Variant Amino Acid Residues Alter the Enzyme Activity of Peanut Type 2 Diacylglycerol Acyltransferases

PubMed Central

Zheng, Ling; Shockey, Jay; Bian, Fei; Chen, Gao; Shan, Lei; Li, Xinguo; Wan, Shubo; Peng, Zhenying

2017-01-01

Diacylglycerol acyltransferase (DGAT) catalyzes the final step in triacylglycerol (TAG) biosynthesis via the acyl-CoA-dependent acylation of diacylglycerol. This reaction is a major control point in the Kennedy pathway for biosynthesis of TAG, which is the most important form of stored metabolic energy in most oil-producing plants. In this study, Arachis hypogaea type 2 DGAT (AhDGAT2) genes were cloned from the peanut cultivar ‘Luhua 14.’ Sequence analysis of 11 different peanut cultivars revealed a gene family of 8 peanut DGAT2 genes (designated AhDGAT2a-h). Sequence alignments revealed 21 nucleotide differences between the eight ORFs, but only six differences result in changes to the predicted amino acid (AA) sequences. A representative full-length cDNA clone (AhDGAT2a) was characterized in detail. The biochemical effects of altering the AhDGAT2a sequence to include single variable AA residues were tested by mutagenesis and functional complementation assays in transgenic yeast systems. All six mutant variants retained enzyme activity and produced lipid droplets in vivo. The N6D and A26P mutants also displayed increased enzyme activity and/or total cellular fatty acid (FA) content. N6D mutant mainly increased the content of palmitoleic acid, and A26P mutant mainly increased the content of palmitic acid. The A26P mutant grew well both in the presence of oleic and C18:2, but the other mutants grew better in the presence of C18:2. AhDGAT2 is expressed in all peanut organs analyzed, with high transcript levels in leaves and flowers. These levels are comparable to that found in immature seeds, where DGAT2 expression is most abundant in other plants. Over-expression of AhDGAT2a in tobacco substantially increased the FA content of transformed tobacco seeds. Expression of AhDGAT2a also altered transcription levels of endogenous tobacco lipid metabolic genes in transgenic tobacco, apparently creating a larger carbon ‘sink’ that supports increased FA levels. PMID:29085382

Two new lignans from Saururus chinensis and their DGAT inhibitory activity.

PubMed

Li, Na; Tuo, Zhen-Dong; Qi, Shi-Zhou; Xing, Shan-Shan; Lee, Hyun-Sun; Chen, Jian-Guang; Cui, Long

2015-03-01

Two new lignans were isolated from Saururus chinensis, along with eight known compounds. Their structures were elucidated on the basis of spectroscopic and physico-chemical analyses. All the isolates were evaluated for in vitro inhibitory activity against DGAT1 and DGAT2. Among them, compounds 2, 3, 5 and 7 were found to exhibit selective inhibitory activity on DGAT1 with IC50 values ranging from 44.3±1.5 to 87.5±1.3μM. Copyright © 2014 Elsevier B.V. All rights reserved.

Variant amino acid residues alter the enzyme activity of peanut type 2 Diacylglycerol Acyltransferases

USDA-ARS?s Scientific Manuscript database

Diacylglycerol acyltransferase (DGAT) catalyzes the final, rate-limiting step in triacylglycerol (TAG) biosynthesis via the acyl-CoA-dependent acylation of diacylglycerol. In this study, type-2 DGAT2 genes were cloned from eleven peanut cultivars. Sequence analysis revealed at least eight peanut D...

Discovery of a new mechanism for regulation of plant triacylglycerol metabolism: The peanut diacylglycerol acyltransferase-1 gene family transcriptome is highly enriched in alternative splicing variants.

PubMed

Zheng, Ling; Shockey, Jay; Guo, Feng; Shi, Lingmin; Li, Xinguo; Shan, Lei; Wan, Shubo; Peng, Zhenying

2017-12-01

Triacylglycerols (TAGs) are the most important energy storage form in oilseed crops. Diacylglycerol acyltransferase (DGAT) catalyzes the rate-limiting step of the Kennedy pathway of TAG biosynthesis. To date, little is known about the regulation of DGAT activity in peanut (Arachis hypogaea), an agronomically important oilseed crop that is cultivated in many parts of the world. In this study, seven distinct forms of type 1 DGAT (AhDGAT1.1-AhDGAT1.7) were identified, cloned, and characterized. Comparisons of the nucleotide sequences and gene structures revealed many different splicing variants of AhDGAT1, some of which displayed different organ-specific expression patterns. A representative gene (AhDGAT1.1) was transformed into wild-type tobacco and was shown to increase seed fatty acid (FA) content by 14.7%-20.9%. All seven AhDGAT1s were expressed in TAG-deficient Saccharomyces cerevisiae strain H1246; the five longest AhDGAT1 variants generated high levels of acyltransferase activity and complemented the free fatty acid lethality phenotype in this strain. The alternative splicing that gives rise to AhDGAT1.2 and AhDGAT1.4 creates predicted protein C-terminal truncations. The proteins encoded by these two variants were not active and did not complement the fatty acid sensitivity in H1246. These results were verified by visualization of intracellular lipid droplets using Nile Red staining. Collectively, the results presented here represent the first comprehensive analysis of the peanut DGAT1 gene family, which, unlike in other published plant DGAT1 sequences, shows widespread alternative splicing that may affect the expression patterns and enzyme activities of some members of the gene family. Copyright © 2017. Published by Elsevier GmbH.

Type II diacylglycerol acyltransferase from Claviceps purpurea with ricinoleic acid, a hydroxyl fatty acid of industrial importance, as preferred substrate.

PubMed

Mavraganis, Ioannis; Meesapyodsuk, Dauenpen; Vrinten, Patricia; Smith, Mark; Qiu, Xiao

2010-02-01

Claviceps purpurea, the fungal pathogen that causes the cereal disease ergot, produces glycerides that contain high levels of ricinoleic acid [(R)-12-hydroxyoctadec-cis-9-enoic acid] in its sclerotia. Recently, a fatty acid hydroxylase (C. purpurea FAH [CpFAH]) involved in the biosynthesis of ricinoleic acid was identified from this fungus (D. Meesapyodsuk and X. Qiu, Plant Physiol. 147:1325-1333, 2008). Here, we describe the cloning and biochemical characterization of a C. purpurea type II diacylglycerol acyltransferase (CpDGAT2) involved in the assembly of ricinoleic acid into triglycerides. The CpDGAT2 gene was cloned by degenerate RT-PCR (reverse transcription-PCR). The expression of this gene restored the in vivo synthesis of triacylglycerol (TAG) in the quadruple mutant strain Saccharomyces cerevisiae H1246, in which all four TAG biosynthesis genes (DGA1, LRO1, ARE1, and ARE2) are disrupted. In vitro enzymatic assays using microsomal preparations from the transformed yeast strain indicated that CpDGAT2 prefers ricinoleic acid as an acyl donor over linoleic acid, oleic acid, or linolenic acid, and it prefers 1,2-dioleoyl-sn-glycerol over 1,2-dipalmitoyl-sn-glycerol as an acyl acceptor. The coexpression of CpFAH with CpDGAT2 in yeast resulted in an increased accumulation of ricinoleic acid compared to the coexpression of CpFAH with the native yeast DGAT2 (S. cerevisiae DGA1 [ScDGA1]) or the expression of CpFAH alone. Northern blot analysis indicated that CpFAH is expressed solely in sclerotium cells, with no transcripts of this gene being detected in mycelium or conidial cells. CpDGAT2 was more widely expressed among the cell types examined, although expression was low in conidiospores. The high expression of CpDGAT2 and CpFAH in sclerotium cells, where high levels of ricinoleate glycerides accumulate, provided further evidence supporting the roles of CpDGAT2 and CpFAH as key enzymes for the synthesis and assembly of ricinoleic acid in C. purpurea.

Sesquiterpenoids isolated from the flower buds of Tussilago farfara L. inhibit diacylglycerol acyltransferase.

PubMed

Park, Hye Ran; Yoo, Mi Young; Seo, Jee Hee; Kim, Il Soon; Kim, Nam Ye; Kang, Ji Yun; Cui, Long; Lee, Chang-Soo; Lee, Chul-Ho; Lee, Hyun Sun

2008-11-26

Inhibition of acyl CoA:diacylglycerol acyltransferase (DGAT), which is a key enzyme in triglyceride synthesis in eukaryotic organisms, has been proposed as one of the drug targets for treating obesity, type II diabetes mellitus, and metabolic syndrome. Bioassay-guided fractionation of EtOH extract of the flower buds of Tussilago farfara , using an in vitro DGAT enzyme assay, resulted in the isolation of four known sesquiterpenoids, tussilagonone (1), tussilagone (2), 7beta-(3-ethyl-cis-crotonoyloxy)-1alpha-(2-methylbutyryloxy)-3,14-dehydro-Z-notonipetranone (3), and 8-angeloylxy-3,4-epoxy-bisabola-7(14),10-dien-2-one (4). DGAT1 inhibitory activity was studied by in vitro DGAT assay using rat liver microsomes and HepG2 cell microsomes. They showed DGAT1 inhibition with IC(50) values of 99.2 (1), 18.8 (2), 47.0 (3), and 211.1 (4) microM (for rat liver microsomes) and >1 mM (1), 49.1 (2), 160.7 (3), and 294.4 (4) microM (for HepG2 cell microsomes), respectively. Compound 2 showed the most potent inhibition against microsomal DGAT1 derived from rat liver and human hepatocellular carcinoma HepG2 cells and also significantly inhibited triglyceride synthesis by suppressing incorporation of [(14)C]acetate or [(14)C]glycerol into triglycerides in HepG2 cells. These findings suggest that tussilagone is a potential lead compound in the treatment of obesity and type 2 diabetes.

Overexpression of human diacylglycerol acyltransferase 1, acyl-coa:cholesterol acyltransferase 1, or acyl-CoA:cholesterol acyltransferase 2 stimulates secretion of apolipoprotein B-containing lipoproteins in McA-RH7777 cells.

PubMed

Liang, John J; Oelkers, Peter; Guo, Cuiying; Chu, Pi-Chun; Dixon, Joseph L; Ginsberg, Henry N; Sturley, Stephen L

2004-10-22

The relative importance of each core lipid in the assembly and secretion of very low density lipoproteins (VLDL) has been of interest over the past decade. The isolation of genes encoding diacylglycerol acyltransferase (DGAT) and acyl-CoA:cholesterol acyltransferases (ACAT1 and ACAT2) provided the opportunity to investigate the effects of isolated increases in triglycerides (TG) or cholesteryl esters (CE) on apolipoprotein B (apoB) lipoprotein biogenesis. Overexpression of human DGAT1 in rat hepatoma McA-RH7777 cells resulted in increased synthesis, cellular accumulation, and secretion of TG. These effects were associated with decreased intracellular degradation and increased secretion of newly synthesized apoB as VLDL. Similarly, overexpression of human ACAT1 or ACAT2 in McA-RH7777 cells resulted in increased synthesis, cellular accumulation, and secretion of CE. This led to decreased intracellular degradation and increased secretion of VLDL apoB. Overexpression of ACAT2 had a significantly greater impact upon assembly and secretion of VLDL from liver cells than did overexpression of ACAT1. The addition of oleic acid (OA) to media resulted in a further increase in VLDL secretion from cells expressing DGAT1, ACAT1, or ACAT2. VLDL secreted from DGAT1-expressing cells incubated in OA had a higher TG:CE ratio than VLDL secreted from ACAT1- and ACAT2-expressing cells treated with OA. These studies indicate that increasing DGAT1, ACAT1, or ACAT2 expression in McA-RH7777 cells stimulates the assembly and secretion of VLDL from liver cells and that the core composition of the secreted VLDL reflects the enzymatic activity that is elevated.

DGAT1-deficiency affects the cellular distribution of hepatic retinoid and attenuates the progression of CCl4-induced liver fibrosis

PubMed Central

Yuen, Jason J.; Lee, Seung-Ah; Jiang, Hongfeng; Brun, Pierre-Jacques

2015-01-01

Background Diacylglycerol O-acyltransferase 1 (DGAT1) catalyzes the final step of triglyceride synthesis, transferring an acyl group from acyl-CoA to diacylglycerol. DGAT1 also catalyzes the acyl-CoA-dependent formation of retinyl esters in vitro and in mouse intestine and skin. Although DGAT1 is expressed in both hepatocytes and hepatic stellate cells (HSCs), we reported genetic and nutritional studies that established that DGAT1 does not contribute to retinyl ester formation in the liver. Methods We now have explored in more depth the role(s) of DGAT1 in hepatic retinoid metabolism and storage. Results Our data show that DGAT1 affects the cellular distribution between hepatocytes and HSCs of stored and newly absorbed dietary retinol. For livers of Dgat1-deficient mice, a greater percentage of stored retinyl ester is present in HSCs at the expense of hepatocytes. This is also true for newly absorbed oral [3H]retinol. These differences are associated with significantly increased expression, by 2.8-fold, of cellular retinol-binding protein, type I (RBP1) in freshly isolated HSCs from Dgat1-deficient mice, raising the possibility that RBP1, which contributes to retinol uptake into cells and retinyl ester synthesis, accounts for the differences. We further show that the retinyl ester-containing lipid droplets in HSCs are affected in Dgat1-null mice, being fewer in number but, on average, larger than in wild type (WT) HSCs. Finally, we demonstrate that DGAT1 affects experimentally induced HSC activation in vivo but that this effect is independent of altered retinoic acid availability or effects on gene expression. Conclusions Our studies establish that DGAT1 has a role in hepatic retinoid storage and metabolism, but this does not involve direct actions of DGAT1 in retinyl ester synthesis. PMID:26151058

Pharmacological characterization of [trans-5'-(4-amino-7,7-dimethyl-2-trifluoromethyl-7H-pyrimido[4,5-b][1,4]oxazin-6-yl)-2',3'-dihydrospiro(cyclohexane-1,1'-inden)-4-yl]acetic acid monobenzenesulfonate (JTT-553), a novel acyl CoA:diacylglycerol transferase (DGAT) 1 inhibitor.

PubMed

Tomimoto, Daisuke; Okuma, Chihiro; Ishii, Yukihito; Akiyama, Yoshiyuki; Ohta, Takeshi; Kakutani, Makoto; Ohkuma, Yoshiaki; Ogawa, Nobuya

2015-01-01

Acyl CoA:diacylglycerol acyltransferase (DGAT) 1 is an enzyme that catalyzes the final step in triglyceride (TG) synthesis. This enzyme is considered to be a potential therapeutic target for obesity and diabetes. Here, results of an investigation of the pharmacological effects of JTT-553 [trans-5'-(4-amino-7,7-dimethyl-2-trifluoromethyl-7H-pyrimido[4,5-b][1,4]oxazin-6-yl)-2',3'-dihydrospiro(cyclohexane-1,1'-inden)-4-yl]acetic acid monobenzenesulfonate, a novel DGAT1 inhibitor, are reported. To measure the inhibitory activity of JTT-553 against DGAT1, TG synthesis using [(14)C]-labeled oleoyl-CoA was evaluated. Similarly, the inhibitory activity of JTT-553 against DGAT2, an isozyme of DGAT1, and acyl-CoA cholesterol acyltransferase (ACAT) 1, which is highly homologous to DGAT1, were evaluated. JTT-553 selectively inhibited human DGAT1 and showed comparable inhibitory effects on the activity of human, rat, and mouse DGAT. In vivo, JTT-553 suppressed plasma TG and chylomicron TG levels after olive oil loading in Sprague-Dawley (SD) rats. JTT-553 also inhibited TG synthesis in epididymal fat after [(14)C] oleic acid injection in C57BL/6J mice. Food intake was evaluated in SD rats fed 3.1%, 13%, or 35% (w/w) fat diets. In rats fed the 35% fat diet, JTT-553 reduced food intake. This reduction of food intake was observed 2 h after feeding, lasted for 24 h, and correlated with dietary fat content. Furthermore, JTT-553 reduced daily food intake and body weight gain in diet-induced obese rats after 4-week repeated administration. JTT-553 exerted multiple effects on intestinal fat absorption, adipose fat synthesis, and food intake, and consequently induced body weight reduction. Therefore, JTT-553 is expected to be an effective novel therapeutic agent for the treatment of obesity.

An Improved Variant of Soybean Type 1 Diacylglycerol Acyltransferase Increases the Oil Content and Decreases the Soluble Carbohydrate Content of Soybeans[OPEN

PubMed Central

Shen, Bo; Damude, Howard G.; Everard, John D.; Booth, John R.

2016-01-01

Kinetically improved diacylglycerol acyltransferase (DGAT) variants were created to favorably alter carbon partitioning in soybean (Glycine max) seeds. Initially, variants of a type 1 DGAT from a high-oil, high-oleic acid plant seed, Corylus americana, were screened for high oil content in Saccharomyces cerevisiae. Nearly all DGAT variants examined from high-oil strains had increased affinity for oleoyl-CoA, with S0.5 values decreased as much as 4.7-fold compared with the wild-type value of 0.94 µm. Improved soybean DGAT variants were then designed to include amino acid substitutions observed in promising C. americana DGAT variants. The expression of soybean and C. americana DGAT variants in soybean somatic embryos resulted in oil contents as high as 10% and 12%, respectively, compared with only 5% and 7.6% oil achieved by overexpressing the corresponding wild-type DGATs. The affinity for oleoyl-CoA correlated strongly with oil content. The soybean DGAT variant that gave the greatest oil increase contained 14 amino acid substitutions out of a total of 504 (97% sequence identity with native). Seed-preferred expression of this soybean DGAT1 variant increased oil content of soybean seeds by an average of 3% (16% relative increase) in highly replicated, single-location field trials. The DGAT transgenes significantly reduced the soluble carbohydrate content of mature seeds and increased the seed protein content of some events. This study demonstrated that engineering of the native DGAT enzyme is an effective strategy to improve the oil content and value of soybeans. PMID:27208257

Cloning and characterization of an acyl-CoA-dependent diacylglycerol acyltransferase 1 (DGAT1) gene from Tropaeolum majus, and a study of the functional motifs of the DGAT protein using site-directed mutagenesis to modify enzyme activity and oil content.

PubMed

Xu, Jingyu; Francis, Tammy; Mietkiewska, Elzbieta; Giblin, E Michael; Barton, Dennis L; Zhang, Yan; Zhang, Meng; Taylor, David C

2008-10-01

A full-length cDNA encoding a putative diacylglycerol acyltransferase 1 (DGAT1, EC 2.3.1.20) was obtained from Tropaeolum majus (garden nasturtium). The 1557-bp open reading frame of this cDNA, designated TmDGAT1, encodes a protein of 518 amino acids showing high homology to other plant DGAT1s. The TmDGAT1 gene was expressed exclusively in developing seeds. Expression of recombinant TmDGAT1 in the yeast H1246MATalpha quadruple mutant (DGA1, LRO1, ARE1, ARE2) restored the capability of the mutant host to produce triacylglycerols (TAGs). The recombinant TmDGAT1 protein was capable of utilizing a range of (14)C-labelled fatty acyl-CoA donors and diacylglycerol acceptors, and could synthesize (14)C-trierucin. Collectively, these findings confirm that the TmDGAT1 gene encodes an acyl-CoA-dependent DGAT1. In plant transformation studies, seed-specific expression of TmDGAT1 was able to complement the low TAG/unusual fatty acid phenotype of the Arabidopsis AS11 (DGAT1) mutant. Over-expression of TmDGAT1 in wild-type Arabidopsis and high-erucic-acid rapeseed (HEAR) and canola Brassica napus resulted in an increase in oil content (3.5%-10% on a dry weight basis, or a net increase of 11%-30%). Site-directed mutagenesis was conducted on six putative functional regions/motifs of the TmDGAT1 enzyme. Mutagenesis of a serine residue in a putative SnRK1 target site resulted in a 38%-80% increase in DGAT1 activity, and over-expression of the mutated TmDGAT1 in Arabidopsis resulted in a 20%-50% increase in oil content on a per seed basis. Thus, alteration of this putative serine/threonine protein kinase site can be exploited to enhance DGAT1 activity, and expression of mutated DGAT1 can be used to enhance oil content.

An Improved Variant of Soybean Type 1 Diacylglycerol Acyltransferase Increases the Oil Content and Decreases the Soluble Carbohydrate Content of Soybeans.

PubMed

Roesler, Keith; Shen, Bo; Bermudez, Ericka; Li, Changjiang; Hunt, Joanne; Damude, Howard G; Ripp, Kevin G; Everard, John D; Booth, John R; Castaneda, Leandro; Feng, Lizhi; Meyer, Knut

2016-06-01

Kinetically improved diacylglycerol acyltransferase (DGAT) variants were created to favorably alter carbon partitioning in soybean (Glycine max) seeds. Initially, variants of a type 1 DGAT from a high-oil, high-oleic acid plant seed, Corylus americana, were screened for high oil content in Saccharomyces cerevisiae Nearly all DGAT variants examined from high-oil strains had increased affinity for oleoyl-CoA, with S0.5 values decreased as much as 4.7-fold compared with the wild-type value of 0.94 µm Improved soybean DGAT variants were then designed to include amino acid substitutions observed in promising C. americana DGAT variants. The expression of soybean and C. americana DGAT variants in soybean somatic embryos resulted in oil contents as high as 10% and 12%, respectively, compared with only 5% and 7.6% oil achieved by overexpressing the corresponding wild-type DGATs. The affinity for oleoyl-CoA correlated strongly with oil content. The soybean DGAT variant that gave the greatest oil increase contained 14 amino acid substitutions out of a total of 504 (97% sequence identity with native). Seed-preferred expression of this soybean DGAT1 variant increased oil content of soybean seeds by an average of 3% (16% relative increase) in highly replicated, single-location field trials. The DGAT transgenes significantly reduced the soluble carbohydrate content of mature seeds and increased the seed protein content of some events. This study demonstrated that engineering of the native DGAT enzyme is an effective strategy to improve the oil content and value of soybeans. © 2016 American Society of Plant Biologists. All Rights Reserved.

Isolation of diacyl glycerol acyl transferase (DGAT) inhibitors from Pachydictyon coriaceum.

PubMed

Choi, Byoung Wook; Lee, Hyun Sun; Lee, Kyung Bok; Lee, Bong Ho

2011-07-01

The pharmacological inhibition of acyl CoA:diacylglycerol acyltransferase (DGAT, EC 2.3.1.20) has emerged as a target for the treatment of obesity and type 2 diabetes. Chromatographic analysis of the brown alga, Pachydictyon coriaceum, led to the isolation of diterpene dictyol E and hydroxyisocrenulatin. Pharmacological assay of these compounds demonstrated DGAT inhibitory activity with IC₅₀ values of 46.0 μM and 23.3 μM, respectively. Copyright © 2011 John Wiley & Sons, Ltd.

Particle Simulation of Hypersonic Flow

DTIC Science & Technology

1990-04-24

the small volume (this is the same basic concept used in setting up Eq. (2)). Using this interpretation, we can write Eq. (11) as follows zAB dgAt = S...it leads to the expression given by ZAB dgAt = S F(g)dg P, (18) where in this case, we have S nAnB’ (19) 1 + bAB’ and where P, is again given by (17

Evolutionary view of acyl-CoA diacylglycerol acyltransferase (DGAT), a key enzyme in neutral lipid biosynthesis.

PubMed

Turchetto-Zolet, Andreia C; Maraschin, Felipe S; de Morais, Guilherme L; Cagliari, Alexandro; Andrade, Cláudia M B; Margis-Pinheiro, Marcia; Margis, Rogerio

2011-09-20

Triacylglycerides (TAGs) are a class of neutral lipids that represent the most important storage form of energy for eukaryotic cells. DGAT (acyl-CoA: diacylglycerol acyltransferase; EC 2.3.1.20) is a transmembrane enzyme that acts in the final and committed step of TAG synthesis, and it has been proposed to be the rate-limiting enzyme in plant storage lipid accumulation. In fact, two different enzymes identified in several eukaryotic species, DGAT1 and DGAT2, are the main enzymes responsible for TAG synthesis. These enzymes do not share high DNA or protein sequence similarities, and it has been suggested that they play non-redundant roles in different tissues and in some species in TAG synthesis. Despite a number of previous studies on the DGAT1 and DGAT2 genes, which have emphasized their importance as potential obesity treatment targets to increase triacylglycerol accumulation, little is known about their evolutionary timeline in eukaryotes. The goal of this study was to examine the evolutionary relationship of the DGAT1 and DGAT2 genes across eukaryotic organisms in order to infer their origin. We have conducted a broad survey of fully sequenced genomes, including representatives of Amoebozoa, yeasts, fungi, algae, musses, plants, vertebrate and invertebrate species, for the presence of DGAT1 and DGAT2 gene homologs. We found that the DGAT1 and DGAT2 genes are nearly ubiquitous in eukaryotes and are readily identifiable in all the major eukaryotic groups and genomes examined. Phylogenetic analyses of the DGAT1 and DGAT2 amino acid sequences revealed evolutionary partitioning of the DGAT protein family into two major DGAT1 and DGAT2 clades. Protein secondary structure and hydrophobic-transmembrane analysis also showed differences between these enzymes. The analysis also revealed that the MGAT2 and AWAT genes may have arisen from DGAT2 duplication events. In this study, we identified several DGAT1 and DGAT2 homologs in eukaryote taxa. Overall, the data show that DGAT1 and DGAT2 are present in most eukaryotic organisms and belong to two different gene families. The phylogenetic and evolutionary analyses revealed that DGAT1 and DGAT2 evolved separately, with functional convergence, despite their wide molecular and structural divergence.

Evolutionary view of acyl-CoA diacylglycerol acyltransferase (DGAT), a key enzyme in neutral lipid biosynthesis

PubMed Central

2011-01-01

Background Triacylglycerides (TAGs) are a class of neutral lipids that represent the most important storage form of energy for eukaryotic cells. DGAT (acyl-CoA: diacylglycerol acyltransferase; EC 2.3.1.20) is a transmembrane enzyme that acts in the final and committed step of TAG synthesis, and it has been proposed to be the rate-limiting enzyme in plant storage lipid accumulation. In fact, two different enzymes identified in several eukaryotic species, DGAT1 and DGAT2, are the main enzymes responsible for TAG synthesis. These enzymes do not share high DNA or protein sequence similarities, and it has been suggested that they play non-redundant roles in different tissues and in some species in TAG synthesis. Despite a number of previous studies on the DGAT1 and DGAT2 genes, which have emphasized their importance as potential obesity treatment targets to increase triacylglycerol accumulation, little is known about their evolutionary timeline in eukaryotes. The goal of this study was to examine the evolutionary relationship of the DGAT1 and DGAT2 genes across eukaryotic organisms in order to infer their origin. Results We have conducted a broad survey of fully sequenced genomes, including representatives of Amoebozoa, yeasts, fungi, algae, musses, plants, vertebrate and invertebrate species, for the presence of DGAT1 and DGAT2 gene homologs. We found that the DGAT1 and DGAT2 genes are nearly ubiquitous in eukaryotes and are readily identifiable in all the major eukaryotic groups and genomes examined. Phylogenetic analyses of the DGAT1 and DGAT2 amino acid sequences revealed evolutionary partitioning of the DGAT protein family into two major DGAT1 and DGAT2 clades. Protein secondary structure and hydrophobic-transmembrane analysis also showed differences between these enzymes. The analysis also revealed that the MGAT2 and AWAT genes may have arisen from DGAT2 duplication events. Conclusions In this study, we identified several DGAT1 and DGAT2 homologs in eukaryote taxa. Overall, the data show that DGAT1 and DGAT2 are present in most eukaryotic organisms and belong to two different gene families. The phylogenetic and evolutionary analyses revealed that DGAT1 and DGAT2 evolved separately, with functional convergence, despite their wide molecular and structural divergence. PMID:21933415

Dgat1 and Dgat2 regulate enterocyte triacylglycerol distribution and alter proteins associated with cytoplasmic lipid droplets in response to dietary fat

PubMed Central

Hung, Yu-Han; Carreiro, Alicia L.; Buhman, Kimberly K.

2017-01-01

Enterocytes, the absorptive cells of the small intestine, mediate efficient absorption of dietary fat (triacylglycerol, TAG). The digestive products of dietary fat are taken up by enterocytes, re-esterified into TAG, and packaged on chylomicrons (CMs) for secretion into blood or temporarily stored within cytoplasmic lipid droplets (CLDs). Altered enterocyte TAG distribution impacts susceptibility to high fat diet associated diseases, but molecular mechanisms directing TAG toward these fates are unclear. Two enzymes, acyl CoA: diacylglycerol acyltransferase 1 (Dgat1) and Dgat2, catalyze the final, committed step of TAG synthesis within enterocytes. Mice with intestine-specific overexpression of Dgat1 (Dgat1Int) or Dgat2 (Dgat2Int), or lack of Dgat1 (Dgat1−/−), were previously found to have altered intestinal TAG secretion and storage. We hypothesized that varying intestinal Dgat1 and Dgat2 levels alters TAG distribution in subcellular pools for CM synthesis as well as the morphology and proteome of CLDs. To test this we used ultrastructural and proteomic methods to investigate intracellular TAG distribution and CLD-associated proteins in enterocytes from Dgat1Int, Dgat2Int, and Dgat1−/− mice 2 hours after a 200 μl oral olive oil gavage. We found that varying levels of intestinal Dgat1 and Dgat2 altered TAG pools involved in CM assembly and secretion, the number or size of CLDs present in enterocytes, and the enterocyte CLD proteome. Overall, these results support a model where Dgat1 and Dgat2 function coordinately to regulate the process of dietary fat absorption by preferentially synthesizing TAG for incorporation into distinct subcellular TAG pools in enterocytes. PMID:28249764

Developmental Regulation of Diacylglycerol Acyltransferase Family Gene Expression in Tung Tree Tissues

PubMed Central

Cao, Heping; Shockey, Jay M.; Klasson, K. Thomas; Chapital, Dorselyn C.; Mason, Catherine B.; Scheffler, Brian E.

2013-01-01

Diacylglycerol acyltransferases (DGAT) catalyze the final and rate-limiting step of triacylglycerol (TAG) biosynthesis in eukaryotic organisms. DGAT genes have been identified in numerous organisms. Multiple isoforms of DGAT are present in eukaryotes. We previously cloned DGAT1 and DGAT2 genes of tung tree (Vernicia fordii), whose novel seed TAGs are useful in a wide range of industrial applications. The objective of this study was to understand the developmental regulation of DGAT family gene expression in tung tree. To this end, we first cloned a tung tree gene encoding DGAT3, a putatively soluble form of DGAT that possesses 11 completely conserved amino acid residues shared among 27 DGAT3s from 19 plant species. Unlike DGAT1 and DGAT2 subfamilies, DGAT3 is absent from animals. We then used TaqMan and SYBR Green quantitative real-time PCR, along with northern and western blotting, to study the expression patterns of the three DGAT genes in tung tree tissues. Expression results demonstrate that 1) all three isoforms of DGAT genes are expressed in developing seeds, leaves and flowers; 2) DGAT2 is the major DGAT mRNA in tung seeds, whose expression profile is well-coordinated with the oil profile in developing tung seeds; and 3) DGAT3 is the major form of DGAT mRNA in tung leaves, flowers and immature seeds prior to active tung oil biosynthesis. These results suggest that DGAT2 is probably the major TAG biosynthetic isoform in tung seeds and that DGAT3 gene likely plays a significant role in TAG metabolism in other tissues. Therefore, DGAT2 should be a primary target for tung oil engineering in transgenic organisms. PMID:24146944

Four new compounds isolated from Psoralea corylifolia and their diacylglycerol acyltransferase (DGAT) inhibitory activity.

PubMed

Lin, Xin; Li, Ban-Ban; Zhang, Le; Li, Hao-Ze; Meng, Xiao; Jiang, Yi-Yu; Lee, Hyun-Sun; Cui, Long

2018-05-14

A new bakuchiol compound Δ 11 -12-hydroxy-12-dimethyl bakuchiol (1), a new flavanone compound 2(S)-6-methoxy-7- hydroxymethylene-4'-hydroxyl-flavanone (8), and two new isoflavanone compounds 4',7-dihydroxy-3'-(6"β-hydroxy-3″,7″-dimethyl-,2″,7″-dibutenyl)-geranylisoflavone (9) and 4',7-dihydroxy-3'-(7″-hydroxy-7″-methyl-2″,5″-dibutenyl)-geranylisoflavone (10) together with eight known compounds (2-7, 11, 12) were isolated from the P. corylifolia. Their structures were elucidated on the basis of spectroscopic and physico-chemical analyses. All the isolates were evaluated for in vitro inhibitory activity against DGAT1/2. Among them, compounds 3, 9 and 10 were found to exhibit selective inhibitory activity on DGAT1 with IC 50 values ranging from 93.7 ± 1.3 to 96.2 ± 1.1 μM. Compound 1 showed inhibition activity on DGAT1 with IC 50 values 73.4 ± 1.3 μM and inhibition of DGAT2 with IC 50 value 121.1 ± 1.3 μM. Copyright © 2018 Elsevier B.V. All rights reserved.

Activities of acyl-CoA:diacylglycerol acyltransferase (DGAT) and phospholipid:diacylglycerol acyltransferase (PDAT) in microsomal preparations of developing sunflower and safflower seeds.

PubMed

Banaś, Walentyna; Sanchez Garcia, Alicia; Banaś, Antoni; Stymne, Sten

2013-06-01

The last step in triacylglycerols (TAG) biosynthesis in oil seeds, the acylation of diacylglycerols (DAG), is catalysed by two types of enzymes: the acyl-CoA:diacylglycerol acyltransferase (DGAT) and phospholipid:diacylglycerol acyltransferase (PDAT). The relative contribution of these enzymes in the synthesis of TAG has not yet been defined in any plant tissue. In the presented work, microsomal preparations were obtained from sunflower and safflower seeds at different stages of development and used in DGAT and PDAT enzyme assays. The ratio between PDAT and DGAT activity differed dramatically between the two different species. DGAT activities were measured with two different acyl acceptors and assay methods using two different acyl-CoAs, and in all cases the ratio of PDAT to DGAT activity was significantly higher in safflower than sunflower. The sunflower DGAT, measured by both methods, showed significant higher activity with 18:2-CoA than with 18:1-CoA, whereas the opposite specificity was seen with the safflower enzyme. The specificities of PDAT on the other hand, were similar in both species with 18:2-phosphatidylcholine being a better acyl donor than 18:1-PC and with acyl groups at the sn-2 position utilised about fourfold the rate of the sn-1 position. No DAG:DAG transacylase activity could be detected in the microsomal preparations.

Defining the key pharmacophore elements of PF-04620110: discovery of a potent, orally-active, neutral DGAT-1 inhibitor.

PubMed

Dow, Robert L; Andrews, Melissa P; Li, Jian-Cheng; Michael Gibbs, E; Guzman-Perez, Angel; Laperle, Jennifer L; Li, Qifang; Mather, Dawn; Munchhof, Michael J; Niosi, Mark; Patel, Leena; Perreault, Christian; Tapley, Susan; Zavadoski, William J

2013-09-01

DGAT-1 is an enzyme that catalyzes the final step in triglyceride synthesis. mRNA knockout experiments in rodent models suggest that inhibitors of this enzyme could be of value in the treatment of obesity and type II diabetes. The carboxylic acid-based DGAT-1 inhibitor 1 was advanced to clinical trials for the treatment of type 2 diabetes, despite of the low passive permeability of 1. Because of questions relating to the potential attenuation of distribution and efficacy of a poorly permeable agent, efforts were initiated to identify compounds with improved permeability. Replacement of the acid moiety in 1 with an oxadiazole led to the discovery of 52, which possesses substantially improved passive permeability. The resulting pharmacodynamic profile of this neutral DGAT-1 inhibitor was found to be similar to 1 at comparable plasma exposures. Copyright © 2013 Elsevier Ltd. All rights reserved.

Comparative genomics and proteomics of vertebrate diacylglycerol acyltransferase (DGAT), acyl CoA wax alcohol acyltransferase (AWAT) and monoacylglycerol acyltransferase (MGAT).

PubMed

Holmes, Roger S

2010-03-01

BLAT (BLAST-Like Alignment Tool) analyses of the opossum (Monodelphis domestica) and zebrafish (Danio rerio) genomes were undertaken using amino acid sequences of the acylglycerol acyltransferase (AGAT) superfamily. Evidence is reported for 8 opossum monoacylglycerol acyltransferase-like (MGAT) (E.C. 2.3.1.22) and diacylglycerol acyltransferase-like (DGAT) (E.C. 2.3.1.20) genes and proteins, including DGAT1, DGAT2, DGAT2L6 (DGAT2-like protein 6), AWAT1 (acyl CoA wax alcohol acyltransferase 1), AWAT2, MGAT1, MGAT2 and MGAT3. Three of these genes (AWAT1, AWAT2 and DGAT2L6) are closely localized on the opossum X chromosome. Evidence is also reported for six zebrafish MGAT- and DGAT-like genes, including two DGAT1-like genes, as well as DGAT2-, MGAT1-, MGAT2- and MGAT3-like genes and proteins. Predicted primary, secondary and transmembrane structures for the opossum and zebrafish MGAT-, AWAT- and DGAT-like subunits and the intron-exon boundaries for genes encoding these enzymes showed a high degree of similarity with other members of the AGAT superfamily, which play major roles in triacylglyceride (DGAT), diacylglyceride (MGAT) and wax ester (AWAT) biosynthesis. Alignments of predicted opossum, zebrafish and other vertebrate DGAT1, DGAT2, other DGAT2-like and MGAT-like amino acid sequences with known human and mouse enzymes demonstrated conservation of residues which are likely to play key roles in catalysis, lipid binding or in maintaining structure. Phylogeny studies of the human, mouse, opossum, zebrafish and pufferfish MGAT- and DGAT-like enzymes indicated that the common ancestors for these genes predated the appearance of bony fish during vertebrate evolution whereas the AWAT- and DGAT2L6-like genes may have appeared more recently prior to the appearance of marsupial and eutherian mammals. Copyright 2009 Elsevier Inc. All rights reserved.

Inactivation of human DGAT2 by oxidative stress on cysteine residues

PubMed Central

Choi, Kwangman; Kwon, Eun Bin; Kang, Mingu; Kim, Dong-eun; Jeong, Hyejeong; Kim, Janghwan; Kim, Jong Heon; Kim, Mun Ock; Han, Sang-Bae

2017-01-01

Diacylglycerol acyltransferases (DGATs) have a crucial role in the biosynthesis of triacylglycerol (TG), the major storage form of metabolic energy in eukaryotic organisms. Even though DGAT2, one of two distinct DGATs, has a vital role in TG biosynthesis, little is known about the regulation of DGAT2 activity. In this study, we examined the role of cysteine and its oxidation in the enzymatic activity of human DGAT2 in vitro. Human DGAT2 activity was considerably inhibited not only by thiol-modifying reagents (NEM and IA) but also by ROS-related chemicals (H2O2 and β-lapachone), while human DGAT1 and GPAT1 were little affected. Particularly, ROS-related chemicals concomitantly induced intermolecular disulfide crosslinking of human DGAT2. Both the oxidative inactivation and disulfide crosslinking were almost completely reversed by the treatment with DTT, a disulfide-reducing agent. These results clearly demonstrated the significant role of ROS-induced intermolecular crosslinking in the inactivation of human DGAT2 and also suggested DGAT2 as a redox-sensitive regulator in TG biosynthesis. PMID:28700690

DGAT inhibitors for obesity.

PubMed

Matsuda, Daisuke; Tomoda, Hiroshi

2007-10-01

Obesity is characterized by the accumulation of triacylglycerol in adipocytes. Diacylglycerol acyltransferase (DGAT) catalyzes the final reaction of triacylgycerol synthesis. Two isozymes of DGAT, DGAT1 and DGAT2, have been reported. Increased DGAT2 activity has a role in steatosis, while DGAT1 plays a role in very (V)LDL synthesis; increased plasma VLDL concentrations may promote obesity and thus DGAT1 is considered a potential therapeutic target of inhibition for obesity control. Several DGAT inhibitors of natural and synthetic origin have been reported, and their future prospect as anti-obesity drugs is discussed in this review.

Regulation of diacylglycerol acyltransferase 2 protein stability by gp78-associated endoplasmic-reticulum-associated degradation.

PubMed

Choi, Kwangman; Kim, Hyeongki; Kang, Hyunju; Lee, So-Young; Lee, Sang Jun; Back, Sung Hoon; Lee, Seo Hyun; Kim, M Sun; Lee, Jeong Eun; Park, Ju Young; Kim, Jiye; Kim, Sunhong; Song, Jae-Hyung; Choi, Yura; Lee, Suui; Lee, Hyun-Jun; Kim, Jong Heon; Cho, Sungchan

2014-07-01

Triacylglycerol (TG) is the major form of stored energy in eukaryotic organisms and is synthesized by diacylglycerol acyltransferase (DGAT) in the endoplasmic reticulum (ER). DGAT2, one of the two DGAT enzymes, is barely detectable in cells, even though its mRNA transcripts are maintained at considerable levels. However, little is known about how DGAT2 expression is altered by protein stability. DGAT2 was highly unstable in cells and was rapidly degraded by proteasomes in an ubiquitin-dependent manner. Deletion mutation analysis identified transmembrane domain 1 (TMD1) as a protein degradation signal. TMD1 is also important for ER localization of DGAT2. Moreover, DGAT2 interacted with p97/VCP, a crucial component of the ER-associated degradation (ERAD) pathway, and polyubiquitinated DGAT2 accumulated following treatment with an ERAD inhibitor. Furthermore, gp78, an E3 ligase involved in ERAD, regulates the degradation of DGAT2 through direct interactions and ubiquitination. Consequently, the stabilization of DGAT2 increased the number of lipid droplets in hepatic cells. Therefore, DGAT2 is regulated by gp78-associated ERAD at the post-translational level. © 2014 FEBS.

Dictyostelium discoideum Dgat2 Can Substitute for the Essential Function of Dgat1 in Triglyceride Production but Not in Ether Lipid Synthesis

PubMed Central

Du, Xiaoli; Herrfurth, Cornelia; Gottlieb, Thomas; Kawelke, Steffen; Feussner, Kristin; Rühling, Harald; Feussner, Ivo

2014-01-01

Triacylglycerol (TAG), the common energy storage molecule, is formed from diacylglycerol and a coenzyme A-activated fatty acid by the action of an acyl coenzyme A:diacylglycerol acyltransferase (DGAT). In order to conduct this step, most organisms rely on more than one enzyme. The two main candidates in Dictyostelium discoideum are Dgat1 and Dgat2. We show, by creating single and double knockout mutants, that the endoplasmic reticulum (ER)-localized Dgat1 enzyme provides the predominant activity, whereas the lipid droplet constituent Dgat2 contributes less activity. This situation may be opposite from what is seen in mammalian cells. Dictyostelium Dgat2 is specialized for the synthesis of TAG, as is the mammalian enzyme. In contrast, mammalian DGAT1 is more promiscuous regarding its substrates, producing diacylglycerol, retinyl esters, and waxes in addition to TAG. The Dictyostelium Dgat1, however, produces TAG, wax esters, and, most interestingly, also neutral ether lipids, which represent a significant constituent of lipid droplets. Ether lipids had also been found in mammalian lipid droplets, but the role of DGAT1 in their synthesis was unknown. The ability to form TAG through either Dgat1 or Dgat2 activity is essential for Dictyostelium to grow on bacteria, its natural food substrate. PMID:24562909

Valproate induced hepatic steatosis by enhanced fatty acid uptake and triglyceride synthesis.

PubMed

Bai, Xupeng; Hong, Weipeng; Cai, Peiheng; Chen, Yibei; Xu, Chuncao; Cao, Di; Yu, Weibang; Zhao, Zhongxiang; Huang, Min; Jin, Jing

2017-06-01

Steatosis is the characteristic type of VPA-induced hepatotoxicity and may result in life-threatening hepatic lesion. Approximately 61% of patients treated with VPA have been diagnosed with hepatic steatosis through ultrasound examination. However, the mechanisms underlying VPA-induced intracellular fat accumulation are not yet fully understood. Here we demonstrated the involvement of fatty acid uptake and lipogenesis in VPA-induced hepatic steatosis in vitro and in vivo by using quantitative real-time PCR (qRT-PCR) analysis, western blotting analysis, fatty acid uptake assays, Nile Red staining assays, and Oil Red O staining assays. Specifically, we found that the expression of cluster of differentiation 36 (CD36), an important fatty acid transport, and diacylglycerol acyltransferase 2 (DGAT2) were significantly up-regulated in HepG2 cells and livers of C57B/6J mice after treatment with VPA. Furthermore, VPA treatment remarkably enhanced the efficiency of fatty acid uptake mediated by CD36, while this effect was abolished by the interference with CD36-specific siRNA. Also, VPA treatment significantly increased DGAT2 expression as a result of the inhibition of mitogen-activated protein kinase kinase (MEK) - extracellular regulated kinase (ERK) pathway; however, DGAT2 knockdown significantly alleviated VPA-induced intracellular lipid accumulation. Additionally, we also found that sterol regulatory element binding protein-1c (SREBP-1c)-mediated fatty acid synthesis may be not involved in VPA-induced hepatic steatosis. Overall, VPA-triggered over-regulation of CD36 and DGAT2 could be helpful for a better understanding of the mechanisms underlying VPA-induced hepatic steatosis and may offer novel therapeutic strategies to combat VPA-induced hepatotoxicity. Copyright © 2017 Elsevier Inc. All rights reserved.

The Role of Diacylglycerol Acyltransferase (DGAT) 1 and 2 in Cardiac Metabolism and Function.

PubMed

Roe, Nathan D; Handzlik, Michal K; Li, Tao; Tian, Rong

2018-03-21

It is increasingly recognized that synthesis and turnover of cardiac triglyceride (TG) play a pivotal role in the regulation of lipid metabolism and function of the heart. The last step in TG synthesis is catalyzed by diacylglycerol:acyltransferase (DGAT) which esterifies the diacylglycerol with a fatty acid. Mammalian heart has two DGAT isoforms, DGAT1 and DGAT2, yet their roles in cardiac metabolism and function remain poorly defined. Here, we show that inactivation of DGAT1 or DGAT2 in adult mouse heart results in a moderate suppression of TG synthesis and turnover. Partial inhibition of DGAT activity increases cardiac fatty acid oxidation without affecting PPARα signaling, myocardial energetics or contractile function. Moreover, coinhibition of DGAT1/2 in the heart abrogates TG turnover and protects the heart against high fat diet-induced lipid accumulation with no adverse effects on basal or dobutamine-stimulated cardiac function. Thus, the two DGAT isoforms in the heart have partially redundant function, and pharmacological inhibition of one DGAT isoform is well tolerated in adult hearts.

Improvement of mTORC1-driven overproduction of apoB-containing triacylglyceride-rich lipoproteins by short-chain fatty acids, 4-phenylbutyric acid and (R)-α-lipoic acid, in human hepatocellular carcinoma cells.

PubMed

Roberts, Joseph L; He, Bo; Erickson, Anjeza; Moreau, Régis

2016-03-01

The activation of hepatic kinase mechanistic target of rapamycin complex 1 (mTORC1) is implicated in the development of obesity-related metabolic disorders. This study investigated the metabolic sequelae of mTORC1 hyperactivation in human hepatoma cells and the lipid-regulating mechanisms of two short-chain fatty acids: 4-phenylbutyric acid (PBA) and (R)-α-lipoic acid (LA). We created three stable cell lines that exhibit low, normal, or high mTORC1 activity. mTORC1 hyperactivation induced the expression of lipogenic (DGAT1 and DGAT2) and lipoprotein assembly (MTP and APOB) genes, thereby raising cellular triacylglyceride (TG) and exacerbating secretion of apoB-containing TG-rich lipoproteins. LYS6K2, a specific inhibitor of the p70 S6 kinase branch of mTORC1 signaling, reversed these effects. PBA and LA decreased secreted TG through distinct mechanisms. PBA repressed apoB expression (both mRNA and protein) and lowered secreted TG without mitigation of mTORC1 hyperactivity or activation of AMPK. LA decreased cellular and secreted TG by attenuating mTORC1 signaling in an AMPK-independent manner. LA did not regulate apoB expression but led to the secretion of apoB-containing TG-poor lipoproteins by repressing the expression of lipogenic genes, FASN, DGAT1, and DGAT2. Our studies provide new mechanistic insight into the hypolipidemic activity of PBA and LA in the context of mTORC1 hyperactivation and suggest that the short-chain fatty acids may aid in the prevention and treatment of hypertriglyceridemia. Copyright © 2015 Elsevier B.V. All rights reserved.

[Progress in the study on diacylgycerol acyltransferase (DGAT)-related genes].

PubMed

Ma, Hai-Ming; Shi, Qi-Shun; Liu, Xiao-Chun

2005-12-01

Diacylgycerol Acyltransferase (DGAT) plays an important role in the formation of lipid in different tissues of biological body. DGAT catalyzes the final step in triacylglycerol (TAG) biosynthesis by converting diacylgycerol (DAG) and fatty acyl-coenzyme A (CoA) into triacylglycerol. This enzyme is coded by both DGAT1 and DGAT2. DGAT1 belongs to the gene family of cholesterol acyltransferase (ACAT). DGAT2 belongs to the gene family of monoacylgycerol acyltransferases (MGAT1). This paper reviewed the structure, location on chromosome and biological effect of DGAT-related genes. The relationship between polymorphism and performance of animal was also discussed.

DGAT: novel therapeutic target for obesity and type 2 diabetes mellitus.

PubMed

Subauste, Angela; Burant, Charles F

2003-12-01

Obesity is currently an exceptionally common problem in humans. The last several years have produced a significant number of breakthroughs in obesity related areas of investigation. Triglycerides are considered the main form of storage of excess calories in fat. A key enzyme in the synthesis of triglycerides is acylCoA: diacylglycerol acyltransferase (DGAT). Recent studies have shown that mice deficient in this enzyme are resistant to diet induced obesity and have increased insulin and leptin sensitivity. These effects suggest that inhibition of DGAT in vivo may be a novel therapeutic target not only for obesity but also for diabetes.

Concerted elevation of acyl-coenzyme A:diacylglycerol acyltransferase (DGAT) activity through independent stimulation of mRNA expression of DGAT1 and DGAT2 by carbohydrate and insulin.

PubMed

Meegalla, Rupalie L; Billheimer, Jeffrey T; Cheng, Dong

2002-11-01

Glucose and insulin are anabolic signals which upregulate the transcriptions of a series of lipogenic enzymes to convert excess carbohydrate into triglycerides for efficient energy storage. These enzymes include ATP-citrate lyase (ACL), acetyl-coenzyme A carboxylase (ACC), fatty acid synthase (FAS), and glycerol-3-phosphate acyltransferase (G3PA). Acyl-coenzyme A:diacylglycerol acyltransferase (DGAT) is important to synthesize fatty acids into triglycerides. Two DGATs from different gene families have recently been identified. In the current study, we report that glucose preferentially enhances DGAT1 mRNA expression, whereas insulin specifically increases the level of DGAT2 mRNA. Treatment of adipocytes with glucose and insulin together results in higher DGAT activity in the membrane than cells treated with either of the agents alone, indicating that glucose and insulin have additive effect on DGAT activation. In mice treated with fast/refeeding protocol, DGAT2 mRNA decreased upon fasting and was replenished upon refeeding in adipose tissue and liver. This pattern of change was not observed for DGAT1. Inasmuch as DGAT1 mRNA is less abundant in liver, we suggest that DGAT1 is more involved in fat absorption in the intestine and in basal level triglyceride synthesis in adipose tissue where it is more highly expressed. In contrast, DGAT2 is more likely to play important roles in assembly of de novo synthesized fatty acids into VLDL particles in the liver.

BnDGAT1s Function Similarly in Oil Deposition and Are Expressed with Uniform Patterns in Tissues of Brassica napus.

PubMed

Zhao, Cuizhu; Li, Huan; Zhang, Wenxue; Wang, Hailan; Xu, Aixia; Tian, Jianhua; Zou, Jitao; Taylor, David C; Zhang, Meng

2017-01-01

As an allotetraploid oilcrop, Brassica napus contains four duplicated Acyl-CoA:diacylglycerol acyltransferase 1 ( DGAT1 ) genes, which catalyze one of the rate-limiting steps in triacylglycerol (TAG) biosynthesis in plants. While all four BnDGAT1 s have been expressed functionally in yeast, their expression patterns in different germplasms and tissues and also consequent contribution to seed oil accumulation in planta remain to be elucidated. In this study, the coding regions of the four BnDGAT1s were expressed in an Arabidopsis dgat1 mutant. All four BnDGAT1s showed similar effects on oil content and fatty acid composition, a result which is different from that observed in previous studies of their expression in yeast. Expression patterns of BnDGAT1s were analyzed in developing seeds of 34 B. napus inbred lines and in different tissues of 14 lines. Different expression patterns were observed for the four BnDGAT1 s, which suggests that they express independently or randomly in different germplasm sources. Higher expression of BnDGAT1s was correlated with higher seed oil content lines. Tissue-specific analyses showed that the BnDGAT1 s were expressed in a uniform pattern in different tissues. Our results suggest that it is important to maintain expression of the four BnDGAT1s for maximum return on oil content.

Valproate induced hepatic steatosis by enhanced fatty acid uptake and triglyceride synthesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bai, Xupeng; Hong, Weipeng; Cai, Peiheng

Steatosis is the characteristic type of VPA-induced hepatotoxicity and may result in life-threatening hepatic lesion. Approximately 61% of patients treated with VPA have been diagnosed with hepatic steatosis through ultrasound examination. However, the mechanisms underlying VPA-induced intracellular fat accumulation are not yet fully understood. Here we demonstrated the involvement of fatty acid uptake and lipogenesis in VPA-induced hepatic steatosis in vitro and in vivo by using quantitative real-time PCR (qRT-PCR) analysis, western blotting analysis, fatty acid uptake assays, Nile Red staining assays, and Oil Red O staining assays. Specifically, we found that the expression of cluster of differentiation 36 (CD36),more » an important fatty acid transport, and diacylglycerol acyltransferase 2 (DGAT2) were significantly up-regulated in HepG2 cells and livers of C57B/6J mice after treatment with VPA. Furthermore, VPA treatment remarkably enhanced the efficiency of fatty acid uptake mediated by CD36, while this effect was abolished by the interference with CD36-specific siRNA. Also, VPA treatment significantly increased DGAT2 expression as a result of the inhibition of mitogen-activated protein kinase kinase (MEK) – extracellular regulated kinase (ERK) pathway; however, DGAT2 knockdown significantly alleviated VPA-induced intracellular lipid accumulation. Additionally, we also found that sterol regulatory element binding protein-1c (SREBP-1c)-mediated fatty acid synthesis may be not involved in VPA-induced hepatic steatosis. Overall, VPA-triggered over-regulation of CD36 and DGAT2 could be helpful for a better understanding of the mechanisms underlying VPA-induced hepatic steatosis and may offer novel therapeutic strategies to combat VPA-induced hepatotoxicity. - Highlights: • VPA induced hepatic steatosis and modulated genes associated with lipid metabolism. • CD36-mediated fatty acid uptake contributed to VPA-induced lipid accumulation. • PA increased the hepatic level of DGAT2 through inhibiting MEK-ERK pathway and enhanced triglyceride synthesis. • SREBP-1c-mediated fatty acid synthesis was not involved in VPA-induced hepatic steatosis.« less

Characterization of acyl-coenzyme A:diacylglycerol acyltransferase (DGAT) enzyme of human small intestine.

PubMed

Hiramine, Yasushi; Tanabe, Toshizumi

2011-06-01

Acyl-coenzyme A:diacylglycerol acyltransferase (DGAT) enzyme plays a significant role in dietary triacylglycerol (TAG) absorption in the small intestine. However, the characteristics of human intestinal DGAT enzyme have not been examined in detail. The aim of our study was to characterize the human intestinal DGAT enzyme by examining acyl-CoA specificity, temperature dependency, and selectivity for 1,2-diacylglycerol (DAG) or 1,3-DAG. We detected DGAT activity of human intestinal microsome and found that the acyl-CoA specificity and temperature dependency of intestinal DGAT coincided with those of recombinant human DGAT1. To elucidate the selectivity of human intestinal DGAT to 1,2-DAG or 1,3-DAG, we conducted acyl-coenzyme A:monoacylglycerol acyltransferase assays using 1- or 2-monoacylglycerol (MAG) as substrates. When 2-MAG was used as acyl acceptor, both 1,2-DAG and TAG were generated; however, when 1-MAG was used, 1,3-DAG was predominantly observed and little TAG was detected. These findings suggest that human small intestinal DGAT, which is mainly encoded by DGAT1, utilizes 1,2-DAG as the substrate to form TAG. This study will contribute to understand the lipid absorption profile in the small intestine.

Discovery of PF-04620110, a Potent, Selective, and Orally Bioavailable Inhibitor of DGAT-1

PubMed Central

2011-01-01

Acyl-CoA:diacylglycerol acyltransferase-1 (DGAT-1) catalyzes the final committed step in the biosynthesis of triglycerides. DGAT-1 knockout mice have been shown to be resistant to diet-induced obesity and have increased insulin sensitivity. Thus, inhibition of DGAT-1 may represent an attractive target for the treatment of obesity or type II diabetes. Herein, we report the discovery and characterization of a potent and selective DGAT-1 inhibitor PF-04620110 (3). Compound 3 inhibits DGAT-1 with an IC50 of 19 nM and shows high selectivity versus a broad panel of off-target pharmacologic end points. In vivo DGAT-1 inhibition has been demonstrated through reduction of plasma triglyceride levels in rodents at doses of ≥0.1 mg/kg following a lipid challenge. On the basis of this pharmacologic and pharmacokinetic profile, compound 3 has been advanced to human clinical studies. PMID:24900321

Discovery of PF-04620110, a Potent, Selective, and Orally Bioavailable Inhibitor of DGAT-1.

PubMed

Dow, Robert L; Li, Jian-Cheng; Pence, Michael P; Gibbs, E Michael; LaPerle, Jennifer L; Litchfield, John; Piotrowski, David W; Munchhof, Michael J; Manion, Tara B; Zavadoski, William J; Walker, Gregory S; McPherson, R Kirk; Tapley, Susan; Sugarman, Eliot; Guzman-Perez, Angel; DaSilva-Jardine, Paul

2011-05-12

Acyl-CoA:diacylglycerol acyltransferase-1 (DGAT-1) catalyzes the final committed step in the biosynthesis of triglycerides. DGAT-1 knockout mice have been shown to be resistant to diet-induced obesity and have increased insulin sensitivity. Thus, inhibition of DGAT-1 may represent an attractive target for the treatment of obesity or type II diabetes. Herein, we report the discovery and characterization of a potent and selective DGAT-1 inhibitor PF-04620110 (3). Compound 3 inhibits DGAT-1 with an IC50 of 19 nM and shows high selectivity versus a broad panel of off-target pharmacologic end points. In vivo DGAT-1 inhibition has been demonstrated through reduction of plasma triglyceride levels in rodents at doses of ≥0.1 mg/kg following a lipid challenge. On the basis of this pharmacologic and pharmacokinetic profile, compound 3 has been advanced to human clinical studies.

Castor diacylglycerol acyltransferase type1(DGAT1)displays greater activity with diricinolein than Arabidopsis DGAT1

USDA-ARS?s Scientific Manuscript database

Castor oil contains the hydroxy fatty acid ricinoleate as a major (90%) component. The diacylglycerol acyltransferase (DGAT) carries out the final reaction step in the biosynthesis of triacylglycerol, the principal constituent of seed oil, and has been considered to be the step that controls the oil...

BnDGAT1s Function Similarly in Oil Deposition and Are Expressed with Uniform Patterns in Tissues of Brassica napus

PubMed Central

Zhao, Cuizhu; Li, Huan; Zhang, Wenxue; Wang, Hailan; Xu, Aixia; Tian, Jianhua; Zou, Jitao; Taylor, David C.; Zhang, Meng

2017-01-01

As an allotetraploid oilcrop, Brassica napus contains four duplicated Acyl-CoA:diacylglycerol acyltransferase 1 (DGAT1) genes, which catalyze one of the rate-limiting steps in triacylglycerol (TAG) biosynthesis in plants. While all four BnDGAT1s have been expressed functionally in yeast, their expression patterns in different germplasms and tissues and also consequent contribution to seed oil accumulation in planta remain to be elucidated. In this study, the coding regions of the four BnDGAT1s were expressed in an Arabidopsis dgat1 mutant. All four BnDGAT1s showed similar effects on oil content and fatty acid composition, a result which is different from that observed in previous studies of their expression in yeast. Expression patterns of BnDGAT1s were analyzed in developing seeds of 34 B. napus inbred lines and in different tissues of 14 lines. Different expression patterns were observed for the four BnDGAT1s, which suggests that they express independently or randomly in different germplasm sources. Higher expression of BnDGAT1s was correlated with higher seed oil content lines. Tissue-specific analyses showed that the BnDGAT1s were expressed in a uniform pattern in different tissues. Our results suggest that it is important to maintain expression of the four BnDGAT1s for maximum return on oil content. PMID:29312429

Up-regulation of hepatic Acyl CoA: Diacylglycerol acyltransferase-1 (DGAT-1) expression in nephrotic syndrome.

PubMed

Vaziri, Nosratola D; Kim, Choong H; Phan, Dennis; Kim, Sara; Liang, Kaihui

2004-07-01

Nephrotic syndrome is associated with hypercholesterolemia, hypertriglyceridemia, and marked elevations of plasma low-density lipoprotein (LDL) and very low-density lipoprotein (VLDL). Hypertriglyceridemia in nephrotic syndrome is accompanied by increased hepatic fatty acid synthesis, elevated triglyceride secretion, as well as lipoprotein lipase, VLDL-receptor, and hepatic triglyceride lipase deficiencies, which lead to impaired clearance of triglyceride-rich lipoproteins. Acyl CoA: diacylglycerol acyltransferase (DGAT) is a microsomal enzyme that joins acyl CoA to 1, 2-diacylglycerol to form triglyceride. Two distinct DGATs (DGAT-1 and DGAT2) have recently been identified in the liver and other tissues. The present study tested the hypothesis that the reported increase in hepatic triglyceride secretion in nephrotic syndrome may be caused by up-regulation of DGAT. Male Sprague-Dawley rats were rendered nephrotic by two sequential injections of puromycin aminonucleoside (130 mg/kg on day 1 and 60 mg/kg on day 14) and studied on day 30. Placebo-treated rats served as controls. Hepatic DGAT-1 and DGAT-2 mRNA abundance and enzymatic activity were measured. The nephrotic group exhibited heavy proteinuria, hypoalbuminemia, hypercholesterolemia, hypertriglyceridemia, and marked elevation of VLDL concentration. Hepatic DGAT-1 mRNA, DGAT-1, and total DGAT activity were significantly increased, whereas DGAT-2 mRNA abundance and activity were unchanged in the nephrotic rats compared to the control animals. The functional significance of elevation of DGAT activity was illustrated by the reduction in microsomal free fatty acid concentration in the liver of nephrotic animals. Nephrotic syndrome results in up-regulation of hepatic DGAT-1 expression and activity, which can potentially contribute to the associated hypertriglyceridemia by enhancing triglyceride synthesis. Thus, it appears that both depressed catabolism and increased synthetic capacity contribute to hypertriglyceridemia of nephrotic syndrome.

Sequence analysis of diacylglycerol acyltransferases

USDA-ARS?s Scientific Manuscript database

Diacylglycerol acyltransferases (DGATs) catalyze the final step of triacylglycerol (TAG) biosynthesis in eukaryotes. DGATs esterify sn-1,2-diacylglycerol with a long-chain fatty acyl-CoA. Plants and animals deficient in DGATs accumulate less TAG and over-expression of DGATs increases TAG. DGAT knock...

Developmental regulation of diacylglycerol acyltransferase family gene expression in tung tree tissues

USDA-ARS?s Scientific Manuscript database

Diacylglycerol acyltransferases (DGAT) are responsible for the final and rate-limiting step of triacylglycerol (TAG) biosynthesis in eukaryotic organisms. DGAT genes have been identified in numerous organisms. Multiple isoforms of DGAT are present in eukaryotes, including DGAT1 and DGAT2 of tung tre...

Four new sesqui-lignans isolated from Acanthopanax senticosus and their diacylglycerol acyltransferase (DGAT) inhibitory activity.

PubMed

Li, Jia-Lin; Li, Na; Lee, Hyun-Sun; Xing, Shan-Shan; Qi, Shi-Zhou; Tuo, Zhen-Dong; Zhang, Le; Li, Ban-Ban; Chen, Jian-Guang; Cui, Long

2016-03-01

Four new sesqui-lignans, (7R, 7'R, 7″S, 8S, 8'S, 8″S)-4',5″-dihydroxy-3,5,3',4″-tetramethoxy-7,9':7',9-diepoxy-4,8″-oxy-8,8'-sesquineo-lignan-7″,9″-diol (1), (7R, 7'R, 7″S, 8S, 8'S, 8″S)-4',3″-dihydroxy-3,5,3',5',4″-pentamethoxy-7,9':7',9-diepoxy-4,8″-oxy-8,8'-sesquineo-lignan-7″,9″-diol (2), (7R, 7'R, 7″S, 8S, 8'S, 8″S)-3',4″-dihydroxy-3,5,4',5″-tetramethoxy-7,9':7',9-diepoxy-4,8″-oxy-8,8'-sesquineo-lignan-7″,9″-diol (3) and acanthopanax A (7) together with three known compounds (4-6) were isolated from the EtOAc-soluble extract of Acanthopanax senticosus. Their structures were elucidated on the basis of spectroscopic and physicochemical analyses. All the isolates were evaluated for in vitro inhibitory activity against DGAT1 and DGAT2. Among them, compounds 1-6 were found to exhibit selective inhibitory activity on DGAT1 with IC50 values ranging from 61.1 ± 1.3 to 97.7 ± 1.1 μM and compound 7 showed selective inhibition of DGAT2 with IC50 value 93.2 ± 1.2. Copyright © 2016 Elsevier B.V. All rights reserved.

Effect of CLA and other C18 unsaturated fatty acids on DGAT in bovine milk fat biosynthetic systems.

PubMed

Sørensen, Brent M; Chris Kazala, E; Murdoch, Gordon K; Keating, Aileen F; Cruz-Hernandez, Cristina; Wegner, Jochen; Kennelly, John J; Okine, Erasmus K; Weselake, Randall J

2008-10-01

Production of dairy products with increased amounts of nutraceutic FA such as conjugated linoleic acid (CLA) represents a recent approach for dairy producers and processors to increase the value of their products. The effect of CLA and other FA on the expression of diacylglycerol acyltransferase-1 (DGAT-1) and DGAT-2, and DGAT activity were investigated in bovine mammary gland epithelial (MAC-T) cells. DGAT gene expression analyses were also conducted using bovine mammary gland tissue from dairy cows. In the studies with MAC-T cells, there were no significant effects of CLA isomers or other FA on DGAT1 expression, whereas all FA tested showed enhanced DGAT2 expression (P < 0.05 to P < 0.001), with alpha-linolenic acid (alpha-18:3) having the greatest effect. Additionally, DGAT2 expression was co-ordinated with expression of lysophosphatidic acid acyltransferase (LPAAT), an observation that was also apparent in mammary gland from lactating dairy cows. In contrast, treatment of MAC-T cells with trans-10, cis-12 18:2 or alpha-18:3 resulted in a significant (P < 0.05) decrease in overall DGAT enzyme activity, although the mechanisms resulting in these effects are unclear. Competition assays using microsomes from bovine mammary gland tissue and 1-[(14)C]oleoyl-CoA suggested that DGAT activity was more selective for oleoyl (cis-9 18:1)-CoA than cis-9, trans-11 18:2-, trans-10, cis-12 18:2- or cis-9, cis-12 18:2-CoA. Collectively, the results suggest the relationship between trans-10, cis-12 18:2 and reduced TAG production in bovine milk is not linked to the production of DGAT1 or DGAT2 transcripts, but probably involves effects of this CLA isomer at events beyond transcription, such as post-translational and/or enzyme activity effects.

A novel assay of DGAT activity based on high temperature GC/MS of triacylglycerol.

PubMed

Greer, Michael S; Zhou, Ting; Weselake, Randall J

2014-08-01

Diacylglycerol acyltransferase (DGAT) catalyzes the final step in the acyl-CoA-dependent biosynthesis of triacylglycerol (TAG), a high-energy compound composed of three fatty acids esterified to a glycerol backbone. In vitro DGAT assays, which are usually conducted with radiolabeled substrate using microsomal fractions, have been useful in identifying compounds and genetic modifications that affect DGAT activity. Here, we describe a high-temperature gas chromatography (GC)/mass spectrometry (MS)-based method for monitoring molecular species of TAG produced by the catalytic action of microsomal DGAT. This method circumvents the need for radiolabeled or modified substrates, and only requires a simple lipid extraction prior to GC. The utility of the method is demonstrated using a recombinant type-1 Brassica napus DGAT produced in a strain of Saccharomyces cerevisae that is deficient in TAG synthesis. The GC/MS-based assay of DGAT activity was strongly correlated with the typical in vitro assay of the enzyme using [1-(14)C] acyl-CoA as an acyl donor. In addition to determining DGAT activity, the method is also useful for determining substrate specificity and selectivity properties of the enzyme.

Modeling the Mechanism of Action of a DGAT1 Inhibitor Using a Causal Reasoning Platform

PubMed Central

Enayetallah, Ahmed E.; Ziemek, Daniel; Leininger, Michael T.; Randhawa, Ranjit; Yang, Jianxin; Manion, Tara B.; Mather, Dawn E.; Zavadoski, William J.; Kuhn, Max; Treadway, Judith L.; des Etages, Shelly Ann G.; Gibbs, E. Michael; Greene, Nigel; Steppan, Claire M.

2011-01-01

Triglyceride accumulation is associated with obesity and type 2 diabetes. Genetic disruption of diacylglycerol acyltransferase 1 (DGAT1), which catalyzes the final reaction of triglyceride synthesis, confers dramatic resistance to high-fat diet induced obesity. Hence, DGAT1 is considered a potential therapeutic target for treating obesity and related metabolic disorders. However, the molecular events shaping the mechanism of action of DGAT1 pharmacological inhibition have not been fully explored yet. Here, we investigate the metabolic molecular mechanisms induced in response to pharmacological inhibition of DGAT1 using a recently developed computational systems biology approach, the Causal Reasoning Engine (CRE). The CRE algorithm utilizes microarray transcriptomic data and causal statements derived from the biomedical literature to infer upstream molecular events driving these transcriptional changes. The inferred upstream events (also called hypotheses) are aggregated into biological models using a set of analytical tools that allow for evaluation and integration of the hypotheses in context of their supporting evidence. In comparison to gene ontology enrichment analysis which pointed to high-level changes in metabolic processes, the CRE results provide detailed molecular hypotheses to explain the measured transcriptional changes. CRE analysis of gene expression changes in high fat habituated rats treated with a potent and selective DGAT1 inhibitor demonstrate that the majority of transcriptomic changes support a metabolic network indicative of reversal of high fat diet effects that includes a number of molecular hypotheses such as PPARG, HNF4A and SREBPs. Finally, the CRE-generated molecular hypotheses from DGAT1 inhibitor treated rats were found to capture the major molecular characteristics of DGAT1 deficient mice, supporting a phenotype of decreased lipid and increased insulin sensitivity. PMID:22073239

Genetic interaction of DGAT2 and FAAH in the development of human obesity.

PubMed

Ning, Tinglu; Zou, Yaoyu; Yang, Minglan; Lu, Qianqian; Chen, Maopei; Liu, Wen; Zhao, Shaoqian; Sun, Yingkai; Shi, Juan; Ma, Qinyun; Hong, Jie; Liu, Ruixin; Wang, Jiqiu; Ning, Guang

2017-05-01

DGAT2 is the critical catalyzing enzyme for triglyceride biosynthesis, and excess triglyceride accumulation in fat tissues is a fundamental process for obesity. Mutations in DGAT2 or other genes interacting with DGAT2 associated with adiposity have not been reported in human to date. DGAT2 mutation was identified based on our in-home database-exome sequencing 227 young obese subjects (body-mass index (BMI), 35.1-61.7 kg/m 2 ) and 219 lean controls (BMI, 17.5-23.0 kg/m 2 ), further validated in 1190 lean subjects and the pedigree of the proband. The trios of the proband were further subjected to whole-exome sequencing to explore the candidate genes for obesity. The mutations in DGAT2 and FAAH were functionally evaluated in vitro. We detected two rare variants in DGAT2 with no significant difference between obese and lean individuals. One novel heterozygous nonsense variant c.382C > T (p.R128*) was identified in one obese subject but not in 219 lean subjects and another 1190 lean subjects. Notably, in vitro study showed that R128* mutation severely damaged the TG-biosynthesis ability of DGAT2, and all other R128* carriers in the pedigree were lean. Thus, we further identified a loss-of-function variant c. 944G > T (p.R315I) in FAAH in the proband inheriting from his obese father. Importantly, FAAH overexpression inhibited DGAT2 expression and TG synthesis, while R315I mutant largely eliminated this inhibitory effect. We first report loss-of-function mutations in DGAT2 and FAAH in one obese subject, which may interact with each other to affect the adiposity penetrance, providing a model of genetic interaction associated with human obesity.

Expression of Fungal diacylglycerol acyltransferase2 Genes to Increase Kernel Oil in Maize[OA

PubMed Central

Oakes, Janette; Brackenridge, Doug; Colletti, Ron; Daley, Maureen; Hawkins, Deborah J.; Xiong, Hui; Mai, Jennifer; Screen, Steve E.; Val, Dale; Lardizabal, Kathryn; Gruys, Ken; Deikman, Jill

2011-01-01

Maize (Zea mays) oil has high value but is only about 4% of the grain by weight. To increase kernel oil content, fungal diacylglycerol acyltransferase2 (DGAT2) genes from Umbelopsis (formerly Mortierella) ramanniana and Neurospora crassa were introduced into maize using an embryo-enhanced promoter. The protein encoded by the N. crassa gene was longer than that of U. ramanniana. It included 353 amino acids that aligned to the U. ramanniana DGAT2A protein and a 243-amino acid sequence at the amino terminus that was unique to the N. crassa DGAT2 protein. Two forms of N. crassa DGAT2 were tested: the predicted full-length protein (L-NcDGAT2) and a shorter form (S-NcDGAT2) that encoded just the sequences that share homology with the U. ramanniana protein. Expression of all three transgenes in maize resulted in small but statistically significant increases in kernel oil. S-NcDGAT2 had the biggest impact on kernel oil, with a 26% (relative) increase in oil in kernels of the best events (inbred). Increases in kernel oil were also obtained in both conventional and high-oil hybrids, and grain yield was not affected by expression of these fungal DGAT2 transgenes. PMID:21245192

Intestinal Failure and Aberrant Lipid Metabolism in Patients With DGAT1 Deficiency.

PubMed

van Rijn, Jorik M; Chandra Ardy, Rico; Kuloğlu, Zarife; Härter, Bettina; van Haaften-Visser, Désirée Y; van der Doef, Hubert P J; van Hoesel, Marliek; Kansu, Aydan; van Vugt, Anke H M; Ng, Marini; Kokke, Freddy T M; Krolo, Ana; Başaran, Meryem Keçeli; Kaya, Neslihan Gurcan; Aksu, Aysel Ünlüsoy; Dalgıç, Buket; Ozcay, Figen; Baris, Zeren; Kain, Renate; Stigter, Edwin C A; Lichtenbelt, Klaske D; Massink, Maarten P G; Duran, Karen J; Verheij, Joke B G M; Lugtenberg, Dorien; Nikkels, Peter G J; Brouwer, Henricus G F; Verkade, Henkjan J; Scheenstra, Rene; Spee, Bart; Nieuwenhuis, Edward E S; Coffer, Paul J; Janecke, Andreas R; van Haaften, Gijs; Houwen, Roderick H J; Müller, Thomas; Middendorp, Sabine; Boztug, Kaan

2018-03-29

Congenital diarrheal disorders are rare inherited intestinal disorders characterized by intractable, sometimes life-threatening, diarrhea and nutrient malabsorption; some have been associated with mutations in diacylglycerol-acyltransferase 1 (DGAT1), which catalyzes formation of triacylglycerol from diacylglycerol and acyl-CoA. We investigated the mechanisms by which DGAT1 deficiency contributes to intestinal failure using patient-derived organoids. We collected blood samples from 10 patients, from 6 unrelated pedigrees, who presented with early-onset severe diarrhea and/or vomiting, hypoalbuminemia, and/or (fatal) protein-losing enteropathy with intestinal failure; we performed next-generation sequence analysis of DNA from 8 patients. Organoids were generated from duodenal biopsies from 3 patients and 3 healthy individuals (controls). Caco-2 cells and patient-derived dermal fibroblasts were transfected or transduced with vectors that express full-length or mutant forms of DGAT1 or full-length DGAT2. We performed CRISPR/Cas9-guided disruption of DGAT1 in control intestinal organoids. Cells and organoids were analyzed by immunoblot, immunofluorescence, flow cytometry, chromatography, quantitative real-time polymerase chain reaction, and for activities of caspases 3 and 7. In the 10 patients, we identified 5 bi-allelic loss-of-function mutations in DGAT1. In patient-derived fibroblasts and organoids, the mutations reduced expression of DGAT1 protein and altered triacylglycerol metabolism, resulting in decreased lipid droplet formation after oleic acid addition. Expression of full-length DGAT2 in patient-derived fibroblasts restored formation of lipid droplets. Organoids derived from patients with DGAT1 mutations were more susceptible to lipid-induced cell death than control organoids. We identified a large cohort of patients with congenital diarrheal disorders with mutations in DGAT1 that reduced expression of its product; dermal fibroblasts and intestinal organoids derived from these patients had altered lipid metabolism and were susceptible to lipid-induced cell death. Expression of full-length DGAT1 or DGAT2 restored normal lipid metabolism in these cells. These findings indicate the importance of DGAT1 in fat metabolism and lipotoxicity in the intestinal epithelium. A fat-free diet might serve as the first line of therapy for patients with reduced DGAT1 expression. It is important to identify genetic variants associated with congenital diarrheal disorders for proper diagnosis and selection of treatment strategies. Copyright © 2018 AGA Institute. Published by Elsevier Inc. All rights reserved.

Expression and purification of recombinant tung tree diacylglycerol acyltransferase 2

USDA-ARS?s Scientific Manuscript database

Diacylglycerol acyltransferases (DGATs) catalyze the last step of triacylglycerol (TAG) biosynthesis in eukaryotic organisms. Plants and animals deficient in DGATs accumulate less TAG. Over-expression of DGATs increases TAG. DGAT knockout mice are resistant to diet-induced obesity and lack milk secr...

Accelerated triacylglycerol production and altered fatty acid composition in oleaginous microalga Neochloris oleoabundans by overexpression of diacylglycerol acyltransferase 2.

PubMed

Klaitong, Paeka; Fa-Aroonsawat, Sirirat; Chungjatupornchai, Wipa

2017-04-12

Microalgae are promising sources of lipid triacylglycerol (TAG) for biodiesel production. However, to date, microalgal biodiesel is technically feasible, but not yet economically viable. Increasing TAG content and productivity are important to achieve economic viability of microalgal biodiesel. To increase TAG content, oleaginous microalga Neochloris oleoabundans was genetically engineered with an endogenous key enzyme diacylglycerol acyltransferase 2 (NeoDGAT2) responsible for TAG biosynthesis. The integration of NeoDGAT2 expression cassettes in N. oleoabundans transformant was confirmed by PCR. The neutral lipid accumulation in the transformant detected by Nile red staining was accelerated and 1.9-fold higher than in wild type; the lipid bodies in the transformant visualized under fluorescence microscope were also larger. The NeoDGAT2 transcript was two-fold higher in the transformant than wild type. Remarkably higher lipid accumulation was found in the transformant than wild type: total lipid content increased 1.6-to 2.3-fold up to 74.5 ± 4.0% dry cell weight (DCW) and total lipid productivity increased 1.6- to 3.2-fold up to 14.6 ± 2.0 mg/L/day; while TAG content increased 1.8- to 3.2-fold up to 46.1 ± 1.6% DCW and TAG productivity increased 1.6- to 4.3-fold up to 8.9 ± 1.3 mg/L/day. A significantly altered fatty acid composition was detected in the transformant compared to wild type; the levels of saturated fatty acid C16:0 increased double to 49%, whereas C18:0 was reduced triple to 6%. Long-term stability was observed in the transformant continuously maintained in solid medium over 100 generations in a period of about 4 years. Our results demonstrate the increased TAG content and productivity in N. oleoabundans by NeoDGAT2 overexpression that may offer the first step towards making microalgae an economically feasible source for biodiesel production. The strategy for genetically improved microalga presented in this study can be applied to other microalgal species possessing desired characteristics for industrial biofuel production.

Identification and characterization of a novel DGAT1 missense mutation associated with congenital diarrhea[S

PubMed Central

Gluchowski, Nina L.; Chitraju, Chandramohan; Picoraro, Joseph A.; Mejhert, Niklas; Pinto, Shirly; Xin, Winnie; Kamin, Daniel S.; Winter, Harland S.; Chung, Wendy K.; Walther, Tobias C.; Farese, Robert V.

2017-01-01

Acyl-CoA:diacylglycerol acyltransferase (DGAT)1 and DGAT2 catalyze triglyceride (TG) biosynthesis in humans. Biallelic loss-of-function mutations in human DGAT1 result in severe congenital diarrhea and protein-losing enteropathy. Additionally, pharmacologic inhibition of DGAT1 led to dose-related diarrhea in human clinical trials. Here we identify a previously unknown DGAT1 mutation in identical twins of South Asian descent. These male patients developed watery diarrhea shortly after birth, with protein-losing enteropathy and failure to thrive. Exome sequencing revealed a homozygous recessive mutation in DGAT1, c.314T>C, p.L105P. We show here that the p.L105P DGAT1 enzyme produced from the mutant allele is less abundant, resulting in partial loss of TG synthesis activity and decreased formation of lipid droplets in patient-derived primary dermal fibroblasts. Thus, in contrast with complete loss-of-function alleles of DGAT1, the p.L105P missense allele partially reduces TG synthesis activity and causes a less severe clinical phenotype. Our findings add to the growing recognition of DGAT1 deficiency as a cause of congenital diarrhea with protein-losing enteropathy and indicate that DGAT1 mutations result in a spectrum of diseases. PMID:28373485

Dissociation of hepatic steatosis and insulin resistance in mice overexpressing DGAT in the liver.

PubMed

Monetti, Mara; Levin, Malin C; Watt, Matthew J; Sajan, Mini P; Marmor, Stephen; Hubbard, Brian K; Stevens, Robert D; Bain, James R; Newgard, Christopher B; Farese, Robert V; Hevener, Andrea L; Farese, Robert V

2007-07-01

Hepatic steatosis, the accumulation of lipids in the liver, is widely believed to result in insulin resistance. To test the causal relationship between hepatic steatosis and insulin resistance, we generated mice that overexpress acyl-CoA:diacylglycerol acyltransferase 2 (DGAT2), which catalyzes the final step of triacylglycerol (TG) biosynthesis, in the liver (Liv-DGAT2 mice). Liv-DGAT2 mice developed hepatic steatosis, with increased amounts of TG, diacylglycerol, ceramides, and unsaturated long-chain fatty acyl-CoAs in the liver. However, they had no abnormalities in plasma glucose and insulin levels, glucose and insulin tolerance, rates of glucose infusion and hepatic glucose production during hyperinsulinemic-euglycemic clamp studies, or activities of insulin-stimulated signaling proteins in the liver. DGAT1 overexpression in the liver also failed to induce glucose or insulin intolerance. Our results indicate that DGAT-mediated lipid accumulation in the liver is insufficient to cause insulin resistance and show that hepatic steatosis can occur independently of insulin resistance.

Metabolic control analysis is helpful for informed genetic manipulation of oilseed rape (Brassica napus) to increase seed oil content

PubMed Central

Weselake, Randall J.; Shah, Saleh; Tang, Mingguo; Quant, Patti A.; Snyder, Crystal L.; Furukawa-Stoffer, Tara L.; Zhu, Weiming; Taylor, David C.; Zou, Jitao; Kumar, Arvind; Hall, Linda; Laroche, Andre; Rakow, Gerhard; Raney, Phillip; Moloney, Maurice M.; Harwood, John L.

2008-01-01

Top–down control analysis (TDCA) is a useful tool for quantifying constraints on metabolic pathways that might be overcome by biotechnological approaches. Previous studies on lipid accumulation in oilseed rape have suggested that diacylglycerol acyltransferase (DGAT), which catalyses the final step in seed oil biosynthesis, might be an effective target for enhancing seed oil content. Here, increased seed oil content, increased DGAT activity, and reduced substrate:product ratio are demonstrated, as well as reduced flux control by complex lipid assembly, as determined by TDCA in Brassica napus (canola) lines which overexpress the gene encoding type-1 DGAT. Lines overexpressing DGAT1 also exhibited considerably enhanced seed oil content under drought conditions. These results support the use of TDCA in guiding the rational selection of molecular targets for oilseed modification. The most effective lines had a seed oil increase of 14%. Moreover, overexpression of DGAT1 under drought conditions reduced this environmental penalty on seed oil content. PMID:18703491

Metabolic control analysis is helpful for informed genetic manipulation of oilseed rape (Brassica napus) to increase seed oil content.

PubMed

Weselake, Randall J; Shah, Saleh; Tang, Mingguo; Quant, Patti A; Snyder, Crystal L; Furukawa-Stoffer, Tara L; Zhu, Weiming; Taylor, David C; Zou, Jitao; Kumar, Arvind; Hall, Linda; Laroche, Andre; Rakow, Gerhard; Raney, Phillip; Moloney, Maurice M; Harwood, John L

2008-01-01

Top-down control analysis (TDCA) is a useful tool for quantifying constraints on metabolic pathways that might be overcome by biotechnological approaches. Previous studies on lipid accumulation in oilseed rape have suggested that diacylglycerol acyltransferase (DGAT), which catalyses the final step in seed oil biosynthesis, might be an effective target for enhancing seed oil content. Here, increased seed oil content, increased DGAT activity, and reduced substrate:product ratio are demonstrated, as well as reduced flux control by complex lipid assembly, as determined by TDCA in Brassica napus (canola) lines which overexpress the gene encoding type-1 DGAT. Lines overexpressing DGAT1 also exhibited considerably enhanced seed oil content under drought conditions. These results support the use of TDCA in guiding the rational selection of molecular targets for oilseed modification. The most effective lines had a seed oil increase of 14%. Moreover, overexpression of DGAT1 under drought conditions reduced this environmental penalty on seed oil content.

A soluble diacylglycerol acyltransferase is involved in triacylglycerol biosynthesis in the oleaginous yeast Rhodotorula glutinis.

PubMed

Rani, Sapa Hima; Saha, Saikat; Rajasekharan, Ram

2013-01-01

The biosynthesis of triacylglycerol (TAG) occurs in the microsomal membranes of eukaryotes. Here, we report the identification and functional characterization of diacylglycerol acyltransferase (DGAT), a member of the 10 S cytosolic TAG biosynthetic complex (TBC) in Rhodotorula glutinis. Both a full-length and an N-terminally truncated cDNA clone of a single gene were isolated from R. glutinis. The DGAT activity of the protein encoded by RgDGAT was confirmed in vivo by the heterologous expression of cDNA in a Saccharomyces cerevisiae quadruple mutant (H1246) that is defective in TAG synthesis. RgDGAT overexpression in yeast was found to be capable of acylating diacylglycerol (DAG) in an acyl-CoA-dependent manner. Quadruple mutant yeast cells exhibit growth defects in the presence of oleic acid, but wild-type yeast cells do not. In an in vivo fatty acid supplementation experiment, RgDGAT expression rescued quadruple mutant growth in an oleate-containing medium. We describe a soluble acyl-CoA-dependent DAG acyltransferase from R. glutinis that belongs to the DGAT3 class of enzymes. The study highlights the importance of an alternative TAG biosynthetic pathway in oleaginous yeasts.

Linseed oil and DGAT1 K232A polymorphism: Effects on methane emission, energy and nitrogen metabolism, lactation performance, ruminal fermentation, and rumen microbial composition of Holstein-Friesian cows.

PubMed

van Gastelen, S; Visker, M H P W; Edwards, J E; Antunes-Fernandes, E C; Hettinga, K A; Alferink, S J J; Hendriks, W H; Bovenhuis, H; Smidt, H; Dijkstra, J

2017-11-01

Complex interactions between rumen microbiota, cow genetics, and diet composition may exist. Therefore, the effect of linseed oil, DGAT1 K232A polymorphism (DGAT1), and the interaction between linseed oil and DGAT1 on CH 4 and H 2 emission, energy and N metabolism, lactation performance, ruminal fermentation, and rumen bacterial and archaeal composition was investigated. Twenty-four lactating Holstein-Friesian cows (i.e., 12 with DGAT1 KK genotype and 12 with DGAT1 AA genotype) were fed 2 diets in a crossover design: a control diet and a linseed oil diet (LSO) with a difference of 22 g/kg of dry matter (DM) in fat content between the 2 diets. Both diets consisted of 40% corn silage, 30% grass silage, and 30% concentrates (DM basis). Apparent digestibility, lactation performance, N and energy balance, and CH 4 emission were measured in climate respiration chambers, and rumen fluid samples were collected using the oral stomach tube technique. No linseed oil by DGAT1 interactions were observed for digestibility, milk production and composition, energy and N balance, CH 4 and H 2 emissions, and rumen volatile fatty acid concentrations. The DGAT1 KK genotype was associated with a lower proportion of polyunsaturated fatty acids in milk fat, and with a higher milk fat and protein content, and proportion of saturated fatty acids in milk fat compared with the DGAT1 AA genotype, whereas the fat- and protein-corrected milk yield was unaffected by DGAT1. Also, DGAT1 did not affect nutrient digestibility, CH 4 or H 2 emission, ruminal fermentation or ruminal archaeal and bacterial concentrations. Rumen bacterial and archaeal composition was also unaffected in terms of the whole community, whereas at the genus level the relative abundances of some bacterial genera were found to be affected by DGAT1. The DGAT1 KK genotype was associated with a lower metabolizability (i.e., ratio of metabolizable to gross energy intake), and with a tendency for a lower milk N efficiency compared with the DGAT1 AA genotype. The LSO diet tended to decrease CH 4 production (g/d) by 8%, and significantly decreased CH 4 yield (g/kg of DM intake) by 6% and CH 4 intensity (g/kg of fat- and protein-corrected milk) by 11%, but did not affect H 2 emission. The LSO diet also decreased ruminal acetate molar proportion, the acetate to propionate ratio, and the archaea to bacteria ratio, whereas ruminal propionate molar proportion and milk N efficiency increased. Ruminal bacterial and archaeal composition tended to be affected by diet in terms of the whole community, with several bacterial genera found to be significantly affected by diet. These results indicate that DGAT1 does not affect enteric CH 4 emission and production pathways, but that it does affect traits other than lactation characteristics, including metabolizability, N efficiency, and the relative abundance of Bifidobacterium. Additionally, linseed oil reduces CH 4 emission independent of DGAT1 and affects the rumen microbiota and its fermentative activity. The Authors. Published by the Federation of Animal Science Societies and Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/).

Thematic review series: glycerolipids. DGAT enzymes and triacylglycerol biosynthesis.

PubMed

Yen, Chi-Liang Eric; Stone, Scot J; Koliwad, Suneil; Harris, Charles; Farese, Robert V

2008-11-01

Triacylglycerols (triglycerides) (TGs) are the major storage molecules of metabolic energy and FAs in most living organisms. Excessive accumulation of TGs, however, is associated with human diseases, such as obesity, diabetes mellitus, and steatohepatitis. The final and the only committed step in the biosynthesis of TGs is catalyzed by acyl-CoA:diacylglycerol acyltransferase (DGAT) enzymes. The genes encoding two DGAT enzymes, DGAT1 and DGAT2, were identified in the past decade, and the use of molecular tools, including mice deficient in either enzyme, has shed light on their functions. Although DGAT enzymes are involved in TG synthesis, they have distinct protein sequences and differ in their biochemical, cellular, and physiological functions. Both enzymes may be useful as therapeutic targets for diseases. Here we review the current knowledge of DGAT enzymes, focusing on new advances since the cloning of their genes, including possible roles in human health and diseases.

DGAT enzymes and triacylglycerol biosynthesis

PubMed Central

Yen, Chi-Liang Eric; Stone, Scot J.; Koliwad, Suneil; Harris, Charles; Farese, Robert V.

2008-01-01

Triacylglycerols (triglycerides) (TGs) are the major storage molecules of metabolic energy and FAs in most living organisms. Excessive accumulation of TGs, however, is associated with human diseases, such as obesity, diabetes mellitus, and steatohepatitis. The final and the only committed step in the biosynthesis of TGs is catalyzed by acyl-CoA:diacylglycerol acyltransferase (DGAT) enzymes. The genes encoding two DGAT enzymes, DGAT1 and DGAT2, were identified in the past decade, and the use of molecular tools, including mice deficient in either enzyme, has shed light on their functions. Although DGAT enzymes are involved in TG synthesis, they have distinct protein sequences and differ in their biochemical, cellular, and physiological functions. Both enzymes may be useful as therapeutic targets for diseases. Here we review the current knowledge of DGAT enzymes, focusing on new advances since the cloning of their genes, including possible roles in human health and diseases. PMID:18757836

Molecular Characterization of the Elaeis guineensis Medium-Chain Fatty Acid Diacylglycerol Acyltransferase DGAT1-1 by Heterologous Expression in Yarrowia lipolytica.

PubMed

Aymé, Laure; Jolivet, Pascale; Nicaud, Jean-Marc; Chardot, Thierry

2015-01-01

Diacylglycerol acyltransferases (DGAT) are involved in the acylation of sn-1,2-diacylglycerol. Palm kernel oil, extracted from Elaeis guineensis (oil palm) seeds, has a high content of medium-chain fatty acids mainly lauric acid (C12:0). A putative E. guineensis diacylglycerol acyltransferase gene (EgDGAT1-1) is expressed at the onset of lauric acid accumulation in the seed endosperm suggesting that it is a determinant of medium-chain triacylglycerol storage. To test this hypothesis, we thoroughly characterized EgDGAT1-1 activity through functional complementation of a Yarrowia lipolytica mutant strain devoid of neutral lipids. EgDGAT1-1 expression is sufficient to restore triacylglycerol accumulation in neosynthesized lipid droplets. A comparative functional study with Arabidopsis thaliana DGAT1 highlighted contrasting substrate specificities when the recombinant yeast was cultured in lauric acid supplemented medium. The EgDGAT1-1 expressing strain preferentially accumulated medium-chain triacylglycerols whereas AtDGAT1 expression induced long-chain triacylglycerol storage in Y. lipolytica. EgDGAT1-1 localized to the endoplasmic reticulum where TAG biosynthesis takes place. Reestablishing neutral lipid accumulation in the Y. lipolytica mutant strain did not induce major reorganization of the yeast microsomal proteome. Overall, our findings demonstrate that EgDGAT1-1 is an endoplasmic reticulum DGAT with preference for medium-chain fatty acid substrates, in line with its physiological role in palm kernel. The characterized EgDGAT1-1 could be used to promote medium-chain triacylglycerol accumulation in microbial-produced oil for industrial chemicals and cosmetics.

Molecular Characterization of the Elaeis guineensis Medium-Chain Fatty Acid Diacylglycerol Acyltransferase DGAT1-1 by Heterologous Expression in Yarrowia lipolytica

PubMed Central

Aymé, Laure; Jolivet, Pascale; Nicaud, Jean-Marc; Chardot, Thierry

2015-01-01

Diacylglycerol acyltransferases (DGAT) are involved in the acylation of sn-1,2-diacylglycerol. Palm kernel oil, extracted from Elaeis guineensis (oil palm) seeds, has a high content of medium-chain fatty acids mainly lauric acid (C12:0). A putative E. guineensis diacylglycerol acyltransferase gene (EgDGAT1-1) is expressed at the onset of lauric acid accumulation in the seed endosperm suggesting that it is a determinant of medium-chain triacylglycerol storage. To test this hypothesis, we thoroughly characterized EgDGAT1-1 activity through functional complementation of a Yarrowia lipolytica mutant strain devoid of neutral lipids. EgDGAT1-1 expression is sufficient to restore triacylglycerol accumulation in neosynthesized lipid droplets. A comparative functional study with Arabidopsis thaliana DGAT1 highlighted contrasting substrate specificities when the recombinant yeast was cultured in lauric acid supplemented medium. The EgDGAT1-1 expressing strain preferentially accumulated medium-chain triacylglycerols whereas AtDGAT1 expression induced long-chain triacylglycerol storage in Y. lipolytica. EgDGAT1-1 localized to the endoplasmic reticulum where TAG biosynthesis takes place. Reestablishing neutral lipid accumulation in the Y. lipolytica mutant strain did not induce major reorganization of the yeast microsomal proteome. Overall, our findings demonstrate that EgDGAT1-1 is an endoplasmic reticulum DGAT with preference for medium-chain fatty acid substrates, in line with its physiological role in palm kernel. The characterized EgDGAT1-1 could be used to promote medium-chain triacylglycerol accumulation in microbial-produced oil for industrial chemicals and cosmetics. PMID:26581109

[Polymorphisms of bGH, RORC, and DGAT1 genes in Russian beef cattle breeds].

PubMed

Gorlov, I F; Fedunin, A A; Randelin, D A; Sulimova, G E

2014-12-01

We examined the allelic and genotypic polymorphisms of genes of the retinoic acid receptor-related orphan receptor C (RORC), diacylglycerol acyltransferase-1 (DGAT1), and growth hormone (bGH) in Russian beef cattle breeds in two populations of Kazakh white-headed cattle (of Kazakh and Russian selection) and in the Kalmyk cattle breed and Mongolian hogorogo breed, which is related to Kalmyk breed. The studied genes are associated with parameters of meat quality: marbleness (bGH and RORC) and tenderness (DGAT1). They are also associated with an increase in carcass weight (bGH). We found that Russian and Kazakh populations of the Kazakh white-headed.breed were characterized by a high content of the AA genotype of RORC (0.713 and 0.608, respectively) and of the AA genotype of DGAT1 (0.913 and 0.975), both of which are preferable for meat quality. The total frequencies for the combined genotypes for the bGH and RORC genes, which provide for superior meat quality and carcass weight, in the populations of Kazakh white-headed cattle (GG/AA and GC/AA-68.8% and 57% in the Russian and Kazakh populations, respectively) exceeded the frequencies in the two other studied breeds by two times. Overall, the obtained results point to the high genetic potential of both populations of Kazakh white-headed cattle breeds in beef production. Results of this study can be used to improve the selection of meat traits in industrial livestock.

Discovery of a low-systemic-exposure DGAT-1 inhibitor with a picolinoylpyrrolidine-2-carboxylic acid moiety.

PubMed

Yan, Jianwei; Wang, Gaihong; Dang, Xiangyu; Guo, Binbin; Chen, Wuhong; Wang, Ting; Zeng, Limin; Wang, Heyao; Hu, Youhong

2017-09-01

A series of diacylglycerol O-acyltransferase 1 (DGAT-1) inhibitors with a picolinoylpyrrolidine-2-carboxylic acid moiety were designed and synthesized. Of these compounds, compound 22 exhibited excellent DGAT-1-inhibitory activity (hDGAT-1 enzyme assay, 50% inhibitory concentration [IC 50 ]=3.5±0.9nM) and effectively reduced the intracellular triglyceride contents in 3T3-L1, HepG2 and Caco-2 cells. A preliminary study of the plasma and tissue distributions of compound 22 in mice revealed low plasma exposure and high concentrations in different segments of the intestine and liver, which may facilitate targeting DGAT-1. Furthermore, in an acute lipid challenge test, compound 22 showed a dose-dependent inhibitory effect on high-serum triglycerides in C57/KSJ mice induced by olive oil (1, 3, and 10mg/kg, i.g.). Copyright © 2017 Elsevier Ltd. All rights reserved.

Vernonia DGATs can complement the disrupted oil and protein metabolism in epoxygenase-expressing soybean seeds.

PubMed

Li, Runzhi; Yu, Keshun; Wu, Yongmei; Tateno, Mizuki; Hatanaka, Tomoko; Hildebrand, David F

2012-01-01

Plant oils can be useful chemical feedstocks such as a source of epoxy fatty acids. High seed-specific expression of a Stokesia laevis epoxygenase (SlEPX) in soybeans only results in 3-7% epoxide levels. SlEPX-transgenic soybean seeds also exhibited other phenotypic alterations, such as altered seed fatty acid profiles, reduced oil accumulation, and variable protein levels. SlEPX-transgenic seeds showed a 2-5% reduction in total oil content and protein levels of 30.9-51.4%. To address these pleiotrophic effects of SlEPX expression on other traits, transgenic soybeans were developed to co-express SlEPX and DGAT (diacylglycerol acyltransferase) genes (VgDGAT1 & 2) isolated from Vernonia galamensis, a high accumulator of epoxy fatty acids. These side effects of SlEPX expression were largely overcome in the DGAT co-expressing soybeans. Total oil and protein contents were restored to the levels in non-transgenic soybeans, indicating that both VgDGAT1 and VgDGAT2 could complement the disrupted phenotypes caused by over-expression of an epoxygenase in soybean seeds. Copyright © 2011 Elsevier Inc. All rights reserved.

Effects of tung oilseed FAD2 and DGAT2 genes on unsaturated fatty acid accumulation in Rhodotorula glutinis and Arabidopsis thaliana.

PubMed

Chen, Yicun; Cui, Qinqin; Xu, Yongjie; Yang, Susu; Gao, Ming; Wang, Yangdong

2015-08-01

Genetic engineering to produce valuable lipids containing unsaturated fatty acids (UFAs) holds great promise for food and industrial applications. Efforts to genetically modify plants to produce desirable UFAs with single enzymes, however, have had modest success. The key enzymes fatty acid desaturase (FAD) and diacylglycerol acyltransferase (DGAT) are responsible for UFA biosynthesis (a push process) and assembling fatty acids into lipids (a pull process) in plants, respectively. To examine their roles in UFA accumulation, VfFAD2 and VfDGAT2 genes cloned from Vernicia fordii (tung tree) oilseeds were conjugated and transformed into Rhodotorula glutinis and Arabidopsis thaliana via Agrobacterium tumefaciens. Real-time quantitative PCR revealed variable gene expression levels in the transformants, with a much higher level of VfDGAT2 than VfFAD2. The relationship between VfFAD2 expression and linoleic acid (C18:2) increases in R. glutinis (R (2) = 0.98) and A. thaliana (R (2) = 0.857) transformants was statistically linear. The VfDGAT2 expression level was statistically correlated with increased total fatty acid content in R. glutinis (R (2) = 0.962) and A. thaliana (R (2) = 0.8157) transformants. With a similar expression level between single- and two-gene transformants, VfFAD2-VfDGAT2 co-transformants showed a higher linolenic acid (C18:3) yield in R. glutinis (174.36 % increase) and A. thaliana (14.61 % increase), and eicosatrienoic acid (C20:3) was enriched (17.10 % increase) in A. thaliana. Our data suggest that VfFAD2-VfDGAT2 had a synergistic effect on UFA metabolism in R. glutinis, and to a lesser extent, A. thaliana. These results show promise for further genetic engineering of plant lipids to produce desirable UFAs.

Engineering Camelina sativa (L.) Crantz for enhanced oil and seed yields by combining diacylglycerol acyltransferase1 and glycerol-3-phosphate dehydrogenase expression.

PubMed

Chhikara, Sudesh; Abdullah, Hesham M; Akbari, Parisa; Schnell, Danny; Dhankher, Om Parkash

2018-05-01

Plant seed oil-based liquid transportation fuels (i.e., biodiesel and green diesel) have tremendous potential as environmentally, economically and technologically feasible alternatives to petroleum-derived fuels. Due to their nutritional and industrial importance, one of the major objectives is to increase the seed yield and oil production of oilseed crops via biotechnological approaches. Camelina sativa, an emerging oilseed crop, has been proposed as an ideal crop for biodiesel and bioproduct applications. Further increase in seed oil yield by increasing the flux of carbon from increased photosynthesis into triacylglycerol (TAG) synthesis will make this crop more profitable. To increase the oil yield, we engineered Camelina by co-expressing the Arabidopsis thaliana (L.) Heynh. diacylglycerol acyltransferase1 (DGAT1) and a yeast cytosolic glycerol-3-phosphate dehydrogenase (GPD1) genes under the control of seed-specific promoters. Plants co-expressing DGAT1 and GPD1 exhibited up to 13% higher seed oil content and up to 52% increase in seed mass compared to wild-type plants. Further, DGAT1- and GDP1-co-expressing lines showed significantly higher seed and oil yields on a dry weight basis than the wild-type controls or plants expressing DGAT1 and GPD1 alone. The oil harvest index (g oil per g total dry matter) for DGTA1- and GPD1-co-expressing lines was almost twofold higher as compared to wild type and the lines expressing DGAT1 and GPD1 alone. Therefore, combining the overexpression of TAG biosynthetic genes, DGAT1 and GPD1, appears to be a positive strategy to achieve a synergistic effect on the flux through the TAG synthesis pathway, and thereby further increase the oil yield. © 2017 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

A phenylalanine in DGAT is a key determinant of oil content and composition in maize.

PubMed

Zheng, Peizhong; Allen, William B; Roesler, Keith; Williams, Mark E; Zhang, Shirong; Li, Jiming; Glassman, Kimberly; Ranch, Jerry; Nubel, Douglas; Solawetz, William; Bhattramakki, Dinakar; Llaca, Victor; Deschamps, Stéphane; Zhong, Gan-Yuan; Tarczynski, Mitchell C; Shen, Bo

2008-03-01

Plant oil is an important renewable resource for biodiesel production and for dietary consumption by humans and livestock. Through genetic mapping of the oil trait in plants, studies have reported multiple quantitative trait loci (QTLs) with small effects, but the molecular basis of oil QTLs remains largely unknown. Here we show that a high-oil QTL (qHO6) affecting maize seed oil and oleic-acid contents encodes an acyl-CoA:diacylglycerol acyltransferase (DGAT1-2), which catalyzes the final step of oil synthesis. We further show that a phenylalanine insertion in DGAT1-2 at position 469 (F469) is responsible for the increased oil and oleic-acid contents. The DGAT1-2 allele with F469 is ancestral, whereas the allele without F469 is a more recent mutant selected by domestication or breeding. Ectopic expression of the high-oil DGAT1-2 allele increases oil and oleic-acid contents by up to 41% and 107%, respectively. This work provides insights into the molecular basis of natural variation of oil and oleic-acid contents in plants and highlights DGAT as a promising target for increasing oil and oleic-acid contents in other crops.

Structure-function analysis of diacylglycerol acyltransferase sequences from tung tree and 82 other Organisms

USDA-ARS?s Scientific Manuscript database

Diacylglycerol acyltransferase family (DGATs) catalyzes the final and rate-limiting step of triacylglycerol (TAG) biosynthesis in eukaryotic organisms. DGATs esterify sn-1,2-diacylglycerol with a long-chain fatty acyl-CoA. Understanding the roles of DGATs will help to create transgenic plants with v...

[Progress in the study on mammalian diacylgycerol acyltransgerase (DGAT) gene and its biological function].

PubMed

Wang, Yan; Xu, Heng-Yong; Zhu, Qing

2007-10-01

Diacylglycerol acyltransferase (DGAT; EC 2.3.1.20) is a microsomal enzyme that plays a central role in the metabolism of cellular glycerolipids. DGAT catalyzes the final step in triacylglycerol (TAG) biosynthesis by converting diacylgycerol (DAG) and fatty acyl-coenzyme A (CoA) into triacylglycero1. DGAT plays a fundamental role in the metabolism of cellular diacylglycerol and is important in higher eukaryotes for physiologic processes involving triacylglycerol metabolism such as intestinal fat absorption, lipoprotein assembly, adipose tissue formation, and lactation. Therefore, DGAT is not only an key factor for control triglycerides and fatty acids, but also may play a key modulatory role in animal fat deposition.

Identification of a pair of phospholipid:diacylglycerol acyltransferases from developing flax (Linum usitatissimum L.) seed catalyzing the selective production of trilinolenin.

PubMed

Pan, Xue; Siloto, Rodrigo M P; Wickramarathna, Aruna D; Mietkiewska, Elzbieta; Weselake, Randall J

2013-08-16

The oil from flax (Linum usitatissimum L.) has high amounts of α-linolenic acid (ALA; 18:3(cis)(Δ9,12,15)) and is one of the richest sources of omega-3 polyunsaturated fatty acids (ω-3-PUFAs). To produce ∼57% ALA in triacylglycerol (TAG), it is likely that flax contains enzymes that can efficiently transfer ALA to TAG. To test this hypothesis, we conducted a systematic characterization of TAG-synthesizing enzymes from flax. We identified several genes encoding acyl-CoA:diacylglycerol acyltransferases (DGATs) and phospholipid:diacylglycerol acyltransferases (PDATs) from the flax genome database. Due to recent genome duplication, duplicated gene pairs have been identified for all genes except DGAT2-2. Analysis of gene expression indicated that two DGAT1, two DGAT2, and four PDAT genes were preferentially expressed in flax embryos. Yeast functional analysis showed that DGAT1, DGAT2, and two PDAT enzymes restored TAG synthesis when produced recombinantly in yeast H1246 strain. The activity of particular PDAT enzymes (LuPDAT1 and LuPDAT2) was stimulated by the presence of ALA. Further seed-specific expression of flax genes in Arabidopsis thaliana indicated that DGAT1, PDAT1, and PDAT2 had significant effects on seed oil phenotype. Overall, this study indicated the existence of unique PDAT enzymes from flax that are able to preferentially catalyze the synthesis of TAG containing ALA acyl moieties. The identified LuPDATs may have practical applications for increasing the accumulation of ALA and other polyunsaturated fatty acids in oilseeds for food and industrial applications.

Design and synthesis of potent, orally-active DGAT-1 inhibitors containing a dioxino[2,3-d]pyrimidine core.

PubMed

Dow, Robert L; Andrews, Melissa; Aspnes, Gary E; Balan, Gayatri; Michael Gibbs, E; Guzman-Perez, Angel; Karki, Kapil; Laperle, Jennifer L; Li, Jian-Cheng; Litchfield, John; Munchhof, Michael J; Perreault, Christian; Patel, Leena

2011-10-15

A novel series of potent DGAT-1 inhibitors was developed originating from the lactam-based clinical candidate PF-04620110. Incorporation of a dioxino[2,3-d]pyrimidine-based core afforded good alignment of pharmacophore features and resulted in improved passive permeability. Development of an efficient, homochiral synthesis of these targets facilitated confirmation of predictions regarding the stereochemical-dependence of DGAT-1 inhibition for this series. Compound 10 was shown to be a potent inhibitor of human DGAT-1 (10 nM) and to suppress triglyceride synthesis at oral doses of <3mg/kg. Copyright © 2011 Elsevier Ltd. All rights reserved.

The role of acyl-CoA:diacylglycerol acyltransferase (DGAT) in energy metabolism.

PubMed

Yu, Yi-Hao; Ginsberg, Henry N

2004-01-01

Acyl-CoA:diacylglycerol acyltransferase (DGAT, EC2.3.1.20), a key enzyme in triglyceride (TG) biosynthesis, not only participates in lipid metabolism but also influences metabolic pathways of other fuel molecules. Changes in the expression and/or activity levels of DGAT may lead to changes in systemic insulin sensitivity and energy homeostasis. The synthetic role of DGAT in adipose tissue, the liver, and the intestine, sites where endogenous levels of DGAT activity and TG synthesis are high, is relatively clear. Less clear is whether DGAT plays a mediating or preventive role in the development of ectopic lipotoxicity in tissues such as muscle and the pancreas, when their supply of free fatty acids (FFAs) exceeds their needs. Future studies with tissue-specific overexpression and/or knockout in these animal models would be expected to shed additional light on these issues.

Trivalent chromium alleviates oleic acid induced steatosis in SMMC-7721 cells by decreasing fatty acid uptake and triglyceride synthesis.

PubMed

Wang, Song; Wang, Jian; Zhang, Xiaonan; Hu, Linlin; Fang, Zhijia; Huang, Zhiwei; Shi, Ping

2016-10-01

Trivalent chromium [Cr(III)] has been shown as an essential trace element for human health. Previous studies depict that Cr(III) plays important roles in maintaining normal glucose and lipid metabolism, whereas its effect on the hepatic lipid metabolism is still unknown. In the present study, we investigated the effects and underlying mechanisms of Cr on hepatic steatosis induced by oleic acid (OA) in human hepatoma SMMC-7721 cells. Hepatic steatosis model was co-administered with Cr. Indexes of lipid accumulation were determined and associated genes expression were analyzed. The data showed that OA could induce lipid accumulation and triglyceride (TG) content in SMMC-7721 cells, and significantly increase the expression of cluster of differentiation 36 (CD36) and diacylglycerol acyltransferase 2 (DGAT2). This steatosis effect of OA was ameliorated by Cr. The TG accumulation and up-regulation of CD36 and DGAT2 genes followed steatosis induction were inhibited by Cr. After the treatment of Cr, excessive intracellular OA content was also attenuated. Furthermore, Cr still performed inhibitory effect of DGAT2 expression at the presence of DGAT2 agonist or inhibitor, which indicated that the inhibitory effect of Cr on lipogenesis is associated with the downregulation of DGAT2 expression. These findings demonstrate that Cr alleviates hepatic steatosis via suppressing CD36 expression to prevent fatty acid uptake, as well as suppressing DGAT2 expression to inhibit TG synthesis. It suggests that CD36 and DGAT2 might become the novel drug targets for their properties in hepatic steatosis. Most importantly, Cr may be a potential anti-steatosis candidate to offer protective effects against liver damage.

Gene expression profiling of astaxanthin and fatty acid pathways in Haematococcus pluvialis in response to different LED lighting conditions.

PubMed

Ma, Ruijuan; Thomas-Hall, Skye R; Chua, Elvis T; Alsenani, Faisal; Eltanahy, Eladl; Netzel, Michael E; Netzel, Gabriele; Lu, Yinghua; Schenk, Peer M

2018-02-01

Haematococcus pluvialis is a green microalga of major interest to industry based on its ability to produce large amounts of astaxanthin. Biosynthesis of astaxanthin and its mono- and di-esters was significantly stimulated under 150 μmol m -2 s -1 of white LED (W-150) compared with lower light intensities, but the highest astaxanthin amounts were produced under 70 μmol m -2 s -1 of blue LED (B-70). Transcripts of astaxanthin biosynthesis genes psy, crtO, and bkt2 were upregulated under W-150, while psy, lcy, crtO, and crtR-B were upregulated by B-70. Total fatty acid content and biosynthesis genes fata and all dgat genes were induced under W-150, while C18:3n6 biosynthesis and dgat2a expression were specifically stimulated by B-70 which was correlated to astaxanthin ester biosynthesis. Nitrogen starvation, various LEDs and the identified upregulated genes may provide useful tools for future metabolic engineering to significantly increase free astaxanthin, its esters and fatty acid precursors in H. pluvialis. Copyright © 2017 Elsevier Ltd. All rights reserved.

Distinct ontogenic patterns of overt and latent DGAT activities of rat liver microsomes.

PubMed

Waterman, Ian J; Price, Nigel T; Zammit, Victor A

2002-09-01

We have studied the ontogeny of the two functional diacylglycerol acyltransferase (DGAT) activities (overt and latent) during postnatal development in rat liver. We find that the ontogenic patterns of the two are highly distinct. Overt DGAT shows a transient rise in activity up to day 4 postnatally, after which it declines until weaning; thereafter, it increases steadily to reach high adult values that may contribute to the high rates of turnover of cytosolic triacylglycerol (TAG). By contrast, latent DGAT activity increases continuously during the suckling period but falls sharply upon weaning onto chow but not onto a high-fat diet. Rates of TAG secretion by hepatocytes are higher than in the adult during the first 7 days after birth, and are largely dependent on the mobilization of the abundant intrahepatocyte TAG as a source of acyl moieties. When the hepatic steatosis is cleared (after day 7) the TAG secretion rate declines by 80% to reach adult values. Quantification of the content of mRNA for the DGAT1 and DGAT2 genes does not show correlation with either of the DGAT activities. We conclude that post-translational modification may play an important role in the overt and latent distribution of DGAT activity in the liver microsomal membrane.

Identification of a Pair of Phospholipid:Diacylglycerol Acyltransferases from Developing Flax (Linum usitatissimum L.) Seed Catalyzing the Selective Production of Trilinolenin*

PubMed Central

Pan, Xue; Siloto, Rodrigo M. P.; Wickramarathna, Aruna D.; Mietkiewska, Elzbieta; Weselake, Randall J.

2013-01-01

The oil from flax (Linum usitatissimum L.) has high amounts of α-linolenic acid (ALA; 18:3cisΔ9,12,15) and is one of the richest sources of omega-3 polyunsaturated fatty acids (ω-3-PUFAs). To produce ∼57% ALA in triacylglycerol (TAG), it is likely that flax contains enzymes that can efficiently transfer ALA to TAG. To test this hypothesis, we conducted a systematic characterization of TAG-synthesizing enzymes from flax. We identified several genes encoding acyl-CoA:diacylglycerol acyltransferases (DGATs) and phospholipid:diacylglycerol acyltransferases (PDATs) from the flax genome database. Due to recent genome duplication, duplicated gene pairs have been identified for all genes except DGAT2-2. Analysis of gene expression indicated that two DGAT1, two DGAT2, and four PDAT genes were preferentially expressed in flax embryos. Yeast functional analysis showed that DGAT1, DGAT2, and two PDAT enzymes restored TAG synthesis when produced recombinantly in yeast H1246 strain. The activity of particular PDAT enzymes (LuPDAT1 and LuPDAT2) was stimulated by the presence of ALA. Further seed-specific expression of flax genes in Arabidopsis thaliana indicated that DGAT1, PDAT1, and PDAT2 had significant effects on seed oil phenotype. Overall, this study indicated the existence of unique PDAT enzymes from flax that are able to preferentially catalyze the synthesis of TAG containing ALA acyl moieties. The identified LuPDATs may have practical applications for increasing the accumulation of ALA and other polyunsaturated fatty acids in oilseeds for food and industrial applications. PMID:23824186

Association of DGAT2 gene polymorphisms with carcass and meat quality traits in domestic pigeons (Columba livia).

PubMed

Mao, H G; Dong, X Y; Cao, H Y; Xu, N Y; Yin, Z Z

2018-04-01

1. Diacylglycerol acyltransferase (DGAT) plays an important role in the synthesis of triacylglycerol, but its effects on meat quality and carcass composition in pigeons are unclear. In this study, single-nucleotide polymorphisms (SNPs) in the exons of the DGAT2 gene were identified and analysed by using DNA sequencing methods in 200 domestic pigeons (Columba livia). The associations between DGAT2 polymorphisms and carcass and meat quality traits were also analysed. 2. Sequencing results showed that 5 nucleotide mutations were detected in exons 3, 4, 5 and 6 of the DGAT2 gene. The analysis revealed three genotypes (AA, AB and BB) in G18398T and G22484C, in which the AA genotype and A allele had the highest frequency. 3. In the SNP of G18398T located in exon 5, individuals with genotype BB had significantly higher meat quality and lower abdominal fat content than those with AA or AB genotype. In the SNP of G22484C located in exon 6, the genotype AA showed highest carcass trait values, while the genotype BB represented better meat quality, compared to AA and AB genotypes. 4. The results imply that DGAT2 gene has a close relationship with carcass and meat quality traits in pigeons, and the SNPs of G18398T and G22484C can be used as genetic markers for marker-assisted breeding in pigeon.

Synthesis of neutral ether lipid monoalkyl-diacylglycerol by lipid acyltransferases[S

PubMed Central

Ma, Zhengping; Onorato, Joelle M.; Chen, Luping; Nelson, David W.; Yen, Chi-Liang Eric; Cheng, Dong

2017-01-01

In mammals, ether lipids exert a wide spectrum of signaling and structural functions, such as stimulation of immune responses, anti-tumor activities, and enhancement of sperm functions. Abnormal accumulation of monoalkyl-diacylglycerol (MADAG) was found in Wolman’s disease, a human genetic disorder defined by a deficiency in lysosomal acid lipase. In the current study, we found that among the nine recombinant human lipid acyltransferases examined, acyl-CoA:diacylglycerol acyltransferase (DGAT)1, DGAT2, acyl-CoA:monoacylglycerol acyltransferase (MGAT)2, MGAT3, acyl-CoA:wax-alcohol acyltransferase 2/MFAT, and DGAT candidate 3 were able to use 1-monoalkylglycerol (1-MAkG) as an acyl acceptor for the synthesis of monoalkyl-monoacylglycerol (MAMAG). These enzymes demonstrated different enzymatic turnover rates and relative efficiencies for the first and second acylation steps leading to the synthesis of MAMAG and MADAG, respectively. They also exhibited different degrees of substrate preference when presented with 1-monooleoylglycerol versus 1-MAkG. In CHO-K1 cells, treatment with DGAT1 selective inhibitor, XP-620, completely blocked the synthesis of MADAG, indicating that DGAT1 is the predominant enzyme responsible for the intracellular synthesis of MADAG in this model system. The levels of MADAG in the adrenal gland of DGAT1 KO mice were reduced as compared with those of the WT mice, suggesting that DGAT1 is a major enzyme for the synthesis of MADAG in this tissue. Our findings indicate that several of these lipid acyltransferases may be able to synthesize neutral ether lipids in mammals. PMID:28420705

Using the candidate gene approach for detecting genes underlying seed oil concentration and yield in soybean.

PubMed

Eskandari, Mehrzad; Cober, Elroy R; Rajcan, Istvan

2013-07-01

Increasing the oil concentration in soybean seeds has been given more attention in recent years because of demand for both edible oil and biodiesel production. Oil concentration in soybean is a complex quantitative trait regulated by many genes as well as environmental conditions. To identify genes governing seed oil concentration in soybean, 16 putative candidate genes of three important gene families (GPAT: acyl-CoA:sn-glycerol-3-phosphate acyltransferase, DGAT: acyl-CoA:diacylglycerol acyltransferase, and PDAT: phospholipid:diacylglycerol acyltransferase) involved in triacylglycerol (TAG) biosynthesis pathways were selected and their sequences retrieved from the soybean database ( http://www.phytozome.net/soybean ). Three sequence mutations were discovered in either coding or noncoding regions of three DGAT soybean isoforms when comparing the parents of a 203 recombinant inbreed line (RIL) population; OAC Wallace and OAC Glencoe. The RIL population was used to study the effects of these mutations on seed oil concentration and other important agronomic and seed composition traits, including seed yield and protein concentration across three field locations in Ontario, Canada, in 2009 and 2010. An insertion/deletion (indel) mutation in the GmDGAT2B gene in OAC Wallace was significantly associated with reduced seed oil concentration across three environments and reduced seed yield at Woodstock in 2010. A mutation in the 3' untranslated (3'UTR) region of GmDGAT2C was associated with seed yield at Woodstock in 2009. A mutation in the intronic region of GmDGAR1B was associated with seed yield and protein concentration at Ottawa in 2010. The genes identified in this study had minor effects on either seed yield or oil concentration, which was in agreement with the quantitative nature of the traits. However, the novel gene-specific markers designed in the present study can be used in soybean breeding for marker-assisted selection aimed at increasing seed yield and oil concentration with no significant impact on seed protein concentration.

Deconstructing the DGAT1 enzyme: membrane interactions at substrate binding sites.

PubMed

Lopes, Jose L S; Beltramini, Leila M; Wallace, Bonnie A; Araujo, Ana P U

2015-01-01

Diacylglycerol acyltransferase 1 (DGAT1) is a key enzyme in the triacylglyceride synthesis pathway. Bovine DGAT1 is an endoplasmic reticulum membrane-bound protein associated with the regulation of fat content in milk and meat. The aim of this study was to evaluate the interaction of DGAT1 peptides corresponding to putative substrate binding sites with different types of model membranes. Whilst these peptides are predicted to be located in an extramembranous loop of the membrane-bound protein, their hydrophobic substrates are membrane-bound molecules. In this study, peptides corresponding to the binding sites of the two substrates involved in the reaction were examined in the presence of model membranes in order to probe potential interactions between them that might influence the subsequent binding of the substrates. Whilst the conformation of one of the peptides changed upon binding several types of micelles regardless of their surface charge, suggesting binding to hydrophobic domains, the other peptide bound strongly to negatively-charged model membranes. This binding was accompanied by a change in conformation, and produced leakage of the liposome-entrapped dye calcein. The different hydrophobic and electrostatic interactions observed suggest the peptides may be involved in the interactions of the enzyme with membrane surfaces, facilitating access of the catalytic histidine to the triacylglycerol substrates.

Effect of 50 Hz electric field in diacylglycerol acyltransferase mRNA expression level and plasma concentration of triacylglycerol, free fatty acid, phospholipid and total cholesterol

PubMed Central

2012-01-01

Background The effects of exposure to a 50 Hz electric field (EF) on plasma level of triacylglycerol, free fatty acids, total cholesterol and phospholipid and mRNA expression level of diacylglycerol acyltransferase (DGAT) 1 and 2 in liver and intestines from C57BL/6 J mice were studied. Methods The test was based on comparison between mice post treated with 50 Hz EF of 45 kV/m intensity for 30 min per day for 11 days or without EF. DGATs mRNA expression was analyzed by real-time quantitative polymerase chain reaction. Results There was no difference in the gene expression level of DGAT1 in liver and intestines. The DGAT2 gene expression level in liver derived from mice treated with EF was significantly lower than those in the control (P < 0.001). Both plasma total cholesterol (P < 0.01) and phospholipid (P < 0.05) in the group exposed to EF were lower than those in the control, but there was no difference in triacylglycerol or free fatty acid levels. Conclusion Exposure to 50 Hz EF decrease the plasma levels of total cholesterol and phospholipids, and downregulated DGAT2 mRNA expression in liver. The mechanisms for the effects of EF on lipid metabolism are not well understand yet, but altered DGAT2 activity may be involved. PMID:22676350

Diacylglycerol acyltransferase-1 inhibition enhances intestinal fatty acid oxidation and reduces energy intake in rats[S

PubMed Central

Schober, Gudrun; Arnold, Myrtha; Birtles, Susan; Buckett, Linda K.; Pacheco-López, Gustavo; Turnbull, Andrew V.; Langhans, Wolfgang; Mansouri, Abdelhak

2013-01-01

Acyl CoA:diacylglycerol acyltransferase-1 (DGAT-1) catalyzes the final step in triacylglycerol (TAG) synthesis and is highly expressed in the small intestine. Because DGAT-1 knockout mice are resistant to diet-induced obesity, we investigated the acute effects of intragastric (IG) infusion of a small molecule diacylglycerol acyltransferase-1 inhibitor (DGAT-1i) on eating, circulating fat metabolites, indirect calorimetry, and hepatic and intestinal expression of key fat catabolism enzymes in male rats adapted to an 8 h feeding-16 h deprivation schedule. Also, the DGAT-1i effect on fatty acid oxidation (FAO) was investigated in enterocyte cell culture models. IG DGAT-1i infusions reduced energy intake compared with vehicle in high-fat diet (HFD)-fed rats, but scarcely in chow-fed rats. IG DGAT-1i also blunted the postprandial increase in serum TAG and increased β-hydroxybutyrate levels only in HFD-fed rats, in which it lowered the respiratory quotient and increased intestinal, but not hepatic, protein levels of Complex III of the mitochondrial respiratory chain and of mitochondrial hydroxymethylglutaryl-CoA synthase. Finally, the DGAT-1i enhanced FAO in CaCo2 (EC50 = 0.3494) and HuTu80 (EC50 = 0.00762) cells. Thus, pharmacological DGAT-1 inhibition leads to an increase in intestinal FAO and ketogenesis when dietary fat is available. This may contribute to the observed eating-inhibitory effect. PMID:23449193

Transgenic increases in seed oil content are associated with the differential expression of novel Brassica-specific transcripts.

PubMed

Sharma, Nirmala; Anderson, Maureen; Kumar, Arvind; Zhang, Yan; Giblin, E Michael; Abrams, Suzanne R; Zaharia, L Irina; Taylor, David C; Fobert, Pierre R

2008-12-19

Seed oil accumulates primarily as triacylglycerol (TAG). While the biochemical pathway for TAG biosynthesis is known, its regulation remains unclear. Previous research identified microsomal diacylglycerol acyltransferase 1 (DGAT1, EC 2.3.1.20) as controlling a rate-limiting step in the TAG biosynthesis pathway. Of note, overexpression of DGAT1 results in substantial increases in oil content and seed size. To further analyze the global consequences of manipulating DGAT1 levels during seed development, a concerted transcriptome and metabolome analysis of transgenic B. napus prototypes was performed. Using a targeted Brassica cDNA microarray, about 200 genes were differentially expressed in two independent transgenic lines analyzed. Interestingly, 24-33% of the targets showing significant changes have no matching gene in Arabidopsis although these represent only 5% of the targets on the microarray. Further analysis of some of these novel transcripts indicated that several are inducible by ABA in microspore-derived embryos. Of the 200 Arabidopsis genes implicated in lipid biology present on the microarray, 36 were found to be differentially regulated in DGAT transgenic lines. Furthermore, kinetic reverse transcriptase Polymerase Chain Reaction (k-PCR) analysis revealed up-regulation of genes encoding enzymes of the Kennedy pathway involved in assembly of TAGs. Hormone profiling indicated that levels of auxins and cytokinins varied between transgenic lines and untransformed controls, while differences in the pool sizes of ABA and catabolites were only observed at later stages of development. Our results indicate that the increased TAG accumulation observed in transgenic DGAT1 plants is associated with modest transcriptional and hormonal changes during seed development that are not limited to the TAG biosynthesis pathway. These might be associated with feedback or feed-forward effects due to altered levels of DGAT1 activity. The fact that a large fraction of significant amplicons have no matching genes in Arabidopsis compromised our ability to draw concrete inferences from the data at this stage, but has led to the identification of novel genes of potential interest.

In vivo efficacy of acyl CoA: diacylglycerol acyltransferase (DGAT) 1 inhibition in rodent models of postprandial hyperlipidemia.

PubMed

King, Andrew J; Segreti, Jason A; Larson, Kelly J; Souers, Andrew J; Kym, Philip R; Reilly, Regina M; Collins, Christine A; Voorbach, Martin J; Zhao, Gang; Mittelstadt, Scott W; Cox, Bryan F

2010-07-10

Postprandial serum triglyceride concentrations have recently been identified as a major, independent risk factor for future cardiovascular events. As a result, postprandial hyperlipidemia has emerged as a potential therapeutic target. The purpose of this study was two-fold. Firstly, to describe and characterize a standardized model of postprandial hyperlipidemia in multiple rodent species; and secondly, apply these rodent models to the evaluation of a novel class of pharmacologic agent; acyl CoA:diacylglycerol acyltransferase (DGAT) 1 inhibitors. Serum triglycerides were measured before and for 4h after oral administration of a standardized volume of corn oil, to fasted C57BL/6, ob/ob, apoE(-/-) and CD-1 mice; Sprague-Dawley and JCR/LA-cp rats; and normolipidemic and hyperlipidemic hamsters. Intragastric administration of corn oil increased serum triglycerides in all animals evaluated, however the magnitude and time-course of the postprandial triglyceride excursion varied. The potent and selective DGAT-1 inhibitor A-922500 (0.03, 0.3 and 3 mg/kg, p.o.), dose-dependently attenuated the maximal postprandial rise in serum triglyceride concentrations in all species tested. At the highest dose of DGAT-1 inhibitor, the postprandial triglyceride response was abolished. This study provides a comprehensive characterization of the time-course of postprandial hyperlipidemia in rodents. In addition, the ability of DGAT-1 inhibitors to attenuate postprandial hyperlipidemia in multiple rodent models, including those that feature insulin resistance, is documented. Exaggerated postprandial hyperlipidemia is inherent to insulin-resistant states in humans and contributes to the substantially elevated cardiovascular risk observed in these patients. Therefore, by attenuating postprandial hyperlipidemia, DGAT-1 inhibition may represent a novel therapeutic approach to reduce cardiovascular risk. Copyright 2010 Elsevier B.V. All rights reserved.

Obesity resistance and multiple mechanisms of triglyceride synthesis in mice lacking Dgat.

PubMed

Smith, S J; Cases, S; Jensen, D R; Chen, H C; Sande, E; Tow, B; Sanan, D A; Raber, J; Eckel, R H; Farese, R V

2000-05-01

Triglycerides (or triacylglycerols) represent the major form of stored energy in eukaryotes. Triglyceride synthesis has been assumed to occur primarily through acyl CoA:diacylglycerol transferase (Dgat), a microsomal enzyme that catalyses the final and only committed step in the glycerol phosphate pathway. Therefore, Dgat has been considered necessary for adipose tissue formation and essential for survival. Here we show that Dgat-deficient (Dgat-/-) mice are viable and can still synthesize triglycerides. Moreover, these mice are lean and resistant to diet-induced obesity. The obesity resistance involves increased energy expenditure and increased activity. Dgat deficiency also alters triglyceride metabolism in other tissues, including the mammary gland, where lactation is defective in Dgat-/- females. Our findings indicate that multiple mechanisms exist for triglyceride synthesis and suggest that the selective inhibition of Dgat-mediated triglyceride synthesis may be useful for treating obesity.

Expression and purification of diacylglycerol acyltransferases

USDA-ARS?s Scientific Manuscript database

Diacylglycerol acyltransferases (DGATs) are integral membrane proteins that catalyze the last step of triacylglycerol (TAG) biosynthesis in eukaryotic organisms. Plants and animals deficient in DGATs accumulate less TAG and over-expression of DGATs increases TAG. DGAT knockout mice are resistant to ...

New polyacetylenes glycoside from Eclipta prostrate with DGAT inhibitory activity.

PubMed

Meng, Xiao; Li, Ban-Ban; Lin, Xin; Jiang, Yi-Yu; Zhang, Le; Li, Hao-Ze; Cui, Long

2018-06-08

One new polyacetylene glycoside eprostrata Ⅰ (1), together with seven known compounds (2-8), were isolated from Eclipta prostrata. Their structures were elucidated on the basis of spectroscopic and physico-chemical analyses. All the isolates were evaluated inhibitory activity on DGAT in an in vitro assay. Compounds 1-8 were found to exhibit inhibitory activity of DGAT1 with IC 50 values ranging from 74.4 ± 1.3 to 101.1 ± 1.1 μM.

Expression and purification of membrane protein diacylglycerol acyltransferase

USDA-ARS?s Scientific Manuscript database

Diacylglycerol acyltransferases (DGATs) catalyze the last and rate-limiting step of triacylglycerol (TAG) biosynthesis in eukaryotic organisms. Plants and animals deficient in DGATs accumulate less TAG. Over-expression of DGATs increases TAG in seeds and other tissues. DGAT knockout mice are resista...

Differential expression of diacylglycerol acyltransferase (DGAT) genes in olive tissues.

PubMed

Giannoulia, K; Haralampidis, K; Poghosyan, Z; Murphy, D J; Hatzopoulos, P

2000-12-01

Fatty acids are accumulated in triacylglycerols (TAGs), in specialized organelles of seeds named oil bodies. The major site of TAG accumulation is detected in developing seed and mesocarp of certain species. We have isolated two cDNAs encoding DGAT enzymes from olives. The deduced polypeptides differ by 26 amino acids in size. However, they have high homology and almost identical hydropathy profiles. The DGAT gene is expressed in all tissues that synthesize TAGs. However, higher levels of DGAT transcripts have been detected in seed tissues of developing olive drupe. DGAT expression and mRNA accumulation in drupe tissues is developmentally regulated. Each DGAT transcript shows a distinct profile of accumulation. The existence of two different DGAT transcripts might reflect two different enzymes with discrete function and/or localization.

On the biogenesis of lipid bodies in ancient eukaryotes: synthesis of triacylglycerols by a Toxoplasma DGAT1-related enzyme.

PubMed

Quittnat, Friederike; Nishikawa, Yoshifumi; Stedman, Timothy T; Voelker, Dennis R; Choi, Jae-Yeon; Zahn, Matthew M; Murphy, Robert C; Barkley, Robert M; Pypaert, Marc; Joiner, Keith A; Coppens, Isabelle

2004-11-01

In mammalian cells, the main stored neutral lipids are triacylglycerol and cholesteryl esters, which are produced by two related enzymes, acyl-CoA:diacylglycerol acyltransferase (DGAT) and acyl-CoA:cholesterol acyltransferase (ACAT), respectively. Very little is known about the metabolism, intracellular storage and function of neutral lipids in many pathogenic lower eukaryotes. In this paper, we have characterized the activity of an important triacylglycerol synthetic enzyme in the protozoan Toxoplasma gondii. A full-length cDNA and gene encoding a T. gondii DGAT1-related enzyme were identified and designated TgDGAT1. The gene is composed of 15 exons and 14 introns, and encodes a protein with a predicted M(r) 63.5kDa, containing signature motifs characteristic of the DGAT1 family. The native protein migrates at 44kDa under reducing conditions. TgDGAT1 is an integral membrane protein localized to the parasite cortical and perinuclear endoplasmic reticulum, with the C-terminus oriented to the lumen of the organelle. When a Saccharomyces cerevisiae mutant strain lacking neutral lipid production is transformed with TgDGAT1 cDNA, a significant DGAT activity is reconstituted, resulting in triacylglycerol synthesis and biogenesis of cytosolic lipid inclusions, resembling lipid bodies in T. gondii. No production of steryl esters is observed upon TgDGAT1 expression in yeast. In contrast to human DGAT1 lacking fatty acid specificity, TgDGAT1 preferentially incorporates palmitate. Our results indicate that parasitic protozoa are also neutral lipid accumulators and illustrate the first example of the existence of a functional DGAT gene in an ancient eukaryote, demonstrating that diacylglycerol esterification is evolutionarily conserved.

Diacylglycerol Acyltransferase-1 (DGAT1) Inhibition Perturbs Postprandial Gut Hormone Release

PubMed Central

Lin, Hua V.; Chen, Dunlu; Shen, Zhu; Zhu, Lei; Ouyang, Xuesong; Vongs, Aurawan; Kan, Yanqing; Levorse, John M.; Kowalik, Edward J.; Szeto, Daphne M.; Yao, Xiaorui; Xiao, Jianying; Chen, Shirley; Liu, Jinqi; Garcia-Calvo, Marga; Shin, Myung K.; Pinto, Shirly

2013-01-01

Diacylglycerol acyltransferase-1 (DGAT1) is a potential therapeutic target for treatment of obesity and related metabolic diseases. However, the degree of DGAT1 inhibition required for metabolic benefits is unclear. Here we show that partial DGAT1 deficiency in mice suppressed postprandial triglyceridemia, led to elevations in glucagon-like peptide-1 (GLP-1) and peptide YY (PYY) only following meals with very high lipid content, and did not protect from diet-induced obesity. Maximal DGAT1 inhibition led to enhanced GLP-1 and PYY secretion following meals with physiologically relevant lipid content. Finally, combination of DGAT1 inhibition with dipeptidyl-peptidase-4 (DPP-4) inhibition led to further enhancements in active GLP-1 in mice and dogs. The current study suggests that targeting DGAT1 to enhance postprandial gut hormone secretion requires maximal inhibition, and suggests combination with DPP-4i as a potential strategy to develop DGAT1 inhibitors for treatment of metabolic diseases. PMID:23336002

MEK-ERK inhibition corrects the defect in VLDL assembly in HepG2 cells: potential role of ERK in VLDL-ApoB100 particle assembly.

PubMed

Tsai, Julie; Qiu, Wei; Kohen-Avramoglu, Rita; Adeli, Khosrow

2007-01-01

Hepatic VLDL assembly is defective in HepG2 cells, resulting in the secretion of immature triglyceride-poor LDL-sized apoB particles. We investigated the mechanisms underlying defective VLDL assembly in HepG2 and have obtained evidence implicating the MEK-ERK pathway. HepG2 cells exhibited considerably higher levels of the ERK1/2 mass and activity compared with primary hepatocytes. Inhibition of ERK1/2 using the MEK1/MEK2 inhibitor, U0126 (but not the inactive analogue) led to a significant increase in apoB secretion. In the presence of oleic acid, ERK1/2 inhibition caused a major shift in the lipoprotein distribution with a majority of particles secreted as VLDL, an effect independent of insulin. In contrast, overexpression of constitutively active MEK1 decreased apoB and large VLDL secretion. MEK1/2 inhibition significantly increased both cellular and microsomal TG mass, and mRNA levels for DGAT-1 and DGAT-2. In contrast to ERK, modulation of the PI3-K pathway or inhibition of the p38 MAP kinase, had no effect on lipoprotein density profile. Modulation of the MEK-ERK pathway in primary hamster hepatocytes led to changes in apoB secretion and altered the density profile of apoB-containing lipoproteins. Inhibition of the overactive ras-MEK-ERK pathway in HepG2 cells can correct the defect in VLDL assembly leading to the secretion of large, VLDL-sized particles, similar to primary hepatocytes, implicating the MEK-ERK cascade in VLDL assembly in the HepG2 model. Modulation of this pathway in primary hepatocytes also regulates apoB secretion and appears to alter the formation of VLDL-1 sized particles.

Expression of tung seed diacylglycerol acyltransferases (DGAT) in E. coli and yeast

USDA-ARS?s Scientific Manuscript database

Diacylglycerol acyltransferases (DGATs) catalyze the last step of triacylglycerol (TAG) biosynthesis in eukaryotic organisms. Plants and animals deficient in DGATs accumulate less TAG, resist obesity, and/or lack milk secretion. Over-expression of the DGATs increases TAG content in seeds and other t...

Hepatic stellate cells retain the capacity to synthesize retinyl esters and to store neutral lipids in small lipid droplets in the absence of LRAT.

PubMed

Ajat, Mokrish; Molenaar, Martijn; Brouwers, Jos F H M; Vaandrager, Arie B; Houweling, Martin; Helms, J Bernd

2017-02-01

Hepatic stellate cells (HSCs) play an important role in liver physiology and under healthy conditions they have a quiescent and lipid-storing phenotype. Upon liver injury, HSCs are activated and rapidly lose their retinyl ester-containing lipid droplets. To investigate the role of lecithin:retinol acyltransferase (LRAT) and acyl-CoA:diacylglycerol acyltransferase 1 (DGAT1) in retinyl ester synthesis and lipid droplet dynamics, we modified LC-MS/MS procedures by including multiple reaction monitoring allowing unambiguous identification and quantification of all major retinyl ester species. Quiescent primary HSCs contain predominantly retinyl palmitate. Exogenous fatty acids are a major determinant in the retinyl ester species synthesized by activated HSCs and LX-2 cells, indicating that HSCs shift their retinyl ester synthesizing capacity from LRAT to DGAT1 during activation. Quiescent LRAT -/- HSCs retain the capacity to synthesize retinyl esters and to store neutral lipids in lipid droplets ex vivo. The median lipid droplet size in LRAT -/- HSCs (1080nm) is significantly smaller than in wild type HSCs (1618nm). This is a consequence of an altered lipid droplet size distribution with 50.5±9.0% small (≤700nm) lipid droplets in LRAT -/- HSCs and 25.6±1.4% large (1400-2100nm) lipid droplets in wild type HSC cells. Upon prolonged (24h) incubation, the amounts of small (≤700nm) lipid droplets strongly increased both in wild type and in LRAT -/- HSCs, indicating a dynamic behavior in both cell types. The absence of retinyl esters and reduced number of lipid droplets in LRAT-deficient HSCs in vivo will be discussed. Copyright © 2016 Elsevier B.V. All rights reserved.

Expression and purification of recombinant tung tree diacylglycerol acyltransferase 2

USDA-ARS?s Scientific Manuscript database

Diacylglycerol acyltransferases (DGATs) are responsible for the last step of triacylglycerol (TAG) biosynthesis in eukaryotic organisms. Different forms of DGATs have nonredundant functions in TAG biosynthesis in species such as tung tree (Vernicia fordii), which contains approximately 80% high-valu...

Liver fat reduction with niacin is influenced by DGAT-2 polymorphisms in hypertriglyceridemic patients

PubMed Central

Hu, Miao; Chu, Winnie Chiu Wing; Yamashita, Shizuya; Yeung, David Ka Wai; Shi, Lin; Wang, Defeng; Masuda, Daisaku; Yang, Yaling; Tomlinson, Brian

2012-01-01

Niacin reduces plasma triglycerides, but it may increase free fatty acids and insulin resistance during long-term treatment. We examined the effect of extended-release niacin on liver fat content in Chinese patients with dyslipidemia and whether the common diacylglycerol acyltransferase-2 (DGAT2) polymorphisms influenced this effect. The 39 patients (baseline liver fat content: 12.8 ± 7.6%, triglycerides: 3.30 ± 1.67 mmol/l) were treated with niacin, gradually increasing the dose to 2 g/day for a total of 23 weeks. The liver fat content and visceral/subcutaneous fat was measured before and after treatment. Subjects were genotyped for the DGAT2 rs3060 and rs101899116 polymorphisms. There were significant (P < 0.001) reductions in plasma triglycerides (−34.9 ± 37.6%), liver fat content (−47.2 ± 32.8%), and visceral fat (−6.3 ± 15.8%, P < 0.05) after niacin treatment. Mean body weight decreased by 1.46 ± 2.7% (1.17 ± 2.44 kg, P < 0.001) during the study, but liver fat changes remained significant after adjustment for age, gender, and body weight changes [mean absolute change (95% CI): −6.1% (−8.0, −4.3), P < 0.001]. The DGAT2 variant alleles were associated with a smaller reduction in liver fat content in response to niacin after adjustment for other covariates (P < 0.01). These findings suggest that niacin treatment may reduce liver fat content in Chinese patients with dyslipidemia and that the mechanism may involve inhibition of DGAT2. However, the findings might have been confounded by the small but significant reductions in body weight during the study. Future large randomized controlled trials are needed to verify these findings. PMID:22315393

Liver fat reduction with niacin is influenced by DGAT-2 polymorphisms in hypertriglyceridemic patients.

PubMed

Hu, Miao; Chu, Winnie Chiu Wing; Yamashita, Shizuya; Yeung, David Ka Wai; Shi, Lin; Wang, Defeng; Masuda, Daisaku; Yang, Yaling; Tomlinson, Brian

2012-04-01

Niacin reduces plasma triglycerides, but it may increase free fatty acids and insulin resistance during long-term treatment. We examined the effect of extended-release niacin on liver fat content in Chinese patients with dyslipidemia and whether the common diacylglycerol acyltransferase-2 (DGAT2) polymorphisms influenced this effect. The 39 patients (baseline liver fat content: 12.8 ± 7.6%, triglycerides: 3.30 ± 1.67 mmol/l) were treated with niacin, gradually increasing the dose to 2 g/day for a total of 23 weeks. The liver fat content and visceral/subcutaneous fat was measured before and after treatment. Subjects were genotyped for the DGAT2 rs3060 and rs101899116 polymorphisms. There were significant (P < 0.001) reductions in plasma triglycerides (-34.9 ± 37.6%), liver fat content (-47.2 ± 32.8%), and visceral fat (-6.3 ± 15.8%, P < 0.05) after niacin treatment. Mean body weight decreased by 1.46 ± 2.7% (1.17 ± 2.44 kg, P < 0.001) during the study, but liver fat changes remained significant after adjustment for age, gender, and body weight changes [mean absolute change (95% CI): -6.1% (-8.0, -4.3), P < 0.001]. The DGAT2 variant alleles were associated with a smaller reduction in liver fat content in response to niacin after adjustment for other covariates (P < 0.01). These findings suggest that niacin treatment may reduce liver fat content in Chinese patients with dyslipidemia and that the mechanism may involve inhibition of DGAT2. However, the findings might have been confounded by the small but significant reductions in body weight during the study. Future large randomized controlled trials are needed to verify these findings.

Betaine attenuates chronic alcohol‑induced fatty liver by broadly regulating hepatic lipid metabolism.

PubMed

Yang, Wenjuan; Huang, Luming; Gao, Jinhang; Wen, Shilei; Tai, Yang; Chen, Meng; Huang, Zhiyin; Liu, Rui; Tang, Chengwei; Li, Jing

2017-10-01

Betaine has previously been demonstrated to protect the liver against alcohol‑induced fat accumulation. However, the mechanism through which betaine affects alcohol‑induced hepatic lipid metabolic disorders has not been extensively studied. The present study aimed to investigate the effect of betaine on alcoholic simple fatty liver and hepatic lipid metabolism disorders. A total of 36 rats were randomly divided into control, ethanol and ethanol + betaine groups. Liver function, morphological alterations, lipid content and tumor necrosis factor (TNF)‑α levels were determined. Hepatic expression levels of diacylglycerol acyltransferase (DGAT) 1, DGAT2, sterol regulatory element binding protein (SREBP)‑1c, SREBP‑2, fatty acid synthase (FAS), 3‑hydroxy‑3‑methyl‑glutaryl (HMG)‑CoA reductase, peroxisome proliferator-activated receptor λ coactivator (PGC)‑1α, adiponectin receptor (AdipoR) 1 and AdipoR2 were quantified. Serum and adipose tissue adiponectin levels were assessed using an enzyme‑linked immunoassay. The results demonstrated that alcohol‑induced ultramicrostructural alterations in hepatocytes, including the presence of lipid droplets and swollen mitochondria, were attenuated by betaine. Hepatic triglyceride, free fatty acid, total cholesterol and cholesterol ester contents and the expression of DGAT1, DGAT2, SREBP‑1c, SREBP‑2, FAS and HMG‑CoA reductase were increased following ethanol consumption, however were maintained at control levels following betaine supplementation. Alcohol‑induced decreases in hepatic PGC‑1α mRNA levels and serum and adipose tissue adiponectin concentrations were prevented by betaine. The downregulation of hepatic AdipoR1 which resulted from alcohol exposure was partially attenuated by betaine. No significant differences in liver function, TNF‑α, phospholipid and AdipoR2 levels were observed among the control, ethanol and ethanol + betaine groups. Overall, these results indicated that betaine attenuated the alcoholic simple fatty liver by improving hepatic lipid metabolism via suppression of DGAT1, DGAT2, SREBP‑1c, FAS, SREBP‑2 and HMG‑CoA reductase and upregulation of PGC‑1α.

Beyond triglyceride synthesis: the dynamic functional roles of MGAT and DGAT enzymes in energy metabolism.

PubMed

Shi, Yuguang; Cheng, Dong

2009-07-01

Monoacyglycerol acyltransferases (MGATs) and diacylglycerol acyltransferases (DGATs) catalyze two consecutive steps of enzyme reactions in the synthesis of triacylglycerols (TAGs). The metabolic complexity of TAG synthesis is reflected by the presence of multiple isoforms of MGAT and DGAT enzymes that differ in catalytic properties, subcellular localization, tissue distribution, and physiological functions. MGAT and DGAT enzymes play fundamental roles in the metabolism of monoacylglycerol (MAG), diacylglycerol (DAG), and triacylglycerol (TAG) that are involved in many aspects of physiological functions, such as intestinal fat absorption, lipoprotein assembly, adipose tissue formation, signal transduction, satiety, and lactation. The recent progress in the phenotypic characterization of mice deficient in MGAT and DGAT enzymes and the development of chemical inhibitors have revealed important roles of these enzymes in the regulation of energy homeostasis and insulin sensitivity. Consequently, selective inhibition of MGAT or DGAT enzymes by synthetic compounds may provide novel treatment for obesity and its related metabolic complications.

Biogenesis of ER subdomains containing DGAT2, an enzyme involved in industrial oil biosynthesis

USDA-ARS?s Scientific Manuscript database

Diacylglycerol acyltransferases (DGATs) are enzymes that catalyze the committed step in triacylglycerol (TAG) biosynthesis by transferring a fatty acyl group from the acyl-CoA pool to the sn-3 position of diacylglycerol. The substrate specificity and overall activity of these enzymes play a key role...

DGAT1 K232A polymorphism in Brazilian cattle breeds.

PubMed

Lacorte, G A; Machado, M A; Martinez, M L; Campos, A L; Maciel, R P; Verneque, R S; Teodoro, R L; Peixoto, M G C D; Carvalho, M R S; Fonseca, C G

2006-08-31

Recent reports identified DGAT1 (EC 2.3.1.20) harboring a lysine to alanine substitution (K232A) as a candidate gene with a strong effect on milk production traits. Our objective was to estimate the frequency of the DGAT1 K232A polymorphism in the main Zebu and Taurine breeds in Brazil as well as in Zebu x Taurine crossbreds as a potential QTL for marker-assisted selection. Samples of 331 animals from the main Brazilian breeds, Nellore, Guzerat, Red Sindhi, Gyr, Holstein, and Gyr x Holstein F1 were genotyped for DGAT1 K232A polymorphism (A and K alleles) using the PCR-RFLP technique. The highest frequency of the A allele was found in the Holstein sample (73%) followed by Gyr x Holstein F1 (39%). Gyr and Red Sindhi showed low frequencies of A alleles (4 and 2.5%, respectively). The A allele was not found in the Nellore and Guzerat samples. Our results could be used to guide association studies between this locus and milk traits in these breeds.

Identification of a botanical inhibitor of intestinal diacylglyceride acyltransferase 1 activity via in vitro screening and a parallel, randomized, blinded, placebo-controlled clinical trial.

PubMed

Velliquette, Rodney A; Grann, Kerry; Missler, Stephen R; Patterson, Jennifer; Hu, Chun; Gellenbeck, Kevin W; Scholten, Jeffrey D; Randolph, R Keith

2015-01-01

Diacylglyceride acyltransferase 1 (DGAT1) is the enzyme that adds the final fatty acid on to a diacylglyceride during triglyceride (TG) synthesis. DGAT1 plays a key role in the repackaging of dietary TG into circulating TG rich chylomicrons. A growing amount of research has indicated that an exaggerated postprandial circulating TG level is a risk indicator for cardiovascular and metabolic disorders. The aim of this research was to identify a botanical extract that inhibits intestinal DGAT1 activity and attenuates postprandial hypertriglyceridemia in overweight and obese humans. Twenty individual phytochemicals and an internal proprietary botanical extract library were screened with a primary cell-free DGAT1 enzyme assay that contained dioleoyl glycerol and palmitoleoyl Coenzyme A as substrates plus human intestinal microsomes as the DGAT1 enzyme source. Botanical extracts with IC50 values < 100 μg/mL were evaluated in a cellular DGAT1 assay. The cellular DGAT1 assay comprised the analysis of (14)C labeled TG synthesis in cells incubated with (14)C-glycerol and 0.3 mM oleic acid. Lead botanical extracts were then evaluated in a parallel, double-blind, placebo-controlled clinical trial. Ninety healthy, overweight and obese participants were randomized to receive 2 g daily of placebo or individual botanical extracts (the investigational product) for seven days. Serum TG levels were measured before and after consuming a high fat meal (HFM) challenge (0.354 L drink/shake; 77 g fat, 25 g carbohydrate and 9 g protein) as a marker of intestinal DGAT1 enzyme activity. Phenolic acids (i.e., gallic acid) and polyphenols (i.e., cyanidin) abundantly found in nature appeared to inhibit DGAT1 enzyme activity in vitro. Four polyphenolic rich botanical extracts were identified from in vitro evaluation in both cell-free and cellular model systems: apple peel extract (APE), grape extract (GE), red raspberry leaf extract (RLE) and apricot/nectarine extract (ANE) (IC50 = 1.4, 5.6, and 10.4 and 3.4 μg/mL, respectively). In the seven day clinical trial, compared to placebo, only GE significantly reduced the baseline subtracted change in serum TG AUC following consumption of the HFM (AUC = 281 ± 37 vs. 181 ± 30 mg/dL*h, respectively; P = 0.021). Chromatographic characterization of the GE revealed a large number of closely eluting components containing proanthocyanidins, catechins, anthocyanins and their secondary metabolites that corresponded with the observed DGAT1 enzyme inhibition in the cell-free model. These data suggest that a dietary GE has the potential to attenuate postprandial hypertriglyceridemia in part by the inhibition of intestinal DGAT1 enzyme activity without intolerable side effects. This trial was registered with ClinicalTrials.gov NCT02333461.

Beyond triglyceride synthesis: the dynamic functional roles of MGAT and DGAT enzymes in energy metabolism

PubMed Central

Shi, Yuguang; Cheng, Dong

2009-01-01

Monoacyglycerol acyltransferases (MGATs) and diacylglycerol acyltransferases (DGATs) catalyze two consecutive steps of enzyme reactions in the synthesis of triacylglycerols (TAGs). The metabolic complexity of TAG synthesis is reflected by the presence of multiple isoforms of MGAT and DGAT enzymes that differ in catalytic properties, subcellular localization, tissue distribution, and physiological functions. MGAT and DGAT enzymes play fundamental roles in the metabolism of monoacylglycerol (MAG), diacylglycerol (DAG), and triacylglycerol (TAG) that are involved in many aspects of physiological functions, such as intestinal fat absorption, lipoprotein assembly, adipose tissue formation, signal transduction, satiety, and lactation. The recent progress in the phenotypic characterization of mice deficient in MGAT and DGAT enzymes and the development of chemical inhibitors have revealed important roles of these enzymes in the regulation of energy homeostasis and insulin sensitivity. Consequently, selective inhibition of MGAT or DGAT enzymes by synthetic compounds may provide novel treatment for obesity and its related metabolic complications. PMID:19116371

Discovery of Tetralones as Potent and Selective Inhibitors of Acyl-CoA:Diacylglycerol Acyltransferase 1.

PubMed

Cheung, Mui; Tangirala, Raghuram S; Bethi, Sridhar R; Joshi, Hemant V; Ariazi, Jennifer L; Tirunagaru, Vijaya G; Kumar, Sanjay

2018-02-08

Acyl-CoA:diacylglycerol acyltransferase 1 (DGAT1) plays an important role in triglyceride synthesis and is a target of interest for the treatment of metabolic disorders. Herein we describe the structure-activity relationship of a novel tetralone series of DGAT1 inhibitors and our strategies for overcoming genotoxic liability of the anilines embedded in the chemical structures, leading to the discovery of a candidate compound, ( S )-2-(6-(5-(3-(3,4-difluorophenyl)ureido)pyrazin-2-yl)-1-oxo-2-(2,2,2-trifluoroethyl)-1,2,3,4-tetrahydronaphthalen-2-yl)acetic acid (GSK2973980A, 26d ). Compound 26d is a potent and selective DGAT1 inhibitor with excellent DMPK profiles and in vivo efficacy in a postprandial lipid excursion model in mice. Based on the overall biological and developability profiles and acceptable safety profiles in the 7-day toxicity studies in rats and dogs, compound 26d was selected as a candidate compound for further development in the treatment of metabolic disorders.

Structure-function analysis of diacylglycerol acyltransferase sequences for metabolic engineering and drug discovery

USDA-ARS?s Scientific Manuscript database

Diacylglycerol acyltransferase families (DGATs) catalyze the final and rate-limiting step of triacylglycerol (TAG) biosynthesis in eukaryotic organisms. DGAT knockout mice are resistant to diet-induced obesity and lack milk secretion. Over-expression of DGATs increases TAG in plants. Therefore, unde...

Congenital protein losing enteropathy: an inborn error of lipid metabolism due to DGAT1 mutations.

PubMed

Stephen, Joshi; Vilboux, Thierry; Haberman, Yael; Pri-Chen, Hadass; Pode-Shakked, Ben; Mazaheri, Sina; Marek-Yagel, Dina; Barel, Ortal; Di Segni, Ayelet; Eyal, Eran; Hout-Siloni, Goni; Lahad, Avishay; Shalem, Tzippora; Rechavi, Gideon; Malicdan, May Christine V; Weiss, Batia; Gahl, William A; Anikster, Yair

2016-08-01

Protein-losing enteropathy (PLE) is a clinical disorder of protein loss from the gastrointestinal system that results in hypoproteinemia and malnutrition. This condition is associated with a wide range of gastrointestinal disorders. Recently, a unique syndrome of congenital PLE associated with biallelic mutations in the DGAT1 gene has been reported in a single family. We hypothesize that mutations in this gene are responsible for undiagnosed cases of PLE in infancy. Here we investigated three children in two families presenting with severe diarrhea, hypoalbuminemia and PLE, using clinical studies, homozygosity mapping, and exome sequencing. In one family, homozygosity mapping using SNP arrays revealed the DGAT1 gene as the best candidate gene for the proband. Sequencing of all the exons including flanking regions and promoter regions of the gene identified a novel homozygous missense variant, p.(Leu295Pro), in the highly conserved membrane-bound O-acyl transferase (MBOAT) domain of the DGAT1 protein. Expression studies verified reduced amounts of DGAT1 in patient fibroblasts. In a second family, exome sequencing identified a previously reported splice site mutation in intron 8. These cases of DGAT1 deficiency extend the molecular and phenotypic spectrum of PLE, suggesting a re-evaluation of the use of DGAT1 inhibitors for metabolic disorders including obesity and diabetes.

Reducing Isozyme Competition Increases Target Fatty Acid Accumulation in Seed Triacylglycerols of Transgenic Arabidopsis1[OPEN

PubMed Central

van Erp, Harrie; Shockey, Jay; Zhang, Meng; Adhikari, Neil D.; Browse, John

2015-01-01

One goal of green chemistry is the production of industrially useful fatty acids (FAs) in crop plants. We focus on hydroxy fatty acids (HFAs) and conjugated polyenoic FAs (α-eleostearic acids [ESAs]) using Arabidopsis (Arabidopsis thaliana) as a model. These FAs are found naturally in seed oils of castor (Ricinus communis) and tung tree (Vernicia fordii), respectively, and used for the production of lubricants, nylon, and paints. Transgenic oils typically contain less target FA than that produced in the source species. We hypothesized that competition between endogenous and transgenic isozymes for substrates limits accumulation of unique FAs in Arabidopsis seeds. This hypothesis was tested by introducing a mutation in Arabidopsis diacylglycerol acyltransferase1 (AtDGAT1) in a line expressing castor FA hydroxylase and acyl-Coenzyme A:RcDGAT2 in its seeds. This led to a 17% increase in the proportion of HFA in seed oil. Expression of castor phospholipid:diacylglycerol acyltransferase 1A in this line increased the proportion of HFA by an additional 12%. To determine if our observations are more widely applicable, we investigated if isozyme competition influenced production of ESA. Expression of tung tree FA conjugase/desaturase in Arabidopsis produced approximately 7.5% ESA in seed lipids. Coexpression of VfDGAT2 increased ESA levels to approximately 11%. Overexpression of VfDGAT2 combined with suppression of AtDGAT1 increased ESA accumulation to 14% to 15%. Our results indicate that isozyme competition is a limiting factor in the engineering of unusual FAs in heterologous plant systems and that reduction of competition through mutation and RNA suppression may be a useful component of seed metabolic engineering strategies. PMID:25739701

Genes involved in the establishment of hepatic steatosis in Muscovy, Pekin and mule ducks.

PubMed

Tavernier, Annabelle; Davail, Stéphane; Ricaud, Karine; Bernadet, Marie-Dominique; Gontier, Karine

2017-01-01

Our main objectives were to determine the genes involved in the establishment of hepatic steatosis in three genotypes of palmipeds. To respond to this question, we have compared Muscovy ducks, Pekin ducks and their crossbreed the mule duck fed ad libitum or overfed. We have shown a hepatic overexpression of fatty acid synthase (FAS) and di-acyl glycerol acyl transferase 2 (DGAT2) in overfed individuals, where DGAT2 seemed to be more regulated. This increase in lipogenesis genes is associated with a decrease of lipoprotein formation in Muscovy and mule ducks, especially apolipoprotein B (ApoB) and Microsomal Triglyceride Transfer Protein (MTTP), leading to lipid accumulation in liver. In Pekin ducks, MTTP expression is upregulated suggesting a better hepatic lipids exportation. Regarding lipids re-uptake, fatty acid-binding protein 4 and very-low-density-lipoprotein receptor are overexpressed in liver of mule ducks at the end of the overfeeding period. This phenomenon puts light on a mechanism unknown until today. In fact, mule can incorporate more lipids in liver than the two other genotypes leading to an intensified hepatic steatosis. To conclude, our results confirmed the genotype variability to overfeeding. Furthermore, similar observations are already described in non-alcoholic fatty liver disease in human, and ask if ducks could be an animal model to study hepatic triglyceride accumulation.

Novel SNPs and INDEL polymorphisms in the 3'UTR of DGAT1 gene: in silico analyses and a possible association.

PubMed

Rosse, Izinara da Cruz; Steinberg, Raphael da Silva; Coimbra, Roney Santos; Peixoto, Maria Gabriela Campolina Diniz; Verneque, Rui Silva; Machado, Marco Antonio; Fonseca, Cleusa Graça; Carvalho, Maria Raquel Santos

2014-07-01

Diacylglycerol-O-acyltransferase (DGAT1) gene encodes the rate-limiting enzyme of triglyceride synthesis. A polymorphism in this gene, DGAT1 K232A, has been associated with milk production and composition in taurine breeds. However, this polymorphism is not a good tool for ascertaining the effects of this QTL in Bos indicus (Zebu), since the frequency of the DGAT1 232A allele is too low in these breeds. We sequenced the 3'-untranslated region of DGAT1 gene in a sample of bulls of the breeds Guzerá (Bos indicus) and Holstein (Bos taurus) and, using in silico analysis, we searched for genetic variation, evolutionary conservation, regulatory elements, and possible substitution effects. Six single nucleotide (SNPs) and one insertion-deletion (INDEL) polymorphisms were found in the Guzerá bulls. Additionally, we developed a preliminary association study, using this INDEL polymorphism as a genetic marker. A significant association was detected (P ≤ 0.05) between the INDEL (DGAT1 3'UTR INDEL) and the breeding values (BV) for protein, fat, and milk yields over a 305-day lactation period. The DGAT1 3' UTR INDEL genotype I/I (I, for insertion) was associated with lower BVs (-38.77 kg for milk, -1.86 kg for fat, and -1.48 kg for protein yields), when compared to the genotype I/D (D, for deletion). I/D genotype was lower D/D genotype (-34.98 kg milk, -1.73 kg fat, and -1.09 kg protein yields). This study reports the first polymorphism of DGAT1 3'UTR in the Guzerá breed, as well as its association with BV for milk protein, fat, and milk yields.

Dominance and parent-of-origin effects of coding and non-coding alleles at the acylCoA-diacylglycerol-acyltransferase (DGAT1) gene on milk production traits in German Holstein cows

PubMed Central

Kuehn, Christa; Edel, Christian; Weikard, Rosemarie; Thaller, Georg

2007-01-01

Background Substantial gene substitution effects on milk production traits have formerly been reported for alleles at the K232A and the promoter VNTR loci in the bovine acylCoA-diacylglycerol-acyltransferase 1 (DGAT1) gene by using data sets including sires with accumulated phenotypic observations of daughters (breeding values, daughter yield deviations). However, these data sets prevented analyses with respect to dominance or parent-of-origin effects, although an increasing number of reports in the literature outlined the relevance of non-additive gene effects on quantitative traits. Results Based on a data set comprising German Holstein cows with direct trait measurements, we first confirmed the previously reported association of DGAT1 promoter VNTR alleles with milk production traits. We detected a dominant mode of effects for the DGAT1 K232A and promoter VNTR alleles. Namely, the contrasts between the effects of heterozygous individuals at the DGAT1 loci differed significantly from the midpoint between the effects for the two homozygous genotypes for several milk production traits, thus indicating the presence of dominance. Furthermore, we identified differences in the magnitude of effects between paternally and maternally inherited DGAT1 promoter VNTR – K232A haplotypes indicating parent-of-origin effects on milk production traits. Conclusion Non-additive effects like those identified at the bovine DGAT1 locus have to be accounted for in more specific QTL detection models as well as in marker assisted selection schemes. The DGAT1 alleles in cattle will be a useful model for further investigations on the biological background of non-additive effects in mammals due to the magnitude and consistency of their effects on milk production traits. PMID:17892573

Discovery of an Orally Bioavailable Benzimidazole Diacylglycerol Acyltransferase 1 (DGAT1) Inhibitor That Suppresses Body Weight Gain in Diet-Induced Obese Dogs and Postprandial Triglycerides in Humans.

PubMed

Nakajima, Katsumasa; Chatelain, Ricardo; Clairmont, Kevin B; Commerford, Renee; Coppola, Gary M; Daniels, Thomas; Forster, Cornelia J; Gilmore, Thomas A; Gong, Yongjin; Jain, Monish; Kanter, Aaron; Kwak, Youngshin; Li, Jingzhou; Meyers, Charles D; Neubert, Alan D; Szklennik, Paul; Tedesco, Vivienne; Thompson, James; Truong, David; Yang, Qing; Hubbard, Brian K; Serrano-Wu, Michael H

2017-06-08

Modification of a gut restricted class of benzimidazole DGAT1 inhibitor 1 led to 9 with good oral bioavailability. The key structural changes to 1 include bioisosteric replacement of the amide with oxadiazole and α,α-dimethylation of the carboxylic acid, improving DGAT1 potency and gut permeability. Since DGAT1 is expressed in the small intestine, both 1 and 9 can suppress postprandial triglycerides during acute oral lipid challenges in rats and dogs. Interestingly, only 9 was found to be effective in suppressing body weight gain relative to control in a diet-induced obese dog model, suggesting the importance of systemic inhibition of DGAT1 for body weight control. 9 has advanced to clinical investigation and successfully suppressed postprandial triglycerides during an acute meal challenge in humans.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zienkiewicz, Krzysztof; Zienkiewicz, Agnieszka; Poliner, Eric

Photosynthetic microalgae are considered a viable and sustainable resource for biofuel feedstocks, because they can produce higher biomass per land area than plants and can be grown on non-arable land. Among many microalgae considered for biofuel production, Nannochloropsis oceanica (CCMP1779) is particularly promising, because following nutrient deprivation it produces very high amounts of triacylglycerols (TAG). The committed step in TAG synthesis is catalyzed by acyl-CoA:diacylglycerol acyltransferase (DGAT). Remarkably, a total of 13 putative DGAT-encoding genes have been previously identified in CCMP1779 but most have not yet been studied in detail. We chose six out of 12 type-2 DGAT-encoding genes (NoDGTT1-NoDGTT6),more » based on their expression profile, for their possible role in TAG biosynthesis and the respective cDNAs were expressed in a TAG synthesis-deficient mutant of yeast. Yeast expressing NoDGTT5 accumulated TAG to the highest level. Over-expression of NoDGTT5 in CCMP1779 grown in N-replete medium resulted in levels of TAG normally observed only after N deprivation. Reduced growth rates accompanied NoDGTT5 over-expression in CCMP1779. Constitutive expression of NoDGTT5 in Arabidopsis thaliana was accompanied by increased TAG content in seeds and leaves. A broad substrate specificity for NoDGTT5 was revealed, with preference for unsaturated acyl groups. Furthermore, NoDGTT5 was able to successfully rescue the Arabidopsis tag1-1 mutant by restoring the TAG content in seeds. Taken together, these results identified NoDGTT5 as the most promising gene for the engineering of TAG synthesis in multiple hosts among the 13 DGAT-encoding genes of N. oceanica CCMP1779. Consequently, this study demonstrates the potential of NoDGTT5 as a tool for enhancing the energy density in biomass by increasing TAG content in transgenic crops used for biofuel production.« less

Nannochloropsis, a rich source of diacylglycerol acyltransferases for engineering of triacylglycerol content in different hosts

DOE PAGES

Zienkiewicz, Krzysztof; Zienkiewicz, Agnieszka; Poliner, Eric; ...

2017-01-03

Photosynthetic microalgae are considered a viable and sustainable resource for biofuel feedstocks, because they can produce higher biomass per land area than plants and can be grown on non-arable land. Among many microalgae considered for biofuel production, Nannochloropsis oceanica (CCMP1779) is particularly promising, because following nutrient deprivation it produces very high amounts of triacylglycerols (TAG). The committed step in TAG synthesis is catalyzed by acyl-CoA:diacylglycerol acyltransferase (DGAT). Remarkably, a total of 13 putative DGAT-encoding genes have been previously identified in CCMP1779 but most have not yet been studied in detail. We chose six out of 12 type-2 DGAT-encoding genes (NoDGTT1-NoDGTT6),more » based on their expression profile, for their possible role in TAG biosynthesis and the respective cDNAs were expressed in a TAG synthesis-deficient mutant of yeast. Yeast expressing NoDGTT5 accumulated TAG to the highest level. Over-expression of NoDGTT5 in CCMP1779 grown in N-replete medium resulted in levels of TAG normally observed only after N deprivation. Reduced growth rates accompanied NoDGTT5 over-expression in CCMP1779. Constitutive expression of NoDGTT5 in Arabidopsis thaliana was accompanied by increased TAG content in seeds and leaves. A broad substrate specificity for NoDGTT5 was revealed, with preference for unsaturated acyl groups. Furthermore, NoDGTT5 was able to successfully rescue the Arabidopsis tag1-1 mutant by restoring the TAG content in seeds. Taken together, these results identified NoDGTT5 as the most promising gene for the engineering of TAG synthesis in multiple hosts among the 13 DGAT-encoding genes of N. oceanica CCMP1779. Consequently, this study demonstrates the potential of NoDGTT5 as a tool for enhancing the energy density in biomass by increasing TAG content in transgenic crops used for biofuel production.« less

Two Predicted Transmembrane Domains Exclude Very Long Chain Fatty acyl-CoAs from the Active Site of Mouse Wax Synthase

PubMed Central

Kawelke, Steffen; Feussner, Ivo

2015-01-01

Wax esters are used as coatings or storage lipids in all kingdoms of life. They are synthesized from a fatty alcohol and an acyl-CoA by wax synthases. In order to get insights into the structure-function relationships of a wax synthase from Mus musculus, a domain swap experiment between the mouse acyl-CoA:wax alcohol acyltransferase (AWAT2) and the homologous mouse acyl-CoA:diacylglycerol O-acyltransferase 2 (DGAT2) was performed. This showed that the substrate specificity of AWAT2 is partially determined by two predicted transmembrane domains near the amino terminus of AWAT2. Upon exchange of the two domains for the respective part of DGAT2, the resulting chimeric enzyme was capable of incorporating up to 20% of very long acyl chains in the wax esters upon expression in S. cerevisiae strain H1246. The amount of very long acyl chains in wax esters synthesized by wild type AWAT2 was negligible. The effect was narrowed down to a single amino acid position within one of the predicted membrane domains, the AWAT2 N36R variant. Taken together, we provide first evidence that two predicted transmembrane domains in AWAT2 are involved in determining its acyl chain length specificity. PMID:26714272

New Polyacetylenes, DGAT inhibitors from the roots of Panax ginseng.

PubMed

Lee, Seung Woong; Kim, Koanhoi; Rho, Mun-Chual; Chung, Mi Yeon; Kim, Young Ho; Lee, Sangku; Lee, Hyun Sun; Kim, Young Kook

2004-03-01

The petroleum ether extract of Panax ginseng showed a significant inhibition of the diacylglycerol acyltransferase (DGAT) enzyme from rat liver microsomes. Bioactivity-guided fractionation led to the isolation of two new polyacetylenic compounds, (9 R,10 S)-epoxyheptadecan-4,6-diyn-3-one ( 1) and 1-methoxy-(9 R,10 S)-epoxyheptadecan-4,6-diyn-3-one ( 2). Their chemical structures were elucidated on the basis of spectroscopic evidence and asymmetric synthesis. IC50 values of 9 microg/mL ( 1) and 32 microg/mL ( 2) were obtained.

Mangiferin treatment inhibits hepatic expression of acyl-coenzyme A:diacylglycerol acyltransferase-2 in fructose-fed spontaneously hypertensive rats: a link to amelioration of fatty liver

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xing, Xiaomang; Li, Danyang; Chen, Dilong

Mangiferin, a xanthone glucoside, and its associated traditional herbs have been demonstrated to improve abnormalities of lipid metabolism. However, its underlying mechanisms remain largely unclear. This study investigated the anti-steatotic effect of mangiferin in fructose-fed spontaneously hypertensive rat (SHR)s that have a mutation in sterol regulatory element binding protein (SREBP)-1. The results showed that co-administration of mangiferin (15 mg/kg, once daily, by oral gavage) over 7 weeks dramatically diminished fructose-induced increases in hepatic triglyceride content and Oil Red O-stained area in SHRs. However, blood pressure, fructose and chow intakes, white adipose tissue weight and metabolic parameters (plasma concentrations of glucose,more » insulin, triglyceride, total cholesterol and non-esterified fatty acids) were unaffected by mangiferin treatment. Mechanistically, mangiferin treatment suppressed acyl-coenzyme A:diacylglycerol acyltransferase (DGAT)-2 expression at the mRNA and protein levels in the liver. In contrast, mangiferin treatment was without effect on hepatic mRNA and/or protein expression of SREBP-1/1c, carbohydrate response element binding protein, liver pyruvate kinase, fatty acid synthase, acetyl-CoA carboxylase-1, stearoyl-CoA desaturase-1, DGAT-1, monoacyglycerol acyltransferase-2, microsomal triglyceride transfer protein, peroxisome proliferator-activated receptor-alpha, carnitine palmitoyltransferase-1 and acyl-CoA oxidase. Collectively, our results suggest that mangiferin treatment ameliorates fatty liver in fructose-fed SHRs by inhibiting hepatic DGAT-2 that catalyzes the final step in triglyceride biosynthesis. The anti-steatotic effect of mangiferin may occur independently of the hepatic signals associated with de novo fatty acid synthesis and oxidation. - Highlights: • We investigated the anti-steatotic effect of mangiferin (MA) in fructose-fed SHR. • MA (15 mg/kg/day for 7 weeks) ameliorated fructose-induced fatty liver in SHR. • MA inhibited hepatic DGAT2 expression at the mRNA and protein levels. • MA did not affect expression of the genes responsible for fatty acid synthesis. • MA ameliorates fructose-induced fatty liver by inhibiting hepatic DGAT2 in rats.« less

Discovery and Optimization of Imidazopyridine-Based Inhibitors of Diacylglycerol Acyltransferase 2 (DGAT2).

PubMed

Futatsugi, Kentaro; Kung, Daniel W; Orr, Suvi T M; Cabral, Shawn; Hepworth, David; Aspnes, Gary; Bader, Scott; Bian, Jianwei; Boehm, Markus; Carpino, Philip A; Coffey, Steven B; Dowling, Matthew S; Herr, Michael; Jiao, Wenhua; Lavergne, Sophie Y; Li, Qifang; Clark, Ronald W; Erion, Derek M; Kou, Kou; Lee, Kyuha; Pabst, Brandon A; Perez, Sylvie M; Purkal, Julie; Jorgensen, Csilla C; Goosen, Theunis C; Gosset, James R; Niosi, Mark; Pettersen, John C; Pfefferkorn, Jeffrey A; Ahn, Kay; Goodwin, Bryan

2015-09-24

The medicinal chemistry and preclinical biology of imidazopyridine-based inhibitors of diacylglycerol acyltransferase 2 (DGAT2) is described. A screening hit 1 with low lipophilic efficiency (LipE) was optimized through two key structural modifications: (1) identification of the pyrrolidine amide group for a significant LipE improvement, and (2) insertion of a sp(3)-hybridized carbon center in the core of the molecule for simultaneous improvement of N-glucuronidation metabolic liability and off-target pharmacology. The preclinical candidate 9 (PF-06424439) demonstrated excellent ADMET properties and decreased circulating and hepatic lipids when orally administered to dyslipidemic rodent models.

Positive regulation of prostate cancer cell growth by lipid droplet forming and processing enzymes DGAT1 and ABHD5.

PubMed

Mitra, Ranjana; Le, Thuc T; Gorjala, Priyatham; Goodman, Oscar B

2017-09-06

Neoplastic cells proliferate rapidly and obtain requisite building blocks by reprogramming metabolic pathways that favor growth. Previously, we observed that prostate cancer cells uptake and store lipids in the form of lipid droplets, providing building blocks for membrane synthesis, to facilitate proliferation and growth. Mechanisms of lipid uptake, lipid droplet dynamics and their contribution to cancer growth have yet to be defined. This work is focused on elucidating the prostate cancer-specific modifications in lipid storage pathways so that these modified gene products can be identified and therapeutically targeted. To identify genes that promote lipid droplet formation and storage, the expression profiles of candidate genes were assessed and compared between peripheral blood mononuclear cells and prostate cancer cells. Subsequently, differentially expressed genes were inhibited and growth assays performed to elucidate their role in the growth of the cancer cells. Cell cycle, apoptosis and autophagy assays were performed to ascertain the mechanism of growth inhibition. Our results indicate that DGAT1, ABHD5, ACAT1 and ATGL are overexpressed in prostate cancer cells compared to PBMCs and of these overexpressed genes, DGAT1 and ABHD5 aid in the growth of the prostate cancer cells. Blocking the expression of both DGAT1 and ABHD5 results in inhibition of growth, cell cycle block and cell death. DGAT1 siRNA treatment inhibits lipid droplet formation and leads to autophagy where as ABHD5 siRNA treatment promotes accumulation of lipid droplets and leads to apoptosis. Both the siRNA treatments reduce AMPK phosphorylation, a key regulator of lipid metabolism. While DGAT1 siRNA reduces phosphorylation of ACC, the rate limiting enzyme in de novo fat synthesis and triggers phosphorylation of raptor and ULK-1 inducing autophagy and cell death, ABHD5 siRNA decreases P70S6 phosphorylation, leading to PARP cleavage, apoptosis and cell death. Interestingly, DGAT-1 is involved in the synthesis of triacylglycerol where as ABHD5 is a hydrolase and participates in the fatty acid oxidation process, yet inhibition of both enzymes similarly promotes prostate cancer cell death. Inhibition of either DGAT1 or ABHD5 leads to prostate cancer cell death. Both DGAT1 and ABHD5 can be selectively targeted to block prostate cancer cell growth.

Dietary Omega-3 Fatty Acids Prevented Adipocyte Hypertrophy by Downregulating DGAT-2 and FABP-4 in a Sex-Dependent Fashion.

PubMed

Balogun, Kayode A; Cheema, Sukhinder K

2016-01-01

Obesity is characterized by an increase in fat mass primarily as a result of adipocyte hypertrophy. Diets enriched in omega (n)-3 polyunsaturated fatty acids (PUFA) are suggested to reduce obesity, however, the mechanisms are not well understood. We investigated the effect of n-3 PUFA on adipocyte hypertrophy and the key genes involved in adipocyte hypertrophy. Female C57BL/6 mice were fed semi-purified diets (20 % w/w fat) containing high n-3 PUFA before mating, during pregnancy, and until weaning. Male and female offspring were continued on high n-3 PUFA (10 % w/w), medium n-3 PUFA (4 % w/w), or low n-3 PUFA (2 % w/w) diet for 16 weeks postweaning. Adipocyte area was quantified using microscopy, and gonadal mRNA expression of acyl CoA:diacylglycerol acyltransferase-2 (DGAT-2), fatty acid binding protein-4 (FABP-4) and leptin were measured. The high n-3 PUFA group showed higher levels of total n-3 PUFA in gonadal TAG compared to the medium and low n-3 PUFA groups (P < 0.001). The high n-3 PUFA male group had a lower adipocyte area compared to the medium and low n-3 PUFA group (P < 0.001); however, no difference was observed in females. The high n-3 PUFA male group showed lower mRNA expression of FABP-4, DGAT-2 and leptin compared to the low n-3 PUFA group, with no difference in females. Plasma lipid levels were lower in the high n-3 PUFA group compared to the other groups. Our findings show for the first time that n-3 PUFA prevents adipocyte hypertrophy by downregulating FABP-4, DGAT-2 and leptin; the effects are however sex-specific.

Productive performance of the dairy cattle Girolando breed mediated by the fat-related genes DGAT1 and LEP and their polymorphisms.

PubMed

Cardoso, S R; Queiroz, L B; Goulart, V Alonso; Mourão, G B; Benedetti, E; Goulart, L R

2011-12-01

Candidate genes have been associated with milk production in bovines, such as the diacylglycerol O-acyltransferase 1 (DGAT1) and leptin (LEP); however, they have not been simultaneously investigated nor have been evaluated in the Brazilian Girolando breed (Gir×Holstein, backcrossed to Holstein). Our aim was to determine the influence of fat-related genes, DGAT1 and LEP, and their polymorphisms on performance traits of milk production in the Girolando breed. Results indicated that the K allele of the DGAT1 gene showed a significant association with total and average daily milk production with additive effect. The LEP gene showed that the A allele and its homozygote are highly prevalent and almost fixed in this population and may have been favorably selected during backcrossing for the origin of this breed. The important impact of the K allele of the DGAT1 gene on milk production corroborates the initiative of performing marker-assisted selections with this gene in breeding programs of the Girolando breed. Copyright © 2011 Elsevier Ltd. All rights reserved.

Identification, optimisation and in vivo evaluation of oxadiazole DGAT-1 inhibitors for the treatment of obesity and diabetes.

PubMed

McCoull, William; Addie, Matthew S; Birch, Alan M; Birtles, Susan; Buckett, Linda K; Butlin, Roger J; Bowker, Suzanne S; Boyd, Scott; Chapman, Stephen; Davies, Robert D M; Donald, Craig S; Green, Clive P; Jenner, Chloe; Kemmitt, Paul D; Leach, Andrew G; Moody, Graeme C; Gutierrez, Pablo Morentin; Newcombe, Nicholas J; Nowak, Thorsten; Packer, Martin J; Plowright, Alleyn T; Revill, John; Schofield, Paul; Sheldon, Chris; Stokes, Steve; Turnbull, Andrew V; Wang, Steven J Y; Whalley, David P; Wood, J Matthew

2012-06-15

A novel series of DGAT-1 inhibitors was discovered from an oxadiazole amide high throughput screening (HTS) hit. Optimisation of potency and ligand lipophilicity efficiency (LLE) resulted in a carboxylic acid containing clinical candidate 53 (AZD3988), which demonstrated excellent DGAT-1 potency (0.6 nM), good pharmacokinetics and pre-clinical in vivo efficacy that could be rationalised through a PK/PD relationship. Copyright © 2012 Elsevier Ltd. All rights reserved.

Perilipin 1 Mediates Lipid Metabolism Homeostasis and Inhibits Inflammatory Cytokine Synthesis in Bovine Adipocytes

PubMed Central

Zhang, Shiqi; Liu, Guowen; Xu, Chuang; Liu, Lei; Zhang, Qiang; Xu, Qiushi; Jia, Hongdou; Li, Xiaobing; Li, Xinwei

2018-01-01

Dairy cows with ketosis displayed lipid metabolic disorder and high inflammatory levels. Adipose tissue is an active lipid metabolism and endocrine tissue and is closely related to lipid metabolism homeostasis and inflammation. Perilipin 1 (PLIN1), an adipocyte-specific lipid-coated protein, may be involved in the above physiological function. The aim of this study is to investigate the role of PLIN1 in lipid metabolism regulation and inflammatory factor synthesis in cow adipocytes. The results showed that PLIN1 overexpression upregulated the expression of fatty acid and triglyceride (TAG) synthesis molecule sterol regulator element-binding protein-1c (SREBP-1c) and its target genes, diacylglycerol acyltransferase (DGAT) 1, and DGAT2, but inhibited the expression of lipolysis enzymes hormone-sensitive lipase (HSL) and CGI-58 for adipose triglyceride lipase (ATGL), thus augmenting the fatty acids and TAG synthesis and inhibiting lipolysis. Importantly, PLIN1 overexpression inhibited the activation of the NF-κB inflammatory pathway and decreased the expression and content of tumor necrosis factor alpha (TNF-α), interleukin 1 beta (IL-1β), and interleukin 6 (IL-6) induced by lipopolysaccharide. Conversely, PLIN1 silencing inhibited TAG synthesis, promoted lipolysis, and overinduced the activation of the NF-κB inflammatory pathway in cow adipocytes. In ketotic cows, the expression of PLIN1 was markedly decreased, whereas lipid mobilization, NF-κB pathway, and downstream inflammatory cytokines were overinduced in adipose tissue. Taken together, these results indicate that PLIN1 can maintain lipid metabolism homeostasis and inhibit the NF-κB inflammatory pathway in adipocytes. However, low levels of PLIN1 reduced the inhibitory effect on fat mobilization, NF-κB pathway, and inflammatory cytokine synthesis in ketotic cows. PMID:29593725

Perilipin 1 Mediates Lipid Metabolism Homeostasis and Inhibits Inflammatory Cytokine Synthesis in Bovine Adipocytes.

PubMed

Zhang, Shiqi; Liu, Guowen; Xu, Chuang; Liu, Lei; Zhang, Qiang; Xu, Qiushi; Jia, Hongdou; Li, Xiaobing; Li, Xinwei

2018-01-01

Dairy cows with ketosis displayed lipid metabolic disorder and high inflammatory levels. Adipose tissue is an active lipid metabolism and endocrine tissue and is closely related to lipid metabolism homeostasis and inflammation. Perilipin 1 (PLIN1), an adipocyte-specific lipid-coated protein, may be involved in the above physiological function. The aim of this study is to investigate the role of PLIN1 in lipid metabolism regulation and inflammatory factor synthesis in cow adipocytes. The results showed that PLIN1 overexpression upregulated the expression of fatty acid and triglyceride (TAG) synthesis molecule sterol regulator element-binding protein-1c (SREBP-1c) and its target genes, diacylglycerol acyltransferase (DGAT) 1, and DGAT2, but inhibited the expression of lipolysis enzymes hormone-sensitive lipase (HSL) and CGI-58 for adipose triglyceride lipase (ATGL), thus augmenting the fatty acids and TAG synthesis and inhibiting lipolysis. Importantly, PLIN1 overexpression inhibited the activation of the NF-κB inflammatory pathway and decreased the expression and content of tumor necrosis factor alpha (TNF-α), interleukin 1 beta (IL-1β), and interleukin 6 (IL-6) induced by lipopolysaccharide. Conversely, PLIN1 silencing inhibited TAG synthesis, promoted lipolysis, and overinduced the activation of the NF-κB inflammatory pathway in cow adipocytes. In ketotic cows, the expression of PLIN1 was markedly decreased, whereas lipid mobilization, NF-κB pathway, and downstream inflammatory cytokines were overinduced in adipose tissue. Taken together, these results indicate that PLIN1 can maintain lipid metabolism homeostasis and inhibit the NF-κB inflammatory pathway in adipocytes. However, low levels of PLIN1 reduced the inhibitory effect on fat mobilization, NF-κB pathway, and inflammatory cytokine synthesis in ketotic cows.

Gene Expression in Plant Lipid Metabolism in Arabidopsis Seedlings

PubMed Central

Hsiao, An-Shan; Haslam, Richard P.; Michaelson, Louise V.; Liao, Pan; Napier, Johnathan A.; Chye, Mee-Len

2014-01-01

Events in plant lipid metabolism are important during seedling establishment. As it has not been experimentally verified whether lipid metabolism in 2- and 5-day-old Arabidopsis thaliana seedlings is diurnally-controlled, quantitative real-time PCR analysis was used to investigate the expression of target genes in acyl-lipid transfer, β-oxidation and triacylglycerol (TAG) synthesis and hydrolysis in wild-type Arabidopsis WS and Col-0. In both WS and Col-0, ACYL-COA-BINDING PROTEIN3 (ACBP3), DIACYLGLYCEROL ACYLTRANSFERASE1 (DGAT1) and DGAT3 showed diurnal control in 2- and 5-day-old seedlings. Also, COMATOSE (CTS) was diurnally regulated in 2-day-old seedlings and LONG-CHAIN ACYL-COA SYNTHETASE6 (LACS6) in 5-day-old seedlings in both WS and Col-0. Subsequently, the effect of CIRCADIAN CLOCK ASSOCIATED1 (CCA1) and LATE ELONGATED HYPOCOTYL (LHY) from the core clock system was examined using the cca1lhy mutant and CCA1-overexpressing (CCA1-OX) lines versus wild-type WS and Col-0, respectively. Results revealed differential gene expression in lipid metabolism between 2- and 5-day-old mutant and wild-type WS seedlings, as well as between CCA1-OX and wild-type Col-0. Of the ACBPs, ACBP3 displayed the most significant changes between cca1lhy and WS and between CCA1-OX and Col-0, consistent with previous reports that ACBP3 is greatly affected by light/dark cycling. Evidence of oil body retention in 4- and 5-day-old seedlings of the cca1lhy mutant in comparison to WS indicated the effect of cca1lhy on storage lipid reserve mobilization. Lipid profiling revealed differences in primary lipid metabolism, namely in TAG, fatty acid methyl ester and acyl-CoA contents amongst cca1lhy, CCA1-OX, and wild-type seedlings. Taken together, this study demonstrates that lipid metabolism is subject to diurnal regulation in the early stages of seedling development in Arabidopsis. PMID:25264899

Two bifunctional enzymes from the marine protist Thraustochytrium roseum: biochemical characterization of wax ester synthase/acyl-CoA:diacylglycerol acyltransferase activity catalyzing wax ester and triacylglycerol synthesis.

PubMed

Zhang, Nannan; Mao, Zejing; Luo, Ling; Wan, Xia; Huang, Fenghong; Gong, Yangmin

2017-01-01

Triacylglycerols (TAGs) and wax esters (WEs) are important neutral lipids which serve as energy reservoir in some plants and microorganisms. In recent years, these biologically produced neutral lipids have been regarded as potential alternative energy sources for biofuel production because of the increased interest on developing renewable and environmentally benign alternatives for fossil fuels. In bacteria, the final step in TAG and WE biosynthetic pathway is catalyzed by wax ester synthase/acyl coenzyme A (acyl-CoA):diacylglycerol acyltransferase (WS/DGAT). This bifunctional WS/DGAT enzyme is also a key enzyme in biotechnological production of liquid WE via engineering of plants and microorganisms. To date, knowledge about this class of biologically and biotechnologically important enzymes is mainly from biochemical characterization of WS/DGATs from Arabidopsis, jojoba and some bacteria that can synthesize both TAGs and WEs intracellularly, whereas little is known about WS/DGATs from eukaryotic microorganisms. Here, we report the identification and characterization of two bifunctional WS/DGAT enzymes (designated TrWSD4 and TrWSD5) from the marine protist Thraustochytrium roseum . Both TrWSD4 and TrWSD5 comprise a WS-like acyl-CoA acyltransferase domain and the recombinant proteins purified from Escherichia coli Rosetta (DE3) have substantial WS and lower DGAT activity. They exhibit WS activity towards various-chain-length saturated and polyunsaturated acyl-CoAs and fatty alcohols ranging from C 10 to C 18 . TrWSD4 displays WS activity with the lowest K m value of 0.14 μM and the highest k cat / K m value of 1.46 × 10 5  M -1  s -1 for lauroyl-CoA (C 12:0 ) in the presence of 100 μM hexadecanol, while TrWSD5 exhibits WS activity with the lowest K m value of 0.96 μM and the highest k cat / K m value of 9.83 × 10 4  M -1  s -1 for decanoyl-CoA (C 10:0 ) under the same reaction condition. Both WS/DGAT enzymes have the highest WS activity at 37 and 47 °C, and WS activity was greatly decreased when temperature exceeds 47 °C. TrWSD4 and TrWSD5 are insensitive to ionic strength and reduced WS activity was observed when salt concentration exceeded 800 mM. The potential of T. roseum WS/DGATs to establish novel process for biotechnological production of WEs was demonstrated by heterologous expression in recombinant yeast. Expression of either TrWSD4 or TrWSD5 in Saccharomyces cerevisiae quadruple mutant H1246, which is devoid of storage lipids, resulted in the accumulation of WEs, but not any detectable TAGs, indicating a predominant WS activity in yeast. This study demonstrates both in vitro WS and DGAT activity of two T. roseum WS/DGATs, which were characterized as unspecific acyltransferases accepting a broad range of acyl-CoAs and fatty alcohols as substrates for WS activity but displaying substrate preference for medium-chain acyl-CoAs. In vivo characterization shows that these two WS/DGATs predominantly function as wax synthase and presents the feasibility for production of WEs by heterologous hosts.

Regulation of Oil Biosynthesis in Algae

DTIC Science & Technology

2008-06-25

for future engineering purposes 3. Biochemical analysis of diacylglycerol acyltransferases ( DGATs ). These are key enzymes of oil biosynthesis...catalyzing the assembly of triacylglycerol in many organisms. 5 Genes predicted to encode DGATs and their role in triacylglycerol biosynthesis were identified

DGAT and triglyceride synthesis: a new target for obesity treatment?

PubMed

Chen, H C; Farese, R V

2000-07-01

Because triglycerides are considered essential for survival and their synthesis has been thought to occur through a single mechanism, inhibiting triglyceride synthesis has been largely unexplored as a possible target for obesity treatment. However, recent studies indicate that mice lacking acyl CoA:diacylglycerol acyltransferase (DGAT), a key enzyme in triglyceride synthesis, are viable and resistant to diet-induced obesity. Unexpectedly, this resistance is caused by a mechanism involving increased energy expenditure. These findings suggest that inhibiting specific components of triglyceride synthesis, such as DGAT, is feasible and may represent a novel approach to treating obesity.

[Effect of Jinlida on DGAT1 in Skeletal Muscle in Fat-Induced Insulin Resistance ApoE -/- Mice].

PubMed

Jin, Xin; Zhang, Hui-xin; Cui, Wen-wen

2015-06-01

To investigate the effect of Jinlida on DGAT1 in skeletal muscle in fat-induced insulin resistance ApoE-/- mice. Eight male C57BL/6J mice were used as normal group. 40 male ApoE -/- mice were fed high-fat diet for 16 weeks and divided into five groups: control group, rosiglitazone group, and Jinlida low, middle and high dose groups. Then corresponding drugs were administrated intragastrically for eight weeks. TG content in skeletal muscle was measured by enzymic enzymatic, Glucose tolerance test (OGTT) was used to evaluate the degree of insulin resistance in mice. The mRNA and protein expression of insulin receptor substrate (IRS-1) and diacylglycerol acyltransferase 1 (DGAT1) in skeletal muscle were measured by real-time quantitative reverse transcription PCR (RT-PCR)and Western blot. Jinlida particles reduced fasting blood glucose (FBG) cholesterol (TC), triglyceride (TG), free fatty acid (FFA)and fasting insulin (FIns) levels, raised insulin sensitive index (ISI), improved glucose tolerance, and reduced skeletal muscle lipid deposition in ApoE -/- mice significantly. Jinlida particles increased the expression of IRS-1 mRNA and protein, and reduced DGAT1. Jinlida can alleviate the expression of DGAT in skeletal muscle in fat-induced insulin resistance ApoE-/- mice.

Enhancing Cardiac Triacylglycerol Metabolism Improves Recovery From Ischemic Stress

PubMed Central

Liu, Li; Goldberg, Ira J.

2015-01-01

Elevated cardiac triacylglycerol (TAG) content is traditionally equated with cardiolipotoxicity and suggested to be a culprit in cardiac dysfunction. However, previous work demonstrated that myosin heavy-chain–mediated cardiac-specific overexpression of diacylglycerol transferase 1 (MHC-DGAT1), the primary enzyme for TAG synthesis, preserved cardiac function in two lipotoxic mouse models despite maintaining high TAG content. Therefore, we examined whether increased cardiomyocyte TAG levels due to DGAT1 overexpression led to changes in cardiac TAG turnover rates under normoxia and ischemia-reperfusion conditions. MHC-DGAT1 mice had elevated TAG content and synthesis rates, which did not alter cardiac function, substrate oxidation, or myocardial energetics. MHC-DGAT1 hearts had ischemia-induced lipolysis; however, when a physiologic mixture of long-chain fatty acids was provided, enhanced TAG turnover rates were associated with improved functional recovery from low-flow ischemia. Conversely, exogenous supply of palmitate during reperfusion suppressed elevated TAG turnover rates and impaired recovery from ischemia in MHC-DGAT1 hearts. Collectively, this study shows that elevated TAG content, accompanied by enhanced turnover, does not adversely affect cardiac function and, in fact, provides cardioprotection from ischemic stress. In addition, the results highlight the importance of exogenous supply of fatty acids when assessing cardiac lipid metabolism and its relationship with cardiac function. PMID:25858561

Structure-function analysis of diacylglycerol acyltransferase sequences from 70 organisms

USDA-ARS?s Scientific Manuscript database

Diacylglycerol acyltransferases (DGATs) catalyze the final and rate-limiting step of triacylglycerol (TAG) biosynthesis in eukaryotic organisms. Understanding the roles of DGATs will help to create transgenic plants with value-added properties and provide clues for therapeutic intervention for obes...

Expression of tung tree diacylglycerol acyltransferase 1 in E. coli

USDA-ARS?s Scientific Manuscript database

Diacylglycerol acyltransferases (DGATs) catalyze the last step of triacylglycerol (TAG) biosynthesis in eukaryotic organisms. DGAT isoforms have nonredundant functions in TAG biosynthesis in species such as tung tree (Vernicia fordii) which contains 80% high-value eleostearic acid in its seed oils. ...

Purification of recombinant tung tree diacylglycerol acyltransferases from E. coli

USDA-ARS?s Scientific Manuscript database

Understanding plant oil biosynthesis will help to create new oilseed crops with value-added properties to replace petroleum-based compounds. Diacylglycerol acyltransferases (DGATs) are key enzymes catalyzing the last step of triacylglycerol (TAG) biosynthesis in eukaryotes. Over-expression of DGATs ...

Bioengineering recombinant diacylglycerol acyltransferases

USDA-ARS?s Scientific Manuscript database

Diacylglycerol acyltransferases (DGATs) catalyze the last and rate-limiting step of triacylglycerol (TAG) biosynthesis in eukaryotic organisms. At least 115 DGAT sequences are identified from 69 organisms in the GenBank databases. Only a few papers have been published in the last 28 years on the exp...

The utilization of the acyl-CoA and the involvement PDAT and DGAT in the biosynthesis of erucic acid-rich triacylglycerols in Crambe seed oil.

PubMed

Furmanek, Tomasz; Demski, Kamil; Banaś, Walentyna; Haslam, Richard; Napier, Jonathan; Stymne, Sten; Banaś, Antoni

2014-04-01

The triacylglycerol of Crambe abyssinica seeds consist of 95% very long chain (>18 carbon) fatty acids (86% erucic acid; 22:1∆13) in the sn-1 and sn-3 positions. This would suggest that C. abyssinica triacylglycerols are not formed by the action of the phospholipid:diacylglycerol acyltransferase (PDAT), but are rather the results of acyl-CoA:diacylglycerol acyltransferase (DGAT) activity. However, measurements of PDAT and DGAT activities in microsomal membranes showed that C. abyssinica has significant PDAT activity, corresponding to about 10% of the DGAT activity during periods of rapid seed oil accumulation. The specific activity of DGAT for erucoyl-CoA had doubled at 19 days after flowering compared to earlier developmental stages, and was, at that stage, the preferred acyl donor, whereas the activities for 16:0-CoA and 18:1-CoA remained constant. This indicates that an expression of an isoform of DGAT with high specificity for erucoyl-CoA is induced at the onset of rapid erucic acid and oil accumulation in the C. abyssinica seeds. Analysis of the composition of the acyl-CoA pool during different stages of seed development showed that the percentage of erucoyl groups in acyl-CoA was much higher than in complex lipids at all stages of seed development except in the desiccation phase. These results are in accordance with published results showing that the rate limiting step in erucic acid accumulation in C. abyssinica oil is the utilization of erucoyl-CoA by the acyltransferases in the glycerol-3-phosphate pathway.

Preclinical pharmacokinetic characterization of 2-(4-(4-(5-(2-phenyl-5-(trifluoromethyl)oxazole-4-carboxamido)-1H-benzo[d]imidazol-2-yl)phenyl)cyclohexyl) acetic acid, a novel DGAT-1 inhibitor.

PubMed

Kwak, Eun-Young; Im, So Hee; Seo, Hyewon; Cho, Woon-Ki; Lee, Ye-Lim; Woo, Jaechun; Ahn, Sunjoo; Ahn, Sung-Hoon; Kwak, Hyun Jung; Ahn, Jin Hee; Bae, Myung Ae; Song, Jin Sook

2014-05-01

1. A novel diacylglyceride acyltransferase-1 (DGAT-1) inhibitor, 2-(4-(4-(5-(2-phenyl-5-(trifluoromethyl) oxazole-4-carboxamido)-1H-benzo[d]imidazol-2-yl)phenyl)cyclohexyl) acetic acid (KR-69232), was synthesized for a potential therapeutic use against several metabolic disorders, such as obesity, insulin resistance, and type II diabetes, characterized by excessive triglycerides (TGs) in the blood. 2. The half-lives against phase I metabolism were measured as 75.3 ± 20.9 min and over 120 min in rat and human liver microsomes, respectively. In Caco-2 cell monolayers, extremely low permeability (<0.13 × 10⁻⁶cm/s) was seen in the absorptive direction, predicting limited intestinal absorption of KR-69232. This compound was highly bound to rat and human plasma proteins (>99.8%). 3. With the intravenous administration of KR-69232 in rats (1, 2, and 5 mg/kg), non-linear kinetics were observed at the highest dose, with significantly higher systemic clearance, higher volume of distribution, and lower dose-normalized AUC. Following oral administration, it exhibited low bioavailability (<10%) and was absorbed slowly (T(max), 3.8-5.2 h) over the dose range. We also confirmed that considerable KR-69232 remained in the intestine at T(max), demonstrating its limited absorption into the systemic circulation.

Effects of canagliflozin on weight loss in high-fat diet-induced obese mice.

PubMed

Ji, Wenjun; Zhao, Mei; Wang, Meng; Yan, Wenhui; Liu, Yuan; Ren, Shuting; Lu, Jun; Wang, Bing; Chen, Lina

2017-01-01

Canagliflozin, an inhibitor of sodium glucose co-transporter (SGLT) 2, has been shown to reduce body weight during the treatment of type 2 diabetes mellitus (T2DM). In this study, we sought to determine the role of canagliflozin in body weight loss and liver injury in obesity. C57BL/6J mice were fed a high-fat diet to simulate diet-induced obesity (DIO). Canagliflozin (15 and 60 mg/kg) was administered to DIO mice for 4 weeks. Orlistat (10 mg/kg) was used as a positive control. The body weight, liver weight, liver morphology, total cholesterol (TC) and triglyceride (TG) levels were examined. Signaling molecules, including diacylgycero1 acyltransferase-2 (DGAT2), peroxisome proliferation receptor alpha-1 (PPARα1), PPARγ1, PPARγ2 mRNA levels and the protein expression of SGLT2 were evaluated. Canagliflozin reduced body weight, especially the high-dose canagliflozin, and resulted in increased body weight loss compared with orlistat. Moreover, canagliflozin reduced the liver weight and the ratio of liver weight to body weight, lowered the serum levels of TC and TG, and ameliorated liver steatosis. During the canagliflozin treatment, SGLT2, DGAT2, PPARγ1 and PPARγ2 were inhibited, and PPARα1 was elevated in the liver tissues. This finding may explain why body weight was reduced and secondary liver injury was ameliorated in response to canagliflozin. Together, the results suggest that canagliflozin may be a potential anti-obesity strategy.

[Therapeutic effects and mechanisms of Opuntia dillenii Haw on atherosclerosis of rats].

PubMed

Wang, Yu-chun; Qi, Zhan-peng; Liu, Zhen-zhong; Li, Tao; Cui, Hong-xia; Wang, Bao-qing; Chi, Na

2015-04-01

The research aimed to investigate the therapeutic effects and mechanisms of Opuntia dillenii Haw polysaccharide (OPS) on atherosclerosis of rats. First atherosclerotic rat models were established by high-fat and high-calcium diet. Thirty days later, the rats were treated with low dosage of OPS (0.2 g x kg(-1) x d(-1)) or high dosage of OPS (0.4 g x kg(-1) x d(-1)) by intraperitoneal injection for 60 days continuously. At the end of treatment, thoracic aorta rings were prepared and vasorelaxation of rat thoracic aorta in different experiment groups were determined by using 620M multi wire myograph system in vitro. Blood and livers of rats were collected. Then plasma levels of total cholesterol (TC), triglyceride (TG) and low density lipoprotein (LDL) of rats were separately determined using whole automatic biochemical analyzer; protein level of hepatic apolipoprotein B (ApoB) and that of hepatic diglyceride acyltransferase (Dgat1) were measured by Western Blot technique. Results showed that the ability of rat thoracic aorta to relax decreased markedly in the model group compared with that in the normal group, and significant differences existed in vasorelaxation ratios induced by different concentrations of carbamylcholine chloride (Carb) between these two groups (P < 0.01). After OPS treatment, the ability of rat thoracic aorta to relax improved markedly, the vasorelaxation ratios induced by Carb at 5 and 10 μmol x L(-1) were respectively 0.34 ± 0.08 and 0.62 ± 0.15 in the group treated with low dosage of OPS, while the ratios induced by Carb at 1 and 5 μmol x L(-1) were respectively 0.54 ± 0.08 and 0.98 ± 0.02 in the group treated with high dosage of OPS, which were all significantly different with those in the model group (P < 0.01). Plasma contents of TC, TG and LDL reduced significantly by the treatments both with low and high dosages of OPS compared with those in the model group (P < 0.01). Protein level of hepatic ApoB and that of hepatic Dgat1 decreased significantly after the treatment with high dosage of OPS compared with those in the model group (P < 0.01). These results indicate that OPS can markedly improve the vasorelaxation of thoracic aorta of atherosclerotic rats and has significant anti-atherosclerotic effect; inhibiting the expression of ApoB and Dgat1 and thus decreasing the amounts of TC, LDL and TG serving as one of the molecular mechanisms of its antiatherosclerosis effect.

Discovery of a novel series of benzimidazole derivatives as diacylglycerol acyltransferase inhibitors.

PubMed

Lee, Kyeong; Goo, Ja-Il; Jung, Hwa Young; Kim, Minkyoung; Boovanahalli, Shanthaveerappa K; Park, Hye Ran; Kim, Mun-Ock; Kim, Dong-Hyun; Lee, Hyun Sun; Choi, Yongseok

2012-12-15

A novel series of benzimidazole derivatives was prepared and evaluated for their diacylglycerol acyltransferase (DGAT) inhibitory activity using microsome from rat liver. Among the newly synthesized compounds, furfurylamine containing benzimidazole carboxamide 10j showed the most potent DGAT inhibitory effect (IC(50)=4.4 μM) and inhibited triglyceride formation in HepG2 cells. Furthermore, compound 10j reduced body weight gain of Institute of Cancer Research mice on a high-fat diet and decreased levels of total triglyceride, total cholesterol, and LDL-cholesterol in the blood accompanied with a significant increase in HDL-cholesterol level. Copyright © 2012 Elsevier Ltd. All rights reserved.

Decreased lipogenesis-promoting factors in adipose tissue in postmenopausal women with overweight on a Paleolithic-type diet.

PubMed

Blomquist, Caroline; Chorell, Elin; Ryberg, Mats; Mellberg, Caroline; Worrsjö, Evelina; Makoveichuk, Elena; Larsson, Christel; Lindahl, Bernt; Olivecrona, Gunilla; Olsson, Tommy

2017-10-26

We studied effects of diet-induced postmenopausal weight loss on gene expression and activity of proteins involved in lipogenesis and lipolysis in adipose tissue. Fifty-eight postmenopausal women with overweight (BMI 32.5 ± 5.5) were randomized to eat an ad libitum Paleolithic-type diet (PD) aiming for a high intake of protein and unsaturated fatty acids or a prudent control diet (CD) for 24 months. Anthropometry, plasma adipokines, gene expression of proteins involved in fat metabolism in subcutaneous adipose tissue (SAT) and lipoprotein lipase (LPL) activity and mass in SAT were measured at baseline and after 6 months. LPL mass and activity were also measured after 24 months. The PD led to improved insulin sensitivity (P < 0.01) and decreased circulating triglycerides (P < 0.001), lipogenesis-related factors, including LPL mRNA (P < 0.05), mass (P < 0.01), and activity (P < 0.001); as well as gene expressions of CD36 (P < 0.05), fatty acid synthase, FAS (P < 0.001) and diglyceride acyltransferase 2, DGAT2 (P < 0.001). The LPL activity (P < 0.05) and gene expression of DGAT2 (P < 0.05) and FAS (P < 0.05) were significantly lowered in the PD group versus the CD group at 6 months and the LPL activity (P < 0.05) remained significantly lowered in the PD group compared to the CD group at 24 months. Compared to the CD, the PD led to a more pronounced reduction of lipogenesis-promoting factors in SAT among postmenopausal women with overweight. This could have mediated the favorable metabolic effects of the PD on triglyceride levels and insulin sensitivity.

Extreme antagonistic pleiotropy effects of DGAT1 on fat, milk and protein yields

USDA-ARS?s Scientific Manuscript database

A large-scale analysis using 294,079 first lactation Holstein cows, as well as a group of contemporary Holsteins and a Holstein line unselected since 1964, were used to study the genetic architecture associated with a mutation in the DGAT1 gene that has large effects on milk production. The ‘G’ alle...

Discovery of a new mechanism for regulation of plant triacylglycerol metabolism: The peanut diacylglycerol acyltransferase-1 gene family transcriptome is highly enriched in alternative splicing variants

USDA-ARS?s Scientific Manuscript database

Triacylglycerols (TAGs) are the most important energy storage form in oilseed crops. Diacylglycerol acyltransferase (DGAT) catalyzes the rate-limiting step of the Kennedy pathway of TAG biosynthesis. To date, little is known about the regulation of DGAT activity in peanut (Arachis hypogaea), an agr...

Lead optimization of a pyridine-carboxamide series as DGAT-1 inhibitors.

PubMed

Ting, Pauline C; Lee, Joe F; Zorn, Nicolas; Kim, Hyunjin M; Aslanian, Robert G; Lin, Mingxiang; Smith, Michelle; Walker, Scott S; Cook, John; Van Heek, Margaret; Lachowicz, Jean

2013-02-15

The structure-activity relationship studies of a novel series of carboxylic acid derivatives of pyridine-carboxamides as DGAT-1 inhibitors is described. The optimization of the initial lead compound 6 based on in vitro and in vivo activity led to the discovery of key compounds 10j and 17h. Copyright © 2013 Elsevier Ltd. All rights reserved.

Characterization of type 2 diacylglycerol acyltransferases in Chlamydomonas reinhardtii reveals their distinct substrate specificities and functions in triacylglycerol biosynthesis.

PubMed

Liu, Jin; Han, Danxiang; Yoon, Kangsup; Hu, Qiang; Li, Yantao

2016-04-01

Diacylglycerol acyltransferases (DGATs) catalyze a rate-limiting step of triacylglycerol (TAG) biosynthesis in higher plants and yeast. The genome of the green alga Chlamydomonas reinhardtii has multiple genes encoding type 2 DGATs (DGTTs). Here we present detailed functional and biochemical analyses of Chlamydomonas DGTTs. In vitro enzyme analysis using a radiolabel-free assay revealed distinct substrate specificities of three DGTTs: CrDGTT1 preferred polyunsaturated acyl CoAs, CrDGTT2 preferred monounsaturated acyl CoAs, and CrDGTT3 preferred C16 CoAs. When diacylglycerol was used as the substrate, CrDGTT1 preferred C16 over C18 in the sn-2 position of the glycerol backbone, but CrDGTT2 and CrDGTT3 preferred C18 over C16. In vivo knockdown of CrDGTT1, CrDGTT2 or CrDGTT3 resulted in 20-35% decreases in TAG content and a reduction of specific TAG fatty acids, in agreement with the findings of the in vitro assay and fatty acid feeding test. These results demonstrate that CrDGTT1, CrDGTT2 and CrDGTT3 possess distinct specificities toward acyl CoAs and diacylglycerols, and may work in concert spatially and temporally to synthesize diverse TAG species in C. reinhardtii. CrDGTT1 was shown to prefer prokaryotic lipid substrates and probably resides in both the endoplasmic reticulum and chloroplast envelope, indicating its role in prokaryotic and eukaryotic TAG biosynthesis. Based on these findings, we propose a working model for the role of CrDGTT1 in TAG biosynthesis. This work provides insight into TAG biosynthesis in C. reinhardtii, and paves the way for engineering microalgae for production of biofuels and high-value bioproducts. © 2016 The Authors The Plant Journal © 2016 John Wiley & Sons Ltd.

Aphadilactones A-D, four diterpenoid dimers with DGAT inhibitory and antimalarial activities from a Meliaceae plant.

PubMed

Liu, Jia; He, Xiu-Feng; Wang, Gai-Hong; Merino, Emilio F; Yang, Sheng-Ping; Zhu, Rong-Xiu; Gan, Li-She; Zhang, Hua; Cassera, Maria B; Wang, He-Yao; Kingston, David G I; Yue, Jian-Min

2014-01-17

Aphadilactones A-D (1-4), four diastereoisomers possessing an unprecedented carbon skeleton, were isolated from the Meliaceae plant Aphanamixis grandifolia. Their challenging structures and absolute configurations were determined by a combination of spectroscopic data, chemical degradation, fragment synthesis, experimental CD spectra, and ECD calculations. Aphadilactone C (3) with the 5S,11S,5'S,11'S configuration showed potent and selective inhibition against the diacylglycerol O-acyltransferase-1 (DGAT-1) enzyme (IC50 = 0.46 ± 0.09 μM, selectivity index > 217) and is the strongest natural DGAT-1 inhibitor discovered to date. In addition, compounds 1-4 showed significant antimalarial activities with IC50 values of 190 ± 60, 1350 ± 150, 170 ± 10, and 120 ± 50 nM, respectively.

Dysregulation of hepatic fatty acid metabolism in chronic kidney disease.

PubMed

Jin, Kyubok; Norris, Keith; Vaziri, Nosratola D

2013-02-01

Chronic kidney disease (CKD) results in hypertriglyceridemia which is largely due to impaired clearance of triglyceride-rich lipoproteins occasioned by downregulation of lipoprotein lipase and very low-density lipoprotein (LDL) receptor in the skeletal muscle and adipose tissue and of hepatic lipase and LDL receptor-related protein in the liver. However, data on the effect of CKD on fatty acid metabolism in the liver is limited and was investigated here. Male Sprague-Dawley rats were randomized to undergo 5/6 nephrectomy (CRF) or sham operation (control) and observed for 12 weeks. The animals were then euthanized and their liver tissue tested for nuclear translocation (activation) of carbohydrate-responsive element binding protein (ChREBP) and sterol-responsive element binding protein-1 (SREBP-1) which independently regulate the expression of key enzyme in fatty acid synthesis, i.e. fatty acid synthase (FAS) and acyl-CoA carboxylase (ACC) as well as nuclear Peroxisome proliferator-activated receptor alpha (PPARα) which regulates the expression of enzymes involved in fatty acid oxidation and transport, i.e. L-FABP and CPT1A. In addition, the expression of ATP synthase α, ATP synthase β, glycogen synthase and diglyceride acyltransferase 1 (DGAT1) and DGAT2 were determined. Compared with controls, the CKD rats exhibited hypertriglyceridemia, elevated plasma and liver tissue free fatty acids, increased nuclear ChREBP and reduced nuclear SREBP-1 and PPARα, upregulation of ACC and FAS and downregulation of L-FABP, CPT1A, ATP synthase α, glycogen synthase and DGAT in the liver tissue. Liver in animals with advanced CKD exhibits ChREBP-mediated upregulation of enzymes involved in fatty acid synthesis, downregulation of PPARα-regulated fatty acid oxidation system and reduction of DGAT resulting in reduced fatty acid incorporation in triglyceride.

CAPN1, CAST, and DGAT1 genetic effects on preweaning performance, carcass quality traits, and residual variance of tenderness in a beef cattle population selected for haplotype and allele equalization

USDA-ARS?s Scientific Manuscript database

Genetic marker effects and type of inheritance are estimated with poor precision when minor marker allele frequencies are low. A stable composite population (MARC III) was subjected to marker assisted selection for multiple years to equalize specific marker frequencies to 1) estimate effect size an...

Identification of microRNAs involved in lipid biosynthesis and seed size in developing sea buckthorn seeds using high-throughput sequencing.

PubMed

Ding, Jian; Ruan, Chengjiang; Guan, Ying; Krishna, Priti

2018-03-05

Sea buckthorn is a plant of medicinal and nutritional importance owing in part to the high levels of essential fatty acids, linoleic (up to 42%) and α-linolenic (up to 39%) acids in the seed oil. Sea buckthorn can produce seeds either via the sexual pathway or by apomixis. The seed development and maturation programs are critically dependent on miRNAs. To understand miRNA-mediated regulation of sea buckthorn seed development, eight small RNA libraries were constructed for deep sequencing from developing seeds of a low oil content line 'SJ1' and a high oil content line 'XE3'. High-throughput sequencing identified 137 known miRNA from 27 families and 264 novel miRNAs. The potential targets of the identified miRNAs were predicted based on sequence homology. Nineteen (four known and 15 novel) and 22 (six known and 16 novel) miRNAs were found to be involved in lipid biosynthesis and seed size, respectively. An integrated analysis of mRNA and miRNA transcriptome and qRT-PCR identified some key miRNAs and their targets (miR164d-ARF2, miR168b-Δ9D, novelmiRNA-108-ACC, novelmiRNA-23-GPD1, novelmiRNA-58-DGAT1, and novelmiRNA-191-DGAT2) potentially involved in seed size and lipid biosynthesis of sea buckthorn seed. These results indicate the potential importance of miRNAs in regulating lipid biosynthesis and seed size in sea buckthorn.

Milk fatty acid unsaturation: genetic parameters and effects of stearoyl-CoA desaturase (SCD1) and acyl CoA: diacylglycerol acyltransferase 1 (DGAT1).

PubMed

Schennink, A; Heck, J M L; Bovenhuis, H; Visker, M H P W; van Valenberg, H J F; van Arendonk, J A M

2008-05-01

With regard to human health aspects of milk fat, increasing the amount of unsaturated fatty acids in milk is an important selection objective. The cow's diet has an influence on the degree of unsaturation, but literature suggests that genetics also plays a role. To estimate genetic variation in milk fatty acid unsaturation indices, milk fatty acid composition of 1,933 Dutch Holstein Friesian heifers was measured and unsaturation indices were calculated. An unsaturation index represents the concentration of the unsaturated product proportional to the sum of the unsaturated product and the saturated substrate. Intraherd heritabilities were moderate, ranging from 0.23 +/- 0.07 for conjugated linoleic acid (CLA) index to 0.46 +/- 0.09 for C16 index. We genotyped the cows for the SCD1 A293V and DGAT1 K232A polymorphisms, which are known to alter milk fatty acid composition. Both genes explain part of the genetic variation in unsaturation indices. The SCD1 V allele is associated with lower C10, C12, and C14 indices, and with higher C16, C18, and CLA indices in comparison to the SCD1 A allele, with no differences in total unsaturation index. In comparison to the DGAT1 K allele, the DGAT1 A allele is associated with lower C10, C12, C14, and C16 indices and with higher C18, CLA, and total indices. We conclude that selective breeding can contribute to higher unsaturation indices, and that selective breeding can capitalize on genotypic information of both the SCD1 A293V and the DGAT1 K232A polymorphism.

Treatment of rats with Jiangzhi Capsule improves liquid fructose-induced fatty liver: modulation of hepatic expression of SREBP-1c and DGAT-2.

PubMed

Zhao, Yuanyang; Pan, Yongquan; Yang, Yifan; Batey, Robert; Wang, Jianwei; Li, Yuhao

2015-06-02

Jiangzhi Capsule is an Australian listed patented traditional Chinese medicine and has been used for management of lipid abnormalities over the past 10 years. To obtain a better understanding regarding Jiangzhi Capsule, the present study investigated the effects and underlying mechanisms of Jiangzhi Capsule on chronic fructose overconsumption-induced lipid abnormalities. Male rats were treated with liquid fructose in their drinking water over 14 weeks. Jiangzhi Capsule was co-administered (once daily, by oral gavage) during the last 7 weeks. Indexes of lipid and glucose homeostasis were determined enzymatically, by ELISA and/or histologically. Gene expression was analyzed by real-time PCR, Western blot and/or immunohistochemistry. Treatment with Jiangzhi Capsule (100 mg/kg) attenuated fructose-induced excessive triglyceride accumulation and Oil Red O-stained area in the liver. This effect was accompanied by amelioration of hyperinsulinemia. There was no significant difference in intakes of fructose and chow, and body weight between fructose control and fructose Jiangzhi Capsule-treated groups. Mechanistically, Jiangzhi Capsule downregulated fructose-stimulated hepatic overexpression of sterol regulatory element binding protein (SREBP)-1/1c at the mRNA and protein levels. Accordingly, the SREBP-1c downstream genes, acetyl-CoA carboxylase-1 and stearoyl-CoA desaturase-1, were also inhibited. In addition, acyl-coenzyme A:diacylglycerol acyltransferase (DGAT)-2 expression at the mRNA and protein levels in the liver was also inhibited after Jiangzhi Capsule treatment. In contrast, Jiangzhi Capsule affected neither carbohydrate response element binding protein, peroxisome proliferator-activated receptor (PPAR)-gamma and DGAT-1, nor PPAR-alpha and its target genes. These findings demonstrate the anti-steatotic action of Jiangzhi Capsule in fructose-fed rats, and modulation of hepatic SREBP-1c and DGAT-2 involved in hepatic de novo synthesis of fatty acids and triglyceride, respectively. Our findings provide an evidence-based and mechanistic understanding of Jiangzhi Capsule supporting its application for the prevention and/or treatment of fatty liver and its associated disorders in clinical practice.

Role of the DGAT gene C79T single-nucleotide polymorphism in French obese subjects.

PubMed

Coudreau, Sylvie Kipfer; Tounian, Patrick; Bonhomme, Geneviève; Froguel, Philippe; Girardet, Jean-Philippe; Guy-Grand, Bernard; Basdevant, Arnaud; Clément, Karine

2003-10-01

Acyl-coenzyme A, diacylglycerol acyltransferase (DGAT), is a key enzyme involved in adipose-cell triglyceride storage. A 79-bp T-to-C single-nucleotide polymorphism (SNP) on the 3' region of the DGAT transcriptional site has been reported to increase promoter activity and is associated with higher BMI in Turkish women. To validate the possible role of this genetic variant in obesity, as well as the variant's possible cellular-functional significance, we performed an association study between the T79C change and several obesity-related phenotypes in 1357 obese French adults and children. The prevalence of the T79C SNP was similar between obese adults and children when each group was compared with the controls. (CC genotype carrier frequencies were 0.25 to 0.29 in the obese groups and 0.21 in controls; p > 0.05.) In each of the obese adult and child groups studied, the T79C variant was not found to be associated with any of the obesity-related phenotypes tested. Although the T79C SNP of the DGAT gene was studied in several groups of white subjects, the association between this SNP and obesity-related phenotypes, previously described, was not confirmed in our population.

DGAT1 underlies large genetic variation in milk-fat composition of dairy cows.

PubMed

Schennink, A; Stoop, W M; Visker, M H P W; Heck, J M L; Bovenhuis, H; van der Poel, J J; van Valenberg, H J F; van Arendonk, J A M

2007-10-01

Dietary fat may play a role in the aetiology of many chronic diseases. Milk and milk-derived foods contribute substantially to dietary fat, but have a fat composition that is not optimal for human health. We measured the fat composition of milk samples in 1918 Dutch Holstein Friesian cows in their first lactation and estimated genetic parameters for fatty acids. Substantial genetic variation in milk-fat composition was found: heritabilities were high for short- and medium-chain fatty acids (C4:0-C16:0) and moderate for long-chain fatty acids (saturated and unsaturated C18). We genotyped 1762 cows for the DGAT1 K232A polymorphism, which is known to affect milk-fat percentage, to study the effect of the polymorphism on milk-fat composition. We found that the DGAT1 K232A polymorphism has a clear influence on milk-fat composition. The DGAT1 allele that encodes lysine (K) at position 232 (232K) is associated with more saturated fat; a larger fraction of C16:0; and smaller fractions of C14:0, unsaturated C18 and conjugated linoleic acid (P < 0.001). We conclude that selective breeding can make a significant contribution to change the fat composition of cow's milk.

Regulation of triglyceride metabolism. I. Eukaryotic neutral lipid synthesis: "Many ways to skin ACAT or a DGAT".

PubMed

Turkish, Aaron; Sturley, Stephen L

2007-04-01

Esterification of sterols, fatty acids and other alcohols into biologically inert forms conserves lipid resources for many cellular functions. Paradoxically, the accumulation of neutral lipids such as cholesteryl ester or triglyceride, is linked to several major disease pathologies. In a remarkable example of genetic expansion, there are at least eleven acyltransferase reactions that lead to neutral lipid production. In this review, we speculate that the complexity and apparent redundancy of neutral lipid synthesis may actually hasten rather than impede the development of novel, isoform-specific, therapeutic interventions for acne, type 2 diabetes, obesity, hyperlipidemia, fatty liver disease, and atherosclerosis.

Altered lipid composition and enhanced lipid production in green microalga by introduction of brassica diacylglycerol acyltransferase 2

PubMed Central

Ahmad, Irshad; Sharma, Anil K.; Daniell, Henry; Kumar, Shashi

2015-01-01

Summary Higher lipid biosynthesis and accumulation are important to achieve economic viability of biofuel production via microalgae. To enhance lipid content, Chlamydomonas reinhardtii was genetically engineered with a key enzyme diacylglycerol acyltransferase (BnDGAT2) from Brassica napus, responsible for neutral lipid biosynthesis. The transformed colonies harbouring aph7 gene, screened on hygromycin-supplemented medium, achieved transformation frequency of ~120 ± 10 colonies/1 × 106 cells. Transgene integration and expression were confirmed by PCR, Southern blots, staining lipid droplets, proteins and spectro-fluorometric analysis of Nile red-stained cells. The neutral lipid is a major class (over 80% of total lipids) and most significant requirement for biodiesel production; this was remarkably higher in the transformed alga than the untransformed control. The levels of saturated fatty acids in the transformed alga decreased to about 7% while unsaturated fatty acids increased proportionately when compared to wild type cells. Polyunsaturated fatty acids, especially α-linolenic acid, an essential omega-3 fatty acid, were enhanced up to 12% in the transformed line. Nile red staining confirmed formation of a large number of lipid globules in the transformed alga. Evaluation of long-term stability and vitality of the transgenic alga revealed that cryopreservation produced significantly higher quantity of lipid than those maintained continuously over 128 generations on solid medium. The overexpression of BnDGAT2 significantly altered the fatty acids profile in the transformed alga. Results of this study offer a valuable strategy of genetic manipulation for enhancing polyunsaturated fatty acids and neutral lipids for biofuel production in algae. PMID:25403771

Effect of Quercetin on Hepatitis C Virus Life Cycle: From Viral to Host Targets.

PubMed

Rojas, Ángela; Del Campo, Jose A; Clement, Sophie; Lemasson, Matthieu; García-Valdecasas, Marta; Gil-Gómez, Antonio; Ranchal, Isidora; Bartosch, Birke; Bautista, Juan D; Rosenberg, Arielle R; Negro, Francesco; Romero-Gómez, Manuel

2016-08-22

Quercetin is a natural flavonoid, which has been shown to have anti hepatitis C virus (HCV) properties. However, the exact mechanisms whereby quercetin impacts the HCV life cycle are not fully understood. We assessed the effect of quercetin on different steps of the HCV life cycle in Huh-7.5 cells and primary human hepatocytes (PHH) infected with HCVcc. In both cell types, quercetin significantly decreased i) the viral genome replication; ii) the production of infectious HCV particles and iii) the specific infectivity of the newly produced viral particles (by 85% and 92%, Huh7.5 and PHH respectively). In addition, when applied directly on HCV particles, quercetin reduced their infectivity by 65%, suggesting that it affects the virion integrity. Interestingly, the HCV-induced up-regulation of diacylglycerol acyltransferase (DGAT) and the typical localization of the HCV core protein to the surface of lipid droplets, known to be mediated by DGAT, were both prevented by quercetin. In conclusion, quercetin appears to have direct and host-mediated antiviral effects against HCV.

Effect of Quercetin on Hepatitis C Virus Life Cycle: From Viral to Host Targets

PubMed Central

Rojas, Ángela; Del Campo, Jose A.; Clement, Sophie; Lemasson, Matthieu; García-Valdecasas, Marta; Gil-Gómez, Antonio; Ranchal, Isidora; Bartosch, Birke; Bautista, Juan D.; Rosenberg, Arielle R.; Negro, Francesco; Romero-Gómez, Manuel

2016-01-01

Quercetin is a natural flavonoid, which has been shown to have anti hepatitis C virus (HCV) properties. However, the exact mechanisms whereby quercetin impacts the HCV life cycle are not fully understood. We assessed the effect of quercetin on different steps of the HCV life cycle in Huh-7.5 cells and primary human hepatocytes (PHH) infected with HCVcc. In both cell types, quercetin significantly decreased i) the viral genome replication; ii) the production of infectious HCV particles and iii) the specific infectivity of the newly produced viral particles (by 85% and 92%, Huh7.5 and PHH respectively). In addition, when applied directly on HCV particles, quercetin reduced their infectivity by 65%, suggesting that it affects the virion integrity. Interestingly, the HCV-induced up-regulation of diacylglycerol acyltransferase (DGAT) and the typical localization of the HCV core protein to the surface of lipid droplets, known to be mediated by DGAT, were both prevented by quercetin. In conclusion, quercetin appears to have direct and host-mediated antiviral effects against HCV. PMID:27546480

GosB Inhibits Triacylglycerol Synthesis and Promotes Cell Survival in Mouse Mammary Epithelial Cells.

PubMed

Xu, Gaoxiao; Duan, Saixing; Hou, Jianye; Wei, Zhongxin; Zhao, Guangwei

2017-01-01

It has been demonstrated that the activator protein related transcription factor Finkel-Biskis-Jinkins murine osteosarcoma B (GosB) is involved in preadipocyte differentiation and triacylglycerol synthesis. However, the role of GosB in regulating the synthesis of milk fatty acid in mouse mammary glands remains unclear. This research uncovered potentially new roles of GosB in suppressing milk fatty acid synthesis. Results revealed that GosB had the highest expression in lung tissue and showed a higher expression level during nonlactation than during lactation. GosB inhibited the expression of fatty acid synthase (FASN) , stearoyl-CoA desaturase (SCD) , fatty acid binding protein 4 (FABP4) , diacylglycerol acyltransferase 1 (DGAT1) , perilipin 2 (PLIN2) , perilipin 3 (PLIN3) , and C/EBPα in mouse mammary gland epithelial cells (MEC). In addition, GosB reduced cellular triglyceride content and the accumulation of lipid droplets; in particular, GosB enhanced saturated fatty acid concentration (C16:0 and C18:0). The PPAR γ agonist, rosiglitazone (ROSI), promoted apoptosis and inhibited cell proliferation. GosB increased the expression of Bcl-2 and protected MEC from ROSI-induced apoptosis. Furthermore, MECs were protected from apoptosis through the GosB regulation of intracellular calcium concentrations. These findings suggest that GosB may regulate mammary epithelial cells milk fat synthesis and apoptosis via PPAR γ in mouse mammary glands.

Mangiferin treatment inhibits hepatic expression of acyl-coenzyme A:diacylglycerol acyltransferase-2 in fructose-fed spontaneously hypertensive rats: a link to amelioration of fatty liver.

PubMed

Xing, Xiaomang; Li, Danyang; Chen, Dilong; Zhou, Liang; Chonan, Ritsu; Yamahara, Johji; Wang, Jianwei; Li, Yuhao

2014-10-15

Mangiferin, a xanthone glucoside, and its associated traditional herbs have been demonstrated to improve abnormalities of lipid metabolism. However, its underlying mechanisms remain largely unclear. This study investigated the anti-steatotic effect of mangiferin in fructose-fed spontaneously hypertensive rat (SHR)s that have a mutation in sterol regulatory element binding protein (SREBP)-1. The results showed that co-administration of mangiferin (15 mg/kg, once daily, by oral gavage) over 7 weeks dramatically diminished fructose-induced increases in hepatic triglyceride content and Oil Red O-stained area in SHRs. However, blood pressure, fructose and chow intakes, white adipose tissue weight and metabolic parameters (plasma concentrations of glucose, insulin, triglyceride, total cholesterol and non-esterified fatty acids) were unaffected by mangiferin treatment. Mechanistically, mangiferin treatment suppressed acyl-coenzyme A:diacylglycerol acyltransferase (DGAT)-2 expression at the mRNA and protein levels in the liver. In contrast, mangiferin treatment was without effect on hepatic mRNA and/or protein expression of SREBP-1/1c, carbohydrate response element binding protein, liver pyruvate kinase, fatty acid synthase, acetyl-CoA carboxylase-1, stearoyl-CoA desaturase-1, DGAT-1, monoacyglycerol acyltransferase-2, microsomal triglyceride transfer protein, peroxisome proliferator-activated receptor-alpha, carnitine palmitoyltransferase-1 and acyl-CoA oxidase. Collectively, our results suggest that mangiferin treatment ameliorates fatty liver in fructose-fed SHRs by inhibiting hepatic DGAT-2 that catalyzes the final step in triglyceride biosynthesis. The anti-steatotic effect of mangiferin may occur independently of the hepatic signals associated with de novo fatty acid synthesis and oxidation. Copyright © 2014 Elsevier Inc. All rights reserved.

Using lipidomics to reveal details of lipid accumulation in developing seeds from oilseed rape (Brassica napus L.).

PubMed

Woodfield, Helen K; Cazenave-Gassiot, Amaury; Haslam, Richard P; Guschina, Irina A; Wenk, Markus R; Harwood, John L

2018-03-01

With dwindling available agricultural land, concurrent with increased demand for oil, there is much current interest in raising oil crop productivity. We have been addressing this issue by studying the regulation of oil accumulation in oilseed rape (Brassica napus L). As part of this research we have carried out a detailed lipidomic analysis of developing seeds. The molecular species distribution in individual lipid classes revealed quite distinct patterns and showed where metabolic connections were important. As the seeds developed, the molecular species distributions changed, especially in the period of early (20days after flowering, DAF) to mid phase (27DAF) of oil accumulation. The patterns of molecular species of diacylglycerol, phosphatidylcholine and acyl-CoAs were used to predict the possible relative contributions of diacylglycerol acyltransferase (DGAT) and phospholipid:diacylglycerol acyltransferase to triacylglycerol production. Our calculations suggest that DGAT may hold a more important role in influencing the molecular composition of TAG. Enzyme selectivity had an important influence on the final molecular species patterns. Our data contribute significantly to our understanding of lipid accumulation in the world's third most important oil crop. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Knockdown of Triglyceride Synthesis Does Not Enhance Palmitate Lipotoxicity or Prevent Oleate-Mediated Rescue in Rat Hepatocytes

PubMed Central

Leamy, Alexandra K.; Hasenour, Clinton M.; Egnatchik, Robert A.; Trenary, Irina A.; Yao, Conghui; Patti, Gary J.; Shiota, Masakazu; Young, Jamey D.

2016-01-01

Experiments in a variety of cell types, including hepatocytes, consistently demonstrate the acutely lipotoxic effects of saturated fatty acids, such as palmitate (PA), but not unsaturated fatty acids, such as oleate (OA). PA+OA co-treatment fully prevents PA lipotoxicity through mechanisms that are not well defined but which have been previously attributed to more efficient esterification and sequestration of PA into triglycerides (TGs) when OA is abundant. However, this hypothesis has never been directly tested by experimentally modulating the relative partitioning of PA/OA between TGs and other lipid fates in hepatocytes. In this study, we found that addition of OA to PA-treated hepatocytes enhanced TG synthesis, reduced total PA uptake and PA lipid incorporation, decreased phospholipid saturation and rescued PA-induced ER stress and lipoapotosis. Knockdown of diacylglycerol acyltransferase (DGAT), the rate-limiting step in TG synthesis, significantly reduced TG accumulation without impairing OAmediated rescue of PA lipotoxicity. In both wild-type and DGAT-knockdown hepatocytes, OA cotreatment significantly reduced PA lipid incorporation and overall phospholipid saturation compared to PA-treated hepatocytes. These data indicate that OA’s protective effects do not require increased conversion of PA into inert TGs, but instead may be due to OA’s ability to compete against PA for cellular uptake and/or esterification and, thereby, normalize the composition of cellular lipids in the presence of a toxic PA load. PMID:27249207

Use of Limited Proteolysis and Mutagenesis To Identify Folding Domains and Sequence Motifs Critical for Wax Ester Synthase/Acyl Coenzyme A:Diacylglycerol Acyltransferase Activity

PubMed Central

Villa, Juan A.; Cabezas, Matilde; de la Cruz, Fernando

2014-01-01

Triacylglycerols and wax esters are synthesized as energy storage molecules by some proteobacteria and actinobacteria under stress. The enzyme responsible for neutral lipid accumulation is the bifunctional wax ester synthase/acyl-coenzyme A (CoA):diacylglycerol acyltransferase (WS/DGAT). Structural modeling of WS/DGAT suggests that it can adopt an acyl-CoA-dependent acyltransferase fold with the N-terminal and C-terminal domains connected by a helical linker, an architecture demonstrated experimentally by limited proteolysis. Moreover, we found that both domains form an active complex when coexpressed as independent polypeptides. The structural prediction and sequence alignment of different WS/DGAT proteins indicated catalytically important motifs in the enzyme. Their role was probed by measuring the activities of a series of alanine scanning mutants. Our study underscores the structural understanding of this protein family and paves the way for their modification to improve the production of neutral lipids. PMID:24296496

Two Acyltransferases Contribute Differently to Linolenic Acid Levels in Seed Oil1[OPEN

PubMed Central

Stymne, Sten

2017-01-01

Acyltransferases are key contributors to triacylglycerol (TAG) synthesis and, thus, are of great importance for seed oil quality. The effects of increased or decreased expression of ACYL-COENZYME A:DIACYLGLYCEROL ACYLTRANSFERASE1 (DGAT1) or PHOSPHOLIPID:DIACYLGLYCEROL ACYLTRANSFERASE (PDAT) on seed lipid composition were assessed in several Camelina sativa lines. Furthermore, in vitro assays of acyltransferases in microsomal fractions prepared from developing seeds of some of these lines were performed. Decreased expression of DGAT1 led to an increased percentage of 18:3n-3 without any change in total lipid content of the seed. The tri-18:3 TAG increase occurred predominantly in the cotyledon, as determined with matrix-assisted laser desorption/ionization-mass spectrometry, whereas species with two 18:3n-3 acyl groups were elevated in both cotyledon and embryonal axis. PDAT overexpression led to a relative increase of 18:2n-6 at the expense of 18:3n-3, also without affecting the total lipid content. Differential distributions of TAG species also were observed in different parts of the seed. The microsomal assays revealed that C. sativa seeds have very high activity of diacylglycerol-phosphatidylcholine interconversion. The combination of analytical and biochemical data suggests that the higher 18:2n-6 content in the seed oil of the PDAT overexpressors is due to the channeling of fatty acids from phosphatidylcholine into TAG before being desaturated to 18:3n-3, caused by the high activity of PDAT in general and by PDAT specificity for 18:2n-6. The higher levels of 18:3n-3 in DGAT1-silencing lines are likely due to the compensatory activity of a TAG-synthesizing enzyme with specificity for this acyl group and more desaturation of acyl groups occurring on phosphatidylcholine. PMID:28235891

A Functional, Genome-wide Evaluation of Liposensitive Yeast Identifies the “ARE2 Required for Viability” (ARV1) Gene Product as a Major Component of Eukaryotic Fatty Acid Resistance*

PubMed Central

Ruggles, Kelly V.; Garbarino, Jeanne; Liu, Ying; Moon, James; Schneider, Kerry; Henneberry, Annette; Billheimer, Jeff; Millar, John S.; Marchadier, Dawn; Valasek, Mark A.; Joblin-Mills, Aidan; Gulati, Sonia; Munkacsi, Andrew B.; Repa, Joyce J.; Rader, Dan; Sturley, Stephen L.

2014-01-01

The toxic subcellular accumulation of lipids predisposes several human metabolic syndromes, including obesity, type 2 diabetes, and some forms of neurodegeneration. To identify pathways that prevent lipid-induced cell death, we performed a genome-wide fatty acid sensitivity screen in Saccharomyces cerevisiae. We identified 167 yeast mutants as sensitive to 0.5 mm palmitoleate, 45% of which define pathways that were conserved in humans. 63 lesions also impacted the status of the lipid droplet; however, this was not correlated to the degree of fatty acid sensitivity. The most liposensitive yeast strain arose due to deletion of the “ARE2 required for viability” (ARV1) gene, encoding an evolutionarily conserved, potential lipid transporter that localizes to the endoplasmic reticulum membrane. Down-regulation of mammalian ARV1 in MIN6 pancreatic β-cells or HEK293 cells resulted in decreased neutral lipid synthesis, increased fatty acid sensitivity, and lipoapoptosis. Conversely, elevated expression of human ARV1 in HEK293 cells or mouse liver significantly increased triglyceride mass and lipid droplet number. The ARV1-induced hepatic triglyceride accumulation was accompanied by up-regulation of DGAT1, a triglyceride synthesis gene, and the fatty acid transporter, CD36. Furthermore, ARV1 was identified as a transcriptional of the protein peroxisome proliferator-activated receptor α (PPARα), a key regulator of lipid homeostasis whose transcriptional targets include DGAT1 and CD36. These results implicate ARV1 as a protective factor in lipotoxic diseases due to modulation of fatty acid metabolism. In conclusion, a lipotoxicity-based genetic screen in a model microorganism has identified 75 human genes that may play key roles in neutral lipid metabolism and disease. PMID:24273168

Choline supplementation restores substrate balance and alleviates complications of Pcyt2 deficiency.

PubMed

Schenkel, Laila C; Sivanesan, Sugashan; Zhang, Junzeng; Wuyts, Birgitte; Taylor, Adrian; Verbrugghe, Adronie; Bakovic, Marica

2015-11-01

Choline plays a critical role in systemic lipid metabolism and hepatic function. Here we conducted a series of experiments to investigate the effect of choline supplementation on metabolically altered Pcyt2(+/-) mice. In Pcyt2(+/-) mice, the membrane phosphatidylethanolamine (PE) turnover is reduced and the formation of fatty acids (FA) and triglycerides (TAG) increased, resulting in hypertriglyceridemia, liver steatosis and obesity. One month of choline supplementation reduced the incorporation of FA into TAG and facilitated TAG degradation in Pcyt2(+/-) adipocytes, plasma and liver. Choline particularly stimulated adipocyte and liver TAG lipolysis by specific lipases (ATGL, LPL and HSL) and inhibited TAG formation by DGAT1 and DGAT2. Choline also activated the liver AMPK and mitochondrial FA oxidation gene PPARα and reduced the FA synthesis genes SREBP1, SCD1 and FAS. Liver (HPLC) and plasma (tandem mass spectroscopy and (1)H-NMR) metabolite profiling established that Pcyt2(+/-) mice have reduced membrane cholesterol/sphingomyelin ratio and the homocysteine/methionine cycle that were improved by choline supplementation. These data suggest that supplementary choline is beneficial for restoring FA and TAG homeostasis under conditions of obesity caused by impaired PE synthesis. Copyright © 2015 Elsevier Inc. All rights reserved.

Technical note: Selection of suitable reference genes for studying gene expression in milk somatic cell of yak (Bos grunniens) during the lactation cycle.

PubMed

Bai, W L; Yin, R H; Zhao, S J; Jiang, W Q; Yin, R L; Ma, Z J; Wang, Z Y; Zhu, Y B; Luo, G B; Yang, R J; Zhao, Z H

2014-02-01

Quantitative real-time PCR is the most sensitive technique for gene expression analysis. Data normalization is essential to correct for potential errors incurred in all steps from RNA isolation to PCR amplification. The commonly accepted approach for normalization is the use of reference gene. Until now, no suitable reference genes have been available for data normalization of gene expression in milk somatic cells of lactating yaks across lactation. In the present study, we evaluated the transcriptional stability of 10 candidate reference genes in milk somatic cells of lactating yak, including ACTB, B2M, GAPDH, GTP, MRPL39, PPP1R11, RPS9, RPS15, UXT, and RN18S1. Four genes, RPS9, PPP1R11, UXT, and MRPL39, were identified as being the most stable genes in milk somatic cells of lactating yak. Using the combination of RPS9, PPP1R11, UXT, and MRPL39 as reference genes, we further assessed the relative expression of 4 genes of interest in milk somatic cells of yak across lactation, including ELF5, ABCG2, SREBF2, and DGAT1. Compared with expression in colostrum, the overall transcription levels of ELF5, ABCG2, and SREBF2 in milk were found to be significantly upregulated in early, peak, and late lactation, and significantly downregulated thereafter, before the dry period. A similar pattern was observed in the relative expression of DGAT1, but no significant difference was revealed in its expression in milk from late lactation compared with colostrum. Based on these results, we suggest that the geometric mean of RPS9, PPP1R11, UXT, and MRPL39 can be used for normalization of real-time PCR data in milk somatic cells of lactating yak, if similar experiments are performed. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Diacylglycerol Acyltransferase 1 Is Regulated by Its N-Terminal Domain in Response to Allosteric Effectors.

PubMed

Caldo, Kristian Mark P; Acedo, Jeella Z; Panigrahi, Rashmi; Vederas, John C; Weselake, Randall J; Lemieux, M Joanne

2017-10-01

Diacylglycerol acyltransferase 1 (DGAT1) is an integral membrane enzyme catalyzing the final and committed step in the acyl-coenzyme A (CoA)-dependent biosynthesis of triacylglycerol (TAG). The biochemical regulation of TAG assembly remains one of the least understood areas of primary metabolism to date. Here, we report that the hydrophilic N-terminal domain of Brassica napus DGAT1 (BnaDGAT1 1-113 ) regulates activity based on acyl-CoA/CoA levels. The N-terminal domain is not necessary for acyltransferase activity and is composed of an intrinsically disordered region and a folded segment. We show that the disordered region has an autoinhibitory function and a dimerization interface, which appears to mediate positive cooperativity, whereas the folded segment of the cytosolic region was found to have an allosteric site for acyl-CoA/CoA. Under increasing acyl-CoA levels, the binding of acyl-CoA with this noncatalytic site facilitates homotropic allosteric activation. Enzyme activation, on the other hand, is prevented under limiting acyl-CoA conditions (low acyl-CoA-to-CoA ratio), whereby CoA acts as a noncompetitive feedback inhibitor through interaction with the same folded segment. The three-dimensional NMR solution structure of the allosteric site revealed an α-helix with a loop connecting a coil fragment. The conserved amino acid residues in the loop interacting with CoA were identified, revealing details of this important regulatory element for allosteric regulation. Based on these results, a model is proposed illustrating the role of the N-terminal domain of BnaDGAT1 as a positive and negative modulator of TAG biosynthesis. © 2017 American Society of Plant Biologists. All Rights Reserved.

Heterologous expression of a thermophilic diacylglycerol acyltransferase triggers triglyceride accumulation in Escherichia coli.

PubMed

Lázaro, Beatriz; Villa, Juan A; Santín, Omar; Cabezas, Matilde; Milagre, Cintia D F; de la Cruz, Fernando; Moncalián, Gabriel

2017-01-01

Triglycerides (TAGs), the major storage molecules of metabolic energy and source of fatty acids, are produced as single cell oil by some oleogenic microorganisms. However, these microorganisms require strict culture conditions, show low carbon source flexibilities, lack efficient genetic modification tools and in some cases pose safety concerns. TAGs have essential applications such as behaving as a source for added-value fatty acids or giving rise to the production of biodiesel. Hence, new alternative methods are urgently required for obtaining these oils. In this work we describe TAG accumulation in the industrially appropriate microorganism Escherichia coli expressing the heterologous enzyme tDGAT, a wax ester synthase/triacylglycerol:acylCoA acyltranferase (WS/DGAT). With this purpose, we introduce a codon-optimized gene from the thermophilic actinomycete Thermomonospora curvata coding for a WS/DGAT into different E. coli strains, describe the metabolic effects associated to the expression of this protein and evaluate neutral lipid accumulation. We observe a direct relation between the expression of this WS/DGAT and TAG production within a wide range of culture conditions. More than 30% TAGs were detected within the bacterial neutral lipids in 90 minutes after induction. TAGs were observed to be associated with the hydrophobic enzyme while forming round intracytoplasmic bodies, which could represent a bottleneck for lipid accumulation in E. coli. We detected an increase of almost 3-fold in the monounsaturated fatty acids (MUFA) occurring in the recombinant strains. These MUFA were predominant in the accumulated TAGs achieving 46% of the TAG fatty acids. These results set the basis for further research on the achievement of a suitable method towards the sustainable production of these neutral lipids.

Milk fatty acid profile is modulated by DGAT1 and SCD1 genotypes in dairy cattle on pasture and strategic supplementation.

PubMed

Carvajal, A M; Huircan, P; Dezamour, J M; Subiabre, I; Kerr, B; Morales, R; Ungerfeld, E M

2016-05-09

Milk fat composition is important to consumer health. During the last decade, some fatty acids (FA) have received attention because of their functional and beneficial effects on human health. The milk FA profile is affected by both diet and genetics. Differences in milk fat composition are based on biochemical pathways, and candidate genes have been proposed to explain FA profile variation. Here, the association between DGAT1 K232A, SCD1 A293V, and LEPR T945M markers with milk fat composition in southern Chile was evaluated. We selected five herds of Holstein-Friesian, Jersey, Frisón Negro, Montbeliarde, and Overo Colorado cows (pasture-grazed) that received strategic supplementation with concentrates and conserved forages. We genotyped the SNPs and calculated allele frequencies and Hardy-Weinberg equilibrium. Milk fat composition was determined for individual milk samples over a year, and associations between genotypes and milk composition were studied. The most frequent variants for DGAT1, SCD1, and LEPR polymorphisms were GC/GC, C, and C, respectively. The DGAT1 GC/GC allele was associated with lower milk fat and protein content, lower saturated fatty acid levels, and higher polyunsaturated FA (PUFA), n-3 and n-6 FA, and a linolenic acid to cholesterolemic FA ratios, which implied a healthier FA profile. The SCD1 CC genotype was associated with a low cholesterolemic FA content, a high ratio of linolenic acid to cholesterolemic FA, and lower conjugated-linolenic acid and PUFA content. These results suggest the possible modulation of milk fat profiles, using specific genotypes, to improve the nutritional quality of dairy products.

Sex and depot differences in ex vivo adipose tissue fatty acid storage and glycerol-3-phosphate acyltransferase activity

PubMed Central

Morgan-Bathke, Maria; Chen, Liang; Oberschneider, Elisabeth; Harteneck, Debra

2015-01-01

Adipose tissue fatty acid storage varies according to sex, adipose tissue depot, and degree of fat gain. However, the mechanism(s) for these variations is not completely understood. We examined whether differences in adipose tissue glycerol-3-phosphate acyltransferase (GPAT) might play a role in these variations. We optimized an enzyme activity assay for total GPAT and GPAT1 activity in human adipose tissue and measured GPAT activity. Omental and subcutaneous adipose tissue was collected from obese and nonobese adults for measures of GPAT and GPAT1 activities, ex vivo palmitate storage, acyl-CoA synthetase (ACS) and diacylglycerol-acyltransferase (DGAT) activities, and CD36 protein. Total GPAT and GPAT1 activities decreased as a function of adipocyte size in both omental (r = −0.71, P = 0.003) and subcutaneous (r = −0.58, P = 0.04) fat. The relative contribution of GPAT1 to total GPAT activity increased as a function of adipocyte size, accounting for up to 60% of GPAT activity in those with the largest adipocytes. We found strong, positive correlations between ACS, GPAT, and DGAT activities for both sexes and depots (r values 0.58–0.91) and between these storage factors and palmitate storage rates into TAG (r values 0.55–0.90). We conclude that: 1) total GPAT activity decreases as a function of adipocyte size; 2) GPAT1 can account for over half of adipose GPAT activity in hypertrophic obesity; and 3) ACS, GPAT, and DGAT are coordinately regulated. PMID:25738782

Differential effects of low-fat and high-fat diets on fed-state hepatic triacylglycerol secretion, hepatic fatty acid profiles, and DGAT-1 protein expression in obese-prone Sprague-Dawley rats.

PubMed

Heden, Timothy D; Morris, E Matthew; Kearney, Monica L; Liu, Tzu-Wen; Park, Young-Min; Kanaley, Jill A; Thyfault, John P

2014-04-01

The purpose of this study was to compare the effects of short-term low-fat (LF) and high-fat (HF) diets on fed-state hepatic triacylglycerol (TAG) secretion, the content of proteins involved in TAG assembly and secretion, fatty acid oxidation (FAO), and the fatty acid profile of stored TAG. Using selectively bred obese-prone Sprague-Dawley rats, we directly measured fed-state hepatic TAG secretion, using Tyloxapol (a lipoprotein lipase inhibitor) and a standardized oral mixed meal (45% carbohydrate, 40% fat, 15% protein) bolus in animals fed a HF or LF diet for 2 weeks, after which the rats were maintained on their respective diet for 1 week (washout) prior to the liver being excised to measure protein content, FAO, and TAG fatty acid profiles. Hepatic DGAT-1 protein expression was ∼27% lower in HF- than in LF-fed animals (p < 0.05); the protein expression of all other molecules was similar in the 2 diets. The fed-state hepatic TAG secretion rate was ∼39% lower (p < 0.05) in HF- (4.62 ± 0.18 mmol·h(-1)) than in LF- (7.60 ± 0.57 mmol·h(-1)) fed animals. Hepatic TAG content was ∼2-fold higher (p < 0.05) in HF- (1.07 ± 0.15 nmol·g(-1) tissue) than in LF- (0.50 ± 0.16 nmol·g(-1) tissue) fed animals. In addition, the fatty acid profile of liver TAG in HF-fed animals closely resembled the diet, whereas in LF-fed animals, the fatty acid profile consisted of mostly de novo synthesized fatty acids. FAO was not altered by diet. LF and HF diets differentially alter fed-state hepatic TAG secretion, hepatic fatty acid profiles, and DGAT-1 protein expression.

Differential effects of low-fat and high-fat diets on fed-state hepatic triacylglycerol secretion, hepatic fatty acid profiles, and DGAT-1 protein expression in obese-prone Sprague–Dawley rats

PubMed Central

Heden, Timothy D.; Morris, E. Matthew; Kearney, Monica L.; Liu, Tzu-Wen; Park, Young-min; Kanaley, Jill A.; Thyfault, John P.

2015-01-01

The purpose of this study was to compare the effects of short-term low-fat (LF) and high-fat (HF) diets on fed-state hepatic triacylglycerol (TAG) secretion, the content of proteins involved in TAG assembly and secretion, fatty acid oxidation (FAO), and the fatty acid profile of stored TAG. Using selectively bred obese-prone Sprague–Dawley rats, we directly measured fed-state hepatic TAG secretion, using Tyloxapol (a lipoprotein lipase inhibitor) and a standardized oral mixed meal (45% carbohydrate, 40% fat, 15% protein) bolus in animals fed a HF or LF diet for 2 weeks, after which the rats were maintained on their respective diet for 1 week (washout) prior to the liver being excised to measure protein content, FAO, and TAG fatty acid profiles. Hepatic DGAT-1 protein expression was ~27% lower in HF- than in LF-fed animals (p < 0.05); the protein expression of all other molecules was similar in the 2 diets. The fed-state hepatic TAG secretion rate was ~39% lower (p < 0.05) in HF- (4.62 ± 0.18 mmol·h−1) than in LF- (7.60 ± 0.57 mmol·h−1) fed animals. Hepatic TAG content was ~2-fold higher (p < 0.05) in HF- (1.07 ± 0.15 nmol·g−1 tissue) than in LF- (0.50 ± 0.16 nmol·g−1 tissue) fed animals. In addition, the fatty acid profile of liver TAG in HF-fed animals closely resembled the diet, whereas in LF-fed animals, the fatty acid profile consisted of mostly de novo synthesized fatty acids. FAO was not altered by diet. LF and HF diets differentially alter fed-state hepatic TAG secretion, hepatic fatty acid profiles, and DGAT-1 protein expression. PMID:24669989

Effects of DGAT1 gene on meat and carcass fatness quality in Chinese commercial cattle.

PubMed

Yuan, Zhengrong; Li, Junya; Li, Jiao; Gao, Xue; Gao, Huijiang; Xu, Shangzhong

2013-02-01

This study was designed to investigate the candidate single nucleotide polymorphisms (SNPs) in the exon's region of bovine diacylglycerol O-acyltransferase (DGAT1) gene using bioinformatics and experimental methods. A total of 17 SNPs were screened from public data resources and DNA sequencing. Three SNPs (c.572A>G, c.1241C>T and c.1416T>G) of these candidate SNPs were genotyped by created restriction site-polymerase chain reaction (CRS-PCR) methods. The gene-specific SNP markers and their effects on meat and carcass fatness quality traits were evaluated in Chinese commercial cattle. The c.572A>G and c.1416T>G significantly effected on backfat thickness, longissimus muscle area, marbling score, fat color and Warner-Bratzler shear force. No significant association was detected between the c.1241C>T and measured traits. Results from this study suggested that the SNP markers may be effective for the marker-assisted selection of meat and carcass fatness quality traits, and added new evidence that DGAT1 gene is an important candidate gene for the improvement of meat and carcass fatness quality in beef cattle industry.

Response of genes involved in lipid metabolism in rat epididymal white adipose tissue to different fasting conditions after long-term fructose consumption.

PubMed

Li, Jin-Xiu; Ke, Da-Zhi; Yao, Ling; Wang, Shang; Ma, Peng; Liu, Li; Zuo, Guo-Wei; Jiang, Li-Rong; Wang, Jian-Wei

2017-03-04

There has been much concern regarding the dietary fructose contributes to the development of metabolic syndrome. High-fructose diet changes the expression of genes involved in lipid metabolism. Levels of a number of hepatic lipogenic enzymes are increased by a high-carbohydrate diet in fasted-refed model rats/mice. Both the white adipose tissue (WAT) and the liver play a key role in the maintenance of nutrient homeostasis. Here, the aim of this study was to analyze the expression of key genes related to lipid metabolism in epididymal WAT (eWAT) in response to different fasting condition after long-term chronic fructose consumption. Rats were fed standard chow supplemented with 10% w/v fructose solution for 5 weeks, and killed after chow-fasting and fructose withdrawal (fasting) or chow-fasting and continued fructose (fructose alone) for 14 h. Blood parameters and the expression of genes involved in fatty acid synthesis (ChREBP, SREBP-1c, FAS, SCD1), triglyceride biosynthesis (DGAT-1, DGAT-2) and lipid mobilization (ATGL, HSL) in eWAT were analyzed. In addition, mRNA levels of PPAR-γ, CD36 and LPL were also detected. As expected, fructose alone increased the mRNA expression of FAS, SCD1, and correspondingly decreased ATGL and HSL mRNA levels. However, ChREBP, DGAT-2, ATGL and HSL mRNA levels restored near to normal while FAS and SCD1 tend to basic level under fasting condition. The mRNA expression of SREBP-1c, PPAR-γ and LPL did not changed at any situations but CD36 mRNA decreased remarkably in fructose alone group. In conclusion, these findings demonstrate that genes involved in lipid metabolism in rat eWAT are varied in response to different fasting conditions after long-term fructose consumption. Copyright © 2017. Published by Elsevier Inc.

Influence of DGAT1 K232A polymorphism on milk fat percentage and fatty acid profiles in Romanian holstein cattle.

PubMed

Tăbăran, A; Balteanu, V A; Gal, E; Pusta, D; Mihaiu, R; Dan, S D; Tăbăran, A F; Mihaiu, M

2015-01-01

Milk and dairy products are considered the main sources of saturated fatty acids, which are a valuable source of nutrients in the human diet. Fat composition can be adjusted through guided nutrition of dairy animals but also through selective breeding. Recently, a dinucleotide substitution located in the exon 8 of the gene coding for acyl CoA: diacylglycerol acyltransferase 1 (DGAT1), that alters the amino acid sequence from a lysine to an alanine (p.Lys232Ala) in the mature protein, was shown to have a strong effect on milk fat content in some cattle breeds. Therefore, the objectives of this work were to study the occurrence of the DGAT1 p.Lys232Ala polymorphism in Romanian Holstein cattle and Romanian Buffalo breeds and to further investigate its possible influence on fat percentage and fatty acid profiles. The results obtained in this study show that in Romanian Holstein cattle the K allele is associated with increased fat percentage and higher levels of C16:0 and C18:0 fatty acids. The ratio of saturated fatty acids versus unsaturated fatty acids (SFA/UFA) was also higher in KK homozygous individuals, whereas the fractions of C14:0, unsaturated C18 decreased. The DGAT1 p.Lys232Ala polymorphism revealed a high genetic variance for fat percentage, unsaturated C18, C16:0, and SFA/UFA. Although the effect of this polymorphism was not so evident for short chain fatty acids such as C4:0-C8:0, it was significant for C14:0 fatty acids. We concluded that selective breeding of carriers of the A allele in Romanian Holsteins can contribute to improvement in unsaturated fatty acids content of milk. However, in buffalo, the lack of the A allele makes selection inapplicable because only the K allele, associated with higher saturated fatty acids contents in milk, was identified.

Improving the detection of pathways in genome-wide association studies by combined effects of SNPs from Linkage Disequilibrium blocks.

PubMed

Zhao, Huiying; Nyholt, Dale R; Yang, Yuanhao; Wang, Jihua; Yang, Yuedong

2017-06-14

Genome-wide association studies (GWAS) have successfully identified single variants associated with diseases. To increase the power of GWAS, gene-based and pathway-based tests are commonly employed to detect more risk factors. However, the gene- and pathway-based association tests may be biased towards genes or pathways containing a large number of single-nucleotide polymorphisms (SNPs) with small P-values caused by high linkage disequilibrium (LD) correlations. To address such bias, numerous pathway-based methods have been developed. Here we propose a novel method, DGAT-path, to divide all SNPs assigned to genes in each pathway into LD blocks, and to sum the chi-square statistics of LD blocks for assessing the significance of the pathway by permutation tests. The method was proven robust with the type I error rate >1.6 times lower than other methods. Meanwhile, the method displays a higher power and is not biased by the pathway size. The applications to the GWAS summary statistics for schizophrenia and breast cancer indicate that the detected top pathways contain more genes close to associated SNPs than other methods. As a result, the method identified 17 and 12 significant pathways containing 20 and 21 novel associated genes, respectively for two diseases. The method is available online by http://sparks-lab.org/server/DGAT-path .

JTT-553, a novel Acyl CoA:diacylglycerol acyltransferase (DGAT) 1 inhibitor, improves glucose metabolism in diet-induced obesity and genetic T2DM mice.

PubMed

Tomimoto, Daisuke; Okuma, Chihiro; Ishii, Yukihito; Kobayashi, Akio; Ohta, Takeshi; Kakutani, Makoto; Imanaka, Tsuneo; Ogawa, Nobuya

2015-09-01

Type 2 diabetes mellitus (T2DM) arises primarily due to lifestyle factors and genetics. A number of lifestyle factors are known to be important in the development of T2DM, including obesity. JTT-553, a novel Acyl CoA:diacylglycerol acyltransferase 1 inhibitor, reduced body weight depending on dietary fat in diet-induced obesity (DIO) rats in our previous study. Here, the effect of JTT-553 on glucose metabolism was evaluated using body weight reduction in T2DM mice. JTT-553 was repeatedly administered to DIO and KK-A(y) mice. JTT-553 reduced body weight gain and fat weight in both mouse models. In DIO mice, JTT-553 decreased insulin, non-esterified fatty acid (NEFA), total cholesterol (TC), and liver triglyceride (TG) plasma concentrations in non-fasting conditions. JTT-553 also improved insulin-dependent glucose uptake in adipose tissues and glucose intolerance in DIO mice. In KK-A(y) mice, JTT-553 decreased glucose, NEFA, TC and liver TG plasma concentrations in non-fasting conditions. JTT-553 also decreased glucose, insulin, and TC plasma concentrations in fasting conditions. In addition, JTT-553 decreased TNF-α mRNA levels and increased GLUT4 mRNA levels in adipose tissues in KK-A(y) mice. These results suggest that JTT-553 improves insulin resistance in adipose tissues and systemic glucose metabolism through reductions in body weight. Copyright © 2015 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

Novel LC/MS/MS and High-Throughput Mass Spectrometric Assays for Monoacylglycerol Acyltransferase Inhibitors.

PubMed

Qi, Jenson; Masucci, John A; Lang, Wensheng; Connelly, Margery A; Caldwell, Gary W; Petrounia, Ioanna; Kirkpatrick, Jennifer; Barnakov, Alexander N; Struble, Geoffrey; Miller, Robyn; Dzordzorine, Keli; Kuo, Gee-Hong; Gaul, Michael; Pocai, Alessandro; Lee, Seunghun

2017-04-01

Monoacylglycerol acyltransferase enzymes (MGAT1, MGAT2, and MGAT3) convert monoacylglycerol to diacylglycerol (DAG). MGAT1 and MGAT2 are both implicated in obesity-related metabolic diseases. Conventional MGAT enzyme assays use radioactive substrates, wherein the product of the MGAT-catalyzed reaction is usually resolved by time-consuming thin layer chromatography (TLC) analysis. Furthermore, microsomal membrane preparations typically contain endogenous diacylglycerol acyltransferase (DGAT) from the host cells, and these DGAT activities can further acylate DAG to form triglyceride (TG). Our mass spectrometry (liquid chromatography-tandem mass spectrometry, or LC/MS/MS) MGAT2 assay measures human recombinant MGAT2-catalyzed formation of didecanoyl-glycerol from 1-decanoyl-rac-glycerol and decanoyl-CoA, to produce predominantly 1,3-didecanoyl-glycerol. Unlike 1,2-DAG, 1,3-didecanoyl-glycerol is proved to be not susceptible to further acylation to TG. 1,3-Didecanoyl-glycerol product can be readily solubilized and directly subjected to high-throughput mass spectrometry (HTMS) without further extraction in a 384-well format. We also have established the LC/MS/MS MGAT activity assay in the intestinal microsomes from various species. Our assay is proved to be highly sensitive, and thus it allows measurement of endogenous MGAT activity in cell lysates and tissue preparations. The implementation of the HTMS MGAT activity assay has facilitated the robust screening and evaluation of MGAT inhibitors for the treatment of metabolic diseases.

Study of genetic variability in pigs after the traditional breeding program.

PubMed

Ferreira, I M; Vieira, G S; Braga, T F; Silva, T C F; Franco, M M; Antunes, R C

2017-09-21

Molecular markers are tools used to improve genetic gains. The objective of this study was to analyze the security of alleles of molecular marker genes for characteristics of economic interest in a pure population of pigs. After the extraction of DNA from the hair of 272 Large White matrices, the allele and genotype frequency of single nucleotide polymorphism was performed using the ARMS-PCR Multiplex technique in the DGAT1, LEPR, H-FABP, MC4R, and SREBF1 genes using RFLP-PCR for the GH gene. After capillary electrophoresis in an automated DNA sequencing of the DGAT1, LEPR, H-FABP, and SREBF1 genes, no polymorphisms were found. Only the MC4R marker presented 100% heterozygosity. For the GH gene, 209 of the initial population samples were genotyped. The PCR product (605 bp) was digested with the restriction enzyme DdeI, with fragments being of 335, 148, and 122 bp for the D 1 allele and 457 and 148 bp for the D 2 allele. The genotypic frequency obtained of D 1 D 2 was 88% and of D 2 D 2 was 22%. The D 1 allele presented a frequency of 11% and the D 2 allele of 89%. The high intensity of selection for commercial breeds justifies the absence or the low number of polymorphisms for the genes studied.

The expression and regulation of enzymes mediating the biosynthesis of triglycerides and phospholipids in keratinocytes/epidermis

PubMed Central

Feingold, Kenneth R

2011-01-01

Triglycerides and phospholipids play an important role in epidermal permability barrier formation and function. They are synthesized de novo in the epidermis via the glycerol-3-phosphate pathway, catalyzed sequentially by a group of enzymes that have multiple isoforms including glycerol-3-phosphate acyltransferase (GPAT), 1-acylglycerol-3-phosphate acyltransferase (AGPAT), Lipin and diacylglycerol acyltransferase (DGAT). Here we review the current knowledge of GPAT, AGPAT, Lipin and DGAT enzymes in keratinocytes/epidermis focusing on the expression levels of the various isoforms and their localization in mouse epidermis. Additionally, the factors regulating their gene expression, including calcium induced differentiation, PPAR and LXR activators, and the effect of acute permeability barrier disruption will be discussed. PMID:21695015

Microscale High-Throughput Experimentation as an Enabling Technology in Drug Discovery: Application in the Discovery of (Piperidinyl)pyridinyl-1H-benzimidazole Diacylglycerol Acyltransferase 1 Inhibitors.

PubMed

Cernak, Tim; Gesmundo, Nathan J; Dykstra, Kevin; Yu, Yang; Wu, Zhicai; Shi, Zhi-Cai; Vachal, Petr; Sperbeck, Donald; He, Shuwen; Murphy, Beth Ann; Sonatore, Lisa; Williams, Steven; Madeira, Maria; Verras, Andreas; Reiter, Maud; Lee, Claire Heechoon; Cuff, James; Sherer, Edward C; Kuethe, Jeffrey; Goble, Stephen; Perrotto, Nicholas; Pinto, Shirly; Shen, Dong-Ming; Nargund, Ravi; Balkovec, James; DeVita, Robert J; Dreher, Spencer D

2017-05-11

Miniaturization and parallel processing play an important role in the evolution of many technologies. We demonstrate the application of miniaturized high-throughput experimentation methods to resolve synthetic chemistry challenges on the frontlines of a lead optimization effort to develop diacylglycerol acyltransferase (DGAT1) inhibitors. Reactions were performed on ∼1 mg scale using glass microvials providing a miniaturized high-throughput experimentation capability that was used to study a challenging S N Ar reaction. The availability of robust synthetic chemistry conditions discovered in these miniaturized investigations enabled the development of structure-activity relationships that ultimately led to the discovery of soluble, selective, and potent inhibitors of DGAT1.

Expression of type 2 diacylglycerol acyltransferse gene DGTT1 from Chlamydomonas reinhardtii enhances lipid production in Scenedesmus obliquus.

PubMed

Chen, Chun-Yen; Kao, Ai-Ling; Tsai, Zheng-Chia; Chow, Te-Jin; Chang, Hsin-Yueh; Zhao, Xin-Qing; Chen, Po-Ting; Su, Hsiang-Yen; Chang, Jo-Shu

2016-03-01

Microalgal strains of Scenedesmus obliquus have the great potential for the production of biofuels, CO2 fixation, and bioremediation. However, metabolic engineering of S. obliquus to improve their useful phenotypes are still not fully developed. In this study, S. obliquus strain CPC2 was genetically engineered to promote the autotrophic growth and lipid productivity. The overexpression plasmid containing the type 2 diacylglycerol acyltransferse (DGAT) gene DGTT1 from Chlamydomonas reinhardtii was constructed and transformed into S. obliquus CPC2, and the positive transformants were obtained. The expression of DGTT1 gene was confirmed by reverse transcription PCR analysis. Enhanced lipid content of the transformant S. obliquus CPC2-G1 by nearly two-fold was observed. The biomass concentration of the recombinant strains was also 29% higher than that of the wild-type strain. Furthermore, the recombinant strain CPC2-G1 was successfully grown in 40 L tubular type photobioreactor and open pond system in an outdoor environment. The lipid content, biomass concentration, and biomass productivity obtained from 40 L tubular PBR were 127.8% 20.0%, and 232.6% higher than those obtained from the wild-type strain. The major aim of this work is to develop a tool to genetically engineer an isolated S. obliquus strain for the desired purpose. This is the first report that genetic engineering of S. obliquus has been successful employed to improve both the microalgal cell growth and the lipid production. Copyright © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Role of Wax Ester Synthase/Acyl Coenzyme A:Diacylglycerol Acyltransferase in Oleaginous Streptomyces sp. Strain G25

PubMed Central

Röttig, Annika; Strittmatter, Carl Simon; Schauer, Jennifer; Hiessl, Sebastian; Daniel, Rolf

2016-01-01

ABSTRACT Recently, we isolated a novel Streptomyces strain which can accumulate extraordinarily large amounts of triacylglycerol (TAG) and consists of 64% fatty acids (dry weight) when cultivated with glucose and 50% fatty acids (dry weight) when cultivated with cellobiose. To identify putative gene products responsible for lipid storage and cellobiose utilization, we analyzed its draft genome sequence. A single gene encoding a wax ester synthase/acyl coenzyme A (CoA):diacylglycerol acyltransferase (WS/DGAT) was identified and heterologously expressed in Escherichia coli. The purified enzyme AtfG25 showed acyltransferase activity with C12- or C16-acyl-CoA, C12 to C18 alcohols, or dipalmitoyl glycerol. This acyltransferase exhibits 24% amino acid identity to the model enzyme AtfA from Acinetobacter baylyi but has high sequence similarities to WS/DGATs from other Streptomyces species. To investigate the impact of AtfG25 on lipid accumulation, the respective gene, atfG25, was inactivated in Streptomyces sp. strain G25. However, cells of the insertion mutant still exhibited DGAT activity and were able to store TAG, albeit in lower quantities and at lower rates than the wild-type strain. These findings clearly indicate that AtfG25 has an important, but not exclusive, role in TAG biosynthesis in the novel Streptomyces isolate and suggest the presence of alternative metabolic pathways for lipid accumulation which are discussed in the present study. IMPORTANCE A novel Streptomyces strain was isolated from desert soil, which represents an extreme environment with high temperatures, frequent drought, and nutrient scarcity. We believe that these harsh conditions promoted the development of the capacity for this strain to accumulate extraordinarily large amounts of lipids. In this study, we present the analysis of its draft genome sequence with a special focus on enzymes potentially involved in its lipid storage. Furthermore, the activity and importance of the detected acyltransferase were studied. As discussed in this paper, and in contrast to many other bacteria, streptomycetes seem to possess a complex metabolic network to synthesize lipids, whereof crucial steps are still largely unknown. This paper therefore provides insights into a range of topics, including extremophile bacteria, the physiology of lipid accumulation, and the biotechnological production of bacterial lipids. PMID:27474711

Bioengineering recombinant tung tree diacylglycerol acyltransferases

USDA-ARS?s Scientific Manuscript database

Understanding plant oil biosynthesis will help to create new oilseed crops with value-added properties to replace petroleum-based compounds. Diacylglycerol acyltransferases (DGATs) are key enzymes catalyzing the last step of triacylglycerol (TAG) biosynthesis in eukaryotes. Plants and animals defici...

Engineering E. coli for triglyceride accumulation through native and heterologous metabolic reactions.

PubMed

Rucker, Joanna; Paul, Julie; Pfeifer, Blaine A; Lee, Kyongbum

2013-03-01

Triglycerides, traditionally sourced from plant oils, are heavily used in both industrial and healthcare applications. Commercially significant products produced from triglycerides include biodiesel, lubricants, moisturizers, and oils for cooking and dietary supplements. The need to rely upon plant-based production, however, raises concerns of increasing demand and sustainability. The reliance on crop yields and a strong demand for triglycerides provides motivation to engineer production from a robust microbial platform. In this study, Escherichia coli was engineered to synthesize and accumulate triglycerides. Triglycerides were produced from cell wall phospholipid precursors through engineered expression of two enzymes, phosphatidic acid phosphatase (PAP) and diacylglycerol acyltransferase (DGAT). A liquid chromatography-mass spectrometry (LC-MS) method was developed to analyze the production of triglycerides by the engineered E. coli strains. This proof-of-concept study demonstrated a yield of 1.1 mg/L triglycerides (2 g/L dry cell weight) in lysogeny broth medium containing 5 g/L glucose at 8 h following induction of PAP and DGAT expression. LC-MS results also demonstrated that the intracellular triglyceride composition of E. coli was highly conserved. Triglycerides containing the fatty acid distributions 16:0/16:0/16:1, 16:0/16:0/18:1, and 18:1/16:0/16:1 were found in highest concentrations and represent ∼70 % of triglycerides observed.

Intestinal triacylglycerol synthesis in fat absorption and systemic energy metabolism

PubMed Central

Yen, Chi-Liang Eric; Nelson, David W.; Yen, Mei-I

2015-01-01

The intestine plays a prominent role in the biosynthesis of triacylglycerol (triglyceride; TAG). Digested dietary TAG is repackaged in the intestine to form the hydrophobic core of chylomicrons, which deliver metabolic fuels, essential fatty acids, and other lipid-soluble nutrients to the peripheral tissues. By controlling the flux of dietary fat into the circulation, intestinal TAG synthesis can greatly impact systemic metabolism. Genes encoding many of the enzymes involved in TAG synthesis have been identified. Among TAG synthesis enzymes, acyl-CoA:monoacylglycerol acyltransferase 2 and acyl-CoA:diacylglycerol acyltransferase (DGAT)1 are highly expressed in the intestine. Their physiological functions have been examined in the context of whole organisms using genetically engineered mice and, in the case of DGAT1, specific inhibitors. An emerging theme from recent findings is that limiting the rate of TAG synthesis in the intestine can modulate gut hormone secretion, lipid metabolism, and systemic energy balance. The underlying mechanisms and their implications for humans are yet to be explored. Pharmacological inhibition of TAG hydrolysis in the intestinal lumen has been employed to combat obesity and associated disorders with modest efficacy and unwanted side effects. The therapeutic potential of inhibiting specific enzymes involved in intestinal TAG synthesis warrants further investigation. PMID:25231105

Intestinal triacylglycerol synthesis in fat absorption and systemic energy metabolism.

PubMed

Yen, Chi-Liang Eric; Nelson, David W; Yen, Mei-I

2015-03-01

The intestine plays a prominent role in the biosynthesis of triacylglycerol (triglyceride; TAG). Digested dietary TAG is repackaged in the intestine to form the hydrophobic core of chylomicrons, which deliver metabolic fuels, essential fatty acids, and other lipid-soluble nutrients to the peripheral tissues. By controlling the flux of dietary fat into the circulation, intestinal TAG synthesis can greatly impact systemic metabolism. Genes encoding many of the enzymes involved in TAG synthesis have been identified. Among TAG synthesis enzymes, acyl-CoA:monoacylglycerol acyltransferase 2 and acyl-CoA:diacylglycerol acyltransferase (DGAT)1 are highly expressed in the intestine. Their physiological functions have been examined in the context of whole organisms using genetically engineered mice and, in the case of DGAT1, specific inhibitors. An emerging theme from recent findings is that limiting the rate of TAG synthesis in the intestine can modulate gut hormone secretion, lipid metabolism, and systemic energy balance. The underlying mechanisms and their implications for humans are yet to be explored. Pharmacological inhibition of TAG hydrolysis in the intestinal lumen has been employed to combat obesity and associated disorders with modest efficacy and unwanted side effects. The therapeutic potential of inhibiting specific enzymes involved in intestinal TAG synthesis warrants further investigation. Copyright © 2015 by the American Society for Biochemistry and Molecular Biology, Inc.

Tobacco as a production platform for biofuel: overexpression of Arabidopsis DGAT and LEC2 genes increases accumulation and shifts the composition of lipids in green biomass.

PubMed

Andrianov, Vyacheslav; Borisjuk, Nikolai; Pogrebnyak, Natalia; Brinker, Anita; Dixon, Joseph; Spitsin, Sergei; Flynn, John; Matyszczuk, Paulina; Andryszak, Karolina; Laurelli, Marilyn; Golovkin, Maxim; Koprowski, Hilary

2010-04-01

When grown for energy production instead for smoking, tobacco can generate a large amount of inexpensive biomass more efficiently than almost any other agricultural crop. Tobacco possesses potent oil biosynthesis machinery and can accumulate up to 40% of seed weight in oil. In this work, we explored two metabolic engineering approaches to enhance the oil content in tobacco green tissues for potential biofuel production. First, an Arabidopsis thaliana gene diacylglycerol acyltransferase (DGAT) coding for a key enzyme in triacylglycerol (TAG) biosynthesis, was expressed in tobacco under the control of a strong ribulose-biphosphate carboxylase small subunit promoter. This modification led to up to a 20-fold increase in TAG accumulation in tobacco leaves and translated into an overall of about a twofold increase in extracted fatty acids (FA) up to 5.8% of dry biomass in Nicotiana tabacum cv Wisconsin, and up to 6% in high-sugar tobacco variety NC-55. Modified tobacco plants also contained elevated amounts of phospholipids. This increase in lipids was accompanied by a shift in the FA composition favourable for their utilization as biodiesel. Second, we expressed in tobacco Arabidopsis gene LEAFY COTYLEDON 2 (LEC2), a master regulator of seed maturation and seed oil storage under the control of an inducible Alc promoter. Stimulation of LEC2 expression in mature tobacco plants by acetaldehyde led to the accumulation of up to 6.8% per dry weight of total extracted FA. The obtained data reveal the potential of metabolically modified plant biomass for the production of biofuel.

Optimizing human hepatocyte models for metabolic phenotype and function: effects of treatment with dimethyl sulfoxide (DMSO).

PubMed

Nikolaou, Nikolaos; Green, Charlotte J; Gunn, Pippa J; Hodson, Leanne; Tomlinson, Jeremy W

2016-11-01

Primary human hepatocytes are considered to be the "gold standard" cellular model for studying hepatic fatty acid and glucose metabolism; however, they come with limitations. Although the HepG2 cell line retains many of the primary hepatocyte metabolic functions they have a malignant origin and low rates of triglyceride secretion. The aim of this study was to investigate whether dimethyl sulfoxide supplementation in the media of HepG2 cells would enhance metabolic functionality leading to the development of an improved in vitro cell model that closely recapitulates primary human hepatocyte metabolism. HepG2 cells were cultured in media containing 1% dimethyl sulfoxide for 2, 4, 7, 14, and 21 days. Gene expression, protein levels, intracellular triglyceride, and media concentrations of triglyceride, urea, and 3-hydroxybutyrate concentrations were measured. Dimethyl sulfoxide treatment altered the expression of genes involved in lipid (FAS, ACC1, ACC2, DGAT1, DGAT2, SCD) and glucose (PEPCK, G6Pase) metabolism as well as liver functionality (albumin, alpha-1-antitrypsin, AFP). mRNA changes were paralleled by alterations at the protein level. DMSO treatment decreased intracellular triglyceride content and lactate production and increased triglyceride and 3-hydroxybutyrate concentrations in the media in a time-dependent manner. We have demonstrated that the addition of 1% dimethyl sulfoxide to culture media changes the metabolic phenotype of HepG2 cells toward a more primary human hepatocyte phenotype. This will enhance the currently available in vitro model systems for the study of hepatocyte biology related to pathological processes that contribute to disease and their response to specific therapeutic interventions. © 2016 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

Genome-wide meta-analyses identify novel loci associated with n-3 and n-6 polyunsaturated fatty acid levels in Chinese and European-ancestry populations.

PubMed

Hu, Yao; Li, Huaixing; Lu, Ling; Manichaikul, Ani; Zhu, Jingwen; Chen, Yii-Der I; Sun, Liang; Liang, Shuang; Siscovick, David S; Steffen, Lyn M; Tsai, Michael Y; Rich, Stephen S; Lemaitre, Rozenn N; Lin, Xu

2016-03-15

Epidemiological studies suggest that levels of n-3 and n-6 long-chain polyunsaturated fatty acids are associated with risk of cardio-metabolic outcomes across different ethnic groups. Recent genome-wide association studies in populations of European ancestry have identified several loci associated with plasma and/or erythrocyte polyunsaturated fatty acids. To identify additional novel loci, we carried out a genome-wide association study in two population-based cohorts consisting of 3521 Chinese participants, followed by a trans-ethnic meta-analysis with meta-analysis results from 8962 participants of European ancestry. Four novel loci (MYB, AGPAT4, DGAT2 and PPT2) reached genome-wide significance in the trans-ethnic meta-analysis (log10(Bayes Factor) ≥ 6). Of them, associations of MYB and AGPAT4 with docosatetraenoic acid (log10(Bayes Factor) = 11.5 and 8.69, respectively) also reached genome-wide significance in the Chinese-specific genome-wide association analyses (P = 4.15 × 10(-14) and 4.30 × 10(-12), respectively), while associations of DGAT2 with gamma-linolenic acid (log10(Bayes Factor) = 6.16) and of PPT2 with docosapentaenoic acid (log10(Bayes Factor) = 6.24) were nominally significant in both Chinese- and European-specific genome-wide association analyses (P ≤ 0.003). We also confirmed previously reported loci including FADS1, NTAN1, NRBF2, ELOVL2 and GCKR. Different effect sizes in FADS1 and independent association signals in ELOVL2 were observed. These results provide novel insight into the genetic background of polyunsaturated fatty acids and their differences between Chinese and European populations. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Evolution and taxonomic split of the model grass Brachypodium distachyon

PubMed Central

Catalán, Pilar; Müller, Jochen; Hasterok, Robert; Jenkins, Glyn; Mur, Luis A. J.; Langdon, Tim; Betekhtin, Alexander; Siwinska, Dorota; Pimentel, Manuel; López-Alvarez, Diana

2012-01-01

Background and Aims Brachypodium distachyon is being widely investigated across the world as a model plant for temperate cereals. This annual plant has three cytotypes (2n =  10, 20, 30) that are still regarded as part of a single species. Here, a multidisciplinary study has been conducted on a representative sampling of the three cytotypes to investigate their evolutionary relationships and origins, and to elucidate if they represent separate species. Methods Statistical analyses of 15 selected phenotypic traits were conducted in individuals from 36 lines or populations. Cytogenetic analyses were performed through flow cytometry, fluorescence in situ hybridization (FISH) with genomic (GISH) and multiple DNA sequences as probes, and comparative chromosome painting (CCP). Phylogenetic analyses were based on two plastid (ndhF, trnLF) and five nuclear (ITS, ETS, CAL, DGAT, GI) genes from different Brachypodium lineages, whose divergence times and evolutionary rates were estimated. Key Results The phenotypic analyses detected significant differences between the three cytotypes and demonstrated stability of characters in natural populations. Genome size estimations, GISH, FISH and CCP confirmed that the 2n = 10 and 2n = 20 cytotypes represent two different diploid taxa, whereas the 2n = 30 cytotype represents the allotetraploid derived from them. Phylogenetic analysis demonstrated that the 2n = 20 and 2n = 10 cytotypes emerged from two independent lineages that were, respectively, the maternal and paternal genome donors of the 2n = 30 cytotype. The 2n = 20 lineage was older and mutated significantly faster than the 2n = 10 lineage and all the core perennial Brachypodium species. Conclusions The substantial phenotypic, cytogenetic and molecular differences detected among the three B. distachyon sensu lato cytotypes are indicative of major speciation processes within this complex that allow their taxonomic separation into three distinct species. We have kept the name B. distachyon for the 2n = 10 cytotype and have described two novel species as B. stacei and B. hybridum for, respectively, the 2n = 20 and 2n = 30 cytotypes. PMID:22213013

A pharmacologic increase in activity of plasma transaminase derived from small intestine in animals receiving an acyl CoA: diacylglycerol transferase (DGAT) 1 inhibitor.

PubMed

Yokoyama, Hideaki; Kobayashi, Akio; Kondo, Kazuma; Oshida, Shin-Ichi; Takahashi, Tadakazu; Masuyama, Taku; Shoda, Toshiyuki; Sugai, Shoichiro

2018-01-01

Acyl CoA: diacylglycerol acyltransferase (DGAT) 1 is an enzyme that catalyzes the re-synthesis of triglycerides (TG) from free fatty acids and diacylglycerol. JTT-553 is a DGAT1 inhibitor and exhibits its pharmacological action (inhibition of re-synthesis of TG) in the enterocytes of the small intestine leading to suppression of a postprandial elevation of plasma lipids. After repeated oral dosing JTT-553 in rats and monkeys, plasma transaminase levels were increased but there were neither changes in other hepatic function parameters nor histopathological findings suggestive of hepatotoxicity. Based on the results of exploratory studies for investigation of the mechanism of the increase in transaminase levels, plasma transaminase levels were increased after dosing JTT-553 only when animals were fed after dosing and a main factor in the diet contributing to the increase in plasma transaminase levels was lipids. After dosing JTT-553, transaminase levels were increased in the small intestine but not in the liver, indicating that the origin of transaminase increased in the plasma was not the liver but the small intestine where JTT-553 exhibits its pharmacological action. The increase in small intestinal transaminase levels was due to increased enzyme protein synthesis and was suppressed by inhibiting fatty acid-transport to the enterocytes. In conclusion, the JTT-553-related increase in plasma transaminase levels is considered not to be due to release of the enzymes from injured cells into the circulation but to be phenomena resulting from enhancement of enzyme protein synthesis in the small intestine due to the pharmacological action of JTT-553 in this organ.

Tracking synthesis and turnover of triacylglycerol in leaves

PubMed Central

Tjellström, Henrik; Strawsine, Merissa; Ohlrogge, John B.

2015-01-01

Triacylglycerol (TAG), typically represents <1% of leaf glycerolipids but can accumulate under stress and other conditions or if leaves are supplied with fatty acids, or in plants transformed with regulators or enzymes of lipid metabolism. To better understand the metabolism of TAG in leaves, pulse–chase radiolabelling experiments were designed to probe its synthesis and turnover. When Arabidopsis leaves were incubated with [14C]lauric acid (12:0), a major initial product was [14C]TAG. Thus, despite low steady-state levels, leaves possess substantial TAG biosynthetic capacity. The contributions of diacylglycerol acyltransferase1 and phospholipid:diacylglycerol acyltransferase1 to leaf TAG synthesis were examined by labelling of dgat1 and pdat1 mutants. The dgat1 mutant displayed a major (76%) reduction in [14C]TAG accumulation whereas pdat1 TAG labelling was only slightly reduced. Thus, DGAT1 has a principal role in TAG biosynthesis in young leaves. During a 4h chase period, radioactivity in TAG declined 70%, whereas the turnover of [14C]acyl chains of phosphatidylcholine (PC) and other polar lipids was much lower. Sixty percent of [14C]12:0 was directly incorporated into glycerolipids without modification, whereas 40% was elongated and desaturated to 16:0 and 18:1 by plastids. The unmodified [14C]12:0 and the plastid products of [14C]12:0 metabolism entered different pathways. Although plastid-modified 14C-labelled products accumulated in monogalactosyldiacylglycerol, PC, phosphatidylethanolamine, and diacylglcerol (DAG), there was almost no accumulation of [14C]16:0 and [14C]18:1 in TAG. Because DAG and acyl-CoA are direct precursors of TAG, the differential labelling of polar glycerolipids and TAG by [14C]12:0 and its plastid-modified products provides evidence for multiple subcellular pools of both acyl-CoA and DAG. PMID:25609824

Functional assessment of plant and microalgal lipid pathway genes in yeast to enhance microbial industrial oil production.

PubMed

Peng, Huadong; Moghaddam, Lalehvash; Brinin, Anthony; Williams, Brett; Mundree, Sagadevan; Haritos, Victoria S

2018-03-01

As promising alternatives to fossil-derived oils, microbial lipids are important as industrial feedstocks for biofuels and oleochemicals. Our broad aim is to increase lipid content in oleaginous yeast through expression of lipid accumulation genes and use Saccharomyces cerevisiae to functionally assess genes obtained from oil-producing plants and microalgae. Lipid accumulation genes DGAT (diacylglycerol acyltransferase), PDAT (phospholipid: diacylglycerol acyltransferase), and ROD1 (phosphatidylcholine: diacylglycerol choline-phosphotransferase) were separately expressed in yeast and lipid production measured by fluorescence, solvent extraction, thin layer chromatography, and gas chromatography (GC) of fatty acid methyl esters. Expression of DGAT1 from Arabidopsis thaliana effectively increased total fatty acids by 1.81-fold above control, and ROD1 led to increased unsaturated fatty acid content of yeast lipid. The functional assessment approach enabled the fast selection of candidate genes for metabolic engineering of yeast for production of lipid feedstocks. © 2017 International Union of Biochemistry and Molecular Biology, Inc.

Genetic enhancement of oil content in potato tuber (Solanum tuberosum L.) through an integrated metabolic engineering strategy.

PubMed

Liu, Qing; Guo, Qigao; Akbar, Sehrish; Zhi, Yao; El Tahchy, Anna; Mitchell, Madeline; Li, Zhongyi; Shrestha, Pushkar; Vanhercke, Thomas; Ral, Jean-Philippe; Liang, Guolu; Wang, Ming-Bo; White, Rosemary; Larkin, Philip; Singh, Surinder; Petrie, James

2017-01-01

Potato tuber is a high yielding food crop known for its high levels of starch accumulation but only negligible levels of triacylglycerol (TAG). In this study, we evaluated the potential for lipid production in potato tubers by simultaneously introducing three transgenes, including WRINKLED 1 (WRI1), DIACYLGLYCEROL ACYLTRANSFERASE 1 (DGAT1) and OLEOSIN under the transcriptional control of tuber-specific (patatin) and constitutive (CaMV-35S) promoters. This coordinated metabolic engineering approach resulted in over a 100-fold increase in TAG accumulation to levels up to 3.3% of tuber dry weight (DW). Phospholipids and galactolipids were also found to be significantly increased in the potato tuber. The increase of lipids in these transgenic tubers was accompanied by a significant reduction in starch content and an increase in soluble sugars. Microscopic examination revealed that starch granules in the transgenic tubers had more irregular shapes and surface indentations when compared with the relatively smooth surfaces of wild-type starch granules. Ultrastructural examination of lipid droplets showed their close proximity to endoplasmic reticulum and mitochondria, which may indicate a dynamic interaction with these organelles during the processes of lipid biosynthesis and turnover. Increases in lipid levels were also observed in the transgenic potato leaves, likely due to the constitutive expression of DGAT1 and incomplete tuber specificity of the patatin promoter. This study represents an important proof-of-concept demonstration of oil increase in tubers and provides a model system to further study carbon reallocation during development of nonphotosynthetic underground storage organs. © 2016 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

Dietary salecan reverts partially the metabolic gene expressions and NMR-based metabolomic profiles from high-fat-diet-induced obese rats.

PubMed

Sun, Qi; Li, Minghui; Yang, Xiao; Xu, Xi; Wang, Junsong; Zhang, Jianfa

2017-09-01

Previous studies suggest that dietary salecan (a water-soluble β-glucan) effectively reduces high-fat-diet-induced adiposity through disturbing bile-acid-promoted emulsification in mice. However, the effects of salecan on metabolic genes and metabolites involved in lipid accumulation are mostly unknown. Here, we confirmed that dietary 3% and 6% salecan for 4 weeks markedly decreased fat accumulation in liver and adipose tissue in high-fat-diet rats, displaying a decrease in mRNA levels of SREBP1-C, FAS, SCD1 and ACC1 involved in de novo lipogenesis and a reduction of levels of GPAT1, DGAT1 and DGAT2 related to triglyceride synthesis. Dietary salecan also increased the mRNA levels of PPARα and CYP7A1, which are related to fatty acid oxidation and cholesterol decomposition, respectively. In the 1 H nuclear magnetic resonance metabolomic analysis, both the serum and liver metabolite profiles differed among the control groups, and the metabolic profiles of the salecan groups were shifted toward that of the low-fat-diet group. Metabolites analysis showed that salecan significantly increased hepatic glutathione and betaine levels which are related to regulation of cellular reactive oxygen species. These data demonstrate that dietary salecan not only disturbed fat digestion and absorption but also influenced lipid accumulation and metabolism in diet-induced obesity. Copyright © 2017 Elsevier Inc. All rights reserved.

Study of Valproic Acid-Enhanced Hepatocyte Steatosis

PubMed Central

Chang, Renin; Chou, Mei-Chia; Hung, Li-Ying; Wang, Mu-En; Hsu, Meng-Chieh; Chiu, Chih-Hsien

2016-01-01

Valproic acid (VPA) is one of the most widely used antiepilepsy drugs. However, several side effects, including weight gain and fatty liver, have been reported in patients following VPA treatment. In this study, we explored the molecular mechanisms of VPA-induced hepatic steatosis using FL83B cell line-based in vitro model. Using fluorescent lipid staining technique, we found that VPA enhanced oleic acid- (OLA-) induced lipid accumulation in a dose-dependent manner in hepatocytes; this may be due to upregulated lipid uptake, triacylglycerol (TAG) synthesis, and lipid droplet formation. Real-time PCR results showed that, following VPA treatment, the expression levels of genes encoding cluster of differentiation 36 (Cd36), low-density lipoprotein receptor-related protein 1 (Lrp1), diacylglycerol acyltransferase 2 (Dgat2), and perilipin 2 (Plin2) were increased, that of carnitine palmitoyltransferase I a (Cpt1a) was not affected, and those of acetyl-Co A carboxylase α (Acca) and fatty acid synthase (Fasn) were decreased. Furthermore, using immunofluorescence staining and flow cytometry analyses, we found that VPA also induced peroxisome proliferator-activated receptor γ (PPARγ) nuclear translocation and increased levels of cell-surface CD36. Based on these results, we propose that VPA may enhance OLA-induced hepatocyte steatosis through the upregulation of PPARγ- and CD36-dependent lipid uptake, TAG synthesis, and lipid droplet formation. PMID:27034954

Simple method to detect triacylglycerol biosynthesis in a yeast-based recombinant system

USDA-ARS?s Scientific Manuscript database

Standard methods to quantify the activity of triacylglycerol (TAG) synthesizing enzymes DGAT and PDAT (TAG-SE) require a sensitive but rather arduous laboratory assay based on radio-labeled substrates. Here we describe two straightforward methods to detect TAG production in baker’s yeast Saccharomyc...

Early-onset pediatric atopic dermatitis is characterized by TH2/TH17/TH22-centered inflammation and lipid alterations.

PubMed

Brunner, Patrick M; Israel, Ariel; Zhang, Ning; Leonard, Alexandra; Wen, Huei-Chi; Huynh, Thy; Tran, Gary; Lyon, Sarah; Rodriguez, Giselle; Immaneni, Supriya; Wagner, Annette; Zheng, Xiuzhong; Estrada, Yeriel D; Xu, Hui; Krueger, James G; Paller, Amy S; Guttman-Yassky, Emma

2018-06-01

Although atopic dermatitis (AD) often starts in early childhood, detailed tissue profiling of early-onset AD in children is lacking, hindering therapeutic development for this patient population with a particularly high unmet need for better treatments. We sought to globally profile the skin of infants with AD compared with that of adults with AD and healthy control subjects. We performed microarray, RT-PCR, and fluorescence microscopy studies in infants and young children (<5 years old) with early-onset AD (<6 months disease duration) compared with age-matched control subjects and adults with longstanding AD. Transcriptomic analyses revealed profound differences between pediatric patients with early-onset versus adult patients with longstanding AD in not only lesional but also nonlesional tissues. Although both patient populations harbored T H 2-centered inflammation, pediatric AD also showed significant T H 17/T H 22 skewing but lacked the T H 1 upregulation that characterizes adult AD. Pediatric AD exhibited relatively normal expression of epidermal differentiation and cornification products, which is downregulated in adults with AD. Defects in the lipid barrier (eg, ELOVL fatty acid elongase 3 [ELOVL3] and diacylglycerol o-acyltransferase 2 [DGAT2]) and tight junction regulation (eg, claudins 8 and 23) were evident in both groups. However, some lipid-associated mediators (eg, fatty acyl-CoA reductase 2 and fatty acid 2-hydroxylase) showed preferential downregulation in pediatric AD, and lipid barrier genes (FA2H and DGAT2) showed inverse correlations with transepidermal water loss, a functional measure of the epidermal barrier. Skin samples from children and adult patients with AD share lipid metabolism and tight junction alterations, but epidermal differentiation complex defects are only present in adult AD, potentially resulting from chronic immune aberration that is not yet present in early-onset disease. Copyright © 2018 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

Tracking synthesis and turnover of triacylglycerol in leaves.

PubMed

Tjellström, Henrik; Strawsine, Merissa; Ohlrogge, John B

2015-03-01

Triacylglycerol (TAG), typically represents <1% of leaf glycerolipids but can accumulate under stress and other conditions or if leaves are supplied with fatty acids, or in plants transformed with regulators or enzymes of lipid metabolism. To better understand the metabolism of TAG in leaves, pulse-chase radiolabelling experiments were designed to probe its synthesis and turnover. When Arabidopsis leaves were incubated with [(14)C]lauric acid (12:0), a major initial product was [(14)C]TAG. Thus, despite low steady-state levels, leaves possess substantial TAG biosynthetic capacity. The contributions of diacylglycerol acyltransferase1 and phospholipid:diacylglycerol acyltransferase1 to leaf TAG synthesis were examined by labelling of dgat1 and pdat1 mutants. The dgat1 mutant displayed a major (76%) reduction in [(14)C]TAG accumulation whereas pdat1 TAG labelling was only slightly reduced. Thus, DGAT1 has a principal role in TAG biosynthesis in young leaves. During a 4h chase period, radioactivity in TAG declined 70%, whereas the turnover of [(14)C]acyl chains of phosphatidylcholine (PC) and other polar lipids was much lower. Sixty percent of [(14)C]12:0 was directly incorporated into glycerolipids without modification, whereas 40% was elongated and desaturated to 16:0 and 18:1 by plastids. The unmodified [(14)C]12:0 and the plastid products of [(14)C]12:0 metabolism entered different pathways. Although plastid-modified (14)C-labelled products accumulated in monogalactosyldiacylglycerol, PC, phosphatidylethanolamine, and diacylglcerol (DAG), there was almost no accumulation of [(14)C]16:0 and [(14)C]18:1 in TAG. Because DAG and acyl-CoA are direct precursors of TAG, the differential labelling of polar glycerolipids and TAG by [(14)C]12:0 and its plastid-modified products provides evidence for multiple subcellular pools of both acyl-CoA and DAG. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Tracking synthesis and turnover of triacylglycerol in leaves

DOE PAGES

Tjellstrom, Henrik; Strawsine, Merissa; Ohlrogge, John B.

2015-01-21

Triacylglycerol (TAG), typically represents <1% of leaf glycerolipids but can accumulate under stress and other conditions or if leaves are supplied with fatty acids, or in plants transformed with regulators or enzymes of lipid metabolism. To better understand the metabolism of TAG in leaves, pulse-chase radiolabelling experiments were designed to probe its synthesis and turnover. When Arabidopsis leaves were incubated with [ 14C]lauric acid (12:0), a major initial product was [ 14C]TAG. Thus, despite low steady-state levels, leaves possess substantial TAG biosynthetic capacity. The contributions of diacylglycerol acyltransferase1 and phospholipid:diacylglycerol acyltransferase1 to leaf TAG synthesis were examined by labelling ofmore » dgat1 and pdat1 mutants. The dgat1 mutant displayed a major (76%) reduction in [ 14C]TAG accumulation whereas pdat1 TAG labelling was only slightly reduced. Thus, DGAT1 has a principal role in TAG biosynthesis in young leaves. During a 4h chase period, radioactivity in TAG declined 70%, whereas the turnover of [ 14C]acyl chains of phosphatidylcholine (PC) and other polar lipids was much lower. Sixty percent of [ 14C]12:0 was directly incorporated into glycerolipids without modification, whereas 40% was elongated and desaturated to 16:0 and 18:1 by plastids. The unmodified [ 14C]12:0 and the plastid products of [ 14C]12:0 metabolism entered different pathways. Although plastid-modified 14C-labelled products accumulated in monogalactosyldiacylglycerol, PC, phosphatidylethanolamine, and diacylglcerol (DAG), there was almost no accumulation of [ 14C]16:0 and [ 14C]18:1 in TAG. Lastly, because DAG and acyl-CoA are direct precursors of TAG, the differential labelling of polar glycerolipids and TAG by [ 14C]12:0 and its plastid-modified products provides evidence for multiple subcellular pools of both acyl-CoA and DAG.« less

Assessing sub-Saharan Erythrina for efficacy: traditional uses, biological activities and phytochemistry.

PubMed

Kone, Witabouna Mamidou; Solange, Kakou-Ngazoa E; Dosso, Mireille

2011-05-15

The genus Erythrina comprises more than 100 species, widely distributed in tropical and subtropical areas. In Africa, 31 wild species and 14 cultivated species have been described. In sub-Saharan Africa, Erythrina species are used to treat frequent parasitic and microbial diseases, inflammation, cancer, wounds. The rationale of these traditional uses in African traditional medicine was established by screening several species for biological activities. Promising activities were found against bacteria, parasites (Plasmodium), human and phytopathogenic fungi, some of which were multidrug resistant (MDR) micro organisms. Some species also exhibited antioxidant, anti-inflammatory activities and enzymes inhibitory properties. Most of the species chemically investigated were reported to contain flavanones, prenylated isoflavones, isoflavanones and pterocarpans. Some phytochemicals (vogelin B, vogelin C, isowightcone, abyssinin II, derrone) were the active principles as antibacterials, antifungals, antiplasmodials and inhibitors of enzyme borne diseases (PTP1B, HIV protease, DGAT). This review highlights the important role of Erythrina species as sources of lead compounds or new class of phytotherapeutic agents for fighting against major public health (MDR infections, cancer, diabetes, obesity) in sub-Saharan Africa.

Genes Whose Gain or Loss-Of-Function Increases Skeletal Muscle Mass in Mice: A Systematic Literature Review.

PubMed

Verbrugge, Sander A J; Schönfelder, Martin; Becker, Lore; Yaghoob Nezhad, Fakhreddin; Hrabě de Angelis, Martin; Wackerhage, Henning

2018-01-01

Skeletal muscle mass differs greatly in mice and humans and this is partially inherited. To identify muscle hypertrophy candidate genes we conducted a systematic review to identify genes whose experimental loss or gain-of-function results in significant skeletal muscle hypertrophy in mice. We found 47 genes that meet our search criteria and cause muscle hypertrophy after gene manipulation. They are from high to small effect size: Ski, Fst, Acvr2b, Akt1, Mstn, Klf10, Rheb, Igf1, Pappa, Ppard, Ikbkb, Fstl3, Atgr1a, Ucn3, Mcu, Junb, Ncor1, Gprasp1, Grb10, Mmp9, Dgkz, Ppargc1a (specifically the Ppargc1a4 isoform), Smad4, Ltbp4, Bmpr1a, Crtc2, Xiap, Dgat1, Thra, Adrb2, Asb15, Cast, Eif2b5, Bdkrb2, Tpt1, Nr3c1, Nr4a1, Gnas, Pld1, Crym, Camkk1, Yap1, Inhba, Tp53inp2, Inhbb, Nol3, Esr1 . Knock out, knock down, overexpression or a higher activity of these genes causes overall muscle hypertrophy as measured by an increased muscle weight or cross sectional area. The mean effect sizes range from 5 to 345% depending on the manipulated gene as well as the muscle size variable and muscle investigated. Bioinformatical analyses reveal that Asb15, Klf10, Tpt1 are most highly expressed hypertrophy genes in human skeletal muscle when compared to other tissues. Many of the muscle hypertrophy-regulating genes are involved in transcription and ubiquitination. Especially genes belonging to three signaling pathways are able to induce hypertrophy: (a) Igf1-Akt-mTOR pathway, (b) myostatin-Smad signaling, and (c) the angiotensin-bradykinin signaling pathway. The expression of several muscle hypertrophy-inducing genes and the phosphorylation of their protein products changes after human resistance and high intensity exercise, in maximally stimulated mouse muscle or in overloaded mouse plantaris.

Genome Wide Analysis of Fertility and Production Traits in Italian Holstein Cattle

PubMed Central

Stella, Alessandra; Biffani, Stefano; Negrini, Riccardo; Lazzari, Barbara; Ajmone-Marsan, Paolo; Williams, John L .

2013-01-01

A genome wide scan was performed on a total of 2093 Italian Holstein proven bulls genotyped with 50K single nucleotide polymorphisms (SNPs), with the objective of identifying loci associated with fertility related traits and to test their effects on milk production traits. The analysis was carried out using estimated breeding values for the aggregate fertility index and for each trait contributing to the index: angularity, calving interval, non-return rate at 56 days, days to first service, and 305 day first parity lactation. In addition, two production traits not included in the aggregate fertility index were analysed: fat yield and protein yield. Analyses were carried out using all SNPs treated separately, further the most significant marker on BTA14 associated to milk quality located in the DGAT1 region was treated as fixed effect. Genome wide association analysis identified 61 significant SNPs and 75 significant marker-trait associations. Eight additional SNP associations were detected when SNP located near DGAT1 was included as a fixed effect. As there were no obvious common SNPs between the traits analyzed independently in this study, a network analysis was carried out to identify unforeseen relationships that may link production and fertility traits. PMID:24265800

Target of rapamycin (TOR) plays a critical role in triacylglycerol accumulation in microalgae.

PubMed

Imamura, Sousuke; Kawase, Yasuko; Kobayashi, Ikki; Sone, Toshiyuki; Era, Atsuko; Miyagishima, Shin-Ya; Shimojima, Mie; Ohta, Hiroyuki; Tanaka, Kan

2015-10-01

Most microalgae produce triacylglycerol (TAG) under stress conditions such as nitrogen depletion, but the underlying molecular mechanism remains unclear. In this study, we focused on the role of target of rapamycin (TOR) in TAG accumulation. TOR is a serine/threonine protein kinase that is highly conserved and plays pivotal roles in nitrogen and other signaling pathways in eukaryotes. We previously constructed a rapamycin-susceptible Cyanidioschyzon merolae, a unicellular red alga, by expressing yeast FKBP12 protein to evaluate the results of TOR inhibition (Imamura et al. in Biochem Biophys Res Commun 439:264-269, 2013). By using this strain, we here report that rapamycin-induced TOR inhibition results in accumulation of cytoplasmic lipid droplets containing TAG. Transcripts for TAG synthesis-related genes, such as glycerol-3-phosphate acyltransferase and acyl-CoA:diacylglycerol acyltransferase (DGAT), were increased by rapamycin treatment. We also found that fatty acid synthase-dependent de novo fatty acid synthesis was required for the accumulation of lipid droplets. Induction of TAG and up-regulation of DGAT gene expression by rapamycin were similarly observed in the unicellular green alga, Chlamydomonas reinhardtii. These results suggest the general involvement of TOR signaling in TAG accumulation in divergent microalgae.

Lipid accumulation and biosynthesis genes response of the oleaginous Chlorella pyrenoidosa under three nutrition stressors

PubMed Central

2014-01-01

Background Microalgae can accumulate considerable amounts of lipids under different nutrient-deficient conditions, making them as one of the most promising sustainable sources for biofuel production. These inducible processes provide a powerful experimental basis for fully understanding the mechanisms of physiological acclimation, lipid hyperaccumulation and gene expression in algae. In this study, three nutrient-deficiency strategies, viz nitrogen-, phosphorus- and iron-deficiency were applied to trigger the lipid hyperaccumulation in an oleaginous Chlorella pyrenoidosa. Regular patterns of growth characteristics, lipid accumulation, physiological parameters, as well as the expression patterns of lipid biosynthesis-related genes were fully analyzed and compared. Results Our results showed that all the nutrient stress conditions could enhance the lipid content considerably compared with the control. The total lipid and neutral lipid contents exhibit the most marked increment under nitrogen deficiency, achieving 50.32% and 34.29% of dry cell weight at the end of cultivation, respectively. Both photosynthesis indicators and reactive oxygen species parameters reveal that physiological stress turned up when exposed to nutrient depletions. Time-course transcript patterns of lipid biosynthesis-related genes showed that diverse expression dynamics probably contributes to the different lipidic phenotypes under stress conditions. By analyzing the correlation between lipid content and gene expression level, we pinpoint several genes viz. rbsL, me g6562, accA, accD, dgat g2354, dgat g3280 and dgat g7063, which encode corresponding enzymes or subunits of malic enzyme, ACCase and diacylglycerol acyltransferase in the de novo TAG biosynthesis pathway, are highly related to lipid accumulation and might be exploited as target genes for genetic modification. Conclusion This study provided us not only a comprehensive picture of adaptive mechanisms from physiological perspective, but also a number of targeted genes that can be used for a systematic metabolic engineering. Besides, our results also represented the feasibility of lipid production through trophic transition cultivation modes, throwing light on a two-stage microalgal lipid production strategy with which heterotrophy stage provides sufficient robust seed and nitrogen-starvation photoautotrophy stage enhances the overall lipid productivity. PMID:24479413

Examination of Triacylglycerol Biosynthetic Pathways via De Novo Transcriptomic and Proteomic Analyses in an Unsequenced Microalga

DTIC Science & Technology

2011-10-17

analysis results. The components of the TAG biosynthetic pathway, including glycerol-3-phosphate acyl- transferase (GPAT), lyso- phosphatidic acid ...acyltransferase (LPAAT), phosphatidic acid phosphatase (PAP), lyso-phosphati- dylcholine acyltransferase (LPAT), and diacylglycerol acyltransfer- ase (DGAT...transfer to position one of G3P results in the formation of lyso- phosphatidic acid (LPA), in a reaction catalyzed by GPAT. Subsequent acyl transfer to

Metabolic engineering of Pichia pastoris to produce ricinoleic acid, a hydroxy fatty acid of industrial importance.

PubMed

Meesapyodsuk, Dauenpen; Chen, Yan; Ng, Siew Hon; Chen, Jianan; Qiu, Xiao

2015-11-01

Ricinoleic acid (12-hydroxyoctadec-cis-9-enoic acid) has many specialized uses in bioproduct industries, while castor bean is currently the only commercial source for the fatty acid. This report describes metabolic engineering of a microbial system (Pichia pastoris) to produce ricinoleic acid using a "push" (synthesis) and "pull" (assembly) strategy. CpFAH, a fatty acid hydroxylase from Claviceps purpurea, was used for synthesis of ricinoleic acid, and CpDGAT1, a diacylglycerol acyl transferase for the triacylglycerol synthesis from the same species, was used for assembly of the fatty acid. Coexpression of CpFAH and CpDGAT1 produced higher lipid contents and ricinoleic acid levels than expression of CpFAH alone. Coexpression in a mutant haploid strain defective in the Δ12 desaturase activity resulted in a higher level of ricinoleic acid than that in the diploid strain. Intriguingly, the ricinoleic acid produced was mainly distributed in the neutral lipid fractions, particularly the free fatty acid form, but with little in the polar lipids. This work demonstrates the effectiveness of the metabolic engineering strategy and excellent capacity of the microbial system for production of ricinoleic acid as an alternative to plant sources for industrial uses. Copyright © 2015 by the American Society for Biochemistry and Molecular Biology, Inc.

Metabolic engineering of Pichia pastoris to produce ricinoleic acid, a hydroxy fatty acid of industrial importance[S

PubMed Central

Meesapyodsuk, Dauenpen; Chen, Yan; Ng, Siew Hon; Chen, Jianan; Qiu, Xiao

2015-01-01

Ricinoleic acid (12-hydroxyoctadec-cis-9-enoic acid) has many specialized uses in bioproduct industries, while castor bean is currently the only commercial source for the fatty acid. This report describes metabolic engineering of a microbial system (Pichia pastoris) to produce ricinoleic acid using a “push” (synthesis) and “pull” (assembly) strategy. CpFAH, a fatty acid hydroxylase from Claviceps purpurea, was used for synthesis of ricinoleic acid, and CpDGAT1, a diacylglycerol acyl transferase for the triacylglycerol synthesis from the same species, was used for assembly of the fatty acid. Coexpression of CpFAH and CpDGAT1 produced higher lipid contents and ricinoleic acid levels than expression of CpFAH alone. Coexpression in a mutant haploid strain defective in the Δ12 desaturase activity resulted in a higher level of ricinoleic acid than that in the diploid strain. Intriguingly, the ricinoleic acid produced was mainly distributed in the neutral lipid fractions, particularly the free fatty acid form, but with little in the polar lipids. This work demonstrates the effectiveness of the metabolic engineering strategy and excellent capacity of the microbial system for production of ricinoleic acid as an alternative to plant sources for industrial uses. PMID:26323290

Effects of Male Hypogonadism on Regional Adipose Tissue Fatty Acid Storage and Lipogenic Proteins

PubMed Central

Santosa, Sylvia; Jensen, Michael D.

2012-01-01

Testosterone has long been known to affect body fat distribution, although the underlying mechanisms remain elusive. We investigated the effects of chronic hypogonadism in men on adipose tissue fatty acid (FA) storage and FA storage factors. Twelve men with chronic hypogonadism and 13 control men matched for age and body composition: 1) underwent measures of body composition with dual energy x-ray absorptiometry and an abdominal CT scan; 2) consumed an experimental meal containing [3H]triolein to determine the fate of meal FA (biopsy-measured adipose storage vs. oxidation); 3) received infusions of [U-13C]palmitate and [1-14C]palmitate to measure rates of direct free (F)FA storage (adipose biopsies). Adipose tissue lipoprotein lipase, acyl-CoA synthetase (ACS), and diacylglycerol acetyl-transferase (DGAT) activities, as well as, CD36 content were measured to understand the mechanism by which alterations in fat storage occur in response to testosterone deficiency. Results of the study showed that hypogonadal men stored a greater proportion of both dietary FA and FFA in lower body subcutaneous fat than did eugonadal men (both p<0.05). Femoral adipose tissue ACS activity was significantly greater in hypogonadal than eugonadal men, whereas CD36 and DGAT were not different between the two groups. The relationships between these proteins and FA storage varied somewhat between the two groups. We conclude that chronic effects of testosterone deficiency has effects on leg adipose tissue ACS activity which may relate to greater lower body FA storage. These results provide further insight into the role of androgens in body fat distribution and adipose tissue metabolism in humans. PMID:22363653

Short communication: Validation of 4 candidate causative trait variants in 2 cattle breeds using targeted sequence imputation.

PubMed

Pausch, Hubert; Wurmser, Christine; Reinhardt, Friedrich; Emmerling, Reiner; Fries, Ruedi

2015-06-01

Most association studies for pinpointing trait-associated variants are performed within breed. The availability of sequence data from key ancestors of several cattle breeds now enables immediate assessment of the frequency of trait-associated variants in populations different from the mapping population and their imputation into large validation populations. The objective of this study was to validate the effects of 4 putatively causative variants on milk production traits, male fertility, and stature in German Fleckvieh and Holstein-Friesian animals using targeted sequence imputation. We used whole-genome sequence data of 456 animals to impute 4 missense mutations in DGAT1, GHR, PRLR, and PROP1 into 10,363 Fleckvieh and 8,812 Holstein animals. The accuracy of the imputed genotypes exceeded 95% for all variants. Association testing with imputed variants revealed consistent antagonistic effects of the DGAT1 p.A232K and GHR p.F279Y variants on milk yield and protein and fat contents, respectively, in both breeds. The allele frequency of both polymorphisms has changed considerably in the past 20 yr, indicating that they were targets of recent selection for milk production traits. The PRLR p.S18N variant was associated with yield traits in Fleckvieh but not in Holstein, suggesting that it may be in linkage disequilibrium with a mutation affecting yield traits rather than being causal. The reported effects of the PROP1 p.H173R variant on milk production, male fertility, and stature could not be confirmed. Our results demonstrate that population-wide imputation of candidate causal variants from sequence data is feasible, enabling their rapid validation in large independent populations. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Heterologous expression of two GPATs from Jatropha curcas alters seed oil levels in transgenic Arabidopsis thaliana.

PubMed

Misra, Aparna; Khan, Kasim; Niranjan, Abhishek; Kumar, Vinod; Sane, Vidhu A

2017-10-01

Oils and fats are stored in endosperm during seed development in the form of triacylglycerols. Three acyltransferases: glycerol-3-phosphate acyltransferase (GPAT), lysophosphatidyl acyltransferase (LPAT) and diacylglycerol acyltransferase (DGAT) are involved in the storage lipid biosynthesis and catalyze the stepwise acylation of glycerol backbone. In this study two members of GPAT gene family (JcGPAT1 and JcGPAT2) from Jatropha seeds were identified and characterized. Sequence analysis suggested that JcGPAT1 and JcGPAT2 are homologous to Arabidopsis acyltransferase-1 (ATS1) and AtGPAT9 respectively. The sub-cellular localization studies of these two GPATs showed that JcGPAT1 localizes into plastid whereas JcGPAT2 localizes in to endoplasmic reticulum. JcGPAT1 and JcGPAT2 expressed throughout the seed development with higher expression in fully matured seed compared to immature seed. The transcript levels of JcGPAT2 were higher in comparison to JcGPAT1 in different developmental stages of seed. Over-expression of JcGPAT1 and JcGPAT2 under constitutive and seed specific promoters in Arabidopsis thaliana increased total oil content. Transgenic seeds of JcGPAT2-OE lines accumulated 43-60% more oil than control seeds whereas seeds of Arabidopsis lines over-expressing plastidial GPAT lead to only 13-20% increase in oil content. Functional characterization of GPAT homologues of Jatropha in Arabidopsis suggested that these are involved in oil biosynthesis but might have specific roles in Jatropha. Copyright © 2017 Elsevier B.V. All rights reserved.

Host cells and methods for producing isoprenyl alkanoates

DOEpatents

Lee, Taek Soon; Fortman, Jeffrey L.; Keasling, Jay D.

2015-12-01

The invention provides for a method of producing an isoprenyl alkanoate in a genetically modified host cell. In one embodiment, the method comprises culturing a genetically modified host cell which expresses an enzyme capable of catalyzing the esterification of an isoprenol and a straight-chain fatty acid, such as an alcohol acetyltransferase (AAT), wax ester synthase/diacylglycerol acyltransferase (WS/DGAT) or lipase, under a suitable condition so that the isoprenyl alkanoate is produced.

Is hepatic lipid metabolism of beef cattle influenced by breed and dietary silage level?

PubMed Central

2014-01-01

Background In ruminants, unsaturated dietary fatty acids are biohydrogenated in the rumen and are further metabolised in various tissues, including liver, which has an important role in lipid and lipoprotein metabolism. Therefore, manipulation of muscle fatty acid composition should take into account liver metabolism. In the present study, the influence of breed and diet on liver lipid composition and gene expression was investigated in order to clarify the role of this organ in the lipid metabolism of ruminants. Forty purebred young bulls from two phylogenetically distant autochthonous cattle breeds, Alentejana and Barrosã, were assigned to two different diets (low vs. high silage) and slaughtered at 18 months of age. Liver fatty acid composition, mRNA levels of enzymes and transcription factors involved in lipid metabolism, as well as the plasma lipid profile, were assessed. Results In spite of similar plasma non-esterified fatty acids levels, liver triacylglycerols content was higher in Barrosã than in Alentejana bulls. Moreover, the fatty acid composition of liver was clearly distinct from the remaining tissues involved in fatty acid metabolism of ruminants, as shown by Principal Components Analysis. The hepatic tissue is particularly rich in α-linolenic acid and their products of desaturation and elongation. Results indicate that DGAT1, ELOVL2, FADS1 and FADS2 genes influence the fatty acid composition of the liver the most. Moreover, genes such as DGAT1 and ELOVL2 appear to be more sensitive to genetic background than to dietary manipulation, whereas genes encoding for desaturases, such as FADS1, appear to be modulated by dietary silage level. Conclusions Our results indicate that liver plays an important role in the biosynthesis of n-3 LC-PUFA. It is also suggested that dietary silage level influences the hepatic fatty acid metabolism in a breed-dependent manner, through changes in the expression of genes encoding for enzymes associated with the desaturation and elongation pathway. The importance of devising custom-made feeding strategies taking into account the genetic background is, therefore, stressed by the results from this experiment. PMID:24621212

Functional roles of three cutin biosynthetic acyltransferases in cytokinin responses and skotomorphogenesis.

PubMed

Wu, Lei; Zhou, Zhao-Yang; Zhang, Chun-Guang; Chai, Juan; Zhou, Qin; Wang, Li; Hirnerová, Eva; Mrvková, Michaela; Novák, Ondřej; Guo, Guang-Qin

2015-01-01

Cytokinins (CKs) regulate plant development and growth via a two-component signaling pathway. By forward genetic screening, we isolated an Arabidopsis mutant named grow fast on cytokinins 1 (gfc1), whose seedlings grew larger aerial parts on MS medium with CK. gfc1 is allelic to a previously reported cutin mutant defective in cuticular ridges (dcr). GFC1/DCR encodes a soluble BAHD acyltransferase (a name based on the first four enzymes characterized in this family: Benzylalcohol O-acetyltransferase, Anthocyanin O-hydroxycinnamoyltransferase, anthranilate N-hydroxycinnamoyl/benzoyltransferase and Deacetylvindoline 4-O-acetyltransferase) with diacylglycerol acyltransferase (DGAT) activity in vitro and is necessary for normal cuticle formation on epidermis in vivo. Here we show that gfc1 was a CK-insensitive mutant, as revealed by its low regeneration frequency in vitro and resistance to CK in adventitious root formation and dark-grown hypocotyl inhibition assays. In addition, gfc1 had de-etiolated phenotypes in darkness and was therefore defective in skotomorphogenesis. The background expression levels of most type-A Arabidopsis Response Regulator (ARR) genes were higher in the gfc1 mutant. The gfc1-associated phenotypes were also observed in the cutin-deficient glycerol-3-phosphate acyltransferase 4/8 (gpat4/8) double mutant [defective in glycerol-3-phosphate (G3P) acyltransferase enzymes GPAT4 and GPAT8, which redundantly catalyze the acylation of G3P by hydroxyl fatty acid (OH-FA)], but not in the cutin-deficient mutant cytochrome p450, family 86, subfamily A, polypeptide 2/aberrant induction of type three 1 (cyp86A2/att1), which affects the biosynthesis of some OH-FAs. Our results indicate that some acyltransferases associated with cutin formation are involved in CK responses and skotomorphogenesis in Arabidopsis.

Functional Roles of Three Cutin Biosynthetic Acyltransferases in Cytokinin Responses and Skotomorphogenesis

PubMed Central

Chai, Juan; Zhou, Qin; Wang, Li; Hirnerová, Eva; Mrvková, Michaela; Novák, Ondřej; Guo, Guang-Qin

2015-01-01

Cytokinins (CKs) regulate plant development and growth via a two-component signaling pathway. By forward genetic screening, we isolated an Arabidopsis mutant named grow fast on cytokinins 1 (gfc1), whose seedlings grew larger aerial parts on MS medium with CK. gfc1 is allelic to a previously reported cutin mutant defective in cuticular ridges (dcr). GFC1/DCR encodes a soluble BAHD acyltransferase (a name based on the first four enzymes characterized in this family: Benzylalcohol O-acetyltransferase, Anthocyanin O-hydroxycinnamoyltransferase, anthranilate N-hydroxycinnamoyl/benzoyltransferase and Deacetylvindoline 4-O-acetyltransferase) with diacylglycerol acyltransferase (DGAT) activity in vitro and is necessary for normal cuticle formation on epidermis in vivo. Here we show that gfc1 was a CK-insensitive mutant, as revealed by its low regeneration frequency in vitro and resistance to CK in adventitious root formation and dark-grown hypocotyl inhibition assays. In addition, gfc1 had de-etiolated phenotypes in darkness and was therefore defective in skotomorphogenesis. The background expression levels of most type-A Arabidopsis Response Regulator (ARR) genes were higher in the gfc1 mutant. The gfc1-associated phenotypes were also observed in the cutin-deficient glycerol-3-phosphate acyltransferase 4/8 (gpat4/8) double mutant [defective in glycerol-3-phosphate (G3P) acyltransferase enzymes GPAT4 and GPAT8, which redundantly catalyze the acylation of G3P by hydroxyl fatty acid (OH-FA)], but not in the cutin-deficient mutant cytochrome p450, family 86, subfamily A, polypeptide 2/aberrant induction of type three 1 (cyp86A2/att1), which affects the biosynthesis of some OH-FAs. Our results indicate that some acyltransferases associated with cutin formation are involved in CK responses and skotomorphogenesis in Arabidopsis. PMID:25803274

SGLT2 Protein Expression Is Increased in Human Diabetic Nephropathy

PubMed Central

Wang, Xiaoxin X.; Levi, Jonathan; Luo, Yuhuan; Myakala, Komuraiah; Herman-Edelstein, Michal; Qiu, Liru; Wang, Dong; Peng, Yingqiong; Grenz, Almut; Lucia, Scott; Dobrinskikh, Evgenia; D'Agati, Vivette D.; Koepsell, Hermann; Kopp, Jeffrey B.; Rosenberg, Avi Z.; Levi, Moshe

2017-01-01

There is very limited human renal sodium gradient-dependent glucose transporter protein (SGLT2) mRNA and protein expression data reported in the literature. The first aim of this study was to determine SGLT2 mRNA and protein levels in human and animal models of diabetic nephropathy. We have found that the expression of SGLT2 mRNA and protein is increased in renal biopsies from human subjects with diabetic nephropathy. This is in contrast to db-db mice that had no changes in renal SGLT2 protein expression. Furthermore, the effect of SGLT2 inhibition on renal lipid content and inflammation is not known. The second aim of this study was to determine the potential mechanisms of beneficial effects of SGLT2 inhibition in the progression of diabetic renal disease. We treated db/db mice with a selective SGLT2 inhibitor JNJ 39933673. We found that SGLT2 inhibition caused marked decreases in systolic blood pressure, kidney weight/body weight ratio, urinary albumin, and urinary thiobarbituric acid-reacting substances. SGLT2 inhibition prevented renal lipid accumulation via inhibition of carbohydrate-responsive element-binding protein-β, pyruvate kinase L, SCD-1, and DGAT1, key transcriptional factors and enzymes that mediate fatty acid and triglyceride synthesis. SGLT2 inhibition also prevented inflammation via inhibition of CD68 macrophage accumulation and expression of p65, TLR4, MCP-1, and osteopontin. These effects were associated with reduced mesangial expansion, accumulation of the extracellular matrix proteins fibronectin and type IV collagen, and loss of podocyte markers WT1 and synaptopodin, as determined by immunofluorescence microscopy. In summary, our study showed that SGLT2 inhibition modulates renal lipid metabolism and inflammation and prevents the development of nephropathy in db/db mice. PMID:28196866

Ceramide Is Metabolized to Acylceramide and Stored in Lipid Droplets.

PubMed

Senkal, Can E; Salama, Mohamed F; Snider, Ashley J; Allopenna, Janet J; Rana, Nadia A; Koller, Antonius; Hannun, Yusuf A; Obeid, Lina M

2017-03-07

In an approach aimed at defining interacting partners of ceramide synthases (CerSs), we found that fatty acyl-CoA synthase ACSL5 interacts with all CerSs. We demonstrate that ACSL5-generated FA-CoA was utilized with de novo ceramide for the generation of acylceramides, poorly studied ceramide metabolites. Functionally, inhibition of ceramide channeling to acylceramide enhanced accumulation of de novo ceramide and resulted in augmentation of ceramide-mediated apoptosis. Mechanistically, we show that acylceramide generation is catalyzed by diacylglycerol acyltransferase 2 (DGAT2) on lipid droplets. In summary, this study identifies a metabolic pathway of acylceramide generation and its sequestration in LDs in cells and in livers of mice on a high-fat diet. The study also implicates this pathway in ceramide-mediated apoptosis, and has implications in co-regulation of triglyceride and sphingolipid metabolisms. Published by Elsevier Inc.

A Genetic Screen for Mutants with Supersized Lipid Droplets in Caenorhabditis elegans

PubMed Central

Li, Shiwei; Xu, Shibin; Ma, Yanli; Wu, Shuang; Feng, Yu; Cui, Qingpo; Chen, Lifeng; Zhou, Shuang; Kong, Yuanyuan; Zhang, Xiaoyu; Yu, Jialei; Wu, Mengdi; Zhang, Shaobing O.

2016-01-01

To identify genes that regulate the dynamics of lipid droplet (LD) size, we have used the genetically tractable model organism Caenorhabditis elegans, whose wild-type LD population displays a steady state of size with an upper limit of 3 μm in diameter. From a saturated forward genetic screen of 6.7 × 105 mutagenized haploid genomes, we isolated 118 mutants with supersized intestinal LDs often reaching 10 μm. These mutants define nine novel complementation groups, in addition to four known genes (maoc-1, dhs-28, daf-22, and prx-10). The nine groups are named drop (lipid droplet abnormal) and categorized into four classes. Class I mutants drop-5 and drop-9, similar to prx-10, are up-regulated in ACS-22-DGAT-2-dependent LD growth, resistant to LD hydrolysis, and defective in peroxisome import. Class II mutants drop-2, drop-3, drop-6, and drop-7 are up-regulated in LD growth, are resistant to LD hydrolysis, but are not defective in peroxisome import. Class III mutants drop-1 and drop-8 are neither up-regulated in LD growth nor resistant to LD hydrolysis, but seemingly up-regulated in LD fusion. Class IV mutant drop-4 is cloned as sams-1 and, different to the other three classes, is ACS-22-independent and hydrolysis-resistant. These four classes of supersized LD mutants should be valuable for mechanistic studies of LD cellular processes including growth, hydrolysis, and fusion. PMID:27261001

Genetic variability of milk fatty acids.

PubMed

Arnould, V M-R; Soyeurt, H

2009-01-01

The milk fatty acid (FA) profile is far from the optimal fat composition in regards to human health. The natural sources of variation, such as feeding or genetics, could be used to increase the concentrations of unsaturated fatty acids. The impact of feeding is well described. However, genetic effects on the milk FA composition begin to be extensively studied. This paper summarizes the available information about the genetic variability of FAs. The greatest breed differences in FA composition are observed between Holstein and Jersey milk. Milk fat of the latter breed contains higher concentrations of saturated FAs, especially short-chain FAs. The variation of the delta-9 desaturase activity estimated from specific FA ratios could explain partly these breed differences. The choice of a specific breed seems to be a possibility to improve the nutritional quality of milk fat. Generally, the proportions of FAs in milk are more heritable than the proportions of these same FAs in fat. Heritability estimates range from 0.00 to 0.54. The presence of some single nucleotide polymorphisms could explain partly the observed individual genetic variability. The polymorphisms detected on SCD1 and DGAT1 genes influence the milk FA composition. The SCD1 V allele increases the unsaturation of C16 and C18. The DGAT1 A allele is related to the unsaturation of C18. So, a combination of the molecular and quantitative approaches should be used to develop tools helping farmers in the selection of their animals to improve the nutritional quality of the produced milk fat.

Developmental bisphenol A (BPA) exposure leads to sex-specific modification of hepatic gene expression and epigenome at birth that may exacerbate high-fat diet-induced hepatic steatosis.

PubMed

Strakovsky, Rita S; Wang, Huan; Engeseth, Nicki J; Flaws, Jodi A; Helferich, William G; Pan, Yuan-Xiang; Lezmi, Stéphane

2015-04-15

Developmental bisphenol A (BPA) exposure increases adulthood hepatic steatosis with reduced mitochondrial function. To investigate the potential epigenetic mechanisms behind developmental BPA-induced hepatic steatosis, pregnant Sprague-Dawley rats were dosed with vehicle (oil) or BPA (100μg/kg/day) from gestational day 6 until postnatal day (PND) 21. After weaning, offspring were either challenged with a high-fat (HF; 45% fat) or remained on a control (C) diet until PND110. From PND60 to 90, both BPA and HF diet increased the fat/lean ratio in males only, and the combination of BPA and HF diet appeared to cause the highest ratio. On PND110, Oil-HF, BPA-C, and BPA-HF males had higher hepatic lipid accumulation than Oil-C, with microvesicular steatosis being marked in the BPA-HF group. Furthermore, on PND1, BPA increased and modified hepatic triglyceride (TG) and free fatty acid (FFA) compositions in males only. In PND1 males, BPA increased hepatic expression of FFA uptake gene Fat/Cd36, and decreased the expression of TG synthesis- and β-oxidation-related genes (Dgat, Agpat6, Cebpα, Cebpβ, Pck1, Acox1, Cpt1a, Cybb). BPA altered DNA methylation and histone marks (H3Ac, H4Ac, H3Me2K4, H3Me3K36), and decreased the binding of several transcription factors (Pol II, C/EBPβ, SREBP1) within the male Cpt1a gene, the key β-oxidation enzyme. In PND1 females, BPA only increased the expression of genes involved in FFA uptake and TG synthesis (Lpl, Fasn, and Dgat). These data suggest that developmental BPA exposure alters and reprograms hepatic β-oxidation capacity in males, potentially through the epigenetic regulation of genes, and further alters the response to a HF diet. Copyright © 2015 Elsevier Inc. All rights reserved.

Impaired adipose tissue lipid storage, but not altered lipolysis, contributes to elevated levels of NEFA in type 2 diabetes. Degree of hyperglycemia and adiposity are important factors.

PubMed

Pereira, Maria J; Skrtic, Stanko; Katsogiannos, Petros; Abrahamsson, Niclas; Sidibeh, Cherno O; Dahgam, Santosh; Månsson, Marianne; Risérus, Ulf; Kullberg, Joel; Eriksson, Jan W

2016-12-01

Elevated levels of circulating non-esterified fatty acids (NEFA) mediate many adverse metabolic effects. In this work we aim to determine the impact of type 2 diabetes (T2D), glycemic control and obesity on lipolysis regulation. 20 control and 20 metformin-treated T2D subjects were matched for sex (10M/10 F), age (58±11 vs 58±9 y) and BMI (30.8±4.6 vs 30.7±4.9kg/m 2 ). In vivo lipolysis was assessed during a 3h-OGTT with plasma glycerol and NEFA levels. Subcutaneous adipose tissue (SAT) biopsies were obtained to measure mRNA and metabolite levels of factors related to lipolysis and lipid storage and to assess in vitro lipolysis in isolated subcutaneous adipocytes. Plasma NEFA AUC during the OGTT where higher 30% (P=0.005) in T2D than in control subjects, but plasma glycerol AUC and subcutaneous adipocyte lipolysis in vitro were similar, suggesting that adipose tissue lipolysis is not altered. Expression in SAT of genes involved in lipid storage (FABP4, DGAT1, FASN) were reduced in T2D subjects compared with controls, but no differences were seen for genes involved in lipolysis. T2D subjects had elevated markers of beta-oxidation, α-hydroxybutyrate (1.4-fold, P<0.01) and β-hydroxybutyrate (1.7-fold, P<0.05) in plasma. In multivariate analysis, HbA1c, visceral adipose tissue volume and sex (male) were significantly associated with NEFA AUC in T2D subjects. In T2D subjects, NEFA turnover is impaired, but not due to defects in lipolysis or lipid beta-oxidation. Impaired adipose NEFA re-esterification or de novo lipogenesis is likely to contribute to higher NEFA plasma levels in T2D. The data suggest that hyperglycemia and adiposity are important contributing factors for the regulation of plasma NEFA concentrations. Copyright © 2016 Elsevier Inc. All rights reserved.

Polymorphisms in genes in the SREBP1 signalling pathway and SCD are associated with milk fatty acid composition in Holstein cattle.

PubMed

Rincon, Gonzalo; Islas-Trejo, Alma; Castillo, Alejandro R; Bauman, Dale E; German, Bruce J; Medrano, Juan F

2012-02-01

Genes in the sterol regulatory element-binding protein-1 (SREBP1) pathway play a central role in regulation of milk fat synthesis, especially the de-novo synthesis of saturated fatty acids. SCD, a SREBP-responsive gene, is the key enzyme in the synthesis of monounsaturated fatty acids in the mammary gland. In the present study, we discovered SNP in candidate genes associated with this signalling pathway and SCD to identify genetic markers that can be used for genetic and metabolically directed selection in cattle. We resequenced six candidate genes in the SREBP1 pathway (SREBP1, SCAP, INSIG1, INSIG2, MBTPS1, MBTPS2) and two genes for SCD (SCD1 and SCD5) and discovered 47 Tag SNP that were used in a marker-trait association study. Milk and blood samples were collected from Holstein cows in their 1st or 2nd parity at 100-150 days of lactation. Individual fatty acids from C4 to C20, saturated fatty acid (SFA) content, monounsaturated fatty acid content, polyunsaturated fatty acid content and desaturase indexes were measured and used to perform the asociation analysis. Polymorphisms in the SCD5 and INSIG2 genes were the most representative markers associated with SFA/unsaturated fatty acid (UFA) ratio in milk. The analysis of desaturation activity determined that markers in the SCD1 and SCD5 genes showed the most significant effects. DGAT1 K232A marker was included in the study to examine the effect of this marker on the variation of milk fatty acids in our Holstein population. The percentage of variance explained by DGAT1 in the analysis was only 6% of SFA/UFA ratio. Milk fat depression was observed in one of the dairy herds and in this particular dairy one SNP in the SREBP1 gene (rs41912290) accounted for 40% of the phenotypic variance. Our results provide detailed SNP information for key genes in the SREBP1 signalling pathway and SCD that can be used to change milk fat composition by marker-assisted breeding to meet consumer demands regarding human health, as well as furthering understanding of technological aspects of cows' milk.

Usefulness of hepatitis C virus RNA counts by second generation HCV bDNA-probe in chronic hepatitis C based on the HCV genotype.

PubMed

Kobayashi, M; Kumada, H; Arase, Y; Chayama, K; Kobayashi, M; Tsubota, A; Koida, I; Saitoh, S; Suzuki, Y; Murashima, N; Ikeda, K; Miyano, Y; Mizoshita, K; Matsuda, M; Koike, H; Hashimoto, M

1998-04-01

Detection of hepatitis C virus (HCV) RNA by a second generation (ver 2) HCV bDNA-probe method (bDNA-probe) was compared with detection by the first generation (ver 1) assay. The two assays were performed simultaneously with the same serum samples of HCV genotypes 1b, 2a, 2b, 3a, and 3b. The positive rates with ver 1 were 82% for HCV genotype 1b (type 1b), 57.6% for HCV genotype 2a (type 2a), 75.0% for HCV genotype 2b (type 2b), 55.6% for HCV genotype 3a (type 3a), and 93.8% for HCV genotype 3b (type 3b). The positive rates with ver 2 were 95.0% for type 1b, 93.9% for type 2a, 83.3% for type 2b, 100% for type 3a, and 93.8% for type 3b. With Fisher's exact test, the detection rate for type 2a was significantly higher (P = 0.001) with ver 2 than with ver 1. We obtained regression lines using the HCV counts measured by bDNA-probe on the y axis and the HCV counts obtained by an HCV reverse transcriptase (RT)-competitive polymerase chain reaction method (competitive PCR) on the x axis. The gradients for types 1b, 2a, and 3b were greater with ver 2 compared to ver 1. The gradients for types 2a and 3b were the highest: for type 2a, y = 0.135x + 0.6 with ver 1 and y = 0.248x + 0.1 with ver 2; for type 3b, y = 0.366x + 0.1 with ver 1 and y = 0.727x + 0.3 for ver 2. In addition, HCV-RNA counts for all the genotypes tested in this study were significantly higher with ver 2 than with ver 1. Hence, we conclude that ver 2 of the bDNA-probe measures HCV-RNA counts closer to those obtained with competitive PCR than the ver 1 assay.

Spirulina maxima Extract Reduces Obesity through Suppression of Adipogenesis and Activation of Browning in 3T3-L1 Cells and High-Fat Diet-Induced Obese Mice.

PubMed

Seo, Young-Jin; Kim, Kui-Jin; Choi, Jia; Koh, Eun-Jeong; Lee, Boo-Yong

2018-06-01

Obesity predisposes animals towards the metabolic syndrome and diseases such as type 2 diabetes, atherosclerosis, and cardiovascular disease. Spirulina maxima is a microalga with anti-oxidant, anti-cancer, and neuroprotective activities, but the anti-obesity effect of Spirulina maxima 70% ethanol extract (SM70EE) has not yet been fully established. We investigated the effect of SM70EE on adipogenesis, lipogenesis, and browning using in vitro and in vivo obesity models. SM70EE treatment reduced lipid droplet accumulation by the oil red O staining method and downregulated the adipogenic proteins C/EBPα, PPARγ, and aP2, and the lipogenic proteins SREBP1, ACC, FAS, LPAATβ, Lipin1, and DGAT1 by western blot analysis. In addition, the index components of SM70EE, chlorophyll a, and C-phycocyanin, reduced adipogenesis and lipogenesis protein levels in 3T3-L1 and C3H10T1/2 cells. High-fat diet (HFD)-fed mice administered with SM70EE demonstrated smaller adipose depots and lower blood lipid concentrations than control HFD-fed mice. The lower body mass gain in treated SM70EE-administrated mice was associated with lower protein expression of adipogenesis factors and higher expression of AMPKα-induced adipose browning proteins PRDM16, PGC1α, and UCP1. SM70EE administration ameliorates obesity, likely by reducing adipogenesis and activating the thermogenic program, in 3T3-L1 cells and HFD-induced obese mice.

Disruption of the Arabidopsis Defense Regulator Genes SAG101, EDS1, and PAD4 Confers Enhanced Freezing Tolerance

PubMed Central

Chen, Qin-Fang; Xu, Le; Tan, Wei-Juan; Chen, Liang; Qi, Hua; Xie, Li-Juan; Chen, Mo-Xian; Liu, Bin-Yi; Yu, Lu-Jun; Yao, Nan; Zhang, Jian-Hua; Shu, Wensheng; Xiao, Shi

2017-01-01

In Arabidopsis, three lipase-like regulators, SAG101, EDS1, and PAD4, act downstream of resistance protein-associated defense signaling. Although the roles of SAG101, EDS1, and PAD4 in biotic stress have been extensively studied, little is known about their functions in plant responses to abiotic stresses. Here, we show that SAG101, EDS1, and PAD4 are involved in the regulation of freezing tolerance in Arabidopsis. With or without cold acclimation, the sag101, eds1, and pad4 single mutants, as well as their double mutants exhibited similarly enhanced tolerance to freezing temperatures. Upon cold exposure, the sag101, eds1, and pad4 mutants showed increased transcript levels of C-REPEAT/DRE BINDING FACTORs and their regulons, compared with wild type. Moreover, freezing-induced cell death and accumulation of hydrogen peroxide were ameliorated in sag101, eds1, and pad4 mutants. The sag101, eds1, and pad4 mutants had much lower salicylic acid (SA) and diacylglycerol (DAG) contents than wild type and exogenous application of SA and DAG compromised the freezing tolerance of the mutants. Furthermore, SA suppressed the cold-induced expression of DGATs and DGKs in wild-type leaves. These findings indicate that SAG101, EDS1, and PAD4 are involved in freezing response in Arabidopsis, at least in part, by modulating the homeostasis of SA and DAG. PMID:26149542

Diagnostic tools based on minor groove binder probe technology for rapid identification of vaccinal and field strains of canine parvovirus type 2b.

PubMed

Decaro, Nicola; Martella, Vito; Elia, Gabriella; Desario, Costantina; Campolo, Marco; Buonavoglia, Domenico; Bellacicco, Anna Lucia; Tempesta, Maria; Buonavoglia, Canio

2006-12-01

TaqMan-based diagnostic tests have been developed for the identification of canine parvovirus type 2 (CPV-2) strains in the faeces of dogs with diarrhoea, including a minor groove binder (MGB) probe assay for identification of type 2-based vaccines and field strains (types 2a, 2b and 2c). Since type 2b vaccines have been licensed recently in Europe, two novel MGB assays were developed for discrimination between type 2b vaccines and field strains of CPV. Such assays have been found to be highly sensitive, specific and reproducible, allowing for simultaneous detection of type 2b vaccinal and field strains present in the same specimens. These new assays will help resolution of the diagnostic problems related to the detection of a type 2b strain in the faeces of dogs shortly after the administration of a type 2b vaccine.

ASMASE IS REQUIRED FOR CHRONIC ALCOHOL INDUCED HEPATIC ENDOPLASMIC RETICULUM STRESS AND MITOCHONDRIAL CHOLESTEROL LOADING

PubMed Central

Fernandez, Anna; Matias, Núria; Fucho, Raquel; Ribas, Vicente; Von Montfort, Claudia; Nuño, Natalia; Baulies, Anna; Martinez, Laura; Tarrats, Núria; Mari, Montserrat; Colell, Anna; Morales, Albert; Dubuquoy, Laurent; Mathurin, Philippe; Bataller, Ramón; Caballeria, Joan; Elena, Montserrat; Balsinde, Jesus; Kaplowitz, Neil; Garcia-Ruiz, Carmen; Fernandez-Checa, Jose C.

2013-01-01

Background & aims The pathogenesis of alcohol-induced liver disease (ALD) is poorly understood. Here, we examined the role of acid sphingomyelinase (ASMase) in alcohol induced hepatic endoplasmic reticulum (ER) stress, a key mechanism of ALD Methods We examined ER stress, lipogenesis, hyperhomocysteinemia, mitochondrial cholesterol (mChol) trafficking and susceptibility to LPS and concanavalin-A in ASMase−/− mice fed alcohol. Results Alcohol feeding increased SREBP-1c, DGAT-2 and FAS mRNA in ASMase+/+ but not in ASMase−/− mice. Compared to ASMase+/+ mice, ASMase−/− mice exhibited decreased expression of ER stress markers induced by alcohol, but the level of tunicamycin-mediated upregulation of ER stress markers and steatosis was similar in both types of mice. The increase in homocysteine levels induced by alcohol feeding was comparable in both ASMase+/+ mice and ASMase−/− mice. Exogenous ASMase, but not neutral SMase, induced ER stress by perturbing ER Ca2+ homeostasis. Moreover, alcohol-induced mChol loading and StARD1 overexpression were blunted in ASMase−/− mice. Tunicamycin upregulated StARD1 expression and this outcome was abrogated by tauroursodeoxycholic acid. Alcohol-induced liver injury and sensitization to LPS and concanavalin-A were prevented in ASMase−/− mice. These effects were reproduced in alcohol-fed TNFR1/R2−/− mice. Moreover, ASMase does not impair hepatic regeneration following partial hepatectomy. Of relevance, liver samples from patients with alcoholic hepatitis exhibited increased expression of ASMase, StARD1 and ER stress markers. Conclusion Our data indicate that ASMase is critical for alcohol-induced ER stress, and provide a rationale for further clinical investigation in ALD. PMID:23707365

Electronic and elastic properties of new semiconducting oP(12)-type RuB(2) and OsB(2).

PubMed

Hao, Xianfeng; Xu, Yuanhui; Gao, Faming

2011-03-30

Using first-principles total energy calculations we investigate the structural, elastic and electronic properties of new hypothetical oP(12)-type phase RuB(2) and OsB(2). The calculations indicate that the oP(12)-type phase RuB(2) and OsB(2) are thermodynamically and mechanically stable. Remarkably, the new phases RuB(2) and OsB(2) are predicted to be semiconductors, and the appearance of band gaps is ascribed to the enhanced B-B covalent hybridization. Compared to metallic oP(6)-type RuB(2) and OsB(2) phases, the new phases possess similar mechanical properties and hardness. The combination of the probability of tunable electronic properties, strong stiffness and high hardness make RuB(2) and OsB(2) attractive and interesting for advanced applications. © 2011 IOP Publishing Ltd

Validation of markers with non-additive effects on milk yield and fertility in Holstein and Jersey cows.

PubMed

Aliloo, Hassan; Pryce, Jennie E; González-Recio, Oscar; Cocks, Benjamin G; Hayes, Ben J

2015-07-22

It has been suggested that traits with low heritability, such as fertility, may have proportionately more genetic variation arising from non-additive effects than traits with higher heritability, such as milk yield. Here, we performed a large genome scan with 408,255 single nucleotide polymorphism (SNP) markers to identify chromosomal regions associated with additive, dominance and epistatic (pairwise additive × additive) variability in milk yield and a measure of fertility, calving interval, using records from a population of 7,055 Holstein cows. The results were subsequently validated in an independent set of 3,795 Jerseys. We identified genomic regions with validated additive effects on milk yield on Bos taurus autosomes (BTA) 5, 14 and 20, whereas SNPs with suggestive additive effects on fertility were observed on BTA 5, 9, 11, 18, 22, 27, 29 and the X chromosome. We also confirmed genome regions with suggestive dominance effects for milk yield (BTA 2, 3, 5, 26 and 27) and for fertility (BTA 1, 2, 3, 7, 23, 25 and 28). A number of significant epistatic effects for milk yield on BTA 14 were found across breeds. However on close inspection, these were likely to be associated with the mutation in the diacylglycerol O-acyltransferase 1 (DGAT1) gene, given that the associations were no longer significant when the additive effect of the DGAT1 mutation was included in the epistatic model. In general, we observed a low statistical power (high false discovery rates and small number of significant SNPs) for non-additive genetic effects compared with additive effects for both traits which could be an artefact of higher dependence on linkage disequilibrium between markers and causative mutations or smaller size of non-additive effects relative to additive effects. The results of our study suggest that individual non-additive effects make a small contribution to the genetic variation of milk yield and fertility. Although we found no individual mutation with large dominance effect for both traits under investigation, a contribution to genetic variance is still possible from a large number of small dominance effects, so methods that simultaneously incorporate genotypes across all loci are suggested to test the variance explained by dominance gene actions.

Kaempferol suppresses lipid accumulation by inhibiting early adipogenesis in 3T3-L1 cells and zebrafish.

PubMed

Lee, Yeon-Joo; Choi, Hyeon-Son; Seo, Min-Jung; Jeon, Hui-Jeon; Kim, Kui-Jin; Lee, Boo-Yong

2015-08-01

Kaempferol is a flavonoid present in Kaempferia galanga and Opuntia ficus indica var. saboten. Recent studies have suggested that it has anti-oxidant, anti-inflammatory, anti-cancer, and anti-obesity effects. In this study, we focused on the anti-adipogenic effects of kaempferol during adipocyte differentiation. The results showed that kaempferol inhibits lipid accumulation in adipocytes and zebrafish. Oil Red O and Nile Red staining showed that the number of intracellular lipid droplets decreased in adipocytes and zebrafish treated with kaempferol. LPAATθ (lysophosphatidic acid acyltransferase), lipin1, and DGAT1 (triglyceride synthetic enzymes) and FASN and SREBP-1C (fatty acid synthetic proteins) showed decreased expression levels in the presence of kaempferol. In addition, treatment of kaempferol showed an inhibitory activity on cell cycle progression. Kaempferol delayed cell cycle progression from the S to G2/M phase through the regulation of cyclins in a dose-dependent manner. Kaempferol blocked the phosphorylation of AKT (protein kinase B) and mammalian target of rapamycin (mTOR) signaling pathway during the early stages of adipogenesis. In addition, kaempferol down-regulated pro-early adipogenic factors such as CCAAT-enhancer binding proteins β (C/EBPβ), and Krüppel-like factors (KLFs) 4 and 5, while anti-early adipogenic factors, such as KLF2 and pref-1(preadipocyte factor-1), were upregulated. These kaempferol-mediated regulations of early adipogenic factors resulted in the attenuation of late adipogenic factors such as C/EBPα and peroxisome proliferator-activated receptor γ (PPARγ). These results were supported in zebrafish based on the decrease in lipid accumulation and expression of adipogenic factors. Our results indicated that kaempferol might have an anti-obesity effect by regulating lipid metabolism.

Histocompatibility Typing for the Prediction of Susceptibility to Infectious Disease.

DTIC Science & Technology

1980-06-01

w6/A2, B27 , w4, Cwl Sib B A2, A28 87, 818 (w6) blank A28, B7, w6/A2, 818, w6 12 5.2 HLA -DR typing. HLA -DR (B cell) typing will begin in June after...BACKGROUND 3 D. RESEARCH DESIGN AND PLAN 5 E. RESULTS 6 1. Development of Guidelines and Questionnaire- 6 Computer Form 2. Development of an HLA ...Histocompatibility Testing 7 Serology Laboratory 2.1 Establishment of HLA -A,B,C,DR Typing Trays 7 2.2 Establishment of the Two-Color Fluorescence 9 Method of B

Transcriptional changes in organoculture of full-thickness human skin following topical application of all-trans retinoic acid

PubMed Central

Gillbro, J M; Al-Bader, T; Westman, M; Olsson, M J; Mavon, A

2014-01-01

Synopsis Objective Retinoids are used as therapeutic agents for numerous skin diseases, for example, psoriasis, acne and keratinization disorders. The same substances have also been recognized in the treatment for hyperpigmentation disorders such as melasma. Other studies on photo-damaged skin have shown that retinoids reduce wrinkles, surface roughness, mottled pigmentation, and visual skin appearance as a whole. We tested the hypothesis that an organoculture of full-thickness human skin could be used as a preclinical model to investigate the retinoid transcriptional profile in human skin in vitro. Methods Full-thickness skin explants were exposed to topically applied all-trans retinoic acid (RA) for 24 h. The gene expression profile was analysed using oligonucleotide microarrays, and data were validated with real-time (RT) PCR. Results We showed that the expression of 93 genes was significantly altered more than twofold. Several of the altered genes, for example, KRT4, CYP26 and LCN2, have previously been shown to be affected by RA in keratinocyte monocultures, reconstructed epidermis and skin biopsies from patients treated topically or orally with RA. In addition, genes, such as SCEL, NRIP1, DGAT2, RDH12 EfnB2, MAPK14, SAMD9 and CEACAM6 not previously reported to be affected by RA in human skin, were identified for the first time in this study. Conclusion The results in the present study show that full-thickness human explants represent a valuable pre-clinical model for studying the effects of retinoids in skin. Résumé Objectif Les rétinoïdes sont utilisés comme agents thérapeutiques pour de nombreuses maladies de la peau, p.ex. le psoriasis, l'acné et les troubles de la kératinisation. Les mêmes substances ont également été reconnues dans le traitement des troubles de l' hyperpigmentation tels que le melasma. D'autres études sur la peau photo-endommagée ont montré que les rétinoïdes réduisent les rides, la rugosité de la surface, la pigmentation tachetée, et l'aspect visuel de la peau dans son ensemble. Nous avons testé l'hypothèse selon laquelle une organoculture de épaisseur intégrale de la peau humaine pourrait être utilisée comme modèle préclinique pour étudier le profil transcriptionnel des rétinoïdes dans la peau humaine in vitro. Méthodes Des explants de peau intégrale ont été exposés à l'application topique de all-trans acide rétinoïque (RA) pendant 24 heures. Le profil d' expression des gènes a été analysé en utilisant des puces DNA array et les données ont été validées par (RT) -PCR. Resultats Nous avons montré que l'expression de 93 gènes a été modifiée de façon significative par plus d'un facteur 2. Plusieurs des gènes modifiés par exemple KRT4, CYP26 et LCN2 ont été montrés précédemment d'être affectés par RA dans les monocultures de kératinocytes, dans l'épiderme reconstruit et dans des biopsies cutanées de patients traités par voie topique ou par voie orale avec RA. En outre, des gènes tels que SCEL, NRIP1, DGAT2, RDH12 EfnB2, MAPK14, SAMD9 et CEACAM6 non signalés précédemment, sont touchés par RA dans la peau humaine, et ont été identifiés pour la première fois dans cette étude. Conclusion Les résultats de la présente étude montrent que les explants humains de pleine épaisseur représentent un modèle préclinique précieux pour l'étude des effets des rétinoïdes dans la peau. PMID:24697191

The effect of myostatin on proliferation and lipid accumulation in 3T3-L1 preadipocytes.

PubMed

Zhu, Hui Juan; Pan, Hui; Zhang, Xu Zhe; Li, Nai Shi; Wang, Lin Jie; Yang, Hong Bo; Gong, Feng Ying

2015-06-01

Myostatin is a critical negative regulator of skeletal muscle development, and has been reported to be involved in the progression of obesity and diabetes. In the present study, we explored the effects of myostatin on the proliferation and differentiation of 3T3-L1 preadipocytes by using 3-[4,5-dimethylthiazol-2-yl] 2,5-diphenyl tetrazolium bromide spectrophotometry, intracellular triglyceride (TG) assays, and real-time quantitative RT-PCR methods. The results indicated that recombinant myostatin significantly promoted the proliferation of 3T3-L1 preadipocytes and the expression of proliferation-related genes, including Cyclin B2, Cyclin D1, Cyclin E1, Pcna, and c-Myc, and IGF1 levels in the medium of 3T3-L1 were notably upregulated by 35.2, 30.5, 20.5, 33.4, 51.2, and 179% respectively (all P<0.01) in myostatin-treated 3T3-L1 cells. Meanwhile, the intracellular lipid content of myostatin-treated cells was notably reduced as compared with the non-treated cells. Additionally, the mRNA levels of Pparγ, Cebpα, Gpdh, Dgat, Acs1, Atgl, and Hsl were significantly downregulated by 22-76% in fully differentiated myostatin-treated adipocytes. Finally, myostatin regulated the mRNA levels and secretion of adipokines, including Adiponectin, Resistin, Visfatin, and plasminogen activator inhibitor-1 (PAI-1) in 3T3-L1 adipocytes (all P<0.001). Above all, myostatin promoted 3T3-L1 proliferation by increasing the expression of cell-proliferation-related genes and by stimulating IGF1 secretion. Myostatin inhibited 3T3-L1 adipocyte differentiation by suppressing Pparγ and Cebpα expression, which consequently deceased lipid accumulation in 3T3-L1 cells by inhibiting the expression of critical lipogenic enzymes and by promoting the expression of lipolytic enzymes. Finally, myostatin modulated the expression and secretion of adipokines in fully differentiated 3T3-L1 adipocytes. © 2015 Society for Endocrinology.

49 CFR 172.310 - Class 7 (radioactive) materials.

Code of Federal Regulations, 2010 CFR

2010-10-01

... packaging, in letters at least 13 mm (0.5 in) high, with the words “TYPE IP-1,” “TYPE IP-2,” “TYPE IP-3,” “TYPE A,” “TYPE B(U)” or “TYPE B(M),” as appropriate. A package which does not conform to Type IP-1, Type IP-2, Type IP-3, Type A, Type B(U) or Type B(M) requirements may not be so marked. (c) Each...

49 CFR 172.310 - Class 7 (radioactive) materials.

Code of Federal Regulations, 2011 CFR

2011-10-01

... packaging, in letters at least 13 mm (0.5 in) high, with the words “TYPE IP-1,” “TYPE IP-2,” “TYPE IP-3,” “TYPE A,” “TYPE B(U)” or “TYPE B(M),” as appropriate. A package which does not conform to Type IP-1, Type IP-2, Type IP-3, Type A, Type B(U) or Type B(M) requirements may not be so marked. (c) Each...

Maternal High-Fat and High-Salt Diets Have Differential Programming Effects on Metabolism in Adult Male Rat Offspring.

PubMed

Segovia, Stephanie A; Vickers, Mark H; Harrison, Claudia J; Patel, Rachna; Gray, Clint; Reynolds, Clare M

2018-01-01

Maternal high-fat or high-salt diets can independently program adverse cardiometabolic outcomes in offspring. However, there is a paucity of evidence examining their effects in combination on metabolic function in adult offspring. Female Sprague Dawley rats were randomly assigned to either: control (CD; 10% kcal from fat, 1% NaCl), high-salt (SD; 10% kcal from fat, 4% NaCl), high-fat (HF; 45% kcal from fat, 1% NaCl) or high-fat and salt (HFSD; 45% kcal from fat, 4% NaCl) diets 21 days prior to mating and throughout pregnancy and lactation. Male offspring were weaned onto a standard chow diet and were culled on postnatal day 130 for plasma and tissue collection. Adipocyte histology and adipose tissue, liver, and gut gene expression were examined in adult male offspring. HF offspring had significantly greater body weight, impaired insulin sensitivity and hyperleptinemia compared to CD offspring, but these increases were blunted in HFSD offspring. HF offspring had moderate adipocyte hypertrophy and increased expression of the pre-adipocyte marker Dlk1 . There was a significant effect of maternal salt with increased hepatic expression of Dgat1 and Igfb2 . Gut expression of inflammatory ( Il1r1, Tnfα, Il6 , and Il6r ) and renin-angiotensin system ( Agtr1a, Agtr1b ) markers was significantly reduced in HFSD offspring compared to HF offspring. Therefore, salt mitigates some adverse offspring outcomes associated with a maternal HF diet, which may be mediated by altered adipose tissue morphology and gut inflammatory and renin-angiotensin regulation.

CTRP3 attenuates diet-induced hepatic steatosis by regulating triglyceride metabolism

PubMed Central

Peterson, Jonathan M.; Seldin, Marcus M.; Wei, Zhikui; Aja, Susan

2013-01-01

CTRP3 is a secreted plasma protein of the C1q family that helps regulate hepatic gluconeogenesis and is downregulated in a diet-induced obese state. However, the role of CTRP3 in regulating lipid metabolism has not been established. Here, we used a transgenic mouse model to address the potential function of CTRP3 in ameliorating high-fat diet-induced metabolic stress. Both transgenic and wild-type mice fed a high-fat diet showed similar body weight gain, food intake, and energy expenditure. Despite similar adiposity to wild-type mice upon diet-induced obesity (DIO), CTRP3 transgenic mice were strikingly resistant to the development of hepatic steatosis, had reduced serum TNF-α levels, and demonstrated a modest improvement in systemic insulin sensitivity. Additionally, reduced hepatic triglyceride levels were due to decreased expression of enzymes (GPAT, AGPAT, and DGAT) involved in triglyceride synthesis. Importantly, short-term daily administration of recombinant CTRP3 to DIO mice for 5 days was sufficient to improve the fatty liver phenotype, evident as reduced hepatic triglyceride content and expression of triglyceride synthesis genes. Consistent with a direct effect on liver cells, recombinant CTRP3 treatment reduced fatty acid synthesis and neutral lipid accumulation in cultured rat H4IIE hepatocytes. Together, these results establish a novel role for CTRP3 hormone in regulating hepatic lipid metabolism and highlight its protective function and therapeutic potential in attenuating hepatic steatosis. PMID:23744740

New Petrology, Mineral Chemistry and Stable MG Isotope Compositions of an Allende CAI: EK-459-7-2

NASA Technical Reports Server (NTRS)

Jeffcoat, C. R.; Kerekgyarto, A. G.; Lapen, T. J.; Righter, M.; Simon, J. I.; Ross, D. K.

2016-01-01

Calcium-aluminum-rich inclusions (CAIs) are the key to understanding physical and chemical conditions in the nascent solar nebula. These inclusions have the oldest radiometric ages of solar system materials and are composed of phases that are predicted to condense early from a gas of solar composition. Thus, their chemistry and textures record conditions and processes in the earliest stages of development of the solar nebula. Type B inclusions are typically larger and more coarse grained than other types with substantial evidence that many of them were at least partially molten. Type B inclusions are further subdivided into Type B1 (possess thick melilite mantle) and Type B2 (lack melilite mantle). Despite being extensively studied, the origin of the melilite mantles of Type B1 inclusions remains uncertain. We present petrologic and chemical data for a Type B inclusion, EK-459-7-2, that bears features found in both Type B1 and B2 inclusions and likely represents an intermediate between the two types. Detailed studies of more of these intermediate objects may help to constrain models for Type B1 rim formation.

Reduced skeletal muscle inhibitor of kappaB beta content is associated with insulin resistance in subjects with type 2 diabetes: reversal by exercise training.

PubMed

Sriwijitkamol, Apiradee; Christ-Roberts, Christine; Berria, Rachele; Eagan, Phyllis; Pratipanawatr, Thongchai; DeFronzo, Ralph A; Mandarino, Lawrence J; Musi, Nicolas

2006-03-01

Skeletal muscle insulin resistance plays a key role in the pathogenesis of type 2 diabetes. It recently has been hypothesized that excessive activity of the inhibitor of kappaB (IkappaB)/nuclear factor kappaB (NFkappaB) inflammatory pathway is a mechanism underlying skeletal muscle insulin resistance. However, it is not known whether IkappaB/NFkappaB signaling in muscle from subjects with type 2 diabetes is abnormal. We studied IkappaB/NFkappaB signaling in vastus lateralis muscle from six subjects with type 2 diabetes and eight matched control subjects. Muscle from type 2 diabetic subjects was characterized by a 60% decrease in IkappaB beta protein abundance, an indicator of increased activation of the IkappaB/NFkappaB pathway. IkappaB beta abundance directly correlated with insulin-mediated glucose disposal (Rd) during a hyperinsulinemic (40 mU x m(-2) x min(-1))-euglycemic clamp (r = 0.63, P = 0.01), indicating that increased IkappaB/NFkappaB pathway activity is associated with muscle insulin resistance. We also investigated whether reversal of this abnormality could be a mechanism by which training improves insulin sensitivity. In control subjects, 8 weeks of aerobic exercise training caused a 50% increase in both IkappaB alpha and IkappaB beta protein. In subjects with type 2 diabetes, training increased IkappaB alpha and IkappaB beta protein to levels comparable with that of control subjects, and these increments were accompanied by a 40% decrease in tumor necrosis factor alpha muscle content and a 37% increase in insulin-stimulated glucose disposal. In summary, subjects with type 2 diabetes have reduced IkappaB protein abundance in muscle, suggesting excessive activity of the IkappaB/NFkappaB pathway. Moreover, this abnormality is reversed by exercise training.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Singh, Mukhtiyar; Saini, Hardev S.; Thakur, Jyoti

Heusler alloys based thin-films often exhibit a degree of atomic disorder which leads to the lowering of spin polarization in spintronic devices. We present ab-initio calculations of atomic disorder effects on spin polarization and half-metallicity of Mn{sub 2}CoSi inverse Heusler alloy. The five types of disorder in Mn{sub 2}CoSi have been proposed and investigated in detail. The A2{sub a}-type and B2-type disorders destroy the half-metallicity whereas it sustains for all disorders concentrations in DO{sub 3a}- and A2{sub b}-type disorder and for smallest disorder concentration studied in DO{sub 3b}-type disorder. Lower formation energy/atom for A2{sub b}-type disorder than other four disordersmore » in Mn{sub 2}CoSi advocates the stability of this disorder. The total magnetic moment shows a strong dependence on the disorder and the change in chemical environment. The 100% spin polarization even in the presence of disorders explicitly supports that these disorders shall not hinder the use of Mn{sub 2}CoSi inverse Heusler alloy in device applications. - Graphical abstract: Minority-spin gap (E{sub g↓}) and HM gap (E{sub sf}) as a function of concentrations of various possible disorder in Mn{sub 2}CoSi inverse Heusler alloy. The squares with solid line (black color)/dotted line (blue color)/dashed line (red color) reperesents E{sub g↓} for DO{sub 3a}-/DO{sub 3b}-/A2{sub b}-type disorder in Mn{sub 2}CoSi and the spheres with solid line (black color)/dottedline (blue color)/dashed line (red color) represents E{sub sf} for DO{sub 3a}-/DO{sub 3b}-/A2{sub b}-type disorder in Mn{sub 2}CoSi. - Highlights: • The DO{sub 3}- and A2-type disorders do not affect the half-metallicity in Mn{sub 2}CoSi. • The B2-type disorder solely destroys half-metallicity in Mn{sub 2}CoSi. • The A2-type disorder most probable to occur out of all three types. • The total spin magnetic moment strongly depends on the disorder concentrations.« less

Toll-Like Receptor 2 Mediates Cellular Activation by the B Subunits of Type II Heat-Labile Enterotoxins

PubMed Central

Hajishengallis, George; Tapping, Richard I.; Martin, Michael H.; Nawar, Hesham; Lyle, Elizabeth A.; Russell, Michael W.; Connell, Terry D.

2005-01-01

The type II heat-labile enterotoxins (LT-IIa and LT-IIb) of Escherichia coli have an AB5 subunit structure similar to that of cholera toxin (CT) and other type I enterotoxins, despite significant differences in the amino acid sequences of their B subunits and different ganglioside receptor specificities. LT-II holotoxins and their nontoxic B subunits display unique properties as immunological adjuvants distinct from those of CT and its B subunits. In contrast to type II holotoxins, the corresponding pentameric B subunits, LT-IIaB and LT-IIbB, stimulated cytokine release in both human and mouse cells dependent upon Toll-like receptor 2 (TLR2). Induction of interleukin-1β (IL-1β), IL-6, IL-8, or tumor necrosis factor alpha in human THP-1 cells by LT-IIaB or LT-IIbB was inhibited by anti-TLR2 but not by anti-TLR4 antibody. Furthermore, transient expression of TLR1 and TLR2 in human embryonic kidney 293 cells resulted in activation of a nuclear factor-κB-dependent luciferase gene in response to LT-IIaB or LT-IIbB. Moreover, peritoneal macrophages from TLR2-deficient mice failed to respond to LT-IIaB or LT-IIbB, in contrast to wild-type or TLR4-deficient cells. These results demonstrate that besides their established binding to gangliosides, the B subunits of type II enterotoxins also interact with TLR2. Although a ganglioside-nonbinding mutant (T34I) of LT-IIaB effectively induced cytokine release, a phenotypically similar point mutation (T13I) in LT-IIbB abrogated cytokine induction, suggesting a variable requirement for gangliosides as coreceptors in TLR2 agonist activity. TLR2-dependent activation of mononuclear cells by type II enterotoxin B subunits appears to be a novel mechanism whereby these molecules may exert their immunomodulatory and adjuvant activities. PMID:15731031

Modulation of Cholesterol-Related Gene Expression by Dietary Fiber Fractions from Edible Mushrooms.

PubMed

Caz, Víctor; Gil-Ramírez, Alicia; Largo, Carlota; Tabernero, María; Santamaría, Mónica; Martín-Hernández, Roberto; Marín, Francisco R; Reglero, Guillermo; Soler-Rivas, Cristina

2015-08-26

Mushrooms are a source of dietary fiber (DF) with a cholesterol-lowering effect. However, their underlying mechanisms are poorly understood. The effect of DF-enriched fractions from three mushrooms species on cholesterol-related expression was studied in vitro. The Pleurotus ostreatus DF fraction (PDF) was used in mice models to assess its potential palliative or preventive effect against hypercholesterolemia. PDF induced a transcriptional response in Caco-2 cells, suggesting a possible cholesterol-lowering effect. In the palliative setting, PDF reduced hepatic triglyceride likely because Dgat1 was downregulated. However, cholesterol-related biochemical data showed no changes and no relation with the observed transcriptional modulation. In the preventive setting, PDF modulated cholesterol-related genes expression in a manner similar to that of simvastatin and ezetimibe in the liver, although no changes in plasma and liver biochemical data were induced. Therefore, PDF may be useful reducing hepatic triglyceride accumulation. Because it induced a molecular response similar to hypocholesterolemic drugs in liver, further dose-dependent studies should be carried out.

Stabilization of the Ti{sub 3}Co{sub 5}B{sub 2}-type structure for Ti{sub 3−x}Si{sub x}Ru{sub 5}B{sub 2} through Si–Ti substitution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xie, Weiwei, E-mail: weiweix@princeton.edu; Fuccillo, M.K.; Phelan, B.F.

2015-07-15

We report a route for designing and synthesizing Ti{sub 3}Co{sub 5}B{sub 2}-type compounds in the Ti–Ru–B system by using chemical substitution of Si for Ti to decrease the d-electron-based antibonding interactions that it is argued would otherwise drive an instability in this structure for unsubstituted Ti{sub 3}Ru{sub 5}B{sub 2}. Ti{sub 3−x}Si{sub x}Ru{sub 5}B{sub 2} with x=0.75, 1.00 and 1.25 nominal compositions crystalizes in the Ti{sub 3}Co{sub 5}B{sub 2} structure type using arc melting methods, whereas at lower doping levels (x=0.0, 0.25 and 0.50) the more complex Zn{sub 11}Rh{sub 18}B{sub 8}-type structure is stable. Electronic structure calculations show that in hypothetical,more » unsubstituted Ti{sub 3}Ru{sub 5}B{sub 2} with the Ti{sub 3}Co{sub 5}B{sub 2}-type structure, the antibonding interactions are strong around the Fermi level between the Ti and Ru in the structure that form tetragonal prisms. We propose that weakening these strong interactions through the partial substitution of isovalent Si for Ti leads to the observed stability of the Ti{sub 3}Co{sub 5}B{sub 2}-type structure for Ti{sub 3−x}Si{sub x}Ru{sub 5}B{sub 2} for x≈1. - Graphical abstract: We present the designing and synthesizing of Ti{sub 3}Co{sub 5}B{sub 2}-type compounds in the Ti–Ru–B system by using chemical substitution of Si for Ti to decrease the d-electron-based antibonding interactions that would otherwise drive an instability in this structure for unsubstituted Ti{sub 3}Ru{sub 5}B{sub 2}. Electronic structure calculations show that in hypothetical, unsubstituted Ti{sub 3}Ru{sub 5}B{sub 2} with the Ti{sub 3}Co{sub 5}B{sub 2}-type structure, the antibonding interactions are strong around the Fermi level between the Ti and Ru in the structure that form tetragonal prisms. We propose that weakening these strong interactions through the partial substitution of isovalent Si for Ti leads to the observed stability of the Ti{sub 3}Co{sub 5}B{sub 2}-type structure for Ti{sub 3−x}Si{sub x}Ru{sub 5}B{sub 2} for x≈1. - Highlights: • New quaternary phase Ti{sub 3−x}Si{sub x}Ru{sub 5}B{sub 2} in Ti{sub 3}Co{sub 5}B{sub 2}-type structure is reported. • Chemical substitution of isovalent Si for Ti is used to stabilize the phase. • Decreasing the d-electron-based antibonding interactions is proved by calculation. • Physical properties of Ti{sub 3−x}Si{sub x}Ru{sub 5}B{sub 2} are presented down to 0.4 K.« less

Comparison of porcine circovirus type 2 (PCV2)-associated lesions produced by co-infection between two genotypes of PCV2 and two genotypes of porcine reproductive and respiratory syndrome virus.

PubMed

Park, Changhoon; Seo, Hwi Won; Park, Su-Jin; Han, Kiwon; Chae, Chanhee

2014-11-01

The objective of this study was to compare the virulence and pathogenicity of a combination of concurrent infections of two genotypes of porcine circovirus type 2 (PCV2) and two genotypes of porcine reproductive and respiratory syndrome virus (PRRSV) in terms of PCV2 viraemia, and PCV2-associated lesions and antigens in co-infected pigs. Pigs with PCV2a (or 2b)/type 1 (or type 2) PRRSV had significantly (P<0.05) higher mean clinical respiratory scores and lower average daily weight gain compared with pigs with PCV2a (or 2b). Co-infection induced significantly lower levels of anti-PCV2 and anti-PRRSV IgG antibodies than infection with one genotype alone, regardless of the genotype of the two viruses. Pigs with PCV2a (or 2b)/type 2 PRRSV had significantly (P<0.05) higher levels of PCV2 viraemia, more severe PCV2-associated lesions, and more PCV2 DNA within the lesions compared with pigs with PCV2a (or 2b)/type 1 PRRSV. However, there was no significant difference in these parameters in pigs with PCV2a/type 2 PRRSV or PCV2b/type 2 PRRSV. The results of this study demonstrate significant differences in the virulence and pathogenicity of type 1 and type 2 PRRSV but no significant differences in the virulence and pathogenicity of PCV2a and PCV2b with respect to the production of PCV2-associated lesions. © 2014 The Authors.

Comparison of type 2 diabetes mellitus incidence in different phases of hepatitis B virus infection: A meta-analysis.

PubMed

Shen, Yi; Zhang, Sheng; Wang, Xulin; Wang, Yuanyuan; Zhang, Jian; Qin, Gang; Li, Wenchao; Ding, Kun; Zhang, Lei; Liang, Feng

2017-10-01

Because whether hepatitis B virus infection increases the risk of type 2 diabetes mellitus has been a controversial topic, pair-wise and network meta-analyses of published literature were carried out to accurately evaluate the association between different phases of hepatitis B virus infection and the risk of type 2 diabetes mellitus. A comprehensive literature retrieval was conducted from the PubMed, Embase, Cochrane Library and Chinese Database to identify epidemiological studies on the association between hepatitis B virus infection and the risk of type 2 diabetes mellitus that were published from 1999 to 2015. A pair-wise meta-analysis of direct evidence was performed to estimate the pooled odds ratios and 95% confidence intervals. A network meta-analysis was conducted, including the construction of a network plot, inconsistency plot, predictive interval plot, comparison-adjusted funnel plot and rank diagram, to graphically link the direct and indirect comparisons between different hepatitis B virus infective phases. Eighteen publications (n=113 639) describing 32 studies were included in this meta-analysis. In the pair-wise meta-analysis, the pooled odds ratio for type 2 diabetes mellitus in chronic hepatitis B cirrhosis patients was 1.76 (95% confidence interval: 1.44-2.14) when compared with non-cirrhotic chronic hepatitis B patients. In the network meta-analysis, six comparisons of four hepatitis B virus infectious states indicated the following descending order for the risk of type 2 diabetes mellitus: hepatitis B cirrhosis patients, non-cirrhotic chronic hepatitis B patients, hepatitis B virus carriers and non-hepatitis B virus controls. This study suggests that hepatitis B virus infection is not an independent risk factor for type 2 diabetes mellitus, but the development of cirrhosis may increase the incidence of type 2 diabetes mellitus cirrhosis. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Using Factor Mixture Models to Evaluate the Type A/B Classification of Alcohol Use Disorders in a Heterogeneous Treatment Sample

PubMed Central

Hildebrandt, Tom; Epstein, Elizabeth E.; Sysko, Robyn; Bux, Donald A.

2017-01-01

Background The type A/B classification model for alcohol use disorders (AUDs) has received considerable empirical support. However, few studies examine the underlying latent structure of this subtyping model, which has been challenged as a dichotomization of a single drinking severity dimension. Type B, relative to type A, alcoholics represent those with early age of onset, greater familial risk, and worse outcomes from alcohol use. Method We examined the latent structure of the type A/B model using categorical, dimensional, and factor mixture models in a mixed gender community treatment-seeking sample of adults with an AUD. Results Factor analytic models identified 2-factors (drinking severity/externalizing psychopathology and internalizing psychopathology) underlying the type A/B indicators. A factor mixture model with 2-dimensions and 3-classes emerged as the best overall fitting model. The classes reflected a type A class and two type B classes (B1 and B2) that differed on the respective level of drinking severity/externalizing pathology and internalizing pathology. Type B1 had a greater prevalence of women and more internalizing pathology and B2 had a greater prevalence of men and more drinking severity/externalizing pathology. The 2-factor, 3-class model also exhibited predictive validity by explaining significant variance in 12-month drinking and drug use outcomes. Conclusions The model identified in the current study may provide a basis for examining different sources of heterogeneity in the course and outcome of AUDs. PMID:28247423

Improving Fatty Acid Availability for Bio-Hydrocarbon Production in Escherichia coli by Metabolic Engineering

PubMed Central

Lin, Fengming; Chen, Yu; Levine, Robert; Lee, Kilho; Yuan, Yingjin; Lin, Xiaoxia Nina

2013-01-01

Previous studies have demonstrated the feasibility of producing fatty-acid-derived hydrocarbons in Escherichia coli. However, product titers and yields remain low. In this work, we demonstrate new methods for improving fatty acid production by modifying central carbon metabolism and storing fatty acids in triacylglycerol. Based on suggestions from a computational model, we deleted seven genes involved in aerobic respiration, mixed-acid fermentation, and glyoxylate bypass (in the order of cyoA, nuoA, ndh, adhE, dld, pta, and iclR) to modify the central carbon metabolic/regulatory networks. These gene deletions led to increased total fatty acids, which were the highest in the mutants containing five or six gene knockouts. Additionally, when two key enzymes in the fatty acid biosynthesis pathway were over-expressed, we observed further increase in strain △cyoA△adhE△nuoA△ndh△pta△dld, leading to 202 mg/g dry cell weight of total fatty acids, ~250% of that in the wild-type strain. Meanwhile, we successfully introduced a triacylglycerol biosynthesis pathway into E. coli through heterologous expression of wax ester synthase/acyl-coenzyme:diacylglycerol acyltransferase (WS/DGAT) enzymes. The added pathway improved both the amount and fuel quality of the fatty acids. These new metabolic engineering strategies are providing promising directions for future investigation. PMID:24147139

Determination of internal controls for quantitative gene expression of Isochrysis zhangjiangensis at nitrogen stress condition

NASA Astrophysics Data System (ADS)

Wu, Shuang; Zhou, Jiannan; Cao, Xupeng; Xue, Song

2016-02-01

Isochrysis zhangjiangensis is a potential marine microalga for biodiesel production, which accumulates lipid under nitrogen limitation conditions, but the mechanism on molecular level is veiled. Quantitative real-time polymerase chain reaction (qPCR) provides the possibility to investigate the gene expression levels, and a valid reference for data normalization is an essential prerequisite for firing up the analysis. In this study, five housekeeping genes, actin (ACT), α-tubulin (TUA), ß-tubulin (TUB), ubiquitin (UBI), 18S rRNA (18S) and one target gene, diacylglycerol acyltransferase (DGAT), were used for determining the reference. By analyzing the stabilities based on calculation of the stability index and on operating the two types of software, geNorm and bestkeeper, it showed that the reference genes widely used in higher plant and microalgae, such as UBI, TUA and 18S, were not the most stable ones in nitrogen-stressed I. zhangjiangensis, and thus are not suitable for exploring the mRNA expression levels under these experimental conditions. Our results show that ACT together with TUB is the most feasible internal control for investigating gene expression under nitrogen-stressed conditions. Our findings will contribute not only to future qPCR studies of I. zhangjiangensis, but also to verification of comparative transcriptomics studies of the microalgae under similar conditions.

Resonant enhancement of band-to-band tunneling in in-plane MoS2/WS2 heterojunctions

NASA Astrophysics Data System (ADS)

Kuroda, Tatsuya; Mori, Nobuya

2018-04-01

The band-to-band (BTB) tunneling current J through in-plane MoS2/WS2 heterojunctions is calculated by the nonequilibrium Green function method combined with tight-binding approximation. Types A and B of band configurations are considered. For type-A (type-B) heterojunctions, a potential notch exists (or is absent) at the heterointerface. Both type-A and type-B MoS2/WS2 heterojunctions can support a higher BTB current than MoS2 and WS2 homojunctions. For type-A heterojunctions, the resonant enhancement of J occurs resulting in a significantly higher BTB tunneling current.

Pb(B{sup {prime}}{sub 1/2}B{sup {prime}{prime}}{sub 1/2})O{sub 3}-type perovskites: Part II. Short-range order parameter as a criterion of the distinction between relaxor and normal ferroelectrics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, S.; Jang, H.M.

1997-08-01

A classification scheme of Pb(B{sup {prime}}{sub 1/2}B{sup {prime}{prime}}{sub 1/2})O{sub 3}-type perovskites with respect to the B-site order parameters was proposed based on the theoretical calculation of the short-range order parameter ({sigma}) using the pair-correlation model. The calculated order parameters predict that a Pb(B{sup {prime}}{sub 1/2}B{sup {prime}{prime}}{sub 1/2})O{sub 3}-type perovskite without any charge difference between B{sup {prime}} and B{sup {prime}{prime}} cations [e.g., Pb(Zr{sub 1/2}Ti{sub 1/2})O{sub 3} (PZT)] is represented by a completely disordered state with the absence of a finite coherence length. On the other hand, a Pb(B{sup {prime}}{sub 1/2}B{sup {prime}{prime}}{sub 1/2})O{sub 3} type perovskite system having different ionic charges ismore » characterized either by the short-range ordering with a nanoscale coherence length or by the macroscopic long-range ordering, depending on the magnitude of ionic charge difference between B{sup {prime}} and B{sup {prime}{prime}} ions. The normal ferroelectricity in Pb(B{sup {prime}}{sub 1/2}B{sup {prime}{prime}}{sub 1/2})O{sub 3}-type complex perovskites was then correlated either with a completely disordered state ({sigma}=0) or with a perfectly ordered state ({sigma}=1), whereas the relaxor behavior was attributed to the nanoscale short-range ordering (0{lt}{sigma}{lt}1) in the configuration of the B-site cations. {copyright} {ital 1997 Materials Research Society.}« less

Platelet-type von Willebrand Disease: Diagnostic Challenges. Flaws and Pitfalls Experienced in the THROMKID Quality Project.

PubMed

Maurer, M; Mesters, R; Schneppenheim, R; Knoefler, R; Streif, W

2015-05-01

Primary haemostasis defects comprise von Willebrand disease (VWD) and platelet disorders (PD). Although presenting with mild to moderate bleeding tendency in most cases, severe bleeding and blood loss may occur unexpectedly in trauma and surgery. Diagnosis of VWD and PD often remains difficult owing to the wide spectrum of clinical and laboratory manifestations. Platelet-type von Willebrand disease (PT-VWD) is frequently misdiagnosed as type 2B VWD. Discrimination between type 2B VWD and PT-VWD is crucial as treatment differs. A literature review revealed difficulties in diagnostic work-up and choice of optimal treatment of PT-VWD. Guidelines favour the therapeutic use of platelet concentrates. A telephone survey of diagnostic practice with regard to type 2B VWD/PT-VWD was conducted. The prevalence and incidence of type 2B and PT-VWD remained unclear, but PT-VWD may be underestimated. An international study estimated that PT-VWD constitutes up to 15% of the total number of patients diagnosed with type 2B VWD. Our survey confirmed difficulties with diagnosis and showed that some centres did not exclude PT-VWD in type 2B patients. Some authors emphasize that genetic testing is the gold standard for diagnosis, but functional testing allows immediate diagnosis. Due to the important therapeutic implications we suggest that type 2B VWD be confirmed by genetic testing and that in case of a negative result PT-VWD should be excluded. PT-VWD should be excluded in all suspected cases of type 2B. PT-VWD should be treated with platelet concentrates. © Georg Thieme Verlag KG Stuttgart · New York.

Developmental bisphenol A (BPA) exposure leads to sex-specific modification of hepatic gene expression and epigenome at birth that may exacerbate high-fat diet-induced hepatic steatosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Strakovsky, Rita S.; Wang, Huan; Engeseth, Nicki J.

Developmental bisphenol A (BPA) exposure increases adulthood hepatic steatosis with reduced mitochondrial function. To investigate the potential epigenetic mechanisms behind developmental BPA-induced hepatic steatosis, pregnant Sprague–Dawley rats were dosed with vehicle (oil) or BPA (100 μg/kg/day) from gestational day 6 until postnatal day (PND) 21. After weaning, offspring were either challenged with a high-fat (HF; 45% fat) or remained on a control (C) diet until PND110. From PND60 to 90, both BPA and HF diet increased the fat/lean ratio in males only, and the combination of BPA and HF diet appeared to cause the highest ratio. On PND110, Oil-HF, BPA-C,more » and BPA-HF males had higher hepatic lipid accumulation than Oil-C, with microvesicular steatosis being marked in the BPA-HF group. Furthermore, on PND1, BPA increased and modified hepatic triglyceride (TG) and free fatty acid (FFA) compositions in males only. In PND1 males, BPA increased hepatic expression of FFA uptake gene Fat/Cd36, and decreased the expression of TG synthesis- and β-oxidation-related genes (Dgat, Agpat6, Cebpα, Cebpβ, Pck1, Acox1, Cpt1a, Cybb). BPA altered DNA methylation and histone marks (H3Ac, H4Ac, H3Me2K4, H3Me3K36), and decreased the binding of several transcription factors (Pol II, C/EBPβ, SREBP1) within the male Cpt1a gene, the key β-oxidation enzyme. In PND1 females, BPA only increased the expression of genes involved in FFA uptake and TG synthesis (Lpl, Fasn, and Dgat). These data suggest that developmental BPA exposure alters and reprograms hepatic β-oxidation capacity in males, potentially through the epigenetic regulation of genes, and further alters the response to a HF diet. - Highlights: • Developmental BPA exposure exacerbates HF-diet induced steatosis in adult males. • Gestational BPA exposure increases hepatic lipid accumulation in neonatal males. • BPA decreases Cpt1a and other hepatic β-oxidation genes in neonatal males. • BPA alters neonatal male Cpt1a DNA methylation, histones, and transcription factors.« less

A strontium and neodymium isotopic study of Apollo 17 high-Ti mare basalts: Resolution of ages, evolution of magmas, and origins of source heterogeneities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paces, J.B.; Neal, C.R.; Taylor, L.A.

1991-07-01

A combined Sr and Nd isotopic study of 15 Apollo 17 high-Ti mare basalts was undertaken to investigate geochronological and compositional differences between previously identified magma types (A, B1, B2, and C). Whole-rock and mineral separates for one of the least-evolved Type B1 basalts, 70139, yield Sm-Nd and Rb-Sr isochron ages of 3.71 {plus minus} 0.12 Ga and 3.65 {plus minus} 0.07 Ga and a Rb-Sr isochron age of 3.67 {plus minus} 0.10 Ga. Although these two ages are non-resolvable by themselves, compilation of all available geochronological data allows resolution of Type A and B1/B2 ages at high levels ofmore » confidence (> 99%). The most reliably dated samples, classified according to their geochemical type, yield weighted average ages of 3.75 {plus minus} 0.02 Ga for Type A (N = 4) and 3.69 {plus minus} 0.02 Ga for Type B1/B2 (N = 3) basalts. Insufficient geochronological data are available to place the rare, Type C basalts within this stratigraphy. The authors propose that age differences correlate with geochemical magma type, and that early magmatism was dominated by eruption of Type A basalts while later activity was dominated by effusion of Type B1 and B2 basalts.« less

Targeting VEGF-B as a novel treatment for insulin resistance and type 2 diabetes.

PubMed

Hagberg, Carolina E; Mehlem, Annika; Falkevall, Annelie; Muhl, Lars; Fam, Barbara C; Ortsäter, Henrik; Scotney, Pierre; Nyqvist, Daniel; Samén, Erik; Lu, Li; Stone-Elander, Sharon; Proietto, Joseph; Andrikopoulos, Sofianos; Sjöholm, Ake; Nash, Andrew; Eriksson, Ulf

2012-10-18

The prevalence of type 2 diabetes is rapidly increasing, with severe socioeconomic impacts. Excess lipid deposition in peripheral tissues impairs insulin sensitivity and glucose uptake, and has been proposed to contribute to the pathology of type 2 diabetes. However, few treatment options exist that directly target ectopic lipid accumulation. Recently it was found that vascular endothelial growth factor B (VEGF-B) controls endothelial uptake and transport of fatty acids in heart and skeletal muscle. Here we show that decreased VEGF-B signalling in rodent models of type 2 diabetes restores insulin sensitivity and improves glucose tolerance. Genetic deletion of Vegfb in diabetic db/db mice prevented ectopic lipid deposition, increased muscle glucose uptake and maintained normoglycaemia. Pharmacological inhibition of VEGF-B signalling by antibody administration to db/db mice enhanced glucose tolerance, preserved pancreatic islet architecture, improved β-cell function and ameliorated dyslipidaemia, key elements of type 2 diabetes and the metabolic syndrome. The potential use of VEGF-B neutralization in type 2 diabetes was further elucidated in rats fed a high-fat diet, in which it normalized insulin sensitivity and increased glucose uptake in skeletal muscle and heart. Our results demonstrate that the vascular endothelium can function as an efficient barrier to excess muscle lipid uptake even under conditions of severe obesity and type 2 diabetes, and that this barrier can be maintained by inhibition of VEGF-B signalling. We propose VEGF-B antagonism as a novel pharmacological approach for type 2 diabetes, targeting the lipid-transport properties of the endothelium to improve muscle insulin sensitivity and glucose disposal.

A family with autosomal dominant mutilating neuropathy not linked to either Charcot-Marie-Tooth disease type 2B (CMT2B) or hereditary sensory neuropathy type I (HSN I) loci.

PubMed

Bellone, Emilia; Rodolico, Carmelo; Toscano, Antonio; Di Maria, Emilio; Cassandrini, Denise; Pizzuti, Antonio; Pigullo, Simona; Mazzeo, Anna; Macaione, Vincenzo; Girlanda, Paolo; Vita, Giuseppe; Ajmar, Franco; Mandich, Paola

2002-03-01

Sensory loss and ulcero-mutilating features have been observed in hereditary sensory neuropathy type I and in hereditary motor and sensory neuropathy type IIB, also referred as Charcot-Marie-Tooth disease type 2B. To date two loci associated with ulcero-mutilating neuropathy have been described: CMT2B at 3q13-q22 and HSN I at 9q22.1-q22.3. We performed linkage analysis with chromosomal markers representing the hereditary sensory neuropathy type I and Charcot-Marie-Tooth disease type 2B loci on an Italian family with a severe distal sensory loss leading to an ulcero-mutilating peripheral neuropathy. Negative likelihood-of-odds scores excluded any evidence of linkage to both chromosome 3q13 and chromosome 9q22 markers, confirming the genetic heterogeneity of this clinical entity and the presence of a third locus responsible for ulcero-mutilating neuropathies.

MicroRNA-200a regulates adipocyte differentiation in the domestic yak Bos grunniens.

PubMed

Zhang, Yongfeng; Wu, Xiaoyun; Liang, Chunnian; Bao, Pengjia; Ding, Xuezhi; Chu, Min; Jia, Congjun; Guo, Xian; Yan, Ping

2018-04-15

The domestic yak (Bos grunniens) is a culturally important animal that lives at high altitude and is farmed by Tibetan herders for its meat, milk, and other animal by-products. Within the animal, adipose tissue is an important store and source of energy and is used to maintain adequate body temperature during the extended cold seasons. Exploring the biomolecular role of microRNAs (miRNAs) in the regulation of growth, development, and metabolism of yak adipocytes may provide valuable insights into the physiology of adipogenesis in the yak. This study investigated whether and how miR-200a (a miRNA recently reported to promote adipogenesis in ST2 bone marrow stromal cells) regulates adipocyte differentiation in the yak. Expression levels of miR-200a gradually increased during day 0 to day 8 of adipocyte differentiation, and transfection of adipocytes with miR-200a enhanced lipid accumulation and triglyceride content compared to control (un-transfected) adipocytes. We additionally verified (using qRT-PCR analysis) that miR-200a increased the expression of adipocyte-specific genes involved in lipogenic transcription (PPARγ, ELVOL, and C/EBPα), fatty acid synthesis (ACC, ACS, SCD, and FAS), and fatty acid transport (DGAT, LPL, and FABP4). We also found that transfection of adipocytes with miR-200a resulted in suppression of the levels of noncanonical Wnt signaling transcription factors (Wnt5a, TAK1, and NLK). These results indicate that miRNA-200a plays an important role in promoting yak adipocyte differentiation that may operate via the suppression of noncanonical Wnt signaling. Copyright © 2018 Elsevier B.V. All rights reserved.

The risk for type B aortic dissection in Marfan syndrome.

PubMed

den Hartog, Alexander W; Franken, Romy; Zwinderman, Aeilko H; Timmermans, Janneke; Scholte, Arthur J; van den Berg, Maarten P; de Waard, Vivian; Pals, Gerard; Mulder, Barbara J M; Groenink, Maarten

2015-01-27

Aortic dissections involving the descending aorta are a major clinical problem in patients with Marfan syndrome. The purpose of this study was to identify clinical parameters associated with type B aortic dissection and to develop a risk model to predict type B aortic dissection in patients with Marfan syndrome. Patients with the diagnosis of Marfan syndrome and magnetic resonance imaging or computed tomographic imaging of the aorta were followed for a median of 6 years for the occurrence of type B dissection or the combined end point of type B aortic dissection, distal aortic surgery, and death. A model using various clinical parameters as well as genotyping was developed to predict the risk for type B dissection in patients with Marfan syndrome. Between 1998 and 2013, 54 type B aortic dissections occurred in 600 patients with Marfan syndrome (mean age 36 ± 14 years, 52% male). Independent variables associated with type B aortic dissection were prior prophylactic aortic surgery (hazard ratio: 2.1; 95% confidence interval: 1.2 to 3.8; p = 0.010) and a proximal descending aorta diameter ≥27 mm (hazard ratio: 2.2; 95% confidence interval: 1.1 to 4.3; p = 0.020). In the risk model, the 10-year occurrence of type B aortic dissection in low-, moderate-, and high-risk patients was 6%, 19%, and 34%, respectively. Angiotensin II receptor blocker therapy was associated with fewer type B aortic dissections (hazard ratio: 0.3; 95% confidence interval: 0.1 to 0.9; p = 0.030). Patients with Marfan syndrome with prior prophylactic aortic surgery are at substantial risk for type B aortic dissection, even when the descending aorta is only slightly dilated. Angiotensin II receptor blocker therapy may be protective in the prevention of type B aortic dissections. Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Deciphering signature of selection affecting beef quality traits in Angus cattle.

PubMed

Taye, Mengistie; Yoon, Joon; Dessie, Tadelle; Cho, Seoae; Oh, Sung Jong; Lee, Hak-Kyo; Kim, Heebal

2018-01-01

Artificial selection towards a desired phenotype/trait has modified the genomes of livestock dramatically that generated breeds that greatly differ in morphology, production and environmental adaptation traits. Angus cattle are among the famous cattle breeds developed for superior beef quality. This paper aimed at exploring genomic regions under selection in Angus cattle that are associated with meat quality traits and other associated phenotypes. The whole genome of 10 Angus cattle was compared with 11 Hanwoo (A-H) and 9 Jersey (A-J) cattle breeds using a cross-population composite likelihood ratio (XP-CLR) statistical method. The top 1% of the empirical distribution was taken as significant and annotated using UMD3.1. As a result, 255 and 210 genes were revealed under selection from A-H and A-J comparisons, respectively. The WebGestalt gene ontology analysis resulted in sixteen (A-H) and five (A-J) significantly enriched KEGG pathways. Several pathways associated with meat quality traits (insulin signaling, type II diabetes mellitus pathway, focal adhesion pathway, and ECM-receptor interaction), and feeding efficiency (olfactory transduction, tight junction, and metabolic pathways) were enriched. Genes affecting beef quality traits (e.g., FABP3, FTO, DGAT2, ACS, ACAA2, CPE, TNNI1), stature and body size (e.g., PLAG1, LYN, CHCHD7, RPS20), fertility and dystocia (e.g., ESR1, RPS20, PPP2R1A, GHRL, PLAG1), feeding efficiency (e.g., PIK3CD, DNAJC28, DNAJC3, GHRL, PLAG1), coat color (e.g., MC1-R) and genetic disorders (e.g., ITGB6, PLAG1) were found to be under positive selection in Angus cattle. The study identified genes and pathways that are related to meat quality traits and other phenotypes of Angus cattle. The findings in this study, after validation using additional or independent dataset, will provide useful information for the study of Angus cattle in particular and beef cattle in general.

Adaptations to excess choline in insulin resistant and Pcyt2 deficient skeletal muscle.

PubMed

Taylor, Adrian; Schenkel, Laila Cigana; Yokich, Maiya; Bakovic, Marica

2017-04-01

It was hypothesized that choline supplementation in insulin resistant (IR) CTP:phosphoethanolamine cytidylyltransferase deficient (Pcyt2 +/- ) mice would ameliorate muscle function by remodeling glucose and fatty acid (FA) metabolism. Pcyt2 +/- mice either received no treatment or were allowed access to 2 mg/mL choline in drinking water for 4 weeks. Skeletal muscle was harvested from choline treated and untreated mice. Lipid analysis and metabolic gene expression and signaling pathways were compared between untreated Pcyt2 +/- mice, treated Pcyt2 +/- mice, and Pcyt2 +/+ mice. The major positive effect of choline supplementation on IR muscle was the reduction of glucose utilization for FA and triglyceride (TAG) synthesis and increased muscle glucose storage as glycogen. Choline reduced the expression of genes for FA and TAG formation (Scd1, Fas, Srebp1c, Dgat1/2), upregulated the genes for FA oxidation (Cpt1, Pparα, Pgc1α), and had minor effects on phospholipid and lipolysis genes. Pcyt2 +/- muscle had reduced insulin signaling (IRS1), autophagy (LC3), and choline transport (CTL1) proteins that were restored by choline treatment. Additionally, choline activated AMPK and Akt while inhibiting mTORC1 phosphorylation. These data established that choline supplementation could restore muscle glucose metabolism by reducing lipogenesis and improving mitochondrial and intracellular signaling for protein and energy metabolism in insulin resistant Pcyt2 deficient mice.

Rutin exhibits hepatoprotective effects in a mouse model of non-alcoholic fatty liver disease by reducing hepatic lipid levels and mitigating lipid-induced oxidative injuries.

PubMed

Liu, Qingsheng; Pan, Ran; Ding, Lei; Zhang, Fuli; Hu, Linfeng; Ding, Bin; Zhu, Linwensi; Xia, Yongliang; Dou, Xiaobing

2017-08-01

Nonalcoholic fatty liver disease (NAFLD) is characterized by excessive accumulation of hepatic lipids and oxidative injury of hepatocytes. Rutin is a natural flavonoid with significant roles in combating cellular oxidative stress and regulating lipid metabolism. The current study aims to investigate the molecular mechanisms underlying rutin's hypolipidemic and hepatoprotective effects in nonalcoholic fatty liver disease. Rutin treatment was applied to male C57BL/6 mice maintained on a high-fat diet and HepG2 cells challenged with oleic acid. Hepatic lipid accumulation was evaluated by triglyceride assay and Oil Red O staining. Oxidative hepatic injury was assessed by malondialdehyde assay, superoxide dismutase assay and reactive oxygen species assay. The expression levels of various lipogenic and lipolytic genes were determined by quantitative real-time polymerase chain reactions. In addition, liver autophagy was investigated by enzyme-linked immunosorbent assay. In both fat-challenged murine liver tissues and HepG2 cells, rutin treatment was shown to significantly lower triglyceride content and the abundance of lipid droplets. Rutin was also found to reduce cellular malondialdehyde level and restore superoxide dismutase activity in hepatocytes. Among the various lipid-related genes, rutin treatment was able to restore the expression of peroxisome proliferator-activated receptor alpha (PPAR-α) and its downstream targets, carnitine palmitoyltransferase 1 and 2 (CPT-1 and CPT-2), while suppressing those of sterol regulatory element-binding protein 1c (SREBP-1c), diglyceride acyltransfase 1 and 2 (DGAT-1 and 2), as well as acyl-CoA carboxylase (ACC). In addition, rutin was shown to repress the autophagic function of liver tissues by down-regulating key autophagy biomarkers, including tumor necrosis factor alpha (TNF-α), interleukin 1 beta (IL-1β). The experimental data demonstrated that rutin could reduce triglyceride content and mitigate oxidative injuries in fat-enriched hepatocytes. The hypolipidemic properties of rutin could be attributed to its ability to simultaneously facilitate fatty acid metabolism and inhibit lipogenesis. Copyright © 2017 Elsevier B.V. All rights reserved.

Concentrations of Water-Soluble Vitamins in Blood and Urinary Excretion in Patients with Diabetes Mellitus.

PubMed

Iwakawa, Hiromi; Nakamura, Yasuyuki; Fukui, Tomiho; Fukuwatari, Tsutomu; Ugi, Satoshi; Maegawa, Hiroshi; Doi, Yukio; Shibata, Katsumi

2016-01-01

We examined the concentrations of water-soluble vitamins in blood and urinary excretion of 22 patients with type 2 diabetes mellitus (type 2DM) and 20 healthy control participants. Macronutrient and vitamin intakes of type 2DM subjects were measured using a weighed food record method. Control participants consumed a semipurified diet for eight days. Multiple linear regression models were used to determine whether significant differences existed in vitamin concentrations in blood independent of age, sex, and other confounding factors. Concentrations of vitamins B2, B6, C, niacin, and folate in blood were significantly lower in type 2DM subjects than in controls, independent of confounding factors. Renal clearances of vitamins B6, C, niacin, and folate were significantly higher in type 2DM subjects than in controls. In conclusion, concentrations of vitamins B2, B6, C, niacin, and folate in blood were significantly lower in type 2DM subjects than in controls, independent of confounding factors; based on the evidence of increased urinary clearance of these vitamins, the lower levels were likely due to impaired reabsorption processes.

Endovascular treatment of patients with types A and B thoracic aortic dissection using Relay thoracic stent-grafts: results from the RESTORE Patient Registry.

PubMed

Zipfel, Burkhart; Czerny, Martin; Funovics, Martin; Coppi, Gioacchino; Ferro, Carlo; Rousseau, Hervé; Berti, Sergio; Tealdi, Domenico G; Riambau, Vincent; Mangialardi, Nicola; Sassi, Carlo

2011-04-01

To evaluate the safety and performance of Relay stent-grafts in patients with acute or chronic aortic dissections. Patients with types A or B aortic dissections suitable for treatment with Relay stent-grafts and followed for 2 years after thoracic endovascular aortic repair (TEVAR) were identified from a company-sponsored registry database established in January 2006. Ninety-one consecutive patients (69 men; mean age 65 years) underwent TEVAR with Relay stent-grafts for dissection. Most patients (76, 84%) had type B dissections; 61 of all patients were classified as chronic and 30 as acute. The technical success rate was 95% (97% in acute, 95% in chronic, and 93% in type B dissections). The type I endoleak rate was 7% (7% in acute and 8% in chronic dissections); all occurred in patients with type B dissections. Paraplegia, paraparesis, and stroke occurred in 4, 1, and 2 patients, respectively; 2 cases of paraplegia occurred in patients with acute type B dissections. Thirty-day mortality was 8% (13% in acute and 5% in chronic dissections); all deaths occurred in patients with type B dissections. The 2-year survival rate was 82% in the overall population and 84% in patients with type B dissections. The combination of Relay's features, such as stent conformability, radial force, atraumatic design, and controlled deployment and fixation, may contribute to the safety of the Relay stent-grafts for the treatment of thoracic aortic dissections, including acute and chronic type B dissections.

Both epsilon-toxin and beta-toxin are important for the lethal properties of Clostridium perfringens type B isolates in the mouse intravenous injection model.

PubMed

Fernandez-Miyakawa, Mariano E; Fisher, Derek J; Poon, Rachael; Sayeed, Sameera; Adams, Vicki; Rood, Julian I; McClane, Bruce A; Uzal, Francisco A

2007-03-01

Clostridium perfringens is capable of producing up to 15 toxins, including alpha-toxin (CPA), beta-toxin (CPB), epsilon-toxin (ETX), enterotoxin, beta2-toxin (CPB2), and perfringolysin O. Type B isolates, which must produce CPA, CPB, and ETX, are associated with animal illnesses characterized by sudden death or acute neurological signs, with or without intestinal damage. Type B pathogenesis in ruminants is poorly understood, with some animals showing lesions and clinical signs similar to those caused by either type C or type D infections. It is unknown whether host or environmental conditions are dominant for determining the outcome of type B disease or if disease outcomes are determined by variable characteristics of type B isolates. To help clarify this issue, 19 type B isolates were evaluated for toxin production during late-log-phase growth via quantitative Western blotting and by biological activity assays. Most type B isolates produced CPB levels similar to those produced by type C isolates in vitro and have the potential to produce genotype C-like disease. The lethality of type B isolate supernatants administered intravenously to mice was evaluated with or without prior trypsin treatment, and monoclonal antibody neutralization studies also were performed. Correlation analyses comparing toxin levels in type B supernatants versus lethality and neutralization studies both found that the main contributor to lethality without pretreatment with trypsin was CPB, whereas neutralization studies indicated that CPB and ETX were both important after trypsin pretreatment. At least part of the CPB produced by type B isolates remained active after trypsin treatment. However, the overall lethalities of most supernatants were lower after trypsin pretreatment. Also, there was a significant association between ETX, CPB2, and CPA production in vitro among type B isolates. However, our results suggest that both CPB and ETX are likely the most important contributors to the pathogenesis of C. perfringens type B infections in domestic animals.

Radiologic evaluation of vasculobiliary anatomy in the umbilical fissure.

PubMed

Ji, Gu-Wei; Zhu, Fei-Peng; Wang, Ke; Xia, Yong-Xiang; Jiao, Chen-Yu; Shao, Zi-Cheng; Li, Xiang-Cheng

2017-06-15

Preoperative evaluation of vasculobiliary anatomy in the umbilical fissure (U-point) is pivotal for perihilar cholangiocarcinoma (PCCA) applied to right-sided hepatectomy. The purpose of our study was to review the vasculobiliary anatomy in the U-point using three-dimensional (3D) reconstruction technique, to investigate the diagnostic ability of 2D scans to evaluate anatomic variations, and to discuss its surgical implications. A retrospective study of 159 patients with Bismuth type I, II, and IIIa PCCA, who received surgery at our institution from November 2012 to September 2016, was conducted. Anatomic structures were assessed using multidetector computed tomography (MDCT) by one hepatobiliary surgeon, whereas 3D images were reconstructed by an independent radiologist. Normal confluence pattern of left biliary system was defined as the left medial segmental bile duct (B4) joining the common trunk of segment II (B2) and segment III (B3) ducts, whereas aberrant confluence patterns were classified into 3 types: type I, triple confluence of B2, B3, and B4; type II, B2 draining into the common trunk of B3 and B4; type III, other patterns. Surgical anatomy of B4 was classified into the central, peripheral, and combined type according to its relation to the hepatic confluence. The lengths from the bile duct branch of Spiegel's lobe (B1l) to the orifice of B4 and the junction of B2 and B3 were measured on 3D images. The anatomy of left hepatic artery (LHA) was classified according to different origins and the spatial relationship related to the U-point. 3D reconstruction revealed that normal confluence pattern of left biliary system was observed in 71.1% (113/159) of all patients, and variant patterns were type I in 11.9% (19/159), type II in 12.6% (20/159), and type III in 4.4% (7/159). The length from B1l to the junction of B2 and B3 was 12.1 ± 3.1 mm in type I variation, which was significantly shorter than that in normal configuration (30.0 ± 6.8 mm, P < 0.001) but significantly longer than that in type II variation (9.6 ± 3.4 mm, P = 0.019). Surgical anatomy of B4: the peripheral type was most commonly seen (74.2%, 118/159), followed by central type (15.7%, 25/159) and combined type (10.1%, 16/159). The distance between the B1l and B4 was 8.4 ± 2.4 mm in central and combined type, which was significantly shorter than that in peripheral type (14.5 ± 4.1 mm, P < 0.001). A replaced or accessory LHA from the left gastric artery was present in 6 (3.8%) and 9 (5.7%) patients, respectively. LHA running along the left caudal position of U-point was present in 143 cases (89.9%), along the right cranial position of U-point in nine cases (5.7 %), and combined position in seven cases (4.4%). Interobserver agreement of two imaging modalities was almost perfect in biliary confluence pattern (kappa = 0.90; 95% confidence interval: 0.79-1.00), substantial in surgical anatomy of B4 (kappa = 0.74; 95% confidence interval: 0.62-0.86), and perfect in LHA (kappa = 1.00). Thoroughly understanding the imaging characters of surgical anatomy in the U-point may be benefit for preoperative evaluation of PCCA by successive review of 2D images alone, whereas 3D reconstruction technique allows detailed hepatic anatomy and individualized surgical planning for advanced cases. Copyright © 2017 Elsevier Inc. All rights reserved.

Evaluation of a potential transporter-mediated drug interaction between rosuvastatin and pradigastat, a novel DGAT-1 inhibitor.

PubMed

Kulmatycki, Kenneth; Hanna, Imad; Meyers, Dan; Salunke, Atish; Movva, Aishwarya; Majumdar, Tapan; Natrillo, Adrienne; Vapurcuyan, Arpine; Rebello, Sam; Sunkara, Gangadhar; Chen, Jin

2015-05-01

An in vitro drugdrug interaction (DDI) study was performed to assess the potential for pradigastat to inhibit breast cancer resistance protein (BCRP), organic anion-transporting polypeptide (OATP), and organic anion transporter 3 (OAT3) transport activities. To understand the relevance of these in vitro findings, a clinical pharmacokinetic DDI study using rosuvastatin as a BCRP, OATP, and OAT3 probe substrate was conducted. The study used cell lines that stably expressed or over-expressed the respective transporters. The clinical study was an open-label, single sequence study where subjects (n = 36) received pradigastat (100 mg once daily x 3 days thereafter 40 mg once daily) and rosuvastatin (10 mg once daily), alone and in combination. Pradigastat inhibited BCRP-mediated efflux activity in a dose-dependent fashion in a BCRP over-expressing human ovarian cancer cell line with an IC(50) value of 5 μM. Similarly, pradigastat inhibited OATP1B1, OATP1B3 (estradiol 17β glucuronide transport), and OAT3 (estrone 3 sulfate transport) activity in a concentrationdependent manner with estimated IC(50) values of 1.66 ± 0.95 μM, 3.34 ± 0.64 μM, and 0.973 ± 0.11 μM, respectively. In the presence of steady state pradigastat concentrations, AUC(τ, ss) of rosuvastatin was unchanged and its Cmax,ss decreased by 14% (5.30 and 4.61 ng/mL when administered alone and coadministered with pradigastat, respectively). Pradigastat AUC(τ, ss) and C(max, ss) were unchanged when coadministered with rosuvastatin at steady state. Both rosuvastatin and pradigastat were well tolerated. These data indicate no clinically relevant pharmacokinetic interaction between pradigastat and rosuvastatin.

Genetic Characterization and Comparison of Clostridium botulinum Isolates from Botulism Cases in Japan between 2006 and 2011

PubMed Central

Sekizuka, Tsuyoshi; Yamamoto, Akihiko; Iwaki, Masaaki; Komiya, Takako; Hatakeyama, Takashi; Nakajima, Hiroshi; Takahashi, Motohide; Kuroda, Makoto; Shibayama, Keigo

2014-01-01

Genetic characterization was performed for 10 group I Clostridium botulinum strains isolated from botulism cases in Japan between 2006 and 2011. Of these, 1 was type A, 2 were type B, and 7 were type A(B) {carrying a silent bont/B [bont/(B)] gene} serotype strains, based on botulinum neurotoxin (BoNT) production. The type A strain harbored the subtype A1 BoNT gene (bont/A1), which is associated with the ha gene cluster. The type B strains carried bont/B5 or bont/B6 subtype genes. The type A(B) strains carried bont/A1 identical to that of type A(B) strain NCTC2916. However, bont/(B) genes in these strains showed single-nucleotide polymorphisms (SNPs) among strains. SNPs at 2 nucleotide positions of bont/(B) enabled classification of the type A(B) strains into 3 groups. Pulsed-field gel electrophoresis (PFGE) and multiple-locus variable-number tandem-repeat analysis (MLVA) also provided consistent separation results. In addition, the type A(B) strains were separated into 2 lineages based on their plasmid profiles. One lineage carried a small plasmid (5.9 kb), and another harbored 21-kb plasmids. To obtain more detailed genetic information about the 10 strains, we sequenced their genomes and compared them with 13 group I C. botulinum genomes in a database using whole-genome SNP analysis. This analysis provided high-resolution strain discrimination and enabled us to generate a refined phylogenetic tree that provides effective traceability of botulism cases, as well as bioterrorism materials. In the phylogenetic tree, the subtype B6 strains, Okayama2011 and Osaka05, were distantly separated from the other strains, indicating genomic divergence of subtype B6 strains among group I strains. PMID:25192986

Half-metallic ferromagnetism in {Ti}2 {IrZ} (Z = B, Al, Ga, and In) Heusler alloys: A density functional study

NASA Astrophysics Data System (ADS)

Sadeghi, K. H.; Ahmadian, F.

2018-02-01

The first-principle density functional theory (DFT) calculations were employed to investigate the electronic structures, magnetic properties and half-metallicity of {Ti}2 {IrZ} (Z = B, Al, Ga, and In) Heusler alloys with {AlCu}2 {Mn}- and {CuHg}2 {Ti}-type structures within local density approximation and generalised gradient approximation for the exchange correlation potential. It was found that {CuHg}2 {Ti}-type structure in ferromagnetic state was energetically more favourable than {AlCu}2 {Mn}-type structure in all compounds except {Ti}2 {IrB} which was stable in {AlCu}2 {Mn}-type structure in non-magnetic state. {Ti}2 {IrZ} (Z = B, Al, Ga, and In) alloys in {CuHg}2 {Ti}-type structure were half-metallic ferromagnets at their equilibrium lattice constants. Half-metallic band gaps were respectively equal to 0.87, 0.79, 0.75, and 0.73 eV for {Ti}2 {IrB}, {Ti}2 {IrAl}, {Ti}2 {IrGa}, and {Ti}2 {IrIn}. The origin of half-metallicity was discussed for {Ti}2 {IrGa} using the energy band structure. The total magnetic moments of {Ti}2 {IrZ} (Z = B, Al, Ga, and In) compounds in {CuHg}2 {Ti}-type structure were obtained as 2μ B per formula unit, which were in agreement with Slater-Pauling rule (M_{tot} =Z_{tot}-18). All the four compounds were half-metals in a wide range of lattice constants indicating that they may be suitable and promising materials for future spintronic applications.

First molecular characterization of canine parvovirus strains in Sardinia, Italy.

PubMed

Dei Giudici, S; Cubeddu, T; Giagu, A; Sanna, G; Rocca, S; Oggiano, A

2017-11-01

Canine parvovirus type 2 (CPV-2) is responsible of acute hemorrhagic gastroenteritis in young dogs. CPV-2 emerged in 1978 in the USA, but new antigenic types, CPV-2a, 2b and 2c, have completely replaced the original type. In this study, we analyzed 81 animals collected in Sardinia, Italy. The VP2 sequence analysis of 27 positive samples showed that all antigenic CPV-2 types are circulating. CPV-2b seems to be the most widespread variant, followed by CPV-2a. Furthermore, 12 CPV-2b strains displayed further amino acid substitutions and formed a separate cluster in a phylogenetic tree, indicating regional genetic variation.

Biomechanical study of four kinds of percutaneous screw fixation in two types of unilateral sacroiliac joint dislocation: a finite element analysis.

PubMed

Zhang, Lihai; Peng, Ye; Du, Chengfei; Tang, Peifu

2014-12-01

To compare the biomechanical stability of four different kinds of percutaneous screw fixation in two types of unilateral sacroiliac joint dislocation. Finite element models of unstable Tile type B and type C pelvic ring injuries were created in this study. Modelling was based on fixation with a single S1 screw (S1-1), single S2 screw (S2-1), two S1 screws (S1-2) and a combination of a single S1 and a single S2 screw (S1–S2). The biomechanical test of two types of pelvic instability (rotational or vertical) with four types of percutaneous fixation were compared. Displacement, flexion and lateral bend (in bilateral stance) were recorded and analyzed. Maximal inferior translation (displacement) was found in the S2-1 group in type B and C dislocations which were 1.58 mm and 1.90 mm, respectively. Maximal flexion was found in the S2-1 group in type B and C dislocations which were 1.55° and 1.95°, respectively. The results show that the flexion from most significant angulation to least is S2-1, S1-1, S1-2, and S1–S2 in type B and C dislocations. All the fixations have minimal lateral bend. Our findings suggest single screw S1 fixation should be adequate fixation for a type B dislocation. For type C dislocations, one might consider a two screw construct (S1–S2) to give added biomechanical stability if clinically indicated.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Meng; Wang, Yachun; Yao, Jinlei

MnB{sub 4} was newly synthesized to crystallize in a monoclinic P2{sub 1}/c structure, different from previous experimental and theoretical reports. Here, based on first-principles calculations, we perform a comparative study of geometric and energetic features, mechanical behaviors, electronic property and chemical bonding of the experimentally identified monoclinic MnB{sub 4}, as well as orthorhombic CrB{sub 4} and FeB{sub 4}. The results demonstrate that the presence of distorted rhomboidal-B{sub 4} units and one-dimensional Mn chains in the monoclinic MnB{sub 4} breaks the structural symmetry and lowers the total energy in comparison to the orthorhombic phase. The opening of band gap in MnB{submore » 4} is induced by Peierls-paired Mn atoms, differing from the metallic behaviors of recently studied tetraborides. Specifically, the preservations of covalent bonding in distorted boron-rhomboids in MnB{sub 4} explain the relatively higher incompressibility and hardness. - Graphical abstract: P2{sub 1}/c-type structure for MnB{sub 4} characterizes rhomboid-B{sub 4} units and alternately short and long Mn–Mn chains. - Highlights: • The novel P2{sub 1}/c-type MnB{sub 4} compound is studied by first-principles calculations. • P2{sub 1}/c-type MnB{sub 4} has lower total energy and relatively higher stability. • An energy gap opening is found for P2{sub 1}/c-type MnB{sub 4} induced by Mn atom pairs. • P2{sub 1}/c-type MnB{sub 4} exhibits excellent mechanical properties. • The mechanical properties of TcB{sub 4} and ReB{sub 4} in P2{sub 1}/c structure are also studied.« less

Leptospira interrogans serovars Bratislava and Muenchen animal infections: Implications for epidemiology and control.

PubMed

Arent, Z; Frizzell, C; Gilmore, C; Allen, A; Ellis, W A

2016-07-15

Strains of Leptospira interrogans belonging to two very closely related serovars - Bratislava and Muenchen - have been associated with disease in domestic animals, in particular pigs, but also in horses and dogs. Similar strains have also been recovered from various wildlife species. Their epidemiology is poorly understood. Two hundred and forty seven such isolates, from UK domestic animal and wildlife species, were examined by restriction endonuclease analysis in an attempt to elucidate their epidemiology. A representative sub-sample of 65 of these isolates was further examined by multiple-locus variable-number tandem repeat analysis and 22 by secY sequencing. Ten restriction pattern types were identified. The majority of isolates fell into one of three restriction endonuclease analysis pattern types designated B2a, B2b and M2a. B2a was ubiquitous and was isolated from 10 species and represented the majority of the horse and all dog isolates. B2b was very different, being isolated only from pigs, indicating that this type was maintained by pigs. The pattern M2a was reported for the majority of isolates from pigs but also was common in small rodents isolates. Five restriction pattern types were found only in wildlife suggesting that they are unlikely to pose a disease threat to domestic animals. Multiple-locus variable-number tandem repeat analysis identified six clusters. The REA types B2a and B2b were all found in one MLVA cluster while the majority of the M2a strains examined occurred in another cluster. The secY sequencing detected only one sequence type, clustered with other serovars of Leptospira interrogans. Copyright © 2016 Elsevier B.V. All rights reserved.

[Insulin pump in type 2 diabetes: B-cell focused treatment].

PubMed

Picková, Klára; Rušavý, Zdeněk

Type 2 diabetes is a disorder characterized by insulin resistance and progressive deterioration of B-cell insulin secretion. B-cell protective strategies for lowering glucolipotoxicity by rapid achievement of normoglycemia using exogenous insulin improve their function and prolong diabetes remission. Insulin pump is an effective treatment method in newly diagnosed diabetes, where even short-term pump therapy is B-cell protective. Combination therapy with insulin pump and antidiabetics targeting the incretin system acts in synergy to protect the B-cell. While the positive effect of insulin pump is apparent even a year after stopping the therapy, the effect of incretins lasts only while on the medication. Short-term insulin treatment, especially delivered by insulin pump, is an effective method of B-cell protection in recent type 2 diabetes.Key words: B-cell function - diabetes mellitus - insulin pump - insulin resistance - type 2 diabetes.

Islet-specific monoamine oxidase A and B expression depends on MafA transcriptional activity and is compromised in type 2 diabetes.

PubMed

Ganic, Elvira; Johansson, Jenny K; Bennet, Hedvig; Fex, Malin; Artner, Isabella

2015-12-25

Lack or dysfunction of insulin producing β cells results in the development of type 1 and type 2 diabetes mellitus, respectively. Insulin secretion is controlled by metabolic stimuli (glucose, fatty acids), but also by monoamine neurotransmitters, like dopamine, serotonin, and norepinephrine. Intracellular monoamine levels are controlled by monoamine oxidases (Mao) A and B. Here we show that MaoA and MaoB are expressed in mouse islet β cells and that inhibition of Mao activity reduces insulin secretion in response to metabolic stimuli. Moreover, analysis of MaoA and MaoB protein expression in mouse and human type 2 diabetic islets shows a significant reduction of MaoB in type 2 diabetic β cells suggesting that loss of Mao contributes to β cell dysfunction. MaoB expression was also reduced in β cells of MafA-deficient mice, a mouse model for β cell dysfunction, and biochemical studies showed that MafA directly binds to and activates MaoA and MaoB transcriptional control sequences. Taken together, our results show that MaoA and MaoB expression in pancreatic islets is required for physiological insulin secretion and lost in type 2 diabetic mouse and human β cells. These findings demonstrate that regulation of monoamine levels by Mao activity in β cells is pivotal for physiological insulin secretion and that loss of MaoB expression may contribute to the β cell dysfunction in type 2 diabetes. Copyright © 2015 Elsevier Inc. All rights reserved.

39 CFR 3010.13 - Proceedings for Type 1-A and Type 1-B rate adjustment filings.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 39 Postal Service 1 2010-07-01 2010-07-01 false Proceedings for Type 1-A and Type 1-B rate... (Type 1-A and 1-B Rate Adjustments) § 3010.13 Proceedings for Type 1-A and Type 1-B rate adjustment... include: (1) The general nature of the proceeding; (2) A reference to legal authority to which the...

Increased ability of LDL from normolipidemic type 2 diabetic women to generate peroxides.

PubMed

Guerci, B; Antebi, H; Meyer, L; Durlach, V; Ziegler, O; Nicolas, J P; Alcindor, L G; Drouin, P

1999-09-01

We assessed the ability of LDL from 30 type 1 diabetic patients (18 men, 12 women), 65 type 2 diabetic patients (35 men, 30 women), and 35 controls (19 men, 16 women) to generate peroxides. The men and women in the diabetic groups were studied separately and matched for age, body mass index, duration of diabetes, glycohemoglobin, and conventional lipid characteristics according to the presence or absence of hyperlipidemia. The ability of LDL to form peroxides was assessed by measuring the thiobarbituric acid-reactive substances corrected for LDL-cholesterol [ratio of malondialdehyde (MDA) to LDL-cholesterol]. LDL particle size was expressed as the ratio of LDL-cholesterol to apolipoprotein B (LDL-cholesterol/apoB). The MDA/LDL-cholesterol ratio was higher in type 1 and type 2 diabetic patients with hyperlipidemia than in controls. The MDA/LDL-cholesterol ratio was also higher in type 2 normolipidemic women than in controls (P <0.01). The LDL-cholesterol/apoB ratio was lower in type 2 diabetic women than in type 2 diabetic men (P <0.05). The MDA/LDL-cholesterol ratio was negatively correlated with the LDL-cholesterol/apoB ratio (r = -0.78, P <0.001) in hyperlipidemic type 1 (not type 2) diabetic patients. In normolipidemic type 2 diabetic patients, the MDA/LDL-cholesterol ratio was also negatively correlated with the LDL-cholesterol/apoB ratio (r = -0.75, P <0.001) because of the highly significant negative correlation in type 2 diabetic women (r = -0.89, P <0.01). LDL from well-controlled type 2 diabetic women is smaller and more prone to form peroxides. This could explain why diabetic women are at greater risk of cardiovascular disease.

Predicting the Occurrence of Oxygenation Impairment in Patients with Type-B Acute Aortic Dissection

PubMed Central

Tomita, Kazunori; Hata, Noritake; Kobayashi, Nobuaki; Shinada, Takuro; Shirakabe, Akihiro

2014-01-01

Complicated respiratory failure requiring mechanical ventilation in patients with type-B acute aortic dissection (AAD) has been previously reported, and inflammatory reactions have been found to be associated with the occurrence of oxygenation impairment (OI). However, the possibility of predicting the occurrence of OI in patients with type-B AAD has not yet been evaluated. This study was performed to investigate the possibility of predicting the occurrence of OI in type-B AAD. In this study, 79 type-B AAD patients were enrolled to investigate the possibility of predicting the occurrence of OI. OI was defined as Po 2/Fio 2 ≤ 200. Patient characteristics, type of AAD, vital signs on admission, and the presence of inflammatory reactions obtained on admission day were evaluated. OI occurred in 39 patients (49%) on hospital day 2.5 ± 1.4 on average. Younger age, male gender, nonslender frame (body mass index ≥ 22 kg/m2), a relatively high maximum body temperature on the admission day (≥ 36.5°C), DeBakey IIIb type, patent false lumen, and lower Po 2/Fio 2 on admission were found to be associated with the occurrence of OI. Multivariate analysis revealed that nonslender frame, relatively high body temperature on the admission day, and lower Po 2/Fio 2 on admission were reliable for predicting the occurrence of oxygen impairment. The occurrence of OI in type-B AAD can be predicted in the clinical setting. PMID:24627618

Gaucher disease types 1, 2, and 3: differential mutations of the acid beta-glucosidase active site identified with conduritol B epoxide derivatives and sphingosine.

PubMed Central

Grabowski, G A; Dinur, T; Osiecki, K M; Kruse, J R; Legler, G; Gatt, S

1985-01-01

To elucidate the genetic heterogeneity in Gaucher disease, the residual beta-glucosidase in cultured fibroblasts from affected patients with each of the major phenotypes was investigated in vitro and/or in viable cells by inhibitor studies using the covalent catalytic site inhibitors, conduritol B epoxide or its bromo derivative, and the reversible cationic inhibitor, sphingosine. These studies delineated three distinct groups (designated A, B, and C) of residual activities with characteristic responses to these inhibitors. Group A residual enzymes had normal I50 values (i.e., the concentration of inhibitor that results in 50% inhibition) for the inhibitors and normal or nearly normal t1/2 values for conduritol B epoxide. All neuronopathic (types 2 and 3) and most non-Jewish nonneuronopathic (type 1) patients had group A residual activities and, thus, could not be distinguished by these inhibitor studies. Group B residual enzymes had about four- to fivefold increased I50 values for the inhibitors and similarly increased t1/2 values for conduritol B epoxide. All Ashkenazi Jewish type 1 and only two non-Jewish type 1 patients had group B residual activities. The differences in I50 values between groups A and B also were confirmed by determining the uninhibited enzyme activity after culturing the cells in the presence of bromo-conduritol B epoxide. Group C residual activity had intermediate I50 values for the inhibitors and represented a single Afrikaner type 1 patient: this patient was a genetic compound for the group A (type 2) and group B (type 1) mutations. These inhibition studies indicated that: Gaucher disease type 1 is biochemically heterogeneous, neuronopathic and non-Jewish nonneuronopathic phenotypes cannot be reliably distinguished by these inhibitor studies, and the Ashkenazi Jewish form of Gaucher disease type 1 results from a unique mutation in a specific active site domain of acid beta-glucosidase that leads to a defective enzyme with a decreased Vmax. PMID:4003396

Polymorphism of the bivalent metal vanadates MeV 2O 6 ( Me = Mg, Ca, Mn, Co, Ni, Cu, Zn, Cd)

NASA Astrophysics Data System (ADS)

Mocała, Krzysztof; Ziółkowski, Jacek

1987-08-01

Based on the literature data, our former findings and additional DTA and high-temperature X-ray studies performed for CdV 2O 6, MgV 2O 6, and MnV 2O 6, a consistent scheme of the phase transformations of the MeV 2O 6 ( Me = Mg, Ca, Mn, Co, Ni, Cu, Zn, Cd) metavanadates is constructed at normal pressure between room temperature and melting points. Three types of structures exist for the considered compounds: brannerite type (B), pseudobrannerite type (P), and NiV 2O 6 type (N). The following phase transformations have been observed: Me = Mg, B → P at 535°C; Me = Mn, B → P at 540°C; Me = Co, N → B at 660°C; Me = Cu, B (with triclinic distortion) → B at 625°C (secondary order); and Me = Cd, B → P at 170°. CaV 2O 6P, NiV 2O 6N, and ZnV 2O 6B exist in unique form in the entire temperature range. P-form seems to be favored by Me of larger ionic radii. N-form seems to appear at a peculiar d-shell structure and small Me size. Preliminary explanation of the dependence of the structure type on Me size is offered. New X-ray data are given for CdV 2O 6B, CdV 2O 6P, MgV 2O 6B, MgV 2O 6P, and MnV 2O 6P.

Characterisation of the LH2 spectral variants produced by the photosynthetic purple sulphur bacterium Allochromatium vinosum.

PubMed

Carey, Anne-Marie; Hacking, Kirsty; Picken, Nichola; Honkanen, Suvi; Kelly, Sharon; Niedzwiedzki, Dariusz M; Blankenship, Robert E; Shimizu, Yuuki; Wang-Otomo, Zheng-Yu; Cogdell, Richard J

2014-11-01

This study systematically investigated the different types of LH2 produced by Allochromatium (Alc.) vinosum, a photosynthetic purple sulphur bacterium, in response to variations in growth conditions. Three different spectral forms of LH2 were isolated and purified, the B800-820, B800-840 and B800-850 LH2 types, all of which exhibit an unusual split 800 peak in their low temperature absorption spectra. However, it is likely that more forms are also present. Relatively more B800-820 and B800-840 are produced under low light conditions, while relatively more B800-850 is produced under high light conditions. Polypeptide compositions of the three different LH2 types were determined by a combination of HPLC and TOF/MS. The B800-820, B800-840 and B800-850 LH2 types all have a heterogeneous polypeptide composition, containing multiple types of both α and β polypeptides, and differ in their precise polypeptide composition. They all have a mixed carotenoid composition, containing carotenoids of the spirilloxanthin series. In all cases the most abundant carotenoid is rhodopin; however, there is a shift towards carotenoids with a higher conjugation number in LH2 complexes produced under low light conditions. CD spectroscopy, together with the polypeptide analysis, demonstrates that these Alc. vinosum LH2 complexes are more closely related to the LH2 complex from Phs. molischianum than they are to the LH2 complexes from Rps. acidophila. Copyright © 2014. Published by Elsevier B.V.

Novel Nine-Exon AR Transcripts (Exon 1/Exon 1b/Exons 2-8) in Normal and Cancerous Breast and Prostate Cells.

PubMed

Hu, Dong Gui; McKinnon, Ross A; Hulin, Julie-Ann; Mackenzie, Peter I; Meech, Robyn

2016-12-27

Nearly 20 different transcripts of the human androgen receptor (AR) are reported with two currently listed as Refseq isoforms in the NCBI database. Isoform 1 encodes wild-type AR (type 1 AR) and isoform 2 encodes the variant AR45 (type 2 AR). Both variants contain eight exons: they share common exons 2-8 but differ in exon 1 with the canonical exon 1 in isoform 1 and the variant exon 1b in isoform 2. Splicing of exon 1 or exon 1b is reported to be mutually exclusive. In this study, we identified a novel exon 1b (1b/TAG) that contains an additional TAG trinucleotide upstream of exon 1b. Moreover, we identified AR transcripts in both normal and cancerous breast and prostate cells that contained either exon 1b or 1b/TAG spliced between the canonical exon 1 and exon 2, generating nine-exon AR transcripts that we have named isoforms 3a and 3b. The proteins encoded by these new AR variants could regulate androgen-responsive reporters in breast and prostate cancer cells under androgen-depleted conditions. Analysis of type 3 AR-GFP fusion proteins showed partial nuclear localization in PC3 cells under androgen-depleted conditions, supporting androgen-independent activation of the AR. Type 3 AR proteins inhibited androgen-induced growth of LNCaP cells. Microarray analysis identified a small set of type 3a AR target genes in LNCaP cells, including genes known to modulate growth and proliferation of prostate cancer ( PCGEM1 , PEG3 , EPHA3 , and EFNB2 ) or other types of human cancers ( TOX3 , ST8SIA4 , and SLITRK3 ), and genes that are diagnostic/prognostic biomarkers of prostate cancer ( GRINA3 , and BCHE ).

Effects of light and the regulatory B-subunit composition of protein phosphatase 2A on the susceptibility of Arabidopsis thaliana to aphid (Myzus persicae) infestation

PubMed Central

Rasool, Brwa; Karpinska, Barbara; Konert, Grzegorz; Durian, Guido; Denessiouk, Konstantin; Kangasjärvi, Saijaliisa; Foyer, Christine H.

2014-01-01

The interactions between biotic and abiotic stress signaling pathways are complex and poorly understood but protein kinase/phosphatase cascades are potentially important components. Aphid fecundity and susceptibility to Pseudomonas syringae infection were determined in the low light-grown Arabidopsis thaliana wild type and in mutant lines defective in either the protein phosphatase (PP)2A regulatory subunit B'γ (gamma; pp2a-b'γ) or B'ζ (zeta; pp2a-b'ζ1-1 and pp2a-b'ζ 1-2) and in gamma zeta double mutants (pp2a-b'γζ) lacking both subunits. All the mutants except for pp2a-b'ζ 1-1 had significantly lower leaf areas than the wild type. Susceptibility to P. syringae was similar in all genotypes. In contrast, aphid fecundity was significantly decreased in the pp2a-b'γ mutant relative to the wild type but not in the pp2a-b'γζ double mutant. A high light pre-treatment, which led to a significant increase in rosette growth in all mutant lines but not in the wild type, led to a significant decrease in aphid fecundity in all genotypes. The high light pre-treatment abolished the differences in aphid resistance observed in the pp2a-b'γ mutant relative to the wild type. The light and CO2 response curves for photosynthesis were changed in response to the high light pre-treatment, but the high light effects were similar in all genotypes. These data demonstrate that a pre-exposure to high light and the composition of B-subunits on the trimeric PP2A holoenzymes are important in regulating plant resistance to aphids. The functional specificity for the individual regulatory B-subunits may therefore limit aphid colonization, depending on the prevailing abiotic stress environment. PMID:25191331

Characterization of the recognition specificity of BH2, a monoclonal antibody prepared against the HLA-B27 heavy chain.

PubMed

Yu, Hui-Chun; Huang, Kuang-Yung; Lu, Ming-Chi; Huang, Hsien-Lu; Liu, Wei-Ting; Lee, Wen-Chien; Liu, Su-Qin; Huang, Hsien-Bin; Lai, Ning-Sheng

2015-04-13

BH2, a monoclonal antibody prepared against the denatured human leukocytic antigen-B27 heavy chain (HLA-B27 HC), can immunoprecipitate the misfolded HLA-B27 HC complexed with Bip in the endoplasmic reticulum and recognize the homodimerized HLA-B27 HC that is often observed on the cell membrane of patients suffered from ankylosing spondylitis (AS). However, the recognition specificity of BH2 toward the other molecules of HLA-B type and toward the different types of HLA molecules remained uncharacterized. In this study, we carried out the HLA-typing by using the Luminex Technology to characterize the recognition specificity of BH2 and analyzed the binding domain of HLA-B27 HC by BH2. Our results indicated that BH2 preferably binds to molecules of HLA-B and -C rather than HLA-A and the binding site is located within the α2 domain of HLA-B27 HC.

Evaluation of an heterogeneous group of patients with von Willebrand disease using an assay alternative to ristocetin induced platelet agglutination.

PubMed

Stufano, F; Baronciani, L; Pagliari, M T; Franchi, F; Cozzi, G; Garcia-Oya, I; Bucciarelli, P; Boscarino, M; Peyvandi, F

2015-10-01

Diagnosis of von Willebrand disease (VWD) type 2 usually relies on the discrepancy between the von Willebrand factor (VWF) ristocetin cofactor activity (VWF:RCo) and VWF antigen (VWF:Ag). Type 2B patients can be discriminated from other qualitative VWD variants by using ristocetin-induced platelet agglutination (RIPA) test. The major limitation of RIPA is the requirement of fresh blood sample. In this study, we evaluated the VWF gain-of-function mutant GPIb binding (VWF:GPIbM) and VWF:RCo assays to investigate whether the VWF:GPIbM/VWF:RCo ratio was able to identify the type 2B variant among an heterogeneous VWD population, previously characterized following the ISTH-SSC guidelines. Seventy-six VWD patients and 31 healthy subjects were evaluated by using VWF:Ag, VWF:RCo, and VWF:GPIbM assays. The mean (minimum-maximum values) VWF:GPIbM/VWF:RCo ratio was higher in type 2B patients (2.53, 0.84-6.11) than in healthy controls (1.05, 0.87-1.34), type 1 (0.85, 0.51-1.15), 2A (1.20, 0.36-2.82), and 2M (1.07, 0.91-1.38) (P < 0.0001). Type 2B variants were divided into four groups (A, B, C, and D) according to their different multimeric patterns. The mean value of the VWF:GPIbM/VWF:RCo ratio in the four groups showed an increasing trend from group A (1.08) to D (3.69), proportional to the loss of high molecular weight multimers. Among 32 type 2B patients, previously diagnosed with RIPA, 8 (mainly with a type I New York/Malmö phenotype) were not confirmed using the VWF:GPIbM/VWF:RCo ratio. Whenever the RIPA test is not feasible, the VWF:GPIbM/VWF:RCo ratio might help to identify severe type 2B VWD patients. © 2015 International Society on Thrombosis and Haemostasis.

Strong association of common variants in the CDKN2A/CDKN2B region with type 2 diabetes in French Europids.

PubMed

Duesing, K; Fatemifar, G; Charpentier, G; Marre, M; Tichet, J; Hercberg, S; Balkau, B; Froguel, P; Gibson, F

2008-05-01

Genome-wide association studies (GWASs) recently identified common variants in the CDKN2A/CDKN2B region on chromosome 9p as being strongly associated with type 2 diabetes. Since these association signals were not picked up by the French-Canadian GWAS, we sought to replicate these findings in the French Europid population and to further characterise the susceptibility variants at this novel locus. We genotyped 20 single nucleotide polymorphisms (SNPs) spanning the CDKN2A/CDKN2B locus in our type 2 diabetes case-control cohort. The association between CDKN2A/CDKN2B SNPs and quantitative metabolic traits was also examined in the normoglycaemic participants comprising the control cohort. We report replication of the strong association of rs10811661 with type 2 diabetes found in the GWASs (P= 3.8 X 10(-7); OR 1.43 [95% CI 1.24-1.64]). The other CDKN2A/CDKN2B susceptibility variant, rs564398, did not attain statistical significance (p = 0.053; OR 1.11 [95% CI 1.00-1.24]) in the present study. We also obtained several additional nominal association signals (p < 0.05) at the CDKN2A/CDKN2B locus; however, only the rs3218018 result (p = 0.002) survived Bonferroni correction for multiple testing (adjusted p = 0.04). Our comprehensive association study of common variation spanning the CDKN2A/CDKN2B locus confirms the strong association between the distal susceptibility variant rs10811661 and type 2 diabetes in the French population. Further genetic and functional studies are required to identify the aetiological variants at this locus and determine the cellular and physiological mechanisms by which they act to modulate type 2 diabetes susceptibility.

Diffusion of chains in a periodic potential

NASA Astrophysics Data System (ADS)

Terranova, G. R.; Mártin, H. O.; Aldao, C. M.

2017-09-01

We studied the diffusion of 1D rigid chains in a square wave potential of period T. We considered chains of type A (composed of N particles A) and chains of type A-B (composed of N/2 particles A and N/2 particles B). The square wave potential represents domains, a lamellar structure observed for block copolymers, in which the repulsive δ energy between each A particle (B particle) of the chain and B particles (A particles) of the medium where the chains diffuse. From Monte Carlo simulations and analytical results it is found that the normalized diffusivity D, for N\\ll T , presents a universal behavior as a function of X  =  Nδ for chains of type A and X  =  (Nδ  -  lnT 2) for chains of type A-B, with and exponential decay for large values of X. For fixed values of δ and T, D is a periodic function of N with period T and 2T for chains of type A and type A-B, respectively.

High-Pressure Phase Relations and Crystal Structures of Postspinel Phases in MgV2O4, FeV2O4, and MnCr2O4: Crystal Chemistry of AB2O4 Postspinel Compounds.

PubMed

Ishii, Takayuki; Sakai, Tsubasa; Kojitani, Hiroshi; Mori, Daisuke; Inaguma, Yoshiyuki; Matsushita, Yoshitaka; Yamaura, Kazunari; Akaogi, Masaki

2018-06-04

We have investigated high-pressure, high-temperature phase transitions of spinel (Sp)-type MgV 2 O 4 , FeV 2 O 4 , and MnCr 2 O 4 . At 1200-1800 °C, MgV 2 O 4 Sp decomposes at 4-7 GPa into a phase assemblage of MgO periclase + corundum (Cor)-type V 2 O 3 , and they react at 10-15 GPa to form a phase with a calcium titanite (CT)-type structure. FeV 2 O 4 Sp transforms to CT-type FeV 2 O 4 at 12 GPa via decomposition phases of FeO wüstite + Cor-type V 2 O 3 . MnCr 2 O 4 Sp directly transforms to the calcium ferrite (CF)-structured phase at 10 GPa and 1000-1400 °C. Rietveld refinements of CT-type MgV 2 O 4 and FeV 2 O 4 and CF-type MnCr 2 O 4 confirm that both the CT- and CF-type structures have frameworks formed by double chains of edge-shared B 3+ O 6 octahedra (B 3+ = V 3+ and Cr 3+ ) running parallel to one of orthorhombic cell axes. A relatively large A 2+ cation (A 2+ = Mg 2+ , Fe 2+ , and Mn 2+ ) occupies a tunnel-shaped space formed by corner-sharing of four double chains. Effective coordination numbers calculated from eight neighboring oxygen-A 2+ cation distances of CT-type MgV 2 O 4 and FeV 2 O 4 and CF-type MnCr 2 O 4 are 5.50, 5.16, and 7.52, respectively. This implies that the CT- and CF-type structures practically have trigonal prism (six-coordinated) and bicapped trigonal prism (eight-coordinated) sites for the A 2+ cations, respectively. A relationship between cation sizes of VIII A 2+ and VI B 3+ and crystal structures (CF- and CT-types) of A 2+ B 2 3+ O 4 is discussed using the above new data and available previous data of the postspinel phases. We found that CF-type A 2+ B 2 3+ O 4 crystallize in wide ionic radius ranges of 0.9-1.4 Å for VIII A 2+ and 0.55-1.1 Å for VI B 3+ , whereas CT-type phases crystallize in very narrow ionic radius ranges of ∼0.9 Å for VIII A 2+ and 0.6-0.65 Å for VI B 3+ . This would be attributed to the fact that the tunnel space of CT-type structure is geometrically less flexible due to the smaller coordination number for A 2+ cation than that of CF-type.

Deletion of the distal COOH-terminus of the A2B adenosine receptor switches internalization to an arrestin- and clathrin-independent pathway and inhibits recycling.

PubMed

Mundell, S J; Matharu, A-L; Nisar, S; Palmer, T M; Benovic, J L; Kelly, E

2010-02-01

We have investigated the effect of deletions of a postsynaptic density, disc large and zo-1 protein (PDZ) motif at the end of the COOH-terminus of the rat A(2B) adenosine receptor on intracellular trafficking following long-term exposure to the agonist 5'-(N-ethylcarboxamido)-adenosine. The trafficking of the wild type A(2B) adenosine receptor and deletion mutants expressed in Chinese hamster ovary cells was studied using an enzyme-linked immunosorbent assay in combination with immunofluorescence microscopy. The wild type A(2B) adenosine receptor and deletion mutants were all extensively internalized following prolonged treatment with NECA. The intracellular compartment through which the Gln(325)-stop receptor mutant, which lacks the Type II PDZ motif found in the wild type receptor initially trafficked was not the same as the wild type receptor. Expression of dominant negative mutants of arrestin-2, dynamin or Eps-15 inhibited internalization of wild type and Leu(330)-stop receptors, whereas only dominant negative mutant dynamin inhibited agonist-induced internalization of Gln(325)-stop, Ser(326)-stop and Phe(328)-stop receptors. Following internalization, the wild type A(2B) adenosine receptor recycled rapidly to the cell surface, whereas the Gln(325)-stop receptor did not recycle. Deletion of the COOH-terminus of the A(2B) adenosine receptor beyond Leu(330) switches internalization from an arrestin- and clathrin-dependent pathway to one that is dynamin dependent but arrestin and clathrin independent. The presence of a Type II PDZ motif appears to be essential for arrestin- and clathrin-dependent internalization, as well as recycling of the A(2B) adenosine receptor following prolonged agonist addition.

Strain-specific reverse transcriptase PCR assay: means to distinguish candidate vaccine from wild-type strains of respiratory syncytial virus.

PubMed Central

Zheng, H; Peret, T C; Randolph, V B; Crowley, J C; Anderson, L J

1996-01-01

Candidate live-virus vaccines for respiratory syncytial virus are being developed and are beginning to be evaluated in clinical trials. To distinguish candidate vaccine strains from wild-type strains isolated during these trials, we developed PCR assays specific to two sets of candidate vaccine strains. The two sets were a group A strain (3A), its three attenuated, temperature-sensitive variant strains, a group B strain (2B), and its four attenuated, temperature-sensitive variant strains. The PCR assays were evaluated by testing 18 group A wild-type strains, the 3A strains, 9 group B wild-type strains, and the 2B strains. PCR specific to group A wild-type strains amplified only group A wild-type strains, and 3A-specific PCR amplified only 3A strains. PCR specific to group B wild-type strains amplified all group A and group B strains but gave a 688-bp product for group B wild-type strains, a 279-bp product for 2B strains, a 547-bp product for all group A strains, and an additional 688-bp product for some group A strains, including 3A strains. These types of PCR assays can, in conjunction with other methods, be used to efficiently distinguish candidate vaccine strains from other respiratory syncytial virus strains. PMID:8789010

In search of the elusive IrB{sub 2}: Can mechanochemistry help?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xie, Zhilin; Blair, Richard G.; Department of Physics, University of Central Florida, Orlando, FL 32816

The previously unknown hexagonal ReB{sub 2}-type IrB{sub 2} diboride and orthorhombic IrB monoboride phases were produced by mechanochemical syntheses. High energy ball milling of elemental Ir and B powder for 30 h, followed by annealing of the powder at 1050 °C for 48 h, resulted in the formation of the desired phases. Both traditional laboratory and high resolution synchrotron X-ray diffraction (XRD) analyses were used for phase identification of the synthesized powder. In addition to XRD, scanning electron microscopy and transmission electron microscopy were employed to further characterize the microstructure of the phases produced. - Graphical abstract: ReB{sub 2}-type IrB{submore » 2} and a new IrB have been successfully synthesized for the first time using mechanochemical method. Crystal structures of IrB{sub 2} and IrB were studied by synchrotron X-ray diffraction. Microstructures of the new phases were characterized by SEM and TEM. - Highlights: • ReB{sub 2}-type IrB{sub 2} and a new IrB have been synthesized by mechanochemical method. • Crystal structures of IrB{sub 2} and IrB were studied by synchrotron XRD. • Microstructures of the new phases were characterized by SEM and TEM.« less

TEM verification of the <111>-type 4-arm multi-junction in [001]-Mo single crystals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hsiung, L

2005-03-14

To investigate and verify the formation of <111>-type 4-arm multi-junction by the dislocation reaction of 1/2[111] [b1] + 1/2[{bar 1}1{bar 1}] [b2] + 1/2[{bar 1}{bar 1}1] [b3] = 1/2[{bar 1}11] [b4], which has recently been discovered through computer simulations conducted by Vasily Bulatov and his colleagues.

Survey Study and Records Review of Treatment Outcomes in Freeman-Sheldon Syndrome

ClinicalTrials.gov

2018-03-30

Freeman-Sheldon Syndrome; Arthrogryposis Distal Type 2A; Whistling Face Syndrome; Craniocarpotarsal Dysplasia; Craniocarpotarsal Dystrophy; Freeman-Sheldon Syndrome Variant; Sheldon-Hall Syndrome; Arthrogryposis Distal Type 2B; Gordon Syndrome; Arthrogryposis Distal Type 3; Arthrogryposis Distal Type 1; Arthrogryposis, Distal, Type 1A; Arthrogryposis Distal Type 1B; Arthrogryposis, Distal; Craniofacial Abnormalities; Arthrogryposis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morozkin, A.V., E-mail: morozkin@tech.chem.msu.ru; Isnard, O.; Université Grenoble Alpes, Inst. Néel, F-38042 Grenoble

The crystal structure of new Mo{sub 2}NiB{sub 2}-type (Gd, Tb, Dy){sub 2}Ni{sub 2.35}Si{sub 0.65} (Immm, No. 71, oI10) and La{sub 2}Ni{sub 3}-type (Dy, Ho){sub 2}Ni{sub 2.5}Si{sub 0.5} (Cmce No. 64, oC20) compounds has been established using powder X-ray diffraction studies. Magnetization measurements show that the Mo{sub 2}NiB{sub 2}-type Gd{sub 2}Ni{sub 2.35}Si{sub 0.65} undergoes a ferromagnetic transition at ~66 K, whereas isostructural Tb{sub 2}Ni{sub 2.35}Si{sub 0.65} shows an antiferromagnetic transition at ~52 K and a field-induced metamagnetic transition at low temperatures. Neutron diffraction study shows that, in zero applied field, Tb{sub 2}Ni{sub 2.35}Si{sub 0.65} exhibits c-axis antiferromagnetic order with propagation vectormore » K=[1/2, 0, 1/2] below its magnetic ordering temperature and Tb magnetic moment reaches a value of 8.32(5) μ{sub B} at 2 K. The La{sub 2}Ni{sub 3}-type Dy{sub 2}Ni{sub 2.5}Si{sub 0.5} exhibits ferromagnetic like transition at ~42 K with coexisting antiferromagnetic interactions and field induced metamagnetic transition below ~17 K. The magnetocaloric effect of Gd{sub 2}Ni{sub 2.35}Si{sub 0.65}, Tb{sub 2}Ni{sub 2.35}Si{sub 0.65} and Dy{sub 2}Ni{sub 2.5}Si{sub 0.5} is calculated in terms of isothermal magnetic entropy change and it reaches a maximum value of −14.3 J/kg K, −5.3 J/kg K and −10.3 J/kg K for a field change of 50 kOe near 66 K, 52 K and 42 K, respectively. Low temperature magnetic ordering with enhanced anisotropic effects in Tb{sub 2}Ni{sub 2.35}Si{sub 0.65} and Dy{sub 2}Ni{sub 2.35}Si{sub 0.65} is accompanied by a positive magnetocaloric effect with isothermal magnetic entropy changes of +12.8 J/kg K and ~+9.9 J/kg K, respectively at 7 K for a field change of 50 kOe. - Graphical abstract: The (Gd, Tb, Dy){sub 2}Ni{sub 2.35}Si{sub 0.65} supplement the series of Mo{sub 2}NiB{sub 2}-type rare earth compounds, whereas the (Dy, Ho){sub 2}Ni{sub 2.5}Si{sub 0.5} supplement the series of La{sub 2}Ni{sub 3}-type rare earth compounds. The variation of alloy’s composition by ~3 at% i.e. from Dy{sub 2}Ni{sub 2.35}Si{sub 0.65} to Dy{sub 2}Ni{sub 2.5}Si{sub 0.5} leads to significant transformation of crystal structure of compound with different variant of distortion of Po-type rare earth sublattice, as in Gd–Co–Ga and Er–Ni–In systems: the Mo{sub 2}NiB{sub 2}-type Gd{sub 2}Co{sub 2}Ga and La{sub 2}Ni{sub 3}-type Gd{sub 2}Co{sub 2.9}Ga{sub 0.1}, and Mo{sub 2}FeB{sub 2}-type Er{sub 2}Ni{sub 1.78}In and Mn{sub 2}AlB{sub 2}-type Er{sub 2}Ni{sub 2}In. Magnetization measurements indicate collinear ferromagnetic ordering of Mo{sub 2}NiB{sub 2}-type Gd{sub 2}Ni{sub 2.35}Si{sub 0.65} and a complex antiferromagnetic ordering with low-temperature metamagnetic nature for Mo{sub 2}NiB{sub 2}-type Tb{sub 2}Ni{sub 2.35}Si{sub 0.65} compounds. However, neutron diffraction study in zero applied field of Tb{sub 2}Ni{sub 2.35}Si{sub 0.65} reveals c-axis pure antiferromagnetic ordering of terbium sublattice with K=[1/2, 0, 1/2] propagation vector. Magnetization measurements indicate ferromagnetic order with coexisting antiferromagnetic interactions and low-temperature metamagnetic state for La{sub 2}Ni{sub 3}-type Dy{sub 2}Ni{sub 2.5}Si{sub 0.5}. We suggest possible polymorphism in other Mo{sub 2}FeB{sub 2}-type, Mo{sub 2}NiB{sub 2}-type, La{sub 2}Ni{sub 3}-type and Mn{sub 2}AlB{sub 2}-type rare earth compounds with corresponding change in their magnetic properties. - Highlights: • (Gd, Tb, Dy){sub 2}Ni{sub 2.35}Si{sub 0.65} compounds crystallize in the Mo{sub 2}NiB{sub 2}-type structure. • (Dy, Ho){sub 2}Ni{sub 2.5}Si{sub 0.5} compounds crystallize in the La{sub 2}Ni{sub 3}-type structure. • Gd{sub 2}Ni{sub 2.35}Si{sub 0.65} shows pure ferromagnetic type ordering. • Tb{sub 2}Ni{sub 2.35}Si{sub 0.65} and Dy{sub 2}Ni{sub 2.5}Si{sub 0.5} show mixed ferro-antiferromagnetic ordering. • Tb{sub 2}Ni{sub 2.35}Si{sub 0.65} and Dy{sub 2}Ni{sub 2.5}Si{sub 0.5} exhibit low-temperature metamagnetic behaviour.« less

Human isolates of Listeria monocytogenes in Sweden during half a century (1958-2010).

PubMed

Lopez-Valladares, G; Tham, W; Parihar, V Singh; Helmersson, S; Andersson, B; Ivarsson, S; Johansson, C; Ringberg, H; Tjernberg, I; Henriques-Normark, B; Danielsson-Tham, M-L

2014-11-01

Isolates of Listeria monocytogenes (n = 932) isolated in Sweden during 1958-2010 from human patients with invasive listeriosis were characterized by serotyping and pulsed-field gel electrophoresis (PFGE) (AscI). Of the 932 isolates, 183 different PFGE types were identified, of which 83 were each represented by only one isolate. In all, 483 serovar 1/2a isolates were distributed over 114 PFGE types; 90 serovar 1/2b isolates gave 32 PFGE types; 21 serovar 1/2c isolates gave nine PFGE types; three serovar 3b isolates gave one PFGE type; and, 335 serovar 4b isolates gave 31 PFGE types. During the 1980s in Sweden, several serovar 4b cases were associated with the consumption of European raw soft cheese. However, as cheese-production hygiene has improved, the number of 4b cases has decreased. Since 1996, serovar 1/2a has been the dominant L. monocytogenes serovar in human listeriosis in Sweden. Therefore, based on current serovars and PFGE types, an association between human cases of listeriosis and the consumption of vacuum-packed gravad and cold-smoked salmon is suggested.

Do two current canine parvovirus type 2 and 2b vaccines provide protection against the new type 2c variant?

PubMed

Larson, Laurie J; Schultz, R D

2008-01-01

Three groups (n=9 or 10) of 12-week-old canine parvovirus type 2 (CPV-2) antibody-negative puppies were vaccinated: one group with a product containing modified-live CPV-2b (Galaxy DA2PPv; Schering-Plough Animal Health), one group with a product containing modified-live CPV-2 (Continuum DAP, Intervet), and one group (controls) with sterile saline. All puppies receiving CPV-2 and CPV-2b vaccines developed antibody as determined by the hemagglutination inhibition assay. All groups of puppies were challenged with a combination of virulent CPV-2b and CPV-2c 5 weeks after vaccination. All puppies in the CPV-2 and CPV-2b vaccinated groups were protected from disease, whereas all control group puppies developed disease and 50% died or were euthanized. This study demonstrated that the CPV-2 and CPV-2b vaccine components of the Continuum DAP and Galaxy DA2PPv products, respectively, provided protection against the CPV-2b virus and also provided complete protection against the new CPV-2c variant.

An ErbB2-Muc4 complex in rat ocular surface epithelia.

PubMed

Swan, Jeremy S; Arango, Maria E; Carothers Carraway, Coralie A; Carraway, Kermit L

2002-05-01

To show the presence and localization of type 1 growth factor receptors (ErbB2, ErbB3 and ErbB4) in rat corneal and conjunctival epithelia and investigate the association of ErbB2 with its intramembrane ligand Muc4. Methacarn-fixed, paraffin-embedded sections of corneas and eyelids from female adult rats were immunocytochemically stained using antibodies against the ErbB receptors and Muc4. Sequential immunoprecipitation and immunoblot analyses were performed on epithelial lysates to investigate the presence of a complex of Muc4 and ErbB2 in corneal and conjunctival epithelia. Immunocytochemical staining demonstrated the presence of ErbB2, ErbB3 and ErbB4 growth factor receptors throughout the rat corneal and conjunctival epithelia. Co-immunoprecipitation of the epithelial lysates demonstrated that Muc4 and ErbB2 are present as a complex. The three type 1 growth factor receptors (ErbB2, ErbB3 and ErbB4) are present in the rat corneal and conjunctival epithelia, and ErbB2 is at least partly associated with Muc4. This demonstration of the presence and localization of these three type 1 growth factor receptors may help in understanding how these receptors contribute to ocular epithelial behavior and functions.

Contribution of B2 receptors for bradykinin in Arthus reaction-induced plasma extravasation in wild-type or B2 transgenic knockout mice

PubMed Central

Samadfam, R; Teixeira, C; Bkaily, G; Sirois, P; de Brum-Fernandes, A; D'Orleans-Juste, P

2000-01-01

The aim of the present study was to investigate the contribution of bradykinin (BK) B1 and B2 receptors in a model of type III hypersensitivity, the reverse passive Arthus reaction (RPA), in wild-type mice and transgenic B2 knockout littermates.BK (10 μg mouse−1) or bovine serum albumin (0.5 mg mouse−1) induced a sustained Evans blue extravasation for more than 80 min in naive or rabbit anti-bovine serum albumin-treated mice (RPA model), respectively. The response to the two stimuli was prevented by the B2 receptor antagonist, HOE-140, but not by [Leu8]desArg9-BK (B1 receptor antagonist).In contrast to the wild-type littermates, RPA and bradykinin were unable to trigger an increase in plasma extravasation in B2 knockout mice.Furthermore, endothelin-1 (5 μg mouse−1) and a selective NK-1 receptor agonist [Sar9,Met (O2)11]-SP (20 μg mouse−1), triggered a significant increase in peritoneal plasma extravasation in both wild-type and B2 knockout animals.A pretreatment with indomethacin (200 μg mouse−1) significantly reduced the RPA-induced but not the BK-induced increase in Evans blue extravasation. Furthermore, RPA, but not BK, triggered a significant indomethacin-sensitive increase in peritoneal prostaglandin E2 content.Our results suggest a pivotal role for B2 receptors in the mechanism of plasma extravasation which occurs during the reverse passive Arthus reaction in the mouse. Moreover, our results suggest an important contribution of prostanoids in the plasma leakage mechanisms triggered by RPA but not by bradykinin. PMID:10780980

Dietary Lipid Levels Influence Lipid Deposition in the Liver of Large Yellow Croaker (Larimichthys crocea) by Regulating Lipoprotein Receptors, Fatty Acid Uptake and Triacylglycerol Synthesis and Catabolism at the Transcriptional Level.

PubMed

Yan, Jing; Liao, Kai; Wang, Tianjiao; Mai, Kangsen; Xu, Wei; Ai, Qinghui

2015-01-01

Ectopic lipid accumulation has been observed in fish fed a high-lipid diet. However, no information is available on the mechanism by which dietary lipid levels comprehensively regulate lipid transport, uptake, synthesis and catabolism in fish. Therefore, the present study aimed to gain further insight into how dietary lipids affect lipid deposition in the liver of large yellow croaker(Larimichthys crocea). Fish (150.00±4.95 g) were fed a diet with a low (6%), moderate (12%, the control diet) or high (18%) crude lipid content for 10 weeks. Growth performance, plasma biochemical indexes, lipid contents and gene expression related to lipid deposition, including lipoprotein assembly and clearance, fatty acid uptake and triacylglycerol synthesis and catabolism, were assessed. Growth performance was not significantly affected. However, the hepato-somatic and viscera-somatic indexes as well as plasma triacylglycerol, non-esterified fatty acids and LDL-cholesterol levels were significantly increased in fish fed the high-lipid diet. In the livers of fish fed the high-lipid diet, the expression of genes related to lipoprotein clearance (LDLR) and fatty acid uptake (FABP11) was significantly up-regulated, whereas the expression of genes involved in lipoprotein assembly (apoB100), triacylglycerol synthesis and catabolism (DGAT2, CPT I) was significantly down-regulated compared with fish fed the control diet, and hepatic lipid deposition increased. In fish fed the low-lipid diet, the expression of genes associated with lipoprotein assembly and clearance (apoB100, LDLR, LRP-1), fatty acid uptake (CD36, FATP1, FABP3) and triacylglycerol synthesis (FAS) was significantly increased, whereas the expression of triacylglycerol catabolism related genes (ATGL, CPT I) was reduced compared with fish fed the control diet. However, hepatic lipid content in fish fed the low-lipid diet decreased mainly due to low dietary lipid intake. In summary, findings of this study provide molecular insight into the role of lipid deposition in the liver in response to different dietary lipid contents.

Dietary Lipid Levels Influence Lipid Deposition in the Liver of Large Yellow Croaker (Larimichthys crocea) by Regulating Lipoprotein Receptors, Fatty Acid Uptake and Triacylglycerol Synthesis and Catabolism at the Transcriptional Level

PubMed Central

Yan, Jing; Liao, Kai; Wang, Tianjiao; Mai, Kangsen; Xu, Wei; Ai, Qinghui

2015-01-01

Ectopic lipid accumulation has been observed in fish fed a high-lipid diet. However, no information is available on the mechanism by which dietary lipid levels comprehensively regulate lipid transport, uptake, synthesis and catabolism in fish. Therefore, the present study aimed to gain further insight into how dietary lipids affect lipid deposition in the liver of large yellow croaker(Larimichthys crocea). Fish (150.00±4.95 g) were fed a diet with a low (6%), moderate (12%, the control diet) or high (18%) crude lipid content for 10 weeks. Growth performance, plasma biochemical indexes, lipid contents and gene expression related to lipid deposition, including lipoprotein assembly and clearance, fatty acid uptake and triacylglycerol synthesis and catabolism, were assessed. Growth performance was not significantly affected. However, the hepato-somatic and viscera-somatic indexes as well as plasma triacylglycerol, non-esterified fatty acids and LDL-cholesterol levels were significantly increased in fish fed the high-lipid diet. In the livers of fish fed the high-lipid diet, the expression of genes related to lipoprotein clearance (LDLR) and fatty acid uptake (FABP11) was significantly up-regulated, whereas the expression of genes involved in lipoprotein assembly (apoB100), triacylglycerol synthesis and catabolism (DGAT2, CPT I) was significantly down-regulated compared with fish fed the control diet, and hepatic lipid deposition increased. In fish fed the low-lipid diet, the expression of genes associated with lipoprotein assembly and clearance (apoB100, LDLR, LRP-1), fatty acid uptake (CD36, FATP1, FABP3) and triacylglycerol synthesis (FAS) was significantly increased, whereas the expression of triacylglycerol catabolism related genes (ATGL, CPT I) was reduced compared with fish fed the control diet. However, hepatic lipid content in fish fed the low-lipid diet decreased mainly due to low dietary lipid intake. In summary, findings of this study provide molecular insight into the role of lipid deposition in the liver in response to different dietary lipid contents. PMID:26114429

Mouse senile amyloid deposition is suppressed by adenovirus-mediated overexpression of amyloid-resistant apolipoprotein A-II.

PubMed

Chiba, T; Kogishi, K; Wang, J; Xia, C; Matsushita, T; Miyazaki, J; Saito, I; Hosokawa, M; Higuchi, K

1999-10-01

Apolipoprotein A-II (apoA-II), the second most abundant apolipoprotein of serum high density lipoprotein, deposits as an amyloid fibril (AApoAII) in old mice. Mouse strains with a high incidence of senile amyloidosis have the type C apoA-II gene (Apoa2(c)), whereas the strains with a low incidence of amyloidosis have the type B apoA-II gene (Apoa2(b)). In this study, to investigate whether the type B apoA-II protein inhibits the extension of amyloid fibrils, we constructed an adenovirus vector bearing the Apoa2(b) cDNA (Adex1CATApoa2(b)), which is expressed under the control of a hepatocyte-specific promoter. The mice were infected with Adex1CATApoa2(b) before induction of amyloidosis by the injection of AApoAII amyloid fibril seeds. Compared with the mice infected with the control virus, amyloid deposition was suppressed significantly in the mice infected with Adex1CATApoa2(b). Fluorometry using thioflavine T also revealed that AApoAII fibril extension was inhibited by the addition of type B apoA-II in vitro. Thus, we propose that Apoa2(b) contributes as an active inhibitor of amyloid fibril extension and overexpression of amyloid-resistant gene variant may be an attractive therapeutic target in amyloidosis.

Lack of Additive Effects of Resveratrol and Energy Restriction in the Treatment of Hepatic Steatosis in Rats

PubMed Central

Aguirre, Leixuri; Rolo, Anabela P.; Palmeira, Carlos M.; Portillo, María P.

2017-01-01

The aims of the present study were to analyze the effect of resveratrol on liver steatosis in obese rats, to compare the effects induced by resveratrol and energy restriction and to research potential additive effects. Rats were initially fed a high-fat high-sucrose diet for six weeks and then allocated in four experimental groups fed a standard diet: a control group, a resveratrol-treated group, an energy restricted group and a group submitted to energy restriction and treated with resveratrol. We measured liver triacylglycerols, transaminases, FAS, MTP, CPT1a, CS, COX, SDH and ATP synthase activities, FATP2/FATP5, DGAT2, PPARα, SIRT1, UCP2 protein expressions, ACC and AMPK phosphorylation and PGC1α deacetylation. Resveratrol reduced triacylglycerols compared with the controls, although this reduction was lower than that induced by energy restriction. The mechanisms of action were different. Both decreased protein expression of fatty acid transporters, thus suggesting reduced fatty acid uptake from blood stream and liver triacylglycerol delivery, but only energy restriction reduced the assembly. These results show that resveratrol is useful for liver steatosis treatment within a balanced diet, although its effectiveness is lower than that of energy restriction. However, resveratrol is unable to increase the reduction in triacylglycerol content induced by energy restriction. PMID:28696376

Lack of Additive Effects of Resveratrol and Energy Restriction in the Treatment of Hepatic Steatosis in Rats.

PubMed

Milton-Laskibar, Iñaki; Aguirre, Leixuri; Fernández-Quintela, Alfredo; Rolo, Anabela P; Soeiro Teodoro, João; Palmeira, Carlos M; Portillo, María P

2017-07-11

The aims of the present study were to analyze the effect of resveratrol on liver steatosis in obese rats, to compare the effects induced by resveratrol and energy restriction and to research potential additive effects. Rats were initially fed a high-fat high-sucrose diet for six weeks and then allocated in four experimental groups fed a standard diet: a control group, a resveratrol-treated group, an energy restricted group and a group submitted to energy restriction and treated with resveratrol. We measured liver triacylglycerols, transaminases, FAS, MTP, CPT1a, CS, COX, SDH and ATP synthase activities, FATP2/FATP5, DGAT2, PPARα, SIRT1, UCP2 protein expressions, ACC and AMPK phosphorylation and PGC1α deacetylation. Resveratrol reduced triacylglycerols compared with the controls, although this reduction was lower than that induced by energy restriction. The mechanisms of action were different. Both decreased protein expression of fatty acid transporters, thus suggesting reduced fatty acid uptake from blood stream and liver triacylglycerol delivery, but only energy restriction reduced the assembly. These results show that resveratrol is useful for liver steatosis treatment within a balanced diet, although its effectiveness is lower than that of energy restriction. However, resveratrol is unable to increase the reduction in triacylglycerol content induced by energy restriction.

A naturally occurring InDel variation in BraA.FLC.b (BrFLC2) associated with flowering time variation in Brassica rapa.

PubMed

Wu, Jian; Wei, Keyun; Cheng, Feng; Li, Shikai; Wang, Qian; Zhao, Jianjun; Bonnema, Guusje; Wang, Xiaowu

2012-08-28

Flowering time is an important trait in Brassica rapa crops. FLOWERING LOCUS C (FLC) is a MADS-box transcription factor that acts as a potent repressor of flowering. Expression of FLC is silenced when plants are exposed to low temperature, which activates flowering. There are four copies of FLC in B. rapa. Analyses of different segregating populations have suggested that BraA.FLC.a (BrFLC1) and BraA.FLC.b (BrFLC2) play major roles in controlling flowering time in B. rapa. We analyzed the BrFLC2 sequence in nine B. rapa accessions, and identified a 57-bp insertion/deletion (InDel) across exon 4 and intron 4 resulting in a non-functional allele. In total, three types of transcripts were identified for this mutated BrFLC2 allele. The InDel was used to develop a PCR-based marker, which was used to screen a collection of 159 B. rapa accessions. The deletion genotype was present only in oil-type B. rapa, including ssp. oleifera and ssp. tricolaris, and not in other subspecies. The deletion genotype was significantly correlated with variation in flowering time. In contrast, the reported splicing site variation in BrFLC1, which also leads to a non-functional locus, was detected but not correlated with variation in flowering time in oil-type B. rapa, although it was correlated with variation in flowering time in vegetable-type B. rapa. Our results suggest that the naturally occurring deletion mutation across exon 4 and intron 4 in BrFLC2 gene contributes greatly to variation in flowering time in oil-type B. rapa. The observed different relationship between BrFLC1 or BrFLC2 and flowering time variation indicates that the control of flowering time has evolved separately between oil-type and vegetable-type B. rapa groups.

HLA-B*5808, a new HLA-B allele characterized by sequence based typing.

PubMed

Poli, F; Crespiatico, L; Frison, S; Longhi, E; Marlianici, E; Scalamogna, M

2003-12-01

This brief communication describes a new HLA-B allele (HLA-B*5808) detected in an Italian white volunteer bone marrow donor. With serology, this subject was typed as HLA-B15,17, whereas with molecular biology B*15, B*51, B*52 and/or B*58 could be assigned. In order to clarify the results, direct and cloning sequencing of exons 2, 3 and 4 were carried out. This new allele is identical to HLA-B*5801 in exon 2 except for a silent point mutation at nucleotide 141 where a C is substituted by a T; exons 3 and 4 are typical of HLA-B*51, B*52 and B*78. The peculiar sequence of B*5808 could explain the discrepancy between the serological and molecular typing results.

Fall in readmission rate for heart failure after implementation of B-type natriuretic peptide testing for discharge decision: a retrospective study.

PubMed

Valle, Roberto; Aspromonte, Nadia; Carbonieri, Emanuele; D'Eri, Alessandra; Feola, Mauro; Giovinazzo, Prospero; Noventa, Federica; Prevaldi, Carolina; Barro, Sabrina; Milani, Loredano

2008-06-06

B-type natriuretic peptide is the most powerful predictor of long term prognosis in patients hospitalised with heart failure. On an outsetting basis, a decrease in B-type natriuretic peptide levels is associated to a decrease in event rate for outpatients managed using the neuro-hormone levels as the target in heart failure therapy. We have retrospectively checked whether the addition of pre-discharge B-type natriuretic peptide levels to a clinical-instrumental decisional score for discharge decision in patients admitted for heart failure reduced readmission rate for heart failure and related cost. We studied two series of consecutive patients admitted to the Heart Failure Unit due to acute heart failure as a main diagnosis. One-hundred and forty-nine patients discharged on the basis of the sole clinical acumen were compared to one hundred and sixty-six subjects discharged adding B-type natriuretic peptide levels to the decisional score. During a six-month follow-up period, there were 52 readmissions (35%) among the clinical group (n=149) compared with 38 (23%) readmissions in the B-type natriuretic peptide group (n=166) (chi(2)=5.5; P=0.02). Survival did not differ between groups (87%). Changes in B-type natriuretic peptide values were correlated to clinical events: a B-type natriuretic peptide value on discharge of < or =250 pg/ml or a reduction of > or =30% in B-type natriuretic peptide values predicted a 23% event rate (death, plus readmission for heart failure), whereas a far higher percentage (71%) were observed in the remaining patients (chi(2)=32.7; P=0.001). Likewise, the overall costs of care were lower (-7%) in the B-type natriuretic peptide group: 2.781+/-923 vs 2.978+/-1.057 euros per patient respectively. our study suggest that the addition of pre-discharge B-type natriuretic peptide levels to a clinical-instrumental decisional score for discharge decision in patients admitted for heart failure may contribute to reduce the number of readmissions and related cost.

Identification of Anion Channels Responsible for Fluoride Resistance in Oral Streptococci

PubMed Central

Takeshita, Toru; Yamashita, Yoshihisa

2016-01-01

Recently, it has been reported that eriC and crcB are involved in bacterial fluoride resistance. However, the fluoride-resistance mechanism in oral streptococci remains unclear. BLAST studies showed that two types of eriCs (eriC1 and eriC2) and two types of crcBs (crcB1 and crcB2) are present across 18 oral streptococci, which were identified in ≥ 10% of 166 orally healthy subjects with ≥ 0.01% of the mean relative abundance. They were divided into three groups based on the distribution of these four genes: group I, only eriC1; group II, eriC1 and eriC2; and group III, eriC2, crcB1, and crcB2. Group I consisted of Streptococcus mutans, in which one of the two eriC1s predominantly affected fluoride resistance. Group II consisted of eight species, and eriC1 was responsible for fluoride resistance, but eriC2 was not, in Streptococcus anginosus as a representative species. Group III consisted of nine species, and both crcB1 and crcB2 were crucial for fluoride resistance, but eriC2 was not, in Streptococcus sanguinis as a representative species. Based on these results, either EriC1 or CrcBs play a role in fluoride resistance in oral streptococci. Complementation between S. mutans EriC1 and S. sanguinis CrcB1/CrcB2 was confirmed in both S. mutans and S. sanguinis. However, neither transfer of S. sanguinis CrcB1/CrcB2 into wild-type S. mutans nor S. mutans EriC1 into wild-type S. sanguinis increased the fluoride resistance of the wild-type strain. Co-existence of different F− channels (EriC and CrcB) did not cause the additive effect on fluoride resistance in oral Streptococcus species. PMID:27824896

Characterization of fimbriae of Actinomyces naeslundii N16 using monoclonal and polyclonal antibodies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bragg, S.L.

1988-01-01

Two populations of fimbriae, which differ both in antigenicity and biological activity, have been identified on Actinomyces viscosus T14V cells. Although A. naeslundii serotype 1 isolates possess only one of these fimbrial populations (type 2 fimbriae), there was functional evidence to suggest that A. naeslundii serotype 3 strain N16 had both types of fimbriae. The purpose of this study was to characterize the fimbriae of A. naeslundii N16 immunologically by using both monoclonal and polyclonal antibodies. Three monoclonal antibodies (MAbs) to N16 were produced; all three bound to N16 fimbriae as determined by immunoelectron microscopy. In a solid-phase radioimmunoassay MAbmore » 3B5.A1 reacted with 100% of the A. naeslundii serotype 3 isolates tested, but it did not react with any heterologous isolates. Type 1 and type 2 fimbriae were detected in Lancefield extracts of N16 cells by crossed immunoelectrophoresis (XIEP) using rabbit antiserum against N16 whole cells. When {sup 125}I-MAb 3B5.A1 was also incorporated into the gel, autoradiography indicated that MAb 3B5.A1 was specific for type 2 fimbriae. The N16 type 2 fimbriae were purified by gel filtration and immunoaffinity chromatography on a MAb 3B5.A1 column. Fimbriae-specific polyclonal and monoclonal antibodies were used in various immunological assays to determine that (a) N16 type 1 fimbriae are not related antigenically to type 2 fimbriae, (b) each type of fimbriae has epitopes that are present on the corresponding fimbriae of certain heterologous strains, and (c) MAb 3B5.A1 recognizes a serotype-specific epitope residing on the type 2 fimbriae of A. naeslundii serotype 3 strains.« less

Diversity of Group I and II Clostridium botulinum Strains from France Including Recently Identified Subtypes

PubMed Central

Mazuet, Christelle; Legeay, Christine; Sautereau, Jean; Ma, Laurence; Bouchier, Christiane; Bouvet, Philippe; Popoff, Michel R.

2016-01-01

In France, human botulism is mainly food-borne intoxication, whereas infant botulism is rare. A total of 99 group I and II Clostridium botulinum strains including 59 type A (12 historical isolates [1947–1961], 43 from France [1986–2013], 3 from other countries, and 1 collection strain), 31 type B (3 historical, 23 recent isolates, 4 from other countries, and 1 collection strain), and 9 type E (5 historical, 3 isolates, and 1 collection strain) were investigated by botulinum locus gene sequencing and multilocus sequence typing analysis. Historical C. botulinum A strains mainly belonged to subtype A1 and sequence type (ST) 1, whereas recent strains exhibited a wide genetic diversity: subtype A1 in orfX or ha locus, A1(B), A1(F), A2, A2b2, A5(B2′) A5(B3′), as well as the recently identified A7 and A8 subtypes, and were distributed into 25 STs. Clostridium botulinum A1(B) was the most frequent subtype from food-borne botulism and food. Group I C. botulinum type B in France were mainly subtype B2 (14 out of 20 historical and recent strains) and were divided into 19 STs. Food-borne botulism resulting from ham consumption during the recent period was due to group II C. botulinum B4. Type E botulism is rare in France, 5 historical and 1 recent strains were subtype E3. A subtype E12 was recently identified from an unusual ham contamination. Clostridium botulinum strains from human botulism in France showed a wide genetic diversity and seems to result not from a single evolutionary lineage but from multiple and independent genetic rearrangements. PMID:27189984

[Vitamin B12 Deficiency in Type 2 Diabetes Mellitus].

PubMed

Tavares Bello, Carlos; Capitão, Ricardo Miguel; Sequeira Duarte, João; Azinheira, Jorge; Vasconcelos, Carlos

2017-10-31

Type 2 diabetes mellitus is a common disease, affecting up to 13.1% of the Portuguese population. In addition to the known micro and macrovascular complications, drug side effects constitute a major concern, leading to changes in the treatment guidelines, which favor safety over efficacy. Metformin is the first-line pharmacological treatment for most patients with type 2 diabetes mellitus; however, it has been associated with vitamin B12 deficiency in up to 30% of treated patients. The authors describe the prevalence of vitamin B12 deficiency in a diabetic population and explore the possible underlying factors. Retrospective, observational study. Clinical and laboratory data of type 2 diabetes mellitus patients whose vitamin B12 status was evaluated in the last decade (2005 - 2016) were analyzed. Patients with known malabsorptive syndromes or having undergone bariatric surgery were excluded from the study. Statistical analysis of the data was done and the results were considered statistically significant at p values < 0.05. The study included a total of 1007 patients (58% women) with a mean age of 66.4 ± 12.2 years and 11 ± 10.4 years of type 2 diabetes mellitus duration. These patients had a high prevalence of complications: diabetic renal disease 47.7%, neuropathy 9.2%, retinopathy 14.9%, coronary artery disease 8.4%, cerebrovascular disease 10.9%, and peripheral arterial disease 5.5%. Vitamin B12 deficiency (< 174 ng / dL) was present in 21.4% of the population and this subgroup was older (68.4 vs 65.8 years, p = 0.006), had a longer type 2 diabetes mellitus duration (13.35 vs 10.36 years; p = 0.001), higher prevalence of retinopathy (20.9% vs 13.3%; p = 0.005) and thyroid dysfunction (34% vs 23.7%; p = 0.002). Vitamin B12 deficiency was also more frequent in patients treated with metformin (24.7% vs 15.8%; p = 0.017), antiplatelet agents (25.4% vs 16.2%, p < 0.001), and calcium channel blockers (26.8% vs 18.2%; p = 0.001). After adjustment for possible confounders, the variables associated with B12 deficiency were: metformin, hypothyroidism, age and type 2 diabetes mellitus duration. Despite the retrospective design, the results report a high prevalence of vitamin B12 deficiency in the type 2 diabetic population. This study also demonstrates that the B12 deficiency risk is higher in older people, with longer diabetes mellitus duration, hypothyroidism and treated with metformin. Further studies are needed to identify the risk factors for the B12 deficit. The recognition of these variables will contribute to optimize the screening and prevention of the B12 deficiency in type 2 diabetes mellitus.

A Protein Linkage Map of the P2 Nonstructural Proteins of Poliovirus

PubMed Central

Cuconati, Andrea; Xiang, Wenkai; Lahser, Frederick; Pfister, Thomas; Wimmer, Eckard

1998-01-01

The yeast two-hybrid system was used to catalog all detectable interactions among the P2 nonstructural cleavage products of poliovirus type 1 (Mahoney). Evidence has been obtained for specific associations among 2Apro, 2BC, 2C, and 2B. Specifically, 2Apro can interact with itself and 2BC and its cleavage products (2B and 2C) interact in all possible combinations, with the exception of 2C/2C. Detected interactions were confirmed in vitro by a glutathione S-transferase pulldown assay, which allowed us to detect 2C/2C association. trans-dominant-negative mutants of 2B (K. Johnson and P. J. Sarnow, J. Virol. 65:4341–4349, 1991) were examined and were found to retain interaction with wild-type 2B, perhaps reflecting a need for 2B multimerization in viral RNA replication. The multimerization of 2B was examined further by screening a mutagenized library for 2B variants that have lost the ability to bind wild-type 2B. The screen identified two nonconservative missense mutations within a central hydrophobic region, as well as truncations and frameshifts that implicate the C terminus in homointeraction. Introduction of the missense mutations into the genome of the virus conferred a quasi-infectious phenotype, an observation strongly suggesting that the 2B/2B interaction is required for replication of the viral genome. PMID:9445030

Electronic, structural and magnetic studies of niobium borides of group 8 transition metals, Nb2MB2 (M=Fe, Ru, Os) from first principles calculations

NASA Astrophysics Data System (ADS)

Touzani, Rachid St.; Fokwa, Boniface P. T.

2014-03-01

The Nb2FeB2 phase (U3Si2-type, space group P4/mbm, no. 127) is known for almost 50 years, but until now its magnetic properties have not been investigated. While the synthesis of Nb2OsB2 (space group P4/mnc, no. 128, a twofold superstructure of U3Si2-type) with distorted Nb-layers and Os2-dumbbells was recently achieved, "Nb2RuB2" is still not synthesized and its crystal structure is yet to be revealed. Our first principles density functional theory (DFT) calculations have confirmed not only the experimental structures of Nb2FeB2 and Nb2OsB2, but also predict "Nb2RuB2" to crystalize with the Nb2OsB2 structure type. According to chemical bonding analysis, the homoatomic B-B interactions are optimized and very strong, but relatively strong heteroatomic M-B, B-Nb and M-Nb bonds (M=Fe, Ru, Os) are also found. These interactions, which together build a three-dimensional network, are mainly responsible for the structural stability of these ternary borides. The density-of-states at the Fermi level predicts metallic behavior, as expected, from metal-rich borides. Analysis of possible magnetic structures concluded preferred antiferromagnetic ordering for Nb2FeB2, originating from ferromagnetic interactions within iron chains and antiferromagnetic exchange interactions between them.

Gene expression signatures of energetic acclimatisation in the reef building coral Acropora millepora.

PubMed

Bay, Line K; Guérécheau, Aurélie; Andreakis, Nikos; Ulstrup, Karin E; Matz, Mikhail V

2013-01-01

Understanding the mechanisms by which natural populations cope with environmental stress is paramount to predict their persistence in the face of escalating anthropogenic impacts. Reef-building corals are increasingly exposed to local and global stressors that alter nutritional status causing reduced fitness and mortality, however, these responses can vary considerably across species and populations. We compare the expression of 22 coral host genes in individuals from an inshore and an offshore reef location using quantitative Reverse Transcription-PCR (qRT-PCR) over the course of 26 days following translocation into a shaded, filtered seawater environment. Declines in lipid content and PSII activity of the algal endosymbionts (Symbiodinium ITS-1 type C2) over the course of the experiment indicated that heterotrophic uptake and photosynthesis were limited, creating nutritional deprivation conditions. Regulation of coral host genes involved in metabolism, CO2 transport and oxidative stress could be detected already after five days, whereas PSII activity took twice as long to respond. Opposing expression trajectories of Tgl, which releases fatty acids from the triacylglycerol storage, and Dgat1, which catalyses the formation of triglycerides, indicate that the decline in lipid content can be attributed, at least in part, by mobilisation of triacylglycerol stores. Corals from the inshore location had initially higher lipid content and showed consistently elevated expression levels of two genes involved in metabolism (aldehyde dehydrogenase) and calcification (carbonic anhydrase). Coral host gene expression adjusts rapidly upon change in nutritional conditions, and therefore can serve as an early signature of imminent coral stress. Consistent gene expression differences between populations indicate that corals acclimatize and/or adapt to local environments. Our results set the stage for analysis of these processes in natural coral populations, to better understand the responses of coral communities to global climate change and to develop more efficient management strategies.

(±)-Uncarilins A and B, Dimeric Isoechinulin-Type Alkaloids from Uncaria rhynchophylla.

PubMed

Geng, Chang-An; Huang, Xiao-Yan; Ma, Yun-Bao; Hou, Bo; Li, Tian-Ze; Zhang, Xue-Mei; Chen, Ji-Jun

2017-04-28

(±)-Uncarilins A and B (1a/1b and 2a/2b), two pairs of unusual dimeric isoechinulin-type enantiomers with a symmetric four-membered core, were isolated from Uncaria rhynchophylla driven by LCMS-IT-TOF analyses. Their structures were elucidated by extensive 1D and 2D NMR spectra, X-ray diffraction, and ECD spectroscopic data. (-)-Uncarilin B (2a) showed activities on MT 1 and MT 2 receptors with agonistic rates of 11.26% and 52.44% at a concentration of 0.25 mM.

Novel Nine-Exon AR Transcripts (Exon 1/Exon 1b/Exons 2–8) in Normal and Cancerous Breast and Prostate Cells

PubMed Central

Hu, Dong Gui; McKinnon, Ross A.; Hulin, Julie-Ann; Mackenzie, Peter I.; Meech, Robyn

2016-01-01

Nearly 20 different transcripts of the human androgen receptor (AR) are reported with two currently listed as Refseq isoforms in the NCBI database. Isoform 1 encodes wild-type AR (type 1 AR) and isoform 2 encodes the variant AR45 (type 2 AR). Both variants contain eight exons: they share common exons 2–8 but differ in exon 1 with the canonical exon 1 in isoform 1 and the variant exon 1b in isoform 2. Splicing of exon 1 or exon 1b is reported to be mutually exclusive. In this study, we identified a novel exon 1b (1b/TAG) that contains an additional TAG trinucleotide upstream of exon 1b. Moreover, we identified AR transcripts in both normal and cancerous breast and prostate cells that contained either exon 1b or 1b/TAG spliced between the canonical exon 1 and exon 2, generating nine-exon AR transcripts that we have named isoforms 3a and 3b. The proteins encoded by these new AR variants could regulate androgen-responsive reporters in breast and prostate cancer cells under androgen-depleted conditions. Analysis of type 3 AR-GFP fusion proteins showed partial nuclear localization in PC3 cells under androgen-depleted conditions, supporting androgen-independent activation of the AR. Type 3 AR proteins inhibited androgen-induced growth of LNCaP cells. Microarray analysis identified a small set of type 3a AR target genes in LNCaP cells, including genes known to modulate growth and proliferation of prostate cancer (PCGEM1, PEG3, EPHA3, and EFNB2) or other types of human cancers (TOX3, ST8SIA4, and SLITRK3), and genes that are diagnostic/prognostic biomarkers of prostate cancer (GRINA3, and BCHE). PMID:28035996

A Type I Signal Peptidase Is Required for Pilus Assembly in the Gram-Positive, Biofilm-Forming Bacterium Actinomyces oris

PubMed Central

Siegel, Sara D.

2016-01-01

ABSTRACT The Gram-positive bacterium Actinomyces oris, a key colonizer in the development of oral biofilms, contains 18 LPXTG motif-containing proteins, including fimbrillins that constitute two fimbrial types critical for adherence, biofilm formation, and polymicrobial interactions. Export of these protein precursors, which harbor a signal peptide, is thought to be mediated by the Sec machine and require cleavage of the signal peptide by type I signal peptidases (SPases). Like many Gram-positive bacteria, A. oris expresses two SPases, named LepB1 and LepB2. The latter has been linked to suppression of lethal “glyco-stress,” caused by membrane accumulation of the LPXTG motif-containing glycoprotein GspA when the housekeeping sortase srtA is genetically disrupted. Consistent with this finding, we show here that a mutant lacking lepB2 and srtA was unable to produce high levels of glycosylated GspA and hence was viable. However, deletion of neither lepB1 nor lepB2 abrogated the signal peptide cleavage and glycosylation of GspA, indicating redundancy of SPases for GspA. In contrast, the lepB2 deletion mutant failed to assemble the wild-type levels of type 1 and 2 fimbriae, which are built by the shaft fimbrillins FimP and FimA, respectively; this phenotype was attributed to aberrant cleavage of the fimbrillin signal peptides. Furthermore, the lepB2 mutants, including the catalytically inactive S101A and K169A variants, exhibited significant defects in polymicrobial interactions and biofilm formation. Conversely, lepB1 was dispensable for the aforementioned processes. These results support the idea that LepB2 is specifically utilized for processing of fimbrial proteins, thus providing an experimental model with which to study the basis of type I SPase specificity. IMPORTANCE Sec-mediated translocation of bacterial protein precursors across the cytoplasmic membrane involves cleavage of their signal peptide by a signal peptidase (SPase). Like many Gram-positive bacteria, A. oris expresses two SPases, LepB1 and LepB2. The latter is a genetic suppressor of lethal “glyco-stress” caused by membrane accumulation of glycosylated GspA when the housekeeping sortase srtA is genetically disrupted. We show here that LepB1 and LepB2 are capable of processing GspA, whereas only LepB2 is required for cleavage of fimbrial signal peptides. This is the first example of a type I SPase dedicated to LPXTG motif-containing fimbrial proteins. Thus, A. oris provides an experimental model with which to investigate the specificity mechanism of type I SPases. PMID:27215787

A Type I Signal Peptidase Is Required for Pilus Assembly in the Gram-Positive, Biofilm-Forming Bacterium Actinomyces oris.

PubMed

Siegel, Sara D; Wu, Chenggang; Ton-That, Hung

2016-08-01

The Gram-positive bacterium Actinomyces oris, a key colonizer in the development of oral biofilms, contains 18 LPXTG motif-containing proteins, including fimbrillins that constitute two fimbrial types critical for adherence, biofilm formation, and polymicrobial interactions. Export of these protein precursors, which harbor a signal peptide, is thought to be mediated by the Sec machine and require cleavage of the signal peptide by type I signal peptidases (SPases). Like many Gram-positive bacteria, A. oris expresses two SPases, named LepB1 and LepB2. The latter has been linked to suppression of lethal "glyco-stress," caused by membrane accumulation of the LPXTG motif-containing glycoprotein GspA when the housekeeping sortase srtA is genetically disrupted. Consistent with this finding, we show here that a mutant lacking lepB2 and srtA was unable to produce high levels of glycosylated GspA and hence was viable. However, deletion of neither lepB1 nor lepB2 abrogated the signal peptide cleavage and glycosylation of GspA, indicating redundancy of SPases for GspA. In contrast, the lepB2 deletion mutant failed to assemble the wild-type levels of type 1 and 2 fimbriae, which are built by the shaft fimbrillins FimP and FimA, respectively; this phenotype was attributed to aberrant cleavage of the fimbrillin signal peptides. Furthermore, the lepB2 mutants, including the catalytically inactive S101A and K169A variants, exhibited significant defects in polymicrobial interactions and biofilm formation. Conversely, lepB1 was dispensable for the aforementioned processes. These results support the idea that LepB2 is specifically utilized for processing of fimbrial proteins, thus providing an experimental model with which to study the basis of type I SPase specificity. Sec-mediated translocation of bacterial protein precursors across the cytoplasmic membrane involves cleavage of their signal peptide by a signal peptidase (SPase). Like many Gram-positive bacteria, A. oris expresses two SPases, LepB1 and LepB2. The latter is a genetic suppressor of lethal "glyco-stress" caused by membrane accumulation of glycosylated GspA when the housekeeping sortase srtA is genetically disrupted. We show here that LepB1 and LepB2 are capable of processing GspA, whereas only LepB2 is required for cleavage of fimbrial signal peptides. This is the first example of a type I SPase dedicated to LPXTG motif-containing fimbrial proteins. Thus, A. oris provides an experimental model with which to investigate the specificity mechanism of type I SPases. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Heterogeneity of cerebral TDP-43 pathology in sporadic amyotrophic lateral sclerosis: Evidence for clinico-pathologic subtypes.

PubMed

Takeuchi, Ryoko; Tada, Mari; Shiga, Atsushi; Toyoshima, Yasuko; Konno, Takuya; Sato, Tomoe; Nozaki, Hiroaki; Kato, Taisuke; Horie, Masao; Shimizu, Hiroshi; Takebayashi, Hirohide; Onodera, Osamu; Nishizawa, Masatoyo; Kakita, Akiyoshi; Takahashi, Hitoshi

2016-06-23

Frontotemporal lobar degeneration (FTLD) and amyotrophic lateral sclerosis (ALS) are types of major TDP-43 (43-kDa TAR DNA-binding protein) proteinopathy. Cortical TDP-43 pathology has been analyzed in detail in cases of FTLD-TDP, but is still unclear in cases of ALS. We attempted to clarify the cortical and subcortical TDP-43 pathology in Japanese cases of sporadic ALS (n = 96) using an antibody specific to phosphorylated TDP-43 (pTDP-43). The cases were divided into two groups: those without pTDP-43-positive neuronal cytoplasmic inclusions in the hippocampal dentate granule cells (Type 1, n = 63), and those with such inclusions (Type 2, n = 33). Furthermore, the Type 2 cases were divided into two subgroups based on semi-quantitative estimation of pTDP-43-positive dystrophic neurites (DNs) in the temporal neocortex: Type 2a (accompanied by no or few DNs, n = 22) and Type 2b (accompanied by abundant DNs, n = 11). Clinico-pathologic analysis revealed that cognitive impairment was a feature in patients with Type 2a and Type 2b, but not in those with Type 1, and that importantly, Type 2b is a distinct subtype characterized by a poor prognosis despite the less severe loss of lower motor neurons, the unusual subcortical dendrospinal pTDP-43 pathology, and more prominent glial involvement in cortical pTDP-43 pathology than other two groups. Considering the patient survival time and severity of motor neuron loss in each group, transition from Type 1 to Type 2, or from Type 2a to Type 2b during the disease course appeared unlikely. Therefore, each of these three groups was regarded as an independent subtype.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cao, G. H.; Oertel, C. -G.; Schaarschuch, R.

DyCu and YCu are representatives of the family of CsCl-type B2 rare earth intermetallic compounds that exhibit high room temperature ductility. Structure, orientation relationship, and morphology of the martensites in the equiatomic compounds DyCu and YCu are examined using transmission electron microscopy (TEM). TEM studies show that the martensite structures in DyCu and YCu alloys are virtually identical. The martensite is of orthorhombic CrB-type B33 structure with lattice parameters a = 0.38 nm, b = 1.22 nm, and c = 0.40 nm. (021¯) twins were observed in the B33 DyCu and YCu martensites. The orientation relationship of B33 and B2more » phases is (111¯)[112]B33 || (110)[001]B2. The simulated electron diffraction patterns of the B33 phase are consistent with those of experimental observations. TEM investigations also reveal that a dominant orthorhombic FeB-type B27 martensite with lattice parameters a = 0.71 nm, b = 0.45 nm, and c = 0.54 nm exists in YCu alloy. (11¯ 1) twins were observed in the B27 YCu martensite. As a result, the formation mechanism of B2 to B33 and B2 to B27 phase transformation is discussed.« less

(Pt{sub 1–x}Cu{sub x}){sub 3}Cu{sub 2}B and Pt{sub 9}Cu{sub 3}B{sub 5}, the first examples of copper platinum borides. Observation of superconductivity in a novel boron filled β-Mn-type compound

DOE Office of Scientific and Technical Information (OSTI.GOV)

Salamakha, Leonid P.; Sologub, Oksana, E-mail: oksana.sologub@univie.ac.at; Stöger, Berthold

New ternary copper platinum borides have been synthesized by arc melting of pure elements followed by annealing at 600 °C. The structures have been studied by X-ray single crystal and powder diffraction. (Pt{sub 1−x}Cu{sub x}){sub 3}Cu{sub 2}B (x=0.33) forms a B-filled β-Mn-type structure (space group P4{sub 1}32; a=0.6671(1) nm). Cu atoms are distributed preferentially on the 8c atom sites, whereas the 12d site is randomly occupied by Pt and Cu atoms (0.670(4) Pt±0.330(4) Cu). Boron is located in octahedral voids of the parent β-Mn-type structure. Pt{sub 9}Cu{sub 3}B{sub 5} (space group P-62m; a=0.9048(3) nm, c=0.2908(1) nm) adopts the Pt{sub 9}Zn{submore » 3}B{sub 5–δ}-type structure. It has a columnar architecture along the short translation vector exhibiting three kinds of [Pt{sub 6}] trigonal prism columns (boron filled, boron semi-filled and empty) and Pt channels with a pentagonal cross section filled with Cu atoms. The striking structural feature is a [Pt{sub 6}] cluster in form of an empty trigonal prism at the origin of the unit cell, which is surrounded by coupled [BPt{sub 6}] and [Pt{sub 6}] trigonal prisms, rotated perpendicularly to the central one. There is no B–B contact as well as Cu–B contact in the structure. The relationships of Pt{sub 9}Cu{sub 3}B{sub 5} structure with the structure of Ti{sub 1+x}Os{sub 2−x}RuB{sub 2} as well as with the structure families of metal sulfides and aluminides have been elucidated. (Pt{sub 1–x}Cu{sub x}){sub 3}Cu{sub 2}B (x=0.3) (B-filled β-Mn-type structure) is a bulk superconductor with a transition temperature of about 2.06 K and an upper critical field μ{sub 0}H{sub C2}(0){sup WHH} of 1.2 T, whereas no superconducting transition has been observed up to 0.3 K in Pt{sub 9}Cu{sub 3}B{sub 5} (Pt{sub 9}Zn{sub 3}B{sub 5–δ}-type structure) from electrical resistivity measurements. - Highlights: • First two copper platinum borides, (Pt{sub 0.67}Cu{sub 0.33}){sub 3}Cu{sub 2}B and Pt{sub 9}Cu{sub 3}B{sub 5} were obtained. • (Pt{sub 0.67}Cu{sub 0.33}){sub 3}Cu{sub 2}B forms a B-filled β-Mn-type structure. • Pt{sub 9}Cu{sub 3}B{sub 5} adopts a Pt{sub 9}Zn{sub 3}B{sub 5–δ}-type structure. • Boron atoms exhibit octahedral and trigonal prismatic coordination. • (Pt{sub 1–x}Cu{sub x})3Cu{sub 2}B (x=0.3) is a bulk superconductor with T{sub c} 2.06 K.« less

Critical Role of the Src Homology 2 (SH2) Domain of Neuronal SH2B1 in the Regulation of Body Weight and Glucose Homeostasis in Mice

PubMed Central

Morris, David L.; Cho, Kae Won; Rui, Liangyou

2010-01-01

SH2B1 is an SH2 domain-containing adaptor protein that plays a key role in the regulation of energy and glucose metabolism in both rodents and humans. Genetic deletion of SH2B1 in mice results in obesity and type 2 diabetes. Single-nucleotide polymorphisms in the SH2B1 loci and chromosomal deletions of the SH2B1 loci associate with obesity and insulin resistance in humans. In cultured cells, SH2B1 promotes leptin and insulin signaling by binding via its SH2 domain to phosphorylated tyrosines in Janus kinase 2 and the insulin receptor, respectively. Here we generated three lines of mice to analyze the role of the SH2 domain of SH2B1 in the central nervous system. Transgenic mice expressing wild-type, SH2 domain-defective (R555E), or SH2 domain-alone (ΔN503) forms of SH2B1 specifically in neurons were crossed with SH2B1 knockout mice to generate KO/SH2B1, KO/R555E, or KO/ΔN503 compound mutant mice. R555E had a replacement of Arg555 with Glu within the SH2 domain. ΔN503 contained an intact SH2 domain but lacked amino acids 1-503. Neuron-specific expression of recombinant SH2B1, but not R555E or ΔN503, corrected hyperphagia, obesity, glucose intolerance, and insulin resistance in SH2B1 null mice. Neuron-specific expression of R555E in wild-type mice promoted obesity and insulin resistance. These results indicate that in addition to the SH2 domain, N-terminal regions of neuronal SH2B1 are also required for the maintenance of normal body weight and glucose metabolism. Additionally, mutations in the SH2 domain of SH2B1 may increase the susceptibility to obesity and type 2 diabetes in a dominant-negative manner. PMID:20484460

Critical role of the Src homology 2 (SH2) domain of neuronal SH2B1 in the regulation of body weight and glucose homeostasis in mice.

PubMed

Morris, David L; Cho, Kae Won; Rui, Liangyou

2010-08-01

SH2B1 is an SH2 domain-containing adaptor protein that plays a key role in the regulation of energy and glucose metabolism in both rodents and humans. Genetic deletion of SH2B1 in mice results in obesity and type 2 diabetes. Single-nucleotide polymorphisms in the SH2B1 loci and chromosomal deletions of the SH2B1 loci associate with obesity and insulin resistance in humans. In cultured cells, SH2B1 promotes leptin and insulin signaling by binding via its SH2 domain to phosphorylated tyrosines in Janus kinase 2 and the insulin receptor, respectively. Here we generated three lines of mice to analyze the role of the SH2 domain of SH2B1 in the central nervous system. Transgenic mice expressing wild-type, SH2 domain-defective (R555E), or SH2 domain-alone (DeltaN503) forms of SH2B1 specifically in neurons were crossed with SH2B1 knockout mice to generate KO/SH2B1, KO/R555E, or KO/DeltaN503 compound mutant mice. R555E had a replacement of Arg(555) with Glu within the SH2 domain. DeltaN503 contained an intact SH2 domain but lacked amino acids 1-503. Neuron-specific expression of recombinant SH2B1, but not R555E or DeltaN503, corrected hyperphagia, obesity, glucose intolerance, and insulin resistance in SH2B1 null mice. Neuron-specific expression of R555E in wild-type mice promoted obesity and insulin resistance. These results indicate that in addition to the SH2 domain, N-terminal regions of neuronal SH2B1 are also required for the maintenance of normal body weight and glucose metabolism. Additionally, mutations in the SH2 domain of SH2B1 may increase the susceptibility to obesity and type 2 diabetes in a dominant-negative manner.

Collection and Testing of Respiratory Samples

ClinicalTrials.gov

2017-04-03

QIAGEN ResPlex II Advanced Panel; Influenza A; Respiratory Syncytial Virus Infections; Infection Due to Human Parainfluenza Virus 1; Parainfluenza Type 2; Parainfluenza Type 3; Parainfluenza Type 4; Human Metapneumovirus A/B; Rhinovirus; Coxsackie Virus/Echovirus; Adenovirus Types B/C/E; Coronavirus Subtypes 229E; Coronavirus Subtype NL63; Coronavirus Subtype OC43; Coronavirus Subtype HKU1; Human Bocavirus; Artus Influenza A/B RT-PCR Test; Influenza B

Typing Discrepancy Between Phenotypic and Molecular Characterization Revealing an Emerging Biovar 9 Variant of Smooth Phage-Resistant B. abortus Strain 8416 in China.

PubMed

Kang, Yao-Xia; Li, Xu-Ming; Piao, Dong-Ri; Tian, Guo-Zhong; Jiang, Hai; Jia, En-Hou; Lin, Liang; Cui, Bu-Yun; Chang, Yung-Fu; Guo, Xiao-Kui; Zhu, Yong-Zhang

2015-01-01

A newly isolated smooth colony morphology phage-resistant strain 8416 isolated from a 45-year-old cattle farm cleaner with clinical features of brucellosis in China was reported. The most unusual phenotype was its resistance to two Brucella phages Tbilisi and Weybridge, but sensitive to Berkeley 2, a pattern similar to that of Brucella melitensis biovar 1. VITEK 2 biochemical identification system found that both strain 8416 and B. melitensis strains shared positive ILATk, but negative in other B. abortus strains. However, routine biochemical and phenotypic characteristics of strain 8416 were most similar to that of B. abortus biovar 9 except CO2 requirement. In addition, multiple PCR molecular typing assays including AMOS-PCR, B. abortus special PCR (B-ab PCR) and a novel sub-biovar typing PCR, indicated that strain 8416 may belong to either biovar 3b or 9 of B. abortus. Surprisingly, further MLVA typing results showed that strain 8416 was most closely related to B. abortus biovar 3 in the Brucella MLVA database, primarily differing in 4 out of 16 screened loci. Therefore, due to the unusual discrepancy between phenotypic (biochemical reactions and particular phage lysis profile) and molecular typing characteristics, strain 8416 could not be exactly classified to any of the existing B. abortus biovars and might be a new variant of B. abortus biovar 9. The present study also indicates that the present phage typing scheme for Brucella sp. is subject to variation and the routine Brucella biovar typing needs further studies.

Stable cavitation induces increased cytoplasmic calcium in L929 fibroblasts exposed to 1-MHz pulsed ultrasound.

PubMed

Tsukamoto, Akira; Higashiyama, Satoru; Yoshida, Kenji; Watanabe, Yoshiaki; Furukawa, Katsuko S; Ushida, Takashi

2011-12-01

An increase in cytoplasmic calcium (Ca(2+) increase) is a second messenger that is often observed under ultrasound irradiation. We hypothesize that cavitation is a physical mechanism that underlies the increase in Ca(2+) in these experiments. To control the presence of cavitation, the wave type was controlled in a sonication chamber. One wave type largely contained a traveling wave (wave type A) while the other wave type largely contained a standing wave (wave type B). Fast Fourier transform (FFT) analysis of a sound field produced by the wave types ascertained that stable cavitation was present only under wave type A ultrasound irradiation. Under the two controlled wave types, the increase in Ca(2+) in L929 fibroblasts was observed with fluorescence imaging. Under wave type A ultrasound irradiation, an increase in Ca(2+) was observed; however, no increase in Ca(2+) was observed under wave type B ultrasound irradiation. We conclude that stable cavitation is involved in the increase of Ca(2+) in cells subjected to pulsed ultrasound. Copyright © 2011 Elsevier B.V. All rights reserved.

Surface passivation of n-type doped black silicon by atomic-layer-deposited SiO2/Al2O3 stacks

NASA Astrophysics Data System (ADS)

van de Loo, B. W. H.; Ingenito, A.; Verheijen, M. A.; Isabella, O.; Zeman, M.; Kessels, W. M. M.

2017-06-01

Black silicon (b-Si) nanotextures can significantly enhance the light absorption of crystalline silicon solar cells. Nevertheless, for a successful application of b-Si textures in industrially relevant solar cell architectures, it is imperative that charge-carrier recombination at particularly highly n-type doped black Si surfaces is further suppressed. In this work, this issue is addressed through systematically studying lowly and highly doped b-Si surfaces, which are passivated by atomic-layer-deposited Al2O3 films or SiO2/Al2O3 stacks. In lowly doped b-Si textures, a very low surface recombination prefactor of 16 fA/cm2 was found after surface passivation by Al2O3. The excellent passivation was achieved after a dedicated wet-chemical treatment prior to surface passivation, which removed structural defects which resided below the b-Si surface. On highly n-type doped b-Si, the SiO2/Al2O3 stacks result in a considerable improvement in surface passivation compared to the Al2O3 single layers. The atomic-layer-deposited SiO2/Al2O3 stacks therefore provide a low-temperature, industrially viable passivation method, enabling the application of highly n- type doped b-Si nanotextures in industrial silicon solar cells.

Ultraviolet photometry from the orbiting astronomical observatory. XVI - The stellar Lyman-alpha absorption line

NASA Technical Reports Server (NTRS)

Savage, B. D.; Panek, R. J.

1974-01-01

The stellar Lyman-alpha line at 1216 A was observed in 29 lightly reddened stars of spectral type B2.5 to B9 by a far-UV spectrophotometer on OAO-2. The equivalent widths obtained range from 15 A at type B2.5 to 65 A at type B8; in the late-B stars, the L-alpha line removes 2 to 3% of the total stellar flux. In this sampling, the strength of the L-alpha line correlates well with measures of the Balmer discontinuity and Balmer line strengths; luminosity classification does not seem to affect the line strength. The observed line widths also agree with the predictions of Mihala's grid of non-LTE model atmospheres. In some cases, the L-alpha line influences the interstellar column densities reported in the interstellar OAO-2 L-alpha survey. Hence, these data toward lightly reddened B2 and B1.5 stars should be regarded as upper limits only.

MLVA and MLST typing of Brucella from Qinghai, China.

PubMed

Ma, Jun-Ying; Wang, Hu; Zhang, Xue-Fei; Xu, Li-Qing; Hu, Gui-Ying; Jiang, Hai; Zhao, Fang; Zhao, Hong-Yan; Piao, Dong-Ri; Qin, Yu-Min; Cui, Bu-Yun; Lin, Gong-Hua

2016-04-13

The Qinghai-Tibet Plateau (QTP) of China is an extensive pastoral and semi-pastoral area, and because of poverty and bad hygiene conditions, Brucella is highly prevalent in this region. In order to adequately prevent this disease in the QTP region it is important to determine the identity of Brucella species that caused the infection. A total of 65 Brucella isolates were obtained from human, livestock and wild animals in Qinghai, a Chinese province in east of the QTP. Two molecular typing methods, MLVA (multi-locus variable-number tandem-repeat analysis) and MLST (multi locus sequence typing) were used to identify the species and genotypes of these isolates. Both MLVA and MLST typing methods classified the 65 isolates into three species, B. melitensis, B. abortus and B. suis, which included 60, 4 and 1 isolates respectively. The MLVA method uniquely detected 34 (Bm01 ~ Bm34), 3 (Ba01 ~ Ba03), and 1 (Bs01) MLVA-16 genotypes for B. melitensis, B. abortus and B. suis, respectively. However, none of these genotypes exactly matched any of the genotypes in the Brucella2012 MLVA database. The MLST method identified five known ST types: ST7 and ST8 (B. melitensis), ST2 and ST5 (B. abortus), and ST14 (B. suis). We also detected a strain with a mutant type (3-2-3-2-?-5-3-8-2) of ST8 (3-2-3-2-1-5-3-8-2). Extensive genotype-sharing events could be observed among isolates from different host species. There were at least three Brucella (B. melitensis, B. abortus and B. suis) species in Qinghai, of which B. melitensis was the predominant species in the area examined. The Brucella population in Qinghai was very different from other regions of the world, possibly owing to the unique geographical characteristics such as extremely high altitude in QTP. There were extensive genotype-sharing events between isolates obtained from humans and other animals. Yaks, sheep and blue sheep were important zoonotic reservoirs of brucellosis causing species found in humans.

(Pt1-xCux)3Cu2B and Pt9Cu3B5, the first examples of copper platinum borides. Observation of superconductivity in a novel boron filled β-Mn-type compound

NASA Astrophysics Data System (ADS)

Salamakha, Leonid P.; Sologub, Oksana; Stöger, Berthold; Michor, Herwig; Bauer, Ernst; Rogl, Peter F.

2015-09-01

New ternary copper platinum borides have been synthesized by arc melting of pure elements followed by annealing at 600 °C. The structures have been studied by X-ray single crystal and powder diffraction. (Pt1-xCux)3Cu2B (x=0.33) forms a B-filled β-Mn-type structure (space group P4132; a=0.6671(1) nm). Cu atoms are distributed preferentially on the 8c atom sites, whereas the 12d site is randomly occupied by Pt and Cu atoms (0.670(4) Pt±0.330(4) Cu). Boron is located in octahedral voids of the parent β-Mn-type structure. Pt9Cu3B5 (space group P-62m; a=0.9048(3) nm, c=0.2908(1) nm) adopts the Pt9Zn3B5-δ-type structure. It has a columnar architecture along the short translation vector exhibiting three kinds of [Pt6] trigonal prism columns (boron filled, boron semi-filled and empty) and Pt channels with a pentagonal cross section filled with Cu atoms. The striking structural feature is a [Pt6] cluster in form of an empty trigonal prism at the origin of the unit cell, which is surrounded by coupled [BPt6] and [Pt6] trigonal prisms, rotated perpendicularly to the central one. There is no B-B contact as well as Cu-B contact in the structure. The relationships of Pt9Cu3B5 structure with the structure of Ti1+xOs2-xRuB2 as well as with the structure families of metal sulfides and aluminides have been elucidated. (Pt1-xCux)3Cu2B (x=0.3) (B-filled β-Mn-type structure) is a bulk superconductor with a transition temperature of about 2.06 K and an upper critical field μ0HC2(0)WHH of 1.2 T, whereas no superconducting transition has been observed up to 0.3 K in Pt9Cu3B5 (Pt9Zn3B5-δ-type structure) from electrical resistivity measurements.

[Effect of 2-deoxy-d-glucose on enterovirus reproduction in HEp-2 cell cultures].

PubMed

Shirobokov, V P

1976-01-01

The influence of 2-deoxy-d-glucose (2DG) on reproduction of some enteroviruses was studied. When 2DG was added to carbohydrate-free medium. It exerted a marked inhibiting effect on reproduction of poliovirus type I (virulent and attenuated variants) and Coxsackie B1, B2, B3, B5 and B6 viruses. The agent was inactive for virulent and attenuated poliomyelitis type II viruses. Poliomyelitis type III and Coxsackie B4 viruses were shown to be incable of multiplication in carbohydrate-free medium when the maintenance medium in cell cultures was lactalbumin hydrolysate in Hank's solution without-glucose. The inhibiting effect of 2DG on sensitive enteroviruses was irreversible and manifest at a concentration as low as 0.1 mg/ml. The effect of the agent was directed to the active stages of intracellular enterovirus synthesis. The possible mechanism of inhibition of enterovirus reproduction in the presence of 2DG is discussed.

Diabetes area participation analysis: a review of companies and targets described in the 2008 - 2010 patent literature.

PubMed

Carpino, Philip A; Goodwin, Bryan

2010-12-01

Type 2 diabetes is a chronic disease characterized by the development of insulin resistance, impaired pancreatic β-cell function and, ultimately, hyperglycemia. The disease is highly associated with obesity and it is thought that the inappropriate deposition of lipid in tissues such as liver and muscle contributes to a reduction in insulin sensitivity which, in turn, places a burden on the β-cell to secrete more insulin to achieve normoglycemia. Over an extended period of time, this can result in β-cell failure and diminished glycemic control. When poorly managed, type 2 diabetes increases the risk of developing both microvascular and macrovascular complications, including retinopathy, nephropathy and coronary artery disease. The number of Americans with diabetes has approached 24 million in 2007 and the prevalence of the disease is projected to increase with the sedentary lifestyles and high caloric diets that are common today. First-line treatment for the disease involves lifestyle modifications and, if unsuccessful, pharmacotherapy to control symptoms. Anti-diabetic drugs belonging to several mechanistic classes are available (e.g., insulin secretagogues, insulin sensitizers, insulin mimetics and DPP IV inhibitors); however, many of these drugs lose their effectiveness over time, are not well-tolerated in some patients or may have suboptimal risk:benefit ratios. The search for new anti-diabetic drugs has continued to attract considerable interest from both academia and the pharmaceutical industry. An analysis of 2008 - 2010 patent applications claiming diabetes as an indication has been undertaken. An understanding of: i) the pharmaceutical companies that have filed patent applications in the anti-diabetes area during 2008 - 2010; ii) the different pharmacological targets under investigation and the patent activity around such targets; iii) some of the targets in the research portfolios of selected companies; iv) chemical structures of compounds that modulate emerging targets and v) the pharmacological rationale underlying several targets with the largest patent counts. Type 2 diabetes is a complex disease with many potential points of intervention for pharmacotherapy. A majority of anti-diabetic patent applications claim chemical matter for just eight targets which include five enzymes, a GPCR, a family of nuclear hormone receptors and a class of sodium-dependent glucose co-transporters (11β-HSD1, DGAT1, DPP IV, glucokinase, GPR119, PPAR-α, -δ, -γ, SGLT1 and SGLT2, and stearoyl-CoA desaturase 1 (SCD1)). The major pharmaceutical companies are all pursuing some combination of these top eight targets. Several companies stand out for the breadth of new targets under investigation (e.g., F. Hoffmann-La Roche, Merck & Co., Pfizer, Takeda Pharmaceuticals, Sanofi-Aventis).

Canine Parvovirus Types 2c and 2b Circulating in North American Dogs in 2006 and 2007▿

PubMed Central

Kapil, Sanjay; Cooper, Emily; Lamm, Cathy; Murray, Brandy; Rezabek, Grant; Johnston, Larry; Campbell, Gregory; Johnson, Bill

2007-01-01

Parvovirus is the most common viral cause of diarrhea in young puppies. Based on the analysis of a partial VP2 sequence of 54 samples, canine parvovirus type 2c (CPV-2c) (n = 26), CPV-2b (n = 25), and CPV-2 (n = 3) were detected in the United States. The American CPV-2b isolates have unique codons (494 and 572) in VP2. PMID:17928423

Functional characterization of type-B response regulators in the Arabidopsis cytokinin response.

PubMed

Hill, Kristine; Mathews, Dennis E; Kim, Hyo Jung; Street, Ian H; Wildes, Sarah L; Chiang, Yi-Hsuan; Mason, Michael G; Alonso, Jose M; Ecker, Joseph R; Kieber, Joseph J; Schaller, G Eric

2013-05-01

Cytokinins play critical roles in plant growth and development, with the transcriptional response to cytokinin being mediated by the type-B response regulators. In Arabidopsis (Arabidopsis thaliana), type-B response regulators (ARABIDOPSIS RESPONSE REGULATORS [ARRs]) form three subfamilies based on phylogenic analysis, with subfamily 1 having seven members and subfamilies 2 and 3 each having two members. Cytokinin responses are predominantly mediated by subfamily 1 members, with cytokinin-mediated effects on root growth and root meristem size correlating with type-B ARR expression levels. To determine which type-B ARRs can functionally substitute for the subfamily 1 members ARR1 or ARR12, we expressed different type-B ARRs from the ARR1 promoter and assayed their ability to rescue arr1 arr12 double mutant phenotypes. ARR1, as well as a subset of other subfamily 1 type-B ARRs, restore the cytokinin sensitivity to arr1 arr12. Expression of ARR10 from the ARR1 promoter results in cytokinin hypersensitivity and enhances shoot regeneration from callus tissue, correlating with enhanced stability of the ARR10 protein compared with the ARR1 protein. Examination of transfer DNA insertion mutants in subfamilies 2 and 3 revealed little effect on several well-characterized cytokinin responses. However, a member of subfamily 2, ARR21, restores cytokinin sensitivity to arr1 arr12 roots when expressed from the ARR1 promoter, indicating functional conservation of this divergent family member. Our results indicate that the type-B ARRs have diverged in function, such that some, but not all, can complement the arr1 arr12 mutant. In addition, our results indicate that type-B ARR expression profiles in the plant, along with posttranscriptional regulation, play significant roles in modulating their contribution to cytokinin signaling.

B cell function in the immune response to helminths

PubMed Central

Harris, Nicola

2010-01-01

Similar T helper (Th)2-type immune responses are generated against different helminths parasites, but the mechanisms that initiate Th2 immunity, and the specific immune components that mediate protection against these parasites, can vary greatly. B cells are increasingly recognized as important during the Th2-type immune response to helminths, and B cell activation might be a target for effective vaccine development. Antibody production is a function of B cells during helminth infection and understanding how polyclonal and antigen-specific antibodies contribute should provide important insights into how protective immunity develops. In addition, B cells might also contribute to the host response against helminths through antibody-independent functions including, antigen-presentation, as well as regulatory and effector activity. In this review, we examine the role of B cells during Th2-type immune response to these multicellular parasites. PMID:21159556

First in-depth analysis of the novel Th2-type cytokines in salmonid fish reveals distinct patterns of expression and modulation but overlapping bioactivities

PubMed Central

Wang, Tiehui; Johansson, Petronella; Abós, Beatriz; Holt, Amy; Tafalla, Carolina; Jiang, Youshen; Wang, Alex; Xu, Qiaoqing; Qi, Zhitao; Huang, Wenshu; Costa, Maria M.; Diaz-Rosales, Patricia; Holland, Jason W.; Secombes, Christopher J.

2016-01-01

IL-4 and IL-13 are closely related canonical type-2 cytokines in mammals and have overlapping bioactivities via shared receptors. They are frequently activated together as part of the same immune response and are the signature cytokines produced by T-helper (Th)2 cells and type-2 innate lymphoid cells (ILC2), mediating immunity against extracellular pathogens. Little is known about the origin of type-2 responses, and whether they were an essential component of the early adaptive immune system that gave a fitness advantage by limiting collateral damage caused by metazoan parasites. Two evolutionary related type-2 cytokines, IL-4/13A and IL-4/13B, have been identified recently in several teleost fish that likely arose by duplication of an ancestral IL-4/13 gene as a consequence of a whole genome duplication event that occurred at the base of this lineage. However, studies of their comparative expression levels are largely missing and bioactivity analysis has been limited to IL-4/13A in zebrafish. Through interrogation of the recently released salmonid genomes, species in which an additional whole genome duplication event has occurred, four genomic IL-4/13 loci have been identified leading to the cloning of three active genes, IL-4/13A, IL-4/13B1 and IL-4/13B2, in both rainbow trout and Atlantic salmon. Comparative expression analysis by real-time PCR in rainbow trout revealed that the IL-4/13A expression is broad and high constitutively but less responsive to pathogen-associated molecular patterns (PAMPs) and pathogen challenge. In contrast, the expression of IL-4/13B1 and IL-4/13B2 is low constitutively but is highly induced by viral haemorrhagic septicaemia virus (VHSH) infection and during proliferative kidney disease (PKD) in vivo, and by formalin-killed bacteria, PAMPs, the T cell mitogen PHA, and the T-cell cytokines IL-2 and IL-21 in vitro. Moreover, bioactive recombinant cytokines of both IL-4/13A and B were produced and found to have shared but also distinct bioactivities. Both cytokines rapidly induce the gene expression of antimicrobial peptides and acute phase proteins, providing an effector mechanism of fish type-2 cytokines in immunity. They are anti-inflammatory via up-regulation of IL-10 and down-regulation of IL-1β and IFN-γ. They modulate the expression of cellular markers of T cells, macrophages and B cells, the receptors of IFN-γ, the IL-6 cytokine family and their own potential receptors, suggesting multiple target cells and important roles of fish type-2 cytokines in the piscine cytokine network. Furthermore both cytokines increased the number of IgM secreting B cells but had no effects on the proliferation of IgM+ B cells in vitro. Taken as a whole, fish IL-4/13A may provide a basal level of type-2 immunity whilst IL-4/13B, when activated, provides an enhanced type-2 immunity, which may have an important role in specific cell-mediated immunity. To our knowledge this is the first in-depth analysis of the expression, modulation and bioactivities of type-2 cytokines in the same fish species, and in any early vertebrate. It contributes to a broader understanding of the evolution of type-2 immunity in vertebrates, and establishes a framework for further studies and manipulation of type-2 cytokines in fish. PMID:26870894

A facile synthesis of pyrrolo[2,3-b]quinolines via a Rh(I)-catalyzed carbodiimide-Pauson-Khand-type reaction.

PubMed

Saito, Takao; Furukawa, Naoki; Otani, Takashi

2010-03-07

A new straightforward synthetic method for 2,3-dihydro-1H-pyrrolo[2,3-b]quinolin-2-ones via a [RhCl(CO)(2)](2)-dppp catalyzed Pauson-Khand-type reaction of N-[2-(2-alkyn-1-yl)phenyl]carbodiimides is reported.

Genomic typing of canine parvovirus circulating in the State of Rio de Janeiro, Brazil from 1995 to 2001 using polymerase chain reaction assay.

PubMed

Costa, A P; Leite, J P G; Labarthe, N V; Garcia, R C N Cubel

2005-11-01

In this study, the genomic types of canine parvovirus (CPV) circulating in the State of Rio de Janeiro, Brazil, from 1995 to 2001, were investigated using the polymerase chain reaction assay (PCR). A total of 78 faecal samples from gastroenteritic puppies, confirmed as positive for canine parvovirus by haemagglutination/haemagglutination inhibition tests or virus isolation in cell culture (MDCK), were examined. The viral DNA was extracted from faecal samples using a combination of phenol- chloroform and silica-guanidine thiocyanate methods. PCR was carried out with differential pairs of primers to distinguish the old (CPV-2) and new types of virus (CPv-2a or CPV-2b). Specific amplicons were observed for all samples using the primer pair P2ab, which detects CPV-2a and CPV-2b. Seventy-six from a total of 78 samples (97%) were considered as CPV-2b because of their reaction with the primer pair P2b. Thirty samples (30/78) were from previously vaccinated puppies and in 15 of them the enteritis symptoms began from 1 to 12 days after vaccination. PCR confirmed the infection by wild virus (CPV-2b) in 5 of these 15 puppies who had received old-type vaccines. Our results show that CPV-2b was the prevalent type circulating in the State of Rio de Janeiro from 1995 to 2001.

Effects of the Types of Error, Proficiency Level of the Learners and Nature of the Recasts on the Uptake of Learners

ERIC Educational Resources Information Center

Yuksel, Dogan; Inan-Karagul, Banu; Fidan, Dilek

2017-01-01

This current study examined the effects of the type of errors learners make (that is, phonological, lexical and grammar), proficiency level of the learners (that is, A1, A2, B1, B2 and C1) and nature of the recasts (that is, long and short) on the uptake of the learners. The data of this study came from the video-recordings of A1, A2, B1, B2 and…

Examination of Multiphase (Zr,Ti)(V,Cr,Mn,Ni)2 Ni-MH Electrode Alloys: Part II. Solid-State Transformation of the Interdendritic B2 Phase

NASA Astrophysics Data System (ADS)

Bendersky, L. A.; Wang, K.; Boettinger, W. J.; Newbury, D. E.; Young, K.; Chao, B.

2010-08-01

Solidification microstructure of multicomponent (Zr,Ti)-Ni-(V,Cr,Mn,Co) alloys intended for use as negative electrodes in Ni-metal hydride (Ni-MH) batteries was studied in Part I of this series of articles. Part II of the series examines the complex internal structure of the interdendritic grains formed by solid-state transformation and believed to play an important role in the electrochemical charge/discharge characteristics of the overall alloy composition. By studying one alloy, Zr21Ti12.5V10Cr5.5Mn5.1Co5.0Ni40.2Al0.5Sn0.3, it is shown that the interdendritic grains solidify as a B2 (Ti,Zr)44(Ni,TM)56 phase, and then undergo transformation to Zr7Ni10-type, Zr9Ni11-type, and martensitic phases. The transformations obey orientation relationships between the high-temperature B2 phase and the low-temperature Zr-Ni-type intermetallics, and consequently lead to a multivariant structure. The major orientation relationship for the orthorhombic Zr7Ni10 type is [011]Zr7Ni10//[001]B2; (100)Zr7Ni10//(100)B2. The orientation relationship for the tetragonal Zr9Ni11 type is [001]Zr9Ni11//[001]B2; (130)Zr9Ni11//(100)B2. Binary Ni-Zr and ternary Ti-Ni-Zr phase diagrams were used to rationalize the formation of the observed domain structure.

Role of Fyn-mediated NMDA receptor function in prediabetic neuropathy in mice

PubMed Central

Suo, Meng; Wang, Ping

2016-01-01

Diabetic neuropathy is a common complication of diabetes. This study evaluated the role of Fyn kinase and N-methyl-d-aspartate receptors (NMDARs) in the spinal cord in diabetic neuropathy using an animal model of high-fat diet-induced prediabetes. We found that prediabetic wild-type mice exhibited tactile allodynia and thermal hypoalgesia after a 16-wk high-fat diet, relative to normal diet-fed wild-type mice. Furthermore, prediabetic wild-type mice exhibited increased tactile allodynia and thermal hypoalgesia at 24 wk relative to 16 wk. Such phenomena were correlated with increased expression and activation of NR2B subunit of NMDARs, as well as Fyn-NR2B interaction in the spinal cord. Fyn−/− mice developed prediabetes after 16-wk high-fat diet treatment and exhibited thermal hypoalgesia, without showing tactile allodynia or altered expression and activation of NR2B subunit, relative to normal diet-fed Fyn−/− mice. Finally, intrathecal administrations of Ro 25-6981 (selective NR2B subunit-containing NMDAR antagonist) dose-dependently alleviated tactile allodynia, but not thermal hypoalgesia, at 16 and 24 wk in prediabetic wild-type mice. Our results suggested that Fyn-mediated NR2B signaling plays a critical role in regulation of prediabetic neuropathy and that the increased expression/function of NR2B subunit-containing NMDARs may contribute to the progression of neuropathy in type 2 diabetes. PMID:27146985

Pediatric obesity & type 2 diabetes.

PubMed

Dea, Tara L

2011-01-01

This article focuses on (a) identifying obesity and other risk factors for developing type 2 diabetes, (b) differentiating between pediatric type 1 diabetes and type 2 diabetes, and (c) treating pediatric type 2 diabetes. Obesity has significant implications on a child's health, including an increased risk for insulin resistance and progression to type 2 diabetes. Type 2 diabetes in children, characterized by insulin resistance and relative pancreatic b-cell failure due to the increased demand for insulin production, has now reached epidemic proportions. Longitudinal research on pediatric type 2 diabetes, however, is lacking because this epidemic is relatively new. Treatment of type 2 diabetes in children is focused on lifestyle modification with weight management/increased physical activity, and pharmacological management through oral medication or insulin therapy. Because children with type 2 diabetes are at risk for developing diabetes-related complications earlier in life, they need to be closely monitored for comorbidities.

A 12-year molecular survey of clinical herpes simplex virus type 2 isolates demonstrates the circulation of clade A and B strains in Germany.

PubMed

Schmidt-Chanasit, Jonas; Bialonski, Alexandra; Heinemann, Patrick; Ulrich, Rainer G; Günther, Stephan; Rabenau, Holger F; Doerr, Hans Wilhelm

2010-07-01

Recently two different herpes simplex virus type 2 (HSV-2) clades (A and B) were described on DNA sequence data of the glycoprotein E (gE), G (gG) and I (gI) genes. To type the circulating HSV-2 wild-type strains in Germany by a novel approach and to monitor potential changes in the molecular epidemiology between 1997 and 2008. A total of 64 clinical HSV-2 isolates were analyzed by a novel approach using the DNA sequences of the complete open reading frames of glycoprotein B (gB) and gG. Recombination analysis of the gB and gG gene sequences was performed to reveal intragenic recombinants. Based on the phylogenetic analysis of the gB coding DNA sequence 8 of 64 (12%) isolates were classified as clade A strains and 56 of 64 (88%) isolates were classified as clade B strains. Analysis of the gG coding DNA sequence classified 4 (6%) isolates as clade A strains and 60 (94%) isolates as clade B strains. In comparison, the 8 isolates classified as clade A strains using the gB sequence data were classified as clade B strains when using the gG coding DNA sequence, suggesting intergenic recombination events. Intragenic recombination events were not detected. The first molecular survey of clinical HSV-2 isolates from Germany demonstrated the circulation of clade A and B strains and of intergenic recombinants over a period of 12 years. Copyright (c) 2010 Elsevier B.V. All rights reserved.

TEM study of the martensitic phases in the ductile DyCu and YCu intermetallic compounds [The martensitic phase transformation in ductile DyCu and YCu intermetallic compounds

DOE PAGES

Cao, G. H.; Oertel, C. -G.; Schaarschuch, R.; ...

2017-05-03

DyCu and YCu are representatives of the family of CsCl-type B2 rare earth intermetallic compounds that exhibit high room temperature ductility. Structure, orientation relationship, and morphology of the martensites in the equiatomic compounds DyCu and YCu are examined using transmission electron microscopy (TEM). TEM studies show that the martensite structures in DyCu and YCu alloys are virtually identical. The martensite is of orthorhombic CrB-type B33 structure with lattice parameters a = 0.38 nm, b = 1.22 nm, and c = 0.40 nm. (021¯) twins were observed in the B33 DyCu and YCu martensites. The orientation relationship of B33 and B2more » phases is (111¯)[112]B33 || (110)[001]B2. The simulated electron diffraction patterns of the B33 phase are consistent with those of experimental observations. TEM investigations also reveal that a dominant orthorhombic FeB-type B27 martensite with lattice parameters a = 0.71 nm, b = 0.45 nm, and c = 0.54 nm exists in YCu alloy. (11¯ 1) twins were observed in the B27 YCu martensite. As a result, the formation mechanism of B2 to B33 and B2 to B27 phase transformation is discussed.« less

A One-Step Immunostaining Method to Visualize Rodent Muscle Fiber Type within a Single Specimen

PubMed Central

Sawano, Shoko; Komiya, Yusuke; Ichitsubo, Riho; Ohkawa, Yasuyuki; Nakamura, Mako; Tatsumi, Ryuichi; Ikeuchi, Yoshihide; Mizunoya, Wataru

2016-01-01

In this study, we present a quadruple immunostaining method for rapid muscle fiber typing of mice and rats using antibodies specific to the adult myosin heavy chain (MyHC) isoforms MyHC1, 2A, 2X, and 2B, which are common marker proteins of distinct muscle fiber types. We developed rat monoclonal antibodies specific to each MyHC isoform and conjugated these four antibodies to fluorophores with distinct excitation and emission wavelengths. By mixing the four types of conjugated antibodies, MyHC1, 2A, 2X, and 2B could be distinguished within a single specimen allowing for facile delineation of skeletal muscle fiber types. Furthermore, we could observe hybrid fibers expressing MyHC2X and MyHC2B together in single longitudinal muscle sections from mice and rats, that was not attained in previous techniques. This staining method is expected to be applied to study muscle fiber type transition in response to environmental factors, and to ultimately develop techniques to regulate animal muscle fiber types. PMID:27814384

Cell type-specific localization of Ephs pairing with ephrin-B2 in the rat postnatal pituitary gland.

PubMed

Yoshida, Saishu; Kato, Takako; Kanno, Naoko; Nishimura, Naoto; Nishihara, Hiroto; Horiguchi, Kotaro; Kato, Yukio

2017-10-01

Sox2-expressing stem/progenitor cells in the anterior lobe of the pituitary gland form two types of micro-environments (niches): the marginal cell layer and dense cell clusters in the parenchyma. In relation to the mechanism of regulation of niches, juxtacrine signaling via ephrin and its receptor Eph is known to play important roles in various niches. The ephrin and Eph families are divided into two subclasses to create ephrin/Eph signaling in co-operation with confined partners. Recently, we reported that ephrin-B2 localizes specifically to both pituitary niches. However, the Ephs interacting with ephrin-B2 in these pituitary niches have not yet been identified. Therefore, the present study aims to identify the Ephs interacting with ephrin-B2 and the cells that produce them in the rat pituitary gland. In situ hybridization and immunohistochemistry demonstrated cell type-specific localization of candidate interacting partners for ephrin-B2, including EphA4 in cells located in the posterior lobe, EphB1 in gonadotropes, EphB2 in corticotropes, EphB3 in stem/progenitor cells and EphB4 in endothelial cells in the adult pituitary gland. In particular, double-immunohistochemistry showed cis-interactions between EphB3 and ephrin-B2 in the apical cell membranes of stem/progenitor cell niches throughout life and trans-interactions between EphB2 produced by corticotropes and ephrin-B2 located in the basolateral cell membranes of stem/progenitor cells in the early postnatal pituitary gland. These data indicate that ephrin-B2 plays a role in pituitary stem/progenitor cell niches by selective interaction with EphB3 in cis and EphB2 in trans.

Novel type of VanB2 teicoplanin-resistant hospital-associated Enterococcus faecium.

PubMed

Santona, Antonella; Paglietti, Bianca; Al-Qahtani, Ahmed A; Bohol, Marie Fe F; Senok, Abiola; Deligios, Massimo; Rubino, Salvatore; Al-Ahdal, Mohammed N

2014-08-01

Seven high-risk clones of vancomycin-resistant Enterococcus faecium (VREF) belonging to clonal complex 17 were identified using multilocus sequence typing (MLST) among clinical isolates from Saudi Arabia. Among these isolates, a new hospital-associated sequence type (ST795), VanB(2)-type teicoplanin-resistant strain was detected. Its unusual phenotype resulted from a new combination of mutations in the ddl, vanS and vanW genes, which confirmed the trend of evolution in VanB-type resistance. Furthermore, characteristics of adaptation and persistence in the hospital environment of ST795 were emphasised by the presence of genes and clusters recognised to be specific for hospital-associated VREF. Copyright © 2014 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

Phase stability, crystal structure and magnetism in (U1-xNbx)2 Ni21B6 and (UyNb1-y)3Ni20B6

NASA Astrophysics Data System (ADS)

Provino, Alessia; Bhattacharya, Amitava; Dhar, Sudesh K.; Pani, Marcella; Gatti, Flavio; Paudyal, Durga; Manfrinetti, Pietro

Ternary phases with composition T2M21X6 and T3M20X6 (T = transition metal; M = 3 d metal; X = B, C, P) are reported to crystallize with the W2Cr21C6-type and Mg3Ni20B6-type, respectively (ternary ordered derivatives of the cubic Cr23C6-type, cF116). They attract interest due to their refractory, mechanical, and peculiar magnetic properties. Literature data on these compounds only concern apparently stoichiometric 2:21:6 and 3:20:6 phases. Often only nominal composition has been reported, with few structural refinements and no measurements of physical properties. Lack of detailed stoichiometry and crystallographic data does not allow sufficient understanding of the crystal chemistry and properties of these compounds. We studied stability, crystal structure and magnetism of (U1-xNbx)2 Ni21B6 and (UyNb1-y)3Ni20B6; stable phases are U2Ni21B6 and Nb3Ni20B6, as also confirmed by theoretical calculations. The two pristine compounds solubilize Nb and U, respectively, up to a given extent. The substitution of U by Nb leads to a structural change from the W2Cr21C6- to the Mg3Ni20B6-type. While U2Ni21B6 is a Pauli paramagnet (itinerant non-magnetic state of U-5 f electrons), in agreement with literature, magnetization data for (UyNb1-y)3 Ni20B6 show itinerant ferromagnetism with TC >300 K.

Negative effect of rapidly resorbing properties of bioactive glass-ceramics as bone graft substitute in a rabbit lumbar fusion model.

PubMed

Lee, Jae Hyup; Ryu, Hyun-Seung; Seo, Jun-Hyuk; Lee, Do-Yoon; Chang, Bong-Soon; Lee, Choon-Ki

2014-03-01

Bioactive glass-ceramics have the ability to directly bind to bones and have been widely used as bone graft substitutes due to their high osteoconductivity and biocompatibility. CaO-SiO2-P2O5-B2O3 glass-ceramics are known to have good osteoconductivity and are used as bone graft extenders. This study aimed to evaluate the effects of the resorbing properties of glass-ceramics in bone fusion after producing and analyzing three types of CaO-SiO2-P2O5-B2O3 glass-ceramics with high osteoconductivity that had enhanced resorption by having an increased B2O3 content. The three types of CaO-SiO2-P2O5-B2O3 glass-ceramics with B2O3 contents of 8.0, 9.0, and 9.5 weight % were designated and grouped as P20B80, P10B90, and P5B95, respectively. Glass-ceramic types were tested for fusion rates and bone formation by employing the lumbar 5-6 intertransverse process fusion model in 51 New Zealand male rabbits. Bioactivity was assessed by soaking in simulated body fluid (SBF). In vitro study results showed sufficient hydroxycarbonate apatite layer formation occurred for P20B80 in1 day, for P10B90 in 3 days, and for P5B95 in 5 days after soaking in SBF. For the rabbit lumbar spine posterolateral fusion model, the autograft group recorded a 100% fusion rate with levels significantly higher than those of P20B80 (29.4%), P10B90 (0%), and P5B95 (14.3%), with high resorbing properties. Resorbing property differences among the three glass-ceramic groups were not significant. Histological results showed new bone formation confirming osteoconductivity in all three types of glass-ceramics. Radiomorphometric results also confirmed the resorbing properties of the three glass-ceramic types. The high resorbing properties and osteoconductivity of porous glass-ceramics can be advantageous as no glass-ceramics remain in the body. However, their relatively fast rate of resorption in the body negatively affects their role as an osteoconductive scaffold as glass-ceramics are resorbed before bony fusion.

Negative Effect of Rapidly Resorbing Properties of Bioactive Glass-Ceramics as Bone Graft Substitute in a Rabbit Lumbar Fusion Model

PubMed Central

Lee, Jae Hyup; Ryu, Hyun-Seung; Seo, Jun-Hyuk; Lee, Do-Yoon; Chang, Bong-Soon

2014-01-01

Background Bioactive glass-ceramics have the ability to directly bind to bones and have been widely used as bone graft substitutes due to their high osteoconductivity and biocompatibility. CaO-SiO2-P2O5-B2O3 glass-ceramics are known to have good osteoconductivity and are used as bone graft extenders. Methods This study aimed to evaluate the effects of the resorbing properties of glass-ceramics in bone fusion after producing and analyzing three types of CaO-SiO2-P2O5-B2O3 glass-ceramics with high osteoconductivity that had enhanced resorption by having an increased B2O3 content. The three types of CaO-SiO2-P2O5-B2O3 glass-ceramics with B2O3 contents of 8.0, 9.0, and 9.5 weight % were designated and grouped as P20B80, P10B90, and P5B95, respectively. Glass-ceramic types were tested for fusion rates and bone formation by employing the lumbar 5-6 intertransverse process fusion model in 51 New Zealand male rabbits. Bioactivity was assessed by soaking in simulated body fluid (SBF). Results In vitro study results showed sufficient hydroxycarbonate apatite layer formation occurred for P20B80 in1 day, for P10B90 in 3 days, and for P5B95 in 5 days after soaking in SBF. For the rabbit lumbar spine posterolateral fusion model, the autograft group recorded a 100% fusion rate with levels significantly higher than those of P20B80 (29.4%), P10B90 (0%), and P5B95 (14.3%), with high resorbing properties. Resorbing property differences among the three glass-ceramic groups were not significant. Histological results showed new bone formation confirming osteoconductivity in all three types of glass-ceramics. Radiomorphometric results also confirmed the resorbing properties of the three glass-ceramic types. Conclusions The high resorbing properties and osteoconductivity of porous glass-ceramics can be advantageous as no glass-ceramics remain in the body. However, their relatively fast rate of resorption in the body negatively affects their role as an osteoconductive scaffold as glass-ceramics are resorbed before bony fusion. PMID:24605194

Diversity of Group I and II Clostridium botulinum Strains from France Including Recently Identified Subtypes.

PubMed

Mazuet, Christelle; Legeay, Christine; Sautereau, Jean; Ma, Laurence; Bouchier, Christiane; Bouvet, Philippe; Popoff, Michel R

2016-06-13

In France, human botulism is mainly food-borne intoxication, whereas infant botulism is rare. A total of 99 group I and II Clostridium botulinum strains including 59 type A (12 historical isolates [1947-1961], 43 from France [1986-2013], 3 from other countries, and 1 collection strain), 31 type B (3 historical, 23 recent isolates, 4 from other countries, and 1 collection strain), and 9 type E (5 historical, 3 isolates, and 1 collection strain) were investigated by botulinum locus gene sequencing and multilocus sequence typing analysis. Historical C. botulinum A strains mainly belonged to subtype A1 and sequence type (ST) 1, whereas recent strains exhibited a wide genetic diversity: subtype A1 in orfX or ha locus, A1(B), A1(F), A2, A2b2, A5(B2') A5(B3'), as well as the recently identified A7 and A8 subtypes, and were distributed into 25 STs. Clostridium botulinum A1(B) was the most frequent subtype from food-borne botulism and food. Group I C. botulinum type B in France were mainly subtype B2 (14 out of 20 historical and recent strains) and were divided into 19 STs. Food-borne botulism resulting from ham consumption during the recent period was due to group II C. botulinum B4. Type E botulism is rare in France, 5 historical and 1 recent strains were subtype E3. A subtype E12 was recently identified from an unusual ham contamination. Clostridium botulinum strains from human botulism in France showed a wide genetic diversity and seems to result not from a single evolutionary lineage but from multiple and independent genetic rearrangements. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Theoretical study of anisotropic mobility in ladder-type molecule organic semiconductors

NASA Astrophysics Data System (ADS)

Wei, Hui-Ling; Liu, Yu-Fang

2014-09-01

The properties of two ladder-type semiconductors {M1: 2,2'-(2,7-dihexy1-4,9-dihydro- s-indaceno[1,2- b:5,6- b']dithiophene-4,9-diylidene) dimalononitrile and M2: 2,7-dihexy1-4,9-dihydro- s-indaceno[1,2- b:5,6- b']dithiophene-4,9-dione} as the n-type and ambipolar organic materials are systematically investigated using the first-principle density functional theory combined with the Marcus-Hush electron transfer theory. It is found that the substitution of M1 induces large changes in its electron-transfer mobility of 1.370 cm2 V-1 s-1. M2 has both large electron- and hole-transfer mobility of 0.420 and 0.288 cm2 V-1 s-1, respectively, which indicates that M2 is potentially a high efficient ambipolar organic semiconducting material. Both the M1 and M2 crystals show remarkable anisotropic behavior. A proper design of the n-type and ambipolar organic electronic materials, which may have high mobility performance, is suggested based on the investigated two molecules.

Os, Nd and Sr isotope and trace element geochemistry of the Muli picrites: Insights into the mantle source of the Emeishan Large Igneous Province

NASA Astrophysics Data System (ADS)

Li, Jie; Xu, Ji-Feng; Suzuki, Katsuhiko; He, Bin; Xu, Yi-Gang; Ren, Zhong-Yuan

2010-09-01

A suite of picrites and basalts from the Muli area, in the northwestern part of the Emeishan continental flood basalt province, provides new and valuable information on the geochemistry of the Emeishan Large Igneous Province (LIP) and its source. The Muli picrites can be classified as type-1 or type-2. The former shows ocean-island basalt-like trace element characteristics, with γ Os (260 Ma) values and ɛ Nd (260 Ma) values ranging from + 7.5 to + 11.5 and from + 6.0 to + 7.8, respectively. This is the first time that picrites with highly radiogenic Os and high Os contents (up to 3.3 ppb) have been recognized in the Emeishan LIP. These characteristics probably reflect a relatively enriched component in the Emeishan LIP source. The type-2 picrites are characterized by non-radiogenic γ Os (260 Ma) values ranging from - 4.2 to - 0.3, and they may be further subdivided into type-2A and type-2B picrites. Type-2A picrites contain moderate amounts of the light rare earth elements (LREEs), have low Ce N/Yb N values (1.1-2.0), and a relatively high initial ɛ Nd (+ 5.0 to + 6.6). In terms of Os and Nd isotopes, the Muli type-2A picrites are similar to the Song Da komatiites of Vietnam and the Gorgona Island picrites, revealing the existence of a depleted mantle component in the Emeishan LIP source. In contrast with the type-2A picrites, type-2B lavas exhibit a negative Nb anomaly and relatively lower initial ɛ Nd and γ Os values (Nb/La > 1.8; ɛ Nd (260 Ma) = - 5.5 to + 6.4; γ Os (260 Ma) = - 4.2 to - 1.9), suggesting that the type-2B lavas have a depleted mantle source, similar to type-2A, but that the type-2B lavas are also influenced by various degrees of mixing of depleted plume-derived melt, sub-continental lithospheric mantle, and/or continental crust. Given that the basalts in the Muli area show similar geochemical features to those of the type-2B picrites, their origins are inferred to be similar.

Trivalent Chromium Supplementation Ameliorates Oleic Acid-Induced Hepatic Steatosis in Mice.

PubMed

Wang, Song; Wang, Jian; Liu, Yajing; Li, Hui; Wang, Qiao; Huang, Zhiwei; Liu, Wenbin; Shi, Ping

2018-05-24

Trivalent chromium [Cr(III)] is recognized as an essential trace element for human health, whereas its effect on hepatic lipid metabolism has not yet been fully understood. This study aimed to investigate the beneficial effects and potential mechanisms of Cr(III) on hepatic steatosis in an oleic acid (OA) induced mice model. Mice were fed with high OA for 12 weeks to induce lipid accumulation, and co-administrated with Cr(III) supplementation. Indexes of liver lipid accumulation, associated lipid genes expression, fatty acids (FAs) profile and inflammatory cytokines were analyzed. The data showed that Cr(III) supplementation could attenuate disease progress of hepatic steatosis and protect liver from high OA. After Cr(III) supplementation, elevated body weight and liver injury in steatosis mice were reversed, excessive lipid accumulation and FAs were also reduced. The up-regulation of cluster of differentiation 36 (CD36) and diacylglycerol acyltransferase 2 (DGAT2) following steatosis induction were inhibited by Cr(III). Cr(III) reduced the content of pro-inflammatory cytokines (IL-1β and TNF-α, IL-12) and restored the level of anti-inflammatory cytokine (IL-10) to the control values. Our results suggest that Cr(III) supplementation is a novel strategy for alleviating OA-induced hepatic steatosis.

Selective effect of irradiation on responses to thymus-independent antigen.

PubMed

Lee, S K; Woodland, R T

1985-02-01

Low doses of ionizing radiation have a selective immunosuppressive effect on in vivo B cell responses to thymus-independent (TI) antigens. The B cell response, assayed as direct anti-trinitrophenyl (TNP)-specific plaque-forming cells (PFC), induced by type 2, TI antigens (TNP-Ficoll or TNP-Dextran), was reduced, on the average, by 10-fold in animals exposed to 200 rad of ionizing radiation 24 hr before antigen challenge. In contrast, PFC responses to type 1, TI antigens (TNP-lipopolysaccharide or TNP-Brucella abortus) are unaffected in mice exposed to the same dose of radiation. Adoptive transfers showed that this selective immunosuppression is a result of the specific inactivation of the B cell subpopulation responding to type 2, TI antigens. These experiments suggest that physiologic differences exist in the B cell subpopulations of normal mice which respond to type 1, or type 2, TI antigens.

Microwave spectrum of 2,6-dimethylcyclohexanone

NASA Astrophysics Data System (ADS)

Jang, Heesu; Shim, Jae-Seol; Oh, Jung Jin

2017-07-01

The rotational spectrum of 2,6-dimethylcyclohexanone (DMCHO) was measured in the frequency region from 6 to 12 GHz. Among three possible conformational isomers, two conformers were identified where two methyl groups are aligned in the equatorial/equatorial (ee) and the equatorial/axial (ea) positions. Both b-type and c-type transitions for (e,e)-2,6-DMCHO, and a-type, b-type, and c-type transitions for (e,a)-2,6-DMCHO were assigned to determine the rotational constants and quartic centrifugal distortion constants based on the Watson-A reduction Hamiltonian: (ee) A = 2150.95789(48) MHz, B = 1578.76212(40) MHz, C = 990.19141(45) MHz, ΔJ = 0.086(11) kHz, ΔJK = -0.134(20) kHz, ΔK = 0.298(15) kHz, δJ = 23.4(24) Hz, and δK = 101.4(77) Hz; and (ea) A = 2082.62538(83) MHz, B = 1566.59564(59) MHz, C = 1113.90153(75) MHz, ΔJ = 0.066(23) kHz. In addition, dipole moment components of the two isomers were determined by Stark effect measurements: (ee) μb = 2.6673(12) D, μc = 1.0379(11) D, μtotal = 2.8621(12) D; and (ea) μa = 1.385(253) D, μb = 2.358(104) D, μc = 1.172(21) D, μtotal = 2.975(144) D. Ab initio calculations for all three isomers were compared with each other and with experimental results.

Immunogenicity and safety evaluation of bivalent types 1 and 3 oral poliovirus vaccine by comparing different poliomyelitis vaccination schedules in China: A randomized controlled non-inferiority clinical trial.

PubMed

Qiu, Jingjun; Yang, Yunkai; Huang, Lirong; Wang, Ling; Jiang, Zhiwei; Gong, Jian; Wang, Wei; Wang, Hongyan; Guo, Shaohong; Li, Chanjuan; Wei, Shuyuan; Mo, Zhaojun; Xia, Jielai

2017-06-03

The type 2 component of the oral poliovirus vaccine is targeted for global withdrawal through a switch from the trivalent oral poliovirus vaccine (tOPV) to a bivalent oral poliovirus vaccine (bOPV). The switch is intended to prevent paralytic polio caused by circulating vaccine-derived poliovirus type 2. We aimed to assess the immunogenicity and safety profile of 6 vaccination schedules with different sequential doses of inactivated poliovirus vaccine (IPV), tOPV, or bOPV. A randomized controlled trial was conducted in China in 2015. Healthy newborn babies randomly received one of the following 6 vaccination schedules: cIPV-bOPV-bOPV(I-B-B), cIPV-tOPV-tOPV(I-T-T), cIPV-cIPV-bOPV(I-I-B), cIPV-cIPV-tOPV(I-I-T), cIPV-cIPV-cIPV(I-I-I), or tOPV-tOPV-tOPV(T-T-T). Doses were administered sequentially at 4-6 week intervals after collecting baseline blood samples. Patients were proactively followed up for observation of adverse events after the first dose and 30 days after all doses. The primary study objective was to investigate the immunogenicity and safety profile of different vaccine schedules, evaluated by seroconversion, seroprotection and antibody titer against poliovirus types 1, 2, and 3 in the per-protocol population. Of 600 newborn babies enrolled, 504 (84.0%) were included in the per-protocol population. For type 1 poliovirus, the differences in the seroconversion were 1.17% (95% CI = -2.74%, 5.08%) between I-B-B and I-T-T and 0.00% (95% CI: -6.99%, 6.99%) between I-I-B and I-I-T; for type 3 poliovirus, differences in the seroconversion were 3.49% (95% CI: -1.50%, 8.48%) between I-B-B and I-T-T and -2.32% (95% CI: -5.51%, 0.86%) between I-I-B and I-I-T. The non-inferiority conclusion was achieved in both poliovirus type 1 and 3 with the margin of -10%. Of 24 serious adverse events reported, no one was vaccine-related. The vaccination schedules with bOPV followed by one or 2 doses of IPV were recommended to substitute for vaccinations involving tOPV without compromising the immunogenicity and safety in the Chinese population. The findings will be essential for policy formulation by national and global authorities to facilitate polio elimination.

Genetic Causes of Rickets

PubMed Central

Acar, Sezer; Demir, Korcan; Shi, Yufei

2017-01-01

Rickets is a metabolic bone disease that develops as a result of inadequate mineralization of growing bone due to disruption of calcium, phosphorus and/or vitamin D metabolism. Nutritional rickets remains a significant child health problem in developing countries. In addition, several rare genetic causes of rickets have also been described, which can be divided into two groups. The first group consists of genetic disorders of vitamin D biosynthesis and action, such as vitamin D-dependent rickets type 1A (VDDR1A), vitamin D-dependent rickets type 1B (VDDR1B), vitamin D-dependent rickets type 2A (VDDR2A), and vitamin D-dependent rickets type 2B (VDDR2B). The second group involves genetic disorders of excessive renal phosphate loss (hereditary hypophosphatemic rickets) due to impairment in renal tubular phosphate reabsorption as a result of FGF23-related or FGF23-independent causes. In this review, we focus on clinical, laboratory and genetic characteristics of various types of hereditary rickets as well as differential diagnosis and treatment approaches. PMID:29280738

Clinical, immunologic and insulin secretory characteristics of young black South African patients with diabetes: Hospital based single centre study.

PubMed

Ekpebegh, C O; Longo-Mbenza, B

2013-03-01

To classify and characterize the clinical features of various diabetes classes among young black South Africans. Cross sectional study of 60 black patients with diabetes, all less than 30 years of age and attending Nelson Mandela Academic Hospital, Mthatha, South Africa. Diabetes was classified as Types 1A, 1B and 2 based on the anti-glutamic acid decarboxylase status and serum C-peptide response to intravenous injection of glucagon. Mean age was 19.6±4.8 years (n=60) with similar gender distribution. The mean duration of diabetes was 24.2±45.1 months. Type 1A was the class of diabetes in 55% (n=33/60) of patients. Type 1B and 2 accounted for 30% (n=18/60) and 15% (n=9/60) of patients respectively. Patients classified as Type 2 had higher waist circumference and higher prevalence of acanthosis nigricans than Types 1A and 1B groups. History of diabetes in a first degree relative and hypertension were found in similar proportions of patients with Types 1A, 1B and 2 diabetes. Five Type 1A diabetes patients had body mass index of 26.2-41kg/m(2) and this included two newly diagnosed patients with body mass index of 26.7kg/m(2) and 33.2kg/m(2). The majority of our young black South Africans with diabetes are of the Type 1A class. Acanthosis nigricans was not found in any patient with Type 1 A diabetes. A minority of Type 1 A diabetes patients were obese at initial diagnosis. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

A gain-of-function mutation in Tnni2 impeded bone development through increasing Hif3a expression in DA2B mice.

PubMed

Zhu, Xiaoquan; Wang, Fengchao; Zhao, Yanyang; Yang, Peng; Chen, Jun; Sun, Hanzi; Liu, Lei; Li, Wenjun; Pan, Lin; Guo, Yanru; Kou, Zhaohui; Zhang, Yu; Zhou, Cheng; He, Jiang; Zhang, Xue; Li, Jianxin; Han, Weitian; Li, Jian; Liu, Guanghui; Gao, Shaorong; Yang, Ze

2014-10-01

Distal arthrogryposis type 2B (DA2B) is an important genetic disorder in humans. However, the mechanisms governing this disease are not clearly understood. In this study, we generated knock-in mice carrying a DA2B mutation (K175del) in troponin I type 2 (skeletal, fast) (TNNI2), which encodes a fast-twitch skeletal muscle protein. Tnni2K175del mice (referred to as DA2B mice) showed typical DA2B phenotypes, including limb abnormality and small body size. However, the current knowledge concerning TNNI2 could not explain the small body phenotype of DA2B mice. We found that Tnni2 was expressed in the osteoblasts and chondrocytes of long bone growth plates. Expression profile analysis using radii and ulnae demonstrated that Hif3a expression was significantly increased in the Tnni2K175del mice. Chromatin immunoprecipitation assays indicated that both wild-type and mutant tnni2 protein can bind to the Hif3a promoter using mouse primary osteoblasts. Moreover, we showed that the mutant tnni2 protein had a higher capacity to transactivate Hif3a than the wild-type protein. The increased amount of hif3a resulted in impairment of angiogenesis, delay in endochondral ossification, and decrease in chondrocyte differentiation and osteoblast proliferation, suggesting that hif3a counteracted hif1a-induced Vegf expression in DA2B mice. Together, our data indicated that Tnni2K175del mutation led to abnormally increased hif3a and decreased vegf in bone, which explain, at least in part, the small body size of Tnni2K175del mice. Furthermore, our findings revealed a new function of tnni2 in the regulation of bone development, and the study of gain-of-function mutation in Tnni2 in transgenic mice opens a new avenue to understand the pathological mechanism of human DA2B disorder.

Cushing Disease in a patient with Multiple Endocrine Neoplasia type 2B.

PubMed

Kasturi, Kannan; Fernandes, Lucas; Quezado, Martha; Eid, Mary; Marcus, Leigh; Chittiboina, Prashant; Rappaport, Mark; Stratakis, Constantine A; Widemann, Brigitte; Lodish, Maya

2017-06-01

Multiple endocrine neoplasia type 2B (MEN2B) is a rare autosomal-dominant cancer syndrome characterized in part by metastatic medullary thyroid cancer (MTC) and pheochromocytoma. Cushing disease is a rare cause of endogenous hypercortisolism in children. We describe a 21-year-old African-American male who was diagnosed at age 10 with an ACTH-secreting pituitary microadenoma. At age 16 he developed medullary thyroid cancer and was found to have multiple endocrine neoplasia type 2B with the characteristic M918T mutation of the RET proto-oncogene. Following thyroidectomy, he was initiated on Vandetanib, a tyrosine kinase inhibitor, and has since had stable disease over the last 5 years. Our patient is the first individual with MEN2B to be described with Cushing disease. The RET oncogene may play a role in pituitary tumorigenesis; alternatively, the coexistence of these two entities may represent an extremely rare coincidence.

49 CFR 387.323 - Electronic filing of surety bonds, trust fund agreements, certificates of insurance and...

Code of Federal Regulations, 2012 CFR

2012-10-01

... Description RequiredF=filing C=cancel B=both Start field End field Record type 1 Numeric 1=Filing 2=Cancellation B 1 1 Insurer number 8 Text FMCSA Assigned Insurer Number (Home Office) With Suffix (Issuing Office), If Different, e.g. 12345-01 B 2 9 Filing type 1 Numeric 1 = BI&PD 2 = Cargo 3 = Bond 4 = Trust...

49 CFR 387.323 - Electronic filing of surety bonds, trust fund agreements, certificates of insurance and...

Code of Federal Regulations, 2011 CFR

2011-10-01

... Description RequiredF=filing C=cancel B=both Start field End field Record type 1 Numeric 1=Filing 2=Cancellation B 1 1 Insurer number 8 Text FMCSA Assigned Insurer Number (Home Office) With Suffix (Issuing Office), If Different, e.g. 12345-01 B 2 9 Filing type 1 Numeric 1 = BI&PD 2 = Cargo 3 = Bond 4 = Trust...

The new intra-articular calcaneal fracture classification system in term of sustentacular fragment configurations and incorporation of posterior calcaneal facet fractures with fracture components of the calcaneal body.

PubMed

Harnroongroj, Thossart; Harnroongroj, Thos; Suntharapa, Thongchai; Arunakul, Marut

2016-10-01

The aim of this study was to develop a new calcaneal fracture classification system which will consider sustentacular fragment configuration and relation of posterior calcaneal facet to calcaneal body. The new classification system used sustentacular fragment configuration and relation of posterior calcaneal facet fracture with fracture components of calcaneal body as key aspects of main types and subtypes. Between 2000 and 2014, 126 intraarticular calcaneal fractures were classified according to the new classification system by using computed tomography images. The new classification system was studied in term of reliability, correlation to choices of treatment, implant fixation and quality of fracture reduction. Types of sustentacular fragment comprised type A, B and C. Type A sustentacular fragment included sustentacular tali containing middle calcaneal facet. In Type B and C fractures sustentacular fragment included medial aspect and entire posterior calcaneal facet as a single unit, respectively. The fractures with type A, B and C sustentacular fragments were classified as main type A, B and C intra-articular calcaneal fractures. The main type A and B comprised 4 subtypes. Subtypes A1, A3, B1, and B3 associated with avulsion and bending fragments of calcaneal body. Subtype A2, B2, and B4 associated with burst calcaneal body. Subtype B4 was not found in the study. Main type C had no subtype and associated with burst calcaneal body. The data showed good reliability. The study showed that our new intra-articular calcaneal fracture classification system correlates to choices of treatment, implant fixation and quality of fracture reduction. Level IV, Study of Diagnostic Test. Copyright © 2016 Turkish Association of Orthopaedics and Traumatology. Production and hosting by Elsevier B.V. All rights reserved.

Transgenic analysis of a SoxB gene reveals neural progenitor cells in the cnidarian Nematostella vectensis.

PubMed

Richards, Gemma Sian; Rentzsch, Fabian

2014-12-01

Bilaterian neurogenesis is characterized by the generation of diverse neural cell types from dedicated neural stem/progenitor cells (NPCs). However, the evolutionary origin of NPCs is unclear, as neurogenesis in representatives of the bilaterian sister group, the Cnidaria, occurs via interstitial stem cells that also possess broader, non-neural, developmental potential. We address this question by analysing neurogenesis in an anthozoan cnidarian, Nematostella vectensis. Using a transgenic reporter line, we show that NvSoxB(2) - an orthologue of bilaterian SoxB genes that have conserved roles in neurogenesis - is expressed in a cell population that gives rise to sensory neurons, ganglion neurons and nematocytes: the three primary neural cell types of cnidarians. EdU labelling together with in situ hybridization, and within the NvSoxB(2)::mOrange transgenic line, demonstrates that cells express NvSoxB(2) before mitosis and identifies asymmetric behaviours of sibling cells within NvSoxB(2)(+) lineages. Morpholino-mediated gene knockdown of NvSoxB(2) blocks the formation of all three neural cell types, thereby identifying NvSoxB(2) as an essential positive regulator of nervous system development. Our results demonstrate that diverse neural cell types derive from an NvSoxB(2)-expressing population of mitotic cells in Nematostella and that SoxB genes are ancient components of a neurogenic program. To our knowledge this is the first description of a lineage-restricted, multipotent cell population outside the Bilateria and we propose that neurogenesis via dedicated, SoxB-expressing NPCs predates the split between cnidarians and bilaterians. © 2014. Published by The Company of Biologists Ltd.

Assessment: transcranial Doppler ultrasonography: report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology.

PubMed

Sloan, M A; Alexandrov, A V; Tegeler, C H; Spencer, M P; Caplan, L R; Feldmann, E; Wechsler, L R; Newell, D W; Gomez, C R; Babikian, V L; Lefkowitz, D; Goldman, R S; Armon, C; Hsu, C Y; Goodin, D S

2004-05-11

To review the use of transcranial Doppler ultrasonography (TCD) and transcranial color-coded sonography (TCCS) for diagnosis. The authors searched the literature for evidence of 1) if TCD provides useful information in specific clinical settings; 2) if using this information improves clinical decision making, as reflected by improved patient outcomes; and 3) if TCD is preferable to other diagnostic tests in these clinical situations. TCD is of established value in the screening of children aged 2 to 16 years with sickle cell disease for stroke risk (Type A, Class I) and the detection and monitoring of angiographic vasospasm after spontaneous subarachnoid hemorrhage (Type A, Class I to II). TCD and TCCS provide important information and may have value for detection of intracranial steno-occlusive disease (Type B, Class II to III), vasomotor reactivity testing (Type B, Class II to III), detection of cerebral circulatory arrest/brain death (Type A, Class II), monitoring carotid endarterectomy (Type B, Class II to III), monitoring cerebral thrombolysis (Type B, Class II to III), and monitoring coronary artery bypass graft operations (Type B to C, Class II to III). Contrast-enhanced TCD/TCCS can also provide useful information in right-to-left cardiac/extracardiac shunts (Type A, Class II), intracranial occlusive disease (Type B, Class II to IV), and hemorrhagic cerebrovascular disease (Type B, Class II to IV), although other techniques may be preferable in these settings.

Role of B7 costimulatory molecules in immune responses and T-helper cell differentiation in response to recombinant HagB from Porphyromonas gingivalis.

PubMed

Zhang, Ping; Martin, Michael; Yang, Qiu-Bo; Michalek, Suzanne M; Katz, Jannet

2004-02-01

In addition to antigen-specific signals mediated through the T-cell receptor, T cells also require antigen nonspecific costimulation for activation. The B7 family of molecules on antigen-presenting cells, which include B7-1 (CD80) and B7-2 (CD86), play important roles in providing costimulatory signals required for development of antigen-specific immune responses. Hemagglutinin B (HagB) is a nonfimbrial adhesin of the periodontopathic microorganism Porphyromonas gingivalis and is thought to be involved in the attachment of the bacterium to host tissues. However, the immune mechanisms involved in responses to HagB and their roles in pathogenesis have yet to be elucidated. Therefore, the purpose of this study was to determine the role of B7 costimulatory molecules on T-helper-cell differentiation for the induction of immune responses to HagB. Mice deficient in either or both of the costimulatory molecules B7-1 and B7-2 were used to explore their role in immune responses to HagB after subcutaneous immunization. B7-1(-/-) mice had levels of immunoglobulin G (IgG) anti-HagB antibody activity in serum similar to those of wild-type mice, whereas lower serum IgG anti-HagB antibody responses were seen in B7-2(-/-) mice. Moreover, significantly lower numbers of IgG antibody-secreting cells and lower levels of CD4(+)-T-cell proliferation were observed in B7-2(-/-) mice compared to wild-type mice. No serum IgG response to HagB was detected in B7-1/B7-2(-/-) mice. Analysis of the subclass of the serum IgG responses and the cytokines induced in response to HagB revealed that B7-2(-/-) mice had significantly lower IgG1 and higher IgG2a anti-HagB antibody responses compared to wild-type mice. The B7-2(-/-) mice also had significantly reduced levels of interleukin-4 (IL-4) and IL-5 and enhanced level of gamma interferon. Furthermore, assessment of B7-1 and B7-2 expression on B cells and macrophages derived from wild-type BALB/c mice after in vitro stimulation with HagB revealed a predominant upregulation in the expression of the B7-2 costimulatory molecule on B cells and macrophages. Essentially no change was seen in the expression of B7-1. Taken together, these results suggest a critical role for B7, especially B7-2, for the preferential induction of a Th2-like response to HagB.

C-Terminal Region of EBNA-2 Determines the Superior Transforming Ability of Type 1 Epstein-Barr Virus by Enhanced Gene Regulation of LMP-1 and CXCR7

PubMed Central

Cancian, Laila; Bosshard, Rachel; Lucchesi, Walter; Karstegl, Claudio Elgueta; Farrell, Paul J.

2011-01-01

Type 1 Epstein-Barr virus (EBV) strains immortalize B lymphocytes in vitro much more efficiently than type 2 EBV, a difference previously mapped to the EBNA-2 locus. Here we demonstrate that the greater transforming activity of type 1 EBV correlates with a stronger and more rapid induction of the viral oncogene LMP-1 and the cell gene CXCR7 (which are both required for proliferation of EBV-LCLs) during infection of primary B cells with recombinant viruses. Surprisingly, although the major sequence differences between type 1 and type 2 EBNA-2 lie in N-terminal parts of the protein, the superior ability of type 1 EBNA-2 to induce proliferation of EBV-infected lymphoblasts is mostly determined by the C-terminus of EBNA-2. Substitution of the C-terminus of type 1 EBNA-2 into the type 2 protein is sufficient to confer a type 1 growth phenotype and type 1 expression levels of LMP-1 and CXCR7 in an EREB2.5 cell growth assay. Within this region, the RG, CR7 and TAD domains are the minimum type 1 sequences required. Sequencing the C-terminus of EBNA-2 from additional EBV isolates showed high sequence identity within type 1 isolates or within type 2 isolates, indicating that the functional differences mapped are typical of EBV type sequences. The results indicate that the C-terminus of EBNA-2 accounts for the greater ability of type 1 EBV to promote B cell proliferation, through mechanisms that include higher induction of genes (LMP-1 and CXCR7) required for proliferation and survival of EBV-LCLs. PMID:21857817

Evidence for Sequence Scrambling and Divergent H/D Exchange Reactions of Doubly-Charged Isobaric b-Type Fragment Ions

NASA Astrophysics Data System (ADS)

Zekavat, Behrooz; Miladi, Mahsan; Al-Fdeilat, Abdullah H.; Somogyi, Arpad; Solouki, Touradj

2014-02-01

To date, only a limited number of reports are available on structural variants of multiply-charged b-fragment ions. We report on observed bimodal gas-phase hydrogen/deuterium exchange (HDX) reaction kinetics and patterns for substance P b10 2+ that point to presence of isomeric structures. We also compare HDX reactions, post-ion mobility/collision-induced dissociation (post-IM/CID), and sustained off-resonance irradiation-collision induced dissociation (SORI-CID) of substance P b10 2+ and a cyclic peptide with an identical amino acid (AA) sequence order to substance P b10. The observed HDX patterns and reaction kinetics and SORI-CID pattern for the doubly charged head-to-tail cyclized peptide were different from either of the presumed isomers of substance P b10 2+, suggesting that b10 2+ may not exist exclusively as a head-to-tail cyclized structure. Ultra-high mass measurement accuracy was used to assign identities of the observed SORI-CID fragment ions of substance P b10 2+; over 30 % of the observed SORI-CID fragment ions from substance P b10 2+ had rearranged (scrambled) AA sequences. Moreover, post-IM/CID experiments revealed the presence of two conformer types for substance P b10 2+, whereas only one conformer type was observed for the head-to-tail cyclized peptide. We also show that AA sequence scrambling from CID of doubly-charged b-fragment ions is not unique to substance P b10 2+.

Evidence for sequence scrambling and divergent H/D exchange reactions of doubly-charged isobaric b-type fragment ions.

PubMed

Zekavat, Behrooz; Miladi, Mahsan; Al-Fdeilat, Abdullah H; Somogyi, Arpad; Solouki, Touradj

2014-02-01

To date, only a limited number of reports are available on structural variants of multiply-charged b-fragment ions. We report on observed bimodal gas-phase hydrogen/deuterium exchange (HDX) reaction kinetics and patterns for substance P b10(2+) that point to presence of isomeric structures. We also compare HDX reactions, post-ion mobility/collision-induced dissociation (post-IM/CID), and sustained off-resonance irradiation-collision induced dissociation (SORI-CID) of substance P b10(2+) and a cyclic peptide with an identical amino acid (AA) sequence order to substance P b10. The observed HDX patterns and reaction kinetics and SORI-CID pattern for the doubly charged head-to-tail cyclized peptide were different from either of the presumed isomers of substance P b10(2+), suggesting that b10(2+) may not exist exclusively as a head-to-tail cyclized structure. Ultra-high mass measurement accuracy was used to assign identities of the observed SORI-CID fragment ions of substance P b10(2+); over 30% of the observed SORI-CID fragment ions from substance P b10(2+) had rearranged (scrambled) AA sequences. Moreover, post-IM/CID experiments revealed the presence of two conformer types for substance P b10(2+), whereas only one conformer type was observed for the head-to-tail cyclized peptide. We also show that AA sequence scrambling from CID of doubly-charged b-fragment ions is not unique to substance P b10(2+).

Copernicus observations of the N v resonance doublet in 53 early-type stars

NASA Technical Reports Server (NTRS)

Abbott, D. C.; Bohlin, R. C.; Savage, B. D.

1982-01-01

UV spectra in the wavelength interval 1170-1270 A are presented for 53 early-type stars ranging in spectral type from O6.5 V to B2.5 IV. The sample includes four Wolf-Rayet stars, seven known Oe-Be stars, and six galactic halo OB stars. A qualitative analysis of the stellar N v doublet reveals that: (1) N v is present in all stars hotter and more luminous than type B0 for the main sequence, B1 for giants, and B2 for supergiants; (2) shell components of N v and an unidentified absorption feature at 1230 A are present in about half of the stars; (3) the column density of N v is well correlated with bolometric luminosity over the spectral range O6 to B2; and (4) the ratio of emission to absorption equivalent width is a factor of 2 smaller in the main sequence stars than in supergiants, which suggests that the wind structure changes as a star evolves. For several stars, this ratio is too small to be explained by traditional wind models.

Modelling of MWIR HgCdTe complementary barrier HOT detector

NASA Astrophysics Data System (ADS)

Martyniuk, Piotr; Rogalski, Antoni

2013-02-01

The paper reports on the photoelectrical performance of medium wavelength infrared (MWIR) HgCdTe complementary barrier infrared detector (CBIRD) with n-type barriers. CBIRD nB1nB2 HgCdTe/B1,2-n type detector is modelled with commercially available software APSYS by Crosslight Software Inc. The detailed analysis of the detector's performance such as dark current, photocurrent, responsivity, detectivity versus applied bias, operating temperature, and structural parameters (cap, barriers and absorber doping; and absorber and barriers compositions) are performed pointing out optimal working conditions. Both conduction and valence bands' alignment of the HgCdTe CBIRD structure are calculated stressing their importance on detectors performance. It is shown that higher operation temperature (HOT) conditions achieved by commonly used thermoelectric (TE) coolers allows to obtain detectivities D∗ ≈ 2 × 1010 cm Hz1/2/W at T = 200 K and reverse polarisation V = 400 mV, and differential resistance area product RA = 0.9 Ωcm2 at T = 230 K for V = 50 mV, respectively. Finally, CBIRD nB1nB2 HgCdTe/B1,2-n type state of the art is compared to unipolar barrier HgCdTe nBn/B-n type detector, InAs/GaSb/B-Al0.2Ga0.8Sb type-II superlattice (T2SL) nBn detectors, InAs/GaSb T2SLs PIN and the HOT HgCdTe bulk photodiodes' performance operated at near-room temperature (T = 230 K). It was shown that the RA product of the MWIR CBIRD HgCdTe detector is either comparable or higher (depending on structural parameters) to the state of the art of HgCdTe HOT bulk photodiodes and both AIIIBV 6.1 Å family T2SLs nBn and PIN detectors.

Multiplex Amplification Refractory Mutation System PCR (ARMS-PCR) provides sequencing independent typing of canine parvovirus.

PubMed

Chander, Vishal; Chakravarti, Soumendu; Gupta, Vikas; Nandi, Sukdeb; Singh, Mithilesh; Badasara, Surendra Kumar; Sharma, Chhavi; Mittal, Mitesh; Dandapat, S; Gupta, V K

2016-12-01

Canine parvovirus-2 antigenic variants (CPV-2a, CPV-2b and CPV-2c) ubiquitously distributed worldwide in canine population causes severe fatal gastroenteritis. Antigenic typing of CPV-2 remains a prime focus of research groups worldwide in understanding the disease epidemiology and virus evolution. The present study was thus envisioned to provide a simple sequencing independent, rapid, robust, specific, user-friendly technique for detecting and typing of presently circulating CPV-2 antigenic variants. ARMS-PCR strategy was employed using specific primers for CPV-2a, CPV-2b and CPV-2c to differentiate these antigenic types. ARMS-PCR was initially optimized with reference positive controls in two steps; where first reaction was used to differentiate CPV-2a from CPV-2b/CPV-2c. The second reaction was carried out with CPV-2c specific primers to confirm the presence of CPV-2c. Initial validation of the ARMS-PCR was carried out with 24 sequenced samples and the results were matched with the sequencing results. ARMS-PCR technique was further used to screen and type 90 suspected clinical samples. Randomly selected 15 suspected clinical samples that were typed with this technique were sequenced. The results of ARMS-PCR and the sequencing matched exactly with each other. The developed technique has a potential to become a sequencing independent method for simultaneous detection and typing of CPV-2 antigenic variants in veterinary disease diagnostic laboratories globally. Copyright © 2016 Elsevier B.V. All rights reserved.

B-cell-specific depletion of tumour necrosis factor alpha inhibits atherosclerosis development and plaque vulnerability to rupture by reducing cell death and inflammation.

PubMed

Tay, Christopher; Liu, Yu-Han; Hosseini, Hamid; Kanellakis, Peter; Cao, Anh; Peter, Karlheinz; Tipping, Peter; Bobik, Alex; Toh, Ban-Hock; Kyaw, Tin

2016-09-01

B2 lymphocytes promote atherosclerosis development but their mechanisms of action are unknown. Here, we investigated the role of tumour necrosis factor alpha (TNF-α) produced by B2 cells in atherogenesis. We found that 50% of TNF-α-producing spleen lymphocytes were B2 cells and ∼20% of spleen and aortic B cells produced TNF-α in hyperlipidemic ApoE(-/-) mice. We generated mixed bone marrow (80% μMT/20% TNF-α(-/-)) chimeric LDLR(-/-) mice where only B cells did not express TNF-α. Atherosclerosis was reduced in chimeric LDLR(-/-) mice with TNF-α-deficient B cells. TNF-α expression in atherosclerotic lesions and in macrophages were also reduced accompanied by fewer apoptotic cells, reduced necrotic cores, and reduced lesion Fas, interleukin-1β and MCP-1 in mice with TNF-α-deficient B cells compared to mice with TNF-α-sufficient B cells. To confirm that the reduced atherosclerosis is attributable to B2 cells, we transferred wild-type and TNF-α-deficient B2 cells into ApoE(-/-) mice deficient in B cells or in lymphocytes. After 8 weeks of high fat diet, we found that atherosclerosis was increased by wild-type but not TNF-α-deficient B2 cells. Lesions of mice with wild-type B2 cells but not TNF-α-deficient B2 cells also had increased apoptotic cells and necrotic cores. Transferred B2 cells were found in lesions of recipient mice, suggesting that TNF-α-producing B2 cells promote atherosclerosis within lesions. We conclude that TNF-α produced by B2 cells is a key mechanism by which B2 cells promote atherogenesis through augmenting macrophage TNF-α production to induce cell death and inflammation that promote plaque vulnerability. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.

Molecular Characteristics of Influenza Virus Type B Lineages Circulating in Poland.

PubMed

Bednarska, K; Hallmann-Szelińska, E; Kondratiuk, K; Rabczenko, D; Brydak, L B

2016-01-01

From the time of the Hong Kong pandemic of 1968-1969, vaccines against influenza are trivalent, containing two subtypes of influenza type A: A/H1N1/ and A/H3N2/, and influenza type B. In 1980, circulation of the new Yamagata and Victoria lineages of influenza B virus was noted. Since both lineages have continued to circulate, the second lineage of influenza B was included into the trivalent vaccine as of the 2013/2014 epidemic season. In Poland, co-circulation of influenza type A and B has been registered over many seasons, although type A has predominated. According to the ACIP recommendations, quadrivalent vaccines against influenza are administered in some continents due to circulation of the B-Yamagata and B-Victoria lineages. Currently, only trivalent vaccines against influenza are available in Poland. The aim of the present research was to determine which of the two influenza type B lineages, or possibly both, would be isolated in Poland. The study was conducted with the use of RT-PCR. Generally, in the 2014/2015 epidemic season in Poland, circulation of type B virus was confirmed in 34 % of influenza cases. A total of 89 specimens of influenza B were tested, including co-infections of influenza B with influenza A subtypes: A/H1N1/pdm09 and A/H3N2/. The findings were that only lineage B-Yamagata circulates in the Polish population. Therefore, vaccines available on the Polish market do not require the introduction of a fourth component.

Strombolian explosive styles and source conditions

USGS Publications Warehouse

Patrick, Matthew R.; Harris, Andrew J. L.; Ripepe, Maurizio; Dehn, Jonathan; Rothery, David A.; Calvari, Sonia

2007-01-01

Forward Looking Infrared Radiometer (FLIR) cameras offer a unique view of explosive volcanism by providing an image of calibrated temperatures. In this study, 344 eruptive events at Stromboli volcano, Italy, were imaged in 2001–2004 with a FLIR camera operating at up to 30 Hz. The FLIR was effective at revealing both ash plumes and coarse ballistic scoria, and a wide range of eruption styles was recorded. Eruptions at Stromboli can generally be classified into two groups: Type 1 eruptions, which are dominated by coarse ballistic particles, and Type 2 eruptions, which consist of an optically-thick, ash-rich plume, with (Type 2a) or without (Type 2b) large numbers of ballistic particles. Furthermore, Type 2a plumes exhibited gas thrust velocities (>15 m s−1 ) while Type 2b plumes were limited to buoyant velocities (<15 m s−1 ) above the crater rim. A given vent would normally maintain a particular gross eruption style (Type 1 vs. 2) for days to weeks, indicating stability of the uppermost conduit on these timescales. Velocities at the crater rim had a range of 3–101 m s−1 , with an overall mean value of 24 m s−1. Mean crater rim velocities by eruption style were: Type 1= 34 m s−1 , Type 2a=31 m s−1 , Type 2b=7 m s−1 . Eruption durations had a range of 6–41 s, with a mean of 15 s, similar among eruption styles. The ash in Type 2 eruptions originates from either backfilled material (crater wall slumping or ejecta rollback) or rheological changes in the uppermost magma column. Type 2a and 2b behaviors are shown to be a function of the overpressure of the bursting slug. In general, our imaging data support a broadening of the current paradigm for strombolian behavior, incorporating an uppermost conduit that can be more variable than is commonly considered.

Proportions of myosin heavy chain mRNAs, protein isoforms and fiber types in the slow and fast skeletal muscles are maintained after alterations of thyroid status in rats.

PubMed

Soukup, T; Diallo, M

2015-01-01

Recently, we have established that slow soleus (SOL) and fast extensor digitorum longus (EDL) muscles of euthyroid (EU) Lewis rats posses the same proportions between their four myosin heavy chain (MyHC) mRNAs, protein isoforms and fiber types as determined by real time RT-PCR, SDS-PAGE and 2-D stereological fiber type analysis, respectively. In the present paper we investigated if these proportions are maintained in adult Lewis rats with hyperthyroid (HT) and hypothyroid (HY) status. Although HT and HY states change MyHC isoform expression, results from all three methods showed that proportion between MyHC mRNA-1, 2a, -2x/d, -2b, protein isoforms MyHC-1, -2a, -2x/d, -2b and to lesser extent also fiber types 1, 2A, 2X/D, 2B were preserved in both SOL and EDL muscles. Furthermore, in the SOL muscle mRNA expression of slow MyHC-1 remained up to three orders higher compared to fast MyHC transcripts, which explains the predominance of MyHC-1 isoform and fiber type 1 even in HT rats. Although HT status led in the SOL to increased expression of MyHC-2a mRNA, MyHC-2a isoform and 2A fibers, it preserved extremely low expression of MyHC-2x and -2b mRNA and protein isoforms, which explains the absence of pure 2X/D and 2B fibers. HY status, on the other hand, almost completely abolished expression of all three fast MyHC mRNAs, MyHC protein isoforms and fast fiber types in the SOL muscle. Our data present evidence that a correlation between mRNA, protein content and fiber type composition found in EU status is also preserved in HT and HY rats.

New massive members of Cygnus OB2

NASA Astrophysics Data System (ADS)

Berlanas, S. R.; Herrero, A.; Comerón, F.; Pasquali, A.; Motta, C. Bertelli; Sota, A.

2018-04-01

Context. The Cygnus complex is one of the most powerful star forming regions at a close distance from the Sun ( 1.4 kpc). Its richest OB association Cygnus OB2 is known to harbor many tens of O-type stars and hundreds of B-type stars, providing a large homogeneous population of OB stars that can be analyzed. Many studies of its massive population have been developed in the last decades, although the total number of OB stars is still incomplete. Aim. Our aim is to increase the sample of O and B members of Cygnus OB2 and its surroundings by spectroscopically classifying 61 candidates as possible OB-type members of Cygnus OB2, using new intermediate resolution spectroscopy. Methods: We have obtained intermediate resolution (R 5000) spectra for all of the OB-type candidates between 2013 and 2017. We thus performed a spectral classification of the sample using HeI-II and metal lines rates, as well as the Marxist Ghost Buster (MGB) software for O-type stars and the IACOB standards catalog for B-type stars. Results: From the whole sample of 61 candidates, we have classified 42 stars as new massive OB-type stars, earlier than B3, in Cygnus OB2 and surroundings, including 11 O-type stars. The other candidates are discarded as they display later spectral types inconsistent with membership in the association. We have also obtained visual extinctions for all the new confirmed massive OB members, placing them in a Hertzsprung-Russell Diagram using calibrations for Teff and luminosity. Finally, we have studied the age and extinction distribution of our sample within the region. Conclusions: We have obtained new blue intermediate-resolution spectra suitable for spectral classification of 61 OB candidates in Cygnus OB2 and surroundings. The confirmation of 42 new OB massive stars (earlier than B3) in the region allows us to increase the young massive population known in the field. We have also confirmed the correlation between age and Galactic longitude previously found in the region. We conclude that many O and early B stars at B > 16 mag are still undiscovered in Cygnus.

Parity-Forbidden Transitions and Their Impact on the Optical Absorption Properties of Lead-Free Metal Halide Perovskites and Double Perovskites.

PubMed

Meng, Weiwei; Wang, Xiaoming; Xiao, Zewen; Wang, Jianbo; Mitzi, David B; Yan, Yanfa

2017-07-06

Using density functional theory calculations, we analyze the optical absorption properties of lead (Pb)-free metal halide perovskites (AB 2+ X 3 ) and double perovskites (A 2 B + B 3+ X 6 ) (A = Cs or monovalent organic ion, B 2+ = non-Pb divalent metal, B + = monovalent metal, B 3+ = trivalent metal, X = halogen). We show that if B 2+ is not Sn or Ge, Pb-free metal halide perovskites exhibit poor optical absorptions because of their indirect band gap nature. Among the nine possible types of Pb-free metal halide double perovskites, six have direct band gaps. Of these six types, four show inversion symmetry-induced parity-forbidden or weak transitions between band edges, making them not ideal for thin-film solar cell applications. Only one type of Pb-free double perovskite shows optical absorption and electronic properties suitable for solar cell applications, namely, those with B + = In, Tl and B 3+ = Sb, Bi. Our results provide important insights for designing new metal halide perovskites and double perovskites for optoelectronic applications.

Coercivity temperature dependence of Sm2Co17-type sintered magnets with different cell and cell boundary microchemistry

NASA Astrophysics Data System (ADS)

Yu, Nengjun; Zhu, Minggang; Song, Liwei; Fang, Yikun; Song, KuiKui; Wang, Qiang; Li, Wei

2018-04-01

High maximum energy product ((BH)max) Sm(CobalFe0.18Cu0.07Zr0.03)7.7 magnet (type-A) and high temperature Sm(CobalFe0.1Cu0.09Zr0.03)7.2 magnet (type-B) were prepared by a traditional powder metallurgical technology. A record (BH)max of 98.7 kJ/m3 with a coercivity (Hcj) of 501.5 kA/m at 773 K was achieved for the type-B magnet, which is much higher than that of type-A magnet (63.7 kJ/m3). The microstructures of the magnets were revealed by high-resolution transmission electron microscope. The average cell size of the type-A and B magnet are 110 nm and 90 nm, respectively. Moreover, the type-B magnet shows a wider cell boundary than the type-A magnet. Additionally, the element distribution of the cell/cell boundary interfaces was measured by energy-dispersive spectroscopy. The cell phase of the type-A magnet contains a higher Fe content as about 17 at%, comparing with that of the type-B magnet (∼8.9 at%). On the other hand, the Cu content of the cell boundary phase is 18 at% almost twice higher than the type-B magnet (8.6 at%). Theoretical Hcj temperature dependence of these two kinds of magnets indicates that the lower Cu content in the cell boundary phase and the appropriate Fe content in the cell phase are the key factors for the high Hcj for the type-B magnet at elevated temperature.

Second-moment equality and the structural chemistry of the main-group intermetallic compounds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, S.

1991-01-02

The authors determine electron counting rules for ZA{sub 2{minus}x}B{sub x} compounds, where Z is an electropositive atoms and A and B are main-group atoms. These rules are derived from a Huckel-type theory. Agreement between theory and experiment for all the major ZA{sub 2{minus}x}B{sub x} families, which include the MgCu{sub 2}, MoSi{sub 2}, CeCd{sub 2}, CeCu{sub 2}, MgAgAs, CaIn{sub 2}, AlB{sub 2}, ThSi{sub 2}, and Cu{sub 2}Sb structure types, is excellent. The results are interpreted by use of the method of moments.

The P-type ATPase CtpG preferentially transports Cd2+ across the Mycobacterium tuberculosis plasma membrane.

PubMed

López, Marcela; Quitian, Laudy-Viviana; Calderón, Martha-Nancy; Soto, Carlos-Y

2018-04-01

P 1B -type ATPases are involved in heavy metal transport across the plasma membrane. Some Mycobacterium tuberculosis P-type ATPases are induced during infection, suggesting that this type of transporter could play a critical role in mycobacterial survival. To date, the ion specificity of M. tuberculosis heavy metal-transporting P 1B -ATPases is not well understood. In this work, we observed that, although divalent heavy metal cations such as Cu 2+ , Co 2+ , Ni 2+ , Zn 2+ Cd 2+ and Pb 2+ stimulate the ATPase activity of the putative P 1B -type ATPase CtpG in the plasma membrane, whole cells of M. smegmatis expressing CtpG only tolerate high levels of Cd 2+ and Cu 2+ . As indicator of the catalytic constant, Michaelis-Menten kinetics showed that CtpG embedded in the mycobacterial cell membrane has a V max /K m ratio 7.4-fold higher for Cd 2+ than for Cu 2+ ions. Thus, although CtpG can accept different substrates in vitro, this P-type ATPase transports Cd 2+ more efficiently than other heavy metal cations across the mycobacterial plasma membrane.

Response to Stress, Cognitive Coping Strategies, and the Type A Behavior Pattern.

ERIC Educational Resources Information Center

Pittner, Mark S.; Houston, B. Kent

1980-01-01

Examines (1) whether Type A individuals respond with more psychophysiological arousal to threat to self-esteem than to threat of shock, (2) whether differences between Type A and Type B individuals in psychophysiological responses are greater under high than low stress, and (3) whether Type A and Type B individuals differ in how they cognitively…

Effect of Royal Jelly Intake on Serum Glucose, Apolipoprotein A-I (ApoA-I), Apolipoprotein B (ApoB) and ApoB/ApoA-I Ratios in Patients with Type 2 Diabetes: A Randomized, Double-Blind Clinical Trial Study.

PubMed

Khoshpey, Basemeh; Djazayeri, Shima; Amiri, Fatemehsadat; Malek, Mojtaba; Hosseini, Agha Fateme; Hosseini, Sharieh; Shidfar, Shahrzad; Shidfar, Farzad

2016-08-01

Type 2 diabetes is the most common metabolic disorder worldwide. Evidence supports a role for royal jelly (RJ) in reduction of serum glucose and lipids in animals and healthy subjects. The purpose of this study was to determine the effect of RJ intake on serum glucose, apolipoprotein A-I (ApoA-I), apolipoprotein B (ApoB) and ApoB/ApoA-I ratios in patients with type 2 diabetes. Fifty patients with type 2 diabetes participated in a double-blind, placebo-controlled study. The participants were randomly divided into RJ and placebo groups and were given doses of 1000 mg royal jelly or placebo 3 times a day for 8 weeks, respectively. Weight, height, fasting blood glucose, ApoA-I and ApoB were measured at baseline and endpoint. There were no significant differences in baseline characteristics and dietary intakes between groups. The mean difference in glucose concentrations decreased in the RJ group (-9.4 mg/dL vs. 4 mg/dL; p=0.011). The mean difference in ApoA-I concentrations increased in the RJ group (34.4 mg/dL vs. -1.08 mg/dL; p=0.013). There was a significant decrease in mean difference of ApoB/ApoA-I in the RJ group compared with the placebo group (0.008 vs. 0.13; p<0.044), respectively. These data suggest that RJ intake may have desirable effects on serum glucose, Apo-A-I concentrations and ApoB/ApoA-I ratios in people with type 2 diabetes. Copyright © 2016 Canadian Diabetes Association. Published by Elsevier Inc. All rights reserved.

Indoor Exposures to PM2.5 IN a Rural Site of South India

NASA Astrophysics Data System (ADS)

Deepthi, Y.; Nagendra, S. S.

2016-12-01

Indian villages feature heavy biomass usage and presence of unpaved roads. Characteristics of indoor PM 2.5 concentrations under these distinctive features are very specific and the related studies are emerging as crucial prerequisites for formulating its regulatory norms. In this paper, we present the measurements of real-time indoor PM2.5 exposures for households of rural southern India. Indoor exposures were measured in three types of housing (Type A- Indoor kitchen without partition, Type B- Indoor kitchen with partition and Type C- Open air kitchen) for 6 days during the winter season of 2016. PM 2.5 mass concentrations were monitored using a 32-channel optical particle counter (Model 1.109, Grimm Labortechnik Ltd., Ainring, Germany) in the living rooms of the three houses. The sampling height maintained was 1.5 m above the ground level, which is the average human breathing height. Results indicated that the PM 2.5 exposure levels were very high in the houses with indoor kitchen facility with and without partitions (Types A and B). The diurnal averaged indoor PM 2.5 concentrations were above the human permissible limit (60 μg/m3) in the Type A (133±61 μg/m3) and Type B (81±26 μg/m3) houses. Whereas in the Type C house, the 24 hr averaged PM 2.5 concentrations were within the range of 55±5 μg/m3. During the cooking periods, the hourly averaged PM2.5 concentrations (1251, 292, 159 μg/m3 in Type A, B and C house, respectively) were more than one order higher than the diurnal averaged concentrations in all the three types of houses.

Plant distribution-altitude and landform relationships in karstic sinkholes of Mediterranean region of Turkey.

PubMed

Ozkan, Kürsad; Gulsoy, Serkan; Mert, Ahmet; Ozturk, Munir; Muys, Bart

2010-01-01

The purpose of this study was to investigate the relationships between the plant distribution and the altitude-shape-size characteristics of sinkholes, and the landform characteristics inside sinkholes in the Mediterranean region of Turkey. Block kriging, Factor analysis, Cluster Analysis and Detrended Correspondence Analysis were performed. The sinkhole type and altitudinal zone were found to be the significant factors affecting the plant distribution. However, the sinkhole type was more important than the altitudinal zone. Hence, the sinkholes were first subdivided into groups according to types and then the groups were divided into subgroups according to the altitudinal zones. Consequently, 4 groups were defined; A-type sinkholes [1400-1550 m (A1), 1550-1700 m (A2)] and B-type sinkholes [1400-1550 (B1), 1550-1700 m (B2)]. The B-type was wider vertically and shorter horizontally than A-type sinkholes. Significant differences were found between the plant distribution and slope position inside the sinkholes. Plant distribution in the lower slopes was different from that in the flats and ridges in the B1 sub-type of B-type. Plant distribution in B2 subtype was different among the slope positions (ridge, middle slope, lower slope, and flat). Although distribution of plants is different in different parts (ridges, upper slope, middle slope, lower slope and basal flats) of A sinkhole, the differences between the parts of intermediate slope position are not significant. A high plant variability along short distances in the sinkholes was observed in the study area. That is why the site of sinkholes have a big potential for the distribution of many species. Hence, the area must be separated as strictly protected zone.

Double-hit or dual expression of MYC and BCL2 in primary cutaneous large B-cell lymphomas.

PubMed

Menguy, Sarah; Frison, Eric; Prochazkova-Carlotti, Martina; Dalle, Stephane; Dereure, Olivier; Boulinguez, Serge; Dalac, Sophie; Machet, Laurent; Ram-Wolff, Caroline; Verneuil, Laurence; Gros, Audrey; Vergier, Béatrice; Beylot-Barry, Marie; Merlio, Jean-Philippe; Pham-Ledard, Anne

2018-03-26

In nodal diffuse large B-cell lymphoma, the search for double-hit with MYC and BCL2 and/or BCL6 rearrangements or for dual expression of BCL2 and MYC defines subgroups of patients with altered prognosis that has not been evaluated in primary cutaneous large B-cell lymphoma. Our objectives were to assess the double-hit and dual expressor status in a cohort of 44 patients with primary cutaneous large B-cell lymphoma according to the histological subtype and to evaluate their prognosis relevance. The 44 cases defined by the presence of more than 80% of large B-cells in the dermis corresponded to 21 primary cutaneous follicle centre lymphoma with large cell morphology and 23 primary cutaneous diffuse large B-cell lymphoma, leg type. Thirty-one cases (70%) expressed BCL2 and 29 (66%) expressed MYC. Dual expressor profile was observed in 25 cases (57%) of either subtypes (n = 6 or n = 19, respectively). Only one primary cutaneous follicle centre lymphoma, large-cell case had a double-hit status (2%). Specific survival was significantly worse in primary cutaneous diffuse large B-cell lymphoma, leg type than in primary cutaneous follicle centre lymphoma, large cell (p = 0.021) and for the dual expressor primary cutaneous large B-cell lymphoma group (p = 0.030). Both overall survival and specific survival were worse for patients belonging to the dual expressor primary cutaneous diffuse large B-cell lymphoma, leg type subgroup (p = 0.001 and p = 0.046, respectively). Expression of either MYC and/or BCL2 negatively impacted overall survival (p = 0.017 and p = 0.018 respectively). As the differential diagnosis between primary cutaneous follicle centre lymphoma, large cell and primary cutaneous diffuse large B-cell lymphoma, leg type has a major impact on prognosis, dual-expression of BCL2 and MYC may represent a new diagnostic criterion for primary cutaneous diffuse large B-cell lymphoma, leg type subtype and further identifies patients with impaired survival. Finally, the double-hit assessment does not appear clinically relevant in primary cutaneous large B-cell lymphoma.

Central Role of the PPARγ Gene Network in Coordinating Beef Cattle Intramuscular Adipogenesis in Response to Weaning Age and Nutrition

PubMed Central

Moisá, Sonia J.; Shike, Daniel W.; Faulkner, Dan B.; Meteer, William T.; Keisler, Duane; Loor, Juan J.

2014-01-01

Adipogenic/lipogenic transcriptional networks regulating intramuscular fat deposition (IMF) in response to weaning age and dietary starch level were studied. The longissimus muscle (LM) of beef steers on an early weaning (141 days age) plus high-starch diet (EWS) or a normal weaning (NW, 222 days age) plus starch creep-feed diet (CFS) was biopsied at 0 (EW), 25, 50, 96 (NW), 167, and 222 (pre-slaughter) days. Expression patterns of 35 target genes were studied. From NW through slaughter, all steers received the same high-starch diet. In EWS steers the expression of PPARG, other adipogenic (CEBPA, ZFP423) and lipogenic (THRSP, SREBF1, INSIG1) activators, and several enzymes (FASN, SCD, ELOVL6, PCK1, DGAT2) that participate in the process of IMF increased gradually to a peak between 96 and 167 days on treatment. Steers in NW did not achieve similar expression levels even by 222 days on treatment, suggesting a blunted response even when fed a high-starch diet after weaning. High-starch feeding at an early age (EWS) triggers precocious and sustained adipogenesis, resulting in greater marbling. PMID:24516329

Central Role of the PPARγ Gene Network in Coordinating Beef Cattle Intramuscular Adipogenesis in Response to Weaning Age and Nutrition.

PubMed

Moisá, Sonia J; Shike, Daniel W; Faulkner, Dan B; Meteer, William T; Keisler, Duane; Loor, Juan J

2014-01-01

Adipogenic/lipogenic transcriptional networks regulating intramuscular fat deposition (IMF) in response to weaning age and dietary starch level were studied. The longissimus muscle (LM) of beef steers on an early weaning (141 days age) plus high-starch diet (EWS) or a normal weaning (NW, 222 days age) plus starch creep-feed diet (CFS) was biopsied at 0 (EW), 25, 50, 96 (NW), 167, and 222 (pre-slaughter) days. Expression patterns of 35 target genes were studied. From NW through slaughter, all steers received the same high-starch diet. In EWS steers the expression of PPARG, other adipogenic (CEBPA, ZFP423) and lipogenic (THRSP, SREBF1, INSIG1) activators, and several enzymes (FASN, SCD, ELOVL6, PCK1, DGAT2) that participate in the process of IMF increased gradually to a peak between 96 and 167 days on treatment. Steers in NW did not achieve similar expression levels even by 222 days on treatment, suggesting a blunted response even when fed a high-starch diet after weaning. High-starch feeding at an early age (EWS) triggers precocious and sustained adipogenesis, resulting in greater marbling.

Role of CD28/B7 costimulation in the dexamethasone-induced suppression of IFN-gamma.

PubMed

Agarwal, S K; Marshall, G D

2000-11-01

In vitro exposure of peripheral blood mononuclear cells (PBMC) to glucocorticoids (GC), at concentrations observed during psychologic stress, induces a shift in the human type 1/type 2 cytokine balance toward a type 2 cytokine response. The mechanisms involved in these cytokine alterations are unknown but likely include modulation of regulatory cytokines or the interaction between the antigen-presenting cell (APC) and T lymphocyte or both. The CD28/B7 costimulation pathway has been reported to modulate the type 1/type 2 cytokine balance and may contribute to the GC-associated cytokine alterations. Therefore, we sought to determine the effect of dexamethasone (Dex) on the expression and function of the human CD28/B7 costimulatory pathway and whether these alterations contribute to the Dex-induced type 1/type 2 cytokine alterations. Dex inhibited the expression of both CD80 and CD86 on THP-1 cells, a human acute monocytic leukemia cell line, as determined by flow cytometry. Dex also inhibited the expression of CD28 and CTLA-4 on phytohemagglutinin (PHA)-stimulated CD3+ T lymphocytes, which was attenuated by the addition of interleukin-12 (IL-12). Lastly, activation of CD28 with anti-CD28 antibody attenuated the Dex-induced decrease in interferon-gamma (IFN-gamma) production by anti-CD3 antibody-stimulated PBMC. These data suggest that Dex induces a modulation of the CD28/B7 costimulatory pathway that contributes to the shift in the type 1/type 2 cytokine balance toward a predominant type 2 cytokine response.

Cell Derived Microparticles in Gingival Crevicular Fluid from Periodontitis Patients with Type 2 Diabetes.

PubMed

Figueredo, Carlos Marcelo; Lira, Ronaldo; Sete, Manuela Rubim; Fischer, Ricardo Guimarães

2017-01-01

Cell-derived microparticles (MPs) have been described as vital contributors to the inflammatory process. However, its role in the periodontal disease pathogenesis remains unclear. Therefore, we aimed to detect the presence neutrophil (CD66b+) and platelet (CD41b+) derived microparticles in gingival crevicular fluid from individuals having periodontitis aggravated by type 2 diabetes. Twelve patients (56.2 ±7.2 yrs) with severe form of chronic periodontitis aggravated by type 2 diabetes were included. Clinical and metabolic data were gathered. Gingival crevicular fluid was collected using filter strips from deep and shallow sites. MPs were detected by flow cytometry according to their size (< 1 µm) and the expression of surface markers (CD66b for neutrophil-derived MPs and CD41b for platelet-derived MPs). All samples were positive for the antibodies. Median levels of CD66b+ MPs and CD41b+ MPs were, respectively, 3,677.0 (2,553.2 - 9,059.8) MP/µL and 520.7 (432.9 - 766.1) MP/µL in deep sites. In shallow sites, the corresponding values were 2,644.9 (1,451.5 - 3,858.9) MP/µL and 371.2 (287.2 - 692.7) MP/µL. There was no significant difference between deep and shallow sites (p>0.05). In conclusion, this study reported the presence of neutrophil and platelet derived microparticles in gingival crevicular fluid from individuals having severe periodontitis and type 2 diabetes.

Superconductivity of ternary silicide with the AlB(2)-type structure Sr(Ga(0.37),Si(0.63))(2).

PubMed

Imai, M; Abe, E; Ye, J; Nishida, K; Kimura, T; Honma, K; Abe, H; Kitazawa, H

2001-08-13

A ternary silicide Sr(Ga(0.37),Si(0.63))(2) was synthesized by a floating zone method. Electron diffraction and powder x-ray diffraction measurements indicate that the silicide has the AlB(2)-type structure with the lattice constants of a = 4.1427(6) A and c = 4.7998(9) A, where Si and Ga atoms are arranged in a chemically disordered honeycomb lattice and Sr atoms are inercalated between them. The silicide is isostructural with the high-temperature superconductor MgB(2) reported recently. Electrical resistivity and dc magnetization measurements revealed that it is a type-II superconductor with onset temperature of 3.5 K.

Early development of calcific aortic valve disease and left ventricular hypertrophy in a mouse model of combined dyslipidemia and type 2 diabetes mellitus.

PubMed

Le Quang, Khai; Bouchareb, Rihab; Lachance, Dominic; Laplante, Marc-André; El Husseini, Diala; Boulanger, Marie-Chloé; Fournier, Dominique; Fang, Xiang Ping; Avramoglu, Rita Kohen; Pibarot, Philippe; Deshaies, Yves; Sweeney, Gary; Mathieu, Patrick; Marette, André

2014-10-01

This study aimed to determine the potential impact of type 2 diabetes mellitus on left ventricular dysfunction and the development of calcified aortic valve disease using a dyslipidemic mouse model prone to developing type 2 diabetes mellitus. When compared with nondiabetic LDLr(-/-)/ApoB(100/100), diabetic LDLr(-/-)/ApoB(100/100)/IGF-II mice exhibited similar dyslipidemia and obesity but developed type 2 diabetes mellitus when fed a high-fat/sucrose/cholesterol diet for 6 months. LDLr(-/-)/ApoB(100/100)/IGF-II mice showed left ventricular hypertrophy versus C57BL6 but not LDLr(-/-)/ApoB(100/100) mice. Transthoracic echocardiography revealed significant reductions in both left ventricular systolic fractional shortening and diastolic function in high-fat/sucrose/cholesterol fed LDLr(-/-)/ApoB(100/100)/IGF-II mice when compared with LDLr(-/-)/ApoB(100/100). Importantly, we found that peak aortic jet velocity was significantly increased in LDLr(-/-)/ApoB(100/100)/IGF-II mice versus LDLr(-/-)/ApoB(100/100) animals on the high-fat/sucrose/cholesterol diet. Microtomography scans and Alizarin red staining indicated calcification in the aortic valves, whereas electron microscopy and energy dispersive x-ray spectroscopy further revealed mineralization of the aortic leaflets and the presence of inflammatory infiltrates in diabetic mice. Studies showed upregulation of hypertrophic genes (anp, bnp, b-mhc) in myocardial tissues and of osteogenic genes (spp1, bglap, runx2) in aortic tissues of diabetic mice. We have established the diabetes mellitus -prone LDLr(-/-)/ApoB(100/100)/IGF-II mouse as a new model of calcified aortic valve disease. Our results are consistent with the growing body of clinical evidence that the dysmetabolic state of type 2 diabetes mellitus contributes to early mineralization of the aortic valve and calcified aortic valve disease pathogenesis. © 2014 American Heart Association, Inc.

Gene Scanning of an Internalin B Gene Fragment Using High-Resolution Melting Curve Analysis as a Tool for Rapid Typing of Listeria monocytogenes

PubMed Central

Pietzka, Ariane T.; Stöger, Anna; Huhulescu, Steliana; Allerberger, Franz; Ruppitsch, Werner

2011-01-01

The ability to accurately track Listeria monocytogenes strains involved in outbreaks is essential for control and prevention of listeriosis. Because current typing techniques are time-consuming, cost-intensive, technically demanding, and difficult to standardize, we developed a rapid and cost-effective method for typing of L. monocytogenes. In all, 172 clinical L. monocytogenes isolates and 20 isolates from culture collections were typed by high-resolution melting (HRM) curve analysis of a specific locus of the internalin B gene (inlB). All obtained HRM curve profiles were verified by sequence analysis. The 192 tested L. monocytogenes isolates yielded 15 specific HRM curve profiles. Sequence analysis revealed that these 15 HRM curve profiles correspond to 18 distinct inlB sequence types. The HRM curve profiles obtained correlated with the five phylogenetic groups I.1, I.2, II.1, II.2, and III. Thus, HRM curve analysis constitutes an inexpensive assay and represents an improvement in typing relative to classical serotyping or multiplex PCR typing protocols. This method provides a rapid and powerful screening tool for simultaneous preliminary typing of up to 384 samples in approximately 2 hours. PMID:21227395

A2 to B Blood Type Incompatible Deceased Donor Kidney Transplantation in a Recipient Infected with the Human Immunodeficiency Virus: A Case Report.

PubMed

Forbes, R C; DeMers, A; Concepcion, B P; Moore, D R; Schaefer, H M; Shaffer, D

With the introduction of the Kidney Allocation System in the United States in December 2014, transplant centers can list eligible B blood type recipients for A2 organ offers. There have been no prior reports of ABO incompatible A2 to B deceased donor kidney transplantation in human immunodeficiency virus-positive (HIV+) recipients to guide clinicians on enrolling or performing A2 to B transplantations in HIV+ candidates. We are the first to report a case of A2 to B deceased donor kidney transplantation in an HIV+ recipient with good intermediate-term results. We describe an HIV+ 39-year-old African American man with end-stage renal disease who underwent A2 to B blood type incompatible deceased donor kidney transplantation. Prior to transplantation, he had an undetectable HIV viral load. The patient was unsensitized, with his most recent anti-A titer data being 1:2 IgG and 1:32 IgG/IgM. Induction therapy of basiliximab and methylprednisolone was followed by a postoperative regimen of plasma exchange, intravenous immunoglobulin, and rituximab with maintenance on tacrolimus, mycophenolate mofetil, and prednisone. He had delayed graft function without rejection on allograft biopsy. Nadir serum creatinine was 2.0 mg/dL. He continued to have an undetectable viral load on the same antiretroviral therapy adjusted for renal function. To our knowledge, this is the first report of A2 to B deceased donor kidney transplantation in an HIV+ recipient with good intermediate-term results, suggesting that A2 donor kidneys may be considered for transplantation into HIV+ B-blood type wait list candidates. Published by Elsevier Inc.

Investigation of the cardiomyocyte dysfunction in bradykinin type 2 receptor knockout mice.

PubMed

Roman-Campos, Danilo; Duarte, Hugo Leonardo; Gomes, Enéas Ricardo; Castro, Carlos Henrique; Guatimosim, Silvia; Natali, Antonio José; Almeida, Alvair Pinto; Pesquero, João Bosco; Pesquero, Jorge Luiz; Cruz, Jader Santos

2010-12-18

Bradykinin type 2 receptor (B(2)R) is the key component to trigger the intracellular signaling pathway in response to bradykinin under physiological conditions. The present study sought to investigate whether the B(2)R gene deletion will have an impact on myocardial function. Isolated cell shortening, patch-clamp technique, Western blot and confocal microscopy. Isolated cell shortening measurements showed significant reduction in B(2)R knockout (B(2)R(-/-)) left ventricular cardiac myocytes' shortening. Whole-cell recordings were used to study the electrophysiological aspects of the left ventricular B(2)R(-/-) cardiomyocytes. Results showed: 1) action potential lengthening; 2) unchanged inwardly rectifying K(+) current; 3) reduced transient outward K(+) (I(to)) and L-type Ca(2+) current densities; 5) changes in kinetic properties related to I(to) and I(Ca,L). In addition, transient sarcoplasmic reticulum (SR) Ca(2+) release was found to be smaller in B(2)R(-/-) cardiomyocytes. Importantly, evidence is provided that NO constitutive production is, at least in part, responsible for the reported electrophysiological modifications observed in cardiomyocytes from B(2)R(-/-) mice. Surprisingly, NO is not involved in the SR Ca(2+) release reduction as demonstrated in the present study. Taken together, our findings indicate that B(2)R plays a fundamental role in the regulation of cardiac function and Ca(2+) homeostasis, probably through a NO dependent pathway. These results may contribute to our understanding of the kinins participation in the control of cardiac function. Copyright © 2010 Elsevier Inc. All rights reserved.

A theoretical investigation of mixing thermodynamics, age-hardening potential, and electronic structure of ternary M11–xM2xB2 alloys with AlB2 type structure

PubMed Central

Alling, B.; Högberg, H.; Armiento, R.; Rosen, J.; Hultman, L.

2015-01-01

Transition metal diborides are ceramic materials with potential applications as hard protective thin films and electrical contact materials. We investigate the possibility to obtain age hardening through isostructural clustering, including spinodal decomposition, or ordering-induced precipitation in ternary diboride alloys. By means of first-principles mixing thermodynamics calculations, 45 ternary M11–xM2xB2 alloys comprising MiB2 (Mi = Mg, Al, Sc, Y, Ti, Zr, Hf, V, Nb, Ta) with AlB2 type structure are studied. In particular Al1–xTixB2 is found to be of interest for coherent isostructural decomposition with a strong driving force for phase separation, while having almost concentration independent a and c lattice parameters. The results are explained by revealing the nature of the electronic structure in these alloys, and in particular, the origin of the pseudogap at EF in TiB2, ZrB2, and HfB2. PMID:25970763

[Assessment of the hearing results in tympanoplasties with the use of palisade-technique].

PubMed

Wielgosz, Romuald; Mroczkowski, Edward

2006-01-01

The cartilage has been successfuly used in reconstructive ear surgery for more than one hundred years. Histologic study of autografts cartilage (tragal or conchal) showed good long-term preservation of cartilage cells. The aim of this paper is to assess the hearing results in tympanoplasties with the use of cartilage palisade technique. The retrospective analysis concerned 108 operated clinical cases. The cartilage palisade technique was performed in 28 tympanoplasties type I, 47 tympanoplasties type II, 21 tympanoplasties type III with columella and in 2 tympanoplasties type IV. Clinical assessment included otoscopy, test for eustachian tube ventilation, test with tuning fork, audiometry on a range 0,5, 1, 2 kHz and subjective evaluation based on questionaire. The Air Bone Gap (ABG) was noted as follows: < 10 dB among 67,8% of patients and 11-20 dB among 21,4% of patients in tympanoplasty type I. In tympanoplasty type II the ABG was responsively: < 10 dB - 80% patients, 11-20 dB - 10% patients. In the type III of tympanoplasty 40,4% of patients showed ABG < 10 dB and 42,5% of patients 11-20 dB. In the type III with columella we noted 15% patients with ABG < 10 dB and 65% of them with ABG 11-20 dB. The cartilage is a good autograft for reconstruction of the tympanic membrane, middle ear and the auditory wall because of stability and lack of secondary perforations. Long-term results in hearing are also satisfactory.

Preparation of A-type proanthocyanidin dimers from peanut skins and persimmon pulp and comparison of the antioxidant activity of A-type and B-type dimers.

PubMed

Dong, Xiao-qian; Zou, Bo; Zhang, Ying; Ge, Zhen-zhen; Du, Jing; Li, Chun-mei

2013-12-01

We have established a simple method for preparing large quantities of A-type dimers from peanut skin and persimmon for further structure-activity relationship study. Peanut skins were defatted with hexane and oligomeric proanthocyanidins were extracted from it with 20% of methanol, and the extract was fractionated with ethyl acetate. Persimmon tannin was extracted from persimmon with methanol acidified with 1% hydrochloric acid, after removing the sugar and small phenols, the high molecular weight persimmon tannin was partially cleaved with 6.25% hydrochloric acid in methanol. The ethyl acetate fraction from peanut skins and persimmon tannin cleaved products was chromatographed on AB-8 macroporous resin followed by Toyopearl HW-50F resin to yield about 378.3mg of A-type (epi)catechin (EC) dimer from 1 kg dry peanut skins and 34.3mg of A-type (epi)catechin-3-O-gallate (ECG) dimer and 37.7 mg of A-type (epi)gallocatechin-3-O-gallate (EGCG) dimer from 1 kg fresh persimmon fruit. The antioxidant properties of the A-type and B-type dimers were compared in five different assays, namely, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, 2,2-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical, hydroxyl radical, lipid peroxidation in mice liver homogenate and erythrocyte hemolysis in rat blood. Our results showed that both A-type and B-type dimers showed high antioxidant potency in a dose-dependent manner. In general, B-type dimers showed higher radical scavenging potency than A-type ones with the same subunits in aqueous systems. But in tissue or lipid systems, A-type dimers showed similar or even higher antioxidant potency than B-type ones. © 2013.

Origin and Dissemination of Chloroquine-Resistant Plasmodium falciparum with Mutant pfcrt Alleles in the Philippines

PubMed Central

Chen, Nanhua; Wilson, Danny W.; Pasay, Cielo; Bell, David; Martin, Laura B.; Kyle, Dennis; Cheng, Qin

2005-01-01

The pfcrt allelic type and adjacent microsatellite marker type were determined for 82 Plasmodium falciparum isolates from the Philippines. Mutant pfcrt allelic types P1a and P2a/P2b were dominant in different locations. Microsatellite analysis revealed that P2a/P2b evolved independently in the Philippines, while P1a shared common ancestry with Papua New Guinea chloroquine-resistant parasites. PMID:15855538

Association of ABO and Rh blood groups with type 2 diabetes mellitus.

PubMed

Meo, S A; Rouq, F A; Suraya, F; Zaidi, S Z

2016-01-01

The phenotypic "ABO" blood groups are inherited antigenic substances which are found on the surface of red blood cells in addition to other tissues. Certain hypothesis advocates that genetic predisposition like "ABO" blood group would be associated with occurrence of diseases including type 2 diabetes. This study aimed to investigate the potential association between "ABO" and "Rhesus" blood groups with type 2 diabetes. We identified 47 research documents in a data based search including ISI-Web of Science, EMBASE and PubMed. Literature was explored using the key terms including "ABO blood groups" "type 2 diabetes". Studies in which "ABO" blood types and diabetes mellitus were discussed included without restrictions of research documents, types, status and language of the publications. Finally, 15 publications which matched our criteria were included, and remaining studies were excluded. Blood group "B" was associated with high incidence of type 2 diabetes and blood group "O" has a minimum association with type 2 diabetes. Blood group "A" and "AB" were almost equally distributed in both diabetic and non-diabetic population. However, we were unable to find an association between "Rh+ve" and "Rh-ve" blood groups with type 2 diabetes. Subjects with blood group "B" are at high risk while individuals with blood group "O" are at low peril of evolving type 2 diabetes. It is suggested that subjects with blood group "B" should be closely monitored by physicians as these subjects have an increased risk of type 2 diabetes.

Applicability of Type A/B alcohol dependence in the general population.

PubMed

Tam, Tammy W; Mulia, Nina; Schmidt, Laura A

2014-05-01

This study examined the concurrent and predictive validity of Type A/B alcohol dependence in the general population-a typology developed in clinical populations to gauge severity of dependence. Data were drawn from Waves 1 and 2 of the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC). The sample included 1,172 alcohol-dependent drinkers at baseline who were reinterviewed three years later. Latent class analysis was used to derive Type A/B classification using variables replicating the original Type A/B typology. Predictive validity of the Type A/B classification was assessed by multivariable linear and logistic regressions. A two-class solution consistent with Babor's original Type A/B typology adequately fit the data. Type B alcoholics in the general population, compared to Type As, had higher alcohol severity and more co-occurring drug, mental, and physical health problems. In the absence of treatment services utilization, Type B drinkers had two times the odds of being alcohol dependent three years later. Among those who utilized alcohol treatment services, Type B membership was predictive of heavy drinking and drug dependence, but not alcohol dependence, three years later. Findings suggest that Type A/B classification is both generalizable to, and valid within, the US general population of alcohol dependent drinkers. Results highlight the value of treatment for mitigating the persistence of dependence among Type B alcoholics in the general population. Screening for markers of vulnerability to Type B dependence could be of clinical value for health care providers to determine appropriate intervention. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Multiplex real-time PCR for identification of canine parvovirus antigenic types.

PubMed

Kaur, Gurpreet; Chandra, Mudit; Dwivedi, P N; Narang, Deepti

2016-07-01

Canine parvovirus (CPV) is an important disease causing gastroenteritis and/or haemorrhagic gastroenteritis in dogs. There are four antigenic types of CPV reported worldwide viz. CPV 2, CPV 2a, CPV 2b and CPV 2c. The diagnosis of CPV with the identification of the antigen type responsible remains problematic. In the present study, identification as well as antigenic typing of CPV was done using a de novo multiplex real time PCR to combat the problem of antigenic type identification. From the study it could be concluded that the here developed multiplex real time PCR assay could be used for rapid detection of CPV as well as typing of its three antigenic types. Copyright © 2016 Elsevier B.V. All rights reserved.

Structure–activity correlations of variant forms of the B pentamer of Escherichia coli type II heat-labile enterotoxin LT-IIb with Toll-like receptor 2 binding

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cody, Vivian, E-mail: cody@hwi.buffalo.edu; University at Buffalo, 700 Ellicott Street, Buffalo, NY 14203; Pace, Jim

2012-12-01

Structural data for the S74D variant of the pentameric B subunit of type II heat-labile enterotoxin of Escherichia coli reveal a smaller pore opening that may explain its reduced Toll-like receptor binding affinity compared to that of the wild type enterotoxin. The explanation for the enhanced Toll-like receptor binding affinity of the S74A variant is more complex than simply being attributed to the pore opening. The pentameric B subunit of the type II heat-labile enterotoxin of Escherichia coli (LT-IIb-B{sub 5}) is a potent signaling molecule capable of modulating innate immune responses. It has previously been shown that LT-IIb-B{sub 5}, butmore » not the LT-IIb-B{sub 5} Ser74Asp variant [LT-IIb-B{sub 5}(S74D)], activates Toll-like receptor (TLR2) signaling in macrophages. Consistent with this, the LT-IIb-B{sub 5}(S74D) variant failed to bind TLR2, in contrast to LT-IIb-B{sub 5} and the LT-IIb-B{sub 5} Thr13Ile [LT-IIb-B{sub 5}(T13I)] and LT-IIb-B{sub 5} Ser74Ala [LT-IIb-B{sub 5}(S74A)] variants, which displayed the highest binding activity to TLR2. Crystal structures of the Ser74Asp, Ser74Ala and Thr13Ile variants of LT-IIb-B{sub 5} have been determined to 1.90, 1.40 and 1.90 Å resolution, respectively. The structural data for the Ser74Asp variant reveal that the carboxylate side chain points into the pore, thereby reducing the pore size compared with that of the wild-type or the Ser74Ala variant B pentamer. On the basis of these crystallographic data, the reduced TLR2-binding affinity of the LT-IIb-B{sub 5}(S74D) variant may be the result of the pore of the pentamer being closed. On the other hand, the explanation for the enhanced TLR2-binding activity of the LT-IIb-B{sub 5}(S74A) variant is more complex as its activity is greater than that of the wild-type B pentamer, which also has an open pore as the Ser74 side chain points away from the pore opening. Data for the LT-IIb-B{sub 5}(T13I) variant show that four of the five variant side chains point to the outside surface of the pentamer and one residue points inside. These data are consistent with the lack of binding of the LT-IIb-B{sub 5}(T13I) variant to GD1a ganglioside.« less

Sequence analysis of chloroplast chlB gene of medicinal Ephedra species and its application to authentication of Ephedra Herb.

PubMed

Guo, Yahong; Tsuruga, Ayako; Yamaguchi, Shigeharu; Oba, Koji; Iwai, Kasumi; Sekita, Setsuko; Mizukami, Hajime

2006-06-01

Chloroplast chlB gene encoding subunit B of light-independent protochlorophyllide reductase was amplified from herbarium and crude drug specimens of Ephedra sinica, E. intermedia, E. equisetina, and E. przewalskii. Sequence comparison of the chlB gene indicated that all the E. sinica specimens have the same sequence type (Type S) distinctive from other species, while there are two sequence types (Type E1 and Type E2) in E. equisetina. E. intermedia and E. prezewalskii revealed an identical sequence type (Type IP). E. sinica was also identified by digesting the chlB fragment with Bcl I. A novel method for DNA authentication of Ephedra Herb based on the sequences of the chloroplast chlB gene and internal transcribed spacer of nuclear rRNA genes was developed and successfully applied for identification of the crude drugs obtained in the Chinese market.

Role of thin descending limb urea transport in renal urea handling and the urine concentrating mechanism

PubMed Central

Lei, Tianluo; Zhou, Lei; Layton, Anita T.; Zhou, Hong; Zhao, Xuejian; Bankir, Lise

2011-01-01

Urea transporters UT-A2 and UT-B are expressed in epithelia of thin descending limb of Henle's loop and in descending vasa recta, respectively. To study their role and possible interaction in the context of the urine concentration mechanism, a UT-A2 and UT-B double knockout (UT-A2/B knockout) mouse model was generated by targeted deletion of the UT-A2 promoter in embryonic stem cells with UT-B gene knockout. The UT-A2/B knockout mice lacked detectable UT-A2 and UT-B transcripts and proteins and showed normal survival and growth. Daily urine output was significantly higher in UT-A2/B knockout mice than that in wild-type mice and lower than that in UT-B knockout mice. Urine osmolality in UT-A2/B knockout mice was intermediate between that in UT-B knockout and wild-type mice. The changes in urine osmolality and flow rate, plasma and urine urea concentration, as well as non-urea solute concentration after an acute urea load or chronic changes in protein intake suggested that UT-A2 plays a role in the progressive accumulation of urea in the inner medulla. These results suggest that in wild-type mice UT-A2 facilitates urea absorption by urea efflux from the thin descending limb of short loops of Henle. Moreover, UT-A2 deletion in UT-B knockout mice partially remedies the urine concentrating defect caused by UT-B deletion, by reducing urea loss from the descending limbs to the peripheral circulation; instead, urea is returned to the inner medulla through the loops of Henle and the collecting ducts. PMID:21849488

Role of thin descending limb urea transport in renal urea handling and the urine concentrating mechanism.

PubMed

Lei, Tianluo; Zhou, Lei; Layton, Anita T; Zhou, Hong; Zhao, Xuejian; Bankir, Lise; Yang, Baoxue

2011-12-01

Urea transporters UT-A2 and UT-B are expressed in epithelia of thin descending limb of Henle's loop and in descending vasa recta, respectively. To study their role and possible interaction in the context of the urine concentration mechanism, a UT-A2 and UT-B double knockout (UT-A2/B knockout) mouse model was generated by targeted deletion of the UT-A2 promoter in embryonic stem cells with UT-B gene knockout. The UT-A2/B knockout mice lacked detectable UT-A2 and UT-B transcripts and proteins and showed normal survival and growth. Daily urine output was significantly higher in UT-A2/B knockout mice than that in wild-type mice and lower than that in UT-B knockout mice. Urine osmolality in UT-A2/B knockout mice was intermediate between that in UT-B knockout and wild-type mice. The changes in urine osmolality and flow rate, plasma and urine urea concentration, as well as non-urea solute concentration after an acute urea load or chronic changes in protein intake suggested that UT-A2 plays a role in the progressive accumulation of urea in the inner medulla. These results suggest that in wild-type mice UT-A2 facilitates urea absorption by urea efflux from the thin descending limb of short loops of Henle. Moreover, UT-A2 deletion in UT-B knockout mice partially remedies the urine concentrating defect caused by UT-B deletion, by reducing urea loss from the descending limbs to the peripheral circulation; instead, urea is returned to the inner medulla through the loops of Henle and the collecting ducts.

Laboratory diagnosis of von Willebrand disease type 1/2E (2A subtype IIE), type 1 Vicenza and mild type 1 caused by mutations in the D3, D4, B1-B3 and C1-C2 domains of the von Willebrand factor gene. Role of von Willebrand factor multimers and the von Willebrand factor propeptide/antigen ratio.

PubMed

Gadisseur, Alain; Berneman, Zwi; Schroyens, Wilfried; Michiels, Jan Jacques

2009-01-01

Autosomal dominant von Willebrand disease (VWD) type 1/2E is a quantitative/qualitative defect in the von Willebrand factor (VWF) caused by heterozygous cysteine and non-cysteine mutations in the D3 domain of the VWF gene and results in a secretion-multimerization-clearance defect in mutant VWF with the loss of large VWF multimers not due to proteolysis. The multimers of patients with dominant VWD type 1/2E due to mutations in the D3 domain show an aberrant triplet structure with lack of outer bands but with pronounced inner bands of the triplet structure combined with a relative decrease in large multimers reflecting heterozygosity for multimerization defects. There is a good response to desmopressin (DDAVP) followed by rapid clearance of VWF:antigen (Ag), factor VIII coagulant activity (FVIII:C) and VWF:ristocetin cofactor activity (RCo) as the main cause of VWD type 1 or 2 with typical 2E multimeric pattern (VWD type 1/2E). Cysteine mutations in the D3 domains (C1130, C1149 and C1190) show pronounced features of VWD 1/2E with the relative loss of large and relative increase in small VWF multimers with abnormal triplet structure in heterozygotes. Such abnormalities are less pronounced in patients with a milder form of VWD type 1 due to non-cysteine mutations W1144G, T1156M and W1120S in the D3 domain. VWD type 1 Vicenza is caused by the R1205H mutation in the D3 domain and characterized by equally low levels of FVIII:C, VWF:Ag and VWF:RCo. The response to DDAVP in VWD Vicenza is good for FVIII:C, VWF:Ag and VWF:RCo, which is followed by a rapid clearance in less than a few hours of FVIII:C and VWF parameters. The ratios for FVIII:C/VWF:Ag, VWF:RCo/Ag and VWF:CB/Ag remain normal before and after DDAVP indicating that VWD Vicenza clearly differs from VWD type 1, 1/2E and 2M. A new set of missense mutations in D4, B1-B3 and C1-C2 domains has been discovered as the cause of a mild VWD type 1 secretion defect with normal VWF multimers or smeary VWF multimeric pattern. Cysteine mutations in exons 38, 40, 42 and 43 (D4, B1-B3 and C1 domain), show smeary patterns (either smf or sm), with the presence of large VWF multimers and a laboratory phenotype of mild VWD type 1 with variable penetrance of bleeding manifestations. Recent studies showed that the ratio of VWF propeptide (pp) to VWF:Ag can be used to predict a shorter than normal half-life for VWF:Ag. There is a strong inverse correlation between rapid clearance of VWF:Ag after DDAVP and increased VWFpp/Ag ratios >10 in VWD type 1 Vicenza, and >2 in VWD type 1/2E but normal or slightly increased (1-<2) VWFpp/Ag ratios in mild-type VWD due to nonsense or missense mutations in the D1, D2, D4, B and C domains. Copyright (c) 2009 S. Karger AG, Basel.

10′(Z),13′(E)-Heptadecadienylhydroquinone Inhibits Swarming and Virulence Factors and Increases Polymyxin B Susceptibility in Proteus mirabilis

PubMed Central

Wang, Won-Bo; Yuan, Yu-Han; Hsueh, Po-Ren; Liaw, Shwu-Jen

2012-01-01

In this study, we demonstrated that 10′(Z), 13′(E)-heptadecadienylhydroquinone (HQ17-2), isolated from the lacquer tree, could decrease swarming motility and hemolysin activity but increase polymyxin B (PB) susceptibilityof Proteus mirabilis which is intrinsically highly-resistant to PB. The increased PB susceptibility induced by HQ17-2 was also observed in clinical isolates and biofilm-grown cells. HQ17-2 could inhibit swarming in the wild-type and rppA mutant but not in the rcsB mutant, indicating that HQ17-2 inhibits swarming through the RcsB-dependent pathway, a two-component signaling pathway negatively regulating swarming and virulence factor expression. The inhibition of hemolysin activity by HQ17-2 is also mediated through the RcsB-dependent pathway, because HQ17-2 could not inhibit hemolysin activity in the rcsB mutant. Moreover, the finding that HQ17-2 inhibits the expression of flhDC gene in the wild-type and rcsB-complemented strain but not in the rcsB mutant supports the notion. By contrast, HQ17-2 could increase PB susceptibility in the wild-type and rcsB mutant but not in the rppA mutant, indicating that HQ17-2 increases PB susceptibility through the RppA-dependent pathway, a signaling pathway positively regulating PB resistance. In addition, HQ17-2 could inhibit the promoter activities of rppA and pmrI, a gene positively regulated by RppA and involved in PB resistance, in the wild-type but not in the rppA mutant. The inhibition of rppA and pmrI expression caused lipopolysaccharide purified from HQ17-2-treated cells to have higher affinity for PB. Altogether, this study uncovers new biological effects of HQ17-2 and provides evidence for the potential of HQ17-2 in clinical applications. PMID:23029100

Characterization of dermatoglyphics in PHOX2B-confirmed congenital central hypoventilation syndrome.

PubMed

Todd, Emily S; Scott, Nicole M; Weese-Mayer, Debra E; Weinberg, Seth M; Berry-Kravis, Elizabeth M; Silvestri, Jean M; Kenny, Anna S; Hauptman, Susan A; Zhou, Lili; Marazita, Mary L

2006-08-01

Individuals with congenital central hypoventilation syndrome have characteristic variants in the PHOX2B gene (primarily polyalanine expansion mutations). The PHOX2B gene acts as a transcriptional activator in the promotion of pan-neuronal differentiation in the autonomic nervous system during early embryologic development, with a primary role in the sympathetic noradrenergic phenotype in vertebrates. Because sympathetic innervation has been hypothesized to affect the development of dermatoglyphic pattern types, we hypothesized that individuals with PHOX2B-confirmed congenital central hypoventilation syndrome would have characteristic dermatoglyphic patterning and that the dermatoglyphic phenotype would be related to the disease-defining PHOX2B genotype. Dermatoglyphic pattern type frequency, left/right symmetry, and genotype/phenotype correlation were assessed for 33 individuals with PHOX2B-confirmed congenital central hypoventilation syndrome and compared with published control data. Dermatoglyphic pattern type frequencies were altered in congenital central hypoventilation syndrome cases versus controls. In particular, there was an increase of arches in females and ulnar loops in males, with the largest differences for the left hand and for individuals with both congenital central hypoventilation syndrome and Hirschsprung disease. Dissimilarity scores between the congenital central hypoventilation syndrome and congenital central hypoventilation syndrome + Hirschsprung disease cases were not significantly different, nor were dissimilarity scores between all of the female and all of the male cases. No significant association was found between the number of polyalanine repeats in the PHOX2B genotypic category and dermatoglyphic pattern frequencies in the congenital central hypoventilation syndrome study groups. These results represent the first report describing specific dermatoglyphic patterning in congenital central hypoventilation syndrome and suggest a relationship between PHOX2B and the expression of dermatoglyphic pattern types. An expanded congenital central hypoventilation syndrome data set to include the full spectrum of PHOX2B mutations is necessary to further delineate the role of PHOX2B in dermatoglyphic patterning.

Immunogenicity and safety evaluation of bivalent types 1 and 3 oral poliovirus vaccine by comparing different poliomyelitis vaccination schedules in China: A randomized controlled non-inferiority clinical trial

PubMed Central

Qiu, Jingjun; Yang, Yunkai; Huang, Lirong; Wang, Ling; Jiang, Zhiwei; Gong, Jian; Wang, Wei; Wang, Hongyan; Guo, Shaohong; Li, Chanjuan; Wei, Shuyuan; Mo, Zhaojun; Xia, Jielai

2017-01-01

ABSTRACT Background: The type 2 component of the oral poliovirus vaccine is targeted for global withdrawal through a switch from the trivalent oral poliovirus vaccine (tOPV) to a bivalent oral poliovirus vaccine (bOPV). The switch is intended to prevent paralytic polio caused by circulating vaccine-derived poliovirus type 2. We aimed to assess the immunogenicity and safety profile of 6 vaccination schedules with different sequential doses of inactivated poliovirus vaccine (IPV), tOPV, or bOPV. Methods: A randomized controlled trial was conducted in China in 2015. Healthy newborn babies randomly received one of the following 6 vaccination schedules: cIPV-bOPV-bOPV(I-B-B), cIPV-tOPV-tOPV(I-T-T), cIPV-cIPV-bOPV(I-I-B), cIPV-cIPV-tOPV(I-I-T), cIPV-cIPV-cIPV(I-I-I), or tOPV-tOPV-tOPV(T-T-T). Doses were administered sequentially at 4–6 week intervals after collecting baseline blood samples. Patients were proactively followed up for observation of adverse events after the first dose and 30 days after all doses. The primary study objective was to investigate the immunogenicity and safety profile of different vaccine schedules, evaluated by seroconversion, seroprotection and antibody titer against poliovirus types 1, 2, and 3 in the per-protocol population. Results: Of 600 newborn babies enrolled, 504 (84.0%) were included in the per-protocol population. For type 1 poliovirus, the differences in the seroconversion were 1.17% (95% CI = −2.74%, 5.08%) between I-B-B and I-T-T and 0.00% (95% CI: −6.99%, 6.99%) between I-I-B and I-I-T; for type 3 poliovirus, differences in the seroconversion were 3.49% (95% CI: −1.50%, 8.48%) between I-B-B and I-T-T and −2.32% (95% CI: −5.51%, 0.86%) between I-I-B and I-I-T. The non-inferiority conclusion was achieved in both poliovirus type 1 and 3 with the margin of −10%. Of 24 serious adverse events reported, no one was vaccine-related. Conclusions: The vaccination schedules with bOPV followed by one or 2 doses of IPV were recommended to substitute for vaccinations involving tOPV without compromising the immunogenicity and safety in the Chinese population. The findings will be essential for policy formulation by national and global authorities to facilitate polio elimination. PMID:28362135

Monitoring the Interaction between β2-Microglobulin and the Molecular Chaperone αB-crystallin by NMR and Mass Spectrometry

PubMed Central

Esposito, Gennaro; Garvey, Megan; Alverdi, Vera; Pettirossi, Fabio; Corazza, Alessandra; Fogolari, Federico; Polano, Maurizio; Mangione, P. Patrizia; Giorgetti, Sofia; Stoppini, Monica; Rekas, Agata; Bellotti, Vittorio; Heck, Albert J. R.; Carver, John A.

2013-01-01

The interaction at neutral pH between wild-type and a variant form (R3A) of the amyloid fibril-forming protein β2-microglobulin (β2m) and the molecular chaperone αB-crystallin was investigated by thioflavin T fluorescence, NMR spectroscopy, and mass spectrometry. Fibril formation of R3Aβ2m was potently prevented by αB-crystallin. αB-crystallin also prevented the unfolding and nonfibrillar aggregation of R3Aβ2m. From analysis of the NMR spectra collected at various R3Aβ2m to αB-crystallin molar subunit ratios, it is concluded that the structured β-sheet core and the apical loops of R3Aβ2m interact in a nonspecific manner with the αB-crystallin. Complementary information was derived from NMR diffusion coefficient measurements of wild-type β2m at a 100-fold concentration excess with respect to αB-crystallin. Mass spectrometry acquired in the native state showed that the onset of wild-type β2m oligomerization was effectively reduced by αB-crystallin. Furthermore, and most importantly, αB-crystallin reversibly dissociated β2m oligomers formed spontaneously in aged samples. These results, coupled with our previous studies, highlight the potent effectiveness of αB-crystallin in preventing β2m aggregation at the various stages of its aggregation pathway. Our findings are highly relevant to the emerging view that molecular chaperone action is intimately involved in the prevention of in vivo amyloid fibril formation. PMID:23645685

7 CFR 3052.520 - Major program determination.

Code of Federal Regulations, 2011 CFR

2011-01-01

... shall be labeled Type A programs. Type A programs are defined as Federal programs with Federal awards... Federal awards expended exceed $10 billion. (2) Federal programs not labeled Type A under paragraph (b)(1) of this section shall be labeled Type B programs. (3) The inclusion of large loan and loan guarantees...

B1 to B2 structural phase transition in LiF under pressure

NASA Astrophysics Data System (ADS)

Jain, Aayushi; Dixit, R. C.

2018-05-01

In the last few decades the alkali halides emerged as crystals with useful applications and their high-pressure behaviour is the most intensively studied subject in high-pressure physics/chemistry, material science, and geosciences. Most alkali halides follow the B1 (NaCl-type)→B2 (CsCl-type) phase-transition route under pressure. In the present paper, we have investigated the characteristics of structural phase transition that occurred in Lithium Florid compound under high pressure. The transition pressure of B1-B2 was calculated using an effective interionic interaction potential (EIOP). The changes of the characteristics of crystals like, Gibbs free energy, cohesive energy, volume collapse, and lattice constant are calculated for the B1 and B2 structures. These data were compared with the available experimental and theoretical data.

Outer membrane proteins from rough strains of four Brucella species.

PubMed Central

Santos, J M; Verstreate, D R; Perera, V Y; Winter, A J

1984-01-01

Outer membrane proteins from 15 rough strains of Brucella abortus, B. ovis, B. canis, and B. melitensis were extracted with a dipolar detergent, and outer membrane proteins from selected strains were purified by anion exchange chromatography and gel filtration (Verstreate et al., Infect. Immun. 35:979-989, 1982). Outer membrane proteins produced two types of profiles on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. One type, demonstrated by B. abortus, B. ovis, and B. canis strains, contained the three predominant protein groups present in smooth B. abortus strains (Verstreate et al., Infect. Immun. 35:979-989, 1982): groups 1, 2 (porin [Douglas et al., Infect. Immun. 44:16-21]), and 3. B. melitensis strains demonstrated the second profile type, in which there was an additional band between groups 1 and 2. The relative proportion of porin was considerably lower in B. ovis, B. canis, and B. melitensis than in B. abortus. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis profiles could be used to distinguish B. abortus and B. melitensis from each other and from B. canis and B. ovis. The amino acid compositions of groups 2 and 3 from rough strains of B. abortus, B. canis, and B. melitensis were similar to those of corresponding proteins from smooth B. abortus strains. Zwittergent-soluble fractions from most rough strains contained antigen [b], which cross-reacted with group 2 from smooth B. abortus strains, and antigens [c] and [d], which cross-reacted with group 3 from smooth B. abortus strains. Antigen [a], shared by groups 2 and 3 (D. R. Verstreate and A. J. Winter, Infect. Immun. 46:182-187, 1984), was detected in most rough strains. None of these antigens were related to either rough or smooth lipopolysaccharide. Images PMID:6480106

Cladielloides A and B: New Eunicellin-Type Diterpenoids from an Indonesian Octocoral Cladiella sp

PubMed Central

Chen, Yung-Husan; Tai, Chia-Ying; Hwang, Tsong-Long; Weng, Ching-Feng; Li, Jan-Jung; Fang, Lee-Shing; Wang, Wei-Hsien; Wu, Yang-Chang; Sung, Ping-Jyun

2010-01-01

Two new eunicellin-type diterpenoids, cladielloides A (1) and B (2), which were found to possess a 2-hydroxybutyroxy group in their structures, were isolated from an Indonesian octocoral identified as Cladiella sp. The structures of eunicellins 1 and 2 were elucidated by spectroscopic methods. Cladielloide B (2) exhibited moderate cytotoxicity toward CCRF-CEM tumor cells and this compound displayed significant inhibitory effects on superoxide anion generation and elastase release by human neutrophils. PMID:21339957

Kingella kingae expresses four structurally distinct polysaccharide capsules that differ in their correlation with invasive disease

DOE Office of Scientific and Technical Information (OSTI.GOV)

Starr, Kimberly F.; Porsch, Eric A.; Seed, Patrick C.

Kingella kingae is an encapsulated gram-negative organism that is a common cause of osteoarticular infections in young children. In earlier work, we identified a glycosyltransferase gene called csaA that is necessary for synthesis of the [3)-β-GalpNAc-(1→5)-β-Kdop-(2→] polysaccharide capsule (type a) in K. kingae strain 269–492. In the current study, we analyzed a large collection of invasive and carrier isolates from Israel and found that csaA was present in only 47% of the isolates. Further examination of this collection using primers based on the sequence that flanks csaA revealed three additional gene clusters (designated the csb, csc, and csd loci), allmore » encoding predicted glycosyltransferases. The csb locus contains the csbA, csbB, and csbC genes and is associated with a capsule that is a polymer of [6)-α-GlcpNAc-(1→5)-β-(8-OAc)Kdop-(2→] (type b). The csc locus contains the cscA, cscB, and cscC genes and is associated with a capsule that is a polymer of [3)-β-Ribf-(1→2)-β-Ribf-(1→2)-β-Ribf-(1→4)-β-Kdop-(2→] (type c). The csd locus contains the csdA, csdB, and csdC genes and is associated with a capsule that is a polymer of [P-(O→3)[β-Galp-(1→4)]-β-GlcpNAc-(1→3)-α-GlcpNAc-1-] (type d). Introduction of the csa, csb, csc, and csd loci into strain KK01Δcsa, a strain 269–492 derivative that lacks the native csaA gene, was sufficient to produce the type a capsule, type b capsule, type c capsule, and type d capsule, respectively, indicating that these loci are solely responsible for determining capsule type in K. kingae. Further analysis demonstrated that 96% of the invasive isolates express either the type a or type b capsule and that a disproportionate percentage of carrier isolates express the type c or type d capsule. Lastly, these results establish that there are at least four structurally distinct K. kingae capsule types and suggest that capsule type plays an important role in promoting K. kingae invasive disease« less

Kingella kingae expresses four structurally distinct polysaccharide capsules that differ in their correlation with invasive disease

DOE PAGES

Starr, Kimberly F.; Porsch, Eric A.; Seed, Patrick C.; ...

2016-10-19

Kingella kingae is an encapsulated gram-negative organism that is a common cause of osteoarticular infections in young children. In earlier work, we identified a glycosyltransferase gene called csaA that is necessary for synthesis of the [3)-β-GalpNAc-(1→5)-β-Kdop-(2→] polysaccharide capsule (type a) in K. kingae strain 269–492. In the current study, we analyzed a large collection of invasive and carrier isolates from Israel and found that csaA was present in only 47% of the isolates. Further examination of this collection using primers based on the sequence that flanks csaA revealed three additional gene clusters (designated the csb, csc, and csd loci), allmore » encoding predicted glycosyltransferases. The csb locus contains the csbA, csbB, and csbC genes and is associated with a capsule that is a polymer of [6)-α-GlcpNAc-(1→5)-β-(8-OAc)Kdop-(2→] (type b). The csc locus contains the cscA, cscB, and cscC genes and is associated with a capsule that is a polymer of [3)-β-Ribf-(1→2)-β-Ribf-(1→2)-β-Ribf-(1→4)-β-Kdop-(2→] (type c). The csd locus contains the csdA, csdB, and csdC genes and is associated with a capsule that is a polymer of [P-(O→3)[β-Galp-(1→4)]-β-GlcpNAc-(1→3)-α-GlcpNAc-1-] (type d). Introduction of the csa, csb, csc, and csd loci into strain KK01Δcsa, a strain 269–492 derivative that lacks the native csaA gene, was sufficient to produce the type a capsule, type b capsule, type c capsule, and type d capsule, respectively, indicating that these loci are solely responsible for determining capsule type in K. kingae. Further analysis demonstrated that 96% of the invasive isolates express either the type a or type b capsule and that a disproportionate percentage of carrier isolates express the type c or type d capsule. Lastly, these results establish that there are at least four structurally distinct K. kingae capsule types and suggest that capsule type plays an important role in promoting K. kingae invasive disease« less

Prevalence of Obesity and Its Influence on Achievement of Cardiometabolic Therapeutic Goals in Chinese Type 2 Diabetes Patients: An Analysis of the Nationwide, Cross-Sectional 3B Study.

PubMed

Zhou, Xianghai; Ji, Linong; Ran, Xingwu; Su, Benli; Ji, Qiuhe; Pan, Changyu; Weng, Jianping; Ma, Changsheng; Hao, Chuanming; Zhang, Danyi; Hu, Dayi

2016-01-01

There are few data on the prevalence of obesity and its influence on achieving blood glucose, blood pressure, and blood lipid (3B) goals in Chinese type 2 diabetes outpatients. Patient demographic data, anthropometric measurements, medications, and blood glucose and lipid profiles of 24,512 type 2 diabetes patients from a large, geographically diverse study (CCMR-3B) were analyzed. Using cut-points for body mass index (BMI) and waist circumference (WC) recommended by the Working Group on Obesity in China, overweight and obesity were defined as BMIs of 24-27.9 kg/m2 and ≥28.0 kg/m2. Central obesity was defined as a waist circumference ≥80 cm in women and ≥85 cm in men. The 3B therapeutic goals were HbA1c<7.0%, BP<140/90 mmHg and LDL-C<2.6 mmol/L. Overall, 43.0% of type 2 diabetes patients were overweight and 16.7% were obese; 13.3% of overweight and and 10.1% of obese patients achieved all the 3B target goals. Overweight or obese patients were less likely to achieve 3B goals than those with normal BMIs. More than a half the overweight or obese patients (69.6%) were centrally obese. Patients with abdominal obesity were less likely to achieve cardiometabolic targets than those without abdominal obesity. In multivariate logistic regression analysis, female, higher BMI and waist circumference, smoking, drinking, sedentary lifestyle, and longer diabetes duration were significantly correlated with failure to achieve 3B control goals. Obesity is highly prevalent and associated with poor 3B control in Chinese type 2 diabetes patients. In clinical practice, more attention and resources should focus on weight loss for such patients.

Efficacy of an inactivated feline panleucopenia virus vaccine against a canine parvovirus isolated from a domestic cat.

PubMed

Gamoh, K; Senda, M; Inoue, Y; Itoh, O

2005-09-03

Canine parvovirus type 2a (CPV-2a) and type 2b (CPV-2b) have recently been isolated from cats throughout the world, and CPV-2b strain FP84 has been reported to be virulent in domestic cats. Although live feline panleucopenia virus (FPLV) vaccines protect domestic cats from CPV infection, the efficacy of inactivated FPLV vaccines has not been established. In this study, two domestic cats were vaccinated with a commercial inactivated FPLV vaccine and challenged with CPV-2b strain FP84 isolated from a domestic cat. The cats were protected against CPV-2b strain FP84 infection and their clinical signs were suppressed, although the two unvaccinated cats showed the typical clinical signs of parvovirus infection.

Inactivated poliovirus vaccine given alone or in a sequential schedule with bivalent oral poliovirus vaccine in Chilean infants: a randomised, controlled, open-label, phase 4, non-inferiority study.

PubMed

O'Ryan, Miguel; Bandyopadhyay, Ananda S; Villena, Rodolfo; Espinoza, Mónica; Novoa, José; Weldon, William C; Oberste, M Steven; Self, Steve; Borate, Bhavesh R; Asturias, Edwin J; Clemens, Ralf; Orenstein, Walter; Jimeno, José; Rüttimann, Ricardo; Costa Clemens, Sue Ann

2015-11-01

Bivalent oral poliovirus vaccine (bOPV; types 1 and 3) is expected to replace trivalent OPV (tOPV) globally by April, 2016, preceded by the introduction of at least one dose of inactivated poliovirus vaccine (IPV) in routine immunisation programmes to eliminate vaccine-associated or vaccine-derived poliomyelitis from serotype 2 poliovirus. Because data are needed on sequential IPV-bOPV schedules, we assessed the immunogenicity of two different IPV-bOPV schedules compared with an all-IPV schedule in infants. We did a randomised, controlled, open-label, non-inferiority trial with healthy, full-term (>2·5 kg birthweight) infants aged 8 weeks (± 7 days) at six well-child clinics in Santiago, Chile. We used supplied lists to randomly assign infants (1:1:1) to receive three polio vaccinations (IPV by injection or bOPV as oral drops) at age 8, 16, and 24 weeks in one of three sequential schedules: IPV-bOPV-bOPV, IPV-IPV-bOPV, or IPV-IPV-IPV. We did the randomisation with blocks of 12 stratified by study site. All analyses were done in a masked manner. Co-primary outcomes were non-inferiority of the bOPV-containing schedules compared with the all-IPV schedule for seroconversion (within a 10% margin) and antibody titres (within two-thirds log2 titres) to poliovirus serotypes 1 and 3 at age 28 weeks, analysed in the per-protocol population. Secondary outcomes were seroconversion and titres to serotype 2 and faecal shedding for 4 weeks after a monovalent OPV type 2 challenge at age 28 weeks. Safety analyses were done in the intention-to-treat population. This trial is registered with ClinicalTrials.gov, number NCT01841671, and is closed to new participants. Between April 25 and August 1, 2013, we assigned 570 infants to treatment: 190 to IPV-bOPV-bOPV, 192 to IPV-IPV-bOPV, and 188 to IPV-IPV-IPV. 564 (99%) were vaccinated and included in the intention-to-treat cohort, and 537 (94%) in the per-protocol analyses. In the IPV-bOPV-bOPV, IPV-IPV-bOPV, and IPV-IPV-IPV groups, respectively, the proportions of children with seroconversion to type 1 poliovirus were 166 (98·8%) of 168, 95% CI 95·8-99·7; 178 (100%), 97·9-100·0; and 175 (100%), 97·9-100·0. Proportions with seroconvsion to type 3 poliovirus were 163 (98·2%) of 166, 94·8-99·4; 177 (100%), 97·9-100·0, and 172 (98·9%) of 174, 95·9-99·7. Non-inferiority was thus shown for the bOPV-containing schedules compared with the all-IPV schedule, with no significant differences between groups. In the IPV-bOPV-bOPV, IPV-IPV-bOPV, and IPV-IPV-IPV groups, respectively, the proportions of children with seroprotective antibody titres to type 1 poliovirus were 168 (98·8%) of 170, 95% CI 95·8-99·7; 181 (100%), 97·9-100·0; and 177 (100%), 97·9-100·0. Proportions to type 3 poliovirus were 166 (98·2%) of 169, 94·9-99·4; 180 (100%), 97·9-100·0; and 174 (98·9%) of 176, 96·0-99·7. Non-inferiority comparisons could not be done for this outcome because median titres for the groups receiving OPV were greater than the assay's upper limit of detection (log2 titres >10·5). The proportions of children seroconverting to type 2 poliovirus in the IPV-bOPV-bOPV, IPV-IPV-bOPV, and IPV-IPV-IPV groups, respectively, were 130 (77·4%) of 168, 95% CI 70·5-83·0; 169 (96·0%) of 176, 92·0-98·0; and 175 (100%), 97·8-100. IPV-bOPV schedules resulted in almost a 0·3 log reduction of type 2 faecal shedding compared with the IPV-only schedule. No participants died during the trial; 81 serious adverse events were reported, of which one was thought to be possibly vaccine-related (intestinal intussusception). Seroconversion rates against polioviruses types 1 and 3 were non-inferior in sequential schedules containing IPV and bOPV, compared with an all-IPV schedule, and proportions of infants with protective antibodies were high after all three schedules. One or two doses of bOPV after IPV boosted intestinal immunity for poliovirus type 2, suggesting possible cross protection. Additionally, there was evidence of humoral priming for type 2 from one dose of IPV. Our findings could give policy makers flexibility when choosing a vaccination schedule, especially when trying to eliminate vaccine-associated and vaccine-derived poliomyelitis. Bill & Melinda Gates Foundation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Chronological analysis of canine parvovirus type 2 isolates in Japan.

PubMed

Ohshima, Takahisa; Hisaka, Mitsuaki; Kawakami, Kazuo; Kishi, Masahiko; Tohya, Yukinobu; Mochizuki, Masami

2008-08-01

Fifty-five canine parvovirus type 2 (CPV) samples, 12 fecal specimens and 43 cell culture isolates, were examined for their genetic characteristics of VP2 gene. They were collected from the diseased dogs at various districts of Japan during 27 years from 1980 to 2006. A fragment of VP2 gene was analyzed by restriction fragment length polymorphism assay and DNA sequencing. The original antigenic type 2 of CPV (CPV-2) was no longer found in the samples since 1984, and two antigenic variants CPV-2a and CPV-2b replaced CPV-2 as predominant types for about 5 years from 1982. A new genetic variant of prototype CPV-2a with non-synonymous substitution at the VP2 amino acid residue 297 from Ser to Ala was first detected in 1987. New CPV-2b with the same amino acid substitution at position 297 as new CPV-2a was also detected from the samples collected in 1997. Since then new CPV-2b has been the predominant CPV over the field of Japan. Several additional amino acid substitutions were detected in the VP2 gene of some recent CPV strains. Neither CPV-2c(a), CPV-2c(b), nor "Glu-426" of the antigenic variants previously found outside the country was detected in any samples tested. Reactivity of new CPV-2a and 2b variants against antibodies produced by the current vaccine products was determined by a cross hemagglutination-inhibition test. The recent field CPV isolates reacted more efficiently to the antibodies produced in dogs vaccinated with the new CPV-2b vaccine strain than the conventional CPV-2 vaccine strain.

Phosphatidylserine as an anchor for plasminogen and its plasminogen receptor, Histone H2B, to the macrophage surface

PubMed Central

DAS, R.; PLOW, E. F.

2013-01-01

Summary Background Plasminogen (Plg) binding to cell surface Plg receptors (Plg-Rs) on the surface of macrophages facilitates Plg activation and migration of these cells. Histone H2B (H2B) acts as a Plg-R and its cell surface expression is upregulated when monocytes are differentiated to macrophages via a pathway dependent on L-type Ca2+ channels and intracellular Ca2+. Objectives We sought to investigate the mechanism by which H2B, a protein without a transmembrane domain, is retained on themacrophage surface. Methods THP-1 monocytoid cells were induced to differentiate with interferon gamma + Vitamin D3 or to undergo apoptosis by treatment with camptothecin. Flow cytometry and cell surface biotinylation followed by Western blotting were used to measure the interrelationship between Plg binding, cell surface expression of H2B and outermembrane exposure of phosphatidylserine (PS). Results H2B interacted directly with PS via an electrostatic interaction. Anti-PS or PS binding proteins, annexin V and protein S, diminished H2B interaction with PS on the surface of differentiated or apoptotic cells and these same reagents inhibited Plg binding to these cells. L-type Ca2+ channels played a significant role in PS exposure, H2B surface expression and Plg binding induced either by differentiation or apoptosis. Conclusions These data suggest that H2B tethers to the surface of cells by interacting with PS on differentiated or apoptotic monocytoid cells. L-type Ca2+ channels regulate PS exposure on the surface of these cells. The exposed PS interacts directly with H2B and hence provides sites for Plg to bind to. PMID:21040449

VizieR Online Data Catalog: VLT-FLAMES Tarantula Survey. 30 Dor luminous stars (Doran+, 2013)

NASA Astrophysics Data System (ADS)

Doran, E. I.; Crowther, P. A.; de Koter, A.; Evans, C. J.; McEvoy, C.; Walborn, N. R.; Bastian, N.; Bestenlehner, J. M.; Grafener, G.; Herrero, A.; Kohler, K.; Maiz Apellaniz, J.; Najarro, F.; Puls, J.; Sana, H.; Schneider, F. R. N.; Taylor, W. D.; van Loon, J. T.; Vink, J. S.

2013-08-01

A census was compiled of all the hot luminous stars within the central 10 arcminutes of 30 Doradus. Candidate hot luminous stars were selected from a series of photometric catalogues, using a set of criteria explained in the paper. All stars meeting this photometric criteria are listed in Tabled1.dat. In addition, Table D1 includes all known Wolf-Rayet and Of/WN stars in the region, which may not have been selected due to photometric effects. Spectral Types were then matched to as many of the candidate stars in Tabled1.dat as possible. Stellar parameters were determined for all stars with the following spectral types: W-R, Of/WN, O-type, B-supergiant, B-giant B1I or earlier, B-dwarf, B0.5V or earlier. These parameters are listed in Tabled2.dat. Parameters of all O-type and B-type stars were derived through various calibrations. Parameters of W-R and Of/WN stars were based on previous work or various template models explained in the paper. (2 data files).

Type A and B behavior patterns and self-reported health symptoms and stress: examining individual and organizational fit.

PubMed

Matteson, M T; Ivancevich, J M

1982-08-01

This article describes a preliminary investigation of the proposition that organizations, as well as people, can be classified along a Type A and B behavior pattern dimension and that the resulting match or lack thereof between individual and organizational behavior patterns is related to various health indices. A sample of 315 medical technologists were classified as either Type As or Bs and as working in either Type A or B environments. Results supported the hypotheses that (1) Type Bs in B organizations report the fewest negative health symptoms; (2) Type As in A organizations report the most; and (3) Type Bs in A organizations and Type As in B organizations report an intermediate level of symptoms. The results are treated within the framework of a person-environment fit model and the implications of the findings are discussed.

Energy Harvesting and Storage Systems for Future AF Vehicles

DTIC Science & Technology

2012-05-11

of Bi dopant . Thermal conductivity are little influenced by Bi (Fig. B 12c ). From the result of the figure-of-merit (Fig. B12d), 3 at% Bi doped...type doping element, and K is n-type dopant while Ag doped Mg2Si has a transition from n-type top-type at 350C. ZT of these TE alloys are much lower...metal (2 llflll Eledrolyte - Uthium phosphorus oxynitride (UPON) Uz.gPOnNo.45 (2 llfll) developed by ORNL c.thode - Uthium cobalt oxide UCo02(6

Chemical Basis for Qualitative and Quantitative Differences Between ABO Blood Groups and Subgroups: Implications for Organ Transplantation.

PubMed

Jeyakanthan, M; Tao, K; Zou, L; Meloncelli, P J; Lowary, T L; Suzuki, K; Boland, D; Larsen, I; Burch, M; Shaw, N; Beddows, K; Addonizio, L; Zuckerman, W; Afzali, B; Kim, D H; Mengel, M; Shapiro, A M J; West, L J

2015-10-01

Blood group ABH(O) carbohydrate antigens are carried by precursor structures denoted type I-IV chains, creating unique antigen epitopes that may differ in expression between circulating erythrocytes and vascular endothelial cells. Characterization of such differences is invaluable in many clinical settings including transplantation. Monoclonal antibodies were generated and epitope specificities were characterized against chemically synthesized type I-IV ABH and related glycans. Antigen expression was detected on endomyocardial biopsies (n = 50) and spleen (n = 11) by immunohistochemical staining and on erythrocytes by flow cytometry. On vascular endothelial cells of heart and spleen, only type II-based ABH antigens were expressed; type III/IV structures were not detected. Type II-based ABH were expressed on erythrocytes of all blood groups. Group A1 and A2 erythrocytes additionally expressed type III/IV precursors, whereas group B and O erythrocytes did not. Intensity of A/B antigen expression differed among group A1 , A2 , A1 B, A2 B and B erythrocytes. On group A2 erythrocytes, type III H structures were largely un-glycosylated with the terminal "A" sugar α-GalNAc. Together, these studies define qualitative and quantitative differences in ABH antigen expression between erythrocytes and vascular tissues. These expression profiles have important implications that must be considered in clinical settings of ABO-incompatible transplantation when interpreting anti-ABO antibodies measured by hemagglutination assays with reagent erythrocytes. © Copyright 2015 The American Society of Transplantation and the American Society of Transplant Surgeons.

[Carbon storage of forest vegetation and allocation for main forest types in the east of Da-xing'an Mountains based on additive biomass model].

PubMed

Peng, Wei; Dong, Li Hu; Li, Feng Ri

2016-12-01

Based on the biomass investigation data of main forest types in the east of Daxing'an Mountains, the additive biomass models of 3 main tree species were developed and the changes of carbon storage and allocation of forest community of tree layer, shrub layer, herb layer and litter layer from different forest types were discussed. The results showed that the carbon storage of tree layer, shrub layer, herb layer and litter layer for Rhododendron dauricum-Larix gmelinii forest was 71.00, 0.34, 0.05 and 11.97 t·hm -2 , respectively. Similarly, the carbon storage of the four layers of Ledum palustre-L. gmelinii forest was 47.82, 0.88, 0, 5.04 t·hm -2 , 56.56, 0.44, 0.04, 8.72 t·hm -2 for R. dauricum-mixed forest of L. gmelinii-Betula platyphylla, 46.21, 0.66, 0.07, 6.16 t·hm -2 for L. palustre-mixed forest of L. gmelinii-B. platyphylla, 40.90, 1.37, 0.04, 3.67 t·hm -2 for R. dauricum-B. platyphylla forest, 36.28, 1.12, 0.18, 4.35 t·hm -2 for L. palustre-B. platyphylla forest. The carbon storage of forest community for the understory vegetation of R. dauricum was higher than that of the forest with L. palustre. In the condition of similar circumstances for the understory, the order of carbon storage for forest community was L. gmelinii forest > the mixed forest of L. gmelinii-B. platyphylla > B. platyphylla forest. The carbon storage of different forest types was different with the order of R. dauricum-L. gmelinii forest (83.36 t·hm -2 )> R. dauricum-mixed forest of L. gmelinii-B. platyphylla (65.76 t·hm -2 ) > L. palustre-L. gmelinii forest (53.74 t·hm -2 )> L. palustre-mixed forest of L. gmelinii-B. platyphylla (53.10 t·hm -2 )> R. dauricum-B. platyphylla forest (45.98 t·hm -2 ) > L. palustre-B. platyphylla forest (41.93 t·hm -2 ). The order of carbon storage for the vertical distribution in forest communities with diffe-rent forest types was the tree layer (85.2%-89.0%) > litter layer (8.0%-14.4%) > shrub layer (0.4%-2.7%) > herb layer (0-0.4%).

21 CFR 1270.21 - Determination of donor suitability for human tissue intended for transplantation.

Code of Federal Regulations, 2012 CFR

2012-04-01

... virus, Type 1 (e.g., FDA licensed screening test for anti-HIV-1); (2) Human immunodeficiency virus, Type 2 (e.g., FDA licensed screening test for anti-HIV-2); (3) Hepatitis B (e.g., FDA licensed screening... been tested and found negative using FDA licensed screening tests for HIV-1, HIV-2, hepatitis B, and...

21 CFR 1270.21 - Determination of donor suitability for human tissue intended for transplantation.

Code of Federal Regulations, 2014 CFR

2014-04-01

... virus, Type 1 (e.g., FDA licensed screening test for anti-HIV-1); (2) Human immunodeficiency virus, Type 2 (e.g., FDA licensed screening test for anti-HIV-2); (3) Hepatitis B (e.g., FDA licensed screening... been tested and found negative using FDA licensed screening tests for HIV-1, HIV-2, hepatitis B, and...

21 CFR 1270.21 - Determination of donor suitability for human tissue intended for transplantation.

Code of Federal Regulations, 2011 CFR

2011-04-01

... virus, Type 1 (e.g., FDA licensed screening test for anti-HIV-1); (2) Human immunodeficiency virus, Type 2 (e.g., FDA licensed screening test for anti-HIV-2); (3) Hepatitis B (e.g., FDA licensed screening... been tested and found negative using FDA licensed screening tests for HIV-1, HIV-2, hepatitis B, and...

21 CFR 1270.21 - Determination of donor suitability for human tissue intended for transplantation.

Code of Federal Regulations, 2013 CFR

2013-04-01

... virus, Type 1 (e.g., FDA licensed screening test for anti-HIV-1); (2) Human immunodeficiency virus, Type 2 (e.g., FDA licensed screening test for anti-HIV-2); (3) Hepatitis B (e.g., FDA licensed screening... been tested and found negative using FDA licensed screening tests for HIV-1, HIV-2, hepatitis B, and...

Pressure induced structural phase transition from NaCl-type (B1) to CsCl-type (B2) structure in sodium chloride

NASA Astrophysics Data System (ADS)

Jain, Aayushi; Dixit, R. C.

2018-05-01

Pressure induced structural phase transition of NaCl-type (B1) to CsCl-type (B2) structure in Sodium Chloride NaCl are presented. An effective interionic interaction potential (EIOP) with long range Coulomb, van der Waals (vdW) interaction and the short-range repulsive interaction upto second-neighbor ions within the Hafemeister and Flygare approach with modified ionic charge is reported here. The reckon value of the phase transition pressure (Pt) and the magnitude of the discontinuity in volume at the transition pressure are compatible as compared with reported data. The variations of elastic constants and their combinations with pressure follow ordered behavior. The present approach has also succeeded in predicting the Born and relative stability criteria.

Polyhedral realizations of crystal bases for quantum algebras of classical affine types

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hoshino, A.

2013-05-15

We give the explicit forms of the crystal bases B({infinity}) for the quantum affine algebras of types A{sub 2n-1}{sup (2)}, A{sub 2n}{sup (2)}, B{sub n}{sup (1)}, C{sub n}{sup (1)}, D{sub n}{sup (1)}, and D{sub n+1}{sup (2)} by using the method of polyhedral realizations of crystal bases.

Evaluation of Limb-Girdle Muscular Dystrophy

ClinicalTrials.gov

2014-03-06

Becker Muscular Dystrophy; Limb-Girdle Muscular Dystrophy, Type 2A (Calpain-3 Deficiency); Limb-Girdle Muscular Dystrophy, Type 2B (Miyoshi Myopathy, Dysferlin Deficiency); Limb-Girdle Muscular Dystrophy, Type 2I (FKRP-deficiency)

Jet fuel from 18 cool-season oilseed feedstocks in a semi-arid environment

NASA Astrophysics Data System (ADS)

Allen, Brett; Jabro, Jay

2017-04-01

Renewable jet fuel feedstocks can potentially offset the demand for petroleum based transportation resources, diversify cropping systems, and provide numerous ecosystem services . However, identifying suitable feedstock supplies remains a primary constraint to adoption. A 4-yr, multi-site experiment initiated in fall 2012 investigated the yield potential of six winter- and twelve spring-types of cool-season oilseed feedstocks. Sidney, MT (250 mm annual growing season precipitation) was one of eight sites in the western USA with others in Colorado, Idaho, Iowa, Minnesota, North Dakota, Oregon, and Texas. Winter types of Camelina sativa (1), Brassica napus (4), and B. rapa (1) were planted in mid-September, while spring types of Camelina sativa (1), B. napus (4), B. rapa (1), B. juncea (2), B. carinata (2), and Sinapis alba (2) were planted in early to late April. Seeding rates varied by entry and were between 4 to 11 kg/ha. All plots were under no-till management. Plots were 3 by 9 m with each treatment (oilseed entry) replicated four times. Camelina 'Joelle' was the only fall-seeded entry that survived winters with little to no snow cover on plots and where minimum air temperature reached -32°C. Stands of 'Joelle' in the spring of all years were excellent. 'Joelle' plots were typically harvested in July, while spring types were harvested 2-6 weeks later. Severe hailstorms during the late growing seasons of 2013 and 2015 resulted in up to 95% seed loss, preventing normal seed yield harvest of spring types. The B. carinata and spring camelina were the least and most susceptible to hail damage during plant maturity, respectively. 'Joelle' winter camelina was harvested before the severe weather in both years, showing the benefit of an early maturing crop in regions prone to late season hail. Overall, camelina was the only winter type that showed potential as an oilseed feedstock due to its superior winter hardiness. For spring types, B. napus, Camelina sativa, and B. carinata showed the greatest potential. Seed yield, excluding the five winter types that succumbed every year to winter kill, ranged from about 200 to 2000 kg/ha, with B. napus hybrids (1900 kg/ha), winter and spring camelina (1700 kg/ha), and B. carinata (1300 kg/ha) showing the greatest feedstock potential. Other measurements taken, but not reported included crop phenology, canopy spectral reflectance, leaf area, leaf area index, canopy temperature, soil water use, crop biomass, yield components, seed oil%, seed fatty acid composition, and drought resistance. Overall, camelina was the only winter type in addition to spring types of B. napus, B. carinata, and camelina that showed good potential for jet fuel feedstocks in the semi-arid northern Great Plains, USA.

Effects of 17beta-estradiol on glutamate synaptic transmission and neuronal excitability in the rat medial vestibular nuclei.

PubMed

Grassi, S; Frondaroli, A; Scarduzio, M; Dutia, M B; Dieni, C; Pettorossi, V E

2010-02-17

We investigated the effects of the neurosteroid 17beta-estradiol (E(2)) on the evoked and spontaneous activity of rat medial vestibular nucleus (MVN) neurons in brainstem slices. E(2) enhances the synaptic response to vestibular nerve stimulation in type B neurons and depresses the spontaneous discharge in both type A and B neurons. The amplitude of the field potential, as well as the excitatory post-synaptic potential (EPSP) and current (EPSC), in type B neurons, are enhanced by E(2). Both effects are long-term phenomena since they outlast the drug washout. The enhancement of synaptic response is mainly due to facilitation of glutamate release mediated by pre-synaptic N-methyl-D-aspartate receptors (NMDARs), since the reduction of paired pulse ratio (PPR) and the increase of miniature EPSC frequency after E(2) are abolished under D-(-)-2-amino-5-phosphonopentanoic acid (AP-5). E(2) also facilitates post-synaptic NMDARs, but it does not affect directly alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs) and group I-metabotropic glutamate receptors (mGluRs-I). In contrast, the depression of the spontaneous discharge of type A and type B neurons appears to depend on E(2) modulation of intrinsic ion conductances, as the effect remains after blockade of glutamate, GABA and glycine receptors (GlyRs). The net effect of E(2) is to enhance the signal-to-noise ratio of the synaptic response in type B neurons, relative to resting activity of all MVN neurons. These findings provide evidence for a novel potential mechanism to modulate the responsiveness of vestibular neurons to afferent inputs, and so regulate vestibular function in vivo.

Chemical structures of constituents from the whole plant of Bacopa monniera.

PubMed

Ohta, Tomoe; Nakamura, Seikou; Nakashima, Souichi; Oda, Yoshimi; Matsumoto, Takahiro; Fukaya, Masashi; Yano, Mamiko; Yoshikawa, Masayuki; Matsuda, Hisashi

2016-07-01

Two new dammarane-type triterpene oligoglycosides, bacomosaponins A and B, and three new phenylethanoid glycosides, bacomosides A, B1, and B2, were isolated from the whole plant of Bacopa monniera Wettst. The chemical structures of the new constituents were characterized on the basis of chemical and physicochemical evidence. In the present study, bacomosaponins A and B with acyl groups were obtained from the whole plant of B. monniera. This is the first report of acylated dammarane-type triterpene oligoglycosides isolated from B. monniera. In addition, dammarane-type triterpene saponins significantly inhibited the aggregation of 42-mer amyloid β-protein.

Hydrolytic stability of pneumococcal group 6 (type 6A and 6B) capsular polysaccharides.

PubMed Central

Zon, G; Szu, S C; Egan, W; Robbins, J D; Robbins, J B

1982-01-01

The hydrolyses of the immunologically cross-reactive and constitutionally isomeric group 6 pneumococcal polysaccharides, types 6A and 6B, were investigated by 31P nuclear magnetic resonance spectroscopy, gel filtration through Sepharose 4B, reducing-sugar analysis, and rocket immunoelectrophoresis. Phosphorus nuclear magnetic resonance spectroscopy showed that cleavage of the repeating-unit phosphodiester linkages at pH 10, 60 degrees C was considerably faster (greater than 10(3) ) for the type 6A than the type 6B polysaccharide. Under these reaction conditions, 31P nuclear magnetic resonance kinetic measurements showed that the Na+ form of the type 6A polysaccharide underwent phosphodiester-linkage hydrolysis two times slower than the corresponding Ca+2 form; a stoichiometrically excess amount of Ca+2 caused a 30-fold enhancement of the latter hydrolysis rate. The spectroscopic characterization of phosphorus-containing end groups resulting from hydrolysis of the type 6A polymer provided additional mechanistic information. Heating the type 6A and 6B polysaccharides at 56 degrees C for various times led to gel filtration coefficients of distribution (Kd values) which indicated that the type 6A material underwent size reductions considerably faster than did the type 6B antigen; these increased Kd values qualitatively correlated with the loss of immunochemical reactivity measured by rocket immunoelectrophoresis. The application of a statistical theory to the depolymerization of the type 6A and 6B polysaccharides was consistent with random bond cleavage, as evidenced by the calculated versus measured gel filtration patterns. Although the molecular changes causing the size reductions were not fully elaborated, it was established that the acetal linkages of the type 6A and 6B polysaccharides were comparatively resistant to hydrolysis and that depolymerization by hydrolysis of the phosphodiester linkage was a major factor only in the type 6A structure. It was concluded that the hydrolytic stability of the type 6B antigen would favor its use in the polyvalent pneumococcal vaccine rather than the cross-reactive, but comparatively unstable, type 6A polysaccharide, if all other factors are equal. Images PMID:7107011

B2B Models for DoD Acquisition

DTIC Science & Technology

2008-01-15

unlimited. Prepared for: Naval Postgraduate School, Monterey, California 93943 B2B Models for DoD Acquisition 15 January 2008 by Magdi N...TYPE AND DATES COVERED 1 Oct 2006 through 30 Sept 2007 4. TITLE AND SUBTITLE B2B Models for DoD Acquisition 5. FUNDING 6. AUTHOR (S...public release; distribution is unlimited 12b. DISTRIBUTION CODE 13. ABSTRACT (Maximum 200 words.) A central vision of B2B e-commerce is that

EZH2 is required for germinal center formation and somatic EZH2 mutations promote lymphoid transformation

PubMed Central

Béguelin, Wendy; Popovic, Relja; Teater, Matt; Jiang, Yanwen; Bunting, Karen L.; Rosen, Monica; Shen, Hao; Yang, Shao Ning; Wang, Ling; Ezponda, Teresa; Martinez-Garcia, Eva; Zhang, Haikuo; Zhang, Yupeng; Verma, Sharad K.; McCabe, Michael T.; Ott, Heidi M.; Van Aller, Glenn S.; Kruger, Ryan G.; Liu, Yan; McHugh, Charles F.; Scott, David W.; Chung, Young Rock; Kelleher, Neil; Shaknovich, Rita; Creasy, Caretha L.; Gascoyne, Randy D.; Wong, Kwok-Kin; Cerchietti, Leandro C.; Levine, Ross L.; Abdel-Wahab, Omar; Licht, Jonathan D.; Elemento, Olivier; Melnick, Ari M.

2013-01-01

The EZH2 histone methyltransferase is highly expressed in germinal center (GC) B-cells and targeted by somatic mutations in B-cell lymphomas. Here we find that EZH2 deletion or pharmacologic inhibition suppresses GC formation and functions in mice. EZH2 represses proliferation checkpoint genes and helps establish bivalent chromatin domains at key regulatory loci to transiently suppress GC B-cell differentiation. Somatic mutations reinforce these physiological effects through enhanced silencing of EZH2 targets in B-cells, and in human B-cell lymphomas. Conditional expression of mutant EZH2 in mice induces GC hyperplasia and accelerated lymphomagenesis in cooperation with BCL2. GCB-type DLBCLs are mostly addicted to EZH2, regardless of mutation status, but not the more differentiated ABC-type DLBCLs, thus clarifying the therapeutic scope of EZH2 targeting. PMID:23680150

Pt-B System Revisited: Pt2B, a New Structure Type of Binary Borides. Ternary WAl12-Type Derivative Borides.

PubMed

Sologub, Oksana; Salamakha, Leonid; Rogl, Peter; Stöger, Berthold; Bauer, Ernst; Bernardi, Johannes; Giester, Gerald; Waas, Monika; Svagera, Robert

2015-11-16

On the basis of a detailed study applying X-ray single-crystal and powder diffraction, differential scanning calorimetry, and scanning electron microscopy analysis, it was possible to resolve existing uncertainties in the Pt-rich section (≥65 atom % Pt) of the binary Pt-B phase diagram above 600 °C. The formation of a unique structure has been observed for Pt2B [X-ray single-crystal data: space group C2/m, a = 1.62717(11) nm, b = 0.32788(2) nm, c = 0.44200(3) nm, β = 104.401(4)°, RF2 = 0.030]. Within the homogeneity range of "Pt3B", X-ray powder diffraction phase analysis prompted two structural modifications as a function of temperature. The crystal structure of "hT-Pt3B" complies with the hitherto reported structure of anti-MoS2 [space group P63/mmc, a = 0.279377(2) nm, c = 1.04895(1) nm, RF = 0.075, RI = 0.090]. The structure of the new "[Formula: see text]T-Pt3B" is still unknown. The formation of previously reported Pt∼4B has not been confirmed from binary samples. Exploration of the Pt-rich section of the Pt-Cu-B system at 600 °C revealed a new ternary compound, Pt12CuB6-y [X-ray single-crystal data: space group Im3̅, a = 0.75790(2) nm, y = 3, RF2 = 0.0129], which exhibits the filled WAl12-type structure accommodating boron in the interstitial trigonal-prismatic site 12e. The isotypic platinum-aluminum-boride was synthesized and studied. The solubility of copper in binary platinum borides has been found to attain ∼7 atom % Cu for Pt2B but to be insignificant for "[Formula: see text]T-Pt3B". The architecture of the new Pt2B structure combines puckered layers of boron-filled and empty [Pt6] octahedra (anti-CaCl2-type fragment) alternating along the x axis with a double layer of boron-semifilled [Pt6] trigonal prisms interbedded with a layer of empty tetrahedra and tetragonal pyramids (B-deficient α-T[Formula: see text]I fragment). Assuming boron vacancies ordering (space group R3), the Pt12CuB6-y structure exhibits serpentine-like columns of edge-connected boron-filled [Pt6] trigonal prisms running infinitely along the z axis and embedding the icosahedrally coordinated Cu atom. Pt2B, (Pt1-yCuy)2B (y = 0.045), and Pt12CuB6-y (y = 3) behave metallically, as revealed by temperature-dependent electrical resistivity measurements.

Metabolic pathways for lipid synthesis under nitrogen stress in Chlamydomonas and Nannochloropsis.

PubMed

Banerjee, Avik; Maiti, Subodh K; Guria, Chandan; Banerjee, Chiranjib

2017-01-01

Microalgae are currently being considered as a clean, sustainable and renewable energy source. Enzymes that catalyse the metabolic pathways for biofuel production are specific and require strict regulation and co-ordination. Thorough knowledge of these key enzymes along with their regulatory molecules is essential to enable rational metabolic engineering, to drive the metabolic flux towards the desired metabolites of importance. This paper reviews two key enzymes that play their role in production of bio-oil: DGAT (acyl-CoA:diacylglycerol acyltransferase) and PDAT (phospholipid:diacylglycerol acyltransferase). It also deals with the transcription factors that control the enzymes while cell undergoes a metabolic shift under stress. The paper also discusses the association of other enzymes and pathways that provide substrates and precursors for oil accumulation. Finally a futuristic solution has been proposed about a synthetic algal cell platform that would be committed towards biofuel synthesis.

At what conditions does zircon grow/dissolve during high-T metamorphism? Relating zircon textures to PT-conditions

NASA Astrophysics Data System (ADS)

Kunz, Barbara E.; Regis, Daniele; Manzotti, Paola; Engi, Martin

2015-04-01

A key question in ziconology is when and how zircon grows during metamorphism. To shed light on zircon forming processes and the corresponding PT-conditions during high-T metamorphism a case study was undertaken. The Ivrea Zone (N-Italy) exposes a lower continental crustal section in which a continuous metamorphic field gradient from amphibolite to granulite facies is documented. This field gradient is thought to reflect protracted heating during late Paleozoic times, with a probable high-T peak in the Permian. We present first results from a primarily textural study supported by U-Pb ages, Th/U ratios and Ti-in-Zrn thermometry. Four types of zircon were identified based on their overgrowth proportions and the preservation of detrital cores. Zircon grains were thus classified as Type1 - detrital grains with no overgrowth or very narrow rims (300 Ma) and appears to reflect an early dehydration phase. Rim2b has Permian ages (median 275 Ma), is by far the most common overgrowth type, found in a wide PT-range. Its development appears related to biotite breakdown. Rim3 is texturally indicative of magmatic zircon, occurs only in diatexites. Rim4 is the latest overgrowth and is locally found at all metamorphic grades. Textural features suggest late fluid-related recrystallization of existing zircon. At lowest grade (675±35°C, 6±2 kbar) zircons show type1 only, overgrowths are too thin to clearly identify the rim type. Further upgrade (~700°C, 7 kbar) type1 and type2 dominate. Type2 zircons show rim1, rim2a and occasionally rim4. At the Mu-out isograd (750±50°C, 8.2±1.4 kbar) most zircons are of type2, now with rim2b instead of 2a, in addition to rim1 and rim4. Near and in granulite facies (to 800°C, 8±2 kbar) mostly zircon type2 and type4 are present. While rim1 gets more narrow with increasing metamorphic grade, rim2b grows significantly thicker. Occasionally rim2a and rim4 occur. Close to the Bt-out isograd (~860°C, 9.2±1.7 kbar), mostly type3 and type4 are found. Rim1 is absent, and rim2b is commonly overgrown by rim3. Above the Bt-out isograd (>870°C, 9.5 kbar) zircon types3 and type4 dominate. Rim1 is missing, while Rim2b is the most common type, often with a thin rim4. Detailed textural features alone often are not sufficient to relate zircon growth zones to PT-conditions. In combination with U-Pb ages, Th/U ratios and Ti-in-Zrn thermometry, however it is possible to link spot ages to PT-conditions.

Possible involvement of nuclear factor erythroid 2-related factor 2 in the gene expression of Cyp2b10 and Cyp2a5.

PubMed

Ashino, Takashi; Ohkubo-Morita, Haruyo; Yamamoto, Masayuki; Yoshida, Takemi; Numazawa, Satoshi

2014-01-01

Cytochrome P450 gene expression is altered by various chemical compounds. In this study, we used nuclear factor erythroid 2-related factor 2 (Nrf2)-deficient (Nrf2(-⧸-)) mice to investigate the involvement of Nrf2 in Cyp2b10 and Cyp2a5 gene expression. Phorone, an Nrf2 activator, strongly increased Cyp2b10 and Cyp2a5 mRNA as well as Nrf2 target genes, including NAD(P)H-quinone oxidoreductase-1 and heme oxygenase-1, in wild-type mouse livers 8 h after treatment. The phorone-induced mRNA levels in Nrf2(-⧸-) mouse livers were lower than that in wild-type mouse livers. Nrf2(-⧸-) mice showed attenuated Cyp2b10 and Cyp2a5 induction by phenobarbital, a classical Cyp2b inducer. These findings suggest that the Nrf2 pathway is involved in Cyp2b10 and Cyp2a5 gene expression.

Possible involvement of nuclear factor erythroid 2-related factor 2 in the gene expression of Cyp2b10 and Cyp2a5☆

PubMed Central

Ashino, Takashi; Ohkubo-Morita, Haruyo; Yamamoto, Masayuki; Yoshida, Takemi; Numazawa, Satoshi

2014-01-01

Cytochrome P450 gene expression is altered by various chemical compounds. In this study, we used nuclear factor erythroid 2-related factor 2 (Nrf2)–deficient (Nrf2−⧸−) mice to investigate the involvement of Nrf2 in Cyp2b10 and Cyp2a5 gene expression. Phorone, an Nrf2 activator, strongly increased Cyp2b10 and Cyp2a5 mRNA as well as Nrf2 target genes, including NAD(P)H-quinone oxidoreductase-1 and heme oxygenase-1, in wild-type mouse livers 8 h after treatment. The phorone-induced mRNA levels in Nrf2−⧸− mouse livers were lower than that in wild-type mouse livers. Nrf2−⧸− mice showed attenuated Cyp2b10 and Cyp2a5 induction by phenobarbital, a classical Cyp2b inducer. These findings suggest that the Nrf2 pathway is involved in Cyp2b10 and Cyp2a5 gene expression. PMID:24494203

Distribution and photobiology of Symbiodinium types in different light environments for three colour morphs of the coral Madracis pharensis: is there more to it than total irradiance?

NASA Astrophysics Data System (ADS)

Frade, P. R.; Englebert, N.; Faria, J.; Visser, P. M.; Bak, R. P. M.

2008-12-01

The role of symbiont variation in the photobiology of reef corals was addressed by investigating the links among symbiont genetic diversity, function and ecological distribution in a single host species, Madracis pharensis. Symbiont distribution was studied for two depths (10 and 25 m), two different light habitats (exposed and shaded) and three host colour morphs (brown, purple and green). Two Symbiodinium genotypes were present, as defined by nuclear internal transcribed spacer 2 ribosomal DNA (ITS2-rDNA) variation. Symbiont distribution was depth- and colour morph-dependent. Type B15 occurred predominantly on the deeper reef and in green and purple colonies, while type B7 was present in shallow environments and brown colonies. Different light microhabitats at fixed depths had no effect on symbiont presence. This ecological distribution suggests that symbiont presence is potentially driven by light spectral niches. A reciprocal depth transplantation experiment indicated steady symbiont populations under environment change. Functional parameters such as pigment composition, chlorophyll a fluorescence and cell densities were measured for 25 m and included in multivariate analyses. Most functional variation was explained by two photobiological assemblages that relate to either symbiont identity or light microhabitat, suggesting adaptation and acclimation, respectively. Type B15 occurs with lower cell densities and larger sizes, higher cellular pigment concentrations and higher peridinin to chlorophyll a ratio than type B7. Type B7 relates to a larger xanthophyll-pool size. These unambiguous differences between symbionts can explain their distributional patterns, with type B15 being potentially more adapted to darker or deeper environments than B7. Symbiont cell size may play a central role in the adaptation of coral holobionts to the deeper reef. The existence of functional differences between B-types shows that the clade classification does not necessarily correspond to functional identity. This study supports the use of ITS2 as an ecological and functionally meaningful marker in Symbiodinium.

Human T cell leukaemia virus type 2 tax protein mediates CC-chemokine expression in peripheral blood mononuclear cells via the nuclear factor kappa B canonical pathway.

PubMed

Barrios, C S; Castillo, L; Zhi, H; Giam, C-Z; Beilke, M A

2014-01-01

Retroviral co-infections with human immunodeficiency virus type-1 (HIV-1) and human T cell leukaemia virus type 1 (HTLV-1) or type 2 (HTLV-2) are prevalent in many areas worldwide. It has been observed that HIV-1/HTLV-2 co-infections are associated with slower rates of CD4(+) T cell decline and delayed progression to AIDS. This immunological benefit has been linked to the ability of Tax2, the transcriptional activating protein of HTLV-2, to induce the expression of macrophage inflammatory protein (MIP)-1α/CCL3, MIP-1β/CCL4 and regulated upon activation normal T cell expressed and secreted (RANTES)/CCL5 and to down-regulate the expression of the CCR5 co-receptor in peripheral blood mononuclear cells (PBMCs). This study aimed to assess the role of Tax2-mediated activation of the nuclear factor kappa B (NF-κB) signalling pathway on the production of the anti-viral CC-chemokines MIP-1α, MIP-1β and RANTES. Recombinant Tax1 and Tax2 proteins, or proteins expressed via adenoviral vectors used to infect cells, were tested for their ability to activate the NF-κB pathway in cultured PBMCs in the presence or absence of NF-κB pathway inhibitors. Results showed a significant release of MIP-1α, MIP-1β and RANTES by PBMCs after the activation of p65/RelA and p50. The secretion of these CC-chemokines was significantly reduced (P < 0·05) by canonical NF-κB signalling inhibitors. In conclusion, Tax2 protein may promote innate anti-viral immune responses through the activation of the canonical NF-κB pathway. © 2013 British Society for Immunology.

Sequencing and diversity analyses reveal extensive similarities between some epsilon-toxin-encoding plasmids and the pCPF5603 Clostridium perfringens enterotoxin plasmid.

PubMed

Miyamoto, Kazuaki; Li, Jihong; Sayeed, Sameera; Akimoto, Shigeru; McClane, Bruce A

2008-11-01

Clostridium perfringens type B and D isolates produce epsilon-toxin, the third most potent clostridial toxin. The epsilon-toxin gene (etx) is plasmid borne in type D isolates, but etx genetics have been poorly studied in type B isolates. This study reports the first sequencing of any etx plasmid, i.e., pCP8533etx, from type B strain NCTC8533. This etx plasmid is 64.7 kb, carries tcp conjugative transfer genes, and encodes additional potential virulence factors including beta2-toxin, sortase, and collagen adhesin but not beta-toxin. Interestingly, nearly 80% of pCP8533etx open reading frames (ORFs) are also present on pCPF5603, an enterotoxin-encoding plasmid from type A isolate F5603. Pulsed-field gel electrophoresis and overlapping PCR indicated that a pCP8533etx-like etx plasmid is also present in most, if not all, other type B isolates and some beta2-toxin-positive, cpe-negative type D isolates, while other type D isolates carry different etx plasmids. Sequences upstream of the etx gene vary between type B isolates and some type D isolates that do not carry a pCP8533etx-like etx plasmid. However, nearly all type B and D isolates have an etx locus with an upstream IS1151, and those etx loci typically reside near a dcm ORF. These results suggest that pCPF5603 and pCP8533etx evolved from insertion of mobile genetic elements carrying enterotoxin or etx genes, respectively, onto a common progenitor plasmid.

β-Lactamase Genes of the Penicillin-Susceptible Bacillus anthracis Sterne Strain

PubMed Central

Chen, Yahua; Succi, Janice; Tenover, Fred C.; Koehler, Theresa M.

2003-01-01

Susceptibility to penicillin and other β-lactam-containing compounds is a common trait of Bacillus anthracis. β-lactam agents, particularly penicillin, have been used worldwide to treat anthrax in humans. Nonetheless, surveys of clinical and soil-derived strains reveal penicillin G resistance in 2 to 16% of isolates tested. Bacterial resistance to β-lactam agents is often mediated by production of one or more types of β-lactamases that hydrolyze the β-lactam ring, inactivating the antimicrobial agent. Here, we report the presence of two β-lactamase (bla) genes in the penicillin-susceptible Sterne strain of B. anthracis. We identified bla1 by functional cloning with Escherichia coli. bla1 is a 927-nucleotide (nt) gene predicted to encode a protein with 93.8% identity to the type I β-lactamase gene of Bacillus cereus. A second gene, bla2, was identified by searching the unfinished B. anthracis chromosome sequence database of The Institute for Genome Research for open reading frames (ORFs) predicted to encode β-lactamases. We found a partial ORF predicted to encode a protein with significant similarity to the carboxy-terminal end of the type II β-lactamase of B. cereus. DNA adjacent to the 5′ end of the partial ORF was cloned using inverse PCR. bla2 is a 768-nt gene predicted to encode a protein with 92% identity to the B. cereus type II enzyme. The bla1 and bla2 genes confer ampicillin resistance to E. coli and Bacillus subtilis when cloned individually in these species. The MICs of various antimicrobial agents for the E. coli clones indicate that the two β-lactamase genes confer different susceptibility profiles to E. coli; bla1 is a penicillinase, while bla2 appears to be a cephalosporinase. The β-galactosidase activities of B. cereus group species harboring bla promoter-lacZ transcriptional fusions indicate that bla1 is poorly transcribed in B. anthracis, B. cereus, and B. thuringiensis. The bla2 gene is strongly expressed in B. cereus and B. thuringiensis and weakly expressed in B. anthracis. Taken together, these data indicate that the bla1 and bla2 genes of the B. anthracis Sterne strain encode functional β-lactamases of different types, but gene expression is usually not sufficient to confer resistance to β-lactam agents. PMID:12533457

Architecture and Transport Properties of Multifilamentary MgB2 Strands for MRI and Low AC Loss Applications

PubMed Central

Wan, F.; Sumption, M. D.; Rindfleisch, M. A.; Tomsic, M. J.; Collings, E. W.

2016-01-01

Standard in-situ type MgB2 strands manufactured by Hyper Tech Inc have 19 – 36 subelements, a monel outer sheath, and a Cu interfilamentary matrix. Typical transport Jcs of the strands are 2×105 A/cm2 with n-values of 20 – 30 at 4.2 K and 5 T. This work introduces two new MgB2 conductor designs. First, a new class of MgB2 strand is designed for magnetic resonance imaging applications. This type has a higher Cu content designed to enhance protection of a magnet wound with it, and a larger diameter to increase the critical current. Second, a new class of low AC loss MgB2 strand with high filament count and a high resistance matrix is discussed. Transport properties at 4.2 K and fields up to 10 T are reported. Optical techniques are used to study the macro- and micro-structures of these MgB2 strands. PMID:28827975

Serologic ambiguity and allelic frequency of the HLA-B40 family in the Korean population.

PubMed

Lee, K W; Kim, Y S

1997-04-01

The most frequently identified HLA-B type in Koreans is HLA-B40 (13.4%). Due to the lack of mono-specific alloantisera and cross reactivity of sera used as typing reagents, discrimination between the serologic splits of B40, B60 and B61, has been a problem in tissue typing laboratories. In this study, an efficient PCR-SSP typing system was established to distinguish B60 and B61 and to assess the difficulty in serologic assignment for these types. The SSP system was also used to elucidate the frequency of B40 alleles (B*4001-B*4008) encoding B40 molecules in the Korean population. Eighty eight unrelated individuals identified serologically as B40 positive were selected from 358 consecutive volunteers from the unrelated bone marrow registry. Seven sets of PCR that amplify exons 2 and 3 of the HLA-B gene using 10 sequence specific primers (SSP) were used for discrimination between B60 and B61, and for B40 allelic typing. A clear discrimination of B60 and B61 was possible in all samples including 48 serologically ambiguous samples (B60-14/48; B61-34/48) and 5 potentially B40 homozygous samples (B60/ B61 heterozygotes-4/5; B60 homozygote-1/5). Therefore, the use of a focused SSP approach enhances serologic definition of HLA types in routine clinical testing. In allelic typing, all B60 samples (26) appeared to be B*4001, but B61 samples revealed more heterogeneity (B*4002-36/58, B*4003-4/ 58, B*4006-18/58). In addition, B*4003 seemed to be closely associated with the A24-Cw3-DRB1*02 haplotype (3/4). The characterization of allele frequency as well as haplotypic association will be helpful in determination of the optimal size of the volunteer marrow donor pool in the Korean population.

49 CFR 387.323 - Electronic filing of surety bonds, trust fund agreements, certificates of insurance and...

Code of Federal Regulations, 2013 CFR

2013-10-01

... Start field End field Record type 1 Numeric 1=Filing2=Cancellation B 1 1 Insurer number 8 Text FMCSA... Filing type 1 Numeric 1 = BI&PD2 = Cargo 3 = Bond 4 = Trust Fund B 10 10 FMCSA docket number 8 Text FMCSA... 264 265 Insured zip code 9 Numeric (Do not include dash if using 9 digit code) B 266 274 Insured...

49 CFR 387.323 - Electronic filing of surety bonds, trust fund agreements, certificates of insurance and...

Code of Federal Regulations, 2014 CFR

2014-10-01

... Start field End field Record type 1 Numeric 1=Filing2=Cancellation B 1 1 Insurer number 8 Text FMCSA... Filing type 1 Numeric 1 = BI&PD2 = Cargo 3 = Bond 4 = Trust Fund B 10 10 FMCSA docket number 8 Text FMCSA... 264 265 Insured zip code 9 Numeric (Do not include dash if using 9 digit code) B 266 274 Insured...

B2B Models for DoD Acquisition

DTIC Science & Technology

2007-07-30

Internet, extranets, intranets, or private networks • In 2003 it represented about 11% of total B2B trade estimated at $13.5 trillion • Predicted to... B2B Models for DoD Acquisition 30 July 2007 by Magdi N. Kamel, Associate Professor Graduate School of Operational & Information Sciences...number. 1. REPORT DATE 30 JUL 2007 2. REPORT TYPE 3. DATES COVERED 00-00-2007 to 00-00-2007 4. TITLE AND SUBTITLE B2B Models for DoD

Modelling the B2C Marketplace: Evaluation of a Reputation Metric for e-Commerce

NASA Astrophysics Data System (ADS)

Gutowska, Anna; Sloane, Andrew

This paper evaluates recently developed novel and comprehensive reputation metric designed for the distributed multi-agent reputation system for the Business-to-Consumer (B2C) E-commerce applications. To do that an agent-based simulation framework was implemented which models different types of behaviours in the marketplace. The trustworthiness of different types of providers is investigated to establish whether the simulation models behaviour of B2C e-Commerce systems as they are expected to behave in real life.

Elevated Properdin and Enhanced Complement Activation in First-Degree Relatives of South Asian Subjects With Type 2 Diabetes

PubMed Central

Somani, Riyaz; Richardson, Victoria R.; Standeven, Kristina F.; Grant, Peter J.; Carter, Angela M.

2012-01-01

OBJECTIVE Emerging data implicate activation of the complement cascade in the pathogenesis of type 2 diabetes. The objective of the current study was to evaluate the relationships between components of the complement system, metabolic risk factors, and family history of type 2 diabetes in healthy South Asians. RESEARCH DESIGN AND METHODS We recruited 119 healthy, first-degree relatives of South Asian subjects with type 2 diabetes (SARs) and 119 age- and sex-matched, healthy South Asian control subjects (SACs). Fasting blood samples were taken for measurement of complement factors and standard metabolic risk factors. RESULTS SARs were characterized by significantly higher properdin (mean concentration 12.6 [95% CI 12.2–13.1] mg/L vs. SACs 10.1 [9.7–10.5] mg/L, P < 0.0001), factor B (187.4 [180.1–195.0] mg/L vs. SACs 165.0 [158.0–172.2] mg/L, P < 0.0001), and SC5b-9 (92.0 [86.1–98.3] ng/mL vs. SACs 75.3 [71.9–78.9] ng/mL, P < 0.0001) and increased homeostasis model assessment of insulin resistance (2.86 [2.61–3.13] vs. SACs 2.31 [2.05–2.61], P = 0.007). C-reactive protein did not differ between SARs and SACs (P = 0.17). In subgroup analysis of 25 SARs and 25 SACs with normal oral glucose tolerance tests, properdin, factor B, and SC5b-9 remained significantly elevated in SARs. CONCLUSIONS Increased properdin and complement activation are associated with a family history of type 2 diabetes in South Asians independent of insulin resistance, and predate the development of impaired fasting glucose and impaired glucose tolerance. Properdin and SC5b-9 may be novel biomarkers for future risk of type 2 diabetes in this high-risk population and warrant further investigation. PMID:22338105

MicroRNA miR-27b rescues bone marrow-derived angiogenic cell function and accelerates wound healing in type 2 diabetes mellitus.

PubMed

Wang, Jie-Mei; Tao, Jun; Chen, Dan-Dan; Cai, Jing-Jing; Irani, Kaikobad; Wang, Qinde; Yuan, Hong; Chen, Alex F

2014-01-01

Vascular precursor cells with angiogenic potentials are important for tissue repair, which is impaired in diabetes mellitus. MicroRNAs are recently discovered key regulators of gene expression, but their role in vascular precursor cell-mediated angiogenesis in diabetes mellitus is unknown. We tested the hypothesis that the microRNA miR-27b rescues impaired bone marrow-derived angiogenic cell (BMAC) function in vitro and in vivo in type 2 diabetic mice. BMACs from adult male type 2 diabetic db/db and from normal littermate db/+ mice were used. miR-27b expression was decreased in db/db BMACs. miR-27b mimic improved db/db BMAC function, including proliferation, adhesion, tube formation, and delayed apoptosis, but it did not affect migration. Elevated thrombospondin-1 (TSP-1) protein in db/db BMACs was suppressed on miR-27b mimic transfection. Inhibition of miR-27b in db/+ BMACs reduced angiogenesis, which was reversed by TSP-1 small interfering RNA (siRNA). miR-27b suppressed the pro-oxidant protein p66(shc) and mitochondrial oxidative stress, contributing to its protection of BMAC function. miR-27b also suppressed semaphorin 6A to improve BMAC function in diabetes mellitus. Luciferase binding assay suggested that miR-27b directly targeted TSP-1, TSP-2, p66(shc), and semaphorin 6A. miR-27b improved topical cell therapy of diabetic BMACs on diabetic skin wound closure, with a concomitant augmentation of wound perfusion and capillary formation. Normal BMAC therapy with miR-27b inhibition demonstrated reduced efficacy in wound closure, perfusion, and capillary formation. Local miR-27b delivery partly improved wound healing in diabetic mice. miR-27b rescues impaired BMAC angiogenesis via TSP-1 suppression, semaphorin 6A expression, and p66shc-dependent mitochondrial oxidative stress and improves BMAC therapy in wound healing in type 2 diabetic mice.

Autoinducer 2 controls biofilm formation in Escherichia coli through a novel motility quorum-sensing regulator (MqsR, B3022).

PubMed

González Barrios, Andrés F; Zuo, Rongjun; Hashimoto, Yoshifumi; Yang, Li; Bentley, William E; Wood, Thomas K

2006-01-01

The cross-species bacterial communication signal autoinducer 2 (AI-2), produced by the purified enzymes Pfs (nucleosidase) and LuxS (terminal synthase) from S-adenosylhomocysteine, directly increased Escherichia coli biofilm mass 30-fold. Continuous-flow cells coupled with confocal microscopy corroborated these results by showing the addition of AI-2 significantly increased both biofilm mass and thickness and reduced the interstitial space between microcolonies. As expected, the addition of AI-2 to cells which lack the ability to transport AI-2 (lsr null mutant) failed to stimulate biofilm formation. Since the addition of AI-2 increased cell motility through enhanced transcription of five motility genes, we propose that AI-2 stimulates biofilm formation and alters its architecture by stimulating flagellar motion and motility. It was also found that the uncharacterized protein B3022 regulates this AI-2-mediated motility and biofilm phenotype through the two-component motility regulatory system QseBC. Deletion of b3022 abolished motility, which was restored by expressing b3022 in trans. Deletion of b3022 also decreased biofilm formation significantly, relative to the wild-type strain in three media (46 to 74%) in 96-well plates, as well as decreased biomass (8-fold) and substratum coverage (19-fold) in continuous-flow cells with minimal medium (growth rate not altered and biofilm restored by expressing b3022 in trans). Deleting b3022 changed the wild-type biofilm architecture from a thick (54-mum) complex structure to one that contained only a few microcolonies. B3022 positively regulates expression of qseBC, flhD, fliA, and motA, since deleting b3022 decreased their transcription by 61-, 25-, 2.4-, and 18-fold, respectively. Transcriptome analysis also revealed that B3022 induces crl (26-fold) and flhCD (8- to 27-fold). Adding AI-2 (6.4 muM) increased biofilm formation of wild-type K-12 MG1655 but not that of the isogenic b3022, qseBC, fliA, and motA mutants. Adding AI-2 also increased motA transcription for the wild-type strain but did not stimulate motA transcription for the b3022 and qseB mutants. Together, these results indicate AI-2 induces biofilm formation in E. coli through B3022, which then regulates QseBC and motility; hence, b3022 has been renamed the motility quorum-sensing regulator gene (the mqsR gene).

Nb2OsB2, with a new twofold superstructure of the U3Si2 type: Synthesis, crystal chemistry and chemical bonding

NASA Astrophysics Data System (ADS)

Mbarki, Mohammed; Touzani, Rachid St.; Fokwa, Boniface P. T.

2013-07-01

The new ternary metal-rich boride, Nb2OsB2, was synthesized by arc-melting the elements in a water-cooled copper crucible under an argon atmosphere. The compound was characterized from single-crystal X-ray data and EDX measurements. It crystallizes as a new superstructure (space group P4/mnc, no. 128) of the tetragonal U3Si2-structure type with lattice parameters a=5.922(1) Å and c=6.879(2) Å. All of the B atoms are involved in B2 dumbbells with B-B distances of 1.89(4) Å. Structure relaxation using VASP (Vienna ab intio Simulation Package) has confirmed the space group and the lattice parameters. According to electronic structure calculations (TB-LMTO-ASA), the homoatomic B-B interactions are optimized and very strong, but relatively strong heteroatomic Os-B, Nb-B and Nb-Os bonds are also found: These interactions, which together build a three-dimensional network, are mainly responsible for the structural stability of this new phase. The density of state at the Fermi level predicts metallic behavior, as expected, from this metal-rich boride.

Diversity in genomic organisation, developmental regulation and distribution of the murine PR72/B" subunits of protein phosphatase 2A

PubMed Central

Zwaenepoel, Karen; Louis, Justin V; Goris, Jozef; Janssens, Veerle

2008-01-01

Background Protein phosphatase 2A (PP2A) is a serine/threonine-specific phosphatase displaying vital functions in growth and development through its role in various signalling pathways. PP2A holoenzymes comprise a core dimer composed of a catalytic C and a structural A subunit, which can associate with a variable B-type subunit. The importance of the B-type subunits for PP2A regulation cannot be overestimated as they determine holoenzyme localisation, activity and substrate specificity. Three B-type subunit families have been identified: PR55/B, PR61/B' and PR72/B", of which the latter is currently the least characterised. Results We deduced the sequences and genomic organisation of the different murine PR72/B" isoforms: three genes encode nine isoforms, five of which are abundantly expressed and give rise to genuine PP2A subunits. Thereby, one novel subunit was identified. Using Northern blotting, we examined the tissue-specific and developmental expression of these subunits. All subunits are highly expressed in heart, suggesting an important cardiac function. Immunohistochemical analysis revealed a striated expression pattern of PR72 and PR130 in heart and skeletal muscle, but not in bladder smooth muscle. The subcellular localisation and cell cycle regulatory ability of several PR72/B" isoforms were determined, demonstrating differences as well as similarities. Conclusion In contrast to PR55/B and PR61/B', the PR72/B" family seems evolutionary more divergent, as only two of the murine genes have a human orthologue. We have integrated these results in a more consistent nomenclature of both human and murine PR72/B" genes and their transcripts/proteins. Our results provide a platform for the future generation of PR72/B" knockout mice. PMID:18715506

HLA-B27 and Human β2-Microglobulin Affect the Gut Microbiota of Transgenic Rats

PubMed Central

Lin, Phoebe; Bach, Mary; Asquith, Mark; Lee, Aaron Y.; Akileswaran, Lakshmi; Stauffer, Patrick; Davin, Sean; Pan, Yuzhen; Cambronne, Eric D.; Dorris, Martha; Debelius, Justine W.; Lauber, Christian L.; Ackermann, Gail; Baeza, Yoshiki V.; Gill, Tejpal; Knight, Rob; Colbert, Robert A.; Taurog, Joel D.; Van Gelder, Russell N.; Rosenbaum, James T.

2014-01-01

The HLA-B27 gene is a major risk factor for clinical diseases including ankylosing spondylitis, acute anterior uveitis, reactive arthritis, and psoriatic arthritis, but its mechanism of risk enhancement is not completely understood. The gut microbiome has recently been shown to influence several HLA-linked diseases. However, the role of HLA-B27 in shaping the gut microbiome has not been previously investigated. In this study, we characterize the differences in the gut microbiota mediated by the presence of the HLA-B27 gene. We identified differences in the cecal microbiota of Lewis rats transgenic for HLA-B27 and human β2-microglobulin (hβ2m), compared with wild-type Lewis rats, using biome representational in situ karyotyping (BRISK) and 16S rRNA gene sequencing. 16S sequencing revealed significant differences between transgenic animals and wild type animals by principal coordinates analysis. Further analysis of the data set revealed an increase in Prevotella spp. and a decrease in Rikenellaceae relative abundance in the transgenic animals compared to the wild type animals. By BRISK analysis, species-specific differences included an increase in Bacteroides vulgatus abundance in HLA-B27/hβ2m and hβ2m compared to wild type rats. The finding that HLA-B27 is associated with altered cecal microbiota has not been shown before and can potentially provide a better understanding of the clinical diseases associated with this gene. PMID:25140823

HLA-B27 and human β2-microglobulin affect the gut microbiota of transgenic rats.

PubMed

Lin, Phoebe; Bach, Mary; Asquith, Mark; Lee, Aaron Y; Akileswaran, Lakshmi; Stauffer, Patrick; Davin, Sean; Pan, Yuzhen; Cambronne, Eric D; Dorris, Martha; Debelius, Justine W; Lauber, Christian L; Ackermann, Gail; Baeza, Yoshiki V; Gill, Tejpal; Knight, Rob; Colbert, Robert A; Taurog, Joel D; Van Gelder, Russell N; Rosenbaum, James T

2014-01-01

The HLA-B27 gene is a major risk factor for clinical diseases including ankylosing spondylitis, acute anterior uveitis, reactive arthritis, and psoriatic arthritis, but its mechanism of risk enhancement is not completely understood. The gut microbiome has recently been shown to influence several HLA-linked diseases. However, the role of HLA-B27 in shaping the gut microbiome has not been previously investigated. In this study, we characterize the differences in the gut microbiota mediated by the presence of the HLA-B27 gene. We identified differences in the cecal microbiota of Lewis rats transgenic for HLA-B27 and human β2-microglobulin (hβ2m), compared with wild-type Lewis rats, using biome representational in situ karyotyping (BRISK) and 16S rRNA gene sequencing. 16S sequencing revealed significant differences between transgenic animals and wild type animals by principal coordinates analysis. Further analysis of the data set revealed an increase in Prevotella spp. and a decrease in Rikenellaceae relative abundance in the transgenic animals compared to the wild type animals. By BRISK analysis, species-specific differences included an increase in Bacteroides vulgatus abundance in HLA-B27/hβ2m and hβ2m compared to wild type rats. The finding that HLA-B27 is associated with altered cecal microbiota has not been shown before and can potentially provide a better understanding of the clinical diseases associated with this gene.

Effect of mo Content on Microstructure and Properties of Laser Cladding Fe-BASED Alloy Coatings

NASA Astrophysics Data System (ADS)

Xiaoli, Ma; Kaiming, Wang; Hanguang, Fu; Jiang, Ju; Yongping, Lei; Dawei, Yi

Mo alloying Fe-based coating was fabricated on the surface of Q235 steel by using 6 kW fiber laser. The effects of Mo additions on the microstructure, microhardness and wear resistance of the cladding layer were studied by means of optical microscopy (OM), scanning electron microscope (SEM), X-ray diffraction (XRD), energy dispersive spectrometer (EDS), Vickers hardness tester and M-200 ring block wear tester. Research results showed that the microstructure of Mo-free cladding layer mainly consisted of matrix and eutectic structure. The matrix was martensite and retained austenite. The eutectic structure mainly consisted of M2(B,C) and M7(C,B)3 type of eutectic borocarbides. With the increase of Mo content, there was no significant change in the matrix. However, the eutectic structure was transformed from M2(B,C)- and M7(C,B)3-type borocarbides into M2(B,C)-, M7(C,B)3- and M23(C,B)6-type borocarbides. When the content of Mo is 4.0wt.%, the Mo2C-type carbide appear on the matrix, and parts of the borocarbide networks are broken. The change of microhardness of the cladding layer was not obvious with the increase of Mo content. But the increase of Mo content increases the wear resistance of the cladding layer. The wear resistance of cladding layer with 4.0wt.% Mo is 2.4 times as much as the cladding layer which is Mo-free.

Identification of four novel HLA-B alleles, B*1590, B*1591, B*2726, and B*4705, from an East African population by high-resolution sequence-based typing.

PubMed

Luo, M; Mao, X; Plummer, F A

2005-02-01

We report here four novel HLA-B alleles, B*1590, B*1591, B*2726, and B*4705, identified from an East African population during sequence-based HLA-B typing. The novel alleles were confirmed by sequencing two separate polymerase chain reaction products, and by molecular cloning and sequencing multiple clones. B*1590 is identical to B*1510 at exon 2 and exon 3, except for a difference (GCCGTC) at codon 158. Sequence differences at codon 152 (GAGGTG) and codon 167 (TGGTCG) differentiate B*1591 from B*1503 at exon 3. B*2726 is identical to B*2708 at exon 2 and exon 3, except for a difference (AAGCAG) at codon 70. B*4705 was identified in three Kenyan women. The allele is identical to B*47010101/02 at exon 2 and exon 3, except for differences at codon 97 (AGGAAT) and codon 99 (TTTTAT). These new alleles have been named by the WHO Nomenclature Committee. Identification of these novel HLA-B alleles reflects the genetic diversity of this East African population.

Bradykinin induced a positive chronotropic effect via stimulation of T- and L-type calcium currents in heart cells.

PubMed

El-Bizri, Nesrine; Bkaily, Ghassan; Wang, Shimin; Jacques, Danielle; Regoli, Domenico; D'Orléans-Juste, Pedro; Sukarieh, Rami

2003-03-01

Using Fluo-3 calcium dye confocal microscopy and spontaneously contracting embryonic chick heart cells, bradykinin (10(-10) M) was found to induce positive chronotropic effects by increasing the frequency of the transient increase of cytosolic and nuclear free Ca2+. Pretreatment of the cells with either B1 or B2 receptor antagonists (R126 and R817, respectively) completely prevented bradykinin (BK) induced positive chronotropic effects on spontaneously contracting single heart cells. Using the whole-cell voltage clamp technique and ionic substitution to separate the different ionic current species, our results showed that BK (10(-6) M) had no effect on fast Na+ inward current and delayed outward potassium current. However, both L- and T-type Ca2+ currents were found to be increased by BK in a dose-dependent manner (10(-10)-10(-7) M). The effects of BK on T- and L-type Ca2+ currents were partially blocked by the B1 receptor antagonist [Leu8]des-Arg9-BK (R592) (10(-7) M) and completely reversed by the B2 receptor antagonist D-Arg[Hyp3,D-Phe7,Leu8]BK (R-588) (10(-7) M) or pretreatment with pertussis toxin (PTX). These results demonstrate that BK induced a positive chronotropic effect via stimulation of T- and L-type Ca2+ currents in heart cells mainly via stimulation of B2 receptor coupled to PTX-sensitive G-proteins. The increase of both types of Ca2+ current by BK in heart cells may explain the positive inotropic and chronotropic effects of this hormone.

Serum Vitamin B12 Levels in Type 2 Diabetes Patients on Metformin Compared to those Never on Metformin: A Cross-sectional Study.

PubMed

Raizada, Nishant; Jyotsna, Viveka P; Sreenivas, Vishnubhatla; Tandon, Nikhil

2017-01-01

There are limited data about the effect of metformin use on serum Vitamin B12 levels in type 2 diabetes patients from India. We studied serum Vitamin B12 levels in patients with type 2 diabetes mellitus who were receiving metformin and compared them to those never treated with metformin. A total of 183 patients ("metformin" group 121, "no metformin" group 63) of type 2 diabetes from the endocrinology clinic of a tertiary care center in North India were studied. Serum Vitamin B12 levels were measured in all patients. Diabetic neuropathy symptom score (DNS) and diabetic neuropathy examination score (DNE) were used to assess peripheral neuropathy while hemoglobin and mean corpuscular volume (MCV) were used to assess anemia. The serum Vitamin B12 levels were 267.7 ± 194.4 pmol/l in metformin group and 275.1 ± 197.2 pmol/l in the no metformin group ( P = 0.78). When adjusted for duration of diabetes, metformin use was associated with a 87.7 ± 37.7 pmol/l (95% confidence interval [CI], -162.1--3.3, P = 0.02) lower serum Vitamin B12 levels. No significant increase in the prevalence of neuropathy (DNS and DNE scores), anemia, or MCV was found in the Vitamin B12 deficient patients (levels <150 pmol/l) as compared to patients with normal Vitamin B12. However, serum Vitamin B12 levels for the entire cohort were higher by 12.2 ± 3.0 pmol/l (95% CI 6.4-18.0, P < 0.001) for every 1 year increase in the duration of diabetes. Metformin use was associated with a lower serum Vitamin B12 levels when adjusted for duration of diabetes. Increasing duration of diabetes was associated with higher serum Vitamin B12 levels.

The Molecular Epidemiology of the Highly Virulent ST93 Australian Community Staphylococcus aureus Strain

PubMed Central

Coombs, Geoffrey W.; Goering, Richard V.; Chua, Kyra Y. L.; Monecke, Stefan; Howden, Benjamin P.; Stinear, Timothy P.; Ehricht, Ralf; O’Brien, Frances G.; Christiansen, Keryn J.

2012-01-01

In Australia the PVL - positive ST93-IV [2B], colloquially known as “Queensland CA-MRSA” has become the dominant CA-MRSA clone. First described in the early 2000s, ST93-IV [2B] is associated with skin and severe invasive infections including necrotizing pneumonia. A singleton by multilocus sequence typing (MLST) eBURST analysis ST93 is distinct from other S aureus clones. To determine if the increased prevalence of ST93-IV [2B] is due to the widespread transmission of a single strain of ST93-IV [2B] the genetic relatedness of 58 S. aureus ST93 isolated throughout Australia over an extended period were studied in detail using a variety of molecular methods including pulsed-field gel electrophoresis, spa typing, MLST, microarray DNA, SCCmec typing and dru typing. Identification of the phage harbouring the lukS-PV/lukF-PV Panton Valentine leucocidin genes, detection of allelic variations in lukS-PV/lukF-PV, and quantification of LukF-PV expression was also performed. Although ST93-IV [2B] is known to have an apparent enhanced clinical virulence, the isolates harboured few known virulence determinants. All PVL-positive isolates carried the PVL-encoding phage ΦSa2USA and the lukS-PV/lukF-PV genes had the same R variant SNP profile. The isolates produced similar expression levels of LukF-PV. Although multiple rearrangements of the spa sequence have occurred, the core genome in ST93 is very stable. The emergence of ST93-MRSA is due to independent acquisitions of different dru-defined type IV and type V SCCmec elements in several spa-defined ST93-MSSA backgrounds. Rearrangement of the spa sequence in ST93-MRSA has subsequently occurred in some of these strains. Although multiple ST93-MRSA strains were characterised, little genetic diversity was identified for most isolates, with PVL-positive ST93-IVa [2B]-t202-dt10 predominant across Australia. Whether ST93-IVa [2B] t202-dt10 arose from one PVL-positive ST93-MSSA-t202, or by independent acquisitions of SCCmec-IVa [2B]-dt10 into multiple PVL-positive ST93-MSSA-t202 strains is not known. PMID:22900085

21 CFR 558.5 - Requirements for liquid medicated feed.

Code of Federal Regulations, 2013 CFR

2013-04-01

... Provisions § 558.5 Requirements for liquid medicated feed. (a) What types of liquid medicated feeds are covered by this section? This section covers the following types of liquid medicated feed: (1) Type B feed that is intended for further manufacture of other medicated feeds (§ 558.3(b)(3)) or: (2) Type C feed...

21 CFR 558.5 - Requirements for liquid medicated feed.

Code of Federal Regulations, 2012 CFR

2012-04-01

... Provisions § 558.5 Requirements for liquid medicated feed. (a) What types of liquid medicated feeds are covered by this section? This section covers the following types of liquid medicated feed: (1) Type B feed that is intended for further manufacture of other medicated feeds (§ 558.3(b)(3)) or: (2) Type C feed...

21 CFR 558.5 - Requirements for liquid medicated feed.

Code of Federal Regulations, 2011 CFR

2011-04-01

... Provisions § 558.5 Requirements for liquid medicated feed. (a) What types of liquid medicated feeds are covered by this section? This section covers the following types of liquid medicated feed: (1) Type B feed that is intended for further manufacture of other medicated feeds (§ 558.3(b)(3)) or: (2) Type C feed...

21 CFR 558.5 - Requirements for liquid medicated feed.

Code of Federal Regulations, 2014 CFR

2014-04-01

... Provisions § 558.5 Requirements for liquid medicated feed. (a) What types of liquid medicated feeds are covered by this section? This section covers the following types of liquid medicated feed: (1) Type B feed that is intended for further manufacture of other medicated feeds (§ 558.3(b)(3)) or: (2) Type C feed...

Aircraft Energy Conservation during Airport Ground Operations

DTIC Science & Technology

1982-03-01

minimized. The model can be run in a non -optimizing mode to simulate movements along pre-assigned taxi paths. 8-6 The model is also designed ...5.5 5.6 5.7 Engine Designation by Airline and Aircraft Type IAD 2-6 Engine Designation by Airline and Aircraft Type DCA 2-7 Fuel Flow Rates...B.2 CY 1979 Aircraft Operations at IAD and DCA Airports . . 3-5 B.3 1979 Scheduled and Non -Scheduled Departures from IAD by Aircraft Type and

Novel Animal Model of Crumbs-Dependent Progressive Retinal Degeneration That Targets Specific Cone Subtypes.

PubMed

Fu, Jinling; Nagashima, Mikiko; Guo, Chuanyu; Raymond, Pamela A; Wei, Xiangyun

2018-01-01

Human Crb1 is implicated in some forms of retinal degeneration, suggesting a role in photoreceptor maintenance. Multiple Crumbs (Crb) polarity genes are expressed in vertebrate retina, although their functional roles are not well understood. To gain further insight into Crb and photoreceptor maintenance, we compared retinal cell densities between wild-type and Tg(RH2-2:Crb2b-sfEX/RH2-2:GFP)pt108b transgenic zebrafish, in which the extracellular domain of Crb2b-short form (Crb2b-sfEX) is expressed in the retina as a secreted protein, which disrupts the planar organization of RGB cones (red, green, and blue) by interfering with Crb2a/2b-based cone-cone adhesion. We used standard morphometric techniques to assess age-related changes in retinal cell densities in adult zebrafish (3 to 27 months old), and to assess effects of the Crb2b-sfEX transgene on retinal structure and photoreceptor densities. Linear cell densities were measured in all retinal layers in radial sections with JB4-Feulgen histology. Planar (surface) densities of cones were determined in retinal flat-mounts. Cell counts from wild-type and pt108b transgenic fish were compared with both a "photoreceptor maintenance index" and statistical analysis of cell counts. Age-related changes in retinal cell linear densities and cone photoreceptor planar densities in wild-type adult zebrafish provided a baseline for analysis. Expression of Crb2b-sfEX caused progressive and selective degeneration of RGB cones, but had no effect on ultraviolet-sensitive (UV) cones, and increased numbers of rod photoreceptors. These differential responses of RGB cones, UV cones, and rods to sustained exposure to Crb2b-sfEX suggest that Crb-based photoreceptor maintenance mechanisms are highly selective.

PeaTAR1B: Characterization of a Second Type 1 Tyramine Receptor of the American Cockroach, Periplaneta americana

PubMed Central

Balfanz, Sabine

2017-01-01

The catecholamines norepinephrine and epinephrine regulate important physiological functions in vertebrates. In insects; these neuroactive substances are functionally replaced by the phenolamines octopamine and tyramine. Phenolamines activate specific guanine nucleotide-binding (G) protein-coupled receptors (GPCRs). Type 1 tyramine receptors are better activated by tyramine than by octopamine. In contrast; type 2 tyramine receptors are almost exclusively activated by tyramine. Functionally; activation of type 1 tyramine receptors leads to a decrease in the intracellular concentration of cAMP ([cAMP]i) whereas type 2 tyramine receptors can mediate Ca2+ signals or both Ca2+ signals and effects on [cAMP]i. Here; we report that the American cockroach (Periplaneta americana) expresses a second type 1 tyramine receptor (PeaTAR1B) in addition to PeaTAR1A (previously called PeaTYR1). When heterologously expressed in flpTM cells; activation of PeaTAR1B by tyramine leads to a concentration-dependent decrease in [cAMP]i. Its activity can be blocked by a series of established antagonists. The functional characterization of two type 1 tyramine receptors from P. americana; PeaTAR1A and PeaTAR1B; which respond to tyramine by changing cAMP levels; is a major step towards understanding the actions of tyramine in cockroach physiology and behavior; particularly in comparison to the effects of octopamine. PMID:29084141

PeaTAR1B: Characterization of a Second Type 1 Tyramine Receptor of the American Cockroach, Periplaneta americana.

PubMed

Blenau, Wolfgang; Balfanz, Sabine; Baumann, Arnd

2017-10-30

The catecholamines norepinephrine and epinephrine regulate important physiological functions in vertebrates. In insects; these neuroactive substances are functionally replaced by the phenolamines octopamine and tyramine. Phenolamines activate specific guanine nucleotide-binding (G) protein-coupled receptors (GPCRs). Type 1 tyramine receptors are better activated by tyramine than by octopamine. In contrast; type 2 tyramine receptors are almost exclusively activated by tyramine. Functionally; activation of type 1 tyramine receptors leads to a decrease in the intracellular concentration of cAMP ([cAMP] i ) whereas type 2 tyramine receptors can mediate Ca 2+ signals or both Ca 2+ signals and effects on [cAMP] i . Here; we report that the American cockroach ( Periplaneta americana ) expresses a second type 1 tyramine receptor (PeaTAR1B) in addition to PeaTAR1A (previously called PeaTYR1). When heterologously expressed in flpTM cells; activation of PeaTAR1B by tyramine leads to a concentration-dependent decrease in [cAMP] i . Its activity can be blocked by a series of established antagonists. The functional characterization of two type 1 tyramine receptors from P. americana ; PeaTAR1A and PeaTAR1B; which respond to tyramine by changing cAMP levels; is a major step towards understanding the actions of tyramine in cockroach physiology and behavior; particularly in comparison to the effects of octopamine.

Epstein-Barr Virus Sequence Variation—Biology and Disease

PubMed Central

Tzellos, Stelios; Farrell, Paul J.

2012-01-01

Some key questions in Epstein-Barr virus (EBV) biology center on whether naturally occurring sequence differences in the virus affect infection or EBV associated diseases. Understanding the pattern of EBV sequence variation is also important for possible development of EBV vaccines. At present EBV isolates worldwide can be grouped into Type 1 and Type 2, a classification based on the EBNA2 gene sequence. Type 1 EBV is the most prevalent worldwide but Type 2 is common in parts of Africa. Type 1 transforms human B cells into lymphoblastoid cell lines much more efficiently than Type 2 EBV. Molecular mechanisms that may account for this difference in cell transformation are now becoming clearer. Advances in sequencing technology will greatly increase the amount of whole EBV genome data for EBV isolated from different parts of the world. Study of regional variation of EBV strains independent of the Type 1/Type 2 classification and systematic investigation of the relationship between viral strains, infection and disease will become possible. The recent discovery that specific mutation of the EBV EBNA3B gene may be linked to development of diffuse large B cell lymphoma illustrates the importance that mutations in the virus genome may have in infection and human disease. PMID:25436768

10 CFR 71.33 - Package description.

Code of Federal Regulations, 2010 CFR

2010-01-01

...) Classification as Type B(U), Type B(M), or fissile material packaging; (2) Gross weight; (3) Model number; (4... absorbers or moderators, and the atomic ratio of moderator to fissile constituents; (5) Maximum normal...

Esculetin prevents non-alcoholic fatty liver in diabetic mice fed high-fat diet.

PubMed

Choi, Ra-Yeong; Ham, Ju Ri; Lee, Mi-Kyung

2016-12-25

This study investigated the effects and mechanism of esculetin (6,7-dihydroxycoumarin) on non-alcoholic fatty liver in diabetic mice fed high-fat diet (HFD). The diabetic mice model was induced by injection of streptozotocin, after which they were fed HFD diet with or without esculetin for 11 weeks. Non-diabetic mice were provided a normal diet. Diabetes induced hepatic hypertrophy, lipid accumulation and droplets; however, esculetin reversed these changes. Esculetin treatment in diabetic mice fed HFD significantly down-regulated expression of lipid synthesis genes (Fasn, Dgat2 and Plpp2) and inflammation genes (Tlr4, Myd88, Nfkb, Tnfα and Il6). Moreover, the activities of hepatic lipid synthesis enzymes (fatty acid synthase and phosphatidate phosphohydrolase) and gluconeogenesis enzyme (glucose-6-phosphatase) in the esculetin group were decreased compared with the diabetic group. In addition, esculetin significantly reduced blood HbA 1c , serum cytokines (TNF-α and IL-6) and chemokine (MCP-1) levels compared with the diabetic group without changing the insulin content in serum and the pancreas. Hepatic SOD activity was lower and lipid peroxidation level was higher in the diabetic group than in the normal group; however, esculetin attenuates these differences. Overall, these results demonstrated that esculetin supplementation could protect against development of non-alcoholic fatty liver in diabetes via regulation of lipids, glucose and inflammation. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Associations between lipid metabolism and fertility in the dairy cow.

PubMed

Wathes, D Claire; Clempson, Andrew M; Pollott, Geoff E

2012-01-01

Dairy cows mobilise body tissues to support milk production and, because glucose supplies are limited, lipids are used preferentially for energy production. Lipogenic activity is switched off and lipolytic mechanisms in adipose tissue increase through changes in the expression of several key enzymes. This results in a loss of body condition, together with high circulating concentrations of non-esterified fatty acids. Changes in the synthesis, secretion and signalling pathways of somatotrophic hormones (insulin, growth hormone, insulin-like growth factor 1) and adipokines (e.g. leptin) are central to the regulation of these processes. A high reliance on fatty acids as an energy source in the peripartum period causes oxidative damage to mitochondria in metabolically active tissues, including the liver and reproductive tract. The expression of genes involved in insulin resistance (PDK4, AHSG) is increased, together with expression of TIEG1, a transcription factor that can induce apoptosis via the mitochondrial pathway. Polymorphisms in TFAM and UCP2, two autosomal mitochondrial genes, have been associated with longevity in dairy cows. Polymorphisms in many other genes that affect lipid metabolism also show some associations with fertility traits. These include DGAT1, SCD1, DECR1, CRH, CBFA2T1, GH, LEP and NPY. Excess lipid accumulation in oocytes and the regenerating endometrium reduces fertility via reductions in embryo survival and increased inflammatory changes, respectively.

Examining the specific contributions of individual Arabidopsis metallothioneins to copper distribution and metal tolerance.

PubMed

Guo, Woei-Jiun; Meetam, Metha; Goldsbrough, Peter B

2008-04-01

Metallothioneins (MTs) are small cysteine-rich proteins found in various eukaryotes. Plant MTs are classified into four types based on the arrangement of cysteine residues. To determine whether all four types of plant MTs function as metal chelators, six Arabidopsis (Arabidopsis thaliana) MTs (MT1a, MT2a, MT2b, MT3, MT4a, and MT4b) were expressed in the copper (Cu)- and zinc (Zn)-sensitive yeast mutants, Deltacup1 and Deltazrc1 Deltacot1, respectively. All four types of Arabidopsis MTs provided similar levels of Cu tolerance and accumulation to the Deltacup1 mutant. The type-4 MTs (MT4a and MT4b) conferred greater Zn tolerance and higher accumulation of Zn than other MTs to the Deltazrc1 Deltacot1 mutant. To examine the functions of MTs in plants, we studied Arabidopsis plants that lack MT1a and MT2b, two MTs that are expressed in phloem. The lack of MT1a, but not MT2b, led to a 30% decrease in Cu accumulation in roots of plants exposed to 30 mum CuSO(4). Ectopic expression of MT1a RNA in the mt1a-2 mt2b-1 mutant restored Cu accumulation in roots. The mt1a-2 mt2b-1 mutant had normal metal tolerance. However, when MT deficiency was combined with phytochelatin deficiency, growth of the mt1a-2 mt2b-1 cad1-3 triple mutant was more sensitive to Cu and cadmium compared to the cad1-3 mutant. Together these results provide direct evidence for functional contributions of MTs to plant metal homeostasis. MT1a, in particular, plays a role in Cu homeostasis in the roots under elevated Cu. Moreover, MTs and phytochelatins function cooperatively to protect plants from Cu and cadmium toxicity.

Effect of thyroid hormone on the levels of erythrocyte carbonic anhydrase isozymes and 2,3-diphosphoglycerate in rabbits.

PubMed

Kondo, T; Taniguchi, N; Ishikawa, N; Ide, H; Takakuwa, E; Murao, M

1978-05-01

Levels of rabbit erythrocyte carbonic anhydrase B and C isozymes were determined in experimental hyperthyroidism using a quantitative immunologic technique. Levels of erythrocyte 2,3-diphosphoglycerate and protein binding iodine were simultaneously determined. Thyroxine and 3,5,3'-triiodothyronine were administered to rabbits orally for 30 days. A significant decrease in carbonic anhydrase B type was observed after 30 days, although no significant change was observed in carbonic anhydrase C type. These findings suggest that the steady state level of carbonic anhydrase B type in red cells is affected by thyroid hormone more readily than that of carbonic anhydrase C type. The level of red cell 2,3-diphosphoglycerate increased markedly after 10 days of treatment, corresponding to the increase of protein binding iodine. The clinical or pathologic significances were discussed in relation to the changes in the levels of these isozymes and 2,3-diphosphglycerate in red cells.

Docosahexaenoic Acid Modulates a HER2-Associated Lipogenic Phenotype, Induces Apoptosis, and Increases Trastuzumab Action in HER2-Overexpressing Breast Carcinoma Cells.

PubMed

Ravacci, Graziela Rosa; Brentani, Maria Mitzi; Tortelli, Tharcisio Citrângulo; Torrinhas, Raquel Suzana M M; Santos, Jéssica Reis; Logullo, Angela Flávia; Waitzberg, Dan Linetzky

2015-01-01

In breast cancer, lipid metabolic alterations have been recognized as potential oncogenic stimuli that may promote malignancy. To investigate whether the oncogenic nature of lipogenesis closely depends on the overexpression of HER2 protooncogene, the normal breast cell line, HB4a, was transfected with HER2 cDNA to obtain HER2-overexpressing HB4aC5.2 cells. Both cell lines were treated with trastuzumab and docosahexaenoic acid. HER2 overexpression was accompanied by an increase in the expression of lipogenic genes involved in uptake (CD36), transport (FABP4), and storage (DGAT) of exogenous fatty acids (FA), as well as increased activation of "de novo" FA synthesis (FASN). We further investigate whether this lipogenesis reprogramming might be regulated by mTOR/PPARγ pathway. Inhibition of the mTORC1 pathway markers, p70S6 K1, SREBP1, and LIPIN1, as well as an increase in DEPTOR expression (the main inhibitor of the mTOR) was detected in HB4aC5.2. Based on these results, a PPARγ selective antagonist, GW9662, was used to treat both cells lines, and the lipogenic genes remained overexpressed in the HB4aC5.2 but not HB4a cells. DHA treatment inhibited all lipogenic genes (except for FABP4) in both cell lines yet only induced death in the HB4aC5.2 cells, mainly when associated with trastuzumab. Neither trastuzumab nor GW9662 alone was able to induce cell death. In conclusion, oncogenic transformation of breast cells by HER2 overexpression may require a reprogramming of lipogenic genetic that is independent of mTORC1 pathway and PPARγ activity. This reprogramming was inhibited by DHA.

Utility of the ACC/AHA lesion classification as a predictor of procedural, 30-day and 12-month outcomes in the contemporary percutaneous coronary intervention era.

PubMed

Theuerle, James; Yudi, Matias B; Farouque, Omar; Andrianopoulos, Nick; Scott, Peter; Ajani, Andrew E; Brennan, Angela; Duffy, Stephen J; Reid, Christopher M; Clark, David J

2017-11-15

Correlations between the ACC/AHA coronary lesion classification and clinical outcomes in the contemporary percutaneous coronary intervention (PCI) era are not well established. We analyzed clinical characteristics and outcomes according to ACC/AHA lesion classification (A, B1, B2, C) in 13,701 consecutive patients from the Melbourne Interventional Group (MIG) registry. Patients presenting with STEMI, cardiogenic shock and out-of-hospital cardiac arrest were excluded. The primary endpoints were 30-day and 12-month mortality. Secondary endpoints were procedural success as well as 30-day and 12-month major adverse cardiac events. Of the 13,701 patients treated, 1,246 (9.1%) had type A lesions, 5,519 (40.3%) had type B1 lesions, 4,449 (32.5%) had Type B2 lesions and 2,487 (18.2%) had Type C lesions. Patients with type C lesions were more likely to be older and have impaired renal function, diabetes, previous myocardial infarction, peripheral vascular disease and prior bypass graft surgery (all P < 0.01). They were also more likely to require rotational atherectomy, drug-eluting stents and longer stent lengths (all P < 0.01). Increasing lesion complexity was associated with lower procedural success (99.6% vs. 99.1% vs. 96.6% vs. 82.7%, P < 0.001) and worse 30-day (0.2% vs. 0.3% vs. 0.7% vs. 0.6%, P < 0.001) and 12-month mortality (2.2% vs. 2.0% vs. 3.2% vs. 2.9%, P <0.01). Kaplan Meier analysis showed complex lesions (type B2 and C) had lower survival at 12-months (P = 0.003). PCI to more complex lesions continues to be associated with lower procedural success rates as well as inferior medium-term clinical outcomes. Thus the ACC/AHA lesion classification should still be calculated preprocedure to predict acute PCI success and clinical outcomes. © 2017 Wiley Periodicals, Inc.