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Chen X, Wang H, Shi J, Chen Z, Wang Y, Gu S, Fu Y, Huang J, Ding J, Yu L. An injectable and active hydrogel induces mutually enhanced mild magnetic hyperthermia and ferroptosis. Biomaterials 2023; 298:122139. [PMID: 37148756 DOI: 10.1016/j.biomaterials.2023.122139] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 03/29/2023] [Accepted: 04/27/2023] [Indexed: 05/08/2023]
Abstract
Magnetic hyperthermia therapy (MHT) is a promising new modality to deal with solid tumors, yet the low magnetic-heat conversion efficacy, magnetic resonance imaging (MRI) artifacts, easy leakage of magnetic nanoparticles, and thermal resistance are the main obstacles to expand its clinical applications. Herein, a synergistic strategy based on a novel injectable magnetic and ferroptotic hydrogel is proposed to overcome these bottlenecks and boost the antitumor efficacy of MHT. The injectable hydrogel (AAGel) exhibiting a sol-gel transition upon heating is made of arachidonic acid (AA)-modified amphiphilic copolymers. Ferrimagnetic Zn0.4Fe2.6O4 nanocubes with high-efficiency hysteresis loss mechanism are synthesized and co-loaded into AAGel with RSL3, a potent ferroptotic inducer. This system maintains the temperature-responsive sol-gel transition, and provides the capacity of multiple MHT and achieves accurate heating after a single injection owing to the firm anchoring and uniform dispersion of nanocubes in the gel matrix. The high magnetic-heat conversion efficacy of nanocubes coupled with the application of echo limiting effect avoids the MRI artifacts during MHT. Besides the function of magnetic heating, Zn0.4Fe2.6O4 nanocubes combined with multiple MHT can sustain supply of redox-active iron to generate reactive oxygen species and lipid peroxides and accelerate the release of RLS3 from AAGel, thus enhancing the antitumor efficacy of ferroptosis. In turn, the reinforced ferroptosis can alleviate the MHT-triggered thermal resistance of tumors by impairment of the protective heat shock protein 70. The synergy strategy achieves the complete elimination of CT-26 tumors in mice without causing local tumor recurrence and other severe side effects.
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Affiliation(s)
- Xiaobin Chen
- State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Shanghai Stomatological Hospital & School of Stomatology, Fudan University, Shanghai, 200438, China
| | - Hancheng Wang
- State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Shanghai Stomatological Hospital & School of Stomatology, Fudan University, Shanghai, 200438, China
| | - Jiayue Shi
- State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Shanghai Stomatological Hospital & School of Stomatology, Fudan University, Shanghai, 200438, China
| | - Zhiyong Chen
- State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Shanghai Stomatological Hospital & School of Stomatology, Fudan University, Shanghai, 200438, China
| | - Yaoben Wang
- State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Shanghai Stomatological Hospital & School of Stomatology, Fudan University, Shanghai, 200438, China
| | - Siyi Gu
- State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Shanghai Stomatological Hospital & School of Stomatology, Fudan University, Shanghai, 200438, China
| | - Ye Fu
- State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Shanghai Stomatological Hospital & School of Stomatology, Fudan University, Shanghai, 200438, China
| | - Jiale Huang
- State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Shanghai Stomatological Hospital & School of Stomatology, Fudan University, Shanghai, 200438, China
| | - Jiandong Ding
- State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Shanghai Stomatological Hospital & School of Stomatology, Fudan University, Shanghai, 200438, China
| | - Lin Yu
- State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Shanghai Stomatological Hospital & School of Stomatology, Fudan University, Shanghai, 200438, China.
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Stewart C, Mamori M, Arman H, Musie GT. Synthesis, Characterization and Spectroscopic Investigation of Novel Tetra‐Iron(III) Complexes and D‐Glucose under Redox Conditions. ChemistrySelect 2021. [DOI: 10.1002/slct.202102315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Christopher Stewart
- Department of Chemistry The University of Texas at San Antonio San Antonio TX 78249 United States
| | - Myles Mamori
- Department of Chemistry The University of Texas at San Antonio San Antonio TX 78249 United States
| | - Hadi Arman
- Department of Chemistry The University of Texas at San Antonio San Antonio TX 78249 United States
| | - Ghezai T. Musie
- Department of Chemistry The University of Texas at San Antonio San Antonio TX 78249 United States
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Subramanian M, Chintalwar GJ, Chattopadhyay S. Iron modulatory property of a polysaccharide from Indian medicinal plant Ocimum sanctum. Free Radic Res 2021; 55:510-519. [PMID: 33327808 DOI: 10.1080/10715762.2020.1866179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Despite being an essential element for normal functioning of cells and organisms, iron, in excess, can induce oxidative stress by generating reactive oxygen species. A water-soluble, non-toxic iron chelator can reduce the iron-induced oxidative stress in the body as well as help in extricating excess iron. Herein, we report an Ocimum sanctum-derived antioxidant polysaccharide (OSP) that inhibits the deleterious effect of iron. Ocimum sanctum is a widely acknowledged medicinal plant contributing toward several biological benefits. Besides showing good hydroxyl radical scavenging activity, OSP could bind to ferric and ferrous ions to prevent their participation in redox reactions as revealed from modified 2-deoxyribose assays, carried out under various conditions. It also acted as an iron modulator to prevent site-specific damage and was effective in protecting mouse fibroblast L929 cells against iron induced death.
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Affiliation(s)
- Mahesh Subramanian
- Bio-Organic Division, Bhabha Atomic Research Centre, Mumbai, India.,Homi Bhabha National Institute, Mumbai, India
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Pless-Petig G, Metzenmacher M, Türk TR, Rauen U. Aggravation of cold-induced injury in Vero-B4 cells by RPMI 1640 medium - identification of the responsible medium components. BMC Biotechnol 2012; 12:73. [PMID: 23046946 PMCID: PMC3534012 DOI: 10.1186/1472-6750-12-73] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Accepted: 10/04/2012] [Indexed: 01/24/2023] Open
Abstract
BACKGROUND In modern biotechnology, there is a need for pausing cell lines by cold storage to adapt large-scale cell cultures to the variable demand for their products. We compared various cell culture media/solutions for cold storage of Vero-B4 kidney cells, a cell line widely used in biotechnology. RESULTS Cold storage in RPMI 1640 medium, a recommended cell culture medium for Vero-B4 cells, surprisingly, strongly enhanced cold-induced cell injury in these cells in comparison to cold storage in Krebs-Henseleit buffer or other cell culture media (DMEM, L-15 and M199). Manufacturer, batch, medium supplements and the most likely components with concentrations outside the range of the other media/solutions (vitamin B12, inositol, biotin, p-aminobenzoic acid) did not cause this aggravation of cold-induced injury in RPMI 1640. However, a modified Krebs-Henseleit buffer with a low calcium concentration (0.42 mM), a high concentration of inorganic phosphate (5.6 mM), and glucose (11.1 mM; i.e. concentrations as in RPMI 1640) evoked a cell injury and loss of metabolic function corresponding to that observed in RPMI 1640. Deferoxamine improved cell survival and preserved metabolic function in modified Krebs-Henseleit buffer as well as in RPMI 1640. Similar Ca2+ and phosphate concentrations did not increase cold-induced cell injury in the kidney cell line LLC-PK1, porcine aortic endothelial cells or rat hepatocytes. However, more extreme conditions (Ca2+ was nominally absent and phosphate concentration raised to 25 mM as in the organ preservation solution University of Wisconsin solution) also increased cold-induced injury in rat hepatocytes and porcine aortic endothelial cells. CONCLUSION These data suggest that the combination of low calcium and high phosphate concentrations in the presence of glucose enhances cold-induced, iron-dependent injury drastically in Vero-B4 cells, and that a tendency for this pathomechanism also exists in other cell types.
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Affiliation(s)
- Gesine Pless-Petig
- Institut für Physiologische Chemie, Universitätsklinikum Essen, Universität Duisburg-Essen, Hufelandstr, 55, 45122, Essen, Germany
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Rescuing hepatocytes from iron-catalyzed oxidative stress using vitamins B1 and B6. Toxicol In Vitro 2011; 25:1114-22. [PMID: 21457772 DOI: 10.1016/j.tiv.2011.03.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2011] [Revised: 03/22/2011] [Accepted: 03/23/2011] [Indexed: 11/22/2022]
Abstract
In the following rescue experiments, iron-mediated hepatocyte oxidative stress cytotoxicity was found to be prevented if vitamin B1 or B6 was added 1h after treatment with iron. The role of iron in catalyzing Fenton-mediated oxidative damage has been implicated in iron overload genetic diseases, carcinogenesis (colon cancer), Alzheimer's disease and complications associated with the metabolic syndrome through the generation of reactive oxygen species (ROS). The objectives of this study were to interpret the cytotoxic mechanisms and intracellular targets of oxidative stress using "accelerated cytotoxicity mechanism screening" techniques (ACMS) and to evaluate the rescue strategies of vitamins B1 and B6. Significant cytoprotection by antioxidants or ROS scavengers indicated that iron-mediated cytotoxicity could be attributed to reactive oxygen species. Of the B6 vitamers, pyridoxal was best at rescuing hepatocytes from iron-catalyzed lipid peroxidation (LPO), protein oxidation, and DNA damage, while pyridoxamine manifested greatest protection against ROS-mediated damage. Thiamin (B1) decreased LPO, mitochondrial and protein damage and DNA oxidation. Together, these results indicate that added B1 and B6 vitamins protect against the multiple targets of iron-catalyzed oxidative damage in hepatocytes. This study provides insight into the search for multi-targeted natural therapies to slow or retard the progression of diseases associated with Fenton-mediated oxidative damage.
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Biological Membranes Are Nanostructures that Require Internal Heat and Imaginary Temperature as New, Unique Physiological Parameters Related to Biological Catalysts. Cell Biochem Biophys 2010; 59:133-46. [DOI: 10.1007/s12013-010-9134-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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The effects of the intraocular dye brilliant blue G (BBG) mixed with varying concentrations of glucose on retinal function in an isolated perfused vertebrate retina. Graefes Arch Clin Exp Ophthalmol 2010; 249:483-9. [DOI: 10.1007/s00417-010-1508-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2010] [Revised: 08/27/2010] [Accepted: 08/29/2010] [Indexed: 10/19/2022] Open
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Dong Q, Yang K, Wong SM, O'Brien PJ. Hepatocyte or serum albumin protein carbonylation by oxidized fructose metabolites: Glyceraldehyde or glycolaldehyde as endogenous toxins? Chem Biol Interact 2010; 188:31-7. [PMID: 20561512 DOI: 10.1016/j.cbi.2010.06.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2010] [Revised: 05/31/2010] [Accepted: 06/09/2010] [Indexed: 01/22/2023]
Abstract
Excessive sugar intake in animal models may cause tissue damage associated with oxidative and carbonyl stress cytotoxicity as well as inflammation. Fructose became a 100-fold more cytotoxic if hepatocytes were exposed to a non-toxic infusion of H(2)O(2) so as to simulate H(2)O(2) released by Kupffer cells or infiltrating immune cells. In order to determine the molecular mechanisms involved, protein carbonylation of fructose and its metabolites were determined using the 2,4-dinitrophenylhydrazine method. In a cell-free system, fructose was found to carbonylate bovine serum albumin (BSA) only if low concentrations of FeII/H(2)O(2) were added. Protein carbonylation by the fructose metabolites glyceraldehyde or glycolaldehyde was also markedly increased by FeII/H(2)O(2). The protein carbonylation may be attributed to glyoxal formation by hydroxyl radicals as the glyoxal trapping agent aminoguanidine or hydroxyl radical scavengers prevented protein carbonylation. Glyoxal was also much more effective than other carbonyls at causing protein carbonylation. When BSA was replaced by isolated rat hepatocytes, fructose metabolite glyceraldehyde in the presence of non-toxic 2 microM FeII:8-hydroxyquinoline (HQ) and a H(2)O(2) generating system (glucose/glucose oxidase) markedly increased cytotoxicity, protein carbonylation and reactive oxygen species (ROS)/H(2)O(2) formation. Furthermore this was prevented by hydroxyl radical scavengers or aminoguanidine, a glyoxal scavenger. CuII: 8-hydroxyquinoline increased H(2)O(2) induced hepatocyte protein carbonylation less but was prevented by aminoguanidine. However, cytotoxicity and protein carbonylation induced by glyceraldehyde/CuII:HQ/H(2)O(2) were not affected by hydroxyl radical scavengers. Although fatty liver induced by an excessive sugar diet in animal models has been proposed as the first hit for non-alcoholic steatohepatitis (NASH) we propose that oxidative stress induced by the oxidation of fructose or fructose metabolites catalysed by Fenton FeII/H(2)O(2) could be a 'second hit'. A perpetual cycle of oxidative stress in hepatocytes could lead to cytotoxicity and contribute to NASH development.
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Affiliation(s)
- Qiang Dong
- College of Veterinary Medicine, Northwest A & F University, Yangling, Shaanxi 712100, China
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Pouponneau P, Savadogo O, Napporn T, Yahia L, Martel S. Corrosion study of iron-cobalt alloys for MRI-based propulsion embedded in untethered microdevices operating in the vascular network. J Biomed Mater Res B Appl Biomater 2010; 93:203-11. [PMID: 20119943 DOI: 10.1002/jbm.b.31575] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Our group have shown in an experiment performed in the carotid artery of a living swine that magnetic gradients generated by a clinical magnetic resonance imaging (MRI) system could propel and navigate untethered medical microdevices and micro-nanorobots in the human vasculature. The main problem with these devices is that the metal necessary for magnetic propulsion may corrode and induce cytotoxic effects. The challenge, then, is to find an alloy with low corrosion yet providing an adequate magnetization level for propulsion in often stringent physiological conditions. Because of their high magnetization, we studied the corrosion behavior of two iron-cobalt alloys, Permendur (49% Fe, 49% Co, 2% V) and Vacoflux 17 (81% Fe, 17% Co, 2% Cr), in physiological solution by potentiodynamic polarization assay, surface analysis, and corrosion electrolyte analysis. Both alloys exhibited low corrosion parameters such as a corrosion potential (E(corr)) of -0.57 V/SCE and E(corr) of -0.42 V/SCE for Vacoflux 17. The surface of Permendur samples was homogenously degraded. Vacoflux 17 surface was impaired by cracks and crevices. Both alloys had a stoichiometric dissolution in the electrolyte, and they released enough cobalt to induce cytotoxic effects. This study concluded that Fe-Co alloys could be used preferably in medical microdevices if they were coated so as not to come in contact with physiological solutions.
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Affiliation(s)
- Pierre Pouponneau
- Nanorobotics Laboratory, Ecole Polytechnique de Montréal (EPM), Montréal, Canada
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10
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May JM, Qu ZC. Chelation of intracellular iron enhances endothelial barrier function: a role for vitamin C? Arch Biochem Biophys 2010; 500:162-8. [PMID: 20510668 DOI: 10.1016/j.abb.2010.05.022] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2010] [Revised: 05/12/2010] [Accepted: 05/21/2010] [Indexed: 10/19/2022]
Abstract
Ascorbic acid improves endothelial barrier function by decreasing the permeability of endothelial cells cultured on semi-porous membrane filters. This decrease was not due to enhanced collagen synthesis and was mimicked by the collagen synthesis inhibitor ethyl-3,4-dihydroxybenzoic acid (EDHB). Since EDHB is known to chelate intracellular free iron, the effects of two membrane-permeant iron chelators were tested on endothelial permeability. Both 2,2'-dipyridyl and desferrioxamine decreased trans-endothelial permeability in a concentration-dependent manner. Increasing intracellular iron with a chelate of 8-hydroxyquinoline and ferric iron prevented effects of both EDHB and intracellular ascorbate. That EDHB and ascorbate did in fact chelate intracellular iron was supported by finding that they both decreased the cellular fluorescence quenching of the iron-sensitive dye Phen green SK. These results show that chelation of intracellular iron decreases endothelial barrier permeability and implicate this mechanism in the ability of EDHB and possibly intracellular ascorbate to tighten the endothelial barrier.
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Affiliation(s)
- James M May
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN 37232-0475, United States.
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Prakash M, Upadhya S. Transitional metal ions induced damage to biomolecules: role of ferryl and perferryl radicals. ASIAN PAC J TROP MED 2010. [DOI: 10.1016/s1995-7645(10)60027-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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12
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Liu XC, Wang P, Yan H. A rabbit model to study biochemical damage to the lens after vitrectomy: effects of N-acetylcysteine. Exp Eye Res 2009; 88:1165-70. [PMID: 19450459 DOI: 10.1016/j.exer.2009.01.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2008] [Revised: 01/03/2009] [Accepted: 01/06/2009] [Indexed: 11/19/2022]
Abstract
The purpose of the present study was to determine whether the biochemical effects of vitrectomy can be studied in rabbits and to assess the possible protective effects of N-acetylcysteine on the lens following vitrectomy. Twenty-four New Zealand rabbits (2.3-2.4 kg) were divided into three groups of eight each. Left eyes underwent vitrectomy surgery. Unoperated right eyes served as controls. Equal numbers of treated eyes were not injected, injected with 20 mM N-acetylcysteine, or 100 mM N-acetylcysteine immediately after vitrectomy. Lens transparency was monitored by slit-lamp biomicroscopy pre- and post-vitrectomy. A series of biochemical measurements were performed on lenses five months after vitrectomy. No significant differences in lens transparency or structure were observed in the three groups of lenses. However, vitrectomy was associated with significantly decreased activity of Na(+)-K(+)-ATPase and catalase. Compared with the group not treated with N-acetylcysteine, catalase activity was increased significantly in the group treated with 20 mM N-acetylcysteine. The level of glutathione and the activities of Na(+)-K(+)-ATPase and glutathione reductase were also higher in the two N-acetylcysteine-treated groups than in the untreated group, although these differences did not reach statistical significance. For all measured parameters, the effect of 20 mM N-acetylcysteine appeared to be better than 100 mM N-acetylcysteine, although these differences were not statistically significant. From these results, we gather that vitrectomy is associated with long-term decreases in enzyme activity in the lens. Injection of N-acetylcysteine into the vitreous cavity protects against some of these changes. Antioxidants like N-acetylcysteine may slow or prevent post-vitrectomy cataracts.
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Pamp K, Kerkweg U, Korth HG, Homann F, Rauen U, Sustmann R, de Groot H, Petrat F. Enzymatic reduction of labile iron by organelles of the rat liver. Superior role of an NADH-dependent activity in the outer mitochondrial membrane. Biochimie 2008; 90:1591-601. [PMID: 18627785 DOI: 10.1016/j.biochi.2008.06.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2008] [Accepted: 06/17/2008] [Indexed: 01/13/2023]
Abstract
The enzymatic system mainly responsible for the reduction of labile iron ions in mammalian cells is still unknown. Using isolated organelles of the rat liver, i.e. mitochondria, microsomes, nuclei and the cytosol, we here demonstrate that Fe(III), added as Fe(III)-ATP complex, is predominantly reduced by an NADH-dependent enzyme system associated with mitochondria (65% of the overall enzymatic Fe(III) reduction capacity within liver cells). Microsomes showed a significantly smaller Fe(III) reduction capacity, whereas the cytosol and nuclei hardly reduced Fe(III). Studying the mitochondrial iron reduction, this NADH-dependent process was not mediated by superoxide, ascorbic acid, or NADH itself, excluding low-molecular-weight reductants. No evidence was found for the involvement of complex I and III of the respiratory chain. Submitochondrial preparations revealed the highest specific activity reducing Fe(III) in the outer membrane fraction. In conclusion, an NADH-dependent mitochondrial enzyme system, most likely the NADH-cytochrome c reductase system, located at the outer membrane, should decisively contribute to the enzymatic reduction of labile iron within liver cells, especially under pathological conditions.
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Affiliation(s)
- K Pamp
- Institut für Physiologische Chemie, Universitätsklinikum, Essen, Germany
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Shetty JK, Prakash M, Ibrahim MS. Relationship between free iron and glycated hemoglobin in uncontrolled type 2 diabetes patients associated with complications. Indian J Clin Biochem 2008; 23:67-70. [PMID: 23105724 PMCID: PMC3453647 DOI: 10.1007/s12291-008-0016-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Free iron in serum has been found in several disease conditions including diabetes. In the present work, we studied the relationship between free iron, fasting blood glucose (FBG) and glycated haemoglobin (HbA(1c)). Study was carried out on 50 type 2 diabetes cases under poor glycemic control associated with complications, 53 type 2 diabetes cases under good glycemic control and 40 healthy controls. We estimated free iron, both ferrous (Fe(+2)) and ferric (Fe(+3)) form, protein thiols, lipid hydroperoxides, FBG, HbA1c and serum ferritin levels in serum. There was a significant increase in free iron in Fe(+3) state (p <0.01), HbA(1c) (p<0.01), serum ferritin (p<0.01), lipid hydroperoxides (p<0.01) and significant decrease in protein thiols (<0.01) in diabetes cases under poor glycemic control compared to diabetes cases under good glycemic control and healthy controls. Free iron correlated positively with HbA(1c) (p<0.01). Poor glycemic control and increase in glycation of haemoglobin is contributing to the increase in free iron pool which is known to increase oxidant generation.
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Affiliation(s)
- Jeevan K. Shetty
- Department of Biochemistry, Kasturba Medical College, Manipal, 576104 Karnataka India
| | - Mungli Prakash
- Department of Biochemistry, Kasturba Medical College, Manipal, 576104 Karnataka India
| | - Mohammad S. Ibrahim
- Department of Biochemistry, Kasturba Medical College, Manipal, 576104 Karnataka India
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Breborowicz A, Polubinska A, Breborowicz M, Simon M, Wanic-Kossowska M, Oreopoulos DG. Peritoneal effects of intravenous iron sucrose administration in rats. Transl Res 2007; 149:304-9. [PMID: 17543848 DOI: 10.1016/j.trsl.2006.11.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2006] [Revised: 11/11/2006] [Accepted: 11/14/2006] [Indexed: 11/29/2022]
Abstract
Intravenous iron supplementation is commonly used in uremic patients treated with peritoneal dialysis. Infusion of iron compounds results in various systemic noxious effects, mainly because of its prooxidant and proinflammatory actions. The authors studied how the intravenous infusion of iron sucrose (IS) affects intraperitoneal homeostasis in rats undergoing acute peritoneal dialysis. Experiments were performed on Wistar rats, which were infused intravenously with IS in a dose 10 mg/kg body weight or with normal saline in the controls. Simultaneously, 4-hour acute peritoneal dialysis was started. At the end of the dialysis, systemic and peritoneal inflammatory reaction and peritoneal permeability were evaluated. Compared with controls, rats exposed to IS showed increased dialysate iron concentration by +70%, P<0.001, and in the differential cell count, more eosinophils (+113%, P<0.05) and fewer macrophages (-16%, P<0.05) existed. In in vitro conditions, macrophages obtained from IS-treated rats released more tumor necrosis factor-alpha (TNF-alpha; +173%, P<0.05) upon stimulation with endotoxin. Additionally increased (+73%, P<0.01) dialysate elastase activity was found in IS-treated animals. Rats infused with IS demonstrated increased peritoneal permeability to total protein (+60%, P<0.001) as compared with control animals. When rats with simultaneous peritonitis received intravenous IS, ex vivo isolated peritoneal leukocytes generated more free radicals (+73%, P<0.05) than did cells harvested from control animals. It has been concluded that intravenous infusion of IS affects the intraperitoneal homeostasis in rats, moving it toward the inflammatory state. These changes may contribute to peritoneal damage.
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Rauen U, Springer A, Weisheit D, Petrat F, Korth HG, de Groot H, Sustmann R. Assessment of Chelatable Mitochondrial Iron by Using Mitochondrion-Selective Fluorescent Iron Indicators with Different Iron-Binding Affinities. Chembiochem 2007; 8:341-52. [PMID: 17219451 DOI: 10.1002/cbic.200600311] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Chelatable cellular iron, and chelatable mitochondrial iron in particular, has yet to be well characterized, so the overall strength with which these "loosely bound" iron ions (presumably mainly Fe(II)) are intracellularly/intramitochondrially bound is unclear. We have previously reported the first selective mitochondrial iron indicator: rhodamine B 4-[(1,10-phenanthrolin-5-yl)aminocarbonyl]benzyl ester (RPA). With this compound as a model, we have now developed two additional mitochondrial iron indicators with very different iron-binding affinities and have applied these to the study of the chelatable iron pool in the mitochondria of isolated rat liver cells. With the new indicator rhodamine B 4-[(2,2'-bipyridin-4-yl)aminocarbonyl]benzyl ester (RDA), with 2,2'-bipyridine as chelating unit (log beta(3)=17.5), essentially the same iron concentration (16.0+/-1.9 microM) was determined as with RPA (log beta(3)=21.1), despite the four orders of magnitude difference in Fe(II)-binding affinity. This not only demonstrates the reliability of the procedure, but also confirms that iron complexation by these indicators does not induce any significant release of iron from the iron-storage proteins on the timescale of the experiment. In contrast, the indicator rhodamine B 4-[bis(pyridin-2-ylmethyl)aminomethyl]benzyl ester (PIRO), with an N,N-bis(pyridin-2-ylmethyl)amine group as chelating component (log beta(2)=12.2), could not compete against the array of endogenous ligands. The intramitochondrial concentrations of the three indicators were determined to be in the range of 100 microM: that is, about three orders of magnitude lower than the total concentration of endogenous compounds that might chelate iron ions. It is therefore estimated that chelatable mitochondrial iron ions are bound by endogenous ligands with apparent stability constants (log K(app)) of between 9 and 14.
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Affiliation(s)
- Ursula Rauen
- Institut für Physiologische Chemie, Universitätsklinikum, Hufelandstrasse 55, 45122 Essen, Germany.
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17
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Schubert D. Glucose metabolism and Alzheimer's disease. Ageing Res Rev 2005; 4:240-57. [PMID: 15950548 DOI: 10.1016/j.arr.2005.02.003] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2005] [Accepted: 02/22/2005] [Indexed: 02/07/2023]
Abstract
The brain is the organ with the highest basal rate of glucose consumption. Most of the energy generated by the oxidation of glucose is used for the work necessary to maintain the ionic balances associated with synaptic transmission. When the nervous system is subjected to the oxidative stress of age-associated disease, there is a redistribution of glucose breakdown to pathways that more efficiently produce molecules involved in antioxidant metabolism. This shift is at least in part mediated by the transcription factor HIF-1. The clinical implications of this change in glucose metabolism are discussed in the context of aging and Alzheimer's disease.
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Affiliation(s)
- David Schubert
- Cellular Neurobiology Laboratory, The Salk Institute for Biological Studies, 10010 N, Torrey Pines Road, La Jolla, CA 92037, USA.
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Hutcheson RM, Engelmann MD, Cheng IF. Voltammetric studies of Zn and Fe complexes of EDTA: Evidence for the push mechanism. Biometals 2005; 18:43-51. [PMID: 15865409 DOI: 10.1007/s10534-004-5769-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The 'push' hypothesis for the antioxidant action of Zn2+ is based on its displacement of iron from a low molecular weight pro-oxidant complex. In this study, the chemical plausibility of that proposed function is investigated by cyclic voltammetry. As a model for a pro-oxidative low molecular weight iron complex the Fe(II/III)/EDTA couple was examined. This complex was selected for its well-defined electrochemical, iron stability constants, and similarity to other low molecular weight chelates in physiological fluids in terms of logical binding sites, i.e. amino, and carboxylate groups. Also investigated were iron complexes of nitrilotriacetic acid and DL-glutamic acid. Results demonstrate that approximately 90% of the cyclic voltammetric peak current for Fe(III)EDTA reduction and the EC' current for the mediated reduction of H2O2 by Fe(II/III)EDTA (Fenton Reaction) are lost when Zn2+ is introduced to a 1:1 molar ratio relative to iron. All experiments were conducted in HEPES buffered solutions at pH 7.4. Iron (II/III) complexes of nitrilotriacetic acid and DL-glutamic acid followed the same trends. Cyclic voltammetric experiments indicate that Zn2+ displaces Fe(III) from EDTA despite the much larger stability constant for the iron complex (10(25.1)) versus zinc (10(16.50)). The hydrolysis aided displacement of Fe(III) from EDTA by Zn2+ is considered by the equilibria modeling program, HySS. With Fe(III) hydrolysis products included, Zn2+ is able to achieve 90% displacement of iron from EDTA, a result consistent with cyclic voltammetric observations.
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Affiliation(s)
- Ryan M Hutcheson
- Department of Chemistry, University of Idaho Moscow, Idaho 83844-2343, USA
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19
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Banerjee D, Jacob J, Kunjamma G, Madhusoodanan UK, Ghosh S. Measurement of urinary hydrogen peroxide by FOX-1 method in conjunction with catalase in diabetes mellitus—a sensitive and specific approach. Clin Chim Acta 2004; 350:233-6. [PMID: 15530483 DOI: 10.1016/j.cccn.2004.07.026] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2004] [Revised: 07/27/2004] [Accepted: 07/30/2004] [Indexed: 11/18/2022]
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Rauen U, Li T, Sustmann R, De Groot H. Protection against iron- and hydrogen peroxide-dependent cell injuries by a novel synthetic iron catalase mimic and its precursor, the iron-free ligand. Free Radic Biol Med 2004; 37:1369-83. [PMID: 15454276 DOI: 10.1016/j.freeradbiomed.2004.07.035] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2004] [Revised: 06/02/2004] [Accepted: 07/29/2004] [Indexed: 12/11/2022]
Abstract
Hydrogen peroxide is involved in many types of cell injury and exerts most of its injurious effects in conjunction with chelatable iron. We previously described a synthetic nonporphyrin iron-containing catalase mimic, TAA-1/Fe. Its ligand TAA-1 was designed for application in biological systems in which it is supposed to fulfill a dual task: it should chelate cellular labile iron and thus form the active catalase mimic, thereby decreasing levels of redox-active iron and enhancing the degradation of hydrogen peroxide. Here, we tested these novel compounds in cellular systems, i.e., in cultured hepatocytes and liver endothelial cells. Both the iron complex, i.e., the complete mimic, and the ligand, i.e., the putative precursor of this mimic, provided protection against endothelial cell injury induced by exogenous hydrogen peroxide. Furthermore, the ligand--but not (or less so) the complex--strongly protected both cell types against iron-dependent hypothermic injury and hepatocytes against iron-induced cell injury and against iron-dependent, histidine-induced injury. Together, these results demonstrate that the putative catalase mimic precursor TAA-1 is able to protect cells against iron- and/or hydrogen peroxide-dependent cell injuries and that--in line with our initial concept--it is likely to exert its protection by both iron chelation and hydrogen peroxide degradation.
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Affiliation(s)
- Ursula Rauen
- Institut für Physiologische Chemie, Universitätsklinikum, Hufelandstrasse 55, D-45122 Essen, Germany.
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21
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Hutcheson R, Engelmann MD, Cheng IF. A hypothesis for the basis of the pro-oxidant nature of calcium ions. Biometals 2004; 17:605-13. [PMID: 15689103 DOI: 10.1007/s10534-004-1225-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
A new hypothesis describing the role of the redox inactive Ca2+ ion in the expression of physiological oxidative damage is described. The hypothesis is based on the optimization of the chelation characteristics of iron complexes for pro-oxidant activity. In a previous investigation it was found that an excess of ligand kinetically hindered the Fenton reaction activity of the FeII/III EDTA complex (Bobier et al. 2003). EDTA, citrate, NTA, and glutamate were selected as models for the coordination sites likely encountered by mobile iron, i.e. proteins. The optimal [EDTA]:[FeIII] ratio for Fenton reaction activity as measured by electrocatalytic voltammetry in a solution was found to be 1:1. An excess of EDTA in the amount of 10:1 [ligand]: [metal] suppresses the Fenton reaction activity to nearly the control. It is expected that the physiological coordination characteristics of mobile Fe would have a very large excess of [ligand]:[metal] and thus not be optimized for the Fenton reaction. Introduction of Ca2+ in to a ratio of 10:10:1 [Ca2+]:[EDTA]:[FeIII] to the system reinvigorated the Fenton reaction activity to nearly the value of the optimal 1:1 [EDTA] :[FeIII] complex. The pH distribution diagrams of Ca2+ in the presence of EDTA and FeII/III indicate that Ca2+ has the ability to uptake excess EDTA without displacing either FeII of FeIII from their respective complexed forms. The similarity in the presence for hard ligand sites albeit with a lower binding constant for Ca2+ accounts for this action.
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Affiliation(s)
- Ryan Hutcheson
- Department of chemistry, University of Idaho, Moscow, ID 83844-2343, USA
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22
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Rauen U, Petrat F, Sustmann R, de Groot H. Iron-induced mitochondrial permeability transition in cultured hepatocytes. J Hepatol 2004; 40:607-15. [PMID: 15030976 DOI: 10.1016/j.jhep.2003.12.021] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2003] [Revised: 12/10/2003] [Accepted: 12/29/2003] [Indexed: 12/04/2022]
Abstract
BACKGROUND/AIMS We previously described that the cold-induced apoptosis of cultured hepatocytes and liver endothelial cells is mediated by an increase in the cellular chelatable iron pool-in the absence of any increase in O(2)(.-)/H(2)O(2) formation. As this is an unusual mechanism, we here set out to assess whether an increase in cellular chelatable iron per se is sufficient to trigger cell injury/apoptosis. METHODS Cultured rat hepatocytes were acutely loaded with iron using the membrane-permeable complex Fe(III)/8-hydroxyquinoline and incubated under otherwise 'physiological' conditions. RESULTS Incubation with Fe(III)/8-hydroxyquinoline (15 microM/30 microM) increased the cellular chelatable iron and induced strong hepatocellular injury with morphological features of apoptosis, but also of necrosis. The iron-induced cell injury was oxygen-dependent, and although it was not inhibitable by extracellular catalase, it was strongly inhibited by the novel membrane-permeable catalase mimic TAA-1/Fe. The experimentally induced increase in cellular chelatable iron triggered a mitochondrial permeability transition (MPT) as assessed using double-staining with calcein and tetramethylrhodamine methyl ester. The MPT inhibitor cyclosporine A partially and the well-known inhibitor combination trifluoperazine+fructose completely inhibited the iron-induced cell injury/apoptosis. CONCLUSIONS These results show that iron per se can induce cell injury/apoptosis and that this injury is mediated via an MPT.
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Affiliation(s)
- Ursula Rauen
- Institut für Physiologische Chemie, Universitätsklinikum, Hufelandstr. 55, D-45122 Essen, Germany.
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Deicher R, Hörl WH. Vitamin C in chronic kidney disease and hemodialysis patients. Kidney Blood Press Res 2004; 26:100-6. [PMID: 12771534 DOI: 10.1159/000070991] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Increments of oxidative stress have been addressed as one potential cause for the accelerated atherosclerosis of chronic kidney disease patients. Ascorbate represents one of the most prominent antioxidants both in plasma as well as intracellulary, exerting beneficial effects by an inhibition of lipid peroxidation and by reducing endothelial dysfunction. However, in the presence of transition metals like iron, ascorbate may give rise to an increased generation of oxidants, and ascorbylation may impose additional carbonyl stress to uremic patients. Unsupplemented dialysis patients have reportedly lower plasma levels of ascorbate in comparison to healthy controls, mostly due to a loss into the dialysate or, in case of not dialyzed patients, increased urinary losses. Currently, 60 mg of ascorbate are recommended for chronic kidney disease patients, and 1-1.5 g of oral ascorbate/week in case of suspected subclinical ascorbate deficiency or 300 mg parenteral ascorbate/dialysis session, respectively. Ascorbate's role in modifying arterial blood pressure remains unclear, but anemic patients with functional iron deficiency might benefit from short-term, moderately dosed ascorbate supplements.
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Affiliation(s)
- Robert Deicher
- Universitätsklinik für Innere Medizin III, Klinische Abteilung für Nephrologie und Dialyse, Wien, Osterreich.
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Petrat F, Paluch S, Dogruöz E, Dörfler P, Kirsch M, Korth HG, Sustmann R, de Groot H. Reduction of Fe(III) ions complexed to physiological ligands by lipoyl dehydrogenase and other flavoenzymes in vitro: implications for an enzymatic reduction of Fe(III) ions of the labile iron pool. J Biol Chem 2003; 278:46403-13. [PMID: 12963736 DOI: 10.1074/jbc.m305291200] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Enzymatic reduction of physiological Fe(III) complexes of the "labile iron pool" has not been studied so far. By use of spectrophotometric assays based on the oxidation of NAD(P)H and formation of [Fe(II) (1,10-phenanthroline)3]2+ as well as by utilizing electron paramagnetic resonance spectrometry, it was demonstrated that the NAD(P)H-dependent flavoenzyme lipoyl dehydrogenase (diaphorase, EC 1.8.1.4) effectively catalyzes the one-electron reduction of Fe(III) complexes of citrate, ATP, and ADP at the expense of the co-enzymes NAD(P)H. Deactivated or inhibited lipoyl dehydrogenase did not reduce the Fe(III) complexes. Likewise, in the absence of NAD(P)H or in the presence of NAD(P)+, Fe(III) reduction could not be detected. The fact that reduction also occurred in the absence of molecular oxygen as well as in the presence of superoxide dismutase proved that the Fe(III) reduction was directly linked to the enzymatic activity of lipoyl dehydrogenase and not mediated by O2. Kinetic studies revealed different affinities of lipoyl dehydrogenase for the reduction of the low molecular weight Fe(III) complexes in the relative order Fe(III)-citrate > Fe(III)-ATP > Fe(III)-ADP (half-maximal velocities at 346-485 microm). These Fe(III) complexes were enzymatically reduced also by other flavoenzymes, namely glutathione reductase (EC 1.6.4.2), cytochrome c reductase (EC 1.6.99.3), and cytochrome P450 reductase (EC 1.6.2.4) with somewhat lower efficacy. The present data suggest a (patho)physiological role for lipoyl dehydrogenase and other flavoenzymes in intracellular iron metabolism.
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Affiliation(s)
- Frank Petrat
- Institut für Physiologische Chemie, Universitätsklinikum, Hufelandstrasse 55, D-45122 Essen, Germany
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