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Premont RT, Reynolds JD, Zhang R, Stamler JS. Red Blood Cell-Mediated S-Nitrosohemoglobin-Dependent Vasodilation: Lessons Learned from a β-Globin Cys93 Knock-In Mouse. Antioxid Redox Signal 2021; 34:936-961. [PMID: 32597195 PMCID: PMC8035927 DOI: 10.1089/ars.2020.8153] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 06/25/2020] [Indexed: 12/25/2022]
Abstract
Significance: Red blood cell (RBC)-mediated vasodilation plays an important role in oxygen delivery. This occurs through hemoglobin actions, at least in significant part, to convert heme-bound nitric oxide (NO) (in tense [T]/deoxygenated-state hemoglobin) into vasodilator S-nitrosothiol (SNO) (in relaxed [R]/oxygenated-state hemoglobin), convey SNO through the bloodstream, and release it into tissues to increase blood flow. The coupling of hemoglobin R/T state allostery, both to NO conversion into SNO and to SNO release (along with oxygen), under hypoxia supports the model of a three-gas respiratory cycle (O2/NO/CO2). Recent Advances: Oxygenation of tissues is dependent on a single, strictly conserved Cys residue in hemoglobin (βCys93). Hemoglobin couples SNO formation/release at βCys93 to O2 binding/release at hemes ("thermodynamic linkage"). Mice bearing βCys93Ala hemoglobin that is unable to generate SNO-βCys93 establish that SNO-hemoglobin is important for R/T allostery-regulated vasodilation by RBCs that couple blood flow to tissue oxygenation. Critical Issues: The model for RBC-mediated vasodilation originally proposed by Stamler et al. in 1996 has been largely validated: SNO-βCys93 forms in vivo, dilates blood vessels, and is hypoxia-regulated, and RBCs actuate vasodilation proportionate to hypoxia. Numerous compensations in βCys93Ala animals to alleviate tissue hypoxia (discussed herein) are predicted to preserve vasodilatory responses of RBCs but impair linkage to R/T transition in hemoglobin. This is borne out by loss of responsivity of mutant RBCs to oxygen, impaired blood flow responses to hypoxia, and tissue ischemia in βCys93-mutant animals. Future Directions: SNO-hemoglobin mediates hypoxic vasodilation in the respiratory cycle. This fundamental physiology promises new insights in vascular diseases and blood disorders.
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Affiliation(s)
- Richard T. Premont
- Institute for Transformative Molecular Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
- Harrington Discovery Institute, University Hospitals Cleveland Medical Center, Cleveland, Ohio, USA
| | - James D. Reynolds
- Institute for Transformative Molecular Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
- Harrington Discovery Institute, University Hospitals Cleveland Medical Center, Cleveland, Ohio, USA
- Department of Anesthesiology and Perioperative Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
| | - Rongli Zhang
- Institute for Transformative Molecular Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
- Department of Medicine, Cardiovascular Research Institute, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
| | - Jonathan S. Stamler
- Institute for Transformative Molecular Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
- Harrington Discovery Institute, University Hospitals Cleveland Medical Center, Cleveland, Ohio, USA
- Department of Medicine, Cardiovascular Research Institute, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
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Premont RT, Stamler JS. Essential Role of Hemoglobin βCys93 in Cardiovascular Physiology. Physiology (Bethesda) 2020; 35:234-243. [PMID: 32490751 PMCID: PMC7474257 DOI: 10.1152/physiol.00040.2019] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Revised: 02/12/2020] [Accepted: 02/13/2020] [Indexed: 12/21/2022] Open
Abstract
The supply of oxygen to tissues is controlled by microcirculatory blood flow. One of the more surprising discoveries in cardiovascular physiology is the critical dependence of microcirculatory blood flow on a single conserved cysteine within the β-subunit (βCys93) of hemoglobin (Hb). βCys93 is the primary site of Hb S-nitrosylation [i.e., S-nitrosothiol (SNO) formation to produce S-nitrosohemoglobin (SNO-Hb)]. Notably, S-nitrosylation of βCys93 by NO is favored in the oxygenated conformation of Hb, and deoxygenated Hb releases SNO from βCys93. Since SNOs are vasodilatory, this mechanism provides a physiological basis for how tissue hypoxia increases microcirculatory blood flow (hypoxic autoregulation of blood flow). Mice expressing βCys93A mutant Hb (C93A) have been applied to understand the role of βCys93, and RBCs more generally, in cardiovascular physiology. Notably, C93A mice are unable to effect hypoxic autoregulation of blood flow and exhibit widespread tissue hypoxia. Moreover, reactive hyperemia (augmentation of blood flow following transient ischemia) is markedly impaired. C93A mice display multiple compensations to preserve RBC vasodilation and overcome tissue hypoxia, including shifting SNOs to other thiols on adult and fetal Hbs and elsewhere in RBCs, and growing new blood vessels. However, compensatory vasodilation in C93A mice is uncoupled from hypoxic control, both peripherally (e.g., predisposing to ischemic injury) and centrally (e.g., impairing hypoxic drive to breathe). Altogether, physiological studies utilizing C93A mice are confirming the allosterically controlled role of SNO-Hb in microvascular blood flow, uncovering essential roles for RBC-mediated vasodilation in cardiovascular physiology and revealing new roles for RBCs in cardiovascular disease.
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Affiliation(s)
- Richard T Premont
- Institute for Transformative Molecular Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio
- Harrington Discovery Institute, University Hospitals Cleveland Medical Center, Cleveland, Ohio
| | - Jonathan S Stamler
- Institute for Transformative Molecular Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio
- Harrington Discovery Institute, University Hospitals Cleveland Medical Center, Cleveland, Ohio
- Department of Medicine, University Hospitals Cleveland Medical Center, Case Western Reserve University School of Medicine, Cleveland, Ohio
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Zhou S, Giannetto M, DeCourcey J, Kang H, Kang N, Li Y, Zheng S, Zhao H, Simmons WR, Wei HS, Bodine DM, Low PS, Nedergaard M, Wan J. Oxygen tension-mediated erythrocyte membrane interactions regulate cerebral capillary hyperemia. SCIENCE ADVANCES 2019; 5:eaaw4466. [PMID: 31149638 PMCID: PMC6541463 DOI: 10.1126/sciadv.aaw4466] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 04/17/2019] [Indexed: 05/24/2023]
Abstract
The tight coupling between cerebral blood flow and neural activity is a key feature of normal brain function and forms the basis of functional hyperemia. The mechanisms coupling neural activity to vascular responses, however, remain elusive despite decades of research. Recent studies have shown that cerebral functional hyperemia begins in capillaries, and red blood cells (RBCs) act as autonomous regulators of brain capillary perfusion. RBCs then respond to local changes of oxygen tension (PO2) and regulate their capillary velocity. Using ex vivo microfluidics and in vivo two-photon microscopy, we examined RBC capillary velocity as a function of PO2 and showed that deoxygenated hemoglobin and band 3 interactions on RBC membrane are the molecular switch that responds to local PO2 changes and controls RBC capillary velocity. Capillary hyperemia can be controlled by manipulating RBC properties independent of the neurovascular unit, providing an effective strategy to treat or prevent impaired functional hyperemia.
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Affiliation(s)
- Sitong Zhou
- Microsystems Engineering, Rochester Institute of Technology, Rochester, NY 14623, USA
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Michael Giannetto
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - James DeCourcey
- College of Osteopathic Medicine, University of New England, Biddeford, ME 04005, USA
| | - Hongyi Kang
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Ning Kang
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Yizeng Li
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Suilan Zheng
- Department of Chemistry, Purdue University, West Lafayette, IN 47907, USA
| | - Hetince Zhao
- New York University Langone Medical Center, New York, NY 10010, USA
| | | | - Helen S. Wei
- Rutgers New Jersey Medical School, Newark, NJ 07101, USA
| | - David M. Bodine
- National Human Genome Research Institute, Bethesda, MD 20894, USA
| | - Philip S. Low
- Department of Chemistry, Purdue University, West Lafayette, IN 47907, USA
| | - Maiken Nedergaard
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Jiandi Wan
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY 14642, USA
- Department of Chemical Engineering, University of California, Davis, Davis, CA 95616, USA
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Hirsch RE, Sibmooh N, Fucharoen S, Friedman JM. HbE/β-Thalassemia and Oxidative Stress: The Key to Pathophysiological Mechanisms and Novel Therapeutics. Antioxid Redox Signal 2017; 26:794-813. [PMID: 27650096 PMCID: PMC5421591 DOI: 10.1089/ars.2016.6806] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 09/16/2016] [Indexed: 01/19/2023]
Abstract
SIGNIFICANCE Oxidative stress and generation of free radicals are fundamental in initiating pathophysiological mechanisms leading to an inflammatory cascade resulting in high rates of morbidity and death from many inherited point mutation-derived hemoglobinopathies. Hemoglobin (Hb)E is the most common point mutation worldwide. The βE-globin gene is found in greatest frequency in Southeast Asia, including Thailand, Malaysia, Indonesia, Vietnam, Cambodia, and Laos. With the wave of worldwide migration, it is entering the gene pool of diverse populations with greater consequences than expected. CRITICAL ISSUES While HbE by itself presents as a mild anemia and a single gene for β-thalassemia is not serious, it remains unexplained why HbE/β-thalassemia (HbE/β-thal) is a grave disease with high morbidity and mortality. Patients often exhibit defective physical development, severe chronic anemia, and often die of cardiovascular disease and severe infections. Recent Advances: This article presents an overview of HbE/β-thal disease with an emphasis on new findings pointing to pathophysiological mechanisms derived from and initiated by the dysfunctional property of HbE as a reduced nitrite reductase concomitant with excess α-chains exacerbating unstable HbE, leading to a combination of nitric oxide imbalance, oxidative stress, and proinflammatory events. FUTURE DIRECTIONS Additionally, we present new therapeutic strategies that are based on the emerging molecular-level understanding of the pathophysiology of this and other hemoglobinopathies. These strategies are designed to short-circuit the inflammatory cascade leading to devastating chronic morbidity and fatal consequences. Antioxid. Redox Signal. 26, 794-813.
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Affiliation(s)
- Rhoda Elison Hirsch
- Department of Medicine (Hematology), Albert Einstein College of Medicine, Bronx, New York
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, New York
| | - Nathawut Sibmooh
- Department of Pharmacology, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Suthat Fucharoen
- Thalassemia Research Center, Institute of Molecular Biosciences, Mahidol University, Nakornpathom, Thailand
| | - Joel M. Friedman
- Department of Physiology and Biophysics, Albert Einstein College of Medicine, Bronx, New York
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Revin VV, Gromova NV, Revina ES, Martynova MI, Seikina AI, Revina NV, Imarova OG, Solomadin IN, Tychkov AY, Zhelev N. Role of Membrane Lipids in the Regulation of Erythrocytic Oxygen-Transport Function in Cardiovascular Diseases. BIOMED RESEARCH INTERNATIONAL 2016; 2016:3429604. [PMID: 27872848 PMCID: PMC5107249 DOI: 10.1155/2016/3429604] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 09/05/2016] [Accepted: 10/04/2016] [Indexed: 01/11/2023]
Abstract
The composition and condition of membrane lipids, the morphology of erythrocytes, and hemoglobin distribution were explored with the help of laser interference microscopy (LIM) and Raman spectroscopy. It is shown that patients with cardiovascular diseases (CVD) have significant changes in the composition of their phospholipids and the fatty acids of membrane lipids. Furthermore, the microviscosity of the membranes and morphology of the erythrocytes are altered causing disordered oxygen transport by hemoglobin. Basic therapy carried out with the use of antiaggregants, statins, antianginals, beta-blockers, and calcium antagonists does not help to recover the morphofunctional properties of erythrocytes. Based on the results the authors assume that, for the relief of the ischemic crisis and further therapeutic treatment, it is necessary to include, in addition to cardiovascular disease medicines, medication that increases the ability of erythrocytes' hemoglobin to transport oxygen to the tissues. We assume that the use of LIM and Raman spectroscopy is advisable for early diagnosis of changes in the structure and functional state of erythrocytes when cardiovascular diseases develop.
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Affiliation(s)
- Victor V. Revin
- Federal State-Financed Academic Institution of Higher Education “National Research Ogarev Mordovia State University”, Saransk 430005, Russia
| | - Natalia V. Gromova
- Federal State-Financed Academic Institution of Higher Education “National Research Ogarev Mordovia State University”, Saransk 430005, Russia
| | - Elvira S. Revina
- Federal State-Financed Academic Institution of Higher Education “National Research Ogarev Mordovia State University”, Saransk 430005, Russia
| | - Maria I. Martynova
- Federal State-Financed Academic Institution of Higher Education “National Research Ogarev Mordovia State University”, Saransk 430005, Russia
| | - Angelina I. Seikina
- Federal State-Financed Academic Institution of Higher Education “National Research Ogarev Mordovia State University”, Saransk 430005, Russia
| | - Nadezhda V. Revina
- Federal State-Financed Academic Institution of Higher Education “National Research Ogarev Mordovia State University”, Saransk 430005, Russia
| | - Oksana G. Imarova
- GBUZ RM “National Hospital for War Veterans”, Saransk 430005, Russia
| | - Ilia N. Solomadin
- Federal State-Financed Academic Institution of Higher Education “National Research Ogarev Mordovia State University”, Saransk 430005, Russia
| | - Alexander Yu. Tychkov
- Federal State-Financed Academic Institution of Higher Education “National Research Ogarev Mordovia State University”, Saransk 430005, Russia
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Chen Q, Fabry ME, Rybicki AC, Suzuka SM, Balazs TC, Etzion Z, de Jong K, Akoto EK, Canterino JE, Kaul DK, Kuypers FA, Lefer D, Bouhassira EE, Hirsch RE. A transgenic mouse model expressing exclusively human hemoglobin E: indications of a mild oxidative stress. Blood Cells Mol Dis 2012; 48:91-101. [PMID: 22260787 PMCID: PMC3310900 DOI: 10.1016/j.bcmd.2011.12.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2011] [Revised: 11/04/2011] [Accepted: 11/22/2011] [Indexed: 11/19/2022]
Abstract
Hemoglobin (Hb) E (β26 Glu→Lys) is the most common abnormal hemoglobin (Hb) variant in the world. Homozygotes for HbE are mildly thalassemic as a result of the alternate splice mutation and present with a benign clinical picture (microcytic and mildly anemic) with rare clinical symptoms. Given that the human red blood cell (RBC) contains both HbE and excess α-chains along with minor hemoglobins, the consequence of HbE alone on RBC pathophysiology has not been elucidated. This becomes critical for the highly morbid β(E)-thalassemia disease. We have generated transgenic mice exclusively expressing human HbE (HbEKO) that exhibit the known aberrant splicing of β(E) globin mRNA, but are essentially non-thalassemic as demonstrated by RBC α/β (human) globin chain synthesis. These mice exhibit hematological characteristics similar to presentations in human EE individuals: microcytic RBC with low MCV and MCH but normal MCHC; target RBC; mild anemia with low Hb, HCT and mildly elevated reticulocyte levels and decreased osmotic fragility, indicating altered RBC surface area to volume ratio. These alterations are correlated with a mild RBC oxidative stress indicated by enhanced membrane lipid peroxidation, elevated zinc protoporphyrin levels, and by small but significant changes in cardiac function. The C57 (background) mouse and full KO mouse models expressing HbE with the presence of HbS or HbA are used as controls. In select cases, the HbA full KO mouse model is compared but found to be limited due to its RBC thalassemic characteristics. Since the HbEKO mouse RBC lacks an abundance of excess α-chains that would approximate a mouse thalassemia (or a human thalassemia), the results indicate that the observed in vivo RBC mild oxidative stress arises, at least in part, from the molecular consequences of the HbE mutation.
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Affiliation(s)
- Qiuying Chen
- Department of Medicine/Hematology, Albert Einstein College of Medicine, Bronx, NY
| | - Mary E. Fabry
- Department of Medicine/Hematology, Albert Einstein College of Medicine, Bronx, NY
| | - Anne C. Rybicki
- Department of Medicine/Hematology, Albert Einstein College of Medicine, Bronx, NY
- Montefiore Medical Center, Bronx, NY
| | - Sandra M. Suzuka
- Department of Medicine/Hematology, Albert Einstein College of Medicine, Bronx, NY
| | - Tatiana C. Balazs
- Department of Medicine/Hematology, Albert Einstein College of Medicine, Bronx, NY
| | - Zipora Etzion
- Department of Medicine/Hematology, Albert Einstein College of Medicine, Bronx, NY
| | - Kitty de Jong
- Children’s Hospital of Oakland, Research Institute, CA
| | - Edna K. Akoto
- Department of Medicine/Hematology, Albert Einstein College of Medicine, Bronx, NY
| | - Joseph E. Canterino
- Department of Medicine/Hematology, Albert Einstein College of Medicine, Bronx, NY
| | - Dhananjay K. Kaul
- Department of Medicine/Hematology, Albert Einstein College of Medicine, Bronx, NY
| | | | - David Lefer
- Department of Surgery, Emory University School of Medicine, Atlanta, Ga
| | - Eric E. Bouhassira
- Department of Medicine/Hematology, Albert Einstein College of Medicine, Bronx, NY
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY
| | - Rhoda Elison Hirsch
- Department of Medicine/Hematology, Albert Einstein College of Medicine, Bronx, NY
- Department of Anatomy & Structural Biology, Albert Einstein College of Medicine, Bronx, NY
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7
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Semenova AA, Goodilin EA, Brazhe NA, Ivanov VK, Baranchikov AE, Lebedev VA, Goldt AE, Sosnovtseva OV, Savilov SV, Egorov AV, Brazhe AR, Parshina EY, Luneva OG, Maksimov GV, Tretyakov YD. Planar SERS nanostructures with stochastic silver ring morphology for biosensor chips. ACTA ACUST UNITED AC 2012. [DOI: 10.1039/c2jm34686a] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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8
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Roche CJ, Malashkevich V, Balazs TC, Dantsker D, Chen Q, Moreira J, Almo SC, Friedman JM, Hirsch RE. Structural and functional studies indicating altered redox properties of hemoglobin E: implications for production of bioactive nitric oxide. J Biol Chem 2011; 286:23452-66. [PMID: 21531715 PMCID: PMC3123109 DOI: 10.1074/jbc.m110.183186] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2010] [Revised: 04/28/2011] [Indexed: 12/22/2022] Open
Abstract
Hemoglobin (Hb) E (β-Glu26Lys) remains an enigma in terms of its contributions to red blood cell (RBC) pathophysiological mechanisms; for example, EE individuals exhibit a mild chronic anemia, and HbE/β-thalassemia individuals show a range of clinical manifestations, including high morbidity and death, often resulting from cardiac dysfunction. The purpose of this study was to determine and evaluate structural and functional consequences of the HbE mutation that might account for the pathophysiology. Functional studies indicate minimal allosteric consequence to both oxygen and carbon monoxide binding properties of the ferrous derivatives of HbE. In contrast, redox-sensitive reactions are clearly impacted as seen in the following: 1) the ∼2.5 times decrease in the rate at which HbE catalyzes nitrite reduction to nitric oxide (NO) relative to HbA, and 2) the accelerated rate of reduction of aquometHbE by L-cysteine (L-Cys). Sol-gel encapsulation studies imply a shift toward a higher redox potential for both the T and R HbE structures that can explain the origin of the reduced nitrite reductase activity of deoxyHbE and the accelerated rate of reduction of aquometHbE by cysteine. Deoxy- and CO HbE crystal structures (derived from crystals grown at or near physiological pH) show loss of hydrogen bonds in the microenvironment of βLys-26 and no significant tertiary conformational perturbations at the allosteric transition sites in the R and T states. Together, these data suggest a model in which the HbE mutation, as a consequence of a relative change in redox properties, decreases the overall rate of Hb-mediated production of bioactive NO.
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Affiliation(s)
| | | | | | | | | | - Juan Moreira
- From the Departments of Physiology and Biophysics
| | | | | | - Rhoda Elison Hirsch
- Medicine (Division of Hematology), and
- Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, New York 10461
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9
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Brazhe NA, Abdali S, Brazhe AR, Luneva OG, Bryzgalova NY, Parshina EY, Sosnovtseva OV, Maksimov GV. New insight into erythrocyte through in vivo surface-enhanced Raman spectroscopy. Biophys J 2010; 97:3206-14. [PMID: 20006958 DOI: 10.1016/j.bpj.2009.09.029] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2009] [Revised: 09/11/2009] [Accepted: 09/15/2009] [Indexed: 11/26/2022] Open
Abstract
The article presents a noninvasive approach to the study of erythrocyte properties by means of a comparative analysis of signals obtained by surface-enhanced Raman spectroscopy (SERS) and resonance Raman spectroscopy (RS). We report step-by-step the procedure for preparing experimental samples containing erythrocytes in their normal physiological environment in a mixture of colloid solution with silver nanoparticles and the procedure for the optimization of SERS conditions to achieve high signal enhancement without affecting the properties of living erythrocytes. By means of three independent techniques, we demonstrate that under the proposed conditions a colloid solution of silver nanoparticles does not affect the properties of erythrocytes. For the first time to our knowledge, we describe how to use the SERS-RS approach to study two populations of hemoglobin molecules inside an intact living erythrocyte: submembrane and cytosolic hemoglobin (Hb(sm) and Hb(c)). We show that the conformation of Hb(sm) differs from the conformation of Hb(c). This finding has an important application, as the comparative study of Hb(sm) and Hb(c) could be successfully used in biomedical research and diagnostic tests.
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Affiliation(s)
- Nadezda A Brazhe
- Biophysics Department, Biological Faculty, Moscow State University, Moscow, Russian Federation.
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10
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Canterino JE, Galkin O, Vekilov PG, Hirsch RE. Phase separation and crystallization of hemoglobin C in transgenic mouse and human erythrocytes. Biophys J 2008; 95:4025-33. [PMID: 18621841 PMCID: PMC2553125 DOI: 10.1529/biophysj.107.127324] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2007] [Accepted: 06/13/2008] [Indexed: 11/18/2022] Open
Abstract
Individuals expressing hemoglobin C (beta6 Glu-->Lys) present red blood cells (RBC) with intraerythrocytic crystals that form when hemoglobin (Hb) is oxygenated. Our earlier in vitro liquid-liquid (L-L) phase separation studies demonstrated that liganded HbC exhibits a stronger net intermolecular attraction with a longer range than liganded HbS or HbA, and that L-L phase separation preceded and enhanced crystallization. We now present evidence for the role of phase separation in HbC crystallization in the RBC, and the role of the RBC membrane as a nucleation center. RBC obtained from both human homozygous HbC patients and transgenic mice expressing only human HbC were studied by bright-field and differential interference contrast video-enhanced microscopy. RBC were exposed to hypertonic NaCl solution (1.5-3%) to induce crystallization within an appropriate experimental time frame. L-L phase separation occurred inside the RBC, which in turn enhanced the formation of intraerythrocytic crystals. RBC L-L phase separation and crystallization comply with the thermodynamic and kinetics laws established through in vitro studies of phase transformations. This is the first report, to the best of our knowledge, to capture a temporal view of intraerythrocytic HbC phase separation, crystal formation, and dissolution.
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Affiliation(s)
- Joseph E Canterino
- Department of Medicine and Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, New York, USA
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