• BMB Reports
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• v.42 no.10
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• pp.648-654
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• 2009

Overexpression of phospholipid hydroperoxide glutathione peroxidase (PHGPx) genes has been reported to play an important role in protecting host cells from oxidative injury in several model systems. A radish phospholipid hydroperoxide glutathione peroxidase (RsPHGPx) known to have high catalytic activity was applied to mouse 3T3 fibroblasts to determine the protective effects of PHGPx against oxidative injury triggered by hydroperoxides such as hydrogen peroxide ($H_2O_2$), tert-butyl hydroperoxide (t-BHP) and phosphatidylcholine hydroperoxide (PCOOH). We observed that preincubation of cells with RsPHGPx significantly increased cell viability, reduced levels of malondialdehyde (MDA), inhibited generation of reactive oxygen species (ROS), and maintained natural cell shapes after treatment with $H_2O_2$, t-BHP or PCOOH, indicating that the exogenous RsPHGPx can act as an effective hydroperoxide-scavenger and may also protect target cells from oxidative damage. These results suggest the possibility for use of RsPHGPx as a therapeutic protectant.

• Proceedings of the Korean Society of Toxicology Conference
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• 2001.05a
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• pp.161-161
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• 2001

Phospholipid hydroperoxide glutathione peroxidase (PHGPx) is an antioxidant selenoenzyme which interacts directly with and diminishes peroxidized phospholipids, cholesterol and cholesteryl ester in tissues. PHGPx activity appears in most tissues, but is especially high in testis. In testis, PHGPx level decreases in hypophysectomized rats but is partially restored after gonadotropin treament.(omitted)

• Preventive Nutrition and Food Science
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• v.8 no.1
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• pp.36-39
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• 2003

Many defined cell culture media were formulated over 3() years ago and may be deficient in certain micronutrients whose essentiality has only subsequently been recognised. The objective of this study was to evaluate whether alpha-minimal essential medium (MEM) supplemented with 10% foetal bovine serum contained sufficient selenium for optimal activity of the selenium containing enzymes cytosolic glutathione peroxidase (cGPx) and phospholipid hydroperoxide glutathione peroxidase (PHGPx) in cultured Chinese hamster ovary (CHO) cells. Additionally, the effect of zinc deficiency and metallothionein (MT) overexpression on cGPx and PHGPx activity was studied. The addition of 100 nM of selenous acid to the culture medium increased cGPx expression by 10-fold and PHGPx by about 2-fold in both wild-type CHO-K1 cells and CHO-K1 cells overexpressing mouse MT-1. Zinc deficiency had no significant effect on enzyme activity, but cells overexpressing mouse MT-1 had higher levels of cGPx activity. Zinc deficiency decreased cell survival but overexpression of MT-1 was partially protective, probably because its presence in quantity favoured the uptake, sequestration and cellular retention of any remaining zinc. This study demonstrates that selenium in complete alpha-MEM is insufficient for optimal cGPx and PHGPx activity and may compromise the cellular response to oxidative stress.

• BMB Reports
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• v.40 no.3
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• pp.412-418
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• 2007

Phospholipid hydroperoxide glutathione peroxidase (PHGPx) is an unique antioxidant enzyme that directly reduces lipid hydroperoxides in biomembranes. In the present work, the entire encoding region for Oryza sativa PHGPx was expressed in Escherichia coli M15, and the purified fusion protein showed a single band with 21.0 kD and pI = 8.5 on SDS- and IFE-PAGE, respectively. Judging from CD and fluorescence spectroscopy, this protein is considered to have a well-ordered structure with 12.2% $\alpha$-helix, 30.7%$\beta$-sheet, 18.5% $\delta$-turn, and 38.5% random coil. The optimum pH and temperature of the enzyme activity were pH 9.3 and 27$^{\circ}C$. The enzyme exhibited the highest affinity and catalytical efficiency to phospholipid hydroperoxide employing GSH or Trx as electron donor. Moreover, the protein displayed higher GSH-dependent activity towards t-Butyl-OOH and $H_2O_2$. These results show that OsPHGPx is an enzyme with broad specificity for hydroperoxide substrates and yielded significant insight into the physicochemical properties and the dynamics of OsPHGPx.

• Proceedings of the Korean Society of Toxicology Conference
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• 2001.05a
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• pp.163-163
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• 2001

Selenium (Se) is an essential micronutrient for mammals and its biological functions are mediated by selenoprotein. In tissues, Se is incorporated into the selenoprotein by recognition of the UGA codon as a stop codon for selenoprotein. Phospholipid hydroperoxide glutathione peroxidase (PHGPx) is an antioxidant selenoprotein that belongs to the superfamily of selenium-dependent peroxidase.(omitted)

• Proceedings of the Korean Society of Toxicology Conference
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• 2001.05a
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• pp.164-164
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• 2001

This study investigated expression pattern of PHGPx gene in male rat reproductive organs exposed to 17$\beta$-estradiol. First, in view of quantitative change, the exposure to 17$\beta$-estradiol for 1 week increased PHGPx mRNA level in testis and prostate. PHGPx mRNA level in epididymis decreased weakly as compared to control group.(omitted)

• Development and Reproduction
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• v.14 no.2
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• pp.99-105
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• 2010

The seminiferous epithelium, with its division into 12 spermatogenic stages in the mouse, is a very complex tissue. Glutathione peroxidase (GPx) is a representative antioxidant enzyme that is capable of reducing organic hydroperoxides to their corresponding hydroxyl compounds utilizing glutathione and is related to the mammalian spermatogenesis. In this study, a real-time PCR was performed in the stage-specific seminiferous tubules of mouse testes excised by a laser capture microdissection (LCM) in order to quantitate the expression levels of a series of GPx genes including cytosolic GPx (cGPx), gastrointestinal GPx (GI-GPx), plasma GPx (pGPx), and phospholipid hydroperoxide GPx (PHGPx). Frozen sections (10 ${\mu}m$) were obtained from normal adult mouse testes. LCM was used to capture all the cells that were grouped into stages I-V, VII-VIII, and IX-XI in cross-sections of seminiferous tubules. The expression level of PHGPx mRNA was remarkably higher than those of other GPx mRNAs in mouse testes. During spermatogenesis, the expressions of GI-GPx, pGPx, and PHGPx mRNAs were highest on stages VII-VIII, began to decrease after stage XI, and showed a lowest level on stage I-V. However, the expressions of cGPx mRNA were highest on stages VII-VIII, and showed a lowest level on stage XI-XI. These findings indicate that GPx genes are expressed differentially on mouse spermatogenesis and also LCM can be an useful tool in cellular quantitative analysis of testes.

• Journal of Embryo Transfer
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• v.27 no.2
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• pp.101-105
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• 2012

Linuron is a pesticide with a weak anti-androgenic property, which impacts male reproductive organs. In this study, to clarify whether linuron affects the cellular antioxidant system of ventral prostate, gene expression patterns of the representative antioxidant enzymes such as glutathione peroxidase (GPx), selenoprotein P (SePP), and superoxide dismutase (SOD) were investigated in the rat ventral prostates exposed to linuron using real-time RT-PCR analyses. Sprague-Dawley rats castrated at 6 weeks old were treated with linuron (25, 50, or 100 mg/kg per oral) daily for 10 days after testosterone propionate administration (0.4 mg/kg) subcutaneously. As compared to normal control animals, mRNA levels of phospholipid hydroperoxide GPx (PHGPx), SePP, and Mn SOD significantly increased in the prostates exposed to linuron (25, 50, and 100 mg/kg). However, cytosolic GPx (100 mg/kg) and Cu/Zn SOD (25, 50, and 100 mg/kg) mRNA levels significantly decreased in the ventral prostates. These results indicate that linuron upregulates the expressions of PHGPx, SePP, and Mn SOD mRNAs, but down-regulates the expressions of cytosolic GPx and Cu/Zn SOD in rat prostates, suggesting that linuron may have dual effects in the cellular antioxidant system of prostate.

• Korean Journal of Veterinary Research
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• v.59 no.2
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• pp.59-67
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• 2019

We investigated whether ${\beta}$-carotene (${\beta}-CA$) or ellagic acid (EA), originating from various fruits and vegetables, has a preventive effect against male infertility induced by exogenous scrotal hyperthermia. ICR adult mice were intraperitoneally treated with 10 mg/kg of ${\beta}-CA$ or EA daily for 13 days consecutively. During this time, mice were subjected to transient scrotal heat stress in a water bath at $43^{\circ}C$ for 20 min on day 7, and their testes and blood were obtained on day 14 for histopathologic and biochemical analyses. Heat stress induced significant testicular weight reduction, germ cell loss and degeneration, as well as abnormal localization of phospholipid hydroperoxide glutathione peroxidase (PHGPx) and manganese superoxide dismutase (MnSOD) in spermatogenic and Leydig cells. Heat stress also altered the levels of oxidative stress (lipid peroxidation, SOD activity, and PHGPx, MnSOD, and $HIF-1{\alpha}$ mRNAs), apoptosis (Bax, Bcl-xL, caspase 3, $NF-{\kappa}B$, and $TGF-{\beta}1$ mRNAs), and androgen biosynthesis (serological testosterone concentration and $3{\beta}$-hydroxysteroid dehydrogenase mRNA) in testes. These changes were all improved significantly by ${\beta}-CA$ treatment, but only slightly improved by EA treatment. These findings indicate that ${\beta}-CA$, through modulations of oxidative stress, apoptosis, and androgen biosynthesis, is a potent preventive agent against testicular injuries induced by scrotal hyperthermia.

• Journal of Embryo Transfer
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• v.26 no.4
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• pp.265-270
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• 2011

Procymidone is a fungicide with anti-androgenic properties widely used to protect fruits from fungal infection, which induces an excessive reactive oxygen species production in male reproductive organs. In this study, to clarify whether procymidone affect the cellular antioxidant system of prostate at onset of puberty, gene expression patterns of the representative antioxidant enzymes such as cytoplasmic glutathione peroxidase (GPx1), phospholipid hydroperoxide GPx (PHGPx), selenoprotein P (SePP), cytoplasmic copper/zinc superoxide dismutase (SOD1), and manganese SOD (SOD2) were investigated in the rat ventral prostates exposed to procymidone using real-time RT-PCR analyses. Seven-week-old Sprague-Dawley rats castrated at 6 weeks old were treated with procymidone (25, 50, or 100 mg/kg per day) orally for 7 consecutive days after testosterone propionate (0.4 mg/kg per day) administration by subcutaneous injection. As compared to normal control animals, GPx1 mRNA expression in prostates significantly increased by the administration with TP and/or procymidone. However, PHGPx and SOD1 mRNA levels significanatly decreased by over 25 mg/kg of procymidone treatment and SePP and SOD2 mRNA levels was significanatly reduced by over 50 mg/kg of procymidone treatment. These findings indicate that procymidone may affect the antioxidant system of prostatic cells in up-regulation mode of GPx1, but in down-regulation modes of PHGPx, SePP, SOD1, and SOD2, suggesting that procymidone may affect differently the cellular antioxidant system of prostate according to the exposure doses.