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de Vries T, Labruijere S, Rivera-Mancilla E, Garrelds IM, de Vries R, Schutter D, van den Bogaerdt A, Poyner DR, Ladds G, Danser AHJ, MaassenVanDenBrink A. Intracellular pathways of calcitonin gene-related peptide-induced relaxation of human coronary arteries: A key role for Gβγ subunit instead of cAMP. Br J Pharmacol 2024; 181:2478-2491. [PMID: 38583945 DOI: 10.1111/bph.16372] [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: 11/15/2023] [Revised: 03/01/2024] [Accepted: 03/07/2024] [Indexed: 04/09/2024] Open
Abstract
BACKGROUND AND PURPOSE Calcitonin gene-related peptide (CGRP) is a potent vasodilator. While its signalling is assumed to be mediated via increases in cAMP, this study focused on elucidating the actual intracellular signalling pathways involved in CGRP-induced relaxation of human isolated coronary arteries (HCA). EXPERIMENTAL APPROACH HCA were obtained from heart valve donors (27 M, 25 F, age 54 ± 2 years). Concentration-response curves to human α-CGRP or forskolin were constructed in HCA segments, incubated with different inhibitors of intracellular signalling pathways, and intracellular cAMP levels were measured with and without stimulation. RESULTS Adenylyl cyclase (AC) inhibitors SQ22536 + DDA and MDL-12330A, and PKA inhibitors Rp-8-Br-cAMPs and H89, did not inhibit CGRP-induced relaxation of HCA, nor did the guanylyl cyclase inhibitor ODQ, PKG inhibitor KT5823, EPAC1/2 inhibitor ESI09, potassium channel blockers TRAM-34 + apamin, iberiotoxin or glibenclamide, or the Gαq inhibitor YM-254890. Phosphodiesterase inhibitors induced a concentration-dependent decrease in the response to KCl but did not potentiate relaxation to CGRP. Relaxation to forskolin was not blocked by PKA or AC inhibitors, although AC inhibitors significantly inhibited the increase in cAMP. Inhibition of Gβγ subunits using gallein significantly inhibited the relaxation to CGRP in human coronary arteries. CONCLUSION While CGRP signalling is generally assumed to act via cAMP, the CGRP-induced vasodilation in HCA was not inhibited by targeting this intracellular signalling pathway at different levels. Instead, inhibition of Gβγ subunits did inhibit the relaxation to CGRP, suggesting a different mechanism of CGRP-induced relaxation than generally believed.
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Affiliation(s)
- Tessa de Vries
- Division of Vascular Medicine and Pharmacology, Department of Internal Medicine, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - Sieneke Labruijere
- Division of Vascular Medicine and Pharmacology, Department of Internal Medicine, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - Eduardo Rivera-Mancilla
- Division of Vascular Medicine and Pharmacology, Department of Internal Medicine, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - Ingrid M Garrelds
- Division of Vascular Medicine and Pharmacology, Department of Internal Medicine, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - René de Vries
- Division of Vascular Medicine and Pharmacology, Department of Internal Medicine, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - Dennis Schutter
- Division of Vascular Medicine and Pharmacology, Department of Internal Medicine, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | | | - David R Poyner
- School of Life and Health Sciences, Aston University, Aston Triangle, Birmingham, UK
| | - Graham Ladds
- Department of Pharmacology, University of Cambridge, Cambridge, UK
| | - A H Jan Danser
- Division of Vascular Medicine and Pharmacology, Department of Internal Medicine, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - Antoinette MaassenVanDenBrink
- Division of Vascular Medicine and Pharmacology, Department of Internal Medicine, Erasmus MC University Medical Center, Rotterdam, The Netherlands
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The Role of Bone Morphogenetic Protein Receptor Type 2 ( BMPR2) and the Prospects of Utilizing Induced Pluripotent Stem Cells (iPSCs) in Pulmonary Arterial Hypertension Disease Modeling. Cells 2022; 11:cells11233823. [PMID: 36497082 PMCID: PMC9741276 DOI: 10.3390/cells11233823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 11/25/2022] [Accepted: 11/25/2022] [Indexed: 12/03/2022] Open
Abstract
Pulmonary arterial hypertension (PAH) is a progressive disease characterized by increased pulmonary vascular resistance (PVR), causing right ventricular hypertrophy and ultimately death from right heart failure. Heterozygous mutations in the bone morphogenetic protein receptor type 2 (BMPR2) are linked to approximately 80% of hereditary, and 20% of idiopathic PAH cases, respectively. While patients carrying a BMPR2 gene mutation are more prone to develop PAH than non-carriers, only 20% will develop the disease, whereas the majority will remain asymptomatic. PAH is characterized by extreme vascular remodeling that causes pulmonary arterial endothelial cell (PAEC) dysfunction, impaired apoptosis, and uncontrolled proliferation of the pulmonary arterial smooth muscle cells (PASMCs). To date, progress in understanding the pathophysiology of PAH has been hampered by limited access to human tissue samples and inadequacy of animal models to accurately mimic the pathogenesis of human disease. Along with the advent of induced pluripotent stem cell (iPSC) technology, there has been an increasing interest in using this tool to develop patient-specific cellular models that precisely replicate the pathogenesis of PAH. In this review, we summarize the currently available approaches in iPSC-based PAH disease modeling and explore how this technology could be harnessed for drug discovery and to widen our understanding of the pathophysiology of PAH.
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Intravenous milrinone for treatment of delayed cerebral ischaemia following subarachnoid haemorrhage: a pooled systematic review. Neurosurg Rev 2021; 44:3107-3124. [PMID: 33682040 DOI: 10.1007/s10143-021-01509-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2020] [Revised: 01/26/2021] [Accepted: 02/22/2021] [Indexed: 10/22/2022]
Abstract
Small trials have demonstrated promising results utilising intravenous milrinone for the treatment of delayed cerebral ischaemia (DCI) after subarachnoid haemorrhage (SAH). Here we summarise and contextualise the literature and discuss the future directions of intravenous milrinone for DCI. A systematic, pooled analysis of literature was performed in accordance with the PRISMA statement. Methodological rigour was analysed using the MINORS criteria. Extracted data included patient population; treatment protocol; and clinical, radiological, and functional outcome. The primary outcome was clinical resolution of DCI. Eight hundred eighteen patients from 10 single-centre, observational studies were identified. Half (n = 5) of the studies were prospective and all were at high risk of bias. Mean age was 52 years, and females (69%) outnumbered males. There was a similar proportion of low-grade (WFNS 1-2) (49.7%) and high-grade (WFNS 3-5) (50.3%) SAH. Intravenous milrinone was administered to 523/818 (63.9%) participants. Clinical resolution of DCI was achieved in 375/424 (88%), with similar rates demonstrated with intravenous (291/330, 88%) and combined intra-arterial-intravenous (84/94, 89%) therapy. Angiographic response was seen in 165/234 (71%) receiving intravenous milrinone. Hypotension (70/303, 23%) and hypokalaemia (31/287, 11%) were common drug effects. Four cases (0.5%) of drug intolerance occurred. Good functional outcome was achieved in 271/364 (74%) patients. Cerebral infarction attributable to DCI occurred in 47/250 (19%), with lower rates in asymptomatic spasm. Intravenous milrinone is a safe and feasible therapy for DCI. A signal for efficacy is demonstrated in small, low-quality trials. Future research should endeavour to establish the optimal protocol and dose, prior to a phase-3 study.
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Cui X, Wang J, Li Y, Couse ZG, Risoleo TF, Moayeri M, Leppla SH, Malide D, Yu ZX, Eichacker PQ. Bacillus anthracis edema toxin inhibits hypoxic pulmonary vasoconstriction via edema factor and cAMP-mediated mechanisms in isolated perfused rat lungs. Am J Physiol Heart Circ Physiol 2021; 320:H36-H51. [PMID: 33064559 PMCID: PMC7847081 DOI: 10.1152/ajpheart.00362.2020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 10/15/2020] [Accepted: 10/15/2020] [Indexed: 12/31/2022]
Abstract
Bacillus anthracis edema toxin (ET) inhibited lethal toxin-stimulated pulmonary artery pressure (Ppa) and increased lung cAMP levels in our previous study. We therefore examined whether ET inhibits hypoxic pulmonary vasoconstriction (HPV). Following baseline hypoxic measures in isolated perfused lungs from healthy rats, compared with diluent, ET perfusion reduced maximal Ppa increases (mean ± SE percentage of maximal Ppa increase with baseline hypoxia) during 6-min hypoxic periods (FIO2 = 0%) at 120 min (16 ± 6% vs. 51 ± 6%, P = 0.004) and 180 min (11.4% vs. 55 ± 6%, P = 0.01). Protective antigen-mAb (PA-mAb) and adefovir inhibit host cell edema factor uptake and cAMP production, respectively. In lungs perfused with ET following baseline measures, compared with placebo, PA-mAb treatment increased Ppa during hypoxia at 120 and 180 min (56 ± 6% vs. 10 ± 4% and 72 ± 12% vs. 12 ± 3%, respectively, P ≤ 0.01) as did adefovir (84 ± 10% vs. 16.8% and 123 ± 21% vs. 26 ± 11%, respectively, P ≤ 0.01). Compared with diluent, lung perfusion with ET for 180 min reduced the slope of the relationships between Ppa and increasing concentrations of endothelin-1 (ET-1) (21.12 ± 2.96 vs. 3.00 ± 0.76 × 108 cmH2O/M, P < 0.0001) and U46619, a thromboxane A2 analogue (7.15 ± 1.01 vs. 3.74 ± 0.31 × 107 cmH2O/M, P = 0.05) added to perfusate. In lungs isolated from rats after 15 h of in vivo infusions with either diluent, ET alone, or ET with PA-mAb, compared with diluent, the maximal Ppa during hypoxia and the slope of the relationship between change in Ppa and ET-1 concentration added to the perfusate were reduced in lungs from animals challenged with ET alone (P ≤ 0.004) but not with ET and PA-mAb together (P ≥ 0.73). Inhibition of HPV by ET could aggravate hypoxia during anthrax pulmonary infection.NEW & NOTEWORTHY The most important findings here are edema toxin's potent adenyl cyclase activity can interfere with hypoxic pulmonary vasoconstriction, an action that could worsen hypoxemia during invasive anthrax infection with lung involvement. These findings, coupled with other studies showing that lethal toxin can disrupt pulmonary vascular integrity, indicate that both toxins can contribute to pulmonary pathophysiology during infection. In combination, these investigations provide a further basis for the use of antitoxin therapies in patients with worsening invasive anthrax disease.
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Affiliation(s)
- Xizhong Cui
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland
| | - Jeffrey Wang
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland
| | - Yan Li
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland
| | - Zoe G Couse
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland
| | - Thomas F Risoleo
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland
| | - Mahtab Moayeri
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland
| | - Stephen H Leppla
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland
| | - Daniela Malide
- National Heart, Lung, and Blood Institute, Bethesda, Maryland
| | - Zu-Xi Yu
- National Heart, Lung, and Blood Institute, Bethesda, Maryland
| | - Peter Q Eichacker
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland
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Nan Y, Zeng X, Jin Z, Li N, Chen Z, Chen J, Wang D, Wang Y, Lin Z, Ying L. PDE1 or PDE5 inhibition augments NO-dependent hypoxic constriction of porcine coronary artery via elevating inosine 3',5'-cyclic monophosphate level. J Cell Mol Med 2020; 24:14514-14524. [PMID: 33169529 PMCID: PMC7754025 DOI: 10.1111/jcmm.16078] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Revised: 10/17/2020] [Accepted: 10/25/2020] [Indexed: 12/30/2022] Open
Abstract
Hypoxic coronary vasospasm may lead to myocardial ischaemia and cardiac dysfunction. Inosine 3',5'-cyclic monophosphate (cIMP) is a putative second messenger to mediate this pathological process. Nevertheless, it remains unclear as to whether levels of cIMP can be regulated in living tissue such as coronary artery and if so, what is the consequence of this regulation on hypoxia-induced vasoconstriction. In the present study, we found that cIMP was a key determinant of hypoxia-induced constriction but not that of the subsequent relaxation response in porcine coronary arteries. Subsequently, coronary arteries were treated with various phosphodiesterase (PDE) inhibitors to identify PDE types that are capable of regulating cIMP levels. We found that inhibition of PDE1 and PDE5 substantially elevated cIMP content in endothelium-denuded coronary artery supplemented with exogenous purified cIMP. However, cGMP levels were far lower than their levels in intact coronary arteries and lower than cIMP levels measured in endothelium-denuded coronary arteries supplemented with exogenous cIMP. The increased cIMP levels induced by PDE1 or PDE5 inhibition further led to augmented hypoxic constriction without apparently affecting the relaxation response. In intact coronary artery, PDE1 or PDE5 inhibition up-regulated cIMP levels under hypoxic condition. Concomitantly, cGMP level increased to a comparable level. Nevertheless, the hypoxia-mediated constriction was enhanced in this situation that was largely compromised by an even stronger inhibition of PDEs. Taken together, these data suggest that cIMP levels in coronary arteries are regulated by PDE1 and PDE5, whose inhibition at a certain level leads to increased cIMP content and enhanced hypoxic constriction.
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Affiliation(s)
- Yan Nan
- Department of Neonatology, The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, China
| | - Xueqin Zeng
- Department of Pathophysiology, School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, China
| | - Zhiyi Jin
- Department of Pathophysiology, School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, China
| | - Na Li
- Department of Pathophysiology, School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, China.,Department of Pathology, Wenzhou Central Hospital, Wenzhou, China
| | - Zhengju Chen
- Department of Physiology and Pathophysiology, Peking University Health Science Center, Beijing, China
| | - Jiantong Chen
- Department of Pathophysiology, School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, China
| | - Dezhong Wang
- Institute of Life Sciences, Wenzhou University, Wenzhou, China
| | - Yang Wang
- Department of Pathophysiology, School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, China
| | - Zhenlang Lin
- Department of Neonatology, The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, China
| | - Lei Ying
- Department of Pathophysiology, School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, China
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Beta2-adrenergic receptor agonist inhibits keratinocyte proliferation by mechanisms involving nitric oxide. Postepy Dermatol Alergol 2020; 38:396-403. [PMID: 34377119 PMCID: PMC8330852 DOI: 10.5114/ada.2020.92918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 12/19/2019] [Indexed: 11/17/2022] Open
Abstract
Introduction Beta2-adrenoceptors regulate proliferation of keratinocytes. Nitric oxide (NO) produced by keratinocytes through stimulation of nitric oxide synthase (NOS) mediates keratinocyte proliferation. Aim: In this study, the mechanism interaction β-ARs and NO production on keratinocyte will be explored, and the important for proliferation will be studied. Material and methods To understand the relationship among β2-adrenoceptors, NO production and proliferation in keratinocytes, the experiment is divided to two parts. In the first part of the experiment, keratinocytes are divided into five groups which are treated with 0 M, 10-7 M, 10-6 M, 5 × 10-6 M and 10-5 M isoproterenol, respectively. In the second part of the experiment, the keratinocytes are divided into five groups which are treated with 10-5 M isoproterenol and L-NMMA at doses of 0 M, 10-6 M, 5 × 10-6 M, 10-5 M and 5 × 10-5 M, respectively. We examine NOS expression, NO production, c-AMP level and proliferation in human keratinocytes. Results The results show that isoproterenol results in iNOS and ncNOS protein raised and the elevation of nitric oxide. L-NMMA can block the increase of iNOS and ncNOS protein expression and the ability to inhibit proliferation caused by isoproterenol. Conclusions Beta2-adrenergic receptor agonist mediates nitric oxide synthase to affect keratinocyte proliferation in skin. The physiological and pathological relationship of these discoveries remains to be defined. These results can provide new possibilities in the therapy of integumentary disease conditions linked with the dysfunction of β-AR-mediated NO production.
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Hocking KM, Evans BC, Komalavilas P, Cheung-Flynn J, Duvall CL, Brophy CM. Nanotechnology Enabled Modulation of Signaling Pathways Affects Physiologic Responses in Intact Vascular Tissue. Tissue Eng Part A 2018; 25:416-426. [PMID: 30132374 DOI: 10.1089/ten.tea.2018.0169] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
IMPACT STATEMENT Subarachnoid hemorrhage (SAH) is associated with vasospasm that is refractory to traditional vasodilators, and inhibition of vasospasm after SAH remains a large unmet clinical need. SAH causes changes in the phosphorylation state of the small heat shock proteins (HSPs), HSP20 and HSP27, in the vasospastic vessels. In this study, the levels of HSP27 and HSP20 were manipulated using nanotechnology to mimic the intracellular phenotype of SAH-induced vasospasm, and the effect of this manipulation was tested on vasomotor responses in intact tissues. This work provides insight into potential therapeutic targets for the development of more effective treatments for SAH induced vasospasm.
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Affiliation(s)
- Kyle M Hocking
- 1 Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee.,2 Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee
| | - Brian C Evans
- 1 Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee.,2 Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee
| | - Padmini Komalavilas
- 1 Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee.,3 VA Tennessee Valley Healthcare System, Nashville, Tennessee
| | - Joyce Cheung-Flynn
- 1 Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Craig L Duvall
- 2 Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee
| | - Colleen M Brophy
- 1 Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee.,3 VA Tennessee Valley Healthcare System, Nashville, Tennessee
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Schroder J, Zethner-Moller R, Bové KB, Mygind ND, Hasbak P, Michelsen MM, Gustafsson I, Kastrup J, Prescott E. Protein biomarkers and coronary microvascular dilatation assessed by rubidium-82 PET in women with angina pectoris and no obstructive coronary artery disease. Atherosclerosis 2018; 275:319-327. [PMID: 29981522 DOI: 10.1016/j.atherosclerosis.2018.06.864] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 06/06/2018] [Accepted: 06/15/2018] [Indexed: 12/21/2022]
Abstract
BACKGROUND AND AIMS While a plethora of biomarkers have been shown to be associated with coronary artery disease, studies assessing biomarkers in coronary microvascular dysfunction (CMD) are few. We investigated associations between cardiovascular protein biomarkers and non-endothelium dependent CMD assessed by positron emission tomography (PET). METHODS In 97 women with angina pectoris and no significant obstructive coronary artery disease (<50% stenosis on invasive coronary angiography), CMD was defined as myocardial blood flow reserve (MBFR) < 2.5 by rubidium-82 PET. Blood samples were analyzed with a cardiovascular disease proteomic panel encompassing 92 biomarkers. The relation between MBFR and biomarkers was evaluated with age-adjusted regression analysis. RESULTS Median age was 62 years (range 31-79), median MBFR was 2.7 (range 1.2-4.7) and 32% had non-endothelium dependent CMD (MBFR<2.5). Four biomarkers were significantly correlated with MBFR: Galectin-4 (Gal4, p = 0.008), growth differentiation factor 15 (GDF15, p = 0.026), tissue-type plasminogen activator (tPA, p = 0.030) and von Willebrand factor (vWF, p = 0.018), while 12 biomarkers showed a trend for correlation (0.05 ≤ p < 0.15). Of the 16 identified biomarkers, 10 are involved in pro-inflammatory pathways. CONCLUSIONS In a panel of 92 cardiovascular protein biomarkers, 4 were significantly associated with non-endothelium dependent CMD in women: Gal4, GDF15, tPA and vWF, suggesting that inflammatory status and coagulation changes are associated with impaired microvascular dilatation. Further confirmatory studies are needed to corroborate these findings.
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Affiliation(s)
- Jakob Schroder
- Department of Cardiology, Bispebjerg Hospital, University of Copenhagen, Copenhagen, Denmark.
| | - Rikke Zethner-Moller
- Department of Cardiology, Bispebjerg Hospital, University of Copenhagen, Copenhagen, Denmark
| | - Kira Bang Bové
- Department of Cardiology, Bispebjerg Hospital, University of Copenhagen, Copenhagen, Denmark
| | - Naja Dam Mygind
- Department of Cardiology, Bispebjerg Hospital, University of Copenhagen, Copenhagen, Denmark; Department of Cardiology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Philip Hasbak
- Department of Clinical Physiology, Nuclear Medicine & PET and Cluster for Molecular Imaging, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Marie Mide Michelsen
- Department of Cardiology, Bispebjerg Hospital, University of Copenhagen, Copenhagen, Denmark
| | - Ida Gustafsson
- Department of Cardiology, Hvidovre Hospital, University of Copenhagen, Copenhagen, Denmark
| | - Jens Kastrup
- Department of Cardiology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Eva Prescott
- Department of Cardiology, Bispebjerg Hospital, University of Copenhagen, Copenhagen, Denmark
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Mirabegron, a β 3-adrenoceptor agonist reduced platelet aggregation through cyclic adenosine monophosphate accumulation. Eur J Pharmacol 2018; 829:79-84. [PMID: 29654782 DOI: 10.1016/j.ejphar.2018.04.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 04/05/2018] [Accepted: 04/09/2018] [Indexed: 11/22/2022]
Abstract
Mirabegron is a β3-adrenoceptor agonist and released on the marked for the treatment of overactive bladder. Because mirabegron is the only β3-adrenoceptor agonist available and substances that increase the levels of cyclic adenosine monophosphate (cAMP) inhibit platelet activity, we tested the hypothesis that mirabegron could have antiplatelet activity. Collagen- and thrombin induced platelet aggregation, thromboxane B2 (TXB2) and cyclic nucleotides quantification and calcium (Ca2+) mobilization were determined in the absence and presence of mirabegron in human washed platelets. Our results revealed that mirabegron (10-300 µM) produced significant inhibitions on platelet aggregation induced by collagen- or thrombin, accompanied by greater intracellular levels of cAMP. The β3-adrenoceptor antagonist L 748,337 (1 µM) and the adenylate cyclase inhibitor, SQ 22,536 (100 µM) reversed the inhibition induced by mirabegron in thrombin-stimulated platelets. The selective antagonists for β1-and β2-adrenoceptors, atenolol and ICI 117,551 (3 µM), respectively did not interfere on the inhibition induced by mirabegron. In Fluo-4 loaded platelets, mirabegron reduced the total and intracellular Ca2+ levels. Pre-incubation with mirabegron almost abolished the levels of TXB2. Mirabegron did not augment the intracellular levels of cyclic guanosine monophosphate. In conclusion, mirabegron inhibited human platelet aggregation through cAMP accumulation, thus suggesting that substances that activate β3-adrenoceptor could be beneficial as adjuvant antiplatelet therapy.
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Lindman J, Khammy MM, Lundegaard PR, Aalkjær C, Jepps TA. Microtubule Regulation of Kv7 Channels Orchestrates cAMP-Mediated Vasorelaxations in Rat Arterial Smooth Muscle. Hypertension 2017; 71:336-345. [PMID: 29279314 DOI: 10.1161/hypertensionaha.117.10152] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Revised: 09/01/2017] [Accepted: 11/29/2017] [Indexed: 11/16/2022]
Abstract
Microtubules can regulate GPCR (G protein-coupled receptor) signaling in various cell types. In vascular smooth muscle, activation of the β-adrenoceptor leads to production of cAMP to mediate a vasorelaxation. Little is known about the role of microtubules in smooth muscle, and given the importance of this pathway in vascular smooth muscle cells, we investigated the role of microtubule stability on β-adrenoceptor signaling in rat renal and mesenteric arteries. In isometric tension experiments, incubation with the microtubule inhibitors colchicine and nocodazole enhanced isoprenaline-mediated relaxations of renal and mesenteric arteries that the microtubule stabilizer, paclitaxel, prevented. Sharp microelectrode experiments showed that colchicine treatment caused increased hyperpolarization of mesenteric artery segments in response to isoprenaline. Application of the Kv7 channel blocker, XE991, attenuated the effect of colchicine on isoprenaline relaxations, whereas iberiotoxin-a BKCa channel blocker-had no effect. In addition, colchicine improved the relaxations to the Kv7.2 to 7.5 activator, S-1, in both renal and mesenteric artery segments compared with dimethyl sulfoxide incubation. We determined that increased mesenteric artery myocytes treated with colchicine showed increased Kv7.4 membrane expression, but Western blot analysis showed no change in total Kv7.4 protein. This study is the first to show microtubule disruption improves the β-adrenoceptor-mediated relaxations of mesenteric and renal arteries and determine this enhancement to be because of increased membrane expression of the Kv7 voltage-gated potassium channels.
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Affiliation(s)
- Johanna Lindman
- From the Department of Biomedical Sciences, Ion Channels Group, University of Copenhagen, Denmark (J.L., M.M.K., P.R.L., C.A., T.A.J.); and Department of Biomedicine, Aarhus University, Denmark (M.M.K., C.A.)
| | - Makhala M Khammy
- From the Department of Biomedical Sciences, Ion Channels Group, University of Copenhagen, Denmark (J.L., M.M.K., P.R.L., C.A., T.A.J.); and Department of Biomedicine, Aarhus University, Denmark (M.M.K., C.A.)
| | - Pia R Lundegaard
- From the Department of Biomedical Sciences, Ion Channels Group, University of Copenhagen, Denmark (J.L., M.M.K., P.R.L., C.A., T.A.J.); and Department of Biomedicine, Aarhus University, Denmark (M.M.K., C.A.)
| | - Christian Aalkjær
- From the Department of Biomedical Sciences, Ion Channels Group, University of Copenhagen, Denmark (J.L., M.M.K., P.R.L., C.A., T.A.J.); and Department of Biomedicine, Aarhus University, Denmark (M.M.K., C.A.)
| | - Thomas A Jepps
- From the Department of Biomedical Sciences, Ion Channels Group, University of Copenhagen, Denmark (J.L., M.M.K., P.R.L., C.A., T.A.J.); and Department of Biomedicine, Aarhus University, Denmark (M.M.K., C.A.).
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11
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Suffredini DA, Li Y, Xu W, Moayeri M, Leppla S, Fitz Y, Cui X, Eichacker PQ. Shock and lethality with anthrax edema toxin in rats are associated with reduced arterial responsiveness to phenylephrine and are reversed with adefovir. Am J Physiol Heart Circ Physiol 2017; 313:H946-H958. [PMID: 28887331 DOI: 10.1152/ajpheart.00285.2017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Revised: 08/22/2017] [Accepted: 08/24/2017] [Indexed: 12/18/2022]
Abstract
Although edema toxin (ETx) and lethal toxin (LTx) contribute to Bacillus anthracis shock and lethality, the mechanisms underlying their cardiovascular effects are unclear. We have previously shown that ETx but not LTx inhibited phenylephrine-stimulated contraction of aortic rings prepared from healthy rats and that adefovir, a selective inhibitor of ETx cAMP production, blocked this effect. Here, we examined arterial function in rats that received 24-h ETx or LTx infusions. Compared with control rats, ETx reduced mean arterial pressure (MAP) and survival over 48 h (P ≤ 0.0003) and increased plasma cAMP at 4, 24, and 48 h (P < 0.0001) and nitric oxide (NO) at 24 and 48 h (P ≤ 0.01). Compared with control animals, at 24- and 48-h phenylephrine stimulation of aortic rings from ETx animals produced decreased maximal contractile force (MCF; P = 0.05 and 0.006) and in vivo phenylephrine infusion in ETx animals produced decreased proportional increases in MAP (P < 0.0001 and P = 0.05). In ETx-treated animals, compared with placebo-treated animals, adefovir treatment prevented all lethality (P = 0.01), increased MAP (P ≤ 0.0001), decreased plasma and aortic tissue cAMP at 24 and 48 h, respectively (P ≤ 0.03), and plasma NO at both times (P ≤ 0.004), and increased phenylephrine-stimulated increases in MCF in aortic rings and MAP in vivo at 48 h (P = 0.02). LTx decreased MAP and survival also, but it did not alter the response to phenylephrine of MCF in aortic rings prepared from LTx animals or of MAP in vivo. In conclusion, in rats, hypotension and lethality are associated with reduced arterial contractile function with ETx but not LTx and adefovir improves ETx-induced hypotension and lethality.NEW & NOTEWORTHY The most important aspects of the present study are the findings that 1) in vivo challenge with anthrax edema but not lethal toxin depresses arterial contractile function measured both ex vivo and in vivo and 2) adefovir inhibits the effects of edema toxin on arterial hypotension and improves survival with lethal dose of edema toxin challenge.
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Affiliation(s)
- Dante A Suffredini
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland; and
| | - Yan Li
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland; and
| | - Wanying Xu
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland; and
| | - Mahtab Moayeri
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
| | - Stephen Leppla
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
| | - Yvonne Fitz
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland; and
| | - Xizhong Cui
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland; and
| | - Peter Q Eichacker
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland; and
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López-Canales OA, Castillo-Hernandez MC, Vargas-Robles H, Rios A, López-Canales JS, Escalante B. Role of adenylyl cyclase in reduced β-adrenoceptor-mediated vasorelaxation during maturation. ACTA ACUST UNITED AC 2017; 49:S0100-879X2016000700605. [PMID: 27383122 PMCID: PMC4942227 DOI: 10.1590/1414-431x20165285] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Accepted: 05/06/2016] [Indexed: 11/25/2022]
Abstract
Beta-adrenergic receptor (βAR)-dependent blood vessel relaxation is impaired in older animals and G protein activation has been suggested as the causative mechanism. Here, we investigated the role of βAR subtypes (β1AR, β2AR, and β3AR) and cAMP in maturation-dependent vasorelaxation impairment. Aortic rings from 15 Sprague-Dawley male rats (3 or 9 weeks old) were harvested and left intact or denuded of the endothelium. Vascular relaxation in aortic rings from younger and older groups was compared in the presence of βAR subtype agonists and antagonists along with cAMP and cGMP antagonists. Isolated aortic rings were used to evaluate relaxation responses, protein expression was evaluated by western blot or real time PCR, and metabolites were measured by ELISA. Expression of βAR subtypes and adenylyl cyclase was assessed, and cAMP activity was measured in vascular tissue from both groups. Isoproterenol- and BRL744-dependent relaxation in aortic rings with and without endothelium from 9-week-old rats was impaired compared with younger rats. The β1AR antagonist CGP20712A (10-7 M) did not affect isoproterenol or BRL744-dependent relaxation in arteries from either group. The β2AR antagonist ICI-118,551 (10-7 M) inhibited isoproterenol-dependent aortic relaxation in both groups. The β3AR antagonist SR59230A (10-7 M) inhibited isoproterenol- and BRL744-dependent aortic ring relaxation in younger but not in older rats. All βAR subtypes were expressed in both groups, although β3AR expression was lower in the older group. Adenylyl cyclase (SQ 22536) or protein kinase A (H89) inhibitors prevented isoproterenol-induced relaxation in younger but not in older rats. Production of cAMP was reduced in the older group. Adenylyl cyclase III and RyR3 protein expression was higher in the younger group. In conclusion, altered expression of β3AR and adenylyl cyclase III may be responsible for reduced cAMP production in the older group.
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Affiliation(s)
- O A López-Canales
- Molecular Biomedicine Department, Center of Research and Advanced Studies, Unidad Zacatenco, Mexico City, Mexico
| | - M C Castillo-Hernandez
- Pharmacology Department, Superior School of Medicine, Polytechnic National Institute, Mexico City, Mexico
| | - H Vargas-Robles
- Molecular Biomedicine Department, Center of Research and Advanced Studies, Unidad Zacatenco, Mexico City, Mexico
| | - A Rios
- Center of Research and Advanced Studies, Monterrey, Nuevo León, Mexico
| | - J S López-Canales
- Pharmacology Department, Superior School of Medicine, Polytechnic National Institute, Mexico City, Mexico.,Perinatology National Institute "Isidro Espinosa de los Reyes", Mexico City, Mexico
| | - B Escalante
- Center of Research and Advanced Studies, Monterrey, Nuevo León, Mexico
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13
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Shim HS, Kim JS, Kim MG. Comparative Analysis of the Combined Therapeutic Effects of Lipoprostaglandin E 1 on Sudden Idiopathic Sensorineural Hearing Loss. J Audiol Otol 2017; 21:33-38. [PMID: 28417106 PMCID: PMC5392007 DOI: 10.7874/jao.2017.21.1.33] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Revised: 07/03/2016] [Accepted: 07/04/2016] [Indexed: 12/03/2022] Open
Abstract
Background and Objectives Viral and vascular disorders are considered to be a major cause of idiopathic sudden sensorineural hearing loss (ISSNHL). Lipoprostaglandin E1 (lipo-PGE1) has vasodilating activity and has been used to treat ISSNHL. The purpose of this study was to determine the specific therapeutic effects of lipo-PGE1 and compare them to other treatment modalities for ISSNHL. Subjects and Methods The study group had 1,052 patients diagnosed with ISSNHL. All were treated with steroid, carbogen inhalation, stellate ganglion block (SGB), or PGE1. The CP group (steroid, carbogen inhalation, and PGE1 injection; 288 patients) was treated with lipo-PGE1 and carbogen inhalation, the CS group (steroid, carbogen inhalation, and stellate ganglion block; 232 patients) with steroid, carbogen inhalation, and SGB, the C group (steroid and carbogen inhalation; 284 patients) with steroid and carbogen, and the control group (steroid only; 248 patients) with steroid only. Patients in the groups receiving lipo-PGE1 received a continuous infusion of 10 µL lipo-PGE1. Results The overall recovery rate after treatment was 52.2%, and recovery rates by group were 67.7% in the CP group, 54.3% in the CS group, 52.1% in the C group, and 32.2% in the control group. Therefore, the therapeutic results in groups treated with lipo-PGE1 were better than results in other groups. The difference was statistically significant. Conclusions The study results suggested that the CP group received effective treatment modalities for ISSNHL. The combined therapy of lipo-PGE1 with carbogen inhalation in patients with ISSNHL was more beneficial than other treatment modalities.
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Affiliation(s)
- Haeng Seon Shim
- Department of Anesthesiology and Pain Medicine, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine, Changwon, Korea
| | - Joon Soo Kim
- Department of Neurosurgery, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine, Changwon, Korea
| | - Myung Gu Kim
- Department of Otorhinolaryngology-Head and Neck Surgery, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine, Changwon, Korea
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Chen C, Wei J, AlBadri A, Zarrini P, Bairey Merz CN. Coronary Microvascular Dysfunction - Epidemiology, Pathogenesis, Prognosis, Diagnosis, Risk Factors and Therapy. Circ J 2016; 81:3-11. [PMID: 27904032 PMCID: PMC8607842 DOI: 10.1253/circj.cj-16-1002] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 07/20/2023]
Abstract
Angina has traditionally been thought to be caused by obstructive coronary artery disease (CAD). However, a substantial number of patients with angina are found to not have obstructive CAD when undergoing coronary angiography. A significant proportion of these patients have coronary microvascular dysfunction (CMD), characterized by heightened sensitivity to vasoconstrictor stimuli and limited microvascular vasodilator capacity. With the advent of non-invasive and invasive techniques, the coronary microvasculature has been more extensively studied in the past 2 decades. CMD has been identified as a cause of cardiac ischemia, in addition to traditional atherosclerotic disease and vasospastic disease. CMD can occur alone or in the presence obstructive CAD. CMD shares many similar risk factors with macrovascular CAD. Diagnosis is achieved through detection of an attenuated response of coronary blood flow in response to vasodilatory agents. Imaging modalities such as cardiovascular magnetic resonance, positron emission tomography, and transthoracic Doppler echocardiography have become more widely used, but have not yet completely replaced the traditional intracoronary vasoreactivity testing. Treatment of CMD starts with lifestyle modification and risk factor control. The use of traditional antianginal, antiatherosclerotic medications and some novel agents may be beneficial; however, clinical trials are needed to assess the efficacy of the pharmacologic and non-pharmacologic therapeutic modalities. In addition, studies with longer-term follow-up are needed to determine the prognostic benefits of these agents. We review the epidemiology, prognosis, pathogenesis, diagnosis, risk factors and current therapies for CMD.
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Affiliation(s)
- Cheng Chen
- Barbra Streisand Women's Heart Center, Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center
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15
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Ooms M, Attili B, Celen S, Koole M, Verbruggen A, Van Laere K, Bormans G. [18F]JNJ42259152 binding to phosphodiesterase 10A, a key regulator of medium spiny neuron excitability, is altered in the presence of cyclic AMP. J Neurochem 2016; 139:897-906. [DOI: 10.1111/jnc.13855] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 08/29/2016] [Accepted: 09/19/2016] [Indexed: 12/18/2022]
Affiliation(s)
- Maarten Ooms
- Laboratory for Radiopharmacy; Department of Pharmaceutical and Pharmacological Sciences KU Leuven; Leuven Belgium
| | - Bala Attili
- Laboratory for Radiopharmacy; Department of Pharmaceutical and Pharmacological Sciences KU Leuven; Leuven Belgium
| | - Sofie Celen
- Laboratory for Radiopharmacy; Department of Pharmaceutical and Pharmacological Sciences KU Leuven; Leuven Belgium
| | - Michel Koole
- Division of Nuclear Medicine; KU Leuven and University Hospital Leuven; Leuven Belgium
| | - Alfons Verbruggen
- Laboratory for Radiopharmacy; Department of Pharmaceutical and Pharmacological Sciences KU Leuven; Leuven Belgium
| | - Koen Van Laere
- Division of Nuclear Medicine; KU Leuven and University Hospital Leuven; Leuven Belgium
| | - Guy Bormans
- Laboratory for Radiopharmacy; Department of Pharmaceutical and Pharmacological Sciences KU Leuven; Leuven Belgium
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16
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Li Y, Cui X, Xu W, Ohanjanian L, Sampath-Kumar H, Suffredini D, Moayeri M, Leppla S, Fitz Y, Eichacker PQ. Nitric oxide production contributes to Bacillus anthracis edema toxin-associated arterial hypotension and lethality: ex vivo and in vivo studies in the rat. Am J Physiol Heart Circ Physiol 2016; 311:H781-93. [PMID: 27448553 DOI: 10.1152/ajpheart.00163.2016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Accepted: 07/19/2016] [Indexed: 01/26/2023]
Abstract
We showed previously that Bacillus anthracis edema toxin (ET), comprised of protective antigen (PA) and edema factor (EF), inhibits phenylephrine (PE)-induced contraction in rat aortic rings and these effects are diminished in endothelial-denuded rings. Therefore, employing rat aortic ring and in vivo models, we tested the hypothesis that nitric oxide (NO) contributes to ET's arterial effects. Compared with rings challenged with PA alone, ET (PA + EF) reduced PE-stimulated maximal contractile force (MCF) and increased the PE concentration producing 50% MCF (EC50) (P < 0.0001). Compared with placebo, l-nitro-arginine methyl-ester (l-NAME), an NO synthase (NOS) inhibitor, reduced ET's effects on MCF and EC50 in patterns that approached or were significant (P = 0.06 and 0.03, respectively). In animals challenged with 24-h ET infusions, l-NAME (0.5 or 1.0 mg·kg(-1)·h(-1)) coadministration increased survival to 17 of 28 animals (60.7%) compared with 4 of 27 (14.8%) given placebo (P = 0.01). Animals receiving l-NAME but no ET all survived. Compared with PBS challenge, ET increased NO levels at 24 h and l-NAME decreased these increases (P < 0.0001). ET infusion decreased mean arterial blood pressure (MAP) in placebo and l-NAME-treated animals (P < 0.0001) but l-NAME reduced decreases in MAP with ET from 9 to 24 h (P = 0.03 for the time interaction). S-methyl-l-thiocitrulline, a selective neuronal NOS inhibitor, had effects in rings and, at a high dose in vivo models, comparable to l-NAME, whereas N'-[3-(aminomethyl)benzyl]-acetimidamide, a selective inducible NOS inhibitor, did not. NO production contributes to ET's arterial relaxant, hypotensive, and lethal effects in the rat.
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Affiliation(s)
- Yan Li
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland; and
| | - Xizhong Cui
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland; and
| | - Wanying Xu
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland; and
| | - Lernik Ohanjanian
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland; and
| | - Hanish Sampath-Kumar
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland; and
| | - Dante Suffredini
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland; and
| | - Mahtab Moayeri
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
| | - Stephen Leppla
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
| | - Yvonne Fitz
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland; and
| | - Peter Q Eichacker
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland; and
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17
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Flacco N, Segura V, Perez-Aso M, Estrada S, Seller JF, Jiménez-Altayó F, Noguera MA, D'Ocon P, Vila E, Ivorra MD. Different β-adrenoceptor subtypes coupling to cAMP or NO/cGMP pathways: implications in the relaxant response of rat conductance and resistance vessels. Br J Pharmacol 2014; 169:413-25. [PMID: 23373597 DOI: 10.1111/bph.12121] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Revised: 01/07/2013] [Accepted: 01/18/2013] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND AND PURPOSE To analyse the relative contribution of β1 -, β2 - and β3 -adrenoceptors (Adrb) to vasodilatation in conductance and resistance vessels, assessing the role of cAMP and/or NO/cGMP signalling pathways. EXPERIMENTAL APPROACH Rat mesenteric resistance artery (MRA) and aorta were used to analyse the Adrb expression by real-time-PCR and immunohistochemistry, and for the pharmacological characterization of Adrb-mediated activity by wire myography and tissue nucleotide accumulation. KEY RESULTS The mRNAs and protein for all Adrb were identified in endothelium and/or smooth muscle cells (SMCs) in both vessels. In MRA, Adrb1 signalled through cAMP, Adrb3 through both cAMP and cGMP, but Adrb2, did not activate nucleotide formation; isoprenaline relaxation was inhibited by propranolol (β1 , β2 ), CGP20712A (β1 ), and SQ22536 (adenylyl cyclase inhibitor), but not by ICI118,551 (β2 ), SR59230A (β3 ), ODQ (soluble guanylyl cyclase inhibitor), L-NAME or endothelium removal. In aorta, Adrb1 signalled through cAMP, while β2 - and β3 -subtypes through cGMP; isoprenaline relaxation was inhibited by propranolol, ICI118,551, ODQ, L-NAME, and to a lesser extent, by endothelium removal. CL316243 (β3 -agonist) relaxed aorta, but not MRA. CONCLUSION AND IMPLICATION Despite all three Adrb subtypes being found in both vessels, Adrb1, located in SMCs and acting through the adenylyl cyclase/cAMP pathway, are primarily responsible for vasodilatation in MRA. However, Adrb-mediated vasodilatation in aorta is driven by endothelial Adrb2 and Adrb3, but also by the Adrb2 present in SMCs, and is coupled to the NO/cGMP pathway. These results could help to understand the different physiological roles played by Adrb signalling in regulating conductance and resistance vessels.
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Affiliation(s)
- N Flacco
- Departament de Farmacologia, Facultat de Farmacia, Universitat de Valencia, Burjassot, Spain
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Narang D, Kerr PM, Lunn SE, Beaudry R, Sigurdson J, Lalies MD, Hudson AL, Light PE, Holt A, Plane F. Modulation of Resistance Artery Tone by the Trace Amine β-Phenylethylamine: Dual Indirect Sympathomimetic and α1-Adrenoceptor Blocking Actions. J Pharmacol Exp Ther 2014; 351:164-71. [DOI: 10.1124/jpet.114.216523] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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19
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Cabral PHB, de Morais Campos R, Fonteles MC, Santos CF, Leal Cardoso JH, do Nascimento NRF. Effects of the essential oil of Croton zehntneri and its major components, anethole and estragole, on the rat corpora cavernosa. Life Sci 2014; 112:74-81. [PMID: 25084123 DOI: 10.1016/j.lfs.2014.07.022] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Revised: 07/10/2014] [Accepted: 07/15/2014] [Indexed: 10/25/2022]
Abstract
AIMS The effects of the essential oil of Croton zehntneri (EOCz) and its major components anethole, estragole and methyl eugenol were evaluated in phenylephrine precontracted rat corpora cavernosa (RCC). MAIN METHODS RCC strips were mounted in 5 ml organ baths for isometric recordings of tension, precontracted with 10 μM phenylephrine and exposed to test drugs. KEY FINDINGS All major compounds relaxed RCC. The order of potency was estragole>anethole>methyl eugenol. The maximal relaxation to EOCz and methyl eugenol was 62.67% (IC50 of 1.67 μM) and 45.8% (IC50 of 1.7 μM), respectively. Estragole relaxed RCC with an IC50 of 0.6 μM (maximal relaxation-76.6%). The maximal relaxation to estragole was significantly reduced by L-NAME (43.46%-IC50 of 1.4 μM), ODQ (53.11%-IC50 of 0.83 μM) and indomethacin (24.41%-IC50 of 1.3 μM). On the other hand, anethole relaxed RCC by 66.73% (IC50 of 0.96 μM) and this relaxation was blunted by indomethacin (35.65%-IC50 of 1.6 μM). Both estragole and anethole increased the relaxation achieved upon electrical stimulation. Both compounds increased the levels of cAMP (estragole by 3-fold and anethole by 2-fold when compared to controls). Estragole also increased the levels of cGMP (0.5-fold). SIGNIFICANCE The higher potency of these compounds to relax corpora cavernosa smooth muscle may form the pharmacological basis for the use of such substances as leading compounds in the search of alternative treatments of erectile dysfunction.
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Affiliation(s)
- Pedro Henrique Bezerra Cabral
- Ceará State University, Superior Institute of Biomedicine, Laboratory of Renal and Cardiovascular Pharmacology, Fortaleza, Ceará, Brazil
| | - Rafael de Morais Campos
- Ceará State University, Superior Institute of Biomedicine, Laboratory of Renal and Cardiovascular Pharmacology, Fortaleza, Ceará, Brazil
| | - Manassés Claudino Fonteles
- Ceará State University, Superior Institute of Biomedicine, Laboratory of Renal and Cardiovascular Pharmacology, Fortaleza, Ceará, Brazil
| | - Cláudia Ferreira Santos
- Ceará State University, Superior Institute of Biomedicine, Laboratory of Renal and Cardiovascular Pharmacology, Fortaleza, Ceará, Brazil
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Li H, Zuccolo J, Kem DC, Zillner C, Lee J, Smith K, James JA, Cunningham MW, Yu X. Implications of a vasodilatory human monoclonal autoantibody in postural hypotension. J Biol Chem 2013; 288:30734-30741. [PMID: 24043632 DOI: 10.1074/jbc.m113.477869] [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] [Indexed: 11/06/2022] Open
Abstract
Functional autoantibodies to the autonomic receptors are increasingly recognized in the pathophysiology of cardiovascular diseases. To date, no human activating monoclonal autoantibodies to these receptors have been available. In this study, we describe for the first time a β2-adrenergic receptor (β2AR)-activating monoclonal autoantibody (C5F2) produced from the lymphocytes of a patient with idiopathic postural hypotension. C5F2, an IgG3 isotype, recognizes an epitope in the N terminus of the second extracellular loop (ECL2) of β2AR. Surface plasmon resonance analysis revealed high binding affinity for the β2AR ECL2 peptide. Immunoblotting and immunofluorescence demonstrated specific binding to β2AR in H9c2 cardiomyocytes, CHO cells expressing human β2AR, and rat aorta. C5F2 stimulated cyclic AMP production in β2AR-transfected CHO cells and induced potent dilation of isolated rat cremaster arterioles, both of which were specifically blocked by the β2AR-selective antagonist ICI-118551 and by the β2AR ECL2 peptide. This monoclonal antibody demonstrated sufficient activity to produce postural hypotension in its host. Its availability provides a unique opportunity to identify previously unrecognized causes and new pharmacological management of postural hypotension and other cardiovascular diseases.
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Affiliation(s)
- Hongliang Li
- From the Departments of Medicine and; the Oklahoma City Veterans Affairs Medical Center, and
| | - Jonathan Zuccolo
- Microbiology and Immunology, University of Oklahoma Health Sciences Center
| | - David C Kem
- From the Departments of Medicine and; the Oklahoma City Veterans Affairs Medical Center, and
| | - Caitlin Zillner
- From the Departments of Medicine and; the Oklahoma City Veterans Affairs Medical Center, and
| | | | - Kenneth Smith
- the Arthritis and Clinical Immunology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104
| | - Judith A James
- From the Departments of Medicine and; Microbiology and Immunology, University of Oklahoma Health Sciences Center,; the Arthritis and Clinical Immunology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104
| | | | - Xichun Yu
- From the Departments of Medicine and; the Oklahoma City Veterans Affairs Medical Center, and.
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Roberts OL, Kamishima T, Barrett-Jolley R, Quayle JM, Dart C. Exchange protein activated by cAMP (Epac) induces vascular relaxation by activating Ca2+-sensitive K+ channels in rat mesenteric artery. J Physiol 2013; 591:5107-23. [PMID: 23959673 DOI: 10.1113/jphysiol.2013.262006] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Vasodilator-induced elevation of intracellular cyclic AMP (cAMP) is a central mechanism governing arterial relaxation but is incompletely understood due to the diversity of cAMP effectors. Here we investigate the role of the novel cAMP effector exchange protein directly activated by cAMP (Epac) in mediating vasorelaxation in rat mesenteric arteries. In myography experiments, the Epac-selective cAMP analogue 8-pCPT-2-O-Me-cAMP-AM (5 μM, subsequently referred to as 8-pCPT-AM) elicited a 77.6 ± 7.1% relaxation of phenylephrine-contracted arteries over a 5 min period (mean ± SEM; n = 6). 8-pCPT-AM induced only a 16.7 ± 2.4% relaxation in arteries pre-contracted with high extracellular K(+) over the same time period (n = 10), suggesting that some of Epac's relaxant effect relies upon vascular cell hyperpolarization. This involves Ca(2+)-sensitive, large-conductance K(+) (BK(Ca)) channel opening as iberiotoxin (100 nM) significantly reduced the ability of 8-pCPT-AM to reverse phenylephrine-induced contraction (arteries relaxed by only 35.0 ± 8.5% over a 5 min exposure to 8-pCPT-AM, n = 5; P < 0.05). 8-pCPT-AM increased Ca(2+) spark frequency in Fluo-4-AM-loaded mesenteric myocytes from 0.045 ± 0.008 to 0.103 ± 0.022 sparks s(-1) μm(-1) (P < 0.05) and reversibly increased both the frequency (0.94 ± 0.25 to 2.30 ± 0.72 s(-1)) and amplitude (23.9 ± 3.3 to 35.8 ± 7.7 pA) of spontaneous transient outward currents (STOCs) recorded in isolated mesenteric myocytes (n = 7; P < 0.05). 8-pCPT-AM-activated STOCs were sensitive to iberiotoxin (100 nM) and to ryanodine (30 μM). Current clamp recordings of isolated myocytes showed a 7.9 ± 1.0 mV (n = 10) hyperpolarization in response to 8-pCPT-AM that was sensitive to iberiotoxin (n = 5). Endothelial disruption suppressed 8-pCPT-AM-mediated relaxation in phenylephrine-contracted arteries (24.8 ± 4.9% relaxation after 5 min of exposure, n = 5; P < 0.05), as did apamin and TRAM-34, blockers of Ca(2+)-sensitive, small- and intermediate-conductance K(+) (SK(Ca) and IK(Ca)) channels, respectively, and N(G)-nitro-L-arginine methyl ester, an inhibitor of nitric oxide synthase (NOS). In Fluo-4-AM-loaded mesenteric endothelial cells, 8-pCPT-AM induced a sustained increase in global Ca(2+). Our data suggest that Epac hyperpolarizes smooth muscle by (1) increasing localized Ca(2+) release from ryanodine receptors (Ca(2+) sparks) to activate BK(Ca) channels, and (2) endothelial-dependent mechanisms involving the activation of SK(Ca)/IK(Ca) channels and NOS. Epac-mediated smooth muscle hyperpolarization will limit Ca(2+) entry via voltage-sensitive Ca(2+) channels and represents a novel mechanism of arterial relaxation.
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Affiliation(s)
- Owain Llŷr Roberts
- C. Dart: Institute of Integrative Biology, University of Liverpool, Crown Street, Liverpool L69 7ZB, UK.
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Osgood MJ, Flynn CR, Komalavilas P, Brophy C. Cell-permeant peptide inhibitors of vasospasm and intimal hyperplasia. Vascular 2012; 21:46-53. [PMID: 23104826 DOI: 10.1258/vasc.2011.201203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Outcomes from vein graft bypass are limited by graft failure, leading causes of which include intimal hyperplasia and vasospasm. Intimal hyperplasia remains the most common cause of graft failure, but no therapeutic modalities have been shown to prevent intimal hyperplasia in humans. The small heat shock proteins are a class of naturally occurring proteins in vascular smooth muscle. These proteins have an integral role in maintenance of vascular tone and in cellular defense against various stressors. Transduction domains have enabled intracellular therapeutic delivery of peptide analogs of heat shock proteins, as well as peptide inhibitors of the kinases that phosphorylate these proteins. These cell-permeant peptides have been shown to prevent vasospasm and intimal hyperplasia in vitro. Since vascular bypass using vein grafts is analogous to autologous organ transplantation, ex vivo treatment of the vein graft with cell-permeant peptide inhibitors of vasospasm and intimal hyperplasia prior to implantation provides a unique opportunity for targeted treatment of the graft to improve patency.
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Affiliation(s)
- Michael J Osgood
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN, USA.
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Yu X, Stavrakis S, Hill MA, Huang S, Reim S, Li H, Khan M, Hamlett S, Cunningham MW, Kem DC. Autoantibody activation of beta-adrenergic and muscarinic receptors contributes to an "autoimmune" orthostatic hypotension. JOURNAL OF THE AMERICAN SOCIETY OF HYPERTENSION : JASH 2012; 6:40-7. [PMID: 22130180 PMCID: PMC3259269 DOI: 10.1016/j.jash.2011.10.003] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2011] [Revised: 10/04/2011] [Accepted: 10/07/2011] [Indexed: 01/25/2023]
Abstract
BACKGROUND Orthostatic hypotension (OH) is characterized by an abnormal autonomic response to upright posture. Activating autoantibodies to β1/2-adrenergic (AAβ1/2AR) and M2/3 muscarinic receptors (AAM2/3R) produce vasodilative changes in the vasculature that may contribute to OH. METHODS Immunoglobulin (Ig)G from 6 patients with idiopathic OH harboring autoantibodies and from 10 healthy control subjects were examined for: 1) β1AR and M2R activity with a perfused Purkinje fiber assay and PKA assay in H9c2 cells and 2) vasodilator β2AR and M3R activity using a pressurized cremaster resistance arteriole assay. Changes in IgG activity with and without propranolol, atropine, and L-NAME were used to estimate AAβAR, AAM2R, and AAM3R activation of their respective functions. RESULTS All six patients had elevated enzyme-linked immunosorbent assay titers to at least one of the receptors compared with controls. βAR-mediated contractility activity and M2R activity were increased in five of the six patients. IgG from all six patients produced a direct vasodilator effect on cremaster arterioles. βAR and nitric oxide synthase blockade led to near normalization of IgG-induced vasodilation. CONCLUSION AAβ1/2AR and AAM2/3R are present in some patients with idiopathic OH compatible with an in vivo effect. These autoantibodies and their cardiovascular effects provide new mechanistic insights into the pathophysiology of OH.
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Affiliation(s)
- Xichun Yu
- Heart Rhythm Institute, University of Oklahoma Health Sciences Center and VA Medical Center, Oklahoma City, Oklahoma, USA
- Endocrinology and the Harold Hamm Oklahoma Diabetes Center, Department of Medicine, University of Oklahoma Health Sciences Center and VA Medical Center, Oklahoma City, Oklahoma, USA
| | - Stavros Stavrakis
- Heart Rhythm Institute, University of Oklahoma Health Sciences Center and VA Medical Center, Oklahoma City, Oklahoma, USA
| | - Michael A. Hill
- Department of Medical Pharmacology and Physiology, Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri, USA
| | - Shijun Huang
- Endocrinology and the Harold Hamm Oklahoma Diabetes Center, Department of Medicine, University of Oklahoma Health Sciences Center and VA Medical Center, Oklahoma City, Oklahoma, USA
| | - Sean Reim
- Endocrinology and the Harold Hamm Oklahoma Diabetes Center, Department of Medicine, University of Oklahoma Health Sciences Center and VA Medical Center, Oklahoma City, Oklahoma, USA
| | - Hongliang Li
- Endocrinology and the Harold Hamm Oklahoma Diabetes Center, Department of Medicine, University of Oklahoma Health Sciences Center and VA Medical Center, Oklahoma City, Oklahoma, USA
| | - Muneer Khan
- Endocrinology and the Harold Hamm Oklahoma Diabetes Center, Department of Medicine, University of Oklahoma Health Sciences Center and VA Medical Center, Oklahoma City, Oklahoma, USA
| | - Sean Hamlett
- Endocrinology and the Harold Hamm Oklahoma Diabetes Center, Department of Medicine, University of Oklahoma Health Sciences Center and VA Medical Center, Oklahoma City, Oklahoma, USA
| | - Madeleine W. Cunningham
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | - David C. Kem
- Heart Rhythm Institute, University of Oklahoma Health Sciences Center and VA Medical Center, Oklahoma City, Oklahoma, USA
- Endocrinology and the Harold Hamm Oklahoma Diabetes Center, Department of Medicine, University of Oklahoma Health Sciences Center and VA Medical Center, Oklahoma City, Oklahoma, USA
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Altaweel L, Chen Z, Moayeri M, Cui X, Li Y, Su J, Fitz Y, Johnson S, Leppla SH, Purcell R, Eichacker PQ. Delayed treatment with W1-mAb, a chimpanzee-derived monoclonal antibody against protective antigen, reduces mortality from challenges with anthrax edema or lethal toxin in rats and with anthrax spores in mice. Crit Care Med 2011; 39:1439-47. [PMID: 21336113 DOI: 10.1097/ccm.0b013e3182120691] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE W1-mAb is a chimpanzee-derived monoclonal antibody to protective antigen that improved survival when administered before anthrax lethal toxin challenge in rats. To better define W1-mAb's efficacy for anthrax, we administered it after initiation of 24-hr infusions of edema toxin and lethal toxin either alone or together in rats or following anthrax spore challenge in mice. INTERVENTIONS W1-mAb or placebo treatment. METHODS AND MAIN RESULTS In toxin-challenged rats treated with placebo, survival rates were lower with edema toxin (500 μg/kg) compared to lethal toxin either alone (175 μg/kg) or with edema toxin (175 μg/kg each) (8%, 33%, and 32%, respectively), but the median time to death was longer (36, 11, and 9 hrs, respectively) (p ≤ .01 for all comparisons). W1-mAb administered up to 12 hrs after edema toxin and 6 hrs after lethal toxin increased survival and reduced hypotension (p ≤ .01). However, only administration of W1-mAb at 0 hrs improved these variables with lethal toxin and edema toxin together (p ≤ .0002). In C57BL/6J mice challenged with anthrax spores subcutaneously, compared to placebo treatment (0 of 15 animals survived), W1-mAb administered beginning 24 hrs after challenge increased survival (13 of 15 survived) (p ≤ .0001). CONCLUSION While rapidity of lethality may influence the effectiveness of delayed W1-mAb treatment, these rat and mouse studies provide a basis for further exploring this agent's usefulness for anthrax.
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Affiliation(s)
- Laith Altaweel
- Critical Care Medicine Department, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
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The relationship between the Trp 64 Arg polymorphism of the beta 3-adrenoceptor gene and idiopathic overactive bladder. Am J Obstet Gynecol 2011; 205:82.e10-4. [PMID: 21529759 DOI: 10.1016/j.ajog.2011.02.052] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2010] [Revised: 02/11/2011] [Accepted: 02/14/2011] [Indexed: 11/22/2022]
Abstract
OBJECTIVE The purpose of this study was to verify the association between the Trp 64 Arg polymorphism and idiopathic overactive bladder (OAB) syndrome. STUDY DESIGN A case-control study was conducted with 218 women. The case group consisted of 49 patients with OAB symptoms; the control group included 169 women without urinary symptoms. The studied polymorphism was detected by restriction fragment length polymorphism analysis. The χ(2) test was used to compare categoric data, with a significance level of 5%. Numeric data were compared with the use of the parametric t test or nonparametric Mann-Whitney U test. RESULTS The distribution of the polymorphism in the investigated women was digested homozygous T allele 69.75%, heterozygotes 29.8%, and homozygous A allele 0.45%. A comparison between the groups showed higher prevalence of the digested homozygous T allele genotype in women with OAB syndrome (P = .001). Multiple logistic regression analysis identified that a family history of OAB syndrome was an independent risk factor for OAB syndrome. CONCLUSION The Trp 64 Arg polymorphism was associated with OAB syndrome in the Brazilian population.
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Smani T, Calderon E, Rodriguez-Moyano M, Dominguez-Rodriguez A, Diaz I, Ordóñez A. Urocortin-2 induces vasorelaxation of coronary arteries isolated from patients with heart failure. Clin Exp Pharmacol Physiol 2011; 38:71-6. [PMID: 21105894 DOI: 10.1111/j.1440-1681.2010.05466.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
1. Urocortin-2 (Ucn2) is a vasoactive peptide belonging to the corticotrophin-releasing factor (CRF) family that has potent cardiovascular actions. It has been suggested that Ucn2 participates in the pathophysiology of heart failure. However, little is known about the mechanisms underlying the action of Ucn2 in human coronary arteries. The aim of the present study was to assess the effects of Ucn2 on the vascular tone of human coronary arteries dissected from heart failure patients. 2. Human coronary arteries were dissected from the hearts of patients subjected to orthotopic heart transplantation. Coronary arteries were obtained from 17 patients with heart failure due to dilated cardiomyopathy of ischaemic origin in Stage III-IV of the New York Heart Association classification. Changes in tone were measured in arterial rings using force transducers. 3. Application of increasing concentrations of Ucn2 (5-20 nmol/L) to arterial rings precontracted with agonists induced dose-dependent relaxation of the coronary artery, which was independent of endothelial cell activation. Furthermore, the inhibition of the adenylyl cyclase by MDL-12 (100 nmol/L) and protein kinase A (PKA) by H89 (1 μmol/L) prevented Ucn2-mediated relaxation of coronary artery rings. 4. The results of the present study suggest that, in heart failure patients, Ucn2 could be useful in modulating coronary artery circulation independent of endothelial integrity through mechanisms that involve adenylyl cyclase activation and PKA stimulation. The findings warrant further investigation of the role of Ucn2 in circulatory regulation and its potential therapeutic application in heart disease.
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Affiliation(s)
- Tarik Smani
- Institute of Biomedicine from Seville, Universitary Hospital of Virgen del Rocío, University of Seville, Spain.
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Perrino BA. Regulation of gastrointestinal motility by Ca2+/calmodulin-stimulated protein kinase II. Arch Biochem Biophys 2011; 510:174-81. [PMID: 21443856 DOI: 10.1016/j.abb.2011.03.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2010] [Revised: 03/15/2011] [Accepted: 03/21/2011] [Indexed: 12/30/2022]
Abstract
Gastrointestinal (GI) motility ultimately depends upon the contractile activity of the smooth muscle cells of the tunica muscularis. Integrated functioning of multiple tissues and cell types, including enteric neurons and interstitial cells of Cajal (ICC) is necessary to generate coordinated patterns of motor activity that control the movement of material through the digestive tract. The neurogenic mechanisms that govern GI motility patterns are superimposed upon intrinsic myogenic mechanisms regulating smooth muscle cell excitability. Several mechanisms regulate smooth muscle cell responses to neurogenic inputs, including the multifunctional Ca(2+)/calmodulin-stimulated protein kinase II (CaMKII). CaMKII can be activated by Ca(2+) transients from both extracellular and intracellular sources. Prolonging the activities of Ca(2+)-sensitive K(+) channels in the plasma membrane of GI smooth muscle cells is an important regulatory mechanism carried out by CaMKII. Phospholamban (PLN) phosphorylation by CaMKII activates the sarcoplasmic reticulum (SR) Ca(2+)-ATPase (SERCA), increasing both the rate of Ca(2+) clearance from the myoplasm and the frequency of localized Ca(2+) release events from intracellular stores. Overall, CaMKII appears to moderate GI smooth muscle cell excitability. Finally, transcription factor activities may be facilitated by the neutralization of HDAC4 by CaMKII phosphorylation, which may contribute to the phenotypic plasticity of GI smooth muscle cells.
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Affiliation(s)
- Brian A Perrino
- Department of Physiology and Cell Biology, Center of Biomedical Research Excellence, University of Nevada School of Medicine, Reno, 89557, USA.
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Kim MG, Jung YG, Eun YG. Effect of steroid, carbogen inhalation, and lipoprostaglandin E1 combination therapy for sudden sensorineural hearing loss. Am J Otolaryngol 2011; 32:91-5. [PMID: 20022673 DOI: 10.1016/j.amjoto.2009.10.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2009] [Revised: 10/06/2009] [Accepted: 10/20/2009] [Indexed: 01/01/2023]
Abstract
PURPOSE The purpose of this study was to evaluate the efficacy of combined therapy with steroid, carbogen inhalation, and lipoprostaglandin E(1) (lipo-PGE(1)) treatment and compare the results with other treatment modalities in patients with idiopathic sudden sensorineural hearing loss (ISSNHL). SUBJECTS AND METHODS The study group consisted of 670 patients diagnosed with unilateral ISSNHL. Two hundred patients (DCP group) were treated with steroid, lipo-PGE(1) and carbogen inhalation combination therapy, 194 patients (DC group) with steroid and carbogen inhalation, and 276 patients (D group) with steroid medication only. The therapeutic effects of the treatment groups were evaluated 2 months after treatment, using pure tone averages. Siegel's criteria for hearing improvement were used for the assessments. RESULTS The overall recovery rate after treatment was 57.5%. For each group, the recovery rate was as follows: 67.0% in the DCP group, 52.6% in the DC group, and 53.9% in the D group. The DCP group had a significantly better improvement rate than the other 2 groups. In addition, the DCP treatment was better than the other 2 groups for patients: less than 50 years of age, with an initial hearing loss less than 90 dB HL, had treatment started within 1 week from the onset of hearing loss, had tinnitus or an ascending type audiogram, and/or had no vertigo. CONCLUSION Steroid, lipo-PGE(1), and carbogen inhalation therapy was more effective than the other treatment modalities studied for patients with ISSNHL.
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An SS, Askovich PS, Zarembinski TI, Ahn K, Peltier JM, von Rechenberg M, Sahasrabudhe S, Fredberg JJ. A novel small molecule target in human airway smooth muscle for potential treatment of obstructive lung diseases: a staged high-throughput biophysical screening. Respir Res 2011; 12:8. [PMID: 21232113 PMCID: PMC3034681 DOI: 10.1186/1465-9921-12-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2010] [Accepted: 01/13/2011] [Indexed: 11/23/2022] Open
Abstract
Background A newly identified mechanism of smooth muscle relaxation is the interaction between the small heat shock protein 20 (HSP20) and 14-3-3 proteins. Focusing upon this class of interactions, we describe here a novel drug target screening approach for treating airflow obstruction in asthma. Methods Using a high-throughput fluorescence polarization (FP) assay, we screened a library of compounds that could act as small molecule modulators of HSP20 signals. We then applied two quantitative, cell-based biophysical methods to assess the functional efficacy of these molecules and rank-ordered their abilities to relax isolated human airway smooth muscle (ASM). Scaling up to the level of an intact tissue, we confirmed in a concentration-responsive manner the potency of the cell-based hit compounds. Results Among 58,019 compound tested, 268 compounds caused 20% or more reduction of the polarized emission in the FP assay. A small subset of these primary screen hits, belonging to two scaffolds, caused relaxation of isolated ASM cell in vitro and attenuated active force development of intact tissue ex vivo. Conclusions This staged biophysical screening paradigm provides proof-of-principle for high-throughput and cost-effective discovery of new small molecule therapeutic agents for obstructive lung diseases.
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Affiliation(s)
- Steven S An
- Division of Physiology, Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA.
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Uhiara CO, Alexander SPH, Roberts RE. Effect of inhibition of extracellular signal-regulated kinase on relaxations to beta-adrenoceptor agonists in porcine isolated blood vessels. Br J Pharmacol 2010; 158:1713-9. [PMID: 19912229 DOI: 10.1111/j.1476-5381.2009.00435.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND AND PURPOSE Stimulation of vascular beta-adrenoceptors causes vasodilatation through activation of adenylyl cyclase (AC) and plasma membrane potassium channels, and beta-adrenoceptors have been linked to activation of extracellular signal-regulated kinase (ERK) mitogen-activated protein kinase in various cell lines. However, how these findings relate to functional responses in intact tissues is largely unknown. The aim of this study, therefore, was to investigate the role of ERK in beta-adrenoceptor-induced vasodilatation. EXPERIMENTAL APPROACH Segments of porcine coronary artery were mounted in a Mulvany wire myograph and bathed in Krebs-Henseleit buffer gassed with 95% O(2)/5% CO(2) and maintained at 37 degrees C. Tissues were pre-contracted with the thromboxane mimetic U46619, endothelin-1 or KCl. Cumulative concentration-response curves to beta-adrenoceptor agonists or forskolin were then carried out in the absence or presence of the mitogen-activated protein kinase kinase (MEK) inhibitors PD98059 (10 or 50 microM) or U0126 (10 microM). KEY RESULTS PD98059 caused a concentration-dependent leftward shift in response to isoprenaline (pEC(50) control, 7.5 +/- 0.1; 50 microM PD98059, 8.1 +/- 0.1: P < 0.05). Inhibition of MEK also enhanced the maximum relaxation seen with salbutamol, but not the responses to the beta(1)-adrenoceptor selective agonist xamoterol or the AC activator forskolin. There was no enhancement of the relaxations to beta-adrenoceptor agonists after inhibition of ERK activation in tissues pre-contracted with KCl or treated with the K(+) channel blocker tetraethylammonium. CONCLUSIONS AND IMPLICATIONS These data indicate that ERK inhibits beta(2)-adrenoceptor-mediated vasodilatation through a mechanism which may involve inactivation of plasma membrane potassium channels.
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Affiliation(s)
- C O Uhiara
- School of Biomedical Sciences, University of Nottingham, Medical School, Nottingham, UK
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Dreiza CM, Komalavilas P, Furnish EJ, Flynn CR, Sheller MR, Smoke CC, Lopes LB, Brophy CM. The small heat shock protein, HSPB6, in muscle function and disease. Cell Stress Chaperones 2010; 15:1-11. [PMID: 19568960 PMCID: PMC2866971 DOI: 10.1007/s12192-009-0127-8] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2009] [Accepted: 06/05/2009] [Indexed: 10/20/2022] Open
Abstract
The small heat shock protein, HSPB6, is a 17-kDa protein that belongs to the small heat shock protein family. HSPB6 was identified in the mid-1990s when it was recognized as a by-product of the purification of HSPB1 and HSPB5. HSPB6 is highly and constitutively expressed in smooth, cardiac, and skeletal muscle and plays a role in muscle function. This review will focus on the physiologic and biochemical properties of HSPB6 in smooth, cardiac, and skeletal muscle; the putative mechanisms of action; and therapeutic implications.
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St Hilaire RC, Kadowitz PJ, Jeter JR. Adenoviral transfer of vasoactive intestinal peptide (VIP) gene inhibits rat aortic and pulmonary artery smooth muscle cell proliferation. Peptides 2009; 30:2323-9. [PMID: 19698755 PMCID: PMC2787868 DOI: 10.1016/j.peptides.2009.08.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2009] [Revised: 08/11/2009] [Accepted: 08/11/2009] [Indexed: 10/20/2022]
Abstract
Vasoactive intestinal peptide (VIP), a 28 amino acid peptide, has been shown to inhibit proliferation of vascular smooth muscle cells. In previous studies VIP and VIP analogs have been used to study the effects of the peptide on vascular smooth muscle cell function. In this study an adenovirus encoding the VIP gene was used to investigate the mechanism of the antiproliferative action of VIP in vascular smooth muscle cells. Primary cultures of aortic and pulmonary artery smooth muscle cells from male Sprague-Dawley rats were transfected with varying concentrations of serotype 5 adenovirus encoding human VIP (Ad5CMVhVIP). Transfection efficiency and subsequently VIP gene expression were confirmed by western blot analysis and immunohistochemistry. In this study a decrease in vascular smooth muscle cell proliferation at vector concentrations of 150, 300 and 600MOI (multiplicity of infection) was observed. In addition, there was increased production of cAMP in pulmonary artery and aortic smooth muscle cells transfected with VIP. Treatment of cells with a PKA inhibitor (Rp-8-BrcAMPs) restored proliferation to about 80% of control whereas treatment with the PKG inhibitor Rp-8-BrcGMPs had no significant effect suggesting the involvement of the PKA pathway in the antiproliferative actions of VIP.
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Affiliation(s)
- Rose-Claire St Hilaire
- Department of Pharmacology, Tulane University School of Medicine, 1430 Tulane Ave, New Orleans, LA 70112, USA
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Han KH, Cheon GJ, Yeon DS, Kwon SC. Forskolin Changes the Relationship between Cytosolic Ca and Contraction in Guinea Pig Ileum. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2009; 13:189-194. [PMID: 19885036 PMCID: PMC2766733 DOI: 10.4196/kjpp.2009.13.3.189] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2009] [Revised: 05/15/2009] [Accepted: 06/02/2009] [Indexed: 05/28/2023]
Abstract
This study was designed to clarify the mechanism of the inhibitory effect of forskolin on contraction, cytosolic Ca(2+) level ([Ca(2+)](i)), and Ca(2+) sensitivity in guinea pig ileum. Forskolin (0.1 nM~10 microM) inhibited high K(+) (25 mM and 40 mM)- or histamine (3 microM)-evoked contractions in a concentration-dependent manner. Histamine-evoked contractions were more sensitive to forskolin than high K(+)-evoked contractions. Spontaneous changes in [Ca(2+)](i) and contractions were inhibited by forskolin (1 microM) without changing the resting [Ca(2+)](i). Forskoln (10 microM) inhibited muscle tension more strongly than [Ca(2+)](i) stimulated by high K(+), and thus shifted the [Ca(2+)](i)-tension relationship to the lower-right. In histamine-stimulated contractions, forskolin (1 microM) inhibited both [Ca(2+)](i) and muscle tension without changing the [Ca(2+)](i)-tension relationship. In alpha-toxin-permeabilized tissues, forskolin (10 microM) inhibited the 0.3 microM Ca(2+)-evoked contractions in the presence of 0.1 mM GTP, but showed no effect on the Ca(2+)-tension relationship. We conclude that forskolin inhibits smooth muscle contractions by the following two mechanisms: a decrease in Ca(2+) sensitivity of contractile elements in high K(+)-stimulated muscle and a decrease in [Ca(2+)](i) in histamine-stimulated muscle.
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Affiliation(s)
- Koon Hee Han
- Department of Internal Medicine, Gangnung Asan Hospital, Gangnung 210-711, Korea
- Department of Physiology, College of Medicine, Kwandong University, Gangneung 210-751, Korea
| | - Gap Jin Cheon
- Department of Internal Medicine, Gangnung Asan Hospital, Gangnung 210-711, Korea
- Department of Physiology, College of Medicine, Kwandong University, Gangneung 210-751, Korea
| | - Dong Soo Yeon
- Department of Physiology, College of Medicine, Kwandong University, Gangneung 210-751, Korea
| | - Seong Chun Kwon
- Department of Physiology, College of Medicine, Kwandong University, Gangneung 210-751, Korea
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El-Gowilly SM, Ghazal ARM, Gohar EY, El-Mas MM. Exacerbation by nicotine of the cyclosporine A-induced impairment of beta-adrenoceptor-mediated renal vasodilation in rats. Clin Exp Pharmacol Physiol 2008; 35:1164-71. [PMID: 18565199 DOI: 10.1111/j.1440-1681.2008.04983.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Nicotine is implicated in smoking-related renovascular impairment and worsening of existing nephropathies. In the present study, we investigated whether nicotine aggravates the deleterious effect of the immunosuppressant drug cyclosporine A (CsA) on renal vasodilation induced by the beta-adrenoceptor agonist isoprenaline. Bolus isoprenaline (0.03-8.0 micromol) elicited dose-dependent vasodilation of phenylephrine-preconstricted perfused kidneys that was attenuated by infusion at 5 mL/min of nicotine (5 x 10(-4) mol/L) or CsA (2 micromol/L). Further, chronic administration of nicotine (0.4 mg/kg per day) or CsA (20 mg/kg per day) for 3 weeks reduced isoprenaline-induced vasodilation and elevated plasma urea and creatinine concentrations, effects that were magnified when both nicotine and CsA were administered concurrently. The role of endothelial and smooth muscle signalling in the acute nicotine/CsA renovascular interaction was investigated. Vasodilation caused by 0.25 micromol isoprenaline was attenuated by 6 micromol/L propranolol and 10 mmol/L tetraethylammonium (TEA), potentiated by 100 micromol/L hexamethonium and 7 micromol/L diclophenac, and virtually abolished in 80 mmol/L KCl-preconstricted tissues. N(G)-Nitro-L-arginine (L-NNA; 200 micromol/L), methylene blue (10 micromol/L), 3-[(3-cholamidopropyl)-dimethyl-ammonio]-1-propane-sulphonate (CHAPS; 0.2% for 30 s), nifedipine (750 nmol/L), atropine (1 micromol/L) and SQ22536 (an adenylyl cyclase inhibitor; 3 x 10(-5) mol/L) had no effect on isoprenaline responses. Nicotine (5 x 10(-4) mol/L) reduced isoprenaline-induced vasodilation and this effect was potentiated by concurrent CsA (2 micromol/L) infusion. Nicotine-induced impairment of the vasodilator response to isoprenaline was reduced by hexamethonium and potentiated by L-NNA, methylene blue, CHAPS and nifedipine. Alternatively, CsA exacerbation of the nicotine-isoprenaline interaction was abolished by propranolol, L-NNA, methylene blue, CHAPS, L-arginine, TEA and nifedipine. 5. In summary, nicotine and CsA produce additive impairment of kidney function and beta-adrenoceptor-mediated renovascular control, nitric oxide (NO)-cGMP signalling tonically restrains nicotine-induced impairment of isoprenaline vasodilation and the endothelial NO-K+ pathway modulates the aggravating effect of CsA on nicotine-isoprenaline interactions.
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Affiliation(s)
- Sahar M El-Gowilly
- Department of Pharmacology, Faculty of Pharmacy, University of Alexandria, Alexandria, Egypt
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Abstract
Phosphodiesterase type 5A (PDE5A) selectively hydrolyzes cyclic GMP. Inhibitors of PDE5A such as sildenafil are widely used to treat erectile dysfunction, but growing evidence supports important roles for the enzyme in both the vasculature and heart. In disorders such as cardiac failure, PDE5A upregulation may contribute to a decline in cGMP and protein kinase G signaling, exacerbating dysfunction. PDE5A plays an important role in the pulmonary vasculature where its inhibition benefits patients with pulmonary hypertension. In the heart, PDE5A signaling appears compartmentalized, and its inhibition is cardioprotective against ischemia-reperfusion and antracycline toxicity, blunts acute adrenergic contractile stimulation, and can suppress chronic hypertrophy and dysfunction attributable to pressure-overload. In this review, we discuss the molecular biology, pharmacology, and physiology of PDE5A, mechanisms of vascular and cardiac regulation, and recent evidence supporting the utility of selective PDE5A inhibition for the treatment of cardiovascular disorders.
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Affiliation(s)
- David A Kass
- Division of Cardiology, Department of Medicine, Johns Hopkins Medical Institutions, Baltimore, MD 21205, USA.
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Kim M, Hennig GW, Smith TK, Perrino BA. Phospholamban knockout increases CaM kinase II activity and intracellular Ca2+ wave activity and alters contractile responses of murine gastric antrum. Am J Physiol Cell Physiol 2007; 294:C432-41. [PMID: 18045856 DOI: 10.1152/ajpcell.00418.2007] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Phospholamban (PLB) inhibits the sarcoplasmic reticulum (SR) Ca(2+)-ATPase (SERCA), and this inhibition is relieved by Ca(2+) calmodulin-dependent protein kinase II (CaM kinase II) phosphorylation. We previously reported significant differences in contractility, SR Ca(2+) release, and CaM kinase II activity in gastric fundus smooth muscles as a result of PLB phosphorylation by CaM kinase II. In this study, we used PLB-knockout (PLB-KO) mice to directly examine the effect of PLB absence on contractility, CaM kinase II activity, and intracellular Ca(2+) waves in gastric antrum smooth muscles. The frequencies and amplitudes of spontaneous phasic contractions were elevated in antrum smooth muscle strips from PLB-KO mice. Bethanecol increased the amplitudes of phasic contractions in antrum smooth muscles from both control and PLB-KO mice. Caffeine decreased and cyclopiazonic acid (CPA) increased the basal tone of antrum smooth muscle strips from PLB-KO mice, but the effects were less pronounced compared with control strips. The CaM kinase II inhibitor KN-93 was less effective at inhibiting caffeine-induced relaxation in antrum smooth muscle strips from PLB-KO mice. CaM kinase II autonomous activity was elevated, and not further increased by caffeine, in antrum smooth muscles from PLB-KO mice. Similarly, the intracellular Ca(2+) wave frequency was elevated, and not further increased by caffeine, in antrum smooth muscles from PLB-KO mice. These findings suggest that PLB is an important modulator of gastric antrum smooth muscle contractility by modulation of SR Ca(2+) release and CaM kinase II activity.
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Affiliation(s)
- Minkyung Kim
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, NV 89557, USA
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37
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Smani T, Domínguez-Rodríguez A, Hmadcha A, Calderón-Sánchez E, Horrillo-Ledesma A, Ordóñez A. Role of Ca2+-independent phospholipase A2 and store-operated pathway in urocortin-induced vasodilatation of rat coronary artery. Circ Res 2007; 101:1194-203. [PMID: 17885217 DOI: 10.1161/circresaha.107.159053] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Urocortin has been shown to produce vasodilatation in several arteries, but the precise mechanism of its action is still poorly understood. Here we demonstrate the role of store operated Ca2+ entry (SOCE) regulated by Ca2+-independent phospholipase A2 (iPLA2) in phenylephrine hydrochloride (PE)-induced vasoconstriction, and we present the first evidence that urocortin induces relaxation by the modulation of SOCE and iPLA2 in rat coronary artery. Urocortin produces an endothelium independent relaxation, and its effect is concentration-dependent (IC50 approximately = 4.5 nmol/L). We show in coronary smooth muscle cells (SMCs) that urocortin inhibits iPLA2 activation, a crucial step for SOC channel activation, and prevents Ca2+ influx evoked by the emptying of the stores via a cAMP and protein kinase A (PKA)-dependent mechanism. Lysophophatidylcholine and lysophosphatidylinositol, products of iPLA2, exactly mimic the effect of the depletion of the stores in presence of urocortin. Furthermore, we report that long treatment with urocortin downregulates iPLA2 mRNA and proteins expression in rat coronary smooth muscle cells. In summary, we propose a new mechanism of vasodilatation by urocortin which involves the regulation of iPLA2 and SOCE via the stimulation of a cAMP/PKA-dependent signal transduction cascade in rat coronary artery.
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Affiliation(s)
- Tarik Smani
- Laboratorio de Investigación Cardiovascular, Quirófanos Experimentales, Hospital General Universitario Virgen del Rocío, Avenida Manuel Siurot s/n, E-41013 Sevilla, Spain.
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38
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Li Y, Sherer K, Cui X, Eichacker PQ. New insights into the pathogenesis and treatment of anthrax toxin-induced shock. Expert Opin Biol Ther 2007; 7:843-54. [PMID: 17555370 DOI: 10.1517/14712598.7.6.843] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Inhalational Bacillus anthracis infection is a leading bioterrorist health threat in the US today. Lethal (LeTx) and edema toxin production are key to the virulent effects of this lethal bacteria. Recent insights into the structure and function of these toxins have increased the understanding of both the pathogenesis and treatment of anthrax. These are binary type toxins comprised of protective antigen necessary for their cellular uptake and either lethal or edema factors, the toxigenic moieties. Primary cellular receptors for protective antigen have been identified and the processing of the completed toxins clarified. Consistent with the ability of lethal factor to cleave mitogen activated protein kinase kinases, the evidence indicates that an excessive inflammatory response does not contribute to shock with LeTx. Rather, the immunosuppressive effects of LeTx could promote infection; however, direct endothelial dysfunction may have an important role in shock due to LeTx. Recent studies show that edema factor, a potent adenyl cyclase, may have a major role in shock during anthrax and that it may also be immunosuppresive. Therapies under development which target several steps in the cellular uptake and function of these two toxins have been effective in both in vitro and in vivo systems. Understanding how best to apply these agents in combination with conventional treatments should be a goal of future research.
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MESH Headings
- Adenylyl Cyclases/immunology
- Adenylyl Cyclases/metabolism
- Animals
- Anthrax/complications
- Anthrax/drug therapy
- Anthrax/metabolism
- Anthrax Vaccines/therapeutic use
- Antibodies, Monoclonal/therapeutic use
- Antigens, Bacterial/immunology
- Antigens, Bacterial/metabolism
- Bacillus anthracis/immunology
- Bacillus anthracis/metabolism
- Bacillus anthracis/pathogenicity
- Bacterial Toxins/immunology
- Bacterial Toxins/metabolism
- Endothelium, Vascular/microbiology
- Endothelium, Vascular/physiopathology
- Humans
- Receptors, Peptide/metabolism
- Shock, Septic/drug therapy
- Shock, Septic/metabolism
- Shock, Septic/microbiology
- Shock, Septic/physiopathology
- Virulence
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Affiliation(s)
- Yan Li
- National Institutes of Health, Critical Care Medicine Department, Clinical Center, Bethesda, MD 20892, USA
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Biswal BB, Kannurpatti SS, Rypma B. Hemodynamic scaling of fMRI-BOLD signal: validation of low-frequency spectral amplitude as a scalability factor. Magn Reson Imaging 2007; 25:1358-69. [PMID: 17482411 PMCID: PMC2701471 DOI: 10.1016/j.mri.2007.03.022] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2006] [Revised: 02/16/2007] [Accepted: 03/13/2007] [Indexed: 10/23/2022]
Abstract
Functional magnetic resonance imaging blood-oxygenation-level-dependent (fMRI-BOLD) signal representing neural activity may be optimized by discriminating MR signal components related to neural activity and those related to intrinsic properties of the cortical vasculature. The objective of this study was to reduce the hemodynamic change independent of neural activity to obtain a scaled fMRI-BOLD response using two factors, namely, low-frequency spectral amplitude (LFSA) and breath-hold amplitude (BHA). Ten subjects (age range, 22-38 years) were scanned during four task conditions: (a) rest while breathing room air, (b) bilateral finger tapping while breathing room air, (c) rest during a partial inspirational breath-hold, and (d) rest during moderate hypercapnia (breathing 5% CO2, 20% O2 and 75% N2). In all subjects who breathed 5% CO2, regions with significant BOLD response during breath-hold correlated significantly with the percent signal increase during 5% CO2 inhalation. Finger-tapping-induced responses in the motor cortex were diminished to a similar extent after scaling using either LFSA or BHA. Inter- and intrasubject variation in the amplitude of the BOLD signal response reduced after hemodynamic scaling using LFSA or BHA. The results validated the hemodynamic amplitude scaling using LFSA with the earlier established BHA. LFSA free from motor-task contamination can be used to calibrate the fMRI-BOLD response in lieu of BHA or hypercapnia to minimize intra- and intersubject variation arising from vascular anatomy and vasodilative capacity.
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Affiliation(s)
- Bharat B Biswal
- Department of Radiology, UMDNJ-New Jersey Medical School, Newark, NJ 07103, USA.
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40
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Zhao H, Quilley J, Montrose DC, Rajagopalan S, Guan Q, Smith CJ. Differential effects of phosphodiesterase PDE-3/PDE-4-specific inhibitors on vasoconstriction and cAMP-dependent vasorelaxation following balloon angioplasty. Am J Physiol Heart Circ Physiol 2007; 292:H2973-81. [PMID: 17293498 DOI: 10.1152/ajpheart.00419.2006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
It is known that cAMP and cGMP are important for vasorelaxation, and cyclic nucleotide phosphodiesterases (PDEs) regulate their levels. Balloon angioplasty (BAL) is associated with reduced cAMP and cGMP levels, and inhibition of PDE-3 reduces restenosis. In this study, we found that BAL increased PDE-3 activity, which affected vasoreactivity of rat aortic rings 24-h post-BAL; these were compared with intact (INT) and ex vivo endothelium-denuded rings (RUB) from sham rats. In BAL and RUB rings, vasorelaxant responses to ACh were abolished. The EC(50) for phenylephrine (PE) was 1.8-fold less in RUB than in INT or BAL, whereas the maximal contractile effect of PE was greater in BAL than in INT or RUB. PDE-3 inhibitors reduced the maximal response to PE by >65% in BAL compared with 10-30% in INT and RUB; the reduction of the maximal response to U-46619 was 37% in BAL compared with 8% in INT with no reduction in RUB. PDE-4 inhibitors reduced PE-induced tone by <30% in an endothelium-dependent manner. Vasorelaxant responses to agonists that utilize cAMP were greatly impaired in BAL and RUB rings, and inhibition of PDE-3 enhanced the vasorelaxant responses in BAL or RUB. Inhibition of PDE-4 increased vasorelaxant responses to isoproterenol (ISO) to a much lesser degree. Thus PDE-3 and PDE-4 inhibitors exhibited differential effects on PE-induced tone and vasorelaxant responses to ISO. Inhibition of PDE-3 also produced a greater increase in cAMP in BAL than INT or RUB rings. These results suggest that increased PDE-3 activity after BAL may promote a vasospastic state and that the reduction in cAMP may, possibly, influence vessel remodeling.
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MESH Headings
- 3',5'-Cyclic-AMP Phosphodiesterases/antagonists & inhibitors
- 3',5'-Cyclic-AMP Phosphodiesterases/metabolism
- Angioplasty, Balloon/adverse effects
- Animals
- Aorta/drug effects
- Aorta/enzymology
- Aorta/injuries
- Aorta/physiopathology
- Carboxylic Acids/pharmacology
- Cilostazol
- Cyclic AMP/metabolism
- Cyclic AMP-Dependent Protein Kinases/metabolism
- Cyclic Nucleotide Phosphodiesterases, Type 3
- Cyclic Nucleotide Phosphodiesterases, Type 4
- Cyclohexanecarboxylic Acids
- Disease Models, Animal
- Dose-Response Relationship, Drug
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/enzymology
- Endothelium, Vascular/physiopathology
- In Vitro Techniques
- Male
- Milrinone/pharmacology
- Nitriles/pharmacology
- Phosphodiesterase Inhibitors/pharmacology
- Phosphorylation
- Quinolones/pharmacology
- Rats
- Rats, Sprague-Dawley
- Tetrazoles/pharmacology
- Up-Regulation
- Vasoconstriction/drug effects
- Vasoconstrictor Agents/pharmacology
- Vasodilation/drug effects
- Vasodilator Agents/pharmacology
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Affiliation(s)
- Hong Zhao
- Department of Pharmacology, New York Medical College, Valhalla, NY 10595, USA.
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41
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Abstract
The beta-adrenoceptor (AR) is currently classified into beta(1), beta(2), and beta(3) subtypes. A third subtype, beta(3)-AR, was first identified in adipose tissue, but has also been identified in smooth muscle tissue, particularly in the gastrointestinal tract and urinary bladder smooth muscle. There is a predominant expression of beta(3)-AR messenger RNA (mRNA) in human bladder, with 97% of total beta-AR mRNA being represented by the beta(3)-AR subtype and only 1.5 and 1.4% by the beta(1)-AR and beta (2)-AR subtypes, respectively. Moreover, the presence of beta(1)-, beta(2)-, and beta(3)-AR mRNAs in the urothelium of human bladder has been identified. The distribution of beta-AR subtypes mediating detrusor muscle relaxation is species dependent, the predominant subtype being the beta(3)-AR in humans. Recent studies have suggested that cAMP-dependent routes are not exclusive mechanisms triggering the beta-AR-mediated relaxation of smooth muscle. It has been demonstrated in rats detrusor muscle that cAMP plays a greater role in beta-adrenergic relaxation against basal tone than against KCl-induced tone and that conversely calcium-activated K(+) channels (BKca channels) play a greater role under the latter circumstances. In rat models, beta(3)-AR agonists increase bladder capacity without influencing bladder contraction and have only weak cardiovascular side effects. Although this evidence points toward the clinical utility of beta(3)-AR agonists as therapy for overactive bladder (OAB), pharmacological differences exist between rat and human beta(3)-ARs. Development of compounds with high selectivity for the human beta(3)-AR, identified by screening techniques using cell lines transfected with the human beta(1)-, beta(2)-, and beta(3)-AR genes, may mitigate against such problems. The association between the tryptophan 64 arginine polymorphism in the beta(3)-AR gene and idiopathic OAB is discussed.
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Sherer K, Li Y, Cui X, Eichacker PQ. Lethal and edema toxins in the pathogenesis of Bacillus anthracis septic shock: implications for therapy. Am J Respir Crit Care Med 2006; 175:211-21. [PMID: 17095744 PMCID: PMC2176088 DOI: 10.1164/rccm.200608-1239cp] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Recent research regarding the structure and function of Bacillus anthracis lethal (LeTx) and edema (ETx) toxins provides growing insights into the pathophysiology and treatment of shock with this lethal bacteria. These are both binary-type toxins composed of protective antigen necessary for their cellular uptake and either lethal or edema factors, the toxigenic moieties. The primary cellular receptors for protective antigen have been identified and constructed and key steps in the extracellular processing and internalization of the toxins clarified. Consistent with the lethal factor's primary action as an intracellular endopeptidase targeting mitogen-activated protein kinase kinases, growing evidence indicates that shock with this toxin does not result from an excessive inflammatory response. In fact, the potent immunosuppressive effects of LeTx may actually contribute to the establishment and persistence of infection. Instead, shock with LeTx may be related to the direct injurious effects of lethal factor on endothelial cell function. Despite the importance of LeTx, very recent studies show that edema factor, a potent adenyl cyclase, has the ability to make a substantial contribution to shock caused by B. anthracis and works additively with LeTx. Furthermore, ETx may contribute to the immunosuppressive effects of LeTx. Therapies under development that target several different steps in the cellular uptake and function of these two toxins have been effective in in vitro and in vivo systems. Understanding how best to apply these agents clinically and how they interact with conventional treatments should be goals for future research.
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Affiliation(s)
- Kevin Sherer
- Critical Care Medicine Department, National Institutes of Health, Bethesda, MD 20892, USA
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43
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El-Mas MM, Sharabi FM, El-Gowilly SM, El-Din MMM. Inhibition of nitric oxide-guanylate cyclase-dependent and -independent signaling contributes to impairment of beta-adrenergic vasorelaxations by cyclosporine. Biochem Pharmacol 2006; 73:359-67. [PMID: 17113040 DOI: 10.1016/j.bcp.2006.10.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2006] [Revised: 10/14/2006] [Accepted: 10/17/2006] [Indexed: 12/11/2022]
Abstract
This study investigated the role of endothelium- and smooth muscle-dependent mechanisms in the interaction of cyclosporine (CyA), an immunosuppressant drug, with beta-adrenoceptor (isoprenaline)-mediated relaxations in isolated rat aortas precontracted with phenylephrine. CyA effects were assessed in the absence and presence of NG-nitro-L-arginine methyl ester (L-NAME, nitric oxide synthase inhibitor), methylene blue (guanylate cyclase inhibitor), or propranolol (beta-adrenoceptor antagonist). In aortas with intact endothelium (E+), pretreatment with L-NAME or methylene blue significantly reduced isoprenaline (1 x 10(-9) to 1 x 10(-7)M) relaxations in contrast to no effect for tetraethylammonium (K+ channel blocker), or diclophenac (cyclooxygenase inhibitor), suggesting a major role for the nitric oxide-guanylate cyclase (NO-GC) pathway, but not endothelial hyperpolarizing factor or vasodilator prostanoids, in isoprenaline responses. Isoprenaline relaxations were still evident, though significantly attenuated, in endothelium-denuded aortas (E-) and were resistant to L-NAME or methylene blue. Acute exposure to CyA (2 microM) caused propranolol-sensitive reductions in isoprenaline responses in E+ and E- aortas. The CyA-induced attenuation of isoprenaline responses in E+ aortas largely disappeared in L-NAME-treated aortas and after supplementation with L-arginine, the substrate of nitric oxide. CyA also reduced the endothelium-independent, GC-dependent aortic relaxations evoked by sodium nitroprusside, an effect that was virtually abolished by methylene blue. We conclude that: (i) endothelial and smooth muscle mechanisms contribute to aortic beta-adrenoceptor relaxations and both components are negatively influenced by CyA, and (ii) NO-GC signaling plays an integral role in the vascular CyA-beta-adrenoceptor interaction. The clinical relevance of the present study is warranted given the established role of impaired vascular function in CyA toxicity.
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Affiliation(s)
- Mahmoud M El-Mas
- Department of Pharmacology, Faculty of Pharmacy, University of Alexandria, Alexandria, Egypt.
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44
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Flynn CR, Smoke CC, Furnish E, Komalavilas P, Thresher J, Yi Z, Mandarino LJ, Brophy CM. Phosphorylation and activation of a transducible recombinant form of human HSP20 in Escherichia coli. Protein Expr Purif 2006; 52:50-8. [PMID: 17084643 PMCID: PMC1839877 DOI: 10.1016/j.pep.2006.08.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2006] [Accepted: 08/19/2006] [Indexed: 10/24/2022]
Abstract
Protein-based cellular therapeutics have been limited by getting molecules into cells and the fact that many proteins require post-translational modifications for activation. Protein transduction domains (PTDs), including that from the HIV TAT protein (TAT), are small arginine rich peptides that carry molecules across the cell membrane. We have shown that the heat shock-related protein, HSP20 is a downstream-mediator of cyclic nucleotide-dependent relaxation of vascular smooth muscle and is activated by phosphorylation. In this study, we co-expressed in Escherichia coli the cDNAs encoding the catalytic subunit of protein kinase G and a TAT-HSP20 fusion protein composed of the TAT PTD (-YGRKKRRQRRR-) fused to the N-terminus of human HSP20. Immunoblot and HPLC-ESI-MS/MS analysis of the purified TAT-HSP20 demonstrated that it was phosphorylated at serine 40 (equivalent to serine 16 in wild-type human HSP20). This phosphorylated TAT-HSP20 was physiologically active in intact smooth muscles in that it inhibited 5-hydroxytryptamine-induced contractions by 57%+/-4.5. The recombinant phosphorylated protein also led to changes in actin cytoskeletal morphology in 3T3 cells. These results delineate strategies for the expression and activation of therapeutic molecules for intracellular protein based therapeutics.
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Affiliation(s)
- Charles R Flynn
- Arizona State University, Harrington Department of Bioengineering, Tempe, AZ 85287-9709, USA.
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45
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Besirli K, Burhani SM, Arslan C, Suzer O, Sayin AG. Effect of Combining Phosphodiesterase III Inhibitors With St Thomas Hospital’s Solution Used as Transplantation Preservative Solution in Isolated Rat Hearts. Transplant Proc 2006; 38:1253-8. [PMID: 16797275 DOI: 10.1016/j.transproceed.2006.02.062] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2005] [Indexed: 11/27/2022]
Abstract
Improved preservation of the harvested heart with attenuation of the reperfusion injury is important for successful outcomes of cardiac transplantations. The most commonly used cardioplegic solution, to prevent ischemic changes has been St Thomas' Hospital cardioplegic solution (STHCS). However, it is neither ideal nor sufficient to prevent myocardial ischemia and reperfusion injury. Phosphodiesterase inhibitors can attenuate the damage due to the injuries of ischemia and reperfusion. In this study we sought to enrich STHCS with a phosphodiesterase inhibitor to improve preservation of cardiac functions. The harvested hearts of 24 rats were divided into four groups. All hearts were mounted on a Langendorff perfusion system. After a stabilization period, cardiac arrest was maintained by STHCS. The hearts were stored in STHCS alone or with milrinone, amrinone, or enoximone for 6 hours. The reperfusion was maintained using a modified Tyrode's solution. All hearts were compared for their preischemic and postischemic left ventricular developed pressure, +dp/dtmax, -dp/dtmax, duration of systole, ejection time, and time to reach peak systolic pressure. Coronary effluent was collected for lactate dehydrogenase (LDH) measurements. The initial values for all metrics were comparable between the groups. During the postreperfusion period, all hearts showed lower peak systolic pressures than the initial values. Although the amrinone group seemed to have higher values, the 25-minute result was at the border of significance and the 30-minute value, significantly higher. All hearts showed far lower results of maximum changes in contractility during the time period (+dp/dtmax) versus the initial values; comparisons between groups were not significant. For the parameter of maximum changes in relaxation during the time period (-dp/dtmax), while other hearts showed lower results, the amrinone group displayed values comparable to the initial ones after 20 minutes. Comparisons between groups were insignificant. While other hearts had comparable values for time of systole, the hearts applied with milrinone reached these values after 15 minutes. Group comparison for time of ejection revealed that the results at 5-minute postreperfusion were higher in the enoximone and the amrinone groups than the milrinone group. Postreperfusion 5-minute results were higher in the enoximone and the amrinone groups than the milrinone group for time to reach peak systolic pressure. LDH levels were lowest in the amrinone group. In conclusion, our study revealed that adding phosphodiesterase inhibitors to STHCS improved peak systolic pressure and maximum changes in relaxation during the time period (-dp/dtmax, mm Hg/s). It also decreased the LDH leakage, which corresponded to the degree of ischemic tissue damage. Amrinone seemed to result in more favorable results, which may be attributed to its additional effects on inflammation, including those on cytokines and leukocyte aggregation.
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Affiliation(s)
- K Besirli
- Department of Cardiovascular Surgery, Cerrahpasa Medical Faculty, Istanbul University, Istanbul, Turkey.
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46
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Matsumoto T, Kobayashi T, Kamata K. Mechanisms underlying the impaired EDHF-type relaxation response in mesenteric arteries from Otsuka Long-Evans Tokushima Fatty (OLETF) rats. Eur J Pharmacol 2006; 538:132-40. [PMID: 16678154 DOI: 10.1016/j.ejphar.2006.04.006] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2005] [Revised: 03/02/2006] [Accepted: 04/03/2006] [Indexed: 12/30/2022]
Abstract
We previously reported that in mesenteric arteries from streptozotocin-induced diabetic rats, the endothelium-derived hyperpolarizing factor (EDHF)-type relaxation is impaired, possibly due to a reduced action of cAMP. Here, we observed an impairment of acetylcholine-induced EDHF-type relaxation in mesenteric arteries from a type 2 diabetic model, Otsuka Long-Evans Tokushima Fatty (OLETF) rats [vs. age-matched control Long-Evans Tokushima Otsuka (LETO) rats], and we investigated the mechanism underlying this impairment. In the LETO group, this EDHF-type relaxation was attenuated by 18alpha-glycyrrhetinic acid (a gap-junction inhibitor) and by a protein kinase A (PKA) inhibitor. In both groups (OLETF and LETO), it was enhanced by 3-isobutyl-1-methylxanthine, a cAMP-phosphodiesterase (PDE) inhibitor, but following these enhancements it was still weaker in OLETF rats than in LETO rats. The relaxations induced by cilostamide (a selective PDE3 inhibitor) and 8-bromo-cAMP (a cell-permeant cAMP analog) were reduced in OLETF rats, as was PKA activity. The relaxations induced by two activators of Ca(2+)-activated K(+) channels (K(Ca)) [1-ethyl-2-benzimidazolinone (1-EBIO), intermediate-conductance K(Ca) channel (IK(Ca)) activator, and riluzole, small-conductance K(Ca) channel (SK(Ca)) activator] were also impaired in OLETF rats. We conclude that the impairment of EDHF-type relaxation seen in OLETF rats may be attributable not only to a reduction in cAMP/PKA signaling, but also to reduced endothelial K(Ca) channel activities.
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Affiliation(s)
- Takayuki Matsumoto
- Department of Physiology and Morphology, Institute of Medicinal Chemistry, Hoshi University, Shinagawa-ku, Tokyo 142-8501, Japan
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47
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Son YK, Park WS, Ko JH, Han J, Kim N, Earm YE. Protein kinase A-dependent activation of inward rectifier potassium channels by adenosine in rabbit coronary smooth muscle cells. Biochem Biophys Res Commun 2005; 337:1145-52. [PMID: 16226714 DOI: 10.1016/j.bbrc.2005.09.176] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2005] [Accepted: 09/29/2005] [Indexed: 10/25/2022]
Abstract
We studied the effect of adenosine on the Ba(2+)-sensitive K(IR) channels in the smooth muscle cells isolated from the small-diameter (<100microm) coronary arteries of rabbit. Adenosine increased K(IR) currents in concentration-dependent manner (EC(50)=9.4+/-1.4microM, maximum increase of 153%). The adenosine-induced stimulation of K(IR) current was blocked by adenylyl cyclase inhibitor, SQ22536 and was mimicked by adenylyl cyclase activator, forskolin. The adenosine-induced increase of current was blocked by cyclic AMP-dependent protein kinase (PKA) inhibitors, KT 5720 and Rp-8-CPT-cAMPs. The adenosine-induced increase of K(IR) currents was blocked by an A(3)-selective antagonist MRS1334, while the antagonists of other subtypes (DPCPX for A(1), ZM241385 for A(2A), and alloxazine for A(2B)) were all ineffective. Furthermore, an A(3)-selective agonist, 2-Cl-IB-MECA induced increase of K(IR) currents. We also examined the effect of adenosine on coronary blood flow (CBF) rate by using the Langendorff-perfused heart. In the presence of glibenclamide to exclude the effects of ATP-sensitive K(+) (K(ATP)) channels, CBF was increased by adenosine (10microM), which was blocked by the addition of Ba(2+) (50microM). Above results suggest that adenosine increases K(IR) current via A(3) subtype through the activation of PKA in rabbit small-diameter coronary arterial smooth muscle cells.
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Affiliation(s)
- Youn Kyoung Son
- Department of Physiology and National Research Laboratory for Cellular Signaling, Seoul National University College of Medicine, Seoul, Republic of Korea
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48
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Uchida H, Shishido K, Nomiya M, Yamaguchi O. Involvement of cyclic AMP-dependent and -independent mechanisms in the relaxation of rat detrusor muscle via beta-adrenoceptors. Eur J Pharmacol 2005; 518:195-202. [PMID: 16054622 DOI: 10.1016/j.ejphar.2005.06.029] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2005] [Revised: 06/14/2005] [Accepted: 06/21/2005] [Indexed: 01/27/2023]
Abstract
We investigated the cAMP-dependent and -independent mechanisms of relaxation via beta-adrenoceptor in rat detrusor muscle with and without pre-contraction. A microdialysis technique was used to measure detrusor tension and cAMP level on the same detrusor tissue. In non-contracted tissue, isoproterenol, clenbuterol (beta2-adrenoceptor agonist) and FR165101, ((8S)-8-{[(2R)-2-(3-chlorophenyl)-2-hydroxyethyl]amino}-6,7,8,9-tetrahydro-5H-benzocyclohepten-2-yl)oxy]acetic acid hydrochloride (beta3-adrenoceptor agonist) relaxed detrusor muscle and cAMP levels also increased in a concentration dependent manner. SQ22536 (adenylyl cyclase inhibitor) markedly suppressed relaxation, suggesting that beta-adrenoceptor-mediated relaxation may be attributed mainly to cAMP-dependent mechanism. In high K+ pre-contracted tissue, although relaxation advanced in a concentration dependent manner, cAMP production reached a plateau at concentrations of more than 10(-7) M. SQ22536 had only a small inhibitory effect. However, large-conductance, Ca2+-activated K+ (BK(Ca)) channel inhibitors, charybdotoxin and iberiotoxin markedly suppressed relaxation. These results suggest that in addition to cAMP-dependent pathway, BK(Ca) channels are involved in the beta-adrenoceptor agonists-induced relaxation in pre-contracted detrusor muscle.
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Affiliation(s)
- Hisashi Uchida
- Department of Urology, Fukushima Medical University, 1 Hikarigaoka, Fukushima, 960-1295, Japan.
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Pelletier S, Julien C, Popoff MR, Lamarche-Vane N, Meloche S. Cyclic AMP induces morphological changes of vascular smooth muscle cells by inhibiting a Rac-dependent signaling pathway. J Cell Physiol 2005; 204:412-22. [PMID: 15706595 DOI: 10.1002/jcp.20308] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Cyclic AMP (cAMP) is a pleiotropic second messenger that regulates numerous cellular processes. In vascular smooth muscle cells (VSMCs), these include cell proliferation, migration, and contractility. Here we show that cAMP-elevating agents induce dramatic morphological changes in VSMCs, characterized by cell rounding and formation of long branching processes. The stellate morphology is associated with disassembly of actin stress fibers and lamellipodia, loss of focal adhesions, and the formation of small F-actin rings. Because of the importance of Rho family GTPases in regulating actin dynamics, we analyzed their individual roles in the cAMP phenotype. We found that pharmacological or genetic inhibition of Rac mimics cAMP effect in inducing a stellate morphology of VSMCs. Expression of activated Rac1 prevents forskolin-induced cAMP stellation, suggesting that cAMP affects cell morphology by inhibiting Rac function. Consistent with this, treatment with forskolin inhibits agonist-stimulated Rac activation in VSMCs. We further show that activated Rac1 containing the F37A effector loop substitution fails to rescue the cAMP phenotype. Our results suggest that cAMP modulates the morphology of VSMCs by inhibiting a Rac-dependent signaling pathway.
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Affiliation(s)
- Stéphane Pelletier
- Institut de Recherche en Immunovirologie et Cancérologie, Université de Montréal, Montreal, Quebec, Canada
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McLemore EC, Tessier DJ, Thresher J, Komalavilas P, Brophy CM. Role of the small heat shock proteins in regulating vascular smooth muscle tone. J Am Coll Surg 2005; 201:30-6. [PMID: 15978441 DOI: 10.1016/j.jamcollsurg.2005.03.017] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2004] [Revised: 03/01/2005] [Accepted: 03/01/2005] [Indexed: 10/25/2022]
Abstract
BACKGROUND Vasospasm occurs in conduits used for vascular reconstructions. The small heat shock proteins, HSP20 and HSP27, coordinately regulate vascular smooth muscle tone. Phosphorylated HSP20 is associated with vasorelaxation, and phosphorylated HSP27 inhibits the phosphorylation of HSP20 and relaxation. We hypothesized that the relationship between the phosphorylated states of these two proteins might dictate the tone of a vessel and may contribute to vasospasm. STUDY DESIGN Sodium nitroprusside relaxation of vascular smooth muscle was recorded using pig coronary artery and human saphenous vein. Segments were frozen and homogenized, and extracted proteins were separated by one- and two-dimensional gel electrophoresis, transferred to Immobilon (Millipore), and probed with anti-cGMP-dependent protein kinase (anti-PKG), -HSP20, -HSP27, and -phosphoHSP27 antibodies. Band intensity was estimated using densitometry. RESULTS Pig coronary artery completely relaxed (100%) with SNP (10(-7)M), but human saphenous vein only partially relaxed (20%). The levels of cGMP-dependent protein kinase and HSP20 were similar in the two tissue types. Human saphenous vein had significantly higher levels of HSP27 versus pig coronary artery (30.14 +/- 0.8 versus 6.62 +/- 0.2 pixels/mg; p < or = 0.001) and phosphoHSP27 (8.29 +/- 3.43 versus 0.012 +/- 0.008 pixels/mg; p < or = 0.001). CONCLUSIONS Human saphenous vein contained significantly higher levels of HSP27 and pHSP27. Increased levels of phosphorylated HSP27 might contribute to vasospasm in human saphenous vein.
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