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Hepatic CYP3A4 Enzyme Compensatively Maintains Endogenous Geranylgeranoic Acid Levels in MAOB-Knockout Human Hepatoma Cells

Geranylgeranoic acid (GGA), developed as a preventive agent against second primary hepatoma, has been reported to be biosynthesized via the mevalonate pathway in human hepatoma-derived cells. Recently, we found that monoamine oxidase B (MAOB) catalyzed the oxidation of geranylgeraniol (GGOH) to prod...

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Autores principales: Tabata, Yuki, Shidoji, Yoshihiro
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2022
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8880059/
https://www.ncbi.nlm.nih.gov/pubmed/35208214
http://dx.doi.org/10.3390/metabo12020140
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author Tabata, Yuki
Shidoji, Yoshihiro
author_facet Tabata, Yuki
Shidoji, Yoshihiro
author_sort Tabata, Yuki
collection PubMed
description Geranylgeranoic acid (GGA), developed as a preventive agent against second primary hepatoma, has been reported to be biosynthesized via the mevalonate pathway in human hepatoma-derived cells. Recently, we found that monoamine oxidase B (MAOB) catalyzed the oxidation of geranylgeraniol (GGOH) to produce geranylgeranial (GGal), a direct precursor of endogenous GGA in hepatoma cells, using tranylcypromine, an inhibitor of MAOs, and knockdown by MAOB siRNA. However, endogenous GGA level was unexpectedly unchanged in MAOB-knockout (KO) cells established using the CRISPR-Cas9 system, suggesting that some other latent metabolic pathways maintain endogenous GGA levels in the MAOB-KO cells. Here, we investigated the putative latent enzymes that oxidize GGOH in Hep3B/MAOB-KO cells. First, the broad-specific cytochrome P450 enzyme inhibitors decreased the amount of endogenous GGA in Hep3B/MAOB-KO cells in a dose-dependent manner. Second, among the eight members of cytochrome P450 superfamily that have been suggested to be involved in the oxidation of isoprenols and/or retinol in previous studies, only the CYP3A4 gene significantly upregulated its cellular mRNA level in Hep3B/MAOB-KO cells. Third, a commercially available recombinant human CYP3A4 enzyme was able to oxidize GGOH to GGal, and fourth, the knockdown of CYP3A4 by siRNA significantly reduced the amount of endogenous GGA in Hep3B/MAOB-KO cells. These results indicate that CYP3A4 can act as an alternative oxidase for GGOH when hepatic MAOB is deleted in the human hepatoma-derived cell line Hep3B, and that endogenous GGA levels are maintained by a multitude of enzymes.
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spelling pubmed-88800592022-02-26 Hepatic CYP3A4 Enzyme Compensatively Maintains Endogenous Geranylgeranoic Acid Levels in MAOB-Knockout Human Hepatoma Cells Tabata, Yuki Shidoji, Yoshihiro Metabolites Article Geranylgeranoic acid (GGA), developed as a preventive agent against second primary hepatoma, has been reported to be biosynthesized via the mevalonate pathway in human hepatoma-derived cells. Recently, we found that monoamine oxidase B (MAOB) catalyzed the oxidation of geranylgeraniol (GGOH) to produce geranylgeranial (GGal), a direct precursor of endogenous GGA in hepatoma cells, using tranylcypromine, an inhibitor of MAOs, and knockdown by MAOB siRNA. However, endogenous GGA level was unexpectedly unchanged in MAOB-knockout (KO) cells established using the CRISPR-Cas9 system, suggesting that some other latent metabolic pathways maintain endogenous GGA levels in the MAOB-KO cells. Here, we investigated the putative latent enzymes that oxidize GGOH in Hep3B/MAOB-KO cells. First, the broad-specific cytochrome P450 enzyme inhibitors decreased the amount of endogenous GGA in Hep3B/MAOB-KO cells in a dose-dependent manner. Second, among the eight members of cytochrome P450 superfamily that have been suggested to be involved in the oxidation of isoprenols and/or retinol in previous studies, only the CYP3A4 gene significantly upregulated its cellular mRNA level in Hep3B/MAOB-KO cells. Third, a commercially available recombinant human CYP3A4 enzyme was able to oxidize GGOH to GGal, and fourth, the knockdown of CYP3A4 by siRNA significantly reduced the amount of endogenous GGA in Hep3B/MAOB-KO cells. These results indicate that CYP3A4 can act as an alternative oxidase for GGOH when hepatic MAOB is deleted in the human hepatoma-derived cell line Hep3B, and that endogenous GGA levels are maintained by a multitude of enzymes. MDPI 2022-02-03 /pmc/articles/PMC8880059/ /pubmed/35208214 http://dx.doi.org/10.3390/metabo12020140 Text en © 2022 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
Tabata, Yuki
Shidoji, Yoshihiro
Hepatic CYP3A4 Enzyme Compensatively Maintains Endogenous Geranylgeranoic Acid Levels in MAOB-Knockout Human Hepatoma Cells
title Hepatic CYP3A4 Enzyme Compensatively Maintains Endogenous Geranylgeranoic Acid Levels in MAOB-Knockout Human Hepatoma Cells
title_full Hepatic CYP3A4 Enzyme Compensatively Maintains Endogenous Geranylgeranoic Acid Levels in MAOB-Knockout Human Hepatoma Cells
title_fullStr Hepatic CYP3A4 Enzyme Compensatively Maintains Endogenous Geranylgeranoic Acid Levels in MAOB-Knockout Human Hepatoma Cells
title_full_unstemmed Hepatic CYP3A4 Enzyme Compensatively Maintains Endogenous Geranylgeranoic Acid Levels in MAOB-Knockout Human Hepatoma Cells
title_short Hepatic CYP3A4 Enzyme Compensatively Maintains Endogenous Geranylgeranoic Acid Levels in MAOB-Knockout Human Hepatoma Cells
title_sort hepatic cyp3a4 enzyme compensatively maintains endogenous geranylgeranoic acid levels in maob-knockout human hepatoma cells
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8880059/
https://www.ncbi.nlm.nih.gov/pubmed/35208214
http://dx.doi.org/10.3390/metabo12020140
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