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Berge RK, Cacabelos D, Señarís R, Nordrehaug JE, Nygård O, Skorve J, Bjørndal B. Hepatic steatosis induced in C57BL/6 mice by a non-ß oxidizable fatty acid analogue is associated with reduced plasma kynurenine metabolites and a modified hepatic NAD +/NADH ratio. Lipids Health Dis 2020; 19:94. [PMID: 32410680 PMCID: PMC7227213 DOI: 10.1186/s12944-020-01271-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 04/29/2020] [Indexed: 01/14/2023] Open
Abstract
Background Non-alcoholic fatty liver disease is often associated with obesity, insulin resistance, dyslipidemia, and the metabolic syndrome in addition to mitochondrial dysfunction and nicotinamide adenine dinucleotide (NAD+) deficiency. The aim of this study was to investigate how inhibition of mitochondrial fatty acid oxidation using the compound tetradecylthiopropionic acid (TTP) would affect hepatic triacylglycerol level and plasma levels of kynurenine (Kyn) metabolites and nicotinamide. Methods 12 C57BL/6 mice were fed a control diet, or an intervention diet supplemented with 0.9% (w/w) tetradecylthiopropionic acid for 14 days. Blood and liver samples were collected, enzyme activities and gene expression were analyzed in liver, in addition to fatty acid composition. Metabolites in the tryptophan/kynurenine pathway and total antioxidant status were measured in plasma. Results Dietary treatment with tetradecylthiopropionic acid for 2 weeks induced fatty liver accompanied by decreased mitochondrial fatty acid oxidation. The liver content of the oxidized form of NAD+ was increased, as well as the ratio of NAD+/NADH, and these changes were associated by increased hepatic mRNA levels of NAD synthetase and nicotinamide mononucleotide adenyltransferase-3. The downstream metabolites of kynurenine were reduced in plasma whereas the plasma nicotinamide content was increased. Some effects on inflammation and oxidative stress was observed in the liver, while the plasma antioxidant capacity was increased. This was accompanied by a reduced plasma ratio of kynurenine/tryptophan. In addition, a significant decrease in the inflammation-related arachidonic fatty acid in liver was observed. Conclusion Fatty liver induced by short-time treatment with tetradecylthiopropionic acid decreased the levels of kynurenine metabolites but increased the plasma levels of NAD+ and nicotinamide. These changes are most likely not associated with increased inflammation and oxidative stress. Most probably the increase of NAD+ and nicotinamide are generated through the Preiss Handler pathway and/or salvage pathway and not through the de novo pathway. The take home message is that non-alcoholic fatty liver disease is associated with the metabolic syndrome in addition to mitochondrial dysfunction and nicotinamide adenine dinucleotide (NAD+) deficiency. Inducing fatty liver in mice by inhibition of fatty acid oxidation resulted in a concomitant change in kynurenine metabolites increasing the plasma levels of nicotinamides and the hepatic NAD+/NADH ratio, probably without affecting the de novo pathway of kynurenines.
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Affiliation(s)
- Rolf K Berge
- Department of Clinical Science, University of Bergen, Bergen, Norway. .,Department of Heart Disease, Haukeland University Hospital, Bergen, Norway.
| | - Daniel Cacabelos
- Department of Clinical Science, University of Bergen, Bergen, Norway.,Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela, Spain
| | - Rosa Señarís
- Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela, Spain
| | - Jan Erik Nordrehaug
- Department of Clinical Science, University of Bergen, Bergen, Norway.,Department of Heart Disease, Stavanger University Hospital, Stavanger, Norway
| | - Ottar Nygård
- Department of Clinical Science, University of Bergen, Bergen, Norway.,Department of Heart Disease, Haukeland University Hospital, Bergen, Norway.,KG Jebsen Centre for Diabetes Research, University of Bergen, Bergen, Norway
| | - Jon Skorve
- Department of Clinical Science, University of Bergen, Bergen, Norway
| | - Bodil Bjørndal
- Department of Clinical Science, University of Bergen, Bergen, Norway
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Lundåsen T, Pedrelli M, Bjørndal B, Rozell B, Kuiper RV, Burri L, Pavanello C, Turri M, Skorve J, Berge RK, Alexson SEH, Tillander V. The PPAR pan-agonist tetradecylthioacetic acid promotes redistribution of plasma cholesterol towards large HDL. PLoS One 2020; 15:e0229322. [PMID: 32176696 PMCID: PMC7075573 DOI: 10.1371/journal.pone.0229322] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Accepted: 02/04/2020] [Indexed: 12/16/2022] Open
Abstract
Tetradecylthioacetic acid (TTA) is a synthetic fatty acid with a sulfur substitution in the β-position. This modification renders TTA unable to undergo complete β-oxidation and increases its biological activity, including activation of peroxisome proliferator activated receptors (PPARs) with preference for PPARα. This study investigated the effects of TTA on lipid and lipoprotein metabolism in the intestine and liver of mice fed a high fat diet (HFD). Mice receiving HFD supplemented with 0.75% (w/w) TTA had significantly lower body weights compared to mice fed the diet without TTA. Plasma triacylglycerol (TAG) was reduced 3-fold with TTA treatment, concurrent with increase in liver TAG. Total cholesterol was unchanged in plasma and liver. However, TTA promoted a shift in the plasma lipoprotein fractions with an increase in larger HDL particles. Histological analysis of the small intestine revealed a reduced size of lipid droplets in enterocytes of TTA treated mice, accompanied by increased mRNA expression of fatty acid transporter genes. Expression of the cholesterol efflux pump Abca1 was induced in the small intestine, but not in the liver. Scd1 displayed markedly increased mRNA and protein expression in the intestine of the TTA group. It is concluded that TTA treatment of HFD fed mice leads to increased expression of genes involved in uptake and transport of fatty acids and HDL cholesterol in the small intestine with concomitant changes in the plasma profile of smaller lipoproteins.
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Affiliation(s)
- Thomas Lundåsen
- Department of Laboratory Medicine, Karolinska Institutet, Huddinge, Sweden
| | - Matteo Pedrelli
- Department of Laboratory Medicine, Karolinska Institutet, Huddinge, Sweden
- Translational Science and Experimental Medicine, Research and Early Development, Cardiovascular Renal and Metabolism (CVRM), BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Bodil Bjørndal
- Department of Clinical Science, University of Bergen, Bergen, Norway
- Department of Sports, Physical activity and Food, Faculty of Education, Arts and Sports, Western Norway University of Applied Sciences, Bergen, Norway
- * E-mail: (BB); (VT)
| | - Björn Rozell
- Department of Laboratory Medicine, Karolinska Institutet, Huddinge, Sweden
| | - Raoul V. Kuiper
- Department of Laboratory Medicine, Karolinska Institutet, Huddinge, Sweden
| | - Lena Burri
- Department of Clinical Science, University of Bergen, Bergen, Norway
| | - Chiara Pavanello
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Centro Enrica Grossi Paoletti, Università degli Studi di Milano, Milan, Italy
| | - Marta Turri
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Centro Enrica Grossi Paoletti, Università degli Studi di Milano, Milan, Italy
| | - Jon Skorve
- Department of Clinical Science, University of Bergen, Bergen, Norway
| | - Rolf K. Berge
- Department of Clinical Science, University of Bergen, Bergen, Norway
- Department of Heart Disease, Haukeland University Hospital, Bergen, Norway
| | | | - Veronika Tillander
- Department of Laboratory Medicine, Karolinska Institutet, Huddinge, Sweden
- * E-mail: (BB); (VT)
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Bjørndal B, Alterås EK, Lindquist C, Svardal A, Skorve J, Berge RK. Associations between fatty acid oxidation, hepatic mitochondrial function, and plasma acylcarnitine levels in mice. Nutr Metab (Lond) 2018; 15:10. [PMID: 29422939 PMCID: PMC5789604 DOI: 10.1186/s12986-018-0241-7] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Accepted: 01/10/2018] [Indexed: 02/07/2023] Open
Abstract
Background The 4-thia fatty acid tetradecylthiopropionic acid (TTP) is known to inhibit mitochondrial β-oxidation, and can be used as chemically induced hepatic steatosis-model in rodents, while 3-thia fatty acid tetradecylthioacetic acid (TTA) stimulates fatty acid oxidation through activation of peroxisome proliferator activated receptor alpha (PPARα). We wished to determine how these two compounds affected in vivo respiration and mitochondrial efficiency, with an additional goal to elucidate whether mitochondrial function is reflected in plasma acylcarnitine levels. Methods C57BL/6 mice were divided in 4 groups of 10 mice and fed a control low-fat diet, low-fat diets with 0.4% (w/w) TTP, 0.4% TTA or a combination of these two fatty acids for three weeks (n = 10). At sacrifice, β-oxidation and oxidative phosphorylation (OXPHOS) capacity was analysed in fresh liver samples. Hepatic mitochondria were studied using transmission electron microscopy. Lipid classes were measured in plasma, heart and liver, acylcarnitines were measured in plasma, and gene expression was measured in liver. Results The TTP diet resulted in hepatic lipid accumulation, plasma L-carnitine and acetylcarnitine depletion and elevated palmitoylcarnitine and non-esterified fatty acid levels. No significant lipid accumulation was observed in heart. The TTA supplement resulted in enhanced hepatic β-oxidation, accompanied by an increased level of acetylcarnitine and palmitoylcarnitine in plasma. Analysis of mitochondrial respiration showed that TTP reduced oxidative phosphorylation, while TTA increased the maximum respiratory capacity of the electron transport system. Combined treatment with TTP and TTA resulted in a profound stimulation of genes involved in the PPAR-response and L-carnitine metabolism, and partly prevented triacylglycerol accumulation in the liver concomitant with increased peroxisomal β-oxidation and depletion of plasma acetylcarnitines. Despite an increased number of mitochondria in the liver of TTA + TTP fed mice, the OXPHOS capacity was significantly reduced. Conclusion This study indicates that fatty acid β-oxidation directly affects mitochondrial respiratory capacity in liver. As plasma acylcarnitines reflected the reduced mitochondrial β-oxidation in TTP-fed mice, they could be useful tools to monitor mitochondrial function. As mitochondrial dysfunction is a major determinant of metabolic disease, this supports their use as plasma markers of cardiovascular risk in humans. Results however indicate that high PPAR activation obscures the interpretation of plasma acylcarnitine levels. Electronic supplementary material The online version of this article (10.1186/s12986-018-0241-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Bodil Bjørndal
- 1Department of Clinical Science, University of Bergen, N-5020 Bergen, Norway
| | - Eva Katrine Alterås
- 1Department of Clinical Science, University of Bergen, N-5020 Bergen, Norway
| | - Carine Lindquist
- 1Department of Clinical Science, University of Bergen, N-5020 Bergen, Norway.,2Department of Heart Disease, Haukeland University Hospital, N-5021 Bergen, Norway
| | - Asbjørn Svardal
- 1Department of Clinical Science, University of Bergen, N-5020 Bergen, Norway
| | - Jon Skorve
- 1Department of Clinical Science, University of Bergen, N-5020 Bergen, Norway
| | - Rolf K Berge
- 1Department of Clinical Science, University of Bergen, N-5020 Bergen, Norway.,2Department of Heart Disease, Haukeland University Hospital, N-5021 Bergen, Norway
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Lund J, Stensrud C, Rajender, Bohov P, Thoresen GH, Berge RK, Wright M, Kamal A, Rustan AC, Miller AD, Skorve J. The molecular structure of thio-ether fatty acids influences PPAR-dependent regulation of lipid metabolism. Bioorg Med Chem 2016; 24:1191-203. [PMID: 26874397 DOI: 10.1016/j.bmc.2016.01.045] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Revised: 01/19/2016] [Accepted: 01/21/2016] [Indexed: 10/22/2022]
Abstract
Thio-ether fatty acids (THEFAs), including the parent 2-(tetradecylthio)acetic acid (TTA), are modified fatty acids (FAs) that have profound effects on lipid metabolism given that they are blocked for β-oxidation, and able to act as peroxisome proliferator-activated receptor (PPAR) agonists. Therefore, TTA in particular has been tested clinically for its therapeutic potential against metabolic syndrome related disorders. Here, we describe the preparation of THEFAs based on the TTA scaffold with either a double or a triple bond. These are tested in cultured human skeletal muscle cells (myotubes), either as free acid or following esterification as phospholipids, lysophospholipids or monoacylglycerols. Metabolic effects are assessed in terms of cellular bioavailabilities in myotubes, by FA substrate uptake and oxidation studies, and gene regulation studies with selected PPAR-regulated genes. We note that the inclusion of a triple bond promotes THEFA-mediated FA oxidation. Furthermore, esterification of THEFAs as lysophospholipids also promotes FA oxidation effects. Given that the apparent clinical benefits of TTA administration were offset by dose limitation and poor bioavailability, we discuss the possibility that a selection of our latest THEFAs and THEFA-containing lipids might be able to fulfill the therapeutic potential of the parent TTA while minimizing required doses for efficacy, side-effects and adverse reactions.
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Affiliation(s)
- Jenny Lund
- Department of Pharmaceutical Biosciences, School of Pharmacy, University of Oslo, Norway
| | - Camilla Stensrud
- Department of Pharmaceutical Biosciences, School of Pharmacy, University of Oslo, Norway
| | - Rajender
- Imperial College Genetic Therapies Centre, Department of Chemistry, Flowers Building, Imperial College London, UK; Division of Organic Chemistry, Indian Institute of Chemical Technology, Hyderabad, India
| | - Pavol Bohov
- Department of Clinical Science, University of Bergen, N-5021 Bergen, Norway
| | - G Hege Thoresen
- Department of Pharmaceutical Biosciences, School of Pharmacy, University of Oslo, Norway; Department of Pharmacology, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo and Oslo University Hospital, Norway
| | - Rolf K Berge
- Department of Clinical Science, University of Bergen, N-5021 Bergen, Norway; Department of Heart Disease, Haukeland University Hospital, Norway
| | - Michael Wright
- Imperial College Genetic Therapies Centre, Department of Chemistry, Flowers Building, Imperial College London, UK; Institute of Pharmaceutical Science, Franklin-Wilkins Building, King's College London, UK
| | - Ahmed Kamal
- Division of Organic Chemistry, Indian Institute of Chemical Technology, Hyderabad, India
| | - Arild C Rustan
- Department of Pharmaceutical Biosciences, School of Pharmacy, University of Oslo, Norway
| | - Andrew D Miller
- Division of Organic Chemistry, Indian Institute of Chemical Technology, Hyderabad, India; Institute of Pharmaceutical Science, Franklin-Wilkins Building, King's College London, UK; GlobalAcorn Ltd, London, UK
| | - Jon Skorve
- Department of Clinical Science, University of Bergen, N-5021 Bergen, Norway.
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Beld J, Abbriano R, Finzel K, Hildebrand M, Burkart MD. Probing fatty acid metabolism in bacteria, cyanobacteria, green microalgae and diatoms with natural and unnatural fatty acids. MOLECULAR BIOSYSTEMS 2016; 12:1299-312. [PMID: 26886879 DOI: 10.1039/c5mb00804b] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
In both eukaryotes and prokaryotes, fatty acid synthases are responsible for the biosynthesis of fatty acids in an iterative process, extending the fatty acid by two carbon units every cycle. Thus, odd numbered fatty acids are rarely found in nature. We tested whether representatives of diverse microbial phyla have the ability to incorporate odd-chain fatty acids as substrates for their fatty acid synthases and their downstream enzymes. We fed various odd and short chain fatty acids to the bacterium Escherichia coli, cyanobacterium Synechocystis sp. PCC 6803, green microalga Chlamydomonas reinhardtii and diatom Thalassiosira pseudonana. Major differences were observed, specifically in the ability among species to incorporate and elongate short chain fatty acids. We demonstrate that E. coli, C. reinhardtii, and T. pseudonana can produce longer fatty acid products from short chain precursors (C3 and C5), while Synechocystis sp. PCC 6803 lacks this ability. However, Synechocystis can incorporate and elongate longer chain fatty acids due to acyl-acyl carrier protein synthetase (AasS) activity, and knockout of this protein eliminates the ability to incorporate these fatty acids. In addition, expression of a characterized AasS from Vibrio harveyii confers a similar capability to E. coli. The ability to desaturate exogenously added fatty acids was only observed in Synechocystis and C. reinhardtii. We further probed fatty acid metabolism of these organisms by feeding desaturase inhibitors to test the specificity of long-chain fatty acid desaturases. In particular, supplementation with thia fatty acids can alter fatty acid profiles based on the location of the sulfur in the chain. We show that coupling sensitive gas chromatography mass spectrometry to supplementation of unnatural fatty acids can reveal major differences between fatty acid metabolism in various organisms. Often unnatural fatty acids have antibacterial or even therapeutic properties. Feeding of short precursors now gives us easy access to these extended molecules.
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Affiliation(s)
- Joris Beld
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0358, USA.
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6
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Berge RK, Bjørndal B, Strand E, Bohov P, Lindquist C, Nordrehaug JE, Svardal A, Skorve J, Nygård O. Tetradecylthiopropionic acid induces hepatic mitochondrial dysfunction and steatosis, accompanied by increased plasma homocysteine in mice. Lipids Health Dis 2016; 15:24. [PMID: 26846427 PMCID: PMC4743328 DOI: 10.1186/s12944-016-0192-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 01/27/2016] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Hepatic mitochondrial dysfunction plays an important role in the pathogenesis of non-alcoholic fatty liver disease (NAFLD). Methyl donor supplementation has been shown to alleviate NAFLD, connecting the condition to the one-carbon metabolism. Thus, the objective was to investigate regulation of homocysteine (Hcy) and metabolites along the choline oxidation pathway during induction of hepatic steatosis by the fatty acid analogue tetradecylthiopropionic acid (TTP), an inhibitor of mitochondrial fatty acid oxidation. METHODS Mice were fed a control diet, or diets containing 0.3 %, 0.6 %, or 0.9 % (w/w) TTP for 14 days. Blood and liver samples were collected, enzyme activities and gene expression were analyzed in liver, lipid and fatty acid composition in liver and plasma, one-carbon metabolites, B-vitamin status, carnitine and acylcarnitines were analyzed in plasma. RESULTS Liver mitochondrial fatty acid oxidation decreased by 40 % and steatosis was induced in a dose dependent manner; total lipids increased 1.6-fold in animals treated with 0.3 % TTP, 2-fold with 0.6 % TTP and 2.1 fold with 0.9 % TTP compared to control. The higher hepatic concentration of fatty acids was associated with shortening of carbon-length. Furthermore, the inhibited fatty acid oxidation led to a 30-fold decrease in plasma carnitine and 9.3-fold decrease in acetylcarnitine at the highest dose of TTP, whereas an accumulation of palmitoylcarnitine resulted. Compared to the control diet, TTP administration was associated with elevated plasma total Hcy (control: 7.2 ± 0.3 umol/L, 0.9 % TTP: 30.5 ± 5.9 umol/L) and 1.4-1.6 fold increase in the one-carbon metabolites betaine, dimethylglycine, sarcosine and glycine, accompanied by changes in gene expression of the different B-vitamin dependent pathways of Hcy and choline metabolism. A positive correlation between total Hcy and hepatic triacylglycerol resulted. CONCLUSIONS The TTP-induced inhibition of mitochondrial fatty acid oxidation was not associated with increased hepatic oxidative stress or inflammation. Our data suggest a link between mitochondrial dysfunction and the methylation processes within the one-carbon metabolism in mice.
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Affiliation(s)
- Rolf K Berge
- Department of Clinical Science, University of Bergen, 5020, Bergen, Norway. .,Department of Heart Disease, Haukeland University Hospital, 5021, Bergen, Norway.
| | - Bodil Bjørndal
- Department of Clinical Science, University of Bergen, 5020, Bergen, Norway.
| | - Elin Strand
- Department of Clinical Science, University of Bergen, 5020, Bergen, Norway.
| | - Pavol Bohov
- Department of Clinical Science, University of Bergen, 5020, Bergen, Norway.
| | - Carine Lindquist
- Department of Clinical Science, University of Bergen, 5020, Bergen, Norway.
| | - Jan Erik Nordrehaug
- Department of Clinical Science, University of Bergen, 5020, Bergen, Norway. .,Department of Heart Disease, Stavanger University Hospital, 4142, Stavanger, Norway.
| | - Asbjørn Svardal
- Department of Clinical Science, University of Bergen, 5020, Bergen, Norway.
| | - Jon Skorve
- Department of Clinical Science, University of Bergen, 5020, Bergen, Norway.
| | - Ottar Nygård
- Department of Clinical Science, University of Bergen, 5020, Bergen, Norway. .,Department of Heart Disease, Haukeland University Hospital, 5021, Bergen, Norway. .,KG Jebsen Centre for Diabetes Research, University of Bergen, 5020, Bergen, Norway.
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Gudbrandsen OA, Wergedahl H, Bohov P, Berge RK. The absorption, distribution and biological effects of a modified fatty acid in its free form and as an ethyl ester in rats. Chem Biol Interact 2009; 179:227-32. [DOI: 10.1016/j.cbi.2008.10.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2008] [Revised: 09/30/2008] [Accepted: 10/01/2008] [Indexed: 11/15/2022]
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Carballeira NM, O'Neill R, Parang K. Synthesis and antifungal properties of alpha-methoxy and alpha-hydroxyl substituted 4-thiatetradecanoic acids. Chem Phys Lipids 2007; 150:82-8. [PMID: 17662704 PMCID: PMC2078680 DOI: 10.1016/j.chemphyslip.2007.06.218] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2007] [Revised: 06/18/2007] [Accepted: 06/19/2007] [Indexed: 10/23/2022]
Abstract
4-thiatetradecanoic acid exhibited weak antifungal activities against Candida albicans (ATCC 60193), Cryptococcus neoformans (ATCC 66031), and Aspergillus niger (ATCC 16404) (MIC=4.8-12.7 mM). It has been demonstrated that alpha-methoxylation efficiently blocks beta-oxidation and significantly improve the antifungal activities of fatty acids. We examined whether antifungal activity of 4-thiatetradecanoic acid can be improved by alpha-substitution. The unprecedented (+/-)-2-hydroxy-4-thiatetradecanoic acid was synthesized in four steps (20% overall yield), while the (+/-)-2-methoxy-4-thiatetradecanoic acid was synthesized in five steps (14% overall yield) starting from 1-decanethiol. The key step in the synthesis was the hydrolysis of a trimethylsilyloxynitrile. In general, the novel (+/-)-2-methoxy-4-thiatetradecanoic acid displayed significantly higher antifungal activities against C. albicans (ATCC 60193), C. neoformans (ATCC 66031), and A. niger (ATCC 16404) (MIC=0.8-1.2 mM), when compared with 4-thiatetradecanoic acid. In the case of C. neoformans the (+/-)-2-hydroxy-4-thiatetradecanoic acid was more fungitoxic (MIC=0.17 mM) than the alpha-methoxylated analog, but not as effective against A. niger (MIC=5.5 mM). The enhanced fungitoxicity of the (+/-)-2-methoxy-4-thiatetradecanoic acid, as compared to decylthiopropionic acid, might be the result of a longer half-life in the cells due to a blocked beta-oxidation pathway which results in more time to exert its toxic effects. Thus, these novel fatty acids may have applications as probes to study fatty acid metabolic routes in human cells.
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Affiliation(s)
- Néstor M Carballeira
- Department of Chemistry, University of Puerto Rico, P.O. Box 23346, San Juan 00931-3346, Puerto Rico.
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Gudbrandsen OA, Rost TH, Berge RK. Causes and prevention of tamoxifen-induced accumulation of triacylglycerol in rat liver. J Lipid Res 2006; 47:2223-32. [PMID: 16864897 DOI: 10.1194/jlr.m600148-jlr200] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Tamoxifen can induce hepatic steatosis in women. In this study, we wanted to elucidate the mechanism behind the tamoxifen-induced accumulation of triacylglycerol in liver in female rats, and we hoped to prevent this development by combination treatment with the modified fatty acid tetradecylthioacetic acid (TTA). The increased hepatic triacylglycerol level after tamoxifen treatment was accompanied by decreased acetyl-coenzyme A carboxylase (ACC) and FAS activities, increased glycerol-3-phosphate acyltransferase (GPAT) activity, and a tendency to increased diacylglycerol acyltransferase (DGAT) activity. The activities and mRNA levels of enzymes involved in beta-oxidation, ketogenesis, and uptake of lipids from liver were unaffected by tamoxifen, whereas the uptake of lipoproteins was unchanged and the uptake of fatty acids was decreased. Combination treatment with tamoxifen and TTA (Tam+TTA) normalized the hepatic triacylglycerol level and increased the activities of ACC, FAS, GPAT, and DGAT compared with tamoxifen-treated rats. The activities and mRNA levels of enzymes involved in beta-oxidation, ketogenesis, and uptake of lipids were increased after Tam+TTA treatment. In conclusion, tamoxifen increased the hepatic triacylglycerol level, probably as a result of increased triacylglycerol biosynthesis combined with unchanged beta-oxidation. The tamoxifen-induced accumulation of triacylglycerol was prevented by cotreatment with TTA, through mechanisms of increased mitochondrial and peroxisomal beta-oxidation.
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Affiliation(s)
- Oddrun Anita Gudbrandsen
- Institute of Medicine, Section of Medical Biochemistry, University of Bergen, Haukeland University Hospital, N-5021 Bergen, Norway.
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