Dietary Selenium Stabilizes Glutathione Peroxidase mRNA in Rat Liver

Christensen, Merrill J.; Burgener, K. W.

doi:10.1093/jn/122.8.1620

Cited by 101 publications

(43 citation statements)

References 28 publications

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“…In the present study, Se-deficient GPX1 mRNA levels were 10 to 15% of Se-adequate levels, similar to previous reports. 14,16,17 This 85 to 90% decrease in GPX1 mRNA level was observed using Northern blot analysis for samples with equal amounts of total RNA and by slot-blot analysis for samples with equal amounts of mRNA. Dietary Se status had no effect on poly A mRNA levels or on β-actin mRNA levels, further demonstrating that the mechanism for Se regulation of GPX1 mRNA is specific.…”

Section: Discussionmentioning

confidence: 81%

“…In rats fed a Sedeficient diet, liver GPX1 mRNA levels decrease exponentially to approximately 10% of Se-adequate levels. 2,6,[14][15][16][17] Several studies have shown that GPX1 transcription is not affected by Se status, [17][18][19] indicating that Se status must regulate GPX1 mRNA stability. We have recently demonstrated that the GPX1 3' untranslated region (3'UTR) is necessary for GPX1 mRNA levels to decrease in Se-deficient cells, 20 suggesting that the GPX1 3'UTR may contain an Se-responsive element.…”

Section: Introductionmentioning

confidence: 99%

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Dietary selenium regulation of glutathione peroxidase mRNA and other selenium-dependent parameters in male rats

Weiss

Evenson

Thompson

et al. 1997

The Journal of Nutritional Biochemistry

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Weanling male rats were fed a basal torula yeast diet (0.007 μg Se/g diet) supplemented with graded levels of Se (0 to 0.2 μg Se/g diet as Na 2 SeO 3 ) (three rats/group) to evaluate classical glutathione peroxidase (GPX1, GSH:H 2 O 2 , oxidoreductase, EC 1.11.1.9) mRNA level as an indicator of intracellular Se status. Growth was followed throughout the dietary treatment and a number of Se-dependent parameters including liver GPX1 mRNA levels were determined after 33 days. Growth was not impaired at any level of dietary Se supplementation. In rats fed the Sedeficient basal diet, liver Se concentration was 5 ± 1%, liver GPXI mRNA levels were 10 ± 2%. plasma GPX activity was 2 ± 1%, erythrocyte GPX activity was 37 ± 1%, and liver GPX activity was 0 ± 2% of the levels in rats fed 0.1 μg Se/g diet; these parameters increased sigmoidally with increasing dietary Se, showing a breakpoint near 0.1 μg Se/g diet. Graphical analysis indicated that the increase in liver GPX1 mRNA level with increasing dietary Se, preceded the increase in liver GPX activity. Se supplementation had no effect on polyadenylated mRNA levels or on β-actin mRNA levels, demonstrating that Se regulation of GPX1 mRNA is specific. Se-deficient liver selenoprotein P mRNA levels were 69 ± 2% of the levels in rats fed 0.1 μg Se/g diet. We hypothesize that GPX1 mRNA is a primary target of the Se regulatory mechanism, making GPX1 mRNA level a potentially useful indicator of the status of an important intracellular regulatory pool of Se.

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Section: Discussionmentioning

confidence: 81%

Section: Introductionmentioning

confidence: 99%

Dietary selenium regulation of glutathione peroxidase mRNA and other selenium-dependent parameters in male rats

Weiss

Evenson

Thompson

et al. 1997

The Journal of Nutritional Biochemistry

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“…Some elevation may arise from increased transcription since for all selenazolidines except 2-methylSCA, the magnitude of the increase was significantly diminished in the presence of actinomycin D. That some elevation was still evident would suggest that additional mechanisms are operating, however, possibly mRNA stabilization. Such a mechanism has been implicated in maintaining hepatic glutathione peroxidase mRNA levels in a selenium-sufficient as compared to a selenium-deficient diet in rats (Christensen and Burgener, 1992). The elevation seen in the Ugt1a6 transcript with cycloheximide present provides evidence of additional unusual features in the regulation of this gene; in this case, the possibility of the presence of an inhibitory transcription factor.…”

Section: Discussionmentioning

confidence: 88%

Murine hepatoma (Hepa1c1c7) cells: A responsive in vitro system for chemoprotective enzyme induction by organoselenium compounds

El‐Sayed

Aboul‐Fadl

Roberts

et al. 2007

Toxicology in Vitro

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Murine (Hepa1c1c7) hepatoma cells are a suitable in vitro system for investigating the regulation of chemoprotective enzymes by selenazolidines, novel L-selenocysteine prodrugs developed as potential chemopreventive agents. They are less sensitive to the cytotoxic effects of both selenite and the less toxic selenazolidines than rat hepatoma (H4IIE) cells. All four selenazolidine 4-carboxylic acid (SCA) derivatives examined elevated thioredoxin reductase (Txnrd1), alpha-class glutathione transferases (Gsta), and UDP-glucuronosyltransferase (Ugt)1a6 mRNAs. NAD(P)Hquinone oxidoreductase (Nqo1) was induced by the three 2-alkyl derivatives (2-cyclohexylSCA, 2-butylSCA, and 2-methylSCA) but not SCA itself. Transcripts of mu-and pi-class glutathione transferases were induced only by 2-cyclohexylSCA and 2-butylSCA. Only Gsta and Txnrd1 transcripts were elevated by L-selenomethionine, L-selenocystine, or Se-methyl-L-selenocysteine. Txnrd1, Gsta, Nqo1, and Gstp responses to selenazolidines were all abolished by actinomycin D while Ugt1a6 responses were not. Induction responses to the selenazolidines were also eliminated (most) or reduced (Txnrd1 by 2-methylSCA) by cycloheximide, with the exception of Ugt1a6. The Ugt1a6 mRNA levels in the presence of SCAs and cycloheximide were similar to those with cycloheximide alone, and were almost double those of vehicle-treated cells. Thus, Hepa1c1c7 cells appear to provide a viable platform for the study of protective enzyme regulation by selenocompounds, and with the exception of Ugt1a6, the mRNA elevations from selenazolidines are transcriptionally dependent.

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“…Gene expression and translational efficiency are upregulated by selenium. 41 Dietary selenium stabilizes GPx mRNA 42 and the 3Ј untranslated region of the GPx gene plays an important role in GPx gene expression. 43 Enzyme activity of GPx is also upregulated by selenium in human cell lines.…”

Section: Effect Of Genistein On Antioxidant Enzymes Activities In Lncmentioning

confidence: 99%

Genistein, a soy isoflavone, induces glutathione peroxidase in the human prostate cancer cell lines LNCaP and PC‐3

Suzuki

Koike

Matsui

et al. 2002

Intl Journal of Cancer

170

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Genistein is a major component of soybean isoflavone and has multiple functions resulting in antitumor effects. Prostate cancer is 1 of the targets for the preventive role of genistein. We examined the effect of genistein on human prostate cancer (LNCaP and PC-3) cells. Proliferation of both cell lines was inhibited by genistein treatment in a dose-dependent manner. To obtain the gene expression profile of genistein in LNCaP cells, we performed cDNA microarray analysis. The expression of many genes, including apoptosis inhibitor (survivin), DNA topoisomerase II, cell division cycle 6 (CDC6) and mitogen-activated protein kinase 6 (MAPK 6), was downregulated. Expression levels were increased more than 2-fold in only 4 genes. The glutathione peroxidase (GPx)-1 gene expression level was the most upregulated. Quantitative real-time polymerase chain reaction revealed significant elevation of transcript levels of GPx-1 in both LNCaP and PC-3 cells. Upregulation of gene expression levels accompanied elevation of GPx enzyme activities. In contrast, no significant changes were observed in the gene expression levels and enzyme activities of the other antioxidant enzymes, superoxide dismutase and catalase. GPx activation might be one of the important characteristics of the effects of genistein on prostate cancer cells.

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Dietary Selenium Stabilizes Glutathione Peroxidase mRNA in Rat Liver

Cited by 101 publications

References 28 publications

Dietary selenium regulation of glutathione peroxidase mRNA and other selenium-dependent parameters in male rats

Dietary selenium regulation of glutathione peroxidase mRNA and other selenium-dependent parameters in male rats

Murine hepatoma (Hepa1c1c7) cells: A responsive in vitro system for chemoprotective enzyme induction by organoselenium compounds

Genistein, a soy isoflavone, induces glutathione peroxidase in the human prostate cancer cell lines LNCaP and PC‐3

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