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Zhao Y, Zhou Y, Wang D, Huang Z, Xiao X, Zheng Q, Li S, Long D, Feng L. Mitochondrial Dysfunction in Metabolic Dysfunction Fatty Liver Disease (MAFLD). Int J Mol Sci 2023; 24:17514. [PMID: 38139341 PMCID: PMC10743953 DOI: 10.3390/ijms242417514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Revised: 12/06/2023] [Accepted: 12/08/2023] [Indexed: 12/24/2023] Open
Abstract
Nonalcoholic fatty liver disease (NAFLD) has become an increasingly common disease in Western countries and has become the major cause of liver cirrhosis or hepatocellular carcinoma (HCC) in addition to viral hepatitis in recent decades. Furthermore, studies have shown that NAFLD is inextricably linked to the development of extrahepatic diseases. However, there is currently no effective treatment to cure NAFLD. In addition, in 2020, NAFLD was renamed metabolic dysfunction fatty liver disease (MAFLD) to show that its pathogenesis is closely related to metabolic disorders. Recent studies have reported that the development of MAFLD is inextricably associated with mitochondrial dysfunction in hepatocytes and hepatic stellate cells (HSCs). Simultaneously, mitochondrial stress caused by structural and functional disorders stimulates the occurrence and accumulation of fat and lipo-toxicity in hepatocytes and HSCs. In addition, the interaction between mitochondrial dysfunction and the liver-gut axis has also become a new point during the development of MAFLD. In this review, we summarize the effects of several potential treatment strategies for MAFLD, including antioxidants, reagents, and intestinal microorganisms and metabolites.
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Affiliation(s)
- Ying Zhao
- Division of Liver Surgery, Department of General Surgery, West China Hospital, Sichuan University, Chengdu 610041, China; (Y.Z.); (Y.Z.); (D.W.); (Z.H.); (X.X.); (Q.Z.); (S.L.); (D.L.)
- Regeneration Medicine Research Center, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Yanni Zhou
- Division of Liver Surgery, Department of General Surgery, West China Hospital, Sichuan University, Chengdu 610041, China; (Y.Z.); (Y.Z.); (D.W.); (Z.H.); (X.X.); (Q.Z.); (S.L.); (D.L.)
- Regeneration Medicine Research Center, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Dan Wang
- Division of Liver Surgery, Department of General Surgery, West China Hospital, Sichuan University, Chengdu 610041, China; (Y.Z.); (Y.Z.); (D.W.); (Z.H.); (X.X.); (Q.Z.); (S.L.); (D.L.)
- Regeneration Medicine Research Center, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Ziwei Huang
- Division of Liver Surgery, Department of General Surgery, West China Hospital, Sichuan University, Chengdu 610041, China; (Y.Z.); (Y.Z.); (D.W.); (Z.H.); (X.X.); (Q.Z.); (S.L.); (D.L.)
- Regeneration Medicine Research Center, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Xiong Xiao
- Division of Liver Surgery, Department of General Surgery, West China Hospital, Sichuan University, Chengdu 610041, China; (Y.Z.); (Y.Z.); (D.W.); (Z.H.); (X.X.); (Q.Z.); (S.L.); (D.L.)
- Regeneration Medicine Research Center, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Qing Zheng
- Division of Liver Surgery, Department of General Surgery, West China Hospital, Sichuan University, Chengdu 610041, China; (Y.Z.); (Y.Z.); (D.W.); (Z.H.); (X.X.); (Q.Z.); (S.L.); (D.L.)
- Regeneration Medicine Research Center, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Shengfu Li
- Division of Liver Surgery, Department of General Surgery, West China Hospital, Sichuan University, Chengdu 610041, China; (Y.Z.); (Y.Z.); (D.W.); (Z.H.); (X.X.); (Q.Z.); (S.L.); (D.L.)
- NHC Key Laboratory of Transplant Engineering and Immunology, West China Hospital Sichuan University, Chengdu 610041, China
| | - Dan Long
- Division of Liver Surgery, Department of General Surgery, West China Hospital, Sichuan University, Chengdu 610041, China; (Y.Z.); (Y.Z.); (D.W.); (Z.H.); (X.X.); (Q.Z.); (S.L.); (D.L.)
- NHC Key Laboratory of Transplant Engineering and Immunology, West China Hospital Sichuan University, Chengdu 610041, China
| | - Li Feng
- Division of Liver Surgery, Department of General Surgery, West China Hospital, Sichuan University, Chengdu 610041, China; (Y.Z.); (Y.Z.); (D.W.); (Z.H.); (X.X.); (Q.Z.); (S.L.); (D.L.)
- Regeneration Medicine Research Center, West China Hospital, Sichuan University, Chengdu 610041, China
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The Association between Non-Alcoholic Fatty Liver Disease (NAFLD) and Advanced Fibrosis with Serological Vitamin B12 Markers: Results from the NHANES 1999-2004. Nutrients 2022; 14:nu14061224. [PMID: 35334881 PMCID: PMC8948655 DOI: 10.3390/nu14061224] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 03/08/2022] [Accepted: 03/09/2022] [Indexed: 01/31/2023] Open
Abstract
Background: There is evidence that vitamin B12 and associated metabolite levels are changed in non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH); however, their association has been in dispute. Methods: We included 8397 individuals without previous liver condition or excess alcohol intake from the National Health and Nutrition Examination Survey (NHANES) 1999–2004. NAFLD was diagnosed with Fatty Liver Index (FLI) ≥ 60 or USFLI ≥ 30, and participants with advanced fibrosis risks were identified with elevated non-alcoholic fatty liver disease fibrosis score (NFS), fibrosis 4 index (FIB-4), or aspartate aminotransferase (AST)/platelet ratio index (APRI). Step-wide logistic regression adjusting for confounders was used to detect the association between NAFLD or advanced fibrosis with serum vitamin B12, folate, red blood cell folate (RBC folate), homocysteine (HCY), and methylmalonic acid (MMA). Results: The weighted prevalence of NAFLD was 44.2%. Compared with non-NAFLD participants, patients with NAFLD showed significantly increased RBC folate level and RBC counts, decreased serum vitamin B12 and folate, and similar HCY and MMA levels. NAFLD with advanced fibrosis risk had higher MMA and HCY, reduced serum vitamin B12, and similar serum folate and RBC folate levels than NAFLD with low fibrosis risk. Only RBC folate was independently associated with an increased risk of NAFLD (OR (95% CI): 2.24 (1.58, 3.18)). In all participants, MMA (OR: 1.41 (1.10, 1.80)) and HCY (OR: 2.76 (1.49, 5.11)) were independently associated with increased risk for advanced fibrosis. In participants with NAFLD, this independent association still existed (OR: 1.39 (1.04, 1.85) for MMA and 1.95 (1.09, 3.46) for HCY). In all participants, the area under the receiver operating characteristic curve (ROC AUC) on fibrosis was 0.6829 (0.6828, 0.6831) for MMA and 0.7319 (0.7318, 0.7320) for HCY; in participants with NAFLD, the corresponding ROC AUC was 0.6819 (0.6817, 0.6821) for MMA and 0.6926 (0.6925, 0.6928) for HCY. Conclusion: Among vitamin B12-associated biomarkers, RBC folate was independently associated with elevated NAFLD risk, whereas MMA and HCY were associated with increased risk for advanced fibrosis in the total population and NAFLD participants. Our study highlighted the clinical diagnostic value of vitamin B12 metabolites and the possibility that vitamin B12 metabolism could be a therapeutic target for NASH. Further studies using recent perspective data with biopsy proven NASH could be conducted to validate our results.
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Masetto Antunes M, Godoy G, Curi R, Vergílio Visentainer J, Barbosa Bazotte R. The Myristic Acid:Docosahexaenoic Acid Ratio Versus the n-6 Polyunsaturated Fatty Acid:n-3 Polyunsaturated Fatty Acid Ratio as Nonalcoholic Fatty Liver Disease Biomarkers. Metab Syndr Relat Disord 2021; 20:69-78. [PMID: 34813379 DOI: 10.1089/met.2021.0107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
It is well established that diets containing an increased omega-6 polyunsaturated fatty acid (n-6 PUFA) to omega-3 polyunsaturated fatty acid (n-3 PUFA) ratios are linked to inflammation and chronic diseases such as nonalcoholic fatty liver disease (NAFLD). However, the influence of an elevated n-6 PUFA:n-3 PUFA ratio in the tissues requires clarification. Herein, we identified primary experimental and clinical studies where it is possible to compare the performance of the myristic acid (Myr):docosahexaenoic acid (DHA) and n-6 PUFA:n-3 PUFA ratios in the liver and/or serum as potential NAFLD biomarkers. Articles were included if quantitative values of n-6 PUFA, n-3 PUFA, Myr, DHA, and information about liver inflammation or liver disease progression parameters were provided. Overall, most experimental (91.6%) and clinical studies (87.5%) reported higher Myr:DHA ratios associated with inflammation and/or NAFLD progression than the n-6 PUFA:n-3 PUFA ratio. We conclude that the Myr:DHA ratio represents a better biomarker of NAFLD than the n-6 PUFA:n-3 PUFA ratio. Future studies are necessary for verifying this observation.
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Affiliation(s)
- Marina Masetto Antunes
- Post-Graduation Program in Pharmaceutical Sciences, State University of Maringá, Maringá, Brazil
| | - Guilherme Godoy
- Post-Graduation Program in Pharmaceutical Sciences, State University of Maringá, Maringá, Brazil
| | - Rui Curi
- Interdisciplinary Post-Graduate Program in Health Sciences, Cruzeiro do Sul University, São Paulo, Brazil
| | | | - Roberto Barbosa Bazotte
- Post-Graduation Program in Pharmaceutical Sciences, State University of Maringá, Maringá, Brazil.,Department of Pharmacology and Therapeutics, State University of Maringá, Maringá, Brazil
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Brütting C, Hildebrand P, Brandsch C, Stangl GI. Ability of dietary factors to affect homocysteine levels in mice: a review. Nutr Metab (Lond) 2021; 18:68. [PMID: 34193183 PMCID: PMC8243555 DOI: 10.1186/s12986-021-00594-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Accepted: 06/14/2021] [Indexed: 01/10/2023] Open
Abstract
Homocysteine is associated with several diseases, and a series of dietary factors are known to modulate homocysteine levels. As mice are often used as model organisms to study the effects of dietary hyperhomocysteinemia, we collected data about concentrations of vitamin B12, vitamin B6, folate, methionine, cystine, and choline in mouse diets and the associated plasma/serum homocysteine levels. In addition, we more closely examined the composition of the control diet, the impact of the mouse strain, sex and age, and the duration of the dietary intervention on homocysteine levels. In total, 113 out of 1103 reviewed articles met the inclusion criteria. In the experimental and control diets, homocysteine levels varied from 0.1 to 280 µmol/l. We found negative correlations between dietary vitamin B12 (rho = − 0.125; p < 0.05), vitamin B6 (rho = − 0.191; p < 0.01) and folate (rho = − 0.395; p < 0.001) and circulating levels of homocysteine. In contrast, a positive correlation was observed between dietary methionine and homocysteine (methionine: rho = 0.146; p < 0.05). No significant correlations were found for cystine or choline and homocysteine levels. In addition, there was no correlation between the duration of the experimental diets and homocysteine levels. More importantly, the data showed that homocysteine levels varied widely in mice fed control diets as well. When comparing control diets with similar nutrient concentrations (AIN-based), there were significant differences in homocysteine levels caused by the strain (ANOVA, p < 0.05) and age of the mice at baseline (r = 0.47; p < 0.05). When comparing homocysteine levels and sex, female mice tended to have higher homocysteine levels than male mice (9.3 ± 5.9 µmol/l vs. 5.8 ± 4.5 µmol/l; p = 0.069). To conclude, diets low in vitamin B12, vitamin B6, or folate and rich in methionine are similarly effective in increasing homocysteine levels. AIN recommendations for control diets are adequate with respect to the amounts of homocysteine-modulating dietary parameters. In addition, the mouse strain and the age of mice can affect the homocysteine level.
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Affiliation(s)
- Christine Brütting
- Institute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, Von-Danckelmann-Platz 2, 06120, Halle (Saale), Germany.
| | - Pia Hildebrand
- Institute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, Von-Danckelmann-Platz 2, 06120, Halle (Saale), Germany
| | - Corinna Brandsch
- Institute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, Von-Danckelmann-Platz 2, 06120, Halle (Saale), Germany
| | - Gabriele I Stangl
- Institute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, Von-Danckelmann-Platz 2, 06120, Halle (Saale), Germany
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Peng H, Xu H, Wu J, Li J, Zhou Y, Ding Z, Siwko SK, Yuan X, Schalinske KL, Alpini G, Zhang KK, Xie L. Maternal high-fat diet disrupted one-carbon metabolism in offspring, contributing to nonalcoholic fatty liver disease. Liver Int 2021; 41:1305-1319. [PMID: 33529448 PMCID: PMC8137550 DOI: 10.1111/liv.14811] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 01/12/2021] [Accepted: 01/28/2021] [Indexed: 12/21/2022]
Abstract
BACKGROUND & AIMS Pregnant women may transmit their metabolic phenotypes to their offspring, enhancing the risk for nonalcoholic fatty liver disease (NAFLD); however, the molecular mechanisms remain unclear. METHODS Prior to pregnancy female mice were fed either a maternal normal-fat diet (NF-group, "no effectors"), or a maternal high-fat diet (HF-group, "persistent effectors"), or were transitioned from a HF to a NF diet before pregnancy (H9N-group, "effectors removal"), followed by pregnancy and lactation, and then offspring were fed high-fat diets after weaning. Offspring livers were analysed by functional studies, as well as next-generation sequencing for gene expression profiles and DNA methylation changes. RESULTS The HF, but not the H9N offspring, displayed glucose intolerance and hepatic steatosis. The HF offspring also displayed a disruption of lipid homeostasis associated with an altered methionine cycle and abnormal one-carbon metabolism that caused DNA hypermethylation and L-carnitine depletion associated with deactivated AMPK signalling and decreased expression of PPAR-α and genes for fatty acid oxidation. These changes were not present in H9N offspring. In addition, we identified maternal HF diet-induced genes involved in one-carbon metabolism that were associated with DNA methylation modifications in HF offspring. Importantly, the DNA methylation modifications and their associated gene expression changes were reversed in H9N offspring livers. CONCLUSIONS Our results demonstrate for the first time that maternal HF diet disrupted the methionine cycle and one-carbon metabolism in offspring livers which further altered lipid homeostasis. CpG islands of specific genes involved in one-carbon metabolism modified by different maternal diets were identified.
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Affiliation(s)
- Hui Peng
- Department of Nutrition, Texas A&M University, College Station, TX,Tongji Hospital, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Huiting Xu
- Department of Pathology, University of North Dakota, Grand Forks, North Dakota,Hubei Cancer Hospital, Wuhan, Hubei, China
| | - Jie Wu
- Institute of Biosciences & Technology, Texas A&M University, Houston, TX
| | - Jiangyuan Li
- Department of Nutrition, Texas A&M University, College Station, TX,Department of Statistics, Texas A&M University, College Station, TX
| | - Yi Zhou
- Department of Nutrition, Texas A&M University, College Station, TX,Tongji Hospital, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Zehuan Ding
- Department of Nutrition, Texas A&M University, College Station, TX
| | - Stefan K. Siwko
- Institute of Biosciences & Technology, Texas A&M University, Houston, TX
| | - Xianglin Yuan
- Tongji Hospital, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Kevin L. Schalinske
- Department of Food Science and Human Nutrition, Iowa State University, Ames, IA
| | - Gianfranco Alpini
- Richard L. Roudebush VA Medical Center, and Division of Gastroenterology and Hepatology, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN 46202
| | - Ke K. Zhang
- Department of Nutrition, Texas A&M University, College Station, TX,Institute of Biosciences & Technology, Texas A&M University, Houston, TX,Department of Pathology, University of North Dakota, Grand Forks, North Dakota,Co-corresponding author: These authors contributed equally to this work
| | - Linglin Xie
- Department of Nutrition, Texas A&M University, College Station, TX,Co-corresponding author: These authors contributed equally to this work
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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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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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