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Porto E, Loula P, Strand S, Hankeln T. Molecular analysis of the human cytoglobin mRNA isoforms. J Inorg Biochem 2024; 251:112422. [PMID: 38016326 DOI: 10.1016/j.jinorgbio.2023.112422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 09/26/2023] [Accepted: 10/29/2023] [Indexed: 11/30/2023]
Abstract
Multiple functions have been proposed for the ubiquitously expressed vertebrate globin cytoglobin (Cygb), including nitric oxide (NO) metabolism, lipid peroxidation/signalling, superoxide dismutase activity, reactive oxygen/nitrogen species (RONS) scavenging, regulation of blood pressure, antifibrosis, and both tumour suppressor and oncogenic effects. Since alternative splicing can expand the biological roles of a gene, we investigated whether this mechanism contributes to the functional diversity of Cygb. By mining of cDNA data and molecular analysis, we identified five alternative mRNA isoforms for the human CYGB gene (V-1 to V-5). Comprehensive RNA-seq analyses of public datasets from human tissues and cells confirmed that the canonical CYGB V-1 isoform is the primary CYGB transcript in the majority of analysed datasets. Interestingly, we revealed that isoform V-3 represented the predominant CYGB variant in hepatoblastoma (HB) cell lines and in the majority of analysed normal and HB liver tissues. CYGB V-3 mRNA is transcribed from an alternate upstream promoter and hypothetically encodes a N-terminally truncated CYGB protein, which is not recognized by some antibodies used in published studies. Little to no transcriptional evidence was found for the other CYGB isoforms. Comparative transcriptomics and flow cytometry on CYGB+/+ and gene-edited CYGB-/- HepG2 HB cells did not unveil a knockout phenotype and, thus, a potential function for CYGB V-3. Our study reveals that the CYGB gene is transcriptionally more complex than previously described as it expresses alternative mRNA isoforms of unknown function. Additional experimental data are needed to clarify the biological meaning of those alternative CYGB transcripts.
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Affiliation(s)
- Elena Porto
- Institute of Organismic and Molecular Evolution, Molecular Genetics & Genome Analysis Group, Johannes Gutenberg University Mainz, J. J. Becher-Weg 30A, D-55128 Mainz, Germany
| | - Paraskevi Loula
- Institute of Organismic and Molecular Evolution, Molecular Genetics & Genome Analysis Group, Johannes Gutenberg University Mainz, J. J. Becher-Weg 30A, D-55128 Mainz, Germany
| | - Susanne Strand
- Department of Internal Medicine I, Molecular Hepatology, University Medical Center, Johannes Gutenberg University Mainz, Obere Zahlbacher Strasse 63, 55131 Mainz, Germany
| | - Thomas Hankeln
- Institute of Organismic and Molecular Evolution, Molecular Genetics & Genome Analysis Group, Johannes Gutenberg University Mainz, J. J. Becher-Weg 30A, D-55128 Mainz, Germany.
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2
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Porto E, De Backer J, Thuy LTT, Kawada N, Hankeln T. Transcriptomics of a cytoglobin knockout mouse: Insights from hepatic stellate cells and brain. J Inorg Biochem 2024; 250:112405. [PMID: 37977965 DOI: 10.1016/j.jinorgbio.2023.112405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 10/10/2023] [Accepted: 10/16/2023] [Indexed: 11/19/2023]
Abstract
The vertebrate respiratory protein cytoglobin (Cygb) is thought to exert multiple cellular functions. Here we studied the phenotypic effects of a Cygb knockout (KO) in mouse on the transcriptome level. RNA sequencing (RNA-Seq) was performed for the first time on sites of major endogenous Cygb expression, i.e. quiescent and activated hepatic stellate cells (HSCs) and two brain regions, hippocampus and hypothalamus. The data recapitulated the up-regulation of Cygb during HSC activation and its expression in the brain. Differential gene expression analyses suggested a role of Cygb in the response to inflammation in HSCs and its involvement in retinoid metabolism, retinoid X receptor (RXR) activation-induced xenobiotics metabolism, and RXR activation-induced lipid metabolism and signaling in activated cells. Unexpectedly, only minor effects of the Cygb KO were detected in the transcriptional profiles in hippocampus and hypothalamus, precluding any enrichment analyses. Furthermore, the transcriptome data pointed at a previously undescribed potential of the Cygb- knockout allele to produce cis-acting effects, necessitating future verification studies.
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Affiliation(s)
- Elena Porto
- Institute of Organismic and Molecular Evolution, Molecular Genetics & Genome Analysis Group, Johannes Gutenberg University Mainz, J. J. Becher-Weg 30A, Mainz D-55128, Germany
| | - Joey De Backer
- Research Group PPES, Department of Biomedical Sciences, University of Antwerp, Universiteitsplein 1, Wilrijk, Antwerp 1610, Belgium
| | - Le Thi Thanh Thuy
- Department of Hepatology, Graduate School of Medicine, Osaka Metropolitan University, Osaka 545-8585, Japan
| | - Norifumi Kawada
- Department of Hepatology, Graduate School of Medicine, Osaka Metropolitan University, Osaka 545-8585, Japan
| | - Thomas Hankeln
- Institute of Organismic and Molecular Evolution, Molecular Genetics & Genome Analysis Group, Johannes Gutenberg University Mainz, J. J. Becher-Weg 30A, Mainz D-55128, Germany.
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3
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Rochon ER, Xue J, Mohammed MS, Smith C, Hay-Schmidt A, DeMartino AW, Clark A, Xu Q, Lo CW, Tsang M, Tejero J, Gladwin MT, Corti P. Cytoglobin regulates NO-dependent cilia motility and organ laterality during development. Nat Commun 2023; 14:8333. [PMID: 38097556 PMCID: PMC10721929 DOI: 10.1038/s41467-023-43544-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Accepted: 11/10/2023] [Indexed: 12/17/2023] Open
Abstract
Cytoglobin is a heme protein with unresolved physiological function. Genetic deletion of zebrafish cytoglobin (cygb2) causes developmental defects in left-right cardiac determination, which in humans is associated with defects in ciliary function and low airway epithelial nitric oxide production. Here we show that Cygb2 co-localizes with cilia and with the nitric oxide synthase Nos2b in the zebrafish Kupffer's vesicle, and that cilia structure and function are disrupted in cygb2 mutants. Abnormal ciliary function and organ laterality defects are phenocopied by depletion of nos2b and of gucy1a, the soluble guanylate cyclase homolog in fish. The defects are rescued by exposing cygb2 mutant embryos to a nitric oxide donor or a soluble guanylate cyclase stimulator, or with over-expression of nos2b. Cytoglobin knockout mice also show impaired airway epithelial cilia structure and reduced nitric oxide levels. Altogether, our data suggest that cytoglobin is a positive regulator of a signaling axis composed of nitric oxide synthase-soluble guanylate cyclase-cyclic GMP that is necessary for normal cilia motility and left-right patterning.
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Affiliation(s)
- Elizabeth R Rochon
- Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Jianmin Xue
- Pittsburgh Heart, Lung, and Blood Vascular Medicine Institute, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA
| | - Manush Sayd Mohammed
- Department of Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15260, USA
| | - Caroline Smith
- Pittsburgh Heart, Lung, and Blood Vascular Medicine Institute, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA
| | - Anders Hay-Schmidt
- Department of Odontology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Anthony W DeMartino
- Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Adam Clark
- Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Qinzi Xu
- Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Cecilia W Lo
- Department of Developmental Biology, Rangos Research Center, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15201, USA
| | - Michael Tsang
- Department of Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15260, USA
| | - Jesus Tejero
- Pittsburgh Heart, Lung, and Blood Vascular Medicine Institute, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA
- Division of Pulmonary, Allergy and Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15261, USA
- Department of Bioengineering, University of Pittsburgh Swanson School of Engineering, Pittsburgh, PA, 15260, USA
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, 15261, USA
| | - Mark T Gladwin
- Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, 21201, USA.
| | - Paola Corti
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA.
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4
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Reeder BJ. Insights into the function of cytoglobin. Biochem Soc Trans 2023; 51:1907-1919. [PMID: 37721133 PMCID: PMC10657185 DOI: 10.1042/bst20230081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 09/11/2023] [Accepted: 09/12/2023] [Indexed: 09/19/2023]
Abstract
Since its discovery in 2001, the function of cytoglobin has remained elusive. Through extensive in vitro and in vivo research, a range of potential physiological and pathological mechanisms has emerged for this multifunctional member of the hemoglobin family. Currently, over 200 research publications have examined different aspects of cytoglobin structure, redox chemistry and potential roles in cell signalling pathways. This research is wide ranging, but common themes have emerged throughout the research. This review examines the current structural, biochemical and in vivo knowledge of cytoglobin published over the past two decades. Radical scavenging, nitric oxide homeostasis, lipid binding and oxidation and the role of an intramolecular disulfide bond on the redox chemistry are examined, together with aspects and roles for Cygb in cancer progression and liver fibrosis.
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Affiliation(s)
- Brandon J Reeder
- School of Life Sciences, University of Essex, Wivenhoe Park, Colchester, Essex, U.K
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5
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Mathai C, Jourd'heuil F, Pham LGC, Gilliard K, Howard D, Balnis J, Jaitovich A, Chittur SV, Rilley M, Peredo-Wende R, Ammoura I, Shin SJ, Barroso M, Barra J, Shishkova E, Coon JJ, Lopez-Soler RI, Jourd'heuil D. Regulation of DNA damage and transcriptional output in the vasculature through a cytoglobin-HMGB2 axis. Redox Biol 2023; 65:102838. [PMID: 37573836 PMCID: PMC10428073 DOI: 10.1016/j.redox.2023.102838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 07/24/2023] [Accepted: 08/02/2023] [Indexed: 08/15/2023] Open
Abstract
Identifying novel regulators of vascular smooth muscle cell function is necessary to further understand cardiovascular diseases. We previously identified cytoglobin, a hemoglobin homolog, with myogenic and cytoprotective roles in the vasculature. The specific mechanism of action of cytoglobin is unclear but does not seem to be related to oxygen transport or storage like hemoglobin. Herein, transcriptomic profiling of injured carotid arteries in cytoglobin global knockout mice revealed that cytoglobin deletion accelerated the loss of contractile genes and increased DNA damage. Overall, we show that cytoglobin is actively translocated into the nucleus of vascular smooth muscle cells through a redox signal driven by NOX4. We demonstrate that nuclear cytoglobin heterodimerizes with the non-histone chromatin structural protein HMGB2. Our results are consistent with a previously unknown function by which a non-erythrocytic hemoglobin inhibits DNA damage and regulates gene programs in the vasculature by modulating the genome-wide binding of HMGB2.
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Affiliation(s)
- Clinton Mathai
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, NY, USA
| | - Frances Jourd'heuil
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, NY, USA
| | - Le Gia Cat Pham
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, NY, USA
| | - Kurrim Gilliard
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, NY, USA
| | - Dennis Howard
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, NY, USA
| | - Joseph Balnis
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, NY, USA; Division of Pulmonary and Critical Care Medicine, Albany Medical College, Albany, NY, USA
| | - Ariel Jaitovich
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, NY, USA; Division of Pulmonary and Critical Care Medicine, Albany Medical College, Albany, NY, USA
| | - Sridar V Chittur
- Center for Functional Genomics, Cancer Research Center, University at Albany, New York, 12144, USA
| | - Mark Rilley
- Division of Rheumatology, Department of Medicine, Samuel Stratton VA Medical Center, Albany, NY, 12208, USA
| | - Ruben Peredo-Wende
- Division of Rheumatology, Department of Medicine, Samuel Stratton VA Medical Center, Albany, NY, 12208, USA
| | - Ibrahim Ammoura
- Department of Pathology and Medicine, Albany Medical Center, Albany, NY, 12208, USA
| | - Sandra J Shin
- Department of Pathology and Medicine, Albany Medical Center, Albany, NY, 12208, USA
| | - Margarida Barroso
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, NY, USA
| | - Jonathan Barra
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, NY, USA
| | - Evgenia Shishkova
- National Center for Quantitative Biology of Complex Systems, Madison, WI, 53706, USA; Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI, 53506, USA
| | - Joshua J Coon
- Department of Pathology and Medicine, Albany Medical Center, Albany, NY, 12208, USA; Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI, 53506, USA; Morgridge Institute for Research, Madison, WI, 53515, USA; Department of Chemistry, University of Wisconsin-Madison, Madison, WI, 53506, USA
| | - Reynold I Lopez-Soler
- Section of Renal Transplantation, Edward Hines VA Jr. Hospital, Hines, IL, 60141, USA; Department of Surgery, Division of Intra-Abdominal Transplantation, Stritch School of Medicine, Maywood, IL, 60153, USA
| | - David Jourd'heuil
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, NY, USA.
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6
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Gardner AM, Gardner PR. Dioxygen and glucose force motion of the electron-transfer switch in the iron(III) flavohemoglobin-type nitric oxide dioxygenase. J Inorg Biochem 2023; 245:112257. [PMID: 37229820 DOI: 10.1016/j.jinorgbio.2023.112257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2022] [Revised: 04/28/2023] [Accepted: 05/11/2023] [Indexed: 05/27/2023]
Abstract
Kinetic and structural investigations of the flavohemoglobin-type NO dioxygenase have suggested critical roles for transient Fe(III)O2 complex formation and O2-forced movements affecting hydride transfer to the FAD cofactor and electron-transfer to the Fe(III)O2 complex. Stark-effect theory together with structural models and dipole and internal electrostatic field determinations provided a semi-quantitative spectroscopic method for investigating the proposed Fe(III)O2 complex and O2-forced movements. Deoxygenation of the enzyme causes Stark effects on the ferric heme Soret and charge-transfer bands revealing the Fe(III)O2 complex. Deoxygenation also elicits Stark effects on the FAD that expose forces and motions that create a more restricted NADH access to FAD for hydride transfer and switch electron-transfer off. Glucose also forces the enzyme toward an off state. Amino acid substitutions at the B10, E7, E11, G8, D5, and F7 positions influence the Stark effects of O2 on resting heme spin states and FAD consistent with the proposed roles of the side chains in the enzyme mechanism. Deoxygenation of ferric myoglobin and hemoglobin A also induces Stark effects on the hemes suggesting a common 'oxy-met' state. The ferric myoglobin and hemoglobin heme spectra are also glucose-responsive. A conserved glucose or glucose-6-phosphate binding site is found bridging the BC-corner and G-helix in flavohemoglobin and myoglobin suggesting novel allosteric effector roles for glucose or glucose-6-phosphate in the NO dioxygenase and O2 storage functions. The results support the proposed roles of a ferric O2 intermediate and protein motions in regulating electron-transfer during NO dioxygenase turnover.
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Affiliation(s)
- Anne M Gardner
- Research and Development Division, Miami Valley Biotech, Suite 2445, 1001 E. 2(nd) Street, Dayton, OH 45402, USA; Division of Critical Care Medicine, Cincinnati Children's Hospital Medical Center, R033, 3333 Burnet Avenue, Cincinnati, OH 45229, USA.
| | - Paul R Gardner
- Research and Development Division, Miami Valley Biotech, Suite 2445, 1001 E. 2(nd) Street, Dayton, OH 45402, USA; Division of Critical Care Medicine, Cincinnati Children's Hospital Medical Center, R033, 3333 Burnet Avenue, Cincinnati, OH 45229, USA; Chemistry and Biochemistry Department, University of Dayton, 300 College Park, Dayton, OH 45469, USA.
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7
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Mathai C, Jourd'heuil F, Pham LGC, Gilliard K, Howard D, Balnis J, Jaitovich A, Chittur SV, Rilley M, Peredo-Wende R, Ammoura I, Shin SJ, Barroso M, Barra J, Shishkova E, Coon JJ, Lopez-Soler RI, Jourd'heuil D. Nuclear cytoglobin associates with HMGB2 and regulates DNA damage and genome-wide transcriptional output in the vasculature. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.10.540045. [PMID: 37214992 PMCID: PMC10197644 DOI: 10.1101/2023.05.10.540045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Identifying novel regulators of vascular smooth muscle cell function is necessary to further understand cardiovascular diseases. We previously identified cytoglobin, a hemoglobin homolog, with myogenic and cytoprotective roles in the vasculature. The specific mechanism of action of cytoglobin is unclear but does not seem to be related to oxygen transport or storage like hemoglobin. Herein, transcriptomic profiling of injured carotid arteries in cytoglobin global knockout mice revealed that cytoglobin deletion accelerated the loss of contractile genes and increased DNA damage. Overall, we show that cytoglobin is actively translocated into the nucleus of vascular smooth muscle cells through a redox signal driven by NOX4. We demonstrate that nuclear cytoglobin heterodimerizes with the non-histone chromatin structural protein HMGB2. Our results are consistent with a previously unknown function by which a non-erythrocytic hemoglobin inhibits DNA damage and regulates gene programs in the vasculature by modulating the genome-wide binding of HMGB2.
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8
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Abstract
Resistance arteries and arterioles evolved as specialized blood vessels serving two important functions: (a) regulating peripheral vascular resistance and blood pressure and (b) matching oxygen and nutrient delivery to metabolic demands of organs. These functions require control of vessel lumen cross-sectional area (vascular tone) via coordinated vascular cell responses governed by precise spatial-temporal communication between intracellular signaling pathways. Herein, we provide a contemporary overview of the significant roles that redox switches play in calcium signaling for orchestrated endothelial, smooth muscle, and red blood cell control of arterial vascular tone. Three interrelated themes are the focus: (a) smooth muscle to endothelial communication for vasoconstriction, (b) endothelial to smooth muscle cell cross talk for vasodilation, and (c) oxygen and red blood cell interregulation of vascular tone and blood flow. We intend for this thematic framework to highlight gaps in our current knowledge and potentially spark interest for cross-disciplinary studies moving forward.
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Affiliation(s)
- Máté Katona
- Pittsburgh Heart, Lung, and Blood Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, Pennsylvania, USA;
| | - Mark T Gladwin
- Pittsburgh Heart, Lung, and Blood Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, Pennsylvania, USA;
- Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- Current affiliation: University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Adam C Straub
- Pittsburgh Heart, Lung, and Blood Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, Pennsylvania, USA;
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- Center for Microvascular Research, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
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9
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Hall R, Yuan S, Wood K, Katona M, Straub AC. Cytochrome b5 reductases: Redox regulators of cell homeostasis. J Biol Chem 2022; 298:102654. [PMID: 36441026 PMCID: PMC9706631 DOI: 10.1016/j.jbc.2022.102654] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 10/24/2022] [Accepted: 10/26/2022] [Indexed: 11/06/2022] Open
Abstract
The cytochrome-b5 reductase (CYB5R) family of flavoproteins is known to regulate reduction-oxidation (redox) balance in cells. The five enzyme members are highly compartmentalized at the subcellular level and function as "redox switches" enabling the reduction of several substrates, such as heme and coenzyme Q. Critical insight into the physiological and pathophysiological significance of CYB5R enzymes has been gleaned from several human genetic variants that cause congenital disease and a broad spectrum of chronic human diseases. Among the CYB5R genetic variants, CYB5R3 is well-characterized and deficiency in expression and activity is associated with type II methemoglobinemia, cancer, neurodegenerative disorders, diabetes, and cardiovascular disease. Importantly, pharmacological and genetic-based strategies are underway to target CYB5R3 to circumvent disease onset and mitigate severity. Despite our knowledge of CYB5R3 in human health and disease, the other reductases in the CYB5R family have been understudied, providing an opportunity to unravel critical function(s) for these enzymes in physiology and disease. In this review, we aim to provide the broad scientific community an up-to-date overview of the molecular, cellular, physiological, and pathophysiological roles of CYB5R proteins.
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Affiliation(s)
- Robert Hall
- Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, Pennsylvania, USA; Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Shuai Yuan
- Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Katherine Wood
- Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Mate Katona
- Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Adam C Straub
- Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, Pennsylvania, USA; Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA; Center for Microvascular Research, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
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10
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Iyanagi T. Roles of Ferredoxin-NADP + Oxidoreductase and Flavodoxin in NAD(P)H-Dependent Electron Transfer Systems. Antioxidants (Basel) 2022; 11:2143. [PMID: 36358515 PMCID: PMC9687028 DOI: 10.3390/antiox11112143] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 10/19/2022] [Accepted: 10/20/2022] [Indexed: 07/21/2023] Open
Abstract
Distinct isoforms of FAD-containing ferredoxin-NADP+ oxidoreductase (FNR) and ferredoxin (Fd) are involved in photosynthetic and non-photosynthetic electron transfer systems. The FNR (FAD)-Fd [2Fe-2S] redox pair complex switches between one- and two-electron transfer reactions in steps involving FAD semiquinone intermediates. In cyanobacteria and some algae, one-electron carrier Fd serves as a substitute for low-potential FMN-containing flavodoxin (Fld) during growth under low-iron conditions. This complex evolves into the covalent FNR (FAD)-Fld (FMN) pair, which participates in a wide variety of NAD(P)H-dependent metabolic pathways as an electron donor, including bacterial sulfite reductase, cytochrome P450 BM3, plant or mammalian cytochrome P450 reductase and nitric oxide synthase isoforms. These electron transfer systems share the conserved Ser-Glu/Asp pair in the active site of the FAD module. In addition to physiological electron acceptors, the NAD(P)H-dependent diflavin reductase family catalyzes a one-electron reduction of artificial electron acceptors such as quinone-containing anticancer drugs. Conversely, NAD(P)H: quinone oxidoreductase (NQO1), which shares a Fld-like active site, functions as a typical two-electron transfer antioxidant enzyme, and the NQO1 and UDP-glucuronosyltransfease/sulfotransferase pairs function as an antioxidant detoxification system. In this review, the roles of the plant FNR-Fd and FNR-Fld complex pairs were compared to those of the diflavin reductase (FAD-FMN) family. In the final section, evolutionary aspects of NAD(P)H-dependent multi-domain electron transfer systems are discussed.
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Affiliation(s)
- Takashi Iyanagi
- Graduate School of Life Science, University of Hyogo, 3-2-1 Koto, Akoh 678-1297, Hyogo, Japan
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11
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Carew NT, Schmidt HM, Yuan S, Galley JC, Hall R, Altmann HM, Hahn SA, Miller MP, Wood KC, Gabris B, Stapleton MC, Hartwick S, Fazzari M, Wu YL, Trebak M, Kaufman BA, McTiernan CF, Schopfer FJ, Navas P, Thibodeau PH, McNamara DM, Salama G, Straub AC. Loss of cardiomyocyte CYB5R3 impairs redox equilibrium and causes sudden cardiac death. J Clin Invest 2022; 132:e147120. [PMID: 36106636 PMCID: PMC9479700 DOI: 10.1172/jci147120] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 07/19/2022] [Indexed: 01/04/2023] Open
Abstract
Sudden cardiac death (SCD) in patients with heart failure (HF) is allied with an imbalance in reduction and oxidation (redox) signaling in cardiomyocytes; however, the basic pathways and mechanisms governing redox homeostasis in cardiomyocytes are not fully understood. Here, we show that cytochrome b5 reductase 3 (CYB5R3), an enzyme known to regulate redox signaling in erythrocytes and vascular cells, is essential for cardiomyocyte function. Using a conditional cardiomyocyte-specific CYB5R3-knockout mouse, we discovered that deletion of CYB5R3 in male, but not female, adult cardiomyocytes causes cardiac hypertrophy, bradycardia, and SCD. The increase in SCD in CYB5R3-KO mice is associated with calcium mishandling, ventricular fibrillation, and cardiomyocyte hypertrophy. Molecular studies reveal that CYB5R3-KO hearts display decreased adenosine triphosphate (ATP), increased oxidative stress, suppressed coenzyme Q levels, and hemoprotein dysregulation. Finally, from a translational perspective, we reveal that the high-frequency missense genetic variant rs1800457, which translates into a CYB5R3 T117S partial loss-of-function protein, associates with decreased event-free survival (~20%) in Black persons with HF with reduced ejection fraction (HFrEF). Together, these studies reveal a crucial role for CYB5R3 in cardiomyocyte redox biology and identify a genetic biomarker for persons of African ancestry that may potentially increase the risk of death from HFrEF.
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Affiliation(s)
- Nolan T. Carew
- Heart, Lung, Blood and Vascular Medicine Institute
- Department of Pharmacology and Chemical Biology
| | - Heidi M. Schmidt
- Heart, Lung, Blood and Vascular Medicine Institute
- Department of Pharmacology and Chemical Biology
| | - Shuai Yuan
- Heart, Lung, Blood and Vascular Medicine Institute
| | - Joseph C. Galley
- Heart, Lung, Blood and Vascular Medicine Institute
- Department of Pharmacology and Chemical Biology
| | - Robert Hall
- Heart, Lung, Blood and Vascular Medicine Institute
- Department of Pharmacology and Chemical Biology
| | | | | | | | - Katherine C. Wood
- Heart, Lung, Blood and Vascular Medicine Institute
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, and
| | - Bethann Gabris
- Division of Cardiology, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Margaret C. Stapleton
- Department of Developmental Biology and Rangos Research Center Animal Imaging Core, Children’s Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Sean Hartwick
- Department of Developmental Biology and Rangos Research Center Animal Imaging Core, Children’s Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | | | - Yijen L. Wu
- Department of Developmental Biology and Rangos Research Center Animal Imaging Core, Children’s Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Mohamed Trebak
- Heart, Lung, Blood and Vascular Medicine Institute
- Department of Pharmacology and Chemical Biology
| | - Brett A. Kaufman
- Heart, Lung, Blood and Vascular Medicine Institute
- Division of Cardiology, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Charles F. McTiernan
- Heart, Lung, Blood and Vascular Medicine Institute
- Division of Cardiology, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Francisco J. Schopfer
- Heart, Lung, Blood and Vascular Medicine Institute
- Department of Pharmacology and Chemical Biology
| | - Placido Navas
- Andalusian Center for Developmental Biology and Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Universidad Pablo de Olavide-CSIC-JA, Sevilla, Spain
| | | | - Dennis M. McNamara
- Division of Cardiology, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Guy Salama
- Heart, Lung, Blood and Vascular Medicine Institute
- Division of Cardiology, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Adam C. Straub
- Heart, Lung, Blood and Vascular Medicine Institute
- Department of Pharmacology and Chemical Biology
- Center for Microvascular Research, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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12
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Kaliszuk SJ, Morgan NI, Ayers TN, Sparacino Watkins CE, DeMartino AW, Bocian K, Ragireddy V, Tong Q, Tejero J. Regulation of nitrite reductase and lipid binding properties of cytoglobin by surface and distal histidine mutations. Nitric Oxide 2022; 125-126:12-22. [PMID: 35667547 PMCID: PMC9283305 DOI: 10.1016/j.niox.2022.06.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 05/21/2022] [Accepted: 06/01/2022] [Indexed: 12/30/2022]
Abstract
Cytoglobin is a hemoprotein widely expressed in fibroblasts and related cell lineages with yet undefined physiological function. Cytoglobin, as other heme proteins, can reduce nitrite to nitric oxide (NO) providing a route to generate NO in vivo in low oxygen conditions. In addition, cytoglobin can also bind lipids such as oleic acid and cardiolipin with high affinity. These two processes are potentially relevant to cytoglobin function. Little is known about how specific amino acids contribute to nitrite reduction and lipid binding. Here we investigate the role of the distal histidine His81 (E7) and several surface residues on the regulation of nitrite reduction and lipid binding. We observe that the replacement of His81 (E7) greatly increases heme reactivity towards nitrite, with nitrite reduction rate constants of up to 1100 M-1s-1 for the His81Ala mutant. His81 (E7) mutation causes a small decrease in lipid binding affinity, however experiments on the presence of imidazole indicate that His81 (E7) does not compete with the lipid for the binding site. Mutations of the surface residues Arg84 and Lys116 largely impair lipid binding. Our results suggest that dissociation of His81 (E7) from the heme mediates the formation of a hydrophobic cavity in the proximal heme side that can accommodate the lipid, with important contributions of the hydrophobic patch around residues Thr91, Val105, and Leu108, whereas the positive charges from Arg84 and Lys116 stabilize the carboxyl group of the fatty acid. Gain and loss-of-function mutations described here can serve as tools to study in vivo the physiological role of these putative cytoglobin functions.
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Affiliation(s)
- Stefan J Kaliszuk
- Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, 15261, USA
| | - Natasha I Morgan
- Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, 15261, USA
| | - Taylor N Ayers
- Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, 15261, USA
| | - Courtney E Sparacino Watkins
- Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, 15261, USA; Division of Pulmonary, Allergy and Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA, 15261, USA
| | - Anthony W DeMartino
- Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, 15261, USA
| | - Kaitlin Bocian
- Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, 15261, USA
| | - Venkata Ragireddy
- Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, 15261, USA
| | - Qin Tong
- Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, 15261, USA
| | - Jesús Tejero
- Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, 15261, USA; Division of Pulmonary, Allergy and Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA, 15261, USA; Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA, 15260, USA; Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, 15261, USA.
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13
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Giordano D, Verde C, Corti P. Nitric Oxide Production and Regulation in the Teleost Cardiovascular System. Antioxidants (Basel) 2022; 11:antiox11050957. [PMID: 35624821 PMCID: PMC9137985 DOI: 10.3390/antiox11050957] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 05/06/2022] [Accepted: 05/09/2022] [Indexed: 01/08/2023] Open
Abstract
Nitric Oxide (NO) is a free radical with numerous critical signaling roles in vertebrate physiology. Similar to mammals, in the teleost system the generation of sufficient amounts of NO is critical for the physiological function of the cardiovascular system. At the same time, NO amounts are strictly controlled and kept within basal levels to protect cells from NO toxicity. Changes in oxygen tension highly influence NO bioavailability and can modulate the mechanisms involved in maintaining the NO balance. While NO production and signaling appears to have general similarities with mammalian systems, the wide range of environmental adaptations made by fish, particularly with regards to differing oxygen availabilities in aquatic habitats, creates a foundation for a variety of in vivo models characterized by different implications of NO production and signaling. In this review, we present the biology of NO in the teleost cardiovascular system and summarize the mechanisms of NO production and signaling with a special emphasis on the role of globin proteins in NO metabolism.
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Affiliation(s)
- Daniela Giordano
- Institute of Biosciences and BioResources (IBBR), National Research Council (CNR), Via Pietro Castellino 111, 80131 Napoli, Italy; (D.G.); (C.V.)
- Department of Marine Biotechnology, Stazione Zoologica Anton Dohrn (SZN), Villa Comunale, 80121 Napoli, Italy
| | - Cinzia Verde
- Institute of Biosciences and BioResources (IBBR), National Research Council (CNR), Via Pietro Castellino 111, 80131 Napoli, Italy; (D.G.); (C.V.)
- Department of Marine Biotechnology, Stazione Zoologica Anton Dohrn (SZN), Villa Comunale, 80121 Napoli, Italy
| | - Paola Corti
- Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA 15213, USA
- Division of Cardiology, Department of Medicine, University of Pittsburgh, Pittsburgh, PA 15213, USA
- Correspondence:
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14
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Mahgoup EM, Khaleel SA, El-Mahdy MA, Abd-Allah AR, Zweier JL. Role of cytoglobin in cigarette smoke constituent-induced loss of nitric oxide bioavailability in vascular smooth muscle cells. Nitric Oxide 2022; 119:9-18. [PMID: 34875385 PMCID: PMC8752519 DOI: 10.1016/j.niox.2021.12.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 11/22/2021] [Accepted: 12/03/2021] [Indexed: 02/03/2023]
Abstract
Cytoglobin (Cygb) has been identified as the major nitric oxide (NO) metabolizing protein in vascular smooth muscle cells (VSMCs) and is crucial for the regulation of vascular tone. In the presence of its requisite cytochrome B5a (B5)/B5 reductase-isoform-3 (B5R) reducing system, Cygb controls NO metabolism through the oxygen-dependent process of NO dioxygenation. Tobacco cigarette smoking (TCS) induces vascular dysfunction; however, the role of Cygb in the pathophysiology of TCS-induced cardiovascular disease has not been previously investigated. While TCS impairs NO biosynthesis, its effect on NO metabolism remains unclear. Therefore, we performed studies in aortic VSMCs with tobacco smoke extract (TSE) exposure to investigate the effects of cigarette smoke constituents on the rates of NO decay, with focus on the alterations that occur in the process of Cygb-mediated NO metabolism. TSE greatly enhanced the rates of NO metabolism by VSMCs. An initial increase in superoxide-mediated NO degradation was seen at 4 h of exposure. This was followed by much larger progressive increases at 24 and 48 h, accompanied by parallel increases in the expression of Cygb and B5/B5R. siRNA-mediated Cygb knockdown greatly decreased these TSE-induced elevations in NO decay rates. Therefore, upregulation of the levels of Cygb and its reducing system accounted for the large increase in NO metabolism rate seen after 24 h of TSE exposure. Thus, increased Cygb-mediated NO degradation would contribute to TCS-induced vascular dysfunction and partial inhibition of Cygb expression or its NO dioxygenase function could be a promising therapeutic target to prevent secondary cardiovascular disease.
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Affiliation(s)
- Elsayed M Mahgoup
- Department of Internal Medicine, Division of Cardiovascular Medicine, And the EPR Center, Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University, Columbus, OH, 43210, USA; Department of Pharmacology and Toxicology, College of Pharmacy, Al-Azhar University, Cairo, Egypt
| | - Sahar A Khaleel
- Department of Internal Medicine, Division of Cardiovascular Medicine, And the EPR Center, Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University, Columbus, OH, 43210, USA; Department of Pharmacology and Toxicology, College of Pharmacy, Al-Azhar University, Cairo, Egypt
| | - Mohamed A El-Mahdy
- Department of Internal Medicine, Division of Cardiovascular Medicine, And the EPR Center, Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University, Columbus, OH, 43210, USA; Department of Pharmacology and Toxicology, College of Pharmacy, Al-Azhar University, Cairo, Egypt
| | - Adel R Abd-Allah
- Department of Pharmacology and Toxicology, College of Pharmacy, Al-Azhar University, Cairo, Egypt
| | - Jay L Zweier
- Department of Internal Medicine, Division of Cardiovascular Medicine, And the EPR Center, Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University, Columbus, OH, 43210, USA.
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15
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Kiger L, Keith J, Freiwan A, Fernandez AG, Tillman H, Isakson BE, Weiss MJ, Lechauve C. Redox-Regulation of α-Globin in Vascular Physiology. Antioxidants (Basel) 2022; 11:antiox11010159. [PMID: 35052663 PMCID: PMC8773178 DOI: 10.3390/antiox11010159] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 01/07/2022] [Accepted: 01/11/2022] [Indexed: 12/22/2022] Open
Abstract
Interest in the structure, function, and evolutionary relations of circulating and intracellular globins dates back more than 60 years to the first determination of the three-dimensional structure of these proteins. Non-erythrocytic globins have been implicated in circulatory control through reactions that couple nitric oxide (NO) signaling with cellular oxygen availability and redox status. Small artery endothelial cells (ECs) express free α-globin, which causes vasoconstriction by degrading NO. This reaction converts reduced (Fe2+) α-globin to the oxidized (Fe3+) form, which is unstable, cytotoxic, and unable to degrade NO. Therefore, (Fe3+) α-globin must be stabilized and recycled to (Fe2+) α-globin to reinitiate the catalytic cycle. The molecular chaperone α-hemoglobin-stabilizing protein (AHSP) binds (Fe3+) α-globin to inhibit its degradation and facilitate its reduction. The mechanisms that reduce (Fe3+) α-globin in ECs are unknown, although endothelial nitric oxide synthase (eNOS) and cytochrome b5 reductase (CyB5R3) with cytochrome b5 type A (CyB5a) can reduce (Fe3+) α-globin in solution. Here, we examine the expression and cellular localization of eNOS, CyB5a, and CyB5R3 in mouse arterial ECs and show that α-globin can be reduced by either of two independent redox systems, CyB5R3/CyB5a and eNOS. Together, our findings provide new insights into the regulation of blood vessel contractility.
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Affiliation(s)
- Laurent Kiger
- Inserm U955, Institut Mondor de Recherche Biomédicale, University Paris Est Creteil, 94017 Créteil, France;
| | - Julia Keith
- Department of Hematology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA; (J.K.); (A.G.F.); (M.J.W.)
| | - Abdullah Freiwan
- Department of Bone Marrow Transplantation and Cellular Therapy, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA;
| | - Alfonso G. Fernandez
- Department of Hematology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA; (J.K.); (A.G.F.); (M.J.W.)
| | - Heather Tillman
- Department of Pathology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA;
| | - Brant E. Isakson
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA 22908, USA;
| | - Mitchell J. Weiss
- Department of Hematology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA; (J.K.); (A.G.F.); (M.J.W.)
| | - Christophe Lechauve
- Department of Hematology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA; (J.K.); (A.G.F.); (M.J.W.)
- Correspondence: ; Tel.: +1-(901)-595-8344; Fax: +1-(901)-595-4723
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16
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Gardner PR. Ordered Motions in the Nitric-Oxide Dioxygenase Mechanism of Flavohemoglobin and Assorted Globins with Tightly Coupled Reductases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1414:45-96. [PMID: 36520413 DOI: 10.1007/5584_2022_751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Nitric-oxide dioxygenases (NODs) activate and combine O2 with NO to form nitrate. A variety of oxygen-binding hemoglobins with associated partner reductases or electron donors function as enzymatic NODs. Kinetic and structural investigations of the archetypal two-domain microbial flavohemoglobin-NOD have illuminated an allosteric mechanism that employs selective tunnels for O2 and NO, gates for NO and nitrate, transient O2 association with ferric heme, and an O2 and NO-triggered, ferric heme spin crossover-driven, motion-controlled, and dipole-regulated electron-transfer switch. The proposed mechanism facilitates radical-radical coupling of ferric-superoxide with NO to form nitrate while preventing suicidal ferrous-NO formation. Diverse globins display the structural and functional motifs necessary for a similar allosteric NOD mechanism. In silico docking simulations reveal monomeric erythrocyte hemoglobin alpha-chain and beta-chain intrinsically matched and tightly coupled with NADH-cytochrome b5 oxidoreductase and NADPH-cytochrome P450 oxidoreductase, respectively, forming membrane-bound flavohemoglobin-like mammalian NODs. The neuroprotective neuroglobin manifests a potential NOD role in a close-fitting ternary complex with membrane-bound NADH-cytochrome b5 oxidoreductase and cytochrome b5. Cytoglobin interfaces weakly with cytochrome b5 for O2 and NO-regulated electron-transfer and coupled NOD activity. The mechanistic model also provides insight into the evolution of O2 binding cooperativity in hemoglobin and a basis for the discovery of allosteric NOD inhibitors.
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17
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Zweier JL, Hemann C, Kundu T, Ewees MG, Khaleel SA, Samouilov A, Ilangovan G, El-Mahdy MA. Cytoglobin has potent superoxide dismutase function. Proc Natl Acad Sci U S A 2021; 118:e2105053118. [PMID: 34930834 PMCID: PMC8719900 DOI: 10.1073/pnas.2105053118] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/21/2021] [Indexed: 12/13/2022] Open
Abstract
Cytoglobin (Cygb) was discovered as a novel type of globin that is expressed in mammals; however, its functions remain uncertain. While Cygb protects against oxidant stress, the basis for this is unclear, and the effect of Cygb on superoxide metabolism is unknown. From dose-dependent studies of the effect of Cygb on superoxide catabolism, we identify that Cygb has potent superoxide dismutase (SOD) function. Initial assays using cytochrome c showed that Cygb exhibits a high rate of superoxide dismutation on the order of 108 M-1 ⋅ s-1 Spin-trapping studies also demonstrated that the rate of Cygb-mediated superoxide dismutation (1.6 × 108 M-1 ⋅ s-1) was only ∼10-fold less than Cu,Zn-SOD. Stopped-flow experiments confirmed that Cygb rapidly dismutates superoxide with rates within an order of magnitude of Cu,Zn-SOD or Mn-SOD. The SOD function of Cygb was inhibited by cyanide and CO that coordinate to Fe3+-Cygb and Fe2+-Cygb, respectively, suggesting that dismutation involves iron redox cycling, and this was confirmed by spectrophotometric titrations. In control smooth-muscle cells and cells with siRNA-mediated Cygb knockdown subjected to extracellular superoxide stress from xanthine/xanthine oxidase or intracellular superoxide stress triggered by the uncoupler, menadione, Cygb had a prominent role in superoxide metabolism and protected against superoxide-mediated death. Similar experiments in vessels showed higher levels of superoxide in Cygb-/- mice than wild type. Thus, Cygb has potent SOD function and can rapidly dismutate superoxide in cells, conferring protection against oxidant injury. In view of its ubiquitous cellular expression at micromolar concentrations in smooth-muscle and other cells, Cygb can play an important role in cellular superoxide metabolism.
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Affiliation(s)
- Jay L Zweier
- Department of Internal Medicine, Division of Cardiovascular Medicine, The Ohio State University, Columbus, OH 43210;
- Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University, Columbus, OH 43210
| | - Craig Hemann
- Department of Internal Medicine, Division of Cardiovascular Medicine, The Ohio State University, Columbus, OH 43210
- Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University, Columbus, OH 43210
| | - Tapan Kundu
- Department of Internal Medicine, Division of Cardiovascular Medicine, The Ohio State University, Columbus, OH 43210
- Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University, Columbus, OH 43210
| | - Mohamed G Ewees
- Department of Internal Medicine, Division of Cardiovascular Medicine, The Ohio State University, Columbus, OH 43210
- Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University, Columbus, OH 43210
| | - Sahar A Khaleel
- Department of Internal Medicine, Division of Cardiovascular Medicine, The Ohio State University, Columbus, OH 43210
- Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University, Columbus, OH 43210
| | - Alexandre Samouilov
- Department of Internal Medicine, Division of Cardiovascular Medicine, The Ohio State University, Columbus, OH 43210
- Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University, Columbus, OH 43210
| | - Govindasamy Ilangovan
- Department of Internal Medicine, Division of Cardiovascular Medicine, The Ohio State University, Columbus, OH 43210
- Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University, Columbus, OH 43210
| | - Mohamed A El-Mahdy
- Department of Internal Medicine, Division of Cardiovascular Medicine, The Ohio State University, Columbus, OH 43210
- Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University, Columbus, OH 43210
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18
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Dent MR, DeMartino AW, Tejero J, Gladwin MT. Endogenous Hemoprotein-Dependent Signaling Pathways of Nitric Oxide and Nitrite. Inorg Chem 2021; 60:15918-15940. [PMID: 34313417 PMCID: PMC9167621 DOI: 10.1021/acs.inorgchem.1c01048] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Interdisciplinary research at the interface of chemistry, physiology, and biomedicine have uncovered pivotal roles of nitric oxide (NO) as a signaling molecule that regulates vascular tone, platelet aggregation, and other pathways relevant to human health and disease. Heme is central to physiological NO signaling, serving as the active site for canonical NO biosynthesis in nitric oxide synthase (NOS) enzymes and as the highly selective NO binding site in the soluble guanylyl cyclase receptor. Outside of the primary NOS-dependent biosynthetic pathway, other hemoproteins, including hemoglobin and myoglobin, generate NO via the reduction of nitrite. This auxiliary hemoprotein reaction unlocks a "second axis" of NO signaling in which nitrite serves as a stable NO reservoir. In this Forum Article, we highlight these NO-dependent physiological pathways and examine complex chemical and biochemical reactions that govern NO and nitrite signaling in vivo. We focus on hemoprotein-dependent reaction pathways that generate and consume NO in the presence of nitrite and consider intermediate nitrogen oxides, including NO2, N2O3, and S-nitrosothiols, that may facilitate nitrite-based signaling in blood vessels and tissues. We also discuss emergent therapeutic strategies that leverage our understanding of these key reaction pathways to target NO signaling and treat a wide range of diseases.
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Affiliation(s)
- Matthew R Dent
- Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States
| | - Anthony W DeMartino
- Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States
| | - Jesús Tejero
- Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States
- Division of Pulmonary, Allergy and Critical Care Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States
| | - Mark T Gladwin
- Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States
- Division of Pulmonary, Allergy and Critical Care Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
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19
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DeMartino AW, Amdahl MB, Bocian K, Rose JJ, Tejero J, Gladwin MT. Redox sensor properties of human cytoglobin allosterically regulate heme pocket reactivity. Free Radic Biol Med 2021; 162:423-434. [PMID: 33144263 PMCID: PMC7889637 DOI: 10.1016/j.freeradbiomed.2020.10.321] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 10/21/2020] [Accepted: 10/28/2020] [Indexed: 12/12/2022]
Abstract
Cytoglobin is a conserved hemoprotein ubiquitously expressed in mammalian tissues, which conducts electron transfer reactions with proposed signaling functions in nitric oxide (NO) and lipid metabolism. Cytoglobin has an E7 distal histidine (His81), which unlike related globins such as myoglobin and hemoglobin, is in equilibrium between a bound, hexacoordinate state and an unbound, pentacoordinate state. The His81 binding equilibrium appears to be allosterically modulated by the presence of an intramolecular disulfide between two cysteines (Cys38 and Cys83). The formation of this disulfide bridge regulates nitrite reductase activity and lipid binding. Herein, we attempt to clarify the effects of defined thiol oxidation states on small molecule binding of cytoglobin heme, using cyanide binding to probe the ferric state. Cyanide binding kinetics to wild-type cytoglobin reveal at least two kinetically distinct subpopulations, depending on thiol oxidation states. Experiments with covalent thiol modification by NEM, glutathione, and amino acid substitutions (C38S, C83S and H81A), indicate that subpopulations ranging from fully reduced thiols, single thiol oxidation, and intramolecular disulfide formation determine heme binding properties by modulating the histidine-heme affinity and ligand binding. The redox modulation of ligand binding is sensitive to physiological levels of hydrogen peroxide, with a functional midpoint redox potential for the native cytoglobin intramolecular disulfide bond of -189 ± 4 mV, a value within the boundaries of intracellular redox potentials. These results support the hypothesis that Cys38 and Cys83 on cytoglobin serve as sensitive redox sensors that modulate the cytoglobin distal heme pocket reactivity and ligand binding.
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Affiliation(s)
- Anthony W DeMartino
- Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, United States
| | - Matthew B Amdahl
- Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, United States
| | - Kaitlin Bocian
- Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, United States
| | - Jason J Rose
- Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, United States; Division of Pulmonary, Allergy and Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA, 15261, United States; Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, 15260, United States
| | - Jesús Tejero
- Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, United States; Division of Pulmonary, Allergy and Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA, 15261, United States; Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, 15260, United States; Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, 15261, United States.
| | - Mark T Gladwin
- Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, United States; Division of Pulmonary, Allergy and Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA, 15261, United States; Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, 15260, United States.
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20
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Ilangovan G, Khaleel SA, Kundu T, Hemann C, El-Mahdy MA, Zweier JL. Defining the reducing system of the NO dioxygenase cytoglobin in vascular smooth muscle cells and its critical role in regulating cellular NO decay. J Biol Chem 2020; 296:100196. [PMID: 33334890 PMCID: PMC7948950 DOI: 10.1074/jbc.ra120.016394] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 12/07/2020] [Accepted: 12/15/2020] [Indexed: 12/27/2022] Open
Abstract
In smooth muscle, cytoglobin (Cygb) functions as a potent nitric oxide (NO) dioxygenase and regulates NO metabolism and vascular tone. Major questions remain regarding which cellular reducing systems regulate Cygb-mediated NO metabolism. To better define the Cygb-mediated NO dioxygenation process in vascular smooth muscle cells (SMCs), and the requisite reducing systems that regulate cellular NO decay, we assessed the intracellular concentrations of Cygb and its putative reducing systems and examined their roles in the process of NO decay. Cygb and the reducing systems, cytochrome b5 (B5)/cytochrome b5 reductase (B5R) and cytochrome P450 reductase (CPR) were measured in aortic SMCs. Intracellular Cygb concentration was estimated as 3.5 μM, while B5R, B5, and CPR were 0.88, 0.38, and 0.15 μM, respectively. NO decay in SMCs was measured following bolus addition of NO to air-equilibrated cells. siRNA-mediated knockdown experiments indicated that ∼78% of NO metabolism in SMCs is Cygb-dependent. Of this, ∼87% was B5R- and B5-dependent. CPR knockdown resulted in a small decrease in the NO dioxygenation rate (VNO), while depletion of ascorbate had no effect. Kinetic analysis of VNO for the B5/B5R/Cygb system with variation of B5 or B5R concentrations from their SMC levels showed that VNO exhibits apparent Michaelis–Menten behavior for B5 and B5R. In contrast, linear variation was seen with change in Cygb concentration. Overall, B5/B5R was demonstrated to be the major reducing system supporting Cygb-mediated NO metabolism in SMCs with changes in cellular B5/B5R levels modulating the process of NO decay.
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Affiliation(s)
- Govindasamy Ilangovan
- Department of Internal Medicine, Division of Cardiovascular Medicine, and the EPR Center, Davis Heart & Lung Research Institute, College of Medicine, The Ohio State University, Columbus, Ohio, USA
| | - Sahar A Khaleel
- Department of Internal Medicine, Division of Cardiovascular Medicine, and the EPR Center, Davis Heart & Lung Research Institute, College of Medicine, The Ohio State University, Columbus, Ohio, USA; Department of Pharmacology and Toxicology, College of Pharmacy, Al-Azhar University, Cairo, Egypt
| | - Tapan Kundu
- Department of Internal Medicine, Division of Cardiovascular Medicine, and the EPR Center, Davis Heart & Lung Research Institute, College of Medicine, The Ohio State University, Columbus, Ohio, USA
| | - Craig Hemann
- Department of Internal Medicine, Division of Cardiovascular Medicine, and the EPR Center, Davis Heart & Lung Research Institute, College of Medicine, The Ohio State University, Columbus, Ohio, USA
| | - Mohamed A El-Mahdy
- Department of Internal Medicine, Division of Cardiovascular Medicine, and the EPR Center, Davis Heart & Lung Research Institute, College of Medicine, The Ohio State University, Columbus, Ohio, USA
| | - Jay L Zweier
- Department of Internal Medicine, Division of Cardiovascular Medicine, and the EPR Center, Davis Heart & Lung Research Institute, College of Medicine, The Ohio State University, Columbus, Ohio, USA.
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21
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Hughan KS, Levine A, Helbling N, Anthony S, DeLany JP, Stefanovic-Racic M, Goodpaster BH, Gladwin MT. Effects of Oral Sodium Nitrite on Blood Pressure, Insulin Sensitivity, and Intima-Media Arterial Thickening in Adults With Hypertension and Metabolic Syndrome. Hypertension 2020; 76:866-874. [PMID: 32755471 PMCID: PMC7429358 DOI: 10.1161/hypertensionaha.120.14930] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The nitrate-nitrite-NO pathway regulates NO synthase-independent vasodilation and NO signaling. Ingestion of inorganic nitrite has vasodilatory and blood pressure-lowering effects. Preclinical studies in rodent models suggest there may be a benefit of nitrite in lowering serum triglyceride levels and improving the metabolic syndrome. In a phase 2 study, we evaluated the safety and efficacy of chronic oral nitrite therapy in patients with hypertension and the metabolic syndrome. Twenty adult subjects with stage 1 or 2 hypertension and the metabolic syndrome were enrolled in an open-label safety and efficacy study. The primary efficacy end point was blood pressure reduction; secondary end points included insulin-dependent glucose disposal and endothelial function measured by flow-mediated dilation of the brachial artery and intima-media diameter of the carotid artery. Chronic oral nitrite therapy (40 mg/3× daily) was well tolerated. Oral nitrite significantly lowered systolic, diastolic, and mean arterial pressures, but tolerance was observed after 10 to 12 weeks of therapy. There was significant improvement in the intima-media thickness of the carotid artery and trends toward improvements in flow-mediated dilation of the brachial artery and insulin sensitivity. Chronic oral nitrite therapy is safe in patients with hypertension and the metabolic syndrome. Despite an apparent lack of enzymatic tolerance to nitrite, we observed tolerance after 10 weeks of chronic therapy, which requires additional mechanistic studies and possible therapeutic dose titration in clinical trials. Nitrite may be a safe therapy to concominantly improve multiple features of the metabolic syndrome including hypertension, insulin resistance, and endothelial dysfunction. Registration- URL: https://www.clinicaltrials.gov; Unique identifier: NCT01681810.
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Affiliation(s)
- Kara S Hughan
- Department of Pediatrics, Division of Pediatric Endocrinology and Diabetes, University of Pittsburgh, Pittsburgh, PA
- Pittsburgh Heart, Lung, and Blood Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA
| | - Andrea Levine
- Pittsburgh Heart, Lung, and Blood Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA
- Department of Medicine, Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA
- Division of Pulmonary and Critical Care Medicine, University of Maryland School of Medicine, Baltimore, MD
| | - Nicole Helbling
- Department of Medicine, Division of Endocrinology, University of Pittsburgh, Pittsburgh, PA
| | - Steven Anthony
- Department of Medicine, Division of Endocrinology, University of Pittsburgh, Pittsburgh, PA
| | - James P DeLany
- Department of Medicine, Division of Endocrinology, University of Pittsburgh, Pittsburgh, PA
| | - Maja Stefanovic-Racic
- Department of Medicine, Division of Endocrinology, University of Pittsburgh, Pittsburgh, PA
| | - Bret H. Goodpaster
- Department of Medicine, Division of Endocrinology, University of Pittsburgh, Pittsburgh, PA
| | - Mark T. Gladwin
- Pittsburgh Heart, Lung, and Blood Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA
- Department of Medicine, Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA
- Department of Medicine, Division of Endocrinology, University of Pittsburgh, Pittsburgh, PA
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22
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Amdahl MB, DeMartino AW, Gladwin MT. Inorganic nitrite bioactivation and role in physiological signaling and therapeutics. Biol Chem 2020; 401:201-211. [PMID: 31747370 DOI: 10.1515/hsz-2019-0349] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Accepted: 11/02/2019] [Indexed: 01/23/2023]
Abstract
The bioactivation of inorganic nitrite refers to the conversion of otherwise 'inert' nitrite to the diatomic signaling molecule nitric oxide (NO), which plays important roles in human physiology and disease, notably in the regulation of vascular tone and blood flow. While the most well-known sources of NO are the nitric oxide synthase (NOS) enzymes, another source of NO is the nitrate-nitrite-NO pathway, whereby nitrite (obtained from reduction of dietary nitrate) is further reduced to form NO. The past few decades have seen extensive study of the mechanisms of NO generation through nitrate and nitrite bioactivation, as well as growing appreciation of the contribution of this pathway to NO signaling in vivo. This review, prepared for the volume 400 celebration issue of Biological Chemistry, summarizes some of the key reactions of the nitrate-nitrite-NO pathway such as reduction, disproportionation, dehydration, and oxidative denitrosylation, as well as current evidence for the contribution of the pathway to human cardiovascular physiology. Finally, ongoing efforts to develop novel medical therapies for multifarious conditions, especially those related to pathologic vasoconstriction and ischemia/reperfusion injury, are also explored.
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Affiliation(s)
- Matthew B Amdahl
- Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Anthony W DeMartino
- Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Mark T Gladwin
- Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA 15261, USA.,Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA 15213, USA
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23
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Lessons from the post-genomic era: Globin diversity beyond oxygen binding and transport. Redox Biol 2020; 37:101687. [PMID: 32863222 PMCID: PMC7475203 DOI: 10.1016/j.redox.2020.101687] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 08/11/2020] [Accepted: 08/11/2020] [Indexed: 12/16/2022] Open
Abstract
Vertebrate hemoglobin (Hb) and myoglobin (Mb) were among the first proteins whose structures and sequences were determined over 50 years ago. In the subsequent pregenomic period, numerous related proteins came to light in plants, invertebrates and bacteria, that shared the myoglobin fold, a signature sequence motif characteristic of a 3-on-3 α-helical sandwich. Concomitantly, eukaryote and bacterial globins with a truncated 2-on-2 α-helical fold were discovered. Genomic information over the last 20 years has dramatically expanded the list of known globins, demonstrating their existence in a limited number of archaeal genomes, a majority of bacterial genomes and an overwhelming majority of eukaryote genomes. In vertebrates, 6 additional globin types were identified, namely neuroglobin (Ngb), cytoglobin (Cygb), globin E (GbE), globin X (GbX), globin Y (GbY) and androglobin (Adgb). Furthermore, functions beyond the familiar oxygen transport and storage have been discovered within the vertebrate globin family, including NO metabolism, peroxidase activity, scavenging of free radicals, and signaling functions. The extension of the knowledge on globin functions suggests that the original roles of bacterial globins must have been enzymatic, involved in defense against NO toxicity, and perhaps also as sensors of O2, regulating taxis away or towards high O2 concentrations. In this review, we aimed to discuss the evolution and remarkable functional diversity of vertebrate globins with particular focus on the variety of non-canonical expression sites of mammalian globins and their according impressive variability of atypical functions.
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24
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Kapil V, Khambata RS, Jones DA, Rathod K, Primus C, Massimo G, Fukuto JM, Ahluwalia A. The Noncanonical Pathway for In Vivo Nitric Oxide Generation: The Nitrate-Nitrite-Nitric Oxide Pathway. Pharmacol Rev 2020; 72:692-766. [DOI: 10.1124/pr.120.019240] [Citation(s) in RCA: 69] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
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25
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Abstract
Significance: Cytoglobin (Cygb) was discovered as a new addition to the globin superfamily and subsequently identified to have potent nitric oxide (NO) dioxygenase function. Cygb plays a critical role in the oxygen-dependent regulation of NO levels and vascular tone. Recent Advances: In recent years, the mechanism of the Cygb-mediated NO dioxygenation has been studied in isolated protein, smooth muscle cell, isolated blood vessel, and in vivo animal model systems. Studies in Cygb-/- mice have demonstrated that Cygb plays a critical role in regulating blood pressure and vascular tone. This review summarizes advances in the knowledge of NO dioxygenation/metabolism regulated by Cygb. Advances in measurement of NO diffusion dynamics across blood vessels and kinetic modeling of Cygb-mediated NO dioxygenation are summarized. The oxygen-dependent regulation of NO degradation by Cygb is also reviewed along with how Cygb paradoxically generates NO from nitrite under anaerobic conditions. The important role of Cygb in the regulation of vascular function and disease is reviewed. Critical Issues: Cygb is a more potent NO dioxygenase (NOD) than previously known globins with structural differences in heme coordination and environment, conferring it with a higher rate of reduction and more rapid process of NO dioxygenation with unique oxygen dependence. Various cellular reducing systems regenerate the catalytic oxyferrous Cygb species, supporting a high rate of NO dioxygenation. Future Directions: There remains a critical need to further characterize the factors and processes that modulate Cygb-mediated NOD function, and to develop pharmacological or other approaches to modulate Cygb function and expression.
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Affiliation(s)
- Jay L Zweier
- Division of Cardiovascular Medicine, Department of Internal Medicine, Davis Heart and Lung Research Institute, The Ohio State University College of Medicine, Columbus, Ohio, USA
| | - Govindasamy Ilangovan
- Division of Cardiovascular Medicine, Department of Internal Medicine, Davis Heart and Lung Research Institute, The Ohio State University College of Medicine, Columbus, Ohio, USA
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26
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Mathai C, Jourd'heuil FL, Lopez-Soler RI, Jourd'heuil D. Emerging perspectives on cytoglobin, beyond NO dioxygenase and peroxidase. Redox Biol 2020; 32:101468. [PMID: 32087552 PMCID: PMC7033357 DOI: 10.1016/j.redox.2020.101468] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 02/05/2020] [Accepted: 02/13/2020] [Indexed: 12/18/2022] Open
Abstract
Cytoglobin is an evolutionary ancient hemoglobin with poor functional annotation. Rather than constrained to penta coordination, cytoglobin's heme iron may exist either as a penta or hexacoordinated arrangement when exposed to different intracellular environments. Two cysteine residues at the surface of the protein form an intramolecular disulfide bond that regulates iron coordination, ligand binding, and peroxidase activity. Overall, biochemical results do not support a role for cytoglobin as a direct antioxidant enzyme that scavenges hydrogen peroxide because the rate of the reaction of cytoglobin with hydrogen peroxide is several orders of magnitude slower than metal and thiol-based peroxidases. Thus, alternative substrates such as fatty acids have been suggested and regulation of nitric oxide bioavailability through nitric oxide dioxygenase and nitrite reductase activities has received experimental support. Cytoglobin is broadly expressed in connective, muscle, and nervous tissues. Rational for differential cellular distribution is poorly understood but inducibility in response to hypoxia is one of the most established features of cytoglobin expression with regulation through the transcription factor hypoxia-inducible factor (HIF). Phenotypic characterization of cytoglobin deletion in the mouse have indicated broad changes that include a heightened inflammatory response and fibrosis, increase tumor burden, cardiovascular dysfunction, and hallmarks of senescence. Some of these changes might be reversed upon inhibition of nitric oxide synthase. However, subcellular and molecular interactions have been seldom characterized. In addition, specific molecular mechanisms of action are still lacking. We speculate that cytoglobin functionality will extend beyond nitric oxide handling and will have to encompass indirect regulatory antioxidant and redox sensing functions.
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Affiliation(s)
- Clinton Mathai
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, NY, USA
| | - Frances L Jourd'heuil
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, NY, USA
| | | | - David Jourd'heuil
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, NY, USA.
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27
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Rochon ER, Corti P. Globins and nitric oxide homeostasis in fish embryonic development. Mar Genomics 2020; 49:100721. [PMID: 31711848 DOI: 10.1016/j.margen.2019.100721] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 10/07/2019] [Accepted: 10/18/2019] [Indexed: 11/30/2022]
Abstract
Since the discovery of new members of the globin superfamily such as Cytoglobin, Neuroglobin and Globin X, in addition to the most well-known members, Hemoglobin and Myoglobin, different hypotheses have been suggested about their function in vertebrates. Globins are ubiquitously found in living organisms and can carry out different functions based on their ability to bind ligands such as O2, and nitric oxide (NO) and to catalyze reactions scavenging NO or generating NO by reducing nitrite. NO is a highly diffusible molecule with a central role in signaling important for egg maturation, fertilization and early embryonic development. The globins ability to scavenge or generate NO makes these proteins ideal candidates in regulating NO homeostasis depending on the micro environment and tissue NO demands. Different amounts of various globins have been found in zebrafish eggs and developing embryos where it's unlikely that they function as respiratory proteins and instead could play a role in maintaining embryonic NO homeostasis. Here we summarize the current knowledge concerning the role of NO in adult fish in comparison to mammals and we discuss NO function during embryonic development with possible implications for globins in maintaining embryonic NO homeostasis.
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Affiliation(s)
- Elizabeth R Rochon
- Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Paola Corti
- Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA 15213, USA; Division of Cardiology, Department of Medicine, University of Pittsburgh, Pittsburgh, PA 15213, USA.
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28
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Liu Y, Croft KD, Hodgson JM, Mori T, Ward NC. Mechanisms of the protective effects of nitrate and nitrite in cardiovascular and metabolic diseases. Nitric Oxide 2020; 96:35-43. [PMID: 31954804 DOI: 10.1016/j.niox.2020.01.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 12/18/2019] [Accepted: 01/13/2020] [Indexed: 12/28/2022]
Abstract
Within the body, NO is produced by nitric oxide synthases via converting l-arginine to citrulline. Additionally, NO is also produced via the NOS-independent nitrate-nitrite-NO pathway. Unlike the classical pathway, the nitrate-nitrite-NO pathway is oxygen independent and viewed as a back-up function to ensure NO generation during ischaemia/hypoxia. Dietary nitrate and nitrite have emerged as substrates for endogenous NO generation and other bioactive nitrogen oxides with promising protective effects on cardiovascular and metabolic function. In brief, inorganic nitrate and nitrite can decrease blood pressure, protect against ischaemia-reperfusion injury, enhance endothelial function, inhibit platelet aggregation, modulate mitochondrial function and improve features of the metabolic syndrome. However, many questions regarding the specific mechanisms of these protective effects on cardiovascular and metabolic diseases remain unclear. In this review, we focus on nitrate/nitrite bioactivation, as well as the potential mechanisms for nitrate/nitrite-mediated effects on cardiovascular and metabolic diseases. Understanding how dietary nitrate and nitrite induce beneficial effect on cardiovascular and metabolic diseases could open up novel therapeutic opportunities in clinical practice.
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Affiliation(s)
- Yang Liu
- School of Biomedical Sciences, University of Western Australia, Perth, Australia
| | - Kevin D Croft
- School of Biomedical Sciences, University of Western Australia, Perth, Australia
| | - Jonathan M Hodgson
- School of Biomedical Sciences, University of Western Australia, Perth, Australia; School of Medical and Health Sciences, Edith Cowan University, Perth, Australia
| | - Trevor Mori
- Medical School, University of Western Australia, Perth, Australia
| | - Natalie C Ward
- Medical School, University of Western Australia, Perth, Australia; School of Public Health and Curtin Health Innovation Research Institute, Curtin University, Perth, Australia.
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29
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Daane JM, Giordano D, Coppola D, di Prisco G, Detrich HW, Verde C. Adaptations to environmental change: Globin superfamily evolution in Antarctic fishes. Mar Genomics 2019; 49:100724. [PMID: 31735579 DOI: 10.1016/j.margen.2019.100724] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2019] [Revised: 10/27/2019] [Accepted: 11/01/2019] [Indexed: 02/08/2023]
Abstract
The ancient origins and functional versatility of globins make them ideal subjects for studying physiological adaptation to environmental change. Our goals in this review are to describe the evolution of the vertebrate globin gene superfamily and to explore the structure/function relationships of hemoglobin, myoglobin, neuroglobin and cytoglobin in teleost fishes. We focus on the globins of Antarctic notothenioids, emphasizing their adaptive features as inferred from comparisons with human proteins. We dedicate this review to Guido di Prisco, our co-author, colleague, friend, and husband of C.V. Ever thoughtful, creative, and enthusiastic, Guido spearheaded study of the structure, function, and evolution of the hemoglobins of polar fishes - this review is testimony to his wide-ranging contributions. Throughout his career, Guido inspired younger scientists to embrace polar biological research, and he challenged researchers of all ages to explore evolutionary adaptation in the context of global climate change. Beyond his scientific contributions, we will miss his warmth, his culture, and his great intellect. Guido has left an outstanding legacy, one that will continue to inspire us and our research.
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Affiliation(s)
- Jacob M Daane
- Department of Marine and Environmental Sciences, Northeastern University Marine Science Center, Nahant, MA 01908, USA
| | - Daniela Giordano
- Institute of Biosciences and BioResources (IBBR), CNR, Via Pietro Castellino 111, 80131 Napoli, Italy; Department of Marine Biotechnology, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Napoli, Italy
| | - Daniela Coppola
- Institute of Biosciences and BioResources (IBBR), CNR, Via Pietro Castellino 111, 80131 Napoli, Italy; Department of Marine Biotechnology, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Napoli, Italy
| | - Guido di Prisco
- Institute of Biosciences and BioResources (IBBR), CNR, Via Pietro Castellino 111, 80131 Napoli, Italy
| | - H William Detrich
- Department of Marine and Environmental Sciences, Northeastern University Marine Science Center, Nahant, MA 01908, USA
| | - Cinzia Verde
- Institute of Biosciences and BioResources (IBBR), CNR, Via Pietro Castellino 111, 80131 Napoli, Italy; Department of Marine Biotechnology, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Napoli, Italy.
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30
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Durgin BG, Hahn SA, Schmidt HM, Miller MP, Hafeez N, Mathar I, Freitag D, Sandner P, Straub AC. Loss of smooth muscle CYB5R3 amplifies angiotensin II-induced hypertension by increasing sGC heme oxidation. JCI Insight 2019; 4:129183. [PMID: 31487266 DOI: 10.1172/jci.insight.129183] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Accepted: 08/31/2019] [Indexed: 12/28/2022] Open
Abstract
Nitric oxide regulates BP by binding the reduced heme iron (Fe2+) in soluble guanylyl cyclase (sGC) and relaxing vascular smooth muscle cells (SMCs). We previously showed that sGC heme iron reduction (Fe3+ → Fe2+) is modulated by cytochrome b5 reductase 3 (CYB5R3). However, the in vivo role of SMC CYB5R3 in BP regulation remains elusive. Here, we generated conditional smooth muscle cell-specific Cyb5r3 KO mice (SMC CYB5R3-KO) to test if SMC CYB5R3 loss affects systemic BP in normotension and hypertension via regulation of the sGC redox state. SMC CYB5R3-KO mice exhibited a 5.84-mmHg increase in BP and impaired acetylcholine-induced vasodilation in mesenteric arteries compared with controls. To drive sGC oxidation and elevate BP, we infused mice with angiotensin II. We found that SMC CYB5R3-KO mice exhibited a 14.75-mmHg BP increase, and mesenteric arteries had diminished nitric oxide-dependent vasodilation but increased responsiveness to sGC heme-independent activator BAY 58-2667 over controls. Furthermore, acute injection of BAY 58-2667 in angiotensin II-treated SMC CYB5R3-KO mice showed greater BP reduction compared with controls. Together, these data provide the first in vivo evidence to our knowledge that SMC CYB5R3 is an sGC heme reductase in resistance arteries and provides resilience against systemic hypertension development.
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Affiliation(s)
| | - Scott A Hahn
- Heart, Lung, Blood and Vascular Medicine Institute, and
| | - Heidi M Schmidt
- Heart, Lung, Blood and Vascular Medicine Institute, and.,Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | | | - Neha Hafeez
- Heart, Lung, Blood and Vascular Medicine Institute, and
| | | | | | - Peter Sandner
- Bayer AG, Wuppertal, Germany.,Department of Pharmacology, Hannover Medical School, Hannover, Germany
| | - Adam C Straub
- Heart, Lung, Blood and Vascular Medicine Institute, and.,Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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31
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Amdahl MB, Petersen EE, Bocian K, Kaliszuk SJ, DeMartino AW, Tiwari S, Sparacino-Watkins CE, Corti P, Rose JJ, Gladwin MT, Fago A, Tejero J. The Zebrafish Cytochrome b5/Cytochrome b5 Reductase/NADH System Efficiently Reduces Cytoglobins 1 and 2: Conserved Activity of Cytochrome b5/Cytochrome b5 Reductases during Vertebrate Evolution. Biochemistry 2019; 58:3212-3223. [PMID: 31257865 DOI: 10.1021/acs.biochem.9b00406] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Cytoglobin is a heme protein evolutionarily related to hemoglobin and myoglobin. Cytoglobin is expressed ubiquitously in mammalian tissues; however, its physiological functions are yet unclear. Phylogenetic analyses indicate that the cytoglobin gene is highly conserved in vertebrate clades, from fish to reptiles, amphibians, birds, and mammals. Most proposed roles for cytoglobin require the maintenance of a pool of reduced cytoglobin (FeII). We have shown previously that the human cytochrome b5/cytochrome b5 reductase system, considered a quintessential hemoglobin/myoglobin reductant, can reduce human and zebrafish cytoglobins ≤250-fold faster than human hemoglobin or myoglobin. It was unclear whether this reduction of zebrafish cytoglobins by mammalian proteins indicates a conserved pathway through vertebrate evolution. Here, we report the reduction of zebrafish cytoglobins 1 and 2 by the zebrafish cytochrome b5 reductase and the two zebrafish cytochrome b5 isoforms. In addition, the reducing system also supports reduction of Globin X, a conserved globin in fish and amphibians. Indeed, the zebrafish reducing system can maintain a fully reduced pool for both cytoglobins, and both cytochrome b5 isoforms can support this process. We determined the P50 for oxygen to be 0.5 Torr for cytoglobin 1 and 4.4 Torr for cytoglobin 2 at 25 °C. Thus, even at low oxygen tensions, the reduced cytoglobins may exist in a predominant oxygen-bound form. Under these conditions, the cytochrome b5/cytochrome b5 reductase system can support a conserved role for cytoglobins through evolution, providing electrons for redox signaling reactions such as nitric oxide dioxygenation, nitrite reduction, and phospholipid oxidation.
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Affiliation(s)
- Matthew B Amdahl
- Heart, Lung, Blood, and Vascular Medicine Institute , University of Pittsburgh , Pittsburgh , Pennsylvania 15261 , United States.,Department of Bioengineering , University of Pittsburgh , Pittsburgh , Pennsylvania 15261 , United States
| | - Elin E Petersen
- Department of Bioscience , Aarhus University , DK-8000 Aarhus C, Denmark
| | - Kaitlin Bocian
- Heart, Lung, Blood, and Vascular Medicine Institute , University of Pittsburgh , Pittsburgh , Pennsylvania 15261 , United States
| | - Stefan J Kaliszuk
- Heart, Lung, Blood, and Vascular Medicine Institute , University of Pittsburgh , Pittsburgh , Pennsylvania 15261 , United States
| | - Anthony W DeMartino
- Heart, Lung, Blood, and Vascular Medicine Institute , University of Pittsburgh , Pittsburgh , Pennsylvania 15261 , United States
| | - Sagarika Tiwari
- Heart, Lung, Blood, and Vascular Medicine Institute , University of Pittsburgh , Pittsburgh , Pennsylvania 15261 , United States
| | - Courtney E Sparacino-Watkins
- Heart, Lung, Blood, and Vascular Medicine Institute , University of Pittsburgh , Pittsburgh , Pennsylvania 15261 , United States
| | - Paola Corti
- Heart, Lung, Blood, and Vascular Medicine Institute , University of Pittsburgh , Pittsburgh , Pennsylvania 15261 , United States
| | - Jason J Rose
- Heart, Lung, Blood, and Vascular Medicine Institute , University of Pittsburgh , Pittsburgh , Pennsylvania 15261 , United States.,Department of Bioengineering , University of Pittsburgh , Pittsburgh , Pennsylvania 15261 , United States.,Division of Pulmonary, Allergy and Critical Care Medicine , University of Pittsburgh , Pittsburgh , Pennsylvania 15261 , United States
| | - Mark T Gladwin
- Heart, Lung, Blood, and Vascular Medicine Institute , University of Pittsburgh , Pittsburgh , Pennsylvania 15261 , United States.,Department of Bioengineering , University of Pittsburgh , Pittsburgh , Pennsylvania 15261 , United States.,Division of Pulmonary, Allergy and Critical Care Medicine , University of Pittsburgh , Pittsburgh , Pennsylvania 15261 , United States
| | - Angela Fago
- Department of Bioscience , Aarhus University , DK-8000 Aarhus C, Denmark
| | - Jesús Tejero
- Heart, Lung, Blood, and Vascular Medicine Institute , University of Pittsburgh , Pittsburgh , Pennsylvania 15261 , United States.,Department of Bioengineering , University of Pittsburgh , Pittsburgh , Pennsylvania 15261 , United States.,Division of Pulmonary, Allergy and Critical Care Medicine , University of Pittsburgh , Pittsburgh , Pennsylvania 15261 , United States.,Department of Pharmacology and Chemical Biology , University of Pittsburgh , Pittsburgh , Pennsylvania 15261 , United States
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32
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Amdahl MB, DeMartino AW, Tejero J, Gladwin MT. Cytoglobin at the Crossroads of Vascular Remodeling. Arterioscler Thromb Vasc Biol 2019; 37:1803-1805. [PMID: 28954806 DOI: 10.1161/atvbaha.117.310058] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Matthew B Amdahl
- From the Heart, Lung, Blood, and Vascular Medicine Institute, Department of Medicine (M.B.A., A.W.D., J.T., M.T.G.), Department of Bioengineering (M.B.A.), and Division of Pulmonary, Allergy, and Critical Care Medicine (A.W.D., J.T., M.T.G.), University of Pittsburgh, PA
| | - Anthony W DeMartino
- From the Heart, Lung, Blood, and Vascular Medicine Institute, Department of Medicine (M.B.A., A.W.D., J.T., M.T.G.), Department of Bioengineering (M.B.A.), and Division of Pulmonary, Allergy, and Critical Care Medicine (A.W.D., J.T., M.T.G.), University of Pittsburgh, PA
| | - Jesús Tejero
- From the Heart, Lung, Blood, and Vascular Medicine Institute, Department of Medicine (M.B.A., A.W.D., J.T., M.T.G.), Department of Bioengineering (M.B.A.), and Division of Pulmonary, Allergy, and Critical Care Medicine (A.W.D., J.T., M.T.G.), University of Pittsburgh, PA
| | - Mark T Gladwin
- From the Heart, Lung, Blood, and Vascular Medicine Institute, Department of Medicine (M.B.A., A.W.D., J.T., M.T.G.), Department of Bioengineering (M.B.A.), and Division of Pulmonary, Allergy, and Critical Care Medicine (A.W.D., J.T., M.T.G.), University of Pittsburgh, PA.
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33
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Tejero J, Shiva S, Gladwin MT. Sources of Vascular Nitric Oxide and Reactive Oxygen Species and Their Regulation. Physiol Rev 2019; 99:311-379. [PMID: 30379623 DOI: 10.1152/physrev.00036.2017] [Citation(s) in RCA: 280] [Impact Index Per Article: 56.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Nitric oxide (NO) is a small free radical with critical signaling roles in physiology and pathophysiology. The generation of sufficient NO levels to regulate the resistance of the blood vessels and hence the maintenance of adequate blood flow is critical to the healthy performance of the vasculature. A novel paradigm indicates that classical NO synthesis by dedicated NO synthases is supplemented by nitrite reduction pathways under hypoxia. At the same time, reactive oxygen species (ROS), which include superoxide and hydrogen peroxide, are produced in the vascular system for signaling purposes, as effectors of the immune response, or as byproducts of cellular metabolism. NO and ROS can be generated by distinct enzymes or by the same enzyme through alternate reduction and oxidation processes. The latter oxidoreductase systems include NO synthases, molybdopterin enzymes, and hemoglobins, which can form superoxide by reduction of molecular oxygen or NO by reduction of inorganic nitrite. Enzymatic uncoupling, changes in oxygen tension, and the concentration of coenzymes and reductants can modulate the NO/ROS production from these oxidoreductases and determine the redox balance in health and disease. The dysregulation of the mechanisms involved in the generation of NO and ROS is an important cause of cardiovascular disease and target for therapy. In this review we will present the biology of NO and ROS in the cardiovascular system, with special emphasis on their routes of formation and regulation, as well as the therapeutic challenges and opportunities for the management of NO and ROS in cardiovascular disease.
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Affiliation(s)
- Jesús Tejero
- Pittsburgh Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh , Pittsburgh, Pennsylvania ; Pulmonary, Allergy and Critical Care Medicine, University of Pittsburgh , Pittsburgh, Pennsylvania ; Department of Pharmacology and Chemical Biology, University of Pittsburgh , Pittsburgh, Pennsylvania ; and Department of Medicine, Center for Metabolism and Mitochondrial Medicine, University of Pittsburgh , Pittsburgh, Pennsylvania
| | - Sruti Shiva
- Pittsburgh Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh , Pittsburgh, Pennsylvania ; Pulmonary, Allergy and Critical Care Medicine, University of Pittsburgh , Pittsburgh, Pennsylvania ; Department of Pharmacology and Chemical Biology, University of Pittsburgh , Pittsburgh, Pennsylvania ; and Department of Medicine, Center for Metabolism and Mitochondrial Medicine, University of Pittsburgh , Pittsburgh, Pennsylvania
| | - Mark T Gladwin
- Pittsburgh Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh , Pittsburgh, Pennsylvania ; Pulmonary, Allergy and Critical Care Medicine, University of Pittsburgh , Pittsburgh, Pennsylvania ; Department of Pharmacology and Chemical Biology, University of Pittsburgh , Pittsburgh, Pennsylvania ; and Department of Medicine, Center for Metabolism and Mitochondrial Medicine, University of Pittsburgh , Pittsburgh, Pennsylvania
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34
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Molecular mechanism of metabolic NAD(P)H-dependent electron-transfer systems: The role of redox cofactors. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2018; 1860:233-258. [PMID: 30419202 DOI: 10.1016/j.bbabio.2018.11.014] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 10/30/2018] [Accepted: 11/07/2018] [Indexed: 12/14/2022]
Abstract
NAD(P)H-dependent electron-transfer (ET) systems require three functional components: a flavin-containing NAD(P)H-dehydrogenase, one-electron carrier and metal-containing redox center. In principle, these ET systems consist of one-, two- and three-components, and the electron flux from pyridine nucleotide cofactors, NADPH or NADH to final electron acceptor follows a linear pathway: NAD(P)H → flavin → one-electron carrier → metal containing redox center. In each step ET is primarily controlled by one- and two-electron midpoint reduction potentials of protein-bound redox cofactors in which the redox-linked conformational changes during the catalytic cycle are required for the domain-domain interactions. These interactions play an effective ET reactions in the multi-component ET systems. The microsomal and mitochondrial cytochrome P450 (cyt P450) ET systems, nitric oxide synthase (NOS) isozymes, cytochrome b5 (cyt b5) ET systems and methionine synthase (MS) ET system include a combination of multi-domain, and their organizations display similarities as well as differences in their components. However, these ET systems are sharing of a similar mechanism. More recent structural information obtained by X-ray and cryo-electron microscopy (cryo-EM) analysis provides more detail for the mechanisms associated with multi-domain ET systems. Therefore, this review summarizes the roles of redox cofactors in the metabolic ET systems on the basis of one-electron redox potentials. In final Section, evolutionary aspects of NAD(P)H-dependent multi-domain ET systems will be discussed.
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35
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Lechauve C, Butcher JT, Freiwan A, Biwer LA, Keith JM, Good ME, Ackerman H, Tillman HS, Kiger L, Isakson BE, Weiss MJ. Endothelial cell α-globin and its molecular chaperone α-hemoglobin-stabilizing protein regulate arteriolar contractility. J Clin Invest 2018; 128:5073-5082. [PMID: 30295646 DOI: 10.1172/jci99933] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 08/21/2018] [Indexed: 12/18/2022] Open
Abstract
Arteriolar endothelial cell-expressed (EC-expressed) α-globin binds endothelial NOS (eNOS) and degrades its enzymatic product, NO, via dioxygenation, thereby lessening the vasodilatory effects of NO on nearby vascular smooth muscle. Although this reaction potentially affects vascular physiology, the mechanisms that regulate α-globin expression and dioxygenase activity in ECs are unknown. Without β-globin, α-globin is unstable and cytotoxic, particularly in its oxidized form, which is generated by dioxygenation and recycled via endogenous reductases. We show that the molecular chaperone α-hemoglobin-stabilizing protein (AHSP) promotes arteriolar α-globin expression in vivo and facilitates its reduction by eNOS. In Ahsp-/- mice, EC α-globin was decreased by 70%. Ahsp-/- and Hba1-/- mice exhibited similar evidence of increased vascular NO signaling, including arteriolar dilation, blunted α1-adrenergic vasoconstriction, and reduced blood pressure. Purified α-globin bound eNOS or AHSP, but not both together. In ECs in culture, eNOS or AHSP enhanced α-globin expression posttranscriptionally. However, only AHSP prevented oxidized α-globin precipitation in solution. Finally, eNOS reduced AHSP-bound α-globin approximately 6-fold faster than did the major erythrocyte hemoglobin reductases (cytochrome B5 reductase plus cytochrome B5). Our data support a model whereby redox-sensitive shuttling of EC α-globin between AHSP and eNOS regulates EC NO degradation and vascular tone.
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Affiliation(s)
- Christophe Lechauve
- Department of Hematology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Joshua T Butcher
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Abdullah Freiwan
- Department of Hematology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Lauren A Biwer
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Julia M Keith
- Department of Hematology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Miranda E Good
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Hans Ackerman
- Laboratory of Malaria and Vector Research, National Institutes of Allergy and Infectious Diseases, Rockville, Maryland, USA
| | - Heather S Tillman
- Department of Pathology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | | | - Brant E Isakson
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Mitchell J Weiss
- Department of Hematology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
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36
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Quinone and nitrofurantoin redox cycling by recombinant cytochrome b5 reductase. Toxicol Appl Pharmacol 2018; 359:102-107. [PMID: 30222979 DOI: 10.1016/j.taap.2018.09.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 09/11/2018] [Accepted: 09/12/2018] [Indexed: 01/05/2023]
Abstract
NADH cytochrome b5 reductase mediates electron transfer from NADH to cytochrome b5 utilizing flavin adenine dinucleotide as a redox cofactor. Reduced cytochrome b5 is an important cofactor in many metabolic reactions including cytochrome P450-mediated xenobiotic metabolism, steroid biosynthesis and fatty acid metabolism, hemoglobin reduction, and methionine and plasmalogen synthesis. Using recombinant human enzyme, we discovered that cytochrome b5 reductase mediates redox cycling of a variety of quinones generating superoxide anion, hydrogen peroxide, and, in the presence of transition metals, hydroxyl radicals. Redox cycling activity was oxygen-dependent and preferentially utilized NADH as a co-substrate; NADH was 5-10 times more active than NADPH in supporting redox cycling. Redox cycling activity was greatest for 9,10-phenanthrenequinone and 1,2-naphthoquinone, followed by 1,4-naphthoquinone and 2-methyl-1,4-naphthoquinone (menadione), nitrofurantoin and 2-hydroxyestradiol. Using menadione as the substrate, quinone redox cycling was found to inhibit reduction of cytochrome b5 by cytochrome b5 reductase, as measured by heme spectral changes in cytochrome b5. Under anaerobic conditions where redox cycling is inhibited, menadione had no effect on the reduction of cytochrome b5. Chemical redox cycling by cytochrome b5 reductase may be important in generating cytotoxic reactive oxygen species in target tissues. This activity, together with the inhibition of cytochrome b5 reduction by redox-active chemicals and consequent deficiencies in available cellular cytochrome b5, are likely to contribute to tissue injury following exposure to quinones and related redox active chemicals.
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Abstract
Erythrocytes regulate vascular function through the modulation of oxygen delivery and the scavenging and generation of nitric oxide (NO). First, hemoglobin inside the red blood cell binds oxygen in the lungs and delivers it to tissues throughout the body in an allosterically regulated process, modulated by oxygen, carbon dioxide and proton concentrations. The vasculature responds to low oxygen tensions through vasodilation, further recruiting blood flow and oxygen carrying erythrocytes. Research has shown multiple mechanisms are at play in this classical hypoxic vasodilatory response, with a potential role of red cell derived vasodilatory molecules, such as nitrite derived nitric oxide and red blood cell ATP, considered in the last 20 years. According to these hypotheses, red blood cells release vasodilatory molecules under low oxygen pressures. Candidate molecules released by erythrocytes and responsible for hypoxic vasodilation are nitric oxide, adenosine triphosphate and S-nitrosothiols. Our research group has characterized the biochemistry and physiological effects of the electron and proton transfer reactions from hemoglobin and other ferrous heme globins with nitrite to form NO. In addition to NO generation from nitrite during deoxygenation, hemoglobin has a high affinity for NO. Scavenging of NO by hemoglobin can cause vasoconstriction, which is greatly enhanced by cell free hemoglobin outside of the red cell. Therefore, compartmentalization of hemoglobin inside red blood cells and localization of red blood cells in the blood stream are important for healthy vascular function. Conditions where erythrocyte lysis leads to cell free hemoglobin or where erythrocytes adhere to the endothelium can result in hypertension and vaso constriction. These studies support a model where hemoglobin serves as an oxido-reductase, inhibiting NO and promoting higher vessel tone when oxygenated and reducing nitrite to form NO and vasodilate when deoxygenated.
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Affiliation(s)
- Christine C Helms
- Physics Department, University of Richmond, Richmond, VA, United States
| | - Mark T Gladwin
- Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, United States.,Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
| | - Daniel B Kim-Shapiro
- Physics Department, Wake Forest University, Winston-Salem, NC, United States.,Translational Science Center, Wake Forest University, Winston-Salem, NC, United States
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38
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Rochon ER, Corti P, Gladwin MT. Hemoglobin α in Pulmonary Endothelium: Ironing Out Nitric Oxide Signaling. Am J Respir Cell Mol Biol 2018; 57:639-641. [PMID: 29192832 DOI: 10.1165/rcmb.2017-0272ed] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Affiliation(s)
- Elizabeth R Rochon
- 1 Pittsburgh Heart, Lung, Blood and Vascular Medicine Institute University of Pittsburgh Pittsburgh, Pennsylvania and
| | - Paola Corti
- 1 Pittsburgh Heart, Lung, Blood and Vascular Medicine Institute University of Pittsburgh Pittsburgh, Pennsylvania and
| | - Mark T Gladwin
- 1 Pittsburgh Heart, Lung, Blood and Vascular Medicine Institute University of Pittsburgh Pittsburgh, Pennsylvania and.,2 Division of Pulmonary, Allergy and Critical Care Medicine University of Pittsburgh Pittsburgh, Pennsylvania
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39
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Strong modulation of nitrite reductase activity of cytoglobin by disulfide bond oxidation: Implications for nitric oxide homeostasis. Nitric Oxide 2018; 72:16-23. [DOI: 10.1016/j.niox.2017.11.004] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 10/18/2017] [Accepted: 11/07/2017] [Indexed: 11/22/2022]
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40
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Hanai S, Tsujino H, Yamashita T, Torii R, Sawai H, Shiro Y, Oohora K, Hayashi T, Uno T. Roles of N- and C-terminal domains in the ligand-binding properties of cytoglobin. J Inorg Biochem 2017; 179:1-9. [PMID: 29149638 DOI: 10.1016/j.jinorgbio.2017.11.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Revised: 11/04/2017] [Accepted: 11/04/2017] [Indexed: 01/12/2023]
Abstract
Cytoglobin (Cygb) is a member of the hexacoordinated globin protein family and is expressed ubiquitously in rat and human tissues. Although Cygb is reportedly upregulated under hypoxic conditions both in vivo and in vitro, suggesting a physiological function to protect cells under hypoxic/ischemic conditions by scavenging reactive oxygen species or by signal transduction, the mechanisms associated with this function have not been fully elucidated. Recent studies comparing Cygbs among several species suggest that mammalian Cygbs show a distinctly longer C-terminal domain potentially involved in unique physiological functions. In this study, we prepared human Cygb mutants (ΔC, ΔN, and ΔNC) with either one or both terminal domains truncated and investigated the enzymatic functions and structural features by spectroscopic methods. Evaluation of the superoxide-scavenging activity between Cygb variants showed that the ΔC and ΔNC mutants exhibited slightly higher activity involving superoxide scavenging as compared with wild-type Cygb. Subsequent experiments involving ligand titration, flash photolysis, and resonance Raman spectroscopic studies suggested that the truncation of the C- and N-terminal domains resulted in less effective to dissociation constants and binding rates for carbon monoxide, respectively. Furthermore, structural stability was assessed by guanidine hydrochloride and revealed that the C-terminal domain might play a vital role in improving structure, whereas the N-terminal domain did not exert a similar effect. These findings indicated that long terminal domains could be important not only in regulating enzymatic activity but also for structural stability, and that the domains might be relevant to other hypothesized physiological functions for Cygb.
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Affiliation(s)
- Shumpei Hanai
- Graduate School of Pharmaceutical Sciences, Osaka University, Osaka, Japan
| | - Hirofumi Tsujino
- Graduate School of Pharmaceutical Sciences, Osaka University, Osaka, Japan
| | - Taku Yamashita
- School of Pharmacy and Pharmaceutical Sciences, Mukogawa Women's University, Hyogo, Japan.
| | - Ryo Torii
- Graduate School of Pharmaceutical Sciences, Osaka University, Osaka, Japan
| | - Hitomi Sawai
- Graduate School of Life Science, University of Hyogo, Hyogo, Japan
| | | | - Koji Oohora
- Department of Applied Chemistry, Osaka University, Osaka, Japan
| | - Takashi Hayashi
- Department of Applied Chemistry, Osaka University, Osaka, Japan
| | - Tadayuki Uno
- Graduate School of Pharmaceutical Sciences, Osaka University, Osaka, Japan
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41
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Gell DA. Structure and function of haemoglobins. Blood Cells Mol Dis 2017; 70:13-42. [PMID: 29126700 DOI: 10.1016/j.bcmd.2017.10.006] [Citation(s) in RCA: 115] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2017] [Revised: 10/29/2017] [Accepted: 10/30/2017] [Indexed: 12/18/2022]
Abstract
Haemoglobin (Hb) is widely known as the iron-containing protein in blood that is essential for O2 transport in mammals. Less widely recognised is that erythrocyte Hb belongs to a large family of Hb proteins with members distributed across all three domains of life-bacteria, archaea and eukaryotes. This review, aimed chiefly at researchers new to the field, attempts a broad overview of the diversity, and common features, in Hb structure and function. Topics include structural and functional classification of Hbs; principles of O2 binding affinity and selectivity between O2/NO/CO and other small ligands; hexacoordinate (containing bis-imidazole coordinated haem) Hbs; bacterial truncated Hbs; flavohaemoglobins; enzymatic reactions of Hbs with bioactive gases, particularly NO, and protection from nitrosative stress; and, sensor Hbs. A final section sketches the evolution of work on the structural basis for allosteric O2 binding by mammalian RBC Hb, including the development of newer kinetic models. Where possible, reference to historical works is included, in order to provide context for current advances in Hb research.
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Affiliation(s)
- David A Gell
- School of Medicine, University of Tasmania, TAS 7000, Australia.
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42
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Samhan-Arias AK, Almeida RM, Ramos S, Cordas CM, Moura I, Gutierrez-Merino C, Moura JJG. Topography of human cytochrome b 5/cytochrome b 5 reductase interacting domain and redox alterations upon complex formation. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2017; 1859:78-87. [PMID: 29111436 DOI: 10.1016/j.bbabio.2017.10.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 10/23/2017] [Accepted: 10/27/2017] [Indexed: 10/18/2022]
Abstract
Cytochrome b5 is the main electron acceptor of cytochrome b5 reductase. The interacting domain between both human proteins has been unidentified up to date and very little is known about its redox properties modulation upon complex formation. In this article, we characterized the protein/protein interacting interface by solution NMR and molecular docking. In addition, upon complex formation, we measured an increase of cytochrome b5 reductase flavin autofluorescence that was dependent upon the presence of cytochrome b5. Data analysis of these results allowed us to calculate a dissociation constant value between proteins of 0.5±0.1μM and a 1:1 stoichiometry for the complex formation. In addition, a 30mV negative shift of cytochrome b5 reductase redox potential in presence of cytochrome b5 was also measured. These experiments suggest that the FAD group of cytochrome b5 reductase increase its solvent exposition upon complex formation promoting an efficient electron transfer between the proteins.
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Affiliation(s)
- Alejandro K Samhan-Arias
- UCIBIO, REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, NOVA, 2829-516 Caparica, Portugal.
| | - Rui M Almeida
- UCIBIO, REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, NOVA, 2829-516 Caparica, Portugal
| | - Susana Ramos
- UCIBIO, REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, NOVA, 2829-516 Caparica, Portugal
| | - Cristina M Cordas
- UCIBIO, REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, NOVA, 2829-516 Caparica, Portugal
| | - Isabel Moura
- UCIBIO, REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, NOVA, 2829-516 Caparica, Portugal
| | - Carlos Gutierrez-Merino
- Department of Biochemistry and Molecular Biology, Faculty of Sciences, Institute of Molecular Pathology Biomarkers, University of Extremadura, 06006 Badajoz, Spain
| | - José J G Moura
- UCIBIO, REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, NOVA, 2829-516 Caparica, Portugal.
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