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Świątkiewicz M, Oczkowicz M, Ropka-Molik K, Hanczakowska E. The effect of dietary fatty acid composition on adipose tissue quality and expression of genes related to lipid metabolism in porcine livers. Anim Feed Sci Technol 2016. [DOI: 10.1016/j.anifeedsci.2016.03.020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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2
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Yao Y, Lu S, Huang Y, Beeman-Black CC, Lu R, Pan X, Hussain MM, Black DD. Regulation of microsomal triglyceride transfer protein by apolipoprotein A-IV in newborn swine intestinal epithelial cells. Am J Physiol Gastrointest Liver Physiol 2011; 300:G357-63. [PMID: 21127258 PMCID: PMC3043654 DOI: 10.1152/ajpgi.00353.2010] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Apolipoprotein (apo) A-IV overexpression enhances chylomicron (CM) assembly and secretion in newborn swine intestinal epithelial cells by producing larger particles (Lu S, Yao Y, Cheng X, Mitchell S, Leng S, Meng S, Gallagher JW, Shelness GS, Morris GS, Mahan J, Frase S, Mansbach CM, Weinberg RB, Black DD. J Biol Chem 281: 3473-3483, 2006). To determine the impact of apo A-IV on microsomal triglyceride transfer protein (MTTP), IPEC-1 cell lines containing a tetracycline-regulatable expression system were used to overexpress native swine apo A-IV and "piglike" human apo A-IV, a mutant human apo A-IV with deletion of the EQQQ-rich COOH-terminus, previously shown to upregulate basolateral triglyceride (TG) secretion 5-fold and 25-fold, respectively. Cells were incubated 24 h with and without doxycycline and oleic acid (OA, 0.8 mM). Overexpression of the native swine apo A-IV and piglike human apo A-IV increased MTTP lipid transfer activity by 39.7% (P = 0.006) and 53.6% (P = 0.0001), respectively, compared with controls. Changes in mRNA and protein levels generally paralleled changes in activity. Interestingly, native swine apo A-IV overexpression also increased MTTP large subunit mRNA, protein levels, and lipid transfer activity in the absence of OA, suggesting a mechanism not mediated by lipid absorption. Overexpression of piglike human apo A-IV significantly increased partitioning of radiolabeled OA from endoplasmic reticulum (ER) membrane to lumen, suggesting increased net transfer of membrane TG to luminal particles. These results suggest that the increased packaging of TG into nascent CMs in the ER lumen, induced by apo A-IV, is associated with upregulation of MTTP activity at the pretranslational level. Thus MTTP is regulated by apo A-IV in a manner to promote increased packaging of TG into the CM core, which may be important in neonatal fat absorption.
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Affiliation(s)
- Ying Yao
- 1Children's Foundation Research Center at Le Bonheur Children's Medical Center, Department of Pediatrics, University of Tennessee Health Science Center, Memphis, Tennessee; and
| | - Song Lu
- 1Children's Foundation Research Center at Le Bonheur Children's Medical Center, Department of Pediatrics, University of Tennessee Health Science Center, Memphis, Tennessee; and
| | - Yue Huang
- 1Children's Foundation Research Center at Le Bonheur Children's Medical Center, Department of Pediatrics, University of Tennessee Health Science Center, Memphis, Tennessee; and
| | - Casey C. Beeman-Black
- 1Children's Foundation Research Center at Le Bonheur Children's Medical Center, Department of Pediatrics, University of Tennessee Health Science Center, Memphis, Tennessee; and
| | - Rena Lu
- 1Children's Foundation Research Center at Le Bonheur Children's Medical Center, Department of Pediatrics, University of Tennessee Health Science Center, Memphis, Tennessee; and
| | - Xiaoyue Pan
- 2Departments of Cell Biology and Pediatrics, SUNY Downstate Medical Center, Brooklyn, New York
| | - M. Mahmood Hussain
- 2Departments of Cell Biology and Pediatrics, SUNY Downstate Medical Center, Brooklyn, New York
| | - Dennis D. Black
- 1Children's Foundation Research Center at Le Bonheur Children's Medical Center, Department of Pediatrics, University of Tennessee Health Science Center, Memphis, Tennessee; and
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Navarro MA, Acín S, Carnicer R, Guzmán-García MA, Arbonés-Mainar JM, Surra JC, Cebrián JA, Arnal C, Isabel B, López-Bote CJ, Osada J. Response of ApoA-IV in pigs to long-term increased dietary oil intake and to the degree of unsaturation of the fatty acids. Br J Nutr 2007; 92:763-9. [PMID: 15533264 DOI: 10.1079/bjn20041266] [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: 11/11/2022]
Abstract
ApoA-IV is a protein constituent of HDL particles; the gene coding for it is a member of the ApoA-I–ApoC-III–ApoA-IV cluster. To investigate the effects of the quantity and the degree of saturation of dietary lipid on the long-term response of this Apo, and on the hypothetical coordinated regulation of the clusterin vivo, pigs were fed isoenergetic, cholesterol-free, low-lipid or lipid-enriched diets (containing either extra olive oil (rich in MUFA) or sunflower oil (rich inn−6 PUFA)) for 42 d. In animals fed on the control diet, ApoA-IV was mainly associated with plasma lipoproteins. An increase in plasma ApoA-IV concentration, mainly in the lipoprotein-free fraction, was induced by the lipid-enriched diets, independent of the degree of saturation of the fatty acids involved. The latter diets also led to increases in hepatic ApoA-I, ApoA-IV and ApoC-III mRNA levels, more so with the sunflower oil-rich diet. The present results show that porcine plasma ApoA-IV levels and their association with lipoproteins are very sensitive to increases in dietary lipids, independent of the degree of fatty acid saturation. Furthermore, hepatic expression of RNA appears to be coordinated along with that of the other members of the gene cluster.
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Affiliation(s)
- María A Navarro
- Departamento de Bioquímica y Biología Molecular y Celular, Universidad de Zaragoza, Spain
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Guillén N, Navarro MA, Surra JC, Arnal C, Fernández-Juan M, Cebrián-Pérez JA, Osada J. Cloning, characterization, expression and comparative analysis of pig Golgi membrane sphingomyelin synthase 1. Gene 2006; 388:117-24. [PMID: 17156943 DOI: 10.1016/j.gene.2006.10.013] [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] [Received: 06/12/2006] [Revised: 10/13/2006] [Accepted: 10/17/2006] [Indexed: 11/26/2022]
Abstract
Pig sphingomyelin synthase 1 (SMS1) cDNA was cloned, characterized and compared to the human ortholog. Porcine protein consists of 413 amino acids and displays a 97% sequence identity with human protein. A phylogenic tree of proteins reveals that porcine SMS1 is more closely related to bovine and rodent proteins than to human. Analysis of protein mass was higher than the theoretical prediction based on amino acid sequence suggesting a kind of posttranslational modification. Quantitative representation of tissue distribution obtained by real-time RT-PCR showed that it was widely expressed although important variations in levels were obtained among organs. Thus, the cardiovascular system, especially the heart, showed the highest value of all the tissues studied. Regional differences of expression were observed in the central nervous system and intestinal tract. Analysis of the hepatic mRNA and protein expressions of SMS1 following turpentine treatment revealed a progressive decrease in the former paralleled by a decrease in the protein concentration. These findings indicate the variation in expression in the different tissues might suggest a different requirement of Golgi sphingomyelin for the specific function in each organ and a regulation of the enzyme in response to turpentine-induced hepatic injury.
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Affiliation(s)
- Natalia Guillén
- Departamento de Bioquímica y Biología Molecular y Celular, Facultad de Veterinaria, Universidad de Zaragoza, Miguel Servet 177, E-50013 Zaragoza, Spain
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5
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Lu S, Yao Y, Cheng X, Mitchell S, Leng S, Meng S, Gallagher JW, Shelness GS, Morris GS, Mahan J, Frase S, Mansbach CM, Weinberg RB, Black DD. Overexpression of apolipoprotein A-IV enhances lipid secretion in IPEC-1 cells by increasing chylomicron size. J Biol Chem 2005; 281:3473-83. [PMID: 16338933 DOI: 10.1074/jbc.m502501200] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Intestinal apolipoprotein A-IV expression is highly regulated by dietary lipid in newborn swine, suggesting a role in lipid absorption. Constitutive overexpression of apoA-IV in newborn swine enterocytes enhances basolateral secretion of triacylglycerol (TG) in TG-rich lipoproteins 4.9-fold (Lu, S., Yao, Y., Meng, S., Cheng, X., and Black, D. D. (2002) J. Biol. Chem. 277, 31929-31937). To investigate the mechanism of this enhancement, IPEC-1 cells were transfected with a tetracycline-regulatable expression system (Tet-On). In cells incubated with oleic acid, a dose response relationship was observed between medium doxycycline concentration and basolateral apoA-IV and TG secretion. Similarly regulated expression of apoA-I did not enhance lipid secretion. The mean diameter of TG-rich lipoproteins secreted from doxycycline-treated cells was larger than from untreated cells (87.0 nm versus 53.4 nm). Basolateral apoB secretion decreased. Using the same expression system, full-length human apoA-IV (376 amino acids); a "pig-like" human apoA-IV, lacking the C-terminal EQQQ repeats (361 amino acids); and a "chicken-like" apoA-IV, further truncated to 343 amino acids, were expressed in IPEC-1 cells. With increasing protein secretion, cells expressing the full-length human apoA-IV displayed a 2-fold increase in TG secretion; in sharp contrast, cells expressing the pig-like human apoA-IV displayed a 25-fold increase in TG secretion and a 27-fold increase in lipoprotein diameter. When human apoA-IV was further truncated to yield a chicken-like protein, TG secretion was inhibited. We conclude that overexpression of swine apoA-IV enhances basolateral TG secretion in a dose-dependent manner by increasing the size of secreted lipoproteins. These data suggest that the region in the human apoA-IV protein from residues 344 to 354 is critical to its ability to enhance lipid secretion, perhaps by enabling the packaging of additional core TG into chylomicron particles. The EQQQ-rich region may play an inhibitory or modulatory role in chylomicron packaging in humans.
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MESH Headings
- Amino Acid Sequence
- Animals
- Animals, Newborn
- Apolipoproteins/chemistry
- Apolipoproteins A/biosynthesis
- Apolipoproteins A/physiology
- Blotting, Western
- Cell Line
- Chickens
- Chylomicrons/chemistry
- Cloning, Molecular
- DNA, Complementary/metabolism
- Dose-Response Relationship, Drug
- Doxycycline/metabolism
- Doxycycline/pharmacology
- Electrophoresis, Polyacrylamide Gel
- Humans
- Immunoprecipitation
- Intestinal Mucosa/metabolism
- Intestines/cytology
- Lipid Metabolism
- Lipids/chemistry
- Lipoproteins/metabolism
- Microscopy, Electron
- Microscopy, Electron, Transmission
- Molecular Sequence Data
- Mutation
- Oleic Acid/chemistry
- Oleic Acid/metabolism
- Protein Structure, Tertiary
- RNA/metabolism
- RNA, Messenger/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
- Swine
- Tetracycline/pharmacology
- Transcriptional Activation
- Triglycerides/metabolism
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Affiliation(s)
- Song Lu
- Children's Foundation Research Center at Le Bonheur Children's Medical Center and Department of Pediatrics, University of Tennessee Health Science Center, Memphis, Tennessee 38103, USA
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Pearson K, Tubb MR, Tanaka M, Zhang XQ, Tso P, Weinberg RB, Davidson WS. Specific Sequences in the N and C Termini of Apolipoprotein A-IV Modulate Its Conformation and Lipid Association. J Biol Chem 2005; 280:38576-82. [PMID: 16159879 DOI: 10.1074/jbc.m506802200] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Apolipoprotein (apoA-IV) is a 376-residue exchangeable apolipoprotein that may play a number of important roles in lipid metabolism, including chylomicron assembly, reverse cholesterol transport, and appetite regulation. In vivo, apoA-IV exists in both lipid-poor and lipid-associated forms, and the balance between these states may determine its function. We examined the structural elements that modulate apoA-IV lipid binding by producing a series of deletion mutants and determining their ability to interact with phospholipid liposomes. We found that the deletion of residues 333-343 strongly increased the lipid association rate versus native apoA-IV. Additional mutagenesis revealed that two phenylalanine residues at positions 334 and 335 mediated this lipid binding inhibitory effect. We also observed that residues 11-20 in the N terminus were required for the enhanced lipid affinity induced by deletion of the C-terminal sequence. We propose a structural model in which these sequences can modulate the conformation and lipid affinity of apoA-IV.
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Affiliation(s)
- Kevin Pearson
- Department of Pathology and Laboratory Medicine, The University of Cincinnati, Cincinnati, Ohio 45237-0507, USA
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Navarro MA, Carpintero R, Acín S, Arbonés-Mainar JM, Calleja L, Carnicer R, Surra JC, Guzmán-García MA, González-Ramón N, Iturralde M, Lampreave F, Piñeiro A, Osada J. Immune-regulation of the apolipoprotein A-I/C-III/A-IV gene cluster in experimental inflammation. Cytokine 2005; 31:52-63. [PMID: 15878672 DOI: 10.1016/j.cyto.2005.03.002] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2004] [Revised: 03/04/2005] [Accepted: 03/23/2005] [Indexed: 01/26/2023]
Abstract
Apolipoprotein A-IV is a member of the apo A-I/C-III/A-IV gene cluster. In order to investigate its hypothetical coordinated regulation, an acute phase was induced in pigs by turpentine oil injection. The hepatic expression of the gene cluster as well as the plasma levels of apolipoproteins were monitored at different time periods. Furthermore, the involvement of the inflammatory mediators' interleukins 1 and 6 and tumor necrosis factor in the regulation of this gene cluster was tested in cultured pig hepatocytes, incubated with those mediators and apo A-I/C-III/A-IV gene cluster expression at the mRNA level was measured. In response to turpentine oil-induced inflammation, a decreased hepatic apo A-IV mRNA expression was observed (independent of apo A-I and apo C-III mRNA) not correlating with the plasma protein levels. The distribution of plasma apo A-IV experienced a shift from HDL to larger particles. In contrast, the changes in apo A-I and apo C-III mRNA were reflected in their corresponding plasma levels. Addition of cytokines to cultured pig hepatocytes also decreased apo A-IV and apo A-I mRNA levels. All these results show that the down-regulation of apolipoprotein A-I and A-IV messages in the liver may be mediated by interleukin 6 and TNF-alpha. The well-known HDL decrease found in many different acute-phase responses also appears in the pig due to the decreased expression of apolipoprotein A-I and the enlargement of the apolipoprotein A-IV-containing HDL.
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Affiliation(s)
- María A Navarro
- Departamento de Bioquímica y Biología Molecular y Celular, Universidad de Zaragoza, Facultad de Veterinaria, Universidad de Zaragoza, Miguel Servet 177, E-50013 Zaragoza, Spain
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8
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Navarro M, Arbonés J, Acín S, Carnicer R, Sarría A, Surra J, Arnal C, Martínez M, Osada J. Animales de experimentación utilizados como modelos en la investigación de la arteriosclerosis. CLINICA E INVESTIGACION EN ARTERIOSCLEROSIS 2005. [DOI: 10.1016/s0214-9168(05)73320-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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