51
|
Fujii J, Imai H. Redox reactions in mammalian spermatogenesis and the potential targets of reactive oxygen species under oxidative stress. SPERMATOGENESIS 2014; 4:e979108. [PMID: 26413390 PMCID: PMC4581049 DOI: 10.4161/21565562.2014.979108] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Accepted: 10/16/2014] [Indexed: 01/13/2023]
Abstract
Reduction-oxidation (Redox) reactions are ubiquitous mechanisms for vital activities in all organisms, and they play pivotal roles in the regulation of spermatogenesis as well. Here we focus on 3 redox-involved processes that have drawn much recent attention: the regulation of signal transduction by reactive oxygen species (ROS) such as hydrogen peroxide, oxidative protein folding in the endoplasmic reticulum (ER), and sulfoxidation of protamines during sperm chromatin condensation. The first 2 of these processes are emerging topics in cell biology and are applicable to most living cells, which includes spermatogenic cells. The roles of ROS in signal transduction have been elucidated in the last 2 decades and have received broad attention, most notably from the viewpoint of the proper control of mitotic signals. Redox processes in the ER are important because this is the organelle where secretory and membrane proteins are synthesized and proceed toward their functional structure, so that malfunction of the ER affects not only the involved cells but also the accepting cells of the secreted proteins in multicellular organisms. Sulfoxidation is the third of these processes, and the sulfoxidation of chromatin is a unique process in sperm maturation. During recent sulfoxidase research, GPX4 has emerged as a promising enzyme that plays essential roles in the production of fertile sperm, but the involvement of other redox proteins is also becoming evident. Because the molecules involved in the redox reactions are prone to oxidation, they can be sensitive to oxidative damage, which makes them potential targets for antioxidant therapy.
Collapse
Affiliation(s)
- Junichi Fujii
- Department of Biochemistry and Molecular Biology; Graduate School of Medical Science; Yamagata University; Yamagata, Japan
| | - Hirotaka Imai
- School of Pharmaceutical Sciences; Kitasato University; Minato-ku, Tokyo, Japan
| |
Collapse
|
52
|
Ahsan U, Kamran Z, Raza I, Ahmad S, Babar W, Riaz MH, Iqbal Z. Role of selenium in male reproduction - a review. Anim Reprod Sci 2014; 146:55-62. [PMID: 24613013 DOI: 10.1016/j.anireprosci.2014.01.009] [Citation(s) in RCA: 144] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Revised: 01/16/2014] [Accepted: 01/20/2014] [Indexed: 01/17/2023]
Abstract
The role of Se and various selenoproteins in male reproductive performance is reviewed. Development of male reproductive tissue requires an optimal level of Se in testis, and a small deviation, either deficiency or excess, leads to abnormal development. Selenium is a constituent of selenoproteins including GPx1, GPx3, mGPx4, cGPx4, and GPx5 that protect against oxidative damage to spermatozoa throughout the process of sperm maturation, whereas selenoproteins, such as mGPx4 and snGPx4, serve as structural components of mature spermatozoa. Thus Se and selenoproteins ensure viability of spermatozoa as well as providing protection against reactive oxygen species. Gene knock-out studies of selenoproteins revealed that their absence during spermatogenesis results in abnormal spermatozoa, which in turn affects semen quality and fertility. Deviation from the optimal quantities of dietary Se, both above or below, may cause multiple abnormalities of spermatozoa and affect motility and fertility. Libido may also be increased by Se. Dietary Se should be in optimal quantity to maintain reproductive function in males and to avoid infertility.
Collapse
Affiliation(s)
- U Ahsan
- University College of Veterinary and Animal Sciences, The Islamia University of Bahawalpur, Bahawalpur 63100, Pakistan
| | - Z Kamran
- University College of Veterinary and Animal Sciences, The Islamia University of Bahawalpur, Bahawalpur 63100, Pakistan.
| | - I Raza
- University College of Veterinary and Animal Sciences, The Islamia University of Bahawalpur, Bahawalpur 63100, Pakistan
| | - S Ahmad
- University College of Veterinary and Animal Sciences, The Islamia University of Bahawalpur, Bahawalpur 63100, Pakistan
| | - W Babar
- University College of Veterinary and Animal Sciences, The Islamia University of Bahawalpur, Bahawalpur 63100, Pakistan
| | - M H Riaz
- University College of Veterinary and Animal Sciences, The Islamia University of Bahawalpur, Bahawalpur 63100, Pakistan
| | - Z Iqbal
- Institute of Animal Nutrition and Feed Technology, University of Agriculture, Faisalabad 38040, Pakistan
| |
Collapse
|
53
|
Erkekoglu P, Giray B, Rachidi W, Hininger-Favier I, Roussel AM, Favier A, Hincal F. Effects of di(2-ethylhexyl)phthalate on testicular oxidant/antioxidant status in selenium-deficient and selenium-supplemented rats. ENVIRONMENTAL TOXICOLOGY 2014; 29:98-107. [PMID: 21976414 DOI: 10.1002/tox.20776] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2011] [Revised: 08/25/2011] [Accepted: 08/31/2011] [Indexed: 05/31/2023]
Abstract
Di(ethylhexyl)phthalate (DEHP), the most widely used plasticizer, was investigated to determine whether an oxidative stress process was one of the underlying mechanisms for its testicular toxicity potential. To evaluate the effects of selenium (Se), status on the toxicity of DEHP was further objective of this study, as Se is known to play a critical role in testis and in the modulation of intracellular redox equilibrium. Se deficiency was produced in 3-weeks-old Sprague-Dawley rats feeding them ≤0.05 mg Se /kg diet for 5 weeks, and Se-supplementation group was on 1 mg Se/kg diet. DEHP-treated groups received 1000 mg/kg dose by gavage during the last 10 days of the feeding period. Activities of antioxidant selenoenzymes [glutathione peroxidase 1 (GPx1), glutathione peroxidase 4 (GPx4), thioredoxin reductase (TrxR)], catalase (CAT), superoxide dismutase (SOD), and glutathione S-transferase (GST); concentrations of reduced glutathione (GSH), oxidized glutathione (GSSG), and thus the GSH/GSSG redox ratio; and thiobarbituric acid reactive substance (TBARS) levels were measured. DEHP was found to induce oxidative stress in rat testis, as evidenced by significant decrease in GSH/GSSG redox ratio (>10-fold) and marked increase in TBARS levels, and its effects were more pronounced in Se-deficient rats with ∼18.5-fold decrease in GSH/GSSG redox ratio and a significant decrease in GPx4 activity, whereas Se supplementation was protective by providing substantial elevation of redox ratio and reducing the lipid peroxidation. These findings emphasized the critical role of Se as an effective redox regulator and the importance of Se status in protecting testicular tissue from the oxidant stressor activity of DEHP.
Collapse
Affiliation(s)
- Pınar Erkekoglu
- Hacettepe University, Faculty of Pharmacy, Department of Toxicology, 06100 Ankara, Turkey
| | | | | | | | | | | | | |
Collapse
|
54
|
Roman M, Jitaru P, Barbante C. Selenium biochemistry and its role for human health. Metallomics 2014; 6:25-54. [DOI: 10.1039/c3mt00185g] [Citation(s) in RCA: 421] [Impact Index Per Article: 42.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
55
|
Michaelis M, Gralla O, Behrends T, Scharpf M, Endermann T, Rijntjes E, Pietschmann N, Hollenbach B, Schomburg L. Selenoprotein P in seminal fluid is a novel biomarker of sperm quality. Biochem Biophys Res Commun 2014; 443:905-10. [DOI: 10.1016/j.bbrc.2013.12.067] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2013] [Accepted: 12/11/2013] [Indexed: 01/09/2023]
|
56
|
Zhang L, Zhou ZQ, Li G, Fu MZ. The effect of deposition Se on the mRNA expression levels of GPxs in goats from a Se-enriched county of China. Biol Trace Elem Res 2013; 156:111-23. [PMID: 24072670 DOI: 10.1007/s12011-013-9830-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Accepted: 09/16/2013] [Indexed: 01/18/2023]
Abstract
Previous studies revealed that Se was an important regulatory factor for glutathione peroxidase (GPx) genes. However, the relationship between Se concentrations and mRNA expression levels of GPxs were unclear in goats, especially the goats living in natural Se-enriched area. Thus, the aim of this study was to determine the Se concentrations and the mRNA expression levels of GPx-1, GPx-2, GPx-3, and GPx-4 in goats from Ziyang County (ZY-H and ZY-L goats) and Baoji City (BJ-P goats), which were Se-rich region and Se-poor region in China, respectively. Atomic fluorescence spectrometry was used as an essential method to determine the Se concentrations in heart, liver, spleen, lung, kidney, longissimus, biceps femoris, and serum, and the gene expressions were quantified in mRNA samples extracted from the above tissues by real-time quantitative reverse transcription-polymerase chain reaction. We found that the Se concentrations in ZY-H and ZY-L goats were higher than that in BJ-P goats significantly (P < 0.05), and the pertinence relations of Se levels between serum and heart, liver, spleen, and kidney were significant (P < 0.05). The mRNA levels of GPx-1 in ZY-H and ZY-L goats were higher than that in BJ-P goats very significantly (P < 0.01) except for longissimus (P < 0.05). Our results indicated a significant trend for GPx-2 in the direction of increasing mRNA levels with increasing Se concentrations in goats but had no statistical significance (P > 0.05) in our experimental conditions. As to GPx-3, its mRNA expression in spleen, lung, and kidney (P < 0.05) were upregulated and were consensual to high Se contents in ZY-H goats, but no significant effects were observed in heart, liver, longissimus, and biceps femoris among our three groups (P > 0.05). The mRNA levels of GPx-4 in heart, liver, lung, and kidney of ZY-H and ZY-L goats were higher than that of BJ-P goats (P < 0.05), and the difference was very significant in lung especially (P < 0.01), but no change in spleen, longissimus, and biceps femoris (P > 0.05). In summary, these data suggested that the goats living in Ziyang County were rich in Se, and the deposition Se played important roles in the mRNA expression of GPx-1, GPx-3, and GPx-4 in certain tissues of goats differentially.
Collapse
Affiliation(s)
- Lei Zhang
- College of Animal Science and Technology, Northwest A & F University, Yangling, Xianyang, Shaanxi, 712100, China,
| | | | | | | |
Collapse
|
57
|
Wang G, Wu Y, Zhou T, Guo Y, Zheng B, Wang J, Bi Y, Liu F, Zhou Z, Guo X, Sha J. Mapping of the N-Linked Glycoproteome of Human Spermatozoa. J Proteome Res 2013; 12:5750-9. [DOI: 10.1021/pr400753f] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Gaigai Wang
- State Key Laboratory of Reproductive
Medicine, Department of Histology and Embryology, Nanjing Medical University, Nanjing 210029, China
| | - Yibo Wu
- State Key Laboratory of Reproductive
Medicine, Department of Histology and Embryology, Nanjing Medical University, Nanjing 210029, China
| | - Tao Zhou
- State Key Laboratory of Reproductive
Medicine, Department of Histology and Embryology, Nanjing Medical University, Nanjing 210029, China
| | - Yueshuai Guo
- State Key Laboratory of Reproductive
Medicine, Department of Histology and Embryology, Nanjing Medical University, Nanjing 210029, China
| | - Bo Zheng
- State Key Laboratory of Reproductive
Medicine, Department of Histology and Embryology, Nanjing Medical University, Nanjing 210029, China
| | - Jing Wang
- State Key Laboratory of Reproductive
Medicine, Department of Histology and Embryology, Nanjing Medical University, Nanjing 210029, China
| | - Ye Bi
- State Key Laboratory of Reproductive
Medicine, Department of Histology and Embryology, Nanjing Medical University, Nanjing 210029, China
| | - Fangjuan Liu
- State Key Laboratory of Reproductive
Medicine, Department of Histology and Embryology, Nanjing Medical University, Nanjing 210029, China
| | - Zuomin Zhou
- State Key Laboratory of Reproductive
Medicine, Department of Histology and Embryology, Nanjing Medical University, Nanjing 210029, China
| | - Xuejiang Guo
- State Key Laboratory of Reproductive
Medicine, Department of Histology and Embryology, Nanjing Medical University, Nanjing 210029, China
| | - Jiahao Sha
- State Key Laboratory of Reproductive
Medicine, Department of Histology and Embryology, Nanjing Medical University, Nanjing 210029, China
| |
Collapse
|
58
|
Oxidative stress and redox regulation of gametogenesis, fertilization, and embryonic development. Reprod Med Biol 2013; 13:71-79. [PMID: 29699151 DOI: 10.1007/s12522-013-0170-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2013] [Accepted: 09/18/2013] [Indexed: 01/18/2023] Open
Abstract
Oxidative stress caused by elevated reactive oxygen species (ROS) is one of the predominant causes of both male and female infertility. Oxidative stress conditions cause either cell death or senescence by oxidation of cellular molecules including nucleic acid, proteins, and lipids. It is particularly important to minimize oxidative stress when in vitro fertilization is performed for the purpose of assisted reproduction. The problems associated with assisted reproductive technology are becoming evident, and it is now the time to clarify its mechanisms and cope with them. On the other hand, the beneficial roles of ROS, such as intracellular signaling, have become evident. The antithetical functions of ROS make it more difficult to overcome the problems caused by oxidative stress. Despite the difficulty in understanding mammalian reproduction, the mechanisms and problems can be gradually unveiled by advanced technology such as genetic modification of animals.
Collapse
|
59
|
Kilarkaje N, Al-Bader M. Effects of antioxidants on drugs used against testicular cancer-induced alterations in metastasis-associated protein 1 signaling in the rat testis. Toxicol Ind Health 2013; 32:89-97. [DOI: 10.1177/0748233713498441] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Metastasis-associated protein 1 (MTA1) is involved in tumor growth and metastasis of cancers. Being a component of nucleosome remodeling and histone deacetylase complex, the protein is also associated with DNA damage response pathway. Since the protein is involved in cancer pathology, we first investigated the effects of bleomycin, etoposide, and cisplatin (BEP) on MTA1 signaling in the testis. Second, since the antioxidants (AOs) have protective effects, we further investigated whether or not an AO cocktail modulates the effects of the drugs. Adult male Sprague Dawley rats ( N = 4) were treated either with saline, or AO (α-tocopherol, l-ascorbic acid, zinc, and selenium), or therapeutic dose levels of etoposide (15 mg/kg) and cisplatin (3 mg/kg) from day 1–4 of the week and B (1.5 mg/kg) on the second day of the week, or BEP + AO. The real-time polymerase chain reaction showed that MTA1 and MTA1s (short form) gene expression was downregulated in AO (100% and 100%), BEP (86% and 71%), and BEP + AO (97% and 93%) groups. Western blotting and immunohistochemistry results showed that unnormalized MTA1 protein expression was upregulated in AO (38%) and BEP + AO (34%) groups; however, the MTA1/β-actin ratio was upregulated in all treated groups (21, 19, and 15%, respectively). In conclusion, the results indicate that both BEP and AO suppress MTA1 and MTA1s transcription, which may render the germ cells to be more prone to apoptosis. However, upregulation of MTA1 protein expression may be related to induced DNA damage. Modulation of MTA1 signaling is a novel mechanism of action of BEP and AO, which may be useful in developing newer anticancer drugs.
Collapse
Affiliation(s)
- Narayana Kilarkaje
- Department of Anatomy, Faculty of Medicine, Kuwait University, Safat, Kuwait
| | - Maie Al-Bader
- Department of Physiology, Faculty of Medicine, Kuwait University, Safat, Kuwait
| |
Collapse
|
60
|
Al-Matary A, Hussain M, Ali J. Selenium: a brief review and a case report of selenium responsive cardiomyopathy. BMC Pediatr 2013; 13:39. [PMID: 23530936 PMCID: PMC3639060 DOI: 10.1186/1471-2431-13-39] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Accepted: 02/27/2013] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND The authors review the role of selenium and highlight possible low selenium levels in soil that may result in deficient states in Saudi Arabia. CASE PRESENTATION The authors report a case of selenium-responsive cardiomyopathy in a 15-month old Saudi Arabian boy. This case of selenium deficiency causing dilated cardiomyopathy is presented with failure to thrive, prolonged fever and respiratory distress. The investigations revealed selenium deficiency. Selenium supplementation along with anti-failure therapy [Furosimide, Captopril] was administered for 6 months. Following therapy the cardiac function, hair, skin and the general health of the patient improved significantly. CONCLUSION The patient with dilated cardiomyopathy of unknown etiology, not responding to usual medication may be deficient in selenium. Serum selenium measurements should be included in the diagnostic work-up to ensure early detection and treatment of the disease. The selenium level in the Saudi population needs be determined. Vulnerable populations have to undergo regular selenium measurements and supplementation if indicated. Dependence on processed foods suggests that the Saudi population fortify themselves with nutrient and micronutrient supplements in accordance to the RDA.
Collapse
Affiliation(s)
- Abdulrahman Al-Matary
- Department of Neonatology, King Fahad Medical City, Riyadh, Kingdom of Saudi Arabia.
| | | | | |
Collapse
|
61
|
Chatterjee A. Reduced glutathione: a radioprotector or a modulator of DNA-repair activity? Nutrients 2013; 5:525-42. [PMID: 23434907 PMCID: PMC3635210 DOI: 10.3390/nu5020525] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Revised: 12/15/2012] [Accepted: 01/31/2013] [Indexed: 11/17/2022] Open
Abstract
The tripeptide glutathione (GSH) is the most abundant intracellular nonprotein thiol, and it is involved in many cellular functions including redox-homeostatic buffering. Cellular radiosensitivity has been shown to be inversely correlated to the endogenous level of GSH. On the other hand, controversy is raised with respect to its role in the field of radioprotection since GSH failed to provide consistent protection in several cases. Reports have been published that DNA repair in cells has a dependence on GSH. Subsequently, S-glutathionylation (forming mixed disulfides with the protein-sulfhydryl groups), a potent mechanism for posttranslational regulation of a variety of regulatory and metabolic proteins when there is a change in the celluar redox status (lower GSH/GSSG ratio), has received increased attention over the last decade. GSH, as a single agent, is found to affect DNA damage and repair, redox regulation and multiple cell signaling pathways. Thus, seemingly, GSH does not only act as a radioprotector against DNA damage induced by X-rays through glutathionylation, it may also act as a modulator of the DNA-repair activity. Judging by the number of publications within the last six years, it is obvious that the field of protein glutathionylation impinges on many aspects of biology, from regulation of protein function to roles of cell cycle and apoptosis. Aberrant protein glutathionylation and its association with cancer and other diseases is an area of increasing interest.
Collapse
Affiliation(s)
- Anupam Chatterjee
- Department of Biotechnology & Bioinformatics, North-Eastern Hill University, Shillong 793022, India.
| |
Collapse
|
62
|
Rezvanfar MA, Rezvanfar MA, Shahverdi AR, Ahmadi A, Baeeri M, Mohammadirad A, Abdollahi M. Protection of cisplatin-induced spermatotoxicity, DNA damage and chromatin abnormality by selenium nano-particles. Toxicol Appl Pharmacol 2012; 266:356-65. [PMID: 23260366 DOI: 10.1016/j.taap.2012.11.025] [Citation(s) in RCA: 126] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Revised: 11/01/2012] [Accepted: 11/26/2012] [Indexed: 12/28/2022]
Abstract
Cisplatin (CIS), an anticancer alkylating agent, induces DNA adducts and effectively cross links the DNA strands and so affects spermatozoa as a male reproductive toxicant. The present study investigated the cellular/biochemical mechanisms underlying possible protective effect of selenium nano-particles (Nano-Se) as an established strong antioxidant with more bioavailability and less toxicity, on reproductive toxicity of CIS by assessment of sperm characteristics, sperm DNA integrity, chromatin quality and spermatogenic disorders. To determine the role of oxidative stress (OS) in the pathogenesis of CIS gonadotoxicity, the level of lipid peroxidation (LPO), antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) and peroxynitrite (ONOO) as a marker of nitrosative stress (NS) and testosterone (T) concentration as a biomarker of testicular function were measured in the blood and testes. Thirty-two male Wistar rats were equally divided into four groups. A single IP dose of CIS (7 mg/kg) and protective dose of Nano-Se (2 mg/kg/day) were administered alone or in combination. The CIS-exposed rats showed a significant increase in testicular and serum LPO and ONOO level, along with a significant decrease in enzymatic antioxidants levels, diminished serum T concentration and abnormal histologic findings with impaired sperm quality associated with increased DNA damage and decreased chromatin quality. Coadministration of Nano-Se significantly improved the serum T, sperm quality, and spermatogenesis and reduced CIS-induced free radical toxic stress and spermatic DNA damage. In conclusion, the current study demonstrated that Nano-Se may be useful to prevent CIS-induced gonadotoxicity through its antioxidant potential.
Collapse
Affiliation(s)
- Mohammad Amin Rezvanfar
- Department of Toxicology and Pharmacology, Faculty of Pharmacy, and Pharmaceutical Sciences Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | | | | | | | | | | | | |
Collapse
|
63
|
Brigelius-Flohé R, Kipp AP. Physiological functions of GPx2 and its role in inflammation-triggered carcinogenesis. Ann N Y Acad Sci 2012; 1259:19-25. [PMID: 22758632 DOI: 10.1111/j.1749-6632.2012.06574.x] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Mammalian glutathione peroxidases (GPxs) are reviewed with emphasis on the role of the gastrointestinal GPx2 in tumorigenesis. GPx2 ranks high in the hierarchy of selenoproteins, corroborating its importance. Colocalization of GPx2 with the Wnt pathway in crypt bases of the intestine and its induction by Wnt signals point to a role in mucosal homeostasis, but GPx2 might also support tumor growth when increased by a dysregulated Wnt pathway. In contrast, the induction of GPx2 by Nrf2 activators and the upregulation of COX2 in cells with a GPx2 knockdown reveal inhibition of inflammation and suggest prevention of inflammation-mediated carcinogenesis. The Janus-faced role of GPx2 has been confirmed in a mouse model of inflammation-associated colon carcinogenesis (AOM/DSS), where GPx2 deletion increased inflammation and consequently tumor development, but decreased tumor size. The model further revealed a GPx2-independent decrease in tumor development by selenium (Se) and detrimental effects of the Nrf2-activator sulforaphane in moderate Se deficiency.
Collapse
Affiliation(s)
- Regina Brigelius-Flohé
- Biochemistry of Micronutrients Department, German Institute of Human Nutrition, Potsdam-Rehbruecke, Germany
| | | |
Collapse
|
64
|
Disruption of the selenocysteine lyase-mediated selenium recycling pathway leads to metabolic syndrome in mice. Mol Cell Biol 2012; 32:4141-54. [PMID: 22890841 DOI: 10.1128/mcb.00293-12] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Selenium (Se) is an essential trace element used for biosynthesis of selenoproteins and is acquired either through diet or cellular recycling mechanisms. Selenocysteine lyase (Scly) is the enzyme that supplies Se for selenoprotein biosynthesis via decomposition of the amino acid selenocysteine (Sec). Knockout (KO) of Scly in a mouse affected hepatic glucose and lipid homeostasis. Mice lacking Scly and raised on an Se-adequate diet exhibit hyperinsulinemia, hyperleptinemia, glucose intolerance, and hepatic steatosis, with increased hepatic oxidative stress, but maintain selenoprotein levels and circulating Se status. Insulin challenge of Scly KO mice results in attenuated Akt phosphorylation but does not decrease phosphorylation levels of AMP kinase alpha (AMPKα). Upon dietary Se restriction, Scly KO animals develop several characteristics of metabolic syndrome, such as obesity, fatty liver, and hypercholesterolemia, with aggravated hyperleptinemia, hyperinsulinemia, and glucose intolerance. Hepatic glutathione peroxidase 1 (GPx1) and selenoprotein S (SelS) production and circulating selenoprotein P (Sepp1) levels are significantly diminished. Scly disruption increases the levels of insulin-signaling inhibitor PTP1B. Our results suggest a dependence of glucose and lipid homeostasis on Scly activity. These findings connect Se and energy metabolism and demonstrate for the first time a unique physiological role of Scly in an animal model.
Collapse
|
65
|
Clément C, Witschi U, Kreuzer M. The potential influence of plant-based feed supplements on sperm quantity and quality in livestock: A review. Anim Reprod Sci 2012; 132:1-10. [DOI: 10.1016/j.anireprosci.2012.04.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2011] [Revised: 03/26/2012] [Accepted: 04/02/2012] [Indexed: 01/16/2023]
|
66
|
Erkekoglu P, Zeybek ND, Giray B, Asan E, Hincal F. The effects of di(2-ethylhexyl)phthalate exposure and selenium nutrition on sertoli cell vimentin structure and germ-cell apoptosis in rat testis. ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2012; 62:539-547. [PMID: 22002783 DOI: 10.1007/s00244-011-9712-9] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2011] [Accepted: 09/22/2011] [Indexed: 05/31/2023]
Abstract
This study aimed to investigate the effects of di(2-ethylhexyl)phthalate (DEHP) on Sertoli-cell vimentin filaments and germ-cell apoptosis in testes of pubertal rats at different selenium (Se) status. Se deficiency was produced in 3-weeks old Sprague-Dawley rats by feeding them ≤ 0.05 Se mg/kg diet for 5 weeks, Se supplementation group was on 1 mg Se/kg diet, and DEHP was applied at 1000 mg/kg dose by gavage during the last 10 days of the feeding period. The diet with excess Se did not cause any appreciable alteration in vimentin staining and apoptosis of germ cells, but Se deficiency caused a mild decrease in the intensity of vimentin immunoreactivity and enhanced germ-cell apoptosis significantly (approximately 3-fold, p <0.0033). DEHP exposure caused disruption and collapse of vimentin filaments and significantly induced apoptotic death of germ cells (approximately 8-fold, p <0.0033). In DEHP-exposed Se-deficient animals, compared with the control, collapse of vimentin filaments was more prominent; there was serious damage to the seminiferous epithelium; and a high increment (approximately 25-fold, p <0.0033) in apoptotic germ cells was observed. Thus, Se deficiency exacerbated the toxicity of DEHP on Sertoli cells and spermatogenesis, whereas Se supplementation provided protection. These results put forward the critical role of Se in the modulation of redox status of testicular cells and emphasize the importance of Se status for reproductive health.
Collapse
Affiliation(s)
- Pinar Erkekoglu
- Faculty of Pharmacy, Department of Toxicology, Hacettepe University, 06100 Ankara, Turkey
| | | | | | | | | |
Collapse
|
67
|
Grim JM, Hyndman KA, Kriska T, Girotti AW, Crockett EL. Relationship between oxidizable fatty acid content and level of antioxidant glutathione peroxidases in marine fish. ACTA ACUST UNITED AC 2012; 214:3751-9. [PMID: 22031739 DOI: 10.1242/jeb.058214] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Biological membranes can be protected from lipid peroxidation by antioxidant enzymes including catalase (CAT) and selenium-dependent glutathione peroxidases 1 and 4 (GPx1 and GPx4). Unlike GPx1, GPx4 can directly detoxify lipid hydroperoxides in membranes without prior action of phospholipase A(2). We hypothesized that (1) GPx4 is enhanced in species that contain elevated levels of highly oxidizable polyunsaturated fatty acids (PUFA) and (2) activities of antioxidant enzymes are prioritized to meet species-specific oxidative stresses. In this study we examined (i) activities of the oxidative enzyme citrate synthase (CS) and antioxidant (CAT, GPx1 and GPx4) enzymes, (ii) GPx4 protein expression, and (iii) phospholipid composition in livers of five species of marine fish (Myxine glutinosa, Petromyzon marinus, Squalus acanthias, Fundulus heteroclitus and Myoxocephalus octodecemspinosus) that contain a range of PUFA. GPx4 activity was, on average, 5.8 times higher in F. heteroclitus and S. acanthias than in the other three marine fish species sampled. Similarly, activities of CAT and GPx1 were highest in S. acanthias and F. heteroclitus, respectively. GPx4 activity for all species correlates with membrane unsaturation, as well as oxidative activity as indicated by CS. These data support our hypothesis that GPx4 level in marine fish is a function, at least in part, of high PUFA content in these animals. GPx1 activity was also correlated with membrane unsaturation, indicating that marine species partition resources among glutathione-dependent defenses for protection from the initial oxidative insult (e.g. H(2)O(2)) and to repair damaged lipids within biological membranes.
Collapse
Affiliation(s)
- Jeffrey M Grim
- Ohio University, Department of Biological Sciences, Athens, OH 45701, USA.
| | | | | | | | | |
Collapse
|
68
|
Malinouski M, Kehr S, Finney L, Vogt S, Carlson BA, Seravalli J, Jin R, Handy DE, Park TJ, Loscalzo J, Hatfield DL, Gladyshev VN. High-resolution imaging of selenium in kidneys: a localized selenium pool associated with glutathione peroxidase 3. Antioxid Redox Signal 2012; 16:185-92. [PMID: 21854231 PMCID: PMC3234661 DOI: 10.1089/ars.2011.3997] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2011] [Revised: 08/19/2011] [Accepted: 08/19/2011] [Indexed: 10/17/2022]
Abstract
AIM Recent advances in quantitative methods and sensitive imaging techniques of trace elements provide opportunities to uncover and explain their biological roles. In particular, the distribution of selenium in tissues and cells under both physiological and pathological conditions remains unknown. In this work, we applied high-resolution synchrotron X-ray fluorescence microscopy (XFM) to map selenium distribution in mouse liver and kidney. RESULTS Liver showed a uniform selenium distribution that was dependent on selenocysteine tRNA([Ser]Sec) and dietary selenium. In contrast, kidney selenium had both uniformly distributed and highly localized components, the latter visualized as thin circular structures surrounding proximal tubules. Other parts of the kidney, such as glomeruli and distal tubules, only manifested the uniformly distributed selenium pattern that co-localized with sulfur. We found that proximal tubule selenium localized to the basement membrane. It was preserved in Selenoprotein P knockout mice, but was completely eliminated in glutathione peroxidase 3 (GPx3) knockout mice, indicating that this selenium represented GPx3. We further imaged kidneys of another model organism, the naked mole rat, which showed a diminished uniformly distributed selenium pool, but preserved the circular proximal tubule signal. INNOVATION We applied XFM to image selenium in mammalian tissues and identified a highly localized pool of this trace element at the basement membrane of kidneys that was associated with GPx3. CONCLUSION XFM allowed us to define and explain the tissue topography of selenium in mammalian kidneys at submicron resolution.
Collapse
Affiliation(s)
- Mikalai Malinouski
- Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massaachusetts
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, Nebraska
| | - Sebastian Kehr
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, Nebraska
| | - Lydia Finney
- X-ray Science Division, Argonne National Laboratory, Argonne, Illinois
- Biosciences Division, Argonne National Laboratory, Argonne, Illinois
| | - Stefan Vogt
- X-ray Science Division, Argonne National Laboratory, Argonne, Illinois
| | - Bradley A. Carlson
- Molecular Biology of Selenium Section, Laboratory of Cancer Prevention, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland
| | - Javier Seravalli
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, Nebraska
| | - Richard Jin
- Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massaachusetts
| | - Diane E. Handy
- Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massaachusetts
| | - Thomas J. Park
- Department of Biological Sciences, University of Illinois, Chicago, Illinois
| | - Joseph Loscalzo
- Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massaachusetts
| | - Dolph L. Hatfield
- Molecular Biology of Selenium Section, Laboratory of Cancer Prevention, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland
| | - Vadim N. Gladyshev
- Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massaachusetts
| |
Collapse
|
69
|
Selenium and its' role in the maintenance of genomic stability. Mutat Res 2012; 733:100-10. [PMID: 22234051 DOI: 10.1016/j.mrfmmm.2011.12.011] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2011] [Revised: 12/11/2011] [Accepted: 12/22/2011] [Indexed: 02/07/2023]
Abstract
Selenium (Se) is an essential micronutrient for humans, acting as a component of the unusual amino acids, selenocysteine (Se-Cys) and selenomethionine (Se-Met). Where Se levels are low, the cell cannot synthesise selenoproteins, although some selenoproteins and some tissues are prioritised over others. Characterised functions of known selenoproteins, include selenium transport (selenoprotein P), antioxidant/redox properties (glutathione peroxidases (GPxs), thioredoxin reductases and selenoprotein P) and anti-inflammatory properties (selenoprotein S and GPx4). Various forms of Se are consumed as part of a normal diet, or as a dietary supplement. Supplementation of tissue culture media, animal or human diets with moderate levels of certain Se compounds may protect against the formation of DNA adducts, DNA or chromosome breakage, and chromosome gain or loss. Protective effects have also been shown on mitochondrial DNA, and on telomere length and function. Some of the effects of Se compounds on gene expression may relate to modulation of DNA methylation or inhibition of histone deacetylation. Despite a large number of positive effects of selenium and selenoproteins in various model systems, there have now been some human clinical trials that have shown adverse effects of Se supplementation, according to various endpoints. Too much Se is as harmful as too little, with animal models showing a "U"-shaped efficacy curve. Current recommended daily allowances differ among countries, but are generally based on the amount of Se necessary to saturate GPx enzymes. However, increasing evidence suggests that other enzymes may be more important than GPx for Se action, that optimal levels may depend upon the form of Se being ingested, and vary according to genotype. New paradigms, possibly involving nutrigenomic tools, will be necessary to optimise the forms and levels of Se desirable for maximum protection of genomic stability in all humans.
Collapse
|
70
|
Mistry HD, Broughton Pipkin F, Redman CWG, Poston L. Selenium in reproductive health. Am J Obstet Gynecol 2012; 206:21-30. [PMID: 21963101 DOI: 10.1016/j.ajog.2011.07.034] [Citation(s) in RCA: 175] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2011] [Revised: 07/12/2011] [Accepted: 07/22/2011] [Indexed: 02/07/2023]
Abstract
Selenium is an essential trace element of importance to human biology and health. Increasing evidence suggests that this mineral plays an important role in normal growth and reproduction in animals and humans, and selenium supplementation is now recommended as part of public health policy in geographical areas with severe selenium deficiency in soil. This review addresses the biological functions of selenium followed by a detailed review of associations between selenium status and reproductive health. In many countries, selenium dietary intake falls below the recommended nutrient intakes and is inadequate to support maximal expression of the selenoenzymes. Numerous reports implicate selenium deficiency in several reproductive and obstetric complications including male and female infertility, miscarriage, preeclampsia, fetal growth restriction, preterm labor, gestational diabetes, and obstetric cholestasis. Currently, there is inadequate information from the available small intervention studies to inform public health strategies. Larger intervention trials are required to reinforce or refute a beneficial role of selenium supplementation in disorders of reproductive health.
Collapse
Affiliation(s)
- Hiten D Mistry
- Maternal and Fetal Research Unit, Division of Women's Health, King's College London, United Kingdom.
| | | | | | | |
Collapse
|
71
|
Brigelius-Flohé R, Flohé L. Basic principles and emerging concepts in the redox control of transcription factors. Antioxid Redox Signal 2011; 15:2335-81. [PMID: 21194351 PMCID: PMC3166203 DOI: 10.1089/ars.2010.3534] [Citation(s) in RCA: 416] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Convincing concepts of redox control of gene transcription have been worked out for prokaryotes and lower eukaryotes, whereas the knowledge on complex mammalian systems still resembles a patchwork of poorly connected findings. The article, therefore, reviews principles of redox regulation with special emphasis on chemical feasibility, kinetic requirements, specificity, and physiological context, taking well investigated mammalian transcription factor systems, nuclear transcription factor of bone marrow-derived lymphocytes (NF-κB), and kelch-like ECH-associated protein-1 (Keap1)/Nrf2, as paradigms. Major conclusions are that (i) direct signaling by free radicals is restricted to O(2)•- and •NO and can be excluded for fast reacting radicals such as •OH, •OR, or Cl•; (ii) oxidant signals are H(2)O(2), enzymatically generated lipid hydroperoxides, and peroxynitrite; (iii) free radical damage is sensed via generation of Michael acceptors; (iv) protein thiol oxidation/alkylation is the prominent mechanism to modulate function; (v) redox sensors must be thiol peroxidases by themselves or proteins with similarly reactive cysteine or selenocysteine (Sec) residues to kinetically compete with glutathione peroxidase (GPx)- and peroxiredoxin (Prx)-type peroxidases or glutathione-S-transferases, respectively, a postulate that still has to be verified for putative mammalian sensors. S-transferases and Prxs are considered for system complementation. The impact of NF-κB and Nrf2 on hormesis, management of inflammatory diseases, and cancer prevention is critically discussed.
Collapse
Affiliation(s)
- Regina Brigelius-Flohé
- Department Biochemistry of Micronutrients, German Institute of Human Nutrition Potsdam-Rehbruecke, Arthur-Scheunert-Allee 114-116, Nuthetal, Germany.
| | | |
Collapse
|
72
|
Hoefig CS, Renko K, Köhrle J, Birringer M, Schomburg L. Comparison of different selenocompounds with respect to nutritional value vs. toxicity using liver cells in culture. J Nutr Biochem 2011; 22:945-55. [DOI: 10.1016/j.jnutbio.2010.08.006] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2010] [Revised: 08/02/2010] [Accepted: 08/05/2010] [Indexed: 10/18/2022]
|
73
|
Lee KH, Shim MS, Kim JY, Jung HK, Lee E, Carlson BA, Xu XM, Park JM, Hatfield DL, Park T, Lee BJ. Drosophila selenophosphate synthetase 1 regulates vitamin B6 metabolism: prediction and confirmation. BMC Genomics 2011; 12:426. [PMID: 21864351 PMCID: PMC3218224 DOI: 10.1186/1471-2164-12-426] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2011] [Accepted: 08/24/2011] [Indexed: 11/10/2022] Open
Abstract
Background There are two selenophosphate synthetases (SPSs) in higher eukaryotes, SPS1 and SPS2. Of these two isotypes, only SPS2 catalyzes selenophosphate synthesis. Although SPS1 does not contain selenophosphate synthesis activity, it was found to be essential for cell growth and embryogenesis in Drosophila. The function of SPS1, however, has not been elucidated. Results Differentially expressed genes in Drosophila SL2 cells were identified using two-way analysis of variance methods and clustered according to their temporal expression pattern. Gene ontology analysis was performed against differentially expressed genes and gene ontology terms related to vitamin B6 biosynthesis were found to be significantly affected at the early stage at which megamitochondria were not formed (day 3) after SPS1 knockdown. Interestingly, genes related to defense and amino acid metabolism were affected at a later stage (day 5) following knockdown. Levels of pyridoxal phosphate, an active form of vitamin B6, were decreased by SPS1 knockdown. Treatment of SL2 cells with an inhibitor of pyridoxal phosphate synthesis resulted in both a similar pattern of expression as that found by SPS1 knockdown and the formation of megamitochondria, the major phenotypic change observed by SPS1 knockdown. Conclusions These results indicate that SPS1 regulates vitamin B6 synthesis, which in turn impacts various cellular systems such as amino acid metabolism, defense and other important metabolic activities.
Collapse
Affiliation(s)
- Kwang Hee Lee
- Department of Biological Sciences, Seoul National University, Seoul 151-742, Korea
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
74
|
Abstract
Thiol peroxidases comprise glutathione peroxidases (GPx) and peroxiredoxins (Prx). The enzymes of both families reduce hydroperoxides with thiols by enzyme-substitution mechanisms. H(2)O(2) and organic hydroperoxides are reduced by all thiol peroxidases, most efficiently by SecGPxs, whereas fast peroxynitrite reduction is more common in Prxs. Reduction of lipid hydroperoxides is the domain of monomeric GPx4-type enzymes and of some Prxs. The catalysis starts with oxidation of an active-site selenocysteine (U(P)) or cysteine (C(P)). Activation of Cys (Sec) for hydroperoxide reduction in the GPx family is achieved by a typical tetrad composed of Cys (Sec), Asn, Gln, and Trp, whereas a triad of Cys Thr (or Ser) and Arg is the signature of Prx. In many of the CysGPxs and Prxs, a second Cys (C(R)) is required. In these 2-CysGPxs and 2-CysPrxs, the C(P) oxidized to a sulfenic acid forms an intra- or intermolecular disulfide (typical 2-CysPrx) with C(R), before a stepwise regeneration of ground-state enzyme by redoxin-type proteins can proceed. In SecGPxs and sporadically in Prxs, GSH is used as the reductant. Diversity combined with structural variability predestines thiol peroxidases for redox regulation via ROOH sensing and direct or indirect transduction of oxidant signals to specific protein targets.
Collapse
Affiliation(s)
- Leopold Flohé
- Otto-von-Guericke-Universität and MOLISA GmbH, Magdeburg, Germany.
| | | | | | | |
Collapse
|
75
|
Erkekoglu P, Zeybek ND, Giray B, Asan E, Arnaud J, Hincal F. Reproductive toxicity of di(2-ethylhexyl) phthalate in selenium-supplemented and selenium-deficient rats. Drug Chem Toxicol 2011; 34:379-89. [DOI: 10.3109/01480545.2010.547499] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
76
|
Fujii J, Ito JI, Zhang X, Kurahashi T. Unveiling the roles of the glutathione redox system in vivo by analyzing genetically modified mice. J Clin Biochem Nutr 2011; 49:70-8. [PMID: 21980221 PMCID: PMC3171681 DOI: 10.3164/jcbn.10-138sr] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2010] [Accepted: 12/31/2010] [Indexed: 12/19/2022] Open
Abstract
Redox status affects various cellular activities, such as proliferation, differentiation, and death. Recent studies suggest pivotal roles of reactive oxygen species not only in pathogenesis under oxidative insult but also in intracellular signal transduction. Glutathione is present in several millimolar concentrations in the cytoplasm and has multiple roles in the regulation of cellular homeostasis. Two enzymes, γ-glutamylcysteine synthetase and glutathione synthetase, constitute the de novo synthesis machinery, while glutathione reductase is involved in the recycling of oxidized glutathione. Multidrug resistant proteins and some other transporters are responsible for exporting oxidized glutathione, glutathione conjugates, and S-nitrosoglutathione. In addition to antioxidation, glutathione is more positively involved in cellular activity via its sulfhydryl moiety of a molecule. Animals in which genes responsible for glutathione metabolism are genetically modified can be used as beneficial and reliable models to elucidate roles of glutathione in vivo. This review article overviews recent progress in works related to genetically modified rodents and advances in the elucidation of glutathione-mediated reactions.
Collapse
Affiliation(s)
- Junichi Fujii
- Department of Biochemistry and Molecular Biology, Graduate School of Medical Science, Yamagata University, 2-2-2 Iidanishi, Yamagata 990-9585, Japan
| | | | | | | |
Collapse
|
77
|
Ferguson LR, Karunasinghe N. Nutrigenetics, nutrigenomics, and selenium. Front Genet 2011; 2:15. [PMID: 22303312 PMCID: PMC3268570 DOI: 10.3389/fgene.2011.00015] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2011] [Accepted: 03/21/2011] [Indexed: 01/01/2023] Open
Abstract
Selenium (Se) is an important micronutrient that, as a component of selenoproteins, influences oxidative and inflammatory processes. Its’ levels vary considerably, with different ethnic and geographic population groups showing varied conditions, ranging from frank Se deficiencies to toxic effects. An optimum Se level is essential for the maintenance of homeostasis, and this optimum may vary according to life stage, general state of health, and genotype. Nutrigenetic studies of different Se levels, in the presence of genetic variants in selenoproteins, suggest that an effective dietary Se intake for one individual may be very different from that for others. However, we are just starting to learn the significance of various genes in selenoprotein pathways, functional variants in these, and how to combine such data from genes into pathways, alongside dietary intake or serum levels of Se. Advances in systems biology, genetics, and genomics technologies, including genetic/genomic, epigenetic/epigenomic, transcriptomic, proteomic, and metabolomic information, start to make it feasible to assess a comprehensive spectrum of the biological activity of Se. Such nutrigenomic approaches may prove very sensitive biomarkers of optimal Se status at the individual or population level. The premature cessation of a major human Se intervention trial has led to considerable controversy as to the value of Se supplementation at the population level. New websites provide convenient links to current information on methodologies available for nutrigenetics and nutrigenomics. These new technologies will increasingly become an essential tool in optimizing the level of Se and other micronutrients for optimal health, in individuals and in population groups. However, definitive proof of such effects will require very large collaborative studies, international agreement on study design, and innovative approaches to data analysis.
Collapse
Affiliation(s)
- Lynnette R Ferguson
- Discipline of Nutrition, Faculty of Medical and Health Sciences, The University of Auckland Auckland, New Zealand
| | | |
Collapse
|
78
|
Kulinskiĭ VI, Kolesnichenko LS. [Nuclear glutathione and its functions]. BIOMEDIT︠S︡INSKAI︠A︡ KHIMII︠A︡ 2011; 56:657-62. [PMID: 21395068 DOI: 10.18097/pbmc20105606657] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
During recent years the nuclear localization of glutathione has been confirmed and this fraction has been quantitatively determined. The nuclear GSH and the enzymes of its metabolism realize independent and important functions. They considerably differ from functions of hyaloplasmic and mitochondrial GSH. Glutathione interacts with regulatory pathways, involved into signal transmission into the nucleus.
Collapse
|
79
|
Patora-Komisarska K, Jadwiga Podwysocka D, Seebach D. Preparation of the β2-Homoselenocysteine Derivatives Fmoc-(S)-β2hSec(PMB)-OH and Boc-(S)-β2hSec(PMB)-OH for Solution and Solid-Phase Peptide Synthesis. Helv Chim Acta 2011. [DOI: 10.1002/hlca.201000409] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
80
|
|
81
|
Schoenmakers E, Agostini M, Mitchell C, Schoenmakers N, Papp L, Rajanayagam O, Padidela R, Ceron-Gutierrez L, Doffinger R, Prevosto C, Luan J, Montano S, Lu J, Castanet M, Clemons N, Groeneveld M, Castets P, Karbaschi M, Aitken S, Dixon A, Williams J, Campi I, Blount M, Burton H, Muntoni F, O'Donovan D, Dean A, Warren A, Brierley C, Baguley D, Guicheney P, Fitzgerald R, Coles A, Gaston H, Todd P, Holmgren A, Khanna KK, Cooke M, Semple R, Halsall D, Wareham N, Schwabe J, Grasso L, Beck-Peccoz P, Ogunko A, Dattani M, Gurnell M, Chatterjee K. Mutations in the selenocysteine insertion sequence-binding protein 2 gene lead to a multisystem selenoprotein deficiency disorder in humans. J Clin Invest 2010; 120:4220-35. [PMID: 21084748 DOI: 10.1172/jci43653] [Citation(s) in RCA: 196] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2010] [Accepted: 09/29/2010] [Indexed: 02/02/2023] Open
Abstract
Selenium, a trace element that is fundamental to human health, is incorporated into some proteins as selenocysteine (Sec), generating a family of selenoproteins. Sec incorporation is mediated by a multiprotein complex that includes Sec insertion sequence-binding protein 2 (SECISBP2; also known as SBP2). Here, we describe subjects with compound heterozygous defects in the SECISBP2 gene. These individuals have reduced synthesis of most of the 25 known human selenoproteins, resulting in a complex phenotype. Azoospermia, with failure of the latter stages of spermatogenesis, was associated with a lack of testis-enriched selenoproteins. An axial muscular dystrophy was also present, with features similar to myopathies caused by mutations in selenoprotein N (SEPN1). Cutaneous deficiencies of antioxidant selenoenzymes, increased cellular ROS, and susceptibility to ultraviolet radiation-induced oxidative damage may mediate the observed photosensitivity. Reduced levels of selenoproteins in peripheral blood cells were associated with impaired T lymphocyte proliferation, abnormal mononuclear cell cytokine secretion, and telomere shortening. Paradoxically, raised ROS in affected subjects was associated with enhanced systemic and cellular insulin sensitivity, similar to findings in mice lacking the antioxidant selenoenzyme glutathione peroxidase 1 (GPx1). Thus, mutation of SECISBP2 is associated with a multisystem disorder with defective biosynthesis of many selenoproteins, highlighting their role in diverse biological processes.
Collapse
Affiliation(s)
- Erik Schoenmakers
- Institute of Metabolic Science, University of Cambridge, Cambridge, UK
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
82
|
Kulinsky VI, Kolesnichenko LS. The nuclear glutathione and its functions. BIOCHEMISTRY MOSCOW-SUPPLEMENT SERIES B-BIOMEDICAL CHEMISTRY 2010. [DOI: 10.1134/s1990750810030029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
83
|
Messaoudi I, Banni M, Saïd L, Saïd K, Kerkeni A. Involvement of selenoprotein P and GPx4 gene expression in cadmium-induced testicular pathophysiology in rat. Chem Biol Interact 2010; 188:94-101. [PMID: 20643113 DOI: 10.1016/j.cbi.2010.07.012] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2010] [Revised: 07/06/2010] [Accepted: 07/09/2010] [Indexed: 01/14/2023]
Abstract
To investigate the effect of co-exposure to cadmium (Cd) and selenium (Se) on selenoprotein P (SelP) and phospholipid hydroperoxide glutathione peroxidase (GPx4) gene expression in testis and to evaluate their possible involvement in Cd-induced testicular pathophysiology, male rats received either tap water, Cd or Cd+Se in their drinking water for 5 weeks. Cd exposure caused a down-regulation of SelP and GPx4 gene expression and a significant decrease in plasma and testicular concentrations of Se. These changes were accompanied by decreased plasma testosterone level, sperm count and motility, GSH content, protein-bound sulfhydryl concentration (PSH), enzymatic activities of catalase (CAT) and glutathione peroxidase (GSH-Px) as well as by increased glutathione-S-transferase (GST) activity, lipid peroxidation (as malondialdehyde, MDA) and proteins carbonyls (PC). The decrease of testicular SelP and GPx4 gene expression under Cd influence was significantly restored in Cd+Se group. Co-treatment with Cd and Se also totally reversed the Cd-induced depletion of Se, decrease in plasma testosterone level and partially restored Cd-induced oxidative stress and decrease in sperm count and motility. Taken together, these data suggest that down-regulation of SelP and GPx4 gene expression induces plasma and testicular Se depletion leading, at least in part, to Cd-induced testicular pathophysiology.
Collapse
Affiliation(s)
- Imed Messaoudi
- UR 09/30: Génétique, Biodiversité et Valorisation des Bioressources, Institut de Biotechnologie, 5000 Monastir, Tunisia. imed
| | | | | | | | | |
Collapse
|
84
|
Kim JY, Lee KH, Shim MS, Shin H, Xu XM, Carlson BA, Hatfield DL, Lee BJ. Human selenophosphate synthetase 1 has five splice variants with unique interactions, subcellular localizations and expression patterns. Biochem Biophys Res Commun 2010; 397:53-8. [PMID: 20471958 DOI: 10.1016/j.bbrc.2010.05.055] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2010] [Accepted: 05/08/2010] [Indexed: 10/19/2022]
Abstract
Selenophosphate synthetase 1 (SPS1) is an essential cellular gene in higher eukaryotes. Five alternative splice variants of human SPS1 (major type, DeltaE2, DeltaE8, +E9, +E9a) were identified wherein +E9 and +E9a make the same protein. The major type was localized in both the nuclear and plasma membranes, and the others in the cytoplasm. All variants form homodimers, and in addition, the major type forms a heterodimer with DeltaE2, and DeltaE8 with +E9. The level of expression of each splice variant was different in various cell lines. The expression of each alternative splice variant was regulated during the cell cycle. The levels of the major type and DeltaE8 were gradually increased until G2/M phase and then gradually decreased. DeltaE2 expression peaked at mid-S phase and then gradually decreased. However, +E9/+E9a expression decreased gradually after cell cycle arrest. The possible involvement of SPS1 splice variants in cell cycle regulation is discussed.
Collapse
Affiliation(s)
- Jin Young Kim
- Laboratory of Molecular Genetics and Genomics, School of Biological Sciences, Institute of Molecular Biology and Genetics, Seoul National University, Seoul 151-742, Republic of Korea
| | | | | | | | | | | | | | | |
Collapse
|
85
|
Conrad M, Schweizer U. Unveiling the molecular mechanisms behind selenium-related diseases through knockout mouse studies. Antioxid Redox Signal 2010; 12:851-65. [PMID: 19803749 DOI: 10.1089/ars.2009.2912] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Selenium (Se), in the form of the 21st amino acid selenocysteine, is an integral part of selenoproteins and essential for mammals. While a large number of health claims for Se has been proposed in a diverse set of diseases, little is known about the precise molecular mechanisms and the physiological roles of selenoproteins. With the recent and rigorous application of reverse genetics in the mouse, great strides have been made to address this on a more molecular level. In this review, we focus on results obtained from the application of mouse molecular genetics in mouse physiology and discuss these insights into the physiological actions of selenoproteins in light of evidence from human genetics.
Collapse
Affiliation(s)
- Marcus Conrad
- Institute of Clinical Molecular Biology and Tumor Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Marchioninistrasse 25, Munich, Germany.
| | | |
Collapse
|
86
|
Preventive Effects of Intraperitoneal Selenium on Cerebral Vasospasm In Experimental Subarachnoid Hemorrhage. J Neurosurg Anesthesiol 2010; 22:53-8. [DOI: 10.1097/ana.0b013e3181b26a63] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
87
|
Shim MS, Kim JY, Jung HK, Lee KH, Xu XM, Carlson BA, Kim KW, Kim IY, Hatfield DL, Lee BJ. Elevation of glutamine level by selenophosphate synthetase 1 knockdown induces megamitochondrial formation in Drosophila cells. J Biol Chem 2009; 284:32881-94. [PMID: 19755423 PMCID: PMC2781704 DOI: 10.1074/jbc.m109.026492] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2009] [Revised: 09/11/2009] [Indexed: 11/06/2022] Open
Abstract
Although selenophosphate synthetase 1 (SPS1/SelD) is an essential gene in Drosophila, its function has not been determined. To elucidate its intracellular role, we targeted the removal of SPS1/SelD mRNA in Drosophila SL2 cells using RNA interference technology that led to the formation of vacuole-like globular structures. Surprisingly, these structures were identified as megamitochondria, and only depolarized mitochondria developed into megamitochondria. The mRNA levels of l(2)01810 and glutamine synthetase 1 (GS1) were increased by SPS1/SelD knockdown. Blocking the expression of GS1 and l(2)01810 completely inhibited the formation of megamitochondria induced by loss of SPS1/SelD activity and decreased the intracellular levels of glutamine to those of control cells suggesting that the elevated level of glutamine is responsible for megamitochondrial formation. Overexpression of GS1 and l(2)01810 had a synergistic effect on the induction of megamitochondrial formation and on the synthesis of glutamine suggesting that l(2)01810 is involved in glutamine synthesis presumably by activating GS1. Our results indicate that, in Drosophila, SPS1/SelD regulates the intracellular glutamine by inhibiting GS1 and l(2)01810 expression and that elevated levels of glutamine lead to a nutritional stress that provides a signal for megamitochondrial formation.
Collapse
Affiliation(s)
- Myoung Sup Shim
- From the
Laboratory of Molecular Genetics and Genomics, School of Biological Sciences, Institute of Molecular Biology and Genetics, Seoul National University, Seoul 151-742, Korea
| | - Jin Young Kim
- From the
Laboratory of Molecular Genetics and Genomics, School of Biological Sciences, Institute of Molecular Biology and Genetics, Seoul National University, Seoul 151-742, Korea
| | - Hee Kyoung Jung
- From the
Laboratory of Molecular Genetics and Genomics, School of Biological Sciences, Institute of Molecular Biology and Genetics, Seoul National University, Seoul 151-742, Korea
| | - Kwang Hee Lee
- From the
Laboratory of Molecular Genetics and Genomics, School of Biological Sciences, Institute of Molecular Biology and Genetics, Seoul National University, Seoul 151-742, Korea
| | - Xue-Ming Xu
- Laboratory of Cancer Prevention, Center for Cancer Research, NCI, National Institutes of Health, Bethesda, Maryland 20892
| | - Bradley A. Carlson
- Laboratory of Cancer Prevention, Center for Cancer Research, NCI, National Institutes of Health, Bethesda, Maryland 20892
| | - Ki Woo Kim
- National Instrumentation Center for Environmental Management, College of Agriculture and Life Science, Seoul National University, Seoul 151-742, Korea, and
| | - Ick Young Kim
- Laboratory of Cellular and Molecular Biochemistry, School of Life Sciences and Biotechnology, Korea University, Seoul 136-701, Korea
| | - Dolph L. Hatfield
- Laboratory of Cancer Prevention, Center for Cancer Research, NCI, National Institutes of Health, Bethesda, Maryland 20892
| | - Byeong Jae Lee
- From the
Laboratory of Molecular Genetics and Genomics, School of Biological Sciences, Institute of Molecular Biology and Genetics, Seoul National University, Seoul 151-742, Korea
| |
Collapse
|
88
|
|
89
|
Imai H, Hakkaku N, Iwamoto R, Suzuki J, Suzuki T, Tajima Y, Konishi K, Minami S, Ichinose S, Ishizaka K, Shioda S, Arata S, Nishimura M, Naito S, Nakagawa Y. Depletion of selenoprotein GPx4 in spermatocytes causes male infertility in mice. J Biol Chem 2009; 284:32522-32. [PMID: 19783653 DOI: 10.1074/jbc.m109.016139] [Citation(s) in RCA: 145] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Phospholipid hydroperoxide glutathione peroxidase (GPx4) is an intracellular antioxidant enzyme that directly reduces peroxidized phospholipids. GPx4 is strongly expressed in the mitochondria of testis and spermatozoa. We previously found a significant decrease in the expression of GPx4 in spermatozoa from 30% of infertile human males diagnosed with oligoasthenozoospermia (Imai, H., Suzuki, K., Ishizaka, K., Ichinose, S., Oshima, H., Okayasu, I., Emoto, K., Umeda, M., and Nakagawa, Y. (2001) Biol. Reprod. 64, 674-683). To clarify whether defective GPx4 in spermatocytes causes male infertility, we established spermatocyte-specific GPx4 knock-out mice using a Cre-loxP system. All the spermatocyte-specific GPx4 knock-out male mice were found to be infertile despite normal plug formation after mating and displayed a significant decrease in the number of spermatozoa. Isolated epididymal GPx4-null spermatozoa could not fertilize oocytes in vitro. These spermatozoa showed significant reductions of forward motility and the mitochondrial membrane potential. These impairments were accompanied by the structural abnormality, such as a hairpin-like flagella bend at the midpiece and swelling of mitochondria in the spermatozoa. These results demonstrate that the depletion of GPx4 in spermatocytes causes severe abnormalities in spermatozoa. This may be one of the causes of male infertility in mice and humans.
Collapse
Affiliation(s)
- Hirotaka Imai
- School of Pharmaceutical Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
90
|
Liang H, Yoo SE, Na R, Walter CA, Richardson A, Ran Q. Short form glutathione peroxidase 4 is the essential isoform required for survival and somatic mitochondrial functions. J Biol Chem 2009; 284:30836-44. [PMID: 19744930 DOI: 10.1074/jbc.m109.032839] [Citation(s) in RCA: 116] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Glutathione peroxidase 4 (Gpx4) is an essential antioxidant enzyme having multiple functions. A long form Gpx4 protein and a short form Gpx4 protein, which are distinguishable by the presence or lack of a mitochondrial signal peptide at the N terminus, are generated from the Gpx4 gene. In this study, we generated transgenic mice using mutated GPX4 genes encoding either the long form Gpx4 (lGPX4 gene) or the short form Gpx4 (sGPX4 gene). Our results showed that transgenic mice with the sGPX4 gene had increased Gpx4 protein in all tissues and were protected against diquat-induced apoptosis in liver. Moreover, the sGPX4 gene was able to rescue the lethal phenotype of the mouse Gpx4-null mutation. In contrast, transgenic mice with the lGPX4 gene had increased Gpx4 protein only in the testes, and the lGPX4 gene failed to rescue the lethal phenotype of the mouse Gpx4-null mutation. In Gpx4-null mice rescued by the sGPX4 gene, the Gpx4 protein was present in mitochondria isolated from somatic tissues, and the submitochondrial distribution pattern of the Gpx4 protein in these mice was identical to that in wild-type mice. Interestingly, the male Gpx4-null mice rescued by the sGPX4 gene were infertile and exhibited sperm malformation. Together, our results demonstrated for the first time that the short form Gpx4 protein is present in somatic tissue mitochondria and is essential for survival and protection against apoptosis in mice, whereas the long form Gpx4 protein is important for male fertility.
Collapse
Affiliation(s)
- Hanyu Liang
- Sam and Ann Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center, San Antonio, Texas 78229, USA
| | | | | | | | | | | |
Collapse
|
91
|
Reeves MA, Hoffmann PR. The human selenoproteome: recent insights into functions and regulation. Cell Mol Life Sci 2009; 66:2457-78. [PMID: 19399585 PMCID: PMC2866081 DOI: 10.1007/s00018-009-0032-4] [Citation(s) in RCA: 354] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2009] [Revised: 04/01/2009] [Accepted: 04/03/2009] [Indexed: 12/16/2022]
Abstract
Selenium (Se) is a nutritional trace mineral essential for various aspects of human health that exerts its effects mainly through its incorporation into selenoproteins as the amino acid, selenocysteine. Twenty-five selenoprotein genes have been identified in humans and several selenoproteins are broadly classified as antioxidant enzymes. As progress is made on characterizing the individual members of this protein family, however, it is becoming clear that their properties and functions are quite diverse. This review summarizes recent insights into properties of individual selenoproteins such as tissue distribution, subcellular localization, and regulation of expression. Also discussed are potential roles the different selenoproteins play in human health and disease.
Collapse
Affiliation(s)
- M. A. Reeves
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii, 651 Ilalo Street, Honolulu, HI 96813 USA
| | - P. R. Hoffmann
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii, 651 Ilalo Street, Honolulu, HI 96813 USA
| |
Collapse
|
92
|
Zhang Y, Gladyshev VN. Comparative Genomics of Trace Elements: Emerging Dynamic View of Trace Element Utilization and Function. Chem Rev 2009; 109:4828-61. [DOI: 10.1021/cr800557s] [Citation(s) in RCA: 99] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Yan Zhang
- Department of Biochemistry and Redox Biology Center, University of Nebraska, Lincoln, Nebraska 68588-0664
| | - Vadim N. Gladyshev
- Department of Biochemistry and Redox Biology Center, University of Nebraska, Lincoln, Nebraska 68588-0664
| |
Collapse
|
93
|
Abstract
Yeast two-hybrid screening of mouse cDNA libraries was performed to identify proteins interacting with selenocysteine lyase (SCL), which decomposes L-selenocysteine. Several proteins related to spermatogenesis, protein synthesis, and cell viability/apoptosis were identified as potential interactors. Major urinary proteins 1 and 2 interacted with SCL and inhibited its activity. Coimmunoprecipitation revealed interactions between SCL and each of two selenophosphate synthetase isozymes.
Collapse
|
94
|
Toppo S, Flohé L, Ursini F, Vanin S, Maiorino M. Catalytic mechanisms and specificities of glutathione peroxidases: variations of a basic scheme. Biochim Biophys Acta Gen Subj 2009; 1790:1486-500. [PMID: 19376195 DOI: 10.1016/j.bbagen.2009.04.007] [Citation(s) in RCA: 276] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2009] [Revised: 03/29/2009] [Accepted: 04/03/2009] [Indexed: 01/18/2023]
Abstract
Kinetics and molecular mechanisms of GPx-type enzymes are reviewed with emphasis on structural features relevant to efficiency and specificity. In Sec-GPxs the reaction takes place at a single redox centre with selenocysteine as redox-active residue (peroxidatic Sec, U(P)). In contrast, most of the non-vertebrate GPx have the U(P) replaced by a cysteine (peroxidatic Cys, C(P)) and work with a second redox centre that contains a resolving cysteine (C(R)). While the former type of enzymes is more or less specific for GSH, the latter are reduced by "redoxins". The common denominator of the GPx family is the first redox centre comprising the (seleno)cysteine, tryptophan, asparagine and glutamine. In this architectural context the rate of hydroperoxide reduction by U(P) or C(P), respectively, is enhanced by several orders of magnitude compared to that of free selenolate or thiolate. Mammalian GPx-1 dominates H(2)O(2) metabolism, whereas the domain of GPx-4 is the reduction of lipid hydroperoxides with important consequences such as counteracting 12/15-lipoxygenase-induced apoptosis and regulation of inflammatory responses. Beyond, the degenerate GSH specificity of GPx-4 allows selenylation and oxidation to disulfides of protein thiols. Heterodimer formation of yeast GPx with a transcription factor is discussed as paradigm of a redox sensing that might also be valid in vertebrates.
Collapse
Affiliation(s)
- Stefano Toppo
- Department of Biological Chemistry, Viale G. Colombo, 3, University of Padova, I-35121 Padova, Italy
| | | | | | | | | |
Collapse
|
95
|
Schomburg L, Schweizer U. Hierarchical regulation of selenoprotein expression and sex-specific effects of selenium. Biochim Biophys Acta Gen Subj 2009; 1790:1453-62. [PMID: 19328222 DOI: 10.1016/j.bbagen.2009.03.015] [Citation(s) in RCA: 176] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2009] [Revised: 03/17/2009] [Accepted: 03/18/2009] [Indexed: 02/07/2023]
Abstract
The expression of selenoproteins is controlled on each one of the textbook steps of protein biosynthesis, i.e., during gene transcription, RNA processing, translation and posttranslational events as well as via control of the stability of the involved intermediates and final products. Selenoproteins are unique in their dependence on the trace element Se which they incorporate as the 21st proteinogenic amino acid, selenocysteine. Higher mammals have developed unique pathways to enable a fine-tuned expression of all their different selenoproteins according to developmental stage, actual needs, and current availability of the trace element. Tightly controlled and dynamic expression patterns of selenoproteins are present in different tissues. Interestingly, these patterns display some differences in male and female individuals, and can be grossly modified during disease, e.g. in cancer, inflammation or neurodegeneration. Likewise, important health issues related to the selenium status show unexpected sexual dimorphisms. Some detailed molecular insights have recently been gained on how the hierarchical Se distribution among the different tissues is achieved, how the selenoprotein biosynthesis machinery discriminates among the individual selenoprotein transcripts and how impaired selenoprotein biosynthesis machinery becomes phenotypically evident in humans. This review tries to summarize these fascinating findings and highlights some interesting and surprising sex-specific differences.
Collapse
Affiliation(s)
- Lutz Schomburg
- Institute for Experimental Endocrinology, Südring 10, CVK, Charité - Universitätsmedizin Berlin, 13353-Berlin, Germany.
| | | |
Collapse
|
96
|
Guo CH, Hsu GSW, Chuang CJ, Chen PC. Aluminum accumulation induced testicular oxidative stress and altered selenium metabolism in mice. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2009; 27:176-181. [PMID: 21783936 DOI: 10.1016/j.etap.2008.10.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2008] [Revised: 09/29/2008] [Accepted: 10/04/2008] [Indexed: 05/31/2023]
Abstract
Present work was carried out to investigate how testicular selenium (Se) metabolisms respond to oxidative stress induced by aluminum (Al). Mice were intraperitoneally exposed to 0, 7, or 35mg Al/kg/d for 14 days (CNL, LAL and HAL groups). Al administration significantly increased Al, reactive oxygen radical and malondialdehyde (MDA) levels, as well as decreased glutathione peroxidase (GPx) and glutathione reductase (GR) activities in serum and testes. The serum concentrations of Se were remarkably lower at LAL and HAL groups compared to the controls, whereas the testicular Se levels significantly reduced only in the HAL group. In addition, RT-PCR analysis revealed an increased testicular selenoprotein P (SelP) expression by Al treatment. Western blot analysis showed increased levels of SelP protein expression in the LAL group, but the expression levels were significantly reduced in HAL group. It was suggested that altered metabolism of Se, further stimulated testicular SelP transcription that may compensate for the loss of SelP protein resulted from Al-induced oxidative damage.
Collapse
Affiliation(s)
- Chih-Hung Guo
- Institute of Biomedical Nutrition, Hung Kuang University, Taichung 433, Taiwan, ROC
| | | | | | | |
Collapse
|
97
|
Ramamoorthi RV, Rossano MG, Paneth N, Gardiner JC, Diamond MP, Puscheck E, Daly DC, Potter RC, Wirth JJ. An application of multivariate ranks to assess effects from combining factors: metal exposures and semen analysis outcomes. Stat Med 2008; 27:3503-14. [PMID: 18314933 DOI: 10.1002/sim.3236] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
In studies of environmental effects on human health outcomes, it is often difficult to assess the effects of a group of exposure variables when the individual exposures do not appear to have statistically significant effects. To address this situation, we propose a method of U-scores applied to subsets of multivariate data. We illustrate the usefulness of this approach by applying it to data collected as part of a study on the effects of metal exposure on human semen parameters. In this analysis, profiles (pairs) of metals containing copper and/or manganese were negatively correlated with total motile sperm and profiles containing copper were negatively correlated with sperm morphology; profiles containing selenium and chromium were positively correlated with total motile sperm.
Collapse
Affiliation(s)
- R V Ramamoorthi
- Department of Statistics and Probability, Michigan State University, East Lansing, MI 48824, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
98
|
Banning A, Kipp A, Schmitmeier S, Löwinger M, Florian S, Krehl S, Thalmann S, Thierbach R, Steinberg P, Brigelius-Flohé R. Glutathione Peroxidase 2 Inhibits Cyclooxygenase-2–Mediated Migration and Invasion of HT-29 Adenocarcinoma Cells but Supports Their Growth as Tumors in Nude Mice. Cancer Res 2008; 68:9746-53. [DOI: 10.1158/0008-5472.can-08-1321] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
99
|
Shepherd AA. Nutrition through the life-span. Part 1: preconception, pregnancy and infancy. ACTA ACUST UNITED AC 2008; 17:1261-8. [DOI: 10.12968/bjon.2008.17.20.31638] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
100
|
Abstract
Peroxidase research has been instrumental in defining the principles of chemical catalysis. By now, enzymes termed peroxidases represent a heterogeneous group of distinct enzyme families that operate by different catalytic principles and fulfill diverse biological functions, detoxifying H2O2 being just one of many aspects. H2O2 -dependent synthesis of secondary metabolites is the domain of heme peroxidases and related enzymes operating by transition metal catalysis, that often is mediated by free radical formation. Instead, the coenzyme-free glutathione peroxidases and peroxiredoxins only catalyze two-electron transitions and, thus, can reliably remove hydroperoxides without causing radical-mediated collateral damage. However, their ability to use hydroperoxides for the formation of specific disulfide bonds with and within particular proteins broadens their spectrum of biological activities to differentiation phenomena, redox regulation of metabolic processes, redox sensing, and signalling. The present Forum Editorial tries to guide the reader through the 190 years of equally bewildering and fascinating research on peroxidases up to the topical frontiers of the field that are addressed in this issue.
Collapse
Affiliation(s)
| | - Fulvio Ursini
- Department of Biological Chemistry, University of Padova, Padova, Italy
| |
Collapse
|