Fenofibrate modifies transaminase gene expression via a peroxisome proliferator activated receptor α-dependent pathway
| Autor: | Martine Aggerbeck, J Bouguet, Claire Guyomard, Philippe Costet, Christiane Legendre, Alan D Edgar, Céline Tomkiewicz, Bart Staels, Thierry Pineau, Robert Barouki |
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| Rok vydání: | 1998 |
| Předmět: |
medicine.medical_specialty
Receptors Cytoplasmic and Nuclear Peroxisome proliferator-activated receptor Aspartate transaminase Toxicology Gene Expression Regulation Enzymologic Transaminase Mice chemistry.chemical_compound Fenofibrate Internal medicine Gene expression Tumor Cells Cultured medicine Animals Humans Aspartate Aminotransferases RNA Messenger Cells Cultured Transaminases Hypolipidemic Agents chemistry.chemical_classification Fatty acid metabolism biology Nuclear Proteins Alanine Transaminase General Medicine Peroxisome Blotting Northern Endocrinology Liver chemistry Alanine transaminase biology.protein Transcription Factors medicine.drug |
| Zdroj: | Toxicology Letters. 98:13-23 |
| ISSN: | 0378-4274 |
| DOI: | 10.1016/s0378-4274(98)00042-3 |
| Popis: | Fibrates modify the expression of genes implicated in lipoprotein and fatty acid metabolism via the peroxisome proliferator-activated receptor alpha(PPARalpha), leading to reductions in serum triglycerides and cholesterol. The expression of certain genes regulated by PPARalpha have been shown to be modified in a species dependent manner. Aspartate aminotransferase (AspAT or GOT) and alanine aminotransferase (AlaAT or GPT) are enzymes involved in intermediate metabolism in all cells and in hepatic gluconeogenesis. These enzymes are also widely used as serum markers of possible tissue damage. This study investigated whether fenofibrate could modify the expression of liver AspAT and/or AlaAT and thus possibly alter transaminase levels independently of a cytotoxic effect. In human Hep G2 cells, fenofibrate increased cytosolic AspAT (cAspAT) activity by 40% and AlaAT activity by 100%, as well as both mRNAs. Nuclear run on assays showed that this effect was, at least in part, transcriptional. Increases in mRNA were also observed in human hepatocyte cultures at concentrations of the drug attained in patients. In C57BL/6 mice, fenofibrate decreased cAspAT and cAlaAT mRNA, while these effects were abolished in PPARalpha knock-out mice. In conclusion, fenofibrate has been shown to modify cAspAT and AlaAT gene expression in a species and PPARalpha dependent manner. This is the first demonstration that cAspAT and AlaAT activities may be pharmacologically altered, independently of a toxic phenomenon. |
| Databáze: | OpenAIRE |
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