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Rolph MS, Young TR, Shum BOV, Gorgun CZ, Schmitz-Peiffer C, Ramshaw IA, Hotamisligil GS, Mackay CR. Regulation of dendritic cell function and T cell priming by the fatty acid-binding protein AP2. THE JOURNAL OF IMMUNOLOGY 2007; 177:7794-801. [PMID: 17114450 DOI: 10.4049/jimmunol.177.11.7794] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The fatty acid-binding protein (FABP) family consists of a number of conserved cytoplasmic proteins with roles in intracellular lipid transport, storage, and metabolism. Examination of a comprehensive leukocyte gene expression database revealed strong expression of the adipocyte FABP aP2 in human monocyte-derived dendritic cells (DCs). We isolated bone marrow-derived DC from aP2-deficient mice, and showed that expression of DC cytokines including IL-12 and TNF was significantly impaired in these cells. Degradation of IkappaBalpha was also impaired in aP2-deficient DCs, indicative of reduced signaling through the IkappaB kinase-NF-kappaB pathway. The cytokine defect was selective because there was no effect on Ag uptake or expression of MHC class II, CD40, CD80, or CD86. In an MLR, aP2-deficient DCs stimulated markedly lower T cell proliferation and cytokine production than did wild-type DCs. Moreover, aP2-deficient mice immunized with keyhole limpet hemocyanin/CFA showed reduced production of IFN-gamma by restimulated draining lymph node cells, suggesting a similar defect in DC function in vivo. Similarly, infection of aP2-deficient mice with the natural mouse pathogen ectromelia virus resulted in substantially lower production of IFN-gamma by CD8+ T cells. Thus, FABP aP2 plays an important role in DC function and T cell priming, and provides an additional link between metabolic processes and the regulation of immune responses.
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Affiliation(s)
- Michael S Rolph
- Immunology and Inflammation Research Program, Garvan Institute for Medical Research, Darlinghurst, New South Wales 2010, Australia.
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252
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Klapper M, Böhme M, Nitz I, Döring F. Type 2 diabetes-associated fatty acid binding protein 2 promoter haplotypes are differentially regulated by GATA factors. Hum Mutat 2007; 29:142-9. [DOI: 10.1002/humu.20618] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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253
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Sulsky R, Magnin DR, Huang Y, Simpkins L, Taunk P, Patel M, Zhu Y, Stouch TR, Bassolino-Klimas D, Parker R, Harrity T, Stoffel R, Taylor DS, Lavoie TB, Kish K, Jacobson BL, Sheriff S, Adam LP, Ewing WR, Robl JA. Potent and selective biphenyl azole inhibitors of adipocyte fatty acid binding protein (aFABP). Bioorg Med Chem Lett 2006; 17:3511-5. [PMID: 17502136 DOI: 10.1016/j.bmcl.2006.12.044] [Citation(s) in RCA: 117] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2006] [Revised: 12/12/2006] [Accepted: 12/13/2006] [Indexed: 01/10/2023]
Abstract
Herein we report the first disclosure of biphenyl azoles that are nanomolar binders of adipocyte fatty acid binding protein (aFABP or aP2) with up to thousand-fold selectivity against muscle fatty acid binding protein and epidermal fatty acid binding protein. In addition a new radio-ligand to determine binding against the three fatty acid binding proteins was also synthesized.
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Affiliation(s)
- Richard Sulsky
- Department of Metabolic Disease Chemistry, Bristol Myers-Squibb Pharmaceutical Research Institute, PO Box 5400, Princeton, NJ 08543-5400, USA.
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254
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Abstract
S100A7, also called psoriasin, is a member of the S100 multigene family that is encoded in the epidermal differentiation complex on chromosome 1q21. S100A7 is highly expressed in epidermal hyperproliferative disease; however, its function is not well understood. These studies show high levels of monomer and covalently crosslinked high molecular weight S100A7 in human wound exudate and granulation tissue. Immunohistological studies suggest that this S100A7 is produced by keratinocytes surrounding the wound and is released into the wound exudate. S100A7 is also detected in keratinocyte-conditioned cell culture medium. Studies using recombinant S100A7 indicate that it adheres to and reduces E. coli survival. Mutation of the conserved carboxyl-terminal EF-hand calcium-binding motif or heat denaturation slightly reduces S100A7 antibacterial activity; however, the antibacterial activity is destroyed by protease treatment. Mutation of the zinc-binding motif, located at the C-terminus, reduces antibacterial activity; however, this reduction can be reversed by simultaneous removal of the amino terminus. This indicates the surprising finding that the central region of S100A7, including only amino acids 35-80, is sufficient for full antibacterial activity. These studies also indicate that reduced S100A7 association with bacteria is associated with reduced antibacterial activity.
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Affiliation(s)
- Kathleen C Lee
- Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106-4970, USA
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255
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Stejskal D, Karpisek M. Adipocyte fatty acid binding protein in a Caucasian population: a new marker of metabolic syndrome? Eur J Clin Invest 2006; 36:621-5. [PMID: 16919044 DOI: 10.1111/j.1365-2362.2006.01696.x] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Adipocyte fatty acid binding protein (A-FABP) has been suggested as playing an important role in the pathogenesis of metabolic syndrome. The aim of this study was to evaluate serum A-FABP as a marker of metabolic syndrome and to assess its predictive accuracy in a Caucasian population. Anthropometric and serum analyses were performed for body mass index (BMI), waist circumference, A-FABP, insulin, triglycerides, total cholesterol, high-density lipoprotein-cholesterol (HDL-c), low-density lipoprotein-cholesterol (LDL-c), uric acid, and glucose on 67 non-obese, healthy subjects and 71 subjects with metabolic syndrome. Quicki-quantitative insulin sensitivity check index, receiver operating characteristic curve (ROC-curve) and chi(2) analysis were completed. Compared with healthy controls, subjects with metabolic syndrome had a significantly higher A-FABP serum level (mean: 42.4 vs. 23.7 microg L(-1); P < 0.01). The A-FABP serum level correlated with fasting levels of insulin (r = 0.34; P < 0.01), glucose (r = 0.21; P = 0.01), triglycerides (r = 0.4; P < 0.01), BMI (r = 0.57; P < 0.01) and waist circumference (r = 0.51; P < 0.01), but negatively with HDL-c (r = -0.23; P < 0.01) and Quicki (r = -0.32; P < 0.01). The relationship was defined between serum A-FABP level and metabolic syndrome diagnosis with 40% sensitivity and 99% specificity at A-FABP level 16.4 microg L(-1). Serum A-FABP level might be an independent marker of metabolic syndrome in a Caucasian population.
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Affiliation(s)
- D Stejskal
- Sternberk Hospital, Sternberk, Czech Republic.
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256
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Adhikari S, Erol E, Binas B. Increased glucose oxidation in H-FABP null soleus muscle is associated with defective triacylglycerol accumulation and mobilization, but not with the defect of exogenous fatty acid oxidation. Mol Cell Biochem 2006; 296:59-67. [PMID: 16909303 DOI: 10.1007/s11010-006-9298-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2006] [Accepted: 07/26/2006] [Indexed: 01/17/2023]
Abstract
Heart-type fatty acid-binding protein (H-FABP) is a major fatty acid-binding factor in skeletal muscles. Genetic lack of H-FABP severely impairs the esterification and oxidation of exogenous fatty acids in soleus muscles isolated from chow-fed mice (CHOW-solei) and high fat diet-fed mice (HFD-solei), and prevents the HFD-induced accumulation of muscle triacylglycerols (TAGs). Here, we examined the impact of H-FABP deficiency on the relationship between fatty acid utilization and glucose oxidation. Glucose oxidation was measured in isolated soleus muscles in the presence or absence of 1 mM palmitate (simple protocol) or in the absence of fatty acid after preincubation with 1 mM palmitate (complex protocol). With the simple protocol, the mutation slightly reduced glucose oxidation in CHOW-muscles, but markedly increased it in HFD-muscles; unexpectedly, this pattern was not altered by the addition of palmitate, which reduced glucose oxidation in both CHOW- and HFD-solei irrespective of the mutation. In the complex protocol, the mutation first inhibited the synthesis and accumulation of TAGs and then their mobilization; with this protocol, the mutation increased glucose oxidation in both CHOW- and HFD-solei. We conclude: (i) H-FABP mediates a non-acute inhibition of muscle glucose oxidation by fatty acids, likely by enabling both the accumulation and mobilization of a critical mass of muscle TAGs; (ii) H-FABP does not mediate the acute inhibitory effect of extracellular fatty acids on muscle glucose oxidation; (iii) H-FABP affects muscle glucose oxidation in opposing ways, with inhibition prevailing at high muscle TAG contents.
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Affiliation(s)
- Sean Adhikari
- Department of Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, 1197 Raymond Stotzer Pkwy, College Station, TX 77843, USA
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257
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Capaldi S, Guariento M, Perduca M, Di Pietro SM, Santomé JA, Monaco HL. Crystal structure of axolotl (Ambystoma mexicanum) liver bile acid-binding protein bound to cholic and oleic acid. Proteins 2006; 64:79-88. [PMID: 16555310 DOI: 10.1002/prot.20961] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The family of the liver bile acid-binding proteins (L-BABPs), formerly called liver basic fatty acid-binding proteins (Lb-FABPs) shares fold and sequence similarity with the paralogous liver fatty acid-binding proteins (L-FABPs) but has a different stoichiometry and specificity of ligand binding. This article describes the first X-ray structure of a member of the L-BABP family, axolotl (Ambystoma mexicanum) L-BABP, bound to two different ligands: cholic and oleic acid. The protein binds one molecule of oleic acid in a position that is significantly different from that of either of the two molecules that bind to rat liver FABP. The stoichiometry of binding of cholate is of two ligands per protein molecule, as observed in chicken L-BABP. The cholate molecule that binds buried most deeply into the internal cavity overlaps well with the analogous bound to chicken L-BABP, whereas the second molecule, which interacts with the first only through hydrophobic contacts, is more external and exposed to the solvent.
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Affiliation(s)
- Stefano Capaldi
- Biocrystallography Laboratory, Department of Science & Technology, University of Verona, Verona, Italy
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258
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Shum BO, Mackay CR, Gorgun CZ, Frost MJ, Kumar RK, Hotamisligil GS, Rolph MS. The adipocyte fatty acid-binding protein aP2 is required in allergic airway inflammation. J Clin Invest 2006; 116:2183-2192. [PMID: 16841093 PMCID: PMC1501108 DOI: 10.1172/jci24767] [Citation(s) in RCA: 114] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2005] [Accepted: 05/23/2006] [Indexed: 01/10/2023] Open
Abstract
The adipocyte fatty acid-binding protein aP2 regulates systemic glucose and lipid metabolism. We report that aP2, in addition to being abundantly expressed by adipocytes, is also expressed by human airway epithelial cells and shows a striking upregulation following stimulation of epithelial cells with the Th2 cytokines IL-4 and IL-13. Regulation of aP2 mRNA expression by Th2 cytokines was highly dependent on STAT6, a transcription factor with a major regulatory role in allergic inflammation. We examined aP2-deficient mice in a model of allergic airway inflammation and found that infiltration of leukocytes, especially eosinophils, into the airways was highly dependent on aP2 function. T cell priming was unaffected by aP2 deficiency, suggesting that aP2 was acting locally within the lung, and analysis of bone marrow chimeras implicated non-hematopoietic cells, most likely bronchial epithelial cells, as the site of action of aP2 in allergic airway inflammation. Thus, aP2 regulates allergic airway inflammation and may provide a link between fatty acid metabolism and asthma.
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Affiliation(s)
- Bennett O.V. Shum
- Immunology and Inflammation Research Program, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia.
Cooperative Research Centre for Asthma and Airways, Camperdown, New South Wales, Australia.
St. Vincent’s Clinical School, Faculty of Medicine, University of New South Wales, Sydney, New South Wales, Australia.
Division of Biological Sciences and Department of Genetics and Complex Diseases, Harvard School of Public Health, Boston, Massachusetts, USA.
School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, New South Wales, Australia
| | - Charles R. Mackay
- Immunology and Inflammation Research Program, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia.
Cooperative Research Centre for Asthma and Airways, Camperdown, New South Wales, Australia.
St. Vincent’s Clinical School, Faculty of Medicine, University of New South Wales, Sydney, New South Wales, Australia.
Division of Biological Sciences and Department of Genetics and Complex Diseases, Harvard School of Public Health, Boston, Massachusetts, USA.
School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, New South Wales, Australia
| | - Cem Z. Gorgun
- Immunology and Inflammation Research Program, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia.
Cooperative Research Centre for Asthma and Airways, Camperdown, New South Wales, Australia.
St. Vincent’s Clinical School, Faculty of Medicine, University of New South Wales, Sydney, New South Wales, Australia.
Division of Biological Sciences and Department of Genetics and Complex Diseases, Harvard School of Public Health, Boston, Massachusetts, USA.
School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, New South Wales, Australia
| | - Melinda J. Frost
- Immunology and Inflammation Research Program, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia.
Cooperative Research Centre for Asthma and Airways, Camperdown, New South Wales, Australia.
St. Vincent’s Clinical School, Faculty of Medicine, University of New South Wales, Sydney, New South Wales, Australia.
Division of Biological Sciences and Department of Genetics and Complex Diseases, Harvard School of Public Health, Boston, Massachusetts, USA.
School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, New South Wales, Australia
| | - Rakesh K. Kumar
- Immunology and Inflammation Research Program, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia.
Cooperative Research Centre for Asthma and Airways, Camperdown, New South Wales, Australia.
St. Vincent’s Clinical School, Faculty of Medicine, University of New South Wales, Sydney, New South Wales, Australia.
Division of Biological Sciences and Department of Genetics and Complex Diseases, Harvard School of Public Health, Boston, Massachusetts, USA.
School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, New South Wales, Australia
| | - Gökhan S. Hotamisligil
- Immunology and Inflammation Research Program, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia.
Cooperative Research Centre for Asthma and Airways, Camperdown, New South Wales, Australia.
St. Vincent’s Clinical School, Faculty of Medicine, University of New South Wales, Sydney, New South Wales, Australia.
Division of Biological Sciences and Department of Genetics and Complex Diseases, Harvard School of Public Health, Boston, Massachusetts, USA.
School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, New South Wales, Australia
| | - Michael S. Rolph
- Immunology and Inflammation Research Program, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia.
Cooperative Research Centre for Asthma and Airways, Camperdown, New South Wales, Australia.
St. Vincent’s Clinical School, Faculty of Medicine, University of New South Wales, Sydney, New South Wales, Australia.
Division of Biological Sciences and Department of Genetics and Complex Diseases, Harvard School of Public Health, Boston, Massachusetts, USA.
School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, New South Wales, Australia
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259
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Sharma MK, Liu RZ, Thisse C, Thisse B, Denovan-Wright EM, Wright JM. Hierarchical subfunctionalization of fabp1a, fabp1b and fabp10 tissue-specific expression may account for retention of these duplicated genes in the zebrafish (Danio rerio) genome. FEBS J 2006; 273:3216-29. [PMID: 16857010 DOI: 10.1111/j.1742-4658.2006.05330.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Fatty acid-binding protein type 1 (FABP1), commonly termed liver-type fatty acid-binding protein (L-FABP), is encoded by a single gene in mammals. We cloned and sequenced cDNAs for two distinct FABP1s in zebrafish coded by genes designated fabp1a and fabp1b. The zebrafish proteins, FABP1a and FABP1b, show highest sequence identity and similarity to the human protein FABP1. Zebrafish fabp1a and fabp1b genes were assigned to linkage groups 5 and 8, respectively. Both linkage groups show conserved syntenies to a segment of mouse chromosome 6, rat chromosome 4 and human chromosome 2 harboring the FABP1 locus. Phylogenetic analysis further suggests that zebrafish fabp1a and fabp1b genes are orthologs of mammalian FABP1 and most likely arose by a whole-genome duplication event in the ray-finned fish lineage, estimated to have occurred 200-450 million years ago. The paralogous fabp10 gene encoding basic L-FABP, found to date in only nonmammalian vertebrates, was assigned to zebrafish linkage group 16. RT-PCR amplification of mRNA in adults, and in situ hybridization to whole-mount embryos to fabp1a, fabp1b and fapb10 mRNAs, revealed a distinct and differential pattern of expression for the fabp1a, fabp1b and fabp10 genes in zebrafish, suggesting a division of function for these orthogolous and paralogous gene products following their duplication in the vertebrate genome. The differential and complementary expression patterns of the zebrafish fabp1a, fapb1b and fabp10 genes imply a hierarchical subfunctionalization that may account for the retention of both the duplicated fabp1a and fabp1b genes, and the fabp10 gene in the zebrafish genome.
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Affiliation(s)
- Mukesh K Sharma
- Department of Biology, Dalhousie University, Halifax, NS, Canada
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260
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Stentz FB, Kitabchi AE. Palmitic acid-induced activation of human T-lymphocytes and aortic endothelial cells with production of insulin receptors, reactive oxygen species, cytokines, and lipid peroxidation. Biochem Biophys Res Commun 2006; 346:721-6. [PMID: 16782068 DOI: 10.1016/j.bbrc.2006.05.159] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2006] [Accepted: 05/24/2006] [Indexed: 10/24/2022]
Abstract
Diabetic conditions are associated with hyperglycemia and hyperlipidemia, but the role of saturated fatty acids (SFA) vs. unsaturated fatty acids (UFA) in activation of T-lymphocytes and human aortic endothelial cells (HAEC) is not known. We investigated in vitro effects of various concentrations of SFA (palmitate) and UFA (oleic, linoleic, linolenic, and arachidonic) acids in activation of these cells. These cells in presence of palmitate, but not UFA, exhibited time, and concentration-dependent emergence of insulin receptors, GLUT 4 expression, generation of ROS, cytokines, lipid peroxidation, and IRS-1. We conclude that both T-lymphocytes and HAEC share common characteristics in exhibiting activation of these cells to palmitate, but not to UFA, by developing insulin receptors and becoming insulin responsive tissues, a hitherto unknown response to palmitate. We hypothesize that these events may serve as protective defense mechanisms against acute effects of glucotoxicity and lipotoxicity in these cells.
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Affiliation(s)
- Frankie B Stentz
- Division of Endocrinology Diabetes and Metabolism, Department of Medicine, The University of Tennessee Health Science Center, Memphis, TN 38163, USA
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261
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Jordal AEO, Hordvik I, Pelsers M, Bernlohr DA, Torstensen BE. FABP3 and FABP10 in Atlantic salmon (Salmo salar L.)--general effects of dietary fatty acid composition and life cycle variations. Comp Biochem Physiol B Biochem Mol Biol 2006; 145:147-58. [PMID: 16905349 DOI: 10.1016/j.cbpb.2006.05.007] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2005] [Revised: 05/23/2006] [Accepted: 05/24/2006] [Indexed: 11/20/2022]
Abstract
The increased use of dietary plant oil supplementation combined with high dietary lipid loads challenges the lipid transport systems of cultivated fish species. Fatty acid binding proteins (FABPs) have been thoroughly studied as intracellular fatty acid transporters in vertebrates, but no data have been reported in Atlantic salmon. In the present study, comparative characterizations were performed, and dietary influence of plant oil supplementation on FABP3 and FABP10 expression was studied for several tissues in two separate dietary trials. In trial I, groups (6 fish each) were fed diets for 42 weeks (body mass 142+/-1 to 1463+/-83 g) (mean+/-S.D.), containing graded levels of rapeseed oil substituting for fish oil using a linear regression design. In trial II, groups (3 fish each) were fed 100% fish oil or 100% plant oil for 22 months (0.160+/-0.052 to 2523+/-590 g) (mean+/-S.D.) and sampled at regular intervals. Liver and muscle tissues appeared to express several FABPs possibly linked to different metabolic functions. FABPs mRNA expression did not change with dietary inclusion of 75% rapeseed oil, whereas FABP3 protein expression seemed to be affected by dietary rapeseed oil inclusion. Significant changes in red muscle FABP3 mRNA expression correlate to significant changes in total beta-oxidation capacity during the energy consuming process of smoltification.
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Affiliation(s)
- Ann-Elise O Jordal
- National Institute of Nutrition and Seafood Research, P.O. Box 2029 Nordnes, N-5817 Bergen, Norway.
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262
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Ferrington DA, Tran TN, Lew KL, Van Remmen H, Gregerson DS. Different death stimuli evoke apoptosis via multiple pathways in retinal pigment epithelial cells. Exp Eye Res 2006; 83:638-50. [PMID: 16682026 DOI: 10.1016/j.exer.2006.03.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2005] [Revised: 02/01/2006] [Accepted: 03/09/2006] [Indexed: 10/24/2022]
Abstract
Loss of retinal pigment epithelial (RPE) cells via apoptosis plays a prominent role in several retinal degenerative diseases, such as age-related macular degeneration, and with light damage. Strategies for preservation of vision that would interrupt the apoptotic cascade require understanding the molecular events associated with apoptosis. This study investigated the susceptibility of RPE to caspase-dependent and -independent apoptotic pathways when challenged with different stimuli, including oxidants, anti-Fas antibody, and activated cytotoxic T lymphocytes (CTLs). These experiments used novel RPE cell lines developed from wildtype and heterozygous mice with reduced levels of either Mn superoxide dismutatse (SOD) or CuZnSOD. Peroxide and 4-hydroxynonenal induced apoptosis through both caspase-independent and -dependent pathways, respectively. With both oxidants, translocation of apoptosis inducing factor into the nucleus was observed. Cells containing reduced levels of CuZnSOD were the most susceptible to oxidant-induced cell death. Targeted killing by CTLs and activation of the Fas death receptor induced caspase-dependent apoptosis. These results show stimulus-specific activation of either the caspase-dependent or -independent pathway. Since cultured RPE express the protein components required for different apoptotic pathways, they provide a good model system for studying molecular events associated with multiple signals that lead to cell death.
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Affiliation(s)
- Deborah A Ferrington
- Department of Ophthalmology, University of Minnesota, 380 Lions Research Building, 2001 6th Street SE, Minneapolis, MN 55455, USA.
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263
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Chmurzyńska A. The multigene family of fatty acid-binding proteins (FABPs): function, structure and polymorphism. J Appl Genet 2006; 47:39-48. [PMID: 16424607 DOI: 10.1007/bf03194597] [Citation(s) in RCA: 484] [Impact Index Per Article: 26.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
Abstract
Fatty acid-binding proteins (FABPs) are members of the superfamily of lipid-binding proteins (LBP). So far 9 different FABPs, with tissue-specific distribution, have been identified: L (liver), I (intestinal), H (muscle and heart), A (adipocyte), E (epidermal), Il (ileal), B (brain), M (myelin) and T (testis). The primary role of all the FABP family members is regulation of fatty acid uptake and intracellular transport. The structure of all FABPs is similar - the basic motif characterizing these proteins is beta-barrel, and a single ligand (e.g. a fatty acid, cholesterol, or retinoid) is bound in its internal water-filled cavity. Despite the wide variance in the protein sequence, the gene structure is identical. The FABP genes consist of 4 exons and 3 introns and a few of them are located in the same chromosomal region. For example, A-FABP, E-FABP and M-FABP create a gene cluster. Because of their physiological properties some FABP genes were tested in order to identify mutations altering lipid metabolism. Furthermore, the porcine A-FABP and H-FABP were studied as candidate genes with major effect on fatness traits.
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Affiliation(s)
- Agata Chmurzyńska
- Department of Animal Genetics and Breeding, August Cieszkowski Agricultural University of Poznan, Wolynska 33, Poznan 60-637, Poland
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264
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Tan SH, Reverter A, Wang Y, Byrne KA, McWilliam SM, Lehnert SA. Gene expression profiling of bovine in vitro adipogenesis using a cDNA microarray. Funct Integr Genomics 2006; 6:235-49. [PMID: 16470362 DOI: 10.1007/s10142-005-0016-x] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2005] [Revised: 10/04/2005] [Accepted: 10/08/2005] [Indexed: 12/16/2022]
Abstract
The gene expression profile of bovine bone marrow stromal cells undergoing adipogenesis was established using a custom cDNA microarray. Cells that were treated with adipogenic stimulants and those that were not were collected at each of the six time points, and gene expression differences between the treated and untreated samples within each time point were compared using a microarray. Statistical analyses revealed that 158 genes showed a minimum fold change of 2 in at least one of the five post-differentiation time points. These genes are involved in various cellular pathways and functions, including lipogenesis, glycolysis, cytoskeleton remodelling, extracellular matrix, transcription as well as various signalling pathways such as insulin, calcium and wingless signalling. The experiment also identified 17 differentially expressed (DE) microarray elements with no assigned function. Quantitative real-time PCR was employed to validate eight DE genes, and the PCR data were found to reproduce the microarray data for these eight genes. Subsequent gene ontology annotation was able to provide a global overview of the molecular function of DE genes during adipogenesis. This analysis was able to indicate the importance of different gene categories at various stages of adipogenic conversion, thereby providing further insights into the molecular changes during bovine adipogenesis.
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Affiliation(s)
- Siok Hwee Tan
- The Cooperative Research Center for Cattle and Beef Quality, CSIRO Livestock Industries, Queensland Bioscience Precinct, 306 Carmody Road, St. Lucia, Qld 4067, Australia.
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265
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Nixon B, MacIntyre DA, Mitchell LA, Gibbs GM, O'Bryan M, Aitken RJ. The Identification of Mouse Sperm-Surface-Associated Proteins and Characterization of Their Ability to Act as Decapacitation Factors1. Biol Reprod 2006; 74:275-87. [PMID: 16221991 DOI: 10.1095/biolreprod.105.044644] [Citation(s) in RCA: 112] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Mammalian spermatozoa must undergo capacitation before acquiring the ability to fertilize the oocyte. This process is believed to be initiated following the release of surface-associated decapacitation factors that are elaborated by both the epididymis and the male accessory organs. Herein, we report the identification of a number of proteins that are actively released from the surface of mouse spermatozoa during capacitation in vitro. As anticipated, the addition of these factors back to suspensions of mouse spermatozoa was shown to suppress several correlates of the capacitation process. Specifically, they induced a significant, dose-dependent inhibition of the ability of spermatozoa to undergo a progesterone-induced acrosome reaction and to bind to the zona pellucida in vitro. Inhibition of these functions was associated with the suppression of tyrosine phosphorylation in the sperm plasma membrane but had no effect on the phosphorylation of internal proteins in either the sperm head or tail. This inhibitory activity was attributed to a subset of the isolated proteins compromising at least four putative decapacitation factors. These proteins were identified via tandem-mass spectrometry amino acid sequence analysis as plasma membrane fatty acid binding protein, cysteine-rich secretory protein 1 (CRISP1), phosphatidylethanolamine binding protein 1 (PBP), and an unnamed protein product that we have termed decapacitation factor 10 (DF10). Of these proteins, PBP was identified as a primary candidate for a decapacitation factor.
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Affiliation(s)
- Brett Nixon
- Reproductive Science Group, School of Environmental and Life Sciences, University of Newcastle, Callaghan, New South Wales 2308, Australia
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266
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Xu A, Wang Y, Xu JY, Stejskal D, Tam S, Zhang J, Wat NMS, Wong WK, Lam KSL. Adipocyte fatty acid-binding protein is a plasma biomarker closely associated with obesity and metabolic syndrome. Clin Chem 2006; 52:405-13. [PMID: 16423904 DOI: 10.1373/clinchem.2005.062463] [Citation(s) in RCA: 433] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND Adipocyte fatty acid-binding protein (A-FABP) is traditionally thought to be a cytosolic fatty acid chaperone expressed in adipocytes. Mice with targeted disruption of the A-FABP gene exhibit a striking phenotype with strong protection from insulin resistance, hyperglycemia, and atherosclerosis. The clinical relevance of these findings remains to be confirmed. METHODS We used tandem mass spectrometry-based proteomic analysis to identify proteins secreted from adipocytes and present in human serum. We measured serum A-FABP concentrations in 229 persons (121 men and 108 women; age range, 33-72 years), including 100 lean [body mass index (BMI) <25 kg/m2] and 129 overweight/obese individuals (BMI >25 kg/m2) selected from a previous cross-sectional study. RESULTS A-FABP was released from adipocytes and was abundantly present in human serum. Mean (SD) circulating concentrations of A-FABP were significantly higher in overweight/obese than in lean persons [32.3 (14.8) vs 20.0 (9.8) microg/L; P < 0.001]. Age- and sex-adjusted serum A-FABP concentrations correlated positively (P < 0.005) with waist circumference, blood pressure, dyslipidemia, fasting insulin, and the homeostasis model assessment insulin resistance index. Moreover, we observed a significant increase in A-FABP concentrations corresponding with increases in the number of components of the metabolic syndrome (P < 0.05). CONCLUSIONS A-FABP is a circulating biomarker closely associated with obesity and components of the metabolic syndrome, and measurement of serum concentrations of A-FABP might be useful for clinical diagnosis of obesity-related metabolic and cardiovascular disorders.
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Affiliation(s)
- Aimin Xu
- Department of Medicine, University of Hong Kong, Hong Kong, China.
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267
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Friedman R, Nachliel E, Gutman M. Fatty acid binding proteins: same structure but different binding mechanisms? Molecular dynamics simulations of intestinal fatty acid binding protein. Biophys J 2005; 90:1535-45. [PMID: 16361342 PMCID: PMC1367305 DOI: 10.1529/biophysj.105.071571] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Fatty acid binding proteins (FABPs) carry fatty acids (FAs) and other lipids in the cellular environment, and are thus involved in processes such as FA uptake, transport, and oxidation. These proteins bind either one or two ligands in a binding site, which appears to be inaccessible from the bulk. Thus, the entry of the substrate necessitates a conformational change, whose nature is still unknown. A possible description of the ligand binding process is given by the portal hypothesis, which suggests that the FA enters the protein through a dynamic area known as the portal region. On the other hand, recent simulations of the adipocyte lipid binding protein (ALBP) suggested a different entry site (the alternative portal). In this article, we discuss molecular dynamics simulations of the apo-intestinal-FABP (I-FABP) in the presence of palmitate molecule(s) in the simulation box. The simulations were carried out to study whether the FA can enter the protein during the simulations (as in the ALBP) and where the ligand entry site is (the portal region, the alternative portal or a different domain). The analysis of the simulations revealed a clear difference between the ALBP and the I-FABP. In the latter case, the palmitate preferentially adsorbed to the portal region, which was more mobile than the rest of the protein. However, no ligand entry was observed in the multi-nanosecond-long simulations, in contrast to ALBP. These findings suggest that, although the main structural motif of the FABPs is common, the fine details of each individual protein structure grossly modulate its reactivity.
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Affiliation(s)
- Ran Friedman
- Laser Laboratory for Fast Reactions in Biology, Department of Biochemistry, George S. Wise Faculty of Life Sciences, Tel Aviv University, 69978 Tel Aviv, Israel
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268
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Ono T. Studies of the FABP family: a retrospective. Mol Cell Biochem 2005; 277:1-6. [PMID: 16132708 DOI: 10.1007/s11010-005-4816-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2005] [Accepted: 04/01/2005] [Indexed: 12/12/2022]
Abstract
Following my research on the role played by soluble proteins in their function as hydrophobic ligand carriers acting through squalene epoxidase, Dr Odani and I started to work together on low molecular lipid binding proteins. As a result of this collaboration, in 1982 we managed to determine the complete primary structure of Z-protein in rat liver. This was the first report ever to give the complete amino acid sequence of a fatty acid binding protein (FABP). This gave momentum to further such research, and now extensive exploration has been carried out on a whole family of homologous intracellular hydrophobic ligand binding proteins, the product of the expression of an ancient gene family in numerous organisms. Takahashi et al. have determined the primary structures of mammalian FABP family protein in liver, intestine, heart, kidney, and skin through amino acid sequencing as well as through determination of the cDNA sequence. Out of all my research on the FABP family, I believe, my initial study on FABP in liver, my work on kidney FABP, heart type FABP and my discovery of an I-15P (BAPB) and I-FABP application as a diagnostic marker stand out in particular.
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Affiliation(s)
- Teruo Ono
- Department of Dairy Science, Laboratory of Clinical Nutrition, Rakuno Gakuen University, 582-1 Midorimachi Bunkyodai, Ebetsu, 069-8501, Japan,
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269
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Jump DB, Botolin D, Wang Y, Xu J, Christian B, Demeure O. Fatty acid regulation of hepatic gene transcription. J Nutr 2005; 135:2503-6. [PMID: 16251601 DOI: 10.1093/jn/135.11.2503] [Citation(s) in RCA: 331] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Dietary fat regulates gene expression by controlling the activity or abundance of key transcription factors. In vitro binding and cell culture studies have identified many transcription factors as prospective targets for fatty acid regulation, including peroxisome proliferator-activated receptors (PPARalpha, beta, gamma1, and gamma2), sterol regulatory element binding protein-1c (SREBP-1c), hepatic nuclear factors (HNF-4alpha and gamma), retinoid X receptor (RXRalpha), liver X receptor (LXRalpha), and others. In vivo studies established that PPARalpha- and SREBP-1c-regulated genes are key targets for PUFA control of hepatic gene expression. PUFA activate PPARalpha by direct binding, leading to the induction of hepatic fatty acid oxidation. PUFA inhibit hepatic fatty acid synthesis by suppressing SREBP-1c nuclear abundance through several mechanisms, including suppression of SREBP-1c gene transcription and enhancement of proteasomal degradation and mRNA(SREBP1c) decay. Changes in intracellular nonesterified fatty acids (NEFA) correlate well with changes in PPARalpha activity and mRNA(SREBP-1c) abundance. Several mechanisms regulate intracellular NEFA composition, including fatty acid transport, acyl CoA synthetases and thioesterases, fatty acid elongases and desaturases, neutral and polar lipid lipases, and fatty acid oxidation. Many of these mechanisms are regulated by PPARalpha or SREBP-1c. Together, these mechanisms control hepatic lipid composition and affect whole-body lipid composition.
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Affiliation(s)
- Donald B Jump
- Departments of Physiology, Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA.
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270
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Abstract
Cytosolic fatty acid binding proteins (FABPs) are widely expressed fatty acid chaperones. The adipocyte-expressed FABPs are permissive factors for the fat-induced metabolic syndrome, but a similar relevance of the FABPs of heart, muscle, and liver remains unclear. In this article, the known biochemical and physiologic roles of these FABPs are discussed in this context. It is concluded that the observations on adipocyte-expressed FABPs cannot be automatically extended to other tissues. More work is needed to clarify whether the individual or combined inhibition of FABPs is a desirable strategy to treat the metabolic syndrome.
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Affiliation(s)
- Bert Binas
- Department of Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, Raymond Stotzer Parkway, College Station, TX 77843, USA.
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271
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Kawabe K, Saegusa H, Seto K, Urabe H, Motojima K. Peroxisome proliferator-activated receptor alpha and its response element are required but not sufficient for transcriptional activation of the mouse heart-type fatty acid binding protein gene. Int J Biochem Cell Biol 2005; 37:1534-46. [PMID: 15833283 DOI: 10.1016/j.biocel.2005.02.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2004] [Revised: 01/13/2005] [Accepted: 02/01/2005] [Indexed: 11/20/2022]
Abstract
Expression of heart-type fatty acid binding protein is restricted mainly to the skeletal and cardiac muscles and further regulated by peroxisome proliferator-activated receptor alpha. The molecular basis for the muscle-restricted peroxisome proliferator-activated receptor alpha action on the fatty acid binding gene was analyzed using normal and the receptor-null mice and the cultured cells. Two possible peroxisome proliferator-response elements were found in the promoter region of the mouse gene. A gel shift assay showed that both elements were functional. However, neither the tandem repeats of the elements nor the cloned promoter sequence could be activated by peroxisome proliferator-activated receptor alpha and its ligand in the reporter gene assay using cultured cells. The cloned promoter responded to the ligand only in the muscle when the reporter gene was introduced into the mouse muscle. Using a chimeric receptor with the activation domain of herpes virus VP16 protein and the tandem repeats of the elements with or without mutation, the upstream element was finally demonstrated to be potentially involved in the receptor-dependent transcriptional activation. These results suggest that the peroxisome proliferator-response element of the mouse gene is atypical and there is a muscle-specific mechanism to enhance the weak binding of the receptor to the response element to ensure the muscle-specific action of peroxisome proliferator-activated receptor alpha on the heart-type fatty acid binding protein gene promoter.
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Affiliation(s)
- Kowhei Kawabe
- Department of Biochemistry, Meiji Pharmaceutical University, Kiyose, Tokyo 204-8588, Japan
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272
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Abstract
PURPOSE OF REVIEW The global prevalence of obesity is increasing epidemically. Obesity causes an array of health problems, reduces life expectancy, and costs over US dollar 100 billion annually. More than a quarter of the population suffers from an aggregation of co-morbidities, including obesity, atherosclerosis, insulin resistance, dyslipidemias, coagulopathies, hypertension, and a pro-inflammatory state known as the metabolic syndrome. Patients with metabolic syndrome have high risk of atherosclerosis as well as type 2 diabetes and other health problems. Like obesity, atherosclerosis has very limited therapeutic options. RECENT FINDINGS Fatty acid binding proteins integrate metabolic and immune responses and link the inflammatory and lipid-mediated pathways that are critical in the metabolic syndrome. This review will highlight recent studies on fatty acid binding protein-deficient models and several fatty acid binding protein-mediated pathways specifically modified in macrophages, cells that are paramount to the initiation and persistence of cardiovascular lesions. SUMMARY Adipocyte/macrophage fatty acid binding proteins, aP2 and mal1, act at the interface of metabolic and inflammatory pathways. These fatty acid binding proteins are involved in the formation of atherosclerosis predominantly through the direct modification of macrophage cholesterol trafficking and inflammatory responses. In addition to atherosclerosis, these fatty acid binding proteins also exert a dramatic impact on obesity, insulin resistance, type 2 diabetes and fatty liver disease. The creation of pharmacological agents to modify fatty acid binding protein function will provide tissue or cell-type-specific control of these lipid signaling pathways, inflammatory responses, atherosclerosis, and the other components of the metabolic syndrome, therefore offering a new class of multi-indication therapeutic agents.
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Affiliation(s)
- Liza Makowski
- Sarah W. Stedman Nutrition and Metabolism Center, Department of Medicine, Division of Endocrinology, Metabolism, and Nutrition, Duke University Medical Center, Durham, NC 27704, USA
| | - Gökhan S. Hotamisligil
- Department of Genetics and Complex Diseases, Harvard School of Public Health, Boston, MA 02115, USA
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273
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Van Gilst MR, Hadjivassiliou H, Yamamoto KR. A Caenorhabditis elegans nutrient response system partially dependent on nuclear receptor NHR-49. Proc Natl Acad Sci U S A 2005; 102:13496-501. [PMID: 16157872 PMCID: PMC1201344 DOI: 10.1073/pnas.0506234102] [Citation(s) in RCA: 201] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Appropriate response to nutritional stress is critical for animal survival and metabolic health. To better understand regulatory networks that sense and respond to nutritional availability, we developed a quantitative RT-PCR strategy to monitor changes in metabolic gene expression resulting from short-term food deprivation (fasting) in Caenorhabditis elegans. Examining 97 fat and glucose metabolism genes in fed and fasted animals, we identified 18 genes significantly influenced by food withdrawal in all developmental stages. Fasting response genes fell into multiple kinetic classes, with some genes showing significant activation or repression just 1 h after food was removed. As expected, fasting stimulated the expression of genes involved in mobilizing fats for energy production, including mitochondrial beta-oxidation genes. Surprisingly, however, we found that other mitochondrial beta-oxidation genes were repressed by food deprivation. Fasting also affected genes involved in mono- and polyunsaturated fatty acid synthesis: four desaturases were induced, and one stearoyl-CoA desaturase (SCD) was strongly repressed. Accordingly, fasted animals displayed considerable changes in fatty acid composition. Finally, nuclear receptor nhr-49 played a key role in nutritional response, enabling induction of beta-oxidation genes upon food deprivation and facilitating activation of SCD in fed animals. Our characterization of a fasting response system and our finding that nhr-49 regulates a sector within this system provide insight into the mechanisms by which animals respond to nutritional signals.
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Affiliation(s)
- Marc R Van Gilst
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA 94143-2280, USA
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274
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Dalessio PM, Fromholt SE, Ropson IJ. The role of Trp-82 in the folding of intestinal fatty acid binding protein. Proteins 2005; 61:176-83. [PMID: 16080148 DOI: 10.1002/prot.20463] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Multiple phases have been observed during the folding and unfolding of intestinal fatty acid binding protein (WT-IFABP) by stopped-flow fluorescence. Site-directed mutagenesis has been used to examine the role of each of the two tryptophans of this protein in these processes. The unfolding and refolding kinetics of the mutant protein containing only tryptophan 82 (W6Y-IFABP) showed that the tryptophan at this location was critical to the fluorescence signal changes observed throughout the unfolding reaction and early in the refolding reaction. However, the kinetic patterns of the mutant protein containing only tryptophan 6 (W82Y-IFABP) indicated that the tryptophan at this location participated in the fluorescence signal changes observed early in the unfolding reaction and late in the refolding reaction. Together, these data suggest that native-like structure was formed first in the vicinity of tryptophan 82, near the center of the hydrophobic core of this beta-sheet protein, prior to formation of native-like structure in the periphery of the protein.
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Affiliation(s)
- Paula M Dalessio
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033, USA
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275
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Li JY, Kuick R, Thompson RC, Misek DE, Lai YM, Liu YQ, Chai BX, Hanash SM, Gantz I. Arcuate nucleus transcriptome profiling identifies ankyrin repeat and suppressor of cytokine signalling box-containing protein 4 as a gene regulated by fasting in central nervous system feeding circuits. J Neuroendocrinol 2005; 17:394-404. [PMID: 15929745 DOI: 10.1111/j.1365-2826.2005.01317.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The arcuate nucleus of the hypothalamus is a primary site for sensing blood borne nutrients and hormonal messengers that reflect caloric status. To identify novel energy homeostatic genes, we examined RNA extracts from the microdissected arcuate nucleus of fed and 48-h fasted rats using oligonucleotide microarrays. The relative abundance of 118 mRNA transcripts was increased and 203 mRNA transcripts was decreased during fasting. One of the down-regulated mRNAs was ankyrin-repeat and suppressor of cytokine signalling box-containing protein 4 (Asb-4). The predicted structure of Asb-4 protein suggested that it might encode an intracellular regulatory protein, and therefore its mRNA expression was investigated further. Reverse transcription quantitative polymerase chain reaction was used to validate down-regulation of Asb-4 mRNA in the arcuate nucleus of the fasted Sprague-Dawley rat (relative expression of Asb-4 mRNA: fed = 4.66 +/- 0.26; fasted = 3.96 +/- 0.23; n = 4, P < 0.01). Down-regulation was also demonstrated in the obese fa/fa Zucker rat, another model of energy disequilibrium (relative expression of Asb-4 mRNA: lean Zucker = 3.91 +/- 0.32; fa/fa = 2.93 +/- 0.26; n = 5, P < 0.001). In situ hybridisation shows that Asb-4 mRNA is expressed in brain areas linked to energy homeostasis, including the arcuate nucleus, paraventricular nucleus, dorsomedial nucleus, lateral hypothalamus and posterodorsal medial amygdaloid area. Double in situ hybridisation revealed that Asb-4 mRNA colocalises with key energy homeostatic neurones. In the fed state, Asb-4 mRNA is expressed by 95.6% of pro-opiomelanocortin (POMC) neurones and 46.4% of neuropeptide Y (NPY) neurones. By contrast, in the fasted state, the percentage of POMC neurones expressing Asb-4 mRNA drops to 73.2% (P < 0.001). Moreover, the density of Asb-4 mRNA per fasted POMC neurone is markedly decreased. Conversely, expression of Asb-4 mRNA by NPY neurones in the fasted state is modestly increased to 52.7% (P < 0.05). Based on its differential expression, neuroanatomical distribution and colocalisation, we hypothesise that Asb-4 is a gene involved in energy homeostasis.
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Affiliation(s)
- J-Y Li
- Department of Surgery, University of Michigan, Ann Arbor, 48109, USA.
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276
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Maache M, Azzouz S, Diaz de la Guardia R, Alvarez P, Gil R, de Pablos LM, Osuna A. Host humoral immune response to Leishmania lipid-binding protein. Parasite Immunol 2005; 27:227-34. [PMID: 16048642 DOI: 10.1111/j.1365-3024.2005.00773.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
SUMMARY We report on the use of Leishmania donovani lipid-binding proteins (LBPs) as antigens capable of being recognized by serum from immunocompetent patients from southern Spain suffering from visceral leishmaniasis and from Peruvian patients with localized cutaneous leishmaniasis caused by Leishmania braziliensis. The absorbance found by immunoenzymatic techniques gave significantly different results for the serum samples from patients with and without leishmaniasis. Specificity by ELISA testing was 93.2% and sensibility 100%. Dot blots from human patient serum samples or naturally infected dogs from Spain gave similarly significant results. All the human serum samples from individuals with visceral leishmaniasis and the Leishmania-positive canine samples recognized two bands, with molecular weights of 8 and 57 kDa. The serum from individuals with cutaneous leishmaniasis caused by L. braziliensis recognized an additional band of 16 kDa. We discuss the role of Leishmania FABP and compare the immunological reactions found with serum samples from other protozoan infections such as toxoplasma and Chagas as well as bacterial infections such as tuberculosis and syphilis.
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Affiliation(s)
- M Maache
- Instituto de Biotecnología, Grupo de Bioquímica y Parasitología Molecular, Universidad de Granada, Granada, Spain
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277
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Falabella P, Perugino G, Caccialupi P, Riviello L, Varricchio P, Tranfaglia A, Rossi M, Malva C, Graziani F, Moracci M, Pennacchio F. A novel fatty acid binding protein produced by teratocytes of the aphid parasitoid Aphidius ervi. INSECT MOLECULAR BIOLOGY 2005; 14:195-205. [PMID: 15796753 DOI: 10.1111/j.1365-2583.2004.00548.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Aphidius ervi is an endophagous braconid, parasitoid of the pea aphid, Acyrthosiphon pisum. A. ervi teratocytes, deriving from the dissociation of the embryonic serosa, synthesize and release two major proteins into the host haemocoel. The gene of one of these proteins has been cloned and characterized. This gene codes for a 15.8 kDa protein belonging to the fatty acid binding protein (FABP) family, named Ae-FABP (A. ervi-FABP). It is abundantly present in the host haemolymph when the parasitoid larva attains its maximum growth rate. The recombinant Ae-FABP binds to fatty acids in vitro, showing a high affinity to C14-C18 saturated fatty acids and to oleic and arachidonic acid. The possible nutritional role for the parasitoid larva of Ae-FABP is discussed.
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Affiliation(s)
- P Falabella
- Dipartimento di Biologia, Difesa e Biotecnologie Agro-Forestali, Università della Basilicata, Potenza, Italy
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278
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Lytle C, Tod TJ, Vo KT, Lee JW, Atkinson RD, Straus DS. The peroxisome proliferator-activated receptor gamma ligand rosiglitazone delays the onset of inflammatory bowel disease in mice with interleukin 10 deficiency. Inflamm Bowel Dis 2005; 11:231-43. [PMID: 15735429 DOI: 10.1097/01.mib.0000160805.46235.eb] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
AIMS To test whether the peroxisome proliferator-activated receptor gamma (PPARgamma) ligand rosiglitazone (Ro) has therapeutic activity in the IL-10(-/-) mouse model of inflammatory bowel disease (IBD), and to identify the cellular targets and molecular mechanisms of Ro action. METHODS The progression of spontaneous chronic colitis in IL-10(-/-) mice was compared in 5-week-old mice fed a standard diet with or without Ro for 12 weeks. The possible therapeutic effect of Ro was also tested over a 6-week interval in older IL-10(-/-) mice with established IBD. RESULTS Treatment with Ro slowed the onset of spontaneous IBD in IL-10(-/-) mice. Crypt hyperplasia, caused by increased mitotic activity of crypt epithelial cells, was also delayed by Ro. Treatment with Ro significantly decreased expression of interferon gamma (IFNgamma), interleukin 17 (IL-17), tumor necrosis factor alpha, and the inducible nitric oxide synthase mRNA in the colon, whereas expression of IL-12p40 was unchanged. PPARgamma was detected in epithelial cells throughout the crypts and surface. Ro increased expression of PPARgamma protein in these cells, suggesting the existence of a positive feedback loop that would potentiate its action in these cells. Ro also specifically increased expression of a novel PPAR target, aquaporin-8 (AQP8), in differentiated colonic epithelial surface cells, demonstrating that PPARgamma is not only present but also regulates gene expression in these cells in vivo. Finally, Ro was ineffective in improving disease activity in older IL-10(-/-) mice with established IBD. CONCLUSIONS PPARgamma is expressed, and the PPARgamma ligand Ro regulates gene expression in colonic epithelial cells. As a single agent, Ro works best for disease prevention in the IL-10(-/-) mouse model for IBD.
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Affiliation(s)
- Christian Lytle
- Biomedical Sciences Division, Department of Biology, University of California Riverside, Riverside, California 92521-0121, USA
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279
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Folli C, Ramazzina I, Percudani R, Berni R. Ligand-binding specificity of an invertebrate (Manduca sexta) putative cellular retinoic acid binding protein. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2005; 1747:229-37. [PMID: 15698958 DOI: 10.1016/j.bbapap.2004.11.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2004] [Revised: 11/11/2004] [Accepted: 11/17/2004] [Indexed: 11/16/2022]
Abstract
Intracellular lipid-binding proteins (iLBPs) are small cytoplasmic proteins that specifically interact with hydrophobic ligands. Fatty acid-binding proteins (FABPs), cellular retinoic acid-binding proteins (CRABPs) and cellular retinol-binding proteins (CRBPs) belong to the iLBP family. A recently identified insect (Manduca sexta) iLBP has been reported to possibly represent an invertebrate CRABP mimicking the role of CRABPs in vertebrate organisms. The presence in this protein of the characteristic binding triad residues involved in the interaction with ligand carboxylate head groups, a feature pertaining to several FABPs and to CRABPs, and the close phylogenetic relationships with both groups of vertebrate heart-type FABPs and CRBPs/CRABPs, makes it difficult to assign it to either FABPs or CRABPs. However, its negligible interaction with retinoic acid and high affinity (K(d) values in the 10(-8) M range) for fatty acids have been established by means of direct and competitive binding assays. As shown by phylogenetic analysis, the M. sexta iLBP belongs to a wide group of invertebrate iLBPs, which, besides being closely related phylogenetically, share distinctive features, such as the conservation of chemically distinct residues in their amino acid sequences and the ability to bind fatty acids. Our results are in keeping with the lack of cellular retinoid-binding proteins in invertebrates and with their later appearance during the course of chordate evolution.
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Affiliation(s)
- Claudia Folli
- Department of Biochemistry and Molecular Biology, University of Parma, P.co Area delle Scienze 23/A, 43100 Parma, Italy
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280
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Baar RA, Dingfelder CS, Smith LA, Bernlohr DA, Wu C, Lange AJ, Parks EJ. Investigation of in vivo fatty acid metabolism in AFABP/aP2(-/-) mice. Am J Physiol Endocrinol Metab 2005; 288:E187-93. [PMID: 15367400 DOI: 10.1152/ajpendo.00256.2004] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The metabolic impact of the murine adipocyte fatty acid-binding protein (AFABP/aP2) on lipid metabolism was investigated in the AFABP/aP2(-/-) mouse and compared with wild-type C57BL/6J littermates. Mice were weaned on a high-fat diet (59% of energy from fat) and acclimated to meal feeding. Stable isotopes were administered, and indirect calorimetry was performed to quantitate fatty acid flux, dietary fatty acid utilization, and substrate oxidation. Consistent with previous in situ and in vitro studies, fasting serum nonesterified fatty acid (NEFA) release was significantly reduced in AFABP/aP2(-/-) (17.1 +/- 9.0 vs. 51.9 +/- 22.9 mg.kg(-1).min(-1)). AFABP/aP2(-/-) exhibited higher serum NEFA (1.4 +/- 0.6 vs. 0.8 +/- 0.4 mmol/l, AFABP/aP2(-/-) vs. C57BL/6J, respectively) and triacylglycerol (TAG; 0.23 +/- 0.09 vs. 0.13 +/- 0.10 mmol/l) and accumulated more TAG in liver tissue (2.9 +/- 2.3 vs. 1.1 +/- 0.8% wet wt) in the fasted state. For the liver-TAG pool, 16.4 +/- 7.3% of TAG-fatty acids were derived from serum NEFA in AFABP/aP2(-/-). In contrast, a significantly greater portion of C57BL/6J liver-TAG was derived from serum NEFA (42.3 +/- 25.5%) during tracer infusion. For adipose-TAG stores, only 0.29 +/- 0.04% was derived from serum NEFA in AFABP/aP2(-/-), and, in C57BL/6J, 1.85 +/- 0.97% of adipose-TAG was derived from NEFA. In addition, AFABP/aP2(-/-) preferentially oxidized glucose relative to fatty acids in the fed state. These data demonstrate that in vivo disruption of AFABP/aP2(-/-) leads to changes in the following two major metabolic processes: 1) decreased adipose NEFA efflux and 2) preferential utilization of glucose relative to fatty acids.
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Affiliation(s)
- Rachel A Baar
- Department of Food Science and Nutrition, University of Minnesota, 1334 Eckles Ave., St. Paul, MN 55108, USA
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281
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Hagan RM, Worner-Gibbs J, Wilton DC. Tryptophan insertion mutagenesis of liver fatty acid-binding protein: L28W mutant provides important insights into ligand binding and physiological function. J Biol Chem 2004; 280:1782-9. [PMID: 15542605 DOI: 10.1074/jbc.m407131200] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Liver fatty acid-binding protein (FABP) binds a variety of non-polar anionic ligands including fatty acids, fatty acyl CoAs, and bile acids. Previously we prepared charge reversal mutants and demonstrated the importance of lysine residues within the portal region in ligand and membrane binding. We have now prepared several tryptophan-containing mutants within the portal region, and one tryptophan at position 28 (L28W) has proved remarkably effective as an intrinsic probe to further study ligand binding. The fluorescence of the L28W mutant was very sensitive to fatty acid and bile acid binding where a large (up to 4-fold) fluorescence enhancement was obtained. In contrast, the binding of oleoyl CoA reduced tryptophan fluorescence. Positive cooperativity for fatty acid binding was observed while detailed information on the orientation of binding of bile acid derivatives was obtained. The ability of bound oleoyl CoA to reduce the fluorescence of L28W provided an opportunity to demonstrate that fatty acyl CoAs can compete with fatty acids for binding to liver FABP under physiological conditions, further highlighting the role of fatty acyl CoAs in modulating FABP function in the cell.
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Affiliation(s)
- Robert M Hagan
- Division of Biochemistry and Molecular Biology, School of Biological Sciences, University of Southampton, Bassett Crescent East, Southampton SO16 7PX, United Kingdom
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282
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Abstract
Fatty acid-binding proteins (FABPs) belong to the conserved multigene family of the intracellular lipid-binding proteins (iLBPs). These proteins are ubiquitously expressed in vertebrate tissues, with distinct expression patterns for the individual FABPs. Various functions have been proposed for these proteins, including the promotion of cellular uptake and transport of fatty acids, the targeting of fatty acids to specific metabolic pathways, and the participation in the regulation of gene expression and cell growth. Novel genetic tools that have become available in recent years, such as transgenic cell lines, animals, and knock-out mice, have provided the opportunity to test these concepts in physiological settings. Such studies have helped to define essential cellular functions of individual FABP-types or of combinations of several different FABPs. The deletion of particular FABP genes, however, has not led to gross phenotypical changes, most likely because of compensatory overexpression of other members of the iLBP gene family, or even of unrelated fatty acid transport proteins. This review summarizes the properties of the various FABPs expressed in mammalian tissues, and discusses the transgenic and ablation studies carried out to date in a functional context.
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Affiliation(s)
- Norbert H Haunerland
- Department of Biological Sciences, Simon Fraser University, 8888 University Drive, Burnaby, BC, Canada V5A 1S6.
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283
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Jones R, Adel-Alvarez LA, Alvarez OR, Broaddus R, Das S. Arachidonic acid and colorectal carcinogenesis. Mol Cell Biochem 2004. [PMID: 14619964 DOI: 10.1023/a:10260604] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Colorectal carcinoma is a leading cause of cancer related death worldwide. This deadly disease advances through a series of clinical and histopathological stages, initiated by single crypt lesions to small benign tumors and finally to malignancy. Although some progress has been made in elucidating the formation of colorectal tumors at molecular/genetic levels, the possible mechanisms of dietary lipids in inducing and promoting colorectal tumorigenesis are poorly understood. Recent epidemiological studies, however, indicate that lipid-rich diet containing omega-6 fatty acids (i.e. linoleic acid, arachidonic acid, etc.) may somehow be related with the disease process. Rapid metabolism of arachidonic acid, increased activities of phospholipases (i.e. phospholipase-A2s), and the elevated levels of cyclooxygenase (COX) and lipoxygenase (LOX) in colonic cells were reported in various stages of the malignancy, suggesting a possible link between dietary lipids and the incidence of colorectal cancer. The major focus of this review is to delineate the recent findings on enhanced arachidonic acid metabolism and its conversion into eicosanoids during the initiation and progression of colorectal carcinogenesis. In addition, the identification and participation of various phospholipases are also discussed. It is speculated that many of these phospholipases can be used as targets for developing new drugs against colorectal as well as other adenocarcinomas.
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Affiliation(s)
- Raymond Jones
- Department of Biological Sciences, University of Texas at El Paso, El Paso, TX 79968-0519, USA
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284
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Jones R, Adel-Alvarez LA, Alvarez OR, Broaddus R, Das S. Arachidonic acid and colorectal carcinogenesis. Mol Cell Biochem 2004; 253:141-9. [PMID: 14619964 DOI: 10.1023/a:1026060426569] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Colorectal carcinoma is a leading cause of cancer related death worldwide. This deadly disease advances through a series of clinical and histopathological stages, initiated by single crypt lesions to small benign tumors and finally to malignancy. Although some progress has been made in elucidating the formation of colorectal tumors at molecular/genetic levels, the possible mechanisms of dietary lipids in inducing and promoting colorectal tumorigenesis are poorly understood. Recent epidemiological studies, however, indicate that lipid-rich diet containing omega-6 fatty acids (i.e. linoleic acid, arachidonic acid, etc.) may somehow be related with the disease process. Rapid metabolism of arachidonic acid, increased activities of phospholipases (i.e. phospholipase-A2s), and the elevated levels of cyclooxygenase (COX) and lipoxygenase (LOX) in colonic cells were reported in various stages of the malignancy, suggesting a possible link between dietary lipids and the incidence of colorectal cancer. The major focus of this review is to delineate the recent findings on enhanced arachidonic acid metabolism and its conversion into eicosanoids during the initiation and progression of colorectal carcinogenesis. In addition, the identification and participation of various phospholipases are also discussed. It is speculated that many of these phospholipases can be used as targets for developing new drugs against colorectal as well as other adenocarcinomas.
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Affiliation(s)
- Raymond Jones
- Department of Biological Sciences, University of Texas at El Paso, El Paso, TX 79968-0519, USA
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285
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Zimmer JSD, Dyckes DF, Bernlohr DA, Murphy RC. Fatty acid binding proteins stabilize leukotriene A4: competition with arachidonic acid but not other lipoxygenase products. J Lipid Res 2004; 45:2138-44. [PMID: 15342681 DOI: 10.1194/jlr.m400240-jlr200] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Leukotriene A(4) (LTA(4)) is a chemically reactive conjugated triene epoxide product derived from 5-lipoxygenase oxygenation of arachidonic acid. At physiological pH, this reactive compound has a half-life of less than 3 s at 37 degrees C and approximately 40 s at 4 degrees C. Regardless of this aqueous instability, LTA(4) is an intermediate in the formation of biologically active leukotrienes, which can be formed through either intracellular or transcellular biosynthesis. Previously, epithelial fatty acid binding protein (E-FABP) present in RBL-1 cells was shown to increase the half-life of LTA(4) to approximately 20 min at 4 degrees C. Five FABPs (adipocyte FABP, intestinal FABP, E-FABP, heart/muscle FABP, and liver FABP) have now been examined and also found to increase the half-life of LTA(4) at 4 degrees C to approximately 20 min with protein present. Stabilization of LTA(4) was examined when arachidonic acid was present to compete with LTA(4) for the binding site on E-FABP. Arachidonate has an apparent higher affinity for E-FABP than LTA(4) and was able to completely block stabilization of the latter. When E-FABP is not saturated with arachidonate, FABP can still stabilize LTA(4). Several lipoxygenase products, including 5-hydroxyeicosatetraenoic acid, 5,6-dihydroxyeicosatetraenoic acid, and leukotriene B(4), were found to have no effect on the stability of LTA(4) induced by E-FABP even when present at concentrations 3-fold higher than LTA(4).
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286
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Abstract
The S100 proteins comprise a family of 21 low molecular weight (9-13 kDa) proteins that are characterized by the presence of two calcium-binding EF-hand motifs. Fourteen S100 protein genes are located within the epidermal differentiation complex on human chromosome 1q21 and 13 S100 proteins (S100A2, S100A3, S100A4, S100A6, S100A7, S100A8, S100A9, S100A10, S100A11, S100A12, S100A15, S100B, and S100P) are expressed in normal and/or diseased epidermis. S100 proteins exist in cells as anti-parallel hetero- and homodimers and upon calcium binding interact with target proteins to regulate cell function. S100 proteins are of interest as mediators of calcium-associated signal transduction and undergo changes in subcellular distribution in response to extracellular stimuli. They also function as chemotactic agents and may play a role in the pathogenesis of epidermal disease, as selected S100 proteins are markedly overexpressed in psoriasis, wound healing, skin cancer, inflammation, cellular stress, and other epidermal states.
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Affiliation(s)
- Richard L Eckert
- Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106, USA.
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287
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Storey KB, Storey JM. Metabolic rate depression in animals: transcriptional and translational controls. Biol Rev Camb Philos Soc 2004; 79:207-33. [PMID: 15005178 DOI: 10.1017/s1464793103006195] [Citation(s) in RCA: 427] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Metabolic rate depression is an important survival strategy for many animal species and a common element of hibernation, torpor, aestivation, anaerobiosis, diapause, and anhydrobiosis. Studies of the biochemical mechanisms that regulate reversible transitions to and from hypometabolic states are identifying principles of regulatory control that are conserved across phylogenetic lines and that are broadly applied to the control of multiple cell functions. One such mechanism is reversible protein phosphorylation which is now known to contribute to the regulation of fuel metabolism, to ion channel arrest, and to the suppression of protein synthesis during hypometabolism. The present review focuses on two new areas of research in hypometabolism: (1) the role of differential gene expression in supplying protein products that adjust metabolism or protect cell functions for long-term survival, and (2) the mechanisms of protein life extension in hypometabolism involving inhibitory controls of transcription, translation and protein degradation. Control of translation examines reversible phosphorylation regulation of ribosomal initiation and elongation factors, the dissociation of polysomes and storage of mRNA transcripts during hypometabolism, and control over the translation of different mRNA types by differential sequestering of mRNA into polysome versus monosome fractions. The analysis draws primarily from current research on two animal models, hibernating mammals and anoxia-tolerant molluscs, with selected examples from multiple other sources.
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Affiliation(s)
- Kenneth B Storey
- College of Natural Sciences, Institute of Biochemistry, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, Canada K1S 5B6.
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288
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Peterson RL, Casciotti L, Block L, Goad MEP, Tong Z, Meehan JT, Jordan RA, Vinlove MP, Markiewicz VR, Weed CA, Dorner AJ. Mechanistic toxicogenomic analysis of WAY-144122 administration in Sprague–Dawley rats. Toxicol Appl Pharmacol 2004; 196:80-94. [PMID: 15050410 DOI: 10.1016/j.taap.2003.11.016] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2003] [Accepted: 11/06/2003] [Indexed: 11/23/2022]
Abstract
Application of global gene expression analysis in the study of mechanisms of toxicity could provide a more comprehensive interpretation of the molecular basis of drug action. WAY-144122 has pharmacological activity against several targets improving insulin responsiveness and favorably altering lipid profiles. Normal rats treated with suprapharmacological doses of WAY-144122 for 28 days exhibited drug-related effects in the liver and ovary. To determine the molecular mechanism underlying these effects, we employed global gene expression profiling to measure RNA levels in these target organs obtained from WAY-144122-treated rats administered test article for 1, 3, 7, and 14 days. Genes altered in expression by WAY-144122 were functionally categorized and related to their biological activity. In the liver, WAY-144122 caused a widespread up-regulation of genes involved in lipid mobilization, peroxisomal proliferation, and fatty acid beta-oxidation. In the ovary, we observed reduced expression of genes encoding luteinizing hormone receptor, follistatin, and enzymes in the estradiol synthesis pathway. Transcriptional changes in both organs precede histopathological effects. Profiling analysis allowed us to formulate hypotheses for molecular mechanisms underlying the physiological observations. In the liver, transcriptional changes suggest that WAY-144122 induced increased metabolic activity and peroxisomal proliferation resulting in increased liver weight and hepatocellular hypertrophy. We propose decreased estradiol synthesis as the underlying mechanism for the observed follicular atrophy in the ovary. Importantly, in this study, we have identified potential molecular mechanisms of drug effect in expression profiles before observation of physiological changes.
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Affiliation(s)
- R L Peterson
- Discovery Medicine, Wyeth Research, Andover, MA 01810, USA
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289
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Parnis S, Nicoletti C, Ollendorff V, Massey-Harroche D. Enterocytin: A new specific enterocyte marker bearing a B30.2-like domain. J Cell Physiol 2004; 198:441-51. [PMID: 14755549 DOI: 10.1002/jcp.10418] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Enterocyte differentiation is correlated to the expression of specific proteins which only a few of them are identified. In this study, we characterize a new marker of enterocyte differentiation using monoclonal antibodies. We showed that small intestinal enterocytes specifically express a new 47 kDa protein named Enterocytin. Expression of this protein increase along the crypt-villus axis and it is concentrated in the terminal web, lateral plasma membrane domain, and nucleus membrane of mature enterocytes. A 1.8-kb cDNA of Enterocytin was isolated by expression cloning from a cDNA library of rabbit small intestine. The amino acid sequence obtained shows an N-terminal region with a coiled-coil structure and a B30.2-like domain in the C-terminus region. By co-transfection and immunoprecipitation procedures on Cos cells, it was observed that the coiled-coil domain is involved in the homodimerization of Enterocytin. In the human intestine, a similar 47 kDa protein was detected, exclusively in the small intestinal enterocytes. In addition, expression of this protein in Caco2 cells is correlated with the state of differentiation of these cells. The restricted expression of Enterocytin in the intestine and its localization in mature cells suggest that it may contribute to the differentiation processes and maintenance of the enterocytic polarity.
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Affiliation(s)
- Stéphane Parnis
- Institut Méditerranéen de Recherche en Nutrition, Faculté des Sciences de Saint Jérôme, Avenue Escadrille Normandie-Niemen, Marseille cedex, France
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290
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Eddy SF, Storey KB. Up-regulation of fatty acid-binding proteins during hibernation in the little brown bat, Myotis lucifugus. ACTA ACUST UNITED AC 2004; 1676:63-70. [PMID: 14732491 DOI: 10.1016/j.bbaexp.2003.10.008] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Hibernating animals rely primarily on lipids throughout winter as their primary fuel source, thus it is hypothesized that an increase in genes and proteins relating to lipid transport will increase accordingly. The cloning and expression of heart type fatty acid-binding protein (h-fabp) from a mammalian hibernator, the little brown bat Myotis lucifugus, is presented. Northern blot analysis revealed that transcript levels of h-fabp were significantly higher during hibernation in brown adipose tissue and skeletal muscle compared with levels in euthermic bats. Similarly, heterologous probing with rat adipose type a-fabp found 3.9-fold higher levels of a-fabp transcripts in brown adipose from hibernating animals. Levels of A- and H-FABP protein were quantified in tissues of euthermic versus hibernating animals by Western blotting. A-FABP was 4-fold higher in brown adipose of hibernating, compared with euthermic bats, whereas H-FABP was significantly higher in hibernator brown adipose, heart and skeletal muscle. The present work implicates FABPs as important elements related to the hibernating state in mammals; alterations in gene and protein expression along with amino acid substitutions are shown. These likely contribute to optimizing the function of FABPs at the low body temperatures (near 0 degrees C) experienced in the hibernating state.
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Affiliation(s)
- Sean F Eddy
- Department of Chemistry and Institute of Biochemistry, Carleton University, 1125 Colonel By Drive, Ottawa, ON, Canada K1S 5B6.
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291
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Erol E, Kumar LS, Cline GW, Shulman GI, Kelly DP, Binas B. Liver fatty acid binding protein is required for high rates of hepatic fatty acid oxidation but not for the action of PPARalpha in fasting mice. FASEB J 2003; 18:347-9. [PMID: 14656998 DOI: 10.1096/fj.03-0330fje] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Liver fatty acid binding protein (L-FABP) has been proposed to limit the availability of long-chain fatty acids (LCFA) for oxidation and for peroxisome proliferator-activated receptor alpha (PPAR-alpha), a fatty acid binding transcription factor that determines the capacity of hepatic fatty acid oxidation. Here, we used L-FABP null mice to test this hypothesis. Under fasting conditions, this mutation reduced beta-hydroxybutyrate (BHB) plasma levels as well as BHB release and palmitic acid oxidation by isolated hepatocytes. However, the capacity for ketogenesis was not reduced: BHB plasma levels were restored by octanoate injection; BHB production and palmitic acid oxidation were normal in liver homogenates; and hepatic expression of key PPAR-alpha target (MCAD, mitochondrial HMG CoA synthase, ACO, CYP4A3) and other (CPT1, LCAD) genes of mitochondrial and extramitochondrial LCFA oxidation and ketogenesis remained at wild-type levels. During standard diet, mitochondrial HMG CoA synthase mRNA was selectively reduced in L-FABP null liver. These results suggest that under fasting conditions, hepatic L-FABP contributes to hepatic LCFA oxidation and ketogenesis by a nontranscriptional mechanism, whereas L-FABP can activate ketogenic gene expression in fed mice. Thus, the mechanisms whereby L-FABP affects fatty acid oxidation may vary with physiological condition.
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Affiliation(s)
- Erdal Erol
- Department of Pathobiology, College of Veterinary Medicine, Texas A&M University, Raymond Stotzer Pkwy, College Station, Texas 77843-4467, USA
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292
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Newberry EP, Xie Y, Kennedy S, Han X, Buhman KK, Luo J, Gross RW, Davidson NO. Decreased Hepatic Triglyceride Accumulation and Altered Fatty Acid Uptake in Mice with Deletion of the Liver Fatty Acid-binding Protein Gene. J Biol Chem 2003; 278:51664-72. [PMID: 14534295 DOI: 10.1074/jbc.m309377200] [Citation(s) in RCA: 221] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Liver fatty acid-binding protein (L-Fabp) is an abundant cytosolic lipid-binding protein with broad substrate specificity, expressed in mammalian enterocytes and hepatocytes. We have generated mice with a targeted deletion of the endogenous L-Fabp gene and have characterized their response to alterations in hepatic fatty acid flux following prolonged fasting. Chow-fed L-Fabp-/- mice were indistinguishable from wild-type littermates with regard to growth, serum and tissue lipid profiles, and fatty acid distribution within hepatic complex lipid species. In response to 48-h fasting, however, wild-type mice demonstrated a approximately 10-fold increase in hepatic triglyceride content while L-Fabp-/- mice demonstrated only a 2-fold increase. Hepatic VLDL secretion was decreased in L-Fabp-/- mice suggesting that the decreased accumulation of hepatic triglyceride was not the result of increased secretion. Fatty acid oxidation, as inferred from serum beta-hydroxybutyrate levels, was increased in response to fasting, although the increase in L-Fabp-/- mice was significantly reduced in comparison to wild-type controls, despite comparable induction of PPAR alpha target genes. Studies in primary hepatocytes revealed indistinguishable initial rates of oleate uptake, but longer intervals revealed reduced rates of uptake in fasted L-Fabp-/- mice. Oleate incorporation into cellular triglyceride and diacylglycerol was reduced in L-Fabp-/- mice although incorporation into phospholipid and cholesterol ester was no different than wild-type controls. These data point to an inducible defect in fatty acid utilization in fasted L-Fabp-/- mice that involves targeting of substrate for use in triglyceride metabolism.
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Affiliation(s)
- Elizabeth P Newberry
- Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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293
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Maxwell KN, Soccio RE, Duncan EM, Sehayek E, Breslow JL. Novel putative SREBP and LXR target genes identified by microarray analysis in liver of cholesterol-fed mice. J Lipid Res 2003; 44:2109-19. [PMID: 12897189 DOI: 10.1194/jlr.m300203-jlr200] [Citation(s) in RCA: 291] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
High-cholesterol diets elicit changes in gene expression via such transcription factors as sterol-regulatory element binding proteins (SREBPs) and liver X receptors (LXRs). We used Affymetrix microarrays to identify genes in mouse liver regulated by dietary cholesterol (0.0% vs. 0.5% cholesterol wt/wt). Three independent experiments were performed, and data were analyzed with Affymetrix Microarray Suite and ANOVA statistical software. There were 69 unique Unigene clusters consistently regulated by dietary cholesterol (37 downregulated and 32 upregulated). The array results were confirmed by quantitative RT-PCR (Q-PCR) for seven of nine downregulated genes and five of six upregulated genes. A time course of dietary cholesterol feeding over 1 week revealed different temporal patterns of gene regulation for these confirmed genes. Six downregulated genes were examined in transgenic mice overexpressing truncated nuclear forms of SREBP-1a and SREBP-2, and all were induced in these mice. A second microarray analysis of mice treated with the LXR agonist TO901317 confirmed that 13 of the 32 cholesterol upregulated genes were also LXR-activated. This array result was confirmed by Q-PCR for three of three genes. In summary, these studies identified and confirmed six novel dietary cholesterol-regulated genes, three putative SREBP target genes (calcium/calmodulin-dependent protein kinase 1D, fatty acid binding protein 5, and proprotein convertase subtilisin/kexin 9), and three putative LXR target genes (a disintegrin and metalloprotease domain 11, apoptosis-inhibitory 6, and F-box-only protein 3).
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Affiliation(s)
- Kara N Maxwell
- Laboratory of Biochemical Genetics and Metabolism, The Rockefeller University, 1230 York Avenue, Box 179, New York, NY 10021, USA
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294
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Bonné A, Gösele C, den Bieman M, Gillissen G, Kreitler T, Pravenec M, Kren V, van Lith H, van Zutphen B. Sequencing and chromosomal localization of Fabp6 and an intronless Fabp6 segment in the rat. Mol Biol Rep 2003; 30:173-6. [PMID: 12974472 DOI: 10.1023/a:1024968606162] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The fatty acid binding protein 6 gene (Fabp6) codes for ileal lipid binding protein. After sequencing of rat Fabp6, the gene was localized in a radiation hybrid (RH) map on chromosome 10. An intronless Fabp6 segment was found in four related rat inbred strains (SHR; SHRSP; WKY; and OKA), but not in 62 other rat inbred strains. The intronless Fabp6 segment, which might be a pseudogene of Fabp6, was localized on rat chromosome 15.
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Affiliation(s)
- Anita Bonné
- Department of Laboratory Animal Science, Faculty of Veterinary Science, Utrecht University, P.O. Box 80166, 3508 TD Utrecht, The Netherlands.
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295
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Liu RZ, Denovan-Wright EM, Wright JM. Structure, linkage mapping and expression of the heart-type fatty acid-binding protein gene (fabp3 ) from zebrafish (Danio rerio). EUROPEAN JOURNAL OF BIOCHEMISTRY 2003; 270:3223-34. [PMID: 12869198 DOI: 10.1046/j.1432-1033.2003.03705.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
We have determined the cDNA nucleotide sequence, deduced the amino acid sequence and defined the gene structure for the cellular heart-type (H-FABP) or fatty acid-binding protein 3 (FABP3) from zebrafish. The zebrafish FABP3 exhibited the greatest amino acid sequence identity to fish and mammalian heart-type FABPs. 3' RACE and 5' RLM-RACE mapped two alternative polyadenylation sites and three transcription start sites, respectively. Southern blot and hybridization analysis indicated that a single fabp3 gene exists in the zebrafish genome. The zebrafish fabp3 gene consists of four exons interrupted by three introns with identical exon/intron structure and coding capacity with that of orthologous mammalian H-FABP genes. Radiation hybrid mapping assigned the zebrafish fabp3 gene to linkage group 19 of the zebrafish genome. Comparative genomic analysis revealed conserved syntenies of the zebrafish fabp3 gene and the orthologous human and mouse fabp3 genes. Northern blot analysis detected an mRNA transcript of 780 nucleotides. In situ hybridization of the zebrafish fabp3-specific oligonucleotide probe to tissue sections of adult zebrafish revealed that the fabp3 mRNA was localized in the ovary and liver, but not in the heart, muscle or brain as reported for the mammalian fabp3 gene transcript. RT-PCR, however, detected zebrafish fabp3 mRNA in all the tissues examined. Emulsion autoradiography further revealed that the zebrafish fabp3 mRNA was most abundant in primary growth stage (stage I) oocytes and decreased during the oocyte growth phase. The fabp3 mRNA levels were reduced and restricted to the ooplasm of cortical alveolus stage (stage II) oocytes, and nearly undetectable in stage III and matured oocytes. Inspection of the 5' upstream sequence of the zebrafish fabp3 gene revealed a number of cis elements that may be involved in the expression of the zebrafish fabp3 gene in oocytes and liver.
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Affiliation(s)
- Rong-Zong Liu
- Department of Biology, Dalhousie University, Halifax, Nova Scotia, Canada
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Liu RZ, Denovan-Wright EM, Wright JM. Structure, mRNA expression and linkage mapping of the brain-type fatty acid-binding protein gene (FABP7) from zebrafish (Danio rerio). EUROPEAN JOURNAL OF BIOCHEMISTRY 2003; 270:715-25. [PMID: 12581211 DOI: 10.1046/j.1432-1033.2003.03432.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The brain fatty acid-binding protein (B-FABP) is involved in brain development and adult neurogenesis. We have determined the sequence of the gene encoding the B-FABP in zebrafish. The zebrafish B-FABP gene spans 2370 bp and contains four exons interrupted by three introns. The coding sequence of zebrafish B-FABP gene is identical to its cDNA sequence and the coding capacity of each exon is the same as that for the human and mouse B-FABP genes. A 1249 bp sequence 5' upstream of exon 1 of the zebrafish B-FABP gene was cloned and sequenced. Several brain development/growth-associated transcription factor binding elements, including POU-domain binding elements and the proposed lipogenic-associated transcription factor NF-Y elements, were found within the 5' region of the B-FABP gene. RT-PCR analysis using mRNA extracted from different tissues of adult zebrafish demonstrated that the zebrafish B-FABP mRNA was predominant in brain with lower levels in liver, testis and intestine, but not in ovary, skin, heart, kidney and muscle. Quantitative RT-PCR revealed a similar tissue-specific distribution for zebrafish B-FABP mRNA except that very low levels of B-FABP mRNA, normalized to beta-actin mRNA, were detected in the heart and muscle RNA, but not in liver RNA. Zebrafish B-FABP mRNA was detected by RT-PCR in embryos beyond 12 h postfertilization, suggesting a correlation of zebrafish B-FABP mRNA expression with early brain development. Radiation hybrid mapping assigned the zebrafish B-FABP gene to linkage group 17. Conserved syntenies of the zebrafish B-FABP gene and the human and mouse orthologous B-FABP genes were observed by comparative genomic analysis.
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Affiliation(s)
- Rong-Zong Liu
- Department of Biology, Dalhousie University, Halifax, Nova Scotia, Canada
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298
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Cellular uptake of long chain free fatty acids: the structure and function of plasma membrane fatty acid binding protein. ACTA ACUST UNITED AC 2003. [DOI: 10.1016/s1569-2558(03)33004-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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299
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Bennaars-Eiden A, Higgins L, Hertzel AV, Kapphahn RJ, Ferrington DA, Bernlohr DA. Covalent modification of epithelial fatty acid-binding protein by 4-hydroxynonenal in vitro and in vivo. Evidence for a role in antioxidant biology. J Biol Chem 2002; 277:50693-702. [PMID: 12386159 DOI: 10.1074/jbc.m209493200] [Citation(s) in RCA: 110] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
4-Hydroxynonenal (4-HNE) is a cytotoxic alpha,beta-unsaturated acyl aldehyde that is naturally produced from lipid peroxidation and cleavage in response to oxidative stress and aging. Such reactive lipids covalently modify cellular target proteins, thereby affecting biological structure and function. Herein we report the identification of the epithelial fatty acid-binding protein (E-FABP) as a molecular target for 4-HNE modification both in vitro and in vivo. 4-HNE covalently modified (t(12) < 60 s) E-FABP in vitro, as revealed by a combination of matrix-assisted laser desorption ionization-time of flight mass spectrometry and immunochemical reactivity using antibodies directed to 4-HNE-protein conjugates. Identification of Cys-120 as the major site of modification was determined through tandem mass spectral sequencing of tryptic peptides, as well as analysis of E-FABP mutants C120A, C127A, and C120A/C127A. The in vitro modification of Cys-120 by 4-HNE was relatively insensitive to pH (6.4-8.4), and temperature (4-37 degrees C) but was markedly potentiated by noncovalently bound fatty acids. 4-HNE-modified E-FABP was more stable than unmodified E-FABP to chemical denaturation by guanidine hydrochloride, as assessed by changes in intrinsic tryptophan fluorescence. Analysis of soluble protein extracts from rat retina with antibodies directed to 4-HNE-protein conjugates revealed immunoreactivity with a 15-kDa protein that was identified by electrospray ionization and matrix-assisted laser desorption ionization-time of flight mass spectrometry as E-FABP. Evaluation of retinal pigment epithelial cell extracts derived from E-FABP null mice by two-dimensional gel electrophoresis using anti-4-HNE antibodies revealed increased modification in the null cells relative to those from wild type cells. These results indicate that E-FABP is a molecular target for 4-HNE modification and the hypothesis that E-FABP functions as an antioxidant protein by scavenging reactive lipids through covalent modification of Cys-120.
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300
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Davies JK, Hagan RM, Wilton DC. Effect of charge reversal mutations on the ligand- and membrane-binding properties of liver fatty acid-binding protein. J Biol Chem 2002; 277:48395-402. [PMID: 12379651 DOI: 10.1074/jbc.m208141200] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Liver fatty acid-binding protein (FABP) is able to bind to anionic phospholipid vesicles under conditions of low ionic strength. This binding results in the release of ligand, the fluorescent fatty acid analogue 11-dansylaminoundecanoic acid (DAUDA), with loss of fluorescence intensity (Davies, J. K., Thumser, A. E. A., and Wilton, D. C. (1999) Biochemistry 38, 16932-16940). Using a strategy of charge reversal mutagenesis, the potential role of specific cationic residues in promoting interfacial binding of FABP to anionic phospholipid vesicles has been investigated. Cationic residues chosen included those within the alpha-helical region (Lys-20, Lys-31, and Lys-33) and those that make a significant contribution to the positive surface potential of the protein (Lys-31, Lys-36, Lys-47, Lys-57, and Arg-126). Only three cationic residues make a significant contribution to interfacial binding, and these residues (Lys-31, Lys-36, and Lys-57) are all located within the ligand portal region, where the protein may be predicted to exhibit maximum disorder. The binding of tryptophan mutants, F3W, F18W, and C69W, to dioleoylphosphatidylglycerol vesicles, containing 5 mol% of the fluorescent phospholipid dansyldihexadecanoylphosphatidylethanolamine, was monitored by fluorescence resonance energy transfer (FRET). All three mutants showed enhanced dansyl fluorescence due to FRET on addition of phospholipid to protein; however, this fluorescence was considerably greater with the F3W mutant, consistent with the N-terminal region of the protein coming in close proximity to the phospholipid interface. These results were confirmed by succinimide quenching studies. Overall, the results indicate that the portal region of liver FABP and specifically Lys-31, Lys-36, and Lys-57 are involved in the interaction with the interface of anionic vesicles and that the N-terminal region of the protein undergoes a conformational change, resulting in DAUDA release.
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Affiliation(s)
- Joanna K Davies
- Division of Biochemistry and Molecular Biology, School of Biological Sciences, University of Southampton, Bassett Crescent East, United Kingdom
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