpolarization. The cANF-induced hyperpolarization could not be attenuated by TEA, barium, ouabain or by the reduction of extracellular Ca(2+). Further, the cANF-induced hyperpolarization was insensitive to inhibition of G(i) and protein kinase G (PKG), downstream messengers of NPRs. However, the Cl(-) channel inhibitors, 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid, niflumic acid, and hypertonic saline attenuated the cANF-induced hyperpolarization. Perforated patch clamp recordings confirmed the cANF-induced current was carried by Cl(-) and could be inhibited by niflumic acid. RT-PCR confirmed expression of NPR-C in vascular smooth muscle cells but not in EC. CONCLUSIONS cANF causes hyperpolarization that is most likely mediated via activation of Cl(-) channels by a PKG and G(i) independent mechanism.
Collapse
Affiliation(s)
- Aaron Simon
- Vascular Research Laboratory, Providence VA Medical Center, Providence, RI 02908, USA
| | | | | | | |
Collapse
|
42
|
Kapela A, Nagaraja S, Tsoukias NM. A mathematical model of vasoreactivity in rat mesenteric arterioles. II. Conducted vasoreactivity. Am J Physiol Heart Circ Physiol 2009; 298:H52-65. [PMID: 19855062 DOI: 10.1152/ajpheart.00546.2009] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
This study presents a multicellular computational model of a rat mesenteric arteriole to investigate the signal transduction mechanisms involved in the generation of conducted vasoreactivity. The model comprises detailed descriptions of endothelial (ECs) and smooth muscle (SM) cells (SMCs), coupled by nonselective gap junctions. With strong myoendothelial coupling, local agonist stimulation of the EC or SM layer causes local changes in membrane potential (V(m)) that are conducted electrotonically, primarily through the endothelium. When myoendothelial coupling is weak, signals initiated in the SM conduct poorly, but the sensitivity of the SMCs to current injection and agonist stimulation increases. Thus physiological transmembrane currents can induce different levels of local V(m) change, depending on cell's gap junction connectivity. The physiological relevance of current and voltage clamp stimulations in intact vessels is discussed. Focal agonist stimulation of the endothelium reduces cytosolic calcium (intracellular Ca(2+) concentration) in the prestimulated SM layer. This SMC Ca(2+) reduction is attributed to a spread of EC hyperpolarization via gap junctions. Inositol (1,4,5)-trisphosphate, but not Ca(2+), diffusion through homocellular gap junctions can increase intracellular Ca(2+) concentration in neighboring ECs. The small endothelial Ca(2+) spread can amplify the total current generated at the local site by the ECs and through the nitric oxide pathway, by the SMCs, and thus reduces the number of stimulated cells required to induce distant responses. The distance of the electrotonic and Ca(2+) spread depends on the magnitude of SM prestimulation and the number of SM layers. Model results are consistent with experimental data for vasoreactivity in rat mesenteric resistance arteries.
Collapse
Affiliation(s)
- Adam Kapela
- Department of Biomedical Engineering, Florida International University, Miami, FL 33174, USA
| | | | | |
Collapse
|
43
|
Bishara NB, Ding H. Glucose enhances expression of TRPC1 and calcium entry in endothelial cells. Am J Physiol Heart Circ Physiol 2009; 298:H171-8. [PMID: 19855058 DOI: 10.1152/ajpheart.00699.2009] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Hyperglycemia is a major risk factor for endothelial dysfunction and vascular disease, and in the current study, the link to glucose-induced abnormal intracellular Ca(2+) (Ca(i)(2+)) homeostasis was explored in bovine aortic endothelial cells in high glucose (HG; 25 mmol/l) versus low glucose (LG; 5.5 mmol/l; control). Transient receptor potential 1 (TRPC1) ion channel protein, but not TRPC3, TRPC4, or TRPC6 expression, was significantly increased in HG versus LG at 72 h. HG for 4, 24, and 72 h did not change basal Ca(i)(2+) or ATP-induced Ca(i)(2+) release; however, the amplitude of sustained Ca(i)(2+) was significantly increased at 24 and 72 h and reduced by low concentration of the putative, but nonspecific, TRPC blockers, gadolinium, SKF-96365, and 2-aminoethoxydiphenyl borate. Treatment with TRPC1 antisense significantly reduced TRPC1 protein expression and ATP-induced Ca(2+) entry in bovine aortic endothelial cells. Although the link between HG-induced changes in TRPC1 expression, enhanced Ca(2+) entry, and endothelial dysfunction require further study, the current data are suggestive that targeting these pathways may reduce the impact of HG on endothelial function.
Collapse
Affiliation(s)
- N B Bishara
- School of Medical Sciences, Royal Melbourne Institute of Technology University, Bundoora, Victoria, Australia
| | | |
Collapse
|
44
|
Sandow SL, Grayson TH. Limits of isolation and culture: intact vascular endothelium and BKCa. Am J Physiol Heart Circ Physiol 2009; 297:H1-7. [DOI: 10.1152/ajpheart.00042.2009] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The potential physiological role of plasmalemmal large-conductance calcium-activated potassium channels (BKCa) in vascular endothelial cells is controversial. Studies of freshly isolated and cultured vascular endothelial cells provide disparate results, both supporting and refuting a role for BKCa in endothelial function. Most studies using freshly isolated, intact, healthy arteries provide little support for a physiological role for BKCa in the endothelium, although recent work suggests that this may not be the case in diseased vessels. In isolated and cultured vascular endothelial cells, the autocrine action of growth factors, hormones, and vasoactive substances results in phenotypic drift. Such an induced heterogeneity is likely a primary factor accounting for the apparent differences, and often enhanced BKCa expression and function, in isolated and cultured vascular endothelial cells. In a similar manner, heterogeneity in endothelial BKCa expression and function in intact arteries may be representative of normal and disease states, BKCa being absent in normal intact artery endothelium and upregulated in disease where dysfunction induces signals that alter channel expression and function. Indeed, in some intact vessels, there is evidence for the presence of BKCa, such as mRNA and/or specific BK subunits, an observation that is consistent with the potential for rapid upregulation, as may occur in disease. This perspective proposes that the disparity in the results obtained for BKCa expression and function from freshly isolated and cultured vascular endothelial cells is largely due to variability in experimental conditions and, furthermore, that the expression of BKCa in intact artery endothelium is primarily associated with disease. Although answers to physiologically relevant questions may only be available in atypical physiological conditions, such as those of isolation and culture, the limitations of these methods require open and objective recognition.
Collapse
|
45
|
Cell swelling, impulse conduction, and cardiac arrhythmias in the failing heart. Opposite effects of angiotensin II and angiotensin (1–7) on cell volume regulation. Mol Cell Biochem 2009; 330:211-7. [DOI: 10.1007/s11010-009-0135-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2009] [Accepted: 04/16/2009] [Indexed: 01/20/2023]
|
46
|
De Mello WC. Renin Angiotensin system as a regulator of cell volume. Implications to myocardial ischemia. Curr Cardiol Rev 2009; 5:65-8. [PMID: 20066151 PMCID: PMC2803291 DOI: 10.2174/157340309787048149] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2008] [Revised: 09/05/2008] [Accepted: 09/05/2008] [Indexed: 01/08/2023] Open
Abstract
It is known that long lasting changes in cell volume are incompatible with cellular functions. In the present review, I discussed the role of cell volume on gene expression and protein synthesis as well as the importance of the renin angiotensin system on the regulation of cell volume in the failing heart. Moreover, the relationship between mechanical stretch, cell volume and the renin angiotensin system as well some translational studies are also described and their relevance to the prevention or reduction of cardiac damage during myocardial ischemia is emphasized.
Collapse
Affiliation(s)
- Walmor C De Mello
- Medical Sciences Campus, School of Medicine, UPR, San Juan, PR 00936-5067, USA
| |
Collapse
|
47
|
Park WS, Ko EA, Jung ID, Son YK, Kim HK, Kim N, Park SY, Hong KW, Park YM, Choi TH, Han J. APE1/Ref-1 promotes the effect of angiotensin II on Ca2+ -activated K+ channel in human endothelial cells via suppression of NADPH oxidase. Arch Pharm Res 2008; 31:1291-301. [PMID: 18958420 DOI: 10.1007/s12272-001-2109-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2008] [Revised: 08/07/2008] [Accepted: 08/08/2008] [Indexed: 11/24/2022]
Abstract
The effects of angiotensin II (Ang II) on whole-cell large conductance Ca(2+)-activated K(+) (BK(Ca)) currents was investigated in control and Apurinic/apyrimidinic endonuclease1/redox factor 1 (APE1/Ref-1)-overexpressing human umbilical vein endothelial cells (HUVECs). Ang II blocked the BK(Ca) current in a dose-dependent fashion, and this inhibition was greater in APE1/Ref-1-overexpressing HUVECs than in control HUVECs (half-inhibition values of 102.81+/-9.54 nM and 11.34+/-0.39 nM in control and APE1/Ref-1-overexpressing HUVECs, respectively). Pretreatment with the NADPH oxidase inhibitor diphenyleneiodonium (DPI) or knock down of NADPH oxidase (p22 phox) using siRNA increased the inhibitory effect of Ang II on the BK(Ca) currents, similar to the effect of APE1/Ref-1 overexpression. In addition, application of Ang II increased the superoxide and hydrogen peroxide levels in the control HUVECs but not in APE1/Ref-1-overexpressing HUVECs. Furthermore, direct application of hydrogen peroxide increased BK(Ca) channel activity. Finally, the inhibitory effect of Ang II on the BK(Ca) current was blocked by an antagonist of the Ang II type 1 (AT(1)) receptor in both control and APE1/Ref-1-overexpressing HUVECs. From these results, we conclude that the inhibitory effect of Ang II on BK(Ca) channel function is NADPH oxidase-dependent and may be promoted by APE1/Ref-1.
Collapse
Affiliation(s)
- Won Sun Park
- National Research Laboratory for Mitochondrial Signaling Laboratory, FIRST Mitochondria Research Group, Department of Physiology and Biophysics, College of Medicine, Medical Research Center, Inje University, Busan, Korea
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
48
|
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: 0.6] [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.
Collapse
|
49
|
Xu YC, Leung GPH, Wong PYD, Vanhoutte PM, Man RYK. Kaempferol stimulates large conductance Ca2+ -activated K+ (BKCa) channels in human umbilical vein endothelial cells via a cAMP/PKA-dependent pathway. Br J Pharmacol 2008; 154:1247-53. [PMID: 18493242 DOI: 10.1038/bjp.2008.194] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND AND PURPOSE Kaempferol has been shown to possess a vasodilator effect but its mechanism of action remains unclear. In this study, experiments were carried out to study the effect of kaempferol on K+ channels in endothelial cells. EXPERIMENTAL APPROACH K+ channel activities in human umbilical vein endothelial cells (HUVECs) were studied by conventional whole cell and cell-attached patch-clamp electrophysiology. KEY RESULTS Kaempferol stimulated an outward-rectifying current in HUVECs in a dose-dependent manner with an EC50 value of 2.5+/-0.02 microM. This kaempferol-induced current was abolished by large conductance Ca2+ -activated K+ (BKCa) channel blockers, such as iberiotoxin (IbTX) and charybdotoxin (ChTX), whereas the small conductance Ca2+ -activated K+ (SKCa) channel blocker, apamin, and the voltage-dependent K+ (KV) channel blocker, 4-aminopyridine, had no effect. Cell-attached patches demonstrated that kaempferol increased the open probability of BkCa channels in HUVECs. Clamping intracellular Ca2+ did not prevent kaempferol-induced increases in outward current. In addition, the kaempferol-induced current was diminished by the adenylyl cyclase inhibitor SQ22536, the cAMP antagonist Rp-8-Br-cAMP and the PKA inhibitor KT5720, but was not affected by the guanylyl cyclase inhibitor ODQ, the cGMP antagonist Rp-8-Br-cGMP and the PKG inhibitor KT5823. The activation of BKCa channels by kaempferol caused membrane hyperpolarization of HUVECs. CONCLUSION AND IMPLICATIONS These results demonstrate that kaempferol activates the opening of BKCa channels in HUVECs via a cAMP/PKA-dependent pathway, resulting in membrane hyperpolarization. This mechanism may partly account for the vasodilator effects of kaempferol.
Collapse
Affiliation(s)
- Y C Xu
- Department of Pharmacology, Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | | | | | | | | |
Collapse
|
50
|
Affiliation(s)
- Caryl E Hill
- Division of Neuroscience, John Curtin School of Medical Research, Australian National University, Canberra, ACT, 2601, Australia.
| |
Collapse
|