scholarly journals Tissue-specific regulation of selenoenzyme gene expression during selenium deficiency in rats

1995 ◽  
Vol 311 (2) ◽  
pp. 425-430 ◽  
Author(s):  
G Bermano ◽  
F Nicol ◽  
J A Dyer ◽  
R A Sunde ◽  
G J Beckett ◽  
...  
Keyword(s):  
Glutathione Peroxidase ◽  
Transcriptional Control ◽  
Selenium Deficiency ◽  
Mrna Levels ◽  
Phospholipid Hydroperoxide Glutathione Peroxidase ◽  
Tissue Specific ◽  
Run Off ◽  
Cytosolic Glutathione ◽  
Se Deficiency ◽  
Specific Regulation

Regulation of synthesis of the selenoenzymes cytosolic glutathione peroxidase (GSH-Px), phospholipid hydroperoxide glutathione peroxidase (PHGSH-Px) and type-1 iodothyronine 5′-deiodinase (5′IDI) was investigated in liver, thyroid and heart of rats fed on diets containing 0.405, 0.104 (Se-adequate), 0.052, 0.024 or 0.003 mg of Se/kg. Severe Se deficiency (0.003 mg of Se/kg) caused almost total loss of GSH-Px activity and mRNA in liver and heart. 5′IDI activity decreased by 95% in liver and its mRNA by 50%; in the thyroid, activity increased by 15% and mRNA by 95%. PHGSH-Px activity was reduced by 75% in the liver and 60% in the heart but mRNA levels were unchanged; in the thyroid, PHGSH-Px activity was unaffected by Se depletion but its mRNA increased by 52%. Thus there is differential regulation of the three mRNAs and subsequent protein synthesis within and between organs, suggesting both that mechanisms exist to channel Se for synthesis of a particular enzyme and that there is tissue-specific regulation of selenoenzyme mRNAs. During Se depletion, the levels of selenoenzyme mRNA did not necessarily parallel the changes in enzyme activity, suggesting a distinct mechanism for regulating mRNA levels. Nuclear run-off assays with isolated liver nuclei showed severe Se deficiency to have no effect on transcription of the three genes, suggesting that there is post-transcriptional control of the three selenoenzymes, probably involving regulation of mRNA stability.

scholarly journals Role of the 3′ untranslated region in the regulation of cytosolic glutathione peroxidase and phospholipid-hydroperoxide glutathione peroxidase gene expression by selenium supply

1996 ◽  
Vol 320 (3) ◽  
pp. 891-895 ◽  
Author(s):  
Giovanna BERMANO ◽  
John R. ARTHUR ◽  
John E. HESKETH
Keyword(s):  
Gene Expression ◽  
Glutathione Peroxidase ◽  
Selenium Deficiency ◽  
Type I ◽  
Mrna Levels ◽  
Phospholipid Hydroperoxide Glutathione Peroxidase ◽  
Iodothyronine Deiodinase ◽  
Phospholipid Hydroperoxide ◽  
Cytosolic Glutathione

Selenium is an essential nutrient and synthesis of selenoproteins is affected by limited selenium supply. During selenium deficiency there is a differential regulation of selenoprotein synthesis and gene expression; for example, there is a decrease in abundance of mRNA for cytosolic glutathione peroxidase (cGSH-Px) and a preservation of mRNA for phospholipid-hydroperoxide glutathione peroxidase (PHGSH-Px). This difference is not due to an alteration in the rate of transcription but might reflect differences in translation. The aim of the present work was to assess the role of cGSH-Px and PHGSH-Px 3´ untranslated regions (UTRs) in the regulation of selenoprotein mRNA stability and translation by using H4-II-E-C3 cells transfected with different constructs containing a type I iodothyronine deiodinase-coding region linked to different selenoprotein mRNA 3´ UTRs. Translational efficiency results showed that the efficiency of the 3´ UTRs in permitting selenocysteine incorporation is similar in selenium-replete conditions but, when selenium is limiting, the 3´ UTR of cGSH-Px is less efficient than the 3´ UTR of PHGSH-Px. The results suggest that the 3´ UTR of these selenoprotein mRNA species influences their extent of translation when selenium levels are low. The different sensitivity of the 3´ UTRs to selenium deficiency can explain the differential effect that selenium deficiency has on cGSH-Px and PHGSH-Px activity and mRNA levels, stability and translation. This might be partly responsible for channelling selenium for synthesis of PHGSH-Px rather than cGSH-Px.

scholarly journals Effects of Dietary Selenium Deficiency or Excess on Selenoprotein Gene Expression in the Spleen Tissue of Pigs

Animals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1122 ◽  
Author(s):  
Zhuang Lu ◽  
Pengzu Wang ◽  
Teng Teng ◽  
Baoming Shi ◽  
Anshan Shan ◽  
...  
Keyword(s):  
Glutathione Peroxidase ◽  
Thioredoxin Reductase ◽  
Selenium Deficiency ◽  
Type I ◽  
Mrna Levels ◽  
Spleen Tissue ◽  
Selenoprotein K ◽  
Selenoprotein Genes ◽  
Se Deficiency ◽  
Selenoprotein M

To evaluate the effects of dietary Se deficiency and excess on the mRNA levels of selenoproteins in pig spleen tissues, 20 healthy uncastrated boars (Duroc × Landrace × Yorkshire, 10 ± 0.72 kg) were randomly divided into four groups (5 pigs per group). The pigs were fed a Se deficient corn-soybean basal feed (Se content <0.03 mg/kg) or basal feed with added sodium selenite at 0.3, 1.0, or 3.0 mg Se/kg diet, respectively. The experiment lasted 16 weeks. The spleen tissue was collected to examine the mRNA expression levels of 24 selenoprotein genes at the end of the study. Compared with pigs in other groups, those fed with the 1.0 mg Se/kg diet had higher mRNA levels of glutathione peroxidase 1 (Gpx1), glutathione peroxidase 2 (Gpx2), deiodinase type II (Dio2), thioredoxin reductase 3 (Txnrd3), selenoprotein H (Selh), selenoprotein N, 1 (Sepn1), selenoprotein P1 (Sepp1), and selenoprotein V (Selv) in the spleen (p < 0.05). Dietary Se deficiency resulted in lower mRNA levels of Gpx1, Gpx2, glutathione peroxidase 3 (Gpx3), Dio2, thioredoxin reductase 2 (Txnrd2), Txnrd3, Selh, selenoprotein I (Seli), selenoprotein K (Selk), selenoprotein M (Selm), Sepn1, Sepp1, and Selv in the spleen than the other three groups. Dietary Se levels did not affect the mRNA levels of glutathione peroxidase 4 (Gpx4), deiodinase type I (Dio1), deiodinase type III (Dio3), selenophosphate synthetase 2 (Sephs2), thioredoxin reductase 1 (Txnrd1), selenoprotein O (Selo), selenoprotein S (Sels), selenoprotein W (Selw), selenoprotein X (Selx), and selenoprotein 15 (Sel15) in the spleen (p > 0.05). Dietary Se levels can affect the transcription levels of 14 selenoprotein genes in the spleen of pigs.

Liver-specific RNA metabolism in hepatoma cells: variations in transcription rates and mRNA levels

1985 ◽  
Vol 5 (10) ◽  
pp. 2633-2641
Author(s):  
D F Clayton ◽  
M Weiss ◽  
J E Darnell
Keyword(s):  
Cell Lines ◽  
Transcriptional Control ◽  
Hepatoma Cell ◽  
Primary Cultures ◽  
Normal Liver ◽  
Liver Cells ◽  
Hepatoma Cell Line ◽  
Mrna Levels ◽  
Tissue Specific ◽  
Specific Mrnas

The transcription rate and abundance of several liver-specific mRNAs as well as mRNAs common to many cell types were compared in a series of rodent hepatoma cell lines, normal liver cells, and primary hepatocyte cultures. The rat hepatoma cell line, Fao, which displays a liver-specific phenotype, contained eight of eight liver-specific mRNAs examined. However, the transcription rates of most liver-specific mRNAs were found to be low (1 to 30%) compared with normal liver in this and other differentiated cell lines. This low rate is similar to the transcription rates of liver-specific mRNA sequences measured in primary cultures of hepatocytes. Several variant cell lines that had lost differentiated traits contained few or none of the liver-specific mRNAs; clonal descendents which had regained differentiated function regained the tissue-specific mRNAs as a group, but at various concentrations. Because all of the changes observed in mRNA levels were not accompanied by parallel changes in transcription of the same sequences, differential posttranscriptional stabilization of the liver-specific mRNAs must also occur in the different cell lines. These results qualify the utility of cultured cell lines in the study of tissue-specific transcriptional control, but raise the possibility that posttranscriptional mechanisms act in cooperation with transcriptional controls to bring the level of tissue-specific mRNAs closer to those found in liver cells.

Tissue-Specific Regulation of Basic Fibroblast Growth Factor mRNA Levels by Diabetes

Diabetes ◽  
1992 ◽  
Vol 41 (2) ◽  
pp. 222-226 ◽  
Author(s):  
C. W. Karpen ◽  
R. G. Spanheimer ◽  
A. L. Randolph ◽  
W. L. Lowe
Keyword(s):  
Growth Factor ◽  
Fibroblast Growth Factor ◽  
Basic Fibroblast Growth Factor ◽  
Mrna Levels ◽  
Fibroblast Growth ◽  
Tissue Specific ◽  
Specific Regulation

scholarly journals Tissue-specific regulation of the expression of rat kallikrein gene family members by thyroid hormone

1990 ◽  
Vol 267 (3) ◽  
pp. 745-750 ◽  
Author(s):  
J A Clements ◽  
B A Matheson ◽  
J E Funder
Keyword(s):  
Gene Family ◽  
Hormonal Regulation ◽  
Female Rats ◽  
Hormonal Status ◽  
Mrna Levels ◽  
Specific Expression ◽  
Male And Female ◽  
Tissue Specific ◽  
Male And Female Rats ◽  
Specific Regulation

We have altered the thyroid hormonal status of both male and female rats and examined the expression of six functional members of the rat kallikrein gene family (PS, S1, S2, S3, K1 and P1) in the submandibular gland (SMG), kidney, prostate, testis and anterior pituitary gland (AP) of these animals. On Northern-blot analysis with gene-specific oligonucleotide probes, the steady-state mRNA levels of S1, S2, S3, K1 and P1 were all dramatically altered in the SMG of male and female rats treated with propylthiouracil (PTU; 100 mg/litre of drinking water) or thyroxine (T4; 10 micrograms/100 mg body wt.) for 3 weeks. The SMG mRNA levels of these five genes were all lowered (30-90%) in hypothyroid (PTU-treated) male and female rats and elevated (1.4-4-fold, male; 1.5-11-fold, female) in the hyperthyroid (T4-treated) and PTU/T4-treated animals. In contrast, PS (true kallikrein) mRNA levels in the male or female SMG or kidney were essentially unchanged. K1 mRNA levels in the kidney were considerably less responsive to thyroid status than those in the SMG. Changes in S3 and P1 mRNA levels in the prostate were also variable, but essentially unaffected by these treatments. AP PS mRNA levels were also unaffected by changes in thyroid-hormonal status, as were levels of a novel P1-like mRNA in the testis. In summary, these studies demonstrate that the same kallikrein gene family member(s) may be differentially regulated by thyroid hormones in the rat SMG, kidney, prostate and pituitary, and thus further extend the concept of tissue-specific expression and hormonal regulation of the kallikrein gene family in the rat.

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