WorldWideScience

Sample records for apolipoprotein domain derived

  1. Influence of domain stability on the properties of human apolipoprotein E3 and E4 and mouse apolipoprotein E.

    Science.gov (United States)

    Nguyen, David; Dhanasekaran, Padmaja; Nickel, Margaret; Mizuguchi, Chiharu; Watanabe, Mayu; Saito, Hiroyuki; Phillips, Michael C; Lund-Katz, Sissel

    2014-06-24

    The human apolipoprotein (apo) E4 isoform, which differs from wild-type apoE3 by the single amino acid substitution C112R, is associated with elevated risk of cardiovascular and Alzheimer’s diseases, but the molecular basis for this variation between isoforms is not understood. Human apoE is a two-domain protein comprising an N-terminal helix bundle and a separately folded C-terminal region. Here, we examine the concept that the ability of the protein to bind to lipid surfaces is influenced by the stability (or readiness to unfold) of these domains. The lipid-free structures and abilities to bind to lipid and lipoprotein particles of a series of human and mouse apoE variants with varying domain stabilities and domain–domain interactions are compared. As assessed by urea denaturation, the two domains are more unstable in apoE4 than in apoE3. To distinguish the contributions of the destabilization of each domain to the greater lipid-binding ability of apoE4, the properties of the apoE4 R61T and E255A variants, which have the same helix bundle stabilities but altered C-terminal domain stabilities, are compared. In these cases, the effects on lipid-binding properties are relatively minor, indicating that the destabilization of the helix bundle domain is primarily responsible for the enhanced lipid-binding ability of apoE4. Unlike human apoE, mouse apoE behaves essentially as a single domain, and its lipid-binding characteristics are more similar to those of apoE4. Together, the results show that the overall stability of the entire apoE molecule exerts a major influence on its lipid- and lipoprotein-binding properties.

  2. Cognitive deficits and disruption of neurogenesis in a mouse model of apolipoprotein E4 domain interaction.

    Science.gov (United States)

    Adeosun, Samuel O; Hou, Xu; Zheng, Baoying; Stockmeier, Craig; Ou, Xiaoming; Paul, Ian; Mosley, Thomas; Weisgraber, Karl; Wang, Jun Ming

    2014-01-31

    Apolipoprotein E4 (apoE4) allele is the major genetic risk factor for sporadic Alzheimer disease (AD) due to the higher prevalence and earlier onset of AD in apoE4 carriers. Accumulating data suggest that the interaction between the N- and the C-terminal domains in the protein may be the main pathologic feature of apoE4. To test this hypothesis, we used Arg-61 mice, a model of apoE4 domain interaction, by introducing the domain interaction feature of human apoE4 into native mouse apoE. We carried out hippocampus-dependent learning and memory tests and related cellular and molecular assays on 12- and 3-month-old Arg-61 and age-matched background C57BL/6J mice. Learning and memory task performance were impaired in Arg-61 mice at both old and young ages compared with C57BL/6J mice. Surprisingly, young Arg-61 mice had more mitotic doublecortin-positive cells in the subgranular zone; mRNA levels of brain-derived neurotrophic factor (BDNF) and TrkB were also higher in 3-month-old Arg-61 hippocampus compared with C57BL/6J mice. These early-age neurotrophic and neurogenic (proliferative) effects in the Arg-61 mouse may be an inadequate compensatory but eventually detrimental attempt by the system to "repair" itself. This is supported by the higher cleaved caspase-3 levels in the young animals that not only persisted, but increased in old age, and the lower levels of doublecortin at old age in the hippocampus of Arg-61 mice. These results are consistent with human apoE4-dependent cognitive and neuro-pathologic changes, supporting the principal role of domain interaction in the pathologic effect of apoE4. Domain interaction is, therefore, a viable therapeutic/prophylactic target for cognitive impairment and AD in apoE4 subjects.

  3. Resonance assignments and secondary structure of apolipoprotein E C-terminal domain in DHPC micelles.

    Science.gov (United States)

    Lo, Chi-Jen; Chyan, Chia-Lin; Chen, Yi-Chen; Chang, Chi-Fon; Huang, Hsien-Bin; Lin, Ta-Hsien

    2015-04-01

    Human apolipoprotein E (apoE) has been known to play a key role in the transport of plasma cholesterol and lipoprotein metabolism. It is an apolipoprotein of 299 amino acids with a molecular mass, ~34 kDa. ApoE has three major isoforms, apoE2, apoE3, and apoE4 which differ only at residue 112 or 158. ApoE consists of two independently folded domains (N-terminal and C-terminal domain) separated by a hinge region. The N-terminal domain and C-terminal domain of apoE are responsible for the binding to receptor and to lipid, respectively. Since the high resolution structures of apoE in lipids are still unavailable to date, we therefore aim to resolve the structures in lipids by NMR. Here, we reported the resonance assignments and secondary structure distribution of the C-terminal domain of wild-type human apoE (residue 195-299) in the micelles formed by dihexanoylphosphatidylcholine. Our results may provide a novel structural model of apoE in micelles and may shed new light on the molecular mechanisms underlying the apoE related biological processes.

  4. The N-terminal domain of apolipoprotein B-100: structural characterization by homology modeling

    Directory of Open Access Journals (Sweden)

    Khachfe Hassan M

    2007-07-01

    Full Text Available Abstract Background Apolipoprotein B-100 (apo B-100 stands as one of the largest proteins in humans. Its large size of 4536 amino acids hampers the production of X-ray diffraction quality crystals and hinders in-solution NMR analysis, and thus necessitates a domain-based approach for the structural characterization of the multi-domain full-length apo B. Results The structure of apo B-17 (the N-terminal 17% of apolipoprotein B-100 was predicted by homology modeling based on the structure of the N-terminal domain of lipovitellin (LV, a protein that shares not only sequence similarity with B17, but also a functional aspect of lipid binding and transport. The model structure was first induced to accommodate the six disulfide bonds found in that region, and then optimized using simulated annealing. Conclusion The content of secondary structural elements in this model structure correlates well with the reported data from other biophysical probes. The overall topology of the model conforms with the structural outline corresponding to the apo B-17 domain as seen in the EM representation of the complete LDL structure.

  5. Apolipoprotein E4 domain interaction accelerates diet-induced atherosclerosis in hypomorphic Arg-61 Apoe mice

    Science.gov (United States)

    Eberlé, Delphine; Kim, Roy Y.; Luk, Fu Sang; de Mochel, Nabora Soledad Reyes; Gaudreault, Nathalie; Olivas, Victor R.; Kumar, Nikit; Posada, Jessica M.; Birkeland, Andrew C.; Rapp, Joseph H.; Raffai, Robert L.

    2012-01-01

    Objective Apolipoprotein (apo) E4 is an established risk factor for atherosclerosis, but the structural components underlying this association remain unclear. ApoE4 is characterized by two biophysical properties: domain interaction and molten globule state. Substituting Arg-61 for Thr-61 in mouse apoE introduces domain interaction without molten globule state, allowing us to delineate potential pro-atherogenic effects of domain interaction in vivo. Methods and Results We studied atherosclerosis susceptibility of hypomorphic Apoe mice expressing either Thr-61 or Arg-61 apoE (ApoeTh/h or ApoeRh/h mice). On a chow diet, both mouse models were normo-lipidemic with similar levels of plasma apoE and lipoproteins. However, on a high cholesterol diet, ApoeRh/h mice displayed increased levels of total plasma cholesterol and VLDL as well as larger atherosclerotic plaques in the aortic root, arch and descending aorta compared to ApoeTh/h mice. In addition, evidence of cellular dysfunction was identified in peritoneal ApoeRh/h macrophages which released lower amounts of apoE in culture medium and displayed increased expression of MHC class II molecules. Conclusions These data indicate that domain interaction mediates pro-atherogenic effects of apoE4 in part by modulating lipoprotein metabolism and macrophage biology. Pharmaceutical targeting of domain interaction could lead to new treatments for atherosclerosis in apoE4 individuals. PMID:22441102

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

    Science.gov (United States)

    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.

  7. Anti-atherogenic peptide Ep1.B derived from apolipoprotein E induces tolerogenic plasmacytoid dendritic cells.

    Science.gov (United States)

    Bellemore, S M; Nikoopour, E; Au, B C Y; Krougly, O; Lee-Chan, E; Haeryfar, S M; Singh, B

    2014-09-01

    Tolerogenic dendritic cells (DCs) play a critical role in the induction of regulatory T cells (Tregs ), which in turn suppress effector T cell responses. We have previously shown the induction of DCs from human and mouse monocytic cell lines, mouse splenocytes and human peripheral blood monocytes by a novel apolipoprotein E (ApoE)-derived self-peptide termed Ep1.B. We also showed that this C-terminal region 239-252 peptide of ApoE has strong anti-atherogenic activity and reduces neointimal hyperplasia after vascular surgery in rats and wild-type as well as ApoE-deficient mice. In this study, we explored the phenotype of DC subset induced by Ep1.B from monocytic cell lines and from the bone marrow-derived cells. We found Ep1.B treatment induced cells that showed characteristics of plasmacytoid dendritic cells (pDC). We explored in-vitro and in-vivo effects of Ep1.B-induced DCs on antigen-specific T cell responses. Upon in-vivo injection of these cells with antigen, the subsequent ex-vivo antigen-specific proliferation of lymph node cells and splenocytes from recipient mice was greatly reduced. Our results suggest that Ep1.B-induced pDCs promote the generation of Treg cells, and these cells contribute to the induction of peripheral tolerance in adaptive immunity and potentially contribute its anti-atherogenic activity.

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

    Energy Technology Data Exchange (ETDEWEB)

    Maagdenberg, A.M.J.M. van den; Bruijn, I.H. de; Hofker, M.H.; Frants, R.R. (Leiden Univ. (Netherlands)); Knijff, P. de; Smelt, A.H.M.; Leuven, J.A.G.; van' t Hooft, F.; Assmann, G.; Havekes, L.M. (Univ. Hospital, Leiden (Netherlands)); Weng, Wei; Funke, H. (Westfalische Wilhelms-Universitaet, Muester (Germany))

    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

  9. A novel peptide derived from human apolipoprotein E is an inhibitor of tumor growth and ocular angiogenesis.

    Directory of Open Access Journals (Sweden)

    Partha S Bhattacharjee

    Full Text Available Angiogenesis is a hallmark of tumor development and metastasis and now a validated target for cancer treatment. We previously reported that a novel dimer peptide (apoEdp derived from the receptor binding region of human apolipoprotein E (apoE inhibits virus-induced angiogenesis. However, its role in tumor anti-angiogenesis is unknown. This study demonstrates that apoEdp has anti-angiogenic property in vivo through reduction of tumor growth in a mouse model and ocular angiogenesis in a rabbit eye model. Our in vitro studies show that apoEdp inhibits human umbilical vein endothelial cell proliferation, migration, invasion and capillary tube formation. We document that apoEdp inhibits vascular endothelial growth factor-induced Flk-1 activation as well as downstream signaling pathways that involve c-Src, Akt, eNOS, FAK, and ERK1/2. These in vitro data suggest potential sites of the apoE dipeptide inhibition that could occur in vivo.This is the first evidence that a synthetic dimer peptide mimicking human apoE has anti-angiogenesis functions and could be an anti-tumor drug candidate.

  10. Apolipoprotein M

    DEFF Research Database (Denmark)

    Christoffersen, Christina; Dahlbäck, B; Nielsen, L B

    2006-01-01

    ApoM is a novel apolipoprotein mainly present in high-density lipoprotein (HDL). It belongs to the lipocalin protein superfamily and may bind a small but so far unknown lipophilic ligand. It is secreted without cleavage of its hydrophobic signal peptide, which probably anchors apoM...... in the phospholipid moiety of plasma lipoproteins. Recent studies suggest that apoM may affect HDL metabolism and have anti-atherogenic functions. The subfraction of human HDL that contains apoM therefore protects LDL from oxidation and mediates cholesterol efflux more efficiently then HDL without apoM. In addition...... to hepatocytes, apoM is highly expressed in kidney proximal tubule cells. Recent data suggest that apoM is secreted into the pre-urine from the tubule cells but is normally taken up again in a megalin-dependent fashion. Further studies of mice with genetically modified apoM expression will be essential...

  11. Time-domain and frequency-domain approaches to identification of bridge flutter derivatives

    Institute of Scientific and Technical Information of China (English)

    Zhengqing CHEN

    2009-01-01

    Flutter derivatives are essential for flutter analysis of long-span bridges, and they are generally identified from the vibration testing data of a sectional model suspended in a wind tunnel. Making use of the forced vibration testing data of three sectional models,namely, a thin-plate model, a nearly streamlined model,and a bluff-body model, a comparative study was made to identify the flutter derivatives of each model by using a time-domain method and a frequency-domain method. It was shown that all the flutter derivatives of the thin-plate model identified with the frequency-domain method and time-domain method, respectively, agree very well. Moreover, some of the flutter derivatives of each of the other two models identified with the two methods deviate to some extent. More precisely, the frequency-domain method usually results in smooth curves of the flutter derivatives.The formulation of time-domain method makes the identification results of flutter derivatives relatively sensitive to the signal phase lag between vibration state vector and aerodynamic forces and also prone to be disturbed by noise and nonlinearity.

  12. Apolipoprotein M

    DEFF Research Database (Denmark)

    Christoffersen, Christina; Nielsen, Lars Bo

    2013-01-01

    Purpose of review: The review will address the potential roles of apolipoprotein M (apoM) as a carrier protein and modulator of sphingosine-1-phosphate (S1P) bioactivity. Recent findings: Recombinant apoM can bind small lipids such as retinoic acid, oxidized phospholipids, and S1P. Thus......, the effects of apoM may be pleiotrophic. The S1P binding ability of apoM has biological impact. ApoM-bound S1P can activate S1P1 receptors on endothelial cells and deficiency of apoM abolishes the presence of S1P in HDL. In mice, the lack of apoM causes dysfunctional endothelial barrier function in the lungs....... In humans, sepsis that is characterized by impaired endothelial function is associated with low plasma apoM. Summary: Plasma apoM is mainly bound to HDL. The roles of apoM in atherosclerosis and lipoprotein metabolism have been given much attention. New in the field is the discovery of apoM as a chaperone...

  13. Apolipoprotein M

    Directory of Open Access Journals (Sweden)

    Nilsson-Ehle Peter

    2004-10-01

    Full Text Available Abstract Apolipoprotein M (apoM is a 26-kDa protein that is mainly associated with high-density lipoprotein (HDL in human plasma, with a small proportion present in triglyceride-rich lipoproteins (TGRLP and low-density lipoproteins (LDL. Human apoM gene is located in p21.31 on chromosome 6 (chromosome 17, in mouse. Human apoM cDNA (734 base pairs encodes 188-amino acid residue-long protein. It belongs to lipocalin protein superfamily. Human tissue expression array study indicates that apoM is only expressed in liver and in kidney and small amounts are found in fetal liver and kidney. In situ apoM mRNA hybridization demonstrates that apoM is exclusively expressed in the hepatocytes and in the tubule epithelial cells in kidney. Expression of apoM could be regulated by platelet activating factor (PAF, transforming growth factors (TGF, insulin-like growth factor (IGF and leptin in vivo and/or in vitro. It has been demonstrated that apoM expression is dramatically decreased in apoA-I deficient mouse. Hepatocyte nuclear factor-1α (HNF-1α is an activator of apoM gene promoter. Deficiency of HNF-1α mouse shows lack of apoM expression. Mutations in HNF-1α (MODY3 have reduced serum apoM levels. Expression of apoM is significantly decreased in leptin deficient (ob/ob mouse or leptin receptor deficient (db/db mouse. ApoM concentration in plasma is positively correlated to leptin level in obese subjects. These may suggest that apoM is related to the initiation and progression of MODY3 and/or obesity.

  14. Frequency-domain waveform inversion using the phase derivative

    KAUST Repository

    Choi, Yun Seok

    2013-09-26

    Phase wrapping in the frequency domain or cycle skipping in the time domain is the major cause of the local minima problem in the waveform inversion when the starting model is far from the true model. Since the phase derivative does not suffer from the wrapping effect, its inversion has the potential of providing a robust and reliable inversion result. We propose a new waveform inversion algorithm using the phase derivative in the frequency domain along with the exponential damping term to attenuate reflections. We estimate the phase derivative, or what we refer to as the instantaneous traveltime, by taking the derivative of the Fourier-transformed wavefield with respect to the angular frequency, dividing it by the wavefield itself and taking the imaginary part. The objective function is constructed using the phase derivative and the gradient of the objective function is computed using the back-propagation algorithm. Numerical examples show that our inversion algorithm with a strong damping generates a tomographic result even for a high ‘single’ frequency, which can be a good initial model for full waveform inversion and migration.

  15. Domain walls and ferroelectric reversal in corundum derivatives

    Science.gov (United States)

    Ye, Meng; Vanderbilt, David

    2017-01-01

    Domain walls are the topological defects that mediate polarization reversal in ferroelectrics, and they may exhibit quite different geometric and electronic structures compared to the bulk. Therefore, a detailed atomic-scale understanding of the static and dynamic properties of domain walls is of pressing interest. In this work, we use first-principles methods to study the structures of 180∘ domain walls, both in their relaxed state and along the ferroelectric reversal pathway, in ferroelectrics belonging to the family of corundum derivatives. Our calculations predict their orientation, formation energy, and migration energy and also identify important couplings between polarization, magnetization, and chirality at the domain walls. Finally, we point out a strong empirical correlation between the height of the domain-wall-mediated polarization reversal barrier and the local bonding environment of the mobile A cations as measured by bond-valence sums. Our results thus provide both theoretical and empirical guidance for future searches for ferroelectric candidates in materials of the corundum derivative family.

  16. A frequency-domain derivation of shot-noise

    Science.gov (United States)

    Rice, Frank

    2016-01-01

    A formula for shot-noise is derived in the frequency-domain. The derivation is complete and reasonably rigorous while being appropriate for undergraduate students; it models a sequence of random pulses using Fourier sine and cosine series, and requires some basic statistical concepts. The text here may serve as a pedagogic introduction to the spectral analysis of random processes and may prove useful to introduce students to the logic behind stochastic problems. The concepts of noise power spectral density and equivalent noise bandwidth are introduced.

  17. Effect of Apolipoprotein A-I on ATP Binding Cassette Transporter A1 Degradation and Cholesterol Efflux in THP-1 Macrophage-derived Foam Cells

    Institute of Scientific and Technical Information of China (English)

    Chao-Ke TANG; Chang-Geng RUAN; Yong-Zong YANG; Guo-Hua TANG; Guang-Hui IY; Zuo WANG; Lu-Shan LIU; Shuang WAN; Zhong-Hua YUAN; Xiu-Sheng HE; Jun-Hao YANG

    2004-01-01

    Cholesterol-loaded macrophage foam cells are a central componentof atherosclerotic lesions ATP binding cassette transporter A1(ABCA1),the defective molecule in Tangier disease,mediates the efflux ofphospholipid and cholesterol from cells to apolipoprotein A-I(apoA-I),reversing foam cell formation.This study investigated the effect of apoA-I on ABCA1 degradation and cholesterol efflux in THP-1 macrophagederived foam cells.After exposure of the cultured THP-1 macrophage-derived foam cells to apoA-I for different time,cholesterol efflux,ABCA1 mRNA and protein levels were determined by FJ-2107P type liquid scintillator,RT-PCR and Western blot,respectively.The mean ABCA1 fluorescence intensity on THP-1macrophage-derived foam cells was detected by flow cytometry.Results showed that apoA-I markedly increased ABCAl-mediated cholesterol efflux from THP-1 macrophage-derived foam cells.This was accompanied by an increase in the content of ABCA1.ApoA-I did not alter ABCA 1 mRNA abundance.Significantly,thiol protease inhibitors increased the level ofABCA1 protein and slowed its decay in THP-1macrophage-derived foam cells,whereas none of the proteosome-specific inhibitor lactacystin,other protease inhibitors,or the lysosomal inhibitor NH4Cl showed such effects.The apoA-I-mediated cellular cholesterol efflux was enhanced by thiol protease inhibitors.Our results suggested that thiol protease inhibitors mightprovide an alternative way to upregulate ABCA1 protein.This strategy is especially appealing since it may mimic the stabilizing effect of the natural ligands apoA-I.

  18. Using llama derived single domain antibodies to target botulinum neurotoxins

    Science.gov (United States)

    Swain, Marla D.; Anderson, George P.; Bernstein, Rachael D.; Liu, Jinny L.; Goldman, Ellen R.

    2010-04-01

    Llama serum contains both conventional IgG as well as unique forms of antibody that contain only heavy chains where antigen binding is mediated through a single variable domain. These variable domains can be expressed recombinantly and are referred to as single domain antibodies (sdAb). SdAb are among the smallest known naturally derived antigen binding fragments, possess good solubility, thermal stability, and can refold after heat and chemical denaturation. Llamas were immunized with either BoNT A or B toxoid and phage display libraries prepared. Single domain antibodies (sdAb) that were able to detect botulinum neurotoxin (BoNT) serotypes A and B were selected from their respective libraries. Here, the binders obtained by panning the BoNT B library on either BoNT B toxoid or BoNT B complex toxoid coated plates or BoNT B toxin coupled microspheres are described. Using these panning methods, we selected for binders that showed specificity for BoNT B. Phage displayed binders were screened, moved to a protein expression vector and soluble sdAb was produced. Using a Luminex flow cytometer binders were evaluated in direct binding assays. We have exploited the unique properties of sdAb and used them as biological recognition elements in immuno-based sensors that can detect BoNT B.

  19. The structure of dimeric apolipoprotein A-IV and its mechanism of self-association.

    Science.gov (United States)

    Deng, Xiaodi; Morris, Jamie; Dressmen, James; Tubb, Matthew R; Tso, Patrick; Jerome, W Gray; Davidson, W Sean; Thompson, Thomas B

    2012-05-09

    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 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.

  20. The Structure of Dimeric Apolipoprotein A-IV and Its Mechanism of Self-Association

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Xiaodi; Morris, Jamie; Dressmen, James; Tubb, Matthew R.; Tso, Patrick; Jerome, W. Gray; Davidson, W. Sean; Thompson, Thomas B. (UCIN); (Vanderbilt)

    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.

  1. Specificity determinants in the interaction of apolipoprotein(a) kringles with tetranectin and LDL

    DEFF Research Database (Denmark)

    Caterer, Nigel R; Graversen, Jonas Heilskov; Jacobsen, Christian

    2002-01-01

    Lipoprotein(a) is composed of low density lipoprotein and apolipoprotein(a). Apolipoprotein(a) has evolved from plasminogen and contains 10 different plasminogen kringle 4 homologous domains [KIV(1-110)]. Previous studies indicated that lipoprotein(a) non-covalently binds the N-terminal region...... was similar to that of plasminogen kringle 4 to tetranectin. Only KIV(7) bound to LDL. In order to identify the residues responsible for the difference in specificity between KIV(7) and KIV(10), a number of surface-exposed residues located around the lysine binding clefts were exchanged. Ligand binding...... analysis of these derivatives showed that Y62, and to a minor extent W32 and E56, of KIV(7) are important for LDL binding to KIV(7), whereas R32 and D56 of KIV(10) are required for tetranectin binding of KIV(10)....

  2. Secondary radicals derived from chloramines of apolipoprotein B-100 contribute to HOCl-induced lipid peroxidation of low-density lipoproteins

    DEFF Research Database (Denmark)

    Hazell, L J; Davies, Michael Jonathan; Stocker, R

    1999-01-01

    by an extended period of lipid peroxidation during which further protein oxidation does not occur. The secondary lipid peroxidation process involves EPR-detectable radicals, is attenuated by a radical trap or treatment of HOCl-oxidized LDL with methionine, and occurs less rapidly when the lipoprotein...... was depleted of alpha-tocopherol. The initial reaction of low concentrations of HOCl (400-fold or 800-fold molar excess) with LDL therefore seems to occur primarily by two-electron reactions with side-chain sites on apolipoprotein B-100. Some of the initial reaction products, identified as lysine...

  3. Apolipoprotein E LDL receptor-binding domain-containing high-density lipoprotein: a nanovehicle to transport curcumin, an antioxidant and anti-amyloid bioflavonoid.

    Science.gov (United States)

    Khumsupan, Panupon; Ramirez, Ricardo; Khumsupan, Darin; Narayanaswami, Vasanthy

    2011-01-01

    Curcumin is an antioxidant and anti-inflammatory bioflavonoid that has been recently identified as an anti-amyloid agent as well. To make it more available in its potent form as a potential amyloid disaggregation agent, we employed high-density lipoproteins (HDL), which are lipid-protein complexes that transport plasma cholesterol, to transport curcumin. The objective of this study was to employ reconstituted HDL containing human apoE3 N-terminal (NT) domain, as a vehicle to transport curcumin. The NT domain serves as a ligand to mediate binding and uptake of lipoprotein complexes via the low-density lipoprotein receptor (LDLr) family of proteins located at the cell surface. Reconstituted HDL was prepared with phospholipids and recombinant apoE3-NT domain in the absence or presence of curcumin. Non-denaturing polyacrylamide gel electrophoresis indicated that the molecular mass and Stokes' diameter of HDL bearing curcumin were ~670kDa and ~17nm, respectively, while electron microscopy revealed the presence of discoidal particles. Fluorescence emission spectra of HDL bearing (the intrinsically fluorescent) curcumin indicated that the wavelength of maximal fluorescence emission (λ(max)) of curcumin was ~495nm, which is highly blue-shifted compared to λ(max) of curcumin in solvents of varying polarity (λ(max) ranging from 515-575nm) or in aqueous buffers. In addition, an enormous enhancement in fluorescence emission intensity was noted in curcumin-containing HDL compared to curcumin in aqueous buffers. Curcumin fluorescence emission was quenched to a significant extent by lipid-based quenchers but not by aqueous quenchers. These observations indicate that curcumin has partitioned efficiently into the hydrophobic milieu of the phospholipid bilayer of HDL. Functional assays indicated that the LDLr-binding ability of curcumin-containing HDL with apoE3-NT is similar to that of HDL without curcumin. Taken together, we report that apoE-containing HDL has a tremendous

  4. Clinical chemistry of common apolipoprotein E isoforms

    NARCIS (Netherlands)

    Brouwer, DAJ; vanDoormaal, JJ; Muskiet, FAJ

    1996-01-01

    Apolipoprotein E plays a central role in clearance of lipoprotein remnants by serving as a ligand for low-density lipoprotein and apolipoprotein E receptors. Three common alleles (apolipoprotein E(2), E(3) and E(4)) give rise to six phenotypes. Apolipoprotein E(3) is the ancestral form. Common apoli

  5. Executive function performance and change in aging is predicted by apolipoprotein E, intensified by catechol-O-methyltransferase and brain-derived neurotrophic factor, and moderated by age and lifestyle.

    Science.gov (United States)

    Sapkota, Shraddha; Bäckman, Lars; Dixon, Roger A

    2017-01-03

    Recent studies have reported several genetic, health, and aging interaction effects in predicting cognitive performance and change. We used an accelerated longitudinal design to examine interactions among genetic, lifestyle, and aging for executive function (EF) in non-demented older adults (n = 634; age range = 53-95 years). The polymorphisms were apolipoprotein E (APOE), catechol-O-methyltransferase (COMT), and brain-derived neurotrophic factor (BDNF). We tested (1) independent and additive effects of APOE, COMT, and BDNF and (2) APOE effect modification for COMT + BDNF, on EF performance and 9-year change as separated by age and lifestyle activities. First, APOE ε4+ carriers had poorer EF performance and steeper 9-year decline. Second, APOE ε4+ carriers with (1) BDNF Met/Met genotype and (2) increasing allelic risk in the COMT + BDNF risk panel had poorer EF performance; these effects were moderated by lifestyle activities (composite of everyday social, physical, and cognitive activities). Examining APOE effect modification for COMT + BDNF risk panel effects with other moderating factors may help identify complex neurobiological and genetic underpinnings of polygenic phenotypes such as EF in aging.

  6. Traces, extensions and co-normal derivatives for elliptic systems on Lipschitz domains

    OpenAIRE

    Mikhailov, SE

    2011-01-01

    This is the post-print version of the article. The official published version can be accessed from the link below - Copyright @ 2011 Elsevier For functions from the Sobolev space H^s(\\Omega­), 1/2 < s < 3/2 , definitions of non-unique generalized and unique canonical co-normal derivative are considered, which are related to possible extensions of a partial differential operator and its right hand side from the domain­, where they are prescribed, to the domain boundary, where they are not. ...

  7. Fibroblasts that reside in mouse and frog injured peripheral nerves produce apolipoproteins.

    Science.gov (United States)

    Saada, A; Dunaevsky-Hutt, A; Aamar, A; Reichert, F; Rotshenker, S

    1995-05-01

    Apolipoprotein synthesis and secretion is upregulated in wallerian degenerating peripheral nerves. A commonly expressed view has been that macrophages are solely responsible for their production. In the present study we provide evidence that (1) nerve-derived fibroblasts contribute to apolipoprotein production, (2) apolipoprotein production is confined to regions where myelin destruction and phagocytosis occur, and (3) some experimental procedures are detrimental for the production of apolipoproteins. Apolipoprotein production was studied in C57BL/6/NHSD (N) and C57/BL/6-WLD/OLA/NHSD (W) mice that display, respectively, rapid and slow progression of wallerian degeneration. In N nerves, apolipoprotein E (apo-E) is produced during in vitro and in vivo degeneration, and in vivo after freeze damage. In W nerves, apo-E is produced at the injury region where degeneration occurs but not farther distally where degeneration fails to develop. Apo-E is also produced in W nerves during in vitro degeneration and in vivo after freeze damage. In culture, N and W mice nerve-derived fibroblasts, but neither macrophages nor Schwann cells produced apo-E. Two apolipoproteins are produced in in vivo wallerian degenerating and freeze-damaged frog nerves, i.e., apo-39 and apo-29. Only apo-39 is produced in in vitro degenerating nerves. Neither apo-39 nor apo-29 is produced during in vivo degeneration in diffusion chambers. In culture, apo-39 is produced by nerve-derived fibroblasts and macrophages but not by Schwann cells.

  8. Thermal stability and refolding capability of shark derived single domain antibodies.

    Science.gov (United States)

    Liu, Jinny L; Zabetakis, Dan; Brown, Jazmine C; Anderson, George P; Goldman, Ellen R

    2014-06-01

    Single-domain antibodies (sdAb) from camelids and sharks represent the smallest immunoglobulin-based functional binding domains, and are known for their thermal stability and ability to refold after denaturation. Whereas target-binding sdAb have been derived from both immunized and naïve sharks and camelids, the stability of camelid-derived sdAb have been evaluated much more extensively. To address this disparity we characterized 20 sdAb derived from spiny dogfish shark and smooth dogfish shark in terms of their protein production, melting temperature and ability to refold after heat denaturation. Using the same expression system and protocol as we follow to produce camelid sdAb, production of the shark sdAb was quite poor, often resulting in less than a tenth of the typical yield for camelid sdAb. We measured the melting temperature of each of the sdAb. Similar to camelid sdAb, the shark-derived sdAb, showed a range of melting temperature values from 42°C to 77°C. Also similar to what has been observed in camelids, the sdAb from both shark species showed a range of ability to refold after heat denaturation. This work demonstrated that although shark sdAb can possess high melting temperatures and refolding ability, no clear advantage over sdAb derived from camelids in terms of thermostability and renaturation was obtained.

  9. N-methyl-D-aspartate receptor inhibition by an apolipoprotein E-derived peptide relies on low-density lipoprotein receptor-associated protein.

    Science.gov (United States)

    Sheng, Zhenyu; Prorok, Mary; Brown, Brigid E; Castellino, Francis J

    2008-08-01

    The effects of a synthetic apoE peptide, viz., residues 133-149 (apoE[133-149]), a mimetic that comprises the apoE receptor binding domain, on N-methyl-D-aspartate (NMDA)/glycine-induced ion flow through NMDA receptor (NMDAR) channels, have been investigated. The activity of apoE[133-149] was found to depend on the low-density lipoprotein receptor-related protein (LRP). Competition experiments with receptor-associated protein (RAP) and activated alpha(2)-macroglobulin (alpha(2)M*), two proteins that compete for apoE binding to LRP, demonstrate that apoE[133-149] inhibition of NMDAR function is mediated at a locus in LRP that overlaps with the binding sites of RAP and alpha(2)M*. A coreceptor of LRP, cell surface heparin sulfate proteoglycan, did not function in this system. Additional electrophysiology experiments demonstrated that the inhibitory potency of apoE[133-149] was threefold greater for NMDAR-transfected wild-type Chinese hamster ovary (CHO) cells compared with NMDAR-transfected CHO cells deficient in LRP. Studies with truncation and replacement variants of the apoE peptide demonstrated that the NMDAR inhibitory properties of these peptides correlate with their binding affinities for LRP. These novel results indicate that apoE functions as an inhibitor of NMDAR ion channels indirectly via LRP, and are suggestive of a participatory role for LRP in NMDAR-based neuropathies.

  10. In Situ Visualization of Lipid Raft Domains by Fluorescent Glycol Chitosan Derivatives.

    Science.gov (United States)

    Jiang, Yao-Wen; Guo, Hao-Yue; Chen, Zhan; Yu, Zhi-Wu; Wang, Zhifei; Wu, Fu-Gen

    2016-07-01

    Lipid rafts are highly ordered small microdomains mainly composed of glycosphingolipids, cholesterol, and protein receptors. Optically distinguishing lipid raft domains in cell membranes would greatly facilitate the investigations on the structure and dynamics of raft-related cellular behaviors, such as signal transduction, membrane transport (endocytosis), adhesion, and motility. However, current strategies about the visualization of lipid raft domains usually suffer from the low biocompatibility of the probes, invasive detection, or ex situ observation. At the same time, naturally derived biomacromolecules have been extensively used in biomedical field and their interaction with cells remains a long-standing topic since it is closely related to various fundamental studies and potential applications. Herein, noninvasive visualization of lipid raft domains in model lipid bilayers (supported lipid bilayers and giant unilamellar vesicles) and live cells was successfully realized in situ using fluorescent biomacromolecules: the fluorescein isothiocyanate (FITC)-labeled glycol chitosan molecules. We found that the lipid raft domains in model or real membranes could be specifically stained by the FITC-labeled glycol chitosan molecules, which could be attributed to the electrostatic attractive interaction and/or hydrophobic interaction between the probes and the lipid raft domains. Since the FITC-labeled glycol chitosan molecules do not need to completely insert into the lipid bilayer and will not disturb the organization of lipids, they can more accurately visualize the raft domains as compared with other fluorescent dyes that need to be premixed with the various lipid molecules prior to the fabrication of model membranes. Furthermore, the FITC-labeled glycol chitosan molecules were found to be able to resist cellular internalization and could successfully visualize rafts in live cells. The present work provides a new way to achieve the imaging of lipid rafts and also

  11. Apolipoprotein Mimetic Peptides: A New Approach for the Treatment of Asthma

    Directory of Open Access Journals (Sweden)

    Xianglan eYao

    2012-03-01

    Full Text Available New treatments are needed for severe asthmatics to improve disease control and avoid severe toxicities associated with oral corticosteroids. We have used a murine model of house dust mite (HDM-induced asthma to identify steroid-unresponsive genes that might represent targets for new therapeutic approaches for severe asthma. This strategy identified apolipoprotein E as a steroid-unresponsive gene with increased mRNA expression in the lungs of HDM-challenged mice. Furthermore, apolipoprotein E functioned as an endogenous negative regulator of airway hyperreactivity and goblet cell hyperplasia in experimental HDM-induced asthma. The ability of apolipoprotein E, which is expressed by lung macrophages, to attenuate AHR and goblet cell hyperplasia is mediated by low density lipoprotein (LDL receptors expressed by airway epithelial cells. Consistent with this, administration of an apolipoprotein E mimetic peptide, corresponding to amino acids 130 to 149 of the LDL receptor-binding domain of the holo-apoE protein, significantly reduced AHR and goblet cell hyperplasia in HDM-challenged apoE-/- mice. These findings identified the apolipoprotein E - LDL receptor pathway as a new druggable target for asthma that can be activated by administration of apoE mimetic peptides. Similarly, apolipoprotein A-I may have therapeutic potential in asthma based upon its anti-inflammatory, anti-oxidative and anti-fibrotic properties. Furthermore, administration of apolipoprotein A-I mimetic peptides has attenuated airway inflammation, airway remodeling and airway hyperreactivity in murine models of experimental asthma. Thus, site-directed delivery of inhaled apolipoprotein E or apolipoprotein A-I mimetic peptides may represent novel treatment approaches that can be developed for asthma, including severe disease.

  12. Second-order domain derivative of normal-dependent boundary integrals

    KAUST Repository

    Balzer, Jonathan

    2010-03-17

    Numerous reconstruction tasks in (optical) surface metrology allow for a variational formulation. The occurring boundary integrals may be interpreted as shape functions. The paper is concerned with the second-order analysis of such functions. Shape Hessians of boundary integrals are considered difficult to find analytically because they correspond to third-order derivatives of an, in a sense equivalent, domain integral. We complement previous results by considering cost functions depending explicitly on the surface normal. The correctness and practicability of our calculations are verified in the context of a Newton-type shape reconstruction method. © 2010 Birkhäuser / Springer Basel AG.

  13. Derivation and implementation of the boundary integral formula for the convective acoustic wave equation in time domain.

    Science.gov (United States)

    Lee, Yong Woo; Lee, Duck Joo

    2014-12-01

    Kirchhoff's formula for the convective wave equation is derived using the generalized function theory. The generalized convective wave equation for a stationary surface is obtained, and the integral formulation, the convective Kirchhoff's formula, is derived. The formula has a similar form to the classical Kirchhoff's formula, but an additional term appears due to a moving medium effect. For convenience, the additional term is manipulated to a final form as the classical Kirchhoff's formula. The frequency domain boundary integral can be obtained from the current time domain boundary integral form. The derived formula is verified by comparison with the analytic solution of source in the uniform flow. The formula is also utilized as a boundary integral equation. Time domain boundary element method (BEM) analysis using the boundary integral equation is conducted, and the results show good agreement with the analytical solution. The formula derived here can be useful for sound radiation and scattering by arbitrary bodies in a moving medium in the time domain.

  14. Attractors of the Derivative Complex Ginzburg-Landau Equation in Unbounded Domains

    Institute of Scientific and Technical Information of China (English)

    GUO Bo-ling; HAN Yong-qian

    2005-01-01

    @@ We consider the following initial boundary problem of derivative complex Ginzburg-Landau (DCGL) equation ut-(a1+ia2)△u-X0u+(b1+ib2)|u|2σu+|u|2λ·▽u+u2μ·▽u=g(x), (1) u(x,t = 0) = u0(x), u| Ω = 0 (2) in an unbounded domain Ω R2. Here u is a complex valued function of (x, t) ∈Ω× R +,a1 > 0, b1 > 0, σ> 0, a2, b2 ∈ R, λ = (λ1, λ2) and μ = (μ1,μ2) are complex constant vector.

  15. Attractors of derivative complex Ginzburg-Landau equation in unbounded domains

    Institute of Scientific and Technical Information of China (English)

    GUO Boling; HAN Yongqian

    2007-01-01

    The Ginzburg-Landau-type complex equations are simplified mathematical models for various pattern formation systems in mechanics, physics, and chemistry. In this paper, the derivative complex Ginzburg- Landau (DCGL) equation in an unbounded domain ΩС R2 is studied. We extend the Gagliardo-Nirenberg inequality to the weighted Sobolev spaces introduced by S. V. Zelik. Applied this Gagliardo-Nirenberg inequality of the weighted Sobolev spaces and based on the technique for the semi-linear system of parabolic equations which has been developed by M. A. Efendiev and S. V. Zelik, the global attractor in the corresponding phase space is constructed, the upper bound of its Kolmogorov's ε-entropy is obtained, and the spatial chaos of the attractor for DCGL equation in R2 is detailed studied.

  16. REGULARITY ESTIMATES FOR THE OBLIQUE DERIVATIVE PROBLEM ON NON-SMOOTH DOMAINS (I)

    Institute of Scientific and Technical Information of China (English)

    GUANPENGFEI; E.SAWYER

    1995-01-01

    The authors consider the existence and regularity of the oblique derivative problem:{Pu=f inΩ,→tu=g onэΩ where P is a soc~ad order elliptic differential operator on Rn, Ω is a bounded domain in Rn and →t is a unit vector field on the bouudary of Ω (which may be tangential to the boundary). Allabove are assumed with limited smoothnees. The authors show that solution u has an ellipticgain from f in Holder spaces (Theorem 1.1). The authors obtain Ln regualrity of solutionin Tbeorem 1.3, which generalizes the results in [7] to the limited smooth case. Some of the application nonlinear problems are also discussed.

  17. BRAFV600E Kinase Domain Duplication Identified in Therapy-Refractory Melanoma Patient-Derived Xenografts

    Directory of Open Access Journals (Sweden)

    Kristel Kemper

    2016-06-01

    Full Text Available The therapeutic landscape of melanoma is improving rapidly. Targeted inhibitors show promising results, but drug resistance often limits durable clinical responses. There is a need for in vivo systems that allow for mechanistic drug resistance studies and (combinatorial treatment optimization. Therefore, we established a large collection of patient-derived xenografts (PDXs, derived from BRAFV600E, NRASQ61, or BRAFWT/NRASWT melanoma metastases prior to treatment with BRAF inhibitor and after resistance had occurred. Taking advantage of PDXs as a limitless source, we screened tumor lysates for resistance mechanisms. We identified a BRAFV600E protein harboring a kinase domain duplication (BRAFV600E/DK in ∼10% of the cases, both in PDXs and in an independent patient cohort. While BRAFV600E/DK depletion restored sensitivity to BRAF inhibition, a pan-RAF dimerization inhibitor effectively eliminated BRAFV600E/DK-expressing cells. These results illustrate the utility of this PDX platform and warrant clinical validation of BRAF dimerization inhibitors for this group of melanoma patients.

  18. Small molecule structure correctors abolish detrimental effects of apolipoprotein E4 in cultured neurons.

    Science.gov (United States)

    Chen, Hung-Kai; Liu, Zhaoping; Meyer-Franke, Anke; Brodbeck, Jens; Miranda, Rene D; McGuire, James G; Pleiss, Michael A; Ji, Zhong-Sheng; Balestra, Maureen E; Walker, David W; Xu, Qin; Jeong, Dah-eun; Budamagunta, Madhu S; Voss, John C; Freedman, Stephen B; Weisgraber, Karl H; Huang, Yadong; Mahley, Robert W

    2012-02-17

    Apolipoprotein E4 (apoE4), the major genetic risk factor for late onset Alzheimer disease, assumes a pathological conformation, intramolecular domain interaction. ApoE4 domain interaction mediates the detrimental effects of apoE4, including decreased mitochondrial cytochrome c oxidase subunit 1 levels, reduced mitochondrial motility, and reduced neurite outgrowth in vitro. Mutant apoE4 (apoE4-R61T) lacks domain interaction, behaves like apoE3, and does not cause detrimental effects. To identify small molecules that inhibit domain interaction (i.e. structure correctors) and reverse the apoE4 detrimental effects, we established a high throughput cell-based FRET primary assay that determines apoE4 domain interaction and secondary cell- and function-based assays. Screening a ChemBridge library with the FRET assay identified CB9032258 (a phthalazinone derivative), which inhibits domain interaction in neuronal cells. In secondary functional assays, CB9032258 restored mitochondrial cytochrome c oxidase subunit 1 levels and rescued impairments of mitochondrial motility and neurite outgrowth in apoE4-expressing neuronal cells. These benefits were apoE4-specific and dose-dependent. Modifying CB9032258 yielded well defined structure-activity relationships and more active compounds with enhanced potencies in the FRET assay (IC(50) of 23 and 116 nm, respectively). These compounds efficiently restored functional activities of apoE4-expressing cells in secondary assays. An EPR binding assay showed that the apoE4 structure correction resulted from direct interaction of a phthalazinone. With these data, a six-feature pharmacophore model was constructed for future drug design. Our results serve as a proof of concept that pharmacological intervention with apoE4 structure correctors negates apoE4 detrimental effects in neuronal cells and could be further developed as an Alzheimer disease therapeutic.

  19. Novel activation domain derived from Che-1 cofactor coupled with the artificial protein Jazz drives utrophin upregulation.

    Science.gov (United States)

    Desantis, Agata; Onori, Annalisa; Di Certo, Maria Grazia; Mattei, Elisabetta; Fanciulli, Maurizio; Passananti, Claudio; Corbi, Nicoletta

    2009-02-01

    Our aim is to upregulate the expression level of the dystrophin related gene utrophin in Duchenne muscular dystrophy, thus complementing the lack of dystrophin functions. To this end, we have engineered synthetic zinc finger based transcription factors. We have previously shown that the artificial three-zinc finger protein named Jazz fused with the Vp16 activation domain, is able to bind utrophin promoter A and to increase the endogenous level of utrophin in transgenic mice. Here, we report on an innovative artificial protein, named CJ7, that consists of Jazz DNA binding domain fused to a novel activation domain derived from the regulatory multivalent adaptor protein Che-1/AATF. This transcriptional activation domain is 100 amino acids in size and it is very powerful as compared to the Vp16 activation domain. We show that CJ7 protein efficiently promotes transcription and accumulation of the acetylated form of histone H3 on the genomic utrophin promoter locus.

  20. Deriving a probabilistic syntacto-semantic grammar for biomedicine based on domain-specific terminologies.

    Science.gov (United States)

    Fan, Jung-Wei; Friedman, Carol

    2011-10-01

    Biomedical natural language processing (BioNLP) is a useful technique that unlocks valuable information stored in textual data for practice and/or research. Syntactic parsing is a critical component of BioNLP applications that rely on correctly determining the sentence and phrase structure of free text. In addition to dealing with the vast amount of domain-specific terms, a robust biomedical parser needs to model the semantic grammar to obtain viable syntactic structures. With either a rule-based or corpus-based approach, the grammar engineering process requires substantial time and knowledge from experts, and does not always yield a semantically transferable grammar. To reduce the human effort and to promote semantic transferability, we propose an automated method for deriving a probabilistic grammar based on a training corpus consisting of concept strings and semantic classes from the Unified Medical Language System (UMLS), a comprehensive terminology resource widely used by the community. The grammar is designed to specify noun phrases only due to the nominal nature of the majority of biomedical terminological concepts. Evaluated on manually parsed clinical notes, the derived grammar achieved a recall of 0.644, precision of 0.737, and average cross-bracketing of 0.61, which demonstrated better performance than a control grammar with the semantic information removed. Error analysis revealed shortcomings that could be addressed to improve performance. The results indicated the feasibility of an approach which automatically incorporates terminology semantics in the building of an operational grammar. Although the current performance of the unsupervised solution does not adequately replace manual engineering, we believe once the performance issues are addressed, it could serve as an aide in a semi-supervised solution.

  1. The CRM domain: an RNA binding module derived from an ancient ribosome-associated protein.

    Science.gov (United States)

    Barkan, Alice; Klipcan, Larik; Ostersetzer, Oren; Kawamura, Tetsuya; Asakura, Yukari; Watkins, Kenneth P

    2007-01-01

    The CRS1-YhbY domain (also called the CRM domain) is represented as a stand-alone protein in Archaea and Bacteria, and in a family of single- and multidomain proteins in plants. The function of this domain is unknown, but structural data and the presence of the domain in several proteins known to interact with RNA have led to the proposal that it binds RNA. Here we describe a phylogenetic analysis of the domain, its incorporation into diverse proteins in plants, and biochemical properties of a prokaryotic and eukaryotic representative of the domain family. We show that a bacterial member of the family, Escherichia coli YhbY, is associated with pre-50S ribosomal subunits, suggesting that YhbY functions in ribosome assembly. GFP fused to a single-domain CRM protein from maize localizes to the nucleolus, suggesting that an analogous activity may have been retained in plants. We show further that an isolated maize CRM domain has RNA binding activity in vitro, and that a small motif shared with KH RNA binding domains, a conserved "GxxG" loop, contributes to its RNA binding activity. These and other results suggest that the CRM domain evolved in the context of ribosome function prior to the divergence of Archaea and Bacteria, that this function has been maintained in extant prokaryotes, and that the domain was recruited to serve as an RNA binding module during the evolution of plant genomes.

  2. Automatic derivation of domain terms and concept location based on the analysis of the identifiers

    CERN Document Server

    Vaclavik, Peter; Mezei, Marek

    2010-01-01

    Developers express the meaning of the domain ideas in specifically selected identifiers and comments that form the target implemented code. Software maintenance requires knowledge and understanding of the encoded ideas. This paper presents a way how to create automatically domain vocabulary. Knowledge of domain vocabulary supports the comprehension of a specific domain for later code maintenance or evolution. We present experiments conducted in two selected domains: application servers and web frameworks. Knowledge of domain terms enables easy localization of chunks of code that belong to a certain term. We consider these chunks of code as "concepts" and their placement in the code as "concept location". Application developers may also benefit from the obtained domain terms. These terms are parts of speech that characterize a certain concept. Concepts are encoded in "classes" (OO paradigm) and the obtained vocabulary of terms supports the selection and the comprehension of the class' appropriate identifiers. ...

  3. Levels of Circulating MMCN-151, a Degradation Product of Mimecan, Reflect Pathological Extracellular Matrix Remodeling in Apolipoprotein E Knockout Mice

    DEFF Research Database (Denmark)

    Barascuk, N; Vassiliadis, E; Zheng, Qiuju;

    2011-01-01

    Arterial extracellular matrix (ECM) remodeling by matrix metalloproteinases (MMPs) is one of the major hallmarks of atherosclerosis. Mimecan, also known as osteoglycin has been implicated in the integrity of the ECM. This study assessed the validity of an enzyme-linked immunosorbent assay (ELISA)......) developed to measure a specific MMP12-derived fragment of mimecan, MMCN-151, in apolipoprotein-E knockout (ApoE-KO) mice....

  4. Targeting diverse protein-protein interaction interfaces with α/β-peptides derived from the Z-domain scaffold.

    Science.gov (United States)

    Checco, James W; Kreitler, Dale F; Thomas, Nicole C; Belair, David G; Rettko, Nicholas J; Murphy, William L; Forest, Katrina T; Gellman, Samuel H

    2015-04-14

    Peptide-based agents derived from well-defined scaffolds offer an alternative to antibodies for selective and high-affinity recognition of large and topologically complex protein surfaces. Here, we describe a strategy for designing oligomers containing both α- and β-amino acid residues ("α/β-peptides") that mimic several peptides derived from the three-helix bundle "Z-domain" scaffold. We show that α/β-peptides derived from a Z-domain peptide targeting vascular endothelial growth factor (VEGF) can structurally and functionally mimic the binding surface of the parent peptide while exhibiting significantly decreased susceptibility to proteolysis. The tightest VEGF-binding α/β-peptide inhibits the VEGF165-induced proliferation of human umbilical vein endothelial cells. We demonstrate the versatility of this strategy by showing how principles underlying VEGF signaling inhibitors can be rapidly extended to produce Z-domain-mimetic α/β-peptides that bind to two other protein partners, IgG and tumor necrosis factor-α. Because well-established selection techniques can identify high-affinity Z-domain derivatives from large DNA-encoded libraries, our findings should enable the design of biostable α/β-peptides that bind tightly and specifically to diverse targets of biomedical interest. Such reagents would be useful for diagnostic and therapeutic applications.

  5. Diagnosis and treatment of apolipoprotein B dyslipoproteinemias.

    NARCIS (Netherlands)

    Sniderman, A.; Couture, P.; Graaf, J. de

    2010-01-01

    Conventionally, atherogenic dyslipidemias have been defined by elevated levels of triglyceride and/or LDL cholesterol. However, cholesterol and triglycerides are not metabolically and physically independent entities. Rather, they are constituents of the atherogenic apolipoprotein B (apoB) particles,

  6. Targeting diverse protein–protein interaction interfaces with α/β-peptides derived from the Z-domain scaffold

    Energy Technology Data Exchange (ETDEWEB)

    Checco, James W.; Kreitler, Dale F.; Thomas, Nicole C.; Belair, David G.; Rettko, Nicholas J.; Murphy, William L.; Forest, Katrina T.; Gellman, Samuel H. (UW)

    2015-04-14

    Peptide-based agents derived from well-defined scaffolds offer an alternative to antibodies for selective and high-affinity recognition of large and topologically complex protein surfaces. Here, we describe a strategy for designing oligomers containing both α- and β-amino acid residues ("α/β-peptides") that mimic several peptides derived from the three-helix bundle "Z-domain" scaffold. We show that α/β-peptides derived from a Z-domain peptide targeting vascular endothelial growth factor (VEGF) can structurally and functionally mimic the binding surface of the parent peptide while exhibiting significantly decreased susceptibility to proteolysis. The tightest VEGF-binding α/β-peptide inhibits the VEGF₁₆₅-induced proliferation of human umbilical vein endothelial cells. We demonstrate the versatility of this strategy by showing how principles underlying VEGF signaling inhibitors can be rapidly extended to produce Z-domain–mimetic α/β-peptides that bind to two other protein partners, IgG and tumor necrosis factor-α. Because well-established selection techniques can identify high-affinity Z-domain derivatives from large DNA-encoded libraries, our findings should enable the design of biostable α/β-peptides that bind tightly and specifically to diverse targets of biomedical interest. Such reagents would be useful for diagnostic and therapeutic applications.

  7. Solution structure of telomere binding domain of AtTRB2 derived from Arabidopsis thaliana

    Energy Technology Data Exchange (ETDEWEB)

    Yun, Ji-Hye [Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749 (Korea, Republic of); Lee, Won Kyung [Department of Systems Biology, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749 (Korea, Republic of); Kim, Heeyoun [Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749 (Korea, Republic of); Kim, Eunhee; Cheong, Chaejoon [Magnetic Resonance Team, Korea Basic Science Institute (KBSI), Ochang, Chungbuk 363-883 (Korea, Republic of); Cho, Myeon Haeng [Department of Systems Biology, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749 (Korea, Republic of); Lee, Weontae, E-mail: wlee@spin.yonsei.ac.kr [Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749 (Korea, Republic of)

    2014-09-26

    Highlights: • We have determined solution structure of Myb domain of AtTRB2. • The Myb domain of AtTRB2 is located in the N-terminal region. • The Myb domain of AtTRB2 binds to plant telomeric DNA without fourth helix. • Helix 2 and 3 of the Myb domain of AtTRB2 are involved in DNA recognition. • AtTRB2 is a novel protein distinguished from other known plant TBP. - Abstract: Telomere homeostasis is regulated by telomere-associated proteins, and the Myb domain is well conserved for telomere binding. AtTRB2 is a member of the SMH (Single-Myb-Histone)-like family in Arabidopsis thaliana, having an N-terminal Myb domain, which is responsible for DNA binding. The Myb domain of AtTRB2 contains three α-helices and loops for DNA binding, which is unusual given that other plant telomere-binding proteins have an additional fourth helix that is essential for DNA binding. To understand the structural role for telomeric DNA binding of AtTRB2, we determined the solution structure of the Myb domain of AtTRB2 (AtTRB2{sub 1–64}) using nuclear magnetic resonance (NMR) spectroscopy. In addition, the inter-molecular interaction between AtTRB2{sub 1–64} and telomeric DNA has been characterized by the electrophoretic mobility shift assay (EMSA) and NMR titration analyses for both plant (TTTAGGG)n and human (TTAGGG)n telomere sequences. Data revealed that Trp28, Arg29, and Val47 residues located in Helix 2 and Helix 3 are crucial for DNA binding, which are well conserved among other plant telomere binding proteins. We concluded that although AtTRB2 is devoid of the additional fourth helix in the Myb-extension domain, it is able to bind to plant telomeric repeat sequences as well as human telomeric repeat sequences.

  8. Polymorphisms in apolipoprotein B and risk of ischemic stroke

    DEFF Research Database (Denmark)

    Benn, Marianne; Nordestgaard, Børge G; Jensen, Jan Skov;

    2007-01-01

    Apolipoprotein B levels associate with risk of ischemic stroke. APOB polymorphisms may influence levels of apolipoprotein B and low-density lipoprotein (LDL), but whether they associate with risk of ischemic stroke is unknown.......Apolipoprotein B levels associate with risk of ischemic stroke. APOB polymorphisms may influence levels of apolipoprotein B and low-density lipoprotein (LDL), but whether they associate with risk of ischemic stroke is unknown....

  9. Apical secretion of apolipoproteins from enterocytes

    DEFF Research Database (Denmark)

    Danielsen, E M; Hansen, Gert Helge; Poulsen, Mona Dam

    1993-01-01

    Synthesis and secretion of apolipoproteins in pig small intestine was studied by pulse-chase labeling of jejunal segments, kept in organ culture. Apo A-1 and apo B-48 were the two major proteins released, constituting 25 and 10%, respectively, of the total amount of labeled protein in the mucosal...... that enterocytes release most of their newly made free apo A-1 and a significant portion of apo B-48 by exocytosis via the brush border membrane into the intestinal lumen. Fat absorption reduced apolipoprotein secretion to the medium and induced the formation of chylomicrons, containing apo A-1 at their surface......-side medium where they appeared with a t1/2 of 50-60 min. Using tissue from fasting animals, > 85% of newly synthesized apo A-1 and about one third of apo B-48 was released to the mucosal-side medium. Newly synthesized apolipoprotein that remained associated with the intestinal segment accumulated...

  10. Phage Display Derived IgNAR V Region Binding Domains for Therapeutic Development.

    Science.gov (United States)

    Ubah, Obinna C; Barelle, Caroline J; Buschhaus, Magdalena J; Porter, Andrew J

    2016-01-01

    Phage display technology has revolutionized the science of drug discovery by transforming the generation and manipulation of ligands, such as antibody fragments, enzymes, and peptides. The basis of this technology is the expression of recombinant proteins or peptides fused to a phage coat protein, and subsequent isolation of ligands based on a variety of catalytic, physicochemical/binding kinetic and/or biological characteristics. An incredible number of diagnostic and therapeutic domains have been successfully isolated using phage display technology. The variable domain of the New Antigen Receptors (VNAR) found in cartilaginous fish, is also amenable to phage display selection. Whilst not an antibody, VNARs are unquestionable the oldest (450 million years), and smallest antigen binding, single-domains so far identified in the vertebrate kingdom. Their role as an integral part of the adaptive immune system of sharks has been well established, enhancing our understanding of the evolutionary origins of humoral immunity and the unusual but divergent ancestry of the VNARs themselves. VNARs exhibit remarkable physicochemical properties, such as small size, stability in extreme conditions, solubility, molecular flexibility, high affinity and selectivity for target. The purpose of this review is to illustrate the important role phage display has played in the isolation and characterization of potent therapeutic and diagnostic VNAR domains.

  11. Altered small-world anatomical networks in Apolipoprotein-E4 (ApoE4) carriers using MRI.

    Science.gov (United States)

    Goryawala, Mohammed; Zhou, Qi; Duara, Ranjan; Loewenstein, David; Cabrerizo, Mercedes; Barker, Warren; Adjouadi, Malek

    2014-01-01

    Apolipoprotein E (ApoE) gene and primarily its allele e4 have been identified as a risk factor for Alzheimer's disease (AD). The prevalence of the gene in 25-30% in the population makes it essential to estimate its role in neuroregulation and its impact on distributed brain networks. In this study, we provide computational neuroanatomy based interpretation of large-scale and small-world cortical networks in cognitive normal (CN) subjects with differing Apolipoprotein-E4 (ApoE4) gene expression. We estimated large-scale anatomical networks from cortical thickness measurements derived from magnetic resonance imaging in 147 CN subjects explored in relation to ApoE4 genotype (e4+ carriers (n=41) versus e4- non-carriers (n=106)). Brain networks were constructed by thresholding cortical thickness correlation matrices of 68 bilateral regions of the brain analyzed using well-established graph theoretical approaches. Compared to ApoE4 non-carriers, carriers showed increased interregional correlation coefficients in regions like precentral, superior frontal and inferior temporal regions. Interestingly most of the altered connections were intra-hemispheric limited primarily to the right hemisphere. Furthermore, ApoE4 carriers demonstrated abnormal small-world architecture in the cortical networks with increased clustering coefficient and path lengths as compared to non-carrier, suggesting a less optimal topological organization. Additionally non-carriers demonstrated higher betweenness in regions such as middle temporal, para-hippocampal gyrus, posterior cingulate and insula of the default mode network (DMN), also seen in subjects with AD and mild cognitive impairment (MCI). The results suggest that the complex morphological cortical connectivity patterns are altered in ApoE4 carriers as compared to non-carriers, providing evidence for disruption of integrity in large-scale anatomical brain networks.

  12. Rice husk-derived graphene with nano-sized domains and clean edges.

    Science.gov (United States)

    Muramatsu, Hiroyuki; Kim, Yoong Ahm; Yang, Kap-Seung; Cruz-Silva, Rodolfo; Toda, Ikumi; Yamada, Takumi; Terrones, Mauricio; Endo, Morinobu; Hayashi, Takuya; Saitoh, Hidetoshi

    2014-07-23

    A new synthetic method is demonstrated for transforming rice husks into bulk amounts of graphene through its calcination and chemical activation. The bulk sample consists of crystalline nano-sized graphene and corrugated individual graphene sheets; the material generally contains one, two, or a few layers, and corrugated graphene domains are typically observed in monolayers containing topological defects within the hexagonal lattice and edges. Both types of graphenes exhibit atomically smooth surfaces and edges.

  13. Rat apolipoprotein A-IV metabolism

    NARCIS (Netherlands)

    G.M. Dallinga-Thie (Geesje)

    1986-01-01

    textabstractEarlier studies by Van 't Hoeft et al. (85, 160), in our laboratory, mainly focussed upon the catabolism of HDL apolipoproteins A-I and E. They found that the kidneys were an important organ involved in the catabolism of these proteins together with the liver. The present thesis mainly d

  14. Common and Rare Alleles in Apolipoprotein B Contribute to Plasma Levels of LDL Cholesterol in the General Population

    DEFF Research Database (Denmark)

    Benn, M; Stene, MC; Nordestgaard, BG;

    2008-01-01

    CONTEXT: We have previously shown that rare mutations in the apolipoprotein B gene (APOB) may result in not only severe hypercholesterolemia and ischemic heart disease but also hypocholesterolemia. Despite this, common single-nucleotide polymorphisms (SNPs) in APOB have not convincingly been...... on cholesterol and apolipoprotein B levels. However, as predicted from the magnitude of the observed LDL cholesterol effects, none of these SNPs predicted risk of ischemic heart disease prospectively in the general population, in a case-control study, or as haplotypes. CONCLUSIONS: Multiple common and rare...... demonstrated to affect low-density lipoprotein (LDL) cholesterol levels. OBJECTIVE: We tested the hypothesis that nonsynonymous SNPs in three important functional domains of APOB and APOB tag SNPs predict levels of LDL cholesterol and apolipoprotein B and risk of ischemic heart disease. DESIGN...

  15. NMR derived model of GTPase effector domain (GED self association: relevance to dynamin assembly.

    Directory of Open Access Journals (Sweden)

    Swagata Chakraborty

    Full Text Available Self-association of dynamin to form spiral structures around lipidic vesicles during endocytosis is largely mediated by its 'coiled coil' GTPase Effector Domain (GED, which, in vitro, self-associates into huge helical assemblies. Residue-level structural characterizations of these assemblies and understanding the process of association have remained a challenge. It is also impossible to get folded monomers in the solution phase. In this context, we have developed here a strategy to probe the self-association of GED by first dissociating the assembly using Dimethyl Sulfoxide (DMSO and then systematically monitoring the refolding into helix and concomitant re-association using NMR spectroscopy, as DMSO concentration is progressively reduced. The short segment, Arg109 - Met116, acts as the nucleation site for helix formation and self-association. Hydrophobic and complementary charge interactions on the surfaces drive self-association, as the helices elongate in both the directions resulting in an antiparallel stack. A small N-terminal segment remains floppy in the assembly. Following these and other published results on inter-domain interactions, we have proposed a plausible mode of dynamin self assembly.

  16. Bacteriophage-derived CHAP domain protein, P128, kills Staphylococcus cells by cleaving interpeptide cross-bridge of peptidoglycan.

    Science.gov (United States)

    Sundarrajan, Sudarson; Raghupatil, Junjappa; Vipra, Aradhana; Narasimhaswamy, Nagalakshmi; Saravanan, Sanjeev; Appaiah, Chemira; Poonacha, Nethravathi; Desai, Srividya; Nair, Sandhya; Bhatt, Rajagopala Narayana; Roy, Panchali; Chikkamadaiah, Ravisha; Durgaiah, Murali; Sriram, Bharathi; Padmanabhan, Sriram; Sharma, Umender

    2014-10-01

    P128 is an anti-staphylococcal protein consisting of the Staphylococcus aureus phage-K-derived tail-associated muralytic enzyme (TAME) catalytic domain (Lys16) fused with the cell-wall-binding SH3b domain of lysostaphin. In order to understand the mechanism of action and emergence of resistance to P128, we isolated mutants of Staphylococcus spp., including meticillin-resistant Staphylococcus aureus (MRSA), resistant to P128. In addition to P128, the mutants also showed resistance to Lys16, the catalytic domain of P128. The mutants showed loss of fitness as shown by reduced rate of growth in vitro. One of the mutants tested was found to show reduced virulence in animal models of S. aureus septicaemia suggesting loss of fitness in vivo as well. Analysis of the antibiotic sensitivity pattern showed that the mutants derived from MRSA strains had become sensitive to meticillin and other β-lactams. Interestingly, the mutant cells were resistant to the lytic action of phage K, although the phage was able to adsorb to these cells. Sequencing of the femA gene of three P128-resistant mutants showed either a truncation or deletion in femA, suggesting that improper cross-bridge formation in S. aureus could be causing resistance to P128. Using glutathione S-transferase (GST) fusion peptides as substrates it was found that both P128 and Lys16 were capable of cleaving a pentaglycine sequence, suggesting that P128 might be killing S. aureus by cleaving the pentaglycine cross-bridge of peptidoglycan. Moreover, peptides corresponding to the reported cross-bridge of Staphylococcus haemolyticus (GGSGG, AGSGG), which were not cleaved by lysostaphin, were cleaved efficiently by P128. This was also reflected in high sensitivity of S. haemolyticus to P128. This showed that in spite of sharing a common mechanism of action with lysostaphin, P128 has unique properties, which allow it to act on certain lysostaphin-resistant Staphylococcus strains.

  17. A potential peptide therapeutic derived from the juxtamembrane domain of the epidermal growth factor receptor.

    Directory of Open Access Journals (Sweden)

    Aislyn D W Boran

    Full Text Available The epidermal growth factor receptor (EGFR is involved in many cancers and EGFR has been heavily pursued as a drug target. Drugs targeting EGFR have shown promising clinical results for several cancer types. However, resistance to EGFR inhibitors often occurs, such as with KRAS mutant cancers, therefore new methods of targeting EGFR are needed. The juxtamembrane (JXM domain of EGFR is critical for receptor activation and targeting this region could potentially be a new method of inhibiting EGFR. We hypothesized that the structural role of the JXM region could be mimicked by peptides encoding a JXM amino acid sequence, which could interfere with EGFR signaling and consequently could have anti-cancer activity. A peptide encoding EGFR 645-662 conjugated to the Tat sequence (TE-64562 displayed anti-cancer activity in multiple human cancer cell types with diminished activity in non-EGFR expressing cells and non-cancerous cells. In nude mice, TE-64562 delayed MDA-MB-231 tumor growth and prolonged survival, without inducing toxicity. TE-64562 induced non-apoptotic cell death after several hours and caspase-3-mediated apoptotic cell death with longer treatment. Mechanistically, TE-64562 bound to EGFR, inhibited its dimerization and caused its down-regulation. TE-64562 reduced phosphorylated and total EGFR levels but did not inhibit kinase activity and instead prolonged it. Our analysis of patient data from The Cancer Genome Atlas supported the hypothesis that down-regulation of EGFR is a potential therapeutic strategy, since phospho- and total-EGFR levels were strongly correlated in a large majority of patient tumor samples, indicating that lower EGFR levels are associated with lower phospho-EGFR levels and presumably less proliferative signals in breast cancer. Akt and Erk were inhibited by TE-64562 and this inhibition was observed in vivo in tumor tissue upon treatment with TE-64562. These results are the first to indicate that the JXM domain of EGFR

  18. APP intracellular domain derived from amyloidogenic β- and γ-secretase cleavage regulates neprilysin expression.

    Science.gov (United States)

    Grimm, Marcus O W; Mett, Janine; Stahlmann, Christoph P; Grösgen, Sven; Haupenthal, Viola J; Blümel, Tamara; Hundsdörfer, Benjamin; Zimmer, Valerie C; Mylonas, Nadine T; Tanila, Heikki; Müller, Ulrike; Grimm, Heike S; Hartmann, Tobias

    2015-01-01

    Alzheimer's disease (AD) is characterized by an accumulation of Amyloid-β (Aβ), released by sequential proteolytic processing of the amyloid precursor protein (APP) by β - and γ-secretase. Aβ peptides can aggregate, leading to toxic Aβ oligomers and amyloid plaque formation. Aβ accumulation is not only dependent on de novo synthesis but also on Aβ degradation. Neprilysin (NEP) is one of the major enzymes involved in Aβ degradation. Here we investigate the molecular mechanism of NEP regulation, which is up to now controversially discussed to be affected by APP processing itself. We found that NEP expression is highly dependent on the APP intracellular domain (AICD), released by APP processing. Mouse embryonic fibroblasts devoid of APP processing, either by the lack of the catalytically active subunit of the γ-secretase complex [presenilin (PS) 1/2] or by the lack of APP and the APP-like protein 2 (APLP2), showed a decreased NEP expression, activity and protein level. Similar results were obtained by utilizing cells lacking a functional AICD domain (APPΔCT15) or expressing mutations in the genes encoding for PS1. AICD supplementation or retransfection with an AICD encoding plasmid could rescue the down-regulation of NEP further strengthening the link between AICD and transcriptional NEP regulation, in which Fe65 acts as an important adaptor protein. Especially AICD generated by the amyloidogenic pathway seems to be more involved in the regulation of NEP expression. In line, analysis of NEP gene expression in vivo in six transgenic AD mouse models (APP and APLP2 single knock-outs, APP/APLP2 double knock-out, APP-swedish, APP-swedish/PS1Δexon9, and APPΔCT15) confirmed the results obtained in cell culture. In summary, in the present study we clearly demonstrate an AICD-dependent regulation of the Aβ-degrading enzyme NEP in vitro and in vivo and elucidate the underlying mechanisms that might be beneficial to develop new therapeutic strategies for the

  19. Direct Transcriptional Effects of Apolipoprotein E.

    Science.gov (United States)

    Theendakara, Veena; Peters-Libeu, Clare A; Spilman, Patricia; Poksay, Karen S; Bredesen, Dale E; Rao, Rammohan V

    2016-01-20

    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.

  20. Shark Attack: high affinity binding proteins derived from shark vNAR domains by stepwise in vitro affinity maturation.

    Science.gov (United States)

    Zielonka, Stefan; Weber, Niklas; Becker, Stefan; Doerner, Achim; Christmann, Andreas; Christmann, Christine; Uth, Christina; Fritz, Janine; Schäfer, Elena; Steinmann, Björn; Empting, Martin; Ockelmann, Pia; Lierz, Michael; Kolmar, Harald

    2014-12-10

    A novel method for stepwise in vitro affinity maturation of antigen-specific shark vNAR domains is described that exclusively relies on semi-synthetic repertoires derived from non-immunized sharks. Target-specific molecules were selected from a CDR3-randomized bamboo shark (Chiloscyllium plagiosum) vNAR library using yeast surface display as platform technology. Various antigen-binding vNAR domains were easily isolated by screening against several therapeutically relevant antigens, including the epithelial cell adhesion molecule (EpCAM), the Ephrin type-A receptor 2 (EphA2), and the human serine protease HTRA1. Affinity maturation was demonstrated for EpCAM and HTRA1 by diversifying CDR1 of target-enriched populations which allowed for the rapid selection of nanomolar binders. EpCAM-specific vNAR molecules were produced as soluble proteins and more extensively characterized via thermal shift assays and biolayer interferometry. Essentially, we demonstrate that high-affinity binders can be generated in vitro without largely compromising the desirable high thermostability of the vNAR scaffold.

  1. Downscaling Satellite Precipitation with Emphasis on Extremes: A Variational 1-Norm Regularization in the Derivative Domain

    Science.gov (United States)

    Foufoula-Georgiou, E.; Ebtehaj, A. M.; Zhang, S. Q.; Hou, A. Y.

    2013-01-01

    The increasing availability of precipitation observations from space, e.g., from the Tropical Rainfall Measuring Mission (TRMM) and the forthcoming Global Precipitation Measuring (GPM) Mission, has fueled renewed interest in developing frameworks for downscaling and multi-sensor data fusion that can handle large data sets in computationally efficient ways while optimally reproducing desired properties of the underlying rainfall fields. Of special interest is the reproduction of extreme precipitation intensities and gradients, as these are directly relevant to hazard prediction. In this paper, we present a new formalism for downscaling satellite precipitation observations, which explicitly allows for the preservation of some key geometrical and statistical properties of spatial precipitation. These include sharp intensity gradients (due to high-intensity regions embedded within lower-intensity areas), coherent spatial structures (due to regions of slowly varying rainfall),and thicker-than-Gaussian tails of precipitation gradients and intensities. Specifically, we pose the downscaling problem as a discrete inverse problem and solve it via a regularized variational approach (variational downscaling) where the regularization term is selected to impose the desired smoothness in the solution while allowing for some steep gradients(called 1-norm or total variation regularization). We demonstrate the duality between this geometrically inspired solution and its Bayesian statistical interpretation, which is equivalent to assuming a Laplace prior distribution for the precipitation intensities in the derivative (wavelet) space. When the observation operator is not known, we discuss the effect of its misspecification and explore a previously proposed dictionary-based sparse inverse downscaling methodology to indirectly learn the observation operator from a database of coincidental high- and low-resolution observations. The proposed method and ideas are illustrated in case

  2. BRAF(V600E) Kinase Domain Duplication Identified in Therapy-Refractory Melanoma Patient-Derived Xenografts.

    Science.gov (United States)

    Kemper, Kristel; Krijgsman, Oscar; Kong, Xiangjun; Cornelissen-Steijger, Paulien; Shahrabi, Aida; Weeber, Fleur; van der Velden, Daphne L; Bleijerveld, Onno B; Kuilman, Thomas; Kluin, Roel J C; Sun, Chong; Voest, Emile E; Ju, Young Seok; Schumacher, Ton N M; Altelaar, A F Maarten; McDermott, Ultan; Adams, David J; Blank, Christian U; Haanen, John B; Peeper, Daniel S

    2016-06-28

    The therapeutic landscape of melanoma is improving rapidly. Targeted inhibitors show promising results, but drug resistance often limits durable clinical responses. There is a need for in vivo systems that allow for mechanistic drug resistance studies and (combinatorial) treatment optimization. Therefore, we established a large collection of patient-derived xenografts (PDXs), derived from BRAF(V600E), NRAS(Q61), or BRAF(WT)/NRAS(WT) melanoma metastases prior to treatment with BRAF inhibitor and after resistance had occurred. Taking advantage of PDXs as a limitless source, we screened tumor lysates for resistance mechanisms. We identified a BRAF(V600E) protein harboring a kinase domain duplication (BRAF(V600E/DK)) in ∼10% of the cases, both in PDXs and in an independent patient cohort. While BRAF(V600E/DK) depletion restored sensitivity to BRAF inhibition, a pan-RAF dimerization inhibitor effectively eliminated BRAF(V600E/DK)-expressing cells. These results illustrate the utility of this PDX platform and warrant clinical validation of BRAF dimerization inhibitors for this group of melanoma patients.

  3. Regionalization of local geomorphometric derivations for geological mapping in the sedimentary domain of central Amazônia

    Science.gov (United States)

    Valeriano, Márcio de Morisson; Rossetti, Dilce de Fátima

    2017-03-01

    This paper reports procedures to prepare locally derived geomorphometric data for geological mapping at regional scale in central Amazônia. The size of the study area, approximately 1.5 million km2, and the prevailing flat topography of the targeted environment were the constraints motivating the aims, at spatial and numerical synthesis of the detailed geomorphometric information derived from SRTM DEM. The developed approach consisted in assigning single (average) values to terrain patches, to represent the regional distribution of pixel-based geomorphometric information (slope, profile curvature and relative relief). In analogy to the nature of sedimentary packs, patches were established as contiguous elevation strata, constructed through a procedure combining segmentation, filterings and range compressions. For slope only, pre-processing of locally derived data with median filtering effectively avoided the typical flattening of the regionalized results due to input distribution characteristics. Profile curvature was transformed into absolute values and thus a different meaning from the original (pixel) variable was considered in the interpretation, also avoiding the compensation of original values (positive and negative) tending to zero value when averaged through a regionally flat extension. Examinations near major river valleys showed patched elevation to depict alluvial terraces. In the interfluves and floodplains, contrasting patterns in the averaged variables among patches of similar elevations allowed the recognition of important relief features. In addition to the reduction of the distribution ranges, the correlation between regionalized geomorphometric variables was higher than observed in the originally local data, due to the thematic synthesis following regionalization. Depth of dissection, claimed to be related to the relative age of sedimentary units, was the main factor to explain the overall variations of the geomorphometric results. The developed

  4. Mapping Nanoscale Domains in a Sol-Gel-Derived (Pb, La) (Zr, Ti)O3 Thin Film Using Atomic Force Microscopy

    Institute of Scientific and Technical Information of China (English)

    巴龙; 舒剑; 孙平; 陆祖宏

    2003-01-01

    Local polarization of a sol-gel-derived (Pb,La)(Zr, Ti)O3 thin film is studied from its piezoelectric response measured by using atomic force microscopy. Topographic and piezoelectric images show that the domain sizes of spontaneous polarization and grain sizes are both within the range of tens to hundreds of nanometres. Nanosized domain arrays have been written in an unpoled region to realize data storage by applying pulse voltage. The results show that the domain sizes grow exponentially when the pulse duration increases.

  5. Apolipoprotein CI knock-out mice display impaired memory functions

    NARCIS (Netherlands)

    Berbée, J.F.P.; Abildayeva, K.; Blokland, A.; Jansen, P.J.; Lütjohann, D.; Gautier, T.; Sijbrands, E.; Prickaerts, J.; Hadfoune, M.; Ramaekers, F.C.S.; Kuipers, F.; Rensen, P.C.N.

    2011-01-01

    The e4 allele of apolipoprotein E (APOE4), which is a well established genetic risk factor for development of Alzheimer's disease (AD), is in genetic disequilibrium with the H2 allele of apolipoprotein C1 (APOC1), giving rise to increased expression of apoC-I. This raises the possibility that the H2

  6. Apolipoprotein CI Knock-Out Mice Display Impaired Memory Functions

    NARCIS (Netherlands)

    Berbee, Jimmy F. P.; Vanmierlo, Tim; Abildayeva, Karlygash; Blokland, Arjan; Jansen, Paula J.; Luetjohann, Dieter; Gautier, Thomas; Sijbrands, Eric; Prickaerts, Jos; Hadfoune, M'hamed; Ramaekers, Frans C. S.; Kuipers, Folkert; Rensen, Patrick C. N.; Mulder, Monique

    2011-01-01

    The epsilon 4 allele of apolipoprotein E (APOE4), which is a well established genetic risk factor for development of Alzheimer's disease (AD), is in genetic disequilibrium with the H2 allele of apolipoprotein C1 (APOC1), giving rise to increased expression of apoC-I. This raises the possibility that

  7. Cloning and characterization of an apolipoprotein C2 promoter in the mouse central nervous system

    Institute of Scientific and Technical Information of China (English)

    Zhaoyang Li; Bing Du; Shengyang Li; Xiangchuan Lv; Shenglai Zhou; Yang Yu; Wei Wang; Zhihong Zheng

    2013-01-01

    Apolipoprotein C2 is an important member of the apolipoprotein C family, and is a potent activator of lipoprotein lipase. In the central nervous system, apolipoprotein C2 plays an important role in the catabolism of triglyceride-rich lipoproteins. Studies into the exact regulatory mechanism of mouse apolipoprotein C2 expression have not been reported. In this study, seven luciferase expression vectors, which contained potential mouse apolipoprotein C2 gene promoters, were constructed and co-transfected with pRL-TK into HEK293T cells to investigate apolipoprotein C2 promoter activity. Luciferase assays indicated that the apolipoprotein C2 promoter region was mainly located in the +104 bp to +470 bp region. The activity of the different lengths of apolipoprotein C2 promoter region varied. This staggered negative-positive-negative arrangement indicates the complex regulation of apolipoprotein C2 expression and provides important clues for elucidating the regulatory mechanism of apolipoprotein C2 gene transcription.

  8. Insights into Protein Sequence and Structure-Derived Features Mediating 3D Domain Swapping Mechanism using Support Vector Machine Based Approach

    Directory of Open Access Journals (Sweden)

    Khader Shameer

    2010-06-01

    Full Text Available 3-dimensional domain swapping is a mechanism where two or more protein molecules form higher order oligomers by exchanging identical or similar subunits. Recently, this phenomenon has received much attention in the context of prions and neuro-degenerative diseases, due to its role in the functional regulation, formation of higher oligomers, protein misfolding, aggregation etc. While 3-dimensional domain swap mechanism can be detected from three-dimensional structures, it remains a formidable challenge to derive common sequence or structural patterns from proteins involved in swapping. We have developed a SVM-based classifier to predict domain swapping events using a set of features derived from sequence and structural data. The SVM classifier was trained on features derived from 150 proteins reported to be involved in 3D domain swapping and 150 proteins not known to be involved in swapped conformation or related to proteins involved in swapping phenomenon. The testing was performed using 63 proteins from the positive dataset and 63 proteins from the negative dataset. We obtained 76.33% accuracy from training and 73.81% accuracy from testing. Due to high diversity in the sequence, structure and functions of proteins involved in domain swapping, availability of such an algorithm to predict swapping events from sequence and structure-derived features will be an initial step towards identification of more putative proteins that may be involved in swapping or proteins involved in deposition disease. Further, the top features emerging in our feature selection method may be analysed further to understand their roles in the mechanism of domain swapping.

  9. Apolipoprotein E gene polymorphisms as risk factors for carotid atherosclerosis

    Directory of Open Access Journals (Sweden)

    Zurnić Irena

    2014-01-01

    Full Text Available Background/Aim. Atherosclerosis is still the leading cause of death in Western world. Development of atherosclerotic plaque involves accumulation of inflammatory cells, lipids, smooth muscle cells and extracellular matrix proteins in the intima of the vascular wall. Apolipoprotein E participates in the transport of exogenous cholesterol, endogenouly synthesized lipids and triglycerides in the organism. Apolipoprotein E gene has been identified as one of the candidate genes for atherosclerosis. Previous studies in different populations have clearly implicated apolipoprotein E genetic variation (ε polymorphisms as a major modulator of low density lipoprotein cholesterol levels. Data considering apolipoprotein E polymorphisms in relation to carotid atherosclerosis gave results that are not in full compliance. The aim of present study was to investigate the apolipoprotein E polymorphisms in association with carotid plaque presence, apolipoprotein E and lipid serum levels in patients with carotid atherosclerosis from Serbia. Methods. The study group enrolled 495 participants: 285 controls and 210 consecutive patients with carotid atherosclerosis who underwent carotid endarterectomy. Genotyping of apolipoprotein E polymorphisms were done using polymerase chain reaction and restriction fragment length polymorphism methods. Results. Patients had significantly decreased frequency of the ε2 allele compared to controls. Patients who carry at least one ε2 allele had a significantly higher level of serum apolipoprotein E and significantly lower low density lipoprotein cholesterol levels compared to those who do not carry this allele. Conclusion. Our results suggest protective effect of apolipoprotein E ε2 allele on susceptibility for carotid plaque presence as well as low density lipoprotein cholesterol lowering effect in Serbian patients with carotid atherosclerosis. Further research of multiple gene and environmental factors that contribute to the

  10. Plant-derived SAC domain of PAR-4 (Prostate Apoptosis Response 4 exhibits growth inhibitory effects in prostate cancer cells

    Directory of Open Access Journals (Sweden)

    Shayan eSarkar

    2015-10-01

    Full Text Available The gene Par-4 (Prostate Apoptosis Response 4 was originally identified in prostate cancer cells undergoing apoptosis and its product Par-4 showed cancer specific pro-apoptotic activity. Particularly, the SAC domain of Par-4 (SAC-Par-4 selectively kills cancer cells leaving normal cells unaffected. The therapeutic significance of bioactive SAC-Par-4 is enormous in cancer biology; however, its large scale production is still a matter of concern. Here we report the production of SAC-Par-4-GFP fusion protein coupled to translational enhancer sequence (5′ AMV and apoplast signal peptide (aTP in transgenic Nicotiana tabacum cv. Samsun NN plants under the control of a unique recombinant promoter M24. Transgene integration was confirmed by genomic DNA PCR, Southern and Northern blotting, Real-time PCR and Nuclear run-on assays. Results of Western blot analysis and ELISA confirmed expression of recombinant SAC-Par-4-GFP protein and it was as high as 0.15% of total soluble protein. In addition, we found that targeting of plant recombinant SAC-Par-4-GFP to the apoplast and endoplasmic reticulum (ER was essential for the stability of plant recombinant protein in comparison to the bacterial derived SAC-Par-4. Deglycosylation analysis demonstrated that ER-targeted SAC-Par-4-GFP-SEKDEL undergoes O-linked glycosylation unlike apoplast-targeted SAC-Par-4-GFP. Furthermore, various in vitro studies like mammalian cells proliferation assay (MTT, apoptosis induction assays, and NF-κB suppression suggested the cytotoxic and apoptotic properties of plant-derived SAC-Par-4-GFP against multiple prostate cancer cell lines. Additionally, pre-treatment of MAT-LyLu prostate cancer cells with purified SAC-Par-4-GFP significantly delayed the onset of tumor in a syngeneic rat prostate cancer model. Taken altogether, we proclaim that plant made SAC-Par-4 may become a useful alternate therapy for effectively alleviating cancer in the new era.

  11. The signal peptide anchors apolipoprotein M in plasma lipoproteins and prevents rapid clearance of apolipoprotein M from plasma

    DEFF Research Database (Denmark)

    Christoffersen, Christina; Ahnström, Josefin; Axler, Olof

    2008-01-01

    Lipoproteins consist of lipids solubilized by apolipoproteins. The lipid-binding structural motifs of apolipoproteins include amphipathic alpha-helixes and beta-sheets. Plasma apolipoprotein (apo) M lacks an external amphipathic motif but, nevertheless, is exclusively associated with lipoproteins......M(Q22A)-Tg mice (transgenic mice)) and compared them with mice expressing wild-type human apoM (apoM-Tg mice). The substitution of the amino acid glutamine 22 with alanine in apoM(Q22A) results in secretion of human apoM without a signal peptide. The human apoM mRNA level in liver and the amount...

  12. Apolipoprotein M - a new biomarker in sepsis

    DEFF Research Database (Denmark)

    Christoffersen, Christina; Nielsen, Lars Bo

    2012-01-01

    Care Kumaraswamy and colleagues have investigated whether plasma apolipoprotein M (apoM) is affected during different grades of sepsis, septic shock and systemic inflammatory response syndrome. Interestingly, plasma apoM was significantly decreased in all groups of patients with a relationship...... to severity of disease. This identifies apoM as a potential new biomarker in sepsis. It also underscores the possibility that altered high-density lipoprotein in sepsis patients can affect the course of disease. Thus, since apoM is the carrier of Sphingosine-1-P (S1P), a molecule with great influence...... on vascular barrier function, the study presented raises the interest and relevance for further studies of apoM and S1P in relation to sepsis and inflammation....

  13. The common polymorphism of apolipoprotein E

    DEFF Research Database (Denmark)

    Gerdes, Ulrik

    2003-01-01

    Apolipoprotein E (apoE) has important functions in systemic and local lipid transport, but also has other functions. The gene (APOE) shows a common polymorphism with three alleles--APOE*2, APOE*3, and APOE*4. Their frequencies vary substantially around the world, but APOE*3 is the most common alm...... is associated with varying risk of cardiovascular disease and Alzheimer's disease, but other interesting aspects may emerge in the future....... from only 10-15% in southern Europe to 40-50% in the north. The gradient may be a trace of the demic expansion of agriculture that began about 10,000 years ago, but it may also reflect the possibility that APOE*4 carriers are less likely to develop vitamin D deficiency. The common APOE polymorphism...

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

    Energy Technology Data Exchange (ETDEWEB)

    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 Apo

  15. The effects of ginger on fasting blood sugar, hemoglobin a1c, apolipoprotein B, apolipoprotein a-I and malondialdehyde in type 2 diabetic patients.

    Science.gov (United States)

    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 (pginger 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.

  16. Apolipoprotein M promotes mobilization of cellular cholesterol in vivo

    DEFF Research Database (Denmark)

    Elsøe, Sara; Christoffersen, Christina; Luchoomun, Jayraz

    2013-01-01

    The HDL associated apolipoprotein M (apoM) protects against experimental atherosclerosis but the mechanism is unknown. ApoM increases prebeta-HDL formation. We explored whether plasma apoM affects mobilization of cholesterol from peripheral cells in mice.......The HDL associated apolipoprotein M (apoM) protects against experimental atherosclerosis but the mechanism is unknown. ApoM increases prebeta-HDL formation. We explored whether plasma apoM affects mobilization of cholesterol from peripheral cells in mice....

  17. Site-Specific Photolabeling of the IgG Fab Fragment Using a Small Protein G Derived Domain.

    Science.gov (United States)

    Kanje, Sara; von Witting, Emma; Chiang, Samuel C C; Bryceson, Yenan T; Hober, Sophia

    2016-09-21

    Antibodies are widely used reagents for recognition in both clinic and research laboratories all over the world. For many applications, antibodies are labeled through conjugation to different reporter molecules or therapeutic agents. Traditionally, antibodies are covalently conjugated to reporter molecules via primary amines on lysines or thiols on cysteines. While efficient, such labeling is variable and nonstoichiometric and may affect an antibody's binding to its target. Moreover, an emerging field for therapeutics is antibody-drug conjugates, where a toxin or drug is conjugated to an antibody in order to increase or incorporate a therapeutic effect. It has been shown that homogeneity and controlled conjugation are crucial in these therapeutic applications. Here we present two novel protein domains developed from an IgG-binding domain of Streptococcal Protein G. These domains show obligate Fab binding and can be used for site-specific and covalent attachment exclusively to the constant part of the Fab fragment of an antibody. The two different domains can covalently label IgG of mouse and human descent. The labeled antibodies were shown to be functional in both an ELISA and in an NK-cell antibody-dependent cellular cytotoxicity assay. These engineered protein domains provide novel tools for controlled labeling of Fab fragments and full-length IgG.

  18. DMPD: Regulation of endogenous apolipoprotein E secretion by macrophages. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18388328 Regulation of endogenous apolipoprotein E secretion by macrophages. Kockx M, Jessup...328 Title Regulation of endogenous apolipoprotein E secretion by macrophages. Authors Kockx M, Jessup

  19. Cloning and characterization of a novel apolipoprotein gene, apolipoprotein AV, in tree shrews.

    Science.gov (United States)

    Li, Guoping; Luo, Huairong; Sun, Guotao; Wu, Guisheng; Wu, Gang; Wang, Yan; Man, Yong; Wang, Shu; Li, Jian; Chen, Baosheng

    2013-09-01

    Apolipoprotein AV (apoAV) modulates plasma triglyceride levels, which is an independent risk factor for cardiovascular disease. ApoAV is also involved in atherosclerosis lesion formation. In order to systematically evaluate the apolipoprotein-related gene profile in tree shrew, a model for its insusceptibility to atherosclerosis, we performed apoAV cloning and characterization. The full-length cDNA of apoAV was identified using SMART-RACE. ApoAV cDNA sequence revealed two transcripts, 1,948 and 1,397 base pairs, due to alternative polyadenylation. These two transcripts share the same open reading frame (ORF), which encodes a 369-amino acid protein with high identity to human apoAV (75 %), including a 23-amino acid N-terminal signal peptide. ApoAV is expressed exclusively in the liver. Mature apoAV was expressed in E. coli BL21(DE3) and purified by Ni-chelated resin. Lipoprotein lipase activity was significantly stimulated by this recombinant protein. The full-length ORF of apoAV was cloned into pDsRed-monomer-N1 vector with a red fluorescent protein tag and was primarily localized in cytoplasm of hepG2 cells. The successful cloning, expression and localization of apoAV in tree shrew has laid down the foundation for further investigation on its structure and functions.

  20. Apolipoprotein E: Risk factor for Alzheimer disease

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, M.S.; Thibodeau, S.N.; Tangalos, E.G.; Petersen, R.C.; Kokmen, E.; Smith, G.E.; Schaid, D.J.; Ivnik, R.J. (Mayo Clinic, Rochester, MN (United States))

    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. Design and synthesis of lipid-coupled inositol 1,2,3,4,5,6-hexakisphosphate derivatives exhibiting high-affinity binding for the HIV-1 MA domain.

    Science.gov (United States)

    Tateishi, Hiroshi; Anraku, Kensaku; Koga, Ryoko; Okamoto, Yoshinari; Fujita, Mikako; Otsuka, Masami

    2014-07-21

    The precursor of Gag protein (Pr55(Gag)) of human immunodeficiency virus, the principal structural component required for virus assembly, is known to bind d-myo-phosphatidylinositol 4,5-bisphosphate (PIP2). The N-terminus of Pr55(Gag), the MA domain, plays a critical role in the binding of Pr55(Gag) to the plasma membrane. Herein, we designed and synthesized myo-phosphatidylinositol 2,3,4,5,6-pentakisphosphate (PIP5) derivatives comprising highly phosphorylated inositol and variously modified diacylglycerol to examine the MA-binding properties. The inositol moiety was synthesized starting with myo-inositol and assembled with a hydrophobic glycerol moiety through a phosphate linkage. The Kd value for MA-binding of the PIP5 derivative 2 (Kd = 0.25 μM) was the lowest (i.e., highest affinity) of all derivatives, i.e., 70-fold lower than the Kd for the PIP2 derivative 1 (Kd = 16.9 μM) and 100-fold lower than the Kd for IP6 (Kd = 25.7 μM), suggesting the possibility that the PIP5 derivative blocks Pr55(Gag) membrane binding by competing with PIP2 in MA-binding.

  2. Immunolocalization of cubilin, megalin, apolipoprotein J, and apolipoprotein A-I in the uterus and oviduct.

    Science.gov (United States)

    Argraves, W Scott; Morales, Carlos R

    2004-12-01

    Spermatozoa maturation and capacitation occurring in the male and female reproductive tracts, respectively, involves the remodeling of the spermatozoa plasma membrane. Apolipoprotein J (apoJ) and apolipoprotein A-I (apoA-I) have been implicated in the process of lipid exchange from the spermatozoa plasma membrane to epithelial cells lining the male reproductive tract. Evidence suggests that this process is mediated by the cooperative action of the endocytic lipoprotein receptors megalin and cubilin, which are expressed at the apical surface of absorptive epithelia in various tissues, including the efferent ducts and epididymis. Here, we investigated the possibility that these receptors and their lipid-binding ligands, apoJ and apoA-I, might function similarly in the female reproductive tract. We show that megalin and cubilin are expressed in the uterine epithelium at all stages of the estrous cycle, maximally during estrous and metestrous stages. In the oviduct, there is pronounced expression of both megalin and cubilin in the nonciliated cells of the proximal oviduct and epithelial cells of the distal oviduct, particularly during estrous and metestrous stages. In both uterine and oviduct epithelial cells, megalin and cubilin were located on the apical regions of the cells, consistent with a distribution at the cell surface and in endosomes. ApoJ and apoA-I were both detected in apical regions of uterine and oviduct epithelial cells. Secretory cells of the uterine glands were found to express apoJ and apoA-I suggesting that the glands are a site of synthesis for both proteins. In summary, our findings indicate that megalin and cubilin function within the female reproductive tract, possibly mediating uterine and oviduct epithelial cell endocytosis of apoJ/apoA-I-lipid complexes and thus playing a role in lipid efflux from the sperm plasma membrane, a major initiator of capacitation.

  3. Frequency-domain inversion using the amplitude of the derivative wavefield with respect to the angular frequency

    KAUST Repository

    Choi, Yun Seok

    2012-01-01

    The instantaneous traveltime based inversion was developed to solve the phase wrapping problem, thus generating long-wavelength structures even for a high single-frequency. However, it required aggressive damping to insure proper convergence. A reason for that is the potential for unstable division in the calculation of the instantaneous traveltime for low damping factors. Thus, we propose an inversion algorithm using the amplitude of the derivative wavefield to avoid the unstable division process. Since the amplitude of the derivative wavefield contains the unwrapped-phase information, its inversion has the potential to provide robust inversion results. On the other hand, the damping term rapidly diminishes the amplitude of the derivative wavefield at far source-receiver offsets. As an alternative, we suggest using the logarithmic amplitude of the derivative wavefield. The gradient of this inversion algorithm is obtained by the back-propagation approach, based on the adjoint-state technique. Numerical examples show that the logarithmic-amplitude approach yields better convergent results than the instantaneous traveltime inversion, whereas the pure-amplitude approach does not show much convergence.

  4. [Investigation of neuroprotective activity of apolipoprotein E peptide mimetic Cog1410 in transgenic lines of Drosophila melanogaster].

    Science.gov (United States)

    Latypova, E M; Timoshenko, S I; Kislik, G A; Vitek, M; Shvartsman, A L; Sarantseva, S V

    2014-01-01

    The neuroprotective activity of apolipoprotein E (apoE) peptide mimetic Cog1410, containing amino acid sequence of the receptor-binding domain apoE, has been investigated in transgenic lines of Drosophila melanogaster expressing human APP and beta-secretase. Expression of two transgenes caused neuropathological processes attributed to Alzheimer's disease: neurodegeneration, cognitive abnormality and amyloid deposits formation in brain. It was shown that Cog 1410 reduces neurodegeneration in brain of transgenic flies and improves cognitive functions (odor recognition). These data suggest that Cog1410 is a potential neuroprotector that can be used in AD treatment.

  5. Inhibition of Wnt/β-catenin signaling by a soluble collagen-derived frizzled domain interacting with Wnt3a and the receptors frizzled 1 and 8.

    Directory of Open Access Journals (Sweden)

    Ismaïl Hendaoui

    Full Text Available The Wnt/β-catenin pathway controls cell proliferation, death and differentiation. Several families of extracellular proteins can antagonize Wnt/β-catenin signaling, including the decoy receptors known as secreted frizzled related proteins (SFRPs, which have a cysteine-rich domain (CRD structurally similar to the extracellular Wnt-binding domain of the frizzled receptors. SFRPs inhibit Wnt signaling by sequestering Wnts through the CRD or by forming inactive complexes with the frizzled receptors. Other endogenous molecules carrying frizzled CRDs inhibit Wnt signaling, such as V3Nter, which is proteolytically derived from the cell surface component collagen XVIII and contains a biologically active frizzled domain (FZC18 inhibiting in vivo cell proliferation and tumor growth in mice. We recently showed that FZC18 expressing cells deliver short-range signals to neighboring cells, decreasing their proliferation in vitro and in vivo through the Wnt/β-catenin signaling pathway. Here, using low concentrations of soluble FZC18 and Wnt3a, we show that they physically interact in a cell-free system. In addition, soluble FZC18 binds the frizzled 1 and 8 receptors' CRDs, reducing cell sensitivity to Wnt3a. Conversely, inhibition of Wnt/β-catenin signaling was partially rescued by the expression of full-length frizzled 1 and 8 receptors, but enhanced by the expression of a chimeric cell-membrane-tethered frizzled 8 CRD. Moreover, soluble, partially purified recombinant FZC18_CRD inhibited Wnt3a-induced β-catenin activation. Taken together, the data indicate that collagen XVIII-derived frizzled CRD shifts Wnt sensitivity of normal cells to a lower pitch and controls their growth.

  6. Plasma apolipoprotein A5 and triglycerides in type 2 diabetes

    NARCIS (Netherlands)

    Dallinga-Thie, GM; Van Tol, A; Hattori, H; van Vark-van de Zee, LC; Jansen, H; Sijbrands, EJG

    2006-01-01

    Aims/hypothesis: Variation in the human apolipoprotein (APO) A5 gene (APOA5) is associated with elevated plasma triglycerides. However, data on the exact role of plasma concentrations of APOA5 in human triglyceride homeostasis are lacking. In the present study, we estimated plasma APOA5 levels in pa

  7. Role of apolipoprotein CI in lipid metabolism and bacterial sepsis

    NARCIS (Netherlands)

    Berbée, Jimmy Fransiscus Paulus

    2007-01-01

    The research described in this thesis focussed on the role of apolipoproteins in lipid metabolism, inflammation and bacterial sepsis, with specific emphasis on apoCI. From studies in human APOC1¬-transgenic and apoc1-/- mice, we were able to identify apoCI as a potent inhibitor of triglyceride hydro

  8. Human placenta secretes apolipoprotein B-100-containing lipoproteins

    DEFF Research Database (Denmark)

    Munk-Madsen, Eva; Lindegaard, Marie Louise Skakkebæk; Andersen, Claus B

    2004-01-01

    Supply of lipids from the mother is essential for fetal growth and development. In mice, disruption of yolk sac cell secretion of apolipoprotein (apo) B-containing lipoproteins results in embryonic lethality. In humans, the yolk sac is vestigial. Nutritional functions are instead established very...... of lipid transfer from the mother to the developing fetus....

  9. Apolipoprotein E genotype, cardiovascular biomarkers and risk of stroke

    DEFF Research Database (Denmark)

    Khan, Tauseef A; Shah, Tina; Prieto, David;

    2013-01-01

    At the APOE gene, encoding apolipoprotein E, genotypes of the ε2/ε3/ε4 alleles associated with higher LDL-cholesterol (LDL-C) levels are also associated with higher coronary risk. However, the association of APOE genotype with other cardiovascular biomarkers and risk of ischaemic stroke is less...

  10. Peptides derived from human galectin-3 N-terminal tail interact with its carbohydrate recognition domain in a phosphorylation-dependent manner

    Energy Technology Data Exchange (ETDEWEB)

    Berbís, M. Álvaro [Chemical and Physical Biology Department, Centro de Investigaciones Biológicas, CSIC, 28040 Madrid (Spain); André, Sabine [Institute of Physiological Chemistry, Faculty of Veterinary Medicine, Ludwig-Maximilians University, 80539 Munich (Germany); Cañada, F. Javier [Chemical and Physical Biology Department, Centro de Investigaciones Biológicas, CSIC, 28040 Madrid (Spain); Pipkorn, Rüdiger [Central Peptide Synthesis Unit, German Cancer Research Center, 69120 Heidelberg (Germany); Ippel, Hans [Department of Biochemistry, CARIM, University of Maastricht, Maastricht (Netherlands); Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455 (United States); Mayo, Kevin H. [Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455 (United States); Kübler, Dieter [Biomolecular Interactions, German Cancer Research Center, 69120 Heidelberg (Germany); Gabius, Hans-Joachim [Institute of Physiological Chemistry, Faculty of Veterinary Medicine, Ludwig-Maximilians University, 80539 Munich (Germany); Jiménez-Barbero, Jesús, E-mail: jjbarbero@cib.csic.es [Chemical and Physical Biology Department, Centro de Investigaciones Biológicas, CSIC, 28040 Madrid (Spain)

    2014-01-03

    Highlights: •Galectin-3 is composed of a carbohydrate recognition domain and an N-terminal tail. •Synthetic peptides derived from the tail are shown to interact with the CRD. •This interaction is modulated by Ser- and Tyr-phosphorylation of the peptides. -- Abstract: Galectin-3 (Gal-3) is a multi-functional effector protein that functions in the cytoplasm and the nucleus, as well as extracellularly following non-classical secretion. Structurally, Gal-3 is unique among galectins with its carbohydrate recognition domain (CRD) attached to a rather long N-terminal tail composed mostly of collagen-like repeats (nine in the human protein) and terminating in a short non-collagenous terminal peptide sequence unique in this lectin family and not yet fully explored. Although several Ser and Tyr sites within the N-terminal tail can be phosphorylated, the physiological significance of this post-translational modification remains unclear. Here, we used a series of synthetic (phospho)peptides derived from the tail to assess phosphorylation-mediated interactions with {sup 15}N-labeled Gal-3 CRD. HSQC-derived chemical shift perturbations revealed selective interactions at the backface of the CRD that were attenuated by phosphorylation of Tyr 107 and Tyr 118, while phosphorylation of Ser 6 and Ser 12 was essential. Controls with sequence scrambling underscored inherent specificity. Our studies shed light on how phosphorylation of the N-terminal tail may impact on Gal-3 function and prompt further studies using phosphorylated full-length protein.

  11. Assessment of Satellite-Derived Essential Climate Variables in the Terrestrial Domain: Overview and Status of the CEOS LPV Subgroup

    Science.gov (United States)

    Roman, M. O.

    2015-12-01

    The validation of satellite-derived terrestrial observations has perennially faced the challenge of finding a consistent set of in-situ measurements that can both cover a wide range of surface conditions and provide timely and traceable product accuracy and uncertainty information. The Committee on Earth Observation Satellites (CEOS), the space arm of the Group on Earth Observations (GEO), plays a key role in coordinating the land product validation process. The Land Product Validation (LPV) sub-group of the CEOS Working Group on Calibration and Validation (WGCV) aims to address the challenges associated with the validation of global land products. This paper will provide a status of LPV subgroup focus area activities, which cover seven Global Climate Observing System (GCOS) terrestrial Essential Climate Variables (ECVs): (1) Snow Cover, (2) Surface Albedo, (3) Land Cover, (4) Leaf Area Index, (5) Fraction of Absorbed Photosynthetically Active Radiation (FAPAR), (6) Active Fires, and (7) Soil Moisture; as well as two additional variables (Land Surface Phenology and Land Surface Temperature), which are deemed of high priority of the LPV community. A primary focus of LPV is the implementation of a global validation framework for product intercomparison and validation (fig. 1). This framework is based on a citable protocol, fiducial reference data, and automated subsetting. Ideally, each of these parts will be integrated into an online platform where quantitative tests are run, and standardized intercomparison and validation results reported for all products used in the validation exercise. The establishment of consensus guidelines for in situ measurements as well as inter-comparison of trends derived from independently-obtained reference data and derived products will enhance coordination of the scientific needs of the Earth system communities with global LPV activities (http://lpvs.gsfc.nasa.gov/).

  12. Role of Ets-1 in fibronectin-derived heparin-binding domain polypeptides alleviating melanoma cell invasiveness and chemoresistance.

    Science.gov (United States)

    Tang, Nanhong; Wang, Xiaoqian; Huang, Tao; Wu, Yong; Chen, Yuanzhong

    2014-07-01

    In this study, we observed that rhFNHN29 and rhFNHC36, two recombinant heparin-binding domain polypeptides of fibronectin, suppressed adhesion and invasion of B16F10 and A375 melanoma cells mediated by integrin αv and α2 in a dose-dependent manner. Combined with low-concentration epirubicin (EPI), rhFNHN29 or rhFNHC36 exhibited a synergistic inhibition on the viability and metastasis of B16F10 cells. Moreover, in the presence of high-concentration rhFNHN29 or rhFNHC36, the Ets-1 activity and the expression of p-FAK, p-Erk1/2 and Ets-1 were notably downregulated in B16F10 cells. Ets-1 is one of the central regulatory links for rhFNHN29 and rhFNHC36 to suppress the adhesion and invasion of melanoma cells. Combining rhFNHN29 or rhFNHC36 with EPI may be a good way to alleviate invasiveness or chemoresistance in melanoma.

  13. Binding Activity Difference of Anti-CD20 scFv-Fc Fusion Protein Derived from Variable Domain Exchange

    Institute of Scientific and Technical Information of China (English)

    Shusheng Geng; Beifen Shen; Jiannan Feng; Yan Li; Yingxun Sun; Xin Gu; Ying Huang; Yugang Wang; Xianjiang Kang; Hong Chang

    2006-01-01

    Two novel engineered antibody fragments binding to antigen CD20 were generated by fusing a murine IgM-type anti-CD20 single-chain Fv fragment (scFv) to the human IgG1 CH2 (I.e., Cγ2) and CH3 (I.e., Cγ3) domains with the human IgG1 hinge (I.e. Hγ). Given the relationship between structure and function of protein, the 3-D structures of the two engineered antibody fragments were modeled using computer-aided homology modeling method.Furthermore, the relationship between 3-D conformation and their binding activity was evaluated theoretically.Due to the change of active pocket formed by CDRs, the HL23 (VH-Linker-VL-Hγ-Cγ2-Cγ3) remained its activity because of its preserved conformation, while the binding activity of the LH23 (VL-Linker-VH-Hγ-Cγ2-Cγ3) was impaired severely. Experimental studies by flow cytometry and fluorescence microscopy showed that HL23 possessed significantly superior binding activity to CD20-expressing target cells than LH23. That is to say, the order of variable regions could influence the binding activity of the fusion protein to CD20+ cell lines, which was in accordance with the theoretical results. The study highlights the potential relationship between the antibody binding activity and their 3-D conformation, which appears to be worthwhile in providing direction for future antibody design of recombinant antibody.

  14. Evidence that the amyloid-β protein precursor intracellular domain, AICD, derives from β-secretase-generated C-terminal fragment.

    Science.gov (United States)

    Flammang, Brice; Pardossi-Piquard, Raphaëlle; Sevalle, Jean; Debayle, Delphine; Dabert-Gay, Anne-Sophie; Thévenet, Aurélie; Lauritzen, Inger; Checler, Frédéric

    2012-01-01

    One of the major pathological hallmarks of brains affected with Alzheimer's disease (AD) is the senile plaque, an extracellular deposit mainly composed of a set of highly insoluble peptides of various lengths (39-43 amino acids) referred to as amyloid-β (Aβ) peptides. Aβ peptides are derived from combined proteolytic cleavages undergone on the amyloid-β protein precursor (AβPP) by a set of enzymes called secretases. Several lines of anatomical and biological evidence suggest that Aβ peptides would not account for all pathological stigmata and molecular dysfunctions taking place in AD. In amyloidogenic and non-amyloidogenic pathways, AβPP first undergoes β- or α-secretases-mediated cleavages yielding C99 and C83, respectively. These two membrane-embedded C-terminal fragments are both potential targets of subsequent γ-secretase-mediated proteolysis. The latter cleavage not only generates either p3 or Aβ peptides but similarly gives rise to an AβPP IntraCellular Domain (AICD fragment) that could modulate the transcription of several genes linked to AD pathology. It is therefore striking that AICD theoretically derives from both amyloidogenic and non-amyloidogenic AβPP processing pathways. Here we show that AICD predominantly derives from C99 by means of recombinant substrates and transiently transfected cells expressing C99. Our data suggest a preferred pathogenic pathway for AICD production and suggests that this fragment, in addition to C99 and Aβ peptides, could contribute to AD pathology.

  15. Turkish Heart Study: lipids, lipoproteins, and apolipoproteins.

    Science.gov (United States)

    Mahley, R W; Palaoğlu, K E; Atak, Z; Dawson-Pepin, J; Langlois, A M; Cheung, V; Onat, H; Fulks, P; Mahley, L L; Vakar, F

    1995-04-01

    We examined the plasma lipids, lipoproteins, and selected apolipoproteins in approximately 9,000 men and women from six different regions of Turkey with markedly different diets, ranging from an Aegean coast diet high in olive oil (plasma cholesteryl ester fatty acids enriched in monounsaturated fatty acids) to an inland Anatolian diet high in meat and dairy products (plasma cholesteryl esters enriched in saturated fatty acids). The rural population consuming an olive oil-rich diet had the lowest plasma cholesterol levels (men, 149 mg/dl; women, 150 mg/dl). The urban populations of Istanbul and Adana had higher plasma cholesterol levels (men, 202 and 184 mg/dl, respectively; women, 181 and 190 mg/dl, respectively). Affluent men had the highest cholesterol levels (207 mg/dl). The low density lipoprotein (LDL) cholesterol levels tended to parallel the total cholesterol levels (highest for Istanbul men at 136 mg/dl and lowest for Aegean coast men and women at approximately 100 mg/dl). Strikingly, the Turkish people were found to have very low levels of high density lipoprotein (HDL) cholesterol (HDL-C) (mean values for all six regions: men, 34-38 mg/dl; women, 37-45 mg/dl) and total cholesterol/HDL-C ratios that were high (mean values for all six regions: men, 4.5-5.5; women, 3.9-5.0). The low HDL-C levels appear to be caused, at least in part, by a genetic factor. Triglyceride levels also tended to be high in Turkish men (approximately 120-150 mg/dl) and women (approximately 90-110 mg/dl). Thus, even though the total plasma cholesterol levels are not excessively elevated in comparison to those in other populations, the presence of low HDL-C or low HDL-C coupled with mildly elevated triglyceride levels may represent a significant risk factor for heart disease in the Turkish population. Affluence and higher education were associated with higher cholesterol levels. Lack of physical activity, smoking, and alcohol consumption also tended to be associated with a

  16. Geophysical and geochemical nature of relaminated arc-derived lower crust underneath oceanic domain in southern Mongolia

    Science.gov (United States)

    Guy, Alexandra; Schulmann, Karel; Janoušek, Vojtech; Štípská, Pavla; Armstrong, Robin; Belousova, Elena; Dolgopolova, Alla; Seltmann, Reimar; Lexa, Ondrej; Jiang, Yingde; Hanžl, Pavel

    2016-04-01

    The Central Asian Orogenic Belt (CAOB) in southern Mongolia consists of E-W trending Neoproterozoic cratons and Silurian-Devonian oceanic tectonic zones. Previous study revealed that the Early Paleozoic accretionary wedge and the oceanic tectonic zone are underlain by a layer giving a homogeneous gravity signal. Forward gravity modelling suggests that this layer is not formed of high-density material typical of lower oceanic crust but is composed of low- to intermediate-density rocks resembling continental crust. The nature of this lower crust is constrained by the whole-rock geochemistry and zircon Hf isotopic signature of abundant Late Carboniferous high-K calc-alkaline and Early Permian A-type granitoids intruding the two Early Paleozoic domains. It is possible to explain the genesis of these granitoids by anatexis of juvenile, metaigneous (tonalitic-gabbroic) rocks of Late Cambrian age, the source of which is presumed to lie in the "Khantaishir" arc (520-495Ma) further north. In order to test this hypothesis, the likely modal composition and density of Khantaishir arc-like protoliths are thermodynamically modelled at granulite- and higher amphibolite-facies conditions. It is shown that the current average density of the lower crust inferred by gravity modelling (2730 ±20kg/m3) matches best metamorphosed leucotonalite to diorite. Based on these results, it is now proposed that Mongolian CAOB has an architecture in which the accretionary wedge and oceanic upper crust is underlain by allochthonous lower crust that originated in a Cambrian arc. A tectonic model explaining relamination of allochthonous felsic to intermediate lower crust beneath mafic upper crust is proposed.

  17. Apolipoprotein-E forms dimers in human frontal cortex and hippocampus

    Directory of Open Access Journals (Sweden)

    Halliday Glenda M

    2010-02-01

    Full Text Available Abstract Background Apolipoprotein-E (apoE plays important roles in neurobiology and the apoE4 isoform increases risk for Alzheimer's disease (AD. ApoE3 and apoE2 are known to form disulphide-linked dimers in plasma and cerebrospinal fluid whereas apoE4 cannot form these dimers as it lacks a cysteine residue. Previous in vitro research indicates dimerisation of apoE3 has a significant impact on its functions related to cholesterol homeostasis and amyloid-beta peptide degradation. The possible occurrence of apoE dimers in cortical tissues has not been examined and was therefore assessed. Human frontal cortex and hippocampus from control and AD post-mortem samples were homogenised and analysed for apoE by western blotting under both reducing and non-reducing conditions. Results In apoE3 homozygous samples, ~12% of apoE was present as a homodimer and ~2% was detected as a 43 kDa heterodimer. The level of dimerisation was not significantly different when control and AD samples were compared. As expected, these dimerised forms of apoE were not detected in apoE4 homozygous samples but were detected in apoE3/4 heterozygotes at a level approximately 60% lower than seen in the apoE3 homozygous samples. Similar apoE3 dimers were also detected in lysates of SK-N-SH neuroblastoma cells and in freshly prepared rabbit brain homogenates. The addition of the thiol trapping agent, iodoacetamide, to block reactive thiols during both human and rabbit brain sample homogenisation and processing did not reduce the amount of apoE homodimer recovered. These data indicate that the apoE dimers we detected in the human brain are not likely to be post-mortem artefacts. Conclusion The identification of disulphide-linked apoE dimers in human cortical and hippocampal tissues represents a distinct structural difference between the apoE3 and apoE4 isoforms that may have functional consequences.

  18. Exploring the activity space of peptides binding to diverse SH3 domains using principal property descriptors derived from amino acid rotamers.

    Science.gov (United States)

    He, Ping; Wu, Wei; Yang, Kang; Jing, Tao; Liao, Ke-Long; Zhang, Wei; Wang, Hai-Dong; Hua, Xing

    2011-01-01

    Although there were intensive works addressed on multivariate extraction of the informative components from numerous physicochemical parameters of amino acids in isolated state, the various conformational behaviors of amino acids in complicated biological context have long been underappreciated in the field of quantitative structure-activity relationship (QSAR). In this work, the amino acid rotamers, which were derived from statistical survey of protein crystal structures, were used to reproduce the conformational variety of amino acid side-chains in real condition. In this procedure, these rotamers were superposed into a nx x ny x nz lattice and an artificial probe was employed to detect four kinds of nonbonding field potentials (i.e., electrostatic, steric, hydrophobic, and hydrogen bonds) at each lattice point using a Gaussian-type potential function; the generated massive data were then subjected to a principal component analysis (PCA) treatment to obtain a set of few, informative amino acid descriptors. We used this set of descriptors, that we named principal property descriptors derived from amino acid rotamers (PDAR), to characterize over 13,000 peptides with known binding affinities to 10 types of SH3 domains. Genetic algorithm/ partial least square regression (GA/PLS) modeling and Monte Carlo cross-validation (MCCV) demonstrated that the correlation between the PDAR descriptors and the binding affinities of peptides are comparable with or even better than previously published models. Furthermore, from the PDAR-based QSAR models we concluded that the core motif of peptides, particularly the electrostatic property, hydrophobicity, and hydrogen bond at residue positions P3, P2, and/or P0, contribute significantly to the hAmph SH3 domain-peptide binding, whereas two ends of the peptides, such as P6, P4, P-4, and P5, only play a secondary role in the binding.

  19. Opposing effects of apolipoprotein m on catabolism of apolipoprotein B-containing lipoproteins and atherosclerosis

    DEFF Research Database (Denmark)

    Christoffersen, Christina; Pedersen, Tanja Xenia; Gordts, Philip L S M;

    2010-01-01

    Rationale: Plasma apolipoprotein (apo)M is mainly associated with high-density lipoprotein (HDL). HDL-bound apoM is antiatherogenic in vitro. However, plasma apoM is not associated with coronary heart disease in humans, perhaps because of a positive correlation with plasma low-density lipoprotein...... (LDL). Objective: We explored putative links between apoM and very-low-density (VLDL)/LDL metabolism and the antiatherogenic potential of apoM in vivo. Methods and Results: Plasma apoM was increased approximately 2.1 and approximately 1.5 fold in mice lacking LDL receptors (Ldlr(-/-)) and expressing...... dysfunctional LDL receptor-related protein 1 (Lrp1(n2/n2)), respectively, but was unaffected in apoE-deficient (ApoE(-/-)) mice. Thus, pathways controlling catabolism of VLDL and LDL affect plasma apoM. Overexpression ( approximately 10-fold) of human apoM increased (50% to 70%) and apoM deficiency decreased...

  20. Apolipoprotein E, especially apolipoprotein E4, increases the oligomerization of amyloid β peptide.

    Science.gov (United States)

    Hashimoto, Tadafumi; Serrano-Pozo, Alberto; Hori, Yukiko; Adams, Kenneth W; Takeda, Shuko; Banerji, Adrian Olaf; Mitani, Akinori; Joyner, Daniel; Thyssen, Diana H; Bacskai, Brian J; Frosch, Matthew P; Spires-Jones, Tara L; Finn, Mary Beth; Holtzman, David M; Hyman, Bradley T

    2012-10-24

    Alzheimer's disease (AD) is the most common progressive neurodegenerative disorder causing dementia. Massive deposition of amyloid β peptide (Aβ) as senile plaques in the brain is the pathological hallmark of AD, but oligomeric, soluble forms of Aβ have been implicated as the synaptotoxic component. The apolipoprotein E ε 4 (apoE ε4) allele is known to be a genetic risk factor for developing AD. However, it is still unknown how apoE impacts the process of Aβ oligomerization. Here, we found that the level of Aβ oligomers in APOE ε4/ε4 AD patient brains is 2.7 times higher than those in APOE ε3/ε3 AD patient brains, matched for total plaque burden, suggesting that apoE4 impacts the metabolism of Aβ oligomers. To test this hypothesis, we examined the effect of apoE on Aβ oligomer formation. Using both synthetic Aβ and a split-luciferase method for monitoring Aβ oligomers, we observed that apoE increased the level of Aβ oligomers in an isoform-dependent manner (E2 apoE4, increases Aβ oligomers in the brain. Higher levels of Aβ oligomers in the brains of APOE ε4/ε4 carriers compared with APOE ε3/ε3 carriers may increase the loss of dendritic spines and accelerate memory impairments, leading to earlier cognitive decline in AD.

  1. Photovoltaic conversion using Zn chlorophyll derivative assembled in hydrophobic domain onto nanocrystalline TiO2 electrode.

    Science.gov (United States)

    Amao, Yutaka; Yamada, Yuriko

    2007-02-15

    Photovoltaic conversion using zinc chlorin-e6 (ZnChl-e6), which is zinc chlorophyll-a derivative, and fatty acid (myristic acid or cholic acid) co-adsorbed nanocrystalline TiO2 layer onto ITO glass (OTE) electrode is developed. The maximum peaks of photocurrent action spectrum of the ZnChl-e6 adsorbed TiO2 layer onto OTE (ZnChl-e6/TiO2) are 400, 660 and 800 nm, respectively. Especially the IPCE value at 800 nm (7.5%) is larger than that of 660 nm (6.9%). This result indicates that ZnChl-e6 molecules is aggregated or formed dimer on a nanocrystalline TiO2 layer onto OTE and the absorption band is shifted to near IR region. The photocurrent action spectrum of ZnChl-e6 and cholic acid adsorbed TiO2 layer onto OTE (ZnChl-e6-Cho/TiO2 is similar to that of the UV-vis absorption spectrum in methanol solution, and IPCE values at 400 and 660 nm (8.1%) increase and the IPCE value at 800 nm (4.1%) decreases, indicating that the aggregation of ZnChl-e6 molecules on the TiO2 is suppressed by cholic acid. By using ZnChl-e6-Cho/TiO2, the short-circuit photocurrent density and open-circuit photovoltage also increase compared with that of ZnChl-e6 adsorbed nanocrystalline TiO2 electrode.

  2. Lipid-free Apolipoprotein A-I Structure: Insights into HDL Formation and Atherosclerosis Development

    Science.gov (United States)

    Mei, Xiaohu; Atkinson, David

    2015-01-01

    Apolipoprotein A-I is the major protein in high-density lipoprotein (HDL) and plays an important role during the process of reverse cholesterol transport (RCT). Knowledge of the high-resolution structure of full-length apoA-I is vital for a molecular understanding of the function of HDL at the various steps of the RCT pathway. Due to the flexible nature of apoA-I and aggregation properties, the structure of full-length lipid-free apoA-I has evaded description for over three decades. Sequence analysis of apoA-I suggested that the amphipathic α-helix is the structural motif of exchangeable apolipoprotein, and NMR, X-ray and MD simulation studies have confirmed this. Different laboratories have used different methods to probe the secondary structure distribution and organization of both the lipid-free and lipid-bound apoA-I structure. Mutation analysis, synthetic peptide models, surface chemistry and crystal structures have converged on the lipid-free apoA-I domain structure and function: the N-terminal domain [1–184] forms a helix bundle while the C-terminal domain [185–243] mostly lacks defined structure and is responsible for initiating lipid-binding, aggregation and is also involved in cholesterol efflux. The first 43 residues of apoA-I are essential to stabilize the lipid-free structure. In addition, the crystal structure of C-terminally truncated apoA-I suggests a monomer-dimer conversation mechanism mediated through helix 5 reorganization and dimerization during the formation of HDL. Based on previous research, we have proposed a structural model for full-length monomeric apoA-I in solution and updated the HDL formation mechanism through three intermediate states. Mapping the known natural mutations on the full-length monomeric apoA-I model provides insight into atherosclerosis development through disruption of the N-terminal helix bundle or deletion of the C-terminal lipid-binding domain. PMID:26048453

  3. The peptide derived from the Ig-like domain of human herpesvirus 8 K1 protein induces death in hematological cancer cells

    Directory of Open Access Journals (Sweden)

    Daniluk Urszula

    2012-08-01

    Full Text Available Abstract Background Although significant progress has been made in the treatment of lymphomas, many lymphomas exhibit resistance to cell death, suggesting a defective Fas signaling, which remains poorly understood. We previously reported that cells expressing the K1 protein of human herpesvirus 8 (HHV-8 resist death through the complex formation of the Ig-like domain of K1 with Fas. Recently, we investigated whether peptides derived from the Ig-like domain of the K1 protein may affect cell death. Methods K1 positive and negative cell lines were incubated with the K1-derived peptides, and cell death (apoptotic and necrotic was assessed by flow cytometry and LDH assay. Activation of caspases was assessed by fluorometric assay and flow cytometry. Fas receptor-independent, peptide-mediated cell killing was tested in the Fas-resistant Daudi cell line and Jurkat cell clones deficient in caspase-8 and FADD functionality. Activation of TNF receptors I and II was blocked by pre-incubation with corresponding blocking antibodies. The effect of the K1 peptide in vivo was tested in a mouse xenograft model. Results We observed that the peptide S20-3 enhanced cell death in K1-positive BJAB cells and HHV-8 positive primary effusion lymphoma (PEL cell lines. Similar effects of this peptide were observed in B-cell lymphoma and T-lymphoblastic leukemia cells without K1 expression but not in normal human peripheral blood mononuclear cells. A single intratumoral injection of the S20-3 peptide decreased the growth of Jurkat xenografts in SCID mice. The mechanism of tumor cell death induced by the S20-3 peptide was associated with activation of caspases, but this activity was only partially inhibited by the pan-caspase inhibitor z-VAD. Furthermore, the K1 peptide also killed Fas-resistant Daudi cells, and this killing effect was inhibited by pre-incubation of cells with antibodies blocking TNFRI. Conclusion Taken together, these findings indicate that the S20

  4. Apolipoprotein E and its role in aging and survival

    OpenAIRE

    Bonomini, Francesca; Filippini, Francesca; Hayek, Tony; Aviram, Michael; Keidar, Shlomo; F.Rodella, Luigi; Coleman, Raymond; Rezzani, Rita

    2010-01-01

    Abstract The study of biological aging has seen spectacular progress in the last decade and markers are increasingly employed for understanding physiological processes that change with age. Recently, it has been demonstrated that apolipoprotein E (apoE) has a major impact on longevity, but its mechanisms are still not fully understood. ApoE-deficient (Eo) mice have proved to be a very popular model for studying spontaneous hypercholesterolemia and the subsequent development of athe...

  5. Domains and domain loss

    DEFF Research Database (Denmark)

    Haberland, Hartmut

    2005-01-01

    The domain concept, originally suggested by Schmidt-Rohr in the 1930’s (as credited in Fishman’s writings in the 1970s), was an attempt to sort out different areas of language use in multilingual societies, which are relevant for language choice. In Fishman’s version, domains were considered...... not described in terms of domains, and recent research e.g. about the multilingual communities in the Danish-German border area seems to confirm this....

  6. Syndrome: A Comparison with Apolipoprotein Concentrations and Lipid Profile

    Directory of Open Access Journals (Sweden)

    Magdalena Krintus

    2012-01-01

    Full Text Available Objective. To investigate whether assessment of C-reactive protein (CRP and apolipoproteins, besides the traditional lipid profile, enhances the assessment process for the risk of acute coronary syndrome (ACS. Methods. The study group consisted of 220 consecutive patients admitted to hospital within the first 6 hours from the onset of chest pain. Patients were diagnosed with unstable angina (, non-ST-elevation myocardial infarction (NSTEMI; , or ST-elevation myocardial infarction (STEMI; . ACS patients were compared with 116 healthy volunteers in a case-control study. The serum was assayed on admission for CRP, apolipoproteins ApoAI and ApoB100, and lipid parameters. Results. The highest concentrations of CRP were found in NSTEMI and STEMI, with a median value four-fold higher in ACS patients than in controls (. Only CRP significantly increased the probability of ACS development (adjusted odds ratio for a 1 mg/L increase 1.90; 95% confidence interval [CI] 1.34–2.89 and explained 90% of the variation for ACS development. Similarly, we demonstrated the highest diagnostic accuracy for CRP among all investigated markers (area under the curve 0.80; 95% CI 0.75–0.85. Conclusions. Our study indicates that CRP superiorly to apolipoproteins and lipid profile facilitates the risk stratification for ACS occurrence.

  7. Major lipids, apolipoproteins, and risk of vascular disease

    DEFF Research Database (Denmark)

    Collaboration, Emerging Risk Factors; Di Angelantonio, Emanuele; Sarwar, Nadeem;

    2009-01-01

    did not fast as in those who did. The HR for CHD was 0.35 (95% CI, 0.30-0.42) with a combination of 80 mg/dL lower non-HDL-C and 15 mg/dL higher HDL-C. For the subset with apolipoproteins or directly measured LDL-C, HRs were 1.50 (95% CI, 1.38-1.62) with the ratio non-HDL-C/HDL-C, 1.49 (95% CI, 1.......39-1.60) with the ratio apo B/apo AI, 1.42 (95% CI, 1.06-1.91) with non-HDL-C, and 1.38 (95% CI, 1.09-1.73) with directly measured LDL-C. Hazard ratios for ischemic stroke were 1.02 (95% CI, 0.94-1.11) with triglyceride, 0.93 (95% CI, 0.84-1.02) with HDL-C, and 1.12 (95% CI, 1.04-1.20) with non-HDL-C. CONCLUSION: Lipid...... unclassified strokes. MAIN OUTCOME MEASURES: Hazard ratios (HRs), adjusted for several conventional factors, were calculated for 1-SD higher values: 0.52 log(e) triglyceride, 15 mg/dL high-density lipoprotein cholesterol (HDL-C), 43 mg/dL non-HDL-C, 29 mg/dL apolipoprotein AI, 29 mg/dL apolipoprotein B, and 33...

  8. NMR-based metabolomics of urine for the atherosclerotic mouse model using apolipoprotein-E deficient mice.

    Science.gov (United States)

    Leo, Gregory C; Darrow, Andrew L

    2009-12-01

    NMR-based metabolomics of mouse urine was used in conjunction with the traditional staining and imaging of aortas for the characterization of disease advancement, that is, plaque formation in untreated and drug-treated apolipoprotein-E (apoE) knockout mice. The metabolomics approach with multivariate analysis was able to differentiate the captopril-treated from the untreated mice in general agreement with the staining results. Principal component analysis showed a pattern shift in both the drug-treated and untreated samples as a function of time that could possibly be explained as the effect of aging. Allantoin, a marker attributed to captopril treatment was elevated in the drug-treated mice. From partial least squares-discriminant analysis, xanthine and ascorbate were elevated in the untreated mice and were possible markers of plaque formation in the apoE knockout mice. Several additional peaks in the spectra characterizing the study endpoint were found but their respective metabolite identities were unknown.

  9. Analytic energy derivatives for the calculation of the first-order molecular properties using the domain-based local pair-natural orbital coupled-cluster theory

    Science.gov (United States)

    Datta, Dipayan; Kossmann, Simone; Neese, Frank

    2016-09-01

    The domain-based local pair-natural orbital coupled-cluster (DLPNO-CC) theory has recently emerged as an efficient and powerful quantum-chemical method for the calculation of energies of molecules comprised of several hundred atoms. It has been demonstrated that the DLPNO-CC approach attains the accuracy of a standard canonical coupled-cluster calculation to about 99.9% of the basis set correlation energy while realizing linear scaling of the computational cost with respect to system size. This is achieved by combining (a) localized occupied orbitals, (b) large virtual orbital correlation domains spanned by the projected atomic orbitals (PAOs), and (c) compaction of the virtual space through a truncated pair natural orbital (PNO) basis. In this paper, we report on the implementation of an analytic scheme for the calculation of the first derivatives of the DLPNO-CC energy for basis set independent perturbations within the singles and doubles approximation (DLPNO-CCSD) for closed-shell molecules. Perturbation-independent one-particle density matrices have been implemented in order to account for the response of the CC wave function to the external perturbation. Orbital-relaxation effects due to external perturbation are not taken into account in the current implementation. We investigate in detail the dependence of the computed first-order electrical properties (e.g., dipole moment) on the three major truncation parameters used in a DLPNO-CC calculation, namely, the natural orbital occupation number cutoff used for the construction of the PNOs, the weak electron-pair cutoff, and the domain size cutoff. No additional truncation parameter has been introduced for property calculation. We present benchmark calculations on dipole moments for a set of 10 molecules consisting of 20-40 atoms. We demonstrate that 98%-99% accuracy relative to the canonical CCSD results can be consistently achieved in these calculations. However, this comes with the price of tightening the

  10. Fluorescence analysis of the lipid binding-induced conformational change of apolipoprotein E4.

    Science.gov (United States)

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

    2012-07-17

    Apolipoprotein (apo) E is thought to undergo conformational changes in the N-terminal helix bundle domain upon lipid binding, modulating its receptor binding activity. In this study, site-specific fluorescence labeling of the N-terminal (S94) and C-terminal (W264 or S290) helices in apoE4 by pyrene maleimide or acrylodan was employed to probe the conformational organization and lipid binding behavior of the N- and C-terminal domains. Guanidine denaturation experiments monitored by acrylodan fluorescence demonstrated the less organized, more solvent-exposed structure of the C-terminal helices compared to the N-terminal helix bundle. Pyrene excimer fluorescence together with gel filtration chromatography indicated that there are extensive intermolecular helix-helix contacts through the C-terminal helices of apoE4. Comparison of increases in pyrene fluorescence upon binding of pyrene-labeled apoE4 to egg phosphatidylcholine small unilamellar vesicles suggests a two-step lipid-binding process; apoE4 initially binds to a lipid surface through the C-terminal helices followed by the slower conformational reorganization of the N-terminal helix bundle domain. Consistent with this, fluorescence resonance energy transfer measurements from Trp residues to acrylodan attached at position 94 demonstrated that upon binding to the lipid surface, opening of the N-terminal helix bundle occurs at the same rate as the increase in pyrene fluorescence of the N-terminal domain. Such a two-step mechanism of lipid binding of apoE4 is likely to apply to mostly phospholipid-covered lipoproteins such as VLDL. However, monitoring pyrene fluorescence upon binding to HDL(3) suggests that not only apoE-lipid interactions but also protein-protein interactions are important for apoE4 binding to HDL(3).

  11. Llama-derived single variable domains (nanobodies) directed against chemokine receptor CXCR7 reduce head and neck cancer cell growth in vivo.

    Science.gov (United States)

    Maussang, David; Mujić-Delić, Azra; Descamps, Francis J; Stortelers, Catelijne; Vanlandschoot, Peter; Stigter-van Walsum, Marijke; Vischer, Henry F; van Roy, Maarten; Vosjan, Maria; Gonzalez-Pajuelo, Maria; van Dongen, Guus A M S; Merchiers, Pascal; van Rompaey, Philippe; Smit, Martine J

    2013-10-11

    The chemokine receptor CXCR7, belonging to the membrane-bound G protein-coupled receptor superfamily, is expressed in several tumor types. Inhibition of CXCR7 with either small molecules or small interference (si)RNA has shown promising therapeutic benefits in several tumor models. With the increased interest and effectiveness of biologicals inhibiting membrane-bound receptors we made use of the "Nanobody platform" to target CXCR7. Previously we showed that Nanobodies, i.e. immunoglobulin single variable domains derived from naturally occurring heavy chain-only camelids antibodies, represent new biological tools to efficiently tackle difficult drug targets such as G protein-coupled receptors. In this study we developed and characterized highly selective and potent Nanobodies against CXCR7. Interestingly, the CXCR7-targeting Nanobodies displayed antagonistic properties in contrast with previously reported CXCR7-targeting agents. Several high affinity CXCR7-specific Nanobodies potently inhibited CXCL12-induced β-arrestin2 recruitment in vitro. A wide variety of tumor biopsies was profiled, showing for the first time high expression of CXCR7 in head and neck cancer. Using a patient-derived CXCR7-expressing head and neck cancer xenograft model in nude mice, tumor growth was inhibited by CXCR7-targeting Nanobody therapy. Mechanistically, CXCR7-targeting Nanobodies did not inhibit cell cycle progression but instead reduced secretion of the angiogenic chemokine CXCL1 from head and neck cancer cells in vitro, thus acting here as inverse agonists, and subsequent angiogenesis in vivo. Hence, with this novel class of CXCR7 inhibitors, we further substantiate the therapeutic relevance of targeting CXCR7 in head and neck cancer.

  12. Truncation Derivatives of the S-Layer Protein of Sporosarcina ureae ATCC 13881 (SslA: Towards Elucidation of the Protein Domain Responsible for Self-Assembly

    Directory of Open Access Journals (Sweden)

    Melinda Varga

    2016-08-01

    Full Text Available The cell surface of Sporosarcina ureae ATCC 13881 is covered by an S-layer (SslA consisting of identical protein subunits that assemble into lattices exhibiting square symmetry. In this work the self-assembly properties of the recombinant SslA were characterised with an emphasis on the identification of protein regions responsible for self-assembly. To this end, recombinant mature SslA (aa 31-1097 and three SslA truncation derivatives (one N-terminal, one C-terminal and one CN-terminal were produced in a heterologous expression system, isolated, purified and their properties analysed by in vitro recrystallisation experiments on a functionalised silicon wafer. As a result, recombinant mature SslA self-assembled into crystalline monolayers with lattices resembling the one of the wild-type SslA. The study identifies the central protein domain consisting of amino acids 341-925 self-sufficient for self-assembly. Neither the first 341 amino acids nor the last 172 amino acids of the protein sequence are required to self-assemble into lattices.

  13. Expression of domains for protein-protein interaction of nucleotide excision repair proteins modifies cancer cell sensitivity to platinum derivatives and genomic stability.

    Science.gov (United States)

    Jordheim, Lars Petter; Cros-Perrial, Emeline; Matera, Eva-Laure; Bouledrak, Karima; Dumontet, Charles

    2014-10-01

    Nucleotide excision repair (NER) is involved in the repair of DNA damage caused by platinum derivatives and has been shown to decrease the cytotoxic activity of these drugs. Because protein-protein interactions are essential for NER activity, we transfected human cancer cell lines (A549 and HCT116) with plasmids coding the amino acid sequences corresponding to the interacting domains between excision repair cross-complementation group 1 (ERCC1) and xeroderma pigmentosum, complementation group A (XPA), as well as ERCC1 and xeroderma pigmentosum, complementation group F (XPF), all NER proteins. Using the 3-(4,5-dimethyl-2 thiazoyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay and annexin V staining, we showed that transfected A549 cells were sensitized 1.2-2.2-fold to carboplatin and that transfected HCT116 cells were sensitized 1.4-5.4-fold to oxaliplatin in vitro. In addition, transfected cells exhibited modified in vivo sensitivity to the same drugs. Finally, in particular cell models of the interaction between ERCC1 and XPF, DNA repair was decreased, as evidenced by increased phosphorylation of the histone 2AX after exposure to mitomycin C, and genomic instability was increased, as determined by comparative genomic hybridization studies. The results indicate that the interacting peptides act as dominant negatives and decrease NER activity through inhibition of protein-protein interactions.

  14. Truncation Derivatives of the S-Layer Protein of Sporosarcina ureae ATCC 13881 (SslA): Towards Elucidation of the Protein Domain Responsible for Self-Assembly.

    Science.gov (United States)

    Varga, Melinda

    2016-08-24

    The cell surface of Sporosarcina ureae ATCC 13881 is covered by an S-layer (SslA) consisting of identical protein subunits that assemble into lattices exhibiting square symmetry. In this work the self-assembly properties of the recombinant SslA were characterised with an emphasis on the identification of protein regions responsible for self-assembly. To this end, recombinant mature SslA (aa 31-1097) and three SslA truncation derivatives (one N-terminal, one C-terminal and one CN-terminal) were produced in a heterologous expression system, isolated, purified and their properties analysed by in vitro recrystallisation experiments on a functionalised silicon wafer. As a result, recombinant mature SslA self-assembled into crystalline monolayers with lattices resembling the one of the wild-type SslA. The study identifies the central protein domain consisting of amino acids 341-925 self-sufficient for self-assembly. Neither the first 341 amino acids nor the last 172 amino acids of the protein sequence are required to self-assemble into lattices.

  15. Common and Rare Alleles in Apolipoprotein B Contribute to Plasma Levels of LDL Cholesterol in the General Population

    DEFF Research Database (Denmark)

    Benn, M; Stene, MC; Nordestgaard, BG;

    2008-01-01

    demonstrated to affect low-density lipoprotein (LDL) cholesterol levels. OBJECTIVE: We tested the hypothesis that nonsynonymous SNPs in three important functional domains of APOB and APOB tag SNPs predict levels of LDL cholesterol and apolipoprotein B and risk of ischemic heart disease. DESIGN......: This was a prospective study with 25 yr 100% follow up, The Copenhagen City Heart Study. SETTING: The study was conducted in the Danish general population. PARTICIPANTS: Participants included 9185 women and men aged 20-80+ yr. MAIN OUTCOME MEASURES: Levels of LDL cholesterol and apolipoprotein B and risk of ischemic......Q (0.09), E4154K (0.17), and N4311S (0.21). SNPs were associated with increases (T71I, Ivs181708g>t, T2488Tc>t, R3611) or decreases (Ivs4+171c>a, A591V, Ivs18+379a>c, P2712L, E4154, N4311S) in LDL cholesterol from -4.7 to +8.2% (-0.28 to 0.30 mmol/liter; P

  16. Influence of apolipoproteins on the association between lipids and insulin sensitivity

    DEFF Research Database (Denmark)

    Baldi, Simona; Bonnet, Fabrice; Laville, Martine;

    2013-01-01

    We evaluated whether the association of insulin sensitivity with HDL cholesterol (HDL) and triglycerides is influenced by major plasma apolipoproteins, as suggested by recent experimental evidence.......We evaluated whether the association of insulin sensitivity with HDL cholesterol (HDL) and triglycerides is influenced by major plasma apolipoproteins, as suggested by recent experimental evidence....

  17. Reduced apolipoprotein glycosylation in patients with the metabolic syndrome.

    Directory of Open Access Journals (Sweden)

    Olga V Savinova

    Full Text Available 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.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.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.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.

  18. Tailor-making a protein a-derived domain for efficient site-specific photocoupling to Fc of mouse IgG₁.

    Directory of Open Access Journals (Sweden)

    Feifan Yu

    Full Text Available Affinity proteins binding to antibody constant regions have proved to be invaluable tools in biotechnology. Here, protein engineering was used to expand the repertoire of available immunoglobulin binding proteins via improvement of the binding strength between the widely used staphylococcal protein A-derived Z domain and the important immunoglobulin isotype mouse IgG₁ (mIgG₁. Addressing seven positions in the 58-residue three-helix bundle Z domain by single or double amino acid substitutions, a total of 170 variants were individually constructed, produced in E. coli and tested for binding to a set of mouse IgG₁ monoclonal antibodies (mAbs. The best variant, denoted Z(F5I corresponding to a Phe to Ile substitution at position 5, showed a typical ten-fold higher affinity than the wild-type as determined by biosensor technology. Eight amino acid positions in the Z(F5I variant were separately mutated to cysteine for incorporation of a photoactivable maleimide-benzophenone (MBP group as a probe for site-specific photoconjugation to Fc of mIgG₁, The best photocoupling efficiency to mIgG₁ Fc was seen when the MBP group was coupled to Cys at position 32, resulting in adduct formation to more than 60% of all heavy chains, with no observable non-selective conjugation to the light chains. A similar coupling yield was obtained for a panel of 19 different mIgG₁ mAbs, indicating a general characteristic. To exemplify functionalization of a mIgG₁ antibody via site-specific biotinylation, the Z(F5I-Q32C-MBP protein was first biotinylated using an amine reactive reagent and subsequently photoconjugated to an anti-human interferon-gamma mIgG₁ mAb. When comparing the specific antigen binding ability of the probe-biotinylated mAb to that of the directly biotinylated mAb, a significantly higher bioactivity was observed for the sample biotinylated using the Z(F5I-Q32C-MBP probe. This result indicates that the use of a site-specific and affinity probe

  19. The Apolipoprotein E Gene, Attention, and Brain Function

    OpenAIRE

    Parasuraman, Raja; Pamela M Greenwood; Sunderland, Trey

    2002-01-01

    The ɛ4 allele of the apolipoprotein E (ApoE) gene is associated with alterations in brain function and is a risk factor for Alzheimer’s disease (AD). Changes in components of visuospatial attention with ApoE-ɛ4, aging, and AD are described. Healthy middle-aged adults without dementia who have the ApoE-ɛ4 gene show deficits in spatial attention and working memory that are qualitatively similar to those seen in clinically diagnosed AD patients. The findings support an association between ApoE p...

  20. The intravenous injection of oxidized LDL- or Apolipoprotein B100 – Coupled splenocytes promotes Th1 polarization in wildtype and Apolipoprotein E – Deficient mice

    Energy Technology Data Exchange (ETDEWEB)

    Steinmetz, Martin, E-mail: martin.steinmetz@ukb.uni-bonn.de [INSERM, Unit 970, Paris Cardiovascular Research Center, 75015 Paris (France); Internal Medicine II, University Hospital Bonn, 53105 Bonn (Germany); Ponnuswamy, Padmapriya; Laurans, Ludivine; Esposito, Bruno; Tedgui, Alain [INSERM, Unit 970, Paris Cardiovascular Research Center, 75015 Paris (France); Mallat, Ziad [INSERM, Unit 970, Paris Cardiovascular Research Center, 75015 Paris (France); Division of Cardiovascular Medicine, University of Cambridge, Addenbrooke' s Hospital, Cambridge, CB2 2QQ (United Kingdom)

    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

  1. Both serum apolipoprotein B and the apolipoprotein B/apolipoprotein A-I ratio are associated with carotid intima-media thickness.

    Directory of Open Access Journals (Sweden)

    Fei Huang

    Full Text Available BACKGROUND: Previous studies indicated that apolipoprotein measurements predicted cardiovascular disease (CVD risk; however, associations between apolipoproteins and carotid intima-media thickness (CIMT were less explored. METHODOLOGY AND PRINCIPAL FINDINGS: The cross-sectional study included 6069 participants aged 40 years or older with NGT from Shanghai, China. Serum fasting traditional lipids (total cholesterol [TC], low-density lipoprotein cholesterol [LDL-C], high-density lipoprotein cholesterol [HDL-C] and triglycerides [TG], apoA-I and apoB were assessed. A high-resolution B-mode ultrasonography was performed to measure CIMT. We found CIMT increased progressively across the quartiles of serum apoB (p for trend <0.0001. In logistic regression, concentrations of apoB (odds ratio [OR] 1.27, 95% confidence interval [CI] 1.18-1.36, TC (OR 1.23, 95% CI 1.14-1.32, LDL-C (OR 1.25, 95% CI 1.16-1.34 and TG (OR 1.11, 95% CI 1.04-1.20 were significantly related to elevated CIMT after adjusted for age and sex. Meanwhile, the apoB/apoA-I ratio (OR 1.25, 95% CI 1.17-1.34 related to elevated CIMT. ApoB (OR 1.23, 95% CI 1.00-1.51 and the apoB/apoA-I ratio (OR 1.19, 95% CI 1.04-1.36 remained significantly associated with elevated CIMT, after adjusted for the traditional CVD risk factors including traditional lipids. CONCLUSIONS AND SIGNIFICANCE: There were significant associations between serum apoB, the apoB/apoA-I ratio and elevated CIMT. Serum apoB and the apoB/apoA-I ratio might be independent predictors of early atherosclerosis in NGT.

  2. Oral-derived bacterial flora defends its domain by recognizing and killing intruders--a molecular analysis using Escherichia coli as a model intestinal bacterium.

    Science.gov (United States)

    He, Xuesong; Tian, Yan; Guo, Lihong; Lux, Renate; Zusman, David R; Shi, Wenyuan

    2010-10-01

    Within the same human gastrointestinal tract, substantial differences in the bacterial species that inhabit oral cavity and intestinal tract have been noted. Previous research primarily attributed the differences to the influences of host environments and nutritional availabilities ("host habitat" effect). Our recent study indicated that, other than the host habitat effect, an existing microbial community could impose a selective pressure on incoming foreign bacterial species independent of host-mediated selection ("community selection" effect). In this study, we employed in vitro microbial floras representing microorganisms that inhabit the oral cavities and intestinal tract of mice in combination with Escherichia coli as a model intestinal bacterium and demonstrated that E. coli displays a striking community preference. It thrived when introduced into the intestinal microbial community and survived poorly in the microbial flora of foreign origin (oral community). A more detailed examination of this phenomenon showed that the oral community produced oxygen-free radicals in the presence of wild-type E. coli while mutants deficient in lipopolysaccharides (LPS) did not trigger significant production of these cell-damaging agents. Furthermore, mutants of E. coli defective in the oxidative stress response experienced a more drastic reduction in viability when cocultivated with the oral flora, while the exogenous addition of the antioxidant vitamin C was able to rescue it. We concluded that the oral-derived microbial community senses the E. coli LPS and kills the bacterium with oxygen-free radicals. This study reveals a new mechanism of community invasion resistance employed by established microflora to defend their domains.

  3. Interaction of 2C T cells with a hybrid Ld molecule bearing an alpha 3 domain derived from the class IB molecule, Qa-2.

    Science.gov (United States)

    Ungchusri, T; Kettman, J R; Forman, J

    1997-07-01

    The CD8 co-receptor interacts with nonpolymorphic residues on class I molecules. LQ3, a laboratory engineered Ld molecule bearing an alpha 3 domain derived from Q7 (Qa-2), interacts poorly with anti-Ld CD8-dependent T cells. 2C TCR transgenic mice bear a receptor specific for the p2Ca peptide bound to Ld. The authors show that although this peptide interacts with LQ3, LQ3 APC fail to activate splenic 2C CD8 T cells in vitro in the absence of IL-2, while control Ld APC do. The authors have used this receptor ligand pair to examine negative selection within the thymus of (B6 x C3H.Ld)F1 versus (B6 x C3H.LQ3)F1 radiation chimeras repopulated with 2C bone marrow cells. While positive selection occurs normally in (B6 x C3H)F1 chimeras, animals expressing either Ld or LQ3 fail to generate 2C CD8+ cells. Thus, either CD8 is not required for negative selection of this TCR or a weak interaction of CD8 with LQ3 is sufficient. TSA-1, a developmentally regulated marker, was used to follow the process of negative selection. The results show that deletion of 2C T cells does not occur until thymocytes reach the double positive (DP) stage. Furthermore, the authors noted a small population of DP TSA-1hi cells remains, while DP TSA-1int and TSA-1lo cells are absent. These data support the notion that thymocytes either reach a particular stage of development or locate in an appropriate intrathymic compartment before they undergo negative selection.

  4. Identification of the peptide derived from S1 domain that inhibits type I and type II feline infectious peritonitis virus infection.

    Science.gov (United States)

    Doki, Tomoyoshi; Takano, Tomomi; Koyama, Yusuke; Hohdatsu, Tsutomu

    2015-06-02

    Feline infectious peritonitis virus (FIPV) can cause a lethal disease in cats, feline infectious peritonitis (FIP). A therapeutic drug that is effective against FIP has not yet been developed. Peptides based on viral protein amino acid sequences have recently been attracting attention as new antiviral drugs. In the present study, we synthesized 30 overlapping peptides based on the amino acid sequence of the S1 domain of the type I FIPV strain KU-2 S protein, and investigated their inhibitory effects on FIPV infection. To evaluate the inhibitory effects on type I FIPV infection of these peptides, we investigated a method to increase the infection efficiency of poorly replicative type I FIPV. The efficiency of type I FIPV infection was increased by diluting the virus with medium containing a polycation. Of the 30 peptides, I-S1-8 (S461-S480), I-S1-9 (S471-S490), I-S1-10 (S481-S500), I-S1-16 (S541-S560), and I-S1-22 (S601-S620) significantly decreased the infectivity of FIPV strain KU-2 while I-S1-9 and I-S1-16 exhibited marked inhibitory effects on FIPV infection. The inhibitory effects on FIPV infection of these 2 peptides on other type I and type II FIPV strains, feline herpesvirus (FHV), and feline calicivirus (FCV) were also examined. These 2 peptides specifically inhibited type I and type II FIPV, but did FHV or FCV infection. In conclusion, the possibility of peptides derived from the S protein of type I FIPV strain KU-2 as anti-FIPV agents effective not only for type I, but also type II FIPV was demonstrated in vitro.

  5. Association of apolipoprotein E (RFLP polymorphism with myopia

    Directory of Open Access Journals (Sweden)

    Himabindu P

    2006-01-01

    Full Text Available BACKGROUND: Myopia or nearsightedness is a spherical error of refraction, whereby the images are focused in front of retina. Eye, being an organ rich in activated oxygen species, requires a high level of antioxidants to protect the unsaturated fatty acids. Apolipoprotein E (APOE is one of the proteins that is produced by Muller cells within the retina and is also endowed with antioxidant properties. Genetic polymorphism of APO E is controlled by three common alleles e3, e2 and e4 and rare e1, e4v at the APOE structural gene locus. Different isoforms of APO E differ in their antioxidant properties, and the e4 allele has lesser ability to combat oxidative stress. AIMS: Myopia being a disease influenced by oxidative stress, the present study was undertaken to find association of myopia with APO E polymorphism. MATERIALS AND METHODS: A total of 187 myopic cases and 192 controls were genotyped for apolipoprotein E polymorphism. RESULTS: In both controls and myopic cases, E3/3 genotype was found to be the most frequent one. There was an increase in E3/4 genotype frequency among male probands, high myopia cases and probands with early age at onset, suggesting that the E3/4 genotype might confer risk for myopia development. CONCLUSION: This association with E3/4 genotype might predispose susceptible individuals to develop high myopia and early onset myopia.

  6. Amphotericin B induced interdigitation of apolipoprotein stabilized nanodisk bilayers

    Energy Technology Data Exchange (ETDEWEB)

    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.

  7. Smooth muscle cells healing atherosclerotic plaque disruptions are of local, not blood, origin in apolipoprotein E knockout mice

    DEFF Research Database (Denmark)

    Bentzon, Jacob F; Sondergaard, Claus S; Kassem, Mustafa;

    2007-01-01

    circulating bone marrow-derived progenitor cells. Here, we analyzed the contribution of this mechanism to plaque healing after spontaneous and mechanical plaque disruption in apolipoprotein E knockout (apoE-/-) mice. METHODS AND RESULTS: To determine the origin of SMCs after spontaneous plaque disruption......, irradiated 18-month-old apoE-/- mice were reconstituted with bone marrow cells from enhanced green fluorescent protein (eGFP) transgenic apoE-/- mice and examined when they died up to 9 months later. Plaque hemorrhage, indicating previous plaque disruption, was widely present, but no bone marrow-derived e......GFP+ SMCs were detected. To examine the origin of healing SMCs in a model that recapitulates more features of human plaque rupture and healing, we developed a mechanical technique that produced consistent plaque disruption, superimposed thrombosis, and SMC-mediated plaque healing in apoE-/- mice. Mechanical...

  8. Site-specific dephosphorylation of tau of apolipoprotein E-deficient and control mice by M1 muscarinic agonist treatment.

    Science.gov (United States)

    Genis, I; Fisher, A; Michaelson, D M

    1999-01-01

    Apolipoprotein E (apoE)-deficient mice have memory deficits that are associated with synaptic loss of basal forebrain cholinergic projections and with hyperphosphorylation of distinct epitopes of the microtubule-associated protein tau. Furthermore, treatment of apoE-deficient mice with the M1 selective agonist 1-methylpiperidine-4-spiro-(2'-methylthiazoline) [AF150(S)] abolishes their memory deficits and results in recovery of their brain cholinergic markers. In the present study, we used a panel of anti-tau monoclonal antibodies to further map the tau epitopes that are hyperphosphorylated in apoE-deficient mice and examined the effects of prolonged treatment with AF150(S). This revealed that tau of apoE-deficient mice contains a distinct, hyperphosphorylated "hot spot" domain which is localized N-terminally to the microtubule binding domain of tau, and that AF150(S) has an epitope-specific tau dephosphorylating effect whose magnitude is affected by apoE deficiency. Accordingly, epitopes which reside in the hyperphosphorylated "hot spot" are dephosphorylated by AF150(S) in apoE-deficient mice but are almost unaffected in the controls, whereas epitopes which flank this tau domain are dephosphorylated by AF150(S) in both mice groups. In contrast, epitopes located at the N and C terminals of tau are unaffected by AF150(S) in both groups of mice. These findings suggest that apoE deficiency results in hyperphosphorylation of a distinct tau domain whose excess phosphorylation can be reduced by muscarinic treatment.

  9. Apolipoprotein E: structure and function in lipid metabolism, neurobiology, and Alzheimer's diseases.

    Science.gov (United States)

    Huang, Yadong; Mahley, Robert W

    2014-12-01

    Apolipoprotein (apo) E is a multifunctional protein with central roles in lipid metabolism, neurobiology, and neurodegenerative diseases. It has three major isoforms (apoE2, apoE3, and apoE4) with different effects on lipid and neuronal homeostasis. A major function of apoE is to mediate the binding of lipoproteins or lipid complexes in the plasma or interstitial fluids to specific cell-surface receptors. These receptors internalize apoE-containing lipoprotein particles; thus, apoE participates in the distribution/redistribution of lipids among various tissues and cells of the body. In addition, intracellular apoE may modulate various cellular processes physiologically or pathophysiologically, including cytoskeletal assembly and stability, mitochondrial integrity and function, and dendritic morphology and function. Elucidation of the functional domains within this protein and of the three-dimensional structure of the major isoforms of apoE has contributed significantly to our understanding of its physiological and pathophysiological roles at a molecular level. It is likely that apoE, with its multiple cellular origins and multiple structural and biophysical properties, is involved widely in processes of lipid metabolism and neurobiology, possibly encompassing a variety of disorders of neuronal repair, remodeling, and degeneration by interacting with different factors through various pathways.

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

    Science.gov (United States)

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

    1998-10-15

    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.

  11. VLDL lipolysis products increase VLDL fluidity and convert apolipoprotein E4 into a more expanded conformation.

    Science.gov (United States)

    Tetali, Sarada D; Budamagunta, Madhu S; Simion, Catalina; den Hartigh, Laura J; Kálai, Tamás; Hideg, Kálmán; Hatters, Danny M; Weisgraber, Karl H; Voss, John C; Rutledge, John C

    2010-06-01

    Our previous work indicated that apolipoprotein (apo) E4 assumes a more expanded conformation in the postprandial period. The postprandial state is characterized by increased VLDL lipolysis. In this article, we tested the hypothesis that VLDL lipolysis products increase VLDL particle fluidity, which mediates expansion of apoE4 on the VLDL particle. Plasma from healthy subjects was collected before and after a moderately high-fat meal and incubated with nitroxyl-spin labeled apoE. ApoE conformation was examined by electron paramagnetic resonance spectroscopy using targeted spin probes on cysteines introduced in the N-terminal (S76C) and C-terminal (A241C) domains. Further, we synthesized a novel nitroxyl spin-labeled cholesterol analog, which gave insight into lipoprotein particle fluidity. Our data revealed that the order of lipoprotein fluidity was HDL approximately LDL

  12. C-terminal interactions of apolipoprotein E4 respond to the postprandial state.

    Science.gov (United States)

    Tetali, Sarada D; Budamagunta, Madhu S; Voss, John C; Rutledge, John C

    2006-07-01

    Increased triglyceride-rich lipoproteins (TGRLs) in the postprandial state are associated with atherosclerosis. We investigated whether the postprandial state induced structural changes at the apolipoprotein E4 (apoE4) C terminus, its principal lipid binding domain, using electron paramagnetic resonance (EPR) spectroscopy of a site-directed spin label attached to the cysteine of apoE4-W264C. Spin coupling between labels located in the C termini was followed after mixing with preprandial and postprandial human plasma samples. Our results indicate that postprandial plasma triggers a reorganization of the protein such that the dipolar broadening is diminished, indicating a reduction in C-terminal interaction. The loss of spectral broadening was directly correlated with an increase in postprandial plasma triglycerides and was reduced with delipidated plasma. The spin-labeled apoE4 displayed a lipid preference of VLDL > LDL > HDL in the preprandial and postprandial states. The apoE4 shift to VLDL during the postprandial state was accompanied by a loss in spectral broadening of the protein. These findings suggest that apoE4 associated with LDL maintains self-association via its C terminus and that this association is diminished in VLDL-associated protein. Lipolyzed TGRL reflected a depletion of the C-terminal interaction of apoE4. Addition of palmitate to VLDL gave a similar response as lipolyzed TGRL, suggesting that lipolysis products play a major role in reorganizing apoE4 during the postprandial state.

  13. Expression of the very low-density lipoprotein receptor (VLDL-r), an apolipoprotein-E receptor, in the central nervous system and in Alzheimer`s disease

    Energy Technology Data Exchange (ETDEWEB)

    Christie, R.H.; Chung, Haeyong; Rebeck, G.W.; Hyman, B.T. [Massachusetts General Hospital, Boston, MA (United States)] [and others

    1996-04-01

    The very low density lipoprotein receptor (VLDL-r) is a cell-surface molecule specialized for the internalization of multiple diverse ligands, including apolipoprotein E (apoE)-containing lipoprotein particles, via clathrin-coated pits. Its structure is similar to the low-density lipoprotein receptor (LDL-r), although the two have substantially different systemic distributions and regulatory pathways. The present work examines the distribution of VLDL-r in the central nervous system (CNS) and in relation to senile plaques in Alzheimer disease (AD). VLDL-r is present on resting and activated microglia, particularly those associated with senile plaques (SPs). VLDL-r immunoreactivity is also found in cortical neurons. Two exons of VLDL-r mRNA are differentially spliced in the mature receptor mRNA. One set of splice forms gives rise to receptors containing (or lacking) an extracellular O-linked glycosylation domain near the transmembrane portion of the molecule. The other set of splice forms appears to be brain-specific, and is responsible for the presence or absence of one of the cysteine-rich repeat regions in the binding region of the molecule. Ratios of the receptor variants generated from these splice forms do not differ substantially across different cortical areas or in AD. We hypothesize that VLDL-r might contribute to metabolism of apoE and apoE/A{beta} complexes in the brain. Further characterization of apoE receptors in Alzheimer brain may help lay the groundwork for understanding the role of apoE in the CNS and in the pathophysiology of AD. 43 refs., 5 figs.

  14. Relationship between depression and apolipoproteins A and B: a case-control study

    Directory of Open Access Journals (Sweden)

    Masoumeh Sadeghi

    2011-01-01

    Full Text Available OBJECTIVE: To investigate the relation between major depressive disorder and metabolic risk factors of coronary heart disease. INTRODUCTION: Little evidence is available indicating a relationship between major depressive disorder and metabolic risk factors of coronary heart disease such as lipoprotein and apolipoprotein. METHODS: This case-control study included 153 patients with major depressive disorder who fulfilled the criteria of the Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV, and 147 healthy individuals. All participants completed a demographic questionnaire and Hamilton rating scale for depression. Anthropometric characteristics were recorded. Blood samples were taken and total cholesterol, high-and low-density lipoproteins and apolipoproteins A and B were measured. To analyze the data, t-test, χ2 test, Pearson correlation test and linear regression were applied. RESULTS: Depression was a negative predictor of apolipoprotein A (β = -0.328, p<0.01 and positive predictor of apolipoprotein B (β = 0.290, p<0.05. Apolipoprotein A was inversely predicted by total cholesterol (β = -0.269, p<0.05 and positively predicted by high-density lipoprotein (β = 0.401, p<0.01. Also, low-density lipoprotein was a predictor of apolipoprotein B (β = 0.340, p<0.01. The severity of depression was correlated with the increment in serum apolipoprotein B levels and the decrement in serum apolipoprotein A level. CONCLUSION: In view of the relationship between apolipoproteins A and B and depression, it would seem that screening of these metabolic risk factors besides psychological interventions is necessary in depressed patients

  15. Apolipoprotein B100 analysis in microchip with electrochemical detection

    Institute of Scientific and Technical Information of China (English)

    Cheng Cheng Liu; Yun Liu; Hui Xiang Wang; Yan Bo Qi; Peng Yuan Yang; Bao Hong Liu

    2011-01-01

    Apolipoprotein B100 (apoB-100) is a major protein of the cholesterol-rich low-density lipoprotein (LDL) and reflects a better assessment of total atherogenic burden to the vascular system than LDL. In this work, a simple and sensitive method has been developed to determine picoliter apoB-100s using the PMMA microfluidic chip coupled with electrochemical detection system. This method performs very well with a detectable linear range of 1-800 pg/mL and a detection limit of 1 pg/mL. A real serum sample has further been detected by this microchip-based biosensor. The results show that this kind of method is practicable and has the potential application in clinical analysis and diagnosis.

  16. The Apolipoprotein E Antagonistic Pleiotropy Hypothesis: Review and Recommendations

    Directory of Open Access Journals (Sweden)

    Elizabeth R. Tuminello

    2011-01-01

    Full Text Available Research on apolipoprotein E (APOE has consistently revealed a relationship between the gene's ε4 allele and risk for development of Alzheimer's disease (AD. However, research with younger populations of ε4 carriers has suggested that the APOE ε4 allele may in fact be beneficial in earlier ages and may only confer risk of cognitive decline later in life. Accordingly, we and others have proposed that APOE may represent an example of antagonistic pleiotropy. Antagonistic pleiotropy is an evolutionary biology concept that proposes certain genes or alleles that may differentially impact fitness during different life stages. We critically review this hypothesis in light of new research of the impact of APOE on cognition and neural integrity across the lifespan. We provide recommendations for the revision of the antagonistic pleiotropy hypothesis of APOE and suggest important avenues for future research in this area.

  17. Function and Comorbidities of Apolipoprotein E in Alzheimer's Disease

    Directory of Open Access Journals (Sweden)

    Valérie Leduc

    2011-01-01

    Full Text Available 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.

  18. Apolipoprotein and lipid abnormalities in chronic liver failure

    Directory of Open Access Journals (Sweden)

    Spósito A.C.

    1997-01-01

    Full Text Available Total serum lipids, as well as apolipoproteins A-I (apo A-I and B (apo B, were determined in 74 patients with chronic liver failure without cholestasis and in 82 normal subjects. The VLDL, LDL and HDL lipid fractions were reduced in the liver failure group by 36%, 24% and 46%, respectively (P<0.001. Apolipoproteins A-I and B were also reduced by 26% and 25%, respectively (P<0.001. However, the reduction of HDL cholesterol (HDLc was more pronounced than that of apo A-I and the HDLc:apo A-I ratio was significantly lower in the liver failure group. After separating these patients into groups with plasma albumin lower than 3.0, between 3.0 and 3.5, and higher than 3.5 g/dl, the HDLc:apo A-I ratio was proportional to plasma albumin, but the correlation was not statistically significant. When these patients were separated by the Child classification of liver function, there was a correlation between the HDLc:apo A-I ratio and liver function. The differences in the HDLc:apo A-I ratio between the Child groups B and C, and A and C were statistically significant (P<0.05. We conclude that there is a more pronounced reduction in HDL cholesterol than in apo A-I in liver failure patients. Therefore, the HDLc:apo A-I ratio is a marker of liver function, probably because there is a decreased lecithin-cholesterol acyltransferase production by the diseased liver

  19. Apolipoprotein E polymorphism in northern Chinese elderly patients with coronary artery disease

    Institute of Scientific and Technical Information of China (English)

    Yangchun ZOU; Dayi HU; Xiufang HONG; Xingyuan JIA; Xinchun YANG; Liang CUI

    2006-01-01

    Background and objective Apolipoprotein E is a constituent of lipoproteins with considerable variation due to cysteine-arginine exchanges. We investigated the relationship between apo E gene polymorphism and the occurrence of coronary artery disease(CAD) in the older population of northern China. Methods The distribution of the HhaI polymorphisms of the apolipoprotein E gene was determined among 55 patients with CAD (CAD group), which was compared with that of 36 elderly subjects without CAD(control group). Results Genotype distributions at both sites (apo E gene 112-bp and 158-bp sites ) were different between the CAD and control groups. The CAD group had lower apolipoprotein E"ε2"frequencies than the control group (P<0.05). Conclusion Individuals with apolipoprotein E"ε2"are likely to have a reduced risk of developing coronary artery disease as demonstrated by elderly subjects in Northern China.

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

    Science.gov (United States)

    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.

  1. Correlation between mesenteric fat thickness and serum apolipoproteins in patients with peripheral arterial occlusive disease

    Directory of Open Access Journals (Sweden)

    Perelas Apostolos

    2012-10-01

    Full Text Available Abstract Background Visceral fat possesses the most detrimental potential for cardiovascular morbidity through the release of adipokines, as well as metabolic and proinflammatory mediators, which adversely affect metabolic and vascular homeostasis. Among the different types of visceral adipose tissue, mesenteric fat is considered particularly detrimental, due to its close proximity to the portal circulation, affecting directly the liver, which is the main regulator of body metabolic homeostasis. Mesenteric fat can be reliably estimated using abdominal ultrasonography, the only available imaging method able to depict individual mesenteric leaves. Aim of the present study was to investigate the correlation of mesenteric fat thickness (MFT with serum apolipoprotein levels in patients undergoing digital subtraction angiography in a single center. Methods 35 male patients with peripheral arterial disease were examined. After careful examination of the periumbilical area, the mesenteric leaves were identified. The maximal distance between each pair of sequential leaves was measured, and the mean value of the three thickest leaves was determined as the mesenteric fat thickness. Six apolipoprotein fasting serum concentrations were measured using a Luminex proteomics platform (xMAP Multiplex immunoassay: apolipoprotein A-I (apoAI, apolipoprotein A-II (apoAII, apolipoprotein B (apoB, apolipoprotein C-II (apoCII, apolipoprotein C-III (apoCIII and apolipoprotein E (apoE. Results MFT correlated with apoAII and apoB serum concentrations. The correlations with apoAII and apoB remained significant following correction for BMI. No correlations were noted between MFT and serum apoAI, apoCII, apoCIII or apoE levels before or after adjustment for BMI. Conclusions Our study indicates that MFT is significantly correlated with the concentration of atherogenic low density lipoproteins particles, as well as with apoAII, a determinant of free fatty acids levels. No

  2. Apolipoprotein E-specific innate immune response in astrocytes from targeted replacement mice

    Directory of Open Access Journals (Sweden)

    Montine Thomas J

    2006-04-01

    Full Text Available Abstract Background Inheritance of the three different alleles of the human apolipoprotein (apo E gene (APOE are associated with varying risk or clinical outcome from a variety of neurologic diseases. ApoE isoform-specific modulation of several pathogenic processes, in addition to amyloid β metabolism in Alzheimer's disease, have been proposed: one of these is innate immune response by glia. Previously we have shown that primary microglia cultures from targeted replacement (TR APOE mice have apoE isoform-dependent innate immune activation and paracrine damage to neurons that is greatest with TR by the ε4 allele (TR APOE4 and that derives from p38 mitogen-activated protein kinase (p38MAPK activity. Methods Primary cultures of TR APOE2, TR APOE3 and TR APOE4 astrocytes were stimulated with lipopolysaccharide (LPS. ApoE secretion, cytokine production, and nuclear factor-kappa B (NF-κB subunit activity were measured and compared. Results Here we showed that activation of primary astrocytes from TR APOE mice with LPS led to TR APOE-dependent differences in cytokine secretion that were greatest in TR APOE2 and that were associated with differences in NF-κB subunit activity. Conclusion Our results suggest that LPS activation of innate immune response in TR APOE glia results in opposing outcomes from microglia and astrocytes as a result of TR APOE-dependent activation of p38MAPK or NF-κB signaling in these two cell types.

  3. Mononuclear cell therapy reverts cuff-induced thrombosis in apolipoprotein E-deficient mice

    Directory of Open Access Journals (Sweden)

    Lima Leandro C F

    2012-07-01

    Full Text Available Abstract Background Stem/progenitor cell-based therapy has successfully been used as a novel therapeutic strategy for vascular diseases triggered by endothelial dysfunction. The aim of this study was to investigate the effects of mononuclear cell (MNC therapy in situ on carotid cuff-induced occlusive thrombus in the apolipoprotein E knockout (apoE-/- mouse. Methods Spleen-derived MNCs were isolated from green fluorescent protein (GFP-transgenic mice for cell treatment. A cuff-induced thrombus model was produced by placing a nonconstrictive silastic collar around the left common carotid artery in 20-week-old female apoE-/- mice. After 10 days, the cuff was removed, and the animals received in situ MNCs (Cuff-MNC or vehicle (Cuff-Vehicle and were compared with sham-operated animals (Sham. Results The histological analysis showed that the MNC treatment reverted occlusive thrombus formation compared to the vehicle and the vessel lumen area to that observed in the Sham group (MNC, 50 ± 4; Vehicle, 20 ± 4; Sham, 55 ± 2 x103 μm2; p -/- mice. Conclusion In situ short-term MNC therapy was able to revert cuff-induced occlusive thrombi in the carotid arteries of apoE-/- mice, possibly through the homing of EPCs, reduction of oxidative stress and decreased apoptosis.

  4. Acute exposure to apolipoprotein A1 inhibits macrophage chemotaxis in vitro and monocyte recruitment in vivo

    Science.gov (United States)

    Iqbal, Asif J; Barrett, Tessa J; Taylor, Lewis; McNeill, Eileen; Manmadhan, Arun; Recio, Carlota; Carmineri, Alfredo; Brodermann, Maximillian H; White, Gemma E; Cooper, Dianne; DiDonato, Joseph A; Zamanian-Daryoush, Maryam; Hazen, Stanley L; Channon, Keith M

    2016-01-01

    Apolipoprotein A1 (apoA1) is the major protein component of high-density lipoprotein (HDL) and has well documented anti-inflammatory properties. To better understand the cellular and molecular basis of the anti-inflammatory actions of apoA1, we explored the effect of acute human apoA1 exposure on the migratory capacity of monocyte-derived cells in vitro and in vivo. Acute (20–60 min) apoA1 treatment induced a substantial (50–90%) reduction in macrophage chemotaxis to a range of chemoattractants. This acute treatment was anti-inflammatory in vivo as shown by pre-treatment of monocytes prior to adoptive transfer into an on-going murine peritonitis model. We find that apoA1 rapidly disrupts membrane lipid rafts, and as a consequence, dampens the PI3K/Akt signalling pathway that coordinates reorganization of the actin cytoskeleton and cell migration. Our data strengthen the evidence base for therapeutic apoA1 infusions in situations where reduced monocyte recruitment to sites of inflammation could have beneficial outcomes. DOI: http://dx.doi.org/10.7554/eLife.15190.001 PMID:27572261

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

    Science.gov (United States)

    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.

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

    DEFF Research Database (Denmark)

    Nilsson, Stefan K; Lookene, Aivar; Beckstead, Jennifer A;

    2007-01-01

    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 densit...... 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. Udgivelsesdato: 2007-Mar-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...

  7. Cannabidiol-2',6'-dimethyl ether stimulates body weight gain in apolipoprotein E-deficient BALB/c. KOR/Stm Slc-Apoe(shl) mice.

    Science.gov (United States)

    Takeda, Shuso; Hirota, Rena; Teradaira, Sari; Takeda-Imoto, Masumi; Watanabe, Kazuhito; Toda, Akihisa; Aramaki, Hironori

    2015-12-01

    The biological activities of cannabidiol (CBD), a major non-psychotropic constituent of the fiber-type cannabis plant, have been examined in detail (e.g., CBD modulation of body weight in mice and rats). However, few studies have investigated the biological activities of cannabidiol-2',6'-dimethyl ether (CBDD), a dimethyl ether derivative of the parent CBD. We herein focused on the effects of CBDD on body weight changes in mice, and demonstrated that it stimulated body weight gain in apolipoprotein E (ApoE)-deficient BALB/c. KOR/Stm Slc-Apoe(shl) mice, especially between 10 and 20 weeks of age.

  8. Recombinant Neural Protein PrP Can Bind with Both Recombinant and Native Apolipoprotein E In Vitro

    Institute of Scientific and Technical Information of China (English)

    Chen GAO; Wei ZHOU; Xiao-Ping DONG; Yan-Jun LEI; Jun HAN; Qi SHI; Lan CHEN; Yan GUO; Yong-Jun GAO; Jian-Ming CHEN; Hui-Ying JIANG

    2006-01-01

    The most essential and crucial step during the pathogenesis of transmissible spongiform encephalopathy is the conformational change of cellular prion protein (PrPC) to pathologic isoform (prpSc). A lot of data revealed that caveolae-like domains (CLDs) in the cell surface were the probable place where the conversion of PrP proteins happened. Apolipoprotein E (ApoE) is an apolipoprotein which is considered to play an important role in the development of Alzheimer's disease and other neurodegenerative diseases by forming protein complex through binding to the receptor located in the clathrin-coated pits of the cell surface.In this study, a 914-bp cDNA sequence encoding human ApoE3 was amplified from neuroblastoma cell line SH-SY5Y. Three human ApoE isomers were expressed and purified from Escherichia coli. ApoE-specific antiserum was prepared by immunizing rabbits with the purified ApoE3. GST/His pull-down assay,immunoprecipitation and ELISA revealed that three full-length ApoE isomers interact with the recombinant full-length PrP protein in vitro. The regions corresponding to protein binding were mapped in the N-terminal segment of ApoE (amino acid 1-194) and the N-terminal of PrP (amino acid 23-90). Moreover, the recombinant PrP showed the ability to form a complex with the native ApoE from liver tissues. Our data provided direct evidence of molecular interaction between ApoE and PrP. It also supplied scientific clues for assessing the significance of CLDs on the surface of cellular membrane in the process of conformational conversion from PrPC to PrPSc and probing into the pathogenesis of transmissible spongiform encephalopathy.

  9. Polimorfisme Gen Apolipoprotein E Pada Penderita Sindrom Down Trisomi 21

    Directory of Open Access Journals (Sweden)

    Malinda Meinapuri

    2013-01-01

    Full Text Available AbstrakLatar Belakang: Sindrom Down merupakan suatu kelainan kromosom yang ditandai dengan adanya baik seluruhnya (trisomi 21 maupun sebagian (translokasi suatu salinan tambahan kromosom ke 21. Apolipoprotein E (APOE merupakan suatu bentuk protein polimorfik yang disandikan oleh suatu gen yang berlokasi pada lengan panjang kromosom 19 pada posisi 13.2 (19q13.2. Polimorfism gen APOE berkaitan dengan meningkatnya frekuensi alel ε4 yang berakibat terjadinya hambatan dalam percabangan dan pertumbuhan neuron. Dimungkinkan, penderita Sindrom Down Trisomi 21 memiliki gen APOE yang berbeda dengan kontrol sebagai faktor yang dapat mengakibatkan penuaan dini otak. Metode : Penelitian ini merupakan penelitian kasus kontrol untuk mengamati perbedaan distribusi dan frekuensi alel dan genotip gen APOE pada penderita Sindrom Down trisomi 21 dibandingkan dengan kontrol. Kasus Sindrom Down dan kontrol diambil dari data sekunder yang tersimpan di Center for Biomedical Research (CEBIOR Semarang Indonesia. Ekstraksi DNA dilakukan dengan menggunakan metode yang terdapat di (CEBIOR Semarang Indonesia. Kegiatan selanjutnya adalah pemeriksaan polimorfisme gen Apolipoprotein E dengan mengunakan teknik PCR dan RFLP. Hasil : Sebanyak 33 sampel dari penderita Sindrom Down, 18 laki-laki dan 15 perempuan dan 33 sampel kontrol, 18 laki-laki dan 15 perempuan. Baik sampel Sindrom Down maupun kontrol memiliki frekuensi alel ε3 paling tinggi dibandingkan dengan alel ε2 dan ε4. Pada Sindrom Down didapatkan alel ε4 4 sampel (6,1% dan alel ε2 8 sampel (12,1%. Baik sampel Sindrom Down maupun kontrol memiliki genotip ε3/ε3 paling tinggi dibandingkan dengan genotip gen APOE lainnya. Pada Sindrom Down didapatkan genotip ε2/ε4 4 sampel (12,1% dan genotip ε2/ε2 2 sampel (6,1%. Simpulan : Terdapat perbedaan distribusi alel dan genotip gen APOE pada penderita Sindrom Down trisomi 21 dibandingkan dengan kelompok kontrol. Diperlukan analisis sampel yang lebih banyak untuk

  10. HOMOLOGY MODELING AND MOLECULAR DYNAMICS STUDIES OF EC1 DOMAIN OF VE-CADHERIN TO ELUCIDATE DOCKING INTERACTION WITH CADHERIN-DERIVED PEPTIDE

    Directory of Open Access Journals (Sweden)

    Vivitri Dewi Prasasty

    2014-01-01

    Full Text Available VE-cadherin is a protein in the cadherin family that is found at the adherens junctions of the microvessel endothelial cells of the Blood-Brain Barrier (BBB. It is recognized as the homotypic cell adhesion molecules and there is limited structural information on how VE-cadherins mediate cell-cell adhesion. It has been shown that the EC1 domain of cadherins is important for the homophilic interactions for cell-cell adhesion. Therefore, the aims of this study are to model the structure of the EC1 domain of VE-cadherin, study its molecular dynamics properties and evaluate its interactions with cadherin peptides. In this study, the sequence alignment between EC1 domain of VE-cadherin and the template protein were conducted by CLUSTALW2 platform. The SWISS-MODEL platform performed the homology modeling of the EC1 domain of VE-cadherin structure. Structural refinement was done by using KOBAMIN. Some validation analysis platforms also were conducted included PROCHECK, VERIFY3D, ERRAT and MOLPROBITY to check the allowed residues region in Ramachandran Plot (RP and the quality of the structure. The most favored region was found 95.5% in RP value and overall model structure quality is 71.34%. Molecular Dynamics (MD was run under CABS-FLEX to determine the flexibility of the residue index. The RMSD value of MD is 1.5Å per residue index. Eventually, molecular docking by AUTODOCK VINA was conducted to investigate protein-ligand interaction. From docking, it is found that the affinity energy is -4.8 kcal/mol which has the most favorable binding of EC1 domain with the peptide.

  11. Summarization by domain ontology navigation

    DEFF Research Database (Denmark)

    Andreasen, Troels; Bulskov, Henrik

    2013-01-01

    of the subject. In between these two extremes, conceptual summaries encompass selected concepts derived using background knowledge. We address in this paper an approach where conceptual summaries are provided through a conceptualization as given by an ontology. The ontology guiding the summarization can...... be a simple taxonomy or a generative domain ontology. A domain ontology can be provided by a preanalysis of a domain corpus and can be used to condense improved summaries that better reflects the conceptualization of a given domain....

  12. Tau hyperphosphorylation in apolipoprotein E-deficient and control mice after closed head injury.

    Science.gov (United States)

    Genis, L; Chen, Y; Shohami, E; Michaelson, D M

    2000-05-15

    Apolipoprotein E (apoE)-deficient mice have learning and memory impairments that are associated with specific neurochemical changes and hyperphosphorylation of distinct epitopes of the cytoskeletal protein tau. Furthermore, such mice are highly susceptible to the sequelae of brain trauma and their ability to recover from head injury is impaired. In the present study we investigated the extent that the neuronal maintenance and repair impairments of apoE-deficient mice are related to aberrations at the tau phosphorylation level. This was pursued by subjecting control and apoE-deficient mice to closed head injury (CHI) and examination, utilizing immunoblot assays, of the resulting effects on tau phosphorylation. The results thus obtained revealed that tau of apoE-deficient mice is hyperphosphorylated before CHI and that this insult results in transient tau hyperphosphorylation, whose extent and time course in the two mouse groups varied markedly. Tau hyperphosphorylation in the injured controls was maximal by about 4 hr after injury and reverted to basal levels by 24 hr. In contrast, almost no head injury-induced tau hyperphosphorylation was observed in the apoE-deficient mice at 4 hr after injury. Some tau hyper-phosphorylation was detected in the head-injured apoE-deficient mice after longer time intervals, but its extent was markedly lower than the maximal values obtained in the head injured controls. These findings show that the chronic neuronal impairments brought about by apoE deficiency and the acute response to head injury are both associated with hyperphosphorylation of the same tau domain and that the ability of apoE-deficient mice to mount the acute tau hyperphosphorylation response to head injury is impaired.

  13. Discovery of the cell-penetrating function of A2 domain derived from LTA subunit of Escherichia coli heat-labile enterotoxin.

    Science.gov (United States)

    Liu, Di; Guo, Hua; Zheng, Wenyun; Zhang, Na; Wang, Tianwen; Wang, Ping; Ma, Xingyuan

    2016-06-01

    Heat-labile enterotoxin (LT) is a protein toxin produced by enterotoxigenic Escherichia coli (ETEC). As a bacterial toxin, LT holotoxin can enter intestinal epithelial cells and cause diarrhea. In addition, LT is also a powerful mucosal adjuvant capable of enhancing the strong immune responses to co-administered antigens. However, the LT immunological mechanism is still not clear in some aspects, especially with the respect to how the LTA subunit functions alone. Here, we discovered that the A2 domain of LTA could carry a fluorescent protein into cells, whose function is similar to a cell-penetrating peptide. The transmembrane-transporting ability of the A2 domain is non-specific in its cell-penetrating function, which was shown through testing with different cell types. Moreover, the LTA2 fusion protein penetrated a fluorescently labeled cell membrane that identified LTA2 internalization through membrane transport pathways, and showed it finally localized in the endoplasmic reticulum. Furthermore, low-temperature stress and pharmacological agent treatments showed that the LTA2 internalization route is a temperature-dependent process involving the clathrin-mediated endocytosis and the macropinocytosis pathways. These results could explain the internalization of the LTA subunit alone without the LTB pentamer, contributing to a better understanding of LTA working as a mucosal adjuvant; they also suggest that the A2 domain could be used as a novel transport vehicle for research and treatment of disease.

  14. Cardiomyocyte Regulation of Systemic Lipid Metabolism by the Apolipoprotein B-Containing Lipoproteins in Drosophila

    Science.gov (United States)

    Ishikawa, Zachary

    2017-01-01

    The heart has emerged as an important organ in the regulation of systemic lipid homeostasis; however, the underlying mechanism remains poorly understood. Here, we show that Drosophila cardiomyocytes regulate systemic lipid metabolism by producing apolipoprotein B-containing lipoproteins (apoB-lipoproteins), essential lipid carriers that are so far known to be generated only in the fat body. In a Drosophila genetic screen, we discovered that when haplo-insufficient, microsomal triglyceride transfer protein (mtp), required for the biosynthesis of apoB-lipoproteins, suppressed the development of diet-induced obesity. Tissue-specific inhibition of Mtp revealed that whereas knockdown of mtp only in the fat body decreases systemic triglyceride (TG) content on normal food diet (NFD) as expected, knockdown of mtp only in the cardiomyocytes also equally decreases systemic TG content on NFD, suggesting that the cardiomyocyte- and fat body-derived apoB-lipoproteins serve similarly important roles in regulating whole-body lipid metabolism. Unexpectedly, on high fat diet (HFD), knockdown of mtp in the cardiomyocytes, but not in fat body, protects against the gain in systemic TG levels. We further showed that inhibition of the Drosophila apoB homologue, apolipophorin or apoLpp, another gene essential for apoB-lipoprotein biosynthesis, affects systemic TG levels similarly to that of Mtp inhibition in the cardiomyocytes on NFD or HFD. Finally, we determined that HFD differentially alters Mtp and apoLpp expression in the cardiomyocytes versus the fat body, culminating in higher Mtp and apoLpp levels in the cardiomyocytes than in fat body and possibly underlying the predominant role of cardiomyocyte-derived apoB-lipoproteins in lipid metabolic regulation. Our findings reveal a novel and significant function of heart-mediated apoB-lipoproteins in controlling lipid homeostasis. PMID:28095410

  15. Skeletal muscle apolipoprotein B expression reduces muscular triglyceride accumulation

    DEFF Research Database (Denmark)

    Bartels, Emil D; Ploug, Thorkil; Størling, Joachim;

    2014-01-01

    Abstract Background. Lipid accumulation in skeletal muscle is associated with impaired insulin sensitivity in type 2 diabetes. In cardiac myocytes, lipoprotein secretion controlled by apolipoproteinB (apoB) and microsomal triglyceride transfer protein (MTP) affects lipid homeostasis. Design....... In this study, we investigated whether expression of a human apoB transgene affects triglyceride accumulation and insulin sensitivity in skeletal muscle in fat fed obese mice. Results. Expression of apoB and MTP mRNA and the human apoB transgene was seen in skeletal muscle of the transgene mice. Human apo......B transgenic mice accumulated 28% less triglycerides in skeletal myocytes after one year of fat-feeding as compared with WT mice (32 ± 5, n = 10 vs. 44 ± 4 nmol/mg ww, n = 13, p = 0.04). Moreover, expression of human apoB in fat-fed mice was associated with 32% (p = 0.02) and 37% (p = 0.01) lower plasma...

  16. Apolipoprotein E: Essential Catalyst of the Alzheimer Amyloid Cascade

    Directory of Open Access Journals (Sweden)

    Huntington Potter

    2012-01-01

    Full Text Available The amyloid cascade hypothesis remains a robust model of AD neurodegeneration. However, amyloid deposits contain proteins besides Aβ, such as apolipoprotein E (apoE. Inheritance of the apoE4 allele is the strongest genetic risk factor for late-onset AD. However, there is no consensus on how different apoE isotypes contribute to AD pathogenesis. It has been hypothesized that apoE and apoE4 in particular is an amyloid catalyst or “pathological chaperone”. Alternatively it has been posited that apoE regulates Aβ clearance, with apoE4 been worse at this function compared to apoE3. These views seem fundamentally opposed. The former would indicate that removing apoE will reduce AD pathology, while the latter suggests increasing brain ApoE levels may be beneficial. Here we consider the scientific basis of these different models of apoE function and suggest that these seemingly opposing views can be reconciled. The optimal therapeutic target may be to inhibit the interaction of apoE with Aβ rather than altering apoE levels. Such an approach will not have detrimental effects on the many beneficial roles apoE plays in neurobiology. Furthermore, other Aβ binding proteins, including ACT and apo J can inhibit or promote Aβ oligomerization/polymerization depending on conditions and might be manipulated to effect AD treatment.

  17. Apolipoprotein M in lipid metabolism and cardiometabolic diseases

    DEFF Research Database (Denmark)

    Borup, Anna; Christensen, Pernille Meyer; Nielsen, Lars B.

    2015-01-01

    PURPOSE: This review will address recent findings on apolipoprotein M (apoM) and its ligand sphingosine-1-phosphate (S1P) in lipid metabolism and inflammatory diseases. RECENT FINDINGS: ApoM's likely role(s) in health and disease has become more diverse after the discovery that apoM functions...... as a chaperone for S1P. Hence, apoM has recently been implicated in lipid metabolism, diabetes and rheumatoid arthritis through in-vivo, in-vitro and genetic association studies. It remains to be established to which degree such associations with apoM can be attributed to its ability to bind S1P. SUMMARY......: The apoM/S1P axis and its implications in atherosclerosis and lipid metabolism have been thoroughly studied. Owing to the discovery of the apoM/S1P axis, the scope of apoM research has broadened. ApoM and S1P have been implicated in lipid metabolism, that is by modulating HDL particles. Also...

  18. Glucose Regulates the Expression of the Apolipoprotein A5 Gene

    Energy Technology Data Exchange (ETDEWEB)

    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. Alzheimer's disease, apolipoprotein E and hormone replacement therapy.

    Science.gov (United States)

    Depypere, H; Vierin, A; Weyers, S; Sieben, A

    2016-12-01

    Alzheimer's disease is the most frequent cause of dementia in older patients. The prevalence is higher in women than in men. This may be the result of both the higher life expectancy of women and the loss of neuroprotective estrogen after menopause. Earlier age at menopause (spontaneous or surgical) is associated with an enhanced risk of developing Alzheimer's disease. Therefore, it is postulated that estrogen could be protective against it. If so, increasing exposure to estrogen through the use of postmenopausal hormone replacement could also be protective against Alzheimer's disease. The results of the clinical studies that have examined this hypothesis are inconclusive, however. One explanation for this is that estrogen treatment is protective only if it is initiated in the years immediately after menopause. Another possibility is that the neuroprotective effects of estrogen are negated by a particular genotype of apolipoprotein E. This protein plays an important role in cholesterol transport to the neurons. Studies that have examined the link between estrogen replacement therapy, Alzheimer's disease and the E4 allele of ApoE are inconclusive. This article reviews the literature on the influence of hormone replacement therapy on the incidence and progression of Alzheimer's disease.

  20. An apolipoprotein B100 mimotope prevents obesity in mice.

    Science.gov (United States)

    Kim, Hyo Joon; Lee, Hee Jong; Choi, Jung Soon; Han, Jemin; Kim, Ji Young; Na, Hyun Kyun; Joung, Hae-Jung; Kim, Young Sik; Binas, Bert

    2016-01-01

    Although apolipoprotein B100 (ApoB100) plays a key role in peripheral fat deposition, it is not considered a suitable therapeutic target in obesity. In the present study we describe a novel ApoB100 mimotope, peptide pB1, and the use of pB1-based vaccine-like formulations (BVFs) against high-fat diet (HFD)-induced obesity. In HFD- compared with chow-fed adolescent mice, BVFs reduced the 3-month body-weight gains attributable to increased dietary fat by 44-65%, and prevented mesenteric fat accumulation and liver steatosis. The body-weight reductions paralleled the titres of pB1-reactive immunoglobulin G (IgG) antibodies, and pB1-reactive antibodies specifically recognized native ApoB100 and a synthetic peptide from the C-terminal half of ApoB100. In cultured 3T3L1 adipocytes, anti-pB1 antibodies increased lipolysis and inhibited low-density lipoprotein (LDL) uptake. In cultured RAW 264.7 macrophages, the same antibodies enhanced LDL uptake (without causing foam cell formation). These findings make ApoB100 a promising target for an immunization strategy against HFD-induced obesity.

  1. The potential applications of Apolipoprotein E in personalized medicine

    Science.gov (United States)

    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

  2. Apolipoproteins A-I and B in Kuwaiti children.

    Science.gov (United States)

    Moussa, M A; Shaltout, A A; Nkansa-Dwamena, D; Mourad, M

    1998-01-01

    To assess the relation of apolipoproteins (Apos) A-I and B (the carrier proteins for high and low density lipoprotein cholesterol, respectively) with the degree of obesity, body fat distribution, serum lipids, glucose and insulin levels, a case-control study was carried out and included 460 Kuwaiti obese children, 6-13 years old, matched by age and sex to 460 normal-weight controls. Obese children were ascertained in a representative cross-sectional study of 2,400 school children. The Apo A-I levels were not different between obese and non-obese boys, while they were significantly lower in obese girls (p < 0.01). The Apo B mean concentrations were significantly higher in obese boys and girls (p < 0.001), while the Apo A-I:B ratio was significantly lower in obese children (p < 0.001). Apo A-I levels were positively correlated with total cholesterol, high- and low-density lipoprotein cholesterol, but were not correlated with very low-density lipoprotein cholesterol, triglycerides, insulin, glucose or insulin:glucose ratio. Apo B levels were negatively correlated with high-density lipoprotein cholesterol and positively correlated with insulin and insulin:glucose ratio (p < 0.01) in obese children. The study documented an adverse Apo profile in obese Kuwaiti children. Since Apo changes are correctable through management of obesity, their identification in childhood offers prospects for prevention of early onset atherogenesis in adulthood.

  3. Apolipoprotein D Internalization Is a Basigin-dependent Mechanism.

    Science.gov (United States)

    Najyb, Ouafa; Brissette, Louise; Rassart, Eric

    2015-06-26

    Apolipoprotein D (apoD), a member of the lipocalin family, is a 29-kDa secreted glycoprotein that binds and transports small lipophilic molecules. Expressed in several tissues, apoD is up-regulated under different stress stimuli and in a variety of pathologies. Numerous studies have revealed that overexpression of apoD led to neuroprotection in various mouse models of acute stress and neurodegeneration. This multifunctional protein is internalized in several cells types, but the specific internalization mechanism remains unknown. In this study, we demonstrate that the internalization of apoD involves a specific cell surface receptor in 293T cells, identified as the transmembrane glycoprotein basigin (BSG, CD147); more particularly, its low glycosylated form. Our results show that internalized apoD colocalizes with BSG into vesicular compartments. Down-regulation of BSG disrupted the internalization of apoD in cells. In contrast, overexpression of basigin in SH-5YSY cells, which poorly express BSG, restored the uptake of apoD. Cyclophilin A, a known ligand of BSG, competitively reduced apoD internalization, confirming that BSG is a key player in the apoD internalization process. In summary, our results demonstrate that basigin is very likely the apoD receptor and provide additional clues on the mechanisms involved in apoD-mediated functions, including neuroprotection.

  4. Transgenic Drosophila model to study apolipoprotein E4-induced neurodegeneration.

    Science.gov (United States)

    Haddadi, Mohammad; Nongthomba, Upendra; Jahromi, Samaneh Reiszadeh; Ramesh, S R

    2016-03-15

    The ε4 isoform of apolipoprotein E (ApoE4) that is involved in neuron-glial lipid metabolism has been demonstrated as the main genetic risk factor in late-onset of Alzheimer's disease. However, the mechanism underlying ApoE4-mediated neurodegeneration remains unclear. We created a transgenic model of neurodegenerative disorder by expressing ε3 and ε4 isoforms of human ApoE in the Drosophila melanogaster. The genetic models exhibited progressive neurodegeneration, shortened lifespan and memory impairment. Genetic interaction studies between amyloid precursor protein and ApoE in axon pathology of the disease revealed that over expression of hApoE in Appl-expressing neurons of Drosophila brain causes neurodegeneration. Moreover, acute oxidative damage in the hApoE transgenic flies triggered a neuroprotective response of hApoE3 while chronic induction of oxidative damage accelerated the rate of neurodegeneration. This Drosophila model may facilitate analysis of the molecular and cellular events implicated in hApoE4 neurotoxicity.

  5. Genetic Variability of Apolipoprotein E in Different Populations from Venezuela

    Directory of Open Access Journals (Sweden)

    M. T. Fernández-Mestre

    2005-01-01

    Full Text Available The genetic variation at the Apolipoprotein E locus (APOE is an important determinant of plasma lipids and has been implicated in various human pathological conditions. The objective of the present study was to estimate the distribution of APOE alleles in five Venezuelan communities: two Amerindian tribes (Bari and Yucpa, one Negroid population from Curiepe, one Caucasoid population from Colonia Tovar and the mestizo urban population living in Caracas. The APOE*3 allele was the most common allele in all populations studied. However, a significant increase in the APOE*2 allele frequency in the Mestizo (18.96% and Negroid (16.25% populations was found. Similar to results reported in other Native American populations we have found that the APOE*2 allele is completely absent in the Bari and Yucpa Amerindians. Frequencies found in the Colonia Tovar population are in agreement with those reported in the population of Germany, indicating a high degree of relatedness. The results support the notion that the distribution of the APOE alleles shows ethnic variability.

  6. Concentration of apolipoprotein B is comparable with the apolipoprotein B/apolipoprotein A-I ratio and better than routine clinical lipid measurements in predicting coronary heart disease mortality: findings from a multi-ethnic US population

    Science.gov (United States)

    Sierra-Johnson, Justo; Fisher, Rachel M.; Romero-Corral, Abel; Somers, Virend K.; Lopez-Jimenez, Francisco; Öhrvik, John; Walldius, Göran; Hellenius, Mai-Lis; Hamsten, Anders

    2009-01-01

    Aims Prospective studies indicate that apolipoprotein measurements predict coronary heart disease (CHD) risk; however, evidence is conflicting, especially in the US. Our aim was to assess whether measurements of apolipoprotein B (apoB) and apolipoprotein A-I (apoA-I) can improve the ability to predict CHD death beyond what is possible based on traditional cardiovascular (CV) risk factors and clinical routine lipid measurements. Methods and results We analysed prospectively associations of apolipoprotein measurements, traditional CV risk factors, and clinical routine lipid measurements with CHD mortality in a multi-ethnic representative subset of 7594 US adults (mean age 45 years; 3881 men and 3713 women, median follow-up 124 person-months) from the Third National Health and Nutrition Examination Survey mortality study. Multiple Cox-proportional hazards regression was applied. There were 673 CV deaths of which 432 were from CHD. Concentrations of apoB [hazard ratio (HR) 1.98, 95% confidence interval (CI) 1.09–3.61], apoA-I (HR 0.48, 95% CI 0.27–0.85) and total cholesterol (TC) (HR 1.17, 95% CI 1.02–1.34) were significantly related to CHD death, whereas high density lipoprotein cholesterol (HDL-C) (HR 0.68, 95% CI 0.45–1.05) was borderline significant. Both the apoB/apoA-I ratio (HR 2.14, 95% CI 1.11–4.10) and the TC/HDL-C ratio (HR 1.10, 95% CI 1.04–1.16) were related to CHD death. Only apoB (HR 2.01, 95% CI 1.05–3.86) and the apoB/apoA-I ratio (HR 2.09, 95% CI 1.04–4.19) remained significantly associated with CHD death after adjusting for CV risk factors. Conclusion In the US population, apolipoprotein measurements significantly predict CHD death, independently of conventional lipids and other CV risk factors (smoking, dyslipidaemia, hypertension, obesity, diabetes and C-reactive protein). Furthermore, the predictive ability of apoB alone to detect CHD death was better than any of the routine clinical lipid measurements. Inclusion of apolipoprotein

  7. Phage Display Approaches for the Isolation of Monoclonal Antibodies Against Dengue Virus Envelope Domain III from Human and Mouse Derived Libraries

    Directory of Open Access Journals (Sweden)

    Subhash G. Vasudevan

    2012-02-01

    Full Text Available Domain III of the dengue virus envelope protein (EDIII, aa295-395 has an immunoglobulin fold and is the proposed receptor-binding domain of the virus. Previous studies have shown that monoclonal antibodies against EDIII can be neutralizing and have therapeutic potential. Here, cloned Fab-phage libraries of human and mouse origin were screened for DENV specific antibodies. Firstly, bacterially expressed EDIII or whole virus particles were used as bait in biopanning against a large naïve human Fab-phage library ( > 10 billion independent clones. Multiple panning strategies were employed, and in excess of 1000 clones were screened, but all of the antibodies identified bound the envelope in regions outside EDIII suggesting EDIII antibodies are virtually absent from the naïve human repertoire. Next, a chimeric Fab-phage library was constructed from a panel of EDIII specific mouse hybridomas by pooling the VH and VL chain sequences from the hybridomas and cloning these into the pComb3X phagemid vector with human CH and CL encoding sequences. Biopanning against EDIII identified a unique antibody (C9 that cross-reacts with EDIII from DENV1-3 and, in the IgG format, binds and neutralizes DENV2 in cell-based assays. Sequence analysis and saturation mutagenesis of complementary determining regions (CDR in the C9 light chain suggest an antigen recognition model in which the LCDR3 is a key determinant of EDIII specificity, while modifications in LCDR1 and LCDR2 affect DENV serotype cross-reactivity. Overall, this study supports the current prevailing opinion that neutralizing anti-EDIII monoclonal antibodies can be readily generated in murine systems, but in humans the anti-DENV immune response is directed away from domain III.

  8. Optimisation and evaluation of restriction fragment length polimorfism method for apolipoprotein E

    Directory of Open Access Journals (Sweden)

    Drljević Nevena

    2014-01-01

    Full Text Available Introduction. Apolipoprotein E gene polymorphism is characterized by the presence of three common alleles, e2, e3 and e4, which encode three isoforms of apolipoprotein E in plasma E2, E3 and E4. Genetic polymorphisms of apolipoprotein E gene are predictive markers for the development of numerous disorders of lipid metabolism, already proven in a large number of clinical trials. This study was aimed at assessing the success rate of restriction fragment length polymorphism method for the detections of genes coding for isoenzymes E2, E3 and E4. Material and Methods. Deoxyribonucleic acid, used in this study, was extracted from blood by standard procedure using chloroform and phenol. The polymerase chain reaction method was used to amplify the coding sequence of fourth exon of the apolipoprotein E gene. Amplification products were digested with HhaI. The fragments obtained were separated by electrophoresis and visualized with ultraviolet light. Results. Our results showed that the restriction fragment length polymorphism method is optimal for detection of apolipoprotein E polymorphisms. The restriction enzyme HhaI achieved the cleavage of the gene on the specific loci, directly depend of presence or absence of mutations at positions 112 and 158, of different alleles. Conclusion. This method enables simple, rapid and efficient analysis of restriction fragment length polymorphisms, directly determining the patient’s genotype.

  9. Structures of the human poly (ADP-ribose glycohydrolase catalytic domain confirm catalytic mechanism and explain inhibition by ADP-HPD derivatives.

    Directory of Open Access Journals (Sweden)

    Julie A Tucker

    Full Text Available Poly(ADP-ribose glycohydrolase (PARG is the only enzyme known to catalyse hydrolysis of the O-glycosidic linkages of ADP-ribose polymers, thereby reversing the effects of poly(ADP-ribose polymerases. PARG deficiency leads to cell death whilst PARG depletion causes sensitisation to certain DNA damaging agents, implicating PARG as a potential therapeutic target in several disease areas. Efforts to develop small molecule inhibitors of PARG activity have until recently been hampered by a lack of structural information on PARG. We have used a combination of bio-informatic and experimental approaches to engineer a crystallisable, catalytically active fragment of human PARG (hPARG. Here, we present high-resolution structures of the catalytic domain of hPARG in unliganded form and in complex with three inhibitors: ADP-ribose (ADPR, adenosine 5'-diphosphate (hydroxymethylpyrrolidinediol (ADP-HPD and 8-n-octyl-amino-ADP-HPD. Our structures confirm conservation of overall fold amongst mammalian PARG glycohydrolase domains, whilst revealing additional flexible regions in the catalytic site. These new structures rationalise a body of published mutational data and the reported structure-activity relationship for ADP-HPD based PARG inhibitors. In addition, we have developed and used biochemical, isothermal titration calorimetry and surface plasmon resonance assays to characterise the binding of inhibitors to our PARG protein, thus providing a starting point for the design of new inhibitors.

  10. Increases thermal stability and cellulose-binding capacity of Cryptococcus sp. S-2 lipase by fusion of cellulose binding domain derived from Trichoderma reesei

    Energy Technology Data Exchange (ETDEWEB)

    Thongekkaew, Jantaporn, E-mail: jantaporn_25@yahoo.com [Department of Biological Science, Faculty of Science, Ubon-Ratchathani University, Warinchumrab, Ubon-Ratchathani 34190 (Thailand); Ikeda, Hiroko; Iefuji, Haruyuki [Application Research Division, National Research Institute of Brewing, 3-7-1 Kagamiyama, Higashi-Hiroshima 739-0046 (Japan)

    2012-03-30

    Highlights: Black-Right-Pointing-Pointer The CSLP and fusion enzyme were successfully expressed in the Pichia pastoris. Black-Right-Pointing-Pointer The fusion enzyme was stable at 80 Degree-Sign C for 120-min. Black-Right-Pointing-Pointer The fusion enzyme was responsible for cellulose-binding capacity. Black-Right-Pointing-Pointer The fusion enzyme has an attractive applicant for enzyme immobilization. -- Abstract: To improve the thermal stability and cellulose-binding capacity of Cryptococcus sp. S-2 lipase (CSLP), the cellulose-binding domain originates from Trichoderma reesei cellobiohydrolase I was engineered into C-terminal region of the CSLP (CSLP-CBD). The CSLP and CSLP-CBD were successfully expressed in the Pichia pastoris using the strong methanol inducible alcohol oxidase 1 (AOX1) promoter and the secretion signal sequence from Saccharomyces cerevisiae ({alpha} factor). The recombinant CSLP and CSLP-CBD were secreted into culture medium and estimated by SDS-PAGE to be 22 and 27 kDa, respectively. The fusion enzyme was stable at 80 Degree-Sign C and retained more than 80% of its activity after 120-min incubation at this temperature. Our results also found that the fusion of fungal exoglucanase cellulose-binding domain to CSLP is responsible for cellulose-binding capacity. This attribute should make it an attractive applicant for enzyme immobilization.

  11. A new phenylalanine derivative acts as an antagonist at the AMPA receptor GluA2 and introduces partial domain closure

    DEFF Research Database (Denmark)

    Szymanska, Ewa; Frydenvang, Karla; Contreras-Sanz, Alberto;

    2011-01-01

    In order to map out molecular determinants for competitive blockade of AMPA receptor subtypes, a series of 2-carboxyethylphenylalanine derivatives has been synthesized and pharmacologically characterized in vitro. One compound in this series, (RS)-3h, showed micromolar affinity for GluA1(o) and G...

  12. Common and rare alleles in apolipoprotein B contribute to plasma levels of low-density lipoprotein cholesterol in the general population

    DEFF Research Database (Denmark)

    Benn, M.; Stene, Maria Charlotte Aslaug; Nordestgaard, Børge;

    2008-01-01

    demonstrated to affect low-density lipoprotein (LDL) cholesterol levels. Objective: We tested the hypothesis that nonsynonymous SNPs in three important functional domains of APOB and APOB tag SNPs predict levels of LDL cholesterol and apolipoprotein B and risk of ischemic heart disease. Design......: This was a prospective study with 25 yr 100% follow up, The Copenhagen City Heart Study. Setting: The study was conducted in the Danish general population. Participants: Participants included 9185 women and men aged 20-80+ yr. Main Outcome Measures: Levels of LDL cholesterol and apolipoprotein B and risk of ischemic...... (0.21), R3611Q (0.09), E4154K (0.17), and N4311S (0.21). SNPs were associated with increases (T71I, Ivs181708g > t, T2488Tc > t, R3611) or decreases (Ivs4 + 171c > a, A591V, Ivs18 + 379a > c, P2712L, E4154, N4311S) in LDL cholesterol from -4.7 to +8.2% (-0.28 to 0.30 mmol/liter; P

  13. Apolipoprotein A1 in channel catfish: Transcriptional analysis, antimicrobial activity, and efficacy as plasmid DNA immunostimulant against Aeromonas hydrophila infection

    Science.gov (United States)

    The objectives of this study were to: 1) determine transcriptional profiles of apolipoprotein A1 (ApoA1) in collected channel catfish tissues after infection with A. hydrophila by bath immersion; 2) investigate whether recombinant channel catfish apolipoprotein A1 produced in E. coli expression syst...

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

    Directory of Open Access Journals (Sweden)

    Fatemehsadat Amjadi

    2015-01-01

    Full Text Available 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.

  15. Apolipoprotein B levels, APOB alleles, and risk of ischemic cardiovascular disease in the general population, a review

    DEFF Research Database (Denmark)

    Benn, Marianne

    2009-01-01

    . The present review examines, with focus on general population studies, apolipoprotein B levels as a predictor of ischemic cardiovascular disease, as well as the association of mutations and polymorphisms in APOB with plasma apolipoprotein B levels, and risk of ischemic cardiovascular disease. The studies can......, or ischemic stroke in the general population....

  16. Atherosclerosis, apolipoprotein E and the prevalence of dementia and Alzheimer's disease in a population-based study: the Rotterdam Study

    NARCIS (Netherlands)

    A. Ott (Alewijn); M.L. Bots (Michiel); A.J.C. Slooter (Arjen); F. van Harskamp (Frans); C.M. van Duijn (Cock); D.E. Grobbee (Diederick); M.M.B. Breteler (Monique); C. van Broeckhoven (Christine); A. Hofman (Albert)

    1997-01-01

    textabstractBACKGROUND: Vascular disorders have been implicated in dementia, but whether atherosclerosis is related to the most frequent type of dementia, Alzheimer's disease, is not known. The apolipoprotein-E genotype has been associated with Alzheimer's disease, and we postulate that it plays a p

  17. Conformational and aggregation properties of the 1-93 fragment of apolipoprotein A-I

    DEFF Research Database (Denmark)

    Petrlova, Jitka; Bhattacherjee, Arnab; Boomsma, Wouter Krogh;

    2014-01-01

    Several disease-linked mutations of apolipoprotein A-I, the major protein in high-density lipoprotein (HDL), are known to be amyloidogenic, and the fibrils often contain N-terminal fragments of the protein. Here, we present a combined computational and experimental study of the fibril-associated ......Several disease-linked mutations of apolipoprotein A-I, the major protein in high-density lipoprotein (HDL), are known to be amyloidogenic, and the fibrils often contain N-terminal fragments of the protein. Here, we present a combined computational and experimental study of the fibril...... that these conformational shifts match well with the effects of these mutations in thioflavin T fluorescence and transmission electron microscopy experiments. Together, our results point to molecular mechanisms that may have a key role in disease-linked aggregation of apolipoprotein A-I....

  18. Toll-like receptor 2 and nucleotide-binding oligomerization domain-2 play divergent roles in the recognition of gut-derived lactobacilli and bifidobacteria in dendritic cells

    DEFF Research Database (Denmark)

    Zeuthen, Louise; Fink, Lisbeth Nielsen; Frøkiær, Hanne

    2008-01-01

    -marrow-derived DC lacking NOD2 produce higher levels of interleukin-10 (IL-10) and reduced levels of IL-12 and tumour necrosis factor-[alpha] (TNF-[alpha]) in response to LAB. This indicates that peptidoglycan is partly responsible for the T helper type 1 skewing effect of certain LAB. Dendritic cells that are TLR2......-/- produce less IL-12 and TNF-[alpha] and more IL-10 in response to some strains of lactobacilli, while they produce more IL-12 and less IL-10 in response to bifidobacteria. The same tendency was found in human monocyte-derived DC. We have previously reported that the weak IL-12-inducing and TNF......-[alpha]-inducing bifidobacteria inhibit the T helper type 1 skewing effect induced by strong immunostimulatory lactobacilli. Here we show that this immunoinhibitory effect of bifidobacteria is dependent on TLR2 and independent of NOD2. Moreover, independently of the cytokine pattern induced by intact LAB, cell wall fractions...

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

    Energy Technology Data Exchange (ETDEWEB)

    Lasrich, Dorothee; Bartelt, Alexander [Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg (Germany); Grewal, Thomas, E-mail: thomas.grewal@sydney.edu.au [Faculty of Pharmacy A15, The University of Sydney, Sydney, NSW 2006 (Australia); Heeren, Joerg, E-mail: heeren@uke.de [Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg (Germany)

    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.

  20. Apolipoprotein E and its role in aging and survival.

    Science.gov (United States)

    Bonomini, Francesca; Filippini, Francesca; Hayek, Tony; Aviram, Michael; Keidar, Shlomo; Rodella, Luigi F; Coleman, Raymond; Rezzani, Rita

    2010-02-01

    The study of biological aging has seen spectacular progress in the last decade and markers are increasingly employed for understanding physiological processes that change with age. Recently, it has been demonstrated that apolipoprotein E (apoE) has a major impact on longevity, but its mechanisms are still not fully understood. ApoE-deficient (E(o)) mice have proved to be a very popular model for studying spontaneous hypercholesterolemia and the subsequent development of atherosclerotic lesions, but only limited data are available with regard to aging and aging changes. We used this murine model to better characterize the involvement of apoE in aging and to evaluate its role in the maintenance of normal organ morphology. Our results show that E(0) mice at different ages (6, 12, 20 weeks old) developed age-dependent morphological and biochemical alterations, including fibrosis (newly formed collagen), pro-inflammatory cytokine (IL-6 and iNOS), lipofuscin accumulation, and decrease of antioxidant enzymes (superoxide dismutase and catalase) in several organs (kidney, liver and heart). It is significant that the observed degenerative findings in E(0) mice at different ages (6, 12, 20 weeks old) were not identified in control mice (C57BL), at 6, 12 and 20 weeks of age. Consequently, since these mice showed enzymatic and structural alterations, normally linked to the age, such as increase of lipofuscin, pro-inflammatory cytokines and decrease of antioxidant enzymes, we can conclude that apoE is a useful player in studies of longevity and age-related diseases, such as inflammatory status and atherosclerosis that are known risk factors for functional decline and early mortality. Moreover, it is possible that apoE may also play a role in other pathological conditions including, for example, cancer, rheumatoid arthritis and macular degeneration.

  1. Heterogeneity of apolipoprotein E polymorphism in different Mexican populations.

    Science.gov (United States)

    Aceves, Dolores; Ruiz, Bertha; Nuño, Patricia; Roman, Sonia; Zepeda, Eloy; Panduro, Arturo

    2006-02-01

    Mexico has approximately 100 million inhabitants. Most of the urban Mexican population has been considered mestizo (Indian and Spanish descent), whereas the Indian population predominates in rural areas and small towns in the countryside. In this study we analyzed the apolipoprotein E (APOE) polymorphism in Guadalajara (the second largest metropolitan area of Mexico) and its surrounding areas, two adjoining states (Nayarit and Durango), and an Indian town (Huichol Indians) from western Mexico. APOE*3 was the most common allele, and APOE*3/*3 was the most common genotype in all populations studied. Guadalajara revealed the highest frequency of the APOE*2 allele (7.8%); the frequency decreased in the rural area (4.4%), followed by Nayarit (1.6%), and was absent in Durango and in the Huichols. On the contrary, the lowest frequency of the APOE*4 allele was in Guadalajara (8.4%); the frequency increased in the rural area (9.3%), in Nayarit and Durango (11.5% and 11.7%), and reached a high frequency in the Huichol Indians (28%). The distribution of the APOE allele in the western population of Mexico is similar to those described in Mexican American migrants living in the United States but is different from those populations living in Mexico City. This study shows the heterogeneity of the Mexican population, where the frequency of the APOE*2 allele is higher in Guadalajara than in other urban areas of Mexico and is similar to frequencies described in the Caucasian population. On the contrary, the Huichols revealed the highest frequency of the APOE*4 allele in Mexico and in the Americas. This information could be useful for the study of dyslipidemias associated with chronic diseases and as markers of ethnic variation in the Americas.

  2. Molecular characterization and developmental expression pattern of the chicken apolipoprotein D gene: implications for the evolution of vertebrate lipocalins.

    Science.gov (United States)

    Ganfornina, María D; Sánchez, Diego; Pagano, Aldo; Tonachini, Laura; Descalzi-Cancedda, Fiorella; Martínez, Salvador

    2005-01-01

    The insect Lazarillo and the mammalian apolipoprotein D (ApoD) are orthologous members of the lipocalin protein family. We report the cloning and embryonic expression of chicken ApoD, the first molecularly characterized nonmammalian ApoD. We also report the ApoD expression in mouse during postnatal development and some novel aspects of the expression of the paralogous lipocalin prostaglandin D-synthase (PGDS) and discuss these results in view of the lipocalin family evolution in vertebrates. ApoD is expressed in subsets of central nervous system (CNS) neurons and glia during late chicken embryogenesis. Contrary to mouse ApoD, no expression appears in neural crest-derived cephalic mesenchyme and blood vessel pericytes. Also, ApoD is expressed in developing chicken feathers. These expressions are corroborated by quantitative reverse transcriptase-polymerase chain reaction profiles. ApoD is expressed during mouse postnatal development in a subset of CNS neurons, astrocytes and oligodendrocytes, but also in meninges and pericytes. Chicken PGDS is expressed in brain meninges and perivascular cells. Our results suggest that the amniote last common ancestor expressed ApoD and PGDS in the brain during embryogenesis. ApoD appears restricted to ectodermal derivatives, whereas PGDS is expressed by derivatives of the three germ layers.

  3. Apolipoprotein E genotype and hepatitis C, HIV and herpes simplex disease risk: a literature review

    Directory of Open Access Journals (Sweden)

    Nebel Almut

    2010-01-01

    Full Text Available Abstract Apolipoprotein E is a polymorphic and multifunctional protein with numerous roles in lipoprotein metabolism. The three common isoforms apoE2, apoE3 and apoE4 show isoform-specific functional properties including different susceptibilities to diseases. ApoE4 is an accepted risk factor for Alzheimer's disease and cardiovascular disorders. Recently, associations between apoE4 and infectious diseases have been demonstrated. This review summarises how apoE4 may be involved in the infection incidence and associated pathologies of specific infectious diseases, namely hepatitis C, human immunodeficiency virus disease and herpes simplex. ApoE4 seems to be protective against chronic hepatitis C virus infection and retards fibrosis progression. In contrast apoE4 enhances the fusion rate of human immunodeficiency virus with target cell membranes, resulting in accelerated cell entry and faster disease progression. Its association with human immunodeficiency virus-associated dementia remains controversial. Regarding herpes simplex virus infection, apoE4 intensifies virus latency and is associated with increased oxidative damage of the central nervous system, and there is some evidence that herpes simplex virus infection in combination with the apoE4 genotype may be associated with an increased risk of Alzheimer's disease. In addition to reviewing available data from human trials, evidence derived from a variety of cell culture and animal models are considered in this review in order to provide mechanistic insights into observed association between apoE4 genotype and viral disease infection and pathology.

  4. Chromosomal localization of the human apolipoprotein B gene and detection of homologous RNA in monkey intestine

    Energy Technology Data Exchange (ETDEWEB)

    Deeb, S.S.; Disteche, C.; Motulsky, A.G.; Lebo, R.V.; Kan, Y.W.

    1986-01-01

    A cDNA clone of the human apolipoprotein B-100 was used as a hybridization probe to detect homologous sequences in both flow-sorted and in situ metaphase chromosomes. The results indicate that the gene encoding this protein is on the distal end of the short arm of chromosome 2 (2p23-2p24). RNA isolated from monkey small intestine contained sequences (6.5 and 18 kilobases) homologous to the cDNA of apolipoprotein B-100. These results are consistent with the hypothesis that one gene codes for both the intestinal (B-48) and the hepatic (B-100) forms.

  5. Membrane curvature induction and tubulation are common features of synucleins and apolipoproteins

    DEFF Research Database (Denmark)

    Varkey, Jobin; Isas, Jose Mario; Mizuno, Naoko

    2010-01-01

    Synucleins and apolipoproteins have been implicated in a number of membrane and lipid trafficking events. Lipid interaction for both types of proteins is mediated by 11 amino acid repeats that form amphipathic helices. This similarity suggests that synucleins and apolipoproteins might have...... of amphipathic helices alone. Moreover, we frequently observed that a-synuclein caused membrane structures that had the appearance of nascent budding vesicles. The ability to function as a minimal machinery for vesicle budding agrees well with recent findings that a-synuclein plays a role in vesicle trafficking...

  6. Insights into the initiation of JC virus DNA replication derived from the crystal structure of the T-antigen origin binding domain.

    Directory of Open Access Journals (Sweden)

    Gretchen Meinke

    2014-02-01

    Full Text Available JC virus is a member of the Polyomavirus family of DNA tumor viruses and the causative agent of progressive multifocal leukoencephalopathy (PML. PML is a disease that occurs primarily in people who are immunocompromised and is usually fatal. As with other Polyomavirus family members, the replication of JC virus (JCV DNA is dependent upon the virally encoded protein T-antigen. To further our understanding of JCV replication, we have determined the crystal structure of the origin-binding domain (OBD of JCV T-antigen. This structure provides the first molecular understanding of JCV T-ag replication functions; for example, it suggests how the JCV T-ag OBD site-specifically binds to the major groove of GAGGC sequences in the origin. Furthermore, these studies suggest how the JCV OBDs interact during subsequent oligomerization events. We also report that the OBD contains a novel "pocket"; which sequesters the A1 & B2 loops of neighboring molecules. Mutagenesis of a residue in the pocket associated with the JCV T-ag OBD interfered with viral replication. Finally, we report that relative to the SV40 OBD, the surface of the JCV OBD contains one hemisphere that is highly conserved and one that is highly variable.

  7. Structure and Bioactivity of a Modified Peptide Derived from the LPS-Binding Domain of an Anti-Lipopolysaccharide Factor (ALF of Shrimp

    Directory of Open Access Journals (Sweden)

    Hui Yang

    2016-05-01

    Full Text Available The lipopolysaccharide binding domain (LBD in anti-lipopolysaccharide factor (ALF is the main functional element of ALF, which exhibits antimicrobial activities. Our previous studies show that the peptide LBDv, synthesized based on the modified sequence of LBD (named LBD2 from FcALF2, exhibited an apparently enhanced antimicrobial activity. To learn the prospect of LBDv application, the characteristics of LBDv were analyzed in the present study. The LBDv peptide showed higher antimicrobial and bactericidal activities compared with LBD2. These activities of the LBDv peptide were stable after heat treatment. LBDv could also exhibit in vivo antimicrobial activity to Vibrio harveyi. The LBDv peptide was found to bind bacteria, quickly cause bacterial agglutination, and kill bacteria by damaging their membrane integrity. Structure analysis showed that both LBDv and LBD2 held the β-sheet structure, and the positive net charge and amphipathicity characteristic were speculated as two important components for their antimicrobial activity. The cytotoxicity of LBDv was evaluated in cultured Spodoptera frugiperda (Sf9 cells and Cherax quadricarinatus hemocytes. More than 80% cells could survive with the LBDv concentration up to 16 μM. Collectively, these findings highlighted the potential antimicrobial mechanism of LBD peptides, and provided important information for the commercial use of LBDv in the future.

  8. Intralipid decreases apolipoprotein M levels and insulin sensitivity in rats.

    Directory of Open Access Journals (Sweden)

    Lu Zheng

    Full Text Available BACKGROUND: Apolipoprotein M (ApoM is a constituent of high-density lipoproteins (HDL. It plays a crucial role in HDL-mediated reverse cholesterol transport. Insulin resistance is associated with decreased ApoM levels. AIMS: To assess the effects of increased free fatty acids (FFAs levels after short-term Intralipid infusion on insulin sensitivity and hepatic ApoM gene expression. METHODS: Adult male Sprague-Dawley (SD rats infused with 20% Intralipid solution for 6 h. Glucose infusion rates (GIR were determined by hyperinsulinemic-euglycemic clamp during Intralipid infusion and plasma FFA levels were measured by colorimetry. Rats were sacrificed after Intralipid treatment and livers were sampled. Human embryonic kidney 293T cells were transfected with a lentivirus mediated human apoM overexpression system. Goto-Kakizaki (GK rats were injected with the lentiviral vector and insulin tolerance was assessed. Gene expression was assessed by real-time RT-PCR and PCR array. RESULTS: Intralipid increased FFAs by 17.6 folds and GIR was decreased by 27.1% compared to the control group. ApoM gene expression was decreased by 40.4% after Intralipid infusion. PPARβ/δ expression was not changed by Intralipid. Whereas the mRNA levels of Acaca, Acox1, Akt1, V-raf murine sarcoma 3611 viral oncogene homolog, G6pc, Irs2, Ldlr, Map2k1, pyruvate kinase and RBC were significantly increased in rat liver after Intralipid infusion. The Mitogen-activated protein kinase 8 (MAPK8 was significantly down-regulated in 293T cells overexpressing ApoM. Overexpression of human ApoM in GK rats could enhance the glucose-lowering effect of exogenous insulin. CONCLUSION: These results suggest that Intralipid could decrease hepatic ApoM levels. ApoM overexpression may have a potential role in improving insulin resistance in vivo and modulating apoM expression might be a future therapeutic strategy against insulin resistance in type 2 diabetes.

  9. Sildenafil restores endothelial function in the apolipoprotein E knockout mouse

    Directory of Open Access Journals (Sweden)

    Balarini Camille M

    2013-01-01

    Full Text Available Abstract Background Atherosclerosis is an inflammatory process of the arterial walls and is initiated by endothelial dysfunction accompanied by an imbalance in the production of reactive oxygen species (ROS and nitric oxide (NO. Sildenafil, a selective phosphodiesterase-5 (PDE5 inhibitor used for erectile dysfunction, exerts its cardiovascular effects by enhancing the effects of NO. The aim of this study was to investigate the influence of sildenafil on endothelial function and atherosclerosis progression in apolipoprotein E knockout (apoE−/− mice. Methods ApoE−/− mice treated with sildenafil (Viagra®, 40 mg/kg/day, for 3 weeks, by oral gavage were compared to the untreated apoE−/− and the wild-type (WT mice. Aortic rings were used to evaluate the relaxation responses to acetylcholine (ACh in all of the groups. In a separate set of experiments, the roles of NO and ROS in the relaxation response to ACh were evaluated by incubating the aortic rings with L-NAME (NO synthase inhibitor or apocynin (NADPH oxidase inhibitor. In addition, the atherosclerotic lesions were quantified and superoxide production was assessed. Results Sildenafil restored the vasodilator response to acetylcholine (ACh in the aortic rings of the apoE−/− mice. Treatment with L-NAME abolished the vasodilator responses to ACh in all three groups of mice and revealed an augmented participation of NO in the endothelium-dependent vasodilation in the sildenafil-treated animals. The normalized endothelial function in sildenafil-treated apoE−/− mice was unaffected by apocynin highlighting the low levels of ROS production in these animals. Moreover, morphological analysis showed that sildenafil treatment caused approximately a 40% decrease in plaque deposition in the aorta. Conclusion This is the first study demonstrating the beneficial effects of chronic treatment with sildenafil on endothelial dysfunction and atherosclerosis in a model of spontaneous

  10. Structural and functional characterization of human apolipoprotein E 72-166 peptides in both aqueous and lipid environments

    Directory of Open Access Journals (Sweden)

    Chou Chi-Yuan

    2011-01-01

    Full Text Available Abstract Backgrounds There are three apolipoprotein E (apoE isoforms involved in human lipid homeostasis. In the present study, truncated apoE2-, apoE3- and apoE4-(72-166 peptides that are tailored to lack domain interactions are expressed and elucidated the structural and functional consequences. Methods & Results Circular dichroism analyses indicated that their secondary structure is still well organized. Analytical ultracentrifugation analyses demonstrated that apoE-(72-166 produces more complicated species in PBS. All three isoforms were significantly dissociated in the presence of dihexanoylphosphatidylcholine. Dimyristoylphosphatidylcholine turbidity clearance assay showed that apoE4-(72-166 maintains the highest lipid-binding capacity. Finally, only apoE4-(72-166 still maintained significant LDL receptor binding ability. Conclusions Overall, apoE4-(72-166 peptides displayed a higher lipid-binding and comparable receptor-binding ability as to full-length apoE. These findings provide the explanation of diverged functionality of truncated apoE isoforms.

  11. Epigenetic effectiveness of complete carcinogens: specific interactions of polycyclic aromatic hydrocarbons and aminoazo dyes with cholesterol and apolipoprotein A - I

    Energy Technology Data Exchange (ETDEWEB)

    Contag, B. [Technische Fachhochschule Berlin (Germany). Fachbereich II - Pharma- und Chemietechnik

    2005-10-01

    During a co-precipitation of cholesterol (Chol) and slight amounts of polycyclic aromatic hydrocarbons (PAHs) or aminoazo dyes (AZOs) in aqueous albumin solution, complex particles are formed; on their surfaces apolipoproteins with an amphipathic {alpha}-helix (e.g. apoA-I) are more or less firmly adsorbed. An efficacy index can be calculated from the strength of the hydrophobic interactions between apoA-I and the [Chol/PAH]- or [Chol/AZO]-complex, and the solubility of the PAH or AZO in an aqueous medium, which correlates to the carcinogenicity of these compounds. A short-term test for PAHs and AZOs is described, in which the efficacy index can be determined in the simplest manner without any great expenditure on equipment. The previous results suggest that the parent compounds of the PAHs and AZOs can be involved in a specific interaction with cholesterol-domains of the plasma membrane of a cell. The changes in membrane fluidity and architecture caused by these specific interactions could modulate the distribution and/or activity of membrane proteins which are critical to the regulation of cellular proliferation. (orig.)

  12. Small-molecule structure correctors target abnormal protein structure and function: structure corrector rescue of apolipoprotein E4-associated neuropathology.

    Science.gov (United States)

    Mahley, Robert W; Huang, Yadong

    2012-11-01

    An attractive strategy to treat proteinopathies (diseases caused by malformed or misfolded proteins) is to restore protein function by inducing proper three-dimensional structure. We hypothesized that this approach would be effective in reversing the detrimental effects of apolipoprotein (apo) E4, the major allele that significantly increases the risk of developing Alzheimer's disease and other neurodegenerative disorders. ApoE4's detrimental effects result from its altered protein conformation ("domain interaction"), making it highly susceptible to proteolytic cleavage and the generation of neurotoxic fragments. Here, we review apoE structure and function and how apoE4 causes neurotoxicity, and describe the identification of potent small-molecule-based "structure correctors" that induce proper apoE4 folding. SAR studies identified a series of small molecules that significantly reduced apoE4's neurotoxic effects in cultured neurons and a series that reduced apoE4 fragment levels in vivo, providing proof-of-concept for our approach. Structure-corrector-based therapies could prove to be highly effective for the treatment of many protein-misfolding diseases.

  13. Mutation in apolipoprotein B associated with hypobetalipoproteinemia despite decreased binding to the low density lipoprotein receptor

    DEFF Research Database (Denmark)

    Benn, Marianne; Nordestgaard, Børge G; Jensen, Jan Skov;

    2005-01-01

    Mutations in apolipoprotein B (APOB) may reduce binding of low density lipoprotein (LDL) to the LDL receptor and cause hypercholesterolemia. We showed that heterozygotes for a new mutation in APOB have hypobetalipoproteinemia, despite a reduced binding of LDL to the LDL receptor. APOB R3480P hete...

  14. Lipid, lipoprotein, and apolipoprotein profiles in active and sedentary men with tetraplegia

    NARCIS (Netherlands)

    Dallmeijer, A J; Hopman, M T; van der Woude, L H

    1997-01-01

    OBJECTIVE: To investigate whether the risk profile of coronary heart disease (CHD) is more favorable in physically active men with tetraplegia compared with sedentary men with tetraplegia. DESIGN: Using a cross-sectional design, the lipid and (apo)lipoprotein concentrations of 11 active and 13 seden

  15. Improving prediction of ischemic cardiovascular disease in the general population using apolipoprotein B

    DEFF Research Database (Denmark)

    Benn, Marianne; Nordestgaard, Børge G; Jensen, Gorm Boje

    2007-01-01

    Apolipoprotein B (apoB) levels predict fatal myocardial infarction. Whether apoB also predicts nonfatal ischemic cardiovascular events is unclear. We tested the following hypotheses: apoB predicts ischemic cardiovascular events, and apoB is a better predictor of ischemic cardiovascular events tha...

  16. Plasma apolipoprotein M is reduced in metabolic syndrome but does not predict intima media thickness

    DEFF Research Database (Denmark)

    Dullaart, Robin P F; Plomgaard, Peter; de Vries, Rindert

    2009-01-01

    BACKGROUND: Apolipoprotein (apo) M may exert anti-atherogenic properties in experimental studies. Its hepatic gene expression may be linked to glucose and lipid metabolism. Plasma apoM is decreased in obese mouse models. We hypothesized that plasma apoM is lower in metabolic syndrome (Met...

  17. Human apolipoprotein C-I expression in mice impairs learning and memory functions

    NARCIS (Netherlands)

    Abildayeva, Karlygash; Berbee, Jimmy F. P.; Blokland, Arjan; Jansen, Paula J.; Hoek, Frans J.; Meijer, Onno; Luetjohann, Dieter; Gautier, Thomas; Pillot, Thierry; De Vente, Jan; Havekes, Louis M.; Ramaekers, Frans C. S.; Kuipers, Folkert; Rensen, Patrick C. N.; Mulder, Monique

    2008-01-01

    The H2 allele of APOC I, giving rise to increased gene expression of apolipoprotein C-I (apoC-I), is in genetic disequilibrium with the APOE4 allele and may provide a major risk factor for Alzheimer's disease (AD). We found that apoC-I protein is present in astrocytes and endothelial cells within hi

  18. Screening for apolipoprotein E gene mutations in 4 patients with lipoprotein glomerulopathy

    Institute of Scientific and Technical Information of China (English)

    潘永利

    2006-01-01

    Objective To study the mutations of apolipoprotein E (apoE) gene in 4 Chinese lipoprotein glomerulopathy (LPG) patients and their family members, and to investigate the pathogenesis of LPG. Methods Urinalysis was performed on the family members of two patients, and they were screened for the level of serum creatinine, serum lipid and serum lipoprotein. The mutation of apoE

  19. Cinnamon Extract Improves TNF-a Induced Overproduction of Intestinal ApolipoproteinB-48 Lipoproteins

    Science.gov (United States)

    TNF-alpha stimulates the overproduction of intestinal apolipoproteins. We evaluated whether a water extract of cinnamon (Cinnulin PF®) improved the dyslipidemia induced by TNF-alpha in Triton WR-1339 treated hamsters, and whether Cinnulin PF® inhibits the TNF-alpha-induced over the secretion of apoB...

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  1. Capillary electrophoresis with laser-induced fluorescence detection for fast and reliable apolipoprotein E genotyping

    NARCIS (Netherlands)

    Somsen, GW; Welten, HTME; Mulder, FP; Swart, CW; Kema, IP; de Jong, GJ

    2002-01-01

    The use of capillary electrophoresis (CE) with laser-induced fluorescence (LIF) detection for the rapid determination of apolipoprotein E (apoE) genotypes was studied. High resolution and sensitive detection of the concerned DNA restriction fragments was achieved using CE buffers with hydroxypropylm

  2. Transcriptional Activation of Apolipoprotein CIII Expression by Glucose May Contribute to Diabetic Dyslipidemia

    NARCIS (Netherlands)

    Caron, Sandrine; Verrijken, An; Mertens, Ilse; Samanez, Carolina Huaman; Mautino, Gisele; Haas, Joel T.; Duran-Sandoval, Daniel; Prawitt, Janne; Francque, Sven; Vallez, Emmanuelle; Muhr-Tailleux, Anne; Berard, Isabelle; Kuipers, Folkert; Kuivenhoven, Jan A.; Biddinger, Sudha B.; Taskinen, Marja-Riitta; Van Gaal, Luc; Staels, Bart

    2011-01-01

    Objective-Hypertriglyceridemia and fatty liver are common in patients with type 2 diabetes, but the factors connecting alterations in glucose metabolism with plasma and liver lipid metabolism remain unclear. Apolipoprotein CIII (apoCIII), a regulator of hepatic and plasma triglyceride metabolism, is

  3. APOLIPOPROTEIN E GENE POLYMORPHISMS ARE NOT ASSOCIATED WITH DIABETIC RETINOPATHY: THE ATHEROSCLEROSIS RISK IN COMMUNITIES STUDY

    Science.gov (United States)

    PURPOSE: Polymorphism of the apolipoprotein E (APOE) gene has been associated with dyslipidemia and cardiovascular disease. This study examines the association of APOE polymorphisms and diabetic retinopathy. DESIGN: Population-based cross-sectional study. METHODS: We studied 1,398 people aged 49 to ...

  4. LNA-enhanced detection of single nucleotide polymorphisms in the apolipoprotein E

    DEFF Research Database (Denmark)

    Jacobsen, Nana; Bentzen, Joan; Meldgaard, Michael;

    2002-01-01

    Genotyping of single nucleotide polymorphisms (SNPs) in large populations presents a great challenge, especially if the SNPs are embedded in GC-rich regions, such as the codon 112 SNP in the human apolipoprotein E (apoE). In the present study, we have used immobilized locked nucleic acid (LNA) ca...

  5. Apolipoprotein E genotype and association between smoking and early onset Alzheimer's disease.

    NARCIS (Netherlands)

    C.M. van Duijn (Cock); P. de Knijff (Peter); M. Cruts (Marc); A. Wehnert (Anita); L.M. Havekes; C. van Broeckhoven (Christine); A. Hofman (Albert)

    1995-01-01

    textabstractOBJECTIVE--To investigate the hypothesis that differential survival between smokers and non-smokers leading to a decrease in the frequency of the e4 allele of the apolipoprotein E gene may explain the inverse relation between smoking history and early onset Alzheimer's disease. DESIGN--A

  6. Endotoxin contamination of apolipoprotein A-I: effect on macrophage proliferation--a cautionary tale.

    Science.gov (United States)

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

    2015-05-01

    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.

  7. Plasma apolipoprotein M is reduced in metabolic syndrome but does not predict intima media thickness

    NARCIS (Netherlands)

    Dullaart, Robin P. F.; Plomgaard, Peter; de Vries, Rindert; Dahlback, Bjorn; Nielsen, Lars B.

    2009-01-01

    Background: Apolipoprotein (apo) M may exert anti-atherogenic properties in experimental studies. Its hepatic gene expression may be linked to glucose and lipid metabolism. Plasma apoM is decreased in obese mouse models. We hypothesized that plasma apoM is lower in metabolic syndrome (MetS) subjects

  8. Expression of apolipoprotein B in the kidney attenuates renal lipid accumulation

    DEFF Research Database (Denmark)

    Krzystanek, Marcin; Pedersen, Tanja Xenia; Bartels, Emil Daniel

    2010-01-01

    The ability to produce apolipoprotein (apo) B-containing lipoproteins enables hepatocytes, enterocytes, and cardiomyocytes to export triglycerides. In this study, we examined secretion of apoB-containing lipoproteins from mouse kidney and its putative impact on triglyceride accumulation in the tu...... biological effect may be to dampen excess storage of triglycerides in proximal tubule cells....

  9. Genotypes and phenotypes for apolipoprotein E and Alzheimer disease in the Honolulu-Asia aging study

    NARCIS (Netherlands)

    J.W.P.F. Kardaun (Jan); L. White (Lon); H.E. Resnick; H. Petrovitch; S.M. Marcovina; A.M. Saunders (Ann); D.J. Foley (Dan); R.J. Havlik

    2000-01-01

    textabstractBACKGROUND: The utility of apolipoprotein E (ApoE) type as an indicator of genetic susceptibility to Alzheimer disease (AD) depends on the reliability of typing. Although ApoE protein isoform phenotyping is generally assumed equivalent to genotyping from DNA

  10. Apolipoprotein E genotype predicts 24-month Bayley scales infant development score

    NARCIS (Netherlands)

    Wright, RO; Hu, H; Silverman, EK; Tsaih, SW; Schwartz, J; Bellinger, D; Palazuelos, E; Weiss, ST; Hernandez-Avila, M

    2003-01-01

    Apolipoprotein E (APOE) regulates cholesterol and fatty acid metabolism, and may mediate synaptogenesis during neurodevelopment. To our knowledge, the effects of APOE4 isoforms on infant development have not been studied. This study was nested within a cohort of mother-infant pairs living in and aro

  11. A case-control study of apolipoprotein E genotypes in Alzheimer's disease associated with Down syndrome.

    NARCIS (Netherlands)

    H.M. Evenhuis (Heleen); C.M. van Duijn (Cock); W.A. van Gool (Willem)

    1995-01-01

    textabstractThe prevalence of clinical signs and neuropathological findings of Alzheimer's disease (AD) is high in Down's syndrome (DS). In the general population, the apolipoprotein E (ApoE) epsilon 4 isoform is an important risk for AD. We studied the allelic frequencies of ApoE in 26 DS cases ful

  12. The impact of apolipoprotein E on dementia in persons with Down's syndrome.

    NARCIS (Netherlands)

    Coppus, A.M.; Evenhuis, H.M.; Verberne, G.J.; Visser, F.E.; Arias-Vasquez, A.; Sayed-Tabatabaei, F.A.; Vergeer-Drop, J.; Eikelenboom, P.; Gool, W.A. van; Duijn, C.M. van

    2008-01-01

    Apolipoprotein E (APOE) is consistently associated with dementia in the general population. Findings on the role of this gene in persons with Down's syndrome (DS) are inconclusive. We studied the effects of APOE on mortality and dementia in a longitudinal prospective study of a large population-base

  13. Human apolipoprotein C-I expression in mice impairs learning and memory functions

    NARCIS (Netherlands)

    Abildayeva, K.; Berbée, J.F.P.; Blokland, A.; Jansen, P.J.; Hoek, F.J.; Meijer, O.; Lütjohann, D.; Gautier, T.; Pillot, T.; Vente, J.de; Havekes, L.M.; Ramaekers, F.C.S.; Kuipers, F.; Rensen, P.C.N.; Mulder, M.

    2008-01-01

    The H2 allele of APOC1, giving rise to increased gene expression of apolipoprotein C-I (apoC-I), is in genetic disequilibrium with the APOE4 allele and may provide a major risk factor for Alzheimer's disease (AD). We found that apoC-I protein is present in astrocytes and endothelial cells within hip

  14. Fasting and post-prandial apolipoprotein B-48 levels in healthy, obese, and hyperlipidemic subjects

    Science.gov (United States)

    Apolipoprotein (apo) B-48 is the only specific marker of intestinal lipoproteins. We evaluated a novel enzyme-linked immunosorbent assay (ELISA) standardized with recombinant apo B-48 to measure apo B-48 in plasma and triglyceride-rich lipoproteins (TRLs, density b1.006 g/mL). Coefficients of variat...

  15. Effects of fenofibrate on hyperlipidemia and postprandial triglyceride metabolism in human apolipoprotein C1 transgenic mice

    NARCIS (Netherlands)

    Jong, M.C.; Dahlmans, V.E.H.; Princen, H.M.G.; Hofker, M.H.; Havekes, L.M.

    1998-01-01

    To study the in vivo role of apolipoprotein (apo) C1 in lipoprotein metabolism, we have generated transgenic mice expressing the human apo C1 gene. Apo C1 is a small 6.6 kDa protein that is primarily synthesized by the liver and is present on chylomicrons, very low density lipoproteins (VLDL) and hi

  16. Development of atopic dermatitis in mice transgenic for human apolipoprotein C1

    NARCIS (Netherlands)

    Nagelkerken, L.; Verzaal, P.; Lagerweij, T.; Persoon-Deen, C.; Berbee, J.F.P.; Prens, E.P.; Havekes, L.M.; Oranje, A.P.

    2008-01-01

    Mice with transgenic expression of human apolipoprotein C1 (APOC1) in liver and skin have strongly increased serum levels of cholesterol, triglycerides, and free fatty acids, indicative of a disturbed lipid metabolism. Importantly, these mice display a disturbed skin barrier function, evident from i

  17. Trimerization of apolipoprotein A-I retards plasma clearance and preserves antiatherosclerotic properties

    DEFF Research Database (Denmark)

    Graversen, Jonas Heilskov; Laurberg, Jacob Marsvin; Andersen, Mikkel Holmen

    2008-01-01

    An increased plasma level of the major high-density lipoprotein (HDL) component, apolipoprotein A-I (apoA-I) is the aim of several therapeutic strategies for combating atherosclerotic disease. HDL therapy by direct intravenous administration of apoA-I is a plausible way; however, a fast renal...

  18. Apolipoprotein A5 and lipoprotein lipase interact to modulate anthropometric measures in Hispanics of Caribbean origin

    Science.gov (United States)

    Apolipoprotein A5 (APOA5) and lipoprotein lipase (LPL) proteins interact functionally to regulate lipid metabolism, and single nucleotide polymorphisms (SNPs) for each gene have also been associated independently with obesity risk. Evaluating gene combinations may be more effective than single SNP a...

  19. Learning Derived Predicate Rules for Planning Domains under Partial Observability%在部分观测环境下学习规划领域的派生谓词规则

    Institute of Scientific and Technical Information of China (English)

    饶东宁; 蒋志华; 姜云飞; 邓玉辉

    2015-01-01

    文中提出了一种在部分观测环境下学习规划领域的派生谓词规则的方法。在规划领域描述语言(PDDL)中,派生谓词用来描述动作的非直接效果,是规划领域模型和搜索控制知识的重要组成部分。然而,对于大多数规划领域而言,从无到有地构造派生谓词规则是不容易的。因此,研究自动获取派生谓词的推导规则是有意义的。已有研究工作提出通过修订一个初始的不完备的领域理论来获取推导规则的方法,但是它们的主要缺点在于待学习谓词的训练例的数量非常少,这是因为训练例按照非常有限的方式来生成。而更本质的原因在于它们假设环境是不可观测的。其实,在现实生活中很多动作的非直接效果是可以观测的,或者通过简单的目测或者通过专门的工具。因此文中提出增加观测来反映动作的非直接效果,以便增加待学习谓词的训练例数目从而改善学习的精准度。此外,为了补充一些在归纳学习过程中学习不到的谓词,文中还提出了一个后处理方法来使得学习到的规则在语义上更完整。通过在派生谓词基准领域上的实验表明,文中所提出的方法是可行有效的。更深远的意义在于,文中的研究工作有利于规划领域的自动建模或者控制知识的自动获取的研究与实现。%This paper presents a method to learn derived predicate rules for planning domains under partial observability.In the PDDL (Planning Domain Description Language),derived predicates are a compact way to describe indirect effects of actions,and an important part of planning domain models or search control knowledge.However,for most planning domains,it is not easy to write derived predicate rules from scratch,even for experts.Therefore,it is worthy of studying how to automatically acquire rules for derived predicates from observed plans.There has been some research

  20. Plasma proteome changes in cardiovascular disease patients: novel isoforms of apolipoprotein A1

    Directory of Open Access Journals (Sweden)

    Oravec Milan

    2011-06-01

    Full Text Available Abstract Background The aim of this proteomic study was to look for changes taking place in plasma proteomes of patients with acute myocardial infarction (AMI, unstable angina pectoris (UAP, and stable angina pectoris (SAP. Methods Depleted plasma proteins were separated by 2D SDS-PAGE (pI 4-7, and proteomes were compared using Progenesis SameSpots statistical software. Proteins were identified by nanoLC-MS/MS. Proteins were quantified using commercial kits. Apolipoprotein A1 was studied using 1D and 2D SDS-PAGE, together with western blotting. Results Reciprocal comparison revealed 46 unique, significantly different spots; proteins in 34 spots were successfully identified and corresponded to 38 different proteins. Discrete comparisons of patient groups showed 45, 41, and 8 significantly different spots when AMI, UAP, and SAP were compared with the control group. On the basis of our proteomic data, plasma levels of two of them, alpha-1 microglobulin and vitamin D-binding protein, were determined. The data, however, failed to prove the proteins to be suitable markers or risk factors in the studied groups. The plasma level and isoform representation of apolipoprotein A1 were also estimated. Using 1D and 2D SDS-PAGE, together with western blotting, we observed extra high-molecular weight apolipoprotein A1 fractions presented only in the patient groups, indicating that the novel high-molecular weight isoforms of apolipoprotein A1 may be potential new markers or possible risk factors of cardiovascular disease. Conclusion The reported data show plasma proteome changes in patients with AMI, UAP, and SAP. We propose some apolipoprotein A1 fractions as a possible new disease-associated marker of cardiovascular disorders.

  1. Apolipoprotein E (APOE) genotype has dissociable effects on memory and attentional–executive network function in Alzheimer’s disease

    Science.gov (United States)

    Wolk, David A.; Dickerson, Bradford C.; Weiner, Michael; Aiello, Marilyn; Aisen, Paul; Albert, Marilyn S.; Alexander, Gene; Anderson, Heather S.; Anderson, Karen; Apostolova, Liana; Arnold, Steve; Ashford, Wes; Assaly, Michele; Asthana, Sanjay; Bandy, Dan; Bartha, Rob; Bates, Vernice; Beckett, Laurel; Bell, Karen L.; Benincasa, Amanda L.; Bergman, Howard; Bernick, Charles; Bernstein, Matthew; Black, Sandra; Blank, Karen; Borrie, Michael; Brand, Connie; Brewer, James; Brown, Alice D.; Burns, Jeffrey M.; Cairns, Nigel J.; Caldwell, Curtis; Capote, Horacio; Carlsson, Cynthia M.; Carmichael, Owen; Cellar, Janet S.; Celmins, Dzintra; Chen, Kewei; Chertkow, Howard; Chowdhury, Munir; Clark, David; Connor, Donald; Correia, Stephen; Crawford, Karen; Dale, Anders; de Leon, Mony J; De Santi, Susan M; DeCarli, Charles; deToledo-Morrell, Leyla; DeVous, Michael; Diaz-Arrastia, Ramon; Dolen, Sara; Donohue, Michael; Doody, Rachelle S.; Doraiswamy, P. Murali; Duara, Ranjan; Englert, Jessica; Farlow, Martin; Feldman, Howard; Felmlee, Joel; Fleisher, Adam; Fletcher, Evan; Foroud, Tatiana M.; Foster, Norm; Fox, Nick; Frank, Richard; Gamst, Anthony; Given, Curtis A.; Graff-Radford, Neill R; Green, Robert C.; Griffith, Randall; Grossman, Hillel; Hake, Ann M.; Hardy, Peter; Harvey, Danielle; Heidebrink, Judith L.; Hendin, Barry A.; Herring, Scott; Honig, Lawrence S.; Hosein, Chris; Robin Hsiung, Ging-Yuek; Hudson, Leon; Ismail, M. Saleem; Jack, Clifford R.; Jacobson, Sandra; Jagust, William; Jayam-Trouth, Annapurni; Johnson, Kris; Johnson, Heather; Johnson, Nancy; Johnson, Kathleen; Johnson, Keith A.; Johnson, Sterling; Kachaturian, Zaven; Karlawish, Jason H.; Kataki, Maria; Kaye, Jeffrey; Kertesz, Andrew; Killiany, Ronald; Kittur, Smita; Koeppe, Robert A.; Korecka, Magdalena; Kornak, John; Kozauer, Nicholas; Lah, James J.; Laubinger, Mary M.; Lee, Virginia M.-Y.; Lee, T.-Y.; Lerner, Alan; Levey, Allan I.; Longmire, Crystal Flynn; Lopez, Oscar L.; Lord, Joanne L.; Lu, Po H.; MacAvoy, Martha G.; Malloy, Paul; Marson, Daniel; Martin-Cook, Kristen; Martinez, Walter; Marzloff, George; Mathis, Chet; Mc-Adams-Ortiz, Catherine; Mesulam, Marsel; Miller, Bruce L.; Mintun, Mark A.; Mintzer, Jacobo; Molchan, Susan; Montine, Tom; Morris, John; Mulnard, Ruth A.; Munic, Donna; Nair, Anil; Neu, Scott; Nguyen, Dana; Norbash, Alexander; Oakley, MaryAnn; Obisesan, Thomas O.; Ogrocki, Paula; Ott, Brian R.; Parfitt, Francine; Pawluczyk, Sonia; Pearlson, Godfrey; Petersen, Ronald; Petrella, Jeffrey R.; Potkin, Steven; Potter, William Z.; Preda, Adrian; Quinn, Joseph; Rainka, Michelle; Reeder, Stephanie; Reiman, Eric M.; Rentz, Dorene M.; Reynolds, Brigid; Richard, Jennifer; Roberts, Peggy; Rogers, John; Rosen, Allyson; Rosen, Howard J.; Rusinek, Henry; Sabbagh, Marwan; Sadowsky, Carl; Salloway, Stephen; Santulli, Robert B.; Saykin, Andrew J.; Scharre, Douglas W.; Schneider, Lon; Schneider, Stacy; Schuff, Norbert; Shah, Raj C.; Shaw, Les; Shen, Li; Silverman, Daniel H.S.; Simpson, Donna M.; Sink, Kaycee M.; Smith, Charles D.; Snyder, Peter J.; Spann, Bryan M.; Sperling, Reisa A.; Spicer, Kenneth; Stefanovic, Bojana; Stern, Yaakov; Stopa, Edward; Tang, Cheuk; Tariot, Pierre; Taylor-Reinwald, Lisa; Thai, Gaby; Thomas, Ronald G.; Thompson, Paul; Tinklenberg, Jared; Toga, Arthur W.; Tremont, Geoffrey; Trojanowki, J.Q.; Trost, Dick; Turner, Raymond Scott; van Dyck, Christopher H.; Vanderswag, Helen; Varon, Daniel; Villanueva-Meyer, Javier; Villena, Teresa; Walter, Sarah; Wang, Paul; Watkins, Franklin; Weiner, Michael; Williamson, Jeff D.; Wolk, David; Wu, Chuang-Kuo; Zerrate, Maria; Zimmerman., Earl A.

    2010-01-01

    The ε4 allele of the apolipoprotein E (APOE) gene is the major genetic risk factor for Alzheimer’s disease (AD), but limited work has suggested that APOE genotype may modulate disease phenotype. Carriers of the ε4 allele have been reported to have greater medial temporal lobe (MTL) pathology and poorer memory than noncarriers. Less attention has focused on whether there are domains of cognition and neuroanatomical regions more affected in noncarriers. Further, a major potential confound of prior in vivo studies is the possibility of different rates of clinical misdiagnosis for carriers vs. noncarriers. We compared phenotypic differences in cognition and topography of regional cortical atrophy of ε4 carriers (n = 67) vs. noncarriers (n = 24) with mild AD from the Alzheimer’s Disease Neuroimaging Initiative, restricted to those with a cerebrospinal fluid (CSF) molecular profile consistent with AD. Between-group comparisons were made for psychometric tests and morphometric measures of cortical thickness and hippocampal volume. Carriers displayed significantly greater impairment on measures of memory retention, whereas noncarriers were more impaired on tests of working memory, executive control, and lexical access. Consistent with this cognitive dissociation, carriers exhibited greater MTL atrophy, whereas noncarriers had greater frontoparietal atrophy. Performance deficits in particular cognitive domains were associated with disproportionate regional brain atrophy within nodes of cortical networks thought to subserve these cognitive processes. These convergent cognitive and neuroanatomic findings in individuals with a CSF molecular profile consistent with AD support the hypothesis that APOE genotype modulates the clinical phenotype of AD through influence on specific large-scale brain networks. PMID:20479234

  2. Domain crossing

    DEFF Research Database (Denmark)

    Schraefel, M. C.; Rouncefield, Mark; Kellogg, Wendy

    2012-01-01

    In CSCW, how much do we need to know about another domain/culture before we observe, intersect and intervene with designs. What optimally would that other culture need to know about us? Is this a “how long is a piece of string” question, or an inquiry where we can consider a variety of contexts a...

  3. Apolipoprotein E isoform-dependent dendritic recovery of hippocampal neurons following activation of innate immunity

    Directory of Open Access Journals (Sweden)

    Maezawa Izumi

    2006-08-01

    Full Text Available Abstract Background Innate immune activation, including a role for cluster of differentiation 14/toll-like receptor 4 co-receptors (CD14/TLR-4 co-receptors, has been implicated in paracrine damage to neurons in several neurodegenerative diseases that also display stratification of risk or clinical outcome with the common alleles of the apolipoprotein E gene (APOE: APOE2, APOE3, and APOE4. Previously, we have shown that specific stimulation of CD14/TLR-4 with lipopolysaccharide (LPS leads to greatest innate immune response by primary microglial cultures from targeted replacement (TR APOE4 mice and greatest p38MAPK-dependent paracrine damage to neurons in mixed primary cultures and hippocampal slice cultures derived from TR APOE4 mice. In contrast, TR APOE2 astrocytes had the highest NF-kappaB activity and no neurotoxicity. Here we tested the hypothesis that direct activation of CD14/TLR-4 in vivo would yield different amounts of paracrine damage to hippocampal sector CA1 pyramidal neurons in TR APOE mice. Methods We measured in vivo changes in dendrite length in hippocampal CA1 neurons using Golgi staining and determined hippocampal apoE levels by Western blot. Neurite outgrowth of cultured primary neurons in response to astrocyte conditioned medium was assessed by measuring neuron length and branch number. Results Our results showed that TR APOE4 mice had slightly but significantly shorter dendrites at 6 weeks of age. Following exposure to intracerebroventricular LPS, there was comparable loss of dendrite length at 24 hr among the three TR APOE mice. Recovery of dendrite length over the next 48 hr was greater in TR APOE2 than TR APOE3 mice, while TR APOE4 mice had failure of dendrite regeneration. Cell culture experiments indicated that the enhanced neurotrophic effect of TR APOE2 was LDL related protein-dependent. Conclusion The data indicate that the environment within TR APOE2 mouse hippocampus was most supportive of dendrite regeneration

  4. Amphipathic α-Helices in Apolipoproteins Are Crucial to the Formation of Infectious Hepatitis C Virus Particles

    Science.gov (United States)

    Nakamura, Shota; Ono, Chikako; Shiokawa, Mai; Yamamoto, Satomi; Motomura, Takashi; Okamoto, Toru; Okuzaki, Daisuke; Yamamoto, Masahiro; Saito, Izumu; Wakita, Takaji; Koike, Kazuhiko; Matsuura, Yoshiharu

    2014-01-01

    Apolipoprotein B (ApoB) and ApoE have been shown to participate in the particle formation and the tissue tropism of hepatitis C virus (HCV), but their precise roles remain uncertain. Here we show that amphipathic α-helices in the apolipoproteins participate in the HCV particle formation by using zinc finger nucleases-mediated apolipoprotein B (ApoB) and/or ApoE gene knockout Huh7 cells. Although Huh7 cells deficient in either ApoB or ApoE gene exhibited slight reduction of particles formation, knockout of both ApoB and ApoE genes in Huh7 (DKO) cells severely impaired the formation of infectious HCV particles, suggesting that ApoB and ApoE have redundant roles in the formation of infectious HCV particles. cDNA microarray analyses revealed that ApoB and ApoE are dominantly expressed in Huh7 cells, in contrast to the high level expression of all of the exchangeable apolipoproteins, including ApoA1, ApoA2, ApoC1, ApoC2 and ApoC3 in human liver tissues. The exogenous expression of not only ApoE, but also other exchangeable apolipoproteins rescued the infectious particle formation of HCV in DKO cells. In addition, expression of these apolipoproteins facilitated the formation of infectious particles of genotype 1b and 3a chimeric viruses. Furthermore, expression of amphipathic α-helices in the exchangeable apolipoproteins facilitated the particle formation in DKO cells through an interaction with viral particles. These results suggest that amphipathic α-helices in the exchangeable apolipoproteins play crucial roles in the infectious particle formation of HCV and provide clues to the understanding of life cycle of HCV and the development of novel anti-HCV therapeutics targeting for viral assembly. PMID:25502789

  5. Amphipathic α-helices in apolipoproteins are crucial to the formation of infectious hepatitis C virus particles.

    Directory of Open Access Journals (Sweden)

    Takasuke Fukuhara

    2014-12-01

    Full Text Available Apolipoprotein B (ApoB and ApoE have been shown to participate in the particle formation and the tissue tropism of hepatitis C virus (HCV, but their precise roles remain uncertain. Here we show that amphipathic α-helices in the apolipoproteins participate in the HCV particle formation by using zinc finger nucleases-mediated apolipoprotein B (ApoB and/or ApoE gene knockout Huh7 cells. Although Huh7 cells deficient in either ApoB or ApoE gene exhibited slight reduction of particles formation, knockout of both ApoB and ApoE genes in Huh7 (DKO cells severely impaired the formation of infectious HCV particles, suggesting that ApoB and ApoE have redundant roles in the formation of infectious HCV particles. cDNA microarray analyses revealed that ApoB and ApoE are dominantly expressed in Huh7 cells, in contrast to the high level expression of all of the exchangeable apolipoproteins, including ApoA1, ApoA2, ApoC1, ApoC2 and ApoC3 in human liver tissues. The exogenous expression of not only ApoE, but also other exchangeable apolipoproteins rescued the infectious particle formation of HCV in DKO cells. In addition, expression of these apolipoproteins facilitated the formation of infectious particles of genotype 1b and 3a chimeric viruses. Furthermore, expression of amphipathic α-helices in the exchangeable apolipoproteins facilitated the particle formation in DKO cells through an interaction with viral particles. These results suggest that amphipathic α-helices in the exchangeable apolipoproteins play crucial roles in the infectious particle formation of HCV and provide clues to the understanding of life cycle of HCV and the development of novel anti-HCV therapeutics targeting for viral assembly.

  6. Genetically elevated apolipoprotein A-I, high-density lipoprotein cholesterol levels, and risk of ischemic heart disease

    DEFF Research Database (Denmark)

    Lundegaard, Christiane; Tybjærg-Hansen, Anne; Grande, Peer

    2010-01-01

    Epidemiologically, levels of high-density lipoprotein (HDL) cholesterol and its major protein constituent, apolipoprotein A-I (apoA-I), are inversely related to risk of ischemic heart disease (IHD).......Epidemiologically, levels of high-density lipoprotein (HDL) cholesterol and its major protein constituent, apolipoprotein A-I (apoA-I), are inversely related to risk of ischemic heart disease (IHD)....

  7. Acrolein modification impairs key functional features of rat apolipoprotein E: identification of modified sites by mass spectrometry.

    Science.gov (United States)

    Tran, Tuyen N; Kosaraju, Malathi G; Tamamizu-Kato, Shiori; Akintunde, Olayemi; Zheng, Ying; Bielicki, John K; Pinkerton, Kent; Uchida, Koji; Lee, Yuan Yu; Narayanaswami, Vasanthy

    2014-01-21

    Apolipoprotein E (apoE), an antiatherogenic apolipoprotein, plays a significant role in the metabolism of lipoproteins. It lowers plasma lipid levels by acting as a ligand for the low-density lipoprotein receptor (LDLr) family of proteins, in addition to playing a role in promoting macrophage cholesterol efflux in atherosclerotic lesions. The objective of this study is to examine the effect of acrolein modification on the structure and function of rat apoE and to determine the sites and nature of modification by mass spectrometry. Acrolein is a highly reactive aldehyde, which is generated endogenously as one of the products of lipid peroxidation and is present in the environment in pollutants such as tobacco smoke and heated oils. In initial studies, acrolein-modified apoE was identified by immunoprecipitation using an acrolein-lysine specific antibody in the plasma of 10-week old male rats that were exposed to filtered air (FA) or low doses of environmental tobacco smoke (ETS). While both groups displayed acrolein-modified apoE in the lipoprotein fraction, the ETS group had higher levels in the lipid-free fraction compared with the FA group. This observation provided the rationale to further investigate the effect of acrolein modification on rat apoE at a molecular level. Treatment of recombinant rat apoE with a 10-fold molar excess of acrolein resulted in (i) a significant decrease in lipid-binding and cholesterol efflux abilities, (ii) impairment in the LDLr- and heparin-binding capabilities, and (iii) significant alterations in the overall stability of the protein. The disruption in the functional abilities is attributed directly or indirectly to acrolein modification yielding an aldimine adduct at K149 and K155 (+38); a propanal adduct at K135 and K138 (+56); an N(ε)-(3-methylpyridinium)lysine (MP-lysine) at K64, K67, and K254 (+76), and an N(ε)-(3-formyl-3,4-dehydropiperidino)lysine (FDP-lysine) derivative at position K68 (+94), as determined by matrix

  8. Single-domain antibodies for biomedical applications.

    Science.gov (United States)

    Krah, Simon; Schröter, Christian; Zielonka, Stefan; Empting, Martin; Valldorf, Bernhard; Kolmar, Harald

    2016-01-01

    Single-domain antibodies are the smallest antigen-binding units of antibodies, consisting either only of one variable domain or one engineered constant domain that solely facilitates target binding. This class of antibody derivatives comprises naturally occurring variable domains derived from camelids and sharks as well as engineered human variable or constant antibody domains of the heavy or light chain. Because of their high affinity and specificity as well as stability, small size and benefit of multiple re-formatting opportunities, those molecules emerged as promising candidates for biomedical applications and some of these entities have already proven to be successful in clinical development.

  9. An ABCA1-independent pathway for recycling a poorly lipidated 8.1 nm apolipoprotein E particle from glia

    Science.gov (United States)

    Fan, Jianjia; Stukas, Sophie; Wong, Charmaine; Chan, Jennifer; May, Sharon; DeValle, Nicole; Hirsch-Reinshagen, Veronica; Wilkinson, Anna; Oda, Michael N.; Wellington, Cheryl L.

    2011-01-01

    Lipid transport in the brain is coordinated by glial-derived lipoproteins that contain apolipoprotein E (apoE) as their primary protein. Here we show that apoE is secreted from wild-type (WT) primary murine mixed glia as nascent lipoprotein subspecies ranging from 7.5 to 17 nm in diameter. Negative-staining electron microscropy (EM) revealed rouleaux, suggesting a discoidal structure. Potassium bromide (KBr) density gradient ultracentrifugation showed that all subspecies, except an 8.1 nm particle, were lipidated. Glia lacking the cholesterol transporter ABCA1 secreted only 8.1 nm particles, which were poorly lipidated and nondiscoidal but could accept lipids to form the full repertoire of WT apoE particles. Receptor-associated-protein (RAP)-mediated inhibition of apoE receptor function blocked appearance of the 8.1 nm species, suggesting that this particle may arise through apoE recycling. Selective deletion of the LDL receptor (LDLR) reduced the level of 8.1 nm particle production by approximately 90%, suggesting that apoE is preferentially recycled through the LDLR. Finally, apoA-I stimulated secretion of 8.1 nm particles in a dose-dependent manner. These results suggest that nascent glial apoE lipoproteins are secreted through multiple pathways and that a greater understanding of these mechanisms may be relevant to several neurological disorders. PMID:21705806

  10. Accelerated pericyte degeneration and blood-brain barrier breakdown in apolipoprotein E4 carriers with Alzheimer's disease.

    Science.gov (United States)

    Halliday, Matthew R; Rege, Sanket V; Ma, Qingyi; Zhao, Zhen; Miller, Carol A; Winkler, Ethan A; Zlokovic, Berislav V

    2016-01-01

    The blood–brain barrier (BBB) limits the entry of neurotoxic blood-derived products and cells into the brain that is required for normal neuronal functioning and information processing. Pericytes maintain the integrity of the BBB and degenerate in Alzheimer’s disease (AD). The BBB is damaged in AD, particularly in individuals carrying apolipoprotein E4 (APOE4) gene, which is a major genetic risk factor for late-onset AD. The mechanisms underlying the BBB breakdown in AD remain, however, elusive. Here, we show accelerated pericyte degeneration in AD APOE4 carriers >AD APOE3 carriers >non-AD controls, which correlates with the magnitude of BBB breakdown to immunoglobulin G and fibrin. We also show accumulation of the proinflammatory cytokine cyclophilin A (CypA) and matrix metalloproteinase-9 (MMP-9) in pericytes and endothelial cells in AD (APOE4 >APOE3), previously shown to lead to BBB breakdown in transgenic APOE4 mice. The levels of the apoE lipoprotein receptor, low-density lipoprotein receptor-related protein-1 (LRP1), were similarly reduced in AD APOE4 and APOE3 carriers. Our data suggest that APOE4 leads to accelerated pericyte loss and enhanced activation of LRP1-dependent CypA–MMP-9 BBB-degrading pathway in pericytes and endothelial cells, which can mediate a greater BBB damage in AD APOE4 compared with AD APOE3 carriers.

  11. Trusted Domain

    DEFF Research Database (Denmark)

    Hjorth, Theis Solberg; Torbensen, Rune

    2012-01-01

    In the digital age of home automation and with the proliferation of mobile Internet access, the intelligent home and its devices should be accessible at any time from anywhere. There are many challenges such as security, privacy, ease of configuration, incompatible legacy devices, a wealth...... remote access via IP-based devices such as smartphones. The Trusted Domain platform fits existing legacy technologies by managing their interoperability and access controls, and it seeks to avoid the security issues of relying on third-party servers outside the home. It is a distributed system...... of wireless standards, limited resources of embedded systems, etc. Taking these challenges into account, we present a Trusted Domain home automation platform, which dynamically and securely connects heterogeneous networks of Short-Range Wireless devices via simple non-expert user. interactions, and allows...

  12. Further studies of the influence of apolipoprotein B alleles on glucose and lipid metabolism

    DEFF Research Database (Denmark)

    Bentzen, Joan; Poulsen, Pernille; Vaag, Allan;

    2003-01-01

    The effect of five genetic polymorphisms in the apolipoprotein B gene on parameters of lipid and glucose metabolism was assessed in 564 Danish mono- and dizygotic twins. Genotypes in apolipoprotein B T71I (ApaLI RFLP), A591V (AluI RFLP), L2712P (MvaI RFLP), R3611Q (MspI RFLP), and E4154K (Eco...... was seen in the dizygotic twins. The effect of the polymorphisms on lipid and glucose parameters could be mediated through linkage to genes with known effect on glucose metabolism or through free fatty acids exerting their effect on glucose metabolism.......RI RFLP) were established using polymerase chain reaction and restriction enzyme digests. The effect of genotypes on lipid levels and on glucose, insulin, and HOMA (i.e., calculated parameters of beta-cell function and insulin resistance) was assessed by multivariate analyses of variance correcting...

  13. Suppressive effects of cacao polyphenols on the development of atherosclerosis in apolipoprotein E-deficient mice.

    Science.gov (United States)

    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 cacao polyphenol group (p cacao polyphenols inhibit the development of atherosclerosis in apolipoprotein E-deficient (-/-) mice by reducing oxidative stress and inflammatory responses.

  14. Apolipoprotein M affecting lipid metabolism or just catching a ride with lipoproteins in the circulation?

    DEFF Research Database (Denmark)

    Dahlbäck, B; Nielsen, Lars Bo

    2009-01-01

    M retains its signal peptide, which serves as a hydrophobic anchor to the lipoproteins. This prevents apoM from being lost in the urine. Approximately 5% of HDL carries an apoM molecule. ApoM in plasma (1 microM) correlates strongly with both low-density lipoprotein (LDL) and HDL cholesterol, suggesting......Apolipoprotein M (apoM) is a novel apolipoprotein found mainly in high-density lipoproteins (HDL). Its function is yet to be defined. ApoM (25 kDa) has a typical lipocalin ss-barrel fold and a hydrophobic pocket. Retinoids bind apoM but with low affinity and may not be the natural ligands. Apo......; possible mechanisms include increased formation of pre-ss HDL, enhanced cholesterol mobilization from foam cells, and increased antioxidant properties....

  15. Further studies of the influence of apolipoprotein B alleles on glucose and lipid metabolism

    DEFF Research Database (Denmark)

    Bentzen, Joan; Poulsen, Pernille; Vaag, Allan

    2003-01-01

    The effect of five genetic polymorphisms in the apolipoprotein B gene on parameters of lipid and glucose metabolism was assessed in 564 Danish mono- and dizygotic twins. Genotypes in apolipoprotein B T71I (ApaLI RFLP), A591V (AluI RFLP), L2712P (MvaI RFLP), R3611Q (MspI RFLP), and E4154K (Eco...... on the insulin-to-glucose ratio (p = 0.04), and E4154K (EcoRI RFLP) influenced HOMAbeta (p = 0.04). Significant interactions were observed between genotype in T71I (ApaLI RFLP), A591V (AluI RFLP), R3611Q (MspI RFLP), and E4154K (EcoRI RFLP) and glucose tolerance on lipid-related parameters (0.03

  16. Domain Derivatives in Dielectric Rough Surface Scattering

    Science.gov (United States)

    2015-01-01

    non-grazing angle (|θinc| < π/2) by a beam (ψinc) of finite width, e.g., a beam with a Gaussian angular spectrum [40] or a tapered Thorsos beam [44...whose diagonal elements are L+ and L−, and let Ψ = [ψ+, ψ−]T , Ψ′ = [ψ+′, ψ−′]T , and let P = [p+, p−]T . Moreover, let [q]Γ denote the jump of the

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

    Science.gov (United States)

    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.

  18. Genetic vulnerability following traumatic brain injury: the role of apolipoprotein E

    OpenAIRE

    Nathoo, N; Chetty, R; van Dellen, J R; Barnett, G H

    2003-01-01

    Apolipoprotein E (APOE) is thought to be responsible for the transportation of lipids within the brain, maintaining structural integrity of the microtubule within the neurone, and assisting with neural transmission. Possession of the APOE ɛ4 allele has also been shown to influence neuropathological findings in patients who die from traumatic brain injury, including the accumulation of amyloid β protein. Previous clinical studies reporting varying outcome severities of traumatic brain injury, ...

  19. Apolipoprotein M binds oxidized phospholipids and increases the antioxidant effect of HDL

    DEFF Research Database (Denmark)

    Elsøe, Sara; Ahnström, Josefin; Christoffersen, Christina;

    2012-01-01

    Oxidation of LDL plays a key role in the development of atherosclerosis. HDL may, in part, protect against atherosclerosis by inhibiting LDL oxidation. Overexpression of HDL-associated apolipoprotein M (apoM) protects mice against atherosclerosis through a not yet clarified mechanism. Being...... a lipocalin, apoM contains a binding pocket for small lipophilic molecules. Here, we report that apoM likely serves as an antioxidant in HDL by binding oxidized phospholipids, thus enhancing the antioxidant potential of HDL....

  20. Cacao polyphenols influence the regulation of apolipoprotein in HepG2 and Caco2 cells.

    Science.gov (United States)

    Yasuda, Akiko; Natsume, Midori; Osakabe, Naomi; Kawahata, Keiko; Koga, Jinichiro

    2011-02-23

    Cocoa powder is rich in polyphenols, such as catechins and procyanidins, and has been shown to inhibit low-density lipoprotein (LDL) oxidation and atherogenesis in a variety of models. Human studies have also shown daily intake of cocoa increases plasma high-density lipoprotein (HDL) and decreases LDL levels. However, the mechanisms responsible for these effects of cocoa on cholesterol metabolism have yet to be fully elucidated. The present study investigated the effects of cacao polyphenols on the production of apolipoproteins A1 and B in human hepatoma HepG2 and intestinal Caco2 cell lines. The cultured HepG2 cells or Caco2 cells were incubated for 24 h in the presence of cacao polyphenols such as (-)-epicatechin, (+)-catechin, procyanidin B2, procyanidin C1, and cinnamtannin A2. The concentration of apolipoproteins in the cell culture media was quantified using an enzyme-linked immunoassay, and the mRNA expression was quantified by RT-PCR. Cacao polyphenols increased apolipoprotein A1 protein levels and mRNA expression, even though apolipoprotein B protein and the mRNA expression were slightly decreased in both HepG2 cells and Caco2 cells. In addition, cacao polyphenols increased sterol regulatory element binding proteins (SREBPs) and activated LDL receptors in HepG2 cells. These results suggest that cacao polyphenols may increase the production of mature form SREBPs and LDL receptor activity, thereby increasing ApoA1 and decreasing ApoB levels. These results elucidate a novel mechanism by which HDL cholesterol levels become elevated with daily cocoa intake.

  1. CHRNA7 Polymorphisms and Dementia Risk: Interactions with Apolipoprotein ε4 and Cigarette Smoking

    OpenAIRE

    2016-01-01

    α7 nicotinic acetylcholine receptor (α7nAChR, encoded by CHRNA7) is involved in dementia pathogenesis through cholinergic neurotransmission, neuroprotection and interactions with amyloid-β. Smoking promotes atherosclerosis and increases dementia risk, but nicotine exerts neuroprotective effect via α7nAChR in preclinical studies. No studies explored the gene-gene, gene-environment interactions between CHRNA7 polymorphism, apolipoprotein E (APOE) ε4 status and smoking on dementia risk. This cas...

  2. Defining Domain Language of Graphical User Interfaces

    OpenAIRE

    Baciková, Michaela; PORUBÄN Jaroslav; Lakatos, Dominik

    2013-01-01

    Domain-specific languages are computer (programming, modeling, specification) languages devoted to solving problems in a specific domain. The least examined DSL development phases are analysis and design. Various formal methodologies exist, however domain analysis is still done informally most of the time. There are also methodologies of deriving DSLs from existing ontologies but the presumption is to have an ontology for the specific domain. We propose a solution of a user interface driven d...

  3. Altered plasma apolipoprotein modifications in patients with pancreatic cancer: protein characterization and multi-institutional validation.

    Directory of Open Access Journals (Sweden)

    Kazufumi Honda

    Full Text Available BACKGROUND: Among the more common human malignancies, invasive ductal carcinoma of the pancreas has the worst prognosis. The poor outcome seems to be attributable to difficulty in early detection. METHODS: We compared the plasma protein profiles of 112 pancreatic cancer patients with those of 103 sex- and age-matched healthy controls (Cohort 1 using a newly developed matrix-assisted laser desorption/ionization (oMALDI QqTOF (quadrupole time-of-flight mass spectrometry (MS system. RESULTS: We found that hemi-truncated apolipoprotein AII dimer (ApoAII-2; 17252 m/z, unglycosylated apolipoprotein CIII (ApoCIII-0; 8766 m/z, and their summed value were significantly decreased in the pancreatic cancer patients [P = 1.36×10(-21, P = 4.35×10(-14, and P = 1.83×10(-24 (Mann-Whitney U-test; area-under-curve values of 0.877, 0.798, and 0.903, respectively]. The significance was further validated in a total of 1099 plasma/serum samples, consisting of 2 retrospective cohorts [Cohort 2 (n = 103 and Cohort 3 (n = 163] and a prospective cohort [Cohort 4 (n = 833] collected from 8 medical institutions in Japan and Germany. CONCLUSIONS: We have constructed a robust quantitative MS profiling system and used it to validate alterations of modified apolipoproteins in multiple cohorts of patients with pancreatic cancer.

  4. Interactions of metals and Apolipoprotein E in Alzheimer’s disease

    Directory of Open Access Journals (Sweden)

    He eXu

    2014-06-01

    Full Text Available Alzheimer’s disease (AD is the most common form of dementia, which is characterized by the neuropathological accumulation of extracellular amyloid plaques and intracellular neurofibrillary tangles (NFTs. Clinically, patients will endure a gradual erosion of memory and other higher order cognitive functions. Whilst the underlying etiology of the disease remains to be definitively identified, a body of work has developed over the last two decades demonstrating that AD plasma/serum and brain are characterized by a dyshomeostasis in a number of metal ions. Furthermore, these metals (such as zinc, copper and iron play roles in the regulation of the levels AD-related proteins, including the amyloid precursor protein (APP and tau. It is becoming apparent that metals also interact with other proteins, including apolipoprotein E (ApoE. The Apolipoprotein E gene (APOE is critically associated with AD, with APOE4 representing the strongest genetic risk factor for the development of late-onset AD whereas APOE2 appears to have a protective role. In this review we will summarize the evidence supporting a role for metals in the function of Apolipoprotein E (ApoE and its consequent role in the pathogenesis of AD.

  5. The effects of apolipoprotein F deficiency on high density lipoprotein cholesterol metabolism in mice.

    Directory of Open Access Journals (Sweden)

    William R Lagor

    Full Text Available Apolipoprotein F (apoF is 29 kilodalton secreted sialoglycoprotein that resides on the HDL and LDL fractions of human plasma. Human ApoF is also known as Lipid Transfer Inhibitor protein (LTIP based on its ability to inhibit cholesteryl ester transfer protein (CETP-mediated transfer events between lipoproteins. In contrast to other apolipoproteins, ApoF is predicted to lack strong amphipathic alpha helices and its true physiological function remains unknown. We previously showed that overexpression of Apolipoprotein F in mice reduced HDL cholesterol levels by 20-25% by accelerating clearance from the circulation. In order to investigate the effect of physiological levels of ApoF expression on HDL cholesterol metabolism, we generated ApoF deficient mice. Unexpectedly, deletion of ApoF had no substantial impact on plasma lipid concentrations, HDL size, lipid or protein composition. Sex-specific differences were observed in hepatic cholesterol content as well as serum cholesterol efflux capacity. Female ApoF KO mice had increased liver cholesteryl ester content relative to wild type controls on a chow diet (KO: 3.4+/-0.9 mg/dl vs. WT: 1.2+/-0.3 mg/dl, p<0.05. No differences were observed in ABCG1-mediated cholesterol efflux capacity in either sex. Interestingly, ApoB-depleted serum from male KO mice was less effective at promoting ABCA1-mediated cholesterol efflux from J774 macrophages relative to WT controls.

  6. Interferon-γ Protects from Staphylococcal Alpha Toxin-Induced Keratinocyte Death through Apolipoprotein L1.

    Science.gov (United States)

    Brauweiler, Anne M; Goleva, Elena; Leung, Donald Y M

    2016-03-01

    Staphylococcus aureus is a bacterial pathogen that frequently infects the skin, causing lesions and cell destruction through its primary virulence factor, alpha toxin. Here we show that interferon gamma (IFN-?) protects human keratinocytes from cell death induced by staphylococcal alpha toxin. We find that IFN-? prevents alpha toxin binding and reduces expression of the alpha toxin receptor, a disintegrin and metalloproteinase 10 (ADAM10). We determine that the mechanism for IFN-?-mediated resistance to alpha toxin involves the induction of autophagy, a process of cellular adaptation to sublethal damage. We find that IFN-? potently stimulates activation of the primary autophagy effector, light chain 3 (LC3). This process is dependent on upregulation of apolipoprotein L1. Depletion of apolipoprotein L1 by small interfering RNA significantly increases alpha toxin-induced lethality and inhibits activation of light chain 3. We conclude that IFN-? plays a significant role in protecting human keratinocytes from the lethal effects of staphylococcal alpha toxin through apolipoprotein L1-induced autophagy.

  7. Apolipoproteins: Good Markers for Cardiovacular Risk in Patients with Chronic Kidney Disease and Dyslipidemia

    Directory of Open Access Journals (Sweden)

    Tudor Mirela - Nicoleta

    2014-09-01

    Full Text Available Background and aims. Dyslipidemia (DLP is a common complication of chronic kidney disease (CKD and may accelerate its progression. Circulating lipoproteins and their constituent proteins, apolipoproteins, are risk factors for CKD and cardiovascular diseases (CVD. The aim of the study was to determine whether there is a correlation between apolipoproteins and estimated glomerular filtration rate (eGFR or between apolipoproteins and anthropometrical and laboratory parameters or between evaluated cardiovascular risk (CV and dyslipidemia/CKD. Material and methods. We performed a study on 51 subjects from the Nephrology Department of Emergency Clinical County Hospital of Craiova, from November 2011 to July 2013. Results. We found statistically significant correlations between eGFR and Apo A1. Also we found a linear correlation between C-reactive protein (CRP and Apo B. When we evaluated the CV risk using CRP, we found statistically significant differences between the groups (CKD and DLP, only CKD, only DLP and control group, patients with CKD and DLP showing the highest levels of CRP. Conclusions. Elevated levels of Apo A1 are associated with a low rate of CKD. DLP and chronic inflammation play an important role in the progression of CKD. Patients with CKD and DLP had a high cardiovascular risk.

  8. Amyloid-β colocalizes with apolipoprotein B in absorptive cells of the small intestine

    Directory of Open Access Journals (Sweden)

    Dhaliwal Satvinder S

    2009-10-01

    Full Text Available Abstract Background Amyloid-β is recognized as the major constituent of senile plaque found in subjects with Alzheimer's disease. However, there is increasing evidence that in a physiological context amyloid-β may serve as regulating apolipoprotein, primarily of the triglyceride enriched lipoproteins. To consider this hypothesis further, this study utilized an in vivo immunological approach to explore in lipogenic tissue whether amyloid-β colocalizes with nascent triglyceride-rich lipoproteins. Results In murine absorptive epithelial cells of the small intestine, amyloid-β had remarkable colocalization with chylomicrons (Manders overlap coefficient = 0.73 ± 0.03 (SEM, the latter identified as immunoreactive apolipoprotein B. A diet enriched in saturated fats doubled the abundance of both amyloid-β and apo B and increased the overlap coefficient of the two proteins (0.87 ± 0.02. However, there was no evidence that abundance of the two proteins was interdependent within the enterocytes (Pearson's Coefficient Conclusion The findings of this study are consistent with the possibility that amyloid-β is secreted by enterocytes as an apolipoprotein component of chylomicrons. However, secretion of amyloid-β appears to be independent of chylomicron biogenesis.

  9. Crystallization and preliminary X-ray diffraction analysis of apolipoprotein E-containing lipoprotein particles

    Energy Technology Data Exchange (ETDEWEB)

    Newhouse, Yvonne [Gladstone Institutes of Cardiovascular and Neurological Disease, University of California, San Francisco, CA 94158 (United States); Peters-Libeu, Clare [Gladstone Institutes of Cardiovascular and Neurological Disease, University of California, San Francisco, CA 94158 (United States); Cardiovascular Research Institute, University of California, San Francisco, CA 94158 (United States); Weisgraber, Karl H., E-mail: kweisgraber@gladstone.ucsf.edu [Gladstone Institutes of Cardiovascular and Neurological Disease, University of California, San Francisco, CA 94158 (United States); Cardiovascular Research Institute, University of California, San Francisco, CA 94158 (United States); Department of Pathology, University of California, San Francisco, CA 94158 (United States)

    2005-11-01

    Further understanding of the structure and function of plasma apolipoproteins requires the determination of their high-resolution structures when complexed with lipids. In these studies, the production of homogeneous, biologically active lipoprotein particles of apolipoprotein E complexed with dipalmitoylphosphatidylcholine and their crystallization and X-ray diffraction are demonstrated. High-resolution structural information is available for several soluble plasma apolipoproteins (apos) in a lipid-free state. However, this information provides limited insight into structure–function relationships, as this class of proteins primarily performs its functions of lipid transport and modulation of lipid metabolism in a lipid-bound state on lipoprotein particles. Here, the possibility of generating homogeneous lipoprotein particles that could be crystallized was explored, opening the possibility of obtaining high-resolution structural information by X-ray crystallography. To test this possibility, apoE4 complexed with the phospholipid dipalmitoylphosphatidylcholine was chosen. Uniform particles containing 50% lipid and 50% apoE4 were obtained and crystallized using the hanging-drop method. Two crystal forms diffract to beyond 8 Å resolution.

  10. Differential expression of apolipoprotein D in male reproductive system of rats by high-fat diet.

    Science.gov (United States)

    Lim, W; Bae, H; Song, G

    2016-11-01

    Apolipoprotein D, a 29-kDa secreted glycoprotein that belongs to the lipocalin superfamily, is widely expressed in various tissues and associated with lipid metabolism as a component of high-density lipoproteins. Although Apolipoprotein D binds to small hydrophobic ligands including cholesterol, little is known about effects of high-fat diet with cholesterol on expression of Apolipoprotein D in the male reproductive tract. Therefore, we investigated Apod expression in penises, prostate glands, and testes from rats fed a high-fat diet including a high amount of cholesterol. Our previous research indicated that a high-fat diet induces dyslipidemia leading to histological changes and dysfunction of male reproduction in rats. Consistent with these results, Apod mRNA expression was significantly (p high-fat diet as compared with normal diet. In addition, Apod mRNA and protein were detected predominantly in urethral epithelium and penile follicle from rats. Moreover, changes in expression of specific microRNAs (miR-229b-3p, miR-423-3p, and miR-490-3p) regulating Apod in the penises and prostate glands were negatively associated with Apod expression. Collectively, results of this study suggest that Apod is a novel regulatory gene in the male reproductive system, especially in penises of rats fed a high-cholesterol diet, and that expression of Apod is regulated at the posttranscriptional level by target microRNAs.

  11. Lipoprotein lipase activity and mass, apolipoprotein C-II mass and polymorphisms of apolipoproteins E and A5 in subjects with prior acute hypertriglyceridaemic pancreatitis

    Directory of Open Access Journals (Sweden)

    García-Arias Carlota

    2009-06-01

    Full Text Available Abstract Background Severe hypertriglyceridaemia due to chylomicronemia may trigger an acute pancreatitis. However, the basic underlying mechanism is usually not well understood. We decided to analyze some proteins involved in the catabolism of triglyceride-rich lipoproteins in patients with severe hypertriglyceridaemia. Methods Twenty-four survivors of acute hypertriglyceridaemic pancreatitis (cases and 31 patients with severe hypertriglyceridaemia (controls were included. Clinical and anthropometrical data, chylomicronaemia, lipoprotein profile, postheparin lipoprotein lipase mass and activity, hepatic lipase activity, apolipoprotein C II and CIII mass, apo E and A5 polymorphisms were assessed. Results Only five cases were found to have LPL mass and activity deficiency, all of them thin and having the first episode in childhood. No cases had apolipoprotein CII deficiency. No significant differences were found between the non-deficient LPL cases and the controls in terms of obesity, diabetes, alcohol consumption, drug therapy, gender distribution, evidence of fasting chylomicronaemia, lipid levels, LPL activity and mass, hepatic lipase activity, CII and CIII mass or apo E polymorphisms. However, the SNP S19W of apo A5 tended to be more prevalent in cases than controls (40% vs. 23%, NS. Conclusion Primary defects in LPL and C-II are rare in survivors of acute hypertriglyceridaemic pancreatitis; lipase activity measurements should be restricted to those having their first episode during chilhood.

  12. Noninvasive in vivo magnetic resonance imaging of injury-induced neointima formation in the carotid artery of the apolipoprotein-E null mouse.

    Science.gov (United States)

    Manka, D R; Gilson, W; Sarembock, I; Ley, K; Berr, S S

    2000-11-01

    Mice deficient in apolipoprotein-E (apoE) experience severe hypercholesterolemia, are prone to atherosclerosis, and recently have emerged as a powerful tool in the study of plaque formation. In this study, we developed magnetic resonance (MR) imaging methods to detect the progression of atherosclerosis noninvasively in a mouse model of arterial injury. Four 14-week-old apoE-deficient mice were imaged 5 weeks after beginning an atherogenic Western diet and 4 weeks after wire denudation injury of the left common carotid artery (LCCA). Information from several images was combined into high-information content images using methods previously developed. The image resolution was 47 x 47 x 750 microm(3). We acquired T1-, T2-, and proton density (PD)-weighted images (TR/TE 650/14, 2000/60, and 2000/14 msec, respectively). Each 8-bit image was placed in a separate color channel to produce a 24-bit color image (red = T1, green = PD, and blue = T2). The composite image created contrast between different tissue types that was superior to that of any single image and revealed significant luminal narrowing of the LCCA, but not the uninjured RCCA. MR images were compared with corresponding histopathology cross sections and luminal area measurements from each method correlated(r2= 0.61). Atherosclerotic luminal narrowing was successfully detected through MR imaging in a mouse model of arterial injury that is small, reproduces quickly, and lends itself to genetic analysis and manipulation.

  13. Protein domain organisation: adding order

    Directory of Open Access Journals (Sweden)

    Kummerfeld Sarah K

    2009-01-01

    Full Text Available Abstract Background Domains are the building blocks of proteins. During evolution, they have been duplicated, fused and recombined, to produce proteins with novel structures and functions. Structural and genome-scale studies have shown that pairs or groups of domains observed together in a protein are almost always found in only one N to C terminal order and are the result of a single recombination event that has been propagated by duplication of the multi-domain unit. Previous studies of domain organisation have used graph theory to represent the co-occurrence of domains within proteins. We build on this approach by adding directionality to the graphs and connecting nodes based on their relative order in the protein. Most of the time, the linear order of domains is conserved. However, using the directed graph representation we have identified non-linear features of domain organization that are over-represented in genomes. Recognising these patterns and unravelling how they have arisen may allow us to understand the functional relationships between domains and understand how the protein repertoire has evolved. Results We identify groups of domains that are not linearly conserved, but instead have been shuffled during evolution so that they occur in multiple different orders. We consider 192 genomes across all three kingdoms of life and use domain and protein annotation to understand their functional significance. To identify these features and assess their statistical significance, we represent the linear order of domains in proteins as a directed graph and apply graph theoretical methods. We describe two higher-order patterns of domain organisation: clusters and bi-directionally associated domain pairs and explore their functional importance and phylogenetic conservation. Conclusion Taking into account the order of domains, we have derived a novel picture of global protein organization. We found that all genomes have a higher than expected

  14. Peptides Derived from Type IV Collagen, CXC Chemokines, and Thrombospondin-1 Domain-Containing Proteins Inhibit Neovascularization and Suppress Tumor Growth in MDA-MB-231 Breast Cancer Xenografts

    Directory of Open Access Journals (Sweden)

    Jacob E. Koskimaki

    2009-12-01

    Full Text Available Angiogenesis or neovascularization, the process of new blood vessel formation from preexisting microvasculature, involves interactions among several cell types including parenchymal, endothelial cells, and immune cells. The formation of new vessels is tightly regulated by a balance between endogenous proangiogenic and antiangiogenic factors to maintain homeostasis in tissue; tumor progression and metastasis in breast cancer have been shown to be angiogenesis-dependent. We previously introduced a systematic methodology to identify putative endogenous antiangiogenic peptides and validated these predictions in vitro in human umbilical vein endothelial cell proliferation and migration assays. These peptides are derived from several protein families including type IV collagen, CXC chemokines, and thrombospondin-1 domain-containing proteins. On the basis of the results from the in vitro screening, we have evaluated the ability of one peptide selected from each family named pentastatin-1, chemokinostatin-1, and properdistatin, respectively, to suppress angiogenesis in an MDA-MB-231 human breast cancer orthotopic xenograft model in severe combined immunodeficient mice. Peptides were administered intraperitoneally once per day. We have demonstrated significant suppression of tumor growth in vivo and subsequent reductions in microvascular density, indicating the potential of these peptides as therapeutic agents for breast cancer.

  15. Apolipoprotein E inhibits toll-like receptor (TLR)-3- and TLR-4-mediated macrophage activation through distinct mechanisms.

    Science.gov (United States)

    Zhu, Yanjuan; Kodvawala, Ahmer; Hui, David Y

    2010-04-28

    Previous studies have shown that apoE (apolipoprotein E) expression in macrophages suppresses inflammatory responses; however, whether endogenously synthesized apoE acts intracellularly or after its secretion in suppressing macrophage inflammation remains unclear. The present study used the murine monocyte macrophage cell line RAW 264.7 to examine the influence of exogenous apoE on macrophage inflammatory responses induced by TLR (Toll-like receptor)-4 and TLR-3 agonists LPS (lipopolysaccharide) and poly(I-C) respectively. Results showed that exogenously added apoE suppressed the LPS and poly(I-C) induction of IL (interleukin)-6, IL-1beta and TNF-alpha (tumour necrosis factor-alpha) secretion by RAW 264.7 cells. The mechanism was related to apoE suppression of TLR-agonist-induced phosphorylation of JNK (c-Jun N-terminal kinase) and c-Jun. A peptide containing the tandem repeat sequence of the receptor-binding domain of apoE, apoE-(141-155)2, was similarly effective in inhibiting LPS- and poly(I-C)-induced macrophage inflammatory responses. Reductive methylation of lysine residues in apoE, which abolished its receptor-binding capability without affecting its ability to interact with HSPGs (heparin sulfate proteoglycans), inhibited the ability of apoE to suppress macrophage responses to LPS, but had no effect on apoE suppression of poly(I-C)-induced macrophage activation. The ability of apoE to suppress poly(I-C)-induced pro-inflammatory cytokine production was abolished by heparinase treatment of RAW 264.7 cells to remove cell-surface HSPGs. Taken together, these results indicate that exogenous apoE inhibits macrophage inflammatory responses to TLR-4 and TLR-3 agonists through distinct mechanisms related to receptor and HSPG binding respectively, and that these inhibitory effects converged on suppression of JNK and c-Jun activation which are necessary for macrophage activation.

  16. Apolipoprotein B-containing lipoprotein particle assembly: Lipid capacity of the nascent lipoprotein particle

    Energy Technology Data Exchange (ETDEWEB)

    Manchekar, Medha; Forte, Trudy M.; Datta, Geeta; Richardson, Paul E.; Segrest, Jere P.; Dashti, Nassrin

    2003-12-01

    We previously proposed that the N-terminal 1000 residue {beta}{alpha}{sub 1} domain of apolipoprotein B (apoB) forms a bulk lipid pocket homologous to that of lamprey lipovitellin (LV). In support of this ''lipid pocket'' hypothesis, apoB:1000 (residues 1-1000) was shown to be secreted by a stable transformant of McA-RH7777 cells as a monodisperse particle with HDL{sub 3} density and Stokes diameter of 112 {angstrom}. In contrast, apoB:931 (residues 1-931), missing only 69 residues of the sequence homologous to LV, was secreted as a particle considerably more dense than HDL with Stokes diameter of 110 {angstrom}. The purpose of the present study was to determine the stoichiometry of the lipid component of the apoB:931 and apoB:1000 particles. This was accomplished by metabolic labeling of cells with either [{sup 14}C]oleic acid or [{sup 3}H]glycerol followed by immunoprecipitation (IP) or nondenaturing gradient gel electrophoresis (NDGGE) of secreted lipoproteins and by immunoaffinity chromatography of secreted unlabeled lipoproteins. The [{sup 3}H]-labeled apoB:1000-containing particles, isolated by NDGGE, contained 50 phospholipids (PL) and 11 triacylglycerols (TAG) molecules per particle. In contrast, apoB:931-containing particles contained only a few molecules of PL and were devoid of TAG. The unlabeled apoB:1000-containing particles isolated by immunoaffinity chromatography and analyzed for lipid mass, contained 56 PL, 8 TAG, and 7 cholesteryl ester molecules per particle. The surface:core lipid ratio of apoB:1000-containing particles was approximately 4:1 and was not affected by incubation of cells with oleate. Although small amounts of microsomal triglyceride transfer protein (MTP) were associated with apoB:1000-containing particles, it never approached a 1:1 molar ratio of MTP to apoB. These results support a model in which: (1) the first 1000 amino acid residues of apoB are competent to complete the ''lipid pocket

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

    Science.gov (United States)

    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

    2016-03-04

    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.

  18. .Gov Domains API

    Data.gov (United States)

    General Services Administration — This dataset offers the list of all .gov domains, including state, local, and tribal .gov domains. It does not include .mil domains, or other federal domains outside...

  19. The PRE-Derived NMR Model of the 38.8-kDa Tri-Domain IsdH Protein from Staphylococcus aureus Suggests That It Adaptively Recognizes Human Hemoglobin.

    Science.gov (United States)

    Sjodt, Megan; Macdonald, Ramsay; Spirig, Thomas; Chan, Albert H; Dickson, Claire F; Fabian, Marian; Olson, John S; Gell, David A; Clubb, Robert T

    2016-03-27

    Staphylococcus aureus is a medically important bacterial pathogen that, during infections, acquires iron from human hemoglobin (Hb). It uses two closely related iron-regulated surface determinant (Isd) proteins to capture and extract the oxidized form of heme (hemin) from Hb, IsdH and IsdB. Both receptors rapidly extract hemin using a conserved tri-domain unit consisting of two NEAT (near iron transporter) domains connected by a helical linker domain. To gain insight into the mechanism of extraction, we used NMR to investigate the structure and dynamics of the 38.8-kDa tri-domain IsdH protein (IsdH(N2N3), A326-D660 with a Y642A mutation that prevents hemin binding). The structure was modeled using long-range paramagnetic relaxation enhancement (PRE) distance restraints, dihedral angle, small-angle X-ray scattering, residual dipolar coupling and inter-domain NOE nuclear Overhauser effect data. The receptor adopts an extended conformation wherein the linker and N3 domains pack against each other via a hydrophobic interface. In contrast, the N2 domain contacts the linker domain via a hydrophilic interface and, based on NMR relaxation data, undergoes inter-domain motions enabling it to reorient with respect to the body of the protein. Ensemble calculations were used to estimate the range of N2 domain positions compatible with the PRE data. A comparison of the Hb-free and Hb-bound forms reveals that Hb binding alters the positioning of the N2 domain. We propose that binding occurs through a combination of conformational selection and induced-fit mechanisms that may promote hemin release from Hb by altering the position of its F helix.

  20. Discovery and consequences of apolipoprotein-epsilon(3Groningen) : a G-insertion in codon 95/96 that is predicted to cause a premature stop codon

    NARCIS (Netherlands)

    Dijck-Brouwer, DAJ; van Doormaal, JJ; Kema, IP; Brugman, AM; Kingma, AW; Muskiet, FAJ

    2005-01-01

    Background We found an unexplained, persistent discrepancy between the outcomes of two apolipoprotein-E (apo-E) genotyping methods for a patient with features of familial dysbetalipoproteinaemia (FD). Polymerase chain reaction restriction fragment length polymorphism resulted in the apo-epsilon(2)/e

  1. Polymorphism of apolipoprotein E gene and post-stroke vascular dementia

    Institute of Scientific and Technical Information of China (English)

    Xinjing Lin; Changlin Hu; Yunlan Xie; Xin Zhang; Xiangping Liu; Ge Yan

    2006-01-01

    BACKGROUND: Studies have indicated that the more certain etiological factors of vascular dementia are the sites, size and number of cerebrovascular lesions, but there are arguments all the time in the relationship of genetic factors, especially apolipoprotein E gene, with the occurrence and development of vascular dementia. OBJECTIVE: To analyze the relationship between the polymorphism of apolipoprotein E gene and vascular dementia in stroke patients. DESIGN: A non-randomized grouped comparative observation at the same time. SETTING: The Laboratory of Neurology, the Second Affiliated Hospital of Chongqing University of Medical Sciences.PARTICIPANTS: Totally 121 inpatients with stroke were selected from the Department of Neurology, the Second Affiliated Hospital of Chongqing University of Medical Sciences from January 2000 to December 2001. All the patients were accorded with the diagnostic standards for cerebrovascular diseases set by the Second National Academic Meeting for Cerebrovascular Disease, and confirmed by cranial CT or MRI. According to with vascular dementia or not, they were divided into vascular dementia group (n =58) and non-vascular dementia group (n =63). In the vascular dementia group, there were 37 males and 21 females, the average age was (59±8) years. They were all in accordance with the standard of the third edition of Diagnostic and Statistical Manual of Mental Disorders (DMS-Ⅲ), without conscious disturbance and language disorder; hospitalized within 3 days after the attack of cerebrovascular disease. In the non-vascular dementia group, there were 37 males and 26 females, the average age was (59±9.5) years. They all had no intellectual disturbance within 3 months after the attack of cerebrovascular disease. All the subjects agreed to supply blood samples for the experiment. METHODS: ①Fasting venous blood (2 mL) was drawn from each patient in the morning to extract DNA. The frequencies of apolipoprotein E genotypes and alleles were

  2. [Interaction of human apolipoprotein AI and HIV-1 envelope proteins with the native and recombinant CD4 receptors].

    Science.gov (United States)

    Panin, L E; Kostina, N E

    2003-01-01

    The method of enzyme-linked immunosorbent assay (ELISA) was used to show an interaction of soluble recombinant CD4-receptor (rsCD4) with human apolipoprotein A-1. Competitive interactions between envelope proteins VIH-1 (gp120 and gp41), on the one hand, and human apolipoprotein A-1 with CD4 receptor, present in the cellular membranes of line MT4 human lymphocytes, were demonstrated by the method of flow cytofluorimetry. It was suggested that the competitive interactions between the above proteins could manifest in respect to the apolipoprotein A-1 receptor, which affects the involvement of the latter in the regulation of protein biosynthesis and which leads to a decrease in the body weight of HIV-infected patients.

  3. Fasting and nonfasting lipid levels: influence of normal food intake on lipids, lipoproteins, apolipoproteins, and cardiovascular risk prediction

    DEFF Research Database (Denmark)

    Langsted, A.; Freiberg, J.J.; Nordestgaard, Børge

    2008-01-01

    BACKGROUND: Lipid profiles are usually measured after fasting. We tested the hypotheses that these levels change only minimally in response to normal food intake and that nonfasting levels predict cardiovascular events. METHODS AND RESULTS: We cross-sectionally studied 33 391 individuals 20 to 95...... to HDL cholesterol, and ratio of apolipoprotein B to apolipoprotein A1 did not change in response to normal food intake. The maximum changes after normal food and fluid intake from fasting levels were -0.2 mmol/L for total cholesterol, -0.2 mmol/L for low-density lipoprotein cholesterol, -0.1 mmol...... and lowest versus highest tertile of nonfasting HDL cholesterol and apolipoprotein A1 predicted 1.7- to 2.4-fold increased risk of cardiovascular events. CONCLUSIONS: Lipid profiles at most change minimally in response to normal food intake in individuals in the general population. Furthermore, nonfasting...

  4. Perfect Derived Propagators

    CERN Document Server

    Schulte, Christian

    2008-01-01

    When implementing a propagator for a constraint, one must decide about variants: When implementing min, should one also implement max? Should one implement linear equations both with and without coefficients? Constraint variants are ubiquitous: implementing them requires considerable (if not prohibitive) effort and decreases maintainability, but will deliver better performance. This paper shows how to use variable views, previously introduced for an implementation architecture, to derive perfect propagator variants. A model for views and derived propagators is introduced. Derived propagators are proved to be indeed perfect in that they inherit essential properties such as correctness and domain and bounds consistency. Techniques for systematically deriving propagators such as transformation, generalization, specialization, and channeling are developed for several variable domains. We evaluate the massive impact of derived propagators. Without derived propagators, Gecode would require 140000 rather than 40000 ...

  5. The age dependency of gene expression for plasma lipids, lipoproteins, and apolipoproteins

    Energy Technology Data Exchange (ETDEWEB)

    Snieder, H.; Doornen, L.J.P. van; Boomsma, D.I. [Vrije Universiteit, Amsterdam (Netherlands)

    1997-03-01

    The aim of this study was to investigate and disentangle the genetic and nongenetic causes of stability and change in lipids and (apo)lipoproteins that occur during the lifespan. Total cholesterol, low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglycerides, apolipoprotein A1 (ApoA1), apolipoprotein B (ApoB), and lipoprotein(a) (Lp[a]) were measured in a group of 160 middle-aged parents and their twin offspring (first project) and in a group of 203 middle-aged twin pairs (second project). Combining the data of both projects enabled the estimation of the extent to which measured lipid parameters are influenced by different genes in adolescence and adulthood. To that end, an extended quantitative genetic model was specified, which allowed the estimation of heritabilities for each sex and generation separately. Heritabilities were similar for both sexes and both generations. Larger variances in the parental generation could be ascribed to proportional increases in both unique environmental and additive genetic variance from childhood to adulthood, which led to similar heritability estimates in adolescent and middle-aged twins. Although the magnitudes of heritabilities were similar across generations, results showed that, for total cholesterol, triglycerides, HDL, and LDL, partly different genes are expressed in adolescence compared to adulthood. For triglycerides, only 46% of the genetic variance was common to both age groups; for total cholesterol this was 80%. Intermediate values were found for HDL (66%) and LDL (76%). For ApoA1, ApoB, and Lp(a), the same genes seem to act in both generations. 56 refs., 2 figs., 5 tabs.

  6. Metformin reduces the endotoxin-induced down-regulation of apolipoprotein E gene expression in macrophages

    Energy Technology Data Exchange (ETDEWEB)

    Stavri, Simona; Trusca, Violeta G.; Simionescu, Maya; Gafencu, Anca V., E-mail: anca.gafencu@icbp.ro

    2015-05-29

    The atheroprotective role of macrophage-derived apolipoprotein E (apoE) is well known. Our previous reports demonstrated that inflammatory stress down-regulates apoE expression in macrophages, aggravating atherogenesis. Metformin, extensively used as an anti-diabetic drug, has also anti-inflammatory properties, and thus confers vascular protection. In this study, we questioned whether metformin could have an effect on apoE expression in macrophages in normal conditions or under lipopolysaccharide (LPS)-induced stress. The results showed that metformin slightly increases the apoE expression only at high doses (5–10 mM). Low doses of metformin (1–3 mM) significantly reduce the LPS down-regulatory effect on apoE expression in macrophages. Our experiments demonstrated that LPS-induced NF-κB binds to the macrophage-specific distal regulatory element of apoE gene, namely to the multienhancer 2 (ME.2) and its 5′-deletion fragments. The NF-κB binding on ME.2 and apoE promoter has a down-regulatory effect. In addition, data revealed that metformin impairs NF-κB nuclear translocation, and thus, improves the apoE levels in macrophages under inflammatory stress. The positive effect of metformin in the inflammatory states, its clinical safety and low cost, make this drug a potential adjuvant in the therapeutic strategies for atherosclerosis. - Highlights: • High doses of metformin slightly increase apoE expression in macrophages. • Low doses of metformin up-regulate apoE gene in endotoxin-stressed macrophages. • Metformin reduces the negative effect of LPS on apoE expression by NF-κB inhibition.

  7. Apolipoprotein AV Accelerates Plasma Hydrolysis OfTriglyceride-Rich Lipoproteins By Interaction With Proteoglycan BoundLipoprotein Lipase

    Energy Technology Data Exchange (ETDEWEB)

    Merkel, Martin; Loeffler, Britta; Kluger, Malte; Fabig, Nathalie; Geppert, Gesa; Pennacchio, Len A.; Laatsch, Alexander; Heeren, Joerg

    2005-02-22

    Apolipoprotein A5 (APOA5) is associated with differences intriglyceride levels and familial combined hyperlipidemia. In genetically engineered mice, apoAV plasma levels are inversely correlated with plasmatriglycerides. To elucidate the mechanism by which apoAV influences plasma triglycerides, metabolic studies and in vitro assays resembling physiological conditions were performed. In hAPOA5 transgenic mice(hAPOA5tr), catabolism of chylomicrons and VLDL was accelerated due to a faster plasma hydrolysis of triglycerides by lipoprotein lipase (LPL).Hepatic VLDL and intestinal chylomicron production were not affected. The functional interplay between apoAV and LPL was further investigated by crossbreeding a human LPL transgene with the apoa5 knockout, and the hAPOA5tr to an LPL deficient background. Increased LPL activity completely normalized hypertriglyceridemia of apoa5 deficient mice,however, over expression of human apoAV modulated triglyceride levels only slightly when LPL was reduced. To reflect the physiological situation in which LPL is bound to cell surface proteoglycans, we examined hydrolysis in the presence or absence of proteoglycans. Without proteoglycans, apoAV derived either from triglyceride-rich lipoproteins, hAPOA5tr HDL, or a recombinant source did not alter the LPL hydrolysis rate. In the presence of proteoglycans, however, apoAV led to a significant and dose-dependent increase in LPL mediated hydrolysis of VLDL triglycerides. These results were confirmed in cell culture using a proteoglycan-deficient cell line.A direct interaction between LPL and apoAV was found by ligand blotting.It is proposed, that apoAV reduces triglyceride levels by guiding VLDL and chylomicrons to proteoglycans bound LPL for lipolysis.

  8. Structure of axionic domain walls

    Science.gov (United States)

    Huang, M. C.; Sikivie, P.

    1985-09-01

    The structure of axionic domain walls is investigated using the low-energy effective theory of axions and pions. We derive the spatial dependence of the phases of the Peccei-Quinn scalar field and the QCD quark-antiquark condensates inside an axionic domain wall. Thence an accurate estimate of the wall surface energy density is obtained. The equations of motion for axions, photons, leptons, and baryons in the neighborhood of axionic domain walls are written down and estimates are given for the wall reflection and transmission coefficients of these particles. Finally, we discuss the energy dissipation by axionic domain walls oscillating in the early universe due to the reflection of particles in the primordial soup.

  9. Structure of axionic domain walls

    Energy Technology Data Exchange (ETDEWEB)

    Huang, M.C.; Sikivie, P.

    1985-09-15

    The structure of axionic domain walls is investigated using the low-energy effective theory of axions and pions. We derive the spatial dependence of the phases of the Peccei-Quinn scalar field and the QCD quark-antiquark condensates inside an axionic domain wall. Thence an accurate estimate of the wall surface energy density is obtained. The equations of motion for axions, photons, leptons, and baryons in the neighborhood of axionic domain walls are written down and estimates are given for the wall reflection and transmission coefficients of these particles. Finally, we discuss the energy dissipation by axionic domain walls oscillating in the early universe due to the reflection of particles in the primordial soup.

  10. Erythrocyte-bound apolipoprotein B in relation to atherosclerosis, serum lipids and ABO blood group.

    Directory of Open Access Journals (Sweden)

    Boudewijn Klop

    Full Text Available INTRODUCTION: Erythrocytes carry apolipoprotein B on their membrane, but the determining factors of erythrocyte-bound apolipoprotein B (ery-apoB are unknown. We aimed to explore the determinants of ery-apoB to gain more insight into potential mechanisms. METHODS: Subjects with and without CVD were included (N = 398. Ery-apoB was measured on fresh whole blood samples using flow cytometry. Subjects with ery-apoB levels ≤ 0.20 a.u. were considered deficient. Carotid intima media thickness (CIMT was determined as a measure of (subclinical atherosclerosis. RESULTS: Mean ery-apoB value was 23.2% lower in subjects with increased CIMT (0.80 ± 0.09 mm, N = 140 compared to subjects with a normal CIMT (0.57 ± 0.08 mm, N = 258 (P = 0.007, adjusted P<0.001. CIMT and ery-apoB were inversely correlated (Spearman's r: -0.116, P = 0.021. A total of 55 subjects (13.6% were considered ery-apoB deficient, which was associated with a medical history of CVD (OR: 1.86, 95% CI 1.04-3.33; adjusted OR: 1.55; 95% CI 0.85-2.82. Discontinuation of statins in 54 subjects did not influence ery-apoB values despite a 58.4% increase in serum apolipoprotein B. Subjects with blood group O had significantly higher ery-apoB values (1.56 ± 0.94 a.u. when compared to subjects with blood group A (0.89 ± 1.15 a.u, blood group B (0.73 ± 0.1.12 a.u. or blood group AB (0.69 ± 0.69 a.u. (P-ANOVA = 0.002. CONCLUSION: Absence or very low values of ery-apoB are associated with clinical and subclinical atherosclerosis. While serum apolipoprotein B is not associated with ery-apoB, the ABO blood group seems to be a significant determinant.

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

    Science.gov (United States)

    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.

  12. Molecular basis of the apolipoprotein H (beta 2-glycoprotein I) protein polymorphism

    DEFF Research Database (Denmark)

    Sanghera, Dharambir K; Kristensen, Torsten; Hamman, Richard F

    1997-01-01

    Apolipoprotein H (apoH, protein; APOH, gene) is considered to be an essential cofactor for the binding of certain antiphospholipid autoantibodies to anionic phospholipids. APOH exhibits a genetically determined structural polymorphism due to the presence of three common alleles (APOH*1, APOH*2...... and its distribution in three large U.S. population samples comprising 661 non-Hispanic whites, 444 Hispanics and 422 blacks. By direct DNA sequencing of PCR amplified fragments corresponding to the eight APOH exons, we identified two missense mutations that correspond to the APOH*1 and APOH*3W alleles...

  13. Apolipoprotein D is associated with long-term outcome in patients with schizophrenia

    DEFF Research Database (Denmark)

    Hansen, T; Hemmingsen, R P; Wang, A G;

    2006-01-01

    , genetic variation in the ApoD is associated with long-term clinical outcome to antipsychotic treatment. We genotyped two single-nucleotide polymorphisms in the ApoD gene in 343 chronic patients with schizophrenia spectrum disorders (ICD-10) and 346 control subjects of Danish origin. We did not find Apo......Accumulating evidence implicates deficiencies in apolipoprotein D (ApoD) function and arachidonic acid signaling in schizophrenic disorders. We addressed two hypotheses in relation to ApoD: first, polymorphisms in the ApoD gene confer susceptibility to or are markers of disease, and, second...

  14. Apolipoprotein D is associated with long-term outcome in patients with schizophrenia

    DEFF Research Database (Denmark)

    Hansen, Thomas Folkmann; Hemmingsen, R P; Wang, A G;

    2006-01-01

    Accumulating evidence implicates deficiencies in apolipoprotein D (ApoD) function and arachidonic acid signaling in schizophrenic disorders. We addressed two hypotheses in relation to ApoD: first, polymorphisms in the ApoD gene confer susceptibility to or are markers of disease, and, second......, genetic variation in the ApoD is associated with long-term clinical outcome to antipsychotic treatment. We genotyped two single-nucleotide polymorphisms in the ApoD gene in 343 chronic patients with schizophrenia spectrum disorders (ICD-10) and 346 control subjects of Danish origin. We did not find Apo...

  15. Apolipoprotein E4 influences growth and cognitive responses to micronutrient supplementation in shantytown children from northeast Brazil

    Directory of Open Access Journals (Sweden)

    Sumeet S Mitter

    2012-01-01

    Full Text Available OBJECTIVE: Apolipoprotein E4 may benefit children during early periods of life when the body is challenged by infection and nutritional decline. We examined whether apolipoprotein E4 affects intestinal barrier function, improving short-term growth and long-term cognitive outcomes in Brazilian shantytown children. METHODS: A total of 213 Brazilian shantytown children with below-median height-for-age z-scores (HAZ received 200,000 IU of retinol (every four months, zinc (40 mg twice weekly, or both for one year, with half of each group receiving glutamine supplementation for 10 days. Height-for-age z-scores, weight-for-age z-scores, weight-forheight z-scores, and lactulose:mannitol ratios were assessed during the initial four months of treatment. An average of four years (range 1.4-6.6 later, the children underwent cognitive testing to evaluate non-verbal intelligence, coding, verbal fluency, verbal learning, and delayed verbal learning. Apolipoprotein E4 carriage was determined by PCR analysis for 144 children. RESULTS: Thirty-seven children were apolipoprotein E4(+, with an allele frequency of 13.9%. Significant associations were found for vitamin A and glutamine with intestinal barrier function. Apolipoprotein E4(+ children receiving glutamine presented significant positive Pearson correlations between the change in height-for-age z-scores over four months and delayed verbal learning, along with correlated changes over the same period in weight-for-age z-scores and weight-for-height z-scores associated with non-verbal intelligence quotients. There was a significant correlation between vitamin A supplementation of apolipoprotein E4(+ children and improved delta lactulose/mannitol. Apolipoprotein E4(- children, regardless of intervention, exhibited negative Pearson correlations between the change in lactulose-to-mannitol ratio over four months and verbal learning and non-verbal intelligence. CONCLUSIONS: During development, apolipoprotein E4 may

  16. The effect of six polymorphisms in the Apolipoprotein B gene on parameters of lipid metabolism in a Danish population

    DEFF Research Database (Denmark)

    Bentzen, J; Jørgensen, T; Fenger, M

    2002-01-01

    Lipoproteins are vehicles for the distribution of plasma lipids and polymorphisms in the genes for apolipoproteins could influence the amount of lipid in plasma. We examined the effect of six single nucleotide polymorphisms in codons 71, 591, 2488, 2712, 3611, and 4154 of the apolipoprotein B gene...... on fasting levels of triglyceride, VLDL-, LDL-, HDL- and total cholesterol and on body mass index (BMI) in a cohort of 2656 Danes aged 40-70 years using a linear model correcting for the effects of gender, age, BMI, smoking, alcohol consumption and physical activity. The codon 2488 polymorphism was the most...

  17. Predicting domain-domain interaction based on domain profiles with feature selection and support vector machines

    Directory of Open Access Journals (Sweden)

    Liao Li

    2010-10-01

    Full Text Available Abstract Background Protein-protein interaction (PPI plays essential roles in cellular functions. The cost, time and other limitations associated with the current experimental methods have motivated the development of computational methods for predicting PPIs. As protein interactions generally occur via domains instead of the whole molecules, predicting domain-domain interaction (DDI is an important step toward PPI prediction. Computational methods developed so far have utilized information from various sources at different levels, from primary sequences, to molecular structures, to evolutionary profiles. Results In this paper, we propose a computational method to predict DDI using support vector machines (SVMs, based on domains represented as interaction profile hidden Markov models (ipHMM where interacting residues in domains are explicitly modeled according to the three dimensional structural information available at the Protein Data Bank (PDB. Features about the domains are extracted first as the Fisher scores derived from the ipHMM and then selected using singular value decomposition (SVD. Domain pairs are represented by concatenating their selected feature vectors, and classified by a support vector machine trained on these feature vectors. The method is tested by leave-one-out cross validation experiments with a set of interacting protein pairs adopted from the 3DID database. The prediction accuracy has shown significant improvement as compared to InterPreTS (Interaction Prediction through Tertiary Structure, an existing method for PPI prediction that also uses the sequences and complexes of known 3D structure. Conclusions We show that domain-domain interaction prediction can be significantly enhanced by exploiting information inherent in the domain profiles via feature selection based on Fisher scores, singular value decomposition and supervised learning based on support vector machines. Datasets and source code are freely available on

  18. Association of apolipoprotein E polymorphism in late-onset Alzheimer's disease and vascular dementia in Brazilians

    Directory of Open Access Journals (Sweden)

    D.R.S. Souza

    2003-07-01

    Full Text Available The genetic basis for dementias is complex. A common polymorphism in the apolipoprotein E (APOE gene is considered to be the major risk factor in families with sporadic and late-onset Alzheimer's disease as well as in the general population. The distribution of alleles and genotypes of the APOE gene in late-onset Alzheimer's disease (N = 68, other late-life dementias (N = 39, and in cognitively normal controls (N = 58 was determined, as also was the risk for Alzheimer's disease associated with the epsilon4 allele. Peripheral blood samples were obtained from a total of 165 individuals living in Brazil aged 65-82 years. Genomic DNA was amplified by the polymerase chain reaction and the products were digested with HhaI restriction enzyme. APOE epsilon2 frequency was considerably lower in the Alzheimer's disease group (1%, and the epsilon3 allele and epsilon3/epsilon3 genotype frequencies were higher in the controls (84 and 72%, respectively as were the epsilon4 allele and epsilon3/epsilon4 genotype frequencies in Alzheimer's disease (25 and 41%, respectively. The higher frequency of the epsilon4 allele in Alzheimer's disease confirmed its role as a risk factor, while epsilon2 provided a weak protection against development of the disease. However, in view of the unexpectedly low frequency of the epsilon4 allele, additional analyses in a more varied Brazilian sample are needed to clarify the real contribution of apolipoprotein E to the development of Alzheimer's disease in this population.

  19. Does Apolipoprotein E genotype affect cardiovascular risk in subjects with acromegaly?

    Science.gov (United States)

    Bozok Cetintas, Vildan; Zengi, Ayhan; Tetik, Asli; Karadeniz, Muammer; Ergonen, Faruk; Kucukaslan, Ali Sahin; Tamsel, Sadik; Kosova, Buket; Sahin, Serap Baydur; Saygılı, Fusun; Eroglu, Zuhal

    2012-06-01

    Acromegaly is a syndrome that results when the pituitary gland produces excess growth hormone after epiphyseal closure at puberty. Usually, subjects with acromegaly exhibit a 2- to 3-fold higher mortality rate from diseases that are associated with cardiovascular complications when compared to the normal population. In this study, we therefore aimed to evaluate whether a well-established cardiovascular risk factor, the Apolipoprotein E (Apo E) genotype, contributes to increased risk of cardiovascular complications in subjects with acromegaly. A total of 102 unrelated acromegaly subjects were prospectively included into this case-control association study and constituted our study group. The study group was comparable by age and gender with 200 unrelated healthy subjects constituting our control group. Genomic DNA was isolated from the peripheral blood leukocytes of all subjects and Apo E genotype (codon 112/158) was assessed by melting temperature analyses after using a real-time PCR protocol. The Apolipoprotein E4 allele was found at a significantly higher frequency in the study group when compared with the control group (P = 0.032). Subjects with the E2 allele, on the other hand, had significantly increased values in body mass index (P = 0.004), waist circumference (P = 0.001), C-reactive protein (CRP) (P acromegaly since it is concurrently present with other cardiovascular risk factors such as the left-side carotid intima media thickness and CRP.

  20. Molecular structure of an apolipoprotein determined at 2. 5- angstrom resolution

    Energy Technology Data Exchange (ETDEWEB)

    Breiter, D.R.; Benning, M.M.; Wesenberg, G.; Holden, H.M.; Rayment, I. (Univ. of Wisconsin, Madison (USA)); Kanost, M.R.; Law, J.H.; Wells, M.A. (Univ. of Arizona, Tucson (USA))

    1991-01-22

    The three-dimensional structure of an apolipoprotein isolated from the African migratory locust Locusta migratoria has been determined by X-ray analysis to a resolution of 2.5 {angstrom}. The overall molecular architecture of this protein consists of five long {alpha}-helices connected by short loops. As predicted from amino acid sequence analyses, these helices are distinctly amphiphilic with the hydrophobic residues pointing in toward the interior of the protein and the hydrophilic side chains facing outward. The molecule falls into the general category of up-and-down {alpha}-helical bundles as previously observed, for example, in cytochrome c{prime}. Although the structure shows the presence of five long amphiphilic {alpha}-helices, the {alpha}-helical moment and hydrophobicity of the entire molecule fall into the range found for normal globular proteins. Thus, in order for the amphiphilic helices to play a role in the binding of the protein to a lipid surface, there must be a structural reorganization of the protein which exposes the hydrophobic interior to the lipid surface. The three dimensional motif of this apolipoprotein is compatible with a model in which the molecule binds to the lipid surface via a relatively nonpolar end and then spreads on the surface in such a way as to cause the hydrophobic side chains of the helices to come in contact with the lipid surface, the charged and polar residues to remain in contact with water, and the overall helical motif of the protein to be maintained.

  1. Apolipoprotein CIII links islet insulin resistance to β-cell failure in diabetes

    Science.gov (United States)

    Åvall, Karin; Ali, Yusuf; Leibiger, Ingo B.; Leibiger, Barbara; Moede, Tilo; Paschen, Meike; Dicker, Andrea; Daré, Elisabetta; Köhler, Martin; Ilegems, Erwin; Abdulreda, Midhat H.; Graham, Mark; Crooke, Rosanne M.; Tay, Vanessa S. Y.; Refai, Essam; Nilsson, Stefan K.; Jacob, Stefan; Selander, Lars; Berggren, Per-Olof; Juntti-Berggren, Lisa

    2015-01-01

    Insulin resistance and β-cell failure are the major defects in type 2 diabetes mellitus. However, the molecular mechanisms linking these two defects remain unknown. Elevated levels of apolipoprotein CIII (apoCIII) are associated not only with insulin resistance but also with cardiovascular disorders and inflammation. We now demonstrate that local apoCIII production is connected to pancreatic islet insulin resistance and β-cell failure. An increase in islet apoCIII causes promotion of a local inflammatory milieu, increased mitochondrial metabolism, deranged regulation of β-cell cytoplasmic free Ca2+ concentration ([Ca2+]i) and apoptosis. Decreasing apoCIII in vivo results in improved glucose tolerance, and pancreatic apoCIII knockout islets transplanted into diabetic mice, with high systemic levels of the apolipoprotein, demonstrate a normal [Ca2+]i response pattern and no hallmarks of inflammation. Hence, under conditions of islet insulin resistance, locally produced apoCIII is an important diabetogenic factor involved in impairment of β-cell function and may thus constitute a novel target for the treatment of type 2 diabetes mellitus. PMID:25941406

  2. Lifelong expression of apolipoprotein D in the human brainstem: correlation with reduced age-related neurodegeneration.

    Directory of Open Access Journals (Sweden)

    Ana Navarro

    Full Text Available The lipocalin apolipoprotein D (Apo D is upregulated in peripheral nerves following injury and in regions of the central nervous system, such as the cerebral cortex, hippocampus, and cerebellum, during aging and progression of certain neurological diseases. In contrast, few studies have examined Apo D expression in the brainstem, a region necessary for survival and generally less prone to age-related degeneration. We measured Apo D expression in whole human brainstem lysates by slot-blot and at higher spatial resolution by quantitative immunohistochemistry in eleven brainstem nuclei (the 4 nuclei of the vestibular nuclear complex, inferior olive, hypoglossal nucleus, oculomotor nucleus, facial motor nucleus, nucleus of the solitary tract, dorsal motor nucleus of the vagus nerve, and Roller`s nucleus. In contrast to cortex, hippocampus, and cerebellum, apolipoprotein D was highly expressed in brainstem tissue from subjects (N = 26, 32-96 years of age with no history of neurological disease, and expression showed little variation with age. Expression was significantly stronger in somatomotor nuclei (hypoglossal, oculomotor, facial than visceromotor or sensory nuclei. Both neurons and glia expressed Apo D, particularly neurons with larger somata and glia in the periphery of these brainstem centers. Immunostaining was strongest in the neuronal perinuclear region and absent in the nucleus. We propose that strong brainstem expression of Apo D throughout adult life contributes to resistance against neurodegenerative disease and age-related degeneration, possibly by preventing oxidative stress and ensuing lipid peroxidation.

  3. Plasma Apolipoprotein-M (ApoM Response to a Circuit Resistance Training Program

    Directory of Open Access Journals (Sweden)

    Abbass Ghanbari-Niaki

    2013-12-01

    Full Text Available Apolipoprotein M (Apo-M is a human novel protein of apolipoprotein classes and highly expressed in liver and kidney tissues. ApoM is mainly associated with high-density lipoprotein (HDL, and act as a chaperone for sphingosine-1-phosphate (S1P, promotes mobilization of cellular cholesterol, formation of larger-size of pre β-HDL, and a new biomarker in sepsis. The level of apoM in plasma/serum is affected by several factors such as pregnancy, hyperglycemia, plasma leptin concentration, obesity, diabetes, insulin concentration and physical exercise. It has been shown that the level of plasma ApoM was significantly lower in strenuous exercise group when compared with the non-exercise group. In the present study a reduction was observed after the 4 weeks of circuit resistance training program. This reduction might be due to a decrease in ApoM expression in liver and kidney or an increase in ApoM clearance, degradation and excretion in urine.

  4. Expression of human apolipoprotein B and assembly of lipoprotein(a) in transgenic mice

    Energy Technology Data Exchange (ETDEWEB)

    Callow, M.J.; Stoltzfus, L.J.; Rubin, E.M. [Lawrence Berkeley Lab., CA (United States); Lawn, R.M. [Stanford Univ., CA (United States)

    1994-03-15

    The atherogenic macromolecule lipoprotein(a) [Lp(a)] has resisted in vivo analyses partly because it is found in a limited number of experimental animals. Although transgenic mice expressing human apolipoprotein (a) [apo(a)] have previously been described, they failed to assemble Lp(a) particles because of the inability of human apo(a) to associate with mouse apolipoprotein B (apoB). The authors isolated a 90-kilobase P1 phagemid containing the human apoB gene and with this DNA generated 13 lines of transgenic mice of which 11 expressed human apoB. The human apoB transcript was expressed and edited in the liver of the transgenic mice. Plasma concentrations of human apoB, as well as low density lipoprotein (LDL), were related to transgene copy number; the transgenic line with the most copies of human apoB had a >4-fold increase in LDL cholesterol compared with nontransgenics and a lipoprotein profile similar to that of humans. When human apoB and apo(a) transgenic mice were bred together, plasma apo(a) in mice expressing both human proteins was tightly associated with lipoproteins in the LDL density region. These studies demonstrate the successful expression of human apoB and the efficient assembly of Lp(a) in mice.

  5. [Relationship between apolipoprotein E polymorphism and cognitive function in patients with primary hypertension].

    Science.gov (United States)

    Su, Yanling; Chen, Xiaoping; Huang, Yan; Jiang, Lingyun; Huang, He

    2009-08-01

    To explore the relationship between apolipoprotein E polymorphism and cognitive function in primary hypertension patients, we collected 200 Chinese primary hypertensive patients. Blood pressure (BP), heart rate (HR), height, body weight, waistline, hip circumference were measured. The Mini Mental State Examination (MMSE) was applied to test the cognitive function and compute score. Full-automatic bio-chemistry analyzer was used to determine total cholesterol (TC) and triglyeride (TG) and fasting glucose. The polymerase chain reaction-restriction fragment length polymorphism (PCR-RELP) was used for the analysis of the apolipoprotein E polymorphism. We found that in primary hypertension patients, the genotype frequency of epsilon3/4 and epsilon4/4 were significantly higher in the cognitive impairment group than that in the cognitive normal group. The allele frequency of e4 is obviously higher in the cognitive impairment group than that in the cognitive normal group. Age and epsilon4/4 genetype were positively correlated with hypertensive-cognitive impairment, while cultural level was negtively correlated with it. ApoEepsilon4 allele and age might be risk factors for the cognitive impairment in hypertensive patients. The epsilon4 homozygote (epsilon4/4) might be an important influencing factor for the progression of cognitive impairment.

  6. Ledipasvir/sofosbuvir treatment of hepatitis C virus is associated with reduction in serum apolipoprotein levels.

    Science.gov (United States)

    Younossi, Z M; Elsheikh, E; Stepanova, M; Gerber, L; Nader, F; Stamm, L M; Brainard, D M; McHutchinson, J G

    2015-12-01

    The interaction of lipoproteins with hepatitis C virus (HCV) has pathogenic and therapeutic implications. Our aim was to evaluate changes in the apolipoprotein profile of patients with chronic hepatitis C during and after successful cure with ledipasvir and sofosbuvir (LDV/SOF) with and without ribavirin (RBV). One hundred HCV genotype 1 patients who had achieved SVR-12 after treatment with 12 weeks of LDV/SOF ± RBV were selected from the ION-1 clinical trial. Frozen serum samples from baseline, end of treatment and week 4 of follow-up were used to assay apolipoproteins (apoAI, apoAII, apoB, apoCII, apoCIII, apoE) using the Multiplex platform to assess for changes in the apolipoprotein levels. At the end of treatment compared to baseline, a significant reduction in apoAII levels (-14.97 ± 63.44 μg/mL, P = 0.0067) and apoE levels (-4.38 ± 12.19 μg/mL, P < 0.001) was noted. These declines from baseline in apoAII (-16.59 ±66.15 μg/mL, P = 0.0075) and apoE (-2.66 ± 12.64 μg/mL, P = 0.015) persisted at 4 weeks of post-treatment follow-up. In multivariate analysis, treatment with LDV/SOF + RBV was independently associated with reduction in apoE (beta = 5.31 μg/mL, P = 0.002) (compared to RBV-free LDV/SOF) (P < 0.05). In contrast, apoCII levels overall increased from baseline to end of treatment (+2.74 ±11.76 μg/mL, P = 0.03) and persisted at 4 weeks of follow-up (+4.46 ± 12.81 μg/mL from baseline, P = 0.0005). Subgroup analysis revealed an increase in apoCII during treatment only in patients receiving LDV/SOF without RBV (+5.52 ± 11.92 μg/mL, P = 0.0007) but not in patients receiving LDV/SOF + RBV (P = 0.638). Treatment with LDV/SOF ± RBV is associated with a persistent reduction in the apolipoprotein AII and E after achieving cure. These data suggest that treatment with LDV/SOF ± RBV may be associated with alterations in serum apolipoproteins which could potentially impact viral eradication.

  7. Epigenetic effectiveness of complete carcinogens: specific interactions of polycyclic aromatic hydrocarbons and aminoazo dyes with cholesterol and apolipoprotein A-I.

    Science.gov (United States)

    Contag, Bodo

    2005-01-01

    During a co-precipitation of cholesterol (Chol) and slight amounts of polycyclic aromatic hydrocarbons (PAHs) or aminoazo dyes (AZOs) in aqueous albumin solution, complex particles are formed; on their surfaces apolipoproteins with an amphipathic alpha-helix (e.g. apoA-I) are more or less firmly adsorbed. An efficacy index can be calculated from the strength of the hydrophobic interactions between apoA-I and the [Chol/PAH]- or [Chol/AZO]-complex, and the solubility of the PAH or AZO in an aqueous medium, which correlates to the carcinogenicity of these compounds. A short-term test for PAHs and AZOs is described, in which the efficacy index can be determined in the simplest manner without any great expenditure on equipment. The previous results suggest that the parent compounds of the PAHs and AZOs can be involved in a specific interaction with cholesterol-domains of the plasma membrane of a cell. The changes in membrane fluidity and architecture caused by these specific interactions could modulate the distribution and/or activity of membrane proteins which are critical to the regulation of cellular proliferation.

  8. Changes in epitope exposition of apolipoprotein A-I on the surface of high density lipoproteins after phospholipase A2 treatment.

    Science.gov (United States)

    Menschikowski, M; Hempel, U; Dinnebier, G; Lattke, P; Wenzel, K W; Jaross, W

    1995-10-01

    The immunoreactivity of high density lipoprotein (HDL) modified by treatment with porcine pancreatic phospholipase A2 (PLA2) was studied in a competitive radioimmunoassay using 6 different monoclonal apolipoprotein (apo) A-I antibodies. The competition tests have shown that after PLA2 treatment the immunoreactivity of selected epitopes of apo A-I changed in different ways. While the binding behavior of two epitopes remained unchanged, three epitopes exhibited decreased immunoreactivities after phospholipids hydrolysis. In contrast to the latter epitopes, the immunoreactivity of an epitope located on the cyanogen bromide fragment 4 of apo A-I increased with the degree of lipolysis. A loss of apo A-I from HDL as a consequence of PLA2-treatment did not occur as shown by the determination of the apo A-I concentration in HDL before and after treatment with PLA2. Using overlapped synthetic decapeptides it could be shown that the epitope increasingly exposed on the particle surface of PLA2-modified HDL consists of the amino acid residues 162-173 and 212-229. These residues are characterized by high hydrophobic indices as determined by hydropathy analysis. Furthermore, these regions belong partially to the proposed receptor-binding domain of apo A-I. Thus, an increased exposition of this epitope might result in elevated cellular binding affinities of HDL occurring after modification of lipoproteins by PLA2-treatment.

  9. The effect of an energy restricted low glycemic index diet on blood lipids, apolipoproteins and lipoprotein (a) among adolescent girls with excess weight: a randomized clinical trial.

    Science.gov (United States)

    Rouhani, Mohammad Hossein; Kelishadi, Roya; Hashemipour, Mahin; Esmaillzadeh, Ahmad; Azadbakht, Leila

    2013-12-01

    Some studies focused on the effect of the dietary glycemic index on lipoproteins and apolipoproteins in adults; however, little evidence exists among adolescents regarding the effect of a low glycemic index (LGI) diet on apolipoproteins and lipoprotein (a) (Lpa). This study was conducted to evaluate the effect of an LGI diet on the lipid profile, apolipoproteins and Lpa among overweight and obese adolescent girls. For this parallel designed randomized clinical trial, 50 healthy overweight/obese girls at pubertal ages were randomly allocated to an LGI or a healthy nutritional recommendations (HNR) based diet. Equal macronutrient distributed diets were prescribed to both groups. Biochemical measurements included lipid profile, apolipoprotein A, apolipoprotein B and Lpa were conducted before and after 10 weeks of intervention. Forty one adolescent girls completed the study. The dietary glycemic index in the LGI group was 42.67 ± 0.067. There were no differences in the mean of blood lipid indices baseline and after intervention between two groups. There were no significant differences between the two groups regarding lipid profiles, apolipoproteins and Lpa. There were no significant differences in lipid profiles, apolipoproteins and Lpa between the LGI diet and the HNR-based diet and the impact of these two diets on lipid profile was equal in this trial.

  10. Apolipoprotein A-IV inhibits AgRP/NPY neurons and activates POMC neurons in the arcuate nucleus

    Science.gov (United States)

    Apolipoprotein A-IV (apoA-IV) in the brain potently suppresses food intake. However the mechanisms underlying its anorexigenic effects remain to be identified. We first examined the effects of apoA-IV on cellular activities in hypothalamic neurons that co-express agouti-related peptide (AgRP) and ne...

  11. Apolipoprotein E genotype status affects habitual human blood mononuclear cell gene expression and its response to fish oil intervention

    NARCIS (Netherlands)

    Matualatupauw, J.C.; Radonjic, M.; Rest, van de O.; Groot, de C.P.G.M.; Geleijnse, J.M.; Müller, M.R.; Afman, L.A.

    2016-01-01

    Scope
    People who carry the apolipoprotein E4 (APOE4) single nucleotide polymorphism have an increased risk of cardiovascular disease (CVD). Fish-oil supplementation may help in the prevention of CVD, though interindividual differences in the response to n-3 PUFAs have been observed. We aimed to

  12. Effects of dietary fish oil on serum lipids and VLDL kinetics in hyperlipidemic apolipoprotein E*3-Leiden transgenic mice

    NARCIS (Netherlands)

    Vlijmen, B.J.M. van; Mensink, R.P.; Hof, H.B. van 't; Offermans, R.F.G.; Hofker, M.H.; Havekes, L.M.

    1998-01-01

    Studying the effects of dietary fish oil on VLDL metabolism in humans is subject to both large intra- and interindividual variability. In the present study we therefore used hyperlipidentic apolipoprotein (APO) E*3-Leiden mice, which have impaired chylomicron and very low density lipoprotein (VDL) r

  13. Risk estimates of dementia by apolipoprotein E genotypes from a population-based incidence study: the Rotterdam Study

    NARCIS (Netherlands)

    A.J.C. Slooter (Arjen); M. Cruts (Marc); S. Kalmijn (Sandra); M.M.B. Breteler (Monique); C.M. van Duijn (Cock); C. van Broeckhoven (Christine); A. Hofman (Albert)

    1998-01-01

    textabstractOBJECTIVES: To provide risk estimates of dementia and Alzheimer disease as a function of the apolipoprotein E (APOE) genotypes and to assess the proportion of dementia that is attributable to the APOE genotypes. DESIGN: Case-control study nested in a population-based cohort study with a

  14. Apolipoprotein A2 polymorphism interacts with intakes of dairy foods to influence body weight in 2 U.S. populations

    Science.gov (United States)

    The interaction between a functional apolipoprotein A2 gene (APOA2) variant and saturated fatty acids (SFAs) for the outcome of body mass index (BMI) is among the most widely replicated gene-nutrient interactions. Whether this interaction can be extrapolated to food-based sources of SFAs, specifical...

  15. Apolipoprotein A4-1/2 polymorphism and response of serum lipids to dietary cholesterol in humans

    NARCIS (Netherlands)

    Weggemans, R.M.; Zock, P.L.; Meyboom, S.; Funke, H.; Katan, M.B.

    2000-01-01

    The response of serum lipids to dietary changes is to some extent an innate characteristic. One candidate genetic factor that may affect the response of serum lipids to a change in cholesterol intake is variation in the apolipoprotein A4 gene, known as the APOA4-1/2 or apoA-IVGln360His polymorphism.

  16. Lipid profiles reflecting high and low risk for coronary heart disease : Contribution of apolipoprotein E polymorphism and lifestyle

    NARCIS (Netherlands)

    Boer, J.M.A.; Feskens, E.J.M.; Schouten, E.G.; Havekes, L.M.; Seidell, J.C.; Kromhout, D.

    1998-01-01

    To elucidate the role of modifiable factors and the apolipoprotein E polymorphism in explaining lipid profiles reflecting low, average and high risk for coronary heart disease, we selected subjects from a large population-based study. Subjects with low total cholesterol (TC) (< 15th percentile) and

  17. High-salt diet combined with elevated angiotensin II accelerates atherosclerosis in apolipoprotein E-deficient mice

    DEFF Research Database (Denmark)

    Johansson, Maria E; Bernberg, Evelina; Andersson, Irene J

    2009-01-01

    to atherosclerosis. METHODS: Apolipoprotein E-deficient (ApoE-/-) mice received standard or high-salt diet (8%) alone or in combination with fixed angiotensin II (Ang II) infusion (0.5 microg/kg per min). BP was measured using telemetry, and plaque burden was assessed in the thoracic aorta and innominate artery. We...

  18. Variations in apolipoprotein e frequency with age in a pooled analysis of a large group of older people

    NARCIS (Netherlands)

    G.J. McKay (Gareth); G. Silvestri (Giuliana); U. Chakravarthy (Usha); S. Dasari (Shilpa); L.G. Fritsche (Lars); B.H.F. Weber (Bernhard); P.J. Francis (Peter); C.N. Keilhauer (Claudia); M.L. Klein (Michael); C.C.W. Klaver (Caroline); J.R. Vingerling (Hans); L. Ho (Lintje); P.T.V.M. de Jong (Paulus); M. Dean (Michael Emmans); J. Sawitzke (Julie); P.N. Baird (Paul); R.H. Guymer (Robyn); D.E. Stambolian (Dwight); A. Orlin (Anton); J.M. Seddon (Johanna); I. Peter (Inga); A.F. Wright (Alan); C. Hayward (Caroline); A.J. Lotery (Andrew); S. Ennis (Sarah); M.B. Gorin (Michael); C.-L. Kuo; A. Hingorani (Aroon); R. Sofat (Reecha); F. Cipriani (Francesco); A. Swaroop (Anand); M.I. Othman (Mohammad); A. Kanda (Atsuhiro); W. Chen (Wei); G.R. Abecasis (Gonçalo); J.R. Yates (John); A.R. Webster (Andrew); A.T. Moore (Anthony); J.H. Seland (Johan ); M. Rahu (Mati); G. Soubrane (Gisele); L. Tomazzoli (Laura); F. Topouzis (Fotis); J. Vioque (Jesus); I.S. Young (Ian); A.E. Fletcher (Astrid E.); C.C. Patterson (Chris); D.E. Weeks (Daniel)

    2011-01-01

    textabstractVariation in the apolipoprotein E gene (APOE) has been reported to be associated with longevity in humans. The authors assessed the allelic distribution of APOE isoforms ε2, ε3, and ε4 among 10,623 participants from 15 case-control and cohort studies of age-related macular degeneration (

  19. Apolipoprotein E genotype status affects habitual human blood mononuclear cell gene expression and its response to fish oil intervention

    NARCIS (Netherlands)

    Matualatupauw, J.C.; Radonjic, M.; Rest, O. van de; Groot, L.C.P.G.M. de; Geleijnse, J.M.; Müller, M.; Afman, L.A.

    2016-01-01

    Scope: People who carry the apolipoprotein E4 (APOE4) single nucleotide polymorphism have an increased risk of cardiovascular disease (CVD). Fish-oil supplementation may help in the prevention of CVD, though interindividual differences in the response to n-3 PUFAs have been observed. We aimed to ass

  20. The concentration of apolipoprotein A-I decreases during experimentally induced acute-phase processes in pigs

    DEFF Research Database (Denmark)

    Carpintero, R.; Pineiro, M.; Andres, M.

    2005-01-01

    In this work, apolipoprotein A-I (ApoA-I) was purified from pig sera. The responses of this protein after sterile inflammation and in animals infected with Actinobacillus pleuropneumoniae or Streptococcus suis were investigated. Decreases in the concentrations of ApoA-I, two to five times lower...

  1. Apolipoprotein A5 deficiency aggravates high-fat diet-induced obesity due to impaired central regulation of food intake

    NARCIS (Netherlands)

    Berg, S.A.A. van den; Heemskerk, M.M.; Geerling, J.J.; Klinken, J.B. van; Schaap, F.G.; Bijland, S.; Berbée, J.F.P.; Harmelen, V.J.A. van; Pronk, A.C.M.; Schreurs, M.; Havekes, L.M.; Rensen, P.C.N.; Dijk, K.W. van

    2013-01-01

    Mutations in apolipoprotein A5 (APOA5) have been associated with hypertriglyceridemia in humans and mice. This has been attributed to a stimulating role for APOA5 in lipoprotein lipase-mediated triglyceride hydrolysis and hepatic clearance of lipoprotein remnant particles. However, because of the lo

  2. Effect of an isoenergetic traditional Mediterranean diet on apolipoprotein A-I kinetic in men with metabolic syndrome

    Science.gov (United States)

    The impact of the Mediterranean diet (MedDiet) on high-density lipoprotein (HDL) kinetics has not been studied to date. The objective of this study was therefore to investigate the effect of the MedDiet in the absence of changes in body weight on apolipoprotein (apo) A-I kinetic in men with metaboli...

  3. Effect of Mediterranean diet with and without weight loss on apolipoprotein B100 metabolism in men with metabolic syndrome

    Science.gov (United States)

    The objective of this study was to assess the effect of a Mediterranean diet (MedDiet) with and without weight loss (WL) on apolipoprotein B100 (apoB100) metabolism in men with metabolic syndrome. The diet of 19 men with metabolic syndrome (age, 24–62 years) was first standardized to a North America...

  4. 9-CIS-RETINOIC ACID REPRESSES ESTROGEN-INDUCED EXPRESSION OF THE VERY-LOW-DENSITY APOLIPOPROTEIN-II GENE

    NARCIS (Netherlands)

    SCHIPPERS, IJ; KLOPPENBURG, M; SNIPPE, L; AB, G

    1994-01-01

    The chicken very low density apolipoprotein II (apoVLDLII) gene is estrogen-inducible and specifically expressed in liver. We examined the possible involvement of the retinoid X receptor (RXR) and its ligand 9-cis-retinoic acid (9-cis-RA) in the activation of the apoVLDLII promoter. We first concent

  5. Shape design sensitivity analysis using domain information

    Science.gov (United States)

    Seong, Hwal-Gyeong; Choi, Kyung K.

    1985-01-01

    A numerical method for obtaining accurate shape design sensitivity information for built-up structures is developed and demonstrated through analysis of examples. The basic character of the finite element method, which gives more accurate domain information than boundary information, is utilized for shape design sensitivity improvement. A domain approach for shape design sensitivity analysis of built-up structures is derived using the material derivative idea of structural mechanics and the adjoint variable method of design sensitivity analysis. Velocity elements and B-spline curves are introduced to alleviate difficulties in generating domain velocity fields. The regularity requirements of the design velocity field are studied.

  6. Differential interaction of Apolipoprotein-E isoforms with insulin receptors modulates brain insulin signaling in mutant human amyloid precursor protein transgenic mice.

    Science.gov (United States)

    Chan, Elizabeth S; Chen, Christopher; Cole, Gregory M; Wong, Boon-Seng

    2015-09-08

    It is unclear how human apolipoprotein E4 (ApoE4) increases the risk for Alzheimer's disease (AD). Although Aβ levels can lead to insulin signaling impairment, these experiments were done in the absence of human ApoE. To examine ApoE role, we crossed the human ApoE-targeted replacement mice with mutant human amyloid precursor protein (APP) mice. In 26 week old mice with lower Aβ levels, the expression and phosphorylation of insulin signaling proteins remained comparable among APP, ApoE3xAPP and ApoE4xAPP mouse brains. When the mice aged to 78 weeks, these proteins were markedly reduced in APP and ApoE4xAPP mouse brains. While Aβ can bind to insulin receptor, how ApoE isoforms modulate this interaction remains unknown. Here, we showed that ApoE3 had greater association with insulin receptor as compared to ApoE4, regardless of Aβ42 concentration. In contrast, ApoE4 bound more Aβ42 with increasing peptide levels. Using primary hippocampal neurons, we showed that ApoE3 and ApoE4 neurons are equally sensitive to physiological levels of insulin. However, in the presence of Aβ42, insulin failed to elicit a downstream response only in ApoE4 hippocampal neurons. Taken together, our data show that ApoE genotypes can modulate this Aβ-mediated insulin signaling impairment.

  7. Apolipoprotein D is involved in the mechanisms regulating protection from oxidative stress.

    Science.gov (United States)

    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

    2008-08-01

    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 protective 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 overexpression 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.

  8. Genetic vulnerability following traumatic brain injury: the role of apolipoprotein E.

    Science.gov (United States)

    Nathoo, N; Chetty, R; van Dellen, J R; Barnett, G H

    2003-06-01

    Apolipoprotein E (APOE) is thought to be responsible for the transportation of lipids within the brain, maintaining structural integrity of the microtubule within the neurone, and assisting with neural transmission. Possession of the APOE epsilon4 allele has also been shown to influence neuropathological findings in patients who die from traumatic brain injury, including the accumulation of amyloid beta protein. Previous clinical studies reporting varying outcome severities of traumatic brain injury, including cognitive and functional recovery, all support the notion that APOE epsilon4 allele possession is associated with an unfavourable outcome. Evidence from experimental and clinical brain injury studies confirms that APOE plays an important role in the response of the brain to injury.

  9. Study on relationship of apolipoprotein E gene polymorphism and genetic susceptibility of stress urinary incontinence

    Institute of Scientific and Technical Information of China (English)

    Tong Jia-li; Lang Jing-he; Zhu lan

    2010-01-01

    Objective: To explore the relationship between apolipoprotein E (ApoE) gene polymorphism and susceptibility of stress urinary incontinence (SUI).Methods: ApoE genotypes were examined by polymerase chain reaction-restricted fragment length polymorphism (PCR-RFLP) technique in 99 patients with SUI and 101 asymptomatic controls. Results: The frequency of allele e3 of ApoE was slightly lower in patients with anatomic SUI than that in controls (79.44% vs. 81.68%), while the frequency of allele e4 of ApoE was slightly higher in patients with anatomic SUI than that in controls (10.00% vs. 9.90%). No significant difference was found in frequency of allele e3 or e4 between SUI patients and controls (χ2=0.523, P=0.770).Conclusion: The gene polymorphism of ApoE is not independently involved in the development of SUI.

  10. Apolipoprotein E gene polymorphism in cerebrovascular diseases of the Chinese Naxi populations from Yunnan province

    Institute of Scientific and Technical Information of China (English)

    Hong Xu; Qihong Yuan; Xijun Fan; Guoqiang He

    2011-01-01

    Currently it is not well known whether apolipoprotein E (ApoE) is a genetic susceptibility factor for cerebrovascular diseases in the Chinese Naxi population. The present study detected and sequenced ApoE polymorphisms of 90 patients with cerebrovascular diseases (58 cases of cerebral infarction and 32 cases of intracerebral hemorrhage), and 50 normal people of Naxi nationality from Yunnan province, China. The populations were used to analyze the relationship of ApoE polymorphisms with cerebral infarction and intracerebral hemorrhage. Results showed an association between ApoE gene polymorphism and the onset of cerebral infarction, and a possibility that the ε4 allele is a susceptibility locus for the risk of cerebral infarction. However, there was no evidence of a relationship between the ApoE gene polymorphism and cerebral hemorrhage.

  11. Plasma levels of apolipoprotein E and risk of dementia in the general population

    DEFF Research Database (Denmark)

    Rasmussen, Katrine L.; Tybjaerg-Hansen, Anne; Nordestgaard, Børge G;

    2015-01-01

    whether low plasma levels of apoE at study enrollment were associated with increased risk of future Alzheimer disease and all dementia, and whether this association was independent of ε2/ε3/ε4 APOE genotype. RESULTS: Multifactorially adjusted hazard ratios (HRs) for Alzheimer disease and all dementia......OBJECTIVE: The apolipoprotein E (APOE) ε4 allele is a major genetic risk factor for Alzheimer disease and dementia. However, it remains unclear whether plasma levels of apoE confer additional risk. We tested this hypothesis. METHODS: Using 75,708 participants from the general population, we tested...... increased from the highest to the lowest apoE tertile (p for trends dementia, respectively. After further...

  12. Parental vitamin deficiency affects the embryonic gene expression of immune-, lipid transport- and apolipoprotein genes

    Science.gov (United States)

    Skjærven, Kaja H.; Jakt, Lars Martin; Dahl, John Arne; Espe, Marit; Aanes, Håvard; Hamre, Kristin; Fernandes, Jorge M. O.

    2016-10-01

    World Health Organization is concerned for parental vitamin deficiency and its effect on offspring health. This study examines the effect of a marginally dietary-induced parental one carbon (1-C) micronutrient deficiency on embryonic gene expression using zebrafish. Metabolic profiling revealed a reduced 1-C cycle efficiency in F0 generation. Parental deficiency reduced the fecundity and a total of 364 genes were differentially expressed in the F1 embryos. The upregulated genes (53%) in the deficient group were enriched in biological processes such as immune response and blood coagulation. Several genes encoding enzymes essential for the 1-C cycle and for lipid transport (especially apolipoproteins) were aberrantly expressed. We show that a parental diet deficient in micronutrients disturbs the expression in descendant embryos of genes associated with overall health, and result in inherited aberrations in the 1-C cycle and lipid metabolism. This emphasises the importance of parental micronutrient status for the health of the offspring.

  13. Protein domain prediction

    NARCIS (Netherlands)

    Ingolfsson, Helgi; Yona, Golan

    2008-01-01

    Domains are considered to be the building blocks of protein structures. A protein can contain a single domain or multiple domains, each one typically associated with a specific function. The combination of domains determines the function of the protein, its subcellular localization and the interacti

  14. Serum apolipoproteins in relation to intakes of fish in population of Arkhangelsk County

    Directory of Open Access Journals (Sweden)

    Petrenya Natalia

    2012-06-01

    Full Text Available Abstract Background Diets rich in omega-3 fatty acids and low in saturated fat were found beneficially associated with blood lipids and cardio-vascular health. Lean reindeer meet and local cold water white-fish species high in omega-3 are among the main sources of nutrients in the rural area of the Nenets Autonomous Okrug (NAO in Russia and are not normally consumed by the urban population from the same region. The aims of the study were firstly, to compare serum lipid profiles of residents of urban (Arkhangelsk city and rural (NAO regions of Arkhangelsk County, and secondly, to investigate the effects of fish consumption on the predictor of cardiovascular events apolipoprotein (Apo B/ApoA-I ratio in these populations. Methods A cross-sectional study conducted in Arkhangelsk County, Russia. Sample size of 249 adults: 132 subjects from Arkhangelsk city, aged 21–70 and 117 subject (87% Ethnic Nenets from NAO, aged 18–69. Results We observed more favorable lipid levels in NAO compared to Arkhangelsk participants. Age-adjusted geometric means of ApoB/ApoA-I ratio were 1.02 and 0.98 in men and women from Arkhangelsk; 0.84 and 0.91 in men and women from NAO respectively. Age and consumption of animal fat were positively associated with ApoB/ApoA-I ratio in women (pooled samples from Arkhangelsk and NAO. Body mass index and low levels of physical activity were positively associated with ApoB/ApoA-I ratio in men (pooled samples from Arkhangelsk and NAO. Reported oily fish consumption was not significantly correlated with ApoB/ApoA-I ratio. Conclusion The population sample from rural NAO, consisting largely of the indigenous Arctic population Nenets with healthier dietary sources, had a relatively less atherogenic lipid profile compared to the urban Arkhangelsk group. Fish consumption had no effect on apolipoproteins profile.

  15. Apolipoprotein C3 polymorphisms, cognitive function and diabetes in Caribbean origin Hispanics.

    Directory of Open Access Journals (Sweden)

    Caren E Smith

    Full Text Available Apolipoprotein C3 (APOC3 modulates triglyceride metabolism through inhibition of lipoprotein lipase, but is itself regulated by insulin, so that APOC3 represents a potential mechanism by which glucose metabolism may affect lipid metabolism. Unfavorable lipoprotein profiles and impaired glucose metabolism are linked to cognitive decline, and all three conditions may decrease lifespan. Associations between apolipoprotein C3 (APOC3 gene polymorphisms and impaired lipid and glucose metabolism are well-established, but potential connections between APOC3 polymorphisms, cognitive decline and diabetes deserve further attention.We examined whether APOC3 single nucleotide polymorphisms (SNPs m482 (rs2854117 and 3u386 (rs5128 were related to cognitive measures, whether the associations between cognitive differences and genotype were related to metabolic differences, and how diabetes status affected these associations. Study subjects were Hispanics of Caribbean origin (n = 991, aged 45-74 living in the Boston metropolitan area.Cognitive and metabolic measures differed substantially by type II diabetes status. In multivariate regression models, APOC3 m482 AA subjects with diabetes exhibited lower executive function (P = 0.009, Stroop color naming score (P = 0.014 and Stroop color-word score (P = 0.022 compared to AG/GG subjects. APOC3 m482 AA subjects with diabetes exhibited significantly higher glucose (P = 0.032 and total cholesterol (P = 0.028 compared to AG/GG subjects. APOC3 3u386 GC/GG subjects with diabetes exhibited significantly higher triglyceride (P = 0.004, total cholesterol (P = 0.003 and glucose (P = 0.016 compared to CC subjects.In summary, we identified significant associations between APOC3 polymorphisms, impaired cognition and metabolic dysregulation in Caribbean Hispanics with diabetes. Further research investigating these relationships in other populations is warranted.

  16. Comparison of Serum Apolipoprotein Levels of Diabetic Children and Healthy Children with or without Diabetic Parents

    Directory of Open Access Journals (Sweden)

    Mohammad Hashemi

    2012-01-01

    Full Text Available Introduction. The association of diabetes and atherosclerosis with disorders of lipids and lipoproteins, notably high apolipoprotein B (apoB and low apolipoprotein A1(apoA1 is well established. Because of the beginning of the atherosclerosis' process from early life, in this study, the plasma levels of apoA1 and apoB were compared in diabetic children with type I diabetes mellitus(DM, healthy children with diabetic parents (HDPs,and healthy children with nondiabetic parents (HNDPs. Methods. This case-control study was conducted among 90 children aged 9–18 years. Serum levels of apoA and apoB were compared among 30 diabetic children (DM, 30 healthy children with diabetic parents (HDPs, and 30 healthy children with nondiabetic parents (HNDP. Results. The mean serum apoA1 was higher in DM (153±69 mg/dL followed by HNDPs (138±58 mg/dL and HDPs (128±56 mg/dl, but the difference was not statistically significant. The mean apoB value in HNDPs was significantly lower than DM and HDPs (90±21 mg/dL versus 127±47 and 128±38 mg/dL, P0.05. Conclusions. Diabetic children and healthy children with diabetic parent(s are at higher risk of dyslipidemia and atherosclerosis. Thus for primordial and primary prevention of atherosclerosis, we suggest screening these children for low plasma apoA1 and high plasma apoB levels.

  17. Secretion of hepatitis C virus envelope glycoproteins depends on assembly of apolipoprotein B positive lipoproteins.

    Directory of Open Access Journals (Sweden)

    Vinca Icard

    Full Text Available The density of circulating hepatitis C virus (HCV particles in the blood of chronically infected patients is very heterogeneous. The very low density of some particles has been attributed to an association of the virus with apolipoprotein B (apoB positive and triglyceride rich lipoproteins (TRL likely resulting in hybrid lipoproteins known as lipo-viro-particles (LVP containing the viral envelope glycoproteins E1 and E2, capsid and viral RNA. The specific infectivity of these particles has been shown to be higher than the infectivity of particles of higher density. The nature of the association of HCV particles with lipoproteins remains elusive and the role of apolipoproteins in the synthesis and assembly of the viral particles is unknown. The human intestinal Caco-2 cell line differentiates in vitro into polarized and apoB secreting cells during asymmetric culture on porous filters. By using this cell culture system, cells stably expressing E1 and E2 secreted the glycoproteins into the basal culture medium after one week of differentiation concomitantly with TRL secretion. Secreted glycoproteins were only detected in apoB containing density fractions. The E1-E2 and apoB containing particles were unique complexes bearing the envelope glycoproteins at their surface since apoB could be co-immunoprecipitated with E2-specific antibodies. Envelope protein secretion was reduced by inhibiting the lipidation of apoB with an inhibitor of the microsomal triglyceride transfer protein. HCV glycoproteins were similarly secreted in association with TRL from the human liver cell line HepG2 but not by Huh-7 and Huh-7.5 hepatoma cells that proved deficient for lipoprotein assembly. These data indicate that HCV envelope glycoproteins have the intrinsic capacity to utilize apoB synthesis and lipoprotein assembly machinery even in the absence of the other HCV proteins. A model for LVP assembly is proposed.

  18. Apolipoprotein E alleles in Alzheimer`s and Parkinson`s patients

    Energy Technology Data Exchange (ETDEWEB)

    Poduslo, S.E. [Texas Tech Univ., Lubbock, TX (United States); Schwankhaus, J.D. [Department of Veterans Affairs, Lubbock, TX (United States)

    1994-09-01

    A number of investigators have found an association between the apolipoprotein E4 allele and Alzheimer`s disease. The E4 allele appears at a higher frequency in late onset familial Alzheimer`s patients. In our studies we obtained blood samples from early and late onset familial and sporadic Alzheimer`s patients and spouses, as well as from Parkinson`s patients. The patients were diagnosed as probable Alzheimer`s patients after a neurological examination, extensive blood work, and a CAT scan. The diagnosis was made according to the NINCDS-ADRDA criteria. The apolipoprotein E4 polymorphism was detected after PCR amplification of genomic DNA, restriction enzyme digestion with Hhal, and polyacrylamide gel electrophoresis. Ethidium bromide-stained bands at 91 bp were designated as allele 3, at 83 bp as allele 2, and at 72 bp as allele 4. Of the 84 probable Alzheimer`s patients (all of whom were Caucasian), 47 were heterozygous and 13 were homozygous for the E4 allele. There were 26 early onset patients; 13 were heterozygous and 7 homozygous for the E4 allele. The frequencies for the E4 allele for late onset familial patients was 0.45 and for sporadic patients was 0.37. We analyzed 77 spouses with an average age of 71.9 {plus_minus} 7.4 years as controls, and 15 were heterozygous for the E4 allele for an E4 frequency of 0.097. Of the 53 Parkinson`s patients, 11 had the E4 allele for a frequency of 0.113. Thus our findings support the association of the ApoE4 allele with Alzheimer`s disease.

  19. Tryptophan probes reveal residue-specific phospholipid interactions of apolipoprotein C-III.

    Science.gov (United States)

    Pfefferkorn, Candace M; Walker, Robert L; He, Yi; Gruschus, James M; Lee, Jennifer C

    2015-11-01

    Apolipoproteins are essential human proteins for lipid metabolism. Together with phospholipids, they constitute lipoproteins, nm to μm sized particles responsible for transporting cholesterol and triglycerides throughout the body. To investigate specific protein-lipid interactions, we produced and characterized three single-Trp containing apolipoprotein C-III (ApoCIII) variants (W42 (W54F/W65F), W54 (W42F/W65F), W65 (W42F/W54F)). Upon binding to phospholipid vesicles, wild-type ApoCIII adopts an α-helical conformation (50% helicity) as determined by circular dichroism spectroscopy with an approximate apparent partition constant of 3×10(4) M(-1). Steady-state and time-resolved fluorescence measurements reveal distinct residue-specific behaviors with W54 experiencing the most hydrophobic environment followed by W42 and W65. Interestingly, time-resolved anisotropy measurements show a converse trend for relative Trp mobility with position 54 being the least immobile. To determine the relative insertion depths of W42, W54, and W65 in the bilayer, fluorescence quenching experiments were performed using three different brominated lipids. W65 had a clear preference for residing near the headgroup while W54 and W42 sample the range of depths ~8-11 Å from the bilayer center. On average, W54 is slightly more embedded than W42. Based on Trp spectral differences between ApoCIII binding to phospholipid vesicles and sodium dodecyl sulfate micelles, we suggest that ApoCIII adopts an alternate helical conformation on the bilayer which could have functional implications.

  20. Apolipoprotein J: A New Predictor and Therapeutic Target in Cardiovascular Disease?

    Institute of Scientific and Technical Information of China (English)

    Ning Yang; Qin Qin

    2015-01-01

    Objective:To review the functional mechanism of apolipoprotein J (apoJ) in the process of atherosclerosis and the feasibility of apoJ as a therapeutic endpoint.Data Sources:Relevant articles published in English from 1983 to present were selected from PubMed.The terms of"atherosclerosis,apolipoprotein J,clusterin (CLU),oxidative stress,and inflammation" were used for searching.Study Selection:Articles studying the role of apoJ with atherosclerosis and restenosis after injury were reviewed.Articles focusing on the intrinsic determinants of atherosclerosis were selected.The exclusion criteria of articles were that the studies on immunologic vasculitis.Results:ApoJ,involved in numerous physiological process important for lipid transportation and vascular smooth muscle cell differentiation,including apoptotic cell death,cell-cycle regulation,cell adhesion,tissue remodeling,immune system regulation,and oxidative stress,plays a role in the development of clinical atherosclerosis.In the process of relieving atherosclerosis,apoJ can promote cholesterol and phospholipid export from macrophage-foam cells,and exhibit cytoprotective and anti-inflammatory actions by interacting with lots of known inflammatory proteins which may predict the onset of clinical cardiovascular events and may actually play a causal role in mediating atherosclerotic disease such as C-reactive protein,paraoxonase,and leptin.As known as CLU,apoJ has been identified to play central roles in the process of vascular smooth cells migration,adhesion,and proliferation,which can contribute significantly to restenosis after vascular injury.Conclusions:Intense effort and substantial progress have been made to identify the apoJ that relieves atherosclerosis and vascular restenosis after percutaneous coronary intervention.More work is needed to elucidate the exact mechanisms of and the interrelationship between the actions of apoJ and to successfully achieve regression of atherosclerosis by regarding it as a

  1. Tissue sites of degradation of high density lipoprotein apolipoprotein A-IV in rats

    Energy Technology Data Exchange (ETDEWEB)

    Dallinga-Thie, G.M.; Van ' t Hooft, F.M.; Van Tol, A.

    1986-05-01

    The in vivo metabolism of high density lipoprotein (HDL), labeled by incorporation of /sup 125/I-apolipoprotein (apo) A-IV, was studied in the rat and compared with the metabolism of HDL labeled with 131I-apo A-I. The /sup 125/I-apo A-IV labeled HDL was obtained by adding small amounts of radioiodinated apo A-IV to rat serum, followed by separation of the different lipoprotein fractions by chromatography on 6% agarose columns in order to avoid stripping of apolipoproteins by ultracentrifugation. Under both in vitro and in vivo conditions, the /sup 125/I-apo A-IV remained an integral component of HDL and was not exchanged to other lipoproteins, including the free apo A-IV fraction. The serum half-life, measured at between 8 and 28 hours after intravenous injection of labeled HDL, was 8.5 +/- 0.5 hours for HDL apo A-IV and 10.2 +/- 0.7 hours for HDL apo A-I. The tissue sites of catabolism of HDL apo A-IV and HDL apo A-I were analyzed in the leupeptin-model. Only the kidneys and liver showed a significant leupeptin-dependent accumulation of radioactivity. At 4 hours after injection of 125I-apo A-IV/131I-apo A-I labeled HDL, 3.5% +/- 1.0% and 8.4% +/- 2.0% of HDL apo A-IV and 4.6% +/- 1.3% and 2.6% +/- 0.6% of the HDL apo A-I were accumulated in a leupeptin-dependent process in the kidneys and liver, respectively. Immunocytochemical studies revealed that the renal localization of apo A-IV was intracellular and confined to the epithelial cells of the proximal tubuli.

  2. Distribution of apolipoprotein E gene polymorphism in students and in high-educated elderly from Serbia

    Directory of Open Access Journals (Sweden)

    Maksimović Nela

    2013-01-01

    Full Text Available Apolipoprotein E (ApoE play important role in lipid metabolism and in processes of remodeling and reparation in central nervous system. Three common ApoE isoforms, ApoE2, ApoE3 and ApoE4, show strong genetic determination by ε2, ε3, and ε4 allele. In human genome gene encoding Apolipoprotein E (APOE is located on cromosome 19, and ε2/ε3/ε4 haplotype system is defined by 2 non-synonymous single nucleotide polymorphisms (SNPs in the APOE exon 4. The frequency of the three APOE alleles and corresponding genotypes varies across human populations, with possible clinical implications. At least, variable distribution of ε4 allele may contribute to the regional risk of cardiovascular and Alzheimer’s diseases. Allele-frequency comparisons between younger and older populations suggest an effect of APOE on mortality, but these data are not consistently confirmed. In the present study we have analyzed the distribution of APOE gene polymorphism in a group of University students and retained University professors living in Serbia. After DNA extraction from peripheral blood samples, the APOE genotype was determined by polymerase chain reaction (PCR followed with HhaI restriction digestion. We found no statistically significant difference in alleles and genotypes distribution between younger and elder group of participants. Also, there was no significant difference compared to APOE data previously obtained in YUSAD cohort of healthy school children (15 y of age from different regions of Serbia. In both of our groups, as well as in YUSAD cohort, frequency of APOE ε4 allele was <10%. The observed frequencies are lower than in neighboring countries, but similar with Spanish data and some Asian populations. Our results do not support important role of APOE ε4 in the morbidity and mortality in Serbian population, but gene-environmental-social interactions should be considered. [Projekat Ministarstva nauke Republike Srbije, br. ON175091

  3. A non-invasive, rapid method to genotype late-onset Alzheimer’s disease-related apolipoprotein E gene polymorphisms

    Institute of Scientific and Technical Information of China (English)

    Li Yi; Ting Wu; Wenyuan Luo; Wen Zhou; Jun Wu

    2014-01-01

    The apolipoprotein E geneε4 allele is considered a negative factor for neural regeneration in late-onset Alzheimer’s disease cases. The aim of this study was to establish a non-invasive, rapid method to genotype apolipoprotein E gene polymorphisms. Genomic DNA from mouth swab specimens was extracted using magnetic nanoparticles, and genotyping was performed by real-time PCR using TaqMan-BHQ probes. Genotyping accuracy was validated by DNA se-quencing. Our results demonstrate 100%correlation to DNA sequencing, indicating reliability of our protocol. Thus, the method we have developed for apolipoprotein E genotyping is accurate and reliable, and also suitable for genotyping large samples, which may help determine the role of the apolipoprotein Eε4 allele in neural regeneration in late-onset Alzheimer’s disease cases.

  4. Membrane binding domains

    OpenAIRE

    Hurley, James H.

    2006-01-01

    Eukaryotic signaling and trafficking proteins are rich in modular domains that bind cell membranes. These binding events are tightly regulated in space and time. The structural, biochemical, and biophysical mechanisms for targeting have been worked out for many families of membrane binding domains. This review takes a comparative view of seven major classes of membrane binding domains, the C1, C2, PH, FYVE, PX, ENTH, and BAR domains. These domains use a combination of specific headgroup inter...

  5. Non-HDL-cholesterol as valid surrogate to apolipoprotein B100 measurement in diabetes: Discriminant Ratio and unbiased equivalence

    Directory of Open Access Journals (Sweden)

    Ahn Sylvie A

    2011-02-01

    Full Text Available Abstract Background Apolipoprotein B100 (apoB is a superior indicator of CV risk than total or LDL-C. Non-HDL-C represents a simple surrogate for apoB in hypertriglyceridemic and/or T2DM patients. ApoB and non-HDL-C show high correlation, although the degree of mutual concordance remains debated in CV risk evaluation. Objectives We used the Discriminant Ratio (DR methodology to compare the performance of non-HDL-C with that of apoB to rank diabetic patients according to dyslipidemia and to establish the underlying relationship between these variables taking measurement noise and intra-/intersubject variation into account, and to derive an unbiased equivalence equation. Methods Fasting total C, HDL-C, apoB and triglycerides were measured in 45 diabetic patients. The DR of the underlying between-subject standard deviation (SD to the within-subject SD was calculated from duplicates. Correlation coefficients between pairs were adjusted to include an estimate of the underlying correlation. Results Mean values [day 1 (1SD] were 143 (36 mg/dl (non-HDL-C and 98 (24 mg/dl (apoB. The DR's of both parameters were similar (1.76 and 1.83 (p = 0.83. Pearson's product-moment correlation coefficient between tests was very high (0.94, reaching unity (1.00 after attenuation adjustment. The unbiased equation of equivalence relating apoB to non-HDL-C had a slope of 0.65 and an intercept of 6.3 mg/dl. Conclusions The discrimination power of non-HDL-C is similar to that of apoB to rank diabetic patients according to atherogenic cholesterol and lipoprotein burden. Since true correlation between variables reached unity, non-HDL-C may provide not only a metabolic surrogate but also a candidate biometrical equivalent to apoB, as non-HDL-C calculation is readily available.

  6. Lifestyle and Dietary Determinants of Serum Apolipoprotein A1 and Apolipoprotein B Concentrations: Cross-Sectional Analyses within a Swedish Cohort of 24,984 Individuals

    Directory of Open Access Journals (Sweden)

    Kasper Frondelius

    2017-02-01

    Full Text Available Low serum apolipoprotein (Apo A1 concentrations and high serum ApoB concentrations may be better markers of the risk of cardiovascular disease than high-density lipoprotein (HDL and low-density lipoprotein (LDL. However, the associations between modifiable lifestyle factors and Apo concentrations have not been investigated in detail. Therefore, this study investigated the associations between Apo concentrations and education, lifestyle factors and dietary intake (macronutrients and 34 food groups. These cross-sectional associations were examined among 24,984 individuals in a Swedish population-based cohort. Baseline examinations of the cohort were conducted between 1991 and 1996. Dietary intake was assessed using a modified diet history method. The main determinants of high ApoA1 concentrations (r between 0.05 and 0.25 were high alcohol consumption, high physical activity, non-smoking, and a low body mass index (BMI, and the main determinants of high ApoB concentrations were smoking and a high BMI. The intake of sucrose and food products containing added sugar (such as pastries, sweets, chocolate, jam/sugar and sugar-sweetened beverages was negatively correlated with ApoA1 concentrations and positively correlated with ApoB concentrations and the ApoB/ApoA1 ratio, whereas the intake of fermented dairy products, such as fermented milk and cheese, was positively correlated with ApoA1 concentrations and negatively correlated with the ApoB/ApoA1 ratio. These results indicate that smoking, obesity, low physical activity, low alcohol consumption and a diet high in sugar and low in fermented dairy products are correlated with an unfavorable Apo profile.

  7. Apolipoprotein AIF gene variant S347 is associated with increased risk of coronary heart disease and lower apolipoprotein AIV plasma concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Wong, Wai-man R.; Hawe, Emma; Li, Lai K.; Miller, George J.; Nicaud, Viviane; Pennacchio, Len A.; Humphries, Steve E.; Talmud, Philippa J.

    2003-01-30

    The impact of common variants in the apolipoprotein gene cluster (APOC3-A4-A5) on prospective CHD risk was examined in healthy UK men. Of the 2808 men followed over nine years, 187 had a clinically defined CHD event. Examination of 9 single nucleotide polymorphisms (SNPs) in this group revealed that homozygotes for APOA4 S347 had significantly increased risk of CHD [Hazard ratio (HR) of 2.07 (95%CI 1.04-4.12)] while men homozygous for APOC3 1100T were protected (HR 0.28 (95%CI 0.09-0.87)). In stepwise multiple regression analysis, after entering all the variants and adjusting for established risk factors APOA4 T347S alone remained in the model. Using nine-SNP haplotype analysis, highest risk-estimate haplotypes carried APOA4 S347 and rare alleles of the two flanking intergenic markers. The protective effect of APOC31100T could be explained by negative linkage disequilibrium with these alleles. To determine the association of APOA4 T347S with apoAIVlevels, the relationship was examined in over 1600 healthy young European men and women. S347 homozygotes had significantly lower apoAIV plasma levels (13.48 + 0.6mg/dl) compared to carriers of the T347 allele (14.85 + 0.12 mg/dl) (p=0.025). These results demonstrate that genetic variation in and around APOA4, independent of effects of TG, is associated with risk of CHD and apoAIV levels, supporting an anti-atherogenic role for apoAIV.

  8. Domains via Graphs

    Institute of Scientific and Technical Information of China (English)

    ZHANG Guoqiang; CHEN Yixiang

    2001-01-01

    This paper provides a concrete and simple introduction to two pillars of domain theory: (1) solving recursive domain equations, and (2) universal and saturated domains. Our exposition combines Larsen and Winskel's idea on solving domain equations using information systems with Girard's idea of stable domain theory in the form of coherence spaces, or graphs.Detailed constructions are given for universal and even homogeneous objects in two categories of graphs: one representing binary complete, prime algebraic domains with complete primes covering the bottom; the other representing ω-algebraic, prime algebraic lattices. The backand-forth argument in model theory helps to enlighten the constructions.

  9. Robust phase-domain transmission line representation based on time-domain fitting

    Energy Technology Data Exchange (ETDEWEB)

    Nobre, Diana M.; Neves, Washington L.A. [Federal University of Campina Grande (UFCG), Electrical Engineering Department, Av Aprigio Veloso, 882 Campina Grande, PB 58.109-970 (Brazil); Boaventura, Wallace do C. [Federal University of Minas Gerais (UFMG), Electrical Engineering Department, Av Antonio Carlos, 6627 Pampulha, Belo Horizonte, MG 31.270-010 (Brazil)

    2006-05-15

    This work presents a methodology for deriving a phase-domain transmission line representation based on time-domain fitting. A polynomial matrix in the discrete-time domain describes the resulting model. The robustness of the representation, its stability and passivity, is attained by imbedding a set of constraints in the solution of the fitting equations, which are solved using quadratic programming. Results demonstrating from transient simulations the features of the derived representation are presented for the case of an asymmetric, untransposed two-phase transmission line. (author)

  10. Solid lipid nanoparticles as a vehicle for brain-targeted drug delivery: two new strategies of functionalization with apolipoprotein E

    Science.gov (United States)

    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.

  11. The apolipoprotein E epsilon4-allele and antihypertensive treatment are associated with increased risk of cerebral MRI white matter hyperintensities

    DEFF Research Database (Denmark)

    Høgh, P; Garde, Ellen; Mortensen, Erik Lykke;

    2007-01-01

    OBJECTIVE: Apolipoprotein E-epsilon4 (APOE-epsilon4) is a potential risk factor for cerebral vascular disease. The aim of the present study was to examine the relative importance of APOE-epsilon4 and other relevant risk factors for the extent of cerebral white matter hyperintensity (WMH...... the relative importance of the potential risk factors. RESULTS: APOE genotype and antihypertensive treatment were significantly associated with severity of total WMH load (P epsilon4 and WMH. Pharmaceutical treatment for arterial...

  12. Domains of laminin

    DEFF Research Database (Denmark)

    Engvall, E; Wewer, U M

    1996-01-01

    Extracellular matrix molecules are often very large and made up of several independent domains, frequently with autonomous activities. Laminin is no exception. A number of globular and rod-like domains can be identified in laminin and its isoforms by sequence analysis as well as by electron...... microscopy. Here we present the structure-function relations in laminins by examination of their individual domains. This approach to viewing laminin is based on recent results from several laboratories. First, some mutations in laminin genes that cause disease have affected single laminin domains, and some...... laminin isoforms lack particular domains. These mutants and isoforms are informative with regard to the activities of the mutated and missing domains. These mutants and isoforms are informative with regard to the activities of the mutated and missing domains. Second, laminin-like domains have now been...

  13. Apolipocrustacein, formerly vitellogenin, is the major egg yolk precursor protein in decapod crustaceans and is homologous to insect apolipophorin II/I and vertebrate apolipoprotein B

    Directory of Open Access Journals (Sweden)

    Lubzens Esther

    2007-01-01

    Full Text Available Abstract Background In animals, the biogenesis of some lipoprotein classes requires members of the ancient large lipid transfer protein (LLTP superfamily, including the cytosolic large subunit of microsomal triglyceride transfer protein (MTP, vertebrate apolipoprotein B (apoB, vitellogenin (Vtg, and insect apolipophorin II/I precursor (apoLp-II/I. In most oviparous species, Vtg, a large glycolipoprotein, is the main egg yolk precursor protein. Results This report clarifies the phylogenetic relationships of LLTP superfamily members and classifies them into three families and their related subfamilies. This means that the generic term Vtg is no longer a functional term, but is rather based on phylogenetic/structural criteria. In addition, we determined that the main egg yolk precursor protein of decapod crustaceans show an overall greater sequence similarity with apoLp-II/I than other LLTP, including Vtgs. This close association is supported by the phylogenetic analysis, i.e. neighbor-joining, maximum likelihood and Bayesian inference methods, of conserved sequence motifs and the presence of three common conserved domains: an N-terminal large lipid transfer module marker for LLTP, a DUF1081 domain of unknown function in their central region exclusively shared with apoLp-II/I and apoB, and a von Willebrand-factor type D domain at their C-terminal end. Additionally, they share a conserved functional subtilisin-like endoprotease cleavage site with apoLp-II/I, in a similar location. Conclusion The structural and phylogenetic data presented indicate that the major egg yolk precursor protein of decapod crustaceans is surprisingly closely related to insect apoLp-II/I and vertebrate apoB and should be known as apolipocrustacein (apoCr rather than Vtg. These LLTP may arise from an ancient duplication event leading to paralogs of Vtg sequences. The presence of LLTP homologs in one genome may facilitate redundancy, e.g. involvement in lipid metabolism and as

  14. Dihydrotestosterone regulating apolipoprotein M expression mediates via protein kinase C in HepG2 cells

    Directory of Open Access Journals (Sweden)

    Yi-zhou Ye

    2012-12-01

    Full Text Available Abstract Background Administration of androgens decreases plasma concentrations of high-density lipid cholesterol (HDL-C. However, the mechanisms by which androgens mediate lipid metabolism remain unknown. This present study used HepG2 cell cultures and ovariectomized C57BL/6 J mice to determine whether apolipoprotein M (ApoM, a constituent of HDL, was affected by dihydrotestosterone (DHT. Methods HepG2 cells were cultured in the presence of either DHT, agonist of protein kinase C (PKC, phorbol-12-myristate-13-acetate (PMA, blocker of androgen receptor flutamide together with different concentrations of DHT, or DHT together with staurosporine at different concentrations for 24 hrs. Ovariectomized C57BL/6 J mice were treated with DHT or vehicle for 7d or 14d and the levels of plasma ApoM and livers ApoM mRNA were measured. The mRNA levels of ApoM, ApoAI were determined by real-time RT-PCR. ApoM and ApoAI were determined by western blotting analysis. Results Addition of DHT to cell culture medium selectively down-regulated ApoM mRNA expression and ApoM secretion in a dose-dependent manner. At 10 nM DHT, the ApoM mRNA levels were about 20% lower than in untreated cells and about 40% lower at 1000 nM DHT than in the control cells. The secretion of ApoM into the medium was reduced to a similar extent. The inhibitory effect of DHT on ApoM secretion was not blocked by the classical androgen receptor blocker flutamide but by an antagonist of PKC, Staurosporine. Agonist of PKC, PMA, also reduced ApoM. At 0.5 μM PMA, the ApoM mRNA levels and the secretion of ApoM into the medium were about 30% lower than in the control cells. The mRNA expression levels and secretion of another HDL-associated apolipoprotein AI (ApoAI were not affected by DHT. The levels of plasma ApoM and liver ApoM mRNA of DHT-treated C57BL/6 J mice were lower than those of vehicle-treated mice. Conclusions DHT directly and selectively down-regulated the level of ApoM mRNA and the

  15. Apolipoprotein E4 reduces evoked hippocampal acetylcholine release in adult mice.

    Science.gov (United States)

    Dolejší, Eva; Liraz, Ori; Rudajev, Vladimír; Zimčík, Pavel; Doležal, Vladimír; Michaelson, Daniel M

    2016-02-01

    Apolipoprotein E4 (apoE4) is the most prevalent genetic risk factor for Alzheimer's disease. We utilized apoE4-targeted replacement mice (approved by the Tel Aviv University Animal Care Committee) to investigate whether cholinergic dysfunction, which increases during aging and is a hallmark of Alzheimer's disease, is accentuated by apoE4. This revealed that levels of the pre-synaptic cholinergic marker, vesicular acetylcholine transporter in the hippocampus and the corresponding electrically evoked release of acetylcholine, are similar in 4-month-old apoE4 and apolipoprotein E3 (apoE3) mice. Both parameters decrease with age. This decrease is, however, significantly more pronounced in the apoE4 mice. The levels of cholinacetyltransferase (ChAT), acetylcholinesterase (AChE), and butyrylcholinesterase (BuChE) were similar in the hippocampus of young apoE4 and apoE3 mice and decreased during aging. For ChAT, this decrease was similar in the apoE4 and apoE3 mice, whereas it was more pronounced in the apoE4 mice, regarding their corresponding AChE and BuChE levels. The level of muscarinic receptors was higher in the apoE4 than in the apoE3 mice at 4 months and increased to similar levels with age. However, the relative representation of the M1 receptor subtype decreased during aging in apoE4 mice. These results demonstrate impairment of the evoked release of acetylcholine in hippocampus by apoE4 in 12-month-old mice but not in 4-month-old mice. The levels of ChAT and the extent of the M2 receptor-mediated autoregulation of ACh release were similar in the adult mice, suggesting that the apoE4-related inhibition of hippocampal ACh release in these mice is not driven by these parameters. Evoked ACh release from hippocampal and cortical slices is similar in 4-month-old apoE4 and apoE3 mice but is specifically and significantly reduced in hippocampus, but not cortex, of 12-month-old apoE4 mice. This effect is accompanied by decreased VAChT levels. These findings show that

  16. ApolipoproteinE ε4 allelic variant, cognitive decline and psychosis in Alzheimer disease: a review of the literature and suggestions for upcoming studies

    Directory of Open Access Journals (Sweden)

    Ilaria Spoletini

    2006-06-01

    Full Text Available Apolipoprotein E (ApoE ε4 allele represents a well known vascular risk factor for developing Alzheimer disease (AD and differences in ApoE genotypes may explain a part of the variability in AD phenotypes. In fact, ApoE ε4 allele possession seems to be associated with a more precocious age of onset, greater episodic memory impairment, and psychotic symptoms. The first question we discuss regards the role of ApoE ε4 on cognitive progression of AD. In fact, while a general agreement exists about the role played by ApoE ε4 on the precocious onset of AD, cognitive decline has been differently associated with ApoE ε4 allele possession in AD patients in a continuum of faster decline, no effect, and slower decline. An attemptable interpretation is that the biological processes leading to the onset of AD are different from those involved in determining its clinical course. The second question regards the possible relationship between the presence of the degenerative pathological hallmarks of the disease in specific cerebral areas and different cognitive or behavioural symptoms. In fact, there is evidence that degenerative pathology in hippocampal formation and frontal cortex reflects the progression of cognitive deficits in brain aging and AD and that hypometabolism in right frontal lobe and greater frontal neuropsychological deficits occur in AD patients with psychosis in comparison to those without. The third question regards, specifically, the relationship between ApoE ε4 variant and behavioural symptoms. In fact, there is evidence supporting the link between being carriers of ApoE ε4 allele and severity of delusions, mostly at the early stage of the illness. In an interpretative challenge, we suggest that the link between being carriers of ApoE ε4 allele and suffering from delusions in AD may be explained by frontal lobe dysfunctions. Finally, we hypothesize that the most precocious onset of AD illness, described in carriers of ApoE ε4

  17. In silico analysis of the apolipoprotein E and the amyloid beta peptide interaction: misfolding induced by frustration of the salt bridge network.

    Directory of Open Access Journals (Sweden)

    Jinghui Luo

    2010-02-01

    Full Text Available The relationship between Apolipoprotein E (ApoE and the aggregation processes of the amyloid beta (A beta peptide has been shown to be crucial for Alzheimer's disease (AD. The presence of the ApoE4 isoform is considered to be a contributing risk factor for AD. However, the detailed molecular properties of ApoE4 interacting with the A beta peptide are unknown, although various mechanisms have been proposed to explain the physiological and pathological role of this relationship. Here, computer simulations have been used to investigate the process of A beta interaction with the N-terminal domain of the human ApoE isoforms (ApoE2, ApoE3 and ApoE4. Molecular docking combined with molecular dynamics simulations have been undertaken to determine the A beta peptide binding sites and the relative stability of binding to each of the ApoE isoforms. Our results show that from the several ApoE isoforms investigated, only ApoE4 presents a misfolded intermediate when bound to A beta. Moreover, the initial alpha-helix used as the A beta peptide model structure also becomes unstructured due to the interaction with ApoE4. These structural changes appear to be related to a rearrangement of the salt bridge network in ApoE4, for which we propose a model. It seems plausible that ApoE4 in its partially unfolded state is incapable of performing the clearance of A beta, thereby promoting amyloid forming processes. Hence, the proposed model can be used to identify potential drug binding sites in the ApoE4-A beta complex, where the interaction between the two molecules can be inhibited.

  18. Increased sensitivity of apolipoprotein E knockout mice to copper-induced oxidative injury to the liver.

    Science.gov (United States)

    Chen, Yuan; Li, Bin; Zhao, Ran-ran; Zhang, Hui-feng; Zhen, Chao; Guo, Li

    2015-04-10

    Apolipoprotein E (ApoE) genotypes are related to clinical presentations in patients with Wilson's disease, indicating that ApoE may play an important role in the disease. However, our understanding of the role of ApoE in Wilson's disease is limited. High copper concentration in Wilson's disease induces excessive generation of free oxygen radicals. Meanwhile, ApoE proteins possess antioxidant effects. We therefore determined whether copper-induced oxidative damage differ in the liver of wild-type and ApoE knockout (ApoE(-/-)) mice. Both wild-type and ApoE(-/-) mice were intragastrically administered with 0.2 mL of copper sulfate pentahydrate (200 mg/kg; a total dose of 4 mg/d) or the same volume of saline daily for 12 weeks, respectively. Copper and oxidative stress markers in the liver tissue and in the serum were assessed. Our results showed that, compared with the wild-type mice administered with copper, TBARS as a marker of lipid peroxidation, the expression of oxygenase-1 (HO-1), NAD(P)H dehydrogenase, and quinone 1 (NQO1) significantly increased in the ApoE(-/-) mice administered with copper, meanwhile superoxide dismutase (SOD) activity significantly decreased. Thus, it is concluded that ApoE may protect the liver from copper-induced oxidative damage in Wilson's disease.

  19. Endothelial cells downregulate apolipoprotein D expression in mural cells through paracrine secretion and Notch signaling.

    Science.gov (United States)

    Pajaniappan, Mohanasundari; Glober, Nancy K; Kennard, Simone; Liu, Hua; Zhao, Ning; Lilly, Brenda

    2011-09-01

    Endothelial and mural cell interactions are vitally important for proper formation and function of blood vessels. These two cell types communicate to regulate multiple aspects of vessel function. In studying genes regulated by this interaction, we identified apolipoprotein D (APOD) as one gene that is downregulated in mural cells by coculture with endothelial cells. APOD is a secreted glycoprotein that has been implicated in governing stress response, lipid metabolism, and aging. Moreover, APOD is known to regulate smooth muscle cells and is found in abundance within atherosclerotic lesions. Our data show that the regulation of APOD in mural cells is bimodal. Paracrine secretion by endothelial cells causes partial downregulation of APOD expression. Additionally, cell contact-dependent Notch signaling plays a role. NOTCH3 on mural cells promotes the downregulation of APOD, possibly through interaction with the JAGGED-1 ligand on endothelial cells. Our results show that NOTCH3 contributes to the downregulation of APOD and by itself is sufficient to attenuate APOD transcript expression. In examining the consequence of decreased APOD expression in mural cells, we show that APOD negatively regulates cell adhesion. APOD attenuates adhesion by reducing focal contacts; however, it has no effect on stress fiber formation. These data reveal a novel mechanism in which endothelial cells control neighboring mural cells through the downregulation of APOD, which, in turn, influences mural cell function by modulating adhesion.

  20. Overexpression of a Drosophila homolog of apolipoprotein D leads to increased stress resistance and extended lifespan.

    Science.gov (United States)

    Walker, David W; Muffat, Julien; Rundel, Colin; Benzer, Seymour

    2006-04-01

    Increased Apolipoprotein D (ApoD) expression has been reported in various neurological disorders, including Alzheimer's disease, schizophrenia, and stroke, and in the aging brain . However, whether ApoD is toxic or a defense is unknown. In a screen to identify genes that protect Drosophila against acute oxidative stress, we isolated a fly homolog of ApoD, Glial Lazarillo (GLaz). In independent transgenic lines, overexpression of GLaz resulted in increased resistance to hyperoxia (100% O(2)) as well as a 29% extension of lifespan under normoxia. These flies also displayed marked improvements in climbing and walking ability after sublethal exposure to hyperoxia. Overexpression of Glaz also increased resistance to starvation without altering lipid or protein content. To determine whether GLaz might be important in protection against reperfusion injury, we subjected the flies to hypoxia, followed by recovery under normoxia. Overexpression of GLaz was protective against behavioral deficits caused in normal flies by this ischemia/reperfusion paradigm. This and the accompanying paper by Sanchez et al. (in this issue of Current Biology) are the first to manipulate the levels of an ApoD homolog in a model organism. Our data suggest that human ApoD may play a protective role and thus may constitute a therapeutic target to counteract certain neurological diseases.

  1. Effects of Simvastatin on adiponectin and endothelial function in apolipoprotein E-deficient mice

    Institute of Scientific and Technical Information of China (English)

    Meng Liu; Donghua Yin; Ming Gui; Kejiang Cao

    2009-01-01

    0bjective:To investigate the effects of simvastatin,a 3-hydroxy-3-methylglutaryl coenzyme A(HMG-CoA) reductase inhibitor,on adiponectin and markers of endothelial function in apolipoprotein E-deficient mice at an early stage of atherosclerosis.Methods:Twenty-four 6-week old male apoE-deficient mice were randomly divided into two groups:control group(normal saline) and treatment group[simvastatin(5 mg/(kg·d)].Simvastatin was administered to treatment group mice by gavage and the same volume of normal saline was administered to control group mice by the same method for 4 weeks.Total cholesterol(TC),superoxide dismutase(SOD),malondialdehyde (MDA),and nitric oxide(NO) were measured by biochemical analysis,and adiponectin was measured by an ABC-ELISA method.Results:There was no significant difference in serum TC between control and treatment groups.Compared with the control animals,simvastafin-treated animals exhibited a significant increase in serurn levels of adponectin,SOD and NO,and decrease in serum MDA(P <0.01).Conclusion:Simvastatin protects endothelial function by increasing serum adiponectin,which may increase serum SOD and NO,and decrease serum MDA.This study suggests that sirnvastatin has therapeutic advantages,unrelated to its cholesterol-lowering effect,that are mediated by adiponectin.

  2. Nanoparticle charge-transfer interactions induce surface dependent conformational changes in apolipoprotein biocorona

    CERN Document Server

    Raghavendra, Achyut J; Brown, Jared M; Podilaa, Ramakrishna

    2016-01-01

    Upon introduction into a biological system, engineered nanomaterials (ENMs) rapidly associate with a variety of biomolecules such as proteins and lipids to form a biocorona. The presence of biocorona influences nano-bio interactions considerably, and could ultimately result in altered biological responses. Apolipoprotein A-I (ApoA-I), the major constituent of high-density lipoprotein (HDL), is one of the most prevalent proteins found in ENM-biocorona irrespective of ENM nature, size, and shape. Given the importance of ApoA-I in HDL and cholesterol transport, it is necessary to understand the mechanisms of ApoA-I adsorption and the associated structural changes for assessing consequences of ENM exposure. Here, we used a comprehensive array of microscopic and spectroscopic tools to elucidate the interactions between ApoA-I and 100 nm Ag nanoparticles (AgNPs) with four different surface functional groups. We found that the protein adsorption and secondary structural changes are highly dependent on the surface fu...

  3. Meta-analysis of peripheral blood apolipoprotein E levels in Alzheimer's disease.

    Directory of Open Access Journals (Sweden)

    Chong Wang

    Full Text Available BACKGROUND: Peripheral blood Apolipoprotein E (ApoE levels have been proposed as biomarkers of Alzheimer's disease (AD, but previous studies on levels of ApoE in blood remain inconsistent. This meta-analysis was designed to re-examine the potential role of peripheral ApoE in AD diagnosis and its potential value as a candidate biomarker. METHODS: We conducted a systematic literature search of MEDLINE, EMBASE, the Cochrane library, and BIOSIS previews for case-control studies measuring ApoE levels in serum or plasma from AD subjects and healthy controls. The pooled weighted mean difference (WMD and 95% confidence interval (CI were used to estimate the association between ApoE levels and AD risk. RESULTS: Eight studies with a total of 2250 controls and 1498 AD cases were identified and analyzed. The pooled WMD from a random-effect model of AD participants compared with the healthy controls was -5.59 mg/l (95% CI: [-8.12, -3.06]. The overall pattern in WMD was not varied by characteristics of study, including age, country, assay method, publication year, and sample type. CONCLUSIONS: Our meta-analysis supports a lowered level of blood ApoE in AD patients, and indicates its potential value as an important risk factor for AD. Further investigation employing standardized assay for ApoE measurement are still warranted to uncover the precise role of ApoE in the pathophysiology of AD.

  4. Extracellular proteolysis of apolipoprotein E (apoE by secreted serine neuronal protease.

    Directory of Open Access Journals (Sweden)

    Irfan Y Tamboli

    Full Text Available Under normal conditions, brain apolipoprotein E (apoE is secreted and lipidated by astrocytes, then taken up by neurons via receptor mediated endocytosis. Free apoE is either degraded in intraneuronal lysosomal compartments or released. Here we identified a novel way by which apoE undergoes proteolysis in the extracellular space via a secreted neuronal protease. We show that apoE is cleaved in neuronal conditioned media by a secreted serine protease. This apoE cleavage was inhibited by PMSF and α1-antichymotrypsin, but not neuroserpin-1 or inhibitors of thrombin and cathepsin G, supporting its identity as a chymotrypsin like protease. In addition, apoE incubation with purified chymotrypsin produced a similar pattern of apoE fragments. Analysis of apoE fragments by mass spectrometry showed cleavages occurring at the C-terminal side of apoE tryptophan residues, further supporting our identification of cleavage by chymotrypsin like protease. Hippocampal neurons were more efficient in mediating this apoE cleavage than cortical neurons. Proteolysis of apoE4 generated higher levels of low molecular weight fragments compared to apoE3. Primary glial cultures released an inhibitor of this proteolytic activity. Together, these studies reveal novel mechanism by which apoE can be regulated and therefore could be useful in designing apoE directed AD therapeutic approaches.

  5. Apolipoprotein E isotype-dependent modulation of microRNA-146a in plasma and brain.

    Science.gov (United States)

    Teter, Bruce; LaDu, Mary Jo; Sullivan, Patrick M; Frautschy, Sally A; Cole, Greg M

    2016-08-01

    The Apolipoprotein E (ApoE) isotype ApoE4 is a prevalent genetic risk factor for Alzheimer's disease (AD) that can modulate systemic and central inflammation, independent of amyloid accumulation. Although disruption of innate immune toll receptor signaling is modulated by ApoE and observed in AD, ApoE isotype-specific effects remain poorly understood. Therefore, we examined the effect of the ApoE isotype on the brain levels of major regulators of TLR signaling including miR146a, a microRNA enriched in the brain. We used 6-month-old ApoE3 or ApoE4 targeted replacement mice with and without mutant familial AD transgenes. ApoE4 reduced the levels of miR146a compared with ApoE3, both in the brain (29%; PmiR146) that correlated inversely with miR146a levels (r=0.637; P<0.0001). Reduced negative feedback of toll-like receptor signaling (by miRNA146a) can explain early-life hypersensitivity to innate immune stimuli (including Aβ) in ApoE4 carriers. Thus, ApoE4 causes early dysregulation of a central controller of the innate immune system both centrally and systemically. This defect persists with familial AD pathology and may be relevant to ApoE4 AD risk.

  6. Association of apolipoprotein E polymorphism with plasma lipids and Alzheimer's disease in a Southern Brazilian population

    Directory of Open Access Journals (Sweden)

    de-Andrade F.M.

    2000-01-01

    Full Text Available Apolipoprotein E (protein: apo E; gene: APOE plays an important role in the multifactorial etiology of both Alzheimer's disease (AD and lipid level concentrations. The polymerase chain reaction (PCR was used to investigate the APOE gene polymorphism in 446 unrelated Caucasians, among them 23 AD patients, and 100 Afro-Brazilians living in Porto Alegre, Brazil. The frequencies of the APOE*2, APOE*3 and APOE*4 alleles were 0.075, 0.810 and 0.115 in Caucasians and 0.075, 0.700 and 0.225 in Afro-Brazilians, respectively (c2 = 8.72, P = 0.013. A highly significant association was observed between the APOE*4 allele and AD in this population-based sample. The APOE*4 frequency in AD patients (39% was about four times higher than in the general Caucasian population (11.5%. The influence of each of the three common APOE alleles on lipid traits was evaluated by the use of the average excess statistic. The E*2 allele is associated with lower levels of triglycerides and of total and non-HDL cholesterol in both men and women. Conversely, the E*4 allele is associated with higher levels of these traits in women only. The effect of APOE alleles was of greater magnitude in women.

  7. Apolipoprotein e genotype, plasma cholesterol, and cancer: a Mendelian randomization study.

    LENUS (Irish Health Repository)

    Trompet, Stella

    2009-12-01

    Observational studies have shown an association between low plasma cholesterol levels and increased risk of cancer, whereas most randomized clinical trials involving cholesterol-lowering medications have not shown this association. Between 1997 and 2002, the authors assessed the association between plasma cholesterol levels and cancer risk, free from confounding and reverse causality, in a Mendelian randomization study using apolipoprotein E (ApoE) genotype. ApoE genotype, plasma cholesterol levels, and cancer incidence and mortality were measured during a 3-year follow-up period among 2,913 participants in the Prospective Study of Pravastatin in the Elderly at Risk. Subjects within the lowest third of plasma cholesterol level at baseline had increased risks of cancer incidence (hazard ratio (HR) = 1.90, 95% confidence interval (CI): 1.34, 2.70) and cancer mortality (HR = 2.03, 95% CI: 1.23, 3.34) relative to subjects within the highest third of plasma cholesterol. However, carriers of the ApoE2 genotype (n = 332), who had 9% lower plasma cholesterol levels than carriers of the ApoE4 genotype (n = 635), did not have increased risk of cancer incidence (HR = 0.86, 95% CI: 0.50, 1.47) or cancer mortality (HR = 0.70, 95% CI: 0.30, 1.60) compared with ApoE4 carriers. These findings suggest that low cholesterol levels are not causally related to increased cancer risk.

  8. Characterization and measurement of human apolipoprotein A-II by radioimmunoassay.

    Science.gov (United States)

    Goldberg, R B; Karlin, J B; Juhn, D J; Scanu, A M; Edelstein, C; Rubenstein, A H

    1980-09-01

    The development of a radioimmunoassay for apolipoprotein A-II (apo A-II) is described. Initial studies revealed a lack of immunological identity between purified apo A-II used as the standard and serum or HDL. Extensive testing of different buffers, standards, antisera, tracers, utilization of a detergent, and heating of sera failed to resolve the problem. Gel filtration of iodinated and non-iodinated apo A-II on Sephadex G-100 columns showed that apo A-II, in dilute solution, elutes in a higher molecular zone than expected with a broad, assymetrical profile. The use of a subfraction of the tracer in the assay resulted in parallelism in the serum and standard dilution curves. The apo A-II assay was sensitive, specific, and reproducible. Apo A-II added to sera was fully recovered and delipidation did not affect the immunoreactivity of either serum or HDL. Apo A-II contributed approximately 20% to the protein mass of HDL. Comparison of these results with those obtained by radial immunodiffusion, and with previously reported data, indicates that the reactivity of apo A-II in its native and delipidated forms may be markedly influenced by different immunologic methodologies and their specific reagents. Caution should thus be shown at present in assigning absolute concentrations to apo A-II in serum or HDL.

  9. Endothelium-protective sphingosine-1-phosphate provided by HDL-associated apolipoprotein M

    DEFF Research Database (Denmark)

    Christoffersen, Christina; Obinata, Hideru; Kumaraswamy, Sunil B

    2011-01-01

    Protection of the endothelium is provided by circulating sphingosine-1-phosphate (S1P), which maintains vascular integrity. We show that HDL-associated S1P is bound specifically to both human and murine apolipoprotein M (apoM). Thus, isolated human ApoM(+) HDL contained S1P, whereas ApoM(-) HDL did...... not. Moreover, HDL in Apom(-/-) mice contains no S1P, whereas HDL in transgenic mice overexpressing human apoM has an increased S1P content. The 1.7-Å structure of the S1P-human apoM complex reveals that S1P interacts specifically with an amphiphilic pocket in the lipocalin fold of apoM. Human ApoM......(+) HDL induced S1P(1) receptor internalization, downstream MAPK and Akt activation, endothelial cell migration, and formation of endothelial adherens junctions, whereas apoM(-) HDL did not. Importantly, lack of S1P in the HDL fraction of Apom(-/-) mice decreased basal endothelial barrier function in lung...

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

    Energy Technology Data Exchange (ETDEWEB)

    Reyland, M.E.; Forgez, P.; Prack, M.M.; Williams, D.L. (State Univ. of New York, Stony Brook (United States)); Gwynne, J.T. (Univ. of North Carolina, Chapel Hill (United States))

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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. Substituted Benzamides Containing Azaspiro Rings as Upregulators of Apolipoprotein A-I Transcription

    Directory of Open Access Journals (Sweden)

    Bin Hong

    2012-06-01

    Full Text Available Apolipoprotein A-I (Apo A-I is the principal protein component of high density lipoprotein (HDL, which is generally considered as a potential therapeutic target against atherosclerosis. The understanding of the Apo A-I regulation mechanism has fuelled the development of novel HDL targeted therapeutic approaches. To identify novel agents that can upregulate Apo A-I expression, we performed a cell-based reporter assay to screen 25,600 small molecules. Based on the dataset obtained from screening, a series of novel analogs of substituted benzamides containing azaspiro rings were assessed for their ability to induce the transcription of the Apo A-I gene, and the structure-activity relationship (SAR around these analogs was also proposed. The results indicated that the trifluoromethyl substituted benzamide containing an azaspiro ring is a promising backbone for designing Apo A-I transcriptional upregulator and could be viable leads for development of new drugs to prevent and treat atherosclerosis in the future.

  13. Homologue of mammalian apolipoprotein A-Ⅱ in non-mammalian vertebrates

    Institute of Scientific and Technical Information of China (English)

    Malay Choudhury; Shoji Yamada; Masaharu Komatsu; Hideki Kishimura; Seiichi Ando

    2009-01-01

    Although apolipoprotein with molecular weight 14 kDa (apo-14 kDa) is associated with fish plasma highdensity lipoproteins(HDLs),it remains to be determined whether apo-14 kDa is the homologue of mammalian apoA-Ⅱ.We have obtained the full cDNA sequences that encode Japanese eel and rainbow trout apo-14 kDa.Homologues of Japanese eel apo-14 kDa sequence could be found in 14 fish species deposited in the DDBJ/EMBL/GenBank or TGI database.Fish apo14 kDa lacks propeptide and contains more internal repeats than mammalian apoA-Ⅱ.Nevertheless,phylogenetic analysis allowed fish apo-14 kDa to be the homologue of mammalian apoA-Ⅱ.In addition,in silico cloning of the TGI,Ensembl,or NCBI database revealed apoA-Ⅱs in dog,chicken,green anole lizard,and African clawed frog whose sequences had not so far been available,suggesting both apoA-Ⅰ and apoA-Ⅱas fundamental constituents of vertebrate HDLs.

  14. Taurine reduces the secretion of apolipoprotein B100 and lipids in HepG2 cells

    Directory of Open Access Journals (Sweden)

    Nagao Koji

    2008-10-01

    Full Text Available Abstract Background Higher concentrations of serum lipids and apolipoprotein B100 (apoB are major individual risk factors of atherosclerosis and coronary heart disease. Therefore ameliorative effects of food components against the diseases are being paid attention in the affluent countries. The present study was undertaken to investigate the effect of taurine on apoB secretion and lipid metabolism in human liver model HepG2 cells. Results The results demonstrated that an addition of taurine to the culture media reduces triacylglycerol (TG-mass in the cells and the medium. Similarly, cellular cholesterol-mass was decreased. Taurine inhibited the incorporation of [14C] oleate into cellular and medium TG, suggesting the inhibition of TG synthesis. In addition, taurine reduced the synthesis of cellular cholesterol ester and its secretion, suggesting the inhibition of acyl-coenzyme A:cholesterol acyltransferase activity. Furthermore, taurine reduced the secretion of apoB, which is a major protein component of very low-density lipoprotein. Conclusion This is a first report to demonstrate that taurine inhibits the secretion of apoB from HepG2 cells.

  15. Dementia and Diabetes Mellitus: Association with Apolipoprotein E4 Polymorphism from a Hospital in Southern India

    Directory of Open Access Journals (Sweden)

    Lakshmi Narayanan Kota

    2012-01-01

    Full Text Available Objective. To evaluate the association of Apolipoprotein E4 (ApoE4 in Alzheimer's dementia (AD with comorbid diabetes mellitus (DM. Methods. The study included subjects with Alzheimer's dementia (AD (n=209, individuals with non-Alzheimer's dementia (nAD (n=122, individuals with parental history of AD (f/hAD (n=70, and control individuals who had normal cognitive functions and no parental history of dementia (NC (n=193. Dementia was diagnosed using International Classification of Diseases-10 revision (ICD-10 criteria. DM was assessed on the basis of self-report and/or use of antidiabetic medications. ApoE genotyping was done using sequence-specific primer polymerase chain reaction. Results. ApoE4 allele frequencies were highest among AD with comorbid DM (0.35 followed by AD without DM (0.25, nAD with DM (0.13, nAD without comorbid DM (0.12, and NC (0.08. Frequency of ApoE4 in persons with f/hAD was 0.13. The association of AD with co-morbid DM in ApoE4 carriers was more in comparison to NC with DM (OR=5.68, P=0.04. Conclusion. There is a significant association between AD with co-morbid DM and ApoE4 genotype.

  16. Is apolipoprotein E4 an important risk factor for vascular dementia?

    Science.gov (United States)

    Rohn, Troy T

    2014-01-01

    Despite the fact that vascular dementia (VaD) represents the seconding leading cause of dementia in the USA, behind only Alzheimer's disease (AD), there remains a lack of consensus on the pathological criteria required for diagnosis of this disease. A number of clinical diagnostic criteria exist but are poorly validated and inconsistently applied. It is clear that vascular risk factors play an important role in the etiology of VaD, including hypertension, stroke, diabetes, and atherosclerosis. Vascular risk factors may increase the risk for VaD by promoting inflammation, cerebral vascular disease, white matter lesions, and hippocampal sclerosis. Because vascular risk factors seem to impart a high degree of risk for conferring VaD, it seems logical that the apolipoprotein E (APOE) status of individuals may be important. APOE plays a critical role in transporting cholesterol in and out of the CNS and in AD it is known that harboring the APOE allele increases the risk of AD perhaps due to the improper functioning of this protein. The purpose of this review is to examine the important pathological features and risk factors for VaD and to provide a critical assessment of the current literature regarding whether or not apoE4 also confers disease risk in VaD. The preponderance of data suggests that harboring one or both APOE4 alleles elevates the risk for VaD, but not to the same extent as found in AD.

  17. An ultrasensitive electrochemical immunosensor for apolipoprotein E4 based on fractal nanostructures and enzyme amplification.

    Science.gov (United States)

    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.

  18. Apolipoprotein E4 produced in GABAergic interneurons causes learning and memory deficits in mice.

    Science.gov (United States)

    Knoferle, Johanna; Yoon, Seo Yeon; Walker, David; Leung, Laura; Gillespie, Anna K; Tong, Leslie M; Bien-Ly, Nga; Huang, Yadong

    2014-10-15

    Apolipoprotein (apo) E4 is expressed in many types of brain cells, is associated with age-dependent decline of learning and memory in humans, and is the major genetic risk factor for AD. To determine whether the detrimental effects of apoE4 depend on its cellular sources, we generated human apoE knock-in mouse models in which the human APOE gene is conditionally deleted in astrocytes, neurons, or GABAergic interneurons. Here we report that deletion of apoE4 in astrocytes does not protect aged mice from apoE4-induced GABAergic interneuron loss and learning and memory deficits. In contrast, deletion of apoE4 in neurons does protect aged mice from both deficits. Furthermore, deletion of apoE4 in GABAergic interneurons is sufficient to gain similar protection. This study demonstrates a detrimental effect of endogenously produced apoE4 on GABAergic interneurons that leads to learning and memory deficits in mice and provides a novel target for drug development for AD related to apoE4.

  19. Computational design of apolipoprotein E4 inhibitors for Alzheimer's disease therapy from traditional Chinese medicine.

    Science.gov (United States)

    Huang, Hung-Jin; Chen, Hsin-Yi; Lee, Cheng-Chun; Chen, Calvin Yu-Chian

    2014-01-01

    Apolipoprotein E4 (Apo E4) is the major genetic risk factor in the causation of Alzheimer's disease (AD). In this study we utilize virtual screening of the world's largest traditional Chinese medicine (TCM) database and investigate potential compounds for the inhibition of ApoE4. We present the top three TCM candidates: Solapalmitine, Isodesacetyluvaricin, and Budmunchiamine L5 for further investigation. Dynamics analysis and molecular dynamics (MD) simulation were used to simulate protein-ligand complexes for observing the interactions and protein variations. Budmunchiamine L5 did not have the highest score from virtual screening; however, the dynamics pose is similar to the initial docking pose after MD simulation. Trajectory analysis reveals that Budmunchiamine L5 was stable over all simulation times. The migration distance of Budmunchiamine L5 illustrates that docked ligands are not variable from the initial docked site. Interestingly, Arg158 was observed to form H-bonds with Budmunchiamine L5 in the docking pose and MD snapshot, which indicates that the TCM compounds could stably bind to ApoE4. Our results show that Budmunchiamine L5 has good absorption, blood brain barrier (BBB) penetration, and less toxicity according to absorption, distribution, metabolism, excretion, and toxicity (ADMET) prediction and could, therefore, be safely used for developing novel ApoE4 inhibitors.

  20. Apolipoprotein E4 genotype does not increase risk of HIV-associated neurocognitive disorders.

    Science.gov (United States)

    Morgan, E E; Woods, S P; Letendre, S L; Franklin, D R; Bloss, C; Goate, A; Heaton, R K; Collier, A C; Marra, C M; Gelman, B B; McArthur, J C; Morgello, S; Simpson, D M; McCutchan, J A; Ellis, R J; Abramson, I; Gamst, A; Fennema-Notestine, C; Smith, D M; Grant, I; Vaida, F; Clifford, D B

    2013-04-01

    This is a cross-sectional, observational study to evaluate the hypothesis that HIV-seropositive (HIV+) apolipoprotein E4 (APOE4) carriers are at increased risk for HIV-associated neurocognitive disorders (HAND) compared to APOE4 noncarriers with HIV in the CNS HIV Antiretroviral Therapy Effects Research (CHARTER) Group sample. APOE genotype was determined in 466 CHARTER participants with varying disease stages and histories of antiretroviral treatment who did not have severe psychiatric or medical comorbid conditions that preclude diagnosis of HAND. HAND diagnoses were based on results of comprehensive neurobehavioral evaluation and use of current neuroAIDS diagnostic criteria. HAND status consists of two levels: neuropsychologically normal status (i.e., no HAND) and any HAND diagnosis (i.e., asymptomatic neurocognitive impairment, minor neurocognitive disorder, HIV-associated dementia). Logistic regression analyses revealed no association between APOE4 carrier status and HAND, and there were no interactions between APOE4 carrier status and ethnicity, age, substance use disorders, duration of infection, or nadir CD4. Results did not differ when analysis was restricted to symptomatic HAND, and no APOE4 gene dose-dependent relationship to HAND emerged. APOE4 status was not associated with concurrent HAND in this large, well-characterized sample. This does not preclude emergence of an association between APOE4 status and HAND as this population ages. Prospective, longitudinal studies are needed to examine APOE4 as a risk factor for neurocognitive decline, incident HAND at older ages, and potential associations with cerebrospinal fluid amyloid.

  1. Cognitive functions, lipid profile, and Apolipoprotein E gene polymorphism in postmenopausal women

    Directory of Open Access Journals (Sweden)

    Iwona Bojar

    2015-05-01

    Full Text Available The objective of the study was investigation of the relationship between cognitive functions and lipid profile, BMI and change of body weight in postmenopausal women carriers of Apolipoprotein E gene polymorphisms (APOE. A group of 170 women was recruited to the study. The inclusion criteria were: minimum of two years after the last menstruation, FSH concentration 30 U/ml and no signs of dementia on the Montreal Cognitive Assessment (MoCA. A computerized battery of Central Nervous System Vital Signs (CNS VS was used for diagnostic cognitive functions. APOE genotype was performed by multiplex PCR. In blood plasma were determined: triglycerides, total cholesterol and its fractions: HDL cholesterol and LDL cholesterol. Statistical analysis was performed using two-way analysis of variance in STATISTICA software. In the postmenopausal women examined, the carrier state of APOE gene polymorphism was associated with the level of triglycerides, and results concerning three cognitive functions: executive functions, psychomotor speed, and cognitive flexibility. Loss of body weight in postmenopausal women was related with lower results in neurocognitive index and the majority of cognitive functions. The results concerning cognitive functions in postmenopausal women in the study were not significantly related with lipid profile. Significant differences were observed according to APOE gene polymorphism in correlations between LDL/HDL and CHOL/HDL ratios, and results in the processing speed and reaction time, as well as between the BMI and results in processing speed in the postmenopausal women examined.

  2. A Study on Apolipoprotein E Polymorphism in Early Onset of Coronary Heart Disease

    Institute of Scientific and Technical Information of China (English)

    朱铁兵; 杨志健; 钱卫冲; 王连生; 马根山; 马文珠

    2003-01-01

    Objective:To assess the relationship between apolipoprotein E( apoE) polymorphism and early anset of Coronary heart disease(CHD) and the effect of apoE on lipids and lipoproteins in Chinese healthy subjects.Methods:Sixty-eight cases(CHD1) aged less than 55y,136 cases(CHD2) aged more than 65y with CHD and 136 healthy subjects were enrolled and their plamsma levels of triglyceride(TG),total cholesterol(TC) and high density lipoprotein cholesterol(HDL-C) were determined.The apoE genotypes were identified by polymerase chain reaction-restriction fragment lengths polymorphism.Results:apoE3/4 genotype and E4 allele frequency in CHD1 were higher than those in CHD2 and healthy subjects and no difference was found between CHD2 and healthy subjects.Meanwhile the plasma levels of TC and low density lipoprotein cholesterol(LDL-C) were higher in CHD2 than in either CHD1 or healthy subjects.Each apoE isoprotein has variable TC and LDL-C levels characterized by E2(E2/2+E2/3)

  3. Phosphorylation-dependent down-regulation of apolipoprotein A5 by insulin

    Energy Technology Data Exchange (ETDEWEB)

    Nowak, Maxine; Helleboid-Chapman, Audrey; Jakel, Heidelinde; Rommens, Corinne; Martin, Genevieve; Duran-Sandoval, Daniel; Staels, Bart; Rubin, Edward M.; Pennacchio, Len A.; Taskinen, Marja-Riitta; Fruchart-Najib, Jamila; Fruchart, Jean-Charles

    2004-02-15

    The apolipoprotein A5 (APOA5) gene has been shown to be important in lowering plasma triglyceride levels. Since several studies have shown that hyperinsulinemia is associated with hypertriglyceridemia, we sought to determine whether APOA5 gene is regulated by insulin. We show here that cell and mouse treatments with insulin down-regulated APOA5 expression in a dose-dependent manner. Furthermore, we determined that insulin decreases APOA5 promoter activity and subsequent deletion analyses revealed an E-box-containing fragment. We showed that Upstream Stimulatory Factors, USF1/USF2, bind to the identified E-box in the APOA5 promoter. Moreover, in cotransfection studies, USF1 stimulates APOA5 promoter activity. The treatment with insulin reduces the binding of USF1/USF2 to APOA5 promoter. The inhibition of PI3K pathway with wortmannin abolished the insulin s effect on APOA5 gene transcription. Using oligoprecipitation method of USF from nuclear extracts, we demonstrated that phosphorylated USF1 failed to bind to APOA5 promoter. This indicates that the APOA5 gene transrepression by insulin involves a phosphorylation of USF through PI3K, that modulate their binding to APOA5 promoter and results in APOA5 down-regulation. The effect of exogenous hyperinsulinemia in healthy men shows a decrease of the plasma ApoAV level. These data suggest a potential mechanism involving APOA5 gene in hypertriglyceridemia associated with hyperinsulinemia.

  4. Structural and Functional Analysis of the ApolipoproteinA-I A164S Variant.

    Directory of Open Access Journals (Sweden)

    Jonathan Dalla-Riva

    Full Text Available 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.

  5. Regulation of the Apolipoprotein Gene Cluster by a Long Noncoding RNA

    Directory of Open Access Journals (Sweden)

    Paul Halley

    2014-01-01

    Full Text Available Apolipoprotein A1 (APOA1 is the major protein component of high-density lipoprotein (HDL in plasma. We have identified an endogenously expressed long noncoding natural antisense transcript, APOA1-AS, which acts as a negative transcriptional regulator of APOA1 both in vitro and in vivo. Inhibition of APOA1-AS in cultured cells resulted in the increased expression of APOA1 and two neighboring genes in the APO cluster. Chromatin immunoprecipitation (ChIP analyses of a ∼50 kb chromatin region flanking the APOA1 gene demonstrated that APOA1-AS can modulate distinct histone methylation patterns that mark active and/or inactive gene expression through the recruitment of histone-modifying enzymes. Targeting APOA1-AS with short antisense oligonucleotides also enhanced APOA1 expression in both human and monkey liver cells and induced an increase in hepatic RNA and protein expression in African green monkeys. Furthermore, the results presented here highlight the significant local modulatory effects of long noncoding antisense RNAs and demonstrate the therapeutic potential of manipulating the expression of these transcripts both in vitro and in vivo.

  6. Longitudinal Trajectories of Cholesterol from Midlife through Late Life according to Apolipoprotein E Allele Status

    Directory of Open Access Journals (Sweden)

    Brian Downer

    2014-10-01

    Full Text Available Background: Previous research indicates that total cholesterol levels increase with age during young adulthood and middle age and decline with age later in life. This is attributed to changes in diet, body composition, medication use, physical activity, and hormone levels. In the current study we utilized data from the Framingham Heart Study Original Cohort to determine if variations in apolipoprotein E (APOE, a gene involved in regulating cholesterol homeostasis, influence trajectories of total cholesterol, HDL cholesterol, and total: HDL cholesterol ratio from midlife through late life. Methods: Cholesterol trajectories from midlife through late life were modeled using generalized additive mixed models and mixed-effects regression models. Results: APOE e2+ subjects had lower total cholesterol levels, higher HDL cholesterol levels, and lower total: HDL cholesterol ratios from midlife to late life compared to APOE e3 and APOE e4+ subjects. Statistically significant differences in life span cholesterol trajectories according to gender and use of cholesterol-lowering medications were also detected. Conclusion: The findings from this research provide evidence that variations in APOE modify trajectories of serum cholesterol from midlife to late life. In order to efficiently modify cholesterol through the life span, it is important to take into account APOE allele status.

  7. Screening for the familial defective apolipoprotein B-100 R3500W by mutagenic primers PCR

    Institute of Scientific and Technical Information of China (English)

    冯纪安; 冯铮

    2002-01-01

    Objective A method combining the mutagenic primers PCR and restriction enzyme digestion was designed to facilitate the detection of gene mutation in familial defective apolipoprotein B-1O0 R3500W. Methods A pair of primer was designed and a mismatch nucleotide was introduced in its upstream primer. A segment of target DNA including the possibly mutated nucleotide was amplified by PCR and the products were digested by restriction enzyme Nco 1. To overcome the potential false negative results due to improper digestion conditions, a segment of DNA with Ncol cut size was added as reference.Results The target sequence was successfully amplified by PCR, producing a 144 bp DNA fragment as expected. When incubated with Ncol, the enzyme could digest the DNA, producing a 114 bp segment,only if it was amplified from the mutated gene, but not from the normal allele. This difference in length of DNA could be separated by electrophoresis on a 2 %agarose gel. Thus we successfully detected two carriers of heterozygous FDB R3500W in 162 hypercholesterolemic patients. Conclusions Mutagenic primers PCR can be used to detect the gene mutation of apo B-100 R3500W, two cases were detected among 162patients with hypercholesterolemia. It suggests that this mutation is not rare in mainland China.

  8. Multiple members of the plasminogen-apolipoprotein(a) gene family associated with thrombosis

    Energy Technology Data Exchange (ETDEWEB)

    Ichinose, Akitada (Univ. of Washington, Seattle (United States))

    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.

  9. Relationship Between Plasma Insulin Level and Apolipoprotein E Gene Polymorphysm in Alzheimer′s Disease

    Institute of Scientific and Technical Information of China (English)

    Luo Zhuming; Yuan Qiang

    2000-01-01

    Objective: To study relationship between plasma insulin level and apolipoprotein E Gene polymorphysm in Alzheimcr′s Disease. Background: Recent researches have shown that there was a close relationship between ApoE- ε 4 allele and AD. Because of the discovery of hyperinsulineamia in AD patients, the study of insulin on the pathogenesis of AD become a hot point of AD reseearch. Methods: We apply PCR-RFLP to the ApoE genotype study of 45 AD paticnts and 32 normal controls. At the same time, plasma insulin and glucose level was measured in the abovc objects. Results and Discussion: The frequency of ApoE- ε 4 in AD (32.2%) is much higher than in controls (10.9%). On the contrary, the frequency of ApeE- ε 4 is relatively lower in AD than in thc controls. The resistence of hyperinsulineamia in AD. Insulin sensitivity decreased in AD. Conclusion: When gene dose of ApoE- ε 4 increases, the prcvalance of AD increase, while the on-set ages of AD decrease (P<0.05). These findings indicatc that AD patients may have insulin resistance anbd insulin probably play a role in AD pathogenesis. In addition, the s 4 homozygote AD patients seem to have loweer plasma insulin level that the non- ε 4 homozygote AD patients (P<0.05). But this situation need to be replicated in studies of larger sample.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  11. Evolutionary analysis of apolipoprotein E by Maximum Likelihood and complex network methods

    Directory of Open Access Journals (Sweden)

    Leandro de Jesus Benevides

    Full Text Available Abstract Apolipoprotein E (apo E is a human glycoprotein with 299 amino acids, and it is a major component of very low density lipoproteins (VLDL and a group of high-density lipoproteins (HDL. Phylogenetic studies are important to clarify how various apo E proteins are related in groups of organisms and whether they evolved from a common ancestor. Here, we aimed at performing a phylogenetic study on apo E carrying organisms. We employed a classical and robust method, such as Maximum Likelihood (ML, and compared the results using a more recent approach based on complex networks. Thirty-two apo E amino acid sequences were downloaded from NCBI. A clear separation could be observed among three major groups: mammals, fish and amphibians. The results obtained from ML method, as well as from the constructed networks showed two different groups: one with mammals only (C1 and another with fish (C2, and a single node with the single sequence available for an amphibian. The accordance in results from the different methods shows that the complex networks approach is effective in phylogenetic studies. Furthermore, our results revealed the conservation of apo E among animal groups.

  12. Hypercholesterolemia promotes early renal dysfunction in apolipoprotein E-deficient mice

    Directory of Open Access Journals (Sweden)

    Balarini Camille M

    2011-11-01

    Full Text Available Abstract Background Aging and dyslipidemia are processes which can lead to deleterious consequences to renal function. Therefore, the aim of this study was to determine the effects of both hypercholesterolemia and aging on renal function in mice. Methods Male hypercholesterolemic apolipoprotein E-deficient mice (ApoE, n = 13 and age-matched C57BL/6 control mice (C57, n = 15 were studied at 2 (young and 8 (adult month-old. At each time point, animals were placed in metabolic cages for 24 hours to urine volume and urinary creatinine quantification. Blood samples were collected for serum cholesterol, urea and creatinine measurements. Glomerular filtration rate (GFR was estimated through creatinine clearance determination. Mesangial expansion was evaluated by Periodic Acid Schiff staining, renal fibrosis was determined through Masson's trichrome staining and neuronal nitric oxide synthase (nNOS expression in the kidney was performed by Western Blotting. To statistical analysis two-way ANOVA followed by Fisher's post hoc test was used. Results Total plasma cholesterol was increased about 5-fold in ApoE mice at both time points compared to C57 animals. At 2-month-old, GFR was already markedly reduced in ApoE compared to C57 mice (187 ± 28 vs 358 ± 92 μL/min, p Conclusions These data show that both hypercholesterolemia and aging contribute to the loss of renal function in mice.

  13. THE TREE SHREW APOLIPOPROTEIN C-I cDNA: SEQUENCE AND ITS EXPRESSION

    Institute of Scientific and Technical Information of China (English)

    王克勤; 吕新跃; 吴钢; 薛红; 陈保生

    2001-01-01

    A rabbit anti-serum to tree shrew apolipoprotein C-I (apo C-l) was used to screen an expression cDNA li-braDy constructed by us from tree shrew (TS) liver tissue. Two apo C-I cDNA clones were obtained. The longerone consists of 380 nucleotides, including 21 bp and 95 bp at the 5' and 3' end of the non-translated region srespectively, and a 2 64-bp fragment in an open reading frame encoding 88 amino acids prepropeptide which con-ta-ins 26 amino acids of signal peptide and a mature protein (62 amino acids). Comparing the amino-acid se-quence deduced from this cDNA with those of the published mammalian apo C-Is reveals that it shared some struc-tural similarity with zat, mouse and dog apo C-l, but it had 5 more amino acids than that of human and baboon.The expression of apo C-I mRNA in 8 different tissues were also assayed with Northern blot. The results demonstrat-ed that liver had the highest expression, intestine had much less expression and no expression in other tissues,which is much different from human and other species. This study has laid down a good foundation for further study-ing on the function and the stucture of tree shrew apo C-I gene.``

  14. Apolipoprotein E polymorphisms increase the risk of post-stroke depression

    Institute of Scientific and Technical Information of China (English)

    Xue-bin Li; Jie Wang; An-ding Xu; Jian-min Huang; Lan-qing Meng; Rui-ya Huang; Jun-li Wang

    2016-01-01

    Recent reports have shown that apolipoprotein E (APOE) polymorphisms are involved in neurodegenerative disease. However, it is unclear whetherAPOE affects post-stroke depression. Accordingly, we hypothesized thatAPOE polymorphisms modify the risk of post-stroke depression. Here, we performed a hospital-based case-control study (including 76 cerebral infarction cases with post-stroke depression, 88 cerebral infarction cases without post-stroke depression, and 109 controls without any evidence of post-stroke depression or cerebral infarction) to determine possible association betweenAPOE rs429358 and rs7412 polymorphisms and risk of post-stroke depression. Our ifndings show no difference among the groups with regards genotype distribution of the rs7412 polymorphism. In contrast,APOE genotypes with rs429358-C alleles increased the risk of post-stroke depression. Further, the rs429358 polymorphism was associated with significantly decreased regional cerebral blood flow values in the left temporal lobe of post-stroke depression cases. Additionally, the rs429358 polymorphism was not only associated with depression severity, but with increasing serum levels of total cholesterol. These re-sults suggest that theAPOE rs429358 polymorphism is associated with increased risk of developing post-stroke depression, and thatAPOE rs429358-C allele genotypes may be detrimental to recovery of nerve function atfer stoke. Indeed, these ifndings provide clinical data for future post-stroke depression gene interventions.

  15. Correlation between haplotype of apolipoprotein B gene and natural longevity persons in Uygur Nationality

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This paper investigated the correlation between polymorphisms and haplotypes in the apolipoprotein B (apoB) gene (SP-I/D, XbaI-RFLP, VNTR) and natural longevity persons among the Uygur people in Xin-jiang. For this purpose, 191 healthy Uygur individuals aged above 90 from Hetian area of Xinjiang were recruited, and another 53 persons aged 65—70 from the same nationality, the same region and with the same gender ratio, served as the control group. Genotyping was performed by PCR-SSP, PCR-RFLP and PCR-sequencing methods. Logistic regression analyses revealed that the frequencies of X+X+ genotype, M and L alleles and the genetypes composed of M and L were significantly higher in the longevity group than in the control group. In haplotype analyses, we found that, in the long-lived people, the frequency of haplotypes composed of the X+ and M alleles was significantly higher whereas the frequency of haplotypes composed of the X- and S alleles was significantly lower (both P<0.05) I than those of their controls. These results indicated that the S allele, SS genotype and X+-S, D-S, D-X+-S haplotypes were the possible adverse factors, whereas the M, L alleles, X+X+, MM, ML, LL genotypes and I-X+-M, X+-M haplotypes were the possibe protective factors for the naturally long-lived Uygur people in China.

  16. Correlation between haplotype of apolipoprotein B gene and natural longevity persons in Uygur Nationality

    Institute of Scientific and Technical Information of China (English)

    JIANG WenXi; QIU ChangChun; CHENG ZuHeng; ZHOU WenYu; GU MingLiang; XU Qun; FANG MingWu; NIU WenQuan

    2007-01-01

    This paper investigated the correlation between polymorphisms and haplotypes in the apolipoprotein B (apoB) gene (SP-I/D, XbaI-RFLP, VNTR) and natural longevity persons among the Uygur people in Xinjiang. For this purpose, 191 healthy Uygur individuals aged above 90 from Hetian area of Xinjiang were recruited, and another 53 persons aged 65-70 from the same nationality, the same region and with the same gender ratio, served as the control group. Genotyping was performed by PCR-SSP, PCR-RFLP and PCR-sequencing methods. Logistic regression analyses revealed that the frequencies of X+X+ genotype, M and L alleles and the genetypes composed of M and L were significantly higher in the longevity group than in the control group. In haplotype analyses, we found that, in the long-lived people, the frequency of haplotypes composed of the X+ and M alleles was significantly higher whereas the frequency of haplotypes composed of the X- and S alleles was significantly lower (both P<0.05) I than those of their controls. These results indicated that the S allele, SS genotype and X+-S, D-S, D-X+-S haplotypes were the possible adverse factors, whereas the M, L alleles, X+X+, MM, ML, LL genotypes and I-X+-M, X+-M haplotypes were the possibe protective factors for the naturally long-lived Uygur people in China.

  17. Polymorphism of Apolipoprotein A5 is a Risk Factor for Cerebral Infarction in Type 2 Diabetes

    Institute of Scientific and Technical Information of China (English)

    Xuefeng LI; Yancheng XU; Yan DING; Chengming QIN; Zhe DAI; Li NIU

    2008-01-01

    This study investigated the association of apolipoprotein A5 (apoAS) gene polymorphism at position -113 ITC with cerebral infarction in patients with type 2 diabetes. A total of 256 type 2 diabetic patients without cerebral infarction (T2DM), 220 type 2 diabetic patients with cerebral infarction (T2DMCI) and 340 healthy subjects were recruited from the same region (Hubei province,China). The genotype of apoA5 -1131TC was analyzed by polymerase chain reaction, followed by restriction fragment length polymorphism (PCR-RFLP). Total cholesterol, HDL cholesterol,LDL-cholesterol and trigiycerides were quantitatively detected by using standard enzymatic techniques. The results showed that the prevalence of the apoA5 -1131C allele was significantly higher in T2DMCI group than that in control group (42.7% versus 31.2%, P<0.01). The carriers of rare C allele had higher TG levels as compared with carders of common allele in the three groups (P<0.01). Logistic regression models, which were adjusted for age, gender, blood pressure, BMI, FBS, smoking,LDL-C and HDL-C, revealed that patients carrying the apoA5 -1131C allele and CC homozygotes were at high risk for T2DMCI. It was concluded that the apoA5 -ll31C allele variant is an independent genetic risk factor for T2DMCI.

  18. Apolipoprotein C-II and C-III metabolism in a kindred of familial hypobetalipoproteinemia

    Energy Technology Data Exchange (ETDEWEB)

    Malmendier, C.L.; Delcroix, C.; Lontie, J.F.; Dubois, D.Y. (Research Foundation on Atherosclerosis, Brussels (Belgium))

    1991-01-01

    Three affected members of a kindred with asymptomatic hypobetalipoproteinemia (HBL) showed low levels of triglycerides, low-density lipoprotein (LDL)-cholesterol, and apolipoproteins (apo) B, C-II, and C-III. Turnover of iodine-labeled apo C-II and apo C-III associated in vitro to plasma lipoproteins was studied after intravenous injection. Radioactivity in plasma and lipoproteins (95% recovered in high-density lipoprotein (HDL) density range) and in 24-hour urine samples was observed for 16 days. A parallelism of the slowest slopes of plasma decay curves was observed between apo C-II and apo C-III, indicating a partial common catabolic route. Urine/plasma radioactivity ratio (U/P) varied with time, suggesting heterogeneity of metabolic pathways. A new compartmental model using the SAAM program was built, not only fitting simultaneously plasma and urine data, but also taking into account the partial common metabolism of lipoprotein particles (LP) containing apo C-II and apo C-III. The low apo C-II and C-III plasma concentrations observed in HBL compared with normal resulted from both an increased catabolism and a reduced synthesis, these changes being more marked for apo C-III. The modifications in the rate constants of the different pathways calculated from the new model are in favor of an increased direct removal of particles following the fast pathway, likely in the very-low-density lipoprotein (VLDL) density range.

  19. Multiple reaction monitoring and multiple reaction monitoring cubed based assays for the quantitation of apolipoprotein F.

    Science.gov (United States)

    Kumar, Abhinav; Gangadharan, Bevin; Zitzmann, Nicole

    2016-10-15

    Apolipoprotein F (APO-F) is a novel low abundance liver fibrosis biomarker and its concentration decreases in human serum and plasma across liver fibrosis stages. Current antibody based assays for APO-F suffer from limitations such as unspecific binding, antibody availability and undetectable target if the protein is degraded; and so an antibody-free assay has the potential to be a valuable diagnostic tool. We report an antibody-free, rapid, sensitive, selective and robust LC-MS/MS (MRM and MRM(3)) method for the detection and quantitation of APO-F in healthy human plasma. With further analysis of clinical samples, this LC-MS based method could be established as the first ever antibody-free biomarker assay for liver fibrosis. We explain the use of Skyline software for peptide selection and the creation of a reference library to aid in true peak identification of endogenous APO-F peptides in digests of human plasma without protein or peptide enrichment. Detection of a glycopeptide using MRM-EPI mode and reduction of interferences using MRM3 are explained. The amount of APO-F in human plasma from a healthy volunteer was determined to be 445.2ng/mL, the coefficient of variation (CV) of precision for 20 injections was <12% and the percentage error of each point along the calibration curve was calculated to be <8%, which is in line with the assay requirements for clinical samples.

  20. Safe domain and elementary geometry

    CERN Document Server

    Richard, J M

    2004-01-01

    A classical problem of mechanics involves a projectile fired from a given point with a given velocity whose direction is varied. This results in a family of trajectories whose envelope defines the border of a 'safe' domain. In the simple cases of a constant force, harmonic potential and Kepler or Coulomb motion, the trajectories are conic curves whose envelope in a plane is another conic section which can be derived either by simple calculus or by geometrical considerations. The case of harmonic forces reveals a subtle property of the maximal sum of distances within an ellipse.

  1. The C1 domain-targeted isophthalate derivative HMI-1b11 promotes neurite outgrowth and GAP-43 expression through PKCα activation in SH-SY5Y cells.

    Science.gov (United States)

    Talman, Virpi; Amadio, Marialaura; Osera, Cecilia; Sorvari, Salla; Boije Af Gennäs, Gustav; Yli-Kauhaluoma, Jari; Rossi, Daniela; Govoni, Stefano; Collina, Simona; Ekokoski, Elina; Tuominen, Raimo K; Pascale, Alessia

    2013-07-01

    Protein kinase C (PKC) is a family of serine/threonine phosphotransferases ubiquitously expressed and involved in multiple cellular functions, such as proliferation, apoptosis and differentiation. The C1 domain of PKC represents an attractive drug target, especially for developing PKC activators. Dialkyl 5-(hydroxymethyl)isophthalates are a novel group of synthetic C1 domain ligands that exhibit antiproliferative effect in HeLa cervical carcinoma cells. Here we selected two isophthalates, HMI-1a3 and HMI-1b11, and characterized their effects in the human neuroblastoma cell line SH-SY5Y. Both of the active isophthalates exhibited significant antiproliferative and differentiation-inducing effects. Since HMI-1b11 did not impair cell survival even at the highest concentration tested (20μM), and supported neurite growth and differentiation of SH-SY5Y cells, we focused on studying its downstream signaling cascades and effects on gene expression. Consistently, genome-wide gene expression microarray and gene set enrichment analysis indicated that HMI-1b11 (10μM) induced changes in genes mainly related to cell differentiation. In particular, further studies revealed that HMI-1b11 exposure induced up-regulation of GAP-43, a marker for neurite sprouting and neuronal differentiation. These effects were induced by a 7-min HMI-1b11 treatment and specifically depended on PKCα activation, since pretreatment with the selective inhibitor Gö6976 abolished the up-regulation of GAP-43 protein observed at 12h. In parallel, we found that a 7-min exposure to HMI-1b11 induced PKCα accumulation to the cytoskeleton, an effect that was again prevented by pretreatment with Gö6976. Despite similar binding affinities to PKC, the isophthalates had different effects on PKC-dependent ERK1/2 signaling: HMI-1a3-induced ERK1/2 phosphorylation was transient, while HMI-1b11 induced a rapid but prolonged ERK1/2 phosphorylation. Overall our data are in accordance with previous studies showing that

  2. Design PID controllers for desired time-domain or frequency-domain response.

    Science.gov (United States)

    Zhang, Weidong; Xi, Yugeng; Yang, Genke; Xu, Xiaoming

    2002-10-01

    Practical requirements on the design of control systems, especially process control systems, are usually specified in terms of time-domain response, such as overshoot and rise time, or frequency-domain response, such as resonance peak and stability margin. Although numerous methods have been developed for the design of the proportional-integral-derivative (PID) controller, little work has been done in relation to the quantitative time-domain and frequency-domain responses. In this paper, we study the following problem: Given a nominal stable process with time delay, we design a suboptimal PID controller to achieve the required time-domain response or frequency-domain response for the nominal system or the uncertain system. An H(infinity) PID controller is developed based on optimal control theory and the parameters are derived analytically. Its properties are investigated and compared with that of two developed suboptimal controllers: an H2 PID controller and a Maclaurin PID controller. It is shown that all three controllers can provide the quantitative time-domain and frequency-domain responses.

  3. On fictitious domain formulations for Maxwell's equations

    DEFF Research Database (Denmark)

    Dahmen, W.; Jensen, Torben Klint; Urban, K.

    2003-01-01

    We consider fictitious domain-Lagrange multiplier formulations for variational problems in the space H(curl: Omega) derived from Maxwell's equations. Boundary conditions and the divergence constraint are imposed weakly by using Lagrange multipliers. Both the time dependent and time harmonic...... formulations of the Maxwell's equations are considered. and we derive well-posed formulations for both cases. The variational problem that arises can be discretized by functions that do not satisfy an a-priori divergence constraint....

  4. Frustratingly Easy Domain Adaptation

    CERN Document Server

    Daumé, Hal

    2009-01-01

    We describe an approach to domain adaptation that is appropriate exactly in the case when one has enough ``target'' data to do slightly better than just using only ``source'' data. Our approach is incredibly simple, easy to implement as a preprocessing step (10 lines of Perl!) and outperforms state-of-the-art approaches on a range of datasets. Moreover, it is trivially extended to a multi-domain adaptation problem, where one has data from a variety of different domains.

  5. Staggered domain wall fermions

    CERN Document Server

    Hoelbling, Christian

    2016-01-01

    We construct domain wall fermions with a staggered kernel and investigate their spectral and chiral properties numerically in the Schwinger model. In some relevant cases we see an improvement of chirality by more than an order of magnitude as compared to usual domain wall fermions. Moreover, we present first results for four-dimensional quantum chromodynamics, where we also observe significant reductions of chiral symmetry violations for staggered domain wall fermions.

  6. Translation domains in multiferroics

    OpenAIRE

    Meier, D; Leo, N; Jungk, T.; Soergel, E.; Becker, P.; Bohaty, L.; Fiebig, M.

    2010-01-01

    Translation domains differing in the phase but not in the orientation of the corresponding order parameter are resolved in two types of multiferroics. Hexagonal (h-) YMnO$_3$ is a split-order-parameter multiferroic in which commensurate ferroelectric translation domains are resolved by piezoresponse force microscopy whereas MnWO$_4$ is a joint-order-parameter multiferroic in which incommensurate magnetic translation domains are observed by optical second harmonic generation. The pronounced ma...

  7. Pragmatic circuits frequency domain

    CERN Document Server

    Eccles, William

    2006-01-01

    Pragmatic Circuits: Frequency Domain goes through the Laplace transform to get from the time domain to topics that include the s-plane, Bode diagrams, and the sinusoidal steady state. This second of three volumes ends with a-c power, which, although it is just a special case of the sinusoidal steady state, is an important topic with unique techniques and terminology. Pragmatic Circuits: Frequency Domain is focused on the frequency domain. In other words, time will no longer be the independent variable in our analysis. The two other volumes in the Pragmatic Circuits series include titles on DC

  8. Influence of Isoforms and Carboxyl-Terminal Truncations on the Capacity of Apolipoprotein E To Associate with and Activate Phospholipid Transfer Protein.

    Science.gov (United States)

    Dafnis, Ioannis; Metso, Jari; Zannis, Vassilis I; Jauhiainen, Matti; Chroni, Angeliki

    2015-09-29

    Phospholipid transfer protein (PLTP), a main protein in lipid and lipoprotein metabolism, exists in high-activity (HA-PLTP) and low-activity (LA-PLTP) forms in human plasma. Proper phospholipid transfer activity of PLTP is modulated by interactions with various apolipoproteins (apo) including apoE. The domains of apoE involved in interactions with PLTP are not known. Here we analyzed the capacity of recombinant apoE isoforms and apoE4 mutants with progressive carboxyl-terminal deletions to bind to and activate HA-PLTP and LA-PLTP. Our analyses demonstrated that lipid-free apoE isoforms bind to both HA-PLTP and LA-PLTP, resulting in phospholipid transfer activation, with apoE3 inducing the highest PLTP activation. The isoform-specific differences in apoE/PLTP binding and PLTP activation were abolished following apoE lipidation. Lipid-free apoE4[Δ(260-299)], apoE4[Δ(230-299)], apoE4[Δ(203-299)], and apoE4[Δ(186-299)] activated HA-PLTP by 120-160% compared to full-length apoE4. Lipid-free apoE4[Δ(186-299)] also activated LA-PLTP by 85% compared to full-length apoE4. All lipidated truncated apoE4 forms displayed a similar effect on HA-PLTP and LA-PLTP activity as full-length apoE4. Strikingly, lipid-free or lipidated full-length apoE4 and apoE4[Δ(186-299)] demonstrated similar binding capacity to LA-PLTP and HA-PLTP. Biophysical studies showed that the carboxyl-terminal truncations of apoE4 resulted in small changes of the structural or thermodynamic properties of lipidated apoE4, that were much less pronounced compared to changes observed previously for lipid-free apoE4. Overall, our findings show an isoform-dependent binding to and activation of PLTP by lipid-free apoE. Furthermore, the domain of apoE4 required for PLTP activation resides within its amino-terminal 1-185 region. The apoE/PLTP interactions can be modulated by the conformation and lipidation state of apoE.

  9. Visualizing domain wall and reverse domain superconductivity.

    Science.gov (United States)

    Iavarone, M; Moore, S A; Fedor, J; Ciocys, S T; Karapetrov, G; Pearson, J; Novosad, V; Bader, S D

    2014-08-28

    In magnetically coupled, planar ferromagnet-superconductor (F/S) hybrid structures, magnetic domain walls can be used to spatially confine the superconductivity. In contrast to a superconductor in a uniform applied magnetic field, the nucleation of the superconducting order parameter in F/S structures is governed by the inhomogeneous magnetic field distribution. The interplay between the superconductivity localized at the domain walls and far from the walls leads to effects such as re-entrant superconductivity and reverse domain superconductivity with the critical temperature depending upon the location. Here we use scanning tunnelling spectroscopy to directly image the nucleation of superconductivity at the domain wall in F/S structures realized with Co-Pd multilayers and Pb thin films. Our results demonstrate that such F/S structures are attractive model systems that offer the possibility to control the strength and the location of the superconducting nucleus by applying an external magnetic field, potentially useful to guide vortices for computing application.

  10. Qp-spaces on bounded symmetric domains

    Directory of Open Access Journals (Sweden)

    Jonathan Arazy

    2008-01-01

    Full Text Available We generalize the theory of Qp spaces, introduced on the unit disc in 1995 by Aulaskari, Xiao and Zhao, to bounded symmetric domains in Cd, as well as to analogous Moebius-invariant function spaces and Bloch spaces defined using higher order derivatives; the latter generalization contains new results even in the original context of the unit disc.

  11. Body Mass Index, Blood Lipid and Apolipoprotein levels and Coronary Heart Disease among middle aged Punjabi Khatris of Northwest India

    Directory of Open Access Journals (Sweden)

    Tripta*

    2013-10-01

    Full Text Available Background: Studies have suggested that an elevated plasma concentration of apolipoprotein (apo B coupled with obesity may be considered as an important risk factor for coronary heart disease (CHD than the traditional lipid factors. Coronary artery disease (CAD is a multifactorial disease resulting from interaction among various hereditary, cultural and environment factors. Population specific studies are rare. Aim: The aim of this study was to evaluate the association of body mass index (BMI, blood lipids and apolipoproteins with the CAD among the Khatri caste, which is an indigenous population of Northwest India. Materials and Methods: The study was carried on 150 CAD patients and 150 normal controls belonging to the Punjabi Khatri caste ranging in age from 35-45 years. Height and body weight was measured using standard techniques. Blood was drawn from each subject to analyze serum concentrations of lipids and apolipoproteins. Results: The study demonstrated that CAD patients had elevated BMI in both males and females than normal controls. Apo B levels were an important predictor of CAD. ApoA/ApoB ratio among CAD patients was 0.74 compared with 1.53 in normal subjects; controls had 105.79% higher ApoA/ApoB ratio than CAD subjects. Total cholesterol, LDL-C, triglycerides, LDL-C/HDL-C ratio of the two groups also showed significant differences. Prevalence of obesity in CAD patients was 70.7% compared with 10% in normal controls. Conclusions: Apo B levels were found to the best predictor of CAD, even though significant differences were also found between CAD and normal subjects for other lipoprotein traits. Obesity was high CAD patients than normal controls.

  12. Influence of infant and juvenile diets on serum cholesterol, lipoprotein cholesterol, and apolipoprotein concentrations in juvenile baboons (Papio sp.).

    Science.gov (United States)

    Mott, G E; McMahan, C A; Kelley, J L; Farley, C M; McGill, H C

    1982-11-01

    The long-term effects of infant diet (breast milk or formula containing 2, 30, or 60 mg/dl cholesterol) and subsequent dietary cholesterol (1 mg/kcal) and fat (saturated or unsaturated) on serum lipid and apolipoprotein concentrations were estimated using 82 juvenile baboons 4-6 years of age. A significant interaction of infant diet (breast vs formula) with type of fat (saturated vs unsaturated) at 4-6 years of age was observed on HDL cholesterol and apolipoprotein A-I (apoA-I) concentrations. That is, animals breast-fed as infants had higher HDL cholesterol and apoA-I concentrations when fed unsaturated fat from weaning to 4-6 years of age than those fed saturated fat (77 vs 68 mg/dl). In contrast, animals fed formulas in infancy followed by a diet containing unsaturated fat had lower HDL cholesterol and apoA-I concentrations at 4-6 years of age than did those fed saturated fat (67 vs 78 mg/dl). However, breast feeding or feeding formulas containing various levels of cholesterol for 3 months during infancy did not result in statistically significant differences in total serum cholesterol, VLDL + LDL cholesterol and apolipoprotein B (apoB) concentrations. Dietary cholesterol after infancy significantly increased serum total cholesterol, VLDL + LDL and HDL cholesterol, apoA-I and apoB concentrations. All of these response variables also were higher in animals fed saturated fat compared to those fed unsaturated fat on the same level of cholesterol. At 4-6 years of age, regardless of diet, females had significantly higher serum VLDL + LDL cholesterol (57 vs 43 mg/dl) and apoB concentrations (39 vs 30 mg/dl) than did males.

  13. Loss of glial lazarillo, a homolog of apolipoprotein D, reduces lifespan and stress resistance in Drosophila.

    Science.gov (United States)

    Sanchez, Diego; López-Arias, Begoña; Torroja, Laura; Canal, Inmaculada; Wang, Xiaohui; Bastiani, Michael J; Ganfornina, Maria D

    2006-04-01

    The vertebrate Apolipoprotein D (ApoD) is a lipocalin secreted from subsets of neurons and glia during neural development and aging . A strong correlation exists between ApoD overexpression and numerous nervous system pathologies as well as obesity, diabetes, and many forms of cancer . However, the exact relationship between the function of ApoD and the pathophysiology of these diseases is still unknown. We have generated loss-of-function Drosophila mutants for the Glial Lazarillo (GLaz) gene , a homolog of ApoD in the fruit fly, mainly expressed in subsets of adult glial cells. The absence of GLaz reduces the organism's resistance to oxidative stress and starvation and shortens male lifespan. The mutant flies exhibit a smaller body mass due to a lower amount of neutral lipids stored in the fat body. Apoptotic neural cell death increases in aged flies or upon paraquat treatment, which also impairs neural function as assessed by behavioral tests. The higher sensitivity to oxidative stress and starvation and the reduced fat storage revert to control levels when a GFP-GLaz fusion protein is expressed under the control of the GLaz natural promoter. Finally, GLaz mutants have a higher concentration of lipid peroxidation products, pointing to a lipid peroxidation protection or scavenging as the mechanism of action for this lipocalin. In agreement with Walker et al. (, in this issue of Current Biology), who analyze the effects of overexpressing GLaz, we conclude that GLaz has a protective role in stress situations and that its absence reduces lifespan and accelerates neurodegeneration.

  14. Kaempferol regulates OPN-CD44 pathway to inhibit the atherogenesis of apolipoprotein E deficient mice

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Hong-Bo, E-mail: xhbzhb@yahoo.com [College of Veterinary Medicine, Hunan Agricultural University, Changsha 410128 (China); Lu, Xiang-Yang; Sun, Zhi-Liang [Hunan Agricultural University, Changsha 410128 (China); Zhang, Heng-Bo [Furong District Red Cross Hospital, Changsha 410126 (China)

    2011-12-15

    Recent studies show that osteopontin (OPN) and its receptor cluster of differentiation 44 (CD44) are two pro-inflammatory cytokines contributing to the development of atherosclerosis. The objective of this study was to explore the inhibitory effect of kaempferol, a naturally occurring flavonoid compound, on atherogenesis and the mechanisms involved. The experiments were performed in aorta and plasma from C57BL/6J control and apolipoprotein E-deficient (ApoE{sup -/-}) mice treated or not with kaempferol (50 or 100 mg/kg, intragastrically) for 4 weeks. Kaempferol treatment decreased atherosclerotic lesion area, improved endothelium-dependent vasorelaxation, and increased the maximal relaxation value concomitantly with decrease in the half-maximum effective concentration, plasma OPN level, aortic OPN expression, and aortic CD44 expression in ApoE{sup -/-} mice. In addition, treatment with kaempferol also significantly decreased reactive oxygen species production in mice aorta. The present results suggest that kaempferol regulates OPN-CD44 pathway to inhibit the atherogenesis of ApoE{sup -/-} mice. -- Graphical abstract: Kaempferol regulates OPN-CD44 pathway to inhibit the atherogenesis of ApoE{sup -/-} mice. Highlights: Black-Right-Pointing-Pointer OPN-CD44 pathway plays a critical role in the development of atherosclerosis. Black-Right-Pointing-Pointer We examine lesion area, OPN and CD44 changes after kaempferol treatment. Black-Right-Pointing-Pointer Kaempferol treatment decreased atherosclerotic lesion area in ApoE{sup -/-} mice. Black-Right-Pointing-Pointer Kaempferol treatment decreased aortic OPN and CD44 expressions in ApoE{sup -/-} mice. Black-Right-Pointing-Pointer Kaempferol regulates OPN-CD44 pathway to inhibit the atherogenesis.

  15. Intracellular maturation of apolipoprotein[a] and assembly of lipoprotein[a] in primary baboon hepatocytes.

    Science.gov (United States)

    White, A L; Rainwater, D L; Lanford, R E

    1993-03-01

    The glycoprotein apolipoprotein[a] (apo[a]) is present in plasma at highly variable concentrations and appears as a number of genetically determined size isoforms (400-800 kDa), disulfide linked to apoB-100 in low density lipoprotein to produce lipoprotein [a](Lp[a]). Apo[a] is synthesized by the liver, but the site of association of apo[a] and apoB and factors that regulate its production are unknown. To examine the morphogenesis of the Lp[a] particle, baboon hepatocytes expressing a single, low molecular weight isoform of apo[a] were labeled with [35S]cysteine and methionine, and apo[a] was analyzed by immunoprecipitation and SDS-PAGE. Steady-state labeling revealed two molecular weight forms of apo[a] inside the cell. Only the large form was recovered from the culture medium. Pulse-chase studies and endoglycosidase treatment revealed that the lower molecular weight form of apo[a] represented a precursor with a prolonged residence time in the endoplasmic reticulum or an early Golgi compartment, after which it was processed to the mature form. A proportion of the mature form of apo[a] was rapidly secreted after synthesis, whereas the remainder had a prolonged residence time in a late Golgi compartment. In all experiments, apoB co-precipitated with apo[a] from the culture medium, but not from cell lysates. Density gradient ultracentrifugation and immunoblot analysis revealed that the majority of apo[a] was secreted into the medium in a free form, suggesting that the association between apo[a] and apoB occurred after secretion. Regulation of the movement of apo[a] between intracellular compartments may be one mechanism by which the plasma levels of Lp[a] are influenced.

  16. Effects of Apolipoprotein E Isoforms in Diabetic Nephropathy of Chinese Type 2 Diabetic Patients

    Directory of Open Access Journals (Sweden)

    YongWei Jiang

    2017-01-01

    Full Text Available Diabetic nephropathy (DN is one of the major chronic complications of diabetes. Genetic polymorphism of Apolipoprotein E (ApoE has been proposed to participating in DN. The purpose of the study was to evaluate the relationship between ApoE genetic polymorphism and the presence of DN in Chinese type 2 diabetic patients. We studied 845 diabetic patients who were divided into DN group (n=429 and control group (n=416. ApoE genotype was determined by ApoE genotyping chip and the plasmatic biochemical characterization was performed on all subjects. There were differences (P<0.001 in HbA1c, creatinine, and urinary albumin between the two groups. The ApoE ε2 allelic frequency was 7.69% in DN group versus 3.49% in control group (OR = 2.22, 95% CI = 1.41–3.47, and P<0.05, as expected, ApoE E2/E2 and E2/E3 genotype frequency were higher in DN group (13.75% versus 6.49%, P<0.05. The ApoE ε4 allelic frequency was 7.93% in DN group versus 11.54% in control group (OR = 0.70, 95% CI = 0.50–0.97, and P<0.05, and DN group presented a lower frequency of ApoE E3/E4 and E4/E4 genotype frequency (14.91% versus 19.96%, P<0.05. These results suggest ApoE ε2 allele may be a risk factor; however ApoE ε4 allele may play a protective role of DN in Chinese type 2 diabetic patients.

  17. Effects of Apolipoprotein E Isoforms in Diabetic Nephropathy of Chinese Type 2 Diabetic Patients

    Science.gov (United States)

    Ma, Liang; Han, ChengWu; Liu, Qian; Cong, Xiao; Xu, YaPing; Zhao, TingTing

    2017-01-01

    Diabetic nephropathy (DN) is one of the major chronic complications of diabetes. Genetic polymorphism of Apolipoprotein E (ApoE) has been proposed to participating in DN. The purpose of the study was to evaluate the relationship between ApoE genetic polymorphism and the presence of DN in Chinese type 2 diabetic patients. We studied 845 diabetic patients who were divided into DN group (n = 429) and control group (n = 416). ApoE genotype was determined by ApoE genotyping chip and the plasmatic biochemical characterization was performed on all subjects. There were differences (P < 0.001) in HbA1c, creatinine, and urinary albumin between the two groups. The ApoE ε2 allelic frequency was 7.69% in DN group versus 3.49% in control group (OR = 2.22, 95% CI = 1.41–3.47, and P < 0.05), as expected, ApoE E2/E2 and E2/E3 genotype frequency were higher in DN group (13.75% versus 6.49%, P < 0.05). The ApoE ε4 allelic frequency was 7.93% in DN group versus 11.54% in control group (OR = 0.70, 95% CI = 0.50–0.97, and P < 0.05), and DN group presented a lower frequency of ApoE E3/E4 and E4/E4 genotype frequency (14.91% versus 19.96%, P < 0.05). These results suggest ApoE ε2 allele may be a risk factor; however ApoE ε4 allele may play a protective role of DN in Chinese type 2 diabetic patients. PMID:28326331

  18. Apolipoprotein E metabolism and functions in brain and its role in Alzheimer's disease

    Science.gov (United States)

    Liao, Fan; Yoon, Hyejin; Kim, Jungsu

    2017-01-01

    Purpose of review APOE4 genotype is the strongest genetic risk factor for Alzheimer's disease. Prevailing evidence suggests that amyloid β plays a critical role in Alzheimer's disease. The objective of this article is to review the recent findings about the metabolism of apolipoprotein E (ApoE) and amyloid β and other possible mechanisms by which ApoE contributes to the pathogenesis of Alzheimer's disease. Recent findings ApoE isoforms have differential effects on amyloid β metabolism. Recent studies demonstrated that ApoE-interacting proteins, such as ATP-binding cassette A1 (ABCA1) and LDL receptor, may be promising therapeutic targets for Alzheimer's disease treatment. Activation of liver X receptor and retinoid X receptor pathway induces ABCA1 and other genes, leading to amyloid β clearance. Inhibition of the negative regulators of ABCA1, such as microRNA-33, also induces ABCA1 and decreases the levels of ApoE and amyloid β. In addition, genetic inactivation of an E3 ubiquitin ligase, myosin regulatory light chain interacting protein, increases LDL receptor levels and inhibits amyloid accumulation. Although amyloid β-dependent pathways have been extensively investigated, there have been several recent studies linking ApoE with vascular function, neuroinflammation, metabolism, synaptic plasticity, and transcriptional regulation. For example, ApoE was identified as a ligand for a microglial receptor, TREM2, and studies suggested that ApoE may affect the TREM2-mediated microglial phagocytosis. Summary Emerging data suggest that ApoE affects several amyloid β-independent pathways. These underexplored pathways may provide new insights into Alzheimer's disease pathogenesis. However, it will be important to determine to what extent each mechanism contributes to the pathogenesis of Alzheimer's disease. PMID:27922847

  19. Apolipoprotein E expression and behavioral toxicity of high charge, high energy (HZE) particle radiation

    Energy Technology Data Exchange (ETDEWEB)

    Higuchi, Yoshinori; Nelson, G.A.; Slater, J.M.; Pearlstein, R.D. [Loma Linda Univ., CA (United States). Medical Center; Vazquez, M. [Brookhaven National Lab., Upton, NY (United States); Laskowitz, D.T. [Duke Univ., Durham, NC (United States). Medical Center

    2002-12-01

    Apolipoprotein E (apoE) is a lipid binding protein that plays an important role in tissue repair following brain injury. In the present studies, we have investigated whether apoE affects the behavioral toxicity of high charge, high energy (HZE) particle radiation. Sixteen male apoE knockout (KO) mice and sixteen genetically matched wild-type (WT) C57BL mice were used in this experiment. Half of the KO and half of the WT animals were irradiated with 600 MeV/amu iron particles (2 Gy whole body). The effect of irradiation on motor coordination and stamina (Rotarod test), exploratory behavior (open field test), and spatial working and reference memory (Morris water maze) was assessed. Rotarod test: Performance was adversely affected by radiation exposure in both KO and WT groups at 30 d after irradiation. By 60 d after radiation, the radiation effect was lost in WT, but still apparent in irradiated KO mice. Open field test: Radiation reduced open field exploratory activity 14, 28, 56, 84, and 168 d after irradiation of KO mice, but had no effect on WT mice. Morris water maze: Radiation adversely affected spatial working memory in the KO mice, but had no discernible effect in the WT mice as assessed 180 d after irradiation. In contrast, irradiated WT mice showed marked impairment of spatial reference memory in comparison to non-irradiated mice, while no effect of radiation was observed in KO mice. These studies show that apoE expression influences the behavioral toxicity of HZE particle radiation and suggest that apoE plays a role in the repair/recovery from radiation injury of the central nervous system (CNS). ApoE deficiency may exacerbate the previously reported effects of HZE particle radiation in accelerating the brain aging process. (author)

  20. Apolipoprotein D Transgenic Mice Develop Hepatic Steatosis through Activation of PPARγ and Fatty Acid Uptake.

    Directory of Open Access Journals (Sweden)

    Marilyne Labrie

    Full Text Available Transgenic mice (Tg overexpressing human apolipoprotein D (H-apoD in the brain are resistant to neurodegeneration. Despite the use of a neuron-specific promoter to generate the Tg mice, they expressed significant levels of H-apoD in both plasma and liver and they slowly develop hepatic steatosis and insulin resistance. We show here that hepatic PPARγ expression in Tg mice is increased by 2-fold compared to wild type (WT mice. Consequently, PPARγ target genes Plin2 and Cide A/C are overexpressed, leading to increased lipid droplets formation. Expression of the fatty acid transporter CD36, another PPARgamma target, is also increased in Tg mice associated with elevated fatty acid uptake as measured in primary hepatocytes. Elevated expression of AMPK in the liver of Tg leads to phosphorylation of acetyl CoA carboxylase, indicating a decreased activity of the enzyme. Fatty acid synthase expression is also induced but the hepatic lipogenesis measured in vivo is not significantly different between WT and Tg mice. In addition, expression of carnitine palmitoyl transferase 1, the rate-limiting enzyme of beta-oxidation, is slightly upregulated. Finally, we show that overexpressing H-apoD in HepG2 cells in presence of arachidonic acid (AA, the main apoD ligand, increases the transcriptional activity of PPARγ. Supporting the role of apoD in AA transport, we observed enrichment in hepatic AA and a decrease in plasmatic AA concentration. Taken together, our results demonstrate that the hepatic steatosis observed in apoD Tg mice is a consequence of increased PPARγ transcriptional activity by AA leading to increased fatty acid uptake by the liver.

  1. The effect of apolipoprotein E4 on synchronous neural interactions in brain cultures.

    Science.gov (United States)

    Christopoulos, Vassilios; Georgopoulos, Angeliki; Georgopoulos, Apostolos P

    2015-06-01

    In a previous study, we assessed the synchronous neural interactions (SNI) in a developing neural network in brain cultures on multielectrode arrays (Christopoulos et al. in J Neural Eng 9:046008, 2012). Here, we report on the effects of apolipoprotein E4 (apoE4) on these neural interactions. We carried out six experiments (five using rodent brain cultures and one using neuroblastoma cultures) in which we recorded local field potentials (LFP) from 59 sites for several days in vitro under the following conditions. In one experiment, we added to the culture media triglyceride (TG)-rich lipoproteins from a human subject with the apoE4/4 genotype, whereas in the other experiments, we added recombinant human apoE4. We found that SNI in the apoE4-treated cultures had higher coefficient of SNI variation, as compared to control cultures. These findings further document the role of SNI as a fundamental aspect of the dynamic organization of neural networks (Langheim et al. in Proc Natl Acad Sci USA 103:455-459, 2006. doi: 10.1073/pnas.0509623102 ; Georgopoulos et al. in J Neural Eng 4:349-355, 2007) and extend the effect of apoE4 on SNI (Leuthold et al. in Exp Brain Res 226:525-536, 2013) across different brain species (human, rodents), apoE source (TG-rich lipoproteins, recombinant), neural signals (MEG, LFP), and brain network (intact brain, developing brain in vitro). To our knowledge, this is the first study of the effects of apoE4 on neural network function in vitro.

  2. Apolipoprotein E4 allele and the risk of left ventricular dysfunction in thalassemia major

    Directory of Open Access Journals (Sweden)

    M Bazrgar

    2007-07-01

    Full Text Available Background: Left ventricular (LV failure is the main cause of death in thalassemia. Iron overload in thesepatients leads to formation of oxygen free radicals. Apolipoprotein (ApoE E4 allele is the least efficient inoxidative stress condition compared with apoE2 and apoE3 alleles. This study was performed to determinethe association of three different ApoE alleles with LV dysfunction in thalassemia major patients in southernIran.Methods: The present study comprised 202 patients with thalassemia major divided into three groups accordingto echocardiographic findings: Group 1 (n=135 had no cardiac impairment; Group 2 (n=38 exhibitedLV dilatation but normal LV systolic function and Group 3 (n=29 showed LV systolic dysfunction.DNA was obtained from all patients and 198 healthy control subjects for ApoE genotyping.Results: Frequency of both apoE3/E4 genotype and apoE4 allele in Group 3 were higher than the controlgroup with corresponding values of P<0.05, Odds Ratio=2.97, 1.06<8.32 and P<0.01, OR=3.01,1.15<7.69, respectively and confidence Interval of 95%. There were no differences observed betweencontrols and patient groups in relation to other genotype and allele frequencies. Interventricular septumthickness and LV end diastolic diameter in apoE4/- patients were more than those of apoE3/E3 patients.Conclusion: ApoE4 allele increases the risk of LV impairment in thalassemia major.

  3. Apolipoprotein E4 frequencies in a Japanese population with Alzheimer's disease and dementia with Lewy bodies.

    Directory of Open Access Journals (Sweden)

    Seiju Kobayashi

    Full Text Available BACKGROUND: The apolipoprotein E (APOE ε4 allele has been reported to be a risk factor for Alzheimer's disease (AD and dementia with Lewy bodies (DLB. Previous neuropathological studies have demonstrated similar frequencies of the APOE ε4 allele in AD and DLB. However, the few ante-mortem studies on APOE allele frequencies in DLB have shown lower frequencies than post-mortem studies. One reason for this may be inaccuracy of diagnosis. We examined APOE genotypes in subjects with AD, DLB, and a control group using the latest diagnostic criteria and MRI, SPECT, and MIBG myocardial scintigraphy. METHODS: The subjects of this study consisted of 145 patients with probable AD, 50 subjects with probable DLB, and a control group. AD subjects were divided into two groups based on age of onset: early onset AD (EOAD and late onset AD (LOAD. All subjects had characteristic features on MRI, SPECT, and/or myocardial scintigraphy. RESULTS: The rate of APOE4 carrier status was 18.3% and the frequency of the ε4 allele was 9.7% in controls. The rate of APOE4 carrier status and the frequency of the ε4 allele were 47% and 27% for LOAD, 50% and 31% for EOAD, and 42% and 31% for DLB, respectively. CONCLUSION: The APOE4 genotypes in this study are consistent with previous neuropathological studies suggesting accurate diagnosis of AD and DLB. APOE4 genotypes were similar in AD and DLB, giving further evidence that the ε4 allele is a risk factor for both disorders.

  4. In vivo human apolipoprotein E isoform fractional turnover rates in the CNS.

    Directory of Open Access Journals (Sweden)

    Kristin R Wildsmith

    Full Text Available Apolipoprotein E (ApoE is the strongest genetic risk factor for Alzheimer's disease and has been implicated in the risk for other neurological disorders. The three common ApoE isoforms (ApoE2, E3, and E4 each differ by a single amino acid, with ApoE4 increasing and ApoE2 decreasing the risk of Alzheimer's disease (AD. Both the isoform and amount of ApoE in the brain modulate AD pathology by altering the extent of amyloid beta (Aβ peptide deposition. Therefore, quantifying ApoE isoform production and clearance rates may advance our understanding of the role of ApoE in health and disease. To measure the kinetics of ApoE in the central nervous system (CNS, we applied in vivo stable isotope labeling to quantify the fractional turnover rates of ApoE isoforms in 18 cognitively-normal adults and in ApoE3 and ApoE4 targeted-replacement mice. No isoform-specific differences in CNS ApoE3 and ApoE4 turnover rates were observed when measured in human CSF or mouse brain. However, CNS and peripheral ApoE isoform turnover rates differed substantially, which is consistent with previous reports and suggests that the pathways responsible for ApoE metabolism are different in the CNS and the periphery. We also demonstrate a slower turnover rate for CSF ApoE than that for amyloid beta, another molecule critically important in AD pathogenesis.

  5. Liver expression of steroid hormones and Apolipoprotein D receptors in hepatocellular carcinoma

    Institute of Scientific and Technical Information of China (English)

    FJ Vizoso; L Rodrigo; M Rodriguez; A Altadill; ML González-Diéguez; A Linares; LO González; S Junquera; F Fresno-Forcelledo; MD Corte

    2007-01-01

    AIM: To evaluate the tissular expression of Androgen (A), Estrogen (E) and Progesterone (Pg) receptors, and Apolipoprotein D (ApoD), in liver tumors from resected hepatocellular carcinoma (HCC) cases in order to assess their possible relationship to prognosis.METHODS We performed an immunohistochemical study using tissue microarrays (containing more than 260 cancer specimens, from 31 HCC patients and controls)to determine the presence of specific antibodies against AR, ER, PgR and ApoD, correlating their findings with several clinico-pathological and biological variables. The staining results were categorized using a semi-quantitive score based on their intensity, and the percentage of immunostained cells was measured.RESULTS: A total of 21 liver tumors (67.7%) were positive for AR; 16 (51.6%) for ER; 26 (83.9%) for PgR and 12 (38.7%) stained for ApoD. We have found a wide variability in the immunostaining score values for each protein, with a median (range) of 11.5 (11.5-229.5) for AR; 11.1 (8.5-65) for ER; 14.2 (4-61) for PgR; and 37.7 (13.8-81.1) for ApoD. A history of heavy ethanol consumption, correlated positively with AR and PgR and negatively with ER status. HCV chronic infection also correlated positively with AR and PgR status. However,the presence of ApoD immunostaining did not correlate with any of these variables. Tumors with a positive immuno-staining for PgR showed a better prognosis.CONCLUSION: Our results indicate a moderate clinical value of the steroid receptor status in HCC, emphasizing the need to perform further studies in order to evaluate the possible role of new hormonal-based therapies.

  6. Relevance of apolipoprotein E4 for the lipid profile of Brazilian patients with coronary artery disease

    Directory of Open Access Journals (Sweden)

    D.R.S. Souza

    2007-02-01

    Full Text Available Apolipoprotein E (apoE - e2, e3, e4 alleles plays a role in the regulation of lipid metabolism, with the e4 considered to be a risk factor for coronary artery disease (CAD. We aimed to evaluate the apoE polymorphisms in Brazilians with CAD and their influence on the lipid profile and other risk factors (hypertension, diabetes mellitus, smoking. Two hundred individuals were examined: 100 patients with atherosclerosis confirmed by coronary angiography and 100 controls. Blood samples were drawn to determine apoE polymorphisms and lipid profile. As expected, the e3 allele was prevalent in the CAD (0.87 and non-CAD groups (0.81; P = 0.099, followed by the e4 allele (0.09 and 0.14, respectively; P = 0.158. The e3/3 (76 and 78% and e3/4 (16 and 23% were the most common genotypes for patients and controls, respectively. The lipid profile was altered in patients compared to controls (P < 0.05, independently of the e4 allele. However, in the controls this allele was prevalent in individuals with elevated LDL-cholesterol levels only (odds ratio = 2.531; 95% CI = 1.028-6.232. The frequency of risk factors was higher in the CAD group (P < 0.05, but their association with the lipid profile was not demonstrable in e4 carriers. In conclusion, the e4 allele is not associated with CAD or lipid profile in patients with atherosclerosis. However, its frequency in the non-CAD group is associated with increased levels of LDL-cholesterol, suggesting an independent effect of the e4 allele on lipid profile when the low frequency of other risk factors in this group is taken into account.

  7. Effects of simvastatin on apolipoprotein M in vivo and in vitro

    Directory of Open Access Journals (Sweden)

    Nilsson-Ehle Peter

    2011-07-01

    Full Text Available Abstract Objective To investigate effects of lipid lowering drug, simvastatin, on apolipoprotein M expression in the hyperlipidemic mice and in hepatic cell line, HepG2 cells. Methods Swiss male mice were randomly divided into the high fat group and control group, and were intragastrically fed with 0.9% saline (control group or lipid emulsion (high fat group at the daily dosage of 15 ml/kg body weight, respectively. After 8 weeks feeding, the hyperlipidemic model was successfully induced and these hyperlipidemic mice were then randomly divided into three experimental groups: vehicle control group, high-dose simvastatin-treated group (100 mg/kg body weight, and low-dose simvastatin-treated group (10 mg/kg body weight. Mice were dosed daily for 6 weeks of simvastatin before mice were sacrificed for determining serum lipid profile and apoM protein levels that was determined by using dot blotting analysis. Effects of simvastatin on apoM mRNA expression in the HepG2 cells were determined by real-time RT-PCR. Results Comparing to high fat model mice without simvastatin treatment, 100 mg/kg simvastatin could significantly increase serum total cholesterol (P P Conclusion The present study suggested that simvastatin, in vivo, had no effect on apoM levels in the hyperlipidemic mouse model. ApoM serum levels in mice were significantly correlated to the animal's age, whereas in cell cultures simvastatin does inhibit apoM expression in the HepG2 cells. The mechanism behind it is not known yet.

  8. Effect of peripheral administration of cholecystokinin on food intake in apolipoprotein AIV knockout mice.

    Science.gov (United States)

    Yoshimichi, Go; Lo, Chunmin C; Tamashiro, Kellie L K; Ma, Liyun; Lee, Dana M; Begg, Denovan P; Liu, Min; Sakai, Randall R; Woods, Stephen C; Yoshimatsu, Hironobu; Tso, Patrick

    2012-06-01

    Apolipoprotein AIV (apo AIV) and cholecystokinin (CCK) are satiation factors secreted by the small intestine in response to lipid meals. Apo AIV and CCK-8 has an additive effect to suppress food intake relative to apo AIV or CCK-8 alone. In this study, we determined whether CCK-8 (1, 3, or 5 μg/kg ip) reduces food intake in fasted apo AIV knockout (KO) mice as effectively as in fasted wild-type (WT) mice. Food intake was monitored by the DietMax food system. Apo AIV KO mice had significantly reduced 30-min food intake following all doses of CCK-8, whereas WT mice had reduced food intake only at doses of 3 μg/kg and above. Post hoc analysis revealed that the reduction of 10-min and 30-min food intake elicited by each dose of CCK-8 was significantly larger in the apo AIV KO mice than in the WT mice. Peripheral CCK 1 receptor (CCK1R) gene expression (mRNA) in the duodenum and gallbladder of the fasted apo AIV KO mice was comparable to that in WT mice. In contrast, CCK1R mRNA in nodose ganglia of the apo AIV KO mice was upregulated relative to WT animals. Similarly, upregulated CCK1R gene expression was found in the brain stem of apo AIV KO mice by in situ hybridization. Although it is possible that the increased satiating potency of CCK in apo AIV KO mice is mediated by upregulation of CCK 1R in the nodose ganglia and nucleus tractus solitarius, additional experiments are required to confirm such a mechanism.

  9. Synergistic effects of high fat feeding and apolipoprotein E deletion on enterocytic amyloid-beta abundance

    Directory of Open Access Journals (Sweden)

    Dhaliwal Satvinder S

    2008-04-01

    Full Text Available Abstract Background Amyloid-β (Aβ, a key protein found in amyloid plaques of subjects with Alzheimer's disease is expressed in the absorptive epithelial cells of the small intestine. Ingestion of saturated fat significantly enhances enterocytic Aβ abundance whereas fasting abolishes expression. Apolipoprotein (apo E has been shown to directly modulate Aβ biogenesis in liver and neuronal cells but it's effect in enterocytes is not known. In addition, apo E modulates villi length, which may indirectly modulate Aβ as a consequence of differences in lipid absorption. This study compared Aβ abundance and villi length in wild-type (WT and apo E knockout (KO mice maintained on either a low-fat or high-fat diet. Wild-type C57BL/6J and apo E KO mice were randomised for six-months to a diet containing either 4% (w/w unsaturated fats, or chow comprising 16% saturated fats and 1% cholesterol. Quantitative immunohistochemistry was used to assess Aβ abundance in small intestinal enterocytes. Apo E KO mice given the low-fat diet had similar enterocytic Aβ abundance compared to WT controls. Results The saturated fat diet substantially increased enterocytic Aβ in WT and in apo E KO mice, however the effect was greater in the latter. Villi height was significantly greater in apo E KO mice than for WT controls when given the low-fat diet. However, WT mice had comparable villi length to apo E KO when fed the saturated fat and cholesterol enriched diet. There was no effect of the high-fat diet on villi length in apo E KO mice. Conclusion The findings of this study are consistent with the notion that lipid substrate availability modulates enterocytic Aβ. Apo E may influence enterocytic lipid availability by modulating absorptive capacity.

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

    Science.gov (United States)

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

    2015-04-24

    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.

  11. Alimentary lipemia: plasma high-density lipoproteins and apolipoproteins CII and CIII in healthy subjects.

    Science.gov (United States)

    Kashyap, M L; Barnhart, R L; Srivastava, L S; Perisutti, G; Allen, C; Hogg, E; Glueck, C J; Jackson, R L

    1983-02-01

    Three healthy male and three female inpatient volunteers consumed isocaloric diets for 4 wk. At weekly intervals, a fatty meal (100 g fat) was consumed by each fasting subject and blood drawn at 2 h intervals for 12 h. Of the four oral fat loads, two contained saturated fat (polyunsaturated/saturated fat ratio = 0.34) and two contained unsaturated fat (polyunsaturated/saturated fat = 2.21). The magnitude of alimentary lipemia, expressed as area under the plasma triglyceride curve, was 3- to 4-fold higher in males than females. Alimentary lipemia was inversely related to the subjects' fasting plasma high-density lipoprotein (HDL)-cholesterol, HDL apolipoprotein (apo) CIII and directly related to plasma triglycerides. The P/S ratios of the daily diet or the fat meal did not significantly influence the plasma triglyceride curve. After fat intake, mean (+/- SEM) plasma total apoCII and CIII fell to 54 +/- 20% and 73 +/- 5% of base-line, respectively, at 12 h in five of six subjects. After oral fat, an initial fall and a subsequent rise in apoCII and CIII in HDL was associated with reciprocal changes in apoC concentrations in very low-density lipoproteins. We speculate from the data that 1) plasma HDL and their apoC concentrations are important determinants of chylomicron clearance and 2) transfer of apoCs from HDL to triglyceride-rich lipoproteins in the early phase of fat absorption does not result in the total recycling of apoCs from these lipoproteins to HDL during the late phase of alimentary lipemia.

  12. Apolipoprotein E4 impairs macrophage efferocytosis and potentiates apoptosis by accelerating endoplasmic reticulum stress.

    Science.gov (United States)

    Cash, James G; Kuhel, David G; Basford, Joshua E; Jaeschke, Anja; Chatterjee, Tapan K; Weintraub, Neal L; Hui, David Y

    2012-08-10

    Apolipoprotein (apo) E4 is a major genetic risk factor for a wide spectrum of inflammatory metabolic diseases, including atherosclerosis, diabetes, and Alzheimer disease. This study compared diet-induced adipose tissue inflammation as well as functional properties of macrophages isolated from human APOE3 and APOE4 mice to identify the mechanism responsible for the association between apoE4 and inflammatory metabolic diseases. The initial study confirmed previous reports that APOE4 gene replacement mice were less sensitive than APOE3 mice to diet-induced body weight gain but exhibited hyperinsulinemia, and their adipose tissues were similarly inflamed as those in APOE3 mice. Peritoneal macrophages isolated from APOE4 mice were defective in efferocytosis compared with APOE3 macrophages. Increased cell death was also observed in APOE4 macrophages when stimulated with LPS or oxidized LDL. Western blot analysis of cell lysates revealed that APOE4 macrophages displayed elevated JNK phosphorylation indicative of cell stress even under basal culturing conditions. Significantly higher cell stress due mainly to potentiation of endoplasmic reticulum (ER) stress signaling was also observed in APOE4 macrophages after LPS and oxidized LDL activation. The defect in efferocytosis and elevated apoptosis sensitivity of APOE4 macrophages was ameliorated by treatment with the ER chaperone tauroursodeoxycholic acid. Taken together, these results showed that apoE4 expression causes macrophage dysfunction and promotes apoptosis via ER stress induction. The reduction of ER stress in macrophages may be a viable option to reduce inflammation and inflammation-related metabolic disorders associated with the apoE4 polymorphism.

  13. Relationship between apolipoprotein E, D10S1225 polymorphisms and late-onset Alzheimer's disease

    Institute of Scientific and Technical Information of China (English)

    ZHANG Tai-song; WANG Hua-qiao; WANG Wei-yi; HE Yun-shao; HUANG Shao-kuan

    2006-01-01

    Background There were some papers published in the Jonrnal of Science, December 2000 suggesting that one or more important susceptibility genes for late onset Alzheimer's disease (LOAD) were located on the long arm of chromosome 10. Linkage analysis showed maximum lod score close to D10S1225 loci, which indicated the loci might contribute to the etiology of Alzheimer's disease (AD). Methods Fifty-nine LOAD patients and 107 controls were recruited. Apolipoprotein E (ApoE) genotypes were determined by reverse dot blotting hybridization assay. The D10S1225 was genotyped by 12% nondenaturing polyacrylamide gels electrophoresis and analyzed by silver staining. Statistical analysis was used to compare genotype and allele distributions between LOAD group and control group for ApoE and D10S1225 polymorphisms.Results ApoE ε4 was significantly higher in LOAD group in comparison with the control group(χ2=6.530, P =0.011). Seven different alleles of D10S1225 have been identified. The length of these gene fragments were 178 bp, 181 bp, 184 bp, 187 bp, 190 bp, 193 bp, and 196 bp, respectively. A total of 21 different genotypes were observed. There was no relationship between D10S1225 polymorphism and LOAD (χ2=4.488, P>0.05). Conclusion This study suggests that ApoEε4 is a risk factor for LOAD, however, the results indicated that there is not any possible linkage for disequilibria with a nearby AD risk gene near D10S1225.

  14. Association of amyloid burden, brain atrophy and memory deficits in aged apolipoprotein ε4 mice.

    Science.gov (United States)

    Yin, Junxiang; Turner, Gregory H; Coons, Stephen W; Maalouf, Marwan; Reiman, Eric M; Shi, Jiong

    2014-03-01

    Apolipoprotein E ε4 allele (ApoE4) has been associated with increased risk of sporadic Alzheimer's disease (AD) and of conversion from mild cognitive impairment to AD. But the underlying mechanism of ApoE4 affecting brain atrophy and cognition is not fully understood. We investigated the effect of ApoE4 on amyloid beta (Aβ) protein burden and its correlation with the structure change of hippocampus and cortex, cognitive and behavioral changes in ApoE4 transgenic mice. Male ApoE4 transgenic mice and age-matched control mice at age 12 months and 24 months were tested in the Morris Water Maze (MWM). Brain volume changes (including whole brain, hippocampus, cortex, total ventricles and caudate putamen) were assessed by using small animal 7T-MRI. Aβ level was assessed by immunohistochemistry (IHC) and immunoprecipitation/western blot. In MWM, escape latency was longer and time spent in the target quadrant was shorter in aged ApoE4 mice (12- and 24-month-old), suggesting age- and ApoE4-dependent visuospatial deficits. Atrophy on MRI was prominent in the hippocampus (p=0.039) and cortex (p=0.013) of ApoE4 mice (24-month-old) as compared to age-matched control mice. IHC revealed elevated Aβ deposition in the hippocampus. Consistently, both soluble and insoluble Aβ aggregates were increased in aged ApoE4 mice. This increase was correlated inversely with hippocampal atrophy and cognitive deficits. These data give further evidence that ApoE4 plays an important role in brain atrophy and memory impairment by modulating amyloid production and deposition.

  15. Epistatic Interactions between apolipoprotein E and hemoglobin S Genes in regulation of malaria parasitemia.

    Directory of Open Access Journals (Sweden)

    Virginie Rougeron

    Full Text Available Apolipoprotein E is a monomeric protein secreted by the liver and responsible for the transport of plasma cholesterol and triglycerides. The APOE gene encodes 3 isoforms Ɛ4, Ɛ3 and Ɛ2 with APOE Ɛ4 associated with higher plasma cholesterol levels and increased pathogenesis in several infectious diseases (HIV, HSV. Given that cholesterol is an important nutrient for malaria parasites, we examined whether APOE Ɛ4 was a risk factor for Plasmodium infection, in terms of prevalence or parasite density. A cross sectional survey was performed in 508 children aged 1 to 12 years in Gabon during the wet season. Children were screened for Plasmodium spp. infection, APOE and hemoglobin S (HbS polymorphisms. Median parasite densities were significantly higher in APOE Ɛ4 children for Plasmodium spp. densities compared to non-APOE Ɛ4 children. When stratified for HbS polymorphisms, median Plasmodium spp. densities were significantly higher in HbAA children if they had an APOE Ɛ4 allele compared to those without an APOE Ɛ4 allele. When considering non-APOE Ɛ4 children, there was no quantitative reduction of Plasmodium spp. parasite densities for HbAS compared to HbAA phenotypes. No influence of APOE Ɛ4 on successful Plasmodium liver cell invasion was detected by multiplicity of infection. These results show that the APOE Ɛ4 allele is associated with higher median malaria parasite densities in children likely due to the importance of cholesterol availability to parasite growth and replication. Results suggest an epistatic interaction between APOE and HbS genes such that sickle cell trait only had an effect on parasite density in APOE Ɛ4 children. This suggests a linked pathway of regulation of parasite density involving expression of these genes. These findings have significance for understanding host determinants of regulation of malaria parasite density, the design of clinical trials as well as studies of co-infection with Plasmodium and other

  16. The apolipoprotein epsilon4 allele confers additional risk in children with familial hypercholesterolemia.

    Science.gov (United States)

    Wiegman, Albert; Sijbrands, Eric J G; Rodenburg, Jessica; Defesche, Joep C; de Jongh, Saskia; Bakker, Henk D; Kastelein, John J P

    2003-06-01

    Children with familial hypercholesterolemia (FH) exhibit substantial variance of LDL cholesterol. In previous studies, family members of children with FH were included, which may have influenced results. To avoid such bias, we studied phenotype in 450 unrelated children with FH and in 154 affected sib-pairs. In known families with classical FH, diagnosis was based on plasma LDL cholesterol above the age- and gender-specific 95th percentile. Girls had 0.47 +/- 0.15 mmol/L higher LDL cholesterol, compared with boys (p = 0.002). Also in girls, HDL cholesterol increased by 0.07 +/- 0.03 mmol/L per 5 y (pfor trend = 0.005); this age effect was not observed in boys. The distribution of apolipoprotein (apo) E genotypes was not significantly different between probands, their paired affected siblings, or a Dutch control population. Carriers with or without one epsilon4 allele had similar LDL and HDL cholesterol levels. Within the affected sib-pairs, the epsilon4 allele explained 72.4% of the variance of HDL cholesterol levels (-0.15 mmol/L, 95% confidence interval -0.24 to -0.05, p = 0.003). The effect of apoE4 on HDL cholesterol differed with an analysis based on probands or on affected sib-pairs. The affected sib-pair model used adjustment for shared environment, type of LDL receptor gene mutation, and a proportion of additional genetic factors and may, therefore, be more accurate in estimating effects of risk factors on complex traits. We conclude that the epsilon4 allele was associated with lower HDL cholesterol levels in an affected sib-pair analysis, which strongly suggests that apoE4 influences HDL cholesterol levels in FH children. Moreover, the strong association suggests that apoE4 carries an additional disadvantage for FH children.

  17. Apolipoprotein B100 is required for hepatitis C infectivity and Mipomersen inhibits hepatitis C

    Science.gov (United States)

    Schaefer, Esperance A K; Meixiong, James; Mark, Christina; Deik, Amy; Motola, Daniel L; Fusco, Dahlene; Yang, Andrew; Brisac, Cynthia; Salloum, Shadi; Lin, Wenyu; Clish, Clary B; Peng, Lee F; Chung, Raymond T

    2016-01-01

    AIM To characterize the role of apolipoprotein B100 (apoB100) in hepatitis C viral (HCV) infection. METHODS In this study, we utilize a gene editing tool, transcription activator-like effector nucleases (TALENs), to generate human hepatoma cells with a stable genetic deletion of APOB to assess of apoB in HCV. Using infectious cell culture-competent HCV, viral pseudoparticles, replicon models, and lipidomic analysis we determined the contribution of apoB to each step of the viral lifecycle. We further studied the effect of mipomersen, an FDA-approved antisense inhibitor of apoB100, on HCV using in vitro cell-culture competent HCV and determined its impact on viral infectivity with the TCID50 method. RESULTS We found that apoB100 is indispensable for HCV infection. Using the JFH-1 fully infectious cell-culture competent virus in Huh 7 hepatoma cells with TALEN-mediated gene deletion of apoB (APOB KO), we found a significant reduction in HCV RNA and protein levels following infection. Pseudoparticle and replicon models demonstrated that apoB did not play a role in HCV entry or replication. However, the virus produced by APOB KO cells had significantly diminished infectivity as measured by the TCID-50 method compared to wild-type virus. Lipidomic analysis demonstrated that these virions have a fundamentally altered lipidome, with complete depletion of cholesterol esters. We further demonstrate that inhibition of apoB using mipomersen, an FDA-approved anti-sense oligonucleotide, results in a potent anti-HCV effect and significantly reduces the infectivity of the virus. CONCLUSION ApoB is required for the generation of fully infectious HCV virions, and inhibition of apoB with mipomersen blocks HCV. Targeting lipid metabolic pathways to impair viral infectivity represents a novel host targeted strategy to inhibit HCV. PMID:28018102

  18. Phospholipids enhance nucleation but not elongation of apolipoprotein C-II amyloid fibrils.

    Science.gov (United States)

    Ryan, Timothy M; Teoh, Chai L; Griffin, Michael D W; Bailey, Michael F; Schuck, Peter; Howlett, Geoffrey J

    2010-06-25

    Amyloid fibrils and their oligomeric intermediates accumulate in several age-related diseases where their presence is considered to play an active role in disease progression. A common characteristic of amyloid fibril formation is an initial lag phase indicative of a nucleation-elongation mechanism for fibril assembly. We have investigated fibril formation by human apolipoprotein (apo) C-II. ApoC-II readily forms amyloid fibrils in a lipid-dependent manner via an initial nucleation step followed by fibril elongation, breaking, and joining. We used fluorescence techniques and stopped-flow analysis to identify the individual kinetic steps involved in the activation of apoC-II fibril formation by the short-chain phospholipid dihexanoyl phosphatidylcholine (DHPC). Submicellar DHPC activates fibril formation by promoting the rapid formation of a tetrameric species followed by a slow isomerisation that precedes monomer addition and fibril growth. Global fitting of the concentration dependence of apoC-II fibril formation showed that DHPC increased the overall tetramerisation constant from 7.5 x 10(-13) to 1.2 x 10(-6) microM(-3) without significantly affecting the rate of fibril elongation, breaking, or joining. Studies on the effect of DHPC on the free pool of apoC-II monomer and on fibril formation by cross-linked apoC-II dimers further demonstrate that DHPC affects nucleation but not elongation. These studies demonstrate the capacity of small lipid compounds to selectively target individual steps in the amyloid fibril forming pathway.

  19. High serum apolipoprotein E determines hypertriglyceridemic dyslipidemias, coronary disease and apoA-I dysfunctionality.

    Science.gov (United States)

    Onat, Altan; Can, Günay; Ornek, Ender; Ayhan, Erkan; Erginel-Ünaltuna, Nihan; Murat, Sani N

    2013-01-01

    The relevance of serum apolipoprotein E (apoE) levels to two hypertriglyceridemic dyslipidemias has not been clarified. We explored, in a cross-sectional (and short-term prospective) evaluation, the independent relationship of serum apoE to the atherogenic dyslipidemia, hypertriglyceridemia with elevated apoB (HtgB) and to apoA-I dysfunctionality, previously shown in Turkish adults to be independent of apoE genotype. Serum apoE concentrations were measured by immunonephelometry in 1,127 middle-aged adults. In multivariable regression analysis, apoE concentrations showed log-linear associations with apoB and apoA-I levels, waist circumference, independent of C-reactive protein (CRP), homeostatic model assessment (HOMA) index and other confounders. The likelihood of atherogenic dyslipidemia and of HtgB roughly tripled per 1-SD increment in apoE concentrations, additively to apoE genotype, HOMA, apoA-I, CRP concentrations and waist circumference; yet apoA-I, protective against atherogenic dyslipidemia, appeared to promote HtgB, a finding consistent with apoA-I dysfunctionality in this setting. Each 1-SD increment in the apoE level was moreover, associated in both genders with MetS (at OR 1.5), after adjustment for sex, age, apoB, apoA-I and CRP, or for apoE genotypes. Circulating apoE predicted in both genders age-adjusted prevalent and incident coronary heart disease (CHD), independent of apoE genotype and CRP (OR 1.32 [95 % CI 1.11; 1.58]). To conclude, in a general population prone to MetS, elevated apoE concentrations are strongly linked to HtgB and atherogenic dyslipidemia, irrespective of apoE genotype, are associated with MetS and CHD. Excess apoE reflects pro-inflammatory state and likely autoimmune activation.

  20. Apolipoprotein E and Alzheimer disease: Genotype-specific risks by age and sex

    Energy Technology Data Exchange (ETDEWEB)

    Bickeboeller, H. [INSERM, Paris (France)]|[IMSE, Munich (Germany); Babron, M.C.; Clerget-Darpoux, F. [INSERM, Paris (France)] [and others

    1997-02-01

    The distribution of apolipoprotein E (APOE) genotypes as a function of age and sex has been examined in a French population of 417 Alzheimer disease (AD) patients and 1,030 control subjects. When compared to the APOE {epsilon}3 allele, an increased risk associated with the APOE {epsilon}4 allele (odds ratio [OR] [{epsilon}4] = 2.7 with 95% confidence interval [CI] = 2.0-3.6; P < .001) and a protective effect of the APOE {epsilon}2 allele (OR[{epsilon}2] = 0.5 with 95% CI = 0.3-0.98; P = .012) were retrieved. An effect of the {epsilon}4 allele dosage on susceptibility was confirmed (OR[{epsilon}4/{epsilon}4] vs. the {epsilon}3/{epsilon}3 genotype = 11.2 [95% CI = 4.0-31.6]; OR[{epsilon}3/{epsilon}4] vs. the {epsilon}3/{epsilon}3 genotype = 2.2 [95% Cl = 1.5-3.5]). The frequency of the {epsilon}4 allele was lower in male cases than in female cases, but, since a similar difference was found in controls, this does not lead to a difference in OR between sex. ORs for the {epsilon}4 allele versus the {epsilon}3 allele, OR({epsilon}4), were not equal in all age classes: OR({epsilon}4) in the extreme groups with onset at < 60 years or > 79 years were significantly lower than those from the age groups 60-79 years. In {epsilon}3/{epsilon}4 individuals, sex-specific lifetime risk estimates by age 85 years (i.e., sex-specific penetrances by age 85 years) were 0.14 (95% CI 0.04-0.30) for men and 0.17 (95% CI 0.09-0.28) for women. 53 refs., 1 fig., 3 tabs.

  1. Inhibition of apolipoprotein A-I gene expression by obesity-associated endocannabinoids.

    Science.gov (United States)

    Haas, Michael J; Mazza, Angela D; Wong, Norman C W; Mooradian, Arshag D

    2012-04-01

    Obesity is associated with increased serum endocannabinoid (EC) levels and decreased high-density lipoprotein cholesterol (HDLc). Apolipoprotein A-I (apo A-I), the primary protein component of HDL is expressed primarily in the liver and small intestine. To determine whether ECs regulate apo A-I gene expression directly, the effect of the obesity-associated ECs anandamide and 2-arachidonylglycerol on apo A-I gene expression was examined in the hepatocyte cell line HepG2 and the intestinal cell line Caco-2. Apo A-I protein secretion was suppressed nearly 50% by anandamide and 2-arachidonoylglycerol in a dose-dependent manner in both cell lines. Anandamide treatment suppressed both apo A-I mRNA and apo A-I gene promoter activity in both cell lines. Studies using apo A-I promoter deletion constructs indicated that repression of apo A-I promoter activity by anandamide requires a previously identified nuclear receptor binding site designated as site A. Furthermore, anandamide-treatment inhibited protein-DNA complex formation with the site A probe. Exogenous over expression of cannabinoid receptor 1 (CBR1) in HepG2 cells suppressed apo A-I promoter activity, while in Caco-2 cells, exogenous expression of both CBR1 and CBR2 could repress apo A-I promoter activity. The suppressive effect of anandamide on apo A-I promoter activity in Hep G2 cells could be inhibited by CBR1 antagonist AM251 but not by AM630, a selective and potent CBR2 inhibitor. These results indicate that ECs directly suppress apo A-I gene expression in both hepatocytes and intestinal cells, contributing to the decrease in serum HDLc in obese individuals.

  2. Safrole-2',3'-oxide induces atherosclerotic plaque vulnerability in apolipoprotein E-knockout mice.

    Science.gov (United States)

    Su, Le; Zhang, Haiyan; Zhao, Jing; Zhang, Shangli; Zhang, Yun; Zhao, Baoxiang; Miao, Junying

    2013-02-27

    Safrole-2',3'-oxide (SFO) is the major electrophilic metabolite of safrole (4-allyl-1, 2-methylenedioxybenzene), a natural plant constituent found in essential oils of numerous edible herbs and spices and in food containing these herbs, such as pesto sauce, cola beverages and bologna sausages. The effects of SFO in mammalian systems, especially the cardiovascular system, are little known. Disruption of vulnerable atherosclerotic plaques in atherosclerosis, a chronic inflammatory disease, is the main cause of cardiovascular events. In this study, we investigated SFO-induced atherosclerotic plaque vulnerability (possibility of rupture) in apolipoprotein E-knockout (apoE(-/-)) mice. Lipid area in vessel wall reached 59.8% in high dose SFO (SFO-HD) treated group, which is only 31.2% in control group. SFO treatment changed the lesion composition to an unstable phenotype, increased the number of apoptotic cells in plaque and the endothelium in plaques was damaged after SFO treatment. Furthermore, compared with control groups, the plaque endothelium level of p75(NTR) was 3-fold increased and the liver level of p75(NTR) was 17.4-fold increased by SFO-HD. Meanwhile, the serum level of KC (a functional homolog of IL-8 and the main proinflammatory alpha chemokine in mice) in apoE(-/-) mice was up to 357pg/ml in SFO-HD treated group. Thus, SFO contributes to the instability of atherosclerotic plaque in apoE(-/-) mice through activating p75(NTR) and IL-8 and cell apoptosis in plaque.

  3. Apolipoprotein E-epsilon 4 allele and familial risk in Alzheimer's disease.

    Science.gov (United States)

    Li, G; Silverman, J M; Altstiel, L D; Haroutunian, V; Perl, D P; Purohit, D; Birstein, S; Lantz, M; Mohs, R C; Davis, K L

    1996-01-01

    Recent studies have found an association between presence of apolipoprotein E (APOE) epsilon 4 allele and Alzheimer's disease (AD). The present study compared the cumulative risk of primary progressive dementia (PPD) in relatives of AD probands carrying at least one copy of the epsilon 4 allele with the relatives of AD probands not carrying epsilon 4 and with relatives of non-demented controls. Our aim was to determine whether the familial aggregation of PPD in relatives of AD probands is primarily due to those carrying epsilon 4. Seventy-seven neuropathologically diagnosed AD patients were obtained as probands through our Alzheimer's Disease Research Center Brain Bank. AD probands were genotyped for APOE. As a comparison group, 198 non-demented probands were also included. Through family informants, demographic and diagnostic data were collected on 382 first-degree relatives (age > or = 45 years) of AD probands and 848 relatives of the controls. We found that the cumulative risk of PPD in both relatives of AD probands with and without the epsilon 4 allele was significantly higher than that in the relatives of non-demented controls. However, the increased risk in the relatives of AD probands with the epsilon 4 allele was marginally, but not significantly, lower than the risk in the relatives of probands without epsilon 4. A greater likelihood of death by heart diseases over developing PPD in relatives of AD probands with epsilon 4 (3.1-fold increase) was found compared to relatives of probands without epsilon 4 (1.7-fold increase), especially prior to age 70, although the difference was not statistically significant. The increased familial risk for PPD in the relatives of AD probands with the APOE-epsilon 4 allele relative to controls suggests that familial factors in addition to APOE-epsilon 4 are risk factors for AD. Differential censorship from increased mortality of heart diseases may have prevented a higher incidence of PPD among the relatives of probands with

  4. Apolipoprotein C-III Nanodiscs Studied by Site-Specific Tryptophan Fluorescence.

    Science.gov (United States)

    Brisbois, Chase A; Lee, Jennifer C

    2016-09-06

    Apolipoprotein C-III (ApoC-III) is found on high-density lipoproteins (HDLs) and remodels 1,2-dimyristoyl-sn-glycero-3-phosphocholine vesicles into HDL-like particles known as nanodiscs. Using single-Trp-containing ApoC-III mutants, we have studied local side chain environments and interactions in nanodiscs at positions W42, W54, and W65. Using transmission electron microscopy and circular dichroism spectroscopy, nanodiscs were characterized at the ultrastructural and secondary conformational levels, respectively. Nearly identical particles (15 ± 2 nm) were produced from all proteins containing approximately 25 ± 4 proteins per particle with an average helicity of 45-51% per protein. Distinct residue-specific fluorescence properties were observed with W54 residing in the most hydrophobic environment followed by W42 and W65. Interestingly, time-resolved anisotropy measurements revealed that Trp side chain mobility is uncorrelated to the polarity of its surroundings. W54 is the most mobile compared to W65 and W42, which are more immobile in a nanodisc-bound state. On the basis of Trp spectral comparisons of ApoC-III in micellar and vesicle environments, ApoC-III binding within nanodiscs more closely resembles a bilayer-bound state. Despite the nanodiscs being structurally similar, we found marked differences during nanodisc formation by the Trp variants as a function of temperature, with W42 behaving the most like the wild-type protein. Our data suggest that despite the modest mutations of Trp to Phe at two of the three native sites, the interfacial location of W42 is important for lipid binding and nanodisc assembly, which may be biologically meaningful as of the three Trp residues, only W42 is invariant among mammals.

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

    Directory of Open Access Journals (Sweden)

    Masayuki Ozawa

    Full Text Available 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.

  6. Off-target effects of thrombolytic drugs: apolipoprotein A-I proteolysis by alteplase and tenecteplase.

    Science.gov (United States)

    Gomaraschi, Monica; Ossoli, Alice; Vitali, Cecilia; Pozzi, Silvia; Vitali Serdoz, Laura; Pitzorno, Cristina; Sinagra, Gianfranco; Franceschini, Guido; Calabresi, Laura

    2013-02-15

    The administration of thrombolytic drugs is of proven benefit in a variety of clinical conditions requiring acute revascularization, including acute myocardial infarction (AMI), ischemic stroke, pulmonary embolism, and venous thrombosis. Generated plasmin can degrade non-target proteins, including apolipoprotein A-I (apoA-I), the major protein constituent of high-density lipoproteins (HDL). Aim of the present study was to compare the extent of apoA-I proteolytic degradation in AMI patients treated with two thrombolytic drugs, alteplase and the genetically engineered t-PA variant tenecteplase. ApoA-I degradation was evaluated in sera from 38 AMI patients treated with alteplase or tenecteplase. In vitro, apoA-I degradation was tested by incubating control sera or purified HDL with alteplase or tenecteplase at different concentrations (5-100 μg/ml). Treatment with alteplase and tenecteplase results in apoA-I proteolysis; the extent of apoA-I degradation was more pronounced in alteplase-treated patients than in tenecteplase-treated patients. In vitro, the extent of apoA-I proteolysis was higher in alteplase-treated sera than in tenecteplase-treated sera, in the whole drug concentration range. No direct effect of the two thrombolytic agents on apoA-I degradation was observed. In addition to apoA-I, apoA-IV was also degraded by the two thrombolytic agents and again proteolytic degradation was higher with alteplase than tenecteplase. In conclusion, this study indicates that both alteplase and tenecteplase cause plasmin-mediated proteolysis of apoA-I, with alteplase resulting in a greater apoA-I degradation than tenecteplase, potentially causing a transient impairment of HDL atheroprotective functions.

  7. Apolipoprotein A1 gene polymorphisms as risk factors for hypertension and obesity.

    Science.gov (United States)

    Chen, Elizabeth Suchi; Mazzotti, Diego Robles; Furuya, Tatiane Katsue; Cendoroglo, Maysa Seabra; Ramos, Luiz Roberto; Araujo, Lara Quirino; Burbano, Rommel Rodriguez; de Arruda Cardoso Smith, Marília

    2009-12-01

    Several polymorphisms in apolipoprotein A1 (APOA1) gene have been associated with metabolic diseases. Increased transcription efficiency was observed in -75A allele carriers compared to -75G allele homozygotes. +83C allele was associated with higher body mass index and waist-to-hip ratio in type II diabetes subjects. -75G/A and +83C/T polymorphisms were analyzed by RFLP-PCR in 334 individuals from a Brazilian elderly cohort. APOA1 polymorphisms were associated with age-related morbidities, as well as with triglycerides, total cholesterol, HDL, VLDL, LDL, creatinine, urea, albumin, glycated hemoglobin and fasting glucose serum levels. Allele frequencies were 0.102 and 0.21, respectively, for -75A and +83T. -75G allele showed significant association with hypertension (P = 0.001). An association between +83C allele and obesity was observed (P = 0.040) and this allele also showed an association with hypertension in the presence of cardiovascular disease (P = 0.047). Moreover, +83T allele was associated with lower glycated hemoglobin values (P = 0.026). To our knowledge, there is no data associating this polymorphism with glycated hemoglobin. Furthermore, individuals carrying AT haplotype have lower risk for developing hypertension (P = 0.0002), while GT haplotype carriers present decreased risk to develop obesity comparing to GC haplotype (P = 0.025). APOA1 polymorphisms analysis may be a useful tool to identify risk factors for subjects and families and clarify the physiopathological role of these polymorphisms in age-related diseases, such as hypertension and obesity.

  8. CHRNA7 Polymorphisms and Dementia Risk: Interactions with Apolipoprotein ε4 and Cigarette Smoking.

    Science.gov (United States)

    Weng, Pei-Hsuan; Chen, Jen-Hau; Chen, Ta-Fu; Sun, Yu; Wen, Li-Li; Yip, Ping-Keung; Chu, Yi-Min; Chen, Yen-Ching

    2016-06-02

    α7 nicotinic acetylcholine receptor (α7nAChR, encoded by CHRNA7) is involved in dementia pathogenesis through cholinergic neurotransmission, neuroprotection and interactions with amyloid-β. Smoking promotes atherosclerosis and increases dementia risk, but nicotine exerts neuroprotective effect via α7nAChR in preclinical studies. No studies explored the gene-gene, gene-environment interactions between CHRNA7 polymorphism, apolipoprotein E (APOE) ε4 status and smoking on dementia risk. This case-control study recruited 254 late-onset Alzheimer's disease (LOAD) and 115 vascular dementia (VaD) cases (age ≥65) from the neurology clinics of three teaching hospitals in Taiwan during 2007-2010. Controls (N = 435) were recruited from health checkup programs and volunteers during the same period. Nine CHRNA7 haplotype-tagging single nucleotide polymorphisms representative for Taiwanese were genotyped. Among APOE ε4 non-carriers, CHRNA7 rs7179008 variant carriers had significantly decreased LOAD risk after correction for multiple tests (GG + AG vs. AA: adjusted odds ratio = 0.29, 95% confidence interval = 0.13-0.64, P = 0.002). Similar findings were observed for carriers of GT haplotype in CHRNA7 block4. A significant interaction was found between rs7179008, GT haplotype in block4 and APOE ε4 on LOAD risk. rs7179008 variant also reduced the detrimental effect of smoking on LOAD risk. No significant association was found between CHRNA7 and VaD. These findings help to understand dementia pathogenesis.

  9. Functional network endophenotypes unravel the effects of apolipoprotein E epsilon 4 in middle-aged adults.

    Directory of Open Access Journals (Sweden)

    Joseph S Goveas

    Full Text Available Apolipoprotein E-ε4 (APOE-ε4 accentuates memory decline, structural volume loss and cerebral amyloid deposition in cognitively healthy adults. We investigated whether APOE-ε4 carriers will show disruptions in the intrinsic cognitive networks, including the default mode (DMN, executive control (ECN and salience (SN networks, relative to noncarriers in middle-aged healthy adults; and the extent to which episodic-memory performance is related to the altered functional connectivity (Fc in these networks. Resting-state functional connectivity MRI (R-fMRI was used to measure the differences in the DMN, ECN and SN Fc between 20 APOE-ε4 carriers and 26 noncarriers. Multiple linear regression analyses were performed to determine the relationship between episodic-memory performance and Fc differences in the three resting-state networks across all subjects. There were no significant differences in the demographic and neuropsychological characteristics and the gray-matter volumes in the carriers and noncarriers. While mostly diminished DMN and ECN functional connectivities were seen, enhanced connections to the DMN structures were found in the SN in ε4 carriers. Altered DMN and ECN were associated with episodic memory performance. Significant Fc differences in the brain networks implicated in cognition were seen in middle-aged individuals with a genetic risk for AD, in the absence of cognitive decline and gray-matter atrophy. Prospective studies are essential to elucidate the potential of R-fMRI technique as a biomarker for predicting conversion from normal to early AD in healthy APOE-ε4 carriers.

  10. Apolipoprotein E polymorphism influences postprandial retinyl palmitate but not triglyceride concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Boerwinkle, E. (Univ. of Texas Health Science Center, Houston, TX (United States)); Brown, S.; Patsch, W. (Methodist Hospital and Baylor College of Medicine, Houston, TX (United States)); Sharrett, A.R. (National Heart, Lung, and Blood Institute, Bethesda, MD (United States)); Heiss, G. (Univ. of North Carolina, Chapel Hill, NC (United States))

    1994-02-01

    To quantify the effect of the apolipoprotein (apo) E polymorphism on the magnitude of postprandial lipemia, the authors have defined its role in determining the response to a single high-fat meal in a large sample of (N = 474) individuals taking part in the biethnic Atherosclerosis Risk in Communities Study. The profile of postprandial response in plasma was monitored over 8 h by triglyceride, triglyceride-rich lipoprotein (TGRL)-triglyceride, apo B-48/apo B-100 ratio, and retinyl palmitate concentrations, and the apo E polymorphism was determined by DNA amplification and digestion. The frequency of the apo E alleles and their effects on fasting lipid levels in this sample with vitamin A was significantly different among apo E genotypes, with delayed clearance in individuals with an [var epsilon]2 allele, compared with [var epsilon]3/3 and [var epsilon]3/4 individuals. In the sample of 397 Caucasians, average retinyl palmitate response was 1,489 [mu]g/dl in [var epsilon]2/3 individuals, compared with 1,037 [mu]g/dl in [var epsilon]3/3 individuals and 1,108 [mu]g/dl in [var epsilon]3/4 individuals. The apo E polymorphism accounted for 7.1% of the interindividual variation in postprandial retinyl palmitate response, a contribution proportionally greater than its well-known effect on fasting LDL-cholesterol. However, despite this effect on postprandial retinyl palmitate, the profile of postprandial triglyceride response was not significantly different among apo E genotypes. The profile of postprandial response was consistent between the sample of Caucasians and a smaller sample of black subjects. While these data indicate that the removal of remnant particles from circulation is delayed in subjects with the [var epsilon]2/3 genotype, there is no reported evidence that the [var epsilon]2 allele predisposes to coronary artery disease (CAD). 82 refs., 6 figs., 4 tabs.

  11. Oversampling analysis in fractional Fourier domain

    Institute of Scientific and Technical Information of China (English)

    ZHANG Feng; TAO Ran; WANG Yue

    2009-01-01

    Oversampling is widely used in practical applications of digital signal processing. As the fractional Fourier transform has been developed and applied in signal processing fields, it is necessary to consider the oversampling theorem in the fractional Fourier domain. In this paper, the oversampling theorem in the fractional Fourier domain is analyzed. The fractional Fourier spectral relation between the original oversampled sequence and its subsequences is derived first, and then the expression for exact reconstruction of the missing samples in terms of the subsequences is obtained. Moreover, by taking a chirp signal as an example, it is shown that, reconstruction of the missing samples in the oversampled signal Is suitable in the fractional Fourier domain for the signal whose time-frequency distribution has the minimum support in the fractional Fourier domain.

  12. Human apolipoprotein E4 modulates the expression of Pin1, Sirtuin 1, and Presenilin 1 in brain regions of targeted replacement apoE mice.

    Science.gov (United States)

    Lattanzio, F; Carboni, L; Carretta, D; Rimondini, R; Candeletti, S; Romualdi, P

    2014-01-01

    The apolipoprotein E4 (apoE4) allele is consistently associated with increased risk for Alzheimer's disease (AD). We investigated the molecular mechanism of this susceptibility by analyzing the levels of genes involved in AD pathogenesis in transgenic mice expressing human apoE3 or apoE4 isoforms. mRNA and protein levels of Pin1, Sirtuin 1 (Sirt1), Presenilin 1 (PS1), and pro-Brain-derived Neurotrophic Factor (BDNF) were analyzed in brain regions affected by neuropathological changes in AD. Pin1 mRNA was significantly higher in the hippocampus of apoE4 mice than in apoE3 controls, whereas lower expression was detected in the entorhinal and parietal cortices. Reduced Pin1 levels may increase neurofibrillary degeneration and amyloidogenic processes, while compensatory mechanisms may take place in the hippocampus to balance spatial memory deficits. Sirt1 levels were significantly reduced in the frontal cortex of apoE4 mice. Sirt1 reduction may hinder its protective role against the formation of plaques and tangles and diminish its anti-inflammatory actions. Sirt1 decrease may also play a role in apoE4-associated memory impairments. Moreover, in apoE4 mice PS1 mRNA levels were lower in the frontal cortex. Lower PS1 expression may hamper γ-secretase function, thus affecting amyloid precursor protein processing. Pro-BDNF mRNA levels did not differ between apoE3 and apoE4 mice in any region analyzed. This study showed dysregulated expression of Pin1, Sirt1, and PS1 genes in different cerebral areas of apoE4 mice, suggesting that these changes may play a role in the mechanism of AD vulnerability.

  13. Stimulation of Hepatic Apolipoprotein A-I Production by Novel Thieno-Triazolodiazepines: Roles of the Classical Benzodiazepine Receptor, PAF Receptor, and Bromodomain Binding.

    Science.gov (United States)

    Kempen, Herman J; Bellus, Daniel; Fedorov, Oleg; Nicklisch, Silke; Filippakopoulos, Panagis; Picaud, Sarah; Knapp, Stefan

    2013-01-01

    Expression and secretion of apolipoprotein A-I (apoA-I) by cultured liver cells can be markedly stimulated by triazolodiazepines (TZDs). It has been shown previously that the thieno-TZD Ro 11-1464 increases plasma levels of apoA-I and in vivomacrophage reverse cholesterol transport in mice. However, these effects were only seen at high doses, at which the compound could act on central benzodiazepine (BZD) receptors or platelet activating factor (PAF) receptors, interfering with its potential utility. In this work, we describe 2 new thieno-TZDs MDCO-3770 and MDCO-3783, both derived from Ro 11-1464. These compounds display the same high efficacy on apoA-I production, metabolic stability, and lack of cytotoxicity in cultured hepatocytes as Ro 11-1464, but they do not bind to the central BZD receptor and PAF receptor. The quinazoline RVX-208 was less efficacious in stimulating apoA-I production and displayed signs of cytotoxicity. Certain TZDs stimulating apoA-I production are now known to be inhibitors of bromodomain (BRD) extra-terminal (BET) proteins BRDT, BRD2, BRD3, and BRD4, and this inhibition was inferred as a main molecular mechanism for their effect on apoA-I expression. We show here that the thieno-TZD (+)-JQ1, a potent BET inhibitor, strongly stimulated apoA-I production in Hep-G2 cells, but that its enantiomer (-)-JQ1, which has no BET inhibitor activity, also showed considerable effect on apoA-I production. MDCO-3770 and MDCO-3783 also inhibited BRD3 and BRD4 in vitro, with potency somewhat below that of (+)-JQ1. We conclude that the effect of thieno-TZDs on apoA-I expression is not due to inhibition of the BZD or PAF receptors and is not completely explained by transcriptional repression by BET proteins.

  14. Conversion of Dielectric Data from the Time Domain to the Frequency Domain

    Directory of Open Access Journals (Sweden)

    Vladimir Durman

    2005-01-01

    Full Text Available Polarisation and conduction processes in dielectric systems can be identified by the time domain or the frequency domain measurements. If the systems is a linear one, the results of the time domain measurements can be transformed into the frequency domain, and vice versa. Commonly, the time domain data of the absorption conductivity are transformed into the frequency domain data of the dielectric susceptibility. In practice, the relaxation are mainly evaluated by the frequency domain data. In the time domain, the absorption current measurement were prefered up to now. Recent methods are based on the recovery voltage measurements. In this paper a new method of the recovery data conversion from the time the frequency domain is proposed. The method is based on the analysis of the recovery voltage transient based on the Maxwell equation for the current density in a dielectric. Unlike the previous published solutions, the Laplace fransform was used to derive a formula suitable for practical purposes. the proposed procedure allows also calculating of the insulation resistance and separating the polarisation and conduction losses.

  15. Domain Walls on Singularities

    CERN Document Server

    Halyo, Edi

    2009-01-01

    We describe domain walls that live on $A_2$ and $A_3$ singularities. The walls are BPS if the singularity is resolved and non--BPS if it is deformed and fibered. We show that these domain walls may interpolate between vacua that support monopoles and/or vortices.

  16. A Domain Analysis Bibliography

    Science.gov (United States)

    1990-06-01

    Bauhaus , a prototype CASE workstation for D-SAPS development. [ARAN88A] Guillermo F. Arango. Domain Engineering for Software Reuse. PhD thesis...34 VITA90B: Domain Analysis within the ISEC Rapid Center 48 CMU/SEI-90-SR-3 Appendix III Alphabetical by Organization/Project BAUHAUS * ALLE87A

  17. Identification of two apolipoprotein variants, A-I Karatsu (Tyr 100-->His) and A-I Kurume (His 162-->Gln).

    Science.gov (United States)

    Moriyama, K; Sasaki, J; Matsunaga, A; Takada, Y; Kagimoto, M; Arakawa, K

    1996-02-01

    We identified two apolipoprotein (apo) A-I variants, using isoelectric focusing gel electrophoresis: apo A-I Karatsu, which had a relative charge of +1 compared to normal apo A-I4, and apo A-I Kurume, which had a relative charge of -1. Direct sequence analysis of the PCR-amplified DNA from the proband of apo A-I Karatsu revealed a single substitution of tyrosine (TAC) for histidine (CAC) at position 100. Sequence analysis of apo A-I Kurume revealed a single substitution of histidine (CAT) for glutamine (CAG) at position 162. Probands of these two mutants and limited family study showed no accelerated atherosclerosis.

  18. Effect of apolipoprotein E and butyrylcholinesterase genotypes on cognitive response to cholinesterase inhibitor treatment at different stages of Alzheimer's disease.

    Science.gov (United States)

    Patterson, C E; Todd, S A; Passmore, A P

    2011-12-01

    Factors that influence response to drug treatment are of increasing importance. We report an analysis of genetic factors affecting response to cholinesterase inhibitor therapy in 165 subjects with Alzheimer's disease (AD). The presence of apolipoprotein E ε4 (APOE ε4) allele was associated with early and late cognitive response to cholinesterase inhibitor treatment in mild AD (Mini-Mental State Examination (MMSE) ≥21) (P<0.01). In moderate-to-severe AD (MMSE ≤15), presence of the BCHE-K variant was associated with late response to cholinesterase inhibitor treatment (P=0.02). Testing for APOE and BCHE genotypes may be useful in therapeutic decision making.

  19. Relationship of plasma apolipoprotein M with proprotein convertase subtilisin-kexin type 9 levels in non-diabetic subjects

    DEFF Research Database (Denmark)

    Kappelle, Paul J W H; Lambert, Gilles; Dahlbäck, Björn;

    2011-01-01

    PURPOSE: Apolipoprotein M (apoM) retards atherosclerosis development in murine models, and may be regulated by pathways involved in LDL metabolism. Proprotein convertase subtilisin-kexin type 9 (PCSK9) plays a key role in LDL receptor processing. We determined the extent to which plasma apo......M is related to PCSK9 levels in subjects with varying degrees of obesity. METHODS: We sought correlations between plasma apoM and PCSK9, measured using recently developed ELISAs, in 79 non-diabetic subjects. RESULTS: ApoM and PCSK9 levels were both correlated positively with total cholesterol, non-HDL...... cholesterol, LDL cholesterol and apoB (P

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

    Science.gov (United States)

    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.

  1. XbaⅠpolymorphisms of apolipoprotein B gene:Another risk factor of gallstone formation after radical gastrectomy

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    AIM:To prospectively investigate the association between the XbaⅠpolymorphisms of apolipoprotein B (APOB)gene and gallstone formation following gastrectomy.METHODS:The study was conducted between January 2005 and December 2006.A total of 186 gastric cancer patients who had undergone radical gastrectomy were grouped according to XbaⅠpolymorphisms of APOB gene(X+X-group,n=24 and X-X-group,n =162)and compared.The XbaⅠpolymorphisms of APOB gene were detected by polymerase chain reaction-restriction fragment len...

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

    Directory of Open Access Journals (Sweden)

    Jessica P. Otis

    2015-03-01

    Full Text Available 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

  3. A mixed finite element domain decomposition method for nearly elastic wave equations in the frequency domain

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Xiaobing [Univ. of Tennessee, Knoxville, TN (United States)

    1996-12-31

    A non-overlapping domain decomposition iterative method is proposed and analyzed for mixed finite element methods for a sequence of noncoercive elliptic systems with radiation boundary conditions. These differential systems describe the motion of a nearly elastic solid in the frequency domain. The convergence of the iterative procedure is demonstrated and the rate of convergence is derived for the case when the domain is decomposed into subdomains in which each subdomain consists of an individual element associated with the mixed finite elements. The hybridization of mixed finite element methods plays a important role in the construction of the discrete procedure.

  4. Hemoglobin derivatives

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003371.htm Hemoglobin derivatives To use the sharing features on this page, please enable JavaScript. Hemoglobin derivatives are altered forms of hemoglobin . Hemoglobin is ...

  5. Single point mutations in the helicase domain of the NS3 protein enhance dengue virus replicative capacity in human monocyte-derived dendritic cells and circumvent the type I interferon response.

    Science.gov (United States)

    Silveira, G F; Strottmann, D M; de Borba, L; Mansur, D S; Zanchin, N I T; Bordignon, J; dos Santos, C N Duarte

    2016-01-01

    Dengue is the most prevalent arboviral disease worldwide. The outcome of the infection is determined by the interplay of viral and host factors. In the present study, we evaluated the cellular response of human monocyte-derived DCs (mdDCs) infected with recombinant dengue virus type 1 (DV1) strains carrying a single point mutation in the NS3hel protein (L435S or L480S). Both mutated viruses infect and replicate more efficiently and produce more viral progeny in infected mdDCs compared with the parental, non-mutated virus (vBACDV1). Additionally, global gene expression analysis using cDNA microarrays revealed that the mutated DVs induce the up-regulation of the interferon (IFN) signalling and pattern recognition receptor (PRR) canonical pathways in mdDCs. Pronounced production of type I IFN were detected specifically in mdDCs infected with DV1-NS3hel-mutated virus compared with mdDCs infected with the parental virus. In addition, we showed that the type I IFN produced by mdDCs is able to reduce DV1 infection rates, suggesting that cytokine function is effective but not sufficient to mediate viral clearance of DV1-NS3hel-mutated strains. Our results demonstrate that single point mutations in subdomain 2 have important implications for adenosine triphosphatase (ATPase) activity of DV1-NS3hel. Although a direct functional connection between the increased ATPase activity and viral replication still requires further studies, these mutations speed up viral RNA replication and are sufficient to enhance viral replicative capacity in human primary cell infection and circumvent type I IFN activity. This information may have particular relevance for attenuated vaccine protocols designed for DV.

  6. Stable Probability Distributions and their Domains of Attraction

    NARCIS (Netherlands)

    J.L. Geluk (Jaap); L.F.M. de Haan (Laurens)

    1997-01-01

    textabstractThe theory of stable probability distributions and their domains of attraction is derived in a direct way (avoiding the usual route via infinitely divisible distributions) using Fourier transforms. Regularly varying functions play an important role in the exposition.

  7. The Peculiar Evolution of Apolipoprotein(a) in Human and Rhesus Macaque

    OpenAIRE

    Pesole, G.; A. Gerardi; di-Jeso, F.; Saccone, C.

    1994-01-01

    Apo(a) is a low density lipoprotein homologous to plasminogen and has been shown to be involved in coronary atheroschlerosis. In the present paper we will try to analyze the interesting evolutionary pattern of Apo(a). The plasminogen gene contains 5 cysteine-rich sequences, called kringles, followed by a protease domain. Apo(a), probably arisen by duplication of an ancestral plasminogen gene, contains many tandemly repeated copies of a sequence domain similar to the fourth kringle of plasmino...

  8. On Automatic Modeling and Use of Domain-specific Ontologies

    DEFF Research Database (Denmark)

    Andreasen, Troels; Knappe, Rasmus; Bulskov, Henrik

    2005-01-01

    In this paper, we firstly introduce an approach to the modeling of a domain-specific ontology for use in connection with a given document collection. Secondly, we present a methodology for deriving conceptual similarity from the domain-specific ontology. Adopted for ontology representation is a s...

  9. The Existence Problem for Steiner Networks in Strictly Convex Domains

    Science.gov (United States)

    Freire, Alexandre

    2011-05-01

    We consider the existence problem for `Steiner networks' (trivalent graphs with 2 π/3 angles at each junction) in strictly convex domains, with `Neumann' boundary conditions. For each of the three possible combinatorial possibilities, sufficient conditions on the domain are derived for existence. In addition, in each case explicit examples of nonexistence are given.

  10. A Parametric Abstract Domain for Lattice-Valued Regular Expressions

    DEFF Research Database (Denmark)

    Midtgaard, Jan; Nielson, Flemming; Nielson, Hanne Riis

    2016-01-01

    We present a lattice-valued generalization of regular expressions as an abstract domain for static analysis. The parametric abstract domain rests on a generalization of Brzozowski derivatives and works for both finite and infinite lattices. We develop both a co-inductive, simulation algorithm...

  11. An investigation of human apolipoproteins B and E polymorphisms in two African populations from Ethiopia and Benin.

    Science.gov (United States)

    Corbo, R.M.; Scacchi, R.; Rickards, O.; Martinez-Labarga, C.; De Stefano, G.F.

    1999-01-01

    Three polymorphisms (XbaI, EcoRI, and Ins/Del) of the apolipoprotein B (APOB) gene and the polymorphism of apolipoprotein E (APOE) were investigated in two population samples of Amhara and Oromo origin from Ethiopia, and in two population samples of Bariba and Berba origin from Benin. No heterogeneity was observed within each major group. The cumulated frequencies of the APOB X+, R+, and D alleles for the Ethiopia and the Benin groups were 0.268 and 0.133, 0.958 and 0.818, 0.206 and 0.223, respectively. Regarding APOE, the cumulated allele frequencies of Ethiopia and Benin were 0.031 and 0.103 for epsilon*2 allele, 0.811 and 0.742 for epsilon*3, and 0.143 and 0.155 for epsilon*4, respectively. APOE typing performed at the protein level only in the Ethiopians revealed a variant allele, epsilon*5, found at the polymorphic level both in the Amhara and in the Oromo (cumulated frequency: 0.015). A tentative explanation for the higher frequencies of epsilon*4 and epsilon*5 alleles was sought in relation to the lifestyle and ethnicity of the two populations. Am. J. Hum. Biol. 11:297-304, 1999. Copyright 1999 Wiley-Liss, Inc.

  12. Human ApoD, an apolipoprotein up-regulated in neurodegenerative diseases, extends lifespan and increases stress resistance in Drosophila.

    Science.gov (United States)

    Muffat, Julien; Walker, David W; Benzer, Seymour

    2008-05-13

    Apolipoprotein D (ApoD) expression increases in several neurological disorders and in spinal cord injury. We provide a report of a physiological role for human ApoD (hApoD): Flies overexpressing hApoD are long-lived and protected against stress conditions associated with aging and neurodegeneration, including hyperoxia, dietary paraquat, and heat stress. We show that the fly ortholog, Glial Lazarillo, is strongly up-regulated in response to these extrinsic stresses and also can protect in vitro-cultured cells in situations modeling Alzheimer's disease (AD) and Parkinson's disease (PD). In adult flies, hApoD overexpression reduces age-associated lipid peroxide accumulation, suggesting a proximal mechanism of action. Similar data obtained in the mouse [Ganfornina, M.D., et al., (2008) Apolipoprotein D is involved in the mechanisms regulating protection from oxidative stress. Aging Cell 10.1111/j.1474-9726.2008.00395.] as well as in plants (Charron et al., personal communication) suggest that ApoD and its orthologs play an evolutionarily conserved role in response to stress, possibly managing or preventing lipid peroxidation.

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

    Science.gov (United States)

    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 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.

  14. Reduction of Risk Factor Coagulation Oxidative Apolipoprotein and Development of Atherosclerosis by Apple Cider Vinegar in Hypercholesterolemic Rabbits

    Directory of Open Access Journals (Sweden)

    Mahbubeh Setorki

    2009-01-01

    Full Text Available Introduction: Apple cider vinegar is an antioxidant compound and it has many medical uses. In this research we have investigated effects of apple cider vinegar on some risk factors of atherosclerosis and on the development of atherosclerosis in hypercholesterolemic rabbit. Methods: Thirty two male New Zealand rabbits were randomly divided into four groups: normal diet group high cholesterol diet group (%1cholesterol %1 cholesterol with 5ml apple cider vinegar group and %1 cholesterol with 10ml apple cider vinegar group .The malondialdehyde (MDA oxidized-LDL (oxLDL fibrinogen factor VII apolipoprotein A (ApoA and apolipoprotein B (ApoB were measured before the experiment and at the end period (2month. At the end of study using Chekanov method fatty streak formation in aorta artery was determined in all groups. Results: Using both doses of apple cider vinegar significantly decreased fibrinogen oxLDL MDA ApoB ApoB/ApoA VIIlevels in comparison with hypercholesterolemic diet (P0.05. Also consumption of apple cider vinegar induced significant decrease in atherosclerotic lesions in aorta artery compared to the hypercholesterolemic diet. Conclusion: This study suggests that apple cider vinegar (as an antioxidant might have some protective effects on biochemical risk factors of atherosclerosis.

  15. Syntactic-semantic treebank for domain ontology creation

    Directory of Open Access Journals (Sweden)

    Petya Osenova

    2015-11-01

    Full Text Available Syntactic-semantic treebank for domain ontology creation This paper focuses on the creation of a domain treebank for the purposes of compiling a domain ontology. The domain treebank is viewed as a suitable resource for extracting of semantic relations from syntactic structures. First, the steps for ontology building are considered. Then, the processing over glossaries and standards is described with regard to their syntactic annotation. The utility of deriving semantic knowledge from the Treebank is also illustrated via the basic phrases. The idea is that the domain knowledge is represented in the domain data, but via treebanking more linguistic patterns can be extracted, which to be mapped to concepts and relations in a domain ontology.

  16. Localization of Laplacian eigenfunctions in circular, spherical and elliptical domains

    CERN Document Server

    Nguyen, Binh-Thanh

    2012-01-01

    We consider Laplacian eigenfunctions in circular, spherical and elliptical domains in order to discuss three kinds of high-frequency localization: whispering gallery modes, bouncing ball modes, and focusing modes. Although the existence of these modes was known for a class of convex domains, the separation of variables for above domains helps to better understand the "mechanism" of localization, i.e. how an eigenfunction is getting distributed in a small region of the domain, and decays rapidly outside this region. Using the properties of Bessel and Mathieu functions, we derive the inequalities which imply and clearly illustrate localization. Moreover, we provide an example of a non-convex domain (an elliptical annulus) for which the high-frequency localized modes are still present. At the same time, we show that there is no localization in most of rectangle-like domains. This observation leads us to formulating an open problem of localization in polygonal domains and, more generally, in piecewise smooth conv...

  17. Conserved Domain Database (CDD)

    Data.gov (United States)

    U.S. Department of Health & Human Services — CDD is a protein annotation resource that consists of a collection of well-annotated multiple sequence alignment models for ancient domains and full-length proteins.

  18. Alanyl-glutamine attenuates 5-fluorouracil-induced intestinal mucositis in apolipoprotein E-deficient mice

    Directory of Open Access Journals (Sweden)

    C.V. Araújo

    2015-06-01

    Full Text Available Apolipoprotein E (APOE=gene, apoE=protein is a known factor regulating the inflammatory response that may have regenerative effects during tissue recovery from injury. We investigated whether apoE deficiency reduces the healing effect of alanyl-glutamine (Ala-Gln treatment, a recognized gut-trophic nutrient, during tissue recovery after 5-FU-induced intestinal mucositis. APOE-knockout (APOE-/- and wild-type (APOE+/+ C57BL6J male and female mice (N=86 were given either Ala-Gln (100 mM or phosphate buffered saline (PBS by gavage 3 days before and 5 days after a 5-fluorouracil (5-FU challenge (450 mg/kg, via intraperitoneal injection. Mouse body weight was monitored daily. The 5-FU cytotoxic effect was evaluated by leukometry. Intestinal villus height, villus/crypt ratio, and villin expression were monitored to assess recovery of the intestinal absorptive surface area. Crypt length, mitotic, apoptotic, and necrotic crypt indexes, and quantitative real-time PCR for insulin-like growth factor-1 (IGF-1 and B-cell lymphoma 2 (Bcl-2 intestinal mRNA transcripts were used to evaluate intestinal epithelial cell turnover. 5-FU challenge caused significant weight loss and leukopenia (P<0.001 in both mouse strains, which was not improved by Ala-Gln. Villus blunting, crypt hyperplasia, and reduced villus/crypt ratio (P<0.05 were found in all 5-FU-challenged mice but not in PBS controls. Ala-Gln improved villus/crypt ratio, crypt length and mitotic index in all challenged mice, compared with PBS controls. Ala-Gln improved villus height only in APOE-/- mice. Crypt cell apoptosis and necrotic scores were increased in all mice challenged by 5-FU, compared with untreated controls. Those scores were significantly lower in Ala-Gln-treated APOE+/+ mice than in controls. Bcl-2 and IGF-1 mRNA transcripts were reduced only in the APOE-/--challenged mice. Altogether our findings suggest APOE-independent Ala-Gln regenerative effects after 5-FU challenge.

  19. Alanyl-glutamine attenuates 5-fluorouracil-induced intestinal mucositis in apolipoprotein E-deficient mice

    Energy Technology Data Exchange (ETDEWEB)

    Araújo, C.V. [Laboratório da Biologia da Cicatrização, Ontogenia e Nutrição de Tecidos, INCT - Instituto de Biomedicina do Semiárido Brasileiro, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, CE (Brazil); Lazzarotto, C.R. [Laboratório de Biologia Molecular e do Desenvolvimento, Universidade de Fortaleza, Fortaleza, CE (Brazil); Aquino, C.C.; Figueiredo, I.L.; Costa, T.B.; Oliveira Alves, L.A. de [Laboratório da Biologia da Cicatrização, Ontogenia e Nutrição de Tecidos, INCT - Instituto de Biomedicina do Semiárido Brasileiro, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, CE (Brazil); Ribeiro, R.A. [Laboratório da Inflamação e Câncer, INCT - Instituto de Biomedicina do Semiárido Brasileiro, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, CE (Brazil); Bertolini, L.R. [Laboratório de Biologia Molecular e do Desenvolvimento, Universidade de Fortaleza, Fortaleza, CE (Brazil); Lima, A.A.M. [Laboratório de Doenças Infecciosas, INCT - Instituto de Biomedicina do Semiárido Brasileiro, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, CE (Brazil); Brito, G.A.C. [Laboratório da Inflamação e Câncer, INCT - Instituto de Biomedicina do Semiárido Brasileiro, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, CE (Brazil); Oriá, R.B. [Laboratório da Biologia da Cicatrização, Ontogenia e Nutrição de Tecidos, INCT - Instituto de Biomedicina do Semiárido Brasileiro, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, CE (Brazil)

    2015-04-28

    Apolipoprotein E (APOE=gene, apoE=protein) is a known factor regulating the inflammatory response that may have regenerative effects during tissue recovery from injury. We investigated whether apoE deficiency reduces the healing effect of alanyl-glutamine (Ala-Gln) treatment, a recognized gut-trophic nutrient, during tissue recovery after 5-FU-induced intestinal mucositis. APOE-knockout (APOE{sup -/-}) and wild-type (APOE{sup +/+}) C57BL6J male and female mice (N=86) were given either Ala-Gln (100 mM) or phosphate buffered saline (PBS) by gavage 3 days before and 5 days after a 5-fluorouracil (5-FU) challenge (450 mg/kg, via intraperitoneal injection). Mouse body weight was monitored daily. The 5-FU cytotoxic effect was evaluated by leukometry. Intestinal villus height, villus/crypt ratio, and villin expression were monitored to assess recovery of the intestinal absorptive surface area. Crypt length, mitotic, apoptotic, and necrotic crypt indexes, and quantitative real-time PCR for insulin-like growth factor-1 (IGF-1) and B-cell lymphoma 2 (Bcl-2) intestinal mRNA transcripts were used to evaluate intestinal epithelial cell turnover. 5-FU challenge caused significant weight loss and leukopenia (P<0.001) in both mouse strains, which was not improved by Ala-Gln. Villus blunting, crypt hyperplasia, and reduced villus/crypt ratio (P<0.05) were found in all 5-FU-challenged mice but not in PBS controls. Ala-Gln improved villus/crypt ratio, crypt length and mitotic index in all challenged mice, compared with PBS controls. Ala-Gln improved villus height only in APOE{sup -/-} mice. Crypt cell apoptosis and necrotic scores were increased in all mice challenged by 5-FU, compared with untreated controls. Those scores were significantly lower in Ala-Gln-treated APOE{sup +/+} mice than in controls. Bcl-2 and IGF-1 mRNA transcripts were reduced only in the APOE{sup -/-}-challenged mice. Altogether our findings suggest APOE-independent Ala-Gln regenerative effects after 5-FU

  20. 18F-fluorodeoxyglucose positron emission tomography, aging, and apolipoprotein E genotype in cognitively normal persons.

    Science.gov (United States)

    Knopman, David S; Jack, Clifford R; Wiste, Heather J; Lundt, Emily S; Weigand, Stephen D; Vemuri, Prashanthi; Lowe, Val J; Kantarci, Kejal; Gunter, Jeffrey L; Senjem, Matthew L; Mielke, Michelle M; Roberts, Rosebud O; Boeve, Bradley F; Petersen, Ronald C

    2014-09-01

    Our objective was to examine associations between glucose metabolism, as measured by (18)F-fluorodeoxyglucose positron emission tomography (FDG PET), and age and to evaluate the impact of carriage of an apolipoprotein E (APOE) ε4 allele on glucose metabolism and on the associations between glucose metabolism and age. We studied 806 cognitively normal (CN) and 70 amyloid-imaging-positive cognitively impaired participants (35 with mild cognitive impairment and 35 with Alzheimer's disease [AD] dementia) from the Mayo Clinic Study of Aging, Mayo Alzheimer's Disease Research Center and an ancillary study who had undergone structural MRI, FDG PET, and (11)C-Pittsburgh compound B (PiB) PET. Using partial volume corrected and uncorrected FDG PET glucose uptake ratios, we evaluated associations of regional FDG ratios with age and carriage of an APOE ε4 allele in CN participants between the ages of 30 and 95 years, and compared those findings with the cognitively impaired participants. In region-of-interest (ROI) analyses, we found modest but statistically significant declines in FDG ratio in most cortical and subcortical regions as a function of age. We also found a main effect of APOE ε4 genotype on FDG ratio, with greater uptake in ε4 noncarriers compared with carriers but only in the posterior cingulate and/or precuneus, lateral parietal, and AD-signature meta-ROI. The latter consisted of voxels from posterior cingulate and/or precuneus, lateral parietal, and inferior temporal. In age- and sex-matched CN participants the magnitude of the difference in partial volume corrected FDG ratio in the AD-signature meta-ROI for APOE ε4 carriers compared with noncarriers was about 4 times smaller than the magnitude of the difference between age- and sex-matched elderly APOE ε4 carrier CN compared with AD dementia participants. In an analysis in participants older than 70 years (31.3% of whom had elevated PiB), there was no interaction between PiB status and APOE ε4 genotype

  1. Sex differences in apolipoprotein A1 and nevirapine-induced toxicity

    Directory of Open Access Journals (Sweden)

    Aline Marinho

    2014-11-01

    Full Text Available Nevirapine (NVP is associated with severe liver and skin toxicity through sulfotransferase (SULT bioactivation of the phase I metabolite 12-hydroxy-NVP [1–3]. The female sex, a well-known risk factor for NVP-induced toxicity, is associated with higher SULT expression (4 and lower plasma levels of 12-hydroxy-NVP [3]. Interestingly, apolipoprotein A1 (ApoA1 increases SULT2B1 activity and ApoA1 synthesis is increased by NVP [5, 6]. Herein, we explore the effect of ApoA1 levels on NVP metabolism and liver function. The study protocol was firstly approved by the hospitals’ Ethics Committees. All included individuals were HIV-infected patients treated with NVP for at least one month. The plasma concentrations of NVP and its phase I metabolites were quantified by HPLC [7]. ApoA1 levels were assessed by an immunoturbidimetric assay. Forty-nine HIV-infected patients on NVP were included (53% men, 59% Caucasian. NVP plasma levels were correlated with HDL-cholesterol (Spearman r=0.2631; p=0.0441 and ApoA1 (Spearman r=0.3907; p=0.0115. Women had higher ApoA1 levels than men (Student's t Test; p=0.0051. In both sexes, 12-hydroxy-NVP levels were negatively correlated with ApoA1 (male: Spearman r=−0.3810; p=0.0499 female: Spearman r=−0.5944; p=0.0415. In men, ApoA1 was positively correlated with aspartate aminotransferase (AST, Spearman r=0.5507; p=0.0413, while in women ApoA1 was associated (Spearman r=0.6408; p=0.0056 with alanine aminotransferase (ALT. These results show sex differences in NVP-induced ApoA1 synthesis. The higher ApoA1 levels in women might stabilize SULT2B1 [6]. This would explain the lower levels of 12-hydroxy-NVP [3] and the higher hepatotoxicity found in women, due to increased sulfonation of this metabolite. These data support a role for ApoA1 in the sex dimorphic mechanism leading to NVP-induced toxicity.

  2. Synthesis of apolipoprotein B lipoparticles to deliver hydrophobic/amphiphilic materials.

    Science.gov (United States)

    Chu, Hsueh-Liang; Cheng, Tsai-Mu; Chen, Hung-Wei; Chou, Fu-Hsuan; Chang, Yu-Chuan; Lin, Hsin-Yu; Liu, Shih-Yi; Liang, Yu-Chuan; Hsu, Ming-Hua; Wu, Dian-Shyeu; Li, Hsing-Yuan; Ho, Li-Ping; Wu, Ping-Ching; Chen, Fu-Rong; Chen, Gong-Shen; Shieh, Dar-Bin; Chang, Chia-Seng; Su, Chia-Hao; Yao, Zemin; Chang, Chia-Ching

    2013-08-14

    To develop a drug delivery system (DDS), it is critical to address challenging tasks such as the delivery of hydrophobic and amphiphilic compounds, cell uptake, and the metabolic fate of the drug delivery carrier. Low-density lipoprotein (LDL) has been acknowledged as the human serum transporter of natively abundant lipoparticles such as cholesterol, triacylglycerides, and lipids. Apolipoprotein B (apo B) is the only protein contained in LDL, and possesses a binding moiety for the LDL receptor that can be internalized and degraded naturally by the cell. Therefore, synthetic/reconstituting apoB lipoparticle (rABL) could be an excellent delivery carrier for hydrophobic or amphiphilic materials. Here, we synthesized rABL in vitro, using full-length apoB through a five-step solvent exchange method, and addressed its potential as a DDS. Our rABL exhibited good biocompatibility when evaluated with cytotoxicity and cell metabolic response assays, and was stable during storage in phosphate-buffered saline at 4 °C for several months. Furthermore, hydrophobic superparamagnetic iron oxide nanoparticles (SPIONPs) and the anticancer drug M4N (tetra-O-methyl nordihydroguaiaretic acid), used as an imaging enhancer and lipophilic drug model, respectively, were incorporated into the rABL, leading to the formation of SPIONPs- and M4N- containing rABL (SPIO@rABL and M4N@rABL, respectively). Fourier transform infrared spectroscopy suggested that rABL has a similar composition to that of LDL, and successfully incorporated SPIONPs or M4N. SPIO@rABL presented significant hepatic contrast enhancement in T2-weighted magnetic resonance imaging in BALB/c mice, suggesting its potential application as a medical imaging contrast agent. M4N@rABL could reduce the viability of the cancer cell line A549. Interestingly, we developed solution-phase high-resolution transmission electron microscopy to observe both LDL and SPIO@rABL in the liquid state. In summary, our LDL-based DDS, rABL, has

  3. High- and low-temperature unfolding of human high-density apolipoprotein A-2.

    Science.gov (United States)

    Gursky, O; Atkinson, D

    1996-09-01

    Human plasma apolipoprotein A-2 (apoA-2) is the second major protein of the high-density lipoproteins that mediate the transport and metabolism of cholesterol. Using CD spectroscopy and differential scanning calorimetry, we demonstrate that the structure of lipid-free apoA-2 in neutral low-salt solutions is most stable at approximately 25 degrees C and unfolds reversibly both upon heating and cooling from 25 degrees C. High-temperature unfolding of apoA-2, monitored by far-UV CD, extends from 25-85 degrees C with midpoint Th = 56 +/- 2 degrees C and vant Hoff's enthalpy delta H(Th) = 17 +/- 2 kcal/mol that is substantially lower than the expected enthalpy of melting of the alpha-helical structure. This suggests low-cooperativity apoA-2 unfolding. The apparent free energy of apoA-2 stabilization inferred from the CD analysis of the thermal unfolding, delta G(app)(25 degrees) = 0.82 +/- 0.15 kcal/mol, agrees with the value determined from chemical denaturation. Enhanced low-temperature stability of apoA-2 observed upon increase in Na2HPO4 concentration from 0.3 mM to 50 mM or addition of 10% glycerol may be linked to reduced water activity. The close proximity of the heat and cold unfolding transitions, that is consistent with low delta G(app)(25 degrees), indicates that lipid-free apoA-2 has a substantial hydrophobic core but is only marginally stable under near-physiological solvent conditions. This suggests that in vivo apoA-2 transfer is unlikely to proceed via the lipid-free state. Low delta H(Th) and low apparent delta Cp approximately 0.52 kcal/mol.K inferred from the far-UV CD analysis of apoA-2 unfolding, and absence of tertiary packing interactions involving Tyr groups suggested by near-UV CD, are consistent with a molten globular-like state of lipid-free apoA-2.

  4. Blocking TLR2 activity diminishes and stabilizes advanced atherosclerotic lesions in apolipoprotein E-deficient mice

    Institute of Scientific and Technical Information of China (English)

    Xiao-xing WANG; Xiao-xi LV; Jia-ping WANG; Hui-min YAN; Zi-yan WANG; Han-zhi LIU; Xiao-ming FU

    2013-01-01

    Aim:Toll-like receptor 2 (TLR2) signaling plays a critical role in the initiation of atherosclerosis.The aim of this study was to investigate whether blocking TLR2 activity could produce therapeutic effects on advanced atherosclerosis.Methods:Forty-week old apolipoprotein E-deficient (ApoE-/-) mice fed on a normal diet were intravenously injected with a TLR2-neutralizing antibody or with an isotype-matched IgG for 18 weeks.Double-knockout ApoE-/-Tlr2-/-mice were taken as a positive control.At the end of the treatments,the plasma lipid levels were measured,and the plaque morphology,pro-inflammatory cytokines expression and apoptosis in arteries were analyzed.In the second part of this study,6-week old ApoE-/-and ApoE-/-Tlr2-/-mice fed on a high-cholesterol diet for 12 to 24 weeks,the expression levels of TLR2 and apoptotic markers in arteries were examined.Results:Blockade of TLR2 activity with TLR2-neutralizing antibody or knockout of Tlr2 gene did not alter the plasma lipid levels in ApoE-/-mice.However,the pharmacologic and genetic manipulations significantly reduced the plaque size and vessel stenosis,and increased plaque stability in the brachiocephalic arteries.The protective effects of TLR2 antagonism were associated with the suppressed expression of pro-inflammatory cytokines IL-6 and TNF-α and the inactivation of transcription factors NF-KB and Stat3.In addition,blocking TLR2 activity attenuated ER stress-induced macrophage apoptosis in the brachiocephalic arteries,which could promote the resolution of necrotic cores in advanced atherosclerosis.Moreover,high-cholesterol diet more prominently accelerated atherosclerotic formation and increased the expression of pro-apoptotic protein CHOP and apoptosis in ApoE-/-mice than in ApoE-/-Tlr2-/-mice.Conclusion:The pharmacologic or genetic blockade of TLR2 activity diminishes and stabilizes advanced atherosclerotic lesions in ApoE-/-mice.Thus,targeting TLR2 signaling may be a promising therapeutic strategy against

  5. Apolipoprotein E gene polymorphisms are associated with primary hyperuricemia in a Chinese population.

    Directory of Open Access Journals (Sweden)

    Jie Wu

    Full Text Available OBJECTIVE: Primary hyperuricemia, an excess of uric acid in the blood, is a major public health problem. In addition to the morbidity that is attributable to gout, hyperuricemia is also associated with metabolic syndrome, hypertension, and cardiovascular disease. This study aims to assess the genetic associations between Apolipoprotein E (APOE polymorphisms and hyperuricemia in a Chinese population. METHODS: A total of 770 subjects (356 hyperuricemic cases and 414 normouricemic controls were recruited from the Ningxia Hui Autonomous Region, China. A physical examination was performed and fasting blood was collected for biochemical tests, including determination of the levels of serum lipid, creatinine, and uric acid. Multi-ARMS PCR was applied to determine the APOE genotypes, followed by an investigation of the distribution of APOE genotypes and alleles frequencies in the controls and cases. RESULTS: The frequencies of the APOE-ε2ε3 genotype (17.70% vs. 10.39%, P = 0.003 and the APOE-ε2 allele (10.53% vs. 5.80%, P = 0.001 were significantly higher in the hyperuricemic group than in the normouricemic group. Furthermore, male cases were more likely to have the APOE-ε2ε3 genotype and APOE-ε2 allele, compared with male controls. In both Han and Hui subjects, cases were more likely to have the APOE-ε2ε3 genotype and the APOE-ε2 allele compared with controls. Furthermore, multivariate logistic regression showed that carriers of the APOE-ε2ε3 genotype (P = 0.001, OR = 2.194 and the ε2 allele (P = 0.001, OR = 2.099 were significantly more likely to experience hyperuricemia than carriers of the ε3/ε3 genotype and the ε3 allele after adjustment for sex, body mass index (BMI, diastolic blood pressure (DBP, triglyceride (TG, low density lipoprotein cholesterol (LDL-C, creatinine (Cr and fasting blood glucose (FBG. CONCLUSIONS: The APOE-ε2ε3 genotype and the APOE-ε2 allele are associated with serum uric acid levels

  6. A Pressure-dependent Model for the Regulation of Lipoprotein Lipase by Apolipoprotein C-II*

    Science.gov (United States)

    Meyers, Nathan L.; Larsson, Mikael; Olivecrona, Gunilla; Small, Donald M.

    2015-01-01

    Apolipoprotein C-II (apoC-II) is the co-factor for lipoprotein lipase (LPL) at the surface of triacylglycerol-rich lipoproteins. LPL hydrolyzes triacylglycerol, which increases local surface pressure as surface area decreases and amphipathic products transiently accumulate at the lipoprotein surface. To understand how apoC-II adapts to these pressure changes, we characterized the behavior of apoC-II at multiple lipid/water interfaces. ApoC-II adsorption to a triacylglycerol/water interface resulted in large increases in surface pressure. ApoC-II was exchangeable at this interface and desorbed on interfacial compressions. These compressions increase surface pressure and mimic the action of LPL. Analysis of gradual compressions showed that apoC-II undergoes a two-step desorption, which indicates that lipid-bound apoC-II can exhibit at least two conformations. We characterized apoC-II at phospholipid/triacylglycerol/water interfaces, which more closely mimic lipoprotein surfaces. ApoC-II had a large exclusion pressure, similar to that of apoC-I and apoC-III. However, apoC-II desorbed at retention pressures higher than those seen with the other apoCs. This suggests that it is unlikely that apoC-I and apoC-III inhibit LPL via displacement of apoC-II from the lipoprotein surface. Upon rapid compressions and re-expansions, re-adsorption of apoC-II increased pressure by lower amounts than its initial adsorption. This indicates that apoC-II removed phospholipid from the interface upon desorption. These results suggest that apoC-II regulates the activity of LPL in a pressure-dependent manner. ApoC-II is provided as a component of triacylglycerol-rich lipoproteins and is the co-factor for LPL as pressure increases. Above its retention pressure, apoC-II desorbs and removes phospholipid. This triggers release of LPL from lipoproteins. PMID:26026161

  7. A genome-wide association meta-analysis on apolipoprotein A-IV concentrations.

    Science.gov (United States)

    Lamina, Claudia; Friedel, Salome; Coassin, Stefan; Rueedi, Rico; Yousri, Noha A; Seppälä, Ilkka; Gieger, Christian; Schönherr, Sebastian; Forer, Lukas; Erhart, Gertraud; Kollerits, Barbara; Marques-Vidal, Pedro; Ried, Janina; Waeber, Gerard; Bergmann, Sven; Dähnhardt, Doreen; Stöckl, Andrea; Kiechl, Stefan; Raitakari, Olli T; Kähönen, Mika; Willeit, Johann; Kedenko, Ludmilla; Paulweber, Bernhard; Peters, Annette; Meitinger, Thomas; Strauch, Konstantin; Study Group, Kora; Lehtimäki, Terho; Hunt, Steven C; Vollenweider, Peter; Kronenberg, Florian

    2016-08-15

    Apolipoprotein A-IV (apoA-IV) is a major component of HDL and chylomicron particles and is involved in reverse cholesterol transport. It is an early marker of impaired renal function. We aimed to identify genetic loci associated with apoA-IV concentrations and to investigate relationships with known susceptibility loci for kidney function and lipids. A genome-wide association meta-analysis on apoA-IV concentrations was conducted in five population-based cohorts (n = 13,813) followed by two additional replication studies (n = 2,267) including approximately 10 M SNPs. Three independent SNPs from two genomic regions were significantly associated with apoA-IV concentrations: rs1729407 near APOA4 (P = 6.77 × 10 (-)  (44)), rs5104 in APOA4 (P = 1.79 × 10(-)(24)) and rs4241819 in KLKB1 (P = 5.6 × 10(-)(14)). Additionally, a look-up of the replicated SNPs in downloadable GWAS meta-analysis results was performed on kidney function (defined by eGFR), HDL-cholesterol and triglycerides. From these three SNPs mentioned above, only rs1729407 showed an association with HDL-cholesterol (P = 7.1 × 10 (-)  (07)). Moreover, weighted SNP-scores were built involving known susceptibility loci for the aforementioned traits (53, 70 and 38 SNPs, respectively) and were associated with apoA-IV concentrations. This analysis revealed a significant and an inverse association for kidney function with apoA-IV concentrations (P = 5.5 × 10(-)(05)). Furthermore, an increase of triglyceride-increasing alleles was found to decrease apoA-IV concentrations (P = 0.0078). In summary, we identified two independent SNPs located in or next the APOA4 gene and one SNP in KLKB1 The association of KLKB1 with apoA-IV suggests an involvement of apoA-IV in renal metabolism and/or an interaction within HDL particles. Analyses of SNP-scores indicate potential causal effects of kidney function and by lesser extent triglycerides on apoA-IV concentrations.

  8. Skyrmions from Instantons inside Domain Walls

    CERN Document Server

    Eto, M; Ohashi, K; Tong, D; Eto, Minoru; Nitta, Muneto; Ohashi, Keisuke; Tong, David

    2005-01-01

    Some years ago, Atiyah and Manton described a method to construct approximate Skyrmion solutions from Yang-Mills instantons. Here we present a dynamical realization of this construction using domain walls in a five-dimensional gauge theory. The non-abelian gauge symmetry is broken in each vacuum but restored in the core of the domain wall, allowing instantons to nestle inside the wall. We show that the worldvolume dynamics of the wall is given by the Skyrme model, including the four-derivative term, and the instantons appear as Skyrmions.

  9. Strongly Semicontinuous Domains and Semi-FS Domains

    Directory of Open Access Journals (Sweden)

    Qingyu He

    2014-01-01

    Full Text Available We are mainly concerned with some special kinds of semicontinuous domains and relationships between them. New concepts of strongly semicontinuous domains, meet semicontinuous domains and semi-FS domains are introduced. It is shown that a dcpo L is strongly semicontinuous if and only if L is semicontinuous and meet semicontinuous. It is proved that semi-FS domains are strongly semicontinuous. Some interpolation properties of semiway-below relations in (strongly semicontinuous bc-domains are given. In terms of these properties, it is proved that strongly semicontinuous bc-domains, in particular strongly semicontinuous lattices, are all semi-FS domains.

  10. Structured hints : extracting and abstracting domain expertise.

    Energy Technology Data Exchange (ETDEWEB)

    Hereld, M.; Stevens, R.; Sterling, T.; Gao, G. R.; Mathematics and Computer Science; California Inst. of Tech.; Louisiana State Univ.; Univ. of Delaware

    2009-03-16

    We propose a new framework for providing information to help optimize domain-specific application codes. Its design addresses problems that derive from the widening gap between the domain problem statement by domain experts and the architectural details of new and future high-end computing systems. The design is particularly well suited to program execution models that incorporate dynamic adaptive methodologies for live tuning of program performance and resource utilization. This new framework, which we call 'structured hints', couples a vocabulary of annotations to a suite of performance metrics. The immediate target is development of a process by which a domain expert describes characteristics of objects and methods in the application code that would not be readily apparent to the compiler; the domain expert provides further information about what quantities might provide the best indications of desirable effect; and the interactive preprocessor identifies potential opportunities for the domain expert to evaluate. Our development of these ideas is progressing in stages from case study, through manual implementation, to automatic or semi-automatic implementation. In this paper we discuss results from our case study, an examination of a large simulation of a neural network modeled after the neocortex.

  11. Tumor necrosis factor-alpha impairs hepatic insulin signaling and stimulates the overproduction of hepatic apolipoprotein B100-containing very low density lipoproteins

    Science.gov (United States)

    Mechanisms underlying hepatic overproduction of apolipoprotein B (apoB) 100-containing very low density lipoproteins (VLDL) in insulin resistance induced by tumor necrosis factor (TNF)-a were investigated. In the present study, we examined the potential role of TNF-a in insulin signaling and lipopro...

  12. Mechanisms of cinnamon extract-induced suppression of the intestinal overproduction of apolipoprotein B48-containing lipoproteins in insulin resistant high-fructose fed animals

    Science.gov (United States)

    We have reported previously that cinnamon extract (CE) prevents high-fructose (HF) feeding-induced whole-body insulin resistance by enhancing insulin signaling in skeletal muscle. In this study, we investigated whether intestinal apolipoprotein overproduction is inhibited by CE in this insulin-resis...

  13. Tumor necrosis factor-alpha impairs hepatic insulin signaling and stumlates the overproduction of hepatic apolipoprotein B100-containing very low density lipoproteins

    Science.gov (United States)

    Mechanisms underlying hepatic overproduction of apolipoprotein B (apoB) 100-containing very low density lipoproteins (VLDL) in insulin resistance induced by tumor necrosis factor (TNF)-a were investigated. In the present study, we examined the potential role of TNF-a in insulin signaling and lipopro...

  14. Apolipoprotein AV and Metabolism of Blood Lipids%载脂蛋白AV与血脂代谢研究新进展

    Institute of Scientific and Technical Information of China (English)

    胡璐

    2011-01-01

    新发现的载脂蛋白AV参与血脂代谢,尤其是在三酰甘油分解代谢中起重要作用.载脂蛋白AV通过减少脂蛋白的生成率、增强脂蛋白脂酶对三酰甘油的水解,促进低密度脂蛋白受体介导的富含三酰甘油的脂蛋白颗粒清除作用来调节血脂代谢.载脂蛋白AV的基因多态性与心血管疾病的发生有着密切的关系.%Apolipoprotein AV, a newly discovered apolipoprotein, has been shown to play an important role in the metabolism of lip-ids. It is especially relevant to the metabolism of triglycerides primarily through reducing the lipoprotein production rate, stimulating hydrolysis of triglycerides by lipoprotein lipase, and facilitating clearance of triglyceride-rich lipoprotein by low-density lipoprotein receptor. It has been found that the polymorphism of apolipoprotein AV is closely related with coronary heart disease. This article reviews current literature and recent findings about the role of apolipoprotein AV in lipid metabolism.

  15. The effect of the apolipoprotein E genotype on response to personalized dietary advice intervention: Findings from the Food4Me randomized controlled trial

    NARCIS (Netherlands)

    Fallaize, R.; Celis-Morales, C.; MacReady, A.L.; Marsaux, C.F.M.; Forster, H.; O'Donovan, C.; Woolhead, C.; San-Cristobal, R.; Kolossa, S.; Hallmann, J.; Mavrogianni, C.; Surwillo, A.; Livingstone, K.M.; Moschonis, G.; Navas-Carretero, S.; Walsh, M.C.; Gibney, E.R.; Brennan, L.; Bouwman, J.; Grimaldi, K.; Manios, Y.; Traczyk, I.; Drevon, C.A.; Martinez, J.A.; Daniel, H.; Saris, W.H.M.; Gibney, M.J.; Mathers, J.C.; Lovegrove, J.A.

    2016-01-01

    Background: The apolipoprotein E (APOE) risk allele (e4) is associated with higher total cholesterol (TC), amplified response to saturated fatty acid (SFA) reduction, and increased cardiovascular disease. Although knowledge of gene risk may enhance dietary change, it is unclear whether e4 carriers w

  16. Reduced levels of cholesterol, phospholipids, and fatty acids in cerebrospinal fluid of Alzheimer disease patients are not related to apolipoprotein E4

    NARCIS (Netherlands)

    Mulder, M.; Ravid, R.; Kloet, J.E.R. de; Haasdijk, E.D.; Julk, J.; Boom, J. van der; Havekes, L.M.

    1998-01-01

    Apolipoprotein E4 (apoE4) has been identified as a major risk factor for Alzheimer disease (AD). Previously it has been reported that levels of apoE are reduced in cerebrospinal fluid (CSF) of AD patients. Because it is known that apoE4 affectss plasma lipid metabolism we examined whether the presen

  17. Dietary Soy Protein Isolate Ameliorates Atherosclerotic Lesions in Apolipoprotein E-Deficient Mice Potentially by Inhibiting Monocyte Chemoattractant Protein-1 Expression

    Science.gov (United States)

    Soy-based diets reportedly protect against the development of atherosclerosis; however, the underlying mechanism(s) for this protection remains unknown. In this report, the mechanism(s) contributing to the atheroprotective effects of a soy-based diet was addressed using the apolipoprotein E knockout...

  18. Domains in Ferroelectric Nanostructures

    Science.gov (United States)

    Gregg, Marty

    2010-03-01

    Ferroelectric materials have great potential in influencing the future of small scale electronics. At a basic level, this is because ferroelectric surfaces are charged, and so interact strongly with charge-carrying metals and semiconductors - the building blocks for all electronic systems. Since the electrical polarity of the ferroelectric can be reversed, surfaces can both attract and repel charges in nearby materials, and can thereby exert complete control over both charge distribution and movement. It should be no surprise, therefore, that microelectronics industries have already looked very seriously at harnessing ferroelectric materials in a variety of applications, from solid state memory chips (FeRAMs) to field effect transistors (FeFETs). In all such applications, switching the direction of the polarity of the ferroelectric is a key aspect of functional behavior. The mechanism for switching involves the field-induced nucleation and growth of domains. Domain coarsening, through domain wall propagation, eventually causes the entire ferroelectric to switch its polar direction. It is thus the existence and behavior of domains that determine the switching response, and ultimately the performance of the ferroelectric device. A major issue, associated with the integration of ferroelectrics into microelectronic devices, has been that the fundamental properties associated with ferroelectrics, when in bulk form, appear to change quite dramatically and unpredictably when at the nanoscale: new modes of behaviour, and different functional characteristics from those seen in bulk appear. For domains, in particular, the proximity of surfaces and boundaries have a dramatic effect: surface tension and depolarizing fields both serve to increase the equilibrium density of domains, such that minor changes in scale or morphology can have major ramifications for domain redistribution. Given the importance of domains in dictating the overall switching characteristics of a device

  19. Financial Derivatives

    DEFF Research Database (Denmark)

    Wigan, Duncan

    2013-01-01

    Contemporary derivatives mark the development of capital and constitute a novel form of ownership. By reconfiguring the temporal, spatial and legal character of ownership derivatives present a substantive challenge to the tax collecting state. While fiscal systems are nationally bounded and inheren...... and inherently static, capital itself is unprecedentedly mobile, fluid and fungible. As such derivatives raise the specter of ‘financial weapons of mass destruction’....

  20. Derivations and Generating Degrees in the Ring of Arithmetical Functions

    Indian Academy of Sciences (India)

    Alexandru Zaharescu; Mohammad Zaki

    2007-05-01

    In this paper we study a family of derivations in the ring of arithmetical functions of several variables over an integral domain, and compute the generating degrees of the ring of arithmetical functions over the kernel of these derivations.

  1. Power optimization for domain wall motion in ferromagnetic nanowires

    Science.gov (United States)

    Tretiakov, O. A.; Liu, Y.; Abanov, Ar.

    2011-04-01

    The current mediated domain-wall dynamics in a thin ferromagnetic wire is investigated. We derive the effective equations of motion of the domain wall. They are used to study the possibility to optimize the power supplied by electric current for the motion of domain walls in a nanowire. We show that a certain resonant time-dependent current moving a domain wall can significantly reduce the Joule heating in the wire, and thus it can lead to a novel proposal for the most energy efficient memory devices. We discuss how Gilbert damping, nonadiabatic spin transfer torque, and the presence of Dzyaloshinskii-Moriya interaction can effect this power optimization.

  2. Power optimization for domain wall motion in ferromagnetic nanowires

    OpenAIRE

    Tretiakov, Oleg A.; Liu, Y.; Abanov, Ar.

    2010-01-01

    The current mediated domain-wall dynamics in a thin ferromagnetic wire is investigated. We derive the effective equations of motion of the domain wall. They are used to study the possibility to optimize the power supplied by electric current for the motion of domain walls in a nanowire. We show that a certain resonant time-dependent current moving a domain wall can significantly reduce the Joule heating in the wire, and thus it can lead to a novel proposal for the most energy efficient memory...

  3. Age-related cognitive decline and associations with sex, education and apolipoprotein E genotype across ethnocultural groups and geographic regions: a collaborative cohort study

    Science.gov (United States)

    Lipnicki, Darren M.; Crawford, John D.; Thalamuthu, Anbupalam; Castro-Costa, Erico; Stephan, Blossom C. M.; Lipton, Richard B.; Katz, Mindy J.; Ritchie, Karen; Scali, Jacqueline; Ancelin, Marie-Laure; Scarmeas, Nikolaos; Yannakoulia, Mary; Dardiotis, Efthimios; Lam, Linda C. W.; Fung, Ada W. T.; Vaccaro, Roberta; Davin, Annalisa; Kim, Ki Woong; Han, Ji Won; Kim, Tae Hui; Cherbuin, Nicolas; Butterworth, Peter; Scazufca, Marcia; Kumagai, Shuzo; Chen, Sanmei; Narazaki, Kenji; Lobo, Antonio; Lopez-Anton, Raúl; Santabárbara, Javier; Sachdev, Perminder S.

    2017-01-01

    Background The prevalence of dementia varies around the world, potentially contributed to by international differences in rates of age-related cognitive decline. Our primary goal was to investigate how rates of age-related decline in cognitive test performance varied among international cohort studies of cognitive aging. We also determined the extent to which sex, educational attainment, and apolipoprotein E ε4 allele (APOE*4) carrier status were associated with decline. Methods and findings We harmonized longitudinal data for 14 cohorts from 12 countries (Australia, Brazil, France, Greece, Hong Kong, Italy, Japan, Singapore, Spain, South Korea, United Kingdom, United States), for a total of 42,170 individuals aged 54–105 y (42% male), including 3.3% with dementia at baseline. The studies began between 1989 and 2011, with all but three ongoing, and each had 2–16 assessment waves (median = 3) and a follow-up duration of 2–15 y. We analyzed standardized Mini-Mental State Examination (MMSE) and memory, processing speed, language, and executive functioning test scores using linear mixed models, adjusted for sex and education, and meta-analytic techniques. Performance on all cognitive measures declined with age, with the most rapid rate of change pooled across cohorts a moderate -0.26 standard deviations per decade (SD/decade) (95% confidence interval [CI] [-0.35, -0.16], p < 0.001) for processing speed. Rates of decline accelerated slightly with age, with executive functioning showing the largest additional rate of decline with every further decade of age (-0.07 SD/decade, 95% CI [-0.10, -0.03], p = 0.002). There was a considerable degree of heterogeneity in the associations across cohorts, including a slightly faster decline (p = 0.021) on the MMSE for Asians (-0.20 SD/decade, 95% CI [-0.28, -0.12], p < 0.001) than for whites (-0.09 SD/decade, 95% CI [-0.16, -0.02], p = 0.009). Males declined on the MMSE at a slightly slower rate than females (difference = 0

  4. Just how versatile are domains?

    Directory of Open Access Journals (Sweden)

    Bornberg-Bauer Erich

    2008-10-01

    Full Text Available Abstract Background Creating new protein domain arrangements is a frequent mechanism of evolutionary innovation. While some domains always form the same combinations, others form many different arrangements. This ability, which is often referred to as versatility or promiscuity of domains, its a random evolutionary model in which a domain's promiscuity is based on its relative frequency of domains. Results We show that there is a clear relationship across genomes between the promiscuity of a given domain and its frequency. However, the strength of this relationship differs for different domains. We thus redefine domain promiscuity by defining a new index, DV I ("domain versatility index", which eliminates the effect of domain frequency. We explore links between a domain's versatility, when unlinked from abundance, and its biological properties. Conclusion Our results indicate that domains occurring as single domain proteins and domains appearing frequently at protein termini have a higher DV I. This is consistent with previous observations that the evolution of domain re-arrangements is primarily driven by fusion of pre-existing arrangements and single domains as well as loss of domains at protein termini. Furthermore, we studied the link between domain age, defined as the first appearance of a domain in the species tree, and the DV I. Contrary to previous studies based on domain promiscuity, it seems as if the DV I is age independent. Finally, we find that contrary to previously reported findings, versatility is lower in Eukaryotes. In summary, our measure of domain versatility indicates that a random attachment process is sufficient to explain the observed distribution of domain arrangements and that several views on domain promiscuity need to be revised.

  5. The Peculiar Evolution of Apolipoprotein(a) in Human and Rhesus Macaque

    Science.gov (United States)

    Pesole, G.; Gerardi, A.; di-Jeso, F.; Saccone, C.

    1994-01-01

    Apo(a) is a low density lipoprotein homologous to plasminogen and has been shown to be involved in coronary atheroschlerosis. In the present paper we will try to analyze the interesting evolutionary pattern of Apo(a). The plasminogen gene contains 5 cysteine-rich sequences, called kringles, followed by a protease domain. Apo(a), probably arisen by duplication of an ancestral plasminogen gene, contains many tandemly repeated copies of a sequence domain similar to the fourth kringle of plasminogen, 37 in human and at least 10 in the partially sequenced gene of rhesus, and the protease domain. We have found that the upstream kringles of apo(a) undergo Molecular Drive-like processes that produce high intraspecies similarity, whereas the downstream kringles evolve in a molecular clock-like manner and show an high interspecies sequence similarity. The latter regions are obviously suitable for dating the duplication event by which Apo(a) arose from plasminogen, but only if they evolve at the same rate in the two genes. Thus, we propose a ``Molecular Clock Test'' for assessing whether the comparison of two paralogous genes (or gene regions) can give reliable information on the dating of their origin by duplication. Applying this test to the kringle-4 domain of apo(a) and plasminogen gene, we demonstrate that the separation between the two genes by duplication dates back at about 90 Mya immediately before the radiation of mammals. PMID:8138162

  6. Axion domain wall baryogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Daido, Ryuji; Kitajima, Naoya [Department of Physics, Tohoku University,Sendai 980-8578 (Japan); Takahashi, Fuminobu [Department of Physics, Tohoku University,Sendai 980-8578 (Japan); Kavli IPMU, TODIAS, University of Tokyo,Kashiwa 277-8583 (Japan)

    2015-07-28

    We propose a new scenario of baryogenesis, in which annihilation of axion domain walls generates a sizable baryon asymmetry. Successful baryogenesis is possible for a wide range of the axion mass and decay constant, m≃10{sup 8}–10{sup 13} GeV and f≃10{sup 13}–10{sup 16} GeV. Baryonic isocurvature perturbations are significantly suppressed in our model, in contrast to various spontaneous baryogenesis scenarios in the slow-roll regime. In particular, the axion domain wall baryogenesis is consistent with high-scale inflation which generates a large tensor-to-scalar ratio within the reach of future CMB B-mode experiments. We also discuss the gravitational waves produced by the domain wall annihilation and its implications for the future gravitational wave experiments.

  7. Hydrogen sulfide regulates vascular endoplasmic reticulum stress in apolipoprotein E knockout mice

    Institute of Scientific and Technical Information of China (English)

    CHEN Zhi-fang; ZHAO Bin; TANG Xiu-ying; LI Wei; ZHU Lu-lu; TANG Chao-shu; DU Jun-bao; JIN Hong-fang

    2011-01-01

    Background Atherosclerosis is an important cardiovascular disease,becoming a major and increasing health problem in developed countries.However,the possible underlying mechanisms were not completely clear.In 2009,our research group first discovered that hydrogen sulfide (H2S) as a novel gastrotransmitter played an important anti-atherosclerotic role.The study was designed to examine the regulatory effect of hydrogen sulfide (H2S) on endoplasmic reticulum stress (ERS) in apolipoprotein E knockout (apoE(-/-)) mice fed a Western type diet.Methods C57BL/6 mice and homozygous apoE(-/-) mice were fed a Western type diet.C57BL/6 mice were injected intraperitoneally with normal saline (5 ml/kg per day) as control group.The apoE+ mice were treated with the same dose of normal saline as the apoE(-/-) group,injected intraperitoneally with sodium hydrosulfide (NaHS,an H2S donor,56μmol/kg per day) as the apoE(-/-)+NaHS group and injected intraperitoneally with DL-propargylglycine (PPG,a cystathionine-y-lyase inhibitor,50 mg/kg,per day) as the apoE/ +PPG group.After 10 weeks,the mice were sacrificed and the plasma lipids were detected.Sections of aortic root from these animals were examined for atherosclerotic lesions by HE and oil red O staining.The aortic ultrastructure and microstructure were analyzed with the help of light and electronic microscope.Glucose-regulated protein 78 (GRP78),caspase-12,copper-andzinc-containing superoxide dismutase (Cu/ZnSOD) and Mn-containing superoxide dismutase (MnSOD) protein expression in aortic tissues were detected with immunohistochemistry.The level of intracellular reactive oxygen species (ROS) were measured by using a commercial assay kit.Results Compared with control mice,apoE(-/-) mice showed increased plasma levels of total cholesterol (TC),triglyceride (TG) and low density lipoprotein (LDL),decreased high density lipoprotein (HDL),increased aortic plaque size,destroyed ultra-structure of aortic tissue,and increased expression of GRP

  8. APOLIPOPROTEÍNA E Y ENFERMEDAD CARDIOVASCULAR Apolipoprotein E and cardiovascular disease

    Directory of Open Access Journals (Sweden)

    Adriana Moreno Valladares

    2006-03-01

    Full Text Available La apolipoproteína E es una glicoproteína polimórfica que interactúa con los receptores de lipoproteínas (LRP-Receptor Related Protein o receptores ApoE y los receptores de lipoproteínas de baja densidad (receptores LDL. Cuando las lipoproteínas se unen al receptor comienza la captación y degradación de lípidos por parte de la célula, lo que permite la utilización del colesterol contenido en las lipoproteínas, produciéndose una autorregulación intracelular La tres isoformas de mayor importancia de ApoE se denominan Apo E2, E3 y E4 y son producto de tres alelos e2, e3, e4 de un gen único. Este factor está relacionado con la cantidad de lipoproteínas que contienen ApoE para receptores E⁄B. El menor contenido de lipoproteínas con ApoE puede aumentar la actividad del receptor LDL y consecuentemente, bajar la concentración de LDL en circulación. De otra parte, las partículas con Apo E3 o Apo E4, causan disminución de la regulación de receptores LDL y producen elevación del LDL plasmático. Muchos estudios en poblaciones humanas han demostrado la relación entre este polimorfismo de apoE y la variación en los niveles plasmáticos de lípidos y de lipoproteínas y el riesgo de desarrollar enfermedad cardiovascular. La enfermedad cardiovascular es el resultado de la interacción de diferentes factores entre los que se encuentra el factor genético y específicamente el polimorfismo de la ApoE. La presencia del alelo e4 de la ApoE puede explicar, en parte, la mayor frecuencia de enfermedad cardiovascular en quienes lo portan.Apolipoprotein E is a polymorphic glycoprotein who interacts with the lipoprotein receptors (LRP-Receptor Related Protein and the receptors for low density lipoproteins of (LDL receptors. When lipoproteins bring up the receptors begins lipids captation and degradation which allows cholesterol utilization, taking place an intracellular auto regulation. The three isoforms of greater importance: Apo E2, E3

  9. Expression of human apolipoprotein E4 reduces insulin-receptor substrate 1 expression and Akt phosphorylation in the ageing liver

    Directory of Open Access Journals (Sweden)

    Qi-Rui Ong

    2014-01-01

    Full Text Available The diabetic drug rosiglitazone was reported to improve glucose tolerance in insulin-resistant ApoE3 but not ApoE4 knock-in mice. We therefore examined whether apolipoprotein E (ApoE has genotype-specific effects on liver insulin function. At 12 weeks, no difference in liver insulin signaling was detected between fasting ApoE3 and ApoE4 mice. At 72 weeks however, ApoE4 mice had lower IRS-1 and PI3K expression, and reduced Akt phosphorylation. This decline was associated with lower insulin and higher glucose in ApoE4 mouse liver. Liver cholesterol was not affected. These results show that ApoE4 expression reduces liver insulin signaling and insulin levels, leading to higher glucose content.

  10. Apolipoprotein E polymorphism as a predictor for cognitive decline and dementia in the Saudi general population over 65 years

    Directory of Open Access Journals (Sweden)

    Abdulaziz Ali A. Al-Khedhairy

    2004-01-01

    Full Text Available Specific Apolipoprotein E (ApoE genotypes are thought to be associated with risk for Alzheimer's disease (AD. It is essential to understand how this genetic factor affects cognitive decline and dementia in the general population. One hundred and fifty elderly persons residing at social nursing centers in different provinces of Saudi Arabia were tested for ApoE genotypes, using PCR amplification of genomic DNA followed by DNA digestion with Cfo I. All subjects were diagnosed with regard to cognitive decline and dementia. In the general Saudi population, the ApoE4 allele was found to be a weaker predictor for dementia than for AD. This may be a result of non-AD pathological processes and/or of most prevalent dementia at an age when the ApoE4 effect on the AD/dementia risk has decreased.

  11. Influence of apolipoprotein E and its receptors on cerebral amyloid precursor protein metabolism following traumatic brain injury

    Institute of Scientific and Technical Information of China (English)

    ZHOU Shuai; SUN Xiao-chuan

    2012-01-01

    Traumatic brain injury (TBI) is the leading cause of mortality and disability among young individuals in our society,and globally the incidence of TBI is rising sharply.Mounting evidence has indicated that apolipoprotein E (apoE:protein; APOE:gene) genotype influences the outcome after TBI.The proposed mechanism by which APOE affects the clinicopathological consequences of TBI is multifactorial and includes amyloid deposition,disruption of lipid distribution,dysfunction of mitochondrial energy production,oxidative stress and increases intracellular calcium in response to injury.This paper reviews the current state of knowledge regarding the influence of apoE and its receptors on cerebral amyloid betaprotein precursor metabolism following TBI.

  12. Apolipoprotein E gene polymorphism and dyslipidaemia in adult Asian Indians: A population based study from calcutta, India

    Directory of Open Access Journals (Sweden)

    Das Mithun

    2008-01-01

    Full Text Available Aim : The study was aimed to determine the association of Apolipoprotein E (apo E gene polymorphisms on lipid levels in Asian Indian population. Methods : A total of 350 (184 males and 166 females adult (30 years and above Asian Indians of Calcutta and suburb participated in the study. Anthropometric measures, lipids profiles, and blood glucose measures were collected. Out of 350 subjects, a sample of 70 individuals was selected randomly for genotyping after adjusting for age and sex. The apo E gene polymorphisms were determined by agarose gel electrophoresis. Results : The apo E polymorphism showed significant association with dyslipidaemia (P=0.0135 with e3/4 combination has had the highest occurrence of dyslipidaemia and metabolic syndrome (MS followed by ε4/4 Conclusions : The ε4 allele of apo E gene independent of other risk factors is associated with dyslipidaemia in particular with low HDLc and high TC: HDLc ratio.

  13. Evidence for apolipoprotein E {epsilon}4 association in early-onset Alzheimer`s patients with late-onset relatives

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Tur, J.; Delacourte, A.; Chartier-Harlin, M.C. [INSERM, Rouen (France)] [and others

    1995-12-18

    Recently several reports have extended the apolipoprotein E (APOE) {epsilon}4 association found in late-onset Alzheimer`s disease (LOAD) patients to early-onset (EO) AD patients. We have studied this question in a large population of 119 EOAD patients (onset {<=}60 years) in which family history was carefully assessed and in 109 controls. We show that the APOE {epsilon}A allele frequency is increased only in the subset of patients who belong to families where LOAD secondary cases are present. Our sampling scheme permits us to demonstrate that, for an individual, bearing at least one {epsilon}4 allele increases both the risk of AD before age 60 and the probability of belonging to a family with late-onset affected subjects. Our results suggest that a subset of EOAD cases shares a common determinism with LOAD cases. 19 refs., 3 tabs.

  14. Plasma clearance of human low-density lipoprotein in human apolipoprotein B transgenic mice is related to particle diameter.

    Science.gov (United States)

    Berneis, Kaspar; Shames, David M; Blanche, Patricia J; La Belle, Michael; Rizzo, Manfredi; Krauss, Ronald M

    2004-04-01

    To test for intrinsic differences in metabolic properties of low-density lipoprotein (LDL) as a function of particle size, we examined the kinetic behavior of 6 human LDL fractions ranging in size from 251 to 265 A injected intravenously into human apolipoprotein (apo) B transgenic mice. A multicompartmental model was formulated and fitted to the data by standard nonlinear regression using the Simulation, Analysis and Modeling (SAAM II) program. Smaller sized LDL particles (251 to 257 A) demonstrated a significantly slower fractional catabolic rate (FCR) (0.050 +/- 0.045 h(-1)) compared with particles of larger size (262 to 265 A) (0.134 +/- -0.015 h(-1), P particles are cleared more slowly from plasma than larger LDL and are exchanged more slowly with the extravascular space. This might be due to compositional or structural features of smaller LDL that lead to retarded clearance.

  15. Cloning and Expression of Apolipoprotein E3 and Its Variant apoE2 and apoE4

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In order to obtain three isoforms of apolipoprotein E (apoE), the cDNA encoding apoE3 was obtained by RT-PCR from normal human liver tissue. Site-directed mutagenesis was used to obtain the cDNAs encoding apoE2 and apoE4 isoforms. The 3 cDNAs were subcloned into vector pGEM-3Z and verified by DNA sequencing. The expression recombinant which can express the target protein as a (His) 6-tagged fusion was constructed by subcloning apoE cDNA into vector pT7-PL. The purified proteins were gained by Ni-NTA column. The SDS-PAGE results revealed the 6 His fusion proteins (apoE2, apoE3 and apoE4) were correctly expressed and purified successfully.

  16. The Immune-Modulatory Role of Apolipoprotein E with Emphasis on Multiple Sclerosis and Experimental Autoimmune Encephalomyelitis

    Directory of Open Access Journals (Sweden)

    Hong-Liang Zhang

    2010-01-01

    Full Text Available Apolipoprotein E (apoE is a 34.2 kDa glycoprotein characterized by its wide tissue distribution and multiple functions. The nonlipid-related properties of apoE include modulating inflammation and oxidation, suppressing T cell proliferation, regulating macrophage functions, and facilitating lipid antigen presentation by CD1 molecules to natural killer T (NKT cells, and so forth. Increasing studies have revealed that APOE ε allele might be associated with multiple sclerosis (MS, although evidence is still not sufficient enough. In this review, we summarized the current progress of the immunomodulatory functions of apoE, with special focus on the association of APOE ε allele with the clinical features of MS and of its animal model experimental autoimmune encephalomyelitis (EAE.

  17. Are men carrying the apolipoprotein epsilon 4- or epsilon 2 allele less fertile than epsilon 3 epsilon 3 genotypes?

    DEFF Research Database (Denmark)

    Gerdes, Lars Ulrik; Gerdes, C; Hansen, P S;

    1996-01-01

    The epsilon 3 allele in the human gene coding for apolipoprotein E (apoE) is the most common worldwide, but epsilon 4 is probably the ancestral allele. Since apoE is involved in many important biological processes, selection forces could have favoured epsilon 3. We hypothesized that apoE genotypes...... may affect reproductive efficiency, and we therefore compared the distributions of 40-year-old married men with known genotypes by the numbers of their biological children. The distributions were statistically significantly different (P = 0.0026). On average, men with the epsilon 3 epsilon 3 genotype...... (n = 212) had 1.93 children, men with the epsilon 3 epsilon 4 or epsilon 4 epsilon 4 genotype (n = 105) had 1.50, and men with the epsilon 3 epsilon 2 or epsilon 2 epsilon 2 genotypes (n = 53) had 1.66 children. Of the men in the three groups, 6%, 26% and 19%, respectively, reported being childless...

  18. Bounded Densities and Their Derivatives: Extension to Other Domains

    DEFF Research Database (Denmark)

    Kozine, Igor; Krymsky, Victor

    2009-01-01

    . This paper presents a short introductory discussion on the general area of impecision in statistical theory and practice, and briefly introduces the further papers in this collection, demonstrating the importance of the adequate modelling of imprecision in different aeras of application....

  19. Domain Specific Software Architecture for Design Center Automation

    CERN Document Server

    Sinha, Anshuman; Balakrishna, Vijaya

    2008-01-01

    Domain specific software architecture aims at software reuse through construction of domain architecture reference model. The constructed reference model presents a set of individual components and their interaction points. When starting on a new large software project, the design engineer starts with pre-constructed model, which can be easily browsed and picks up opportunities of use in the new solution design. This report discusses application of domain reference design methods by deriving domain specific reference architecture for a product ordering system in a design center. The product in this case is instock and special order blinds from different manufacturers in a large supply store. The development of mature domain specific reference software architecture for this domain is not the objective of this report. However, this report would like to capture the method used in one such process and that is the primary concern of this report. This report lists subjective details of such a process applied to the...

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

    Energy Technology Data Exchange (ETDEWEB)

    Orlov, Sergey V., E-mail: serge@iem.sp.ru [Department of Biochemistry, Institute of Experimental Medicine, Russian Academy of Medical Sciences, 197376 St. Petersburg (Russian Federation); Department of Embryology, St. Petersburg State University, 199034 St. Petersburg (Russian Federation); Mogilenko, Denis A. [Department of Biochemistry, Institute of Experimental Medicine, Russian Academy of Medical Sciences, 197376 St. Petersburg (Russian Federation); Department of Embryology, St. Petersburg State University, 199034 St. Petersburg (Russian Federation); Shavva, Vladimir S. [Department of Embryology, St. Petersburg State University, 199034 St. Petersburg (Russian Federation); Dizhe, Ella B.; Ignatovich, Irina A. [Department of Biochemistry, Institute of Experimental Medicine, Russian Academy of Medical Sciences, 197376 St. Petersburg (Russian Federation); Perevozchikov, Andrej P., E-mail: app@iem.sp.ru [Department of Biochemistry, Institute of Experimental Medicine, Russian Academy of Medical Sciences, 197376 St. Petersburg (Russian Federation); Department of Embryology, St. Petersburg State University, 199034 St. Petersburg (Russian Federation)

    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.