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Sample records for a-i apo a-i

  1. ApoA-I mimetics.

    PubMed

    Stoekenbroek, R M; Stroes, E S; Hovingh, G K

    2015-01-01

    A wealth of evidence indicates that plasma levels of high-density lipoprotein cholesterol (HDL-C) are inversely related to the risk of cardiovascular disease (CVD). Consequently, HDL-C has been considered a target for therapy in order to reduce the residual CVD burden that remains significant, even after application of current state-of-the-art medical interventions. In recent years, however, a number of clinical trials of therapeutic strategies that increase HDL-C levels failed to show the anticipated beneficial effect on CVD outcomes. As a result, attention has begun to shift toward strategies to improve HDL functionality, rather than levels of HDL-C per se. ApoA-I, the major protein component of HDL, is considered to play an important role in many of the antiatherogenic functions of HDL, most notably reverse cholesterol transport (RCT), and several therapies have been developed to mimic apoA-I function, including administration of apoA-I, mutated variants of apoA-I, and apoA-I mimetic peptides. Based on the potential anti-inflammatory effects, apoA-I mimetics hold promise not only as anti-atherosclerotic therapy but also in other therapeutic areas.

  2. Apolipoprotein A-I modulates regulatory T cells in autoimmune LDLr-/-, ApoA-I-/- mice.

    PubMed

    Wilhelm, Ashley J; Zabalawi, Manal; Owen, John S; Shah, Dharika; Grayson, Jason M; Major, Amy S; Bhat, Shaila; Gibbs, Dwayne P; Thomas, Michael J; Sorci-Thomas, Mary G

    2010-11-12

    The immune system is complex, with multiple layers of regulation that serve to prevent the production of self-antigens. One layer of regulation involves regulatory T cells (Tregs) that play an essential role in maintaining peripheral self-tolerance. Patients with autoimmune diseases such as systemic lupus erythematosus and rheumatoid arthritis have decreased levels of HDL, suggesting that apoA-I concentrations may be important in preventing autoimmunity and the loss of self-tolerance. In published studies, hypercholesterolemic mice lacking HDL apoA-I or LDLr(-/-), apoA-I(-/-) (DKO), exhibit characteristics of autoimmunity in response to an atherogenic diet. This phenotype is characterized by enlarged cholesterol-enriched lymph nodes (LNs), as well as increased T cell activation, proliferation, and the production of autoantibodies in plasma. In this study, we investigated whether treatment of mice with lipid-free apoA-I could attenuate the autoimmune phenotype. To do this, DKO mice were first fed an atherogenic diet containing 0.1% cholesterol, 10% fat for 6 weeks, after which treatment with apoA-I was begun. Subcutaneous injections of 500 μg of lipid-free apoA-I was administered every 48 h during the treatment phase. These and control mice were maintained for an additional 6 weeks on the diet. At the end of the 12-week study, DKO mice showed decreased numbers of LN immune cells, whereas Tregs were proportionately increased. Accompanying this increase in Tregs was a decrease in the percentage of effector/effector memory T cells. Furthermore, lipid accumulation in LN and skin was reduced. These results suggest that treatment with apoA-I reduces inflammation in DKO mice by augmenting the effectiveness of the LN Treg response.

  3. ABCA1 (ATP-Binding Cassette Transporter A1) Mediates ApoA-I (Apolipoprotein A-I) and ApoA-I Mimetic Peptide Mobilization of Extracellular Cholesterol Microdomains Deposited by Macrophages.

    PubMed

    Jin, Xueting; Sviridov, Denis; Liu, Ying; Vaisman, Boris; Addadi, Lia; Remaley, Alan T; Kruth, Howard S

    2016-12-01

    We examined the function of ABCA1 (ATP-binding cassette transporter A1) in ApoA-I (apolipoprotein A-I) mobilization of cholesterol microdomains deposited into the extracellular matrix by cholesterol-enriched macrophages. We have also determined whether an ApoA-I mimetic peptide without and with complexing to sphingomyelin can mobilize macrophage-deposited cholesterol microdomains. Extracellular cholesterol microdomains deposited by cholesterol-enriched macrophages were detected with a monoclonal antibody, 58B1. ApoA-I and an ApoA-I mimetic peptide 5A mobilized cholesterol microdomains deposited by ABCA1(+/+) macrophages but not by ABCA1(-/-) macrophages. In contrast, ApoA-I mimetic peptide 5A complexed with sphingomyelin could mobilize cholesterol microdomains deposited by ABCA1(-/-) macrophages. Our findings show that a unique pool of extracellular cholesterol microdomains deposited by macrophages can be mobilized by both ApoA-I and an ApoA-I mimetic peptide but that mobilization depends on macrophage ABCA1. It is known that ABCA1 complexes ApoA-I and ApoA-I mimetic peptide with phospholipid, a cholesterol-solubilizing agent, explaining the requirement for ABCA1 in extracellular cholesterol microdomain mobilization. Importantly, ApoA-I mimetic peptide already complexed with phospholipid can mobilize macrophage-deposited extracellular cholesterol microdomains even in the absence of ABCA1. © 2016 American Heart Association, Inc.

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

    PubMed

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

    2013-03-01

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

  5. The unsolved mystery of apoA-I recycling in adipocyte.

    PubMed

    Wang, Shuai; Peng, Dao-quan; Yi, Yuhong

    2016-02-24

    As the major storage site for triglycerides and free cholesterol, adipose tissue plays a central role in energy metabolism. ApoA-I is the main constituent of HDL and plays an important role in removal of excess cholesterol from peripheral tissues. Recently, multiple studies have shown beneficial effects of apoA-I on adipose metabolism and function. ApoA-I was reported to improve insulin sensitivity and exert anti-inflammatory, anti-obesity effect in animal studies. Interestingly, Uptake and resecretion of apoA-I by adipocytes has been detected. However, the significance of apoA-I recycling by adipocytes is still not clear. This article reviewed methods used to study cellular recycling of apoA-I and summarized the current knowledge on the mechanisms involved in apoA-I uptake by adipocytes. Since the main function of apoA-I is to mediate reverse cholesterol transport from peripheral tissues, the role of apoA-I internalization and re-secretion by adipocytes in intracellular cholesterol transport under physiological and pathological conditions were discussed. In addition, findings on the correlation between apoA-I recycling and obesity were discussed. Finally, it was proposed that during intracellular transport, apoA-I-protein complex may acquire cargoes other than lipids and deliver regulatory information when they were resecreted into the plasma. Although apoA-I recycling by adipocytes is still an unsolved mystery, it's likely that it is more than a redundant pathway especially under pathological conditions.

  6. Dietary Strategies and Novel Pharmaceutical Approaches Targeting Serum ApoA-I Metabolism: A Systematic Overview

    PubMed Central

    Smolders, Lotte; Plat, Jogchum

    2017-01-01

    The incidence of CHD is still increasing, which underscores the need for new preventive and therapeutic approaches to decrease CHD risk. In this respect, increasing apoA-I concentrations may be a promising approach, especially through increasing apoA-I synthesis. This review first provides insight into current knowledge on apoA-I production, clearance, and degradation, followed by a systematic review of dietary and novel pharmacological approaches to target apoA-I metabolism. For this, a systematic search was performed to identify randomized controlled intervention studies that examined effects of whole foods and (non)nutrients on apoA-I metabolism. In addition, novel pharmacological approaches were searched for, which were specifically developed to target apoA-I metabolism. We conclude that both dietary components and pharmacological approaches can be used to increase apoA-I concentrations or functionality. For the dietary components in particular, more knowledge about the underlying mechanisms is necessary, as increasing apoA-I per se does not necessarily translate into a reduced CHD risk. PMID:28695008

  7. ApoA-I mimetic administration, but not increased apoA-I-containing HDL, inhibits tumour growth in a mouse model of inherited breast cancer

    PubMed Central

    Cedó, Lídia; García-León, Annabel; Baila-Rueda, Lucía; Santos, David; Grijalva, Victor; Martínez-Cignoni, Melanie Raquel; Carbó, José M.; Metso, Jari; López-Vilaró, Laura; Zorzano, Antonio; Valledor, Annabel F.; Cenarro, Ana; Jauhiainen, Matti; Lerma, Enrique; Fogelman, Alan M.; Reddy, Srinivasa T.; Escolà-Gil, Joan Carles; Blanco-Vaca, Francisco

    2016-01-01

    Low levels of high-density lipoprotein cholesterol (HDLc) have been associated with breast cancer risk, but several epidemiologic studies have reported contradictory results with regard to the relationship between apolipoprotein (apo) A-I and breast cancer. We aimed to determine the effects of human apoA-I overexpression and administration of specific apoA-I mimetic peptide (D-4F) on tumour progression by using mammary tumour virus-polyoma middle T-antigen transgenic (PyMT) mice as a model of inherited breast cancer. Expression of human apoA-I in the mice did not affect tumour onset and growth in PyMT transgenic mice, despite an increase in the HDLc level. In contrast, D-4F treatment significantly increased tumour latency and inhibited the development of tumours. The effects of D-4F on tumour development were independent of 27-hydroxycholesterol. However, D-4F treatment reduced the plasma oxidized low-density lipoprotein (oxLDL) levels in mice and prevented oxLDL-mediated proliferative response in human breast adenocarcinoma MCF-7 cells. In conclusion, our study shows that D-4F, but not apoA-I-containing HDL, hinders tumour growth in mice with inherited breast cancer in association with a higher protection against LDL oxidative modification. PMID:27808249

  8. ApoA-I mimetic administration, but not increased apoA-I-containing HDL, inhibits tumour growth in a mouse model of inherited breast cancer.

    PubMed

    Cedó, Lídia; García-León, Annabel; Baila-Rueda, Lucía; Santos, David; Grijalva, Victor; Martínez-Cignoni, Melanie Raquel; Carbó, José M; Metso, Jari; López-Vilaró, Laura; Zorzano, Antonio; Valledor, Annabel F; Cenarro, Ana; Jauhiainen, Matti; Lerma, Enrique; Fogelman, Alan M; Reddy, Srinivasa T; Escolà-Gil, Joan Carles; Blanco-Vaca, Francisco

    2016-11-03

    Low levels of high-density lipoprotein cholesterol (HDLc) have been associated with breast cancer risk, but several epidemiologic studies have reported contradictory results with regard to the relationship between apolipoprotein (apo) A-I and breast cancer. We aimed to determine the effects of human apoA-I overexpression and administration of specific apoA-I mimetic peptide (D-4F) on tumour progression by using mammary tumour virus-polyoma middle T-antigen transgenic (PyMT) mice as a model of inherited breast cancer. Expression of human apoA-I in the mice did not affect tumour onset and growth in PyMT transgenic mice, despite an increase in the HDLc level. In contrast, D-4F treatment significantly increased tumour latency and inhibited the development of tumours. The effects of D-4F on tumour development were independent of 27-hydroxycholesterol. However, D-4F treatment reduced the plasma oxidized low-density lipoprotein (oxLDL) levels in mice and prevented oxLDL-mediated proliferative response in human breast adenocarcinoma MCF-7 cells. In conclusion, our study shows that D-4F, but not apoA-I-containing HDL, hinders tumour growth in mice with inherited breast cancer in association with a higher protection against LDL oxidative modification.

  9. HDL-apoA-I exchange: rapid detection and association with atherosclerosis.

    PubMed

    Borja, Mark S; Zhao, Lei; Hammerson, Bradley; Tang, Chongren; Yang, Richard; Carson, Nancy; Fernando, Gayani; Liu, Xiaoqin; Budamagunta, Madhu S; Genest, Jacques; Shearer, Gregory C; Duclos, Franck; Oda, Michael N

    2013-01-01

    High density lipoprotein (HDL) cholesterol levels are associated with decreased risk of cardiovascular disease, but not all HDL are functionally equivalent. A primary determinant of HDL functional status is the conformational adaptability of its main protein component, apoA-I, an exchangeable apolipoprotein. Chemical modification of apoA-I, as may occur under conditions of inflammation or diabetes, can severely impair HDL function and is associated with the presence of cardiovascular disease. Chemical modification of apoA-I also impairs its ability to exchange on and off HDL, a critical process in reverse cholesterol transport. In this study, we developed a method using electron paramagnetic resonance spectroscopy (EPR) to quantify HDL-apoA-I exchange. Using this approach, we measured the degree of HDL-apoA-I exchange for HDL isolated from rabbits fed a high fat, high cholesterol diet, as well as human subjects with acute coronary syndrome and metabolic syndrome. We observed that HDL-apoA-I exchange was markedly reduced when atherosclerosis was present, or when the subject carries at least one risk factor of cardiovascular disease. These results show that HDL-apoA-I exchange is a clinically relevant measure of HDL function pertinent to cardiovascular disease.

  10. HDL-apoA-I Exchange: Rapid Detection and Association with Atherosclerosis

    PubMed Central

    Borja, Mark S.; Zhao, Lei; Hammerson, Bradley; Tang, Chongren; Yang, Richard; Carson, Nancy; Fernando, Gayani; Liu, Xiaoqin; Budamagunta, Madhu S.; Genest, Jacques; Shearer, Gregory C.; Duclos, Franck; Oda, Michael N.

    2013-01-01

    High density lipoprotein (HDL) cholesterol levels are associated with decreased risk of cardiovascular disease, but not all HDL are functionally equivalent. A primary determinant of HDL functional status is the conformational adaptability of its main protein component, apoA-I, an exchangeable apolipoprotein. Chemical modification of apoA-I, as may occur under conditions of inflammation or diabetes, can severely impair HDL function and is associated with the presence of cardiovascular disease. Chemical modification of apoA-I also impairs its ability to exchange on and off HDL, a critical process in reverse cholesterol transport. In this study, we developed a method using electron paramagnetic resonance spectroscopy (EPR) to quantify HDL-apoA-I exchange. Using this approach, we measured the degree of HDL-apoA-I exchange for HDL isolated from rabbits fed a high fat, high cholesterol diet, as well as human subjects with acute coronary syndrome and metabolic syndrome. We observed that HDL-apoA-I exchange was markedly reduced when atherosclerosis was present, or when the subject carries at least one risk factor of cardiovascular disease. These results show that HDL-apoA-I exchange is a clinically relevant measure of HDL function pertinent to cardiovascular disease. PMID:24015188

  11. Lysine residues of ABCA1 are required for the interaction with apoA-I.

    PubMed

    Nagao, Kohjiro; Kimura, Yasuhisa; Ueda, Kazumitsu

    2012-03-01

    ATP-binding cassette protein A1 (ABCA1) plays a pivotal role in cholesterol homeostasis by generating high-density lipoprotein (HDL). Apolipoprotein A-I (apoA-I), a lipid acceptor for ABCA1, reportedly interacts with ABCA1. However, it has also been proposed that apoA-I interacts with ABCA1-generated special domains on the plasma membrane, but apart from ABCA1, and solubilizes membrane lipids. To determine the importance of the apoA-I-ABCA1 interaction in HDL formation, the electrostatic interaction between apoA-I and ABCA1, which mediates the interaction between apoB100 in low-density lipoprotein particles (LDL) and LDL receptor, was analyzed. The apoA-I binding to ABCA1 and the cross-linking between them were inhibited by the highly charged molecules heparin and poly-L-lysine. Treating cells with membrane impermeable reagents that specifically react with primary amino groups abolished the interaction between apoA-I and ABCA1. However, these reagents did not affect the characteristic tight ATP binding to ABCA1. These results suggest that lysine residues in the extracellular domains of ABCA1 contribute to the interaction with apoA-I. The electrostatic interaction between ABCA1 and apoA-I is predicted to be the first step in HDL formation. This article is part of a Special Issue entitled Advances in high density lipoprotein formation and metabolism: a tribute to John F. Oram (1945-2010).

  12. Relationship between plasma HDL subclasses distribution and apoA-I gene polymorphisms.

    PubMed

    Jia, Lianqun; Bai, Huai; Fu, Mingde; Xu, Yanhua; Yang, Yuye; Long, Shiyin

    2005-10-01

    It is generally accepted that apolipoprotein (apo) A-I is the dominant structural apolipoprotein of HDL particles and different HDL subclasses have distinct but interrelated metabolic functions. HDL is known to directly affect the atherogenic process hence changes in HDL subclasses distribution may be related to the incidence and prevalence of atherosclerosis. The ApoA-I contents (mg/l) of plasma HDL subclasses were determined by 2-dimensional gel electrophoresis coupled with immunodetection and apoA-I genotypes were assayed by PCR-RFLP in 307 Chinese subjects (169 males, 138 females). The G/G and C/C genotypes were the most frequent at -78 bp and +83 bp of apoA-I gene, respectively. There were no significant differences in the frequencies of rare A allele at -78 bp and rare T allele at +83 bp between males and females. Compared with the G/G carriers, G/A and A/A carriers had significantly higher plasma concentrations of TG, apoC-II, apoC-III, apoA-I contents of prebeta(1)-HDL, HDL(3a) and TG/HDL-C ratio. And in addition, A/A carriers had significantly lower apoA-I contents of HDL(2a) and HDL(2b). Females had increased plasma concentrations of apoA-I, HDL-C, apoA-I contents of HDL(2a) and HDL(2b) while decreased apoA-I contents of prebeta(1)-HDL, HDL(3b) and TG/HDL-C ratio as compared to males carrying the same genotype. No significant differences were demonstrated on the concentrations of plasma lipids, lipoproteins, apolipoproteins and apoA-I contents of plasma HDL subclasses between the C/C and C/T subjects. The G/A polymorphism at -78 bp of apoA-I gene was associated with changes of HDL subclasses distribution. There was a general shift towards smaller-sized HDL, which, in turn, indicated that reverse cholesterol transport (RCT) might be weakened and HDL maturation might be abnormal in the subjects with G/A mutation.

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

    PubMed

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

    2016-09-01

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

  14. Increasing apoA-I production as a target for CHD risk reduction.

    PubMed

    Dullens, Stefan P J; Plat, Jogchum; Mensink, Ronald P

    2007-10-01

    Dyslipidemia leading to coronary heart diseases (CHD) enables venues to prevent or treat CHD by other strategies than only lowering serum LDL cholesterol (LDL-C) concentrations, which is currently the most frequently targeted change. Unlike LDL-C, elevated high-density lipoprotein cholesterol (HDL-C) concentrations may protect against the development of CHD as demonstrated in numerous large-scale epidemiological studies. In this review we describe that besides elevating serum HDL-C concentrations by increasing alpha-HDL particles, approaches to elevate HDL-C concentrations by increasing pre-beta HDL particle concentrations seems more attractive. Besides infusion of apoA-I(Milano), using apoA-I mimetics, or delipidation of alpha-HDL particles, elevating de novo apoA-I production may be a suitable target to functionally increase pre-beta HDL particle concentrations. Therefore, a detailed description of the molecular pathways underlying apoA-I synthesis and secretion, completed with an overview of known effects of pharmacological and nutritional compounds on apoA-I synthesis will be presented. This knowledge may ultimately be applied in developing dietary intervention strategies to elevate apoA-I production and serum HDL-C concentrations and consequently lower CHD risk.

  15. Rosuvastatin 20 mg restores normal HDL-apoA-I kinetics in type 2 diabetes

    PubMed Central

    Vergès, Bruno; Florentin, Emmanuel; Baillot-Rudoni, Sabine; Petit, Jean-Michel; Brindisi, Marie Claude; Pais de Barros, Jean-Paul; Lagrost, Laurent; Gambert, Philippe; Duvillard, Laurence

    2009-01-01

    Catabolism of HDL particles is accelerated in type 2 diabetes, leading to a reduction in plasma residence time, which may be detrimental. Rosuvastatin is the most powerful statin to reduce LDL-cholesterol, but its effects on HDL metabolism in type 2 diabetes remain unknown. We performed a randomized double-blind cross-over trial of 6-week treatment period with placebo or rosuvastatin 20 mg in eight patients with type 2 diabetes. An in vivo kinetic study of HDL-apolipoprotein A-I (apoA-I) with 13C leucine was performed at the end of each treatment period. Moreover, a similar kinetic study was carried out in eight nondiabetic normolipidemic controls. Rosuvastatin significantly reduced plasma LDL-cholesterol (−51%), triglycerides (TGs) (−38%), and HDL-TG (−23%). HDL-apoA-I fractional catabolic rate (FCR) was decreased by rosuvastatin (0.25 ± 0.06 vs. 0.32 ± 0.07 pool/day, P = 0.011), leading to an increase in plasma HDL-apoA-I residence time (4.21 ± 1.02 vs. 3.30 ± 0.73 day, P = 0.011). Treatment with rosuvastatin was associated with a concomitant reduction of HDL-apoA-I production rate. The decrease in HDL-apoA-I FCR, induced by rosuvastatin, was correlated with the reduction of plasma TGs and HDL-TG. HDL apoA-I FCR and production rate values in diabetic patients on rosuvastatin were not different from those found in controls. Rosuvastatin is responsible for a 22% reduction of HDL-apoA-I FCR and restores to normal the increased HDL turnover observed in type 2 diabetes. These kinetic modifications may have beneficial effects by increasing HDL plasma residence time. PMID:19168444

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

    USDA-ARS?s Scientific Manuscript database

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

  17. Extended-release niacin alters the metabolism of plasma apolipoprotein (apo) A-I- and apoB-containing lipoproteins

    PubMed Central

    Lamon-Fava, Stefania; Diffenderfer, Margaret R.; Barrett, P. Hugh R.; Buchsbaum, Aaron; Nyaku, Mawuli; Horvath, Katalin V.; Asztalos, Bela F.; Otokozawa, Seiko; Ai, Masumi; Matthan, Nirupa R.; Lichtenstein, Alice H; Dolnikowski, Gregory G.; Schaefer, Ernst J.

    2009-01-01

    Objectives Extended-release niacin effectively lowers plasma TG levels and raises plasma HDL cholesterol levels, but the mechanisms responsible for these effects are unclear. Methods and Results We examined the effects of extended-release niacin (2 g/d) and extended-release niacin (2 g/d) plus lovastatin (40 mg/d), relative to placebo, on the kinetics of apolipoprotein (apo) A-I and apoA-II in HDL, apoB-100 in TG-rich lipoproteins (TRL), intermediate-density lipoproteins (IDL) and LDL, and apoB-48 in TRL in five men with combined hyperlipidemia. Niacin significantly increased HDL cholesterol and apoA-I concentrations, associated with a significant increase in apoA-I production rate (PR) and no change in fractional catabolic rate (FCR). Plasma TRL apoB-100 levels were significantly lowered by niacin, accompanied by a trend toward an increase in FCR and no change in PR. Niacin treatment significantly increased TRL apoB-48 FCR but had no effect on apoB-48 PR. No effects of niacin on concentrations or kinetic parameters of IDL and LDL apoB-100 and HDL apoA-II were noted. The addition of lovastatin to niacin promoted a lowering in LDL apoB-100 due to increased LDL apoB-100 FCR. Conclusion Niacin treatment was associated with significant increases in HDL apoA-I concentrations and production, as well as enhanced clearance of TRL apoB-100 and apoB-48. PMID:18566298

  18. Increased methionine sulfoxide content of apoA-I in type 1 diabetes.

    PubMed

    Brock, Jonathan W C; Jenkins, Alicia J; Lyons, Timothy J; Klein, Richard L; Yim, Eunsil; Lopes-Virella, Maria; Carter, Rickey E; Thorpe, Suzanne R; Baynes, John W

    2008-04-01

    Cardiovascular disease is a major cause of morbidity and premature mortality in diabetes. HDL plays an important role in limiting vascular damage by removing cholesterol and cholesteryl ester hydroperoxides from oxidized low density lipoprotein and foam cells. Methionine (Met) residues in apolipoprotein A-I (apoA-I), the major apolipoprotein of HDL, reduce peroxides in HDL lipids, forming methionine sulfoxide [Met(O)]. We examined the extent and sites of Met(O) formation in apoA-I of HDL isolated from plasma of healthy control and type 1 diabetic subjects to assess apoA-I exposure to lipid peroxides and the status of oxidative stress in the vascular compartment in diabetes. Three tryptic peptides of apoA-I contain Met residues: Q(84)-M(86)-K(88), W(108)-M(112)-R(116), and L(144)-M(148)-R(149). These peptides and their Met(O) analogs were identified and quantified by mass spectrometry. Relative to controls, Met(O) formation was significantly increased at all three locations (Met(86), Met(112), and Met(148)) in diabetic patients. The increase in Met(O) in the diabetic group did not correlate with other biomarkers of oxidative stress, such as N(epsilon)-malondialdehyde-lysine or N(epsilon)-(carboxymethyl)lysine, in plasma or lipoproteins. The higher Met(O) content in apoA-I from diabetic patients is consistent with increased levels of lipid peroxidation products in plasma in diabetes. Using the methods developed here, future studies can address the relationship between Met(O) in apoA-I and the risk, development, or progression of the vascular complications of diabetes.

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

    PubMed Central

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

    2016-01-01

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

  20. Surface plasmon resonance analysis of the mechanism of binding of apoA-I to high density lipoprotein particles

    PubMed Central

    Lund-Katz, Sissel; Nguyen, David; Dhanasekaran, Padmaja; Kono, Momoe; Nickel, Margaret; Saito, Hiroyuki; Phillips, Michael C.

    2010-01-01

    The partitioning of apolipoprotein A-I (apoA-I) molecules in plasma between HDL-bound and -unbound states is an integral part of HDL metabolism. We used the surface plasmon resonance (SPR) technique to monitor in real time the reversible binding of apoA-I to HDL. Biotinylated human HDL2 and HDL3 were immobilized on a streptavidin-coated SPR sensor chip, and apoA-I solutions at different concentrations were flowed across the surface. The wild-type (WT) human and mouse apoA-I/HDL interaction involves a two-step process; apoA-I initially binds to HDL with fast association and dissociation rates, followed by a step exhibiting slower kinetics. The isolated N-terminal helix bundle domains of human and mouse apoA-I also exhibit a two-step binding process, consistent with the second slower step involving opening of the helix bundle domain. The results of fluorescence experiments with pyrene-labeled apoA-I are consistent with the N-terminal helix bundle domain interacting with proteins resident on the HDL particle surface. Dissociation constants (Kd) measured for WT human apoA-I interactions with HDL2 and HDL3 are about 10 µM, indicating that the binding is low affinity. This Kd value does not apply to all of the apoA-I molecules on the HDL particle but only to a relatively small, labile pool. PMID:19786567

  1. Conformation and Lipid Binding of a C-Terminal (198-243) Peptide of Human Apolipoprotein A-I (apoA-I)†

    PubMed Central

    Zhu, Hongli L.; Atkinson, David

    2008-01-01

    Human apolipoprotein A-I (apoA-I) is the principle apolipoprotein of high-density lipoproteins that are critically involved in reverse cholesterol transport. The intrinsically flexibility of apoA-I has hindered studies of the structural and functional details of the protein. Our strategy is to study peptide models representing different regions of apoA-I. Our previous report on [1-44]apoA-I demonstrated that this N-terminal region is unstructured and folds into ~ 60% α-helix with a moderate lipid binding affinity. We now present details of the conformation and lipid interaction of a C-terminal 46 residue peptide, [198-243]apoA-I, encompassing putative helix repeats 10, 9 and the second half of repeat 8 from the C-terminus of apoA-I. Far ultraviolet circular dichroism spectra show that [198-243] apoA-I is also unfolded in aqueous solution. However, self-association induces ~ 50% α-helix in the peptide. The self-associated peptide exists mainly as a tetramer, as determined by native electrophoresis, cross-linking with glutaraldehyde and unfolding data from circular dichroism (CD) and differential scanning calorimetry (DSC). In the presence of a number of lipid mimicking detergents, above their CMC, ~ 60% α-helix was induced in the peptide. In contrast, SDS, an anionic lipid mimicking detergent, induced helical folding in the peptide at a concentration of ~ 0.003% (~ 100 μM), ~ 70 fold below its typical CMC (0.17–0.23% or 6–8 mM). Both monomeric and tetrameric peptide can solublize dimyristoyl phosphatidyl choline (DMPC) liposomes and fold into ~ 60% α-helix. Fractionation by density gradient ultracentrifugation and visualization by negative staining electromicroscopy, demonstrated that the peptide binds to DMPC with high affinity to form at least two sizes of relatively homogenous discoidal HDL-like particles depending on the initial lipid:peptide ratio. The characteristics (lipid:peptide w/w, diameter and density) of both complexes are similar to those of

  2. Effect of Royal Jelly Intake on Serum Glucose, Apolipoprotein A-I (ApoA-I), Apolipoprotein B (ApoB) and ApoB/ApoA-I Ratios in Patients with Type 2 Diabetes: A Randomized, Double-Blind Clinical Trial Study.

    PubMed

    Khoshpey, Basemeh; Djazayeri, Shima; Amiri, Fatemehsadat; Malek, Mojtaba; Hosseini, Agha Fateme; Hosseini, Sharieh; Shidfar, Shahrzad; Shidfar, Farzad

    2016-08-01

    Type 2 diabetes is the most common metabolic disorder worldwide. Evidence supports a role for royal jelly (RJ) in reduction of serum glucose and lipids in animals and healthy subjects. The purpose of this study was to determine the effect of RJ intake on serum glucose, apolipoprotein A-I (ApoA-I), apolipoprotein B (ApoB) and ApoB/ApoA-I ratios in patients with type 2 diabetes. Fifty patients with type 2 diabetes participated in a double-blind, placebo-controlled study. The participants were randomly divided into RJ and placebo groups and were given doses of 1000 mg royal jelly or placebo 3 times a day for 8 weeks, respectively. Weight, height, fasting blood glucose, ApoA-I and ApoB were measured at baseline and endpoint. There were no significant differences in baseline characteristics and dietary intakes between groups. The mean difference in glucose concentrations decreased in the RJ group (-9.4 mg/dL vs. 4 mg/dL; p=0.011). The mean difference in ApoA-I concentrations increased in the RJ group (34.4 mg/dL vs. -1.08 mg/dL; p=0.013). There was a significant decrease in mean difference of ApoB/ApoA-I in the RJ group compared with the placebo group (0.008 vs. 0.13; p<0.044), respectively. These data suggest that RJ intake may have desirable effects on serum glucose, Apo-A-I concentrations and ApoB/ApoA-I ratios in people with type 2 diabetes. Copyright © 2016 Canadian Diabetes Association. Published by Elsevier Inc. All rights reserved.

  3. Recombinant amyloidogenic domain of ApoA-I: Analysis of its fibrillogenic potential

    SciTech Connect

    Di Gaetano, Sonia; Guglielmi, Fulvio; Arciello, Angela; Mangione, Palma; Monti, Maria; Pagnozzi, Daniela; Raimondi, Sara; Giorgetti, Sofia; Orru, Stefania; Canale, Claudio; Pucci, Piero; Dobson, Christopher M.; Bellotti, Vittorio; Piccoli, Renata . E-mail: piccoli@unina.it

    2006-12-08

    A variety of amyloid diseases are associated with fibrillar aggregates from N-terminal fragments of ApoA-I generated through a largely unexplored multi-step process. The understanding of the molecular mechanism is impaired by the lack of suitable amounts of the fibrillogenic polypeptides that could not be produced by recombinant methods so far. We report the production and the conformational analysis of recombinant ApoA-I 1-93 fragment. Similarly to the polypeptide isolated ex vivo, a pH switch from 7 to 4 induces a fast and reversible conformational transition to a helical state and leads to the identification of a key intermediate in the fibrillogenesis process. Limited proteolysis experiments suggested that the C-terminal region is involved in helix formation. The recombinant polypeptide generates fibrils at pH 4 on a time scale comparable with that of the native fragment. These findings open the way to studies on structural, thermodynamic, and kinetic aspects of ApoA-I fibrillogenesis.

  4. Dysfunctional HDL containing L159R apoA-I leads to exacerbation of atherosclerosis in hyperlipidemic mice

    USDA-ARS?s Scientific Manuscript database

    In this study, the effect of the mutation L159R apoA-I or apoA-IL159R (FIN) was assessed. apoA-IL159R (FIN) is associated with a dominant negative phenotype, displaying hypoalphaproteinemia and an increased risk for atherosclerosis in humans. Transgenic mice lines were created through strategic mati...

  5. Triglyceride enrichment of HDL enhances in vivo metabolic clearance of HDL apo A-I in healthy men

    PubMed Central

    Lamarche, Benoît; Uffelman, Kristine D.; Carpentier, André; Cohn, Jeffrey S.; Steiner, George; Barrett, P. Hugh; Lewis, Gary F.

    1999-01-01

    Triglyceride (TG) enrichment of HDL resulting from cholesteryl ester transfer protein–mediated exchange with TG-rich lipoproteins may enhance the lipolytic transformation and subsequent metabolic clearance of HDL particles in hypertriglyceridemic states. The present study investigates the effect of TG enrichment of HDL on the clearance of HDL-associated apo A-I in humans. HDL was isolated from plasma of six normolipidemic men (mean age: 29.7 ± 2.7 years) in the fasting state and after a five-hour intravenous infusion with a synthetic TG emulsion, Intralipid. Intralipid infusion resulted in a 2.1-fold increase in the TG content of HDL. Each tracer was then whole-labeled with 125I or 131I and injected intravenously into the subject. Apo A-I in TG-enriched HDL was cleared 26% more rapidly than apo A-I in fasting HDL. A strong correlation between the Intralipid-induced increase in the TG content of HDL and the increase in HDL apo A-I fractional catabolic rate reinforced the importance of TG enrichment of HDL in enhancing its metabolic clearance. HDL was separated further into lipoproteins containing apo A-II (LpAI:AII) and those without apo A-II (LpAI). Results revealed that the enhanced clearance of apo A-I from TG-enriched HDL could be largely attributed to differences in the clearance of LpAI but not LpAI:AII. This is, to our knowledge, the first direct demonstration in humans that TG enrichment of HDL enhances the clearance of HDL apo A-I from the circulation. This phenomenon could provide an important mechanism explaining how HDL apo A-I and HDL cholesterol are lowered in hypertriglyceridemic states. PMID:10207171

  6. Apo B/Apo A-I Ratio is Statistically A Better Predictor of Cardiovascular Disease (CVD) than Conventional Lipid Profile: A Study from Kathmandu Valley, Nepal

    PubMed Central

    Tamang, Hem Kumar; Timilsina, Uddhav; Singh, Khelanand Prasad; Shrestha, Sanjit; Raman, Ramendra Kumar; Panta, Pujan; Karna, Preeti; Khadka, Laxmi; Dahal, Chandika

    2014-01-01

    Background: Apo B and Apo A-I, are structural and functional components of lipoprotein particles that serve as transporters of cholesterol. The apo B/apo A-I ratio reflects the cholesterol transport and has been shown to be strongly related to risk of Myocardial infarction, stroke and other Cardiovascular manifestations. Materials and Methods: Forty five participants with Cardiovascular Disease (CVD) and forty four healthy participants were included from different locations of Kathmandu valley, Nepal. Fasting blood samples were collected from ante-cubital vein and serum samples were used for lipid parameters, apo B and apo A-I levels measurement. Results: Statistically significant differences were found for apo B/apo A-I ratio, HDL-c and apo B between the groups. The other lipid parameters and lipid ratios such as total cholesterol, triglyceride, low density lipoprotein, TC/HDL-c, TG/HDL-c and LDL-c/HDL-c were not found to be significant. Conclusion: Apo B/apo A-I ratio seems to have better predictive value than that of classical lipid parameters in cardiovascular risk assessment. PMID:24701475

  7. A novel approach to oral apoA-I mimetic therapy[S

    PubMed Central

    Chattopadhyay, Arnab; Navab, Mohamad; Hough, Greg; Gao, Feng; Meriwether, David; Grijalva, Victor; Springstead, James R.; Palgnachari, Mayakonda N.; Namiri-Kalantari, Ryan; Su, Feng; Van Lenten, Brian J.; Wagner, Alan C.; Anantharamaiah, G. M.; Farias-Eisner, Robin; Reddy, Srinivasa T.; Fogelman, Alan M.

    2013-01-01

    Transgenic tomato plants were constructed with an empty vector (EV) or a vector expressing an apoA-I mimetic peptide, 6F. EV or 6F tomatoes were harvested, lyophilized, ground into powder, added to Western diet (WD) at 2.2% by weight, and fed to LDL receptor-null (LDLR−/−) mice at 45 mg/kg/day 6F. After 13 weeks, the percent of the aorta with lesions was 4.1 ± 4%, 3.3 ± 2.4%, and 1.9 ± 1.4% for WD, WD + EV, and WD + 6F, respectively (WD + 6F vs. WD, P = 0.0134; WD + 6F vs. WD + EV, P = 0.0386; WD + EV vs. WD, not significant). While body weight did not differ, plasma serum amyloid A (SAA), total cholesterol, triglycerides, and lysophosphatidic acid (LPA) levels were less in WD + 6F mice; P < 0.0295. HDL cholesterol and paroxonase-1 activity (PON) were higher in WD + 6F mice (P = 0.0055 and P = 0.0254, respectively), but not in WD + EV mice. Plasma SAA, total cholesterol, triglycerides, LPA, and 15-hydroxyeicosatetraenoic acid (HETE) levels positively correlated with lesions (P < 0.0001); HDL cholesterol and PON were inversely correlated (P < 0.0001). After feeding WD + 6F: i) intact 6F was detected in small intestine (but not in plasma); ii) small intestine LPA was decreased compared with WD + EV (P < 0.0469); and iii) small intestine LPA 18:2 positively correlated with the percent of the aorta with lesions (P < 0.0179). These data suggest that 6F acts in the small intestine and provides a novel approach to oral apoA-I mimetic therapy. PMID:23378594

  8. Different Functional and Structural Characteristics between ApoA-I and ApoA-4 in Lipid-Free and Reconstituted HDL State: ApoA-4 Showed Less Anti-Atherogenic Activity

    PubMed Central

    Yoo, Jeong-Ah; Lee, Eun-Young; Park, Ji Yoon; Lee, Seung-Taek; Ham, Sihyun; Cho, Kyung-Hyun

    2015-01-01

    Apolipoprotein A-I and A-IV are protein constituents of high-density lipoproteins although their functional difference in lipoprotein metabolism is still unclear. To compare anti-atherogenic properties between apoA-I and apoA-4, we characterized both proteins in lipid-free and lipid-bound state. In lipid-free state, apoA4 showed two distinct bands, around 78 and 67 Å on native gel electrophoresis, while apoA-I showed scattered band pattern less than 71 Å. In reconstituted HDL (rHDL) state, apoA-4 showed three major bands around 101 Å and 113 Å, while apoA-I-rHDL showed almost single band around 98 Å size. Lipid-free apoA-I showed 2.9-fold higher phospholipid binding ability than apoA-4. In lipid-free state, BS3-crosslinking revealed that apoA-4 showed less multimerization tendency upto dimer, while apoA-I showed pentamerization. In rHDL state (95:1), apoA-4 was existed as dimer as like as apoA-I. With higher phospholipid content (255:1), five apoA-I and three apoA-4 were required to the bigger rHDL formation. Regardless of particle size, apoA-I-rHDL showed superior LCAT activation ability than apoA-4-rHDL. Uptake of acetylated LDL was inhibited by apoA-I in both lipid-free and lipid-bound state, while apoA-4 inhibited it only lipid-free state. ApoA-4 showed less anti-atherogenic activity with more sensitivity to glycation. In conclusion, apoA-4 showed inferior physiological functions in lipid-bound state, compared with those of apoA-I, to induce more pro-atherosclerotic properties. PMID:25997739

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

    PubMed

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

    2011-05-01

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

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

    PubMed Central

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

    2011-01-01

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

  11. HDL-C / apoA-I ] : a multi-vessel cardiometabolic risk marker in women with T2DM.

    PubMed

    Hermans, Michel P; Valensi, Paul; Ahn, Sylvie A; Rousseau, Michel F

    2017-09-15

    Although women have higher HDL-C than men, their HDL particles are also prone to become small, dense and dysfunctional in case of T2DM. To assess the vascular risk related to HDLs of different sizes/densities without direct measurement, we adjusted HDL-C to its main apolipoprotein (apoA-I), as [HDL-C/apoA-I]. This ratio estimates HDLs size and provides indices as to their number, cholesterol load, and density. We stratified 280 Caucasian T2DM women according to [HDL-C/apoA-I] quartiles (Q), to determine how it segregates cardiometabolic risk, β-cell function, glycemic control, and vascular complications. Five parameters were derived from combined determination of HDL-C and apoA-I : HDL size; HDL number; cholesterol load per particle (pP); apoA-IpP; and HDL density. An adverse cardiometabolic profile characterized Q-I and Q-II patients, whose HDLs were denser and apoA-I-depleted, whereas Q-III patients had HDLs with characteristics closer to controls. Q-IV patients had HDLs of supernormal size/composition and a more favorable phenotype in terms of fat distribution; insulin sensitivity (64% vs 41%), metabolic syndrome, β-cell function (32% vs 23%); exogenous insulin (44 vs 89 U/day), and glycemic control (HbA1c: 56 vs 61 mmol/mol), associated with lower prevalence of micro-/macrovascular complications: all-cause microangiopathy 47% vs 61%; retinopathy 22% vs 34%; all-cause macroangiopathy 19% vs 31%; and CAD: 6% vs 24% (p<0.05). [HDL-C/apoA-I] can stratify T2DM women according to metabolic phenotype, macrovascular and coronary damage, β-cell function, microangiopathic risk, and retinopathy. This ratio is a versatile and readily available marker of cardiometabolic status and vascular complications in T2DM women. This article is protected by copyright. All rights reserved.

  12. Adeno-associated virus serotype 8 ApoA-I gene transfer reduces progression of atherosclerosis in ApoE-KO mice: comparison of intramuscular and intravenous administration.

    PubMed

    Cimmino, Giovanni; Giannarelli, Chiara; Chen, Wei; Alique, Matilde; Santos-Gallego, Carlos G; Fuster, Valentin; Hajjar, Roger J; Walsh, Christopher E; Badimon, Juan J

    2011-03-01

    Apolipoprotein A-I (ApoA-I)/high-density lipoprotein (HDL)-raising treatments are effective antiatherosclerotic strategies. We have compared the antiatherogenic effects of human ApoA-I (hApoA-I) overexpression by intraportal and intramuscular gene transfer in atherosclerotic ApoE-knockout mice. Atherosclerotic lesions were induced by atherogenic diet. After atherosclerosis induction, a group of animals was killed and served as atherosclerosis baseline-control group. The remaining animals were randomized into the following groups: (1) atherosclerosis-progression-control, (2) intraportal/vector administration, and (3) intramuscular/vector administration. Aortas and hearts were processed for atherosclerotic quantification by en face Sudan IV and Oil Red-O, respectively. Liver and muscle specimens were processed for protein/gene expression analysis. A sustained increase in hApoA-I/HDL plasma levels was observed in both transduced groups. hApoA-I overexpression abolished plaque progression versus progression-control group. hApoA-I overexpression significantly reduced lesion macrophage, feature indicative of plaque stabilization. Scavenger receptor class-B type I (SR-BI), but not ATP-binding cassette, sub-family A (ABCA), member 1 (ABCA-1), was significantly upregulated in treated groups versus progression-controls. The results of this study show a similar effect of hApoA-I/HDL overexpression on plaque progression/stabilization by 2 different routes of administration. Our results showing similar effects using either intramuscular administration and intraportal route of administration may have significant clinical implications, given the reduced medical risk to patient and cost of intramuscular injections.

  13. Natural human apoA-I mutations L141RPisa and L159RFIN alter HDL structure and functionality and promote atherosclerosis development in mice.

    PubMed

    Tiniakou, Ioanna; Kanaki, Zoi; Georgopoulos, Spiros; Chroni, Angeliki; Van Eck, Miranda; Fotakis, Panagiotis; Zannis, Vassilis I; Kardassis, Dimitris

    2015-11-01

    Mutations in human apolipoprotein A-I (apoA-I) are associated with low high-density lipoprotein (HDL) cholesterol levels and pathological conditions such as premature atherosclerosis and amyloidosis. In this study we functionally characterized two natural human apoA-I mutations, L141RPisa and L159RFIN, in vivo. We generated transgenic mice expressing either wild-type (WT) or the two mutant forms of human apoA-I on a mouse apoA-I(-/-) background and analyzed for abnormalities in their lipid and lipoprotein profiles. HDL structure and functionality, as well as atherosclerosis development following a 14-week high-fat diet were assessed in these mice. The expression of either apoA-I mutant was associated with markedly reduced serum apoA-I (<10% of WT apoA-I), total and HDL-cholesterol levels (∼20% and ∼7% of WT apoA-I, respectively) and the formation of few small size HDL particles with preβ2 and α3, α4 electrophoretic mobility. HDL particles containing either of the two apoA-I mutants exhibited attenuated anti-oxidative properties as indicated by their inability to prevent low-density lipoprotein oxidation, and by decreased activities of paraoxonase-1 and platelet-activating factor acetylhydrolase. However, the apoA-I(L141R)Pisa or apoA-I(L159R)FIN-containing HDL particles demonstrated increased capacity to promote ATP-Binding Cassette Transporter A1-mediated cholesterol efflux from macrophages. Expression of apoA-I(L141R)Pisa or apoA-I(L159R)FIN mutations in mice was associated with increased diet-induced atherosclerosis compared to either WT apoA-I transgenic or apoA-I(-/-) mice. These findings suggest that natural apoA-I mutations L141RPisa and L159RFIN affect the biogenesis and the functionality of HDL in vivo and predispose to diet-induced atherosclerosis in the absence of any other genetic defect. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  14. Role of urea on recombinant Apo A-I stability and its utilization in anion exchange chromatography.

    PubMed

    Angarita, Monica; Arosio, Paolo; Müller-Späth, Thomas; Baur, Daniel; Falkenstein, Roberto; Kuhne, Wolfgang; Morbidelli, Massimo

    2014-08-08

    Apolipoprotein A-I (Apo A-I) is an important lipid-binding protein involved in the transport and metabolism of cholesterol. High protein purity, in particular with respect to endotoxins is required for therapeutic applications. The use of urea during the purification process of recombinant Apo A-I produced in Escherichia coli has been suggested so as to provide high endotoxin clearance. In this work, we show that urea can be used as a sole modifier during the ion exchange chromatographic purification of Apo A-I and we investigate the molecular mechanism of elution by correlating the effect of urea on self-association, conformation and adsorption equilibrium properties of a modified model Apo A-I. In the absence of urea the protein was found to be present as a population of oligomers represented mainly by trimers, hexamers and nonamers. The addition of urea induced oligomer dissociation and protein structure unfolding. We correlated the changes in protein association and conformation with variations of the adsorption equilibrium of the protein on a strong anion exchanger. It was confirmed that the adsorption isotherms, described by a Langmuir model, were dependent on both protein and urea concentrations. Monomers, observed at low urea concentration (0.5M), were characterized by larger binding affinity and adsorption capacity compared to both protein oligomers (0M) and unfolded monomers (2-8M). The reduction of both the binding strength and maximum adsorption capacity at urea concentrations larger than 0.5M explains the ability of urea of inducing elution of the protein from the ion exchange resin. The dissociation of the protein complexes occurring during the elution could likely be the origin of the effective clearance of endotoxins originally trapped inside the oligomers.

  15. Macrophage apolipoprotein A-I expression protects against atherosclerosis in ApoE-deficient mice and up-regulates ABC transporters.

    PubMed

    Su, Yan Ru; Ishiguro, Hiroyuki; Major, Amy S; Dove, Dwayne E; Zhang, Wenwu; Hasty, Alyssa H; Babaev, Vladimir R; Linton, MacRae F; Fazio, Sergio

    2003-10-01

    The antiatherogenic effect of high-density lipoprotein (HDL) and its major protein component apolipoprotein A-I (apoA-I) has been largely attributed to their key roles in reverse cholesterol transport (RCT) and cellular cholesterol efflux. Substantial evidence shows that overexpression of human apoA-I reduces atherosclerosis in animal models. However, it is uncertain whether this protection is due to an increase in plasma HDL level or to a local effect in the artery wall. To test the hypothesis that expression of human apoA-I in macrophages can promote RCT in the artery wall, we used a retroviral construct expressing human apoA-I cDNA (MFG-HAI) to transduce ApoE(-/-) bone marrow cells and then transplanted these cells into ApoE(-/-) mice with preexisting atherosclerosis. ApoE(-/-) mice reconstituted with MFG-HAI marrow had a significant reduction (30%) in atherosclerotic lesions in the proximal aorta compared to control mice that received marrow expressing MFG parental virus. Peritoneal macrophages isolated from MFG-HAI mice showed a four- to fivefold increase in mRNA expression levels of both ATP-binding cassette (ABC) A1 and ABCG1 compared to controls. Our data demonstrate that gene transfer-mediated expression of human apoA-I in macrophages can compensate in part for apoE deficiency and delay the progression of atherosclerotic lesions by stimulating ABC-dependent cholesterol efflux and RCT.

  16. Ecto-F1-ATPase: A moonlighting protein complex and an unexpected apoA-I receptor

    PubMed Central

    Vantourout, Pierre; Radojkovic, Claudia; Lichtenstein, Laeticia; Pons, Véronique; Champagne, Eric; Martinez, Laurent O

    2010-01-01

    Mitochondrial ATP synthase has been recently detected at the surface of different cell types, where it is a high affinity receptor for apoA-I, the major protein component in high density lipoproteins (HDL). Cell surface ATP synthase (namely ecto-F1-ATPase) expression is related to different biological effects, such as regulation of HDL uptake by hepatocytes, endothelial cell proliferation or antitumor activity of Vγ9/Vδ2 T lymphocytes. This paper reviews the recently discovered functions and regulations of ecto-F1-ATPase. Particularly, the role of the F1-ATPase pathway(s) in HDL-cholesterol uptake and apoA-I-mediated endothelial protection suggests its potential importance in reverse cholesterol transport and its regulation might represent a potential therapeutic target for HDL-related therapy for cardiovascular diseases. Therefore, it is timely for us to better understand how this ecto-enzyme and downstream pathways are regulated and to develop pharmacologic interventions. PMID:21157968

  17. Dietary fat elevates hepatic apoA-I production by increasing the fraction of apolipoprotein A-I mRNA in the translating pool.

    PubMed

    Azrolan, N; Odaka, H; Breslow, J L; Fisher, E A

    1995-08-25

    Elevated plasma high density lipoprotein cholesterol (HDL-C) levels are associated with a decreased risk for coronary heart disease. Ironically, diets enriched in saturated fat and cholesterol (HF/HC diets), which tend to accelerate atherosclerotic processes by increasing LDL cholesterol levels, also raise HDL-C. We have recently reported, using a human apoA-I (hapoA-1) transgenic mouse model, that the elevation of HDL-C by a HF/HC diet is attributable, in part, to an increase in the hepatic production of hapoA-1. To further define the hepatocellular processes associated with this induction, we have prepared primary hepatocytes from hapoA-1 transgenic mice. Rates of hapoA-1 secretion were 40% greater from cells prepared from animals fed the HF/HC relative to a low fat-low cholesterol (LF/LC) control diet. The abundance of hapoA-1 mRNA in these cells was similar between hepatocytes prepared from the HF/HC and LF/LC diet fed animals, suggesting a post-transcriptional mechanism that does not involve mRNA stability. Inhibition of secretion using brefeldin A revealed an increase in cellular hapoA-1 accumulation. Thus, the HF/HC diet apparently affects hepatic hapoA-1 production via a mechanism that is manifest prior to the exit of newly synthesized hapoA-1 from the Golgi. Pulse-chase experiments revealed a 39% greater peak hapoA-1 synthesis, with no difference in the degradation of total labeled hapoA-1 protein, as a result of the HF/HC diet feeding. Finally, resolution of liver S10 extracts via sucrose density sedimentation and metrizamide density equilibrium gradient centrifugation analyses both revealed similar increases (31 and 24%, respectively) in the relative percentage of hapoA-1 mRNA associated with the translating polysomal fractions as a result of the HF/HC feeding. Together, these data suggest that the HF/HC diet affects hepatic hapoA-1 production via a specific modulation in the relative amount of hapoA-1 mRNA in the polysomal pool. These observations

  18. Increased HDL cholesterol and apoA-I in humans and mice treated with a novel SR-BI inhibitor.

    PubMed

    Masson, David; Koseki, Masahiro; Ishibashi, Minako; Larson, Christopher J; Miller, Stephen G; King, Bernard D; Tall, Alan R

    2009-12-01

    Increasing HDL levels is a potential strategy for the treatment of atherosclerosis. ITX5061, a molecule initially characterized as a p38 MAPK inhibitor, increased HDL-C levels by 20% in a human population of hypertriglyceridemic subjects with low HDL levels. ITX5061 also moderately increased apoA-I but did not affect VLDL/LDL cholesterol or plasma triglyceride concentrations. ITX5061 increased HDL-C in WT and human apoA-I transgenic mice, and kinetic experiments showed that ITX5061 decreased the fractional catabolic rate of HDL-CE and reduced its hepatic uptake. In transfected cells, ITX5061 inhibited SR-BI-dependent uptake of HDL-CE. Moreover, ITX5061 failed to increase HDL-C levels in SR-BI(-/-) mice. To assess effects on atherosclerosis, ITX5061 was given to atherogenic diet-fed Ldlr(+/-) mice with or without CETP expression for 18 weeks. In both the control and CETP-expressing groups, ITX5061-treated mice displayed reductions of early atherosclerotic lesions in the aortic arch -40%, P<0.05), and a nonsignificant trend to reduced lesion area in the proximal aorta. Our data indicate that ITX5061 increases HDL-C levels by inhibition of SR-BI activity. This suggests that pharmacological inhibition of SR-BI has the potential to raise HDL-C and apoA-I levels without adverse effects on VLDL/LDL cholesterol levels in humans.

  19. FAMP, a novel apoA-I mimetic peptide, suppresses aortic plaque formation through promotion of biological HDL function in ApoE-deficient mice.

    PubMed

    Uehara, Yoshinari; Ando, Setsuko; Yahiro, Eiji; Oniki, Kosuke; Ayaori, Makoto; Abe, Satomi; Kawachi, Emi; Zhang, Bo; Shioi, Seijiro; Tanigawa, Hiroyuki; Imaizumi, Satoshi; Miura, Shin-Ichiro; Saku, Keijiro

    2013-05-24

    Apolipoprotein (apo) A-I is a major high-density lipoprotein (HDL) protein that causes cholesterol efflux from peripheral cells through the ATP-binding cassette transporter A1 (ABCA1), thus generating HDL and reversing the macrophage foam cell phenotype. Pre-β1 HDL is the smallest subfraction of HDL, which is believed to represent newly formed HDL, and it is the most active acceptor of free cholesterol. Furthermore it has a possible protective function against cardiovascular disease (CVD). We developed a novel apoA-I mimetic peptide without phospholipids (Fukuoka University ApoA-I Mimetic Peptide, FAMP). FAMP type 5 (FAMP5) had a high capacity for cholesterol efflux from A172 cells and mouse and human macrophages in vitro, and the efflux was mainly dependent on ABCA1 transporter. Incubation of FAMP5 with human HDL or whole plasma generated small HDL particles, and charged apoA-I-rich particles migrated as pre-β HDL on agarose gel electrophoresis. Sixteen weeks of treatment with FAMP5 significantly suppressed aortic plaque formation (scrambled FAMP, 31.3 ± 8.9% versus high-dose FAMP5, 16.2 ± 5.0%; P<0.01) and plasma C-reactive protein and monocyte chemoattractant protein-1 in apoE-deficient mice fed a high-fat diet. In addition, it significantly enhanced HDL-mediated cholesterol efflux capacity from the mice. A newly developed apoA-I mimetic peptide, FAMP, has an antiatherosclerotic effect through the enhancement of the biological function of HDL. FAMP may have significant atheroprotective potential and prove to be a new therapeutic tool for CVD.

  20. ApoA-I Mimetic Peptide 4F Rescues Pulmonary Hypertension by Inducing MicroRNA-193-3p

    PubMed Central

    Sharma, Salil; Umar, Soban; Potus, Francois; Iorga, Andrea; Wong, Gabriel; Meriwether, David; Breuils-Bonnet, Sandra; Mai, Denise; Navab, Kaveh; Ross, David; Navab, Mohamad; Provencher, Steeve; Fogelman, Alan M.; Bonnet, Sébastien; Reddy, Srinivasa T.; Eghbali, Mansoureh

    2014-01-01

    Background Pulmonary Arterial Hypertension (PAH) is a chronic lung disease associated with severe pulmonary vascular changes. A pathogenic role of oxidized lipids such as hydroxyeicosatetraenoic acids (HETEs) and hydroxyoctadecadienoic acids (HODEs) is well established in vascular disease. Apolipoprotein A-I (apoA-I) mimetic peptides including 4F have been reported to reduce levels of these oxidized lipids and improve vascular disease. However, the role of oxidized lipids in the progression of PAH and the therapeutic action of 4F in PAH is not well established. Methods and Results We studied two different rodent models of Pulmonary Hypertension (PH); a monocrotaline (MCT) rat model and a hypoxia mouse model. Plasma levels of HETEs and HODEs were significantly elevated in PH. 4F treatment reduced these levels and rescued pre-existing PH in both models. MicroRNA analysis revealed that miR193-3p (miR193) was significantly downregulated in the lung tissue and in serum from both PAH patients and in PH rodents. In-vivo miR193 overexpression in the lungs rescued pre-existing PH and resulted in downregulation of lipoxygenases and insulin-like growth factor-1 receptor. 4F restored PH-induced miR193 expression via transcription factor retinoid X receptor alpha (RXRα). Conclusions These studies establish the importance of microRNAs as downstream effectors of an apoA-I mimetic peptide in the rescue of PH and suggest that treatment with apoA-I mimetic peptides, or miR193 may have therapeutic value. PMID:24963038

  1. Development of a method to measure preβHDL and αHDL apoA-I enrichment for stable isotopic studies of HDL kinetics.

    PubMed

    Li, Xuefei; Stolinski, Michael; Umpleby, A Margot

    2012-10-01

    Our understanding of HDL metabolism would be enhanced by the measurement of the kinetics of preβHDL, the nascent form of HDL, since elevated levels have been reported in patients with coronary artery disease. Stable isotope methodology is an established technique that has enabled the determination of the kinetics (production and catabolism) of total HDL apoA-I in vivo. The development of separation procedures to obtain a preβHDL fraction, the isotopic enrichment of which could then be measured, would enable further understanding of the pathways in vivo for determining the fate of preβHDL and the formation of αHDL. A method was developed and optimised to separate and measure preβHDL and αHDL apoA-I enrichment. Agarose gel electrophoresis was first used to separate lipoprotein subclasses, and then a 4-10 % discontinuous SDS-PAGE used to isolate apoA-I. Measures of preβHDL enrichment in six healthy subjects were undertaken following an infusion of L-[1-¹³C-leucine]. After isolation of preβ and αHDL, the isotopic enrichment of apoA-I for each fraction was measured by gas chromatography-mass spectrometry. PreβHDL apoA-I enrichment was measured with a CV of 0.51 % and αHDL apoA-I with a CV of 0.34 %. The fractional catabolic rate (FCR) of preβHDL apoA-I was significantly higher than the FCR of αHDL apoA-I (p < 0.005). This methodology can be used to selectively isolate preβ and αHDL apoA-I for the measurement of apoA-I isotopic enrichment for kinetics studies of HDL subclass metabolism in a research setting.

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

    PubMed

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

    2015-01-01

    We report a novel heterozygous apolipoprotein A-I (apoA-I) missense mutation (c.517C>A, p.Arg149Ser, designated as apoA-IBoston) in a 67-year-old woman and her 2 sons, who had mean serum high-density lipoprotein (HDL) cholesterol, apoA-I, and apoA-I in very large α-1 HDL that were 10%, 35%, and 16% of normal, respectively (all P < .05). The percentage of HDL cholesterol in the esterified form was also significantly (P < .05) reduced to 52% of control values. Cholesteryl ester tranfer protein (CETP) activity was normal. The mean global, adenosine triphosphate (ATP)-binding cassette transporter A1 and scavenger receptor B type I-mediated cellular cholesterol efflux capacity in apoB-depleted serum from affected family members were 41%, 37%, 47%, 54%, and 48% of control values, respectively (all P < .05). lecithin-cholesterol acyltransferase (LCAT) activity in plasma was 71% of controls, whereas in the cell-based assay, it was 73% of control values (P < .05). The data indicate that this novel apoA-I missense is associated with markedly decreased levels of HDL cholesterol and very large α-1 HDL, as well as decreased serum cellular cholesterol efflux and LCAT activity, but not with premature coronary heart disease, similar to other apoA-I mutations that have been associated with decreased LCAT activity. Copyright © 2015 National Lipid Association. Published by Elsevier Inc. All rights reserved.

  3. PEGylated helper-dependent adenoviral vector expressing human Apo A-I for gene therapy in LDLR-deficient mice.

    PubMed

    Leggiero, E; Astone, D; Cerullo, V; Lombardo, B; Mazzaccara, C; Labruna, G; Sacchetti, L; Salvatore, F; Croyle, M; Pastore, L

    2013-12-01

    Helper-dependent adenoviral (HD-Ad) vectors have great potential for gene therapy applications; however, their administration induces acute toxicity that impairs safe clinical applications. We previously observed that PEGylation of HD-Ad vectors strongly reduces the acute response in murine and primate models. To evaluate whether PEGylated HD-Ad vectors combine reduced toxicity with the correction of pathological phenotypes, we administered an HD-Ad vector expressing the human apolipoprotein A-I (hApoA-I) to low-density lipoprotein (LDL)-receptor-deficient mice (a model for familial hypercholesterolemia) fed a high-cholesterol diet. Mice were treated with high doses of HD-Ad-expressing apo A-I or its PEGylated version. Twelve weeks later, LDL levels were lower and high-density lipoprotein (HDL) levels higher in mice treated with either of the vectors than in untreated mice. After terminal killing, the areas of atherosclerotic plaques were much smaller in the vector-treated mice than in the control animals. Moreover, the increase in pro-inflammatory cytokines was lower and consequently the toxicity profile better in mice treated with PEGylated vector than in mice treated with the unmodified vector. This finding indicates that the reduction in toxicity resulting from PEGylation of HD-Ad vectors does not impair the correction of pathological phenotypes. It also supports the clinical potential of these vectors for the correction of genetic diseases.

  4. Induction of fatal inflammation in LDL receptor and ApoA-I double-knockout mice fed dietary fat and cholesterol.

    PubMed

    Zabalawi, Manal; Bhat, Shaila; Loughlin, Tara; Thomas, Michael J; Alexander, Eric; Cline, Mark; Bullock, Bill; Willingham, Mark; Sorci-Thomas, Mary G

    2003-09-01

    Atherogenic response to dietary fat and cholesterol challenge was evaluated in mice lacking both the LDL receptor (LDLr(-/-)) and apoA-I (apoA-I(-/-)) gene, LDLr(-/-)/apoA-I(-/-) or double-knockout mice. Gender- and age-matched LDLr(-/-)/apoA-I(-/-) mice were fed a diet consisting of 0.1% cholesterol and 10% palm oil for 16 weeks and compared to LDLr(-/-) mice or single-knockout mice. The LDLr(-/-) mice showed a 6- to 7-fold increase in total plasma cholesterol (TPC) compared to their chow-fed mice counterparts, while LDLr(-/-)/apoA-I(-/-) mice showed only a 2- to 3-fold increase in TPC compared to their chow-fed controls. This differential response to the atherogenic diet was unanticipated, since chow-fed LDLr(-/-) and LDLr(-/-)/apoA-I(-/-) mice began the study with similar LDL levels and differed primarily in their HDL concentration. The 6-fold diet-induced increase in TPC observed in the LDLr(-/-) mice occurred mainly in VLDL/LDL and not in HDL. Mid-study plasma samples taken after 8 weeks of diet feeding showed that LDLr(-/-) mice had TPC concentrations approximately 60% of their 16-week level, while the LDLr(-/-)/apoA-I(-/-) mice had reached 100% of their 16-week TPC concentration after only 8 weeks of diet. Male LDLr(-/-) mice showed similar aortic cholesterol levels to male LDLr(-/-)/apoA-I(-/-) mice despite a 4-fold higher VLDL/LDL concentration in the LDLr(-/-) mice. A direct comparison of the severity of aortic atherosclerosis between female LDLr(-/-) and LDLr(-/-)/apoA-I(-/-) mice was compromised due to the loss of female LDLr(-/-)/apoA-I(-/-) mice between 10 and 14 weeks into the study. Diet-fed female and, with time, male LDLr(-/-)/apoA-I(-/-) mice suffered from severe ulcerated cutaneous xanthomatosis. This condition, combined with a complete depletion of adrenal cholesterol, manifested in fatal wasting of the affected mice. In conclusion, LDLr(-/-) and LDLr(-/-)/apoA-I(-/-) mice showed dramatic TPC differences in response to dietary fat and

  5. Effect of pressure and ionic strength on the self-association of Apo-A-I from the human high density lipoprotein complex.

    PubMed

    Formisano, S; Brewer, H B; Osborne, J C

    1978-01-25

    The self-association of apo-A-I isolated from the human high density lipoprotein complex has been investigated by gel permeation chromatography and sedimentation equilibrium. The apparent weight average molecular weight (MWapp) versus Apo-A-I concentration profile was found to be sensitive to ionic strength and pressure; MWapp increased with increasing ionic strength and decreasing rotor speed. The data were consistent with a monomer-dimer-tetrameroctamer association shceme over all conditions investigated if a change in the partial specific volume of apo-A-I upon association of 5.5 x 10(-2) ml/g is postulated.

  6. RVX 208: A novel BET protein inhibitor, role as an inducer of apo A-I/HDL and beyond.

    PubMed

    Ghosh, Gopal C; Bhadra, Rajarshi; Ghosh, Raktim K; Banerjee, Kinjal; Gupta, Anjan

    2017-08-01

    Low-density cholesterol (LDL) has been the prime target of currently available lipid-lowering therapies although current research is expanding the focus beyond LDL lowering and has included high-density cholesterol (HDL) also as the target. Bromo and extra-terminal (BET) proteins are implicated in the regulation of transcription of several regulatory genes and regulation of proinflammatory pathways. As atherosclerosis is an inflammatory pathway and studies showed that BET inhibition has a role in inhibiting inflammation, the concept of BET inhibition came in the field of atherosclerosis. RVX 208 is a novel, orally active, BET protein inhibitor and the only BET inhibitor currently available in the field of atherosclerosis. RVX 208 acts primarily by increasing apo A-I (apolipoprotein A-I) and HDL levels. RVX 208 has a novel action of increasing larger, more cardio-protective HDL particles. Post hoc analysis of Phase II trials also showed that RVX 208 reduced major adverse cardiovascular events (MACE) in treated patients, over and above that of apo A-I/HDL increasing action. This MACE reducing actions of RVX 208 were largely due to its novel anti-inflammatory actions. Currently, a phase III trial, BETonMACE, is recruiting patients to look for the effects of RVX 208 in patients with increased risk of atherosclerotic cardiovascular disease. So BET inhibitors act in multiple ways to inhibit and modulate atherosclerosis and would be an emerging and potential option in the management of multifactorial disease like coronary artery disease by inhibiting a single substrate. But we need long-term phase III trial data's to look for effects on real-world patients. © 2017 John Wiley & Sons Ltd.

  7. ApoA-I enhances generation of HDL-like lipoproteins through interaction between ABCA1 and phospholipase Cγ in rat astrocytes.

    PubMed

    Ito, Jin-ichi; Nagayasu, Yuko; Kheirollah, Alireza; Abe-Dohmae, Sumiko; Yokoyama, Shinji

    2011-12-01

    In the previous paper, we reported that apolipoprotein (apo) A-I enhances generation of HDL-like lipoproteins in rat astrocytes to be accompanied with both increase in tyrosine phosphorylation of phospholipase Cγ (PL-Cγ) and PL-Cγ translocation to cytosolic lipid-protein particles (CLPP) fraction. In this paper, we studied the interaction between apoA-I and ATP-binding cassette transporter A1 (ABCA1) to relate with PL-Cγ function for generation of HDL-like lipoproteins in the apoA-I-stimulated astrocytes. ABCA1 co-migrated with exogenous apoA-I with apparent molecular weight over 260kDa on SDS-PAGE when rat astrocytes were treated with apoA-I and then with a cross-linker, BS3. The solubilized ABCA1 of rat astrocytes was associated with the apoA-I-immobilized Affi-Gel 15. An LXR agonist, To901317, increased the cellular level of ABCA1, association of apoA-I with ABCA1 and apoA-I-mediated lipid release in rat astrocytoma GA-1/Mock cells where ABCA1 expression at baseline is very low. PL-Cγ was co-isolated by apoA-I-immobilized Affi-Gel 15 and co-immunoprecipitated by anti-ABCA1 antibody along with ABCA1 from the solubilized membrane fraction of rat astrocytes. The SiRNA of ABCA1 suppressed not only the PL-Cγ binding to ABCA1 but also the tyrosine phosphorylation of PL-Cγ. A PL-C inhibitor, U73122, prevented generation of apoA-I-mediated HDL-like lipoproteins in rat astrocytes. To901317 increased the association of PL-Cγ with ABCA1 in GA-1/Mock cells dependently on the increase of cellular level of ABCA1 without changing that of PL-Cγ. These findings suggest that the exogenous apoA-I augments the interaction between PL-Cγ and ABCA1 to stimulate tyrosine phosphorylation and activation of PL-Cγ for generation of HDL-like lipoproteins in astrocytes.

  8. ApoA-I induces S1P release from endothelial cells through ABCA1 and SR-BI in a positive feedback manner.

    PubMed

    Liu, Xing; Ren, Kun; Suo, Rong; Xiong, Sheng-Lin; Zhang, Qing-Hai; Mo, Zhong-Cheng; Tang, Zhen-Li; Jiang, Yue; Peng, Xiao-Shan; Yi, Guang-Hui

    2016-12-01

    Sphingosine-1-phosphate (S1P), which has emerged as a pivotal signaling mediator that participates in the regulation of multiple cellular processes, is derived from various cells, including vascular endothelial cells. S1P accumulates in lipoproteins, especially HDL, and the majority of free plasma S1P is bound to HDL. We hypothesized that HDL-associated S1P is released through mechanisms associated with the HDL maturation process. ApoA-I, a major HDL apolipoprotein, is a critical factor for nascent HDL formation and lipid trafficking via ABCA1. Moreover, apoA-I is capable of promoting bidirectional lipid movement through SR-BI. In the present study, we confirmed that apoA-I can facilitate the production and release of S1P by HUVECs. Furthermore, we demonstrated that ERK1/2 and SphK activation induced by apoA-I is involved in the release of S1P from HUVECs. Inhibitor and siRNA experiments showed that ABCA1 and SR-BI are required for S1P release and ERK1/2 phosphorylation induced by apoA-I. However, the effects triggered by apoA-I were not suppressed by inhibiting ABCA1/JAK2 or the SR-BI/Src pathway. S1P released due to apoA-I activation can stimulate the (ERK1/2)/SphK1 pathway through S1PR (S1P receptor) 1/3. These results indicated that apoA-I not only promotes S1P release through ABCA1 and SR-BI but also indirectly activates the (ERK1/2)/SphK1 pathway by releasing S1P to trigger their receptors. In conclusion, we suggest that release of S1P induced by apoA-I from endothelial cells through ABCA1 and SR-BI is a self-positive-feedback process: apoA-I-(ABCA1 and SR-BI)-(S1P release)-S1PR-ERK1/2-SphK1-(S1P production)-(more S1P release induced by apoA-I).

  9. Comparison of Apolipoprotein (apoB/apoA-I) and Lipoprotein (Total Cholesterol/HDL) Ratio Determinants. Focus on Obesity, Diet and Alcohol Intake

    PubMed Central

    Tognon, Gianluca; Berg, Christina; Mehlig, Kirsten; Thelle, Dag; Strandhagen, Elisabeth; Gustavsson, Jaana; Rosengren, Annika; Lissner, Lauren

    2012-01-01

    The ratio between apolipoprotein B and apolipoprotein A-I (apoB/apoA-I) has been suggested to be a powerful and more accurate predictor of future cardiovascular disease risk than total cholesterol and HDL cholesterol. Since diet and lifestyle can directly influence dyslipidemia, it is of interest to identify modifiable factors that are associated with high levels of the apolipoprotein ratio and if they can have a different association with a more traditional indicator of cardiovascular risk such as total cholesterol/HDL. The relationship between obesity and dyslipidemia is established and it is of interest to determine which factors can modify this association. This study investigated the cross-sectional association of obesity, diet and lifestyle factors with apoB/apoA-I and total cholesterol/HDL respectively, in a Swedish population of 2,907 subjects (1,537 women) as part of the INTERGENE study. The apolipoprotein and lipoprotein ratios were highly correlated, particularly in women, and obesity was strongly associated with both. Additionally, age, cigarette smoking and alcohol intake were important determinants of these ratios. Alcohol was the only dietary factor that appreciably attenuated the association between obesity and each of the ratios, with a stronger attenuation in women. Other dietary intake and lifestyle-related factors such as smoking status and physical activity had a lower effect on this association. Because the apolipoprotein and lipoprotein ratios share similar diet and lifestyle determinants as well as being highly correlated, we conclude that either of these ratios may be a sufficient indicator of dyslipidemia. PMID:22848405

  10. The Application of Multiple Reaction Monitoring to Assess Apo A-I Methionine Oxidations in Diabetes and Cardiovascular Disease

    PubMed Central

    Yassine, Hussein N.; Jackson, Angela M.; Reaven, Peter D.; Nedelkov, Dobrin; Nelson, Randall W.; Lau, Serrine S.; Borchers, Christoph H.

    2014-01-01

    The oxidative modification of apolipoprotein A-I ‘s methionine148(M148) is associated with defective HDL function in vitro. Multiple Reaction Monitoring (MRM) is a mass spectrometric technique that can be used to quantitate post-translational modifications. In this study, we developed an MRM assay to monitor the abundance ratio of the peptide containing oxidized M148 to the native peptide in Apo A-I. Measurement of the oxidized-to-unoxidized-M148 ratio was reproducible (CV<5%). The extent of methionine M148 oxidation in the HDL of healthy controls, and type 2 diabetic participants with and without prior cardiovascular events (CVD) were then examined. The results suggest a significant increase in the relative ratio of the peptide containing oxidized M148 to the unmodified peptide in the HDL of participants with diabetes and CVD (p<0.001), compared to participants without CVD. Monitoring the abundance ratio of the peptides containing oxidized and unoxidized M148 by MRM provides a means of examining the relationship between M148 oxidation and vascular complications in CVD. PMID:25705587

  11. Safety and Tolerability of CSL112, a Reconstituted, Infusible, Plasma-Derived Apolipoprotein A-I, After Acute Myocardial Infarction: The AEGIS-I Trial (ApoA-I Event Reducing in Ischemic Syndromes I).

    PubMed

    Michael Gibson, C; Korjian, Serge; Tricoci, Pierluigi; Daaboul, Yazan; Yee, Megan; Jain, Purva; Alexander, John H; Steg, P Gabriel; Lincoff, A Michael; Kastelein, John J P; Mehran, Roxana; D'Andrea, Denise M; Deckelbaum, Lawrence I; Merkely, Bela; Zarebinski, Maciej; Ophuis, Ton Oude; Harrington, Robert A

    2016-12-13

    Human or recombinant apolipoprotein A-I (apoA-I) has been shown to increase high-density lipoprotein-mediated cholesterol efflux capacity and to regress atherosclerotic disease in animal and clinical studies. CSL112 is an infusible, plasma-derived apoA-I that has been studied in normal subjects or those with stable coronary artery disease. This study aimed to characterize the safety, tolerability, pharmacokinetics, and pharmacodynamics of CSL112 in patients with a recent acute myocardial infarction. The AEGIS-I trial (Apo-I Event Reducing in Ischemic Syndromes I) was a multicenter, randomized, double-blind, placebo-controlled, dose-ranging phase 2b trial. Patients with myocardial infarction were stratified by renal function and randomized 1:1:1 to CSL112 (2 g apoA-I per dose) and high-dose CSL112 (6 g apoA-I per dose), or placebo for 4 consecutive weekly infusions. Coprimary safety end points were occurrence of either a hepatic safety event (an increase in alanine transaminase >3 times the upper limit of normal or an increase in total bilirubin >2 times the upper limit of normal) or a renal safety event (an increase in serum creatinine >1.5 times the baseline value or a new requirement for renal replacement therapy). A total of 1258 patients were randomized, and 91.2% received all 4 infusions. The difference in incidence rates for an increase in alanine transaminase or total bilirubin between both CSL112 arms and placebo was within the protocol-defined noninferiority margin of 4%. Similarly, the difference in incidence rates for an increase in serum creatinine or a new requirement for renal replacement therapy was within the protocol-defined noninferiority margin of 5%. CSL112 was associated with increases in apoA-I and ex vivo cholesterol efflux similar to that achieved in patients with stable coronary artery disease. In regard to the secondary efficacy end point, the risk for the composite of major adverse cardiovascular events among the groups was similar. Among

  12. Homocysteine is a determinant of ApoA-I and both are associated with ankle brachial index, in an ambulatory elderly population.

    PubMed

    Guéant-Rodriguez, Rosa Maria; Spada, Rosario; Moreno-Garcia, Maira; Anello, Guido; Bosco, Paolo; Lagrost, Laurent; Romano, Antonino; Elia, Maurizio; Guéant, Jean-Louis

    2011-02-01

    The ankle brachial index (ABI) is an indicator of lower extremity peripheral arterial disease (PAD) and a predictor of atherothrombosis. ApoA-I and HDL are associated with PAD, in humans. Homocysteine influences the liver expression of ApoA-I and decreases its blood level and HDL in genetic mice models. We aimed therefore to evaluate whether homocysteine and its nutritional determinants, folate and vitamin B12 are associated with ABI by influencing HDL metabolism, in an ambulatory elderly population. 667 elderly volunteers from rural Sicily were assessed for ABI, homocysteine and its determinants, lipid markers and other predictors of PAD. HDL size was assessed in 15 sera in upper and lower quartiles of Hcy distribution. In multivariate analysis, ApoA-I and homocysteine were two predictors of ABI (β-coefficient = 2.86, P<0.004 and β-coefficient = -3.41, P<0.001, respectively). Homocysteine correlated negatively with ApoA-I (R = -0.147, P<0.001) and with HDL-Cholesterol (R = -0.113, P = 0.003). The associations of homocysteine, vitamin B12 and methylmalonic acid with ApoA-I and HDL2a particles and that of homocysteine with increased small size HDL3c suggested mechanisms related with impaired synthesis of ApoA-I and HDL and abnormal maturation of HDL particles. The influence of homocysteine on ApoA-I and HDL metabolism provides new insights on its role on vascular diseases, at a cross-point between atherosclerosis and atherothrombosis. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  13. Automation of PRM-dependent D3-Leu tracer enrichment in HDL to study the metabolism of apoA-I, LCAT and other apolipoproteins.

    PubMed

    Lee, Lang Ho; Andraski, Allison B; Pieper, Brett; Higashi, Hideyuki; Sacks, Frank M; Aikawa, Masanori; Singh, Sasha A

    2017-01-01

    We developed an automated quantification workflow for PRM-enabled detection of D3-Leu labeled apoA-I in high-density lipoprotein (HDL) isolated from humans. Subjects received a bolus injection of D3-Leu and blood was drawn at eight time points over three days. HDL was isolated and separated into six size fractions for subsequent proteolysis and PRM analysis for the detection of D3-Leu signal from ∼0.03 to 0.6% enrichment. We implemented an intensity-based quantification approach that takes advantage of high-resolution/accurate mass PRM scans to identify the D3-Leu 2HM3 ion from non-specific peaks. Our workflow includes five modules for extracting the targeted PRM peak intensities (XPIs): Peak centroiding, noise removal, fragment ion matching using Δm/z windows, nine intensity quantification options, and validation and visualization outputs. We optimized the XPI workflow using in vitro synthesized and clinical samples of D0/D3-Leu labeled apoA-I. Three subjects' apoA-I enrichment curves in six HDL size fractions, and LCAT, apoA-II and apoE from two size fractions were generated within a few hours. Our PRM strategy and automated quantification workflow will expedite the turnaround of HDL apoA-I metabolism data in clinical studies that aim to understand and treat the mechanisms behind dyslipidemia.

  14. Comparative Effects of Diet-Induced Lipid Lowering Versus Lipid Lowering Along With Apo A-I Milano Gene Therapy on Regression of Atherosclerosis.

    PubMed

    Wang, Lai; Tian, Fang; Arias, Ana; Yang, Mingjie; Sharifi, Behrooz G; Shah, Prediman K

    2016-05-01

    Apolipoprotein A-1 (Apo A-I) Milano, a naturally occurring Arg173to Cys mutant of Apo A-1, has been shown to reduce atherosclerosis in animal models and in a small phase 2 human trial. We have shown the superior atheroprotective effects of Apo A-I Milano (Apo A-IM) gene compared to wild-type Apo A-I gene using transplantation of retrovirally transduced bone marrow in Apo A-I/Apo E null mice. In this study, we compared the effect of dietary lipid lowering versus lipid lowering plus Apo A-IM gene transfer using recombinant adeno-associated virus (rAAV) 8 as vectors on atherosclerosis regression in Apo A-I/Apo E null mice. All mice were fed a high-cholesterol diet from age of 6 weeks until week 20, and at 20 weeks, 10 mice were euthanized to determine the extent of atherosclerosis. After 20 weeks, an additional 20 mice were placed on either a low-cholesterol diet plus empty rAAV (n = 10) to serve as controls or low-cholesterol diet plus 1 single intravenous injection of 1.2 × 10(12)vector genomes of adeno-associated virus (AAV) 8 vectors expressing Apo A-IM (n = 10). At the 40 week time point, intravenous AAV8 Apo A-IM recipients showed a significant regression of atherosclerosis in the whole aorta (P< .01), aortic sinuses (P< .05), and brachiocephalic arteries (P< .05) compared to 20-week-old mice, whereas low-cholesterol diet plus empty vector control group showed no significant regression in lesion size. Immunostaining showed that compared to the 20-week-old mice, there was a significantly reduced macrophage content in the brachiocephalic (P< .05) and aortic sinus plaques (P< .05) of AAV8 Apo A-IM recipients. These data show that although dietary-mediated cholesterol lowering halts progression of atherosclerosis, it does not induce regression, whereas combination of low-cholesterol diet and AAV8 mediated Apo A-I Milano gene therapy induces rapid and significant regression of atherosclerosis in mice. These data provide support for the potential feasibility of this

  15. Increased HDL Size and Enhanced Apo A-I Catabolic Rates Are Associated With Doxorubicin-Induced Proteinuria in New Zealand White Rabbits.

    PubMed

    López-Olmos, Victoria; Carreón-Torres, Elizabeth; Luna-Luna, María; Flores-Castillo, Cristobal; Martínez-Ramírez, Miriam; Bautista-Pérez, Rocío; Franco, Martha; Sandoval-Zárate, Julio; Roldán, Francisco-Javier; Aranda-Fraustro, Alberto; Soria-Castro, Elizabeth; Muñoz-Vega, Mónica; Fragoso, José-Manuel; Vargas-Alarcón, Gilberto; Pérez-Méndez, Oscar

    2016-03-01

    The catabolism and structure of high-density lipoproteins (HDL) may be the determining factor of their atheroprotective properties. To better understand the role of the kidney in HDL catabolism, here we characterized HDL subclasses and the catabolic rates of apo A-I in a rabbit model of proteinuria. Proteinuria was induced by intravenous administration of doxorubicin in New Zealand white rabbits (n = 10). HDL size and HDL subclass lipids were assessed by electrophoresis of the isolated lipoproteins. The catabolic rate of HDL-apo A-I was evaluated by exogenous radiolabelling with iodine-131. Doxorubicin induced significant proteinuria after 4 weeks (4.47 ± 0.55 vs. 0.30 ± 0.02 g/L of protein in urine, P < 0.001) associated with increased uremia, creatininemia, and cardiotoxicity. Large HDL2b augmented significantly during proteinuria, whereas small HDL3b and HDL3c decreased compared to basal conditions. HDL2b, HDL2a, and HDL3a subclasses were enriched with triacylglycerols in proteinuric animals as determined by the triacylglycerol-to-phospholipid ratio; the cholesterol content in HDL subclasses remained unchanged. The fractional catabolic rate (FCR) of [(131)I]-apo A-I in the proteinuric rabbits was faster (FCR = 0.036 h(-1)) compared to control rabbits group (FCR = 0.026 h(-1), P < 0.05). Apo E increased and apo A-I decreased in HDL, whereas PON-1 activity increased in proteinuric rabbits. Proteinuria was associated with an increased number of large HDL2b particles and a decreased number of small HDL3b and 3c. Proteinuria was also connected to an alteration in HDL subclass lipids, apolipoprotein content of HDL, high paraoxonase-1 activity, and a rise in the fractional catabolic rate of the [(131)I]-apo A-I.

  16. The Carboxy-Terminal Region of apoA-I is Required for the ABCA1-Dependent Formation of α-HDL but not preβ-HDL Particles In Vivo

    PubMed Central

    Chroni, Angeliki; Koukos, Georgios; Duka, Adelina; Zannis, Vassilis I.

    2008-01-01

    ABCA1-mediated lipid efflux to lipid poor apoA-I results in the gradual lipidation of apoA-I. This leads to the formation of discoidal HDL which are subsequently converted to spherical HDL by the action of LCAT. We have investigated the effect of point mutations and deletions in the carboxy-terminal region of apoA-I on the biogenesis of HDL using adenovirus-mediated gene transfer in apoA-I deficient mice. It was found that the plasma HDL levels were greatly reduced in mice expressing the carboxy-terminal deletion mutants apoA-I[Δ(185-243)] and apoA-I[Δ(220-243)], shown previously to diminish the ABCA1-mediated lipid efflux. The HDL levels were normal in mice expressing the WT apoA-I, the apoA-I[Δ(232-243)] deletion mutant or the apoA-I[E191A/H193A/K195A] point mutant, which promote normal ABCA1-mediated lipid efflux. Electron microscopy and two-dimensional gel electrophoresis showed that the apoA-I[Δ(185-243)] and apoA-I[Δ(220-243)] mutants formed mainly preβ-HDL particles and few spherical particles enriched in apoE, while WT apoA-I, apoA-I[Δ(232-243)] and apoA-I[E191A/H193A/K195A] formed spherical α-HDL particles. The findings establish that a) deletions that eliminate the 220-231 region of apoA-I prevent the synthesis of α-HDL, but allow the synthesis of preβ-HDL particles in vivo, b) the amino-terminal segment 1-184 of apoA-I can promote synthesis of preβ-HDL type particles in an ABCA1-independent process and c) the charged residues in the 191-195 region of apoA-I do not influence the biogenesis of HDL. PMID:17447731

  17. Selective HDL-Raising Human Apo A-I Gene Therapy Counteracts Cardiac Hypertrophy, Reduces Myocardial Fibrosis, and Improves Cardiac Function in Mice with Chronic Pressure Overload.

    PubMed

    Amin, Ruhul; Muthuramu, Ilayaraja; Aboumsallem, Joseph Pierre; Mishra, Mudit; Jacobs, Frank; De Geest, Bart

    2017-09-20

    Epidemiological studies support an independent inverse association between high-density lipoprotein (HDL) cholesterol levels and heart failure incidence. The effect of selective HDL-raising adeno-associated viral serotype 8-human apolipoprotein (apo) A-I (AAV8-A-I) gene transfer on cardiac remodeling induced by transverse aortic constriction (TAC) was evaluated in C57BL/6 low-density lipoprotein receptor-deficient mice. Septal wall thickness and cardiomyocyte cross-sectional area were reduced by 16.5% (p < 0.001) and by 13.8% (p < 0.01), respectively, eight weeks after TAC in AAV8-A-I mice (n = 24) compared to control mice (n = 39). Myocardial capillary density was 1.11-fold (p < 0.05) higher and interstitial cardiac fibrosis was 45.3% (p < 0.001) lower in AAV8-A-I TAC mice than in control TAC mice. Lung weight and atrial weight were significantly increased in control TAC mice compared to control sham mice, but were not increased in AAV8-A-I TAC mice. The peak rate of isovolumetric contraction was 1.19-fold (p < 0.01) higher in AAV8-A-I TAC mice (n = 17) than in control TAC mice (n = 29). Diastolic function was also significantly enhanced in AAV8-A-I TAC mice compared to control TAC mice. Nitro-oxidative stress and apoptosis were significantly reduced in the myocardium of AAV8-A-I TAC mice compared to control TAC mice. In conclusion, selective HDL-raising human apo A-I gene transfer potently counteracts the development of pressure overload-induced cardiomyopathy.

  18. ApoM/HDL-C and apoM/apoA-I ratios are indicators of diabetic nephropathy in healthy controls and type 2 diabetes mellitus.

    PubMed

    Zhang, Puhong; Gao, Jialin; Pu, Chun; Feng, Gang; Wang, Lizhuo; Huang, Lizhu; Zhang, Yao

    2017-03-01

    Apolipoprotein M (apoM) concentrations were decreased in type 2 diabetes mellitus (T2DM). ApoM was selectively expressed in renal tubular epithelial cells. We investigated the changes in plasma apoM concentrations in diabetic nephropathy (DN) patients and the potential of apoM as a biomarker of DN. A total of 96 DN patients and 100 age- and sex-matched diabetic non-nephropathy (non-DN) patients and 110 healthy controls were included. All T2DM patients were divided into 3 groups according to urinary albumin excretion: normoalbuminuria (n=100), microalbuminuria (n=50) and macroalbuminuria (n=46). Plasma apoM concentrations were measured by enzyme-linked immunosorbent assay. DN Patients had higher plasma apoM concentrations than those in non-DN patients (22.23±11.69 vs. 18.96±7.85ng/μl, P<0.05). In addition, microalbuminuria group showed higher plasma apoM concentrations than those in normoalbuminuria group (22.67±11.40 vs. 18.96±7.85ng/μl, P<0.05). The areas under curve (AUC) of apoM using a receiver-operating characteristic (ROC) curve analysis showed that plasma apoM concentrations were not indicators for identification of DN from healthy people (AUC=0.478, P=0.585) and from T2DM (AUC=0.563, P=0.125). DN patients had higher ratios of apoM/HDL-C and apoM/apoA1 than those in healthy controls and in non-DN patients. ApoM/HDL-C and apoM/apoA1 ratios could be used as indicators for identification of DN from healthy people (AUC=0.597, P=0.016; AUC=0.665, P=0.000, respectively) and from T2DM (AUC=0.580, P=0.050; AUC=0.601, P=0.015, respectively). ApoM/HDL-C and apoM/apoA1 ratios could be used as indicators for identification of DN from healthy people and from T2DM patients. Copyright © 2017. Published by Elsevier B.V.

  19. Effects of Iron Supplementation With and Without Docosahexaenoic Acid on the Cardiovascular Disease Risk Based on Paraoxonase-1, hs-CRP, and ApoB/ApoA-I Ratio in Women with Iron Deficiency Anemia.

    PubMed

    Shidfar, Farzad; Amani, Samira; Vafa, Mohammadreza; Shekarriz, Ramin; Hosseini, Sharieh; Shidfar, Shahrzad; Eshraghian, Mohammadreza; Mousavi, Seyedeh Neda

    2016-01-01

    Numerous studies have demonstrated that tissue deposition of iron following prolonged high dose of oral supplementation for treatment of iron deficiency anemia (IDA) leads to body iron overload and oxidative stress, which starts the process of atherosclerosis. This study aimed to determine the effect of iron supplementation in combination with docosahexaenoic acid (DHA) on the cardiovascular disease risk based on paraoxonase-1 (PON-1), high-sensitivity C-reactive protein (hs-CRP), and ApoB/ApoA-I ratio in women with IDA. In this randomized controlled trial, 76 women with IDA, aged 15-45 years, were included. The patients were randomly assigned to receive 500 mg of DHA supplement or placebo with an iron tablet, once daily for 12 weeks. The participants were assessed by measurement of the serum iron, ferritin, PON-1, hs-CRP levels, and the ApoB/ApoA-I ratio at the beginning and end of study. Serum hs-CRP decreased in the DHA-supplemented group (p = 0.036), and ApoA-I decreased in the placebo group (p = 0.013). No significant difference was detected for the serum PON-1 concentration and the ApoB/ApoA-I ratio in two groups. Iron supplementation combined with DHA may have favorable effects on serum hs-CRP in women with IDA.

  20. Effects of blackberry (Morus nigra L.) consumption on serum concentration of lipoproteins, apo A-I, apo B, and high-sensitivity-C-reactive protein and blood pressure in dyslipidemic patients

    PubMed Central

    Aghababaee, Sahar Keshtkar; Vafa, Mohammadreza; Shidfar, Farzad; Tahavorgar, Atefeh; Gohari, Mahmoodreza; Katebi, Davod; Mohammadi, Vida

    2015-01-01

    Background: This study investigated blackberry (Persian mulberry) effects on apo A-I, apo B, high-sensitivity-C-reactive protein (hs-CRP), and systolic blood pressure (SBP) and diastolic blood pressure (DBP) in dyslipidemic patients. Materials and Methods: In this 8-week randomized clinical trial, 72 dyslipidemic patients were randomly divided into two groups: Intervention (300 mL/day blackberry juice with pulp) and control group (usual diets). Before and after the intervention, fasting blood samples were taken from both groups and serum concentration of lipoprotein, apo A-I and apo B, serum lipids (total cholesterol, low-density lipoprotein, high-density lipoprotein [HDL], and triglyceride), hs-CRP were measured. Blood pressure before and after the study was measured with a mercury manometer. Results: At week 8 in the intervention group, apo A-I and HDL increased significantly (P = 0.015, P = 0.001, respectively), apo B and hs-CRP decreased significantly (P = 0.044, P = 0.04, respectively). Mean changes in apo A-I and HDL and apo B/apo A-I ratio were significant between the groups (P = 0.005, P = 0.014, and P = 0.009, respectively). After 8 weeks, there was a significant difference between hs-CRP mean values (P = 0.01) of the groups. At week 8, SBP decreased significantly (P = 0.005) in the intervention group with no significant differences for SBP mean values between the groups. No significant changes were observed in other lipid parameters and DBP in the intervention group and between the groups. Conclusion: Blackberry consumption may exert beneficial effects on apolipoproteins, blood pressure, and inflammatory markers in individuals with lipid disorders. PMID:26622259

  1. Studies in mice, hamsters, and rats demonstrate that repression of hepatic apoA-I expression by taurocholic acid in mice is not mediated by the farnesoid-X-receptor

    PubMed Central

    Gardès, Christophe; Blum, Denise; Bleicher, Konrad; Chaput, Evelyne; Ebeling, Martin; Hartman, Peter; Handschin, Corinne; Richter, Hans; Benson, G. Martin

    2011-01-01

    It is claimed that apoA-I expression is repressed in mice by cholic acid (CA) and its taurine conjugate, taurocholic acid (TCA) via farnesoid X receptor (FXR) activation. We measured apoA-I expression in mice, hamsters, and rats treated with highly potent and selective synthetic FXR agonists or with TCA. All of the synthetic agonists bound to FXR with high affinity in a scintillation proximity assay. However, TCA did not compete with the radioligand up to the highest concentration used (100 μM). The C-site regulatory region of apoA-I, through which FXR has been reported to regulate its expression, is completely conserved across the species investigated. In both male and female human apoA-I-transgenic mice, we reproduced the previously reported strong inhibition of human apoA-I expression upon treatment with the typical supraphysiological dose of TCA used in such studies. However, in contrast to some previous reports, TCA did not repress murine apoA-I expression in the same mice. Also, more-potent and -selective FXR agonists did not affect human or murine apoA-I expression in this model. In LDL receptor-deficient mice and Golden Syrian hamsters, selective FXR agonists did not affect apoA-I expression, whereas in Wistar rats, some even increased apoA-I expression. In conclusion, selective FXR agonists do not repress apoA-I expression in rodents. Repression of human apoA-I expression by TCA in transgenic mice is probably mediated through FXR-independent mechanisms. PMID:21464203

  2. apo B gene knockout in mice results in embryonic lethality in homozygotes and neural tube defects, male infertility, and reduced HDL cholesterol ester and apo A-I transport rates in heterozygotes.

    PubMed Central

    Huang, L S; Voyiaziakis, E; Markenson, D F; Sokol, K A; Hayek, T; Breslow, J L

    1995-01-01

    apo B is a structural constituent of several classes of lipoprotein particles, including chylomicrons, VLDL, and LDL. To better understand the role of apo B in the body, we have used gene targeting in embryonic stem cells to create a null apo B allele in the mouse. Homozygous apo B deficiency led to embryonic lethality, with resorption of all embryos by gestational day 9. Heterozygotes showed an increased tendency to intrauterine death with some fetuses having incomplete neural tube closure and some live-born heterozygotes developing hydrocephalus. The majority of male heterozygotes were sterile, although the genitourinary system and sperm were grossly normal. Viable heterozygotes had normal triglycerides, but total, LDL, and HDL cholesterol levels were decreased by 37, 37, and 39%, respectively. Hepatic and intestinal apo B mRNA levels were decreased in heterozygotes, presumably contributing to the decreased LDL levels through decreased synthesis of apo B-containing lipoproteins. Kinetic studies indicated that heterozygotes had decreased transport rates of HDL cholesterol ester and apo A-I. As liver and intestinal apo A-I mRNA levels were unchanged, the mechanism for decreased apo A-I transport must be posttranscriptional. Heterozygotes also had normal cholesterol absorption and a normal response of the plasma lipoprotein pattern to chronic consumption of a high fat, high cholesterol, Western-type diet. In summary, we report a mouse model for apo B deficiency with several phenotypic features that were unexpected based on clinical studies of apo B-deficient humans, such as embryonic lethality in homozygotes and neural tube closure defects, male infertility, and a major defect in HDL production in heterozygotes. This model presents an opportunity to study the mechanisms underlying these phenotypic changes. Images PMID:7593600

  3. ApoA-I/SR-BI modulates S1P/S1PR2-mediated inflammation through the PI3K/Akt signaling pathway in HUVECs.

    PubMed

    Ren, Kun; Lu, Yan-Ju; Mo, Zhong-Cheng; -Liu, Xing; Tang, Zhen-Li; Jiang, Yue; Peng, Xiao-Shan; Li, Li; Zhang, Qing-Hai; Yi, Guang-Hui

    2017-02-08

    Endothelial dysfunction plays a vital role during the initial stage of atherosclerosis. Oxidized low-density lipoprotein (ox-LDL) induces vascular endothelial injury and vessel wall inflammation. Sphingosine-1-phosphate (S1P) exerts numerous vasoprotective effects by binding to diverse S1P receptors (S1PRs; S1PR1-5). A number of studies have shown that in endothelial cells (ECs), S1PR2 acts as a pro-atherosclerotic mediator by stimulating vessel wall inflammation through the phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway. Scavenger receptor class B member I (SR-BI), a high-affinity receptor for apolipoprotein A-I (apoA-I)/high-density lipoprotein (HDL), inhibits nuclear factor-κB (NF-κB) translocation and decreases the plasma levels of inflammatory mediators via the PI3K/Akt pathway. We hypothesized that the inflammatory effects of S1P/S1PR2 on ECs may be regulated by apoA-I/SR-BI. The results showed that ox-LDL, a pro-inflammatory factor, augmented the S1PR2 level in human umbilical vein endothelial cells (HUVECs) in a dose- and time-dependent manner. In addition, S1P/S1PR2 signaling influenced the levels of inflammatory factors, including tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and IL-10, aggravating inflammation in HUVECs. Moreover, the pro-inflammatory effects induced by S1P/S1PR2 were attenuated by SR-BI overexpression and enhanced by an SR-BI inhibitor, BLT-1. Further experiments showed that the PI3K/Akt signaling pathway was involved in this process. Taken together, these results demonstrate that apoA-I/SR-BI negatively regulates S1P/S1PR2-mediated inflammation in HUVECs by activating the PI3K/Akt signaling pathway.

  4. Effect of open-label infusion of an apoA-I-containing particle (CER-001) on RCT and artery wall thickness in patients with FHA.

    PubMed

    Kootte, Ruud S; Smits, Loek P; van der Valk, Fleur M; Dasseux, Jean-Louis; Keyserling, Constance H; Barbaras, Ronald; Paolini, John F; Santos, Raul D; van Dijk, Theo H; Dallinga-van Thie, Geesje M; Nederveen, Aart J; Mulder, Willem J M; Hovingh, G Kees; Kastelein, John J P; Groen, Albert K; Stroes, Erik S

    2015-03-01

    Reverse cholesterol transport (RCT) contributes to the anti-atherogenic effects of HDL. Patients with the orphan disease, familial hypoalphalipoproteinemia (FHA), are characterized by decreased tissue cholesterol removal and an increased atherogenic burden. We performed an open-label uncontrolled proof-of-concept study to evaluate the effect of infusions with a human apoA-I-containing HDL-mimetic particle (CER-001) on RCT and the arterial vessel wall in FHA. Subjects received 20 infusions of CER-001 (8 mg/kg) during 6 months. Efficacy was assessed by measuring (apo)lipoproteins, plasma-mediated cellular cholesterol efflux, fecal sterol excretion (FSE), and carotid artery wall dimension by MRI and artery wall inflammation by (18)F-fluorodeoxyglucose-positron emission tomography/computed tomography scans. We included seven FHA patients: HDL-cholesterol (HDL-c), 13.8 [1.8-29.1] mg/dl; apoA-I, 28.7 [7.9-59.1] mg/dl. Following nine infusions in 1 month, apoA-I and HDL-c increased directly after infusion by 27.0 and 16.1 mg/dl (P = 0.018). CER-001 induced a 44% relative increase (P = 0.018) in in vitro cellular cholesterol efflux with a trend toward increased FSE (P = 0.068). After nine infusions of CER-001, carotid mean vessel wall area decreased compared with baseline from 25.0 to 22.8 mm(2) (P = 0.043) and target-to-background ratio from 2.04 to 1.81 (P = 0.046). In FHA-subjects, CER-001 stimulates cholesterol mobilization and reduces artery wall dimension and inflammation, supporting further evaluation of CER-001 in FHA patients. Copyright © 2015 by the American Society for Biochemistry and Molecular Biology, Inc.

  5. Effect of open-label infusion of an apoA-I-containing particle (CER-001) on RCT and artery wall thickness in patients with FHA[S

    PubMed Central

    Kootte, Ruud S.; Smits, Loek P.; van der Valk, Fleur M.; Dasseux, Jean-Louis; Keyserling, Constance H.; Barbaras, Ronald; Paolini, John F.; Santos, Raul D.; van Dijk, Theo H.; Dallinga-van Thie, Geesje M.; Nederveen, Aart J.; Mulder, Willem J. M.; Hovingh, G. Kees; Kastelein, John J. P.; Groen, Albert K.; Stroes, Erik S.

    2015-01-01

    Reverse cholesterol transport (RCT) contributes to the anti-atherogenic effects of HDL. Patients with the orphan disease, familial hypoalphalipoproteinemia (FHA), are characterized by decreased tissue cholesterol removal and an increased atherogenic burden. We performed an open-label uncontrolled proof-of-concept study to evaluate the effect of infusions with a human apoA-I-containing HDL-mimetic particle (CER-001) on RCT and the arterial vessel wall in FHA. Subjects received 20 infusions of CER-001 (8 mg/kg) during 6 months. Efficacy was assessed by measuring (apo)lipoproteins, plasma-mediated cellular cholesterol efflux, fecal sterol excretion (FSE), and carotid artery wall dimension by MRI and artery wall inflammation by 18F-fluorodeoxyglucose-positron emission tomography/computed tomography scans. We included seven FHA patients: HDL-cholesterol (HDL-c), 13.8 [1.8–29.1] mg/dl; apoA-I, 28.7 [7.9–59.1] mg/dl. Following nine infusions in 1 month, apoA-I and HDL-c increased directly after infusion by 27.0 and 16.1 mg/dl (P = 0.018). CER-001 induced a 44% relative increase (P = 0.018) in in vitro cellular cholesterol efflux with a trend toward increased FSE (P = 0.068). After nine infusions of CER-001, carotid mean vessel wall area decreased compared with baseline from 25.0 to 22.8 mm2 (P = 0.043) and target-to-background ratio from 2.04 to 1.81 (P = 0.046). In FHA-subjects, CER-001 stimulates cholesterol mobilization and reduces artery wall dimension and inflammation, supporting further evaluation of CER-001 in FHA patients. PMID:25561459

  6. Opposite regulation of human versus mouse apolipoprotein A-I by fibrates in human apolipoprotein A-I transgenic mice.

    PubMed Central

    Berthou, L; Duverger, N; Emmanuel, F; Langouët, S; Auwerx, J; Guillouzo, A; Fruchart, J C; Rubin, E; Denèfle, P; Staels, B; Branellec, D

    1996-01-01

    The regulation of liver apolipoprotein (apo) A-I gene expression by fibrates was studied in human apo A-I transgenic mice containing a human genomic DNA fragment driving apo A-I expression in liver. Treatment with fenofibrate (0.5% wt/wt) for 7 d increased plasma human apo A-I levels up to 750% and HDL-cholesterol levels up to 200% with a shift to larger particles. The increase in human apo A-I plasma levels was time and dose dependent and was already evident after 3 d at the highest dose (0.5% wt/wt) of fenofibrate. In contrast, plasma mouse apo A-I concentration was decreased after fenofibrate in nontransgenic mice. The increase in plasma human apo A-I levels after fenofibrate treatment was associated with a 97% increase in hepatic human apo A-I mRNA, whereas mouse apo A-I mRNA levels decreased to 51%. In nontransgenic mice, a similar down-regulation of hepatic apo A-I mRNA levels was observed. Nuclear run-on experiments demonstrated that the increase in human apo A-I and the decrease in mouse apo A-I gene expression after fenofibrate occurred at the transcriptional level. Since part of the effects of fibrates are mediated through the nuclear receptor PPAR (peroxisome proliferator-activated receptor), the expression of the acyl CoA oxidase (ACO) gene was measured as a control of PPAR activation. Both in transgenic and nontransgenic mice, fenofibrate induced ACO mRNA levels up to sixfold. When transgenic mice were treated with gemfibrozil (0.5% wt/wt) plasma human apo A-I and HDL-cholesterol levels increased 32 and 73%, respectively, above control levels. The weaker effect of this compound on human apo A-I and HDL-cholesterol levels correlated with a less pronounced impact on ACO mRNA levels (a threefold increase) suggesting that the level of induction of human apo A-I gene is related to the PPAR activating potency of the fibrate used. Treatment of human primary hepatocytes with fenofibric acid (500 microM) provoked an 83 and 50% increase in apo A-I secretion and

  7. Mitochondrial function is involved in regulation of cholesterol efflux to apolipoprotein (apo)A-I from murine RAW 264.7 macrophages.

    PubMed

    Allen, Anne Marie; Graham, Annette

    2012-12-10

    Mitochondrial DNA damage, increased production of reactive oxygen species and progressive respiratory chain dysfunction, together with increased deposition of cholesterol and cholesteryl esters, are hallmarks of atherosclerosis. This study investigated the role of mitochondrial function in regulation of macrophage cholesterol efflux to apolipoprotein A-I, by the addition of established pharmacological modulators of mitochondrial function. Murine RAW 264.7 macrophages were treated with a range of concentrations of resveratrol, antimycin, dinitrophenol, nigericin and oligomycin, and changes in viability, cytotoxicity, membrane potential and ATP, compared with efflux of [3H]cholesterol to apolipoprotein (apo) A-I. The effect of oligomycin treatment on expression of genes implicated in macrophage cholesterol homeostasis were determined by quantitative polymerase chain reaction, and immunoblotting, relative to the housekeeping enzyme, Gapdh, and combined with studies of this molecule on cholesterol esterification, de novo lipid biosynthesis, and induction of apoptosis. Significant differences were determined using analysis of variance, and Dunnett's or Bonferroni post t-tests, as appropriate. The positive control, resveratrol (24 h), significantly enhanced cholesterol efflux to apoA-I at concentrations ≥30 μM. By contrast, cholesterol efflux to apoA-I was significantly inhibited by nigericin (45%; p<0.01) and oligomycin (55%; p<0.01), under conditions (10 μM, 3 h) which did not induce cellular toxicity or deplete total cellular ATP content. Levels of ATP binding cassette transporter A1 (ABCA1) protein were repressed by oligomycin under optimal efflux conditions, despite paradoxical increases in Abca1 mRNA. Oligomycin treatment did not affect cholesterol biosynthesis, but significantly inhibited cholesterol esterification following exposure to acetylated LDL, and induced apoptosis at ≥30 μM. Finally, oligomycin induced the expression of genes implicated in both

  8. Down-regulation of endothelial TLR4 signalling after apo A-I gene transfer contributes to improved survival in an experimental model of lipopolysaccharide-induced inflammation

    PubMed Central

    Van Linthout, Sophie; Spillmann, Frank; Graiani, Gallia; Miteva, Kapka; Peng, Jun; Van Craeyveld, Eline; Meloni, Marco; Tölle, Markus; Escher, Felicitas; Subasigüller, Aysun; Doehner, Wolfram; Quaini, Federico; De Geest, Bart; Schultheiss, Heinz-Peter

    2010-01-01

    The protective effects of high-density lipoprotein (HDL) under lipopolysaccharide (LPS) conditions have been well documented. Here, we investigated whether an effect of HDL on Toll-like receptor 4 (TLR4) expression and signalling may contribute to its endothelial-protective effects and to improved survival in a mouse model of LPS-induced inflammation and lethality. HDL cholesterol increased 1.7-fold (p < 0.005) and lung endothelial TLR4 expression decreased 8.4-fold (p < 0.005) 2 weeks after apolipoprotein (apo) A-I gene transfer. Following LPS administration in apo A-I gene transfer mice, lung TLR4 and lung MyD88 mRNA expression, reflecting TLR4 signalling, were 3.0-fold (p < 0.05) and 2.1-fold (p < 0.05) lower, respectively, than in LPS control mice. Concomitantly, LPS-induced lung neutrophil infiltration, lung oedema and mortality were significantly attenuated following apo A–I transfer. In vitro, supplementation of HDL or apo A–I to human microvascular endothelial cells-1 24 h before LPS administration reduced TLR4 expression, as assessed by fluorescent-activated cell sorting, and decreased the LPS-induced MyD88 mRNA expression and NF-κB activity, independently of LPS binding. In conclusion, HDL reduces TLR4 expression and signalling in endothelial cells, which may contribute significantly to the protective effects of HDL in LPS-induced inflammation and lethality. Electronic supplementary material The online version of this article (doi:10.1007/s00109-010-0690-6) contains supplementary material, which is available to authorized users. PMID:20972769

  9. Role of Esrrg in the fibrate-mediated regulation of lipid metabolism genes in human ApoA-I transgenic mice

    PubMed Central

    Sanoudou, D; Duka, A; Drosatos, K; Hayes, K C; Zannis, V I

    2009-01-01

    We have used a new ApoA-I transgenic mouse model to identify by global gene expression profiling, candidate genes that affect lipid and lipoprotein metabolism in response to fenofibrate treatment. Multilevel bioinformatical analysis and stringent selection criteria (2-fold change, 0% false discovery rate) identified 267 significantly changed genes involved in several molecular pathways. The fenofibrate-treated group did not have significantly altered levels of hepatic human APOA-I mRNA and plasma ApoA-I compared with the control group. However, the treatment increased cholesterol levels to 1.95-fold mainly due to the increase in high-density lipoprotein (HDL) cholesterol. The observed changes in HDL are associated with the upregulation of genes involved in phospholipid biosynthesis and lipid hydrolysis, as well as phospholipid transfer protein. Significant upregulation was observed in genes involved in fatty acid transport and β-oxidation, but not in those of fatty acid and cholesterol biosynthesis, Krebs cycle and gluconeogenesis. Fenofibrate changed significantly the expression of seven transcription factors. The estrogen receptor-related gamma gene was upregulated 2.36-fold and had a significant positive correlation with genes of lipid and lipoprotein metabolism and mitochondrial functions, indicating an important role of this orphan receptor in mediating the fenofibrate-induced activation of a specific subset of its target genes. PMID:19949424

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

    PubMed Central

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

    1994-01-01

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

  11. The Effects of Rope Training on Lymphocyte ABCA1 Expression, Plasma ApoA-I and HDL-c in Boy Adolescents

    PubMed Central

    Ghorbanian, Bahloul; Ravassi, Aliasghar; Kordi, Mohammad Reza; Hedayati, Mahdi

    2013-01-01

    Background Early obesity and its transfer to the adulthood, increases likelihood incidence of coronary artery disease (CAD). ATP-binding cassette transporter (ABCA1) as a member of the ABC transporters family plays a crucial role in reverse cholesterol transport and CAD prevention. Objective The current study aimed to investigate ABCA1 expression in lymphocytes, plasma apolipoprotein A-I and HDL-C in response to eight-week interval endurance rope training in overweight and obese boy adolescents. Patients and Methods Thirty students (17.3 ± 1.1 yr, 85.73 ± 11.68 kg and 28.41 ± 2.36 kg / m²) volunteered and were randomly assigned into training (n= 15) and control (n = 15) groups. Exercise protocol was interval endurance rope training (8 wk, 4 d/wk and 40 min/d). Cell hemolysis and sensitive Elisa method was used for Lymphocyte ABAC1 protein expression.t-test was employed. Results The independent-samples T-Test results showed that after 8 weeks IERT, the levels of lymphocyte ABCA1 expression (P = 0/001) and VO2max(P = 0/001) significantly increased and plasma levels of TG (P = 0.017), TC (P = 0.001), LDL-c/HDL-c (P = 0.026),TC/HDL-c (P = 0.002) and measures of BF% (P = 0/015) and BMI (P = 0.042) as anthropometric indicators significantly decreased. Changes of other variables such as increase in ApoA-I, HDL-c and decrease in LDL-c, body weight, were not significant. Conclusions The findings of this study proved that eight-week interval endurance rope training can have positive effects on lymphocyte ABCA1 protein expression (as gatekeeper of reverse cholesterol process) and lipid profiles among overweight and obese boy adolescents. PMID:23825977

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed Central

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

    2015-01-01

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

  14. High-density lipoprotein apolipoprotein A-I kinetics in obesity.

    PubMed

    Ooi, Esther M M; Watts, Gerald F; Farvid, Maryam S; Chan, Dick C; Allen, Michael C; Zilko, Simon R; Barrett, P Hugh R

    2005-06-01

    Low plasma concentrations of high-density lipoprotein (HDL)-cholesterol and apolipoprotein A-I (apoA-I) are independent predictors of coronary artery disease and are often associated with obesity and the metabolic syndrome. However, the underlying kinetic determinants of HDL metabolism are not well understood. We pooled data from 13 stable isotope studies to investigate the kinetic determinants of apoA-I concentrations in lean and overweight-obese individuals. We also examined the associations of HDL kinetics with age, sex, BMI, fasting plasma glucose, fasting insulin, Homeostasis Model Assessment score, and concentrations of apoA-I, triglycerides, HDL-cholesterol and low-density lipoprotein-cholesterol. Compared with lean individuals, overweight-obese individuals had significantly higher HDL apoA-I fractional catabolic rate (0.21+/-0.01 vs. 0.33+/-0.01 pools/d; p<0.001) and production rate (PR; 11.3+/-4.4 vs. 15.8+/-2.77 mg/kg per day; p=0.001). In the lean group, HDL apoA-I PR was significantly associated with apoA-I concentration (r=0.455, p=0.004), whereas in the overweight-obese group, both HDL apoA-I fractional catabolic rate (r=-0.396, p=0.050) and HDL apoA-I PR (r=0.399, p=0.048) were significantly associated with apoA-I concentration. After adjustment for fasting insulin or Homeostasis Model Assessment score, HDL apoA-I PR was an independent predictor of apoA-I concentration. In overweight-obese subjects, hypercatabolism of apoA-I is paralleled by an increased production of apoA-I, with HDL apoA-I PR being the stronger determinant of apoA-I concentration. This could have therapeutic implications for the management of dyslipidemia in individuals with low plasma HDL-cholesterol.

  15. Cumulative Brain Injury from Motor Vehicle-Induced Whole-Body Vibration and Prevention by Human Apolipoprotein A-I Molecule Mimetic (4F) Peptide (an Apo A-I Mimetic).

    PubMed

    Yan, Ji-Geng; Zhang, Lin-ling; Agresti, Michael; Yan, Yuhui; LoGiudice, John; Sanger, James R; Matloub, Hani S; Pritchard, Kirkwood A; Jaradeh, Safwan S; Havlik, Robert

    2015-12-01

    Insidious cumulative brain injury from motor vehicle-induced whole-body vibration (MV-WBV) has not yet been studied. The objective of the present study is to validate whether whole-body vibration for long periods causes cumulative brain injury and impairment of the cerebral function. We also explored a preventive method for MV-WBV injury. A study simulating whole-body vibration was conducted in 72 male Sprague-Dawley rats divided into 9 groups (N = 8): (1) 2-week normal control; (2) 2-week sham control (in the tube without vibration); (3) 2-week vibration (exposed to whole-body vibration at 30 Hz and .5 G acceleration for 4 hours/day, 5 days/week for 2 weeks; vibration parameters in the present study are similar to the most common driving conditions); (4) 4-week sham control; (5) 4-week vibration; (6) 4-week vibration with human apolipoprotein A-I molecule mimetic (4F)-preconditioning; (7) 8-week sham control; (8) 8-week vibration; and (9) 8-week 4F-preconditioning group. All the rats were evaluated by behavioral, physiological, and histological studies of the brain. Brain injury from vibration is a cumulative process starting with cerebral vasoconstriction, squeezing of the endothelial cells, increased free radicals, decreased nitric oxide, insufficient blood supply to the brain, and repeated reperfusion injury to brain neurons. In the 8-week vibration group, which indicated chronic brain edema, shrunken neuron numbers increased and whole neurons atrophied, which strongly correlated with neural functional impairment. There was no prominent brain neuronal injury in the 4F groups. The present study demonstrated cumulative brain injury from MV-WBV and validated the preventive effects of 4F preconditioning. Copyright © 2015 National Stroke Association. All rights reserved.

  16. Surface behavior of apolipoprotein A-I and its deletion mutants at model lipoprotein interfaces

    PubMed Central

    Wang, Libo; Mei, Xiaohu; Atkinson, David; Small, Donald M.

    2014-01-01

    Apolipoprotein A-I (apoA-I) has a great conformational flexibility to exist in lipid-free, lipid-poor, and lipid-bound states during lipid metabolism. To address the lipid binding and the dynamic desorption behavior of apoA-I at lipoprotein surfaces, apoA-I, Δ(185-243)apoA-I, and Δ(1-59)(185-243)apoA-I were studied at triolein/water and phosphatidylcholine/triolein/water interfaces with special attention to surface pressure. All three proteins are surface active to both interfaces lowering the interfacial tension and thus increasing the surface pressure to modify the interfaces. Δ(185-243)apoA-I adsorbs much more slowly and lowers the interfacial tension less than full-length apoA-I, confirming that the C-terminal domain (residues 185-243) initiates the lipid binding. Δ(1-59)(185-243)apoA-I binds more rapidly and lowers the interfacial tension more than Δ(185-243)apoA-I, suggesting that destabilizing the N-terminal α-helical bundle (residues 1-185) restores lipid binding. The three proteins desorb from both interfaces at different surface pressures revealing that different domains of apoA-I possess different lipid affinity. Δ(1-59)(185-243)apoA-I desorbs at lower pressures compared with apoA-I and Δ(185-243)apoA-I indicating that it is missing a strong lipid association motif. We propose that during lipoprotein remodeling, surface pressure mediates the adsorption and partial or full desorption of apoA-I allowing it to exchange among different lipoproteins and adopt various conformations to facilitate its multiple functions. PMID:24308948

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

    SciTech Connect

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

    1989-07-01

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

  18. Reduced Cerebrospinal Fluid Concentration of Apolipoprotein A-I in Patients with Alzheimer's Disease.

    PubMed

    Johansson, Per; Almqvist, Erik G; Bjerke, Maria; Wallin, Anders; Johansson, Jan-Ove; Andreasson, Ulf; Blennow, Kaj; Zetterberg, Henrik; Svensson, Johan

    2017-01-01

    Apolipoprotein E (ApoE) has been extensively studied in Alzheimer's disease (AD), but little is known of apolipoprotein A-I (ApoA-I) in cerebrospinal fluid (CSF). Plasma lipids as well as ApoA-I and ApoE in plasma and CSF were determined and related to Mini-Mental State Examination (MMSE) score, APOE genotype, and CSF AD biomarkers. Consecutive patients with AD (n = 29), stable mild cognitive impairment (n = 13), other dementias (n = 14), and healthy controls (n = 18) were included at a single center. AD patients had higher plasma triglycerides and lower CSF ApoA-I concentration than controls (both p < 0.05). CSF ApoE concentration was reduced in other dementias (p < 0.01). In AD as well as other dementias, the ratios between CSF and plasma concentrations of both ApoA-I and ApoE were lower than those in the controls. ApoA-I and ApoE in plasma and CSF were not influenced by APOEɛ4 allele distribution. In the total study population (n = 74), CSF ApoA-I correlated positively with MMSE score (r = 0.26, p < 0.05) and negatively with CSF P-tau (r = -0.25, p < 0.05). CSF ApoE correlated positively with CSF concentrations of T-tau and P-tau in the total study population and in AD patients. CSF ApoA-I was reduced in AD patients and associated with measures of cognitive function and AD disease status. The mechanisms underlying the decreased CSF:plasma ratios of ApoA-I and ApoE in AD and other dementias need to be explored in further studies.

  19. LXR Agonism Upregulates the Macrophage ABCA1/Syntrophin Protein Complex That Can Bind ApoA-I and Stabilized ABCA1 Protein, but Complex Loss Does Not Inhibit Lipid Efflux.

    PubMed

    Tamehiro, Norimasa; Park, Min Hi; Hawxhurst, Victoria; Nagpal, Kamalpreet; Adams, Marv E; Zannis, Vassilis I; Golenbock, Douglas T; Fitzgerald, Michael L

    2015-11-24

    Macrophage ABCA1 effluxes lipid and has anti-inflammatory activity. The syntrophins, which are cytoplasmic PDZ protein scaffolding factors, can bind ABCA1 and modulate its activity. However, many of the data assessing the function of the ABCA1-syntrophin interaction are based on overexpression in nonmacrophage cells. To assess endogenous complex function in macrophages, we derived immortalized macrophages from Abca1(+/+) and Abca1(-/-) mice and show their phenotype recapitulates primary macrophages. Abca1(+/+) lines express the CD11B and F4/80 macrophage markers and markedly upregulate cholesterol efflux in response to LXR nuclear hormone agonists. In contrast, immortalized Abca1(-/-) macrophages show no efflux to apoA-I. In response to LPS, Abca1(-/-) macrophages display pro-inflammatory changes, including an increased level of expression of cell surface CD14, and 11-26-fold higher levels of IL-6 and IL-12 mRNA. Given recapitulation of phenotype, we show with these lines that the ABCA1-syntrophin protein complex is upregulated by LXR agonists and can bind apoA-I. Moreover, in immortalized macrophages, combined α1/β2-syntrophin loss modulated ABCA1 cell surface levels and induced pro-inflammatory gene expression. However, loss of all three syntrophin isoforms known to bind ABCA1 did not impair lipid efflux in immortalized or primary macrophages. Thus, the ABCA1-syntrophin protein complex is not essential for ABCA1 macrophage lipid efflux but does directly interact with apoA-I and can modulate the pool of cell surface ABCA1 stabilized by apoA-I.

  20. The promise of apolipoprotein A-I mimetics.

    PubMed

    Mendez, Armando J

    2010-04-01

    Synthetic high-density lipoprotein (HDL) and apolipoprotein (apo) A-I mimetic peptides emulate many of the atheroprotective biological functions attributed to HDL and can modify atherosclerotic disease processes. Administration of these agents as HDL replacement or modifying therapy has tremendous potential of providing new treatments for cardiovascular disease. Progress in the understanding of these agents is discussed in this review. Prospective, observational, and interventional studies have convincingly demonstrated that elevated serum levels of high-density lipoprotein-cholesterol (HDL-C) are associated with reduced risk for coronary heart disease (CHD). Although traditional pharmacological agents have shown modest utility in raising HDL levels and reducing CHD risk, use of HDL and apo A-I mimetics provides novel therapies to not only increase HDL levels, but to also influence HDL functionality. Evidence developed over the last several years has identified a number of pathways affected by synthetic HDL and apoA-I mimetic peptides, including enhancing reverse cholesterol transport and reducing oxidation and inflammation that directly influence the progression and regression of atherosclerotic disease. Clinical trials of relatively short-term synthetic HDL infusion into patients with CHD demonstrate beneficial effects. Use of apo A-I mimetic peptides could potentially overcome some of the limitations associated with use of the intact apo. Studies to establish the most efficacious peptides, optimal dosing regimens, and routes of administration are needed. Use of apo A-I mimetic peptides shows great promise as a therapeutic modality for HDL replacement and enhancing HDL function in treatment of patients with CHD.

  1. Inhibition of apolipoprotein A-I gene expression by obesity-associated endocannabinoids.

    PubMed

    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. RISK and SAFE Signaling Pathway Involvement in Apolipoprotein A-I-Induced Cardioprotection

    PubMed Central

    Kalakech, Hussein; Hibert, Pierre; Prunier-Mirebeau, Delphine; Tamareille, Sophie; Letournel, Franck; Macchi, Laurent; Pinet, Florence; Furber, Alain; Prunier, Fabrice

    2014-01-01

    Recent findings indicate that apolipoprotein A-I (ApoA-I) may be a protective humoral mediator involved in remote ischemic preconditioning (RIPC). This study sought to determine if ApoA-I mediates its protective effects via the RISK and SAFE signaling pathways implicated in RIPC. Wistar rats were allocated to one of the following groups. Control: rats were subjected to myocardial ischemia/reperfusion (I/R) without any further intervention; RIPC: four cycles of limb I/R were applied prior to myocardial ischemia; ApoA-I: 10 mg/Kg of ApoA-I were intravenously injected prior to myocardial ischemia; ApoA-I + inhibitor: pharmacological inhibitors of RISK/SAFE pro-survival kinase (Akt, ERK1/2 and STAT-3) were administered prior to ApoA-I injection. Infarct size was significantly reduced in the RIPC group compared to Control. Similarly, ApoA-I injection efficiently protected the heart, recapitulating RIPC-induced cardioprotection. The ApoA-I protective effect was associated with Akt and GSK-3β phosphorylation and substantially inhibited by pretreatment with Akt and ERK1/2 inhibitors. Pretreatment with ApoA-I in a rat model of I/R recapitulates RIPC-induced cardioprotection and shares some similar molecular mechanisms with those of RIPC-involved protection of the heart. PMID:25237809

  3. Apolipoprotein A-I interactions with insulin secretion and production.

    PubMed

    Rye, Kerry-Anne; Barter, Philip J; Cochran, Blake J

    2016-02-01

    Human population studies have established that an elevated plasma high-density lipoprotein cholesterol (HDL-C) level is associated with a decreased risk of developing cardiovascular disease. In addition to having several potentially cardioprotective functions, HDLs and apolipoprotein (apo)A-I, the main HDL apolipoprotein, also have antidiabetic properties. Interventions that elevate plasma HDL-C and apoA-I levels improve glycemic control in people with type 2 diabetes mellitus by enhancing pancreatic β-cell function and increasing insulin sensitivity. This review is concerned with recent advances in understanding the mechanisms by which HDLs and apoA-I improve pancreatic β-cell function. HDLs and apoA-I increase insulin synthesis and secretion in pancreatic β cells. The underlying mechanism of this effect is similar to what has been reported for intestinally derived incretins, such as glucagon-like peptide-1 and glucose-dependent insulinotropic polypeptide, which both increase β-cell insulin secretion under high glucose conditions. This involves the activation of a heterotrimeric G protein Gαs subunit on the β-cell surface that leads to induction of a transmembrane adenylyl cyclase, increased intracellular cyclic adenosine monophosphate and Ca levels, and activation of protein kinase A. Protein kinase A increases insulin synthesis by excluding FoxO1 from the β-cell nucleus and derepressing transcription of the insulin gene.

  4. Human Apolipoprotein A-I Natural Variants: Molecular Mechanisms Underlying Amyloidogenic Propensity

    PubMed Central

    Ramella, Nahuel A.; Schinella, Guillermo R.; Ferreira, Sergio T.; Prieto, Eduardo D.; Vela, María E.; Ríos, José Luis

    2012-01-01

    Human apolipoprotein A-I (apoA-I)-derived amyloidosis can present with either wild-type (Wt) protein deposits in atherosclerotic plaques or as a hereditary form in which apoA-I variants deposit causing multiple organ failure. More than 15 single amino acid replacement amyloidogenic apoA-I variants have been described, but the molecular mechanisms involved in amyloid-associated pathology remain largely unknown. Here, we have investigated by fluorescence and biochemical approaches the stabilities and propensities to aggregate of two disease-associated apoA-I variants, apoA-IGly26Arg, associated with polyneuropathy and kidney dysfunction, and apoA-ILys107-0, implicated in amyloidosis in severe atherosclerosis. Results showed that both variants share common structural properties including decreased stability compared to Wt apoA-I and a more flexible structure that gives rise to formation of partially folded states. Interestingly, however, distinct features appear to determine their pathogenic mechanisms. ApoA-ILys107-0 has an increased propensity to aggregate at physiological pH and in a pro-inflammatory microenvironment than Wt apoA-I, whereas apoA-IGly26Arg elicited macrophage activation, thus stimulating local chronic inflammation. Our results strongly suggest that some natural mutations in apoA-I variants elicit protein tendency to aggregate, but in addition the specific interaction of different variants with macrophages may contribute to cellular stress and toxicity in hereditary amyloidosis. PMID:22952757

  5. Apolipoprotein A-I and A-I mimetic peptides: a role in atherosclerosis

    PubMed Central

    Getz, Godfrey S; Reardon, Catherine A

    2011-01-01

    Cardiovascular disease remains a major cause of morbidity and mortality in the westernized world. Atherosclerosis is the underlying cause of most cardiovascular diseases. Atherosclerosis is a slowly evolving chronic inflammatory disorder involving the intima of large and medium sized arteries that is initiated in response to high plasma lipid levels, especially LDL. Cells of both the innate and adaptive immunity are involved in this chronic inflammation. Although high plasma LDL levels are a major contributor to most stages of the evolution of atherosclerosis, HDL and its major protein apoA-I possess properties that attenuate and may even reverse atherosclerosis. Two major functions are the ability to induce the efflux of cholesterol from cells, particularly lipid-loaded macrophages, in the artery wall for transfer to the liver, a process referred to as reverse cholesterol transport, and the ability to attenuate the pro-inflammatory properties of LDL. The removal of cellular cholesterol from lipid-loaded macrophages may also be anti-inflammatory. One of the most promising therapies to enhance the anti-atherogenic, anti-inflammatory properties of HDL is apoA-I mimetic peptides. Several of these peptides have been shown to promote cellular cholesterol efflux, attenuate the production of pro-inflammatory cytokines by macrophages, and to attenuate the pro-inflammatory properties of LDL. This latter effect may be related to their high affinity for oxidized lipids present in LDL. This review discusses the functional properties of the peptides and their effect on experimental atherosclerosis and the results of initial clinical studies in humans. PMID:22096372

  6. Nucleotide sequence and the encoded amino acids of human apolipoprotein A-I mRNA.

    PubMed Central

    Law, S W; Brewer, H B

    1984-01-01

    The cDNA clones encoding the precursor form of human liver apolipoprotein A-I (apoA-I), preproapoA-I, have been isolated from a cDNA library. A 17-base synthetic oligonucleotide based on residues 108-113 of apoA-I and a 26-base primer-extended, dideoxynucleotide-terminated cDNA were used as hybridization probes to select for recombinant plasmids bearing the apoA-I sequence. The complete nucleic acid sequence of human liver preproapoA-I has been determined by analysis of the cloned cDNA. The sequence is composed of 801 nucleotides encoding 267 amino acid residues. PreproapoA-I contains an 18-amino-acid prepeptide and a 6-amino-acid propeptide connected to the amino terminus of the 243-amino acid mature apoA-I. Southern blotting analysis of chromosomal DNA obtained from peripheral blood indicated the apoA-I gene is contained in a 2.1-kilobase-pair Pst I fragment and there is no gross difference in structural organization between the normal apoA-I gene and the Tangier disease apoA-I gene. Images PMID:6198645

  7. Induction of apolipoprotein A-I gene expression by black seed (Nigella sativa) extracts.

    PubMed

    Haas, Michael J; Onstead-Haas, Luisa M; Naem, Emad; Wong, Norman C W; Mooradian, Arshag D

    2014-09-01

    Black seed [Nigella sativa L. (Ranunculaceae)] has been shown in animal models to lower serum cholesterol levels. In order to determine if extracts from black seed have any effects on high-density lipoprotein (HDL), we characterized the effects of black seed extract on apolipoprotein A-I (apo A-I) gene expression, the primary protein component of HDL. Hepatocytes (HepG2) and intestinal cells (Caco-2) were treated with black seed extracts, and Apo A-I, peroxisome proliferator-activated receptor α (PPARα), and retinoid-x-receptor α (RXRα) were measured by Western blot analysis. Apo A-I mRNA levels were measured by quantitative real-time polymerase chain reaction and apo A-I gene transcription was measured by transient transfection of apo A-I reporter plasmids. Extracts from black seeds significantly increased hepatic and intestinal apo A-I secretion, as well as apo A-I mRNA and gene promoter activity. This effect required a PPARα binding site in the apo A-I gene promoter. Treatment of the extract with either heat or trypsin had no effect on its ability to induce apo A-I secretion. Treatment with black seed extract induced PPARα expression 9-fold and RXRα expression 2.5-fold. Furthermore, the addition of PPARα siRNA but not a control siRNA prevented some but not all the positive effects of black seed on apo A-I secretion. Black seed extract is a potent inducer of apo A-I gene expression, presumably by enhancing PPARα/RXRα expression. We conclude that black seed may have beneficial effects in treating dyslipidemia and coronary heart disease.

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

    PubMed

    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. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

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

    PubMed

    Mangaraj, Manaswini; Nanda, Rachita; Panda, Suchismita

    2016-07-01

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

  10. Correlations Between Serum Apolipoprotein A-I and Formation of Vocal Cord Polyp.

    PubMed

    Zhang, Hui-Ping; Zhang, Rong

    2017-05-01

    This study aims to investigate the correlations between serum apolipoprotein A-I (ApoA-I) and the formation of vocal cord polyps (VCPs). This study used the nonmatched case-control study method. The serum total cholesterol (TC), triglyceride, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol, ApoA-I, apolipoprotein B (ApoB), and ApoA-I/ApoB levels of 89 VCP patients and 87 normal volunteers were compared. Additionally, such VCP-related factors as excessive vocal use, vocal abuse, smoking, drinking, and the size of VCPs were analyzed. The two groups did not significantly differ with regard to triglyceride, low-density lipoprotein cholesterol, ApoB, and ApoA-I/ApoB levels (P > 0.05), whereas they did significantly differ with regard to TC, HDL-C, and ApoA-I levels (P < 0.05) according to independent t tests. Logistic regression analysis showed that excessive vocal use and vocal abuse were risk factors for VCPs (P < 0.05), with odds ratio values of 5.675 and 12.781, respectively. The ApoA-I level was negatively associated with VCPs (P < 0.05), with an odds ratio of 0.511; however, TC and HDL-C were not associated with the formation of VCPs (P > 0.05). The size of VCPs in females was negatively correlated with the serum ApoA-I level (r = -0.349, P = 0.032), whereas that in males was not (P > 0.05). As the serum ApoA-I level was negatively correlated with the formation of VCPs, ApoA-I may reduce the risk of VCPs. These findings may facilitate the prevention and treatment of VCPs. Copyright © 2017. Published by Elsevier Inc.

  11. Isolation and function analysis of apolipoprotein A-I gene response to virus infection in grouper.

    PubMed

    Wei, Jingguang; Gao, Pin; Zhang, Ping; Guo, Minglan; Xu, Meng; Wei, Shina; Yan, Yang; Qin, Qiwei

    2015-04-01

    Apolipoproteins, synthesized mainly in liver and intestine and bounded to lipids, play important roles in lipid transport and uptake through the circulation system. In this study, an apolipoprotein A-I gene homologue was cloned from orange-spotted grouper Epinephelus coioides (designed as Ec-ApoA-I) by rapid amplification of cDNA ends (RACE) PCR. The full-length cDNA of Ec-ApoA-I was comprised of 1278 bp with a 792 bp open reading frame (ORF) that encodes a putative protein of 264 amino acids. Quantitative real-time PCR (qPCR) analysis revealed that Ec-ApoA-I was abundant in liver and intestine, and the expression in liver was significantly (P < 0.01) up-regulated after the stimulation of LPS, Poly(I:C), Vibrio alginolyticus, and Singapore grouper iridovirus (SGIV). Recombinant Ec-ApoA-I (rEc-ApoA-I) was produced in Escherichia coli BL21 (DE3) expression system exhibited bacteriolyticactivity against Microcococcus lysodeikticus and Aeromonas hydrophila. Intracellular localization revealed that Ec-ApoA-I distributed in both cytoplasm and nucleus, and predominantly in the cytoplasm. Overexpression of Ec-ApoA-I in grouper Brain (GB) cells could inhibit the replication of SGIV. These results together indicated that Ec-ApoA-I perhaps is involved in the responses to bacterial and viral challenge. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Matrix metalloproteinase 8 degrades apolipoprotein A-I and reduces its cholesterol efflux capacity.

    PubMed

    Salminen, Aino; Åström, Pirjo; Metso, Jari; Soliymani, Rabah; Salo, Tuula; Jauhiainen, Matti; Pussinen, Pirkko J; Sorsa, Timo

    2015-04-01

    Various cell types in atherosclerotic lesions express matrix metalloproteinase (MMP)-8. We investigated whether MMP-8 affects the structure and antiatherogenic function of apolipoprotein (apo) A-I, the main protein component of HDL particles. Furthermore, we studied serum lipid profiles and cholesterol efflux capacity in MMP-8-deficient mouse model. Incubation of apoA-I (28 kDa) with activated MMP-8 yielded 22 kDa and 25 kDa apoA-I fragments. Mass spectrometric analyses revealed that apoA-I was cleaved at its carboxyl-terminal part. Treatment of apoA-I and HDL with MMP-8 resulted in significant reduction (up to 84%, P < 0.001) in their ability to facilitate cholesterol efflux from cholesterol-loaded THP-1 macrophages. The cleavage of apoA-I by MMP-8 and the reduction in its cholesterol efflux capacity was inhibited by doxycycline. MMP-8-deficient mice had significantly lower serum triglyceride (TG) levels (P = 0.003) and larger HDL particles compared with wild-type (WT) mice. However, no differences were observed in the apoA-I levels or serum cholesterol efflux capacities between the mouse groups. Proteolytic modification of apoA-I by MMP-8 may impair the first steps of reverse cholesterol transport, leading to increased accumulation of cholesterol in the vessel walls. Eventually, inhibition of MMPs by doxycycline may reduce the risk for atherosclerotic vascular diseases.

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

    SciTech Connect

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

    1987-05-01

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

  14. Cholesterol Independent Suppression of Lymphocyte Activation, Autoimmunity and Glomerulonephritis by Apolipoprotein A-I in Normocholesterolemic Lupus-Prone Mice

    PubMed Central

    Black, Leland L.; Srivastava, Roshni; Schoeb, Trenton R.; Moore, Ray D.; Barnes, Stephen; Kabarowski, Janusz H.

    2015-01-01

    Apolipoprotein A-I (ApoA-I), the major lipid-binding protein of high-density lipoprotein (HDL), can prevent autoimmunity and suppress inflammation in hypercholesterolemic mice by attenuating lymphocyte cholesterol accumulation and removing tissue oxidized lipids. However, whether ApoA-I mediates immune suppressive or anti-inflammatory effects in normocholesterolemic conditions and the mechanisms involved remain unresolved. We transferred bone marrow from SLE-prone Sle123 mice into normal, ApoA-I knockout (ApoA-I−/−) and ApoA-I transgenic (ApoA-Itg) mice. Increased ApoA-I in ApoA-Itg mice suppressed CD4+ T and B cell activation without changing lymphocyte cholesterol levels or reducing major ApoA-I-binding oxidized fatty acids. Unexpectedly, oxidized fatty acid peroxisome proliferator-activated receptor gamma (PPARγ) ligands 13-hydroxyoctadecadienoic acid (HODE) and 9-HODE were increased in lymphocytes of autoimmune ApoA-Itg mice. ApoA-I reduced Th1 cells independently of changes in CD4+FoxP3+ regulatory T cells or CD11c+ dendritic cell activation and migration. Follicular helper T cells, germinal center B cells and autoantibodies were also lower in ApoA-Itg mice. Transgenic ApoA-I also improved SLE-mediated glomerulonephritis. However, ApoA-I deficiency did not have opposite effects on autoimmunity or glomerulonephritis, possibly due to compensatory increases of ApoE on HDL. We conclude that although compensatory mechanisms prevent pro-inflammatory effects of ApoA-I deficiency in normocholesterolemic mice, increasing ApoA-I can attenuate lymphocyte activation and autoimmunity in SLE independently of cholesterol transport, possibly through oxidized fatty acid PPARγ ligands, and can reduce renal inflammation in glomerulonephritis. PMID:26466956

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

    DOEpatents

    Oda, Michael N.; Forte, Trudy M.

    2007-05-29

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

  16. Apolipoprotein A-I assayed in human serum by isotope dilution as a potential standard for immunoassay

    SciTech Connect

    Weech, P.K.; Jewer, D.; Marcel, Y.L.

    1988-01-01

    We measured the amount of apoA-I in serum by isotope dilution, finding 1.33 mg/ml (standard deviation 0.177) in six normolipidemic, healthy subjects. We developed this method by adapting published techniques to purify apoA-I from 3 ml of serum in two steps: density gradient ultracentrifugation and high performance liquid chromatography gel filtration. The 125I-labeled apoA-I tracer was first screened, by incubation with serum, to select labeled apoA-I which retained the ability to exchange with native apoA-I and bind to HDL. A known amount of 125I-labeled apoA-I-labeled HDL was added to unknown serum samples; apoA-I was reisolated from the serum and its specific radioactivity was used to calculate the dilution of the added, labeled apoA-I by the unlabeled apoA-I in the unknown serum. By not relying on immunochemical techniques, the isotope dilution assay provided results that are independent of the expression of individual apoA-I antigenic sites. Therefore, sera that have been assayed by isotope dilution can serve as standards to evaluate the accuracy of immunoassays for serum apoA-I and provide primary standards for such immunoassays.

  17. The Concentration of Apolipoprotein A-I Decreases during Experimentally Induced Acute-Phase Processes in Pigs

    PubMed Central

    Carpintero, R.; Piñeiro, M.; Andrés, M.; Iturralde, M.; Alava, M. A.; Heegaard, P. M. H.; Jobert, J. L.; Madec, F.; Lampreave, F.

    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 than the initial values, were observed at 2 to 4 days. It is concluded that ApoA-I is a negative acute-phase protein in pigs. PMID:15845530

  18. High-Throughput Analysis Identifying Drugs That Regulate Apolipoprotein A-I Synthesis.

    PubMed

    Haas, Michael J; Onstead-Haas, Luisa; Kurban, William; Shah, Harshit; Plazarte, Monica; Chamseddin, Ayham; Mooradian, Arshag D

    2017-07-25

    Apolipoprotein A-I (apo A-I) is the primary antiatherogenic protein in high-density lipoprotein (HDL). Despite the controversy as to the clinical effectiveness of raising HDL, the search is ongoing for safe and effective drugs that increase HDL and apo A-I levels. To identify novel compounds that can increase hepatic apo A-I production, two drug libraries were screened. The NIH clinical collection (NCC) and the NIH clinical collection 2 (NCC2) were purchased from Evotec (San Francisco, CA). The NCC library contains 446 compounds and the NCC2 library contains 281 compounds, all dissolved in dimethylsulfoxide at a concentration of 10 mM. Hepatoma-derived cells (HepG2) and primary hepatocytes in culture were treated with various compounds for 24 h and apo A-I in media samples was measured by enzyme immunoassay. Samples with significant changes in apo A-I concentrations were retested in independent experiments by Western blot analysis to confirm the immunoassay findings. Of a total of 727 compounds screened at a concentration of 50 μM, 15 compounds increased hepatic apo A-I production by 35%-54%, and 9 compounds lowered hepatic apo A-I concentrations in the culture media by 25%-52%. Future trials should explore the clinical effectiveness of these agents when standard doses of these drugs are used in humans.

  19. Serum apolipoprotein A-I is a novel prognostic indicator for non-metastatic nasopharyngeal carcinoma.

    PubMed

    Luo, Xiao-Lin; Zhong, Guang-Zheng; Hu, Li-Yang; Chen, Jie; Liang, Ying; Chen, Qiu-Yan; Liu, Qing; Rao, Hui-Lan; Chen, Kai-Lin; Cai, Qing-Qing

    2015-12-22

    We investigated the value of pretreatment serum apolipoprotein A-I (ApoA-I) in complementing TNM staging in the prognosis of non-metastatic nasopharyngeal carcinoma (NPC). We retrospectively reviewed 1196 newly diagnosed patients with non-metastatic NPC. Disease-specific survival (DSS), distant metastasis-free survival (DMFS), and locoregional recurrence-free survival (LRFS) rates were compared according to serum ApoA-I level. Multivariate analysis was performed to assess the prognostic value of serum ApoA-I. The 5-year DSS, DMFS, and LRFS rates for patients with elevated or decreased serum ApoA-I were 81.3% versus 69.3% (P < 0.001), 83.4% versus 67.4% (P < 0.001), and 80.9% versus 67.3% (P < 0.001), respectively. ApoA-I ≥ 1.025 g/L was an independent prognostic factor for superior DSS, DMFS, and LRFS in multivariate analysis. After stratification by clinical stage, serum ApoA-I remained a clinically and statistically significant predictor of prognosis. Our data suggest that the level of ApoA-I at diagnosis is a novel independent prognostic marker that could complement clinical staging for risk definition in non-metastatic NPC.

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

    SciTech Connect

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

    2010-07-23

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

  1. Anti-apolipoprotein A-I antibodies and paraoxonase 1 activity in Systemic Lupus Erythematosus

    PubMed Central

    Ahmed, Mohammed Mahmoud; Elserougy, Eman Mahmoud; Al-Gazzar, Iman Ibrahim; Fikry, Iman Mohamed; Habib, Dawoud Fakhry; Younes, Khaled Mohamed; Salem, Neveen Abd El-hameed

    2013-01-01

    Systemic lupus erythematosus (SLE) patients have an increased risk of atherosclerosis. Identification of at-risk patients and the pathogenesis of atherosclerosis in SLE remain elusive. Paraoxonase 1 (PON1) and anti-apolipoprotein A-I antibody (anti-Apo A-I) appear to have a potential role in premature atherosclerosis in SLE. The aim of this work was to study PON1 activity and anti-Apo A-I antibody in SLE female patients and to demonstrate their relations to disease activity as well as disease related damage. Forty SLE female patients and 40 apparently healthy volunteers were included. Anti-Apo A-I antibodies levels and PON1 activity levels were assessed. Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) and systemic Lupus International Collaboration Clinics (SLICC)/American College of Rheumatology (ACR) damage index were preformed in all patients. Compared with controls, SLE patients showed significantly lower PON1 activity and significantly higher titers of anti-Apo A-I. Anti-Apo A-I antibody titers correlated inversely with PON1 activity. Elevated titers of anti-Apo A-I antibody and reduced PON activity were related to increased SLEDAI and (SLICC/ACR) damage index scores. We concluded that there is decreased PON1 activity and formation of anti-Apo A-I antibodies in female patients with SLE. SLE-disease activity assessed by SLEDAI and SLE disease related organ damage assessed by SLICC/ACR damage index are negatively correlated with PON1 activity and positively correlated with anti-Apo A-I antibodies. PON1 activity and anti-Apo A-I antibodies might be involved in the pathogenesis of atherosclerosis in SLE patients. PMID:26622215

  2. Overexpression of apolipoprotein A-I alleviates endoplasmic reticulum stress in hepatocytes.

    PubMed

    Guo, Qing; Zhang, Can; Wang, Yutong

    2017-06-02

    Abnormal lipid metabolism may contribute to an increase in endoplasmic reticulum (ER) stress, resulting in the pathogenesis of non-alcoholic steatohepatitis. Apolipoprotein A-I (apoA-I) accepts cellular free cholesterol and phospholipids transported by ATP-binding cassette transporter A1 to generate nascent high density lipoprotein particles. Previous studies have revealed that the overexpression of apoA-I alleviated hepatic lipid levels by modifying lipid transport. Here, we examined the effects of apoA-I overexpression on ER stress and genes involved in lipogenesis in both HepG2 cells and mouse hepatocytes. Human apoA-I was overexpressed in HepG2 hepatocytes, which were then treated with 2 μg/mL tunicamycin or 500 μM palmitic acid. Eight-week-old male apoA-I transgenic or C57BL/6 wild-type mice were intraperitoneally injected with 1 mg/kg body weight tunicamycin or with saline. At 48 h after injecting, blood and liver samples were collected. The overexpression of apoA-I in the models above resulted in decreased protein levels of ER stress makers and lipogenic gene products, including sterol regulatory element binding protein 1, fatty acid synthase, and acetyl-CoA carboxylase 1. In addition, the cellular levels of triglycerides and free cholesterol also decreased. Some of gene products which are related to ER stress-associated apoptosis were also affected by apoA-I overexpression. These results suggested that apoA-I overexpression could reduce steatosis by decreasing lipid levels and by suppressing ER stress and lipogenesis in hepatocytes. ApoA-I expression could significantly reduce hepatic ER stress and lipogenesis in hepatocytes.

  3. Apolipoprotein B and A-I ratio predicts severe acute pancreatitis.

    PubMed

    Huh, Ji Hye; Jung, Saehyun; Cho, Seung Kook; Lee, Kyong Joo; Kim, Jae Woo

    2017-07-05

    Severe acute pancreatitis (SAP) has considerable mortality and morbidity rates. Although many indices have been developed to classify the severity of acute pancreatitis (AP), an optimal method for predicting SAP has not been identified. The ratio of apolipoprotein B to A-I (apoB/A-I) is associated with metabolic syndrome and inflammatory status. This study investigated the association between severity of AP and serum apoB/A-I ratio. Patients with AP were prospectively enrolled at Yonsei University Wonju College of Medicine from March 2015 to August 2016. The severity of AP was assessed according to the revised Atlanta classification criteria (Atlanta 2012). Of 191 patients with AP, 134 (70.2%) had mild AP, 42 (22%) had moderately severe AP, and 15 (7.9%) had SAP; apoB/A-I ratio was highest in patients with SAP (P = 0.001). The apoB/A-I ratio was positively correlated with Atlanta classification, computed tomography severity index, and Bedside index for severity of AP. The apoB/A-I ratio showed the highest predictive value for SAP in patients with AP compared with apolipoprotein B or apolipoprotein A-I alone. Serum apoB/A-I ratio appears to have value for predicting SAP in patients with AP. This article is protected by copyright. All rights reserved.

  4. Intravenously injected human apolipoprotein A-I rapidly enters the central nervous system via the choroid plexus.

    PubMed

    Stukas, Sophie; Robert, Jerome; Lee, Michael; Kulic, Iva; Carr, Michael; Tourigny, Katherine; Fan, Jianjia; Namjoshi, Dhananjay; Lemke, Kalistyne; DeValle, Nicole; Chan, Jeniffer; Wilson, Tammy; Wilkinson, Anna; Chapanian, Rafi; Kizhakkedathu, Jayachandran N; Cirrito, John R; Oda, Michael N; Wellington, Cheryl L

    2014-11-12

    Brain lipoprotein metabolism is dependent on lipoprotein particles that resemble plasma high-density lipoproteins but that contain apolipoprotein (apo) E rather than apoA-I as their primary protein component. Astrocytes and microglia secrete apoE but not apoA-I; however, apoA-I is detectable in both cerebrospinal fluid and brain tissue lysates. The route by which plasma apoA-I enters the central nervous system is unknown. Steady-state levels of murine apoA-I in cerebrospinal fluid and interstitial fluid are 0.664 and 0.120 μg/mL, respectively, whereas brain tissue apoA-I is ≈10% to 15% of its levels in liver. Recombinant, fluorescently tagged human apoA-I injected intravenously into mice localizes to the choroid plexus within 30 minutes and accumulates in a saturable, dose-dependent manner in the brain. Recombinant, fluorescently tagged human apoA-I accumulates in the brain for 2 hours, after which it is eliminated with a half-life of 10.3 hours. In vitro, human apoA-I is specifically bound, internalized, and transported across confluent monolayers of primary human choroid plexus epithelial cells and brain microvascular endothelial cells. Following intravenous injection, recombinant human apoA-I rapidly localizes predominantly to the choroid plexus. Because apoA-I mRNA is undetectable in murine brain, our results suggest that plasma apoA-I, which is secreted from the liver and intestine, gains access to the central nervous system primarily by crossing the blood-cerebrospinal fluid barrier via specific cellular mediated transport, although transport across the blood-brain barrier may also contribute to a lesser extent. © 2014 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

  5. Defective removal of cellular cholesterol and phospholipids by apolipoprotein A-I in Tangier Disease.

    PubMed Central

    Francis, G A; Knopp, R H; Oram, J F

    1995-01-01

    Tangier disease is a rare genetic disorder characterized by extremely low plasma levels of HDL and apo A-I, deposition of cholesteryl esters in tissues, and a high prevalence of cardiovascular disease. We examined the possibility that HDL apolipoprotein-mediated removal of cellular lipids may be defective in Tangier disease. With fibroblasts from normal subjects, purified apo A-I cleared cells of cholesteryl esters, depleted cellular free cholesterol pools available for esterification, and stimulated efflux of radiolabeled cholesterol, phosphatidylcholine, and sphingomyelin. With fibroblasts from two unrelated Tangier patients, however, apo A-I had little or no effect on any of these lipid transport processes. Intact HDL also was unable to clear cholesteryl esters from Tangier cells even though it promoted radiolabeled cholesterol efflux to levels 50-70% normal. Passive desorption of radiolabeled cholesterol or phospholipids into medium containing albumin or trypsinized HDL was normal for Tangier cells. Binding studies showed that the interaction of apo A-I with high-affinity binding sites on Tangier fibroblasts was abnormal. These results indicate that apo A-I has an impaired ability to remove cholesterol and phospholipid from Tangier fibroblasts, possibly because of a defective interaction of apo A-I with cell-surface binding sites. Failure of apo A-I to acquire cellular lipids may account for the rapid catabolism of nascent HDL particles and the low plasma HDL levels in Tangier disease. Images PMID:7615839

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

    PubMed Central

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

    2014-01-01

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

  7. Apolipoprotein A-I Milano exhibits potent antioxidant activity on phospholipid surfaces

    SciTech Connect

    Bielicki, John K.; Oda, Michael N.

    2001-09-21

    Apolipoprotein(apo)A-IMilano and apoA-IParis are rare cysteine variants of apoA-I that produce a HDL deficiency in the absence of cardiovascular disease in humans. This paradox provides the basis for the hypothesis that the cysteine variants posses a beneficial activity not associated with wild-type apoA-I (apoA-IWT). In this study, a unique antioxidant activity of apoA-IMilano and apoA-IParis is described. Antioxidant activity was observed using the monomeric form of the variants and was equally effective before and after initiation of oxidative events. ApoA-IMilano was twice as effective as apoA-IParis in preventing lipoxygenase-mediated oxidation of phospholipids; whereas, apoA-IWT was poorly active. ApoA-IMilano protected phospholipid from reactive oxygen species (ROS) generated via xanthine/xanthine oxidase (X/Xo) but failed to inhibit X/Xo induced reduction of cytochrome C. These results indicate that (1) the antioxidant activity of apoA-IMilano was dependent on phospholipid and (2) the cysteine variant was unable to directly quench ROS in the aqueous phase. There were no differences between lipid-free apoA-IMilano, apoA-IParis, and apoA-IWT in mediating the efflux of cholesterol from macrophages indicating the cysteine variants interacted normally with the ABCA1 efflux pathway. The results indicate that incorporation of a free thiol within an amphipathic alpha helix of apoA-I confers an antioxidant activity distinct from that of apoA-IWT. These studies are the first to relate addition-of-function to rare cysteine mutations in apoA-I primary sequence.

  8. Expression of the C-terminal domain of human apolipoprotein A-I using a chimeric apolipoprotein.

    PubMed

    Sallee, Daniel E; Horn, James V C; Fuentes, Lukas A; Weers, Paul M M

    2017-09-01

    Human apolipoprotein A-I (apoA-I) is the most abundant protein in high-density lipoprotein, an anti-atherogenic lipid-protein complex responsible for reverse cholesterol transport. The protein is composed of an N-terminal helix bundle domain, and a small C-terminal (CT) domain. To facilitate study of CT-apoA-I, a novel strategy was employed to produce this small domain in a bacterial expression system. A protein construct was designed of insect apolipophorin III (apoLp-III) and residues 179-243 of apoA-I, with a unique methionine residue positioned between the two proteins and an N-terminal His-tag to facilitate purification. The chimera was expressed in E. coli, purified by Ni-affinity chromatography, and cleaved by cyanogen bromide. SDS-PAGE revealed the presence of three proteins with masses of 7 kDa (CT-apoA-I), 18 kDa (apoLp-III), and a minor 26 kDa band of uncleaved chimera. The digest was reloaded on the Ni-affinity column to bind apoLp-III and uncleaved chimera, while CT-apoA-I was washed from the column and collected. Alternatively, CT-apoA-I was isolated from the digest by reversed-phase HPLC. CT-apoA-I was α-helical, highly effective in solubilizing phospholipid vesicles and disaggregating LPS micelles. However, CT-apoA-I was less active compared to full-length apoA-I in protecting lipolyzed low density lipoproteins from aggregating, and disrupting phosphatidylglycerol bilayer vesicles. Thus the novel expression system produced mg quantities of functional CT-apoA-I, facilitating structural and functional studies of this critical domain of apoA-I. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Apolipoprotein A-I and B and Subjective Global Assessment relationship can reflect lipid defects in diabetic retinopathy.

    PubMed

    Sharma, Yashodhara; Saxena, Sandeep; Mishra, Arvind; Saxena, Anita; Natu, Shankar Madhav

    2017-01-01

    Elevated lipid levels increase complications of diabetic retinopathy (DR). Uncontrolled diabetes increases these complications and causes unintentional weight loss, indicating an apparently normal body mass index (BMI). Thus, it is easy to assume that patients with DR and a normal BMI have optimal lipid status. Apolipoprotein (Apo) A-I and Apo B levels differentially indicate serum lipid status in DR. Subjective Global Assessment (SGA) scores are associated with DR status. If SGA scores and serum Apo A-I and B levels are found to be interrelated, their relationship can reflect lipid defects in patients with DR despite apparently normal BMI. The aim of the present study was to investigate the possible relationship between serum Apo A-I and B levels and SGA scores of patients with DR. This was a case-control study conducted from November 2011 to April 2014. Serum Apo A-I and B levels and SGA scores were calculated for 40 healthy controls, 48 individuals without DR, 49 nonproliferative DR cases, and 48 proliferative DR cases. Pearson's correlation analysis was applied between Apo A-I, Apo B, Apo B/Apo A-I ratio, and SGA scores. Negative correlation was observed between serum Apo A-I level (r = -0.567, P < 0.001) and positive correlation between serum Apo B level (r = 0.451, P < 0.001) and Apo B/Apo A-I ratio (r = 0.597, P < 0.001) with escalating SGA scores. To our knowledge, this is the first study to report a novel correlation between serum Apo A-I, Apo B and Apo B/Apo A-I ratio and SGA scores. SGA scores can help predict lipid abnormalities in patients with DR even when they have an apparently normal BMI. Copyright © 2016 Elsevier Inc. All rights reserved.

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

    PubMed Central

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

    2015-01-01

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

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

    DOE PAGES

    Zhang, Xing; Lei, Dongsheng; Zhang, Lei; ...

    2015-03-20

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

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

    SciTech Connect

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

    2015-03-20

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

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

    PubMed Central

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

    2009-01-01

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

  14. Apolipoprotein A-I structural organization in high density lipoproteins isolated from human plasma

    PubMed Central

    Huang, Rong; Gangani D. Silva, R. A.; Jerome, W. Gray; Kontush, Anatol; Chapman, M. John; Curtiss, Linda K.; Hodges, Timothy J.; Davidson, W. Sean

    2010-01-01

    High density lipoproteins (HDL) mediate cholesterol transport and protection from cardiovascular disease. Although synthetic HDLs have been studied for 30 years, the structure of human plasma-derived HDL, and its major protein apolipoprotein (apo)A-I, is unknown. We separated normal human HDL into 5 density subfractions and then further isolated those containing predominantly apoA-I (LpA-I). Using cross-linking chemistry and mass spectrometry, we found that apoA-I adopts a structural framework in these particles that closely mirrors that in synthetic HDL. We adapted established structural models for synthetic HDL to generate the first detailed models of authentic human plasma HDL in which apoA-I adopts a symmetrical cage-like structure. The models suggest that HDL particle size is modulated via a twisting motion of the resident apoA-I molecules. This understanding offers insights into how apoA-I structure modulates HDL function and its interactions with other apolipoproteins. PMID:21399642

  15. Apolipoprotein A-I Modulates Atherosclerosis Through Lymphatic Vessel-Dependent Mechanisms in Mice.

    PubMed

    Milasan, Andreea; Jean, Gabriel; Dallaire, François; Tardif, Jean-Claude; Merhi, Yahye; Sorci-Thomas, Mary; Martel, Catherine

    2017-09-22

    Subcutaneously injected lipid-free apoA-I (apolipoprotein A-I) reduces accumulation of lipid and immune cells within the aortic root of hypercholesterolemic mice without increasing high-density lipoprotein-cholesterol concentrations. Lymphatic vessels are now recognized as prerequisite players in the modulation of cholesterol removal from the artery wall in experimental conditions of plaque regression, and particular attention has been brought to the role of the collecting lymphatic vessels in early atherosclerosis-related lymphatic dysfunction. In the present study, we address whether and how preservation of collecting lymphatic function contributes to the protective effect of apoA-I. Atherosclerotic Ldlr(-/-) mice treated with low-dose lipid-free apoA-I showed enhanced lymphatic transport and abrogated collecting lymphatic vessel permeability in atherosclerotic Ldlr(-/-) mice when compared with albumin-control mice. Treatment of human lymphatic endothelial cells with apoA-I increased the adhesion of human platelets on lymphatic endothelial cells, in a bridge-like manner, a mechanism that could strengthen endothelial cell-cell junctions and limit atherosclerosis-associated collecting lymphatic vessel dysfunction. Experiments performed with blood platelets isolated from apoA-I-treated Ldlr(-/-) mice revealed that apoA-I decreased ex vivo platelet aggregation. This suggests that in vivo apoA-I treatment limits platelet thrombotic potential in blood while maintaining the platelet activity needed to sustain adequate lymphatic function. Altogether, we bring forward a new pleiotropic role for apoA-I in lymphatic function and unveil new potential therapeutic targets for the prevention and treatment of atherosclerosis. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

  16. Proteolysis of Apolipoprotein A-I by Secretory Phospholipase A2

    PubMed Central

    Cavigiolio, Giorgio; Jayaraman, Shobini

    2014-01-01

    In the acute phase of the inflammatory response, secretory phospholipase A2 (sPLA2) reaches its maximum levels in plasma, where it is mostly associated with high density lipoproteins (HDL). Overexpression of human sPLA2 in transgenic mice reduces both HDL cholesterol and apolipoprotein A-I (apoA-I) plasma levels through increased HDL catabolism by an unknown mechanism. To identify unknown PLA2-mediated activities on the molecular components of HDL, we characterized the protein and lipid products of the PLA2 reaction with HDL. Consistent with previous studies, hydrolysis of HDL phospholipids by PLA2 reduced the particle size without changing its protein composition. However, when HDL was destabilized in the presence of PLA2 by the action of cholesteryl ester transfer protein or by guanidine hydrochloride treatment, a fraction of apoA-I, but no other proteins, dissociated from the particle and was rapidly cleaved. Incubation of PLA2 with lipid-free apoA-I produced similar protein fragments in the range of 6–15 kDa, suggesting specific and direct reaction of PLA2 with apoA-I. Mass spectrometry analysis of isolated proteolytic fragments indicated at least two major cleavage sites at the C-terminal and the central domain of apoA-I. ApoA-I proteolysis by PLA2 was Ca2+-independent, implicating a different mechanism from the Ca2+-dependent PLA2-mediated phospholipid hydrolysis. Inhibition of proteolysis by benzamidine suggests that the proteolytic and lipolytic activities of PLA2 proceed through different mechanisms. Our study identifies a previously unknown proteolytic activity of PLA2 that is specific to apoA-I and may contribute to the enhanced catabolism of apoA-I in inflammation and atherosclerosis. PMID:24523407

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

    PubMed

    Duggan, A E; Callard, I P

    2001-08-01

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

  18. Francisella tularensis subsp. tularensis Group A.I, United States

    PubMed Central

    Birdsell, Dawn N.; Johansson, Anders; Öhrman, Caroline; Kaufman, Emily; Molins, Claudia; Pearson, Talima; Gyuranecz, Miklós; Naumann, Amber; Vogler, Amy J.; Myrtennäs, Kerstin; Larsson, Pär; Forsman, Mats; Sjödin, Andreas; Gillece, John D.; Schupp, James; Petersen, Jeannine M.; Keim, Paul

    2014-01-01

    We used whole-genome analysis and subsequent characterization of geographically diverse strains using new genetic signatures to identify distinct subgroups within Francisella tularensis subsp. tularensis group A.I: A.I.3, A.I.8, and A.I.12. These subgroups exhibit complex phylogeographic patterns within North America. The widest distribution was observed for A.I.12, which suggests an adaptive advantage. PMID:24755401

  19. Serum apolipoproteins A-I and B in 2,854 children from a biracial community: Bogalusa Heart Study.

    PubMed

    Srinivasan, S R; Freedman, D S; Sharma, C; Webber, L S; Berenson, G S

    1986-08-01

    Serum apolipoprotein A-I (apo A-I) and apolipoprotein B (apo B) profiles were examined in 2,854 children, 5 to 17 years of age, from a total biracial community. Black boys had higher apo A-I levels than white boys (P less than .001), whereas girls showed no such race-related difference. Black-white difference in apo A-I persisted among boys with similar triglyceride levels provided that triglyceride levels were high. The ratio of high-density lipoprotein cholesterol (HDL-C)/apo A-I was higher in black than in white children, irrespective of sex (P less than .001). Only black children showed sex-related differences for apo A-I (boys greater than girls, P less than .05). Sex-related differences were seen in white children for HDL-C/apo A-I ratio (boys greater than girls, P less than .001) and in children of both races for apoB (girls greater than boys, P less than .01). Age-related changes were more apparent for apo A-I and HDL-C/apo A-I ratio than for apo B. A progressive decrease in apo A-I was noted during sexual maturation only in white boys. The magnitude of inverse association of apo B to HDL-C was less strong in black children (P less than .01). Although apo A-I was inversely correlated with very low-density lipoprotein cholesterol and triglycerides in white children, no association was noted in black children. These findings are indicative of intrinsic metabolic differences among the race-sex groups, resulting in variability in lipoprotein composition and levels and atherogenic potential.

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

    PubMed

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

    2016-08-01

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

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

    PubMed Central

    Yao, Xianglan; Gordon, Elizabeth M.; Figueroa, Debbie M.; Barochia, Amisha V.

    2016-01-01

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

  2. Safe and sustained overexpression of functional apolipoprotein A-I/high-density lipoprotein in apolipoprotein A-I-null mice by muscular adeno-associated viral serotype 8 vector gene transfer.

    PubMed

    Cimmino, Giovanni; Chen, Wei; Speidl, Walter S; Giannarelli, Chiara; Ibanez, Borja; Fuster, Valentin; Hajjar, Roger; Walsh, Christopher E; Badimon, Juan J

    2009-11-01

    High levels of high-density lipoprotein (HDL) have protective effects against atherosclerosis and cardiovascular diseases. The postulated mechanism of action for these benefits is an enhanced reverse cholesterol transport. Apolipoprotein A-I (ApoA-I) is the major protein of HDL. The clinical benefits of raising ApoA-I/HDL have been clearly established by clinical and epidemiological studies. Despite these observations, there are not very effective pharmacological means for raising HDL. ApoA-I gene delivery by viral vectors seems a promising strategy to raise ApoA-I/HDL levels. Sustained gene expression in animals and humans has been attained using adeno-associated viral (AAV) vectors. The aim of the present study was to determine the efficiency, safety, and biological activity of human ApoA-I intramuscularly delivered using an AAV vector in mice. AAV serotype 8 vectors encoding for human ApoA-I transgene were administered intraportally and intramuscularly in ApoA-I- deficient animals. ApoA-I levels were measured every 2 weeks post administration. The effectiveness of the generated HDL was tested in vitro in cholesterol-loaded macrophages. The administration of the vectors resulted in a significant and sustained increase in ApoA-I and HDL plasma levels for up to 16 weeks at similar extent by both routes of administration. Activity of the generated HDL in removal of cholesterol from cholesterol-loaded macrophages was similar in both groups. Our data suggest that intramuscular AAV8-mediated gene transfer of human ApoA-I results in a significant and maintained increase in ApoA-I and functional HDL.

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

    USDA-ARS?s Scientific Manuscript database

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

  4. Effect of body mass index on apolipoprotein A-I kinetics in middle-aged men and postmenopausal women.

    PubMed

    Welty, Francine K; Lichtenstein, Alice H; Lamon-Fava, Stefania; Schaefer, Ernst J; Marsh, Julian B

    2007-07-01

    The effect of body mass index (BMI) and obesity on apolipoprotein (apo) A-I levels and kinetics was examined by gender. Apo A-I kinetics were determined with a primed, constant infusion of deuterated leucine in the fed state in 19 men and 13 postmenopausal women. Compared with nonobese men, nonobese women had a higher level of high-density lipoprotein cholesterol (HDL-C) and apo A-I due to a 48% higher apo A-I production rate (PR) (P = .05). Obesity had no significant effects on apo A-I kinetics in women. In contrast, compared with nonobese men, obese men had a 9% lower apo A-I level due to a 64% higher fractional catabolic rate (FCR) partially offset by a 47% higher PR. Obese women had a 52% higher HDL-C than obese men (50 vs 33 mg/dL, respectively; P = .012), a finding related to the faster apo A-I FCR in obese men. BMI was directly correlated with apo A-I FCR (r = 0.84, P < .001) and PR (r = 0.79, P < .001) in men but not in women. Sixty-two percent of the variability in PR and 71% of the variability in FCR were due to BMI in men and only 3% and 23%, respectively, in women. In conclusion, BMI has a significant effect on apo A-I PR and FCR in men but not in women.

  5. Apolipoprotein A-I Limits the Negative Effect of Tumor Necrosis Factor on Lymphangiogenesis.

    PubMed

    Bisoendial, Radjesh; Tabet, Fatiha; Tak, Paul P; Petrides, Francine; Cuesta Torres, Luisa F; Hou, Liming; Cook, Adam; Barter, Philip J; Weninger, Wolfgang; Rye, Kerry-Anne

    2015-11-01

    Lymphatic endothelial dysfunction underlies the pathogenesis of many chronic inflammatory disorders. The proinflammatory cytokine tumor necrosis factor (TNF) is known for its role in disrupting the function of the lymphatic vasculature. This study investigates the ability of apolipoprotein (apo) A-I, the principal apolipoprotein of high-density lipoproteins, to preserve the normal function of lymphatic endothelial cells treated with TNF. TNF decreased the ability of lymphatic endothelial cells to form tube-like structures. Preincubation of lymphatic endothelial cells with apoA-I attenuated the TNF-mediated inhibition of tube formation in a concentration-dependent manner. In addition, apoA-I reversed the TNF-mediated suppression of lymphatic endothelial cell migration and lymphatic outgrowth in thoracic duct rings. ApoA-I also abrogated the negative effect of TNF on lymphatic neovascularization in an ATP-binding cassette transporter A1-dependent manner. At the molecular level, this involved downregulation of TNF receptor-1 and the conservation of prospero-related homeobox gene-1 expression, a master regulator of lymphangiogenesis. ApoA-I also re-established the normal phenotype of the lymphatic network in the diaphragms of human TNF transgenic mice. ApoA-I restores the neovascularization capacity of the lymphatic system during TNF-mediated inflammation. This study provides a proof-of-concept that high-density lipoprotein-based therapeutic strategies may attenuate chronic inflammation via its action on lymphatic vasculature. © 2015 American Heart Association, Inc.

  6. Thermal Stability of Apolipoprotein A-I in High-Density Lipoproteins by Molecular Dynamics

    PubMed Central

    Jones, Martin K.; Catte, Andrea; Patterson, James C.; Gu, Feifei; Chen, Jianguo; Li, Ling; Segrest, Jere P.

    2009-01-01

    Abstract Apolipoprotein (apo) A-I is an unusually flexible protein whose lipid-associated structure is poorly understood. Thermal denaturation, which is used to measure the global helix stability of high-density lipoprotein (HDL)-associated apoA-I, provides no information about local helix stability. Here we report the use of temperature jump molecular dynamics (MD) simulations to scan the per-residue helix stability of apoA-I in phospholipid-rich HDL. When three 20 ns MD simulations were performed at 500 K on each of two particles created by MD simulations at 310 K, bilayers remained intact but expanded by 40%, and total apoA-I helicity decreased from 95% to 72%. Of significance, the conformations of the overlapping N- and C-terminal domains of apoA-I in the particles were unusually mobile, exposing hydrocarbon regions of the phospholipid to solvent; a lack of buried interhelical salt bridges in the terminal domains correlated with increased mobility. Nondenaturing gradient gels show that 40% expansion of the phospholipid surface of 100:2 particles by addition of palmitoyloleoylphosphatidylcholine exceeds the threshold of particle stability. As a unifying hypothesis, we propose that the terminal domains of apoA-I are phospholipid concentration-sensitive molecular triggers for fusion/remodeling of HDL particles. Since HDL remodeling is necessary for cholesterol transport, our model for remodeling has substantial biomedical implications. PMID:19167289

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

    PubMed Central

    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

  8. A mass spectrometric determination of the conformation of dimeric apolipoprotein A-I in discoidal high density lipoproteins.

    PubMed

    Silva, R A Gangani D; Hilliard, George M; Li, Ling; Segrest, Jere P; Davidson, W Sean

    2005-06-21

    Discoidal forms of high density lipoproteins (HDL) are critical intermediates between lipid-poor apolipoprotein A-I (apo A-I), the major protein constituent of HDL, and the mature spherical forms that comprise the bulk of circulating particles. Thus, many studies have focused on understanding apoA-I structure in discs reconstituted in vitro. Recent theoretical and experimental work supports a "belt" model for apoA-I in which repeating amphipathic helical domains run parallel to the plane of the lipid disc. However, disc-associated apoA-I can adopt several tertiary arrangements that are consistent with a belt orientation. To distinguish among these, we cross-linked near-neighbor Lys groups in homogeneous 96 A discs containing exactly two molecules of apoA-I. After delipidation and tryptic digestion, mass spectrometry was used to identify 9 intermolecular and 11 intramolecular cross-links. The cross-linking pattern strongly suggests a "double-belt" molecular arrangement for apoA-I in which two apoA-I molecules wrap around the lipid bilayer disc forming two stacked rings in an antiparallel orientation with helix 5 of each apoA-I in juxtaposition (LL5/5 orientation). The data also suggests the presence of an additional double-belt orientation with a shifted helical registry (LL5/2 orientation). Furthermore, a 78 A particle with two molecules of apoA-I fit a similar double-belt motif with evidence for conformational changes in the N-terminus and the region near helix 5. A comparison of this work to a previous study is suggestive that a third molecule of apoA-I can form a hairpin in larger particles containing three molecules of apoA-I.

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

    PubMed

    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.

  10. Apolipoprotein A-I Is a Potential Mediator of Remote Ischemic Preconditioning

    PubMed Central

    Hibert, Pierre; Prunier-Mirebeau, Delphine; Beseme, Olivia; Chwastyniak, Maggy; Tamareille, Sophie; Lamon, Delphine; Furber, Alain; Pinet, Florence; Prunier, Fabrice

    2013-01-01

    Background Remote ischemic preconditioning (RIPC) has emerged as an attractive strategy in clinical settings. Despite convincing evidence of the critical role played by circulating humoral mediators, their actual identities remain unknown. In this study, we aimed to identify RIPC-induced humoral mediators using a proteomic approach. Methods and Results Rats were exposed to 10-min limb ischemia followed by 5- (RIPC 5′) or 10-min (RIPC 10′) reperfusion prior to blood sampling. The control group only underwent blood sampling. Plasma samples were analyzed using surface-enhanced laser desorption and ionization - time of flight - mass spectrometry (SELDI-TOF-MS). Three protein peaks were selected for their significant increase in RIPC 10′. They were identified and confirmed as apolipoprotein A-I (ApoA-I). Additional rats were exposed to myocardial ischemia-reperfusion (I/R) and assigned to one of the following groups RIPC+myocardial infarction (MI) (10-min limb ischemia followed by 10-min reperfusion initiated 20 minutes prior to myocardial I/R), ApoA-I+MI (10 mg/kg ApoA-I injection 10 minutes before myocardial I/R), and MI (no further intervention). In comparison with untreated MI rats, RIPC reduced infarct size (52.2±3.7% in RIPC+MI vs. 64.9±2.6% in MI; p<0.05). Similarly, ApoA-I injection decreased infarct size (50.9±3.8%; p<0.05 vs. MI). Conclusions RIPC was associated with a plasmatic increase in ApoA-I. Furthermore, ApoA-I injection before myocardial I/R recapitulated the cardioprotection offered by RIPC in rats. This data suggests that ApoA-I may be a protective blood-borne factor involved in the RIPC mechanism. PMID:24155931

  11. Definition of human apolipoprotein A-I epitopes recognized by autoantibodies present in patients with cardiovascular diseases.

    PubMed

    Teixeira, Priscila Camillo; Ducret, Axel; Ferber, Philippe; Gaertner, Hubert; Hartley, Oliver; Pagano, Sabrina; Butterfield, Michelle; Langen, Hanno; Vuilleumier, Nicolas; Cutler, Paul

    2014-10-10

    Autoantibodies to apolipoprotein A-I (anti-apoA-I IgG) have been shown to be both markers and mediators of cardiovascular disease, promoting atherogenesis and unstable atherosclerotic plaque. Previous studies have shown that high levels of anti-apoA-I IgGs are independently associated with major adverse cardiovascular events in patients with myocardial infarction. Autoantibody responses to apoA-I can be polyclonal and it is likely that more than one epitope may exist. To identify the specific immunoreactive peptides in apoA-I, we have developed a set of methodologies and procedures to isolate, purify, and identify novel apoA-I endogenous epitopes. First, we generated high purity apoA-I from human plasma, using thiophilic interaction chromatography followed by enzymatic digestion specifically at lysine or arginine residues. Immunoreactivity to the different peptides generated was tested by ELISA using serum obtained from patients with acute myocardial infarction and high titers of autoantibodies to native apoA-I. The immunoreactive peptides were further sequenced by mass spectrometry. Our approach successfully identified two novel immunoreactive peptides, recognized by autoantibodies from patients suffering from myocardial infarction, who contain a high titer of anti-apoA-I IgG. The discovery of these epitopes may open innovative prognostic and therapeutic opportunities potentially suitable to improve current cardiovascular risk stratification.

  12. Expression and purification of recombinant apolipoprotein A-I Zaragoza (L144R) and formation of reconstituted HDL particles.

    PubMed

    Fiddyment, Sarah; Barceló-Batllori, Sílvia; Pocoví, Miguel; García-Otín, Angel-Luis

    2011-11-01

    Apolipoprotein A-I Zaragoza (L144R) (apo A-I Z), has been associated with severe hypoalphalipoproteinemia and an enhanced effect of high density lipoprotein (HDL) reverse cholesterol transport. In order to perform further studies with this protein we have optimized an expression and purification method of recombinant wild-type apo A-I and apo A-I Z and produced mimetic HDL particles with each protein. An pET-45 expression system was used to produce N-terminal His-tagged apo A-I, wild-type or mutant, in Escherichia coli BL21 (DE3) which was subsequently purified by affinity chromatography in non-denaturing conditions. HDL particles were generated via a modified sodium cholate method. Expression and purification of both proteins was verified by SDS-PAGE, MALDI-TOF MS and immunochemical procedures. Yield was 30mg of purified protein (94% purity) per liter of culture. The reconstituted HDL particles checked via non-denaturing PAGE showed high homogeneity in their size when reconstituted both with wild-type apo A-I and apo A-I Z. An optimized system for the expression and purification of wild-type apo A-I and apo A-I Z with high yield and purity grade has been achieved, in addition to their use in reconstituted HDL particles, as a basis for further studies.

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

    PubMed

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

    2015-02-03

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

  14. Effect of Body Mass Index on Apolipoprotein A-I Kinetics in Middle-Aged Men and Postmenopausal Women

    PubMed Central

    Welty, Francine K.; Lichtenstein, Alice H.; Lamon-Fava, Stefania; Schaefer, Ernst J.; Marsh, Julian B.

    2009-01-01

    The effect of body mass index (BMI) and obesity on apo A-I levels and kinetics was examined by gender. ApoA-I kinetics were determined with a primed-constant infusion of deuterated leucine in the fed state in 19 men and 13 postmenopausal women. Compared to nonobese men, nonobese women had a higher HDL-C and apoA-I level due to a 48% higher apoA-I PR (p=0.05). Obesity had no significant effects on apoA-I kinetics in women. In contrast, compared to non-obese men, obese men had a 9% lower apoA-I level due to a 64% higher FCR partially offset by a 47% higher PR. Obese women had a 52% higher HDL-C than obese men (50 mg/dL vs 33 mg/dL, respectively, p=0.012), a finding related to the faster apoA-I FCR in obese men. BMI was directly correlated with apoA-1 FCR (r = 0.84, p < 0.001) and PR (r = 0.79, p < 0.001) in men but not women. 62% of the variability in PR and 71% of the variability in FCR were due to BMI in men and only 3% and 23%, respectively, in women. In conclusion, BMI has a significant effect on apoA-I PR and FCR in men but not in women. PMID:17570251

  15. Concentration and pattern changes of porcine serum apolipoprotein A-I in four different infectious diseases.

    PubMed

    Marco-Ramell, Anna; Hummel, Karin; Razzazi-Fazeli, Ebrahim; Bassols, Anna; Miller, Ingrid

    2015-02-01

    Apolipoprotein A-I (Apo A-I) is a major protein in lipid/lipoprotein metabolism and decreased serum levels have been observed in many species in response to inflammatory and infectious challenges. Little is known about the porcine homologue, therefore in this work we have characterized it through biochemical and proteomic techniques. In 2DE, porcine serum Apo A-I is found as three spots, the two more acidic ones corresponding to the mature protein, the more basic spot to the protein precursor. Despite high sequence coverage in LC-MS/MS, we did not find a sequence or PTM difference between the two mature protein species. Besides this biochemical characterization, we measured overall levels and relative species abundance of serum Apo A-I in four different viral and bacterial porcine infectious diseases. Lower overall amounts of Apo A-I were observed in Salmonella typhimurium and Escherichia coli infections. In the 2DE protein pattern, an increase of the protein precursor together with a lower level of mature protein species were detected in the porcine circovirus type 2-systemic disease and S. typhimurium infection. These results reveal that both the porcine serum Apo A-I concentration and the species pattern are influenced by the nature of the infectious disease. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Human Apolipoprotein A-I-Derived Amyloid: Its Association with Atherosclerosis

    PubMed Central

    Ramella, Nahuel A.; Rimoldi, Omar J.; Prieto, Eduardo D.; Schinella, Guillermo R.; Sanchez, Susana A.; Jaureguiberry, María S.; Vela, María E.

    2011-01-01

    Amyloidoses constitute a group of diseases in which soluble proteins aggregate and deposit extracellularly in tissues. Nonhereditary apolipoprotein A-I (apoA-I) amyloid is characterized by deposits of nonvariant protein in atherosclerotic arteries. Despite being common, little is known about the pathogenesis and significance of apoA-I deposition. In this work we investigated by fluorescence and biochemical approaches the impact of a cellular microenvironment associated with chronic inflammation on the folding and pro-amyloidogenic processing of apoA-I. Results showed that mildly acidic pH promotes misfolding, aggregation, and increased binding of apoA-I to extracellular matrix elements, thus favoring protein deposition as amyloid like-complexes. In addition, activated neutrophils and oxidative/proteolytic cleavage of the protein give rise to pro amyloidogenic products. We conclude that, even though apoA-I is not inherently amyloidogenic, it may produce non hereditary amyloidosis as a consequence of the pro-inflammatory microenvironment associated to atherogenesis. PMID:21811627

  17. Blood serum apolipoproteins B and A-I in females suffering from rheumatic heart valve disease.

    PubMed

    Stakisaitis, Donatas; Maksvytis, Arūnas; Salcius, Kestutis; Benetis, Rimantas

    2004-01-01

    With the aim to check whether the atherogenic factors are involved in the mechanisms of valve fibrosis, we have studied the blood serum concentrations of apolipoproteins (apo) A-I and B concentration in patients suffering from rheumatic heart valve fibrosis. The quantities of apoA-I and apoB in the blood serum were tested by the ELISA method. Concentration of apoA-I and B in the blood serum was determined in rheumatic females with replacement of the damaged valves: after aortic valve operation (n=11; mean age 43.3+/-3.6 years) and after mitral valve operation (n=29; 41.3+/-4.1). The results obtained for rheumatic patients were compared with the data on age-matched healthy females (n=43; 39.5+/-5.2 years). Significantly lower apoA-I level in the blood serum of all patients suffering from rheumatic heart valve disease was determined as compared with controls: in the pooled group of patients (1.02+/-0.22 vs 1.23+/-0.23 g/l, P<0.001), in women after aortic valve replacement (0.98+/-0.21 vs. 1.23+/-0.23 g/l, P<0.005), and in women after mitral valve surgery (1.03+/-0.23 g/l vs 1.23+/-0.23 g/l, P<0.005). The apoB level in patients suffering from rheumatic heart valve disease did not differ from that of controls. The apoB/apoA-I ratio for patients with valve fibrotic damage was significantly higher as compared to controls in all groups (P<0.02). The increase of apoB/apoA-I ratio in patients with rheumatic valve fibrosis was caused by lower apoA-I levels in blood serum. The obtained results indicate that decreased apoA-I levels in blood serum can be indicative of valve fibrosis in rheumatic heart valve disease patients.

  18. A fast semi-quantitative LC-MS method for measurement of intact apolipoprotein A-I reveals novel proteoforms in serum.

    PubMed

    Gåfvels, M; Bengtson, P

    2015-03-10

    Surrogate markers for reverse cholesterol transport (RCT) efficiency such as HDL cholesterol and immune methods for apolipoprotein A-I (ApoA-I) may not fully reflect the actual efficiency of the RCT pathway. Several genetic variants and different posttranslational proteoforms of ApoA-I may unevenly affect the functionality of the HDL particle to efflux cholesterol. A method employing top-down immunoaffinity LC-MS of ApoA-I in order to characterize the most prevalent ApoA-I proteoforms in human plasma is described. Diluted plasma was directly injected into a 2D LC-MS system consisting of an affinity column and an analytical column. Enriched ApoA-I fractions were introduced into the MS and intact or fragmented ApoA-I was analyzed. ApoA-I as detected by the described LC-MS method distributes into at least 14 major potential proteoforms exceeding detection limit in human plasma. Substantial amounts of ApoA-I in plasma were found to occur as truncated, oxidized, glycated and glycosylated proteoforms. Levels of glycated ApoA-I distinguished significantly diabetic from non-diabetic samples. In addition novel truncated and glycosylated proteoforms were detected. ApoA-I proteoforms measured by LC-MS represent a useful approach to augment the clinical picture of ApoA-I and its function in health and disease. Copyright © 2015 Elsevier B.V. All rights reserved.

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

    PubMed

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

    2013-05-01

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

  20. Enthalpy-driven apolipoprotein A-I and lipid bilayer interaction indicating protein penetration upon lipid binding.

    PubMed

    Arnulphi, Cristina; Jin, Lihua; Tricerri, M Alejandra; Jonas, Ana

    2004-09-28

    The interaction of lipid-free apolipoprotein A-I (apoA-I) with small unilamellar vesicles (SUVs) of 1-palmitoyl-2-oleoylphosphatidylcholine (POPC) with and without free cholesterol (FC) was studied by isothermal titration calorimetry and circular dichroism spectroscopy. Parameters reported are the affinity constant (K(a)), the number of protein molecules bound per vesicle (n), enthalpy change (DeltaH degrees), entropy change (DeltaS degrees ), and the heat capacity change (DeltaC(p) degrees). The binding process of apoA-I to SUVs of POPC plus 0-20% (mole) FC was exothermic between 15 and 37 degrees C studied, accompanied by a small negative entropy change, making enthalpy the main driving force of the interaction. The presence of cholesterol in the vesicles increased the binding affinity and the alpha-helix content of apoA-I but lowered the number of apoA-I bound per vesicle and the enthalpy and entropy changes per bound apoA-I. Binding affinity and stoichiometry were essentially invariant of temperature for binding to SUVs of POPC/FC at a molar ratio of 6/1 at (2.8-4) x 10(6) M(-1) and 2.4 apoA-I molecules bound per vesicle or 1.4 x 10(2) phospholipids per bound apoA-I. A plot of DeltaH degrees against temperature displayed a linear behavior, from which the DeltaC(p) degrees per mole of bound apoA-I was calculated to be -2.73 kcal/(mol x K). These results suggested that binding of apoA-I to POPC vesicles is characterized by nonclassical hydrophobic interactions, with alpha-helix formation as the main driving force for the binding to cholesterol-containing vesicles. In addition, comparison to literature data on peptides suggested a cooperativity of the helices in apoA-I in lipid interaction.

  1. Abdominal obesity with hypertriglyceridaemia, lipoprotein(a) and apolipoprotein A-I determine marked cardiometabolic risk.

    PubMed

    Onat, Altan; Can, Günay; Örnek, Ender; Sansoy, Vedat; Aydın, Mesut; Yüksel, Hüsniye

    2013-11-01

    Risks for coronary heart disease (CHD) and diabetes (T2DM) of the 'hypertriglyceridemic waist' phenotype (HtgW) warrant further investigation. We studied this issue and whether partial proinflammatory conversion of apolipoprotein (apo) A-I by lipoprotein(a) [Lp(a)] is a codeterminant. In a population-based prospective study, 1328 Turkish adults were analysed in four groups by the presence of abdominal obesity and elevated triglycerides (Htg). LDL-cholesterol levels, significantly elevated in isolated Htg, were lower in HtgW, yet significantly higher apoB and complement C3 values existed in women with HtgW in whom also the lowest Lp(a) values prevailed. Lp(a) was linearly associated, more strongly in HtgW than in the remaining groups, with apoB and, in women inversely, with gamma-glutamyltransferase. Incident HtgW was predicted, not in men, but in women inversely by Lp(a) (OR 0.80 [95%CI 0.65; 0.97]), regardless of adjustment for relevant confounders. After adjustment for conventional risk factors, HtgW (OR 2.84) and high apoA-I/HDL-C ratio (OR 1.50) were significantly and additively associated with combined prevalent and incident CHD risk. High apoA-I and low HDL-cholesterol levels interacted therein in women. Type-2 diabetes was strongly predicted by HtgW, mediated in men by high apoA-I/HDL-C ratio. HtgW is associated with excess inflammatory markers, is predicted in women paradoxically by lower circulating Lp(a) and is associated in both sexes with marked excess cardiometabolic risk to which high apoA-I/HDL-C ratio contributes additively. These findings are consistent in women with apoA-I being oxidized via aggregation to Lp(a). © 2013 Stichting European Society for Clinical Investigation Journal Foundation. Published by John Wiley & Sons Ltd.

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

    PubMed

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

    2016-05-12

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

  3. HDL-apolipoprotein A-I exchange is independently associated with cholesterol efflux capacity

    PubMed Central

    Borja, Mark S.; Ng, Kit F.; Irwin, Angela; Hong, Jaekyoung; Wu, Xing; Isquith, Daniel; Zhao, Xue-Qiao; Prazen, Bryan; Gildengorin, Virginia; Oda, Michael N.; Vaisar, Tomáš

    2015-01-01

    HDL is the primary mediator of cholesterol mobilization from the periphery to the liver via reverse cholesterol transport (RCT). A critical first step in this process is the uptake of cholesterol from lipid-loaded macrophages by HDL, a function of HDL inversely associated with prevalent and incident cardiovascular disease. We hypothesized that the dynamic ability of HDL to undergo remodeling and exchange of apoA-I is an important and potentially rate-limiting aspect of RCT. In this study, we investigated the relationship between HDL-apoA-I exchange (HAE) and serum HDL cholesterol (HDL-C) efflux capacity. We compared HAE to the total and ABCA1-specific cholesterol efflux capacity of 77 subjects. We found that HAE was highly correlated with both total (r = 0.69, P < 0.0001) and ABCA1-specific (r = 0.47, P < 0.0001) efflux, and this relationship remained significant after adjustment for HDL-C or apoA-I. Multivariate models of sterol efflux capacity indicated that HAE accounted for approximately 25% of the model variance for both total and ABCA1-specific efflux. We conclude that the ability of HDL to exchange apoA-I and remodel, as measured by HAE, is a significant contributor to serum HDL efflux capacity, independent of HDL-C and apoA-I, indicating that HDL dynamics are an important factor in cholesterol efflux capacity and likely RCT. PMID:26254308

  4. Crystal Structure of Δ(185–243)apoA-I Suggests a Mechanistic Framework for the Protein Adaptation to the Changing Lipid Load in Good Cholesterol: From Flatland to Sphereland via Double Belt, Belt-Buckle, Double Hairpin and Trefoil/Tetrafoil

    PubMed Central

    Gursky, Olga

    2012-01-01

    ApoA-I is the major protein of plasma high-density lipoproteins (HDL), macromolecular assemblies of proteins and lipids that remove cell cholesterol and protect against atherosclerosis. HDL heterogeneity, large size (7.7–12 nm) and ability to exchange proteins have prevented high-resolution structural analysis. Low-resolution studies showed that two apoA-I molecules form an antiparallel α-helical “double belt” around an HDL particle. Atomic-resolution structure of the C-terminal truncated lipid-free Δ(185–243)apoA-I, determined recently by Mei and Atkinson, provides unprecedented new insights into HDL structure-function. It allows us to propose a molecular mechanism for the adaptation of the full-length protein to increasing lipid load during cholesterol transport. ApoA-I conformations on the small, mid-size and large HDL are proposed based on the tandem α-helical repeats and the crystal structure of Δ(185–243)apoA-I, and are validated by comparison with extensive biophysical data reported by many groups. In our models, the central half of the double belt (“constant” segment 66–184) is structurally conserved while the N- and C-terminal half (“variable” segments 1–65 and 185–243) re-arranges upon HDL growth. This includes incremental unhinging of the N-terminal bundle around two flexible regions containing G39 and G65 to elongate the belt, along with concerted swing motion of the double belt around G65-P66 and G185–G186 hinges that are aligned on various-size particles, to confer 2D surface curvature to spherical HDL. The proposed conformational ensemble integrates and improves several existing HDL models. It helps provide a structural framework necessary to understand functional interactions with over 60 other HDL-associated proteins and, ultimately, improve cardioprotective function of HDL. PMID:23041415

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

    PubMed

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

    2016-01-01

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

  6. A novel truncated form of apolipoprotein A-I transported by dense LDL is increased in diabetic patients1[S

    PubMed Central

    Cubedo, Judit; Padró, Teresa; García-Arguinzonis, Maisa; Vilahur, Gemma; Miñambres, Inka; Pou, Jose María; Ybarra, Juan; Badimon, Lina

    2015-01-01

    Diabetic (DM) patients have exacerbated atherosclerosis and high CVD burden. Changes in lipid metabolism, lipoprotein structure, and dysfunctional HDL are characteristics of diabetes. Our aim was to investigate whether serum ApoA-I, the main protein in HDL, was biochemically modified in DM patients. By using proteomic technologies, we have identified a 26 kDa ApoA-I form in serum. MS analysis revealed this 26 kDa form as a novel truncated variant lacking amino acids 1-38, ApoA-IΔ(1-38). DM patients show a 2-fold increase in ApoA-IΔ(1-38) over nondiabetic individuals. ApoA-IΔ(1-38) is found in LDL, but not in VLDL or HDL, with an increase in LDL3 and LDL4 subfractions. To identify candidate mechanisms of ApoA-I truncation, we investigated potentially involved enzymes by in silico data mining, and tested the most probable molecule in an established animal model of diabetes. We have found increased hepatic cathepsin D activity as one of the potential proteases involved in ApoA-I truncation. Cathepsin D-cleaved ApoA-I exhibited increased LDL binding affinity and decreased antioxidant activity against LDL oxidation. In conclusion, we show for the first time: a) presence of a novel truncated ApoA-I form, ApoA-IΔ(1-38), in human serum; b) ApoA-IΔ(1-38) is transported by LDL; c) ApoA-IΔ(1-38) is increased in dense LDL fractions of DM patients; and d) cathepsin D-ApoA-I truncation may lead to ApoA-IΔ(1-38) binding to LDLs, increasing their susceptibility to oxidation and contributing to the high cardiovascular risk of DM patients. PMID:26168996

  7. High-Density Lipoprotein Biogenesis: Defining the Domains Involved in Human Apolipoprotein A-I Lipidation.

    PubMed

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

    2016-09-06

    The first step in removing cholesterol from a cell is the ATP-binding cassette transporter 1 (ABCA1)-driven transfer of cholesterol to lipid-free or lipid-poor apolipoprotein A-I (apoA-I), which yields cholesterol-rich nascent high-density lipoprotein (nHDL) that then matures in plasma to spherical, cholesteryl ester-rich HDL. However, lipid-free apoA-I has a three-dimensional (3D) conformation that is significantly different from that of lipidated apoA-I on nHDL. By comparing the lipid-free apoA-I 3D conformation of apoA-I to that of 9-14 nm diameter nHDL, we formulated the hypothetical helical domain transitions that might drive particle formation. To test the hypothesis, ten apoA-I mutants were prepared that contained two strategically placed cysteines several of which could form intramolecular disulfide bonds and others that could not form these bonds. Mass spectrometry was used to identify amino acid sequence and intramolecular disulfide bond formation. Recombinant HDL (rHDL) formation was assessed with this group of apoA-I mutants. ABCA1-driven nHDL formation was measured in four mutants and wild-type apoA-I. The mutants contained cysteine substitutions in one of three regions: the N-terminus, amino acids 34 and 55 (E34C to S55C), central domain amino acids 104 and 162 (F104C to H162C), and the C-terminus, amino acids 200 and 233 (L200C to L233C). Mutants were studied in the locked form, with an intramolecular disulfide bond present, or unlocked form, with the cysteine thiol blocked by alkylation. Only small amounts of rHDL or nHDL were formed upon locking the central domain. We conclude that both the N- and C-terminal ends assist in the initial steps in lipid acquisition, but that opening of the central domain was essential for particle formation.

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

    PubMed

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

    2016-08-01

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

  9. 12 CFR Appendixes A-I to Part 171 - [Reserved

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 12 Banks and Banking 1 2013-01-01 2013-01-01 false A Appendixes A-I to Part 171 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY FAIR CREDIT REPORTING Appendixes A-I to Part 171 ...

  10. 12 CFR Appendixes A-I to Part 171 - [Reserved

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 12 Banks and Banking 1 2012-01-01 2012-01-01 false A Appendixes A-I to Part 171 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY FAIR CREDIT REPORTING Appendixes A-I to Part 171 ...

  11. 12 CFR Appendixes A-I to Part 171 - [Reserved

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 1 2014-01-01 2014-01-01 false A Appendixes A-I to Part 171 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY FAIR CREDIT REPORTING Appendixes A-I to Part 171 ...

  12. In situ AFM imaging of apolipoprotein A-I directly derived from plasma HDL.

    PubMed

    Gan, Chaoye; Wang, Zhexuan; Chen, Yong

    2017-04-01

    The major apolipoproteins of plasma lipoproteins play vital roles in the structural integrity and physiological functions of lipoproteins. More than ten structural models of apolipoprotein A-I (apoA-I), the major apolipoprotein of high-density lipoprotein (HDL), have been developed successively. In these models, apoA-I was supposed to organize in a ring-shaped form. To date, however, there is no direct evidence under physiological condition. Here, atomic force microscopy (AFM) was used to in situ visualize the organization of apoA-I, which was exposed via depletion of the lipid component of plasma HDL pre-immobilized on functionalized mica sheets. For the first time, the ring-shaped coarse structure and three detailed structures (crescent-shaped, gapped "O"-shaped, and parentheses-shaped structures, respectively) of apoA-I in plasma HDL, which have the ability of binding scavenger receptors, were directly observed and quantitatively measured by AFM. The three detailed structures probably represent the different extents to which the lipid component of HDL was depleted. Data on lipid depletion of HDL may provide clues to understand lipid insertion of HDL. These data provide important information for the understanding of the structure/maturation of plasma HDL. Moreover, they suggest a powerful method for directly visualizing the major apolipoproteins of plasma lipoproteins or the protein component of lipoprotein-like lipid-protein complexes. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. The intrinsic factor-vitamin B12 receptor, cubilin, is a high-affinity apolipoprotein A-I receptor facilitating endocytosis of high-density lipoprotein.

    PubMed

    Kozyraki, R; Fyfe, J; Kristiansen, M; Gerdes, C; Jacobsen, C; Cui, S; Christensen, E I; Aminoff, M; de la Chapelle, A; Krahe, R; Verroust, P J; Moestrup, S K

    1999-06-01

    Cubilin is the intestinal receptor for the endocytosis of intrinsic factor-vitamin B12. However, several lines of evidence, including a high expression in kidney and yolk sac, indicate it may have additional functions. We isolated apolipoprotein A-I (apoA-I), the main protein of high-density lipoprotein (HDL), using cubilin affinity chromatography. Surface plasmon resonance analysis demonstrated a high-affinity binding of apoA-I and HDL to cubilin, and cubilin-expressing yolk sac cells showed efficient 125I-HDL endocytosis that could be inhibited by IgG antibodies against apoA-I and cubilin. The physiological relevance of the cubilin-apoA-I interaction was further emphasized by urinary apoA-I loss in some known cases of functional cubilin deficiency. Therefore, cubilin is a receptor in epithelial apoA-I/HDL metabolism.

  14. [Separation and purification of human apolipoproteins A-I and C-III by chromatofocusing].

    PubMed

    Cheng, B

    1993-08-01

    Human very low density lipoprotein (VLDL) and high density lipoprotein (HDL) were isolated and purified by a process of combined dextran sulfate precipitation and density gradient ultracentrifugation. Chromatofocusing, which separates protein based on differences in isoelectric point, was used to separate apolipoprotein A-I (apoA-I) and apolipoprotein C-III from human HDL and VLDL, respectively. Discontinuous SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and analytical isoelectric focusing (IEF) were used to study the purity of different fractions. Both purified apoA-I and apoC-III showed single bands on SDS-PAGE at molecular weights of 28183 and 9400 Daltons, respectively. As determined by IEF in the presence of 8 mol/L urea, apoA-I had eight isoforms with pI of 5.66-5.87. The pI's of the three isoproteins of apoC-III (C-III0, C-III1 and C-III2) were 5.06, 4.88 and 4.72, respectively. Chromatofocusing, a new simple technique combining the high resolving power of IEF with the high capacity of ion-exchange column chromatography, is extremely valuable for large-scale purification of the major apolipoproteins of VLDL and HDL.

  15. Plasma activated coating immobilizes apolipoprotein A-I to stainless steel surfaces in its bioactive form and enhances biocompatibility.

    PubMed

    Vanags, Laura Z; Tan, Joanne T M; Santos, Miguel; Michael, Praveesuda S; Ali, Ziad; Bilek, Marcela M M; Wise, Steven G; Bursill, Christina A

    2017-06-29

    We utilized a plasma activated coating (PAC) to covalently bind the active component of high density lipoproteins (HDL), apolipoprotein (apo) A-I, to stainless steel (SS) surfaces. ApoA-I suppresses restenosis and thrombosis and may therefore improve SS stent biocompatibility. PAC-coated SS significantly increased the covalent attachment of apoA-I, compared to SS alone. In static and dynamic flow thrombosis assays, PAC+apoA-I inhibited thrombosis and reduced platelet activation marker p-selectin. PAC+apoA-I reduced smooth muscle cell attachment and proliferation, and augmented EC attachment to PAC. We then coated PAC onto murine SS stents and found it did not peel or delaminate following crimping/expansion. ApoA-I was immobilized onto PAC-SS stents and was retained as a monolayer when exposed to pulsatile flow in vivo in a murine stent model. In conclusion, ApoA-I immobilized on PAC withstands pulsatile flow in vivo and retains its bioactivity, exhibiting anti-thrombotic and anti-restenotic properties, demonstrating the potential to improve stent biocompatibility. Copyright © 2017 Elsevier Inc. All rights reserved.

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

    PubMed

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

    2016-02-01

    Nanodiscs are composed of scaffold protein or peptide such as apolipoprotein A-I (apoA-I) and phospholipids. Although peptide-based nanodiscs have an advantage to modulate the size of nanodiscs by changing phospholipid/peptide ratios, they are usually less stable than apoA-I-based nanodiscs. In this study, we designed a novel nanodisc scaffold peptide (NSP) that has proline-punctuated bihelical amphipathic structure based on apoA-I mimetic peptides. NSP formed α-helical structure on 1-palmitoyl-2-oleoyl phosphatidylcholine (POPC) nanodiscs prepared by cholate dialysis method. Dynamic light scattering measurements demonstrated that diameters of NSP nanodiscs vary depending upon POPC/NSP ratios. Comparison of thermal unfolding of nanodiscs monitored by circular dichroism measurements demonstrated that NSP forms much more stable nanodiscs with POPC than monohelical peptide, 4F, exhibiting comparable stability to apoA-I-POPC nanodiscs. Intrinsic Trp fluorescence measurements showed that Trp residues of NSP exhibit more hydrophobic environment than that of 4 F on nanodiscs, suggesting the stronger interaction of NSP with phospholipids. Thus, the bihelical structure of NSP appears to increase the stability of nanodiscs because of the enhanced interaction of peptides with phospholipids. In addition, NSP as well as 4F spontaneously solubilized POPC vesicles into nanodiscs without using detergent. These results indicate that bihelical NSP forms nanodiscs with comparable stability to apoA-I and has an ability to control the size of nanodiscs simply by changing phospholipid/peptide ratios. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd.

  17. Influence of C-terminal α-helix hydrophobicity and aromatic amino acid content on apolipoprotein A-I functionality.

    PubMed

    Lyssenko, Nicholas N; Hata, Mami; Dhanasekaran, Padmaja; Nickel, Margaret; Nguyen, David; Chetty, Palaniappan Sevugan; Saito, Hiroyuki; Lund-Katz, Sissel; Phillips, Michael C

    2012-03-01

    The apoA-I molecule adopts a two-domain tertiary structure and the properties of these domains modulate the ability to form HDL particles. Thus, human apoA-I differs from mouse apoA-I in that it can form smaller HDL particles; the C-terminal α-helix is important in this process and human apoA-I is unusual in containing aromatic amino acids in the non-polar face of this amphipathic α-helix. To understand the influence of these aromatic amino acids and the associated high hydrophobicity, apoA-I variants were engineered in which aliphatic amino acids were substituted with or without causing a decrease in overall hydrophobicity. The variants human apoA-I (F225L/F229A/Y236A) and apoA-I (F225L/F229L/A232L/Y236L) were compared to wild-type (WT) apoA-I for their abilities to (1) solubilize phospholipid vesicles and form HDL particles of different sizes, and (2) mediate cellular cholesterol efflux and create nascent HDL particles via ABCA1. The loss of aromatic residues and concomitant decrease in hydrophobicity in apoA-I (F225L/F229A/Y236A) has no effect on protein stability, but reduces by a factor of about three the catalytic efficiencies (V(max)/K(m)) of vesicle solubilization and cholesterol efflux; also, relatively large HDL particles are formed. With apoA-I (F225L/F229L/A232L/Y236L) where the hydrophobicity is restored by the presence of only leucine residues in the helix non-polar face, the catalytic efficiencies of vesicle solubilization and cholesterol efflux are similar to those of WT apoA-I; this variant forms smaller HDL particles. Overall, the results show that the hydrophobicity of the non-polar face of the C-terminal amphipathic α-helix plays a critical role in determining apoA-I functionality but aromatic amino acids are not required. This article is part of a Special Issue entitled Advances in High Density Lipoprotein Formation and Metabolism: A Tribute to John F. Oram (1945-2010). Copyright © 2011 Elsevier B.V. All rights reserved.

  18. Apolipoprotein A-II-mediated Conformational Changes of Apolipoprotein A-I in Discoidal High Density Lipoproteins*

    PubMed Central

    Gauthamadasa, Kekulawalage; Vaitinadin, Nataraja Sarma; Dressman, James L.; Macha, Stephen; Homan, Reyn; Greis, Kenneth D.; Silva, R. A. Gangani D.

    2012-01-01

    It is well accepted that HDL has the ability to reduce risks for several chronic diseases. To gain insights into the functional properties of HDL, it is critical to understand the HDL structure in detail. To understand interactions between the two major apolipoproteins (apos), apoA-I and apoA-II in HDL, we generated highly defined benchmark discoidal HDL particles. These particles were reconstituted using a physiologically relevant phospholipid, 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) incorporating two molecules of apoA-I and one homodimer of apoA-II per particle. We utilized two independent mass spectrometry techniques to study these particles. The techniques are both sensitive to protein conformation and interactions and are namely: 1) hydrogen deuterium exchange combined with mass spectrometry and 2) partial acetylation of lysine residues combined with MS. Comparison of mixed particles with apoA-I only particles of similar diameter revealed that the changes in apoA-I conformation in the presence of apoA-II are confined to apoA-I helices 3–4 and 7–9. We discuss these findings with respect to the relative reactivity of these two particle types toward a major plasma enzyme, lecithin:cholesterol acyltransferase responsible for the HDL maturation process. PMID:22235130

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

    USDA-ARS?s Scientific Manuscript database

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

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

    PubMed

    Jayaraman, Shobini; Cavigiolio, Giorgio; Gursky, Olga

    2012-03-15

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

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

    PubMed

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

    2016-02-01

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

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

    PubMed Central

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

    2016-01-01

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

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

    USDA-ARS?s Scientific Manuscript database

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

  4. Elevated homocysteine reduces apolipoprotein A-I expression in hyperhomocysteinemic mice and in males with coronary artery disease.

    PubMed

    Mikael, Leonie G; Genest, Jacques; Rozen, Rima

    2006-03-03

    Hyperhomocysteinemia, a risk factor for cardiovascular disease, is caused by nutritional or genetic disturbances in homocysteine metabolism. A polymorphism in methylenetetrahydrofolate reductase (MTHFR) is the most common genetic cause of mild hyperhomocysteinemia. To examine mechanisms by which an elevation in plasma homocysteine leads to vascular disease, we first performed microarray analyses in livers of Mthfr-deficient mice and identified differentially expressed genes that are involved in lipid and cholesterol metabolism. Microarrays and RT-PCR showed decreased mRNA for apolipoprotein A (ApoA)-IV and for ApoA-I and increased mRNA for cholesterol 7alpha hydroxylase (Cyp7A1) in Mthfr(+/-) mice compared with Mthfr(+/+) mice. Western blotting revealed that ApoA-I protein levels in liver and plasma of Mthfr(+/-) mice were 52% and 62% of levels in the respective tissues of Mthfr(+/+) mice. We also performed Western analysis for plasma ApoA-I protein levels in 60 males with coronary artery disease and identified a significant (P<0.01) negative correlation (-0.33) between ApoA-I and plasma homocysteine levels. This cohort also displayed a negative correlation (-0.24, P=0.06) between high-density lipoprotein cholesterol and plasma homocysteine. Treatment of HepG2 cells with supraphysiological levels of 5 mmol/L homocysteine reduced peroxisome proliferator-activated receptor (PPAR) alpha and ApoA-I protein levels and decreased ApoA-I promoter activity. Transfection with a PPARalpha construct upregulated ApoA-I and MTHFR. Our results suggest that hyperhomocysteinemia may increase risk of atherosclerosis by decreasing expression of ApoA-I and increasing expression of CYP7A1.

  5. Inducing apolipoprotein A-I synthesis to reduce cardiovascular risk: from ASSERT to SUSTAIN and beyond.

    PubMed

    Di Bartolo, Belinda A; Scherer, Daniel J; Nicholls, Stephen J

    2016-12-01

    Increasing attention has focused on efforts to promote the biological activities of high-density lipoproteins (HDL) in order to reduce cardiovascular risk. Targeting apolipoprotein A-I (apoA-I), the major protein carried on HDL particles, represents an attractive approach to promoting HDL by virtue of its ability to increase endogenous synthesis of functional HDL particles. A number of pharmacological strategies that target apoA-I, including upregulation of its production with the bromodomain and extraterminal (BET) protein inhibitor RVX-208, development of short peptide sequences that mimic its action, and administration as a component of reconstituted HDL particles, have undergone clinical development. The impact of these approaches on cardiovascular biomarkers will be reviewed.

  6. Heparin promotes fibril formation by the N-terminal fragment of amyloidogenic apolipoprotein A-I.

    PubMed

    Mikawa, Shiho; Mizuguchi, Chiharu; Nishitsuji, Kazuchika; Baba, Teruhiko; Shigenaga, Akira; Shimanouchi, Toshinori; Sakashita, Naomi; Otaka, Akira; Akaji, Kenichi; Saito, Hiroyuki

    2016-10-01

    Glycosaminoglycans are known to be associated with extracellular amyloid deposits of various amyloidogenic proteins. In this study, we found that the glycosaminoglycan heparin greatly accelerates the elongation step in fibril formation by the N-terminal 1-83 fragment of human apolipoprotein A-I (apoA-I), especially in the amyloidogenic W50R variant. Using fragment peptides, we demonstrate that heparin significantly promotes β-transition and fibril formation of the highly amyloidogenic region spanning residues 44-65 and colocalizes with fibrils formed by the W50R variant. These results suggest the possible role of glycosaminoglycans in fibril formation by amyloidogenic apoA-I variants. © 2016 Federation of European Biochemical Societies.

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

    PubMed

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

    2015-03-01

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

  8. Site-specific Nitration of Apolipoprotein A-I at Tyrosine 166 Is Both Abundant within Human Atherosclerotic Plaque and Dysfunctional*

    PubMed Central

    DiDonato, Joseph A.; Aulak, Kulwant; Huang, Ying; Wagner, Matthew; Gerstenecker, Gary; Topbas, Celalettin; Gogonea, Valentin; DiDonato, Anthony J.; Tang, W. H. Wilson; Mehl, Ryan A.; Fox, Paul L.; Plow, Edward F.; Smith, Jonathan D.; Fisher, Edward A.; Hazen, Stanley L.

    2014-01-01

    We reported previously that apolipoprotein A-I (apoA-I) is oxidatively modified in the artery wall at tyrosine 166 (Tyr166), serving as a preferred site for post-translational modification through nitration. Recent studies, however, question the extent and functional importance of apoA-I Tyr166 nitration based upon studies of HDL-like particles recovered from atherosclerotic lesions. We developed a monoclonal antibody (mAb 4G11.2) that recognizes, in both free and HDL-bound forms, apoA-I harboring a 3-nitrotyrosine at position 166 apoA-I (NO2-Tyr166-apoA-I) to investigate the presence, distribution, and function of this modified apoA-I form in atherosclerotic and normal artery wall. We also developed recombinant apoA-I with site-specific 3-nitrotyrosine incorporation only at position 166 using an evolved orthogonal nitro-Tyr-aminoacyl-tRNA synthetase/tRNACUA pair for functional studies. Studies with mAb 4G11.2 showed that NO2-Tyr166-apoA-I was easily detected in atherosclerotic human coronary arteries and accounted for ∼8% of total apoA-I within the artery wall but was nearly undetectable (>100-fold less) in normal coronary arteries. Buoyant density ultracentrifugation analyses showed that NO2-Tyr166-apoA-I existed as a lipid-poor lipoprotein with <3% recovered within the HDL-like fraction (d = 1.063–1.21). NO2-Tyr166-apoA-I in plasma showed a similar distribution. Recovery of NO2-Tyr166-apoA-I using immobilized mAb 4G11.2 showed an apoA-I form with 88.1 ± 8.5% reduction in lecithin-cholesterol acyltransferase activity, a finding corroborated using a recombinant apoA-I specifically designed to include the unnatural amino acid exclusively at position 166. Thus, site-specific nitration of apoA-I at Tyr166 is an abundant modification within the artery wall that results in selective functional impairments. Plasma levels of this modified apoA-I form may provide insights into a pathophysiological process within the diseased artery wall. PMID:24558038

  9. Human macrophage cathepsin B-mediated C-terminal cleavage of apolipoprotein A-I at Ser228 severely impairs antiatherogenic capacity.

    PubMed

    Dinnes, Donna Lee M; White, Melanie Y; Kockx, Maaike; Traini, Mathew; Hsieh, Victar; Kim, Mi-Jurng; Hou, Liming; Jessup, Wendy; Rye, Kerry-Anne; Thaysen-Andersen, Morten; Cordwell, Stuart J; Kritharides, Leonard

    2016-12-01

    Apolipoprotein A-I (apoA-I) is the major component of HDL and central to the ability of HDL to stimulate ATP-binding cassette transporter A1 (ABCA1)-dependent, antiatherogenic export of cholesterol from macrophage foam cells, a key player in the pathology of atherosclerosis. Cell-mediated modifications of apoA-I, such as chlorination, nitration, oxidation, and proteolysis, can impair its antiatherogenic function, although it is unknown whether macrophages themselves contribute to such modifications. To investigate this, human monocyte-derived macrophages (HMDMs) were incubated with human apoA-I under conditions used to induce cholesterol export. Two-dimensional gel electrophoresis and Western blot analysis identified that apoA-I is cleaved (∼20-80%) by HMDMs in a time-dependent manner, generating apoA-I of lower MW and isoelectric point. Mass spectrometry analysis identified a novel C-terminal cleavage site of apoA-I between Ser(228)-Phe(229) Recombinant apoA-I truncated at Ser(228) demonstrated profound loss of capacity to solubilize lipid and to promote ABCA1-dependent cholesterol efflux. Protease inhibitors, small interfering RNA knockdown in HMDMs, mass spectrometry analysis, and cathepsin B activity assays identified secreted cathepsin B as responsible for apoA-I cleavage at Ser(228) Importantly, C-terminal cleavage of apoA-I was also detected in human carotid plaque. Cleavage at Ser(228) is a novel, functionally important post-translational modification of apoA-I mediated by HMDMs that limits the antiatherogenic properties of apoA-I.-Dinnes, D. L. M., White, M. Y., Kockx, M., Traini, M., Hsieh, V., Kim, M.-J., Hou, L., Jessup, W., Rye, K.-A., Thaysen-Andersen, M., Cordwell, S. J., Kritharides, L. Human macrophage cathepsin B-mediated C-terminal cleavage of apolipoprotein A-I at Ser(228) severely impairs antiatherogenic capacity. © FASEB.

  10. HDL-apolipoprotein A-I exchange is independently associated with cholesterol efflux capacity.

    PubMed

    Borja, Mark S; Ng, Kit F; Irwin, Angela; Hong, Jaekyoung; Wu, Xing; Isquith, Daniel; Zhao, Xue-Qiao; Prazen, Bryan; Gildengorin, Virginia; Oda, Michael N; Vaisar, Tomáš

    2015-10-01

    HDL is the primary mediator of cholesterol mobilization from the periphery to the liver via reverse cholesterol transport (RCT). A critical first step in this process is the uptake of cholesterol from lipid-loaded macrophages by HDL, a function of HDL inversely associated with prevalent and incident cardiovascular disease. We hypothesized that the dynamic ability of HDL to undergo remodeling and exchange of apoA-I is an important and potentially rate-limiting aspect of RCT. In this study, we investigated the relationship between HDL-apoA-I exchange (HAE) and serum HDL cholesterol (HDL-C) efflux capacity. We compared HAE to the total and ABCA1-specific cholesterol efflux capacity of 77 subjects. We found that HAE was highly correlated with both total (r = 0.69, P < 0.0001) and ABCA1-specific (r = 0.47, P < 0.0001) efflux, and this relationship remained significant after adjustment for HDL-C or apoA-I. Multivariate models of sterol efflux capacity indicated that HAE accounted for approximately 25% of the model variance for both total and ABCA1-specific efflux. We conclude that the ability of HDL to exchange apoA-I and remodel, as measured by HAE, is a significant contributor to serum HDL efflux capacity, independent of HDL-C and apoA-I, indicating that HDL dynamics are an important factor in cholesterol efflux capacity and likely RCT. Copyright © 2015 by the American Society for Biochemistry and Molecular Biology, Inc.

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

    PubMed

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

    2016-06-01

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

  12. Structures of apolipoprotein A-I in high density lipoprotein generated by electron microscopy and biased simulations.

    PubMed

    Zhu, Lin; Petrlova, Jitka; Gysbers, Peter; Hebert, Hans; Wallin, Stefan; Jegerschöld, Caroline; Lagerstedt, Jens O

    2017-07-25

    Apolipoprotein A-I (apoA-I) in high-density lipoprotein (HDL) is a key protein for the transport of cholesterol from the vascular wall to the liver. The formation and structure of nascent HDL, composed of apoA-I and phospholipids, is critical to this process. The HDL was assembled in vitro from apoA-I, cholesterol and 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) at a 1:4:50 molar ratio. The structure of HDL was investigated in vitreous samples, frozen at cryogenic temperatures, as well as in negatively stained samples by transmission electron microscopy. Low resolution electron density maps were next used as restraints in biased Monte Carlo simulations of apolipoprotein A-I dimers, with an initial structure derived from atomic resolution X-ray structures. Two final apoA-I structure models for the full-length structure of apoA-I dimer in the lipid bound conformation were generated, showing a nearly circular, flat particle with an uneven particle thickness. The generated structures provide evidence for the discoidal, antiparallel arrangement of apoA-I in nascent HDL, and propose two preferred conformations of the flexible N-termini. The novel full-length structures of apoA-I dimers deepens the understanding to the structure-function relationship of nascent HDL with significance for the prevention of lipoprotein-related disease. The biased simulation method used in this study provides a powerful and convenient modelling tool with applicability for structural studies and modelling of other proteins and protein complexes. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Apolipoprotein A-I and Paraoxonase-1 Are Potential Blood Biomarkers for Ischemic Stroke Diagnosis.

    PubMed

    Walsh, Kyle B; Hart, Kimberly; Roll, Susan; Sperling, Matthew; Unruh, Dusten; Davidson, W Sean; Lindsell, Christopher J; Adeoye, Opeolu

    2016-06-01

    Blood biomarkers for ischemic and hemorrhagic stroke diagnosis remain elusive. Recent investigations suggested that apolipoprotein (Apo), matrix metalloproteinase (MMP), and paraoxonase-1 may be associated with stroke. We hypothesized that Apo A-I, Apo C-I, Apo C-III, MMP-3, MMP-9, and paraoxonase-1 are differentially expressed in ischemic stroke, hemorrhagic stroke, and controls. In a single-center prospective observational study, consecutive stroke cases were enrolled if blood samples were obtainable within 12 hours of symptom onset. Age- (±5 years), race-, and sex-matched controls were recruited. Multiplex assays were used to measure protein levels. The Wilcoxon signed-rank test and the Mann-Whitney U-test were used to compare biomarker values between ischemic stroke patients and controls, hemorrhagic stroke patients and controls, and ischemic and hemorrhagic stroke patients. The 95% confidence intervals (CIs) for the difference of 2 medians were calculated. Fourteen ischemic stroke case-control pairs and 23 intracerebral hemorrhage (ICH) case-control pairs were enrolled. Median Apo A-I levels were lower in ischemic stroke cases versus controls (140 mg/dL versus 175 mg/dL, difference of 35 mg/dL, 95% CI -54 to -16) and in ischemic stroke versus ICH cases (140 mg/dL versus 180 mg/dL, difference of 40 mg/dL, 95% CI -57 to -23). Median paraoxonase-1 was lower in ischemic stroke cases than in both ICH cases and matched controls. Median Apo C-I was slightly lower in ischemic stroke cases than in ICH cases. There were no differences between groups for MMP-3, MMP-9, and Apo C-III. Apo A-I and paraoxonase-1 levels may be clinically useful for ischemic stroke diagnosis and for differentiating between ischemic and hemorrhagic strokes. Copyright © 2016 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  14. A facile method for isolation of recombinant human apolipoprotein A-I from E. coli.

    PubMed

    Ikon, Nikita; Shearer, Jennifer; Liu, Jianfang; Tran, Jesse J; Feng, ShiBo; Kamei, Ayako; Beckstead, Jennifer A; Kiss, Robert S; Weers, Paul M; Ren, Gang; Ryan, Robert O

    2017-06-01

    Apolipoprotein (apo) A-I is the major protein component of high-density lipoprotein (HDL) and plays key roles in the Reverse Cholesterol Transport pathway. In the past decade, reconstituted HDL (rHDL) has been employed as a therapeutic agent for treatment of atherosclerosis. The ability of rHDL to promote cholesterol efflux from peripheral cells has been documented to reduce the size of atherosclerotic plaque lesions. However, development of apoA-I rHDL-based therapeutics for human use requires a cost effective process to generate an apoA-I product that meets "Good Manufacturing Practice" standards. Methods available for production and isolation of unmodified recombinant human apoA-I at scale are cumbersome, laborious and complex. To overcome this obstacle, a streamlined two-step procedure has been devised for isolation of recombinant untagged human apoA-I from E. coli that takes advantage of its ability to re-fold to a native conformation following denaturation. Heat treatment of a sonicated E. coli supernatant fraction induced precipitation of a large proportion of host cell proteins (HCP), yielding apoA-I as the major soluble protein. Reversed-phase HPLC of this material permitted recovery of apoA-I largely free of HCP and endotoxin. Purified apoA-I possessed α-helix secondary structure, formed rHDL upon incubation with phospholipid and efficiently promoted cholesterol efflux from cholesterol loaded J774 macrophages. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. A facile method for isolation of recombinant human apolipoprotein A-I from E. coli

    DOE PAGES

    Ikon, Nikita; Shearer, Jennifer; Liu, Jianfang; ...

    2017-03-20

    Apolipoprotein (apo) A-I is the major protein component of high-density lipoprotein (HDL) and plays key roles in the Reverse Cholesterol Transport pathway. In the past decade, reconstituted HDL (rHDL) has been employed as a therapeutic agent for treatment of atherosclerosis. The ability of rHDL to promote cholesterol efflux from peripheral cells has been documented to reduce the size of atherosclerotic plaque lesions. However, development of apoA-I rHDL-based therapeutics for human use requires a cost effective process to generate an apoA-I product that meets “Good Manufacturing Practice” standards. Methods available for production and isolation of unmodified recombinant human apoA-I at scalemore » are cumbersome, laborious and complex. To overcome this obstacle, a streamlined two-step procedure has been devised for isolation of recombinant untagged human apoA-I from E. coli that takes advantage of its ability to re-fold to a native conformation following denaturation. Heat treatment of a sonicated E. coli supernatant fraction induced precipitation of a large proportion of host cell proteins (HCP), yielding apoA-I as the major soluble protein. Reversed-phase HPLC of this material permitted recovery of apoA-I largely free of HCP and endotoxin. In conclusion, purified apoA-I possessed α-helix secondary structure, formed rHDL upon incubation with phospholipid and efficiently promoted cholesterol efflux from cholesterol loaded J774 macrophages.« less

  16. Therapeutic ultrasound: Increased HDL-Cholesterol following infusions of acoustic microspheres and apolipoprotein A-I plasmids.

    PubMed

    Castle, Jason W; Kent, Kevin P; Fan, Ying; Wallace, Kirk D; Davis, Cynthia E L; Roberts, Jeannette C; Marino, Michael E; Thomenius, Kai E; Lim, Hae W; Coles, Eric; Davidson, Michael H; Feinstein, Steven B; DeMaria, Anthony

    2015-07-01

    Low levels of HDL-C are an independent cardiovascular risk factor associated with increased premature cardiovascular death. However, HDL-C therapies historically have been limited by issues relating to immunogenicity, hepatotoxicity and scalability, and have been ineffective in clinical trials. We examined the feasibility of using injectable acoustic microspheres to locally deliver human ApoA-I DNA plasmids in a pre-clinical model and quantify increased production of HDL-C in vivo. Our novel site-specific gene delivery system was examined in naïve rat model and comprised the following steps: (1) intravenous co-administration of a solution containing acoustically active microspheres (Optison™, GE Healthcare, Princeton, New Jersey) and human ApoA-I plasmids; (2) ultrasound verification of the presence of the microspheres within the liver vasculature; (3) External application of locally-directed acoustic energy, (4) induction of microsphere disruption and in situ sonoporation; (4) ApoA-I plasmid hepatic uptake; (5) transcription and expression of human ApoA-I protein; and (6) elevation of serum HDL-C. Co-administration of ApoA-I plasmids and acoustic microspheres, activated by external ultrasound energy, resulted in transcription and production of human ApoA-I protein and elevated serum HDL-C in rats (up to 61%; p-value < 0.05). HDL-C was increased in rats following ultrasound directed delivery of human ApoA-I plasmids by microsphere sonoporation. The present method provides a novel approach to promote ApoA-I synthesis and nascent HDL-C elevation, potentially permitting the use of a minimally-invasive ultrasound-based, gene delivery system for treating individuals with low HDL-C. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  17. Molecular characterization and developmental expression patterns of apolipoprotein A-I in Senegalese sole (Solea senegalensis Kaup).

    PubMed

    Román-Padilla, J; Rodríguez-Rúa, A; Manchado, M; Hachero-Cruzado, I

    2016-05-01

    The apolipoprotein A-I (ApoA-I) is an essential component of the high density lipoproteins (HDL). In this study, the cDNA and genomic sequences of this apolipoprotein were characterized for first time in Solea senegalensis. The predicted polypeptide revealed conserved structural features including ten repeats in the lipid-binding domain and some residues involved in cholesterol interaction and binding. The gene structure analysis identified four exons and three introns. Moreover, the synteny analysis revealed that apoA-I did not localize with other apolipoproteins indicating a divergent evolution with respect to the apoA-IV and apoE cluster. The phylogenetic analyses identified two distinct apoA-I paralogs in Ostariophysi (referred to as Ia and Ib) and only one (Ib) in Acanthopterygii. Whole-mount in situ hybridization located the apoA-I signal mainly in the yolk syncytial layer in lecitotrophic larval stages. Later at mouth opening, the mRNA signals were detected mainly in liver and intestine compatible with its role in the HDL formation. Moreover, a clear signal was detected in some regions of the brain, retina and neural cord suggesting a role in local regulation of cholesterol homeostasis. After metamorphosis, apoA-I was also detected in other tissues such as gills, head kidney and spleen suggesting a putative role in immunity. Expression analyses in larvae fed two diets with different triacylglycerol levels indicated that apoA-I mRNA levels were more associated to larval size and development than dietary lipid levels. Finally, qPCR analyses of immature and mature transcripts revealed distinct expression profiles suggesting a posttranscriptional regulatory mechanism. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Interaction of human apolipoprotein A-I with model membranes exhibiting lipid domains.

    PubMed

    Arnulphi, Cristina; Sánchez, Susana A; Tricerri, M Alejandra; Gratton, Enrico; Jonas, Ana

    2005-07-01

    Several mechanisms for cell cholesterol efflux have been proposed, including membrane microsolubilization, suggesting that the existence of specific domains could enhance the transfer of lipids to apolipoproteins. In this work isothermal titration calorimetry, circular dichroism spectroscopy, and two-photon microscopy are used to study the interaction of lipid-free apolipoprotein A-I (apoA-I) with small unilamellar vesicles (SUVs) of 1-palmitoyl, 2-oleoyl phosphatidylcholine (POPC) and sphingomyelin (SM), with and without cholesterol. Below 30 degrees C the calorimetric results show that apoA-I interaction with POPC/SM SUVs produces an exothermic reaction, characterized as nonclassical hydrophobic binding. The heat capacity change (DeltaCp degrees ) is small and positive, whereas it was larger and negative for pure POPC bilayers, in the absence of SM. Inclusion of cholesterol in the membranes induces changes in the observed thermodynamic pattern of binding and counteracts the formation of alpha-helices in the protein. Above 30 degrees C the reactions are endothermic. Giant unilamellar vesicles (GUVs) of identical composition to the SUVs, and two-photon fluorescence microscopy techniques, were utilized to further characterize the interaction. Fluorescence imaging of the GUVs indicates coexistence of lipid domains under 30 degrees C. Binding experiments and Laurdan generalized-polarization measurements suggest that there is no preferential binding of the labeled apoA-I to any particular domain. Changes in the content of alpha-helix, binding, and fluidity data are discussed in the framework of the thermodynamic parameters.

  19. Apolipoprotein A-I configuration and cell cholesterol efflux activity of discoidal lipoproteins depend on the reconstitution process.

    PubMed

    Cuellar, Luz Ángela; Prieto, Eduardo Daniel; Cabaleiro, Laura Virginia; Garda, Horacio Alberto

    2014-01-01

    Discoidal high-density lipoproteins (D-HDL) are critical intermediates in reverse cholesterol transport. Most of the present knowledge of D-HDL is based on studies with reconstituted lipoprotein complexes of apolipoprotein A-I (apoA-I) obtained by cholate dialysis (CD). D-HDL can also be generated by the direct microsolubilization (DM) of phospholipid vesicles at the gel/fluid phase transition temperature, a process mechanistically similar to the "in vivo" apoAI lipidation via ABCA1. We compared the apoA-I configuration in D-HDL reconstituted with dimyristoylphosphatidylcholine by both procedures using fluorescence resonance energy transfer measurements with apoA-I tryptophan mutants and fluorescently labeled cysteine mutants. Results indicate that apoA-I configuration in D-HDL depends on the reconstitution process and are consistent with a "double belt" molecular arrangement with different helix registry. As reported by others, a configuration with juxtaposition of helices 5 of each apoAI monomer (5/5 registry) predominates in D-HDL obtained by CD. However, a configuration with helix 5 of one monomer juxtaposed with helix 2 of the other (5/2 registry) would predominate in D-HDL generated by DM. Moreover, we also show that the kinetics of cholesterol efflux from macrophage cultures depends on the reconstitution process, suggesting that apoAI configuration is important for this HDL function. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Polyadenylation site prediction using PolyA-iEP method.

    PubMed

    Kavakiotis, Ioannis; Tzanis, George; Vlahavas, Ioannis

    2014-01-01

    This chapter presents a method called PolyA-iEP that has been developed for the prediction of polyadenylation sites. More precisely, PolyA-iEP is a method that recognizes mRNA 3'ends which contain polyadenylation sites. It is a modular system which consists of two main components. The first exploits the advantages of emerging patterns and the second is a distance-based scoring method. The outputs of the two components are finally combined by a classifier. The final results reach very high scores of sensitivity and specificity.

  1. 13-hydroxy linoleic acid increases expression of the cholesterol transporters ABCA1, ABCG1 and SR-BI and stimulates apoA-I-dependent cholesterol efflux in RAW264.7 macrophages

    PubMed Central

    2011-01-01

    Background Synthetic activators of peroxisome proliferator-activated receptors (PPARs) stimulate cholesterol removal from macrophages through PPAR-dependent up-regulation of liver × receptor α (LXRα) and subsequent induction of cholesterol exporters such as ATP-binding cassette transporter A1 (ABCA1) and scavenger receptor class B type 1 (SR-BI). The present study aimed to test the hypothesis that the hydroxylated derivative of linoleic acid (LA), 13-HODE, which is a natural PPAR agonist, has similar effects in RAW264.7 macrophages. Methods RAW264.7 macrophages were treated without (control) or with LA or 13-HODE in the presence and absence of PPARα or PPARγ antagonists and determined protein levels of LXRα, ABCA1, ABCG1, SR-BI, PPARα and PPARγ and apolipoprotein A-I mediated lipid efflux. Results Treatment of RAW264.7 cells with 13-HODE increased PPAR-transactivation activity and protein concentrations of LXRα, ABCA1, ABCG1 and SR-BI when compared to control treatment (P < 0.05). In addition, 13-HODE enhanced cholesterol concentration in the medium but decreased cellular cholesterol concentration during incubation of cells with the extracellular lipid acceptor apolipoprotein A-I (P < 0.05). Pre-treatment of cells with a selective PPARα or PPARγ antagonist completely abolished the effects of 13-HODE on cholesterol efflux and protein levels of genes investigated. In contrast to 13-HODE, LA had no effect on either of these parameters compared to control cells. Conclusion 13-HODE induces cholesterol efflux from macrophages via the PPAR-LXRα-ABCA1/SR-BI-pathway. PMID:22129452

  2. Apolipoprotein A-I mimetic peptide reverses impaired arterial healing after injury by reducing oxidative stress.

    PubMed

    Rosenbaum, Michael A; Chaudhuri, Pinaki; Abelson, Benjamin; Cross, Brandy N; Graham, Linda M

    2015-08-01

    Endothelial cell (EC) migration is essential for healing of arterial injuries caused by angioplasty, but a high cholesterol diet inhibits endothelial repair. In vivo studies suggest that apolipoprotein A-I (apoA-I), the major protein constituent of HDL, is essential for normal healing of arterial injuries. ApoA-I mimetics, including 4F, have been designed to mimic the amphipathic portion of the apoA-I molecule. This study was undertaken to determine if 4F improves endothelial migration and healing. A razor scrape assay was used to analyze the effect of 4F on EC migration in vitro. Endothelial healing in vivo was assessed following electrical injury of carotid arteries in mice. Markers of oxidative stress were also examined. Lipid oxidation products inhibited EC migration in vitro, but preincubation with L-4F preserved EC migration. Endothelial healing of carotid arterial injuries in mice on a high cholesterol diet was delayed compared with mice on a chow diet with 27.8% vs. 48.2% healing, respectively, at 5 days. Administration of D-4F improved endothelial healing in mice on a high cholesterol diet to 43.4%. D-4F administration had no effect on lipid levels but decreased markers of oxidation. In vivo, there was a significant inverse correlation between endothelial healing and plasma markers of oxidative stress. These studies suggested that an apoA-I mimetic can improve endothelial healing of arterial injuries by decreasing oxidative stress. Published by Elsevier Ireland Ltd.

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

    PubMed Central

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

    2016-01-01

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

  4. Inflammatory markers modify the risk of recurrent coronary events associated with apolipoprotein A-I in postinfarction patients.

    PubMed

    Wang, Meng; Corsetti, James; McNitt, Scott; Rich, David Q; Sparks, Charles E; Moss, Arthur J; Zareba, Wojciech

    Laboratory findings have suggested that systemic and vascular inflammation can impair the antiatherogenic function of high-density lipoproteins (HDLs). However, evidence from population studies is sparse. The objective of the study was to assess if blood inflammatory markers modify the risk of recurrent coronary events associated with apolipoprotein A-I (apoA-I) and HDL cholesterol (HDL-C) among postinfarction patients. ApoA-I, HDL-C, and inflammatory markers (C-reactive protein [CRP], serum amyloid A (SAA), fibrinogen, von Willebrand factor [vWF], and D-dimer) were measured from blood samples of 1028 patients drawn 2 months after an index myocardial infarction (MI). Patients were followed up for the composite coronary endpoint (nonfatal MI, coronary death, or unstable angina) for an average of 26 months. Cox proportional hazard models were used to assess effect modifications for the association of apoA-I and HDL-C with coronary risk by each inflammatory marker. CRP significantly modified the risk of recurrent coronary events associated with apoA-I. Among the entire population, multivariable-adjusted hazard ratios associated with each standard deviation increase in apoA-I for those with low and high CRP levels were 0.89 and 1.35, respectively (P value for interaction = .008). vWF was a significant effect modifier of the apoA-I/coronary risk association only among diabetic patients (hazard ratios were 0.56 and 1.43, for diabetic patients with low and high vWF levels, respectively; P value for interaction = .002). No effect modification was observed for the HDL-C/coronary risk association. Among stable post-MI patients, CRP modified the risk of recurrent coronary events associated with apoA-I. VWF modified this association only among the diabetic subgroup. Copyright © 2017 National Lipid Association. Published by Elsevier Inc. All rights reserved.

  5. Conservation of apolipoprotein A-I's central domain structural elements upon lipid association on different high-density lipoprotein subclasses.

    PubMed

    Oda, Michael N; Budamagunta, Madhu S; Geier, Ethan G; Chandradas, Sajiv H; Shao, Baohai; Heinecke, Jay W; Voss, John C; Cavigiolio, Giorgio

    2013-10-01

    The antiatherogenic properties of apolipoprotein A-I (apoA-I) are derived, in part, from lipidation-state-dependent structural elements that manifest at different stages of apoA-I's progression from lipid-free protein to spherical high-density lipoprotein (HDL). Previously, we reported the structure of apoA-I's N-terminus on reconstituted HDLs (rHDLs) of different sizes. We have now investigated at the single-residue level the conformational adaptations of three regions in the central domain of apoA-I (residues 119-124, 139-144, and 164-170) upon apoA-I lipid binding and HDL formation. An important function associated with these residues of apoA-I is the activation of lecithin:cholesterol acyltransferase (LCAT), the enzyme responsible for catalyzing HDL maturation. Structural examination was performed by site-directed tryptophan fluorescence and spin-label electron paramagnetic resonance spectroscopies for both the lipid-free protein and rHDL particles 7.8, 8.4, and 9.6 nm in diameter. The two methods provide complementary information about residue side chain mobility and molecular accessibility, as well as the polarity of the local environment at the targeted positions. The modulation of these biophysical parameters yielded new insight into the importance of structural elements in the central domain of apoA-I. In particular, we determined that the loosely lipid-associated structure of residues 134-145 is conserved in all rHDL particles. Truncation of this region completely abolished LCAT activation but did not significantly affect rHDL size, reaffirming the important role of this structural element in HDL function.

  6. Molecules that mimic apolipoprotein A-I: potential agents for treating atherosclerosis.

    PubMed

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

    2014-03-27

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

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

    PubMed Central

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

    2013-01-01

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

  8. FOXO1 and LXRα downregulate the apolipoprotein A-I gene expression during hydrogen peroxide-induced oxidative stress in HepG2 cells.

    PubMed

    Shavva, Vladimir S; Bogomolova, Alexandra M; Nikitin, Artemy A; Dizhe, Ella B; Oleinikova, Galina N; Lapikov, Ivan A; Tanyanskiy, Dmitry A; Perevozchikov, Andrej P; Orlov, Sergey V

    2017-01-01

    Reactive oxygen species damage various cell components including DNA, proteins, and lipids, and these impairments could be a reason for severe human diseases including atherosclerosis. Forkhead box O1 (FOXO1), an important metabolic transcription factor, upregulates antioxidant and proapoptotic genes during oxidative stress. Apolipoprotein A-I (ApoA-I) forms high density lipoprotein (HDL) particles that are responsible for cholesterol transfer from peripheral tissues to liver for removal in bile in vertebrates. The main sources for plasma ApoA-I in mammals are liver and jejunum. Hepatic apoA-I transcription depends on a multitude of metabolic transcription factors. We demonstrate that ApoA-I synthesis and secretion are decreased during H2O2-induced oxidative stress in human hepatoma cell line HepG2. Here, we first show that FOXO1 binds to site B of apoA-I hepatic enhancer and downregulates apoA-I gene activity in HepG2 cells. Moreover, FOXO1 and LXRα transcription factors participate in H2O2-triggered downregulation of apoA-I gene together with Src, JNK, p38, and AMPK kinase cascades. Mutations of sites B or C as well as the administration of siRNAs against FOXO1 or LXRα to HepG2 cells abolished the hydrogen peroxide-mediated suppression of apoA-I gene.

  9. Local Vascular Gene Therapy With Apolipoprotein A-I to Promote Regression of Atherosclerosis.

    PubMed

    Wacker, Bradley K; Dronadula, Nagadhara; Zhang, Jingwan; Dichek, David A

    2017-02-01

    Gene therapy, delivered directly to the blood vessel wall, could potentially prevent atherosclerotic lesion growth and promote atherosclerosis regression. Previously, we reported that a helper-dependent adenoviral (HDAd) vector expressing apolipoprotein A-I (apoA-I) in carotid endothelium of fat-fed rabbits reduced early (4 weeks) atherosclerotic lesion growth. Here, we tested whether the same HDAd-delivered to the existing carotid atherosclerotic lesions-could promote regression. Rabbits (n=26) were fed a high-fat diet for 7 months, then treated with bilateral carotid gene transfer. One carotid was infused with an HDAd expressing apoA-I (HDAdApoAI) and the other with a control nonexpressing HDAd (HDAdNull). The side with HDAdApoAI was randomized. Rabbits were then switched to regular chow, lowering their plasma cholesterols by over 70%. ApoA-I mRNA and protein were detected in HDAdApoAI-transduced arteries. After 7 weeks of gene therapy, compared with HDAdNull-treated arteries in the same rabbits, HDAdApoAI-treated arteries had significantly less vascular cell adhesion molecule-1 expression (28%; P=0.04) along with modest but statistically insignificant trends toward decreased intimal lesion volume, lipid and macrophage content, and intercellular adhesion molecule-1 expression (9%-21%; P=0.1-0.4). Post hoc subgroup analysis of rabbits with small-to-moderate-sized lesions (n=20) showed that HDAdApoAI caused large reductions in lesion volume, lipid content, intercellular adhesion molecule-1, and vascular cell adhesion molecule-1 expression (30%-50%; P≤0.04 for all). Macrophage content was reduced by 30% (P=0.06). There was a significant interaction (P=0.02) between lesion size and treatment efficacy. Even when administered on a background of aggressive lowering of plasma cholesterol, local HDAdApoAI vascular gene therapy may promote rapid regression of small-to-moderate-sized atherosclerotic lesions. © 2016 American Heart Association, Inc.

  10. Try P.R.A.I.S.E.

    ERIC Educational Resources Information Center

    Wollam, Scott A.

    1979-01-01

    P.R.A.I.S.E. (Positive Reinforcement and Individualized Systematic Economics) is a multifaceted money system which utilizes positive and negative reinforcement and, at the same time, incorporates peer pressure and reinforcement for behavior modification. The system motivates, relates closely to life situations, and can be applied to all areas of…

  11. Associations of apolipoprotein B/apolipoprotein A-I ratio with pre-diabetes and diabetes risks: a cross-sectional study in Chinese adults.

    PubMed

    Zheng, Shuang; Han, Tingting; Xu, Hua; Zhou, Huan; Ren, Xingxing; Wu, Peihong; Zheng, Jun; Wang, Lihua; Zhang, Ming; Jiang, Yihong; Chen, Yawen; Qiu, Huiying; Liu, Wei; Hu, Yaomin

    2017-01-20

    Apolipoprotein B/apolipoprotein A-I (ApoB/ApoA-I) ratio is a useful predictor of cardiovascular risk. However, the association between the ApoB/ApoA-I ratio and the risk of type 2 diabetes mellitus (T2DM) is still obscure. To investigate the associations between the ApoB/ApoA-I ratio and the risk of T2DM and pre-diabetes in a Chinese population, and to assess the role of gender in these associations. A stratified random sampling design was used in this cross-sectional study which included 264 men and 465 women with normal glucose tolerance (NGT), pre-diabetes or T2DM. Serum ApoB, ApoA-I and other lipid and glycaemic traits were measured. Pearson's partial correlation and multivariable logistic analysis were used to evaluate the associations between ApoB/ApoA-I ratio and the risk of T2DM and pre-diabetes. The ApoB/ApoA-I ratios were significantly increased across the spectrum of NGT, pre-diabetes and T2DM. Women showed higher levels of ApoB/ApoA-I ratio and ApoB than men in the pre-diabetic and T2DM groups, but not in the NGT group. The ApoB/ApoA-I ratio was closely related with triglyceride, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol and other glycaemic traits. Moreover, in women, the risk of diabetes and pre-diabetes in the top and middle tertiles of the ApoB/ApoA-I ratio were 3.65-fold (95% CI 1.69 to 6.10) and 2.19-fold (95% CI 1.38 to 2.84) higher than in the bottom tertile, respectively, after adjusting for potential confounding factors. However, the associations disappeared in men after adjusting for other factors. The ApoB/ApoA-I ratio showed positive associations with the risk of diabetes and pre-diabetes in Chinese women. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  12. Associations of apolipoprotein B/apolipoprotein A-I ratio with pre-diabetes and diabetes risks: a cross-sectional study in Chinese adults

    PubMed Central

    Zheng, Shuang; Han, Tingting; Xu, Hua; Zhou, Huan; Ren, Xingxing; Wu, Peihong; Zheng, Jun; Wang, Lihua; Zhang, Ming; Jiang, Yihong; Chen, Yawen; Qiu, Huiying; Liu, Wei; Hu, Yaomin

    2017-01-01

    Background Apolipoprotein B/apolipoprotein A-I (ApoB/ApoA-I) ratio is a useful predictor of cardiovascular risk. However, the association between the ApoB/ApoA-I ratio and the risk of type 2 diabetes mellitus (T2DM) is still obscure. Aims To investigate the associations between the ApoB/ApoA-I ratio and the risk of T2DM and pre-diabetes in a Chinese population, and to assess the role of gender in these associations. Methods A stratified random sampling design was used in this cross-sectional study which included 264 men and 465 women with normal glucose tolerance (NGT), pre-diabetes or T2DM. Serum ApoB, ApoA-I and other lipid and glycaemic traits were measured. Pearson's partial correlation and multivariable logistic analysis were used to evaluate the associations between ApoB/ApoA-I ratio and the risk of T2DM and pre-diabetes. Results The ApoB/ApoA-I ratios were significantly increased across the spectrum of NGT, pre-diabetes and T2DM. Women showed higher levels of ApoB/ApoA-I ratio and ApoB than men in the pre-diabetic and T2DM groups, but not in the NGT group. The ApoB/ApoA-I ratio was closely related with triglyceride, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol and other glycaemic traits. Moreover, in women, the risk of diabetes and pre-diabetes in the top and middle tertiles of the ApoB/ApoA-I ratio were 3.65-fold (95% CI 1.69 to 6.10) and 2.19-fold (95% CI 1.38 to 2.84) higher than in the bottom tertile, respectively, after adjusting for potential confounding factors. However, the associations disappeared in men after adjusting for other factors. Conclusions The ApoB/ApoA-I ratio showed positive associations with the risk of diabetes and pre-diabetes in Chinese women. PMID:28110289

  13. Elevated high density lipoprotein cholesterol levels correlate with decreased apolipoprotein A-I and A-II fractional catabolic rate in women.

    PubMed Central

    Brinton, E A; Eisenberg, S; Breslow, J L

    1989-01-01

    High levels of HDL-cholesterol (HDL-C) protect against coronary heart disease susceptibility, but the metabolic mechanisms underlying elevated HDL-C levels are poorly understood. We now report the turnover of isologous radioiodinated HDL apolipoproteins, apo A-I and apo A-II, in 15 female subjects on a metabolic diet with HDL-C levels ranging from 51 to 122 mg/dl. The metabolic parameters, fractional catabolic rate (FCR) and absolute synthetic rate (SR), were determined for apo A-I and apo A-II in all subjects. There was an inverse correlation between plasma HDL-C and the FCR of apo A-I and apo A-II (r = -0.75, P less than 0.001, and r = -0.54, P = 0.036, respectively), but no correlation with the SR of either apo A-I or apo A-II (r = 0.09, and r = -0.16, respectively, both P = NS). Apo A-I levels correlated inversely with apo A-I FCR (r = -0.64, P = 0.01) but not with apo A-I SR (r = 0.30, P = NS). In contrast, plasma levels of apo A-II did not correlate with apo A-II FCR (r = -0.38, P = 0.16), but did correlate with apo A-II SR (r = 0.65, P = 0.009). Further analysis showed that apo A-I and apo A-II FCR were inversely correlated with the HDL-C/apo A-I + A-II ratio (r = -0.69 and -0.61, P = 0.005 and 0.015, respectively). These data suggest that: (a) low HDL apolipoprotein FCR is the predominant metabolic mechanism of elevated HDL-C levels; (b) apo A-I FCR is the primary factor in controlling plasma apo A-I levels, but apo A-II SR is the primary factor controlling plasma apo A-II levels; (c) low HDL apolipoprotein FCR is associated with a lipid-rich HDL fraction. These findings elucidate aspects of HDL metabolism which contribute to high HDL-C levels and which may constitute mechanisms for protection against coronary heart disease. PMID:2500457

  14. A novel compound 4010B-30 upregulates apolipoprotein A-I gene expression through activation of PPARγ in HepG2 cells.

    PubMed

    Du, Yu; Wang, Li; Si, Shuyi; Yang, Yuan; Hong, Bin

    2015-04-01

    Apolipoprotein (Apo) A-I is the major lipoprotein content of HDL and upregulating endogenous ApoA-I expression has been proposed as a desirable approach to raise the functional HDL. In this study we investigated the effect of a novel small molecule 4010B-30 on transcriptional regulation of ApoA-I gene in HepG2 cells, and the influence on the level of ApoA-I expression and function. Then the mechanisms by which 4010B-30 regulated ApoA-I expression was further explored. In human hepatic HepG2 cells, 4010B-30 increased the mRNA level and the protein production of ApoA-I both in cell lysates and media. The 4010B-30-induced ApoA-I containing particles increased cholesterol efflux from RAW264.7 macrophages. 4010B-30 also upregulated ABCA1 expression confirmed by transcriptional activity assay and Western blot analysis in both HepG2 and RAW264.7 cells. Promoter luciferase assay was used to identify the 4010B-30-responsive region which is mapped to the proximal -277bp region of the ApoA-I promoter. Further study indicated that the regulation of 4010B-30 on ApoA-I transcription or protein expression in HepG2 cells was abrogated with the suppression of PPARγ by its small interfering RNA or a specific inhibitor, GW9662. These findings suggest that the novel small molecular upregulator 4010B-30 increases ApoA-I gene expression, thereby enhances its function of promoting cholesterol efflux, as well as ABCA1 expression in vitro, and activation of PPARγ is required for 4010B-30 to induce hepatic ApoA-I production. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  15. High-density Lipoproteins and Apolipoprotein A-I: Potential New Players in the Prevention and Treatment of Lung Disease.

    PubMed

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

    2016-01-01

    Apolipoprotein A-I (apoA-I) and high-density lipoproteins (HDL) mediate reverse cholesterol transport out of cells. Furthermore, HDL has additional protective functions, which include anti-oxidative, anti-inflammatory, anti-apoptotic, and vasoprotective effects. In contrast, HDL can become dysfunctional with a reduction in both cholesterol efflux and anti-inflammatory properties in the setting of disease or the acute phase response. These paradigms are increasingly being recognized to be active in the pulmonary system, where apoA-I and HDL have protective effects in normal lung health, as well as in a variety of disease states, including acute lung injury (ALI), asthma, chronic obstructive pulmonary disease, lung cancer, pulmonary arterial hypertension, pulmonary fibrosis, and viral pneumonia. Similar to observations in cardiovascular disease, however, HDL may become dysfunctional and contribute to disease pathogenesis in respiratory disorders. Furthermore, synthetic apoA-I mimetic peptides have been shown to have protective effects in animal models of ALI, asthma, pulmonary hypertension, and influenza pneumonia. These findings provide evidence to support the concept that apoA-I mimetic peptides might be developed into a new treatment that can either prevent or attenuate the manifestations of lung diseases, such as asthma. Thus, the lung is positioned to take a page from the cardiovascular disease playbook and utilize the protective properties of HDL and apoA-I as a novel therapeutic approach.

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

    NASA Astrophysics Data System (ADS)

    Winford, Sidney; Tobin, Moriah; Gross, Eitan

    2012-03-01

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

  17. High-density Lipoproteins and Apolipoprotein A-I: Potential New Players in the Prevention and Treatment of Lung Disease

    PubMed Central

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

    2016-01-01

    Apolipoprotein A-I (apoA-I) and high-density lipoproteins (HDL) mediate reverse cholesterol transport out of cells. Furthermore, HDL has additional protective functions, which include anti-oxidative, anti-inflammatory, anti-apoptotic, and vasoprotective effects. In contrast, HDL can become dysfunctional with a reduction in both cholesterol efflux and anti-inflammatory properties in the setting of disease or the acute phase response. These paradigms are increasingly being recognized to be active in the pulmonary system, where apoA-I and HDL have protective effects in normal lung health, as well as in a variety of disease states, including acute lung injury (ALI), asthma, chronic obstructive pulmonary disease, lung cancer, pulmonary arterial hypertension, pulmonary fibrosis, and viral pneumonia. Similar to observations in cardiovascular disease, however, HDL may become dysfunctional and contribute to disease pathogenesis in respiratory disorders. Furthermore, synthetic apoA-I mimetic peptides have been shown to have protective effects in animal models of ALI, asthma, pulmonary hypertension, and influenza pneumonia. These findings provide evidence to support the concept that apoA-I mimetic peptides might be developed into a new treatment that can either prevent or attenuate the manifestations of lung diseases, such as asthma. Thus, the lung is positioned to take a page from the cardiovascular disease playbook and utilize the protective properties of HDL and apoA-I as a novel therapeutic approach. PMID:27708582

  18. Molecular crowding impacts the structure of apolipoprotein A-I with potential implications on in vivo metabolism and function.

    PubMed

    Petrlova, Jitka; Hilt, Silvia; Budamagunta, Madhu; Domingo-Espín, Joan; Voss, John C; Lagerstedt, Jens O

    2016-10-01

    The effect molecular crowding, defined as the volume exclusion exerted by one soluble inert molecule upon another soluble molecule, has on the structure and self-interaction of lipid-free apoA-I were explored. The influence of molecular crowding on lipid-free apoA-I oligomerization and internal dynamics has been analyzed using electron paramagnetic resonance (EPR) spectroscopy measurements of nitroxide spin label at selected positions throughout the protein sequence and at varying concentrations of the crowding agent Ficoll-70. The targeted positions include sites previously shown to be sensitive for detecting intermolecular interaction via spin-spin coupling. Circular dichroism was used to study secondary structural changes in lipid-free apoA-I imposed by increasing concentrations of the crowding agent. Crosslinking and SDS-PAGE gel analysis was employed to further characterize the role molecular crowding plays in inducing apoA-I oligomerization. It was concluded that the dynamic apoA-I structure and oligomeric state was altered in the presence of the crowding agent. It was also found that the C-terminal was slightly more sensitive to molecular crowding. Finally, the data described the region around residue 217 in the C-terminal domain of apoA-I as the most sensitive reporter of the crowding-induced self-association of apoA-I. The implications of this behavior to in vivo functionality are discussed. © 2016 Wiley Periodicals, Inc. Biopolymers 105: 683-692, 2016. © 2016 Wiley Periodicals, Inc.

  19. Corneal vesicles accumulate collagen VI associated with tissue remodeling in apolipoprotein a-I deficiency: a case report.

    PubMed

    Namba, Hiroyuki; Narumi, Mari; Susa, Shinji; Ohe, Rintaro; Kato, Takeo; Yamakawa, Mitsunori; Yamashita, Hidetoshi

    2017-02-08

    Apo A-I deficiency clinically shows low serum levels of HDL cholesterol and corneal opacity at a young age. Histopathological evaluations of affected corneas are not enough, and the mechanism of corneal opacity is still unclear. A 61-year-old woman suffered from blurred vision with a corneal opacity. She had significantly reduced serum levels of high-density lipoprotein cholesterol and Apo A-I, stenosis of the coronary arteries, and ischemic heart failure. On genetic examination, a homozygous mutation of Apo A-ITsukuba was identified. Histopathological examination of the corneal button after PKP showed numerous vesicles in the corneal stroma, which were more prominent in the deep stroma than in the shallow stroma. Collagen VI was observed in some of those vesicles. We experienced a rare case of corneal opacity due to Apo A-I deficiency. Our histopathological findings indicated that structural changes in corneal collagen fibrils contribute to the formation of stromal vesicles.

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

    ERIC Educational Resources Information Center

    Lungo, Diane; And Others

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

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

    ERIC Educational Resources Information Center

    Lungo, Diane; And Others

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

  2. Effect of urotensin II on apolipoprotein B100 and apolipoprotein A-I expression in HepG2 cell line

    PubMed Central

    Mohammadi, Abbas; Najar, Ahmad Gholamhoseinian; Khoshi, Amirhosein

    2014-01-01

    Background: Increased apolipoprotein B100 (apo B) and decreased apolipoprotein A-I (apo A-I) production are important risk factors in atherosclerosis. Urotensin II (UII), as the most potent vasoconstrictor in human, is related with hypertension and probably atherosclerosis. Because of the relationship between the hypertension and lipoprotein metabolism in atherosclerosis, the aim of this study was to test the effect of urotensin II on apo B and apo A-I expression in hepatic (HepG2) cell line. Materials and Methods: HepG2 cells were treated with 10, 50, 100, and 200 nmol/L of urotensin II (n = 6). Relative apo B and apo A-I messenger RNA (mRNA) levels in conditioned media, normalized to glyceraldehyde-3-phosphate dehydrogenase, were measured with quantitative real-time polymerase chain reaction method. In addition, apo B and apo A-I levels were also estimated and compared with the controls using the western blotting method. Data were analyzed statistically by ANOVA and non-parametric tests. Results: The apo B mRNA levels were not increased significantly following the treatment with UII. However, apo B protein levels were increased significantly after the treatment with urotensin II, especially at 100 and 200 nmol/L. The apo A-I mRNA and protein levels in conditioned media also were not significantly changed. However, there was a significant decrease in apo A-I mRNA and protein levels at 200 nM UII. Conclusions: UII might increase apo B at protein level probably through participating factors in its synthesis and/ or stability/degradation. In addition, UII may have decreasing effect at more than 200 nM concentrations on apo A-I. PMID:24600602

  3. Preparation of soluble apolipoproteins A-I, B, and C-II by a chromatofocusing column method, and evaluation of their concentrations in serum in pulmonary disease.

    PubMed

    Jauhiainen, M; Laitinen, M; Marniemi, J; Liippo, K; Penttilä, I; Hietanen, E

    1983-10-01

    A chromatofocusing column method for isolating ApoB is described. LDL is first isolated by sequential ultracentrifugation and delipidated with n-butanol/diisopropyl ether. Chromatofocusing of ApoLDL yielded a large ApoB peak at pI 5.0-5.3. ApoA-I and ApoC-II were prepared analogously, with HDL and VLDL as the source of apoprotein. Antisera were raised in rabbits, and electroimmunoassay techniques were used for determination. ApoB was water-soluble after chromatofocusing. Intra-assay precision (CV) was 4.7% for ApoA-I, 7.8% for ApoB in the "rocket" electrophoresis. Interassay precision (CV) was 6% for ApoA-I and 8% for ApoB. Apolipoprotein concentrations were measured in subjects who had undergone lung resection and patients with obstructive pulmonary disease. After lung resection, the concentration of ApoA-I in serum was significantly decreased (p less than 0.001) and that of ApoB significantly increased (p less than 0.001) as compared with controls. The ApoA-I/ApoB ratio was significantly lower in the lung-resection group. ApoA-I and ApoB concentrations were unchanged in chronic obstructive pulmonary disease. ApoC-II concentrations in each group were similar to those for control subjects. Of the lipids, values for total cholesterol were above normal after lung resection (p less than 0.002), as were those for triglycerides (p less than 0.02).

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

    PubMed

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

    2016-02-01

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

  5. Apolipoprotein A-I Mimetic Peptides: Discordance Between In Vitro and In Vivo Properties-Brief Report.

    PubMed

    Ditiatkovski, Michael; Palsson, Jonatan; Chin-Dusting, Jaye; Remaley, Alan T; Sviridov, Dmitri

    2017-07-01

    Apolipoprotein A-I (apoA-I) mimetic peptides have antiatherogenic properties of high-density lipoprotein in vitro and have been shown to inhibit atherosclerosis in vivo. It is unclear, however, if each in vitro antiatherogenic property of these peptides translates to a corresponding activity in vivo, and if so, which of these contributes most to reduce atherosclerosis. The effect of 7 apoA-I mimetic peptides, which were developed to selectively reproduce a specific component of the antiatherogenic properties of apoA-I, on the development of atherosclerosis was investigated in apolipoprotein E-deficient mice fed a high-fat diet for 4 or 12 weeks. The peptides include those that selectively upregulate cholesterol efflux, or are anti-inflammatory, or have antioxidation properties. All the peptides studied effectively inhibited the in vivo development of atherosclerosis in this model to the same extent. However, none of the peptides had the same selective effect in vivo as they had exhibited in vitro. None of the tested peptides affected plasma lipoprotein profile; capacity of plasma to support cholesterol efflux was increased modestly and similarly for all peptides. There is a discordance between the selective in vitro and in vivo functional properties of apoA-I mimetic peptides, and the in vivo antiatherosclerotic effect of apoA-I-mimetic peptides is independent of their in vitro functional profile. Comparing the properties of apoA-I mimetic peptides in plasma rather than in the lipid-free state is better for predicting their in vivo effects on atherosclerosis. © 2017 American Heart Association, Inc.

  6. Comparative models for human apolipoprotein A-I bound to lipid in discoidal high-density lipoprotein particles.

    PubMed

    Klon, Anthony E; Segrest, Jere P; Harvey, Stephen C

    2002-09-10

    We have constructed a series of models for apolipoprotein A-I (apo A-I) bound to discoidal high-density lipoprotein (HDL) particles, based upon the molecular belt model [Segrest, J. P., et al. (1999) J. Biol. Chem. 274, 31755-31758] and helical hairpin models [Rogers, D. P., et al. (1998) Biochemistry 37, 11714-11725], and compared these with picket fence models [Phillips, J. C., et al. (1997) Biophys. J. 73, 2337-2346]. Molecular belt models for discoidal HDL particles with differing diameters are presented, illustrating that the belt model can explain the discrete changes in HDL particle size observed experimentally. Hairpin models are discussed for the binding of apo A-I to discoidal HDL particles with diameters identical to those for the molecular belt model. Two models are presented for the binding of three monomers of apo A-I to a 150 A diameter discoidal HDL particle. In one model, two monomers of apo A-I bind to the exterior of the HDL particle in an antiparallel belt, with a third monomer of apo A-I bound to the disk in a hairpin conformation. In the second model, all three monomers of apo A-I are bound to the discoidal HDL particle in a hairpin conformation. Previously published experimental data for each model are reviewed, with FRET favoring either the belt or hairpin models over the picket fence models for HDL particles with diameters of 105 A. Naturally occurring mutations appear to favor the belt model for the 105 A particles, while the 150 A HDL particles favor the presence of at least one hairpin.

  7. Association of carotid intima-media thickness with leptin and apoliprotein b/apoliprotein a-I ratio reveals imminent predictors of subclinical atherosclerosis in psoriasis patients.

    PubMed

    Asha, Kumari; Sharma, Suman B; Singal, Archana; Aggarwal, Amitesh

    2014-01-01

    Psoriasis patients are often susceptible to cardiovascular diseases (CVD), including atherosclerosis. Traditional markers (biochemical and inflammatory) and diagnostic tools could detect occlusive but not subclinical atherosclerosis. Carotid intima-media thickness (CIMT), has recently been recognised as a non invasive diagnostic tool for identification of premature atherosclerosis. Therefore we evaluated 80 psoriasis patients and 80 age sex matched healthy controls for serum leptin levels and apolipoprotein B/apolipoprotein A-I ratio (apoB/apoA-I ratio) in relation with CIMT of carotid artery. Carotid intima-media thickness and carotid plaques were simultaneously measured by carotid sonography. Serum concentration of leptin and apolipoprotein were measured using enzyme-linked immuno sorbent assay (ELISA) and nephelometry respectively. Raised CIMT correlated to age of onset of the disease, serum leptin and apoB/apoA-I ratio in psoriasis patients. Taking into account, values that were above the 75 percentile of the three markers (leptin, apoB/apoA-I ratio and CIMT) the odds ratio was 4.26 (2.06-8.80 CI). Leptin and apoB/apoA-I ratio showed significant cumulative association with CIMT. Results of predictive analysis supports measurement of CIMT along with estimation of serum leptin and apoB/apoA-I ratio for prediction of premature atherosclerosis in psoriasis patients.

  8. In vivo PET imaging with [(18)F]FDG to explain improved glucose uptake in an apolipoprotein A-I treated mouse model of diabetes.

    PubMed

    Cochran, Blake J; Ryder, William J; Parmar, Arvind; Tang, Shudi; Reilhac, Anthonin; Arthur, Andrew; Charil, Arnaud; Hamze, Hasar; Barter, Philip J; Kritharides, Leonard; Meikle, Steven R; Gregoire, Marie-Claude; Rye, Kerry-Anne

    2016-09-01

    Type 2 diabetes is characterised by decreased HDL levels, as well as the level of apolipoprotein A-I (apoA-I), the main apolipoprotein of HDLs. Pharmacological elevation of HDL and apoA-I levels is associated with improved glycaemic control in patients with type 2 diabetes. This is partly due to improved glucose uptake in skeletal muscle. This study used kinetic modelling to investigate the impact of increasing plasma apoA-I levels on the metabolism of glucose in the db/db mouse model. Treatment of db/db mice with apoA-I for 2 h significantly improved both glucose tolerance (AUC 2574 ± 70 mmol/l × min vs 2927 ± 137 mmol/l × min, for apoA-I and PBS, respectively; p < 0.05) and insulin sensitivity (AUC 388.8 ± 23.8 mmol/l × min vs 194.1 ± 19.6 mmol/l × min, for apoA-I and PBS, respectively; p < 0.001). ApoA-I treatment also increased glucose uptake by skeletal muscle in both an insulin-dependent and insulin-independent manner as evidenced by increased uptake of fludeoxyglucose ([(18)F]FDG) from plasma into gastrocnemius muscle in apoA-I treated mice, both in the absence and presence of insulin. Kinetic modelling revealed an enhanced rate of insulin-mediated glucose phosphorylation (k 3) in apoA-I treated mice (3.5 ± 1.1 × 10(-2) min(-1) vs 2.3 ± 0.7 × 10(-2) min(-1), for apoA-I and PBS, respectively; p < 0.05) and an increased influx constant (3.7 ± 0.6 × 10(-3) ml min(-1) g(-1) vs 2.0 ± 0.3 × 10(-3) ml min(-1) g(-1), for apoA-I and PBS, respectively; p < 0.05). Treatment of L6 rat skeletal muscle cells with apoA-I for 2 h indicated that increased hexokinase activity mediated the increased rate of glucose phosphorylation. These findings indicate that apoA-I improves glucose disposal in db/db mice by improving insulin sensitivity and enhancing glucose phosphorylation.

  9. Cholesterol Efflux Capacity of Apolipoprotein A-I Varies with the Extent of Differentiation and Foam Cell Formation of THP-1 Cells

    PubMed Central

    Yano, Kouji; Sato, Megumi; Yoshimoto, Akira; Ichimura, Naoya; Kameda, Takahiro; Kubota, Tetsuo

    2016-01-01

    Apolipoprotein A-I (apoA-I), the main protein component of high-density lipoprotein (HDL), has many protective functions against atherosclerosis, one of them being cholesterol efflux capacity. Although cholesterol efflux capacity measurement is suggested to be a key biomarker for evaluating the risk of development of atherosclerosis, the assay has not been optimized till date. This study aims at investigating the effect of different states of cells on the cholesterol efflux capacity. We also studied the effect of apoA-I modification by homocysteine, a risk factor for atherosclerosis, on cholesterol efflux capacity in different states of cells. The cholesterol efflux capacity of apoA-I was greatly influenced by the extent of differentiation of THP-1 cells and attenuated by excessive foam cell formation. N-Homocysteinylated apoA-I indicated a lower cholesterol efflux capacity than normal apoA-I in the optimized condition, whereas no significant difference was observed in the cholesterol efflux capacity between apoA-I in the excessive cell differentiation or foam cell formation states. These results suggest that cholesterol efflux capacity of apoA-I varies depending on the state of cells. Therefore, the cholesterol efflux assay should be performed using protocols optimized according to the objective of the experiment. PMID:27957343

  10. Apolipoprotein A-I and its mimetics for the treatment of atherosclerosis

    PubMed Central

    Smith, Jonathan D

    2011-01-01

    Although statin treatment leads consistently to a reduction in major adverse coronary events and death in clinical trials, approximately 60 to 70% residual risk of these outcomes still remains. One frontier of investigational drug research is treatment to increase HDL, the ‘good cholesterol’ that is associated with a reduced risk of coronary artery disease. HDL and its major protein apolipoprotein A-I (apoAI) are protective against atherosclerosis through several mechanisms, including the ability to mediate reverse cholesterol transport. This review focuses on the preclinical and clinical findings for two types of therapies for the treatment of atherosclerosis: apoAI-containing compounds and apoAI mimetic peptides. Both of these therapies have excellent potential to be useful clinically to promote atherosclerosis regression and stabilize existing plaques, but significant hurdles must be overcome in order to develop these approaches into safe and effective therapies. PMID:20730693

  11. Apolipoprotein A-I enhances proliferation of human endothelial progenitor cells and promotes angiogenesis through the cell surface ATP synthase.

    PubMed

    González-Pecchi, Valentina; Valdés, Sara; Pons, Véronique; Honorato, Paula; Martinez, Laurent O; Lamperti, Liliana; Aguayo, Claudio; Radojkovic, Claudia

    2015-03-01

    Human endothelial progenitor cells (hEPC) correspond to a subtype of stem cells which, in the presence of angiogenic stimuli, can be mobilized from bone marrow to circulation and then recruited to the damaged endothelium, where they differentiate into mature endothelial cells. High-density lipoproteins (HDL) increase the level and functionality (proliferation, migration, differentiation, angiogenesis capacity) of circulating hEPC; however, the contribution of receptors for HDL and/or apolipoprotein A-I (apoA-I), the main HDL apolipoprotein, in these effects is still unclear. On mature endothelial cells, the cell surface F1-ATP synthase has been previously characterized as a high affinity receptor of apoA-I, whereas the scavenger receptor SR-BI mainly binds with fully lipidated HDL and displays a poor affinity for lipid-free apoA-I. Furthermore, it was shown that apoA-I binding to surface ATP synthase on mature endothelial cells promotes cell proliferation, whereas inhibits apoptosis. In this work, we aimed to determine the effect of apoA-I in the proliferation and the angiogenic capacity of early hEPC, and the contribution of the cell surface ATP synthase in these events. We first evidenced that early hEPC express the ATP synthase at the surface of nonpermeabilized cells, where it is not colocalized with MitoTracker, a mitochondria marker. ApoA-I (50 μg/mL) increases hEPC proliferation (+14.5%, p<0.001) and potentiates the effect of hEPC on a cellular model of angiogenesis, with an increase of +31% (p<0.01) in branch point counting and in tubule length. These effects of apoA-I were totally reversed in the presence of ATP synthase inhibitors, such as IF1 or oligomycin, whereas the inhibition of the HDL receptor, SR-BI, partially inhibits these events. These results provide the first evidence that surface ATP synthase is expressed on early hEPC, where it mediates apoA-I effects in hEPC proliferation and in angiogenesis. This knowledge could be helpful for future

  12. Interaction of Human Apolipoprotein A-I with Model Membranes Exhibiting Lipid Domains

    PubMed Central

    Arnulphi, Cristina; Sánchez, Susana A.; Tricerri, M. Alejandra; Gratton, Enrico; Jonas, Ana

    2005-01-01

    Several mechanisms for cell cholesterol efflux have been proposed, including membrane microsolubilization, suggesting that the existence of specific domains could enhance the transfer of lipids to apolipoproteins. In this work isothermal titration calorimetry, circular dichroism spectroscopy, and two-photon microscopy are used to study the interaction of lipid-free apolipoprotein A-I (apoA-I) with small unilamellar vesicles (SUVs) of 1-palmitoyl, 2-oleoyl phosphatidylcholine (POPC) and sphingomyelin (SM), with and without cholesterol. Below 30°C the calorimetric results show that apoA-I interaction with POPC/SM SUVs produces an exothermic reaction, characterized as nonclassical hydrophobic binding. The heat capacity change (ΔCp°) is small and positive, whereas it was larger and negative for pure POPC bilayers, in the absence of SM. Inclusion of cholesterol in the membranes induces changes in the observed thermodynamic pattern of binding and counteracts the formation of α-helices in the protein. Above 30°C the reactions are endothermic. Giant unilamellar vesicles (GUVs) of identical composition to the SUVs, and two-photon fluorescence microscopy techniques, were utilized to further characterize the interaction. Fluorescence imaging of the GUVs indicates coexistence of lipid domains under 30°C. Binding experiments and Laurdan generalized-polarization measurements suggest that there is no preferential binding of the labeled apoA-I to any particular domain. Changes in the content of α-helix, binding, and fluidity data are discussed in the framework of the thermodynamic parameters. PMID:15849246

  13. Effect of amino acid distribution of amphipathic helical peptide derived from human apolipoprotein A-I on membrane curvature sensing.

    PubMed

    Tanaka, Masafumi; Takamura, Yuki; Kawakami, Toru; Aimoto, Saburo; Saito, Hiroyuki; Mukai, Takahiro

    2013-03-01

    Amphipathic helix, which senses membrane curvature, is of growing interest. Here we explore the effect of amino acid distribution of amphipathic helical peptide derived from the C-terminal region (residues 220-241) of human apolipoprotein (apo) A-I on membrane curvature sensing. This peptide preferred a curved membrane in a manner similar to full-length apoA-I, although its model peptide did not sense membrane curvature. Substitution of several residues both on the polar and non-polar faces of the amphipathic helix had no significant effect on sensing, suggestive of the elaborate molecular architecture in the C-terminal helical region of apoA-I to exert lipid efflux function. Copyright © 2013 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  14. Contribution of apolipoprotein A-I to the reduction in high-sensitivity C-reactive protein levels by different statins: comparative study of pitavastatin and atorvastatin.

    PubMed

    Tani, Shigemasa; Takahashi, Atsuhiko; Nagao, Ken; Hirayama, Atsushi

    2015-11-01

    Recently, investigation may have focused on modification of apolipoprotein A-I (apoA-I) associated with anti-inflammatory effect for the potential prevention of cardiovascular events. The purpose of this study was to evaluate the effects of atorvastatin and pitavastatin on serum apoA-I levels and to investigate the role of apoA-I in the anti-inflammatory effect of statin. We conducted a 6-month, prospective, randomized, open-label study in which we assigned hypercholesterolemic patients to a pitavastatin group (n = 52; 2 mg/day) or an atorvastatin group (n = 52; 10 mg/day) to investigate the effects of these two statins on the serum apoA-I levels and serum high-sensitivity C-reactive protein (hs-CRP) levels. There were no significant differences between the two groups in the changes in the low-density lipoprotein cholesterol, high-density lipoprotein cholesterol (HDL-C), or hs-CRP levels, but the change in apoA-I in the pitavastatin group was significantly greater than in the atorvastatin group (5.3 vs. 1.4 %; p = 0.0001). A stepwise regression analysis revealed that the percent change in (Δ) serum apoA-I level was an independent predictor of the Δ serum hs-CRP (standard correlation coefficient = -0.198; p = 0.047). However, there was a significant negative correlation between the Δ apoA-I levels and Δ hs-CRP levels in the pitavastatin group (r = -0.283, p = 0.042), but not the atorvastatin group (r = -0.133, p = 0.356). The results suggest that the contribution of apoA-I to the reduction in serum hs-CRP levels by these two statins may be different. A decrease in hs-CRP level accompanied by an increase in apoA-I level may be involved in the pleiotropic effects of pitavastatin.

  15. Stimulation of Hepatic Apolipoprotein A-I Production by Novel Thieno-Triazolodiazepines: Roles of the Classical Benzodiazepine Receptor, PAF Receptor, and Bromodomain Binding

    PubMed Central

    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. PMID:25278768

  16. Stimulation of Hepatic Apolipoprotein A-I Production by Novel Thieno-Triazolodiazepines: Roles of the Classical Benzodiazepine Receptor, PAF Receptor, and Bromodomain Binding.

    PubMed

    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.

  17. High level of serum apolipoprotein A-I is a favorable prognostic factor for overall survival in esophageal squamous cell carcinoma.

    PubMed

    Wang, Xue-Ping; Li, Xiao-Hui; Zhang, Lin; Lin, Jian-Hua; Huang, Hao; Kang, Ting; Mao, Min-Jie; Chen, Hao; Zheng, Xin

    2016-07-21

    Noninvasive prognostic tools for esophageal squamous cell carcinoma (ESCC) are urgently needed. Serum lipids and lipoproteins are used for the prognosis of certain diseases; however, the prognostic value of serum apolipoprotein A-I (ApoA-I) in ESCC has not been described. Pre-treatment serum lipids and lipoprotein concentrations (including ApoA-I, Apo-B, HDL-C, LDL-C, TC and TG) were analyzed retrospectively and compared between 210 patients with ESCC and 219 healthy controls. The prognostic significance of serum lipids and lipoproteins was determined by univariate and multivariate Cox hazard models in ESCC. Clinical characteristics (age, sex, pT status, pN status, pM status, pTNM status, histological differentiation or alcohol index) had no influence on baseline ApoA-I level. Serum ApoA-I, HDL-C, LDL-C, and TC levels were significantly lower and Apo-B was significantly higher in ESCC patients than in normal controls. On univariate analysis, ApoA-I, alcohol index, pT status, pN status and pTNM status were associated with significantly poor survival, and ApoA-I (p = 0.039), alcohol index (p = 0.037) and pTNM status (p = 0.000) were identified as prognostic factors associated with shorter survival in the multivariate analysis. Overall survival was shorter in ESCC patients with decreased pre-treatment ApoA-I levels. Our findings suggest that serum ApoA-I level should be evaluated as a predictor of survival in patients with ESCC.

  18. Glycation of Apoprotein A-I Is Associated With Coronary Artery Plaque Progression in Type 2 Diabetic Patients

    PubMed Central

    Pu, Li Jin; Lu, Lin; Zhang, Rui Yan; Du, Run; Shen, Ying; Zhang, Qi; Yang, Zheng Kun; Chen, Qiu Jing; Shen, Wei Feng

    2013-01-01

    OBJECTIVE To investigate whether glycation level of apoprotein (apo)A-I is associated with coronary artery disease (CAD) and plaque progression in patients with type 2 diabetes. RESEARCH DESIGN AND METHODS Among 375 consecutive type 2 diabetic patients undergoing quantitative coronary angiography (QCA) and intravascular ultrasound (IVUS), 82 patients with nonsignificant stenosis (luminal diameter narrowing <30% [group I]) and 190 patients with significant CAD (luminal diameter stenosis ≥70% [group II]) were included for analysis of apoA-I glycation level and serum activity of lecithin: cholesterol acyltransferase (LCAT). The control group had 136 healthy subjects. At the 1-year follow-up, angiography and IVUS were repeated mainly in group II patients for plaque progression assessment. RESULTS Relative intensity of apoA-I glycation by densitometry was increased, and serum LCAT activity was decreased stepwise across groups control, I, and II. These two measurements were associated with the number of diseased coronary arteries and extent index in group II. During 1-year follow-up, QCA detected 45 patients with plaque progression in 159 subjects, and IVUS found 38 patients with plaque progression in 127 subjects. Baseline relative intensity of apoA-I glycation was significantly increased in patients with plaque progression compared with those without, with values associated with changes in QCA and IVUS measurements. Multivariable regression analysis revealed that baseline relative intensity of apoA-I glycation was an independent determinant of CAD and plaque progression in type 2 diabetic patients. CONCLUSIONS ApoA-I glycation level is associated with the severity of CAD and coronary artery plaque progression in type 2 diabetic patients. PMID:23230102

  19. A novel mutation of the apolipoprotein A-I gene in a family with familial combined hyperlipidemia.

    PubMed

    Pisciotta, Livia; Fasano, Tommaso; Calabresi, Laura; Bellocchio, Antonella; Fresa, Raffaele; Borrini, Claudia; Calandra, Sebastiano; Bertolini, Stefano

    2008-05-01

    We report a large family in which four members showed a plasma lipid profile consistent with the clinical diagnosis of familial combined hyperlipidemia (FCHL). One of these patients was found to have markedly reduced HDL cholesterol (HDL-C) (0.72 mmol/l) and Apo A-I (72 mg/dl) levels, a condition suggestive of the presence of a mutation in one of the HDL-related genes. The analysis of APOA1 gene revealed that this patient was heterozygous for a cytosine insertion in exon 3 (c.49-50 ins C), resulting in a frame-shift and premature stop codon at position 26 of pro-Apo A-I (Q17PFsX10). This novel mutation, which prevents the synthesis of Apo A-I, was also found in four family members, including three siblings and the daughter of the proband. Carriers of Apo A-I mutation had significantly lower HDL-C and Apo A-I than non-carriers family members (0.77+/-0.15 mmol/l vs. 1.15+/-0.20 mmol/l, P<0.005; 71.4+/-9.1mg/dl vs. 134.0+/-14.7 mg/dl, P<0.005, respectively). Two of the APOA1 mutation carriers, who were also heavy smokers, had fibrous plaques in the carotid arteries causing mild stenosis (20%). The intimal-media thickness in the two other adult carriers was within the normal range. The other non-carriers family members with FCHL had either overt vascular disease or carotid atherosclerosis at ultrasound examination. This observation suggests that the low HDL-C/low Apo A-I phenotype may result from a genetic defect directly affecting HDL metabolism, even in the context of a dyslipidemia which, like FCHL, is associated with low plasma HDL-C.

  20. Increased Binding of Apolipoproteins A-I and E4 to Triglyceride-Rich Lipoproteins is linked to Induction of Hypertriglyceridemia.

    PubMed

    Gorshkova, Irina N; Atkinson, David

    2017-01-01

    Hypertriglyceridemia (HTG) is an independent factor of atherosclerotic cardiovascular disease and a hallmark of many metabolic disorders. However, the molecular etiology of HTG is still largely unknown. In mice, severe HTG may be induced by expression of specific mutants of apolipoprotein (apo) A-I or wild type (WT) apoE4. Expression of a certain apoE4 mutant results in mild HTG, while expression of another apoE4 mutant or WT apoA-I results in normal plasma triglyceride (TG) levels. Biophysical studies of the apoA-I and apoE4 forms associated with HTG help better understand the molecular mechanisms of induction of HTG by these proteins. The studies show that the apoA-I and apoE4 forms that induce HTG have a destabilized and more loosely folded conformation in solution than their counterparts not associated with HTG. Disruption of the protein salt bridge networks by the mutations is likely responsible for the observed structural changes. Each apoA-I and apoE4 form that induced HTG show enhanced binding to model TG-rich particles. HTG appeared to positively correlate with the apolipoprotein ability to bind to TG-rich particles. This implies that in vivo, the conformational changes in the apolipoproteins that induce HTG facilitate their binding to plasma TG-rich lipoproteins. We discuss metabolic pathways leading to the development of HTG that may result from enhanced binding of the apolipoproteins to TG-rich lipoproteins in circulation. While various factors may be involved in the development of HTG in humans, it is possible that structural alterations that increase affinity of apolipoproteins to TG-rich lipoproteins may contribute to some cases of this disorder.

  1. Amyloidogenic Propensity of a Natural Variant of Human Apolipoprotein A-I: Stability and Interaction with Ligands

    PubMed Central

    Rosú, Silvana A.; Rimoldi, Omar J.; Prieto, Eduardo D.; Curto, Lucrecia M.; Delfino, José M.

    2015-01-01

    A number of naturally occurring mutations of human apolipoprotein A-I (apoA-I) have been associated with hereditary amyloidoses. The molecular mechanisms involved in amyloid-associated pathology remain largely unknown. Here we examined the effects of the Arg173Pro point mutation in apoA-I on the structure, stability, and aggregation propensity, as well as on the ability to bind to putative ligands. Our results indicate that the mutation induces a drastic loss of stability, and a lower efficiency to bind to phospholipid vesicles at physiological pH, which could determine the observed higher tendency to aggregate as pro-amyloidogenic complexes. Incubation under acidic conditions does not seem to induce significant desestabilization or aggregation tendency, neither does it contribute to the binding of the mutant to sodium dodecyl sulfate. While the binding to this detergent is higher for the mutant as compared to wt apoA-I, the interaction of the Arg173Pro variant with heparin depends on pH, being lower at pH 5.0 and higher than wt under physiological pH conditions. We suggest that binding to ligands as heparin or other glycosaminoglycans could be key events tuning the fine details of the interaction of apoA-I variants with the micro-environment, and probably eliciting the toxicity of these variants in hereditary amyloidoses. PMID:25950566

  2. Structural basis for distinct functions of the naturally occurring Cys mutants of human apolipoprotein A-I[S

    PubMed Central

    Gursky, Olga; Jones, Martin K.; Mei, Xiaohu; Segrest, Jere P.; Atkinson, David

    2013-01-01

    HDL removes cell cholesterol and protects against atherosclerosis. ApoA-I provides a flexible structural scaffold and an important functional ligand on the HDL surface. We propose structural models for apoA-IMilano (R173C) and apoA-IParis (R151C) mutants that show high cardioprotection despite low HDL levels. Previous studies established that two apoA-I molecules encircle HDL in an antiparallel, helical double-belt conformation. Recently, we solved the atomic structure of lipid-free Δ(185–243)apoA-I and proposed a conformational ensemble for apoA-IWT on HDL. Here we modify this ensemble to understand how intermolecular disulfides involving C173 or C151 influence protein conformation. The double-belt conformations are modified by belt rotation, main-chain unhinging around Gly, and Pro-induced helical bending, and they are verified by comparison with previous experimental studies and by molecular dynamics simulations of apoA-IMilano homodimer. In our models, the molecular termini repack on various-sized HDL, while packing around helix-5 in apoA-IWT, helix-6 in apoA-IParis, or helix-7 in apoA-IMilano homodimer is largely conserved. We propose how the disulfide-induced constraints alter the protein conformation and facilitate dissociation of the C-terminal segment from HDL to recruit additional lipid. Our models unify previous studies of apoA-IMilano and demonstrate how the mutational effects propagate to the molecular termini, altering their conformations, dynamics, and function. PMID:24038317

  3. Disruption of human plasma high-density lipoproteins by streptococcal serum opacity factor requires labile apolipoprotein A-I.

    PubMed

    Han, Mikyung; Gillard, Baiba K; Courtney, Harry S; Ward, Kathryn; Rosales, Corina; Khant, Htet; Ludtke, Steven J; Pownall, Henry J

    2009-02-24

    Human plasma high-density lipoproteins (HDL), the primary vehicle for reverse cholesterol transport, are the target of serum opacity factor (SOF), a virulence determinant of Streptococcus pyogenes that turns serum opaque. HDL comprise a core of neutral lipidscholesteryl esters and some triglyceridesurrounded by a surface monolayer of cholesterol, phospholipids, and specialized proteins [apolipoproteins (apos) A-I and A-II]. A HDL is an unstable particle residing in a kinetic trap from which it can escape via chaotropic, detergent, or thermal perturbation. Recombinant (r) SOF catalyzes the transfer of nearly all neutral lipids of approximately 100,000 HDL particles (D approximately 8.5 nm) into a single, large cholesteryl ester-rich microemulsion (CERM; D > 100 nm), leaving a new HDL-like particle [neo HDL (D approximately 5.8 nm)] while releasing lipid-free (LF) apo A-I. CERM formation and apo A-I release have similar kinetics, suggesting parallel or rapid consecutive steps. By using complementary physicochemical methods, we have refined the mechanistic model for HDL opacification. According to size exclusion chromatography, a HDL containing nonlabile apo A-I resists rSOF-mediated opacification. On the basis of kinetic cryo-electron microscopy, rSOF (10 nM) catalyzes the conversion of HDL (4 microM) to neo HDL via a stepwise mechanism in which intermediate-sized particles are seen. Kinetic turbidimetry revealed opacification as a rising exponential reaction with a rate constant k of (4.400 +/- 0.004) x 10(-2) min(-1). Analysis of the kinetic data using transition state theory gave an enthalpy (DeltaH()), entropy (DeltaS(++)), and free energy (DeltaG()) of activation of 73.9 kJ/mol, -66.87 J/K, and 94.6 kJ/mol, respectively. The free energy of activation for opacification is nearly identical to that for the displacement of apo A-I from HDL by guanidine hydrochloride. We conclude that apo A-I lability is required for HDL opacification, LF apo A-I desorption is the

  4. A Systematic Investigation of Structure/Function Requirements for the Apolipoprotein A-I/Lecithin Cholesterol Acyltransferase Interaction Loop of High-density Lipoprotein.

    PubMed

    Gu, Xiaodong; Wu, Zhiping; Huang, Ying; Wagner, Matthew A; Baleanu-Gogonea, Camelia; Mehl, Ryan A; Buffa, Jennifer A; DiDonato, Anthony J; Hazen, Leah B; Fox, Paul L; Gogonea, Valentin; Parks, John S; DiDonato, Joseph A; Hazen, Stanley L

    2016-03-18

    The interaction of lecithin-cholesterol acyltransferase (LCAT) with apolipoprotein A-I (apoA-I) plays a critical role in high-density lipoprotein (HDL) maturation. We previously identified a highly solvent-exposed apoA-I loop domain (Leu(159)-Leu(170)) in nascent HDL, the so-called "solar flare" (SF) region, and proposed that it serves as an LCAT docking site (Wu, Z., Wagner, M. A., Zheng, L., Parks, J. S., Shy, J. M., 3rd, Smith, J. D., Gogonea, V., and Hazen, S. L. (2007) Nat. Struct. Mol. Biol. 14, 861-868). The stability and role of the SF domain of apoA-I in supporting HDL binding and activation of LCAT are debated. Here we show by site-directed mutagenesis that multiple residues within the SF region (Pro(165), Tyr(166), Ser(167), and Asp(168)) of apoA-I are critical for both LCAT binding to HDL and LCAT catalytic efficiency. The critical role for possible hydrogen bond interaction at apoA-I Tyr(166) was further supported using reconstituted HDL generated from apoA-I mutants (Tyr(166) → Glu or Asn), which showed preservation in both LCAT binding affinity and catalytic efficiency. Moreover, the in vivo functional significance of NO2-Tyr(166)-apoA-I, a specific post-translational modification on apoA-I that is abundant within human atherosclerotic plaque, was further investigated by using the recombinant protein generated from E. coli containing a mutated orthogonal tRNA synthetase/tRNACUA pair enabling site-specific insertion of the unnatural amino acid into apoA-I. NO2-Tyr(166)-apoA-I, after subcutaneous injection into hLCAT(Tg/Tg), apoA-I(-/-) mice, showed impaired LCAT activation in vivo, with significant reduction in HDL cholesteryl ester formation. The present results thus identify multiple structural features within the solvent-exposed SF region of apoA-I of nascent HDL essential for optimal LCAT binding and catalytic efficiency. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

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

    PubMed

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

    2016-08-01

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

  6. High yield of recombinant human Apolipoprotein A-I expressed in Pichia pastoris by using mixed-mode chromatography.

    PubMed

    Narasimhan Janakiraman, Vignesh; Noubhani, Abdelmajid; Venkataraman, Krishnan; Vijayalakshmi, Mookambeswaran; Santarelli, Xavier

    2016-01-01

    A vast majority of the cardioprotective properties exhibited by High-Density Lipoprotein (HDL) is mediated by its major protein component Apolipoprotein A-I (ApoA1). In order to develop a simplified bioprocess for producing recombinant human Apolipoprotein A-I (rhApoA1) in its near-native form, rhApoA1was expressed without the use of an affinity tag in view of its potential therapeutic applications. Expressed in Pichia pastoris at expression levels of 58.2 mg ApoA1 per litre of culture in a reproducible manner, the target protein was purified by mixed-mode chromatography using Capto™ MMC ligand with a purity and recovery of 84% and 68%, respectively. ApoA1 purification was scaled up to Mixed-mode Expanded Bed Adsorption chromatography to establish an 'on-line' process for the efficient capture of rhApoA1 directly from the P. pastoris expression broth. A polishing step using anion exchange chromatography enabled the recovery of ApoA1 up to 96% purity. Purified ApoA1 was identified and verified by RPLC-ESI-Q-TOF mass spectrometry. This two-step process would reduce processing times and therefore costs in comparison to the twelve-step procedure currently used for recovering rhApoA1 from P. pastoris. Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

    PubMed

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

    2001-09-01

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

  8. Link Between ER-Stress, PPAR-Alpha Activation, and BET Inhibition in Relation to Apolipoprotein A-I Transcription in HepG2 Cells.

    PubMed

    van der Krieken, Sophie E; Popeijus, Herman E; Mensink, Ronald P; Plat, Jogchum

    2017-08-01

    Activating transcription factor peroxisome proliferator-activated receptor alpha (PPARα) may increase apoA-I transcription. Furthermore, Bromodomain and Extra-Terminal domain (BET) protein inhibitors increase, whereas Endoplasmic Reticulum (ER) stress decreases apoA-I transcription. We examined possible links between these processes as related to apoA-I transcription in HepG2 cells. JQ1(+), thapsigargin, and GW7647 were used to induce, respectively BET inhibition, ER-stress, and PPARα activation. Expression of ER-stress markers (CHOP, XBP1s) was analyzed by western blotting. PPARα, KEAP1 (marker for BET inhibition), and apoA-I mRNAs were measured using qPCR. ER-stress and BET inhibition both decreased PPARα mRNA expression and activity, but did not interfere with each other, as ER-stress did not change KEAP1 and JQ1(+) did not influence ER-stress marker production. Interestingly, PPARα activation and BET-inhibition diminished ER-stress marker production and rescued apoA-I transcription during existing ER-stress. We conclude that the ER-stress mediated reduction in apoA-I transcription could be partly mediated via the inhibition of PPARα mRNA expression and activity. In addition, BET inhibition increased apoA-I transcription, even if PPARα production and activity were decreased. Finally, both BET inhibition and PPARα activation ameliorate the apoA-I lowering effect of ER-stress and are therefore interesting targets to elevate apoA-I transcription. J. Cell. Biochem. 118:2161-2167, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  9. Effect of niacin on high-density lipoprotein apolipoprotein A-I kinetics in statin-treated patients with type 2 diabetes mellitus.

    PubMed

    Pang, Jing; Chan, Dick C; Hamilton, Sandra J; Tenneti, Vijay S; Watts, Gerald F; Barrett, P Hugh R

    2014-02-01

    To investigate the effect of extended-release (ER) niacin on the metabolism of high-density lipoprotein (HDL) apolipoprotein A-I (apoA-I) in men with type 2 diabetes mellitus on a background of optimal statin therapy. Twelve men with type 2 diabetes mellitus were recruited for a randomized, crossover design trial. Patients were randomized to rosuvastatin or rosuvastatin plus ER niacin for 12 weeks and then crossed over to the alternate therapy after a 3-week washout period. Metabolic studies were performed at the end of each treatment period. HDL apoA-I kinetics were measured after a standardized liquid mixed meal and a bolus injection of d3-leucine for 96 hours. Compartmental analysis was used to model the data. ER niacin significantly decreased plasma triglyceride, plasma cholesterol, non-HDL cholesterol, low-density lipoprotein cholesterol, and apoB (all P<0.05) and significantly increased HDL cholesterol and apoA-I concentrations (P<0.005 and P<0.05, respectively). ER niacin also significantly increased HDL apoA-I pool size (6,088 ± 292 versus 5,675 ± 305 mg; P<0.001), and this was attributed to a lower HDL apoA-I fractional catabolic rate (0.33 ± 0.01 versus 0.37 ± 0.02 pools/d; P<0.005), with no significant changes in HDL apoA-I production (20.93 ± 0.63 versus 21.72 ± 0.85 mg/kg per day; P=0.28). ER niacin increases HDL apoA-I concentration in statin-treated subjects with type 2 diabetes mellitus by lowering apoA-I fractional catabolic rate. The effect on HDL metabolism was independent of the reduction in plasma triglyceride with ER niacin treatment. Whether this finding applies to other dyslipidemic populations remains to be investigated.

  10. Apolipoprotein A-I Modulates Processes Associated with Diet-Induced Nonalcoholic Fatty Liver Disease in Mice

    PubMed Central

    Karavia, Eleni A; Papachristou, Dionysios J; Liopeta, Kassiani; Triantaphyllidou, Irene-Eva; Dimitrakopoulos, Odyssefs; Kypreos, Kyriakos E

    2012-01-01

    Apolipoprotein A-I (apoA-I) is the main protein of high-density lipoprotein (HDL). We investigated the involvement of apoA-I in diet-induced accumulation of triglycerides in hepatocytes and its potential role in the treatment of nonalcoholic fatty liver disease (NAFLD). ApoA-I–deficient (apoA-I−/−) mice showed increased diet-induced hepatic triglyceride deposition and disturbed hepatic histology while they exhibited reduced glucose tolerance and insulin sensitivity. Quantification of FASN (fatty acid synthase 1), DGAT-1 (diacylglycerol O-acyltransferase 1), and PPARγ (peroxisome proliferator-activated receptor γ) mRNA expression suggested that the increased hepatic triglyceride content of the apoA-I−/− mice was not due to de novo synthesis of triglycerides. Similarly, metabolic profiling did not reveal differences in the energy expenditure between the two mouse groups. However, apoA-I−/− mice exhibited enhanced intestinal absorption of dietary triglycerides (3.6 ± 0.5 mg/dL/min for apoA-I−/− versus 2.0 ± 0.7 mg/dL/min for C57BL/6 mice, P < 0.05), accelerated clearance of postprandial triglycerides and a reduced rate of hepatic very low density lipoprotein (VLDL) triglyceride secretion (9.8 ± 1.1 mg/dL/min for apoA-I−/− versus 12.5 ± 1.3 mg/dL/min for C57BL/6 mice, P < 0.05). In agreement with these findings, adenovirus-mediated gene transfer of apoA-IMilano in apoA-I−/− mice fed a Western-type diet for 12 wks resulted in a significant reduction in hepatic triglyceride content and an improvement of hepatic histology and architecture. Our data extend the current knowledge on the functions of apoA-I, indicating that in addition to its well-established properties in atheroprotection, it is also an important modulator of processes associated with diet-induced hepatic lipid deposition and NAFLD development in mice. Our findings raise the interesting possibility that expression of therapeutic forms of apoA-I by gene therapy approaches may

  11. Deficiency in apolipoprotein A-I ablates the pharmacological effects of metformin on plasma glucose homeostasis and hepatic lipid deposition.

    PubMed

    Karavia, Eleni A; Hatziri, Aikaterini; Kalogeropoulou, Christina; Papachristou, Nikolaos I; Xepapadaki, Eva; Constantinou, Caterina; Natsos, Anastasios; Petropoulou, Peristera-Ioanna; Sasson, Shlomo; Papachristou, Dionysios J; Kypreos, Kyriakos E

    2015-11-05

    Recently, we showed that deficiency in apolipoprotein A-I (ApoA-I) sensitizes mice to diet-induced obesity, glucose intolerance and NAFLD. Here we investigated the potential involvement of ApoA-I in the pharmacological effects of metformin on glucose intolerance and NAFLD development. Groups of apoa1-deficient (apoa1(-/-)) and C57BL/6 mice fed western-type diet were either treated with a daily dose of 300 mg/kg metformin for 18 weeks or left untreated for the same period. Then, histological and biochemical analyses were performed. Metformin treatment led to a comparable reduction in plasma insulin levels in both C57BL/6 and apoa1(-/-) mice following intraperitoneal glucose tolerance test. However, only metformin-treated C57BL/6 mice maintained sufficient peripheral insulin sensitivity to effectively clear glucose following the challenge, as indicated by a [(3)H]-2-deoxy-D-glucose uptake assay in isolated soleus muscle. Similarly, deficiency in ApoA-I ablated the effect of metformin on hepatic lipid deposition and NAFLD development. Gene expression analysis indicated that the effects of ApoA-I on metformin treatment may be independent of adenosine monophosphate-activated protein kinase (AMPK) activation and de novo lipogenesis. Interestingly, metformin treatment reduced mitochondrial oxidative phosphorylation function only in apoa1(-/-) mice. Our data show that the role of ApoA-I in diabetes extends to the modulation of the pharmacological actions of metformin, a common drug for the treatment of type 2 diabetes. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. High-density lipoprotein 3 and apolipoprotein A-I alleviate platelet storage lesion and release of platelet extracellular vesicles.

    PubMed

    Pienimaeki-Roemer, Annika; Fischer, Astrid; Tafelmeier, Maria; Orsó, Evelyn; Konovalova, Tatiana; Böttcher, Alfred; Liebisch, Gerhard; Reidel, Armin; Schmitz, Gerd

    2014-09-01

    Stored platelet (PLT) concentrates (PLCs) for transfusion develop a PLT storage lesion (PSL), decreasing PLT viability and function with profound lipidomic changes and PLT extracellular vesicle (PL-EV) release. High-density lipoprotein 3 (HDL3 ) improves PLT homeostasis through silencing effects on PLT activation in vivo. This prompted us to investigate HDL3 and apolipoprotein A-I (apoA-I) as PSL-antagonizing agents. Healthy donor PLCs were split into low-volume standard PLC storage bags and incubated with native (n)HDL3 or apoA-I from plasma ethanol fractionation (precipitate IV) for 5 days under standard blood banking conditions. Flow cytometry, Born aggregometry, and lipid mass spectrometry were carried out to analyze PL-EV release, PLT aggregation, agonist-induced PLT surface marker expression, and PLT and plasma lipid compositions. Compared to control, added nHDL3 and apoA-I significantly reduced PL-EV release by up to -62% during 5 days, correlating with the added apoA-I concentration. At the lipid level, nHDL3 and apoA-I antagonized PLT lipid loss (+12%) and decreased cholesteryl ester (CE)/free cholesterol (FC) ratios (-69%), whereas in plasma polyunsaturated/saturated CE ratios increased (+3%) and CE 16:0/20:4 ratios decreased (-5%). Administration of nHDL3 increased PLT bis(monoacylglycero)phosphate/phosphatidylglycerol (+102%) and phosphatidic acid/lysophosphatidic acid (+255%) ratios and improved thrombin receptor-activating peptide 6-induced PLT aggregation (+5%). nHDL3 and apoA-I improve PLT membrane homeostasis and intracellular lipid processing and increase CE efflux, antagonizing PSL-related reduction in PLT viability and function and PL-EV release. We suggest uptake and catabolism of nHDL3 into the PLT open canalicular system. As supplement in PLCs, nHDL3 or apoA-I from Fraction IV of plasma ethanol fractionation have the potential to improve PLC quality to prolong storage. © 2014 AABB.

  13. [Screening and identification of apolipoprotein A-I as a potential marker for hepatoblastoma in children].

    PubMed

    Guo, Li-Hua; Zhao, Wei; Zhang, Jun-Jie; Zhang, Qian; Fan, Ying-Zhong; Wang, Jia-Xiang

    2016-12-01

    To screen and identify serum biomarkers for childhood hepatoblastoma (HB). The serum samples from 30 children with hepatoblastoma (HB), 20 children with systemic inflammatory response syndrome, and 20 normal children were treated with magnetic bead-based weak cation exchange chromatography. The platform of surface-enhanced laser desorption/ionization-time of flight-mass spectrometry (SELDI-TOF-MS) was used to eliminate the interference of inflammatory factors and to screen out the differentially expressed proteins in serum between tumor group and normal group. After the purification and separation of target proteins were performed using sodium dodecyl sulfate-polyacrylamide gel electrophoresis, matrix-assisted laser desorption/ionization-time of flight-mass spectrometry was used to determine their amino acid sequences. The SwissProt database was searched for matched proteins. Finally, real-time PCR and ELISA were used to verify and measure the expression of target proteins. After SELDI-TOF-MS was used for screening and elimination of the interference of inflammatory factors, a differentially expression protein with a mass-to-charge ratio of 9 348 Da was found in serum between HB group and normal group, and the HB group had significantly lower expression of this protein than the normal group (p<0.05). This protein was identified as apolipoprotein A-1 (Apo A-I). Real-time PCR and ELISA verified the low mRNA and protein expression of Apo A-I in serum in the HB group and high expression in serum in the normal group. Apo A-I can be used as a non-inflammatory protein marker for HB and has a certain value in the early diagnosis of HB.

  14. A Systematic Investigation of Structure/Function Requirements for the Apolipoprotein A-I/Lecithin Cholesterol Acyltransferase Interaction Loop of High-density Lipoprotein*

    PubMed Central

    Gu, Xiaodong; Wu, Zhiping; Huang, Ying; Wagner, Matthew A.; Baleanu-Gogonea, Camelia; Mehl, Ryan A.; Buffa, Jennifer A.; DiDonato, Anthony J.; Hazen, Leah B.; Fox, Paul L.; Gogonea, Valentin; Parks, John S.; DiDonato, Joseph A.; Hazen, Stanley L.

    2016-01-01

    The interaction of lecithin-cholesterol acyltransferase (LCAT) with apolipoprotein A-I (apoA-I) plays a critical role in high-density lipoprotein (HDL) maturation. We previously identified a highly solvent-exposed apoA-I loop domain (Leu159–Leu170) in nascent HDL, the so-called “solar flare” (SF) region, and proposed that it serves as an LCAT docking site (Wu, Z., Wagner, M. A., Zheng, L., Parks, J. S., Shy, J. M., 3rd, Smith, J. D., Gogonea, V., and Hazen, S. L. (2007) Nat. Struct. Mol. Biol. 14, 861–868). The stability and role of the SF domain of apoA-I in supporting HDL binding and activation of LCAT are debated. Here we show by site-directed mutagenesis that multiple residues within the SF region (Pro165, Tyr166, Ser167, and Asp168) of apoA-I are critical for both LCAT binding to HDL and LCAT catalytic efficiency. The critical role for possible hydrogen bond interaction at apoA-I Tyr166 was further supported using reconstituted HDL generated from apoA-I mutants (Tyr166 → Glu or Asn), which showed preservation in both LCAT binding affinity and catalytic efficiency. Moreover, the in vivo functional significance of NO2-Tyr166-apoA-I, a specific post-translational modification on apoA-I that is abundant within human atherosclerotic plaque, was further investigated by using the recombinant protein generated from E. coli containing a mutated orthogonal tRNA synthetase/tRNACUA pair enabling site-specific insertion of the unnatural amino acid into apoA-I. NO2-Tyr166-apoA-I, after subcutaneous injection into hLCATTg/Tg, apoA-I−/− mice, showed impaired LCAT activation in vivo, with significant reduction in HDL cholesteryl ester formation. The present results thus identify multiple structural features within the solvent-exposed SF region of apoA-I of nascent HDL essential for optimal LCAT binding and catalytic efficiency. PMID:26797122

  15. 22 CFR 214.13 - Responsibilities within A.I.D.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Responsibilities within A.I.D. 214.13 Section... Establishment of Advisory Committees § 214.13 Responsibilities within A.I.D. (a) The A.I.D. Office or Bureau seeking establishment of a new A.I.D. advisory committee: (1) Justifies the need for the advisory...

  16. 22 CFR 214.13 - Responsibilities within A.I.D.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 22 Foreign Relations 1 2012-04-01 2012-04-01 false Responsibilities within A.I.D. 214.13 Section... Establishment of Advisory Committees § 214.13 Responsibilities within A.I.D. (a) The A.I.D. Office or Bureau seeking establishment of a new A.I.D. advisory committee: (1) Justifies the need for the advisory...

  17. 22 CFR 214.13 - Responsibilities within A.I.D.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Responsibilities within A.I.D. 214.13 Section... Establishment of Advisory Committees § 214.13 Responsibilities within A.I.D. (a) The A.I.D. Office or Bureau seeking establishment of a new A.I.D. advisory committee: (1) Justifies the need for the advisory...

  18. 22 CFR 214.13 - Responsibilities within A.I.D.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Responsibilities within A.I.D. 214.13 Section... Establishment of Advisory Committees § 214.13 Responsibilities within A.I.D. (a) The A.I.D. Office or Bureau seeking establishment of a new A.I.D. advisory committee: (1) Justifies the need for the advisory...

  19. 22 CFR 214.13 - Responsibilities within A.I.D.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Responsibilities within A.I.D. 214.13 Section... Establishment of Advisory Committees § 214.13 Responsibilities within A.I.D. (a) The A.I.D. Office or Bureau seeking establishment of a new A.I.D. advisory committee: (1) Justifies the need for the advisory...

  20. Apolipoprotein A-I, A-II, and H mRNA and protein accumulation sites in the developing lung in late gestation

    PubMed Central

    2011-01-01

    Background Expression of apolipoprotein A-I (apoA-I), A-II, and H was previously observed at 16 to 50-fold higher levels in the fetal than the adult mouse lung. Here, sites of apoA-I, A-II, and H mRNA and protein accumulation were determined in mouse fetal lungs by in situ hybridization and immunohistochemistry in late gestation. Results Expression sites vary for the three genes and change for the distal epithelium before the end of the canalicular stage, thus where and when the surge of surfactant synthesis occurs. Messenger of apoH, but not those of apoA-I and A-II, was also observed in the proximal epithelium and smooth muscles surrounding arteries. In contrast to apoC-II protein, none of the three studied apolipoproteins accumulated within secretory granule-like structures. Immunohistochemistry revealed that apoA-I and apoH accumulated mainly in capillaries. Three different positive signals with the anti-apoA-II antibody were found: one transient signal in the nucleus of a portion of mesenchymal cells, a second at lower levels throughout the mesenchyme, and another in capillaries with a specific increase from gestation day 17.5/18.5. Conclusion Temporal and geographic co-expression of apoAI, AII, and H genes with surfactant production site suggests that the three apolipoproteins are secreted to play roles supporting the lung-specific surfactant lipid-related metabolism. PMID:21756353

  1. A role for apolipoprotein E, apolipoprotein A-I, and low density lipoprotein receptors in cholesterol transport during regeneration and remyelination of the rat sciatic nerve.

    PubMed Central

    Boyles, J K; Zoellner, C D; Anderson, L J; Kosik, L M; Pitas, R E; Weisgraber, K H; Hui, D Y; Mahley, R W; Gebicke-Haerter, P J; Ignatius, M J

    1989-01-01

    Recent work has demonstrated that apo E secretion and accumulation increase in the regenerating peripheral nerve. The fact that apoE, in conjunction with apoA-I and LDL receptors, participates in a well-established lipid transfer system raised the possibility that apoE is also involved in lipid transport in the injured nerve. In the present study of the crushed rat sciatic nerve, a combination of techniques was used to trace the cellular associations of apoE, apoA-I, and the LDL receptor during nerve repair and to determine the distribution of lipid at each stage. After a crush injury, as axons died and Schwann cells reabsorbed myelin, resident and monocyte-derived macrophages produced large quantities of apoE distal to the injury site. As axons regenerated in the first week, their tips contained a high concentration of LDL receptors. After axon regeneration, apoE and apoA-I began to accumulate distal to the injury site and macrophages became increasingly cholesterol-loaded. As remyelination began in the second and third weeks after injury, Schwann cells exhausted their cholesterol stores, then displayed increased LDL receptors. Depletion of macrophage cholesterol stores followed over the next several weeks. During this stage of regeneration, apoE and apoA-I were present in the extracellular matrix as components of cholesterol-rich lipoproteins. Our results demonstrate that the regenerating peripheral nerve possesses the components of a cholesterol transfer mechanism, and the sequence of events suggests that this mechanism supplies the cholesterol required for rapid membrane biogenesis during axon regeneration and remyelination. Images PMID:2493483

  2. Human apolipoprotein A-I exerts a prophylactic effect on high-fat diet-induced atherosclerosis via inflammation inhibition in a rabbit model.

    PubMed

    Li, Jiyang; Wang, Weina; Han, Lei; Feng, Meiqing; Lu, Hui; Yang, Li; Hu, Xiangxiang; Shi, Si; Jiang, Shanshan; Wang, Qian; Ye, Li

    2017-02-06

    Apolipoprotein A-I (apoA-I) is the major functional protein fraction of high-density lipoprotein. The prophylactic effect and mechanism of human apoA-I on atherosclerosis (AS) were investigated in a high-fat diet-induced AS rabbit model. The rabbits were injected with apoA-I once a week while fed high-fat diet for 20 weeks. Our results showed that apoA-I could raise the serum level of high-density lipoprotein-cholesterol and reduce those of lipid total cholesterol, triglyceride, and low-density lipoprotein-cholesterol in AS rabbits. Decreased aortic plaque area and aortic injury degree were also observed by Oil Red O staining and HE staining in apoA-I-treated high-fat diet-induced AS rabbits. Further study elucidated that apoA-I could down-regulate the expression of some inflammatory mediators including intercellular adhesion molecule type 1, vascular adhesion molecule-1 (VCAM-1), monocyte chemoattractant protein-1, tumor necrosis factor-α, interleukin-6 (IL-6), and C-reactive protein in serum and aorta of AS rabbits. In addition, real-time quantitative RT-PCR analyses showed that the apoA-I infusions decreased the mRNA levels of two pro-inflammatory molecules, i.e. nuclear factor kappa B (NF-κB) and cyclooxygenase-2 (COX-2), in aorta of AS rabbits, which was associated with a concomitant reduction in endothelial VCAM-1 and IL-6 mRNA transcription. Together, our results support the atheroprotective and prophylactic role of apoA-I in vivo, and this activity may be correlated with its anti-inflammatory effect. © The Author 2017. Published by Oxford University Press on behalf of the Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

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

    PubMed

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

    2016-07-01

    Apolipoprotein A-I (apoA-I) of HDL is central to the transport of cholesterol in circulation. ApoA-I also provides glucose control with described in vitro effects of apoA-I on β-cell insulin secretion and muscle glucose uptake. In addition, apoA-I injections in insulin-resistant diet-induced obese (DIO) mice lead to increased glucose-stimulated insulin secretion (GSIS) and peripheral tissue glucose uptake. However, the relative contribution of apoA-I as an enhancer of GSIS in vivo and as a direct stimulator of insulin-independent glucose uptake is not known. Here, DIO mice with instant and transient blockade of insulin secretion were used in glucose tolerance tests and in positron emission tomography analyses. Data demonstrate that apoA-I to an equal extent enhances GSIS and acts as peripheral tissue activator of insulin-independent glucose uptake and verify skeletal muscle as an apoA-I target tissue. Intriguingly, our analyses also identify the heart as an important target tissue for the apoA-I-stimulated glucose uptake, with potential implications in diabetic cardiomyopathy. Explorations of apoA-I as a novel antidiabetic drug should extend to treatments of diabetic cardiomyopathy and other cardiovascular diseases in patients with diabetes. © 2016 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

  4. 22 CFR 214.31 - A.I.D. Advisory Committee Representative.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 22 Foreign Relations 1 2013-04-01 2013-04-01 false A.I.D. Advisory Committee Representative. 214... MANAGEMENT Operation of Advisory Committees § 214.31 A.I.D. Advisory Committee Representative. (a) For each advisory committee used by A.I.D., the Administrator designates an A.I.D., employee to serve as the A.I.D...

  5. 22 CFR 214.31 - A.I.D. Advisory Committee Representative.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 22 Foreign Relations 1 2012-04-01 2012-04-01 false A.I.D. Advisory Committee Representative. 214... MANAGEMENT Operation of Advisory Committees § 214.31 A.I.D. Advisory Committee Representative. (a) For each advisory committee used by A.I.D., the Administrator designates an A.I.D., employee to serve as the A.I.D...

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

    USDA-ARS?s Scientific Manuscript database

    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...

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

    NASA Astrophysics Data System (ADS)

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

    2010-03-01

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

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

    PubMed

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

    1995-03-01

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

  9. Influence of route of administration and lipidation of apolipoprotein A-I peptide on pharmacokinetics and cholesterol mobilization.

    PubMed

    Tang, Jie; Li, Dan; Drake, Lindsey; Yuan, Wenmin; Deschaine, Sara; Morin, Emily E; Ackermann, Rose; Olsen, Karl; Smith, David E; Schwendeman, Anna

    2017-01-01

    apoA-I, apoA-I mimetic peptides, and their lipid complexes or reconstituted high-density lipoprotein (HDL) have been studied as treatments for various pathologies. However, consensus is lacking about the best method for administration, by intravenous (IV) or intraperitoneal (IP) routes, and formulation, as an HDL particle or in a lipid-free form. The objective of this study was to systematically examine peptide plasma levels, cholesterol mobilization, and lipoprotein remodeling in vivo following administration of lipid-free apoA-I peptide (22A) or phospholipid reconstituted 22A-sHDL by IV and IP routes. The mean circulation half-life was longer for 22A-sHDL (T1/2 = 6.27 h) than for free 22A (T1/2 = 3.81 h). The percentage of 22A absorbed by the vascular compartment after the IP dosing was ∼50% for both 22A and 22A-sHDL. The strongest pharmacologic response came from IV injection of 22A-sHDL, specifically a 5.3-fold transient increase in plasma-free cholesterol (FC) level compared with 1.3- and 1.8-fold FC increases for 22A-IV and 22A-sHDL-IP groups. Addition of either 22A or 22A-sHDL to rat plasma caused lipoprotein remodeling and appearance of a lipid-poor apoA-I. Hence, both the route of administration and the formulation of apoA-I peptide significantly affect its pharmacokinetics and pharmacodynamics. Copyright © 2017 by the American Society for Biochemistry and Molecular Biology, Inc.

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

    PubMed

    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.

  11. Sequence-specific apolipoprotein A-I effects on lecithin:cholesterol acyltransferase activity.

    PubMed

    Dergunov, Alexander D

    2013-06-01

    Existing kinetic data of cholesteryl ester formation by lecithin:cholesterol acyltransferase in discoidal high-density lipoproteins with 34 mutations of apoA-I that involved all putative helices were grouped by cluster analysis into four noncoincident regions with mutations both without any functional impairment and with profound isolated (V- and K-mutations) or common (VK-mutations) effect on V(max)(app) and K(m)(app). Data were analyzed with a new kinetic model of LCAT activity at interface that exploits the efficiency of LCAT binding to the particle, particle dimensions, and surface concentrations of phosphatidylcholine and cholesterol. V-mutations with major location in the central part and C-domain affected the second-order rate constant of cholesteryl ester formation at the solvolysis of acyl-enzyme intermediate by cholesterol as nucleophile. The central region in apoA-I sequence is suggested to influence the proper positioning of cholesterol molecule toward LCAT active center with major contribution of arginine residue(s). K-mutations with major location in N-domain may affect binding and stability of enzyme-phosphatidylcholine complex. VK-mutations may possess mixed effects; the independent binding measurement may segregate individual steps.

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

    PubMed Central

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

    2015-01-01

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

  13. The 5A apolipoprotein A-I mimetic peptide displays anti-inflammatory and antioxidant properties in vivo and in vitro

    PubMed Central

    Tabet, Fatiha; Remaley, Alan T.; Segaliny, Aude I.; Millet, Jonathan; Yan, Ling; Nakhla, Shirley; Barter, Philip J.; Rye, Kerry-Anne; Lambert, Gilles

    2010-01-01

    Objectives The apolipoprotein (apo) A-I mimetic peptide 5A is highly specific for ABCA1-transporter mediated cholesterol efflux. We investigated whether the 5A peptide shares other beneficial features of apoA-I, such as protection against inflammation and oxidation. Methods New-Zealand White rabbits received an infusion of apoA-I, reconstituted HDL containing apoA-I ((A-I)rHDL) or the 5A peptide complexed with phospholipids (PLPC), prior to inserting a collar around the carotid artery. Human coronary artery endothelial cells (HCAECs) were incubated with (A-I)rHDL or 5A/PLPC prior to TNFa stimulation. Results ApoA-I, (A-I)rHDL and 5A/PLPC reduced the collar mediated increase in (i) endothelial expression of cell adhesion molecules VCAM-1 and ICAM-1, (ii) O2− production as well as the expression of the Nox4 catalytic subunits of the NADPH oxidase, and (iii) infiltration of circulating neutrophils into the carotid intima-media. In HCAECs, both 5A/PLPC and (A-I)rHDL inhibited TNFa induced ICAM-1 and VCAM-1 expression as well as the NF-κB signalling cascade and O2− production. The effects of the 5A/PLPC complex were no longer apparent in HCAECs knocked down for ABCA1. Conclusion Like apoA-I, the 5A peptide inhibits acute inflammation and oxidative stress in rabbit carotids and HCAECs. In vitro, the 5A peptide exerts these beneficial effects through interaction with ABCA1. PMID:19965776

  14. Apolipoprotein A-I: the dual face of a protein.

    PubMed

    Arciello, Angela; Piccoli, Renata; Monti, Daria Maria

    2016-12-01

    Conformational plasticity and flexibility are key structural features of ApoAI in lipid metabolism. Amyloidogenic single point mutations, associated with incurable familial amyloidosis with fibril deposition in peripheral organs, may have a dramatic impact on the structural and functional features of ApoAI. Here, the consistent body of data on ApoAI variants has been reviewed, with the aim of highlighting the hallmarks of the pathology. In accordance with our observations, as well as that of others, we propose a model that accounts for the alteration of the delicate balance between lipid-free/lipid-bound dynamic states which is based on monomer-to-dimer interconversion via domain swapping. © 2016 Federation of European Biochemical Societies.

  15. Apolipoprotein A-I mimetic peptide treatment inhibits inflammatory responses and improves survival in septic rats

    PubMed Central

    Zhang, Zhenghao; Datta, Geeta; Zhang, Yun; Miller, Andrew P.; Mochon, Paulina; Chen, Yiu-Fai; Chatham, John; Anantharamaiah, G. M.; White, C. Roger

    2009-01-01

    Systemic inflammation induces a multiple organ dysfunction syndrome that contributes to morbidity and mortality in septic patients. Since increasing plasma apolipoprotein A-I (apoA-I) and HDL may reduce the complications of sepsis, we tested the hypothesis that the apoA-I mimetic peptide 4F confers similar protective effects in rats undergoing cecal ligation and puncture (CLP) injury. Male Sprague-Dawley rats were randomized to undergo CLP or sham surgery. IL-6 levels were significantly elevated in plasma by 6 h after CLP surgery compared with shams. In subsequent studies, CLP rats were further subdivided to receive vehicle or 4F (10 mg/kg) by intraperitoneal injection, 6 h after sepsis induction. Sham-operated rats received saline. Echocardiographic studies showed a reduction in left ventricular end-diastolic volume, stroke volume, and cardiac output (CO) 24 h after CLP surgery. These changes were associated with reduced blood volume and left ventricular filling pressure. 4F treatment improved blood volume status, increased CO, and reduced plasma IL-6 in CLP rats. Total cholesterol (TC) and HDL were 79 ± 5 and 61 ± 4 mg/dl, respectively, in sham rats. TC was significantly reduced in CLP rats (54 ± 3 mg/dl) due to a reduction in HDL (26 ± 3 mg/dl). 4F administration to CLP rats attenuated the reduction in TC (69 ± 4 mg/dl) and HDL (41 ± 3 mg/dl) and prevented sepsis-induced changes in HDL protein composition. Increased plasma HDL in 4F-treated CLP rats was associated with an improvement in CO and reduced mortality. It is proposed that protective effects of 4F are related to its ability to prevent the sepsis-induced reduction in plasma HDL. PMID:19561306

  16. Niacin increases HDL biogenesis by enhancing DR4-dependent transcription of ABCA1 and lipidation of apolipoprotein A-I in HepG2 cells

    PubMed Central

    Zhang, Lin-Hua; Kamanna, Vaijinath S.; Ganji, Shobha H.; Xiong, Xi-Ming; Kashyap, Moti L.

    2012-01-01

    The lipidation of apoA-I in liver greatly influences HDL biogenesis and plasma HDL levels by stabilizing the secreted apoA-I. Niacin is the most effective lipid-regulating agent clinically available to raise HDL. This study was undertaken to identify regulatory mechanisms of niacin action in hepatic lipidation of apoA-I, a critical event involved in HDL biogenesis. In cultured human hepatocytes (HepG2), niacin increased: association of apoA-I with phospholipids and cholesterol by 46% and 23% respectively, formation of lipid-poor single apoA-I molecule-containing particles up to ∼ 2.4-fold, and pre β 1 and α migrating HDL particles. Niacin dose-dependently stimulated the cell efflux of phospholipid and cholesterol and increased transcription of ABCA1 gene and ABCA1 protein. Mutated DR4, a binding site for nuclear factor liver X receptor alpha (LXR α ) in the ABCA1 promoter, abolished niacin stimulatory effect. Further, knocking down LXR α or ABCA1 by RNA interference eliminated niacin-stimulated apoA-I lipidation. Niacin treatment did not change apoA-I gene expression. The present data indicate that niacin increases apoA-I lipidation by enhancing lipid efflux through a DR4-dependent transcription of ABCA1 gene in HepG2 cells. A stimulatory role of niacin in early hepatic formation of HDL particles suggests a new mechanism that contributes to niacin action to increase the stability of newly synthesized circulating HDL. PMID:22389325

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

    PubMed

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

    2015-08-01

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

  18. Apolipoprotein A-I mimetic peptide 4F blocks sphingomyelinase-induced LDL aggregation.

    PubMed

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

    2015-06-01

    Lipolytic modification of LDL particles by SMase generates LDL aggregates with a strong affinity for human arterial proteoglycans and may so enhance LDL retention in the arterial wall. Here, we evaluated the effects of apoA-I mimetic peptide 4F on structural and functional properties of the SMase-modified LDL particles. LDL particles with and without 4F were incubated with SMase, after which their aggregation, structure, and proteoglycan binding were analyzed. At a molar ratio of L-4F to apoB-100 of 2.5 to 20:1, 4F dose-dependently inhibited SMase-induced LDL aggregation. At a molar ratio of 20:1, SMase-induced aggregation was fully blocked. Binding of 4F to LDL particles inhibited SMase-induced hydrolysis of LDL by 10% and prevented SMase-induced LDL aggregation. In addition, the binding of the SMase-modified LDL particles to human aortic proteoglycans was dose-dependently inhibited by pretreating LDL with 4F. The 4F stabilized apoB-100 conformation and inhibited SMase-induced conformational changes of apoB-100. Molecular dynamic simulations showed that upon binding to protein-free LDL surface, 4F locally alters membrane order and fluidity and induces structural changes to the lipid layer. Collectively, 4F stabilizes LDL particles by preventing the SMase-induced conformational changes in apoB-100 and so blocks SMase-induced LDL aggregation and the resulting increase in LDL retention. Copyright © 2015 by the American Society for Biochemistry and Molecular Biology, Inc.

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

    PubMed

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

    2016-09-01

    Apolipoprotein A-I (apo A-I) amyloidosis is a non-AL, non-AA, and non-transthyretin type of amyloidosis associated with mutations in the APOA1 gene inherited in an autosomal dominant fashion. It is a form of systemic amyloidosis, but at presentation, can also mimic localized amyloidosis. The renal presentation generally involves interstitial and medullary deposition of apo A-I amyloid protein. We describe the identification of apo A-I amyloidosis by mass spectrometry in a 52-year old male, with no family history of amyloidosis, presenting with nephrotic syndrome and associated with heterozygosity for a novel APOA1 mutation (c.220 T > A) which encodes the known amyloidogenic Trp50Arg variant. Renal amyloid deposits in this case were confined to the glomeruli alone, and the patient developed progressive renal impairment. One year after diagnosis, the patient had a successful kidney transplant from an unrelated donor. Pathogenic mutations in the APOA1 gene are generally associated with symptoms of amyloidosis. In this family however, genotyping of family members identified several unaffected carriers suggesting a variable disease penetrance, which has not been described before in this form of amyloidosis and has implications when counselling those with APOA1 mutations. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  20. Featured Article: Alterations of lecithin cholesterol acyltransferase activity and apolipoprotein A-I functionality in human sickle blood

    PubMed Central

    Borja, Mark S; Borda, Mauricio; Larkin, Sandra K; Kuypers, Frans A

    2016-01-01

    In sickle cell disease (SCD) cholesterol metabolism appears dysfunctional as evidenced by abnormal plasma cholesterol content in a subpopulation of SCD patients. Specific activity of the high density lipoprotein (HDL)-bound lecithin cholesterol acyltransferase (LCAT) enzyme, which catalyzes esterification of cholesterol, and generates lysoPC (LPC) was significantly lower in sickle plasma compared to normal. Inhibitory amounts of LPC were present in sickle plasma, and the red blood cell (RBC) lysophosphatidylcholine acyltransferase (LPCAT), essential for the removal of LPC, displayed a broad range of activity. The functionality of sickle HDL appeared to be altered as evidenced by a decreased HDL–Apolipoprotein A-I exchange in sickle plasma as compared to control. Increased levels of oxidized proteins including ApoA-I were detected in sickle plasma. In vitro incubation of sickle plasma with washed erythrocytes affected the ApoA-I-exchange supporting the view that the RBC blood compartment can affect cholesterol metabolism in plasma. HDL functionality appeared to decrease during acute vaso-occlusive episodes in sickle patients and was associated with an increase of secretory PLA2, a marker for increased inflammation. Simvastatin treatment to improve the anti-inflammatory function of HDL did not ameliorate HDL–ApoA-I exchange in sickle patients. Thus, the cumulative effect of an inflammatory and highly oxidative environment in sickle blood contributes to a decrease in cholesterol esterification and HDL function, related to hypocholesterolemia in SCD. PMID:27354333

  1. Featured Article: Alterations of lecithin cholesterol acyltransferase activity and apolipoprotein A-I functionality in human sickle blood.

    PubMed

    Soupene, Eric; Borja, Mark S; Borda, Mauricio; Larkin, Sandra K; Kuypers, Frans A

    2016-11-01

    In sickle cell disease (SCD) cholesterol metabolism appears dysfunctional as evidenced by abnormal plasma cholesterol content in a subpopulation of SCD patients. Specific activity of the high density lipoprotein (HDL)-bound lecithin cholesterol acyltransferase (LCAT) enzyme, which catalyzes esterification of cholesterol, and generates lysoPC (LPC) was significantly lower in sickle plasma compared to normal. Inhibitory amounts of LPC were present in sickle plasma, and the red blood cell (RBC) lysophosphatidylcholine acyltransferase (LPCAT), essential for the removal of LPC, displayed a broad range of activity. The functionality of sickle HDL appeared to be altered as evidenced by a decreased HDL-Apolipoprotein A-I exchange in sickle plasma as compared to control. Increased levels of oxidized proteins including ApoA-I were detected in sickle plasma. In vitro incubation of sickle plasma with washed erythrocytes affected the ApoA-I-exchange supporting the view that the RBC blood compartment can affect cholesterol metabolism in plasma. HDL functionality appeared to decrease during acute vaso-occlusive episodes in sickle patients and was associated with an increase of secretory PLA2, a marker for increased inflammation. Simvastatin treatment to improve the anti-inflammatory function of HDL did not ameliorate HDL-ApoA-I exchange in sickle patients. Thus, the cumulative effect of an inflammatory and highly oxidative environment in sickle blood contributes to a decrease in cholesterol esterification and HDL function, related to hypocholesterolemia in SCD. © 2016 by the Society for Experimental Biology and Medicine.

  2. Interaction of thioflavin T with amyloid fibrils of apolipoprotein A-I N-terminal fragment: resonance energy transfer study.

    PubMed

    Girych, Mykhailo; Gorbenko, Galyna; Trusova, Valeriya; Adachi, Emi; Mizuguchi, Chiharu; Nagao, Kohjiro; Kawashima, Hiroyuki; Akaji, Kenichi; Lund-Katz, Sissel; Phillips, Michael C; Saito, Hiroyuki

    2014-01-01

    Apolipoprotein A-I is amenable to a number of specific mutations associated with hereditary systemic amyloidoses. Amyloidogenic properties of apoA-I are determined mainly by its N-terminal fragment. In the present study Förster resonance energy transfer between tryptophan as a donor and Thioflavin T as an acceptor was employed to obtain structural information on the amyloid fibrils formed by apoA-I variant 1-83/G26R/W@8. Analysis of the dye-fibril binding data provided evidence for the presence of two types of ThT binding sites with similar stoichiometries (bound dye to monomeric protein molar ratio ∼10), but different association constants (∼6 and 0.1μM(-1)) and ThT quantum yields in fibril-associated state (0.08 and 0.05, respectively). A β-strand-loop-β-strand structural model of 1-83/G26R/W@8 apoA-I fibrils has been proposed, with potential ThT binding sites located in the solvent-exposed grooves of the N-terminal β-sheet layer. Reasoning from the expanded FRET analysis allowing for heterogeneity of ThT binding centers and fibril polymorphism, the most probable locations of high- and low-affinity ThT binding sites were attributed to the grooves T16_Y18 and D20_L22, respectively.

  3. Serum opacity factor unmasks human plasma high-density lipoprotein instability via selective delipidation and apolipoprotein A-I desorption.

    PubMed

    Gillard, Baiba K; Courtney, Harry S; Massey, John B; Pownall, Henry J

    2007-11-13

    Human plasma high-density lipoproteins (HDL) are important vehicles in reverse cholesterol transport, the cardioprotective mechanism by which peripheral tissue-cholesterol is transported to the liver for disposal. HDL is the target of serum opacity factor (SOF), a substance produced by Streptococcus pyogenes that turns mammalian serum cloudy. Using a recombinant (r) SOF, we studied opacification and its mechanism. rSOF catalyzes the partial disproportionation of HDL into a cholesteryl ester-rich microemulsion (CERM) and a new HDL-like particle, neo HDL, with the concomitant release of lipid-free (LF)-apo A-I. Opacification is unique; rSOF transfers apo E and nearly all neutral lipids of approximately 100,000 HDL particles into a single large CERM whose size increases with HDL-CE content (r approximately 100-250 nm) leaving a neo HDL that is enriched in PL (41%) and protein (48%), especially apo A-II. rSOF is potent; within 30 min at 37 degrees C, 10 nM rSOF opacifies 4 microM HDL. At respective low and high physiological HDL concentrations, LF-apo A-I is monomeric and tetrameric. CERM formation and apo A-I release have similar kinetics suggesting parallel or rapid sequential steps. According to the reaction products and kinetics, rSOF is a heterodivalent fusogenic protein that uses a docking site to displace apo A-I and bind to exposed CE surfaces on HDL; the resulting rSOF-HDL complex recruits additional HDL with its binding-delipidation site and through multiple fusion steps forms a CERM. rSOF may be a clinically useful and novel modality for improving reverse cholesterol transport. With apo E and a high CE content, CERM could transfer large amounts of cholesterol to the liver for disposal via the LDL receptor; neo HDL is likely a better acceptor of cellular cholesterol than HDL; LF-apo A-I could enhance efflux via the ATP-binding casette transporter ABCA1.

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

    PubMed

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

    2013-10-01

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

  5. 22 CFR 224.39 - Appeal to A.I.D. Administrator.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Appeal to A.I.D. Administrator. 224.39 Section... CIVIL REMEDIES ACT § 224.39 Appeal to A.I.D. Administrator. (a) Any defendant who has filed a timely... appeal such decision to the A.I.D. Administrator by filing a notice of appeal with the A.I.D...

  6. 22 CFR 224.39 - Appeal to A.I.D. Administrator.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Appeal to A.I.D. Administrator. 224.39 Section... CIVIL REMEDIES ACT § 224.39 Appeal to A.I.D. Administrator. (a) Any defendant who has filed a timely... appeal such decision to the A.I.D. Administrator by filing a notice of appeal with the A.I.D...

  7. 22 CFR 224.39 - Appeal to A.I.D. Administrator.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 22 Foreign Relations 1 2012-04-01 2012-04-01 false Appeal to A.I.D. Administrator. 224.39 Section... CIVIL REMEDIES ACT § 224.39 Appeal to A.I.D. Administrator. (a) Any defendant who has filed a timely... appeal such decision to the A.I.D. Administrator by filing a notice of appeal with the A.I.D...

  8. 22 CFR 224.39 - Appeal to A.I.D. Administrator.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Appeal to A.I.D. Administrator. 224.39 Section... CIVIL REMEDIES ACT § 224.39 Appeal to A.I.D. Administrator. (a) Any defendant who has filed a timely... appeal such decision to the A.I.D. Administrator by filing a notice of appeal with the A.I.D...

  9. 22 CFR 224.39 - Appeal to A.I.D. Administrator.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Appeal to A.I.D. Administrator. 224.39 Section... CIVIL REMEDIES ACT § 224.39 Appeal to A.I.D. Administrator. (a) Any defendant who has filed a timely... appeal such decision to the A.I.D. Administrator by filing a notice of appeal with the A.I.D...

  10. Reagent or myeloperoxidase-generated hypochlorite affects discrete regions in lipid-free and lipid-associated human apolipoprotein A-I.

    PubMed Central

    Bergt, C; Oettl, K; Keller, W; Andreae, F; Leis, H J; Malle, E; Sattler, W

    2000-01-01

    We have previously shown that the modification of high-density lipoprotein subclass 3 (HDL(3)) by HOCl transformed an anti-atherogenic lipoprotein into a high-uptake form for macrophages and caused a significant impairment of cholesterol efflux capacity [Panzenboeck, Raitmayer, Reicher, Lindner, Glatter, Malle and Sattler (1997) J. Biol. Chem. 272, 29711-29720]. To elucidate the consequences of treatment with OCl(-) on distinct regions in apolipoprotein A-I (apo A-I), lipid-free and lipid-associated apo A-I were modified with increasing molar ratios of NaOCl or HOCl generated by the myeloperoxidase/H(2)O(2)/Cl(-) system. CD analysis revealed a pronounced decrease in alpha-helicity for lipid-free apo A-I modified by NaOCl, whereas lipid-associated apo A-I was less affected. The modification of apo A-I by NaOCl (molar oxidant-to-lipoprotein ratio 6:1) resulted in the formation of two distinct oxidized forms of apo A-I with molecular masses 32 or 48 atomic mass units (a.m.u.) higher than that of native apo A-I, indicating the addition of two or three oxygen atoms to the native protein. HPLC analysis of tryptic digests obtained from lipid-free and lipid-associated apo A-I modified with increasing oxidant-to-apolipoprotein molar ratios revealed a concentration-dependent modification of apo A-I: at a low molar oxidant-to-lipoprotein ratio (5:1) the peaks corresponding to the methionine-containing tryptic peptides T11 (residues 84-88), T16 (residues 108-116) and T22 (residues 141-149), located in the central region of apo A-I, disappeared. Their loss was accompanied by the formation of three oxidation products with a molecular mass 16 a.m.u. higher than that of the native peptides. This indicates the addition of oxygen, most probably caused by the oxidation of Met(86), Met(112) and Met(148) to the corresponding methionine sulphoxides. At a molar NaOCl-to-apo A-I ratio of 10:1 the disappearance of peptides T1 (residues 1-10), T7 (residues 46-59) and T9 (residues 62-77) was

  11. Homocysteine diminishes apolipoprotein A-I function and expression in patients with hypothyroidism: a cross-sectional study.

    PubMed

    Yang, Ning; Yao, Zhi; Miao, Li; Liu, Jia; Gao, Xia; Xu, Yuan; Wang, Guang

    2016-07-26

    Hypothyroidism (HO) can significantly impair lipid metabolism and increase cardiovascular disease risk. Hyperhomocysteinemia (HHcy) is an independent risk factor for cardiovascular disease. Our previous study demonstrated that HHcy significantly induced insulin resistance and impaired coronary artery endothelial function in patients with either hypertension or HO. In the present study, we studied whether plasma levels of high-density lipoprotein-cholesterol (HDL-C) and apolipoprotein A-I (Apo A-I) were altered in patients with HO, and if so, whether this change was mediated by HHcy. A total of 258 subjects were enrolled and divided into the following three groups: control group (n = 94), HO group (n = 73), and subclinical hypothyroidism (SHO) group (n = 91). Additionally, all groups were subdivided based on the subjects' Hcy levels into HHcy (plasma Hcy level over 15 μmol/l) and normal Hcy subgroups. The plasma levels of lipid indexes were measured. Statistical analyses were performed to evaluate the correlations between groups. The plasma Hcy levels were significantly higher in the HO group than in the SHO or control groups (all p < 0.05). Moreover, levels of Apo A-I and HDL-C were markedly reduced in the HHcy subgroup compared with the normal Hcy subgroup for patients with either HO (Apo A-I: p < 0.05; HDL-C: p < 0.01) or SHO (Apo A-I: p < 0.05; HDL-C: p < 0.01). In addition, the plasma Hcy levels were negatively correlated with levels of Apo A-I in all three groups (HO group: r = - 0.320, SHO group: r = - 0.337 and control group: r = - 0.317; all p < 0.01). Hcy levels were significantly increased in patients with HO or SHO. These increased Hcy levels may impair cardiovascular function via the inhibition of Apo A-1 expression and impairment of its antioxidant capacity. Our findings provide new insights into the pathogenesis of hypothyroidism-induced metabolic disorders.

  12. Safety and Tolerability of CSL112, a Reconstituted, Infusible, Plasma-Derived Apolipoprotein A-I, After Acute Myocardial Infarction

    PubMed Central

    Korjian, Serge; Tricoci, Pierluigi; Daaboul, Yazan; Yee, Megan; Jain, Purva; Alexander, John H.; Steg, P. Gabriel; Lincoff, A. Michael; Kastelein, John J.P.; Mehran, Roxana; D’Andrea, Denise M.; Deckelbaum, Lawrence I.; Merkely, Bela; Zarebinski, Maciej; Ophuis, Ton Oude; Harrington, Robert A.

    2016-01-01

    Background: Human or recombinant apolipoprotein A-I (apoA-I) has been shown to increase high-density lipoprotein–mediated cholesterol efflux capacity and to regress atherosclerotic disease in animal and clinical studies. CSL112 is an infusible, plasma-derived apoA-I that has been studied in normal subjects or those with stable coronary artery disease. This study aimed to characterize the safety, tolerability, pharmacokinetics, and pharmacodynamics of CSL112 in patients with a recent acute myocardial infarction. Methods: The AEGIS-I trial (Apo-I Event Reducing in Ischemic Syndromes I) was a multicenter, randomized, double-blind, placebo-controlled, dose-ranging phase 2b trial. Patients with myocardial infarction were stratified by renal function and randomized 1:1:1 to CSL112 (2 g apoA-I per dose) and high-dose CSL112 (6 g apoA-I per dose), or placebo for 4 consecutive weekly infusions. Coprimary safety end points were occurrence of either a hepatic safety event (an increase in alanine transaminase >3 times the upper limit of normal or an increase in total bilirubin >2 times the upper limit of normal) or a renal safety event (an increase in serum creatinine >1.5 times the baseline value or a new requirement for renal replacement therapy). Results: A total of 1258 patients were randomized, and 91.2% received all 4 infusions. The difference in incidence rates for an increase in alanine transaminase or total bilirubin between both CSL112 arms and placebo was within the protocol-defined noninferiority margin of 4%. Similarly, the difference in incidence rates for an increase in serum creatinine or a new requirement for renal replacement therapy was within the protocol-defined noninferiority margin of 5%. CSL112 was associated with increases in apoA-I and ex vivo cholesterol efflux similar to that achieved in patients with stable coronary artery disease. In regard to the secondary efficacy end point, the risk for the composite of major adverse cardiovascular events

  13. 22 CFR 214.22 - Responsibilities within A.I.D.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Responsibilities within A.I.D. 214.22 Section... Termination and Renewal of Advisory Committees § 214.22 Responsibilities within A.I.D. Responsibilities within A.I.D. for the renewal of advisory committees are as follows: (a) The Office or Bureau through which...

  14. 22 CFR 214.22 - Responsibilities within A.I.D.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Responsibilities within A.I.D. 214.22 Section... Termination and Renewal of Advisory Committees § 214.22 Responsibilities within A.I.D. Responsibilities within A.I.D. for the renewal of advisory committees are as follows: (a) The Office or Bureau through which...

  15. 22 CFR 214.22 - Responsibilities within A.I.D.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Responsibilities within A.I.D. 214.22 Section... Termination and Renewal of Advisory Committees § 214.22 Responsibilities within A.I.D. Responsibilities within A.I.D. for the renewal of advisory committees are as follows: (a) The Office or Bureau through which...

  16. 22 CFR 214.22 - Responsibilities within A.I.D.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Responsibilities within A.I.D. 214.22 Section... Termination and Renewal of Advisory Committees § 214.22 Responsibilities within A.I.D. Responsibilities within A.I.D. for the renewal of advisory committees are as follows: (a) The Office or Bureau through which...

  17. 22 CFR 214.22 - Responsibilities within A.I.D.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 22 Foreign Relations 1 2012-04-01 2012-04-01 false Responsibilities within A.I.D. 214.22 Section... Termination and Renewal of Advisory Committees § 214.22 Responsibilities within A.I.D. Responsibilities within A.I.D. for the renewal of advisory committees are as follows: (a) The Office or Bureau through which...

  18. 22 CFR 221.24 - Subrogation of A.I.D.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 22 Foreign Relations 1 2012-04-01 2012-04-01 false Subrogation of A.I.D. 221.24 Section 221.24 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT ISRAEL LOAN GUARANTEE STANDARD TERMS AND CONDITIONS Procedure for Obtaining Compensation § 221.24 Subrogation of A.I.D. In the event of payment by A.I.D. to...

  19. 22 CFR 221.24 - Subrogation of A.I.D.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Subrogation of A.I.D. 221.24 Section 221.24 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT ISRAEL LOAN GUARANTEE STANDARD TERMS AND CONDITIONS Procedure for Obtaining Compensation § 221.24 Subrogation of A.I.D. In the event of payment by A.I.D. to...

  20. 22 CFR 221.24 - Subrogation of A.I.D.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Subrogation of A.I.D. 221.24 Section 221.24 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT ISRAEL LOAN GUARANTEE STANDARD TERMS AND CONDITIONS Procedure for Obtaining Compensation § 221.24 Subrogation of A.I.D. In the event of payment by A.I.D. to...

  1. 22 CFR 221.24 - Subrogation of A.I.D.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Subrogation of A.I.D. 221.24 Section 221.24 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT ISRAEL LOAN GUARANTEE STANDARD TERMS AND CONDITIONS Procedure for Obtaining Compensation § 221.24 Subrogation of A.I.D. In the event of payment by A.I.D. to...

  2. 22 CFR 221.24 - Subrogation of A.I.D.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Subrogation of A.I.D. 221.24 Section 221.24 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT ISRAEL LOAN GUARANTEE STANDARD TERMS AND CONDITIONS Procedure for Obtaining Compensation § 221.24 Subrogation of A.I.D. In the event of payment by A.I.D. to...

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

    PubMed

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

    2016-08-01

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

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

    PubMed Central

    2013-01-01

    Background 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 metabolic syndrome (MetS). Methods Twenty-six men with MetS (NCEP-ATP III) were recruited from the general community. In this fixed sequence study, participants’ diet was first standardized to a control diet reflecting current averages in macronutrient intake in North American men, with all foods and beverages provided under isoenergetic conditions for 5 weeks. Participants were then fed an isoenergetic MedDiet over a subsequent period of 5 weeks to maintain their weight constant. During the last week of each diet, participants received a single bolus dose of [5,5,5-2H3] L-leucine and fasting blood samples were collected at predetermined time points. ApoA-I kinetic was determined by multicompartmental modeling using isotopic enrichment data over time. Data were analyses using MIXED models. Results The response of HDL-cholesterol (C) to MedDiet was heterogeneous, such that there was no mean change compared with the control diet. Plasma apoA-I concentration (−3.9%) and pool size (−5.3%, both P < 0.05) were significantly lower after MedDiet and apoA-I production rate tended to be reduced (−5.7%, P = 0.07) with no change in apoA-I fractional catabolic rate (FCR, -1.6%, P = 0.64). Participants among whom HDL-C concentrations were increased with MedDiet (responders: mean ∆HDL-C: +9.9 ± 3.2%, N = 11) showed significantly greater reductions in apoA-I FCR and in apoB and very-low-density lipoprotein-triglycerides (VLDL-TG) concentrations (all P < 0.04) than those among whom HDL-C levels were reduced after the MedDiet (non-responders: mean ∆HDL-C: -12.0 ± 3.9%, N = 8). Correlation analysis revealed that only variations in apoA-I

  5. Serum amyloid A protein forms a complex with a fragment of apolipoprotein A-I in the domestic blue fox: a protective mechanism against AA amyloidosis?

    PubMed

    Elisen, Ellen Johanne; Bruun, Cathrine Foyn; Nordstoga, Knut; Husby, Gunnar; Sletten, Knut

    2004-09-01

    The spontaneous occurrence of protein AA-type of amyloidosis varies among animal species. As reactive AA-type of amyloidosis has never been detected in the blue fox, we obtained acute phase sera to search for amyloid-protective elements. The purified SAA fraction was characterized by mass and sequence analyses to disclose any unique domains in the amino acid sequence. The data revealed an SAA protein with heterogeneities in several positions, and showed the typical insertion between positions 69 and 70. By comparing the amino acid sequence with that from other mammals, no unique sequence could be observed. However, a C-terminal fragment of apolipoprotein A-I (ApoA-I) was found attached to the SAA. The amino acid sequence of the ApoA-I fragment revealed a partially blocked and ragged N-terminus. A comparison of the amino acid sequence of ApoA-I with that from the dog showed that the ApoA-I fragment started about position 190, had an intact C-terminus, and showed an identical sequence in all positions, except one. Based on the data, we suggest an interaction of the C-terminal fragment of ApoA-I with the SAA protein that inhibits the AA fibrillogenesis in the blue fox.

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

    PubMed

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

    2015-05-01

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

  7. Novel pathways of apolipoprotein A-I metabolism in HDL of different sizes in humans

    PubMed Central

    Mendivil, Carlos O.; Furtado, Jeremy; Morton, Allyson M.; Wang, Liyun; Sacks, Frank M.

    2015-01-01

    Objective A prevailing concept is that HDL is secreted into the systemic circulation as a small mainly discoidal particle; which expands progressively and becomes spherical by uptake and esterification of cellular cholesterol; and then contracts by cholesterol ester delivery to the liver, a process known as reverse cholesterol transport, thought to be impaired in people with low HDL cholesterol (HDLc). This metabolic framework has not been established in humans. Approach and results We studied the metabolism of apolipoproteinA-I in four standard HDL sizes by endogenous isotopic labeling in six overweight adults with low HDLc and in six adults with normal body weight with high plasma HDLc. Contrary to expectation, HDL was secreted into the circulation in its entire size distribution from very small to very large, similarly in both groups. Very small (prebeta) HDL comprised only 8% of total apoA-I secretion. Each HDL subfraction circulated mostly within its secreted size range for 1–4 days, and then was cleared. Enlargement of very small and medium to large and very large HDL, and generation of very small from medium HDL were minor metabolic pathways. Prebeta HDL was cleared slower whereas medium, large and very large HDL were cleared faster in the low HDLc group. Conclusions A new model is proposed from these results in which HDL is metabolized in plasma mainly within several discrete, stable sizes, across the common range of HDLc concentrations. PMID:26543096

  8. Tubulointerstitial nephritis is a dominant feature of hereditary apolipoprotein A-I amyloidosis.

    PubMed

    Gregorini, Gina; Izzi, Claudia; Ravani, Pietro; Obici, Laura; Dallera, Nadia; Del Barba, Andrea; Negrinelli, Alessandro; Tardanico, Regina; Nardi, Matilde; Biasi, Luciano; Scalvini, Tiziano; Merlini, Giampaolo; Scolari, Francesco

    2015-06-01

    Apolipoprotein A-I is the main protein of high-density lipoprotein particles, and is encoded by the APOA1 gene. Several APOA1 mutations have been found, either affecting the lecithin:cholesterol acyltransferase activity, determining familial HDL deficiency, or resulting in amyloid formation with prevalent deposits in the kidney and liver. Evaluation of familial tubulointerstitial nephritis in patients with the Leu75Pro APOA-I amyloidosis mutation resulted in the identification of 253 carriers belonging to 50 families from Brescia, Italy. A total of 219 mutation carriers underwent clinical, laboratory, and instrumental tests. Of these, 62% had renal, hepatic, and testicular disease; 38% were asymptomatic. The disease showed an age-dependent penetrance. Tubulointerstitial nephritis was diagnosed in 49% of the carriers, 13% of whom progressed to kidney failure requiring dialysis. Hepatic involvement with elevation of cholestasis indices was diagnosed in 30% of the carriers, 38% of whom developed portal hypertension. Impaired spermatogenesis and hypogonadism was found in 68% of male carriers. The cholesterol levels were lower than normal in 80% of the mutation carriers. Thus, tubulointerstitial nephritis was highly prevalent in this large series of patients with Leu75Pro apoA-I amyloidosis. Persistent elevation of alkaline phosphatase, reduced HDL cholesterol plasma levels, and hypogonadism in men are key diagnostic features of this form of amyloidosis.

  9. C/EBP-β Is Differentially Affected by PPARα Agonists Fenofibric Acid and GW7647, But Does Not Change Apolipoprotein A-I Production During ER-Stress and Inflammation.

    PubMed

    van der Krieken, Sophie E; Popeijus, Herman E; Konings, Maurice; Dullens, Stefan P J; Mensink, Ronald P; Plat, Jogchum

    2017-04-01

    Increasing apolipoproteinA-I (apoA-I) production may be anti-atherogenic. Thus, there is a need to identify regulatory factors involved. Transcription of apoA-I involves peroxisome-proliferator-activated-receptor-alpha (PPARα) activation, but endoplasmic reticulum (ER) -stress and inflammation also influence apoA-I production. To unravel why PPARα agonist GW7647 increased apoA-I production compared to PPARα agonist fenofibric acid (FeAc) in human hepatocellular carcinoma (HepG2) and colorectal adenocarcinoma (CaCo-2) cells, gene expression profiles were compared. Microarray analyses suggested CCAAT/enhancer-binding-protein-beta (C/EBP-β) involvement in the FeAc condition. Therefore, C/EBP-β silencing and isoform-specific overexpression experiments were performed under ER-stressed, inflammatory and non-inflammatory conditions. mRNA expression of C/EBP-β, ATF3, NF-IL3 and GDF15 were upregulated by FeAc compared to GW7647 in both cell lines, while DDIT3 and DDIT4 mRNA were only upregulated in HepG2 cells. This ER-stress related signature was associated with decreased apoA-I secretion. After ER-stress induction by thapsigargin or FeAc addition, intracellular apoA-I concentrations decreased, while ER-stress marker expression (CHOP, XBP1s, C/EBP-β) increased. Cytokine addition increased intracellular C/EBP-β levels and lowered apoA-I concentrations. Although a C/EBP binding place is present in the apoA-I promoter, C/EBP-β silencing or isoform-specific overexpression did not affect apoA-I production in inflammatory, non-inflammatory and ER-stressed conditions. Therefore, C/EBP-β is not a target to influence hepatic apoA-I production. J. Cell. Biochem. 118: 754-763, 2017. © 2016 Wiley Periodicals, Inc.

  10. Apolipoprotein A-I gene transfer exerts immunomodulatory effects and reduces vascular inflammation and fibrosis in ob/ob mice.

    PubMed

    Spillmann, Frank; De Geest, Bart; Muthuramu, Ilayaraja; Amin, Ruhul; Miteva, Kapka; Pieske, Burkert; Tschöpe, Carsten; Van Linthout, Sophie

    2016-01-01

    Obesity is associated with vascular inflammation, fibrosis and reduced high-density lipoproteins (HDL)-cholesterol. We aimed to investigate whether adenoviral gene transfer with human apolipoprotein (apo) A-I (Ad.A-I), the main apo of HDL, could exert immunomodulatory effects and counteract vascular inflammation and fibrosis in ob/ob mice. Ad.A-I transfer was performed in 8 weeks (w) old ob/ob mice, which were sacrificed 7 w later. The aorta was excised for mRNA analysis and the spleen for splenocyte isolation for subsequent flow cytometry and co-culture with murine fibroblasts. HDL was added to mononuclear cells (MNC) and fibroblasts to assess their impact on adhesion capacity and collagen deposition, respectively. Ad.A-I led to a 1.8-fold (p < 0.05) increase in HDL-cholesterol versus control ob/ob mice at the day of sacrifice, which was paralleled by a decrease in aortic TNF-α and VCAM-1 mRNA expression. Pre-culture of MNC with HDL decreased their adhesion to TNF-α-activated HAEC. Ad.A-I exerted immunomodulatory effects as evidenced by a downregulation of aortic NOD2 and NLRP3 mRNA expression and by a 12 %, 6.9 %, and 15 % decrease of the induced proliferation/activity of total splenic MNC, CD4+, and CD8+ cells in ob/ob Ad.A-I versus control ob/ob mice, respectively (p < 0.05). Ad.A-I further reduced aortic collagen I and III mRNA expression by 62 % and 66 %, respectively (p < 0.0005), and abrogated the potential of ob/ob splenocytes to induce the collagen content in murine fibroblasts upon co-culture. Finally, HDL decreased the TGF-ß1-induced collagen deposition of murine fibroblasts in vitro. Apo A-I transfer counteracts vascular inflammation and fibrosis in ob/ob mice.

  11. Diabetic foot disease: grading inflammation by apolipoprotein A-I, C-reactive protein and serum amyloid A.

    PubMed

    Wang, Weiling; Zhang, Yan; Liao, Yonggan; Wu, Jun; Zhou, Lixia; Tang, Yijun; Cao, Yang; Metzmann, Erwin; Wang, Rongfang

    2014-01-01

    The different grading systems for diabetic foot disease pose a challenge in clinical decision making because each system fails to accurately reflect the individual course of disease progression. This study attempts to identify laboratory measurements for classifying diabetic foot disease to guide clinical treatment. The sera of 111 clinically graded diabetic foot patients were measured for several laboratory parameters including serum amyloid A (SAA), C-reactive protein (CRP), and apo A-I. By using the molar sum of CRP and SAA and then dividing by the molarity of apo A-I, an acute phase index was introduced to assess the inflammatory status of the patients. Based on a newly defined acute phase index (API), diabetic foot patients were classified into 3 distinct groups that provide a diagnostic tool complementing the established Texas grading system for clinical decision making. The integration of the serum concentrations of SAA, CRP and apo A-I into an acute phase index (API) offers an opportunity to triage diabetic foot patients who may benefit from personalized medicine.

  12. [Association between peroxisome proliferator-activated receptor and gene-gene interactions with the apolipoprotein A I/apolipoprotein B100 ratio].

    PubMed

    Hai, Bo; Ni, Chuanmin; Xie, Huijian; Guo, Zhirong; Wu, Ming; Chen, Qiu; Zhou, Zhengyuan; Fan, Wei; Zhou, Hui

    2015-04-01

    To investigate the association between ten single nucleotide polymorphisms (SNPs) in the peroxisome proliferator-activated receptors (PPARα, β, γ) with apolipoprotein A I/apolipoprotein B100 (ApoA I/ApoB100) ratio and the additional role of a gene-gene interactions among the 10 SNPs. Participants were recruited under the framework of the Prevention of Multiple Metabolic Disorders and Metabolic Syndrome in Jiangsu Province (PMMJS) cohort population survey in the urban community of Jiangsu province of China.A total of 630 subjects were randomly selected and no individual was related.Ten SNPs (rs135539, rs4253778, rs1800206, rs2016520, rs9794, rs10865710, rs1805192, rs709158, rs3856806 and rs4684847) were selected from the HapMap database,which covered PPARα, PPARβ and PPARγ. A linear regression model was used to analyze the relations between ten SNPs in the PPARs and ApoA I/ApoB100 ratio level. Mean difference and 95% CI were calculated. Interactions were explored by using the method of Generalized Multifactor Dimensionality Reduction (GMDR). After adjusting for age, gender, smoking status, alcohol consumption, occupational physical activity, high-fat diet as well as low-fiber diet, both rs1800206 and rs3856806 were significantly associated with a decreased level of ApoA I/ApoB100 ratio, mean difference (95% CI) values were -1.19 (-1.88 to -0.50) and -0.77 (-1.40 to -0.14). Whereas rs4253778 was significantly associated with an increased level of ApoA I/ApoB100 ratio, Mean difference (95% CI) values was 0.80 (0.08 to 1.52). GMDR analysis showed a significant gene-gene interaction among rs4253778, rs1800206 of PPARα, rs9794, rs2016520 of PPARβ and rs10865710, rs3856806, rs709158, rs1805192 of PPARγ for eight-dimension models (P = 0.01), in which prediction accuracy was 0.624 and cross-validation consistency was 7/10. The rs1800206 of PPARα and rs3856806 of PPARγ are significantly associated with a decreased level of ApoA I/ApoB100 ratio while rs4253778 of

  13. Lower HDL-C and apolipoprotein A-I are related to higher glomerular filtration rate in subjects without kidney disease[S

    PubMed Central

    Krikken, Jan A.; Gansevoort, Ron T.; Dullaart, Robin P. F.

    2010-01-01

    Animal experiments show that the kidney contributes to apolipoprotein (apo)A-I catabolism. We tested relationships of HDL cholesterol (HDL-C) and apo-I with kidney function in subjects without severe chronic kidney disease. Included was a random sample of the general population (part of the PREVEND cohort). Kidney function [estimated glomerular filtration rate (e-GFR) by two well-established equations and creatinine clearance], HDL-C, triglycerides, apoA-I and insulin resistance (HOMAir) were measured in 2,484 fasting subjects (e-GFR≥45 ml/min/1.73m2) without macroalbuminuria, cardiovascular disease, diabetes, or the use of anti-hypertensives and/or lipid-lowering agents. HDL-C (r = −0.056 to −0.102, P < 0.01 to < 0.001) and apo A-I (r = −0.096 to −0.126, P < 0.001) were correlated inversely with both GFR estimates and creatinine clearance in univariate analyses. Multiple linear regression analyses also demonstrated inverse relationships of HDL-C and apoA-I with all measures of kidney function even after adjustment for age, sex, waist circumference, HOMAir, triglycerides, and urinary albumin excretion (P = 0.053 to 0.004). In conclusion, HDL-C and apoA-I are inversely related to e-GFR and creatinine clearance in subjects without severely compromised kidney function, which fits the concept that the kidney contributes to apoA-I regulation in humans. High glomerular filtration rate may be an independent determinant of a pro-atherogenic lipoprotein profile. PMID:20211930

  14. 22 CFR 204.22 - Right of A.I.D. to cure default.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Right of A.I.D. to cure default. 204.22 Section... CONDITIONS Procedure for Obtaining Compensation § 204.22 Right of A.I.D. to cure default. Within sixty (60) days after the Date of Application for Compensation, A.I.D. may at any time make payments to the Lender...

  15. 22 CFR 204.22 - Right of A.I.D. to cure default.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Right of A.I.D. to cure default. 204.22 Section... CONDITIONS Procedure for Obtaining Compensation § 204.22 Right of A.I.D. to cure default. Within sixty (60) days after the Date of Application for Compensation, A.I.D. may at any time make payments to the Lender...

  16. 22 CFR 204.22 - Right of A.I.D. to cure default.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Right of A.I.D. to cure default. 204.22 Section... CONDITIONS Procedure for Obtaining Compensation § 204.22 Right of A.I.D. to cure default. Within sixty (60) days after the Date of Application for Compensation, A.I.D. may at any time make payments to the Lender...

  17. 22 CFR 204.22 - Right of A.I.D. to cure default.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 22 Foreign Relations 1 2012-04-01 2012-04-01 false Right of A.I.D. to cure default. 204.22 Section... CONDITIONS Procedure for Obtaining Compensation § 204.22 Right of A.I.D. to cure default. Within sixty (60) days after the Date of Application for Compensation, A.I.D. may at any time make payments to the Lender...

  18. 22 CFR 204.22 - Right of A.I.D. to cure default.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Right of A.I.D. to cure default. 204.22 Section... CONDITIONS Procedure for Obtaining Compensation § 204.22 Right of A.I.D. to cure default. Within sixty (60) days after the Date of Application for Compensation, A.I.D. may at any time make payments to the Lender...

  19. Cholesteryl Ester Transfer Protein Inhibition With Anacetrapib Decreases Fractional Clearance Rates of High-Density Lipoprotein Apolipoprotein A-I and Plasma Cholesteryl Ester Transfer Protein.

    PubMed

    Reyes-Soffer, Gissette; Millar, John S; Ngai, Colleen; Jumes, Patricia; Coromilas, Ellie; Asztalos, Bela; Johnson-Levonas, Amy O; Wagner, John A; Donovan, Daniel S; Karmally, Wahida; Ramakrishnan, Rajasekhar; Holleran, Stephen; Thomas, Tiffany; Dunbar, Richard L; deGoma, Emil M; Rafeek, Hashmi; Baer, Amanda L; Liu, Yang; Lassman, Michael E; Gutstein, David E; Rader, Daniel J; Ginsberg, Henry N

    2016-05-01

    Anacetrapib (ANA), an inhibitor of cholesteryl ester transfer protein (CETP) activity, increases plasma concentrations of high-density lipoprotein cholesterol (HDL-C), apolipoprotein A-I (apoA)-I, apoA-II, and CETP. The mechanisms responsible for these treatment-related increases in apolipoproteins and plasma CETP are unknown. We performed a randomized, placebo (PBO)-controlled, double-blind, fixed-sequence study to examine the effects of ANA on the metabolism of HDL apoA-I and apoA-II and plasma CETP. Twenty-nine participants received atorvastatin (ATV) 20 mg/d plus PBO for 4 weeks, followed by ATV plus ANA 100 mg/d for 8 weeks (ATV-ANA). Ten participants received double PBO for 4 weeks followed by PBO plus ANA for 8 weeks (PBO-ANA). At the end of each treatment, we examined the kinetics of HDL apoA-I, HDL apoA-II, and plasma CETP after D3-leucine administration as well as 2D gel analysis of HDL subspecies. In the combined ATV-ANA and PBO-ANA groups, ANA treatment increased plasma HDL-C (63.0%; P<0.001) and apoA-I levels (29.5%; P<0.001). These increases were associated with reductions in HDL apoA-I fractional clearance rate (18.2%; P=0.002) without changes in production rate. Although the apoA-II levels increased by 12.6% (P<0.001), we could not discern significant changes in either apoA-II fractional clearance rate or production rate. CETP levels increased 102% (P<0.001) on ANA because of a significant reduction in the fractional clearance rate of CETP (57.6%, P<0.001) with no change in CETP production rate. ANA treatment increases HDL apoA-I and CETP levels by decreasing the fractional clearance rate of each protein. © 2016 American Heart Association, Inc.

  20. Myeloperoxidase-mediated oxidation targets serum apolipoprotein A-I in diabetic patients and represents a potential mechanism leading to impaired anti-apoptotic activity of high density lipoprotein.

    PubMed

    Lu, Naihao; Xie, Shiliang; Li, Jiayu; Tian, Rong; Peng, Yi-Yuan

    2015-02-20

    It is demonstrated that levels of protein-bound chlorotyrosine, nitrotyrosine and myeloperoxidase (MPO), a protein that catalyzes generation of chlorinating and nitrating oxidants, serve as independent predictors of cardiovascular disease. Immunoprecipitation and Western blot were used to analyze protein concentration, nitration and chlorination. LC-MS/MS was used to identify nitrated and chlorinated sites of Tyr from immunoprecipitated serum proteins. Apolipoprotein A-I (apoA-I), the primary protein constituent of high density lipoprotein (HDL), was identified as a selective target for MPO-catalyzed nitration and chlorination in patients with type 2 diabetes. The serum proteins from diabetic subjects showed that the levels of apoA-I nitration and chlorination were clearly increased, whereas apoA-I concentration and cholesterol efflux activity were significantly decreased. MPO as a likely mechanism for oxidative modification of apoA-I in vivo was apparently facilitated by MPO binding to apoA-I. Subsequently, it was found that Tyr 192 was the major nitration and chlorination site in apoA-I from diabetic serum. Further studies in vitro revealed that besides the classic inhibition in cholesterol efflux activities, MPO-catalyzed oxidation could result in a loss of anti-apoptotic activity of lipoprotein. ApoA-I undergoes MPO-mediated oxidation in serum from diabetic patients compared to non-diabetic subjects and MPO-catalyzed modification may impair the anti-apoptotic properties of HDL in vitro. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Quantification of serum apolipoproteins A-I and B-100 in clinical samples using an automated SISCAPA-MALDI-TOF-MS workflow.

    PubMed

    van den Broek, Irene; Nouta, Jan; Razavi, Morteza; Yip, Richard; Bladergroen, Marco R; Romijn, Fred P H T M; Smit, Nico P M; Drews, Oliver; Paape, Rainer; Suckau, Detlev; Deelder, André M; van der Burgt, Yuri E M; Pearson, Terry W; Anderson, N Leigh; Cobbaert, Christa M

    2015-06-15

    A fully automated workflow was developed and validated for simultaneous quantification of the cardiovascular disease risk markers apolipoproteins A-I (apoA-I) and B-100 (apoB-100) in clinical sera. By coupling of stable-isotope standards and capture by anti-peptide antibodies (SISCAPA) for enrichment of proteotypic peptides from serum digests to matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) MS detection, the standardized platform enabled rapid, liquid chromatography-free quantification at a relatively high throughput of 96 samples in 12h. The average imprecision in normo- and triglyceridemic serum pools was 3.8% for apoA-I and 4.2% for apoB-100 (4 replicates over 5 days). If stored properly, the MALDI target containing enriched apoA-1 and apoB-100 peptides could be re-analyzed without any effect on bias or imprecision for at least 7 days after initial analysis. Validation of the workflow revealed excellent linearity for daily calibration with external, serum-based calibrators (R(2) of 0.984 for apoA-I and 0.976 for apoB-100 as average over five days), and absence of matrix effects or interference from triglycerides, protein content, hemolysates, or bilirubins. Quantification of apoA-I in 93 normo- and hypertriglyceridemic clinical sera showed good agreement with immunoturbidimetric analysis (slope = 1.01, R(2) = 0.95, mean bias = 4.0%). Measurement of apoB-100 in the same clinical sera using both methods, however, revealed several outliers in SISCAPA-MALDI-TOF-MS measurements, possibly as a result of the lower MALDI-TOF-MS signal intensity (slope = 1.09, R(2) = 0.91, mean bias = 2.0%). The combination of analytical performance, rapid cycle time and automation potential validate the SISCAPA-MALDI-TOF-MS platform as a valuable approach for standardized and high-throughput quantification of apoA-I and apoB-100 in large sample cohorts. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. 22 CFR 214.3 - A.I.D. Advisory Committee Management Officer.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 22 Foreign Relations 1 2013-04-01 2013-04-01 false A.I.D. Advisory Committee Management Officer. 214.3 Section 214.3 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT ADVISORY COMMITTEE MANAGEMENT General § 214.3 A.I.D. Advisory Committee Management Officer. The Advisory Committee Management...

  3. 22 CFR 214.3 - A.I.D. Advisory Committee Management Officer.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 1 2014-04-01 2014-04-01 false A.I.D. Advisory Committee Management Officer. 214.3 Section 214.3 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT ADVISORY COMMITTEE MANAGEMENT General § 214.3 A.I.D. Advisory Committee Management Officer. The Advisory Committee Management...

  4. 22 CFR 214.3 - A.I.D. Advisory Committee Management Officer.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 22 Foreign Relations 1 2012-04-01 2012-04-01 false A.I.D. Advisory Committee Management Officer. 214.3 Section 214.3 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT ADVISORY COMMITTEE MANAGEMENT General § 214.3 A.I.D. Advisory Committee Management Officer. The Advisory Committee Management...

  5. 22 CFR 214.3 - A.I.D. Advisory Committee Management Officer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false A.I.D. Advisory Committee Management Officer. 214.3 Section 214.3 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT ADVISORY COMMITTEE MANAGEMENT General § 214.3 A.I.D. Advisory Committee Management Officer. The Advisory Committee Management...

  6. 22 CFR 214.3 - A.I.D. Advisory Committee Management Officer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 1 2011-04-01 2011-04-01 false A.I.D. Advisory Committee Management Officer. 214.3 Section 214.3 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT ADVISORY COMMITTEE MANAGEMENT General § 214.3 A.I.D. Advisory Committee Management Officer. The Advisory Committee Management...

  7. 22 CFR 204.33 - A.I.D. approval of acceleration of notes.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 1 2014-04-01 2014-04-01 false A.I.D. approval of acceleration of notes. 204.33 Section 204.33 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT HOUSING GUARANTY STANDARD TERMS AND CONDITIONS Covenants § 204.33 A.I.D. approval of acceleration of notes. Without the...

  8. 22 CFR 204.33 - A.I.D. approval of acceleration of notes.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 22 Foreign Relations 1 2013-04-01 2013-04-01 false A.I.D. approval of acceleration of notes. 204.33 Section 204.33 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT HOUSING GUARANTY STANDARD TERMS AND CONDITIONS Covenants § 204.33 A.I.D. approval of acceleration of notes. Without the...

  9. 22 CFR 204.33 - A.I.D. approval of acceleration of notes.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false A.I.D. approval of acceleration of notes. 204.33 Section 204.33 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT HOUSING GUARANTY STANDARD TERMS AND CONDITIONS Covenants § 204.33 A.I.D. approval of acceleration of notes. Without the...

  10. 22 CFR 204.33 - A.I.D. approval of acceleration of notes.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 1 2011-04-01 2011-04-01 false A.I.D. approval of acceleration of notes. 204.33 Section 204.33 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT HOUSING GUARANTY STANDARD TERMS AND CONDITIONS Covenants § 204.33 A.I.D. approval of acceleration of notes. Without the...

  11. 22 CFR 204.33 - A.I.D. approval of acceleration of notes.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 22 Foreign Relations 1 2012-04-01 2012-04-01 false A.I.D. approval of acceleration of notes. 204.33 Section 204.33 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT HOUSING GUARANTY STANDARD TERMS AND CONDITIONS Covenants § 204.33 A.I.D. approval of acceleration of notes. Without the...

  12. Effect of lipid-bound apolipoprotein A-I cysteine mutant on ATF3 in RAW264.7 cells

    PubMed Central

    Wang, Yunlong; Wang, Yanhui; Jia, Shaoyou; Dong, Qingzhe; Chen, Yuanbin

    2017-01-01

    Activating transcription factor 3 (ATF3) is a TLR-induced repressor that plays an important role in the inhibition of specific inflammatory signals. We previously constructed recombinant high density lipoproteins (rHDL) (including rHDLWT, rHDLM, rHDL228 and rHDL74) and found that rHDL74 had a strong anti-inflammatory ability. In the present study, we investigate the roles of recombinant apolipoprotein A-I (ApoA-I) (rHDLWT) and its cysteine mutant HDLs (rHDLM, rHDL228 and rHDL74) on ATF3 function in RAW264.7 cells stimulated by lipopolysaccharide. Our results showed that compared with the LPS group, rHDL74 can decrease the level of TNF-α and IL-6, whereas rHDL228 increases their expression levels. RT-PCR and Western blotting results showed that compared with the LPS group, rHDL74, rHDLWT and rHDLM can markedly increase the expression level of ATF3, whereas the level of ATF3 decreases in the rHDL228 group. In summary, the different anti-inflammatory mechanisms of the ApoA-I cysteine mutants might be associated with the regulation of ATF3 level. PMID:28093456

  13. The Effect of Preoperative Apolipoprotein A-I on the Prognosis of Surgical Renal Cell Carcinoma: A Retrospective Large Sample Study.

    PubMed

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

    2016-03-01

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

  14. Serum Apolipoprotein A-I and Large High-Density Lipoprotein Particles Are Positively Correlated with FEV1 in Atopic Asthma

    PubMed Central

    Kaler, Maryann; Cuento, Rosemarie A.; Gordon, Elizabeth M.; Weir, Nargues A.; Sampson, Maureen; Fontana, Joseph R.; MacDonald, Sandra; Moss, Joel; Manganiello, Vincent; Remaley, Alan T.; Levine, Stewart J.

    2015-01-01

    Rationale: Although lipids, apolipoproteins, and lipoprotein particles are important modulators of inflammation, varying relationships exist between these parameters and asthma. Objectives: To determine whether serum lipids and apolipoproteins correlate with the severity of airflow obstruction in subjects with atopy and asthma. Methods: Serum samples were obtained from 154 atopic and nonatopic subjects without asthma, and 159 subjects with atopy and asthma. Serum lipid and lipoprotein levels were quantified using standard diagnostic assays and nuclear magnetic resonance (NMR) spectroscopy. Airflow obstruction was assessed by FEV1% predicted. Measurements and Main Results: Serum lipid levels correlated with FEV1 only in the subjects with atopy and asthma. Serum levels of high-density lipoprotein (HDL) cholesterol and apolipoprotein A-I (apoA-I) were positively correlated with FEV1 in subjects with atopy and asthma, whereas a negative correlation existed between FEV1 and serum levels of triglycerides, low-density lipoprotein (LDL) cholesterol, apolipoprotein B (apoB), and the apoB/apoA-I ratio. NMR spectroscopy identified a positive correlation between FEV1 and HDLNMR particle size, as well as the concentrations of large HDLNMR particles and total IDLNMR (intermediate-density lipoprotein) particles in subjects with atopy and asthma. In contrast, LDLNMR particle size and concentrations of LDLNMR and VLDLNMR (very-low-density lipoprotein) particles were negatively correlated with FEV1 in subjects with atopy and asthma. Conclusions: In subjects with atopy and asthma, serum levels of apoA-I and large HDLNMR particles are positively correlated with FEV1, whereas serum triglycerides, LDL cholesterol, and apoB are associated with more severe airflow obstruction. These results may facilitate future studies to assess whether apoA-I and large HDLNMR particles can reduce airflow obstruction and disease severity in asthma. PMID:25692941

  15. β3-Adrenoceptor activation upregulates apolipoprotein A-I expression in HepG2 cells, which might further promote cholesterol efflux from macrophage foam cells

    PubMed Central

    Gao, Xia-qing; Li, Yan-fang; Jiang, Zhi-li

    2017-01-01

    Objective The aim of this study was to explore the effects of β3-adrenoceptor (β3-AR) activation on HepG2 cells and its influence on cholesterol efflux from macrophage foam cells. Materials and methods HepG2 cells were cultured and treated with the β3-AR agonist, BRL37344, and antagonist, SR52390A, and the expression of apolipoprotein (Apo) A-I, ApoA-II, ApoB, and β3-AR in the supernatants and cells was determined. The expression of peroxisome proliferator-activated receptor (PPAR) γ and PPARα in the HepG2 cells was also assessed. Next, using the RAW264.7 macrophage foam cell model, we also assessed the influence of the HepG2 cell supernatants on lipid efflux. The cholesterol content of the foam cells was also measured, and the cholesterol efflux from the macrophages was examined by determining 3H-labeled cholesterol levels. Expression of ATP-binding cassette transporter (ABC) A1 and ABCG1 of the macrophage foam cells was also assessed. Results β3-AR activation increased ApoA-I expression in both the HepG2 cells and the supernatants; PPARγ expression was upregulated, but PPARα expression was not. Treatment with GW9662 abolished the increased expression of ApoA-I induced by the β3-AR agonist. The HepG2 cell supernatants decreased the lipid accumulation and increased the cholesterol efflux from the macrophage foam cells. ABCA1 expression, but not ABCG1 expression, increased in the macrophage foam cells treated with BRL37344-treated HepG2 cell supernatants. Conclusion Activation of β3-AR in HepG2 cells upregulates ApoA-I expression, which might further promote cholesterol efflux from macrophage foam cells. PPARγ might be required for the induction of ApoA-I expression. PMID:28424539

  16. β3-Adrenoceptor activation upregulates apolipoprotein A-I expression in HepG2 cells, which might further promote cholesterol efflux from macrophage foam cells.

    PubMed

    Gao, Xia-Qing; Li, Yan-Fang; Jiang, Zhi-Li

    2017-01-01

    The aim of this study was to explore the effects of β3-adrenoceptor (β3-AR) activation on HepG2 cells and its influence on cholesterol efflux from macrophage foam cells. HepG2 cells were cultured and treated with the β3-AR agonist, BRL37344, and antagonist, SR52390A, and the expression of apolipoprotein (Apo) A-I, ApoA-II, ApoB, and β3-AR in the supernatants and cells was determined. The expression of peroxisome proliferator-activated receptor (PPAR) γ and PPARα in the HepG2 cells was also assessed. Next, using the RAW264.7 macrophage foam cell model, we also assessed the influence of the HepG2 cell supernatants on lipid efflux. The cholesterol content of the foam cells was also measured, and the cholesterol efflux from the macrophages was examined by determining (3)H-labeled cholesterol levels. Expression of ATP-binding cassette transporter (ABC) A1 and ABCG1 of the macrophage foam cells was also assessed. β3-AR activation increased ApoA-I expression in both the HepG2 cells and the supernatants; PPARγ expression was upregulated, but PPARα expression was not. Treatment with GW9662 abolished the increased expression of ApoA-I induced by the β3-AR agonist. The HepG2 cell supernatants decreased the lipid accumulation and increased the cholesterol efflux from the macrophage foam cells. ABCA1 expression, but not ABCG1 expression, increased in the macrophage foam cells treated with BRL37344-treated HepG2 cell supernatants. Activation of β3-AR in HepG2 cells upregulates ApoA-I expression, which might further promote cholesterol efflux from macrophage foam cells. PPARγ might be required for the induction of ApoA-I expression.

  17. Apolipoproteins A-I, A-II and E in cholestatic liver disease.

    PubMed

    Florén, C H; Gustafson, A

    1985-04-01

    Apolipoproteins A-I, A-II and E were determined in the plasma of nine patients (five females, four males) with cholestatic liver disease (eight patients with primary biliary cirrhosis and one patient with sclerosing cholangitis). Plasma concentrations were measured by electroimmunoassay in the fasting state, postprandially after ingestion of either 100 g fat as whipping cream or a light mixed meal with or without addition of wheat fibre. Concentrations of apolipoproteins A-I and A-II were low in patients with cholestatic liver disease and A-I levels correlated inversely with the severity of liver disease as measured by bilirubin levels (r = -0.66). No changes in plasma apolipoprotein A-I, A-II or E concentrations occurred postprandially. There was an inverse correlation between plasma concentrations of apolipoproteins A-I and E (p less than 0.05, r = -0.68). A close relation existed between the ratio of apolipoprotein E to apolipoprotein A-I and plasma bile salt concentration (r = 0.80, p less than 0.01) and serum bilirubin (r = 0.76, p less than 0.01). This implies that in cholestatic liver disease apolipoprotein E and A-I levels reflect the degree of cholestasis.

  18. Heparin and Methionine Oxidation Promote the Formation of Apolipoprotein A-I Amyloid Comprising α-Helical and β-Sheet Structures.

    PubMed

    Townsend, David; Hughes, Eleri; Hussain, Rohanah; Siligardi, Giuliano; Baldock, Sarah; Madine, Jillian; Middleton, David A

    2017-03-21

    Peptides derived from apolipoprotein A-I (apoA-I), the main component of high-density lipoprotein (HDL), constitute the main component of amyloid deposits that colocalize with atherosclerotic plaques. Here we investigate the molecular details of full-length, lipid-deprived apoA-I after assembly into insoluble aggregates under physiologically relevant conditions known to induce aggregation in vitro. Unmodified apoA-I is shown to remain soluble at pH 7 for at least 3 days, retaining its native α-helical-rich structure. Upon acidification to pH 4, apoA-I rapidly assembles into insoluble nonfibrillar aggregates lacking the characteristic cross-β features of amyloid. In the presence of heparin, the rate and thioflavin T responsiveness of the aggregates formed at pH 4 increase and short amyloid-like fibrils are observed, which give rise to amyloid-characteristic X-ray reflections at 4.7 and 10 Å. Solid-state nuclear magnetic resonance (SSNMR) and synchrotron radiation circular dichroism spectroscopy of fibrils formed in the presence of heparin show they retain some α-helical characteristics together with new β-sheet structures. Interestingly, SSNMR indicates a similar molecular structure of aggregates formed in the absence of heparin at pH 6 after oxidation of the three methionine residues, although their morphology is rather different from that of the heparin-derived fibrils. We propose a model for apoA-I aggregation in which perturbations of a four-helix bundle-like structure, induced by interactions of heparin or methionine oxidation, cause the partially helical N-terminal residues to disengage from the remaining, intact helices, thereby allowing self-assembly via β-strand associations.

  19. D-4F, an apolipoprotein A-I mimetic, inhibits TGF-β1 induced epithelial-mesenchymal transition in human alveolar epithelial cell.

    PubMed

    You, Jia; Wang, Jintao; Xie, Linshen; Zhu, Chengwen; Xiong, Jingyuan

    2016-10-01

    Emerging evidences support that transforming growth factor β1 (TGF-β1) induced epithelial-mesenchymal transition (EMT) participates in the pathogenesis of pulmonary fibrosis and asthmatic airway remodeling. Recent studies demonstrated that apolipoprotein A-I (Apo A-I) is the only known substance that can resolve established pulmonary fibrotic nodules, and Apo A-I mimetic D-4F (a synthetic polypeptide consisting of 18 amino acids) plays an inhibitory role in murine asthmatic model. However, cellular mechanisms for such therapeutic effects of Apo A-I and D-4F remain to be elucidated. This study evaluated the effects of D-4F on TGF-β1 induced EMT in human type II alveolar epithelial cell line A549. A549 cells treated with 10ng/ml of TGF-β1 manifested distinct EMT, including fibroblastic morphological changes, down-regulation of epithelial marker E-cadherin and up-regulation of mesenchymal marker vimentin. These EMT related changes were all inhibited by D-4F in a concentration dependent manner. Transcriptional investigation demonstrated clearly that D-4F dose-dependently compensated for the reduced E-cadherin mRNA level and the increased vimentin mRNA level in TGF-β1 treated A549 cells. Translational analysis revealed that D-4F significantly reversed the TGF-β1 induced changes of E-cadherin and vimentin levels. These results suggested that D-4F inhibits TGF-β1 induced EMT in human alveolar epithelial cell. Given the functional similarities between D-4F and Apo A-I, it is speculated that D-4F and Apo A-I are able to exert possible anti-fibrotic and anti-asthmatic effects via inhibiting alveolar EMT, and D-4F may possess beneficial clinical potential for patients suffering from pulmonary fibrosis and asthma. Copyright © 2016 Elsevier GmbH. All rights reserved.

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

    PubMed Central

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

    2013-01-01

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

  1. Screening and identification of apolipoprotein A-I as a potential hepatoblastoma biomarker in children, excluding inflammatory factors.

    PubMed

    Zhao, Wei; Li, Juan; Zhang, Yilin; Gao, Pengfei; Zhang, Junjie; Guo, Fei; Yu, Jiekai; Zheng, Shu; Wang, Jiaxiang

    2015-07-01

    The aim of the present study was to identify a child hepatoblastoma serum biomarker that is unaffected by inflammatory factors, with the ultimate aim of finding an effective method for the early diagnosis of hepatoblastoma. The magnetic bead-based weak cation exchange chromatography technique was used to process serum harvested from 30 children with hepatoblastoma, 20 children with systemic inflammatory response syndrome (SIRS) and 20 healthy children. Proteins differentially expressed in SIRS were excluded from consideration as biomarkers for hepatoblastoma. Proteins differentially expressed in hepatoblastoma and healthy controls were screened using surface-enhanced laser desorption/ionization-time of flight-mass spectrometry (SELDI-TOF-MS). Target proteins were purified by SDS-PAGE, and matrix-assisted laser desorption/ionization (MALDI)-TOF-MS was used to determine their amino acid sequences. Protein matches were searched in the SwissProt database. Quantitative polymerase chain reaction (qPCR) and ELISA were employed to confirm the expression of target proteins. Following screening to exclude inflammatory factors, SELDI-TOF-MS revealed a protein with a mass-to-charge ratio of 9,348 Da that was expressed at significantly lower levels in the serum of children with hepatoblastoma compared with healthy controls (P<0.01). Sequence analysis identified this protein as apolipoprotein A-1 (Apo A-I). qPCR and ELISA confirmed that the expression of Apo A-I mRNA and protein were significantly lower in children with hepatoblastoma compared with healthy controls (P<0.05). These results indicate that Apo A-I is a non-inflammatory protein marker for hepatoblastoma with the potential for use in early diagnosis of hepatoblastoma. In addition, the present study demonstrates the feasibility of proteomic screening for the identification of proteins that can serve as markers for a specific tumor.

  2. Screening and identification of apolipoprotein A-I as a potential hepatoblastoma biomarker in children, excluding inflammatory factors

    PubMed Central

    ZHAO, WEI; LI, JUAN; ZHANG, YILIN; GAO, PENGFEI; ZHANG, JUNJIE; GUO, FEI; YU, JIEKAI; ZHENG, SHU; WANG, JIAXIANG

    2015-01-01

    The aim of the present study was to identify a child hepatoblastoma serum biomarker that is unaffected by inflammatory factors, with the ultimate aim of finding an effective method for the early diagnosis of hepatoblastoma. The magnetic bead-based weak cation exchange chromatography technique was used to process serum harvested from 30 children with hepatoblastoma, 20 children with systemic inflammatory response syndrome (SIRS) and 20 healthy children. Proteins differentially expressed in SIRS were excluded from consideration as biomarkers for hepatoblastoma. Proteins differentially expressed in hepatoblastoma and healthy controls were screened using surface-enhanced laser desorption/ionization-time of flight-mass spectrometry (SELDI-TOF-MS). Target proteins were purified by SDS-PAGE, and matrix-assisted laser desorption/ionization (MALDI)-TOF-MS was used to determine their amino acid sequences. Protein matches were searched in the SwissProt database. Quantitative polymerase chain reaction (qPCR) and ELISA were employed to confirm the expression of target proteins. Following screening to exclude inflammatory factors, SELDI-TOF-MS revealed a protein with a mass-to-charge ratio of 9,348 Da that was expressed at significantly lower levels in the serum of children with hepatoblastoma compared with healthy controls (P<0.01). Sequence analysis identified this protein as apolipoprotein A-1 (Apo A-I). qPCR and ELISA confirmed that the expression of Apo A-I mRNA and protein were significantly lower in children with hepatoblastoma compared with healthy controls (P<0.05). These results indicate that Apo A-I is a non-inflammatory protein marker for hepatoblastoma with the potential for use in early diagnosis of hepatoblastoma. In addition, the present study demonstrates the feasibility of proteomic screening for the identification of proteins that can serve as markers for a specific tumor. PMID:26171005

  3. PI3Kβ Plays a Key Role in Apolipoprotein A-I-Induced Endothelial Cell Proliferation Through Activation of the Ecto-F1-ATPase/P2Y1 Receptors.

    PubMed

    Castaing-Berthou, Audrey; Malet, Nicole; Radojkovic, Claudia; Cabou, Cendrine; Gayral, Stéphanie; Martinez, Laurent Olivier; Laffargue, Muriel

    2017-01-01

    High-density lipoproteins (HDL) exert multiple cardioprotective functions on the arterial wall, including the promotion of endothelial cell survival and proliferation. Among mechanism contributing to endothelial protection, it has been reported that apolipoprotein A-I (apoA-I), the major protein in HDL, binds and activates the endothelial ecto-F1-ATPase receptor. This generates extracellular ADP, which in turn promotes endothelial cell survival. In this study we aimed to further investigate the signaling pathway involved downstream of apoA-I-induced ecto-F1-ATPase activation. In human umbilical vein endothelial cells (HUVECs), pharmacological and gene silencing approaches were used to study pathways involved downstream ecto-F1-ATPase activation by apoA-I. ApoA-I and HDL both induced Akt phosphorylation. F1-ATPase inhibitors such as inhibitory factor 1 and oligomycin completely blocked apoA-I-induced Akt phosphorylaton and significantly blocked HDL-induced phosphorylation, indicating that this signaling pathway is dependent on ecto-F1-ATPase activation by apoA-I. Further, we were able to specify roles for the P2Y1-ADPreceptor and the PI3Kβ isoform in this pathway since pharmacological inhibition and silencing of these proteins dramatically inhibited apoA-I-induced Akt phosphorylation and cell proliferation. Altogether, these data highlight a key role of the P2Y1/PI3Kβ axis in endothelial cell proliferation downstream of ecto-F1-ATPase activation by apoA-I. Pharmacological targeting of this pathway could represent a promising approach to enhance vascular endothelial protection. © 2017 The Author(s). Published by S. Karger AG, Basel.

  4. A Comparison of the Theoretical Relationship between HDL Size and the Ratio of HDL Cholesterol to Apolipoprotein A-I with Experimental Results from the Women’s Health Study

    PubMed Central

    Mazer, Norman A.; Giulianini, Franco; Paynter, Nina P.; Jordan, Paul; Mora, Samia

    2013-01-01

    Background HDL size and composition vary among individuals and may be associated with cardiovascular disease and diabetes. We investigated the theoretical relationship between HDL size and composition using an updated version of the spherical model of lipoprotein structure proposed by Shen et al. and compared its predictions with experimental data from the Women’s Health Study (WHS). Methods The Shen model was updated to predict the relationship between HDL diameter and the ratio of HDL-cholesterol (HDL-C) to apolipoprotein A-I (ApoA-I) plasma concentrations, i.e., the HDL-C/ApoA-I ratio. In WHS (n=26,772), NMR spectroscopy was used to measure the average HDL diameter (davg,NMR) and particle concentration (HDL-P); HDL-C and ApoA-I (mg/dL) were measured by standardized assays. Results The updated Shen model predicts a quasi-linear increase of HDL diameter with the HDL-C/ApoA-I ratio, consistent with the measured davg,NMR values from WHS, which ranged between 8.0 and 10.8 nm and correlated positively with the HDL-C/ApoA-I ratio (r=0.608, p<2.2×10−16). The WHS data were further described by a linear regression equation: dWHS (nm) = 4.66 + 12.31 HDL-C/ApoA-I. The validity of this equation for estimating HDL size was assessed with data from CETP deficiency and pharmacologic inhibition. We also illustrate how HDL-P can be estimated from the HDL size and ApoA-I level. Conclusions This study provides a large-scale experimental examination of the updated Shen model, offers new insights into HDL structure, composition and remodeling, and suggests that the HDL-C/ApoA-I ratio could be a readily available biomarker for estimating HDL size and HDL-P. PMID:23426429

  5. 11. Photographed 19131914 by L. M. Leisenring, F.A.I.A. Presented by ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. Photographed 1913-1914 by L. M. Leisenring, F.A.I.A. Presented by Mr. Leisenring 1959 - Dr. David Ross House, Annapolis Road (moved to Preservation Hill, Western Run Road, Cockeysville), Bladensburg, Prince George's County, MD

  6. 10. Photographed 19131914 by L. M. Leisenring, F.A.I.A. Presented by ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. Photographed 1913-1914 by L. M. Leisenring, F.A.I.A. Presented by Mr. Leisenring 1959 - Dr. David Ross House, Annapolis Road (moved to Preservation Hill, Western Run Road, Cockeysville), Bladensburg, Prince George's County, MD

  7. Identification of Apolipoprotein A-I as a Retinoic Acid-binding Protein in the Eye.

    PubMed

    Summers, Jody A; Harper, Angelica R; Feasley, Christa L; Van-Der-Wel, Hanke; Byrum, Jennifer N; Hermann, Marcela; West, Christopher M

    2016-09-02

    All-trans-retinoic acid may be an important molecular signal in the postnatal control of eye size. The goal of this study was to identify retinoic acid-binding proteins secreted by the choroid and sclera during visually guided ocular growth. Following photoaffinity labeling with all-trans-[11,12-(3)H]retinoic acid, the most abundant labeled protein detected in the conditioned medium of choroid or sclera had an apparent Mr of 27,000 Da. Following purification and mass spectrometry, the Mr 27,000 band was identified as apolipoprotein A-I. Affinity capture of the radioactive Mr 27,000 band by anti-chick apolipoprotein A-I antibodies confirmed its identity as apolipoprotein A-I. Photoaffinity labeling and fluorescence quenching experiments demonstrated that binding of retinoic acid to apolipoprotein A-I is 1) concentration-dependent, 2) selective for all-trans-retinoic acid, and 3) requires the presence of apolipoprotein A-I-associated lipids for retinoid binding. Expression of apolipoprotein A-I mRNA and protein synthesis were markedly up-regulated in choroids of chick eyes during the recovery from induced myopia, and apolipoprotein A-I mRNA was significantly increased in choroids following retinoic acid treatment. Together, these data suggest that apolipoprotein A-I may participate in a regulatory feedback mechanism with retinoic acid to control the action of retinoic acid on ocular targets during postnatal ocular growth. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

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

    PubMed

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

    2016-03-04

    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. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  9. Chromatofocusing of human high density lipoproteins and isolation of lipoproteins A and A-I.

    PubMed

    Nestruck, A C; Niedmann, P D; Wieland, H; Seidel, D

    1983-08-29

    Using chromatofocusing, a column chromatography method with an internally generated pH gradient and focusing effects, human plasma high density lipoproteins (HDL) were fractionated into six subclasses within an interval of less than 1 pH unit (pH 5.1-4.2). All fractions floated in the ultracentrifuge at density = 1.21 g X ml-1, retained a typical HDL electron micrographic morphology and as a single band, alpha-migration on agarose electrophoresis. Compositional analysis of the subclasses revealed an inverse relationship between cholesterol ester and cholesterol on a molar basis. Distinct differences in the distribution of the apolipoproteins between the fractions were found. Two of the subclasses contained only apolipoprotein A-I and were therefore considered to be two forms of the lipid-combined form of apolipoprotein A-I, i.e., lipoprotein A-I. One subclass contained only apolipoproteins A-I + A-II and was, therefore, lipoprotein A. One subclass contained apolipoproteins A-I + A-II + D, and the two remaining contained additionally apolipoproteins C and E. Lipoprotein A-I was also demonstrated after immunoabsorption of apolipoprotein A-II-containing lipoproteins from whole serum. It is suggested that this method, which allows the fractionation of HDL into subclasses with distinct differences in apolipoprotein composition, offers new avenues for the study of the structural and metabolic heterogeneity of HDL.

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

    PubMed

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

    2016-05-01

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

  11. An apolipoprotein A-I mimetic peptide designed with a reductionist approach stimulates reverse cholesterol transport and reduces atherosclerosis in mice.

    PubMed

    Ditiatkovski, Michael; D'Souza, Wilissa; Kesani, Rajitha; Chin-Dusting, Jaye; de Haan, Judy B; Remaley, Alan; Sviridov, Dmitri

    2013-01-01

    Apolipoprotein A-I (apoA-I) mimetic peptides are considered a promising novel therapeutic approach to prevent and/or treat atherosclerosis. An apoA-I mimetic peptide ELK-2A2K2E was designed with a reductionist approach and has shown exceptional activity in supporting cholesterol efflux but modest anti-inflammatory and anti-oxidant properties in vitro. In this study we compared these in vitro properties with the capacity of this peptide to modify rates of reverse cholesterol transport and development of atherosclerosis in mouse models. The peptide enhanced the rate of reverse cholesterol transport in C57BL/6 mice and reduced atherosclerosis in Apoe(-/-) mice receiving a high fat diet. The peptide modestly reduced the size of the plaques in aortic arch, but was highly active in reducing vascular inflammation and oxidation. Administration of the peptide to Apoe(-/-) mice on a high fat diet reduced the levels of total, high density lipoprotein and non-high density lipoprotein cholesterol and triglycerides. It increased the proportion of smaller HDL particles in plasma at the expense of larger HDL particles, and increased the capacity of the plasma to support cholesterol efflux. Thus, ELK-2A2K2E peptide reduced atherosclerosis in Apoe(-/-) mice, however, the functional activity profile after chronic in vivo administration was different from that found in acute in vitro studies.

  12. Apolipoprotein A-I exchange is impaired in metabolic syndrome patients asymptomatic for diabetes and cardiovascular disease.

    PubMed

    Borja, Mark S; Hammerson, Bradley; Tang, Chongren; Savinova, Olga V; Shearer, Gregory C; Oda, Michael N

    2017-01-01

    We tested the hypothesis that HDL-apolipoprotein A-I exchange (HAE), a measure of high-density lipoprotein (HDL) function and a key step in reverse cholesterol transport (RCT), is impaired in metabolic syndrome (MetSyn) patients who are asymptomatic for diabetes and cardiovascular disease. We also compared HAE with cell-based cholesterol efflux capacity (CEC) to address previous reports that CEC is enhanced in MetSyn populations. HAE and ABCA1-specific CEC were measured as tests of HDL function in 60 MetSyn patients and 14 normolipidemic control subjects. Predictors of HAE and CEC were evaluated with multiple linear regression modeling using clinical markers of MetSyn and CVD risk. HAE was significantly reduced in MetSyn patients (49.0 ± 10.9% vs. 61.2 ± 6.1%, P < 0.0001), as was ABCA1-specific CEC (10.1 ± 1.6% vs. 12.3 ± 2.0%, P < 0.002). Multiple linear regression analysis identified apoA-I concentration as a significant positive predictor of HAE, and MetSyn patients had significantly lower HAE per mg/dL of apoA-I (P = 0.004). MetSyn status was a negative predictor of CEC, but triglyceride (TG) was a positive predictor of CEC, with MetSyn patients having higher CEC per mg/dL of TG, but lower overall CEC compared to controls. MetSyn patients have impaired HAE that contributes to reduced capacity for ABCA1-mediated CEC. MetSyn status is inversely correlated with CEC but positively correlated with TG, which explains the contradictory results from earlier MetSyn studies focused on CEC. HAE and CEC are inhibited in MetSyn patients over a broad range of absolute apoA-I and HDL particle levels, supporting the observation that this patient population bears significant residual cardiovascular disease risk.

  13. Apolipoprotein A-I exchange is impaired in metabolic syndrome patients asymptomatic for diabetes and cardiovascular disease

    PubMed Central

    Borja, Mark S.; Hammerson, Bradley; Tang, Chongren; Savinova, Olga V.; Shearer, Gregory C.

    2017-01-01

    Objective We tested the hypothesis that HDL-apolipoprotein A-I exchange (HAE), a measure of high-density lipoprotein (HDL) function and a key step in reverse cholesterol transport (RCT), is impaired in metabolic syndrome (MetSyn) patients who are asymptomatic for diabetes and cardiovascular disease. We also compared HAE with cell-based cholesterol efflux capacity (CEC) to address previous reports that CEC is enhanced in MetSyn populations. Methods HAE and ABCA1-specific CEC were measured as tests of HDL function in 60 MetSyn patients and 14 normolipidemic control subjects. Predictors of HAE and CEC were evaluated with multiple linear regression modeling using clinical markers of MetSyn and CVD risk. Results HAE was significantly reduced in MetSyn patients (49.0 ± 10.9% vs. 61.2 ± 6.1%, P < 0.0001), as was ABCA1-specific CEC (10.1 ± 1.6% vs. 12.3 ± 2.0%, P < 0.002). Multiple linear regression analysis identified apoA-I concentration as a significant positive predictor of HAE, and MetSyn patients had significantly lower HAE per mg/dL of apoA-I (P = 0.004). MetSyn status was a negative predictor of CEC, but triglyceride (TG) was a positive predictor of CEC, with MetSyn patients having higher CEC per mg/dL of TG, but lower overall CEC compared to controls. Conclusions MetSyn patients have impaired HAE that contributes to reduced capacity for ABCA1-mediated CEC. MetSyn status is inversely correlated with CEC but positively correlated with TG, which explains the contradictory results from earlier MetSyn studies focused on CEC. HAE and CEC are inhibited in MetSyn patients over a broad range of absolute apoA-I and HDL particle levels, supporting the observation that this patient population bears significant residual cardiovascular disease risk. PMID:28767713

  14. Renal apolipoprotein A-I amyloidosis: a rare and usually ignored cause of hereditary tubulointerstitial nephritis.

    PubMed

    Gregorini, Gina; Izzi, Claudia; Obici, Laura; Tardanico, Regina; Röcken, Christoph; Viola, Battista Fabio; Capistrano, Mariano; Donadei, Simona; Biasi, Luciano; Scalvini, Tiziano; Merlini, Giampaolo; Scolari, Francesco

    2005-12-01

    Apolipoprotein A-I amyloidosis is a rare, late-onset, autosomal dominant condition characterized by systemic deposition of amyloid in tissues, the major clinical problems being related to renal, hepatic, and cardiac involvement. Described is the clinical and histologic picture of renal involvement as a result of apolipoprotein A-I amyloidosis in five families of Italian ancestry. In all of the affected family members, the disease was caused by the Leu75Pro heterozygous mutation in exon 4 of apolipoprotein A-I gene, as demonstrated by direct sequencing and RFLP analysis. Immunohistochemistry confirmed that amyloid deposits were specifically stained with an anti-apolipoprotein A-I antibody. The clinical phenotype was mainly characterized by a variable combination of kidney and liver disturbance. The occurrence of renal involvement seemed to be almost universal, although its severity varied greatly ranging from subclinical organ damage to overt, slowly progressive renal dysfunction. The renal presentation was consistent with a tubulointerstitial disease, as suggested by the findings of defective urine-concentrating capacity, moderate polyuria, negative urinalysis, and mild tubular proteinuria. Histology confirmed tubulointerstitial nephritis. Surprising, amyloid was restricted to nonglomerular regions and limited to the renal medulla. This location of apolipoprotein A-I amyloid differs sharply from other systemic amyloidoses that are mainly characterized by glomerular and vascular deposits. The tubulointerstitial nephritis as a result of hereditary apolipoprotein A-I amyloidosis is a rare disease and a challenging diagnosis to recognize. Patients who present with familial tubulointerstitial nephritis associated with liver disease require a high index of suspicion for apolipoprotein A-I amyloidosis.

  15. TRL, IDL, and LDL apolipoprotein B-100 and HDL apolipoprotein A-I kinetics as a function of age and menopausal status.

    PubMed

    Matthan, Nirupa R; Jalbert, Susan M; Lamon-Fava, Stefania; Dolnikowski, Gregory G; Welty, Francine K; Barrett, Hugh R; Schaefer, Ernst J; Lichtenstein, Alice H

    2005-08-01

    To determine mechanisms contributing to the altered lipoprotein profile associated with aging and menopause, apolipoprotein B-100 (apoB-100) and apoA-I kinetic behavior was assessed. Eight premenopausal (25+/-3 years) and 16 postmenopausal (65+/-6 years) women consumed for 6 weeks a standardized Western diet, at the end of which a primed-constant infusion of deuterated leucine was administered in the fed state to determine the kinetic behavior of triglyceride-rich lipoprotein (TRL), intermediate-density lipoprotein (IDL), and low-density lipoprotein (LDL) apoB-100, and high-density lipoprotein (HDL) apoA-I. Data were fit to a multicompartmental model using SAAM II to calculate fractional catabolic rate (FCR) and production rate (PR). Total cholesterol, LDL cholesterol (LDL-C), TRL-C, and triglyceride levels were higher (50%, 55%, 130%, and 232%, respectively) in the postmenopausal compared with the premenopausal women, whereas HDL-C levels were similar. Plasma TRL, IDL, and LDL-apoB-100 levels and pool sizes (PS) were significantly higher in the postmenopausal than premenopausal women. These differences were accounted for by lower TRL, IDL, and LDL apoB-100 FCR (P<0.05), with no difference in PR. There was no significant difference between groups in HDL-C levels or apoA-I kinetic parameters. Plasma TRL-C concentrations were negatively correlated with TRL apoB-100 FCR (r=-0.46; P<0.05) and positively correlated with PR (r=0.62; P<0.01). Plasma LDL-C concentrations were negatively correlated with LDL apoB-100 FCR (r=-0.70; P<0.001) but not PR. The mechanism for the increase in TRL and LDL apoB-100 PS observed in the postmenopausal women was determined predominantly by decreased TRL and LDL catabolism rather than increased production. No differences were observed in HDL apoA-I kinetics between groups.

  16. Abnormal histopathology, fat percent and hepatic apolipoprotein A I and apolipoprotein B100 mRNA expression in fatty liver hemorrhagic syndrome and their improvement by soybean lecithin.

    PubMed

    Song, Yalu; Ruan, Jiming; Luo, Junrong; Wang, Tiancheng; Yang, Fei; Cao, Huabin; Huang, Jianzhen; Hu, Guoliang

    2017-10-01

    To investigate the etiopathogenesis of fatty liver hemorrhagic syndrome (FLHS) and the protective effects of soybean lecithin against FLHS in laying hens, 135 healthy 300-day-old Hyline laying hens were randomly divided into groups: control (group 1), diseased (group 2), and protected (group 3). Each group contained 45 layers with 3 replicates. The birds in these 3 groups were fed a control diet, a high-energy/low-protein (HELP) diet or the HELP diet supplemented with 3% soybean lecithin instead of maize. The fat percent in the liver was calculated. Histopathological changes in the liver were determined by staining, and the mRNA expression levels of apolipoproteinA I (apoA I) and apolipoprotein B100 (apoB100) in the liver were determined by RT-PCR. The results showed that the fat percent in the liver of group 2 was much higher (P < 0.01) than that of group 1 and group 2 on d 30 and 60. The histology of the liver in group 2 on d 30 and 60 displayed various degrees of liver lesions, while the hepatocytes showed a normal structure in group 3 with mild microvesicular steatosis in the liver cell on d 30 and 60. The mRNA expression levels of apoA I and apoB100 in the livers were variable throughout the experiment. The expression level of apoA I in group 2 significantly decreased on d 60 (P < 0.05); the expression level of apoB100 slightly increased on d 30 in group 2, while it sharply decreased on d 60. Compared to group 1, the expression level of apoB100 showed no significant difference in group 3 (P < 0.05). This study indicated that FLHS induced pathological changes and abnormal expression of apoA I and apoB100 in the livers of laying hens and that soybean lecithin alleviated these abnormal changes. © 2017 Poultry Science Association Inc.

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

    PubMed Central

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

    2015-01-01

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

  18. High-density lipoprotein and apolipoprotein A-I inhibit palmitate-induced translocation of toll-like receptor 4 into lipid rafts and inflammatory cytokines in 3T3-L1 adipocytes.

    PubMed

    Yamada, Hodaka; Umemoto, Tomio; Kawano, Mikihiko; Kawakami, Masanobu; Kakei, Masafumi; Momomura, Shin-Ichi; Ishikawa, San-E; Hara, Kazuo

    2017-03-04

    Saturated fatty acids (SFAs) activate toll-like receptor 4 (TLR4) signal transduction in macrophages and are involved in the chronic inflammation accompanying obesity. High-density lipoprotein (HDL) and apolipoprotein A-I (apoA-I) produce anti-inflammatory effects via reverse cholesterol transport. However, the underlying mechanisms by which HDL and apoA-I inhibit inflammatory responses in adipocytes remain to be determined. Here we examined whether palmitate increases the translocation of TLR4 into lipid rafts and whether HDL and apoA-I inhibit inflammation in adipocytes. Palmitate exposure (250 μM, 24 h) increased interleukin-6 and tumor necrosis factor-α gene expressions and translocation of TLR4 into lipid rafts in 3T3-L1 adipocytes. Pretreatment with HDL and apoA-I (50 μg/mL, 6 h) suppressed palmitate-induced inflammatory cytokine expression and TLR4 translocation into lipid rafts. Moreover, HDL and apoA-I inhibited palmitate-induced phosphorylation of nuclear factor-kappa B. HDL showed an anti-inflammatory effect via ATP-binding cassette transporter G1 and scavenger receptor class B, member 1, whereas apoA-I showed an effect via ATP-binding cassette transporter A1. These results demonstrated that HDL and apoA-I reduced palmitate-potentiated TLR4 trafficking into lipid rafts and its related inflammation in adipocytes via these specific transporters. Copyright © 2017. Published by Elsevier Inc.

  19. Insulin-Mediated Downregulation of Apolipoprotein A-I Gene in Human Hepatoma Cell Line HepG2: The Role of Interaction Between FOXO1 and LXRβ Transcription Factors.

    PubMed

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

    2017-02-01

    Apolipoprotein A-I (ApoA-I) is a key component of high density lipoproteins which possess anti-atherosclerotic and anti-inflammatory properties. Insulin is a crucial mediator of the glucose and lipid metabolism that has been implicated in atherosclerotic and inflammatory processes. Important mediators of insulin signaling such as Liver X Receptors (LXRs) and Forkhead Box A2 (FOXA2) are known to regulate apoA-I expression in liver. Forkhead Box O1 (FOXO1) is a well-known target of insulin signaling and a key mediator of oxidative stress response. Low doses of insulin were shown to activate apoA-I expression in human hepatoma HepG2 cells. However, the detailed mechanisms for these processes are still unknown. We studied the possible involvement of FOXO1, FOXA2, LXRα, and LXRβ transcription factors in the insulin-mediated regulation of apoA-I expression. Treatment of HepG2 cells with high doses of insulin (48 h, 100 nM) suppresses apoA-I gene expression. siRNAs against FOXO1, FOXA2, LXRβ, or LXRα abrogated this effect. FOXO1 forms a complex with LXRβ and insulin treatment impairs FOXO1/LXRβ complex binding to hepatic enhancer and triggers its nuclear export. Insulin as well as LXR ligand TO901317 enhance the interaction between FOXA2, LXRα, and hepatic enhancer. These data suggest that high doses of insulin downregulate apoA-I gene expression in HepG2 cells through redistribution of FOXO1/LXRβ complex, FOXA2, and LXRα on hepatic enhancer of apoA-I gene. J. Cell. Biochem. 118: 382-396, 2017. © 2016 Wiley Periodicals, Inc.

  20. 22 CFR 214.31 - A.I.D. Advisory Committee Representative.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... MANAGEMENT Operation of Advisory Committees § 214.31 A.I.D. Advisory Committee Representative. (a) For each... with the Advisory Committee Management Officer and the General Counsel for decisions by the... Advisory Committee Management Officer. (5) Assuring that open meetings are accessible to the public; (6) As...

  1. 22 CFR 214.31 - A.I.D. Advisory Committee Representative.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... MANAGEMENT Operation of Advisory Committees § 214.31 A.I.D. Advisory Committee Representative. (a) For each... with the Advisory Committee Management Officer and the General Counsel for decisions by the... Advisory Committee Management Officer. (5) Assuring that open meetings are accessible to the public; (6) As...

  2. [To the history of Tretiyakov almshouse of the A.I. Vishnevskiy Institute of Surgery].

    PubMed

    Kuzybayeva, M P

    2014-01-01

    The article deals with reconstruction of history of building and functioning of Tretiyakov almshouse in the A.I. Vishnevskiy institute of surgery. The archive documents were used for exploration. The input of architect S.I. Soloviyev into formation of architectural complex is demonstrated. The significance of this object in the history of national architecture is established.

  3. 22 CFR 214.31 - A.I.D. Advisory Committee Representative.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... MANAGEMENT Operation of Advisory Committees § 214.31 A.I.D. Advisory Committee Representative. (a) For each... with the Advisory Committee Management Officer and the General Counsel for decisions by the... Advisory Committee Management Officer. (5) Assuring that open meetings are accessible to the public; (6)...

  4. Transcriptome-wide identification of A > I RNA editing sites by inosine specific cleavage

    PubMed Central

    Cattenoz, Pierre B.; Taft, Ryan J.; Westhof, Eric; Mattick, John S.

    2013-01-01

    Adenosine to inosine (A > I) RNA editing, which is catalyzed by the ADAR family of proteins, is one of the fundamental mechanisms by which transcriptomic diversity is generated. Indeed, a number of genome-wide analyses have shown that A > I editing is not limited to a few mRNAs, as originally thought, but occurs widely across the transcriptome, especially in the brain. Importantly, there is increasing evidence that A > I editing is essential for animal development and nervous system function. To more efficiently characterize the complete catalog of ADAR events in the mammalian transcriptome we developed a high-throughput protocol to identify A > I editing sites, which exploits the capacity of glyoxal to protect guanosine, but not inosine, from RNAse T1 treatment, thus facilitating extraction of RNA fragments with inosine bases at their termini for high-throughput sequencing. Using this method we identified 665 editing sites in mouse brain RNA, including most known sites and suite of novel sites that include nonsynonymous changes to protein-coding genes, hyperediting of genes known to regulate p53, and alterations to non-protein-coding RNAs. This method is applicable to any biological system for the de novo discovery of A > I editing sites, and avoids the complicated informatic and practical issues associated with editing site identification using traditional RNA sequencing data. This approach has the potential to substantially increase our understanding of the extent and function of RNA editing, and thereby to shed light on the role of transcriptional plasticity in evolution, development, and cognition. PMID:23264566

  5. Retrospective analysis of NRECA's (National Rural Electric Cooperative Association) activities with A. I. D. funding 1962-1981

    SciTech Connect

    Not Available

    1981-01-01

    Rural electrification (RE) has proven to be one of A.I.D.'s most effective responses to Congressional mandates to serve the poor and do so through cooperatives when possible. This report overviews the National Rural Electric Cooperative Associations (NRECA) 20-year experience in providing developing countries with A.I.D.-financed technical assistance and training; examines NRECA-A.I.D. relationships; provides examples of NRECA's performance in 17 countries; briefly describes non-A.I.D. NRECA projects; and identifies opportunities for NRECA and A.I.D. to jointly undertake a broader range of energy-related activities in the future.

  6. Impact of corpulence parameters and haemoglobin A1c on metabolic control in type 2 diabetic patients: comparison of apolipoprotein B/A-I ratio with fasting and postprandial conventional lipid ratios

    PubMed Central

    Diaf, Mustapha; Khaled, Boumediene M.; Sellam, Fériel

    2015-01-01

    Background and objective The incidence of diabetes co-morbidities could probably be better assessed by studying its associations with major corpulence parameters and glycaemic control indicators. We assessed the utility of body mass index (BMI), waist circumference (WC), and glycosylated haemoglobin (HbA1c) levels in metabolic control for type 2 diabetic patients. Methods Fasting and postprandial blood samples were collected from 238 type 2 diabetic patients aged 57.4±11.9 years. The sera were analysed for glucose, HbA1c, total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-c), low-density lipoprotein cholesterol (LDL-c), and apolipoproteins (apoA-I and apoB). Ratios of lipids and apolipoproteins were calculated and their associations with BMI, WC, and HbA1c levels were analysed. Results Our investigation showed increases in most fasting and postprandial lipid parameters according to BMI and WC. In men, postprandial HDL-c and TG levels were significantly higher (p<0.05) in overweight and obese patients, respectively, as well as in patients with abdominal obesity. Contrariwise, postprandial TC levels were significantly higher (p<0.01) in overweight and abdominal obese women. However, elevations of apoA-I and apoB levels were according to BMI and WC in both genders. There was a strong influence of BMI, WC, and HbA1c levels on the apoB/apoA-I ratio compared to traditional fasting and postprandial lipid ratios in both men and women. The apoB/apoA-I ratio was more correlated with postprandial TC/HDL and LDL-c/HDL-c ratios in men and with postprandial TG/HDL-c in women. Conclusion The apoB/apoA-I ratio is helpful in assessing metabolic risk caused by overall obesity, abdominal obesity and impaired glycaemia in type 2 diabetic patients. PMID:25959906

  7. Ochracenes A-I, Humulane-Derived Sesquiterpenoids from the Antarctic Fungus Aspergillus ochraceopetaliformis.

    PubMed

    Wang, Junfeng; He, Weijun; Kong, Fandong; Tian, Xinpeng; Wang, Pei; Zhou, Xiaojiang; Liu, Yonghong

    2017-06-23

    Nine new humulane-derived sesquiterpenoids, ochracenes A-I (1-9), were isolated from the Antarctic fungus Aspergillus ochraceopetaliformis SCSIO 05702. Their structures including absolute configurations were elucidated on the basis of spectroscopic analysis, Mosher's method, and electronic circular dichroism analysis. Compared with previous humulane-type sesquiterpenoids, ochracenes A-I (1-9) featured novel carbon skeletons with corresponding methyl migration, ring cleavage, and carbon loss. Two unprecedented 8,9-secocyclic sesquiterpenoids (2 and 3) exhibited inhibitory effects on lipopolysaccharide-induced NO release in RAW 264.7 mouse macrophage cell lines with IC50 values of 14.6 ± 0.5 and 18.3 ± 1.7 μM, respectively.

  8. 8. Print of a drawing: "Plan No. 24, A.I. No. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. Print of a drawing: "Plan No. 24, A.I. No. 00036-A, Bldg. 27 (no date). Probably not of Building 27, but a similar heating installation elsewhere on the fort, or an alternate plan for the building which was never constructed. (8" x 10" print enlarged from 4" x 5" negative.) - Fort Benjamin Harrison, Building No. 27, Otis Avenue east of Green Avenue, Lawrence, Marion County, IN

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

    PubMed Central

    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

    2016-01-01

    Apolipoprotein (apo) A-I mediates many of the anti-atherogenic functions attributed to high density lipoprotein. Unfortunately, efforts toward a high resolution structure of full-length apoA-I have not been fruitful, although there have been successes with deletion mutants. Recently, a C-terminal truncation (apoA-IΔ185–243) 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-IΔ185–243 in its dimeric and monomeric forms. For the dimer, we found evidence for the shared domains and aspects of the N-terminal bundles, but not the molecular curvature seen in the crystal. We also found that the N-terminal bundles equilibrate between open and closed states. Interestingly, this movement is one of the transitions proposed during lipid binding. The monomer was consistent with a model in which the long shared helix doubles back onto the helical bundle. Combined with the crystal structure, these data offer an important starting point to understand the molecular details of high density lipoprotein biogenesis. PMID:26755744

  10. Lipid-Free Apolipoprotein A-I Reduces Progression of Atherosclerosis by Mobilizing Microdomain Cholesterol and Attenuating the Number of CD131 Expressing Cells: Monitoring Cholesterol Homeostasis Using the Cellular Ester to Total Cholesterol Ratio.

    PubMed

    Kaul, Sushma; Xu, Hao; Zabalawi, Manal; Maruko, Elisa; Fulp, Brian E; Bluemn, Theresa; Brzoza-Lewis, Kristina L; Gerelus, Mark; Weerasekera, Ranjuna; Kallinger, Rachel; James, Roland; Zhang, Yi Sherry; Thomas, Michael J; Sorci-Thomas, Mary G

    2016-11-07

    Atherosclerosis is a chronic inflammatory disorder whose development is inversely correlated with high-density lipoprotein concentration. Current therapies involve pharmaceuticals that significantly elevate plasma high-density lipoprotein cholesterol concentrations. Our studies were conducted to investigate the effects of low-dose lipid-free apolipoprotein A-I (apoA-I) on chronic inflammation. The aims of these studies were to determine how subcutaneously injected lipid-free apoA-I reduces accumulation of lipid and immune cells within the aortic root of hypercholesterolemic mice without sustained elevations in plasma high-density lipoprotein cholesterol concentrations. Ldlr(-/-) and Ldlr(-/-) apoA-I(-/-) mice were fed a Western diet for a total of 12 weeks. After 6 weeks, a subset of mice from each group received subcutaneous injections of 200 μg of lipid-free human apoA-I 3 times a week, while the other subset received 200 μg of albumin, as a control. Mice treated with lipid-free apoA-I showed a decrease in cholesterol deposition and immune cell retention in the aortic root compared with albumin-treated mice, regardless of genotype. This reduction in atherosclerosis appeared to be directly related to a decrease in the number of CD131 expressing cells and the esterified cholesterol to total cholesterol content in several immune cell compartments. In addition, apoA-I treatment altered microdomain cholesterol composition that shifted CD131, the common β subunit of the interleukin 3 receptor, from lipid raft to nonraft fractions of the plasma membrane. ApoA-I treatment reduced lipid and immune cell accumulation within the aortic root by systemically reducing microdomain cholesterol content in immune cells. These data suggest that lipid-free apoA-I mediates beneficial effects through attenuation of immune cell lipid raft cholesterol content, which affects numerous types of signal transduction pathways that rely on microdomain integrity for assembly and

  11. Francisella tularensis Subtype A.II Genomic Plasticity in Comparison with Subtype A.I

    PubMed Central

    Larson, Marilynn A.; Nalbantoglu, Ufuk; Sayood, Khalid; Zentz, Emily B.; Bartling, Amanda M.; Francesconi, Stephen C.; Fey, Paul D.; Dempsey, Michael P.; Hinrichs, Steven H.

    2015-01-01

    Although Francisella tularensis is considered a monomorphic intracellular pathogen, molecular genotyping and virulence studies have demonstrated important differences within the tularensis subspecies (type A). To evaluate genetic variation within type A strains, sequencing and assembly of a new subtype A.II genome was achieved for comparison to other completed F. tularensis type A genomes. In contrast with the F. tularensis A.I strains (SCHU S4, FSC198, NE061598, and TI0902), substantial genomic variation was observed between the newly sequenced F. tularensis A.II strain (WY-00W4114) and the only other publically available A.II strain (WY96-3418). Genome differences between WY-00W4114 and WY96-3418 included three major chromosomal translocations, 1580 indels, and 286 nucleotide substitutions of which 159 were observed in predicted open reading frames and 127 were located in intergenic regions. The majority of WY-00W4114 nucleotide deletions occurred in intergenic regions, whereas most of the insertions and substitutions occurred in predicted genes. Of the nucleotide substitutions, 48 (30%) were synonymous and 111 (70%) were nonsynonymous. WY-00W4114 and WY96-3418 nucleotide polymorphisms were predominantly G/C to A/T allelic mutations, with WY-00W4114 having more A+T enrichment. In addition, the A.II genomes contained a considerably higher number of intact genes and longer repetitive sequences, including transposon remnants than the A.I genomes. Together these findings support the premise that F. tularensis A.II may have a fitness advantage compared to the A.I subtype due to the higher abundance of functional genes and repeated chromosomal sequences. A better understanding of the selective forces driving F. tularensis genetic diversity and plasticity is needed. PMID:25918839

  12. Pig major acute-phase protein and apolipoprotein A-I responses correlate with the clinical course of experimentally induced African Swine Fever and Aujeszky's disease.

    PubMed

    Carpintero, Rakel; Alonso, Covadonga; Piñeiro, Matilde; Iturralde, María; Andrés, Marta; Le Potier, Marie-Frédérique; Madec, Francois; Alava, María A; Piñeiro, Andrés; Lampreave, Fermín

    2007-01-01

    In the present work, we studied the acute phase protein response after experimental virus infection in pigs. The animals were experimentally infected with African Swine Fever (ASF) or Aujeszky's disease (AD) viruses. The clinical course of ASF infection correlated with increasingly high levels of pig Major Acute-phase Protein (pig-MAP) (mean value of 6 mg/mL on day 6 post infection (p.i.), from 6 to 9 times higher than day 0) and sharp apolipoprotein A-I (apo A-I) decrease (mean value of 0.5 mg/mL, from 4 to 10 times lower than day 0 on day 4 p.i.). AD-clinical signs appeared at day 3 p.i., both in vaccinated (moderate clinical signs) and non-vaccinated pigs (severe outcome within 48 h p.i.). Pig-MAP and apo A-I profiles also followed clinical signs (changing from 0.70 mg/mL to around 3 mg/mL and from around 3 mg/mL to 0.96 mg/mL, respectively in non-vaccinated animals), with minor changes in concentration in the vaccinated group. Haptoglobin levels significantly increased in ASF and AD infected animals (mean maximum values of 2.77 and 3.96 mg/mL, respectively). Minor differences for the C-Reactive Protein in the case of ASF were observed, whereas its concentration increased more than 7 times in AD-infection. The albumin level was not modified in either case. The correlation of clinical signs to our data suggests the potential use of pig-MAP and apo A-I in monitoring infections in swine.

  13. Depletion in LpA-I:A-II particles enhances HDL-mediated endothelial protection in familial LCAT deficiency.

    PubMed

    Gomaraschi, Monica; Ossoli, Alice; Castelnuovo, Samuela; Simonelli, Sara; Pavanello, Chiara; Balzarotti, Gloria; Arca, Marcello; Di Costanzo, Alessia; Sampietro, Tiziana; Vaudo, Gaetano; Baldassarre, Damiano; Veglia, Fabrizio; Franceschini, Guido; Calabresi, Laura

    2017-05-01

    The aim of this study was to evaluate the vasoprotective effects of HDL isolated from carriers of LCAT deficiency, which are characterized by a selective depletion of LpA-I:A-II particles and predominance of preβ migrating HDL. HDLs were isolated from LCAT-deficient carriers and tested in vitro for their capacity to promote NO production and to inhibit vascular cell adhesion molecule-1 (VCAM-1) expression in cultured endothelial cells. HDLs from carriers were more effective than control HDLs in promoting eNOS activation with a gene-dose-dependent effect (PTrend = 0.048). As a consequence, NO production induced by HDL from carriers was significantly higher than that promoted by control HDL (1.63 ± 0.24-fold vs. 1.34 ± 0.07-fold, P = 0.031). HDLs from carriers were also more effective than control HDLs in inhibiting the expression of VCAM-1 (homozygotes, 65.0 ± 8.6%; heterozygotes, 53.1 ± 7.2%; controls, 44.4 ± 4.1%; PTrend = 0.0003). The increased efficiency of carrier HDL was likely due to the depletion in LpA-I:A-II particles. The in vitro findings might explain why carriers of LCAT deficiency showed flow-mediated vasodilation and plasma-soluble cell adhesion molecule concentrations comparable to controls, despite low HDL-cholesterol levels. These results indicate that selective depletion of apoA-II-containing HDL, as observed in carriers of LCAT deficiency, leads to an increased capacity of HDL to stimulate endothelial NO production, suggesting that changes in HDL apolipoprotein composition may be the target of therapeutic interventions designed to improve HDL functionality. Copyright © 2017 by the American Society for Biochemistry and Molecular Biology, Inc.

  14. 78 FR 64396 - Mixed Straddles; Straddle-by-Straddle Identification Under Section 1092(b)(2)(A)(i)(I); Correction

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-29

    ... Under Section 1092(b)(2)(A)(i)(I); Correction AGENCY: Internal Revenue Service (IRS), Treasury. ACTION... straddles; straddle-by-straddle identification under section 1092(b)(2)(A)(i)(I) (Temporary). * * * * * (b... regulations relating to guidance for taxpayers electing to establish a mixed straddle using straddle-by...

  15. Decomposition theorem in ideal topological spaces via a*-I-open sets and Asemi*-I-open sets

    NASA Astrophysics Data System (ADS)

    AL-Omeri, W.; Noorani, Mohd. Salmi.; AL-Omari, A.

    2014-09-01

    In this paper, we investigate some properties of a*-I-open set [3] and Asemi*-I-open sets defined in [3] in ideal topological space. The relationships of other related classes of sets are investigated. Also, a new decomposition of continuous functions is obtained by using δβA-I-open and SA*-set functions in an ideal topological space.

  16. [The history of military training at the First Moscow State Medical University n.a. I.M.Sechenov].

    PubMed

    Chizh, I M; Putilo, V M; Tregubov, V N; Timakov, V V

    2011-11-01

    In 2011, the oldest medical educational institution of Russia--the First Moscow State Medical University n. a. I.M.Sechenov celebrates 85 years of military training. Passing not easy, but at the same time, glorious path of military training in First MGMU n. a. I.M.Sechenov today occupies a key place in the training of military physicians.

  17. Tamarindus indica extract alters release of alpha enolase, apolipoprotein A-I, transthyretin and Rab GDP dissociation inhibitor beta from HepG2 cells.

    PubMed

    Chong, Ursula Rho Wan; Abdul-Rahman, Puteri Shafinaz; Abdul-Aziz, Azlina; Hashim, Onn Haji; Junit, Sarni Mat

    2012-01-01

    The plasma cholesterol and triacylglycerol lowering effects of Tamarindus indica extract have been previously described. We have also shown that the methanol extract of T. indica fruit pulp altered the expression of lipid-associated genes including ABCG5 and APOAI in HepG2 cells. In the present study, effects of the same extract on the release of proteins from the cells were investigated using the proteomics approach. When culture media of HepG2 cells grown in the absence and presence of the methanol extract of T. indica fruit pulp were subjected to 2-dimensional gel electrophoresis, the expression of seven proteins was found to be significantly different (p<0.03125). Five of the spots were subsequently identified as alpha enolase (ENO1), transthyretin (TTR), apolipoprotein A-I (ApoA-I; two isoforms), and rab GDP dissociation inhibitor beta (GDI-2). A functional network of lipid metabolism, molecular transport and small molecule biochemistry that interconnects the three latter proteins with the interactomes was identified using the Ingenuity Pathways Analysis software. The methanol extract of T. indica fruit pulp altered the release of ENO1, ApoA-I, TTR and GDI-2 from HepG2 cells. Our results provide support on the effect of T. indica extract on cellular lipid metabolism, particularly that of cholesterol.

  18. Natural resource management: A. I. D. 's experience in Nepal. Occasional paper

    SciTech Connect

    Chew, S.T.

    1990-10-01

    Since 1980, the Agency for International Development (A.I.D.) has invested about $77 million in projects to improve Nepal's natural resource management. The paper reviews the two largest projects; it also describes how USAID/Nepal is supporting multidonor forestry projects. The review identifies several important lessons. USAID/Nepal has been more effective in influencing policymaking and institutional changes when supporting multidonor projects than when acting alone. The reviewed projects underscore the difficulty of implementing large projects that involve technologies far beyond the host country's capabilities. More importantly, they demonstrate that support for resource conservation need not always be technically sophisticated, but sometimes can -- and should -- begin by integrating research and extension activities into existing agricultural and rural development projects. To gain farmer support, such activities should increase livestock and tree production without compromising food crop production. Efforts to decentralize forestry management should not stop at the local government but should involve the affected communities themselves.

  19. C1QBP is upregulated in colon cancer and binds to apolipoprotein A-I.

    PubMed

    Kim, Kun; Kim, Min-Jeong; Kim, Kyung-Hee; Ahn, Sun-A; Kim, Jong Heon; Cho, Jae Youl; Yeo, Seung-Gu

    2017-05-01

    The present study aimed to investigate the expression of complement component 1, q subcomponent-binding protein (C1QBP) in colon cancer cells, and identify proteins that interact with C1QBP. Total proteins were extracted from both the tumor and normal tissues of 22 patients with colon cancer and analyzed using liquid chromatography-mass spectrometry (LC-MS) to identify proteins that were differentially-expressed in tumor tissues. C1QBP overexpression was induced in 293T cells using a pFLAG-CMV2 expression vector. Overexpressed FLAG-tagged C1QBP protein was then immunoprecipitated using anti-FLAG antibodies and C1QBP-interacting proteins were screened using LC-MS analysis of the immunoprecipitates. The C1QBP-interacting proteins were confirmed using reverse-immunoprecipitation and the differential expression of C1QBP in tissues and cell lines was confirmed using western blot analysis. LC-MS analysis revealed that C1QBP exhibited a typical tumor expression pattern. Two immune-reactive signals (33 and 14 kDa) were detected in normal and tumor tissues from 19 patients. Furthermore, 14 kDa C1QBP protein was upregulated in the tumors of 15 patients. In total, 39 proteins were identified as candidate C1QBP-interacting proteins, and an interaction between C1QBP and apolipoprotein A-I was confirmed. The present study indicates that C1QBP is involved in colon cancer carcinogenesis, and that the mechanisms underlying the established anti-tumor properties of apolipoprotein A-I may include interacting with and inhibiting the activity of C1QBP.

  20. Controlling for apolipoprotein A-I concentrations changes the inverse direction of the relationship between high HDL-C concentration and a measure of pre-clinical atherosclerosis.

    PubMed

    Sung, Ki-Chul; Wild, Sarah H; Byrne, Christopher D

    2013-12-01

    The independent effect of high density lipoprotein cholesterol (HDL-C) concentration to confer cardiovascular disease protection has been questioned. We investigated whether the inverse association between HDL-C concentration and a measure of preclinical atherosclerosis was modified by other risk factors. Cross-sectional data were analysed from an occupational cohort of 12,031 men who had measurements of cardiovascular risk factors and a cardiac computed tomography (CT) estimation of coronary artery calcium (CAC) score, a measure of pre-clinical atherosclerosis. Logistic regression was used to describe associations between both HDL-C and Apo-A-I concentrations and their ratio as exposures, and CAC scores > 0, ≥ 20 and ≥ 100, as outcomes. 1351 (11.2%), 665 (5.5%) and 230 (1.9%) of participants had a CAC score > 0, ≥ 20 and ≥ 100, respectively. Adjusting for age, glucose, triglyceride, LDL-C, systolic blood pressure, waist circumference, prior cerebrovascular accident, prior coronary artery disease, prior hypertension, alcohol consumption, smoking status and exercise, a negative association existed between HDL-C and CAC score. (E.g. odds ratio (OR) for top compared to bottom HDL-C quartile for CAC > 0 = 0.78 [95%CI 0.64, 0.94], p = 0.01). Further adjustment for Apo A-I changed the direction of the association between HDL-C and CAC score > 0 (OR for top compared to bottom quartiles 1.61 [95%CI 1.18, 2.21], p = 0.003). Sensitivity analyses showed that point estimates for ORs were very similar regardless of CAC score threshold (CAC > 0, ≥ 20 and ≥ 100). Controlling for Apo A-I concentrations changes the inverse direction of relationship between high HDL-C concentration and a measure of pre-clinical atherosclerosis. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

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

    PubMed

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

    2009-08-01

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

  2. Association of High-Density Lipoprotein-Cholesterol Versus Apolipoprotein A-I With Risk of Coronary Heart Disease: The European Prospective Investigation Into Cancer-Norfolk Prospective Population Study, the Atherosclerosis Risk in Communities Study, and the Women's Health Study.

    PubMed

    van Capelleveen, Julian C; Bochem, Andrea E; Boekholdt, S Matthijs; Mora, Samia; Hoogeveen, Ron C; Ballantyne, Christie M; Ridker, Paul M; Sun, Wensheng; Barter, Philip J; Tall, Alan R; Zwinderman, Aeilko H; Kastelein, John J P; Wareham, Nick J; Khaw, Kay-Tee; Hovingh, G Kees

    2017-08-03

    The contribution of apolipoprotein A-I (apoA-I) to coronary heart disease (CHD) risk stratification over and above high-density lipoprotein cholesterol (HDL-C) is unclear. We studied the associations between plasma levels of HDL-C and apoA-I, either alone or combined, with risk of CHD events and cardiovascular risk factors among apparently healthy men and women. HDL-C and apoA-I levels were measured among 17 661 participants of the EPIC (European Prospective Investigation into Cancer)-Norfolk prospective population study. Hazard ratios for CHD events and distributions of risk factors were calculated by quartiles of HDL-C and apoA-I. Results were validated using data from the ARIC (Atherosclerosis Risk in Communities) and WHS (Women's Health Study) cohorts, comprising 15 494 and 27 552 individuals, respectively. In EPIC-Norfolk, both HDL-C and apoA-I quartiles were strongly and inversely associated with CHD risk. Within HDL-C quartiles, higher apoA-I levels were not associated with lower CHD risk; in fact, CHD risk was higher within some HDL-C quartiles. ApoA-I levels were associated with higher levels of CHD risk factors: higher body mass index, HbA1c, non-HDL-C, triglycerides, apolipoprotein B, systolic blood pressure, and C-reactive protein, within fixed HDL-C quartiles. In contrast, HDL-C levels were consistently inversely associated with overall CHD risk and CHD risk factors within apoA-I quartiles (P<0.001). These findings were validated in the ARIC and WHS cohorts. Our findings demonstrate that apoA-I levels do not offer predictive information over and above HDL-C. In fact, within some HDL-C quartiles, higher apoA-I levels were associated with higher risk of CHD events, possibly because of the unexpected higher prevalence of cardiovascular risk factors in association with higher apoA-I levels. URL: https://www.clinicaltrials.gov. Unique identifier: NCT00000479. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

  3. 30 CFR 57.22217 - Seals and stoppings (I-A, I-B, and I-C mines).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Seals and stoppings (I-A, I-B, and I-C mines... NONMETAL MINES Safety Standards for Methane in Metal and Nonmetal Mines Ventilation § 57.22217 Seals and stoppings (I-A, I-B, and I-C mines). All seals, and those stoppings that separate main intake from...

  4. 30 CFR 57.22217 - Seals and stoppings (I-A, I-B, and I-C mines).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Seals and stoppings (I-A, I-B, and I-C mines... NONMETAL MINES Safety Standards for Methane in Metal and Nonmetal Mines Ventilation § 57.22217 Seals and stoppings (I-A, I-B, and I-C mines). All seals, and those stoppings that separate main intake from...

  5. 30 CFR 57.22217 - Seals and stoppings (I-A, I-B, and I-C mines).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Seals and stoppings (I-A, I-B, and I-C mines... NONMETAL MINES Safety Standards for Methane in Metal and Nonmetal Mines Ventilation § 57.22217 Seals and stoppings (I-A, I-B, and I-C mines). All seals, and those stoppings that separate main intake from...

  6. 30 CFR 57.22217 - Seals and stoppings (I-A, I-B, and I-C mines).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Seals and stoppings (I-A, I-B, and I-C mines). 57.22217 Section 57.22217 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF... stoppings (I-A, I-B, and I-C mines). All seals, and those stoppings that separate main intake from...

  7. 30 CFR 57.22217 - Seals and stoppings (I-A, I-B, and I-C mines).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Seals and stoppings (I-A, I-B, and I-C mines). 57.22217 Section 57.22217 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF... stoppings (I-A, I-B, and I-C mines). All seals, and those stoppings that separate main intake from...

  8. Solution structure of discoidal high-density lipoprotein particles with a shortened apolipoprotein A-I.

    PubMed

    Bibow, Stefan; Polyhach, Yevhen; Eichmann, Cédric; Chi, Celestine N; Kowal, Julia; Albiez, Stefan; McLeod, Robert A; Stahlberg, Henning; Jeschke, Gunnar; Güntert, Peter; Riek, Roland

    2017-02-01

    High-density lipoprotein (HDL) particles are cholesterol and lipid transport containers. Mature HDL particles destined for the liver develop through the formation of intermediate discoidal HDL particles, which are the primary acceptors for cholesterol. Here we present the three-dimensional structure of reconstituted discoidal HDL (rdHDL) particles, using a shortened construct of human apolipoprotein A-I, determined from a combination of nuclear magnetic resonance (NMR), electron paramagnetic resonance (EPR) and transmission electron microscopy (TEM) data. The rdHDL particles feature a protein double belt surrounding a lipid bilayer patch in an antiparallel fashion. The integrity of this structure is maintained by up to 28 salt bridges and a zipper-like pattern of cation-π interactions between helices 4 and 6. To accommodate a hydrophobic interior, a gross 'right-to-right' rotation of the helices after lipidation is necessary. The structure reflects the complexity required for a shuttling container to hold a fluid lipid or cholesterol interior at a protein:lipid ratio of 1:50.

  9. Newly developed apolipoprotein A-I mimetic peptide promotes macrophage reverse cholesterol transport in vivo.

    PubMed

    Shimizu, Tomohiko; Tanigawa, Hiroyuki; Miura, Shin-ichiro; Kuwano, Takashi; Takata, Kohei; Suematsu, Yasunori; Imaizumi, Satoshi; Yahiro, Eiji; Zhang, Bo; Uehara, Yoshinari; Saku, Keijiro

    2015-08-01

    We elucidated the effect of newly developed Fukuoka Apolipoprotein A-I Mimetic Peptide (FAMP) on in vivo macrophage reverse cholesterol transport (RCT) and the underlying mechanisms. Cholesteryl ester transfer protein transgenic mice were divided into FAMP, and placebo control groups, and injected with FAMP or phosphate buffer saline intraperitoneally for 5 days. The FAMP group showed a significant decrease in plasma high-density lipoprotein cholesterol (HDL-C), and plasma from the FAMP group had an increased ability to promote ATP-binding cassette transporter A1 (ABCA1)-mediated cholesterol efflux from bone marrow macrophages ex vivo. Furthermore, mice were injected intraperitoneally with (3)H-cholesterol-labeled and cholesterol-loaded macrophages and monitored for the appearance of (3)H-tracer. The amount of (3)H-tracer excreted into feces over 48h in the FAMP group was significantly higher than that in the control group. (3)H-cholesterol ester (CE)-HDL was injected intravenously and (3)H-cholesterol in blood was counted. In the FAMP group, plasma (3)H-CE-HDL decreased rapidly, and treatment with FAMP markedly increased the fractional catabolic rate. The administration of FAMP promoted ABCA1-dependent efflux ex vivo, HDL turnover in vivo, and macrophage RCT in vivo despite reduced plasma HDL-C levels. FAMP might have atheroprotective potential. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  10. Apolipoprotein A-I lysine modification: effects on helical content, lipid binding and cholesterol acceptor activity.

    PubMed

    Brubaker, Gregory; Peng, Dao-Quan; Somerlot, Benjamin; Abdollahian, Davood J; Smith, Jonathan D

    2006-01-01

    We examined the role of the positively charged lysine residues in apoAI by chemical modification. Lysine modification by reductive methylation did not alter apoAI's net charge, secondary or tertiary structure as observed by circular dichroism and trytophan fluorescence, respectively, or have much impact on lipid binding or ABCA1-dependent cholesterol acceptor activity. Acetylation of lysine residues lowered the isoelectric point of apoAI, altered its secondary and tertiary structure, and led to a 40% decrease in cholesterol acceptor activity, while maintaining 93% of its lipid binding activity. Exhaustive lysine acetoacetylation lowered apoAI's isoelectric point, profoundly disrupted its secondary and tertiary structure, and led to 90% and 82% reductions in cholesterol acceptor and lipid binding activities, respectively. The dose-dependent acetoacetylation of an increasing proportion of apoAI lysine residues demonstrated that cholesterol acceptor activity was more sensitive to this modification than lipid binding activity, suggesting that apoAI lysine positive charges play an important role in ABCA1 mediated lipid efflux beyond the role needed to maintain alpha-helical content and lipid binding activity.

  11. 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

    PubMed Central

    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

  12. “Sticky” and “Promiscuous”—the Yin and Yang of Apolipoprotein A-I Termini in Discoidal High Density Lipoproteins: A Combined Computational-Experimental Approach†

    PubMed Central

    Jones, Martin K.; Gu, Feifei; Catte, Andrea; Li, Ling; Segrest, Jere P.

    2011-01-01

    Apolipoprotein (apo) A-I-containing lipoproteins in the form of high density lipoproteins (HDL) are inversely correlated with atherosclerosis. Because HDL is a soft form of condensed matter easily deformable by thermal fluctuations, the molecular mechanisms for HDL remodeling are not well understood. A promising approach to understanding HDL structure and dynamics is molecular dynamics (MD). In the present study, two computational strategies, MD simulated annealing (MDSA) and MD temperature-jump, were combined with experimental particle reconstitution to explore molecular mechanisms for phospholipid (PL)-rich HDL particle remodeling. The N-terminal domains of full length apoA-I were shown to be “sticky”, acting as a molecular latch largely driven by salt bridges, until, at a critical threshold of particle size, the associated domains released to expose extensive hydrocarbon regions of the PL to solvent. The “sticky” N-termini also associate with other apoA-I domains, perhaps being involved in N-terminal loops suggested by other laboratories. Alternatively, the overlapping helix 10 C-terminal domains of apoA-I were observed to be extremely mobile or “promiscuous”, transiently exposing limited hydrocarbon regions of PL. Based upon these models and reconstitution studies, we propose that separation of the N-terminal domains, as particles exceed a critical size, trigger fusion between particles or between particles and membranes, while the C-terminal domains of apoA-I drive the exchange of polar lipids down concentration gradients between particles. This hypothesis has significant biological relevance since lipid exchange and particle remodeling are critically important processes during metabolism of HDL particles at every step in the anti-atherogenic process of reverse cholesterol transport. PMID:21329368

  13. Proceedings of the XXII A.I.VE.LA. National Meeting

    NASA Astrophysics Data System (ADS)

    Primo Tomasini, Enrico

    2015-11-01

    A.I.VE.LA. - the Italian Association of Laser Velocimetry and non-invasive diagnostics - is a non-profit cultural association whose objective is to promote and support research in the field of non-contact or minimally invasive measurement techniques, particularly electromagnetic-based techniques and optical techniques. Through its Annual Meeting, AIVELA aims to create an active and stimulating forum where current research results and technical advances can be exchanged and the development of new systems for laboratory use, field testing and industrial application can be promoted. The techniques covered include Laser Doppler Anemometry - LDA, Phase Doppler Anemometry - PDA, Image Velocimetry - PIV, Flow visualization techniques, Spectroscopic measurement techniques (LIF, Raman, etc.), Laser Doppler Vibrometry - LDV, Speckle Pattern Interferometry - ESPI, Holographic techniques, Shearography, Digital Image Correlation - DIC, Moiré techniques, Structured light techniques, Infrared imaging, Photoelasticity, Image based measurement techniques, Ultrasonic sensing, Acoustic and Aeroacoustic measurements, etc. The first Annual Meeting was held back in October 1992 and since then there has been a large consensus among the research and scientific communities that the papers presented at the event are of a high scientific interest. The XXII AIVELA Annual Meeting was held at the Faculty of Engineering of University of Rome Tor Vergata on 15-16 December 2014 and was organised in collaboration with the International Master Courses in "Protection Against CBRNe Events". This volume contains a selection of the papers presented at the event. The detailed Programme of the Meeting can be found at: http://www.aivela.org/XXII_Convegno/index.html Trusting our Association and its initiatives will meet your interest, I wish to thank you in advance for your kind attention and hope to meet you soon at one of our events.

  14. Apolipoprotein A-I and platelet factor 4 are biomarkers for infliximab response in rheumatoid arthritis

    PubMed Central

    Trocmé, Candice; Marotte, Hubert; Baillet, Athan; Pallot-Prades, Béatrice; Garin, Jérome; Grange, Laurent; Miossec, Pierre; Tebib, Jacques; Berger, François; Nissen, Michael J.; Juvin, Robert; Morel, Françoise; Gaudin, Philippe

    2009-01-01

    Objectives The use of biologics such as infliximab has dramatically improved the treatment of rheumatoid arthritis (RA). However, factors predictive of therapeutic response need to be identified. A proteomic study was performed prior to infliximab therapy to identify a panel of candidate protein biomarkers of RA predictive of treatment response. Methods Plasma profiles of 60 RA patients (28 non-responders ACR 20 negative and 32 responders ACR 70 positive to infliximab) were studied by SELDI-TOF-MS technology on two types of arrays, an anion exchange array (SAX2) and a nickel affinity array (IMAC3-Ni). Biomarker characterization was carried out using classical biochemical methods (purification by ammonium sulfate precipitation or metal affinity chromatography) and identification by MALDI-TOF analysis. Results Two distinct protein profiles were observed on both arrays and several proteins were differentially expressed in both patient populations. Five proteins at 3.86, 7.77, 7.97, 8.14 and 74.07 kDa were overexpressed in the non-responder group, whereas one at 28 kDa was increased in the responder population (sensitivity > 56%, specificity > 77.5%). Moreover combination of several biomarkers improved both the sensitivity and specificity of the detection of patient response to over 97%. The 28 kDa protein was characterized as apolipoprotein A-I and the 7.77 kDa biomarker was identified as platelet factor 4. Conclusions We characterized six plasma biomarkers, enabling the detection of patient response to infliximab with high sensitivity and specificity. Apolipoprotein A-1 was predictive of a good response to infliximab, whereas platelet factor 4 was associated with non-responders. PMID:18664547

  15. Effects of dietary fat amount and saturation on the regulation of hepatic mRNA and plasma apolipoprotein A-I in rats.

    PubMed

    Calleja, L; Trallero, M C; Carrizosa, C; Méndez, M T; Palacios-Alaiz, E; Osada, J

    2000-09-01

    The effects of the amount of dietary fat and saturation together with cholesterol both on hepatic apolipoprotein A-I gene mRNA levels and on plasma levels of this apolipoprotein were studied in male rats. To achieve these goals, seven groups of male Wistar rats were established: control group (n=5) consuming chow diet; cholesterol group (n=4) fed on a chow diet containing 0.1% (w/w) cholesterol; coco group (n=5) fed on a chow diet containing 0.1% (w/w) cholesterol and 40% coconut oil; corn group (n=5) fed on a chow diet containing 0.1% (w/w) cholesterol and 40% corn oil; and three olive groups consuming a chow diet containing 0.1% (w/w) cholesterol and percentages of 5 (n=5), 10 (n=4) and 40% (n=5), respectively, of olive oil. Animals were kept on these diets for 2 months and then sacrificed for lipoprotein, apolipoprotein and hepatic mRNA analysis. Dietary cholesterol by itself was hypercholesterolemic when compared to chow diet, an effect that was mainly due to an increase in LDL-cholesterol. Corn oil had a hypocholesterolemic action, whether compared to chow or to cholesterol diet, due to a reduction in HDL-cholesterol as well as LDL-cholesterol. HDL-cholesterol levels of 40% olive oil diet were lower than those corresponding to coconut oil and higher than those found in corn oil diet. When compared to control or cholesterol diets, plasma apoA-I concentration appeared significantly increased in coconut and 40% olive oil diets. Coconut oil or corn oil diets did not induce any significant change in apoA-I mRNA compared to control or cholesterol diets. Compared to cholesterol diet, 40 and 10% olive oil diets induced a significant increase in the expression of this message. A positive and significant (r=0.97, P<0.01) correlation between plasma apolipoprotein A-I concentration and its hepatic mRNA, was observed when the amount of dietary olive oil was 40% (w/w). A significant negative (r=-0.97, P<0.01) correlation was found in the corn oil group and no significant

  16. Radial-immunodiffusion assay of human apolipoprotein A-I with use of two monoclonal antibodies combined.

    PubMed

    Marcovina, S; Di Cola, G; Catapano, A L

    1986-12-01

    We produced and characterized several monoclonal antibodies directed toward human plasma apolipoprotein A-I. Two of them, A-I-12 and A-I-57, individually precipitated purified or native high-density lipoprotein in agarose gel by double immunodiffusion. Because radial immunodiffusion performed with a single monoclonal antibody gave faint and diffuse rings of precipitation, we developed and optimized working conditions for using these two monoclonal antibodies combined to determine apolipoprotein A-I in human plasma. This combination gave easy-to-measure, clear, sharp rings, and linear and parallel standard curves for HDL3 (the primary standard) and a reference serum (the secondary standard). Moreover, no pretreatment of samples with dissociating agents or detergents is necessary. The assay was complete after overnight incubation, as compared with two to three days when polyclonal antisera were used. Apolipoprotein A-I concentrations as measured in 128 normolipidemic subjects and in 72 patients with various lipid disorders by the radial immunodiffusion technique with monoclonal antibodies (x) compared well (r = 0.882; y = 1.029x-0.036) with those measured by radial immunodiffusion with polyclonal antisera (y).

  17. Effects of the Iowa and Milano Mutations on Apolipoprotein A-I Structure and Dynamics Determined by Hydrogen Exchange and Mass Spectrometry

    PubMed Central

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

    2012-01-01

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

  18. Apolipoprotein A-I mimetic peptides inhibit expression and activity of hypoxia-inducible factor-1α in human ovarian cancer cell lines and a mouse ovarian cancer model.

    PubMed

    Gao, Feng; Chattopadhyay, Arnab; Navab, Mohamad; Grijalva, Victor; Su, Feng; Fogelman, Alan M; Reddy, Srinivasa T; Farias-Eisner, Robin

    2012-08-01

    Our previous results demonstrated that the apolipoprotein A-I (apoA-I) mimetic peptides L-4F and L-5F inhibit vascular endothelial growth factor production and tumor angiogenesis. The present study was designed to test whether apoA-I mimetic peptides inhibit the expression and activity of hypoxia-inducible factor-1α (HIF-1α), which plays a critical role in the production of angiogenic factors and angiogenesis. Immunohistochemistry staining was used to examine the expression of HIF-1α in tumor tissues. Immunoblotting, real-time polymerase chain reaction, immunofluorescence, and luciferase activity assays were used to determine the expression and activity of HIF-1α in human ovarian cancer cell lines. Immunohistochemistry staining demonstrated that L-4F treatment dramatically decreased HIF-1α expression in mouse ovarian tumor tissues. L-4F inhibited the expression and activity of HIF-1α induced by low oxygen concentration, cobalt chloride (CoCl(2), a hypoxia-mimic compound), lysophosphatidic acid, and insulin in two human ovarian cancer cell lines, OV2008 and CAOV-3. L-4F had no effect on the insulin-induced phosphorylation of Akt, but inhibited the activation of extracellular signal-regulated kinase and p70s6 kinase, leading to the inhibition of HIF-1α synthesis. Pretreatment with L-4F dramatically accelerated the proteasome-dependent protein degradation of HIF-1α in both insulin- and CoCl(2)-treated cells. The inhibitory effect of L-4F on HIF-1α expression is in part mediated by the reactive oxygen species-scavenging effect of L-4F. ApoA-I mimetic peptides inhibit the expression and activity of HIF-1α in both in vivo and in vitro models, suggesting the inhibition of HIF-1α may be a critical mechanism responsible for the suppression of tumor progression by apoA-I mimetic peptides.

  19. 22 CFR 204.23 - Payment to A.I.D. of excess amounts received by the lender of any assignee.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Payment to A.I.D. of excess amounts received by... Payment to A.I.D. of excess amounts received by the lender of any assignee. If the Lender or Assignee shall, as a result of A.I.D. paying compensation under this Guaranty, receive an excess payment, it...

  20. 22 CFR 204.23 - Payment to A.I.D. of excess amounts received by the lender of any assignee.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Payment to A.I.D. of excess amounts received by... Payment to A.I.D. of excess amounts received by the lender of any assignee. If the Lender or Assignee shall, as a result of A.I.D. paying compensation under this Guaranty, receive an excess payment, it...

  1. 22 CFR 204.23 - Payment to A.I.D. of excess amounts received by the lender of any assignee.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 22 Foreign Relations 1 2012-04-01 2012-04-01 false Payment to A.I.D. of excess amounts received by... Payment to A.I.D. of excess amounts received by the lender of any assignee. If the Lender or Assignee shall, as a result of A.I.D. paying compensation under this Guaranty, receive an excess payment, it...

  2. 22 CFR 204.23 - Payment to A.I.D. of excess amounts received by the lender of any assignee.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Payment to A.I.D. of excess amounts received by... Payment to A.I.D. of excess amounts received by the lender of any assignee. If the Lender or Assignee shall, as a result of A.I.D. paying compensation under this Guaranty, receive an excess payment, it...

  3. 22 CFR 204.23 - Payment to A.I.D. of excess amounts received by the lender of any assignee.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Payment to A.I.D. of excess amounts received by... Payment to A.I.D. of excess amounts received by the lender of any assignee. If the Lender or Assignee shall, as a result of A.I.D. paying compensation under this Guaranty, receive an excess payment, it...

  4. Piloting the Oregon A.I.M. Project: Measuring Progress for Program Evaluation and Accountability. Final Report, 1997-98.

    ERIC Educational Resources Information Center

    Greater Pittsburgh Literacy Council, PA.

    A pilot project was conducted to implement the Oregon A.I.M. (Assessment, Instruction, Mastery), a tutor program accountability system developed in Oregon, in 15 volunteer-based programs in Pennsylvania and to make recommendations on the usefulness of this system as a means of collecting and aggregating data on student progress for these and…

  5. 22 CFR 221.23 - Payment to A.I.D. of excess amounts received by a Noteholder.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Payment to A.I.D. of excess amounts received by a Noteholder. 221.23 Section 221.23 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT ISRAEL LOAN GUARANTEE STANDARD TERMS AND CONDITIONS Procedure for Obtaining Compensation § 221.23 Payment to...

  6. 22 CFR 221.23 - Payment to A.I.D. of excess amounts received by a Noteholder.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Payment to A.I.D. of excess amounts received by a Noteholder. 221.23 Section 221.23 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT ISRAEL LOAN GUARANTEE STANDARD TERMS AND CONDITIONS Procedure for Obtaining Compensation § 221.23 Payment to...

  7. 22 CFR 221.23 - Payment to A.I.D. of excess amounts received by a Noteholder.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Payment to A.I.D. of excess amounts received by a Noteholder. 221.23 Section 221.23 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT ISRAEL LOAN GUARANTEE STANDARD TERMS AND CONDITIONS Procedure for Obtaining Compensation § 221.23 Payment to...

  8. 22 CFR 221.23 - Payment to A.I.D. of excess amounts received by a Noteholder.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Payment to A.I.D. of excess amounts received by a Noteholder. 221.23 Section 221.23 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT ISRAEL LOAN GUARANTEE STANDARD TERMS AND CONDITIONS Procedure for Obtaining Compensation § 221.23 Payment to...

  9. 22 CFR 221.23 - Payment to A.I.D. of excess amounts received by a Noteholder.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 22 Foreign Relations 1 2012-04-01 2012-04-01 false Payment to A.I.D. of excess amounts received by a Noteholder. 221.23 Section 221.23 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT ISRAEL LOAN GUARANTEE STANDARD TERMS AND CONDITIONS Procedure for Obtaining Compensation § 221.23 Payment to...

  10. Properties of discoidal complexes of human apolipoprotein A-I with phosphatidylcholines containing various fatty acid chains.

    PubMed

    Zorich, N L; Kézdy, K E; Jonas, A

    1987-06-02

    In this study we demonstrate that apolipoprotein A-I determined the common size classes of discoidal particles formed with numerous phosphatidylcholines, and with ether analogs of phosphatidylcholines. We show furthermore, that the nature of the lipids dictates the distribution of particles among the different size classes. These experiments were performed with discoidal complexes containing various phospholipids (phosphatidylcholines with saturated and unsaturated fatty acid chains of different lengths and the ether analog of 1-palmitoyl-2-oleoylphosphatidylcholine), cholesterol, and human apolipoprotein A-I, prepared by the sodium cholate dialysis method, and fractionated by Bio-Gel A-5m gel-filtration chromatography. The complex preparations were analyzed in terms of their average composition, spectral properties of the apolipoprotein, and the dynamic behavior of the lipid domains. Nondenaturing gradient gel electrophoresis was used to analyze the size classes of particles present in the complex preparations. Starting with reaction mixtures containing around 100:1, phospholipid/apolipoprotein A-I molar ratios, complexes were isolated with molar ratios from 40:1 to 100:1. In most complexes apolipoprotein A-I had high levels of alpha-helical structure (65-77% alpha-helix), and tryptophan residues in a nonpolar environment. The lipid domains of complexes exhibited the dynamic behavior expected of the main phospholipid components. In the average size range from 90 to 100 A diameters, discrete particle classes with 80, 87, 102, 108, or 112 A Stokes diameters were observed for all the complexes containing different phospholipids. These discrete, recurring particle sizes are attributed to distinct apolipoprotein A-I conformations and variable lipid content.

  11. Extended-release niacin alters the metabolism of plasma apolipoprotein (apo) A-I- and apoB-containing lipoproteins

    USDA-ARS?s Scientific Manuscript database

    Extended-release niacin effectively lowers plasma TG levels and raises plasma HDL cholesterol levels, but the mechanisms responsible for these effects are unclear. We examined the effects of extended-release niacin (2 g/d) and extended-release niacin (2 g/d) plus lovastatin (40 mg/d), relative to pl...

  12. Reaction of discoidal complexes of apolipoprotein A-I and various phosphatidylcholines with lecithin cholesterol acyltransferase. Interfacial effects.

    PubMed

    Jonas, A; Zorich, N L; Kézdy, K E; Trick, W E

    1987-03-25

    Complexes of phospholipids-apolipoprotein A-I-cholesterol, containing various bulk phosphatidylcholines or a matrix of the ether analog of 1-palmitoyl 2-oleoyl phosphatidylcholine including test phosphatidylcholines were used as substrates for human lecithin-cholesterol acyltransferase. The enzymatic reaction rates for both series of complexes were determined as a function of temperature, particle concentration, neutral salt concentration, and the type of anion present in solution. The kinetic results support the hypothesis that phospholipids, in discoidal complexes, modulate the reaction rates by molecular effects at the active site, but also by interfacial effects on the interaction of the enzyme with the particles. The relevant interfacial parameters are the lipid packing at the interface and the structure of apolipoprotein A-I.

  13. Mosaic Interdigitated Structure in Nanoparticle-Templated Phospholipid Bilayer Supports Partial Lipidation of Apolipoprotein A-I.

    PubMed

    Sun, Wangqiang; Wu, Weiqiang; McMahon, Kaylin M; Rink, Jonathan S; Thaxton, C Shad

    2016-06-01

    Using gold nanoparticle-templated high-density lipoprotein-like particles as a model, the nanoparticle-templated phospholipid bilayer is studied from the bottom-up. Data support the phospholipids have a mosaic interdigitated structure. The discontinuous lipid milieu supports partial lipidation of apolipoprotein A-I, different from an ordinary phospholipid bilayer, suggesting that synergy between nanoparticle templates and bound phospholipid layers can modulate amphiphilic proteins for desired functions.

  14. Macrophage metalloproteinases degrade high-density-lipoprotein-associated apolipoprotein A-I at both the N- and C-termini.

    PubMed Central

    Eberini, Ivano; Calabresi, Laura; Wait, Robin; Tedeschi, Gabriella; Pirillo, Angela; Puglisi, Lina; Sirtori, Cesare R; Gianazza, Elisabetta

    2002-01-01

    Atheromatous plaques contain various cell types, including macrophages, endothelial cells and smooth-muscle cells. To investigate the possible interactions between secreted matrix metalloproteinases and high-density lipoprotein (HDL) components, we tested the above cell types by culturing them for 24 h. HDL(3) (HDL subfractions with average sizes of between 8.44 nm for HDL(3A) and 7.62 nm for HDL(3C)) were then incubated in their cell-free conditioned media. Proteolytic degradation of apolipoprotein A-I was observed with macrophages, but not with endothelial-cell- or muscle-cell-conditioned supernatant. Absence of calcium or addition of EDTA to incubation media prevented all proteolytic processes. The identified apolipoprotein A-I fragments had sizes of 26, 22, 14 and 9 kDa. Two-dimensional electrophoresis and MS resolved the 26 and the 22 kDa components and identified peptides resulting from both N- and C-terminal cleavage of apolipoprotein A-I. The higher abundance of C- than N-terminally cleaved peptides agrees with data in the literature for a fully structured alpha-helix around Tyr(18) compared with an unstructured region around Gly(185) and Gly(186). The flexibility in the latter region of apolipoprotein A-I may explain its susceptibility to proteolysis. In our experimental set-up, HDL(3C) was more extensively degraded than the other HDL(3) subclasses (HDL(3A) and HDL(3B)). Proteolytic fragments produced by metalloproteinase action were shown by gel filtration and electrophoresis to be neither associated with lipids nor self-associated. PMID:11879189

  15. A systematic review on the association between the Helicobacter pylori vacA i genotype and gastric disease.

    PubMed

    Liu, Xian; He, Bangshun; Cho, William C; Pan, Yuqin; Chen, Jie; Ying, Houqun; Wang, Feng; Lin, Kang; Peng, Hongxin; Wang, Shukui

    2016-05-01

    Helicobacter pylori (H. pylori) has been recognized as a cause of gastrointestinal diseases and progress of the pathology of gastrointestinal diseases is related to the genotype of H. pylori. Published studies have indicated that the H. pylori vacuolating cytotoxin gene A (vacA) i1/i2 genotype is associated with peptic ulcer disease (PUD) and gastric cancer (GC), but their conclusions are inconsistent. This study aimed to further assess the risk of vacA i gene for PUD and/or GC. A systematic search was conducted across three main electronic databases (PubMed, Web of Science, and CNKI). A meta-analysis was then performed on the pooled data of the published articles to estimate the overall influence of vacA i polymorphisms on PUD and/or GC by crude odds ratio (OR) with 95% confidence intervals (CI). The reliability of the results were confirmed by publication bias and sensitivity analysis of included studies. A total of 14 studies were selected according to the specific inclusion and exclusion criteria. The pooled results revealed that patients with GC were more vulnerable to infection by H. pylori i1 genotype (OR = 5.12; 95% CI: 2.66-9.85; P < 0.001) than those with chronic gastritis or nonulcer disease. Moreover, the results of subgroup analysis indicated that the i1 genotype of H. pylori was associated with an increased GC risk (OR = 10.89; 95% CI: 4.11-20.88; P < 0.001) in the Middle Asian population. The H. pylori vacA i1 genotype is associated with an increased GC risk, especially in the Middle Asian population.

  16. Differential Effects of apoE4 and Activation of ABCA1 on Brain and Plasma Lipoproteins

    PubMed Central

    Harats, Dror; Shaish, Aviv; Levkovitz, Hana; Bielicki, John K.; Johansson, Jan O.; Michaelson, Daniel M.

    2016-01-01

    Apolipoprotein E4 (apoE4), the leading genetic risk factor for Alzheimer's disease (AD), is less lipidated compared to the most common and AD-benign allele, apoE3. We have recently shown that i.p. injections of the ATP-binding cassette A1 (ABCA1) agonist peptide CS-6253 to apoE mice reverse the hypolipidation of apoE4 and the associated brain pathology and behavioral deficits. While in the brain apoE is the main cholesterol transporter, in the periphery apoE and apoA-I both serve as the major cholesterol transporters. We presently investigated the extent to which apoE genotype and CS-6253 treatment to apoE3 and apoE4-targeted replacement mice affects the plasma levels and lipid particle distribution of apoE, and those of plasma and brain apoA-I and apoJ. This revealed that plasma levels of apoE4 were lower and eluted faster following FPLC than plasma apoE3. Treatment with CS-6253 increased the levels of plasma apoE4 and rendered the elution profile of apoE4 similar to that of apoE3. Similarly, the levels of plasma apoA-I were lower in the apoE4 mice compared to apoE3 mice, and this effect was partially reversed by CS-6253. Conversely, the levels of apoA-I in the brain which were higher in the apoE4 mice, were unaffected by CS-6253. The plasma levels of apoJ were higher in apoE4 mice than apoE3 mice and this effect was abolished by CS-6253. Similar but less pronounced effects were obtained in the brain. In conclusion, these results suggest that apoE4 affects the levels of apoA-I and apoJ and that the anti-apoE4 beneficial effects of CS-6253 may be related to both central and peripheral mechanisms. PMID:27824936

  17. Effects of dietary maritime pine (Pinus pinaster)-seed oil on high-density lipoprotein levels and in vitro cholesterol efflux in mice expressing human apolipoprotein A-I.

    PubMed

    Asset, G; Leroy, A; Bauge, E; Wolff, R L; Fruchart, J C; Dallongeville, J

    2000-09-01

    Maritime pine (Pinus pinaster)-seed oil contains two Delta5 unsaturated polymethylene interrupted fatty acids (all cis-5,9, 12-18:3 and all cis-5,11,14-20:3 acids) one of which resembles eicosapentaenoic acid. The goal of the present study was to test whether maritime pine-seed oil consumption affects HDL and apolipoprotein (Apo) A-I levels as well as the ability of serum to promote efflux of cholesterol from cultured cells. To this end, wild type (WT) non-transgenic mice and transgenic mice expressing human ApoA-I (HuA-ITg) were fed on isoenergetic diet containing either 200 g maritime pine-seed oil/kg or 200 g lard/kg for 2 weeks. WT and HuA-ITg mice fed maritime pine-seed oil had lower cholesterol, HDL-cholesterol, LDL-cholesterol and HuA-ITg mice had lower human ApoA-I than those fed lard. The differences in cholesterol (P < 0.0001) and HDL-cholesterol (P < 0.003) levels between mice fed on the two diets were more pronounced in the HuA-ITg than in the WT mice. The ability of HuA-ITg serum to promote cholesterol efflux in cultured cells was greater (P < 0.008) than that of WT animals. However, the maritime pine-seed oil diet was associated with lower (P < 0.005) in vitro cholesterol efflux ability than the lard diet in both mice genotypes. This suggests a negative effect of the maritime pine-seed oil on reverse cholesterol transport. Cholesterol efflux was correlated with serum free or esterified cholesterol and phospholipid levels. The slope of the regression line was smaller in the HuA-ITg than in the WT mice indicating that overexpression of human ApoA-I reduces the negative impact of maritime pine-seed oil on cholesterol efflux. In conclusion, maritime pine-seed oil diet lowers HDL-cholesterol and diminishes in vitro cholesterol efflux. This potentially detrimental effect is attenuated by overexpression of human ApoA-I in mice.

  18. Apolipoprotein A-I mimetic peptide 4F rescues pulmonary hypertension by inducing microRNA-193-3p.

    PubMed

    Sharma, Salil; Umar, Soban; Potus, Francois; Iorga, Andrea; Wong, Gabriel; Meriwether, David; Breuils-Bonnet, Sandra; Mai, Denise; Navab, Kaveh; Ross, David; Navab, Mohamad; Provencher, Steeve; Fogelman, Alan M; Bonnet, Sébastien; Reddy, Srinivasa T; Eghbali, Mansoureh

    2014-08-26

    Pulmonary arterial hypertension is a chronic lung disease associated with severe pulmonary vascular changes. A pathogenic role of oxidized lipids such as hydroxyeicosatetraenoic and hydroxyoctadecadienoic acids is well established in vascular disease. Apolipoprotein A-I mimetic peptides, including 4F, have been reported to reduce levels of these oxidized lipids and improve vascular disease. However, the role of oxidized lipids in the progression of pulmonary arterial hypertension and the therapeutic action of 4F in pulmonary arterial hypertension are not well established. We studied 2 different rodent models of pulmonary hypertension (PH): a monocrotaline rat model and a hypoxia mouse model. Plasma levels of hydroxyeicosatetraenoic and hydroxyoctadecadienoic acids were significantly elevated in PH. 4F treatment reduced these levels and rescued preexisting PH in both models. MicroRNA analysis revealed that microRNA-193-3p (miR193) was significantly downregulated in the lung tissue and serum from both patients with pulmonary arterial hypertension and rodents with PH. In vivo miR193 overexpression in the lungs rescued preexisting PH and resulted in downregulation of lipoxygenases and insulin-like growth factor-1 receptor. 4F restored PH-induced miR193 expression via transcription factor retinoid X receptor α. These studies establish the importance of microRNAs as downstream effectors of an apolipoprotein A-I mimetic peptide in the rescue of PH and suggest that treatment with apolipoprotein A-I mimetic peptides or miR193 may have therapeutic value. © 2014 American Heart Association, Inc.

  19. Novel Pathways of Apolipoprotein A-I Metabolism in High-Density Lipoprotein of Different Sizes in Humans.

    PubMed

    Mendivil, Carlos O; Furtado, Jeremy; Morton, Allyson M; Wang, Liyun; Sacks, Frank M

    2016-01-01

    A prevailing concept is that high-density lipoprotein (HDL) is secreted into the systemic circulation as a small mainly discoidal particle, which expands progressively and becomes spherical by uptake and esterification of cellular cholesterol and then contracts by cholesterol ester delivery to the liver, a process known as reverse cholesterol transport, thought to be impaired in people with low HDL cholesterol (HDLc). This metabolic framework has not been established in humans. We studied the metabolism of apolipoprotein A-I in 4 standard HDL sizes by endogenous isotopic labeling in 6 overweight adults with low HDLc and in 6 adults with normal body weight with high plasma HDLc. Contrary to expectation, HDL was secreted into the circulation in its entire size distribution from very small to very large similarly in both groups. Very small (prebeta) HDL comprised only 8% of total apolipoprotein A-I secretion. Each HDL subfraction circulated mostly within its secreted size range for 1 to 4 days and then was cleared. Enlargement of very small and medium to large and very large HDL and generation of very small from medium HDL were minor metabolic pathways. Prebeta HDL was cleared slower, whereas medium, large, and very large HDL were cleared faster in the low HDLc group. A new model is proposed from these results in which HDL is metabolized in plasma mainly within several discrete, stable sizes across the common range of HDLc concentrations. © 2015 American Heart Association, Inc.

  20. Cytotoxicity and structure activity relationship studies of maplexins A-I, gallotannins from red maple (Acer rubrum).

    PubMed

    González-Sarrías, Antonio; Yuan, Tao; Seeram, Navindra P

    2012-05-01

    Maplexins A-I are a series of structurally related gallotannins recently isolated from the red maple (Acer rubrum) species. They differ in number and location of galloyl derivatives attached to 1,5-anhydro-glucitol. Here, maplexins A-I were evaluated for anticancer effects against human tumorigenic (colon, HCT-116; breast, MCF-7) and non-tumorigenic (colon, CCD-18Co) cell lines. The maplexins which contained two (maplexins C-D) or three (maplexins E-I) galloyl derivatives each, inhibited cancer cell growth while those with only one galloyl group (maplexins A-B) did not. Moreover, maplexins C-D showed greater antiproliferative effects than maplexins E-I (IC(50)=59.8-67.9 and 95.5-108.5 μM vs. 73.7-165.2 and 115.5-182.5 μM against HCT-116 and MCF-7 cells, respectively). Notably, the cancer cells were up to 2.5-fold more sensitive to the maplexins than the normal cells. In further mechanistic studies, maplexins C-D (at 75 μM concentrations) induced apoptosis and arrested cell cycle (in the S-phase) of the cancer cells. These results suggest that the number of galloyl groups attached to the 1,5-anhydro-glucitol moiety in these gallotannins are important for antiproliferative activity. Also, this is the first in vitro anticancer study of maplexins.

  1. Conformational analysis of apolipoprotein A-I and E-3 based on primary sequence and circular dichroism.

    PubMed Central

    Nolte, R T; Atkinson, D

    1992-01-01

    The primary and secondary structure of human plasma apolipoprotein A-I and apolipoprotein E-3 have been analyzed to further our understanding of the secondary and tertiary conformation of these proteins and the structure and function of plasma lipoprotein particles. The methods used to analyze the primary sequence of these proteins used computer programs: (a) to identify repeated patterns within these proteins on the basis of conservative substitutions and similarities within the physicochemical properties of each residue; (b) for local averaging, hydrophobic moment, and Fourier analysis of the physicochemical properties; and (c) for secondary structure prediction of each protein carried out using homology, statistical, and information theory based methods. Circular dichroism was used to study purified lipid-protein complexes of each protein and quantitate the secondary structure in a lipid environment. The data from these analyses were integrated into a single secondary structure prediction to derive a model of each protein. The sequence homology within apolipoproteins A-I, E-3, and A-IV is used to derive a consensus sequence for two 11 amino acid repeating sequences in this family of proteins. Images FIGURE 1 FIGURE 2 FIGURE 3 FIGURE 8 PMID:1477274

  2. 26 CFR 1.1092(b)-3T - Mixed straddles; straddle-by-straddle identification under section 1092(b)(2)(A)(i)(I) (temporary).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... identification under section 1092(b)(2)(A)(i)(I) (temporary). 1.1092(b)-3T Section 1.1092(b)-3T Internal Revenue... identification under section 1092(b)(2)(A)(i)(I) (temporary). (a) In general. Except as otherwise provided, a... constitute independent verification: (i) Separate account. Placement of one or more positions of a section...

  3. 49 CFR Appendix A-I to Part 541 - Lines With Antitheft Devices Which Are Exempted From the Parts-Marking Requirements of This...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 6 2012-10-01 2012-10-01 false Lines With Antitheft Devices Which Are Exempted From the Parts-Marking Requirements of This Standard Pursuant to 49 CFR Part 543 A Appendix A-I to Part.... 541, App. A-1 Appendix A-I to Part 541—Lines With Antitheft Devices Which Are Exempted From the Parts...

  4. 26 CFR 1.1092(b)-3T - Mixed straddles; straddle-by-straddle identification under section 1092(b)(2)(A)(i)(I) (temporary).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... identification under section 1092(b)(2)(A)(i)(I) (temporary). 1.1092(b)-3T Section 1.1092(b)-3T Internal Revenue... identification under section 1092(b)(2)(A)(i)(I) (temporary). (a) In general. Except as otherwise provided, a... constitute independent verification: (i) Separate account. Placement of one or more positions of a section...

  5. 26 CFR 1.1092(b)-3T - Mixed straddles; straddle-by-straddle identification under section 1092(b)(2)(A)(i)(I) (temporary).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... identification under section 1092(b)(2)(A)(i)(I) (temporary). 1.1092(b)-3T Section 1.1092(b)-3T Internal Revenue... identification under section 1092(b)(2)(A)(i)(I) (temporary). (a) In general. Except as otherwise provided, a... constitute independent verification: (i) Separate account. Placement of one or more positions of a section...

  6. 26 CFR 1.1092(b)-3T - Mixed straddles; straddle-by-straddle identification under section 1092(b)(2)(A)(i)(I) (temporary).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... identification under section 1092(b)(2)(A)(i)(I) (temporary). 1.1092(b)-3T Section 1.1092(b)-3T Internal Revenue... section 1092(b)(2)(A)(i)(I) (temporary). (a) In general. Except as otherwise provided, a taxpayer shall... constitute independent verification: (i) Separate account. Placement of one or more positions of a section...

  7. 49 CFR Appendix A-I to Part 541 - Lines With Antitheft Devices Which are Exempted From the Parts-Marking Requirements of This...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 6 2011-10-01 2011-10-01 false Lines With Antitheft Devices Which are Exempted From the Parts-Marking Requirements of This Standard Pursuant to 49 CFR Part 543 A Appendix A-I to Part.... 541, App. A-1 Appendix A-I to Part 541—Lines With Antitheft Devices Which are Exempted From the...

  8. Scapiformolactones A-I: germacrane sesquiterpenoids with an unusual Δ3-15,6-lactone moiety from Salvia scapiformis.

    PubMed

    Lai, Yongji; Xue, Yongbo; Zhang, Mengke; Zhang, Jinwen; Tang, Wei; Liu, Junjun; Lei, Liang; Yan, Juming; Luo, Zengwei; Zuo, Jianping; Li, Yan; Yao, Guangmin; Zhang, Yonghui

    2013-12-01

    Nine germacrane sesquiterpenoids with an unusual Δ(3)-15,6-lactone moiety, scapiformolactones A-I (1-9), and one known seco-germacrane sesquiterpenoid, 3,7,11-trimethyldodeca-l,6,9-triene-3,11-diol (10), were isolated from whole plants of Salvia scapiformis Hance. Their structures were elucidated by spectroscopic methods including HR-ESIMS, IR, UV, NMR, and CD, as well as by quantum mechanical calculations and chemical transformations. Structures of compounds 1-3 were also confirmed by single-crystal X-ray diffraction analysis. Six germacrane 6,15-diol derivatives (11-16) were obtained by chemical transformation. Compounds 1-9 and 11-16 were evaluated for their in vitro immunomodulatory effects on T and B cells, as well as their in vitro cytotoxicity against five human cancer cell lines, HL-60, SMMC-7721, A-549, MCF-7, and SW480.

  9. 30 CFR 57.22228 - Preshift examination (I-A, I-C, II-A, III, and V-A mines).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Preshift examination (I-A, I-C, II-A, III, and V-A mines). 57.22228 Section 57.22228 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... Preshift examination (I-A, I-C, II-A, III, and V-A mines). (a) Preshift examinations shall be conducted...

  10. 30 CFR 57.22222 - Ventilation materials (I-A, I-B, I-C, II-A, III, V-A, and V-B mines).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Ventilation materials (I-A, I-B, I-C, II-A, III, V-A, and V-B mines). 57.22222 Section 57.22222 Mineral Resources MINE SAFETY AND HEALTH....22222 Ventilation materials (I-A, I-B, I-C, II-A, III, V-A, and V-B mines). Brattice cloth and...

  11. 30 CFR 57.22228 - Preshift examination (I-A, I-C, II-A, III, and V-A mines).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Preshift examination (I-A, I-C, II-A, III, and V-A mines). 57.22228 Section 57.22228 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... Preshift examination (I-A, I-C, II-A, III, and V-A mines). (a) Preshift examinations shall be conducted...

  12. 30 CFR 57.22222 - Ventilation materials (I-A, I-B, I-C, II-A, III, V-A, and V-B mines).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Ventilation materials (I-A, I-B, I-C, II-A, III, V-A, and V-B mines). 57.22222 Section 57.22222 Mineral Resources MINE SAFETY AND HEALTH....22222 Ventilation materials (I-A, I-B, I-C, II-A, III, V-A, and V-B mines). Brattice cloth and...

  13. 30 CFR 57.22222 - Ventilation materials (I-A, I-B, I-C, II-A, III, V-A, and V-B mines).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Ventilation materials (I-A, I-B, I-C, II-A, III, V-A, and V-B mines). 57.22222 Section 57.22222 Mineral Resources MINE SAFETY AND HEALTH....22222 Ventilation materials (I-A, I-B, I-C, II-A, III, V-A, and V-B mines). Brattice cloth and...

  14. 30 CFR 57.22222 - Ventilation materials (I-A, I-B, I-C, II-A, III, V-A, and V-B mines).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Ventilation materials (I-A, I-B, I-C, II-A, III, V-A, and V-B mines). 57.22222 Section 57.22222 Mineral Resources MINE SAFETY AND HEALTH....22222 Ventilation materials (I-A, I-B, I-C, II-A, III, V-A, and V-B mines). Brattice cloth and...

  15. 30 CFR 57.22222 - Ventilation materials (I-A, I-B, I-C, II-A, III, V-A, and V-B mines).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Ventilation materials (I-A, I-B, I-C, II-A, III, V-A, and V-B mines). 57.22222 Section 57.22222 Mineral Resources MINE SAFETY AND HEALTH....22222 Ventilation materials (I-A, I-B, I-C, II-A, III, V-A, and V-B mines). Brattice cloth and...

  16. 30 CFR 57.22234 - Actions at 1.0 percent methane (I-A, I-B, III, V-A, and V-B mines).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Actions at 1.0 percent methane (I-A, I-B, III...-UNDERGROUND METAL AND NONMETAL MINES Safety Standards for Methane in Metal and Nonmetal Mines Ventilation § 57.22234 Actions at 1.0 percent methane (I-A, I-B, III, V-A, and V-B mines). (a) If methane reaches...

  17. 30 CFR 57.22234 - Actions at 1.0 percent methane (I-A, I-B, III, V-A, and V-B mines).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Actions at 1.0 percent methane (I-A, I-B, III...-UNDERGROUND METAL AND NONMETAL MINES Safety Standards for Methane in Metal and Nonmetal Mines Ventilation § 57.22234 Actions at 1.0 percent methane (I-A, I-B, III, V-A, and V-B mines). (a) If methane reaches...

  18. 30 CFR 57.22234 - Actions at 1.0 percent methane (I-A, I-B, III, V-A, and V-B mines).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Actions at 1.0 percent methane (I-A, I-B, III...-UNDERGROUND METAL AND NONMETAL MINES Safety Standards for Methane in Metal and Nonmetal Mines Ventilation § 57.22234 Actions at 1.0 percent methane (I-A, I-B, III, V-A, and V-B mines). (a) If methane reaches 1.0...

  19. 30 CFR 57.22234 - Actions at 1.0 percent methane (I-A, I-B, III, V-A, and V-B mines).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Actions at 1.0 percent methane (I-A, I-B, III...-UNDERGROUND METAL AND NONMETAL MINES Safety Standards for Methane in Metal and Nonmetal Mines Ventilation § 57.22234 Actions at 1.0 percent methane (I-A, I-B, III, V-A, and V-B mines). (a) If methane reaches 1.0...

  20. 30 CFR 57.22234 - Actions at 1.0 percent methane (I-A, I-B, III, V-A, and V-B mines).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Actions at 1.0 percent methane (I-A, I-B, III...-UNDERGROUND METAL AND NONMETAL MINES Safety Standards for Methane in Metal and Nonmetal Mines Ventilation § 57.22234 Actions at 1.0 percent methane (I-A, I-B, III, V-A, and V-B mines). (a) If methane reaches 1.0...

  1. The forgotten dispute: A.I. Oparin and H.J. Muller on the origin of life.

    PubMed

    Falk, Raphael; Lazcano, Antonio

    2012-01-01

    The debate between A.I. Oparin's heterotrophic proposal of the origin of life and H.J. Muller's suggestion that what may be considered a posteriori the beginning of life, was an autocatalytic, replicative gene, is analyzed. Although both recognized that what was needed was an interacting system contiguous in space and time, it is now rarely mentioned that this scientific confrontation went on for several decades against the background of intense ideological issues, political tensions, and scientific developments that include the rise and demise of Lysenkoism, on the one hand, and, on the other, the establishment of neoDarwinism and the birth of molecular biology. Whereas for Oparin life was the outcome of the step-wise slow process of precellular evolution in which membrane-bounded polymolecular systems played a key role, Muller argued that life started with the appearance of the first nucleic-acid (DNA) molecule in the primitive oceans. Oparin and Muller came from different scientific backgrounds and almost opposite intellectual traditions, so their common interest in the origin of life did nothing to assuage their opposing views, which as argued soon became part of the debates that took place within the framework of intense ideological confrontations.

  2. A phospholipid-apolipoproteinA-I nanoparticle containing Amphotericin B as a drug delivery platform with cell membrane protective properties

    PubMed Central

    Burgess, Braydon L.; Cavigiolio, Giorgio; Fannucchi, Michelle V.; Illek, Beate; Forte, Trudy M.; Oda, Michael N.

    2010-01-01

    Amphotericin B (AMB), a potent antifungal agent, has been employed as an inhalable therapy for pulmonary fungal infections. We recently described a novel nano-sized delivery vehicle composed of phospholipid (PL) and apolipoprotein A-I, NanoDisk (ND), to which we added AMB as a payload (ND-AMB). The goal of the present study was to evaluate whether ND-AMB, compared to other formulations, preserves lung cell integrity in vitro, as AMB can be toxic to mammalian cells and reduce lung function when inhaled. Epithelial integrity was assessed by measuring K+ ion flux across a model airway epithelium, Calu-3 cells. In this assay ND-AMB was at least 8-fold less disruptive than AMB/deoxycholate (DOC). Cell viability studies confirmed this observation. Unexpectedly, the ND vehicle restored the integrity of a membrane compromised by prior exposure to AMB. An alternative formulation of ND-AMB containing a high load of AMB per ND was not protective, suggesting that ND with a low ratio of AMB to PL can sequester additional AMB from membranes. ND-AMB also protected HepG2 cells from the cytotoxicity of AMB, as determined by cellular viability and lactate dehydrogenase (LDH) levels. This study suggests that ND-AMB may be safe for administration via inhalation and reveals a unique activity whereby ND-AMB protects lung epithelial membranes from AMB toxicity. PMID:20696226

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2015-01-01

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

  5. The influence of apoE-deficiency and LDL-receptor-deficiency on the HDL subpopulation profile in mice and in humans.

    PubMed

    Tani, Mariko; Matera, Robert; Horvath, Katalin V; Hasan, Tahira S; Schaefer, Ernst J; Asztalos, Bela F

    2014-03-01

    As apoE(-/-) and LDL-Receptor(-/-) mice are commonly used in atherosclerosis research; our objective was to point out the differences in HDL metabolism between mice and humans regarding the roles of apoE and LDLR. We examined HDL particles obtained from wild type (WT), LDLR(-/-), and apoE(-/-) mice, as well as from normal, homozygous familial hypercholesterolemic (FH), and apoE-deficient human subjects by 2-dimensional non-denaturing PAGE followed by immunoblot and image analysis. In WT mice, the majority of apoA-I was in large (9.0-12.0 nm), α-mobility HDL with trace amounts of apoA-I in small, preβ-1 HDL. In LDL(-/-) mice, both apoA-I- and apoE-containing HDL looked normal. About one-third of apoE was associated with large apoA-I-containing HDL (LpA-I:E) and two-thirds formed large HDL without apoA-I (LpE). In apoE(-/-) mice, apoA-I was detected in multiple, β-preβ-mobility, tightly-packed bands (7.0-13.0 nm) indicating that apoA-I in these animals was present only in poorly-lipidated, discoidal particles. Neither FH nor apoE-deficient humans showed significant alterations in apoA-I-containing HDL particles as compared to non-carriers. Our data indicate that apoE is necessary for the formation of spherical, lipidated HDL particles in mice, but not in humans, probably because mice lack CETP. Based on our data, we hypothesize that apoE(-/-) mice have little or no functional HDL, therefore results from apoE(-/-) mice cannot be extrapolated to humans without taking this significant difference into consideration. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  6. A <i>cis-regulatory module activating transcription in the suspensor contains five cis-regulatory elements

    SciTech Connect

    Henry, Kelli F.; Kawashima, Tomokazu; Goldberg, Robert B.

    2015-03-22

    Little is known about the molecular mechanisms by which the embryo proper and suspensor of plant embryos activate specific gene sets shortly after fertilization. We analyzed the upstream region of the Scarlet Runner Bean (Phaseolus coccineus) G564 gene in order to understand how genes are activated specifically in the suspensor during early embryo development. Previously, we showed that a 54-bp fragment of the G564 upstream region is sufficient for suspensor transcription and contains at least three required cis-regulatory sequences, including the 10-bp motif (5'-GAAAAGCGAA-3'), the 10 bp-like motif (5'-GAAAAACGAA-3'), and Region 2 motif (partial sequence 5'-TTGGT-3'). Here, we use site-directed mutagenesis experiments in transgenic tobacco globularstage embryos to identify two additional cis-regulatory elements within the 54-bp cis-regulatory module that are required for G564 suspensor transcription: the Fifth motif (5'-GAGTTA-3') and a third 10-bp-related sequence (5'-GAAAACCACA-3'). Further deletion of the 54-bp fragment revealed that a 47-bp fragment containing the five motifs (the 10-bp, 10-bp-like, 10-bp-related, Region 2 and Fifth motifs) is sufficient for suspensor transcription, and represents a <i>cis-regulatory module. A consensus sequence for each type of motif was determined by comparing motif sequences shown to activate suspensor transcription. Phylogenetic analyses suggest that the regulation of G564 is evolutionarily conserved. Lastly, a homologous cis-regulatory module was found upstream of the G564 ortholog in the Common Bean (Phaseolus vulgaris), indicating that the regulation of G564 is evolutionarily conserved in closely related bean species.

  7. Origin of Mercury’s double magnetopause: 3D hybrid simulation study with A.I.K.E.F.

    NASA Astrophysics Data System (ADS)

    Müller, Joachim; Simon, Sven; Wang, Yung-Ching; Motschmann, Uwe; Heyner, Daniel; Schüle, Josef; Ip, Wing-Huen; Kleindienst, Gero; Pringle, Gavin J.

    2012-03-01

    During the first and second Mercury flyby the MESSENGER spacecraft detected a dawn side double-current sheet inside the Hermean magnetosphere that was labeled the “double magnetopause” (Slavin, J.A. et al. [2008]. Science 321, 85). This double current sheet confines a region of decreased magnetic field that is referred to as Mercury’s “dayside boundary layer” (Anderson, M., Slavin, J., Horth, H. [2011]. Planet. Space Sci.). Up to the present day the double current sheet, the boundary layer and the key processes leading to their formation are not well understood. In order to advance the understanding of this region we have carried out self-consistent plasma simulations of the Hermean magnetosphere by means of the hybrid simulation code A.I.K.E.F. (Müller, J., Simon, S., Motschmann, U., Schüle, J., Glassmeier, K., Pringle, G.J. [2011]. Comput. Phys. Commun. 182, 946-966). Magnetic field and plasma results are in excellent agreement with the MESSENGER observations. In contrast to former speculations our results prove this double current sheet may exist in a pure solar wind hydrogen plasma, i.e. in the absence of any exospheric ions like sodium. Both currents are similar in orientation but the outer is stronger in intensity. While the outer current sheet can be considered the “classical” magnetopause, the inner current sheet between the magnetopause and Mercury’s surface reveals to be sustained by a diamagnetic current that originates from proton pressure gradients at Mercury’s inner magnetosphere. The pressure gradients in turn exist due to protons that are trapped on closed magnetic field lines and mirrored between north and south pole. Both, the dayside and nightside diamagnetic decreases that have been observed during the MESSENGER mission show to be direct consequences of this diamagnetic current that we label Mercury’s “boundary-layer-current“.

  8. Mercury being hit by a CME: A.I.K.E.F. Hybrid Plasma Simulation vs MESSENGER data

    NASA Astrophysics Data System (ADS)

    Exner, W.; Motschmann, U.; Heyner, D.; Glassmeier, K. H.; Shiota, D.; Kusano, K.; Shibayama, T.

    2016-12-01

    Being the innermost planet in our solar system, Mercury is embedded in an intensive and highly varying solar wind.We use the hybrid code A.I.K.E.F. (Adaptive Ion Kinetic Electron Fluid) which treats ions kinetically and electrons as a mass-less fluid to simulate the vicinity of Mercury's magnetosphere.Mercury has an intrinsic dipole field which is aligned with the rotation axis and has an offset of 0.2 RM to the north along the z-axis, whereas RM = 2440 Km is the Hermean radius.Combining in-situ MESSENGER-data and the SUSANOO-Fluidcode, which simulates the solar wind up to 2 AU, Mercury got hit by a coronal mass ejection (CME) on Nov 23rd 2011.Over 30 min, the magnetic field of the solar wind ranges from 3-100 nT, the plasma density varies from 30-250 particles centimeter-3, for which the Bow-Shock position changes rapidly and passes the MESSENGER spacecraft 4 times.Based on the results of our simulations, the Dungey-cycle time-scale is of roughly 1 minute, resulting in a nearly adiabatic correlation between the CME upstream input variations and the magnetospheric response.Therefore, several simulations have to be combined for sufficient agreement with MESSENGER-data.In comparison to the southern cusp, the distribution of electric current over the northern cusp reveal a steady input into the near surface exosphere of 250 μ {A}/{m}2, which could induce polar lights.With further examination of those currents with the upcoming ESA and JAXA BepiColombo mission, we provide data sets useful for planning its orbit and prepare for analysis of future CMEs and possible polar lights.

  9. The Polymorphism in the Promoter of HSP70 Gene Is Associated with Heat Tolerance of Two Congener Endemic Bay Scallops (Argopecten irradians irradians and A. i. concentricus)

    PubMed Central

    Yang, Chuanyan; Wang, Lingling; Wang, Jingjing; Jiang, Qiufen; Qiu, Limei; Zhang, Huan; Song, Linsheng

    2014-01-01

    Background The heat shock protein 70 (HSP70) is one kind of molecular chaperones, which plays a key role in protein metabolism under normal and stress conditions. Methodology In the present study, the mRNA expressions of HSP70 under normal physiological condition and after acute heat stress were investigated in gills of two bay scallop populations (Argopecten irradians irradians and A. i. concentricus). The heat resistant scallops A. i. concentricus showed significantly lower basal level and higher induction of HSP70 compared with that of the heat sensitive scallops A. i. irradians. The promoter sequence of HSP70 gene from bay scallop (AiHSP70) was cloned and the polymorphisms within this region were investigated to analyze their association with heat tolerance. Totally 11 single nucleotide polymorphisms (SNPs) were identified, and four of them (−967, −480, −408 and −83) were associated with heat tolerance after HWE analysis and association analysis. Based on the result of linkage disequilibrium analysis, the in vitro transcriptional activities of AiHSP70 promoters with different genotype were further determined, and the results showed that promoter from A. i. concentricus exhibited higher transcriptional activity than that from A. i. irradians (P<0.05). Conclusions The results provided insights into the molecular mechanisms underlying the thermal adaptation of different congener endemic bay scallops, which suggested that the increased heat tolerance of A. i. concentricus (compared with A. i. irradians) was associated with the higher expression of AiHSP70. Meanwhile, the −967 GG, −480 AA, −408 TT and −83 AG genotypes could be potential markers for scallop selection breeding with higher heat tolerance. PMID:25028964

  10. The apolipoprotein A-I mimetic peptide, D-4F, alleviates ox-LDL-induced oxidative stress and promotes endothelial repair through the eNOS/HO-1 pathway.

    PubMed

    Liu, Donghui; Ding, Zhenzhen; Wu, Mengzhang; Xu, Wenqi; Qian, Mingming; Du, Qian; Zhang, Le; Cui, Ye; Zheng, Jianlan; Chang, He; Huang, Caihua; Lin, Donghai; Wang, Yan

    2017-04-01

    Apolipoprotein A-I (apoA-I) mimetic peptide exerts many anti-atherogenic properties. However, the underlying mechanisms related to the endothelial protective effects remain elusive. In this study, the apoA-I mimetic peptide, D-4F, was used. Proliferation assay, wound healing, and transwell migration experiments showed that D-4F improved the impaired endothelial proliferation and migration resulting from ox-LDL. Endothelial adhesion molecules expression and monocyte adhesion assay demonstrated that D-4F inhibited endothelial inflammation. Caspase-3 activation and TUNEL stain indicated that D-4F reduced endothelial cell apoptosis. A pivotal anti-oxidant enzyme, heme oxygenase-1 (HO-1) was upregulated by D-4F. The Akt/AMPK/eNOS pathways were involved in the expression of HO-1 induced by D-4F. Moreover, the anti-oxidation, pro-proliferation, and pro-migration capacities of D-4F were diminished by the inhibitors of both eNOS (L-NAME) and HO-1 (Znpp). Additionally, downregulation of ATP-binding cassette transporter A1 (ABCA1) by siRNA abolished the activation of Akt, AMPK and eNOS, and reduced the upregulation of HO-1 triggered by D-4F. Furthermore, D-4F promoted the reendothelialization of injured intima in carotid artery injury model of C57BL/6J mice in vivo. In summary, these findings suggested that D-4F might be a powerful candidate in the protection of endothelial cells and the prevention of cardiovascular disease (CVD). Copyright © 2017. Published by Elsevier Ltd.

  11. The I.A.G. / A.I.G. SEDIBUD (Sediment Budgets in Cold Environments) Programme: Current and future activities

    NASA Astrophysics Data System (ADS)

    Beylich, Achim A.; Lamoureux, Scott; Decaulne, Armelle

    2013-04-01

    Projected climate change in cold regions is expected to alter melt season duration and intensity, along with the number of extreme rainfall events, total annual precipitation and the balance between snowfall and rainfall. Similarly, changes to the thermal balance are expected to reduce the extent of permafrost and seasonal ground frost and increase active layer depths. These effects will undoubtedly change surface environments in cold regions and alter the fluxes of sediments, nutrients and solutes, but the absence of quantitative data and coordinated geomorphic process monitoring and analysis to understand the sensitivity of the Earth surface environment is acute in cold climate environments. The International Association of Geomorphologists (I.A.G. / A.I.G. ) SEDIBUD (Sediment Budgets in Cold Environments) Programme was formed in 2005 to address this existing key knowledge gap. SEDIBUD currently has about 400 members worldwide and the Steering Committee of this international programme is composed of ten scientists from eight different countries: Achim A. Beylich (Chair) (Norway), Armelle Decaulne (Secretary) (France), John C. Dixon (USA), Scott F. Lamoureux (Vice-Chair) (Canada), John F. Orwin (Canada), Jan-Christoph Otto (Austria), Irina Overeem (USA), Thorsteinn Sæmundsson (Iceland), Jeff Warburton (UK) and Zbigniew Zwolinski (Poland). The central research question of this global group of scientists is to: Assess and model the contemporary sedimentary fluxes in cold climates, with emphasis on both particulate and dissolved components. Initially formed as European Science Foundation (ESF) Network SEDIFLUX (Sedimentary Source-to-Sink Fluxes in Cold Environments) (2004 - ), SEDIBUD has further expanded to a global group of researchers with field research sites located in polar and alpine regions in the northern and southern hemisphere. Research carried out at each of the close to 50 defined SEDIBUD key test sites varies by programme, logistics and available

  12. Texas A & I University Child Development Associate Training Materials: Book F. Competency F: Carrying Out Supplementary Responsibilities Related to the Children's Program.

    ERIC Educational Resources Information Center

    Texas A and I Univ., Kingsville.

    This volume, the last in a series of seven, contains the learning module on staff, which focuses on the last Child Development Associate (CDA) competency, in the performance based curriculum of the Texas A & I Bilingual Bicultural Child Development Associate Training Program. The curriculum was designed for training preschool teachers working…

  13. 77 FR 44677 - Quad/Graphics Inc., Including On-Site Leased Workers From Staff Mart and A.I.D., Jonesboro, AR...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-30

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF LABOR... of determination was published in the Federal Register on July 10, 2012 (77 FR 40641). At the request... magazines and catalogues. The company reports that workers leased from Staff Mart and A.I.D. were...

  14. The association between the apolipoprotein B/A-I ratio and coronary calcification may differ depending on kidney function in a healthy population.

    PubMed

    Kim, Seok-Hyung; Oh, Donghwan; Jung, Kwon Soo; Lee, Jung Eun; Kim, Hyunwook; Kim, Hyung Jong; Kim, Beom Seok; Park, Hyeong Cheon; Lee, Byoung Kwon; Choi, Hoon Young

    2017-01-01

    The apolipoprotein B/A-1 ratio has been reported to be one of the strongest risk predictors of cardiovascular events. However, its prognostic value for cardiovascular disease is still uncertain, especially in patients with chronic kidney disease. This study aimed to investigate whether the association between the apolipoprotein B/A-I ratio and coronary artery calcification differed according to kidney function in a healthy population. Of the data from 7,780 participants from the medical records database in Gangnam Severance Hospital from 2005 through 2016, a cross-sectional analysis included participants with an estimated glomerular filtration rate (eGFR) ≥ 60 mL/min/1.73 m2 determined based on the Chronic Kidney Disease -Epidemiology Collaboration equation (n  =  1,800). Mild renal insufficiency was defined as an eGFR of 60-90 mL/min/1.73 m2. Coronary artery calcification measured with computed tomography was defined as an above-zero score. Logistic regression analyses were used to determine the association between coronary calcification and the apolipoprotein B/A-I ratio according to eGFR by adjusting for the influence of confounders. The mean apolipoprotein B/A-I level was significantly higher in the participants with coronary artery calcification than in the participants without coronary artery calcification. The apolipoprotein B/A-I ratio was significantly different according to coronary artery calcification in the participants with normal kidney function, but in the participants with mild renal insufficiency, it was not different. After adjusting for age, male sex, systolic blood pressure, body mass index, current smoking status, and fasting plasma glucose, the apolipoprotein B/A-I ratio was significantly associated with an increased risk of coronary artery calcification in participants with normal kidney function (odds ratio = 2.411, p = 0.011), while in the participants with mild renal insufficiency, the apolipoprotein B/A-I ratio was not associated

  15. Use of a pain assessment and intervention notation (P.A.I.N.) tool in critical care nursing practice: nurses' evaluations.

    PubMed

    Puntillo, Kathleen A; Stannard, Daphne; Miaskowski, Christine; Kehrle, Karen; Gleeson, Sheila

    2002-01-01

    One of the barriers to effective pain management in critical care is the lack of systematic, comprehensive methods for assessing and treating pain. Use of a printed, standardized pain assessment and intervention tool can stimulate critical thinking and provide a framework for organizing pain assessment and management data. The objectives of this study were to do the following: (1) describe the Pain Assessment and Intervention Notation (P.A.I.N.) tool, (2) detail critical care nurse participants' evaluations of the P.A.I.N. intervention tool when used during care of postoperative patients in pain, and (3) evaluate the tool's usefulness in practice and education. Eleven intensive care unit (n = 7) and postanesthesia care unit (n = 4) nurses completed a questionnaire after they had used the pain tool in their clinical practices with 31 postoperative patients. Ten of the 11 nurses who returned an evaluation questionnaire found that the P.A.I.N. tool provided a consistent, systematic method of quantifying their assessment of patient pain and analgesic responsiveness. Five nurse participants believed that the P.A.I.N. tool improved their practice with regard to pain and sedation assessment. Three of the 11 nurses believed that the usefulness of the tool was limited because it was too detailed to be used routinely when caring for critically ill patients. All but 1 of the 11 nurses believed that the tool would have helped them earlier in their practice (ie, when they had less critical care nursing experience). The assessment and treatment of pain in critically ill patients are highly complex processes. This study identified many advantages of the use of a standardized, systematic approach to pain assessment and treatment by health professionals.

  16. Serum concentrations of cholesterol, apolipoprotein A-I and apolipoprotein B in a total of 1694 meat-eaters, fish-eaters, vegetarians and vegans.

    PubMed

    Bradbury, K E; Crowe, F L; Appleby, P N; Schmidt, J A; Travis, R C; Key, T J

    2014-02-01

    The objective of this study was to describe serum lipid concentrations, including apolipoproteins A-I and B, in different diet groups. A cross-sectional analysis of a sample of 424 meat-eaters, 425 fish-eaters, 423 vegetarians and 422 vegans, matched on sex and age, from the European Prospective Investigation into Cancer and Nutrition-Oxford cohort. Serum concentrations of total, and high-density lipoprotein (HDL) cholesterol, as well as apolipoproteins A-I and B were measured, and serum non-HDL cholesterol was calculated. Vegans had the lowest body mass index (BMI) and the highest and lowest intakes of polyunsaturated and saturated fat, respectively. After adjustment for age, alcohol and physical activity, compared with meat-eaters, fish-eaters and vegetarians, serum concentrations of total and non-HDL cholesterol and apolipoprotein B were significantly lower in vegans. Serum apolipoprotein A-I concentrations did not differ between the diet groups. In males, the mean serum total cholesterol concentration was 0.87 mmol/l lower in vegans than in meat-eaters; after further adjustment for BMI this difference was 0.76 mmol/l. In females, the difference in total cholesterol between these two groups was 0.6 mmol/l, and after further adjustment for BMI was 0.55 mmol/l. [corrected]. In this study, which included a large number of vegans, serum total cholesterol and apolipoprotein B concentrations were lower in vegans compared with meat-eaters, fish-eaters and vegetarians. A small proportion of the observed differences in serum lipid concentrations was explained by differences in BMI, but a large proportion is most likely due to diet.

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

    PubMed Central

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

    2013-01-01

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

  18. Impact of estimated HDL particle size via the ratio of HDL-C and apoprotein A-I on short-term prognosis of diabetic patients with stable coronary artery disease.

    PubMed

    Hong, Li-Feng; Yang, Bo; Luo, Song-Hui; Li, Jian-Jun

    2014-09-01

    Revascularization and statin therapy are routinely used in the management of stable coronary artery disease. However, it is unclear whether the estimated high-density lipoprotein (HDL) particle size (eHDL-S), the ratio of HDL cholesterol (HDL-C) to apoprotein A-I (apoA-I), is associated with the clinical outcomes of diabetic patients with stable coronary artery disease (CAD). We performed a prospective cohort study of 328 patients diagnosed with stable CAD by coronary angiography. Patients were followed up for a mean duration of 12 months. The patients were divided into three groups by the tertiles of eHDL-S: low eHDL-S (< 0.71, n = 118); intermediate eHDL-S (0.71-0.79, n = 111); and high eHDL-S (> 0.79, n = 99). The associations between the baseline eHDL-S and short-term outcomes were evaluated using the Kaplan-Meier method and Cox proportional regression. The low eHDL-S group had higher triglyceride, hemoglobin A1c, uric acid, and leukocyte count than the other groups. During the follow-up period, 47/328 patients experienced a pre-specified outcome. According to the Kaplan-Meier analysis, the incidence of pre-specified outcomes was lower in the high eHDL-S group (P = 0.04). However, eHDL-S was not independently associated with adverse outcomes in Cox proportional hazards regression (hazard ratio (HR): 0.23, 95% confidence interval (95% CI): 0.01-11.24, P = 0.493). Although the eHDL-S was associated with inflammatory biomarkers, it was not independently associated with the short-term prognosis of diabetic patients with stable CAD in the era of revascularization and potent statin therapy.

  19. Quantification by nano liquid chromatography parallel reaction monitoring mass spectrometry of human apolipoprotein A-I, apolipoprotein B, and hemoglobin A1c in dried blood spots.

    PubMed

    Henderson, Clark M; Bollinger, James G; Becker, Jessica O; Wallace, Jennifer M; Laha, Thomas J; MacCoss, Michael J; Hoofnagle, Andrew N

    2017-07-01

    Proteomic analysis of blood proteins in dried blood spots (DBS) is gaining attention as a possible replacement for measurements in plasma/serum collected by venipuncture. We aimed to develop and provisionally validate a nanoflow LC-PRM-MS method for clinical use. We used Skyline to develop a nanoflow LC-PRM-MS method to quantify glycated hemoglobin-β, apolipoprotein A-I, and apolipoprotein B in DBS. Precision, linearity, interferences, and stability were determined and the method was used to analyze samples from 36 human volunteers. The method was compared with clinically validated measurements in paired blood collected via venipuncture. The method was relatively precise for these proteins (10-11% CV) and linear across the normal concentration ranges of these proteins. Interference from high total serum protein concentration (>8 g/dL) was noted for apolipoprotein A-I and apolipoprotein B. Proteins in DBS were stable for 14 days at temperatures below 25°C and trypsinized samples were stable for 48 h at 7°C. There was moderate correlation with clinical methods (r = 0.783-0.858) and significant bias in individual samples. Although the method had adequate precision and linearity for a biomarker, the accuracy compared with clinically validated assays raises concerns regarding the use of DBS compared with venipuncture for clinical use. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Helicobacter pylori vacA i region polymorphism but not babA2 status associated to gastric cancer risk in northwestern Iran.

    PubMed

    Mottaghi, Batool; Safaralizadeh, Reza; Bonyadi, Morteza; Latifi-Navid, Saeid; Somi, Mohammad Hossein

    2016-02-01

    Helicobacter pylori-specific genotypes have been strongly associated with an increased risk of gastric cancer (GC). The aim of the present work was to study the associations of H. pylori virulence factors, vacA i region polymorphisms and babA2 status with GC risk in Azerbaijan patients. The DNA extracted from gastric biopsy specimens was used to access the babA2 and vacA genotypes. Overall, babA2 was present in 85.39 % (76/89) of H. pylori strains: 19 out of 24 (79.16 %) strains from GC, 16 out of 17 (94.14 %) strains from peptic ulcer disease (PUD) and 41 out of 48 (85.14 %) strains from chronic gastritis. No significant association was found between babA2 genotype and clinical outcomes (P > 0.05). i1 vacA polymorphism was detected in 46/89 (51.68 %) strains: in 21/24 (87.5 %), 6/17 (35.29 %) and 19/48 (39.58 %) patients with GC, PUD and chronic gastritis, respectively. i2 allele was detected in 43 (48.31 %) out of all 89 strains examined: 3 (14.28 %) of 24 strains from GC, 11 (64.71 %) of 17 from PUD, and 29 (60.42 %) of 48 strains from chronic gastritis. In this study, multiple linear regression analysis confirmed the strong association of i1 allele with GC (partial regression correlation 0.455 ± 0.101; P = 0). Results of multiple logistic regression analysis showed that vacA i1 genotype was significantly associated with GC compared with a control group (gastritis) (odds ratio 13.142, 95 % CI 3.116-55.430; P = 0). Findings from the measurement of H. pylori babA2 and vacA genotypes indicate a strong correlation between the vacA i1 allele and GC risk in the Azerbaijan area of Iran.

  1. Nardosinanols A-I and lemnafricanol, sesquiterpenes from several soft corals, Lemnalia sp., Paralemnalia clavata, Lemnalia africana, and Rhytisma fulvum fulvum.

    PubMed

    Bishara, Ashgan; Yeffet, Dina; Sisso, Mor; Shmul, Guy; Schleyer, Michael; Benayahu, Yehuda; Rudi, Amira; Kashman, Yoel

    2008-03-01

    Ten new sesquiterpenes, nardosinanols A-I ( 1- 9) and lemnafricanol ( 10), have been isolated from several Kenyan soft corals, i.e., from Lemnalia sp., Paralemnalia clavata, Lemnalia africana, and Rhytisma fulvum fulvum. The structures and relative stereochemistry of these compounds were elucidated by interpretation of MS, COSY ( (1)H- (1)H correlations), HSQC, HMBC, and NOESY NMR spectroscopic experiments and in the case of 5 also by chemical transformation to compounds 11 and 12. Nine compounds ( 1- 9) are based on the nardosinane skeleton ( 1- 6 are nardosinanes and 7- 9 nornardosinanes). Lemnafricanol ( 10) possesses a novel tricyclic skeleton. Compounds 3, 7, and 10 were found to be toxic to brine shrimp with LC 50 values of 4.0, 0.35, and 0.32 microM, respectively.

  2. Giffonins A-I, antioxidant cyclized diarylheptanoids from the leaves of the hazelnut tree (Corylus avellana), source of the Italian PGI product "Nocciola di Giffoni".

    PubMed

    Masullo, Milena; Cerulli, Antonietta; Olas, Beata; Pizza, Cosimo; Piacente, Sonia

    2015-01-23

    Eight new diaryl ether heptanoids, giffonins A-H (1-8), and one diaryl heptanoid, giffonin I (9), were isolated from the methanol extract of the leaves of Corylus avellana. Its hazelnut is the PGI product of the Campania region (Italy) known as "Nocciola di Giffoni". The MeOH extract of C. avellana leaves and giffonins A-I (1-9) were evaluated for their inhibitory effects on human plasma lipid peroxidation induced by H2O2 and H2O2/Fe(2+), by measuring the concentration of TBARS (thiobarbituric acid reactive substances). Compounds 4 and 8 at 10 μM reduced both H2O2- and H2O2/Fe(2+)-induced lipid peroxidation by more than 60% and 50%, respectively, indicating higher activity than curcumin used as reference compound.

  3. 30 CFR 57.22227 - Approved testing devices (I-A, I-B, I-C, II-A, II-B, III, IV, V-A, and V-B mines).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Approved testing devices (I-A, I-B, I-C, II-A... Ventilation § 57.22227 Approved testing devices (I-A, I-B, I-C, II-A, II-B, III, IV, V-A, and V-B mines). (a... be used in Subcategory I-C mines. (c)(1) If electrically......

  4. 30 CFR 57.22227 - Approved testing devices (I-A, I-B, I-C, II-A, II-B, III, IV, V-A, and V-B mines).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Approved testing devices (I-A, I-B, I-C, II-A... Ventilation § 57.22227 Approved testing devices (I-A, I-B, I-C, II-A, II-B, III, IV, V-A, and V-B mines). (a... be used in Subcategory I-C mines. (c)(1) If electrically......

  5. 30 CFR 57.22201 - Mechanical ventilation (I-A, I-B, I-C, II-A, II-B, III, IV, V-A, and V-B mines).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Mechanical ventilation (I-A, I-B, I-C, II-A, II...-UNDERGROUND METAL AND NONMETAL MINES Safety Standards for Methane in Metal and Nonmetal Mines Ventilation § 57.22201 Mechanical ventilation (I-A, I-B, I-C, II-A, II-B, III, IV, V-A, and V-B mines). All mines...

  6. Separation of recombinant apolipoprotein A-I(Milano) modified forms and aggregates in an industrial ion-exchange chromatography unit operation.

    PubMed

    Hunter, Alan K; Suda, Eric J; Herberg, John T; Thomas, Kristin E; Shell, Robert E; Gustafson, Mark E; Ho, Sa V

    2008-09-12

    We have shown how protein self-association impacts the ion-exchange separation of modified forms and aggregates for apolipoprotein A-I(Milano). It is well known that reversible self-association of a protein can lead to chromatographic band broadening, peak splitting, merging, fronting, and tailing. To mitigate these effects, urea or an organic modifier can be added to the chromatography buffers to shift the equilibrium distribution of the target molecule to the dissociated form. A first generation process that did not utilize urea resulted in low yield and low purity as it was not possible to separate protein aggregates. A second generation process run in the presence of 6M urea resulted in high purity and high yield, but throughput was limited due to low resin binding capacity when the protein was completely denatured. A third generation process achieved high purity, high yield, and high throughput by shifting the urea concentration during the process to continually operate in the optimal window for maximum loading and selectivity. Key to these systematic process improvements was the rational understanding of the interplay of urea concentration and ion-exchange chromatographic behavior. Results from pilot and industrial scale operations are presented, demonstrating the suitability of the techniques described in this work for the large scale manufacture of recombinant therapeutic proteins.

  7. Molecular diagnostic assays based on cpn60 UT sequences reveal the geographic distribution of subgroup 16SrXIII-(A/I)I phytoplasma in Mexico.

    PubMed

    Pérez-López, Edel; Rodríguez-Martínez, Douglas; Olivier, Chrystel Y; Luna-Rodríguez, Mauricio; Dumonceaux, Tim J

    2017-04-19

    Geographically diverse samples from strawberry exhibiting symptoms of Strawberry Green Petal (SbGP), periwinkle plants with virescence, and blackberry, blueberry, and raspberry plants displaying yellowing and inedible fruits, were assayed for the presence of phytoplasma DNA. PCR targeting the 16S rRNA-encoding gene and chaperonin-60 (cpn60) showed that the plants were infected with phytoplasma subgroup16SrXIII-(A/I)I (SbGP/MPV). To examine the geographic distribution of this pathogen in Mexico, we designed an array of cpn60-targeted molecular diagnostic assays for SbGP/MPV phytoplasma. A fluorescent microsphere hybridization assay was designed that was capable of detecting SbGP/MPV phytoplasma in infected plant tissues, successfully differentiating it from other known phytoplasma cpn60 UT sequences, while identifying a double infection with SbGP/MPV and aster yellows (16SrI) phytoplasma. Two quantitative assays, quantitative real-time PCR (qRT-PCR) and droplet digital PCR (ddPCR), gave similar results in infected samples. Finally, a loop-mediated isothermal amplification (LAMP) assay provided rapid detection of SbGP/MPV phytoplasma DNA. Application of these assays revealed that SbGP/MPV phytoplasma is widely distributed in Central Mexico, with positive samples identified from eleven localities within three states separated by hundreds of kilometres. These results also provide tools for determining the presence and geographic distribution of this pathogen in plant and insect samples in other localities.

  8. Detection and identification of the heterogeneous novel subgroup 16SrXIII-(A/I)I phytoplasma associated with strawberry green petal disease and Mexican periwinkle virescence.

    PubMed

    Pérez-López, Edel; Dumonceaux, Tim J

    2016-11-01

    Phytoplasmas (species of the genus 'CandidatusPhytoplasma') are insect-vectored phytopathogenic bacteria associated with economically and ecologically important crop diseases. Strawberry production represents an important part of agricultural activity in Mexico and elsewhere, and infection of plants with phytoplasma renders the fruit inedible by altering plant development, resulting in virescence and phyllody. In this study we examined samples taken from four strawberry plants showing symptoms associated with strawberry green petal disease and from two periwinkle plants showing virescence, sampled in different areas of Mexico. Analysis of the 16S rRNA-encoding sequences showed that the plants were infected with a phytoplasma previously identified as Mexican periwinkle virescence (MPV; 16SrXIII). Examination of bacterial sequences from these samples revealed that two distinct 16S rRNA gene sequences were present in each sample along with a single chaperonin-60 (cpn60) sequence and a single rpoB sequence, suggesting that this strain displays 16S rRNA gene sequence heterogeneity. Two distinct rrn operons, identified with subgroup 16SrXIII-A and the newly described subgroup 16SrXIII-I, were identified from the six samples analyzed, delineating the novel subgroup 16SrXIII-(A/I)I, following the nomenclature proposed for heterogeneous subgroups.

  9. International Federation of Clinical Chemistry standardization project for measurements of apolipoproteins A-I and B. IV. Comparability of apolipoprotein B values by use of International Reference Material.

    PubMed

    Marcovina, S M; Albers, J J; Kennedy, H; Mei, J V; Henderson, L O; Hannon, W H

    1994-04-01

    We performed temporal and thermal stability studies on SP3-07, a liquid-stabilized reference material for apolipoprotein (apo) B, selected during the previous phase of the International Federation of Clinical Chemistry project on standardization of apolipoprotein measurements. Results indicate that SP3-07 stored at -70 degrees C has the long-term stability required for a reference material. We assigned an accuracy-based apo B value of 1.22 g/L to SP3-07, using a nephelometric method that was calibrated with freshly isolated low-density lipoprotein for which the apo B mass value was determined by a standardized sodium dodecyl sulfate-Lowry procedure. Using a common protocol, the study participants transferred the assigned mass value from SP3-07 to the individual calibrators of the analytical systems and measured the apo B concentration of 20 fresh-frozen samples obtained from individual donors and covering a clinically relevant range of apo B values. The among-laboratory CV on these samples, analyzed by 25 analytical systems, ranged from 3.1% to 6.7%. These results demonstrate the lack of matrix effects of SP3-07 and its ability to provide accurate and comparable apo B values in a variety of immunochemical methods. On the basis of the outcome of these studies, the World Health Organization has endorsed SP3-07 as the International Reference Material for Apolipoprotein B.

  10. Full-length apolipoprotein E protects against the neurotoxicity of an apoE-related peptide

    PubMed Central

    Crutcher, K.A.; Lilley, H.N.; Anthony, S. R.; Zhou, W.; Narayanaswami, V.

    2009-01-01

    Apolipoprotein E was found to protect against the neurotoxic effects of a dimeric peptide derived from the receptor-binding region of this protein (residues 141–149). Both apoE3 and apoE4 conferred protection but the major N-terminal fragment of each isoform did not. Nor was significant protection provided by bovine serum albumin or apoA-I. Full-length apoE3 and apoE4 also inhibited the uptake of a fluorescent-labeled derivative of the peptide, suggesting that the mechanism of inhibition might involve competition for cell surface receptors/proteoglycans that mediate endocytosis and/or signaling pathways. These results might bear on the question of the role of apoE in neuronal degeneration, such as occurs in Alzheimer’s disease where apoE4 confers a significantly greater risk of pathology. PMID:19836363

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

    PubMed

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

    2016-08-01

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

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

    PubMed Central

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

    2016-01-01

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

  13. Gravity-dependent differentiation and root coils in Arabidopsis thaliana wild type and phospholipase-A-I knockdown mutant grown on the International Space Station.

    PubMed

    Scherer, G F E; Pietrzyk, P

    2014-01-01

    Arabidopsis roots on 45° tilted agar in 1-g grow in wave-like figures. In addition to waves, formation of root coils is observed in several mutants compromised in gravitropism and/or auxin transport. The knockdown mutant ppla-I-1 of patatin-related phospholipase-A-I is delayed in root gravitropism and forms increased numbers of root coils. Three known factors contribute to waving: circumnutation, gravisensing and negative thigmotropism. In microgravity, deprivation of wild type (WT) and mutant roots of gravisensing and thigmotropism and circumnutation (known to slow down in microgravity, and could potentially lead to fewer waves or increased coiling in both WT and mutant). To resolve this, mutant ppla-I-1 and WT were grown in the BIOLAB facility in the International Space Station. In 1-g, roots of both types only showed waving. In the first experiment in microgravity, the mutant after 9 days formed far more coils than in 1-g but the WT also formed several coils. After 24 days in microgravity, in both types the coils were numerous with slightly more in the mutant. In the second experiment, after 9 days in microgravity only the mutant formed coils and the WT grew arcuated roots. Cell file rotation (CFR) on the mutant root surface in microgravity decreased in comparison to WT, and thus was not important for coiling. Several additional developmental responses (hypocotyl elongation, lateral root formation, cotyledon expansion) were found to be gravity-influenced. We tentatively discuss these in the context of disturbances in auxin transport, which are known to decrease through lack of gravity. © 2013 German Botanical Society and The Royal Botanical Society of the Netherlands.

  14. The I.A.G. / A.I.G. SEDIBUD Book Project: Source-to-Sink Fluxes in Undisturbed Cold Environments

    NASA Astrophysics Data System (ADS)

    Beylich, Achim A.; Dixon, John C.; Zwolinski, Zbigniew

    2015-04-01

    The currently prepared SEDIBUD Book on "Source-to-Sink Fluxes in Undisturbed Cold Environments" (edited by Achim A. Beylich, John C. Dixon and Zbigniew Zwolinski and published by Cambridge University Press) is summarizing and synthesizing the achievements of the International Association of Geomorphologists` (I.A.G./A.I.G.) Working Group SEDIBUD (Sediment Budgets in Cold Environments), which has been active since 2005 (http://www.geomorph.org/wg/wgsb.html). Amplified climate change and ecological sensitivity of largely undisturbed polar and high-altitude cold climate environments have been highlighted as key global environmental issues. The effects of projected climate change will change surface environments in cold regions and will alter the fluxes of sediments, nutrients and solutes, but the absence of quantitative data and coordinated geomorphic process monitoring and analysis to understand the sensitivity of the Earth surface environment in these largely undisturbed environments is acute. Our book addresses this existing key knowledge gap. The applied approach of integrating comparable and longer-term field datasets on contemporary solute and sedimentary fluxes from a number of different defined cold climate catchment geosystems for better understanding (i) the environmental drivers and rates of contemporary denudational surface processes and (ii) possible effects of projected climate change in cold regions is unique in the field of geomorphology. Largely undisturbed cold climate environments can provide baseline data for modeling the effects of environmental change. The book synthesizes work carried out by numerous SEDIBUD Members over the last decade in numerous cold climate catchment geosystems worldwide. For reaching a global cover of different cold climate environments the book is - after providing an introduction part and a basic part on climate change in cold environments and general implications for solute and sedimentary fluxes - dealing in different

  15. 30 CFR 57.22201 - Mechanical ventilation (I-A, I-B, I-C, II-A, II-B, III, IV, V-A, and V-B mines).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Mechanical ventilation (I-A, I-B, I-C, II-A, II-B, III, IV, V-A, and V-B mines). 57.22201 Section 57.22201 Mineral Resources MINE SAFETY AND HEALTH....22201 Mechanical ventilation (I-A, I-B, I-C, II-A, II-B, III, IV, V-A, and V-B mines). All mines shall...

  16. 30 CFR 57.22201 - Mechanical ventilation (I-A, I-B, I-C, II-A, II-B, III, IV, V-A, and V-B mines).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Mechanical ventilation (I-A, I-B, I-C, II-A, II-B, III, IV, V-A, and V-B mines). 57.22201 Section 57.22201 Mineral Resources MINE SAFETY AND HEALTH....22201 Mechanical ventilation (I-A, I-B, I-C, II-A, II-B, III, IV, V-A, and V-B mines). All mines shall...