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Khator K, Parihar S, Jasik J, Shekhawat GS. Nitric oxide in plants: an insight on redox activity and responses toward abiotic stress signaling. PLANT SIGNALING & BEHAVIOR 2024; 19:2298053. [PMID: 38190763 DOI: 10.1080/15592324.2023.2298053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Accepted: 12/16/2023] [Indexed: 01/10/2024]
Abstract
Plants, as sessile organisms, are subjected to diverse abiotic stresses, including salinity, desiccation, metal toxicity, thermal fluctuations, and hypoxia at different phases of plant growth. Plants can activate messenger molecules to initiate a signaling cascade of response toward environmental stresses that results in either cell death or plant acclimation. Nitric oxide (NO) is a small gaseous redox-active molecule that exhibits a plethora of physiological functions in growth, development, flowering, senescence, stomata closure and responses to environmental stresses. It can also facilitate alteration in protein function and reprogram the gene profiling by direct or indirect interaction with different target molecules. The bioactivity of NO can be manifested through different redox-based protein modifications including S-nitrosylation, protein nitration, and metal nitrosylation in plants. Although there has been considerable progress in the role of NO in regulating stress signaling, still the physiological mechanisms regarding the abiotic stress tolerance in plants remain unclear. This review summarizes recent advances in understanding the emerging knowledge regarding NO function in plant tolerance against abiotic stresses. The manuscript also highlighted the importance of NO as an abiotic stress modulator and developed a rational design for crop cultivation under a stress environment.
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Affiliation(s)
- Khushboo Khator
- Plant Biotechnology and Molecular Biology Laboratory, Department of Botany (UGC-CAS) Jai Narain Vyas University, Jodhpur, India
| | - Suman Parihar
- Plant Biotechnology and Molecular Biology Laboratory, Department of Botany (UGC-CAS) Jai Narain Vyas University, Jodhpur, India
| | - Jan Jasik
- Institute of Botany, Plant Science and Biodiversity Centre, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Gyan Singh Shekhawat
- Plant Biotechnology and Molecular Biology Laboratory, Department of Botany (UGC-CAS) Jai Narain Vyas University, Jodhpur, India
- Institute of Botany, Plant Science and Biodiversity Centre, Slovak Academy of Sciences, Bratislava, Slovakia
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Ferdous Z, Beegam S, Zaaba NE, Nemmar A. Exposure to Waterpipe Smoke Disrupts Erythrocyte Homeostasis of BALB/c Mice. BIOLOGY 2024; 13:453. [PMID: 38927333 PMCID: PMC11200634 DOI: 10.3390/biology13060453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2024] [Revised: 06/14/2024] [Accepted: 06/15/2024] [Indexed: 06/28/2024]
Abstract
The prevalence of waterpipe tobacco smoking (WPS) is increasing worldwide and is relatively high among youth and young adults. It has been shown, both experimentally and clinically, that WPS exposure adversely affects the cardiovascular and hematological systems through the generation of oxidative stress and inflammation. Our study aimed to evaluate the impact of WPS exposure on erythrocytes, a major component of the hematological system, of BALB/c mice. Here, we assessed the effect of nose-only WPS exposure for four consecutive weeks on erythrocyte inflammation, oxidative stress, and eryptosis. The duration of the session was 30 min/day, 5 days/week. Control mice were exposed to air. Our results showed that the levels of C-reactive protein, lipid peroxidation (LPO), superoxide dismutase, and total nitric oxide (NO) were significantly increased in the plasma of WPS-exposed mice. The number of erythrocytes and the hematocrit were significantly decreased in WPS-exposed mice compared with the control group. Moreover, there was an increase in the erythrocyte fragility in mice exposed to WPS compared with those exposed to air. The levels of lactate dehydrogenase, LPO, reduced glutathione, catalase, and NO were significantly increased in the red blood cells (RBCs) of WPS-exposed mice. In addition, erythrocytes of the WPS-exposed group showed a significant increase in ATPase activity, Ca2+, annexin V binding, and calpain activity. Taken together, our findings suggest that WPS exposure elevated inflammation and oxidative stress in the plasma and induced hemolysis in vivo. It also caused alterations of RBCs oxidative stress and eryptosis in vitro. Our data confirm the detrimental impact of WPS on erythrocyte physiology.
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Affiliation(s)
- Zannatul Ferdous
- Department of Physiology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain P.O. Box 15551, United Arab Emirates; (Z.F.); (S.B.)
| | - Sumaya Beegam
- Department of Physiology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain P.O. Box 15551, United Arab Emirates; (Z.F.); (S.B.)
| | - Nur E. Zaaba
- Department of Physiology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain P.O. Box 15551, United Arab Emirates; (Z.F.); (S.B.)
| | - Abderrahim Nemmar
- Department of Physiology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain P.O. Box 15551, United Arab Emirates; (Z.F.); (S.B.)
- Zayed Center for Health Sciences, United Arab Emirates University, Al Ain P.O. Box 15551, United Arab Emirates
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Kawabata Y, Fukushige T, Indo HP, Matsumoto KI, Ueno M, Nakanishi I, Chatatikun M, Klangbud WK, Surinkaew S, Tangpong J, Kanekura T, Majima HJ. Hair Follicle Damage after 100 mGy Low-Dose Fractionated X-Ray Irradiation and the Protective Effects of TEMPOL, a Stable Nitroxide Radical, against Radiation. Radiat Res 2024; 201:115-125. [PMID: 38211765 DOI: 10.1667/rade-23-00167.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Accepted: 12/12/2023] [Indexed: 01/13/2024]
Abstract
The effects of long-term low-dose X-ray irradiation on the outer root sheath (ORS) cells of C3H/He mice were investigated. Mice were irradiated with a regime of 100 mGy/day, 5 days/week, for 12 weeks (Group X) and the results obtained were compared to those in a non-irradiated control (Group C). Potential protection against ORS cells damage induced by this exposure was investigated by adding the stable nitroxide radical 4-hydroxyl-2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPOL) at 1 mM to the drinking water of mice (Group X + TEMPOL). The results obtained were compared with Group C and a non-irradiated group treated with TEMPOL (Group C + TEMPOL). After fractionated X-ray irradiation, skin was removed and ORS cells were examined by hematoxylin and eosin staining and electron microscopy for an abnormal nuclear morphology and nuclear condensation changes. Fractionated X-irradiated mice had an increased number of ORS cells with an abnormal nuclear morphology as well as nuclear condensation changes. Sections were also immunohistochemically examined for the presence of TdT-mediated dUTP nick-end labeling (TUNEL), 8-hydroxy-2'-deoxyguanosine (8-OHdG), 4-hydroxynonenal (4-HNE), vascular endothelial growth factor (VEGF), nitrotyrosine, heme oxygenase 1 (HO-1), and protein gene product 9.5 (PGP 9.5). Significant increases were observed in TUNEL, 8-OHdG, and 4-HNE levels in ORS cells from mice in Group X. Electron microscopy also showed irregular shrunken ORS cells in Group X. These changes were prevented by the presence of TEMPOL in the drinking water of the irradiated mice. TEMPOL alone had no significant effects. These results suggest that fractionated doses of radiation induced oxidative damage in ORS cells; however, TEMPOL provided protection against this damage, possibly as a result of the rapid reaction of this nitroxide radical with the reactive oxidants generated by fractionated X-ray irradiation.
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Affiliation(s)
- Yoshihiro Kawabata
- Department of Oncology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890-8544, Japan
| | - Tomoko Fukushige
- Department of Dermatology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890-8544, Japan
| | - Hiroko P Indo
- Department of Oncology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890-8544, Japan
- Amanogawa Galaxy Astronomy Research Center, Kagoshima University Graduate School of and Engineering, Kagoshima 890-0065, Japan
| | - Ken-Ichiro Matsumoto
- Quantitative RedOx Sensing Group, Department of Radiation Regulatory Science Research, National Institute of Radiological Sciences, Quantum Life and Medical Science Directorate, National Institutes for Quantum Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Megumi Ueno
- Quantitative RedOx Sensing Group, Department of Radiation Regulatory Science Research, National Institute of Radiological Sciences, Quantum Life and Medical Science Directorate, National Institutes for Quantum Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Ikuo Nakanishi
- Quantum RedOx Chemistry Team, Institute for Quantum Life Science (iQLS), Quantum Life and Medical Science Directorate, National Institutes for Quantum Science and Technology (QST), 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Moragot Chatatikun
- Biomedical Sciences, School of Allied Health Sciences, School of Allied Health Sciences, Walailak University, Nakhon Si Thammarat 80160, Thailand
- Center of Excellence Research for Melioidosis and Microorganisms, School of Allied Health Sciences, Walailak University, Nakhon Si Thammarat 80160, Thailand
| | - Wiyada Kwanhian Klangbud
- Biomedical Sciences, School of Allied Health Sciences, School of Allied Health Sciences, Walailak University, Nakhon Si Thammarat 80160, Thailand
- Center of Excellence Research for Melioidosis and Microorganisms, School of Allied Health Sciences, Walailak University, Nakhon Si Thammarat 80160, Thailand
| | - Sirirat Surinkaew
- Biomedical Sciences, School of Allied Health Sciences, School of Allied Health Sciences, Walailak University, Nakhon Si Thammarat 80160, Thailand
- Research Excellence Center for Innovation and Health Products (RECIHP), School of Allied Health Sciences, Walailak University, Nakhon Si Thammarat 80160, Thailand
| | - Jitbanjong Tangpong
- Biomedical Sciences, School of Allied Health Sciences, School of Allied Health Sciences, Walailak University, Nakhon Si Thammarat 80160, Thailand
- Research Excellence Center for Innovation and Health Products (RECIHP), School of Allied Health Sciences, Walailak University, Nakhon Si Thammarat 80160, Thailand
| | - Takuro Kanekura
- Department of Dermatology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890-8544, Japan
| | - Hideyuki J Majima
- Department of Oncology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890-8544, Japan
- Amanogawa Galaxy Astronomy Research Center, Kagoshima University Graduate School of and Engineering, Kagoshima 890-0065, Japan
- Center of Excellence Research for Melioidosis and Microorganisms, School of Allied Health Sciences, Walailak University, Nakhon Si Thammarat 80160, Thailand
- Research Excellence Center for Innovation and Health Products (RECIHP), School of Allied Health Sciences, Walailak University, Nakhon Si Thammarat 80160, Thailand
- Department of Space Environmental Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890-8544, Japan
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Sadowska-Bartosz I, Bartosz G. The Cellular and Organismal Effects of Nitroxides and Nitroxide-Containing Nanoparticles. Int J Mol Sci 2024; 25:1446. [PMID: 38338725 PMCID: PMC10855878 DOI: 10.3390/ijms25031446] [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: 12/21/2023] [Revised: 01/21/2024] [Accepted: 01/22/2024] [Indexed: 02/12/2024] Open
Abstract
Nitroxides are stable free radicals that have antioxidant properties. They react with many types of radicals, including alkyl and peroxyl radicals. They act as mimics of superoxide dismutase and stimulate the catalase activity of hemoproteins. In some situations, they may exhibit pro-oxidant activity, mainly due to the formation of oxoammonium cations as products of their oxidation. In this review, the cellular effects of nitroxides and their effects in animal experiments and clinical trials are discussed, including the beneficial effects in various pathological situations involving oxidative stress, protective effects against UV and ionizing radiation, and prolongation of the life span of cancer-prone mice. Nitroxides were used as active components of various types of nanoparticles. The application of these nanoparticles in cellular and animal experiments is also discussed.
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Affiliation(s)
- Izabela Sadowska-Bartosz
- Laboratory of Analytical Biochemistry, Institute of Food Technology and Nutrition, College of Natural Sciences, University of Rzeszow, 4 Zelwerowicza Street, 35-601 Rzeszow, Poland;
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Rayner CL, Bottle SE, Martyn AP, Barnett NL. Preserving Retinal Structure and Function with the Novel Nitroxide Antioxidant, DCTEIO. Neurochem Res 2023; 48:3402-3419. [PMID: 37450210 PMCID: PMC10514139 DOI: 10.1007/s11064-023-03978-w] [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: 02/16/2023] [Revised: 06/16/2023] [Accepted: 06/27/2023] [Indexed: 07/18/2023]
Abstract
Oxidative stress is a major contributor to progressive neurodegenerative disease and may be a key target for the development of novel preventative and therapeutic strategies. Nitroxides have been successfully utilised to study changes in redox status (biological probes) and modulate radical-induced oxidative stress. This study investigates the efficacy of DCTEIO (5,6-dicarboxy-1,1,3,3-tetraethyllisoindolin-2-yloxyl), a stable, kinetically-persistent, nitroxide-based antioxidant, as a retinal neuroprotectant. The preservation of retinal function following an acute ischaemic/reperfusion (I/R) insult in the presence of DCTEIO was quantified by electroretinography (ERG). Inflammatory responses in retinal glia were analysed by GFAP and IBA-1 immunohistochemistry, and retinal integrity assessed by histology. A nitroxide probe combined with flow cytometry provided a rapid technique to assess oxidative stress and the mitigation offered by antioxidant compounds in cultured 661W photoreceptor cells. DCTEIO protected the retina from I/R-induced damage, maintaining retinal function. Histological analysis showed preservation of retinal integrity with reduced disruption and disorganisation of the inner and outer nuclear layers. I/R injury upregulated GFAP expression, indicative of retinal stress, which was significantly blunted by DCTEIO. The number of 'activated' microglia, particularly in the outer retina, in response to cellular stress was also significantly reduced by DCTEIO, potentially suggesting reduced inflammasome activation and cell death. DCTEIO mitigated oxidative stress in 661W retinal cell cultures, in a dose-dependent fashion. Together these findings demonstrate the potential of DCTEIO as a neuroprotective therapeutic for degenerative diseases of the CNS that involve an ROS-mediated component, including those of the retina e.g. age-related macular degeneration and glaucoma.
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Affiliation(s)
- Cassie L Rayner
- Clem Jones Centre for Regenerative Medicine, Faculty of Health Sciences and Medicine, Bond University, 14 University Drive, Robina, Gold Coast, QLD, 4226, Australia
- Queensland Eye Institute, South Brisbane, QLD, 4101, Australia
| | - Steven E Bottle
- School of Physical and Chemical Sciences, Queensland University of Technology, Brisbane, QLD, 4000, Australia
| | - Alexander P Martyn
- School of Physical and Chemical Sciences, Queensland University of Technology, Brisbane, QLD, 4000, Australia
- Cancer and Ageing Research Program (CARP), Princess Alexandra Hospital, Brisbane, QLD, 4102, Australia
| | - Nigel L Barnett
- Clem Jones Centre for Regenerative Medicine, Faculty of Health Sciences and Medicine, Bond University, 14 University Drive, Robina, Gold Coast, QLD, 4226, Australia.
- Queensland Eye Institute, South Brisbane, QLD, 4101, Australia.
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6
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Truzzi DR, Medeiros NM, Augusto O, Ford PC. Dinitrosyl Iron Complexes (DNICs). From Spontaneous Assembly to Biological Roles. Inorg Chem 2021; 60:15835-15845. [PMID: 34014639 DOI: 10.1021/acs.inorgchem.1c00823] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Dinitrosyl iron complexes (DNICs) are spontaneously and rapidly generated in cells. Their assembly requires nitric oxide (NO), biothiols, and nonheme iron, either labile iron or iron-sulfur clusters. Despite ubiquitous detection by electron paramagnetic resonance in NO-producing cells, the DNIC's chemical biology remains only partially understood. In this Forum Article, we address the reaction mechanisms for endogenous DNIC formation, with a focus on a labile iron pool as the iron source. The capability of DNICs to promote S-nitrosation is discussed in terms of S-nitrosothiol generation associated with the formation and chemical reactivity of DNICs. We also highlight how elucidation of the chemical reactivity and the dynamics of DNICs combined with the development of detection/quantification methods can provide further information regarding their participation in physiological and pathological processes.
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Affiliation(s)
- Daniela R Truzzi
- Departamento de Bioquímica, Instituto de Química de São Paulo, Universidade de São Paulo, Caixa Postal 26077, CEP05513-970 São Paulo, São Paulo, Brazil
| | - Nathalia M Medeiros
- Departamento de Bioquímica, Instituto de Química de São Paulo, Universidade de São Paulo, Caixa Postal 26077, CEP05513-970 São Paulo, São Paulo, Brazil
| | - Ohara Augusto
- Departamento de Bioquímica, Instituto de Química de São Paulo, Universidade de São Paulo, Caixa Postal 26077, CEP05513-970 São Paulo, São Paulo, Brazil
| | - Peter C Ford
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, California 93106-9510, United States
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Folkes LK, Bartesaghi S, Trujillo M, Wardman P, Radi R. The effects of nitric oxide or oxygen on the stable products formed from the tyrosine phenoxyl radical. Free Radic Res 2021; 55:141-153. [PMID: 33399021 DOI: 10.1080/10715762.2020.1870684] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Tyrosine is a critical component of many proteins and can be the subject of oxidative posttranslational modifications. Furthermore, the oxidation of tyrosine residues to phenoxyl radicals, sometimes quite stable, is essential for some enzymatic functions. The lifetime and fate of tyrosine phenoxyl radicals in biological systems are largely driven by the availability and proximity of oxidants and reductants. Tyrosine phenoxyl radicals have extremely low reactivity with molecular oxygen whereas reactions with nitric oxide are diffusion controlled. This is in contrast to equivalent reactions with tryptophanyl and cysteinyl radicals where reactions with oxygen are much faster. Despite, the quite disparate apparent reactivity of tyrosine phenoxyl radicals with oxygen and nitric oxide being known, the products of the reactions are not well established. Changes in the levels from expected basal concentrations of stable products resulting from tyrosine phenoxyl radicals, for example naturally occurring 3,3'-dityrosine, 3-nitrotyrosine, and 3-hydroxytyrosine, can be indicative of oxidative and/or nitrosative stress. Using the radiolytic generation of specific oxidizing radicals to form tyrosine phenoxyl radicals in an aqueous solution at a known rate, we have compared the products in the absence and presence of nitric oxide or oxygen. Possible reactions of the phenoxyl radicals with oxygen remain unclear although we show evidence for a small decrease in the yield of dityrosine and loss of tyrosine in the presence of 20% oxygen. Low concentrations of nitric oxide in anoxic conditions react with tyrosine phenoxyl radicals, by what is most probably through the formation of an unstable intermediate, regenerating tyrosine and forming nitrite.
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Affiliation(s)
- Lisa K Folkes
- MRC Oxford Institute for Radiation Oncology and Biology, Department of Oncology, University of Oxford, Oxford, UK
| | - Silvina Bartesaghi
- Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay.,Centro de Investigaciones Biomédicas (CEINBIO), Universidad de la República, Montevideo, Uruguay
| | - Madia Trujillo
- Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay.,Centro de Investigaciones Biomédicas (CEINBIO), Universidad de la República, Montevideo, Uruguay
| | - Peter Wardman
- MRC Oxford Institute for Radiation Oncology and Biology, Department of Oncology, University of Oxford, Oxford, UK
| | - Rafael Radi
- Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay.,Centro de Investigaciones Biomédicas (CEINBIO), Universidad de la República, Montevideo, Uruguay
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Wardman P. Radiotherapy Using High-Intensity Pulsed Radiation Beams (FLASH): A Radiation-Chemical Perspective. Radiat Res 2020; 194:607-617. [DOI: 10.1667/rade-19-00016] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 03/31/2020] [Indexed: 11/03/2022]
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Verderosa AD, Dhouib R, Fairfull-Smith KE, Totsika M. Nitroxide Functionalized Antibiotics Are Promising Eradication Agents against Staphylococcus aureus Biofilms. Antimicrob Agents Chemother 2019; 64:e01685-19. [PMID: 31636066 PMCID: PMC7187575 DOI: 10.1128/aac.01685-19] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Accepted: 10/09/2019] [Indexed: 01/10/2023] Open
Abstract
Treatment of biofilm-related Staphylococcus aureus infections represents an important medical challenge worldwide, as biofilms, even those involving drug-susceptible S. aureus strains, are highly refractory to conventional antibiotic therapy. Nitroxides were recently shown to induce the dispersal of Gram-negative biofilms in vitro, but their action against Gram-positive bacterial biofilms remains unknown. Here, we demonstrate that the biofilm dispersal activity of nitroxides extends to S. aureus, a clinically important Gram-positive pathogen. Coadministration of the nitroxide CTEMPO (4-carboxy-2,2,6,6-tetramethylpiperidin-1-yloxyl) with ciprofloxacin significantly improved the biofilm eradication activity of the antibiotic against S. aureus Moreover, covalently linking the nitroxide to the antibiotic moiety further reduced the ciprofloxacin minimal biofilm eradication concentration. Microscopy analysis revealed that fluorescent nitroxide-antibiotic hybrids could penetrate S. aureus biofilms and enter cells localized at the surface and base of the biofilm structure. No toxicity to human cells was observed for the nitroxide CTEMPO or the nitroxide-antibiotic hybrids. Taken together, our results show that nitroxides can mediate the dispersal of Gram-positive biofilms and that dual-acting biofilm eradication antibiotics may provide broad-spectrum therapies for the treatment of biofilm-related infections.
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Affiliation(s)
- Anthony D Verderosa
- School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology, Brisbane, Queensland, Australia
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
- School of Biomedical Sciences, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Rabeb Dhouib
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
- School of Biomedical Sciences, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Kathryn E Fairfull-Smith
- School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Makrina Totsika
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
- School of Biomedical Sciences, Queensland University of Technology, Brisbane, Queensland, Australia
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Maimon E, Samuni A, Goldstein S. Mechanistic insight into the catalytic inhibition by nitroxides of tyrosine oxidation and nitration. Biochim Biophys Acta Gen Subj 2019; 1863:129403. [PMID: 31356821 DOI: 10.1016/j.bbagen.2019.07.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 07/03/2019] [Accepted: 07/24/2019] [Indexed: 12/20/2022]
Abstract
BACKGROUND Nitroxide antioxidants (RNO•) protect from injuries associated with oxidative stress. Tyrosine residues in proteins are major targets for oxidizing species giving rise to irreversible cross-linking and protein nitration, but the mechanisms underlying the protective activity of RNO• on these processes are not sufficiently clear. METHODS Tyrosine oxidation by the oxoammonium cation (RN+=O) was studied by following the kinetics of RNO• formation using EPR spectroscopy. Tyrosine oxidation and nitration were investigated using the peroxidase/H2O2 system without and with nitrite. The inhibitory effect of RNO• on these processes was studied by following the kinetics of the evolved O2 and accumulation of tyrosine oxidation and nitration products. RESULTS Tyrosine ion is readily oxidized by RN+=O, and the equilibrium constant of this reaction depends on RNO• structure and reduction potential. RNO• catalytically inhibits tyrosine oxidation and nitration since it scavenges both tyrosyl and •NO2 radicals while recycling through RN+=O reduction by H2O2, tyrosine and nitrite. The inhibitory effect of nitroxide on tyrosine oxidation and nitration increases as its reduction potential decreases where the 6-membered ring nitroxides are better catalysts than the 5-membered ones. CONCLUSIONS Nitroxides catalytically inhibit tyrosine oxidation and nitration. The proposed reaction mechanism adequately fits the results explaining the dependence of the nitroxide inhibitory effect on its reduction potential and on the concentrations of the reducing species present in the system. GENERAL SIGNIFICANCE Nitroxides protect against both oxidative and nitrative damage. The proposed reaction mechanism further emphasizes the role of the reducing environment to the efficacy of these catalysts.
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Affiliation(s)
- Eric Maimon
- Nuclear Research Centre Negev and Chemistry Department, Ben-Gurion University, Beer-Sheva 84105, Israel
| | - Amram Samuni
- Institute of Medical Research, Israel-Canada Medical School, The Hebrew University of Jerusalem, Jerusalem 91120, Israel
| | - Sara Goldstein
- Institute of Chemistry, The Accelerator Laboratory, the Hebrew University of Jerusalem, Jerusalem 91904, Israel.
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Yadav M, Singh AS, Agrahari AK, Mishra N, Tiwari VK. Silicon Industry Waste Polymethylhydrosiloxane-Mediated Benzotriazole Ring Cleavage: A Practical and Green Synthesis of Diverse Benzothiazoles. ACS OMEGA 2019; 4:6681-6689. [PMID: 31459794 PMCID: PMC6648665 DOI: 10.1021/acsomega.9b00343] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Accepted: 03/29/2019] [Indexed: 06/10/2023]
Abstract
A green modification has been introduced to the synthesis of benzothiazoles by using polymethylhydrosiloxane (PMHS) for successive steps of benzotriazole ring cleavage and cyclization, an approach which was previously developed in our lab by the use of n-Bu3SnH. The use of the silicone industry byproduct PMHS makes this protocol a cost-effective and nontoxic one and thus may be considered for the industrial importance.
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12
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Pedron FN, Bartesaghi S, Estrin DA, Radi R, Zeida A. A computational investigation of the reactions of tyrosyl, tryptophanyl, and cysteinyl radicals with nitric oxide and molecular oxygen. Free Radic Res 2018; 53:18-25. [DOI: 10.1080/10715762.2018.1541322] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Federico N. Pedron
- Departamento de Química Inorgánica, Analítica y Química-Física and INQUIMAE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires Ciudad Universitaria, Buenos Aires, Argentina
| | - Silvina Bartesaghi
- Departamento de Bioquímica, Universidad de la República, Montevideo, Uruguay
- Center for Free Radical and Biomedical Research, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Darío A. Estrin
- Departamento de Química Inorgánica, Analítica y Química-Física and INQUIMAE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires Ciudad Universitaria, Buenos Aires, Argentina
| | - Rafael Radi
- Departamento de Bioquímica, Universidad de la República, Montevideo, Uruguay
- Center for Free Radical and Biomedical Research, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Ari Zeida
- Departamento de Química Inorgánica, Analítica y Química-Física and INQUIMAE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires Ciudad Universitaria, Buenos Aires, Argentina
- Departamento de Bioquímica, Universidad de la República, Montevideo, Uruguay
- Center for Free Radical and Biomedical Research, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
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13
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Chong KL, Chalmers BA, Cullen JK, Kaur A, Kolanowski JL, Morrow BJ, Fairfull-Smith KE, Lavin MJ, Barnett NL, New EJ, Murphy MP, Bottle SE. Pro-fluorescent mitochondria-targeted real-time responsive redox probes synthesised from carboxy isoindoline nitroxides: Sensitive probes of mitochondrial redox status in cells. Free Radic Biol Med 2018; 128:97-110. [PMID: 29567391 DOI: 10.1016/j.freeradbiomed.2018.03.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 02/12/2018] [Accepted: 03/06/2018] [Indexed: 11/28/2022]
Abstract
Here we describe new fluorescent probes based on fluorescein and rhodamine that provide reversible, real-time insight into cellular redox status. The new probes incorporate bio-imaging relevant fluorophores derived from fluorescein and rhodamine linked with stable nitroxide radicals such that they cannot be cleaved, either spontaneously or enzymatically by cellular processes. Overall fluorescence emission is determined by reversible reduction and oxidation, hence the steady state emission intensity reflects the balance between redox potentials of critical redox couples within the cell. The permanent positive charge on the rhodamine-based probes leads to their rapid localisation within mitochondria in cells. Reduction and oxidation also leads to marked changes in the fluorophore lifetime, enabling monitoring by fluorescence lifetime imaging microscopy. Finally, we demonstrate that administration of a methyl ester version of the rhodamine-based probe can be used at concentrations as low as 5 nM to generate a readily detected response to redox stress within cells as analysed by flow cytometry.
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Affiliation(s)
- Kok Leong Chong
- ARC Centre of Excellence for Free Radical Chemistry, Faculty of Science and Engineering, Queensland University of Technology (QUT), Brisbane, Queensland, Australia
| | - Benjamin A Chalmers
- ARC Centre of Excellence for Free Radical Chemistry, Faculty of Science and Engineering, Queensland University of Technology (QUT), Brisbane, Queensland, Australia
| | - Jason K Cullen
- Cell and Molecular Biology, Queensland Institute of Medical Research, Brisbane, Australia
| | - Amandeep Kaur
- School of Chemistry, University of Sydney, Australia
| | | | - Benjamin J Morrow
- ARC Centre of Excellence for Free Radical Chemistry, Faculty of Science and Engineering, Queensland University of Technology (QUT), Brisbane, Queensland, Australia
| | - Kathryn E Fairfull-Smith
- ARC Centre of Excellence for Free Radical Chemistry, Faculty of Science and Engineering, Queensland University of Technology (QUT), Brisbane, Queensland, Australia
| | - Martin J Lavin
- Cell and Molecular Biology, Queensland Institute of Medical Research, Brisbane, Australia; University of Queensland, Centre for Clinical Research, Brisbane, Australia
| | | | | | - Michael P Murphy
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge CB2 0XY, UK
| | - Steven E Bottle
- ARC Centre of Excellence for Free Radical Chemistry, Faculty of Science and Engineering, Queensland University of Technology (QUT), Brisbane, Queensland, Australia.
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14
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Hansen KA, Blinco JP. Nitroxide radical polymers – a versatile material class for high-tech applications. Polym Chem 2018. [DOI: 10.1039/c7py02001e] [Citation(s) in RCA: 97] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
A comprehensive summary of synthetic strategies for the preparation of nitroxide radical polymer materials and a state-of-the-art perspective on their latest and most exciting applications.
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Affiliation(s)
- Kai-Anders Hansen
- School of Chemistry
- Physics and Mechanical Engineering
- Queensland University of Technology
- Brisbane
- Australia
| | - James P. Blinco
- School of Chemistry
- Physics and Mechanical Engineering
- Queensland University of Technology
- Brisbane
- Australia
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15
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Mogen AB, Carroll RK, James KL, Lima G, Silva D, Culver JA, Petucci C, Shaw LN, Rice KC. Staphylococcus aureus nitric oxide synthase (saNOS) modulates aerobic respiratory metabolism and cell physiology. Mol Microbiol 2017; 105:139-157. [PMID: 28431199 PMCID: PMC5641370 DOI: 10.1111/mmi.13693] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/10/2017] [Indexed: 12/11/2022]
Abstract
Nitric oxide (NO) is generated from arginine and oxygen via NO synthase (NOS). Staphylococcus aureus NOS (saNOS) has previously been shown to affect virulence and resistance to exogenous oxidative stress, yet the exact mechanism is unknown. Herein, a previously undescribed role of saNOS in S. aureus aerobic physiology was reported. Specifically, aerobic S. aureus nos mutant cultures presented with elevated endogenous reactive oxygen species (ROS) and superoxide levels, as well as increased membrane potential, increased respiratory dehydrogenase activity and slightly elevated oxygen consumption. Elevated ROS levels in the nos mutant likely resulted from altered respiratory function, as inhibition of NADH dehydrogenase brought ROS levels back to wild-type levels. These results indicate that, in addition to its recently reported role in regulating the switch to nitrate-based respiration during low-oxygen growth, saNOS also plays a modulatory role during aerobic respiration. Multiple transcriptional changes were also observed in the nos mutant, including elevated expression of genes associated with oxidative/nitrosative stress, anaerobic respiration and lactate metabolism. Targeted metabolomics revealed decreased cellular lactate levels, and altered levels of TCA cycle intermediates, the latter of which may be related to decreased aconitase activity. Collectively, these findings demonstrate a key contribution of saNOS to S. aureus aerobic respiratory metabolism.
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Affiliation(s)
- Austin B. Mogen
- Department of Microbiology and Cell Science, IFAS, University of Florida, Gainesville, FL, 32611-0700
| | - Ronan K. Carroll
- Department of Biological Sciences, Ohio University, Athens, Ohio, 45701
| | - Kimberly L. James
- Department of Microbiology and Cell Science, IFAS, University of Florida, Gainesville, FL, 32611-0700
| | - Genevy Lima
- Department of Microbiology and Cell Science, IFAS, University of Florida, Gainesville, FL, 32611-0700
| | - Dona Silva
- Department of Microbiology and Cell Science, IFAS, University of Florida, Gainesville, FL, 32611-0700
| | - Jeffrey A. Culver
- Metabolomics Core, Sanford Burnham Prebys Medical Discovery Institute, Orlando, FL, 32827
- Southeast Center for Integrated Metabolomics, University of Florida, Gainesville, FL, 32611
| | - Christopher Petucci
- Metabolomics Core, Sanford Burnham Prebys Medical Discovery Institute, Orlando, FL, 32827
- Southeast Center for Integrated Metabolomics, University of Florida, Gainesville, FL, 32611
| | - Lindsey N. Shaw
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, FL, 33620-5150
| | - Kelly C. Rice
- Department of Microbiology and Cell Science, IFAS, University of Florida, Gainesville, FL, 32611-0700
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16
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Verderosa AD, de la Fuente-Núñez C, Mansour SC, Cao J, Lu TK, Hancock REW, Fairfull-Smith KE. Ciprofloxacin-nitroxide hybrids with potential for biofilm control. Eur J Med Chem 2017; 138:590-601. [PMID: 28709125 DOI: 10.1016/j.ejmech.2017.06.058] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Revised: 06/26/2017] [Accepted: 06/27/2017] [Indexed: 01/15/2023]
Abstract
As bacterial biofilms display extreme tolerance to conventional antibiotic treatments, it has become imperative to develop new antibacterial strategies with alternative mechanisms of action. Herein, we report the synthesis of a series of ciprofloxacin-nitroxide conjugates and their corresponding methoxyamine derivatives in high yield. This was achieved by linking various nitroxides or methoxyamines to the secondary amine of the piperazine ring of ciprofloxacin using amide bond coupling. Biological evaluation of the prepared compounds on preformed P. aeruginosa biofilms in flow cells revealed substantial dispersal with ciprofloxacin-nitroxide hybrid 25, and virtually complete killing and removal (94%) of established biofilms in the presence of ciprofloxacin-nitroxide hybrid 27. Compounds 25-28 were shown to be non-toxic in both human embryonic kidney 293 (HEK 293) cells and human muscle rhabdomyosarcoma (RD) cells at concentrations up to 40 μM. Significantly, these hybrids demonstrate the potential of antimicrobial-nitroxide agents to overcome the resistance of biofilms to antimicrobials via stimulation of biofilm dispersal or through direct cell killing.
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Affiliation(s)
- Anthony D Verderosa
- ARC Centre of Excellence for Free Radical Chemistry and Biotechnology, Faculty of Science and Engineering, Queensland University of Technology, Queensland 4001, Australia
| | - César de la Fuente-Núñez
- Synthetic Biology Group, MIT Synthetic Biology Center, Massachusetts Institute of Technology, Cambridge, MA, United States; Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, United States; Department of Biological Engineering, Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, United States; Broad Institute of MIT and Harvard, Cambridge, MA, United States; Harvard Biophysics Program, Harvard University, Boston, MA, United States; The Center for Microbiome Informatics and Therapeutics, Cambridge, MA, United States
| | - Sarah C Mansour
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Jicong Cao
- Synthetic Biology Group, MIT Synthetic Biology Center, Massachusetts Institute of Technology, Cambridge, MA, United States; Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, United States; Department of Biological Engineering, Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, United States; Broad Institute of MIT and Harvard, Cambridge, MA, United States; Harvard Biophysics Program, Harvard University, Boston, MA, United States; The Center for Microbiome Informatics and Therapeutics, Cambridge, MA, United States
| | - Timothy K Lu
- Synthetic Biology Group, MIT Synthetic Biology Center, Massachusetts Institute of Technology, Cambridge, MA, United States; Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, United States; Department of Biological Engineering, Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, United States; Broad Institute of MIT and Harvard, Cambridge, MA, United States; Harvard Biophysics Program, Harvard University, Boston, MA, United States; The Center for Microbiome Informatics and Therapeutics, Cambridge, MA, United States
| | - Robert E W Hancock
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Kathryn E Fairfull-Smith
- ARC Centre of Excellence for Free Radical Chemistry and Biotechnology, Faculty of Science and Engineering, Queensland University of Technology, Queensland 4001, Australia.
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17
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Prescott C, Bottle SE. Biological Relevance of Free Radicals and Nitroxides. Cell Biochem Biophys 2017; 75:227-240. [PMID: 27709467 DOI: 10.1007/s12013-016-0759-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 08/18/2016] [Indexed: 12/31/2022]
Abstract
Nitroxides are stable, kinetically-persistent free radicals which have been successfully used in the study and intervention of oxidative stress, a critical issue pertaining to cellular health which results from an imbalance in the levels of damaging free radicals and redox-active species in the cellular environment. This review gives an overview of some of the biological processes that produce radicals and other reactive oxygen species with relevance to oxidative stress, and then discusses interactions of nitroxides with these species in terms of the use of nitroxides as redox-sensitive probes and redox-active therapeutic agents.
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18
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Fancy NN, Bahlmann AK, Loake GJ. Nitric oxide function in plant abiotic stress. PLANT, CELL & ENVIRONMENT 2017; 40:462-472. [PMID: 26754426 DOI: 10.1111/pce.12707] [Citation(s) in RCA: 209] [Impact Index Per Article: 29.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Revised: 12/09/2015] [Accepted: 12/26/2015] [Indexed: 05/17/2023]
Abstract
Abiotic stress is one of the main threats affecting crop growth and production. An understanding of the molecular mechanisms that underpin plant responses against environmental insults will be crucial to help guide the rational design of crop plants to counter these challenges. A key feature during abiotic stress is the production of nitric oxide (NO), an important concentration dependent, redox-related signalling molecule. NO can directly or indirectly interact with a wide range of targets leading to the modulation of protein function and the reprogramming of gene expression. The transfer of NO bioactivity can occur through a variety of potential mechanisms but chief among these is S-nitrosylation, a prototypic, redox-based, post-translational modification. However, little is known about this pivotal molecular amendment in the regulation of abiotic stress signalling. Here, we describe the emerging knowledge concerning the function of NO and S-nitrosylation during plant responses to abiotic stress.
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Affiliation(s)
- Nurun Nahar Fancy
- Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, The King's Buildings, Edinburgh, UK, EH9 3BF
| | - Ann-Kathrin Bahlmann
- Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, The King's Buildings, Edinburgh, UK, EH9 3BF
- Technische Universität Braunschweig, Braunschweig, D-38106, Germany
| | - Gary J Loake
- Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, The King's Buildings, Edinburgh, UK, EH9 3BF
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19
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Javadov S, Jang S, Rodriguez-Reyes N, Rodriguez-Zayas AE, Soto Hernandez J, Krainz T, Wipf P, Frontera W. Mitochondria-targeted antioxidant preserves contractile properties and mitochondrial function of skeletal muscle in aged rats. Oncotarget 2016; 6:39469-81. [PMID: 26415224 PMCID: PMC4741839 DOI: 10.18632/oncotarget.5783] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Accepted: 08/31/2015] [Indexed: 12/27/2022] Open
Abstract
Mitochondrial dysfunction plays a central role in the pathogenesis of sarcopenia associated with a loss of mass and activity of skeletal muscle. In addition to energy deprivation, increased mitochondrial ROS damage proteins and lipids in aged skeletal muscle. Therefore, prevention of mitochondrial ROS is important for potential therapeutic strategies to delay sarcopenia. This study elucidates the pharmacological efficiency of the new developed mitochondria-targeted ROS and electron scavenger, XJB-5-131 (XJB) to restore muscle contractility and mitochondrial function in aged skeletal muscle. Male adult (5-month old) and aged (29-month old) Fischer Brown Norway (F344/BN) rats were treated with XJB for four weeks and contractile properties of single skeletal muscle fibres and activity of mitochondrial ETC complexes were determined at the end of the treatment period. XJB-treated old rats showed higher muscle contractility associated with prevention of protein oxidation in both muscle homogenate and mitochondria compared with untreated counterparts. XJB-treated animals demonstrated a high activity of the respiratory complexes I, III, and IV with no changes in citrate synthase activity. These data demonstrate that mitochondrial ROS play a causal role in muscle weakness, and that a ROS scavenger specifically targeted to mitochondria can reverse age-related alterations of mitochondrial function and improve contractile properties in skeletal muscle.
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Affiliation(s)
- Sabzali Javadov
- Department of Physiology, School of Medicine, University of Puerto Rico, San Juan, PR, USA
| | - Sehwan Jang
- Department of Physiology, School of Medicine, University of Puerto Rico, San Juan, PR, USA
| | | | - Ana E Rodriguez-Zayas
- Department of Physiology, School of Medicine, University of Puerto Rico, San Juan, PR, USA
| | - Jessica Soto Hernandez
- Department of Physiology, School of Medicine, University of Puerto Rico, San Juan, PR, USA
| | - Tanja Krainz
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, USA
| | - Peter Wipf
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, USA
| | - Walter Frontera
- Department of Physiology, School of Medicine, University of Puerto Rico, San Juan, PR, USA.,Department of Physical Medicine and Rehabilitation, Vanderbilt University School of Medicine, Nashville, TN, USA
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20
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Synthesis and Evaluation of Ciprofloxacin-Nitroxide Conjugates as Anti-Biofilm Agents. Molecules 2016; 21:molecules21070841. [PMID: 27355936 PMCID: PMC6273952 DOI: 10.3390/molecules21070841] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Revised: 06/17/2016] [Accepted: 06/21/2016] [Indexed: 12/14/2022] Open
Abstract
As bacterial biofilms are often refractory to conventional antimicrobials, the need for alternative and/or novel strategies for the treatment of biofilm related infections has become of paramount importance. Herein, we report the synthesis of novel hybrid molecules comprised of two different hindered nitroxides linked to the piperazinyl secondary amine of ciprofloxacin via a tertiary amine linker achieved utilising reductive amination. The corresponding methoxyamine derivatives were prepared alongside their radical-containing counterparts as controls. Subsequent biological evaluation of the hybrid compounds on preformed P. aeruginosa flow cell biofilms divulged significant dispersal and eradication abilities for ciprofloxacin-nitroxide hybrid compound 10 (up to 95% eradication of mature biofilms at 40 μM). Importantly, these hybrids represent the first dual-action antimicrobial-nitroxide agents, which harness the dispersal properties of the nitroxide moiety to circumvent the well-known resistance of biofilms to treatment with antimicrobial agents.
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21
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Fan PC, Ma HP, Jiang W, Li L, Ren J, Jing LL, Jia ZP. Anti-hypoxia Activity of the Novel NO Donor Acetyl Ferulic Isosorbide Mononitrate in Acute High-Altitude Hypoxia Mice. Biol Pharm Bull 2016; 38:1280-9. [PMID: 26328483 DOI: 10.1248/bpb.b15-00131] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Nitric oxide (NO) may act as either a pro-oxidant or an antioxidant in biological systems. Previous work has found inhalation of NO improved survival in a high altitude rat model. NO donor isosorbide mononitrate derivants might have a protective effect against hypoxia. We synthesized a series of isosorbide mononitrate derivant compounds to test their anti-hypoxia activities. Normobaric hypoxia and hypobaric hypoxia models were used to study the protective role of NO donor in mice. The results showed isosorbide mononitrate derivants had protective effects in hypoxia mice. Among those compounds, acetyl ferulic isosorbide mononitrate (AFIM) was the most effective. It prolonged the survival time during the normobaric hypoxia test. It decreased malondialdehyde (MDA) and H2O2 in hypobaric hypoxia mice. The antioxidase activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) remained in normal ranges in the AFIM group. As a sign of mitochondrial dysfunction, the activities of ATPase were down regulated in mice under hypobaric hypoxia conditions. AFIM also protected ATPase activities. The protective effects of AFIM might come from a sustained NO supply and the release of acetyl ferulic acid with anti-oxidant activity.
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Affiliation(s)
- Peng-Cheng Fan
- Department of Pharmacy, General Hospital of Lanzhou Command of PLA
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22
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Real-time quantification of oxidative stress and the protective effect of nitroxide antioxidants. Neurochem Int 2016; 92:1-12. [DOI: 10.1016/j.neuint.2015.11.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Revised: 10/28/2015] [Accepted: 11/10/2015] [Indexed: 11/18/2022]
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23
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Chatgilialoglu C, Ferreri C, Matyjaszewski K. Radicals and Dormant Species in Biology and Polymer Chemistry. Chempluschem 2015; 81:11-29. [DOI: 10.1002/cplu.201500271] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Indexed: 12/20/2022]
Affiliation(s)
| | - Carla Ferreri
- I.S.O.F.-BioFreeRadicals; Consiglio Nazionale delle Ricerche; Via P. Gobetti 101 Bologna 40129 Italy
| | - Krzysztof Matyjaszewski
- Department of Chemistry; Carnegie Mellon University; 4400 Fifth Avenue Pittsburgh PA 15213 USA
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24
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van Lith R, Yang J, Ameer GA. Diazeniumdiolation of protamine sulfate reverses mitogenic effects on smooth muscle cells and fibroblasts. Free Radic Biol Med 2015; 82:13-21. [PMID: 25656996 DOI: 10.1016/j.freeradbiomed.2015.01.022] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Revised: 01/16/2015] [Accepted: 01/26/2015] [Indexed: 12/16/2022]
Abstract
After vascular interventions, endothelial cells are typically injured or lacking, resulting in decreased NO synthesis to maintain vascular health. Moreover, inflammation as a result of the tissue injury and/or the presence of an implanted foreign polymer such as a vascular graft causes excessive generation of reactive oxygen species (ROS) (e.g., superoxide), which can react with NO. The combination of the above creates a general decline in NO bioavailability, as well as oxidative stress due to less available NO to scavenge ROS. Localized NO delivery is an attractive solution to alleviate these issues; however, NO donors typically exhibit unpredictable NO payload release when using nitrosothiols or the risk of nitrosamine formation for synthetic diazeniumdiolates. The objective of this study was therefore to synthesize an NO donor from a biological peptide that could revert to its native form upon NO release. To this effect, protamine sulfate (PS), an FDA-approved peptide with reported vasodilator and anticoagulant properties, was diazeniumdiolated to form PS/NO. PS/NO showed diazeniumdiolate-characteristic UV peaks and NO release in physiological solutions and was capable of scavenging radicals to decrease oxidative stress. Furthermore, PS/NO selectively inhibits the proliferation of smooth muscle cells and adventitial fibroblasts, thereby reversing reported mitogenic properties of PS. Endothelial cell growth, on the other hand, was promoted by PS/NO. Finally, PS retained its anticoagulant properties upon diazeniumdiolation at clinically relevant concentrations. In conclusion, we have synthesized an NO prodrug from a biological peptide, PS/NO, that selectively inhibits proliferation of smooth muscle cells and fibroblasts, retains anticoagulant properties, and reverts back to its native PS form upon NO payload release.
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Affiliation(s)
- Robert van Lith
- Biomedical Engineering Department, Northwestern University, Evanston, IL 60208, USA
| | - Jian Yang
- Biomedical Engineering Department, Northwestern University, Evanston, IL 60208, USA
| | - Guillermo A Ameer
- Biomedical Engineering Department, Northwestern University, Evanston, IL 60208, USA; Department of Surgery, Feinberg School of Medicine, Chicago, IL 60611, USA; Chemistry of Life Processes Institute, Northwestern University, Evanston, IL 60208, USA; Simpson Querrey Institute, Northwestern University, Evanston, IL 60208, USA.
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25
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Kim CHJ, Mitchell JB, Bursill CA, Sowers AL, Thetford A, Cook JA, van Reyk DM, Davies MJ. The nitroxide radical TEMPOL prevents obesity, hyperlipidaemia, elevation of inflammatory cytokines, and modulates atherosclerotic plaque composition in apoE-/- mice. Atherosclerosis 2015; 240:234-41. [PMID: 25818249 DOI: 10.1016/j.atherosclerosis.2015.03.012] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Revised: 01/21/2015] [Accepted: 03/08/2015] [Indexed: 01/17/2023]
Abstract
OBJECTIVE The nitroxide compound TEMPOL (4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl radical) has been shown to prevent obesity-induced changes in adipokines in cell and animal systems. In this study we investigated whether supplementation with TEMPOL inhibits inflammation and atherosclerosis in apoE-/- mice fed a high fat diet (HFD). METHODS ApoE-/- mice were fed for 12 weeks on standard chow diet or a high-fat diet. Half the mice were supplemented with 10 mg/g TEMPOL in their food. Plasma samples were analysed for triglycerides, cholesterol, low- and high-density lipoprotein cholesterol, inflammatory cytokines and markers (interleukin-6, IL-6; monocyte-chemotactic protein, MCP-1; myeloperoxidase, MPO; serum amyloid A, SAA; adiponectin; leptin). Plaques in the aortic sinus were analysed for area, and content of collagen, lipid, macrophages and smooth muscle cells. RESULTS High fat feeding resulted in marked increases in body mass and plasma lipid levels. Dietary TEMPOL decreased both parameters. In the high-fat-fed mice significant elevations in plasma lipid levels and the inflammatory markers IL-6, MCP-1, MPO, SAA were detected, along with an increase in leptin and a decrease in adiponectin. TEMPOL supplementation reversed these effects. When compared to HFD-fed mice, TEMPOL supplementation increased plaque collagen content, decreased lipid content and increased macrophage numbers. CONCLUSIONS These data indicate that in a well-established model of obesity-associated hyperlipidaemia and atherosclerosis, TEMPOL had a significant impact on body mass, atherosclerosis, hyperlipidaemia and inflammation. TEMPOL may therefore be of value in suppressing obesity, metabolic disorders and increasing atherosclerotic plaque stability.
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Affiliation(s)
- Christine H J Kim
- Free Radical Group, Heart Research Institute, 7 Eliza Street, Newtown, NSW 2042, Australia; Faculty of Medicine, University of Sydney, NSW 2006, Australia.
| | - James B Mitchell
- National Cancer Institute, Radiation Biology Branch, Center for Cancer Research, Building 10, Room B3-B69, Bethesda, MD 20892, USA.
| | - Christina A Bursill
- Faculty of Medicine, University of Sydney, NSW 2006, Australia; Immunobiology Group, Heart Research Institute, 7 Eliza Street, Newtown, NSW 2042, Australia.
| | - Anastasia L Sowers
- National Cancer Institute, Radiation Biology Branch, Center for Cancer Research, Building 10, Room B3-B69, Bethesda, MD 20892, USA.
| | - Angela Thetford
- National Cancer Institute, Radiation Biology Branch, Center for Cancer Research, Building 10, Room B3-B69, Bethesda, MD 20892, USA.
| | - John A Cook
- National Cancer Institute, Radiation Biology Branch, Center for Cancer Research, Building 10, Room B3-B69, Bethesda, MD 20892, USA.
| | - David M van Reyk
- Faculty of Science, University of Technology Sydney, PO Box 123, Broadway, NSW 2007, Australia.
| | - Michael J Davies
- Free Radical Group, Heart Research Institute, 7 Eliza Street, Newtown, NSW 2042, Australia; Faculty of Medicine, University of Sydney, NSW 2006, Australia; Department of Biomedical Sciences, Building 4.5, Panum Institute, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark.
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26
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Reffuveille F, Fuente-Núñez CDL, Fairfull-Smith KE, Hancock REW. Potentiation of ciprofloxacin action against Gram-negative bacterial biofilms by a nitroxide. Pathog Dis 2015; 73:ftv016. [DOI: 10.1093/femspd/ftv016] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/21/2015] [Indexed: 11/15/2022] Open
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27
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Yu H, Cao L, Li F, Wu Q, Li Q, Wang S, Guo Y. The antioxidant mechanism of nitroxide TEMPO: scavenging with glutathionyl radicals. RSC Adv 2015. [DOI: 10.1039/c5ra06129f] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A rhodamine-nitroxide probe (R-NO˙) was introduced to probe glutathionyl radicals (GS˙) with high sensitivity and selectivity.
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Affiliation(s)
- Hui Yu
- Key Laboratory of Chemistry of Northwestern Plant Resources
- CAS and Key Laboratory for Natural Medicine of Gansu Province
- Lanzhou Institute of Chemical Physics
- Chinese Academy of Sciences
- Lanzhou 730000
| | - Linying Cao
- Key Laboratory of Chemistry of Northwestern Plant Resources
- CAS and Key Laboratory for Natural Medicine of Gansu Province
- Lanzhou Institute of Chemical Physics
- Chinese Academy of Sciences
- Lanzhou 730000
| | - Feifei Li
- Institute of Modern Physics
- Chinese Academy of Sciences
- Lanzhou 730000
- P. R. China
- University of Chinese Academy of Sciences
| | - Qingfeng Wu
- Institute of Modern Physics
- Chinese Academy of Sciences
- Lanzhou 730000
- P. R. China
| | - Qiang Li
- Institute of Modern Physics
- Chinese Academy of Sciences
- Lanzhou 730000
- P. R. China
| | - Shuai Wang
- Key Laboratory of Chemistry of Northwestern Plant Resources
- CAS and Key Laboratory for Natural Medicine of Gansu Province
- Lanzhou Institute of Chemical Physics
- Chinese Academy of Sciences
- Lanzhou 730000
| | - Yong Guo
- Key Laboratory of Chemistry of Northwestern Plant Resources
- CAS and Key Laboratory for Natural Medicine of Gansu Province
- Lanzhou Institute of Chemical Physics
- Chinese Academy of Sciences
- Lanzhou 730000
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28
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Escobales N, Nuñez RE, Jang S, Parodi-Rullan R, Ayala-Peña S, Sacher JR, Skoda EM, Wipf P, Frontera W, Javadov S. Mitochondria-targeted ROS scavenger improves post-ischemic recovery of cardiac function and attenuates mitochondrial abnormalities in aged rats. J Mol Cell Cardiol 2014; 77:136-46. [PMID: 25451170 PMCID: PMC4312194 DOI: 10.1016/j.yjmcc.2014.10.009] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Revised: 10/14/2014] [Accepted: 10/17/2014] [Indexed: 01/21/2023]
Abstract
Mitochondria-generated reactive oxygen species (ROS) play a crucial role in the pathogenesis of aging and age-associated diseases. In this study, we evaluated the effects of XJB-5-131 (XJB), a mitochondria-targeted ROS and electron scavenger, on cardiac resistance to ischemia-reperfusion (IR)-induced oxidative stress in aged rats. Male adult (5-month old, n=17) and aged (29-month old, n=19) Fischer Brown Norway (F344/BN) rats were randomly assigned to the following groups: adult (A), adult+XJB (AX), aged (O), and aged+XJB (OX). XJB was administered 3 times per week (3mg/kg body weight, IP) for four weeks. At the end of the treatment period, cardiac function was continuously monitored in excised hearts using the Langendorff technique for 30 min, followed by 20 min of global ischemia, and 60-min reperfusion. XJB improved post-ischemic recovery of aged hearts, as evidenced by greater left ventricular developed-pressures and rate-pressure products than the untreated, aged-matched group. The state 3 respiration rates at complexes I, II and IV of mitochondria isolated from XJB-treated aged hearts were 57% (P<0.05), 25% (P<0.05) and 28% (P<0.05), respectively, higher than controls. Ca(2+)-induced swelling, an indicator of permeability transition pore opening, was reduced in the mitochondria of XJB-treated aged rats. In addition, XJB significantly attenuated the H2O2-induced depolarization of the mitochondrial inner membrane as well as the total and mitochondrial ROS levels in cultured cardiomyocytes. This study underlines the importance of mitochondrial ROS in aging-induced cardiac dysfunction and suggests that targeting mitochondrial ROS may be an effective therapeutic approach to protect the aged heart against IR injury.
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Affiliation(s)
- Nelson Escobales
- Department of Physiology, School of Medicine, University of Puerto Rico, San Juan, Puerto Rico
| | - Rebeca E Nuñez
- Department of Physiology, School of Medicine, University of Puerto Rico, San Juan, Puerto Rico
| | - Sehwan Jang
- Department of Physiology, School of Medicine, University of Puerto Rico, San Juan, Puerto Rico
| | - Rebecca Parodi-Rullan
- Department of Physiology, School of Medicine, University of Puerto Rico, San Juan, Puerto Rico
| | - Sylvette Ayala-Peña
- Department of Pharmacology and Toxicology, School of Medicine, University of Puerto Rico, San Juan, Puerto Rico
| | - Joshua R Sacher
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, USA
| | - Erin M Skoda
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, USA
| | - Peter Wipf
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, USA
| | - Walter Frontera
- Department of Physiology, School of Medicine, University of Puerto Rico, San Juan, Puerto Rico; Department of Physical Medicine and Rehabilitation, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Sabzali Javadov
- Department of Physiology, School of Medicine, University of Puerto Rico, San Juan, Puerto Rico.
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Sadowska-Bartosz I, Galiniak S, Skolimowski J, Stefaniuk I, Bartosz G. Nitroxides prevent protein glycoxidationin vitro. Free Radic Res 2014; 49:113-21. [DOI: 10.3109/10715762.2014.982113] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Kajer TB, Fairfull-Smith KE, Yamasaki T, Yamada KI, Fu S, Bottle SE, Hawkins CL, Davies MJ. Inhibition of myeloperoxidase- and neutrophil-mediated oxidant production by tetraethyl and tetramethyl nitroxides. Free Radic Biol Med 2014; 70:96-105. [PMID: 24566469 DOI: 10.1016/j.freeradbiomed.2014.02.011] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Revised: 01/23/2014] [Accepted: 02/12/2014] [Indexed: 12/17/2022]
Abstract
The powerful oxidant HOCl (hypochlorous acid and its corresponding anion, (-)OCl) generated by the myeloperoxidase (MPO)-H2O2-Cl(-) system of activated leukocytes is strongly associated with multiple human inflammatory diseases; consequently there is considerable interest in inhibition of this enzyme. Nitroxides are established antioxidants of low toxicity that can attenuate oxidation in animal models, with this ascribed to superoxide dismutase or radical-scavenging activities. We have shown (M.D. Rees et al., Biochem. J. 421, 79-86, 2009) that nitroxides, including 4-amino-TEMPO (4-amino-2,2,6,6-tetramethylpiperidin-1-yloxyl radical), are potent inhibitors of HOCl formation by isolated MPO and activated neutrophils, with IC50 values of ~1 and ~6 µM respectively. The utility of tetramethyl-substituted nitroxides is, however, limited by their rapid reduction by biological reductants. The corresponding tetraethyl-substituted nitroxides have, however, been reported to be less susceptible to reduction. In this study we show that the tetraethyl species were reduced less rapidly than the tetramethyl species by both human plasma (89-99% decreased rate of reduction) and activated human neutrophils (62-75% decreased rate). The tetraethyl-substituted nitroxides retained their ability to inhibit HOCl production by MPO and activated neutrophils with IC50 values in the low-micromolar range; in some cases inhibition was enhanced compared to tetramethyl substitution. Nitroxides with rigid structures (fused oxaspiro rings) were, however, inactive. Overall, these data indicate that tetraethyl-substituted nitroxides are potent inhibitors of oxidant formation by MPO, with longer plasma and cellular half-lives compared to the tetramethyl species, potentially allowing lower doses to be employed.
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Affiliation(s)
- Tracey B Kajer
- Heart Research Institute, Newtown, Sydney, NSW 2042, Australia; Faculty of Medicine, University of Sydney, Sydney, NSW, Australia
| | - Kathryn E Fairfull-Smith
- School of Physical and Chemical Sciences, Queensland University of Technology, Brisbane, QLD, Australia
| | - Toshihide Yamasaki
- Faculty of Pharmaceutical Sciences, Kyushu University, Fukuoka, Kyushu, Japan
| | - Ken-ichi Yamada
- Faculty of Pharmaceutical Sciences, Kyushu University, Fukuoka, Kyushu, Japan
| | - Shanlin Fu
- Centre for Forensic Science, University of Technology, Sydney, NSW, Australia
| | - Steven E Bottle
- School of Physical and Chemical Sciences, Queensland University of Technology, Brisbane, QLD, Australia
| | - Clare L Hawkins
- Heart Research Institute, Newtown, Sydney, NSW 2042, Australia; Faculty of Medicine, University of Sydney, Sydney, NSW, Australia
| | - Michael J Davies
- Heart Research Institute, Newtown, Sydney, NSW 2042, Australia; Faculty of Medicine, University of Sydney, Sydney, NSW, Australia.
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The carbonylation and covalent dimerization of human superoxide dismutase 1 caused by its bicarbonate-dependent peroxidase activity is inhibited by the radical scavenger tempol. Biochem J 2013; 455:37-46. [DOI: 10.1042/bj20130180] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The nitroxide tempol inhibited the carbonylation and covalent dimerization of human superoxide dismutase 1 caused by its bicarbonate-dependent peroxidase activity. Tempol acted by scavenging the produced carbonate radical and by recombining with hSOD1-Trp32• radicals as indicated by MS/MS evidence.
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32
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Effect of nitroxides on swarming motility and biofilm formation, multicellular behaviors in Pseudomonas aeruginosa. Antimicrob Agents Chemother 2013; 57:4877-81. [PMID: 23877682 DOI: 10.1128/aac.01381-13] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The ability of nitric oxide (NO) to induce biofilm dispersion has been well established. Here, we investigated the effect of nitroxides (sterically hindered nitric oxide analogues) on biofilm formation and swarming motility in Pseudomonas aeruginosa. A transposon mutant unable to produce nitric oxide endogenously (nirS) was deficient in swarming motility relative to the wild type and the complemented strain. Moreover, expression of the nirS gene was upregulated by 9.65-fold in wild-type swarming cells compared to planktonic cells. Wild-type swarming levels were substantially restored upon the exogenous addition of nitroxide containing compounds, a finding consistent with the hypothesis that NO is necessary for swarming motility. Here, we showed that nitroxides not only mimicked the dispersal activity of NO but also prevented biofilms from forming in flow cell chambers. In addition, a nirS transposon mutant was deficient in biofilm formation relative to the wild type and the complemented strain, thus implicating NO in the formation of biofilms. Intriguingly, despite its stand-alone action in inhibiting biofilm formation and promoting dispersal, a nitroxide partially restored the ability of a nirS mutant to form biofilms.
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Kirk BB, Trevitt AJ, Blanksby SJ. Does addition of NO2 to carbon-centered radicals yield RONO or RNO2? An investigation using distonic radical ions. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2013; 24:481-492. [PMID: 23436231 DOI: 10.1007/s13361-012-0549-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Revised: 11/25/2012] [Accepted: 11/26/2012] [Indexed: 06/01/2023]
Abstract
Nitrogen dioxide is used as a "radical scavenger" to probe the position of carbon-centered radicals within complex radical ions in the gas phase. As with analogous neutral radical reactions, this addition results in formation of an [M + NO2](+) adduct, but the structural identity of this species remains ambiguous. Specifically, the question remains: do such adducts have a nitro- (RNO2) or nitrosoxy- (RONO) moiety, or are both isomers present in the adduct population? In order to elucidate the products of such reactions, we have prepared and isolated three distonic phenyl radical cations and observed their reactions with nitrogen dioxide in the gas phase by ion-trap mass spectrometry. In each case, stabilized [M + NO2](+) adduct ions are observed and isolated. The structure of these adducts is probed by collision-induced dissociation and ultraviolet photodissociation action spectroscopy and a comparison made to the analogous spectra of authentic nitro- and nitrosoxy-benzenes. We demonstrate unequivocally that for the phenyl radical cations studied here, all stabilized [M + NO2](+) adducts are exclusively nitrobenzenes. Electronic structure calculations support these mass spectrometric observations and suggest that, under low-pressure conditions, the nitrosoxy-isomer is unlikely to be isolated from the reaction of an alkyl or aryl radical with NO2. The combined experimental and theoretical results lead to the prediction that stabilization of the nitrosoxy-isomer will only be possible for systems wherein the energy required for dissociation of the RO-NO bond (or other low energy fragmentation channels) rises close to, or above, the energy of the separated reactants.
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Affiliation(s)
- Benjamin B Kirk
- ARC Centre of Excellence for Free Radical Chemistry and Biotechnology, School of Chemistry, University of Wollongong, Wollongong, NSW, Australia
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Thomas K, Chalmers BA, Fairfull-Smith KE, Bottle SE. Approaches to the Synthesis of a Water-Soluble Carboxy Nitroxide. European J Org Chem 2013. [DOI: 10.1002/ejoc.201201551] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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36
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Queiroz RF, Jordão AK, Cunha AC, Ferreira VF, Brigagão MRPL, Malvezzi A, Amaral ATD, Augusto O. Nitroxides attenuate carrageenan-induced inflammation in rat paws by reducing neutrophil infiltration and the resulting myeloperoxidase-mediated damage. Free Radic Biol Med 2012; 53:1942-53. [PMID: 22982597 DOI: 10.1016/j.freeradbiomed.2012.09.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2012] [Revised: 08/14/2012] [Accepted: 09/06/2012] [Indexed: 01/30/2023]
Abstract
Tempol (4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl) and other cyclic nitroxides have been shown to inhibit the chlorinating activity of myeloperoxidase (MPO) in vitro and in cells. To examine whether nitroxides inhibit MPO activity in vivo we selected acute carrageenan-induced inflammation on the rat paw as a model. Tempol and three more hydrophobic 4-substituted derivatives (4-azido, 4-benzenesulfonyl, and 4-(4-phenyl-1H-1,2,3-triazol-1-yl)) were synthesized, and their ability to inhibit the in vitro chlorinating activity of MPO and carrageenan-induced inflammation in rat paws was evaluated. All of the tested nitroxides inhibited the chlorinating activity of MPO in vitro with similar IC(50) values (between 1.5 and 1.8 μM). In vivo, the attenuation of carrageenan-induced inflammation showed some correlation with the lipophilicity of the nitroxide at early time points but the differences in the effects were small (<2-fold) compared with the differences in lipophilicity (>200-fold). No inhibition of MPO activity in vivo was evident because the levels of MPO activity in rat paws correlated with the levels of MPO protein. Likewise, paw edema, levels of nitrated and oxidized proteins, and levels of plasma exudation correlated with the levels of MPO protein in the paws of the animals that were untreated or treated with the nitroxides. The effects of the nitroxides in vivo were compared with those of 4-aminobenzoic hydrazide and of colchicine. Taken together, the results indicate that nitroxides attenuate carrageenan-induced inflammation mainly by reducing neutrophil migration and the resulting MPO-mediated damage. Accordingly, tempol was shown to inhibit rat neutrophil migration in vitro.
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Affiliation(s)
- Raphael F Queiroz
- Departamento de Bioquímica and Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
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Pattison DI, Lam M, Shinde SS, Anderson RF, Davies MJ. The nitroxide TEMPO is an efficient scavenger of protein radicals: cellular and kinetic studies. Free Radic Biol Med 2012; 53:1664-74. [PMID: 22974763 DOI: 10.1016/j.freeradbiomed.2012.08.578] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2012] [Revised: 08/10/2012] [Accepted: 08/20/2012] [Indexed: 11/18/2022]
Abstract
Protein oxidation occurs during multiple human pathologies, and protein radicals are known to induce damage to other cell components. Such damage may be modulated by agents that scavenge protein radicals. In this study, the potential protective reactions of the nitroxide TEMPO (2,2,6,6-tetramethyl-1-piperidinyloxyl radical) against Tyr- and Trp-derived radicals (TyrO./TrpN.) have been investigated. Pretreatment of macrophage cells with TEMPO provided protection against photo-oxidation-induced loss of cell viability and Tyr oxidation, with the nitroxide more effective than the hydroxylamine or parent amine. Pulse radiolysis was employed to determine rate constants, k, for the reaction of TEMPO with TyrO. and TrpN. generated on N-Ac-Tyr-amide and N-Ac-Trp-amide, with values of k~10(8) and 7×10(6)M(-1)s(-1), respectively, determined. Analogous studies with lysozyme, chymotrypsin, and pepsin yielded k for TEMPO reacting with TrpN. ranging from 1.5×10(7) (lysozyme) to 1.1×10(8) (pepsin)M(-1)s(-1). Pepsin-derived TyrO. reacted with TEMPO with k~4×10(7)M(-1)s(-1); analogous reactions for lysozyme and chymotrypsin TyrO. were much slower. These data indicate that TEMPO can inhibit secondary reactions of both TyrO. and TrpN., though this is protein dependent. Such protein radical scavenging may contribute to the positive biological effects of nitroxides.
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38
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Samuni Y, Samuni U, Goldstein S. The use of cyclic nitroxide radicals as HNO scavengers. J Inorg Biochem 2012; 118:155-61. [PMID: 23122928 DOI: 10.1016/j.jinorgbio.2012.10.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Revised: 09/11/2012] [Accepted: 10/04/2012] [Indexed: 11/18/2022]
Abstract
Reduction of cyclic stable nitroxides (RNO) by HNO to the respective hydroxylamines (RNO-H) has been demonstrated using EPR spectrometry. HNO shows low reactivity toward piperidine, pyrrolidine and nitronyl nitroxides with rate constants below 1.4 × 10(5)M(-1)s(-1) at pH 7.0, despite the high driving force for these reactions. The rate constants can be predicted assuming that the reactions take place via a concerted proton-electron transfer pathway and significantly low self-exchange rate constants for HNO/NO and RNO-H/RNO. NO does not react with piperidine and pyrrolidine nitroxides, but does add to HNO forming the highly oxidizing and moderately reducing hyponitrite radicals. In this work, the radicals are produced by pulse radiolysis and the rate constants of their reactions with 2,2,6,6,-tetramethylpiperidine-1-oxyl (TEMPO), 4-hydroxy-2,2,6,6-tetramethyl piperidine-1-oxyl (TEMPOL) and 3-carbamoyl-PROXYL have been determined at pH 6.8 to be (2.4 ± 0.2)× 10(6), (9.8 ± 0.2)× 10(5), (5.9 ± 0.5)× 10(5)M(-1)s(-1), respectively. This low reactivity implies that NO competes efficiently with these nitroxides for the hyponitrite radical. The ability of TEMPOL and 2-(4-carboxyphenyl)-4,4,5,5,-tetramethyl-imidazoline-1-oxyl-3-oxide (C-PTIO) to oxidize HNO and their different reactivity toward NO are used to quantify HNO formed via acetohydroxamic acid oxidation. The extent of TEMPOL or C-PTIO reduction was similar to the yield of HNO formed upon oxidation by ()OH under anoxia, but not by the metmyoglobin and H(2)O(2) reaction system where both nitroxides catalytically facilitate H(2)O(2) depletion and nitrite accumulation. In this system the conversion of C-PTIO into 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl (C-PTI) is a minor reaction, which does not provide any mechanistic insight.
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Affiliation(s)
- Yuval Samuni
- Oral and Maxillofacial Surgery, The Barzilai Medical Center, Ashkelon, Israel
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Petrlova J, Kálai T, Maezawa I, Altman R, Harishchandra G, Hong HS, Bricarello DA, Parikh AN, Lorigan GA, Jin LW, Hideg K, Voss JC. The influence of spin-labeled fluorene compounds on the assembly and toxicity of the aβ peptide. PLoS One 2012; 7:e35443. [PMID: 22558151 PMCID: PMC3340382 DOI: 10.1371/journal.pone.0035443] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2011] [Accepted: 03/16/2012] [Indexed: 11/18/2022] Open
Abstract
Background The deposition and oligomerization of amyloid β (Aβ) peptide plays a key role in the pathogenesis of Alzheimer's disease (AD). Aβ peptide arises from cleavage of the membrane-associated domain of the amyloid precursor protein (APP) by β and γ secretases. Several lines of evidence point to the soluble Aβ oligomer (AβO) as the primary neurotoxic species in the etiology of AD. Recently, we have demonstrated that a class of fluorene molecules specifically disrupts the AβO species. Methodology/Principal Findings To achieve a better understanding of the mechanism of action of this disruptive ability, we extend the application of electron paramagnetic resonance (EPR) spectroscopy of site-directed spin labels in the Aβ peptide to investigate the binding and influence of fluorene compounds on AβO structure and dynamics. In addition, we have synthesized a spin-labeled fluorene (SLF) containing a pyrroline nitroxide group that provides both increased cell protection against AβO toxicity and a route to directly observe the binding of the fluorene to the AβO assembly. We also evaluate the ability of fluorenes to target multiple pathological processes involved in the neurodegenerative cascade, such as their ability to block AβO toxicity, scavenge free radicals and diminish the formation of intracellular AβO species. Conclusions Fluorene modified with pyrroline nitroxide may be especially useful in counteracting Aβ peptide toxicity, because they posses both antioxidant properties and the ability to disrupt AβO species.
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Affiliation(s)
- Jitka Petrlova
- Department of Biochemistry and Molecular Medicine, University of California Davis, Davis, California, United States of America
| | - Tamás Kálai
- Institute of Organic and Medicinal Chemistry, University of Pécs, Pécs, Hungary
| | - Izumi Maezawa
- Laboratory Medicine, Department of Pathology, M.I.N.D. Institute, Miami University, Oxford, Ohio, United States of America
| | - Robin Altman
- Department of Biochemistry and Molecular Medicine, University of California Davis, Davis, California, United States of America
| | - Ghimire Harishchandra
- Department of Chemistry and Biochemistry, Miami University, Oxford, Ohio, United States of America
| | - Hyun-Seok Hong
- Laboratory Medicine, Department of Pathology, M.I.N.D. Institute, Miami University, Oxford, Ohio, United States of America
| | - Daniel A. Bricarello
- Department of Applied Science, University of California Davis, Davis, California, United States of America
| | - Atul N. Parikh
- Department of Applied Science, University of California Davis, Davis, California, United States of America
| | - Gary A. Lorigan
- Department of Chemistry and Biochemistry, Miami University, Oxford, Ohio, United States of America
| | - Lee-Way Jin
- Laboratory Medicine, Department of Pathology, M.I.N.D. Institute, Miami University, Oxford, Ohio, United States of America
| | - Kálmán Hideg
- Institute of Organic and Medicinal Chemistry, University of Pécs, Pécs, Hungary
| | - John C. Voss
- Department of Biochemistry and Molecular Medicine, University of California Davis, Davis, California, United States of America
- * E-mail:
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Toledo JC, Augusto O. Connecting the Chemical and Biological Properties of Nitric Oxide. Chem Res Toxicol 2012; 25:975-89. [DOI: 10.1021/tx300042g] [Citation(s) in RCA: 196] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Jose Carlos Toledo
- Departamento de Química,
Faculdade de Filosofia, Ciências e Letras de Ribeirão
Preto, Universidade de São Paulo, CEP 14040-901, Ribeirão
Preto, SP, Brazil
| | - Ohara Augusto
- Departamento
de Bioquímica,
Instituto de Química, Universidade de São Paulo, Universidade
de São Paulo, Caixa Postal 26077, CEP 05513-970, São
Paulo, SP, Brazil
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41
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Inhibition of the chlorinating activity of myeloperoxidase by tempol: revisiting the kinetics and mechanisms. Biochem J 2011; 439:423-31. [DOI: 10.1042/bj20110555] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The nitroxide tempol (4-hydroxy-2,2,6,6-tetramethyl piperidine-1-oxyl) reduces tissue injury in animal models of inflammation by mechanisms that are not completely understood. MPO (myeloperoxidase), which plays a fundamental role in oxidant production by neutrophils, is an important target for anti-inflammatory action. By amplifying the oxidative potential of H2O2, MPO produces hypochlorous acid and radicals through the oxidizing intermediates MPO-I [MPO-porphyrin•+-Fe(IV)=O] and MPO-II [MPO-porphyrin-Fe(IV)=O]. Previously, we reported that tempol reacts with MPO-I and MPO-II with second-order rate constants similar to those of tyrosine. However, we noticed that tempol inhibits the chlorinating activity of MPO, in contrast with tyrosine. Thus we studied the inhibition of MPO-mediated taurine chlorination by tempol at pH 7.4 and re-determined the kinetic constants of the reactions of tempol with MPO-I (k=3.5×105 M−1·s−1) and MPO-II, the kinetics of which indicated a binding interaction (K=2.0×10−5 M; k=3.6×10−2 s−1). Also, we showed that tempol reacts extremely slowly with hypochlorous acid (k=0.29 and 0.054 M−1·s−1 at pH 5.4 and 7.4 respectively). The results demonstrated that tempol acts mostly as a reversible inhibitor of MPO by trapping it as MPO-II and the MPO-II–tempol complex, which are not within the chlorinating cycle. After turnover, a minor fraction of MPO is irreversibly inactivated, probably due to its reaction with the oxammonium cation resulting from tempol oxidation. Kinetic modelling indicated that taurine reacts with enzyme-bound hypochlorous acid. Our investigation complements a comprehensive study reported while the present study was underway [Rees, Bottle, Fairfull-Smith, Malle, Whitelock and Davies (2009) Biochem. J. 421, 79–86].
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Abstract
Photo-induced damage to proteins occurs via multiple pathways. Direct damage induced by UVB (λ 280-320 nm) and UVA radiation (λ 320-400 nm) is limited to a small number of amino acid residues, principally tryptophan (Trp), tyrosine (Tyr), histidine (His) and disulfide (cystine) residues, with this occurring via both excited state species and radicals. Indirect protein damage can occur via singlet oxygen ((1)O(2)(1)Δ(g)), with this resulting in damage to Trp, Tyr, His, cystine, cysteine (Cys) and methionine (Met) residues. Although initial damage is limited to these residues multiple secondary processes, that occur both during and after radiation exposure, can result in damage to other intra- and inter-molecular sites. Secondary damage can arise via radicals (e.g. Trp, Tyr and Cys radicals), from reactive intermediates generated by (1)O(2) (e.g. Trp, Tyr and His peroxides) and via molecular reactions of photo-products (e.g. reactive carbonyls). These processes can result in protein fragmentation, aggregation, altered physical and chemical properties (e.g. hydrophobicity and charge) and modulated biological turnover. Accumulating evidence implicates these events in cellular and tissue dysfunction (e.g. apoptosis, necrosis and altered cell signaling), and multiple human pathologies.
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Affiliation(s)
- David I Pattison
- The Heart Research Institute, 7 Eliza Street, Newtown, Sydney, NSW 2042, Australia
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Nitric oxide and quality and safety of muscle based foods. Nitric Oxide 2011; 24:176-83. [DOI: 10.1016/j.niox.2011.03.307] [Citation(s) in RCA: 123] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2010] [Revised: 03/16/2011] [Accepted: 03/24/2011] [Indexed: 11/18/2022]
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44
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Kálai T, Petrlova J, Balog M, Aung HH, Voss JC, Hideg K. Synthesis and study of 2-amino-7-bromofluorenes modified with nitroxides and their precursors as dual anti-amyloid and antioxidant active compounds. Eur J Med Chem 2011; 46:1348-55. [PMID: 21333407 DOI: 10.1016/j.ejmech.2011.01.059] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2010] [Revised: 01/14/2011] [Accepted: 01/26/2011] [Indexed: 11/18/2022]
Abstract
A series of 2-aminofluorenes N-alkylated with nitroxides or their precursors were synthesized. The new compounds were tested on hydroxyl radical and peroxyl radical scavenging ability and inflammatory assay on the endothelial brain cells. In agreement with ROS scavenging ability the same compound 7-bromo-N -[(1-Oxyl-2,2,6,6-tetramethyl-1,2,3,6-tetrahydropyridine-4yl)methyl]-9H-fluoren-2-amine (3b) and its hydroxylamine salt (3b/OH/HCl) showed the anti-inflammatory property on the endothelial brain cells.
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Affiliation(s)
- Tamás Kálai
- Institute of Organic and Medicinal Chemistry, University of Pécs, Szigeti st 12, H-7624 Pécs, Hungary
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45
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Szabo A, Balog M, Mark L, Montsko G, Turi Z, Gallyas F, Sumegi B, Kalai T, Hideg K, Kovacs K. Induction of mitochondrial destabilization and necrotic cell death by apolar mitochondria-directed SOD mimetics. Mitochondrion 2011; 11:476-87. [PMID: 21292036 DOI: 10.1016/j.mito.2011.01.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2010] [Revised: 01/06/2011] [Accepted: 01/24/2011] [Indexed: 01/14/2023]
Abstract
In this paper, we present evidence, for the first time, that increasing the lipophilicity of mitochondria targeting SOD mimetics reverses their cytoprotective properties, destabilizing the mitochondrial membrane system and promoting cell death. A new mitochondria-directed apolar SOD mimetic, HO-3814, was found to provoke mitochondrial swelling and loss of mitochondrial membrane potential, and these effects were not inhibited by cyclosporine A. HO-3814-induced cell death was predominantly necrotic, caspase-independent, and not affected by mitochondrial permeability transition inhibitors or cyclophilin D-suppression, inhibitors of mitogen-activated protein kinases or Akt, or various antioxidants. In contrast, Bcl-2 overexpression diminished the effects of HO-3814.
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Affiliation(s)
- Aliz Szabo
- Department of Biochemistry and Medical Chemistry, University of Pecs, Hungary
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46
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Barlow CK, Wright A, Easton CJ, O'Hair RAJ. Gas-phase ion-molecule reactions using regioselectively generated radical cations to model oxidative damage and probe radical sites in peptides. Org Biomol Chem 2011; 9:3733-45. [DOI: 10.1039/c0ob01245a] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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47
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Rahmanto AS, Morgan PE, Hawkins CL, Davies MJ. Cellular effects of photogenerated oxidants and long-lived, reactive, hydroperoxide photoproducts. Free Radic Biol Med 2010; 49:1505-15. [PMID: 20708682 DOI: 10.1016/j.freeradbiomed.2010.08.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2010] [Revised: 08/02/2010] [Accepted: 08/05/2010] [Indexed: 11/22/2022]
Abstract
Reaction of radicals and singlet oxygen ((1)O(2)) with proteins results in both direct damage and the formation of long-lived reactive hydroperoxides. Elevated levels of protein hydroperoxide-derived products have been detected in multiple human pathologies, suggesting that these secondary oxidants contribute to tissue damage. Previous studies have provided evidence for protein hydroperoxide-mediated inhibition of thiol-dependent enzymes and modulation of signaling processes in isolated systems. In this study (1)O(2) and hydroperoxides have been generated in J774A.1 macrophage-like cells using visible light and the photosensitizer rose bengal, with the consequences of oxidant formation examined both immediately and after subsequent (dark-phase) incubation. Significant losses of GSH (≤50%), total thiols (≤20%), and activity of thiol-dependent proteins (GAPDH, thioredoxin, protein tyrosine phosphatases, creatine kinase, and cathepsins B and L; 10-50% inhibition) were detected after 1 or 2 min photo-oxidation. Non-thiol-dependent enzymes were not affected. In contrast, NADPH levels increased, together with the activity of glutathione reductase, glutathione peroxidase, and thioredoxin reductase; these increases may be components of a rapid global cytoprotective cellular response to stress. Neither oxidized thioredoxin nor radical-mediated protein oxidation products were detected at significant levels. Further decreases in thiol levels and enzyme activity occurred during dark-phase incubation, with this accompanied by decreased cell viability. These secondary events are ascribed to the reactions of long-lived hydroperoxides, generated by (1)O(2)-mediated reactions. Overall, this study provides novel insights into early cellular responses to photo-oxidative damage and indicates that long-lived hydroperoxides can play a significant role in cellular damage.
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Batinić-Haberle I, Rebouças JS, Spasojević I. Superoxide dismutase mimics: chemistry, pharmacology, and therapeutic potential. Antioxid Redox Signal 2010; 13:877-918. [PMID: 20095865 PMCID: PMC2935339 DOI: 10.1089/ars.2009.2876] [Citation(s) in RCA: 388] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Oxidative stress has become widely viewed as an underlying condition in a number of diseases, such as ischemia-reperfusion disorders, central nervous system disorders, cardiovascular conditions, cancer, and diabetes. Thus, natural and synthetic antioxidants have been actively sought. Superoxide dismutase is a first line of defense against oxidative stress under physiological and pathological conditions. Therefore, the development of therapeutics aimed at mimicking superoxide dismutase was a natural maneuver. Metalloporphyrins, as well as Mn cyclic polyamines, Mn salen derivatives and nitroxides were all originally developed as SOD mimics. The same thermodynamic and electrostatic properties that make them potent SOD mimics may allow them to reduce other reactive species such as peroxynitrite, peroxynitrite-derived CO(3)(*-), peroxyl radical, and less efficiently H(2)O(2). By doing so SOD mimics can decrease both primary and secondary oxidative events, the latter arising from the inhibition of cellular transcriptional activity. To better judge the therapeutic potential and the advantage of one over the other type of compound, comparative studies of different classes of drugs in the same cellular and/or animal models are needed. We here provide a comprehensive overview of the chemical properties and some in vivo effects observed with various classes of compounds with a special emphasis on porphyrin-based compounds.
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Affiliation(s)
- Ines Batinić-Haberle
- Department of Radiation Oncology, Duke University Medical School, Durham, North Carolina 27710, USA.
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49
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Tsuhako MH, Augusto O, Linares E, Chadi G, Giorgio S, Pereira CA. Tempol ameliorates murine viral encephalomyelitis by preserving the blood-brain barrier, reducing viral load, and lessening inflammation. Free Radic Biol Med 2010; 48:704-12. [PMID: 20035861 PMCID: PMC7126783 DOI: 10.1016/j.freeradbiomed.2009.12.013] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2009] [Revised: 12/09/2009] [Accepted: 12/16/2009] [Indexed: 12/21/2022]
Abstract
Multiple sclerosis (MS) is a progressive inflammatory and/or demyelinating disease of the human central nervous system (CNS). Most of the knowledge about the pathogenesis of MS has been derived from murine models, such as experimental autoimmune encephalomyelitis and viral encephalomyelitis. Here, we infected female C57BL/6 mice with a neurotropic strain of the mouse hepatitis virus (MHV-59A) to evaluate whether treatment with the multifunctional antioxidant tempol (4-hydroxy-2,2,6,6-tetramethyl-1-piperidinyloxy) affects the ensuing encephalomyelitis. In untreated animals, neurological symptoms developed quickly: 90% of infected mice died 10 days after virus inoculation and the few survivors presented neurological deficits. Treatment with tempol (24 mg/kg, ip, two doses on the first day and daily doses for 7 days plus 2 mM tempol in the drinking water ad libitum) profoundly altered the disease outcome: neurological symptoms were attenuated, mouse survival increased up to 70%, and half of the survivors behaved as normal mice. Not surprisingly, tempol substantially preserved the integrity of the CNS, including the blood-brain barrier. Furthermore, treatment with tempol decreased CNS viral titers, macrophage and T lymphocyte infiltration, and levels of markers of inflammation, such as expression of inducible nitric oxide synthase, transcription of tumor necrosis factor-alpha and interferon-gamma, and protein nitration. The results indicate that tempol ameliorates murine viral encephalomyelitis by altering the redox status of the infectious environment that contributes to an attenuated CNS inflammatory response. Overall, our study supports the development of therapeutic strategies based on nitroxides to manage neuroinflammatory diseases, including MS.
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Key Words
- bbb, blood–brain barrier
- cns, central nervous system
- eae, experimental autoimmune encephalomyelitis
- ifn-γ, interferon-γ
- mhv, mouse hepatitis virus
- ms, multiple sclerosis
- inos, inducible nitric oxide synthase
- tempol, 4-hydroxy-2,2,6,6,-tetramethyl-1-piperidinyloxy
- tnf-α, tumor necrosis factor-α
- multiple sclerosis
- encephalomyelitis
- mouse hepatitis virus
- tempol
- antioxidant
- anti-inflammatory
- inflammation
- redox status
- nitric oxide-derived oxidants
- free radicals
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Affiliation(s)
- Maria Heloisa Tsuhako
- Laboratório de Imunologia Viral, Instituto Butantan, 05503-900 São Paulo, Brazil
- Corresponding authors. M.H. Tsuhako is to be contacted at fax: +55 11 37261505. O. Augusto, fax: +55 11 30912186.
| | - Ohara Augusto
- Instituto de Química, Departamento de Bioquímica, Department of Neurology, School of Medicine, Universidade de São Paulo, 05513-970 São Paulo, Brazil
- Corresponding authors. M.H. Tsuhako is to be contacted at fax: +55 11 37261505. O. Augusto, fax: +55 11 30912186.
| | - Edlaine Linares
- Instituto de Química, Departamento de Bioquímica, Department of Neurology, School of Medicine, Universidade de São Paulo, 05513-970 São Paulo, Brazil
| | - Gerson Chadi
- Neuroregeneration Center, Department of Neurology, School of Medicine, Universidade de São Paulo, 05513-970 São Paulo, Brazil
| | - Selma Giorgio
- Departamento de Biologia Animal, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, Brazil
| | - Carlos A. Pereira
- Laboratório de Imunologia Viral, Instituto Butantan, 05503-900 São Paulo, Brazil
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50
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Lardinois OM, Maltby DA, Medzihradszky KF, de Montellano PRO, Tomer KB, Mason RP, Deterding LJ. Spin scavenging analysis of myoglobin protein-centered radicals using stable nitroxide radicals: characterization of oxoammonium cation-induced modifications. Chem Res Toxicol 2009; 22:1034-49. [PMID: 19449826 DOI: 10.1021/tx9000094] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Spin scavenging combined with chromatographic and mass spectrometric procedures can, in principle, be employed to detect and identify protein-based radicals within complex biological matrices. This approach is based on the well-known ability of stable synthetic nitroxide radicals to scavenge carbon-centered radicals, forming stable diamagnetic addition products. Hence, characterization of these addition products would allow for the identification of specific free radicals. In the present work, we have explored the use of the stable nitroxide radical 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPOL) in scavenging protein-based radicals generated in a horse heart metmyoglobin/hydrogen peroxide (metMb/H(2)O(2)) system. Inclusion of a substoichiometric amount of TEMPOL in the metMb/H(2)O(2) system resulted in a complete loss of peroxyl and tyrosyl radical signals and effectively inhibited the formation of oxidatively damaged heme species, as monitored by electron paramagnetic resonance and reversed-phase liquid chromatography. Scavenging of globin radicals by TEMPOL did not lead to the formation of stable diamagnetic addition adducts; in fact, reversed-phase liquid chromatographic studies and oxygen electrode measurements indicated that TEMPOL acts as a catalyst and is recycled in this system. The oxoammonium cation generated in the course of this reaction initiated secondary reactions resulting in the formation of a free carbonyl on the N-terminal Gly-residue of the protein. This oxidative deamination was confirmed through the combined use of reversed-phase liquid chromatographic purification, tandem MS experiments, and chemical analysis (e.g., by use of 2,4-dinitrophenyl hydrazine). The results reveal the pitfalls inherent in using stable nitroxide radicals such as TEMPOL to identify sites of radical formation on hemoproteins.
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Affiliation(s)
- Olivier M Lardinois
- Laboratories of Pharmacology and Structural Biology, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709, USA.
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