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Baine S, Bonilla I, Belevych A, Stepanov A, Dorn LE, Terentyeva R, Terentyev D, Accornero F, Carnes CA, Gyorke S. Pyridostigmine improves cardiac function and rhythmicity through RyR2 stabilization and inhibition of STIM1-mediated calcium entry in heart failure. J Cell Mol Med 2021; 25:4637-4648. [PMID: 33755308 PMCID: PMC8107086 DOI: 10.1111/jcmm.16356] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 01/12/2021] [Accepted: 01/25/2021] [Indexed: 12/20/2022] Open
Abstract
Heart failure (HF) is characterized by asymmetrical autonomic balance. Treatments to restore parasympathetic activity in human heart failure trials have shown beneficial effects. However, mechanisms of parasympathetic-mediated improvement in cardiac function remain unclear. The present study examined the effects and underpinning mechanisms of chronic treatment with the cholinesterase inhibitor, pyridostigmine (PYR), in pressure overload HF induced by transverse aortic constriction (TAC) in mice. TAC mice exhibited characteristic adverse structural (left ventricular hypertrophy) and functional remodelling (reduced ejection fraction, altered myocyte calcium (Ca) handling, increased arrhythmogenesis) with enhanced predisposition to arrhythmogenic aberrant sarcoplasmic reticulum (SR) Ca release, cardiac ryanodine receptor (RyR2) hyper-phosphorylation and up-regulated store-operated Ca entry (SOCE). PYR treatment resulted in improved cardiac contractile performance and rhythmic activity relative to untreated TAC mice. Chronic PYR treatment inhibited altered intracellular Ca handling by alleviating aberrant Ca release and diminishing pathologically enhanced SOCE in TAC myocytes. At the molecular level, these PYR-induced changes in Ca handling were associated with reductions of pathologically enhanced phosphorylation of RyR2 serine-2814 and STIM1 expression in HF myocytes. These results suggest that chronic cholinergic augmentation alleviates HF via normalization of both canonical RyR2-mediated SR Ca release and non-canonical hypertrophic Ca signaling via STIM1-dependent SOCE.
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Affiliation(s)
- Stephen Baine
- College of Pharmacy, The Ohio State University, Columbus, OH, USA
| | - Ingrid Bonilla
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH, USA
| | - Andriy Belevych
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH, USA
| | - Andrei Stepanov
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH, USA
| | - Lisa E Dorn
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH, USA
| | - Radmila Terentyeva
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH, USA
| | - Dmitry Terentyev
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH, USA
| | - Federica Accornero
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH, USA
| | - Cynthia A Carnes
- College of Pharmacy, The Ohio State University, Columbus, OH, USA.,Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH, USA
| | - Sandor Gyorke
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH, USA
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2
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Baine S, Thomas J, Bonilla I, Ivanova M, Belevych A, Li J, Veeraraghavan R, Radwanski PB, Carnes C, Gyorke S. Muscarinic-dependent phosphorylation of the cardiac ryanodine receptor by protein kinase G is mediated by PI3K-AKT-nNOS signaling. J Biol Chem 2020; 295:11720-11728. [PMID: 32580946 PMCID: PMC7450129 DOI: 10.1074/jbc.ra120.014054] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 06/20/2020] [Indexed: 12/30/2022] Open
Abstract
Post-translational modifications of proteins involved in calcium handling in myocytes, such as the cardiac ryanodine receptor (RyR2), critically regulate cardiac contractility. Recent studies have suggested that phosphorylation of RyR2 by protein kinase G (PKG) might contribute to the cardioprotective effects of cholinergic stimulation. However, the specific mechanisms underlying these effects remain unclear. Here, using murine ventricular myocytes, immunoblotting, proximity ligation as-says, and nitric oxide imaging, we report that phosphorylation of Ser-2808 in RyR2 induced by the muscarinic receptor agonist carbachol is mediated by a signaling axis comprising phosphoinositide 3-phosphate kinase, Akt Ser/Thr kinase, nitric oxide synthase 1, nitric oxide, soluble guanylate cyclase, cyclic GMP (cGMP), and PKG. We found that this signaling pathway is compartmentalized in myocytes, as it was distinct from atrial natriuretic peptide receptor-cGMP-PKG-RyR2 Ser-2808 signaling and independent of muscarinic-induced phosphorylation of Ser-239 in vasodilator-stimulated phosphoprotein. These results provide detailed insights into muscarinic-induced PKG signaling and the mediators that regulate cardiac RyR2 phosphorylation critical for cardiovascular function.
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Affiliation(s)
- Stephen Baine
- College of Pharmacy, Ohio State University, Columbus, Ohio, USA
| | - Justin Thomas
- College of Pharmacy, Ohio State University, Columbus, Ohio, USA
| | - Ingrid Bonilla
- Department of Physiology and Cell Biology, Ohio State University, Columbus, Ohio, USA
| | - Marina Ivanova
- Department of Physiology and Cell Biology, Ohio State University, Columbus, Ohio, USA
| | - Andriy Belevych
- Department of Physiology and Cell Biology, Ohio State University, Columbus, Ohio, USA
| | - Jiaoni Li
- Department of Biomedical Engineering, Ohio State University, Columbus, Ohio, USA
| | | | | | - Cynthia Carnes
- College of Pharmacy, Ohio State University, Columbus, Ohio, USA
| | - Sandor Gyorke
- Department of Biomedical Engineering, Ohio State University, Columbus, Ohio, USA
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Gómez-Soto D, Galván S, Rosales E, Bienert P, Abreu I, Bonilla I, Bolaños L, Reguera M. Insights into the role of phytohormones regulating pAtNIP5;1 activity and boron transport in Arabidopsis thaliana. Plant Sci 2019; 287:110198. [PMID: 31481193 DOI: 10.1016/j.plantsci.2019.110198] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 07/17/2019] [Accepted: 07/21/2019] [Indexed: 05/29/2023]
Abstract
Aiming to counteract B deficiency impacts, plants have developed different strategies in order to reach an optimal growth in soils with limited B availability. These include B transport mechanisms that involves a facilitated transport, via channel proteins, and a high-affinity active transport driven by borate transporters. The AtNIP5;1 channel protein is a member of Major Intrinsic Protein family which facilitates B influx into the roots under low B supply. In order to explore the phytohormone-dependent regulation of AtNIP5;1, the effects of abscisic acid (ABA), ethylene, auxins and cytokinins on the activity of AtNIP5;1 promoter were evaluated using the reporter line pNIP5;1-GUS. The results show that ABA treatment increased pAtNIP5;1 activity. Besides, a larger B uptake was found following ABA treatment under B deficiency suggesting a role of ABA inducing B uptake. The ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC) caused an induction of AtNIP5;1 expression although did not correlate with higher B concentrations nor with an improvement in root growth. On the contrary, auxins and cytokinins caused slight changes in pAtNIP5;1 induction. Altogether, these results show a regulatory role of phytohormones in AtNIP5;1 promoter what may affect B transport. The herein provided information may contribute to better understand the regulation of B transport in plants towards minimizing B deficiency impacts on agriculture.
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Affiliation(s)
- D Gómez-Soto
- Departamento de Biología, Universidad Autónoma de Madrid, c/Darwin 2, Campus de Cantoblanco, 28049, Madrid, Spain
| | - S Galván
- Departamento de Biología, Universidad Autónoma de Madrid, c/Darwin 2, Campus de Cantoblanco, 28049, Madrid, Spain
| | - E Rosales
- Departamento de Biología, Universidad Autónoma de Madrid, c/Darwin 2, Campus de Cantoblanco, 28049, Madrid, Spain
| | - P Bienert
- IPK-Leibniz Institute of Plant Genetics and Crop Plant Research, Department of Physiology and Cell Biology, 06466, Gatersleben, Germany
| | - I Abreu
- Departamento de Biología, Universidad Autónoma de Madrid, c/Darwin 2, Campus de Cantoblanco, 28049, Madrid, Spain
| | - I Bonilla
- Departamento de Biología, Universidad Autónoma de Madrid, c/Darwin 2, Campus de Cantoblanco, 28049, Madrid, Spain
| | - L Bolaños
- Departamento de Biología, Universidad Autónoma de Madrid, c/Darwin 2, Campus de Cantoblanco, 28049, Madrid, Spain
| | - M Reguera
- Departamento de Biología, Universidad Autónoma de Madrid, c/Darwin 2, Campus de Cantoblanco, 28049, Madrid, Spain.
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Koleske M, Bonilla I, Thomas J, Zaman N, Baine S, Knollmann BC, Veeraraghavan R, Györke S, Radwański PB. Tetrodotoxin-sensitive Na vs contribute to early and delayed afterdepolarizations in long QT arrhythmia models. J Gen Physiol 2018; 150:991-1002. [PMID: 29793933 PMCID: PMC6028491 DOI: 10.1085/jgp.201711909] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 03/30/2018] [Accepted: 04/30/2018] [Indexed: 01/08/2023] Open
Abstract
Neuronal Na+ channels contribute to catecholaminergic polymorphic ventricular tachycardia in the heart, but their role in other types of arrhythmias is unknown. Koleske et al. show that they contribute to early and delayed afterdepolarizations common to long QT, catecholaminergic polymorphic ventricular tachycardia, and overlap phenotypes. Recent evidence suggests that neuronal Na+ channels (nNavs) contribute to catecholamine-promoted delayed afterdepolarizations (DADs) and catecholaminergic polymorphic ventricular tachycardia (CPVT). The newly identified overlap between CPVT and long QT (LQT) phenotypes has stoked interest in the cross-talk between aberrant Na+ and Ca2+ handling and its contribution to early afterdepolarizations (EADs) and DADs. Here, we used Ca2+ imaging and electrophysiology to investigate the role of Na+ and Ca2+ handling in DADs and EADs in wild-type and cardiac calsequestrin (CASQ2)-null mice. In experiments, repolarization was impaired using 4-aminopyridine (4AP), whereas the L-type Ca2+ and late Na+ currents were augmented using Bay K 8644 (BayK) and anemone toxin II (ATX-II), respectively. The combination of 4AP and isoproterenol prolonged action potential duration (APD) and promoted aberrant Ca2+ release, EADs, and DADs in wild-type cardiomyocytes. Similarly, BayK in the absence of isoproterenol induced the same effects in CASQ2-null cardiomyocytes. In vivo, it prolonged the QT interval and, upon catecholamine challenge, precipitated wide QRS polymorphic ventricular tachycardia that resembled human torsades de pointes. Treatment with ATX-II produced similar effects at both the cellular level and in vivo. Importantly, nNav inhibition with riluzole or 4,9-anhydro-tetrodotoxin reduced the incidence of ATX-II–, BayK-, or 4AP-induced EADs, DADs, aberrant Ca2+ release, and VT despite only modestly mitigating APD prolongation. These data reveal the contribution of nNaVs to triggered arrhythmias in murine models of LQT and CPVT-LQT overlap phenotypes. We also demonstrate the antiarrhythmic impact of nNaV inhibition, independent of action potential and QT interval duration, and provide a basis for a mechanistically driven antiarrhythmic strategy.
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Affiliation(s)
- Megan Koleske
- Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University Wexner Medical Center, Columbus, OH
| | - Ingrid Bonilla
- Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University Wexner Medical Center, Columbus, OH.,Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, OH
| | - Justin Thomas
- Division of Pharmacy Practice and Sciences, College of Pharmacy, The Ohio State University, Columbus, OH
| | - Naveed Zaman
- Division of Pharmacology, College of Pharmacy, The Ohio State University, Columbus, OH
| | - Stephen Baine
- Division of Pharmacology, College of Pharmacy, The Ohio State University, Columbus, OH
| | - Bjorn C Knollmann
- Division of Clinical Pharmacology, Vanderbilt University Medical School, Nashville, TN
| | - Rengasayee Veeraraghavan
- Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University Wexner Medical Center, Columbus, OH.,Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, OH
| | - Sándor Györke
- Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University Wexner Medical Center, Columbus, OH.,Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, OH
| | - Przemysław B Radwański
- Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University Wexner Medical Center, Columbus, OH .,Division of Pharmacy Practice and Sciences, College of Pharmacy, The Ohio State University, Columbus, OH.,Division of Pharmacology, College of Pharmacy, The Ohio State University, Columbus, OH
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5
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Liu B, Walton SD, Ho HT, Belevych AE, Tikunova SB, Bonilla I, Shettigar V, Knollmann BC, Priori SG, Volpe P, Radwański PB, Davis JP, Györke S. Gene Transfer of Engineered Calmodulin Alleviates Ventricular Arrhythmias in a Calsequestrin-Associated Mouse Model of Catecholaminergic Polymorphic Ventricular Tachycardia. J Am Heart Assoc 2018; 7:JAHA.117.008155. [PMID: 29720499 PMCID: PMC6015318 DOI: 10.1161/jaha.117.008155] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Background Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a familial arrhythmogenic syndrome characterized by sudden death. There are several genetic forms of CPVT associated with mutations in genes encoding the cardiac ryanodine receptor (RyR2) and its auxiliary proteins including calsequestrin (CASQ2) and calmodulin (CaM). It has been suggested that impairment of the ability of RyR2 to stay closed (ie, refractory) during diastole may be a common mechanism for these diseases. Here, we explore the possibility of engineering CaM variants that normalize abbreviated RyR2 refractoriness for subsequent viral‐mediated delivery to alleviate arrhythmias in non–CaM‐related CPVT. Methods and Results To that end, we have designed a CaM protein (GSH‐M37Q; dubbed as therapeutic CaM or T‐CaM) that exhibited a slowed N‐terminal Ca dissociation rate and prolonged RyR2 refractoriness in permeabilized myocytes derived from CPVT mice carrying the CASQ2 mutation R33Q. This T‐CaM was introduced to the heart of R33Q mice through recombinant adeno‐associated viral vector serotype 9. Eight weeks postinfection, we performed confocal microscopy to assess Ca handling and recorded surface ECGs to assess susceptibility to arrhythmias in vivo. During catecholamine stimulation with isoproterenol, T‐CaM reduced isoproterenol‐promoted diastolic Ca waves in isolated CPVT cardiomyocytes. Importantly, T‐CaM exposure abolished ventricular tachycardia in CPVT mice challenged with catecholamines. Conclusions Our results suggest that gene transfer of T‐CaM by adeno‐associated viral vector serotype 9 improves myocyte Ca handling and alleviates arrhythmias in a calsequestrin‐associated CPVT model, thus supporting the potential of a CaM‐based antiarrhythmic approach as a therapeutic avenue for genetically distinct forms of CPVT.
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Affiliation(s)
- Bin Liu
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, Ohio State University, Columbus, OH.,Department of Biological Sciences, Mississippi State University, Starkville, MI
| | - Shane D Walton
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, Ohio State University, Columbus, OH
| | - Hsiang-Ting Ho
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, Ohio State University, Columbus, OH
| | - Andriy E Belevych
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, Ohio State University, Columbus, OH
| | - Svetlana B Tikunova
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, Ohio State University, Columbus, OH
| | - Ingrid Bonilla
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, Ohio State University, Columbus, OH
| | - Vikram Shettigar
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, Ohio State University, Columbus, OH
| | - Bjorn C Knollmann
- Division of Clinical Pharmacology, Vanderbilt University School of Medicine, Vanderbilt, TN
| | - Silvia G Priori
- Division of Cardiology and Molecular Cardiology, Maugeri Foundation-University of Pavia, Italy
| | - Pompeo Volpe
- Department of Biomedical Sciences, University of Padova, Italy
| | - Przemysław B Radwański
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, Ohio State University, Columbus, OH
| | - Jonathan P Davis
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, Ohio State University, Columbus, OH
| | - Sándor Györke
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, Ohio State University, Columbus, OH
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Klauber-DeMore N, Bonilla I, Nassar P, Hilliard E, Molano I, Spruill L. Abstract P3-06-01: Not presented. Cancer Res 2018. [DOI: 10.1158/1538-7445.sabcs17-p3-06-01] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
This abstract was not presented at the symposium.
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Affiliation(s)
| | - I Bonilla
- Medical University of South Carolina, Charleston, SC
| | - P Nassar
- Medical University of South Carolina, Charleston, SC
| | - E Hilliard
- Medical University of South Carolina, Charleston, SC
| | - I Molano
- Medical University of South Carolina, Charleston, SC
| | - L Spruill
- Medical University of South Carolina, Charleston, SC
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7
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Campos-Delgado DU, Bonilla I, Rodríguez-Martínez M, Sánchez-Briones ME, Ruiz-Hernández E. Closed-loop control of renal perfusion pressure in physiological experiments. IEEE Trans Biomed Eng 2013; 60:1776-84. [PMID: 23358945 DOI: 10.1109/tbme.2013.2241435] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
This paper presents the design, experimental modeling, and control of a pump-driven renal perfusion pressure (RPP)-regulatory system to implement precise and relatively fast RPP regulation in rats. The mechatronic system is a simple, low-cost, and reliable device to automate the RPP regulation process based on flow-mediated occlusion. Hence, the regulated signal is the RPP measured in the left femoral artery of the rat, and the manipulated variable is the voltage applied to a dc motor that controls the occlusion of the aorta. The control system is implemented in a PC through the LabView software, and a data acquisition board NI USB-6210. A simple first-order linear system is proposed to approximate the dynamics in the experiment. The parameters of the model are chosen to minimize the error between the predicted and experimental output averaged from eight input/output datasets at different RPP operating conditions. A closed-loop servocontrol system based on a pole-placement PD controller plus dead-zone compensation was proposed for this purpose. First, the feedback structure was validated in simulation by considering parameter uncertainty, and constant and time-varying references. Several experimental tests were also conducted to validate in real time the closed-loop performance for stepwise and fast switching references, and the results show the effectiveness of the proposed automatic system to regulate the RPP in the rat, in a precise, accurate (mean error less than 2 mmHg) and relatively fast mode (10-15 s of response time).
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Affiliation(s)
- D U Campos-Delgado
- Facultad de Ciencias, Av. Salvador Nava s/n, Zona Universitaria, San Luis Potosi, SLP 78290, Mexico.
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Belevych AE, Ho HT, Lou Q, Vargas-Pinto P, Bonilla I, Fedorov VV, Carnes CA, Gyorke S. Remodeling of Atrial Ca Handling in Canine Model of Chronic Heart Failure Points to Non-Triggered Mechanisms of Atrial Fibrillation. Biophys J 2013. [DOI: 10.1016/j.bpj.2012.11.1145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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Long V, Bonilla I, Vargas Pinto P, Green J, Nishijima Y, Mowrey K, Fedorov V, Weiss R, Carnes C. Atrial Electrophysiologic Remodeling in Canine Heart Failure: Modulation by Atrial Fibrillation. Heart Rhythm 2012. [DOI: 10.1016/j.hrthm.2012.09.099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Nishijima Y, Sridhar A, Bonilla I, Velayutham M, Khan M, Terentyeva R, Li C, Kuppusamy P, Elton TS, Terentyev D, Györke S, Zweier JL, Cardounel AJ, Carnes CA. Tetrahydrobiopterin depletion and NOS2 uncoupling contribute to heart failure-induced alterations in atrial electrophysiology. Cardiovasc Res 2011; 91:71-9. [PMID: 21460065 PMCID: PMC3112023 DOI: 10.1093/cvr/cvr087] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2010] [Revised: 02/24/2011] [Accepted: 03/25/2011] [Indexed: 01/14/2023] Open
Abstract
AIMS Heart failure is a common antecedent to atrial fibrillation; both heart failure and atrial fibrillation are associated with increased myocardial oxidative stress. Chronic canine heart failure reduces atrial action potential duration and atrial refractoriness. We hypothesized that inducible nitric oxide synthase 2 (NOS2) contributes to atrial oxidative stress and electrophysiologic alterations. METHODS AND RESULTS A 16-week canine tachypacing model of heart failure was used (n= 21). At 10 weeks, dogs were randomized to either placebo (n = 12) or active treatment (n = 9) with NOS cofactor, tetrahydrobiopterin (BH(4), 50 mg), and NOS substrate (L-arginine, 3 g) twice daily for 6 weeks. A group of matched controls (n = 7) was used for comparison. Heart failure increased atrial NOS2 and reduced atrial BH(4), while L-arginine was unchanged. Treatment reduced inducible atrial fibrillation and normalized the heart failure-induced shortening of the left atrial myocyte action potential duration. Treatment increased atrial [BH(4)] while [L-arginine] was unchanged. Treatment did not improve left ventricular function or dimensions. Heart failure-induced reductions in atrial [BH(4)] resulted in NOS uncoupling, as measured by NO and superoxide anion (O(2)(·-)) production, while BH(4) and L-arginine treatment normalized NO and O(2)(·-). Heart failure resulted in left atrial oxidative stress, which was attenuated by BH(4) and L-arginine treatment. CONCLUSION Chronic non-ischaemic heart failure results in atrial oxidative stress and electrophysiologic abnormalities by depletion of BH(4) and uncoupling of NOS2. Modulation of NOS2 activity by repletion of BH(4) may be a safe and effective approach to reduce the frequency of atrial arrhythmias during heart failure.
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Affiliation(s)
- Yoshinori Nishijima
- College of Pharmacy, The Ohio State University, 500 W. 12th Avenue, Columbus, OH 43210, USA
| | - Arun Sridhar
- Glaxo Smith Kline, Park Road, Ware, Herts SG12 0DP, UK
| | - Ingrid Bonilla
- College of Pharmacy, The Ohio State University, 500 W. 12th Avenue, Columbus, OH 43210, USA
| | - Murugesan Velayutham
- Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210, USA
- Center for Biomedical EPR Spectroscopy and Imaging, Division of Cardiovascular Medicine, Department of Internal Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Mahmood Khan
- Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210, USA
- Center for Biomedical EPR Spectroscopy and Imaging, Division of Cardiovascular Medicine, Department of Internal Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Radmila Terentyeva
- Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210, USA
| | - Chun Li
- College of Pharmacy, The Ohio State University, 500 W. 12th Avenue, Columbus, OH 43210, USA
| | - Periannan Kuppusamy
- Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210, USA
- Center for Biomedical EPR Spectroscopy and Imaging, Division of Cardiovascular Medicine, Department of Internal Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Terry S. Elton
- College of Pharmacy, The Ohio State University, 500 W. 12th Avenue, Columbus, OH 43210, USA
- Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210, USA
| | - Dmitry Terentyev
- Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210, USA
| | - Sandor Györke
- Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210, USA
| | - Jay L. Zweier
- Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210, USA
- Center for Biomedical EPR Spectroscopy and Imaging, Division of Cardiovascular Medicine, Department of Internal Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Arturo J. Cardounel
- Department of Anesthesiology, The Ohio State University, Columbus, OH 43210, USA
| | - Cynthia A. Carnes
- College of Pharmacy, The Ohio State University, 500 W. 12th Avenue, Columbus, OH 43210, USA
- Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210, USA
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López-Fabal F, Culebras E, Bonilla I, Gómez M, Picazo JJ. [In vitro activities of colistin combinations against Pseudomonas aeruginosa isolated from the intensive care unit]. Rev Esp Quimioter 2008; 21:189-193. [PMID: 18792821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Introduction. As the number of multidrug-resistant strains of Pseudomonas aeruginosa has risen in the intensive care unit (ICU) of the San Carlos Clinic Hospital, 12 consecutive isolates from different patients were collected to determine the possibility of an epidemic outbreak caused by the spread of a single strain. We determined the antimicrobial susceptibility to the most common agents used in the treatment of infections caused by this bacteria. The results of susceptibility studies suggest that different strains of P. aeruginosa are responsible for the respiratory tract infections in ICU. Methods. The clonal relationship between the isolates using was determined using BOX and ERIC primers by means of repetitive sequence-based polymerase chain reaction (rep-PCR). The in vitro activity of these strains against colistin, rifampicin, doxicycline and azythromycin was studied to determine in which cases the combination of colistin with any of the other three antibiotics was synergistic. Results. Sensitivity studies point out the presence of several strains of P. aeruginosa as the causal agents of respiratory infections produced by this microorganism in the ICU. Combinations of colistin with doxycicline and colistin with azithromycin were synergistic for some isolates in the synergy studies. Discussion. Clonal studies reveal the presence of five different clones among our isolates. Therefore we can conclude that there was no outbreak of P. aeruginosa in the ICU. Synergistic activity of combinations of colistin plus azithromycin, colistin plus doxicycline and colistin plus rifampicin was less than expected and a high percentage of indifferent results was observed.
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Affiliation(s)
- F López-Fabal
- Servicio de Microbiología, Hospital Clínico San Carlos, Madrid.
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Monteseirín J, Fernández-Pineda I, Chacón P, Vega A, Bonilla I, Camacho MJ, Fernández-Delgado L, Conde J, Sobrino F. Myeloperoxidase release after allergen-specific conjunctival challenge. J Asthma 2005; 41:639-43. [PMID: 15584313 DOI: 10.1081/jas-200026407] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
BACKGROUND Allergen-specific conjunctival challenge is a fruitful and complete tool in evaluating pathophysiological phenomena of allergic inflammation. After challenge, a significant neutrophil infiltrate occurred in allergic subjects. The primary (azurophilic) granules of neutrophils contain a variety of enzymes that might potentiate inflammation, such as myeloperoxidase (MPO). It is not known whether allergen-specific conjunctival challenge (ASCC) is able to elicit MPO release. We also investigated the possible role of immunotherapy (IT) in the release of MPO. METHOD The groups studied included Dactylis glomerata-sensitive adult atopic patients suffering from seasonal allergic rhinoconjunctivitis, and healthy adult nonatopic volunteer controls. One group of allergic patients received no specific hyposensitization (not-IT allergic group). A second group of allergic patients had been immunotherapy-treated with Dactylis glomerata extract for the preceding three years and continued to receive a maintenance dose within the highest potency of the extract (IT-allergic group). ASCC with Dactylis glomerata was performed outside the pollen season in all subjects. Myeloperoxidase was assayed by MPO-enzyme immunoassay method. RESULTS Thirty minutes after challenge, myeloperoxidase levels in the non-immunotherapy allergic patients were significantly higher compared than in the healthy group (p<0.001). The levels of myeloperoxidase released in the immunotherapy allergic group were significantly lower than those in the nonimmunotherapy allergic group (p<0.001) and higher than those in nonallergic subjects (p<0.001). CONCLUSION These results indicate that after ASCC there is a release of MPO. Our study suggests that immunotherapy actively modifies the release of MPO after ASCC.
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Affiliation(s)
- J Monteseirín
- Department of Medicine, Regional Service of Immunology and Allergy, Hospital Universitario Virgen Macarena, Spain.
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Torrecilla I, Leganés F, Bonilla I, Fernández-Piñas F. A calcium signal is involved in heterocyst differentiation in the cyanobacterium Anabaena sp. PCC7120. Microbiology (Reading) 2004; 150:3731-3739. [PMID: 15528659 DOI: 10.1099/mic.0.27403-0] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The impact of calcium signals in virtually all cells has led to the study of their role in prokaryotic organisms as stress response modulators. Cell differentiation in adverse conditions is a common Ca2+-requiring response. Nitrogen starvation induces the differentiation of N2-fixing heterocysts in the filamentous cyanobacterium Anabaena sp. PCC7120. This paper reports the use of a recombinant strain of this organism expressing the photoprotein aequorin to monitor the intracellular free-calcium concentration during the course of heterocyst differentiation. A specific calcium signature that is triggered exclusively when cells are deprived of combined nitrogen and generated by intracellular calcium stores was identified. The intracellular calcium signal was manipulated by treatment with specific calcium drugs, and the effect of such manipulation on the process of heterocyst differentiation was subsequently assessed. Suppression, magnification or poor regulation of this signal prevented the process of heterocyst differentiation, thereby suggesting that a calcium signal with a defined set of kinetic parameters may be required for differentiation. A hetR mutant of Anabaena sp. PCC7120 that cannot differentiate into heterocysts retains, however, the capacity to generate the calcium transient in response to nitrogen deprivation, strongly suggesting that Ca2+ may be involved in a very early step of the differentiation process.
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Affiliation(s)
- I Torrecilla
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid 28049, Spain
| | - F Leganés
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid 28049, Spain
| | - I Bonilla
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid 28049, Spain
| | - F Fernández-Piñas
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid 28049, Spain
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Candel FJ, Alramadan M, Bonilla I, Matesanz M, Merino P, Candel I, Roca-Arbonés V, Picazo de la Garza JJ. [Malaria, a growing disease. Analysis of the 15-year period 1997-2001 in a Madrid hospital]. An Med Interna 2004; 21:49-50. [PMID: 15195493 DOI: 10.4321/s0212-71992004000100018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
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Monteseirín J, Bonilla I, Chacón P, Vega A, Camacho MJ, Guardia P, Conde J, Sobrino F. Allergen-dependent CD14 modulation and apoptosis in monocytes from allergic patients. Allergy 2003; 58:1027-32. [PMID: 14510721 DOI: 10.1034/j.1398-9995.2003.00249.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND CD14 is a most important monocyte surface molecule. Recently, it has been reported that there is an important relationship between CD14 and immunoglobulin E, and that regulation of CD14 expression is an effector mechanism mediating apoptosis of monocytes. OBJECTIVE The present study was designed to determine whether specific allergens were able to modulate CD14 expression and apoptosis by monocytes from allergic patients or whether specific immunotherapy (IT) might affect these processes. METHODS One group of adult allergic asthmatic patients had received IT for the previous 3 years. Another similar group was not treated with IT. We challenged peripheral blood monocytes from both groups of asthmatic patients in vitro with the specific allergen that produced clinical symptoms in asthmatic patients. The cells were also challenged with allergen to which the patients were not sensitive. Monocytes from normal subjects were also challenged with allergens. Expression of CD14 on the monocyte surface was analyzed by flow cytometry, and soluble CD14 (sCD14) in culture supernatant by enzyme-linked immunosorbent assay. The three groups of subjects were challenged with allergens, and apoptosis was analyzed by flow cytometry. RESULTS When monocytes from non-IT-treated asthmatic patients were cultivated with the allergens to which the patients were sensitive, a significant up-regulation on the monocyte surface was observed compared with results from the healthy group (P < 0.003) and from the IT asthmatic group (P < 0.003). A significantly higher sCD14 level was observed in the culture supernatant of the monocytes from the IT asthmatic group were observed compared with those from the healthy group (P < 0.001) and those from the non-IT asthmatic group (P < 0.001). A significantly higher apoptosis level was observed in monocytes from the IT asthmatic group compared with those from the healthy group (P < 0.001) and those from the non-IT asthmatic group (<0.001). CONCLUSIONS We present evidence that the expression of CD14 on the surface of monocytes and the apoptosis of the same cells can be modulated by an allergen-dependent mechanism. These processes can be affected by IT.
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Affiliation(s)
- J Monteseirín
- Departamento de Medicina, Servicio Regional de Inmunología y Alergia, Hospital Universitario Virgen Macarena, Spain
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Affiliation(s)
- J Monteseirín
- Departamento de Medicina, Servicio Regional de Inmunología y Alergia, Hospital Universitario Virgen Macarena, Facultad de Medicina, Universidad de Sevilla, Spain.
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Abstract
BACKGROUND The role of oxygen radicals has been implicated in disease processes of asthma. We have previously shown that specific allergens were able to activate respiratory burst by neutrophils from allergic patients sensitized to allergens of the same type as those which produce clinical allergy. OBJECTIVES In this study, we attempted to evaluate the production of respiratory burst by an anti-IgE Ab in neutrophils from asthmatic allergic patients (with and without immunotherapy treatment) and in neutrophils from healthy subjects. METHOD Neutrophils were stimulated by 10 microg/mL of anti-IgE Ab for 15 min at 37 degrees C. The production of respiratory burst from neutrophils was assayed by luminol-amplified chemiluminescence method. RESULTS The respiratory burst was significantly higher in neutrophils from non-IT-asthmatic patients than in neutrophils from both healthy (p < 0.001) and IT-asthmatic (p < 0.001) groups. The IT-asthmatic group presented levels of respiratory burst approximately equal to those from non-allergic subjects (p=0.426). CONCLUSIONS We conclude that neutrophils obtained from allergic asthmatic patients have an increased propensity to generate respiratory bursts, in comparison with neutrophils from healthy subjects. Immunotherapy actively modifies the respiratory burst by neutrophils from allergic asthmatic patients.
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Affiliation(s)
- J Monteseirín
- Departamento de Medicina, Servicio Regional de Immunología y Alergia, Hospital Universitario Virgen Macarena, Spain.
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Monteseirín J, Pérez-Formoso JL, Sánchez-Hernández MC, Hernández M, Bonilla I, Camacho MJ, Guardia P, Conde J. Occupational contact dermatitis from canary-grass seed. Contact Dermatitis 2002; 47:247. [PMID: 12492538 DOI: 10.1034/j.1600-0536.2002.470419_2.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- J Monteseirín
- Departamento de Medicina, Servicio Regional de Inmunología y Alergia, Hospital Universitario Virgen Macarena, Facultad de Medicina, Universidad de Sevilla, Spain
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Abstract
BACKGROUND The three forms of IgE receptor: the heterotrimeric high-affinity receptor for IgE (FcepsilonRI), the low-affinity receptor for IgE (FcepsilonRII/CD23) and the Mac-2/IgE-binding protein (epsilonBP), have previously been found on human neutrophils. We have previously shown that specific allergens are able to activate functional responses by neutrophils from allergic patients sensitized to those allergens. Neutrophils are present in the sites of allergic inflammation. The primary (azurophilic) granules of neutrophils contain a variety of enzymes that might potentiate inflammation, such as myeloperoxidase (MPO). It is not known whether specific allergens are able to elicit MPO release by neutrophils from allergic patients. METHODS Neutrophils were challenged in vitro with the specific allergen that produced clinical symptoms in asthmatic patients. Also, the cells were challenged with allergens that the patients were not sensitive to. Neutrophils from normal subjects were also challenged with allergens. RESULTS The in vitro challenge of neutrophils with allergens that the patients were sensitive to elicited a release of MPO by these cells. The in vitro activation of neutrophils was highly allergen-specific, in such a way that allergens other than those accounting for clinical symptoms did not evoke MPO release, and allergens were ineffective on neutrophils from healthy donors. CONCLUSION An IgE-dependent mechanism might promote MPO release by neutrophils at allergic sites.
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Affiliation(s)
- J Monteseirín
- Departamento de Medicina, Servicio Regional de Inmunología y Alergia, Hospital Universitario Virgen Macarena, Spain.
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Bolaños L, Cebrián A, Redondo-Nieto M, Rivilla R, Bonilla I. Lectin-like glycoprotein PsNLEC-1 is not correctly glycosylated and targeted in boron-deficient pea nodules. Mol Plant Microbe Interact 2001; 14:663-70. [PMID: 11332730 DOI: 10.1094/mpmi.2001.14.5.663] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Symbiosome development was studied in pea root nodules from plants growing in the absence of boron (B). Rhizobia released into the host cells of nodules from B-deficient plants developed to abnormal endophytic forms with an altered electrophoretic lipopolysaccharide pattern. Immunostaining after sodium dodecyl sulfate-polyacrylamide gel electrophoresis and electroblotting of nodule homogenates with antibodies that recognize glycoprotein components showed that two previously described lectin-like glycoproteins (PsNLEC-1A and PsNLEC-1B) did not harbor the carbohydrate epitope normally recognized by specific monoclonal antibodies. Material derived from B-deficient nodules, however, still contained three antigenic isoforms with similar electrophoretic mobilities to PsNLEC-1 isoforms A, B, and C. These could be detected following immunoblotting and immunostaining with a specific antiserum originating from the purified PsNLEC protein that had been heterologously expressed in Escherichia coli. Immunogold localization of PsNLEC-1 sugar epitopes in B-deficient nodules showed that they were associated mostly with cytoplasmic vesicles rather than normal localization in the symbiosome compartment of mature infected cells. These results suggest that a modification of the glycosyl-moieties of PsNLEC-1 and an alteration of vesicle targeting occur during the development of pea nodules in the absence of B, and that these changes are associated with the development of aberrant nonfunctional symbiosomes.
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Affiliation(s)
- L Bolaños
- Departmento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, Spain
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Monteseirín J, Bonilla I, Camacho J, Conde J, Sobrino F. Elevated secretion of myeloperoxidase by neutrophils from asthmatic patients: the effect of immunotherapy. J Allergy Clin Immunol 2001; 107:623-6. [PMID: 11295649 DOI: 10.1067/mai.2001.113566] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND There is increasing evidence of neutrophil participation in asthma and the allergic process. After activation, neutrophils release myeloperoxidase (MPO) together with other granule enzymes. OBJECTIVES In this study we attempted to evaluate the release of MPO in vitro by neutrophils from asthmatic patients and the relationship between neutrophil degranulation and lung function, measured as FEV(1), of the patients. We also investigated the possible role of immunotherapy in the release of MPO by neutrophils. METHODS Neutrophils were stimulated with formyl-methionyl-leucyl-phenylalanine for 45 minutes at 37 degrees C. MPO released from neutrophils was assayed by using an MPO enzyme immunoassay. RESULTS Neutrophils released statistically significantly higher MPO levels in the asthmatic patients not receiving immunotherapy than in the healthy group. A significant inverse correlation was observed in the asthmatic group not receiving immunotherapy between MPO secretion and lung function, measured as FEV(1), of the patients. Neutrophils of the asthmatic group receiving immunotherapy released significantly less MPO than did those of the asthmatic group not receiving immunotherapy, with MPO levels equal to those from nonallergic subjects. CONCLUSIONS We conclude that neutrophils obtained from allergic asthmatic patients have an increased propensity to release MPO. The experiments described here provide evidence that there is a significant inverse relationship between levels of MPO released by neutrophils from allergic patients and lung function, as assessed by FEV(1). Our study suggests that immunotherapy actively modifies the release of MPO in vitro by neutrophils from allergic asthmatic patients.
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Affiliation(s)
- J Monteseirín
- Departamento de Medicina, Servicio Regional de Inmunología y Alergia, Hospital Universitario Virgen Macarena, Universidad de Sevilla, Seville, Spain
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Monteseirín J, Llamas E, Sánchez-Monteseirín H, Bonilla I, Camacho MJ, Conde J, Sobrino F. IgE-mediated downregulation of L-selectin (CD62L) on lymphocytes from asthmatic patients. Allergy 2001; 56:164-8. [PMID: 11167378 DOI: 10.1034/j.1398-9995.2001.056002164.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND L-selectin (CD62L) mediates the binding of lymphocytes to high endothelial venules of peripheral lymph nodes and is also involved in leukocyte attachment to the endothelium at sites of inflammation. Although it has been demonstrated that L-selectin is shed after lymphocyte activation, it is unknown whether the expression of L-selectin on the surface of lymphocytes can be modulated by an IgE-dependent mechanism or whether immunotherapy (IT) might affect this mechanism. METHODS One group of adult allergic asthmatic patients had received IT for the previous 3 years. Another similar group was not treated with IT. We challenged peripheral blood lymphocytes from both groups of asthmatic patients in vitro with an anti-IgE antibody (Ab). Expression of L-selectin on the lymphocyte surface was analyzed by flow cytometry, and the levels of soluble L-selectin (sL-selectin) on culture supernatant by ELISA. RESULTS L-selectin was downregulated from the surface of lymphocytes in a time- and anti-IgE antibody dose-dependent manner (with a concomitant upregulation of shed L-selectin in the supernatant). When lymphocytes from non-IT asthmatic patients were cultivated with anti-IgE Ab, a statistically significantly greater CD62L downmodulation on the lymphocyte surface was observed compared with lymphocytes from the healthy group (P<0.002) and from the IT-asthmatic group (P<0.001). When lymphocytes from non-IT asthmatic patients were cultivated with anti-IgE Ab, a significantly greater sL-selectin level in the culture supernatant was observed compared with lymphocytes from the healthy group (P<0.001) and with lymphocytes from IT-asthmatic group (P<0.001). CONCLUSIONS We present evidence that the expression of L-selectin on the surface of lymphocytes can be modulated by an IgE-dependent mechanism. This mechanism can be affected by IT.
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Affiliation(s)
- J Monteseirín
- Departamento de Medicina, Hospital Universitario Virgen Macarena, Spain
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Sánchez-Contreras M, Lloret J, Martín M, Villacieros M, Bonilla I, Rivilla R. PCR use of highly conserved DNA regions for identification of Sinorhizobium meliloti. Appl Environ Microbiol 2000; 66:3621-3. [PMID: 10919829 PMCID: PMC92193 DOI: 10.1128/aem.66.8.3621-3623.2000] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A PCR identification method in which four primers that recognize homologous conserved regions in the Sinorhizobium meliloti genome are used was developed and tested. The regions used for identification were the nodbox 4 locus, which is located in one of the symbiotic megaplasmids, and the mucR gene, which is located in the chromosome. The new method was used to establish a collection of S. meliloti strains from polluted soils.
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Affiliation(s)
- M Sánchez-Contreras
- Departamento de Biología, Universidad Autónoma de Madrid, 28049 Madrid, Spain
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26
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Torrecilla I, Leganés F, Bonilla I, Fernández-Piñas F. Use of recombinant aequorin to study calcium homeostasis and monitor calcium transients in response to heat and cold shock in cyanobacteria. Plant Physiol 2000; 123:161-76. [PMID: 10806234 PMCID: PMC58991 DOI: 10.1104/pp.123.1.161] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/1999] [Accepted: 01/21/2000] [Indexed: 05/23/2023]
Abstract
We investigated the possibility of Ca(2+) signaling in cyanobacteria (blue-green algae) by measuring intracellular free Ca(2+) levels ([Ca(2+)](i)) in a recombinant strain of the nitrogen fixing cyanobacterium Anabaena strain sp. PCC7120, which constitutively expresses the Ca(2+)-binding photoprotein apoaequorin. The homeostasis of intracellular Ca(2+) in response to increasing external Ca(2+) has been studied in this strain. The resting level of free Ca(2+) in Anabaena was found to be between 100 and 200 nM. Additions of increasing concentrations of external Ca(2+) gave a transient burst of [Ca(2+)](i) followed by a very quick decline, reaching a plateau within seconds that brought the level of [Ca(2+)](i) back to the resting value. These results indicate that Anabaena strain sp. PCC7120 is able to regulate its internal Ca(2+) levels. We also monitored Ca(2+) transients in our recombinant strain in response to heat and cold shock. The cell's response to both stresses was dependent on the way they were induced. The use of inhibitors suggests that heat shock mobilizes cytosolic Ca(2+) from both intracellular and extracellular sources, while the Ca(2+) source for cold shock signaling is mostly extracellular.
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Affiliation(s)
- I Torrecilla
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, Spain
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Martín M, Lloret J, Sánchez-Contreras M, Bonilla I, Rivilla R. MucR is necessary for galactoglucan production in Sinorhizobium meliloti EFB1. Mol Plant Microbe Interact 2000; 13:129-135. [PMID: 10656595 DOI: 10.1094/mpmi.2000.13.1.129] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Sinorhizobium meliloti can produce two types of acidic exopolysaccharides, succinoglycan and galactoglucan, that are interchangeable for infection of alfalfa nodules. Strain SU47 and derivatives produce only succinoglycan, unless it grows under phosphate limitation or carries a mutation in either of two regulatory loci, mucR or expR. It has been proposed that MucR acts as a transcriptional repressor that blocks the expression of the exp genes responsible for galactoglucan production. Strain EFB1 simultaneously produces both exopolysaccharides. Heterologous expression of lacZ transcriptional fusions of the expE promoters has shown that genetic background is more important that promoter sequence for exp gene expression, since expE promoters from both strains are expressed at high level in EFB1 and not in SU47. We have found that mucR is present in mucoid and nonmucoid strains, and in EFB1 differs from SU47 in only one conservative amino acid change. MucR proteins from both strains are interchangeable. An mucR mutant of EFB1 cannot produce galactoglucan and does not express mucS.
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Affiliation(s)
- M Martín
- Departamento de Biología, Universidad Autónoma de Madrid, Spain
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28
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Giraldez-Ruiz N, Bonilla I, Fernandez-Piñas F. Role of external calcium in homeostasis of intracellular pH in the cyanobacterium Anabaena sp. strain PCC7120 exposed to low pH. New Phytol 1999; 141:225-230. [PMID: 33862921 DOI: 10.1046/j.1469-8137.1999.00347.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The role of external Ca2+ in the homeostasis of intracellular pH (pHi) of Anabaena sp. strain PCC7120 in response to a decrease in the external pH (pHex) has been studied in cell suspensions. Increase in cytoplasmic pH after acid shock is dependent on the presence of Ca2+ in the medium. The observed Ca2+ -mediated alkalization of the cytoplasm depends on the extent of the shift in external pH. Acid pH shifts resulted in an increased permeability of the cytoplasmic membrane to protons, which could be reversed by increasing the concentration of Ca2+ in the medium. Thus, the ability of Ca2+ to increase cytoplasmic pH might be correlated with an inhibition of net proton uptake by increasing concentrations of external Ca2+ under these conditions. This combined response resulted in the generation and maintenance of a larger pH gradient (ΔpH) at acid external pH values. All Ca2+ channel blockers tested, such as verapamil and LaCl3 , inhibited the observed Ca2+ -mediated response. On the other hand, the Ca ionophore calcimycin (compound A23187) was agonistic, and stimulated both cytoplasmic alkalization and inhibition of net proton uptake. The protonophorous uncoupler carbonylcyanide m-chlorophenyl hydrazone, inhibited this Ca2+ -mediated response, whereas monensin, an inhibitor of the Na+ /H+ antiporter, had no significant effect. The results of the present study suggest that an influx of Ca2+ from the extracellular space is required for the regulation of cytoplasmic pH in Anabaena sp. strain PCC7120 exposed to low external pH values.
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Affiliation(s)
- N Giraldez-Ruiz
- 1 Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - I Bonilla
- 1 Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - F Fernandez-Piñas
- 1 Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, 28049 Madrid, Spain
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Lloret J, Wulff BB, Rubio JM, Downie JA, Bonilla I, Rivilla R. Exopolysaccharide II production is regulated by salt in the halotolerant strain Rhizobium meliloti EFB1. Appl Environ Microbiol 1998; 64:1024-8. [PMID: 9501442 PMCID: PMC106361 DOI: 10.1128/aem.64.3.1024-1028.1998] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The halotolerant strain Rhizobium meliloti EFB1 modifies the production of extracellular polysaccharides in response to salt. EFB1 colonies grown in the presence of 0.3 M NaCl show a decrease in mucoidy, and in salt-supplemented liquid medium this organism produces 40% less exopolysaccharides. We isolated transposon-induced mutant that, when grown in the absence of salt, had a colony morphology (nonmucoid) similar to the colony morphology of the wild type grown in the presence of salt. Calcofluor fluorescence, proton nuclear magnetic resonance spectroscopy, and genetic analysis of the mutant indicated that galactoglucan, which is not produced under normal conditions by other R. meliloti strains, is produced by strain EFB1 and that production of this compound decreases when the organism is grown in the presence of salt. The mutant was found to be affected in a genetic region highly homologous to genes for galactoglucan production in R. meliloti Rm2011 (expE genes). However, sequence divergence occurs in a putative expE promoter region. A transcriptional fusion of the promoter with lacZ demonstrated that, unlike R. meliloti Rm2011, galactoglucan is produced constitutively by EFB1 and that its expression is reduced 10-fold during exponential growth in the presence of salt.
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Affiliation(s)
- J Lloret
- Departamento de Biología, Universidad Autónoma de Madrid, Spain
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Bonilla I, Mergold-Villaseñor C, Campos ME, Sánchez N, Pérez H, López L, Castrejón L, Sánchez F, Cassab GI. The aberrant cell walls of boron-deficient bean root nodules have no covalently bound hydroxyproline-/proline-rich proteins. Plant Physiol 1997; 115:1329-40. [PMID: 9414547 PMCID: PMC158598 DOI: 10.1104/pp.115.4.1329] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
B-deficient bean (Phaseolus vulgaris L.) nodules examined by light microscopy showed dramatic anatomical changes, mainly in the parenchyma region. Western analysis of total nodule extracts examined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that one 116-kD polypeptide was recognized by antibodies raised against hydroxyproline-rich glycoproteins (HRGPs) from the soybean (Glycine max) seed coat. A protein with a comparable molecular mass of 116 kD was purified from the cell walls of soybean root nodules. The amino acid composition of this protein is similar to the early nodulin (ENOD2) gene. Immunoprecipitation of the soybean ENOD2 in vitro translation product showed that the soybean seed coat anti-HRGP antibodies recognized this early nodulin. Furthermore, we used these antibodies to localize the ENOD2 homolog in bean nodules. Immunocytochemistry revealed that in B-deficient nodules ENOD2 was absent in the walls of the nodule parenchyma. The absence of ENOD2 in B-deficient nodules was corroborated by performing hydroxyproline assays. Northern analysis showed that ENOD2 mRNA is present in B-deficient nodules; therefore, the accumulation of ENOD2 is not affected by B deficiency, but its assembly into the cell wall is. B-deficient nodules fix much less N2 than control nodules, probably because the nodule parenchyma is no longer an effective O2 barrier.
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Affiliation(s)
- I Bonilla
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, Spain
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31
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Fernandez-Piñas F, Mateo P, Bonilla I. Effect of cadmium on the bioelement composition of Nostoc UAM208: interaction with calcium. Bull Environ Contam Toxicol 1997; 58:543-549. [PMID: 9060371 DOI: 10.1007/s001289900369] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Affiliation(s)
- F Fernandez-Piñas
- Departamento de Biologia, Facultad de Ciencias, Universidad Autonoma de Madrid, Spain
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32
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Monteseirín J, Prados M, Bonilla I, Llamas E, Delgado J, Sánchez-Monteseirín H, Chaparro A, Conde J. Granular proteins of eosinophils. Allergol Immunopathol (Madr) 1996; 24:219-25. [PMID: 8985478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- J Monteseirín
- Servicio Regional de Inmunología y Alergia, Hospital Universitario Virgen Macarena, Facultad de Medicina, Universidad de Sevilla, Spain
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33
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Monteseirín J, Prados M, Delgado J, Guardia P, de la Calle A, Bonilla I, Conde MA, Conde J. Eosinophil receptors. Allergol Immunopathol (Madr) 1996; 24:226-34. [PMID: 8985479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- J Monteseirín
- Servicio Regional de Inmunología y Alergia, Hospital Universitario, Virgen Macarena, Facultad de Medicina, Universidad de Sevilla, Spain
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34
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Monteseirín J, Camacho MJ, Gutiérrez D, Llamas E, Guardia P, Bonilla I, Sánchez-Monteseirín H, Conde J. Neutrophils and allergy. Allergol Immunopathol (Madr) 1996; 24:193-200. [PMID: 8985475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- J Monteseirín
- Servicio Regional de Inmunología y Alergia, Hospital Universitario Virgen Macarena, Facultad
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35
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Monteseirín J, de la Calle A, Delgado J, Guardia P, Bonilla I, Camacho MJ, Llamas E, Conde J. Antigen receptor signalling. Allergol Immunopathol (Madr) 1996; 24:185-92. [PMID: 8985474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- J Monteseirín
- Servicio Regional de Inmunología y Alergia, Hospital Universitario Virgen Macarena, Facultad de Medicina, Universidad de Sevilla, Spain
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36
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Bolanos L, Brewin NJ, Bonilla I. Effects of Boron on Rhizobium-Legume Cell-Surface Interactions and Nodule Development. Plant Physiol 1996; 110:1249-1256. [PMID: 12226256 PMCID: PMC160918 DOI: 10.1104/pp.110.4.1249] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Boron (B) is an essential micronutrient for the development of nitrogen-fixing root nodules in pea (Pisum sativum). By using monoclonal antibodies that recognize specific glycoconjugate components implicated in legume root-nodule development, we investigated the effects of low B on the formation of infection threads and the colonization of pea nodules by Rhizobium leguminosarum bv viciae. In B-deficient nodules the proportion of infected host cells was much lower than in nodules from plants supplied with normal quantities of B. Moreover, the host cells often developed enlarged and abnormally shaped infection threads that frequently burst, releasing bacteria into damaged host cells. There was also an over-production of plant matrix material in which the rhizobial cells were embedded during their progression through the infection thread. Furthermore, in a series of in vitro binding studies, we demonstrated that the presence of B can change the affinity with which the bacterial cell surface interacts with the peribacteroid membrane glycocalyx relative to its interaction with intercellular plant matrix glycoprotein. From these observations we suggest that B plays an important role in mediating cell-surface interactions that lead to endocytosis of rhizobia by host cells and hence to the correct establishment of the symbiosis between pea and Rhizobium.
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Affiliation(s)
- L. Bolanos
- Departamento de Biologia, Facultad de Ciencias, Universidad Autonoma de Madrid, 28049 Madrid, Spain (L.B., I.B.)
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Lloret J, Bolanos L, Lucas MM, Peart JM, Brewin NJ, Bonilla I, Rivilla R. Ionic Stress and Osmotic Pressure Induce Different Alterations in the Lipopolysaccharide of a Rhizobium meliloti Strain. Appl Environ Microbiol 1995; 61:3701-4. [PMID: 16535151 PMCID: PMC1388713 DOI: 10.1128/aem.61.10.3701-3704.1995] [Citation(s) in RCA: 78] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A halotolerant strain of Rhizobium meliloti was isolated from nodules of a Melilotus plant growing in a salt marsh in Donana National Park (southwest Spain). This strain, EFB1, is able to grow at NaCl concentrations of up to 500 mM, and no effect on growth is produced by 300 mM NaCl. EFB1 showed alterations on its lipopolysaccharide (LPS) structure that can be related to salt stress: (i) silver-stained electrophoretic profiles showed a different mobility that was dependent on ionic stress but not on osmotic pressure, and (ii) a monoclonal antibody, JIM 40, recognized changes in LPS that were dependent on osmotic stress. Both modifications on LPS may form part of the adaptive mechanism of this bacterium for saline environments.
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38
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Bolanos L, Esteban E, De Lorenzo C, Fernandez-Pascual M, De Felipe MR, Garate A, Bonilla I. Essentiality of Boron for Symbiotic Dinitrogen Fixation in Pea (Pisum sativum) Rhizobium Nodules. Plant Physiol 1994; 104:85-90. [PMID: 12232064 PMCID: PMC159165 DOI: 10.1104/pp.104.1.85] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The effect of boron deficiency on symbiotic nitrogen fixation in pea (Pisum sativum) was examined. The absence of boron in the culture medium resulted in a decrease of the number of nodules and an alteration of nodule development leading to an inhibition of nitrogenase activity. Examination of boron-deficient nodules showed dramatic changes in cell walls and in both peribacteroid and infection thread membranes, suggesting a role for boron in the stability of these structures. These results indicate that boron is a requirement for normal nodule development and functionality.
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Affiliation(s)
- L. Bolanos
- Departamento de Biologia (L.B., I.B.), and Departamento de Quimica Agricola (E.E., A.G.), Facultad de Ciencias, Universidad Autonoma de Madrid, 28049 Madrid, Spain
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Bonilla I, Garcia-González M, Mateo P. Boron requirement in cyanobacteria : its possible role in the early evolution of photosynthetic organisms. Plant Physiol 1990; 94:1554-60. [PMID: 16667889 PMCID: PMC1077420 DOI: 10.1104/pp.94.4.1554] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The effect of boron on heterocystous and nonheterocystous dinitrogen fixing Cyanobacteria was examined. The absence of boron in culture media inhibited growth and nitrogenase activity in Nodularia sp., Chlorogloeopsis sp., and Nostoc sp. cultures. Examinations of boron-deficient cultures showed changes in heterocyst morphology. However, cultures of nonheterocystous Cyanobacteria, Gloeothece sp. and Plectonema sp., grown in the absence of boron did not show any alteration in growth or nitrogenase activity. These results suggest a requirement of boron only by heterocystous Cyanobacteria. A possible role for this element in the early evolution of photosynthetic organisms is proposed.
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Affiliation(s)
- I Bonilla
- Departmento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, 28049 Madrid, Spain
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40
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Garcia-González M, Mateo P, Bonilla I. Effect of Boron Deficiency on Photosynthesis and Reductant Sources and Their Relationship with Nitrogenase Activity in Anabaena PCC 7119. Plant Physiol 1990; 93:560-5. [PMID: 16667503 PMCID: PMC1062550 DOI: 10.1104/pp.93.2.560] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Nitrogenase activity of Anabaena PCC 7119 is inhibited under conditions of boron deficiency. To elucidate the mechanisms of this inhibition, this study examined how the deficiency of boron affected photosynthesis, photosynthetic pigments, the enzymes of the oxidative pentose phosphate pathway, and respiration of Anabaena PCC 7119 cultures. After 24 to 48 hours of boron deficiency, reductions in photosynthetic O(2) evolution and in CO(2) fixation were observed. At the same time, the activities of oxidative pentose phosphate pathway enzymes and respiration increased significantly with boron deficiency. No change was observed in these processes when assays were performed after 4 to 6 hours of deficiency, a time at which nitrogenase activity was severely inhibited. These results suggest that the requirement for boron in N(2) fixation is independent of its effects on photosynthesis and reductant supply.
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Affiliation(s)
- M Garcia-González
- Departamento de Biologia, Facultad de Ciencias, Universidad Autónoma de Madrid, 28049 Madrid, Spain
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41
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Bernal E, Bonilla I. [Social scientific problems of anticholera vaccination in Seville (1885): the reports of Rafael Tuñón and Leopoldo Murga]. Dynamis 1989; 9:167-184. [PMID: 11622247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Abstract
The effect of boron on nitrogenase activity has been studied. When cells were dependent on N(2) fixation, the lack of boron inhibited nitrogenase activity. However, under anaerobic conditions or in the presence of Na-dithionite this effect was not observed. Nitrogenase synthesis was not affected by boron deficiency. Similarly, the heterocyst number was not altered. Examination of boron-deficient cultures showed, however, some dramatic changes in heterocyst morphology. The increased activity of those enzymes related to the maintaining of the low intracellular level of toxic oxygen species (superoxide dismutase, catalase, and peroxidase) support our hypothesis of the role of boron in heterocyst envelope stabilization.
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Affiliation(s)
- M Garcia-González
- Departamento de Biologia, Facultad de Ciencias, Universidad Autónoma de Madrid, 28049 Madrid, Spain
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Mateo P, Bonilla I, Fernández-Valiente E, Sanchez-Maeso E. Essentiality of Boron for Dinitrogen Fixation in Anabaena sp. PCC 7119. Plant Physiol 1986; 81:430-3. [PMID: 16664833 PMCID: PMC1075352 DOI: 10.1104/pp.81.2.430] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The relationship between the requirement for boron and the form of N supplied in nutrient media to cyanobacterium Anabaena sp. PCC 7119 was investigated. When cells were grown in a medium which contained nitrate or ammonium-N, boron deficiency in the nutrient media did not inhibit growth or change cell composition. However, when cells were dependent on N(2) fixation, the lack of boron inhibited growth (i.e. growth ceased after 96 hours under these conditions). Additionally, boron-deficient cells showed a significant decrease in their content of phycobiliproteins and chlorophyll and accumulated carbohydrates within 24 hours of removing boron from the nutrient media. Inhibition of photosynthetic O(2) evolution accompanied the decrease in photosynthetic pigments. Boron deficiency symptoms were relieved when either boron or combined N was added to boron-deficient cultures. The degree of recovery depended upon the age of the cultures. Assays of nitrogenase activity showed that, after 2 hours of growth, nitrogenase activity of boron-deficient cells was inhibited by 40%. After 24 hours a total inactivation of nitrogenase activity was observed in boron-deficient cells. These results strongly suggest an involvement of boron in N(2) fixation in cyanobacteria.
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Affiliation(s)
- P Mateo
- Departamento de Biología General, Facultad de Ciencias, Universidad Autónoma de Madrid, 28049 Madrid, Spain
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Ortí T, Martín A, Palafox E, Bonilla I. [Urinary infection by Corynebacterium species: presentation of 8 cases]. Med Clin (Barc) 1985; 85:266-8. [PMID: 4058081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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45
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Otte A, Bonilla I, Gil C, Bolinches R, Andreu L, Canós I. [A rare case of silent cholinesterase genetic variant (author's transl)]. Med Clin (Barc) 1980; 75:309-11. [PMID: 7432039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Some patients present prolonged apnea following the administration of succinylcholine because of substantial portion of plasma cholinesterase (the enzyme responsible for the hydrolysis of this muscle relaxant) is present as an atypical variant. Up to the present four types of cholinesterase genes are known which combination can cause apnea to a greater or less extent. Silent homozygous EsEs present apnea of greatest duration due to the complete absence of cholinesterase activity. The case reported belongs to a family of four members and is an example of this extremely uncommon genetic variant, with a frequency of 1/170.000. To determine total cholinesterase activity genetic typing of the whole family was carried out utilizing the spectrophotometric technique of Szasz and Knedel with butirylthiocholine iodide as substrate. Inhibition studies were performed using benzoylcholine and dibucaine, sodium fluoride, scholine, and sodium chloride as inhibitors.
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