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Abarikwu SO, Oruitemeka S, Uwadileke IA, Omeodu SI, Okoye NF, Mgbudom-Okah CJ, Ohanador R. Oral administration of cadmium depletes intratesticular and epididymal iron levels and inhibits lipid peroxidation in the testis and epididymis of adult rats. J Trace Elem Med Biol 2018; 48:213-223. [PMID: 29773184 DOI: 10.1016/j.jtemb.2018.04.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 04/07/2018] [Accepted: 04/11/2018] [Indexed: 12/27/2022]
Abstract
Cadmium (Cd)-induced tissue injury depends on the accumulated Cd which differentially affects endogenous iron (Fe). To investigate this, adult rats were treated by oral gavage with Cd (50 mg/kg body wt.) once a week for 15, 30 and 60 days and sacrificed a day after last administration. After the 15th and 30th day of treatment, Cd had no effect on thiobarbituric acid reactive substances (TBARS) and endogenous Fe levels but exhibited anti-androgenic effects (p < 0.05) and caused histological damages. At day 60, Cd was accumulated by 156.30% and 364.77% above control values at concentrations that decreased endogenous Fe levels by 46.41% and 50.31% in the testis and epididymis respectively. The histological damages were characterized by decreased tubular diameter, damage to the epithelium leading to loss of tubular germ cells and absent of spermatozoa in the epididymal lumen. Although myeloperoxidase activities were increased, TBARS levels were found to decrease significantly at day 60 in the serum, testis and epididymis suggesting that the histological damages were not caused by lipid peroxidation. Furthermore, TBARS correlated negatively with Cd in the testis (r = -0.251, p < 0.05) and epididymis (r = -0.286, p < 0.05); Fe correlated positively with TBARS in the testis (r = +0.217, p < 0.05) and Cd correlated negatively with Fe in the testis (r = -0.461, p < 0.05) and epididymis (r = -0.109, p < 0.05). The antioxidant enzymes, superoxide dismutase and glutathione peroxidase were also decreased in the gonads after 60 days Cd treatment. Overall, anti-androgenic effects and histo-pathological changes are early indicators of direct effects of Cd and occur before decrease in TBARS which is secondarily related to the modifying of Fe contents.
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Affiliation(s)
- Sunny O Abarikwu
- Department of Biochemistry, University of Port Harcourt, Choba, Nigeria.
| | - Sarah Oruitemeka
- Department of Biochemistry, University of Port Harcourt, Choba, Nigeria
| | | | - Stephen I Omeodu
- Department of Biochemistry, University of Port Harcourt, Choba, Nigeria
| | - Ngozi F Okoye
- Department of Biochemistry, University of Port Harcourt, Choba, Nigeria
| | | | - Robinson Ohanador
- Department of Biochemistry, University of Port Harcourt, Choba, Nigeria
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2
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Affiliation(s)
- Leo R Zacharski
- Department of Medicine, Dartmouth Hitchcock Medical Center, Lebanon, NH, USA.
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Zhou Y, Harrison DE, Love-Myers K, Chen Y, Grider A, Wickwire K, Burgess JR, Stochelski MA, Pazdro R. Genetic analysis of tissue glutathione concentrations and redox balance. Free Radic Biol Med 2014; 71:157-164. [PMID: 24613380 PMCID: PMC4043295 DOI: 10.1016/j.freeradbiomed.2014.02.027] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Revised: 02/19/2014] [Accepted: 02/27/2014] [Indexed: 12/12/2022]
Abstract
Glutathione redox balance-defined as the ratio GSH/GSSG-is a critical regulator of cellular redox state, and declines in this ratio are closely associated with oxidative stress and disease. However, little is known about the impact of genetic variation on this trait. Previous mouse studies suggest that tissue GSH/GSSG is regulated by genetic background and is therefore heritable. In this study, we measured glutathione concentrations and GSH/GSSG in liver and kidney of 30 genetically diverse inbred mouse strains. Genetic background caused an approximately threefold difference in hepatic and renal GSH/GSSG between the most disparate strains. Haplotype association mapping determined the loci associated with hepatic and renal glutathione phenotypes. We narrowed the number of significant loci by focusing on those located within protein-coding genes, which we now consider to be candidate genes for glutathione homeostasis. No candidate genes were associated with both hepatic and renal GSH/GSSG, suggesting that genetic regulation of GSH/GSSG occurs predominantly in a tissue-specific manner. This is the first quantitative trait locus study to examine the genetic regulation of glutathione concentrations and redox balance in mammals. We identified novel candidate genes that have the potential to redefine our knowledge of redox biochemistry and its regulation and inform future therapeutic applications.
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Affiliation(s)
- Yang Zhou
- Department of Foods and Nutrition and University of Georgia, Athens, GA 30602, USA
| | | | | | - Yi Chen
- Department of Statistics, University of Georgia, Athens, GA 30602, USA
| | - Arthur Grider
- Department of Foods and Nutrition and University of Georgia, Athens, GA 30602, USA
| | - Kathie Wickwire
- Department of Foods and Nutrition and University of Georgia, Athens, GA 30602, USA
| | - John R Burgess
- Department of Nutrition Science, Purdue University, West Lafayette, IN 47907, USA
| | - Mateusz A Stochelski
- Department of Nutrition Science, Purdue University, West Lafayette, IN 47907, USA
| | - Robert Pazdro
- Department of Foods and Nutrition and University of Georgia, Athens, GA 30602, USA; The Jackson Laboratory, Bar Harbor, ME 04609, USA.
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Lang DH, Gerhard GS, Griffith JW, Vogler GP, Vandenbergh DJ, Blizard DA, Stout JT, Lakoski JM, McClearn GE. Quantitative trait loci (QTL) analysis of longevity in C57BL/6J by DBA/2J (BXD) recombinant inbred mice. Aging Clin Exp Res 2010; 22:8-19. [PMID: 20305363 DOI: 10.1007/bf03324809] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
BACKGROUND AND AIMS Genes associated with longevity have been identified using both single gene and genome-wide approaches in a variety of species. The aim of this study was to identify quantitative trait loci (QTLs) that influence longevity in male and female mice from twenty-three C57BL/6J by DBA/2J (BXD) recombinant inbred (RI) strains. METHODS Approximately 12 animals of each sex for each RI strain were maintained under standard conditions until natural death or moribundity criteria were met. RESULTS A number of life span-relevant loci previously reported on chromosomes (Chrs) 7, 8, 10 and 11 were confirmed. In addition, 5 previously unreported QTLs for mouse life span on Chrs 1, 2, 6, 11, and X were identified as significant and 3 QTLs on Chrs 5, 8, and 16 were suggestive. CONCLUSIONS Several QTLs were coincident in males and females although the modest correlation between male and female median lifespans and the identification of sex specific QTLs provide evidence that the genetic architecture underlying longevity in the sexes may differ substantially. The identification of multiple QTLs for longevity will provide valuable resources for both reductionist and integrationist research into mechanisms of life span determination.
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Affiliation(s)
- Dean H Lang
- The Biomechanics Laboratory, Department of Kinesiology, College of Health and Human Development, The Pennsylvania State University, University Park, PA, USA.
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Jones BC, Beard JL, Gibson JN, Unger EL, Allen RP, McCarthy KA, Earley CJ. Systems genetic analysis of peripheral iron parameters in the mouse. Am J Physiol Regul Integr Comp Physiol 2007; 293:R116-24. [PMID: 17475678 DOI: 10.1152/ajpregu.00608.2006] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Iron homeostasis is one of the most critical functions in living systems. Too little iron can lead to anemia and tissue-specific disorders, such as splenomegaly. Excessive systemic iron is characteristic of hemochromatosis and is implicated in the brain in Parkinson's disease. With the exception of some single gene diseases like hemochromatosis, we know little about genetic-based, individual differences in iron-related parameters and their impact on biology. To model genetic control of iron homeostasis, we measured liver, spleen, and plasma iron concentrations, hematocrit and hemoglobin, transferrin saturation, and total iron-binding capacity in several BXD/Ty recombinant inbred mouse strains derived from C57BL/6 and DBA/2 progenitors. At 120 days of age, the animals were killed for iron analysis. All measures showed genetic-based variability consistent with polygenic influence. Analysis of principal components of the seven measures revealed three factors that we named availability, transport, and storage. Quantitative trait loci (QTL) analysis revealed one suggestive QTL on chromosome 5 for availability, two suggestive QTL (one on chromosome 1 and the other on chromosome 7) for transport, and one weak QTL on chromosome 2 for storage. The results show that iron homeostasis is a complex trait and is influenced by multiple genes.
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Affiliation(s)
- Byron C Jones
- Department of Biobehavioral Health, The Pennsylvania State University, University Park, PA 16827, USA.
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Andziak B, Buffenstein R. Disparate patterns of age-related changes in lipid peroxidation in long-lived naked mole-rats and shorter-lived mice. Aging Cell 2006; 5:525-32. [PMID: 17129214 DOI: 10.1111/j.1474-9726.2006.00246.x] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
A key tenet of the oxidative stress theory of aging is that levels of accrued oxidative damage increase with age. Differences in damage generation and accumulation therefore may underlie the natural variation in species longevity. We compared age-related profiles of whole-organism lipid peroxidation (urinary isoprostanes) and liver lipid damage (malondialdehyde) in long living naked mole-rats [maximum lifespan (MLS) > 28.3 years] and shorter-living CB6F1 hybrid mice (MLS approximately 3.5 years). In addition, we compared age-associated changes in liver non-heme iron to assess how intracellular conditions, which may modulate oxidative processes, are affected by aging. Surprisingly, even at a young age, concentrations of both markers of lipid peroxidation, as well as of iron, were at least twofold (P < 0.005) greater in naked mole tats than in mice. This refutes the hypothesis that prolonged naked mole-rat longevity is due to superior protection against oxidative stress. The age-related profiles of all three parameters were distinctly species specific. Rates of lipid damage generation in mice were maintained throughout adulthood, while accrued damage in old animals was twice that of young mice. In naked mole-rats, urinary isoprostane excretion declined by half with age (P < 0.001), despite increases in tissue iron (P < 0.05). Contrary to the predictions of the oxidative stress theory, lipid damage levels did not change with age in mole-rats. These data suggest that the patterns of age-related changes in levels of markers of oxidative stress are species specific, and that the pronounced longevity of naked mole-rats is independent of oxidative stress parameters.
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Affiliation(s)
- Blazej Andziak
- Department of Biology, The City College of the City University of New York, New York, NY 10031, USA
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7
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Rebrin I, Forster MJ, Sohal RS. Effects of age and caloric intake on glutathione redox state in different brain regions of C57BL/6 and DBA/2 mice. Brain Res 2006; 1127:10-8. [PMID: 17113050 PMCID: PMC2112744 DOI: 10.1016/j.brainres.2006.10.040] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2006] [Revised: 10/11/2006] [Accepted: 10/20/2006] [Indexed: 11/22/2022]
Abstract
The main purpose of the present study was to determine whether specific regions of the mouse brain exhibit different age-related changes in oxidative stress, as indicated by glutathione redox state and the level of protein-glutathionyl mixed disulfides. Comparison of 3- and 21-month-old mice indicated an age-related decrease in the ratio of reduced to oxidized glutathione (GSH/GSSG) as well as a pro-oxidizing shift in the calculated redox potential (ranging from 6 to 15 mV) in the cortex, hippocampus, striatum and cerebellum, whereas there was little change in the brainstem. This pro-oxidizing shift in redox state was due to a modest decrease in GSH content occurring in all the brain regions examined, and elevations in GSSG amount that were most pronounced in the striatum and cerebellum. The regional changes in glutathione redox state were paralleled by increases in the amounts of protein-mixed disulfides. A reduction of caloric intake by 40% for a short period (7 weeks), implemented in relatively old mice (17 months), increased the GSH/GSSG ratio and redox potential at 19 months in the same brain regions that exhibited age-related decreases. The effects of age and caloric restriction were qualitatively similar in C57BL/6 and DBA/2 mice. However, young DBA/2 mice, which do not show extension of life span in response to long-term caloric restriction, had lower GSH/GSSG ratios and higher protein-mixed disulfides than age-matched C57BL/6 mice. The current findings demonstrate that oxidative stress, as reflected by glutathione redox state, increases in the aging brain in regions linked to age-associated losses of function and neurodegenerative diseases.
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Affiliation(s)
- Igor Rebrin
- Department of Molecular Pharmacology and Toxicology, University of Southern California, Los Angeles, CA 90089, USA
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Grant GR, Robinson SW, Edwards RE, Clothier B, Davies R, Judah DJ, Broman KW, Smith AG. Multiple polymorphic loci determine basal hepatic and splenic iron status in mice. Hepatology 2006; 44:174-85. [PMID: 16799992 DOI: 10.1002/hep.21233] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Polymorphisms of genes linked to iron metabolism may account for individual variability in hemochromatosis and iron status connected with liver and cardiovascular diseases, cancers, toxicity, and infection. Mouse strains exhibit marked differences in levels of non-heme iron, with C57BL/6J and SWR showing low and high levels, respectively. The genetic basis for this variability was examined using quantitative trait loci (QTL) analysis together with expression profiling and chromosomal positions of known iron-related genes. Non-heme iron levels in liver and spleen of C57BL/6J x SWR F2 mice were poorly correlated, indicating independent regulation. Highly significant (P < .01) polymorphic loci were found on chromosomes 2 and 16 for liver and on chromosomes 8 and 9 for spleen. With sex as a covariate, additional significant or suggestive (P < 0.1) QTL were detected on chromosomes 7, 8, 11, and 19 for liver and on chromosome 2 for spleen. A gene array showed no clear association between most loci and differential iron-related gene expression. The gene for transferrin and a transferrin-like gene map close to the QTL on chromosome 9. Transferrin saturation was significantly lower in C57BL/6J mice than in SWR mice, but there was no significant difference in the serum level of transferrin, hepatic expression, or functional change in cDNA sequence. beta2-Microglobulin, which, unlike other loci, was associated with C57BL/6J alleles, is a candidate for the chromosome 2 QTL for higher iron. In conclusion, the findings show the location of polymorphic genes that determine basal iron status in wild-type mice. Human equivalents may be pertinent in predisposition to hepatic and other disorders.
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Affiliation(s)
- Gemma R Grant
- MRC Toxicology Unit, University of Leicester, Leicester, UK
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9
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Grundy MA, Gorman N, Sinclair PR, Chorney MJ, Gerhard GS. High-throughput non-heme iron assay for animal tissues. ACTA ACUST UNITED AC 2005; 59:195-200. [PMID: 15163531 DOI: 10.1016/j.jbbm.2004.01.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2003] [Revised: 12/17/2003] [Accepted: 01/12/2004] [Indexed: 10/26/2022]
Abstract
Iron has been widely studied in nearly every realm of biology. However, current methodologies, such as genetic mapping or mutation screening, have been difficult to apply due to the lack of robust high-throughput methods for quantifying iron levels from cells or tissues. The measurement of total iron levels in tissues, usually done with atomic absorption spectroscopy, is impractical for large numbers of samples and includes the contribution of heme iron from hemoglobin contained in red blood cells. The measurement of non-heme iron by reaction with a bathophenanthroline reagent, a commonly used assay reported more than 30 years ago, is also not feasible for large-scale analyses because it is cuvette-based. We therefore have modified this method to a microplate format that will facilitate large-scale analysis. The microplate assay is highly sensitive and specific, and is a simple and effective method for the measurement of non-heme iron for animal tissues that will enable the application of high-throughput of genetic methodologies.
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Affiliation(s)
- Martin A Grundy
- Department of Pathology, Dartmouth Medical School, Lebanon, NH 03756, USA
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10
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Gerhard GS, Chorney MJ. Genes for gestational iron loading? Gastroenterology 2004; 127:1861; author reply 1861-2. [PMID: 15578533 DOI: 10.1053/j.gastro.2004.10.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
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Malek RL, Sajadi H, Abraham J, Grundy MA, Gerhard GS. The effects of temperature reduction on gene expression and oxidative stress in skeletal muscle from adult zebrafish. Comp Biochem Physiol C Toxicol Pharmacol 2004; 138:363-73. [PMID: 15533794 DOI: 10.1016/j.cca.2004.08.014] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2004] [Revised: 08/06/2004] [Accepted: 08/28/2004] [Indexed: 01/11/2023]
Abstract
Longevity is inversely proportional to ambient temperature in ectothermic organisms such as fish. However, the mechanism by which reducing temperature over a physiological range increases life span is not known and available data are derived primarily from invertebrates. With a rodent-like longevity and abundant biological resources, the zebrafish is an ideal vertebrate ectothermic model in which to investigate this phenomenon. As an initial approach, the effects of a year-long 10 degrees C reduction in water temperature on global gene expression in tail skeletal muscle from adult zebrafish were determined using an oligonucleotide microarray representing 15,512 genes. Expression levels for approximately 600 genes were up-regulated by 1.7-fold or greater by the reduction in temperature, while a similar number of transcripts were down regulated by more than 1.7-fold. Using gene ontology (GO) classifications for molecular function, two functional groups, "oxygen and reactive oxygen species metabolism" and "response to oxidative stress," were found to be overrepresented among up-regulated genes. Transcripts levels for the genes in these two categories were increased by temperature reduction (TR). However, temperature reduction did not suppress lipid peroxidation potential, protein carbonyl content, or 8-oxoguanine level. Additional studies will be required to further delineate the role of altered gene expression and oxidative stress on the longevity-promoting effects of temperature reduction.
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Affiliation(s)
- Renae L Malek
- The Institute for Genomic Research, 9712 Medical Center Drive, Rockville, MD 20850, USA
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Xin MG, Zhang J, Block ER, Patel JM. Senescence-enhanced oxidative stress is associated with deficiency of mitochondrial cytochrome c oxidase in vascular endothelial cells. Mech Ageing Dev 2004; 124:911-9. [PMID: 14499496 DOI: 10.1016/s0047-6374(03)00163-5] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Cellular senescence-elevated oxidative stress plays a critical role in age-associated vascular endothelial dysfunction. We investigated whether deficiency of mitochondrial cytochrome c oxidase (complex IV) is causally linked to increased oxidant generation during cellular aging using senescent (passage 45) and young (passage 3) pulmonary artery endothelial cells (PAEC). In senescent PAEC, levels of O2- and H2O2 were elevated onefold, respectively, compared to those in young cells. Lipid peroxidation and protein carbonyl contents in aged cells were increased more than twofold compared to young cells. To determine whether lack of complex IV in senescent cells contributed to the increased oxidant generation, complex IV activity in young cells was specifically inhibited using antisense oligonucleotides directed against the mRNA of complex IV subunits. Levels of O2- and H2O2 in PAEC treated with antisense oligonucleotides were elevated onefold, respectively, which correlated with a similar increase in lipid (110%) and protein (20%) oxidation, compared to control oligonucleotides-transfected cells. Moreover, levels of nitrosylated proteins in antisense-transfected cells were increased 30%, compared to controls. These data demonstrate that deficiency of complex IV in senescent cells enhances oxidative and nitrosative stress, which may be responsible for senescence-induced endothelial cell loss and dysfunction.
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Affiliation(s)
- Mei-Guo Xin
- Department of Medicine, University of Florida College of Medicine, 1600 S.W. Archer Road, Gainesville, FL 32610-0225, USA
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13
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Oxenkrug GF, Requintina PJ. Mating attenuates aging-associated increase of lipid peroxidation activity in C57BL/6J mice. Ann N Y Acad Sci 2003; 993:161-7; discussion 195-6. [PMID: 12853310 DOI: 10.1111/j.1749-6632.2003.tb07526.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
In the frame of the free-radical hypothesis of aging and literature data on increased life span of mated animals, we evaluated brain, kidney, and liver lipid peroxidation in C57Bl/6J mice of various ages and compared lipid peroxidation activity in mated and non-mated mice of both genders. An aging-associated increase (from 3 to 12 months of age) of lipid peroxidation, as measured by malonaldehyde and 4-hydroxyalkenals (MDA + HAE) levels, was observed in the liver and kidney, but not in the brain. Tissue MDA + HAE levels were lower in 12-month old mated mice (housed with animals of opposite gender from three to five months of age) than in 12-month old non-mated animals. There were no gender differences in the observed effect. It is suggested that mating might attenuate the increase of lipid peroxidation associated with aging.
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Affiliation(s)
- Gregory F Oxenkrug
- Pineal Research Laboratory, Department of Psychiatry, St. Elizabeth's Medical Center, Boston, Massachusets 02135, USA.
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Meyer PN, Gerhard GS, Yoshida Y, Yoshida M, Chorney KA, Beard J, Kauffman EJ, Weiss G, Chorney MJ. Hemochromatosis protein (HFE) and tumor necrosis factor receptor 2 (TNFR2) influence tissue iron levels: elements of a common gut pathway? Blood Cells Mol Dis 2002; 29:274-85. [PMID: 12547217 DOI: 10.1006/bcmd.2002.0565] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Quantitative genetic analysis of hepatic and splenic iron levels in recombinant inbred mice yielded a quantitative trait locus that was found to coincide with the genomic locale encompassing the tumor necrosis factor receptor 2 gene (Tnfr2). When fed an iron-enriched diet, mice nullizygous with respect to Tnfr2, but not the Tnfr1 gene, showed a significant increase in splenic non-heme iron levels. This result contrasted with mice deficient in the hemochromatosis protein, HFE, which demonstrated a significant increase in normally high hepatic iron levels, but no change in splenic iron, when fed an iron-enriched chow. Both Tnfr2 knockout and HFE knockout mice fed an iron-enriched diet failed to demonstrate intestinal epithelial cell iron following the application of the Perls' stain, as compared to both Tnfr1 knockout and normal control mice. Moreover, intestinal intraepithelial lymphocytes (IELs) isolated from HFE knockout mice did not show an increase in TNF expression following challenge with the iron-enriched diet, in contrast to normal controls. These results suggest that HFE and TNFR2 are both involved in regulating iron deposition in tissues and that the regulation occurs at the level of the intestine through IEL-orchestrated production of TNF following the binding to TNFR2. These data suggest that HFE and TNFR2 may contribute to a common pathway of the iron stores regulator insuring the controlled efflux of gut iron.
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Affiliation(s)
- Paul N Meyer
- H107, Department of Microbiology and Immunology, Pennsylvania State University College of Medicine, 500 University Drive, Hershey, PA 17033, USA
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