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Nittoli V, Colella M, Porciello A, Reale C, Roberto L, Russo F, Russo NA, Porreca I, De Felice M, Mallardo M, Ambrosino C. Multi Species Analyses Reveal Testicular T3 Metabolism and Signalling as a Target of Environmental Pesticides. Cells 2021; 10:2187. [PMID: 34571837 PMCID: PMC8471965 DOI: 10.3390/cells10092187] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 08/20/2021] [Accepted: 08/22/2021] [Indexed: 12/30/2022] Open
Abstract
Thyroid hormones (THs) regulate many biological processes in vertebrates, including reproduction. Testicular somatic and germ cells are equipped with the arrays of enzymes (deiodinases), transporters, and receptors necessary to locally maintain the optimal level of THs and their signalling, needed for their functions and spermatogenesis. Pesticides, as chlorpyrifos (CPF) and ethylene thiourea (ETU), impair the function of thyroid and testis, affecting male fertility. However, their ability to disarrange testicular T3 (t-T3) metabolism and signalling is poorly considered. Here, a multi-species analysis involving zebrafish and mouse suggests the damage of t-T3 metabolism and signalling as a mechanism of gonadic toxicity of low-doses CPF and ETU. Indeed, the developmental exposure to both compounds reduces Dio2 transcript in both models, as well as in ex-vivo cultures of murine seminiferous tubules, and it is linked to alteration of steroidogenesis and germ cell differentiation. A major impact on spermatogonia was confirmed molecularly by the expression of their markers and morphologically evidenced in zebrafish. The results reveal that in the adopted models, exposure to both pesticides alters the t-T3 metabolism and signalling, affecting the reproductive capability. Our data, together with previous reports suggest zebrafish as an evaluable model in assessing the action of compounds impairing locally T3 signalling.
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Affiliation(s)
- Valeria Nittoli
- Biogem, Istituto di Biologia e Genetica Molecolare, Via Camporeale, 83031 Ariano Irpino (AV), Italy; (V.N.); (M.C.); (A.P.); (C.R.); (L.R.); (F.R.); (N.A.R.); (I.P.)
| | - Marco Colella
- Biogem, Istituto di Biologia e Genetica Molecolare, Via Camporeale, 83031 Ariano Irpino (AV), Italy; (V.N.); (M.C.); (A.P.); (C.R.); (L.R.); (F.R.); (N.A.R.); (I.P.)
- Department of Science and Technology, University of Sannio, 82100 Benevento, Italy
- Laboratory of Pre-Clinical and Translational Research, IRCCS, Referral Cancer Center of Basilicata, 85028 Potenza, Italy
| | - Alfonsina Porciello
- Biogem, Istituto di Biologia e Genetica Molecolare, Via Camporeale, 83031 Ariano Irpino (AV), Italy; (V.N.); (M.C.); (A.P.); (C.R.); (L.R.); (F.R.); (N.A.R.); (I.P.)
| | - Carla Reale
- Biogem, Istituto di Biologia e Genetica Molecolare, Via Camporeale, 83031 Ariano Irpino (AV), Italy; (V.N.); (M.C.); (A.P.); (C.R.); (L.R.); (F.R.); (N.A.R.); (I.P.)
| | - Luca Roberto
- Biogem, Istituto di Biologia e Genetica Molecolare, Via Camporeale, 83031 Ariano Irpino (AV), Italy; (V.N.); (M.C.); (A.P.); (C.R.); (L.R.); (F.R.); (N.A.R.); (I.P.)
| | - Filomena Russo
- Biogem, Istituto di Biologia e Genetica Molecolare, Via Camporeale, 83031 Ariano Irpino (AV), Italy; (V.N.); (M.C.); (A.P.); (C.R.); (L.R.); (F.R.); (N.A.R.); (I.P.)
| | - Nicola A. Russo
- Biogem, Istituto di Biologia e Genetica Molecolare, Via Camporeale, 83031 Ariano Irpino (AV), Italy; (V.N.); (M.C.); (A.P.); (C.R.); (L.R.); (F.R.); (N.A.R.); (I.P.)
| | - Immacalata Porreca
- Biogem, Istituto di Biologia e Genetica Molecolare, Via Camporeale, 83031 Ariano Irpino (AV), Italy; (V.N.); (M.C.); (A.P.); (C.R.); (L.R.); (F.R.); (N.A.R.); (I.P.)
| | - Mario De Felice
- Department of Molecular Medicine and Medical Biotechnologies, University of Naples “Federico II”, 59100 Naples, Italy;
- IEOS-CNR, 80131 Naples, Italy
| | - Massimo Mallardo
- Department of Molecular Medicine and Medical Biotechnologies, University of Naples “Federico II”, 59100 Naples, Italy;
| | - Concetta Ambrosino
- Biogem, Istituto di Biologia e Genetica Molecolare, Via Camporeale, 83031 Ariano Irpino (AV), Italy; (V.N.); (M.C.); (A.P.); (C.R.); (L.R.); (F.R.); (N.A.R.); (I.P.)
- Department of Science and Technology, University of Sannio, 82100 Benevento, Italy
- IEOS-CNR, 80131 Naples, Italy
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Zander-Fox D, Villarosa L, McPherson NO. Albumin used in human IVF contain different levels of lipids and modify embryo and fetal growth in a mouse model. J Assist Reprod Genet 2021; 38:2371-2381. [PMID: 34114110 DOI: 10.1007/s10815-021-02255-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 06/03/2021] [Indexed: 11/25/2022] Open
Abstract
PURPOSE Different commercial human embryo culture mediums can alter embryo quality and change birthweight. One component that could be contributing to variations but is not widely investigated is human serum albumin (HSA). HSA plays a multitude of roles during embryo culture and is a carrier for molecules including lipids. It remains unclear if lipid composition of HSA varies among commercial products and its effects on embryo quality, implantation, and fetal outcomes are relatively unknown. METHODS Utilizing a mouse model of embryo culture, we cultured zygotes until the blastocyst stage (72-h culture) in G1/G2 containing either Vitrolife HSA, Sage HSA, or Recombinant HSA at 10%. Blastocyst quality (development, total cell number, superoxide generation), blastocyst lipid content (neutral lipids, non-esterified fatty acids, phospholipids, and triglycerides), implantation, and fetal lengths and weights were assessed. Fatty acid quantification of HSA source was assessed by standard thin-layer chromatography. RESULTS Sage HSA had the greatest fatty acid composition, with an eightfold increase in saturated fatty acids. This coincided with reduced blastocyst development, increased superoxide generation, neutral lipids and triglycerides levels of blastocysts, and decreased implantation rates (p < 0.05). Unexpectedly, while Recombinant HSA had the lowest overall lipids it had 70-fold increase in palmitoleic acid and the lowest fetal weights (p < 0.05). CONCLUSION Indicates the importance of a balance between different types/amount of lipids, and an "optimal ratio" required for embryo and fetal development. Therefore, the lipid content of HSA should be considered when choosing a suitable HSA source for use in clinical IVF.
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Affiliation(s)
- Deirdre Zander-Fox
- Repromed, Dulwich South Australia, Australia.
- Department of Bioengineering, University of South Australia, Adelaide, Australia.
- Monash University, Clayton, Australia.
- Monash IVF Group, Richmond, Victoria, Australia.
- Robinson Research Institute, University of Adelaide, Adelaide, South Australia, Australia.
- School of Medicine, University of Adelaide, Adelaide, Australia.
| | - Lauren Villarosa
- Repromed, Dulwich South Australia, Australia
- Robinson Research Institute, University of Adelaide, Adelaide, South Australia, Australia
| | - Nicole O McPherson
- Robinson Research Institute, University of Adelaide, Adelaide, South Australia, Australia
- School of Medicine, University of Adelaide, Adelaide, Australia
- Freemasons Center for Male Health and Wellbeing, University of Adelaide, Adelaide, South Australia, Australia
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Dallio M, Romeo M, Gravina AG, Masarone M, Larussa T, Abenavoli L, Persico M, Loguercio C, Federico A. Nutrigenomics and Nutrigenetics in Metabolic- (Dysfunction) Associated Fatty Liver Disease: Novel Insights and Future Perspectives. Nutrients 2021; 13:nu13051679. [PMID: 34063372 PMCID: PMC8156164 DOI: 10.3390/nu13051679] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 05/12/2021] [Accepted: 05/13/2021] [Indexed: 12/12/2022] Open
Abstract
Metabolic- (dysfunction) associated fatty liver disease (MAFLD) represents the predominant hepatopathy and one of the most important systemic, metabolic-related disorders all over the world associated with severe medical and socio-economic repercussions due to its growing prevalence, clinical course (steatohepatitis and/or hepatocellular-carcinoma), and related extra-hepatic comorbidities. To date, no specific medications for the treatment of this condition exist, and the most valid recommendation for patients remains lifestyle change. MAFLD has been associated with metabolic syndrome; its development and progression are widely influenced by the interplay between genetic, environmental, and nutritional factors. Nutrigenetics and nutrigenomics findings suggest nutrition’s capability, by acting on the individual genetic background and modifying the specific epigenetic expression as well, to influence patients’ clinical outcome. Besides, immunity response is emerging as pivotal in this multifactorial scenario, suggesting the interaction between diet, genetics, and immunity as another tangled network that needs to be explored. The present review describes the genetic background contribution to MAFLD onset and worsening, its possibility to be influenced by nutritional habits, and the interplay between nutrients and immunity as one of the most promising research fields of the future in this context.
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Affiliation(s)
- Marcello Dallio
- Department of Precision Medicine, University of Campania Luigi Vanvitelli, Via S. Pansini 5, 80131 Naples, Italy; (M.R.); (A.G.G.); (C.L.); (A.F.)
- Correspondence: ; Tel.: +39-0815666740
| | - Mario Romeo
- Department of Precision Medicine, University of Campania Luigi Vanvitelli, Via S. Pansini 5, 80131 Naples, Italy; (M.R.); (A.G.G.); (C.L.); (A.F.)
| | - Antonietta Gerarda Gravina
- Department of Precision Medicine, University of Campania Luigi Vanvitelli, Via S. Pansini 5, 80131 Naples, Italy; (M.R.); (A.G.G.); (C.L.); (A.F.)
| | - Mario Masarone
- Department of Medicine and Surgery, University of Salerno, Via Allende, 84081 Baronissi, Italy; (M.M.); (M.P.)
| | - Tiziana Larussa
- Department of Health Sciences, University Magna Graecia, viale Europa, 88100 Catanzaro, Italy; (T.L.); (L.A.)
| | - Ludovico Abenavoli
- Department of Health Sciences, University Magna Graecia, viale Europa, 88100 Catanzaro, Italy; (T.L.); (L.A.)
| | - Marcello Persico
- Department of Medicine and Surgery, University of Salerno, Via Allende, 84081 Baronissi, Italy; (M.M.); (M.P.)
| | - Carmelina Loguercio
- Department of Precision Medicine, University of Campania Luigi Vanvitelli, Via S. Pansini 5, 80131 Naples, Italy; (M.R.); (A.G.G.); (C.L.); (A.F.)
| | - Alessandro Federico
- Department of Precision Medicine, University of Campania Luigi Vanvitelli, Via S. Pansini 5, 80131 Naples, Italy; (M.R.); (A.G.G.); (C.L.); (A.F.)
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Romano A, Friuli M, Del Coco L, Longo S, Vergara D, Del Boccio P, Valentinuzzi S, Cicalini I, Fanizzi FP, Gaetani S, Giudetti AM. Chronic Oleoylethanolamide Treatment Decreases Hepatic Triacylglycerol Level in Rat Liver by a PPARγ/SREBP-Mediated Suppression of Fatty Acid and Triacylglycerol Synthesis. Nutrients 2021; 13:394. [PMID: 33513874 PMCID: PMC7910994 DOI: 10.3390/nu13020394] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 01/18/2021] [Accepted: 01/23/2021] [Indexed: 12/14/2022] Open
Abstract
Oleoylethanolamide (OEA) is a naturally occurring bioactive lipid belonging to the family of N-acylethanolamides. A variety of beneficial effects have been attributed to OEA, although the greater interest is due to its potential role in the treatment of obesity, fatty liver, and eating-related disorders. To better clarify the mechanism of the antiadipogenic effect of OEA in the liver, using a lipidomic study performed by 1H-NMR, LC-MS/MS and thin-layer chromatography analyses we evaluated the whole lipid composition of rat liver, following a two-week daily treatment of OEA (10 mg kg-1 i.p.). We found that OEA induced a significant reduction in hepatic triacylglycerol (TAG) content and significant changes in sphingolipid composition and ceramidase activity. We associated the antiadipogenic effect of OEA to decreased activity and expression of key enzymes involved in fatty acid and TAG syntheses, such as acetyl-CoA carboxylase, fatty acid synthase, diacylglycerol acyltransferase, and stearoyl-CoA desaturase 1. Moreover, we found that both SREBP-1 and PPARγ protein expression were significantly reduced in the liver of OEA-treated rats. Our findings add significant and important insights into the molecular mechanism of OEA on hepatic adipogenesis, and suggest a possible link between the OEA-induced changes in sphingolipid metabolism and suppression of hepatic TAG level.
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Affiliation(s)
- Adele Romano
- Department of Physiology and Pharmacology “V. Erspamer”, Sapienza University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy; (A.R.); (M.F.); (S.G.)
| | - Marzia Friuli
- Department of Physiology and Pharmacology “V. Erspamer”, Sapienza University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy; (A.R.); (M.F.); (S.G.)
| | - Laura Del Coco
- Department of Biological and Environmental Sciences and Technologies, University of Salento, Via Prov.le Lecce-Monteroni, 73100 Lecce, Italy; (L.D.C.); (S.L.); (D.V.)
| | - Serena Longo
- Department of Biological and Environmental Sciences and Technologies, University of Salento, Via Prov.le Lecce-Monteroni, 73100 Lecce, Italy; (L.D.C.); (S.L.); (D.V.)
| | - Daniele Vergara
- Department of Biological and Environmental Sciences and Technologies, University of Salento, Via Prov.le Lecce-Monteroni, 73100 Lecce, Italy; (L.D.C.); (S.L.); (D.V.)
| | - Piero Del Boccio
- Department of Pharmacy, University “G. d’Annunzio” of Chieti-Pescara, 66100 Chieti, Italy; (P.D.B.); (S.V.)
- Center for Advanced Studies and Technology (CAST), University “G. d’Annunzio” of Chieti-Pescara, 66100 Chieti, Italy;
| | - Silvia Valentinuzzi
- Department of Pharmacy, University “G. d’Annunzio” of Chieti-Pescara, 66100 Chieti, Italy; (P.D.B.); (S.V.)
- Center for Advanced Studies and Technology (CAST), University “G. d’Annunzio” of Chieti-Pescara, 66100 Chieti, Italy;
| | - Ilaria Cicalini
- Center for Advanced Studies and Technology (CAST), University “G. d’Annunzio” of Chieti-Pescara, 66100 Chieti, Italy;
- Department of Medicine and Aging Science, University “G. d’Annunzio” of Chieti-Pescara, 66100 Chieti, Italy
| | - Francesco P. Fanizzi
- Department of Biological and Environmental Sciences and Technologies, University of Salento, Via Prov.le Lecce-Monteroni, 73100 Lecce, Italy; (L.D.C.); (S.L.); (D.V.)
| | - Silvana Gaetani
- Department of Physiology and Pharmacology “V. Erspamer”, Sapienza University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy; (A.R.); (M.F.); (S.G.)
| | - Anna M. Giudetti
- Department of Biological and Environmental Sciences and Technologies, University of Salento, Via Prov.le Lecce-Monteroni, 73100 Lecce, Italy; (L.D.C.); (S.L.); (D.V.)
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Hishikawa D, Yanagida K, Nagata K, Kanatani A, Iizuka Y, Hamano F, Yasuda M, Okamura T, Shindou H, Shimizu T. Hepatic Levels of DHA-Containing Phospholipids Instruct SREBP1-Mediated Synthesis and Systemic Delivery of Polyunsaturated Fatty Acids. iScience 2020; 23:101495. [PMID: 32891885 PMCID: PMC7481256 DOI: 10.1016/j.isci.2020.101495] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 07/25/2020] [Accepted: 08/19/2020] [Indexed: 12/25/2022] Open
Abstract
Polyunsaturated fatty acids (PUFAs), such as docosahexaenoic acid (DHA) and arachidonic acid (ARA), play fundamental roles in mammalian physiology. Although PUFA imbalance causes various disorders, mechanisms of the regulation of their systemic levels are poorly understood. Here, we report that hepatic DHA-containing phospholipids (DHA-PLs) determine the systemic levels of PUFAs through the SREBP1-mediated transcriptional program. We demonstrated that liver-specific deletion of Agpat3 leads to a decrease of DHA-PLs and a compensatory increase of ARA-PLs not only in the liver but also in other tissues including the brain. Together with recent findings that plasma lysophosphatidylcholine (lysoPC) is the major source of brain DHA, our results indicate that hepatic AGPAT3 contributes to brain DHA accumulation by supplying DHA-PLs as precursors of DHA-lysoPC. Furthermore, dietary fish oil-mediated suppression of hepatic PUFA biosynthetic program was blunted in liver-specific Agpat3 deletion. Our findings highlight the central role of hepatic DHA-PLs as the molecular rheostat for systemic homeostasis of PUFAs.
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Affiliation(s)
- Daisuke Hishikawa
- Department of Lipid Signaling, National Center for Global Health and Medicine, Shinjuku-ku, Tokyo 162-8655, Japan.
| | - Keisuke Yanagida
- Department of Lipid Signaling, National Center for Global Health and Medicine, Shinjuku-ku, Tokyo 162-8655, Japan
| | - Katsuyuki Nagata
- Department of Lipid Signaling, National Center for Global Health and Medicine, Shinjuku-ku, Tokyo 162-8655, Japan
| | - Ayumi Kanatani
- Department of Lipid Signaling, National Center for Global Health and Medicine, Shinjuku-ku, Tokyo 162-8655, Japan
| | - Yoshiko Iizuka
- Department of Lipid Signaling, National Center for Global Health and Medicine, Shinjuku-ku, Tokyo 162-8655, Japan
| | - Fumie Hamano
- Department of Lipid Signaling, National Center for Global Health and Medicine, Shinjuku-ku, Tokyo 162-8655, Japan; Life Science Core Faculty, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Megumi Yasuda
- Department of Lipid Signaling, National Center for Global Health and Medicine, Shinjuku-ku, Tokyo 162-8655, Japan
| | - Tadashi Okamura
- Laboratory Animal Medicine, National Center for Global Health and Medicine, Shinjuku-ku, Tokyo 162-8655, Japan; Section of Animal Models, Department of Infectious Diseases, National Center for Global Health and Medicine, Shinjuku-ku, Tokyo 162-8655, Japan
| | - Hideo Shindou
- Department of Lipid Signaling, National Center for Global Health and Medicine, Shinjuku-ku, Tokyo 162-8655, Japan; Department of Lipid Science, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Takao Shimizu
- Department of Lipid Signaling, National Center for Global Health and Medicine, Shinjuku-ku, Tokyo 162-8655, Japan; Department of Lipidomics, Graduate School of Medicine, the University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan.
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Transcriptome analyses of liver in newly-hatched chicks during the metabolic perturbation of fasting and re-feeding reveals THRSPA as the key lipogenic transcription factor. BMC Genomics 2020; 21:109. [PMID: 32005146 PMCID: PMC6995218 DOI: 10.1186/s12864-020-6525-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 01/22/2020] [Indexed: 12/17/2022] Open
Abstract
Background The fasting-refeeding perturbation has been used extensively to reveal specific genes and metabolic pathways that control energy metabolism in the chicken. Most global transcriptional scans of the fasting-refeeding response in liver have focused on juvenile chickens that were 1, 2 or 4 weeks old. The present study was aimed at the immediate post-hatch period, in which newly-hatched chicks were subjected to fasting for 4, 24 or 48 h, then refed for 4, 24 or 48 h, and compared with a fully-fed control group at each age (D1-D4). Results Visual analysis of hepatic gene expression profiles using hierarchical and K-means clustering showed two distinct patterns, genes with higher expression during fasting and depressed expression upon refeeding and those with an opposing pattern of expression, which exhibit very low expression during fasting and more abundant expression with refeeding. Differentially-expressed genes (DEGs), identified from five prominent pair-wise contrasts of fed, fasted and refed conditions, were subjected to Ingenuity Pathway Analysis. This enabled mapping of analysis-ready (AR)-DEGs to canonical and metabolic pathways controlled by distinct gene interaction networks. The largest number of hepatic DEGs was identified by two contrasts: D2FED48h/D2FAST48h (968 genes) and D2FAST48h/D3REFED24h (1198 genes). The major genes acutely depressed by fasting and elevated upon refeeding included ANGTPL, ATPCL, DIO2, FASN, ME1, SCD, PPARG, SREBP2 and THRSPA—a primary lipogenic transcription factor. In contrast, major lipolytic genes were up-regulated by fasting or down-regulated after refeeding, including ALDOB, IL-15, LDHB, LPIN2, NFE2L2, NR3C1, NR0B1, PANK1, PPARA, SERTAD2 and UPP2. Conclusions Transcriptional profiling of liver during fasting/re-feeding of newly-hatched chicks revealed several highly-expressed upstream regulators, which enable the metabolic switch from fasted (lipolytic/gluconeogenic) to fed or refed (lipogenic/thermogenic) states. This rapid homeorhetic shift of whole-body metabolism from a catabolic-fasting state to an anabolic-fed state appears precisely orchestrated by a small number of ligand-activated transcription factors that provide either a fasting-lipolytic state (PPARA, NR3C1, NFE2L2, SERTAD2, FOX01, NR0B1, RXR) or a fully-fed and refed lipogenic/thermogenic state (THRSPA, SREBF2, PPARG, PPARD, JUN, ATF3, CTNNB1). THRSPA has emerged as the key transcriptional regulator that drives lipogenesis and thermogenesis in hatchling chicks, as shown here in fed and re-fed states.
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Oteng A, Loregger A, van Weeghel M, Zelcer N, Kersten S. Industrial Trans Fatty Acids Stimulate SREBP2-Mediated Cholesterogenesis and Promote Non-Alcoholic Fatty Liver Disease. Mol Nutr Food Res 2019; 63:e1900385. [PMID: 31327168 PMCID: PMC6790681 DOI: 10.1002/mnfr.201900385] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 07/01/2019] [Indexed: 12/24/2022]
Abstract
SCOPE The mechanisms underlying the deleterious effects of trans fatty acids on plasma cholesterol and non-alcoholic fatty liver disease (NAFLD) are unclear. Here, the aim is to investigate the molecular mechanisms of action of industrial trans fatty acids. METHODS AND RESULTS Hepa1-6 hepatoma cells were incubated with elaidate, oleate, or palmitate. C57Bl/6 mice were fed diets rich in trans-unsaturated, cis-unsaturated, or saturated fatty acids. Transcriptomics analysis of Hepa1-6 cells shows that elaidate but not oleate or palmitate induces expression of genes involved in cholesterol biosynthesis. Induction of cholesterogenesis by elaidate is mediated by increased sterol regulatory element-binding protein 2 (SREBP2) activity and is dependent on SREBP cleavage-activating protein (SCAP), yet independent of liver-X receptor and ubiquitin regulatory X domain-containing protein 8. Elaidate decreases intracellular free cholesterol levels and represses the anticholesterogenic effect of exogenous cholesterol. In mice, the trans-unsaturated diet increases the ratio of liver to gonadal fat mass, steatosis, hepatic cholesterol levels, alanine aminotransferase activity, and fibrosis markers, suggesting enhanced NAFLD, compared to the cis-unsaturated and saturated diets. CONCLUSION Elaidate induces cholesterogenesis in vitro by activating the SCAP-SREBP2 axis, likely by lowering intracellular free cholesterol and attenuating cholesterol-dependent repression of SCAP. This pathway potentially underlies the increase in liver cholesterol and NAFLD by industrial trans fatty acids.
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Affiliation(s)
- Antwi‐Boasiako Oteng
- Nutrition, Metabolism and Genomics GroupDivision of Human Nutrition and HealthWageningen University6708 WEWageningenThe Netherlands
| | - Anke Loregger
- Department of Medical BiochemistryAcademic Medical CenterUniversity of Amsterdam1105 AZAmsterdamThe Netherlands
| | - Michel van Weeghel
- Laboratory Genetic Metabolic DiseasesAmsterdam UMC, University of Amsterdam, Amsterdam Gastroenterology and Metabolism, Amsterdam Cardiovascular Sciences1105 AZAmsterdamThe Netherlands
| | - Noam Zelcer
- Department of Medical BiochemistryAcademic Medical CenterUniversity of Amsterdam1105 AZAmsterdamThe Netherlands
| | - Sander Kersten
- Nutrition, Metabolism and Genomics GroupDivision of Human Nutrition and HealthWageningen University6708 WEWageningenThe Netherlands
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miR-146a is involved in the regulation of vertebrate LC-PUFA biosynthesis by targeting elovl5 as demonstrated in rabbitfish Siganus canaliculatus. Gene 2018; 676:306-314. [DOI: 10.1016/j.gene.2018.08.063] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Revised: 08/13/2018] [Accepted: 08/21/2018] [Indexed: 01/26/2023]
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Yang D, Huynh H, Wan Y. Milk lipid regulation at the maternal-offspring interface. Semin Cell Dev Biol 2018; 81:141-148. [PMID: 29051053 PMCID: PMC5916746 DOI: 10.1016/j.semcdb.2017.10.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Accepted: 10/12/2017] [Indexed: 12/19/2022]
Abstract
Milk lipids provide a large proportion of energy, nutrients, essential fatty acids, and signaling molecules for the newborns, the synthesis of which is a tightly controlled process. Dysregulated milk lipid production and composition may be detrimental to the growth, development, health and survival of the newborns. Many genetically modified animal models have contributed to our understanding of milk lipid regulation in the lactating mammary gland. In this review, we discuss recent advances in our knowledge of the mechanisms that control milk lipid biosynthesis and secretion during lactation, and how maternal genetic and dietary defects impact milk lipid composition and consequently offspring traits.
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Affiliation(s)
- Dengbao Yang
- Department of Pharmacology, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - HoangDinh Huynh
- Department of Pharmacology, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Yihong Wan
- Department of Pharmacology, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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Nakajima T, Yang Y, Lu Y, Kamijo Y, Yamada Y, Nakamura K, Koyama M, Yamaguchi S, Sugiyama E, Tanaka N, Aoyama T. Decreased Fatty Acid β-Oxidation Is the Main Cause of Fatty Liver Induced by Polyunsaturated Fatty Acid Deficiency in Mice. TOHOKU J EXP MED 2018; 242:229-239. [PMID: 28724855 DOI: 10.1620/tjem.242.229] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Insufficient intake of polyunsaturated fatty acids (PUFA) causes fatty liver. The mechanism responsible is primarily related to increased lipogenesis and decreased FA degradation based on rodent studies. However, these studies were limited by the fact that the typical PUFA-deficient diets contained insufficient amounts of long-chain FA, the PUFA-containing diets were primarily composed of n-3 PUFA-enriched oil, and the intake of PUFA was excessive compared with the physiological requirement. To address these issues, mice were fed a PUFA-deficient diet containing long-chain FA at a standard fed level and then were orally fed a n-3/n-6-balanced PUFA-containing oil [PUFA (+)] or a PUFA-deficient oil [PUFA (-)] at physiological relevant levels (0.1 mL/mouse/2d). We compared these groups and examined whether fatty liver in PUFA deficiency was attributable to both the effects of increased lipogenesis and decreased FA catabolism. Compared with the PUFA (+) group, the PUFA (-) group showed increases in liver triglyceride and serum FA content. Hepatic gene expression of several mitochondrial β-oxidation enzymes, the serum 3-hydroxybutyrate level, and DNA-binding ability of peroxisome proliferator-activated receptor α (PPARα) were increased in the PUFA (+) group, whereas these adaptive responses were significantly attenuated in the PUFA (-) group. The hepatic expression of typical lipogenesis genes did not differ between the groups. Therefore, fatty liver in PUFA deficiency is attributable to suppression of the FA-degrading system probably from decreased PPARα adaptive responsiveness, and PUFA may be an essential factor for PPARα functioning. This finding is helpful for managing clinical situations having a risk of PUFA deficiency.
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Affiliation(s)
- Takero Nakajima
- Department of Metabolic Regulation, Shinshu University Graduate School of Medicine.,Research Center for Agricultural Food Industry, Shinshu University
| | - Yang Yang
- Department of Metabolic Regulation, Shinshu University Graduate School of Medicine.,Department of Cardiology, The Third Hospital of Hebei Medical University
| | - Yu Lu
- Department of Metabolic Regulation, Shinshu University Graduate School of Medicine
| | - Yuji Kamijo
- Department of Metabolic Regulation, Shinshu University Graduate School of Medicine.,Department of Nephrology, Shinshu University School of Medicine
| | - Yosuke Yamada
- Department of Metabolic Regulation, Shinshu University Graduate School of Medicine.,Department of Nephrology, Shinshu University School of Medicine
| | - Kozo Nakamura
- Research Center for Agricultural Food Industry, Shinshu University.,Department of Bioscience and Biotechnology, Faculty of Agriculture, Shinshu University
| | - Masahiro Koyama
- Department of Bioscience and Biotechnology, Faculty of Agriculture, Shinshu University
| | - Shohei Yamaguchi
- Department of Bioscience and Biotechnology, Faculty of Agriculture, Shinshu University
| | - Eiko Sugiyama
- Department of Nutritional Science, Nagano Prefectural College
| | - Naoki Tanaka
- Department of Metabolic Regulation, Shinshu University Graduate School of Medicine.,Research Center for Agricultural Food Industry, Shinshu University
| | - Toshifumi Aoyama
- Department of Metabolic Regulation, Shinshu University Graduate School of Medicine
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11
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Lei L, Chen J, Liu Y, Wang L, Zhao G, Chen ZY. Dietary Wheat Bran Oil Is Equally as Effective as Rice Bran Oil in Reducing Plasma Cholesterol. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2018; 66:2765-2774. [PMID: 29502409 DOI: 10.1021/acs.jafc.7b06093] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Rice bran oil (RBO) possesses a plasma cholesterol-lowering activity, while effect of wheat bran oil (WBO) on plasma cholesterol remains unknown. The present study compared the cholesterol-lowering activity of WBO with that of RBO in hamsters. Fifty-four male hamsters were divided into seven groups fed either a noncholesterol diet (NCD) or one of six high-cholesterol diets, namely HCD diet (0.2% cholesterol +9.5% lard), HCD+C diet (0.2% cholesterol +9.5% lard +0.5% cholestyramine), WL diet (0.2% cholesterol +4.8% Lard +4.8% WBO), WH diet (0.2% cholesterol +9.5% WBO), RL diet (0.2% cholesterol +4.8% Lard +4.8% RBO), and RH diet (0.2% cholesterol +9.5% RBO). Plasma total cholesterol (TC) in HCD group was 327.4 ± 31.8 mg/dL, while plasma TC in two WBO and two RBO groups was 242.2 ± 20.8, 243.1 ± 31.7, 257.1 ± 16.3, and 243.4 ± 46.0 mg/dL, respectively, leading to a decrease in plasma TC by 22-26% ( P < 0.01). No significant difference in cholesterol-lowering potency was seen between WBO and RBO. Plasma cholesterol-lowering activity of WBO and RBO was accompanied by down-regulation of hepatic 3-hydroxy-3-methylglutaryl-CoA reductase and fatty acid synthase, while up-regulation of cholesterol-7α-hydroxylase. WL, WH, RL, and RH diets increased the fecal excretion of total neutral sterols by 72.8%, 106.9%, 5.4%, and 36.8% ( P < 0.01) respectively. Results indicated WBO and RBO could inhibit cholesterol absorption via down-regulation of intestinal Niemann-Pick C1 like 1 protein, acyl CoA:cholesterol acyltransferase 2, and ATP binding cassette transporter 5. In summary, WBO was equally effective as RBO in decreasing plasma cholesterol in hypercholesterolemia hamsters.
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Affiliation(s)
- Lin Lei
- College of Food Science , Southwest University , Chongqing 400715 , China
- School of Life Sciences , The Chinese University of Hong Kong , Hong, Kong , China
| | - Jingnan Chen
- Provincial Key Laboratory for Transformation and Utilization of Cereal Resource , Henan University of Technology , Zhengzhou , Henan 450001 , China
| | - Yuwei Liu
- School of Public Health , Fudan University , Shanghai 200032 , China
| | - Lijun Wang
- Shenzhen Institute for Drug Control, Shenzhen , China
| | - Guohua Zhao
- College of Food Science , Southwest University , Chongqing 400715 , China
| | - Zhen-Yu Chen
- School of Life Sciences , The Chinese University of Hong Kong , Hong, Kong , China
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12
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Miyata M, Shinno K, Kinoshita T, Kinoshita Y, Sugiura Y. Fish oil feeding reverses hepatomegaly and disrupted hepatic function due to the lack of FXR signaling. J Toxicol Sci 2018; 42:671-681. [PMID: 29142166 DOI: 10.2131/jts.42.671] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Mice lacking farnesoid X receptor (FXR) are used as a model for nonalcoholic fatty liver disease because their livers exhibit hepatomegaly, hepatic steatosis, and hepatic inflammation. The influence of fish oil feeding on hepatomegaly and disrupted hepatic function was investigated using female Fxr-null mice and wild-type mice fed a fish oil diet (2% fish oil and 2% corn oil) or a control diet (4% corn oil) for 4 weeks. Hepatic n-3 polyunsaturated fatty acid (PUFA) levels, including 22:6 n-3 docosahexaenoic acid (DHA) and 20:5 n-3 eicosapentaenoic acid (EPA) were significantly higher in the fish oil group than those in the control group of Fxr-null mice and wild-type mice. Fxr-null mouse livers of the control group showed a whitish brown coloration, whereas Fxr-null mouse livers of the fish oil group showed a dark brown coloration similar to that of wild-type mice. The liver in Fxr-null mice of the fish oil group was smaller than that of the control group. There was a significant decrease in the levels of hepatic damage-associated diagnostic markers, hepatic and serum bile acids, triglycerides, free fatty acids, and total cholesterol levels in Fxr-null mice because of fish oil feeding. It also reversed elevated mRNA levels of oxidative stress-related genes (Hmox1, Gsta1, and Gsta2) and reduced mRNA levels of transcriptional factors (Pparα and Shp) in Fxr-null mice. These results suggest that fish oil feeding reverses hepatomegaly and disrupted hepatic function due to the lack of FXR signaling.
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Affiliation(s)
- Masaaki Miyata
- Department of Food Science and Technology, National Fisheries University
| | - Kouhei Shinno
- Department of Food Science and Technology, National Fisheries University
| | - Tomoki Kinoshita
- Department of Food Science and Technology, National Fisheries University
| | - Yuichi Kinoshita
- Department of Food Science and Technology, National Fisheries University
| | - Yoshimasa Sugiura
- Department of Food Science and Technology, National Fisheries University
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13
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Pédrono F, Boulier-Monthéan N, Boissel F, Ossemond J, Lohézic-Le Dévéhat F. The Hypotriglyceridemic Effect of Sciadonic Acid is Mediated by the Inhibition of Δ9-Desaturase Expression and Activity. Mol Nutr Food Res 2018; 62. [DOI: 10.1002/mnfr.201700567] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Revised: 11/21/2017] [Indexed: 11/10/2022]
Affiliation(s)
- Frédérique Pédrono
- Agrocampus Ouest; Rennes France
- UMR INRA 1253; Science et Technologie du Lait et de l’Œuf; équipe Bioactivité et Nutrition; Rennes France
| | - Nathalie Boulier-Monthéan
- Agrocampus Ouest; Rennes France
- UMR INRA 1253; Science et Technologie du Lait et de l’Œuf; équipe Bioactivité et Nutrition; Rennes France
| | - Françoise Boissel
- Agrocampus Ouest; Rennes France
- UMR INRA 1253; Science et Technologie du Lait et de l’Œuf; équipe Bioactivité et Nutrition; Rennes France
| | - Jordane Ossemond
- UMR INRA 1253; Science et Technologie du Lait et de l’Œuf; équipe Bioactivité et Nutrition; Rennes France
| | - Françoise Lohézic-Le Dévéhat
- UMR CNRS 6226; Institut des Sciences Chimiques de Rennes; équipe Produits Naturels; Synthèse et Chimie Médicinale; UFR Sciences Pharmaceutiques et Biologiques; Université de Rennes 1; Rennes France
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14
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Huang LH, Chung HY, Su HM. Docosahexaenoic acid reduces sterol regulatory element binding protein-1 and fatty acid synthase expression and inhibits cell proliferation by inhibiting pAkt signaling in a human breast cancer MCF-7 cell line. BMC Cancer 2017; 17:890. [PMID: 29282029 PMCID: PMC5745739 DOI: 10.1186/s12885-017-3936-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 12/19/2017] [Indexed: 12/02/2022] Open
Abstract
Background Fatty acid synthase (FASN), the major enzyme in de novo fatty acid synthesis, is highly expressed in breast cancer and its expression is reduced by polyunsaturated fatty acids (PUFAs) in liver. We previously found a positive association between rat mammary tumor levels of the n-6 PUFA arachidonic acid (AA) and tumor weight. We examined the roles of the major n-3 PUFA, docosahexaenoic acid (DHA, 22:6n-3), and the major n-6 PUFA, AA, in FASN expression in, and proliferation of, human breast cancer MCF-7 cells. Methods The cells were treated for 48 h with BSA or 60 μM BSA-bound DHA, AA, or oleic acid (OA, 18:1n-9), then were incubated with or without estradiol or insulin. Western blot and 3H–thymidine incorporation assay were used to determine the role of DHA on FASN regulation and MCF-7 cell proliferation. Results DHA, but neither AA nor OA, inhibits estradiol-induced and insulin-induced expression of the precursor of sterol regulatory element binding protein-1 (p-SREBP-1), its mature form (m-SREBP-1), and FASN. Estradiol or insulin stimulation increased the pAkt/Akt and pS6/S6 ratios, expression of p-SREBP-1, m-SREBP-1, and FASN, and cell proliferation, and these effects were decreased by DHA. The DHA-induced decrease in FASN expression resulted from reduced pAkt/Akt signaling and not pERK1/2/ERK1/2 signaling. In addition, DHA enhanced the inhibitory effect of LY294002 on pAkt signaling and expression of p-SREBP-1, m-SREBP-1, and FASN. However, addition of rapamycin, an inhibitor of the mTOR signaling pathways, 1 h before addition of estradiol or insulin increased the pAkt/Akt ratio and FASN expression, and this effect was inhibited by addition of DHA 48 h before rapamycin. Conclusion We conclude that, in MCF-7 cells, DHA inhibits pAKT signaling and thus expression of p-SREBP-1, m-SREBP-1, and FASN and cell proliferation.
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Affiliation(s)
- Li-Hsuan Huang
- Institute of Physiology, College of Medicine, National Taiwan University, 1 Sec 1 Jai-Ai Rd, Taipei, 100, Taiwan
| | - Hsin-Yun Chung
- Institute of Physiology, College of Medicine, National Taiwan University, 1 Sec 1 Jai-Ai Rd, Taipei, 100, Taiwan
| | - Hui-Min Su
- Institute of Physiology, College of Medicine, National Taiwan University, 1 Sec 1 Jai-Ai Rd, Taipei, 100, Taiwan.
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15
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Expression of Thyroid Hormone Responsive SPOT 14 Gene Is Regulated by Estrogen in Chicken (Gallus gallus). Sci Rep 2017; 7:10243. [PMID: 28860448 PMCID: PMC5579026 DOI: 10.1038/s41598-017-08452-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 07/12/2017] [Indexed: 12/04/2022] Open
Abstract
Thyroid hormone responsive spot 14 (THRSP) is a small nuclear protein that responds rapidly to thyroid hormone. It has been shown that THRSP is abundant in lipogenic tissues such as liver, fat and the mammary gland in mammals. The THRSP gene acts as a key lipogenic activator and can be activated by thyroid hormone triiodothyronine (T3), glucose, carbohydrate and insulin. Here we report that chicken THRSP is also abundant in lipogenic tissues including the liver and the abdominal fat, and its expression levels increased with sex maturation and reached the highest level at the peak of egg production. Structure analysis of the THRSP gene indicates that there is a conscious estrogen response element (ERE) located in the −2390 – −2402 range of the gene promoter region. Further studies by ChIP-qPCR proved that the ERα interacts with the putative ERE site. In addition, THRSP was significantly upregulated (P < 0.05) when chickens or chicken primary hepatocytes were treated with 17β-estradiol in both the in vivo and in vitro conditions. We therefore conclude that THRSP is directly regulated by estrogen and is involved in the estrogen regulation network in chicken.
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16
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Jump DB, Lytle KA, Depner CM, Tripathy S. Omega-3 polyunsaturated fatty acids as a treatment strategy for nonalcoholic fatty liver disease. Pharmacol Ther 2017; 181:108-125. [PMID: 28723414 DOI: 10.1016/j.pharmthera.2017.07.007] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Obese and type 2 diabetic (T2DM) patients have a high prevalence of nonalcoholic fatty liver disease (NAFLD). NAFLD is a continuum of chronic liver diseases ranging from benign hepatosteatosis to nonalcoholic steatohepatitis (NASH), cirrhosis and primary hepatocellular cancer (HCC). Because of its strong association with the obesity epidemic, NAFLD is rapidly becoming a major public health concern worldwide. Surprisingly, there are no FDA approved NAFLD therapies; and current therapies focus on the co-morbidities associated with NAFLD, namely, obesity, hyperglycemia, dyslipidemia, and hypertension. The goal of this review is to provide background on the disease process, discuss human studies and preclinical models that have examined treatment options. We also provide an in-depth rationale for the use of dietary ω3 polyunsaturated fatty acid (ω3 PUFA) supplements as a treatment option for NAFLD. This focus is based on recent studies indicating that NASH patients and preclinical mouse models of NASH have low levels of hepatic C20-22 ω3 PUFA. This decline in hepatic PUFA may account for the major phenotypic features associated with NASH, including steatosis, inflammation and fibrosis. Finally, our discussion will address the strengths and limitations of ω3 PUFA supplements use in NAFLD therapy.
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Affiliation(s)
- Donald B Jump
- Molecular Nutrition and Diabetes Research Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR 97331, United States.
| | - Kelli A Lytle
- Molecular Nutrition and Diabetes Research Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR 97331, United States
| | - Christopher M Depner
- Molecular Nutrition and Diabetes Research Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR 97331, United States
| | - Sasmita Tripathy
- Molecular Nutrition and Diabetes Research Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR 97331, United States
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17
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Tajima-Shirasaki N, Ishii KA, Takayama H, Shirasaki T, Iwama H, Chikamoto K, Saito Y, Iwasaki Y, Teraguchi A, Lan F, Kikuchi A, Takeshita Y, Murao K, Matsugo S, Kaneko S, Misu H, Takamura T. Eicosapentaenoic acid down-regulates expression of the selenoprotein P gene by inhibiting SREBP-1c protein independently of the AMP-activated protein kinase pathway in H4IIEC3 hepatocytes. J Biol Chem 2017; 292:10791-10800. [PMID: 28465347 DOI: 10.1074/jbc.m116.747006] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Revised: 04/27/2017] [Indexed: 02/05/2023] Open
Abstract
Selenoprotein P (encoded by SELENOP in humans, Selenop in rat), a liver-derived secretory protein, induces resistance to insulin and vascular endothelial growth factor (VEGF) in type 2 diabetes. Suppression of selenoprotein P may provide a novel therapeutic approach to treating type 2 diabetes; however, few drugs inhibiting SELENOP expression in hepatocytes have been identified. The present findings demonstrate that eicosapentaenoic acid (EPA) suppresses SELENOP expression by inactivating sterol regulatory element-binding protein-1c (SREBP-1c, encoded by Srebf1 in rat) in H4IIEC3 hepatocytes. Treatment with EPA caused concentration- and time-dependent reduction in SELENOP promoter activity. EPA activated AMP-activated protein kinase (AMPK); however, the inhibitory effect of EPA on SELENOP promoter activity was not canceled with an AMPK inhibitor compound C and dominant-negative AMPK transfection. Deletion mutant promoter assays and computational analysis of transcription factor-binding sites conserved among the species resulted in identification of a sterol regulatory element (SRE)-like site in the SELENOP promoter. A chromatin immunoprecipitation (ChIP) assay revealed that EPA decreases binding of SREBP-1c to the SELENOP promoter. Knockdown of Srebf1 resulted in a significant down-regulation of Selenop expression. Conversely, SREBP-1c overexpression inhibited the suppressive effect of EPA. These data provide a novel mechanism of action for EPA involving improvement of systemic insulin sensitivity through the regulation of selenoprotein P production independently of the AMPK pathway and suggest an additional approach to developing anti-diabetic drugs.
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Affiliation(s)
| | - Kiyo-Aki Ishii
- From the Departments of Endocrinology and Metabolism.,System Biology, and
| | - Hiroaki Takayama
- From the Departments of Endocrinology and Metabolism.,System Biology, and
| | - Takayoshi Shirasaki
- System Biology, and.,Advanced Medical Technology, Kanazawa University Graduate School of Health Medicine, 13-1 Takara-machi, Kanazawa, Ishikawa 920-8641
| | - Hisakazu Iwama
- the Life Science Research Center, Kagawa University, Ikenobe 1750-1, Miki-cho, Kita-gun, Kagawa 761-0793
| | - Keita Chikamoto
- From the Departments of Endocrinology and Metabolism.,the Division of Natural System, Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192
| | - Yoshiro Saito
- the Department of Medical Life Systems, Faculty of Medical and Life Sciences, Systems Life Sciences, Doshisha University, Kyotanabe, Kyoto 610-0394
| | | | | | - Fei Lan
- From the Departments of Endocrinology and Metabolism
| | - Akihiro Kikuchi
- From the Departments of Endocrinology and Metabolism.,System Biology, and
| | | | - Koji Murao
- the Department of Advanced Medicine, Kagawa University, Ikenobe 1750-1, Miki-cho, Kita-gun, Kagawa 761-0793, and
| | - Seiichi Matsugo
- the Division of Natural System, Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192
| | | | - Hirofumi Misu
- From the Departments of Endocrinology and Metabolism.,PRESTO, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012, Japan
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18
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Damiano F, Rochira A, Gnoni A, Siculella L. Action of Thyroid Hormones, T3 and T2, on Hepatic Fatty Acids: Differences in Metabolic Effects and Molecular Mechanisms. Int J Mol Sci 2017; 18:ijms18040744. [PMID: 28362337 PMCID: PMC5412329 DOI: 10.3390/ijms18040744] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2017] [Revised: 03/22/2017] [Accepted: 03/27/2017] [Indexed: 12/28/2022] Open
Abstract
The thyroid hormones (THs) 3,3′,5,5′-tetraiodo-l-thyronine (T4) and 3,5,3′-triiodo-l-thyronine (T3) influence many metabolic pathways. The major physiological function of THs is to sustain basal energy expenditure, by acting primarily on carbohydrate and lipid catabolism. Beyond the mobilization and degradation of lipids, at the hepatic level THs stimulate the de novo fatty acid synthesis (de novo lipogenesis, DNL), through both the modulation of gene expression and the rapid activation of cell signalling pathways. 3,5-Diiodo-l-thyronine (T2), previously considered only a T3 catabolite, has been shown to mimic some of T3 effects on lipid catabolism. However, T2 action is more rapid than that of T3, and seems to be independent of protein synthesis. An inhibitory effect on DNL has been documented for T2. Here, we give an overview of the mechanisms of THs action on liver fatty acid metabolism, focusing on the different effects exerted by T2 and T3 on the regulation of the DNL. The inhibitory action on DNL exerted by T2 makes this compound a potential and attractive drug for the treatment of some metabolic diseases and cancer.
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Affiliation(s)
- Fabrizio Damiano
- Laboratory of Biochemistry and Molecular Biology, Department of Biological and Environmental Sciences and Technologies, University of Salento, 73100 Lecce, Italy.
| | - Alessio Rochira
- Laboratory of Biochemistry and Molecular Biology, Department of Biological and Environmental Sciences and Technologies, University of Salento, 73100 Lecce, Italy.
| | - Antonio Gnoni
- Department of Basic Medical Sciences, Section of Medical Biochemistry, University of Bari Aldo Moro, 70125 Bari, Italy.
| | - Luisa Siculella
- Laboratory of Biochemistry and Molecular Biology, Department of Biological and Environmental Sciences and Technologies, University of Salento, 73100 Lecce, Italy.
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19
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Jump DB, Botolin D, Wang Y, Xu J, Christian B. Fatty acids and gene transcription. SCANDINAVIAN JOURNAL OF FOOD & NUTRITION 2016. [DOI: 10.1080/17482970601069318] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Donald B. Jump
- Departments of Physiology, Biochemistry and Molecular BiologyMichigan State UniversityMichiganUSA
| | - Daniela Botolin
- Departments of Physiology, Biochemistry and Molecular BiologyMichigan State UniversityMichiganUSA
| | - Yun Wang
- Departments of Physiology, Biochemistry and Molecular BiologyMichigan State UniversityMichiganUSA
| | - Jinghua Xu
- Departments of Physiology, Biochemistry and Molecular BiologyMichigan State UniversityMichiganUSA
| | - Barbara Christian
- Departments of Physiology, Biochemistry and Molecular BiologyMichigan State UniversityMichiganUSA
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20
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Effect of dietary n-3 fatty acids supplementation on fatty acid metabolism in atorvastatin-administered SHR.Cg-Lepr cp/NDmcr rats, a metabolic syndrome model. Biomed Pharmacother 2016; 85:372-379. [PMID: 27939244 DOI: 10.1016/j.biopha.2016.11.038] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Revised: 11/07/2016] [Accepted: 11/09/2016] [Indexed: 12/20/2022] Open
Abstract
The effects of cholesterol-lowering statins, which substantially benefit future cardiovascular events, on fatty acid metabolism have remained largely obscured. In this study, we investigated the effects of atorvastatin on fatty acid metabolism together with the effects of TAK-085 containing highly purified eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) ethyl ester on atorvastatin-induced n-3 polyunsaturated fatty acid lowering in SHR.Cg-Leprcp/NDmcr (SHRcp) rats, as a metabolic syndrome model. Supplementation with 10mg/kg body weight/day of atorvastatin for 17 weeks significantly decreased plasma total cholesterol and very low density lipoprotein cholesterol. Atorvastatin alone caused a subtle change in fatty acid composition particularly of EPA and DHA in the plasma, liver or erythrocyte membranes. However, the TAK-085 consistently increased both the levels of EPA and DHA in the plasma, liver and erythrocyte membranes. After confirming the reduction of plasma total cholesterol, 300mg/kg body weight/day of TAK-085 was continuously administered for another 6 weeks. Supplementation with TAK-085 did not decrease plasma total cholesterol but significantly increased the EPA and DHA levels in both the plasma and liver compared with rats administered atorvastatin only. Supplementation with atorvastatin alone significantly decreased sterol regulatory element-binding protein-1c, Δ5- and Δ6-desaturases, elongase-5, and stearoyl-coenzyme A (CoA) desaturase-2 levels and increased 3-hydroxy-3-methylglutaryl-CoA reductase mRNA expression in the liver compared with control rats. TAK-085 supplementation significantly increased stearoyl-CoA desaturase-2 mRNA expression. These results suggest that long-term supplementation with atorvastatin decreases the EPA and DHA levels by inhibiting the desaturation and elongation of n-3 fatty acid metabolism, while TAK-085 supplementation effectively replenishes this effect in SHRcp rat liver.
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21
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Pinolenic Acid Downregulates Lipid Anabolic Pathway in HepG2 Cells. Lipids 2016; 51:847-55. [DOI: 10.1007/s11745-016-4149-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Accepted: 03/31/2016] [Indexed: 12/15/2022]
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22
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Hepatotoxicity of piperazine designer drugs: up-regulation of key enzymes of cholesterol and lipid biosynthesis. Arch Toxicol 2016; 90:3045-3060. [DOI: 10.1007/s00204-016-1665-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 01/06/2016] [Indexed: 12/12/2022]
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23
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Antal O, Péter M, Hackler L, Mán I, Szebeni G, Ayaydin F, Hideghéty K, Vigh L, Kitajka K, Balogh G, Puskás LG. Lipidomic analysis reveals a radiosensitizing role of gamma-linolenic acid in glioma cells. Biochim Biophys Acta Mol Cell Biol Lipids 2015; 1851:1271-82. [PMID: 26092623 DOI: 10.1016/j.bbalip.2015.06.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Revised: 06/08/2015] [Accepted: 06/13/2015] [Indexed: 12/16/2022]
Abstract
Previous studies have demonstrated that gamma-linolenic acid (GLA) is effective against glioma cells under both in vitro and in vivo conditions. In the present study we determined how GLA alone or in combination with irradiation alters the fatty acid (FA) and lipid profiles, the lipid droplet (LD) content, the lipid biosynthetic gene expression and the apoptosis of glioma cells. In GLA-treated cells direct correlations were found between the levels of various FAs and the expression of the corresponding FA biosynthetic genes. The total levels of saturated and monosaturated FAs decreased in concert with the down-regulation of FASN and SCD1 gene expression. Similarly, decreased FADS1 gene expression was paralleled by lowered arachidonic acid (20:4 n-6) and eicosapentaenoic acid (20:5 n-3) contents, while the down-regulation of FADS2 expression was accompanied by a diminished docosahexaenoic acid (22:6 n-3) content. Detailed mass spectrometric analyses revealed that individual treatments gave rise to distinct lipidomic fingerprints. Following uptake, GLA was subjected to elongation, resulting in dihomo-gamma-linolenic acid (20:3 n-6, DGLA), which was used for the synthesis of the LD constituent triacylglycerols and cholesteryl esters. Accordingly, an increased number of LDs were observed in response to GLA administration after irradiation. GLA increased the radioresponsiveness of U87 MG cells, as demonstrated by an increase in the number of apoptotic cells determined by FACS analysis. In conclusion, treatment with GLA increased the apoptosis of irradiated glioma cells, and GLA might therefore increase the therapeutic efficacy of irradiation in the treatment of gliomas.
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Affiliation(s)
- Otilia Antal
- Laboratory for Functional Genomics, Institute of Genetics, Biological Research Center of the Hungarian Academy of Sciences, Szeged H-6726, Hungary
| | - Mária Péter
- Laboratory of Molecular Stress Biology, Membrane and Stress Biology Unit, Institute of Biochemistry, Biological Research Center of the Hungarian Academy of Sciences, Szeged H-6726, Hungary
| | | | - Imola Mán
- Avidin Ltd., Szeged H-6726, Hungary(3)
| | | | - Ferhan Ayaydin
- Cellular Imaging Laboratory, Biological Research Center of the Hungarian Academy of Sciences, Szeged H-6726, Hungary
| | - Katalin Hideghéty
- Department of Oncotherapy, Faculty of Medicine, University of Szeged, H-6720, Hungary
| | - László Vigh
- Laboratory of Molecular Stress Biology, Membrane and Stress Biology Unit, Institute of Biochemistry, Biological Research Center of the Hungarian Academy of Sciences, Szeged H-6726, Hungary
| | - Klára Kitajka
- Laboratory for Functional Genomics, Institute of Genetics, Biological Research Center of the Hungarian Academy of Sciences, Szeged H-6726, Hungary; Avidin Ltd., Szeged H-6726, Hungary(3)
| | - Gábor Balogh
- Laboratory of Molecular Stress Biology, Membrane and Stress Biology Unit, Institute of Biochemistry, Biological Research Center of the Hungarian Academy of Sciences, Szeged H-6726, Hungary
| | - Laszló G Puskás
- Laboratory for Functional Genomics, Institute of Genetics, Biological Research Center of the Hungarian Academy of Sciences, Szeged H-6726, Hungary; Avidin Ltd., Szeged H-6726, Hungary(3).
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Park S, Hwang IW, Makishima Y, Perales-Clemente E, Kato T, Niederländer NJ, Park EY, Terzic A. Spot14/Mig12 heterocomplex sequesters polymerization and restrains catalytic function of human acetyl-CoA carboxylase 2. J Mol Recognit 2014; 26:679-88. [PMID: 24277613 PMCID: PMC4283044 DOI: 10.1002/jmr.2313] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Revised: 08/20/2013] [Accepted: 08/21/2013] [Indexed: 01/17/2023]
Abstract
Acetyl-CoA carboxylase 2 (ACC2) is an isoform of ACC functioning as a negative regulator of fatty acid β-oxidation. Spot14, a thyroid hormone responsive protein, and Mig12, a Spot14 paralog, have recently been identified as regulators of fatty acid synthesis targeting ACC1, a distinctive subtype of ACC. Here, we examined whether Spot14/Mig12 modulates ACC2. Nanoscale protein topography mapped putative protein-protein interactions between purified human Spot14/Mig12 and ACC2, validated by functional assays. Human ACC2 displayed consistent enzymatic activity, and homogeneous particle distribution was probed by atomic force microscopy. Citrate-induced polymerization and enzymatic activity of ACC2 were restrained by the addition of the recombinant Spot14/Mig12 heterocomplex but only partially by the oligo-heterocomplex, demonstrating that the heterocomplex is a designated metabolic inhibitor of human ACC2. Moreover, Spot14/Mig12 demonstrated a sequestering role preventing an initial ACC2 nucleation step during filamentous polymer formation. Thus, the Spot14/Mig12 heterocomplex controls human ACC2 polymerization and catalytic function, emerging as a previously unrecognized molecular regulator in catalytic lipid metabolism.
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Affiliation(s)
- Sungjo Park
- Center for Regenerative Medicine, Mayo Clinic, Rochester, MN, USA; Marriott Heart Disease Research Program, Division of Cardiovascular Diseases, Departments of Medicine, Molecular Pharmacology and Experimental Therapeutics, and Medical Genetics, Mayo Clinic, Rochester, MN, USA
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25
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PPARα-independent actions of omega-3 PUFAs contribute to their beneficial effects on adiposity and glucose homeostasis. Sci Rep 2014; 4:5538. [PMID: 24986106 PMCID: PMC4078310 DOI: 10.1038/srep05538] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Accepted: 06/16/2014] [Indexed: 02/06/2023] Open
Abstract
Excess dietary lipid generally leads to fat deposition and impaired glucose homeostasis, but consumption of fish oil (FO) alleviates many of these detrimental effects. The beneficial effects of FO are thought to be mediated largely via activation of the nuclear receptor peroxisomal-proliferator-activated receptor α (PPARα) by omega-3 polyunsaturated fatty acids and the resulting upregulation of lipid catabolism. However, pharmacological and genetic PPARα manipulations have yielded variable results. We have compared the metabolic effects of FO supplementation and the synthetic PPARα agonist Wy-14,643 (WY) in mice fed a lard-based high-fat diet. In contrast to FO, WY treatment resulted in little protection against diet-induced obesity and glucose intolerance, despite upregulating many lipid metabolic pathways. These differences were likely due to differential effects on hepatic lipid synthesis, with FO decreasing and WY amplifying hepatic lipid accumulation. Our results highlight that the beneficial metabolic effects of FO are likely mediated through multiple independent pathways.
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26
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Wang Q, Tikhonenko M, Bozack SN, Lydic TA, Yan L, Panchy NL, Mcsorley KM, Faber MS, Yan Y, Boulton ME, Grant MB, Busik JV. Changes in the daily rhythm of lipid metabolism in the diabetic retina. PLoS One 2014; 9:e95028. [PMID: 24736612 PMCID: PMC3988159 DOI: 10.1371/journal.pone.0095028] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Accepted: 03/23/2014] [Indexed: 12/14/2022] Open
Abstract
Disruption of circadian regulation was recently shown to cause diabetes and metabolic disease. We have previously demonstrated that retinal lipid metabolism contributed to the development of diabetic retinopathy. The goal of this study was to determine the effect of diabetes on circadian regulation of clock genes and lipid metabolism genes in the retina and retinal endothelial cells (REC). Diabetes had a pronounced inhibitory effect on the negative clock arm with lower amplitude of the period (per) 1 in the retina; lower amplitude and a phase shift of per2 in the liver; and a loss of cryptochrome (cry) 2 rhythmic pattern in suprachiasmatic nucleus (SCN). The positive clock arm was increased by diabetes with higher amplitude of circadian locomotor output cycles kaput (CLOCK) and brain and muscle aryl-hydrocarbon receptor nuclear translocator-like 1 (bmal1) and phase shift in bmal1 rhythmic oscillations in the retina; and higher bmal1 amplitude in the SCN. Peroxisome proliferator-activated receptor (PPAR) α exhibited rhythmic oscillation in retina and liver; PPARγ had lower amplitude in diabetic liver; sterol regulatory element-binding protein (srebp) 1c had higher amplitude in the retina but lower in the liver in STZ- induced diabetic animals. Both of Elongase (Elovl) 2 and Elovl4 had a rhythmic oscillation pattern in the control retina. Diabetic retinas lost Elovl4 rhythmic oscillation and had lower amplitude of Elovl2 oscillations. In line with the in vivo data, circadian expression levels of CLOCK, bmal1 and srebp1c had higher amplitude in rat REC (rREC) isolated from diabetic rats compared with control rats, while PPARγ and Elovl2 had lower amplitude in diabetic rREC. In conclusion, diabetes causes dysregulation of circadian expression of clock genes and the genes controlling lipid metabolism in the retina with potential implications for the development of diabetic retinopathy.
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Affiliation(s)
- Qi Wang
- Department of Physiology, Michigan State University, East Lansing, Michigan, United States of America
| | - Maria Tikhonenko
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, United States of America
| | - Svetlana N. Bozack
- Department of Physiology, Michigan State University, East Lansing, Michigan, United States of America
| | - Todd A. Lydic
- Department of Chemistry, Michigan State University, East Lansing, Michigan, United States of America
| | - Lily Yan
- Department of Psychology Social Science, Michigan State University, East Lansing, Michigan, United States of America
| | - Nicholas L. Panchy
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, United States of America
| | - Kelly M. Mcsorley
- Department of Physiology, Michigan State University, East Lansing, Michigan, United States of America
| | - Matthew S. Faber
- Department of Physiology, Michigan State University, East Lansing, Michigan, United States of America
| | - Yuanqing Yan
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, Florida, United States of America
| | - Michael E. Boulton
- Department of Ophthalmology, Indiana University, Indianapolis, Indiana, United States of America
| | - Maria B. Grant
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, Florida, United States of America
| | - Julia V. Busik
- Department of Physiology, Michigan State University, East Lansing, Michigan, United States of America
- * E-mail:
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Karanth S, Tran VM, Kuberan B, Schlegel A. Polyunsaturated fatty acyl-coenzyme As are inhibitors of cholesterol biosynthesis in zebrafish and mice. Dis Model Mech 2013; 6:1365-77. [PMID: 24057001 PMCID: PMC3820260 DOI: 10.1242/dmm.013425] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Lipid disorders pose therapeutic challenges. Previously we discovered that mutation of the hepatocyte β-hydroxybutyrate transporter Slc16a6a in zebrafish causes hepatic steatosis during fasting, marked by increased hepatic triacylglycerol, but not cholesterol. This selective diversion of trapped ketogenic carbon atoms is surprising because acetate and acetoacetate can exit mitochondria and can be incorporated into both fatty acids and cholesterol in normal hepatocytes. To elucidate the mechanism of this selective diversion of carbon atoms to fatty acids, we fed wild-type and slc16a6a mutant animals high-protein ketogenic diets. We find that slc16a6a mutants have decreased activity of the rate-limiting enzyme of cholesterol biosynthesis, 3-hydroxy-3-methylglutaryl-coenzyme A reductase (Hmgcr), despite increased Hmgcr protein abundance and relative incorporation of mevalonate into cholesterol. These observations suggest the presence of an endogenous Hmgcr inhibitor. We took a candidate approach to identify such inhibitors. First, we found that mutant livers accumulate multiple polyunsaturated fatty acids (PUFAs) and PUFA-CoAs, and we showed that human HMGCR is inhibited by PUFA-CoAs in vitro. Second, we injected mice with an ethyl ester of the PUFA eicosapentaenoic acid and observed an acute decrease in hepatic Hmgcr activity, without alteration in Hmgcr protein abundance. These results elucidate a mechanism for PUFA-mediated cholesterol lowering through direct inhibition of Hmgcr.
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Affiliation(s)
- Santhosh Karanth
- University of Utah Molecular Medicine (U2M2) Program, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
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28
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Abstract
Fatty acid regulation of hepatic gene transcription was first reported in the early 1990s. Several transcription factors have been identified as targets of fatty acid regulation. This regulation is achieved by direct fatty acid binding to the transcription factor or by indirect mechanisms where fatty acids regulate signaling pathways controlling the expression of transcription factors or the phosphorylation, ubiquitination, or proteolytic cleavage of the transcription factor. Although dietary fatty acids are well-established regulators of hepatic transcription factors, emerging evidence indicates that endogenously generated fatty acids are equally important in controlling transcription factors in the context of glucose and lipid homeostasis. Our first goal in this review is to provide an up-to-date examination of the molecular and metabolic bases of fatty acid regulation of key transcription factors controlling hepatic metabolism. Our second goal is to link these mechanisms to nonalcoholic fatty liver disease (NAFLD), a growing health concern in the obese population.
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Affiliation(s)
- Donald B Jump
- Nutrition Program, School of Biological and Population Health Science, Linus Pauling Institute, Oregon State University, Corvallis, OR 97331, USA.
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29
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Arai T, Kim HJ, Hirako S, Nakasatomi M, Chiba H, Matsumoto A. Effects of dietary fat energy restriction and fish oil feeding on hepatic metabolic abnormalities and insulin resistance in KK mice with high-fat diet-induced obesity. J Nutr Biochem 2013; 24:267-73. [DOI: 10.1016/j.jnutbio.2012.06.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2011] [Revised: 06/01/2012] [Accepted: 06/02/2012] [Indexed: 12/22/2022]
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30
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Abstract
Consumption of specific dietary fatty acids has been shown to influence risk and progression of several chronic diseases, such as cardiovascular disease, obesity, cancer, and arthritis. In recent years, insights into the mechanisms underlying the biological effects of fatty acids have improved considerably and have provided the foundation for the emerging concept of fatty acid sensing, which can be interpreted as the property of fatty acids to influence biological processes by serving as signaling molecules. An important mechanism of fatty acid sensing is via stimulation or inhibition of DNA transcription. Here, we focus on fatty acid sensing via regulation of gene transcription and address the role of peroxisome proliferator-activated receptors, sterol regulatory element binding protein 1, Toll-like receptor 4, G protein-coupled receptors, and other putative mediators.
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Affiliation(s)
- Anastasia Georgiadi
- Nutrition, Metabolism and Genomics Group, Wageningen University, Wageningen, the Netherlands
| | - Sander Kersten
- Nutrition, Metabolism and Genomics Group, Wageningen University, Wageningen, the Netherlands
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31
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Madec S, Cerec V, Plée-Gautier E, Antoun J, Glaise D, Salaun JP, Guguen-Guillouzo C, Corlu A. CYP4F3B expression is associated with differentiation of HepaRG human hepatocytes and unaffected by fatty acid overload. Drug Metab Dispos 2011; 39:1987-96. [PMID: 21778351 DOI: 10.1124/dmd.110.036848] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Fatty acid microsomal ω-oxidation involves cytochrome P450 enzymes. Some of them belonging to the CYP4F3 family are mainly expressed in the liver, making this organ a major player in energy homeostasis and lipid metabolism. To study this important regulation pathway, we used HepaRG cells, which gradually undergo a complete differentiation process. Even at the early stage of the differentiation process, CYP4F3B generated by alternative splicing of the CYP4F3 gene represented the prevalent isoform in HepaRG cells as in the liver. Its increasing expression associated with hepatocyte differentiation status suggested a hepatic-specific control of this isoform. As in liver microsomes, the catalytic hydroxylation of the CYP4F3B substrate [1-¹⁴C]Z9(10)-epoxystearic acid led to major production of 18-hydroxy-9(10)-epoxystearic acid. When treated with saturated, monounsaturated, or polyunsaturated fatty acids, CYP4F3B and CYP4A11 expression remained unchanged whereas CYP4F2 and CYP4F12 expression was transiently up-regulated. A 24-h exposure of differentiated HepaRG cells to various polyunsaturated fatty acids and derivatives induced microvesicular steatosis; down-regulation of lipid metabolism gene regulators such as sterol regulatory element-binding protein-1c, fatty acid synthase, peroxisome proliferator-activated receptor γ (PPARγ), PPARα, and decreased expression of glucose-dependent metabolism genes, which could limit de novo lipogenesis. Docosahexaenoic acid seemed to be the most effective compound. These results suggest that a PPARα-independent pathway could participate to limit lipogenesis and emphasize the role of hepatocytes in the fatty acid ω-hydroxylation pathway. They also give insights on the use of HepaRG hepatocytes to open new avenues of investigations on factors mediating the lipid metabolic pathway and finding new hypolipidemic molecules.
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Affiliation(s)
- Stéphanie Madec
- Centre National de la Recherche Scientifique, UMR 7139, Station Biologique, Roscoff, France
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32
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Bordoni A, Di Nunzio M, Danesi F, Biagi PL. Polyunsaturated fatty acids: From diet to binding to ppars and other nuclear receptors. GENES AND NUTRITION 2011; 1:95-106. [PMID: 18850203 DOI: 10.1007/bf02829951] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2006] [Accepted: 06/21/2006] [Indexed: 01/01/2023]
Abstract
Dietary polyunsaturated fatty acids (PUFAs) function not only by altering membrane lipid composition, cellular metabolism, signal transduction, but possess also effects on gene expression by regulating the activity/abundance of different nuclear transcription factors: peroxisome proliferator activated receptors, retinoid X receptors, liver X receptors, hepatic nuclear factors-4a, and sterol regulatory binding proteins 1 and 2. PUFAs regulate the expression of genes in various tissues, including the liver, heart, adipose tissue, and brain, playing a major role in carbohydrate, fatty acid, triglyceride, and cholesterol metabolism. Before binding to transcription factors, PUFAs must be absorbed in the intestine and delivered to cells, and then they must enter the cell and the nucleus. PUFA concentration within the cell depends on many different factors, and regulate their possibility to act as transcription modulators. The aim of this review is to summarize recent knowledge about PUFAs destiny from dietto nuclear factors binding, examining the different variables which can modulate their interaction with nuclear factors themselves and therefore their effect on gene expression.
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Affiliation(s)
- A Bordoni
- Centro Ricerche sulla Nutrizione - Department of Biochemistry "G. Moruzzi", University of Bologna Via Irnerio, 48-40126, Bologna, Italy,
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Chronic dietary n-3 PUFA intervention improves dyslipidaemia and subsequent cardiovascular complications in the JCR:LA-cp rat model of the metabolic syndrome. Br J Nutr 2011; 105:1572-82. [DOI: 10.1017/s0007114510005453] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
There is increasing interest in the potential chronic beneficial effects of dietary n-3 PUFA on the metabolic syndrome (MetS) and associated cardiovascular complications. We have recently established that increased dietary n-3 PUFA has a profound acute benefit on fasting lipids and the postprandial pro-inflammatory response in the JCR:LA-cp rat, a model of the MetS. However, it is unclear to what extent chronic dietary n-3 PUFA intervention can modulate the progression of end-stage metabolic and vascular complications. The present study aimed to determine the chronic effects of dietary n-3 PUFA supplementation on fasting and non-fasting dyslipidaemia, insulin resistance and vascular complications in the JCR:LA-cp rodent model. JCR:LA-cp rats were fed an isoenergetic lipid-balanced diet supplemented with 5 % n-3 PUFA (w/w) of the total fat (fish oil-derived EPA/DHA) for 16 weeks. Fasting and non-fasting (postprandial) plasma lipid profile was assessed. Hepatic and adipose tissue was probed for the expression of lipogenic proteins (acyl-CoA carboxylase (ACC), fatty acid synthase (FAS) and sterol regulatory element-binding protein-1 (SREBP-1)), while the activity of Jun N-terminal kinase (JNK) was assessed via Western blot to target phosphorylated JNK protein in primary enterocytes. The frequency of myocardial lesions was assessed by haematoxylin and eosin staining. Increased dietary n-3 PUFA improved both the fasting and postprandial lipid profiles (TAG, cholesterol and apoB48) in the JCR:LA-cp rat, potentially via the down-regulation of the hepatic or adipose tissue expression of lipogenic enzymes (ACC, FAS and SREBP-1). Rats fed the 5 % n-3 PUFA diet had lower (58·2 %; P < 0·01) enterocytic phosphorylated JNK protein and secreted less cholesterol (30 %; P < 0·05) into mesenteric lymph compared with the control. The chronic metabolic benefits of dietary n-3 PUFA may underlie the potential to reduce vascular complications during the MetS, including the observed reduction in the frequency (approximately 80 %) of late-stage 3 myocardial lesions.
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Xiang Z, Qiao L, Zhou Y, Babiuk LA, Liu Q. Hepatitis C virus nonstructural protein-5A activates sterol regulatory element-binding protein-1c through transcription factor Sp1. Biochem Biophys Res Commun 2010; 402:549-53. [DOI: 10.1016/j.bbrc.2010.10.081] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2010] [Accepted: 10/19/2010] [Indexed: 02/08/2023]
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Abstract
Spot 14 (S14) is a protein that is abundantly expressed in lipogenic tissues and is regulated in a manner similar to other enzymes involved in fatty acid synthesis. Deletion of S14 in mice decreased lipid synthesis in lactating mammary tissue, but the mechanism of S14's action is unknown. Here we present the crystal structure of S14 to 2.65 Å and biochemical data showing that S14 can form heterodimers with MIG12. MIG12 modulates fatty acid synthesis by inducing the polymerization and activity of acetyl-CoA carboxylase, the first committed enzymatic reaction in the fatty acid synthesis pathway. Coexpression of S14 and MIG12 leads to heterodimers and reduced acetyl-CoA carboxylase polymerization and activity. The structure of S14 suggests a mechanism whereby heterodimer formation with MIG12 attenuates the ability of MIG12 to activate ACC.
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Matsumoto E, Ishihara A, Tamai S, Nemoto A, Iwase K, Hiwasa T, Shibata S, Takiguchi M. Time of day and nutrients in feeding govern daily expression rhythms of the gene for sterol regulatory element-binding protein (SREBP)-1 in the mouse liver. J Biol Chem 2010; 285:33028-33036. [PMID: 20720008 DOI: 10.1074/jbc.m109.089391] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Sterol regulatory element-binding protein-1 (SREBP-1) plays a central role in transcriptional regulation of genes for hepatic lipid synthesis that utilizes diet-derived nutrients such as carbohydrates and amino acids, and expression of SREBP-1 exhibits daily rhythms with a peak in the nocturnal feeding period under standard housing conditions of mice. Here, we report that the Srebp-1 expression rhythm shows time cue-independent and Clock mutation-sensitive circadian nature, and is synchronized with varied photoperiods apparently through entrainment of locomotor activity and food intake. Fasting caused diminution of Srebp-1 expression, while diabetic db/db and ob/ob mice showed constantly high expression with loss of rhythmicity. Time-restricted feedings during mid-light and mid-dark periods exhibited differential effects, the latter causing more severe damping of the oscillation. Therefore, "when to eat in a day (the light/dark cycle)," rather than "whenever to eat in a day," is a critical determinant to shape the daily rhythm of Srebp-1 expression. We further found that a high-carbohydrate diet and a high-protein diet, as well as a high-fat diet, cause phase shifts of the oscillation peak into the light period, underlining the importance of "what to eat." Daily rhythms of SREBP-1 protein levels and Akt phosphorylation levels also exhibited nutrient-responsive changes. Taken together, these findings provide a model for mechanisms by which time of day and nutrients in feeding shape daily rhythms of the Srebp-1 expression and possibly a number of other physiological functions with interindividual and interdaily differences in human beings and wild animals subjected to day-by-day changes in dietary timing and nutrients.
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Affiliation(s)
- Eriko Matsumoto
- From the Department of Biochemistry and Genetics, Chiba University Graduate School of Medicine, Inohana 1-8-1, Chiba 260-8670
| | - Akinori Ishihara
- From the Department of Biochemistry and Genetics, Chiba University Graduate School of Medicine, Inohana 1-8-1, Chiba 260-8670
| | - Saki Tamai
- From the Department of Biochemistry and Genetics, Chiba University Graduate School of Medicine, Inohana 1-8-1, Chiba 260-8670
| | - Ayako Nemoto
- From the Department of Biochemistry and Genetics, Chiba University Graduate School of Medicine, Inohana 1-8-1, Chiba 260-8670
| | - Katsuro Iwase
- From the Department of Biochemistry and Genetics, Chiba University Graduate School of Medicine, Inohana 1-8-1, Chiba 260-8670
| | - Takaki Hiwasa
- From the Department of Biochemistry and Genetics, Chiba University Graduate School of Medicine, Inohana 1-8-1, Chiba 260-8670
| | - Shigenobu Shibata
- Department of Pharmacology, School of Science and Engineering, Waseda University, Wakamatsu-cho 2-2, Shinjuku-ku 162-8480, Japan
| | - Masaki Takiguchi
- From the Department of Biochemistry and Genetics, Chiba University Graduate School of Medicine, Inohana 1-8-1, Chiba 260-8670.
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Translational control of the sterol-regulatory transcription factor SREBP-1 mRNA in response to serum starvation or ER stress is mediated by an internal ribosome entry site. Biochem J 2010; 429:603-12. [PMID: 20513236 DOI: 10.1042/bj20091827] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
SREBPs (sterol-regulatory-element-binding proteins) are a family of transcription factors that modulate the expression of several enzymes implicated in endogenous cholesterol, fatty acid, triacylglycerol and phospholipid synthesis. In the present study, evidence for SREBP-1 regulation at the translational level is reported. Using several experimental approaches, we have demonstrated that the 5'-UTR (untranslated region) of the SREBP-1a mRNA contains an IRES (internal ribosome entry site). Transfection experiments with the SREBP-1a 5'-UTR inserted in a dicistronic reporter vector showed a remarkable increase in the downstream cistron translation, through a cap-independent mechanism. Insertion of the SREBP-1c 5'-UTR in the same vector also stimulated the translation of the downstream cistron, but the observed effect can be ascribed, at least in part, to a cryptic promoter activity. Cellular stress conditions, such as serum starvation, caused an increase in the level of SREBP-1 precursor and mature form in both Hep G2 and HeLa cells, despite the overall reduction in protein synthesis, whereas mRNA levels for SREBP-1 were unaffected by serum starvation. Transfection experiments carried out with a dicistronic construct demonstrated that the cap-dependent translation was affected more than IRES-mediated translation by serum starvation. The thapsigargin- and tunicamycin-induced UPR (unfolded protein response) also increased SREBP-1 expression in Hep G2 cells, through the cap-independent translation mediated by IRES. Overall, these findings indicate that the presence of IRES in the SREBP-1a 5'-UTR allows translation to be maintained under conditions that are inhibitory to cap-dependent translation.
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38
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Sato R. Sterol metabolism and SREBP activation. Arch Biochem Biophys 2010; 501:177-81. [PMID: 20541520 DOI: 10.1016/j.abb.2010.06.004] [Citation(s) in RCA: 212] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2010] [Revised: 06/04/2010] [Accepted: 06/06/2010] [Indexed: 12/15/2022]
Abstract
Cholesterol is one of the major components of membrane lipids. Adjustment of the membrane cholesterol balance is, therefore, pivotal in the maintenance of cellular homeostasis. Cholesterol biosynthesis and uptake are tightly regulated at the transcriptional level through a negative feedback control. The transcription factor family known as sterol regulatory element-binding proteins (SREBPs) is in charge of this feedback control. In particular, SREBP-2 is activated in a cholesterol-dependent manner, and hence is deeply involved in regulation of the expression of genes closely related to cholesterol metabolism. Sterol metabolites, including cholesterol, 24,25-dihydrolanosterol and oxysterols, strongly participate in the regulation of sterol metabolism via binding to its particular proteins.
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Affiliation(s)
- Ryuichiro Sato
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan.
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Sun C, Wei ZW, Li Y. DHA regulates lipogenesis and lipolysis genes in mice adipose and liver. Mol Biol Rep 2010; 38:731-7. [DOI: 10.1007/s11033-010-0160-9] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2008] [Accepted: 06/24/2009] [Indexed: 12/12/2022]
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Lattka E, Eggers S, Moeller G, Heim K, Weber M, Mehta D, Prokisch H, Illig T, Adamski J. A common FADS2 promoter polymorphism increases promoter activity and facilitates binding of transcription factor ELK1. J Lipid Res 2010; 51:182-91. [PMID: 19546342 DOI: 10.1194/jlr.m900289-jlr200] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Fatty acid desaturases (FADS) play an important role in the formation of omega-6 and omega-3 highly unsaturated fatty acids (HUFAs). The composition of HUFAs in the human metabolome is important for membrane fluidity and for the modulation of essential physiological functions such as inflammation processes and brain development. Several recent studies reported significant associations of single nucleotide polymorphisms (SNPs) in the human FADS gene cluster with HUFA levels and composition. The presence of the minor allele correlated with a decrease of desaturase reaction products and an accumulation of substrates. We performed functional studies with two of the associated polymorphisms (rs3834458 and rs968567) and showed an influence of polymorphism rs968567 on FADS2 promoter activity by luciferase reporter gene assays. Electrophoretic mobility shift assays proved allele-dependent DNA-binding ability of at least two protein complexes to the region containing SNP rs968567. One of the proteins binding to this region in an allele-specific manner was shown to be the transcription factor ELK1 (a member of ETS domain transcription factor family). These results indicate that rs968567 influences FADS2 transcription and offer first insights into the modulation of complex regulation mechanisms of FADS2 gene transcription by SNPs.
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Affiliation(s)
- E Lattka
- Institute of Epidemiology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg Germany
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41
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Takeuchi Y, Yahagi N, Izumida Y, Nishi M, Kubota M, Teraoka Y, Yamamoto T, Matsuzaka T, Nakagawa Y, Sekiya M, Iizuka Y, Ohashi K, Osuga JI, Gotoda T, Ishibashi S, Itaka K, Kataoka K, Nagai R, Yamada N, Kadowaki T, Shimano H. Polyunsaturated fatty acids selectively suppress sterol regulatory element-binding protein-1 through proteolytic processing and autoloop regulatory circuit. J Biol Chem 2010; 285:11681-91. [PMID: 20145241 DOI: 10.1074/jbc.m109.096107] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Sterol regulatory element-binding protein (SREBP)-1 is a key transcription factor for the regulation of lipogenic enzyme genes in the liver. Polyunsaturated fatty acids (PUFA) selectively suppress hepatic SREBP-1, but molecular mechanisms remain largely unknown. To gain insight into this regulation, we established in vivo reporter assays to assess the activities of Srebf1c transcription and proteolytic processing. Using these in vivo reporter assays, we showed that the primary mechanism for PUFA suppression of SREBP-1 is at the proteolytic processing level and that this suppression in turn decreases the mRNA transcription through lowering SREBP-1 binding to the SREBP-binding element on the promoter ("autoloop regulatory circuit"), although liver X receptor, an activator for Srebf1c transcription, is not involved in this regulation by PUFA. The mechanisms for PUFA suppression of SREBP-1 confirm that the autoloop regulation for transcription is crucial for the nutritional regulation of triglyceride synthesis.
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Affiliation(s)
- Yoshinori Takeuchi
- Laboratory of Molecular Physiology on Energy Metabolism, Graduate School of Medicine, University of Tokyo, Tokyo, Japan
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Guha P, Aneja KK, Shilpi RY, Haldar D. Transcriptional regulation of mitochondrial glycerophosphate acyltransferase is mediated by distal promoter via ChREBP and SREBP-1. Arch Biochem Biophys 2009; 490:85-95. [PMID: 19682972 PMCID: PMC2761506 DOI: 10.1016/j.abb.2009.07.027] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2009] [Revised: 07/24/2009] [Accepted: 07/25/2009] [Indexed: 10/20/2022]
Abstract
We have recently identified two promoters, distal and proximal for rat mitochondrial glycerophosphate acyltransferase (mtGPAT). Here we are reporting further characterization of the promoters. Insulin and epidermal growth factor (EGF) stimulated while leptin and glucagon inhibited the luciferase activity of the distal promoter and the amounts of the distal transcript. Conversely, luciferase activity of the proximal promoter and proximal transcript remained unchanged due to these treatments. Only the distal promoter has binding sites for carbohydrate response element binding protein (ChREBP) and sterol regulatory element binding protein-1 (SREBP-1). Electromobility shift assays and chromatin immunoprecipitation assays demonstrated that ChREBP and SREBP-1 bind to the mtGPAT distal promoter. Insulin and EGF increased while glucagon and leptin decreased the binding of SREBP-1 and ChREBP to the distal promoter. Thus, the distal promoter is the regulatory promoter while the proximal promoter acts constitutively for rat mtGPAT gene under the influence of hormones and growth factor.
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Affiliation(s)
- Prajna Guha
- Department of Biological Sciences, St. John's University, Queens, NY 11439, USA
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Peroxisome proliferator-activated receptor beta/delta (PPARbeta/delta) but not PPARalpha serves as a plasma free fatty acid sensor in liver. Mol Cell Biol 2009; 29:6257-67. [PMID: 19805517 DOI: 10.1128/mcb.00370-09] [Citation(s) in RCA: 111] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Peroxisome proliferator-activated receptor alpha (PPARalpha) is an important transcription factor in liver that can be activated physiologically by fasting or pharmacologically by using high-affinity synthetic agonists. Here we initially set out to elucidate the similarities in gene induction between Wy14643 and fasting. Numerous genes were commonly regulated in liver between the two treatments, including many classical PPARalpha target genes, such as Aldh3a2 and Cpt2. Remarkably, several genes induced by Wy14643 were upregulated by fasting independently of PPARalpha, including Lpin2 and St3gal5, suggesting involvement of another transcription factor. Using chromatin immunoprecipitation, Lpin2 and St3gal5 were shown to be direct targets of PPARbeta/delta during fasting, whereas Aldh3a2 and Cpt2 were exclusive targets of PPARalpha. Binding of PPARbeta/delta to the Lpin2 and St3gal5 genes followed the plasma free fatty acid (FFA) concentration, consistent with activation of PPARbeta/delta by plasma FFAs. Subsequent experiments using transgenic and knockout mice for Angptl4, a potent stimulant of adipose tissue lipolysis, confirmed the stimulatory effect of plasma FFAs on Lpin2 and St3gal5 expression levels via PPARbeta/delta. In contrast, the data did not support activation of PPARalpha by plasma FFAs. The results identify Lpin2 and St3gal5 as novel PPARbeta/delta target genes and show that upregulation of gene expression by PPARbeta/delta is sensitive to plasma FFA levels. In contrast, this is not the case for PPARalpha, revealing a novel mechanism for functional differentiation between PPARs.
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Arai T, Kim HJ, Chiba H, Matsumoto A. Interaction of fenofibrate and fish oil in relation to lipid metabolism in mice. J Atheroscler Thromb 2009; 16:283-91. [PMID: 19556727 DOI: 10.5551/jat.e463] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
AIM The aim of our study is to elucidate the interactive effects on lipid metabolism of fenofibrate and two fish oils with EPA and DHA contents in mice. METHODS Female C57BL/6J mice were fed purified experimental diets containing safflower oil (SO), EPA-rich menhaden oil (MO) or DHA-rich tuna oil (TO) with or without 0.1% fenofibrate for 8 weeks. At the end of the experiments, we measured plasma lipids and hepatic triglycerides and cholesterol, and the hepatic mRNA expression of lipogenic and lipidolytic genes. RESULTS Plasma TG levels fell in the group fed MO or TO alone and fell significantly in all fenofibrate-treated groups. Although plasma total cholesterol levels fell significantly in fish oil-fed groups, fenofibrate treatments increased significantly plasma total cholesterol levels in these fish oil groups, but not in the group fed SO alone; however, hepatic triglyceride and total cholesterol levels markedly decreased in MO-or TO-fed mice. In lipid synthesis, the hepatic mRNA level of SREBP-1c was not reduced in either fish oil group; however, Insig-1 mRNA decreased in MO and TO feeding groups by about half and FAS or SCD-1 mRNA decreased significantly in MO and TO feeding groups, compared with the SO feeding group. In both fish oil groups, SREBP-2 mRNA decreased significantly and HMG-CoA reductase mRNA also decreased with/without fenofibrate. On the other hand, fenofibrate supplementation significantly induced the mRNA expression of AOX and UCP-2, which play a role in lipid catabolism, in all diets. CYP7A1 mRNA increased markedly in mice fed MO diet with fenofibrate, compared with TO diet with fenofibrate. CONCLUSION These data suggest that differences in dietary contents of EPA and DHA do not influence the inhibition of lipogenesis, and that fenofibrate supplementation stimulates fatty acid oxidation, regardless of the oil type; however, cholesterol catabolism was induced by a combination of EPA-rich fish oil and fenofibrate, which suggests that EPA has a greater synergistic ability for cholesterol catabolism induction by fenofibrate than DHA.
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Affiliation(s)
- Takeshi Arai
- Faculty of Pharmaceutical Sciences, Josai University, Sakado, Saitama 350-0295, Japan
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[Progresses on thyroid hormone responsive spot 14 (THRSP) gene in chickens and ducks]. YI CHUAN = HEREDITAS 2009; 31:131-6. [PMID: 19273419 DOI: 10.3724/sp.j.1005.2009.00131] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Thyroid hormone responsive spot 14 (THRSP), expressed in lipogenic tissues, is suggested as a transcription factor to regulate gene expression of rate-limiting enzymes in lipogenesis. Two THRSP isoforms, THRSPa and THRSPb, were detected at cDNA levels in chickens and ducks. Chicken THRSPa was speculated to be associated with growth development and lipid metabolism because of significant correlation between the indels in the coding region of THRSPalpha and growth, as well as abdominal fat traits of chickens. The differences of THRSP structure and expression between chickens and ducks were reviewed. Furthermore, polymorphism and genetic effects of THRSP gene in chickens and ducks were analyzed.
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Ballou MA, Gomes RC, Juchem SO, DePeters EJ. Effects of dietary supplemental fish oil during the peripartum period on blood metabolites and hepatic fatty acid compositions and total triacylglycerol concentrations of multiparous Holstein cows. J Dairy Sci 2009; 92:657-69. [PMID: 19164678 DOI: 10.3168/jds.2008-1196] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The objectives were to evaluate the effects of dietary fish oil on plasma metabolite, hepatic fatty acid composition, and total triacylglycerol concentrations. Multiparous Holstein cows (n = 42) were completely randomized to 1 of 3 treatments at 3 wk prepartum. Treatments were no supplemental lipid or supplemental lipid from either Energy Booster (Milk Specialties Co., Dundee, IL) or fish oil. Treatment diets were fed from -21 d relative to expected date of parturition until 10 d postpartum. Treatments were fed as a bolus before the a.m. feeding. The dose of lipid fed during the prepartum period was 250 g, whereas approximately 0.92% of the previous day's dry matter intake was supplemented postpartum. Blood was collected 3 times weekly for determination of plasma metabolites. Liver biopsies were performed at 21 and 10 d before expected date of parturition and 1 and 14 d after parturition to determine fatty acid compositions and total triacylglycerol concentrations. Dry matter intake, milk yield, and loss of body weight or body condition score were not affected by supplementing the diet with lipid or by the source of lipid. Supplemental lipid tended to increase plasma glucose and decrease nonesterified fatty acids during the postpartum period. Furthermore, plasma beta-hydroxybutyrate was reduced during the postpartum period in the lipid-supplemented treatments. However, source of supplemental lipid had no influence on any blood metabolite. Supplemental fish oil altered the fatty acid composition of liver phospholipids and triacylglycerols, decreasing total saturated fatty acids and increasing total n-3 and long-chain polyunsaturated fatty acids (>20 carbon fatty acids). Despite the altered fatty acid composition, hepatic total triacylglycerol concentrations were unaffected by supplemental fish oil. Furthermore, the improved metabolic profile following lipid supplementation did not decrease hepatic total triacylglycerol concentrations.
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Affiliation(s)
- M A Ballou
- Department of Animal Science and Nutritional Biology Graduate Group, University of California, Davis 95616, USA.
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Functional analysis of rat liver citrate carrier promoter: differential responsiveness to polyunsaturated fatty acids. Biochem J 2009; 417:561-71. [PMID: 18795892 DOI: 10.1042/bj20081082] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
CiC (citrate carrier), a mitochondrial membrane protein, plays an important metabolic role by transporting acetyl-CoA into the cytosol for fatty acid and cholesterol synthesis. Several studies showed that CiC activity and expression is regulated by dietary fatty acids. In the present study we report data on the structural and functional characterization of the 5'-flanking region of the rat Cic gene. By transient transfection assays in H4IIE rat hepatoma cells, a PUFA (polyunsaturated fatty acids) response region has been identified within the CiC promoter. A cluster of putative binding sites for several transcription factors, composed of a NF-Y (nuclear factor-Y) site, an E-box-like site, a SRE1 (sterol regulatory element 1)-like site and four Sp1 (stimulatory protein 1) sites, was localized in the promoter region. Luciferase reporter gene and gel mobility shift assays indicated that a functional E-box-like, essential to the basal CiC promoter activity, confers responsiveness to activation by SREBP (SRE-binding protein)-1c. This study provides evidence for SREBP-1c as a principal target for PUFA regulation of CiC transcription. In H4IIE cells, overexpression of nSREBP (nuclear SREBP)-1c over-rides arachidonic acid (C(20:4, n-6)) suppression, but does not prevent the repression by docosahexaenoic acid (C(22:6, n-3)). ChIP (chromatin immunoprecipitation) assays in H4IIE cells showed that docosahexaenoic acid affects the binding of NF-Y, Sp1 and SREBP-1 to the PUFA response region of CiC promoter, whereas arachidonic acid alters only the binding of SREBP-1. Our data show that PUFA inhibition of hepatic Cic gene transcription is mediated not only by the nuclear level of SREBP-1c, but also might involve a reduction in Sp1 and NF-Y DNA binding, suggesting differential mechanisms in the Cic gene regulation by different PUFA.
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Nakajima T, Tanaka N, Kanbe H, Hara A, Kamijo Y, Zhang X, Gonzalez FJ, Aoyama T. Bezafibrate at clinically relevant doses decreases serum/liver triglycerides via down-regulation of sterol regulatory element-binding protein-1c in mice: a novel peroxisome proliferator-activated receptor alpha-independent mechanism. Mol Pharmacol 2009; 75:782-92. [PMID: 19124612 DOI: 10.1124/mol.108.052928] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The triglyceride-lowering effect of bezafibrate in humans has been attributed to peroxisome proliferator-activated receptor (PPAR) alpha activation based on results from rodent studies. However, the bezafibrate dosages used in conventional rodent experiments are typically higher than those in clinical use (> or =50 versus < or =10 mg/kg/day), and thus it remains unclear whether such data can be translated to humans. Furthermore, because bezafibrate is a pan-PPAR activator, the actual contribution of PPARalpha to its triglyceride-lowering properties remains undetermined. To address these issues, bezafibrate at clinically relevant doses (10 mg/kg/day; low) was administered to wild-type and Ppara-null mice, and its effects were compared with those from conventionally used doses (100 mg/kg/day; high). Pharmacokinetic analyses showed that maximum plasma concentration and area under the concentration-time curve in bezafibrate-treated mice were similar to those in humans at low doses, but not at high doses. Low-dose bezafibrate decreased serum/liver triglycerides in a PPARalpha-independent manner by attenuation of hepatic lipogenesis and triglyceride secretion. It is noteworthy that instead of PPAR activation, down-regulation of sterol regulatory element-binding protein (SREBP)-1c was observed in mice undergoing low-dose treatment. High-dose bezafibrate decreased serum/liver triglycerides by enhancement of hepatic fatty acid uptake and beta-oxidation via PPARalpha activation, as expected. In conclusion, clinically relevant doses of bezafibrate exert a triglyceride-lowering effect by suppression of the SREBP-1c-regulated pathway in mice and not by PPARalpha activation. Our results may provide novel information about the pharmacological mechanism of bezafibrate action and new insights into the treatment of disorders involving SREBP-1c.
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Affiliation(s)
- Takero Nakajima
- Department of Metabolic Regulation, Institute on Aging and Adaptation, Shinshu University Graduate School of Medicine, Matsumoto, Japan
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Dietary fat source affects metabolism of fatty acids in pigs as evaluated by altered expression of lipogenic genes in liver and adipose tissues. Animal 2009; 3:535-42. [DOI: 10.1017/s1751731108003686] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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Regulation of hepatic fatty acid elongase 5 by LXRalpha-SREBP-1c. Biochim Biophys Acta Mol Cell Biol Lipids 2008; 1791:140-7. [PMID: 19136075 DOI: 10.1016/j.bbalip.2008.12.003] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2008] [Revised: 12/02/2008] [Accepted: 12/05/2008] [Indexed: 02/07/2023]
Abstract
Dietary essential fatty acids linoleic acid and alpha-linolenic acid are converted to arachidonic-, eicosapentaenoic-, and docosahexaenoic acid under tight regulation by nutritional status and hormones. Hepatic fatty acid elongase 5 (Elovl5) elongates C18-20 polyunsaturated fatty acids (PUFAs) and is important for biosynthesis of C20-22 PUFAs. We demonstrate that Liver X Receptor alpha (LXRalpha) and sterol regulatory binding protein-1c (SREBP-1c) regulate hepatic Elovl5 expression. LXRalpha and LXRbeta play different roles in maintenance of basal expression of Elovl5. LXRalpha is necessary for basal as well as LXR agonist induced Elovl5 transcription. Promoter studies revealed that the mouse Elovl5 gene is a direct SREBP-1c target. The up-regulation of Elovl5 expression by LXR agonist is likely secondary to the induction of SREBP-1c. PUFAs repress expression of SREBP-1c and Elovl5, but when combined with LXR ligand stimulation, which increases SREBP-1c mRNA and nuclear SREBP-1c, Elovl5 mRNA levels are restored to normal. Our studies suggest that an LXRalpha-SREBP-1c pathway plays a regulatory role in hepatic biosynthesis of PUFAs through transcriptional activation of Elovl5 as well as other desaturases. The stimulatory role of LXRalpha-SREBP-1c in the production of PUFAs enables the possibility for a feedback regulation of hepatic lipogenesis through PUFA mediated repression of SREBP-1c expression.
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