| Title |
Evidence for the involvement of the fatty acid and peroxisomal β-oxidation pathways in the inhibition by dehydroepiandrosterone (DHEA) and induction by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and benz(a)anthracene (BA) of cytochrome P4501B1 (CYP1Bl) in mouse embryo fibroblasts (C3H10T1/2 cells)
|
|---|---|
| Published in |
Molecular and Cellular Biochemistry, August 1999
|
| DOI | 10.1023/a:1006954216233 |
| Pubmed ID | |
| Authors |
Fidelis I. Ikegwuonu, Colin R. Jefcoate |
| Abstract |
Treatment of intact C3H10T1/2 cells or microsomes therefrom with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and benzanthracene (BA) enhanced CYP1B1 activity and CYP1B1 expression as revealed by elevations of CYP1B1-catalyzed DMBA metabolism, CYP1B1 apoprotein level and CYP1B1 gene expression. One hundred microM DHEA caused an 80-90% inhibition of cellular DMBA metabolism without inflicting cell death. Cytosolic glucose-6-phosphate dehydrogenase (G6PDH) was also inhibited in DHEA-treated cells, presumably due to the inhibition of NADP reduction. In contrast, neither DMBA metabolism nor CYP1B1 apoprotein was inhibited by DHEA in the microsomes isolated from these cells. DHEA (100 microM), TCDD (10 nM) and BA (10 microM) stimulated the activities and increased the apoprotein levels of two peroxisomal enzymes, namely, acyl CoA oxidase (ACOX) and acyl CoA hydrolase (ACH2) and also induced the expression of CYP1B1 and ACOX genes. Cytosolic fatty acyl-CoA beta-oxidation was also stimulated by DHEA, TCDD and BA. In corroboratory experiments, it was found that concomitant with the stimulation of the activity of a key enzyme regulator of fatty acid homeostasis, namely, glycerol-3-phosphate dehydrogenase (G3PDH), these agents enhanced arachidonic acid (AA) metabolism as judged by the release of [3H] from AA into the culture medium. Collectively, these data suggest that DHEA mediates the regulation of CYP1B1 and inhibits BA and TCDD-induced CYP1B1-catalyzed carcinogen (DMBA) activation in 10T1/2 cells through metabolic interactions that involve the activation of the peroxisomal and fatty acid beta-oxidation signaling pathways. These results also present evidence for the first time, for the possible peroxisomal effects of TCDD and BA which are similar to those of DHEA in this mouse embryo fibroblast cell line. |
Mendeley readers
The data shown below were compiled from readership statistics for 9 Mendeley readers of this research output. Click here to see the associated Mendeley record.
Geographical breakdown
| Country | Count | As % |
|---|---|---|
| Japan | 1 | 11% |
| Unknown | 8 | 89% |
Demographic breakdown
| Readers by professional status | Count | As % |
|---|---|---|
| Professor | 5 | 56% |
| Student > Ph. D. Student | 1 | 11% |
| Researcher | 1 | 11% |
| Student > Master | 1 | 11% |
| Unknown | 1 | 11% |
| Readers by discipline | Count | As % |
|---|---|---|
| Biochemistry, Genetics and Molecular Biology | 3 | 33% |
| Agricultural and Biological Sciences | 2 | 22% |
| Medicine and Dentistry | 2 | 22% |
| Unknown | 2 | 22% |
Attention Score in Context
This research output has an Altmetric Attention Score of 3. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 14 July 2018.
All research outputs
#8,535,472
of 25,374,647 outputs
Outputs from Molecular and Cellular Biochemistry
#481
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Outputs of similar age
#11,275
of 34,663 outputs
Outputs of similar age from Molecular and Cellular Biochemistry
#1
of 5 outputs
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