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PPARα Induces the Expression of CAR That Works as a Negative Regulator of PPARα Functions in Mouse Livers
The nuclear receptor peroxisome proliferator-activated receptor α (PPARα) is a transcription factor that controls the transcription of genes responsible for fatty acid metabolism. We have recently reported a possible drug–drug interaction mechanism via the interaction of PPARα with the xenobiotic nu...
Autores principales: | , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2023
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9960678/ https://www.ncbi.nlm.nih.gov/pubmed/36835365 http://dx.doi.org/10.3390/ijms24043953 |
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author | Shizu, Ryota Otsuka, Yuta Ishii, Chizuru Ezaki, Kanako Yoshinari, Kouichi |
author_facet | Shizu, Ryota Otsuka, Yuta Ishii, Chizuru Ezaki, Kanako Yoshinari, Kouichi |
author_sort | Shizu, Ryota |
collection | PubMed |
description | The nuclear receptor peroxisome proliferator-activated receptor α (PPARα) is a transcription factor that controls the transcription of genes responsible for fatty acid metabolism. We have recently reported a possible drug–drug interaction mechanism via the interaction of PPARα with the xenobiotic nuclear receptor constitutive androstane receptor (CAR). Drug-activated CAR competes with the transcriptional coactivator against PPARα and prevents PPARα-mediated lipid metabolism. In this study, to elucidate the crosstalk between CAR and PPARα, we focused on the influence of PPARα activation on CAR’s gene expression and activation. Male C57BL/6N mice (8–12 weeks old, n = 4) were treated with PPARα and CAR activators (fenofibrate and phenobarbital, respectively), and hepatic mRNA levels were determined using quantitative reverse transcription PCR. Reporter assays using the mouse Car promoter were performed in HepG2 cells to determine the PPARα-dependent induction of CAR. CAR KO mice were treated with fenofibrate, and the hepatic mRNA levels of PPARα target genes were determined. Treatment of mice with a PPARα activator increased Car mRNA levels as well as genes related to fatty acid metabolism. In reporter assays, PPARα induced the promoter activity of the Car gene. Mutation of the putative PPARα-binding motif prevented PPARα-dependent induction of reporter activity. In electrophoresis mobility shift assay, PPARα bound to the DR1 motif of the Car promoter. Since CAR has been reported to attenuate PPARα-dependent transcription, CAR was considered a negative feedback protein for PPARα activation. Treatment with fenofibrate induced the mRNA levels of PPARα target genes in Car-null mice more than those in wild-type mice, suggesting that CAR functions as a negative feedback factor for PPARα. |
format | Online Article Text |
id | pubmed-9960678 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2023 |
publisher | MDPI |
record_format | MEDLINE/PubMed |
spelling | pubmed-99606782023-02-26 PPARα Induces the Expression of CAR That Works as a Negative Regulator of PPARα Functions in Mouse Livers Shizu, Ryota Otsuka, Yuta Ishii, Chizuru Ezaki, Kanako Yoshinari, Kouichi Int J Mol Sci Article The nuclear receptor peroxisome proliferator-activated receptor α (PPARα) is a transcription factor that controls the transcription of genes responsible for fatty acid metabolism. We have recently reported a possible drug–drug interaction mechanism via the interaction of PPARα with the xenobiotic nuclear receptor constitutive androstane receptor (CAR). Drug-activated CAR competes with the transcriptional coactivator against PPARα and prevents PPARα-mediated lipid metabolism. In this study, to elucidate the crosstalk between CAR and PPARα, we focused on the influence of PPARα activation on CAR’s gene expression and activation. Male C57BL/6N mice (8–12 weeks old, n = 4) were treated with PPARα and CAR activators (fenofibrate and phenobarbital, respectively), and hepatic mRNA levels were determined using quantitative reverse transcription PCR. Reporter assays using the mouse Car promoter were performed in HepG2 cells to determine the PPARα-dependent induction of CAR. CAR KO mice were treated with fenofibrate, and the hepatic mRNA levels of PPARα target genes were determined. Treatment of mice with a PPARα activator increased Car mRNA levels as well as genes related to fatty acid metabolism. In reporter assays, PPARα induced the promoter activity of the Car gene. Mutation of the putative PPARα-binding motif prevented PPARα-dependent induction of reporter activity. In electrophoresis mobility shift assay, PPARα bound to the DR1 motif of the Car promoter. Since CAR has been reported to attenuate PPARα-dependent transcription, CAR was considered a negative feedback protein for PPARα activation. Treatment with fenofibrate induced the mRNA levels of PPARα target genes in Car-null mice more than those in wild-type mice, suggesting that CAR functions as a negative feedback factor for PPARα. MDPI 2023-02-16 /pmc/articles/PMC9960678/ /pubmed/36835365 http://dx.doi.org/10.3390/ijms24043953 Text en © 2023 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Article Shizu, Ryota Otsuka, Yuta Ishii, Chizuru Ezaki, Kanako Yoshinari, Kouichi PPARα Induces the Expression of CAR That Works as a Negative Regulator of PPARα Functions in Mouse Livers |
title | PPARα Induces the Expression of CAR That Works as a Negative Regulator of PPARα Functions in Mouse Livers |
title_full | PPARα Induces the Expression of CAR That Works as a Negative Regulator of PPARα Functions in Mouse Livers |
title_fullStr | PPARα Induces the Expression of CAR That Works as a Negative Regulator of PPARα Functions in Mouse Livers |
title_full_unstemmed | PPARα Induces the Expression of CAR That Works as a Negative Regulator of PPARα Functions in Mouse Livers |
title_short | PPARα Induces the Expression of CAR That Works as a Negative Regulator of PPARα Functions in Mouse Livers |
title_sort | pparα induces the expression of car that works as a negative regulator of pparα functions in mouse livers |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9960678/ https://www.ncbi.nlm.nih.gov/pubmed/36835365 http://dx.doi.org/10.3390/ijms24043953 |
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