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Sample records for human apolipoprotein ai

  1. Transport of Apolipoproteins A-I and A-II by Human Thoracic Duct Lymph

    PubMed Central

    Anderson, David W.; Schaefer, Ernst J.; Bronzert, Thomas J.; Lindgren, Frank T.; Forte, Trudy; Starzl, Thomas E.; Niblack, Gary D.; Zech, Loren A.; Brewer, H. Bryan

    1981-01-01

    The daily transport of human plasma apolipoproteins A-I and A-II, triglyceride, and total cholesterol from the thoracic duct lymph into plasma was measured in two subjects before and three subjects after renal transplantation. Lymph triglyceride transport was ∼83% of the daily ingested fat loads, whereas lymph cholesterol transport was consistently greater than the amount of daily ingested cholesterol. Lymph apolipoprotein transport significantly (P < 0.05) exceeded the predicted apolipoprotein synthesis rate by an average of 659±578 mg/d for apolipoprotein A-I and 109±59 mg/d for apolipoprotein A-II among the five subjects. It is estimated that 22-77% (apolipoprotein A-I) and 28-82% (apolipoprotein A-II) of daily total body apolipoprotein synthesis takes place in the intestine. Lymph high density lipoprotein particles are mostly high density lipoprotein2b and high density lipoprotein2a and have a greater overall relative triglyceride content and a smaller relative cholesteryl ester content when compared with homologous plasma high density lipoproteins. The major quantity of both lymph apolipoprotein A-I (81±8%) and apolipoprotein A-II (90±11%) was found within high density lipoproteins with almost all of the remainder found in chylomicrons and very low density lipoproteins. The combined results are consistent with a major contribution of the intestine to total body synthesis of apolipoprotein A-I and apolipoprotein A-II. An important role of lymph in returning filtered apolipoprotein to plasma in association with high density lipoproteins is proposed. Accompanying the return of filtered apolipoprotein to the plasma is a probable transformation, both in size and composition, of at least some of the lymph high density lipoprotein2b and high density lipoprotein2a particles into high density lipoprotein3. Images PMID:7204560

  2. Isolation and characterization of cDNA clones for human apolipoprotein A-I.

    PubMed Central

    Breslow, J L; Ross, D; McPherson, J; Williams, H; Kurnit, D; Nussbaum, A L; Karathanasis, S K; Zannis, V I

    1982-01-01

    We have isolated cDNA clones encoding human apolipoprotein (apo) A-I. Twenty putative apo A-I cDNA clones were selected by screening 10,000 clones of an adult human liver cDNA library with an oligonucleotide probe. The probe was a mixture of synthetic 14-base-long DNA oligomers constructed to correspond to the codons for apo A-I amino acids 105-109. Four of these clones were examined further and showed 600- to 800-base-pair (bp) inserts. Preliminary restriction mapping and partial DNA sequence analysis indicated that the shorter inserts were a subset of the longer DNA inserts. DNA sequence analysis of the clone with an insert of approximately equal to 600 bp, designated pAI-113, revealed that it contained a DNA sequence corresponding to apo A-I amino acids 94-243. The DNA base sequence of this clone also contained a standard termination codon, polyadenylylation signal, and poly(A) tail. Partial DNA sequence of a second clone that contained an 800-bp insert, designated pAI-107, showed that it corresponded to apo A-I amino acids 18-243 and also included the 3' untranslated region. Isolation of these cDNA clones will facilitate molecular analyses of apolipoproteins in normal and disease states. PMID:6294659

  3. Crystal structure of truncated human apolipoprotein A-I suggests a lipid-bound conformation

    PubMed Central

    Borhani, David W.; Rogers, Danise P.; Engler, Jeffrey A.; Brouillette, Christie G.

    1997-01-01

    The structure of truncated human apolipoprotein A-I (apo A-I), the major protein component of high density lipoprotein, has been determined at 4-Å resolution. The crystals comprise residues 44–243 (exon 4) of apo A-I, a fragment that binds to lipid similarly to intact apo A-I and that retains the lipid-bound conformation even in the absence of lipid. The molecule consists almost entirely of a pseudo-continuous, amphipathic α-helix that is punctuated by kinks at regularly spaced proline residues; it adopts a shape similar to a horseshoe of dimensions 125 × 80 × 40 Å. Four molecules in the asymmetric unit associate via their hydrophobic faces to form an antiparallel four-helix bundle with an elliptical ring shape. Based on this structure, we propose a model for the structure of apo A-I bound to high density lipoprotein. PMID:9356442

  4. Structural models of human apolipoprotein A-I: a critical analysis and review.

    PubMed

    Brouillette, C G; Anantharamaiah, G M; Engler, J A; Borhani, D W

    2001-03-30

    Human apolipoprotein (apo) A-I has been the subject of intense investigation because of its well-documented anti-atherogenic properties. About 70% of the protein found in high density lipoprotein complexes is apo A-I, a molecule that contains a series of highly homologous amphipathic alpha-helices. A number of significant experimental observations have allowed increasing sophisticated structural models for both the lipid-bound and the lipid-free forms of the apo A-I molecule to be tested critically. It seems clear, for example, that interactions between amphipathic domains in apo A-I may be crucial to understanding the dynamic nature of the molecule and the pathways by which the lipid-free molecule binds to lipid, both in a discoidal and a spherical particle. The state of the art of these structural studies is discussed and placed in context with current models and concepts of the physiological role of apo A-I and high-density lipoprotein in atherosclerosis and lipid metabolism. PMID:11278170

  5. Production and Analysis of Biological Properties of Recombinant Human Apolipoprotein A-I.

    PubMed

    Ryabchenko, A V; Kotova, M V; Tverdohleb, N V; Knyazev, R A; Polyakov, L M

    2015-11-01

    Production of recombinant human apolipoprotein A-I (apoA-I) in E. coli cells is described and its biological properties are compared with those of natural protein. Recombinant apoA-I was isolated as a chimeric polypeptide and then processed to a mature form apoA-I (rapo-I). We studied the ability of the resulting protein to penetrate into hepatocyte nuclei and regulate the rate of DNA biosynthesis in complex with estriol. Penetration of rapoA-I conjugated with FITC into hepatocyte nuclei was demonstrated. rapoA-I-estriol and apoA-I-estriol complexes induced similar increase in DNA biosynthesis rate in isolated hepatocytes, which confi rms functional similarity of the obtained recombinant mature protein (rapoA-I) and native human apoA-I. PMID:26612626

  6. A complete backbone spectral assignment of human apolipoprotein AI on a 38 kDa preβHDL (Lp1-AI) particle

    SciTech Connect

    Ren, Xuefeng; Yang, Yunhuang; Neville, T.; Hoyt, David W.; Sparks, Daniel L.; Wang, Jianjun

    2007-06-12

    Apolipoprotein A-I (apoAI, 243-residues) is the major protein component of the high-density lipoprotein (HDL) that has been a hot subject of interests because of its anti-atherogenic properties. This important property of apoAI is related to its roles in reverse cholesterol transport pathway. Upon lipid-binding, apoAI undergoes conformational changes from lipid-free to several different HDL-associated states (1). These different conformational states regulate HDL formation, maturation and transportation. Two initial conformational states of apoAI are lipid-free apoAI and apoAI/preβHDL that recruit phospholipids and cholesterol to form HDL particles. In particular, lipid-free apoAI specifically binds to phospholipids to form lipid-poor apoAI, including apoAI/preβ-HDL (~37 kDa). As a unique class of lipid poor HDL, both in vitro and in vivo evidence demonstrates that apoAI/preβ-HDLs are the most effective acceptors specifically for free cholesterol in human plasma and serves as the precursor of HDL particles (2). Here we report a complete backbone spectral assignment of human apoAI/preβHDL. Secondary structure prediction using backbone NMR parameters indicates that apoAI/preβHDL displays a two-domain structure: the N-terminal four helix-bundle domain (residues 1-186) and the C-terminal flexible domain (residues 187-243). A structure of apoAI/preβ-HDL is the first lipid-associated structure of apoAI and is critical for us to understand how apoAI recruits cholesterol to initialize HDL formation. BMRB deposit with accession number: 15093.

  7. Helical structure and stability in human apolipoprotein A-I by hydrogen exchange and mass spectrometry.

    PubMed

    Chetty, Palaniappan Sevugan; Mayne, Leland; Lund-Katz, Sissel; Stranz, David; Englander, S Walter; Phillips, Michael C

    2009-11-10

    Apolipoprotein A-I (apoA-I) stabilizes anti-atherogenic high density lipoprotein particles (HDL) in the circulation and governs their biogenesis, metabolism, and functional interactions. To decipher these important structure-function relationships, it will be necessary to understand the structure, stability, and plasticity of the apoA-I molecule. Biophysical studies show that lipid-free apoA-I contains a large amount of alpha-helical structure but the location of this structure and its properties are not established. We used hydrogen-deuterium exchange coupled with a fragmentation-separation method and mass spectrometric analysis to study human lipid-free apoA-I in its physiologically pertinent monomeric form. The acquisition of approximately 100 overlapping peptide fragments that redundantly cover the 243-residue apoA-I polypeptide made it possible to define the positions and stabilities of helical segments and to draw inferences about their interactions and dynamic properties. Residues 7-44, 54-65, 70-78, 81-115, and 147-178 form alpha-helices, accounting for a helical content of 48 +/- 3%, in agreement with circular dichroism measurements (49%). At 3 to 5 kcal/mol in free energy of stabilization, the helices are far more stable than could be achieved in isolation, indicating mutually stabilizing helix bundle interactions. However the helical structure is dynamic, unfolding and refolding in seconds, allowing facile apoA-I reorganization during HDL particle formation and remodeling. PMID:19850866

  8. The Conformation of Lipid-Free Human Apolipoprotein A-I in Solution

    PubMed Central

    Pollard, Ricquita D.; Fulp, Brian; Samuel, Michael P.; Sorci-Thomas, Mary G.; Thomas, Michael J.

    2014-01-01

    Apolipoprotein AI (apoA-I) is the principal acceptor of lipids from ATP-binding cassette transporter A1, a process that yields nascent high density lipoproteins. Analysis of lipidated apoA-I conformation yields a belt or twisted belt in which two strands of apoA-I lie antiparallel to one another. In contrast, biophysical studies have suggested that a part of lipid-free apoA-I was arranged in a 4-helix bundle. To understand how lipid-free apoA-I opens from a bundle to a belt while accepting lipid it was necessary to have a more refined model for the conformation of lipid-free apoA-I. This study reports the conformation of lipid-free human apoA-I using lysine-to-lysine chemical cross-linking in conjunction with disulfide cross-linking achieved using selective cysteine mutations. After proteolysis cross-linked peptides were verified by sequencing using tandem mass spectrometry. The resulting structure is compact with roughly 4 helical regions, amino acids 44 through 186, bundled together. C- and N-terminal ends, amino acids 1-43 and 187-243, respectively, are folded such that they lie close to one another. An unusual feature of the molecule is the high degree of connectivity of lysine40 with 6 other lysines, lysines that are close, e.g., lysine59, to distant lysines, e.g., lysine239, that are at the opposite end of the primary sequence. These results are compared and contrasted with other reported conformations for lipid-free human apoA-I and an NMR study of mouse apoA-I. PMID:24308268

  9. Sp and GATA factors are critical for Apolipoprotein AI downstream enhancer activity in human HepG2 cells.

    PubMed

    Ivanov, Gleb S; Kater, Jessie M; Jha, Shivkumar H; Stutius, Erica A; Sabharwal, Ravleen; Tricarico, Marisa D; Ginsburg, Geoffrey S; Ozer, Josef S

    2003-12-24

    The factors that bind to the hepatic-specific human apolipoprotein AI (apoAI) 48-bp downstream enhancer (DSE) were identified and characterized by electrophoretic mobility shift assays. A significant homology was shown between the histone 4 (H4) promoters and the hepatic-specific human apoAI DSE at Sp1 and H4TF2 binding sites. Human HepG2 nuclear extracts were used to form four specific complexes with the DSE (referred to as apoAI DSE-1, -2, -3, and -4). The apoAI DSE-1 and -2 complexes showed similar binding specificity to the Sp/H4TF1 consensus site within the apoAI DSE. The apoAI DSE-1 complex was predominantly recognized by anti-Sp1 and Sp3 sera in gel shift assays, indicating that the DSE was recognized by multiple Sp family members. Nuclear extracts that were prepared from retinoic acid treated HepG2 cells showed increased levels of Sp factors in gel shift and Western blot assays. The apoAI DSE-2 complex was identified as H4TF1 and formed in the absence of magnesium chloride. The apoAI DSE-3 complex bound to a consensus GATA element within the DSE that was recognized by recombinant human GATA-6 as well. The apoAI DSE-3 complex was completely disrupted by a GATA-4 antibody in EMSA. GATA-4 and -6 were detected in nuclear extracts prepared from retinoic acid treated HepG2 cells using Western blot assays. The highest apoAI DSE-3 levels were observed with retinoic acid treated HepG2 cell nuclear extracts in EMSA. ApoAI DSE-4 is a multi-factor complex that includes an Sp/H4TF1 factor and either H4TF2 or apoAI DSE-3. Because apoAI DSE mutations revealed transcription defects in transient transfection assays, we conclude that the entire DSE sequence is required for full apoAI transcriptional activity in HepG2 cells. PMID:14659877

  10. Effects of red grape juice consumption on high density lipoprotein-cholesterol, apolipoprotein AI, apolipoprotein B and homocysteine in healthy human volunteers.

    PubMed

    Khadem-Ansari, Mohammad H; Rasmi, Yousef; Ramezani, Fatemeh

    2010-01-01

    It has suggested that grape juice consumption has lipid- lowering effect and it is associated with a decreased risk of heart disease. We aimed to evaluate the effects of red grape juice (RGj) consumption on high density lipoprotein-cholesterol (HDL-C), apolipoprotein AI (apoAI), apolipoprotein B (apoB) and homocysteine (Hcy) levels in healthy human volunteers. Twenty six healthy and nonsmoking males, aged between 25-60 years, who were under no medication asked to consume 150 ml of RGj twice per day for one month. Serum HDL-C, apoAI, apoB and plasma Hcy levels were measured before and after one month RGj consumption. HDL-C levels after RGj consumption were significantly higher than the corresponding levels before the RGj consumption (41.44 ± 4.50 and 44.37 ± 4.30 mg/dl; P<0.0001). Also, apoB was significantly increased after RGj consumption (149.0 ± 22.35 and 157.19 ± 18.60 mg/dl; P<0.002). But apoAI levels were not changed significantly before and after of RGj consumption (154.27 ± 21.55 and 155.35 ± 21.07 mg/dl; P>0.05). Hcy levels were decreased after RGj consumption (7.70 ± 2.80 and 6.20 ± 2.30 µmol/l; P<0.001). The present study demonstrates that RGj consumption can significantly increase serum HDL-C levels and decrease Hcy levels. These findings may have important implications for the prevention of atherosclerosis in healthy individuals. PMID:21633724

  11. Different cis-acting DNA elements control expression of the human apolipoprotein AI gene in different cell types

    SciTech Connect

    Sastry, K.; Seedorf, U.; Karathanasis, S.K.

    1988-02-01

    In mammals, the gene coding for apolipoprotein AI (apoAI), a protein of the plasma lipid transport system, is expressed only in the liver and the intestine. A series of plasmids containing various lengths of sequences flanking the 5' end of the human apoAI gene were constructed and assayed for transient expression after introduction into cultured human hepatoma 9HepG2), colon carcinoma (Caco-2), and epithelial (HeLa) cells. The results showed that while most of these constructs are expressed in HepG2 and Caco-2 cells, none of them is expressed in HeLa cells. In addition, the results indicated that a DNA segment located between nucleotides -256 and -41 upstream from the transcription start site of this gene is necessary and sufficient for maximal levels of expression in HepG2 but not in Caco-2 cells, while a DNA segment located between nucleotides -2052 and -192 is required for maximal levels of expression in Caco-2 cells. Moreover, it was shown that the -256 to -41 DNA segment functions as a hepatoma cell-specific transcriptional enhancer with both homologous and heterologous promoters. These results indicate that different cis- and possibly trans-acting factors are involved in the establishment and subsequent regulation of expression of the apoAI gene in the mammalian liver and intestine.

  12. Effect of TNF{alpha} on activities of different promoters of human apolipoprotein A-I gene

    SciTech Connect

    Orlov, Sergey V.; Mogilenko, Denis A.; Shavva, Vladimir S.; Dizhe, Ella B.; Ignatovich, Irina A.; Perevozchikov, Andrej P.

    2010-07-23

    Research highlights: {yields} TNF{alpha} stimulates the distal alternative promoter of human apoA-I gene. {yields} TNF{alpha} acts by weakening of promoter competition within apoA-I gene (promoter switching). {yields} MEK1/2 and nuclear receptors PPAR{alpha} and LXRs take part in apoA-I promoter switching. -- Abstract: Human apolipoprotein A-I (ApoA-I) is a major structural and functional protein component of high-density lipoproteins. The expression of the apolipoprotein A-I gene (apoA-I) in hepatocytes is repressed by pro-inflammatory cytokines such as IL-1{beta} and TNF{alpha}. Recently, two novel additional (alternative) promoters for human apoA-I gene have been identified. Nothing is known about the role of alternative promoters in TNF{alpha}-mediated downregulation of apoA-I gene. In this article we report for the first time about the different effects of TNF{alpha} on two alternative promoters of human apoA-I gene. Stimulation of HepG2 cells by TNF{alpha} leads to activation of the distal alternative apoA-I promoter and downregulation of the proximal alternative and the canonical apoA-I promoters. This effect is mediated by weakening of the promoter competition within human apoA-I 5'-regulatory region (apoA-I promoter switching) in the cells treated by TNF{alpha}. The MEK1/2-ERK1/2 cascade and nuclear receptors PPAR{alpha} and LXRs are important for TNF{alpha}-mediated apoA-I promoter switching.

  13. Apolipoprotein A-I and Cancer

    PubMed Central

    Zamanian-Daryoush, Maryam; DiDonato, Joseph A.

    2015-01-01

    High-density lipoprotein (HDL) and apolipoprotein A-I (apoA-I), the predominant protein in plasma HDL, have long been the focus of intense studies in the field of atherosclerosis and cardiovascular disease. ApoA-I, in large part, is responsible for HDL assembly and its main atheroprotective function, that of shuttling excess cholesterol from peripheral tissues to the liver for excretion (reverse cholesterol transport). Recently, a protective role for HDL in cancer was suggested from several large clinical studies where an inverse relationship between plasma HDL-cholesterol (HDL-C) levels and risk of developing cancer was noted. This notion has now been tested and found to be supported in mouse tumor studies, where increasing levels of apoA-I/HDL were discovered to protect against tumor development and provision of human apoA-I was therapeutic against established tumors. This mini-review discusses the emerging role of apoA-I in tumor biology and its potential as cancer therapeutic. PMID:26617517

  14. Carboxyl-Terminal Cleavage of Apolipoprotein A-I by Human Mast Cell Chymase Impairs Its Anti-Inflammatory Properties

    PubMed Central

    Nguyen, Su Duy; Maaninka, Katariina; Lappalainen, Jani; Nurmi, Katariina; Metso, Jari; Öörni, Katariina; Navab, Mohamad; Fogelman, Alan M.; Jauhiainen, Matti; Lee-Rueckert, Miriam

    2016-01-01

    Objective— Apolipoprotein A-I (apoA-I) has been shown to possess several atheroprotective functions, including inhibition of inflammation. Protease-secreting activated mast cells reside in human atherosclerotic lesions. Here we investigated the effects of the neutral proteases released by activated mast cells on the anti-inflammatory properties of apoA-I. Approach and Results— Activation of human mast cells triggered the release of granule-associated proteases chymase, tryptase, cathepsin G, carboxypeptidase A, and granzyme B. Among them, chymase cleaved apoA-I with the greatest efficiency and generated C-terminally truncated apoA-I, which failed to bind with high affinity to human coronary artery endothelial cells. In tumor necrosis factor-α–activated human coronary artery endothelial cells, the chymase-cleaved apoA-I was unable to suppress nuclear factor-κB–dependent upregulation of vascular cell adhesion molecule-1 (VCAM-1) and to block THP-1 cells from adhering to and transmigrating across the human coronary artery endothelial cells. Chymase-cleaved apoA-I also had an impaired ability to downregulate the expression of tumor necrosis factor-α, interleukin-1β, interleukin-6, and interleukin-8 in lipopolysaccharide-activated GM-CSF (granulocyte-macrophage colony-stimulating factor)– and M-CSF (macrophage colony-stimulating factor)–differentiated human macrophage foam cells and to inhibit reactive oxygen species formation in PMA (phorbol 12-myristate 13-acetate)–activated human neutrophils. Importantly, chymase-cleaved apoA-I showed reduced ability to inhibit lipopolysaccharide-induced inflammation in vivo in mice. Treatment with chymase blocked the ability of the apoA-I mimetic peptide L-4F, but not of the protease-resistant D-4F, to inhibit proinflammatory gene expression in activated human coronary artery endothelial cells and macrophage foam cells and to prevent reactive oxygen species formation in activated neutrophils. Conclusions— The

  15. Comparison of deuterated leucine, valine, and lysine in the measurement of human apolipoprotein A-I and B-100 kinetics

    SciTech Connect

    Lichtenstein, A.H.; Cohn, J.S.; Hachey, D.L.; Millar, J.S.; Ordovas, J.M.; Schaefer, E.J. )

    1990-09-01

    The production rates of apolipoprotein (apo)B-100 in very low density lipoprotein and in low density lipoprotein and apolipoprotein A-I in high density lipoprotein were determined using a primed-constant infusion of (5,5,5,-2H3)leucine, (4,4,4,-2H3)valine, and (6,6-2H2,1,2-13C2)lysine. The three stable isotope-labeled amino acids were administered simultaneously to determine whether absolute production rates calculated using a stochastic model were independent of the tracer species utilized. Three normolipidemic adult males were studied in the constantly fed state over a 15-h period. The absolute production rates of very low density lipoprotein apoB-100 were 11.4 +/- 5.8 (leucine), 11.2 +/- 6.8 (valine), and 11.1 +/- 5.4 (lysine) mg per kg per day (mean +/- SDM). The absolute production rates for low density lipoprotein apoB-100 were 8.0 +/- 4.7 (leucine), 7.5 +/- 3.8 (valine), and 7.5 +/- 4.2 (lysine) mg per kg per day. The absolute production rates for high density lipoprotein apoA-I were 9.7 +/- 0.2 (leucine), 9.4 +/- 1.7 (valine), and 9.1 +/- 1.3 (lysine) mg per kg per day. There were no statistically significant differences in absolute synthetic rates of the three apolipoproteins when the plateau isotopic enrichment values of very low density lipoprotein apoB-100 were used to define the isotopic enrichment of the intracellular precursor pool. Our data indicate that deuterated leucine, valine, or lysine provided similar results when used for the determination of apoA-I and apoB-100 absolute production rates within plasma lipoproteins as part of a primed-constant infusion protocol.

  16. Expression of the human apolipoprotein A-I gene in transgenic mice alters high density lipoprotein (HDL) particle size distribution and diminishes selective uptake of HDL cholesteryl esters

    SciTech Connect

    Chajekshaul, T.; Hayek, T.; Walsh, A.; Breslow, J.L. )

    1991-08-01

    Transgenic mice carrying the human apolipoprotein (apo) A-I gene (HuAITg mice) were used to examine the effects of overexpression of the human gene on high density lipoprotein (HDL) particle size distribution and metabolism. On a chow diet, control mice had HDL cholesterol and apo A-I levels of 49 {plus minus} 2 and 137 {plus minus} 12 mg/dl of plasma, respectively. HuAITg mice had HDL cholesterol, human apo A-I, and mouse apo A-I levels of 88 {plus minus} 2, 255 {plus minus} 19, and 16 {plus minus} 2 mg/dl, respectively. Nondenaturing gradient gel electrophoresis revealed control mouse plasma HDL to be primarily monodisperse with a particle diameter of 10.2 nm, whereas HuAITg mouse plasma HDL was polydisperse with particles of diameter 11.4, 10.2, and 8.7 nm, which correspond in size to human HDL1, HDL2, and HDL3, respectively. In vivo turnover studies of HDL labeled with (3H)cholesteryl linoleyl ether and 125I-apo A-I were performed. In control animals, the fractional catabolic rate (FCR) for HDL cholesteryl ester was significantly more than the apo A-I FCR. In the HuAITg mice, the HDL cholesteryl ester FCR was the same as the apo A-I FCR. There were no significant differences between control and HuAITg animals in the sites of tissue removal of HDL cholesteryl ester, with the liver extracting most of the injected radioactivity. Control and HuAITg animals had comparable liver and intestinal cholesterol synthesis and LDL FCR. In conclusion, HuAITg mice have principally human and not mouse apo A-I in their plasma. This apparently causes a change in HDL particle size distribution in the transgenic mice to one resembling the human pattern. The replacement of mouse by human apo A-I also apparently causes the loss of the selective uptake pathway of HDL cholesteryl esters present in control mice.

  17. Apolipoprotein A-I: A Molecule of Diverse Function.

    PubMed

    Mangaraj, Manaswini; Nanda, Rachita; Panda, Suchismita

    2016-07-01

    Apolipoprotein A-I (apo A-I) an indispensable component and a major structural protein of high-density lipoprotein (HDL), plays a vital role in reverse cholesterol transport and cellular cholesterol homeostasis since its identification. Its multifunctional role in immunity, inflammation, apoptosis, viral, bacterial infection etc. has crossed its boundary of its potential of protecting cardiovascular system and lowering cardiovascular disease risk, attributing HDL to be known as a protective fat removal particle. Its structural homology with prostacyclin stabilization factor has contributed to its anti-clotting and anti-aggregatory effect on platelet which has potentiated its cardio-protective role as well as its therapeutic efficacy against Alzheimer's disease. The binding affinity and neutralising action against endotoxin lipopolysaccharide, reduces the toxic manifestations of septic shock. As a negative acute phase protein, it blocks T-cell signalling of macrophages. However the recently identified anti-tumor activity of apo A-I has been highlighted in various models of melanoma, lung cancer, ovarian cancer, lymphoblastic leukaemia, gastric as well as pancreatic cancers. These cancer fighting effects are directed towards regression of tumor size and distant metastasis by its immuno modulatory activity as well as its clearing effect on serum lysophospholipids. This lowering effect on lysophospholipid concentration is utilized by apo A-I mimetic peptides to be used in retarding tumor cell proliferation and as a potential cancer therapeutic agent. Not only that, it inhibits the tumor associated neo-angiogenesis as well as brings down the matrix degrading enzymes associated with tumor metastasis. However this efficient therapeutic potential of apo A-I as an anti tumor agent awaits further future experimental studies in humans. PMID:27382195

  18. Docosahexaenoic acid suppresses apolipoprotein A-I gene expression through hepatocyte nuclear factor-3beta

    Technology Transfer Automated Retrieval System (TEKTRAN)

    BACKGROUND: Dietary fish-oil supplementation has been shown in human kinetic studies to lower the production rate of apolipoprotein (apo) A-I, the major protein component of HDL. The underlying mechanism responsible for this effect is not fully understood. OBJECTIVE: We investigated the effect and...

  19. Apolipoprotein A-I variants. Naturally occurring substitutions of proline residues affect plasma concentration of apolipoprotein A-I.

    PubMed Central

    von Eckardstein, A; Funke, H; Henke, A; Altland, K; Benninghoven, A; Assmann, G

    1989-01-01

    Six unrelated families with genetically determined structural variants of apo A-I were found in the course of an electrophoretic screening program for apo A-I variants in dried blood samples of newborns. The following structural variations were identified by the combined use of HPLC, time-of-flight secondary ion mass spectrometry (TOF-SIMS), and automated gas phase sequencing: Pro3----Arg (1x), Pro4----Arg (1x), and Pro165----Arg (4x). All variant carriers were heterozygous for their mutant of apo A-I. Subjects heterozygous for apo A-I(Pro165----Arg) (n = 12) were found to exhibit lower mean values for apo A-I (109 +/- 16 mg/dl) and HDL cholesterol (37 +/- 9 mg/dl) than unaffected family members (n = 9): 176 +/- 41 and 64 +/- 18 mg/dl, respectively (P less than 0.001). In 9 of 12 apo A-I(Pro165----Arg) variant carriers the concentrations of apo A-I were below the fifth percentile of sex-matched controls. By two-dimensional immunoelectrophoresis as well as by densitometry the relative concentration of the variant apo A-I in heterozygous carriers of apo A-I(Pro165----Arg) was determined to account for only 30% of the total plasma apo A-I mass instead of the expected 50%. Thus, the observed apo A-I deficiency may be largely a consequence of the decreased concentration of the variant apo A-I. In the case of the apo A-I(Pro3----Arg) mutant, densitometry of HDL apolipoproteins demonstrated a distinctly increased concentration of the variant proapo A-I relative to normal proapo A-I. This phenomenon was not observed in the apo A-I(Pro4----Arg) mutant or in other mutants. This suggests that the interspecies conserved proline residue in position 3 of mature apo A-I is functionally important for the regular enzymatic conversion of proapo A-I to mature apo A-I. Images PMID:2512329

  20. Emerging Roles of Apolipoprotein E and Apolipoprotein A-I in the Pathogenesis and Treatment of Lung Disease.

    PubMed

    Yao, Xianglan; Gordon, Elizabeth M; Figueroa, Debbie M; Barochia, Amisha V; Levine, Stewart J

    2016-08-01

    Emerging roles are being recognized increasingly for apolipoproteins in the pathogenesis and treatment of lung diseases on the basis of their ability to suppress inflammation, oxidative stress, and tissue remodeling, and to promote adaptive immunity and host defense. Apolipoproteins, such as apolipoprotein E (apoE) and apolipoprotein A-I (apoA-I), are important components of lipoprotein particles that facilitate the transport of cholesterol, triglycerides, and phospholipids between plasma and cells. ApoE-containing lipoprotein particles are internalized into cells by low-density lipoprotein receptors (LDLRs), whereas apoA-I can interact with the ATP-binding cassette subfamily A member 1 (ABCA1) transporter to efflux cholesterol and phospholipids out of cells. ApoE and apoA-I also mediate receptor-independent effects, such as binding to and neutralizing LPS. Both apoE and apoA-I are expressed by lung cells, which allows apoE/LDLR- and apoA-I/ABCA1-dependent pathways to modulate normal lung health and the pathogenesis of respiratory diseases, including asthma, acute lung injury, cancer, emphysema, pulmonary fibrosis, and pulmonary hypertension. Data from human studies and research using experimental murine model systems have shown that both apoE and apoA-I pathways play primarily protective roles in lung biology and respiratory disease. Furthermore, apolipoprotein mimetic peptides, corresponding to the LDLR-binding domain of apoE or the class A amphipathic α-helical structure of apoA-I, have antiinflammatory and antioxidant effects that attenuate the severity of lung disease in murine models. Thus, the development of inhaled apolipoprotein mimetic peptides as a novel treatment paradigm could represent a significant advance for patients with respiratory disease who do not respond to current therapies. PMID:27073971

  1. The structure of human high density lipoprotein and the levels of apolipoprotein A-I in plasma as determined by radioimmunoassay.

    PubMed

    Schonfeld, G; Pfleger, B

    1974-08-01

    The major apoprotein of high density lipoprotein is apolipoprotein A-I (ApoA-I). In addition to being a structural component of this class of lipoproteins, ApoA-I also has a physiologic role as an activator of lecithin-cholesterol acyl transferase, an enzyme important in the metabolism of all lipoproteins. To measure ApoA-I content in human plasma, to assess its immunologic activity in hyperlipoproteinemia, and to carry out certain structural studies of high density lipoproteins, we have developed a double antibody radioimmunoassay. ApoA-I, isolated by gel filtration, was used to produce monospecific antisera. ApoA-I was iodinated by chloramine-T and the resulting [(125)I]-ApoA-I was purified by gel filtration. > 85% of [(125)I]-ApoA-I was precipitated by antibody, and 90% of bound [(125)I]ApoA-I was displaced by "cold" ApoA-I. Other lipoproteins and apoproteins did not react. Plasma and high density lipoprotein from normals and subjects with hyperlipoproteinemia displaced counts in parallel with ApoA-I, suggesting that the same antigenic determinants were reacting with antibody on lipid-free and lipid-associated ApoA-I. However, less than 5% of ApoA-I of high density lipoprotein reacted in the assay. Removal of the lipid by extraction increased the reactivity of ApoA-I in high density lipoprotein 15-20-fold; thus more than 95% of the ApoA-I molecules in "intact" high density lipoprotein are unreactive with antibody. Normal and hyperlipoproteinemic plasma and high density lipoproteins isolated from the same subjects continued to display parallelism with ApoA-I standard after lipid extraction, suggesting that ApoA-I of normal and hyperliproteinemic subjects are immunologically identical. About 90% of ApoA-I was in the d 1.063-1.21 fractions of normal plasma, trace quantities were found in the lipoproteins of d < 1.063, and the rest (about 10%) was in the d > 1.21 fraction. Normal plasma levels, assessed in extracted plasmas with a precision of 8%, were 100+/-35 mg

  2. Ictalurus punctatus apolipoprotein A-I (ApoA1) mRNA, complete cds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The complete coding sequence of channel catfish apolipoprotein A-I is 777 bp in length, encoding 258 amino acids. The publishing of this coding sequence will also allow phylogenetic comparison between catfish ApoAI and ApoAI genes from other species. The availability of this complete coding sequence...

  3. Apolipoprotein AI Deficiency Inhibits Serum Opacity Factor Activity against Plasma High Density Lipoprotein via a Stabilization Mechanism

    PubMed Central

    Rosales, Corina; Patel, Niket; Gillard, Baiba K.; Yelamanchili, Dedipya; Yang, Yaliu; Courtney, Harry S.; Santos, Raul D.; Gotto, Antonio M.; Pownall, Henry J.

    2016-01-01

    The reaction of Streptococcal serum opacity factor (SOF) against plasma high-density lipoproteins (HDL) produces a large cholesteryl ester-rich microemulsion (CERM), a smaller neo HDL that is apolipoprotein (apo) AI-poor, and lipid-free apo AI. SOF is active vs. both human and mouse plasma HDL. In vivo injection of SOF into mice reduces plasma cholesterol ~40% in 3 hours while forming the same products observed in vitro, but at different ratios. Previous studies supported the hypothesis that labile apo AI is required for the SOF reaction vs. HDL. Here we further tested that hypothesis by studies of SOF against HDL from apo AI-null mice. When injected into apo AI-null mice, SOF reduced plasma cholesterol ~35% in three hours. The reaction of SOF vs. apo AI-null HDL in vitro produced a CERM and neo HDL, but no lipid-free apo. Moreover, according to the rate of CERM formation, the extent and rate of the SOF reaction vs. apo AI-null mouse HDL was less than that against wild-type (WT) mouse HDL. Chaotropic perturbation studies using guanidine hydrochloride showed that apo AI-null HDL was more stable than WT HDL. Human apo AI added to apo AI-null HDL was quantitatively incorporated, giving reconstituted HDL. Both SOF and guanidine hydrochloride displaced apo AI from the reconstituted HDL. These results support the conclusion that apo AI-null HDL is more stable than WT HDL because it lacks apo AI, a labile protein that is readily displaced by physico-chemical and biochemical perturbations. Thus, apo AI-null HDL is less SOF-reactive than WT HDL. The properties of apo AI-null HDL can be partially restored to those of WT HDL by the spontaneous incorporation of human apo AI. It remains to be determined what other HDL functions are affected by apo AI deletion. PMID:25790332

  4. Apolipoprotein AI deficiency inhibits serum opacity factor activity against plasma high density lipoprotein via a stabilization mechanism.

    PubMed

    Rosales, Corina; Patel, Niket; Gillard, Baiba K; Yelamanchili, Dedipya; Yang, Yaliu; Courtney, Harry S; Santos, Raul D; Gotto, Antonio M; Pownall, Henry J

    2015-04-14

    The reaction of Streptococcal serum opacity factor (SOF) against plasma high-density lipoproteins (HDL) produces a large cholesteryl ester-rich microemulsion (CERM), a smaller neo HDL that is apolipoprotein (apo) AI-poor, and lipid-free apo AI. SOF is active versus both human and mouse plasma HDL. In vivo injection of SOF into mice reduces plasma cholesterol ∼40% in 3 h while forming the same products observed in vitro, but at different ratios. Previous studies supported the hypothesis that labile apo AI is required for the SOF reaction vs HDL. Here we further tested that hypothesis by studies of SOF against HDL from apo AI-null mice. When injected into apo AI-null mice, SOF reduced plasma cholesterol ∼35% in 3 h. The reaction of SOF vs apo AI-null HDL in vitro produced a CERM and neo HDL, but no lipid-free apo. Moreover, according to the rate of CERM formation, the extent and rate of the SOF reaction versus apo AI-null mouse HDL were less than that against wild-type (WT) mouse HDL. Chaotropic perturbation studies using guanidine hydrochloride showed that apo AI-null HDL was more stable than WT HDL. Human apo AI added to apo AI-null HDL was quantitatively incorporated, giving reconstituted HDL. Both SOF and guanidine hydrochloride displaced apo AI from the reconstituted HDL. These results support the conclusion that apo AI-null HDL is more stable than WT HDL because it lacks apo AI, a labile protein that is readily displaced by physicochemical and biochemical perturbations. Thus, apo AI-null HDL is less SOF-reactive than WT HDL. The properties of apo AI-null HDL can be partially restored to those of WT HDL by the spontaneous incorporation of human apo AI. It remains to be determined what other HDL functions are affected by apo AI deletion. PMID:25790332

  5. The Effects of Ginger on Fasting Blood Sugar, Hemoglobin A1c, Apolipoprotein B, Apolipoprotein A-I and Malondialdehyde in Type 2 Diabetic Patients

    PubMed Central

    Khandouzi, Nafiseh; Shidfar, Farzad; Rajab, Asadollah; Rahideh, Tayebeh; Hosseini, Payam; Mir Taheri, Mohsen

    2015-01-01

    Diabetes mellitus is the most common endocrine disorder, causes many complications such as micro- and macro-vascular diseases. Anti-diabetic, hypolipidemic and anti-oxidative properties of ginger have been noticed in several researches. The present study was conducted to investigate the effects of ginger on fasting blood sugar, Hemoglobin A1c, apolipoprotein B, apolipoprotein A-I, and malondialdehyde in type 2 diabetic patients. In a randomized, double-blind, placebo-controlled, clinical trial, a total of 41 type 2 diabetic patients randomly were assigned to ginger or placebo groups (22 in ginger group and 19 in control group), received 2 g/day of ginger powder supplement or lactose as placebo for 12 weeks. The serum concentrations of fasting blood sugar, Hemoglobin A1c, apolipoprotein B, apolipoprotein A-I and malondialdehyde were analyzed before and after the intervention. Ginger supplementation significantly reduced the levels of fasting blood sugar, hemoglobin A1c, apolipoprotein B, apolipoprotein B/apolipoprotein A-I and malondialdehyde in ginger group in comparison to baseline, as well as control group, while it increased the level of apolipoprotein A-I (p<0.05). It seems that oral administration of ginger powder supplement can improves fasting blood sugar, hemoglobin A1c, apolipoprotein B, apolipoprotein A-I, apolipoprotein B/apolipoprotein A-I and malondialdehyde in type 2 diabetic patients. So it may have a role in alleviating the risk of some chronic complications of diabetes. PMID:25561919

  6. Apolipoprotein A-I mimetic peptide D-4F promotes human endothelial progenitor cell proliferation, migration, adhesion though eNOS/NO pathway.

    PubMed

    Zhang, Zhengang; Qun, Jianhua; Cao, Chunmei; Wang, Jun; Li, Wei; Wu, Yong; Du, Lin; Zhao, Pei; Gong, Kaizheng

    2012-04-01

    Circulating endothelial progenitor cells (EPCs) have a critical role in endothelial maintenance and repair. Apolipoprotein A-I mimetic peptide D-4F has been shown to posses anti-atherogenic properties via sequestration of oxidized phospholipids, induction of remodeling of high density lipoprotein and promotion of cholesterol efflux from macrophage-derived foam cells. In this study, we test the effects of D-4F on EPC biology. EPCs were isolated from the peripheral venous blood of healthy male volunteers and characterized by 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine-labeled acetylated LDL uptake and ulex europaeus agglutinin binding and flow cytometry. Cell proliferation, migration, adhesion, nitric oxide production and endothelial nitric oxide synthase (eNOS) expression in the absence and presence of D-4F or simvastatin (as a positive control), were assayed. We demonstrated that D-4F significantly enhanced EPC proliferation, migration and adhesion in a dose-dependent manner compared with vehicle. However, all of the favorable effects of D-4F on EPCs were dramatically attenuated by preincubation with NOS inhibitor L-NAME. Further, D-4F also increased nitric oxide production in culture supernatant and the levels of eNOS expression and phosphorylation. The stimulatory effects of D-4F (10 μg/ml) on EPC biology were comparable to 0.5 μM simvastatin. These results suggest that eNOS/NO pathway mediates the functional modulation of EPC biology in response to D-4F treatment and support the notion that the beneficial role of D-4F on EPCs may be one of the important components of its anti-atherogenic potential. PMID:21947883

  7. Identification of liver receptor homolog-1 as a novel regulator of apolipoprotein AI gene transcription.

    PubMed

    Delerive, Philippe; Galardi, Cristin M; Bisi, John E; Nicodeme, Edwige; Goodwin, Bryan

    2004-10-01

    The orphan nuclear receptor liver receptor homolog-1 (LRH-1) has been reported to play a role in bile acid biosynthesis and reverse cholesterol transport. In this study, we examined the role of LRH-1 in the regulation of the apolipoprotein AI (APOAI) gene. Using RNA interference and adenovirus-mediated overexpression, we show that LRH-1 directly regulates APOAI gene transcription. Transient transfection experiments and EMSAs revealed that LRH-1 directly regulates APOAI transcription by binding to an LRH-1 response element located in the proximal APOAI promoter region. Chromatin immunoprecipitation experiments revealed that LRH-1 binds to the human APO AI promoter in vivo. Finally, we show that the transcriptional repressor SHP (small heterodimer partner) suppressed APOAI gene expression by inhibiting LRH-1 transcriptional activity. Taken together, our results demonstrate that LRH-1 is a novel regulator of APOAI transcription and underscore the role of this receptor in cholesterol homeostasis. PMID:15218078

  8. Molecules that Mimic Apolipoprotein A-I: Potential Agents for Treating Atherosclerosis

    PubMed Central

    Leman, Luke J.; Maryanoff, Bruce E.; Ghadiri, M. Reza

    2013-01-01

    Certain amphipathic α-helical peptides can functionally mimic many of the properties of full-length apolipoproteins, thereby offering an approach to modulate high-density lipoprotein (HDL) for combating atherosclerosis. In this Perspective, we summarize the key findings and advances over the past 25 years in the development of peptides that mimic apolipoproteins, especially apolipoprotein A-I (apoA-I). This assemblage of information provides a reasonably clear picture of the state of the art in the apolipoprotein mimetic field, an appreciation of the potential for such agents in pharmacotherapy, and a sense of the opportunities for optimizing the functional properties of HDL. PMID:24168751

  9. Apolipoprotein A-I Q[-2]X causing isolated apolipoprotein A-I deficiency in a family with analphalipoproteinemia.

    PubMed Central

    Ng, D S; Leiter, L A; Vezina, C; Connelly, P W; Hegele, R A

    1994-01-01

    We report a Canadian kindred with a novel mutation in the apolipoprotein (apo) A-I gene causing analphalipoproteinemia. The 34-yr-old proband, product of a consanguineous marriage, had bilateral retinopathy, bilateral cataracts, spinocerebellar ataxia, and tendon xanthomata. High density lipoprotein cholesterol (HDL-C) was < 0.1 mM and apoA-I was undetectable. Genomic DNA sequencing of the proband's apoA-I gene identified a nonsense mutation at codon [-2], which we designate as Q[-2]X. This mutation causes a loss of endonuclease digestion sites for both BbvI and Fnu4HI. Genotyping identified four additional homozygotes, four heterozygotes, and two unaffected subjects among the first-degree relatives. Q[-2]X homozygosity causes a selective failure to produce any portion of mature apoA-I, resulting in very low plasma level of HDL. Heterozygosity results in approximately half-normal apoA-I and HDL. Gradient gel electrophoresis and differential electroimmunodiffusion assay revealed that the HDL particles of the homozygotes had peak Stokes diameter of 7.9 nm and contained apoA-II without apoA-I (Lp-AII). Heterozygotes had an additional fraction of HDL3-like particles. Two of the proband's affected sisters had documented premature coronary heart disease. This kindred, the third reported apoA-I gene mutation causing isolated complete apoA-I deficiency, appears to be at significantly increased risk for atherosclerosis. Images PMID:8282791

  10. Decreased serum apolipoprotein A-I concentrations in cows infected with Salmonella typhimurium.

    PubMed Central

    Oikawa, S; Katoh, N; Itoh, H; Miyamoto, T; Konno, M; Kajita, T

    1997-01-01

    Serum apolipoprotein A-I concentrations in cows infected with Salmonella Typhimurium were evaluated to assess its relevance in salmonellosis. Apolipoprotein A-I has been shown in rats to be secreted by the intestine as well as the liver. Clinical symptoms such as diarrhea revealed an outbreak of salmonellosis in 22 cows on a farm, and sera were obtained at 6 (acute phase), 16, 28 (convalescent period) and 42 d (postconvalescent period) after the outbreak. Apolipoprotein A-I concentrations (mean +/- SD, mg/mL), determined by ELISA, were 0.598 +/- 0.497 (day 6), 0.111 +/- 0.060 (day 16), 0.432 +/- 0.311 (day 28) and 0.727 +/- 0.516 (day 42). Compared with the concentration at day 42, those at 16 and 28 d were significantly (P < 0.01, P < 0.05) lower, but that at day 6 was not. The serum concentration of apolipoprotein B-100 (of liver origin in cattle) was unaltered during the course of salmonellosis. The concentration of apolipoprotein A-I was positively correlated with those of serum total cholesterol (r = 0.589, P < 0.01) and phospholipids (r = 0.590, P < 0.01). These results suggest that apolipoprotein A-I in cattle is in part of intestinal origin, and also that its decreased serum concentration in salmonellosis can be attributed to the reduced intestinal synthesis or secretion of this apolipoprotein. Moreover, as a potential carrier for dietary lipids such as cholesterol, determination of serum apolipoprotein A-I concentration is suggested to be useful when assessing the nutritional status of the affected cows. PMID:9242997

  11. Fructated apolipoprotein A-I exacerbates cellular senescence in human umbilical vein endothelial cells accompanied by impaired insulin secretion activity and embryo toxicity.

    PubMed

    Park, Ki-Hoon; Kim, Jae-Yong; Choi, Inho; Kim, Jae-Ryong; Won, Kyu Chang; Cho, Kyung-Hyun

    2016-08-01

    Glycation of apolipoproteins is a major feature of the production of dysfunctional high-density lipoprotein (HDL), which is associated with the incidence of several metabolic diseases such as coronary artery disease and diabetes. In this report, fructated apoA-I (fA-I) induced by fructose treatment showed a covalently multimerized band without cross-linking, and lysine residues were irreversibly modified to prevent crosslinking. Using pancreatic β-cells, insulin secretion was impaired by fA-I in the lipid-free and reconstituted HDL (rHDL) states, by up to 35%, and 40%, respectively, under hyperglycemic conditions (25 mmol/L glucose). Treatment of human umbilical vein endothelial cells (HUVECs) with fA-I and HDL from elderly patients caused a 1.8-fold and 1.5-fold increased cellular senescence, respectively, along with increased lysosomal enlargement. In the lipid-free and rHDL states, fA-I increased embryo death by 1.5-fold and 2.5-fold, respectively, along with the production of oxidized species. Furthermore, rHDL containing fA-I (fA-I-rHDL) showed a higher isoelectric point (pI, approximately 8.5), whereas rHDL containing nA-I (nA-I-rHDL) showed a narrow band range with lower pI (around 8.0) as well as a much smaller particle size than that of nA-I-rHDL. In conclusion, fructose-mediated apoA-I fructation resulted in the severe loss of several beneficial functions of apoA-I and HDL, including anti-senescence and insulin secretion activities, accompanied with increased susceptibility to protein degradation and structural modification. PMID:27487295

  12. Bioinformatic Analysis of Plasma Apolipoproteins A-I and A-II Revealed Unique Features of A-I/A-II HDL Particles in Human Plasma

    PubMed Central

    Kido, Toshimi; Kurata, Hideaki; Kondo, Kazuo; Itakura, Hiroshige; Okazaki, Mitsuyo; Urata, Takeyoshi; Yokoyama, Shinji

    2016-01-01

    Plasma concentration of apoA-I, apoA-II and apoA-II-unassociated apoA-I was analyzed in 314 Japanese subjects (177 males and 137 females), including one (male) homozygote and 37 (20 males and 17 females) heterozygotes of genetic CETP deficiency. ApoA-I unassociated with apoA-II markedly and linearly increased with HDL-cholesterol, while apoA-II increased only very slightly and the ratio of apoA-II-associated apoA-I to apoA-II stayed constant at 2 in molar ratio throughout the increase of HDL-cholesterol, among the wild type and heterozygous CETP deficiency. Thus, overall HDL concentration almost exclusively depends on HDL with apoA-I without apoA-II (LpAI) while concentration of HDL containing apoA-I and apoA-II (LpAI:AII) is constant having a fixed molar ratio of 2 : 1 regardless of total HDL and apoA-I concentration. Distribution of apoA-I between LpAI and LpAI:AII is consistent with a model of statistical partitioning regardless of sex and CETP genotype. The analysis also indicated that LpA-I accommodates on average 4 apoA-I molecules and has a clearance rate indistinguishable from LpAI:AII. Independent evidence indicated LpAI:A-II has a diameter 20% smaller than LpAI, consistent with a model having two apoA-I and one apoA-II. The functional contribution of these particles is to be investigated. PMID:27526664

  13. Bioinformatic Analysis of Plasma Apolipoproteins A-I and A-II Revealed Unique Features of A-I/A-II HDL Particles in Human Plasma.

    PubMed

    Kido, Toshimi; Kurata, Hideaki; Kondo, Kazuo; Itakura, Hiroshige; Okazaki, Mitsuyo; Urata, Takeyoshi; Yokoyama, Shinji

    2016-01-01

    Plasma concentration of apoA-I, apoA-II and apoA-II-unassociated apoA-I was analyzed in 314 Japanese subjects (177 males and 137 females), including one (male) homozygote and 37 (20 males and 17 females) heterozygotes of genetic CETP deficiency. ApoA-I unassociated with apoA-II markedly and linearly increased with HDL-cholesterol, while apoA-II increased only very slightly and the ratio of apoA-II-associated apoA-I to apoA-II stayed constant at 2 in molar ratio throughout the increase of HDL-cholesterol, among the wild type and heterozygous CETP deficiency. Thus, overall HDL concentration almost exclusively depends on HDL with apoA-I without apoA-II (LpAI) while concentration of HDL containing apoA-I and apoA-II (LpAI:AII) is constant having a fixed molar ratio of 2 : 1 regardless of total HDL and apoA-I concentration. Distribution of apoA-I between LpAI and LpAI:AII is consistent with a model of statistical partitioning regardless of sex and CETP genotype. The analysis also indicated that LpA-I accommodates on average 4 apoA-I molecules and has a clearance rate indistinguishable from LpAI:AII. Independent evidence indicated LpAI:A-II has a diameter 20% smaller than LpAI, consistent with a model having two apoA-I and one apoA-II. The functional contribution of these particles is to be investigated. PMID:27526664

  14. Apolipoprotein AI levels are increased in part as a consequence of reduced catabolism in nephrotic rats.

    PubMed

    Kaysen, G A; Hoye, E; Jones, H

    1995-03-01

    Apolipoprotein AI (apo AI) synthesis, measured as the turnover of 125I-labeled apo AI-labeled high-density lipoprotein (HDL), was increased significantly in rats with Heymann nephritis (HN) vs. control Sprague-Dawley (SD) rats. However, fractional apo AI catabolic rate was also significantly less in HN vs. SD. We used 125I-apo AI tyramine cellobiose HDL, a marker retained at the catabolic site, to establish where apo AI catabolism decreased in six HN rats, seven rats with adriamycin (Adria)-induced nephrosis, and six control SD. Total renal apo AI catabolism, plus urinary losses, were the same in all three groups, despite significant urinary apo AI in HN and Adria rats. Apo AI catabolism was reduced in skin in both nephrotic groups, accounting for approximately 44% of reduced in apo AI catabolism. Thus a significant fraction of apo AI is catabolized in skin of normal male rats. Reduced apo AI catabolism in skin contributes to increased plasma levels in nephrotic rats. PMID:7900854

  15. Characterization of high density lipoprotein particles in familial apolipoprotein A-I deficiency

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our aim was to characterize HDL subspecies and fat-soluble vitamin levels in a kindred with familial apolipoprotein A-I (apoA-I) deficiency. Sequencing of the APOA1 gene revealed a nonsense mutation at codon 22, Q[22]X, with two documented homozygotes, eight heterozygotes, and two normal subjects in...

  16. Apolipoprotein A-I localization and dipalmitoylphosphatidylcholine dynamics in reconstituted high density lipoproteins.

    PubMed

    Dergunov, A D; Dobretsov, G E

    2000-02-01

    The structure and molecular dynamics of recombinant high density lipoproteins (rHDL) were studied by non-radiative energy transfer (NRET), fluorescence anisotropy and intensity measurements. The rHDL particles contained human plasma apolipoprotein (apo) A-I and dipalmitoylphosphatidylcholine (DPPC). Fluorescent cis- and trans-parinaric acids were used both as probes of molecular motion in the particle lipid phase and as acceptors in the Forster's energy transfer from apo A-I tryptophan residues to determine particle dimensions, apolipoprotein localization and lipid dynamics. The probes are sensitive to thermal wobbling (macromobility) and conformational deformations (micromobility) of phospholipid acyl chains. The experimental data fitted to various models of the particle structure are compatible with the following: (a) at T < Tt the particles appeared as lens-like discs with a radius of the lipid phase of 5 nm and a mean thickness of 4 nm, the value being more by 20% in the particle centre, the alpha-helices of about 1 nm thickness were located around the edge of the lipid core. Compared to liposomes, both macro- and micromobility of DPPC molecules in rHDL were more rapid due to a significant disorder of the boundary lipid molecules close to the apo A-I molecule. This disorder led to the increase of the specific surface area per one lipid molecule, S(o). The lipid phase can be divided into three regions: (i) zone I of the most tightly packed lipid (0-1.7 nm from the disc axis) with a S(o) value small as 0.5 nm2; (ii) intermediate zone II (from 1.7 to 4.0 nm); and (iii) boundary lipid zone III (4-5 nm) of significantly disordered lipid with a S(o) value large as 0.65 nm2. (b) at T> Tt the S(o) heterogeneity disappeared, the radius of the lipid phase did not increase significantly, not exceeding 5.2-5.4 nm, but protein-induced immobilization of lipid molecules which affected about half or more of the total lipid, became remarkable. The overall effect was the

  17. The Effect of Aerobic Exercise on Total Cholesterol, High-Density Lipoprotein, Apolipoprotein B, Apolipoprotein A-I, and Percent Body Fat in Adolescent Females.

    ERIC Educational Resources Information Center

    Lungo, Diane; And Others

    The effect of aerobic exercise on total cholesterol (TC), high-density lipoprotein (HDL), apolipoprotein B (Apo B), apolioprotein A-I (Apo A-I), and percent body fat in adolescent females was studied. The control subjects (n=86) were volunteers who had completed a physical education class at least six months prior to the commencement of the study,…

  18. Regulation of the promoter of rat apolipoprotein A-I gene in cultured cells

    SciTech Connect

    Chao, Y.; Pan, T.; Wu, T.; Hao, Q.; Yamin, T.; Kroon, P.A.

    1987-05-01

    In order to study the regulation of the promoter of apolipoprotein (apo) A-I gene, they joined the 5' end of rat apo A-I gene (1.9 Kb) to the coding region of bacterial chloramphenicol acetyltransferase (CAT) gene. The chimeric gene produced high levels of CAT activity in both mouse L cells and Hep G2 cells in transient expression assays. Ethanol increased the levels of rat apo A-I promoter activity in both cells. However, dexamethasone increased rat apo A-I promoter activity only in Hep G2 cells. Similar results were obtained in stable expression cell lines. Nucleotide deletion experiments showed DNA sequences between -149 and -469 base pairs upstream from the rat apo A-I transcription site are required for the high level of expression and that the regulatory sequences are located further upstream. These data demonstrated that the 5' end of rat apo A-I gene contains sequences which are responsible for the regulation of apo A-I expression by ethanol and dexamethasone and that the expression and regulation of rat apo A-I promoter are cell specific.

  19. Repression by ARP-1 sensitizes apolipoprotein AI gene responsiveness to RXR alpha and retinoic acid.

    PubMed Central

    Widom, R L; Rhee, M; Karathanasis, S K

    1992-01-01

    The gene coding for apolipoprotein AI (apoAI), a lipid binding protein involved in the transport of cholesterol and other lipids in the plasma, is expressed in mammals predominantly in the liver and the intestine. Liver-specific expression is controlled by synergistic interactions between transcription factors bound to three separate sites, sites A (-214 to -192), B (-169 to -146), and C (-134 to -119), within a powerful liver-specific enhancer located between nucleotides -222 and -110 upstream of the apoAI gene transcription start site (+1). Previous studies in our laboratory have shown that ARP-1, a member of the nuclear receptor superfamily whose ligand is unknown (orphan receptor), binds to site A and represses transcription of the apoAI gene in liver cells. In a more recent series of experiments, we found that site A is a retinoic acid (RA) response element that responds preferentially to the recently identified RA-responsive receptor RXR alpha over the previously characterized RA receptors RAR alpha and RAR beta. In this study we investigated the combined effects of ARP-1 and RXR alpha on apoAI gene expression in liver cells. Transient transfection assays showed that site A is necessary and sufficient for RXR alpha-mediated transactivation of the apoAI gene basal promoter in human hepatoma HepG2 cells in the presence of RA and that this transactivation is abolished by increasing amounts of cotransfected ARP-1. Electrophoretic mobility shift assays and subsequent Scatchard analysis of the data revealed that ARP-1 and RXR alpha bind to site A with similar affinities. These assays also revealed that ARP-1 and RXR alpha bind to site A as heterodimers with an affinity approximately 10 times greater than that of either ARP-1 or RXR alpha alone. Further transfection assays in HepG2 cells, using as a reporter a construct containing the apoAI gene basal promoter and its upstream regulatory elements (including site A) in their natural context, revealed that RXR alpha

  20. Apolipoprotein A-I mutant proteins having cysteine substitutions and polynucleotides encoding same

    DOEpatents

    Oda, Michael N.; Forte, Trudy M.

    2007-05-29

    Functional Apolipoprotein A-I mutant proteins, having one or more cysteine substitutions and polynucleotides encoding same, can be used to modulate paraoxonase's arylesterase activity. These ApoA-I mutant proteins can be used as therapeutic agents to combat cardiovascular disease, atherosclerosis, acute phase response and other inflammatory related diseases. The invention also includes modifications and optimizations of the ApoA-I nucleotide sequence for purposes of increasing protein expression and optimization.

  1. Apolipoprotein AI could be a significant determinant of epithelial integrity in rainbow trout gill cell cultures: a study in functional proteomics.

    PubMed

    Smith, Richard W; Wood, Chris M; Cash, Phil; Diao, Linda; Pärt, Peter

    2005-05-20

    The freshwater fish gill forms a barrier against an external hypotonic environment. By culturing rainbow trout gill cells on permeable supports, as intact epithelia, this study investigates barrier property mechanisms. Under symmetrical conditions the apical and basolateral epithelial surfaces contact cell culture media. Replacing apical media with water, to generate asymmetrical conditions (i.e. the situation encountered by the freshwater gill), rapidly increases transepithelial resistance (TER). Proteomic analysis revealed that this is associated with enhanced expression of pre-apolipoprotein AI (pre-apoAI). To test the physiological relevance, gill cells were treated with a dose of 50 microg ml(-1) human apolipoprotein (apoAI). This was found to elevate TER in those epithelia which displayed a lower TER prior to apoAI treatment. These results demonstrate the action of apoAI and provide evidence that the rainbow trout gill may be a site of apoAI synthesis. TER does not differentiate between the trans-cellular (via the cell membrane) and para-cellular (via intercellular tight junctions) pathways. However, despite the apoAI-induced changes in TER, para-cellular permeability (measured by polyethylene glycol efflux) remained unaltered suggesting apoAI specifically reduces trans-cellular permeability. This investigation combines proteomics with functional measurements to show how a proteome change may be associated with freshwater gill function. PMID:15848139

  2. Iowa Mutant Apolipoprotein A-I (ApoA-IIowa) Fibrils Target Lysosomes.

    PubMed

    Kameyama, Hirokazu; Nakajima, Hiroyuki; Nishitsuji, Kazuchika; Mikawa, Shiho; Uchimura, Kenji; Kobayashi, Norihiro; Okuhira, Keiichiro; Saito, Hiroyuki; Sakashita, Naomi

    2016-01-01

    The single amino acid mutation G26R in human apolipoprotein A-I (apoA-IIowa) is the first mutation that was associated with familial AApoA1 amyloidosis. The N-terminal fragments (amino acid residues 1-83) of apoA-I containing this mutation deposit as amyloid fibrils in patients' tissues and organs, but the mechanisms of cellular degradation and cytotoxicity have not yet been clarified. In this study, we demonstrated degradation of apoA-IIowa fibrils via the autophagy-lysosomal pathway in human embryonic kidney 293 cells. ApoA-IIowa fibrils induced an increase in lysosomal pH and the cytosolic release of the toxic lysosomal protease cathepsin B. The mitochondrial dysfunction caused by apoA-IIowa fibrils depended on cathepsin B and was ameliorated by increasing the degradation of apoA-IIowa fibrils. Thus, although apoA-IIowa fibril transport to lysosomes and fibril degradation in lysosomes may have occurred, the presence of an excess number of apoA-IIowa fibrils, more than the lysosomes could degrade, may be detrimental to cells. Our results thus provide evidence that the target of apoA-IIowa fibrils is lysosomes, and we thereby gained a novel insight into the mechanism of AApoA1 amyloidosis. PMID:27464946

  3. Iowa Mutant Apolipoprotein A-I (ApoA-IIowa) Fibrils Target Lysosomes

    PubMed Central

    Kameyama, Hirokazu; Nakajima, Hiroyuki; Nishitsuji, Kazuchika; Mikawa, Shiho; Uchimura, Kenji; Kobayashi, Norihiro; Okuhira, Keiichiro; Saito, Hiroyuki; Sakashita, Naomi

    2016-01-01

    The single amino acid mutation G26R in human apolipoprotein A-I (apoA-IIowa) is the first mutation that was associated with familial AApoA1 amyloidosis. The N-terminal fragments (amino acid residues 1–83) of apoA-I containing this mutation deposit as amyloid fibrils in patients’ tissues and organs, but the mechanisms of cellular degradation and cytotoxicity have not yet been clarified. In this study, we demonstrated degradation of apoA-IIowa fibrils via the autophagy-lysosomal pathway in human embryonic kidney 293 cells. ApoA-IIowa fibrils induced an increase in lysosomal pH and the cytosolic release of the toxic lysosomal protease cathepsin B. The mitochondrial dysfunction caused by apoA-IIowa fibrils depended on cathepsin B and was ameliorated by increasing the degradation of apoA-IIowa fibrils. Thus, although apoA-IIowa fibril transport to lysosomes and fibril degradation in lysosomes may have occurred, the presence of an excess number of apoA-IIowa fibrils, more than the lysosomes could degrade, may be detrimental to cells. Our results thus provide evidence that the target of apoA-IIowa fibrils is lysosomes, and we thereby gained a novel insight into the mechanism of AApoA1 amyloidosis. PMID:27464946

  4. Apolipoprotein A-I metabolism in cynomolgus monkey. Identification and characterization of beta-migrating pools

    SciTech Connect

    Melchior, G.W.; Castle, C.K.

    1989-07-01

    Fresh plasma from control (C) and hypercholesterolemic (HC) cynomolgus monkeys was analyzed by agarose electrophoresis-immunoblotting with antibody to cynomolgus monkey apolipoprotein (apo) A-I. Two bands were evident on the autoradiogram: an alpha-migrating band (high density lipoprotein) and a beta-migrating band that comigrated exactly with cynomolgus monkey low density lipoprotein (LDL). The presence of beta-migrating apo A-I in the plasma of these monkeys was confirmed by Geon-Pevikon preparative electrophoresis, crossed immunoelectrophoresis, and isotope dilution studies in which radiolabeled apo A-I was found to equilibrate also with alpha- and beta-migrating pools of apo A-I in the plasma. Subfractionation of C and HC plasma by agarose column chromatography (Bio-Gel A-0.5M and A-15M) followed by agarose electrophoresis-immunoblotting indicated that the beta-migrating apo A-I in C was relatively homogeneous and eluted with proteins of Mr approximately 50 kD (apo A-I(50 kD)), whereas two beta-migrating fractions were identified in HC, one that eluted with the 50-kD proteins, and the other that eluted in the LDL Mr range (apo A-I(LDL)). The apo A-I(LDL) was precipitated by antibody to cynomolgus monkey apo B. The apo A-I(50 kD) accounted for 5 +/- 1% (mean +/- SD) of the plasma apo A-I in C plasma, and 15 +/- 7% in HC plasma. No apo A-I(LDL) was detected in C plasma, but that fraction accounted for 9 +/- 7% of the apo A-I in HC plasma. These data establish the presence of multiple pools of apo A-I in the cynomolgus monkey, which must be taken into consideration in any comprehensive model of apo A-I metabolism in this species.

  5. A model of lipid-free Apolipoprotein A-I revealed by iterative molecular dynamics simulation

    DOE PAGESBeta

    Zhang, Xing; Lei, Dongsheng; Zhang, Lei; Rames, Matthew; Zhang, Shengli

    2015-03-20

    Apolipoprotein A-I (apo A-I), the major protein component of high-density lipoprotein, has been proven inversely correlated to cardiovascular risk in past decades. The lipid-free state of apo A-I is the initial stage which binds to lipids forming high-density lipoprotein. Molecular models of lipid-free apo A-I have been reported by methods like X-ray crystallography and chemical cross-linking/mass spectrometry (CCL/MS). Through structural analysis we found that those current models had limited consistency with other experimental results, such as those from hydrogen exchange with mass spectrometry. Through molecular dynamics simulations, we also found those models could not reach a stable equilibrium state. Therefore,more » by integrating various experimental results, we proposed a new structural model for lipidfree apo A-I, which contains a bundled four-helix N-terminal domain (1–192) that forms a variable hydrophobic groove and a mobile short hairpin C-terminal domain (193–243). This model exhibits an equilibrium state through molecular dynamics simulation and is consistent with most of the experimental results known from CCL/MS on lysine pairs, fluorescence resonance energy transfer and hydrogen exchange. This solution-state lipid-free apo A-I model may elucidate the possible conformational transitions of apo A-I binding with lipids in high-density lipoprotein formation.« less

  6. A model of lipid-free Apolipoprotein A-I revealed by iterative molecular dynamics simulation

    SciTech Connect

    Zhang, Xing; Lei, Dongsheng; Zhang, Lei; Rames, Matthew; Zhang, Shengli

    2015-03-20

    Apolipoprotein A-I (apo A-I), the major protein component of high-density lipoprotein, has been proven inversely correlated to cardiovascular risk in past decades. The lipid-free state of apo A-I is the initial stage which binds to lipids forming high-density lipoprotein. Molecular models of lipid-free apo A-I have been reported by methods like X-ray crystallography and chemical cross-linking/mass spectrometry (CCL/MS). Through structural analysis we found that those current models had limited consistency with other experimental results, such as those from hydrogen exchange with mass spectrometry. Through molecular dynamics simulations, we also found those models could not reach a stable equilibrium state. Therefore, by integrating various experimental results, we proposed a new structural model for lipidfree apo A-I, which contains a bundled four-helix N-terminal domain (1–192) that forms a variable hydrophobic groove and a mobile short hairpin C-terminal domain (193–243). This model exhibits an equilibrium state through molecular dynamics simulation and is consistent with most of the experimental results known from CCL/MS on lysine pairs, fluorescence resonance energy transfer and hydrogen exchange. This solution-state lipid-free apo A-I model may elucidate the possible conformational transitions of apo A-I binding with lipids in high-density lipoprotein formation.

  7. A Model of Lipid-Free Apolipoprotein A-I Revealed by Iterative Molecular Dynamics Simulation

    PubMed Central

    Zhang, Xing; Lei, Dongsheng; Zhang, Lei; Rames, Matthew; Zhang, Shengli

    2015-01-01

    Apolipoprotein A-I (apo A-I), the major protein component of high-density lipoprotein, has been proven inversely correlated to cardiovascular risk in past decades. The lipid-free state of apo A-I is the initial stage which binds to lipids forming high-density lipoprotein. Molecular models of lipid-free apo A-I have been reported by methods like X-ray crystallography and chemical cross-linking/mass spectrometry (CCL/MS). Through structural analysis we found that those current models had limited consistency with other experimental results, such as those from hydrogen exchange with mass spectrometry. Through molecular dynamics simulations, we also found those models could not reach a stable equilibrium state. Therefore, by integrating various experimental results, we proposed a new structural model for lipid-free apo A-I, which contains a bundled four-helix N-terminal domain (1–192) that forms a variable hydrophobic groove and a mobile short hairpin C-terminal domain (193–243). This model exhibits an equilibrium state through molecular dynamics simulation and is consistent with most of the experimental results known from CCL/MS on lysine pairs, fluorescence resonance energy transfer and hydrogen exchange. This solution-state lipid-free apo A-I model may elucidate the possible conformational transitions of apo A-I binding with lipids in high-density lipoprotein formation. PMID:25793886

  8. Bioenergetic programming of macrophages by the apolipoprotein A-I mimetic peptide 4F.

    PubMed

    Datta, Geeta; Kramer, Philip A; Johnson, Michelle S; Sawada, Hirotaka; Smythies, Lesley E; Crossman, David K; Chacko, Balu; Ballinger, Scott W; Westbrook, David G; Mayakonda, Palgunachari; Anantharamaiah, G M; Darley-Usmar, Victor M; White, C Roger

    2015-05-01

    The apoA-I (apolipoprotein A-I) mimetic peptide 4F favours the differentiation of human monocytes to an alternatively activated M2 phenotype. The goal of the present study was to test whether the 4F-mediated differentiation of MDMs (monocyte-derived macrophages) requires the induction of an oxidative metabolic programme. 4F treatment induced several genes in MDMs that play an important role in lipid metabolism, including PPARγ (peroxisome-proliferator-activated receptor γ) and CD36. Addition of 4F was associated with a significant increase in FA (fatty acid) uptake and oxidation compared with vehicle treatment. Mitochondrial respiration was assessed by measurement of the OCR (oxygen-consumption rate). 4F increased basal and ATP-linked OCR as well as maximal uncoupled mitochondrial respiration. These changes were associated with a significant increase in ΔΨm (mitochondrial membrane potential). The increase in metabolic activity in 4F-treated MDMs was attenuated by etomoxir, an inhibitor of mitochondrial FA uptake. Finally, addition of the PPARγ antagonist T0070907 to 4F-treated MDMs reduced the expression of CD163 and CD36, cell-surface markers for M2 macrophages, and reduced basal and ATP-linked OCR. These results support our hypothesis that the 4F-mediated differentiation of MDMs to an anti-inflammatory phenotype is due, in part, to an increase in FA uptake and mitochondrial oxidative metabolism. PMID:25742174

  9. Amyloidogenic Mutations in Human Apolipoprotein A-I are not Necessarily Destabilizing: A Common Mechanism of ApoA-I Misfolding in Familial Amyloidosis and Atherosclerosis

    PubMed Central

    Das, Madhurima; Mei, Xiaohu; Jayaraman, Shobini; Atkinson, David; Gursky, Olga

    2014-01-01

    High-density lipoproteins (HDLs) and their major protein, apoA-I, remove excess cellular cholesterol and protect against atherosclerosis. However, in acquired amyloidosis, non-variant full-length apoA-I deposits as fibrils in atherosclerotic plaques; in familial amyloidosis, N-terminal fragments of variant apoA-I deposit in vital organs damaging them. Recently, we used the crystal structure of Δ(185-243)apoA-I to propose that amyloidogenic mutations destabilize apoA-I and increase solvent exposure of the extended strand 44-55 that initiates β-aggregation. Here we test this hypothesis by exploring naturally occurring human amyloidogenic mutations, W50R and G26R, within or close to this strand. The mutations caused small changes in the protein’s α-helical content, stability, proteolytic pattern, and protein-lipid interactions. These changes alone were unlikely to account for amyloidosis, suggesting the importance of other factors. Sequence analysis predicted several amyloid-prone segments that can initiate apoA-I misfolding. Aggregation studies using N-terminal fragments experimentally verified this prediction. Three predicted N-terminal amyloid-prone segments, mapped on the crystal structure, formed an α-helical cluster. Structural analysis indicates that amyloidogenic mutations or Met86 oxidation perturb native packing in this cluster. Together, the results suggest that structural perturbations in the amyloid-prone segments trigger α-helix-to-β-sheet conversion in the N-terminal ~75 residues forming the amyloid core. Polypeptide outside this core can be proteolysed to form 9-11 kDa N-terminal fragments found in familial amyloidosis. Our results imply that apoA-I misfolding in familial and acquired amyloidosis follows a similar mechanism that does not require significant structural destabilization or proteolysis. This novel mechanism suggests potential therapeutic interventions for apoA-I amyloidosis. PMID:24702826

  10. Importance of Apolipoprotein A-I in Multiple Sclerosis

    PubMed Central

    Gardner, Lidia A.; Levin, Michael C.

    2015-01-01

    Jean-Martin Charcot has first described multiple sclerosis (MS) as a disease of the central nervous system (CNS) over a century ago. MS remains incurable today, and treatment options are limited to disease modifying drugs. Over the years, significant advances in understanding disease pathology have been made in autoimmune and neurodegenerative components. Despite the fact that brain is the most lipid rich organ in human body, the importance of lipid metabolism has not been extensively studied in this disorder. In MS, the CNS is under attack by a person’s own immune system. Autoantigens and autoantibodies are known to cause devastation of myelin through up regulation of T-cells and cytokines, which penetrate through the blood–brain barrier to cause inflammation and myelin destruction. The anti-inflammatory role of high-density lipoproteins (HDLs) has been implicated in a plethora of biological processes: vasodilation, immunity to infection, oxidation, inflammation, and apoptosis. However, it is not known what role HDL plays in neurological function and myelin repair in MS. Understanding of lipid metabolism in the CNS and in the periphery might unveil new therapeutic targets and explain the partial success of some existing MS therapies. PMID:26635608

  11. Importance of Apolipoprotein A-I in Multiple Sclerosis.

    PubMed

    Gardner, Lidia A; Levin, Michael C

    2015-01-01

    Jean-Martin Charcot has first described multiple sclerosis (MS) as a disease of the central nervous system (CNS) over a century ago. MS remains incurable today, and treatment options are limited to disease modifying drugs. Over the years, significant advances in understanding disease pathology have been made in autoimmune and neurodegenerative components. Despite the fact that brain is the most lipid rich organ in human body, the importance of lipid metabolism has not been extensively studied in this disorder. In MS, the CNS is under attack by a person's own immune system. Autoantigens and autoantibodies are known to cause devastation of myelin through up regulation of T-cells and cytokines, which penetrate through the blood-brain barrier to cause inflammation and myelin destruction. The anti-inflammatory role of high-density lipoproteins (HDLs) has been implicated in a plethora of biological processes: vasodilation, immunity to infection, oxidation, inflammation, and apoptosis. However, it is not known what role HDL plays in neurological function and myelin repair in MS. Understanding of lipid metabolism in the CNS and in the periphery might unveil new therapeutic targets and explain the partial success of some existing MS therapies. PMID:26635608

  12. Apolipoprotein A-I inhibits experimental colitis and colitis-propelled carcinogenesis.

    PubMed

    Gkouskou, K K; Ioannou, M; Pavlopoulos, G A; Georgila, K; Siganou, A; Nikolaidis, G; Kanellis, D C; Moore, S; Papadakis, K A; Kardassis, D; Iliopoulos, I; McDyer, F A; Drakos, E; Eliopoulos, A G

    2016-05-12

    In both humans with long-standing ulcerative colitis and mouse models of colitis-associated carcinogenesis (CAC), tumors develop predominantly in the distal part of the large intestine but the biological basis of this intriguing pathology remains unknown. Herein we report intrinsic differences in gene expression between proximal and distal colon in the mouse, which are augmented during dextran sodium sulfate (DSS)/azoxymethane (AOM)-induced CAC. Functional enrichment of differentially expressed genes identified discrete biological pathways operating in proximal vs distal intestine and revealed a cluster of genes involved in lipid metabolism to be associated with the disease-resistant proximal colon. Guided by this finding, we have further interrogated the expression and function of one of these genes, apolipoprotein A-I (ApoA-I), a major component of high-density lipoprotein. We show that ApoA-I is expressed at higher levels in the proximal compared with the distal part of the colon and its ablation in mice results in exaggerated DSS-induced colitis and disruption of epithelial architecture in larger areas of the large intestine. Conversely, treatment with an ApoA-I mimetic peptide ameliorated the phenotypic, histopathological and inflammatory manifestations of the disease. Genetic interference with ApoA-I levels in vivo impacted on the number, size and distribution of AOM/DSS-induced colon tumors. Mechanistically, ApoA-I was found to modulate signal transducer and activator of transcription 3 (STAT3) and nuclear factor-κB activation in response to the bacterial product lipopolysaccharide with concomitant impairment in the production of the pathogenic cytokine interleukin-6. Collectively, these data demonstrate a novel protective role for ApoA-I in colitis and CAC and unravel an unprecedented link between lipid metabolic processes and intestinal pathologies. PMID:26279300

  13. Leptospiral LruA is required for virulence and modulates an interaction with mammalian apolipoprotein AI.

    PubMed

    Zhang, Kunkun; Murray, Gerald L; Seemann, Torsten; Srikram, Amporn; Bartpho, Thanatchaporn; Sermswan, Rasana W; Adler, Ben; Hoke, David E

    2013-10-01

    Leptospirosis is a worldwide zoonosis caused by spirochetes of the genus Leptospira. While understanding of pathogenesis remains limited, the development of mutagenesis in Leptospira has provided a powerful tool for identifying novel virulence factors. LruA is a lipoprotein that has been implicated in leptospiral uveitis as a target of the immune response. In this study, two lruA mutants, M754 and M765, generated by transposon mutagenesis from Leptospira interrogans serovar Manilae, were characterized. In M754, the transposon inserted in the middle of lruA, resulting in no detectable expression of LruA. In M765, the transposon inserted toward the 3' end of the gene, resulting in expression of a truncated protein. LruA was demonstrated to be on the cell surface in M765 and the wild type (WT). M754, but not M765, was attenuated in a hamster model of acute infection. A search for differential binding to human serum proteins identified a serum protein of around 30 kDa bound to the wild type and the LruA deletion mutant (M754), but not to the LruA truncation mutant (M765). Two-dimensional separation of proteins from leptospiral cells incubated with guinea pig serum identified the 28-kDa apolipoprotein A-I (ApoA-I) as a major mammalian serum protein that binds Leptospira in vitro. Interestingly, M754 (with no detectable LruA) bound more ApoA-I than did the LruA-expressing strains Manilae wild type and M765. Our data thus identify LruA as a surface-exposed leptospiral virulence factor that contributes to leptospiral pathogenesis, possibly by modulating cellular interactions with serum protein ApoA-I. PMID:23918777

  14. Methionine oxidation induces amyloid fibril formation by full-length apolipoprotein A-I

    PubMed Central

    Wong, Yuan Qi; Binger, Katrina J.; Howlett, Geoffrey J.; Griffin, Michael D. W.

    2010-01-01

    Apolipoprotein A-I (apoA-I) is the major protein component of HDL, where it plays an important role in cholesterol transport. The deposition of apoA-I derived amyloid is associated with various hereditary systemic amyloidoses and atherosclerosis; however, very little is known about the mechanism of apoA-I amyloid formation. Methionine residues in apoA-I are oxidized via several mechanisms in vivo to form methionine sulfoxide (MetO), and significant levels of methionine oxidized apoA-I (MetO-apoA-I) are present in normal human serum. We investigated the effect of methionine oxidation on the structure, stability, and aggregation of full-length, lipid-free apoA-I. Circular dichrosim spectroscopy showed that oxidation of all three methionine residues in apoA-I caused partial unfolding of the protein and decreased its thermal stability, reducing the melting temperature (Tm) from 58.7 °C for native apoA-I to 48.2 °C for MetO-apoA-I. Analytical ultracentrifugation revealed that methionine oxidation inhibited the native self association of apoA-I to form dimers and tetramers. Incubation of MetO-apoA-I for extended periods resulted in aggregation of the protein, and these aggregates bound Thioflavin T and Congo Red. Inspection of the aggregates by electron microscopy revealed fibrillar structures with a ribbon-like morphology, widths of approximately 11 nm, and lengths of up to several microns. X-ray fibre diffraction studies of the fibrils revealed a diffraction pattern with orthogonal peaks at spacings of 4.64 Å and 9.92 Å, indicating a cross-β amyloid structure. This systematic study of fibril formation by full-length apoA-I represents the first demonstration that methionine oxidation can induce amyloid fibril formation. PMID:20133843

  15. Oxidation of high density lipoproteins. II. Evidence for direct reduction of lipid hydroperoxides by methionine residues of apolipoproteins AI and AII.

    PubMed

    Garner, B; Waldeck, A R; Witting, P K; Rye, K A; Stocker, R

    1998-03-13

    Human high density lipoproteins (HDL) can reduce cholesteryl ester hydroperoxides to the corresponding hydroxides (Sattler W., Christison J. K., and Stocker, R. (1995) Free Radical Biol. & Med. 18, 421-429). Here we demonstrate that this reducing activity extended to hydroperoxides of phosphatidylcholine, was similar in HDL2 and HDL3, was independent of arylesterase and lecithin:cholesteryl acyltransferase activity, was unaffected by sulfhydryl reagents, and was expressed by reconstituted particles containing apoAI or apoAII only, as well as isolated human apoAI. Concomitant with the reduction of lipid hydroperoxides specific oxidized forms of apoAI and apoAII formed in blood-derived and reconstituted HDL. Similarly, specific oxidized forms of apoAI accumulated upon treatment of isolated apoAI with authentic cholesteryl linoleate hydroperoxide. These specific oxidized forms of apoAI and apoAII have been shown previously to contain Met sulfoxide (Met(O)) at Met residues and are also formed when HDL is exposed to Cu2+ or soybean lipoxygenase. Lipid hydroperoxide reduction and the associated formation of specific oxidized forms of apoAI and apoAII were inhibited by solubilizing HDL with SDS or by pretreatment of HDL with chloramine T. The inhibitory effect of chloramine T was dose-dependent and accompanied by the conversion of specific Met residues of apoAI and apoAII into Met(O). Canine HDL, which contains apoAI as the predominant apolipoprotein and which lacks the oxidation-sensitive Met residues Met112 and Met148, showed much weaker lipid hydroperoxide reducing activity and lower extents of formation of oxidized forms of apoAI than human HDL. We conclude that the oxidation of specific Met residues of apoAI and apoAII to Met(O) plays a significant role in the 2-electron reduction of hydroperoxides of cholesteryl esters and phosphatidylcholine associated with human HDL. PMID:9497326

  16. [Influence of isoniazid complex with A-I apolipoprotein on activity of lysosomal enzymes in mice with tuberculous inflammation model].

    PubMed

    Sumenkova, D V; Poliakov, L M; Panin, L E

    2012-01-01

    It is established that isoniazid (isonicotinic acid hydrazide) can interact with A-I apolipoprotein to form a complex, which can be considered as the transport form of the preparation. The use of this complex for the treatment of mice with BCG-induced tuberculous inflammation led to an increase in the free activities of acid phosphatase and cathepsin D in the liver, which was decreased under the action of mycobacteria and the free form of isoniazid. The isoniazid complex with A-I apolipoprotein exhibited more expressed anti-inflammatory effect (estimated by the activity of chitotriosidase in blood serum) as compared to the free drug. PMID:23323330

  17. Heterogeneous expression of apolipoprotein-E by human macrophages

    PubMed Central

    Tedla, Nicodemus; Glaros, Elias N; Brunk, Ulf T; Jessup, Wendy; Garner, Brett

    2004-01-01

    Apolipoprotein-E (apoE) is expressed at high levels by macrophages. In addition to its role in lipid transport, macrophage-derived apoE plays an important role in immunoregulation. Previous studies have identified macrophage subpopulations that differ substantially in their ability to synthesize specific cytokines and enzymes, however, potential heterogeneous macrophage apoE expression has not been studied. Here we examined apoE expression in human THP-1 macrophages and monocyte-derived macrophages (MDM). Using immunocytochemistry and flow cytometry methods we reveal a striking heterogeneity in macrophage apoE expression in both cell types. In phorbol-ester-differentiated THP-1 macrophages, 5% of the cells over-expressed apoE at levels more than 50-fold higher than the rest of the population. ApoE over-expressing THP-1 macrophages contained condensed/fragmented nuclei and increased levels of activated caspase-3 indicating induction of apoptosis. In MDM, 3–5% of the cells also highly over-expressed apoE, up to 50-fold higher than the rest of the population; however, this was not associated with obvious nuclear alterations. The apoE over-expressing MDM were larger, more granular, and more autofluorescent than the majority of cells and they contained numerous vesicle-like structures that appeared to be coated by apoE. Flow cytometry experiments indicated that the apoE over-expressing subpopulation of MDM were positive for CD14, CD11b/Mac-1 and CD68. These observations suggest that specific macrophage subpopulations may be important for apoE-mediated immunoregulation and clearly indicate that subpopulation heterogeneity should be taken into account when investigating macrophage apoE expression. PMID:15500620

  18. Endotoxin Contamination of Apolipoprotein A-I: Effect on Macrophage Proliferation – A Cautionary Tale

    PubMed Central

    Jin, Xueting; Xu, Qing; Champion, Keith; Kruth, Howard S.

    2015-01-01

    This technical report addresses the problem of endotoxin contamination of apolipoprotein reagents. Using a bromodeoxyuridine incorporation cell proliferation assay, we observed that human plasma ApoA-I as low as 1 μg/ml resulted in a >90% inhibition in macrophage proliferation. However, not all ApoA-I from different sources showed this effect. We considered the possibility that endotoxin contamination of the apolipoproteins contributed to the differential inhibition of macrophage cell proliferation. Endotoxin alone very potently inhibited macrophage proliferation (0.1 ng/ml inhibited macrophage proliferation >90%). Measurement of endotoxin levels in the apolipoprotein products, including an analysis of free versus total endotoxin, the latter which included endotoxin that was masked due to binding to protein, suggested that free endotoxin mediated inhibition of macrophage proliferation. Despite the use of an advanced endotoxin removal procedure and agents commonly used to inhibit endotoxin action, the potency of endotoxin precluded successful elimination of endotoxin effect. Our findings show that endotoxin contamination can significantly influence apparent apolipoprotein-mediated cell effects (or effects of any other biological products), especially when these products are tested on highly endotoxin-sensitive cells, such as macrophages. PMID:25778625

  19. Reduced concentrations of apolipoproteins B-100 and A-I in serum from cows with retained placenta.

    PubMed Central

    Oikawa, S; Katoh, N

    1997-01-01

    The purpose of the present study was to evaluate apolipoprotein B-100 and A-I concentrations in cows with retained placenta. Animals used were cows with retained placenta alone (n = 10), those with both retained placenta and ketosis (n = 7), and controls (n = 10). Apolipoprotein B-100 concentrations at 2 to 4 d after parturition were significantly (P < 0.01) decreased in cows with retained placenta alone (mean +/- SD, 0.084 +/- 0.029 mg/ML of serum) when compared with those in control cows (0.154 +/- 0.022 mg/mL). Apolipoprotein A-I concentrations (0.713 +/- 0.177 mg/ML) were also significantly (P < 0.05) lower than those of controls (0.895 +/- 0.159 mg/mL). These decreases were more distinct for apolipoproteins B-100 (55% of controls) than A-I concentrations (80% of controls). Concentrations of apolipoprotein B-100 (0.071 +/- 0.032 mg/mL; P < 0.01) and A-I (0.708 +/- 0.189 mg/mL; P < 0.05) in the cows with both retained placenta and ketosis were also reduced, when compared with values in controls. Other than apolipoproteins, cows with retained placenta alone had significantly (P < 0.01) higher serum nonesterified fatty acids, and lower triglyceride concentrations. Significantly (P < 0.01) higher nonesterified fatty acids and lower triglyceride concentrations were similarly observed in cows with both retained placenta and ketosis. PMID:9342458

  20. Serum concentrations of cholesterol, apolipoprotein A-I, and apolipoprotein B in a total of 1 694 meat-eaters, fish-eaters, vegetarians, and vegans

    PubMed Central

    Bradbury, Kathryn E; Crowe, Francesca L; Appleby, Paul N; Schmidt, Julie A; Travis, Ruth C; Key, Timothy J

    2013-01-01

    BACKGROUND The objective of this study was to describe serum lipid concentrations, including apolipoproteins A-I and B, in different diet groups. METHODS A cross-sectional analysis of a sample of 424 meat-eaters, 425 fish-eaters, 423 vegetarians, and 422 vegans, matched on sex and age, from the European Prospective Investigation into Cancer and Nutrition (EPIC)-Oxford cohort. Serum concentrations of total, and HDL cholesterol, as well as apolipoproteins A-I and B were measured, and serum non-HDL cholesterol was calculated. RESULTS Vegans had the lowest BMI, and the highest and lowest intakes of polyunsaturated and saturated fat, respectively. After adjustment for age, alcohol and physical activity, compared to meat-eaters, fish-eaters and vegetarians, serum concentrations of total and non-HDL cholesterol, and apolipoprotein B were significantly lower in vegans. Serum apolipoprotein A-I concentrations did not differ between the diet groups. In males, the mean serum total cholesterol concentration was 0.87 nmol/L lower in vegans than in meat-eaters; after further adjustment for BMI this difference was 0.76 nmol/L. In females, the difference in total cholesterol between these two groups was 0.60 nmol/L, and after further adjustment for BMI was 0.55 nmol/L. CONCLUSIONS In this study, which included a large number of vegans, serum total cholesterol and apolipoprotein B concentrations were lower in vegans compared to meat-eaters, fish-eaters and vegetarians. A small proportion of the observed differences in serum lipid concentrations was explained by differences in BMI, but a large proportion is most likely due to diet. PMID:24346473

  1. Membrane effects of N-terminal fragment of apolipoprotein A-I: a fluorescent probe study.

    PubMed

    Trusova, Valeriya; Gorbenko, Galyna; Girych, Mykhailo; Adachi, Emi; Mizuguchi, Chiharu; Sood, Rohit; Kinnunen, Paavo; Saito, Hiroyuki

    2015-03-01

    The binding of monomeric and aggregated variants of 1-83 N-terminal fragment of apolipoprotein A-I with substitution mutations G26R, G26R/W@8, G26R/W@50 and G26R/W@72 to the model lipid membranes composed of phosphatidylcholine and its mixture with cholesterol has been investigated using fluorescent probes pyrene and Laurdan. Examination of pyrene spectral behavior did not reveal any marked influence of apoA-I mutants on the hydrocarbon region of lipid bilayer. In contrast, probing the membrane effects by Laurdan revealed decrease in the probe generalized polarization in the presence of aggregated proteins. suggesting that oligomeric and fibrillar apoA-I species induce increase in hydration degree and reduction of lipid packing density in the membrane interfacial region. These findings may shed light on molecular details of amyloid cytotoxicity. PMID:25595057

  2. Adsorption of apolipoprotein A-I to biological membranes. A statistical mechanical model

    NASA Astrophysics Data System (ADS)

    Gross, Eitan

    2012-07-01

    Apolipoprotein A-I (apo A-I), the main protein component of high-density lipoprotein (HDL), reduces the risk for atherosclerosis by removing cholesterol from the membrane of foam cells. Experiments with model membrane systems have indicated, however, that membrane cholesterol reduces apo A-I binding to the membrane. Foam cells resolve this discrepancy electrostatically by co-inserting negatively charged phospholipids in their membrane. Here we present a statistical mechanical model to account for the effect of cholesterol. Our model is based on the Haugen and May model which takes into account the dipolar nature of the zwitterionic phospholipid head group in the membrane, in which the positive end of the zwitterionic dipole moment can move randomly on a hemispherical surface with a radius equal to the arm of the dipole moment and with the negative end fixed at the hydrocarbon layer. Adsorption of a positively charged apo A-I macroion to the surface of the membrane modifies the electric field within the head group region and induces lateral demixing of phospholipid molecules in the membrane. Results from numerical integration of model equations show that i) as a result of the strong charge-dipole electrostatic coupling, the positive end of the dipoles tilts away from the adsorbed macroion in a cooperative manner; and ii) cholesterol reduces macroion adsorption to the membrane by reducing the surface area of the membrane and restricting the dipoles range of rotation. Model predictions for the change in free energy of adsorption to zwitterionic membrane are in good agreement with previously reported experimental data with liposomes. The model can assist in designing new mimetic peptides.

  3. Elevated hepatic apolipoprotein A-I transcription is associated with diet-induced hyperalphalipoproteinemia in rabbits.

    PubMed

    Schwab, D A; Rea, T J; Hanselman, J C; Bisgaier, C L; Krause, B R; Pape, M E

    2000-03-24

    Past studies have shown that a high saturated fatty acid diet containing coconut oil elevates plasma HDL cholesterol and apolipoprotein A-I (apoA-1) in rabbits through a mechanism involving increased synthesis. We have extended those studies by investigating expression of the hepatic apolipoprotein A-I gene and other lipid related genes in that model. Rabbits fed a diet containing 14% coconut oil for 4 weeks showed HDL-C elevations of 170% to 250% over chow-fed controls with peak differences occurring at 1 week. Plasma apoA-I levels were also increased over this time frame (160% to 180%) reflecting the HDL-C changes. After 4 weeks, there were no differences in plasma VLDL-C or LDL-C levels in chow versus coconut oil-fed rabbits. Hepatic levels of apoA-I mRNA in coconut oil-fed animals were elevated 150% after 4 weeks compared to chow-fed controls; hepatic mRNA levels for ten other genes either decreased slightly (apoB, LCAT, hepatic lipase, albumin, ACAT, and HMG CoA reductase) or were unchanged (CETP, apoE, LDL-receptor, and acyl CoA oxidase). Nuclear run-on transcription assays revealed that coconut oil feeding for 4 weeks caused a 220% increase in hepatic apoA-I transcription rate compared to controls; no change was observed for CETP and apoE. Treatment of cultured rabbit liver cells with various saturated fatty acids and sera from chow-fed and coconut oil-fed rabbits did not alter apoA-I mRNA levels as observed in vivo. These data demonstrate that coconut oil elevates plasma HDL-C and apoA-I by increasing hepatic apoA-I transcription while expression of other genes involved in lipid metabolism are reduced or unchanged in response to coconut oil feeding. PMID:10809165

  4. A cDNA-dependent scintillation proximity assay for quantifying apolipoprotein A-I.

    PubMed

    Hanselman, J C; Schwab, D A; Rea, T J; Bisgaier, C L; Pape, M E

    1997-11-01

    We have developed a cDNA-dependent scintillation proximity assay (SPA) for rabbit apolipoprotein A-I that follows a classic radioimmunoassay scheme, in that antiserum and radiolabeled ligand are used in a process to quantify a source containing unlabeled ligand. To synthesize radiolabeled ligand we isolated a full-length rabbit apolipoprotein A-I (apoA-I) cDNA, transcribed the corresponding RNA in vitro, and synthesized radiolabeled apoA-I by including tritiated leucine in an in vitro translation reaction. Assay conditions were established which allowed quantification of unlabeled apoA-I over a range of 0.2 to 4 nanograms with intra- and interassay coefficients of variation of 5% and 10%, respectively. Purified rabbit apoA-I, apoA-I in rabbit liver parenchymal cell conditioned media, and apoA-I contained in rabbit plasma all generated parallel titration curves. Quantification of rabbit plasma apoA-I was not affected when sheep anti-rabbit apoA-I serum was mixed with sheep anti-rabbit apoB or apoE serum; thus, the antibody need not be specific to quantify the ligand of interest. To show utility of the assay, apoA-I mass was quantified in in vitro and in vivo models displaying altered apoA-I levels. In each model apoA-I values from the cDNA-dependent SPA and the established methodologies of Western blotting and electroimmunodiffusion were highly correlated. The approach outlined in this report should permit rapid development of scintillation proximity assays for other proteins given the widespread availability of full-length cDNAs. PMID:9392434

  5. Interactions between lipid-free apolipoprotein-AI and a lipopeptide incorporating the RGDS cell adhesion motif

    NASA Astrophysics Data System (ADS)

    Castelletto, V.; Hamley, I. W.; Reza, M.; Ruokolainen, J.

    2014-11-01

    The interaction of a designed bioactive lipopeptide C16-GGGRGDS, comprising a hexadecyl lipid chain attached to a functional heptapeptide, with the lipid-free apoliprotein, Apo-AI, is examined. This apolipoprotein is a major component of high density lipoprotein and it is involved in lipid metabolism and may serve as a biomarker for cardiovascular disease and Alzheimers' disease. We find via isothermal titration calorimetry that binding between the lipopeptide and Apo-AI occurs up to a saturation condition, just above equimolar for a 10.7 μM concentration of Apo-AI. A similar value is obtained from circular dichroism spectroscopy, which probes the reduction in α-helical secondary structure of Apo-AI upon addition of C16-GGGRGDS. Electron microscopy images show a persistence of fibrillar structures due to self-assembly of C16-GGGRGDS in mixtures with Apo-AI above the saturation binding condition. A small fraction of spheroidal or possibly ``nanodisc'' structures was observed. Small-angle X-ray scattering (SAXS) data for Apo-AI can be fitted using a published crystal structure of the Apo-AI dimer. The SAXS data for the lipopeptide/Apo-AI mixtures above the saturation binding conditions can be fitted to the contribution from fibrillar structures coexisting with flat discs corresponding to Apo-AI/lipopeptide aggregates.

  6. The intracellular quality control system down-regulates the secretion of amyloidogenic apolipoprotein A-I variants: a possible impact on the natural history of the disease.

    PubMed

    Marchesi, Marta; Parolini, Cinzia; Valetti, Caterina; Mangione, Palma; Obici, Laura; Giorgetti, Sofia; Raimondi, Sara; Donadei, Simona; Gregorini, Gina; Merlini, Giampaolo; Stoppini, Monica; Chiesa, Giulia; Bellotti, Vittorio

    2011-01-01

    Hereditary systemic amyloidosis caused by apolipoprotein A-I variants is a dominantly inherited disease characterised by fibrillar deposits mainly localized in the kidneys, liver, testis and heart. We have previously shown that the apolipoprotein A-I variant circulates in plasma at lower levels than the wild-type form (Mangione et al., 2001; Obici et al., 2004) thus raising the possibility that the amyloid deposits could sequester the circulating amyloidogenic chain or that the intracellular quality control can catch and capture the misfolded amyloidogenic chain before the secretion. In this study we have measured plasma levels of the wild-type and the variant Leu75Pro apolipoprotein A-I in two young heterozygous carriers in which tissue amyloid deposition was still absent. In both cases, the mutant was present at significantly lower levels than the wild-type form, thus indicating that the low plasma concentration of the apolipoprotein A-I variant is not a consequence of the protein entrapment in the amyloid deposits. In order to explore the cell secretion of amyloidogenic apolipoprotein A-I variants, we have studied COS-7 cells expressing either wild-type apolipoprotein A-I or two amyloidogenic mutants: Leu75Pro and Leu174Ser. Quantification of intracellular and extracellular apolipoprotein A-I alongside the intra-cytoplasmatic localization indicates that, unlike the wild-type protein, both variants are retained within the cells and mainly accumulate in the endoplasmic reticulum. The low plasma concentration of amyloidogenic apolipoprotein A-I may therefore be ascribed to the activity of the intracellular quality control that represents a first line of defence against the secretion of pathogenic variants. PMID:20637862

  7. Interactions of Apolipoproteins AI, AII, B and HDL, LDL, VLDL with Polyurethane and Polyurethane-PEO Surfaces.

    PubMed

    Cornelius, R M; Macri, J; Cornelius, K M; Brash, J L

    2015-11-10

    The lipoproteins (HDL, LDL, VLDL) are important components of blood present in high concentration. Surprisingly, their role in blood-biomaterial interactions has been largely ignored. In previous work apolipoprotein AI (the main protein component of HDL) was identified as a major constituent of protein layers adsorbed from plasma to biomaterials having a wide range of surface properties, and quantitative data on the adsorption of apo AI to a biomedical grade polyurethane were reported. In the present communication quantitative data on the adsorption of apo AI, apo AII and apoB (the latter being a constituent of LDL and VLDL), as well as the lipoprotein particles themselves (HDL, LDL, VLDL), to a biomedical segmented polyurethane (PU) with and without an additive containing poly(ethylene oxide) (material referred to as PEO) are reported. Using radiolabeled apo AI, apo AII, and apoB, adsorption levels on PU from buffer at a protein concentration of 50 μg/mL were found to be 0.34, 0.40, and 0.14 μg/cm(2) (12, 23, and 0.25 nmol/cm(2)) respectively. Adsorption to the PEO surface was <0.02 μg/cm(2) for all three apolipoproteins demonstrating the strong protein resistance of this material. In contrast to the apolipoproteins, significant amounts of the lipoproteins were found to adsorb to the PEO as well as to the PU surface. X-ray photoelectron spectra, following exposure of the surfaces to the lipoproteins, showed a strong phosphorus signal, confirming that adsorption had occurred. It therefore appears that a PEO-containing surface that is resistant to apolipoproteins may be less resistant to the corresponding lipoproteins. PMID:26513526

  8. Formation of stable nanodiscs by bihelical apolipoprotein A-I mimetic peptide.

    PubMed

    Kariyazono, Hirokazu; Nadai, Ryo; Miyajima, Rin; Takechi-Haraya, Yuki; Baba, Teruhiko; Shigenaga, Akira; Okuhira, Keiichiro; Otaka, Akira; Saito, Hiroyuki

    2016-02-01

    Nanodiscs are composed of scaffold protein or peptide such as apolipoprotein A-I (apoA-I) and phospholipids. Although peptide-based nanodiscs have an advantage to modulate the size of nanodiscs by changing phospholipid/peptide ratios, they are usually less stable than apoA-I-based nanodiscs. In this study, we designed a novel nanodisc scaffold peptide (NSP) that has proline-punctuated bihelical amphipathic structure based on apoA-I mimetic peptides. NSP formed α-helical structure on 1-palmitoyl-2-oleoyl phosphatidylcholine (POPC) nanodiscs prepared by cholate dialysis method. Dynamic light scattering measurements demonstrated that diameters of NSP nanodiscs vary depending upon POPC/NSP ratios. Comparison of thermal unfolding of nanodiscs monitored by circular dichroism measurements demonstrated that NSP forms much more stable nanodiscs with POPC than monohelical peptide, 4F, exhibiting comparable stability to apoA-I-POPC nanodiscs. Intrinsic Trp fluorescence measurements showed that Trp residues of NSP exhibit more hydrophobic environment than that of 4 F on nanodiscs, suggesting the stronger interaction of NSP with phospholipids. Thus, the bihelical structure of NSP appears to increase the stability of nanodiscs because of the enhanced interaction of peptides with phospholipids. In addition, NSP as well as 4F spontaneously solubilized POPC vesicles into nanodiscs without using detergent. These results indicate that bihelical NSP forms nanodiscs with comparable stability to apoA-I and has an ability to control the size of nanodiscs simply by changing phospholipid/peptide ratios. PMID:26780967

  9. Marked high density lipoprotein deficiency due to apolipoprotein A-I Tomioka (codon 138 deletion).

    PubMed

    Wada, Masamichi; Iso, Tatsuya; Asztalos, Bela F; Takama, Noriaki; Nakajima, Tadashi; Seta, Yukihiro; Kaneko, Katsumi; Taniguchi, Yasuhiro; Kobayashi, Hideo; Nakajima, Katsuyuki; Schaefer, Ernst J; Kurabayashi, Masahiko

    2009-11-01

    We report a novel apolipoprotein A-I (apoA-I) mutation identified in a 64-year-old patient with marked plasma high density lipoprotein (HDL) cholesterol (4 mg/dl) and apoA-I (5mg/dl) deficiency, prior myocardial infarction, and moderate corneal opacities. Coronary angiography revealed extensive atherosclerosis in all three major vessels. Genomic DNA sequencing of the proband revealed a homozygous novel deletion of two successive adenine residues in codon 138 in the apoA-I gene, resulting in a frameshift mutation at amino acid residues 138-178, which we have designated as apoA-I Tomioka. His elder brother was also homozygous for apoA-I Tomioka with marked HDL cholesterol and apoA-I deficiency, but had no clinical evidence of coronary heart disease. Other family members including three siblings and two sons were heterozygous for the mutation, and had approximately 50% of normal plasma HDL cholesterol, and apoA-I. Analysis of apoA-I-containing HDL particles by two-dimensional gel electrophoresis revealed undetectable apoA-I HDL particles in the homozygotes, while in heterozygotes, the mean concentrations of apoA-I in large alpha-1 and very small prebeta-1 HDL subpopulations were significantly decreased at about 35% of normal. Thus, apoA-I Tomioka, a novel deletion mutation in codon 138 of the apoA-I gene, is the causative defect in this case of HDL deficiency. PMID:19473658

  10. Effect of the amyloidogenic L75P apolipoprotein A-I variant on HDL subpopulations

    PubMed Central

    Gomaraschi, Monica; Obici, Laura; Simonelli, Sara; Gregorini, Gina; Negrinelli, Alessandro; Merlini, Giampaolo; Franceschini, Guido; Calabresi, Laura

    2011-01-01

    Background Hereditary amyloidosis due to mutations of apolipoprotein A-I (apoA-I) is a rare disease characterized by the deposition of amyloid fibrils constituted by the N-terminal fragment of apoA-I in several organs. L75P is a variant of apoA-I associated with systemic amyloidosis predominantly involving the liver, kidneys, and testis, identified in a large number of unrelated subjects. Objective of the present paper was to evaluate the impact of the L75P apoA-I variant on HDL subpopulations and cholesterol esterification in carriers. Methods and results Plasma samples were collected from 30 carriers of the amyloidogenic L75P apoA-I (Carriers) and from 15 non affected relatives (Controls). Carriers displayed significantly reduced plasma levels of HDL-cholesterol, apoA-I, and apoA-II compared to Controls. Plasma levels of LpA-I, but not LpA-I:A-II, were significantly reduced in Carriers. HDL subclass distribution was not affected by the presence of the variant. The unesterified to total cholesterol ratio was higher, and cholesterol esterification rate and LCAT activity were lower in Carriers than in Controls. Conclusions The L75P apoA-I variant is associated with hypoalphalipoproteinemia, a selective reduction of LpA-I particles, and a partial defect in cholesterol esterification. PMID:21458433

  11. Role of apolipoprotein A-I in HDL binding to a rat hepatoma cell in culture

    SciTech Connect

    Gottlieb, B.A.

    1985-01-01

    The binding of HDL to rat Fu5AH hepatoma cells at 4/sup 0/, and uptake and degradation at 37/sup 0/, was investigated in monolayer cultures. HDL, free of apo E and apo A-IV, was obtained from the plasma of nephrotic rats (HDLne). /sup 125/I-labeled HDLne bound to the cells in a specific, saturable manner. By Scatchard analysis, two classes of binding sites were obtained: a high affinity binding site (Kd = 1.25 +/- 0.023 ..mu..g/ml, or 5 x 10/sup -9/ M), and a lower affinity site (Kd = 45 +/- 15 ..mu..g/ml, or 1.8 x 10/sup -7/ M). In competitive binding experiments, normal rat HDL was nearly as effective as HDLne, but rat VLDL and human lipoproteins were ineffective. Rat apo A-I/phospholipid complexes also did not complete effectively for HDLne binding, although they were capable of binding to the cells. However, LDL (1.02 < d < 1.063) from nephrotic rat plasma, containing 20% of apo A-I, was as effective as rat HDL in competing for HDLne binding when the competition was expressed as a function of apo A-I content. Control experiments indicated that labeled apo A-I from HDLne did not exchange appreciably with unlabeled apo A-I on the LDLne. When the hepatoma cells were allowed to internalize and degrade HDLne at 37/sup 0/, the acid-soluble products (iodotyrosine and iodide) were derived almost entirely from the breakdown of apo A-I. We conclude that the rat hepatoma cell (Fu5AH) has high affinity HDL binding sites which recognize apo A-I-lipid complexes in which apo A-I an appropriate conformation.

  12. The Effect of Preoperative Apolipoprotein A-I on the Prognosis of Surgical Renal Cell Carcinoma

    PubMed Central

    Guo, Shengjie; He, Xiaobo; Chen, Qian; Yang, Guangwei; Yao, Kai; Dong, Pei; Ye, Yunlin; Chen, Dong; Zhang, Zhiling; Qin, Zike; Liu, Zhuowei; Li, Zaishang; Xue, Yunfei; Zhang, Meng; Liu, Ruiwu; Zhou, Fangjian; Han, Hui

    2016-01-01

    Abstract The prognostic value of serum lipid-profile in renal cell cancer (RCC) remains unknown. The purpose of the study is to explore the association between the serum lipid-profile and RCC patients. The levels of preoperative serum lipid-profile (including cholesterol, triglycerides, high-density lipoprotein-cholesterol [HDL-C], low-density lipoprotein-cholesterol [LDL-C], apolipoprotein A-I [ApoA-I], and apolipoprotein B [ApoB]) were retrospectively performed in 786 patients with RCC. The cutoff values of the lipids were determined by the receiver-operating characteristic (ROC) curve analysis. Univariate and multivariate Cox regression analyses were performed to investigate the prognostic value of serum lipids in RCC. Combined ROC analysis and univariate and multivariate Cox regression analyses, for overall survival (OS), revealed patients with low ApoA-I (<1.04) had significantly lower OS than the high ApoA-I (≥1.04) group (multivariate Cox regression analyses, hazard ratio [HR], 0.57; P = 0.003). Not only in the whole RCC cohort but also in the subgroups stratified according to the pT1-2 (P = 0.002), pN0 (P < 0.001), and pM0 (P = 0.001) status, respectively. Moreover, in the 755 patients with nonmetastasis, the low ApoA-I group was also associated with shortened disease-free survival (DFS) time compared to the high ApoA-I group (multivariate Cox regression analyses, HR, 0.65; P = 0.033). However, the other lipids were not independent prognostic factors for surgical RCC. An elevated level of preoperative ApoA-I was demonstrated to be related with better survival in patients with surgical RCC. Measuring the preoperative ApoA-I might be a simple way for finding the poor prognostic patients who should enrolled in further clinical trials and management. PMID:27015197

  13. Surface-induced assembly of apolipoprotein A-I: Implications for symmetry-driven non-cooperative clustering

    NASA Astrophysics Data System (ADS)

    Winford, Sidney; Tobin, Moriah; Gross, Eitan

    2012-03-01

    In condensed matter physics the geometry of a crystal is determined by the mechanism of condensation. In biology, the link between clustering mechanisms and the shape of a protein crystal is not well defined. To gain more insight into the problem, we studied clustering of apolipoprotein A-I (apo A-I) on a solid surface using AFM. The amyloidogenic protein apo A-I is the main protein component of high density lipoprotein and thus reduces the risk of atherosclerosis. We found that apo A-I clustered to form nano-scale, symmetrical clusters on mica. Statistical analysis of size distribution for several thousand clusters suggested that the clustering reaction followed a non-cooperative kinetic scheme characterized by a single equilibrium constant of 0.92·106 M-1 and a change in free energy (ΔG) of -0.03 kJ mole-1/residue. This is close to ΔG of-0.04 kJ mole-1/residue for apo A-I binding to phospholipid membrane; and 30-fold smaller than ΔG for β-amyloid formation by apo A-I. The high symmetry of the clusters is consistent with an isotropic diffusion coefficient of protein monomers on the surface of the substrate. This previously unrecognized link between protein clustering mechanism and the symmetry of the growth pattern may have important implications in medicine, pharmaceutics and polymer science.

  14. Myeloperoxidase-mediated Methionine Oxidation Promotes an Amyloidogenic Outcome for Apolipoprotein A-I*

    PubMed Central

    Chan, Gary K. L.; Witkowski, Andrzej; Gantz, Donald L.; Zhang, Tianqi O.; Zanni, Martin T.; Jayaraman, Shobini; Cavigiolio, Giorgio

    2015-01-01

    High plasma levels of apolipoprotein A-I (apoA-I) correlate with cardiovascular health, whereas dysfunctional apoA-I is a cause of atherosclerosis. In the atherosclerotic plaques, amyloid deposition increases with aging. Notably, apoA-I is the main component of these amyloids. Recent studies identified high levels of oxidized lipid-free apoA-I in atherosclerotic plaques. Likely, myeloperoxidase (MPO) secreted by activated macrophages in atherosclerotic lesions is the promoter of such apoA-I oxidation. We hypothesized that apoA-I oxidation by MPO levels similar to those present in the artery walls in atherosclerosis can promote apoA-I structural changes and amyloid fibril formation. ApoA-I was exposed to exhaustive chemical (H2O2) oxidation or physiological levels of enzymatic (MPO) oxidation and incubated at 37 °C and pH 6.0 to induce fibril formation. Both chemically and enzymatically oxidized apoA-I produced fibrillar amyloids after a few hours of incubation. The amyloid fibrils were composed of full-length apoA-I with differential oxidation of the three methionines. Met to Leu apoA-I variants were used to establish the predominant role of oxidation of Met-86 and Met-148 in the fibril formation process. Importantly, a small amount of preformed apoA-I fibrils was able to seed amyloid formation in oxidized apoA-I at pH 7.0. In contrast to hereditary amyloidosis, wherein specific mutations of apoA-I cause protein destabilization and amyloid deposition, oxidative conditions similar to those promoted by local inflammation in atherosclerosis are sufficient to transform full-length wild-type apoA-I into an amyloidogenic protein. Thus, MPO-mediated oxidation may be implicated in the mechanism that leads to amyloid deposition in the atherosclerotic plaques in vivo. PMID:25759391

  15. Apolipoprotein A-I Helsinki promotes intracellular acyl-CoA cholesterol acyltransferase (ACAT) protein accumulation.

    PubMed

    Toledo, Juan D; Garda, Horacio A; Cabaleiro, Laura V; Cuellar, Angela; Pellon-Maison, Magali; Gonzalez-Baro, Maria R; Gonzalez, Marina C

    2013-05-01

    Reverse cholesterol transport is a process of high antiatherogenic relevance in which apolipoprotein AI (apoA-I) plays an important role. The interaction of apoA-I with peripheral cells produces through mechanisms that are still poorly understood the mobilization of intracellular cholesterol depots toward plasma membrane. In macrophages, these mechanisms seem to be related to the modulation of the activity of acyl-CoA cholesterol acyltransferase (ACAT), the enzyme responsible for the intracellular cholesterol ester biosynthesis that is stored in lipid droplets. The activation of ACAT and the accumulation of lipid droplets play a key role in the transformation of macrophages into foam cells, leading to the formation of atheroma or atherosclerotic plaque. ApoA-I Helsinki (or ∆K107) is a natural apoA-I variant with a lysine deletion in the central protein region, carriers of which have increased atherosclerosis risk. We herein show that treatment of cultured RAW macrophages or CHOK1 cells with ∆K107, but not with wild-type apoA-I or a variant containing a similar deletion at the C-terminal region (∆K226), lead to a marked increase (more than 10 times) in the intracellular ACAT1 protein level as detected by western blot analysis. However, we could only detect a slight increase in cholesteryl ester produced by ∆K107 mainly when Chol loading was supplied by low-density lipoprotein (LDL). Although a similar choline-phospholipid efflux is evoked by these apoA-I variants, the change in phosphatidylcholine/sphyngomyelin distribution produced by wild-type apoA-I is not observed with either ∆K107 or ∆K226. PMID:23456478

  16. Assignment of the binding site for haptoglobin on apolipoprotein A-I.

    PubMed

    Spagnuolo, Maria Stefania; Cigliano, Luisa; D'Andrea, Luca D; Pedone, Carlo; Abrescia, Paolo

    2005-01-14

    Haptoglobin (Hpt) was previously found to bind the high density lipoprotein (HDL) apolipoprotein A-I (ApoA-I) and able to inhibit the ApoA-I-dependent activity of the enzyme lecithin:cholesterol acyltransferase (LCAT), which plays a major role in the reverse cholesterol transport. The ApoA-I structure was analyzed to detect the site bound by Hpt. ApoA-I was treated by cyanogen bromide or hydroxylamine; the resulting fragments, separated by electrophoresis or gel filtration, were tested by Western blotting or enzyme-linked immunosorbent assay for their ability to bind Hpt. The ApoA-I sequence from Glu113 to Asn184 harbored the binding site for Hpt. Biotinylated peptides were synthesized overlapping such a sequence, and their Hpt binding activity was determined by avidin-linked peroxidase. The highest activity was exhibited by the peptide P2a, containing the ApoA-I sequence from Leu141 to Ala164. Such a sequence contains an ApoA-I domain required for binding cells, promoting cholesterol efflux, and stimulating LCAT. The peptide P2a effectively prevented both binding of Hpt to HDL-coated plastic wells and Hpt-dependent inhibition of LCAT, measured by anti-Hpt antibodies and cholesterol esterification activity, respectively. The enzyme activity was not influenced, in the absence of Hpt, by P2a. Differently from ApoA-I or HDL, the peptide did not compete with hemoglobin for Hpt binding in enzyme-linked immunosorbent assay experiments. The results suggest that Hpt might mask the ApoA-I domain required for LCAT stimulation, thus impairing the HDL function. Synthetic peptides, able to displace Hpt from ApoA-I without altering its property of binding hemoglobin, might be used for treatment of diseases associated with defective LCAT function. PMID:15533931

  17. Influence of cholesteryl ester transfer protein, peroxisome proliferator-activated receptor alpha, apolipoprotein E, and apolipoprotein A-I polymorphisms on high-density lipoprotein cholesterol, apolipoprotein A-I, lipoprotein A-I, and lipoprotein A-I:A-II concentrations: the Prospective Epidemiological Study of Myocardial Infarction study.

    PubMed

    Do, Hong Quang; Nazih, Hassan; Luc, Gérald; Arveiler, Dominique; Ferrières, Jean; Evans, Alun; Amouyel, Philippe; Cambien, François; Ducimetière, Pierre; Bard, Jean-Marie

    2009-03-01

    The plasma level of high-density lipoprotein cholesterol (HDL-C) is known to be inversely associated with cardiovascular risk. However, besides lifestyle, gene polymorphism may influence the HDL-C concentration. The aim of this study was to investigate the possibility of interactions between CETP, PPARA, APOE, and APOAI polymorphisms and HDL-C, apolipoprotein (apo) A-I, lipoprotein (Lp) A-I, and Lp A-I:A-II in a sample selected from the Prospective Epidemiological Study of Myocardial Infarction (PRIME) study population who remained free of cardiovascular events over 5 years of follow-up. Healthy individuals (857) were randomly selected for genotyping the PRIME study subjects. The population was selected so as to provide 25% of subjects in the lowest tertile of HDL-C (< or = 28 mg/dL) in the whole PRIME study sample, 25% of subjects in the highest tertile of HDL-C (> or = 73 mg/dL), and 50% of subjects in the medium tertile of HDL-C (28-73 mg/dL). Genotyping was performed by using a polymerase chain reaction system with predeveloped TaqMan allelic discrimination assay. The CETP A373P rare allele c was less frequent in the group of subjects with high HDL-C, apo A-I, Lp A-I, and Lp A-I:A-II concentrations. Apolipoprotein A-I and Lp A-I were also found to be higher in the presence of the epsilon2 allele coding for APOE. The effect of the CETP A373P rare allele c on HDL-C was independent of all tested parameters except triglycerides. The respective effect of these polymorphisms and triglycerides on cardiovascular risk should be evaluated prospectively. PMID:19217440

  18. High 99mTc-DPD myocardial uptake in a patient with apolipoprotein AI-related amyloidotic cardiomyopathy.

    PubMed

    Quarta, Candida Cristina; Obici, Laura; Guidalotti, Pier Luigi; Pieroni, Maurizio; Longhi, Simone; Perlini, Stefano; Verga, Laura; Merlini, Giampaolo; Rapezzi, Claudio

    2013-03-01

    Amyloidotic cardiomyopathy is still a widely underdiagnosed condition that usually requires endomyocardial biopsy (EMB) for a definite diagnosis. 99mTc-3,3-diphosphono-1,2-propanodicarboxylic acid (99mTc-DPD) has proven highly sensitive for detecting amyloidotic cardiomyopathy due to transthyretin-related amyloid deposition. Herein we report the first description of the (99mTc-DPD scintigraphy profile in a patient with suspected amyloidotic cardiomyopathy and a final EMB- and genetically-proven diagnosis of familial apolipoprotein AI amyloidosis due to Leu174Ser variant. PMID:23231421

  19. Effects of native and myeloperoxidase-modified apolipoprotein A-I on reverse cholesterol transport and atherosclerosis in mice

    PubMed Central

    Hewing, Bernd; Parathath, Saj; Barrett, Tessa; Chung, Wing Ki Kellie; Astudillo, Yaritzy M.; Hamada, Tadateru; Ramkhelawon, Bhama; Tallant, Thomas C.; Yusufishaq, Mohamed Shaif S.; DiDonato, Joseph A.; Huang, Ying; Buffa, Jennifer; Berisha, Stela Z.; Smith, Jonathan D.; Hazen, Stanley L.; Fisher, Edward A.

    2014-01-01

    Objective Preclinical and clinical studies have shown beneficial effects of infusions of apolipoprotein A-I (ApoA-I) on atherosclerosis. ApoA-I is also a target for myeloperoxidase (MPO)-mediated oxidation, leading in vitro to a loss of its ability to promote ABCA1-dependent macrophage cholesterol efflux. Therefore, we hypothesized that MPO-mediated ApoA-I oxidation would impair its promotion of reverse cholesterol transport (RCT) in vivo and the beneficial effects on atherosclerotic plaques. Approach and Results ApoA-I−/− or ApoE−/− mice were subcutaneously injected with native human ApoA-I, oxidized human ApoA-I (oxApoAI; MPO/hydrogen peroxide/chloride treated) or carrier. While early post injection (8 hours) levels of total ApoA-I in plasma were similar for native versus oxApoA-I, native ApoA-I primarily resided within the HDL fraction, whereas the majority of oxApoA-I was highly cross-linked and not HDL particle associated, consistent with impaired ABCA1 interaction. In ApoA-I−/− mice, ApoA-I oxidation significantly impaired RCT in vivo. In advanced aortic root atherosclerotic plaques of ApoE−/− mice, native ApoA-I injections led to significant decreases in lipid content, macrophage number, and an increase in collagen content; in contrast, oxApoA-I failed to mediate these changes. The decrease in plaque macrophages with native ApoA-I was accompanied by significant induction of their chemokine receptor CCR7. Furthermore, only native ApoA-I injections led to a significant reduction of inflammatory M1 and increase in anti-inflammatory M2 macrophage markers in the plaques. Conclusions MPO-mediated oxidation renders ApoA-I dysfunctional and unable to: (i) promote RCT; (ii) mediate beneficial changes in the composition of atherosclerotic plaques; and (iii) pacify the inflammatory status of plaque macrophages. PMID:24407029

  20. Elevated Plasma Albumin and Apolipoprotein A-I Oxidation under Suboptimal Specimen Storage Conditions*

    PubMed Central

    Borges, Chad R.; Rehder, Douglas S.; Jensen, Sally; Schaab, Matthew R.; Sherma, Nisha D.; Yassine, Hussein; Nikolova, Boriana; Breburda, Christian

    2014-01-01

    S-cysteinylated albumin and methionine-oxidized apolipoprotein A-I (apoA-I) have been posed as candidate markers of diseases associated with oxidative stress. Here, a dilute-and-shoot form of LC–electrospray ionization–MS requiring half a microliter of blood plasma was employed to simultaneously quantify the relative abundance of these oxidized proteoforms in samples stored at −80 °C, −20 °C, and room temperature and exposed to multiple freeze–thaw cycles and other adverse conditions in order to assess the possibility that protein oxidation may occur as a result of poor sample storage or handling. Samples from a healthy donor and a participant with poorly controlled type 2 diabetes started at the same low level of protein oxidation and behaved similarly; significant increases in albumin oxidation via S-cysteinylation were found to occur within hours at room temperature and days at −20 °C. Methionine oxidation of apoA-I took place on a longer time scale, setting in after albumin oxidation reached a plateau. Freeze–thaw cycles had a minimal effect on protein oxidation. In matched collections, protein oxidation in serum was the same as that in plasma. Albumin and apoA-I oxidation were not affected by sample headspace or the degree to which vials were sealed. ApoA-I, however, was unexpectedly found to oxidize faster in samples with lower surface-area-to-volume ratios. An initial survey of samples from patients with inflammatory conditions normally associated with elevated oxidative stress—including acute myocardial infarction and prostate cancer—demonstrated a lack of detectable apoA-I oxidation. Albumin S-cysteinylation in these samples was consistent with known but relatively brief exposures to temperatures above −30 °C (the freezing point of blood plasma). Given their properties and ease of analysis, these oxidized proteoforms, once fully validated, may represent the first markers of blood plasma specimen integrity based on direct measurement

  1. Apolipoprotein A-I inhibits chemotaxis, adhesion, activation of THP-1 cells and improves the plasma HDL inflammatory index.

    PubMed

    Wang, Li; Chen, Wei-Zhong; Wu, Man-Ping

    2010-02-01

    The anti-inflammatory effects of high density lipoprotein (HDL) are well described, however, such effects of Apolipoprotein A-I (ApoA-I) are less studied. Building on our previous study, we further explored the mechanism of anti-inflammatory effects of ApoA-I, and focused especially on the interaction between monocyte and endothelial cells and plasma HDL inflammatory index in LPS-challenged rabbits. Our results show that ApoA-I significantly decreased LPS-induced MCP-1 release from THP-1 cells and ox-LDL-induced THP-1 migration ratio (P<0.01, respectively). ApoA-I significantly decreased sL-selectin, sICAM-1 and sVCAM-1 release (P<0.01, P<0.01, P<0.05, respectively) from LPS-stimulated THP-1 cells. Furthermore, ApoA-I significantly inhibited LPS-induced CD11b and VCAM-1 expression on THP-1 cells (P<0.01, P<0.05, respectively). ApoA-I diminished LPS-induced mCD14 expression (P<0.01) and NFkappaB nuclear translocation in THP-1 cells. After single dose treatment of ApoA-I, the value of plasma HDL inflammatory index in LPS-challenged rabbits was improved significantly (P<0.05). These results suggest that ApoA-I can inhibit chemotaxis, adhesion and activation of human monocytes and improve plasma HDL inflammatory index with presenting beneficial anti-inflammatory effects. PMID:19819722

  2. A case report of hereditary apolipoprotein A-I amyloidosis associated with a novel APOA1 mutation and variable phenotype.

    PubMed

    Tougaard, Birgitte G; Pedersen, Katja Venborg; Krag, Søren Rasmus; Gilbertson, Janet A; Rowczenio, Dorota; Gillmore, Julian D; Birn, Henrik

    2016-09-01

    Apolipoprotein A-I (apo A-I) amyloidosis is a non-AL, non-AA, and non-transthyretin type of amyloidosis associated with mutations in the APOA1 gene inherited in an autosomal dominant fashion. It is a form of systemic amyloidosis, but at presentation, can also mimic localized amyloidosis. The renal presentation generally involves interstitial and medullary deposition of apo A-I amyloid protein. We describe the identification of apo A-I amyloidosis by mass spectrometry in a 52-year old male, with no family history of amyloidosis, presenting with nephrotic syndrome and associated with heterozygosity for a novel APOA1 mutation (c.220 T > A) which encodes the known amyloidogenic Trp50Arg variant. Renal amyloid deposits in this case were confined to the glomeruli alone, and the patient developed progressive renal impairment. One year after diagnosis, the patient had a successful kidney transplant from an unrelated donor. Pathogenic mutations in the APOA1 gene are generally associated with symptoms of amyloidosis. In this family however, genotyping of family members identified several unaffected carriers suggesting a variable disease penetrance, which has not been described before in this form of amyloidosis and has implications when counselling those with APOA1 mutations. PMID:27240838

  3. Plasma lipid transport in the hedgehog: partial characterization of structure and function of apolipoprotein A-I.

    PubMed

    Sparrow, D A; Laplaud, P M; Saboureau, M; Zhou, G; Dolphin, P J; Gotto, A M; Sparrow, J T

    1995-03-01

    Apart from exhibiting the presence of lipoprotein [a] in its plasma, another interest of the European hedgehog in lipoprotein research lies in the quantitative prominence of a complex spectrum of high density lipoproteins (HDL) and very high density lipoproteins (VHDL) as cholesterol transporters in plasma (Laplaud, P. M. et al. 1989. Biochim. Biophys. Acta. 1005: 143-156). We, therefore, initiated studies in the field of reverse cholesterol transport in the hedgehog. As a first step, we characterized apolipoprotein A-I (apoA-I), the main protein component of hedgehog HDL and VHDL. Proteolytic cleavage of apoA-I (M(r) approx. 27 kDa) using two different enzymes resulted in two sets of peptides that were subsequently purified by high performance liquid chromatography, and that allowed us determination of the complete protein sequence. Hedgehog apoA-I thus consists of 241 amino acid residues and exhibits an overall 58% homology to its human counterpart, i.e., the lowest value observed to date among mammalian species. However, it retained the general organization common to all known apoA-Is, i.e., a series of amphipathic helical segments punctuated by proline residues. Circular dichroism experiments indicated a helical content of approx. 45%, increasing to approx. 58% in the presence of lecithin unilamellar liposomes. Apart from other differences, amino acid composition analysis shows that hedgehog apoA-I contains four isoleucine residues, while this amino acid is totally absent from the corresponding protein in higher mammals. Polyclonal antibodies raised against hedgehog apoA-I failed to detect any cross-reactivity between the animal and human proteins, although comparative prediction of the respective antigenic structures using the Hopp-Woods algorithm indicated that several potentially antigenic sites may occur in similar regions of the protein. Finally, hedgehog apoA-I was shown to be able to activate lecithin:cholesterol acyl transferase, although it was 4 to 5

  4. Genetic and environmental determinants of plasma high density lipoprotein cholesterol and apolipoprotein AI concentrations in healthy middle-aged men.

    PubMed

    Talmud, P J; Hawe, E; Robertson, K; Miller, G J; Miller, N E; Humphries, S E

    2002-03-01

    The effects of common variants of cholesteryl ester transfer protein (CETP) (TaqIB), hepatic lipase (HL) (-514C>T), lipoprotein lipase (LPL) (S447X) and lecithin cholesterol acyl transferase (LCAT) (S208T) on the determination of high density lipoprotein cholesterol (HDL-C) and apolipoprotein AI (apoAI) levels were examined in 2773 healthy middle-aged men participating in the second Northwick Park Heart Study. The extent of gene:gene, gene:smoking and gene:alcohol interactions were determined. For HDL-C levels, only CETP genotype was associated with significant effects (p&0.0001), with the B2 allele being associated with higher levels in both smokers and non-smokers. This interaction was significant at the lowest tertile of TG, suggesting that TG levels were rate limiting. As previously reported, CETP, LPL and HL genotypes were all associated with significant effects on apoAI levels (all p&0.01), with carriers of the rare alleles having higher levels and with no evidence of heterogeneity of effects in smokers and non-smokers. LCAT genotype was not associated with significant effects on either trait. There was no significant interaction between any of the genotypes and alcohol consumption on either HDL-C or apoAI levels. All genotypic effects were additive for HDL-C and apoAI. Environmental and TG levels explained more than 20% and 5.5% of the variance in HDL-C and apoAI, respectively. The novel aspect of this finding is that genetic variation at these loci explained in total only 2.5% of the variance in HDL-C and 1.89% of the variance in apoAI levels. Thus despite the key roles played by these enzymes in HDL metabolism, variation at these loci, at least as detected by these common genotypes, contributes minimally to the variance in HDL-C and apoAI levels in healthy men, highlighting the polygenic and multifactorial control of HDL-C. PMID:12174215

  5. Role of thyroid hormones in apolipoprotein A-I gene expression in rat liver.

    PubMed Central

    Strobl, W; Gorder, N L; Lin-Lee, Y C; Gotto, A M; Patsch, W

    1990-01-01

    To study the regulation of hepatic apo A-I gene expression, we measured synthesis and abundance of cellular apo A-I mRNA and its nuclear precursors in livers of hypothyroid and hyperthyroid rats. In hypothyroid animals, both synthesis and abundance of apo A-I mRNA was reduced to half of control values. After injection of a receptor-saturating dose of triiodothyronine into euthyroid rats, apo A-I gene transcription increased at 20 min, reached a maximum of 179% of control (P less than 0.01) at 3.5 h, and remained elevated for up to 48 h. The abundance of nuclear and total cellular apo A-I mRNA increased at 1 and 2 h, respectively, and exceeded the levels expected from enhanced transcription more than two fold at 24 h after hormone injection. Upon chronic administration of thyroid hormones, levels of nuclear and cytoplasmic apo A-I mRNA remained elevated but transcription of the apo A-I gene fell to 42% of control (P less than 0.01). Thus, thyroid hormones rapidly stimulate apo A-I gene transcription. Posttranscriptional events leading to increased stability of nuclear apo A-I RNA precursors become the principal mechanism for enhanced gene expression in chronic hyperthyroidism and may cause feedback inhibition of apo A-I gene transcription. Our results furthermore imply that the majority of hepatic nuclear apo A-I RNA precursors are degraded in euthyroid animals. Images PMID:2107206

  6. Characterization of High Density Lipoprotein Particles in Familial Apolipoprotein A-I Deficiency With Premature Coronary Atherosclerosis, Corneal Arcus and Opacification, and Tubo-Eruptive and Planar Xanthomas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We describe two male siblings with homozygous familial apolipoprotein (apo) A-I deficiency, markedly decreased high density lipoprotein (HDL) cholesterol levels, undetectable plasma apoA-1, tubo-eruptive and planar xanthomas, and mild corneal arcus and opacification. Sequencing of the apoA-I gene re...

  7. Lysine residues direct the chlorination of tyrosines in YXXK motifs of apolipoprotein A-I when hypochlorous acid oxidizes high density lipoprotein.

    PubMed

    Bergt, Constanze; Fu, Xiaoyun; Huq, Nabiha P; Kao, Jeff; Heinecke, Jay W

    2004-02-27

    Oxidized lipoproteins may play an important role in the pathogenesis of atherosclerosis. Elevated levels of 3-chlorotyrosine, a specific end product of the reaction between hypochlorous acid (HOCl) and tyrosine residues of proteins, have been detected in atherosclerotic tissue. Thus, HOCl generated by the phagocyte enzyme myeloperoxidase represents one pathway for protein oxidation in humans. One important target of the myeloperoxidase pathway may be high density lipoprotein (HDL), which mobilizes cholesterol from artery wall cells. To determine whether activated phagocytes preferentially chlorinate specific sites in HDL, we used tandem mass spectrometry (MS/MS) to analyze apolipoprotein A-I that had been oxidized by HOCl. The major site of chlorination was a single tyrosine residue located in one of the protein's YXXK motifs (where X represents a nonreactive amino acid). To investigate the mechanism of chlorination, we exposed synthetic peptides to HOCl. The peptides encompassed the amino acid sequences YKXXY, YXXKY, or YXXXY. MS/MS analysis demonstrated that chlorination of tyrosine in the peptides that contained lysine was regioselective and occurred in high yield if the substrate was KXXY or YXXK. NMR and MS analyses revealed that the N(epsilon) amino group of lysine was initially chlorinated, which suggests that chloramine formation is the first step in tyrosine chlorination. Molecular modeling of the YXXK motif in apolipoprotein A-I demonstrated that these tyrosine and lysine residues are adjacent on the same face of an amphipathic alpha-helix. Our observations suggest that HOCl selectively targets tyrosine residues that are suitably juxtaposed to primary amino groups in proteins. This mechanism might enable phagocytes to efficiently damage proteins when they destroy microbial proteins during infection or damage host tissue during inflammation. PMID:14660678

  8. Intake of cooked tomato sauce preserves coronary endothelial function and improves apolipoprotein A-I and apolipoprotein J protein profile in high-density lipoproteins.

    PubMed

    Vilahur, Gemma; Cubedo, Judit; Padró, Teresa; Casaní, Laura; Mendieta, Guiomar; González, Alicia; Badimon, Lina

    2015-07-01

    Intake of tomatoes has been linked with healthy diets (eg, Mediterranean diet). However, it remains unknown whether tomato intake exerts protective effects on the vasculature. The aim of this study was to determine whether medium-term supplementation with cooked tomato sauce (CTS) Mediterranean style (sofrito) attenuates diet-induced coronary endothelial dysfunction in an animal model with clinical impact and explore the mechanisms behind the effects. Pigs (N = 18) were fed a 10-day hypercholesterolemic diet. Half of the animals were given a supplement of 100 g/d of CTS (21.5 mg lycopene per day). Coronary responses to escalating doses of vasoactive drugs (acetylcholine, calcium ionophore, and sodium nitroprusside) and L-NG-monomethylarginine (endothelial nitric oxide synthase [eNOS] inhibitor) were measured using flow Doppler. In the coronary arteries, we investigated eNOS gene expression and activation, monocyte chemoattractant protein 1 (MCP-1) expression, and oxidative DNA damage. In the circulation, we investigated lipoprotein resistance to oxidation and the differential proteomic protein profile. In dyslipidemic animals, CTS intake prevented diet-induced impairment of receptor-operated and nonreceptor-operated endothelial-dependent coronary vasodilation. These beneficial effects were associated with enhanced eNOS transcription and activation and diminished DNA damage in the coronary arteries. CTS-fed animals showed lower lipid peroxidation, higher high-density lipoprotein (HDL) antioxidant potential and plasma lycopene levels of 0.16 mg/L. Interestingly, improved HDL functionality was associated with protein profile changes in apolipoprotein A-I and apolipoprotein J. Lipids levels and MCP-1 expression were not affected by CTS. We report that CTS intake protects against low-density lipoprotein-induced coronary endothelial dysfunction by reducing oxidative damage, enhancing eNOS expression and activity, and improving HDL functionality. PMID:25514506

  9. Combined effects of cholesterol reduction and apolipoprotein A-I expression on atherosclerosis in LDL receptor deficient mice.

    PubMed

    Kawashiri, Masa-aki; Zhang, YuZhen; Puré, Ellen; Rader, Daniel J

    2002-11-01

    Reduction of total and LDL cholesterol reduces atherosclerosis and clinical cardiovascular events. High density lipoprotein (HDL) cholesterol levels have a strong inverse association with atherosclerosis, and overexpression of apolipoprotein A-I (apoA-I), the major protein component of HDL, reduces atherosclerosis in hypercholesterolemic animals. However, little is known about the potential for additive or synergistic effects between cholesterol reduction and apoA-I overexpression on atherosclerosis. In the current study, we tested the hypothesis that significant reduction of plasma cholesterol combined with overexpression of apoA-I would reduce atherosclerosis to a greater extent than either one alone. We used somatic gene transfer of the LDL receptor (to induce cholesterol reduction) and apoA-I in LDL receptor deficient mice fed a Western type diet and compared the combination to expression of each gene alone and to controls. Atherosclerosis was quantitated using two independent methods, by en face analysis of the entire aorta and by cross-sectional analysis of the aortic root. Although the reduction of cholesterol was transient, expression of the LDL receptor alone significantly reduced atherosclerosis by 45% in the aorta and 44% in the aortic root compared with controls. Overexpression of human apoA-I alone reduced atherosclerosis by 42% in the aorta and 44% in the aortic root compared with controls. Co-expression of the LDL receptor with apoA-I resulted in significantly higher levels of apoA-I than expression of apoA-I alone. Although co-expression of the LDL receptor and apoA-I reduced atherosclerosis by 37% in the aorta and 32% in the aortic root compared with controls, the reduction in atherosclerosis was no different than that seen with expression of the LDL receptor alone or apoA-I alone. In summary, in this relatively short-term murine model, simultaneous reduction of cholesterol and expression of apoA-I was associated with higher levels of apoA-I than

  10. Inhibition of inflammatory signaling pathways in 3T3-L1 adipocytes by apolipoprotein A-I.

    PubMed

    Sultana, Afroza; Cochran, Blake J; Tabet, Fatiha; Patel, Mili; Torres, Luisa Cuesta; Barter, Philip J; Rye, Kerry-Anne

    2016-06-01

    Activation of inflammatory signaling pathways links obesity with metabolic disorders. TLR4-mediated activation of MAPKs and NF-κB are 2 such pathways implicated in obesity-induced inflammation. Apolipoprotein A-I (apoA-I) exerts anti-inflammatory effects on adipocytes by effluxing cholesterol from the cells via the ATP binding cassette transporter A1 (ABCA1). It is not known if these effects involve inhibition of inflammatory signaling pathways by apoA-I. This study asks if apoA-I inhibits activation of MAPKs and NF-κB in mouse 3T3-L1 adipocytes and whether this inhibition is ABCA1 dependent. Incubation of differentiated 3T3-L1 adipocytes with apoA-I decreased cell surface expression of TLR4 by 16 ± 2% and synthesis of the TLR4 adaptor protein, myeloid differentiation primary response 88, by 24 ± 4% in an ABCA1-dependent manner. ApoA-I also inhibited downstream activation of MAPKs, such as ERK, p38MAPK, and JNK, as well as expression of proinflammatory adipokines in bacterial LPS-stimulated 3T3-L1 adipocytes in an ABCA1-dependent manner. ApoA-I, by contrast, suppressed nuclear localization of the p65 subunit of NF-κB by 30 ± 3% in LPS-stimulated 3T3-L1 adipocytes in an ABCA1-independent manner. In conclusion, apoA-I inhibits TLR4-mediated inflammatory signaling pathways in adipocytes by preventing MAPK and NF-κB activation.-Sultana, A., Cochran, B. J., Tabet, F., Patel, M., Cuesta Torres, L., Barter, P. J., Rye, K.-A. Inhibition of inflammatory signaling pathways in 3T3-L1 adipocytes by apolipoprotein A-I. PMID:26965683

  11. Human Frontal Lobes and AI Planning Systems

    NASA Technical Reports Server (NTRS)

    Levinson, Richard; Lum, Henry Jr. (Technical Monitor)

    1994-01-01

    Human frontal lobes are essential for maintaining a self-regulating balance between predictive and reactive behavior. This paper describes a system that integrates prediction and reaction based on neuropsychological theories of frontal lobe function. In addition to enhancing our understanding of deliberate action in humans' the model is being used to develop and evaluate the same properties in machines. First, the paper presents some background neuropsychology in order to set a general context. The role of frontal lobes is then presented by summarizing three theories which formed the basis for this work. The components of an artificial frontal lobe are then discussed from both neuropsychological and AI perspectives. The paper concludes by discussing issues and methods for evaluating systems that integrate planning and reaction.

  12. Regulation of apolipoprotein A-I gene expression in Hep G2 cells depleted of Cu by cupruretic tetramine.

    PubMed

    Wu, J Y; Zhang, J J; Wang, Y; Reaves, S K; Wang, Y R; Lei, P P; Lei, K Y

    1997-10-01

    Studies were designed to examine the regulation of apolipoprotein (apo) A-I gene expression in Cu-depleted Hep G2 cells. The cupruretic chelator N,N'-bis(2-aminoethyl)-1,3-propanediamine 4 HCl (2,3,2-tetramine or TETA) was used to maintain a 77% reduction in cellular Cu in Hep G2 cells. After two passages of TETA treatment, the relative abundance of apoA-I mRNA was elevated 52%. In TETA-treated cells, the rate of apoA-I mRNA decay measured by an actinomycin D chase study was accelerated 108%, and the synthesis of apoA-I mRNA determined by a nuclear runoff assay was enhanced 2.5-fold in TETA-treated cells. All of those changes could be reverted toward the control values with Cu supplementation for only 2 days. In transient transfection assays, a 26.7% increase in chloramphenicol O-acetyltransferase (CAT) activity for the reporter construct -256AI-CAT was observed in the treated cells. However, the ability of apoA-I regulatory protein 1 (ARP-1) to repress the CAT activity was not affected by the depressed Cu status. In addition, gel retardation experiments demonstrated that Cu depletion enhanced the binding of hepatocyte nuclear factor 4 (HNF-4) and other undefined nuclear factors to oligonucleotides containing site A, one of three regulatory sites of the apoA-I gene promoter. Moreover, the relative abundance of HNF-4 mRNA was increased 58% in the Cu-depleted cells. Thus the observed increase in apoA-I gene transcription may be mediated mostly by an elevated level of the regulatory factor, HNF-4. In summary, the present findings established the mechanism by which a depressed cellular Cu status can enhance apoA-I mRNA production and subsequently increase apoA-I synthesis. PMID:9357782

  13. Variation at the hepatic lipase and apolipoprotein AI/CIII/AIV loci is a major cause of genetically determined variation in plasma HDL cholesterol levels.

    PubMed Central

    Cohen, J C; Wang, Z; Grundy, S M; Stoesz, M R; Guerra, R

    1994-01-01

    Genetic factors have been shown to play an important role in determining interindividual variation in plasma HDL-C levels, but the specific genetic determinants of HDL cholesterol (HDL-C) levels have not been elucidated. In this study, the effects of variation in the genomic regions encoding hepatic lipase, apolipoprotein AI/CIII/AIV, and the cholesteryl ester transfer protein on plasma HDL-C levels were examined in 73 normotriglyceridemic, Caucasian nuclear families. Genetic factors accounted for 56.5 +/- 13% of the interindividual variation in plasma HDL-C levels. For each candidate gene, adjusted plasma HDL-C levels of sibling pairs who shared zero, one, or two parental alleles identical-by-descent were compared using sibling-pair linkage analysis. Allelic variation in the genes encoding hepatic lipase and apolipoprotein AI/CIII/AIV accounted for 25 and 22%, respectively, of the total interindividual variation in plasma HDL-C levels. In contrast, none of the variation in plasma HDL-C levels could be accounted for by allelic variation in the cholesteryl ester transfer protein. These findings indicate that a major fraction of the genetically determined variation in plasma HDL-C levels is conferred by allelic variation at the hepatic lipase and the apolipoprotein AI/CIII/AIV gene loci. PMID:7989594

  14. Seasonal variation in plasma lipids, lipoproteins, apolipoprotein A-I and vitellogenin in the freshwater turtle, Chrysemys picta.

    PubMed

    Duggan, A; Paolucci, M; Tercyak, A; Gigliotti, M; Small, D; Callard, I

    2001-09-01

    An analysis of plasma lipids and lipoprotein fractions was performed over the course of the annual ovarian cycle of the female turtle, Chrysemys picta. Determinations of total plasma triglycerides, cholesterol, vitellogenin and apolipoprotein A-I (apoA-I) were made. The lipid and protein composition of the lipoprotein fractions [very low density lipoprotein (VLDL), low density lipoprotein (LDL), high density lipoprotein (HDL) and very high density lipoprotein (VHDL)] were also observed over the same period. Plasma triglyceride and vitellogenin levels were significantly increased in the spring preovulatory period and fall recrudescent phase. Total plasma cholesterol levels were significantly elevated only at the onset of the fall recrudescent phase and apoA-I levels were highest during the postoviposition/ovarian arrest phase. The triglyceride content of VLDL was highest in preovulatory animals and there were apparent seasonal changes in the expression of apoA-I and apoE of HDL/VHDL. We conclude that the coordinate regulation of lipids and protein contributes to seasonal ovarian growth and clearance of lipids from plasma, both of which are most likely under hormonal control. PMID:11544071

  15. Amyloidogenic Mutation Promotes Fibril Formation of the N-terminal Apolipoprotein A-I on Lipid Membranes*

    PubMed Central

    Mizuguchi, Chiharu; Ogata, Fuka; Mikawa, Shiho; Tsuji, Kohei; Baba, Teruhiko; Shigenaga, Akira; Shimanouchi, Toshinori; Okuhira, Keiichiro; Otaka, Akira; Saito, Hiroyuki

    2015-01-01

    The N-terminal amino acid 1–83 fragment of apolipoprotein A-I (apoA-I) has a strong propensity to form amyloid fibrils at physiological neutral pH. Because apoA-I has an ability to bind to lipid membranes, we examined the effects of the lipid environment on fibril-forming properties of the N-terminal fragment of apoA-I variants. Thioflavin T fluorescence assay as well as fluorescence and transmission microscopies revealed that upon lipid binding, fibril formation by apoA-I 1–83 is strongly inhibited, whereas the G26R mutant still retains the ability to form fibrils. Such distinct effects of lipid binding on fibril formation were also observed for the amyloidogenic prone region-containing peptides, apoA-I 8–33 and 8–33/G26R. This amyloidogenic region shifts from random coil to α-helical structure upon lipid binding. The G26R mutation appears to prevent this helix transition because lower helical propensity and more solvent-exposed conformation of the G26R variant upon lipid binding were observed in the apoA-I 1–83 fragment and 8–33 peptide. With a partially α-helical conformation induced by the presence of 2,2,2-trifluoroethanol, fibril formation by apoA-I 1–83 was strongly inhibited, whereas the G26R variant can form amyloid fibrils. These findings suggest a new possible pathway for amyloid fibril formation by the N-terminal fragment of apoA-I variants: the amyloidogenic mutations partially destabilize the α-helical structure formed upon association with lipid membranes, resulting in physiologically relevant conformations that allow fibril formation. PMID:26175149

  16. Decreased apolipoprotein A-I level indicates poor prognosis in extranodal natural killer/T-cell lymphoma, nasal type

    PubMed Central

    Quan, Qi; Chen, Qi; Chen, Ping; Jiang, Li; Li, Tingwei; Qiu, Huijuan; Zhang, Bei

    2016-01-01

    Background Extranodal natural killer (NK)/T-cell lymphoma, nasal type (ENKTL) is an invasive lymphoid malignancy with unfavorable survival, for which a prognostic model has not yet been validated. We hypothesized that serum apolipoprotein A-I (ApoA-I) may serve as a novel prognostic marker for ENKTL. Patients and methods A total of 236 newly diagnosed cases of ENKTL were analyzed retrospectively. Results The optimal cutoff value for the serum ApoA-I level was determined to be 0.95 g/L. A total of 154 and 82 cases were assigned to the high and low ApoA-I groups, respectively. Patients in the low ApoA-I group tended to present with poorer clinical features, a lower complete remission rate (P=0.001), and poor median progression-free survival (P<0.001) and overall survival (P<0.001). Multivariate analysis using Cox model showed that the serum ApoA-I level was an independent prognostic marker of overall survival (P<0.001) and progression-free survival (P<0.001) for ENKTL patients. For cases in the low-risk group, as assessed by International Prognostic Index, Prognosis Index for peripheral T-cell lymphoma, unspecified, and Korean Prognostic Index, the serum ApoA-I level was able to differentiate cases with poor outcomes from cases with good outcomes. Conclusion Our results showed that the baseline serum ApoA-I level was helpful for predicting ENKTL prognosis. PMID:27051293

  17. Mycoplasma gallisepticum (HS strain) surface lipoprotein pMGA interacts with host apolipoprotein A-I during infection in chicken.

    PubMed

    Hu, Fuli; Zhao, Chengcheng; Bi, Dingren; Tian, Wei; Chen, Jiao; Sun, Jianjun; Peng, Xiuli

    2016-02-01

    The adhesin protein from Mycoplasma gallisepticum (HS strain), namely pMGA1.2, is required for M. gallisepticum (MG) infection in chicken. However, the host factor(s) that interact with pMGA1.2 is not known. In this study, we prepared the membrane fraction of trachea epithelial cells from chicken embryos. Using an improved virus overlay protein blot assay (VOPBA) and glutathione S-transferase (GST) pull-down assay, we found that pMGA1.2 specifically bound to a ∼30 kDa host protein. This host protein was further identified by mass spectrometry as chicken apolipoprotein A-I (ApoA-I). We expressed and purified the recombinant ApoA-I protein in Escherichia coli and confirmed that it bound to the purified pMGA1.2 protein in vitro. Transiently expressed pMGA1.2 and ApoA-I were colocalized in HeLa cells. Finally, we designed small interfering RNA (siRNA) molecules to knock down the expression of either ApoA-I or pMGA1.2, which inhibited the MG-induced cell cycle disruption in cells of chicken embryo fibroblast cell line (DF-1). Similarly, knockdown of ApoA-I inhibited the cilia loss and damage in chicken trachea cells in MG infection. In summary, ApoA-I may be an essential host factor in MG infection through interacting with pMGA1.2. PMID:26549235

  18. The A's Have It: Developing Apolipoprotein A-I Mimetic Peptides Into a Novel Treatment for Asthma.

    PubMed

    Yao, Xianglan; Gordon, Elizabeth M; Barochia, Amisha V; Remaley, Alan T; Levine, Stewart J

    2016-08-01

    New treatments are needed for patients with asthma who are refractory to standard therapies, such as individuals with a phenotype of "type 2-low" inflammation. This important clinical problem could potentially be addressed by the development of apolipoprotein A-I (apoA-I) mimetic peptides. ApoA-I interacts with its cellular receptor, the ATP-binding cassette subfamily A, member 1 (ABCA1), to facilitate cholesterol efflux out of cells to form nascent high-density lipoprotein particles. The ability of the apoA-I/ABCA1 pathway to promote cholesterol efflux from cells that mediate adaptive immunity, such as antigen-presenting cells, can attenuate their function. Data from experimental murine models have shown that the apoA-I/ABCA1 pathway can reduce neutrophilic airway inflammation, primarily by suppressing the production of granulocyte-colony stimulating factor. Furthermore, administration of apoA-I mimetic peptides to experimental murine models of allergic asthma has decreased both neutrophilic and eosinophilic airway inflammation, as well as airway hyperresponsiveness and mucous cell metaplasia. Higher serum levels of apoA-I have also been associated with less severe airflow obstruction in patients with asthma. Collectively, these results suggest that the apoA-I/ABCA1 pathway may have a protective effect in asthma, and support the concept of advancing inhaled apoA-I mimetic peptides to clinical trials that can assess their safety and effectiveness. Thus, we propose that the development of inhaled apoA-I mimetic peptides as a new treatment could represent a clinical advance for patients with severe asthma who are unresponsive to other therapies. PMID:27327118

  19. Amyloidogenic Mutation Promotes Fibril Formation of the N-terminal Apolipoprotein A-I on Lipid Membranes.

    PubMed

    Mizuguchi, Chiharu; Ogata, Fuka; Mikawa, Shiho; Tsuji, Kohei; Baba, Teruhiko; Shigenaga, Akira; Shimanouchi, Toshinori; Okuhira, Keiichiro; Otaka, Akira; Saito, Hiroyuki

    2015-08-21

    The N-terminal amino acid 1-83 fragment of apolipoprotein A-I (apoA-I) has a strong propensity to form amyloid fibrils at physiological neutral pH. Because apoA-I has an ability to bind to lipid membranes, we examined the effects of the lipid environment on fibril-forming properties of the N-terminal fragment of apoA-I variants. Thioflavin T fluorescence assay as well as fluorescence and transmission microscopies revealed that upon lipid binding, fibril formation by apoA-I 1-83 is strongly inhibited, whereas the G26R mutant still retains the ability to form fibrils. Such distinct effects of lipid binding on fibril formation were also observed for the amyloidogenic prone region-containing peptides, apoA-I 8-33 and 8-33/G26R. This amyloidogenic region shifts from random coil to α-helical structure upon lipid binding. The G26R mutation appears to prevent this helix transition because lower helical propensity and more solvent-exposed conformation of the G26R variant upon lipid binding were observed in the apoA-I 1-83 fragment and 8-33 peptide. With a partially α-helical conformation induced by the presence of 2,2,2-trifluoroethanol, fibril formation by apoA-I 1-83 was strongly inhibited, whereas the G26R variant can form amyloid fibrils. These findings suggest a new possible pathway for amyloid fibril formation by the N-terminal fragment of apoA-I variants: the amyloidogenic mutations partially destabilize the α-helical structure formed upon association with lipid membranes, resulting in physiologically relevant conformations that allow fibril formation. PMID:26175149

  20. Genome-wide screen for modulation of hepatic apolipoprotein A-I (ApoA-I) secretion.

    PubMed

    Miles, Rebecca R; Perry, William; Haas, Joseph V; Mosior, Marian K; N'Cho, Mathias; Wang, Jian W J; Yu, Peng; Calley, John; Yue, Yong; Carter, Quincy; Han, Bomie; Foxworthy, Patricia; Kowala, Mark C; Ryan, Timothy P; Solenberg, Patricia J; Michael, Laura F

    2013-03-01

    Control of plasma cholesterol levels is a major therapeutic strategy for management of coronary artery disease (CAD). Although reducing LDL cholesterol (LDL-c) levels decreases morbidity and mortality, this therapeutic intervention only translates into a 25-40% reduction in cardiovascular events. Epidemiological studies have shown that a high LDL-c level is not the only risk factor for CAD; low HDL cholesterol (HDL-c) is an independent risk factor for CAD. Apolipoprotein A-I (ApoA-I) is the major protein component of HDL-c that mediates reverse cholesterol transport from tissues to the liver for excretion. Therefore, increasing ApoA-I levels is an attractive strategy for HDL-c elevation. Using genome-wide siRNA screening, targets that regulate hepatocyte ApoA-I secretion were identified through transfection of 21,789 siRNAs into hepatocytes whereby cell supernatants were assayed for ApoA-I. Approximately 800 genes were identified and triaged using a convergence of information, including genetic associations with HDL-c levels, tissue-specific gene expression, druggability assessments, and pathway analysis. Fifty-nine genes were selected for reconfirmation; 40 genes were confirmed. Here we describe the siRNA screening strategy, assay implementation and validation, data triaging, and example genes of interest. The genes of interest include known and novel genes encoding secreted enzymes, proteases, G-protein-coupled receptors, metabolic enzymes, ion transporters, and proteins of unknown function. Repression of farnesyltransferase (FNTA) by siRNA and the enzyme inhibitor manumycin A caused elevation of ApoA-I secretion from hepatocytes and from transgenic mice expressing hApoA-I and cholesterol ester transfer protein transgenes. In total, this work underscores the power of functional genetic assessment to identify new therapeutic targets. PMID:23322769

  1. PPARγ Represses Apolipoprotein A-I Gene but Impedes TNFα-Mediated ApoA-I Downregulation in HepG2 Cells.

    PubMed

    Shavva, Vladimir S; Mogilenko, Denis A; Bogomolova, Alexandra M; Nikitin, Artemy A; Dizhe, Ella B; Efremov, Alexander M; Oleinikova, Galina N; Perevozchikov, Andrej P; Orlov, Sergey V

    2016-09-01

    Apolipoprotein A-I (ApoA-I) is the main anti-atherogenic component of human high-density lipoproteins (HDL). ApoA-I gene expression is regulated by several nuclear receptors, which are the sensors for metabolic changes during development of cardiovascular diseases. Activation of nuclear receptor PPARγ has been shown to impact lipid metabolism as well as inflammation. Here, we have shown that synthetic PPARγ agonist GW1929 decreases both ApoA-I mRNA and protein levels in HepG2 cells and the effect of GW1929 on apoA-I gene transcription depends on PPARγ. PPARγ binds to the sites A and C within the hepatic enhancer of apoA-I gene and the negative regulation of apoA-I gene transcription by PPARγ appears to be realized via the site C (-134 to -119). Ligand activation of PPARγ leads to an increase of LXRβ and a decrease of PPARα binding to the apoA-I gene hepatic enhancer in HepG2 cells. GW1929 abolishes the TNFα-mediated decrease of ApoA-I mRNA expression in both HepG2 and Caco-2 cells but does not block TNFα-mediated inhibition of ApoA-I protein secretion by HepG2 cells. These data demonstrate that complex of PPARγ with GW1929 is a negative regulator involved in the control of ApoA-I expression and secretion in human hepatocyte- and enterocyte-like cells. J. Cell. Biochem. 117: 2010-2022, 2016. © 2016 Wiley Periodicals, Inc. PMID:26813964

  2. Gender and age specific differences in the kinetic behavior of TRL, IDL and LDL apolipoprotein B-100 and HDL apolipoprotein A-I

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Gender specific differences in lipid and lipoprotein profile, predominantly higher LDL-C, VLDL-C and TG, and lower HDL-C levels have been observed in males compared to females. These differences are influenced by menopausal status and age. To investigate mechanism(s) involved, apolipoprotein (apo) B...

  3. Apolipoprotein A-I mimetic peptide 4F blocks sphingomyelinase-induced LDL aggregation[S

    PubMed Central

    Nguyen, Su Duy; Javanainen, Matti; Rissanen, Sami; Zhao, Hongxia; Huusko, Jenni; Kivelä, Annukka M.; Ylä-Herttuala, Seppo; Navab, Mohamad; Fogelman, Alan M.; Vattulainen, Ilpo; Kovanen, Petri T.; Öörni, Katariina

    2015-01-01

    Lipolytic modification of LDL particles by SMase generates LDL aggregates with a strong affinity for human arterial proteoglycans and may so enhance LDL retention in the arterial wall. Here, we evaluated the effects of apoA-I mimetic peptide 4F on structural and functional properties of the SMase-modified LDL particles. LDL particles with and without 4F were incubated with SMase, after which their aggregation, structure, and proteoglycan binding were analyzed. At a molar ratio of L-4F to apoB-100 of 2.5 to 20:1, 4F dose-dependently inhibited SMase-induced LDL aggregation. At a molar ratio of 20:1, SMase-induced aggregation was fully blocked. Binding of 4F to LDL particles inhibited SMase-induced hydrolysis of LDL by 10% and prevented SMase-induced LDL aggregation. In addition, the binding of the SMase-modified LDL particles to human aortic proteoglycans was dose-dependently inhibited by pretreating LDL with 4F. The 4F stabilized apoB-100 conformation and inhibited SMase-induced conformational changes of apoB-100. Molecular dynamic simulations showed that upon binding to protein-free LDL surface, 4F locally alters membrane order and fluidity and induces structural changes to the lipid layer. Collectively, 4F stabilizes LDL particles by preventing the SMase-induced conformational changes in apoB-100 and so blocks SMase-induced LDL aggregation and the resulting increase in LDL retention. PMID:25861792

  4. Effect of apolipoprotein a-I complex with tetrahydrocortisone on protein biosynthesis and glucose absorption by rat hepatocytes.

    PubMed

    Sumenkova, D V; Knyazev, R A; Guschya, R S; Polyakov, L M; Panin, L E

    2009-08-01

    We studied the effect of apolipoprotein A-I-tetrahydrocortisone complex on (14)C glucose absorption and lactate accumulation and on the rate of protein biosynthesis in isolated rat hepatocytes. The presence of apolipoprotein A-I-tetrahydrocortisone complex in the incubation medium increased absorption of labeled glucose by hepatocytes by 52%, while lactate content in the conditioning medium increased 4-fold. The rate of protein biosynthesis increased by 80% in comparison with control cells. It is hypothesized that the increase in protein biosynthesis rate in hepatocytes under the effect of apolipoprotein A-I-tetrahydrocortisone complex is due to stimulation of energy metabolism, specifically, of its glycolytic component. PMID:20027330

  5. Anti-CD20 single chain variable antibody fragment–apolipoprotein A-I chimera containing nanodisks promote targeted bioactive agent delivery to CD20-positive lymphomas

    PubMed Central

    Crosby, Natasha M.; Ghosh, Mistuni; Su, Betty; Beckstead, Jennifer A.; Kamei, Ayako; Simonsen, Jens B.; Luo, Bing; Gordon, Leo I.; Forte, Trudy M.; Ryan, Robert O.

    2015-01-01

    A fusion protein comprising an α-CD20 single chain variable fragment (scFv) antibody, a spacer peptide, and human apolipoprotein (apo) A-I was constructed and expressed in Escherichia coli. The lipid interaction properties intrinsic to apoA-I as well as the antigen recognition properties of the scFv were retained by the chimera. scFv•apoA-I was formulated into nanoscale reconstituted high-density lipoprotein particles (termed nanodisks; ND) and incubated with cultured cells. α-CD20 scFv•apoA-I ND bound to CD20-positive non-Hodgkins lymphoma (NHL) cells (Ramos and Granta) but not to CD20-negative T lymphocytes (i.e., Jurkat). Binding to NHL cells was partially inhibited by pre-incubation with rituximab, a monoclonal antibody directed against CD20. Confocal fluorescence microscopy analysis of Granta cells following incubation with α-CD20 scFv•apoA-I ND formulated with the intrinsically fluorescent hydrophobic polyphenol, curcumin, revealed α-CD20 scFv•apoA-I localizes to the cell surface, while curcumin off-loads and gains entry to the cell. Compared to control incubations, viability of cultured NHL cells was decreased upon incubation with α-CD20 scFv•apoA-I ND harboring curcumin. Thus, formulation of curcumin ND with α-CD20 scFv•apoA-I as the scaffold component confers cell targeting and enhanced bioactive agent delivery, providing a strategy to minimize toxicity associated with chemotherapeutic agents. PMID:25994015

  6. Apolipoprotein A-I helical structure and stability in discoidal high-density lipoprotein (HDL) particles by hydrogen exchange and mass spectrometry.

    PubMed

    Sevugan Chetty, Palaniappan; Mayne, Leland; Kan, Zhong-Yuan; Lund-Katz, Sissel; Englander, S Walter; Phillips, Michael C

    2012-07-17

    To understand high-density lipoprotein (HDL) structure at the molecular level, the location and stability of α-helical segments in human apolipoprotein (apo) A-I in large (9.6 nm) and small (7.8 nm) discoidal HDL particles were determined by hydrogen-deuterium exchange (HX) and mass spectrometry methods. The measured HX kinetics of some 100 apoA-I peptides specify, at close to amino acid resolution, the structural condition of segments throughout the protein sequence and changes in structure and stability that occur on incorporation into lipoprotein particles. When incorporated into the large HDL particle, the nonhelical regions in lipid-free apoA-I (residues 45-53, 66-69, 116-146, and 179-236) change conformation from random coil to α-helix so that nearly the entire apoA-I molecule adopts helical structure (except for the terminal residues 1-6 and 237-243). The amphipathic α-helices have relatively low stability, in the range 3-5 kcal/mol, indicating high flexibility and dynamic unfolding and refolding in seconds or less. A segment encompassed by residues 125-158 exhibits bimodal HX labeling indicating co-existing helical and disordered loop conformations that interchange on a time scale of minutes. When incorporated around the edge of the smaller HDL particle, the increase in packing density of the two apoA-I molecules forces about 20% more residues out of direct contact with the phospholipid molecules to form disordered loops, and these are the same segments that form loops in the lipid-free state. The region of disc-associated apoA-I that binds the lecithin-cholesterol acyltransferase enzyme is well structured and not a protruding unstructured loop as reported by others. PMID:22745166

  7. Anti-CD20 single chain variable antibody fragment-apolipoprotein A-I chimera containing nanodisks promote targeted bioactive agent delivery to CD20-positive lymphomas.

    PubMed

    Crosby, Natasha M; Ghosh, Mistuni; Su, Betty; Beckstead, Jennifer A; Kamei, Ayako; Simonsen, Jens B; Luo, Bing; Gordon, Leo I; Forte, Trudy M; Ryan, Robert O

    2015-08-01

    A fusion protein comprising an α-CD20 single chain variable fragment (scFv) antibody, a spacer peptide, and human apolipoprotein (apo) A-I was constructed and expressed in Escherichia coli. The lipid interaction properties intrinsic to apoA-I as well as the antigen recognition properties of the scFv were retained by the chimera. scFv•apoA-I was formulated into nanoscale reconstituted high-density lipoprotein particles (termed nanodisks; ND) and incubated with cultured cells. α-CD20 scFv•apoA-I ND bound to CD20-positive non-Hodgkins lymphoma (NHL) cells (Ramos and Granta) but not to CD20-negative T lymphocytes (i.e., Jurkat). Binding to NHL cells was partially inhibited by pre-incubation with rituximab, a monoclonal antibody directed against CD20. Confocal fluorescence microscopy analysis of Granta cells following incubation with α-CD20 scFv•apoA-I ND formulated with the intrinsically fluorescent hydrophobic polyphenol, curcumin, revealed α-CD20 scFv•apoA-I localizes to the cell surface, while curcumin off-loads and gains entry to the cell. Compared to control incubations, viability of cultured NHL cells was decreased upon incubation with α-CD20 scFv•apoA-I ND harboring curcumin. Thus, formulation of curcumin ND with α-CD20 scFv•apoA-I as the scaffold component confers cell targeting and enhanced bioactive agent delivery, providing a strategy to minimize toxicity associated with chemotherapeutic agents. PMID:25994015

  8. Apolipoprotein A-I Deficiency Increases Cerebral Amyloid Angiopathy and Cognitive Deficits in APP/PS1ΔE9 Mice*

    PubMed Central

    Lefterov, Iliya; Fitz, Nicholas F.; Cronican, Andrea A.; Fogg, Allison; Lefterov, Preslav; Kodali, Ravindra; Wetzel, Ronald; Koldamova, Radosveta

    2010-01-01

    A hallmark of Alzheimer disease (AD) is the deposition of amyloid β (Aβ) in brain parenchyma and cerebral blood vessels, accompanied by cognitive decline. Previously, we showed that human apolipoprotein A-I (apoA-I) decreases Aβ40 aggregation and toxicity. Here we demonstrate that apoA-I in lipidated or non-lipidated form prevents the formation of high molecular weight aggregates of Aβ42 and decreases Aβ42 toxicity in primary brain cells. To determine the effects of apoA-I on AD phenotype in vivo, we crossed APP/PS1ΔE9 to apoA-IKO mice. Using a Morris water maze, we demonstrate that the deletion of mouse Apoa-I exacerbates memory deficits in APP/PS1ΔE9 mice. Further characterization of APP/PS1ΔE9/apoA-IKO mice showed that apoA-I deficiency did not affect amyloid precursor protein processing, soluble Aβ oligomer levels, Aβ plaque load, or levels of insoluble Aβ in brain parenchyma. To examine the effect of Apoa-I deletion on cerebral amyloid angiopathy, we measured insoluble Aβ isolated from cerebral blood vessels. Our data show that in APP/PS1ΔE9/apoA-IKO mice, insoluble Aβ40 is increased more than 10-fold, and Aβ42 is increased 1.5-fold. The increased levels of deposited amyloid in the vessels of cortices and hippocampi of APP/PS1ΔE9/apoA-IKO mice, measured by X-34 staining, confirmed the results. Finally, we demonstrate that lipidated and non-lipidated apoA-I significantly decreased Aβ toxicity against brain vascular smooth muscle cells. We conclude that lack of apoA-I aggravates the memory deficits in APP/PS1ΔE9 mice in parallel to significantly increased cerebral amyloid angiopathy. PMID:20739292

  9. Folded Functional Lipid-Poor Apolipoprotein A-I Obtained by Heating of High-Density Lipoproteins: Relevance to HDL Biogenesis

    PubMed Central

    Jayaraman, Shobini; Cavigiolio, Giorgio; Gursky, Olga

    2013-01-01

    Synopsis High-density lipoproteins (HDL) remove cell cholesterol and protect from atherosclerosis. The major HDL protein is apolipoprotein A-I (apoA-I). Most plasma apoA-I circulates in lipoproteins, yet ~5% forms monomeric lipid-poor/free species. This metabolically active species is a primary cholesterol acceptor and is central to HDL biogenesis. Structural properties of lipid-poor apoA-I are unclear due to difficulties in isolating this transient species. We used thermal denaturation of human HDL to produce lipid-poor apoA-I. Analysis of the isolated lipid-poor fraction showed protein:lipid weight ratio 3:1, with apoA-I, phosphatidylcholine and cholesterol ester at approximate molar ratios of 1:8:1. Compared to lipid-free apoA-I, lipid-poor apoA-I showed slightly altered secondary structure and aromatic packing, reduced thermodynamic stability, lower self-associating propensity, increased adsorption to phospholipid surface, and comparable ability to remodel phospholipids and form reconstituted HDL. Lipid-poor apoA-I can be formed by heating of either plasma or reconstituted HDL. We propose the first structural model of lipid-poor apoA-I which corroborates its distinct biophysical properties and postulates the lipid-induced ordering of the labile C-terminal region. In summary, HDL heating produces folded functional monomolecular lipid-poor apoA-I that is distinct from lipid-free apoA-I. Increased adsorption to phospholipid surface and reduced C-terminal disorder may help direct lipid-poor apoA-I towards HDL biogenesis. PMID:22150513

  10. Folded functional lipid-poor apolipoprotein A-I obtained by heating of high-density lipoproteins: relevance to high-density lipoprotein biogenesis.

    PubMed

    Jayaraman, Shobini; Cavigiolio, Giorgio; Gursky, Olga

    2012-03-15

    HDL (high-density lipoproteins) remove cell cholesterol and protect from atherosclerosis. The major HDL protein is apoA-I (apolipoprotein A-I). Most plasma apoA-I circulates in lipoproteins, yet ~5% forms monomeric lipid-poor/free species. This metabolically active species is a primary cholesterol acceptor and is central to HDL biogenesis. Structural properties of lipid-poor apoA-I are unclear due to difficulties in isolating this transient species. We used thermal denaturation of human HDL to produce lipid-poor apoA-I. Analysis of the isolated lipid-poor fraction showed a protein/lipid weight ratio of 3:1, with apoA-I, PC (phosphatidylcholine) and CE (cholesterol ester) at approximate molar ratios of 1:8:1. Compared with lipid-free apoA-I, lipid-poor apoA-I showed slightly altered secondary structure and aromatic packing, reduced thermodynamic stability, lower self-associating propensity, increased adsorption to phospholipid surface and comparable ability to remodel phospholipids and form reconstituted HDL. Lipid-poor apoA-I can be formed by heating of either plasma or reconstituted HDL. We propose the first structural model of lipid-poor apoA-I which corroborates its distinct biophysical properties and postulates the lipid-induced ordering of the labile C-terminal region. In summary, HDL heating produces folded functional monomolecular lipid-poor apoA-I that is distinct from lipid-free apoA-I. Increased adsorption to phospholipid surface and reduced C-terminal disorder may help direct lipid-poor apoA-I towards HDL biogenesis. PMID:22150513

  11. Apolipoprotein A-I possesses an anti-obesity effect associated with increase of energy expenditure and up-regulation of UCP1 in brown fat

    PubMed Central

    Ruan, Xiangbo; Li, Zhenghu; Zhang, Yixuan; Yang, Ling; Pan, Yi; Wang, Zhenzhen; Feng, Gen-Sheng; Chen, Yan

    2011-01-01

    Abstract Apolipoprotein A-I (ApoA-I) is the most abundant protein constituent of high-density lipoprotein (HDL). Reduced plasma HDL and ApoA-I levels have been found to be associated with obesity and metabolic syndrome in human beings. However, whether or not ApoA-I has a direct effect on obesity is largely unknown. Here we analysed the anti-obesity effect of ApoA-I using two mouse models, a transgenic mouse with overexpression of ApoA-I and the mice administered with an ApoA-I mimetic peptide D-4F. The mice were induced to develop obesity by feeding with high fat diet. Both ApoA-I overexpression and D-4F treatment could significantly reduce white fat mass and slightly improve insulin sensitivity in the mice. Metabolic analyses revealed that ApoA-I overexpression and D-4F treatment enhanced energy expenditure in the mice. The mRNA level of uncoupling protein (UCP)1 in brown fat tissue was elevated by ApoA-I transgenic mice. ApoA-I and D-4F treatment was able to increase UCP1 mRNA and protein levels as well as to stimulate AMP-activated protein kinase (AMPK) phosphorylation in brown adipocytes in culture. Taken together, our results reveal that ApoA-I has an anti-obesity effect in the mouse and such effect is associated with increases in energy expenditure and UCP1 expression in the brown fat tissue. PMID:20193037

  12. Haptoglobin binding to apolipoprotein A-I prevents damage from hydroxyl radicals on its stimulatory activity of the enzyme lecithin-cholesterol acyl-transferase.

    PubMed

    Salvatore, Alfonso; Cigliano, Luisa; Bucci, Enrico M; Corpillo, Davide; Velasco, Silvia; Carlucci, Alessandro; Pedone, Carlo; Abrescia, Paolo

    2007-10-01

    Apolipoprotein A-I (ApoA-I), a major component of HDL, binds haptoglobin, a plasma protein transporting to liver or macrophages free Hb for preventing hydroxyl radical production. This work aimed to assess whether haptoglobin protects ApoA-I against this radical. Human ApoA-I structure, as analyzed by electrophoresis and MS, was found severely altered by hydroxyl radicals in vitro. Lower alteration of ApoA-I was found when HDL was oxidized in the presence of haptoglobin. ApoA-I oxidation was limited also when the complex of haptoglobin with both high-density lipoprotein and Hb, immobilized on resin beads, was exposed to hydroxyl radicals. ApoA-I function to stimulate cholesterol esterification was assayed in vitro by using ApoA-I-containing liposomes. Decreased stimulation was observed when liposomes oxidized without haptoglobin were used. Conversely, after oxidative stress in the presence of haptoglobin (0.5 microM monomer), the liposome activity did not change. Plasma of carrageenan-treated mice was analyzed by ELISA for the levels of haptoglobin and ApoA-I, and used to isolate HDL for MS analysis. Hydroxyproline-containing fragments of ApoA-I were found associated with low levels of haptoglobin (18 microM monomer), whereas they were not detected when the haptoglobin level increased (34-70 microM monomer). Therefore haptoglobin, when circulating at enhanced levels with free Hb during the acute phase of inflammation, might protect ApoA-I structure and function against hydroxyl radicals. PMID:17824618

  13. [Discovery and crystallographic structure of human apolipoprotein].

    PubMed

    Morales, R; Berna, A; Carpentier, P; Contreras-Martel, C; Renault, F; Nicodeme, M; Chesne-Seck, M-L; Bernier, F; Dupuy, J; Schaeffer, C; Diemer, H; Van-Dorsselaer, A; Fontecilla-Camps, J C; Masson, P; Rochu, D; Chabrière, E

    2007-03-01

    We report the serendipitous discovery of a human plasma phosphate binding protein (HPBP). This 38 kDa protein is co-purified with paraoxonase (PON1). The association between HPON1 and HPBP is modulated by phosphate and calcium concentrations. The HPBP X-ray structure solved at 1.9 A resolution is similar to the prokaryotic phosphate solute-binding proteins (SBPs) associated with ATP binding cassette transmembrane transporters, though phosphate-SBPs have never been characterized or predicted from nucleic acid databases in eukaryotes. However, HPBP belongs to the family of ubiquitous eukaryotic proteins named DING, meaning that phosphate-SBPs are also widespread in eukaryotes. The absence of complete genes for eukaryotic phosphate-SBP from databases is intriguing, but the astonishing 90% sequence conservation of genes between evolutionary distant species suggests that the corresponding proteins play an important function. HPBP is the first identified transporter capable of binding phosphate ions in human plasma. Thus it is thought to become a new predictor and a potential therapeutic agent for phosphate-related diseases such as atherosclerosis. PMID:17404543

  14. Effects of the Iowa and Milano mutations on apolipoprotein A-I structure and dynamics determined by hydrogen exchange and mass spectrometry.

    PubMed

    Chetty, Palaniappan Sevugan; Ohshiro, Maki; Saito, Hiroyuki; Dhanasekaran, Padmaja; Lund-Katz, Sissel; Mayne, Leland; Englander, Walter; Phillips, Michael C

    2012-11-01

    The Iowa point mutation in apolipoprotein A-I (G26R) leads to a systemic amyloidosis condition, and the Milano mutation (R173C) is associated with hypoalphalipoproteinemia, a reduced plasma level of high-density lipoprotein. To probe the structural effects that lead to these outcomes, we used amide hydrogen-deuterium exchange coupled with a fragment separation/mass spectrometry analysis (HX MS). The Iowa mutation inserts an arginine residue into the nonpolar face of an α-helix that spans residues 7-44 and causes changes in structure and structural dynamics. This helix unfolds, and other helices in the N-terminal helix bundle domain are destabilized. The segment encompassing residues 116-158, largely unstructured in wild-type apolipoprotein A-I, becomes helical. The helix spanning residues 81-115 is destabilized by 2 kcal/mol, increasing the small fraction of time it is transiently unfolded to ≥1%, which allows proteolysis at residue 83 in vivo over time, releasing an amyloid-forming peptide. The Milano mutation situated on the polar face of the helix spanning residues 147-178 destabilizes the helix bundle domain only moderately, but enough to allow cysteine-mediated dimerization that leads to the altered functionality of this variant. These results show how the HX MS approach can provide a powerful means of monitoring, in a nonperturbing way and at close to amino acid resolution, the structural, dynamic, and energetic consequences of biologically interesting point mutations. PMID:23066790

  15. Composition, structure and substrate properties of reconstituted discoidal HDL with apolipoprotein A-I and cholesteryl ester

    NASA Astrophysics Data System (ADS)

    Dergunov, Alexander D.; Shabrova, Elena V.; Dobretsov, Gennady E.

    2010-03-01

    To investigate the influence of lipid unsaturation and neutral lipid on the maturation of high density lipoproteins, the discoidal complexes of apoA-I, phosphatidylcholine and cholesteryl ester (CE) were prepared. Saturated dipalmitoylphosphatidylcholine (DPPC) and unsaturated palmitoyllinoleoylphosphatidylcholine (PLPC), palmitoyloleoylphosphatidylcholine (POPC), and fluorescent probe cholesteryl 1-pyrenedecanoate (CPD) that forms in a diffusion- and concentration-dependent manner short-lived dimer of unexcited and excited molecules (excimer) were used. The apoA-I/DPPC/CPD complexes were heterogeneous by size, composition and probe location. CPD molecules incorporated more efficiently into larger complexes and accumulated in a central part of the discs. The apoA-I/POPC(PLPC)/CPD were also heterogeneous, however, probe molecules distributed preferentially into smaller complexes and accumulated at disc periphery. The kinetics of CPD transfer by recombinant cholesteryl ester transfer protein (CETP) to human plasma LDL is well described by two-exponential decay, the fast component with a shorter transfer time being more populated in PLPC compared to DPPC complexes. The presence of CE molecules in discoidal HDL results in particle heterogeneity. ApoA-I influences the CETP activity modulating the properties of apolipoprotein-phospholipid interface. This may include CE molecules accumulation in the boundary lipid in unsaturated phosphatidylcholine and cluster formation in the bulk bilayer in saturated phosphatidylcholine.

  16. Phylogenetic distribution of apolipoproteins A-I and E in vertebrates as determined by Western blot analysis.

    PubMed

    Duggan, A E; Callard, I P

    2001-08-01

    A putative apolipoprotein E (apoE) has been identified in the HDL and VHDL fractions of the turtle. This observation is of particular interest considering apoE has been reported absent in the domestic hen (Hermier et al., '95; Biochim Biophys Acta: 105-118, 1995) and thus presumed absent in nonmammalian vertebrates altogether. As a result, partial amino acid sequencing of this protein was performed and revealed that one fragment shared 41% sequence identity to human apoE. Western blot analysis using antisera to apoE demonstrated cross-reactivity to a 34-kDa protein (putative apoE) in turtle plasma. Further investigation using anti-apoE antibody in Western blot analysis detected immunoreactive apoE in the plasma of lamprey, spiny dogfish, skate, and alligator, but not in flounder, newt or python; its absence in several species of birds was confirmed. Using anti-apoA-I antibody, apoA-I was detected in all vertebrate groups except a representative teleost (flounder). Apo-A-I antibody cross-reacted weakly with some putative apoE proteins (chicken, spiny dogfish and skate) and the reverse was true for anti-apoE, which cross-reacted with putative apoA-I in birds, reptiles, and elasmobranchs, confirming the molecular similarity and phylogenetic relatedness of these two proteins. PMID:11479905

  17. Anti-inflammatory mechanisms of apolipoprotein A-I mimetic peptide in acute respiratory distress syndrome secondary to sepsis.

    PubMed

    Sharifov, Oleg F; Xu, Xin; Gaggar, Amit; Grizzle, William E; Mishra, Vinod K; Honavar, Jaideep; Litovsky, Silvio H; Palgunachari, Mayakonda N; White, C Roger; Anantharamaiah, G M; Gupta, Himanshu

    2013-01-01

    Acute respiratory distress syndrome (ARDS) due to sepsis has a high mortality rate with limited treatment options. High density lipoprotein (HDL) exerts innate protective effects in systemic inflammation. However, its role in ARDS has not been well studied. Peptides such as L-4F mimic the secondary structural features and functions of apolipoprotein (apo)A-I, the major protein component of HDL. We set out to measure changes in HDL in sepsis-mediated ARDS patients, and to study the potential of L-4F to prevent sepsis-mediated ARDS in a rodent model of lipopolysaccharide (LPS)-mediated acute lung injury, and a combination of primary human leukocytes and human ARDS serum. We also analyzed serum from non-lung disease intubated patients (controls) and sepsis-mediated ARDS patients. Compared to controls, ARDS demonstrates increased serum endotoxin and IL-6 levels, and decreased HDL, apoA-I and activity of anti-oxidant HDL-associated paraoxanase-1. L-4F inhibits the activation of isolated human leukocytes and neutrophils by ARDS serum and LPS in vitro. Further, L-4F decreased endotoxin activity and preserved anti-oxidant properties of HDL both in vitro and in vivo. In a rat model of severe endotoxemia, L-4F significantly decreased mortality and reduces lung and liver injury, even when administered 1 hour post LPS. Our study suggests the protective role of the apoA-I mimetic peptide L-4F in ARDS and gram-negative endotoxemia and warrant further clinical evaluation. The main protective mechanisms of L-4F are due to direct inhibition of endotoxin activity and preservation of HDL anti-oxidant activity. PMID:23691230

  18. A critical evaluation of the proposal that serum apolipoproteins are the major constituents of the human erythrocyte membrane.

    PubMed

    Carey, C; Wang, C S; Alaupovic, P

    1975-08-01

    1. The EDTA and Triton X-100 extracts of human erythrocyte ghosts gave no precipitin lines in double diffusion analyses with antibodies to either lipoprotein A, lipoprotein B, lipoprotein C, lipoprotein D, Lp(a) lipoprotein or arginine-rich apolipoprotein of normal human serum (for nomenclature for serum lipoprotein families and apolipoptoteins, see Alaupovic, P., Kostner, G., Lee, D. M., McConathy, W.J. and Magnani, HN. (1972) Expo. Annu. Biochem. Med. 31, 145-160 and Alaupovic, P., Lee, D.M. and McConathy, W.J., (1972) Biochim. Biophys. Acta 260, 689-707.) These membrane preparations also reacted negatively with commercially available antisera to alpha- and beta-lipoproteins. 2. The normal serum very low density, low density and high density lipoproteins formed no precipitin lines with antibodies to either intact or EDTA-extracted ghosts. 3. The serum apolipoproteins and their constitutive polypeptides (A-I, A-II, B, C-I, C-II, C-III, D and arginine-rich apolipoprotein) reacted negatively with antibodies to intact or EDTA-extracted ghosts. The EDTA and Triton X-100 extracts of erythrocyte ghosts gave no reaction with monospecific antibodies to serum apolipoproteins and their constitutive polypeptides. 4. Ghosts dissolved 2% sodium dodecyl sulfate gave positive immunoprecipitin lines with antisera to alpha- and beta-lipoproteins. However, the sodium dodecyl sulfate solution in concentrations greater than 0.1% also formed precipitin lines with antisera to the same lipoproteins. 5. These results do not support the suggestion (Langdon, R.G. (1974) Biochim. Biophys. Acta 342, 213-228) that serum apolipoptoteins are integral protein constituents of human erythrocyte ghosts. The immunoprecipitin lines observed in the latter study might have been due to the presence of trace amounts of serum lipoproteins loosely attached to the cellular surfaces or, more probably, resulted from nonspecific interactions between the proteins and the sodium dodecyl sulfate used as the

  19. Single nucleotide polymorphisms of APOA1 gene and their relationship with serum apolipoprotein A-I concentrations in the native population of Assam

    PubMed Central

    Bora, Kaustubh; Pathak, Mauchumi Saikia; Borah, Probodh; Hussain, Md. Iftikar; Das, Dulmoni

    2015-01-01

    Background There is a growing interest in the role of allelic variants of the APOA1 gene in relation to a number of disorders. We described two common polymorphisms of the APOA1 gene, G-75A and C+83T and investigated their potential influence on the serum apolipoprotein A-I (apo A-I) levels in the native population of Assam — a region that is ethnically distinct and from where no information is hitherto available. Methods Blood samples were collected from 150 healthy volunteers. Apo A-I levels were estimated by immunoturbidometry. Genotyping was done by a PCR-RFLP method that involved DNA extraction from whole blood, followed by polymerase chain reaction and digestion of the PCR product by MspI restriction enzyme, and analysis of fragment sizes in 12% polyacrylamide gel. Results The GG variant at G-75A locus and CC variant at C+83T locus were the most prevalent. GG/CC was the most common combination. Homozygous TT genotype was not detected in any of the subjects. The rare allele frequencies for the G-75A and C+83T sites were found to be 0.22 and 0.06 respectively, which significantly differed from those reported in some other populations in neighbouring regions. Serum apo A-I concentrations did not vary significantly across the detected genotypes. These findings were consistent in both sexes. Conclusion We described the distribution of the G-75A and C+83T polymorphisms of the APOA1 gene in the population of Assam for the first time. These polymorphisms were not found to directly influence apo A-I concentrations in this population either individually or synergistically. PMID:26702398

  20. E1A represses apolipoprotein AI enhancer activity in liver cells through a pRb- and CBP-independent pathway.

    PubMed Central

    Kilbourne, E J; Evans, M J; Karathanasis, S K

    1998-01-01

    The apolipoprotein AI (apoAI) promoter/enhancer contains multiple cis -acting elements on which a variety of hepatocyte-enriched and ubiquitous transcription factors function synergistically to regulate liver-specific transcription. Adenovirus E1A proteins repress tissue-specific gene expression and disrupt the differentiated state in a variety of cell types. In this study expression of E1A 12Sor 13S in hepatoblastoma HepG2 cells repressed apoAI enhancer activity 8-fold. Deletion mapping analysis showed that inhibition by E1A was mediated by the apoAI promoter site B. E1A selectively inhibited the ability of HNF3beta and HNF3alpha to transactivate reporter genes controlled by the apoAI site B and the HNF3 binding site from the transthyretin promoter. The E1A-mediated repression of HNF3 activity was not reversed by overexpression of HNF3beta nor did E1A alter nuclear HNF3beta protein levels or inhibit HNF3 binding to DNA in mobility shift assays. Overexpression of two cofactors known to interact with E1A, pRb and CBP failed to overcome inhibition of HNF3 activity. Similarly, mutations in E1A that disrupt its interaction with pRb or CBP did not compromise its ability to repress HNF3beta transcriptional activity. These data suggest that E1A inhibits HNF3 activity by inactivating a limiting cofactor(s) distinct from pRb or CBP. PMID:9512550

  1. ISOFORMS OF APOLIPOPROTEIN A-I IN THE SERUM OF BROWN BULLHEADS (AMEIURUS NEBULOSUS) WITH LIVER CANCER

    EPA Science Inventory

    1. Serum samples from 10 tumor-bearing (all fish with cholangiocellular carcinomas, some with both cholangio- and hepatocellular carcinomas) and 8 non-tumor-bearing brown bullheads were analyzed by 2D-PAGE. . Two isoforms of Apolipoproteins A-1 with a molecular weight of 28 kDA w...

  2. Antiatherogenic effects of newly developed apolipoprotein A-I mimetic peptide/phospholipid complexes against aortic plaque burden in Watanabe-heritable hyperlipidemic rabbits.

    PubMed

    Iwata, Atsushi; Miura, Shin-ichiro; Zhang, Bo; Imaizumi, Satoshi; Uehara, Yoshinari; Shiomi, Masashi; Saku, Keijiro

    2011-10-01

    This study analyzed the antiatherogenic effects of newly developed apolipoprotein A-I (ApoA-I) mimetic peptide/phospholipid complexes (ETC-642) against the aortic plaque burden in vivo. We used human macrophage cells to analyze cholesterol efflux by ETC-642. Watanabe-heritable hyperlipidemic (WHHL) rabbits were divided into 3 groups: low- (15mg/kg) and high-dose ETC-642 (50mg/kg), and placebo. The test material was injected twice/week for 12 weeks. The aortic plaque burden was assessed by intravascular ultrasound (IVUS) at 0 and 12 weeks. Plasma lipid profiles were analyzed by capillary isotachophoresis every 4 weeks. ETC-642 had an effect on cholesterol efflux comparable to that of conventional rHDL. In WHHL rabbits, high-dose ETC-642 inhibited the progression of aortic atherosclerosis compared to placebo. There was no change in the percentage of plaque volume (%PV) in the high-dose group between before (30.9%) and after infusion (28.6%), whereas there was a significant increase in the control group from 27.8% to 37.9%. ETC-642 significantly reduced charge-modified low-density lipoprotein (LDL) by converting more negative-charged modified LDL to less negative-charged LDL, and reduced small dense (sd) LDL by converting it into large, buoyant (lb) LDL. Changes in the %PV were positively correlated with changes in negative-charged modified LDL (r=0.61, p<0.01) and sdLDL (r=0.59, p<0.01), and negatively correlated with changes in less negative-charged LDL (r=-0.43, p<0.01) and lbLDL (r=-0.57, p<0.01). In conclusion, the ETC-642-induced remodeling of sdLDL to large and lbLDL and the enhancement of cholesterol efflux may prevent progression of the aortic plaque burden. HDL-based therapy may be useful for preventing the progression of plaque volume. PMID:21696737

  3. Myeloperoxidase-derived oxidants modify apolipoprotein A-I and generate dysfunctional high-density lipoproteins: comparison of hypothiocyanous acid (HOSCN) with hypochlorous acid (HOCl).

    PubMed

    Hadfield, Katrina A; Pattison, David I; Brown, Bronwyn E; Hou, Liming; Rye, Kerry-Anne; Davies, Michael J; Hawkins, Clare L

    2013-01-15

    Oxidative modification of HDLs (high-density lipoproteins) by MPO (myeloperoxidase) compromises its anti-atherogenic properties, which may contribute to the development of atherosclerosis. Although it has been established that HOCl (hypochlorous acid) produced by MPO targets apoA-I (apolipoprotein A-I), the major apolipoprotein of HDLs, the role of the other major oxidant generated by MPO, HOSCN (hypothiocyanous acid), in the generation of dysfunctional HDLs has not been examined. In the present study, we characterize the structural and functional modifications of lipid-free apoA-I and rHDL (reconstituted discoidal HDL) containing apoA-I complexed with phospholipid, induced by HOSCN and its decomposition product, OCN- (cyanate). Treatment of apoA-I with HOSCN resulted in the oxidation of tryptophan residues, whereas OCN- induced carbamylation of lysine residues to yield homocitrulline. Tryptophan residues were more readily oxidized on apoA-I contained in rHDLs. Exposure of lipid-free apoA-I to HOSCN and OCN- significantly reduced the extent of cholesterol efflux from cholesterol-loaded macrophages when compared with unmodified apoA-I. In contrast, HOSCN did not affect the anti-inflammatory properties of rHDL. The ability of HOSCN to impair apoA-I-mediated cholesterol efflux may contribute to the development of atherosclerosis, particularly in smokers who have high plasma levels of SCN- (thiocyanate). PMID:23088652

  4. Human crypt intestinal epithelial cells are capable of lipid production, apolipoprotein synthesis, and lipoprotein assembly.

    PubMed

    Levy, E; Beaulieu, J F; Delvin, E; Seidman, E; Yotov, W; Basque, J R; Ménard, D

    2000-01-01

    The recent availability of spontaneously proliferating, non-transformed human crypt intestinal epithelial cells (HIEC) affords an opportunity to investigate lipid metabolism in undifferentiated enterocytes. The major purpose of this study was to explore the capability of undifferentiated crypt cells to synthesize, assemble, and secrete lipids and apolipoproteins. HIEC were cultured in medium with 5% fetal bovine serum for 5 to 21 d. The cells were clearly able to incorporate [(14)C]oleic acid (dpm/mg protein) into triglycerides (128,279 +/- 16,988), phospholipids (30, 278 +/- 2,107), and cholesteryl esters (2,180 +/- 207). Although improvement in lipid secretion was noted with prolongation of cell culture periods, low efficiency of lipid export (10.3 +/- 2.2% of intracellular content) characterized the HIEC. All phospholipid classes were elaborated, with phosphatidylcholine accounting for 79. 3 +/- 1.3% of cellular phospholipids. Chylomicrons were the dominant (46.4%) lipoproteins secreted, followed by high, low, and very low density lipoproteins (HDL, LDL, and VLDL) comprising 22.5, 20.2, and 10.8% of the total, respectively. HIEC elaborated most of the major apolipoprotein (apo) classes (A-I, A-IV, B-100, C, and E), but were less efficient in producing apoB-48. In contrast to the production of apoA-I and C as early as 5 days after confluence, apoA-I and A-IV were maximally expressed at 11 d. Culture media accumulated much more apoB-100 than apoB-48 (B-48/B-100 ratio 0.21 +/- 0.03), reflecting limited apoB mRNA editing. HIEC demonstrated both endogenous cholesterol synthesis and LDL receptor expression. Cholesterol synthesis was sensitive to 25-hydroxycholesterol and mevinolin, but unresponsive to LDL treatment, suggesting independent regulation pathways. In contrast, LDL inhibited receptor activity. The present findings provide the first solid evidence that immature HIEC are capable of key fat absorptive functions of well-differentiated enterocytes. The

  5. Comparison of High-Density Lipoprotein Cholesterol to Apolipoprotein A-I and A-II to Predict Coronary Calcium and the Effect of Insulin Resistance

    PubMed Central

    Martin, Seth S.; Qasim, Atif N.; Wolfe, Megan; Clair, Caitlin; Schwartz, Stanley; Iqbal, Nayyar; Schutta, Mark; Bagheri, Roshanak; Mehta, Nehal N.; Rader, Daniel J.; Reilly, Muredach P.

    2011-01-01

    High-density lipoprotein (HDL) cholesterol and its apolipoproteins each capture unique lipid and cardiometabolic information important to risk quantification. It was hypothesized that metabolic factors, including insulin resistance and type 2 diabetes, would confound the association of HDL cholesterol with coronary artery calcification (CAC) and that apolipoprotein A-I (apoA-I) and/or apolipoprotein A-II (apoA-II) would add to HDL cholesterol in predicting CAC. Two community-based cross-sectional studies of white subjects were analyzed: the Penn Diabetes Heart Study (PDHS; n = 611 subjects with type 2 diabetes, 71.4% men) and the Study of Inherited Risk of Coronary Atherosclerosis (SIRCA; n = 803 subjects without diabetes, 52.8% men) using multivariable analysis of apoA-I, apoA-II, and HDL cholesterol stratified by diabetes status. HDL cholesterol was inversely associated with CAC after adjusting for age and gender in whites with type 2 diabetes (tobit ratio for a 1-SD increase in HDL cholesterol 0.58, 95% confidence interval [CI] 0.44 to 0.77, p <0.001) as well as those without diabetes (tobit ratio 0.72, 95% CI 0.59 to 0.88, p = 0.001). In contrast, apoA-I was a weaker predictor in subjects with (tobit ratio 0.64, 95% CI 0.45 to 0.90, p = 0.010) and without (tobit ratio 0.79, 95% CI 0.66 to 0.94, p = 0.010) diabetes, while apoA-II had no association with CAC. Control for metabolic variables, including triglycerides, waist circumference, and homeostasis model assessment of insulin resistance, attenuated these relations, particularly in subjects without diabetes. In likelihood ratio test analyses, HDL cholesterol added to apoA-I, apoA-II, and atherogenic apolipoprotein B lipoproteins but improved CAC prediction over metabolic factors only in subjects with diabetes. In conclusion, HDL cholesterol outperformed apoA-I and apoA-II in CAC prediction, but its association with CAC was attenuated by measures of insulin resistance. PMID:21257004

  6. Comparison of high-density lipoprotein cholesterol to apolipoprotein A-I and A-II to predict coronary calcium and the effect of insulin resistance.

    PubMed

    Martin, Seth S; Qasim, Atif N; Wolfe, Megan; St Clair, Caitlin; Schwartz, Stanley; Iqbal, Nayyar; Schutta, Mark; Bagheri, Roshanak; Mehta, Nehal N; Rader, Daniel J; Reilly, Muredach P

    2011-02-01

    High-density lipoprotein (HDL) cholesterol and its apolipoproteins each capture unique lipid and cardiometabolic information important to risk quantification. It was hypothesized that metabolic factors, including insulin resistance and type 2 diabetes, would confound the association of HDL cholesterol with coronary artery calcification (CAC) and that apolipoprotein A-I (apoA-I) and/or apolipoprotein A-II (apoA-II) would add to HDL cholesterol in predicting CAC. Two community-based cross-sectional studies of white subjects were analyzed: the Penn Diabetes Heart Study (PDHS; n = 611 subjects with type 2 diabetes, 71.4% men) and the Study of Inherited Risk of Coronary Atherosclerosis (SIRCA; n = 803 subjects without diabetes, 52.8% men) using multivariable analysis of apoA-I, apoA-II, and HDL cholesterol stratified by diabetes status. HDL cholesterol was inversely associated with CAC after adjusting for age and gender in whites with type 2 diabetes (tobit ratio for a 1-SD increase in HDL cholesterol 0.58, 95% confidence interval [CI] 0.44 to 0.77, p <0.001) as well as those without diabetes (tobit ratio 0.72, 95% CI 0.59 to 0.88, p = 0.001). In contrast, apoA-I was a weaker predictor in subjects with (tobit ratio 0.64, 95% CI 0.45 to 0.90, p = 0.010) and without (tobit ratio 0.79, 95% CI 0.66 to 0.94, p = 0.010) diabetes, while apoA-II had no association with CAC. Control for metabolic variables, including triglycerides, waist circumference, and homeostasis model assessment of insulin resistance, attenuated these relations, particularly in subjects without diabetes. In likelihood ratio test analyses, HDL cholesterol added to apoA-I, apoA-II, and atherogenic apolipoprotein B lipoproteins but improved CAC prediction over metabolic factors only in subjects with diabetes. In conclusion, HDL cholesterol outperformed apoA-I and apoA-II in CAC prediction, but its association with CAC was attenuated by measures of insulin resistance. PMID:21257004

  7. Apolipoprotein E promotes lipid accumulation and differentiation in human adipocytes

    SciTech Connect

    Lasrich, Dorothee; Bartelt, Alexander; Grewal, Thomas; Heeren, Joerg

    2015-09-10

    Several studies in mice indicate a role for apolipoprotein E (APOE) in lipid accumulation and adipogenic differentiation in adipose tissue. However, little is yet known if APOE functions in a similar manner in human adipocytes. This prompted us to compare lipid loading and expression of adipocyte differentiation markers in APOE-deficient and control adipocytes using the differentiated human mesenchymal stem cell line hMSC-Tert as well as primary human and mouse adipocytes as model systems. Differentiated hMSC-Tert were stably transduced with or without siRNA targeting APOE while murine adipocytes were isolated from wild type and Apoe knockout mice. Human APOE knockdown hMSC-Tert adipocytes accumulated markedly less triglycerides compared to control cells. This correlated with strongly decreased gene expression levels of adipocyte markers such as adiponectin (ADIPOQ) and fatty acid binding protein 4 (FABP4) as well as the key transcription factor driving adipocyte differentiation, peroxisome proliferator activator receptor gamma (PPARG), in particular the PPARG2 isoform. Similarly, differentiation of murine Apoe-deficient adipocytes was characterized by reduced gene expression of Adipoq, Fabp4 and Pparg. Interestingly, incubation of APOE-deficient hMSC-Tert adipocytes with conditioned media from APOE3-overexpressing adipocytes or APOE-containing Very Low Density Lipoprotein (VLDL) partially restored triglyceride accumulation, but were unable to induce adipocyte differentiation, as judged by expression of adipocyte markers. Taken together, depletion of endogenous APOE in human adipocytes severely impairs lipid accumulation, which is associated with an inability to initiate differentiation. - Highlights: • Immortalized human mesenchymal stem cells were used to study adipocyte development. • Knockdown of endogenous APOE lead to impaired lipid accumulation and adipogenesis. • APOE supplementation partially restored lipid accumulation but not differentiation.

  8. Förster resonance energy transfer measurements are consistent with a helical bundle model for lipid-free apolipoprotein A-I.

    PubMed

    Brouillette, Christie G; Dong, Wen-Ji; Yang, Zhengrong W; Ray, Marjorie J; Protasevich, Irina I; Cheung, Herbert C; Engler, Jeffrey A

    2005-12-20

    Apolipoprotein (apo) A-I mutants were constructed for FRET studies to distinguish between two possible lipid-free conformers, a globular helix bundle and an elongated helical hairpin. Mutants containing a single Trp at position 50 were prepared by replacing Trps at positions 8, 72, and 108 with Phe (W@50). Two mutants were constructed from W@50 by incorporating Cys at Arg83 (W@50R83C) or Arg173 (W@50R173C) for attachment of the fluorescent probe AEDANS. Secondary structure of the mutants is very similar to wild type (wt) apo A-I, and fluorescence emission indicates that W50 is protected from solvent. Thermal stabilities of the AEDANS-labeled mutants are also similar to wt. These results indicate that no discernible changes occur in structure or stability as a result of mutations or labeling. The FRET data from W@50 to AEDANS are well-represented by a single distance distribution function with a distance of approximately 22 A for W@50R83C and approximately 19 A for W@50R173C. These distances are consistent with theoretical values calculated from a helical bundle model but not from a helical hairpin. A probability distance distribution function yields significantly small half-width values of 5.6 and 3.7 A, respectively, suggesting low conformational dynamics in both mutants. Differential scanning calorimetry (DSC) was performed on wt and a C-terminal deletion mutant, Delta(187-243), to obtain information on domain architecture. Contrary to expectations, both proteins unfold cooperatively. The results are consistent with the presence of a single folded domain within residues 1-186. These results support the presence of a discrete globular bundle conformation for lipid-free apo A-I. PMID:16342934

  9. Cholesterol efflux to high-density lipoproteins and apolipoprotein A-I phosphatidylcholine complexes is inhibited by ethanol: role of apolipoprotein structure and cooperative interaction of phosphatidylcholine and cholesterol.

    PubMed

    Avdulov, N A; Chochina, S V; Igbavboa, U; Wood, W G

    2000-08-29

    There is a substantial body of evidence showing that moderate alcohol consumption is associated with a reduced risk of cardiovascular morbidity and mortality. One of the factors thought to contribute to this reduction in risk is an increase in the level of high-density lipoproteins (HDL) correlated with alcohol consumption. However, HDL levels are elevated in heavy drinkers, but their risk of vascular disease is greater compared with that of moderate drinkers. Ethanol at concentrations observed in heavy drinkers and alcoholics may directly act on HDL and apolipoproteins and in turn modify cholesterol efflux. In this paper, we show that ethanol significantly inhibited cholesterol efflux from fibroblasts to HDL and to apolipoprotein A-I (apoA-I) complexed with phosphatidylcholine (PC). Ethanol significantly inhibited binding of PC to apoA-I, inhibited incorporation of cholesterol only when apoA-I contained PC, and did not alter incorporation of cholesterol into HDL. ApoA-I structure was altered by ethanol as monitored by steady-state fluorescence polarization of tryptophan residues. The absence of ethanol effects on incorporation of cholesterol into HDL versus inhibition of cholesterol incorporation into the apoA-I-PC complex suggests that the effects of ethanol on cholesterol efflux mediated by HDL involve interaction with the cell surface and that efflux mediated by the apoA-I-PC complex is a combination of aqueous diffusion and contact with the cell surface. In addition, effects of ethanol on apoA-I suggest that pre-beta-HDL or lipid-free apoA-I may be more perturbed by ethanol than mature HDL, and such effects may be pathophysiological with respect to the process of reverse cholesterol transport in heavy drinkers and alcoholics. PMID:10956052

  10. Structure of human apolipoprotein A-IV: a distinct domain architecture among exchangeable apolipoproteins with potential functional implications.

    PubMed

    Pearson, Kevin; Saito, Hiroyuki; Woods, Stephen C; Lund-Katz, Sissel; Tso, Patrick; Phillips, Michael C; Davidson, W Sean

    2004-08-24

    Apolipoprotein A-IV (apoA-IV) is an exchangeable apolipoprotein that shares many functional similarities with related apolipoproteins such as apoE and apoA-I but has also been implicated as a circulating satiety factor. However, despite the fact that it contains many predicted amphipathic alpha-helical domains, relatively little is known about its tertiary structure. We hypothesized that apoA-IV exhibits a characteristic functional domain organization that has been proposed to define apoE and apoA-I. To test this, we created truncation mutants in a bacterial system that deleted amino acids from either the N- or C-terminal ends of human apoA-IV. We found that apoA-IV was less stable than apoA-I but was more highly organized in terms of its cooperativity of unfolding. Deletion of the extreme N and C termini of apoA-IV did not significantly affect the cooperativity of unfolding, but deletions past amino acid 333 on the C terminus or amino acid 61 on the N terminus had major destabilizing effects. Functionally, apoA-IV was less efficient than apoA-I at clearing multilamellar phospholipid liposomes and promoting ATP-binding cassette transporter A1-mediated cholesterol efflux. However, deletion of a C-terminal region of apoA-IV, which is devoid of predicted amphipathic alpha helices (amino acids 333-376) stimulated both of these activities dramatically. We conclude that the amphipathic alpha helices in apoA-IV form a single, large domain that may be similar to the N-terminal helical bundle domains of apoA-I and apoE but that apoA-IV lacks the C-terminal lipid-binding and cholesterol efflux-promoting domain present in these apolipoproteins. In fact, the C terminus of apoA-IV appears to reduce the ability of apoA-IV to interact with lipids and promote cholesterol efflux. This indicates that, although apoA-IV may have evolved from gene duplication events of ancestral apolipoproteins and shares the basic amphipathic helical building blocks, the overall localization of

  11. Apolipoprotein E promotes lipid accumulation and differentiation in human adipocytes.

    PubMed

    Lasrich, Dorothee; Bartelt, Alexander; Grewal, Thomas; Heeren, Joerg

    2015-09-10

    Several studies in mice indicate a role for apolipoprotein E (APOE) in lipid accumulation and adipogenic differentiation in adipose tissue. However, little is yet known if APOE functions in a similar manner in human adipocytes. This prompted us to compare lipid loading and expression of adipocyte differentiation markers in APOE-deficient and control adipocytes using the differentiated human mesenchymal stem cell line hMSC-Tert as well as primary human and mouse adipocytes as model systems. Differentiated hMSC-Tert were stably transduced with or without siRNA targeting APOE while murine adipocytes were isolated from wild type and Apoe knockout mice. Human APOE knockdown hMSC-Tert adipocytes accumulated markedly less triglycerides compared to control cells. This correlated with strongly decreased gene expression levels of adipocyte markers such as adiponectin (ADIPOQ) and fatty acid binding protein 4 (FABP4) as well as the key transcription factor driving adipocyte differentiation, peroxisome proliferator activator receptor gamma (PPARG), in particular the PPARG2 isoform. Similarly, differentiation of murine Apoe-deficient adipocytes was characterized by reduced gene expression of Adipoq, Fabp4 and Pparg. Interestingly, incubation of APOE-deficient hMSC-Tert adipocytes with conditioned media from APOE3-overexpressing adipocytes or APOE-containing Very Low Density Lipoprotein (VLDL) partially restored triglyceride accumulation, but were unable to induce adipocyte differentiation, as judged by expression of adipocyte markers. Taken together, depletion of endogenous APOE in human adipocytes severely impairs lipid accumulation, which is associated with an inability to initiate differentiation. PMID:26201081

  12. Distinct Hepatic Receptors for Low Density Lipoprotein and Apolipoprotein E in Humans

    NASA Astrophysics Data System (ADS)

    Hoeg, Jeffrey M.; Demosky, Stephen J.; Gregg, Richard E.; Schaefer, Ernst J.; Brewer, H. Bryan

    1985-02-01

    Since the liver is a central organ for lipid and lipoprotein synthesis and catabolism, hepatic receptors for specific apolipoproteins on plasma lipoproteins would be expected to modulate lipid and lipoprotein metabolism. The role of hepatic receptors for low density lipoproteins and apolipoprotein E-containing lipoproteins was evaluated in patients with complementary disorders in lipoprotein metabolism: abetalipoproteinemia and homozygous familial hypercholesterolemia. In addition, hepatic membranes from a patient with familial hypercholesterolemia were studied and compared before and after portacaval shunt surgery. The results establish that the human liver has receptors for apolipoproteins B and E. Furthermore, in the human, hepatic receptors for low density lipoproteins and apolipoprotein E are genetically distinct and can undergo independent control.

  13. Decreases in serum apolipoprotein B-100 and A-I concentrations in cows with milk fever and downer cows

    PubMed Central

    Oikawa, Shin; Katoh, Norio

    2002-01-01

    Milk fever occurring during the peripartum period has been suggested to be caused by fatty liver developed during the nonlactating stage because diseased cows have increased serum concentrations of non-esterified fatty acids (NEFA) and show hepatic lipidosis. In cows with fatty liver and related diseases such as ketosis, serum concentrations of apolipoprotein (apo) B-100 and apoA-I are decreased. The purpose of the present study was to examine whether apoB-100 and apoA-I concentrations are similarly decreased in cows with milk fever. Apolipoprotein concentrations were also measured in cows with downer syndrome, which has been suggested to be related, at least in part, to milk fever. Compared with healthy cows during early lactation, apoB-100 and apoA-I concentrations were decreased in cows with milk fever and also in downer cows. In cows with milk fever, the decreases in apoB-100 and apoA-I concentrations were associated with increased NEFA and decreased cholesterol and phospholipid concentrations. However, in downer cows, serum lipid concentration changes were not as distinct as in cows with milk fever. These results, coupled with previous findings on the decreases in apoB-100 and apoA-I concentrations of cows with fatty liver-related diseases, suggest that fatty liver is involved in the development of milk fever and partly in that of downer cow syndrome. PMID:11858646

  14. Solubility engineering and crystallization of human apolipoprotein D

    PubMed Central

    Nasreen, Amber; Vogt, Martin; Kim, Hyun Jin; Eichinger, Andreas; Skerra, Arne

    2006-01-01

    Human apolipoprotein D (ApoD) is a physiologically important member of the lipocalin protein family that was discovered as a peripheral subunit of the high-density lipoprotein (HDL) but is also abundant in other body fluids and organs, including neuronal tissue. Although it has been possible to produce functional ApoD in the periplasm of Escherichia coli and to demonstrate its ligand-binding activity for progesterone and arachidonic acid, the recombinant protein suffers from a pronounced tendency to aggregate and to adsorb to vessel surfaces as well as chromatography matrices, thus hampering further structural investigation. Here, we describe a systematic mutagenesis study directed at presumably exposed hydrophobic side chains of the unglycosylated recombinant protein. As a result, one ApoD mutant with just three new amino acid substitutions—W99H, I118S, and L120S—was identified, which exhibits the following features: (1) improved yield upon periplasmic biosynthesis in E. coli, (2) elution as a monomeric protein from a gel permeation chromatography column, and (3) unchanged binding activity for its physiological ligands. In addition, the engineered ApoD was successfully crystallized (space group I4 with unit cell parameters a = 75.1 Å, b = 75.1 Å, c = 166.0 Å, α = β = γ = 90°), thus demonstrating its conformationally homogeneous behavior and providing a basis for the future X-ray structural analysis of this functionally still puzzling protein. PMID:16322568

  15. High density lipoprotein deficiency with xanthomas. A defect in reverse cholesterol transport caused by a point mutation in the apolipoprotein A-I gene.

    PubMed Central

    Lackner, K J; Dieplinger, H; Nowicka, G; Schmitz, G

    1993-01-01

    A 7-yr-old girl with high density lipoprotein (HDL) deficiency and xanthomas has been identified in a Turkish kindred with repetitive consanguinity. She has severely reduced HDL-cholesterol and no apolipoprotein (apo) A-I. ApoA-II is reduced, whereas apoA-IV and apoC-III are normal. ApoB and low density lipoprotein (LDL)-cholesterol are increased. This is reflected in hypercholesterolemia. VLDL and IDL particles are low, and serum triglycerides are normal. The genetic defect could be identified as a base insertion into the third exon of the apoA-I gene. This leads to a nonsense peptide sequence beginning at amino acid 5 of the mature plasma protein and early termination of translation. The patient is homozygous for this mutation. Pedigree analysis indicated an autosomal dominant inheritance with no evidence of another genetic defect of lipoprotein metabolism in the kindred. In HDL deficiency, HDL binding to leukocytes was increased compared to normal. In the postprandial state, binding of labeled HDL3 to leukocytes is unchanged. This is in contrast to results with postprandially isolated leukocytes from controls or Tangier patients, which have a reduced binding capacity for HDL3. These results indicate that postprandial HDL precursors may compete the binding of labeled HDL3. The metabolic consequences of HDL deficiency were analyzed. There is only a small number of HDL-like particles containing apoA-II, apoA-IV, apoE, and lecithin/cholesteryl acyl transferase. The C-apolipoproteins were normal in the proband. Due to the lack of HDL they can only associate with apoB-containing particles, where they may interfere with cellular uptake. Thus, pure apoA-I deficiency leads to a complex metabolic derangement. Images PMID:7693760

  16. An abundant dysfunctional apolipoprotein A1 in human atheroma

    PubMed Central

    Huang, Ying; DiDonato, Joseph A.; Levison, Bruce S.; Schmitt, Dave; Li, Lin; Wu, Yuping; Buffa, Jennifer; Kim, Timothy; Gerstenecker, Gary; Gu, Xiaodong; Kadiyala, Chandra; Wang, Zeneng; Culley, Miranda K.; Hazen, Jennie E.; DiDonato, Anthony J.; Fu, Xiaoming; Berisha, Stela; Peng, Daoquan; Nguyen, Truc; Liang, Shaohong; Chuang, Chia-Chi; Cho, Leslie; Plow, Edward F.; Fox, Paul L.; Gogonea, Valentin; Tang, W.H. Wilson; Parks, John S.; Fisher, Edward A.; Smith, Jonathan D.; Hazen, Stanley L.

    2014-01-01

    Recent studies indicate high density lipoproteins (HDL) and their major structural protein, apolipoprotein A1 (apoA1), recovered from human atheroma, are dysfunctional and extensively oxidized by myeloperoxidase (MPO), while in vitro oxidation of apoA1/HDL by MPO impairs its cholesterol acceptor function. We developed a high affinity monoclonal antibody (mAb) that specifically recognizes apoA1/HDL modified by the MPO/H2O2/Cl-system using phage display affinity maturation. An oxindolyl alanine (2-OH-Trp) moiety at tryptophan 72 of apoA1 is the immunogenic epitope. Mutagenesis studies confirm a critical role for apoA1 Trp72 in MPO-mediated inhibition of ABCA1-dependent cholesterol acceptor activity of apoA1 in vitro and in vivo. ApoA1 containing a 2-OH-Trp72 group (oxTrp72-apoA1) is in low abundance within the circulation, but accounts for 20% of the apoA1 in atherosclerotic plaque. OxTrp72-apoA1 recovered from human atheroma or plasma was lipid-poor, virtually devoid of cholesterol acceptor activity, and demonstrated both potent pro-inflammatory activities on endothelial cells and impaired HDL biogenesis activity in vivo. Elevated oxTrp72-apoA1 levels in subjects presenting to a cardiology clinic (n=627) were associated with increased cardiovascular disease risk. Circulating oxTrp72-apoA1 levels may serve as a way to monitor a pro-atherogenic process in the artery wall. PMID:24464187

  17. An abundant dysfunctional apolipoprotein A1 in human atheroma.

    PubMed

    Huang, Ying; DiDonato, Joseph A; Levison, Bruce S; Schmitt, Dave; Li, Lin; Wu, Yuping; Buffa, Jennifer; Kim, Timothy; Gerstenecker, Gary S; Gu, Xiaodong; Kadiyala, Chandra S; Wang, Zeneng; Culley, Miranda K; Hazen, Jennie E; Didonato, Anthony J; Fu, Xiaoming; Berisha, Stela Z; Peng, Daoquan; Nguyen, Truc T; Liang, Shaohong; Chuang, Chia-Chi; Cho, Leslie; Plow, Edward F; Fox, Paul L; Gogonea, Valentin; Tang, W H Wilson; Parks, John S; Fisher, Edward A; Smith, Jonathan D; Hazen, Stanley L

    2014-02-01

    Recent studies have indicated that high-density lipoproteins (HDLs) and their major structural protein, apolipoprotein A1 (apoA1), recovered from human atheroma are dysfunctional and are extensively oxidized by myeloperoxidase (MPO). In vitro oxidation of either apoA1 or HDL particles by MPO impairs their cholesterol acceptor function. Here, using phage display affinity maturation, we developed a high-affinity monoclonal antibody that specifically recognizes both apoA1 and HDL that have been modified by the MPO-H2O2-Cl(-) system. An oxindolyl alanine (2-OH-Trp) moiety at Trp72 of apoA1 is the immunogenic epitope. Mutagenesis studies confirmed a critical role for apoA1 Trp72 in MPO-mediated inhibition of the ATP-binding cassette transporter A1 (ABCA1)-dependent cholesterol acceptor activity of apoA1 in vitro and in vivo. ApoA1 containing a 2-OH-Trp72 group (oxTrp72-apoA1) is in low abundance within the circulation but accounts for 20% of the apoA1 in atherosclerosis-laden arteries. OxTrp72-apoA1 recovered from human atheroma or plasma is lipid poor, virtually devoid of cholesterol acceptor activity and demonstrated both a potent proinflammatory activity on endothelial cells and an impaired HDL biogenesis activity in vivo. Elevated oxTrp72-apoA1 levels in subjects presenting to a cardiology clinic (n = 627) were associated with increased cardiovascular disease risk. Circulating oxTrp72-apoA1 levels may serve as a way to monitor a proatherogenic process in the artery wall. PMID:24464187

  18. Fibrinogen Alpha Chain Precursor and Apolipoprotein A-I in Urine as Biomarkers for Noninvasive Diagnosis of Calcium Oxalate Nephrolithiasis: A Proteomics Study

    PubMed Central

    Zhu, Wei; Liu, Min; Wang, Guang-Chun; Peng, Bo; Yan, Yang; Che, Jian-Ping; Ma, Qing-Wei; Yao, Xu-Dong; Zheng, Jun-Hua

    2014-01-01

    Calcium oxalate nephrolithiasis is the most common urological disease, but noninvasive and convenient methods of diagnosis are rarely available. Objective. The present study aimed to identify potential urine biomarkers for noninvasive diagnosis of CaOx nephrolithiasis. Methodology. Urine samples from 72 patients with CaOx nephrolithiasis and 30 healthy controls were collected and proteomics analysis was performed using matrix-assisted laser desorption/ionization-time of flight-mass spectrometer (MALDI-TOF-MS). Results. Thirteen proteins/peptides displayed statistically significant differences. The peptides of m/z 1207.23 and 2773.86 were selected by the genetic algorithm (GA) to build a possible diagnostic model. The area under the curve of m/z 1207.23 and 2773.86 was 0.936 and 0.987, respectively. The diagnostic model in distinguishing patients and healthy subjects showed 100% sensitivity and specificity. The peak at m/z 2773.86 was identified as fibrinogen alpha chain (FGA) with the sequence G.EGDFLAEGGGVR.G, and the peak at m/z 2773.86 was identified as apolipoprotein A-I (apoA-I) with the sequence L.PVLESFKVSFLSALEEYTKKLNTQ. Conclusion. The study results strongly suggested that urinary FGA and apoA-I are highly sensitive and specific biomarkers for noninvasive diagnosis of CaOx nephrolithiasis. PMID:25147800

  19. Overexpression of apolipoprotein A-I fused to an anti-transforming growth factor beta peptide modulates the tumorigenicity and immunogenicity of mouse colon cancer cells.

    PubMed

    Medina-Echeverz, José; Vasquez, Marcos; Gomar, Celia; Ardaiz, Nuria; Berraondo, Pedro

    2015-06-01

    Transforming growth factor beta (TGF-β) promotes tumor growth, invasion and metastasis in established tumors. In this study, we analyzed the effect of overexpressing an anti-TGF-β peptide fused to apolipoprotein A-I (ApoA-I) as a scaffold molecule. We generated and characterized stable MC38 colon carcinoma clones expressing ApoA-I fused to the anti-TGF-β peptide P144 and ApoA-I as control cells. We evaluated in vitro the gene expression profile, cell cycle and anchorage-independent growth. The in vivo tumorigenic potential and immunogenicity were analyzed inoculating the MC38 clones into C57BL/6 mice, recombination-activating gene 1 knockout mice or mice deficient in NK cells either subcutaneously or intrasplenically to generate hepatic metastases. While overexpression of ApoA-I had no effect on the parameters analyzed, ApoA-I fused to P144 markedly diminished the tumorigenic capacity and metastatic potential of MC38 in vitro and in vivo, thus generating a highly immunogenic cell line. MC38 cells transfected with ApoA-I fused to P144 triggered memory T cell responses able to eliminate the parental cell line upon re-challenge. In summary, expression of ApoA-I fused to P144 is a novel strategy to modulate TGF-β in tumor cells. These results highlight the potential of TGF-β as a target in the development of new antitumor treatments. PMID:25795134

  20. The “Beta-Clasp” model of apolipoprotein A-I - a lipid-free solution structure determined by electron paramagnetic resonance spectroscopy

    PubMed Central

    Lagerstedt, Jens O.; Budamagunta, Madhu S.; Liu, Grace S.; DeValle, Nicole C.; Voss, John C.; Oda, Michael N.

    2012-01-01

    Apolipoprotein A-I (apoA-I) is the major protein component of high density lipoproteins (HDL) and plays a central role in cholesterol metabolism. The lipid-free / lipid-poor form of apoA-I is the preferred substrate for the ATP-binding cassette transporter A1 (ABCA1). The interaction of apoA-I with ABCA1 leads to the formation of cholesterol laden high density lipoprotein (HDL) particles, a key step in reverse cholesterol transport and the maintenance of cholesterol homeostasis. Knowledge of the structure of lipid-free apoA-I is essential to understanding its critical interaction with ABCA1 and the molecular mechanisms underlying HDL biogenesis. We therefore examined the structure of lipid-free apoA-I by electron paramagnetic resonance spectroscopy (EPR). Through site directed spin label EPR, we mapped the secondary structure of apoA-I and identified sites of spin coupling as residues 26, 44, 64, 167, 217 and 226. We capitalize on the fact that lipid-free apoA-I self-associates in an anti-parallel manner in solution. We employed these sites of spin coupling to define the central plane in the dimeric apoA-I complex. Applying both the constraints of dipolar coupling with the EPR-derived pattern of solvent accessibility, we assembled the secondary structure into a tertiary context, providing a solution structure for lipid-free apoA-I. PMID:22245143

  1. An Evaluation of the Crystal Structure of C-terminal Truncated Apolipoprotein A-I in Solution Reveals Structural Dynamics Related to Lipid Binding.

    PubMed

    Melchior, John T; Walker, Ryan G; Morris, Jamie; Jones, Martin K; Segrest, Jere P; Lima, Diogo B; Carvalho, Paulo C; Gozzo, Fábio C; Castleberry, Mark; Thompson, Thomas B; Davidson, W Sean

    2016-03-01

    Apolipoprotein (apo) A-I mediates many of the anti-atherogenic functions attributed to high density lipoprotein. Unfortunately, efforts toward a high resolution structure of full-length apoA-I have not been fruitful, although there have been successes with deletion mutants. Recently, a C-terminal truncation (apoA-I(Δ185-243)) was crystallized as a dimer. The structure showed two helical bundles connected by a long, curved pair of swapped helical domains. To compare this structure to that existing under solution conditions, we applied small angle x-ray scattering and isotope-assisted chemical cross-linking to apoA-I(Δ185-243) in its dimeric and monomeric forms. For the dimer, we found evidence for the shared domains and aspects of the N-terminal bundles, but not the molecular curvature seen in the crystal. We also found that the N-terminal bundles equilibrate between open and closed states. Interestingly, this movement is one of the transitions proposed during lipid binding. The monomer was consistent with a model in which the long shared helix doubles back onto the helical bundle. Combined with the crystal structure, these data offer an important starting point to understand the molecular details of high density lipoprotein biogenesis. PMID:26755744

  2. Crystal Structure of C-terminal Truncated Apolipoprotein A-I Reveals the Assembly of High Density Lipoprotein (HDL) by Dimerization*

    PubMed Central

    Mei, Xiaohu; Atkinson, David

    2011-01-01

    Apolipoprotein A-I (apoA-I) plays important structural and functional roles in plasma high density lipoprotein (HDL) that is responsible for reverse cholesterol transport. However, a molecular understanding of HDL assembly and function remains enigmatic. The 2.2-Å crystal structure of Δ(185–243)apoA-I reported here shows that it forms a half-circle dimer. The backbone of the dimer consists of two elongated antiparallel proline-kinked helices (five AB tandem repeats). The N-terminal domain of each molecule forms a four-helix bundle with the helical C-terminal region of the symmetry-related partner. The central region forms a flexible domain with two antiparallel helices connecting the bundles at each end. The two-domain dimer structure based on helical repeats suggests the role of apoA-I in the formation of discoidal HDL particles. Furthermore, the structure suggests the possible interaction with lecithin-cholesterol acyltransferase and may shed light on the molecular details of the effect of the Milano, Paris, and Fin mutations. PMID:21914797

  3. Radioimmunoassay of human apolipoprotein CII. A study in normal and hypertriglyceridemic subjects.

    PubMed

    Kashyap, M L; Srivastava, L S; Chen, C Y; Perisutti, C G; Campbell, M; Lutmer, R F; Glueck, C J

    1977-07-01

    A specific, precise, and sensitive double-antibody radioimmunoassay for the measurement of human apolipoprotein CII (apoCII) was developed. ApoCII was labeled with (125)I (chloramine-T) and monospecific antibody was raised in rabbits. No appreciable cross-reactivity with apolipoproteins CI, CIII, AI, AII, low density lipoproteins, and lipoprotein-free plasma was observed. Lipoproteins containing apoCII displaced the standard curve in parallel. ApoCII measurement was not affected by pretreatment of plasma with tetramethylurea, ethanol-diethyl ether, or heating. Mean (+/-SE) plasma-immunoreactive apoCII in 47 normotriglyceridemic subjects was 51.8+/-3.2 mug/ml, generally comparable with previous estimates of its concentration by other methods. ApoCII levels in 9 subjects with type IIB lipoprotein pattern, 14 with the type IV lipoprotein pattern, and 5 with type V lipoprotein pattern were respectively, 89.9+/-4.6, 85.4+/-6.9, 132.8+/-21.0 mug/ml, all higher than normals (P < 0.001). Plasma apoCII and triglyceride concentrations correlated in normo- and hypertriglyceridemics (r = 0.36 and 0.58, P < 0.05). Plasma triglycerides correlated inversely with the fraction of total apoCII in very low density lipoprotein (VLDL)-free plasma (r = -0.75, P < 0.01). There was no correlation between plasma apoCII and high density lipoprotein cholesterol. In normotriglyceridemics, VLDL apoCII levels correlated with in vitro lipoprotein lipase (LPL) activator activities (r = 0.89, P < 0.01). In hypertriglyceridemic subjects the mean concentrations of apoCII per milligrams VLDL protein, LPL activator activity per milligrams VLDL protein, and LPL activator activity per micrograms VLDL apoCII were all lower than in normotriglyceridemics, P < 0.05. As plasma triglycerides and apoCII increase, apoCII is redistributed from high density lipoprotein to VLDL. However, the amount of apoCII per milligram VLDL protein and its LPL activator potency per milligram VLDL protein are reduced. These

  4. Protein Kinase C Controls Vesicular Transport and Secretion of Apolipoprotein E from Primary Human Macrophages*

    PubMed Central

    Karunakaran, Denuja; Kockx, Maaike; Owen, Dylan M.; Burnett, John R.; Jessup, Wendy; Kritharides, Leonard

    2013-01-01

    Macrophage-specific apolipoprotein E (apoE) secretion plays an important protective role in atherosclerosis. However, the precise signaling mechanisms regulating apoE secretion from primary human monocyte-derived macrophages (HMDMs) remain unclear. Here we investigate the role of protein kinase C (PKC) in regulating basal and stimulated apoE secretion from HMDMs. Treatment of HMDMs with structurally distinct pan-PKC inhibitors (calphostin C, Ro-31-8220, Go6976) and a PKC inhibitory peptide all significantly decreased apoE secretion without significantly affecting apoE mRNA or apoE protein levels. The PKC activator phorbol 12-myristate 13-acetate (PMA) stimulated apoE secretion, and both PMA-induced and apoAI-induced apoE secretion were inhibited by PKC inhibitors. PKC regulation of apoE secretion was found to be independent of the ATP binding cassette transporter ABCA1. Live cell imaging demonstrated that PKC inhibitors inhibited vesicular transport of apoE to the plasma membrane. Pharmacological or peptide inhibitor and knockdown studies indicate that classical isoforms PKCα/β and not PKCδ, -ϵ, -θ, or -ι/ζ isoforms regulate apoE secretion from HMDMs. The activity of myristoylated alanine-rich protein kinase C substrate (MARCKS) correlated with modulation of PKC activity in these cells, and direct peptide inhibition of MARCKS inhibited apoE secretion, implicating MARCKS as a downstream effector of PKC in apoE secretion. Comparison with other secreted proteins indicated that PKC similarly regulated secretion of matrix metalloproteinase 9 and chitinase-3-like-1 protein but differentially affected the secretion of other proteins. In conclusion, PKC regulates the secretion of apoE from primary human macrophages. PMID:23288845

  5. Distinct roles of apolipoprotein components within the trypanosome lytic factor complex revealed in a novel transgenic mouse model.

    PubMed

    Molina-Portela, Maria Pilar; Samanovic, Marie; Raper, Jayne

    2008-08-01

    Humans express a unique subset of high-density lipoproteins (HDLs) called trypanosome lytic factors (TLFs) that kill many Trypanosoma parasite species. The proteins apolipoprotein (apo) A-I, apoL-I, and haptoglobin-related protein, which are involved in TLF structure and function, were expressed through the introduction of transgenes in mice to explore their physiological roles in vivo. Transgenic expression of human apolipoprotein L-I alone conferred trypanolytic activity in vivo. Coexpression of human apolipoprotein A-I and haptoglobin-related protein (Hpr) had an effect on the integration of apolipoprotein L-I into HDL, and both proteins were required to increase the specific activity of TLF, which was measurable in vitro. Unexpectedly, truncated apolipoprotein L-I devoid of the serum resistance gene interacting domain, which was previously shown to kill human infective trypanosomes, was not trypanolytic in transgenic mice despite being coexpressed with human apolipoprotein A-I and Hpr and incorporated into HDLs. We conclude that all three human apolipoproteins act cooperatively to achieve maximal killing capacity and that truncated apolipoprotein L-I does not function in transgenic animals. PMID:18606856

  6. Modified Apolipoprotein (apo) A-I by Artificial Sweetener Causes Severe Premature Cellular Senescence and Atherosclerosis with Impairment of Functional and Structural Properties of apoA-I in Lipid-Free and Lipid-Bound State

    PubMed Central

    Jang, Wookju; Jeoung, Nam Ho; Cho, Kyung-Hyun

    2011-01-01

    Long-term consumption of artificial sweeteners (AS) has been the recent focus of safety concerns. However, the potential risk of the AS in cardiovascular disease and lipoprotein metabolism has not been investigated sufficiently. We compared the influence of AS (aspartame, acesulfame K, and saccharin) and fructose in terms of functional and structural correlations of apolipoprotein (apo) A-I and high-density lipoproteins (HDL), which have atheroprotective effects. Long-term treatment of apoA-I with the sweetener at physiological concentration (3 mM for 168 h) resulted in loss of antioxidant and phospholipid binding activities with modification of secondary structure. The AS treated apoA-I exhibited proteolytic cleavage to produce 26 kDa-fragment. They showed pro-atherogenic properties in acetylated LDL phagocytosis of macrophages. Each sweetener alone or sweetener-treated apoA-I caused accelerated senescence in human dermal fibroblasts. These results suggest that long-term consumption of AS might accelerate atherosclerosis and senescence via impairment of function and structure of apoA-I and HDL. PMID:21533907

  7. Modified apolipoprotein (apo) A-I by artificial sweetener causes severe premature cellular senescence and atherosclerosis with impairment of functional and structural properties of apoA-I in lipid-free and lipid-bound state.

    PubMed

    Jang, Wookju; Jeoung, Nam Ho; Cho, Kyung-Hyun

    2011-05-01

    Long-term consumption of artificial sweeteners (AS) has been the recent focus of safety concerns. However, the potential risk of the AS in cardiovascular disease and lipoprotein metabolism has not been investigated sufficiently. We compared the influence of AS (aspartame, acesulfame K, and saccharin) and fructose in terms of functional and structural correlations of apolipoprotein (apo) A-I and high-density lipoproteins (HDL), which have atheroprotective effects. Long-term treatment of apoA-I with the sweetener at physiological concentration (3 mM for 168 h) resulted in loss of antioxidant and phospholipid binding activities with modification of secondary structure. The AS treated apoA-I exhibited proteolytic cleavage to produce 26 kDa-fragment. They showed pro-atherogenic properties in acetylated LDL phagocytosis of macrophages. Each sweetener alone or sweetener-treated apoA-I caused accelerated senescence in human dermal fibroblasts. These results suggest that long-term consumption of AS might accelerate atherosclerosis and senescence via impairment of function and structure of apoA-I and HDL. PMID:21533907

  8. Levels and changes of HDL cholesterol and apolipoprotein A-I in relation to risk of cardiovascular events among statin-treated patients; a meta-analysis

    PubMed Central

    Boekholdt, S. Matthijs; Arsenault, Benoit J.; Hovingh, G. Kees; Mora, Samia; Pedersen, Terje R.; LaRosa, John C.; Welch, K.M.A.; Amarenco, Pierre; DeMicco, David A.; Tonkin, Andrew M.; Sullivan, David R.; Kirby, Adrienne; Colhoun, Helen M.; Hitman, Graham A.; Betteridge, D. John; Durrington, Paul N.; Clearfield, Michael B.; Downs, John R.; Gotto, Antonio M.; Ridker, Paul M.; Kastelein, John J.P.

    2013-01-01

    Background It is unclear whether levels of high-density lipoprotein cholesterol (HDL-C) or apolipoprotein A-I (apoA-I) remain inversely associated with cardiovascular risk among patients who achieve very low levels of low-density lipoprotein cholesterol (LDL-C) on statin therapy. It is also unknown whether a rise in HDL-C or apoA-I after initiation of statin therapy is associated with a reduced cardiovascular risk. Methods and results We performed a meta-analysis of 8 statin trials in which lipids and apolipoproteins were determined in all study participants at baseline and at 1-year follow-up. Individual patient data were obtained for 38,153 trial participants allocated to statin therapy, of whom 5387 suffered a major cardiovascular event. HDL-C levels were associated with a reduced risk of major cardiovascular events (adjusted hazard ratio 0.83, 95%CI 0.81–0.86 per 1 standard deviation increment), as were apoA-I levels (HR 0.79, 95%CI 0.72–0.82). This association was also observed among patients achieving on-statin LDL-C levels < 50 mg/dL. An increase of HDL-C was not associated with reduced cardiovascular risk (HR 0.98, 95%CI 0.94–1.01 per 1 standard deviation increment), whereas a rise in apoA-I was (HR 0.93, 95%CI 0.90–0.97). Conclusions Among patients treated with statin therapy, HDL-C and apoA-I levels were strongly associated with a reduced cardiovascular risk, even among those achieving very low LDL-C. An apoA-I increase was associated with a reduced risk of major cardiovascular events, whereas for HDL-C this was not the case. These findings suggest that therapies that increase apoA-I concentration require further exploration with regard to cardiovascular risk reduction. PMID:23965489

  9. Apolipoprotein A-I Mimetic Peptide D-4F Reduces Cardiac Hypertrophy and Improves Apolipoprotein A-I-Mediated Reverse Cholesterol Transport From Cardiac Tissue in LDL Receptor-null Mice Fed a Western Diet.

    PubMed

    Han, Jie; Zhang, Song; Ye, Ping; Liu, Yong-Xue; Qin, Yan-Wen; Miao, Dong-Mei

    2016-05-01

    Epidemiological studies have suggested that hypercholesterolemia is an independent determinant of increased left ventricular (LV) mass. Because high-density lipoprotein and its major protein apolipoprotein A-I (apoA-I) mediate reverse cholesterol transport (RCT) and have cardiac protective effects, we hypothesized that the apoA-I mimetic peptide D-4F could promote RCT in cardiac tissue and decrease cardiac hypertrophy induced by hypercholesterolemia. Low-density lipoprotein receptor-null mice were fed by a Western diet for 18 weeks and then randomized to receive water, or D-4F 0.3 mg/mL, or D-4F 0.5 mg/mL added to drinking water for 6 weeks. After D-4F administration, an increase in high-density lipoprotein cholesterol and a decrease in low-density lipoprotein cholesterol, total cholesterol, and triglyceride in a trend toward dose-responsivity were found in cardiac tissue. Ultrasound biomicroscopy revealed a reduction in LV posterior wall end-diastolic dimension, and an increase in mitral valve E/A ratio and LV ejection fraction. Hematoxylin-eosin staining showed reduced LV wall thickness and myocardial cell diameter. The protein levels of ABCA1 and LXRα were elevated in cardiac tissue of D-4F treated mice compared with the controls (P < 0.05). These results demonstrated that D-4F treatment reduced cardiac hypertrophy, and improved cardiac performance in low-density lipoprotein receptor-null mice fed a Western diet, presumably through the LXRα-ABCA1 pathway associated with enhanced myocardial RCT. PMID:26828321

  10. Estimation of Hardy-Weinberg and pairwise disequilibrium in the apolipoprotein AI-CIII-AIV gene cluster.

    PubMed Central

    Haviland, M B; Kessling, A M; Davignon, J; Sing, C F

    1991-01-01

    Departures from Hardy-Weinberg (HW) equilibria and pairwise disequilibria were estimated in a sample of unrelated healthy individuals typed for six RFLPs in the apo AI-CIII-AIV gene region. The sample was composed of males and females, selected for health, from two populations, those of exclusively French-Canadian (FC) and those of some non-French-Canadian (NFC) ancestry. An approach suggested by Weir and Cockerham, which includes estimates of nonrandom association (disequilibria) between three and four alleles at two loci as well as the traditional associations between two alleles, at two loci was used. The pattern of departures from HW equilibria suggested that the genetic structures of the FC and NFC are different. Departure from HW equilibrium at an RFLP locus could not be predicted from information about other loci in the same gene region. Nonrandom associations were also evident from the pairwise analyses. Two pairs of loci had significant diallelic disequilibria, while two other pairs had significant triallelic disequilibria. All of the RFLP pairs had at least one measure of disequilibrium at its maximum value determined by allele frequencies. Inferences about pairwise disequilibria depended on the statistical approach used. Sizes of the pairwise disequilibria were not correlated with the physical distance between loci. The impact of these disequilibria on RFLP-phenotype association studies is discussed. PMID:1678249

  11. ITRAQ-based quantitative proteomics reveals apolipoprotein A-I and transferrin as potential serum markers in CA19-9 negative pancreatic ductal adenocarcinoma.

    PubMed

    Lin, Chao; Wu, Wen-Chuan; Zhao, Guo-Chao; Wang, Dan-Song; Lou, Wen-Hui; Jin, Da-Yong

    2016-08-01

    Currently the diagnosis of pancreatic ductal adenocarcinoma (PDAC) relies on CA19-9 and radiological means, whereas some patients do not have elevated levels of CA19-9 secondary to pancreatic cancer. The purpose of this study was to identify potential serum biomarkers for CA19-9 negative PDAC.A total of 114 serum samples were collected from 3 groups: CA19-9 negative PDAC patients (n = 34), CA19-9 positive PDAC patients (n = 44), and healthy volunteers (n = 36), whereas the first 12 samples from each group were used for isobaric tags for relative and absolute quantitation (iTRAQ) analysis. Thereafter, candidate biomarkers were selected for validation by enzyme-linked immunosorbent assay (ELISA) with the rest specimens.Using the iTRAQ approach, a total of 5 proteins were identified as significantly different between CA19-9 negative PDAC patients and healthy subjects according to our defined criteria. Apolipoprotein A-I (APOA-I) and transferrin (TF) were selected to validate the proteomic results by ELISA in a further 78 serum specimens. It revealed that TF significantly correlated with the degree of histological differentiation (P = 0.042), and univariate and multivariate analyses indicated that TF is an independent prognostic factor for survival (hazard ratio, 0.302; 95% confidence interval, 0.118-0.774; P = 0.013) of patients with PDAC after curative surgery.ITRAQ-based quantitative proteomics revealed that APOA-I and TF may be potential CA19-9 negative PDAC serum markers. PMID:27495108

  12. ITRAQ-based quantitative proteomics reveals apolipoprotein A-I and transferrin as potential serum markers in CA19-9 negative pancreatic ductal adenocarcinoma

    PubMed Central

    Lin, Chao; Wu, Wen-Chuan; Zhao, Guo-Chao; Wang, Dan-Song; Lou, Wen-Hui; Jin, Da-Yong

    2016-01-01

    Abstract Currently the diagnosis of pancreatic ductal adenocarcinoma (PDAC) relies on CA19-9 and radiological means, whereas some patients do not have elevated levels of CA19-9 secondary to pancreatic cancer. The purpose of this study was to identify potential serum biomarkers for CA19-9 negative PDAC. A total of 114 serum samples were collected from 3 groups: CA19-9 negative PDAC patients (n = 34), CA19-9 positive PDAC patients (n = 44), and healthy volunteers (n = 36), whereas the first 12 samples from each group were used for isobaric tags for relative and absolute quantitation (iTRAQ) analysis. Thereafter, candidate biomarkers were selected for validation by enzyme-linked immunosorbent assay (ELISA) with the rest specimens. Using the iTRAQ approach, a total of 5 proteins were identified as significantly different between CA19-9 negative PDAC patients and healthy subjects according to our defined criteria. Apolipoprotein A-I (APOA-I) and transferrin (TF) were selected to validate the proteomic results by ELISA in a further 78 serum specimens. It revealed that TF significantly correlated with the degree of histological differentiation (P = 0.042), and univariate and multivariate analyses indicated that TF is an independent prognostic factor for survival (hazard ratio, 0.302; 95% confidence interval, 0.118–0.774; P = 0.013) of patients with PDAC after curative surgery. ITRAQ-based quantitative proteomics revealed that APOA-I and TF may be potential CA19-9 negative PDAC serum markers. PMID:27495108

  13. An experimentally robust model of monomeric apolipoprotein A-I created from a chimera of two X-ray structures and molecular dynamics simulations.

    PubMed

    Segrest, Jere P; Jones, Martin K; Shao, Baohai; Heinecke, Jay W

    2014-12-01

    High-density lipoprotein (HDL) retards atherosclerosis by accepting cholesterol from the artery wall. However, the structure of the proposed acceptor, monomeric apolipoprotein A-I (apoA-I), the major protein of HDL, is poorly understood. Two published models for monomeric apoA-I used cross-linking distance constraints to derive best fit conformations. This approach has limitations. (i) Cross-linked peptides provide no information about secondary structure. (ii) A protein chain can be folded in multiple ways to create a best fit. (iii) Ad hoc folding of a secondary structure is unlikely to produce a stable orientation of hydrophobic and hydrophilic residues. To address these limitations, we used a different approach. We first noted that the dimeric apoA-I crystal structure, (Δ185-243)apoA-I, is topologically identical to a monomer in which helix 5 forms a helical hairpin, a monomer with a hydrophobic cleft running the length of the molecule. We then realized that a second crystal structure, (Δ1-43)apoA-I, contains a C-terminal structure that fits snuggly via aromatic and hydrophobic interactions into the hydrophobic cleft. Consequently, we combined these crystal structures into an initial model that was subjected to molecular dynamics simulations. We tested the initial and simulated models and the two previously published models in three ways: against two published data sets (domains predicted to be helical by H/D exchange and six spin-coupled residues) and against our own experimentally determined cross-linking distance constraints. We note that the best fit simulation model, superior by all tests to previously published models, has dynamic features of a molten globule with interesting implications for the functions of apoA-I. PMID:25423138

  14. Kinetic and thermodynamic analyses of spontaneous exchange between high-density lipoprotein-bound and lipid-free apolipoprotein A-I.

    PubMed

    Handa, Daisuke; Kimura, Hitoshi; Oka, Tatsuya; Takechi, Yuki; Okuhira, Keiichiro; Phillips, Michael C; Saito, Hiroyuki

    2015-02-01

    It is thought that apolipoprotein A-I (apoA-I) spontaneously exchanges between high-density lipoprotein (HDL)-bound and lipid-free states, which is relevant to the occurrence of preβ-HDL particles in plasma. To improve our understanding of the mechanistic basis for this phenomenon, we performed kinetic and thermodynamic analyses for apoA-I exchange between discoidal HDL-bound and lipid-free forms using fluorescence-labeled apoA-I variants. Gel filtration experiments demonstrated that addition of excess lipid-free apoA-I to discoidal HDL particles promotes exchange of apoA-I between HDL-associated and lipid-free pools without alteration of the steady-state HDL particle size. Kinetic analysis of time-dependent changes in NBD fluorescence upon the transition of NBD-labeled apoA-I from HDL-bound to lipid-free state indicates that the exchange kinetics are independent of the collision frequency between HDL-bound and lipid-free apoA-I, in which the lipid binding ability of apoA-I affects the rate of association of lipid-free apoA-I with the HDL particles and not the rate of dissociation of HDL-bound apoA-I. Thus, C-terminal truncations or mutations that reduce the lipid binding affinity of apoA-I strongly impair the transition of lipid-free apoA-I to the HDL-bound state. Thermodynamic analysis of the exchange kinetics demonstrated that the apoA-I exchange process is enthalpically unfavorable but entropically favorable. These results explain the thermodynamic basis of the spontaneous exchange reaction of apoA-I associated with HDL particles. The altered exchangeability of dysfunctional apoA-I would affect HDL particle rearrangement, leading to perturbed HDL metabolism. PMID:25564321

  15. Apolipoprotein AI tertiary structures determine stability and phospholipid-binding activity of discoidal high-density lipoprotein particles of different sizes

    SciTech Connect

    Chen, Bin; Ren, Xuefeng; Neville, Tracey; Jerome, W. Gray; Hoyt, David W.; Sparks, Daniel L.; Ren, Gang; Wang, Jianjun

    2009-05-18

    Human high-density lipoprotein (HDL) plays a key role in the reverse cholesterol transport pathway that delivers excess cholesterol back to the liver for clearance. In vivo, HDL particles vary in size, shape and biological function. The discoidal HDL is a 140-240 kDa, disk-shaped intermediate of mature HDL. During mature spherical HDL formation, discoidal HDLs play a key role in loading cholesterol ester onto the HDL particles by activating the enzyme, lecithin:cholesterol acyltransferase (LCAT). One of the major problems for high-resolution structural studies of discoidal HDL is the difficulty in obtaining pure and, foremost, homogenous sample. We demonstrate here that the commonly used cholate dialysis method for discoidal HDL preparation usually contains 5-10% lipid-poor apoAI that significantly interferes with the high-resolution structural analysis of discoidal HDL using biophysical methods. Using an ultracentrifugation method, we quickly removed lipid-poor apoAI. We also purified discoidal reconstituted HDL (rHDL) into two pure discoidal HDL species of different sizes that are amendable for high-resolution structural studies. A small rHDL has a diameter of 7.6 nm, and a large rHDL has a diameter of 9.8 nm. We show that these two different sizes of discoidal HDL particles display different stability and phospholipid-binding activity. Interestingly, these property/functional differences are independent from the apoAI -helical secondary structure, but are determined by the tertiary structural difference of apoAI on different discoidal rHDL particles, as evidenced by two-dimensional NMR and negative stain electron microscopy data. Our result further provides the first high-resolution NMR data, demonstrating a promise of structural determination of discoidal HDL at atomic resolution using a combination of NMR and other biophysical techniques.

  16. Multiple apolipoprotein kinetics measured in human HDL by high-resolution/accurate mass parallel reaction monitoring.

    PubMed

    Singh, Sasha A; Andraski, Allison B; Pieper, Brett; Goh, Wilson; Mendivil, Carlos O; Sacks, Frank M; Aikawa, Masanori

    2016-04-01

    Endogenous labeling with stable isotopes is used to study the metabolism of proteins in vivo. However, traditional detection methods such as GC/MS cannot measure tracer enrichment in multiple proteins simultaneously, and multiple reaction monitoring MS cannot measure precisely the low tracer enrichment in slowly turning-over proteins as in HDL. We exploited the versatility of the high-resolution/accurate mass (HR/AM) quadrupole Orbitrap for proteomic analysis of five HDL sizes. We identified 58 proteins in HDL that were shared among three humans and that were organized into five subproteomes according to HDL size. For seven of these proteins, apoA-I, apoA-II, apoA-IV, apoC-III, apoD, apoE, and apoM, we performed parallel reaction monitoring (PRM) to measure trideuterated leucine tracer enrichment between 0.03 to 1.0% in vivo, as required to study their metabolism. The results were suitable for multicompartmental modeling in all except apoD. These apolipoproteins in each HDL size mainly originated directly from the source compartment, presumably the liver and intestine. Flux of apolipoproteins from smaller to larger HDL or the reverse contributed only slightly to apolipoprotein metabolism. These novel findings on HDL apolipoprotein metabolism demonstrate the analytical breadth and scope of the HR/AM-PRM technology to perform metabolic research. PMID:26862155

  17. Apolipoprotein A-I in Labeo rohita: Cloning and functional characterisation reveal its broad spectrum antimicrobial property, and indicate significant role during ectoparasitic infection.

    PubMed

    Mohapatra, Amruta; Karan, Sweta; Kar, Banya; Garg, L C; Dixit, A; Sahoo, P K

    2016-08-01

    Apolipoprotein A-I (ApoA-I) is the most abundant and multifunctional high-density lipoprotein (HDL) having a major role in lipid transport and potent antimicrobial activity against a wide range of microbes. In this study, a complete CDS of 771 bp of Labeo rohita (rohu) ApoA-I (LrApoA-I) encoding a protein of 256 amino acids was amplified, cloned and sequenced. Tissue specific transcription analysis of LrApoA-I revealed its expression in a wide range of tissues, with a very high level of expression in liver and spleen. Ontogenic study of LrApoA-I expression showed presence of transcripts in milt and 3 h post-fertilization onwards in the larvae. The expression kinetics of LrApoA-I was studied upon infection with three different types of pathogens to elucidate its functional significance. Its expression was found to be up-regulated in the anterior kidney of L. rohita post-infection with Aeromonas hydrophila. Similarly following poly I:C (poly inosinic:cytidylic) stimulation, the transcript levels increased in both the anterior kidney and liver tissues. Significant up-regulation of LrApoA-I expression was observed in skin, mucous, liver and anterior kidney of the fish challenged with the ectoparasite Argulus siamensis. Immunomodulatory effect of recombinant LrApoA-I (rApoA-I) produced in Escherichia coli was demonstrated against A. hydrophila challenge in vivo. L. rohita administered with rApoA-I at a dose of 100 μg exhibited significantly higher protection (∼55%) upon challenge with A. hydrophila 12 h post-administration of the protein, in comparison to that observed in control group, along with higher level of expression of immune-related genes. The heightened expression of ApoA-I observed post-infection reflected its involvement in immune responses against a wide range of infections including bacterial, viral as well as parasitic pathogens. Our results also suggest the possibility of using rApoA-I as an immunostimulant, particularly rendering protection

  18. Trimerized apolipoprotein A-I (TripA) forms lipoproteins, activates lecithin: cholesterol acyltransferase, elicits lipid efflux, and is transported through aortic endothelial cells.

    PubMed

    Ohnsorg, Pascale M; Mary, Jean-Luc; Rohrer, Lucia; Pech, Michael; Fingerle, Jürgen; von Eckardstein, Arnold

    2011-12-01

    Apolipoprotein A-I (apoA-I) exerts many potentially anti-atherogenic properties and is therefore attractive for prevention and therapy of coronary heart disease. Since induction of apoA-I production by small molecules has turned out as difficult, application of exogenous apoA-I is pursued as an alternative therapeutic option. To counteract fast renal filtration of apoA-I, a trimeric high-molecular weight variant of apoA-I (TripA) was produced by recombinant technology. We compared TripA and apoA-I for important properties in reverse cholesterol transport. Reconstituted high-density lipoproteins (rHDL) containing TripA or apoA-I together with palmitoyl-2-oleyl-phosphatidylcholine (POPC) differed slightly by size. Compared to apoA-I, TripA activated lecithin:cholesterol acyltransferase (LCAT) with similar maximal velocity but concentration leading to half maximal velocity was slightly reduced (K(m)=2.1±0.3μg/mL vs. 0.59±0.06μg/mL). Both in the lipid-free form and as part of rHDL, TripA elicited cholesterol efflux from THP1-derived macrophages with similar kinetic parameters and response to liver-X-receptor activation as apoA-I. Lipid-free TripA is bound and transported by aortic endothelial cells through mechanisms which are competed by apoA-I and TripA and inhibited by knock-down of ATP-binding cassette transporter (ABC) A1. Pre-formed TripA/POPC particles were bound and transported by endothelial cells through mechanisms which are competed by excess native HDL as well as reconstituted HDL containing either apoA-I or TripA and which involve ABCG1 and scavenger receptor B1 (SR-BI). In conclusion, apoA-I and TripA show similar in vitro properties which are important for reverse cholesterol transport. These findings are important for further development of TripA as an anti-atherosclerotic drug. PMID:21930241

  19. Gene-centric Association Signals for Lipids and Apolipoproteins Identified via the HumanCVD BeadChip

    PubMed Central

    Talmud, Philippa J.; Drenos, Fotios; Shah, Sonia; Shah, Tina; Palmen, Jutta; Verzilli, Claudio; Gaunt, Tom R.; Pallas, Jacky; Lovering, Ruth; Li, Kawah; Casas, Juan Pablo; Sofat, Reecha; Kumari, Meena; Rodriguez, Santiago; Johnson, Toby; Newhouse, Stephen J.; Dominiczak, Anna; Samani, Nilesh J.; Caulfield, Mark; Sever, Peter; Stanton, Alice; Shields, Denis C.; Padmanabhan, Sandosh; Melander, Olle; Hastie, Claire; Delles, Christian; Ebrahim, Shah; Marmot, Michael G.; Smith, George Davey; Lawlor, Debbie A.; Munroe, Patricia B.; Day, Ian N.; Kivimaki, Mika; Whittaker, John; Humphries, Steve E.; Hingorani, Aroon D.

    2009-01-01

    Blood lipids are important cardiovascular disease (CVD) risk factors with both genetic and environmental determinants. The Whitehall II study (n = 5592) was genotyped with the gene-centric HumanCVD BeadChip (Illumina). We identified 195 SNPs in 16 genes/regions associated with 3 major lipid fractions and 2 apolipoprotein components at p < 10−5, with the associations being broadly concordant with prior genome-wide analysis. SNPs associated with LDL cholesterol and apolipoprotein B were located in LDLR, PCSK9, APOB, CELSR2, HMGCR, CETP, the TOMM40-APOE-C1-C2-C4 cluster, and the APOA5-A4-C3-A1 cluster; SNPs associated with HDL cholesterol and apolipoprotein AI were in CETP, LPL, LIPC, APOA5-A4-C3-A1, and ABCA1; and SNPs associated with triglycerides in GCKR, BAZ1B, MLXIPL, LPL, and APOA5-A4-C3-A1. For 48 SNPs in previously unreported loci that were significant at p < 10−4 in Whitehall II, in silico analysis including the British Women's Heart and Health Study, BRIGHT, ASCOT, and NORDIL studies (total n > 12,500) revealed previously unreported associations of SH2B3 (p < 2.2 × 10−6), BMPR2 (p < 2.3 × 10−7), BCL3/PVRL2 (flanking APOE; p < 4.4 × 10−8), and SMARCA4 (flanking LDLR; p < 2.5 × 10−7) with LDL cholesterol. Common alleles in these genes explained 6.1%–14.7% of the variance in the five lipid-related traits, and individuals at opposite tails of the additive allele score exhibited substantial differences in trait levels (e.g., >1 mmol/L in LDL cholesterol [∼1 SD of the trait distribution]). These data suggest that multiple common alleles of small effect can make important contributions to individual differences in blood lipids potentially relevant to the assessment of CVD risk. These genes provide further insights into lipid metabolism and the likely effects of modifying the encoded targets therapeutically. PMID:19913121

  20. Several Human Liver Cell Expressed Apolipoproteins Complement HCV Virus Production with Varying Efficacy Conferring Differential Specific Infectivity to Released Viruses

    PubMed Central

    Doepke, Mandy; Vieyres, Gabrielle; Todt, Daniel; Wölk, Benno; Vondran, Florian W. R.; Geffers, Robert; Lauber, Chris; Kaderali, Lars; Penin, François; Pietschmann, Thomas

    2015-01-01

    Apolipoprotein E (ApoE), an exchangeable apolipoprotein, is necessary for production of infectious Hepatitis C virus (HCV) particles. However, ApoE is not the only liver-expressed apolipoprotein and the role of other apolipoproteins for production of infectious HCV progeny is incompletely defined. Therefore, we quantified mRNA expression of human apolipoproteins in primary human hepatocytes. Subsequently, cDNAs encoding apolipoproteins were expressed in 293T/miR-122 cells to explore if they complement HCV virus production in cells that are non-permissive due to limiting endogenous levels of human apolipoproteins. Primary human hepatocytes expressed high mRNA levels of ApoA1, A2, C1, C3, E, and H. ApoA4, A5, B, D, F, J, L1, L2, L3, L4, L6, M, and O were expressed at intermediate levels, and C2, C4, and L5 were not detected. All members of the ApoA and ApoC family of lipoproteins complemented HCV virus production in HCV transfected 293T/miR-122 cells, albeit with significantly lower efficacy compared with ApoE. In contrast, ApoD expression did not support production of infectious HCV. Specific infectivity of released particles complemented with ApoA family members was significantly lower compared with ApoE. Moreover, the ratio of extracellular to intracellular infectious virus was significantly higher for ApoE compared to ApoA2 and ApoC3. Since apolipoproteins complementing HCV virus production share amphipathic alpha helices as common structural features we altered the two alpha helices of ApoC1. Helix breaking mutations in both ApoC1 helices impaired virus assembly highlighting a critical role of alpha helices in apolipoproteins supporting HCV assembly. In summary, various liver expressed apolipoproteins with amphipathic alpha helices complement HCV virus production in human non liver cells. Differences in the efficiency of virus assembly, the specific infectivity of released particles, and the ratio between extracellular and intracellular infectivity point to

  1. Protein polymorphism of a human plasma apolipoprotein D antigenic epitope.

    PubMed

    Camato, R; Marcel, Y L; Milne, R W; Lussier-Cacan, S; Weech, P K

    1989-06-01

    Based on our previous observation that monoclonal antibody anti-apoD-4E11 reacted with several HDL proteins we studied them further with three questions in mind: i) is there common protein polymorphism in healthy individuals? ii) how many proteins are present and what are their characteristics? iii) are they all apolipoproteins and do they have the same lipoprotein distribution as apoD? Isolated, delipidated apoD was used as a standard for radioimmunometric assay of plasma with antibody 4E11. The antigen varied from 3 to 11 mumol-equivalents of apoD per liter of plasma (equivalent to 5-20 mg apoD/dl plasma) with means of 6.1 and 6.8 mumol/l in men and women, respectively. Two-dimensional electrophoresis of plasma found up to eight 4E11-antigenic-proteins of different Mr, each heterogeneous in pI. All plasmas tested contained apoD and an Mr 38,000 antigen, the latter being the most immunoreactive. Six proteins of Mr 70,000-94,000 were found, but the number varied between subjects. Eighty nine percent of the plasma antigen was associated with lipoproteins: 83% with HDL and VHDL, 5% with LDL and VLDL. Lipoproteins of all sizes, separated by polyacrylamide gradient gel electrophoresis, contained the antigen. ApoD was almost the only 4E11-antigen in LDL, and was in two states: the one free, the other an apoD-apoB mixed disulfide complex. The apparent proportions of higher Mr antigens increased with increasing lipoprotein density, and the proportion of apoD decreased reciprocally. None of these 4E11-antigenic-proteins cross-reacted with antiserum to retinol-binding protein. PMID:2477480

  2. Effect of lipid composition and packing on the adsorption of apolipoproteins to lipid monolayers

    SciTech Connect

    Ibdah, J.A.; Lund-Katz, S.; Phillips, M.C.

    1987-05-01

    The monolayer system has been used to study the effects of lipoprotein surface lipid composition and packing on the affinities of apolipoproteins for the surfaces of lipoprotein particles. The adsorption of apolipoproteins injected beneath lipid monolayers prepared with pure lipids or lipoprotein surface lipids is evaluated by monitoring the surface pressure of the film and the surface concentration (Gamma) of /sup 14/C-labelled apolipoprotein. At a given initial film pressure (..pi../sub i/) there is a higher adsorption of human apo A-I to unsaturated phosphatidylcholine (PC) monolayers compared to saturated PC monolayers (e.g., at ..pi../sub i/ = 10 mN/m, Gamma = 0.35 and 0.06 mg/m/sup 2/ for egg PC and distearoyl PC, respectively, with 3 x 10/sup -4/ mg/ml apo A-I in the subphase). In addition, adsorption of apo A-I is less to an egg sphingomyelin monolayer than to an egg PC monolayer. The adsorption of apo A-I to PC monolayers is decreased by addition of cholesterol. Generally, apo A-I adsorption diminishes as the lipid molecular area decreases. Apo A-I adsorbs more to monolayers prepared with HDL/sub 3/ surface lipids than with LDL surface lipids. These studies suggest that lipoprotein surface lipid composition and packing are crucial factors influencing the transfer and exchange of apolipoproteins among various lipoprotein classes during metabolism of lipoprotein particles.

  3. Lipoprotein remodeling generates lipid-poor apolipoprotein A-I particles in human interstitial fluid

    PubMed Central

    Olszewski, Waldemar L.; Hattori, Hiroaki; Miller, Irina P.; Kujiraoka, Takeshi; Oka, Tomoichiro; Iwasaki, Tadao; Nanjee, M. Nazeem

    2013-01-01

    Although much is known about the remodeling of high density lipoproteins (HDLs) in blood, there is no information on that in interstitial fluid, where it might have a major impact on the transport of cholesterol from cells. We incubated plasma and afferent (prenodal) peripheral lymph from 10 healthy men at 37°C in vitro and followed the changes in HDL subclasses by nondenaturing two-dimensional crossed immunoelectrophoresis and size-exclusion chromatography. In plasma, there was always initially a net conversion of small pre-β-HDLs to cholesteryl ester (CE)-rich α-HDLs. By contrast, in lymph, there was only net production of pre-β-HDLs from α-HDLs. Endogenous cholesterol esterification rate, cholesteryl ester transfer protein (CETP) concentration, CE transfer activity, phospholipid transfer protein (PLTP) concentration, and phospholipid transfer activity in lymph averaged 5.0, 10.4, 8.2, 25.0, and 82.0% of those in plasma, respectively (all P < 0.02). Lymph PLTP concentration, but not phospholipid transfer activity, was positively correlated with that in plasma (r = +0.63, P = 0.05). Mean PLTP-specific activity was 3.5-fold greater in lymph, reflecting a greater proportion of the high-activity form of PLTP. These findings suggest that cholesterol esterification rate and PLTP specific activity are differentially regulated in the two matrices in accordance with the requirements of reverse cholesterol transport, generating lipid-poor pre-β-HDLs in the extracellular matrix for cholesterol uptake from neighboring cells and converting pre-β-HDLs to α-HDLs in plasma for the delivery of cell-derived CEs to the liver. PMID:23233540

  4. Characterization of disulfide-linked heterodimers containing apolipoprotein D in human plasma lipoproteins.

    PubMed

    Blanco-Vaca, F; Via, D P; Yang, C Y; Massey, J B; Pownall, H J

    1992-12-01

    Human plasma apolipoprotein (apo) D is a glycoprotein with an apparent molecular weight of 29,000 M(r). It is present, mainly, in high density lipoproteins (HDL) and very high density lipoproteins (VHDL). Western blot analysis of HDL and VHDL using rabbit antibodies to human apoD revealed major immunoreactive bands at 29,000 and 38,000 M(r), with minor bands ranging from 50,000 to and 80,000 M(r). Only the 29,000 M(r) band corresponding to apoD remained when the electrophoresis was conducted under reducing conditions, demonstrating that apoD is cross-linked to other proteins via disulfide bonds. The broad pattern of immunoreactivity was also observed under nonreducing conditions when the blood was collected into a solution of sulfhydryl-trapping reagents, or when these reagents were added to the isolated lipoproteins. These results indicated that the disulfide bonds were not the result of disulfide exchange during the experimental procedures. On the basis of amino acid sequencing and reactions to antibodies, the 38,000 M(r) band was identified as an apoD-apoA-II heterodimer. The apoD-apoA-II was also demonstrated in plasma. In both HDL and plasma, the apoD-apoA-II heterodimer constituted the major form of apoD. Disulfide-linked heterodimers of apoD and apoB-100 were also found in low and very low density lipoproteins, and in whole plasma. It is concluded that a fraction of human apoD, like other cysteine-containing apolipoproteins, exists as a disulfide-linked heterodimer with other apolipoproteins in all major human lipoprotein fractions. PMID:1479288

  5. Analysis of cell surface alterations in Legionella pneumophila cells treated with human apolipoprotein E.

    PubMed

    Palusinska-Szysz, Marta; Zdybicka-Barabas, Agnieszka; Cytryńska, Małgorzata; Wdowiak-Wróbel, Sylwia; Chmiel, Elżbieta; Gruszecki, Wiesław I

    2015-03-01

    Binding of human apolipoprotein E (apoE) to Legionella pneumophila lipopolysaccharide was analysed at the molecular level by Fourier-transform infrared spectroscopy, thereby providing biophysical evidence for apoE-L. pneumophila lipopolysaccharide interaction. Atomic force microscopy imaging of apoE-exposed L. pneumophila cells revealed alterations in the bacterial cell surface topography and nanomechanical properties in comparison with control bacteria. The changes induced by apoE binding to lipopolysaccharide on the surface of L. pneumophila cells may participate in: (1) impeding the penetration of host cells by the bacteria; (2) suppression of pathogen intracellular growth and eventually; and (3) inhibition of the development of infection. PMID:25176171

  6. Apolipoprotein A-I coating of protamine–oligonucleotide nanoparticles increases particle uptake and transcytosis in an in vitro model of the blood–brain barrier

    PubMed Central

    Kratzer, Ingrid; Wernig, Karin; Panzenboeck, Ute; Bernhart, Eva; Reicher, Helga; Wronski, Robert; Windisch, Manfred; Hammer, Astrid; Malle, Ernst; Zimmer, Andreas; Sattler, Wolfgang

    2016-01-01

    Drug delivery to the brain is severely restricted by formation of tight junctions between adjacent brain capillary endothelial cells (BCEC). In the present study we have evaluated the effects of protamine–oligonucleotide nanoparticles (proticles) on the functional properties of primary porcine BCEC and characterized uptake and transcytosis of proticles by these cells. Proticles had no adverse effects on BCEC properties relevant to blood–brain barrier (BBB) function. Transcytosis of 125I-labeled proticles across polarized BCEC cultures occurred in a time- and concentration-dependent manner. As apolipoproteins were suggested to enhance cellular proticle uptake, proticle coating was performed with apoA-I, the major apolipoprotein component of high density lipoproteins. Adsorption of apoA-I on the surface of proticles resulted in significantly improved uptake and transcytosis properties as compared to uncoated proticles. ApoA-I coating enhanced proticle delivery to astrocytes in an in vitro model of the BBB almost twofold. Blocking of scavenger receptor class B, type I (the prime receptor for high density lipoprotein/apoA-I that is expressed on BCEC) reduced transcytosis of apoA-I-coated proticles to levels observed for uncoated proticles. Our data indicate that apoA-I-coating of proticles could be a feasible targeting technology to improve delivery across the BBB. PMID:17239472

  7. Human apolipoprotein A-II protects against diet-induced atherosclerosis in transgenic rabbits

    PubMed Central

    Wang, Yao; Niimi, Manabu; Nishijima, Kazutoshi; Waqar, Ahmed Bilal; Yu, Ying; Koike, Tomonari; Kitajima, Shuji; Liu, Enqi; Inoue, Tomohiro; Kohashi, Masayuki; Keyamura, Yuka; Yoshikawa, Tomohiro; Zhang, Jifeng; Ma, Loretta; Zha, Xiaohui; Watanabe, Teruo; Asada, Yujiro; Chen, Y. Eugene; Fan, Jianglin

    2013-01-01

    Objective Apolipoprotein A-II (apo A-II) is the second major apolipoprotein of HDLs, yet its pathophysiological roles in the development of atherosclerosis remain unknown. We aimed to examine whether apo A-II plays any role in atherogenesis and if so, to elucidate the mechanism involved. Methods and Results We compared the susceptibility of human apo A-II transgenic (Tg) rabbits to cholesterol diet-induced atherosclerosis with non-Tg littermate rabbits. Tg rabbits developed significantly less aortic and coronary atherosclerosis than their non-Tg littermates while total plasma cholesterol levels were similar. Atherosclerotic lesions of Tg rabbits were characterized by reduced macrophages and smooth muscle cells and apo A-II immunoreactive proteins were frequently detected in the lesions. Tg rabbits exhibited low levels of plasma CRP and blood leukocytes compared to non-Tg rabbits and HDLs of Tg rabbit plasma exerted stronger cholesterol efflux activity and inhibitory effects on the inflammatory cytokine expression by macrophages in vitro than HDLs isolated from non-Tg rabbits. In addition, β-VLDLs of Tg rabbits were less sensitive to copper-induced oxidation than β-VLDLs of non-Tg rabbits. Conclusions These results suggest that enrichment of apo A-II in HDL particles has atheroprotective effects and apo A-II may become a target for the treatment of atherosclerosis. PMID:23241412

  8. Effect of almond skin polyphenolics and quercetin on human LDL and apolipoprotein B-100 oxidation and conformation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Almond skin flavonoids (ASF) inhibit Cu2+-induced generation of conjugated dienes in low density lipoproteins (LDL). However, the effect of ASF on apolipoprotein B-100 oxidation and LDL conformation has not been explored. ASF (0.12-2.0 µmol/L gallic acid equivalents) were incubated with human LDL an...

  9. An experimental study on amelioration of dyslipidemia-induced atherosclesis by Clematichinenoside through regulating Peroxisome proliferator-activated receptor-α mediated apolipoprotein A-I, A-II and C-III.

    PubMed

    Liu, Chao; Guo, Qianqian; Lu, Mengchen; Li, Yunman

    2015-08-15

    Prevention or amelioration the prevalence of atherosclerosis has been an effective strategy in the management of cardiovascular diseases. The aim of the study was to scrutinize the effect of Clematichinenoside (AR) on dyslipidemia-induced atherosclerosis and explore its capability on expression of Peroxisome proliferator-activated receptor-α (PPAR-alpha), apolipoprotein A-I (APOA1) and A-II (APOA2), and suppression of apolipoprotein C-III (APOC3) genes and proteins. In the present study, we investigated atherosclerosis effect of AR using a combination of high-fat diet and balloon injury model in rabbits. The levels of biochemical indicators were evaluated in plasma, liver and HepG2 cells using immunoassay technology. In order to expose the underlying mechanism, we evaluated the regulation of PPAR-alpha, APOA1, APOA2 and APOC3 expressions by AR, and we further evaluated the interactions between them after transfection with shRNA (shPPAR-alpha) and, the action of PPAR-alpha in HepG2 cells. We could find that AR markedly promoted the PPAR-alpha transfer from cytoplasm to nucleus which resulted in the alteration of APOA1, APOA2 and APOC3 expressions in HepG2 cells. Moreover, AR significantly reduced total cholesterol, triglycerides and low-density lipoprotein cholesterol (LDL-C) levels, and elevated high-density lipoprotein cholesterol (HDL-C) level, which play an important role in dyslipidemia-induced atherosclerosis. In conclusion, AR ameliorated atherosclerosis via the regulation of hepatic lipid metabolism, and AR also contributed to the activation of PPAR-alpha, APOA1, APOA2 and APOC3. Therefore, AR could be a potential therapeutic agent in the treatment of atherosclerosis. PMID:25979856

  10. Retinoids increase human apolipoprotein A-11 expression through activation of the retinoid X receptor but not the retinoic acid receptor.

    PubMed Central

    Vu-Dac, N; Schoonjans, K; Kosykh, V; Dallongeville, J; Heyman, R A; Staels, B; Auwerx, J

    1996-01-01

    Considering the link between plasma high-density lipoprotein (HDL) cholesterol levels and a protective effect against coronary artery disease as well as the suggested beneficial effects of retinoids on the production of the major HDL apolipoprotein (apo), apo A-I, the goal of this study was to analyze the influence of retinoids on the expression of apo A-II, the other major HDL protein. Retinoic acid (RA) derivatives have a direct effect on hepatic apo A-II production, since all-trans (at) RA induces apo A-II mRNA levels and apo A-II secretion in primary cultures of human hepatocytes. In the HepG2 human hepatoblastoma cell line, both at-RA and 9-cis RA as well as the retinoid X receptor (RXR)-specific agonist LGD 1069, but not the RA receptor (RAR) agonist ethyl-p-[(E)-2-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthyl)-l-pro penyl]-benzoic acid (TTNPB), induce apo A-II mRNA levels. Transient-transfection experiments with a reporter construct driven by the human apo A-II gene promoter indicated that 9-cis RA and at-RA, as well as the RXR agonists LGD 1069 and LG 100268, induced apo A-II gene expression at the transcriptional level. Only minimal effects of the RAR agonist TTNPB were observed on the apo A-II promoter reporter construct. Unilateral deletions and site-directed mutagenesis identified the J site of the apo A-II promoter mediating the responsiveness to RA. This element contains two imperfect half-sites spaced by 1 oligonucleotide. Cotransfection assays in combination with the use of RXR or RAR agonists showed that RXR but not RAR transactivates the apo A-II promoter through this element. By contrast, RAR inhibits the inductive effects of RXR on the apo A-II J site in a dose-dependent fashion. Gel retardation assays demonstrated that RXR homodimers bind, although with a lower affinity than RAR-RXR heterodimers, to the AH-RXR response element. In conclusion, retinoids induce hepatic apo A-II production at the transcriptional level via the interaction of

  11. Orphan nuclear receptor Nur77 participates in human apolipoprotein A5 gene expression

    SciTech Connect

    Song, Kwang-Hoon

    2010-01-29

    The orphan nuclear receptor Nur77 (NR4A1) has been reported to play a crucial role in the modulation of diverse metabolic processes in liver. Here, we reported the identification of human apolipoprotein A5 (ApoA5), which implicated in lowering plasma triglyceride levels, as a novel target gene of Nur77. Nur77 induced the human ApoA5 promoter activity. Using 5'-deletion and mutagenesis of human ApoA5 promoter analysis and chromatin immunoprecipitation assays, it was shown that Nur77 directly regulated human ApoA5 gene expression by binding to a Nur77 response element (AAAGGTCA) located in the proximal human ApoA5 promoter region. In addition, we demonstrated that blocking of Nur77 transcriptional activity via overexpression of dominant negative Nur77 suppressed human ApoA5 promoter activity and mRNA expression in human hepatoma cells, HepG2. Taken together, our results demonstrated that Nur77 is a novel regulator of human ApoA5 gene expression and provide a new insight into the role of this orphan nuclear receptor in lipoprotein metabolism and triglyceride homeostasis.

  12. Glomerular autoimmune multicomponents of human lupus nephritis in vivo: α-enolase and annexin AI.

    PubMed

    Bruschi, Maurizio; Sinico, Renato Alberto; Moroni, Gabriella; Pratesi, Federico; Migliorini, Paola; Galetti, Maricla; Murtas, Corrado; Tincani, Angela; Madaio, Michael; Radice, Antonella; Franceschini, Franco; Trezzi, Barbara; Bianchi, Laura; Giallongo, Agata; Gatti, Rita; Tardanico, Regina; Scaloni, Andrea; D'Ambrosio, Chiara; Carnevali, Maria Luisa; Messa, Piergiorgio; Ravani, Pietro; Barbano, Giancarlo; Bianco, Beatrice; Bonanni, Alice; Scolari, Francesco; Martini, Alberto; Candiano, Giovanni; Allegri, Landino; Ghiggeri, Gian Marco

    2014-11-01

    Renal targets of autoimmunity in human lupus nephritis (LN) are unknown. We sought to identify autoantibodies and glomerular target antigens in renal biopsy samples from patients with LN and determine whether the same autoantibodies can be detected in circulation. Glomeruli were microdissected from biopsy samples of 20 patients with LN and characterized by proteomic techniques. Serum samples from large cohorts of patients with systemic lupus erythematosus (SLE) with and without LN and other glomerulonephritides were tested. Glomerular IgGs recognized 11 podocyte antigens, with reactivity varying by LN pathology. Notably, IgG2 autoantibodies against α-enolase and annexin AI were detected in 11 and 10 of the biopsy samples, respectively, and predominated over other autoantibodies. Immunohistochemistry revealed colocalization of α-enolase or annexin AI with IgG2 in glomeruli. High levels of serum anti-α-enolase (>15 mg/L) IgG2 and/or anti-annexin AI (>2.7 mg/L) IgG2 were detected in most patients with LN but not patients with other glomerulonephritides, and they identified two cohorts: patients with high anti-α-enolase/low anti-annexin AI IgG2 and patients with low anti-α-enolase/high anti-annexin AI IgG2. Serum levels of both autoantibodies decreased significantly after 12 months of therapy for LN. Anti-α-enolase IgG2 recognized specific epitopes of α-enolase and did not cross-react with dsDNA. Furthermore, nephritogenic monoclonal IgG2 (clone H147) derived from lupus-prone MRL-lpr/lpr mice recognized human α-enolase, suggesting homology between animal models and human LN. These data show a multiantibody composition in LN, where IgG2 autoantibodies against α-enolase and annexin AI predominate in the glomerulus and can be detected in serum. PMID:24790181

  13. Glomerular Autoimmune Multicomponents of Human Lupus Nephritis In Vivo: α-Enolase and Annexin AI

    PubMed Central

    Bruschi, Maurizio; Sinico, Renato Alberto; Moroni, Gabriella; Pratesi, Federico; Migliorini, Paola; Galetti, Maricla; Murtas, Corrado; Tincani, Angela; Madaio, Michael; Radice, Antonella; Franceschini, Franco; Trezzi, Barbara; Bianchi, Laura; Giallongo, Agata; Gatti, Rita; Tardanico, Regina; Scaloni, Andrea; D’Ambrosio, Chiara; Carnevali, Maria Luisa; Messa, Piergiorgio; Ravani, Pietro; Barbano, Giancarlo; Bianco, Beatrice; Bonanni, Alice; Scolari, Francesco; Martini, Alberto; Candiano, Giovanni; Allegri, Landino

    2014-01-01

    Renal targets of autoimmunity in human lupus nephritis (LN) are unknown. We sought to identify autoantibodies and glomerular target antigens in renal biopsy samples from patients with LN and determine whether the same autoantibodies can be detected in circulation. Glomeruli were microdissected from biopsy samples of 20 patients with LN and characterized by proteomic techniques. Serum samples from large cohorts of patients with systemic lupus erythematosus (SLE) with and without LN and other glomerulonephritides were tested. Glomerular IgGs recognized 11 podocyte antigens, with reactivity varying by LN pathology. Notably, IgG2 autoantibodies against α-enolase and annexin AI were detected in 11 and 10 of the biopsy samples, respectively, and predominated over other autoantibodies. Immunohistochemistry revealed colocalization of α-enolase or annexin AI with IgG2 in glomeruli. High levels of serum anti–α-enolase (>15 mg/L) IgG2 and/or anti-annexin AI (>2.7 mg/L) IgG2 were detected in most patients with LN but not patients with other glomerulonephritides, and they identified two cohorts: patients with high anti–α-enolase/low anti-annexin AI IgG2 and patients with low anti–α-enolase/high anti-annexin AI IgG2. Serum levels of both autoantibodies decreased significantly after 12 months of therapy for LN. Anti–α-enolase IgG2 recognized specific epitopes of α-enolase and did not cross-react with dsDNA. Furthermore, nephritogenic monoclonal IgG2 (clone H147) derived from lupus-prone MRL-lpr/lpr mice recognized human α-enolase, suggesting homology between animal models and human LN. These data show a multiantibody composition in LN, where IgG2 autoantibodies against α-enolase and annexin AI predominate in the glomerulus and can be detected in serum. PMID:24790181

  14. A new cryptic cationic antimicrobial peptide from human apolipoprotein E with antibacterial activity and immunomodulatory effects on human cells.

    PubMed

    Pane, Katia; Sgambati, Valeria; Zanfardino, Anna; Smaldone, Giovanni; Cafaro, Valeria; Angrisano, Tiziana; Pedone, Emilia; Di Gaetano, Sonia; Capasso, Domenica; Haney, Evan F; Izzo, Viviana; Varcamonti, Mario; Notomista, Eugenio; Hancock, Robert E W; Di Donato, Alberto; Pizzo, Elio

    2016-06-01

    Cationic antimicrobial peptides (AMPs) possess fast and broad-spectrum activity against both Gram-negative and Gram-positive bacteria, as well as fungi. It has become increasingly evident that many AMPs, including those that derive from fragments of host proteins, are multifunctional and able to mediate various immunomodulatory functions and angiogenesis. Among these, synthetic apolipoprotein-derived peptides are safe and well tolerated in humans and have emerged as promising candidates in the treatment of various inflammatory conditions. Here, we report the characterization of a new AMP corresponding to residues 133-150 of human apolipoprotein E. Our results show that this peptide, produced either by chemical synthesis or by recombinant techniques in Escherichia coli, possesses a broad-spectrum antibacterial activity. As shown for several other AMPs, ApoE (133-150) is structured in the presence of TFE and of membrane-mimicking agents, like SDS, or bacterial surface lipopolysaccharide (LPS), and an anionic polysaccharide, alginate, which mimics anionic capsular exo-polysaccharides of several pathogenic microorganisms. Noteworthy, ApoE (133-150) is not toxic toward several human cell lines and triggers a significant innate immune response, assessed either as decreased expression levels of proinflammatory cytokines in differentiated THP-1 monocytic cells or by the induction of chemokines released from PBMCs. This novel bioactive AMP also showed a significant anti-inflammatory effect on human keratinocytes, suggesting its potential use as a model for designing new immunomodulatory therapeutics. PMID:27028511

  15. Genetic studies of human apolipoproteins. XX. Genetic polymorphism of apolipoprotein J and its impact on quantitative lipid traits in normolipidemic subjects.

    PubMed Central

    Kamboh, M I; Harmony, J A; Sepehrnia, B; Nwankwo, M; Ferrell, R E

    1991-01-01

    Apolipoprotein J (apo J) is a newly identified member of a growing family of proteins associated with various lipoprotein particles. Apo J is a glycoprotein which exists in the plasma associated with high-density lipoprotein subfractions which also contain apo A-I and cholesteryl ester transfer protein (CETP). We have investigated the possible existence of genetic polymorphism at the apo J structural locus and have evaluated its role in lipid metabolism. By employing isoelectric focusing and immunoblotting techniques, we have screened plasma or serum samples from six population groups: U.S. whites, Amerindians, Eskimos, New Guineans, U.S. blacks, and Nigerian blacks. Apo J revealed a common two-allele polymorphism only in populations with African ancestry and was found to be monomorphic in all other population groups tested. The genetic basis of the two alleles designated--APO J*1 and APO J*2, at a single structural locus, apo J-- was confirmed in a large number of segregating families. In the U.S. blacks, the frequencies of the APO J*1 and APO J*2 alleles were .76 and .24, respectively, and in the Nigerian blacks these values were .72 and .28, respectively. In addition, a single example of a rare allele designated APO J*3 was also encountered in the U.S. black sample. In Nigerian blacks, the apo J polymorphism's impact on seven quantitative lipid traits--total cholesterol, LDL-cholesterol, HDL-cholesterol, HDL3-cholesterol, HDL2-cholesterol, VLDL-cholesterol, and triglycerides--was investigated. No significant impact of the apo J polymorphism was observed for any of these lipid traits. Images Figure 1 Figure 2 PMID:1746550

  16. Quantitative analysis of intact apolipoproteins in human HDL by top-down differential mass spectrometry

    PubMed Central

    Mazur, Matthew T.; Cardasis, Helene L.; Spellman, Daniel S.; Liaw, Andy; Yates, Nathan A.; Hendrickson, Ronald C.

    2010-01-01

    Top-down mass spectrometry holds tremendous potential for the characterization and quantification of intact proteins, including individual protein isoforms and specific posttranslationally modified forms. This technique does not require antibody reagents and thus offers a rapid path for assay development with increased specificity based on the amino acid sequence. Top-down MS is efficient whereby intact protein mass measurement, purification by mass separation, dissociation, and measurement of product ions with ppm mass accuracy occurs on the seconds to minutes time scale. Moreover, as the analysis is based on the accurate measurement of an intact protein, top-down mass spectrometry opens a research paradigm to perform quantitative analysis of “unknown” proteins that differ in accurate mass. As a proof of concept, we have applied differential mass spectrometry (dMS) to the top-down analysis of apolipoproteins isolated from human HDL3. The protein species at 9415.45 Da demonstrates an average fold change of 4.7 (p-value 0.017) and was identified as an O-glycosylated form of apolipoprotein C-III [NANA-(2 → 3)-Gal-β(1 → 3)-GalNAc, +656.2037 Da], a protein associated with coronary artery disease. This work demonstrates the utility of top-down dMS for quantitative analysis of intact protein mixtures and holds potential for facilitating a better understanding of HDL biology and complex biological systems at the protein level. PMID:20388904

  17. Carnitine palmitoyltransferase IA polymorphism P479L is common in Greenland Inuit and is associated with elevated plasma apolipoprotein A-I

    PubMed Central

    Rajakumar, Chandheeb; Ban, Matthew R.; Cao, Henian; Young, T. Kue; Bjerregaard, Peter; Hegele, Robert A.

    2009-01-01

    Carnitine palmitoyltransferase IA, encoded by CPT1A, is a key regulator of fatty acid metabolism. Previously, a loss-of-function mutation, namely, c.1436 C→T (p.P479L), was reported in CPT1A in the homozygous state in Canadian aboriginal male with presumed CPT1A deficiency. To determine the population frequency of this variant, we determined CPT1A p.P479L genotypes in 1111 Greenland Inuit. Associations between genotype and variation in plasma total cholesterol, triglycerides, LDL, HDL, apolipoprotein (apo) B, and apoA-I was also investigated. We found the L479 allele occurs at a high frequency in this sample (0.73), while it was completely absent in 285 nonaboriginal samples. This suggests that the original proband's symptoms were not likely due to the CPT1A p.P479L mutation because it is very common in Inuit and because symptoms suggesting CPT1A deficiency have not been reported in any carrier subsequently studied. However, CPT1A p.P479L was associated with elevated plasma HDL and apoA-I levels. The association with increased levels of HDL and apoA-I suggest that the polymorphism might protect against atherosclerosis. PMID:19181627

  18. Dual Actions of Apolipoprotein A-I on Glucose-Stimulated Insulin Secretion and Insulin-Independent Peripheral Tissue Glucose Uptake Lead to Increased Heart and Skeletal Muscle Glucose Disposal.

    PubMed

    Domingo-Espín, Joan; Lindahl, Maria; Nilsson-Wolanin, Oktawia; Cushman, Samuel W; Stenkula, Karin G; Lagerstedt, Jens O

    2016-07-01

    Apolipoprotein A-I (apoA-I) of HDL is central to the transport of cholesterol in circulation. ApoA-I also provides glucose control with described in vitro effects of apoA-I on β-cell insulin secretion and muscle glucose uptake. In addition, apoA-I injections in insulin-resistant diet-induced obese (DIO) mice lead to increased glucose-stimulated insulin secretion (GSIS) and peripheral tissue glucose uptake. However, the relative contribution of apoA-I as an enhancer of GSIS in vivo and as a direct stimulator of insulin-independent glucose uptake is not known. Here, DIO mice with instant and transient blockade of insulin secretion were used in glucose tolerance tests and in positron emission tomography analyses. Data demonstrate that apoA-I to an equal extent enhances GSIS and acts as peripheral tissue activator of insulin-independent glucose uptake and verify skeletal muscle as an apoA-I target tissue. Intriguingly, our analyses also identify the heart as an important target tissue for the apoA-I-stimulated glucose uptake, with potential implications in diabetic cardiomyopathy. Explorations of apoA-I as a novel antidiabetic drug should extend to treatments of diabetic cardiomyopathy and other cardiovascular diseases in patients with diabetes. PMID:27207515

  19. Patterns of association between genetic variability in apolipoprotein (apo) B, apo AI-CIII-AIV, and cholesterol ester transfer protein gene regions and quantitative variation in lipid and lipoprotein traits: influence of gender and exogenous hormones.

    PubMed Central

    Kessling, A; Ouellette, S; Bouffard, O; Chamberland, A; Bétard, C; Selinger, E; Xhignesse, M; Lussier-Cacan, S; Davignon, J

    1992-01-01

    Patterns of RFLP association were studied, to identify gene regions influencing quantitative variation in lipid and lipoprotein traits (coronary artery disease [CAD] risk factors or metabolically related traits). Subjects (118 female and 229 male; age 20-59 years) were selected for health. Multiple RFLPs were used to sample variability in regions around genes for apolipoprotein (apo) B (restriction enzymes HincII, PvuII, EcoRI, and XbaI), apo AI-CIII-AIV (BamHI, XmnI, TaqI, PstI, SstI, and PvuII) and cholesterol ester transfer protein (TaqI). Separate analyses were done by gender. The sample was truncated at mean +/- 4 SD, to remove extreme outliers. There was no significant gender difference in RFLP genotype frequency distribution. After trait-level adjustment to maximize removal of concomitant variability, analysis of variance was used to estimate the percentage trait phenotypic variance explained by measured variability in the gene regions studied. Fewer gene regions were involved in men, with less influence on quantitative trait variation than in women, in whom hormone use affected association patterns. Gender differences imply that pooling genders or adjusting data for gender effects removes genetic information and should be avoided. The association patterns show that variability around the candidate genes modulates trait levels: the genes are contributors to the genetics of CAD risk variables in a healthy sample. PMID:1346081

  20. Case report: A novel apolipoprotein A-I missense mutation apoA-I (Arg149Ser)Boston associated with decreased lecithin-cholesterol acyltransferase activation and cellular cholesterol efflux.

    PubMed

    Anthanont, Pimjai; Asztalos, Bela F; Polisecki, Eliana; Zachariah, Benoy; Schaefer, Ernst J

    2015-01-01

    We report a novel heterozygous apolipoprotein A-I (apoA-I) missense mutation (c.517C>A, p.Arg149Ser, designated as apoA-IBoston) in a 67-year-old woman and her 2 sons, who had mean serum high-density lipoprotein (HDL) cholesterol, apoA-I, and apoA-I in very large α-1 HDL that were 10%, 35%, and 16% of normal, respectively (all P < .05). The percentage of HDL cholesterol in the esterified form was also significantly (P < .05) reduced to 52% of control values. Cholesteryl ester tranfer protein (CETP) activity was normal. The mean global, adenosine triphosphate (ATP)-binding cassette transporter A1 and scavenger receptor B type I-mediated cellular cholesterol efflux capacity in apoB-depleted serum from affected family members were 41%, 37%, 47%, 54%, and 48% of control values, respectively (all P < .05). lecithin-cholesterol acyltransferase (LCAT) activity in plasma was 71% of controls, whereas in the cell-based assay, it was 73% of control values (P < .05). The data indicate that this novel apoA-I missense is associated with markedly decreased levels of HDL cholesterol and very large α-1 HDL, as well as decreased serum cellular cholesterol efflux and LCAT activity, but not with premature coronary heart disease, similar to other apoA-I mutations that have been associated with decreased LCAT activity. PMID:26073399

  1. Two regulatory elements of similar structure and placed in tandem account for the repressive activity of the first intron of the human apolipoprotein A-II gene.

    PubMed Central

    Bossu, J P; Chartier, F L; Fruchart, J C; Auwerx, J; Staels, B; Laine, B

    1996-01-01

    Recent reports indicate that apolipoprotein (apo) A-II, the second most abundant protein of high-density lipoproteins, plays a crucial role in counteracting the beneficial effect of apo A-I against atherogenesis. Transcription of the human apo A-II gene is controlled by an enhancer comprising 14 regulatory elements located upstream of its promoter whereas the first intron of this gene behaves as a silencer. Here we show that two sequence elements account for the repressive activity of this intron and correspond to negative regulatory elements termed NRE I and NRE II. The activity of intron I and the nuclear proteins binding to NRE I and II are encountered in hepatic cells but not in non-hepatic cells studied here. Both NREs form nucleoprotein complexes of very similar physicochemical characteristics and bind the same or closely related proteins. Site-directed mutagenesis, transient transfection and gel-shift analysis experiments indicate that both NREs exhibit similar structures, being composed of two sites required for maximal activity and optimal binding of transcription factors. Therefore two negative regulatory elements of similar structure and function, placed in tandem, account for the repressive activity of the first intron of the human apo A-II gene. These NREs do not exhibit structural similarity with known NREs of other genes. PMID:8809045

  2. Transgenic human C-reactive protein is not proatherogenic in apolipoprotein E-deficient mice

    PubMed Central

    Hirschfield, Gideon M.; Gallimore, J. Ruth; Kahan, Melvyn C.; Hutchinson, Winston L.; Sabin, Caroline A.; Benson, G. Martin; Dhillon, Amar P.; Tennent, Glenys A.; Pepys, Mark B.

    2005-01-01

    The association between circulating concentrations of C-reactive protein (CRP) and future atherothrombotic events has provoked speculation about a possible pathogenetic role of CRP. However, we show here that transgenic expression of human CRP had no effect on development, progression, or severity of spontaneous atherosclerosis, or on morbidity or mortality, in male apolipoprotein E (apoE)-deficient C57BL/6 mice up to 56 weeks, despite deposition of human CRP and mouse complement component 3 in the plaques. Although female apoE knockouts develop atherosclerosis more rapidly than males, the human CRP transgene is under sex hormone control and is expressed at human levels only in males. We therefore studied only male mice. The concentration of mouse serum amyloid P component, an extremely sensitive systemic marker of inflammation, remained normal throughout except for transient spikes in response to fighting in a few animals, indicating that atherogenesis in this model is not associated with an acute-phase response. However, among human CRP transgenic mice, the circulating CRP concentration was higher in apoE knockouts than in wild-type controls. The higher CRP values were associated with substantially lower estradiol concentrations in the apoE-deficient animals. Human CRP transgene expression is thus up-regulated in apoE-deficient mice, apparently reflecting altered estrogen levels, despite the absence of other systemic signs of inflammation. Extrapolation to human pathology from this xenogeneic combination of human CRP with apoE deficiency-mediated mouse atherosclerosis must be guarded. Nevertheless, the present results do not suggest that human CRP is either proatherogenic or atheroprotective in vivo. PMID:15919817

  3. Apolipoprotein A-I glycation by Glucose and Reactive Aldehydes Alters Phospholipid Affinity but Not Cholesterol Export from Lipid-Laden Macrophages

    PubMed Central

    Brown, Bronwyn E.; Nobecourt, Estelle; Zeng, Jingmin; Jenkins, Alicia J.; Rye, Kerry-Anne; Davies, Michael J.

    2013-01-01

    Increased protein glycation in people with diabetes may promote atherosclerosis. This study examined the effects of non-enzymatic glycation on the association of lipid-free apolipoproteinA-I (apoA-I) with phospholipid, and cholesterol efflux from lipid-loaded macrophages to lipid-free and lipid-associated apoA-I. Glycation of lipid-free apoA-I by methylglyoxal and glycolaldehyde resulted in Arg, Lys and Trp loss, advanced glycation end-product formation and protein cross-linking. The association of apoA-I glycated by glucose, methylglyoxal or glycolaldehyde with phospholipid multilamellar vesicles was impaired in a glycating agent dose-dependent manner, with exposure of apoA-I to both 30 mM glucose (42% decrease in kslow) and 3 mM glycolaldehyde (50% decrease in kfast, 60% decrease in kslow) resulting is significantly reduced affinity. Cholesterol efflux to control or glycated lipid-free apoA-I, or discoidal reconstituted HDL containing glycated apoA-I (drHDL), was examined using cholesterol-loaded murine (J774A.1) macrophages treated to increase expression of ATP binding cassette transporters A1 (ABCA1) or G1 (ABCG1). Cholesterol efflux from J774A.1 macrophages to glycated lipid-free apoA-I via ABCA1 or glycated drHDL via an ABCG1-dependent mechanism was unaltered, as was efflux to minimally modified apoA-I from people with Type 1 diabetes, or controls. Changes to protein structure and function were prevented by the reactive carbonyl scavenger aminoguanidine. Overall these studies demonstrate that glycation of lipid-free apoA-I, particularly late glycation, modifies its structure, its capacity to bind phospholipids and but not ABCA1- or ABCG1-dependent cholesterol efflux from macrophages. PMID:23741493

  4. Expression and Purification of Recombinant Human Apolipoprotein A-II in Pichia pastoris

    PubMed Central

    Su, Manman; Qi, Yitian; Wang, Mingxing; Chang, Weiqin; Peng, Shuang; Wang, Dingding

    2013-01-01

    Abstract Apolipoprotein A-II (ApoA-II) is the second most abundant protein constituent of high-density lipoprotein (HDL). The physiologic role of ApoA-II is poorly defined. ApoA-II may inhibit lecithin:cholesterol acyltransferase and cholesteryl-ester-transfer protein activities, but may increase the hepatic lipase activity. ApoA-II may also inhibit the hepatic cholesteryl uptake from HDL probably through the scavenger receptor class B type I depending pathway. Interpretation of data from transgenic and knockout mice of genes involved in lipoprotein metabolism has been often complicated as clinical implications because of species difference. So it is important to obtain human ApoA-II for further studies about its functions. In our studies, Pichia pastoris expression system was first used to express a high-level secreted recombinant human ApoA-II (rhApoA-II). We have cloned the cDNA encoding human ApoA-II and achieved its high-level secreting expression with a yield of 65 mg/L of yeast culture and the purification process was effective and easy to handle. The purified rhApoA-II can be used to further study its biological activities. PMID:24116940

  5. Production of human apolipoprotein(a) transgenic NIBS miniature pigs by somatic cell nuclear transfer.

    PubMed

    Shimatsu, Yoshiki; Horii, Wataru; Nunoya, Tetsuo; Iwata, Akira; Fan, Jianglin; Ozawa, Masayuki

    2016-01-01

    Most cases of ischemic heart disease and stroke occur as a result of atherosclerosis. The purpose of this study was to produce a new Nippon Institute for Biological Science (NIBS) miniature pig model by somatic cell nuclear transfer (SCNT) for studying atherosclerosis. The human apolipoprotein(a) (apo(a)) genes were transfected into kidney epithelial cells derived from a male and a female piglet. Male cells were used as donors initially, and 275 embryos were transferred to surrogates. Three offspring were delivered, and the production efficiency was 1.1% (3/275). Serial female cells were injected into 937 enucleated oocytes. Eight offspring were delivered (production efficiency: 0.9%) from surrogates. One male and 2 female transgenic miniature pigs matured well. Lipoprotein(a) was found in the male and one of the female transgenic animals. These results demonstrate successful production of human apo(a) transgenic NIBS miniature pigs by SCNT. Our goal is to establish a human apo(a) transgenic NIBS miniature pig colony for studying atherosclerosis. PMID:26411321

  6. Apolipoprotein A5: A newly identified gene impacting plasmatriglyceride levels in humans and mice

    SciTech Connect

    Pennacchio, Len A.; Rubin, Edward M.

    2002-09-15

    Apolipoprotein A5 (APOA5) is a newly described member of theapolipoprotein gene family whose initial discovery arose from comparativesequence analysis of the mammalian APOA1/C3/A4 gene cluster. Functionalstudies in mice indicated that alteration in the level of APOA5significantly impacted plasma triglyceride concentrations. Miceover-expressing human APOA5 displayed significantly reducedtriglycerides, while mice lacking apoA5 had a large increase in thislipid parameter. Studies in humans have also suggested an important rolefor APOA5 in determining plasma triglyceride concentrations. In theseexperiments, polymorphisms in the human gene were found to define severalcommon haplotypes that were associated with significant changes intriglyceride concentrations in multiple populations. Several separateclinical studies have provided consistent and strong support for theeffect with 24 percent of Caucasians, 35 percent of African-Americans and53 percent of Hispanics carrying APOA5 haplotypes associated withincreased plasma triglyceride levels. In summary, APOA5 represents anewly discovered gene involved in triglyceride metabolism in both humansand mice whose mechanism of action remains to be deciphered.

  7. Production of human apolipoprotein(a) transgenic NIBS miniature pigs by somatic cell nuclear transfer

    PubMed Central

    Shimatsu, Yoshiki; Horii, Wataru; Nunoya, Tetsuo; Iwata, Akira; Fan, Jianglin; Ozawa, Masayuki

    2015-01-01

    Most cases of ischemic heart disease and stroke occur as a result of atherosclerosis. The purpose of this study was to produce a new Nippon Institute for Biological Science (NIBS) miniature pig model by somatic cell nuclear transfer (SCNT) for studying atherosclerosis. The human apolipoprotein(a) (apo(a)) genes were transfected into kidney epithelial cells derived from a male and a female piglet. Male cells were used as donors initially, and 275 embryos were transferred to surrogates. Three offspring were delivered, and the production efficiency was 1.1% (3/275). Serial female cells were injected into 937 enucleated oocytes. Eight offspring were delivered (production efficiency: 0.9%) from surrogates. One male and 2 female transgenic miniature pigs matured well. Lipoprotein(a) was found in the male and one of the female transgenic animals. These results demonstrate successful production of human apo(a) transgenic NIBS miniature pigs by SCNT. Our goal is to establish a human apo(a) transgenic NIBS miniature pig colony for studying atherosclerosis. PMID:26411321

  8. Inhibition of apolipoprotein B and triglyceride secretion in human hepatoma cells (HepG2).

    PubMed

    Haghpassand, M; Wilder, D; Moberly, J B

    1996-07-01

    Apolipoprotein B (apoB), the major protein component of triglyceride-rich lipoproteins, is assembled into a lipoprotein particle via a complex, multistep process. Recent studies indicate that triglyceride-rich lipoprotein assembly requires the activity of the heterodimeric protein, microsomal triglyceride transfer protein (MTP). We identified a novel inhibitor of apolipoprotein B secretion using the human hepatoma cell line, HepG2. CP-10447, a derivative of the hypnotic drug methaqualone (Quaalude), inhibited apoB secretion from HepG2 cells with an IC50 of approximately 5 microM. CP-10447 also inhibited apoB secretion from Caco-2 cells, a model of intestinal lipoprotein production. In experiments using [3H]glycerol as a precursor for triglyceride synthesis, CP-10447 (20 microM) inhibited radiolabeled triglyceride secretion by approximately 83% (P < 0.0001) in HepG2 cells and 76% (P < 0.05) in Caco-2 cells with no effect on radiolabel incorporation into cellular triglyceride, indicating that CP-10447 inhibited triglyceride secretion without affecting triglyceride synthesis. RNA solution hybridization assay indicated that CP-10447 did not affect apoB or apoA-I mRNA levels. Pulse-chase experiments in HepG2 cells confirmed that CP-10447 inhibited the secretion of apoB (not its synthesis) without affecting secretion of total proteins or albumin and suggested that CP-10447 stimulates the early intracellular degradation of apoB in the endoplasmic reticulum (ER). Further studies demonstrated that CP-10447 is a potent inhibitor of human liver microsomal triglyceride transfer activity (IC50 approximately 1.7 microM) in an in vitro assay containing artificial liposomes and partially purified human MTP. These data suggest that CP-10447 may inhibit apoB and triglyceride secretion by inhibiting MTP activity and stimulating the early ER degradation of apoB. CP-10447 should provide a useful tool for further study of the mechanisms of apoB secretion and triglyceride

  9. Production of Cloned Miniature Pigs Expressing High Levels of Human Apolipoprotein(a) in Plasma.

    PubMed

    Ozawa, Masayuki; Himaki, Takehiro; Ookutsu, Shoji; Mizobe, Yamato; Ogawa, Junki; Miyoshi, Kazuchika; Yabuki, Akira; Fan, Jianglin; Yoshida, Mitsutoshi

    2015-01-01

    High lipoprotein(a) [Lp(a)] levels are a major risk factor for the development of atherosclerosis. However, because apolipoprotein(a) [apo(a)], the unique component of Lp(a), is found only in primates and humans, the study of human Lp(a) has been hampered due to the lack of appropriate animal models. Using somatic cell nuclear transfer (SCNT) techniques, we produced transgenic miniature pigs expressing human apo(a) in the plasma. First, we placed the hemagglutinin (HA)-tagged cDNA of human apo(a) under the control of the β-actin promoter and cytomegalovirus enhancer, and then introduced this construct into kidney epithelial cells. Immunostaining of cells with anti-HA antibody allowed identification of cells stably expressing apo(a); one of the positive clones was used to provide donor cells for SCNT, yielding blastocysts that expressed apo(a). Immunohistochemical analysis of tissue sections and RT-PCR analysis of total RNA from organs of cloned piglet revealed that apo(a) is expressed in various tissues/organs including heart, liver, kidney, and intestine. More importantly, a transgenic line exhibited a high level (>400 mg/dL) of Lp(a) in plasma, and the transgenic apo(a) gene was transmitted to the offspring. Thus, we generated a human apo(a)-transgenic miniature pig that can be used as a model system to study advanced atherosclerosis related to human disease. The anatomical and physiological similarities between the swine and human cardiovascular systems will make this pig model a valuable source of information on the role of apo(a) in the formation of atherosclerosis, as well as the mechanisms underlying vascular health and disease. PMID:26147378

  10. Production of Cloned Miniature Pigs Expressing High Levels of Human Apolipoprotein(a) in Plasma

    PubMed Central

    Ozawa, Masayuki; Himaki, Takehiro; Ookutsu, Shoji; Mizobe, Yamato; Ogawa, Junki; Miyoshi, Kazuchika; Yabuki, Akira; Fan, Jianglin; Yoshida, Mitsutoshi

    2015-01-01

    High lipoprotein(a) [Lp(a)] levels are a major risk factor for the development of atherosclerosis. However, because apolipoprotein(a) [apo(a)], the unique component of Lp(a), is found only in primates and humans, the study of human Lp(a) has been hampered due to the lack of appropriate animal models. Using somatic cell nuclear transfer (SCNT) techniques, we produced transgenic miniature pigs expressing human apo(a) in the plasma. First, we placed the hemagglutinin (HA)-tagged cDNA of human apo(a) under the control of the β-actin promoter and cytomegalovirus enhancer, and then introduced this construct into kidney epithelial cells. Immunostaining of cells with anti-HA antibody allowed identification of cells stably expressing apo(a); one of the positive clones was used to provide donor cells for SCNT, yielding blastocysts that expressed apo(a). Immunohistochemical analysis of tissue sections and RT-PCR analysis of total RNA from organs of cloned piglet revealed that apo(a) is expressed in various tissues/organs including heart, liver, kidney, and intestine. More importantly, a transgenic line exhibited a high level (>400 mg/dL) of Lp(a) in plasma, and the transgenic apo(a) gene was transmitted to the offspring. Thus, we generated a human apo(a)–transgenic miniature pig that can be used as a model system to study advanced atherosclerosis related to human disease. The anatomical and physiological similarities between the swine and human cardiovascular systems will make this pig model a valuable source of information on the role of apo(a) in the formation of atherosclerosis, as well as the mechanisms underlying vascular health and disease. PMID:26147378

  11. Comparative surface antimicrobial properties of synthetic biocides and novel human apolipoprotein E derived antimicrobial peptides.

    PubMed

    Forbes, Sarah; McBain, Andrew J; Felton-Smith, Susan; Jowitt, Thomas A; Birchenough, Holly L; Dobson, Curtis B

    2013-07-01

    Medical device infection remains a major clinical concern. Biocidal compounds have been incorporated into medical device materials ideally to inhibit bacterial colonisation whilst exhibiting relatively low cytotoxicity. We compared the antibacterial activity, anti-biofilm efficacy and cytotoxicity of a novel peptide derivative of human apolipoprotein E (apoEdpL-W) to that of commonly used biocides, before and after coating onto a range of standard polymers. Since the antimicrobial function of most biocides frequently involves associations with cellular membranes, we have also studied the detailed interactions of the test antimicrobials with phospholipid bilayers, using the quartz crystal microbalance device combined with dual-polarisation interferometry. ApoEdpL-W displayed broad-spectrum antibacterial activity and marked efficacy against nascent Staphylococcus aureus biofilms. Compounds showed better antimicrobial activity when combined with hydrogel materials than with non-porous materials. The membrane interactions of apoEdpL-W were most similar to that of PHMB, with both agents appearing to readily bind and insert into lipid bilayers, possibly forming pores. However apoEdpL-W showed lower cytotoxicity than PHMB, its efficacy was less affected by the presence of serum, and it demonstrated the highest level of biocompatibility of all the biocides, as indicated by our measurement of its antimicrobial biocompatibility index. This work shows the potential of apoEdpL-W as an effective antiseptic coating agent. PMID:23623325

  12. Expression of the human apolipoprotein E gene suppresses steroidogenesis in mouse Y1 adrenal cells

    SciTech Connect

    Reyland, M.E.; Forgez, P.; Prack, M.M.; Williams, D.L. ); Gwynne, J.T. )

    1991-03-15

    The lipid transport protein, apolipoprotein E (apoE), is expressed in many peripheral tissues in vivo including the adrenal gland and testes. To investigate the role of apoE in adrenal cholesterol homeostasis, the authors have expressed a human apoE genomic clone in the Y1 mouse adrenocortical cell line. Y1 cells do not express endogenous apoE mRNA or protein. Expression of apoE in Y1 cells resulted in a dramatic decrease in basal steroidogenesis; secretion of fluorogenic steroid was reduced 7- to {gt}100-fold relative to Y1 parent cells. Addition of 5-cholesten-3{beta},25-idol failed to overcome the suppression of steroidogenesis in these cells. Cholesterol esterification under basal conditions, as measured by the production of cholesteryl ({sup 14}C)oleate, was similar in the Y1 parent and the apoE-transfected cell lines. Upon incubation with adrenocorticotropin or dibutyryl cAMP, production of cholesteryl ({sup 14}C)oleate decreased 5-fold in the Y1 parent cells but was unchanged in the apoE-transfected cell lines. These results suggest that apoE may be an important modulator of cholesterol utilization and steroidogenesis in adrenal cells.

  13. The insertion of human apolipoprotein H into phospholipid membranes: a monolayer study.

    PubMed Central

    Wang, S X; Cai, G P; Sui, S F

    1998-01-01

    Apolipoprotein H (ApoH) is a plasma glycoprotein isolated from human serum. The interactions of ApoH with lipid membrane were reported to be essential for its physiological and pathogenic roles. In this paper we studied the ability of ApoH to insert into phospholipid membranes using the monolayer approach. The results show that ApoH is surface active and can insert into the lipid monolayers. The insertion ability of ApoH is stronger when a higher content of negatively charged lipids is present in the membrane. The acidic-pH and low-ionic-strength conditions will also enhance ApoH insertion, but these factors may not have much influence on the final insertion ability of ApoH, suggesting that, in the mechanism of ApoH insertion, not only electrostatic forces, but also hydrophobic interactions, are evidently involved. Modification by heat inactivation and reduction/alkylation does not change the critical insertion pressure (pic) of ApoH, suggesting a stable domain, maybe a linear sequence motif, but not the native three-dimensional structure of ApoH, is responsible for its insertion. The extent to which insertion of ApoH into phospholipid membranes may facilitate the 'immune cleaning' of plasma liposomes is discussed. PMID:9761718

  14. Distinctive structure and interfacial activity of the human apolipoprotein A-IV 347S isoprotein

    PubMed Central

    Weinberg, Richard B.; Cook, Victoria R.

    2010-01-01

    The T347S polymorphism in the human apolipoprotein (apo) A-IV gene is present at high frequencies among all the world's populations. Carriers of a 347S allele exhibit faster clearance of triglyceride-rich lipoproteins, greater adiposity, and increased risk for developing atherosclerosis, which suggests that this conservative amino acid substitution alters the structure of apo A-IV. Herein we have used spectroscopic and surface chemistry techniques to examine the structure, stability, and interfacial properties of the apo A-IV 347S isoprotein. Circular dichroism spectroscopy revealed that the 347S isoprotein has similar α-helical structure but lower thermodynamic stability than the 347T isoprotein. Fluorescence spectroscopy found that the 347S isoprotein exhibits an enhanced tyrosine emission and reduced tyrosine→tryptophan energy transfer, and second derivative UV absorption spectra noted increased tyrosine exposure, suggesting that the 347S isoprotein adopts a looser tertiary conformation. Surface chemistry studies found that although the 347S isoprotein bound rapidly to the lipid interface, it has a lower interfacial exclusion pressure and lower elastic modulus than the 347T isoprotein. Together, these observations establish that the T347S substitution alters the conformation of apo A-IV and lowers its interfacial activity—changes that could account for the effect of this polymorphism on postprandial lipid metabolism. PMID:20554794

  15. Modulation of Apolipoprotein D levels in human pregnancy and association with gestational weight gain

    PubMed Central

    2009-01-01

    Background Apolipoprotein D (ApoD) is a lipocalin involved in several processes including lipid transport, but its modulation during human pregnancy was never examined. Methods We investigated the changes in the levels of ApoD in the plasma of pregnant women at the two first trimesters of gestation and at delivery as well as in the placenta and in venous cord blood. These changes were studied in 151 women classified into 9 groups in relation to their prepregnancy body mass index (BMI) and gestational weight gain (GWG). Results Plasma ApoD levels decrease significantly during normal uncomplicated pregnancy. ApoD is further decreased in women with excessive GWG and their newborns. In these women, the ApoD concentration was tightly associated with the lipid parameters. However, the similar ApoD levels in low cholesterol (LC) and high cholesterol (HC) women suggest that the plasma ApoD variation is not cholesterol dependant. A tight regulation of both placental ApoD transcription and protein content is most probably at the basis of the low circulating ApoD concentrations in women with excessive GWG. After delivery, the plasma ApoD concentrations depended on whether the mother was breast-feeding or not, lactation favoring a faster return to baseline values. Conclusion It is speculated that the decrease in plasma ApoD concentration during pregnancy is an adaptive response aimed at maintaining fetal lipid homeostasis. The exact mechanism of this adaptation is not known. PMID:19723339

  16. Bringing AI to Life

    NASA Astrophysics Data System (ADS)

    Copple, Kevin L.

    Participation in the Loebner Prize Contest is a useful exercise in the development of intelligent computer systems (AI). This contest helps put a focus on performance and human interaction, countering idealistic and academic bias toward the elusive "true AI". Collection of a steadily expanding set of interacting features is being explored to find how far this approach can move toward better AI.

  17. Phospholipase A2 Mediates Apolipoprotein-Independent Uptake of Chylomicron Remnant-Like Particles by Human Macrophages

    PubMed Central

    Napolitano, Mariarosaria; Kruth, Howard S.; Bravo, Elena

    2012-01-01

    Apolipoprotein E-receptor-mediated pathways are the main routes by which macrophages take up chylomicron remnants, but uptake may also be mediated by receptor-independent routes. To investigate these mechanisms, triacylglycerol (TG) accumulation induced by apolipoprotein-free chylomicron remnant-like particles (CRLPw/o) in human monocyte-derived macrophages was evaluated. Macrophage TG content increased about 5-fold after incubation with CRLPw/o, and this effect was not reduced by the inhibition of phagocytosis, macropinocytosis, apolipoprotein E function, or proteoglycan bridging. The role of lipases, including lipoprotein lipase, cholesteryl ester hydrolase, and secretory (sPLA2) and cytosolic phospholipase A2, was studied using [3H]TG-labelled CRLPw/o. Total cell radioactivity after incubation with [3H]TG CRLPw/o was reduced by 15–30% by inhibitors of lipoprotein lipase and cholesteryl ester hydrolase and by about 45% by inhibitors of sPLA2 and cytosolic PLA2 . These results suggest that macrophage lipolytic enzymes mediate the internalization of postprandial TG-rich lipoproteins and that sPLA2 and cytosolic PLA2, play a more important role than extracellular lipoprotein lipase-mediated TG hydrolysis. PMID:21876814

  18. Complex effects of inhibiting hepatic apolipoprotein B100 synthesis in humans

    PubMed Central

    Reyes-Soffer, Gissette; Moon, Byoung; Hernandez-Ono, Antonio; Dionizovik-Dimanovski, Marija; Jimenez, Jhonsua; Obunike, Joseph; Thomas, Tiffany; Ngai, Colleen; Fontanez, Nelson; Donovan, Daniel S.; Karmally, Wahida; Holleran, Stephen; Ramakrishnan, Rajasekhar; Mittleman, Robert S.; Ginsberg, Henry N.

    2016-01-01

    Mipomersen is a 20mer antisense oligonucleotide (ASO) that inhibits apolipoprotein B (apoB) synthesis; its low-density lipoprotein (LDL)–lowering effects should therefore result from reduced secretion of very-low-density lipoprotein (VLDL). We enrolled 17 healthy volunteers who received placebo injections weekly for 3 weeks followed by mipomersen weekly for 7 to 9 weeks. Stable isotopes were used after each treatment to determine fractional catabolic rates and production rates of apoB in VLDL, IDL (intermediate-density lipoprotein), and LDL, and of triglycerides in VLDL. Mipomersen significantly reduced apoB in VLDL, IDL, and LDL, which was associated with increases in fractional catabolic rates of VLDL and LDL apoB and reductions in production rates of IDL and LDL apoB. Unexpectedly, the production rates of VLDL apoB and VLDL triglycerides were unaffected. Small interfering RNA–mediated knockdown of apoB expression in human liver cells demonstrated preservation of apoB secretion across a range of apoB synthesis. Titrated ASO knockdown of apoB mRNA in chow-fed mice preserved both apoB and triglyceride secretion. In contrast, titrated ASO knockdown of apoB mRNA in high-fat–fed mice resulted in stepwise reductions in both apoB and triglyceride secretion. Mipomersen lowered all apoB lipoproteins without reducing the production rate of either VLDL apoB or triglyceride. Our human data are consistent with longstanding models of posttranscriptional and posttranslational regulation of apoB secretion and are supported by in vitro and in vivo experiments. Targeting apoB synthesis may lower levels of apoB lipoproteins without necessarily reducing VLDL secretion, thereby lowering the risk of steatosis associated with this therapeutic strategy. PMID:26819195

  19. Human Apolipoprotein E Isoforms differentially affect Bone Mass and Turnover in vivo

    PubMed Central

    Dieckmann, Marco; Beil, F. Timo; Mueller, Brigitte; Bartelt, Alexander; Marshall, Robert P.; Koehne, Till; Amling, Michael; Ruether, Wolfgang; Cooper, Jackie A.; Humphries, Steve E.; Herz, Joachim; Niemeier, Andreas

    2012-01-01

    The primary role of apolipoprotein E (apoE) is to mediate the cellular uptake of lipoproteins. However, a new role for apoE as a regulator of bone metabolism in mice has recently been established. In contrast to mice, the human APOE gene is characterized by three common isoforms APOE ε2, ε3 and ε4 that result in different metabolic properties of the apoE isoforms, but it remains controversial whether the APOE polymorphism influences bone traits in humans. To clarify this, we investigated bone phenotypes of apoE knock-in mice, which express one human isoform each (apoE2 k.i., apoE3 k.i., apoE4 k.i.) in place of the mouse apoE. Analysis of 12 week-old female knock-in mice revealed increased levels of biochemical bone formation and resorption markers in apoE2 k.i. animals as compared to apoE3 k.i. and apoE4 k.i., with a reduced OPG/RANKL ratio in apoE2 k.i., indicating increased turnover with prevailing resorption in apoE2 k.i.. Accordingly, histomorphometric and μCT analyses demonstrated significantly lower trabecular bone mass in apoE2 than in apoE3 and apoE4 k.i. animals, which was reflected by a significant reduction of lumbar vertebrae maximum force resistance. Unlike trabecular bone, femoral cortical thickness, and stability was not differentially affected by the apoE isoforms. To extend these observations to the human situation, plasma from middle-aged healthy men homozygous for ε2/ε2, ε3/ε3, and ε4/ε4 (n=21, n=80, n=55 respectively) was analyzed with regard to bone turnover markers. In analogy to apoE2 k.i. mice, a lower OPG/RANKL ratio was observed in the serum of ε2/ε2 carriers as compared to ε3/ε3 and ε4/ε4 individuals (p=0.02 for ε2/ε2 vs ε4/ε4). In conclusion, the current data strongly underline the general importance of apoE as a regulator of bone metabolism and identifies the APOE ε2 allele as a potential genetic risk factor for low trabecular bone mass and vertebral fractures in humans. PMID:22991192

  20. Fluorescence study of domain structure and lipid interaction of human apolipoproteins E3 and E4.

    PubMed

    Mizuguchi, Chiharu; Hata, Mami; Dhanasekaran, Padmaja; Nickel, Margaret; Okuhira, Keiichiro; Phillips, Michael C; Lund-Katz, Sissel; Saito, Hiroyuki

    2014-12-01

    Human apolipoprotein E (apoE) isoforms exhibit different conformational stabilities and lipid-binding properties that give rise to altered cholesterol metabolism among the isoforms. Using Trp-substituted mutations and site- directed fluorescence labeling, we made a comprehensive comparison of the conformational organization of the N- and C-terminal domains and lipid interactions between the apoE3 and apoE4 isoforms. Trp fluorescence measurements for selectively Trp-substituted variants of apoE isoforms demonstrated that apoE4 adopts less stable conformations in both the N- and C-terminal domains compared to apoE3. Consistent with this, the conformational reorganization of the N-terminal helix bundle occurs at lower guanidine hydrochloride concentration in apoE4 than in apoE3 as monitored by fluorescence resonance energy transfer (FRET) from Trp residues to acrylodan attached at the N-terminal helix. Upon binding of apoE3 and apoE4 variants to egg phosphatidylcholine small unilamellar vesicles, similar changes in Trp fluorescence or FRET efficiency were observed for the isoforms, indi- cating that the opening of the N-terminal helix bundle occurs similarly in apoE3 and apoE4. Introduction of mutations into the C-terminal domain of the apoE isoforms to prevent self-association and maintain the monomeric state resulted in great increase in the rate of binding of the C-terminal helices to a lipid surface. Overall, our results demonstrate that the different conformational organizations of the N- and C-terminal domains have a minor effect on the steady-state lipid-binding behavior of apoE3 and apoE4: rather, self-association property is a critical determinant in the kinetics of lipid binding through the C-terminal helices of apoE isoforms. PMID:25281910

  1. Fluorescence Study of Domain Structure and Lipid Interaction of Human Apolipoproteins E3 and E4

    PubMed Central

    Mizuguchi, Chiharu; Hata, Mami; Dhanasekaran, Padmaja; Nickel, Margaret; Okuhira, Keiichiro; Phillips, Michael C.; Lund-Katz, Sissel; Saito, Hiroyuki

    2014-01-01

    Human apolipoprotein E (apoE) isoforms exhibit different conformational stabilities and lipid-binding properties that give rise to altered cholesterol metabolism among the isoforms. Using Trp-substituted mutations and site-directed fluorescence labeling, we made a comprehensive comparison of the conformational organization of the N- and C-terminal domains and lipid interactions between the apoE3 and apoE4 isoforms. Trp fluorescence measurements for selectively Trp-substituted variants of apoE isoforms demonstrated that apoE4 adopts less stable conformations in both the N- and C-terminal domains compared to apoE3. Consistent with this, the conformational reorganization of the N-terminal helix bundle occurs at lower guanidine hydrochloride concentration in apoE4 than in apoE3 as monitored by fluorescence resonance energy transfer (FRET) from Trp residues to acrylodan attached at the N-terminal helix. Upon binding of apoE3 and apoE4 variants to egg phosphatidylcholine small unilamellar vesicles, similar changes in Trp fluorescence or FRET efficiency were observed for the isoforms, indicating that opening of the N-terminal helix bundle occurs similarly in apoE3 and apoE4. Introduction of mutations into the C-terminal domain of the apoE isoforms to prevent self-association and maintain the monomeric state resulted in great increase in the rate of binding of the C-terminal helices to a lipid surface. Overall, our results demonstrate that the different conformational organizations of the N- and C-terminal domains have a minor effect on the steady-state lipid-binding behavior of apoE3 and apoE4: rather, self-association property is a critical determinant in the kinetics of lipid binding through the C-terminal helices of apoE isoforms. PMID:25281910

  2. Determinants of Plasma Apolipoprotein A-V and APOA5 Gene Transcripts in Humans

    PubMed Central

    Hahne, P.; Krempler, F.; Schaap, F.G.; Soyal, S.M.; Höffinger, H.; Miller, K.; Oberkofler, H.; Strobl, W.; Patsch, W.

    2012-01-01

    Objective Apolipoprotein A-V (apoAV) contributes to the regulation of triglyceride metabolism, which plays a role in the pathogenesis of atherosclerotic diseases. We therefore ascertained determinants of hepatic APOA5 transcript and apoAV plasma levels in humans. Design We determined influences of anthropometric variables, biochemical factors related to lipid and glucose metabolism, hepatic mRNA levels transcribed from the APOA1/C3/A4/A5 cluster and transcription factor genes implicated in the regulation of APOA5 as well as common SNPs at the APOA5 locus on APOA5 expression in 89 obese patients and 22 non-obese controls. Results Mean, age and sex adjusted, hepatic APOA5 mRNA or apoAV plasma levels did not differ by obesity status, HOMA-IR or inflammatory markers. In multivariate regression models, the c56C>G SNP, plasma apoCIII, plasma non-esterified fatty acids, hepatic APOA5 transcripts, sex and a weak association with obesity status explained 61% of the variance in apoAV plasma levels. Hepatic transcript levels of CPT1A1 and PPARA, plasma non-esterified fatty acids and the c56C>G SNP explained 48% of the variance in hepatic APOA5 transcript levels. Conclusion ApoAV plasma levels are independently associated with plasma free fatty acid and hepatic APOA5 mRNA levels. Associations of APOA5 transcripts with PPARA and CPT1A1 transcripts suggest that APOA5 expression is intimately linked to hepatic lipid metabolism. PMID:18537870

  3. Determination of the radiation dose from administered apolipoprotein tracers in humans.

    PubMed

    Venkatakrishnan, V; Fisher, W R; Zech, L A

    1997-10-01

    Radioactive tracers are routinely used in investigation of the metabolism of apolipoprotein kinetics. Here, metabolic studies of apolipoprotein tracers labeled with radioiodine were analyzed to determine the absorbed radiation dose received by the subject. This analysis used compartmental modeling techniques to evaluate the radiation dose to various organs and the total body resulting from radioiodinated tracer injection. In this approach, we combined the published kinetic models of iodine and those of specific apolipoproteins. From the solution of the integrated compartmental models, residence times of the radiation in various source organs, in particular the thyroid, whole body, bladder, and red bone marrow, have been determined for the apolipoproteins apoA-I, apoA-II, very-low-density lipoprotein (VLDL)-apoB, and low-density lipoprotein (LDL)-apoB, each labeled with iodine 123, 133, 124, 131, 126, and 125. These tabulated values were used to calculate radiation doses to the different target organs. The thyroid is the organ that receives the largest dose of delivered radiation, and the importance of the duration of administration of iodine salts in blocking radiation to the thyroid is demonstrated. Optimal block times of 28 days for 131I and 42 days for 125I-labeled apolipoprotein tracers are proposed. When such a protocol is followed, the radiation dose to the thyroid and other organs is small by comparison to radiation doses allowed for workers whose occupation exposes them to radiation. The importance of frequent voiding to reduce the radiation dose to the bladder has also been demonstrated. PMID:9322813

  4. Role of Conserved Proline Residues in Human Apolipoprotein A-IV Structure and Function*

    PubMed Central

    Deng, Xiaodi; Walker, Ryan G.; Morris, Jamie; Davidson, W. Sean; Thompson, Thomas B.

    2015-01-01

    Apolipoprotein (apo)A-IV is a lipid emulsifying protein linked to a range of protective roles in obesity, diabetes, and cardiovascular disease. It exists in several states in plasma including lipid-bound in HDL and chylomicrons and as monomeric and dimeric lipid-free/poor forms. Our recent x-ray crystal structure of the central domain of apoA-IV shows that it adopts an elongated helical structure that dimerizes via two long reciprocating helices. A striking feature is the alignment of conserved proline residues across the dimer interface. We speculated that this plays important roles in the structure of the lipid-free protein and its ability to bind lipid. Here we show that the systematic conversion of these prolines to alanine increased the thermodynamic stability of apoA-IV and its propensity to oligomerize. Despite the structural stabilization, we noted an increase in the ability to bind and reorganize lipids and to promote cholesterol efflux from cells. The novel properties of these mutants allowed us to isolate the first trimeric form of an exchangeable apolipoprotein and characterize it by small-angle x-ray scattering and chemical cross-linking. The results suggest that the reciprocating helix interaction is a common feature of all apoA-IV oligomers. We propose a model of how self-association of apoA-IV can result in spherical lipoprotein particles, a model that may have broader applications to other exchangeable apolipoprotein family members. PMID:25733664

  5. Antiangiogenic Therapy with Human Apolipoprotein(a) Kringle V and Paclitaxel in a Human Ovarian Cancer Mouse Model12

    PubMed Central

    Yu, Hyun-Kyung; Lee, Ho-Jeong; Yun, Seok-Joong; Lee, Sun-Joo; Langley, Robert R.; Yoon, Yeup; Yi, Lee S.H.; Bae, Duk-Soo; Kim, Jang-Seong; Kim, Sun Jin

    2014-01-01

    INTRODUCTION: The present study compared the effect of combination therapy using human apolipoprotein(a) kringle V (rhLK8) to conventional chemotherapy with paclitaxel for human ovarian carcinoma producing high or low levels of vascular endothelial growth factor (VEGF). MATERIALS AND METHODS: Human ovarian carcinoma cells producing high (SKOV3ip1) or low (HeyA8) levels of VEGF were implanted into the peritoneal cavity of female nude mice. Seven days later, mice were randomized into four groups: control (vehicle), paclitaxel [5 mg/kg, weekly intraperitoneal (i.p.) injection], rhLK8 (50 mg/kg, daily i.p. injection), or the combination of paclitaxel and rhLK8. Mice were treated for 4 weeks and examined by necropsy. RESULTS: In mice implanted with SKOV3ip1 cells, rhLK8 treatment had no significant effect on tumor incidence or the volume of ascites but induced a significant decrease in tumor weight compared with control mice. Paclitaxel significantly reduced tumor weight and ascites volume, and combination treatment with paclitaxel and rhLK8 had an additive therapeutic effect. Similarly, in HeyA8 mice, the effect of combination treatment on tumor weight and tumor incidence was statistically significantly greater than that of paclitaxel or rhLK8 alone. Immunohistochemical analysis showed a significant decrease in microvessel density and a marked increase of apoptosis in tumor and tumor-associated endothelial cells in response to combination treatment with paclitaxel and rhLK8. CONCLUSION: Collectively, these results suggest that antiangiogenic therapy with rhLK8 in combination with taxane-based conventional chemotherapy could be effective for the treatment of ovarian carcinomas, regardless of VEGF status. PMID:25180060

  6. AI techniques for optimizing multi-objective reservoir operation upon human and riverine ecosystem demands

    NASA Astrophysics Data System (ADS)

    Tsai, Wen-Ping; Chang, Fi-John; Chang, Li-Chiu; Herricks, Edwin E.

    2015-11-01

    Flow regime is the key driver of the riverine ecology. This study proposes a novel hybrid methodology based on artificial intelligence (AI) techniques for quantifying riverine ecosystems requirements and delivering suitable flow regimes that sustain river and floodplain ecology through optimizing reservoir operation. This approach addresses issues to better fit riverine ecosystem requirements with existing human demands. We first explored and characterized the relationship between flow regimes and fish communities through a hybrid artificial neural network (ANN). Then the non-dominated sorting genetic algorithm II (NSGA-II) was established for river flow management over the Shihmen Reservoir in northern Taiwan. The ecosystem requirement took the form of maximizing fish diversity, which could be estimated by the hybrid ANN. The human requirement was to provide a higher satisfaction degree of water supply. The results demonstrated that the proposed methodology could offer a number of diversified alternative strategies for reservoir operation and improve reservoir operational strategies producing downstream flows that could meet both human and ecosystem needs. Applications that make this methodology attractive to water resources managers benefit from the wide spread of Pareto-front (optimal) solutions allowing decision makers to easily determine the best compromise through the trade-off between reservoir operational strategies for human and ecosystem needs.

  7. Liver proteomic response to hypertriglyceridemia in human-apolipoprotein C-III transgenic mice at cellular and mitochondrial compartment levels

    PubMed Central

    2014-01-01

    Background Hypertriglyceridemia (HTG) is defined as a triglyceride (TG) plasma level exceeding 150 mg/dl and is tightly associated with atherosclerosis, metabolic syndrome, obesity, diabetes and acute pancreatitis. The present study was undertaken to investigate the mitochondrial, sub-mitochondrial and cellular proteomic impact of hypertriglyceridemia in the hepatocytes of hypertriglyceridemic transgenic mice (overexpressing the human apolipoproteinC-III). Methods Quantitative proteomics (2D-DIGE) analysis was carried out on both “low-expressor” (LE) and “high-expressor” (HE) mice, respectively exhibiting moderate and severe HTG, to characterize the effect of the TG plasma level on the proteomic response. Results The mitoproteome analysis has revealed a large-scale phenomenon in transgenic mice, i.e. a general down-regulation of matricial proteins and up-regulation of inner membrane proteins. These data also demonstrate that the magnitude of proteomic changes strongly depends on the TG plasma level. Our different analyses indicate that, in HE mice, the capacity of several metabolic pathways is altered to promote the availability of acetyl-CoA, glycerol-3-phosphate, ATP and NADPH for TG de novo biosynthesis. The up-regulation of several cytosolic ROS detoxifying enzymes has also been observed, suggesting that the cytoplasm of HTG mice is subjected to oxidative stress. Moreover, our results suggest that iron over-accumulation takes place in the cytosol of HE mice hepatocytes and may contribute to enhance oxidative stress and to promote cellular proliferation. Conclusions These results indicate that the metabolic response to HTG in human apolipoprotein C-III overexpressing mice may support a high TG production rate and that the cytosol of hepatocytes is subjected to an important oxidative stress, probably as a result of FFA over-accumulation, iron overload and enhanced activity of some ROS-producing catabolic enzymes. PMID:25047818

  8. Brazil nut ingestion increased plasma selenium but had minimal effects on lipids, apolipoproteins, and high-density lipoprotein function in human subjects.

    PubMed

    Strunz, Célia C; Oliveira, Tatiane V; Vinagre, Juliana C M; Lima, Adriana; Cozzolino, Silvia; Maranhão, Raul C

    2008-03-01

    The Brazil nut (Bertholletia excelsa) of the Amazon region is consumed worldwide. It is rich in both monounsaturated fatty acids and polyunsaturated fatty acids and is known for its high selenium content. This study tested the hypothesis whether the consumption of this nut could affect the plasma lipids and apolipoproteins and some functional properties of the antiatherogenic high-density lipoprotein (HDL). Fifteen normolipidemic subjects aged 27.3 +/- 3.9 years and with body mass index of 23.8 +/- 2.8 kg/m(2) consumed 45 g of Brazil nuts per day during a 15-day period. On days 0 and 15, blood was collected for biochemical analysis, determination of HDL particle size, paraoxonase 1 activity, and lipid transfer from a lipoprotein-like nanoparticle to the HDL fraction. Brazil nut ingestion did not alter HDL, low-density lipoprotein cholesterol, triacylglycerols, apolipoprotein A-I, or apolipoprotein B concentrations. HDL particle diameter and the activity of antioxidative paraoxonase 1, mostly found in the HDL fraction, were also unaffected. Supplementation increased the reception of cholesteryl esters (P < .05) by the HDL yet did not alter the reception of phospholipids, free cholesterol, or triacylglycerols. As expected, plasma selenium was significantly increased. However, the consumption of Brazil nuts for short duration by normolipidemic subjects in comparable amounts to those tested for other nuts did not alter serum lipid profile. The only alteration in HDL function was the increase in cholesteryl ester transfer. This latter finding may be beneficial because it would improve the nonatherogenic reverse cholesterol transport pathway. PMID:19083402

  9. Apolipoprotein distribution in human lipoproteins separated by polyacrylamide gradient gel electrophoresis.

    PubMed

    Vézina, C A; Milne, R W; Weech, P K; Marcel, Y L

    1988-05-01

    The heterogeneity of serum lipoproteins (excluding very low density (VLDL) and intermediate density (IDL) lipoproteins) and that of lipoproteins secreted by HepG2 cells has been studied by immunoblot analysis of the apolipoprotein composition of the particles separated by polyacrylamide gradient gel electrophoresis (GGE) under nondenaturing conditions. The reactions of antibodies to apoA-I, apoA-II, apoE, apoB, apoD, and apoA-IV have revealed discrete bands of particles which differ widely in size and apolipoprotein composition. GGE of native serum lipoproteins demonstrated that apoA-II is present in lipoproteins of limited size heterogeneity (apparent molecular mass 345,000 to 305,000) and that apoB is present in low density lipoproteins (LDL) and absent from all smaller or denser lipoproteins. In contrast, serum apoA-I, E, D, and A-IV are present in very heterogeneous particles. Serum apoA-I is present mainly in particles of 305 to 130 kDa where it is associated with apoA-II, and in decreasing order of immunoreactivity in particles of 130-90 kDa, 56 kDa, 815-345 kDa, and finally within the size range of LDL, all regions where there is little detectable apoA-II. Serum apoE is present in three defined fractions, one within the size range of LDL, one containing heterogeneous particles between 640 and 345 kDa, and one defined fraction at 96 kDa. Serum apoD is also present in three defined fractions, one comigrating with LDL, one containing heterogeneous particles between 390 and 150 kDa, and one band on the migration front. Most of serum apoA-IV is contained in a band comigrating with albumin. GGE of centrifugally prepared LDL shows the presence of apoB, apoE, and apoD, but not that of apoA-I. However, the particles containing apoA-I, which, in serum, migrated within the LDL size range and as bands of 815 to 345 kDa, were recovered upon centrifugation in the d greater than 1.21 g/ml fraction. GGE of high density lipoproteins (HDL) indicated that most of apoA-I, A

  10. High molecular weight adiponectin reduces apolipoprotein B and E release in human hepatocytes

    SciTech Connect

    Neumeier, Markus; Sigruener, Alexander; Eggenhofer, Elke; Weigert, Johanna; Weiss, Thomas S.; Schaeffler, Andreas; Schlitt, Hans J.; Aslanidis, Charalampos; Piso, Pompiliu; Langmann, Thomas; Schmitz, Gerd; Schoelmerich, Juergen; Buechler, Christa . E-mail: christa.buechler@klinik.uni-regensburg.de

    2007-01-12

    Low circulating levels of high molecular weight adiponectin (HMW-Apm) have been linked to dyslipidaemia and systemic HMW-Apm negatively correlates with very low density lipoprotein (VLDL), apolipoprotein B (ApoB), and ApoE and is positively associated with ApoA-I. Therefore, it was investigated whether HMW-Apm alters the hepatic synthesis of ApoB, ApoE, and ApoA-I or the activity of the hepatic ATP-binding cassette transporter A1 (ABCA1), as the main determinant of plasma HDL. HMW-Apm reduces hepatic ApoB and ApoE release whereas ABCA1 protein, activity and ApoA-I were not altered. Global gene expression analysis revealed that hepatic nuclear factor 4-{alpha} (HNF4-{alpha}) and HNF4-{alpha} regulated genes like ApoB are downregulated by HMW-Apm and this was confirmed at the mRNA and protein level. Therefore it is concluded that HMW-adiponectin may ameliorate dyslipidaemia by reducing the hepatic release of ApoB and ApoE, whereas ABCA1 function and ApoA-I secretion are not influenced.

  11. Mechanism of lipid lowering in mice expressing human apolipoprotein A5

    SciTech Connect

    Fruchart-Najib, Jamila; Bauge, Eric; Niculescu, Loredan-Stefan; Pham, Tatiana; Thomas, Benoit; Rommens, Corinne; Majd, Zouher; Brewer, Bryan; Rubin, Edward M.; Pennacchio, Len A.; Fruchart, Jean-Charles

    2004-01-15

    Recently, we reported that apoAV plays key role in triglycerides lowering. Here, we attempted to determine the mechanism underlying this hypotriglyceridemic effect. We showed that triglyceride turnover is faster in hAPOA5 transgenic compared to wild type mice. Moreover, both apoB and apoCIII are decreased and LPL activity is increased in postheparin plasma of hAPOA5 transgenic mice. These data suggest a decrease in size and number of VLDL. To further investigate the mechanism of hAPOA5 in hyperlipidemic background, we intercrossed hAPOA5 and hAPOC3 transgenic mice. The effect resulted in a marked decreased of VLDL triglyceride, cholesterol, apolipoproteins B and CIII. In postprandial state, the triglyceride response is abolished in hAPOA5 transgenic mice. We demonstrated that in response to the fat load in hAPOA5XhAPOC3 mice, apoAV shifted from HDL to VLDL, probably to limit the elevation of triglycerides. In vitro, apoAV activates lipoprotein lipase. However, apoAV does not interact with LPL but interacts physically with apoCIII. This interaction does not seem to displace apoCIII from VLDL but may induce conformational change in apoCIII and consequently change in its function leading the activation of lipoprotein lipase.

  12. A Highly Expressed Human Protein, Apolipoprotein B-100, Serves as an Autoantigen in a Subgroup of Patients With Lyme Disease.

    PubMed

    Crowley, Jameson T; Drouin, Elise E; Pianta, Annalisa; Strle, Klemen; Wang, Qi; Costello, Catherine E; Steere, Allen C

    2015-12-01

    To discover novel autoantigens associated with Lyme arthritis (LA), we identified T-cell epitopes presented in vivo by human leukocyte antigen (HLA)-DR molecules in patients' inflamed synovial tissue or joint fluid and tested each epitope for autoreactivity. Using this approach, we identified the highly expressed human protein, apolipoprotein B-100 (apoB-100), as a target of T- and B-cell responses in a subgroup of LA patients. Additionally, the joint fluid of these patients had markedly elevated levels of apoB-100 protein, which may contribute to its autoantigenicity. In patients with antibiotic-refractory LA, the magnitude of apoB-100 antibody responses correlated with increased numbers of plasma cells in synovial tissue, greater numbers and activation of endothelial cells, and more synovial fibroblast proliferation. Thus, a subset of LA patients have high levels of apoB-100 in their joints and autoreactive T- and B-cell responses to the protein, which likely contributes to pathogenic autoimmunity in patients with antibiotic-refractory LA. PMID:26014802

  13. Characteristics of polymorphism at a VNTR locus 3' to the apolipoprotein B gene in five human populations.

    PubMed Central

    Deka, R; Chakraborty, R; DeCroo, S; Rothhammer, F; Barton, S A; Ferrell, R E

    1992-01-01

    We have analyzed the allele frequency distribution at the hypervariable locus 3' to the apolipoprotein B gene (ApoB 3' VNTR) in five well-defined human populations (Kacharis of northeast India, New Guinea Highlanders of Papua New Guinea, Dogrib Indians of Canada, Pehuenche Indians of Chile, and a relatively homogeneous Caucasian population of northern German extraction) by using the PCR technique. A total of 12 segregating alleles were detected in the pooled sample of 319 individuals. A fairly consistent bimodal pattern of allele frequency distribution, apparent in most of these geographically and genetically diverse populations, suggests that the ApoB 3' VNTR polymorphism predates the geographic dispersal of ancestral human populations. In spite of the observed high degree of polymorphism at this locus (expected heterozygosity levels 55%-78%), the genotype distributions in all populations (irrespective of their tribal or cosmopolitan nature) conform to their respective Hardy-Weinberg predictions. Furthermore, analysis of the congruence between expected heterozygosity and the observed number of alleles reveals that, in general, the allele frequency distributions at this locus are in agreement with the predictions of the classical mutation-drift models. The data also show that alleles that are shared by all populations have the highest average frequency within populations. These findings demonstrate the potential utility of highly informative hypervariable loci such as the ApoB 3' VNTR locus in population genetic research, as well as in forensic medicine and determination of biological relatedness of individuals. Images Figure 1 PMID:1463014

  14. DNase I- and micrococcal nuclease-hypersensitive sites in the human apolipoprotein B gene are tissue specific

    SciTech Connect

    Levy-Wilson, B.; Fortier, C.; Blackhart, B.D.; McCarthy, B.J.

    1988-01-01

    The authors mapped the DNase I- and micrococcal nuclease-hypersensitive sites present in the 5' end of the human apolipoprotein B (apo-B) gene in nuclei from cells expressing or not expressing the gene. Four DNase I-hypersensitive sites were found in nuclei from liver-derived HepG2 cells and intestine-derived CaCo-2 cells, which express the apo-B gene, but not in HeLa cells, which do not. These sites are located near positions -120, -440, -700, and +760 base pairs relative to the transcriptional start site. Undifferentiated CaCo-2 cells exhibited another site, near position -540. Six micrococcal nuclease-hypersensitive sites were found in nuclei from HepG2 and CaCo-2 cells, but not in HeLa cells or free DNA. These sites are located near positions -120, -390, -530, -700, -850, and +210. HepG2 cells exhibited another site, near position +460. Comparison of the DNA sequence of the 5' flanking regions of the human and mouse apo-B genes revealed a high degree of evolutionary conservation of short stretches of sequences in the immediate vicinity of each of the DNase I- and most of the micrococcal nuclease-hypersensitive sites.

  15. Human apolipoprotein E allele and docosahexaenoic acid intake modulate peripheral cholesterol homeostasis in mice.

    PubMed

    Pinçon, Anthony; Coulombe, Jean-Denis; Chouinard-Watkins, Raphaël; Plourde, Mélanie

    2016-08-01

    Carrying at least one apolipoprotein E ε4 allele (E4+) is the main genetic risk factor for Alzheimer's disease (AD). Epidemiological studies support that consuming fatty fish rich in docosahexaenoic acid (DHA; 22:6ω3) is protective against development of AD. However, this protective effect seems not to hold in E4+. The involvement of APOE genotype on the relationship between DHA intake and cognitive decline could be mediated through cholesterol. Many studies show a link between cholesterol metabolism and AD progression. In this study, we investigated whether cholesterol metabolism is improved in E3+ and E4+ mice consuming a diet rich in DHA. Plasma cholesterol was 36% lower in E4+ mice compared to E3+ mice fed the control diet (P=.02), and in the liver, there was a significant genotype effect where cholesterol levels were 18% lower in E4+ mice than E3+ mice. The low-density lipoprotein receptor was overexpressed in the liver of E4+ mice. Plasma cholesterol levels were 33% lower after the DHA diet (P=.02) in E3+ mice only, and there was a significant diet effect where cholesterol level was 67% lower in the liver of mice fed DHA. Mice fed the DHA diet also had 62% less lipolysis stimulated lipoprotein receptor expression in the liver compared to mice fed the control diet (P<.0001), but there was no genotype effect. These findings suggest that plasma and liver cholesterol homeostasis and the receptors regulating uptake of cholesterol in the liver are modulated differently and independently by APOE allele and DHA intake. PMID:27239755

  16. Triglyceride-rich lipoproteins inhibit cholesterol efflux to apolipoprotein (apo) A1 from human macrophage foam cells.

    PubMed

    Palmer, Anna M; Murphy, Nuala; Graham, Annette

    2004-03-01

    High circulating levels of triglyceride-rich lipoproteins (TGRL) represent an independent risk factor for coronary artery disease. Here, we show that TGRL inhibit the efflux of cholesterol from 'foam cell' macrophages to lipid-poor apolipoprotein (apo) A1, and may thereby inhibit arterial reverse cholesterol transport and promote the formation of atherosclerotic lesions. Human (THP-1) monocyte-derived macrophages were pre-incubated (48 h) with acetylated low-density lipoprotein (AcLDL) to provide a foam cell model of cholesterol efflux to apoA1. Pre-incubation of macrophage 'foam cells' with TGRL (0-200 microg/ml, 0-24 h) inhibited the efflux of exogenously radiolabelled ([3H]), endogenously synthesised ([14C]) and cellular cholesterol mass to lipid-poor apoA1, but not control medium, during a (subsequent) efflux period. This inhibition is dependent upon the length of prior exposure to, and concentration of, TGRL employed, but is independent of changes in intracellular triglyceride accumulation or turnover of the cholesteryl ester pool. Despite the negative impact of TGRL on cholesterol efflux, major proteins involved in this process--namely apoE, ABCA1, SR-B1 and caveolin-1--were unaffected by TGRL pre-incubation, suggesting that exposure to these lipoproteins inhibits an alternate, and possibly novel, anti-atherogenic pathway. PMID:15177121

  17. The Association of Human Apolipoprotein C-III Sialylation Proteoforms with Plasma Triglycerides

    PubMed Central

    Yassine, Hussein N.; Trenchevska, Olgica; Ramrakhiani, Ambika; Parekh, Aarushi; Koska, Juraj; Walker, Ryan W.; Billheimer, Dean; Reaven, Peter D.; Yen, Frances T.; Nelson, Randall W.; Goran, Michael I.; Nedelkov, Dobrin

    2015-01-01

    Introduction Apolipoprotein C-III (apoC-III) regulates triglyceride (TG) metabolism. In plasma, apoC-III exists in non-sialylated (apoC-III0a without glycosylation and apoC-III0b with glycosylation), monosialylated (apoC-III1) or disialylated (apoC-III2) proteoforms. Our aim was to clarify the relationship between apoC-III sialylation proteoforms with fasting plasma TG concentrations. Methods In 204 non-diabetic adolescent participants, the relative abundance of apoC-III plasma proteoforms was measured using mass spectrometric immunoassay. Results Compared with the healthy weight subgroup (n = 16), the ratios of apoC-III0a, apoC-III0b, and apoC-III1 to apoC-III2 were significantly greater in overweight (n = 33) and obese participants (n = 155). These ratios were positively correlated with BMI z-scores and negatively correlated with measures of insulin sensitivity (Si). The relationship of apoC-III1 / apoC-III2 with Si persisted after adjusting for BMI (p = 0.02). Fasting TG was correlated with the ratio of apoC-III0a / apoC-III2 (r = 0.47, p<0.001), apoC-III0b / apoC-III2 (r = 0.41, p<0.001), apoC-III1 / apoC-III2 (r = 0.43, p<0.001). By examining apoC-III concentrations, the association of apoC-III proteoforms with TG was driven by apoC-III0a (r = 0.57, p<0.001), apoC-III0b (r = 0.56. p<0.001) and apoC-III1 (r = 0.67, p<0.001), but not apoC-III2 (r = 0.006, p = 0.9) concentrations, indicating that apoC-III relationship with plasma TG differed in apoC-III2 compared with the other proteoforms. Conclusion We conclude that apoC-III0a, apoC-III0b, and apoC-III1, but not apoC- III2 appear to be under metabolic control and associate with fasting plasma TG. Measurement of apoC-III proteoforms can offer insights into the biology of TG metabolism in obesity. PMID:26633899

  18. Sphingosine 1-phosphate and its carrier apolipoprotein M in human sepsis and in Escherichia coli sepsis in baboons.

    PubMed

    Frej, Cecilia; Linder, Adam; Happonen, Kaisa E; Taylor, Fletcher B; Lupu, Florea; Dahlbäck, Björn

    2016-06-01

    Sphingosine 1-phosphate (S1P) is an important regulator of vascular integrity and immune cell migration, carried in plasma by high-density lipoprotein (HDL)-associated apolipoprotein M (apoM) and by albumin. In sepsis, the protein and lipid composition of HDL changes dramatically. The aim of this study was to evaluate changes in S1P and its carrier protein apoM during sepsis. For this purpose, plasma samples from both human sepsis patients and from an experimental Escherichia coli sepsis model in baboons were used. In the human sepsis cohort, previously studied for apoM, plasma demonstrated disease-severity correlated decreased S1P levels, the profile mimicking that of plasma apoM. In the baboons, a similar disease-severity dependent decrease in plasma levels of S1P and apoM was observed. In the lethal E. coli baboon sepsis, S1P decreased already within 6-8 hrs, whereas the apoM decrease was seen later at 12-24 hrs. Gel filtration chromatography of plasma from severe human or baboon sepsis on Superose 6 demonstrated an almost complete loss of S1P and apoM in the HDL fractions. S1P plasma concentrations correlated with the platelet count but not with erythrocytes or white blood cells. The liver mRNA levels of apoM and apoA1 decreased strongly upon sepsis induction and after 12 hr both were almost completely lost. In conclusion, during septic challenge, the plasma levels of S1P drop to very low levels. Moreover, the liver synthesis of apoM decreases severely and the plasma levels of apoM are reduced. Possibly, the decrease in S1P contributes to the decreased endothelial barrier function observed in sepsis. PMID:26990127

  19. Apolipoprotein E Variation at the Sequence Haplotype Level: Implications for the Origin and Maintenance of a Major Human Polymorphism

    PubMed Central

    Fullerton, Stephanie M.; Clark, Andrew G.; Weiss, Kenneth M.; Nickerson, Deborah A.; Taylor, Scott L.; Stengård, Jari H.; Salomaa, Veikko; Vartiainen, Erkki; Perola, Markus; Boerwinkle, Eric; Sing, Charles F.

    2000-01-01

    Three common protein isoforms of apolipoprotein E (apoE), encoded by the ε2, ε3, and ε4 alleles of the APOE gene, differ in their association with cardiovascular and Alzheimer's disease risk. To gain a better understanding of the genetic variation underlying this important polymorphism, we identified sequence haplotype variation in 5.5 kb of genomic DNA encompassing the whole of the APOE locus and adjoining flanking regions in 96 individuals from four populations: blacks from Jackson, MS (n=48 chromosomes), Mayans from Campeche, Mexico (n=48), Finns from North Karelia, Finland (n=48), and non-Hispanic whites from Rochester, MN (n=48). In the region sequenced, 23 sites varied (21 single nucleotide polymorphisms, or SNPs, 1 diallelic indel, and 1 multiallelic indel). The 22 diallelic sites defined 31 distinct haplotypes in the sample. The estimate of nucleotide diversity (site-specific heterozygosity) for the locus was 0.0005±0.0003. Sequence analysis of the chimpanzee APOE gene showed that it was most closely related to human ε4-type haplotypes, differing from the human consensus sequence at 67 synonymous (54 substitutions and 13 indels) and 9 nonsynonymous fixed positions. The evolutionary history of allelic divergence within humans was inferred from the pattern of haplotype relationships. This analysis suggests that haplotypes defining the ε3 and ε2 alleles are derived from the ancestral ε4s and that the ε3 group of haplotypes have increased in frequency, relative to ε4s, in the past 200,000 years. Substantial heterogeneity exists within all three classes of sequence haplotypes, and there are important interpopulation differences in the sequence variation underlying the protein isoforms that may be relevant to interpreting conflicting reports of phenotypic associations with variation in the common protein isoforms. PMID:10986041

  20. Fibrates increase human apolipoprotein A-II expression through activation of the peroxisome proliferator-activated receptor.

    PubMed Central

    Vu-Dac, N; Schoonjans, K; Kosykh, V; Dallongeville, J; Fruchart, J C; Staels, B; Auwerx, J

    1995-01-01

    In view of the evidence linking plasma high density lipoprotein (HDL)-cholesterol levels to a protective effect against coronary artery disease and the widespread use of fibrates in the treatment of hyperlipidemia, the goal of this study was to analyze the influence of fibrates on the expression of apolipoprotein (apo) A-II, a major protein constituent of HDL. Administration of fenofibrate (300 mg/d) to 16 patients with coronary artery disease resulted in a marked increase in plasma apo A-II concentrations (0.34 +/- 0.11 to 0.45 +/- 0.17 grams/liter; P < 0.01). This increase in plasma apo A-II was due to a direct effect on hepatic apo A-II production, since fenofibric acid induced apo A-II mRNA levels to 450 and 250% of control levels in primary cultures of human hepatocytes and in human hepatoblastoma HepG2 cells respectively. The induction in apo A-II mRNA levels was followed by an increase in apo A-II secretion in both cell culture systems. Transient transfection experiments of a reporter construct driven by the human apo A-II gene promoter indicated that fenofibrate induced apo A-II gene expression at the transcriptional level. Furthermore, several other peroxisome proliferators, such as the fibrate, Wy-14643, and the fatty acid, eicosatetraynoic acid (ETYA), also induced apo A-II gene transcription. Unilateral deletions and site-directed mutagenesis identified a sequence element located in the J-site of the apo A-II promoter mediating the responsiveness to fibrates and fatty acids. This element contains two imperfect half sites spaced by 1 oligonucleotide similar to a peroxisome proliferator responsive element (PPRE). Cotransfection assays showed that the peroxisome proliferator activated receptor (PPAR) transactivates the apo A-II promoter through this AII-PPRE. Gel retardation assays demonstrated that PPAR binds to the AII-PPRE with an affinity comparable to its binding affinity to the acyl coA oxidase (ACO)-PPRE. In conclusion, in humans fibrates increase

  1. Role of apolipoprotein E in febrile convulsion.

    PubMed

    Giray, Ozlem; Ulgenalp, Ayfer; Bora, Elçin; Uran, Nedret; Yilmaz, Ebru; Unalp, Aycan; Erçal, Derya

    2008-10-01

    Apolipoprotein E is consistently associated with the progression of some common human neurodegenerative diseases, e.g., epilepsy. We hypothesized that genetic variations in the apolipoprotein E gene have implications for susceptibility to, and prognoses in, febrile convulsion, which plays an apparent role in the development of epilepsy. We used the polymerase chain reaction and restriction enzyme digestion to characterize variations of the apolipoprotein E gene. Sixty-nine patients with febrile convulsion (simple/complex) and a corresponding cohort of healthy patients (n = 75) were used. There was no significant difference in genotypic distribution and allelic frequencies of the apolipoprotein E gene between the febrile convulsion and control groups. Comparing subpopulations of the febrile convulsion group (patients with simple and complex febrile convulsion), we noted that no patients with the epsilon3/epsilon4 genotype had complex febrile convulsions. The apolipoprotein E epsilon3/epsilon4 genotype was more frequently seen in the simple febrile than in the complicated febrile convulsion group (9 versus 0 patients, respectively). The data indicate an association with the epsilon3/epsilon4 genotype of the apolipoprotein E gene with a milder phenotype. Although apolipoprotein E4 is not a vulnerability factor regarding febrile convulsions, it seems effective in regard to prognoses. PMID:18805361

  2. Distinct Roles of Apolipoproteins A1 and E in the Modulation of High-Density Lipoprotein Composition and Function.

    PubMed

    Filou, Serafoula; Lhomme, Marie; Karavia, Eleni A; Kalogeropoulou, Christina; Theodoropoulos, Vassilis; Zvintzou, Evangelia; Sakellaropoulos, George C; Petropoulou, Peristera-Ioanna; Constantinou, Caterina; Kontush, Anatol; Kypreos, Kyriakos E

    2016-07-12

    In addition to high-density lipoprotein cholesterol (HDL-C) levels, HDL quality also appears to be very important for atheroprotection. Analysis of various clinical paradigms suggests that the lipid and apolipoprotein composition of HDL defines its size, shape, and functions and may determine its beneficial effects on human health. Previously, we reported that like apolipoprotein A-I (Apoa1), apolipoprotein E (Apoe) is also capable of promoting the de novo biogenesis of HDL with the participation of ATP binding cassette A lipid transporter member 1 (Abca1) and plasma enzyme lecithin:cholesterol acyltransferase (Lcat), in a manner independent of a functional Apoa1. Here, we performed a comparative analysis of the functions of these HDL subpopulations. Specifically, Apoe and Apoa1 double-deficient (Apoe(-/-) × Apoa1(-/-)) mice were infected with APOA1- or APOE3-expressing adenoviruses, and APOA1-containing HDL (APOA1-HDL) and APOE3-containing HDL (APOE3-HDL), respectively, were isolated and analyzed by biochemical and physicochemical methods. Western blot and lipidomic analyses indicated significant differences in the apolipoprotein and lipid composition of the two HDL species. Moreover APOE3-HDL presented a markedly reduced antioxidant potential and Abcg1-mediated cholesterol efflux capacity. Surprisingly, APOE3-HDL but not APOA1-HDL attenuated LPS-induced production of TNFα in RAW264.7 cells, suggesting that the anti-inflammatory effects of APOA1 are dependent on APOE expression. Taken together, our data indicate that APOA1 and APOE3 recruit different apolipoproteins and lipids on the HDL particle, leading to structurally and functionally distinct HDL subpopulations. The distinct role of these two apolipoproteins in the modulation of HDL functionality may pave the way toward the development of novel pharmaceuticals that aim to improve HDL functionality. PMID:27332083

  3. Serendipitous discovery and X-ray structure of a human phosphate binding apolipoprotein.

    PubMed

    Morales, Renaud; Berna, Anne; Carpentier, Philippe; Contreras-Martel, Carlos; Renault, Frédérique; Nicodeme, Murielle; Chesne-Seck, Marie-Laure; Bernier, François; Dupuy, Jérôme; Schaeffer, Christine; Diemer, Hélène; Van-Dorsselaer, Alain; Fontecilla-Camps, Juan C; Masson, Patrick; Rochu, Daniel; Chabriere, Eric

    2006-03-01

    We report the serendipitous discovery of a human plasma phosphate binding protein (HPBP). This 38 kDa protein is copurified with the enzyme paraoxonase. Its X-ray structure is similar to the prokaryotic phosphate solute binding proteins (SBPs) associated with ATP binding cassette transmembrane transporters, though phosphate-SBPs have never been characterized or predicted from nucleic acid databases in eukaryotes. However, HPBP belongs to the family of ubiquitous eukaryotic proteins named DING, meaning that phosphate-SBPs are also widespread in eukaryotes. The systematic absence of complete genes for eukaryotic phosphate-SBP from databases is intriguing, but the astonishing 90% sequence conservation between genes belonging to evolutionary distant species suggests that the corresponding proteins play an important function. HPBP is the only known transporter capable of binding phosphate ions in human plasma and may become a new predictor of or a potential therapeutic agent for phosphate-related diseases such as atherosclerosis. PMID:16531243

  4. AI/COAG, A Knowledge-Based System for Consultation about Human Hemostasis Disorders: Progress Report

    PubMed Central

    Lindberg, Donald A. B.; Gaston, Lamont W.; Kingsland, Lawrence C.; Vanker, Anthony D.

    1981-01-01

    AI/Coag is an interactive, knowledge based computer system which reports, analyzes and interprets clinical blood coagulation laboratory studies. The laboratory subsystem presently deals with six tests: platelet count, bleeding time, prothrombin time, activated partial thromboplastin time, thrombin time, and urea clot solubility. This subsystem returns a detailed analysis and interpretation of the test results. It also offers further information on specific aspects of the interpretation in the form of “Tell-Me-More” (TMM) items. Individual TMM items may be requested by the user during each interpretive session. Also available are the literature sources underlying the knowledge base, stored by the subsystem as “Tell-Me-Reference” (TMR) items. A second subsystem, under development, contains a detailed hemostasis history questionnaire, the answers from which will be analyzed in conjunction with results from the laboratory subsystem to provide a definitive interpretation or to suggest further laboratory tests.

  5. Characterization of the metabolic syndrome by apolipoproteins in the Oklahoma Cherokee.

    PubMed

    Alaupovic, Petar; Blackett, Piers; Wang, Wenyu; Lee, Elisa

    2008-01-01

    Native Americans are susceptible to type 2 diabetes and associated cardiovascular risk that precedes the diabetes. Nondiabetic Cherokee adolescents and young adults were studied for association of apolipoproteins A-I, B, and C-III with the metabolic syndrome, homeostasis model assessment-insulin resistance (HOMA-IR), and body mass index. Apolipoproteins, lipids, selected ratios, and HOMA-IR changed adversely according to the number of metabolic syndrome criteria present (P<.001 for trend). Logistic regression showed heparin-precipitated apolipoprotein C-III, apolipoprotein C-III bound to apolipoprotein B-containing lipoproteins, to be a significant predictor of the metabolic syndrome in the adolescents and adults, and it appears to be more strongly associated than apolipoprotein B: apolipoprotein A-I. Regression modeling with components of the syndrome as the dependent variables showed that they were all significantly associated with heparin-precipitated apolipoprotein C-III except for fasting blood glucose. The Cherokee have a high prevalence of the metabolic syndrome, which is associated with atherosclerotic lipoprotein particles containing apolipoprotein C-III and B. PMID:19040586

  6. Molecular cloning and expression of partial cDNAs and deduced amino acid sequence of a carboxyl-terminal fragment of human apolipoprotein B-100.

    PubMed Central

    Wei, C F; Chen, S H; Yang, C Y; Marcel, Y L; Milne, R W; Li, W H; Sparrow, J T; Gotto, A M; Chan, L

    1985-01-01

    Apolipoprotein (apo) B-100 cDNAs were identified in a human liver cDNA library cloned in the expression vector lambda gt11. The beta-galactosidase-apoB-100 fusion protein was detected by two independently produced low density lipoprotein polyclonal antisera and by three apoB-100 monoclonal antibodies that crossreact with apoB-74. It was not recognized by two apoB-100 monoclonal antibodies that crossreact with apoB-26. The longest clone, lambda B8, was completely sequenced. It contains a 2.8-kilobase DNA fragment containing the codons for the carboxyl-terminal 836 amino acid residues of apo-B-100, as well as the 3' untranslated region of apoB-100 mRNA. We have thus mapped apoB-74 to the carboxyl-terminal portion of apoB-100. The deduced amino acid sequence of the cloned DNA matches the sequences of 14 apoB-100 peptides determined in our laboratory. Minor differences in amino acid sequence were noted in three of the peptides, suggesting polymorphism of apoB-100 at the protein and DNA levels. Secondary structure predictions reveal an unusual pattern for apolipoproteins, consisting of beta-structure (24%), alpha-helical content (33%), and random structure (30%). Ten amphipathic helical regions of 10-24 residues were identified. This carboxyl-terminal fragment of apoB-100 is considerably more hydrophobic than other apolipoproteins with known structure. Its lipid binding regions might include stretches of highly hydrophobic beta-sheets as well as amphipathic helices. Our findings on apoB structure might be important for understanding the role of apoB-100-containing lipoproteins in atherosclerosis. PMID:2932736

  7. Relationship between apolipoprotein concentrations and HDL subclasses distribution.

    PubMed

    Tian, Li; Fu, Mingde; Jia, Lianqun; Xu, Yanhua; Long, Shiyin; Tian, Haoming; Tian, Ying

    2007-05-01

    Alterations in plasma apolipoproteins levels can influence the composition, content, and distribution of plasma lipoproteins that affect the risk of atherosclerosis. This study assessed the relationship between plasma apolipoproteins levels, mainly apoAI, and HDL subclass distribution. The contents of plasma HDL subclasses were determined by two-dimensional gel electrophoresis coupled with immunodetection in 545 Chinese subjects. Compared with a low apoAI group, the contents of all HDL subclasses increased significantly both in middle and high apoAI group, and the contents of large-sized HDL(2b) increased more significantly relative to those of small-sized prebeta(1)-HDL in a high apoAI group. When apoAI and HDL-C levels increased simultaneously, in comparison to a low apoAI along with HDL-C concentration group, a significant increase (116%) was shown in HDL2b but only a slight increase (26%) in prebeta1-HDL. In addition, Pearson correlation analysis revealed that apoAI levels were positively and significantly correlated with all HDL subclasses. Multiple liner regression demonstrated that the apoAI concentrations were the most powerful predictor for HDL subclass distribution. With the elevation of apoAI concentrations, the contents of all HDL subclasses increased successively and significantly, especially, an increase in large-sized HDL(2b). Further, when apoAI and HDL-C concentrations increased simultaneously, the shift to larger HDL size was more obvious. Which, in turn, indicated that HDL maturation might be enhanced and, the reverse cholesterol transport might be strengthened along with apoAI levels which might be a more powerful factor influencing the distribution of HDL subclasses. PMID:17476546

  8. Real time magnetic resonance imaging of apo AI metabolism in vivo

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Apolipoprotein AI (apo AI) plays a key role in maintaining cardiovascular health and constitutes the major lipoprotein component in high density lipoproteins (HDL). It metabolism, however, follows a complex pathway. Synthesized in the liver and intestines, its becomes lipidated by its interaction w...

  9. The gender-specific apolipoprotein E genotype influence on the distribution of plasma lipids and apolipoproteins in the population of Rochester, Minnesota. II. Regression relationships with concomitants

    SciTech Connect

    Reilly, S.L.; Sing, C.F. ); Ferrell, R.E. ); Kottke, B.A. )

    1992-12-01

    The influence of the apolipoprotein E (Apo E) polymorphism and gender on the regression relationships between each of nine plasma lipid and apolipoprotein traits (total cholesterol; ln triglycerides; high-density-lipoprotein chloesterol; apolipoproteins AI, AII, B, and CII; ln CIII; and ln E) and four concomitants (age, weight, waist-to-hip ratio, and smoking) was studied in 507 unrelated individuals representative of the adult population of Rochester, MN. Analyses are presented separately for females and males. Each lipid and apolipoprotein trait exhibited at least one Apo E genotype-specific regression relationship with the concomitants investigated in this study. In most cases the heterogeneity of regression was associated with differences between the [var epsilon]32 and [var epsilon]33 genotype. This study documents that the influence of Apo E genotype on average levels of plasma lipids and apolipoproteins varies among subdivisions of the population defined by age, body size, and smoking status. 61 refs., 1 fig., 5 tabs.

  10. Human factors involvement in bringing the power of AI to a heterogeneous user population

    NASA Technical Reports Server (NTRS)

    Czerwinski, Mary; Nguyen, Trung

    1994-01-01

    The Human Factors involvement in developing COMPAQ QuickSolve, an electronic problem-solving and information system for Compaq's line of networked printers, is described. Empowering customers with expert system technology so they could solve advanced networked printer problems on their own was a major goal in designing this system. This process would minimize customer down-time, reduce the number of phone calls to the Compaq Customer Support Center, improve customer satisfaction, and, most importantly, differentiate Compaq printers in the marketplace by providing the best, and most technologically advanced, customer support. This represents a re-engineering of Compaq's customer support strategy and implementation. In its first generation system, SMART, the objective was to provide expert knowledge to Compaq's help desk operation to more quickly and correctly answer customer questions and problems. QuickSolve is a second generation system in that customer support is put directly in the hands of the consumers. As a result, the design of QuickSolve presented a number of challenging issues. Because the produce would be used by a diverse and heterogeneous set of users, a significant amount of human factors research and analysis was required while designing and implementing the system. Research that shaped the organization and design of the expert system component as well.

  11. Targeting nanodisks via a single chain variable antibody - Apolipoprotein chimera

    SciTech Connect

    Iovannisci, David M.; Beckstead, Jennifer A.; Ryan, Robert O.

    2009-02-06

    Nanodisks (ND) are nanometer scale complexes of phospholipid and apolipoprotein that have been shown to function as drug delivery vehicles. ND harboring significant quantities of the antifungal agent, amphotericin B, or the bioactive isoprenoid, all trans retinoic acid, have been generated and characterized. As currently formulated, ND possess limited targeting capability. In this study, we constructed a single chain variable antibody (scFv).apolipoprotein chimera and assessed the ability of this fusion protein to form ND and recognize the antigen to which the scFv is directed. Data obtained revealed that {alpha}-vimentin scFv.apolipoprotein A-I is functional in ND formation and antigen recognition, opening the door to the use of such chimeras in targeting drug-enriched ND to specific tissues.

  12. New potential role of serum apolipoprotein E mediated by its binding to clumping factor A during Staphylococcus aureus invasive infections to humans

    PubMed Central

    Hair, Pamela S.; Nyalwidhe, Julius O.; Cunnion, Kenji M.

    2015-01-01

    Staphylococcus aureus is a crucial human pathogen expressing various immune-evasion proteins that interact with the host-cell molecules. Clumping factor A (ClfA) is a microbial surface protein that promotes S. aureus binding to fibrinogen, and is associated with septic arthritis and infective endocarditis. In order to identify the major human serum proteins that bind the ClfA, we utilized recombinant ClfA region A in a plate-based assay. SDS-PAGE analysis of the bound proteins yielded five prominent bands, which were analysed by MS yielding apolipoprotein E (ApoE) as the predominant protein. ClfA-sufficient S. aureus bound purified ApoE by more than one log greater than an isogenic ClfA-deficient mutant. An immunodot-blot assay yielded a linearity model for ClfA binding to human ApoE with a stoichiometric-binding ratio of 1.702 at maximal Pearson's correlation coefficient (0.927). These data suggest that ApoE could be a major and novel binding target for the S. aureus virulence factor ClfA. Thus, ClfA recruitment of serum ApoE to the S. aureus surface may sequester ApoE and blunt its host defence function against S. aureus-invasive infections to humans. In this context, compounds that can block or suppress ClfA binding to ApoE might be utilized as prophylactic or therapeutic agents. PMID:25878259

  13. New potential role of serum apolipoprotein E mediated by its binding to clumping factor A during Staphylococcus aureus invasive infections to humans.

    PubMed

    Elkhatib, Walid F; Hair, Pamela S; Nyalwidhe, Julius O; Cunnion, Kenji M

    2015-04-01

    Staphylococcus aureus is a crucial human pathogen expressing various immune-evasion proteins that interact with the host-cell molecules. Clumping factor A (ClfA) is a microbial surface protein that promotes S. aureus binding to fibrinogen, and is associated with septic arthritis and infective endocarditis. In order to identify the major human serum proteins that bind the ClfA, we utilized recombinant ClfA region A in a plate-based assay. SDS-PAGE analysis of the bound proteins yielded five prominent bands, which were analysed by MS yielding apolipoprotein E (ApoE) as the predominant protein. ClfA-sufficient S. aureus bound purified ApoE by more than one log greater than an isogenic ClfA-deficient mutant. An immunodot-blot assay yielded a linearity model for ClfA binding to human ApoE with a stoichiometric-binding ratio of 1.702 at maximal Pearson's correlation coefficient (0.927). These data suggest that ApoE could be a major and novel binding target for the S. aureus virulence factor ClfA. Thus, ClfA recruitment of serum ApoE to the S. aureus surface may sequester ApoE and blunt its host defence function against S. aureus-invasive infections to humans. In this context, compounds that can block or suppress ClfA binding to ApoE might be utilized as prophylactic or therapeutic agents. PMID:25878259

  14. Characterization of five new mutants in the carboxyl-terminal domain of human apolipoprotein E: No cosegregation with severe hyperlipidemia

    SciTech Connect

    Maagdenberg, A.M.J.M. van den; Bruijn, I.H. de; Hofker, M.H.; Frants, R.R. ); Knijff, P. de; Smelt, A.H.M.; Leuven, J.A.G.; van't Hooft, F.; Assmann, G.; Havekes, L.M. ); Weng, Wei; Funke, H. )

    1993-05-01

    Assessment of the apolipoprotein E (apoE) phenotype by isoelectric focusing of both hyperlipidemic and normolipidemic individuals identified five new variants. All mutations were confined to the downstream part of the APOE gene by using denaturing gradient gel electrophoresis (DGGE). Sequence analysis revealed five new mutations causing unique amino acid substitutions in the carboxyl-terminal part of the protein containing the putative lipid-binding domain. Three hyperlipoproteinemic probands were carriers of the APOE*2(Va1236[r arrow]Glu) allele, the APOE*3(Cys112-Arg; Arg251[r arrow]Gly) allele, or the APOE*1(Arg158[r arrow]Cys; Leu252[r arrow]Glu) allele. DGGE of the region encoding the receptor-binding domain was useful for haplotyping the mutations at codons 112 and 158. Family studies failed to demonstrate cosegregation between the new mutations and severe hyperlipoproteinemia, although a number of carriers for the APOE*3(Cys112[r arrow]Arg; Arg251[r arrow]Gly) allele and the APOE*1(Arg158-Cys; Leu252[r arrow]Glu) allele expressed hypertriglyceridemia and/ or hypercholesterolemia. Two other mutant alleles, APOE*4[sup [minus

  15. Differentially charged isoforms of apolipoprotein E from human blood are potential biomarkers of Alzheimer’s disease

    PubMed Central

    2014-01-01

    Introduction Alzheimer’s disease (AD) is the major cause of dementia among the elderly. Finding blood-based biomarkers for disease diagnosis and prognosis is urgently needed. Methods We studied protein distributions in brain tissues, cerebrospinal fluid (CSF), and blood of AD patients by using proteomics and a new proteomic method that we call “2D multiplexed Western blot” (2D mxWd). This method allows us to determine in multiple samples the electrophoretic patterns of protein isoforms with different isoelectric points. Results Apolipoprotein E (ApoE) displays a unique distribution of electrophoretic isoforms in the presence of AD and also a unique pattern specific to the APOE genotype. Conclusions The isoelectric distribution of differentially charged ApoE isoforms was used to determine the presence of AD in a small group of samples. Further studies are needed to validate their use as predictors of disease onset and progression, and as biomarkers for determining the efficacy of therapeutic treatments. PMID:25478016

  16. Zebrafish as a model for apolipoprotein biology: comprehensive expression analysis and a role for ApoA-IV in regulating food intake

    PubMed Central

    Otis, Jessica P.; Zeituni, Erin M.; Thierer, James H.; Anderson, Jennifer L.; Brown, Alexandria C.; Boehm, Erica D.; Cerchione, Derek M.; Ceasrine, Alexis M.; Avraham-Davidi, Inbal; Tempelhof, Hanoch; Yaniv, Karina; Farber, Steven A.

    2015-01-01

    Improved understanding of lipoproteins, particles that transport lipids throughout the circulation, is vital to developing new treatments for the dyslipidemias associated with metabolic syndrome. Apolipoproteins are a key component of lipoproteins. Apolipoproteins are proteins that structure lipoproteins and regulate lipid metabolism through control of cellular lipid exchange. Constraints of cell culture and mouse models mean that there is a need for a complementary model that can replicate the complex in vivo milieu that regulates apolipoprotein and lipoprotein biology. Here, we further establish the utility of the genetically tractable and optically clear larval zebrafish as a model of apolipoprotein biology. Gene ancestry analyses were implemented to determine the closest human orthologs of the zebrafish apolipoprotein A-I (apoA-I), apoB, apoE and apoA-IV genes and therefore ensure that they have been correctly named. Their expression patterns throughout development were also analyzed, by whole-mount mRNA in situ hybridization (ISH). The ISH results emphasized the importance of apolipoproteins in transporting yolk and dietary lipids: mRNA expression of all apolipoproteins was observed in the yolk syncytial layer, and intestinal and liver expression was observed from 4–6 days post-fertilization (dpf). Furthermore, real-time PCR confirmed that transcription of three of the four zebrafish apoA-IV genes was increased 4 hours after the onset of a 1-hour high-fat feed. Therefore, we tested the hypothesis that zebrafish ApoA-IV performs a conserved role to that in rat in the regulation of food intake by transiently overexpressing ApoA-IVb.1 in transgenic larvae and quantifying ingestion of co-fed fluorescently labeled fatty acid during a high-fat meal as an indicator of food intake. Indeed, ApoA-IVb.1 overexpression decreased food intake by approximately one-third. This study comprehensively describes the expression and function of eleven zebrafish apolipoproteins

  17. Zebrafish as a model for apolipoprotein biology: comprehensive expression analysis and a role for ApoA-IV in regulating food intake.

    PubMed

    Otis, Jessica P; Zeituni, Erin M; Thierer, James H; Anderson, Jennifer L; Brown, Alexandria C; Boehm, Erica D; Cerchione, Derek M; Ceasrine, Alexis M; Avraham-Davidi, Inbal; Tempelhof, Hanoch; Yaniv, Karina; Farber, Steven A

    2015-03-01

    Improved understanding of lipoproteins, particles that transport lipids throughout the circulation, is vital to developing new treatments for the dyslipidemias associated with metabolic syndrome. Apolipoproteins are a key component of lipoproteins. Apolipoproteins are proteins that structure lipoproteins and regulate lipid metabolism through control of cellular lipid exchange. Constraints of cell culture and mouse models mean that there is a need for a complementary model that can replicate the complex in vivo milieu that regulates apolipoprotein and lipoprotein biology. Here, we further establish the utility of the genetically tractable and optically clear larval zebrafish as a model of apolipoprotein biology. Gene ancestry analyses were implemented to determine the closest human orthologs of the zebrafish apolipoprotein A-I (apoA-I), apoB, apoE and apoA-IV genes and therefore ensure that they have been correctly named. Their expression patterns throughout development were also analyzed, by whole-mount mRNA in situ hybridization (ISH). The ISH results emphasized the importance of apolipoproteins in transporting yolk and dietary lipids: mRNA expression of all apolipoproteins was observed in the yolk syncytial layer, and intestinal and liver expression was observed from 4-6 days post-fertilization (dpf). Furthermore, real-time PCR confirmed that transcription of three of the four zebrafish apoA-IV genes was increased 4 hours after the onset of a 1-hour high-fat feed. Therefore, we tested the hypothesis that zebrafish ApoA-IV performs a conserved role to that in rat in the regulation of food intake by transiently overexpressing ApoA-IVb.1 in transgenic larvae and quantifying ingestion of co-fed fluorescently labeled fatty acid during a high-fat meal as an indicator of food intake. Indeed, ApoA-IVb.1 overexpression decreased food intake by approximately one-third. This study comprehensively describes the expression and function of eleven zebrafish apolipoproteins and

  18. Roles of human apolipoprotein E in the infectivity and replication of hepatitis C virus genotype 2a.

    PubMed

    Jung, Bo-Kyoung; Kim, Hye-Ran; Park, Gyu-Nam; Luo, Guangxiang; Chang, Kyung-Soo

    2016-06-01

    Hepatitis C virus (HCV) infection is associated with lipoproteins, and apolipoprotein E (apoE) plays an essential role in infectious HCV particles. Although the role of apoE in HCV infection is well known, its role in the replication of HCV remains unclear. The aims of this study were to determine the role of apoE in the RNA replication of major HCV genotypes 1b and 2a, and to determine whether this role is HCVgenotype-dependent using HCV genotype 1b replicon cells and HCV genotype 2a producing (HP) cells. HCV infection was blocked in Huh7.5 cells treated with low-density lipoproteins, very low-density lipoproteins, or apoE3. An apoE3-specific monoclonal antibody also efficiently neutralized HCV infectivity, and HCV infection was dramatically suppressed by the knockdown of apoE expression with an apoE-specific small interfering RNA, suggesting a requirement for apoE in infectious HCV particles. HCV RNA replication was not affected in HP cells treated with each apoE isoform or transfected with apoE-specific siRNAs. However, the knockdown of apoE expression suppressed RNA replication of HCV genotype 1b. The siRNA-mediated knockdown of apoE, apoA1, and apoB expression also suppressed the RNA replication of HCV genotype 1b, but not that of HCV genotype 2a. Taken together, these findings indicate that apoE plays an important role in HCV genotype 2a infection and in HCV genotype 1b RNA replication, but not in the replication of HCV genotype 2a. These results provide important information for the future development of HCV-genotypespecific anti-HCV agents. PMID:27225463

  19. Independent effects of apolipoprotein AV and apolipoprotein CIII on plasma triglyceride concentrations

    SciTech Connect

    Baroukh, Nadine N.; Bauge, Eric; Akiyama, Jennifer; Chang, Jessie; Fruchart, Jean-Charles; Rubin, Edward M.; Fruchart, Jamila; Pennacchio, Len A.

    2003-08-15

    Both the apolipoprotein A5 and C3 genes have repeatedly been shown to play an important role in determining plasma triglyceride concentrations in humans and mice. In mice, transgenic and knockout experiments indicate that plasma triglyceride levels are negatively and positively correlated with APOA5 and APOC3 expression, respectively. In humans, common polymorphisms in both genes have also been associated with plasma triglyceride concentrations. The evolutionary relationship among these two apolipoprotein genes and their close proximity on human chromosome 11q23 have largely precluded the determination of their relative contribution to altered Both the apolipoprotein A5 and C3 genes have repeatedly been shown to play an important role in determining plasma triglyceride concentrations in humans and mice. In mice, transgenic and knockout experiments indicate that plasma triglyceride levels are negatively and positively correlated with APOA5 and APOC3 expression, respectively. In humans, common polymorphisms in both genes have also been associated with plasma triglyceride concentrations. The evolutionary relationship among these two apolipoprotein genes and their close proximity on human chromosome 11q23 have largely precluded the determination of their relative contribution to altered triglycerides. To overcome these confounding factors and address their relationship, we generated independent lines of mice that either over-expressed (''double transgenic'') or completely lacked (''double knockout'') both apolipoprotein genes. We report that both ''double transgenic'' and ''double knockout'' mice display intermedia tetriglyceride concentrations compared to over-expression or deletion of either gene alone. Furthermore, we find that human ApoAV plasma protein levels in the ''double transgenic'' mice are approximately 500-fold lower than human ApoCIII levels, supporting ApoAV is a potent triglyceride modulator despite its low concentration. Together, these data indicate

  20. Apolipoprotein B100

    MedlinePlus

    ... 2011:chap 47. Robinson JG. What is the role of advanced lipoprotein analysis in practice? J Am Coll Cardiol. Dec 2012;60(25):2607-2615. Semenkovich, CF. Disorders of lipid metabolism. In: Goldman L, Schafer AI, eds. Goldman's Cecil ...

  1. Localization and regulation of the human very low density lipoprotein/apolipoprotein-E receptor: trophoblast expression predicts a role for the receptor in placental lipid transport.

    PubMed

    Wittmaack, F M; Gåfvels, M E; Bronner, M; Matsuo, H; McCrae, K R; Tomaszewski, J E; Robinson, S L; Strickland, D K; Strauss, J F

    1995-01-01

    The very low density lipoprotein/apolipoprotein-E receptor (VLDLR) is the newest member of the low density lipoprotein receptor (LDLR) family. Very little is known about VLDLR localization and regulation. Immunohistochemical analysis of human placenta with a specific polyclonal antibody detected VLDLR in syncytiotrophoblast and intermediate trophoblast cells. VLDLR transcripts were also localized in these cells by in situ hybridization histochemistry. In addition, VLDLR messenger RNA (mRNA) was detected in villous core endothelial cells and cells appearing to be Hofbauer cells. Northern blot analysis of placenta revealed a 2.6-fold increase in VLDLR mRNA at term compared to that in the first trimester. The regulation of VLDLR expression was studied in JEG-3 and BeWo choriocarcinoma cells, two trophoblast-derived cell lines. Treatment of these cells with 8-bromo-cAMP caused a profound suppression of VLDLR message, whereas LDLR transcripts were increased. Incubation of JEG-3 cells with 25-hydroxycholesterol did not lead to sterol negative feedback on VLDLR gene expression, unlike LDLR mRNA, which declined markedly. Insulin (200 mg/L) up-regulated VLDLR message in JEG-3 cells 2-fold, as did the fibrate hypolipidemic drug, clofibric acid. We conclude that 1) VLDLR is expressed in human placental trophoblast cells in a pattern consistent with a role in placental lipid transport; 2) VLDLR expression is high at term relative to that in the first trimester; and 3) the trophoblast VLDLR is subject to down-regulation by cAMP and up-regulation by insulin and fibrate hypolipidemic drugs. PMID:7828550

  2. Phenotypes of apolipoprotein B and apolipoprotein E after liver transplantation.

    PubMed Central

    Linton, M F; Gish, R; Hubl, S T; Bütler, E; Esquivel, C; Bry, W I; Boyles, J K; Wardell, M R; Young, S G

    1991-01-01

    Apolipoprotein (apo) E and the two B apolipoproteins, apoB48 and apoB100, are important proteins in human lipoprotein metabolism. Commonly occurring polymorphisms in the genes for apoE and apoB result in amino acid substitutions that produce readily detectable phenotypic differences in these proteins. We studied changes in apoE and apoB phenotypes before and after liver transplantation to gain new insights into apolipoprotein physiology. In all 29 patients that we studied, the postoperative serum apoE phenotype of the recipient, as assessed by isoelectric focusing, converted virtually completely to that of the donor, providing evidence that greater than 90% of the apoE in the plasma is synthesized by the liver. In contrast, the cerebrospinal fluid apoE phenotype did not change to the donor's phenotype after liver transplantation, indicating that most of the apoE in CSF cannot be derived from the plasma pool and therefore must be synthesized locally. The apoB100 phenotype (assessed with immunoassays using monoclonal antibody MB19, an antibody that detects a two-allele polymorphism in apoB) invariably converted to the phenotype of the donor. In four normolipidemic patients, we determined the MB19 phenotype of both the apoB100 and apoB48 in the "chylomicron fraction" isolated from plasma 3 h after a fat-rich meal. Interestingly, the apoB100 in the chylomicron fraction invariably had the phenotype of the donor, indicating that the vast majority of the large, triglyceride-rich apoB100-containing lipoproteins that appear in the plasma after a fat-rich meal are actually VLDL of hepatic origin. The MB19 phenotype of the apoB48 in the plasma chylomicron fraction did not change after liver transplantation, indicating that almost all of the apoB48 in plasma chylomicrons is derived from the intestine. These results were consistent with our immunocytochemical studies on intestinal biopsy specimens of organ donors; using apoB-specific monoclonal antibodies, we found evidence for

  3. Apolipoprotein L-I Promotes Trypanosome Lysis by Forming Pores in Lysosomal Membranes

    NASA Astrophysics Data System (ADS)

    Pérez-Morga, David; Vanhollebeke, Benoit; Paturiaux-Hanocq, Françoise; Nolan, Derek P.; Lins, Laurence; Homblé, Fabrice; Vanhamme, Luc; Tebabi, Patricia; Pays, Annette; Poelvoorde, Philippe; Jacquet, Alain; Brasseur, Robert; Pays, Etienne

    2005-07-01

    Apolipoprotein L-I is the trypanolytic factor of human serum. Here we show that this protein contains a membrane pore-forming domain functionally similar to that of bacterial colicins, flanked by a membrane-addressing domain. In lipid bilayer membranes, apolipoprotein L-I formed anion channels. In Trypanosoma brucei, apolipoprotein L-I was targeted to the lysosomal membrane and triggered depolarization of this membrane, continuous influx of chloride, and subsequent osmotic swelling of the lysosome until the trypanosome lysed.

  4. Fatty acids bound to human serum albumin and its structural variants modulate apolipoprotein B secretion in HepG2 cells.

    PubMed

    Ha, Ji-Sook; Theriault, Andre; Bhagavan, Nadhipuram V; Ha, Chung-Eun

    2006-07-01

    Epidemiologic studies have shown an inverse relationship between human serum albumin (HSA) levels and coronary heart disease (CHD). However, no mechanisms have been identified to explain this relationship. We hypothesized that this relationship is due to differences in binding affinity of fatty acids to HSA and subsequent atherogenic lipoprotein synthesis and secretion from hepatocytes. To test our hypothesis we undertook the current study. Using HepG2 cells, we demonstrated that oleic acid (OA) bound to HSA in a molar ratio of 4:1 and after incubation for 24 h stimulated apolipoprotein B (apoB) secretion. We also tested whether mutant forms of HSA could alter the binding affinity for fatty acids and change the availability of substrate for lipoprotein secretion. Based on the results obtained in this study using 11 HSA mutant proteins complexed with OA, we were able to classify into three major mutant groups based on their effects on apoB secretion. One group in particular (R410Q/Y411W, R410A/Y411A, and W214L/Y411W) showed a significantly diminished effect on apoB secretion when compared to the wild type HSA/OA complex. Furthermore, the amount of free OA internalized in HepG2 cells in the presence of HSA mutant proteins was in good agreement with the effects seen on apoB secretion by the various HSA mutants. This suggests that some mutant forms of HSA might potentially bind fatty acids with a much higher binding affinity and thus deprive fatty acids available for lipoprotein assembly in hepatocytes. In conclusion, our data illustrate that certain HSA polymorphic forms may be protective against the development of CHD and warrants further investigation. PMID:16843720

  5. Comparison of Serum Apolipoproteins and Traditional Lipids in Eyes with Diabetic Retinopathy in Indian Population: A Case Series

    PubMed Central

    Prakash, Gunjan; Agrawal, Rachit; Satsangi, S. K.; Prakash, Shikha

    2016-01-01

    Purpose: To review the associations of serum lipoproteins and apolipoproteins with diabetic retinopathy (DR). Materials and Methods: This was a cross-sectional study of patients of DR. DR was graded according to modified Airlie House Classification system. Traditional serum lipids (total, low-density lipoprotein [LDL], and high-density lipoprotein [HDL] cholesterol and triglycerides [TGs]), apolipoprotein AI (apoAI), apolipoprotein B (apoB), and apoB-to-apoAI ratios were assessed. The analysis of variance test was applied. P < 0.05 was considered statistically significant, and P < 0.001 was considered highly significant. Results: Twenty-four patients with DR were evaluated. Serum apoAI was statistically significantly associated with a reduced likelihood of having more severe DR levels (P < 0.001). Increasing levels of apoB (P < 0.001) and apoB-to-apoAI ratio (P < 0.001) were statistically significantly associated with increasing DR severity levels. The association of total (P > 0.05) and LDL cholesterol (P > 0.05) with severity of DR was not statistically significant. HDL cholesterol levels were inversely associated with the severity of DR (P < 0.05). TGs were also statistically significantly associated with the severity of DR (P < 0.05). Conclusion: Serum apolipoprotein levels may be stronger biomarkers of DR than traditional lipids. PMID:27162455

  6. Measurment of rhesus monkey (Macaca mulatta) apolipoprotein B in serum by radioimmunoassay: comparison of immunoreactivities of rhesus and human low density lipoproteins.

    PubMed

    Karlin, J B; Juhn, D J; Fless, G; Scanu, A M; Rubenstein, A H

    1978-02-01

    A sensitive and specific double antibody radio-immunoassay for the major apolipoprotein (apoB) of rhesus (Macaca mulatta) serum very low density lipoprotein (VLDL) and low density lipoprotein (LDL) is described. The anti-serum was raised to LDL (d 1.030-1.040 g/ml) and the LDL(2) (d 1.020-1.050 g/ml) was labeled with (125)I by the chloramine-T or iodine monochloride method. The assay, which was sensitive to 0.02-0.5 micro g of LDL(2), had an inter-assay coefficient of variation of 4.5%. This assay was successfully used to measure apoB in the whole serum and low density lipoproteins of control monkeys maintained on a standard Purina monkey chow (PMC) diet and of three groups of monkeys fed atherogenic diets: an "average American diet," a 25% peanut oil and 2% cholesterol-supplemented PMC diet, and a 25% coconut oil and 2% cholesterol-supplemented PMC diet. The control monkeys (n = 13) had a serum cholesterol of 146 +/- 28 mg/dl and an apoB of 50 +/- 18 mg/dl. In the monkeys maintained on the atherogenic diets the serum apoB was elevated: 103 +/- 28 mg/dl (American), 102 +/- 35 mg/dl (peanut oil), and 312 +/- 88 mg/dl (coconut oil). The values for serum total cholesterol were 333 +/- 65 mg/dl (American), 606 +/- 212 mg/dl (peanut oil), and 864 +/- 233 mg/dl (coconut oil) and were elevated relative to controls (P < 0.001). For each of the diets, total serum cholesterol correlated with serum apoB (P < 0.001). The slopes of the regression lines of serum apoB vs. cholesterol for the monkeys on the PMC, American, and coconut oil diets were similar (m = 0.531, 0.401, and 0.359, respectively), but differed from that of monkeys on the peanut oil diet (m = 0.121). The immunoreactivities of rhesus and human LDL were compared using specific antisera raised against these antigens. In homologous assay systems, monkey and human LDL exhibited unique immunological determinants. The same results were obtained with the delipidated preparations of the two LDLs using antisera raised

  7. Endothelium-dependent vasorelaxation in the aorta of transgenic mice expressing human apolipoprotein(a) or lipoprotein(a).

    PubMed

    Rubanyi, G M; Freay, A D; Lawn, R M

    2000-01-01

    Elevated plasma level of lipoprotein(a) (Lp(a)) is a well established risk factor for premature atherosclerosis and coronary artery disease. Recent studies showed impaired endothelium-dependent vasodilatation in humans with elevated plasma Lp(a). However, these human studies could not determine whether (1) elevated Lp(a) levels alone are the cause of endothelial dysfunction (these patients had multiple risk factors), and (2) native or oxidatively modified Lp(a) contributes to endothelial dysfunction (no measurements of native/oxidized Lp(a) ratio was reported in humans). In order to test whether apo(a) (an essential component of Lp(a) which is required for binding to endothelial cells) and native Lp(a) cause endothelial dysfunction, in the present study we tested endothelium-dependent vasorelaxation in aortic rings isolated from control and transgenic male mice either expressing the human apo(a) gene (TgA) or both the human apo(a) and human apo B100 genes (TgL). The TgA mice had plasma apo(a) levels of 8.8 +/- 1.2 mg/dl (n=6) and the double transgenic TgL mice had plasma Lp(a) levels of 15.3 +/- 1.4 mg/dl (n=8). Isolated aortic rings with and without endothelium were mounted in organ chambers and contracted with U46619 (10(-8) M) in the presence of ibuprofen (10(-5) M). Acetylcholine caused concentration-dependent (10(-9)-10(-5) M) relaxation, which could be prevented by endothelium removal and by NG-L-nitro-arginine (10(-4) M). Basal and acetylcholine-stimulated endothelium-dependent relaxation and endothelium-independent relaxation to nitroglycerin (10(-6) M) were not significantly different in aortic rings isolated from control and TgA or TgL mice. Twenty-four hour incubation of aortic rings isolated from control mice with recombinant human apo(a) or native Lp(a) (up to 300 microg/ml) caused no impairment of endothelium-dependent relaxations. In contrast, incubation with oxidized Lp(a) (50 microg/ml) or oxidized LDL (250 microg/ml) caused significant suppression

  8. IL-6 blockade by monoclonal antibodies inhibits apolipoprotein (a) expression and lipoprotein (a) synthesis in humans[S

    PubMed Central

    Müller, Nike; Schulte, Dominik M.; Türk, Kathrin; Freitag-Wolf, Sandra; Hampe, Jochen; Zeuner, Rainald; Schröder, Johann O.; Gouni-Berthold, Ioanna; Berthold, Heiner K.; Krone, Wilhelm; Rose-John, Stefan; Schreiber, Stefan; Laudes, Matthias

    2015-01-01

    Lipoprotein (a) [Lp(a)] is a highly atherogenic lipid particle. Although earlier reports suggested that Lp(a) levels are mostly determined by genetic factors, several recent studies have revealed that Lp(a) induction is also caused by chronic inflammation. Therefore, we aimed to examine whether cytokine blockade by monoclonal antibodies may inhibit Lp(a) metabolism. We found that interleukin 6 (IL-6) blockade by tocilizumab (TCZ) reduced Lp(a) while TNF-α-inhibition by adalimumab in humans had no effect. The specificity of IL-6 in regulating Lp(a) was further demonstrated by serological measurements of human subjects (n = 1,153) revealing that Lp(a) levels are increased in individuals with elevated serum IL-6. Transcriptomic analysis of human liver biopsies (n = 57) revealed typical IL-6 response genes being correlated with the LPA gene expression in vivo. On a molecular level, we found that TCZ inhibited IL-6-induced LPA mRNA and protein expression in human hepatocytes. Furthermore, examination of IL-6-responsive signal transducer and activator of transcription 3 binding sites within the LPA promoter by reporter gene assays, promoter deletion experiments, and electrophoretic mobility shift assay analysis showed that the Lp(a)-lowering effect of TCZ is specifically mediated via a responsive element at −46 to −40. Therefore, IL-6 blockade might be a potential therapeutic option to treat elevated Lp(a) serum concentrations in humans and might be a noninvasive alternative to lipid apheresis in the future. PMID:25713100

  9. Amyloid Triangles, Squares, and Loops of Apolipoprotein C-III

    PubMed Central

    2015-01-01

    While a significant component of atherosclerotic plaques has been characterized as amyloid, the specific proteins remain to be fully identified. Probable amyloidogenic proteins are apolipoproteins (Apos), which are vital for the formation and function of lipoproteins. ApoCIII is an abundant protein implicated in atherosclerosis, and we show it forms a ribbonlike looped amyloid, strikingly similar to that previously reported for ApoAI and ApoCII. Triangles and squares with a width of ∼50 nm were also observed, which may be a novel form of amyloid or related to previously reported amyloid rings. PMID:24804986

  10. Cerebral Apolipoprotein-D Is Hypoglycosylated Compared to Peripheral Tissues and Is Variably Expressed in Mouse and Human Brain Regions.

    PubMed

    Li, Hongyun; Ruberu, Kalani; Karl, Tim; Garner, Brett

    2016-01-01

    Recent studies have shown that cerebral apoD levels increase with age and in Alzheimer's disease (AD). In addition, loss of cerebral apoD in the mouse increases sensitivity to lipid peroxidation and accelerates AD pathology. Very little data are available, however, regarding the expression of apoD protein levels in different brain regions. This is important as both brain lipid peroxidation and neurodegeneration occur in a region-specific manner. Here we addressed this using western blotting of seven different regions (olfactory bulb, hippocampus, frontal cortex, striatum, cerebellum, thalamus and brain stem) of the mouse brain. Our data indicate that compared to most brain regions, the hippocampus is deficient in apoD. In comparison to other major organs and tissues (liver, spleen, kidney, adrenal gland, heart and skeletal muscle), brain apoD was approximately 10-fold higher (corrected for total protein levels). Our analysis also revealed that brain apoD was present at a lower apparent molecular weight than tissue and plasma apoD. Utilising peptide N-glycosidase-F and neuraminidase to remove N-glycans and sialic acids, respectively, we found that N-glycan composition (but not sialylation alone) were responsible for this reduction in molecular weight. We extended the studies to an analysis of human brain regions (hippocampus, frontal cortex, temporal cortex and cerebellum) where we found that the hippocampus had the lowest levels of apoD. We also confirmed that human brain apoD was present at a lower molecular weight than in plasma. In conclusion, we demonstrate apoD protein levels are variable across different brain regions, that apoD levels are much higher in the brain compared to other tissues and organs, and that cerebral apoD has a lower molecular weight than peripheral apoD; a phenomenon that is due to the N-glycan content of the protein. PMID:26829325

  11. Cerebral Apolipoprotein-D Is Hypoglycosylated Compared to Peripheral Tissues and Is Variably Expressed in Mouse and Human Brain Regions

    PubMed Central

    Li, Hongyun; Ruberu, Kalani; Karl, Tim; Garner, Brett

    2016-01-01

    Recent studies have shown that cerebral apoD levels increase with age and in Alzheimer’s disease (AD). In addition, loss of cerebral apoD in the mouse increases sensitivity to lipid peroxidation and accelerates AD pathology. Very little data are available, however, regarding the expression of apoD protein levels in different brain regions. This is important as both brain lipid peroxidation and neurodegeneration occur in a region-specific manner. Here we addressed this using western blotting of seven different regions (olfactory bulb, hippocampus, frontal cortex, striatum, cerebellum, thalamus and brain stem) of the mouse brain. Our data indicate that compared to most brain regions, the hippocampus is deficient in apoD. In comparison to other major organs and tissues (liver, spleen, kidney, adrenal gland, heart and skeletal muscle), brain apoD was approximately 10-fold higher (corrected for total protein levels). Our analysis also revealed that brain apoD was present at a lower apparent molecular weight than tissue and plasma apoD. Utilising peptide N-glycosidase-F and neuraminidase to remove N-glycans and sialic acids, respectively, we found that N-glycan composition (but not sialylation alone) were responsible for this reduction in molecular weight. We extended the studies to an analysis of human brain regions (hippocampus, frontal cortex, temporal cortex and cerebellum) where we found that the hippocampus had the lowest levels of apoD. We also confirmed that human brain apoD was present at a lower molecular weight than in plasma. In conclusion, we demonstrate apoD protein levels are variable across different brain regions, that apoD levels are much higher in the brain compared to other tissues and organs, and that cerebral apoD has a lower molecular weight than peripheral apoD; a phenomenon that is due to the N-glycan content of the protein. PMID:26829325

  12. Artificial intelligence. Fears of an AI pioneer.

    PubMed

    Russell, Stuart; Bohannon, John

    2015-07-17

    From the enraged robots in the 1920 play R.U.R. to the homicidal computer H.A.L. in 2001: A Space Odyssey, science fiction writers have embraced the dark side of artificial intelligence (AI) ever since the concept entered our collective imagination. Sluggish progress in AI research, especially during the “AI winter” of the 1970s and 1980s, made such worries seem far-fetched. But recent breakthroughs in machine learning and vast improvements in computational power have brought a flood of research funding— and fresh concerns about where AI may lead us. One researcher now speaking up is Stuart Russell, a computer scientist at the University of California, Berkeley, who with Peter Norvig, director of research at Google, wrote the premier AI textbook, Artificial Intelligence: A Modern Approach, now in its third edition. Last year, Russell joined the Centre for the Study of Existential Risk at Cambridge University in the United Kingdom as an AI expert focusing on “risks that could lead to human extinction.” Among his chief concerns, which he aired at an April meeting in Geneva, Switzerland, run by the United Nations, is the danger of putting military drones and weaponry under the full control of AI systems. This interview has been edited for clarity and brevity. PMID:26185241

  13. AI aerospace components

    SciTech Connect

    Heindel, T.A.; Murphy, T.B.; Rasmussen, A.N.; Mcfarland, R.Z.; Montgomery, R.E.; Pohle, G.E.; Heard, A.E.; Atkinson, D.J.; Wedlake, W.E.; Anderson, J.M. Mitre Corp., Houston, TX Unisys Corp., Houston, TX Rockwell International Corp., El Segundo, CA NASA, Kennedy Space Center, Cocoa Beach, FL JPL, Pasadena, CA Lockheed Missiles and Space Co., Inc., Austin, TX McDonnell Douglas Electronic Systems Co., McLean, VA )

    1991-10-01

    An evaluation is made of the application of novel, AI-capabilities-related technologies to aerospace systems. Attention is given to expert-system shells for Space Shuttle Orbiter mission control, manpower and processing cost reductions at the NASA Kennedy Space Center's 'firing rooms' for liftoff monitoring, the automation of planetary exploration systems such as semiautonomous mobile robots, and AI for battlefield staff-related functions.

  14. The Structure of Human Apolipoprotein A-IV as Revealed by Stable Isotope-assisted Cross-linking, Molecular Dynamics, and Small Angle X-ray Scattering*

    PubMed Central

    Walker, Ryan G.; Deng, Xiaodi; Melchior, John T.; Morris, Jamie; Tso, Patrick; Jones, Martin K.; Segrest, Jere P.; Thompson, Thomas B.; Davidson, W. Sean

    2014-01-01

    Apolipoprotein (apo)A-IV plays important roles in dietary lipid and glucose metabolism, and knowledge of its structure is required to fully understand the molecular basis of these functions. However, typical of the entire class of exchangeable apolipoproteins, its dynamic nature and affinity for lipid has posed challenges to traditional high resolution structural approaches. We previously reported an x-ray crystal structure of a dimeric truncation mutant of apoA-IV, which showed a unique helix-swapping molecular interface. Unfortunately, the structures of the N and C termini that are important for lipid binding were not visualized. To build a more complete model, we used chemical cross-linking to derive distance constraints across the full-length protein. The approach was enhanced with stable isotope labeling to overcome ambiguities in determining molecular span of the cross-links given the remarkable similarities in the monomeric and dimeric apoA-IV structures. Using 51 distance constraints, we created a starting model for full-length monomeric apoA-IV and then subjected it to two modeling approaches: (i) molecular dynamics simulations and (ii) fitting to small angle x-ray scattering data. This resulted in the most detailed models yet for lipid-free monomeric or dimeric apoA-IV. Importantly, these models were of sufficient detail to direct the experimental identification of new functional residues that participate in a “clasp” mechanism to modulate apoA-IV lipid affinity. The isotope-assisted cross-linking approach should prove useful for further study of this family of apolipoproteins in both the lipid-free and -bound states. PMID:24425874

  15. Plasma lipoproteins and renal apolipoproteins in rats with chronic adriamycin nephrosis.

    PubMed

    Joles, J A; van Tol, A; Jansen, E H; Koomans, H A; Rabelink, T J; Grond, J; van Goor, H

    1993-01-01

    The relation between plasma lipoprotein composition and renal apolipoprotein deposition was studied in nephrotic rats in which stable renal function had been monitored for 7 months after a single low dose of adriamycin (ADR, 3 mg/kg). Proteinuria was observed 3 weeks after ADR and increased progressively up to about 0.5 g/day (versus 0.07 g/day in controls; P < 0.001), while the creatinine clearance remained stable at about 80% of control values. Hypercholesterolaemia was observed 6 weeks after ADR, and increased progressively up to 7.0 +/- 1.0 mmol/l (versus 2.3 +/- 0.1 mmol/l in controls; P < 0.001). Cholesterol was primarily located in LDL2 and HDL2 lipoproteins. Plasma apolipoprotein (apo) A-I increased by more than 400% in the nephrotic rats (P < 0.001). Apo B and apo E increased by about 60% (P < 0.01), whereas apo A-IV remained unchanged. Focal sclerotic lesions in glomeruli had an incidence of 50 +/- 10% in ADR rats versus 2 +/- 1% in controls (P < 0.001). Immunohistochemistry revealed apo A-I and apo A-IV in the visceral epithelium. Apo E immunoreactivity and lipid deposits were observed in focal glomerular sclerotic lesions of ADR rats. Neither apolipoproteins nor lipids were detected in glomeruli of controls. Proximal tubular localization of apolipoproteins was extensive for apo A-I, apo A-IV and apo E, but no differences were observed in tubular deposition of apolipoproteins between ADR and control rats.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8255516

  16. Effect of intestinal chylomicron secretory blockade on apolipoprotein synthesis in the newborn piglet.

    PubMed Central

    Black, D D

    1992-01-01

    Pluronic L-81 is a hydrophobic surfactant which blocks intestinal chylomicron secretion at the pre-Golgi level without affecting triacylglycerol uptake and re-esterification. To study the effects of such blockade on apolipoprotein synthesis, newborn female piglets received 24 h intraduodenal infusions of low-triacylglycerol, or high-triacylglycerol with or without Pluronic L-81, diets, followed by determination of apolipoprotein (apo) B-48, A-I and A-IV synthesis and content and apo B and A-IV mRNA levels in the small intestine. Jejunal apo B-48 content, synthesis and mRNA levels were down-regulated below basal levels by the addition of Pluronic to the high-triacylglycerol infusion. The normal increase in apo A-I synthesis induced by triacylglycerol absorption was ablated in both jejunum and ileum, even though the expected increase in apo A-I content in jejunum still occurred. Although attenuated, the expected increase in jejunal apo A-IV synthesis and mRNA levels with triacylglycerol absorption was still present with Pluronic treatment. These results suggest very different mechanisms of cellular regulation and trafficking for the various apolipoproteins incorporated into nascent intestinal chylomicrons. Apo B may be specifically down-regulated by the chylomicron secretory blockade induced by Pluronic L-81. PMID:1567381

  17. Increased production of apolipoprotein B and its lipoproteins by oleic acid in Caco-2 cells.

    PubMed

    Dashti, N; Smith, E A; Alaupovic, P

    1990-01-01

    The production of lipids, apolipoproteins (apo), and lipoproteins induced by oleic acid has been examined in Caco-2 cells. The rates of accumulation in the control medium of 15-day-old Caco-2 cells of triglycerides, unesterified cholesterol, and cholesteryl esters were 102 +/- 8, 73 +/- 5, and 11 +/- 1 ng/mg cell protein/h, respectively; the accumulation rates for apolipoproteins A-I, B, C-III, and E were 111 +/- 9, 53 +/- 4, 13 +/- 1, and 63 +/- 4 ng/mg cell protein/h, respectively. Whereas apolipoproteins A-IV and C-II were detected by immunoblotting, apoA-II was absent in most culture media. In contrast to an early production of apolipoproteins A-I and E occurring 2 days after plating, the apoB expression appeared to be differentiation-dependent and was not measurable in the medium until the sixth day post-confluency. In the control medium, very low density lipoproteins (VLDL), low density lipoproteins (LDL), high density lipoproteins (HDL), and lipid-poor very high density lipoproteins (VHDL) accounted for 12%, 46%, 18%, and 24% of the total lipid and apolipoprotein contents, respectively. The triglyceride-rich VLDL contained mainly apoE (75%) and apoB (23%), while the protein moiety of LDL was composed of apoB (59%), apoE (20%), apoA-I (15%), and apoC-III (6%). The cholesterol-rich HDL contained mainly apoA-I (69%) and apoE (27%). In the control medium, major portions of apolipoproteins B and C-III (93-97%) were present in LDL, whereas the main parts of apoA-I (92%) and apoE (76%) were associated with HDL and VHDL. Oleate increased the production of triglycerides 10-fold, cholesteryl esters 7-fold, and apoB 2- to 4-fold. There was also a moderate increase (39%) in the production of apoC-III but no significant changes in those of apolipoproteins A-I and E. These increases were reflected mainly in a 55-fold elevation in the concentration of VLDL, and a 2-fold increase in the level of LDL; there were no significant changes in HDL and VHDL. VLDL contained the

  18. Synthesis of HDL apolipoproteins by rat hepatocytes

    SciTech Connect

    Hussain, M.M.; Kelley, M.; Zannis, V.I.

    1986-05-01

    The authors have used 2D-PAGE to study the synthesis, intracellular modification, and secretion of rat HDL apolipoproteins by primary cultures of rat hepatocytes. ApoA-IV, apoA-II and apoE synthesized after a 10 min pulse with /sup 35/S-methionine coincided on 2D-gels with their corresponding plasma forms and they were not modified further intracellularly or following secretion. A fraction (< 10%) of apoE was modified intracellularly to minor isoprotein forms that were insensitive to neuraminidase treatment. These later forms also constituted a minor component of the secreted and plasma rat apoE. The intracellular and newly secreted apoA-I differed from its plasma counterpart by -1 charge as described previously. The intracellular forms of rat apoA-I, apoA-IV and unmodified apoE differed from the products of cell free translation of rat liver mRNA by +1 charge. Their findings (a) establish the charge relationship between nascent and plasma rat apolipoproteins, (b) indicate that rat apoA-I, apoA-II and apoA-IV are not modified intracellularly, (c) suggest that there is a difference in the post-translational modification patterns between the rat and human hepatic apoE.

  19. Apolipoprotein A-V interaction with members of the low density lipoprotein receptor gene family.

    PubMed

    Nilsson, Stefan K; Lookene, Aivar; Beckstead, Jennifer A; Gliemann, Jørgen; Ryan, Robert O; Olivecrona, Gunilla

    2007-03-27

    Apolipoprotein A-V is a potent modulator of plasma triacylglycerol levels. To investigate the molecular basis for this phenomenon we explored the ability of apolipoprotein A-V, in most experiments complexed to disks of dimyristoylphosphatidylcholine, to interact with two members of the low density lipoprotein receptor family, the low density lipoprotein receptor-related protein and the mosaic type-1 receptor, SorLA. Experiments using surface plasmon resonance showed specific binding of both free and lipid-bound apolipoprotein A-V to both receptors. The binding was calcium dependent and was inhibited by the receptor associated protein, a known ligand for members of the low density lipoprotein receptor family. Preincubation with heparin decreased the receptor binding of apolipoprotein A-V, indicating that overlap exists between the recognition sites for these receptors and for heparin. A double mutant, apolipoprotein A-V (Arg210Glu/Lys211Gln), showed decreased binding to heparin and decreased ability to bind the low density lipoprotein receptor-related protein. Association of apolipoprotein A-V with the low density lipoprotein receptor-related protein or SorLA resulted in enhanced binding of human chylomicrons to receptor-covered sensor chips. Our results indicate that apolipoprotein A-V may influence plasma lipid homeostasis by enhancing receptor-mediated endocytosis of triacylglycerol-rich lipoproteins. PMID:17326667

  20. AI in manufacturing

    NASA Technical Reports Server (NTRS)

    Gross, John E.; Minato, Rick; Smith, David M.; Loftin, R. B.; Savely, Robert T.

    1991-01-01

    AI techniques are shown to have been useful in such aerospace industry tasks as vehicle configuration layouts, process planning, tool design, numerically-controlled programming of tools, production scheduling, and equipment testing and diagnosis. Accounts are given of illustrative experiences at the production facilities of three major aerospace defense contractors. Also discussed is NASA's autonomous Intelligent Computer-Aided Training System, for such ambitious manned programs as Space Station Freedom, which employs five different modules to constitute its job-independent training architecture.

  1. AI in manufacturing

    NASA Astrophysics Data System (ADS)

    Gross, John E.; Minato, Rick; Smith, David M.; Loftin, R. B.; Savely, Robert T.

    1991-10-01

    AI techniques are shown to have been useful in such aerospace industry tasks as vehicle configuration layouts, process planning, tool design, numerically-controlled programming of tools, production scheduling, and equipment testing and diagnosis. Accounts are given of illustrative experiences at the production facilities of three major aerospace defense contractors. Also discussed is NASA's autonomous Intelligent Computer-Aided Training System, for such ambitious manned programs as Space Station Freedom, which employs five different modules to constitute its job-independent training architecture.

  2. Apolipoprotein E isoform-dependent microglia migration

    PubMed Central

    Cudaback, Eiron; Li, Xianwu; Montine, Kathleen S.; Montine, Thomas J.; Keene, C. Dirk

    2011-01-01

    Complement component C5a and ATP are potent effectors of microglial movement and are increased in diverse neurodegenerative diseases and at sites of injury. Apolipoprotein E (apoE) influences microglial function, and different human apoE isoforms confer variable risk for development of neurodegenerative disorders, especially Alzheimer's disease. The purpose of this investigation was to test the hypothesis that mouse apoE and human apoE isoforms influence microglial migration. Using primary wild-type and apoE-deficient microglia, we show that C5a- and ATP-stimulated chemotaxis are largely apoE-dependent processes with different molecular bases. Although the C5a-dependent chemotaxis of wild-type microglia was completely blocked by receptor-associated protein (RAP), suggesting apoE receptor involvement, ATP-stimulated migration was unaffected by RAP but was associated with differential ERK phosphorylation. Studies using primary microglia derived from targeted replacement mice “humanized” for the coding exons (protein isoform) of human ε2 (apoE2), ε3 (apoE3), or ε4 (apoE4) allele of APOE revealed that primary mouse microglia expressing apoE4 or apoE2 exhibited significantly reduced C5a- and ATP-stimulated migration compared with microglia expressing human apoE3. This study, for the first time, demonstrates apoE dependence and apoE isoform-specific modulation of microglial migration in response to distinct chemotactic stimuli commonly associated with neurodegenerative disease.—Cudaback, E., Li, X., Montine, K. S., Montine, T. J., Keene, C. D. Apolipoprotein E isoform-dependent microglia migration. PMID:21385991

  3. Proteomic profiling of human plasma identifies apolipoprotein E as being associated with smoking and a marker for squamous metaplasia of the lung.

    PubMed

    Rice, Shawn J; Liu, Xin; Miller, Bruce; Joshi, Monika; Zhu, Junjia; Caruso, Carla; Gilbert, Chris; Toth, Jennifer; Reed, Michael; Rassaei, Negar; Das, Arun; Barochia, Amit; El-Bayoumy, Karam; Belani, Chandra P

    2015-09-01

    Biomarkers to identify subjects at high-risk for developing lung cancer will revolutionize the disease outlook. Most biomarker studies have focused on patients already diagnosed with lung cancer and in most cases the disease is often advanced and incurable. The objective of this study was to use proteomics to identify a plasma biomarker for early detection of lung lesions that may subsequently be the harbinger for cancer. Plasma samples were obtained from subjects without lung cancer grouped as never, current, or ex-smokers. An iTRAQ-based proteomic analysis was performed on these pooled plasma samples. We identified 31 proteins differentially abundant in current smokers or ex-smokers relative to never smokers. Western blot and ELISA analyses confirmed the iTRAQ results that demonstrated an increase of apolipoprotein E (APOE) in current smokers as compared to both never and ex-smokers. There was a strong and significant correlation of the plasma APOE levels with development of premalignant squamous metaplasia. Additionally, we also showed that higher tissue levels of APOE are seen with squamous metaplasia, supporting a direct relationship. Our analysis reveals that elevated plasma APOE is associated with smoking, and APOE is a novel predictive protein biomarker for early morphological changes of squamous metaplasia in the lung. PMID:26058877

  4. Apolipoprotein A1 as a novel anti-implantation biomarker in polycystic ovary syndrome: A case-control study

    PubMed Central

    Amjadi, Fatemehsadat; Aflatoonian, Reza; Javanmard, Shaghayegh Haghjoo; Saifi, Bita; Ashrafi, Mahnaz; Mehdizadeh, Mehdi

    2015-01-01

    Background: Women with polycystic ovary syndrome have lower pregnancy rates, possibly due to the decreased uterine receptivity. Successful implantation depends on protein networks that are essential for cross-talk between the embryo and endometrium. Apolipoprotein A1 has been proposed as a putative anti-implantation factor. In this study, we evaluated apolipoprotein A1 expression in human endometrial tissues. Materials and Methods: Endometrial apolipoprotein A1 messenger RNA (mRNA) and protein expression were investigated using quantitative real-time polymerase chain reaction (PCR) and Western blot. The distribution of apolipoprotein A1 was also detected by immunostaining. Samples were obtained from 10 patients with polycystic ovary syndrome and 15 healthy fertile women in the proliferative (on day 2 or day 3 before ovulation, n = 7) and secretory (on days 3-5 after ovulation, n = 8) phases. Results: Endometrial apolipoprotein A1 expression was upregulated in patients with polycystic ovary syndrome compared to normal subjects. However, apolipoprotein A1 expression in the proliferative phase was significantly higher than in the luteal phase (P value < 0.05). Conclusion: It seems that differentially expressed apolipoprotein A1 negatively affects endometrial receptivity in patients with polycystic ovary syndrome. The results showed that apolipoprotein A1 level significantly changes in the human endometrium during the menstrual cycle with minimum expression in the secretory phase, coincident with the receptive phase (window of implantation). Further studies are required to clarify the clinical application of this protein. PMID:26941806

  5. Pro-apoptotic activities of polyphenolics from açai (Euterpe oleracea Martius) in human SW-480 colon cancer cells.

    PubMed

    Dias, Manoela Maciel dos Santos; Noratto, Giuliana; Martino, Hercia Stampini Duarte; Arbizu, Shirley; Peluzio, Maria do Carmo Gouveia; Talcott, Stephen; Ramos, Afonso Mota; Mertens-Talcott, Susanne U

    2014-01-01

    This study aimed to evaluate the cell growth inhibition activity of açai (Euterpe oleracea Mart.) polyphenolic extract against colon cancer HT-29 and SW-480 cells and the nonmalignant CCD-18Co colon fibroblast cells. Results showed that açai polyphenolic extract (5-20 mg/L) inhibited preferentially the growth of SW-480 cells with no toxicity in CCD-18Co cells, and this was accompanied by reduction of H2O2-induced reactive oxygen species (ROS) generation. The mechanisms involved in SW-480 cell growth-inhibition by açai polyphenolic extract included the downregulation of NF-κB proinflammatory transcription factor and the nuclear factor-kappa B targets intracellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1). Furthermore, prooncogenic specificity proteins (Sp) were downregulated as well as Sp-targets Bcl-2, vascular endothelial growth factor, and survivin. This was accompanied by activation of mitochondrial proapoptotic pathway involving increase of cytochrome c, cleavage of caspase-3, and decrease of PARP-1. Results strongly suggest that açai polyphenolic extract has antiinflammatory and cytotoxic activities in colon cancer cells and can be effective as natural colon cancer chemopreventive agents. PMID:25329001

  6. Apolipoprotein E genotype in schizophrenia

    SciTech Connect

    Joober, R.; Lal, S.; Bloom, D.; Benkelfat, C.

    1996-04-09

    We investigated the association between schizophrenia and the allelic polymorphism in the apolipoprotein E (Apo E) gene in 51 schizophrenic patients and 35 controls. The Apo E4 allele was equally represented in the schizophrenic group (16%) and the control group (20%) suggesting no association between schizophrenia and the Apo E4 allele. The apolipoprotein E (Apo E) is a polymorphic (E2, E3, and E4) lipoprotein involved in the transmembrane transport of cholesterol and is thought to play an important role in neuronal growth and in the central nervous system response to injury, particularly in the hippocampal region. Recent findings strongly suggest that the Apo E4 allele is associated with cognitive deficits in normal and pathological aging, e.g., Alzheimer`s disease. 5 refs., 1 tab.

  7. Regulation of endogenous apolipoprotein E secretion by macrophages.

    PubMed

    Kockx, Maaike; Jessup, Wendy; Kritharides, Leonard

    2008-06-01

    Apolipoprotein E has critical roles in the protection against atherosclerosis and is understood to follow the classical constitutive secretion pathway. Recent studies have indicated that the secretion of apoE from macrophages is a regulated process of unexpected complexity. Cholesterol acceptors such as apolipoprotein A-I, high density lipoprotein, and phospholipid vesicles can stimulate apoE secretion. The ATP binding cassette transporter ABCA1 is involved in basal apoE secretion and in lipidating apoE-containing particles secreted by macrophages. However, the stimulation of apoE secretion by apoA-I is ABCA1-independent, indicating the existence of both ABCA1-dependent and -independent pathways of apoE secretion. The release of apoE under basal conditions is also regulated, requiring intact protein kinase A activity, intracellular calcium, and an intact microtubular network. Mathematical modeling of apoE turnover indicates that whereas some pools of apoE are committed to either secretion or degradation, other pools can be diverted from degradation toward secretion. Targeted inhibition or stimulation of specific apoE trafficking pathways will provide unique opportunities to regulate the biology of this important molecule. PMID:18388328

  8. Plasma lipid, lipoprotein and apolipoprotein profiles in Nigerian university athletes and non-athletes.

    PubMed Central

    Oyelola, O O; Rufai, M A

    1993-01-01

    The fasting plasma lipid, lipoprotein and apolipoprotein profiles were determined in 14 healthy Nigerian male athletes and controls matched for sex and anthropometric parameters. The mean levels of total cholesterol (P < 0.05), low-density lipoprotein (LDL) cholesterol, apolipoprotein (apo) AII and E were significantly lower (P < 0.01) in the athletes than in the controls. However, there were no statistically significant differences (P > 0.05) between the mean values of the plasma triglycerides, high-density lipoprotein (HDL), very low-density lipoprotein (VLDL) cholesterol, apo AI, B, Lp(a), LpA1 and CIII:NonB respectively for the athletes and controls. A priori, the potential effect on cardiovascular disease (CVD) risk was also compared using three predictor ratios - total cholesterol: HDL cholesterol (TC:HDL), LDL cholesterol: HDL cholesterol and apo B:AI. The mean of the three ratios was lower in the athletes than in the controls; however, the differences were not statistically significant (P > 0.05). Based on our data, exercise appears to decrease the TC:HDL ratio in the athletes by lowering LDL-cholesterol, while the HDL-cholesterol is unaffected. We conclude that physical activity has salutary effects on the lipid, lipoprotein and apolipoprotein profiles of healthy Nigerian men. PMID:8130968

  9. Interactions between Hepatitis C Virus and the Human Apolipoprotein H Acute Phase Protein: A Tool for a Sensitive Detection of the Virus

    PubMed Central

    Dubois, Grégor; Kaiser, Marco; Lucarz, Estelle; Gobby, Delphine; Bray, Dorothy; Ellerbrok, Heinz; Zarski, Jean Pierre; Veas, Francisco

    2015-01-01

    The Hepatitis C virus (HCV) infection exhibits a high global prevalence frequently associated with hepatocellular carcinoma, taking years to develop. Despite the standardization of highly sensitive HCV quantitative RT-PCR (qRT-PCR) detection methods, false-negative diagnoses may be generated with current methods, mainly due to the presence of PCR inhibitors and/or low viral loads in the patient’s sample. These false-negative diagnoses impact both public health systems, in developing countries, and an in lesser extent, in developed countries, including both the risk of virus transmission during organ transplantation and/or blood transfusion and the quality of the antiviral treatment monitoring. To adopt an appropriate therapeutic strategy to improve the patient’s prognosis, it is urgent to increase the HCV detection sensitivity. Based upon previous studies on HBV, we worked on the capacity of the scavenger acute phase protein, Apolipoprotein H (ApoH) to interact with HCV. Using different approaches, including immunoassays, antibody-inhibition, oxidation, ultracentrifugation, electron microscopy and RT-PCR analyses, we demonstrated specific interactions between HCV particles and ApoH. Moreover, when using a two-step HCV detection process, including capture of HCV by ApoH-coated nanomagnetic beads and a home-made real-time HCV-RT-PCR, we confirmed the presence of HCV for all samples from a clinical collection of HCV-seropositive patients exhibiting an RT-PCR COBAS® TaqMan® HCV Test, v2.0 (COBAS)-positive result. In contrast, for HCV-seropositive patients with either low HCV-load as determined with COBAS or exhibiting HCV-negative COBAS results, the addition of the two-step ApoH-HCV-capture and HCV-detection process was able to increase the sensitivity of HCV detection or more interestingly, detect in a genotype sequence-independent manner, a high-proportion (44%) of HCV/RNA-positive among the COBAS HCV-negative patients. Thus, the immune interaction between Apo

  10. Identification of the human ApoAV gene as a novel ROR{alpha} target gene

    SciTech Connect

    Lind, Ulrika; Nilsson, Tina; McPheat, Jane; Stroemstedt, Per-Erik; Bamberg, Krister; Balendran, Clare; Kang, Daiwu . E-mail: Daiwu.Kang@astrazeneca.com

    2005-04-29

    Retinoic acid receptor-related orphan receptor-{alpha} (ROR{alpha}) (NR1F1) is an orphan nuclear receptor with a potential role in metabolism. Previous studies have shown that ROR{alpha} regulates transcription of the murine Apolipoprotein AI gene and human Apolipoprotein CIII genes. In the present study, we present evidence that ROR{alpha} also induces transcription of the human Apolipoprotein AV gene, a recently identified apolipoprotein associated with triglyceride levels. Adenovirus-mediated overexpression of ROR{alpha} increased the endogenous expression of ApoAV in HepG2 cells and ROR{alpha} also enhanced the activity of an ApoAV promoter construct in transiently transfected HepG2 cells. Deletion and mutation studies identified three AGGTCA motifs in the ApoAV promoter that mediate ROR{alpha} transactivation, one of which overlaps with a previously identified binding site for PPAR{alpha}. Together, these results suggest a novel mechanism whereby ROR{alpha} modulates lipid metabolism and implies ROR{alpha} as a potential target for the treatment of dyslipidemia and atherosclerosis.

  11. Cloning of a cDNA encoding a putative human very low density lipoprotein/Apolipoprotein E receptor and assignment of the gene to chromosome 9pter-p23[sup 6

    SciTech Connect

    Gafvels, M.E.; Strauss, J.F. III ); Caird, M.; Patterson, D. ); Britt, D.; Jackson, C.L. )

    1993-11-01

    The authors report the cloning of a 3656-bp cDNA encoding a putative human very low density lipoprotein (VLDL)/apolipoprotein E (ApoE) receptor. The gene encoding this protein was mapped to chromosome 9pter-p23. Northern analysis of human RNA identified cognate mRNAs of 6.0 and 3.8 kb with most abundant expression in heart and skeletal muscle, followed by kidney, placenta, pancreas, and brain. The pattern of expression generally paralleled that of lipoprotein lipase mRNA but differed from that of the low density lipoprotein (LDL) receptor and the low density lipoprotein receptor-related protein/[alpha][sub 2]-macroglobulin receptor (LRP), which are members of the same gene family. VLDL/ApoE receptor message was not detected in liver, whereas mRNAs for both LDL receptor and LRP were found in hepatic tissue. In mouse 3T3-L1 cells, VLDL/ApoE receptor mRNA was induced during the transformation of the cells into adipocytes. Expression was also detected in human choriocarcinoma cells, suggesting that at least part of the expression observed in placenta may be in trophoblasts, cells which would be exposed to maternal blood. Expression in brain may be related to high levels of ApoE expression in that organ, an observation of potential relevance to the recently hypothesized role for ApoE in late onset Alzheimer disease. The results suggest that the putative VLDL/ApoE receptor could play a role in the uptake of triglyceride-rich lipoprotein particles by specific organs including striated and cardiac muscle and adipose tissue and in the transport of maternal lipids across the placenta. The findings presented here, together with recent observations from other laboratories, bring up the possibility that a single gene, the VLDL/ApoE receptor, may play a role in the pathogenesis of certain forms of atherosclerosis, Alzheimer disease, and obesity.

  12. Homo- and hetero-complexes of exchangeable apolipoproteins in solution and in lipid-bound form

    NASA Astrophysics Data System (ADS)

    Dergunov, Alexander D.; Vorotnikova, Yulia Y.; Visvikis, Sophie; Siest, Gerard

    2003-03-01

    The self-association state of human plasma apolipoprotein E (apoE) in solution and in complexes with dimyristoylphosphatidylcholine (DMPC) varying in stoichiometry was studied in sub-micromolar concentration range by gel filtration, fluorescence anisotropy, fluorescence quenching and energy transfer measurements with apolipoprotein labeled with lysine-specific fluorescent dyes. Together, these results confirm the equilibrium scheme for various apoE structures in solution: oligomer (in aged preparations) ⇆ 'closed' tetramer ⇆ 'open' tetramer ('molten globule' state) ⇆ native or partially denatured monomer ⇆ fully denatured monomer. Within DMPC:apoE discoidal complex (125:1) the apolipoprotein association state seems to be intermediate between that in solution and in larger vesicular complex (1000:1); for both complexes, the degree of exposure of fluorescein chromophores into water phase decreased. Hetero-associates of apoA-I and apoC-III-1 in solution and in the complexes with DMPC appear to behave similarly to apoE. When extrapolated to native HDL particles, 'molten globule' state seems to be a structure responsible for the interaction of exchangeable apolipoproteins with phospholipid. For a first time, the location of various apolipoprotein molecules on disc periphery was confirmed. The lysine residue(s) seems to locate closely to reacting residue(s) within apolipoprotein molecules in associates, however, with different package constraints for discoidal versus vesicular complexes with phospholipid.

  13. Software development support for AI programs

    SciTech Connect

    Ramamoorthy, C.V.; Shekhar, S.; Garg, V.

    1987-01-01

    Artificial intelligence is a growing branch of computer science that studies ways of enabling computers to do tasks that seem to require human intelligence. These tasks include game playing, expert problem solving, natural language understanding, and theorem proving. Many existing AI programs perform such tasks with varying degrees of success. Whereas a program that can understand natural language is still a dream, many chess-playing programs can beat expert human players. More successful AI programs include knowledge-based expert systems that are being applied to a wide spectrum of real-life problems from airline catering to oil exploration. These systems can acquire knowledge about a domain from a human expert and then use it to solve routine problems in that area. For example, expert systems can perform almost as well as human experts in the diagnosis of infectious diseases (MYCIN), finding the structure of chemical compounds (DENDRAL), and performing mathematical symbol manipulations (MACSYMA). These AI systems offer new capabilities to tackle several problems difficult to solve using the conventional algorithmic approach.

  14. The gender-specific apolipoprotein E genotype influence on the distribution of plasma lipids and apolipoproteins in the population of Rochester, MN. III. Correlations and covariances

    SciTech Connect

    Reilly, S.L.; Sing, C.F.; Ferrell, R.E.

    1994-11-01

    The gender-specific influence that the apolipoprotein E (Apo E) polymorphism has on the correlations and covariances between pairs of nine plasma lipid and apolipoprotein traits (total cholesterol; ln triglycerides; high-density-lipoprotein cholesterol; apolipoproteins AI, AII, B, CII, lnCIII, and lnE) was studied in 507 unrelated individuals representative of the adult population of Rochester, MN. Analyses are presented separately for females and males. The Apo E polymorphism had a significant influence on a large number (10 of 36) of correlations and covariances in females and on a small number of (3 of 36) in males. The contribution of allelic variation in the Apo E gene to the definition of multivariate measures of the 36-dimensional correlation structure was evaluated. The influence of APo E genotype on correlation structure was gender dependent. These findings were used to demonstrate how heterogeneity of risk-factor correlations and covariances among genotype-gender subgroups of the population at large may influence the evaluation of risk of coronary artery disease. 73 refs., 8 figs., 4 tabs.

  15. D25V apolipoprotein C-III variant causes dominant hereditary systemic amyloidosis and confers cardiovascular protective lipoprotein profile.

    PubMed

    Valleix, Sophie; Verona, Guglielmo; Jourde-Chiche, Noémie; Nédelec, Brigitte; Mangione, P Patrizia; Bridoux, Frank; Mangé, Alain; Dogan, Ahmet; Goujon, Jean-Michel; Lhomme, Marie; Dauteuille, Carolane; Chabert, Michèle; Porcari, Riccardo; Waudby, Christopher A; Relini, Annalisa; Talmud, Philippa J; Kovrov, Oleg; Olivecrona, Gunilla; Stoppini, Monica; Christodoulou, John; Hawkins, Philip N; Grateau, Gilles; Delpech, Marc; Kontush, Anatol; Gillmore, Julian D; Kalopissis, Athina D; Bellotti, Vittorio

    2016-01-01

    Apolipoprotein C-III deficiency provides cardiovascular protection, but apolipoprotein C-III is not known to be associated with human amyloidosis. Here we report a form of amyloidosis characterized by renal insufficiency caused by a new apolipoprotein C-III variant, D25V. Despite their uremic state, the D25V-carriers exhibit low triglyceride (TG) and apolipoprotein C-III levels, and low very-low-density lipoprotein (VLDL)/high high-density lipoprotein (HDL) profile. Amyloid fibrils comprise the D25V-variant only, showing that wild-type apolipoprotein C-III does not contribute to amyloid deposition in vivo. The mutation profoundly impacts helical structure stability of D25V-variant, which is remarkably fibrillogenic under physiological conditions in vitro producing typical amyloid fibrils in its lipid-free form. D25V apolipoprotein C-III is a new human amyloidogenic protein and the first conferring cardioprotection even in the unfavourable context of renal failure, extending the evidence for an important cardiovascular protective role of apolipoprotein C-III deficiency. Thus, fibrate therapy, which reduces hepatic APOC3 transcription, may delay amyloid deposition in affected patients. PMID:26790392

  16. D25V apolipoprotein C-III variant causes dominant hereditary systemic amyloidosis and confers cardiovascular protective lipoprotein profile

    PubMed Central

    Valleix, Sophie; Verona, Guglielmo; Jourde-Chiche, Noémie; Nédelec, Brigitte; Mangione, P. Patrizia; Bridoux, Frank; Mangé, Alain; Dogan, Ahmet; Goujon, Jean-Michel; Lhomme, Marie; Dauteuille, Carolane; Chabert, Michèle; Porcari, Riccardo; Waudby, Christopher A.; Relini, Annalisa; Talmud, Philippa J.; Kovrov, Oleg; Olivecrona, Gunilla; Stoppini, Monica; Christodoulou, John; Hawkins, Philip N.; Grateau, Gilles; Delpech, Marc; Kontush, Anatol; Gillmore, Julian D.; Kalopissis, Athina D.; Bellotti, Vittorio

    2016-01-01

    Apolipoprotein C-III deficiency provides cardiovascular protection, but apolipoprotein C-III is not known to be associated with human amyloidosis. Here we report a form of amyloidosis characterized by renal insufficiency caused by a new apolipoprotein C-III variant, D25V. Despite their uremic state, the D25V-carriers exhibit low triglyceride (TG) and apolipoprotein C-III levels, and low very-low-density lipoprotein (VLDL)/high high-density lipoprotein (HDL) profile. Amyloid fibrils comprise the D25V-variant only, showing that wild-type apolipoprotein C-III does not contribute to amyloid deposition in vivo. The mutation profoundly impacts helical structure stability of D25V-variant, which is remarkably fibrillogenic under physiological conditions in vitro producing typical amyloid fibrils in its lipid-free form. D25V apolipoprotein C-III is a new human amyloidogenic protein and the first conferring cardioprotection even in the unfavourable context of renal failure, extending the evidence for an important cardiovascular protective role of apolipoprotein C-III deficiency. Thus, fibrate therapy, which reduces hepatic APOC3 transcription, may delay amyloid deposition in affected patients. PMID:26790392

  17. Identification of apolipoprotein using feature selection technique.

    PubMed

    Tang, Hua; Zou, Ping; Zhang, Chunmei; Chen, Rong; Chen, Wei; Lin, Hao

    2016-01-01

    Apolipoprotein is a kind of protein which can transport the lipids through the lymphatic and circulatory systems. The abnormal expression level of apolipoprotein always causes angiocardiopathy. Thus, correct recognition of apolipoprotein from proteomic data is very crucial to the comprehension of cardiovascular system and drug design. This study is to develop a computational model to predict apolipoproteins. In the model, the apolipoproteins and non-apolipoproteins were collected to form benchmark dataset. On the basis of the dataset, we extracted the g-gap dipeptide composition information from residue sequences to formulate protein samples. To exclude redundant information or noise, the analysis of various (ANOVA)-based feature selection technique was proposed to find out the best feature subset. The support vector machine (SVM) was selected as discrimination algorithm. Results show that 96.2% of sensitivity and 99.3% of specificity were achieved in five-fold cross-validation. These findings open new perspectives to improve apolipoproteins prediction by considering the specific dipeptides. We expect that these findings will help to improve drug development in anti-angiocardiopathy disease. PMID:27443605

  18. Identification of apolipoprotein using feature selection technique

    PubMed Central

    Tang, Hua; Zou, Ping; Zhang, Chunmei; Chen, Rong; Chen, Wei; Lin, Hao

    2016-01-01

    Apolipoprotein is a kind of protein which can transport the lipids through the lymphatic and circulatory systems. The abnormal expression level of apolipoprotein always causes angiocardiopathy. Thus, correct recognition of apolipoprotein from proteomic data is very crucial to the comprehension of cardiovascular system and drug design. This study is to develop a computational model to predict apolipoproteins. In the model, the apolipoproteins and non-apolipoproteins were collected to form benchmark dataset. On the basis of the dataset, we extracted the g-gap dipeptide composition information from residue sequences to formulate protein samples. To exclude redundant information or noise, the analysis of various (ANOVA)-based feature selection technique was proposed to find out the best feature subset. The support vector machine (SVM) was selected as discrimination algorithm. Results show that 96.2% of sensitivity and 99.3% of specificity were achieved in five-fold cross-validation. These findings open new perspectives to improve apolipoproteins prediction by considering the specific dipeptides. We expect that these findings will help to improve drug development in anti-angiocardiopathy disease. PMID:27443605

  19. Two amino acid substitutions in apolipoprotein B are in complete allelic association with the antigen group (x/y) polymorphism: Evidence for little recombination in the 3 prime end of the human gene

    SciTech Connect

    Dunning, A.M.; Renges, H.H.; Xu, Chunfang; Peacock, R.; Humphries, S.E.; Talmud, P.; Laxer, G. ); Brasseur, R. ); Tikkanen, M.J. ); Buetler, R. ); Saha, N. ); Hamsten, A. ); Rosseneu, M. )

    1992-01-01

    The authors report the identification of an A-to-G base change, in exon 29 of the apolipoprotein B (apo B) gene, that results in the substitution of serine for asparagine at residue 4,311 of mature apo B100. In a recent publication, Huang et al. have reported a C-to-T base change in exon 26 that causes the substitution of leucine for proline at residue 2712 of apo B. The authors have found complete linkage disequilibrium between the alleles at both these sites and an immunochemical polymorphism of LDL designated antigen group (x/y) (Ag(x/y)) in a sample of 118 Finnish individuals. This implies that either one of these substitutions - or both of them combined - could be the molecular basis of the Ag(x/y) antigenic determinants, with the allele encoding serine{sub 4311} plus leucine{sub 2,712} representing the Ag(x) epitope, and that encoding asparagine{sub 4,311} plus proline{sub 2,712} the Ag(y) epitope. In a sample of 90 healthy Swedish individuals the Leu{sub 2,712}/Ser{sub 4,311} allele is associated both with reduced serum levels of LDL cholesterol and apo B and with raised levels of HDL. They have also genotyped 523 individuals from European, Asian, Chinese, and Afro-Caribbean populations and have found complete association between the sites encoding residues 2,712 and 4,311 in all of these samples, although there are large allele frequency differences between these populations. Taken together, these data suggest that, since the divergence of the major ethnic groups, there has been little or no recombination in the 3' end of the human apo B gene.

  20. Changes of Apolipoprotein M Gene Expression During the Cell Differentiation and Apoptosis Induced by Simvastatin in Combination with All-Trans Retinoic Acid in Human Promyelocytic Leukemia Cell Line NB4.

    PubMed

    Gu, Weiying; Xiang, Lili; Jiang, Tingxiu; Luo, Guanghua; Wei, Jiang; Cen, Jiannong; Chen, Zixing; Qiu, Guoqiang; Zeng, Mei; Zhang, Xiaoying

    2016-03-01

    We examined the effect of simvastatin (SV) alone and in combination with all-trans retinoic acid (ATRA) on proliferation, differentiation, apoptosis and apolipoprotein M (apoM) expression in the human promyelocytic leukemia cell line NB4. The NB4 cells were incubated with 10 μM Simvastatin (10SV) and 0.5 μM ATRA alone or in combination, taking NB4 cells without any treatment as normal controls. The cells of different groups were collected at 24, 48 and 72 h post-incubation for further detection. Their morphological changes were observed after Wright stain. MTT method was used to assay the growth inhibition rate and flow cytometry to detect CD11b expression level and the early stage apoptosis ratio. Real-time quantitative reverse transcriptase-polymerase chain reaction was used to detect the apoM gene expression levels. As expected 0.5 μM ATRA did not affect proliferation or apoptosis, strongly induced differentiation and decreased apoM expression. 10SV inhibited proliferation, increased apoptosis, induced differentiation and increased apoM expression in a time-dependent manner. The addition of ATRA to SV did not increase the effect of SV on proliferation and apoptosis, but increased the effect of SV on differentiation. And completely abrogated the effect of SV on apoM expression. Together these results show that SV has anti-leukemic properties by itself and that combined therapy may have a place in the current anti-leukemic arsenal. PMID:26855507

  1. Transcriptional Regulation of Apolipoprotein A5 Gene Expression by the Nuclear Receptor ROR alpha

    SciTech Connect

    Genoux, Annelise; Dehondt, Helene; Helleboid-Chapman, Audrey; Duhem, Christian; Hum, Dean W.; Martin, Genevieve; Pennacchio, Len; Staels, Bart; Fruchart-Najib, Jamila; Fruchart, Jean-Charles

    2004-10-01

    Apolipoprotein A5 has recently been identified as a crucial determinant of plasma triglyceride levels. Our results showed that RORa up-regulates human APOA5 but has no effect on mouse apoa5 promoter. These data suggest an additional important physiological role for RORa in the regulation of genes involved in plasma triglyceride homeostasis in human and probably in the development of atherosclerosis

  2. Human creatine kinase genes on chromosomes 15 and 19, and proximity of the gene for the muscle form to the genes for apolipoprotein C2 and excision repair.

    PubMed Central

    Stallings, R L; Olson, E; Strauss, A W; Thompson, L H; Bachinski, L L; Siciliano, M J

    1988-01-01

    The human chromosomal assignments of genes of the creatine kinase (CK) family--loci for brain (CKBB), muscle (CKMM), and mitochondrial (CKMT) forms--were studied by Southern filter hybridization analysis of DNAs isolated from a human x rodent somatic cell hybrid clone panel. Probes for the 3'-noncoding sequences of human CKBB and CKMM hybridized concordantly only to DNAs from somatic cell hybrids containing chromosomes 14 and 19, respectively. Thus the earlier assignment of the gene coding for the CKBB isozyme to chromosome 14 was confirmed by molecular means, as was the provisional assignment of CKMM to the long arm of chromosome 19. A probe containing canine sequences for CKMM cross-hybridized with human sequences on chromosomes 14 and 19, a result consistent with the assignments of CKBB and CKMM. A probe containing human sequences for CKMT enabled the provisional assignment of CKMT to human chromosome 15. Independent hybrids with portions of the long arm of chromosome 19 missing indicated the order of genes on the long arm of chromosome 19 as being cen-GPI-(TGFB, CYP1)-[CKMM, (APOC2-ERCC1)]-(CGB, FTL). The unexpectedly more distal location of APOC2 among the genes on the long arm--and APOC2's close association with CKMM--is discussed with respect to the close linkage relationship of APOC2 to myotonic muscular dystrophy. Images Figure 1 PMID:3400641

  3. Code AI Personal Web Pages

    NASA Technical Reports Server (NTRS)

    Garcia, Joseph A.; Smith, Charles A. (Technical Monitor)

    1998-01-01

    The document consists of a publicly available web site (george.arc.nasa.gov) for Joseph A. Garcia's personal web pages in the AI division. Only general information will be posted and no technical material. All the information is unclassified.

  4. Typical and atypical AIS. Pathogenesis.

    PubMed

    Dudin, M; Pinchuk, D

    2012-01-01

    AIS hypothesis has the right to recognition, if it explains the transition of "healthy" vertebra column into status of "scoliotic" one. AIS is the most investigated disease in the history of orthopedics, but up the present time there is no clear explanation of some its phenomena: vertebra column mono-form deformation along with its poly etiology character, interrelation of its origin and development and child's growth process etc. The key for authors' view at AIS was scoliosis with non-standard (concave side) rotation. On the bases of its' multifunctional instrumental investigation results (Rtg, EMG, EEG, optical topography, hormonal and neuropeptides trials, thermo-vision methods and other) in comparison with typical AIS was worked out the new hypothesis, part of it is suggested for discussion. In the work under observation is the sequence of appearance of typical and atypical scoliosis symptomatology beginning from the preclinical stage. PMID:22744477

  5. Acute effects of moderate exercise on serum lipids, lipoproteins and apolipoproteins in sedentary young women.

    PubMed

    Imamura, H; Katagiri, S; Uchid, K; Miyamoto, N; Nakano, H; Shirota, T

    2000-12-01

    1. The aim of the present study was to examine the effects of moderate exercise on serum lipids, lipoproteins and apolipoproteins in seven sedentary young women under controlled conditions. 2. The subjects exercised on separate days for 30 or 60 min at an intensity of 60% of maximal oxygen uptake on a cycle ergometer. Total cholesterol, triglycerides, high-density lipoprotein-cholesterol (HDL-C), HDL2-C, HDL3-C, low-density lipoprotein-cholesterol, apolipoproteins A-I, A-II and B were measured in the serum at the end of the 60 min rest period before each exercise, immediately after the performance of each exercise and at 30 min and 1, 2 and 24 h after each exercise. 3. The results showed that there were no significant differences between the pre- and postexercise samples for any of the parameters tested. 4. The results of the present study suggest that a single bout of exercise designed to simulate a typical training workout has no noticeable effect on serum lipids, lipoproteins and apolipoproteins in normal sedentary young women who have normal lipid profiles, are in the follicular phase of their menstrual cycle and who consume a relatively low-fat diet. PMID:11117233

  6. Proteomic identification of altered apolipoprotein patterns in pulmonary hypertension and vasculopathy of sickle cell disease

    PubMed Central

    Yuditskaya, Susan; Tumblin, Ashaunta; Hoehn, Gerard T.; Wang, Guanghui; Drake, Steven K.; Xu, Xiuli; Ying, Saixia; Chi, Amy H.; Remaley, Alan T.; Shen, Rong-Fong; Munson, Peter J.; Suffredini, Anthony F.

    2009-01-01

    Pulmonary arterial hypertension (PAH) is emerging as a major complication and independent risk factor for death among adults with sickle cell disease (SCD). Using surface-enhanced laser desorption/ionization time of flight mass spectrometry (SELDI-TOF MS), we searched for biomarkers of PAH in plasma specimens from 27 homozygous sickle cell anemia (HbSS) patients with PAH and 28 without PAH. In PAH patients, analysis consistently showed lower abundance of a 28.1-kDa peak (P < .001), identified by high-resolution mass spectrometry as the oxidant-scavenging protein apolipoprotein A-I (apoA-I), which correlated with clinical assays of apoA-I (r = .58, P < .001) and high-density lipoprotein (HDL) levels (r = .50, P = .001). Consistent with endothelial dysfunction that may mediate this effect in PAH, HbSS patients with lower apoA-I levels also displayed impaired vasodilatory responses to acetylcholine (mean ± SEM, 189% ± 34% [n = 13] vs 339% ± 51% [n = 13], P < .001). As a group, patients with SCD demonstrated significantly lower apoA-I levels than African-American control subjects. The PAH cohort was further characterized by high levels of apolipoproteins A-II and B and serum amyloid A, and low levels of haptoglobin dimers and plasminogen. These results imply a relationship of apolipoproteins to the development of PAH vasculopathy in SCD, potentially involving an unexpected mechanistic parallel to atherosclerosis, another proliferative vasculopathy. PMID:19023114

  7. Role of apolipoprotein E in neurodegenerative diseases

    PubMed Central

    Giau, Vo Van; Bagyinszky, Eva; An, Seong Soo A; Kim, Sang Yun

    2015-01-01

    Apolipoprotein E (APOE) is a lipid-transport protein abundantly expressed in most neurons in the central nervous system. APOE-dependent alterations of the endocytic pathway can affect different functions. APOE binds to cell-surface receptors to deliver lipids and to the hydrophobic amyloid-β peptide, regulating amyloid-β aggregations and clearances in the brain. Several APOE isoforms with major structural differences were discovered and shown to influence the brain lipid transport, glucose metabolism, neuronal signaling, neuroinflammation, and mitochondrial function. This review will summarize the updated research progress on APOE functions and its role in Alzheimer’s disease, Parkinson’s disease, cardiovascular diseases, multiple sclerosis, type 2 diabetes mellitus, Type III hyperlipoproteinemia, vascular dementia, and ischemic stroke. Understanding the mutations in APOE, their structural properties, and their isoforms is important to determine its role in various diseases and to advance the development of therapeutic strategies. Targeting APOE may be a potential approach for diagnosis, risk assessment, prevention, and treatment of various neurodegenerative and cardiovascular diseases in humans. PMID:26213471

  8. Structural organization of lipid phase and protein-lipid interface in apolipoprotein-phospholipid recombinants: influence of cholesterol.

    PubMed

    Dergunov, A D; Taveirne, J; Vanloo, B; Caster, H; Rosseneu, M

    1997-06-01

    The complexes of individual human plasma apolipoproteins (apo) A-I, E and A-II with dipalmitoylphosphatidylcholine (DPPC) in the absence or in the presence of cholesterol (Chol) were prepared with initial DPPC/Chol/protein weight ratio as 3:0.15:1. ApoA-I/DPPC/Chol complexes with different protein content (initial DPPC/apoA-I weight ratios were changed from 10.5:1 to 2.6:1) but with a fixed initial DPPC/Chol weight ratio of 20:1 were also prepared. The complexes were isolated by gel-filtration and characterized by size and composition. ApoA-I- and apoA-II-complexes had the same size (80-84 A) and the complexes became more heterogeneous upon Chol inclusion; apoE-complexes were larger (97-100 A) and more homogeneous and Chol addition had no effect on their hydrodynamic properties. Chol seems to be excluded partially in the following manner for isolated complexes with different apo's: A-II > E > A-I. The possible existence of two lipid regions in the complexes differing in lipid dynamics - the lipid shell in the vicinity of apolipoprotein (boundary lipid) opposite to the remaining part of the lipid bilayer - has been studied by absorbance and fluorescence spectroscopy with cis-parinaric acid (cis-PA) and trans-parinaric acid (trans-PA) embedded into the complexes. Their application is based on a strong preference of trans-PA for solid lipid while cis-PA distributes more equally between co-existing fluid and solid lipid regions (Sklar et al. (1979) Biochemistry 18, 1707-1716). (1) For apoA-I-complexes, the partition of cis-PA between water and lipid phase at temperatures below and above the transition temperature of DPPC (T(t)) was insensitive to Chol and temperature, while partition of trans-PA into the lipid phase of Chol-containing complex was increased at high temperature and decreased at low temperature. These results seem to be related to trans-PA redistribution between Chol-rich and protein-rich lipid domains, the latter being more disordered at T < T(t) and

  9. The impact of plasma triglyceride and apolipoproteins concentrations on high-density lipoprotein subclasses distribution

    PubMed Central

    2011-01-01

    Objective To investigate the effect of triglyceride (TG) integrates with plasma major components of apolipoproteins in HDL subclasses distribution and further elicited the TG-apolipoproteins (apos) interaction in the processes of high density lipoprotein (HDL) mature metabolic and atherosclerosis related diseases. Methods Contents of plasma HDL subclasses were quantities by two-dimensional gel electrophoresis associated with immunodetection in 500 Chinese subjects. Results Contents of preβ1-HDL, HDL3a, and apoB-100 level along with apoB-100/A-I ratio were significantly increased, whereas there was a significant reduction in the contents of HDL2, apoA-I level as well as apoC-III/C-II ratio with increased TG concentration. Moreover, preβ1-HDL contents is elevated about 9 mg/L and HDL2b contents can be reduced 21 mg/L for 0.5 mmol/L increment in TG concentration. Moreover, with increase of apoA-I levels, HDL2b contents were marginally elevated in any TG concentration group. Furthermore, despite of in the apoB-100/A-I < 0.9 group, the contents of preβ1-HDL increased, and those of HDL2b decreased significantly for subjects in both high and very high TG levels compared to that in normal TG levels. Similarly, in the apoB-100/A-I ≥ 0.9 group, the distribution of HDL subclasses also showed abnormality for subjects with normal TG levels. Conclusions The particle size of HDL subclasses tend to small with TG levels increased which indicated that HDL maturation might be impeded and efficiency of reverse cholesterol transport(RCT) might be weakened. These data suggest that TG levels were not only significantly associated with but liner with the contents of preβ1-HDL and HDL2b. They also raise the possibility that the TG levels effect on HDL maturation metabolism are subjected to plasma apolipoproteins and apolipoproteins ratios. PMID:21251287

  10. Differential expression of oxidation-specific epitopes and apolipoprotein(a) in progressing and ruptured human coronary and carotid atherosclerotic lesions.

    PubMed

    van Dijk, Rogier A; Kolodgie, Frank; Ravandi, Amir; Leibundgut, Gregor; Hu, Patrick P; Prasad, Anand; Mahmud, Ehtisham; Dennis, Edward; Curtiss, Linda K; Witztum, Joseph L; Wasserman, Bruce A; Otsuka, Fumiyuki; Virmani, Renu; Tsimikas, Sotirios

    2012-12-01

    The relationships between oxidation-specific epitopes (OSE) and lipoprotein (a) [Lp(a)] and progressive atherosclerosis and plaque rupture have not been determined. Coronary artery sections from sudden death victims and carotid endarterectomy specimens were immunostained for apoB-100, oxidized phospholipids (OxPL), apo(a), malondialdehyde-lysine (MDA), and MDA-related epitopes detected by antibody IK17 and macrophage markers. The presence of OxPL captured in carotid and saphenous vein graft distal protection devices was determined with LC-MS/MS. In coronary arteries, OSE and apo(a) were absent in normal coronary arteries and minimally present in early lesions. As lesions progressed, apoB and MDA epitopes did not increase, whereas macrophage, apo(a), OxPL, and IK17 epitopes increased proportionally, but they differed according to plaque type and plaque components. Apo(a) epitopes were present throughout early and late lesions, especially in macrophages and the necrotic core. IK17 and OxPL epitopes were strongest in late lesions in macrophage-rich areas, lipid pools, and the necrotic core, and they were most specifically associated with unstable and ruptured plaques. Specific OxPL were present in distal protection devices. Human atherosclerotic lesions manifest a differential expression of OSEs and apo(a) as they progress, rupture, and become clinically symptomatic. These findings provide a rationale for targeting OSE for biotheranostic applications in humans. PMID:22969153

  11. Relevance of apolipoproteins in the development of fatty liver and fatty liver-related peripartum diseases in dairy cows.

    PubMed

    Katoh, Norio

    2002-04-01

    Most metabolic diseases in dairy cows occur during the peripartum period and are suggested to be derived from fatty liver initially developed during the nonlactating stage. Fatty liver is induced by hepatic uptake of nonesterified fatty acids that are released in excess by adipose tissues attributable to negative energy balance. The fatty accumulation leads to impairment of lipoprotein metabolism in the liver, and the impairment in turn influences other metabolic pathways in extrahepatic tissues such as the steroid hormone production by the corpus luteum. Detailed understanding of the impaired lipoprotein metabolism is crucial for elucidation of the mechanistic bases of the development of fatty liver and fatty liver-related peripartum diseases. This review summarizes results on evaluation of lipoprotein lipid and protein concentrations and enzyme activity in cows with fatty liver and those with ketosis, left displacement of the abomasum, milk fever, downer syndrome and retained placenta. Obtained data strongly suggest that decreases in serum concentrations of apolipoprotein B-100, apolipoprotein A-I and apolipoprotein C-III, a reduction in activity of lecithin:cholesterol acyltransferase and induction of haptoglobin and serum amyloid A are intimately related to the development of fatty liver and fatty liver-related diseases. Moreover, determination of the apolipoprotein concentrations and enzyme activity during the peripartum period is useful for early diagnoses of these diseases. PMID:12014573

  12. Two initiator-like elements are required for the combined activation of the human apolipoprotein C-III promoter by upstream stimulatory factor and hepatic nuclear factor-4.

    PubMed

    Pastier, Daniele; Lacorte, Jean-Marc; Chambaz, Jean; Cardot, Philippe; Ribeiro, Agnes

    2002-04-26

    Human apoC-III (-890/+24) promoter activity is strongly activated by hepatic nuclear factor (HNF)-4 through its binding to the proximal (-87/-72) element B. This site overlaps the binding site for an activity that we identified as the ubiquitously expressed upstream stimulatory factor (USF) (Ribeiro, A., Pastier, D., Kardassis, D., Chambaz, J., and Cardot, P. (1999) J. Biol. Chem. 274, 1216-1225). In the present study, we characterized the relationship between USF and HNF-4 in the activation of human apoC-III transcription. Although USF and HNF-4 binding to element B is mutually exclusive, co-transfection experiments in HepG2 cells surprisingly showed a combined effect of USF and HNF-4 in the transactivation of the (-890/+24) apoC-III promoter. This effect only requires the proximal region (-99/+24) of the apoC-III promoter and depends neither on USF binding to its cognate site in element B nor on a USF-dependent facilitation of HNF-4 binding to its site. By contrast, we found by electrophoretic mobility shift assay and footprinting analysis two USF low affinity binding sites, located within the proximal promoter at positions -58/-31 (element II) and -19/-4 (element I), which are homologous to initiator-like element sequence. Co-transfection experiments in HepG2 cells show that a mutation in element II reduces 2-fold the USF transactivation effect on the proximal promoter of apoC-III and that a mutation in element I inhibits the combined effect of USF and HNF-4. In conclusion, these initiator-like elements are directly involved in the transactivation of the apoC-III promoter by USF and are necessary to the combined effect between USF and HNF-4 for the apoC-III transcription. PMID:11839757

  13. Inhibitory effects of oleoylethanolamide (OEA) on H2O2-induced human umbilical vein endothelial cell (HUVEC) injury and apolipoprotein E knockout (ApoE-/-) atherosclerotic mice

    PubMed Central

    Ma, Li; Guo, Xiaobing; Chen, Wei

    2015-01-01

    Atherosclerosis (AS) is initiated by vascular endothelial cell injury, which is induced by lipid and protein oxidation. Oleoylethanolamide (OEA), a dietary fat-derived lipid, has shown atheroprotective effect. In vitro studies demonstrated that OEA showed cytoprotective effects on H2O2-induced primary cultured human umbilical vein endothelial cell (HUVEC) injury model. Further investigation of the cytoprotective effects of OEA demonstrated that OEA exerted its function by scavenging for reactive oxygen species, as well as increasing anti-oxidative enzymes, reducing lipid peroxidation, terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL)-positive cells and apoptosis-related proteins expression. The in vivo study using an ApoE-/- mouse model fed with high-fat diet for 8 weeks showed that OEA (10 mg/kg/day, i.g.) administration reduced blood lipid levels, prevented endothelial cell damage and inhibited early AS plaque formation. In conclusion, our results suggested that OEA exerted a pharmacological effect on ameliorating atherosclerotic plaque formation through the inhibition of oxidative stress-induced endothelial cell injury and therefore OEA can be a potential candidate drug for anti-atherosclerosis. PMID:26261506

  14. Inhibitory effects of oleoylethanolamide (OEA) on H₂O₂-induced human umbilical vein endothelial cell (HUVEC) injury and apolipoprotein E knockout (ApoE-/-) atherosclerotic mice.

    PubMed

    Ma, Li; Guo, Xiaobing; Chen, Wei

    2015-01-01

    Atherosclerosis (AS) is initiated by vascular endothelial cell injury, which is induced by lipid and protein oxidation. Oleoylethanolamide (OEA), a dietary fat-derived lipid, has shown atheroprotective effect. In vitro studies demonstrated that OEA showed cytoprotective effects on H2O2-induced primary cultured human umbilical vein endothelial cell (HUVEC) injury model. Further investigation of the cytoprotective effects of OEA demonstrated that OEA exerted its function by scavenging for reactive oxygen species, as well as increasing anti-oxidative enzymes, reducing lipid peroxidation, terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL)-positive cells and apoptosis-related proteins expression. The in vivo study using an ApoE-/- mouse model fed with high-fat diet for 8 weeks showed that OEA (10 mg/kg/day, i.g.) administration reduced blood lipid levels, prevented endothelial cell damage and inhibited early AS plaque formation. In conclusion, our results suggested that OEA exerted a pharmacological effect on ameliorating atherosclerotic plaque formation through the inhibition of oxidative stress-induced endothelial cell injury and therefore OEA can be a potential candidate drug for anti-atherosclerosis. PMID:26261506

  15. Two amino acid substitutions in apolipoprotein B are in complete allelic association with the antigen group (x/y) polymorphism: Evidence for little recombination in the 3' end of the human gene

    PubMed Central

    Dunning, Alison M.; Renges, Helmut-H.; Xu, Chun-Fang; Peacock, Rachel; Brasseur, Robert; Laxer, Gerald; Tikkanen, Matti J.; Bütler, Réné; Saha, N.; Hamsten, Anders; Rosseneu, Maryvonne; Talmud, Philippa; Humphries, Steve E.

    1992-01-01

    We report the identification of an A-to-G base change, in exon 29 of the apolipoprotein B (apo B) gene, that results in the substitution of serine for asparagine at residue 4311 of mature apo B100. In a recent publication, Huang et al. have reported a C-to-T base change in exon 26 that causes the substitution of leucine for proline at residue 2712 of apo B. We have found complete linkage disequilibrium between the alleles at both these sites and an immunochemical polymorphism of LDL designated antigen group (x/y) (Ag(x/y)) in a sample of 118 Finnish individuals. This implies that either one of these substitutions–or both of them combined–could be the molecular basis of the Ag(x/y) antigenic determinants, with the allele encoding serine4311 plus leucine2712 representing the Ag(x) epitope, and that encoding asparagine4311 plus proline2712 the Ag(y) epitope. In a sample of 90 healthy Swedish individuals the Leu2712/Ser4311 allele is associated both with reduced serum levels of LDL-cholesterol and apo B and with raised levels of HDL. However, these differences are of smaller effect than those associated with the XbaI RFLP of the apo B gene in this sample. We have also genotyped 523 individuals from European, Asian, Chinese, and Afro-Caribbean populations and have found complete association between the sites encoding residues 2712 and 4311 in all of these samples, although there are large allele frequency differences between these populations. In addition, there is strong linkage disequilibrium with allelic association between the alleles of these sites and those of the XbaI RFLP in all the populations examined. Taken together, these data suggest that, since the divergence of the major ethnic groups, there has been little or no recombination in the 3' end of the human apo B gene. ImagesFigure 1Figure 2Figure 3 PMID:1370364

  16. Characterization of human plasma apolipoprotein E-containing lipoproteins in the high density lipoprotein size range: focus on pre-beta1-LpE, pre-beta2-LpE, and alpha-LpE.

    PubMed

    Krimbou, L; Tremblay, M; Davignon, J; Cohn, J S

    1997-01-01

    We have used two-dimensional gel electrophoresis to separate and characterize human plasma apolipoprotein (apo) E-containing lipoproteins in the high density lipoprotein (HDL) size range. Lipoproteins were separated from whole plasma by electrophoresis (according to charge) in a 0.75% agarose gel, and then in the second dimension (according to size) in a 2-15% non-denaturing polyacrylamide gradient gel. ApoE-containing lipoproteins were detected by radiography after electrotransfer of lipoproteins to nitrocellulose membranes and incubation with 125I-labeled affinity-purified polyclonal apoE antibody. ApoE-containing lipoproteins in the HDL size range had a particle size ranging from 9 to 18.5 nm in diameter and could be characterized as having either gamma, pre-beta1-, pre-beta2- or alpha-electrophoretic mobility (designated gamma-LpE, pre-beta1-LpE, pre-beta2LpE, and alpha-LpE respectively). gamma-LpE and a substantial proportion of pre-beta1- and pre-beta2-LpE did not co-migrate with apoA-I, apoA-II, apoC-III, or apoB-100. Subsequent experiments focused on the pre-beta1-LpE, pre-beta2LpE, and alpha-LpE subfractions, which represented > 95% of apoE in HDL-sized lipoproteins. Storage of plasma at 4 degrees C or in vitro incubation of plasma at 37 degrees C caused a relative decrease in pre-beta1-LpE and increase in alpha-LpE. Normolipidemic patients with an apoE 2/2 phenotype tended to have increased levels of alpha-LpE, whereas apoE 4/4 subjects tended to have a greater proportion of HDL-apoE as pre-beta1-LpE. Decrease in plasma HDL apoE concentration after an oral fat load was associated with a reduction in the plasma concentration of all HDL-apoE subfractions. These results demonstrate that: 1) apoE-containing HDL are heterogeneous in size and charge; 2) pre-beta1-LpE is a relatively labile HDL subfraction; 3) HDL-apoE subfraction distribution is dependent on apoE phenotype; and 4) all apoE-containing HDL subfractions participate in the plasma transfer of apo

  17. HDL-apolipoprotein A-I exchange is independently associated with cholesterol efflux capacity.

    PubMed

    Borja, Mark S; Ng, Kit F; Irwin, Angela; Hong, Jaekyoung; Wu, Xing; Isquith, Daniel; Zhao, Xue-Qiao; Prazen, Bryan; Gildengorin, Virginia; Oda, Michael N; Vaisar, Tomáš

    2015-10-01

    HDL is the primary mediator of cholesterol mobilization from the periphery to the liver via reverse cholesterol transport (RCT). A critical first step in this process is the uptake of cholesterol from lipid-loaded macrophages by HDL, a function of HDL inversely associated with prevalent and incident cardiovascular disease. We hypothesized that the dynamic ability of HDL to undergo remodeling and exchange of apoA-I is an important and potentially rate-limiting aspect of RCT. In this study, we investigated the relationship between HDL-apoA-I exchange (HAE) and serum HDL cholesterol (HDL-C) efflux capacity. We compared HAE to the total and ABCA1-specific cholesterol efflux capacity of 77 subjects. We found that HAE was highly correlated with both total (r = 0.69, P < 0.0001) and ABCA1-specific (r = 0.47, P < 0.0001) efflux, and this relationship remained significant after adjustment for HDL-C or apoA-I. Multivariate models of sterol efflux capacity indicated that HAE accounted for approximately 25% of the model variance for both total and ABCA1-specific efflux. We conclude that the ability of HDL to exchange apoA-I and remodel, as measured by HAE, is a significant contributor to serum HDL efflux capacity, independent of HDL-C and apoA-I, indicating that HDL dynamics are an important factor in cholesterol efflux capacity and likely RCT. PMID:26254308

  18. Conformational adaptation of apolipoprotein A-I to discretely sized phospholipid complexes.

    PubMed

    Bhat, Shaila; Sorci-Thomas, Mary G; Tuladhar, Rubina; Samuel, Michael P; Thomas, Michael J

    2007-07-01

    The conformational constraints for apoA-I bound to recombinant phospholipid complexes (rHDL) were attained from a combination of chemical cross-linking and mass spectrometry. Molecular distances were then used to refine models of lipid-bound apoA-I on both 80 and 96 A diameter rHDL particles. To obtain molecular constraints on the protein bound to phospholipid complexes, three different lysine-selective homo-bifunctional cross-linkers with increasing spacer arm lengths (i.e., 7.7, 12.0, and 16.1 A) were reacted with purified, homogeneous recombinant 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) apoA-I rHDL complexes of each diameter. Cross-linked dimeric apoA-I products were separated from monomeric apoprotein using 12% SDS-PAGE, then subjected to in-gel trypsin digest, and identified by MS/MS sequencing. These studies aid in the refinement of our previously published molecular model of two apoA-I molecules bound to approximately 150 molecules of POPC and suggest that the protein hydrophobic interactions at the N- and C-terminal domains decrease as the number of phospholipid molecules or "lipidation state" of apoA-I increases. Thus, it appears that these incremental changes in the interaction between the N- and C-terminal ends of apoA-I stabilize its tertiary conformation in the lipid-free state as well as allowing it to unfold and sequester discrete amounts of phospholipid molecules. PMID:17563120

  19. Extrahepatic synthesis of apolipoprotein E

    SciTech Connect

    Driscoll, D.M.; Getz, G.S.

    1984-12-01

    Apolipoprotein E (apoE) synthesis has been examined in rat and guinea pig tissues using in vitro translation and (/sup 35/S)methionine labeling of tissue slices. A number of tissues not involved in lipoprotein synthesis synthesize a protein very similar to apoE, including the spleen, adrenal, kidney, testis, ovary, heart, and lung. Although the intestine is involved in lipoprotein synthesis, apoE synthesis could not be detected in intestinal mucosa. The protein synthesized by the extrahepatic tissues was identified as apoE by its electrophoretic mobility, its immunologic reactivity with a monospecific antibody and by limited proteolysis mapping with Staphylococcus aureus V8 protease. ApoE represented between 0.02 and 0.7% of the total protein synthesized in the extrahepatic tissues, indicating that apoE mRNA is a fairly abundant mRNA in these tissues. ApoE mRNA was also detected by hybridization with a rat apoE cDNA clone, which hybridized to a single mRNA 1250 nucleotides in length in rat liver and in extrahepatic tissues. Hybridization of the apoE clone to rat genomic DNA demonstrated that the apoE gene was more heavily methylated in intestinal mucosa, which did not synthesize apoE, than in liver, testis, or kidney. /sup 35/S labeling of peritoneal macrophages revealed that both rat and guinea pig macrophages synthesized and secreted apoE in vitro. Rhesus aortic smooth muscle cells also synthesized and secreted apoE. The possible functions of apoE synthesized in the peripheral tissues are considered.

  20. A novel apolipoprotein C-II mimetic peptide that activates lipoprotein lipase and decreases serum triglycerides in apolipoprotein E-knockout mice.

    PubMed

    Amar, Marcelo J A; Sakurai, Toshihiro; Sakurai-Ikuta, Akiko; Sviridov, Denis; Freeman, Lita; Ahsan, Lusana; Remaley, Alan T

    2015-02-01

    Apolipoprotein A-I (apoA-I) mimetic peptides are currently being developed as possible new agents for the treatment of cardiovascular disease based on their ability to promote cholesterol efflux and their other beneficial antiatherogenic properties. Many of these peptides, however, have been reported to cause transient hypertriglyceridemia due to inhibition of lipolysis by lipoprotein lipase (LPL). We describe a novel bihelical amphipathic peptide (C-II-a) that contains an amphipathic helix (18A) for binding to lipoproteins and stimulating cholesterol efflux as well as a motif based on the last helix of apolipoprotein C-II (apoC-II) that activates lipolysis by LPL. The C-II-a peptide promoted cholesterol efflux from ATP-binding cassette transporter ABCA1-transfected BHK cells similar to apoA-I mimetic peptides. Furthermore, it was shown in vitro to be comparable to the full-length apoC-II protein in activating lipolysis by LPL. When added to serum from a patient with apoC-II deficiency, it restored normal levels of LPL-induced lipolysis and also enhanced lipolysis in serum from patients with type IV and V hypertriglyceridemia. Intravenous injection of C-II-a (30 mg/kg) in apolipoprotein E-knockout mice resulted in a significant reduction of plasma cholesterol and triglycerides of 38 ± 6% and 85 ± 7%, respectively, at 4 hours. When coinjected with the 5A peptide (60 mg/kg), the C-II-a (30 mg/kg) peptide was found to completely block the hypertriglyceridemic effect of the 5A peptide in C57Bl/6 mice. In summary, C-II-a is a novel peptide based on apoC-II, which promotes cholesterol efflux and lipolysis and may therefore be useful for the treatment of apoC-II deficiency and other forms of hypertriglyceridemia. PMID:25395590

  1. Marked increases in concentrations of apolipoprotein in the cerebrospinal fluid of poliovirus-infected macaques: relations between apolipoprotein concentrations and severity of brain injury.

    PubMed Central

    Saito, K; Seishima, M; Heyes, M P; Song, H; Fujigaki, S; Maeda, S; Vickers, J H; Noma, A

    1997-01-01

    Apolipoproteins in cerebrospinal fluid (CSF) might have important functional roles in the pathophysiology of brain and lipid metabolism in the vascular component. The present study examined apolipoprotein A-I (apo-A-I) and apolipoprotein E (apo-E) levels in CSF and serum from poliovirus-infected macaques. Poliovirus-infected macaques developed motor deficits and were classified into three groups: (1) muscle weakness in one or both legs; (2) partial paralysis in one or both legs; (3) complete paralysis in one or both legs. No motor deficits were evident in the control or sham-treated macaques. Apo-A-I concentrations in CSF were markedly elevated in poliovirus-infected macaques with weakness, partial or complete paralysis, in comparison with either control or sham-treated animals, and were proportional to the severity of motor impairment. Apo-E concentrations in CSF were also significantly elevated in poliovirus-infected macaques with complete paralysis. The magnitude of increase in CSF apo-A-I or apo-E concentrations was also closely associated with the degree of histologic neurological damage and inflammation (lesion scores). However, no changes in serum apo-A-I and apo-E concentrations were observed in the poliovirus-infected macaques compared with control macaques. Furthermore there were no significant correlations apo-A-I or apo-E concentrations between serum and CSF. We hypothesize that the elevation of apo-A-I and apo-E concentrations after poliovirus infection is caused by immune stimulation within the central nervous system (CNS). Measures of CSF apo-A-I and apo-E levels might serve as a useful marker for the severity and/or the range of CNS injury. PMID:9003413

  2. A Novel Apolipoprotein C-II Mimetic Peptide That Activates Lipoprotein Lipase and Decreases Serum Triglycerides in Apolipoprotein E–Knockout Mice

    PubMed Central

    Sakurai, Toshihiro; Sakurai-Ikuta, Akiko; Sviridov, Denis; Freeman, Lita; Ahsan, Lusana; Remaley, Alan T.

    2015-01-01

    Apolipoprotein A-I (apoA-I) mimetic peptides are currently being developed as possible new agents for the treatment of cardiovascular disease based on their ability to promote cholesterol efflux and their other beneficial antiatherogenic properties. Many of these peptides, however, have been reported to cause transient hypertriglyceridemia due to inhibition of lipolysis by lipoprotein lipase (LPL). We describe a novel bihelical amphipathic peptide (C-II-a) that contains an amphipathic helix (18A) for binding to lipoproteins and stimulating cholesterol efflux as well as a motif based on the last helix of apolipoprotein C-II (apoC-II) that activates lipolysis by LPL. The C-II-a peptide promoted cholesterol efflux from ATP-binding cassette transporter ABCA1-transfected BHK cells similar to apoA-I mimetic peptides. Furthermore, it was shown in vitro to be comparable to the full-length apoC-II protein in activating lipolysis by LPL. When added to serum from a patient with apoC-II deficiency, it restored normal levels of LPL-induced lipolysis and also enhanced lipolysis in serum from patients with type IV and V hypertriglyceridemia. Intravenous injection of C-II-a (30 mg/kg) in apolipoprotein E–knockout mice resulted in a significant reduction of plasma cholesterol and triglycerides of 38 ± 6% and 85 ± 7%, respectively, at 4 hours. When coinjected with the 5A peptide (60 mg/kg), the C-II-a (30 mg/kg) peptide was found to completely block the hypertriglyceridemic effect of the 5A peptide in C57Bl/6 mice. In summary, C-II-a is a novel peptide based on apoC-II, which promotes cholesterol efflux and lipolysis and may therefore be useful for the treatment of apoC-II deficiency and other forms of hypertriglyceridemia. PMID:25395590

  3. Familial apolipoprotein Al and apolipoprotein CIII deficiency: subclass distribution, composition, and morphology of lipoproteins in a disorder associated with premature atherosclerosis

    SciTech Connect

    Forte, T.M.; Nichols, A.V.; Krauss, R.M.; Norum, R.A.

    1984-11-01

    Lipoprotein classes isolated from the plasma of two patients with apolipoprotein AI (apo AI) and apolipoprotein CIII (apo CIII) deficiency were characterized and compared with those of healthy, age- and sex-matched controls. The plasma triglyceride values for patients 1 and 2 were 31 and 51 mg/dl, respectively, and their cholesterol values were 130 and 122 mg/dl, respectively; the patients, however, had no measurable high density lipoprotein (HDL)-cholesterol. Analytic ultracentrifugation showed that patients' S/sub f//sup 0/ 0-20 lipoproteins posses a single peak with S/sub f//sup 0/ rates of 7.4 and 7.6 for patients 1 and 2, respectively, which is similar to that of the controls. The concentration of low density lipoprotein (LDL) (S/sub f//sup 0/ 0-12) particles, although within normal range (331 and 343 mg/dl for patients 1 and 2, respectively), was 35% greater than that of controls. Intermediate density lipoproteins (IDL) and very low density lipoproteins (VLDL) (S/sub f//sup 0/ 20-400) were extremely low in the patients. HDL in the patients had a calculated mass of 15.4 and 11.8 mg/dl for patients 1 and 2, respectively. No HDL could be detected by analytic ultracentrifugation, but polyacrylamide gradient gel electrophoresis (gge) revealed that patients possessed two major HDL subclasses: (HDL/sub sb/)/sub gge/ at 11.0 nm and (HDL/sub 3b/)/sub gge/ at 7.8 nm. The major peak in the controls (HDL/sub 3a/)/sub gge/, was lacking in the patients.

  4. Portable AI Lab for Teaching Artificial Intelligence.

    ERIC Educational Resources Information Center

    Rosner, Michael; Baj, Fabio.

    1993-01-01

    Describes the Portable AI Lab, a computing environment containing artificial intelligence (AI) tools, examples, and documentation for use with university AI courses. Two modules of the lab are highlighted: the automated theorem proving module and the natural language processing module, which includes augmented transition networks. (23 references)…

  5. AIS Investigation of Agricultural Monocultures

    NASA Technical Reports Server (NTRS)

    Wood, B. L.; Wrigley, R. C.

    1985-01-01

    Airborne Imaging Spectrometer (AIS) data were acquired over an agricultural area in eastern San Joaquin County, California in July, 1984. Cover type information was subsequently collected for all fields along this flight line. The lack of detailed ground data on individual fields, however, limited AIS data analysis to a qualitative comparison of the spectral reflectance curves for a total of nine cover types. Based on this analysis, it appears that cover types with a positive slope in the 1550 to 1700 nm region have a higher spectral response in the 1200 to 1300 nm region compared to those cover types with a negative slope in the 1550 to 1700 nm region. Within cover type, spectral variability was also found to be greater than that between cover types. Given the lack of additional field data, the reason for these differences is a matter of speculation.

  6. Formal verification of AI software

    NASA Technical Reports Server (NTRS)

    Rushby, John; Whitehurst, R. Alan

    1989-01-01

    The application of formal verification techniques to Artificial Intelligence (AI) software, particularly expert systems, is investigated. Constraint satisfaction and model inversion are identified as two formal specification paradigms for different classes of expert systems. A formal definition of consistency is developed, and the notion of approximate semantics is introduced. Examples are given of how these ideas can be applied in both declarative and imperative forms.

  7. Comparative Effects of Diet-Induced Lipid Lowering Versus Lipid Lowering Along With Apo A-I Milano Gene Therapy on Regression of Atherosclerosis.

    PubMed

    Wang, Lai; Tian, Fang; Arias, Ana; Yang, Mingjie; Sharifi, Behrooz G; Shah, Prediman K

    2016-05-01

    Apolipoprotein A-1 (Apo A-I) Milano, a naturally occurring Arg173to Cys mutant of Apo A-1, has been shown to reduce atherosclerosis in animal models and in a small phase 2 human trial. We have shown the superior atheroprotective effects of Apo A-I Milano (Apo A-IM) gene compared to wild-type Apo A-I gene using transplantation of retrovirally transduced bone marrow in Apo A-I/Apo E null mice. In this study, we compared the effect of dietary lipid lowering versus lipid lowering plus Apo A-IM gene transfer using recombinant adeno-associated virus (rAAV) 8 as vectors on atherosclerosis regression in Apo A-I/Apo E null mice. All mice were fed a high-cholesterol diet from age of 6 weeks until week 20, and at 20 weeks, 10 mice were euthanized to determine the extent of atherosclerosis. After 20 weeks, an additional 20 mice were placed on either a low-cholesterol diet plus empty rAAV (n = 10) to serve as controls or low-cholesterol diet plus 1 single intravenous injection of 1.2 × 10(12)vector genomes of adeno-associated virus (AAV) 8 vectors expressing Apo A-IM (n = 10). At the 40 week time point, intravenous AAV8 Apo A-IM recipients showed a significant regression of atherosclerosis in the whole aorta (P< .01), aortic sinuses (P< .05), and brachiocephalic arteries (P< .05) compared to 20-week-old mice, whereas low-cholesterol diet plus empty vector control group showed no significant regression in lesion size. Immunostaining showed that compared to the 20-week-old mice, there was a significantly reduced macrophage content in the brachiocephalic (P< .05) and aortic sinus plaques (P< .05) of AAV8 Apo A-IM recipients. These data show that although dietary-mediated cholesterol lowering halts progression of atherosclerosis, it does not induce regression, whereas combination of low-cholesterol diet and AAV8 mediated Apo A-I Milano gene therapy induces rapid and significant regression of atherosclerosis in mice. These data provide support for the potential feasibility of this

  8. Can external quality control improve pig AI efficiency?

    PubMed

    Waberski, D; Petrunkina, A M; Töpfer-Petersen, E

    2008-11-01

    External quality control programmes carried out by central laboratories have been long established in human andrology with the aim of enhancing the accuracy and reproducibility of semen assessment. Compared to human, demands on boar semen assessment in AI stations are more complex, with the need both to identify boars with poor ejaculate quality and to monitor individual boar differences for semen storage. Additionally, appropriate assessment serves as a control instrument to ensure the security and efficiency of semen processing. Despite current limitations regarding the ability of sperm assays to estimate the potential fertility of males, it is evident that boar fertility is related to certain conventional semen tests, e.g. sperm morphology. In central studies carried out on stored semen from 11 AI stations, flow cytometric assessment of plasma and acrosome membrane integrity proved to be more sensitive in detecting sperm damage associated with ageing and temperature stress as compared to light microscopy. Membrane integrity of stored semen differed between AI stations indicating significant influences of semen processing on sperm quality. Thus external control of semen quality in reference laboratories may be useful to monitor the efficiency of internal semen quality control in individual AI stations, to identify males with lower semen quality and/or poor response to semen storage, and to verify the precision of sperm counting. The possibility that central laboratories with sufficient resources may be able to identify functionally different responding sperm subpopulations for better estimation of fertility is discussed. Ideally, external quality control schemes for AI stations would comprise application of validated tests with high relevance for fertility (including bacterial status), analysis of semen processing on the AI station, and training courses for laboratory personnel. PMID:18656253

  9. Native protein mapping and visualization of protein interactions in the area of human plasma high-density lipoprotein by combining nondenaturing micro 2DE and quantitative LC-MS/MS.

    PubMed

    Jin, Ya; Bu, Shujie; Zhang, Jun; Yuan, Qi; Manabe, Takashi; Tan, Wen

    2014-07-01

    A human plasma sample was subjected to nondenaturing micro 2DE and a gel area (5 mm × 18 mm) that includes high-density lipoprotein (HDL) was cut into 1 mm × 1 mm squares, then the proteins in the 90 gel pieces were analyzed by quantitative LC-MS/MS. Grid-cutting of the gel was employed to; (i) ensure the total analysis of the proteins in the area, (ii) standardize the conditions of analysis by LC-MS/MS, (iii) reconstruct the protein distribution patterns from the quantity data. Totally 154 proteins were assigned in the 90 gel pieces and the quantity distribution of each was reconstructed as a color density pattern (a native protein map). The map of apolipoprotein (Apo) A-I showed a wide apparent mass distribution characteristic to HDL and was compared with the maps of the other 153 proteins. Eleven proteins showed maps of wide distribution that overlapped with the map of Apo A-I, and all have been reported to be the components of HDL. Further, seven minor proteins associated with HDL were detected at the gel positions of high Apo A-I quantity. These results for the first time visualized the localization of HDL apolipoproteins on a nondenaturing 2DE gel and strongly suggested their interactions. PMID:24668886

  10. Associations of ApoAI and ApoB-containing Lipoproteins with AngII-induced Abdominal Aortic Aneurysms in Mice

    PubMed Central

    Liu, Jing; Lu, Hong; Howatt, Deborah A.; Balakrishnan, Anju; Moorleghen, Jessica J.; Sorci-Thomas, Mary; Cassis, Lisa A.; Daugherty, Alan

    2015-01-01

    Objective Dyslipidemia is implicated in abdominal aortic aneurysms (AAAs) in humans and angiotensin (Ang)II-infused mice. This study determined effects of major lipoprotein classes on AngII-induced AAAs using multiple mouse strains with dietary and pharmacological manipulations. Approach and Results Western diet had minor effects on plasma cholesterol concentrations and the low incidence of AngII-induced AAAs in C57BL/6J mice. Low incidence of AAAs in this strain was not attributed to protection from HDL, since apolipoprotein (apo)AI deficiency did not increase AngII-induced AAAs. ApoAI deletion also failed to alter AAA occurrence in hypercholesterolemic mice. Low density lipoprotein (LDL) receptor−/− mice fed normal diet had low incidence of AngII-induced AAAs. Western diet feeding of this strain provoked pronounced hypercholesterolemia due to increased apoB-containing lipoproteins with attendant increases of atherosclerosis in both genders, but AAAs only in male mice. ApoE−/− mice fed normal diet were modestly hypercholesterolemic, whereas this strain fed Western diet was severely hypercholesterolemic due to increased apoB-containing lipoprotein concentrations. The latter augmented atherosclerosis, but did not change the high incidence of AAAs in this strain. To determine whether reductions in apoB-containing lipoproteins influenced AngII-induced AAAs, ezetimibe was administered at a dose that partially reduced plasma cholesterol concentrations to apoE−/− mice fed Western diet. This decreased atherosclerosis, but not AAAs. This ezetimibe dose in apoE−/− mice fed normal diet significantly decreased plasma apoB-containing lipoprotein concentrations and reduced AngII-induced AAAs. Conclusions ApoB-containing lipoproteins contribute to augmentation of AngII-induced AAA in male mice. However, unlike atherosclerosis, AAA occurrence was not correlated with increases in plasma apoB-containing lipoprotein concentrations. PMID:26044581

  11. Normotriglyceridemic abetalipoproteinemia. absence of the B-100 apolipoprotein.

    PubMed Central

    Malloy, M J; Kane, J P; Hardman, D A; Hamilton, R L; Dalal, K B

    1981-01-01

    In the two genetic forms of abetalipoproteinemia described previously, recessive abetalipoproteinemia and homozygous hypobetalipoproteinemia, all lipoproteins that normally contain apolipoprotein B are absent from plasma. We describe here a new disorder in which normal low density and very low density lipoproteins are absent, but in which triglycerides are absorbed from the intestine and chylomicrons are present in plasma. The underlying molecular defect appears to be selective deletion of the hepatogenous B-100 apolipoprotein. The B-48 apolipoprotein found in chylomicrons is spared. These findings suggest that the two species of apolipoprotein B are under separate genetic control and that low density lipoproteins are not normally derived from chylomicrons. Images PMID:7229035

  12. Apolipoprotein E Polymorphism in Tuberculosis Patients

    NASA Astrophysics Data System (ADS)

    Naserpour Farivar, Taghi; Sharifi Moud, Batool; Sargazi, Mansur; Moeenrezakhanlou, Alireza

    In this study, we aimed to determine the significance of association between Tuberculosis and apolipoprotein E polymorphism. The apolipoprotein E genotypes were assayed in 250 tuberculosis patients by polymerase chain reaction followed by enzymatic digestion with Hha I. The results were compared with the results of the same experiments on 250 sex and age matched control peoples. Present results showed that in studied populations, prevalence of E4 genotype was lower in controls than in patients (8 v. 13.2%; OR = 1.75, p<0.05) and prevalence of E3 genotype was high in controls than in patients (86 v.51%; OR = 0.17, p<0.05). Statistically significant difference was found between patients and controls with respect to ɛ2 allele frequencies, while ɛ2 allele frequency was found to be much less prevalent in controls (6%) than in patients (35.8%; OR = 8.72, p<0.05). Also, our study revealed that there is an association between apolipoprotein E genotypes and amplitude to tuberculosis in studied populations. However, large population-based studies are needed to understand the exact role played by the locus in causing the condition.

  13. Direct Transcriptional Effects of Apolipoprotein E

    PubMed Central

    Theendakara, Veena; Peters-Libeu, Clare A.; Spilman, Patricia; Poksay, Karen S.

    2016-01-01

    A major unanswered question in biology and medicine is the mechanism by which the product of the apolipoprotein E ε4 allele, the lipid-binding protein apolipoprotein E4 (ApoE4), plays a pivotal role in processes as disparate as Alzheimer's disease (AD; in which it is the single most important genetic risk factor), atherosclerotic cardiovascular disease, Lewy body dementia, hominid evolution, and inflammation. Using a combination of neural cell lines, skin fibroblasts from AD patients, and ApoE targeted replacement mouse brains, we show in the present report that ApoE4 undergoes nuclear translocation, binds double-stranded DNA with high affinity (low nanomolar), and functions as a transcription factor. Using chromatin immunoprecipitation and high-throughput DNA sequencing, our results indicate that the ApoE4 DNA binding sites include ∼1700 gene promoter regions. The genes associated with these promoters provide new insight into the mechanism by which AD risk is conferred by ApoE4, because they include genes associated with trophic support, programmed cell death, microtubule disassembly, synaptic function, aging, and insulin resistance, all processes that have been implicated in AD pathogenesis. SIGNIFICANCE STATEMENT This study shows for the first time that apolipoprotein E4 binds DNA with high affinity and that its binding sites include 1700 promoter regions that include genes associated with neurotrophins, programmed cell death, synaptic function, sirtuins and aging, and insulin resistance, all processes that have been implicated in Alzheimer's disease pathogenesis. PMID:26791201

  14. The Ai project: historical and ecological contexts.

    PubMed

    Matsuzawa, Tetsuro

    2003-12-01

    This paper aims to review a long-term research project exploring the chimpanzee mind within historical and ecological contexts. The Ai project began in 1978 and was directly inspired by preceding ape-language studies conducted in Western countries. However, in contrast with the latter, it has focused on the perceptual and cognitive capabilities of chimpanzees rather than communicative skills between humans and chimpanzees. In the original setting, a single chimpanzee faced a computer-controlled apparatus and performed various kinds of matching-to-sample discrimination tasks. Questions regarding the chimpanzee mind can be traced back to Wolfgang Koehler's work in the early part of the 20th century. Yet, Japan has its unique natural and cultural background: it is home to an indigenous primate species, the Japanese snow monkey. This fact has contributed to the emergence of two previous projects in the wild led by the late Kinji Imanishi and his students. First, the Koshima monkey project began in 1948 and became famous for its discovery of the cultural propagation of sweet-potato washing behavior. Second, pioneering work in Africa, starting in 1958, aimed to study great apes in their natural habitat. Thanks to the influence of these intellectual ancestors, the present author also undertook the field study of chimpanzees in the wild, focusing on tool manufacture and use. This work has demonstrated the importance of social and ecological perspectives even for the study of the mind. Combining experimental approaches with a field setting, the Ai project continues to explore cognition and behavior in chimpanzees, while its focus has shifted from the study of a single subject toward that of the community as a whole. PMID:14566577

  15. Apolipoprotein A-V is present in bile and its secretion increases with lipid absorption in Sprague-Dawley rats.

    PubMed

    Zhang, Linda S; Sato, Hirokazu; Yang, Qing; Ryan, Robert O; Wang, David Q-H; Howles, Philip N; Tso, Patrick

    2015-12-01

    Apolipoprotein (apo) A-V is a protein synthesized only in the liver that dramatically modulates plasma triglyceride levels. Recent studies suggest a novel role for hepatic apoA-V in regulating the absorption of dietary triglycerides, but its mode of action on the gut remains unknown. The aim of this study was to test for apoA-V in bile and to determine whether its secretion is regulated by dietary lipids. After an overnight recovery, adult male Sprague-Dawley bile fistula rats indeed secreted apoA-V into bile at a constant rate under fasting conditions. An intraduodenal bolus of intralipid (n = 12) increased the biliary secretion of apoA-V but not of other apolipoproteins, such as A-I, A-IV, B, and E. The lipid-induced increase of biliary apoA-V was abolished under conditions of poor lymphatic lipid transport, suggesting that the stimulation is regulated by the magnitude of lipids associated with chylomicrons transported into lymph. We also studied the secretion of apoA-V into bile immediately following bile duct cannulation. Biliary apoA-V increased over time (∼6-fold increase at hour 16, n = 8) but the secretions of other apolipoproteins remained constant. Replenishing luminal phosphatidylcholine and taurocholate (n = 9) only enhanced apoA-V secretion in bile, suggesting that the increase was not due to depletion of phospholipids or bile salts. This is the first study to demonstrate that apoA-V is secreted into bile, introducing a potential route of delivery of hepatic apoA-V to the gut lumen. Our study also reveals the uniqueness of apoA-V secretion into bile that is regulated by mechanisms different from other apolipoproteins. PMID:26505974

  16. JGOMAS: New Approach to AI Teaching

    ERIC Educational Resources Information Center

    Barella, A.; Valero, S.; Carrascosa, C.

    2009-01-01

    This paper presents a new environment for teaching practical work in AI subjects. The main purpose of this environment is to make AI techniques more appealing to students and to facilitate the use of the toolkits which are currently widely used in research and development. This new environment has a toolkit for developing and executing agents,…

  17. Tips to Improve AI Pregnancy Rates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper is aimed at identifying and emphasizing the critical factors that contribute to a successful AI breeding season. Accurate and efficient heat detection is the first step toward achieving AI pregnancies. Electronic estrous detection is not necessary if producers will spend more time observi...

  18. The Relevance of AI Research to CAI.

    ERIC Educational Resources Information Center

    Kearsley, Greg P.

    This article provides a tutorial introduction to Artificial Intelligence (AI) research for those involved in Computer Assisted Instruction (CAI). The general theme is that much of the current work in AI, particularly in the areas of natural language understanding systems, rule induction, programming languages, and socratic systems, has important…

  19. Apolipoprotein A-II is a key regulatory factor of HDL metabolism as appears from studies with transgenic animals and clinical outcomes.

    PubMed

    Maïga, Sira Fatoumata; Kalopissis, Athina-Despina; Chabert, Michèle

    2014-01-01

    The structure and metabolism of HDL are linked to their major apolipoproteins (apo) A-I and A-II. HDL metabolism is very dynamic and depends on the constant remodeling by lipases, lipid transfer proteins and receptors. HDL exert several cardioprotective effects, through their antioxidant and antiinflammatory capacities and through the stimulation of reverse cholesterol transport from extrahepatic tissues to the liver for excretion into bile. HDL also serve as plasma reservoir for C and E apolipoproteins, as transport vehicles for a great variety of proteins, and may have more physiological functions than previously recognized. In this review we will develop several aspects of HDL metabolism with emphasis on the structure/function of apo A-I and apo A-II. An important contribution to our understanding of the respective roles of apo A-I and apo A-II comes from studies using transgenic animal models that highlighted the stabilizatory role of apo A-II on HDL through inhibition of their remodeling by lipases. Clinical studies coupled with proteomic analyses revealed the presence of dysfunctional HDL in patients with cardiovascular disease. Beyond HDL cholesterol, a new notion is the functionality of HDL particles. In spite of abundant literature on HDL metabolic properties, a major question remains unanswered: which HDL particle(s) confer(s) protection against cardiovascular risk? PMID:24012775

  20. Intestinal apolipoprotein synthesis in the newborn piglet.

    PubMed

    Black, D D; Rohwer-Nutter, P L

    1991-01-01

    To determine the effects of dietary and biliary lipid absorption on intestinal apo B-48 and apo A-I synthesis in the newborn piglet, 2-d-old female piglets were prepared with a duodenal infusion catheter. After recovery, animals were given either low triglyceride (Vivonex; VIV group) or high triglyceride (Intralipid; FAT group) diets by continuous intraduodenal infusion for 24 h. A bile-diverted group was also studied. Segments of proximal jejunum and distal ileum were then pulse-radiolabeled in vivo with 3H-leucine. Mucosal apo B-48 and apo A-I were immunoprecipitated, and apoprotein synthesis was expressed as percentage of total protein synthesis. Mucosal apoprotein content (ng apoprotein/microgram total protein) was measured by competitive ELISA assays. In jejunum and ileum, apo B-48 synthesis was not different in the three groups. However, apo B content increased 2.4-fold in jejunum and 1.7-fold in ileum in the FAT group compared with the VIV group. Immunoblotting revealed the majority of jejunal apo B to be apo B-48, not apo B-100 from contaminating plasma lipoproteins, in all three experimental groups. Bile-diverted animals had decreased jejunal apo B content compared with the VIV group. Jejunal apo A-I synthesis and content were approximately 2-fold higher in FAT animals compared with the VIV group. Although ileal apo A-I synthesis was also 2-fold higher in the FAT group, apo A-I content was not different from the VIV group. Neither jejunal nor ileal apo A-I synthesis was significantly affected by bile diversion, even though jejunal apo A-I content was decreased by over two thirds compared with the VIV animals. In the newborn piglet, intestinal synthesis of apo B-48 and apo A-I is differentially regulated by luminal lipid absorption. Although fat feeding and bile diversion regulate mucosal apo B-48 content, synthesis is unchanged, indicating a posttranslational regulatory mechanism.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1900361

  1. Apolipoproteins, lipids and risk of cancer.

    PubMed

    Borgquist, Signe; Butt, Talha; Almgren, Peter; Shiffman, Dov; Stocks, Tanja; Orho-Melander, Marju; Manjer, Jonas; Melander, Olle

    2016-06-01

    The epidemiological evidence for an obesity-cancer association is solid, whereas the association between obesity-associated lipoprotein levels and cancer is less evident. We investigated circulating levels of Apolipoprotein A1 (ApoA1), Apolipoprotein B (ApoB), LDL-cholesterol (LDL-C) and HDL-cholesterol (HDL-C) and association to risk of overall cancer and common cancer forms. The Malmö Diet and Cancer Study, a population-based prospective cohort study, enrolled 17,035 women and 11,063 men (1991-1996). Incident cancer cases were ascertained by record linkage with the Swedish Cancer Registry until end of follow-up, January 1, 2012. Baseline serum levels of ApoA1 and ApoB were analyzed for the entire cohort and HDL-C and LDL-C levels in 5,281 participants. Hazard ratios, with 95% confidence interval, were calculated using Cox's proportional hazards analysis. In the entire cohort, none of the exposures were related to overall cancer risk (HRadj ApoA1 = 0.98, 95%CI: 0.95,1.01; HRadj ApoB = 1.01, 95%CI: 0.98-1.04). Among men, ApoB was positively associated with cancer risk (HRadj ApoB = 1.06, 95%CI: 1.01,1.10). Female breast cancer risk was inversely associated with ApoB (HRadj = 0.92, 95%CI: 0.86,0.99). Among both genders, ApoA1 was inversely associated with lung cancer risk (HRadj = 0.88, 95%CI: 0.80,0.97), whereas high ApoB increased lung cancer risk (HRadj = 1.08, 95%CI: 0.99,1.18). Colorectal cancer risk was increased with high ApoB (HRadj = 1.08, 95%CI: 1.01,1.16) among both genders. Apolipoprotein levels were not associated with prostate cancer incidence. Circulating levels of apolipoproteins are associated with overall cancer risk in men and across both genders with breast, lung and colorectal cancer risk. Validation of these findings may facilitate future primary prevention strategies for cancer. PMID:26804063

  2. The Structure of Dimeric Apolipoprotein A-IV and Its Mechanism of Self-Association

    SciTech Connect

    Deng, Xiaodi; Morris, Jamie; Dressmen, James; Tubb, Matthew R.; Tso, Patrick; Jerome, W. Gray; Davidson, W. Sean; Thompson, Thomas B.

    2012-08-10

    Apolipoproteins are key structural elements of lipoproteins and critical mediators of lipid metabolism. Their detergent-like properties allow them to emulsify lipid or exist in a soluble lipid-free form in various states of self-association. Unfortunately, these traits have hampered high-resolution structural studies needed to understand the biogenesis of cardioprotective high-density lipoproteins (HDLs). We derived a crystal structure of the core domain of human apolipoprotein (apo)A-IV, an HDL component and important mediator of lipid absorption. The structure at 2.4 {angstrom} depicts two linearly connected 4-helix bundles participating in a helix swapping arrangement that offers a clear explanation for how the protein self-associates as well as clues to the structure of its monomeric form. This also provides a logical basis for antiparallel arrangements recently described for lipid-containing particles. Furthermore, we propose a 'swinging door' model for apoA-IV lipid association.

  3. Lipid and apolipoprotein distribution as a function of density in equine plasma lipoprotein.

    PubMed

    Le Goff, D; Pastier, D; Hannan, Y; Petit, E; Ayrault-Jarrier, M; Nouvelot, A

    1989-01-01

    1. Equine lipoproteins were isolated from plasma by density gradient ultracentrifugation and apolipoprotein composition determined by SDS-polyacrylamide gel electrophoresis. 2. VLDL and IDL were present at low concentration (0.2 mg/ml). Two apoB components of Mr corresponding to human apoB-100 and one apoB-48-like component were represented in VLDL fraction. 3. LDL-1 and LDL-2 subfractions have displayed an almost equal concentration (0.4 mg/ml). Two apoB-100-like components were the major apolipoproteins in each fraction. Small amounts of apoB-48-like component were detectable in LDL-1 and LDL-2. 4. HDL-2 represented a major class of equine lipoproteins (1.8 mg/ml). ApoA-1-like component was the dominant protein in HDL-1, HDL-2 and HDL-3. Dimeric apoA-II-like components were slightly represented in HDL subfractions. 5. HDL-3 displayed the same apolipoprotein pattern as HDL-1 and HDL-2, but two further minor proteins of Mr 20,000 and 14,000 were detected. 6. VHDL represented a minor class of lipoprotein (0.2 mg/ml). ApoA-I-like component was the major apolipoprotein of VHDL. Small amounts of apoA-IV-like, apoE-like, and Mr 55,000 protein were detectable. 7. ApoC-like of Mr lower than 10,000 was represented in all equine lipoprotein classes. PMID:2776430

  4. Soya phytoestrogens, genistein and daidzein, decrease apolipoprotein B secretion from HepG2 cells through multiple mechanisms.

    PubMed

    Borradaile, Nica M; de Dreu, Linda E; Wilcox, Lisa J; Edwards, Jane Y; Huff, Murray W

    2002-09-01

    Diets containing the soya-derived phytoestrogens, genistein and daidzein, decrease plasma cholesterol in humans and experimental animals. The mechanisms responsible for the hypocholesterolaemic effects of these isoflavones are unknown. The present study was conducted to determine if genistein and daidzein regulate hepatocyte cholesterol metabolism and apolipoprotein (apo) B secretion in cultured human hepatoma (HepG2) cells. ApoB secretion was decreased dose-dependently by up to 63% and 71% by genistein and daidzein (100 microM; P<0.0001) respectively. In contrast, no effect on apoAI secretion was observed. Cellular cholesterol synthesis was inhibited 41% by genistein (100 microM; P<0.005) and 18% by daidzein (100 microM; P<0.05), which was associated with significant increases in 3-hydroxy-3-methylglutaryl-CoA reductase mRNA. Cellular cholesterol esterification was decreased 56% by genistein (100 microM; P<0.04) and 29% by daidzein (100 microM; P<0.04); however, mRNA levels for acyl-CoA:cholesterol acyltransferase (ACAT) 1 and ACAT2 were unaffected. At 100 microM, both isoflavones equally inhibited the activities of both forms of ACAT in cells transfected with either ACAT1 or ACAT2. Genistein (100 microM) and daidzein (100 microM) significantly decreased the activity of microsomal triacylglycerol transfer protein (MTP) by 30% and 24% respectively, and significantly decreased MTP mRNA levels by 35% and 55%. Both isoflavones increased low-density lipoprotein (LDL)-receptor mRNA levels by 3- to 6-fold (100 microM; P<0.03) and significantly increased the binding, uptake and degradation of (125)I-labelled LDL, suggesting that enhanced reuptake of newly secreted apoB-containing lipoproteins contributed to the net decrease in apoB secretion. These results indicate that genistein and daidzein inhibit hepatocyte apoB secretion through several mechanisms, including inhibition of cholesterol synthesis and esterification, inhibition of MTP activity and expression and

  5. Mapping Fishing Effort through AIS Data.

    PubMed

    Natale, Fabrizio; Gibin, Maurizio; Alessandrini, Alfredo; Vespe, Michele; Paulrud, Anton

    2015-01-01

    Several research initiatives have been undertaken to map fishing effort at high spatial resolution using the Vessel Monitoring System (VMS). An alternative to the VMS is represented by the Automatic Identification System (AIS), which in the EU became compulsory in May 2014 for all fishing vessels of length above 15 meters. The aim of this paper is to assess the uptake of the AIS in the EU fishing fleet and the feasibility of producing a map of fishing effort with high spatial and temporal resolution at European scale. After analysing a large AIS dataset for the period January-August 2014 and covering most of the EU waters, we show that AIS was adopted by around 75% of EU fishing vessels above 15 meters of length. Using the Swedish fleet as a case study, we developed a method to identify fishing activity based on the analysis of individual vessels' speed profiles and produce a high resolution map of fishing effort based on AIS data. The method was validated using detailed logbook data and proved to be sufficiently accurate and computationally efficient to identify fishing grounds and effort in the case of trawlers, which represent the largest portion of the EU fishing fleet above 15 meters of length. Issues still to be addressed before extending the exercise to the entire EU fleet are the assessment of coverage levels of the AIS data for all EU waters and the identification of fishing activity in the case of vessels other than trawlers. PMID:26098430

  6. Mapping Fishing Effort through AIS Data

    PubMed Central

    Natale, Fabrizio; Gibin, Maurizio; Alessandrini, Alfredo; Vespe, Michele; Paulrud, Anton

    2015-01-01

    Several research initiatives have been undertaken to map fishing effort at high spatial resolution using the Vessel Monitoring System (VMS). An alternative to the VMS is represented by the Automatic Identification System (AIS), which in the EU became compulsory in May 2014 for all fishing vessels of length above 15 meters. The aim of this paper is to assess the uptake of the AIS in the EU fishing fleet and the feasibility of producing a map of fishing effort with high spatial and temporal resolution at European scale. After analysing a large AIS dataset for the period January-August 2014 and covering most of the EU waters, we show that AIS was adopted by around 75% of EU fishing vessels above 15 meters of length. Using the Swedish fleet as a case study, we developed a method to identify fishing activity based on the analysis of individual vessels’ speed profiles and produce a high resolution map of fishing effort based on AIS data. The method was validated using detailed logbook data and proved to be sufficiently accurate and computationally efficient to identify fishing grounds and effort in the case of trawlers, which represent the largest portion of the EU fishing fleet above 15 meters of length. Issues still to be addressed before extending the exercise to the entire EU fleet are the assessment of coverage levels of the AIS data for all EU waters and the identification of fishing activity in the case of vessels other than trawlers. PMID:26098430

  7. Pro- and anti-atherogenic effects of a dominant negative P465L mutation of PPARγ in apolipoprotein E-null mice

    PubMed Central

    Pendse, Avani A.; Johnson, Lance A.; Kim, Hyung-Suk; McNair, Marcus; Nipp, C. Taylor; Wilhelm, Carolyn; Maeda, Nobuyo

    2012-01-01

    Objective The dominant-negative mutation, P467L, in Peroxisome Proliferator Activated Receptor gamma (PPARγ) affects adipose tissue distribution, insulin sensitivity and blood pressure in heterozygous humans. We hypothesized that the equivalent mutation, PPARγ-P465L, in mice will worsen atherosclerosis. Methods and Results ApolipoproteinE-null mice with and without PPARγ-P465L mutation were bred in 129S6 inbred genetic background. Mild hypertension and lipodystrophy of PPARγ-P465L persisted in the apoE-null background. Glucose homeostasis was normal, but plasma adiponectin was significantly lower and resistin was higher in PPARγ-P465L mice. Plasma cholesterol and lipoprotein distribution were not different, but plasma triglycerides tended to be reduced. Surprisingly, there were no overall changes in the atherosclerotic plaque size or composition. PPARγ-P465L macrophages had a small decrease in CD-36 mRNA and a small yet significant reduction in VLDL uptake in culture. In unloaded apoE-null macrophages with PPARγ-P465L, cholesterol uptake was reduced while apoAI-mediated efflux was increased. However, when cells were cholesterol loaded in presence of acetylated LDL, no genotype difference in uptake or efflux was apparent. A reduction of VCAM1 expression in aorta suggests a relatively anti-atherogenic vascular environment in mice with PPARγ-P465L. Conclusions Small, competing pro- and anti-atherogenic effects of PPARγ-P465L mutation result in unchanged plaque development in apoE-deficient mice. PMID:22539598

  8. Lysis of Trypanosoma brucei by a toxic subspecies of human high density lipoprotein.

    PubMed

    Hajduk, S L; Moore, D R; Vasudevacharya, J; Siqueira, H; Torri, A F; Tytler, E M; Esko, J D

    1989-03-25

    Trypanosoma brucei brucei is an important pathogen of domestic cattle in sub-Saharan Africa and is closely related to the human sleeping sickness parasites, Trypanosoma brucei gambiense and Trypanosoma brucei rhodesiense. However, T. b. brucei is non-infectious to humans. The restriction of the host range of T. b. brucei results from the sensitivity of the parasite to lysis by toxic human high density lipoproteins (HDL) (Rifkin, M. R. (1978) Proc. Natl. Acad. Sci. U.S.A. 75, 3450-3454). We show in this report that trypanosome lytic activity is not a universal feature of all human HDL particles but rather that it is associated with a minor subclass of HDL. We have purified the lytic activity about 8,000-fold and have identified and characterized the subspecies of HDL responsible for trypanosome lysis. This class of HDL has a relative molecular weight of 490,000, a buoyant density of 1.21-1.24 g/ml, and a particle diameter of 150-210 A. It contains apolipoproteins AI, AII, CI, CII, and CIII, and monoclonal antibodies against apo-AI and apo-AII inhibit trypanocidal activity. In addition to these common apolipoproteins, the particles also contain at least three unique proteins, as measured by sodium dodecyl sulfate-polyacrylamide gel electrophoresis under nonreducing conditions. Treatment of the particles with dithiothreitol resulted in the disappearance of two of the proteins and abolished trypanocidal activity. Two-dimensional gel electrophoresis showed that these proteins were a disulfide-linked trimer of 45,000, 36,000, and 13,500-Da polypeptides and dimers of the 36,000- and 13,500-Da polypeptides or of 65,000- and 8,500-Da polypeptides. Studies on the lysis of T. b. brucei by the purified particle suggest that the lytic pathway may involve the uptake of the trypanocidal subspecies of HDL by endocytosis. PMID:2494183

  9. Peroxisome Proliferator-Activated Receptorα Agonists Differentially Regulate Inhibitor of DNA Binding Expression in Rodents and Human Cells

    PubMed Central

    González, María del Carmen; Corton, J. Christopher; Acero, Nuria; Muñoz-Mingarro, Dolores; Quirós, Yolanda; Álvarez-Millán, Juan José; Herrera, Emilio; Bocos, Carlos

    2012-01-01

    Inhibitor of DNA binding (Id2) is a helix-loop-helix (HLH) transcription factor that participates in cell differentiation and proliferation. Id2 has been linked to the development of cardiovascular diseases since thiazolidinediones, antidiabetic agents and peroxisome proliferator-activated receptor (PPAR) gamma agonists, have been reported to diminish Id2 expression in human cells. We hypothesized that PPARα activators may also alter Id2 expression. Fenofibrate diminished hepatic Id2 expression in both late pregnant and unmated rats. In 24 hour fasted rats, Id2 expression was decreased under conditions known to activate PPARα. In order to determine whether the fibrate effects were mediated by PPARα, wild-type mice and PPARα-null mice were treated with Wy-14,643 (WY). WY reduced Id2 expression in wild-type mice without an effect in PPARα-null mice. In contrast, fenofibrate induced Id2 expression after 24 hours of treatment in human hepatocarcinoma cells (HepG2). MK-886, a PPARα antagonist, did not block fenofibrate-induced activation of Id2 expression, suggesting a PPARα-independent effect was involved. These findings confirm that Id2 is a gene responsive to PPARα agonists. Like other genes (apolipoprotein A-I, apolipoprotein A-V), the opposite directional transcriptional effect in rodents and a human cell line further emphasizes that PPARα agonists have different effects in rodents and humans. PMID:22701468

  10. Peroxisome proliferator-activated receptorα agonists differentially regulate inhibitor of DNA binding expression in rodents and human cells.

    PubMed

    González, María Del Carmen; Corton, J Christopher; Acero, Nuria; Muñoz-Mingarro, Dolores; Quirós, Yolanda; Alvarez-Millán, Juan José; Herrera, Emilio; Bocos, Carlos

    2012-01-01

    Inhibitor of DNA binding (Id2) is a helix-loop-helix (HLH) transcription factor that participates in cell differentiation and proliferation. Id2 has been linked to the development of cardiovascular diseases since thiazolidinediones, antidiabetic agents and peroxisome proliferator-activated receptor (PPAR) gamma agonists, have been reported to diminish Id2 expression in human cells. We hypothesized that PPARα activators may also alter Id2 expression. Fenofibrate diminished hepatic Id2 expression in both late pregnant and unmated rats. In 24 hour fasted rats, Id2 expression was decreased under conditions known to activate PPARα. In order to determine whether the fibrate effects were mediated by PPARα, wild-type mice and PPARα-null mice were treated with Wy-14,643 (WY). WY reduced Id2 expression in wild-type mice without an effect in PPARα-null mice. In contrast, fenofibrate induced Id2 expression after 24 hours of treatment in human hepatocarcinoma cells (HepG2). MK-886, a PPARα antagonist, did not block fenofibrate-induced activation of Id2 expression, suggesting a PPARα-independent effect was involved. These findings confirm that Id2 is a gene responsive to PPARα agonists. Like other genes (apolipoprotein A-I, apolipoprotein A-V), the opposite directional transcriptional effect in rodents and a human cell line further emphasizes that PPARα agonists have different effects in rodents and humans. PMID:22701468

  11. Metabolism of lipoproteins containing apolipoprotein B-100 in blood plasma of rabbits: heterogeneity related to the presence of apolipoprotein E.

    PubMed Central

    Yamada, N; Shames, D M; Stoudemire, J B; Havel, R J

    1986-01-01

    Apolipoprotein B-100 is a constant component of very low density lipoproteins (VLDL), intermediate density lipoproteins (IDL), and low density lipoproteins (LDL) in mammalian blood plasma. We have found that each of these classes of lipoproteins includes particles that contain apolipoprotein E (B,E particles) as well as particles that lack this protein (B particles). These two species can be separated by immunosorption on columns of anti-apolipoprotein E bound to Sepharose. We have injected radioiodinated VLDL, IDL, and LDL intravenously into recipient rabbits and have determined the concentration of radioiodine in apolipoprotein B-100 in B,E and B particles in whole-blood plasma obtained at intervals for 24 hr. We have developed a multicompartmental model that is consistent with this new information and with current concepts of lipoprotein metabolism. The model indicates that all apolipoprotein B-100 enters the blood as VLDL, of which about 90% is in B,E particles. Most VLDL B,E particles are removed rapidly from the blood, and only a small fraction is converted to IDL and eventually to LDL (overall conversion is approximately 2%). By contrast, a much smaller fraction of VLDL B particles is removed directly, and approximately 27% is converted to LDL. In addition, some B,E particles are converted to B particles as VLDL are converted to LDL, so that most LDL particles lack apolipoprotein E. Fractional rates of irreversible removal of B,E and B particles in IDL and LDL are similar. Our results indicate that the presence of apolipoprotein E is a major determinant of the metabolic fate of VLDL particles and support the hypothesis that polyvalent binding of particles containing several molecules of apolipoprotein E promotes receptor-dependent endocytosis of hepatogenous lipoproteins and limits their conversion to lipoproteins of higher density. PMID:3458191

  12. Francisella tularensis subsp. tularensis Group A.I, United States

    PubMed Central

    Birdsell, Dawn N.; Johansson, Anders; Öhrman, Caroline; Kaufman, Emily; Molins, Claudia; Pearson, Talima; Gyuranecz, Miklós; Naumann, Amber; Vogler, Amy J.; Myrtennäs, Kerstin; Larsson, Pär; Forsman, Mats; Sjödin, Andreas; Gillece, John D.; Schupp, James; Petersen, Jeannine M.; Keim, Paul

    2014-01-01

    We used whole-genome analysis and subsequent characterization of geographically diverse strains using new genetic signatures to identify distinct subgroups within Francisella tularensis subsp. tularensis group A.I: A.I.3, A.I.8, and A.I.12. These subgroups exhibit complex phylogeographic patterns within North America. The widest distribution was observed for A.I.12, which suggests an adaptive advantage. PMID:24755401

  13. Cell-free Co-expression of Functional Membrane Proteins and Apolipoprotein, Forming Soluble Nanolipoprotein Particles*S⃞

    PubMed Central

    Cappuccio, Jenny A.; Blanchette, Craig D.; Sulchek, Todd A.; Arroyo, Erin S.; Kralj, Joel M.; Hinz, Angela K.; Kuhn, Edward A.; Chromy, Brett A.; Segelke, Brent W.; Rothschild, Kenneth J.; Fletcher, Julia E.; Katzen, Federico; Peterson, Todd C.; Kudlicki, Wieslaw A.; Bench, Graham; Hoeprich, Paul D.; Coleman, Matthew A.

    2008-01-01

    Here we demonstrate rapid production of solubilized and functional membrane protein by simultaneous cell-free expression of an apolipoprotein and a membrane protein in the presence of lipids, leading to the self-assembly of membrane protein-containing nanolipoprotein particles (NLPs). NLPs have shown great promise as a biotechnology platform for solubilizing and characterizing membrane proteins. However, current approaches are limited because they require extensive efforts to express, purify, and solubilize the membrane protein prior to insertion into NLPs. By the simple addition of a few constituents to cell-free extracts, we can produce membrane proteins in NLPs with considerably less effort. For this approach an integral membrane protein and an apolipoprotein scaffold are encoded by two DNA plasmids introduced into cell-free extracts along with lipids. For this study reported here we used plasmids encoding the bacteriorhodopsin (bR) membrane apoprotein and scaffold protein Δ1–49 apolipoprotein A-I fragment (Δ49A1). Cell free co-expression of the proteins encoded by these plasmids, in the presence of the cofactor all-trans-retinal and dimyristoylphosphatidylcholine, resulted in production of functional bR as demonstrated by a 5-nm shift in the absorption spectra upon light adaptation and characteristic time-resolved FT infrared difference spectra for the bR → M transition. Importantly the functional bR was solubilized in discoidal bR·NLPs as determined by atomic force microscopy. A survey study of other membrane proteins co-expressed with Δ49A1 scaffold protein also showed significantly increased solubility of all of the membrane proteins, indicating that this approach may provide a general method for expressing membrane proteins enabling further studies. PMID:18603642

  14. Data on gene and protein expression changes induced by apabetalone (RVX-208) in ex vivo treated human whole blood and primary hepatocytes.

    PubMed

    Wasiak, Sylwia; Gilham, Dean; Tsujikawa, Laura M; Halliday, Christopher; Norek, Karen; Patel, Reena G; McLure, Kevin G; Young, Peter R; Gordon, Allan; Kulikowski, Ewelina; Johansson, Jan; Sweeney, Michael; Wong, Norman C

    2016-09-01

    Apabetalone (RVX-208) inhibits the interaction between epigenetic regulators known as bromodomain and extraterminal (BET) proteins and acetyl-lysine marks on histone tails. Data presented here supports the manuscript published in Atherosclerosis "RVX-208, a BET-inhibitor for Treating Atherosclerotic Cardiovascular Disease, Raises ApoA-I/HDL and Represses Pathways that Contribute to Cardiovascular Disease" (Gilham et al., 2016) [1]. It shows that RVX-208 and a comparator BET inhibitor (BETi) JQ1 increase mRNA expression and production of apolipoprotein A-I (ApoA-I), the main protein component of high density lipoproteins, in primary human and African green monkey hepatocytes. In addition, reported here are gene expression changes from a microarray-based analysis of human whole blood and of primary human hepatocytes treated with RVX-208. PMID:27570805

  15. Comparison of AIS 1990 update 98 versus AIS 2005 for describing PMHS injuries in lateral and oblique sled tests

    PubMed Central

    Yoganandan, Narayan; Pintar, Frank A.; Humm, John R.; Stadter, Gregory W.; Curry, William H.; Brasel, Karen J.

    2013-01-01

    This study analyzed skeletal and organ injuries in pure lateral and oblique impacts from 20 intact post mortem human surrogate (PMHS) sled tests at 6.7 m/s. Injuries to the shoulder, thorax, abdomen, pelvis and spine were scored using AIS 1990–1998 update and 2005. The Injury Severity Scores (ISS) were extracted for both loadings from both versions. Mean age, stature, total body mass and body mass index for pure lateral and oblique tests: 58 and 55 years, 1.7 and 1.8 m, 69 and 66 kg, and 24 and 21 kg/m2. Skeletal injuries (ribs, sternum) occurred in both impacts. However, oblique impacts resulted in more injuries. Pure lateral and oblique impacts ISS: 0 to 16 and 0 to 24, representing a greater potential for injury-related consequences in real-world situations in oblique impacts. Internal organs were more involved in oblique impacts. ISS decreased in AIS 2005, reflecting changes to scoring and drawing attention to potential effects for pre-hospital care/medical aspects. Mean AIS scores for the two load vectors and two AIS coding schemes are included. From automotive crashworthiness perspectives, decreases in injury severities might alter injury risk functions with a shift to lower metrics for the same risk level than current risk estimations. This finding influences dummy-based injury criteria and occupant safety as risk functions are used for countermeasure effectiveness and cost-benefit analyses by regulatory bodies. Increase in organ injuries in oblique loading indicate the importance of this vector as current dummies and injury criteria used in regulations are based on pure lateral impact data. PMID:24406958

  16. Comparison of AIS 1990 update 98 versus AIS 2005 for describing PMHS injuries in lateral and oblique sled tests.

    PubMed

    Yoganandan, Narayan; Pintar, Frank A; Humm, John R; Stadter, Gregory W; Curry, William H; Brasel, Karen J

    2013-01-01

    This study analyzed skeletal and organ injuries in pure lateral and oblique impacts from 20 intact post mortem human surrogate (PMHS) sled tests at 6.7 m/s. Injuries to the shoulder, thorax, abdomen, pelvis and spine were scored using AIS 1990-1998 update and 2005. The Injury Severity Scores (ISS) were extracted for both loadings from both versions. Mean age, stature, total body mass and body mass index for pure lateral and oblique tests: 58 and 55 years, 1.7 and 1.8 m, 69 and 66 kg, and 24 and 21 kg/m(2). Skeletal injuries (ribs, sternum) occurred in both impacts. However, oblique impacts resulted in more injuries. Pure lateral and oblique impacts ISS: 0 to 16 and 0 to 24, representing a greater potential for injury-related consequences in real-world situations in oblique impacts. Internal organs were more involved in oblique impacts. ISS decreased in AIS 2005, reflecting changes to scoring and drawing attention to potential effects for pre-hospital care/medical aspects. Mean AIS scores for the two load vectors and two AIS coding schemes are included. From automotive crashworthiness perspectives, decreases in injury severities might alter injury risk functions with a shift to lower metrics for the same risk level than current risk estimations. This finding influences dummy-based injury criteria and occupant safety as risk functions are used for countermeasure effectiveness and cost-benefit analyses by regulatory bodies. Increase in organ injuries in oblique loading indicate the importance of this vector as current dummies and injury criteria used in regulations are based on pure lateral impact data. PMID:24406958

  17. The potential applications of Apolipoprotein E in personalized medicine

    PubMed Central

    Villeneuve, Sylvia; Brisson, Diane; Marchant, Natalie L.; Gaudet, Daniel

    2014-01-01

    Personalized medicine uses various individual characteristics to guide medical decisions. Apolipoprotein (ApoE), the most studied polymorphism in humans, has been associated with several diseases. The purpose of this review is to elucidate the potential role of ApoE polymorphisms in personalized medicine, with a specific focus on neurodegenerative diseases, by giving an overview of its influence on disease risk assessment, diagnosis, prognosis, and therapy. This review is not a systematic inventory of the literature, but rather a summary and discussion of novel, influential and promising works in the field of ApoE research that could be valuable for personalized medicine. Empirical evidence suggests that ApoE genotype informs pre-symptomatic risk for a wide variety of diseases, is valuable for the diagnosis of type III dysbetalipoproteinemia, increases risk of dementia in neurodegenerative diseases, and is associated with a poor prognosis following acute brain damage. ApoE status appears to influence the efficacy of certain drugs, outcome of clinical trials, and might also give insight into disease prevention. Assessing ApoE genotype might therefore help to guide medical decisions in clinical practice. PMID:25071563

  18. Glucose Regulates the Expression of the Apolipoprotein A5 Gene

    SciTech Connect

    Fruchart, Jamila; Nowak, Maxime; Helleboid-Chapman, Audrey; Jakel, Heidelinde; Moitrot, Emmanuelle; Rommens, Corinne; Pennacchio, Len A.; Fruchart-Najib, Jamila; Fruchart, Jean-Charles

    2008-04-07

    The apolipoprotein A5 gene (APOA5) is a key player in determining triglyceride concentrations in humans and mice. Since diabetes is often associated with hypertriglyceridemia, this study explores whether APOA5 gene expression is regulated by alteration in glucose homeostasis and the related pathways. D-glucose activates APOA5 gene expression in a time- and dose-dependent manner in hepatocytes, and the glycolytic pathway involved was determined using D-glucose analogs and metabolites. Together, transient transfections, electrophoretic mobility shift assays and chromatin immunoprecipitation assays show that this regulation occurs at the transcriptional level through an increase of USF1/2 binding to an E-box in the APOA5 promoter. We show that this phenomenon is not due to an increase of mRNA or protein expression levels of USF. Using protein phosphatases 1 and 2A inhibitor, we demonstrate that D-glucose regulates APOA5 gene via a dephosphorylation mechanism, thereby resulting in an enhanced USF1/2-promoter binding. Last, subsequent suppressions of USF1/2 and phosphatases mRNA through siRNA gene silencing abolished the regulation. We demonstrate that APOA5 gene is up regulated by D-glucose and USF through phosphatase activation. These findings may provide a new cross talk between glucose and lipid metabolism.

  19. Hepatic sortilin regulates both apolipoprotein B secretion and LDL catabolism

    PubMed Central

    Strong, Alanna; Ding, Qiurong; Edmondson, Andrew C.; Millar, John S.; Sachs, Katherine V.; Li, Xiaoyu; Kumaravel, Arthi; Wang, Margaret Ye; Ai, Ding; Guo, Liang; Alexander, Eric T.; Nguyen, David; Lund-Katz, Sissel; Phillips, Michael C.; Morales, Carlos R.; Tall, Alan R.; Kathiresan, Sekar; Fisher, Edward A.; Musunuru, Kiran; Rader, Daniel J.

    2012-01-01

    Genome-wide association studies (GWAS) have identified a genetic variant at a locus on chromosome 1p13 that is associated with reduced risk of myocardial infarction, reduced plasma levels of LDL cholesterol (LDL-C), and markedly increased expression of the gene sortilin-1 (SORT1) in liver. Sortilin is a lysosomal sorting protein that binds ligands both in the Golgi apparatus and at the plasma membrane and traffics them to the lysosome. We previously reported that increased hepatic sortilin expression in mice reduced plasma LDL-C levels. Here we show that increased hepatic sortilin not only reduced hepatic apolipoprotein B (APOB) secretion, but also increased LDL catabolism, and that both effects were dependent on intact lysosomal targeting. Loss-of-function studies demonstrated that sortilin serves as a bona fide receptor for LDL in vivo in mice. Our data are consistent with a model in which increased hepatic sortilin binds intracellular APOB-containing particles in the Golgi apparatus as well as extracellular LDL at the plasma membrane and traffics them to the lysosome for degradation. We thus provide functional evidence that genetically increased hepatic sortilin expression both reduces hepatic APOB secretion and increases LDL catabolism, providing dual mechanisms for the very strong association between increased hepatic sortilin expression and reduced plasma LDL-C levels in humans. PMID:22751103

  20. [Prognostic value of apolipoproteins A and B in the clinical course of patients with chronic kidney disease previous to dialysis].

    PubMed

    Cerezo, I; Fernández, N; Romero, B; Fernández-Carbonero, E; Hernández-Gallego, R; Caravaca, F

    2009-01-01

    Dyslipidemia is a well-established risk factor for cardiovascular diseases in the general population. However, this association is not observed in chronic kidney disease (CKD) patients. This study examines the association between lipid levels, including apolipoproteins A-I and B concentrations, and all-cause mortality or the development of new cardiovascular events in advanced CKD patients not yet on dialysis. This observational prospective historical study included 331 patients with CKD stage 4 or 5 not yet on dialysis. In addition to conventional clinical and biochemical data, total cholesterol, triglycerides, HDL, LDL, apolipoprotein A-I (apo A) and B (apo B) plasma concentrations were measured. Cox proportional hazard models were adjusted for age, sex, comorbidity index, residual renal function, serum albumin, C-reactive protein levels, and treatment with statins. The median follow-up time was 985 days, and during this period 105 patients died and 54 patients had a new cardiovascular event. In fully-adjusted fixed-covariate Cox models, the hazard ratio for each 10 mg/dl increase of apo A concentration was 0.915 (C.I. 95% 0.844 to 0.992; p=0,031). Patients with an apo A /apo B ratio in the upper tertile (i.e. > 1.42) had a better survival than that of the rest of study patients (hazard ratio = 0.592, C.I. 95% 0.368 to 0.953, p<0.05). None of the study lipid parameters was associated with new cardiovascular events in the adjusted models. In conclusion, apo A concentrations and high apo A / apo B ratios added independent predictive information about survival of CKD patients not yet on dialysis. PMID:19935998

  1. Comparison of timed AI after synchronized ovulation to AI at estrus: reproductive and economic considerations.

    PubMed

    Tenhagen, B A; Drillich, M; Surholt, R; Heuwieser, W

    2004-01-01

    A timed artificial insemination (TAI) protocol using OvSynch was compared to artificial insemination (AI) at detected estrus in 2 large dairy herds differing in reproductive management. Cows were synchronized for TAI starting at 62 and 42 d in milk in herds 1 and 2, respectively. The OvSynch regimen included: GnRH (buserelin) at 0.02 mg (i.m.) on d 0; PGF2alpha (tiaprost) at 0.75 mg (i.m.) on d 7; buserelin at 0.02 mg (i.m.) on d 9; and TAI 16 to 20 h later. After TAI, cows seen in estrus received AI, whereas cows diagnosed not pregnant were resynchronized for TAI. Control cows received AI based on detected estrus after voluntary waiting periods of 72 d in herd 1 and 50 d in herd 2. An economic analysis included costs associated with days open, culling, AI, synchrony products, treatment, and examinations. A sensitivity analysis of those variables determined effects on total costs per pregnancy. Use of OvSynch reduced intervals to first AI and days open in both herds and reduced culling for infertility in herd 2. Conception rates for first AI at detected estrus were significantly higher compared to TAI in both herds and for overall AI at estrus in herd 2. For groups assigned to AI at estrus, mean 21-d submission rates over 200 d for AI were higher in herd 1 than in herd 2 (55.6 vs. 28.6%). Days open and culling were the major cost factors. Although OvSynch improved reproduction in both herds, AI based on detected estrus was economically superior in herd 1, whereas OvSynch was superior in herd 2. This was consistent across ranges of cost factors evaluated. Evaluation of synchrony protocols should include reproductive performance along with appropriate costs associated with treatments. Such costs may offset benefits to reproduction in herds with good estrous detection rates. PMID:14765814

  2. Activated-Ion ETD (AI-ETD) Improves the Ability of ETD to Identify Peptides in a Complex Mixture

    PubMed Central

    Ledvina, Aaron R.; Beauchene, Nicole A.; McAlister, Graeme C.; Syka, John E. P.; Schwartz, Jae C.; Griep-Raming, Jens; Westphall, Michael S.; Coon, Joshua J.

    2010-01-01

    Using a modified ETD-enabled QLT mass spectrometer, we demonstrate the utility of IR activation concomitant with ETD ion-ion reactions (activated-ion ETD, AI-ETD). Analyzing 12 SCX fractions of a LysC digest of human cells (HS) using ETD, CAD, and AI-ETD, we find that AI-ETD generates 13,405 peptide spectral matches (PSMs) at a 1% false-discovery rate (1% FDR), surpassing both ETD (7,968) and CAD (10,904). We also analyze 12 SCX fractions of a tryptic HS digest and find that ETD produces 6,234 PSMs, AI-ETD 9,130 PSMs, and CAD 15,209 PSMs. Compared to ETcaD, AI-ETD generates ~80% more PSMs for tryptic whole cell lysate and ~50% more PSMs for LysC whole cell lysate. PMID:21062032

  3. Apolipoprotein E: from lipid transport to neurobiology

    PubMed Central

    Hauser, Paul S.; Narayanaswami, Vasanthy; Ryan, Robert O.

    2010-01-01

    Apolipoprotein (apo) E has a storied history as a lipid transport protein. The integral association between cholesterol homeostasis and lipoprotein clearance from circulation are intimately related to apoE's function as a ligand for cell surface receptors of the low density lipoprotein receptor family. The receptor binding properties of apoE are strongly influenced by isoform specific amino acid differences as well as the lipidation state of the protein. As understanding of apoE as a structural component of circulating plasma lipoproteins has evolved, exciting developments in neurobiology have revitalized interest in apoE. The strong and enduring correlation between the apoE4 isoform and age of onset and increased risk of Alzheimer's disease has catapulted apoE to the forefront of neurobiology. Using genetic tools generated for study of apoE lipoprotein metabolism, transgenic “knock-in” and gene-disrupted mice are now favored models for study of its role in a variety of neurodegenerative diseases. Key structural knowledge of apoE and isoform specific differences is driving research activity designed to elucidate how a single amino acid change can manifest such profoundly significant pathological consequences. This review describes apoE through a lens of structure-based knowledge that leads to hypotheses that attempt to explain the functions of apoE and isoform specific effects relating to disease mechanism. PMID:20854843

  4. Purification and Characterization of BmooAi: A New Toxin from Bothrops moojeni Snake Venom That Inhibits Platelet Aggregation

    PubMed Central

    Ribeiro de Queiroz, Mayara; Mamede, Carla Cristine N.; de Morais, Nadia Cristina G.; Cortes Fonseca, Kelly; Barbosa de Sousa, Bruna; Migliorini, Thaís M.; Pereira, Déborah Fernanda C.; Stanziola, Leonilda; Calderon, Leonardo A.; Simões-Silva, Rodrigo; Martins Soares, Andreimar; de Oliveira, Fábio

    2014-01-01

    In this paper, we describe the purification/characterization of BmooAi, a new toxin from Bothrops moojeni that inhibits platelet aggregation. The purification of BmooAi was carried out through three chromatographic steps (ion-exchange on a DEAE-Sephacel column, molecular exclusion on a Sephadex G-75 column, and reverse-phase HPLC chromatography on a C2/C18 column). BmooAi was homogeneous by SDS-PAGE and shown to be a single-chain protein of 15,000 Da. BmooAi was analysed by MALDI-TOF Spectrometry and revealed two major components with molecular masses 7824.4 and 7409.2 as well as a trace of protein with a molecular mass of 15,237.4 Da. Sequencing of BmooAi by Edman degradation showed two amino acid sequences: IRDFDPLTNAPENTA and ETEEGAEEGTQ, which revealed no homology to any known toxin from snake venom. BmooAi showed a rather specific inhibitory effect on platelet aggregation induced by collagen, adenosine diphosphate, or epinephrine in human platelet-rich plasma in a dose-dependent manner, whereas it had little or no effect on platelet aggregation induced by ristocetin. The effect on platelet aggregation induced by BmooAi remained active even when heated to 100°C. BmooAi could be of medical interest as a new tool for the development of novel therapeutic agents for the prevention and treatment of thrombotic disorders. PMID:24971359

  5. Targeted Proteomics Identifies Paraoxonase/Arylesterase 1 (PON1) and Apolipoprotein Cs as Potential Risk Factors for Hypoalphalipoproteinemia in Diabetic Subjects Treated with Fenofibrate and Rosiglitazone.

    PubMed

    Ronsein, Graziella E; Reyes-Soffer, Gissette; He, Yi; Oda, Michael; Ginsberg, Henry; Heinecke, Jay W

    2016-03-01

    Low levels of high-density lipoprotein cholesterol (HDL-C) and high triglyceride levels contribute to the excess rate of cardiovascular events seen in subjects with type 2 diabetes. Fenofibrate treatment partially reverses dyslipidemia in these subjects. However, a paradoxical marked reduction in HDL-C and HDL's major protein, apolipoprotein A-I, is a complication of fenofibrate in combination with rosiglitazone, an insulin-sensitizing agent. Risk factors for this condition, termed hypoalphalipoproteinemia, have yet to be identified. Using a case-control study design with subjects enrolled in the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial, we tested the hypothesis that alterations in HDL's protein cargo predispose diabetic subjects to fenofibrate/rosiglitazone-induced hypoalphalipoproteinemia. HDL was isolated from blood obtained from controls (no decreases or increase in HDL-C while receiving fenofibrate/rosiglitazone therapy) and cases (developed hypoalphalipoproteinemia after fenofibrate/rosiglitazone treatment) participating in the ACCORD study before they began fenofibrate/rosiglitazone treatment. HDL proteins were quantified by targeted parallel reaction monitoring (PRM) and selected reaction monitoring (SRM) with isotope dilution. This approach demonstrated marked increases in the relative concentrations of paraoxonase/arylesterase 1 (PON1), apolipoprotein C-II (APOC2), apolipoprotein C-I, and apolipoprotein H in the HDL of subjects who developed hypoalphalipoproteinemia. The case and control subjects did not differ significantly in baseline HDL-C levels or other traditional lipid risk factors. We used orthogonal biochemical techniques to confirm increased levels of PON1 and APOC2. Our observations suggest that an imbalance in HDL proteins predisposes diabetic subjects to develop hypoalphalipoproteinemia on fenofibrate/rosiglitazone therapy. PMID:26667175

  6. Molecular crowding impacts the structure of apolipoprotein A-I with potential implications on in vivo metabolism and function.

    PubMed

    Petrlova, Jitka; Hilt, Silvia; Budamagunta, Madhu; Domingo-Espín, Joan; Voss, John C; Lagerstedt, Jens O

    2016-10-01

    The effect molecular crowding, defined as the volume exclusion exerted by one soluble inert molecule upon another soluble molecule, has on the structure and self-interaction of lipid-free apoA-I were explored. The influence of molecular crowding on lipid-free apoA-I oligomerization and internal dynamics has been analyzed using electron paramagnetic resonance (EPR) spectroscopy measurements of nitroxide spin label at selected positions throughout the protein sequence and at varying concentrations of the crowding agent Ficoll-70. The targeted positions include sites previously shown to be sensitive for detecting intermolecular interaction via spin-spin coupling. Circular dichroism was used to study secondary structural changes in lipid-free apoA-I imposed by increasing concentrations of the crowding agent. Crosslinking and SDS-PAGE gel analysis was employed to further characterize the role molecular crowding plays in inducing apoA-I oligomerization. It was concluded that the dynamic apoA-I structure and oligomeric state was altered in the presence of the crowding agent. It was also found that the C-terminal was slightly more sensitive to molecular crowding. Finally, the data described the region around residue 217 in the C-terminal domain of apoA-I as the most sensitive reporter of the crowding-induced self-association of apoA-I. The implications of this behavior to in vivo functionality are discussed. © 2016 Wiley Periodicals, Inc. Biopolymers 105: 683-692, 2016. PMID:27122373

  7. In vivo efficacy of HDL-like nanolipid particles containing multivalent peptide mimetics of apolipoprotein A-I.

    PubMed

    Zhao, Yannan; Black, Audrey S; Bonnet, David J; Maryanoff, Bruce E; Curtiss, Linda K; Leman, Luke J; Ghadiri, M Reza

    2014-10-01

    We have observed that molecular constructs based on multiple apoA-I mimetic peptides attached to a branched scaffold display promising anti-atherosclerosis functions in vitro. Building on these promising results, we now describe chronic in vivo studies to assess anti-atherosclerotic efficacy of HDL-like nanoparticles assembled from a trimeric construct, administered over 10 weeks either ip or orally to LDL receptor-null mice. When dosed ip, the trimer-based nanolipids markedly reduced plasma LDL-cholesterol levels by 40%, unlike many other apoA-I mimetic peptides, and were substantially atheroprotective. Surprisingly, these nanoparticles were also effective when administered orally at a dose of 75 mg/kg, despite the peptide construct being composed of l-amino acids and being undetectable in the plasma. The orally administered nanoparticles reduced whole aorta lesion areas by 55% and aortic sinus lesion volumes by 71%. Reductions in plasma cholesterol were due to the loss of non-HDL lipoproteins, while plasma HDL-cholesterol levels were increased. At a 10-fold lower oral dose, the nanoparticles were marginally effective in reducing atherosclerotic lesions. Intriguingly, analogous results were obtained with nanolipids of the corresponding monomeric peptide. These nanolipid formulations provide an avenue for developing orally efficacious therapeutic agents to manage atherosclerosis. PMID:24975585

  8. Quercetin represses apolipoprotein B expression by inhibiting the transcriptional activity of C/EBPβ.

    PubMed

    Shimizu, Makoto; Li, Juan; Inoue, Jun; Sato, Ryuichiro

    2015-01-01

    Quercetin is one of the most abundant polyphenolic flavonoids found in fruits and vegetables and has anti-oxidative and anti-obesity effects. Because the small intestine is a major absorptive organ of dietary nutrients, it is likely that highly concentrated food constituents, including polyphenols, are present in the small intestinal epithelial cells, suggesting that food factors may have a profound effect in this tissue. To identify novel targets of quercetin in the intestinal enterocytes, mRNA profiling using human intestinal epithelial Caco-2 cells was performed. We found that mRNA levels of some apolipoproteins, particularly apolipoprotein B (apoB), are downregulated in the presence of quercetin. On the exposure of Caco-2 cells to quercetin, both mRNA and protein levels of apoB were decreased. Promoter analysis of the human apoB revealed that quercetin response element is localized at the 5'-proximal promoter region, which contains a conserved CCAAT enhancer-binding protein (C/EBP)-response element. We found that quercetin reduces the promoter activity of apoB, driven by the enforced expression of C/EBPβ. Quercetin had no effect on either mRNA or protein levels of C/EBPβ. In contrast, we found that quercetin inhibits the transcriptional activity of C/EBPβ but not its recruitment to the apoB promoter. On the exposure of Caco-2 cells to quercetin 3-O-glucuronide, which is in a cell-impermeable form, no notable change in apoB mRNA was observed, suggesting an intracellular action of quercetin. In vitro interaction experiments using quercetin-conjugated beads revealed that quercetin binds to C/EBPβ. Our results describe a novel regulatory mechanism of transcription of apolipoprotein genes by quercetin in the intestinal enterocytes. PMID:25875015

  9. Destriping AIS data using Fourier filtering techniques

    NASA Technical Reports Server (NTRS)

    Hlavka, C.

    1986-01-01

    Airborne Imaging Spectrometers (AIS) data collected in 1984 and 1985 showed pronounced striping in the vertical and horizontal directions. This striping reduced the signal to noise ratio so that features of the spectra of forest canopies were obscured or altered by noise. This noise was removed by application of a notch filter to the Fourier transform of the imagery in each waveband.

  10. AI-2 Quorum Sensing in Campylobacter jejuni

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Quorum sensing response modulates many physiological attributes, such as bacterial virulence/pathogenesis, competence, and biofilm formation, when the bacterial population has reached a certain threshold. Among the various signaling compounds, autoinducer-2 (AI-2) is produced by most bacterial spec...

  11. SNAP and AI Fuel Summary Report

    SciTech Connect

    Lords, R.E.

    1994-08-01

    The SNAP and AI Fuel Summary Report provides a detailed overview of treatment and storage of these fuels from fabrication through current storage including design parameters and reactor history. Chemical and physical characteristics are described, and potential indicators of as-stored fuel conditions are emphasized.

  12. Apolipoprotein E isoform-specific effects on lipoprotein receptor processing

    PubMed Central

    Bachmeier, Corbin; Shackleton, Ben; Ojo, Joseph; Paris, Daniel; Mullan, Michael; Crawford, Fiona

    2014-01-01

    Recent findings indicate an isoform-specific role for apolipoprotein E (apoE) in the elimination of beta-amyloid (Aβ) from the brain. ApoE is closely associated with various lipoprotein receptors, which contribute to Aβ brain removal via metabolic clearance or transit across the blood-brain barrier (BBB). These receptors are subject to ectodomain shedding at the cell surface, which alters endocytic transport and mitigates Aβ elimination. To further understand the manner in which apoE influences Aβ brain clearance, these studies investigated the effect of apoE on lipoprotein receptor shedding. Consistent with prior reports, we observed an increased shedding of the low density lipoprotein receptor (LDLR) and the LDLR-related protein 1 (LRP1) following Aβ exposure in human brain endothelial cells. When Aβ was co-treated with each apoE isoform, there was a reduction in Aβ-induced shedding with apoE2 and apoE3, while lipoprotein receptor shedding in the presence of apoE4 remained elevated. Likewise, intracranial administration of Aβ to apoE targeted replacement mice (expressing the human apoE isoforms) resulted in an isoform-dependent effect on lipoprotein receptor shedding in the brain (apoE4>apoE3>apoE2). Moreover, these results show a strong inverse correlation with our prior work in apoE transgenic mice in which apoE4 animals showed reduced Aβ clearance across the BBB compared to apoE3 animals. Based on these results, apoE4 appears less efficient than other apoE isoforms in regulating lipoprotein receptor shedding, which may explain the differential effects of these isoforms in removing Aβ from the brain. PMID:25015123

  13. Structural and Functional Analysis of the ApolipoproteinA-I A164S Variant

    PubMed Central

    Dalla-Riva, Jonathan; Lagerstedt, Jens O.; Petrlova, Jitka

    2015-01-01

    Apolipoprotein A-I (apoA-I) is the main protein involved in the formation of high-density lipoprotein (HDL), it is the principal mediator of the reverse cholesterol transfer (RCT) pathway and provides cardio-protection. In addition to functional wild-type apoA-I, several variants have been shown to associate with hereditary amyloidosis. In this study we have performed biophysical and biochemical analyses of the structure and functional properties of the A164S variant of apoA-I (1:500 in the Danish general population), which is the first known mutation of apoA-I that leads to an increased risk of ischaemic heart disease (IHD), myocardial infarction and mortality without associated low HDL cholesterol levels. Despite the fact that epidemiologically IHD is associated with low plasma levels of HDL, the A164S mutation is linked to normal plasma levels of lipids, HDL and apoA-I, suggesting impaired functionality of this variant. Using biophysical techniques (e.g., circular dichroism spectroscopy and electron microscopy) to determine secondary structure, stability and pro-amyloidogenic property of the lipid free A164S apoA-I variant, our observations suggest similarity in structural properties between apoA-I WT and apoA-I A164S. However, the A164S apoA-I variant exhibits lower binding affinity to lipids but forms similar sized HDL particles to those produced by WT. PMID:26605794

  14. Kinetics of lipids, apolipoproteins, and cholesteryl ester transfer protein in plasma after a bicycle marathon.

    PubMed

    Föger, B; Wohlfarter, T; Ritsch, A; Lechleitner, M; Miller, C H; Dienstl, A; Patsch, J R

    1994-05-01

    The short-term effects of prolonged intense exercise on plasma lipid transport parameters including cholesterol, triglycerides (TGs), low-density lipoprotein (LD) cholesterol, high-density lipoprotein (HDL) cholesterol, and its subfractions HDL2 cholesterol and HDL3 cholesterol, on apolipoproteins (apos) A-I, A-II, and B, and on mass and activity of cholesteryl ester transfer protein (CETP) were studied in eight male endurance-trained athletes over the first week after a bicycle marathon. CETP mass concentration in plasma was quantified by a newly developed immunoradiometric assay (IRMA). Plasma concentrations of cholesterol, TGs, LDL cholesterol, apo B, CETP, and cholesteryl ester transfer activity (CETA) were significantly reduced in the recovery period compared with pre-exercise values (cholesterol by 20%, P < .05; TGs by 63%, P < .05; LDL cholesterol by 32%, P < .05; apo B by 18%, P < .05; CETP mass by 29%, P < .05; and CETA by 14%, P < .05). HDL cholesterol and HDL2 cholesterol, in contrast, were significantly increased in the post-exercise period (HDL cholesterol by 12%, P < .05, and HDL2 cholesterol by 96%, P < .05), whereas HDL3 cholesterol showed a tendency to decrease in the late recovery period (by 8%, NS). Although changes in cholesterol, triglycerides, HDL cholesterol, LDL cholesterol, apo B, and CETP mass and activity were already evident in the early recovery period, HDL2 cholesterol showed a delayed response, reaching its maximum 72 hours after initiation of exercise.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8177053

  15. Haptoglobin binds apolipoprotein E and influences cholesterol esterification in the cerebrospinal fluid.

    PubMed

    Salvatore, Alfonso; Cigliano, Luisa; Carlucci, Alessandro; Bucci, Enrico M; Abrescia, Paolo

    2009-07-01

    Haptoglobin (Hpt) binds the apolipoprotein (Apo) A-I domain, which is involved in stimulating the enzyme lecithin-cholesterol acyltransferase (LCAT) for cholesterol esterification. This binding was shown to protect ApoA-I against hydroxyl radicals, thus preventing loss of ApoA-I function in enzyme stimulation. In this study, we report that Hpt is also able to bind ApoE. The Hpt binding site on the ApoE structure was mapped by using synthetic peptides, and found homologous to the Hpt binding site of ApoA-I. Hydroxyl radicals promoted in vitro the formation of ApoE-containing adducts which were detected by immunoblotting. Hpt impaired this oxidative modification whereas albumin did not. CSF from patients with multiple sclerosis or subjects without neurodegeneration contains oxidized forms of ApoE and ApoA-I similar to those observed in vitro. CSF was analyzed for its level of ApoA-I, ApoE, Hpt, cholesteryl esters, and unesterified cholesterol. The ratio of esterified with unesterified cholesterol, assumed to reflect the LCAT activity ex vivo, did not correlate with either analyzed protein, but conversely correlated with the ratio [Hpt]/([ApoE]+[ApoA-I]). The results suggest that Hpt might save the function of ApoA-I and ApoE for cholesterol esterification, a process contributing to cholesterol elimination from the brain. PMID:19457062

  16. Apolipoprotein A5, a crucial determinant of plasma triglyceridelevels, is highlyresponsive to PPARalpha activators

    SciTech Connect

    Vu-Dac, Ngoc; Gervois, Philippe; Jakel, Heidi; Nowak, Maxine; Bauge, Eric; Dehondt, Helene; Staels, Bart; Pennacchio, Len A.; Fruchart-Najib, Jamila; Fruchart, Jean-Charles

    2003-03-30

    The recently discovered APOA5 gene has been shown in humans and mice to be important in determining plasma triglycerides (TG) levels, a major cardiovascular disease risk factor. APOAV represents the first described apolipoprotein where over-expression lowers triglyceride levels. Since fibrates represent a commonly used therapy for lowering plasma triglycerides in humans, we investigated their ability to modulate APOA5 gene expression and consequently influence plasma TG levels. Human primary hepatocytes treated with Wy 14,643 or fenofibrate displayed a strong induction of APOA5 mRNA. Deletion and mutagenesis analyses of the proximal APOA5 promoter firmly demonstrate the presence of a functional PPAR response element. These findings demonstrate that APOA5 is a highly responsive PPARa target gene and support its role as a major mediator for how fibrates reduce plasma triglycerides in humans.

  17. Beef in an Optimal Lean Diet study: effects on lipids, lipoproteins, and apolipoproteins123

    PubMed Central

    Roussell, Michael A; Hill, Alison M; Gaugler, Trent L; West, Sheila G; Vanden Heuvel, John P; Alaupovic, Petar; Gillies, Peter J

    2012-01-01

    Background: A Step I diet with lean beef compared with lean white meat both decrease LDL cholesterol. To our knowledge, no studies have evaluated a low–saturated fatty acid (SFA) (<7% calories) diet that contains lean beef. Objective: We studied the effect on LDL cholesterol of cholesterol-lowering diets with varying amounts of lean beef [ie, Dietary Approaches to Stop Hypertension (DASH): 28 g beef/d; Beef in an Optimal Lean Diet (BOLD): 113 g beef/d; and Beef in an Optimal Lean Diet plus additional protein (BOLD+): 153 g beef/d] compared with that of a healthy American diet (HAD). Design: Thirty-six hypercholesterolemic participants (with LDL-cholesterol concentrations >2.8 mmol/L) were randomly assigned to consume each of the 4 diets (HAD: 33% total fat, 12% SFA, 17% protein, and 20 g beef/d), DASH (27% total fat, 6% SFA, 18% protein, and 28 g beef/d), BOLD (28% total fat, 6% SFA, 19% protein, and 113 g beef/d), and BOLD+ (28% total fat, 6% SFA, 27% protein, and 153 g beef/d) for 5 wk. Results: There was a decrease in total cholesterol (TC) and LDL-cholesterol concentrations (P < 0.05) after consumption of the DASH (−0.49 ± 0.11 and −0.37 ± 0.09 mmol/L, respectively), BOLD (−0.48 ± 0.10 and −0.35 ± 0.9 mmol/L, respectively), and BOLD+ (−0.50 ± 0.10 and −0.345 ± 0.09 mmol/L, respectively) diets compared with after consumption of the HAD (−0.22 ± 0.10 and −0.14 ± 0.10 mmol/L, respectively). Apolipoprotein A-I, C-III, and C-III bound to apolipoprotein A1 particles decreased after BOLD and BOLD+ diets compared with after the HAD, and there was a greater decrease in apolipoprotein B after consumption of the BOLD+ diet than after consumption of the HAD (P < 0.05 for both). LDL cholesterol and TC decreased after consumption of the DASH, BOLD, and BOLD+ diets when the baseline C-reactive protein (CRP) concentration was <1 mg/L; LDL cholesterol and TC decreased when baseline CRP concentration was >1 mg/L with the BOLD and BOLD+ diets

  18. Characterization and functional properties of the alpha-amylase inhibitor (alpha-AI) from kidney bean (Phaseolus vulgaris) seeds.

    PubMed

    Le Berre-Anton, V; Bompard-Gilles, C; Payan, F; Rougé, P

    1997-11-14

    Alpha-amylase inhibitor (alpha-AI) from kidney bean (Phaseolus vulgaris L. cv Tendergreen) seeds has been purified to homogeneity by heat treatment in acidic medium, ammonium sulphate fractionation, chromatofocusing and gel filtration. Two isoforms, alpha-AI1 and alpha-AI1', of 43 kDa have been isolated which differ from each other by their isoelectric points and neutral sugar contents. The major isoform alpha-AI1 inhibited human and porcine pancreatic alpha-amylases (PPA) but was devoid of activity on alpha-amylases of bacterial or fungal origins. As shown on the Lineweaver-Burk plots, the nature of the inhibition is explained by a mixed non-competitive inhibition mechanism. Alpha-AI1 formed a 1:2 stoichiometric complex with PPA which showed an optimum pH of 4.5 at 30 degrees C. Owing to the low optimum pH found for alpha-AI activity, inhibitor-containing diets such as beans or transgenic plants expressing alpha-AI should be devoid of any harmful effect on human health. PMID:9428656

  19. AI gamma-ray burst classification: Methodology/preliminary results

    NASA Astrophysics Data System (ADS)

    Hakkila, Jon; Haglin, David J.; Roiger, Richard J.; Mallozzi, Robert S.; Pendleton, Geoffrey N.; Meegan, Charles A.

    1998-05-01

    Artificial intelligence (AI) classifiers can be used to classify unknowns, refine existing classification parameters, and identify/screen-out ineffectual parameters. We present an AI methodology for classifying gamma-ray bursts, along with some preliminary results.

  20. Apolipoprotein E: Risk factor for Alzheimer disease

    SciTech Connect

    Tsai, M.S.; Thibodeau, S.N.; Tangalos, E.G.; Petersen, R.C.; Kokmen, E.; Smith, G.E.; Schaid, D.J.; Ivnik, R.J. )

    1994-04-01

    The apolipoprotein E gene (APOE) has three common alleles (E2, E3, and E4) that determine six genotypes in the general population. In this study, the authors examined 77 patients with late-onset Alzheimer disease (AD), along with an equal number of age- and sex-matched controls, for an association with the APOE-E4 allele. They show that the frequency of this allele among AD patients was significantly higher than that among the control population (.351 vs. .130, P = .000006). The genotype frequencies also differed between the two groups (P = .0002), with the APOE-E4/E3 genotype being the most common in the AD group and the APOE-E3/E3 being the most common in the control group. In the AD group, homozygosity for E4 was found in nine individuals, whereas none was found in the control group. The odds ratio for AD, when associated with one or two E4 alleles, was 4.6 (95% confidence interval [CI] 1.9-12.3), while the odds ratio for AD, when associated with heterozygosity for APOE-E4, was 3.6 (05% CI 1.5-9.8). Finally, the median age at onset among the AD patients decreased from 83 to 78 to 74 years as the number of APOE-E4 alleles increased from 0 to 1 to 2, respectively (test for trend, P = .001). The data, which are in agreement with recent reports, suggest that the APOE-E4 allele is associated with AD and that this allelic variant may be an important risk factor for susceptibility to AD in the general population. 30 refs., 5 tabs.

  1. Fertility of holstein dairy heifers after synchronization of ovulation and timed AI or AI after removed tail chalk.

    PubMed

    Rivera, H; Lopez, H; Fricke, P M

    2004-07-01

    Nonlactating Holstein dairy heifers (n=352) 13 mo of age were managed using a 42-d artificial insemination (AI) breeding period in which they received AI after removed tail chalk evaluated once daily. At AI breeding period onset (d 0), heifers were randomly assigned to receive synchronization of ovulation (100 microg of GnRH, d 0; 25 mg of PGF2alpha, d 6; 100 microg of GnRH, d 8) and timed AI (TAI; d 8) and AI after removed tail chalk for the entire AI breeding period (GPG; n=175), or AI after removed tail chalk for the entire AI breeding period (TC; n=177). As expected, 17.7% (31/175) of GPG heifers received AI after removed tail chalk before scheduled TAI. Pregnancy rate per artificial insemination (PR/AI) at approximately 30 d after first AI tended to be greater for TC (46.5%) than for GPG (38.3%) heifers. No treatment x inseminator interaction was detected; however, overall PR/AI was low for heifers in both treatments due to variation among the 3 inseminators (24.8, 30.0, and 58.0%). Pregnancy loss from approximately 30 to approximately 75 d after first AI was 10% and did not differ between treatments. Based on survival analysis, days to first AI was greater for TC than for GPG heifers, whereas days to pregnancy across the 42-d AI breeding period did not differ between treatments. Overall, 81.2% of GPG heifers receiving TAI synchronized luteal regression and ovulated within 48 h after the second GnRH injection. We conclude that this synchronization protocol can yield acceptable fertility in dairy heifers if AI to estrus is conducted between treatment with GnRH and PGF2alpha and AI efficiency is optimized. PMID:15328217

  2. The Fat-Fed Apolipoprotein E Knockout Mouse Brachiocephalic Artery in the Study of Atherosclerotic Plaque Rupture

    PubMed Central

    Bond, Andrew R.; Jackson, Christopher L.

    2011-01-01

    Atherosclerosis has been studied in animals for almost a century, yet the events leading up to the rupture of an atherosclerotic plaque (the underlying cause of the majority of fatal thrombosis formation) have only been studied in the past decade, due in part to the development of a mouse model of spontaneous plaque rupture. Apolipoprotein E knockout mice, when fed a high-fat diet, consistently develop lesions in the brachiocephalic artery that rupture at a known time point. It is therefore now possible to observe the development of lesions to elucidate the mechanisms behind the rupture of plaques. Critics argue that the model does not replicate the appearance of human atherosclerotic plaque ruptures. The purpose of this review is to highlight the reasons why we should be looking to the apolipoprotein E knockout mouse to further our understanding of plaque rupture. PMID:21076539

  3. AI in space: Past, present, and possible futures

    NASA Technical Reports Server (NTRS)

    Rose, Donald D.; Post, Jonathan V.

    1992-01-01

    While artificial intelligence (AI) has become increasingly present in recent space applications, new missions being planned will require even more incorporation of AI techniques. In this paper, we survey some of the progress made to date in implementing such programs, some current directions and issues, and speculate about the future of AI in space scenarios. We also provide examples of how thinkers from the realm of science fiction have envisioned AI's role in various aspects of space exploration.

  4. Tel Aviv-Heidelberg three-generation offspring study: Genetic determinants of apolipoprotein A1 and apolipoprotein B

    SciTech Connect

    Livshits, G.; Graff, E.; Brunner, D.

    1995-07-03

    The contribution of major gene and multifactorial effects on variation of plasma apolipoproteins A1 and B has been tested in a large sample of population-based Israeli pedigrees. Our most parsimonious and best fitting model for both apolipoproteins is consistent with Mendelian transmissibility, with significant contribution of major genes (with 2 alleles recessive and dominant within each locus) and polygenes, but neglects effects of common sib environment as well as related intergeneration differences in polygenic effects. Total genetic effects explain 71 and 58% of phenotypic variance of APO-A1 and APO-B levels. The major genes account for about 44 and 32% of the variance in APO-A1 and APO-B, respectively, and the frequency of the recessive alleles determining the high level of apolipoproteins under the study in the Israeli population is in the vicinity of 40% at each locus. 27 refs, 1 fig., 4 tabs.

  5. Why Don't Accounting Students like AIS?

    ERIC Educational Resources Information Center

    Vatanasakdakul, Savanid; Aoun, Chadi

    2011-01-01

    Purpose: The demand for Accounting Information Systems (AIS) knowledge has increased exponentially over the past two decades, but studying AIS has not proved easy for many accounting students. The aim of the study is to understand the challenges accounting students face in studying AIS through investigation of the factors which may be contributing…

  6. 47 CFR 80.393 - Frequencies for AIS stations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... requirements for non-Federal Government ships. These requirements are codified at 33 CFR 164.46, 401.20. ... 47 Telecommunication 5 2012-10-01 2012-10-01 false Frequencies for AIS stations. 80.393 Section 80... STATIONS IN THE MARITIME SERVICES Frequencies Ais Stations § 80.393 Frequencies for AIS stations....

  7. The AI Interdisciplinary Context: Single or Multiple Research Bases?

    ERIC Educational Resources Information Center

    Khawam, Yves J.

    1992-01-01

    This study used citation analysis to determine whether the disciplines contributing to the journal literature of artificial intelligence (AI)--philosophy, psychology, linguistics, computer science, and engineering--share a common AI research base. The idea that AI consists of a completely interdisciplinary endeavor was refuted. (MES)

  8. Solid lipid nanoparticles as a vehicle for brain-targeted drug delivery: two new strategies of functionalization with apolipoprotein E

    NASA Astrophysics Data System (ADS)

    Rute Neves, Ana; Fontes Queiroz, Joana; Weksler, Babette; Romero, Ignacio A.; Couraud, Pierre-Olivier; Reis, Salette

    2015-12-01

    Nanotechnology can be an important tool to improve the permeability of some drugs for the blood-brain barrier. In this work we created a new system to enter the brain by functionalizing solid lipid nanoparticles with apolipoprotein E, aiming to enhance their binding to low-density lipoprotein receptors on the blood-brain barrier endothelial cells. Solid lipid nanoparticles were successfully functionalized with apolipoprotein E using two distinct strategies that took advantage of the strong interaction between biotin and avidin. Transmission electron microscopy images revealed spherical nanoparticles, and dynamic light scattering gave a Z-average under 200 nm, a polydispersity index below 0.2, and a zeta potential between -10 mV and -15 mV. The functionalization of solid lipid nanoparticles with apolipoprotein E was demonstrated by infrared spectroscopy and fluorimetric assays. In vitro cytotoxic effects were evaluated by MTT and LDH assays in the human cerebral microvascular endothelial cells (hCMEC/D3) cell line, a human blood-brain barrier model, and revealed no toxicity up to 1.5 mg ml-1 over 4 h of incubation. The brain permeability was evaluated in transwell devices with hCMEC/D3 monolayers, and a 1.5-fold increment in barrier transit was verified for functionalized nanoparticles when compared with non-functionalized ones. The results suggested that these novel apolipoprotein E-functionalized nanoparticles resulted in dynamic stable systems capable of being used for an improved and specialized brain delivery of drugs through the blood-brain barrier.

  9. Solid lipid nanoparticles as a vehicle for brain-targeted drug delivery: two new strategies of functionalization with apolipoprotein E.

    PubMed

    Neves, Ana Rute; Queiroz, Joana Fontes; Weksler, Babette; Romero, Ignacio A; Couraud, Pierre-Olivier; Reis, Salette

    2015-12-11

    Nanotechnology can be an important tool to improve the permeability of some drugs for the blood-brain barrier. In this work we created a new system to enter the brain by functionalizing solid lipid nanoparticles with apolipoprotein E, aiming to enhance their binding to low-density lipoprotein receptors on the blood-brain barrier endothelial cells. Solid lipid nanoparticles were successfully functionalized with apolipoprotein E using two distinct strategies that took advantage of the strong interaction between biotin and avidin. Transmission electron microscopy images revealed spherical nanoparticles, and dynamic light scattering gave a Z-average under 200 nm, a polydispersity index below 0.2, and a zeta potential between -10 mV and -15 mV. The functionalization of solid lipid nanoparticles with apolipoprotein E was demonstrated by infrared spectroscopy and fluorimetric assays. In vitro cytotoxic effects were evaluated by MTT and LDH assays in the human cerebral microvascular endothelial cells (hCMEC/D3) cell line, a human blood-brain barrier model, and revealed no toxicity up to 1.5 mg ml(-1) over 4 h of incubation. The brain permeability was evaluated in transwell devices with hCMEC/D3 monolayers, and a 1.5-fold increment in barrier transit was verified for functionalized nanoparticles when compared with non-functionalized ones. The results suggested that these novel apolipoprotein E-functionalized nanoparticles resulted in dynamic stable systems capable of being used for an improved and specialized brain delivery of drugs through the blood-brain barrier. PMID:26574295

  10. Non-apolipoprotein E and apolipoprotein E genetics of sporadic Alzheimer's disease.

    PubMed

    Seripa, Davide; Panza, Francesco; Franceschi, Marilisa; D'Onofrio, Grazia; Solfrizzi, Vincenzo; Dallapiccola, Bruno; Pilotto, Alberto

    2009-07-01

    The genetic epidemiology of sporadic Alzheimer's disease (SAD) remains a very active area of research,making it one of the most prolifically published areas in medicine and biology. Numerous putative candidate genes have been proposed. However, with the exception of apolipoprotein E (APOE), the only confirmed genetic risk factor for SAD, all the other data appear to be not consistent. Nevertheless, the genetic risk for SAD attributable to the APOE gene in the general population is 20-0%, providing a strong evidence for the existence of additional genetic risk factors. The first part of the present article was dedicated to non-APOE genetics of SAD, reviewing chromosomes-by-chromosomes the available data concerning the major candidate genes. The second part of this article focused on some recently discovered aspects of the APOE polymorphism and their implications for SAD. An attempt to identify the future directions for non-APOE genetic research in SAD was also discussed. PMID:19496238

  11. Expression and prognostic significance of apolipoprotein D in breast cancer.

    PubMed Central

    Díez-Itza, I.; Vizoso, F.; Merino, A. M.; Sánchez, L. M.; Tolivia, J.; Fernández, J.; Ruibal, A.; López-Otín, C.

    1994-01-01

    Apolipoprotein D (apo D) is a glycoprotein involved in the human plasma lipid transport system and present at large amounts in cyst fluid from women with gross cystic disease of the breast. Apo D expression in breast carcinomas was examined by immunoperoxidase staining of a series of 163 tumors. A total of 60 (36.8%) tumors were negative for apo D immunostaining, 28 (17.2%) carcinomas were weakly positive, 33 (20.2%) were moderately stained, whereas the remaining 42 (25.8%) tumors were strongly stained with the specific antibodies. No significant correlation was found between apo D content and tumor size, lymph node involvement, or biochemical parameters such as estrogen receptors, cathepsin D, or pS2 protein. However, the finding of a significant association between apo D and menopausal status of patients or differentiation grade of tumors, with apo D values being lower in tumors from premenopausal women or in poorly differentiated carcinomas, suggested a potential value of this glycoprotein as a prognostic factor in breast cancer. Preliminary analysis of relapse-free survival and overall survival in a subgroup of 152 women with a mean follow-up of 42 months confirmed that low apo D values were significantly associated to a shorter relapse-free survival and poorer survival. According to these data, we propose that apo D in combination with other well-established prognostic factors may contribute to more accurately identify subgroups of breast cancer patients with low or high risk for relapse and death. Images Figure 1 Figure 2 Figure 3 PMID:8311115

  12. Apolipoproteins and lipoproteins in children with type I diabetes: relation to glycosylated serum protein and HbA1.

    PubMed

    Strobl, W; Widhalm, K; Schober, E; Frisch, H; Pollak, A; Westphal, G

    1985-11-01

    Serum levels of cholesterol (C), triglycerides (TG), lipoprotein-C and apolipoproteins (apo) A-I, A-II and B were measured in 30 children with type I diabetes mellitus (16 boys, 14 girls, aged 11-14 years) and in 26 healthy controls (15 boys, 11 girls, aged 10-13 years). For 19 diabetics controls matched for age, sex and relative body weight were selected. The diabetic patients were considered to be in fair metabolic control according to HbA1 levels and glycosylated serum protein concentrations. Mean serum apo A-I, A-II and B, C, TG, low density lipoprotein cholesterol (LDL-C) and high density lipoprotein cholesterol (HDL-C) did not differ significantly between diabetic nondiabetic children. Very low density lipoprotein cholesterol (VLDL-C) was significantly higher in diabetic children than in controls. Serum C and LDL-C levels showed close univariate linear correlations with glycosylated serum protein (LDL-C: r = 0.53, p less than 0.01, C: r = 0.58, p less than 0.01) in diabetics. The ratio LDL/HDL-C was significantly correlated to HbA1 levels (r = 0.47, p less than 0.01). By canonical and multiple linear correlation analysis significant relations of a selected set of variables concerning the control and therapy of diabetes (serum glucose, HbA1, glycosylated serum protein, insulin dose) with a set of lipoprotein variables (C, TG, VLDL-C, HDL-C, LDL-C, apo A-I, A-II, B) could be demonstrated. From these data we conclude that significant relations between atherogenic serum lipids and lipoproteins (C, LDL-C) and the degree of metabolic control exist in diabetic children, even in the absence of marked dyslipoproteinemia.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:4090971

  13. SDI satellite autonomy using AI and Ada

    NASA Technical Reports Server (NTRS)

    Fiala, Harvey E.

    1990-01-01

    The use of Artificial Intelligence (AI) and the programming language Ada to help a satellite recover from selected failures that could lead to mission failure are described. An unmanned satellite will have a separate AI subsystem running in parallel with the normal satellite subsystems. A satellite monitoring subsystem (SMS), under the control of a blackboard system, will continuously monitor selected satellite subsystems to become alert to any actual or potential problems. In the case of loss of communications with the earth or the home base, the satellite will go into a survival mode to reestablish communications with the earth. The use of an AI subsystem in this manner would have avoided the tragic loss of the two recent Soviet probes that were sent to investigate the planet Mars and its moons. The blackboard system works in conjunction with an SMS and a reconfiguration control subsystem (RCS). It can be shown to be an effective way for one central control subsystem to monitor and coordinate the activities and loads of many interacting subsystems that may or may not contain redundant and/or fault-tolerant elements. The blackboard system will be coded in Ada using tools such as the ABLE development system and the Ada Production system.

  14. Optimization of apolipoprotein-B-100 sequence coverage by liquid chromatography-tandem mass spectrometry for the future study of its posttranslational modifications.

    PubMed

    Delporte, Cédric; Van Antwerpen, Pierre; Zouaoui Boudjeltia, Karim; Noyon, Caroline; Abts, Frédéric; Métral, Frédéric; Vanhamme, Luc; Reyé, Florence; Rousseau, Alexandre; Vanhaeverbeek, Michel; Ducobu, Jean; Nève, Jean

    2011-04-01

    Proteomic applications have been increasingly used to study posttranslational modifications of proteins (PTMs). For the purpose of identifying and localizing specific but unknown PTMs on huge proteins, improving their sequence coverage is fundamental. Using liquid chromatography coupled to mass spectrometry (LC-MS/MS), peptide mapping of the native apolipoprotein-B-100 was performed to further document the effects of oxidation. Apolipoprotein-B-100 is the main protein of low-density lipoprotein particles and its oxidation could play a role in atherogenesis. Because it is one of the largest human proteins, the sequence recovery rate of apolipoprotein-B-100 only reached 1% when conventional analysis parameters were used. The different steps of the peptide mapping process-from protein treatment to data analysis-were therefore reappraised and optimized. These optimizations allowed a protein sequence recovery rate of 79%, a rate which has never been achieved previously for such a large human protein. The key points for improving peptide mapping were optimization of the data analysis software; peptide separation by LC; sample preparation; and MS acquisition. The new protocol has allowed us to increase by a factor of 4 the detection of modified peptides in apolipoprotein-B-100. This approach could easily be transferred to any study of PTMs using LC-MS/MS. PMID:21129357

  15. APOLIPOPROTEIN E GENE AND EARLY AGE-RELATED MACULOPATHY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    OBJECTIVE: To examine the association between the apolipoprotein E (APOE) gene and early age-related maculopathy (ARM) in middle-aged persons. DESIGN: Population-based cross-sectional study. PARTICIPANTS: Participants from the Atherosclerosis Risk in Communities Study (n = 10139; age range, 49-73 ye...

  16. Manipulation of the quorum sensing signal AI-2 affects the antibiotic-treated gut microbiota.

    PubMed

    Thompson, Jessica Ann; Oliveira, Rita Almeida; Djukovic, Ana; Ubeda, Carles; Xavier, Karina Bivar

    2015-03-24

    The mammalian gut microbiota harbors a diverse ecosystem where hundreds of bacterial species interact with each other and their host. Given that bacteria use signals to communicate and regulate group behaviors (quorum sensing), we asked whether such communication between different commensal species can influence the interactions occurring in this environment. We engineered the enteric bacterium, Escherichia coli, to manipulate the levels of the interspecies quorum sensing signal, autoinducer-2 (AI-2), in the mouse intestine and investigated the effect upon antibiotic-induced gut microbiota dysbiosis. E. coli that increased intestinal AI-2 levels altered the composition of the antibiotic-treated gut microbiota, favoring the expansion of the Firmicutes phylum. This significantly increased the Firmicutes/Bacteroidetes ratio, to oppose the strong effect of the antibiotic, which had almost cleared the Firmicutes. This demonstrates that AI-2 levels influence the abundance of the major phyla of the gut microbiota, the balance of which is known to influence human health. PMID:25801025

  17. Mechanism and Physiologic Significance of the Suppression of Cholesterol Esterification in Human Interstitial Fluid.

    PubMed

    Miller, Norman E; Olszewski, Waldemar L; Miller, Irina P; Nanjee, Mahmud N

    2016-01-01

    Cholesterol esterification in high density lipoproteins (HDLs) by lecithin:cholesterol acyltransferase (LCAT) promotes unesterified cholesterol (UC) transfer from red cell membranes to plasma in vitro. However, it does not explain the transfer of UC from most peripheral cells to interstitial fluid in vivo, as HDLs in afferent peripheral lymph are enriched in UC. Having already reported that the endogenous cholesterol esterification rate (ECER) in lymph is only 5% of that in plasma, we have now explored the underlying mechanism. In peripheral lymph from 20 healthy men, LCAT concentration, LCAT activity (assayed using an optimized substrate), and LCAT specific activity averaged, respectively, 11.8, 10.3, and 84.9% of plasma values. When recombinant human LCAT was added to lymph, the increments in enzyme activity were similar to those when LCAT was added to plasma. Addition of apolipoprotein AI (apo AI), fatty acid-free albumin, Intralipid, or the d < 1.006 g/ml plasma fraction had no effect on ECER. During incubation of lymph plus plasma, the ECER was similar to that observed with buffer plus plasma. When lymph was added to heat-inactivated plasma, the ECER was 11-fold greater than with lymph plus buffer. Addition of discoidal proteoliposomes of apo AI and phosphatidycholine (PC) to lymph increased ECER 10-fold, while addition of apo AI/PC/UC disks did so by only six-fold. We conclude that the low ECER in lymph is due to a property of the HDLs, seemingly substrate inhibition of LCAT by excess cell-derived UC. This is reversed when lymph enters plasma, consequent upon redistribution of UC from lymph HDLs to plasma lipoproteins. PMID:27471469

  18. Mechanism and Physiologic Significance of the Suppression of Cholesterol Esterification in Human Interstitial Fluid

    PubMed Central

    Miller, Norman E.; Olszewski, Waldemar L.; Miller, Irina P.; Nanjee, Mahmud N.

    2016-01-01

    Cholesterol esterification in high density lipoproteins (HDLs) by lecithin:cholesterol acyltransferase (LCAT) promotes unesterified cholesterol (UC) transfer from red cell membranes to plasma in vitro. However, it does not explain the transfer of UC from most peripheral cells to interstitial fluid in vivo, as HDLs in afferent peripheral lymph are enriched in UC. Having already reported that the endogenous cholesterol esterification rate (ECER) in lymph is only 5% of that in plasma, we have now explored the underlying mechanism. In peripheral lymph from 20 healthy men, LCAT concentration, LCAT activity (assayed using an optimized substrate), and LCAT specific activity averaged, respectively, 11.8, 10.3, and 84.9% of plasma values. When recombinant human LCAT was added to lymph, the increments in enzyme activity were similar to those when LCAT was added to plasma. Addition of apolipoprotein AI (apo AI), fatty acid-free albumin, Intralipid, or the d < 1.006 g/ml plasma fraction had no effect on ECER. During incubation of lymph plus plasma, the ECER was similar to that observed with buffer plus plasma. When lymph was added to heat-inactivated plasma, the ECER was 11-fold greater than with lymph plus buffer. Addition of discoidal proteoliposomes of apo AI and phosphatidycholine (PC) to lymph increased ECER 10-fold, while addition of apo AI/PC/UC disks did so by only six-fold. We conclude that the low ECER in lymph is due to a property of the HDLs, seemingly substrate inhibition of LCAT by excess cell-derived UC. This is reversed when lymph enters plasma, consequent upon redistribution of UC from lymph HDLs to plasma lipoproteins. PMID:27471469

  19. Suppressive effects of cacao polyphenols on the development of atherosclerosis in apolipoprotein E-deficient mice.

    PubMed

    Natsume, Midori; Baba, Seigo

    2014-01-01

    Previous studies in humans have shown that the cacao polyphenols, (-)-epicatechin and its oligomers, prevent in vitro and ex vivo low-density lipoprotein oxidation mediated by free radical generators and metal ions and also reduce plasma LDL-cholesterol levels. The aim of this study was to examine the effects of cacao polyphenols on the development of atherosclerosis in apolipoprotein E-deficient (-/-) mice. Mice aged 8 weeks (n = 90) were randomized into three groups, and fed either normal mouse chow (controls) or chow supplemented with 0.25 or 0.40 % cacao polyphenols for 16 weeks. The mean plaque area in cross-sections of the brachiocephalic trunk was measured and found to be lower in the 0.25 % cacao polyphenol group than in the control group (p < 0.05). Pathological observations showed that accumulation of cholesterol crystals in the plaque area was greater in the control group compared with the 0.40 % cacao polyphenol group (p < 0.05). Immunochemical staining in the 0.25 and 0.40 % groups showed that expression of the cell adhesion molecules (VCAM-1 and ICAM-1) and production of oxidative stress markers (4-hydroxynonenal, hexanoyl-lysine, and dityrosine) were reduced in cross-sections of the brachiocephalic trunk. These results suggest that cacao polyphenols inhibit the development of atherosclerosis in apolipoprotein E-deficient (-/-) mice by reducing oxidative stress and inflammatory responses. PMID:24374929

  20. The structure of dimeric apolipoprotein A-IV and its mechanism of self-association

    PubMed Central

    Deng, Xiaodi; Morris, Jamie; Dressmen, James; Tubb, Matthew R; Tso, Patrick; Jerome, W Gray; Davidson, W Sean; Thompson, Thomas B

    2012-01-01

    Summary Apolipoproteins are key structural elements of lipoproteins and critical mediators of lipid metabolism. Their detergent-like properties allow them to emulsify lipid or exist in a soluble lipid-free form in various states of self-association. Unfortunately, these traits have hampered high-resolution structural studies needed to understand the biogenesis of cardioprotective high-density lipoproteins (HDL). We derived a crystal structure of the core domain of human apolipoprotein (apo)A-IV, an HDL component and important mediator of lipid absorption. The structure at 2.4 Å depicts two linearly connected 4-helix bundles participating in a helix swapping arrangement that offers a clear explanation for how the protein self-associates as well as clues to the structure of its monomeric form. This also provides a logical basis for antiparallel arrangements recently described for lipid-containing particles. Furthermore, we propose a “swinging door” model for apoA-IV lipid association. PMID:22579246

  1. Apolipoprotein C-I is an APOE genotype-dependent suppressor of glial activation

    PubMed Central

    2012-01-01

    Background Inheritance of the human ϵ4 allele of the apolipoprotein (apo) E gene (APOE) significantly increases the risk of developing Alzheimer’s disease (AD), in addition to adversely influencing clinical outcomes of other neurologic diseases. While apoE isoforms differentially interact with amyloid β (Aβ), a pleiotropic neurotoxin key to AD etiology, more recent work has focused on immune regulation in AD pathogenesis and on the mechanisms of innate immunomodulatory effects associated with inheritance of different APOE alleles. APOE genotype modulates expression of proximal genes including APOC1, which encodes a small apolipoprotein that is associated with Aβ plaques. Here we tested the hypothesis that APOE-genotype dependent innate immunomodulation may be mediated in part by apoC-I. Methods ApoC-I concentration in cerebrospinal fluid from control subjects of differing APOE genotypes was quantified by ELISA. Real-time PCR and ELISA were used to analyze apoC-I mRNA and protein expression, respectively, in liver, serum, cerebral cortex, and cultured primary astrocytes derived from mice with targeted replacement of murine APOE for human APOE ϵ3 or ϵ4. ApoC-I direct modulation of innate immune activity was investigated in cultured murine primary microglia and astrocytes, as well as human differentiated macrophages, using specific toll-like receptor agonists LPS and PIC as well as Aβ. Results ApoC-I levels varied with APOE genotype in humans and in APOE targeted replacement mice, with ϵ4 carriers showing significantly less apoC-I in both species. ApoC-I potently reduced pro-inflammatory cytokine secretion from primary murine microglia and astrocytes, and human macrophages, stimulated with LPS, PIC, or Aβ. Conclusions ApoC-I is immunosuppressive. Our results illuminate a novel potential mechanism for APOE genotype risk for AD; one in which patients with an ϵ4 allele have decreased expression of apoC-I resulting in increased innate immune activity. PMID

  2. Neuropathology and apolipoprotein E profile of aged chimpanzees: implications for Alzheimer disease.

    PubMed Central

    Gearing, M; Rebeck, G W; Hyman, B T; Tigges, J; Mirra, S S

    1994-01-01

    Neuropathological findings in three aged chimpanzees were compared with those in rhesus monkeys and individuals with Alzheimer disease. Senile plaques and blood vessels were immunoreactive for amyloid beta-protein and apolipoprotein E (apoE) in the nonhuman primates, recapitulating findings in human aging and Alzheimer disease. Neurofibrillary tangles, another hallmark of Alzheimer disease, were absent. PCR/restriction-enzyme analysis in chimpanzees revealed an APOE profile similar to the human APOE type 4 allele associated with an increased risk of Alzheimer disease. These findings militate against the hypothesis that the absence of APOE type 3 allele predisposes to neurofibrillary tangle formation and support the value of aged primates for exploring mechanisms of amyloid processing and the role of apoE. Images PMID:7937774

  3. Melissa officinalis essential oil reduces plasma triglycerides in human apolipoprotein E2 transgenic mice by inhibiting sterol regulatory element-binding protein-1c-dependent fatty acid synthesis.

    PubMed

    Jun, Hee-Jin; Lee, Ji Hae; Jia, Yaoyao; Hoang, Minh-Hien; Byun, Hanna; Kim, Kyoung Heon; Lee, Sung-Joon

    2012-03-01

    We investigated the hypolipidemic effects of Melissa officinalis essential oil (MOEO) in human APOE2 transgenic mice and lipid-loaded HepG2 cells. Plasma TG concentrations were significantly less in APOE2 mice orally administered MOEO (12.5 μg/d) for 2 wk than in the vehicle-treated group. Cellular TG and cholesterol concentrations were also significantly decreased in a dose- (400 and 800 mg/L) and time- (12 and 24 h) dependent manner in HepG2 cells stimulated with MOEO compared with controls. Mouse hepatic transcriptome analysis suggested MOEO feeding altered several lipid metabolic pathways, including bile acid and cholesterol synthesis and fatty acid metabolism. In HepG2 cells, the rate of fatty acid oxidation, as assessed using [1-(14)C]palmitate, was unaltered; however, the rate of fatty acid synthesis quantified with [1-(14)C]acetate was significantly reduced by treatment with 400 and 800 mg/L MOEO compared with untreated controls. This reduction was due to the decreased expression of SREBP-1c and its responsive genes in fatty acid synthesis, including FAS, SCD1, and ACC1. Subsequent chromatin immunoprecipitation analysis further demonstrated that the binding of p300/CBP-associated factor, a coactivator of SREBP-1c, and histone H3 lysine 14 acetylation at the FAS, SCD1, and ACC1 promoters were significantly reduced in the livers of APOE2 mice and HepG2 cells treated with MOEO compared with their controls. Additionally, MOEO stimulation in HepG2 cells induced bile acid synthesis and reduced the nuclear form of SREBP-2, a key transcription factor in hepatic cholesterol synthesis. These findings suggest that the intake of phytochemicals with pleasant scent could have beneficial metabolic effects. PMID:22279139

  4. Delivery of hydrophilic drug doxorubicin hydrochloride-targeted liver using apoAI as carrier.

    PubMed

    Yuan, Yuan; Wang, Weina; Wang, Baolong; Zhu, Haiyan; Zhang, Boheng; Feng, Meiqing

    2013-05-01

    High-density lipoprotein (HDL) particles can deliver cholesterol from peripheral tissues to the liver through apolipoprotein A1 (Apo A1), which specifically binds to the scavenger receptor class B type 1 (SR-B1) receptor on the surface of hepatocytes. Therefore, ApoA1 can be potentially used to target drugs to the liver. In this study, we successfully loaded doxorubicin hydrochloride (Dox or Dox-HCl), which is a hydrophilic drug used in a wide variety of clinical applications, into the core of reconstituted HDL (rHDL prepared by apoAI and egg phospholipids) to form a doxorubicin-HDL complex (rHDL-Dox). The MTT assays showed that rHDL-Dox particles also had higher cytotoxicity against several cells lines compared to free drug or Dox encapsulated into liposomes. A cellular uptake assay demonstrated that rHDL-Dox had higher absorption in SR-BI receptor positive liver cells. Importantly, in vivo experiments showed that rHDL-Dox can reduce tumor growth more effectively than liposomes. In addition, an in vitro hemolysis assay showed that rHDL-Dox caused only limited hemolysis in the case of high doses. Taken together, our findings indicate that rHDL is a safe and effective drug delivery system for targeting liver. PMID:23600747

  5. Integrating Vision and AI for Industrial Applications

    NASA Astrophysics Data System (ADS)

    Batchelor, Bruce G.

    1990-03-01

    The article describes an extension to the well-established AI language Prolog. This allows Prolog to operate both an image processing system and a controller for a variety of electro-mechanical devices. The user can define his/her own pull-down menus and provides an interface to a speech synthesis package. The latter enables the user to follow the flow of a program, easily and in a natural way. The application of the software to food inspection is also discussed

  6. Bare PCB test method based on AI

    NASA Astrophysics Data System (ADS)

    Li, Aihua; Zhou, Huiyang; Wan, Nianhong; Qu, Liangsheng

    1995-08-01

    The shortcomings of conventional methods used for developing test sets on current automated printed circuit board (PCB) test machines consist of overlooking the information from CAD, historical test data, and the experts' knowledge. Thus, the generated test sets and proposed test sequence may be sub-optimal and inefficient. This paper presents a weighting bare PCB test method based on analysis and utilization of the CAD information. AI technique is applied for faults statistics and faults identification. Also, the generation of test sets and the planning of test procedure are discussed. A faster and more efficient test system is achieved.

  7. Will AI in pigs become more efficient?

    PubMed

    Roca, J; Parrilla, I; Bolarin, A; Martinez, E A; Rodriguez-Martinez, H

    2016-07-01

    AI is commercially applied worldwide to breed pigs, yielding fertility outcomes similar to those of natural mating. However, it is not fully efficient, as only liquid-stored semen is used, with a single boar inseminating about 2000 sows yearly. The use of liquid semen, moreover, constrains international trade and slows genetic improvement. Research efforts, reviewed hereby, are underway to reverse this inefficient scenario. Special attention is paid to studies intended to decrease the number of sperm used per pregnant sow, facilitating the practical use of sexed frozen-thawed semen in swine commercial insemination programs. PMID:26723133

  8. Research needs for AI in manufacturing

    NASA Astrophysics Data System (ADS)

    Triscari, T., Jr.; Henghold, W. M.

    The Air Force Wright Aeronautical Laboratories' Material Laboratory is charged with developing a research program for applications of artificial intelligence (AI) as it relates to manufacturing. As a part of program development, advisory input was sought from experts from industry, academia, and government. A structured methodology was employed which featured a top-down approach leading from concept level articulation, through application area goals and objectives, to project level detail. This paper documents the effort in terms of providing methodological background, application area goals and objectives, and results obtained from project generation and assessment. Emphasis is on project level results.

  9. AI Based Personal Learning Environments: Directions for Long Term Research. AI Memo 384.

    ERIC Educational Resources Information Center

    Goldstein, Ira P.; Miller, Mark L.

    The application of artificial intelligence (AI) techniques to the design of personal learning environments is an enterprise of both theoretical and practical interest. In the short term, the process of developing and testing intelligent tutoring programs serves as a new experimental vehicle for exploring alternative cognitive and pedagogical…

  10. Increased HDL Size and Enhanced Apo A-I Catabolic Rates Are Associated With Doxorubicin-Induced Proteinuria in New Zealand White Rabbits.

    PubMed

    López-Olmos, Victoria; Carreón-Torres, Elizabeth; Luna-Luna, María; Flores-Castillo, Cristobal; Martínez-Ramírez, Miriam; Bautista-Pérez, Rocío; Franco, Martha; Sandoval-Zárate, Julio; Roldán, Francisco-Javier; Aranda-Fraustro, Alberto; Soria-Castro, Elizabeth; Muñoz-Vega, Mónica; Fragoso, José-Manuel; Vargas-Alarcón, Gilberto; Pérez-Méndez, Oscar

    2016-03-01

    The catabolism and structure of high-density lipoproteins (HDL) may be the determining factor of their atheroprotective properties. To better understand the role of the kidney in HDL catabolism, here we characterized HDL subclasses and the catabolic rates of apo A-I in a rabbit model of proteinuria. Proteinuria was induced by intravenous administration of doxorubicin in New Zealand white rabbits (n = 10). HDL size and HDL subclass lipids were assessed by electrophoresis of the isolated lipoproteins. The catabolic rate of HDL-apo A-I was evaluated by exogenous radiolabelling with iodine-131. Doxorubicin induced significant proteinuria after 4 weeks (4.47 ± 0.55 vs. 0.30 ± 0.02 g/L of protein in urine, P < 0.001) associated with increased uremia, creatininemia, and cardiotoxicity. Large HDL2b augmented significantly during proteinuria, whereas small HDL3b and HDL3c decreased compared to basal conditions. HDL2b, HDL2a, and HDL3a subclasses were enriched with triacylglycerols in proteinuric animals as determined by the triacylglycerol-to-phospholipid ratio; the cholesterol content in HDL subclasses remained unchanged. The fractional catabolic rate (FCR) of [(131)I]-apo A-I in the proteinuric rabbits was faster (FCR = 0.036 h(-1)) compared to control rabbits group (FCR = 0.026 h(-1), P < 0.05). Apo E increased and apo A-I decreased in HDL, whereas PON-1 activity increased in proteinuric rabbits. Proteinuria was associated with an increased number of large HDL2b particles and a decreased number of small HDL3b and 3c. Proteinuria was also connected to an alteration in HDL subclass lipids, apolipoprotein content of HDL, high paraoxonase-1 activity, and a rise in the fractional catabolic rate of the [(131)I]-apo A-I. PMID:26781765

  11. AIS spectra of desert shrub canopies

    NASA Technical Reports Server (NTRS)

    Murray, R.; Isaacson, D. L.; Schrumpf, B. J.; Ripple, W. J.; Lewis, A. J.

    1986-01-01

    Airborne Imaging Spectrometer (AIS) data were collected 30 August 1985 from a desert shrub community in central Oregon. Spectra from artificial targets placed on the test site and from bare soil, big sagebrush (Artemesia tridentata wyomingensis), silver sagebrush (Artemesia cana bolander), and exposed volcanic rocks were studied. Spectral data from grating position 3 (tree mode) were selected from 25 ground positions for analysis by Principal Factor Analysis (PFA). In this grating position, as many as six factors were identified as significant in contributing to spectral structure. Channels 74 through 84 (tree mode) best characterized between-class differences. Other channels were identified as nondiscriminating and as associated with such errors as excessive atmospheric absorption and grating positin changes. The test site was relatively simple with the two species (A. tridentata and A. cana) representing nearly 95% of biomass and with only two mineral backgrounds, a montmorillonitic soil and volcanic rocks. If, as in this study, six factors of spectral structure can be extracted from a single grating position from data acquired over a simple vegetation community, then AIS data must be considered rich in information-gathering potential.

  12. AI techniques in geomagnetic storm forecasting

    NASA Astrophysics Data System (ADS)

    Lundstedt, Henrik

    This review deals with how geomagnetic storms can be predicted with the use of Artificial Intelligence (AI) techniques. Today many different Al techniques have been developed, such as symbolic systems (expert and fuzzy systems) and connectionism systems (neural networks). Even integrations of AI techniques exist, so called Intelligent Hybrid Systems (IHS). These systems are capable of learning the mathematical functions underlying the operation of non-linear dynamic systems and also to explain the knowledge they have learned. Very few such powerful systems exist at present. Two such examples are the Magnetospheric Specification Forecast Model of Rice University and the Lund Space Weather Model of Lund University. Various attempts to predict geomagnetic storms on long to short-term are reviewed in this article. Predictions of a month to days ahead most often use solar data as input. The first SOHO data are now available. Due to the high temporal and spatial resolution new solar physics have been revealed. These SOHO data might lead to a breakthrough in these predictions. Predictions hours ahead and shorter rely on real-time solar wind data. WIND gives us real-time data for only part of the day. However, with the launch of the ACE spacecraft in 1997, real-time data during 24 hours will be available. That might lead to the second breakthrough for predictions of geomagnetic storms.

  13. Can apolipoproteins and complement factors be biomarkers of Alzheimer's disease?

    PubMed

    Manral, Pallavi; Sharma, Pratibha; Hariprasad, Gururao; Chandralekha; Tripathi, Manjari; Srinivasan, Alagiri

    2012-10-01

    Alzheimer's disease is the most common cause of dementia in elderly persons. Quick diagnosis of Alzheimer's disease will allow treatments that may help slow its progression. The correlation between cerebrospinal fluid (CSF) parameters and progression of Alzheimer's disease is higher than and independent of other risk factors. We have compared sixteen CSF samples of clinically diagnosed Alzheimer's disease patients with non demented subjects using proteomics approach. Apolipoprotein E, apolipoprotein J, complement C4b, hemopexin and complement factor B were identified as differentially expressed proteins. Pathway analyses show that these proteins have interacting partners in Alzheimer's and apoptotic pathways. The possible roles of these proteins in relation to the disease are discussed. PMID:22631439

  14. A Systematic Investigation of Structure/Function Requirements for the Apolipoprotein A-I/Lecithin Cholesterol Acyltransferase Interaction Loop of High-density Lipoprotein.

    PubMed

    Gu, Xiaodong; Wu, Zhiping; Huang, Ying; Wagner, Matthew A; Baleanu-Gogonea, Camelia; Mehl, Ryan A; Buffa, Jennifer A; DiDonato, Anthony J; Hazen, Leah B; Fox, Paul L; Gogonea, Valentin; Parks, John S; DiDonato, Joseph A; Hazen, Stanley L

    2016-03-18

    The interaction of lecithin-cholesterol acyltransferase (LCAT) with apolipoprotein A-I (apoA-I) plays a critical role in high-density lipoprotein (HDL) maturation. We previously identified a highly solvent-exposed apoA-I loop domain (Leu(159)-Leu(170)) in nascent HDL, the so-called "solar flare" (SF) region, and proposed that it serves as an LCAT docking site (Wu, Z., Wagner, M. A., Zheng, L., Parks, J. S., Shy, J. M., 3rd, Smith, J. D., Gogonea, V., and Hazen, S. L. (2007) Nat. Struct. Mol. Biol. 14, 861-868). The stability and role of the SF domain of apoA-I in supporting HDL binding and activation of LCAT are debated. Here we show by site-directed mutagenesis that multiple residues within the SF region (Pro(165), Tyr(166), Ser(167), and Asp(168)) of apoA-I are critical for both LCAT binding to HDL and LCAT catalytic efficiency. The critical role for possible hydrogen bond interaction at apoA-I Tyr(166) was further supported using reconstituted HDL generated from apoA-I mutants (Tyr(166) → Glu or Asn), which showed preservation in both LCAT binding affinity and catalytic efficiency. Moreover, the in vivo functional significance of NO2-Tyr(166)-apoA-I, a specific post-translational modification on apoA-I that is abundant within human atherosclerotic plaque, was further investigated by using the recombinant protein generated from E. coli containing a mutated orthogonal tRNA synthetase/tRNACUA pair enabling site-specific insertion of the unnatural amino acid into apoA-I. NO2-Tyr(166)-apoA-I, after subcutaneous injection into hLCAT(Tg/Tg), apoA-I(-/-) mice, showed impaired LCAT activation in vivo, with significant reduction in HDL cholesteryl ester formation. The present results thus identify multiple structural features within the solvent-exposed SF region of apoA-I of nascent HDL essential for optimal LCAT binding and catalytic efficiency. PMID:26797122

  15. Quantifying the tracking capability of space-based AIS systems

    NASA Astrophysics Data System (ADS)

    Skauen, Andreas Nordmo

    2016-01-01

    The Norwegian Defence Research Establishment (FFI) has operated three Automatic Identification System (AIS) receivers in space. Two are on dedicated nano-satellites, AISSat-1 and AISSat-2. The third, the NORAIS Receiver, was installed on the International Space Station. A general method for calculating the upper bound on the tracking capability of a space-based AIS system has been developed and the results from the algorithm applied to AISSat-1 and the NORAIS Receiver individually. In addition, a constellation of AISSat-1 and AISSat-2 is presented. The tracking capability is defined as the probability of re-detecting ships as they move around the globe and is explained to represent and upper bound on a space-based AIS system performance. AISSat-1 and AISSat-2 operates on the nominal AIS1 and AIS2 channels, while the NORAIS Receiver data used are from operations on the dedicated space AIS channels, AIS3 and AIS4. The improved tracking capability of operations on the space AIS channels is presented.

  16. cDNA sequences of two apolipoproteins from lamprey

    SciTech Connect

    Pontes, M.; Xu, X.; Graham, D.; Riley, M.; Doolittle, R.F.

    1987-03-24

    The messages for two small but abundant apolipoproteins found in lamprey blood plasma were cloned with the aid of oligonucleotide probes based on amino-terminal sequences. In both cases, numerous clones were identified in a lamprey liver cDNA library, consistent with the great abundance of these proteins in lamprey blood. One of the cDNAs (LAL1) has a coding region of 105 amino acids that corresponds to a 21-residue signal peptide, a putative 8-residue propeptide, and the 76-residue mature protein found in blood. The other cDNA (LAL2) codes for a total of 191 residues, the first 23 of which constitute a signal peptide. The two proteins, which occur in the high-density lipoprotein fraction of ultracentrifuged plasma, have amino acid compositions similar to those of apolipoproteins found in mammalian blood; computer analysis indicates that the sequences are largely helix-permissive. When the sequences were searched against an amino acid sequence data base, rat apolipoprotein IV was the best matching candidate in both cases. Although a reasonable alignment can be made with that sequence and LAL1, definitive assignment of the two lamprey proteins to typical mammalian classes cannot be made at this point.

  17. Conformational flexibility in the apolipoprotein E amino-terminal domain structure determined from three new crystal forms: implications for lipid binding.

    PubMed Central

    Segelke, B. W.; Forstner, M.; Knapp, M.; Trakhanov, S. D.; Parkin, S.; Newhouse, Y. M.; Bellamy, H. D.; Weisgraber, K. H.; Rupp, B.

    2000-01-01

    An amino-terminal fragment of human apolipoprotein E3 (residues 1-165) has been expressed and crystallized in three different crystal forms under similar crystallization conditions. One crystal form has nearly identical cell dimensions to the previously reported orthorhombic (P2(1)2(1)2(1)) crystal form of the amino-terminal 22 kDa fragment of apolipoprotein E (residues 1-191). A second orthorhombic crystal form (P2(1)2(1)2(1) with cell dimensions differing from the first form) and a trigonal (P3(1)21) crystal form were also characterized. The structures of the first orthorhombic and the trigonal form were determined by seleno-methionine multiwavelength anomalous dispersion, and the structure of the second orthorhombic form was determined by molecular replacement using the structure from the trigonal form as a search model. A combination of modern experimental and computational techniques provided high-quality electron-density maps, which revealed new features of the apolipoprotein E structure, including an unambiguously traced loop connecting helices 2 and 3 in the four-helix bundle and a number of multiconformation side chains. The three crystal forms contain a common intermolecular, antiparallel packing arrangement. The electrostatic complimentarity observed in this antiparallel packing resembles the interaction of apolipoprotein E with the monoclonal antibody 2E8 and the low density lipoprotein receptor. Superposition of the model structures from all three crystal forms reveals flexibility and pronounced kinks in helices near one end of the four-helix bundle. This mobility at one end of the molecule provides new insights into the structural changes in apolipoprotein E that occur with lipid association. PMID:10850798

  18. Apolipoprotein D is involved in the mechanisms regulating protection from oxidative stress

    PubMed Central

    Ganfornina, Maria D.; Do Carmo, Sonia; Lora, Jose M.; Torres-Schumann, Sonia; Vogel, Marci; Allhorn, Maria; González, Constancio; Bastiani, Michael J.; Rassart, Eric; Sanchez, Diego

    2008-01-01

    Summary Many nervous system pathologies are associated with increased levels of Apolipoprotein D (ApoD), a lipocalin also expressed during normal development and aging. An ApoD homologous gene in Drosophila, Glial Lazarillo, regulates resistance to stress, and neurodegeneration in the aging brain. Here we study for the first time the protecting potential of ApoD in a vertebrate model organism. Loss of mouse ApoD function increases the sensitivity to oxidative stress and the levels of brain lipid peroxidation, and impairs locomotor and learning abilities. Human ApoD over-expression in the mouse brain produces opposite effects, increasing survival and preventing the raise of brain lipid peroxides after oxidant treatment. These observations, together with its transcriptional up-regulation in the brain upon oxidative insult, identify ApoD as an acute response protein with a protective and therefore beneficial function mediated by the control of peroxidated lipids. PMID:18419796

  19. Apolipoprotein E and Sex Bias in Cerebrovascular Aging of Men and Mice.

    PubMed

    Finch, Caleb E; Shams, Sara

    2016-09-01

    Alzheimer disease (AD) research has mainly focused on neurodegenerative processes associated with the classic neuropathologic markers of senile plaques and neurofibrillary tangles. Additionally, cerebrovascular contributions to dementia are increasingly recognized, particularly from cerebral small vessel disease (SVD). Remarkably, in AD brains, the apolipoprotein E (ApoE) ɛ4 allele shows male excess for cerebral microbleeds (CMBs), a marker of SVD, which is opposite to the female excess of plaques and tangles. Mouse transgenic models add further complexities to sex-ApoE ɛ4 allele interactions, with female excess of both CMBs and brain amyloid. We conclude that brain aging and AD pathogenesis cannot be understood in humans without addressing major gaps in the extent of sex differences in cerebrovascular pathology. PMID:27546867

  20. Apolipoprotein E and Apolipoprotein E Receptors: Normal Biology and Roles in Alzheimer Disease

    PubMed Central

    Holtzman, David M.; Herz, Joachim; Bu, Guojun

    2012-01-01

    Apolipoprotein E (APOE) genotype is the major genetic risk factor for Alzheimer disease (AD); the ε4 allele increases risk and the ε2 allele is protective. In the central nervous system (CNS), apoE is produced by glial cells, is present in high-density-like lipoproteins, interacts with several receptors that are members of the low-density lipoprotein receptor (LDLR) family, and is a protein that binds to the amyloid-β (Aβ) peptide. There are a variety of mechanisms by which apoE isoform may influence risk for AD. There is substantial evidence that differential effects of apoE isoform on AD risk are influenced by the ability of apoE to affect Aβ aggregation and clearance in the brain. Other mechanisms are also likely to play a role in the ability of apoE to influence CNS function as well as AD, including effects on synaptic plasticity, cell signaling, lipid transport and metabolism, and neuroinflammation. ApoE receptors, including LDLRs, Apoer2, very low-density lipoprotein receptors (VLDLRs), and lipoprotein receptor-related protein 1 (LRP1) appear to influence both the CNS effects of apoE as well as Aβ metabolism and toxicity. Therapeutic strategies based on apoE and apoE receptors may include influencing apoE/Aβ interactions, apoE structure, apoE lipidation, LDLR receptor family member function, and signaling. Understanding the normal and disease-related biology connecting apoE, apoE receptors, and AD is likely to provide novel insights into AD pathogenesis and treatment. PMID:22393530

  1. AI tools in computer based problem solving

    NASA Technical Reports Server (NTRS)

    Beane, Arthur J.

    1988-01-01

    The use of computers to solve value oriented, deterministic, algorithmic problems, has evolved a structured life cycle model of the software process. The symbolic processing techniques used, primarily in research, for solving nondeterministic problems, and those for which an algorithmic solution is unknown, have evolved a different model, much less structured. Traditionally, the two approaches have been used completely independently. With the advent of low cost, high performance 32 bit workstations executing identical software with large minicomputers and mainframes, it became possible to begin to merge both models into a single extended model of computer problem solving. The implementation of such an extended model on a VAX family of micro/mini/mainframe systems is described. Examples in both development and deployment of applications involving a blending of AI and traditional techniques are given.

  2. Application of AIS Technology to Forest Mapping

    NASA Technical Reports Server (NTRS)

    Yool, S. R.; Star, J. L.

    1985-01-01

    Concerns about environmental effects of large scale deforestation have prompted efforts to map forests over large areas using various remote sensing data and image processing techniques. Basic research on the spectral characteristics of forest vegetation are required to form a basis for development of new techniques, and for image interpretation. Examination of LANDSAT data and image processing algorithms over a portion of boreal forest have demonstrated the complexity of relations between the various expressions of forest canopies, environmental variability, and the relative capacities of different image processing algorithms to achieve high classification accuracies under these conditions. Airborne Imaging Spectrometer (AIS) data may in part provide the means to interpret the responses of standard data and techniques to the vegetation based on its relatively high spectral resolution.

  3. The Cardioprotective Protein Apolipoprotein A1 Promotes Potent Anti-tumorigenic Effects*♦

    PubMed Central

    Zamanian-Daryoush, Maryam; Lindner, Daniel; Tallant, Thomas C.; Wang, Zeneng; Buffa, Jennifer; Klipfell, Elizabeth; Parker, Yvonne; Hatala, Denise; Parsons-Wingerter, Patricia; Rayman, Pat; Yusufishaq, Mohamed Sharif S.; Fisher, Edward A.; Smith, Jonathan D.; Finke, Jim; DiDonato, Joseph A.; Hazen, Stanley L.

    2013-01-01

    Here, we show that apolipoprotein A1 (apoA1), the major protein component of high density lipoprotein (HDL), through both innate and adaptive immune processes, potently suppresses tumor growth and metastasis in multiple animal tumor models, including the aggressive B16F10L murine malignant melanoma model. Mice expressing the human apoA1 transgene (A1Tg) exhibited increased infiltration of CD11b+ F4/80+ macrophages with M1, anti-tumor phenotype, reduced tumor burden and metastasis, and enhanced survival. In contrast, apoA1-deficient (A1KO) mice showed markedly heightened tumor growth and reduced survival. Injection of human apoA1 into A1KO mice inoculated with tumor cells remarkably reduced both tumor growth and metastasis, enhanced survival, and promoted regression of both tumor and metastasis burden when administered following palpable tumor formation and metastasis development. Studies with apolipoprotein A2 revealed the anti-cancer therapeutic effect was specific to apoA1. In vitro studies ruled out substantial direct suppressive effects by apoA1 or HDL on tumor cells. Animal models defective in different aspects of immunity revealed both innate and adaptive arms of immunity contribute to complete apoA1 anti-tumor activity. This study reveals a potent immunomodulatory role for apoA1 in the tumor microenvironment, altering tumor-associated macrophages from a pro-tumor M2 to an anti-tumor M1 phenotype. Use of apoA1 to redirect in vivo elicited tumor-infiltrating macrophages toward tumor rejection may hold benefit as a potential cancer therapeutic. PMID:23720750

  4. AI And Early Vision - Part II

    NASA Astrophysics Data System (ADS)

    Julesz, Bela

    1989-08-01

    A quarter of a century ago I introduced two paradigms into psychology which in the intervening years have had a direct impact on the psychobiology of early vision and an indirect one on artificial intelligence (AI or machine vision). The first, the computer-generated random-dot stereogram (RDS) paradigm (Julesz, 1960) at its very inception posed a strategic question both for AI and neurophysiology. The finding that stereoscopic depth perception (stereopsis) is possible without the many enigmatic cues of monocular form recognition - as assumed previously - demonstrated that stereopsis with its basic problem of finding matches between corresponding random aggregates of dots in the left and right visual fields became ripe for modeling. Indeed, the binocular matching problem of stereopsis opened up an entire field of study, eventually leading to the computational models of David Marr (1982) and his coworkers. The fusion of RDS had an even greater impact on neurophysiologists - including Hubel and Wiesel (1962) - who realized that stereopsis must occur at an early stage, and can be studied easier than form perception. This insight recently culminated in the studies by Gian Poggio (1984) who found binocular-disparity - tuned neurons in the input stage to the visual cortex (layer IVB in V1) in the monkey that were selectively triggered by dynamic RDS. Thus the first paradigm led to a strategic insight: that with stereoscopic vision there is no camouflage, and as such was advantageous for our primate ancestors to evolve the cortical machinery of stereoscopic vision to capture camouflaged prey (insects) at a standstill. Amazingly, although stereopsis evolved relatively late in primates, it captured the very input stages of the visual cortex. (For a detailed review, see Julesz, 1986a)

  5. The isolation and partial characterization of the serum lipoproteins and apolipoproteins of the rainbow trout.

    PubMed Central

    Skinner, E R; Rogie, A

    1978-01-01

    1. VLD (very-low-density), LD (low-density) and HD (high-density) lipoproteins were isolated from the serum of trout (Salmo gairdneri Richardson). 2. Each lipoprotein class resembled that of the human in immunological reactivity, electrophoretic behaviour and appearance in the electron microscope. Trout LD lipoprotein, however, was of greater density than human LD lipoprotein. 3. The trout lipoproteins have lipid compositions which are similar to those of the corresponding human components, except for their high contents of long-chain unsaturated fatty acids. 4. HD and LD lipoproteins were immunologically non-identical, whereas LD lipoproteins possessed antigenic determinants in common with VLD lipoproteins. 5. VLD and HD lipoproteins each contained at least seven different apoproteins, whereas LD liprotein was composed largely of a single apoprotein which resembled human apolipoprotein B. 6. At least one, and possibly three, apoprotein of trout HD lipoprotein showed features which resemble human apoprotein A-1.7. The broad similarity between the trout and human lipoprotein systems suggests that both arose from common ancestral genes early in evolutionary history. Images Fig. 2. Fig. 3. PLATE 1 Fig. 4. Fig. 5. Fig. 6. Fig. 8. PMID:100102

  6. Polarized secretion of newly synthesized lipoproteins by the Caco-2 human intestinal cell line

    SciTech Connect

    Traber, M.G.; Kayden, H.J.; Rindler, M.J.

    1987-11-01

    Lipoprotein secretion by Caco-2 cells, a human intestinal cell line, was studied in cells grown on inserts containing a Millipore filter (0.45 micron), separating secretory products from the apical and basolateral membranes into separate chambers. Under these conditions, as observed by electron microscopy, the cells formed a monolayer of columnar epithelial cells with microvilli on the apical surface and tight junctions between cells. The electrical resistances of the cell monolayers were 250-500 ohms/cm2. Both /sup 14/C-labeled lipids and /sup 35/S-labeled proteins were used to assess lipoprotein secretion. After a 24-hr incubation with (/sup 14/C)oleic acid, 60-80% of the secreted triglyceride (TG) was in the basolateral chamber; 40% of the TG was present in the d less than 1.006 g/ml (chylomicron + VLDL) fraction and 50% in the 1.006 less than d less than 1.063 g/ml (LDL) fraction. After a 4-hr incubation with (/sup 35/S)methionine, apolipoproteins were found to be major secretory products with 75-100% secreted to the basolateral chamber. Apolipoproteins B-100, B-48, E, A-I, A-IV, and C-III were identified by immunoprecipitation. The d less than 1.006 g/ml fraction was found to contain all of the major apolipoproteins, while the LDL fraction contained primarily apoB-100 and apoE; the HDL (1.063 less than d less than 1.21 g/ml) fraction principally contained apoA-I and apoA-IV. Mn-heparin precipitated all of the (/sup 35/S)methionine-labeled apoB-100 and B-48 and a majority of the other apolipoproteins, and 80% of the (/sup 14/C)oleic acid-labeled triglyceride, but only 15% of the phospholipid, demonstrating that Caco-2 cells secrete triglyceride-rich lipoproteins containing apoB.

  7. Pedagogy and the PC: Trends in the AIS Curriculum

    ERIC Educational Resources Information Center

    Badua, Frank

    2008-01-01

    The author investigated the array of course topics in accounting information systems (AIS), as course syllabi embody. The author (a) used exploratory data analysis to determine the topics that AIS courses most frequently offered and (b) used descriptive statistics and econometric analysis to trace the diversity of course topics through time,…

  8. An Immune Agent for Web-Based AI Course

    ERIC Educational Resources Information Center

    Gong, Tao; Cai, Zixing

    2006-01-01

    To overcome weakness and faults of a web-based e-learning course such as Artificial Intelligence (AI), an immune agent was proposed, simulating a natural immune mechanism against a virus. The immune agent was built on the multi-dimension education agent model and immune algorithm. The web-based AI course was comprised of many files, such as HTML…

  9. The Social Stratification of /aI/ in Tuscaloosa, Alabama.

    ERIC Educational Resources Information Center

    Crane, L. Ben

    This study is a sociolinguistic analysis of the variant pronunciation of /aI/, a selected phonological variable, by white informants in Tuscaloosa, Alabama. Through a purposive sampling procedure, 56 informants were interviewed to determine their pronunciation of /aI/. Informants were ranked according to education, income, and occupation to…

  10. THE CURRENT STATE OF SEMEN STORAGE AND AI TECHNOLOGY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Turkeys are the only commercial livestock species completely dependent upon artificial insemination (AI) for fertile egg production. Given that every breeder hen must be inseminated weekly during egg production, AI is both time and labor-intensive. Methods for the timing, frequency, semen dosage a...

  11. Integrating the Wall Street Journal into AIS Courses

    ERIC Educational Resources Information Center

    Kohlmeyer, James M., III

    2008-01-01

    While it is important for accounting information systems (AIS) students to understand computer technology, internal controls and business processes, such knowledge is of little use without reference to appropriate contexts. Integrating Wall Street Journal (WSJ) readings and discussions into AIS classes can enrich learning by stimulating…

  12. Ada in AI or AI in Ada. On developing a rationale for integration

    NASA Technical Reports Server (NTRS)

    Collard, Philippe E.; Goforth, Andre

    1988-01-01

    The use of Ada as an Artificial Intelligence (AI) language is gaining interest in the NASA Community, i.e., by parties who have a need to deploy Knowledge Based-Systems (KBS) compatible with the use of Ada as the software standard for the Space Station. A fair number of KBS and pseudo-KBS implementations in Ada exist today. Currently, no widely used guidelines exist to compare and evaluate these with one another. The lack of guidelines illustrates a fundamental problem inherent in trying to compare and evaluate implementations of any sort in languages that are procedural or imperative in style, such as Ada, with those in languages that are functional in style, such as Lisp. Discussed are the strengths and weakness of using Ada as an AI language and a preliminary analysis provided of factors needed for the development of criteria for the integration of these two families of languages and the environments in which they are implemented. The intent for developing such criteria is to have a logical rationale that may be used to guide the development of Ada tools and methodology to support KBS requirements, and to identify those AI technology components that may most readily and effectively be deployed in Ada.

  13. Apolipoprotein L1 Variant Associated with Increased Susceptibility to Trypanosome Infection

    PubMed Central

    Cuypers, Bart; Lecordier, Laurence; Meehan, Conor J.; Van den Broeck, Frederik; Imamura, Hideo; Büscher, Philippe; Dujardin, Jean-Claude; Laukens, Kris; Schnaufer, Achim; Dewar, Caroline; Lewis, Michael; Balmer, Oliver; Azurago, Thomas; Kyei-Faried, Sardick; Ohene, Sally-Ann; Duah, Boateng; Homiah, Prince; Mensah, Ebenezer Kofi; Anleah, Francis; Franco, Jose Ramon; Pays, Etienne

    2016-01-01

    ABSTRACT African trypanosomes, except Trypanosoma brucei gambiense and Trypanosoma brucei rhodesiense, which cause human African trypanosomiasis, are lysed by the human serum protein apolipoprotein L1 (ApoL1). These two subspecies can resist human ApoL1 because they express the serum resistance proteins T. b. gambiense glycoprotein (TgsGP) and serum resistance-associated protein (SRA), respectively. Whereas in T. b. rhodesiense, SRA is necessary and sufficient to inhibit ApoL1, in T. b. gambiense, TgsGP cannot protect against high ApoL1 uptake, so different additional mechanisms contribute to limit this uptake. Here we report a complex interplay between trypanosomes and an ApoL1 variant, revealing important insights into innate human immunity against these parasites. Using whole-genome sequencing, we characterized an atypical T. b. gambiense infection in a patient in Ghana. We show that the infecting trypanosome has diverged from the classical T. b. gambiense strains and lacks the TgsGP defense mechanism against human serum. By sequencing the ApoL1 gene of the patient and subsequent in vitro mutagenesis experiments, we demonstrate that a homozygous missense substitution (N264K) in the membrane-addressing domain of this ApoL1 variant knocks down the trypanolytic activity, allowing the trypanosome to avoid ApoL1-mediated immunity. PMID:27073096

  14. A phospholipid-apolipoproteinA-I nanoparticle containing Amphotericin B as a drug delivery platform with cell membrane protective properties

    PubMed Central

    Burgess, Braydon L.; Cavigiolio, Giorgio; Fannucchi, Michelle V.; Illek, Beate; Forte, Trudy M.; Oda, Michael N.

    2010-01-01

    Amphotericin B (AMB), a potent antifungal agent, has been employed as an inhalable therapy for pulmonary fungal infections. We recently described a novel nano-sized delivery vehicle composed of phospholipid (PL) and apolipoprotein A-I, NanoDisk (ND), to which we added AMB as a payload (ND-AMB). The goal of the present study was to evaluate whether ND-AMB, compared to other formulations, preserves lung cell integrity in vitro, as AMB can be toxic to mammalian cells and reduce lung function when inhaled. Epithelial integrity was assessed by measuring K+ ion flux across a model airway epithelium, Calu-3 cells. In this assay ND-AMB was at least 8-fold less disruptive than AMB/deoxycholate (DOC). Cell viability studies confirmed this observation. Unexpectedly, the ND vehicle restored the integrity of a membrane compromised by prior exposure to AMB. An alternative formulation of ND-AMB containing a high load of AMB per ND was not protective, suggesting that ND with a low ratio of AMB to PL can sequester additional AMB from membranes. ND-AMB also protected HepG2 cells from the cytotoxicity of AMB, as determined by cellular viability and lactate dehydrogenase (LDH) levels. This study suggests that ND-AMB may be safe for administration via inhalation and reveals a unique activity whereby ND-AMB protects lung epithelial membranes from AMB toxicity. PMID:20696226

  15. β-COP as a Component of Transport Vesicles for HDL Apolipoprotein-Mediated Cholesterol Exocytosis

    PubMed Central

    Ma, Weilie; Lin, Margarita; Ding, Hang; Lin, Guorong; Zhang, Zhizhen

    2016-01-01

    Objective HDL and its apolipoproteins protect against atherosclerotic disease partly by removing excess cholesterol from macrophage foam cells. But the underlying mechanisms of cholesterol clearance are still not well defined. We investigated roles of vesicle trafficking of coatomer β-COP in delivering cholesterol to the cell surface during apoA-1 and apoE-mediated lipid efflux from fibroblasts and THP-1 macrophages. Methods shRNA knockout, confocal and electron microscopy and biochemical analysis were used to investigate the roles of β-COP in apolipoprotein-mediated cholesterol efflux in fibroblasts and THP-1 macrophages. Results We showed that β-COP knockdown by lentiviral shRNA resulted in reduced apoA-1-mediated cholesterol efflux, while increased cholesterol accumulation and formation of larger vesicles were observed in THP-1 macrophages by laser scanning confocal microscopy. Immunogold electron microscopy showed that β-COP appeared on the membrane protrusion complexes and colocalized with apoA-1 or apoE during cholesterol efflux. This was associated with releasing heterogeneous sizes of small particles into the culture media of THP-1 macrophage. Western blotting also showed that apoA-1 promotes β-COP translocation to the cell membrane and secretion into culture media, in which a total of 17 proteins were identified by proteomics. Moreover, β-COP exclusively associated with human plasma HDL fractions. Conclusion ApoA-1 and apoE promoted transport vesicles consisting of β-COP and other candidate proteins to exocytose cholesterol, forming the protrusion complexes on cell surface, which were then released from the cell membrane as small particles to media. PMID:26986486

  16. Reduced Apolipoprotein Glycosylation in Patients with the Metabolic Syndrome

    PubMed Central

    Savinova, Olga V.; Fillaus, Kristi; Jing, Linhong; Harris, William S.; Shearer, Gregory C.

    2014-01-01

    Objective The purpose of this study was to compare the apolipoprotein composition of the three major lipoprotein classes in patients with metabolic syndrome to healthy controls. Methods Very low density (VLDL), intermediate/low density (IDL/LDL, hereafter LDL), and high density lipoproteins (HDL) fractions were isolated from plasma of 56 metabolic syndrome subjects and from 14 age-sex matched healthy volunteers. The apolipoprotein content of fractions was analyzed by one-dimensional (1D) gel electrophoresis with confirmation by a combination of mass spectrometry and biochemical assays. Results Metabolic syndrome patients differed from healthy controls in the following ways: (1) total plasma - apoA1 was lower, whereas apoB, apoC2, apoC3, and apoE were higher; (2) VLDL - apoB, apoC3, and apoE were increased; (3) LDL - apoC3 was increased, (4) HDL -associated constitutive serum amyloid A protein (SAA4) was reduced (p<0.05 vs. controls for all). In patients with metabolic syndrome, the most extensively glycosylated (di-sialylated) isoform of apoC3 was reduced in VLDL, LDL, and HDL fractions by 17%, 30%, and 25%, respectively (p<0.01 vs. controls for all). Similarly, the glycosylated isoform of apoE was reduced in VLDL, LDL, and HDL fractions by 15%, 26%, and 37% (p<0.01 vs. controls for all). Finally, glycosylated isoform of SAA4 in HDL fraction was 42% lower in patients with metabolic syndrome compared with controls (p<0.001). Conclusions Patients with metabolic syndrome displayed several changes in plasma apolipoprotein composition consistent with hypertriglyceridemia and low HDL cholesterol levels. Reduced glycosylation of apoC3, apoE and SAA4 are novel findings, the pathophysiological consequences of which remain to be determined. PMID:25118169

  17. Apolipoprotein gene involved in lipid metabolism

    DOEpatents

    Rubin, Edward; Pennacchio, Len A.

    2007-07-03

    Methods and materials for studying the effects of a newly identified human gene, APOAV, and the corresponding mouse gene apoAV. The sequences of the genes are given, and transgenic animals which either contain the gene or have the endogenous gene knocked out are described. In addition, single nucleotide polymorphisms (SNPs) in the gene are described and characterized. It is demonstrated that certain SNPs are associated with diseases involving lipids and triglycerides and other metabolic diseases. These SNPs may be used alone or with SNPs from other genes to study individual risk factors. Methods for intervention in lipid diseases, including the screening of drugs to treat lipid-related or diabetic diseases are also disclosed.

  18. An ultrasensitive electrochemical immunosensor for apolipoprotein E4 based on fractal nanostructures and enzyme amplification.

    PubMed

    Liu, Yibiao; Xu, Li-Ping; Wang, Shuqi; Yang, Weizhao; Wen, Yongqiang; Zhang, Xueji

    2015-09-15

    Human apolipoprotein E4 (APOE4) is a major risk factor for Alzheimer's disease (AD) and can greatly increase the morbidity. In this work, an ultrasensitive sandwich-type electrochemical immunosensor for the quantitative detection of APOE4 was designed based on fractal gold (FracAu) nanostructures and enzyme amplification. The FracAu nanostructures were directly electrodeposited by hydrogen tetrachloroaurate (HAuCl4) on polyelectrolytes modified indium tin oxide (ITO) electrode. The sensing performances of the modified interface were investigated by cyclic voltammetry (CV). After functionalization with HRP-labeled APOE4 antibody, the human APOE4 could be detected quantitatively by current response. The current response has a linear relationship with the logarithm of human APOE4 concentrations in a range from 1.0 to 10,000.0 ng/mL, with a detection limit of 0.3 ng/mL. The fabricated APOE4 electrochemical immunosensor exhibits strong specificity, high sensitivity, low detection limit and wide linear range. The detection of human APOE4 provides a strong support for the prevention of AD and early-stage warning for those susceptible populations. PMID:25950934

  19. The intravenous injection of oxidized LDL- or Apolipoprotein B100 – Coupled splenocytes promotes Th1 polarization in wildtype and Apolipoprotein E – Deficient mice

    SciTech Connect

    Steinmetz, Martin; Ponnuswamy, Padmapriya; Laurans, Ludivine; Esposito, Bruno; Tedgui, Alain; Mallat, Ziad

    2015-08-14

    Background: Th1 responses in atherosclerosis are mainly associated with the aggravation of atherosclerotic plaques, whereas Th2 responses lead to a less pronounced disease in mouse models. The fixation of antigens on cells by means of ethylene carbodiimide (ECDI), and subsequent injection of these antigen-coupled splenocytes (Ag-SP) to induce tolerance against the attached antigens, has been successfully used to treat murine type 1 diabetes or encephalomyelitis in. We analyzed this approach in a mouse model for atherosclerosis. Methods and results: OTII-transgenic mice that were treated with a single dose of 5 × 10{sup 7} OVA-coupled splenocytes (OVA-SP), had decreased splenocyte proliferation, and lower IFNγ production in vitro upon antigen recall. However, in vivo CD4 cell activation was increased. To try lipoprotein-derived, “atherosclerosis-associated” antigens, we first tested human oxidized LDL. In wild type mice, an increase of IFNγ production upon in vitro recall was detected in the oxLDL-SP group. In Apolipoprotein E − deficient (ApoE−/−) mice that received oxLDL-SP every 5 weeks for 20 weeks, we did not find any difference of atherosclerotic plaque burden, but again increased IFNγ production. To overcome xenogenous limitations, we then examined the effects of mouse Apolipoprotein B100 peptides P3 and P6. ApoB100-SP treatment again promoted a more IFNγ pronounced response upon in vitro recall. Flow cytometry analysis of cytokine secreting spleen cells revealed CD4 positive T cells to be mainly the source for IFNγ. In ApoE−/− mice that were administered ApoB100-SP during 20 weeks, the atherosclerotic plaque burden in aortic roots as well as total aorta was unchanged compared to PBS treated controls. Splenocyte proliferation upon antigen recall was not significantly altered in ApoB100-SP treated ApoE−/− mice. Conclusion: Although we did not observe a relevant anti-atherosclerotic benefit, the treatment with antigen

  20. Identification of the ancestral haplotype for apolipoprotein B suggests an African origin of Homo sapiens sapiens and traces their subsequent migration to Europe and the Pacific

    SciTech Connect

    Rapacz, J.; Hasler-Rapacz, J.O. ); Chen, L.; Wu, Mingjiuan; Schumaker, V.N. ); Butler-Brunner, E.; Butler, R. )

    1991-02-15

    The probable ancestral haplotype for human apolipoprotein B (apoB) has been identified through immunological analysis of chimpanzee and gorilla serum and sequence analysis of their DNA. Moreover, the frequency of this ancestral apoB haplotype among different human populations provides strong support for the African origin of Homo sapiens sapiens and their subsequent migration from Africa to Europe and to the Pacific. The approach used here for the identification of the ancestral human apoB haplotype is likely to be applicable to many other genes.

  1. Identification of the ancestral haplotype for apolipoprotein B suggests an African origin of Homo sapiens sapiens and traces their subsequent migration to Europe and the Pacific.

    PubMed Central

    Rapacz, J; Chen, L; Butler-Brunner, E; Wu, M J; Hasler-Rapacz, J O; Butler, R; Schumaker, V N

    1991-01-01

    The probable ancestral haplotype for human apolipoprotein B (apoB) has been identified through immunological analysis of chimpanzee and gorilla serum and sequence analysis of their DNA. Moreover, the frequency of this ancestral apoB haplotype among different human populations provides strong support for the African origin of Homo sapiens sapiens and their subsequent migration from Africa to Europe and to the Pacific. The approach used here for the identification of the ancestral human apoB haplotype is likely to be applicable to many other genes. PMID:1996341

  2. Identification of the ancestral haplotype for apolipoprotein B suggests an African origin of Homo sapiens sapiens and traces their subsequent migration to Europe and the Pacific.

    PubMed

    Rapacz, J; Chen, L; Butler-Brunner, E; Wu, M J; Hasler-Rapacz, J O; Butler, R; Schumaker, V N

    1991-02-15

    The probable ancestral haplotype for human apolipoprotein B (apoB) has been identified through immunological analysis of chimpanzee and gorilla serum and sequence analysis of their DNA. Moreover, the frequency of this ancestral apoB haplotype among different human populations provides strong support for the African origin of Homo sapiens sapiens and their subsequent migration from Africa to Europe and to the Pacific. The approach used here for the identification of the ancestral human apoB haplotype is likely to be applicable to many other genes. PMID:1996341

  3. Apolipoprotein B-100 Hopkins (arginine sub 4019 yields tryptophan): A new apolipoprotein B-100 variant in a family with premature atherosclerosis and hyperapobetalipoproteinemia

    SciTech Connect

    Ladias, J.A.A.; Kwiterovich, P.O. Jr.; Smith, H.H.; Miller, M.; Bachorik, P.S.; Antonarakis, S.E. ); Forte, T. ); Lusis, A.J. )

    1989-10-13

    A 43-year-old woman with severe coronary artery disease and hyperapobetalipoproteinemia was heterozygous for an abnormal Msp I apolipoprotein B (APOB) gene fragment because of the absence of the Msp I site around codon 4046 in exon 29 of the APOB gene. Using the polymerase chain reaction technique, 134 base pairs containing the mutant Msp I site were amplified, cloned, and sequenced. The mutation was a C to T transition, substituting tryptophan for arginine at amino acid position 4019 of the mature ApoB-100 protein. Seven relatives of the proband has the same mutation, which has been called ApoB-100 Hopkins. Only three of seven relatives with the mutation had hyperapobetalipoproteinemia. Mutant low-density lipoprotein (LDL) was bound and degraded to a greater extent than normal LDL in cultured human fibroblasts. In conclusion, a new mutation, ApoB-100 Hopkins, was not linked to the hyperapobetalipoproteinemia phenotype, which also was segregating in this family. The increased affinity of this mutant LDL for the LDL receptor may be due to a specific effect of ApoB-100 Hopkins or to altered LDL size and composition.

  4. Amphotericin B induced interdigitation of apolipoprotein stabilized nanodisk bilayers

    SciTech Connect

    Nguyen, T; Weers, P M; Sulchek, T; Hoeprich, P D; Ryan, R O

    2006-12-07

    Amphotericin B nanodisks (AMB-ND) are ternary complexes of AMB, phospholipid (PL) and apolipoprotein organized as discrete nanometer scale disk-shaped bilayers. In gel filtration chromatography experiments, empty ND lacking AMB elute as a single population of particles with a molecular weight in the range of 200 kDa. AMB-ND formulated at a 4:1 PL:AMB weight ratio, separated into two peaks. Peak 1 eluted at the position of control ND lacking AMB while the second peak, containing all of the AMB present in the original sample, eluted in the void volume. When ND prepared with increased AMB (1:1 phospholipid:AMB molar ratio) were subjected to gel filtration chromatography, an increased proportion of phospholipid and apolipoprotein were recovered in the void volume with the AMB. Prior to gel filtration the AMB-ND sample could be passed through a 0.22 {micro}m filter without loss of AMB while the voided material was lost. Native gel electrophoresis studies corroborated the gel permeation chromatography data. Far UV circular dichroism analyses revealed that apoA-I associated with AMB-ND denatures at a lower guanidine HCl concentration than apoA-I associated with ND lacking AMB. Atomic force microscopy revealed that AMB induces compression of the ND bilayer thickness consistent with bilayer interdigitation, a phenomenon that is likely related to the ability of AMB to induce pore formation in susceptible membranes.

  5. Apolipoprotein E Related Co-Morbidities and Alzheimer's Disease.

    PubMed

    Singhrao, Sim K; Harding, Alice; Chukkapalli, Sasanka; Olsen, Ingar; Kesavalu, Lakshmyya; Crean, StJohn

    2016-01-01

    The primary goal of advancement in clinical services is to provide a health care system that enhances an individual's quality of life. Incidence of diabetes mellitus, cardiovascular disease, and associated dementia coupled with the advancing age of the population, have led to an increase in the worldwide challenge to the healthcare system. In order to overcome these challenges, prior knowledge of common, reliable risk factors and their effectors is essential. Oral health constitutes one such relatively unexplored but indispensable risk factor for aforementioned co-morbidities, in the form of poor oral hygiene and tooth loss during aging. Behavioral traits such as low education, smoking, poor diet, neglect of oral health, lack of exercise, and hypertension are few of the risk factors that are shared commonly among these conditions. In addition, common genetic susceptibility traits such as the apolipoprotein E gene, together with an individual's lifestyle can also influence the development of co-morbidities such as periodontitis, atherosclerosis/stroke, diabetes, and Alzheimer's disease. This review specifically addresses the susceptibility of apolipoprotein E gene allele 4 as the plausible commonality for the etiology of co-morbidities that eventually result from periodontal diseases and ultimately progress to dementia. PMID:26923007

  6. Amphotericin B induces interdigitation of apolipoprotein stabilized nanodisk bilayers

    PubMed Central

    Nguyen, Thanh-Son; Weers, Paul M.M.; Raussens, Vincent; Wang, Zhen; Ren, Gang; Sulchek, Todd; Hoeprich, Paul D.; Ryan, and Robert O.

    2008-01-01

    Amphotericin B nanodisks (AMB-ND) are ternary complexes of AMB, phospholipid and apolipoprotein organized as discrete nanometer scale disk-shaped bilayers. In gel filtration chromatography experiments, empty ND lacking AMB elute as a single population of particles with a molecular weight in the range of 200 kDa. AMB-ND formulated at a 4:1 phospholipid:AMB weight ratio separated into two peaks. One peak eluted at the position of control ND lacking AMB while the second peak, containing all of the AMB present in the original sample, eluted in the void volume. When ND prepared with increased AMB were subjected to gel filtration chromatography an increased proportion of phospholipid and apolipoprotein was recovered in the void volume with AMB. Native gradient gel electrophoresis corroborated the gel filtration chromatography data and electron microscopy studies revealed an AMB concentration dependent heterogeneity in ND particle size. Stability studies revealed that introduction of AMB into ND decreases the ability of apoA-I to resist denaturation. Atomic force microscopy experiments showed that AMB induces compression of ND bilayer thickness while infrared spectroscopy analysis revealed the presence of AMB does not induce extreme lipid disorder or alter the mean angle of the molecular axis along fatty acyl chain of ND phospholipids. Taken together the results are consistent with AMB induced bilayer interdigitation, a phenomenon that likely contributes to AMB dependent pore formation in susceptible membranes. PMID:17980702

  7. Tgif1 represses apolipoprotein gene expression in liver

    PubMed Central

    Melhuish, Tiffany A.; Chung, David D.; Bjerke, Glen A.; Wotton, David

    2010-01-01

    Tgif1 (TG-interacting factor) represses gene expression by interaction with general corepressors, and can be recruited to target genes by transforming growth factor beta (TGFβ) activated Smads, or by the retinoid X receptor (RXR). Here we show that Tgif1 interacts with the LXRα nuclear receptor and can repress transcription from a synthetic reporter activated by LXRα. In cultured cells reducing endogenous Tgif1 levels resulted in increased expression of LXRα target genes. To test the in vivo role of Tgif1, we analyzed LXRα dependent gene expression in mice lacking Tgif1. In the livers of Tgif1 null mice, we observed significant derepression of the apolipoprotein genes, Apoa4 and Apoc2, suggesting that Tgif1 is an important in vivo regulator of apolipoprotein gene expression. In contrast, we observed relatively minimal effects on expression of other LXR target genes. This work suggests that Tgif1 can regulate nuclear receptor complexes, in addition to those containing retinoic acid receptors, but also indicates that there is some specificity to which NR target genes are repressed by Tgif1. PMID:20506222

  8. Application of Artificial Intelligence (AI) programming techniques to tactical guidance for fighter aircraft

    NASA Technical Reports Server (NTRS)

    Mcmanus, John W.; Goodrich, Kenneth H.

    1989-01-01

    A research program investigating the use of Artificial Intelligence (AI) programming techniques to aid in the development of a Tactical Decision Generator (TDG) for Within-Visual-Range (WVR) air combat engagements is discussed. The application of AI methods for development and implementation of the TDG is presented. The history of the Adaptive Maneuvering Logic (AML) program is traced and current versions of the (AML) program is traced and current versions of the AML program are compared and contrasted with the TDG system. The Knowledge-Based Systems (KBS) used by the TDG to aid in the decision-making process are outlined and example rules are presented. The results of tests to evaluate the performance of the TDG against a version of AML and against human pilots in the Langley Differential Maneuvering Simulator (DMS) are presented. To date, these results have shown significant performance gains in one-versus-one air combat engagements.

  9. Targeting Apolipoproteins in Magnetic Resonance Imaging

    NASA Astrophysics Data System (ADS)

    Sriram, Renuka; Lagerstedt, Jens O.; Samardzic, Haris; Kreutzer, Ulrike; Petrolova, Jitka; Xie, Hongtao; Kaysen, George A.; Voss, John C.; Desreux, Jean F.; Jue, Thomas

    Maintaining normal physiological homeostasis depends upon a coordinated metabolism of both water-soluble and -insoluble substrates. In humans the body derives these molecules — such as glucose, amino acids, and fatty acids — from complex food matter. Water-soluble substrates can circulate readily in blood, while water-insoluble molecules — such as fatty acid, triacylglycerol, and cholesterol — require ampiphathic carriers to transport them from the site of biosynthesis (liver and intestine) to the target tissue. For fatty acid, albumin serves as the major transporter. For triacylglycerol and cholesterol, however, macromolecular complexes aggregate the hydrophobic molecules into the core and cover the surface with amphiphatic proteins and phospholipids to solubilize the particles in the lymphatic and circulatory systems. These macromolecules belong to a class of proteins, plasma lipoproteins, with specific functions and cellular targets. In the clinic these lipoproteins prognosticate the risk of cardiovascular disease (CVD). Lipoproteins divide usually into five major types: chylomicron, very-low-density lipoprotein (VLDL), intermediate-density lipoprotein (IDL), low-density lipoprotein (LDL), and high-density lipoprotein (HDL). Each lipoprotein type exhibits characteristic density, size, and composition. As implied in the name, the density varies from the low-density chylomicron (<0.95 g/ml) to the high-density HDL (1.2 g/ml). Size also varies. The chylomicron has the largest diameter (75-1,200 nm), and HDL has the smallest (5-12 nm). The physical property variation arises from each lipoprotein's distinct composition. In a chylomicron, cholesterol, triacylglycerol, and phospholipid predominate and constitute about 90% of the particle. Protein constitutes only about 10%. In contrast, the smaller HDL has less cholesterol, triacylglycerol, and phospholipid (65% of the particle) but more protein (over 30%).

  10. Utilizing AI in Temporal, Spatial, and Resource Scheduling

    NASA Technical Reports Server (NTRS)

    Stottler, Richard; Kalton, Annaka; Bell, Aaron

    2006-01-01

    Aurora is a software system enabling the rapid, easy solution of complex scheduling problems involving spatial and temporal constraints among operations and scarce resources (such as equipment, workspace, and human experts). Although developed for use in the International Space Station Processing Facility, Aurora is flexible enough that it can be easily customized for application to other scheduling domains and adapted as the requirements change or become more precisely known over time. Aurora s scheduling module utilizes artificial-intelligence (AI) techniques to make scheduling decisions on the basis of domain knowledge, including knowledge of constraints and their relative importance, interdependencies among operations, and possibly frequent changes in governing schedule requirements. Unlike many other scheduling software systems, Aurora focuses on resource requirements and temporal scheduling in combination. For example, Aurora can accommodate a domain requirement to schedule two subsequent operations to locations adjacent to a shared resource. The graphical interface allows the user to quickly visualize the schedule and perform changes reflecting additional knowledge or alterations in the situation. For example, the user might drag the activity corresponding to the start of operations to reflect a late delivery.

  11. AI and simulation: What can they learn from each other

    NASA Technical Reports Server (NTRS)

    Colombano, Silvano P.

    1988-01-01

    Simulation and Artificial Intelligence share a fertile common ground both from a practical and from a conceptual point of view. Strengths and weaknesses of both Knowledge Based System and Modeling and Simulation are examined and three types of systems that combine the strengths of both technologies are discussed. These types of systems are a practical starting point, however, the real strengths of both technologies will be exploited only when they are combined in a common knowledge representation paradigm. From an even deeper conceptual point of view, one might even argue that the ability to reason from a set of facts (i.e., Expert System) is less representative of human reasoning than the ability to make a model of the world, change it as required, and derive conclusions about the expected behavior of world entities. This is a fundamental problem in AI, and Modeling Theory can contribute to its solution. The application of Knowledge Engineering technology to a Distributed Processing Network Simulator (DPNS) is discussed.

  12. Apolipoprotein a1 increases mitochondrial biogenesis through AMP-activated protein kinase.

    PubMed

    Song, Parkyong; Kwon, Yonghoon; Yea, Kyungmoo; Moon, Hyo-Youl; Yoon, Jong Hyuk; Ghim, Jaewang; Hyun, Hyunjung; Kim, Dayea; Koh, Ara; Berggren, Per-Olof; Suh, Pann-Ghill; Ryu, Sung Ho

    2015-09-01

    Apolipoprotein a1, which is a major lipoprotein component of high-density lipoprotein (HDL), was reported to decrease plasma glucose in type 2 diabetes. Although recent studies also have shown that apolipoprotein a1 is involved in triglyceride (TG) metabolism, the mechanisms by which apolipoprotein a1 modulates TG levels remain largely unexplored. Here we demonstrated that apolipoprotein a1 increased mitochondrial DNA and mitochondria contents through sustained AMPK activation in myotubes. This resulted in enhanced fatty acid oxidation and attenuation of free fatty acid-induced insulin resistance features in skeletal muscle. The increment of mitochondria was mediated through induction of transcription factors, such as peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) and nuclear transcription factor 1 (NRF-1). The inhibition of AMPK by a pharmacological agent inhibited the induction of mitochondrial biogenesis. Increase of AMPK phosphorylation by apolipoprotein a1 occurs through activation of upstream kinase LKB1. Finally, we confirmed that scavenger receptor Class B, type 1 (SR-B1) is an important receptor for apolipoprotein a1 in stimulating AMPK pathway and mitochondrial biogenesis. Our study suggests that apolipoprotein a1 can alleviate obesity related metabolic disease by inducing AMPK dependent mitochondrial biogenesis. PMID:25982508

  13. Creating an AI modeling application for designers and developers

    NASA Astrophysics Data System (ADS)

    Houlette, Ryan; Fu, Daniel; Jensen, Randy

    2003-09-01

    Simulation developers often realize an entity's AI by writing a program that exhibits the intended behavior. These behaviors are often the product of design documents written by designers. These individuals, while possessing a vast knowledge of the subject matter, might not have any programming knowledge whatsoever. To address this disconnect between design and subsequent development, we have created an AI application whereby a designer or developer sketches an entity's AI using a graphical "drag and drop" interface to quickly articulate behavior using a UML-like representation of state charts. Aside from the design-level benefits, the application also features a runtime engine that takes the application's data as input along with a simulation or game interface, and makes the AI operational. We discuss our experience in creating such an application for both designer and developer.

  14. Quality measures and assurance for AI (Artificial Intelligence) software

    NASA Technical Reports Server (NTRS)

    Rushby, John

    1988-01-01

    This report is concerned with the application of software quality and evaluation measures to AI software and, more broadly, with the question of quality assurance for AI software. Considered are not only the metrics that attempt to measure some aspect of software quality, but also the methodologies and techniques (such as systematic testing) that attempt to improve some dimension of quality, without necessarily quantifying the extent of the improvement. The report is divided into three parts Part 1 reviews existing software quality measures, i.e., those that have been developed for, and applied to, conventional software. Part 2 considers the characteristics of AI software, the applicability and potential utility of measures and techniques identified in the first part, and reviews those few methods developed specifically for AI software. Part 3 presents an assessment and recommendations for the further exploration of this important area.

  15. Capture and concentration of viral and bacterial foodborne pathogens using apolipoprotein H.

    PubMed

    Almand, Erin A; Goulter, Rebecca M; Jaykus, Lee-Ann

    2016-09-01

    The need for improved pathogen separation and concentration methods to reduce time-to-detection for foodborne pathogens is well recognized. Apolipoprotein H (ApoH) is an acute phase human plasma protein that has been previously shown to interact with viruses, lipopolysaccharides (LPS) and bacterial proteins. The purpose of this study was to determine if ApoH was capable of binding and efficiently capturing two representative human norovirus strains (GI.1 and GII.4), a cultivable surrogate, and four bacterial pathogens (Escherichia coli O157:H7, Listeria monocytogenes, Salmonella enterica serovar Enteritidis, and Staphylococcus aureus). Experiments were carried out using an ApoH-conjugated magnetic bead-based capture followed by pathogen detection using nucleic acid amplification. For all three viruses studied, >10% capture efficiency (<1 Log10 loss in RT-qPCR amplifiable units) was observed. The same capture efficiencies were observed for the bacterial pathogens tested, with the exception of E. coli O157:H7 (approximately 1% capture efficiency, or 2 Log10 loss in CFU equivalents). The efficiency of the capture steps did not vary as a consequence of input target concentration or in the presence of an abundance of background microflora. A complementary plate-based capture assay showed that ApoH bound to a variety of human norovirus virus-like particles. ApoH has the potential to be a broadly reactive ligand for separating and concentrating representative foodborne pathogens, both bacteria and viruses. PMID:27439140

  16. NASA space station automation: AI-based technology review

    NASA Technical Reports Server (NTRS)

    Firschein, O.; Georgeff, M. P.; Park, W.; Neumann, P.; Kautz, W. H.; Levitt, K. N.; Rom, R. J.; Poggio, A. A.

    1985-01-01

    Research and Development projects in automation for the Space Station are discussed. Artificial Intelligence (AI) based automation technologies are planned to enhance crew safety through reduced need for EVA, increase crew productivity through the reduction of routine operations, increase space station autonomy, and augment space station capability through the use of teleoperation and robotics. AI technology will also be developed for the servicing of satellites at the Space Station, system monitoring and diagnosis, space manufacturing, and the assembly of large space structures.

  17. Calibrating AIS images using the surface as a reference

    NASA Technical Reports Server (NTRS)

    Smith, M. O.; Roberts, D. A.; Shipman, H. M.; Adams, J. B.; Willis, S. C.; Gillespie, A. R.

    1987-01-01

    A method of evaluating the initial assumptions and uncertainties of the physical connection between Airborne Imaging Spectrometer (AIS) image data and laboratory/field spectrometer data was tested. The Tuscon AIS-2 image connects to lab reference spectra by an alignment to the image spectral endmembers through a system gain and offset for each band. Images were calibrated to reflectance so as to transform the image into a measure that is independent of the solar radiant flux. This transformation also makes the image spectra directly comparable to data from lab and field spectrometers. A method was tested for calibrating AIS images using the surface as a reference. The surface heterogeneity is defined by lab/field spectral measurements. It was found that the Tuscon AIS-2 image is consistent with each of the initial hypotheses: (1) that the AIS-2 instrument calibration is nearly linear; (2) the spectral variance is caused by sub-pixel mixtures of spectrally distinct materials and shade, and (3) that sub-pixel mixtures can be treated as linear mixtures of pure endmembers. It was also found that the image can be characterized by relatively few endmembers using the AIS-2 spectra.

  18. Aging, age-related macular degeneration, and the response-to-retention of apolipoprotein B-containing lipoproteins

    PubMed Central

    Curcio, Christine A.; Johnson, Mark; Huang, Jiahn-Dar; Rudolf, Martin

    2015-01-01

    The largest risk factor for age-related macular degeneration (ARMD) is advanced age. A prominent age-related change in the human retina is the accumulation of histochemically detectable neutral lipid in normal Bruch’s membrane (BrM) throughout adulthood. This change has the potential to have a major impact on physiology of the retinal pigment epithelium (RPE). It occurs in the same compartment as drusen and basal linear deposit, the pathognomonic extracellular, lipid-containing lesions of ARMD. Here we present evidence from light microscopic histochemistry, ultrastructure, lipid profiling of tissues and isolated lipoproteins, and gene expression analysis that this deposition can be accounted for by esterified cholesterol-rich, apolipoprotein B-containing lipoprotein particles constitutively produced by the RPE. This work collectively allows ARMD lesion formation and its aftermath to be conceptualized as a response to the retention of a sub-endothelial apolipoprotein B lipoprotein, similar to a widely accepted model of atherosclerotic coronary artery disease (CAD) (Tabas et al., 2007). This approach provides a wide knowledge base and sophisticated clinical armamentarium that can be readily exploited for the development of new model systems and the future benefit of ARMD patients. PMID:19698799

  19. 76 FR 44045 - Establishment of the SANE/SART AI/AN Initiative Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-22

    ... of Justice Programs Establishment of the SANE/SART AI/AN Initiative Committee AGENCY: Office for... (SART) American Indian/Alaskan Native (AI/AN) Initiative (``SANE/SART AI/AN Initiative Committee'' or... (FACA), as amended, 5 U.S.C., App. 2. The SANE/SART AI/AN Initiative Committee will provide the...

  20. Application of Artificial Intelligence (AI) Programming Techniques to Tactical Guidance for Fighter Aircraft

    NASA Technical Reports Server (NTRS)

    McManus, John W.; Goodrich, Kenneth H.

    1989-01-01

    A research program investigating the use of Artificial Intelligence (AI) techniques to aid in the development of a Tactical Decision Generator (TDG) for Within-Visual-Range (WVR) air combat engagements is discussed. The application of AI methods for development and implementation of the TDG is presented. The history of the Adaptive Maneuvering Logic (AML) program is traced and current versions of the AML program are compared and contrasted with the TDG system. The Knowledge-Based Systems (KBS) used by the TDG to aid in the decision-making process are outlined in detail and example rules are presented. The results of tests to evaluate the performance of the TDG versus a version of AML and versus human pilots in the Langley Differential Maneuvering Simulator (DMS) are presented. To date, these results have shown significant performance gains in one-versus-one air combat engagements, and the AI-based TDG software has proven to be much easier to modify than the updated FORTRAN AML programs.

  1. Apolipoprotein B100 secretion by cultured ARPE-19 cells is modulated by alteration of cholesterol levels.

    PubMed

    Wu, Tinghuai; Fujihara, Masashi; Tian, Jane; Jovanovic, Miroslava; Grayson, Celene; Cano, Marisol; Gehlbach, Peter; Margaron, Philippe; Handa, James T

    2010-09-01

    Cholesteryl ester rich apolipoprotein B100 (apoB100) lipoproteins accumulate in Bruch's membrane before the development of age-related macular degeneration. It is not known if these lipoproteins come from the circulation or local ocular tissue. Emerging, but incomplete evidence suggests that the retinal pigmented epithelium (RPE) can secrete lipoproteins. The purpose of this investigation was to determine (i) whether human RPE cells synthesize and secrete apoB100, and (ii) whether this secretion is driven by cellular cholesterol, and if so, (iii) whether statins inhibit this response. The established, human derived ARPE-19 cells challenged with 0-0.8 mM oleic acid accumulated cellular cholesterol, but not triglycerides. Oleic acid increased the amount of apoB100 protein recovered from the medium by both western blot analysis and (35) S-radiolabeled immunoprecipitation while negative stain electron microscopy showed lipoprotein-like particles. Of nine statins evaluated, lipophilic statins induced HMG-CoA reductase mRNA expression the most. The lipophilic Cerivastatin (5 μM) reduced cellular cholesterol by 39% and abrogated apoB100 secretion by 3-fold. In contrast, the hydrophilic statin Pravastatin had minimal effect on apoB100 secretion. These data suggest that ARPE-19 cells synthesize and secrete apoB100 lipoproteins, that this secretion is driven by cellular cholesterol, and that statins can inhibit apoB100 secretion by reducing cellular cholesterol. PMID:20598021

  2. Multiple members of the plasminogen-apolipoprotein(a) gene family associated with thrombosis

    SciTech Connect

    Ichinose, Akitada )

    1992-03-31

    Plasminogen and apolipoprotein(a) (apo(a)) are closely related plasma proteins that are associated with hereditary thrombophilia. Low plasminogen levels are found in some patients who developed venous thrombosis, while a population with high plasma concentrations of apo(a) have a higher incidence of arterial thrombosis. Two different gene coding for human apo(a) have been isolated and characterized in order to study and compare these genes with four other closely related genes in the plasminogen-apo(a) gene family. These include the gene coding for plasminogen, two unique plasminogen-related genes, and a gene coding for hepatocyte growth factor. Nucleotide sequence analysis of these genes revealed that the exons and their boundaries of these genes for plasminogen and apo(a), and the plasminogen-related genes, differ only 1-5% in sequence. The types of exon/intron junctions and positions of introns in the molecules are also exactly identical, suggesting that these genes have evolved from an ancestral plasminogen gene via duplication and exon shuffling. By utilizing these results, gene-specific probes have been designed for the analysis of each of the genes in this gene family. The plasminogen and two apo(a) genes were all localized to chromosome 6 by employing the gene-specific primers and genomic DNAs from human-hamster cell hybrids. These data also make it possible to characterize the apo(a) and plasminogen genes in individuals by in vitro amplification.

  3. In vitro oxidative footprinting provides insight into apolipoprotein B-100 structure in low density lipoprotein

    PubMed Central

    Chakraborty, Sourav; Cai, Yang; Tarr, Matthew A.

    2015-01-01

    Low density lipoprotein (LDL) is a major cholesterol carrier in human blood. Oxidations of apolipoprotein B-100 (apo B-100, LDL protein) could be pro-atherogenic and play critical roles in early stages of plaque formation in the arterial wall. The structure of apo B-100 is still poorly understood, partially due to its size (550 KDa, 4563 amino acids). To gain an insight into LDL structure, we mapped the regions of apo B-100 in human LDL which were prone to oxidation using peroxynitrite and hypochlorite as probes. In this study, LDL was incubated with various concentrations of peroxynitrite and sodium hypochlorite in bicarbonate buffer. The LDL protein apo B-100 was delipidated, denatured, alkylated and subjected to tryptic digestion. Tryptic peptides were analyzed employing liquid chromatography – tandem mass spectrometry (LC-MS/MS). Database search was performed against the apo B-100 database (P04114) using “SEQUEST” algorithm to identify peroxynitrite and hypochlorite mediated oxidations markers nitrotyrosine, nitrotryptophan, hydroxy-tryptophan and 3-chlorotyrosine. Several site specific oxidations were identified in apo B-100 after treatment of intact LDL particles with the oxidants. We hypothesize that these regions could be accessible to oxidant and critical for early events in atherosclerotic plaque deposition. PMID:25176030

  4. Mammalian embryonic cerebrospinal fluid proteome has greater apolipoprotein and enzyme pattern complexity than the avian proteome.

    PubMed

    Parada, Carolina; Gato, Angel; Bueno, David

    2005-01-01

    During early stages of embryo development, the brain cavity is filled with Embryonic Cerebro-Spinal Fluid, which has an essential role in the survival, proliferation and neurogenesis of the neuroectodermal stem cells. We identified and analyzed the proteome of Embryonic Cerebro-Spinal Fluid from rat embryos (Rattus norvegicus), which includes proteins involved in the regulation of Central Nervous System development. The comparison between mammalian and avian Embryonic Cerebro-Spinal Fluid proteomes reveals great similarity, but also greater complexity in some protein groups. The pattern of apolipoproteins and enzymes in CSF is more complex in the mammals than in birds. This difference may underlie the greater neural complexity and synaptic plasticity found in mammals. Fourteen Embryonic Cerebro-Spinal Fluid gene products were previously identified in adult human Cerebro-Spinal Fluid proteome, and interestingly they are altered in patients with neurodegenerative diseases and/or neurological disorders. Understanding these molecules and the mechanisms they control during embryonic neurogenesis may contribute to our understanding of Central Nervous System development and evolution, and these human diseases. PMID:16335996

  5. Adolescent idiopathic scoliosis (AIS): a multifactorial cascade concept for pathogenesis and embryonic origin.

    PubMed

    Burwell, R Geoffrey; Clark, Emma M; Dangerfield, Peter H; Moulton, Alan

    2016-01-01

    This paper formulates a novel multifactorial Cascade Concept for the pathogenesis of adolescent idiopathic scoliosis (AIS). This Concept stems from the longitudinal findings of Clark et al. (J Bone Miner Res 29(8):1729-36, 2014) who identified leptin body composition factors at 10 years of age associated with a scoliosis deformity found at 15 years. We interpret these findings in the light of some concepts for AIS pathogenesis. In particular, we speculate that the leptin body composition effect is linked to central nervous system development and the initiation of the asynchronous neuro-osseous growth mechanism that involves the creation of a neuraxis tether of relative anterior vertebral overgrowth. The latter mechanism in combination with age and gender-related anatomical variants of vertebral backward tilt (dorsal shear concept), human upright posture, adolescent growth factors, Hueter-Volkmann effect in vertebrae and vertebral bone mass abnormalities, lead to AIS, possibly both initiation and progression of scoliosis curvatures. Being multifactorial, while the Cascade Concept cannot be tested for all its components, some components should be testable by the method of numerical simulation. Clark et al. (J Bone Miner Res 29(8):1729-36, 2014) also suggested the origin of scoliosis was in the embryonic stages of life from cell types, including adipocytes and osteoblasts, derived from the same progenitor cells, and myoblasts from mesodermal somites. The involvement of cell types from different developmental origins suggests a process acting in embryonic life at a similar time, probably environmental, as previously proposed from anthropometric studies. As a Complex disease, AIS will involve genetic, environmental and life style factors operating in development and growth; this possibility needs evaluating in epidemiological studies. PMID:27252984

  6. Function and Comorbidities of Apolipoprotein E in Alzheimer's Disease

    PubMed Central

    Leduc, Valérie; Domenger, Dorothée; De Beaumont, Louis; Lalonde, Daphnée; Bélanger-Jasmin, Stéphanie; Poirier, Judes

    2011-01-01

    Alzheimer's disease (AD)—the most common type of dementia among the elderly—represents one of the most challenging and urgent medical mysteries affecting our aging population. Although dominant inherited mutation in genes involved in the amyloid metabolism can elicit familial AD, the overwhelming majority of AD cases, dubbed sporadic AD, do not display this Mendelian inheritance pattern. Apolipoprotein E (APOE), the main lipid carrier protein in the central nervous system, is the only gene that has been robustly and consistently associated with AD risk. The purpose of the current paper is thus to highlight the pleiotropic roles and the structure-function relationship of APOE to stimulate both the functional characterization and the identification of novel lipid homeostasis-related molecular targets involved in AD. PMID:21559182

  7. Apolipoprotein E alleles in women with severe pre-eclampsia.

    PubMed Central

    Nagy, B; Rigó, J; Fintor, L; Karádi, I; Tóth, T

    1998-01-01

    This study investigated the frequency of apolipoprotein E (apoE) alleles among women with severe pre-eclampsia. The presence of the three most common apoE alleles (epsilon 2, epsilon 3, epsilon 4) was determined by polymerase chain reaction-restriction fragment length polymorphism in three groups of white women: non-pregnant healthy (n = 101), pregnant healthy (n = 52), and pregnant with a diagnosis of severe pre-eclampsia (n = 54). The frequency of apo epsilon 2 was highest among women with severe pre-eclampsia (16.6%) followed by non-pregnant women (12.9%), and those experiencing a healthy pregnancy (10.6%). The higher frequency of the apo epsilon 2 allele detected among women with severe pre-eclampsia suggests that apoE may play a role in the development of pre-eclampsia. PMID:9659248

  8. Effect of Leptin Administration on Circulating Apolipoprotein CIII levels in Patients With Lipodystrophy.

    PubMed

    Kassai, Andrea; Muniyappa, Ranganath; Levenson, Amy E; Walter, Mary F; Abel, Brent S; Ring, Michael; Taylor, Simeon I; Biddinger, Sudha B; Skarulis, Monica C; Gorden, Phillip; Brown, Rebecca J

    2016-04-01

    Patients with lipodystrophy had elevated apolipoprotein CIII (apoCIII) compared to healthy controls. ApoCIII did not change with leptin treatment despite significant reductions in serum triglyceride. PMID:26900642

  9. Hepatosteatosis and estrogen increase apolipoprotein O production in the chicken.

    PubMed

    Schmidinger, Barbara; Weijler, Anna M; Schneider, Wolfgang J; Hermann, Marcela

    2016-08-01

    Apolipoprotein O (ApoO) is a recently discovered plasma apolipoprotein that may also play a role in the mitochondrial inner membrane. Possibly due to this complexity, its physiological functions have not been elucidated yet. To gain insight from a non-mammalian experimental system, we have investigated the regulation of ApoO levels in an alternative, well-suited model for studies on lipid metabolism, the chicken. qPCR using specific primer pairs and Western blot analysis with our rabbit anti-chicken ApoO antiserum demonstrated ApoO in the liver of chickens fed a control or a fat-enriched diet, as well as in 2 chicken hepatoma cell lines, LMH cells and the estrogen-responsive LMH-2A cells, under conditions of lipid loading by incubation with BSA-complexed oleic acid. Induced triglyceride accumulation in both the liver and the hepatic cells was associated with significantly increased levels of ApoO mRNA and protein. Furthermore, upon treatment for 24 h with estrogen of the estrogen receptor-expressing LMH-2A cells, quantitative analysis of ApoO transcripts and Western blotting revealed increases of ApoO expression. Finally, upon a single administration of estrogen to roosters that leads to hyperlipidemia, higher hepatic levels of both ApoO transcript and protein were observed within 24 h. Based on these data, we propose that hepatic expression of ApoO is tightly linked not only to diet-induced hepatosteatosis, but also to increased lipoprotein-production induced by, e.g., hormones. The findings support a role of ApoO as an effector of compromised mitochondrial function that likely accompanies the onset of non-alcoholic fatty liver disease. PMID:27126072

  10. Nosocomial Infections after Severe Trauma Are Associated With Lower Apolipoproteins B and AII

    PubMed Central

    Femling, Jon K.; West, Sonlee D.; Hauswald, Erik K.; Gresham, Hattie D.; Hall, Pamela R.

    2014-01-01

    BACKGROUND Infection following severe trauma is a significant cause of morbidity and mortality days to weeks after the initial injury. Apolipoproteins play important roles in host defense and circulating concentrations are altered by the acute inflammatory response. The purpose of this study was to determine if patients who acquire infection following severe trauma have significantly lower apolipoprotein levels than trauma patients who do not become infected. METHODS We conducted a case-control study on a prospectively identified cohort of adult patients admitted to our intensive care unit after severe trauma (Injury Severity Score ≥ 16). We compared plasma apolipoprotein levels between patients who acquired an infection within 30 days after trauma (cases) and those that remained infection free (controls). RESULTS Of 40 patients experiencing severe trauma, we identified 22 cases that developed an infection within 30 days after injury. Cases had significantly lower post-trauma plasma levels of apolipoprotein-B (p=0.02) and apolipoprotein-AII (p=0.02) compared to controls. Consistent with previous studies, cases also received greater volumes of crystalloid infusions (p<0.01) and blood transfusions (p<0.01). Cases also had a more profound inflammatory response as measured by Interleukin-6 levels (p=0.02). CONCLUSIONS Infection after severe trauma is associated with decreased circulating apolipoproteins as compared to uninfected controls. Profoundly decreased plasma apolipoproteins B and AII could potentially contribute to the impaired immunity after severe trauma. Apolipoproteins are potential targets for identifying those patients at risk of infection after trauma and for interventions aimed at preventing nosocomial infections. PMID:23511146

  11. Influence of Peripheral Artery Disease and Statin Therapy on Apolipoprotein Profiles

    PubMed Central

    Gardner, Andrew W.; Parker, Donald E.; Montgomery, Polly S.; Esponda, Omar L.; Casanegra, Ana I.

    2013-01-01

    Apolipoprotein B is a stronger predictor of myocardial infarction than LDL cholesterol, and it is inversely related to physical activity and modifiable with exercise training. As such, apolipoprotein measures may be of particular relevance for subjects with PAD and claudication. We compared plasma apolipoprotein profiles in 29 subjects with peripheral artery disease (PAD) and intermittent claudication and in 39 control subjects. Furthermore, we compared the plasma apolipoprotein profiles of subjects with PAD either treated (n = 17) or untreated (n = 12) with statin medications. For the apolipoprotein subparticle analyses, subjects with PAD had higher age-adjusted Lp-B:C (P < 0.05) and lower values of Lp-A-I:A-II (P < 0.05) than controls. The PAD group taking statins had lower age-adjusted values for apoB (P < 0.05), Lp-A-II:B:C:D:E (P < 0.05), Lp-B:E + Lp-B:C:E (P < 0.05), Lp-B:C (P < 0.05), and Lp-A-I (P < 0.05) than the untreated PAD group. Subjects with PAD have impaired apolipoprotein profiles than controls, characterized by Lp-B:C and Lp-A-I:A-II. Furthermore, subjects with PAD on statin medications have a more favorable risk profile, particularly noted in multiple apolipoprotein subparticles. The efficacy of statin therapy to improve cardiovascular risk appears more evident in the apolipoprotein sub-particle profile than in the more traditional lipid profile of subjects with PAD and claudication. This trial is registered with ClinicalTrials.gov NCT00618670. PMID:24102029

  12. Influence of peripheral artery disease and statin therapy on apolipoprotein profiles.

    PubMed

    Gardner, Andrew W; Alaupovic, Petar; Parker, Donald E; Montgomery, Polly S; Esponda, Omar L; Casanegra, Ana I

    2013-01-01

    Apolipoprotein B is a stronger predictor of myocardial infarction than LDL cholesterol, and it is inversely related to physical activity and modifiable with exercise training. As such, apolipoprotein measures may be of particular relevance for subjects with PAD and claudication. We compared plasma apolipoprotein profiles in 29 subjects with peripheral artery disease (PAD) and intermittent claudication and in 39 control subjects. Furthermore, we compared the plasma apolipoprotein profiles of subjects with PAD either treated (n = 17) or untreated (n = 12) with statin medications. For the apolipoprotein subparticle analyses, subjects with PAD had higher age-adjusted Lp-B:C (P < 0.05) and lower values of Lp-A-I:A-II (P < 0.05) than controls. The PAD group taking statins had lower age-adjusted values for apoB (P < 0.05), Lp-A-II:B:C:D:E (P < 0.05), Lp-B:E + Lp-B:C:E (P < 0.05), Lp-B:C (P < 0.05), and Lp-A-I (P < 0.05) than the untreated PAD group. Subjects with PAD have impaired apolipoprotein profiles than controls, characterized by Lp-B:C and Lp-A-I:A-II. Furthermore, subjects with PAD on statin medications have a more favorable risk profile, particularly noted in multiple apolipoprotein subparticles. The efficacy of statin therapy to improve cardiovascular risk appears more evident in the apolipoprotein sub-particle profile than in the more traditional lipid profile of subjects with PAD and claudication. This trial is registered with ClinicalTrials.gov NCT00618670. PMID:24102029

  13. Smooth Muscle Cell Foam Cell Formation, Apolipoproteins, and ABCA1 in Intracranial Aneurysms: Implications for Lipid Accumulation as a Promoter of Aneurysm Wall Rupture.

    PubMed

    Ollikainen, Eliisa; Tulamo, Riikka; Lehti, Satu; Lee-Rueckert, Miriam; Hernesniemi, Juha; Niemelä, Mika; Ylä-Herttuala, Seppo; Kovanen, Petri T; Frösen, Juhana

    2016-07-01

    Saccular intracranial aneurysm (sIA) aneurysm causes intracranial hemorrhages that are associated with high mortality. Lipid accumulation and chronic inflammation occur in the sIA wall. A major mechanism for lipid clearance from arteries is adenosine triphosphate-binding cassette A1 (ABCA1)-mediated lipid efflux from foam cells to apolipoprotein A-I (apoA-I). We investigated the association of wall degeneration, inflammation, and lipid-related parameters in tissue samples of 16 unruptured and 20 ruptured sIAs using histology and immunohistochemistry. Intracellular lipid accumulation was associated with wall remodeling (p = 0.005) and rupture (p = 0.020). Foam cell formation was observed in smooth muscle cells, in addition to CD68- and CD163-positive macrophages. Macrophage infiltration correlated with intracellular lipid accumulation and apolipoproteins, including apoA-I. ApoA-I correlated with markers of lipid accumulation and wall degeneration (p = 0.01). ApoA-I-positive staining colocalized with ABCA1-positive cells particularly in sIAs with high number of smooth muscle cells (p = 0.003); absence of such colocalization was associated with wall degeneration (p = 0.017). Known clinical risk factors for sIA rupture correlated inversely with apoA-I. We conclude that lipid accumulation associates with sIA wall degeneration and risk of rupture, possibly via formation of foam cells and subsequent loss of mural cells. Reduced removal of lipids from the sIA wall via ABCA1-apoA-I pathway may contribute to this process. PMID:27283327

  14. Effects of blackberry (Morus nigra L.) consumption on serum concentration of lipoproteins, apo A-I, apo B, and high-sensitivity-C-reactive protein and blood pressure in dyslipidemic patients

    PubMed Central

    Aghababaee, Sahar Keshtkar; Vafa, Mohammadreza; Shidfar, Farzad; Tahavorgar, Atefeh; Gohari, Mahmoodreza; Katebi, Davod; Mohammadi, Vida

    2015-01-01

    Background: This study investigated blackberry (Persian mulberry) effects on apo A-I, apo B, high-sensitivity-C-reactive protein (hs-CRP), and systolic blood pressure (SBP) and diastolic blood pressure (DBP) in dyslipidemic patients. Materials and Methods: In this 8-week randomized clinical trial, 72 dyslipidemic patients were randomly divided into two groups: Intervention (300 mL/day blackberry juice with pulp) and control group (usual diets). Before and after the intervention, fasting blood samples were taken from both groups and serum concentration of lipoprotein, apo A-I and apo B, serum lipids (total cholesterol, low-density lipoprotein, high-density lipoprotein [HDL], and triglyceride), hs-CRP were measured. Blood pressure before and after the study was measured with a mercury manometer. Results: At week 8 in the intervention group, apo A-I and HDL increased significantly (P = 0.015, P = 0.001, respectively), apo B and hs-CRP decreased significantly (P = 0.044, P = 0.04, respectively). Mean changes in apo A-I and HDL and apo B/apo A-I ratio were significant between the groups (P = 0.005, P = 0.014, and P = 0.009, respectively). After 8 weeks, there was a significant difference between hs-CRP mean values (P = 0.01) of the groups. At week 8, SBP decreased significantly (P = 0.005) in the intervention group with no significant differences for SBP mean values between the groups. No significant changes were observed in other lipid parameters and DBP in the intervention group and between the groups. Conclusion: Blackberry consumption may exert beneficial effects on apolipoproteins, blood pressure, and inflammatory markers in individuals with lipid disorders. PMID:26622259

  15. Association of apolipoprotein A1 and B with kidney function and chronic kidney disease in two multiethnic population samples

    PubMed Central

    Goek, Oemer-Necmi; Köttgen, Anna; Hoogeveen, Ron C.; Ballantyne, Christie M.; Coresh, Josef; Astor, Brad C.

    2012-01-01

    Background Circulating lipoproteins and their protein constituents, apolipoproteins, are risk factors for chronic kidney disease (CKD). The associations between apolipoprotein A1, apolipoprotein B and their ratio with glomerular filtration rate estimated from the new CKD Epidemiology Collaboration (CKD-EPI) equation (eGFR) are not well studied in the general population. Methods Associations between apolipoprotein A1, B and their ratio with the outcomes of eGFR, CKD (eGFR <60 mL/min/1.73m2) and albuminuria were examined in the Atherosclerosis Risk in Communities study (ARIC, n = 10 292, 1996–98) and the Third National Health and Nutrition Examination Survey (NHANES III, n = 7023, 1988–91). Cross-sectional multivariable-adjusted analyses were performed using linear and logistic regression. Prospective analyses related baseline apolipoprotein levels to subsequent CKD incidence over 10 years using the ARIC Carotid MRI follow-up cohort (n = 1659). Results Higher apolipoprotein A1 quartiles were associated with a lower prevalence of CKD [Q4 versus Q1: odds ratio (OR) 0.73, P-trend = 0.02 in ARIC; Q4 versus Q1: OR 0.53, P-trend <0.01 in NHANES III] as well as with higher eGFR (P-trend <0.01 in ARIC and NHANES III). No consistent significant associations were found for apolipoprotein B in either study. The apolipoprotein B/A1 ratio was significantly associated with eGFR across quartiles in both studies (P-trend <0.01) and with CKD in ARIC (Q4 versus Q1: OR 1.23, P-trend = 0.01). Prospectively, there were trends for the association of apolipoproteins with incident CKD [Q4 versus Q1: incidence rate ratio (IRR) = 0.68 for apolipoprotein A1, P-trend = 0.1; Q4 versus Q1: IRR = 1.35 for apolipoprotein B, P-trend = 0.2]. Associations were not systematically stronger when comparing traditional lipids (total cholesterol, low-density lipoprotein or high-density lipoprotein) to apolipoproteins. Conclusions Higher serum apolipoprotein A1 was associated with lower prevalence of CKD

  16. Maritime traffic monitoring using a space-based AIS receiver

    NASA Astrophysics Data System (ADS)

    Eriksen, Torkild; Høye, Gudrun; Narheim, Bjørn; Meland, Bente Jensløkken

    2006-05-01

    The Automatic Identification System (AIS) is a maritime safety and vessel traffic system imposed by the International Maritime Organization (IMO). The system broadcasts position reports and short messages with information about the ship and the voyage. Using frequencies in the maritime VHF band, the coverage is similar to other VHF applications, and is essentially dependent on the altitude of the antenna. For ship-to-ship communications the range is typically 20 nautical miles and for ship-to-shore up to 40 nm. A space-based AIS receiver in low earth orbit will have a range to the horizon of more than 1000 nm, giving an excellent opportunity for large-area ocean surveillance. The Norwegian Defence Research Establishment (FFI) has performed a feasibility study on reception of AIS messages from space. The results show that a ship detection probability of near 100% can be obtained for up to 1000 ships within the coverage area, and that for a standard AIS receiver a signal power margin of 10-20 dB can be achieved. On this background, swath-width analyses for European scenarios are done. It is argued that space-based reception of AIS messages is a promising way of achieving long-range identification and tracking services at marginal cost.

  17. Discovering Knowledge from AIS Database for Application in VTS

    NASA Astrophysics Data System (ADS)

    Tsou, Ming-Cheng

    The widespread use of the Automatic Identification System (AIS) has had a significant impact on maritime technology. AIS enables the Vessel Traffic Service (VTS) not only to offer commonly known functions such as identification, tracking and monitoring of vessels, but also to provide rich real-time information that is useful for marine traffic investigation, statistical analysis and theoretical research. However, due to the rapid accumulation of AIS observation data, the VTS platform is often unable quickly and effectively to absorb and analyze it. Traditional observation and analysis methods are becoming less suitable for the modern AIS generation of VTS. In view of this, we applied the same data mining technique used for business intelligence discovery (in Customer Relation Management (CRM) business marketing) to the analysis of AIS observation data. This recasts the marine traffic problem as a business-marketing problem and integrates technologies such as Geographic Information Systems (GIS), database management systems, data warehousing and data mining to facilitate the discovery of hidden and valuable information in a huge amount of observation data. Consequently, this provides the marine traffic managers with a useful strategic planning resource.

  18. 17-β-estradiol up-regulates apolipoprotein genes expression during osteoblast differentiation in vitro.

    PubMed

    Gui, Yuyan; Chu, Nan; Qiu, Xuemin; Tang, Wei; Gober, Hans-Jürgen; Li, Dajin; Wang, Ling

    2016-05-23

    Apolipoproteins are of great physiological importance and are associated with different diseases. Many independent studies of patterns of gene expression during osteoblast differentiation have been described, and some apolipoproteins have been induced during this process. 17-β-estradiol (E2) may enhance osteoblast physiological function. However, no studies have indicated whether E2 can modulate the expression of apolipoproteins during osteoblast differentiation in vitro. The aim of the current study was to observe the regulation of apolipoprotein mRNA expression by E2 during this process. Primary osteoblasts were collected from the calvaria of newborn mice and were subjected to osteoblast differentiation in vitro with serial concentrations of E2. RNA was isolated on days 0, 5, and 25 of differentiation. Real-time PCR was performed to analyze the levels of apolipoprotein mRNA. Results showed that during osteoblast differentiation all of the apolipoprotein genes were up-regulated by E2 in a dose-dependent manner. Moreover, only ApoE was strongly induced during the mineralization of cultured osteoblasts. This result suggests that ApoE might be involved in osteoblast differentiation. The hypothesis is that E2 promotes osteoblast differentiation by up-regulating ApoE gene expression, though further study is needed to confirm this hypothesis. PMID:27074899

  19. Automated AI-based designer of electrical distribution systems

    NASA Astrophysics Data System (ADS)

    Sumic, Zarko

    1992-03-01

    Designing the electrical supply system for new residential developments (plat design) is an everyday task for electric utility engineers. Presently this task is carried out manually resulting in an overdesigned, costly, and nonstandardized solution. As an ill-structured and open-ended problem, plat design is difficult to automate with conventional approaches such as operational research or CAD. Additional complexity in automating plat design is imposed by the need to process spatial data such as circuits' maps, records, and construction plans. The intelligent decision support system for automated electrical plate design (IDSS for AEPD) is an engineering tool aimed at automating plate design. IDSS for AEPD combines the functionality of geographic information systems (GIS) a geographically referenced database, with the sophistication of artificial intelligence (AI) to deal with the complexity inherent in design problems. Blackboard problem solving architecture, concentrated around INGRES relational database and NEXPERT object expert system shell have been chosen to accommodate the diverse knowledge sources and data models. The GIS's principal task it to create, structure, and formalize the real world representation required by the rule based reasoning portion of the AEPD. IDSS's capability to support and enhance the engineer's design, rather than only automate the design process through a prescribed computation, makes it a preferred choice among the possible techniques for AEPD. This paper presents the results of knowledge acquisition and the knowledge engineering process with AEPD tool conceptual design issues. To verify the proposed concept, the comparison of results obtained by the AEPD tool with the design obtained by an experienced human designer is given.

  20. Toward detecting California shrubland canopy chemistry with AIS data

    NASA Technical Reports Server (NTRS)

    Price, Curtis V.; Westman, Walter E.

    1987-01-01

    Airborne Imaging Spectrometer (AIS)-2 data of coastal sage scrub vegetation were examined for fine spectral features that might be used to predict concentrations of certain canopy chemical constituents. A Fourier notch filter was applied to the AIS data and the TREE and ROCK mode spectra were ratioed to a flat field. Portions of the resulting spectra resemble spectra for plant cellulose and starch in that both show reduced reflectance at 2100 and 2270 nm. The latter are regions of absorption of energy by organic bonds found in starch and cellulose. Whether the relationship is sufficient to predict the concentration of these chemicals from AIS spectra will require testing of the predictive ability of these wavebands with large field sample sizes.

  1. Artificial intelligence (AI) based tactical guidance for fighter aircraft

    NASA Technical Reports Server (NTRS)

    Mcmanus, John W.; Goodrich, Kenneth H.

    1990-01-01

    A research program investigating the use of artificial intelligence (AI) techniques to aid in the development of a Tactical Decision Generator (TDG) for Within Visual Range air combat engagements is discussed. The application of AI programming and problem solving methods in the development and implementation of the Computerized Logic For Air-to-Air Warfare Simulations (CLAWS), a second generation TDG, is presented. The knowledge-based systems used by CLAWS to aid in the tactical decision-making process are outlined in detail, and the results of tests to evaluate the performance of CLAWS versus a baseline TDG developed in FORTRAN to run in real time in the Langley Differential Maneuvering Simulator, are presented. To date, these test results have shown significant performance gains with respect to the TDG baseline in one-versus-one air combat engagements, and the AI-based TDG software has proven to be much easier to modify and maintain than the baseline FORTRAN TDG programs.

  2. In Vivo and In Vitro Effects of an Apolipoprotein E Mimetic Peptide on Amyloid-β Pathology

    PubMed Central

    Handattu, Shaila P.; Monroe, Candyce E.; Nayyar, Gaurav; Palgunachari, Mayakonda N.; Kadish, Inga; van Groen, Thomas; Anantharamaiah, G.M.; Garber, David W.

    2014-01-01

    Background Apolipoprotein E (ApoE) is the major apolipoprotein present in the high-density lipoprotein-like particles in the central nervous system (CNS). ApoE is involved in various protective functions in CNS including cholesterol transport, anti-inflammatory, and antioxidant effects. An ApoE peptide would be expected to exert protective effects on neuroinflammation. Objective To determine the effects of an ApoE mimetic peptide Ac-hE18A-NH2 on amyloid-β pathology. Method Using human APP/PS1ΔE9 transgenic mice and in vitro studies, we have evaluated the effect of an ApoE mimetic peptide, Ac-hE18A-NH2, on amyloid plaque deposition and inflammation. Results Administration of Ac-hE18A-NH2 to APP/PS1ΔE9 mice for 6 weeks (50 μg/mouse, 3 times a week) significantly improved cognition with a concomitant decrease in amyloid plaque deposition and reduced activated microglia and astrocytes, and increased brain ApoE levels. Oligomeric Aβ42 (oAβ42) and oxidized PAPC (ox-PAPC) inhibited secretion of ApoE in U251 cells, a human astrocyte cell line, and this effect was ameliorated in the presence of peptide Ac-hE18A-NH2. The peptide also increased Aβ42 uptake in a cell line of human macrophages. Conclusions Peptide Ac-hE18A-NH2 attenuates the effects of oxidative stress on ApoE secretion, inhibits amyloid plaque deposition, and thus could be beneficial in the treatment of Alzheimer’s disease. PMID:23603398

  3. A Complete Backbone Assignment of the Apolipoprotein E LDL Receptor Binding Domain [Letter to the Editor

    SciTech Connect

    Xu, Chao; Sivashanmugam, Arun; Hoyt, David W.; Wang, Jianjun

    2005-06-01

    Human apolipoprotein E (apoE) is a 299-residue exchangeable apolipoprotein that was initially recognized as a major determinant in lipoprotein metabolism and cardiovascular diseases. Recent evidence has indicated that apoE also plays critical roles in several other important biological processes not directly related to its lipid transport function, including Alzheimer's disease, cognitive function, immunoregulation, cell signaling, and possibly even infectious diseases. ApoE contains two structural/functional domains: A N-terminal domain spanning residues 1-191 that is responsible for apoE's LDL receptor binding activity and a C-terminal domain (residues 216-199) that is responsible for lipoprotein-binding (1). The x-ray crystal structure of the lipid-free apoE N-terminal domain was solved by Wilson et al in 1991 which represented the only high-resolution structure of this protein. This structure showed an unusually elongated four-helix bundle (2) that was organized in such 2 a way that its hydrophobic faces were directed towards the protein interior, whereas the hydrophilic faces were oriented towards the solvent. The major receptor-binding region, residues 130-150, was located on the fourth helix. The amphipathic a-helices were connected by short loops, giving rise to a compact, globular structure. However, this structure only contained residues 23-165. Recent studies have shown that residues beyond residues 23-165 are also very important to the apoE LDL receptor binding activity. For example, a mutation at position R172 reduces the receptor binding activity of apoE to only {approx}2% (3). In addition, an E3K mutant significantly increased the apoE receptor binding activity as well (4). While the x-ray crystal structure of the apoE N-terminal domain provided detailed structural information for most region of this domain, this structure does not provide an explanation of the above experimental results regarding the structural contribution to apoE's LDL receptor

  4. Influence of depleted uranium on hepatic cholesterol metabolism in apolipoprotein E-deficient mice.

    PubMed

    Souidi, M; Racine, R; Grandcolas, L; Grison, S; Stefani, J; Gourmelon, P; Lestaevel, P

    2012-04-01

    Depleted uranium (DU) is uranium with a lower content of the fissile isotope U-235 than natural uranium. It is a radioelement and a waste product from the enrichment process of natural uranium. Because of