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Khadge S, Sharp JG, Thiele GM, McGuire TR, Klassen LW, Duryee MJ, Britton HC, Dafferner AJ, Beck J, Black PN, DiRusso CC, Talmadge J. Dietary omega-3 and omega-6 polyunsaturated fatty acids modulate hepatic pathology. J Nutr Biochem 2017; 52:92-102. [PMID: 29175671 DOI: 10.1016/j.jnutbio.2017.09.017] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Revised: 09/06/2017] [Accepted: 09/13/2017] [Indexed: 12/13/2022]
Abstract
Recent evidence has suggested that dietary polyunsaturated fatty acids (PUFAs) modulate inflammation; however, few studies have focused on the pathobiology of PUFA using isocaloric and isolipidic diets and it is unclear if the associated pathologies are due to dietary PUFA composition, lipid metabolism or obesity, as most studies compare diets fed ad libitum. Our studies used isocaloric and isolipidic liquid diets (35% of calories from fat), with differing compositions of omega (ω)-6 or long chain (Lc) ω-3 PUFA that were pair-fed and assessed hepatic pathology, inflammation and lipid metabolism. Consistent with an isocaloric, pair-fed model we observed no significant difference in diet consumption between the groups. In contrast, the body and liver weight, total lipid level and abdominal fat deposits were significantly higher in mice fed an ω-6 diet. An analysis of the fatty acid profile in plasma and liver showed that mice on the ω-6 diet had significantly more arachidonic acid (AA) in the plasma and liver, whereas, in these mice ω-3 fatty acids such as eicosapentaenoic acid (EPA) were not detected and docosahexaenoic acid (DHA) was significantly lower. Histopathologic analyses documented that mice on the ω-6 diet had a significant increase in macrovesicular steatosis, extramedullary myelopoiesis (EMM), apoptotic hepatocytes and decreased glycogen storage in lobular hepatocytes, and hepatocyte proliferation relative to mice fed the Lc ω-3 diet. Together, these results support PUFA dietary regulation of hepatic pathology and inflammation with implications for enteral feeding regulation of steatosis and other hepatic lesions.
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Affiliation(s)
- Saraswoti Khadge
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE
| | - John Graham Sharp
- Depatment of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE
| | - Geoffrey M Thiele
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE; Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE; Veteran Affairs Nebraska-Western Iowa Health Care System, Omaha, NE
| | - Timothy R McGuire
- Department of Pharmacy Practice, University of Nebraska Medical Center, Omaha, NE
| | - Lynell W Klassen
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE; Veteran Affairs Nebraska-Western Iowa Health Care System, Omaha, NE
| | - Michael J Duryee
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE
| | - Holly C Britton
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE
| | - Alicia J Dafferner
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE
| | - Jordan Beck
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE
| | - Paul N Black
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE
| | | | - James Talmadge
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE; Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE.
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Monsan P, Bozonnet S, Albenne C, Joucla G, Willemot RM, Remaud-Siméon M. Homopolysaccharides from lactic acid bacteria. Int Dairy J 2001. [DOI: 10.1016/s0958-6946(01)00113-3] [Citation(s) in RCA: 227] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Characterization of dextransucrases fromLeuconostoc mesenteroides NRRL B-1299. Appl Biochem Biotechnol 1997. [DOI: 10.1007/bf02787983] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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5
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MacGregor EA, Jespersen HM, Svensson B. A circularly permuted alpha-amylase-type alpha/beta-barrel structure in glucan-synthesizing glucosyltransferases. FEBS Lett 1996; 378:263-6. [PMID: 8557114 DOI: 10.1016/0014-5793(95)01428-4] [Citation(s) in RCA: 128] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
A motif of amino acid residues, located at the active site and specific beta-strands in alpha-amylases, is recognized in alpha-1,3- and alpha-1,6-glucan-synthesizing glucosyltransferases, leading to the conclusion that these enzymes contain an alpha/beta-barrel closely related to the (beta/alpha)8-fold of the alpha-amylase superfamily. The secondary structure elements of the transferase barrel, however, are circularly permuted to start with an alpha-helix equivalent to helix 3 in the alpha-amylases. Thus, the transferase counterpart of the long third beta-->alpha connection--constituting a domain in the alpha-amylases--is divided to precede and succeed the barrel. This architectural arrangement may be coupled to sucrose scission and glucosyl transfer. The involvement in the mechanism in glucosyltransferases of active site residues recurring in amylolytic enzymes is discussed.
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Affiliation(s)
- E A MacGregor
- Department of Chemistry, University of Manitoba, Winnipeg, Canada
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6
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Mechanism and action of glucansucrases. ACTA ACUST UNITED AC 1996. [DOI: 10.1016/s0921-0423(96)80359-5] [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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7
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Robyt JF. Mechanisms in the glucansucrase synthesis of polysaccharides and oligosaccharides from sucrose. Adv Carbohydr Chem Biochem 1995; 51:133-68. [PMID: 7484361 DOI: 10.1016/s0065-2318(08)60193-6] [Citation(s) in RCA: 100] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- J F Robyt
- Department of Biochemistry and Biophysics, Iowa State University, Ames,USA
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Kobs SF. Acceptor activity of affinity-immobilized dextransucrase from Streptococcus sanguis ATCC 10558. Carbohydr Res 1991; 211:337-42. [PMID: 1722734 DOI: 10.1016/0008-6215(91)80104-u] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- S F Kobs
- Department of Chemistry, Ohio State University, Columbus 43210
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Kobs SF, Mayer RM. Photolabeling of dextransucrase from Streptococcus sanguis with p-azidophenyl alpha-D-glucopyranoside. Carbohydr Res 1991; 211:317-26. [PMID: 1837494 DOI: 10.1016/0008-6215(91)80101-r] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Dextransucrase from Streptococcus sanguis ATCC 10558 was photolabeled using p-azidophenyl alpha-D-glucopyranoside with an apparent rate constant of inactivation of 1.40 min-1. The dissociation constant for this compound, which acts as an acceptor molecule in the enzymatic reaction, is 90 microM. Apparently two acceptor binding sites exist on dextransucrase as shown by (i.) photolabeling the enzyme with p-azidophenyl-alpha-D-[5,6-3H]glucopyranoside and (ii.) fluorescence titration experiments.
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Affiliation(s)
- S F Kobs
- Department of Chemistry, Ohio State University, Columbus 43210
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Minami T, Fujiwara T, Ooshima T, Nakajima Y, Hamada S. Interaction of structural isomers of sucrose in the reaction between sucrose and glucosyltransferases from mutans streptococci. ORAL MICROBIOLOGY AND IMMUNOLOGY 1990; 5:189-94. [PMID: 2150553 DOI: 10.1111/j.1399-302x.1990.tb00644.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Structural isomers of sucrose, i.e. disaccharides composed of glucose and fructose molecules with different glucosidic linkages, were examined for their effect on the reaction between sucrose and various glucosyltransferases (GTases) from Streptococcus mutans MT8148 and Streptococcus sobrinus 6715. Trehalulose (alpha 1-1), turanose (alpha 1-3), maltulose (alpha 1-4), and palatinose (alpha 1-6) were used as the sucrose analogues. Mutans streptococci were found not to utilize these sucrose analogues. Analysis of enzymatic products of GTase and sucrose with thin layer chromatography clearly revealed that glucan synthesis from [14C]sucrose by the various purified GTase preparations from S. mutans and S. sobrinus was inhibited in the presence of these sucrose analogues except turanose, resulting in the release of increased amounts of [14C]fructose and [14C]oligosaccharides. It was also found that the fructose residues in the oligosaccharides were derived from those of sucrose analogues but not sucrose itself. The Lineweaver-Burk plots of the substrate saturation kinetics of GTase vs sucrose indicated increased Km and Vmax in the presence of sucrose analogue, as compared with sucrose alone. Finally, these sucrose analogues except turanose inhibited sucrose dependent cellular adherence of S. sobrinus 6715 to a glass surface, while they scarcely inhibited the adherence of S. mutans MT8148. Among the analogues, maltulose appeared the most effective inhibitor against GTases in general.
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Affiliation(s)
- T Minami
- Osaka University, Research and Development Department, Japan
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Kobs SF, Husman DW, Cawthern KM, Mayer RM. Affinity purification of dextransucrase from Streptococcus sanguis ATCC 10558. Carbohydr Res 1990; 203:156-61. [PMID: 2146014 DOI: 10.1016/0008-6215(90)80055-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- S F Kobs
- Department of Chemistry, Ohio State University, Columbus 43210
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McAlister D, Doyle RJ, Taylor KG. Inhibition by maltose, isomaltose, and nigerose of the synthesis of high-molecular-weight D-glucans by the D-glucosyltransferases of Streptococcus sobrinus. Carbohydr Res 1989; 187:131-8. [PMID: 2526680 DOI: 10.1016/0008-6215(89)80060-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Two D-glucosyltransferases are produced by Streptococcus sobrinus C211. One (GTF-S) catalyzes the conversion of sucrose into soluble alpha-(1----6)-linked alpha-(1----3)-branched D-glucans, and the other (GTF-I), of sucrose into alpha-(1----3)-linked alpha-(1----6)-branched D-glucans. These enzymes were studied by using maltose, isomaltose, and nigerose as inhibitors. Maltose and isomaltose were found to be competitive inhibitors of GTF-S, whereas nigerose has no effect on GTF-S activity. The Ki values for maltose and isomaltose were determined to be 11 and 15mM, respectively. Maltose, isomaltose, and nigerose competitively inhibit GTF-I. The Ki values for these inhibitors were found to be approximately 0.8, 2.5, and 15mM, respectively. The inhibitory properties of each disaccharide are interpreted in terms of conformational comparisons with sucrose.
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Affiliation(s)
- D McAlister
- Department of Microbiology and Immunology, University of Louisville, Kentucky 40292
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Koga T, Horikoshi T, Fujiwara T, Hamada S. Effects of panose on glucan synthesis and cellular adherence by Streptococcus mutans. Microbiol Immunol 1988; 32:25-31. [PMID: 3374403 DOI: 10.1111/j.1348-0421.1988.tb01362.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The effects of panose on glucan synthesis and sucrose-dependent cellular adherence by Streptococcus mutans were investigated. Panose effectively inhibited glucan synthesis from sucrose by glucosyltransferases from S. mutans strain 6715, but increasing amounts of panose increased the release of fructose from sucrose by the enzymes. On the other hand, production of a series of oligosaccharides of increasing size by the enzymes was markedly enhanced in the presence of panose. These results indicate that panose activates the enzymes and that the inhibition of glucan synthesis by panose is due to the transfer of the glucosyl group of sucrose to panose. Sucrose-dependent adherence of cells of various S. mutans strains to a glass surface was also inhibited by panose.
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Affiliation(s)
- T Koga
- Department of Dental Research, National Institute of Health, Tokyo
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Abstract
Dextransucrase, from Streptococcus sanguis ATCC 10558, was immobilized on hydroxylapatite and was "charged" in short pulses with labeled sucrose, as previously described [V. K. Parnaik, G. A. Luzio, D. A. Grahame, S. L. Ditson, and R. M. Mayer (1983) Carbohydr. Res. 121, 257-268]. The "charged" enzyme has been shown to contain both bound glucose and gluco-oligosaccharides. The reactivity of this form of the enzyme has been studied, and shown to have unexpected behavior. Earlier pulse-chase experiments [J. F. Robyt, B. K. Kimble, and T. F. Walseth (1979) Arch. Biochem. Biophys. 165, 634-640; S. L. Ditson and R. M. Mayer (1984) Carbohydr. Res. 126, 170-175], carried out with high concentrations of unlabeled sucrose in the chase, resulted in a rapid decrease in isotope at the reducing termini of enzyme-bound oligosaccharides. However, in the present work, in which the pulsed enzyme was chased with low concentrations of unlabeled sucrose, we observed an increase in the radioactive reducing termini. The possibility that this was due to the enzymatic hydrolysis of dextran has been ruled out. Data presented demonstrate that the enzyme catalyzes the depolymerization of the bound oligosaccharides. Individual glucosyl residues of the oligosaccharides are transferred to acceptors, such as added maltose to form a trisaccharide, or water to form glucose. Similarly, the glucosyl residues can be transferred to added fructose to form sucrose. The studies also provide evidence that the oligosaccharides are slowly released from the enzyme. The ability of the enzyme to catalyze the reverse of the glucosyl transfer reaction involving acceptors was also examined. It was observed that glucose residues transferred by dextransucrase to an acceptor can also be removed to produce sucrose when fructose is added.
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Parnaik VK, Luzio GA, Grahame DA, Ditson SL, Mayer RM. A D-glucosylated form of dextransucrase: preparation and characteristics. Carbohydr Res 1983; 121:257-68. [PMID: 6230150 DOI: 10.1016/0008-6215(83)84022-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Dextransucrase was treated with [14C]sucrose, and the product applied to gel-permeation columns. In the absence of the detergents SDS and Triton X-100, poor recovery of enzyme was observed; however, that enzyme which was recovered was labeled. In the presence of detergents, recovery was increased, but the material appeared to be a large aggregate (mol. wt. greater than 5 X 10(6) ). In addition, the ratio of D-glucose to enzyme suggested that a polymer had been formed. Disc-gel electrophoresis in the presence of a mixture of SDS and Triton X-100 showed similar results, and indicated that the aggregate was disrupted upon treatment with dextranase. Native enzyme that had been immobilized on hydroxylapatite could also be labeled with [14C]sucrose, and the labeling followed saturation kinetics. The labeled protein could be released from the gel with 8M urea, but was aggregated. Radioactive sugars, free from protein, could be released by heating the labeled enzyme. The sugars released consisted of a mixture of D-glucose with oligosaccharides having an average chain-length of 17 D-glucosyl residues. The significance of these observations is discussed.
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