5 results on '"Siculella, Luisa"'
Search Results
2. Differential effects of coconut oil- and fish oil-enriched diets on tricarboxylate carrier in rat liver mitochondria
- Author
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Giudetti, Anna Maria, primary, Sabetta, Simona, additional, di Summa, Roberta, additional, Leo, Monica, additional, Damiano, Fabrizio, additional, Siculella, Luisa, additional, and Gnoni, Gabriele V., additional
- Published
- 2003
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3. Oleic acid is a potent inhibitor of fatty acid and cholesterol synthesis in C6 glioma cells
- Author
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Francesco Natali, Gabriele V. Gnoni, Luisa Siculella, Serafina Salvati, Natali, F, Siculella, Luisa, Salvati, S, and Gnoni, Gabriele Vincenzo
- Subjects
Coenzyme A ,Acetyl-CoA carboxylase ,QD415-436 ,Acetates ,Biology ,lipogenensis ,Fatty acid synthase ,Biochemistry ,chemistry.chemical_compound ,Endocrinology ,Cell Line, Tumor ,Animals ,RNA, Messenger ,chemistry.chemical_classification ,acetyl-coenzyme A carboxylase ,fatty acid synthase ,Fatty acid metabolism ,Lipogenesis ,Fatty Acids ,Fatty acid ,Glioma ,Cell Biology ,Rats ,Oleic acid ,Cholesterol ,chemistry ,cholesterologenesis ,Fatty Acids, Unsaturated ,biology.protein ,Free fatty acid receptor ,Hydroxymethylglutaryl CoA Reductases ,lipids (amino acids, peptides, and proteins) ,Fatty Acid Synthases ,3-hydroxy-3-methylglutaryl coenzyme A reductase ,Cholesterologenesi ,Acetyl-CoA Carboxylase ,Oleic Acid ,Polyunsaturated fatty acid - Abstract
Glial cells play a pivotal role in brain fatty acid metabolism and membrane biogenesis. However, the potential regulation of lipogenesis and cholesterologenesis by fatty acids in glial cells has been barely investigated. Here, we show that physiologically relevant concentrations of various saturated, monounsaturated, and polyunsaturated fatty acids significantly reduce [1-(14)C]acetate incorporation into fatty acids and cholesterol in C6 cells. Oleic acid was the most effective at depressing lipogenesis and cholesterologenesis; a decreased label incorporation into cellular palmitic, stearic, and oleic acids was detected, suggesting that an enzymatic step(s) of de novo fatty acid biosynthesis was affected. To clarify this issue, the activities of acetyl-coenzyme A carboxylase (ACC) and FAS were determined with an in situ digitonin-permeabilized cell assay after incubation of C6 cells with fatty acids. ACC activity was strongly reduced ( approximately 80%) by oleic acid, whereas no significant change in FAS activity was observed. Oleic acid also reduced the activity of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR). The inhibition of ACC and HMGCR activities is corroborated by the decreases in ACC and HMGCR mRNA abundance and protein levels. The downregulation of ACC and HMGCR activities and expression by oleic acid could contribute to the reduced lipogenesis and cholesterologenesis.
- Published
- 2007
4. n-6 PUFAs downregulate expression of the tricarboxylate carrier in rat liver by transcriptional and posttranscriptional mechanisms
- Author
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Luisa Siculella, Simona Sabetta, Gabriele V. Gnoni, Fabrizio Damiano, Siculella, Luisa, Damiano, Fabrizio, Sabetta, S., and Gnoni, Gabriele Vincenzo
- Subjects
Male ,Transcription, Genetic ,RNA Stability ,Mitochondria, Liver ,Acetyl-CoA carboxylase ,Mitochondrion ,urologic and male genital diseases ,Biochemistry ,Endocrinology ,Gene expression ,RNA Precursors ,RNA Processing, Post-Transcriptional ,Inner mitochondrial membrane ,Safflower Oil ,Regulation of gene expression ,Gene modulation ,Malic enzyme ,Run-on assay ,female genital diseases and pregnancy complications ,Stearoyl-CoA desaturase ,Mitochondria ,mitochondria ,Polyunsaturated fatty acid ,Lipogenesis ,Safflower oil ,polyunsaturated fatty acids ,Down-Regulation ,QD415-436 ,Tricarboxylate carrier ,Biology ,mRNA turnover ,Tricarboxylate ,gene modulation ,Fatty Acids, Omega-6 ,Ribonuclease protection assay ,Animals ,RNA, Messenger ,Rats, Wistar ,lipogenesis ,Glucose-6-phosphate dehydrogenase ,Messenger RNA ,Lipogenesi ,ribonuclease protection assay ,Nuclease protection assay ,Cell Biology ,Molecular biology ,Rats ,Gene Expression Regulation ,Hepatocytes ,Carrier Proteins ,L-pyruvate kinase - Abstract
The tricarboxylate (citrate) carrier (TCC), a protein of the mitochondrial inner membrane, is an obligatory component of the shuttle system by which mitochondrial acetyl-CoA is transported into the cytosol, where lipogenesis occurs. The aim of this study was to investigate the molecular basis for the regulation of TCC gene expression by a high-fat, n-6 PUFA-enriched diet. Rats received for up to 4 weeks a diet enriched with 15% safflower oil (SO), which is high in linoleic acid (70.4%). We found a gradual decrease of TCC activity and a parallel decline in the abundance of TCC mRNA, the maximum effect occurring after 4 weeks of treatment. At this time, the estimated half-life of TCC mRNA was the same in the hepatocytes from rats on both diets, whereas the transcriptional rate of TCC mRNA, tested by nuclear run-on assay, was reduced by approximately 38% in the rats on the SO-enriched diet. The RNase protection assay showed that the ratio of mature to precursor RNA, measured in the nuclei, decreased with the change to the n-6 PUFA diet. These results suggest that administration of n-6 PUFAs to rats leads to changes not only in the transcriptional rate of the TCC gene but also in the processing of the nuclear precursor for TCC RNA.
- Published
- 2004
5. Differential effects of coconut oil- and fish oil-enriched diets on tricarboxylate carrier in rat liver mitochondria
- Author
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Monica Leo, Fabrizio Damiano, Anna Maria Giudetti, Luisa Siculella, Simona Sabetta, Roberta di Summa, Gabriele V. Gnoni, Giudetti, Anna Maria, Sabetta, S, DI SUMMA, R, Leo, M, Damiano, Fabrizio, Siculella, Luisa, and Gnoni, Gabriele Vincenzo
- Subjects
Male ,food.ingredient ,Saturated fat ,Phospholipid ,Saturated fatty acid ,lipogenic gene regulation ,Mitochondria, Liver ,QD415-436 ,Biology ,fatty acids ,Biochemistry ,Citric Acid ,chemistry.chemical_compound ,Endocrinology ,food ,Fish Oils ,Animals ,Plant Oils ,RNA, Messenger ,Rats, Wistar ,Fatty acid synthesis ,lipogenesis ,phospholipids ,chemistry.chemical_classification ,Coconut oil ,Lipogenesi ,Fatty acid ,cholesterol ,Biological Transport ,Cell Biology ,Fish oil ,Dietary Fats ,Rats ,Kinetics ,Cholesterol ,Lipogenic gene regulation ,chemistry ,n-3 polyunsaturated fatty acid ,Lipogenesis ,Coconut Oil ,Hepatocytes ,Carrier Proteins ,Polyunsaturated fatty acid - Abstract
The mitochondrial tricarboxylate carrier (TCC) plays an important role in lipogenesis being TCC-responsible for the efflux from the mitochondria to the cytosol of acetyl-CoA, the primer for fatty acid synthesis. In this study, we investigated the effects of two high-fat diets with different fatty acid composition on the hepatic TCC activity. Rats were fed for 3 weeks on a basal diet supplemented with 15% of either coconut oil (CO), abundant in medium-chain saturated fatty acids, or fish oil (FO), rich in n-3 polyunsaturated fatty acids. Mitochondrial fatty acid composition was differently influenced by the dietary treatments, while no appreciable change in phospholipid composition and cholesterol level was observed. Compared with CO, the TCC activity was markedly decreased in liver mitochondria from FO-fed rats; kinetic analysis of the carrier revealed a decrease of the Vmax, with no change of the Km. No difference in the Arrhenius plot between the two groups was observed. Interestingly, the carrier protein level and the corresponding mRNA abundance decreased following FO treatment. These data indicate that FO administration markedly decreased the TCC activity as compared with CO. This effect is most likely due to a reduced gene expression of the carrier protein.
- Published
- 2003
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