101
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Zhang P, Li L, Bao Z, Huang F. Role of BAF60a/BAF60c in chromatin remodeling and hepatic lipid metabolism. Nutr Metab (Lond) 2016; 13:30. [PMID: 27127533 PMCID: PMC4848843 DOI: 10.1186/s12986-016-0090-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Accepted: 04/19/2016] [Indexed: 02/07/2023] Open
Abstract
The switching defective/sucrose non-fermenting (SWI/SNF) complexes play an important role in hepatic lipid metabolism regulating both transcriptional activation and repression. BAF60a is a core subunit of the SWI/SNF chromatin-remodeling complexes that activates the transcription of fatty acid oxidation genes during fasting/glucagon. BAF60c, another subunit of SWI/SNF complexes, is recruited to form the lipoBAF complex that activates lipogenic genes, promoting lipogenesis and increasing the triglyceride level in response to feeding/insulin. Interestingly, hepatocytes located in the periportal and perivenous zones of the liver display a remarkable heterogeneity in the activity of various enzymes, metabolic functions and gene expression. Especially, fatty-acid oxidation was shown to be mostly periportal, whereas lipogenesis was mostly perivenous. Therefore, the present review highlights the role of of SWI/SNF regulating lipid metabolism under nutritional and hormonal control, which may be associated with hepatocyte heterogeneity.
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Affiliation(s)
- Ping Zhang
- Department of Animal Nutrition and Feed Science, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, 430070 China
| | - Lulu Li
- Department of Animal Nutrition and Feed Science, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, 430070 China
| | - Zhengxi Bao
- Department of Animal Nutrition and Feed Science, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, 430070 China
| | - Feiruo Huang
- Department of Animal Nutrition and Feed Science, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, 430070 China
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102
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Kihara A. Synthesis and degradation pathways, functions, and pathology of ceramides and epidermal acylceramides. Prog Lipid Res 2016; 63:50-69. [PMID: 27107674 DOI: 10.1016/j.plipres.2016.04.001] [Citation(s) in RCA: 145] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Revised: 04/08/2016] [Accepted: 04/20/2016] [Indexed: 10/21/2022]
Abstract
Ceramide (Cer) is a structural backbone of sphingolipids and is composed of a long-chain base and a fatty acid. Existence of a variety of Cer species, which differ in chain-length, hydroxylation status, and/or double bond number of either of their hydrophobic chains, has been reported. Ceramide is produced by Cer synthases. Mammals have six Cer synthases (CERS1-6), each of which exhibits characteristic substrate specificity toward acyl-CoAs with different chain-lengths. Knockout mice for each Cer synthase show corresponding, isozyme-specific phenotypes, revealing the functional differences of Cers with different chain-lengths. Cer diversity is especially prominent in epidermis. Changes in Cer levels, composition, and chain-lengths are associated with atopic dermatitis. Acylceramide (acyl-Cer) specifically exists in epidermis and plays an essential role in skin permeability barrier formation. Accordingly, defects in acyl-Cer synthesis cause the cutaneous disorder ichthyosis with accompanying severe skin barrier defects. Although the molecular mechanism by which acyl-Cer is generated was long unclear, most genes involved in its synthesis have been identified recently. In Cer degradation pathways, the long-chain base moiety of Cer is converted to acyl-CoA, which is then incorporated mainly into glycerophospholipids. This pathway generates the lipid mediator sphingosine 1-phosphate. This review will focus on recent advances in our understanding of the synthesis and degradation pathways, physiological functions, and pathology of Cers/acyl-Cers.
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Affiliation(s)
- Akio Kihara
- Laboratory of Biochemistry, Faculty of Pharmaceutical Sciences, Hokkaido University, Kita 12-jo, Nishi 6-choume, Kita-ku, Sapporo 060-0812, Japan.
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103
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Long-chain polyunsaturated fatty acid biosynthesis in chordates: Insights into the evolution of Fads and Elovl gene repertoire. Prog Lipid Res 2016; 62:25-40. [DOI: 10.1016/j.plipres.2016.01.001] [Citation(s) in RCA: 242] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Revised: 12/28/2015] [Accepted: 01/01/2016] [Indexed: 01/01/2023]
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104
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Cafeteria diet-induced obesity causes oxidative damage in white adipose. Biochem Biophys Res Commun 2016; 473:545-50. [PMID: 27033600 DOI: 10.1016/j.bbrc.2016.03.113] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Accepted: 03/23/2016] [Indexed: 01/01/2023]
Abstract
Obesity continues to be one of the most prominent public health dilemmas in the world. The complex interaction among the varied causes of obesity makes it a particularly challenging problem to address. While typical high-fat purified diets successfully induce weight gain in rodents, we have described a more robust model of diet-induced obesity based on feeding rats a diet consisting of highly palatable, energy-dense human junk foods - the "cafeteria" diet (CAF, 45-53% kcal from fat). We previously reported that CAF-fed rats became hyperphagic, gained more weight, and developed more severe hyperinsulinemia, hyperglycemia, and glucose intolerance compared to the lard-based 45% kcal from fat high fat diet-fed group. In addition, the CAF diet-fed group displayed a higher degree of inflammation in adipose and liver, mitochondrial dysfunction, and an increased concentration of lipid-derived, pro-inflammatory mediators. Building upon our previous findings, we aimed to determine mechanisms that underlie physiologic findings in the CAF diet. We investigated the effect of CAF diet-induced obesity on adipose tissue specifically using expression arrays and immunohistochemistry. Genomic evidence indicated the CAF diet induced alterations in the white adipose gene transcriptome, with notable suppression of glutathione-related genes and pathways involved in mitigating oxidative stress. Immunohistochemical analysis indicated a doubling in adipose lipid peroxidation marker 4-HNE levels compared to rats that remained lean on control standard chow diet. Our data indicates that the CAF diet drives an increase in oxidative damage in white adipose tissue that may affect tissue homeostasis. Oxidative stress drives activation of inflammatory kinases that can perturb insulin signaling leading to glucose intolerance and diabetes.
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105
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Dong X, Li Q, Zhang H. The noa gene is functionally linked to the activation of the Toll/Imd signaling pathways in Bactrocera dorsalis (Hendel). DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2016; 55:233-240. [PMID: 26404497 DOI: 10.1016/j.dci.2015.09.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Revised: 09/18/2015] [Accepted: 09/18/2015] [Indexed: 06/05/2023]
Abstract
The noa gene is an essential gene encoding a very long chain fatty acid elongase. In this study, we cloned the noa gene of Bactrocera dorsalis, which encodes a protein sharing 84.50% identity to the NOA in Drosophila melanogaster. The expression profiles indicated that the transcriptional level of noa was high at the egg stage and in the testis tissue. The results showed that noa expression was up-regulated after Listeria monocytogenes, Staphylococcus aureus and Escherichia coli infection. Silencing of noa would influence the expression of immune related genes, including MyD88 and defensin in the Toll pathway and relish and diptericin in the Imd pathway. Moreover, infection with L. monocytogenes and S. aureus after feeding ds-noa, the expression of MyD88 and defensin down-regulated significantly in ds-noa group compared with in ds-egfp group, indicating that noa interference influenced the activation of the Toll pathway. Meanwhile, infection with L. monocytogenes and E. coli, which activated the Imd pathway, do not cause increase of the mRNA levels of relish and diptericin in ds-noa group as severely as in ds-egfp treatment, indicating that the Imd pathway was also repressed after silences of noa.
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Affiliation(s)
- Xiaolong Dong
- State Key Laboratory of Agricultural Microbiology, Institute of Urban and Horticultural Entomology, and Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Qiujia Li
- State Key Laboratory of Agricultural Microbiology, Institute of Urban and Horticultural Entomology, and Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Hongyu Zhang
- State Key Laboratory of Agricultural Microbiology, Institute of Urban and Horticultural Entomology, and Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
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106
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Kuba M, Matsuzaka T, Matsumori R, Saito R, Kaga N, Taka H, Ikehata K, Okada N, Kikuchi T, Ohno H, Han SI, Takeuchi Y, Kobayashi K, Iwasaki H, Yatoh S, Suzuki H, Sone H, Yahagi N, Arakawa Y, Fujimura T, Nakagawa Y, Yamada N, Shimano H. Absence of Elovl6 attenuates steatohepatitis but promotes gallstone formation in a lithogenic diet-fed Ldlr(-/-) mouse model. Sci Rep 2015; 5:17604. [PMID: 26619823 PMCID: PMC4664962 DOI: 10.1038/srep17604] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Accepted: 10/30/2015] [Indexed: 12/15/2022] Open
Abstract
Nonalcoholic steatohepatitis (NASH) is a progressive form of nonalcoholic fatty liver disease (NAFLD) that can develop into liver cirrhosis and cancer. Elongation of very long chain fatty acids (ELOVL) family member 6 (Elovl6) is a microsomal enzyme that regulates the elongation of C12–16 saturated and monounsaturated fatty acids (FAs). We have previously shown that Elovl6 plays an important role in the development of hepatic insulin resistance and NASH by modifying FA composition. Recent studies have linked altered hepatic cholesterol homeostasis and cholesterol accumulation to the pathogenesis of NASH. In the present study, we further investigated the role of Elovl6 in the progression of lithogenic diet (LD)-induced steatohepatitis. We showed that the absence of Elovl6 suppresses hepatic lipid accumulation, plasma total cholesterol and total bile acid (BA) levels in LDL receptor-deficient (Ldlr−/−) mice challenged with a LD. The absence of Elovl6 also decreases hepatic inflammation, oxidative stress and liver injury, but increases the formation of cholesterol crystals in the less dilated gallbladder. These findings suggest that Elovl6-mediated changes in hepatic FA composition, especially oleic acid (C18:1n-9), control handling of hepatic cholesterol and BA, which protects against hepatotoxicity and steatohepatitis, but promotes gallstone formation in LD-fed Ldlr−/− mice.
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Affiliation(s)
- Motoko Kuba
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Takashi Matsuzaka
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Rie Matsumori
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Ryo Saito
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Naoko Kaga
- Laboratory of Proteomics and Biomolecular Science, Biomedical Research Center, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan
| | - Hikari Taka
- Laboratory of Proteomics and Biomolecular Science, Biomedical Research Center, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan
| | - Kei Ikehata
- Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan
| | - Naduki Okada
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Takuya Kikuchi
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Hiroshi Ohno
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Song-Iee Han
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Yoshinori Takeuchi
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Kazuto Kobayashi
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Hitoshi Iwasaki
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Shigeru Yatoh
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Hiroaki Suzuki
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Hirohito Sone
- Department of Internal Medicine, Faculty of Medicine, Niigata University, 1-754 Asahimachi, Niigata 951-8510, Japan
| | - Naoya Yahagi
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Yoji Arakawa
- Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan
| | - Tsutomu Fujimura
- Laboratory of Proteomics and Biomolecular Science, Biomedical Research Center, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan
| | - Yoshimi Nakagawa
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan.,International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Nobuhiro Yamada
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Hitoshi Shimano
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan.,International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Ibaraki, Japan
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107
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Morita M, Kawamichi M, Shimura Y, Kawaguchi K, Watanabe S, Imanaka T. Brain microsomal fatty acid elongation is increased in abcd1-deficient mouse during active myelination phase. Metab Brain Dis 2015; 30:1359-67. [PMID: 26108493 DOI: 10.1007/s11011-015-9701-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Accepted: 06/12/2015] [Indexed: 10/23/2022]
Abstract
The dysfunction of ABCD1, a peroxisomal ABC protein, leads to the perturbation of very long chain fatty acid (VLCFA) metabolism and is the cause of X-linked adrenoleukodystrophy. Abcd1-deficient mice exhibit an accumulation of saturated VLCFAs, such as C26:0, in all tissues, especially the brain. The present study sought to measure microsomal fatty acid elongation activity in the brain of wild-type (WT) and abcd1-deficient mice during the course of development. The fatty acid elongation activity in the microsomal fraction was measured by the incorporation of [2-(14)C]malonyl-CoA into fatty acids in the presence of C16:0-CoA or C20:0-CoA. Cytosolic fatty acid synthesis activity was completely inhibited by the addition of N-ethylmaleimide (NEM). The microsomal fatty acid elongation activity in the brain was significantly high at 3 weeks after birth and decreased substantially at 3 months after birth. Furthermore, we detected two different types of microsomal fatty acid elongation activity by using C16:0-CoA or C20:0-CoA as the substrate and found the activity toward C20:0-CoA in abcd1-deficient mice was higher than the WT 3-week-old animals. These results suggest that during the active myelination phase the microsomal fatty acid elongation activity is stimulated in abcd1-deficient mice, which in turn perturbs the lipid composition in myelin.
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Affiliation(s)
- Masashi Morita
- Department of Biological Chemistry, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama, 930-0194, Japan.
| | - Misato Kawamichi
- Department of Biological Chemistry, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama, 930-0194, Japan
| | - Yusuke Shimura
- Department of Biological Chemistry, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama, 930-0194, Japan
| | - Kosuke Kawaguchi
- Department of Biological Chemistry, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama, 930-0194, Japan
| | - Shiro Watanabe
- Institute of Natural Medicine, University of Toyama, 2630 Sugitani, Toyama, 930-0194, Japan
| | - Tsuneo Imanaka
- Department of Biological Chemistry, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama, 930-0194, Japan
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108
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Brown Adipose Tissue Thermogenic Capacity Is Regulated by Elovl6. Cell Rep 2015; 13:2039-47. [PMID: 26628376 PMCID: PMC4688035 DOI: 10.1016/j.celrep.2015.11.004] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Revised: 09/18/2015] [Accepted: 10/31/2015] [Indexed: 01/20/2023] Open
Abstract
Although many transcriptional pathways regulating BAT have been identified, the role of lipid biosynthetic enzymes in thermogenesis has been less investigated. Whereas cold exposure causes changes in the fatty acid composition of BAT, the functional consequences of this remains relatively unexplored. In this study, we demonstrate that the enzyme Elongation of Very Long Chain fatty acids 6 (Elovl6) is necessary for the thermogenic action of BAT. Elovl6 is responsible for converting C16 non-essential fatty acids into C18 species. Loss of Elovl6 does not modulate traditional BAT markers; instead, it causes reduced expression of mitochondrial electron transport chain components and lower BAT thermogenic capacity. The reduction in BAT activity appears to be counteracted by increased beiging of scWAT. When beige fat is disabled by thermoneutrality or aging, Elovl6 KO mice gain weight and have increased scWAT mass and impaired carbohydrate metabolism. Overall, our study suggests fatty acid chain length is important for BAT function. The fatty acid elongase Elovl6 is a thermogenically regulated gene in BAT Elovl6 is necessary for full thermogenic recruitment of brown adipose tissue Elovl6 acts by regulating mitochondrial function in brown adipose tissue
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109
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Tucci S, Behringer S, Spiekerkoetter U. De novo fatty acid biosynthesis and elongation in very long-chain acyl-CoA dehydrogenase-deficient mice supplemented with odd or even medium-chain fatty acids. FEBS J 2015; 282:4242-53. [PMID: 26284828 DOI: 10.1111/febs.13418] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Revised: 07/30/2015] [Accepted: 08/13/2015] [Indexed: 12/31/2022]
Abstract
An even medium-chain triglyceride (MCT)-based diet is the mainstay of treatment in very long-chain acyl-CoA dehydrogenase (VLCAD) deficiency (VLCADD). Previous studies with magnetic resonance spectroscopy have shown an impact of MCT on the average fatty acid chain length in abdominal fat. We therefore assume that medium-chain fatty acids (MCFAs) are elongated and accumulate in tissue as long-chain fatty acids. In this study, we explored the hepatic effects of long-term supplementation with MCT or triheptanoin, an odd-chain C7-based triglyceride, in wild-type and VLCAD-deficient (VLCAD(-/-) ) mice after 1 year of supplementation as compared with a control diet. The de novo biosynthesis and elongation of fatty acids, and peroxisomal β-oxidation, were quantified by RT-PCR. This was followed by a comprehensive analysis of hepatic and cardiac fatty acid profiles by GC-MS. Long-term application of even and odd MCFAs strongly induced de novo biosynthesis and elongation of fatty acids in both wild-type and VLCAD(-/-) mice, leading to an alteration of the hepatic fatty acid profiles. We detected de novo-synthesized and elongated fatty acids, such as heptadecenoic acid (C17:1n9), eicosanoic acid (C20:1n9), erucic acid (C22:1n9), and mead acid (C20:3n9), that were otherwise completely absent in mice under control conditions. In parallel, the content of monounsaturated fatty acids was massively increased. Furthermore, we observed strong upregulation of peroxisomal β-oxidation in VLCAD(-/-) mice, especially when they were fed an MCT diet. Our data raise the question of whether long-term MCFA supplementation represents the most efficient treatment in the long term. Studies on the hepatic toxicity of triheptanoin are still ongoing.
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Affiliation(s)
- Sara Tucci
- Department of General Paediatrics, Centre for Pediatrics and Adolescent Medicine, University Hospital Freiburg, Germany
| | - Sidney Behringer
- Department of General Paediatrics, Centre for Pediatrics and Adolescent Medicine, University Hospital Freiburg, Germany
| | - Ute Spiekerkoetter
- Department of General Paediatrics, Centre for Pediatrics and Adolescent Medicine, University Hospital Freiburg, Germany
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110
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Shikama A, Shinozaki H, Takeuchi Y, Matsuzaka T, Aita Y, Murayama T, Sawada Y, Piao X, Toya N, Oya Y, Takarada A, Masuda Y, Nishi M, Kubota M, Izumida Y, Nakagawa Y, Iwasaki H, Kobayashi K, Yatoh S, Suzuki H, Yagyu H, Kawakami Y, Yamada N, Shimano H, Yahagi N. Identification of human ELOVL5 enhancer regions controlled by SREBP. Biochem Biophys Res Commun 2015; 465:857-63. [PMID: 26321664 DOI: 10.1016/j.bbrc.2015.08.101] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Accepted: 08/22/2015] [Indexed: 12/22/2022]
Abstract
Fatty acid elongase 5 (ELOVL5) is an enzyme involved in the synthesis of polyunsaturated fatty acids. Sterol Regulatory Element-binding Protein (SREBP)-1 activates ELOVL5 and increases polyunsaturated fatty acid synthesis, which in turn negatively affects SREBP-1 expression. Thus, ELOVL5 has been established as an SREBP-1 target gene and an important component of the negative feedback loop of de novo lipogenesis. However, the human ELOVL5 promoter/enhancer has not been fully analyzed and the location of SREBP biding sites around the ELOVL5 gene has yet to be defined. Here we performed a detailed promoter/enhancer analysis of human ELOVL5 gene, and identified two new SREBP binding sites, one in the 10 kb upstream region and one in the exon 1. These two SRE motifs are conserved among mammals and the mechanism found in the present study by which SREBP activates ELOVL5 is considered to be common in mammals. Through these findings, we clarified the molecular mechanism how SREBP activates ELOVL5, an important regulator of de novo lipogenesis.
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Affiliation(s)
- Akito Shikama
- Nutrigenomics Research Group, Faculty of Medicine, University of Tsukuba, Japan
| | - Haruna Shinozaki
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Japan
| | - Yoshinori Takeuchi
- Nutrigenomics Research Group, Faculty of Medicine, University of Tsukuba, Japan
| | - Takashi Matsuzaka
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Japan
| | - Yuichi Aita
- Nutrigenomics Research Group, Faculty of Medicine, University of Tsukuba, Japan
| | - Tomoki Murayama
- Nutrigenomics Research Group, Faculty of Medicine, University of Tsukuba, Japan
| | - Yoshikazu Sawada
- Nutrigenomics Research Group, Faculty of Medicine, University of Tsukuba, Japan
| | - Xiaoying Piao
- Nutrigenomics Research Group, Faculty of Medicine, University of Tsukuba, Japan
| | - Naoki Toya
- Nutrigenomics Research Group, Faculty of Medicine, University of Tsukuba, Japan
| | - Yukari Oya
- Nutrigenomics Research Group, Faculty of Medicine, University of Tsukuba, Japan
| | - Ayako Takarada
- Nutrigenomics Research Group, Faculty of Medicine, University of Tsukuba, Japan
| | - Yukari Masuda
- Nutrigenomics Research Group, Faculty of Medicine, University of Tsukuba, Japan
| | - Makiko Nishi
- Nutrigenomics Research Group, Faculty of Medicine, University of Tsukuba, Japan
| | - Midori Kubota
- Nutrigenomics Research Group, Faculty of Medicine, University of Tsukuba, Japan
| | - Yoshihiko Izumida
- Nutrigenomics Research Group, Faculty of Medicine, University of Tsukuba, Japan
| | - Yoshimi Nakagawa
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Japan
| | - Hitoshi Iwasaki
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Japan
| | - Kazuto Kobayashi
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Japan
| | - Shigeru Yatoh
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Japan
| | - Hiroaki Suzuki
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Japan
| | - Hiroaki Yagyu
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Japan
| | - Yasushi Kawakami
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Japan
| | - Nobuhiro Yamada
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Japan
| | - Hitoshi Shimano
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Japan
| | - Naoya Yahagi
- Nutrigenomics Research Group, Faculty of Medicine, University of Tsukuba, Japan.
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111
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Kalish BT, Fell GL, Nandivada P, Puder M. Clinically Relevant Mechanisms of Lipid Synthesis, Transport, and Storage. JPEN J Parenter Enteral Nutr 2015; 39:8S-17S. [PMID: 26187937 DOI: 10.1177/0148607115595974] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 05/26/2015] [Indexed: 12/19/2022]
Abstract
Lipids not only are fundamental nutrients but also serve as basic structural components of cells and as multifunctional signaling molecules. Lipid metabolism pathways underlie basic processes in health and disease and are the targets of novel therapeutics. In this review, we explore the molecular control of lipid synthesis, trafficking, and storage, with a focus on clinically relevant pathways. To illustrate the clinical relevance of molecular lipid regulation, we highlight how these biochemical processes contribute to the pathogenesis of nonalcoholic fatty liver disease, a component of the metabolic syndrome and a paradigmatic example of lipid dysregulation.
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Affiliation(s)
- Brian T Kalish
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Gillian L Fell
- Department of Surgery and The Vascular Biology Program, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Prathima Nandivada
- Department of Surgery and The Vascular Biology Program, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Mark Puder
- Department of Surgery and The Vascular Biology Program, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
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Cui XB, Luan JN, Chen SY. RGC-32 Deficiency Protects against Hepatic Steatosis by Reducing Lipogenesis. J Biol Chem 2015; 290:20387-95. [PMID: 26134570 DOI: 10.1074/jbc.m114.630186] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Indexed: 12/20/2022] Open
Abstract
Hepatic steatosis is associated with insulin resistance and metabolic syndrome because of increased hepatic triglyceride content. We have reported previously that deficiency of response gene to complement 32 (RGC-32) prevents high-fat diet (HFD)-induced obesity and insulin resistance in mice. This study was conducted to determine the role of RGC-32 in the regulation of hepatic steatosis. We observed that hepatic RGC-32 was induced dramatically by both HFD challenge and ethanol administration. RGC-32 knockout (RGC32(-/-)) mice were resistant to HFD- and ethanol-induced hepatic steatosis. The hepatic triglyceride content of RGC32(-/-) mice was decreased significantly compared with WT controls even under normal chow conditions. Moreover, RGC-32 deficiency decreased the expression of lipogenesis-related genes, sterol regulatory element binding protein 1c (SREBP-1c), fatty acid synthase, and stearoyl-CoA desaturase 1 (SCD1). RGC-32 deficiency also decreased SCD1 activity, as indicated by decreased desaturase indices of the liver and serum. Mechanistically, insulin and ethanol induced RGC-32 expression through the NF-κB signaling pathway, which, in turn, increased SCD1 expression in a SREBP-1c-dependent manner. RGC-32 also promoted SREBP-1c expression through activating liver X receptor. These results demonstrate that RGC-32 contributes to the development of hepatic steatosis by facilitating de novo lipogenesis through activating liver X receptor, leading to the induction of SREBP-1c and its target genes. Therefore, RGC-32 may be a potential novel drug target for the treatment of hepatic steatosis and its related diseases.
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Affiliation(s)
- Xiao-Bing Cui
- From the Department of Physiology and Pharmacology, University of Georgia, Athens, Georgia 30602 and
| | - Jun-Na Luan
- From the Department of Physiology and Pharmacology, University of Georgia, Athens, Georgia 30602 and
| | - Shi-You Chen
- From the Department of Physiology and Pharmacology, University of Georgia, Athens, Georgia 30602 and the Institute of Clinical Medicine and Department of Cardiology, Renmin Hospital, Hubei Medical University, Shiyan, 442000 Hubei, China
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Nagata Y, Ishizaki I, Waki M, Ide Y, Hossen MA, Ohnishi K, Miyayama T, Setou M. Palmitic acid, verified by lipid profiling using secondary ion mass spectrometry, demonstrates anti-multiple myeloma activity. Leuk Res 2015; 39:638-45. [DOI: 10.1016/j.leukres.2015.02.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Revised: 12/10/2014] [Accepted: 02/21/2015] [Indexed: 01/22/2023]
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114
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Bellemare V, Phaneuf D, Luu-The V. Target deletion of the bifunctional type 12 17β-hydroxysteroid dehydrogenase in mice results in reduction of androgen and estrogen levels in heterozygotes and embryonic lethality in homozygotes. Horm Mol Biol Clin Investig 2015; 2:311-8. [PMID: 25961203 DOI: 10.1515/hmbci.2010.036] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2010] [Accepted: 07/20/2010] [Indexed: 11/15/2022]
Abstract
17β-Hydroxysteroid dehydrogenases (17β-HSDs) are enzymes issued from convergent evolution of activity from various ancestral genes having different functions. Type 12 17β-HSD (17β-HSD12) was described as a bifunctional enzyme, involved in the biosynthesis of estradiol (E2) and the elongation of very long chain fatty acid (VLCFA). It catalyzes selectively the transformation of estrone (E1) into estradiol (E2) in human and primates, whereas in the mouse and Caenorhabditis elegans the enzyme catalyzes the 17β-reduction of both androgens and estrogens. It is also able to catalyze the reduction of 3-keto-acylCoA into 3-hydroxy-acylCoA in the elongation cycle of VLCFA biosynthesis. To further understand the physiological role of 17β-HSD12, we performed targeted disruption of the Hsd17b12 gene by substituting exons 8 and 9 that contain the active site with a neomycin cassette. The data indicate that heterozygous (HSD17B12+/-) mice are viable with reduced levels of sex steroids, whereas homozygous (HSD17B12-/-) mice show embryonic lethality. The present data are in agreement with the bifunctional activities of 17β-HSD12 suggesting that the VLCFA elongation activity, having its origin in the yeast, is most probably responsible for embryonic lethality in HSD17B12-/-, whereas the more recently acquired 17β-HSD12 activity is responsible for reduced sex steroid levels in HSD17B12+/-.
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115
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Decreased level of phosphatidylcholine (16:0/20:4) in multiple myeloma cells compared to plasma cells: a single-cell MALDI–IMS approach. Anal Bioanal Chem 2015; 407:5273-80. [DOI: 10.1007/s00216-015-8741-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2014] [Revised: 04/16/2015] [Accepted: 04/24/2015] [Indexed: 10/23/2022]
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116
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Corominas J, Marchesi JAP, Puig-Oliveras A, Revilla M, Estellé J, Alves E, Folch JM, Ballester M. Epigenetic regulation of the ELOVL6 gene is associated with a major QTL effect on fatty acid composition in pigs. Genet Sel Evol 2015; 47:20. [PMID: 25887840 PMCID: PMC4371617 DOI: 10.1186/s12711-015-0111-y] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Accepted: 03/04/2015] [Indexed: 11/16/2022] Open
Abstract
Background In previous studies on an Iberian x Landrace cross, we have provided evidence that supported the porcine ELOVL6 gene as the major causative gene of the QTL on pig chromosome 8 for palmitic and palmitoleic acid contents in muscle and backfat. The single nucleotide polymorphism (SNP) ELOVL6:c.-533C > T located in the promoter region of ELOVL6 was found to be highly associated with ELOVL6 expression and, accordingly, with the percentages of palmitic and palmitoleic acids in longissimus dorsi and adipose tissue. The main goal of the current work was to further study the role of ELOVL6 on these traits by analyzing the regulation of the expression of ELOVL6 and the implication of ELOVL6 polymorphisms on meat quality traits in pigs. Results High-throughput sequencing of BAC clones that contain the porcine ELOVL6 gene coupled to RNAseq data re-analysis showed that two isoforms of this gene are expressed in liver and adipose tissue and that they differ in number of exons and 3’UTR length. Although several SNPs in the 3’UTR of ELOVL6 were associated with palmitic and palmitoleic acid contents, this association was lower than that previously observed with SNP ELOVL6:c.-533C > T. This SNP is in full linkage disequilibrium with SNP ELOVL6:c.-394G > A that was identified in the binding site for estrogen receptor alpha (ERα). Interestingly, the ELOVL6:c.-394G allele is associated with an increase in methylation levels of the ELOVL6 promoter and with a decrease of ELOVL6 expression. Therefore, ERα is clearly a good candidate to explain the regulation of ELOVL6 expression through dynamic epigenetic changes in the binding site of known regulators of ELOVL6 gene, such as SREBF1 and SP1. Conclusions Our results strongly suggest the ELOVL6:c.-394G > A polymorphism as the causal mutation for the QTL on pig chromosome 8 that affects fatty acid composition in pigs. Electronic supplementary material The online version of this article (doi:10.1186/s12711-015-0111-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jordi Corominas
- Plant and Animal Genomics, Centre de Recerca en Agrigenòmica (Consorci CSIC-IRTA-UAB-UB), Edifici CRAG, Campus UAB, Bellaterra, Barcelona, 08193, Spain. .,Departament de Ciència Animal i dels Aliments, Facultat de Veterinària, Campus UAB, Bellaterra, Barcelona, 08193, Spain.
| | - Jorge A P Marchesi
- Plant and Animal Genomics, Centre de Recerca en Agrigenòmica (Consorci CSIC-IRTA-UAB-UB), Edifici CRAG, Campus UAB, Bellaterra, Barcelona, 08193, Spain.
| | - Anna Puig-Oliveras
- Plant and Animal Genomics, Centre de Recerca en Agrigenòmica (Consorci CSIC-IRTA-UAB-UB), Edifici CRAG, Campus UAB, Bellaterra, Barcelona, 08193, Spain. .,Departament de Ciència Animal i dels Aliments, Facultat de Veterinària, Campus UAB, Bellaterra, Barcelona, 08193, Spain.
| | - Manuel Revilla
- Plant and Animal Genomics, Centre de Recerca en Agrigenòmica (Consorci CSIC-IRTA-UAB-UB), Edifici CRAG, Campus UAB, Bellaterra, Barcelona, 08193, Spain. .,Departament de Ciència Animal i dels Aliments, Facultat de Veterinària, Campus UAB, Bellaterra, Barcelona, 08193, Spain.
| | - Jordi Estellé
- INRA, UMR 1313, Génétique Animale et Biologie Intégrative, Jouy-en-Josas F, 78352, France. .,AgroParisTech, UMR 1313 Génétique Animale et Biologie Intégrative, Jouy-en-Josas F, 78352, France. .,CEA, DSV/iRCM/SREIT/LREG, Jouy-en-Josas F, 78352, France.
| | - Estefânia Alves
- Departamento de Mejora Genética Animal, INIA, Ctra. de la Coruña km. 7, Madrid, 28040, Spain.
| | - Josep M Folch
- Plant and Animal Genomics, Centre de Recerca en Agrigenòmica (Consorci CSIC-IRTA-UAB-UB), Edifici CRAG, Campus UAB, Bellaterra, Barcelona, 08193, Spain. .,Departament de Ciència Animal i dels Aliments, Facultat de Veterinària, Campus UAB, Bellaterra, Barcelona, 08193, Spain.
| | - Maria Ballester
- Plant and Animal Genomics, Centre de Recerca en Agrigenòmica (Consorci CSIC-IRTA-UAB-UB), Edifici CRAG, Campus UAB, Bellaterra, Barcelona, 08193, Spain. .,Departament de Ciència Animal i dels Aliments, Facultat de Veterinària, Campus UAB, Bellaterra, Barcelona, 08193, Spain.
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Cai Y, Lydic TA, Turkette T, Reid GE, Olson LK. Impact of alogliptin and pioglitazone on lipid metabolism in islets of prediabetic and diabetic Zucker Diabetic Fatty rats. Biochem Pharmacol 2015; 95:46-57. [PMID: 25801003 DOI: 10.1016/j.bcp.2015.03.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Accepted: 03/13/2015] [Indexed: 12/30/2022]
Abstract
Prolonged exposure of pancreatic beta (β) cells to elevated glucose and free fatty acids (FFA) as occurs in type 2 diabetes results in loss of β cell function and survival. In Zucker Diabetic Fatty (ZDF) rats, β cell failure is associated with increased triacylglyceride (TAG) synthesis and disruption of the glycerolipid/FFA (GL/FFA) cycle, a critical arm of glucose-stimulated insulin secretion (GSIS). The aim of this study was to determine the impact of activation of PPARγ and increased incretin action via dipeptidyl-peptidase inhibition using pioglitazone and/or alogliptin, respectively, on islet lipid metabolism in prediabetic and diabetic ZDF rats. Transition of control prediabetic ZDF rats to diabetes was associated with reduced plasma insulin levels, reduced islet insulin content and GSIS, reduced stearoyl-CoA desaturase 2 (SCD 2) expression, and increased islet TAG, diacylglyceride (DAG) and ceramides species containing saturated FA. Treatment of prediabetic ZDF rats with a combination of pioglitazone and alogliptin, but not individually, prevented the transition to diabetes and was associated with marked lowering of islet TAG and DAG levels. Pioglitazone and alogliptin, however, did not restore SCD2 expression, the degree of FA saturation in TAG, DAG or ceramides, islet insulin content, or lower ceramide levels. These findings are consistent with activation of PPARγ and increased incretin action working in concert to restore GL/FFA cycle in β cells of ZDF rats. Restoration of the GL/FFA cycle without correcting islet FA desaturation, production of islet ceramides, and/or insulin sensitivity, however, may place these islets at risk for β cell failure.
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Affiliation(s)
- Ying Cai
- Department of Physiology, Michigan State University, East Lansing, MI 48824, USA.
| | - Todd A Lydic
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA.
| | - Thomas Turkette
- Department of Physiology, Michigan State University, East Lansing, MI 48824, USA.
| | - Gavin E Reid
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA; Department of Chemistry, Michigan State University, East Lansing, MI 48824 USA.
| | - L Karl Olson
- Department of Physiology, Michigan State University, East Lansing, MI 48824, USA.
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118
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Purdy JG, Shenk T, Rabinowitz JD. Fatty acid elongase 7 catalyzes lipidome remodeling essential for human cytomegalovirus replication. Cell Rep 2015; 10:1375-85. [PMID: 25732827 PMCID: PMC4354725 DOI: 10.1016/j.celrep.2015.02.003] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Revised: 10/23/2014] [Accepted: 01/29/2015] [Indexed: 11/26/2022] Open
Abstract
Human cytomegalovirus (HCMV) infection rewires host cell metabolism, up-regulating flux from glucose into acetyl-CoA to feed fatty acid metabolism, with saturated very long-chain fatty acids (VLFCA) required for production of infectious virion progeny. The human genome encodes seven elongase enzymes (ELOVL) that extend long chain fatty acids into VLCFA. Here we identify ELOVL7 as pivotal for HCMV infection. HCMV induces ELOVL7 by more than 150-fold. This induction is dependent on mTOR and SREBP-1. ELOVL7 knockdown or mTOR inhibition impairs HCMV-induced fatty acid elongation, HCMV particle release, and infectivity per particle. ELOVL7 overexpression enhances HCMV replication. During HCMV infection, mTOR activity is maintained by the viral protein pUL38. Expression of pUL38 is sufficient to induce ELOVL7, and pUL38-deficient virus is partially defective in ELOVL7 induction and fatty acid elongation. Thus, through its ability to modulate mTOR and SREBP-1, HCMV induces ELOVL7 to synthesize the saturated VLCFA required for efficient virus replication.
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Affiliation(s)
- John G Purdy
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
| | - Thomas Shenk
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Joshua D Rabinowitz
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA; Department of Chemistry, Princeton University, Princeton, NJ 08544, USA.
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119
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Björkgren I, Gylling H, Turunen H, Huhtaniemi I, Strauss L, Poutanen M, Sipilä P. Imbalanced lipid homeostasis in the conditional Dicer1 knockout mouse epididymis causes instability of the sperm membrane. FASEB J 2014; 29:433-42. [DOI: 10.1096/fj.14-259382] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Ida Björkgren
- Department of PhysiologyInstitute of BiomedicineUniversity of TurkuTurkuFinland
- Turku Doctoral Programme of Biomedical SciencesTurkuFinland
| | - Helena Gylling
- Institute of Public Health and Clinical NutritionDepartment of Clinical NutritionUniversity of Eastern FinlandKuopioFinland
- Department of MedicineDivision of Internal MedicineUniversity of HelsinkiHelsinkiFinland
| | - Heikki Turunen
- Department of PhysiologyInstitute of BiomedicineUniversity of TurkuTurkuFinland
| | - Ilpo Huhtaniemi
- Institute of Reproductive and Developmental Biology, Imperial College London, Hammersmith CampusLondonUnited Kingdom
| | - Leena Strauss
- Department of PhysiologyInstitute of BiomedicineUniversity of TurkuTurkuFinland
- Turku Center for Disease ModelingUniversity of TurkuTurkuFinland
| | - Matti Poutanen
- Department of PhysiologyInstitute of BiomedicineUniversity of TurkuTurkuFinland
- Turku Center for Disease ModelingUniversity of TurkuTurkuFinland
- Institute of Medicine, Sahlgrenska AcademyUniversity of GothenburgGothenburgSweden
| | - Petra Sipilä
- Department of PhysiologyInstitute of BiomedicineUniversity of HelsinkiHelsinkiFinland
- Laboratory Animal CentreUniversity of HelsinkiHelsinkiFinland
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120
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Moon YA, Ochoa CR, Mitsche MA, Hammer RE, Horton JD. Deletion of ELOVL6 blocks the synthesis of oleic acid but does not prevent the development of fatty liver or insulin resistance. J Lipid Res 2014; 55:2597-605. [PMID: 25281760 PMCID: PMC4242452 DOI: 10.1194/jlr.m054353] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Elongation of very long chain fatty acid-like family member 6 (ELOVL6) is a fatty acyl elongase that performs the initial and rate-limiting condensing reaction required for microsomal elongation of long-chain fatty acids. Our previous in vitro studies suggested that ELOVL6 elongated long-chain saturated fatty acids and monounsaturated fatty acids with chain lengths of 12 to 16 carbons. Here, we describe the generation and phenotypic characterization of Elovl6−/− mice. As predicted from the in vitro studies, livers from Elovl6−/− mice accumulated palmitic (C16:0) and palmitoleic (C16:1, n-7) fatty acids and contained significantly less stearic (C18:0) and oleic (C18:1, n-9) acids, confirming that ELOVL6 is the only enzyme capable of elongating palmitate (C16:0). Unexpectedly, Elovl6−/− mice produced vaccenic acid (C18:1, n-7), the elongated product of palmitoleate (C16:1, n-7), suggesting that palmitoleate (C16:1, n-7) to vaccenate (C18:1, n-7) elongation was not specific to ELOVL6. The only detected consequence of deleting Elovl6−/− in mice was that their livers accumulated significantly more triglycerides than wild-type mice when fed a fat-free/high-carbohydrate diet. When mice were fed a high-fat diet or ELOVL6 was deleted in ob/ob mice, the absence of ELOVL6 did not alter the development of obesity, fatty liver, hyperglycemia, or hyperinsulinemia. Combined, these results suggest that palmitoleic (C16:1, n-7) and vaccenic (C18:1, n-7) acids can largely replace the roles of oleic acid (C18:1, n-9) in vivo and that the deletion of ELOVL6 does not protect mice from the development of hepatic steatosis or insulin resistance.
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Affiliation(s)
- Young-Ah Moon
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046
| | - Courtney R Ochoa
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046
| | - Matthew A Mitsche
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046
| | - Robert E Hammer
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046
| | - Jay D Horton
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046 Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046
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121
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Di Gregorio E, Borroni B, Giorgio E, Lacerenza D, Ferrero M, Lo Buono N, Ragusa N, Mancini C, Gaussen M, Calcia A, Mitro N, Hoxha E, Mura I, Coviello DA, Moon YA, Tesson C, Vaula G, Couarch P, Orsi L, Duregon E, Papotti MG, Deleuze JF, Imbert J, Costanzi C, Padovani A, Giunti P, Maillet-Vioud M, Durr A, Brice A, Tempia F, Funaro A, Boccone L, Caruso D, Stevanin G, Brusco A. ELOVL5 mutations cause spinocerebellar ataxia 38. Am J Hum Genet 2014; 95:209-17. [PMID: 25065913 DOI: 10.1016/j.ajhg.2014.07.001] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Accepted: 07/02/2014] [Indexed: 12/18/2022] Open
Abstract
Spinocerebellar ataxias (SCAs) are a heterogeneous group of autosomal-dominant neurodegenerative disorders involving the cerebellum and 23 different genes. We mapped SCA38 to a 56 Mb region on chromosome 6p in a SCA-affected Italian family by whole-genome linkage analysis. Targeted resequencing identified a single missense mutation (c.689G>T [p.Gly230Val]) in ELOVL5. Mutation screening of 456 independent SCA-affected individuals identified the same mutation in two further unrelated Italian families. Haplotyping showed that at least two of the three families shared a common ancestor. One further missense variant (c.214C>G [p.Leu72Val]) was found in a French family. Both missense changes affect conserved amino acids, are predicted to be damaging by multiple bioinformatics tools, and were not identified in ethnically matched controls or within variant databases. ELOVL5 encodes an elongase involved in the synthesis of polyunsaturated fatty acids of the ω3 and ω6 series. Arachidonic acid and docosahexaenoic acid, two final products of the enzyme, were reduced in the serum of affected individuals. Immunohistochemistry on control mice and human brain demonstrated high levels in Purkinje cells. In transfection experiments, subcellular localization of altered ELOVL5 showed a perinuclear distribution with a signal increase in the Golgi compartment, whereas the wild-type showed a widespread signal in the endoplasmic reticulum. SCA38 and SCA34 are examples of SCAs due to mutations in elongase-encoding genes, emphasizing the importance of fatty-acid metabolism in neurological diseases.
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Affiliation(s)
- Eleonora Di Gregorio
- Department of Medical Sciences, University of Torino, 10126 Torino, Italy; Medical Genetics Unit, Azienda Ospedaliera Universitaria Città della Salute e della Scienza, 10126 Torino, Italy
| | - Barbara Borroni
- Department of Neurology, University of Brescia, 25100 Brescia, Italy
| | - Elisa Giorgio
- Department of Medical Sciences, University of Torino, 10126 Torino, Italy
| | - Daniela Lacerenza
- Department of Medical Sciences, University of Torino, 10126 Torino, Italy
| | - Marta Ferrero
- Department of Medical Sciences, University of Torino, 10126 Torino, Italy
| | - Nicola Lo Buono
- Department of Medical Sciences, University of Torino, 10126 Torino, Italy
| | - Neftj Ragusa
- Department of Medical Sciences, University of Torino, 10126 Torino, Italy
| | - Cecilia Mancini
- Department of Medical Sciences, University of Torino, 10126 Torino, Italy
| | - Marion Gaussen
- Institut National de la Santé et de la Recherche Médicale U1127, 75013 Paris, France; Centre National de la Recherche Scientifique UMR 7225, 75013 Paris, France; Sorbonne Universités, Université Pierre et Marie Curie (Paris 6) UMR_S 1127, Institut du Cerveau et de la Moelle Épinière, 75013 Paris, France; Neurogenetics team, École Pratique des Hautes Études, HéSam Université, 75013 Paris, France
| | - Alessandro Calcia
- Department of Medical Sciences, University of Torino, 10126 Torino, Italy
| | - Nico Mitro
- Department of Pharmacological and Biomolecular Sciences, University of Milano, 20133 Milano, Italy
| | - Eriola Hoxha
- Neuroscience Institute Cavalieri Ottolenghi, University of Torino, 10043 Orbassano, Italy
| | - Isabella Mura
- Laboratory of Human Genetics, Galliera Hospital, 16128 Genova, Italy
| | | | - Young-Ah Moon
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA
| | - Christelle Tesson
- Institut National de la Santé et de la Recherche Médicale U1127, 75013 Paris, France; Centre National de la Recherche Scientifique UMR 7225, 75013 Paris, France; Sorbonne Universités, Université Pierre et Marie Curie (Paris 6) UMR_S 1127, Institut du Cerveau et de la Moelle Épinière, 75013 Paris, France; Neurogenetics team, École Pratique des Hautes Études, HéSam Université, 75013 Paris, France
| | - Giovanna Vaula
- Neurologic Division 1, Department of Neuroscience and Mental Health, Azienda Ospedaliera Universitaria Città della Salute e della Scienza, 10126 Torino, Italy
| | - Philippe Couarch
- Institut National de la Santé et de la Recherche Médicale U1127, 75013 Paris, France; Centre National de la Recherche Scientifique UMR 7225, 75013 Paris, France; Sorbonne Universités, Université Pierre et Marie Curie (Paris 6) UMR_S 1127, Institut du Cerveau et de la Moelle Épinière, 75013 Paris, France
| | - Laura Orsi
- Neurologic Division 1, Department of Neuroscience and Mental Health, Azienda Ospedaliera Universitaria Città della Salute e della Scienza, 10126 Torino, Italy
| | - Eleonora Duregon
- Department of Oncology, University of Torino at San Luigi Hospital, 10043 Orbassano, Italy
| | - Mauro Giulio Papotti
- Department of Oncology, University of Torino at San Luigi Hospital, 10043 Orbassano, Italy
| | | | - Jean Imbert
- Transcriptomic and Genomic Marseille-Luminy platform, Technological Advances for Genomics and Clinics Laboratory, Institut National de la Santé et de la Recherche Médicale UMR_S 1090, Aix-Marseille University, 13009 Marseille, France
| | - Chiara Costanzi
- Department of Neurology, University of Brescia, 25100 Brescia, Italy
| | | | - Paola Giunti
- Department of Molecular Neuroscience, University College London Institute of Neurology, WC1 N3BG London, UK
| | | | - Alexandra Durr
- Institut National de la Santé et de la Recherche Médicale U1127, 75013 Paris, France; Centre National de la Recherche Scientifique UMR 7225, 75013 Paris, France; Sorbonne Universités, Université Pierre et Marie Curie (Paris 6) UMR_S 1127, Institut du Cerveau et de la Moelle Épinière, 75013 Paris, France; Fédération de Génétique, Pitié-Salpêtrière Hospital, Assistance Publique - Hôpitaux de Paris, 75013 Paris, France
| | - Alexis Brice
- Institut National de la Santé et de la Recherche Médicale U1127, 75013 Paris, France; Centre National de la Recherche Scientifique UMR 7225, 75013 Paris, France; Sorbonne Universités, Université Pierre et Marie Curie (Paris 6) UMR_S 1127, Institut du Cerveau et de la Moelle Épinière, 75013 Paris, France; Fédération de Génétique, Pitié-Salpêtrière Hospital, Assistance Publique - Hôpitaux de Paris, 75013 Paris, France
| | - Filippo Tempia
- Neuroscience Institute Cavalieri Ottolenghi, University of Torino, 10043 Orbassano, Italy
| | - Ada Funaro
- Department of Medical Sciences, University of Torino, 10126 Torino, Italy
| | - Loredana Boccone
- Ospedale Regionale Microcitemie, Azienda Unità Sanitaria Locale 8, 09121 Cagliari, Italy
| | - Donatella Caruso
- Neuroscience Institute Cavalieri Ottolenghi, University of Torino, 10043 Orbassano, Italy
| | - Giovanni Stevanin
- Institut National de la Santé et de la Recherche Médicale U1127, 75013 Paris, France; Centre National de la Recherche Scientifique UMR 7225, 75013 Paris, France; Sorbonne Universités, Université Pierre et Marie Curie (Paris 6) UMR_S 1127, Institut du Cerveau et de la Moelle Épinière, 75013 Paris, France; Neurogenetics team, École Pratique des Hautes Études, HéSam Université, 75013 Paris, France; Fédération de Génétique, Pitié-Salpêtrière Hospital, Assistance Publique - Hôpitaux de Paris, 75013 Paris, France
| | - Alfredo Brusco
- Department of Medical Sciences, University of Torino, 10126 Torino, Italy; Medical Genetics Unit, Azienda Ospedaliera Universitaria Città della Salute e della Scienza, 10126 Torino, Italy.
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Naganuma T, Kihara A. Two modes of regulation of the fatty acid elongase ELOVL6 by the 3-ketoacyl-CoA reductase KAR in the fatty acid elongation cycle. PLoS One 2014; 9:e101823. [PMID: 25003994 PMCID: PMC4086937 DOI: 10.1371/journal.pone.0101823] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Accepted: 06/12/2014] [Indexed: 01/13/2023] Open
Abstract
Fatty acids (FAs) are diverse molecules, and such diversity is important for lipids to exert their functions under several environmental conditions. FA elongation occurs at the endoplasmic reticulum and produces a variety of FA species; the FA elongation cycle consists of four distinct enzyme reactions. For this cycle to be driven efficiently, there must exist coordinated regulation of protein components of the FA elongation machinery. However, such regulation is poorly understood. In the present study, we performed biochemical analyses using the FA elongase ELOVL6 and the 3-ketoacyl-CoA reductase KAR, which catalyze the first and second steps of the FA elongation cycle, respectively. In vitro FA elongation assays using membrane fractions demonstrated that ELOVL6 activity was enhanced ∼10-fold in the presence of NADPH, although ELOVL6 itself did not require NADPH for its catalysis. On the other hand, KAR does use NADPH as a reductant in its enzyme reaction. Activity of purified ELOVL6 was enhanced by ∼3-fold in the presence of KAR. This effect was KAR enzyme activity-independent, since it was observed in the absence of NADPH and in the KAR mutant. However, ELOVL6 enzyme activity was further enhanced in a KAR enzyme activity-dependent manner. Therefore, KAR regulates ELOVL6 via two modes. In the first mode, KAR may induce conformational changes in ELOVL6 to become structure that can undergo catalysis. In the second mode, conversion of 3-ketoacyl-CoA to 3-hydroxyacyl-CoA by KAR may facilitate release of the product from the presumed ELOVL6–KAR complex.
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Affiliation(s)
- Tatsuro Naganuma
- Laboratory of Biochemistry, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan
| | - Akio Kihara
- Laboratory of Biochemistry, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan
- * E-mail:
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123
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Sassa T, Kihara A. Metabolism of very long-chain Fatty acids: genes and pathophysiology. Biomol Ther (Seoul) 2014; 22:83-92. [PMID: 24753812 PMCID: PMC3975470 DOI: 10.4062/biomolther.2014.017] [Citation(s) in RCA: 179] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Accepted: 03/03/2014] [Indexed: 01/19/2023] Open
Abstract
Fatty acids (FAs) are highly diverse in terms of carbon (C) chain-length and number of double bonds. FAs with C>20 are called very long-chain fatty acids (VLCFAs). VLCFAs are found not only as constituents of cellular lipids such as sphingolipids and glycerophospholipids but also as precursors of lipid mediators. Our understanding on the function of VLCFAs is growing in parallel with the identification of enzymes involved in VLCFA synthesis or degradation. A variety of inherited diseases, such as ichthyosis, macular degeneration, myopathy, mental retardation, and demyelination, are caused by mutations in the genes encoding VLCFA metabolizing enzymes. In this review, we describe mammalian VLCFAs by highlighting their tissue distribution and metabolic pathways, and we discuss responsible genes and enzymes with reference to their roles in pathophysiology.
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Affiliation(s)
- Takayuki Sassa
- Laboratory of Biochemistry, Faculty of Pharmaceutical Sciences, Hokkaido University, Kita-ku, Sapporo 060-0812, Japan
| | - Akio Kihara
- Laboratory of Biochemistry, Faculty of Pharmaceutical Sciences, Hokkaido University, Kita-ku, Sapporo 060-0812, Japan
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Tang N, Matsuzaka T, Suzuki M, Nakano Y, Zao H, Yokoo T, Suzuki-Kemuriyama N, Kuba M, Okajima Y, Takeuchi Y, Kobayashi K, Iwasaki H, Yatoh S, Takahashi A, Suzuki H, Sone H, Shimada M, Nakagawa Y, Yahagi N, Yamada N, Shimano H. Ablation of Elovl6 protects pancreatic islets from high-fat diet-induced impairment of insulin secretion. Biochem Biophys Res Commun 2014; 450:318-23. [PMID: 24938128 DOI: 10.1016/j.bbrc.2014.05.113] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Accepted: 05/24/2014] [Indexed: 10/25/2022]
Abstract
ELOVL family member 6, elongation of very long-chain fatty acids (Elovl6) is a microsomal enzyme that regulates the elongation of C12-16 saturated and monounsaturated fatty acids and is related to the development of obesity-induced insulin resistance via the modification of the fatty acid composition. In this study, we investigated the role of systemic Elovl6 in the pancreatic islet and β-cell function. Elovl6 is expressed in both islets and β-cell lines. In mice fed with chow, islets of the Elovl6(-/-) mice displayed normal architecture and β-cell mass compared with those of the wild-type mice. However, when fed a high-fat, high-sucrose (HFHS) diet, the islet hypertrophy in response to insulin resistance observed in normal mice was attenuated and glucose-stimulated insulin secretion (GSIS) increased in the islets of Elovl6(-/-) mice compared with those of the wild-type mice. Enhanced GSIS in the HFHS Elovl6(-/-) islets was associated with an increased ATP/ADP ratio and the suppression of ATF-3 expression. Our findings suggest that Elovl6 could be involved in insulin secretory capacity per β-cell and diabetes.
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Affiliation(s)
- Nie Tang
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Takashi Matsuzaka
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan.
| | - Marii Suzuki
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Yuta Nakano
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Hui Zao
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Tomotaka Yokoo
- Experimental Animal Laboratory, Research Center for Genomic Medicine, Saitama Medical University, 1397-1 Yamane, Hidaka City, Saitama 350-1241, Japan
| | - Noriko Suzuki-Kemuriyama
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Motoko Kuba
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Yuka Okajima
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Yoshinori Takeuchi
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Kazuto Kobayashi
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Hitoshi Iwasaki
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Shigeru Yatoh
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Akimitsu Takahashi
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Hiroaki Suzuki
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Hirohito Sone
- Department of Internal Medicine, Faculty of Medicine, Niigata University, 1-754 Asahimachi, Niigata, Niigata 951-8510, Japan
| | - Masako Shimada
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Yoshimi Nakagawa
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Naoya Yahagi
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Nobuhiro Yamada
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Hitoshi Shimano
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
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Sunaga H, Matsui H, Ueno M, Maeno T, Iso T, Syamsunarno MRAA, Anjo S, Matsuzaka T, Shimano H, Yokoyama T, Kurabayashi M. Deranged fatty acid composition causes pulmonary fibrosis in Elovl6-deficient mice. Nat Commun 2014; 4:2563. [PMID: 24113622 DOI: 10.1038/ncomms3563] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Accepted: 09/04/2013] [Indexed: 11/09/2022] Open
Abstract
Despite the established role of alveolar type II epithelial cells for the maintenance of pulmonary function, little is known about the deregulation of lipid composition in the pathogenesis of pulmonary fibrosis. The elongation of long-chain fatty acids family member 6 (Elovl6) is a rate-limiting enzyme catalysing the elongation of saturated and monounsaturated fatty acids. Here we show that Elovl6 expression is significantly downregulated after an intratracheal instillation of bleomycin (BLM) and in human lung with idiopathic pulmonary fibrosis. Elovl6-deficient (Elovl6⁻/⁻) mice treated with BLM exhibit severe fibroproliferative response and derangement of fatty acid profile compared with wild-type mice. Furthermore, Elovl6 knockdown induces a change in fatty acid composition similar to that in Elovl6⁻/⁻ mice, resulting in induction of apoptosis, TGF-β1 expression and reactive oxygen species generation. Our findings demonstrate a previously unappreciated role for Elovl6 in the regulation of lung homeostasis, and in pathogenesis and exacerbation of BLM-induced pulmonary fibrosis.
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Affiliation(s)
- Hiroaki Sunaga
- 1] Department of Laboratory Sciences, Gunma University Graduate School of Health Sciences, 3-39-22, Showa-machi, Maebashi 371-8514, Japan [2]
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Wallner S, Grandl M, Konovalova T, Sigrüner A, Kopf T, Peer M, Orsó E, Liebisch G, Schmitz G. Monocyte to macrophage differentiation goes along with modulation of the plasmalogen pattern through transcriptional regulation. PLoS One 2014; 9:e94102. [PMID: 24714687 PMCID: PMC3979739 DOI: 10.1371/journal.pone.0094102] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Accepted: 03/10/2014] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Dysregulation of monocyte-macrophage differentiation is a hallmark of vascular and metabolic diseases and associated with persistent low grade inflammation. Plasmalogens represent ether lipids that play a role in diabesity and previous data show diminished plasmalogen levels in obese subjects. We therefore analyzed transcriptomic and lipidomic changes during monocyte-macrophage differentiation in vitro using a bioinformatic approach. METHODS Elutriated monocytes from 13 healthy donors were differentiated in vitro to macrophages using rhM-CSF under serum-free conditions. Samples were taken on days 0, 1, 4 and 5 and analyzed for their lipidomic and transcriptomic profiles. RESULTS Gene expression analysis showed strong regulation of lipidome-related transcripts. Enzymes involved in fatty acid desaturation and elongation were increasingly expressed, peroxisomal and ER stress related genes were induced. Total plasmalogen levels remained unchanged, while the PE plasmalogen species pattern became more similar to circulating granulocytes, showing decreases in PUFA and increases in MUFA. A partial least squares discriminant analysis (PLS/DA) revealed that PE plasmalogens discriminate the stage of monocyte-derived macrophage differentiation. Partial correlation analysis could predict novel potential key nodes including DOCK1, PDK4, GNPTAB and FAM126A that might be involved in regulating lipid and especially plasmalogen homeostasis during differentiation. An in silico transcription analysis of lipid related regulation revealed known motifs such as PPAR-gamma and KLF4 as well as novel candidates such as NFY, RNF96 and Zinc-finger proteins. CONCLUSION Monocyte to macrophage differentiation goes along with profound changes in the lipid-related transcriptome. This leads to an induction of fatty-acid desaturation and elongation. In their PE-plasmalogen profile macrophages become more similar to granulocytes than monocytes, indicating terminal phagocytic differentiation. Therefore PE plasmalogens may represent potential biomarkers for cell activation. For the underlying transcriptional network we were able to predict a range of novel central key nodes and underlying transcription factors using a bioinformatic approach.
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Affiliation(s)
- Stefan Wallner
- Institute of Clinical Chemistry and Laboratory Medicine, University Hospital Regensburg, University of Regensburg, Regensburg, Germany
| | - Margot Grandl
- Institute of Clinical Chemistry and Laboratory Medicine, University Hospital Regensburg, University of Regensburg, Regensburg, Germany
| | - Tatiana Konovalova
- Institute of Clinical Chemistry and Laboratory Medicine, University Hospital Regensburg, University of Regensburg, Regensburg, Germany
| | - Alexander Sigrüner
- Institute of Clinical Chemistry and Laboratory Medicine, University Hospital Regensburg, University of Regensburg, Regensburg, Germany
| | - Thomas Kopf
- Institute of Clinical Chemistry and Laboratory Medicine, University Hospital Regensburg, University of Regensburg, Regensburg, Germany
| | - Markus Peer
- Institute of Clinical Chemistry and Laboratory Medicine, University Hospital Regensburg, University of Regensburg, Regensburg, Germany
| | - Evelyn Orsó
- Institute of Clinical Chemistry and Laboratory Medicine, University Hospital Regensburg, University of Regensburg, Regensburg, Germany
| | - Gerhard Liebisch
- Institute of Clinical Chemistry and Laboratory Medicine, University Hospital Regensburg, University of Regensburg, Regensburg, Germany
| | - Gerd Schmitz
- Institute of Clinical Chemistry and Laboratory Medicine, University Hospital Regensburg, University of Regensburg, Regensburg, Germany
- * E-mail:
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127
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Kerner J, Minkler PE, Lesnefsky EJ, Hoppel CL. Fatty acid chain elongation in palmitate-perfused working rat heart: mitochondrial acetyl-CoA is the source of two-carbon units for chain elongation. J Biol Chem 2014; 289:10223-34. [PMID: 24558043 DOI: 10.1074/jbc.m113.524314] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Rat hearts were perfused with [1,2,3,4-(13)C4]palmitic acid (M+4), and the isotopic patterns of myocardial acylcarnitines and acyl-CoAs were analyzed using ultra-HPLC-MS/MS. The 91.2% (13)C enrichment in palmitoylcarnitine shows that little endogenous (M+0) palmitate contributed to its formation. The presence of M+2 myristoylcarnitine (95.7%) and M+2 acetylcarnitine (19.4%) is evidence for β-oxidation of perfused M+4 palmitic acid. Identical enrichment data were obtained in the respective acyl-CoAs. The relative (13)C enrichment in M+4 (84.7%, 69.9%) and M+6 (16.2%, 17.8%) stearoyl- and arachidylcarnitine, respectively, clearly shows that the perfused palmitate is chain-elongated. The observed enrichment of (13)C in acetylcarnitine (19%), M+6 stearoylcarnitine (16.2%), and M+6 arachidylcarnitine (17.8%) suggests that the majority of two-carbon units for chain elongation are derived from β-oxidation of [1,2,3,4-(13)C4]palmitic acid. These data are explained by conversion of the M+2 acetyl-CoA to M+2 malonyl-CoA, which serves as the acceptor for M+4 palmitoyl-CoA in chain elongation. Indeed, the (13)C enrichment in mitochondrial acetyl-CoA (18.9%) and malonyl-CoA (19.9%) are identical. No (13)C enrichment was found in acylcarnitine species with carbon chain lengths between 4 and 12, arguing against the simple reversal of fatty acid β-oxidation. Furthermore, isolated, intact rat heart mitochondria 1) synthesize malonyl-CoA with simultaneous inhibition of carnitine palmitoyltransferase 1b and 2) catalyze the palmitoyl-CoA-dependent incorporation of (14)C from [2-(14)C]malonyl-CoA into lipid-soluble products. In conclusion, rat heart has the capability to chain-elongate fatty acids using mitochondria-derived two-carbon chain extenders. The data suggest that the chain elongation process is localized on the outer surface of the mitochondrial outer membrane.
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128
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Pauter AM, Olsson P, Asadi A, Herslöf B, Csikasz RI, Zadravec D, Jacobsson A. Elovl2 ablation demonstrates that systemic DHA is endogenously produced and is essential for lipid homeostasis in mice. J Lipid Res 2014; 55:718-28. [PMID: 24489111 PMCID: PMC3966705 DOI: 10.1194/jlr.m046151] [Citation(s) in RCA: 96] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The potential role of endogenously synthesized PUFAs is a highly overlooked area. Elongation of very long-chain fatty acids (ELOVLs) in mammals is catalyzed by the ELOVL enzymes to which the PUFA elongase ELOVL2 belongs. To determine its in vivo function, we have investigated how ablation of ELOVL2, which is highly expressed in liver, affects hepatic lipid composition and function in mice. The Elovl2(-/-) mice displayed substantially decreased levels of 22:6(n-3), DHA, and 22:5(n-6), docosapentaenoic acid (DPA) n-6, and an accumulation of 22:5(n-3) and 22:4(n-6) in both liver and serum, showing that ELOVL2 primarily controls the elongation process of PUFAs with 22 carbons to produce 24-carbon precursors for DHA and DPAn-6 formation in vivo. The impaired PUFA levels positively influenced hepatic levels of the key lipogenic transcriptional regulator sterol-regulatory element binding protein 1c (SREBP-1c), as well as its downstream target genes. Surprisingly, the Elovl2(-/-) mice were resistant to hepatic steatosis and diet-induced weight gain, implying that hepatic DHA synthesis via ELOVL2, in addition to controlling de novo lipogenesis, also regulates lipid storage and fat mass expansion in an SREBP-1c-independent fashion. The changes in fatty acid metabolism were reversed by dietary supplementation with DHA.
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Affiliation(s)
- Anna M Pauter
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, SE-10691 Stockholm, Sweden; and
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129
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Carobbio S, Hagen RM, Lelliott CJ, Slawik M, Medina-Gomez G, Tan CY, Sicard A, Atherton HJ, Barbarroja N, Bjursell M, Bohlooly-Y M, Virtue S, Tuthill A, Lefai E, Laville M, Wu T, Considine RV, Vidal H, Langin D, Oresic M, Tinahones FJ, Fernandez-Real JM, Griffin JL, Sethi JK, López M, Vidal-Puig A. Adaptive changes of the Insig1/SREBP1/SCD1 set point help adipose tissue to cope with increased storage demands of obesity. Diabetes 2013; 62:3697-708. [PMID: 23919961 PMCID: PMC3806615 DOI: 10.2337/db12-1748] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The epidemic of obesity imposes unprecedented challenges on human adipose tissue (WAT) storage capacity that may benefit from adaptive mechanisms to maintain adipocyte functionality. Here, we demonstrate that changes in the regulatory feedback set point control of Insig1/SREBP1 represent an adaptive response that preserves WAT lipid homeostasis in obese and insulin-resistant states. In our experiments, we show that Insig1 mRNA expression decreases in WAT from mice with obesity-associated insulin resistance and from morbidly obese humans and in in vitro models of adipocyte insulin resistance. Insig1 downregulation is part of an adaptive response that promotes the maintenance of SREBP1 maturation and facilitates lipogenesis and availability of appropriate levels of fatty acid unsaturation, partially compensating the antilipogenic effect associated with insulin resistance. We describe for the first time the existence of this adaptive mechanism in WAT, which involves Insig1/SREBP1 and preserves the degree of lipid unsaturation under conditions of obesity-induced insulin resistance. These adaptive mechanisms contribute to maintain lipid desaturation through preferential SCD1 regulation and facilitate fat storage in WAT, despite on-going metabolic stress.
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Affiliation(s)
- Stefania Carobbio
- University of Cambridge, Metabolic Research Laboratories, Institute of Metabolic Science Addenbrooke's Treatment Centre, Addenbrooke's Hospital, Cambridge, U.K
| | - Rachel M. Hagen
- University of Cambridge, Metabolic Research Laboratories, Institute of Metabolic Science Addenbrooke's Treatment Centre, Addenbrooke's Hospital, Cambridge, U.K
| | | | - Marc Slawik
- University of Cambridge, Metabolic Research Laboratories, Institute of Metabolic Science Addenbrooke's Treatment Centre, Addenbrooke's Hospital, Cambridge, U.K
- Endocrine Research Unit, Medizinische Klinik-Innenstadt, Ludwig-Maximilians University, Munich, Germany
| | - Gema Medina-Gomez
- University of Cambridge, Metabolic Research Laboratories, Institute of Metabolic Science Addenbrooke's Treatment Centre, Addenbrooke's Hospital, Cambridge, U.K
- Departamento de Bioquímica, Fisiología y Genética Molecular, Universidad Rey Juan Carlos Facultad de Ciencias de la Salud Avda.de Atenas s/n28922 Alcorcón, Madrid, Spain
| | - Chong-Yew Tan
- University of Cambridge, Metabolic Research Laboratories, Institute of Metabolic Science Addenbrooke's Treatment Centre, Addenbrooke's Hospital, Cambridge, U.K
| | - Audrey Sicard
- INSERM, Paul Sabatier University, UMR1048, Institute of Metabolic and Cardiovascular Diseases (I2MC), Laboratory of Obesity, Toulouse, France
| | - Helen J. Atherton
- MRC Human Nutrition Research, Elsie Widdowson Laboratory & University of Cambridge, Department of Biochemistry, Cambridge, U.K
| | - Nuria Barbarroja
- University of Cambridge, Metabolic Research Laboratories, Institute of Metabolic Science Addenbrooke's Treatment Centre, Addenbrooke's Hospital, Cambridge, U.K
- Hospital Virgen de la Victoria, CIBER Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Malaga, Spain
| | - Mikael Bjursell
- Department of Biosciences, CVGI iMED, AstraZeneca Research and Development, Mölndal, Sweden
| | - Mohammad Bohlooly-Y
- Department of Biosciences, CVGI iMED, AstraZeneca Research and Development, Mölndal, Sweden
| | - Sam Virtue
- University of Cambridge, Metabolic Research Laboratories, Institute of Metabolic Science Addenbrooke's Treatment Centre, Addenbrooke's Hospital, Cambridge, U.K
| | - Antoinette Tuthill
- University of Cambridge, Metabolic Research Laboratories, Institute of Metabolic Science Addenbrooke's Treatment Centre, Addenbrooke's Hospital, Cambridge, U.K
| | - Etienne Lefai
- INSERM U-1060; INRA U-1235; Human Nutrition Research Center of Lyon CarMeN Laboratory, Lyon1 University, Lyon, France
| | - Martine Laville
- INSERM U-1060; INRA U-1235; Human Nutrition Research Center of Lyon CarMeN Laboratory, Lyon1 University, Lyon, France
| | - Tingting Wu
- Department of Biosciences, CVGI iMED, AstraZeneca Research and Development, Mölndal, Sweden
| | - Robert V. Considine
- Division of Endocrinology and Metabolism, Indiana University School of Medicine, Indianapolis, Indiana
| | - Hubert Vidal
- INSERM U-1060; INRA U-1235; Human Nutrition Research Center of Lyon CarMeN Laboratory, Lyon1 University, Lyon, France
| | - Dominique Langin
- INSERM, Paul Sabatier University, UMR1048, Institute of Metabolic and Cardiovascular Diseases (I2MC), Laboratory of Obesity, Toulouse, France
- Laboratory of Clinical Biochemistry, Toulouse, France
| | - Matej Oresic
- Department of Medicine, Division of Internal Medicine, and Department of Psychiatry, Obesity Research Unit, Helsinki University Central Hospital, Helsinki, Finland
| | - Francisco J. Tinahones
- Hospital Virgen de la Victoria, CIBER Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Malaga, Spain
| | - Jose Manuel Fernandez-Real
- Department of Diabetes, Endocrinology and Nutrition, Institut d'Investigació Biomédica de Girona, CIBERobn Fisiopatología de la Obesidad y Nutrición CB06/03/010, Girona, Spain
| | - Julian L. Griffin
- MRC Human Nutrition Research, Elsie Widdowson Laboratory & University of Cambridge, Department of Biochemistry, Cambridge, U.K
| | - Jaswinder K. Sethi
- University of Cambridge, Metabolic Research Laboratories, Institute of Metabolic Science Addenbrooke's Treatment Centre, Addenbrooke's Hospital, Cambridge, U.K
| | - Miguel López
- University of Cambridge, Metabolic Research Laboratories, Institute of Metabolic Science Addenbrooke's Treatment Centre, Addenbrooke's Hospital, Cambridge, U.K
- Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela, Spain
| | - Antonio Vidal-Puig
- University of Cambridge, Metabolic Research Laboratories, Institute of Metabolic Science Addenbrooke's Treatment Centre, Addenbrooke's Hospital, Cambridge, U.K
- Wellcome Trust Sanger Institute, Hinxton, Cambridge, U.K
- Corresponding author: Antonio Vidal-Puig,
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Kosters A, Sun D, Wu H, Tian F, Felix JC, Li W, Karpen SJ. Sexually dimorphic genome-wide binding of retinoid X receptor alpha (RXRα) determines male-female differences in the expression of hepatic lipid processing genes in mice. PLoS One 2013; 8:e71538. [PMID: 23977068 PMCID: PMC3747242 DOI: 10.1371/journal.pone.0071538] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2013] [Accepted: 06/28/2013] [Indexed: 02/06/2023] Open
Abstract
Many hepatic functions including lipid metabolism, drug metabolism, and inflammatory responses are regulated in a sex-specific manner due to distinct patterns of hepatic gene expression between males and females. Regulation for the majority of these genes is under control of Nuclear Receptors (NRs). Retinoid X Receptor alpha (RXRα) is an obligate partner for multiple NRs and considered a master regulator of hepatic gene expression, yet the full extent of RXRα chromatin binding in male and female livers is unclear. ChIP-Seq analysis of RXRα and RNA Polymerase2 (Pol2) binding was performed livers of both genders and combined with microarray analysis. Mice were gavage-fed with the RXR ligand LG268 for 5 days (30 mg/kg/day) and RXRα-binding and RNA levels were determined by ChIP-qPCR and qPCR, respectively. ChIP-Seq revealed 47,845 (male) and 46,877 (female) RXRα binding sites (BS), associated with ∼12,700 unique genes in livers of both genders, with 91% shared between sexes. RXRα-binding showed significant enrichment for 2227 and 1498 unique genes in male and female livers, respectively. Correlating RXRα binding strength with Pol2-binding revealed 44 genes being male-dominant and 43 female-dominant, many previously unknown to be sexually-dimorphic. Surprisingly, genes fundamental to lipid metabolism, including Scd1, Fasn, Elovl6, and Pnpla3-implicated in Fatty Liver Disease pathogenesis, were predominant in females. RXRα activation using LG268 confirmed RXRα-binding was 2-3 fold increased in female livers at multiple newly identified RXRα BS including for Pnpla3 and Elovl6, with corresponding ∼10-fold and ∼2-fold increases in Pnpla3 and Elovl6 RNA respectively in LG268-treated female livers, supporting a role for RXRα regulation of sexually-dimorphic responses for these genes. RXRα appears to be one of the most widely distributed transcriptional regulators in mouse liver and is engaged in determining sexually-dimorphic expression of key lipid-processing genes, suggesting novel gender- and gene-specific responses to NR-based treatments for lipid-related liver diseases.
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Affiliation(s)
- Astrid Kosters
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Deqiang Sun
- Division of Biostatistics, Dan L. Duncan Cancer Center, Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas, United States of America
| | - Hao Wu
- Department of Biostatistics, School of Public Health, Emory University, Atlanta, Georgia, United States of America
| | - Feng Tian
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Julio C. Felix
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Wei Li
- Division of Biostatistics, Dan L. Duncan Cancer Center, Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas, United States of America
| | - Saul J. Karpen
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia, United States of America
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131
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Liu Y, Wang F, Yu XL, Miao ZM, Wang ZC, Chen Y, Wang YG. Genetic analysis of the ELOVL6 gene polymorphism associated with type 2 diabetes mellitus. Braz J Med Biol Res 2013; 46:623-8. [PMID: 23903678 PMCID: PMC3859333 DOI: 10.1590/1414-431x20133103] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Accepted: 05/15/2013] [Indexed: 11/24/2022] Open
Abstract
Recent animal studies have indicated that overexpression of the elongation of
long-chain fatty acids family member 6 (Elovl6) gene can cause
insulin resistance and β-cell dysfunction. These are the major factors involved
in the development of type 2 diabetes mellitus (T2DM). To identify the
relationship between single nucleotide polymorphisms (SNP) of
ELOVL6 and T2DM pathogenesis, we conducted a case-control
study of 610 Han Chinese individuals (328 newly diagnosed T2DM and 282 healthy
subjects). Insulin resistance and islet first-phase secretion function were
evaluated by assessment of insulin resistance in a homeostasis model (HOMA-IR)
and an arginine stimulation test. Three SNPs of the ELOVL6 gene
were genotyped with polymerase chain reaction-restriction fragment length
polymorphism, with DNA sequencing used to confirm the results. Only genotypes TT
and CT of the ELOVL6 SNP rs12504538 were detected in the
samples. Genotype CC was not observed. The T2DM group had a higher frequency of
the C allele and the CT genotype than the control group. Subjects with the CT
genotype had higher HOMA-IR values than those with the TT genotype. In addition,
no statistical significance was observed between the genotype and allele
frequencies of the control and T2DM groups for SNPs rs17041272 and rs6824447.
The study indicated that the ELOVL6 gene polymorphism
rs12504538 is associated with an increased risk of T2DM, because it causes an
increase in insulin resistance.
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Affiliation(s)
- Y Liu
- Qingdao University, Department of Endocrinology, The Affiliated Hospital of Medical College, China
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132
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Pena RN, Noguera JL, Casellas J, Díaz I, Fernández AI, Folch JM, Ibáñez-Escriche N. Transcriptional analysis of intramuscular fatty acid composition in the longissimus thoracis muscle of Iberian × Landrace back-crossed pigs. Anim Genet 2013; 44:648-60. [PMID: 23826865 DOI: 10.1111/age.12066] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/29/2013] [Indexed: 11/29/2022]
Abstract
This study aimed at identifying differential gene expression conditional on the fatty acid profile of the longissimus thoracis (Lt) muscle, a prime cut of economic relevance for fresh and cured pork production. A population of 110 Iberian (25%) × Landrace (75%) back-crossed pigs was used, because these two breeds exhibit extreme profiles of intramuscular saturated fatty acid, monounsaturated fatty acid (MUFA) and polyunsaturated fatty acid (PUFA) contents. Total RNA from Lt muscle was individually hybridized to GeneChip Porcine Genome arrays (Affymetrix). A principal component analysis was performed with data from the 110 animals to select 40 extreme animals based on the total fatty acid profile and the MUFA composition (MAP). Comparison of global transcription levels between extreme fatty acid profile pigs (n = 40) resulted in 219 differentially expressed probes (false discovery rate <0.10). Gene ontology, pathway and network analysis indicated that animals with higher percentages of PUFA exhibit a shift toward a more oxidative muscular metabolism state, with a raise in mitochondria function (PPARGC1A, ATF2), fatty acid uptake and oxidation (FABP5, MGLL). On the other hand, 87 probes were differentially expressed between MUFA composition groups (n = 40; false discovery rate <0.10). In particular, muscles rich in n-7 MUFA expressed higher levels of genes involved in lipid metabolism (GLUL, CRAT, PLA2G15) and lower levels of fatty acid elongation genes (ELOVL5). Moreover, the chromosomal position of FABP5, PAQR3, MGLL, PPARGC1A, GLUL and ELOVL5 co-localized with very relevant QTL for fat deposition and composition described in the same resource population. This study represents a complementary approach to identifying genes underlying these QTL effects.
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Affiliation(s)
- R N Pena
- Genètica i Millora Animal, IRTA, 191 Av. Rovira Roure, 25198, Lleida, Spain; Departament de Producció Animal, ETSEA, Universitat de Lleida, 191 Av. Rovira Roure, 25198, Lleida, Spain
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133
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Eissing L, Scherer T, Tödter K, Knippschild U, Greve JW, Buurman WA, Pinnschmidt HO, Rensen SS, Wolf AM, Bartelt A, Heeren J, Buettner C, Scheja L. De novo lipogenesis in human fat and liver is linked to ChREBP-β and metabolic health. Nat Commun 2013; 4:1528. [PMID: 23443556 DOI: 10.1038/ncomms2537] [Citation(s) in RCA: 228] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2012] [Accepted: 01/23/2013] [Indexed: 02/07/2023] Open
Abstract
Clinical interest in de novo lipogenesis has been sparked by recent studies in rodents demonstrating that de novo lipogenesis specifically in white adipose tissue produces the insulin-sensitizing fatty acid palmitoleate. By contrast, hepatic lipogenesis is thought to contribute to metabolic disease. How de novo lipogenesis in white adipose tissue versus liver is altered in human obesity and insulin resistance is poorly understood. Here we show that lipogenic enzymes and the glucose transporter-4 are markedly decreased in white adipose tissue of insulin-resistant obese individuals compared with non-obese controls. By contrast, lipogenic enzymes are substantially upregulated in the liver of obese subjects. Bariatric weight loss restored de novo lipogenesis and glucose transporter-4 gene expression in white adipose tissue. Notably, lipogenic gene expression in both white adipose tissue and liver was strongly linked to the expression of carbohydrate-responsive element-binding protein-β and to metabolic risk markers. Thus, de novo lipogenesis predicts metabolic health in humans in a tissue-specific manner and is likely regulated by glucose-dependent carbohydrate-responsive element-binding protein activation.
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Affiliation(s)
- Leah Eissing
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, D-20246 Hamburg, Germany
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134
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Increased dietary fat contributes to dysregulation of the LKB1/AMPK pathway and increased damage in a mouse model of early-stage ethanol-mediated steatosis. J Nutr Biochem 2013; 24:1436-45. [PMID: 23465594 DOI: 10.1016/j.jnutbio.2012.12.002] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2012] [Revised: 11/30/2012] [Accepted: 12/06/2012] [Indexed: 12/22/2022]
Abstract
OBJECTIVE The objective of the study was to examine the interaction of moderate and high dietary fat and ethanol with respect to formation of steatosis and regulation of the AMP-activated protein kinase (AMPK) pathway in a mouse model of chronic ethanol consumption. METHODS Male C57BL/6J mice were pair-fed a modified Lieber-DeCarli diet composed of either moderate fat [30% fat-derived calories (MF)] or high fat [45% fat-derived calories (HF)] combined with increasing concentrations of ethanol (2%-6%) for 6 weeks. RESULTS Chronic ethanol consumption resulted in significant increases in plasma alanine aminotransferase in MF (1.84-fold) and HF mice (2.33-fold), yet liver triglycerides only increased significantly in the HF model (1.62-fold). Ethanol addition significantly increased plasma adiponectin under conditions of MF but not HF. In combination with MF, the addition of ethanol significantly decreased total and hepatic pThr(172)AMPKα and acetyl CoA Carboxylase (ACC). HF plus ethanol decreased pSer(108)AMPKβ, yet a marked 1.5-fold increase in pThr(172)AMPKα occurred. No change was evident in pSer(79)ACC under conditions of ethanol and HF ingestion. In both models, nuclear levels of sterol response element binding protein 1c and carbohydrate response element binding protein were decreased. Surprisingly, MF plus ethanol significantly elevated protein expression of medium-chain acyl-CoA dehydrogenase (MCAD), long-chain acyl-CoA dehydrogenase (LCAD) and very long chain acyl-CoA dehydrogenase but did not significantly affect mRNA expression of other proteins involved in β-oxidation and fatty acid synthesis. HF plus ethanol significantly reduced mRNA expression of both stearoyl CoA desaturase 1 and fatty acid elongase 5, but did not have an effect on MCAD or LCAD. CONCLUSION These data suggest that, when co-ingested with ethanol, dietary fat differentially contributes to dysregulation of adiponectin-dependent activation of the AMPK pathway in the liver of mice.
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135
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Jiao J, Zhang Y. Transgenic Biosynthesis of Polyunsaturated Fatty Acids: A Sustainable Biochemical Engineering Approach for Making Essential Fatty Acids in Plants and Animals. Chem Rev 2013; 113:3799-814. [DOI: 10.1021/cr300007p] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Jingjing Jiao
- Chronic Disease Research Institute,
Department of Nutrition and Food Hygiene, School of Public Health,
Zhejiang University, Hangzhou 310058, China
| | - Yu Zhang
- Department of Food Science and
Nutrition, School of Biosystems Engineering and Food Science, Zhejiang
University, Hangzhou 310058, China
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136
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Chu X, Liu L, Na L, Lu H, Li S, Li Y, Sun C. Sterol regulatory element-binding protein-1c mediates increase of postprandial stearic acid, a potential target for improving insulin resistance, in hyperlipidemia. Diabetes 2013; 62:561-71. [PMID: 22966071 PMCID: PMC3554356 DOI: 10.2337/db12-0139] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Elevated serum free fatty acids (FFAs) levels play an important role in the development of insulin resistance (IR) and diabetes. We investigated the dynamic changes and the underlying regulatory mechanism of postprandial FFA profile in hyperlipidemia (HLP) and their relation with insulin sensitivity in both humans and mice. We found that serum stearic acid (SA) is the only fatty acid that is increased dramatically in the postprandial state. The elevation of SA is due to increased insulin-stimulated de novo synthesis mediated by sterol regulatory element-binding protein-1c (SREBP-1c)/acetyl-CoA carboxylase/fatty acid synthase/elongation of long-chain fatty acid family member 6 (ELOVL6) and the elongation of palmitic acid (PA) catalyzed by ELOVL6. Downregulation of SREBP-1c or ELOVL6 by small interfering RNA can reduce SA synthesis in liver and serum SA level, followed by amelioration of IR in HLP mice. However, inhibition of SREBP-1c is more effective in improving IR than suppression of ELOVL6, which resulted in accumulation of PA. In summary, increased postprandial SA is caused by the insulin-stimulated SREBP-1c pathway and elongation of PA in HLP. Reduction of postprandial SA is a good candidate for improving IR, and SREBP-1c is potentially a better target to prevent IR and diabetes by decreasing SA.
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Affiliation(s)
| | | | | | | | | | - Ying Li
- Corresponding authors: Changhao Sun, , and Ying Li,
| | - Changhao Sun
- Corresponding authors: Changhao Sun, , and Ying Li,
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137
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Corominas J, Ramayo-Caldas Y, Puig-Oliveras A, Pérez-Montarelo D, Noguera JL, Folch JM, Ballester M. Polymorphism in the ELOVL6 gene is associated with a major QTL effect on fatty acid composition in pigs. PLoS One 2013; 8:e53687. [PMID: 23341976 PMCID: PMC3544903 DOI: 10.1371/journal.pone.0053687] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2012] [Accepted: 12/03/2012] [Indexed: 11/21/2022] Open
Abstract
Background The ELOVL fatty acid elongase 6 (ELOVL6), the only elongase related to de novo lipogenesis, catalyzes the rate-limiting step in the elongation cycle by controlling the fatty acid balance in mammals. It is located on pig chromosome 8 (SSC8) in a region where a QTL affecting palmitic, and palmitoleic acid composition was previously detected, using an Iberian x Landrace intercross. The main goal of this work was to fine-map the QTL and to evaluate the ELOVL6 gene as a positional candidate gene affecting the percentages of palmitic and palmitoleic fatty acids in pigs. Methodology and Principal Findings The combination of a haplotype-based approach and single-marker analysis allowed us to identify the main, associated interval for the QTL, in which the ELOVL6 gene was identified and selected as a positional candidate gene. A polymorphism in the promoter region of ELOVL6, ELOVL6:c.-533C>T, was highly associated with the percentage of palmitic and palmitoleic acids in muscle and backfat. Significant differences in ELOVL6 gene expression were observed in backfat when animals were classified by the ELOVL6:c.-533C>T genotype. Accordingly, animals carrying the allele associated with a decrease in ELOVL6 gene expression presented an increase in C16:0 and C16:1(n-7) fatty acid content and a decrease of elongation activity ratios in muscle and backfat. Furthermore, a SNP genome-wide association study with ELOVL6 relative expression levels in backfat showed the strongest effect on the SSC8 region in which the ELOVL6 gene is located. Finally, different potential genomic regions associated with ELOVL6 gene expression were also identified by GWAS in liver and muscle, suggesting a differential tissue regulation of the ELOVL6 gene. Conclusions and Significance Our results suggest ELOVL6 as a potential causal gene for the QTL analyzed and, subsequently, for controlling the overall balance of fatty acid composition in pigs.
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Affiliation(s)
- Jordi Corominas
- Departament de Genètica Animal, Centre de Recerca en Agrigenòmica, Bellaterra, Spain.
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138
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Yu K, Shu G, Yuan F, Zhu X, Gao P, Wang S, Wang L, Xi Q, Zhang S, Zhang Y, Li Y, Wu T, Yuan L, Jiang Q. Fatty acid and transcriptome profiling of longissimus dorsi muscles between pig breeds differing in meat quality. Int J Biol Sci 2013; 9:108-18. [PMID: 23355796 PMCID: PMC3555150 DOI: 10.7150/ijbs.5306] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Accepted: 12/24/2012] [Indexed: 11/09/2022] Open
Abstract
Fat and lean pig breeds show obvious differences in meat quality characteristics including the fatty acid composition of muscle. However, the molecular mechanism underlying these phenotypes differences remains unknown. This study compared meat quality traits between Lantang (a Chinese indigenous breed) and Landrace (a typical lean breed). The Lantang pigs showed higher L* values and intramuscular fat content, lower pH45min, pH24h and shear force in longissimus dorsi (LD) muscle than Landrace (P < 0.05). Fatty acid analysis demonstrated the lower monounsaturated fatty acids (MUFA) and higher polyunsaturated fatty acids (PUFA) percentage in Lantang LD than that in Landrace LD (P < 0.05). To further identify candidate genes for fatty acid composition, the transcriptome of LD muscle from the two breeds were measured by microarrays. There were 586 transcripts differentially expressed, of which 267 transcripts were highly expressed in Lantang pigs. After the validation by real-time quantitative PCR, 13 genes were determined as candidate genes for fatty acid composition of muscle, including Stearoyl-CoA desaturase (SCD). Then, a SCD over-expression plasmid was transfected into C2C12 cells to reveal the effect of SCD on the fatty acid composition in vitro. The results showed that SCD over-expression significantly increased PUFA proportion, while reduced that of saturated fatty acids (SFA) in C2C12 cells (P < 0.05). In summary, this study compared the differences of fatty acid composition and transcriptome in two breeds differing in meat quality, and further identified the novel role of SCD in the regulation of PUFA deposition.
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Affiliation(s)
- Kaifan Yu
- College of Animal Science, South China Agricultural University, Guangdong province, Guangzhou 510642, China
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139
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Dong XY, Tang SQ, Chen JD. Dual functions of Insig proteins in cholesterol homeostasis. Lipids Health Dis 2012; 11:173. [PMID: 23249523 PMCID: PMC3564778 DOI: 10.1186/1476-511x-11-173] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Accepted: 12/05/2012] [Indexed: 01/29/2023] Open
Abstract
The molecular mechanism of how cells maintain cholesterol homeostasis has become clearer for the understanding of complicated association between sterol regulatory element-binding proteins (SREBPs), SREBP cleavage-activating protein (SCAP), 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMG-CoA reductase) and Insuin induced-genes (Insigs). The pioneering researches suggested that SREBP activated the transcription of genes encoding HMG-CoA reductase and all of the other enzymes involved in the synthesis of cholesterol and lipids. However, SREBPs can not exert their activities alone, they must form a complex with another protein, SCAP in the endoplasmic reticulum (ER) and translocate to Golgi. Insigs are sensors and mediators that regulate cholesterol homeostasis through binding to SCAP and HMG-CoA reductase in diverse tissues such as adipose tissue and liver, as well as the cultured cells. In this article, we aim to review on the dual functions of Insig protein family in cholesterol homeostasis.
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Affiliation(s)
- Xiao-Ying Dong
- College of Veterinary Medicine, South China Agricultural University, No,483 Wu Shan Road, Tian He District, Guangzhou, 510642, China.
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140
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Matsuzaka T, Atsumi A, Matsumori R, Nie T, Shinozaki H, Suzuki-Kemuriyama N, Kuba M, Nakagawa Y, Ishii K, Shimada M, Kobayashi K, Yatoh S, Takahashi A, Takekoshi K, Sone H, Yahagi N, Suzuki H, Murata S, Nakamuta M, Yamada N, Shimano H. Elovl6 promotes nonalcoholic steatohepatitis. Hepatology 2012; 56:2199-208. [PMID: 22753171 DOI: 10.1002/hep.25932] [Citation(s) in RCA: 130] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/25/2011] [Accepted: 06/11/2012] [Indexed: 12/16/2022]
Abstract
UNLABELLED Nonalcoholic steatohepatitis (NASH) is associated with obesity and type 2 diabetes, and an increased risk for liver cirrhosis and cancer. ELOVL family member 6, elongation of very long chain fatty acids (Elovl6), is a microsomal enzyme that regulates the elongation of C12-16 saturated and monounsaturated fatty acids (FAs). We have shown previously that Elovl6 is a major target for sterol regulatory element binding proteins in the liver and that it plays a critical role in the development of obesity-induced insulin resistance by modifying FA composition. To further investigate the role of Elovl6 in the development of NASH and its underlying mechanism, we used three independent mouse models with loss or gain of function of Elovl6, and human liver samples isolated from patients with NASH. Our results demonstrate that (1) Elovl6 is a critical modulator for atherogenic high-fat diet-induced inflammation, oxidative stress, and fibrosis in the liver; (2) Elovl6 expression is positively correlated with severity of hepatosteatosis and liver injury in NASH patients; and (3) deletion of Elovl6 reduces palmitate-induced activation of the NLR family pyrin domain-containing 3 inflammasome; this could be at least one of the underlying mechanisms by which Elovl6 modulates the progress of NASH. CONCLUSION Hepatic long-chain fatty acid composition is a novel determinant in NASH development, and Elovl6 could be a potential therapeutic target for the prevention and treatment of NASH.
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Affiliation(s)
- Takashi Matsuzaka
- Department of Endocrinology and Metabolism, University of Tsukuba, Tsukuba, Japan
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141
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Abstract
Nonalcoholic fatty liver disease is becoming an epidemic. Fat is typically stored in adipose tissue in the form of triglycerides (TGs). The deposition of TGs in the liver is the result of an imbalance between the amount of energy taken in and the amount used. This balance is maintained by a complex interplay between the dietary intake of nutrients, the hormonal response to the nutrients, and their effect on both the liver and adipose tissue. Disruption of this system is what leads to the development of steatosis and is the focus of this article.
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Affiliation(s)
- Scott C Matherly
- Division of Gastroenterology, Hepatology and Nutrition, Department of Internal Medicine, Virginia Commonwealth University Medical Center, Richmond, 23298, USA
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142
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Tu WC, Mühlhäusler BS, James MJ, Stone DAJ, Gibson RA. An alternative n-3 fatty acid elongation pathway utilising 18:3n-3 in barramundi (Lates calcarifer). Biochem Biophys Res Commun 2012; 423:176-82. [PMID: 22640739 DOI: 10.1016/j.bbrc.2012.05.110] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Accepted: 05/18/2012] [Indexed: 10/28/2022]
Abstract
Desaturase and elongase are two key enzyme categories in the long-chain polyunsaturated fatty acid (LCPUFA) pathway that convert dietary α-linolenic acid (18:3n-3) to docosahexaenoic acid (22:6n-3). The Δ6 desaturase is considered as rate limiting in the conversion. In a previous study in barramundi we demonstrated that the desaturase had a low Δ6 activity but noted that the enzyme also possessed Δ8 ability that utilised 20-carbon fatty acids. This observation suggests that an alternative pathway may exist in the barramundi via elongases to form 20-carbon metabolites from 18:3n-3 to 20:3n-3 and then Δ6/8 desaturase to 20:4n-3. Cloning of the barramundi elongation of very long-chain fatty acid gene (ELOVL) and heterologous expression of the corresponding elongase were performed to examine activity with regard to time course, substrate concentration and substrate preference. Results revealed that the barramundi elongase showed a broad range of substrate specificity including 18-carbon PUFA (including 18:3n-3 and 18:2n-6), 20- and 22-carbon LCPUFA, with greater activity towards omega-3 (n-3) than n-6 fatty acids. The findings from this study provide molecular evidence for an alternative n-3 fatty acid elongation pathway utilising 18:3n-3 in barramundi.
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Affiliation(s)
- Wei-Chun Tu
- FOODplus Research Centre, School of Agriculture, Food and Wine, University of Adelaide, South Australia, Australia
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143
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Yuan Y, Li P, Ye J. Lipid homeostasis and the formation of macrophage-derived foam cells in atherosclerosis. Protein Cell 2012; 3:173-81. [PMID: 22447659 DOI: 10.1007/s13238-012-2025-6] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2011] [Accepted: 02/04/2012] [Indexed: 01/18/2023] Open
Abstract
Atherosclerosis is a chronic, inflammatory disorder characterized by the deposition of excess lipids in the arterial intima. The formation of macrophage-derived foam cells in a plaque is a hallmark of the development of atherosclerosis. Lipid homeostasis, especially cholesterol homeostasis, plays a crucial role during the formation of foam cells. Recently, lipid droplet-associated proteins, including PAT and CIDE family proteins, have been shown to control the development of atherosclerosis by regulating the formation, growth, stabilization and functions of lipid droplets in macrophage-derived foam cells. This review focuses on the potential mechanisms of formation of macrophage-derived foam cells in atherosclerosis with particular emphasis on the role of lipid homeostasis and lipid droplet-associated proteins. Understanding the process of foam cell formation will aid in the future discovery of novel therapeutic interventions for atherosclerosis.
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Affiliation(s)
- Yuan Yuan
- Department of Pathology, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, China
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144
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Coexisting role of fasting or feeding and dietary lipids in the control of gene expression of enzymes involved in the synthesis of saturated, monounsaturated and polyunsaturated fatty acids. Gene 2012; 496:28-36. [DOI: 10.1016/j.gene.2011.12.022] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2011] [Revised: 12/05/2011] [Accepted: 12/06/2011] [Indexed: 01/17/2023]
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145
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Novel qualitative aspects of tissue fatty acids related to metabolic regulation: lessons from Elovl6 knockout. Prog Lipid Res 2012; 51:267-71. [PMID: 22266797 DOI: 10.1016/j.plipres.2011.12.004] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Insulin resistance, often associated with obesity, precipitates metabolic syndrome, type 2 diabetes, and finally, atherosclerosis. Sources of excess energy cause abnormal accumulation of tissue lipids leading to cellular dysfunction through cellular stress and inflammation. This process is often referred to as lipotoxicity. Until date, effective approaches that aim to overcome insulin resistance involve amelioration of obesity by caloric restriction and/or exercise. Quantitative control of lipids, especially triglycerides and fatty acids in adipose and other tissues, and plasma can be addressed using these measures. However, altering tissue lipid composition may provide another strategy to prevent or control lipotoxicity. Endogenous fatty acid synthesis plays a crucial role in determining tissue energy states. As a target gene of SREBP-1 that controls lipogenesis we identified a unique enzyme, Elovl6, which is responsible for the final step in endogenous saturated fatty acid synthesis, thereby controlling tissue fatty acid composition. Elovl6-deficient mice become obese and develop hepatosteatosis when fed a high-fat diet or when mated to leptin-deficient ob/ob mice. However, the mice exhibited marked protection from hyperinsulinemia, hyperglycemia, and hyperleptinemia. Hepatic fatty acid composition is a novel determinant of insulin sensitivity independent of cellular energy balance. Inhibiting Elovl6 activity may provide a novel therapeutic approach for treating insulin resistance, diabetes, metabolic syndrome, and cardiovascular risks by circumventing obesity problems. In this review, we consider fatty acid metabolism and lipotoxicity, and discuss the role of Elovl6 in newly recognized aspects of metabolic regulation.
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146
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An WS, Lee SM, Son YK, Kim SE, Kim KH, Han JY, Bae HR, Park Y. Effect of omega-3 fatty acids on the modification of erythrocyte membrane fatty acid content including oleic acid in peritoneal dialysis patients. Prostaglandins Leukot Essent Fatty Acids 2012; 86:29-34. [PMID: 22071008 DOI: 10.1016/j.plefa.2011.10.009] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2011] [Revised: 10/21/2011] [Accepted: 10/22/2011] [Indexed: 11/25/2022]
Abstract
Erythrocyte membrane fatty acids (FA), such as oleic acid, are related to acute coronary syndrome. There is no report about the effect of omega-3 FA on oleic acid in peritoneal dialysis (PD) patients. We hypothesized that omega-3 FA can modify erythrocyte membrane FA, including oleic acid, in PD patients. In a double-blind, randomized, placebo-controlled study, 18 patients who were treated with PD for at least 6 months were randomized to treatment for 12 weeks with omega-3 FA or placebo. Erythrocyte membrane FA content was measured by gas chromatography at baseline and after 12 weeks. The erythrocyte membrane content of eicosapentaenoic acid and docosahexaenoic acid was significantly increased and saturated FA and oleic acid were significantly decreased in the omega-3 FA supplementation group after 12 weeks compared to baseline. In conclusion, erythrocyte membrane FA content, including oleic acid, was significantly modified by omega-3 FA supplementation for 12 weeks in PD patients.
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Affiliation(s)
- W S An
- Department of Internal Medicine, Dong-A University College of Medicine, Busan, Republic of Korea.
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Qin L, Sun L, Ye L, Shi J, Zhou L, Yang J, Du B, Song Z, Yu Y, Xie L. A case-control study between the gene polymorphisms of polyunsaturated fatty acids metabolic rate-limiting enzymes and coronary artery disease in a Chinese Han population. Prostaglandins Leukot Essent Fatty Acids 2011; 85:329-33. [PMID: 21917437 DOI: 10.1016/j.plefa.2011.08.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2011] [Revised: 06/20/2011] [Accepted: 08/25/2011] [Indexed: 01/13/2023]
Abstract
To investigate the association between the polymorphisms of fatty acid desaturase 1 (FADS1), fatty acid desaturase 2 (FADS2) and elongation of very long chain fatty acids like 2 (ELOVL2) gene and coronary artery disease (CAD) in a Chinese Han population. Three single nucleotide polymorphisms (SNPs) from these genes were genotyped using PCR-based restriction fragment length polymorphism analysis in 199 CAD cases and 192 controls of Han Chinese origin. rs174556 in the FADS1 gene showed allelic (P=0.002) and genotypic (P=0.030) association with the disease, while there was no disease association for the other two SNPs. The frequency of rs174556 minor allele (T) was significantly higher in the case group than the control group. The trans phase gene-gene interaction analysis showed that the combined genotype of rs174556 (T/T) and rs3756963 (T/T) was weakly associated with the disease (P=0.043). rs174556 in the FADS1 gene is very likely to be associated with CAD in the Chinese Han population.
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Affiliation(s)
- Ling Qin
- Department of Cardiology, First Hospital, Jilin University, Changchun 130031, China
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148
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Saito R, Matsuzaka T, Karasawa T, Sekiya M, Okada N, Igarashi M, Matsumori R, Ishii K, Nakagawa Y, Iwasaki H, Kobayashi K, Yatoh S, Takahashi A, Sone H, Suzuki H, Yahagi N, Yamada N, Shimano H. Macrophage Elovl6 deficiency ameliorates foam cell formation and reduces atherosclerosis in low-density lipoprotein receptor-deficient mice. Arterioscler Thromb Vasc Biol 2011; 31:1973-9. [PMID: 21817094 DOI: 10.1161/atvbaha.110.221663] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
OBJECTIVE Elovl6, a long-chain fatty acid elongase, is a rate-limiting enzyme that elongates saturated and monounsaturated fatty acids and has been shown to be related to obesity-induced insulin resistance via modification of fatty acid composition. In this study, we investigated the roles of Elovl6 in foam cell formation in macrophages and atherosclerosis in mice. METHODS AND RESULTS To investigate the roles of Elovl6 in macrophages in the progression of atherosclerosis, we transplanted bone marrow cells of wild-type or Elovl6(-/-) mice into irradiated LDL-R(-/-) mice that were fed a western diet. Aortic atherosclerotic lesion areas and infiltration of macrophages were significantly smaller in Elovl6(-/-) bone marrow cells-transplanted LDL-R(-/-) mice than in wild-type. Accumulation of esterified cholesterol on exposure to acetylated-LDL was less severe in peritoneal macrophages from Elovl6(-/-) mice than those from wild-type. Cholesterol efflux and expression of cholesterol efflux transporters were increased in Elovl6(-/-) macrophages, although no difference in uptake of acetylated-LDL was found between the two groups. On analysis of fatty acid composition of the esterified cholesterol fraction in macrophages, n-6 polyunsaturated fatty acids were decreased by absence of Elovl6. CONCLUSIONS These findings suggest that Elovl6 in macrophages may contribute to foam cell formation and progression of atherosclerosis.
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Affiliation(s)
- Ryo Saito
- Department of Internal Medicine (Endocrinology and Metabolism), Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan
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Compensatory increase in lipogenic gene expression in adipose tissue of transgenic mice expressing constitutively active AMP-activated protein kinase-alpha1 in liver. Biochem Biophys Res Commun 2011; 412:249-52. [DOI: 10.1016/j.bbrc.2011.07.078] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2011] [Accepted: 07/20/2011] [Indexed: 11/19/2022]
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Morcillo S, Martín-Núñez GM, Rojo-Martínez G, Almaraz MC, García-Escobar E, Mansego ML, de Marco G, Chaves FJ, Soriguer F. ELOVL6 genetic variation is related to insulin sensitivity: a new candidate gene in energy metabolism. PLoS One 2011; 6:e21198. [PMID: 21701577 PMCID: PMC3118791 DOI: 10.1371/journal.pone.0021198] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2010] [Accepted: 05/23/2011] [Indexed: 11/18/2022] Open
Abstract
Background The elongase of long chain fatty acids family 6 (ELOVL6) is an enzyme that specifically catalyzes the elongation of saturated and monounsaturated fatty acids with 12, 14 and 16 carbons. ELOVL6 is expressed in lipogenic tissues and it is regulated by sterol regulatory element binding protein 1 (SREBP-1). Objective We investigated whether ELOVL6 genetic variation is associated with insulin sensitivity in a population from southern Spain. Design We undertook a prospective, population-based study collecting phenotypic, metabolic, nutritional and genetic information. Measurements were made of weight and height and the body mass index (BMI) was calculated. Insulin resistance was measured by homeostasis model assessment. The type of dietary fat was assessed from samples of cooking oil taken from the participants' kitchens and analyzed by gas chromatography. Five SNPs of the ELOVL6 gene were analyzed by SNPlex. Results Carriers of the minor alleles of the SNPs rs9997926 and rs6824447 had a lower risk of having high HOMA_IR, whereas carriers of the minor allele rs17041272 had a higher risk of being insulin resistant. An interaction was detected between the rs6824447 polymorphism and the intake of oil in relation with insulin resistance, such that carriers of this minor allele who consumed sunflower oil had lower HOMA_IR than those who did not have this allele (P = 0.001). Conclusions Genetic variations in the ELOVL6 gene were associated with insulin sensitivity in this population-based study.
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Affiliation(s)
- Sonsoles Morcillo
- Endocrinology and Nutrition Service, Hospital Carlos Haya, Malaga, Spain.
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