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Antibacterial Activity of Synthetic Cationic Iron Porphyrins. Antioxidants (Basel) 2020; 9:antiox9100972. [PMID: 33050461 PMCID: PMC7601463 DOI: 10.3390/antiox9100972] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 09/15/2020] [Accepted: 09/17/2020] [Indexed: 12/28/2022] Open
Abstract
Widespread antibiotic resistance demands new strategies for fighting infections. Porphyrin-based compounds were long ago introduced as photosensitizers for photodynamic therapy, but light-independent antimicrobial activity of such compounds has not been systematically explored. The results of this study demonstrate that synthetic cationic amphiphilic iron N-alkylpyridylporphyrins exert strong bactericidal action at concentrations as low as 5 μM. Iron porphyrin, FeTnHex-2-PyP, which is well tolerated by laboratory animals, efficiently killed Gram-negative and Gram-positive microorganisms. Its bactericidal activity was oxygen-independent and was controlled by the lipophilicity and accumulation of the compound in bacterial cells. Such behavior is in contrast with the anionic gallium protoporphyrin IX, whose efficacy depends on cellular heme uptake systems. Under aerobic conditions, however, the activity of FeTnHex-2-PyP was limited by its destruction due to redox-cycling. Neither iron released from the Fe-porphyrin nor other decomposition products were the cause of the bactericidal activity. FeTnHex-2-PyP was as efficient against antibiotic-sensitive E. coli and S. aureus as against their antibiotic-resistant counterparts. Our data demonstrate that development of amphiphilic, positively charged metalloporphyrins might be a promising approach in the introduction of new weapons against antibiotic-resistant strains.
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Franke A, Scheitler A, Kenkel I, Lippert R, Zahl A, Balbinot D, Jux N, Ivanović-Burmazović I. Positive Charge on Porphyrin Ligand and Nature of Metal Center Define Basic Physicochemical Properties of Cationic Manganese and Iron Porphyrins in Aqueous Solution. Inorg Chem 2019; 58:9618-9630. [DOI: 10.1021/acs.inorgchem.8b03381] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Alicja Franke
- Department of Chemistry and Pharmacy, University Erlangen−Nuremberg, 91058 Erlangen, Germany
| | - Andreas Scheitler
- Department of Chemistry and Pharmacy, University Erlangen−Nuremberg, 91058 Erlangen, Germany
| | - Isabell Kenkel
- Department of Chemistry and Pharmacy, University Erlangen−Nuremberg, 91058 Erlangen, Germany
| | - Rainer Lippert
- Department of Chemistry and Pharmacy, University Erlangen−Nuremberg, 91058 Erlangen, Germany
| | - Achim Zahl
- Department of Chemistry and Pharmacy, University Erlangen−Nuremberg, 91058 Erlangen, Germany
| | - Domenico Balbinot
- Department of Chemistry and Pharmacy, University Erlangen−Nuremberg, 91058 Erlangen, Germany
| | - Norbert Jux
- Department of Chemistry and Pharmacy, University Erlangen−Nuremberg, 91058 Erlangen, Germany
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Batinic-Haberle I, Tovmasyan A, Spasojevic I. Mn Porphyrin-Based Redox-Active Drugs: Differential Effects as Cancer Therapeutics and Protectors of Normal Tissue Against Oxidative Injury. Antioxid Redox Signal 2018; 29:1691-1724. [PMID: 29926755 PMCID: PMC6207162 DOI: 10.1089/ars.2017.7453] [Citation(s) in RCA: 94] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
SIGNIFICANCE After approximatelty three decades of research, two Mn(III) porphyrins (MnPs), MnTE-2-PyP5+ (BMX-010, AEOL10113) and MnTnBuOE-2-PyP5+ (BMX-001), have progressed to five clinical trials. In parallel, another similarly potent metal-based superoxide dismutase (SOD) mimic-Mn(II)pentaaza macrocycle, GC4419-has been tested in clinical trial on application, identical to that of MnTnBuOE-2-PyP5+-radioprotection of normal tissue in head and neck cancer patients. This clearly indicates that Mn complexes that target cellular redox environment have reached sufficient maturity for clinical applications. Recent Advances: While originally developed as SOD mimics, MnPs undergo intricate interactions with numerous redox-sensitive pathways, such as those involving nuclear factor κB (NF-κB) and nuclear factor E2-related factor 2 (Nrf2), thereby impacting cellular transcriptional activity. An increasing amount of data support the notion that MnP/H2O2/glutathione (GSH)-driven catalysis of S-glutathionylation of protein cysteine, associated with modification of protein function, is a major action of MnPs on molecular level. CRITICAL ISSUES Differential effects of MnPs on normal versus tumor cells/tissues, which support their translation into clinic, arise from differences in their accumulation and redox environment of such tissues. This in turn results in different yields of MnP-driven modifications of proteins. Thus far, direct evidence for such modification of NF-κB, mitogen-activated protein kinases (MAPK), phosphatases, Nrf2, and endogenous antioxidative defenses was provided in tumor, while indirect evidence shows the modification of NF-κB and Nrf2 translational activities by MnPs in normal tissue. FUTURE DIRECTIONS Studies that simultaneously explore differential effects in same animal are lacking, while they are essential for understanding of extremely intricate interactions of metal-based drugs with complex cellular networks of normal and cancer cells/tissues.
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Affiliation(s)
- Ines Batinic-Haberle
- 1 Department of Radiation Oncology, Duke University School of Medicine , Durham, North Carolina
| | - Artak Tovmasyan
- 1 Department of Radiation Oncology, Duke University School of Medicine , Durham, North Carolina
| | - Ivan Spasojevic
- 2 Department of Medicine, Duke University School of Medicine , Durham, North Carolina.,3 PK/PD Core Laboratory, Pharmaceutical Research Shared Resource, Duke Cancer Institute , Durham, North Carolina
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Carballal S, Valez V, Alvarez-Paggi D, Tovmasyan A, Batinic-Haberle I, Ferrer-Sueta G, Murgida DH, Radi R. Manganese porphyrin redox state in endothelial cells: Resonance Raman studies and implications for antioxidant protection towards peroxynitrite. Free Radic Biol Med 2018; 126:379-392. [PMID: 30144631 DOI: 10.1016/j.freeradbiomed.2018.08.023] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2018] [Revised: 08/18/2018] [Accepted: 08/20/2018] [Indexed: 10/28/2022]
Abstract
Cationic manganese(III) ortho N-substituted pyridylporphyrins (MnP) act as efficient antioxidants catalyzing superoxide dismutation and accelerating peroxynitrite reduction. Importantly, MnP can reach mitochondria offering protection against reactive species in different animal models of disease. Although an LC-MS/MS-based method for MnP quantitation and subcellular distribution has been reported, a direct method capable of evaluating both the uptake and the redox state of MnP in living cells has not yet been developed. In the present work we applied resonance Raman (RR) spectroscopy to analyze the intracellular accumulation of two potent MnP-based lipophilic SOD mimics, MnTnBuOE-2-PyP5+ and MnTnHex-2-PyP5+ within endothelial cells. RR experiments with isolated mitochondria revealed that the reduction of Mn(III)P was affected by inhibitors of the electron transport chain, supporting the action of MnP as efficient redox active compounds in mitochondria. Indeed, RR spectra confirmed that MnP added in the Mn(III) state can be incorporated into the cells, readily reduced by intracellular components to the Mn(II) state and oxidized by peroxynitrite. To assess the combined impact of reactivity and bioavailability, we studied the kinetics of Mn(III)TnBuOE-2-PyP5+ with peroxynitrite and evaluated the cytoprotective capacity of MnP by exposing the endothelial cells to nitro-oxidative stress induced by peroxynitrite. We observed a preservation of normal mitochondrial function, attenuation of cell damage and prevention of apoptotic cell death. These data introduce a novel application of RR spectroscopy for the direct detection of MnP and their redox states inside living cells, and helps to rationalize their antioxidant capacity in biological systems.
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Affiliation(s)
- Sebastián Carballal
- Departmento de Bioquímica, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay; Center for Free Radical and Biomedical Research, Universidad de la República, Montevideo, Uruguay
| | - Valeria Valez
- Departmento de Bioquímica, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay; Center for Free Radical and Biomedical Research, Universidad de la República, Montevideo, Uruguay
| | - Damián Alvarez-Paggi
- Departamento de Química Inorgánica, Analítica y Química Física and INQUIMAE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pab. 2, piso 1, C1428EHA Buenos Aires, Argentina
| | - Artak Tovmasyan
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710, USA
| | - Ines Batinic-Haberle
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710, USA
| | - Gerardo Ferrer-Sueta
- Center for Free Radical and Biomedical Research, Universidad de la República, Montevideo, Uruguay; Laboratorio de Fisicoquímica Biológica, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Daniel H Murgida
- Departamento de Química Inorgánica, Analítica y Química Física and INQUIMAE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pab. 2, piso 1, C1428EHA Buenos Aires, Argentina
| | - Rafael Radi
- Departmento de Bioquímica, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay; Center for Free Radical and Biomedical Research, Universidad de la República, Montevideo, Uruguay.
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Redox behavior and biological properties of ferrocene bearing porphyrins. J Inorg Biochem 2017; 171:76-89. [DOI: 10.1016/j.jinorgbio.2017.03.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Revised: 03/09/2017] [Accepted: 03/21/2017] [Indexed: 02/01/2023]
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Rajic Z, Tovmasyan A, de Santana OL, Peixoto IN, Spasojevic I, do Monte SA, Ventura E, Rebouças JS, Batinic-Haberle I. Challenges encountered during development of Mn porphyrin-based, potent redox-active drug and superoxide dismutase mimic, MnTnBuOE-2-PyP 5+, and its alkoxyalkyl analogues. J Inorg Biochem 2017; 169:50-60. [PMID: 28131001 DOI: 10.1016/j.jinorgbio.2017.01.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 12/21/2016] [Accepted: 01/03/2017] [Indexed: 11/28/2022]
Abstract
We disclose here the studies that preceded and guided the preparation of the metal-based, redox-active therapeutic Mn(III) meso-tetrakis(N-n-butoxyethylpyridyl)porphyrin, MnTnBuOE-2-PyP5+ (BMX-001), which is currently in Phase I/II Clinical Trials at Duke University (USA) as a radioprotector of normal tissues in cancer patients. N-substituted pyridylporphyrins are ligands for Mn(III) complexes that are among the most potent superoxide dismutase mimics thus far synthesized. To advance their design, thereby improving their physical and chemical properties and bioavailability/toxicity profiles, we undertook a systematic study on placing oxygen atoms into N-alkylpyridyl chains via alkoxyalkylation reaction. For the first time we show here the unforeseen structural rearrangement that happens during the alkoxyalkylation reaction by the corresponding tosylates. Comprehensive experimental and computational approaches were employed to solve the rearrangement mechanism involved in quaternization of pyridyl nitrogens, which, instead of a single product, led to a variety of mixed N-alkoxyalkylated and N-alkylated pyridylporphyrins. The rearrangement mechanism involves the formation of an intermediate alkyl oxonium cation in a chain-length-dependent manner, which subsequently drives differential kinetics and thermodynamics of competing N-alkoxyalkylation versus in situ N-alkylation. The use of alkoxyalkyl tosylates, of different length of alkyl fragments adjacent to oxygen atom, allowed us to identify the set of alkyl fragments that would result in the synthesis of a single compound of high purity and excellent therapeutic potential.
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Affiliation(s)
- Zrinka Rajic
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710, USA
| | - Artak Tovmasyan
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710, USA
| | - Otávio L de Santana
- Departamento de Química, CCEN, Universidade Federal da Paraiba, João Pessoa, PB 58051-900, Brazil
| | - Isabelle N Peixoto
- Departamento de Química, CCEN, Universidade Federal da Paraiba, João Pessoa, PB 58051-900, Brazil
| | - Ivan Spasojevic
- Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA; Duke Cancer Institute, Pharmaceutical Research Shared Resource, PK/PD Core Laboratory, Durham, NC 27710, United States
| | - Silmar A do Monte
- Departamento de Química, CCEN, Universidade Federal da Paraiba, João Pessoa, PB 58051-900, Brazil
| | - Elizete Ventura
- Departamento de Química, CCEN, Universidade Federal da Paraiba, João Pessoa, PB 58051-900, Brazil
| | - Júlio S Rebouças
- Departamento de Química, CCEN, Universidade Federal da Paraiba, João Pessoa, PB 58051-900, Brazil.
| | - Ines Batinic-Haberle
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710, USA.
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Mn Porphyrin-Based Redox-Active Therapeutics. OXIDATIVE STRESS IN APPLIED BASIC RESEARCH AND CLINICAL PRACTICE 2016. [DOI: 10.1007/978-3-319-30705-3_8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Tovmasyan A, Sampaio RS, Boss MK, Bueno-Janice JC, Bader BH, Thomas M, Reboucas JS, Orr M, Chandler JD, Go YM, Jones DP, Venkatraman TN, Haberle S, Kyui N, Lascola CD, Dewhirst MW, Spasojevic I, Benov L, Batinic-Haberle I. Anticancer therapeutic potential of Mn porphyrin/ascorbate system. Free Radic Biol Med 2015; 89:1231-47. [PMID: 26496207 PMCID: PMC4684782 DOI: 10.1016/j.freeradbiomed.2015.10.416] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Revised: 10/05/2015] [Accepted: 10/18/2015] [Indexed: 01/12/2023]
Abstract
Ascorbate (Asc) as a single agent suppressed growth of several tumor cell lines in a mouse model. It has been tested in a Phase I Clinical Trial on pancreatic cancer patients where it exhibited no toxicity to normal tissue yet was of only marginal efficacy. The mechanism of its anticancer effect was attributed to the production of tumoricidal hydrogen peroxide (H2O2) during ascorbate oxidation catalyzed by endogenous metalloproteins. The amount of H2O2 could be maximized with exogenous catalyst that has optimized properties for such function and is localized within tumor. Herein we studied 14 Mn porphyrins (MnPs) which differ vastly with regards to their redox properties, charge, size/bulkiness and lipophilicity. Such properties affect the in vitro and in vivo ability of MnPs (i) to catalyze ascorbate oxidation resulting in the production of H2O2; (ii) to subsequently employ H2O2 in the catalysis of signaling proteins oxidations affecting cellular survival pathways; and (iii) to accumulate at site(s) of interest. The metal-centered reduction potential of MnPs studied, E1/2 of Mn(III)P/Mn(II)P redox couple, ranged from -200 to +350 mV vs NHE. Anionic and cationic, hydrophilic and lipophilic as well as short- and long-chained and bulky compounds were explored. Their ability to catalyze ascorbate oxidation, and in turn cytotoxic H2O2 production, was explored via spectrophotometric and electrochemical means. Bell-shape structure-activity relationship (SAR) was found between the initial rate for the catalysis of ascorbate oxidation, vo(Asc)ox and E1/2, identifying cationic Mn(III) N-substituted pyridylporphyrins with E1/2>0 mV vs NHE as efficient catalysts for ascorbate oxidation. The anticancer potential of MnPs/Asc system was subsequently tested in cellular (human MCF-7, MDA-MB-231 and mouse 4T1) and animal models of breast cancer. At the concentrations where ascorbate (1mM) and MnPs (1 or 5 µM) alone did not trigger any alteration in cell viability, combined treatment suppressed cell viability up to 95%. No toxicity was observed with normal human breast epithelial HBL-100 cells. Bell-shape relationship, essentially identical to vo(Asc)oxvs E1/2, was also demonstrated between MnP/Asc-controlled cytotoxicity and E1/2-controlled vo(Asc)ox. Magnetic resonance imaging studies were conducted to explore the impact of ascorbate on T1-relaxivity. The impact of MnP/Asc on intracellular thiols and on GSH/GSSG and Cys/CySS ratios in 4T1 cells was assessed and cellular reduction potentials were calculated. The data indicate a significant increase in cellular oxidative stress induced by MnP/Asc. Based on vo(Asc)oxvs E1/2 relationships and cellular toxicity, MnTE-2-PyP(5+) was identified as the best catalyst among MnPs studied. Asc and MnTE-2-PyP(5+) were thus tested in a 4T1 mammary mouse flank tumor model. The combination of ascorbate (4 g/kg) and MnTE-2-PyP(5+) (0.2mg/kg) showed significant suppression of tumor growth relative to either MnTE-2-PyP(5+) or ascorbate alone. About 7-fold higher accumulation of MnTE-2-PyP(5+) in tumor vs normal tissue was found to contribute largely to the anticancer effect.
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Affiliation(s)
- Artak Tovmasyan
- Department of Radiation Oncology, Duke University School of Medicine, Durham, NC 27710, United States
| | - Romulo S Sampaio
- Department of Radiation Oncology, Duke University School of Medicine, Durham, NC 27710, United States; Departamento de Quimica, CCEN, Universidade Federal da Paraiba, Joao Pessoa, PB 58051-900, Brazil
| | - Mary-Keara Boss
- Department of Molecular Biomedical Sciences, North Carolina State University College of Veterinary Medicine, Raleigh, NC 27607, United States
| | - Jacqueline C Bueno-Janice
- Department of Radiation Oncology, Duke University School of Medicine, Durham, NC 27710, United States; Departamento de Quimica, CCEN, Universidade Federal da Paraiba, Joao Pessoa, PB 58051-900, Brazil
| | - Bader H Bader
- Department of Biochemistry, Faculty of Medicine, Kuwait University, Kuwait
| | - Milini Thomas
- Department of Biochemistry, Faculty of Medicine, Kuwait University, Kuwait
| | - Julio S Reboucas
- Departamento de Quimica, CCEN, Universidade Federal da Paraiba, Joao Pessoa, PB 58051-900, Brazil
| | - Michael Orr
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, Emory University, Atlanta, GA, United States
| | - Joshua D Chandler
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, Emory University, Atlanta, GA, United States
| | - Young-Mi Go
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, Emory University, Atlanta, GA, United States
| | - Dean P Jones
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, Emory University, Atlanta, GA, United States
| | | | - Sinisa Haberle
- Department of Radiology, Duke University School of Medicine, Durham, NC 27710, United States
| | - Natalia Kyui
- Canadian Economic Analysis Department, Bank of Canada, Ottawa, ON K1A 0G9, Canada
| | - Christopher D Lascola
- Department of Radiology, Duke University School of Medicine, Durham, NC 27710, United States
| | - Mark W Dewhirst
- Department of Radiation Oncology, Duke University School of Medicine, Durham, NC 27710, United States
| | - Ivan Spasojevic
- Department of Medicine, Duke University School of Medicine, Durham, NC 27710, United States; Duke Cancer Institute, Pharmaceutical Research Shared Resource, PK/PD Core laboratory, Durham NC 27710, United States
| | - Ludmil Benov
- Department of Biochemistry, Faculty of Medicine, Kuwait University, Kuwait
| | - Ines Batinic-Haberle
- Department of Radiation Oncology, Duke University School of Medicine, Durham, NC 27710, United States.
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Slosky LM, Vanderah TW. Therapeutic potential of peroxynitrite decomposition catalysts: a patent review. Expert Opin Ther Pat 2015; 25:443-66. [PMID: 25576197 DOI: 10.1517/13543776.2014.1000862] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
INTRODUCTION Peroxynitrite is a cytotoxic oxidant species implicated in a host of pathologies, including inflammatory and neurodegenerative diseases, cancer, radiation injury and chronic pain. With the recognition of the role of peroxynitrite in disease, numerous experimental and therapeutic tools have arisen to probe peroxyntirite's pathophysiological contribution and attenuate its oxidative damage. Peroxynitrite decomposition catalysts (PNDCs) are redox-active compounds that detoxify peroxynitrite by catalyzing its isomerization or reduction to nitrate or nitrite. AREAS COVERED This review discusses recent research articles and patents published 1995 - 2014 on the development and therapeutic use of PNDCs. Iron and manganese metalloporphyrin PNDCs attenuate the toxic effects of peroxynitrite and are currently being developed for clinical applications. Additionally, some Mn porphyrin-based PNDCs have optimized pharmaceutical properties such that they exhibit greater peroxynitrite selectivity. Other classes of PNDC agents, including bis(hydroxyphenyl)dipyrromethenes and metallocorroles, have demonstrated preclinical efficacy, oral availability and reduced toxicity risk. EXPERT OPINION Interest in the drug-like properties of peroxynitrite-neutralizing agents has grown with the realization that PNDCs will be powerful tools in the treatment of disease. The design of compounds with enhanced oral availability and peroxynitrite selectivity is a critical step toward the availability of safe, effective and selective redox modulators for the treatment of peroxynitrite-associated pathologies.
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Affiliation(s)
- Lauren M Slosky
- University of Arizona, Department of Pharmacology , Life Science North Rm 621, 1501 North Campbell Ave., Tucson, AZ 85721 , USA
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Grubman A, White AR, Liddell JR. Mitochondrial metals as a potential therapeutic target in neurodegeneration. Br J Pharmacol 2014; 171:2159-73. [PMID: 24206195 DOI: 10.1111/bph.12513] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2013] [Revised: 10/29/2013] [Accepted: 10/30/2013] [Indexed: 12/22/2022] Open
Abstract
Transition metals are critical for enzyme function and protein folding, but in excess can mediate neurotoxic oxidative processes. As mitochondria are particularly vulnerable to oxidative damage due to radicals generated during ATP production, mitochondrial biometal homeostasis must therefore be tightly controlled to safely harness the redox potential of metal enzyme cofactors. Dysregulation of metal functions is evident in numerous neurological disorders including Alzheimer's disease, stroke, Parkinson's disease, Huntington's disease, amyotrophic lateral sclerosis and Friedrich's ataxia. This review describes the mitochondrial metal defects in these disorders and highlights novel metal-based therapeutic approaches that target mitochondrial metal homeostasis in neurological disorders.
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Affiliation(s)
- A Grubman
- Department of Pathology, University of Melbourne, Melbourne, Vic., Australia
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Leung CH, Lin S, Zhong HJ, Ma DL. Metal complexes as potential modulators of inflammatory and autoimmune responses. Chem Sci 2014; 6:871-884. [PMID: 28660015 PMCID: PMC5472922 DOI: 10.1039/c4sc03094j] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Accepted: 11/07/2014] [Indexed: 01/05/2023] Open
Abstract
In this perspective, we highlight recent examples in the development of transition metal complexes as modulators of inflammatory and autoimmune responses.
Over the past few decades, the realm of inorganic medicinal chemistry has been dominated by the study of the anti-cancer properties of transition metal complexes, particularly those based on platinum or ruthenium. However, comparatively less attention has been focused on the development of metal complexes for the treatment of inflammatory or autoimmune diseases. Metal complexes possess a number of advantages that render them as attractive alternatives to organic small molecules for the development of therapeutic agents. In this perspective, we highlight recent examples in the development of transition metal complexes as modulators of inflammatory and autoimmune responses. The studies presented here serve to highlight the potential of transition metal complexes in modulating inflammatory or immune pathways in cells.
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Affiliation(s)
- Chung-Hang Leung
- State Key Laboratory of Quality Research in Chinese Medicine , Institute of Chinese Medical Sciences , University of Macau , Macao , China .
| | - Sheng Lin
- Department of Chemistry , Hong Kong Baptist University , Kowloon Tong , Hong Kong , China .
| | - Hai-Jing Zhong
- State Key Laboratory of Quality Research in Chinese Medicine , Institute of Chinese Medical Sciences , University of Macau , Macao , China .
| | - Dik-Lung Ma
- Department of Chemistry , Hong Kong Baptist University , Kowloon Tong , Hong Kong , China .
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Tovmasyan A, Carballal S, Ghazaryan R, Melikyan L, Weitner T, Maia CC, Reboucas JS, Radi R, Spasojevic I, Benov L, Batinic-Haberle I. Rational design of superoxide dismutase (SOD) mimics: the evaluation of the therapeutic potential of new cationic Mn porphyrins with linear and cyclic substituents. Inorg Chem 2014; 53:11467-83. [PMID: 25333724 PMCID: PMC4220860 DOI: 10.1021/ic501329p] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Indexed: 02/06/2023]
Abstract
Our goal herein has been to gain further insight into the parameters which control porphyrin therapeutic potential. Mn porphyrins (MnTnOct-2-PyP(5+), MnTnHexOE-2-PyP(5+), MnTE-2-PyPhP(5+), and MnTPhE-2-PyP(5+)) that bear the same positive charge and same number of carbon atoms at meso positions of porphyrin core were explored. The carbon atoms of their meso substituents are organized to form either linear or cyclic structures of vastly different redox properties, bulkiness, and lipophilicities. These Mn porphyrins were compared to frequently studied compounds, MnTE-2-PyP(5+), MnTE-3-PyP(5+), and MnTBAP(3-). All Mn(III) porphyrins (MnPs) have metal-centered reduction potential, E1/2 for Mn(III)P/Mn(II)P redox couple, ranging from -194 to +340 mV versus NHE, log kcat(O2(•-)) from 3.16 to 7.92, and log kred(ONOO(-)) from 5.02 to 7.53. The lipophilicity, expressed as partition between n-octanol and water, log POW, was in the range -1.67 to -7.67. The therapeutic potential of MnPs was assessed via: (i) in vitro ability to prevent spontaneous lipid peroxidation in rat brain homogenate as assessed by malondialdehyde levels; (ii) in vivo O2(•-) specific assay to measure the efficacy in protecting the aerobic growth of SOD-deficient Saccharomyces cerevisiae; and (iii) aqueous solution chemistry to measure the reactivity toward major in vivo endogenous antioxidant, ascorbate. Under the conditions of lipid peroxidation assay, the transport across the cellular membranes, and in turn shape and size of molecule, played no significant role. Those MnPs of E1/2 ∼ +300 mV were the most efficacious, significantly inhibiting lipid peroxidation in 0.5-10 μM range. At up to 200 μM, MnTBAP(3-) (E1/2 = -194 mV vs NHE) failed to inhibit lipid peroxidation, while MnTE-2-PyPhP(5+) with 129 mV more positive E1/2 (-65 mV vs NHE) was fully efficacious at 50 μM. The E1/2 of Mn(III)P/Mn(II)P redox couple is proportional to the log kcat(O2(•-)), i.e., the SOD-like activity of MnPs. It is further proportional to kred(ONOO(-)) and the ability of MnPs to prevent lipid peroxidation. In turn, the inhibition of lipid peroxidation by MnPs is also proportional to their SOD-like activity. In an in vivo S. cerevisiae assay, however, while E1/2 predominates, lipophilicity significantly affects the efficacy of MnPs. MnPs of similar log POW and E1/2, that have linear alkyl or alkoxyalkyl pyridyl substituents, distribute more easily within a cell and in turn provide higher protection to S. cerevisiae in comparison to MnP with bulky cyclic substituents. The bell-shape curve, with MnTE-2-PyP(5+) exhibiting the highest ability to catalyze ascorbate oxidation, has been established and discussed. Our data support the notion that the SOD-like activity of MnPs parallels their therapeutic potential, though species other than O2(•-), such as peroxynitrite, H2O2, lipid reactive species, and cellular reductants, may be involved in their mode(s) of action(s).
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Affiliation(s)
- Artak Tovmasyan
- Departments of Radiation Oncology and Medicine, Duke University Medical Center, Research Drive, 281b MSRB I, Durham, North Carolina 27710, United States
| | - Sebastian Carballal
- Departamento
de Bioquímica and Center for Free Radical and Biomedical
Research, Facultad de Medicina, Universidad
de la República, Montevideo, Uruguay
| | - Robert Ghazaryan
- Department of Organic Chemistry, Faculty
of Pharmacy, Yerevan State Medical University, Yerevan, Armenia
| | - Lida Melikyan
- Department of Organic Chemistry, Faculty
of Pharmacy, Yerevan State Medical University, Yerevan, Armenia
| | - Tin Weitner
- Departments of Radiation Oncology and Medicine, Duke University Medical Center, Research Drive, 281b MSRB I, Durham, North Carolina 27710, United States
| | - Clarissa
G. C. Maia
- Departamento de Quimica, CCEN, Universidade
Federal de Paraiba, Joao Pessoa, PB 58051-900, Brazil
| | - Julio S. Reboucas
- Departamento de Quimica, CCEN, Universidade
Federal de Paraiba, Joao Pessoa, PB 58051-900, Brazil
| | - Rafael Radi
- Departamento
de Bioquímica and Center for Free Radical and Biomedical
Research, Facultad de Medicina, Universidad
de la República, Montevideo, Uruguay
| | - Ivan Spasojevic
- Departments of Radiation Oncology and Medicine, Duke University Medical Center, Research Drive, 281b MSRB I, Durham, North Carolina 27710, United States
| | - Ludmil Benov
- Department of Biochemistry, Faculty of Medicine, Kuwait University, Kuwait City, Kuwait
| | - Ines Batinic-Haberle
- Departments of Radiation Oncology and Medicine, Duke University Medical Center, Research Drive, 281b MSRB I, Durham, North Carolina 27710, United States
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Novel amphiphilic cationic porphyrin and its Ag(II) complex as potential anticancer agents. J Inorg Biochem 2014; 140:94-103. [PMID: 25086237 DOI: 10.1016/j.jinorgbio.2014.06.013] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2013] [Revised: 06/18/2014] [Accepted: 06/18/2014] [Indexed: 11/23/2022]
Abstract
In the present study we have synthesized a novel amphiphilic porphyrin and its Ag(II) complex through modification of water-soluble porphyrinic structure in order to increase its lipophilicity and in turn pharmacological potency. New cationic non-symmetrical meso-substituted porphyrins were characterized by UV-visible, electrospray ionization mass spectrometry (ESI-MS), (1)H NMR techniques, lipophilicity (thin-layer chromatographic retention factor, Rf), and elemental analysis. The key toxicological profile (i.e. cytotoxicity and cell line- (cancer type-) specificity; genotoxicity; cell cycle effects) of amphiphilic Ag porphyrin was studied in human normal and cancer cell lines of various tissue origins and compared with its water-soluble analog. Structural modification of the molecule from water-soluble to amphiphilic resulted in a certain increase in the cytotoxicity and a decrease in cell line-specificity. Importantly, Ag(II) porphyrin showed less toxicity to normal cells and greater toxicity to their cancerous counterparts as compared to cisplatin. The amphiphilic complex was also not genotoxic and demonstrated a slight cytostatic effect via the cell cycle delay due to the prolongation of S-phase. As expected, the performed structural modification affected also the photocytotoxic activity of metal-free amphiphilic porphyrin. The ligand tested on cancer cell line revealed a dramatic (more than 70-fold) amplification of its phototoxic activity as compared to its water-soluble tetracationic metal-free analog. The compound combines low dark cytotoxicity with 5 fold stronger phototoxicity relative to Chlorin e6 and could be considered as a potential photosensitizer for further development in photodynamic therapy.
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Tovmasyan A, Reboucas JS, Benov L. Simple biological systems for assessing the activity of superoxide dismutase mimics. Antioxid Redox Signal 2014; 20:2416-36. [PMID: 23964890 PMCID: PMC4005499 DOI: 10.1089/ars.2013.5576] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
SIGNIFICANCE Half a century of research provided unambiguous proof that superoxide and species derived from it-reactive oxygen species (ROS)-play a central role in many diseases and degenerative processes. This stimulated the search for pharmaceutical agents that are capable of preventing oxidative damage, and methods of assessing their therapeutic potential. RECENT ADVANCES The limitations of superoxide dismutase (SOD) as a therapeutic tool directed attention to small molecules, SOD mimics, that are capable of catalytically scavenging superoxide. Several groups of compounds, based on either metal complexes, including metalloporphyrins, metallocorroles, Mn(II) cyclic polyamines, and Mn(III) salen derivatives, or non-metal based compounds, such as fullerenes, nitrones, and nitroxides, have been developed and studied in vitro and in vivo. Very few entered clinical trials. CRITICAL ISSUES AND FUTURE DIRECTIONS Development of SOD mimics requires in-depth understanding of their mechanisms of biological action. Elucidation of both molecular features, essential for efficient ROS-scavenging in vivo, and factors limiting the potential side effects requires biologically relevant and, at the same time, relatively simple testing systems. This review discuses the advantages and limitations of genetically engineered SOD-deficient unicellular organisms, Escherichia coli and Saccharomyces cerevisiae as tools for investigating the efficacy and mechanisms of biological actions of SOD mimics. These simple systems allow the scrutiny of the minimal requirements for a functional SOD mimic: the association of a high catalytic activity for superoxide dismutation, low toxicity, and an efficient cellular uptake/biodistribution.
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Affiliation(s)
- Artak Tovmasyan
- 1 Department of Radiation Oncology, Duke University Medical Center , Durham, North Carolina
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Batinic-Haberle I, Tovmasyan A, Roberts ERH, Vujaskovic Z, Leong KW, Spasojevic I. SOD therapeutics: latest insights into their structure-activity relationships and impact on the cellular redox-based signaling pathways. Antioxid Redox Signal 2014; 20:2372-415. [PMID: 23875805 PMCID: PMC4005498 DOI: 10.1089/ars.2012.5147] [Citation(s) in RCA: 169] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2013] [Revised: 06/30/2013] [Accepted: 07/22/2013] [Indexed: 01/23/2023]
Abstract
SIGNIFICANCE Superoxide dismutase (SOD) enzymes are indispensable and ubiquitous antioxidant defenses maintaining the steady-state levels of O2·(-); no wonder, thus, that their mimics are remarkably efficacious in essentially any animal model of oxidative stress injuries thus far explored. RECENT ADVANCES Structure-activity relationship (half-wave reduction potential [E1/2] versus log kcat), originally reported for Mn porphyrins (MnPs), is valid for any other class of SOD mimics, as it is dominated by the superoxide reduction and oxidation potential. The biocompatible E1/2 of ∼+300 mV versus normal hydrogen electrode (NHE) allows powerful SOD mimics as mild oxidants and antioxidants (alike O2·(-)) to readily traffic electrons among reactive species and signaling proteins, serving as fine mediators of redox-based signaling pathways. Based on similar thermodynamics, both SOD enzymes and their mimics undergo similar reactions, however, due to vastly different sterics, with different rate constants. CRITICAL ISSUES Although log kcat(O2·(-)) is a good measure of therapeutic potential of SOD mimics, discussions of their in vivo mechanisms of actions remain mostly of speculative character. Most recently, the therapeutic and mechanistic relevance of oxidation of ascorbate and glutathionylation and oxidation of protein thiols by MnP-based SOD mimics and subsequent inactivation of nuclear factor κB has been substantiated in rescuing normal and killing cancer cells. Interaction of MnPs with thiols seems to be, at least in part, involved in up-regulation of endogenous antioxidative defenses, leading to the healing of diseased cells. FUTURE DIRECTIONS Mechanistic explorations of single and combined therapeutic strategies, along with studies of bioavailability and translational aspects, will comprise future work in optimizing redox-active drugs.
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Affiliation(s)
- Ines Batinic-Haberle
- Department of Radiation Oncology, Duke University Medical School, Durham, North Carolina
| | - Artak Tovmasyan
- Department of Radiation Oncology, Duke University Medical School, Durham, North Carolina
| | - Emily R. H. Roberts
- Department of Biomedical Engineering, Duke University, Durham, North Carolina
| | - Zeljko Vujaskovic
- Department of Radiation Oncology, Duke University Medical School, Durham, North Carolina
| | - Kam W. Leong
- Department of Biomedical Engineering, Duke University, Durham, North Carolina
- King Abdulaziz University, Jeddah, Saudi Arabia Kingdom
| | - Ivan Spasojevic
- Department of Medicine, Duke University Medical School, Durham, North Carolina
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Vahidfar N, Jalilian AR, Fazaeli Y, Bahrami-Samani A, Beiki D, Khalaj A. Radiosynthesis and biological evaluation of 166Ho labeled methoxylated porphyrins as possible therapeutic agents. J Radioanal Nucl Chem 2014. [DOI: 10.1007/s10967-014-3113-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Evans MK, Tovmasyan A, Batinic-Haberle I, Devi GR. Mn porphyrin in combination with ascorbate acts as a pro-oxidant and mediates caspase-independent cancer cell death. Free Radic Biol Med 2014; 68:302-14. [PMID: 24334253 PMCID: PMC4404036 DOI: 10.1016/j.freeradbiomed.2013.11.031] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2012] [Revised: 11/01/2013] [Accepted: 11/06/2013] [Indexed: 01/13/2023]
Abstract
Resistance to therapy-mediated apoptosis in inflammatory breast cancer, an aggressive and distinct subtype of breast cancer, was recently attributed to increased superoxide dismutase (SOD) expression, glutathione (GSH) content, and decreased accumulation of reactive species. In this study, we demonstrate the unique ability of two Mn(III) N-substituted pyridylporphyrin (MnP)-based SOD mimics (MnTE-2-PyP(5+) and MnTnBuOE-2-PyP(5+)) to catalyze oxidation of ascorbate, leading to the production of excessive levels of peroxide, and in turn cell death. The accumulation of peroxide, as a consequence of MnP+ascorbate treatment, was fully reversed by the administration of exogenous catalase, showing that hydrogen peroxide is essential for cell death. Cell death as a consequence of the action of MnP+ascorbate corresponded to decreases in GSH levels, prosurvival signaling (p-NF-κB, p-ERK1/2), and in expression of X-linked inhibitor of apoptosis protein, the most potent caspase inhibitor. Although markers of classical apoptosis were observed, including PARP cleavage and annexin V staining, administration of a pan-caspase inhibitor, Q-VD-OPh, did not reverse the observed cytotoxicity. MnP+ascorbate-treated cells showed nuclear translocation of apoptosis-inducing factor, suggesting the possibility of a mechanism of caspase-independent cell death. Pharmacological ascorbate has already shown promise in recently completed phase I clinical trials, in which its oxidation and subsequent peroxide formation was catalyzed by endogenous metalloproteins. The catalysis of ascorbate oxidation by an optimized metal-based catalyst (such as MnP) carries a large therapeutic potential as an anticancer agent by itself or in combination with other modalities such as radio- and chemotherapy.
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Affiliation(s)
- Myron K Evans
- Department of Surgery, Duke University Medical Center, Durham, NC 27710, USA; Department of Pathology, Duke University Medical Center, Durham, NC 27710, USA
| | - Artak Tovmasyan
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710, USA
| | - Ines Batinic-Haberle
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710, USA; Duke Cancer Institute, Duke University Medical Center, Durham, NC 27710, USA.
| | - Gayathri R Devi
- Department of Surgery, Duke University Medical Center, Durham, NC 27710, USA; Department of Pathology, Duke University Medical Center, Durham, NC 27710, USA; Duke Cancer Institute, Duke University Medical Center, Durham, NC 27710, USA.
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Gauter-Fleckenstein B, Reboucas JS, Fleckenstein K, Tovmasyan A, Owzar K, Jiang C, Batinic-Haberle I, Vujaskovic Z. Robust rat pulmonary radioprotection by a lipophilic Mn N-alkylpyridylporphyrin, MnTnHex-2-PyP(5+). Redox Biol 2014; 2:400-10. [PMID: 24624330 PMCID: PMC3949096 DOI: 10.1016/j.redox.2013.12.017] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Revised: 12/19/2013] [Accepted: 12/20/2013] [Indexed: 12/21/2022] Open
Abstract
With the goal to enhance the distribution of cationic Mn porphyrins within mitochondria, the lipophilic Mn(III)meso-tetrakis(N-n-hexylpyridinium-2-yl)porphyrin, MnTnHex-2-PyP(5+) has been synthesized and tested in several different model of diseases, where it shows remarkable efficacy at as low as 50 µg/kg single or multiple doses. Yet, in a rat lung radioprotection study, at higher 0.6-1 mg/kg doses, due to its high accumulation and micellar character, it became toxic. To avoid the toxicity, herein the pulmonary radioprotection of MnTnHex-2-PyP(5+) was assessed at 50 µg/kg. Fischer rats were irradiated to their right hemithorax (28 Gy) and treated with 0.05 mg/kg/day of MnTnHex-2-PyP(5+) for 2 weeks by subcutaneously-implanted osmotic pumps, starting at 2 h post-radiation. The body weights and breathing frequencies were followed for 10 weeks post-radiation, when the histopathology and immunohistochemistry were assessed. Impact of MnTnHex-2-PyP(5+) on macrophage recruitment (ED-1), DNA oxidative damage (8-OHdG), TGF-β1, VEGF(A) and HIF-1α were measured. MnTnHex-2-PyP(5+) significantly decreased radiation-induced lung histopathological (H&E staining) and functional damage (breathing frequencies), suppressed oxidative stress directly (8-OHdG), or indirectly, affecting TGF-β1, VEGF (A) and HIF-1α pathways. The magnitude of the therapeutic effects is similar to the effects demonstrated under same experimental conditions with 120-fold higher dose of ~5000-fold less lipophilic Mn(III)meso-tetrakis(N-ethylpyridinium-2-yl)porphyrin, MnTE-2-PyP(5+).
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Key Words
- 8-OHdG, 8-hydroxy-2'-deoxyguanosine
- AKT, protein kinase B (PKB), a serine/threonine-specific protein kinase
- ALS, amyotrophic laterial sclerosis
- AP-1, activator protein-1
- AT, ataxia telangiectasia
- BBB, blood brain barrier
- Breathing frequencies
- CNS, central nervous system
- CO3−, carbonate radical
- ClO−, hypochlorite
- ETC, mitochondrial electron transport chain
- Fischer rats
- GMP, good manufacturing practice
- GS−, monodeprotonated glutathione
- HIF-1α, hypoxia inducible factor-1
- HO2−, monodeprotonated hydrogen peroxide
- Histopathology
- I/R, ischemia reperfusion
- Immunohistochemistry
- Lung injury
- MCAO, middle cerebral artery occlusion
- Manganese porphyrins
- MnP, Mn porphyrin
- MnTDE-2-ImP5+, Mn(III) tetrakis[N,N'-diethylimidazolium-2-yl)porphyrin, AEOL10150
- MnTE-2-PyP5+
- MnTE-2-PyP5+, Mn(III) meso-tetrakis(N-ethylpyridinium-2-yl)porphyrin (AEOL10113)
- MnTnBuOE-2-PyP5+, Mn(III) meso-tetrakis(N-(n-butoxyethyl)pyridinium-2-yl)porphyrin
- MnTnHex-2-PyP5+
- MnTnHex-2-PyP5+, Mn(III) meso-tetrakis(N-(n-hexyl)pyridinium-2-yl)porphyrin (AEOL10113)
- NF-κB, nuclear factor κB
- NHE, normal hydrogen electrode
- NO, nitric oxide
- NOX4, NADPH oxidase, isoform 4 E1/2, Half-wave metal-centered reduction potential
- Nrf-2, nuclear factor-erythroid-derived 2-like 2
- O2−, superoxide
- ONOO−, peroxynitrite
- PI3K, phosphatidylinositide 3-kinase
- PTEN, phosphoinositide 3-phosphatase
- Radioprotection
- Redox-modulators
- SAH, subarachnoid hemorrhage
- SOD, superoxide dismutase
- SP-1, specificity protein-1
- TF, transcription factor
- TGF-β1, one of the 3 members of the TGF-β transforming growth factor-β family
- VEGF, vascular endothelial growth factor
- mTOR, mammalian target of rapamycin (mTOR), a serine/threonine protein kinase
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Affiliation(s)
- Benjamin Gauter-Fleckenstein
- Department of Radiation Oncology, Duke University School of Medicine, Durham, NC 27710, USA ; Department of Radiation Oncology, Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Julio S Reboucas
- Department of Radiation Oncology, Duke University School of Medicine, Durham, NC 27710, USA
| | - Katharina Fleckenstein
- Department of Radiation Oncology, Duke University School of Medicine, Durham, NC 27710, USA ; Department of Radiation Oncology, Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Artak Tovmasyan
- Department of Radiation Oncology, Duke University School of Medicine, Durham, NC 27710, USA
| | - Kouros Owzar
- Department of Biostatistics and Bioinformatics, Duke University Medical Center, Durham, USA ; Biostatistics and Computational Biology Core, RadCCORE, Duke University Medical Center, Durham, USA
| | - Chen Jiang
- Biostatistics and Computational Biology Core, RadCCORE, Duke University Medical Center, Durham, USA
| | - Ines Batinic-Haberle
- Department of Radiation Oncology, Duke University School of Medicine, Durham, NC 27710, USA
| | - Zeljko Vujaskovic
- Department of Radiation Oncology, Duke University School of Medicine, Durham, NC 27710, USA ; Division of Translational Radiation Sciences, Department of Radiation Oncology, University of Maryland, 655W Baltimore Street, Bressler Research Building, 8-025, Baltimore, MD 21201, USA
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Ali DK, Oriowo M, Tovmasyan A, Batinic-Haberle I, Benov L. Late administration of Mn porphyrin-based SOD mimic enhances diabetic complications. Redox Biol 2013; 1:457-66. [PMID: 24191241 PMCID: PMC3815015 DOI: 10.1016/j.redox.2013.09.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Revised: 09/11/2013] [Accepted: 09/12/2013] [Indexed: 01/12/2023] Open
Abstract
Mn(III) N-alkylpyridylporphyrins (MnPs) have demonstrated protection in various conditions where increased production of reactive oxygen/reactive nitrogen species (ROS/RNS), is a key pathological factors. MnPs can produce both pro-oxidative and antioxidative effects depending upon the cellular redox environment that they encounter. Previously we reported (Free Radic. Res. 39: 81–8, 2005) that when the treatment started at the onset of diabetes, Mn(III) meso-tetrakis(N-methylpyridinium-2-yl)porphyrin, MnTM-2-PyP5+ suppressed diabetes-induced oxidative stress. Diabetes, however, is rarely diagnosed at its onset. The aim of this study was to investigate if MnTM-2-PyP5+ can suppress oxidative damage and prevent diabetic complications when administered more than a week after the onset of diabetes. Diabetes was induced by streptozotocin. The MnP-based treatment started 8 days after the onset of diabetes and continued for 2 months. The effect of the treatment on activities of glutathione peroxidase, superoxide dismutase, catalase, glutathione reductase, glucose-6-phosphate dehydrogenase, glyceraldehyde-3-phosphate dehydrogenase, and glyoxalases I and II as well as malondialdehyde and GSH/GSSG ratio were determined in kidneys. Kidney function was assessed by measuring lysozyme and total protein in urine and blood urea nitrogen. Vascular damage was evaluated by assessing vascular reactivity. Our data showed that delayed administration of MnTM-2-PyP5+ did not protect against oxidative damage and did not prevent diabetic complications. Moreover, MnTM-2-PyP5+ contributed to the kidney damage, which seems to be a consequence of its pro-oxidative action. Such outcome can be explained by advanced oxidative damage which already existed at the moment the therapy with MnP started. The data support the concept that the overall biological effect of a redox-active MnP is determined by (i) the relative concentrations of oxidants and reductants, i.e. the cellular redox environment and (ii) MnP biodistribution. Mn porphyrins (MnP) are among the most potent SOD mimics. MnP suppressed diabetes-induced oxidative stress if applied at the onset of diabetes. Delayed administration of MnP augmented oxidative stress and diabetic complications. The overall in vivo effect of MnP depends on its redox environment.
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Affiliation(s)
- Dana K. Ali
- Department of Biochemistry, Faculty of Medicine, Kuwait University, P.O. Box 24923, Safat 13110, Kuwait
| | - Mabayoje Oriowo
- Department of Pharmacology, Faculty of Medicine, Kuwait University, P.O. Box 24923, Safat 13110, Kuwait
| | - Artak Tovmasyan
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710, USA
| | - Ines Batinic-Haberle
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710, USA
- Correspondence to: Department of Radiation Oncology, Duke University Medical Center, Research Drive, 281b/285, MSRB I, Box 3455, Durham, NC 27710, USA. Tel.: +1 919 684 2101; fax: +1 919 684 8718.
| | - Ludmil Benov
- Department of Biochemistry, Faculty of Medicine, Kuwait University, P.O. Box 24923, Safat 13110, Kuwait
- Corresponding author. Tel.: +965 2531 9489; fax: +965 2533 8908.
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Tovmasyan A, Weitner T, Sheng H, Lu M, Rajic Z, Warner DS, Spasojevic I, Reboucas JS, Benov L, Batinic-Haberle I. Differential coordination demands in Fe versus Mn water-soluble cationic metalloporphyrins translate into remarkably different aqueous redox chemistry and biology. Inorg Chem 2013; 52:5677-91. [PMID: 23646875 DOI: 10.1021/ic3012519] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The different biological behavior of cationic Fe and Mn pyridylporphyrins in Escherichia coli and mouse studies prompted us to revisit and compare their chemistry. For that purpose, the series of ortho and meta isomers of Fe(III) meso-tetrakis-N-alkylpyridylporphyrins, alkyl being methyl to n-octyl, were synthesized and characterized by elemental analysis, UV/vis spectroscopy, mass spectrometry, lipophilicity, protonation equilibria of axial waters, metal-centered reduction potential, E(1/2) for M(III)P/M(II)P redox couple (M = Fe, Mn, P = porphyrin), kcat for the catalysis of O2(•-) dismutation, stability toward peroxide-driven porphyrin oxidative degradation (produced in the catalysis of ascorbate oxidation by MP), ability to affect growth of SOD-deficient E. coli, and toxicity to mice. Electron-deficiency of the metal site is modulated by the porphyrin ligand, which renders Fe(III) porphyrins ≥5 orders of magnitude more acidic than the analogous Mn(III) porphyrins, as revealed by the pKa1 of axially coordinated waters. The 5 log units difference in the acidity between the Mn and Fe sites in porphyrin translates into the predominance of tetracationic (OH)(H2O)FeP complexes relative to pentacationic (H2O)2MnP species at pH ∼7.8. This is additionally evidenced in large differences in the E(1/2) values of M(III)P/M(II)P redox couples. The presence of hydroxo ligand labilizes trans-axial water which results in higher reactivity of Fe relative to Mn center. The differences in the catalysis of O2(•-) dismutation (log kcat) between Fe and Mn porphyrins is modest, 2.5-5-fold, due to predominantly outer-sphere, with partial inner-sphere character of two reaction steps. However, the rate constant for the inner-sphere H2O2-based porphyrin oxidative degradation is 18-fold larger for (OH)(H2O)FeP than for (H2O)2MnP. The in vivo consequences of the differences between the Fe and Mn porphyrins were best demonstrated in SOD-deficient E. coli growth. On the basis of fairly similar log kcat(O2(•-)) values, a very similar effect on the growth of SOD-deficient E. coli was anticipated by both metalloporphyrins. Yet, while (H2O)2MnTE-2-PyP(5+) was fully efficacious at ≥20 μM, the Fe analogue (OH)(H2O)FeTE-2-PyP(4+) supported SOD-deficient E. coli growth at as much as 200-fold lower doses in the range of 0.1-1 μM. Moreover the pattern of SOD-deficient E. coli growth was different with Mn and Fe porphyrins. Such results suggested a different mode of action of these metalloporphyrins. Further exploration demonstrated that (1) 0.1 μM (OH)(H2O)FeTE-2-PyP(4+) provided similar growth stimulation as the 0.1 μM Fe salt, while the 20 μM Mn salt provides no protection to E. coli; and (2) 1 μM Fe porphyrin is fully degraded by 12 h in E. coli cytosol and growth medium, while Mn porphyrin is not. Stimulation of the aerobic growth of SOD-deficient E. coli by the Fe porphyrin is therefore due to iron acquisition. Our data suggest that in vivo, redox-driven degradation of Fe porphyrins resulting in Fe release plays a major role in their biological action. Possibly, iron reconstitutes enzymes bearing [4Fe-4S] clusters as active sites. Under the same experimental conditions, (OH)(H2O)FePs do not cause mouse arterial hypotension, whereas (H2O)2MnPs do, which greatly limits the application of Mn porphyrins in vivo.
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Affiliation(s)
- Artak Tovmasyan
- Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina 27710, United States
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Tovmasyan A, Sheng H, Weitner T, Arulpragasam A, Lu M, Warner DS, Vujaskovic Z, Spasojevic I, Batinic-Haberle I. Design, mechanism of action, bioavailability and therapeutic effects of mn porphyrin-based redox modulators. Med Princ Pract 2012; 22:103-30. [PMID: 23075911 PMCID: PMC3640855 DOI: 10.1159/000341715] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2012] [Accepted: 07/01/2012] [Indexed: 12/18/2022] Open
Abstract
Based on aqueous redox chemistry and simple in vivo models of oxidative stress, Escherichia coli and Saccharomyces cerevisiae, the cationic Mn(III) N-substituted pyridylporphyrins (MnPs) have been identified as the most potent cellular redox modulators within the porphyrin class of drugs; their efficacy in animal models of diseases that have oxidative stress in common is based on their high ability to catalytically remove superoxide, peroxynitrite, carbonate anion radical, hypochlorite, nitric oxide, lipid peroxyl and alkoxyl radicals, thus suppressing the primary oxidative event. While doing so MnPs could couple with cellular reductants and redox-active proteins. Reactive species are widely accepted as regulators of cellular transcriptional activity: minute, nanomolar levels are essential for normal cell function, while submicromolar or micromolar levels impose oxidative stress, which is evidenced in increased inflammatory and immune responses. By removing reactive species, MnPs affect redox-based cellular transcriptional activity and consequently secondary oxidative stress, and in turn inflammatory processes. The equal ability to reduce and oxidize superoxide during the dismutation process and recently accumulated results suggest that pro-oxidative actions of MnPs may also contribute to their therapeutic effects. All our data identify the superoxide dismutase-like activity, estimated by log k(cat)O2-*), as a good measure for the therapeutic efficacy of MnPs. Their accumulation in mitochondria and their ability to cross the blood-brain barrier contribute to their remarkable efficacy. We summarize herein the therapeutic effects of MnPs in cancer, central nervous system injuries, diabetes, their radioprotective action and potential for imaging. Few of the most potent modulators of cellular redox-based pathways, MnTE2-PyP5+, MnTDE-2-ImP5+, MnTnHex-2-PyP5+ and MnTnBuOE-2-PyP5+, are under preclinical and clinical development.
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Affiliation(s)
- Artak Tovmasyan
- Department of Radiation Oncology, Duke University Medical
Center, Durham, N.C., USA
| | - Huaxin Sheng
- Department of Anesthesiology, Duke University Medical Center,
Durham, N.C., USA
- Department of Multidisciplinary Neuroprotection Laboratories,
Duke University Medical Center, Durham, N.C., USA
| | - Tin Weitner
- Department of Radiation Oncology, Duke University Medical
Center, Durham, N.C., USA
| | - Amanda Arulpragasam
- Department of Duke University Neuroscience Undergraduate
Program, Duke University Medical Center, Durham, N.C., USA
| | - Miaomiao Lu
- Department of Anesthesiology, Duke University Medical Center,
Durham, N.C., USA
- Department of Multidisciplinary Neuroprotection Laboratories,
Duke University Medical Center, Durham, N.C., USA
- Department of Department of Anesthesiology, Second Affiliated
Hospital, Zhengzhou University, Zhengzhou, China
| | - David S. Warner
- Department of Anesthesiology, Duke University Medical Center,
Durham, N.C., USA
- Department of Multidisciplinary Neuroprotection Laboratories,
Duke University Medical Center, Durham, N.C., USA
| | - Zeljko Vujaskovic
- Department of Radiation Oncology, Duke University Medical
Center, Durham, N.C., USA
| | - Ivan Spasojevic
- Department of Medicine, Duke University Medical Center, Durham,
N.C., USA
| | - Ines Batinic-Haberle
- Department of Radiation Oncology, Duke University Medical
Center, Durham, N.C., USA
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Rajic Z, Tovmasyan A, Spasojevic I, Sheng H, Lu M, Li AM, Gralla EB, Warner DS, Benov L, Batinic-Haberle I. A new SOD mimic, Mn(III) ortho N-butoxyethylpyridylporphyrin, combines superb potency and lipophilicity with low toxicity. Free Radic Biol Med 2012; 52:1828-34. [PMID: 22336516 PMCID: PMC3353805 DOI: 10.1016/j.freeradbiomed.2012.02.006] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2011] [Revised: 01/17/2012] [Accepted: 02/03/2012] [Indexed: 10/28/2022]
Abstract
The Mn porphyrins of k(cat)(O(2)(.-)) as high as that of a superoxide dismutase enzyme and of optimized lipophilicity have already been synthesized. Their exceptional in vivo potency is at least in part due to their ability to mimic the site and location of mitochondrial superoxide dismutase, MnSOD. MnTnHex-2-PyP(5+) is the most studied among lipophilic Mn porphyrins. It is of remarkable efficacy in animal models of oxidative stress injuries and particularly in central nervous system diseases. However, when used at high single and multiple doses it becomes toxic. The toxicity of MnTnHex-2-PyP(5+) has been in part attributed to its micellar properties, i.e., the presence of polar cationic nitrogens and hydrophobic alkyl chains. The replacement of a CH(2) group by an oxygen atom in each of the four alkyl chains was meant to disrupt the porphyrin micellar character. When such modification occurs at the end of long alkyl chains, the oxygens become heavily solvated, which leads to a significant drop in the lipophilicity of porphyrin. However, when the oxygen atoms are buried deeper within the long heptyl chains, their excessive solvation is precluded and the lipophilicity preserved. The presence of oxygens and the high lipophilicity bestow the exceptional chemical and physical properties to Mn(III) meso-tetrakis(N-n-butoxyethylpyridinium-2-yl)porphyrin, MnTnBuOE-2-PyP(5+). The high SOD-like activity is preserved and even enhanced: log k(cat)(O(2)(.-))=7.83 vs 7.48 and 7.65 for MnTnHex-2-PyP(5+) and MnTnHep-2-PyP(5+), respectively. MnTnBuOE-2-PyP(5+) was tested in an O(2)(.-) -specific in vivo assay, aerobic growth of SOD-deficient yeast, Saccharomyces cerevisiae, where it was fully protective in the range of 5-30 μM. MnTnHep-2-PyP(5+) was already toxic at 5 μM, and MnTnHex-2-PyP(5+) became toxic at 30 μM. In a mouse toxicity study, MnTnBuOE-2-PyP(5+) was several-fold less toxic than either MnTnHex-2-PyP(5+) or MnTnHep-2-PyP(5+).
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Affiliation(s)
- Zrinka Rajic
- Department of Radiation Oncology, Duke University Medical Center, NC 27710, USA
| | - Artak Tovmasyan
- Department of Radiation Oncology, Duke University Medical Center, NC 27710, USA
| | - Ivan Spasojevic
- Department of Medicine, Duke University Medical Center, NC 27710, USA
| | - Huaxin Sheng
- Department of Anesthesiology, Duke University Medical Center, NC 27710, USA
| | - Miaomiao Lu
- Department of Anesthesiology, Duke University Medical Center, NC 27710, USA
- Department of Anesthesiology, Second Affiliated Hospital, Zhengzhou University, Henan, China
| | - Alice M. Li
- Department of Chemistry and Biochemistry, UCLA, Los Angeles, CA 90095-1569, USA
| | - Edith B. Gralla
- Department of Chemistry and Biochemistry, UCLA, Los Angeles, CA 90095-1569, USA
| | - David S. Warner
- Department of Anesthesiology, Duke University Medical Center, NC 27710, USA
| | - Ludmil Benov
- Department of Biochemistry, Faculty of Medicine, Kuwait University, 13110 Safat, Kuwait
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Miriyala S, Spasojevic I, Tovmasyan A, Salvemini D, Vujaskovic Z, St. Clair D, Batinic-Haberle I. Manganese superoxide dismutase, MnSOD and its mimics. BIOCHIMICA ET BIOPHYSICA ACTA 2012; 1822:794-814. [PMID: 22198225 PMCID: PMC3304004 DOI: 10.1016/j.bbadis.2011.12.002] [Citation(s) in RCA: 286] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2011] [Revised: 12/02/2011] [Accepted: 12/02/2011] [Indexed: 12/20/2022]
Abstract
Increased understanding of the role of mitochondria under physiological and pathological conditions parallels increased exploration of synthetic and natural compounds able to mimic MnSOD - endogenous mitochondrial antioxidant defense essential for the existence of virtually all aerobic organisms from bacteria to humans. This review describes most successful mitochondrially-targeted redox-active compounds, Mn porphyrins and MitoQ(10) in detail, and briefly addresses several other compounds that are either catalysts of O(2)(-) dismutation, or its non-catalytic scavengers, and that reportedly attenuate mitochondrial dysfunction. While not a true catalyst (SOD mimic) of O(2)(-) dismutation, MitoQ(10) oxidizes O(2)(-) to O(2) with a high rate constant. In vivo it is readily reduced to quinol, MitoQH(2), which in turn reduces ONOO(-) to NO(2), producing semiquinone radical that subsequently dismutes to MitoQ(10) and MitoQH(2), completing the "catalytic" cycle. In MitoQ(10), the redox-active unit was coupled via 10-carbon atom alkyl chain to monocationic triphenylphosphonium ion in order to reach the mitochondria. Mn porphyrin-based SOD mimics, however, were designed so that their multiple cationic charge and alkyl chains determine both their remarkable SOD potency and carry them into the mitochondria. Several animal efficacy studies such as skin carcinogenesis and UVB-mediated mtDNA damage, and subcellular distribution studies of Saccharomyces cerevisiae and mouse heart provided unambiguous evidence that Mn porphyrins mimic the site and action of MnSOD, which in turn contributes to their efficacy in numerous in vitro and in vivo models of oxidative stress. Within a class of Mn porphyrins, lipophilic analogs are particularly effective for treating central nervous system injuries where mitochondria play key role. This article is part of a Special Issue entitled: Antioxidants and Antioxidant Treatment in Disease.
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Affiliation(s)
- Sumitra Miriyala
- Graduate Center for Toxicology, University of Kentucky, Lexington, KY, 40536
| | - Ivan Spasojevic
- Department of Medicine, Duke University Medical Center, Durham, NC 27710
| | - Artak Tovmasyan
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710
| | - Daniela Salvemini
- Department of Pharmacological and Physiological Science, Saint Louis University School of Medicine, 1402 South Grand Blvd, St. Louis, MO 63104
| | - Zeljko Vujaskovic
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710
| | - Daret St. Clair
- Graduate Center for Toxicology, University of Kentucky, Lexington, KY, 40536
| | - Ines Batinic-Haberle
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710
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Ye X, Fels D, Tovmasyan A, Aird KM, Dedeugd C, Allensworth JL, Kos I, Park W, Spasojevic I, Devi GR, Dewhirst MW, Leong KW, Batinic-Haberle I. Cytotoxic effects of Mn(III) N-alkylpyridylporphyrins in the presence of cellular reductant, ascorbate. Free Radic Res 2011; 45:1289-306. [PMID: 21859376 DOI: 10.3109/10715762.2011.616199] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Due to the ability to easily accept and donate electrons Mn(III)N-alkylpyridylporphyrins (MnPs) can dismute O(2)(·-), reduce peroxynitrite, but also generate reactive species and behave as pro-oxidants if conditions favour such action. Herein two ortho isomers, MnTE-2-PyP(5+), MnTnHex-2-PyP(5+), and a meta isomer MnTnHex-3-PyP(5+), which differ greatly with regard to their metal-centered reduction potential, E(1/2) (Mn(III)P/Mn(II)P) and lipophilicity, were explored. Employing Mn(III)P/Mn(II)P redox system for coupling with ascorbate, these MnPs catalyze ascorbate oxidation and thus peroxide production. Consequently, cancer oxidative burden may be enhanced, which in turn would suppress its growth. Cytotoxic effects on Caco-2, Hela, 4T1, HCT116 and SUM149 were studied. When combined with ascorbate, MnPs killed cancer cells via peroxide produced outside of the cell. MnTE-2-PyP(5+) was the most efficacious catalyst for peroxide production, while MnTnHex-3-PyP(5+) is most prone to oxidative degradation with H(2) , and thus the least efficacious. A 4T1 breast cancer mouse study of limited scope and success was conducted. The tumour oxidative stress was enhanced and its microvessel density reduced when mice were treated either with ascorbate or MnP/ascorbate; the trend towards tumour growth suppression was detected.
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Affiliation(s)
- Xiaodong Ye
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
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26
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Batinic-Haberle I, Rajic Z, Tovmasyan A, Ye X, Leong KW, Dewhirst MW, Vujaskovic Z, Benov L, Spasojevic I. Diverse functions of cationic Mn(III) N-substituted pyridylporphyrins, recognized as SOD mimics. Free Radic Biol Med 2011; 51:1035-53. [PMID: 21616142 PMCID: PMC3178885 DOI: 10.1016/j.freeradbiomed.2011.04.046] [Citation(s) in RCA: 111] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2010] [Revised: 03/30/2011] [Accepted: 04/29/2011] [Indexed: 10/18/2022]
Abstract
Oxidative stress, a redox imbalance between the endogenous reactive species and antioxidant systems, is common to numerous pathological conditions such as cancer, central nervous system injuries, radiation injury, diabetes etc. Therefore, compounds able to reduce oxidative stress have been actively sought for over 3 decades. Superoxide is the major species involved in oxidative stress either in its own right or through its progeny, such as ONOO⁻, H₂O₂, •OH, CO₃•⁻, and •NO₂. Hence, the very first compounds developed in the late 1970-ies were the superoxide dismutase (SOD) mimics. Thus far the most potent mimics have been the cationic meso Mn(III) N-substituted pyridylporphyrins and N,N'-disubstituted imidazolylporphyrins (MnPs), some of them with k(cat)(O₂·⁻) similar to the k(cat) of SOD enzymes. Most frequently studied are ortho isomers MnTE-2-PyP⁵⁺, MnTnHex-2-PyP⁵⁺, and MnTDE-2-ImP⁵⁺. The ability to disproportionate O₂·⁻ parallels their ability to remove the other major oxidizing species, peroxynitrite, ONOO⁻. The same structural feature that gives rise to the high k(cat)(O₂·⁻) and k(red)(ONOO⁻), allows MnPs to strongly impact the activation of the redox-sensitive transcription factors, HIF-1α, NF-κB, AP-1, and SP-1, and therefore modify the excessive inflammatory and immune responses. Coupling with cellular reductants and other redox-active endogenous proteins seems to be involved in the actions of Mn porphyrins. While hydrophilic analogues, such as MnTE-2-PyP⁵⁺ and MnTDE-2-ImP⁵⁺ are potent in numerous animal models of diseases, the lipophilic analogues, such as MnTnHex-2-PyP⁵⁺, were developed to cross blood brain barrier and target central nervous system and critical cellular compartments, mitochondria. The modification of its structure, aimed to preserve the SOD-like potency and lipophilicity, and diminish the toxicity, has presently been pursued. The pulmonary radioprotection by MnTnHex-2-PyP⁵⁺ was the first efficacy study performed successfully with non-human primates. The Phase I toxicity clinical trials were done on amyotrophic lateral sclerosis patients with N,N'-diethylimidazolium analogue, MnTDE-2-ImP⁵⁺ (AEOL10150). Its aggressive development as a wide spectrum radioprotector by Aeolus Pharmaceuticals has been supported by USA Federal government. The latest generation of compounds, bearing oxygens in pyridyl substituents is presently under aggressive development for cancer and CNS injuries at Duke University and is supported by Duke Translational Research Institute, The Wallace H. Coulter Translational Partners Grant Program, Preston Robert Tisch Brain Tumor Center at Duke, and National Institute of Allergy and Infectious Diseases. Metal center of cationic MnPs easily accepts and donates electrons as exemplified in the catalysis of O₂·⁻ dismutation. Thus such compounds may be equally good anti- and pro-oxidants; in either case the beneficial therapeutic effects may be observed. Moreover, while the in vivo effects may appear antioxidative, the mechanism of action of MnPs that produced such effects may be pro-oxidative; the most obvious example being the inhibition of NF-κB. The experimental data therefore teach us that we need to distinguish between the mechanism/s of action/s of MnPs and the effects we observe. A number of factors impact the type of action of MnPs leading to favorable therapeutic effects: levels of reactive species and oxygen, levels of endogenous antioxidants (enzymes and low-molecular compounds), levels of MnPs, their site of accumulation, and the mutual encounters of all of those species. The complexity of in vivo redox systems and the complex redox chemistry of MnPs challenge and motivate us to further our understanding of the physiology of the normal and diseased cell with ultimate goal to successfully treat human diseases.
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Affiliation(s)
- Ines Batinic-Haberle
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710, USA
- Corresponding authors: Ines Batinic-Haberle, Ph. D. Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710, Tel: 919-684-2101, Fax: 919-684-8718, . Ivan Spasojevic, Ph. D. Department of Medicine, Duke University Medical Center, Durham, NC 27710, Tel: 919-684-8311, Fax: 919-684-8380,
| | - Zrinka Rajic
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710, USA
| | - Artak Tovmasyan
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710, USA
| | - Xiaodong Ye
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA
| | - Kam W. Leong
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA
| | - Mark W. Dewhirst
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710, USA
| | - Zeljko Vujaskovic
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710, USA
| | - Ludmil Benov
- Department of Biochemistry, Faculty of Medicine, Kuwait School of Medicine, Kuwait
| | - Ivan Spasojevic
- Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA
- Corresponding authors: Ines Batinic-Haberle, Ph. D. Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710, Tel: 919-684-2101, Fax: 919-684-8718, . Ivan Spasojevic, Ph. D. Department of Medicine, Duke University Medical Center, Durham, NC 27710, Tel: 919-684-8311, Fax: 919-684-8380,
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Batinić-Haberle I, Rajić Z, Benov L. A combination of two antioxidants (an SOD mimic and ascorbate) produces a pro-oxidative effect forcing Escherichia coli to adapt via induction of oxyR regulon. Anticancer Agents Med Chem 2011; 11:329-40. [PMID: 21355843 PMCID: PMC3652549 DOI: 10.2174/187152011795677562] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2011] [Accepted: 03/10/2011] [Indexed: 11/22/2022]
Abstract
Cationic Mn(III) N-alkylpyridyl (MnTalkyl-2(or 3)-PyP(5+)) and N, N'-dialkylimidazolylporphyrins (MnTDalkyl-2-ImP(5+)) have been regarded as the most powerful SOD mimics/peroxynitrite scavengers - i. e. antioxidants. The ethyl-, MnTE-2-PyP(5+) (AEOL10113), and hexylpyridyl-, MnTnHex-2-PyP(5+) and diethylimidazolylporphyrin, MnTDE-2-ImP(5+) (AEOL10150) have been mostly studied in vitro and in vivo. Given the in vivo abundance of cellular reductants, MnPs can couple with them in removing superoxide. Thus, they could be readily reduced from Mn(III)P to Mn(II)P with ascorbate and glutathione, and in a subsequent step reduce either O(2)(.-) (while acting as superoxide reductase) or oxygen (while exerting pro-oxidative action). Moreover, MnPs can catalyze ascorbate oxidation and in turn hydrogen peroxide production. The in vivo type of MnP action (anti- or pro-oxidative) will depend upon the cellular levels of reactive species, endogenous antioxidants, availability of oxygen, ratio of O(2)(.-)- to peroxide-removing systems, redox ability of MnPs and their cellular localization/bioavailibility. To exemplify the switch from an anti- to pro-oxidative action we have explored a very simple and straightforward system - the superoxide-specific aerobic growth of SOD-deficient E. coli. In such a system, cationic MnPs, ortho and meta MnTE-2-(or 3)-PyP(5+) act as powerful SOD mimics. Yet, in the presence of exogenous ascorbate, the SOD mimics catalyze the H(2)O(2) production, causing oxidative damage to both wild and SOD-deficient strains and inhibiting their growth. Catalase added to the medium reversed the effect indicating that H(2)O(2) is a major damaging/signaling species involved in cell growth suppression. The experiments with oxyR- and soxRS-deficient E. coli were conducted to show that E. coli responds to increased oxidative stress exerted by MnP/ascorbate system by induction of oxyR regulon and thus upregulation of antioxidative defenses such as catalases and peroxidases. As anticipated, when catalase was added into medium to remove H(2)O(2), E. coli did not respond with upregulation of its own antioxidant systems.
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Affiliation(s)
- Ines Batinić-Haberle
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710, USA
| | - Zrinka Rajić
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710, USA
| | - Ludmil Benov
- Department of Biochemistry, Faculty of Medicine, Kuwait School of Medicine, Kuwait
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28
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Keir ST, Dewhirst MW, Kirkpatrick JP, Bigner DD, Batinic-Haberle I. Cellular redox modulator, ortho Mn(III) meso-tetrakis(N-n-hexylpyridinium-2-yl)porphyrin, MnTnHex-2-PyP(5+) in the treatment of brain tumors. Anticancer Agents Med Chem 2011; 11:202-12. [PMID: 21291403 PMCID: PMC3357315 DOI: 10.2174/187152011795255957] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2010] [Accepted: 02/04/2011] [Indexed: 01/11/2023]
Abstract
Despite intensive efforts to improve multimodal treatment of brain tumor, survival remains limited. Current therapy consists of a combination of surgery, irradiation and chemotherapy with predisposition to long-term complications. Identifying novel targeted therapies is therefore at the forefront of brain tumor research. This study explores the utility of a manganese porphyrin in a brain tumor model. The compound used is ortho isomer, mangnese(III) meso-tetrakis(N-n-hexylpyridinium-2-yl)porphyrin, MnTnHex-2-PyP(5+). It is a powerful SOD mimic and peroxynitrite scavenger and a potent modulator of redox-based cellular transcriptional activity, able to suppress excessive immune and inflammatory responses and in turn proliferative pathways. It is further one of the most lipophilic compound among cationic Mn(III) N-alkylpyridylporphyrins, and thus accumulates predominantly in mitochondria relative to cytosol. In mitochondria, MnTnHex-2-PyP(5+) mimics our key antioxidant system, mitochondrial superoxide dismutase, MnSOD, whose overexpression has been widely shown to suppress tumor growth. Importantly, MnTnHex-2-PyP(5+) crosses blood brain barrier in sufficient amounts to demonstrate efficacy in treating CNS injuries. For those reasons we elected to test its effects in inhibiting brain tumor growth. This study is the first report of the antitumor properties of MnTnHex-2-PyP(5+) as a single agent in adult and pediatric glioblastoma multiforme (D-54 MG, D-245 MG, D-256 MG, D-456 MG) and pediatric medulloblastoma (D-341 MED), and is the first case where a redox-able metal complex has been used in glioma therapy. When given subcutaneously to mice bearing subcutaneous and intracranial xenografts, MnTnHex-2-PyP(5+) caused a significant (P ≤ 0.001) growth delay in D 245 MG, D-256 MG, D-341 MED, and D-456 MG tumors. Growth delay for mice bearing subcutaneous xenografts ranged from 3 days in D-54 MG to 34 days in D-341 MED. With mice bearing intracranial xenografts, MnTnHex-2-PyP(5+) increases median survival by 33% in adult glioblastoma multiforme (D-256 MG; p≤ 0.001) and 173% in pediatric medulloblastoma (D-341 MED, <0.001). The beneficial effects of MnTnHex-2-PyP(5+) are presumably achieved either (1) indirectly via elimination of signaling reactive oxygen and nitrogen species (in particular superoxide and peroxynitrite) which in turn would prevent activation of transcription factors; or (2) directly by coupling with cellular reductants and redox-sensitive signaling proteins. The former action is antioxidative while the latter action is presumably pro-oxidative in nature. Our findings suggest that the use of Mn porphyrin-based SOD mimics, and in particular lipophilic analogues such as MnTnHex-2-PyP(5+), is a promising approach for brain tumor therapy.
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Affiliation(s)
- Stephen T. Keir
- The Preston Robert Tisch Brain Tumor Center at Duke, Duke University, Durham NC, 27710, USA
- Department of Surgery, Duke University, Durham NC, 27710, USA
| | - Mark W. Dewhirst
- Department of Radiation Oncology, Duke University, Durham NC, 27710, USA
| | | | - Darell D. Bigner
- The Preston Robert Tisch Brain Tumor Center at Duke, Duke University, Durham NC, 27710, USA
- Department of Pathology, Duke University, Durham NC, 27710, USA
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