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Stearoyl-CoA desaturase-1, a novel target of omega-3 fatty acids for reducing breast cancer risk in obese postmenopausal women. Eur J Clin Nutr 2017; 71:762-765. [PMID: 28145413 DOI: 10.1038/ejcn.2016.273] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Revised: 12/05/2016] [Accepted: 12/10/2016] [Indexed: 11/08/2022]
Abstract
BACKGROUND/OBJECTIVES Conversion of saturated fatty acids to monounsaturated fatty acids by the enzyme stearoyl-Co-A-desaturase (SCD-1) is emerging as a major factor in promoting carcinogenesis including breast cancer. The aim of our study was to explore the regulation of SCD-1 by Raloxifene and omega-3 fatty acids in women at increased risk of breast cancer based on high breast density. SUBJECTS/METHODS As a reflection of SCD-1 activity, we measured the ratios of palmitoleic acid (C16:1n7) to palmitic acid (C16:0) (SCD-16) and oleic acid (C18:1n9) to steric acid (C18:0) (SCD-18) in plasma samples of postmenopausal women enrolled in our clinical trial (NCT00723398) designed to test the effects of the antiestrogen, Raloxifene and/or the omega-3 preparation Lovaza, on breast density, a validated biomarker of breast cancer risk. RESULTS We report that Lovaza but not Raloxifene-reduced SCD-16 and SCD-18 for the 2-year duration of the trial. Importantly, decreasing levels of SCD-16 and SCD-18 were associated with a progressive reduction in breast density but only in obese women (body mass index ⩾30). CONCLUSIONS Body mass index-related factors play an important role in the reduction of breast density and hence breast cancer risk by omega-3 fatty acids. SCD-1 may be a useful biomarker in future clinical trials testing the benefit of nutritional interventions in reducing obesity-associated breast cancer risk.
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Mentzel CMJ, Alkan F, Keinicke H, Jacobsen MJ, Gorodkin J, Fredholm M, Cirera S. Joint Profiling of miRNAs and mRNAs Reveals miRNA Mediated Gene Regulation in the Göttingen Minipig Obesity Model. PLoS One 2016; 11:e0167285. [PMID: 27902747 PMCID: PMC5130236 DOI: 10.1371/journal.pone.0167285] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Accepted: 11/13/2016] [Indexed: 12/23/2022] Open
Abstract
Obesity and its comorbidities are an increasing challenge for both affected individuals and health care systems, worldwide. In obese individuals, perturbation of expression of both protein-coding genes and microRNAs (miRNA) are seen in obesity-relevant tissues (i.e. adipose tissue, liver and skeletal muscle). miRNAs are small non-coding RNA molecules which have important regulatory roles in a wide range of biological processes, including obesity. Rodents are widely used animal models for human diseases including obesity. However, not all research is applicable for human health or diseases. In contrast, pigs are emerging as an excellent animal model for obesity studies, due to their similarities in their metabolism, their digestive tract and their genetics, when compared to humans. The Göttingen minipig is a small sized easy-to-handle pig breed which has been extensively used for modeling human obesity, due to its capacity to develop severe obesity when fed ad libitum. The aim of this study was to identify differentially expressed of protein-coding genes and miRNAs in a Göttingen minipig obesity model. Liver, skeletal muscle and abdominal adipose tissue were sampled from 7 lean and 7 obese minipigs. Differential gene expression was investigated using high-throughput quantitative real-time PCR (qPCR) on 90 mRNAs and 72 miRNAs. The results revealed de-regulation of several obesity and inflammation-relevant protein-coding genes and miRNAs in all tissues examined. Many genes that are known to be de-regulated in obese humans were confirmed in the obese minipigs and several of these genes have target sites for miRNAs expressed in the opposing direction of the gene, confirming miRNA-mediated regulation in obesity. These results confirm the translational value of the pig for human obesity studies.
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Affiliation(s)
- Caroline M. Junker Mentzel
- Animal Genetics, Department of Veterinary Clinical and Animal Science, Faculty of Health Sciences, University of Copenhagen, Frederiksberg, Denmark
- Center for non-coding RNA in Technology and Health, Computational Biology and Bioinformatics, Department of Veterinary Clinical and Animal Science, Faculty of Health Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Ferhat Alkan
- Center for non-coding RNA in Technology and Health, Computational Biology and Bioinformatics, Department of Veterinary Clinical and Animal Science, Faculty of Health Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Helle Keinicke
- Animal Genetics, Department of Veterinary Clinical and Animal Science, Faculty of Health Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Mette J. Jacobsen
- Animal Genetics, Department of Veterinary Clinical and Animal Science, Faculty of Health Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Jan Gorodkin
- Center for non-coding RNA in Technology and Health, Computational Biology and Bioinformatics, Department of Veterinary Clinical and Animal Science, Faculty of Health Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Merete Fredholm
- Animal Genetics, Department of Veterinary Clinical and Animal Science, Faculty of Health Sciences, University of Copenhagen, Frederiksberg, Denmark
- Center for non-coding RNA in Technology and Health, Computational Biology and Bioinformatics, Department of Veterinary Clinical and Animal Science, Faculty of Health Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Susanna Cirera
- Animal Genetics, Department of Veterinary Clinical and Animal Science, Faculty of Health Sciences, University of Copenhagen, Frederiksberg, Denmark
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Liu X, Cui J, Leng K, Xue C, Li Z, Xue Y, Wang Y. Docosahexaenoic acid-enriched phospholipids exhibit superior effects on obesity-related metabolic disorders to egg yolk phospholipids and soybean phospholipids in mice. EUR J LIPID SCI TECH 2016. [DOI: 10.1002/ejlt.201500552] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Xiaofang Liu
- Division of Food Engineering and Nutrition; Yellow Sea Fisheries Research Institute; Chinese Academy of Fishery Sciences; Qingdao Shandong Province P. R. China
| | - Jie Cui
- College of Food Science and Engineering; Ocean University of China; Qingdao Shandong Province P. R. China
| | - Kailiang Leng
- Division of Food Engineering and Nutrition; Yellow Sea Fisheries Research Institute; Chinese Academy of Fishery Sciences; Qingdao Shandong Province P. R. China
| | - Changhu Xue
- College of Food Science and Engineering; Ocean University of China; Qingdao Shandong Province P. R. China
| | - Zhaojie Li
- College of Food Science and Engineering; Ocean University of China; Qingdao Shandong Province P. R. China
| | - Yong Xue
- College of Food Science and Engineering; Ocean University of China; Qingdao Shandong Province P. R. China
| | - Yuming Wang
- College of Food Science and Engineering; Ocean University of China; Qingdao Shandong Province P. R. China
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Zhang J, Ma J, Long K, Jin L, Liu Y, Zhou C, Tian S, Chen L, Luo Z, Tang Q, Jiang A, Wang X, Wang D, Jiang Z, Wang J, Li X, Li M. Dynamic gene expression profiles during postnatal development of porcine subcutaneous adipose. PeerJ 2016; 4:e1768. [PMID: 26989614 PMCID: PMC4793310 DOI: 10.7717/peerj.1768] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Accepted: 02/16/2016] [Indexed: 02/04/2023] Open
Abstract
A better understanding of the control of lipogenesis is of critical importance for both human and animal physiology. This requires a better knowledge of the changes of gene expression during the process of adipose tissue development. Thus, the objective of the current study was to determine the effects of development on subcutaneous adipose tissue gene expression in growing and adult pigs. Here, we present a comprehensive investigation of mRNA transcriptomes in porcine subcutaneous adipose tissue across four developmental stages using digital gene expression profiling. We identified 3,274 differential expressed genes associated with oxidative stress, immune processes, apoptosis, energy metabolism, insulin stimulus, cell cycle, angiogenesis and translation. A set of universally abundant genes (ATP8, COX2, COX3, ND1, ND2, SCD and TUBA1B) was found across all four developmental stages. This set of genes may play important roles in lipogenesis and development. We also identified development-related gene expression patterns that are linked to the different adipose phenotypes. We showed that genes enriched in significantly up-regulated profiles were associated with phosphorylation and angiogenesis. In contrast, genes enriched in significantly down-regulated profiles were related to cell cycle and cytoskeleton organization, suggesting an important role for these biological processes in adipose growth and development. These results provide a resource for studying adipose development and promote the pig as a model organism for researching the development of human obesity, as well as being used in the pig industry.
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Affiliation(s)
- Jie Zhang
- Institute of Animal Genetics and Breeding, College of Animal Science and Technology, Sichuan Agricultural University, Ya'an, Sichuan, China.,Department of Animal Science, Southwest University at Rongchang, Chongqing, China
| | - Jideng Ma
- Institute of Animal Genetics and Breeding, College of Animal Science and Technology, Sichuan Agricultural University, Ya'an, Sichuan, China
| | - Keren Long
- Institute of Animal Genetics and Breeding, College of Animal Science and Technology, Sichuan Agricultural University, Ya'an, Sichuan, China
| | - Long Jin
- Institute of Animal Genetics and Breeding, College of Animal Science and Technology, Sichuan Agricultural University, Ya'an, Sichuan, China
| | - Yihui Liu
- Institute of Animal Genetics and Breeding, College of Animal Science and Technology, Sichuan Agricultural University, Ya'an, Sichuan, China
| | - Chaowei Zhou
- Institute of Animal Genetics and Breeding, College of Animal Science and Technology, Sichuan Agricultural University, Ya'an, Sichuan, China.,Department of Aquaculture, Southwest University at Rongchang, Chongqing, China
| | - Shilin Tian
- Novogene Bioinformatics Institute, Beijing, China
| | - Lei Chen
- Chongqing Academy of Animal Science, Chongqing, China
| | - Zonggang Luo
- Department of Animal Science, Southwest University at Rongchang, Chongqing, China.,Chongqing Academy of Animal Science, Chongqing, China
| | - Qianzi Tang
- Institute of Animal Genetics and Breeding, College of Animal Science and Technology, Sichuan Agricultural University, Ya'an, Sichuan, China
| | - An'an Jiang
- Institute of Animal Genetics and Breeding, College of Animal Science and Technology, Sichuan Agricultural University, Ya'an, Sichuan, China
| | - Xun Wang
- Institute of Animal Genetics and Breeding, College of Animal Science and Technology, Sichuan Agricultural University, Ya'an, Sichuan, China
| | - Dawei Wang
- Novogene Bioinformatics Institute, Beijing, China
| | - Zhi Jiang
- Novogene Bioinformatics Institute, Beijing, China
| | - Jinyong Wang
- Chongqing Academy of Animal Science, Chongqing, China
| | - Xuewei Li
- Institute of Animal Genetics and Breeding, College of Animal Science and Technology, Sichuan Agricultural University, Ya'an, Sichuan, China
| | - Mingzhou Li
- Institute of Animal Genetics and Breeding, College of Animal Science and Technology, Sichuan Agricultural University, Ya'an, Sichuan, China
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Mori A, Kappen KL, Dilger AC, Swanson KS. Effect of photoperiod on the feline adipose transcriptome as assessed by RNA sequencing. BMC Vet Res 2014; 10:146. [PMID: 24992939 PMCID: PMC4092351 DOI: 10.1186/1746-6148-10-146] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Accepted: 06/26/2014] [Indexed: 12/24/2022] Open
Abstract
Background Photoperiod is known to cause physiological changes in seasonal mammals, including changes in body weight, physical activity, reproductive status, and adipose tissue gene expression in several species. The objective of this study was to determine the effects of day length on the adipose transcriptome of cats as assessed by RNA sequencing. Ten healthy adult neutered male domestic shorthair cats were used in a randomized crossover design study. During two 12-wk periods, cats were exposed to either short days (8 hr light:16 hr dark) or long days (16 hr light:8 hr dark). Cats were fed a commercial diet to maintain baseline body weight to avoid weight-related bias. Subcutaneous adipose biopsies were collected at wk 12 of each period for RNA isolation and sequencing. Results A total of 578 million sequences (28.9 million/sample) were generated by Illumina sequencing. A total of 170 mRNA transcripts were differentially expressed between short day- and long day-housed cats. 89 annotated transcripts were up-regulated by short days, while 24 annotated transcripts were down-regulated by short days. Another 57 un-annotated transcripts were also different between groups. Adipose tissue of short day-housed cats had greater expression of genes involved with cell growth and differentiation (e.g., myostatin; frizzled-related protein), cell development and structure (e.g., cytokeratins), and protein processing and ubiquitination (e.g., kelch-like proteins). In contrast, short day-housed cats had decreased expression of genes involved with immune function (e.g., plasminogen activator inhibitor 1; chemokine (C-C motif) ligand 2; C-C motif chemokine 5; T-cell activators), and altered expression of genes associated with carbohydrate and lipid metabolism. Conclusions Collectively, these gene expression changes suggest that short day housing may promote adipogenesis, minimize inflammation and oxidative stress, and alter nutrient metabolism in feline adipose tissue, even when fed to maintain body weight. Although this study has highlighted molecular mechanisms contributing to the seasonal metabolic changes observed in cats, future research that specifically targets and studies these biological pathways, and the physiological outcomes that are affected by them, is justified.
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Affiliation(s)
| | | | | | - Kelly S Swanson
- Department of Animal Sciences, University of Illinois, 1207 West Gregory Drive, 162 Animal Sciences Laboratory, Urbana, IL 61801, USA.
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Fernández Gianotti T, Burgueño A, Gonzales Mansilla N, Pirola CJ, Sookoian S. Fatty liver is associated with transcriptional downregulation of stearoyl-CoA desaturase and impaired protein dimerization. PLoS One 2013; 8:e76912. [PMID: 24098813 PMCID: PMC3786952 DOI: 10.1371/journal.pone.0076912] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Accepted: 08/27/2013] [Indexed: 02/06/2023] Open
Abstract
Aims and Methods We evaluated the modulation of liver stearoyl-CoA desaturase-1 (Scd1) by dietary factors and insulin resistance (IR) in two experimental models of high-fat diet (HFD)-induced nonalcoholic fatty liver disease (NAFLD). The first model included Sprague Dawley (SD) rats that developed NAFLD without IR, and the second one included a rat model of genetic IR and cardiovascular disease, the spontaneously hypertensive rats (SHR) and its normotensive, insulin-sensitive control Wistar-Kyoto (WKY). The adult rats were given standard chow diet (CD) or HFD for 10 weeks. In all the animals, we explored the hepatic Scd1 transcriptional activity and protein levels. Results HFD-fed rats of both strains developed severe NAFLD. Liver abundance of Scd1 mRNA was significantly decreased in HFD-fed rats regardless of the strain; SD-CD: 235±195 vs. SD-HFD 4.5±2.9, p<0.0004, and SHR-CD: 75.6±10.8 vs. SHR-HFD: 4.48±17.4, and WKY-CD: 168.7±17.4 vs. WKY-HFD: 12.9±17.4, p<0.000001 (mean±SE, ANCOVA adjusted by HOMA). Analysis of liver Scd1 protein expression showed a particular pattern in the HFD groups, characterized by the presence of high levels of a monomeric protein band (32.2–36.6 Kda, p<0.003) and decreased levels of a dimeric protein band (61.9–66.1 Kda, p<0.02) regardless of the rat strain. Pharmacologic intervention with the peroxisome proliferator-activated receptor α agonist clofibrate reverted the liver phenotype and significantly modified the hepatic Scd1 transcriptional activity and protein expression. Conclusion Diet-induced fatty liver is associated with the downregulation of hepatic Scd1 transcript and de-dimerization of the protein, and these changes were not much affected by the status of peripheral IR.
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Affiliation(s)
- Tomas Fernández Gianotti
- Department of Molecular Genetics and Biology of Complex Diseases, Institute of Medical Research A Lanari-IDIM, University of Buenos Aires-National Council of Scientific and Technological Research (CONICET), Ciudad Autónoma de Buenos Aires, Argentina
| | - Adriana Burgueño
- Department of Molecular Genetics and Biology of Complex Diseases, Institute of Medical Research A Lanari-IDIM, University of Buenos Aires-National Council of Scientific and Technological Research (CONICET), Ciudad Autónoma de Buenos Aires, Argentina
| | - Noelia Gonzales Mansilla
- Department of Molecular Genetics and Biology of Complex Diseases, Institute of Medical Research A Lanari-IDIM, University of Buenos Aires-National Council of Scientific and Technological Research (CONICET), Ciudad Autónoma de Buenos Aires, Argentina
| | - Carlos Jose Pirola
- Department of Molecular Genetics and Biology of Complex Diseases, Institute of Medical Research A Lanari-IDIM, University of Buenos Aires-National Council of Scientific and Technological Research (CONICET), Ciudad Autónoma de Buenos Aires, Argentina
- * E-mail: (SS); (CJP)
| | - Silvia Sookoian
- Department of Clinical and Molecular Hepatology, Institute of Medical Research A Lanari-IDIM, University of Buenos Aires-National Council of Scientific and Technological Research (CONICET), Ciudad Autónoma de Buenos Aires, Argentina
- * E-mail: (SS); (CJP)
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Hekmatdoost A, Mirmiran P, Hosseini-Esfahani F, Azizi F. Dietary fatty acid composition and metabolic syndrome in Tehranian adults. Nutrition 2012; 27:1002-7. [PMID: 21907897 DOI: 10.1016/j.nut.2010.11.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2010] [Revised: 10/03/2010] [Accepted: 11/03/2010] [Indexed: 12/18/2022]
Abstract
OBJECTIVE Several studies have shown that dietary and plasma fatty acid (FA) composition can modulate the development of metabolic syndrome, but epidemiologic data are scarce. The aim of this study was to evaluate the association between dietary FA composition and metabolic syndrome in Tehranian adults. METHODS Dietary FA composition and symptoms of metabolic syndrome were assessed in a population-based cross-sectional study of 822 participants (354 men and 468 women, 18-74 y old) as part of the Tehran Lipid and Glucose Study. Metabolic syndrome was defined according to the guidelines presented by the Adult Treatment Panel III. RESULTS The means ± standard deviations for dietary FA composition of total fat, linoleic acid, oleic acid, and saturated FA were 30.3 ± 7.5%, 1.43 ± 1.76%, 2.87 ± 2.19%, and 5.7 ± 2.2% of daily consumed energy, respectively. No significant correlation between the percentage of linoleic or oleic acids and metabolic syndrome was observed. Participants whose consumption of saturated FA was in the highest quartile had a significantly increased probability of acquiring metabolic syndrome (odds ratios by quartile 1, 0.83, 0.91, 0.95, P for trend <0.03). The odds ratios decreased after adjusting for indicators of a healthy lifestyle, including diet. CONCLUSION The data from this study indicate that increased consumption of dietary total fat, especially saturated FA, is associated with a higher risk of metabolic syndrome in Tehranian adults. The relation, apparently, is influenced by an individual's lifestyle.
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Affiliation(s)
- Azita Hekmatdoost
- Department of Clinical Nutrition and Dietetics, Faculty of Nutrition Sciences and Food Technology, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
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Kim HW, Rao JS, Rapoport SI, Igarashi M. Dietary n-6 PUFA deprivation downregulates arachidonate but upregulates docosahexaenoate metabolizing enzymes in rat brain. Biochim Biophys Acta Mol Cell Biol Lipids 2010; 1811:111-7. [PMID: 21070866 DOI: 10.1016/j.bbalip.2010.10.005] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2010] [Revised: 10/26/2010] [Accepted: 10/27/2010] [Indexed: 11/28/2022]
Abstract
BACKGROUND Dietary n-3 polyunsaturated fatty acid (PUFA) deprivation increases expression of arachidonic acid (AA 20:4n-6)-selective cytosolic phospholipase A(2) (cPLA(2)) IVA and cyclooxygenase (COX)-2 in rat brain, while decreasing expression of docosahexaenoic acid (DHA 22:6n-3)-selective calcium-independent iPLA(2) VIA. Assuming that these enzyme changes represent brain homeostatic responses to deprivation, we hypothesized that dietary n-6 PUFA deprivation would produce changes in the opposite directions. METHODS Brain expression of PUFA-metabolizing enzymes and their transcription factors was quantified in male rats fed an n-6 PUFA adequate or deficient diet for 15weeks post-weaning. RESULTS The deficient compared with adequate diet increased brain mRNA, protein and activity of iPLA(2) VIA and 15-lipoxygenase (LOX), but decreased cPLA(2) IVA and COX-2 expression. The brain protein level of the iPLA(2) transcription factor SREBP-1 was elevated, while protein levels were decreased for AP-2α and NF-κB p65, cPLA(2) and COX-2 transcription factors, respectively. CONCLUSIONS With dietary n-6 PUFA deprivation, rat brain PUFA metabolizing enzymes and some of their transcription factors change in a way that would homeostatically dampen reductions in brain n-6 PUFA concentrations and metabolism, while n-3 PUFA metabolizing enzyme expression is increased. The changes correspond to reported in vitro enzyme selectivities for AA compared with DHA.
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Affiliation(s)
- Hyung-Wook Kim
- National Institute on Aging, National Institutes of Health, Bethesda, MD, USA.
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Deiuliis J, Shin J, Murphy E, Kronberg SL, Eastridge ML, Suh Y, Yoon JT, Lee K. Bovine adipose triglyceride lipase is not altered and adipocyte fatty acid-binding protein is increased by dietary flaxseed. Lipids 2010; 45:963-73. [PMID: 20886305 DOI: 10.1007/s11745-010-3476-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2010] [Accepted: 09/14/2010] [Indexed: 12/25/2022]
Abstract
In this paper, we report the full-length coding sequence of bovine ATGL cDNA and analyze its expression in bovine tissues. Similar to human, mouse, and pig ATGL sequences, bovine ATGL has a highly conserved patatin domain that is necessary for lipolytic function in mice and humans. This suggests that ATGL is functionally intact as a triglyceride lipase in cattle. Tissue distribution of ATGL gene expression was highest in fat and muscle (skeletal and cardiac) tissue, while protein expression was solely detectible in the adipose tissue. The effect of 109 days of flaxseed supplementation on ATGL and adipocyte fatty acid-binding protein (FABP4 or A-FABP, E-FABP or FABP5) expression was examined in Angus steers. Supplemented steers had greater triacylglycerol (TAG) content in the muscle compared with unsupplemented ones. Additionally, supplementation increased A-FABP expression and decreased stearoyl-CoA desaturase 1 (SCD-1) expression in muscle, while total ATGL expression was unaffected. In summary, supplementation of cattle rations with flaxseed increased muscle TAG concentrations attributed in part to increased expression of key enzymes involved in lipid trafficking (A-FABP) and metabolism (SCD-1).
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Affiliation(s)
- Jeffrey Deiuliis
- Department of Animal Sciences and The Ohio State University Interdisciplinary Human Nutrition Program, The Ohio State University, Columbus, OH, USA
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Manickam E, Sinclair AJ, Cameron-Smith D. Suppressive actions of eicosapentaenoic acid on lipid droplet formation in 3T3-L1 adipocytes. Lipids Health Dis 2010; 9:57. [PMID: 20525346 PMCID: PMC2895668 DOI: 10.1186/1476-511x-9-57] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2010] [Accepted: 06/04/2010] [Indexed: 11/25/2022] Open
Abstract
Background Lipid droplet (LD) formation and size regulation reflects both lipid influx and efflux, and is central in the regulation of adipocyte metabolism, including adipokine secretion. The length and degree of dietary fatty acid (FA) unsaturation is implicated in LD formation and regulation in adipocytes. The aims of this study were to establish the impact of eicosapentaenoic acid (EPA; C20:5n-3) in comparison to SFA (STA; stearic acid, C18:0) and MUFA (OLA; oleic acid, C18:1n-9) on 3T3-L1 adipocyte LD formation, regulation of genes central to LD function and adipokine responsiveness. Cells were supplemented with 100 μM FA during 7-day differentiation. Results EPA markedly reduced LD size and total lipid accumulation, suppressing PPARγ, Cidea and D9D/SCD1 genes, distinct from other treatments. These changes were independent of alterations of lipolytic genes, as both EPA and STA similarly elevated LPL and HSL gene expressions. In response to acute lipopolysaccharide exposure, EPA-differentiated adipocytes had distinct improvement in inflammatory response shown by reduction in monocyte chemoattractant protein-1 and interleukin-6 and elevation in adiponectin and leptin gene expressions. Conclusions This study demonstrates that EPA differentially modulates adipogenesis and lipid accumulation to suppress LD formation and size. This may be due to suppressed gene expression of key proteins closely associated with LD function. Further analysis is required to determine if EPA exerts a similar influence on LD formation and regulation in-vivo.
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Affiliation(s)
- Elizabeth Manickam
- Molecular Nutrition Unit, School of Exercise and Nutrition Sciences, Faculty of Health, Medicine, Nursing and Behavioural Sciences, Deakin University, Melbourne, Victoria, Australia
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Kuhnt K, Flotho S, Benjamin S, Boerchers T, Schubert R, Jahreis G, Spener F. Gene expression after dietary intervention with trans fatty acids (trans-11/trans-12 18:1) in humans. EUR J LIPID SCI TECH 2009. [DOI: 10.1002/ejlt.200800217] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Bujalska IJ, Hewitt KN, Hauton D, Lavery GG, Tomlinson JW, Walker EA, Stewart PM. Lack of hexose-6-phosphate dehydrogenase impairs lipid mobilization from mouse adipose tissue. Endocrinology 2008; 149:2584-91. [PMID: 18218694 PMCID: PMC2329282 DOI: 10.1210/en.2007-1705] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
In adipose tissue, glucocorticoids regulate lipogenesis and lipolysis. Hexose-6-phosphate dehydrogenase (H6PDH) is an enzyme located in the endoplasmic reticulum that provides a cofactor for the enzyme 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1), regulating the set point of its activity and allowing for tissue-specific activation of glucocorticoids. The aim of this study was to examine the adipose tissue biology of the H6PDH null (H6PDH/KO) mouse. Real-time PCR analysis confirmed similar mRNA levels of 11beta-HSD1 and glucocorticoid receptor-alpha in wild-type (WT) and H6PDH/KO mice in liver and gonadal fat depots. Microsomal 11beta-HSD1 protein levels shown by Western blot analysis corresponded well with mRNA expression in gonadal fat of WT and H6PDH/KO mice. Despite this, the enzyme directionality in these tissues changed from predominately oxoreductase in WT to exclusively dehydrogenase activity in the H6PDH/KO mice. In the fed state, H6PDH/KO mice had reduced adipose tissue mass, but histological examination revealed no difference in average adipocyte size between genotypes. mRNA expression levels of the key lipogenic enzymes, acetyl CoA carboxylase, adiponutrin, and stearoyl-coenzyme A desaturase-2, were decreased in H6PDH/KO mice, indicative of impaired lipogenesis. In addition, lipolysis rates were also impaired in the H6PDH/KO as determined by lack of mobilization of fat and no change in serum free fatty acid concentrations upon fasting. In conclusion, in the absence of H6PDH, the set point of 11beta-HSD1 enzyme activity is switched from predominantly oxoreductase to dehydrogenase activity in adipose tissue; as a consequence, this leads to impairment of fat storage and mobilization.
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Affiliation(s)
- Iwona J Bujalska
- Division of medical Sciences (Medicine), University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
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Stefan N, Peter A, Cegan A, Staiger H, Machann J, Schick F, Claussen CD, Fritsche A, Häring HU, Schleicher E. Low hepatic stearoyl-CoA desaturase 1 activity is associated with fatty liver and insulin resistance in obese humans. Diabetologia 2008; 51:648-56. [PMID: 18286258 DOI: 10.1007/s00125-008-0938-7] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2007] [Accepted: 01/02/2008] [Indexed: 02/07/2023]
Abstract
AIMS/HYPOTHESIS Stearoyl-CoA desaturase 1 (SCD1) is the rate-limiting enzyme in monounsaturated fatty acid synthesis. It is imperative for the assembly of VLDL particles, which transport triacylglycerol (TG) from liver to adipose tissue and other sites. We aimed to determine the role of hepatic SCD1 activity in human glucose and lipid metabolism. METHODS We studied 54 people participating in a lifestyle intervention programme with diet modification and increased physical activity. Insulin sensitivity was determined during a euglycaemic-hyperinsulinaemic clamp and estimated from an OGTT. Liver fat was quantified by (1)H-magnetic resonance spectroscopy at baseline and after 9 months of intervention. The pattern of fatty acids in serum VLDL-TGs was determined by ultracentrifugation followed by thin layer and gas chromatography, with the 18:1 n-9: 18:0 ratio providing an index of hepatic SCD1 activity. RESULTS The hepatic SCD1 activity index correlated negatively with liver fat (r= -0.29, p=0.04) and positively with insulin sensitivity, both OGTT-derived (r=0.42, p=0.003) and clamp-derived (r=0.27, p=0.07). These correlations depended on overall adiposity. They were absent in leaner participants (n=27, liver fat: p=0.34, insulin sensitivity [OGTT]: p=0.75, insulin sensitivity [clamp]: p=0.24), but were strong in obese individuals (n=27, p=0.004, p=0.0002 and p=0.006, respectively). Furthermore, during intervention a high SCD1 activity index at baseline predicted a decrease in liver fat only in obese participants (r= -0.46, p=0.02). CONCLUSIONS/INTERPRETATION Our data suggest that high hepatic SCD1 activity may regulate fat accumulation in the liver and possibly protects from insulin resistance in obesity.
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Affiliation(s)
- N Stefan
- Department of Internal Medicine, Division of Endocrinology, Diabetology, Vascular Medicine, Nephrology and Clinical Chemistry, University of Tübingen, Otfried-Müller-Str. 10, 72076 Tübingen, Germany.
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Dobrzyn P, Ntambi JM, Dobrzyn A. Stearoyl-CoA desaturase: A novel control point of lipid metabolism and insulin sensitivity. EUR J LIPID SCI TECH 2008. [DOI: 10.1002/ejlt.200700249] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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15
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Lengi AJ, Corl BA. Identification and characterization of a novel bovine stearoyl-CoA desaturase isoform with homology to human SCD5. Lipids 2007; 42:499-508. [PMID: 17468887 DOI: 10.1007/s11745-007-3056-2] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2007] [Accepted: 03/16/2007] [Indexed: 11/30/2022]
Abstract
Stearoyl-CoA desaturase (SCD) is an enzyme responsible for the production of cis-9, trans-11 conjugated linoleic acid in ruminant fats, and for the synthesis of palmitoleoyl-CoA and oleoyl-CoA. To date, only one SCD isoform has been described in ruminant species, although multiple isoforms have been found in many other mammalian species. In this paper, we describe for the first time a second SCD isoform in cattle, which appears to be an ortholog of human SCD5 rather than a homolog of bovine SCD1 or any of the described murine SCD isoforms. As described in other SCD proteins, the predicted amino acid sequence of bovine SCD5 includes four transmembrane domains and three conserved histidine motifs. The amino-terminus of the predicted protein sequence of SCD5 lacks the PEST sequences typically found in SCD1 homologs, which are thought to target proteins for rapid degradation. Similar to human SCD5, the bovine SCD5 gene is organized into five exons and four introns, and is highly expressed in the brain. In other tissues examined, mRNA expression of SCD5 was minimal. Furthermore, the expression levels of SCD5 between brain gray and white matter are not different. This is the first description of a homolog of human SCD5 in a non-primate species.
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Affiliation(s)
- Andrea J Lengi
- Department of Dairy Science, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
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16
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Jeffcoat R. Obesity - a perspective based on the biochemical interrelationship of lipids and carbohydrates. Med Hypotheses 2007; 68:1159-71. [PMID: 17257774 DOI: 10.1016/j.mehy.2006.06.009] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2006] [Accepted: 06/02/2006] [Indexed: 01/12/2023]
Abstract
Many factors affect the onset of obesity including satiety control, reduced levels of physical exercise as well as hormonal and genetic parameters which influence the metabolic pathways leading to the net accumulation of triacylglycerol (TAG). The predominant fatty acid of human adipose tissue TAGs is oleic acid, reflecting primarily the composition of the diet but also the product of de novo lipogenesis. Consequently, both carbohydrates and lipids are potential sources of these stored fats. Many studies have been carried out using a variety of differing experimental protocols on healthy, obese or diabetic humans and animals in positive or neutral energy balance to establish the underlying molecular basis for obesity particularly in humans. This short review discusses the interdependence and control of the metabolism of lipids and carbohydrates as it relates to lipogenesis and proposes a unified hypothesis for obesity which brings together a number of different approaches focusing on (i) the interaction of dietary fat and carbohydrate, which typically represent approximately 80% of the daily caloric intake, and their role in the synthesis of TAGs, (ii) the biochemical pathways which control the amount of TAG produced by controlling the composition of their fatty acids via the action of stearoyl-CoA desaturase (SCD), (iii) the control of lipogenesis and SCD by dietary polyunsaturated fatty acid (PUFA) and (iv) the interaction of PUFAs with the transcription factors, peroxisome proliferator activated receptors (PPAR) alpha and gamma, which maintain the balance between oxidation and storage of lipids. The hypothesis focuses on the central role of stearoyl-CoA desaturase (SCD) and its inhibition by polyunsaturated fatty acids (PUFAs) acting via transcription factors based upon data obtained from both animal and human studies. From these observations it should be possible to determine the relevance of the hypothesis to humans and to speculate how these aspects of metabolism may impact the risk of developing related diseases such as coronary heart disease, Type 2 diabetes and certain forms of cancer.
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Affiliation(s)
- Roger Jeffcoat
- Hawthorn House, Higham Road, Chelveston, Wellingborough, Northants NN9 6AH, UK.
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17
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Rahman SM, Dobrzyn A, Lee SH, Dobrzyn P, Miyazaki M, Ntambi JM. Stearoyl-CoA desaturase 1 deficiency increases insulin signaling and glycogen accumulation in brown adipose tissue. Am J Physiol Endocrinol Metab 2005; 288:E381-7. [PMID: 15494611 DOI: 10.1152/ajpendo.00314.2004] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Stearoyl-CoA desaturase (SCD) catalyzes the synthesis of oleate (C18:1) and palmitoleate (C16:1), which are the main monounsaturated fatty acids of membrane phospholipids, triglycerides, wax esters, and cholesterol esters. Previously, we showed that SCD1 deficiency elevates insulin-signaling components and downregulates protein-tyrosine phosphatase-1B (PTP-1B) in muscle, a major insulin-sensitive tissue. Here we found that, in brown adipose tissue (BAT), another insulin-sensitive tissue, the basal tyrosine phosphorylations of insulin receptor (IR) and IR substrates (IRS-1 and IRS-2) were upregulated in SCD1(-/-) mice compared with wild-type mice. The association of IRS-1 and IRS-2 with the alpha-p85 subunit of phosphatidylinositol 3-kinase as well as Akt-Ser(473) and Akt-Thr(308) phosphorylation is also elevated in the SCD1(-/-) mice. The mRNA expression, protein levels, and activity of PTP-1B implicated in the attenuation of the insulin signal are reduced in the SCD1(-/-) mice. The content of GLUT4 in the plasma membrane increased 2.5-fold, and this was accompanied by a 6-fold increase in glucose uptake in BAT of SCD1(-/-) mice. The increased glucose uptake was associated with higher glycogen synthase activity and glycogen accumulation. In the presence of insulin, [U-(14)C]glucose incorporation into glycogen was increased in BAT of SCD1(-/-) mice. Taken together, these studies illustrate increased insulin signaling and increased glycogen metabolism in BAT of SCD1(-/-) mice.
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Affiliation(s)
- Shaikh Mizanoor Rahman
- Dept. of Biochemistry, University of Wisconsin, 433 Babcock Drive, Madison, WI 53706, USA
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18
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Arao K, Wang YM, Inoue N, Hirata J, Cha JY, Nagao K, Yanagita T. Dietary effect of pomegranate seed oil rich in 9cis, 11trans, 13cis conjugated linolenic acid on lipid metabolism in obese, hyperlipidemic OLETF rats. Lipids Health Dis 2004; 3:24. [PMID: 15533261 PMCID: PMC534798 DOI: 10.1186/1476-511x-3-24] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2004] [Accepted: 11/09/2004] [Indexed: 11/10/2022] Open
Abstract
Conjugated fatty acid, the general term of positional and geometric isomers of polyunsaturated fatty acids with conjugated double bonds, has attracted considerable attention because of its potentially beneficial biological effects. In the present study, dietary effect of pomegranate seed oil rich in punicic acid (9cis, 11trans, 13cis-conjugated linolenic acid; 9c, 11t, 13c-CLNA) on lipid metabolism was investigated in obese, hyperlipidemic Otsuka Long-Evans Tokushima Fatty (OLETF) rats. After 2 weeks feeding period, OLETF rats revealed obesity and hyperlipidemia compared with their progenitor LETO rats. Feeding of the diet supplemented with 9% safflower oil and 1% pomegranate seed oil (9c, 11t, 13c-CLNA diet) did not affect abdominal white adipose tissue weights and serum lipid levels compared with the diet supplemented with 10% safflower oil (control diet) in OLETF rats. However, the accumulated hepatic triacylglycerol was markedly decreased by 9c, 11t, 13c-CLNA diet in OLETF rats. Activities of hepatic enzymes related to fatty acid synthesis and fatty acid beta-oxidation were not altered by 9c, 11t, 13c-CLNA diet. Levels of monounsaturated fatty acid (MUFA), major storage form of fatty acid, in serum triacylglycerol were markedly higher in obese, hyperlipidemic OLETF rats than in lean LETO rats. In addition, 9c, 11t, 13c-CLNA diet significantly decreased MUFA levels in OLETF rats. This is the first study showing that 9c, 11t, 13c-CLNA suppresses delta-9 desaturation in vivo, and we suggest that the alleviation of hepatic triacylglycerol accumulation by 9c, 11t, 13c-CLNA diet was, at least in part, attributable to the suppression of delta-9 desaturation in OLETF rats.
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Affiliation(s)
- Keisuke Arao
- Department of Applied Biological Sciences, Saga University, Saga 840-8502, Japan
| | - Yu-Ming Wang
- Department of Applied Biological Sciences, Saga University, Saga 840-8502, Japan
| | - Nao Inoue
- Department of Applied Biological Sciences, Saga University, Saga 840-8502, Japan
| | - Junichi Hirata
- Department of Applied Biological Sciences, Saga University, Saga 840-8502, Japan
| | - Jae-Young Cha
- Department of Applied Biological Sciences, Saga University, Saga 840-8502, Japan
| | - Koji Nagao
- Department of Applied Biological Sciences, Saga University, Saga 840-8502, Japan
| | - Teruyoshi Yanagita
- Department of Applied Biological Sciences, Saga University, Saga 840-8502, Japan
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Rahman SM, Dobrzyn A, Dobrzyn P, Lee SH, Miyazaki M, Ntambi JM. Stearoyl-CoA desaturase 1 deficiency elevates insulin-signaling components and down-regulates protein-tyrosine phosphatase 1B in muscle. Proc Natl Acad Sci U S A 2003; 100:11110-5. [PMID: 12960377 PMCID: PMC196935 DOI: 10.1073/pnas.1934571100] [Citation(s) in RCA: 146] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2003] [Indexed: 11/18/2022] Open
Abstract
We have shown previously that mice with a targeted disruption in the stearoyl-CoA desaturase 1 gene (SCD1-/-) have increased insulin sensitivity compared with control mice. Here we show that the SCD1-/- mice have increased insulin signaling in muscle. The basal tyrosine phosphorylation of the insulin receptor and insulin receptor substrates 1 and 2 are elevated. The tyrosine phosphorylation of insulin-like growth factor-1 receptor was similar between SCD1+/+ and SCD1-/- mice. The association of insulin receptor substrates 1 and 2 with alphap85 subunit of phosphatidylinositol 3-kinase as well as the phosphorylation of Akt-Ser-473 and Akt-Thr-308 are also elevated in the SCD1-/- mice. Interestingly, the mRNA levels, protein mass, and activity of the protein-tyrosine phosphatase-1B implicated in the attenuation of the insulin signal are reduced in the SCD1-/- mice, whereas the levels of the leukocyte antigen-related protein phosphatase are similar between two groups of mice. The content of glucose transporter 4 in the plasma membrane and basal as well as insulin-mediated glucose uptake are increased in the SCD1-/- mice. In addition, the muscle glycogen content and the activities of glycogen synthase and phosphorylase are increased in the SCD1-/- mice. We hypothesize that loss of SCD1 function induces increased insulin signaling at least in part by a reduction in the expression of protein-tyrosine phosphatase 1B. SCD1 could be a therapeutic target in the treatment of diabetes.
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20
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Montanaro MA, Rimoldi OJ, Igal RA, Montenegro S, Tarrés MC, Martínez SM, Brenner RR. Hepatic Δ9, Δ6, and Δ5 desaturations in non-insulin-dependent diabetes mellitus eSS rats. Lipids 2003; 38:827-32. [PMID: 14577661 DOI: 10.1007/s11745-003-1132-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Both diabetes mellitus type 1 and diabetes mellitus type 2 are widespread diseases that alter carbohydrate and lipid metabolism. e Stilmann-Salgado (eSS) rats are experimental animals that spontaneously evolve to a state similar to that of young people affected by non-insulin-dependent diabetes mellitus (NIDDM; type 2). Using 6-mon-old eSS rats that, according to the literature [Martinez, S.M., Tarrés, M.C., Montenegro, S., Milo, R., Picena, J.C., Figueroa, N., and Rabasa, S.R. (1988) Spontaneous Diabetes in eSS Rats, Acta Diabetol. Lat. 25, 303-313], had already developed insulin resistance, we investigated the changes evoked on delta9, delta6, and delta5 liver desaturases. The abundance of mRNA and enzymatic activities were measured, as well as the FA composition of liver microsomal lipids. Compared to control rats, the mRNA content and activity of SCD-1 (stearoyl CoA-desaturase, isoform of the delta9 desaturase) were significantly higher, whereas the mRNA and activities of delta6 and delta5 desaturases were not significantly modified. Correspondingly, the proportion of 18:1n-9 and the ratios of 18:1n-9/18:0 and 16:1/16:0 in lipids were significantly increased, whereas the proportion of 20:4n-6 was unaltered. These effects were found while glycemia was constant or increased. The results are completely opposite those described in insulin-dependent diabetes mellitus (type 1), in which a depression of all the desaturases is found. They suggest that in eSS rats, the activities of the desaturases were not modified by an insulin-resistance effect. Moreover, we suggest that the enhancement of SCD-1 activity might be considered as another typical sign of the NIDDM syndrome, because it has also been found in other animal models of NIDDM, for example, the ones evoked by the sucrose-rich diet and in the Zucker rat.
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MESH Headings
- Animals
- Delta-5 Fatty Acid Desaturase
- Diabetes Mellitus, Experimental/blood
- Diabetes Mellitus, Experimental/enzymology
- Diabetes Mellitus, Experimental/genetics
- Diabetes Mellitus, Type 2/blood
- Diabetes Mellitus, Type 2/enzymology
- Diabetes Mellitus, Type 2/genetics
- Fatty Acid Desaturases/genetics
- Fatty Acid Desaturases/metabolism
- Fatty Acids/analysis
- Linoleoyl-CoA Desaturase
- Liver/cytology
- Liver/enzymology
- Liver/metabolism
- Male
- Microsomes, Liver/chemistry
- Microsomes, Liver/enzymology
- RNA, Messenger/analysis
- RNA, Messenger/genetics
- Rats
- Stearoyl-CoA Desaturase/genetics
- Stearoyl-CoA Desaturase/metabolism
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Affiliation(s)
- Mauro A Montanaro
- Instituto de Investigaciones Bioquímicas de La Plata, Universidad Nacional de La Plata-Consejo Nacional de Investigaciones Cientificas y Técnicas, Facultad de Ciencias Médicas, UNLP, La Plata, Argentina
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21
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Ntambi JM, Miyazaki M, Stoehr JP, Lan H, Kendziorski CM, Yandell BS, Song Y, Cohen P, Friedman JM, Attie AD. Loss of stearoyl-CoA desaturase-1 function protects mice against adiposity. Proc Natl Acad Sci U S A 2002; 99:11482-6. [PMID: 12177411 PMCID: PMC123282 DOI: 10.1073/pnas.132384699] [Citation(s) in RCA: 847] [Impact Index Per Article: 38.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Stearoyl-CoA desaturase (SCD) is a central lipogenic enzyme catalyzing the synthesis of monounsaturated fatty acids, mainly oleate (C18:1) and palmitoleate (C16:1), which are components of membrane phospholipids, triglycerides, wax esters, and cholesterol esters. Several SCD isoforms (SCD1-3) exist in the mouse. Here we show that mice with a targeted disruption of the SCD1 isoform have reduced body adiposity, increased insulin sensitivity, and are resistant to diet-induced weight gain. The protection from obesity involves increased energy expenditure and increased oxygen consumption. Compared with the wild-type mice the SCD1-/- mice have increased levels of plasma ketone bodies but reduced levels of plasma insulin and leptin. In the SCD1-/- mice, the expression of several genes of lipid oxidation are up-regulated, whereas lipid synthesis genes are down-regulated. These observations suggest that a consequence of SCD1 deficiency is an activation of lipid oxidation in addition to reduced triglyceride synthesis and storage.
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Affiliation(s)
- James M Ntambi
- Department of Biochemistry, University of Wisconsin, Madison, WI 53706, USA.
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22
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Bassilian S, Ahmed S, Lim SK, Boros LG, Mao CS, Lee WNP. Loss of regulation of lipogenesis in the Zucker diabetic rat. II. Changes in stearate and oleate synthesis. Am J Physiol Endocrinol Metab 2002; 282:E507-13. [PMID: 11832351 DOI: 10.1152/ajpendo.00211.2001] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
De novo lipogenesis and dietary fat uptake are two major sources of fatty acid deposits in fat of obese animals. To determine the relative contribution of fatty acids from these two sources in obesity, we have determined the distribution of c16 and c18 fatty acids of triglycerides in plasma, liver, and epididymal fat pad of Zucker diabetic fatty (ZDF) rats and their lean littermates (ZL) under two isocaloric dietary fat conditions. Lipogenesis was also determined using the deuterated water method. Conversion of palmitate to stearate and stearate to oleate was calculated from the deuterium incorporation by use of the tracer dilution principle. In the ZL rat, lipogenesis was suppressed from 70 to 24%, conversion of palmitate to stearate from 86 to 78%, and conversion of stearate to oleate from 56 to 7% in response to an increase in the dietary fat-to-carbohydrate ratio. The results suggest that suppression of fatty acid synthase and stearoyl-CoA desaturase activities is a normal adaptive mechanism to a high-fat diet. In contrast, de novo lipogenesis, chain elongation, and desaturation were not suppressed by dietary fat in the ZDF rat. The lack of ability to adapt to a high-fat diet resulted in a higher plasma triglyceride concentration and excessive fat accumulation from both diet and de novo synthesis in the ZDF rat.
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Affiliation(s)
- Sara Bassilian
- Department of Pediatrics, Research and Education Institute, Harbor-UCLA Medical Center, Torrance, California 90502, USA
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23
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Zhang L, Ge L, Tran T, Stenn K, Prouty SM. Isolation and characterization of the human stearoyl-CoA desaturase gene promoter: requirement of a conserved CCAAT cis-element. Biochem J 2001; 357:183-93. [PMID: 11415448 PMCID: PMC1221940 DOI: 10.1042/0264-6021:3570183] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Stearoyl-CoA desaturase is the rate-limiting enzyme in the production of mono-unsaturated fatty acids. We have recently cloned and characterized the human Scd cDNA and SCD (the stearoyl-CoA desaturase structural gene) on chromosome 10, as well as the non-transcribed pseudogene on chromosome 17. In order to further define SCD regulation and function, we have isolated and characterized the promoter of the structural gene. Screening of chromosome-10-specific libraries resulted in the isolation of 4.1 kb of SCD sequence upstream of the translation start site. Binding sites for transcription factors critical for mouse Scd1 and Scd2 promoter activity, such as sterol-regulated-element-binding protein and nuclear factor Y, were present in the human SCD promoter (Scd is the mouse stearoyl-CoA desaturase gene). Deletion analysis in HaCaT keratinocytes identified a critical region for promoter activity between nts 496-609 upstream of the translation start site. Site-directed mutagenesis of binding sites in this region identified the CCAAT box as the critical cis-element for SCD promoter activity. An electrophoretic mobility-shift assay confirmed that this element binds nuclear proteins from HaCaT keratinocytes. The polyunsaturated-fatty-acid (PUFA) response element, previously identified in the promoters of mouse Scd1 and Scd2, was found to be conserved in the human SCD promoter, and contained the critical CCAAT cis-element. A minimal promoter construct including this region was responsive to fatty acids, with oleate and linoleate decreasing transcription and stearate increasing it. These studies indicate that CCAAT-box-binding proteins activate SCD transcription in cultured keratinocytes and that fatty acids modulate transcription, most likely through the conserved PUFA response element.
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Affiliation(s)
- L Zhang
- Skin Biology Technical Resourse Center, Johnson and Johnson, Consumer Products World Wide, 199 Grandview Road, Skillman, NJ 08558, USA
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25
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Jones BH, Standridge MK, Claycombe KJ, Smith PJ, Moustaïd-Moussa N. Glucose induces expression of stearoyl-CoA desaturase in 3T3-L1 adipocytes. Biochem J 1998; 335 ( Pt 2):405-8. [PMID: 9867800 PMCID: PMC1219803 DOI: 10.1042/bj3350405] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Stearoyl-CoA desaturase (SCD; EC 1.14.99.5) is a key enzyme in the synthesis polyunsaturated fatty acids. Liver and ose tissue are the predominant sites of SCD expression. Regulation of tic SCD by various nutritional and hormonal ors, such as insulin, dietary carbohydrates and polyunsaturated fatty s, has been well documented. Little is known, ver, about adipocyte SCD regulation despite high levels of SCD activity adipose tissue. The present study was gned to investigate SCD regulation in adipocytes by examining the cts of glucose and insulin on SCD expression. We rt here that glucose availability directly increased SCD gene scription in 3T3-L1 adipocytes. This response was pendent of insulin, and insulin alone in the absence of glucose had no ct on SCD mRNA levels. SCD thus represents a l model in which to investigate the mechanisms of direct regulation of expression by glucose in adipose cells.
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Affiliation(s)
- B H Jones
- Department of Nutrition, University of Tennesse, Knoxville, TN 37996-1900, USA
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26
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Tocher DR, Leaver MJ, Hodgson PA. Recent advances in the biochemistry and molecular biology of fatty acyl desaturases. Prog Lipid Res 1998; 37:73-117. [PMID: 9829122 DOI: 10.1016/s0163-7827(98)00005-8] [Citation(s) in RCA: 227] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Affiliation(s)
- D R Tocher
- NERC Unit of Aquatic Biochemistry, School of Natural Sciences, University of Stirling, Scotland, U.K
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