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Sample records for lipoprotein receptor-related protein-10

  1. The low-density lipoprotein receptor-related protein 10 is a negative regulator of the canonical Wnt/β-catenin signaling pathway

    International Nuclear Information System (INIS)

    Jeong, Young-Hee; Sekiya, Manami; Hirata, Michiko; Ye, Mingjuan; Yamagishi, Azumi; Lee, Sang-Mi; Kang, Man-Jong; Hosoda, Akemi; Fukumura, Tomoe; Kim, Dong-Ho; Saeki, Shigeru

    2010-01-01

    Wnt signaling pathways play fundamental roles in the differentiation, proliferation and functions of many cells as well as developmental, growth, and homeostatic processes in animals. Low-density lipoprotein receptor (LDLR)-related protein (LRP) 5 and LRP6 serve as coreceptors of Wnt proteins together with Frizzled receptors, triggering activation of canonical Wnt/β-catenin signaling. Here, we found that LRP10, a new member of the LDLR gene family, inhibits the canonical Wnt/β-catenin signaling pathway. The β-catenin/T cell factor (TCF) transcriptional activity in HEK293 cells was activated by transfection with Wnt3a or LRP6, which was then inhibited by co-transfection with LRP10. Deletion of the extracellular domain of LRP10 negated its inhibitory effect. The inhibitory effect of LRP10 was consistently conserved in HEK293 cells even when GSK3β phosphorylation was inhibited by incubation with lithium chloride and co-transfection with constitutively active S33Y-mutated β-catenin. Nuclear β-catenin accumulation was unaffected by LRP10. The present studies suggest that LRP10 may interfere with the formation of the β-catenin/TCF complex and/or its binding to target DNA in the nucleus, and that the extracellular domain of LRP10 is critical for inhibition of the canonical Wnt/β-catenin signaling pathway.

  2. The LDL Receptor-Related Protein 1: At the Crossroads of Lipoprotein Metabolism and Insulin Signaling

    Directory of Open Access Journals (Sweden)

    Dianaly T. Au

    2017-01-01

    Full Text Available The metabolic syndrome is an escalating worldwide public health concern. Defined by a combination of physiological, metabolic, and biochemical factors, the metabolic syndrome is used as a clinical guideline to identify individuals with a higher risk for type 2 diabetes and cardiovascular disease. Although risk factors for type 2 diabetes and cardiovascular disease have been known for decades, the molecular mechanisms involved in the pathophysiology of these diseases and their interrelationship remain unclear. The LDL receptor-related protein 1 (LRP1 is a large endocytic and signaling receptor that is widely expressed in several tissues. As a member of the LDL receptor family, LRP1 is involved in the clearance of chylomicron remnants from the circulation and has been demonstrated to be atheroprotective. Recently, studies have shown that LRP1 is involved in insulin receptor trafficking and regulation and glucose metabolism. This review summarizes the role of tissue-specific LRP1 in insulin signaling and its potential role as a link between lipoprotein and glucose metabolism in diabetes.

  3. Neuronal low-density lipoprotein receptor-related protein 1 binds and endocytoses prion fibrils via receptor cluster 4

    DEFF Research Database (Denmark)

    Jen, Angela; Parkyn, Celia J; Mootoosamy, Roy C

    2010-01-01

    For infectious prion protein (designated PrP(Sc)) to act as a template to convert normal cellular protein (PrP(C)) to its distinctive pathogenic conformation, the two forms of prion protein (PrP) must interact closely. The neuronal receptor that rapidly endocytoses PrP(C) is the low......-density lipoprotein receptor-related protein 1 (LRP1). We show here that on sensory neurons LRP1 is also the receptor that binds and rapidly endocytoses smaller oligomeric forms of infectious prion fibrils, and recombinant PrP fibrils. Although LRP1 binds two molecules of most ligands independently to its receptor...... both prion and LRP1 biology....

  4. The low-density lipoprotein receptor-related protein 1 and amyloid-β clearance in Alzheimer’s disease

    Directory of Open Access Journals (Sweden)

    Takahisa eKanekiyo

    2014-05-01

    Full Text Available Accumulation and aggregation of amyloid-β (Aβ peptides in the brain trigger the development of progressive neurodegeneration and dementia associated with Alzheimer’s disease (AD. Perturbation in Aβ clearance, rather than Aβ production, is likely the cause of sporadic, late-onset AD, which accounts for the majority of AD cases. Since cellular uptake and subsequent degradation constitute a major Aβ clearance pathway, the receptor-mediated endocytosis of Aβ has been intensely investigated. Among Aβ receptors, the low-density lipoprotein receptor-related protein 1 (LRP1 is one of the most studied receptors. LRP1 is a large endocytic receptor for more than 40 ligands, including apolipoprotein E (apoE, α2-macroglobulin and Aβ. Emerging in vitro and in vivo evidence demonstrates that LRP1 is critically involved in brain Aβ clearance. LRP1 is highly expressed in a variety of cell types in the brain including neurons, vascular cells and glial cells, where LRP1 functions to maintain brain homeostasis and control Aβ metabolism. LRP1-mediated endocytosis regulates cellular Aβ uptake by binding to Aβ either directly or indirectly through its co-receptors or ligands. Furthermore, LRP1 regulates several signaling pathways, which also likely influences Aβ endocytic pathways. In this review, we discuss how LRP1 regulates the brain Aβ clearance and how this unique endocytic receptor participates in AD pathogenesis. Understanding of the mechanisms underlying LRP1-mediated Aβ clearance should enable the rational design of novel diagnostic and therapeutic strategies for AD.

  5. Low-density Lipoprotein Receptor-related Protein-1 (LRP1) Mediates Autophagy and Apoptosis Caused by Helicobacter pylori VacA*

    OpenAIRE

    Yahiro, Kinnosuke; Satoh, Mamoru; Nakano, Masayuki; Hisatsune, Junzo; Isomoto, Hajime; Sap, Jan; Suzuki, Hidekazu; Nomura, Fumio; Noda, Masatoshi; Moss, Joel; Hirayama, Toshiya

    2012-01-01

    In Helicobacter pylori infection, vacuolating cytotoxin (VacA)-induced mitochondrial damage leading to apoptosis is believed to be a major cause of cell death. It has also been proposed that VacA-induced autophagy serves as a host mechanism to limit toxin-induced cellular damage. Apoptosis and autophagy are two dynamic and opposing processes that must be balanced to regulate cell death and survival. Here we identify the low-density lipoprotein receptor-related protein-1 (LRP1) as the VacA rec...

  6. Low density lipoprotein receptor-related protein 1 expression correlates with cholesteryl ester accumulation in the myocardium of ischemic cardiomyopathy patients

    Directory of Open Access Journals (Sweden)

    Cal Roi

    2012-08-01

    Full Text Available Abstract Our hypothesis was that overexpression of certain lipoprotein receptors might be related to lipid accumulation in the human ischemic myocardium. Intramyocardial lipid overload contributes to contractile dysfunction and arrhythmias in cardiomyopathy. Thus, the purpose of this study was to assess the effect of hypercholesterolemic LDL and hypertrigliceridemic VLDL dose on LRP1 expression in cardiomyocytes, as well as the potential correlation between LRP1 expression and neutral lipid accumulation in the left ventricle tissue from ischemic cardiomyopathy patients. Cell culture experiments include control and LRP1-deficient cardiomyocytes exposed to lipoproteins under normoxic and hypoxic conditions. Explanted hearts from 18 ICM patients and eight non-diseased hearts (CNT were included. Low density lipoprotein receptor-related protein 1 (LRP1, very low density lipoprotein receptor (VLDLR and low density lipoprotein receptor (LDLR expression was analyzed by real time PCR and Western blotting. Cholesteryl ester (CE, triglyceride (TG and free cholesterol (FC content was assess by thin layer chromatography following lipid extraction. Western blotting experiments showed that protein levels of LRP1, VLDLR and HIF-1α were significantly upregulated in ischemic hearts. Immunohistochemistry and confocal microscopy analysis showed that LRP1 and HIF-1α were upregulated in cardiomyocytes of ICM patients. In vitro studies showed that VLDL, LDL and hypoxia exerted an upregulatory effect on LRP1 expression and that LRP1 played a major role in cholesteryl ester accumulation from lipoproteins in cardiomyocytes. Myocardial CE accumulation strongly correlated with LRP1 levels in ischemic hearts. Taken together, our results suggest that LRP1 upregulation is key for myocardial cholesterol ester accumulation in ischemic human hearts and that LRP1 may be a target to prevent the deleterious effects of myocardial cholesterol accumulation in ischemic cardiomyopathy.

  7. The multiligand α2-macroglobulin receptor/low density lipoprotein receptor-related protein

    DEFF Research Database (Denmark)

    Gliemann, Jørgen; Nykjær, Anders; Petersen, Claus Munck

    1994-01-01

    The fusion of separate lines of research has greatly helped in elucidating the function of the giant members of the low density lipoprotein (LDL) receptor (LDLR) supergene family. The cDNA encoding a large protein structurally closely related to LDLR, and hence named LDLR-related protein (LRP......), was cloned by Herz et al. in 1988.'Evidence was provided demonstrating that LRP can function as a receptor for chylomicron remnants@-migrating very low density lipoproteins (P-VLDL) rich in apolipoprotein E (apoE)?' The a2-macroglobulin (a2M) receptor (a2MR) was purified from rat livep and human p l a~e n t...... from the observation that affinity-purified a2MR/LRP contains a 40-kDa5.8 or 39-kDa6.' protein, designated a2MRAP, in addition to the a2MFULRP a- and P-chains. cDNA cloning" disclosed the 323-residue protein as both the human homologue of mouse heparin binding protein 44 (see reference 11) and...

  8. Low-Density Lipoprotein Receptor-Related Protein 6 (LRP6 Is a Novel Nutritional Therapeutic Target for Hyperlipidemia, Non-Alcoholic Fatty Liver Disease, and Atherosclerosis

    Directory of Open Access Journals (Sweden)

    Gwang-woong Go

    2015-06-01

    Full Text Available Low-density lipoprotein receptor-related protein 6 (LRP6 is a member of the low-density lipoprotein receptor family and has a unique structure, which facilitates its multiple functions as a co-receptor for Wnt/β-catenin signaling and as a ligand receptor for endocytosis. The role LRP6 plays in metabolic regulation, specifically in the nutrient-sensing pathway, has recently garnered considerable interest. Patients carrying an LRP6 mutation exhibit elevated levels of LDL cholesterol, triglycerides, and fasting glucose, which cooperatively constitute the risk factors of metabolic syndrome and atherosclerosis. Since the discovery of this mutation, the general role of LRP6 in lipid homeostasis, glucose metabolism, and atherosclerosis has been thoroughly researched. These studies have demonstrated that LRP6 plays a role in LDL receptor-mediated LDL uptake. In addition, when the LRP6 mutant impaired Wnt-LRP6 signaling, hyperlipidemia, non-alcoholic fatty liver disease, and atherosclerosis developed. LRP6 regulates lipid homeostasis and body fat mass via the nutrient-sensing mechanistic target of the rapamycin (mTOR pathway. Furthermore, the mutant LRP6 triggers atherosclerosis by activating platelet-derived growth factor (PDGF-dependent vascular smooth muscle cell differentiation. This review highlights the exceptional opportunities to study the pathophysiologic contributions of LRP6 to metabolic syndrome and cardiovascular diseases, which implicate LRP6 as a latent regulator of lipid metabolism and a novel therapeutic target for nutritional intervention.

  9. Analysis of the binding of pro-urokinase and urokinase-plasminogen activator inhibitor-1 complex to the low density lipoprotein receptor-related protein using a Fab fragment selected from a phage-displayed Fab library

    NARCIS (Netherlands)

    Horn, I. R.; Moestrup, S. K.; van den Berg, B. M.; Pannekoek, H.; Nielsen, M. S.; van Zonneveld, A. J.

    1995-01-01

    The low density lipoprotein receptor-related protein/alpha 2-macroglobulin receptor (LRP) mediates endocytosis of a number of structurally unrelated ligands, including complexes of plasminogen activator inhibitor type 1 (PAI-1) and tissue-type plasminogen activator (t-PA) or urokinase plasminogen

  10. Loss of Macrophage Low-Density Lipoprotein Receptor-Related Protein 1 Confers Resistance to the Antiatherogenic Effects of Tumor Necrosis Factor-α Inhibition.

    Science.gov (United States)

    Zhu, Lin; Giunzioni, Ilaria; Tavori, Hagai; Covarrubias, Roman; Ding, Lei; Zhang, Youmin; Ormseth, Michelle; Major, Amy S; Stafford, John M; Linton, MacRae F; Fazio, Sergio

    2016-08-01

    Antiatherosclerotic effects of tumor necrosis factor-α (TNF-α) blockade in patients with systemic inflammatory states are not conclusively demonstrated, which suggests that effects depend on the cause of inflammation. Macrophage LRP1 (low-density lipoprotein receptor-related protein 1) and apoE contribute to inflammation through different pathways. We studied the antiatherosclerosis effects of TNF-α blockade in hyperlipidemic mice lacking either LRP1 (MΦLRP1(-/-)) or apoE from macrophages. Lethally irradiated low-density lipoprotein receptor (LDLR)(-/-) mice were reconstituted with bone marrow from either wild-type, MΦLRP1(-/-), apoE(-/-) or apoE(-/-)/MΦLRP1(-/-)(DKO) mice, and then treated with the TNF-α inhibitor adalimumab while fed a Western-type diet. Adalimumab reduced plasma TNF-α concentration, suppressed blood ly6C(hi) monocyte levels and their migration into the lesion, and reduced lesion cellularity and inflammation in both wild-type→LDLR(-/-) and apoE(-/-)→LDLR(-/-) mice. Overall, adalimumab reduced lesion burden by 52% to 57% in these mice. Adalimumab reduced TNF-α and blood ly6C(hi) monocyte levels in MΦLRP1(-/-)→LDLR(-/-) and DKO→LDLR(-/-) mice, but it did not suppress ly6C(hi) monocyte migration into the lesion or atherosclerosis progression. Our results show that TNF-α blockade exerts antiatherosclerotic effects that are dependent on the presence of macrophage LRP1. © 2016 American Heart Association, Inc.

  11. Effect of neoadjuvant chemotherapy on low-density lipoprotein (LDL) receptor and LDL receptor-related protein 1 (LRP-1) receptor in locally advanced breast cancer

    International Nuclear Information System (INIS)

    Pires, L.A.; Hegg, R.; Freitas, F.R.; Tavares, E.R.; Almeida, C.P.; Baracat, E.C.; Maranhão, R.C.

    2012-01-01

    Low-density lipoprotein (LDL) receptors are overexpressed in most neoplastic cell lines and provide a mechanism for the internalization and concentration of drug-laden nanoemulsions that bind to these receptors. The aim of the present study was to determine whether the administration of standard chemotherapeutic schemes can alter the expression of LDL and LDL receptor-related protein 1 (LRP-1) receptors in breast carcinoma. Fragments of tumoral and normal breast tissue from 16 consecutive volunteer women with breast cancer in stage II or III were obtained from biopsies before the beginning of neoadjuvant chemotherapy and after chemotherapy, from fragments excised during mastectomy. Tissues were analyzed by immunohistochemistry for both receptors. Because complete response to treatment was achieved in 4 patients, only the tumors from 12 were analyzed. Before chemotherapy, there was overexpression of LDL receptor in the tumoral tissue compared to normal breast tissue in 8 of these patients. LRP-1 receptor overexpression was observed in tumors of 4 patients. After chemotherapy, expression of both receptors decreased in the tumors of 6 patients, increased in 4 and was unchanged in 2. Nonetheless, even when chemotherapy reduced receptors expression, the expression was still above normal. The fact that chemotherapy does not impair LDL receptors expression supports the use of drug carrier systems that target neoplastic cells by the LDL receptor endocytic pathway in patients on conventional chemotherapy

  12. Mitogen-activated protein kinase signaling pathways promote low-density lipoprotein receptor-related protein 1-mediated internalization of beta-amyloid protein in primary cortical neurons.

    Science.gov (United States)

    Yang, Wei-Na; Ma, Kai-Ge; Qian, Yi-Hua; Zhang, Jian-Shui; Feng, Gai-Feng; Shi, Li-Li; Zhang, Zhi-Chao; Liu, Zhao-Hui

    2015-07-01

    Mounting evidence suggests that the pathological hallmarks of Alzheimer's disease (AD) are caused by the intraneuronal accumulation of beta-amyloid protein (Aβ). Reuptake of extracellular Aβ is believed to contribute significantly to the intraneuronal Aβ pool in the early stages of AD. Published reports have claimed that the low-density lipoprotein receptor-related protein 1 (LRP1) mediates Aβ1-42 uptake and lysosomal trafficking in GT1-7 neuronal cells and mouse embryonic fibroblast non-neuronal cells. However, there is no direct evidence supporting the role of LRP1 in Aβ internalization in primary neurons. Our recent study indicated that p38 MAPK and ERK1/2 signaling pathways are involved in regulating α7 nicotinic acetylcholine receptor (α7nAChR)-mediated Aβ1-42 uptake in SH-SY5Y cells. This study was designed to explore the regulation of MAPK signaling pathways on LRP1-mediated Aβ internalization in neurons. We found that extracellular Aβ1-42 oligomers could be internalized into endosomes/lysosomes and mitochondria in cortical neurons. Aβ1-42 and LRP1 were also found co-localized in neurons during Aβ1-42 internalization, and they could form Aβ1-42-LRP1 complex. Knockdown of LRP1 expression significantly decreased neuronal Aβ1-42 internalization. Finally, we identified that p38 MAPK and ERK1/2 signaling pathways regulated the internalization of Aβ1-42 via LRP1. Therefore, these results demonstrated that LRP1, p38 MAPK and ERK1/2 mediated the internalization of Aβ1-42 in neurons and provided evidence that blockade of LRP1 or inhibitions of MAPK signaling pathways might be a potential approach to lowering brain Aβ levels and served a potential therapeutic target for AD. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Activated α2 -Macroglobulin Induces Mesenchymal Cellular Migration Of Raw264.7 Cells Through Low-Density Lipoprotein Receptor-Related Protein 1.

    Science.gov (United States)

    Ferrer, Darío G; Dato, Virginia Actis; Fincati, Javier R Jaldín; Lorenc, Valeria E; Sánchez, María C; Chiabrando, Gustavo A

    2017-07-01

    Distinct modes of cell migration contribute to diverse types of cell movements. The mesenchymal mode is characterized by a multistep cycle of membrane protrusion, the formation of focal adhesion, and the stabilization at the leading edge associated with the degradation of extracellular matrix (ECM) components and with regulated extracellular proteolysis. Both α 2 -Macroglobulin (α 2 M) and its receptor, low density lipoprotein receptor-related protein 1 (LRP1), play important roles in inflammatory processes, by controlling the extracellular activity of several proteases. The binding of the active form of α 2 M (α 2 M*) to LRP1 can also activate different signaling pathways in macrophages, thus inducing extracellular matrix metalloproteinase-9 (MMP-9) activation and cellular proliferation. In the present study, we investigated whether the α 2 M*/LRP1 interaction induces cellular migration of the macrophage-derived cell line, Raw264.7. By using the wound-scratch migration assay and confocal microscopy, we demonstrate that α 2 M* induces LRP1-mediated mesenchymal cellular migration. This migration exhibits the production of enlarged cellular protrusions, MT1-MMP distribution to these leading edge protrusions, actin polymerization, focal adhesion formation, and increased intracellular LRP1/β1-integrin colocalization. Moreover, the presence of calphostin-C blocked the α 2 M*-stimulated cellular protrusions, suggesting that the PKC activation is involved in the cellular motility of Raw264.7 cells. These findings could constitute a therapeutic target for inflammatory processes with deleterious consequences for human health, such as rheumatoid arthritis, atherosclerosis and cancer. J. Cell. Biochem. 118: 1810-1818, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  14. Association of polymorphisms in low-density lipoprotein receptor- related protein 5 gene with bone mineral density in postmenopausal Chinese women

    Institute of Scientific and Technical Information of China (English)

    Zhen-lin ZHANG; Yue-juan QIN; Jin-wei HE; Qi-ren HUANG; Miao LI; Yun-qiu HU; Yu-juan LIU

    2005-01-01

    Aim: To investigate the possible association of Q89R, N740N and A1330V polymorphisms in low-density lipoprotein receptor-related protein 5 (LRP5) gene with bone mineral density (BMD) in postmenopausal Chinese women. Methods: Q89R,N740N and A1330V genotypes were determined by polymerase chain reactionrestriction fragment length polymorphism (PCR-RFLP) in 647 unrelated healthy postmenopausal Han Chinese women aged 43-76 years in Shanghai. BMD at lumbar spine 1-4 and the left proximal femur including the femoral neck, trochanter and Ward's triangle were measured by dual-energy X-ray absorptionmetry in all subjects. Results: The distribution of the Q89R, N740N and A1330V genotypes in this population was as follows: QQ 80.5%, QR 18.7%, and RR 0.8%; TT 66.9%,TC 31.1%, and CC 2.0%; AA 68.0%, AV 29.7%, and VV 2.3%. The frequencies of the Q89R, N740N and A1330V genotypes and alleles did not deviate from the HardyWeinberg equilibrium. We found that the Q89R and A1330V polymorphisms were in linkage disequilibrium in our population (x2= 13.50, P<0.01). Both before and after adjusting for age, years since menopause, height, and weight, the Q89R or N740N genotypes were significantly associated with BMD at the femoral neck (P<0.05).Subjects with the Q89R QQ genotype or the N740N TT genotype had a significantly higher BMD at the femoral neck, compared with those with the QR/RR or TC/CC genotypes, respectively. No significant association was found between A1330V polymorphism and BMD at any site. Conclusion: Our findings suggest that the LRP5 gene is a candidate for the genetic determination of BMD in postmenopausal Chinese women.

  15. The p38 mitogen-activated protein kinase signaling pathway is involved in regulating low-density lipoprotein receptor-related protein 1-mediated β-amyloid protein internalization in mouse brain.

    Science.gov (United States)

    Ma, Kai-Ge; Lv, Jia; Hu, Xiao-Dan; Shi, Li-Li; Chang, Ke-Wei; Chen, Xin-Lin; Qian, Yi-Hua; Yang, Wei-Na; Qu, Qiu-Min

    2016-07-01

    Alzheimer's disease (AD) is one of the most common neurodegenerative diseases. Recently, increasing evidence suggests that intracellular β-amyloid protein (Aβ) alone plays a pivotal role in the progression of AD. Therefore, understanding the signaling pathway and proteins that control Aβ internalization may provide new insight for regulating Aβ levels. In the present study, the regulation of Aβ internalization by p38 mitogen-activated protein kinases (MAPK) through low-density lipoprotein receptor-related protein 1 (LRP1) was analyzed in vivo. The data derived from this investigation revealed that Aβ1-42 were internalized by neurons and astrocytes in mouse brain, and were largely deposited in mitochondria and lysosomes, with some also being found in the endoplasmic reticulum. Aβ1-42-LRP1 complex was formed during Aβ1-42 internalization, and the p38 MAPK signaling pathway was activated by Aβ1-42 via LRP1. Aβ1-42 and LRP1 were co- localized in the cells of parietal cortex and hippocampus. Furthermore, the level of LRP1-mRNA and LRP1 protein involved in Aβ1-42 internalization in mouse brain. The results of this investigation demonstrated that Aβ1-42 induced an LRP1-dependent pathway that related to the activation of p38 MAPK resulting in internalization of Aβ1-42. These results provide evidence supporting a key role for the p38 MAPK signaling pathway which is involved in the regulation of Aβ1-42 internalization in the parietal cortex and hippocampus of mouse through LRP1 in vivo. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Analysis of a two-domain binding site for the urokinase-type plasminogen activator-plasminogen activator inhibitor-1 complex in low-density-lipoprotein-receptor-related protein.

    Science.gov (United States)

    Andersen, O M; Petersen, H H; Jacobsen, C; Moestrup, S K; Etzerodt, M; Andreasen, P A; Thøgersen, H C

    2001-07-01

    The low-density-lipoprotein-receptor (LDLR)-related protein (LRP) is composed of several classes of domains, including complement-type repeats (CR), which occur in clusters that contain binding sites for a multitude of different ligands. Each approximately 40-residue CR domain contains three conserved disulphide linkages and an octahedral Ca(2+) cage. LRP is a scavenging receptor for ligands from extracellular fluids, e.g. alpha(2)-macroglobulin (alpha(2)M)-proteinase complexes, lipoprotein-containing particles and serine proteinase-inhibitor complexes, like the complex between urokinase-type plasminogen activator (uPA) and the plasminogen activator inhibitor-1 (PAI-1). In the present study we analysed the interaction of the uPA-PAI-1 complex with an ensemble of fragments representing a complete overlapping set of two-domain fragments accounting for the ligand-binding cluster II (CR3-CR10) of LRP. By ligand blotting, solid-state competition analysis and surface-plasmon-resonance analysis, we demonstrate binding to multiple CR domains, but show a preferential interaction between the uPA-PAI-1 complex and a two-domain fragment comprising CR domains 5 and 6 of LRP. We demonstrate that surface-exposed aspartic acid and tryptophan residues at identical positions in the two homologous domains, CR5 and CR6 (Asp(958,CR5), Asp(999,CR6), Trp(953,CR5) and Trp(994,CR6)), are critical for the binding of the complex as well as for the binding of the receptor-associated protein (RAP) - the folding chaperone/escort protein required for transport of LRP to the cell surface. Accordingly, the present work provides (1) an identification of a preferred binding site within LRP CR cluster II; (2) evidence that the uPA-PAI-1 binding site involves residues from two adjacent protein domains; and (3) direct evidence identifying specific residues as important for the binding of uPA-PAI-1 as well as for the binding of RAP.

  17. What are lipoproteins doing in the brain?

    Science.gov (United States)

    Wang, Hong; Eckel, Robert H

    2014-01-01

    Lipoproteins in plasma transport lipids between tissues, however, only high-density lipoproteins (HDL) appear to traverse the blood-brain barrier (BBB); thus, lipoproteins found in the brain must be produced within the central nervous system. Apolipoproteins E (ApoE) and ApoJ are the most abundant apolipoproteins in the brain, are mostly synthesized by astrocytes, and are found on HDL. In the hippocampus and other brain regions, lipoproteins help to regulate neurobehavioral functions by processes that are lipoprotein receptor-mediated. Moreover, lipoproteins and their receptors also have roles in the regulation of body weight and energy balance, acting through lipoprotein lipase (LPL) and the low-density lipoprotein (LDL) receptor-related protein (LRP). Thus, understanding lipoproteins and their metabolism in the brain provides a new opportunity with potential therapeutic relevance. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Remnant lipoproteins

    DEFF Research Database (Denmark)

    Varbo, Anette; Nordestgaard, Børge G.

    2017-01-01

    Purpose of review: To review recent advances in the field of remnant lipoproteins and remnant cholesterol with a focus on cardiovascular disease risk. Recent findings: In line with previous years' research, current observational, genetic, and mechanistic studies find remnant lipoproteins (defined...... of cardiovascular disease risk reduction through remnant lipoprotein lowering are under way....

  19. Remnant lipoproteins.

    Science.gov (United States)

    Varbo, Anette; Nordestgaard, Børge G

    2017-08-01

    To review recent advances in the field of remnant lipoproteins and remnant cholesterol with a focus on cardiovascular disease risk. In line with previous years' research, current observational, genetic, and mechanistic studies find remnant lipoproteins (defined in different ways) to be involved in atherosclerosis development and cardiovascular disease risk. High concentrations of remnant cholesterol could explain some of the residual risk of cardiovascular disease seen after LDL cholesterol lowering. This will be increasingly important as populations worldwide become more obese and more have diabetes, both of which elevate remnant cholesterol concentrations. Many smaller scale studies and post hoc analyses show that remnant cholesterol can be lowered by different types of drugs; however, results from large scale studies with the primary aim of reducing cardiovascular disease risk through lowering of remnant cholesterol in individuals with elevated concentrations are still missing, although some are under way. Remnant cholesterol is a risk factor for cardiovascular disease, and can be lowered by different types of drugs; however, large scale studies of cardiovascular disease risk reduction through remnant lipoprotein lowering are under way.

  20. LDL Receptor-Related Protein-1 (LRP1 Regulates Cholesterol Accumulation in Macrophages.

    Directory of Open Access Journals (Sweden)

    Anna P Lillis

    Full Text Available Within the circulation, cholesterol is transported by lipoprotein particles and is taken up by cells when these particles associate with cellular receptors. In macrophages, excessive lipoprotein particle uptake leads to foam cell formation, which is an early event in the development of atherosclerosis. Currently, mechanisms responsible for foam cell formation are incompletely understood. To date, several macrophage receptors have been identified that contribute to the uptake of modified forms of lipoproteins leading to foam cell formation, but the in vivo contribution of the LDL receptor-related protein 1 (LRP1 to this process is not known [corrected]. To investigate the role of LRP1 in cholesterol accumulation in macrophages, we generated mice with a selective deletion of LRP1 in macrophages on an LDL receptor (LDLR-deficient background (macLRP1-/-. After feeding mice a high fat diet for 11 weeks, peritoneal macrophages isolated from Lrp+/+ mice contained significantly higher levels of total cholesterol than those from macLRP1-/- mice. Further analysis revealed that this was due to increased levels of cholesterol esters. Interestingly, macLRP1-/- mice displayed elevated plasma cholesterol and triglyceride levels resulting from accumulation of large, triglyceride-rich lipoprotein particles in the circulation. This increase did not result from an increase in hepatic VLDL biosynthesis, but rather results from a defect in catabolism of triglyceride-rich lipoprotein particles in macLRP1-/- mice. These studies reveal an important in vivo contribution of macrophage LRP1 to cholesterol homeostasis.

  1. Levels of the soluble LDL receptor-relative LR11 decrease in overweight individuals with type 2 diabetes upon diet-induced weight loss

    NARCIS (Netherlands)

    K.A.C. Berk (Kirsten); R. Vongpromek (Ranitha); M. Jiang (Meizi); W.J. Schneider (Wolfgang); R. Timman (Reinier); A.J.M. Verhoeven; H. Bujo (Hideaki); E.J.G. Sijbrands (Eric); M.T. Mulder (Monique)

    2016-01-01

    markdownabstract__Background and aims__ Cardiovascular disease (CVD) is a major complication in patients with type 2 diabetes (T2D), especially in those with obesity. Plasma soluble low density lipoprotein receptor-relative with 11 ligand-binding repeats (sLR11) plays a role in the development of

  2. Lipoprotein-a

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/007262.htm Lipoprotein-a To use the sharing features on this page, please enable JavaScript. Lipoproteins are molecules made of proteins and fat. They ...

  3. Lipoprotein complex formation

    International Nuclear Information System (INIS)

    Musliner, T.A.; Krauss, R.M.

    1987-01-01

    Transfers of lipids and proteins between different lipoproteins are known to occur in the course of their metabolism. It is likely that these transfers take place during transient physical associations between lipoprotein particles, but the nature and chemical basis for such interactions are poorly understood. The fact that lipid and apolipoprotein movements are particularly prevalent during the intravascular lipolysis of triglyceride-rich lipoproteins suggested to us that lipolysis products accumulating on these particles might promote physical binding with other lipoproteins. To test this hypothesis, we studied interactions between very low-density, low density, and high-density lipoproteins in the setting of partial lipolysis by bovine milk lipoprotein lipase in the presence of limited unesterified fatty acid acceptor. 2 figs., 1 tab

  4. Lipoprotein(a)

    DEFF Research Database (Denmark)

    Langsted, Anne; Kamstrup, Pia R; Nordestgaard, Børge G

    2014-01-01

    OBJECTIVE: There are no recommendations in guidelines on measuring lipoprotein(a) in the fasting or nonfasting state, or on the influence of inflammation. We tested the hypotheses that lipoprotein(a) levels change only minimally in response to normal food intake, and to inflammation. Also, we...... tested whether normal food intake or inflammation influenced lipoprotein(a)'s ability to predict ischemic heart disease. METHODS: We studied 34 829 individuals from the Danish general population using the Copenhagen General Population Study and the Copenhagen City Heart Study. RESULTS: Lipoprotein......(a) levels did not change in response to normal food intake: median fasting levels were 17.3 mg/dL, while median levels at 3-4 h since last meal were 19.4 mg/dL(p = 0.38). Lipoprotein(a) levels increased minimally with increasing levels of C-reactive protein(CRP): median lipoprotein(a) levels at CRP

  5. Familial lipoprotein lipase deficiency

    Science.gov (United States)

    ... lack an enzyme called lipoprotein lipase. Without this enzyme, the body cannot break down fat from digested food. Fat particles called chylomicrons build up in the blood. Risk factors include a family history of lipoprotein lipase deficiency. The condition is usually ...

  6. Activation of lipoprotein lipase by lipoprotein fractions of human serum.

    Science.gov (United States)

    Bier, D M; Havel, R J

    1970-11-01

    Triglycerides in fat emulsions are hydrolyzed by lipoprotein lipase only when they are "activated" by serum lipoproteins. The contribution of different lipoprotein fractions to hydrolysis of triglycerides in soybean oil emulsion was assessed by determining the quantity of lipoprotein fraction required to give half-maximal hydrolysis. Most of the activator property of whole serum from normolipidemic, postabsorptive subjects was in high density lipoproteins. Low density lipoproteins and serum from which all lipoprotein classes were removed had little or no activity. Also, little activator was present in guinea pig serum or in very low density poor serum from an individual with lecithin:cholesterol acyltransferase deficiency, both of which are deficient in high density lipoproteins. Human very low density lipoproteins are potent activators and are much more active than predicted from their content of high density lipoprotein-protein. Per unit weight of protein, very low density lipoproteins had 13 times the activity of high density lipoproteins. These observations suggest that one or more of the major apoproteins of very low density lipoproteins, present as a minor constituent of high density lipoproteins, may be required for the activation process.

  7. Lipoproteins and lipoprotein mimetics for imaging and drug delivery.

    Science.gov (United States)

    Thaxton, C Shad; Rink, Jonathan S; Naha, Pratap C; Cormode, David P

    2016-11-15

    Lipoproteins are a set of natural nanoparticles whose main role is the transport of fats within the body. While much work has been done to develop synthetic nanocarriers to deliver drugs or contrast media, natural nanoparticles such as lipoproteins represent appealing alternatives. Lipoproteins are biocompatible, biodegradable, non-immunogenic and are naturally targeted to some disease sites. Lipoproteins can be modified to act as contrast agents in many ways, such as by insertion of gold cores to provide contrast for computed tomography. They can be loaded with drugs, nucleic acids, photosensitizers or boron to act as therapeutics. Attachment of ligands can re-route lipoproteins to new targets. These attributes render lipoproteins attractive and versatile delivery vehicles. In this review we will provide background on lipoproteins, then survey their roles as contrast agents, in drug and nucleic acid delivery, as well as in photodynamic therapy and boron neutron capture therapy. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Cellular uptake of lipoproteins and Persistent Organic Compounds - An update and new data

    DEFF Research Database (Denmark)

    Hjelmborg, Philip Sebastian; Andreassen, Thomas Kjærgaard; Bonefeld-Jørgensen, Eva Cecilie

    2008-01-01

    including the pesticide DDT (p,p'-dichlorodiphenyltrichloroethane), and especially its metabolite DDE (p,p'-dichlorodiphenyldichloroethene), interacts with nuclear hormone receptors causing these to malfunction, which in turn results in a range of deleterious health effects in humans. The aim of the present...... study was to determine the role of lipoprotein receptors in mouse embryonic fibroblast (MEF) cells in conjunction with uptake of DDT-lipoprotein complexes from supplemented media in vitro. Uptake of DDT by MEF cells was investigated using MEF1 cells carrying the receptors LRP (low-density lipoprotein...... receptor-related protein) and LDLR (low density lipoprotein receptor) present and MEF4 cells with no LRP and LDLR expression. Cells were incubated together with the complex of LDL and [14C]DDT. The receptor function was further evaluated by adding the 40 kDa receptor-associated protein (RAP) which blocks...

  9. Congenital syndactyly in cattle: four novel mutations in the low density lipoprotein receptor-related protein 4 gene (LRP4

    Directory of Open Access Journals (Sweden)

    Höltershinken Martin

    2007-02-01

    Full Text Available Abstract Background Isolated syndactyly in cattle, also known as mulefoot, is inherited as an autosomal recessive trait with variable penetrance in different cattle breeds. Recently, two independent mutations in the bovine LRP4 gene have been reported as the primary cause of syndactyly in the Holstein and Angus cattle breeds. Results We confirmed the previously described LRP4 exon 33 two nucleotide substitution in most of the affected Holstein calves and revealed additional evidence for allelic heterogeneity by the identification of four new LRP4 non-synonymous point mutations co-segregating in Holstein, German Simmental and Simmental-Charolais families. Conclusion We confirmed a significant role of LRP4 mutations in the pathogenesis of congenital syndactyly in cattle. The newly detected missense mutations in the LRP4 gene represent independent mutations affecting different conserved protein domains. However, the four newly described LRP4 mutations do still not explain all analyzed cases of syndactyly.

  10. Impaired LDL receptor-related protein 1 translocation correlates with improved dyslipidemia and atherosclerosis in apoE-deficient mice.

    Directory of Open Access Journals (Sweden)

    Philip L S M Gordts

    Full Text Available OBJECTIVE: Determination of the in vivo significance of LDL receptor-related protein 1 (LRP1 dysfunction on lipid metabolism and atherosclerosis development in absence of its main ligand apoE. METHODS AND RESULTS: LRP1 knock-in mice carrying an inactivating mutation in the NPxYxxL motif were crossed with apoE-deficient mice. In the absence of apoE, relative to LRP1 wild-type animals, LRP1 mutated mice showed an increased clearance of postprandial lipids despite a compromised LRP1 endocytosis rate and inefficient insulin-mediated translocation of the receptor to the plasma membrane, likely due to inefficient slow recycling of the mutated receptor. Postprandial lipoprotein improvement was explained by increased hepatic clearance of triglyceride-rich remnant lipoproteins and accompanied by a compensatory 1.6-fold upregulation of LDLR expression in hepatocytes. One year-old apoE-deficient mice having the dysfunctional LRP1 revealed a 3-fold decrease in spontaneous atherosclerosis development and a 2-fold reduction in LDL-cholesterol levels. CONCLUSION: These findings demonstrate that the NPxYxxL motif in LRP1 is important for insulin-mediated translocation and slow perinuclear endosomal recycling. These LRP1 impairments correlated with reduced atherogenesis and cholesterol levels in apoE-deficient mice, likely via compensatory LDLR upregulation.

  11. Spirochetal Lipoproteins and Immune Evasion

    Science.gov (United States)

    Christodoulides, Alexei; Boyadjian, Ani; Kelesidis, Theodoros

    2017-01-01

    Spirochetes are a major threat to public health. However, the exact pathogenesis of spirochetal diseases remains unclear. Spirochetes express lipoproteins that often determine the cross talk between the host and spirochetes. Lipoproteins are pro-inflammatory, modulatory of immune responses, and enable the spirochetes to evade the immune system. In this article, we review the modulatory effects of spirochetal lipoproteins related to immune evasion. Understanding lipoprotein-induced immunomodulation will aid in elucidating innate pathogenesis processes and subsequent adaptive mechanisms potentially relevant to spirochetal disease vaccine development and treatment. PMID:28424696

  12. Lipoprotein Apheresis for Lipoprotein(a)-Associated Cardiovascular Disease

    DEFF Research Database (Denmark)

    Roeseler, Eberhard; Julius, Ulrich; Heigl, Franz

    2016-01-01

    OBJECTIVE: Lipoprotein(a)-hyperlipoproteinemia (Lp(a)-HLP) along with progressive cardiovascular disease has been approved as indication for regular lipoprotein apheresis (LA) in Germany since 2008. We aimed to study the long-term preventive effect of LA and to assess hypothetical clinical correl...

  13. Genetics of non-conventional lipoprotein fractions

    Science.gov (United States)

    Lipoprotein subclass measures associate with cardiometabolic disease risk. Currently the information that lipoproteins convey on disease risk over that of traditional demographic and lipid measures is minimal, and so their use is clinics is limited. However, lipoprotein subclass perturbations repres...

  14. Lipoprotein metabolism indicators improve cardiovascular risk prediction

    NARCIS (Netherlands)

    Schalkwijk, D.B. van; Graaf, A.A. de; Tsivtsivadze, E.; Parnell, L.D.; Werff-van der Vat, B.J.C. van der; Ommen, B. van; Greef, J. van der; Ordovás, J.M.

    2014-01-01

    Background: Cardiovascular disease risk increases when lipoprotein metabolism is dysfunctional. We have developed a computational model able to derive indicators of lipoprotein production, lipolysis, and uptake processes from a single lipoprotein profile measurement. This is the first study to

  15. Interferon-γ-induced protein 10 in Lyme disease.

    Science.gov (United States)

    Fallahi, P; Elia, G; Bonatti, A

    2017-01-01

    Lyme disease is an infectious disease caused by bacteria of the Borrelia type, that affects about 300,000 people a year in the USA and 65,000 people a year in Europe. Borrelia infection, and Lyme disease, following occupational exposure has been frequently reported in USA, Europe and Asia. The manifestations of Lyme disease include erythema migrans (EM), arthritis, neuroborrelliosis (NB), and others. Cytokines and chemokines primarily orchestrate leukocyte recruitment to the areas of Borrelia infection, and they are critical mediators of immune and inflammatory responses, in particular of the induction of interferon (IFN)-γ and IFN-γ dependent chemokines. In EM high levels of T helper (Th) 1 cells chemoattranctants [monokine induced by IFN-γ (MIG), IFN-γ-induced protein 10 (IP- 10), and IFN-inducible T cell alpha chemoattractant (I-TAC)] have been shown. Synovial tissues and fluids of patients with Lyme Arthritis (LA) (overall with antibiotic-refractory LA) contained exceptionally high levels of Th1 chemoattractants and cytokines, particularly MIG and IFN-γ. In NB concentrations of IP-10 and I-TAC in the cerebrospinal fluid (CSF) were significantly higher, suggesting that IP-10 and I-TAC create a chemokine gradient between the CSF and serum and recruite C-X-C chemokine receptor 3-expressing memory CD4+ T-cells into the CSF of these patients. A positive association between the disseminating capacity of B. burgdorferi and early type I IFN induction has also been shown. These results suggest that IFN-γ dependent chemokines are important biomarkers to monitor the progression and diffusion of the disease in patients with Borrelia infection; further larger studies are needed.

  16. Cellular uptake of lipoproteins and persistent organic compounds-An update and new data

    International Nuclear Information System (INIS)

    Hjelmborg, Philip Sebastian; Andreassen, Thomas Kjaergaard; Bonefeld-Jorgensen, Eva Cecilie

    2008-01-01

    There are a number of interactions related to the transport of lipophilic xenobiotic compounds in the blood stream of mammals. This paper will focus on the interactions between lipoproteins and persistent organic pollutants (POPs) and how these particles are taken up by cells. A number of POPs including the pesticide p,p'-dichlorodiphenyltrichloroethane (DDT), and especially its metabolite p,p'-dichlorodiphenyldichloroethene (DDE), interacts with nuclear hormone receptors causing these to malfunction, which in turn results in a range of deleterious health effects in humans. The aim of the present study was to determine the role of lipoprotein receptors in mouse embryonic fibroblast (MEF) cells in conjunction with uptake of DDT-lipoprotein complexes from supplemented media in vitro. Uptake of DDT by MEF cells was investigated using MEF1 cells carrying the receptors low-density lipoprotein receptor-related protein (LRP) and low-density lipoprotein receptor (LDLR) present and MEF4 cells with no LRP and LDLR expression. Cells were incubated together with the complex of low-density lipoproteins (LDL) and [ 14 C]DDT. The receptor function was further evaluated by adding the 40 kDa receptor-associated protein (RAP) which blocks receptor activity. The results showed that [ 14 C]DDT uptake was decreasing when the LDL concentration was increasing. There was no strong evidence for a receptor-mediated uptake of the [ 14 C]DDT-lipoprotein complex. To conclude, DDT travels in the blood stream and can cross cell membranes while being transported as a DDT-lipoprotein complex. The lipoproteins do not need receptors to cross cell membranes since passive diffusion constitutes a major passageway

  17. Phytosterols, Phytostanols, and Lipoprotein Metabolism

    Directory of Open Access Journals (Sweden)

    Helena Gylling

    2015-09-01

    Full Text Available The efficacy of phytosterols and phytostanols added to foods and food supplements to obtain significant non-pharmacologic serum and low density lipoprotein (LDL cholesterol reduction is well documented. Irrespective of age, gender, ethnic background, body weight, background diet, or the cause of hypercholesterolemia and, even added to statin treatment, phytosterols and phytostanols at 2 g/day significantly lower LDL cholesterol concentration by 8%–10%. They do not affect the concentrations of high density lipoprotein cholesterol, lipoprotein (a or serum proprotein convertase subtilisin/kexin type 9. In some studies, phytosterols and phytostanols have modestly reduced serum triglyceride levels especially in subjects with slightly increased baseline concentrations. Phytosterols and phytostanols lower LDL cholesterol by displacing cholesterol from mixed micelles in the small intestine so that cholesterol absorption is partially inhibited. Cholesterol absorption and synthesis have been carefully evaluated during phytosterol and phytostanol supplementation. However, only a few lipoprotein kinetic studies have been performed, and they revealed that LDL apoprotein B-100 transport rate was reduced. LDL particle size was unchanged, but small dense LDL cholesterol concentration was reduced. In subjects with metabolic syndrome and moderate hypertriglyceridemia, phytostanols reduced not only non- high density lipoprotein (HDL cholesterol concentration but also serum triglycerides by 27%, and reduced the large and medium size very low density lipoprotein particle concentrations. In the few postprandial studies, the postprandial lipoproteins were reduced, but detailed studies with apoprotein B-48 are lacking. In conclusion, more kinetic studies are required to obtain a more complete understanding of the fasting and postprandial lipoprotein metabolism caused by phytosterols and phytostanols. It seems obvious, however, that the most atherogenic lipoprotein

  18. Phytosterols, Phytostanols, and Lipoprotein Metabolism.

    Science.gov (United States)

    Gylling, Helena; Simonen, Piia

    2015-09-17

    The efficacy of phytosterols and phytostanols added to foods and food supplements to obtain significant non-pharmacologic serum and low density lipoprotein (LDL) cholesterol reduction is well documented. Irrespective of age, gender, ethnic background, body weight, background diet, or the cause of hypercholesterolemia and, even added to statin treatment, phytosterols and phytostanols at 2 g/day significantly lower LDL cholesterol concentration by 8%-10%. They do not affect the concentrations of high density lipoprotein cholesterol, lipoprotein (a) or serum proprotein convertase subtilisin/kexin type 9. In some studies, phytosterols and phytostanols have modestly reduced serum triglyceride levels especially in subjects with slightly increased baseline concentrations. Phytosterols and phytostanols lower LDL cholesterol by displacing cholesterol from mixed micelles in the small intestine so that cholesterol absorption is partially inhibited. Cholesterol absorption and synthesis have been carefully evaluated during phytosterol and phytostanol supplementation. However, only a few lipoprotein kinetic studies have been performed, and they revealed that LDL apoprotein B-100 transport rate was reduced. LDL particle size was unchanged, but small dense LDL cholesterol concentration was reduced. In subjects with metabolic syndrome and moderate hypertriglyceridemia, phytostanols reduced not only non- high density lipoprotein (HDL) cholesterol concentration but also serum triglycerides by 27%, and reduced the large and medium size very low density lipoprotein particle concentrations. In the few postprandial studies, the postprandial lipoproteins were reduced, but detailed studies with apoprotein B-48 are lacking. In conclusion, more kinetic studies are required to obtain a more complete understanding of the fasting and postprandial lipoprotein metabolism caused by phytosterols and phytostanols. It seems obvious, however, that the most atherogenic lipoprotein particles will be

  19. Radiolabelled lipoproteins and method for making same

    International Nuclear Information System (INIS)

    Lees, R.S.

    1987-01-01

    A method is described for detecting accumulation of low density lipoproteins in an arterial wall, the method comprising the steps of A. preparing a technetium-99m-labelled low density lipoprotein in a solution having a pH between 8 and 9; B. injecting the labelled low density lipoprotein into the vascular system of a patient; C. subsequently viewing the patient's vascular system with extracorporeally-located detecting means capable of detecting the labelled low density lipoprotein; D. determining from the detecting means the locations of the labelled density lipoproteins; and E. quantifying concentrations of the labelled low density lipoproteins at the locations to determine the accumulation of the lipoproteins

  20. Synthetic Lipoproteins as Carriers for Drug Delivery.

    Science.gov (United States)

    Huang, Gangliang; Liu, Yang; Huang, Hualiang

    2016-01-01

    Synthetic lipoprotein is an effective carrier of targeted delivery for drugs. It has the very small size, good biocompatibility, suitable half-life, and specific lipoprotein receptorbinding capacity. Compared with the traditional natural lipoprotein, synthetic lipoprotein not only retains the original biological characteristics and functions, but also exhibits the excellent characteristics in drug delivery. Herein, the advantages, development, applications, and prospect of synthetic lipoproteins as drug carriers were summarized.

  1. Ectodomains of the LDL receptor-related proteins LRP1b and LRP4 have anchorage independent functions in vivo.

    Directory of Open Access Journals (Sweden)

    Martin F Dietrich

    2010-04-01

    Full Text Available The low-density lipoprotein (LDL receptor gene family is a highly conserved group of membrane receptors with diverse functions in developmental processes, lipoprotein trafficking, and cell signaling. The low-density lipoprotein (LDL receptor-related protein 1b (LRP1B was reported to be deleted in several types of human malignancies, including non-small cell lung cancer. Our group has previously reported that a distal extracellular truncation of murine Lrp1b that is predicted to secrete the entire intact extracellular domain (ECD is fully viable with no apparent phenotype.Here, we have used a gene targeting approach to create two mouse lines carrying internally rearranged exons of Lrp1b that are predicted to truncate the protein closer to the N-terminus and to prevent normal trafficking through the secretary pathway. Both mutations result in early embryonic lethality, but, as expected from the restricted expression pattern of LRP1b in vivo, loss of Lrp1b does not cause cellular lethality as homozygous Lrp1b-deficient blastocysts can be propagated normally in culture. This is similar to findings for another LDL receptor family member, Lrp4. We provide in vitro evidence that Lrp4 undergoes regulated intramembraneous processing through metalloproteases and gamma-secretase cleavage. We further demonstrate negative regulation of the Wnt signaling pathway by the soluble extracellular domain.Our results underline a crucial role for Lrp1b in development. The expression in mice of truncated alleles of Lrp1b and Lrp4 with deletions of the transmembrane and intracellular domains leads to release of the extracellular domain into the extracellular space, which is sufficient to confer viability. In contrast, null mutations are embryonically (Lrp1b or perinatally (Lrp4 lethal. These findings suggest that the extracellular domains of both proteins may function as a scavenger for signaling ligands or signal modulators in the extracellular space, thereby

  2. Transendothelial lipoprotein exchange and microalbuminuria

    DEFF Research Database (Denmark)

    Jensen, Jan Skov; Feldt-Rasmussen, Bo; Jensen, Kurt Svarre

    2004-01-01

    OBJECTIVE: Microalbuminuria associates with increased risk of atherosclerosis in individuals without diabetes. We hypothesized that transendothelial lipoprotein exchange is elevated among such individuals, possibly explaining increased intimal lipoprotein accumulation and thus atherosclerosis....... METHODS: Using an in vivo isotope technique, transendothelial exchange of low density lipoprotein (LDL) was measured in 77 non-diabetic individuals. Autologous 131-iodinated LDL was reinjected intravenously, and the 1-h fractional escape rate was calculated as index of transendothelial exchange. RESULTS......: There was no difference in transendothelial LDL exchange between subjects with microalbuminuria versus normoalbuminuria (mean (95% confidence interval) 3.8%/h (3.3-4.3%/h) versus 4.2%/h (3.7-4.7%/h); P=0.33). In contrast, there was a positive correlation between transendothelial LDL exchange and (logarithmically...

  3. Aerosol preparation of intact lipoproteins

    Science.gov (United States)

    Benner, W Henry [Danville, CA; Krauss, Ronald M [Berkeley, CA; Blanche, Patricia J [Berkeley, CA

    2012-01-17

    A medical diagnostic method and instrumentation system for analyzing noncovalently bonded agglomerated biological particles is described. The method and system comprises: a method of preparation for the biological particles; an electrospray generator; an alpha particle radiation source; a differential mobility analyzer; a particle counter; and data acquisition and analysis means. The medical device is useful for the assessment of human diseases, such as cardiac disease risk and hyperlipidemia, by rapid quantitative analysis of lipoprotein fraction densities. Initially, purification procedures are described to reduce an initial blood sample to an analytical input to the instrument. The measured sizes from the analytical sample are correlated with densities, resulting in a spectrum of lipoprotein densities. The lipoprotein density distribution can then be used to characterize cardiac and other lipid-related health risks.

  4. Ion mobility analysis of lipoproteins

    Science.gov (United States)

    Benner, W. Henry; Krauss, Ronald M.; Blanche, Patricia J.

    2007-08-21

    A medical diagnostic method and instrumentation system for analyzing noncovalently bonded agglomerated biological particles is described. The method and system comprises: a method of preparation for the biological particles; an electrospray generator; an alpha particle radiation source; a differential mobility analyzer; a particle counter; and data acquisition and analysis means. The medical device is useful for the assessment of human diseases, such as cardiac disease risk and hyperlipidemia, by rapid quantitative analysis of lipoprotein fraction densities. Initially, purification procedures are described to reduce an initial blood sample to an analytical input to the instrument. The measured sizes from the analytical sample are correlated with densities, resulting in a spectrum of lipoprotein densities. The lipoprotein density distribution can then be used to characterize cardiac and other lipid-related health risks.

  5. Classifying lipoproteins based on their polar profiles.

    Science.gov (United States)

    Polanco, Carlos; Castañón-González, Jorge Alberto; Buhse, Thomas; Uversky, Vladimir N; Amkie, Rafael Zonana

    2016-01-01

    The lipoproteins are an important group of cargo proteins known for their unique capability to transport lipids. By applying the Polarity index algorithm, which has a metric that only considers the polar profile of the linear sequences of the lipoprotein group, we obtained an analytical and structural differentiation of all the lipoproteins found in UniProt Database. Also, the functional groups of lipoproteins, and particularly of the set of lipoproteins relevant to atherosclerosis, were analyzed with the same method to reveal their structural preference, and the results of Polarity index analysis were verified by an alternate test, the Cumulative Distribution Function algorithm, applied to the same groups of lipoproteins.

  6. Single-Particle Tracking of Human Lipoproteins.

    Science.gov (United States)

    de Messieres, Michel; Ng, Abby; Duarte, Cornelio J; Remaley, Alan T; Lee, Jennifer C

    2016-01-05

    Lipoproteins, such as high-density lipoprotein (HDL), low-density lipoprotein (LDL), and very-low density lipoprotein (VLDL), play a critical role in heart disease. Lipoproteins vary in size and shape as well as in their apolipoprotein content. Here, we developed a new experimental framework to study freely diffusing lipoproteins from human blood, allowing analysis of even the smallest HDL with a radius of 5 nm. In an easily constructed confinement chamber, individual HDL, LDL, and VLDL particles labeled with three distinct fluorophores were simultaneously tracked by wide-field fluorescence microscopy and their sizes were determined by their motion. This technique enables studies of individual lipoproteins in solution and allows characterization of the heterogeneous properties of lipoproteins which affect their biological function but are difficult to discern in bulk studies.

  7. Structural studies on lipoprotein lipase

    International Nuclear Information System (INIS)

    Socorro, L.

    1985-01-01

    The structure of lipoprotein lipase is not known. The lack of information on its primary sequence has been due to the inability of preparing it in homogeneous and stable form. This research has focused on the structural characterization of lipoprotein lipase. The first approach taken was to develop a purification method using bovine milk and affinity chromatography on heparin-Sepharose. The protein obtained was a heterogeneous peak with the activity shifted towards the trailing edge fractions. These fractions only presented a 55 Kdalton band on polyacrylamide gel electrophoresis. Monoclonal antibodies against this band detected an endogenous, phenyl methane sulfonyl fluoride-sensitive protease responsible for the presence of lower molecular weight fragments. The second approach was to label the lipoprotein lipase with a radioactive, active site, directed probe. After incubation and affinity chromatography a complex [ 3 H]inhibitor enzyme was isolated with a stoichiometry of 1.00 +/- 0.2. The complex was digested with CNBr and the insoluble peptides at low ionic strength (>90% [ 3 H]dpm) were used for further purification. Differential extraction of the [ 3 H]-peptide, digestion with S. aureus V8 protease, and high performance liquid chromatography yielded a hexapeptide with a composition consistent with the consensus sequence of the active site peptides of many serine-esterase. This and the kinetic data imply this being the mechanism of action for lipoprotein lipase

  8. Revisiting the gram-negative lipoprotein paradigm

    Science.gov (United States)

    The processing of lipoproteins (lpps) in Gram-negative bacteria is generally considered to be an essential pathway. Mature lipoproteins in these bacteria are triacylated, with the final fatty acid addition performed by Lnt, an apolipoprotein n-acyltransferase. The mature lipoproteins are then sorted...

  9. Lipoprotein(a) and dietary proteins: casein lowers lipoprotein(a) concentrations as compared with soy protein1-3

    DEFF Research Database (Denmark)

    Nilausen, Karin Johanne; Meinertz, H.

    1999-01-01

    Lipoprotein(a), plasma lipoproteins, dietary proteins, soy protein, casein, liquid-formula, coronary artery disease, men, Denmark......Lipoprotein(a), plasma lipoproteins, dietary proteins, soy protein, casein, liquid-formula, coronary artery disease, men, Denmark...

  10. Effects of hormones on lipids and lipoproteins

    Energy Technology Data Exchange (ETDEWEB)

    Krauss, R.M.

    1991-12-01

    Levels of plasma lipids and lipoproteins are strong predictors for the development of atherosclerotic cardiovascular disease in postmenopausal women. In women, as in men, numerous factors contribute to variations in plasma lipoproteins that may affect cardiovascular disease risk. These include age, dietary components, adiposity, genetic traits, and hormonal changes. Each of these factors may operate to varying degrees in determining changes in plasma lipoprotein profiles accompanying menopause- Cross-sectional and longitudinal studies have suggested increases in levels of cholesterol, low density lipoproteins (LDL) and triglyceride-rich lipoproteins associated with menopause. High density lipoproteins (HDL), which are higher in women than men and are thought to contribute to relative protection of premenopausal women from cardiovascular disease, remain relatively constant in the years following menopause, although small, and perhaps transient reductions in the HDL{sub 2} subfraction have been reported in relation to reduced estradiol level following menopause. Despite these associations, it has been difficult to determine the role of endogenous hormones in influencing the plasma lipoproteins of postmenopausal women. In principle, the effects of hormone replacement should act to reverse any alterations in lipoprotein metabolism that are due to postmenopausal hormone changes. While there may be beneficial effects on lipoproteins, hormone treatment does not restore a premenopausal lipoprotein profile. Furthermore, it is not dear to what extent exogenous hormone-induced lipoprotein changes contribute to the reduced incidence of cardiovascular disease with hormone replacement therapy.

  11. Metabolism of lipoproteins by human fetal hepatocytes

    International Nuclear Information System (INIS)

    Carr, B.R.

    1987-01-01

    The rate of clearance of lipoproteins from plasma appears to play a role in the development of atherogenesis. The liver may account for as much as two thirds of the removal of low-density lipoprotein and one third of the clearance of high-density lipoprotein in certain animal species and humans, mainly by receptor-mediated pathways. The purpose of the present investigation was to determine if human fetal hepatocytes maintained in vitro take up and degrade lipoproteins. We first determined that the maximal binding capacity of iodine 125-iodo-LDL was approximately 300 ng of low-density lipoprotein protein/mg of membrane protein and an apparent dissociation constant of approximately 60 micrograms low-density lipoprotein protein/ml in membranes prepared from human fetal liver. We found that the maximal uptake of [ 125 I]iodo-LDL and [ 125 I]iodo-HDL by fetal hepatocytes occurred after 12 hours of incubation. Low-density lipoprotein uptake preceded the appearance of degradation products by 4 hours, and thereafter the degradation of low-density lipoprotein increased linearly for at least 24 hours. In contrast, high-density lipoprotein was not degraded to any extent by fetal hepatocytes. [ 125 I]Iodo-LDL uptake and degradation were inhibited more than 75% by preincubation with low-density lipoprotein but not significantly by high-density lipoprotein, whereas [ 125 I]iodo-HDL uptake was inhibited 70% by preincubation with high-density lipoprotein but not by low-density lipoprotein. In summary, human fetal hepatocytes take up and degrade low-density lipoprotein by a receptor-mediated process similar to that described for human extrahepatic tissues

  12. Biogenesis and Membrane Targeting of Lipoproteins.

    Science.gov (United States)

    Narita, Shin-Ichiro; Tokuda, Hajime

    2010-09-01

    Bacterial lipoproteins represent a unique class of membrane proteins, which are anchored to membranes through triacyl chains attached to the amino-terminal cysteine. They are involved in various functions localized in cell envelope. Escherichia coli possesses more than 90 species of lipoproteins, most of which are localized in the outer membrane, with others being in the inner membrane. All lipoproteins are synthesized in the cytoplasm with an N-terminal signal peptide, translocated across the inner membrane by the Sec translocon to the periplasmic surface of the inner membrane, and converted to mature lipoproteins through sequential reactions catalyzed by three lipoprotein-processing enzymes: Lgt, LspA, and Lnt. The sorting of lipoproteins to the outer membrane requires a system comprising five Lol proteins. An ATP-binding cassette transporter, LolCDE, initiates the sorting by mediating the detachment of lipoproteins from the inner membrane. Formation of the LolA-lipoprotein complex is coupled to this LolCDE-dependent release reaction. LolA accommodates the amino-terminal acyl chain of lipoproteins in its hydrophobic cavity, thereby generating a hydrophilic complex that can traverse the periplasmic space by diffusion. Lipoproteins are then transferred to LolB on the outer membrane and anchored to the inner leaflet of the outer membrane by the action of LolB. In contrast, since LolCDE does not recognize lipoproteins possessing Asp at position +2, these lipoproteins remain anchored to the inner membrane. Genes for Lol proteins are widely conserved among gram-negative bacteria, and Lol-mediated outer membrane targeting of lipoproteins is considered to be the general lipoprotein localization mechanism.

  13. Postprandial Hyperlipidemia and Remnant Lipoproteins.

    Science.gov (United States)

    Masuda, Daisaku; Yamashita, Shizuya

    2017-02-01

    Fasting hypertriglyceridemia is positively associated with the morbidity of coronary heart disease (CHD), and postprandial (non-fasting) hypertriglyceridemia is also correlated with the risk status for CHD, which is related to the increase in chylomicron (CM) remnant lipoproteins produced from the intestine. CM remnant particles, as well as oxidized low density lipoprotein (LDL) or very low density lipoprotein (VLDL) remnants, are highly atherogenic and act by enhancing systemic inflammation, platelet activation, coagulation, thrombus formation, and macrophage foam cell formation. The cholesterol levels of remnant lipoproteins significantly correlate with small, dense LDL; impaired glucose tolerance (IGT) and CHD prevalence. We have developed an assay of apolipoprotein (apo)B-48 levels to evaluate the accumulation of CM remnants. Fasting apoB-48 levels correlate with the morbidity of postprandial hypertriglyceridemia, obesity, type III hyperlipoproteinemia, the metabolic syndrome, hypothyroidism, chronic kidney disease, and IGT. Fasting apoB-48 levels also correlate with carotid intima-media thickening and CHD prevalence, and a high apoB-48 level is a significant predictor of CHD risk, independent of the fasting TG level. Diet interventions, such as dietary fibers, polyphenols, medium-chain fatty acids, diacylglycerol, and long-chain n-3 polyunsaturated fatty acids (PUFA), ameliorate postprandial hypertriglyceridemia, moreover, drugs for dyslipidemia (n-3 PUFA, statins, fibrates or ezetimibe) and diabetes concerning incretins (dipeptidyl-peptidase IV inhibitor or glucagon like peptide-1 analogue) may improve postprandial hypertriglyceridemia. Since the accumulation of CM remnants correlates to impaired lipid and glucose metabolism and atherosclerotic cardiovascular events, further studies are required to investigate the characteristics, physiological activities, and functions of CM remnants for the development of new interventions to reduce atherogenicity.

  14. A More Flexible Lipoprotein Sorting Pathway

    Science.gov (United States)

    Chahales, Peter

    2015-01-01

    Lipoprotein biogenesis in Gram-negative bacteria occurs by a conserved pathway, each step of which is considered essential. In contrast to this model, LoVullo and colleagues demonstrate that the N-acyl transferase Lnt is not required in Francisella tularensis or Neisseria gonorrhoeae. This suggests the existence of a more flexible lipoprotein pathway, likely due to a modified Lol transporter complex, and raises the possibility that pathogens may regulate lipoprotein processing to modulate interactions with the host. PMID:25755190

  15. Lipoprotein metabolism indicators improve cardiovascular risk prediction.

    Directory of Open Access Journals (Sweden)

    Daniël B van Schalkwijk

    Full Text Available BACKGROUND: Cardiovascular disease risk increases when lipoprotein metabolism is dysfunctional. We have developed a computational model able to derive indicators of lipoprotein production, lipolysis, and uptake processes from a single lipoprotein profile measurement. This is the first study to investigate whether lipoprotein metabolism indicators can improve cardiovascular risk prediction and therapy management. METHODS AND RESULTS: We calculated lipoprotein metabolism indicators for 1981 subjects (145 cases, 1836 controls from the Framingham Heart Study offspring cohort in which NMR lipoprotein profiles were measured. We applied a statistical learning algorithm using a support vector machine to select conventional risk factors and lipoprotein metabolism indicators that contributed to predicting risk for general cardiovascular disease. Risk prediction was quantified by the change in the Area-Under-the-ROC-Curve (ΔAUC and by risk reclassification (Net Reclassification Improvement (NRI and Integrated Discrimination Improvement (IDI. Two VLDL lipoprotein metabolism indicators (VLDLE and VLDLH improved cardiovascular risk prediction. We added these indicators to a multivariate model with the best performing conventional risk markers. Our method significantly improved both CVD prediction and risk reclassification. CONCLUSIONS: Two calculated VLDL metabolism indicators significantly improved cardiovascular risk prediction. These indicators may help to reduce prescription of unnecessary cholesterol-lowering medication, reducing costs and possible side-effects. For clinical application, further validation is required.

  16. Analytic ultracentrifugation of lipoproteins: Some current collaborations

    International Nuclear Information System (INIS)

    Lindgren, F.T.

    1987-01-01

    This summary briefly reports on three ongoing studies - the heterogeneity of Low Density Lipoproteins (LDL) in the cynomolgus monkey, the domain nature of Apolipoprotein E-3, and the molecular weight of apoB-100 in low density lipoprotein subfractions in normal males. 4 refs

  17. Peroxisome Proliferator Activated Receptors and Lipoprotein Metabolism

    NARCIS (Netherlands)

    Kersten, A.H.

    2008-01-01

    Plasma lipoproteins are responsible for carrying triglycerides and cholesterol in the blood and ensuring their delivery to target organs. Regulation of lipoprotein metabolism takes place at numerous levels including via changes in gene transcription. An important group of transcription factors that

  18. Lipoprotein (a) Blood Test: MedlinePlus Lab Test Information

    Science.gov (United States)

    ... this page: https://medlineplus.gov/labtests/lipoproteinabloodtest.html Lipoprotein (a) Blood Test To use the sharing features ... this page, please enable JavaScript. What is a Lipoprotein (a) Blood Test? A lipoprotein (a) test measures ...

  19. Degradation of tissue-type plasminogen activator by human monocyte- derived macrophages is mediated by the mannose receptor and by the low- density lipoprotein receptor-related protein

    NARCIS (Netherlands)

    Noorman, F.; Braat, E.A.M.; Rijken, D.C.

    1995-01-01

    The balance of tissue-type plasminogen activator (t-PA) production and degradation determines its concentration in blood and tissues. Disturbance of this balance may result in either increased or decreased proteolysis. In the present study, we identified the receptor systems involved in the

  20. beta-Arrestin Promotes Wnt-induced Low Density Lipoprotein Receptor-related Protein 6 (Lrp6) Phosphorylation via Increased Membrane Recruitment of Amer1 Protein

    Czech Academy of Sciences Publication Activity Database

    Kříž, Vitězslav; Pospíchalová, V.; Mašek, Jan; Kilander, M.B.C.; Slavík, J.; Tanneberger, K.; Schulte, G.; Machala, M.; Kozubík, Alois; Behrens, J.; Bryja, Vítězslav

    2014-01-01

    Roč. 289, č. 2 (2014), s. 1128-1141 ISSN 0021-9258 R&D Projects: GA ČR(CZ) GA204/09/0498; GA ČR(CZ) GA13-32990S Grant - others:GA ČR(CZ) GC204/09/J030 Institutional support: RVO:68081707 ; RVO:68378050 Keywords : CONVERGENT EXTENSION MOVEMENTS * SIGNALING PATHWAYS * IN-VIVO Subject RIV: BO - Biophysics; EB - Genetics ; Molecular Biology (UMG-J) Impact factor: 4.573, year: 2014

  1. Structural studies of human cell surface receptors : On low-density lipoprotein receptor-related protein 1 and epidermal growth factor receptors 2 and 3

    NARCIS (Netherlands)

    De Nardis, C.

    2017-01-01

    The elucidation of proteins’ structure and function is of great importance for the understanding of disease triggering mechanisms and for the development of new drugs. In this thesis, different biophysical and biochemical techniques were employed to gain insights into the structural and functional

  2. Impact of gain-of-function mutations in the low-density lipoprotein receptor-related protein 5 (LRP5) on glucose and lipid homeostasis

    DEFF Research Database (Denmark)

    Foer, D; Zhu, M; Cardone, R L

    2017-01-01

    potentially represents a target for drug discovery in type 2 diabetes and hyperlipidemia. Studies in animal models suggest a physiologic link between LRP5 and glucose and lipid homeostasis; however, whether it plays a similar role in humans is unclear. As current literature links loss-of-function LRP5...... to impaired glucose and lipid metabolism, we hypothesized that individuals with an HBM-causing mutation in LRP5 would exhibit improved glucose and lipid homeostasis. Since studies in animal models have suggested that Wnt signaling augments insulin secretion, we also examined the effect of Wnt signaling...... on glucose-stimulated insulin secretion on human pancreatic islets. METHODS: This was a matched case-control study. We used several methods to assess glucose and lipid metabolism in 11 individuals with HBM-causing mutations in LRP5. Affected study participants were recruited from previously identified...

  3. Characterization of the Interaction of Sclerostin with the Low Density Lipoprotein Receptor-related Protein (LRP) Family of Wnt Co-receptors

    Czech Academy of Sciences Publication Activity Database

    Holdsworth, G.; Slocombe, P.; Doyle, C.; Sweeney, B.; Veverka, Václav; Le Riche, K.; Franklin, R. J.; Compson, J.; Brookings, D.; Turner, J.; Kennedy, J.; Garlish, R.; Shi, J.; Newnham, L.; McMillan, D.; Muzylak, M.; Carr, M. D.; Henry, A. J.; Ceska, T.; Robinson, M. K.

    2012-01-01

    Roč. 287, č. 32 (2012), s. 26464-26477 ISSN 0021-9258 Institutional research plan: CEZ:AV0Z40550506 Keywords : Wnt pathway * LRP * sclerostin Subject RIV: CE - Biochemistry Impact factor: 4.651, year: 2012

  4. Genomic determinants of triglyceride and cholesterol distribution into lipoprotein fractions in the rat.

    Directory of Open Access Journals (Sweden)

    Miloslava Hodúlová

    Full Text Available The plasma profile of major lipoprotein classes and its subdivision into particular fractions plays a crucial role in the pathogenesis of atherosclerosis and is a major predictor of coronary artery disease. Our aim was to identify genomic determinants of triglyceride and cholesterol distribution into lipoprotein fractions and lipoprotein particle sizes in the recombinant inbred rat set PXO, in which alleles of two rat models of the metabolic syndrome (SHR and PD inbred strains segregate together with those from Brown Norway rat strain. Adult male rats of 15 PXO strains (n = 8-13/strain and two progenitor strains SHR-Lx (n = 13 and BXH2/Cub (n = 18 were subjected to one-week of high-sucrose diet feeding. We performed association analyses of triglyceride (TG and cholesterol (C concentrations in 20 lipoprotein fractions and the size of major classes of lipoprotein particles utilizing 704 polymorphic microsatellite markers, the genome-wide significance was validated by 2,000 permutations per trait. Subsequent in silico focusing of the identified quantitative trait loci was completed using a map of over 20,000 single nucleotide polymorphisms. In most of the phenotypes we identified substantial gradient among the strains (e.g. VLDL-TG from 5.6 to 66.7 mg/dl. We have identified 14 loci (encompassing 1 to 65 genes on rat chromosomes 3, 4, 7, 8, 11 and 12 showing suggestive or significant association to one or more of the studied traits. PXO strains carrying the SHR allele displayed significantly higher values of the linked traits except for LDL-TG and adiposity index. Cholesterol concentrations in large, medium and very small LDL particles were significantly associated to a haplotype block spanning part of a single gene, low density lipoprotein receptor-related protein 1B (Lrp1b. Using genome-wide association we have identified new genetic determinants of triglyceride and cholesterol distribution into lipoprotein fractions in the recombinant

  5. Modulating Estrogen Receptor-related Receptor-α Activity Inhibits Cell Proliferation*

    OpenAIRE

    Bianco, Stéphanie; Lanvin, Olivia; Tribollet, Violaine; Macari, Claire; North, Sophie; Vanacker, Jean-Marc

    2009-01-01

    High expression of the estrogen receptor-related receptor (ERR)-α in human tumors is correlated to a poor prognosis, suggesting an involvement of the receptor in cell proliferation. In this study, we show that a synthetic compound (XCT790) that modulates the activity of ERRα reduces the proliferation of various cell lines and blocks the G1/S transition of the cell cycle in an ERR...

  6. Bacterial lipoproteins; biogenesis, sorting and quality control.

    Science.gov (United States)

    Narita, Shin-Ichiro; Tokuda, Hajime

    2017-11-01

    Bacterial lipoproteins are a subset of membrane proteins localized on either leaflet of the lipid bilayer. These proteins are anchored to membranes through their N-terminal lipid moiety attached to a conserved Cys. Since the protein moiety of most lipoproteins is hydrophilic, they are expected to play various roles in a hydrophilic environment outside the cytoplasmic membrane. Gram-negative bacteria such as Escherichia coli possess an outer membrane, to which most lipoproteins are sorted. The Lol pathway plays a central role in the sorting of lipoproteins to the outer membrane after lipoprotein precursors are processed to mature forms in the cytoplasmic membrane. Most lipoproteins are anchored to the inner leaflet of the outer membrane with their protein moiety in the periplasm. However, recent studies indicated that some lipoproteins further undergo topology change in the outer membrane, and play critical roles in the biogenesis and quality control of the outer membrane. This article is part of a Special Issue entitled: Bacterial Lipids edited by Russell E. Bishop. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Effect of phospholipase A treatment of low density lipoproteins on the dextran sulfate--lipoprotein interaction.

    Science.gov (United States)

    Nishida, T

    1968-09-01

    The effect of phospholipase A on the interaction of low density lipoproteins of the S(f) 0-10 class with dextran sulfate was studied in phosphate buffer of pH 7.4, ionic strength 0.1, by chemical, spectrophotometric, and centrifugal methods. When low density lipoproteins that had been treated with phospholipase A were substituted for untreated lipoproteins, the amount of insoluble dextran sulfate-lipoprotein complex formed was greatly reduced. Hydrolysis of over 20% of the lecithin and phosphatidyl ethanolamine constituents of the lipoproteins prevented the formation of insoluble complex. However, even the lipoproteins in which almost all the phosphoglycerides were hydrolyzed produced soluble complex, which was converted to insoluble complex upon addition of magnesium sulfate. It is apparent that the lipoproteins altered extensively by treatment with phospholipase A retain many characteristic properties of native low density lipoproteins. Fatty acids, but not lysolecithin, released by the action of phospholipase A interfered with the formation of insoluble complex; this interference was due to association of the fatty acids with the lipoproteins. With increases in the concentration of the associated fatty acids, the amounts of magnesium ion required for the conversion of soluble complex to insoluble complex increased progressively. Charge interaction is evidently of paramount importance in the formation of sulfated polysaccharide-lipoprotein complexes.

  8. A more flexible lipoprotein sorting pathway.

    Science.gov (United States)

    Chahales, Peter; Thanassi, David G

    2015-05-01

    Lipoprotein biogenesis in Gram-negative bacteria occurs by a conserved pathway, each step of which is considered essential. In contrast to this model, LoVullo and colleagues demonstrate that the N-acyl transferase Lnt is not required in Francisella tularensis or Neisseria gonorrhoeae. This suggests the existence of a more flexible lipoprotein pathway, likely due to a modified Lol transporter complex, and raises the possibility that pathogens may regulate lipoprotein processing to modulate interactions with the host. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  9. High triglycerides and low high-density lipoprotein cholesterol lipid profile in rheumatoid arthritis: A potential link among inflammation, oxidative status, and dysfunctional high-density lipoprotein.

    Science.gov (United States)

    Rodríguez-Carrio, Javier; Alperi-López, Mercedes; López, Patricia; López-Mejías, Raquel; Alonso-Castro, Sara; Abal, Francisco; Ballina-García, Francisco J; González-Gay, Miguel Á; Suárez, Ana

    The interactions between inflammation and lipid profile in rheumatoid arthritis (RA) are poorly understood. The lipid profile study in RA has been biased toward lipoprotein levels, whereas those of triglycerides (TGs) and lipoprotein functionality have been underestimated. Since recent findings suggest a role for TG and TG-rich lipoproteins (TRL) on inflammation, we aimed to evaluate a combined lipid profile characterized by high TG and low high-density lipoprotein cholesterol levels (TG high HDL low ) in RA. Lipid profiles were analyzed in 113 RA patients, 113 healthy controls, and 27 dyslipemic subjects. Levels of inflammatory mediators, paraoxonase-1 (PON1) activity, and total antioxidant capacity were quantified in serum. PON1-rs662 status was evaluated by real-time polymerase chain reaction. The TG high HDL low profile was detected in 29/113 RA patients. Although no differences in prevalence compared with healthy controls or dyslipemic subjects were observed, this profile was associated with increased tumor necrosis factor α (P = .004), monocyte chemotactic protein (P = .004), interferon-gamma-inducible protein-10 (P = .018), and leptin (P < .001) serum levels in RA, where decreased PON1 activity and total antioxidant capacity were found. TG high HDL low prevalence was lower among anti-TNFα-treated patients (P = .004). When RA patients were stratified by PON1-rs662 status, these associations remained in the low-activity genotype (QQ). Finally, a poor clinical response on TNFα blockade was related to an increasing prevalence of the TG high HDL low profile over treatment (P = .021) and higher TRL levels at baseline (P = .042). The TG high HDL low profile is associated with systemic inflammation, decreased PON1 activity, and poor clinical outcome on TNFα blockade in RA, suggesting a role of TRL and HDL dysfunction as the missing link between inflammation and lipid profile. Copyright © 2017 National Lipid Association. Published by Elsevier Inc

  10. The majority of lipoprotein lipase in plasma is bound to remnant lipoproteins: A new definition of remnant lipoproteins.

    Science.gov (United States)

    Sato, Koichi; Okajima, Fumikazu; Miyashita, Kazuya; Imamura, Shigeyuki; Kobayashi, Junji; Stanhope, Kimber L; Havel, Peter J; Machida, Tetsuo; Sumino, Hiroyuki; Murakami, Masami; Schaefer, Ernst; Nakajima, Katsuyuki

    2016-10-01

    Lipoprotein lipase (LPL) is a multifunctional protein and a key enzyme involved in the regulation of lipoprotein metabolism. We determined the lipoproteins to which LPL is bound in the pre-heparin and post-heparin plasma. Tetrahydrolipstatin (THL), a potent inhibitor of serine lipases, was used to block the lipolytic activity of LPL, thereby preventing changes in the plasma lipoproteins due to ex vivo lipolysis. Gel filtration was performed to obtain the LPL elution profiles in plasma and the isolated remnant lipoproteins (RLP). When ex vivo lipolytic activity was inhibited by THL in the post-heparin plasma, majority of the LPL was found in the VLDL elution range, specifically in the RLP as inactive dimers. However, in the absence of THL, most of the LPL was found in the HDL elution range as active dimers. Furthermore, majority of the LPL in the pre-heparin plasma was found in the RLP as inactive form, with broadly diffused lipoprotein profiles in the presence and absence of THL. It is suggested that during lipolysis in vivo, the endothelial bound LPL dimers generates RLP, forming circulating RLP-LPL complexes in an inactive form that subsequently binds and initiates receptor-mediated catabolism. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Nutrigenetics of the lipoprotein metabolism.

    Science.gov (United States)

    Garcia-Rios, Antonio; Perez-Martinez, Pablo; Delgado-Lista, Javier; Lopez-Miranda, Jose; Perez-Jimenez, Francisco

    2012-01-01

    It is well known that lipid metabolism is a cornerstone in the development of the commonest important chronic diseases worldwide, such as obesity, cardiovascular disease, or metabolic syndrome. In this regard, the area of lipid and lipoprotein metabolism is one of the areas in which the understanding of the development and progression of those metabolic disorders has been studied in greater depth. Thus, growing evidence has demonstrated that while universal recommendations might be appropriate for the general population, in this area there is great variability among individuals, related to a combination of environmental and genetic factors. Moreover, the interaction between genetic and dietary components has helped in understanding this variability. Therefore, with further study into the interaction between the most important genetic markers or single-nucleotide polymorphisms (SNPs) and diet, it may be possible to understand the variability in lipid metabolism, which could lead to an increase in the use of personalized nutrition as the best support to combat metabolic disorders. This review discusses some of the evidence in which candidate SNPs can affect the key players of lipid metabolism and how their phenotypic manifestations can be modified by dietary intake. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Normal and abnormal lipid and lipoprotein metabolism

    African Journals Online (AJOL)

    2009-03-20

    Mar 20, 2009 ... This article focuses on lipid and lipoprotein metabolism and introduces a range of genetic ... spherical structures that are suspended in the plasma and whose ..... atherosclerosis. Table II suggests a simple classification of.

  13. Low-density lipoprotein analysis in microchip capillary electrophoresis systems

    NARCIS (Netherlands)

    Ceriotti, Laura; Shibata, Takayuki; Folmer, Britta; Weiller, Bruce H.; Roberts, Matthew A.; De Rooij, Nico F.; Verpoorte, Elisabeth

    2002-01-01

    Due to the mounting evidence for altered lipoprotein and cholesterol-lipoprotein content in several disease states, there has been an increasing interest in analytical methods for lipoprotein profiling for diagnosis. The separation of low- and high-density lipoproteins (LDL and HDL, respectively)

  14. Contribution of lipoproteins and lipoprotein processing to endocarditis virulence in Streptococcus sanguinis.

    Science.gov (United States)

    Das, Sankar; Kanamoto, Taisei; Ge, Xiuchun; Xu, Ping; Unoki, Takeshi; Munro, Cindy L; Kitten, Todd

    2009-07-01

    Streptococcus sanguinis is an important cause of infective endocarditis. Previous studies have identified lipoproteins as virulence determinants in other streptococcal species. Using a bioinformatic approach, we identified 52 putative lipoprotein genes in S. sanguinis strain SK36 as well as genes encoding the lipoprotein-processing enzymes prolipoprotein diacylglyceryl transferase (lgt) and signal peptidase II (lspA). We employed a directed signature-tagged mutagenesis approach to systematically disrupt these genes and screen each mutant for the loss of virulence in an animal model of endocarditis. All mutants were viable. In competitive index assays, mutation of a putative phosphate transporter reduced in vivo competitiveness by 14-fold but also reduced in vitro viability by more than 20-fold. Mutations in lgt, lspA, or an uncharacterized lipoprotein gene reduced competitiveness by two- to threefold in the animal model and in broth culture. Mutation of ssaB, encoding a putative metal transporter, produced a similar effect in culture but reduced in vivo competiveness by >1,000-fold. [(3)H]palmitate labeling and Western blot analysis confirmed that the lgt mutant failed to acylate lipoproteins, that the lspA mutant had a general defect in lipoprotein cleavage, and that SsaB was processed differently in both mutants. These results indicate that the loss of a single lipoprotein, SsaB, dramatically reduces endocarditis virulence, whereas the loss of most other lipoproteins or of normal lipoprotein processing has no more than a minor effect on virulence.

  15. Contribution of Lipoproteins and Lipoprotein Processing to Endocarditis Virulence in Streptococcus sanguinis▿ §

    Science.gov (United States)

    Das, Sankar; Kanamoto, Taisei; Ge, Xiuchun; Xu, Ping; Unoki, Takeshi; Munro, Cindy L.; Kitten, Todd

    2009-01-01

    Streptococcus sanguinis is an important cause of infective endocarditis. Previous studies have identified lipoproteins as virulence determinants in other streptococcal species. Using a bioinformatic approach, we identified 52 putative lipoprotein genes in S. sanguinis strain SK36 as well as genes encoding the lipoprotein-processing enzymes prolipoprotein diacylglyceryl transferase (lgt) and signal peptidase II (lspA). We employed a directed signature-tagged mutagenesis approach to systematically disrupt these genes and screen each mutant for the loss of virulence in an animal model of endocarditis. All mutants were viable. In competitive index assays, mutation of a putative phosphate transporter reduced in vivo competitiveness by 14-fold but also reduced in vitro viability by more than 20-fold. Mutations in lgt, lspA, or an uncharacterized lipoprotein gene reduced competitiveness by two- to threefold in the animal model and in broth culture. Mutation of ssaB, encoding a putative metal transporter, produced a similar effect in culture but reduced in vivo competiveness by >1,000-fold. [3H]palmitate labeling and Western blot analysis confirmed that the lgt mutant failed to acylate lipoproteins, that the lspA mutant had a general defect in lipoprotein cleavage, and that SsaB was processed differently in both mutants. These results indicate that the loss of a single lipoprotein, SsaB, dramatically reduces endocarditis virulence, whereas the loss of most other lipoproteins or of normal lipoprotein processing has no more than a minor effect on virulence. PMID:19395487

  16. The Human Pathogen Streptococcus pyogenes Releases Lipoproteins as Lipoprotein-rich Membrane Vesicles.

    Science.gov (United States)

    Biagini, Massimiliano; Garibaldi, Manuela; Aprea, Susanna; Pezzicoli, Alfredo; Doro, Francesco; Becherelli, Marco; Taddei, Anna Rita; Tani, Chiara; Tavarini, Simona; Mora, Marirosa; Teti, Giuseppe; D'Oro, Ugo; Nuti, Sandra; Soriani, Marco; Margarit, Immaculada; Rappuoli, Rino; Grandi, Guido; Norais, Nathalie

    2015-08-01

    Bacterial lipoproteins are attractive vaccine candidates because they represent a major class of cell surface-exposed proteins in many bacteria and are considered as potential pathogen-associated molecular patterns sensed by Toll-like receptors with built-in adjuvanticity. Although Gram-negative lipoproteins have been extensively characterized, little is known about Gram-positive lipoproteins. We isolated from Streptococcus pyogenes a large amount of lipoproteins organized in vesicles. These vesicles were obtained by weakening the bacterial cell wall with a sublethal concentration of penicillin. Lipid and proteomic analysis of the vesicles revealed that they were enriched in phosphatidylglycerol and almost exclusively composed of lipoproteins. In association with lipoproteins, a few hypothetical proteins, penicillin-binding proteins, and several members of the ExPortal, a membrane microdomain responsible for the maturation of secreted proteins, were identified. The typical lipidic moiety was apparently not necessary for lipoprotein insertion in the vesicle bilayer because they were also recovered from the isogenic diacylglyceryl transferase deletion mutant. The vesicles were not able to activate specific Toll-like receptor 2, indicating that lipoproteins organized in these vesicular structures do not act as pathogen-associated molecular patterns. In light of these findings, we propose to name these new structures Lipoprotein-rich Membrane Vesicles. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  17. Nuclear magnetic resonance studies of lipoproteins

    International Nuclear Information System (INIS)

    Hamilton, J.A.; Morrisett, J.D.

    1986-01-01

    Several nuclei in lipoproteins are magnetically active and are thus potential NMR probes of lipoprotein structure. Table I lists the magnetic isotopes preset in the covalent structures of the molecular constituents of lipoproteins: lipids, proteins, and carbohydrates. Every type of nucleus that is part of the endogenous structure of these molecules has at least one magnetic isotope. Each magnetic nucleus represents an intrinsic and completely nonperturbing probe (when at the natural abundance level) of local molecular motion and magnetic environment. The NMR experiment itself is also nonperturbing and nondestructive. Table I also lists for each nucleus its nuclear spin, its natural isotopic abundance, its sensitivity, and its resonance frequency at two commonly employed magnetic in the low field range (21.14 kG or 2.11 Tesla) and the other in the high field range (47.0 kG or 4.70 Tesla). Of the nuclei listed in Table I, /sup 1/H, /sup 13/C, and /sup 31/P have been the primary ones studied in lipoproteins. The general advantages and disadvantages afforded by these and other nuclei as probes of lipoprotein structure are discussed. /sup 13/C NMR spectroscopy, the method which has had the most extensive application (and probably has the greatest future potential) to lipoproteins, is treated in greatest detail, but many of the principles described apply to other nuclei as well

  18. Genetic determinants of LDL, lipoprotein(a), triglyceride-rich lipoproteins and HDL: concordance and discordance with cardiovascular disease risk

    DEFF Research Database (Denmark)

    Nordestgaard, Børge G; Tybjærg-Hansen, Anne

    2011-01-01

    To evaluate whether new and known genetic determinants of plasma levels of LDL cholesterol, lipoprotein(a), triglyceride-rich lipoproteins, and HDL cholesterol associate with the risk of cardiovascular disease expected from the effect on lipoprotein levels. Concordance or discordance...... of such genetic determinants with cardiovascular disease risk will either favor or disfavor that these lipoproteins are causally related to cardiovascular disease....

  19. Combined analysis of six lipoprotein lipase genetic variants on triglycerides, high-density lipoprotein, and ischemic heart disease

    DEFF Research Database (Denmark)

    Wittrup, Hans H; Andersen, Rolf V; Tybjaerg-Hansen, Anne

    2006-01-01

    Genetic variants in lipoprotein lipase may affect triglycerides, high-density lipoprotein (HDL), and risk of ischemic heart disease (IHD).......Genetic variants in lipoprotein lipase may affect triglycerides, high-density lipoprotein (HDL), and risk of ischemic heart disease (IHD)....

  20. Delivery of circulating lipoproteins to specific neurons in the Drosophila brain regulates systemic insulin signaling.

    Science.gov (United States)

    Brankatschk, Marko; Dunst, Sebastian; Nemetschke, Linda; Eaton, Suzanne

    2014-10-02

    The Insulin signaling pathway couples growth, development and lifespan to nutritional conditions. Here, we demonstrate a function for the Drosophila lipoprotein LTP in conveying information about dietary lipid composition to the brain to regulate Insulin signaling. When yeast lipids are present in the diet, free calcium levels rise in Blood Brain Barrier glial cells. This induces transport of LTP across the Blood Brain Barrier by two LDL receptor-related proteins: LRP1 and Megalin. LTP accumulates on specific neurons that connect to cells that produce Insulin-like peptides, and induces their release into the circulation. This increases systemic Insulin signaling and the rate of larval development on yeast-containing food compared with a plant-based food of similar nutritional content.

  1. Revisiting the Gram-negative lipoprotein paradigm.

    Science.gov (United States)

    LoVullo, Eric D; Wright, Lori F; Isabella, Vincent; Huntley, Jason F; Pavelka, Martin S

    2015-05-01

    The processing of lipoproteins (Lpps) in Gram-negative bacteria is generally considered an essential pathway. Mature lipoproteins in these bacteria are triacylated, with the final fatty acid addition performed by Lnt, an apolipoprotein N-acyltransferase. The mature lipoproteins are then sorted by the Lol system, with most Lpps inserted into the outer membrane (OM). We demonstrate here that the lnt gene is not essential to the Gram-negative pathogen Francisella tularensis subsp. tularensis strain Schu or to the live vaccine strain LVS. An LVS Δlnt mutant has a small-colony phenotype on sucrose medium and increased susceptibility to globomycin and rifampin. We provide data indicating that the OM lipoprotein Tul4A (LpnA) is diacylated but that it, and its paralog Tul4B (LpnB), still sort to the OM in the Δlnt mutant. We present a model in which the Lol sorting pathway of Francisella has a modified ABC transporter system that is capable of recognizing and sorting both triacylated and diacylated lipoproteins, and we show that this modified system is present in many other Gram-negative bacteria. We examined this model using Neisseria gonorrhoeae, which has the same Lol architecture as that of Francisella, and found that the lnt gene is not essential in this organism. This work suggests that Gram-negative bacteria fall into two groups, one in which full lipoprotein processing is essential and one in which the final acylation step is not essential, potentially due to the ability of the Lol sorting pathway in these bacteria to sort immature apolipoproteins to the OM. This paper describes the novel finding that the final stage in lipoprotein processing (normally considered an essential process) is not required by Francisella tularensis or Neisseria gonorrhoeae. The paper provides a potential reason for this and shows that it may be widespread in other Gram-negative bacteria. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  2. Lipoprotein profile, lipoprotein-associated phospholipase A2 and cardiovascular risk in hemodialysis patients.

    Science.gov (United States)

    Rolla, Roberta; De Mauri, Andreana; Valsesia, Ambra; Vidali, Matteo; Chiarinotti, Doriana; Bellomo, Giorgio

    2015-12-01

    Cardiovascular disease is the leading cause of morbidity and mortality in hemodialysis patients; the increased risk of cardiovascular disease is due to accelerated atherosclerosis, inflammation and impaired lipoprotein metabolism. We aimed to evaluate lipoprotein-associated phospholipase A2 (Lp-PLA2) and some pro-inflammatory aspects of the lipoprotein profile in dialyzed patients in order to evaluate the relationship with the accelerated atherosclerosis and vascular accidents. In 102 dialysis patients and 40 non-uremic controls, we investigated the lipoprotein plasma profile, high sensitivity C-reactive protein (CRP), ceruloplasmin and serum amyloid A protein (SAA), and followed patients for 1 year to analyze the risk of acute cardiovascular events. Total cholesterol, low-density lipoprotein and high-density lipoprotein plasma levels were significantly lower in uremic patients than controls, whereas CRP, SAA, ceruloplasmin, Lp-PLA2 and their ratio with apolipoprotein A1 were significantly higher. Patients with Lp-PLA2 levels >194 nmol/min/ml had more acute cardiovascular events than patients with lower values. Our results show that in dialysis subjects: (1) low-density lipoproteins show a more atherogenic phenotype than in the general population; (2) high-density lipoproteins are less anti-inflammatory; (3) Lp-PLA2 could potentially be used to evaluate cardiovascular risk.

  3. A Phospholipidomic Analysis of All Defined Human Plasma Lipoproteins

    Science.gov (United States)

    Dashti, Monireh; Kulik, Willem; Hoek, Frans; Veerman, Enno C.; Peppelenbosch, Maikel P.; Rezaee, Farhad

    2011-01-01

    Since plasma lipoproteins contain both protein and phospholipid components, either may be involved in processes such as atherosclerosis. In this study the identification of plasma lipoprotein-associated phospholipids, which is essential for understanding these processes at the molecular level, are performed. LC-ESI/MS, LC-ESI-MS/MS and High Performance Thin Layer Chromatography (HPTLC) analysis of different lipoprotein fractions collected from pooled plasma revealed the presence of phosphatidylethanolamine (PE), phosphatidylinositol (PI), and sphingomyeline (SM) only on lipoproteins and phosphatidylcholine (PC), Lyso-PC on both lipoproteins and plasma lipoprotein free fraction (PLFF). Cardiolipin, phosphatidylglycerol (PG) and Phosphatidylserine (PS) were observed neither in the lipoprotein fractions nor in PLFF. All three approaches led to the same results regarding phospholipids occurrence in plasma lipoproteins and PLFF. A high abundancy of PE and SM was observed in VLDL and LDL fractions respectively. This study provides for the first time the knowledge about the phospholipid composition of all defined plasma lipoproteins. PMID:22355656

  4. Human Lipoproteins at Model Cell Membranes

    DEFF Research Database (Denmark)

    Browning, K L; Lind, T K; Maric, S

    2017-01-01

    High and low density lipoproteins (HDL and LDL) are thought to play vital roles in the onset and development of atherosclerosis; the biggest killer in the western world. Key issues of initial lipoprotein (LP) interactions at cellular membranes need to be addressed including LP deposition and lipid...... exchange. Here we present a protocol for monitoring the in situ kinetics of lipoprotein deposition and lipid exchange/removal at model cellular membranes using the non-invasive, surface sensitive methods of neutron reflection and quartz crystal microbalance with dissipation. For neutron reflection, lipid...... support the notion of HDL acting as the 'good' cholesterol, removing lipid material from lipid-loaded cells, whereas LDL acts as the 'bad' cholesterol, depositing lipid material into the vascular wall....

  5. Liver lipase and high-density lipoprotein. Lipoprotein changes after incubation of human serum with rat liver lipase.

    Science.gov (United States)

    Groot, P H; Scheek, L M; Jansen, H

    1983-05-16

    Human sera were incubated with rat liver lipase after inactivation of lecithin:cholesterol acyltransferase, and the changes in serum lipoprotein composition were measured. In the presence of liver lipase serum triacylglycerol and phosphatidylcholine were hydrolyzed. The main changes in the concentrations of these lipids were found in the high-density lipoprotein fraction. Subfractionation of high-density lipoprotein by rate-zonal ultracentrifugation showed a prominent decrease in all constituents of high-density lipoprotein2, a smaller decrease in the 'light' high-density lipoprotein3 and an increase in the 'heavy' high-density lipoprotein3. These data support a concept in which liver lipase is involved in high-density lipoprotein2 phospholipid and triacylglycerol catabolism and suggest that as a result of this action high-density lipoprotein2 is converted into high-density lipoprotein3.

  6. Inducible protein-10 as a predictive marker of antiviral hepatitis C treatment

    DEFF Research Database (Denmark)

    Neesgaard, Bastian; Ruhwald, Morten; Weis, Nina

    2017-01-01

    AIM: To investigate interferon-γ-inducible protein-10's (IP-10) potential to anticipate rapid (RVR)- and sustained virological responses (SVR) to chronic hepatitis C (CHC) treatment. METHODS: We included case series examining RVR or SVR in relation to 24 or 48 wk treatment for CHC, in patients...... treatment free for at least six months, with genotype 1 or 4, and in relation to 24 wk treatment for genotype 2 and 3, with pegylated interferon in combination with ribavirin. Patients had to have both a baseline IP-10 level as well as a hepatitis C virus (HCV)-RNA determination 4 wk after treatment...... initiation or 24 wk after end of treatment. Studies including patients with liver diseases other than CHC, human immunodeficiency virus-infection, treatment with immunosuppresents or cytostatica, alcohol dependency or active intravenous drug-use were excluded. We found 81 articles by searching the MEDLINE...

  7. Lipoprotein (a) and biochemical parameters in elderly

    OpenAIRE

    Yuttana Sudjaroen

    2016-01-01

    Background: Lipoprotein (a) [Lp(a)] is an low-density lipoprotein like particle and is an important independent risk factor for coronary artery diseases (CAD). Few studies on Lp(a) level in Thai elderly to screening risk of CAD may concerned. Aims: To study the relation of Lp(a) level and routine biochemical parameters including lipid profiles and fasting blood glucose in elderly and to determine risk of subclinical symptoms by using Lp(a) levels as early risk predictor. Settings and Design: ...

  8. Genetic determinants of LDL, lipoprotein(a), triglyceride-rich lipoproteins and HDL: concordance and discordance with cardiovascular disease risk

    DEFF Research Database (Denmark)

    Nordestgaard, Børge G; Tybjærg-Hansen, Anne

    2011-01-01

    To evaluate whether new and known genetic determinants of plasma levels of LDL cholesterol, lipoprotein(a), triglyceride-rich lipoproteins, and HDL cholesterol associate with the risk of cardiovascular disease expected from the effect on lipoprotein levels. Concordance or discordance of such gene......To evaluate whether new and known genetic determinants of plasma levels of LDL cholesterol, lipoprotein(a), triglyceride-rich lipoproteins, and HDL cholesterol associate with the risk of cardiovascular disease expected from the effect on lipoprotein levels. Concordance or discordance...

  9. Modulating Estrogen Receptor-related Receptor-α Activity Inhibits Cell Proliferation*

    Science.gov (United States)

    Bianco, Stéphanie; Lanvin, Olivia; Tribollet, Violaine; Macari, Claire; North, Sophie; Vanacker, Jean-Marc

    2009-01-01

    High expression of the estrogen receptor-related receptor (ERR)-α in human tumors is correlated to a poor prognosis, suggesting an involvement of the receptor in cell proliferation. In this study, we show that a synthetic compound (XCT790) that modulates the activity of ERRα reduces the proliferation of various cell lines and blocks the G1/S transition of the cell cycle in an ERRα-dependent manner. XCT790 induces, in a p53-independent manner, the expression of the cell cycle inhibitor p21waf/cip1 at the protein, mRNA, and promoter level, leading to an accumulation of hypophosphorylated Rb. Finally, XCT790 reduces cell tumorigenicity in Nude mice. PMID:19546226

  10. Specific deletion of LDL receptor-related protein on macrophages has skewed in vivo effects on cytokine production by invariant natural killer T cells.

    Directory of Open Access Journals (Sweden)

    Roman Covarrubias

    Full Text Available Expression of molecules involved in lipid homeostasis such as the low density lipoprotein receptor (LDLr on antigen presenting cells (APCs has been shown to enhance invariant natural killer T (iNKT cell function. However, the contribution to iNKT cell activation by other lipoprotein receptors with shared structural and ligand binding properties to the LDLr has not been described. In this study, we investigated whether a structurally related receptor to the LDLr, known as LDL receptor-related protein (LRP, plays a role in iNKT cell activation. We found that, unlike the LDLr which is highly expressed on all immune cells, the LRP was preferentially expressed at high levels on F4/80+ macrophages (MΦ. We also show that CD169+ MΦs, known to present antigen to iNKT cells, exhibited increased expression of LRP compared to CD169- MΦs. To test the contribution of MΦ LRP to iNKT cell activation we used a mouse model of MΦ LRP conditional knockout (LRP-cKO. LRP-cKO MΦs pulsed with glycolipid alpha-galactosylceramide (αGC elicited normal IL-2 secretion by iNKT hybridoma and in vivo challenge of LRP-cKO mice led to normal IFN-γ, but blunted IL-4 response in both serum and intracellular expression by iNKT cells. Flow cytometric analyses show similar levels of MHC class-I like molecule CD1d on LRP-cKO MΦs and normal glycolipid uptake. Survey of the iNKT cell compartment in LRP-cKO mice revealed intact numbers and percentages and no homeostatic disruption as evidenced by the absence of programmed death-1 and Ly-49 surface receptors. Mixed bone marrow chimeras showed that the inability iNKT cells to make IL-4 is cell extrinsic and can be rescued in the presence of wild type APCs. Collectively, these data demonstrate that, although MΦ LRP may not be necessary for IFN-γ responses, it can contribute to iNKT cell activation by enhancing early IL-4 secretion.

  11. 21 CFR 862.1475 - Lipoprotein test system.

    Science.gov (United States)

    2010-04-01

    ... measure lipoprotein in serum and plasma. Lipoprotein measurements are used in the diagnosis and treatment of lipid disorders (such as diabetes mellitus), atherosclerosis, and various liver and renal diseases...

  12. The Influence of Decreased Levels of High Density Lipoprotein ...

    African Journals Online (AJOL)

    very low density lipoprotein cholesterol, and triglyceride were assayed. ... Abiodun and Gwarzo: Association of high density lipoprotein cholesterol with haemolysis in sickle cell disease ... analyses were carried out to determine the correlation.

  13. Correlation between serum lipoproteins and abdominal fat pad in ...

    African Journals Online (AJOL)

    GREGORY

    2010-08-30

    Aug 30, 2010 ... Triglyceride, cholesterol and VLDL concentrations were positively correlated with ... negative correlation was observed between high-density lipoprotein and ... Abbreviations: HDL, High density lipoprotein; VLDL, very low.

  14. Nonpharmacological lipoprotein apheresis reduces arterial inflammation in familial hypercholesterolemia

    NARCIS (Netherlands)

    van Wijk, Diederik F.; Sjouke, Barbara; Figueroa, Amparo; Emami, Hamed; van der Valk, Fleur M.; MacNabb, Megan H.; Hemphill, Linda C.; Schulte, Dominik M.; Koopman, Marion G.; Lobatto, Mark E.; Verberne, Hein J.; Fayad, Zahi A.; Kastelein, John J. P.; Mulder, Willem J. M.; Hovingh, G. Kees; Tawakol, Ahmed; Stroes, Erik S. G.

    2014-01-01

    Patients with familial hypercholesterolemia (FH) are characterized by elevated atherogenic lipoprotein particles, predominantly low-density lipoprotein cholesterol (LDL-C), which is associated with accelerated atherogenesis and increased cardiovascular risk. This study used (18)F-fluorodeoxyglucose

  15. Lipoprotein receptors in cultured bovine endothelial cells

    International Nuclear Information System (INIS)

    Struempfer, A.E.M.

    1983-07-01

    In this study, receptors that may be involved in the uptake of low density lipoproteins (LDL) and low density lipoproteins which have been modified by acetylation (AcLDL), were characterized. Aortic epithelial cells were used and a cell culture system which closely resembled the in vivo monolayer was established. Endothelial cell and lipoprotein interactions were examined by incubating the cells with 125 l-labelled lipoproteins under various conditions. The receptor affinity of bovine aortic endothelial cells was higher for AcLDL than that for LDL. Competition studies demonstrated that there were two distinct receptors for LDL and AcLDL on the endothelial cells. AcLDL did not compete with LDL for the LDL receptor, and conversely LDL did not compete with AcLDL for the AcLDL receptor. The receptor activities for LDL and AcLDL were examined as a function of culture age. Whereas the LDL receptor could be regulated, the AcLDL receptor was not as susceptible to regulation. Upon exposing endothelial cells for 72 h to either LDL or AcLDL, it was found that the total amount of cellular cholesterol increased by about 50%. However, the increase of total cholesterol was largely in the form of free cholesterol. This is in contrast to macrophages, where the increase in total cholesterol upon exposure to AcLDL is largely in the form cholesteryl esters

  16. Lipoprotein(a Levels in Thyroid Disorders

    Directory of Open Access Journals (Sweden)

    Pop-Radu Cristina Corina

    2013-04-01

    Full Text Available Objective: The aim of this study was to assess the serum levels of Lipoprotein(a [Lp(a] in subjects with thyroid disorders, as well as to investigate their relationship with lipid profile and the markers of thyroid function and autoimmunity, admitting that elevated Lp(a levels and dyslipidemia caused by thyroid disorders synergistically increased the atherogenic process.

  17. Relationship among sera lipoprotein abnormalities in healthy ...

    African Journals Online (AJOL)

    As the prevalence of lipoprotein abnormalities in adolescents is increasing dramatically, the identification of relevant risk factors is a major public health challenge. The aim of this study was to investigate whether a family history of diabetes could be a risk factor for lipid abnormalities in healthy individuals. This study is a ...

  18. Heat shock protein 10 (Hsp10) in immune-related diseases: one coin, two sides

    Science.gov (United States)

    Jia, Haibo; Halilou, Amadou I.; Hu, Liang; Cai, Wenqian; Liu, Jing; Huang, Bo

    2011-01-01

    Heat shock protein 10 (Hsp10) in eukaryotes, originally identified as a mitochondrial chaperone, now is also known to be present in cytosol, cell surface, extracellular space and peripheral blood. Functionally besides participating in mitochondrial protein folding in association with Hsp60, Hsp10 appears to be related to pregnancy, cancer and autoimmune inhibition. Hsp10 can be released to peripheral blood at very early time point of pregnancy and given another name called early pregnancy factor (EPF), which seems to play a critical role in developing a pregnant niche. In malignant disorders, Hsp10 is usually abnormally expressed in the cytosol of malignant cells and further released to extracellular space, resulting in tumor-promoting effect from various aspects. Furthermore, distinct from other heat shock protein members, whose soluble form is recognized as danger signal by immune cells and triggers immune responses, Hsp10 after release, however, is designed to be an inhibitory signal by limiting immune response. This review discusses how Hsp10 participates in various physiological and pathological processes from basic protein molecule folding to pregnancy, cancer and autoimmune diseases, and emphasizes how important the location is for the function exertion of a molecule. PMID:21969171

  19. Isolation and characterization of human apolipoprotein M-containing lipoproteins

    DEFF Research Database (Denmark)

    Christoffersen, Christina; Nielsen, Lars Bo; Axler, Olof

    2006-01-01

    Apolipoprotein M (apoM) is a novel apolipoprotein with unknown function. In this study, we established a method for isolating apoM-containing lipoproteins and studied their composition and the effect of apoM on HDL function. ApoM-containing lipoproteins were isolated from human plasma...... with immunoaffinity chromatography and compared with lipoproteins lacking apoM. The apoM-containing lipoproteins were predominantly of HDL size; approximately 5% of the total HDL population contained apoM. Mass spectrometry showed that the apoM-containing lipoproteins also contained apoJ, apoA-I, apoA-II, apoC-I, apo...

  20. Release of endothelial cell lipoprotein lipase by plasma lipoproteins and free fatty acids

    International Nuclear Information System (INIS)

    Saxena, U.; Witte, L.D.; Goldberg, I.J.

    1989-01-01

    Lipoprotein lipase (LPL) bound to the lumenal surface of vascular endothelial cells is responsible for the hydrolysis of triglycerides in plasma lipoproteins. Studies were performed to investigate whether human plasma lipoproteins and/or free fatty acids would release LPL which was bound to endothelial cells. Purified bovine milk LPL was incubated with cultured porcine aortic endothelial cells resulting in the association of enzyme activity with the cells. When the cells were then incubated with media containing chylomicrons or very low density lipoproteins (VLDL), a concentration-dependent decrease in the cell-associated LPL enzymatic activity was observed. In contrast, incubation with media containing low density lipoproteins or high density lipoproteins produced a much smaller decrease in the cell-associated enzymatic activity. The addition of increasing molar ratios of oleic acid:bovine serum albumin to the media also reduced enzyme activity associated with the endothelial cells. To determine whether the decrease in LPL activity was due to release of the enzyme from the cells or inactivation of the enzyme, studies were performed utilizing radioiodinated bovine LPL. Radiolabeled LPL protein was released from endothelial cells by chylomicrons, VLDL, and by free fatty acids (i.e. oleic acid bound to bovine serum albumin). The release of radiolabeled LPL by VLDL correlated with the generation of free fatty acids from the hydrolysis of VLDL triglyceride by LPL bound to the cells. Inhibition of LPL enzymatic activity by use of a specific monoclonal antibody, reduced the extent of release of 125 I-LPL from the endothelial cells by the added VLDL. These results demonstrated that LPL enzymatic activity and protein were removed from endothelial cells by triglyceride-rich lipoproteins (chylomicrons and VLDL) and oleic acid

  1. Lipoprotein (a) Management: Lifestyle and Hormones.

    Science.gov (United States)

    Garcia-Rios, Antonio; Leon-Acuna, Ana; Lopez-Miranda, Jose; Perez-Martinez, Pablo

    2017-01-01

    Cardiovascular disease (CVD) continues to be the first cause of mortality in developed countries. Moreover, far from diminishing, the cardiovascular risk factors leading towards the development of CVD are on the rise. Therefore, the preventive and therapeutic management which is currently in place is clearly not enough to stop this pandemic. In this context, a major resurgence in interest in lipoprotein (a) [Lp(a)] has occurred in light of its association with CVD. This series aims to review the basic and clinical aspects of Lp(a) biology. Specifically, the present review considers the current situation regarding the influence of lifestyle, hormones and other physiological or pathological conditions on Lp(a) plasma concentrations which might mitigate the harmful effects of this lipoprotein. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  2. Increased transvascular lipoprotein transport in diabetes

    DEFF Research Database (Denmark)

    Jensen, Jan Skov; Feldt-Rasmussen, Bo; Borch-Johnsen, Knut

    2005-01-01

    CONTEXT: Diabetes is associated with a highly increased risk of atherosclerosis, especially if hypertension or albuminuria is present. OBJECTIVE: We hypothesized that the increased transvascular lipoprotein transport in diabetes may be further accelerated if hypertension or albuminuria is present...... of transvascular transport. RESULTS: Transvascular LDL transport was 1.8 (1.6-2.0), 2.3 (2.0-2.6), and 2.6 (1.3-4.0)%/[h x (liter/m2)] in healthy controls, diabetic controls, and diabetes patients with systolic hypertension or albuminuria, respectively (P = 0.013; F = 4.5; df =2; ANOVA). These differences most...... likely were not caused by altered hepatic LDL receptor expression, glycosylation of LDL, small LDL size, or medicine use. CONCLUSIONS: Transvascular LDL transport is increased in patients with diabetes mellitus, especially if systolic hypertension or albuminuria is present. Accordingly, lipoprotein flux...

  3. PKA RIα/A-kinase anchoring proteins 10 signaling pathway and the prognosis of colorectal cancer.

    Science.gov (United States)

    Wang, Mojin; Li, Yuan; Wang, Rui; Wang, Ziqiang; Chen, Keling; Zhou, Bin; Zhou, Zongguang; Sun, Xiaofeng

    2015-03-01

    Previously study showed that the loss of the control of cAMP-dependent protein kinase A RIα (PKA RIα)/ A-kinase anchoring proteins 10 (AKAP10) signaling pathway initiate dysregulation of cellular healthy physiology leading to tumorigenesis. The aim of this study was to investigate the role of PKA RIα/AKAP10 signaling pathway in colorectal cancer (CRC). The AKAP10 expression at the mRNA and protein level have been analyzed in colon cancer cell lines, primary CRCs and matched normal mucosa samples, and compared in accordance with specific clinicopathological features of CRC. The correlation between expression of AKAP10 and PKA RIα were also analyzed. Compared with HCT116 and SW480 cells, the AKAP10 was significantly upregulated in the colon cell line KM12C and its metastatic counterparts, KM12SM and KM12L4A. Moreover, the KM12SM and KM12L4A having high metastatic potentials displayed the elevated levels of AKAP10 compared with KM12C having poor metastatic potential. A notably higher level of AKAP10 expression was found in CRC tissues at both mRNA and protein levels. Increased expression of AKAP10 in CRC patients was positively associated with the depth of invasion and the grade of differentiation. Univariate survival analysis showed that the increased expression of AKAP10 was related to poorer survival. Cox multivariate regression analysis confirmed that AKAP10 was an independent predictor of the overall survival of CRC patients. PKA RIα mRNA was also expressed at high levels in CRC. The correlation coefficient between mRNA expression of AKAP10 and PKA RIα in CRC was 0.417. AKAP10 mRNA overexpression was correlated significantly with PKA RIα. Our data indicated that PKA RIα/AKAP10 signaling pathway is associated with the progression and prognosis of CRC. © 2014 Journal of Gastroenterology and Hepatology Foundation and Wiley Publishing Asia Pty Ltd.

  4. FK506-binding protein 10 (FKBP10) regulates lung fibroblast migration via collagen VI synthesis.

    Science.gov (United States)

    Knüppel, Larissa; Heinzelmann, Katharina; Lindner, Michael; Hatz, Rudolf; Behr, Jürgen; Eickelberg, Oliver; Staab-Weijnitz, Claudia A

    2018-04-19

    In idiopathic pulmonary fibrosis (IPF), fibroblasts gain a more migratory phenotype and excessively secrete extracellular matrix (ECM), ultimately leading to alveolar scarring and progressive dyspnea. Here, we analyzed the effects of deficiency of FK506-binding protein 10 (FKBP10), a potential IPF drug target, on primary human lung fibroblast (phLF) adhesion and migration. Using siRNA, FKBP10 expression was inhibited in phLF in absence or presence of 2ng/ml transforming growth factor-β1 (TGF-β1) and 0.1mM 2-phosphoascorbate. Effects on cell adhesion and migration were monitored by an immunofluorescence (IF)-based attachment assay, a conventional scratch assay, and single cell tracking by time-lapse microscopy. Effects on expression of key players in adhesion dynamics and migration were analyzed by qPCR and Western Blot. Colocalization was evaluated by IF microscopy and by proximity ligation assays. FKBP10 knockdown significantly attenuated adhesion and migration of phLF. Expression of collagen VI was decreased, while expression of key components of the focal adhesion complex was mostly upregulated. The effects on migration were 2-phosphoascorbate-dependent, suggesting collagen synthesis as the underlying mechanism. FKBP10 colocalized with collagen VI and coating culture dishes with collagen VI, and to a lesser extent with collagen I, abolished the effect of FKBP10 deficiency on migration. These findings show, to our knowledge for the first time, that FKBP10 interacts with collagen VI and that deficiency of FKBP10 reduces phLF migration mainly by downregulation of collagen VI synthesis. The results strengthen FKBP10 as an important intracellular regulator of ECM remodeling and support the concept of FKBP10 as drug target in IPF.

  5. Interferon-gamma inducible protein-10 as a potential biomarker in localized scleroderma

    Science.gov (United States)

    2013-01-01

    Introduction The purpose of this study was to evaluate the presence and levels of interferon-gamma inducible protein-10 (IP-10) in the plasma and skin of pediatric localized scleroderma (LS) patients compared to those of healthy pediatric controls and to determine if IP-10 levels correlate to clinical disease activity measures. Methods The presence of IP-10 in the plasma was analyzed using a Luminex panel in 69 pediatric patients with LS and compared to 71 healthy pediatric controls. Of these patients, five had available skin biopsy specimens with concurrent clinical and serological data during the active disease phase, which were used to analyze the presence and location of IP-10 in the skin by immunohistochemistry (IHC). Results IP-10 levels were significantly elevated in the plasma of LS patients compared to that of healthy controls and correlated to clinical disease activity measures in LS. Immunohistochemistry staining of IP-10 was present in the dermal infiltrate of LS patients and was similar to that found in psoriasis skin specimens, the positive disease control. Conclusions Elevation of IP-10 levels in the plasma compared to those of healthy controls and the presence of IP-10 staining in the affected skin of LS patients indicates that IP-10 is a potential biomarker in LS. Furthermore, significant elevation of IP-10 in LS patients with active versus inactive disease and correlations between IP-10 levels and standardized disease outcome measures of activity in LS strongly suggest that IP-10 may be a biomarker for disease activity in LS. PMID:24499523

  6. Analyzing the molecular mechanism of lipoprotein localization in Brucella.

    Science.gov (United States)

    Goolab, Shivani; Roth, Robyn L; van Heerden, Henriette; Crampton, Michael C

    2015-01-01

    Bacterial lipoproteins possess diverse structure and functionality, ranging from bacterial physiology to pathogenic processes. As such many lipoproteins, originating from Brucella are exploited as potential vaccines to countermeasure brucellosis infection in the host. These membrane proteins are translocated from the cytoplasm to the cell membrane where they are anchored peripherally by a multifaceted targeting mechanism. Although much research has focused on the identification and classification of Brucella lipoproteins and their potential use as vaccine candidates for the treatment of Brucellosis, the underlying route for the translocation of these lipoproteins to the outer surface of the Brucella (and other pathogens) outer membrane (OM) remains mostly unknown. This is partly due to the complexity of the organism and evasive tactics used to escape the host immune system, the variation in biological structure and activity of lipoproteins, combined with the complex nature of the translocation machinery. The biosynthetic pathway of Brucella lipoproteins involves a distinct secretion system aiding translocation from the cytoplasm, where they are modified by lipidation, sorted by the lipoprotein localization machinery pathway and thereafter equipped for export to the OM. Surface localized lipoproteins in Brucella may employ a lipoprotein flippase or the β-barrel assembly complex for translocation. This review provides an overview of the characterized Brucella OM proteins that form part of the OM, including a handful of other characterized bacterial lipoproteins and their mechanisms of translocation. Lipoprotein localization pathways in gram negative bacteria will be used as a model to identify gaps in Brucella lipoprotein localization and infer a potential pathway. Of particular interest are the dual topology lipoproteins identified in Escherichia coli and Haemophilus influenza. The localization and topology of these lipoproteins from other gram negative bacteria

  7. Analyzing the molecular mechanism of lipoprotein localization in Brucella

    Science.gov (United States)

    Goolab, Shivani; Roth, Robyn L.; van Heerden, Henriette; Crampton, Michael C.

    2015-01-01

    Bacterial lipoproteins possess diverse structure and functionality, ranging from bacterial physiology to pathogenic processes. As such many lipoproteins, originating from Brucella are exploited as potential vaccines to countermeasure brucellosis infection in the host. These membrane proteins are translocated from the cytoplasm to the cell membrane where they are anchored peripherally by a multifaceted targeting mechanism. Although much research has focused on the identification and classification of Brucella lipoproteins and their potential use as vaccine candidates for the treatment of Brucellosis, the underlying route for the translocation of these lipoproteins to the outer surface of the Brucella (and other pathogens) outer membrane (OM) remains mostly unknown. This is partly due to the complexity of the organism and evasive tactics used to escape the host immune system, the variation in biological structure and activity of lipoproteins, combined with the complex nature of the translocation machinery. The biosynthetic pathway of Brucella lipoproteins involves a distinct secretion system aiding translocation from the cytoplasm, where they are modified by lipidation, sorted by the lipoprotein localization machinery pathway and thereafter equipped for export to the OM. Surface localized lipoproteins in Brucella may employ a lipoprotein flippase or the β-barrel assembly complex for translocation. This review provides an overview of the characterized Brucella OM proteins that form part of the OM, including a handful of other characterized bacterial lipoproteins and their mechanisms of translocation. Lipoprotein localization pathways in gram negative bacteria will be used as a model to identify gaps in Brucella lipoprotein localization and infer a potential pathway. Of particular interest are the dual topology lipoproteins identified in Escherichia coli and Haemophilus influenza. The localization and topology of these lipoproteins from other gram negative bacteria

  8. Lipoprotein lipase deficiency with visceral xanthomas

    Energy Technology Data Exchange (ETDEWEB)

    Servaes, Sabah; Bellah, Richard [Department of Radiology, Philadelphia, PA (United States); Verma, Ritu [Department of Gastroenterology, Philadelphia, PA (United States); Pawel, Bruce [Department of Pathology, Philadelphia, PA (United States)

    2010-08-15

    Lipoprotein lipase deficiency (LLD) is a rare metabolic disorder that typically presents with skin xanthomas and pancreatitis in childhood. We report a case of LLD in an infant who presented with jaundice caused by a pancreatic head mass. Abdominal imaging also incidentally revealed hyperechoic renal masses caused by renal xanthomas. This appearance of the multiple abdominal masses makes this a unique infantile presentation of LLD. (orig.)

  9. Lipoprotein lipase: genetics, lipid uptake, and regulation.

    Science.gov (United States)

    Merkel, Martin; Eckel, Robert H; Goldberg, Ira J

    2002-12-01

    Lipoprotein lipase (LPL) regulates the plasma levels of triglyceride and HDL. Three aspects are reviewed. 1) Clinical implications of human LPL gene variations: common mutations and their effects on plasma lipids and coronary heart disease are discussed. 2) LPL actions in the nervous system, liver, and heart: the discussion focuses on LPL and tissue lipid uptake. 3) LPL gene regulation: the LPL promoter and its regulatory elements are described.

  10. Sortilins: new players in lipoprotein metabolism

    DEFF Research Database (Denmark)

    Willnow, Thomas; Kjølby, Mads Fuglsang; Nykjær, Anders

    2011-01-01

    PURPOSE OF REVIEW: Sortilins are sorting receptors that direct proteins through secretory and endocytic pathways of the cell. Previously, these receptors have been shown to play important roles in regulating protein transport in neurons and to control neuronal viability and death in many diseases...... on the importance of sorting receptors in control of cellular and systemic lipoprotein metabolism and how altered trafficking pathways may represent a major risk factor for dyslipidemia and atherosclerosis in the human population....

  11. Immune Response to Lipoproteins in Atherosclerosis

    Directory of Open Access Journals (Sweden)

    Sonia Samson

    2012-01-01

    Full Text Available Atherosclerosis, the underlying cause of cardiovascular disease, is characterized by chronic inflammation and altered immune response. Cholesterol is a well-known risk factor associated with the development of cardiovascular diseases. Elevated serum cholesterol is unique because it can lead to development of atherosclerosis in animals and humans even in the absence of other risk factors. Modifications of low-density lipoproteins mediated by oxidation, enzymatic degradation, and aggregation result in changes in their function and activate both innate and adaptive immune system. Oxidized low-density lipoprotein (LDL has been identified as one of the most important autoantigens in atherosclerosis. This escape from self-tolerance is dependent on the formation of oxidized phospholipids. The emerging understanding of the importance of immune responses against oxidized LDL in atherosclerosis has focused attention on the possibility of development of novel therapy for atherosclerosis. This review provides an overview of immune response to lipoproteins and the fascinating possibility of developing an immunomodulatory therapy for atherosclerosis.

  12. Maternal-fetal cholesterol transport in the second half ofmouse pregnancy does not involve LDL receptor-related protein 2

    NARCIS (Netherlands)

    Zwier, Mathijs V; Baardman, Maria E; van Dijk, Theo H; Jurdzinski, Angelika; Wisse, Lambertus J; Bloks, Vincent W; Berger, Rolf M F; DeRuiter, Marco C; Groen, Albert K; Plösch, Torsten

    AimLDL receptor-related protein type 2 (LRP2) is highly expressed on both yolk sac and placenta. Mutations in the corresponding gene are associated with severe birth defects in humans, known as Donnai-Barrow syndrome. We here characterized the contribution of LRP2 and maternal plasma cholesterol

  13. Serum and urinary lipoproteins in the human nephrotic syndrome: evidence for renal catabolism of lipoproteins

    Energy Technology Data Exchange (ETDEWEB)

    Shore, V.G.; Forte, T.; Licht, H.; Lewis, S.B.

    1982-03-01

    The urinary excretion of lipoproteins and the possibility of catabolic alterations on glomerular filtration were investigated in four nephrotic subjects difering in etiology, serum lipoprotein profile, and 24 hr urinary output of protein and lipids. The apolipoproteins and lipoproteins of urine were compared with those of serum with respect to distribution profile, physical properties, and composition. As expected from molecular sieving effects during glomerular filtration, the urinary HDL were more abundant than the lower density lipoproteins even when the plasma LDL was elevated markedly. Intact apolipoproteins were not found in the concentrated urinary fraction isolated by ultrafiltration between the limits of 10/sup 4/ and 5 x 10/sup 4/ daltons. On the basis of immunoreactivity, gel electrophoresis, and amino acid composition, apolipoproteins B and AI are the major and minor proteins, respectively, of urinary LDL, and apo B is the major protein of the urinary IDL and VLDL. Apolipoproteins AI, AII, CI, CIII, and possibly AIV were isolated from the urinary HDL. As much as 20% of the protein moiety of the urinary HDL appeared to be large apolipoprotien fragments with molecular weights and isoelectric points similar to those of apo CII and apo CIII. The lower density classes of urinary lipoproteins also appeared to have lost apo E and apo C's and to have undergone partial proteolysis.

  14. Influence of Schistosoma japonicum programmed cell death protein 10 on the growth and development of schistosomula.

    Science.gov (United States)

    Gao, Yan Ru; Huang, Wen Ling; Tang, Chun Lian; Liu, Rong; Zhao, Qin Ping; Ming, Zhen Ping; Dong, Hui Fen

    2018-01-18

    Schistosomiasis caused by Schistosoma japonicum is among the most serious endemic zoonoses in China. To study interactions between schistosomula, the pre-adult juvenile stage, and hosts, it is important to study the functions of key genes involved in schistosomula growth and development. Programmed cell death protein 10 (pcdp10) is an important apoptosis-related gene with various biological functions. This study described the molecular characterization of S. japonicum PCDP10 (SjPCDP10) and evaluated its functions in schistosomula. Real-time quantitative polymerase chain reaction (qPCR) and western blot were used to detect Sjpcdp10 mRNA and protein levels, respectively, at different developmental stages. Immunolocalization was performed to determine SjPCDP10 expression in the parasite. RNA interference (RNAi) experiments were used to assess gene functions associated with SjPCDP10 in schistosomula growth and development. Real-time qPCR revealed that Sjpcdp10 was expressed during all investigated developmental stages and upregulated during schistosomula growth and development. Histochemical localization showed that SjPCDP10 was mainly distributed in the teguments of schistosomula in all investigated stages and part of the parenchymal area of 14-, 18-, and 21-day-old schistosomula. Following Sjpcdp10 knockdown by RNAi, the lengths, widths, areas, and volumes of schistosomula were significantly lower than those in the control group. Scanning electron microscopy showed that the body surfaces of schistosomula subjected to RNAi were seriously damaged, with few tegumental spines and sensory papillae. Transmission electron microscopy indicated that the teguments of Sjpcdp10-knockdown schistosomula were incomplete, the number of layers was reduced, and the thickness decreased significantly as compared with those in the control group. Furthermore, terminal deoxynucleotidyl transferase dUTP nick-end labelling results showed that the rate of apoptosis in Sjpcdp10-knockdown

  15. Site-Directed Mutagenesis of the Fibronectin Domains in Insulin Receptor-Related Receptor

    Directory of Open Access Journals (Sweden)

    Igor E. Deyev

    2017-11-01

    Full Text Available The orphan insulin receptor-related receptor (IRR, in contrast to its close homologs, the insulin receptor (IR and insulin-like growth factor receptor (IGF-IR can be activated by mildly alkaline extracellular medium. We have previously demonstrated that IRR activation is defined by its extracellular region, involves multiple domains, and shows positive cooperativity with two synergistic sites. By the analyses of point mutants and chimeras of IRR with IR in, we now address the role of the fibronectin type III (FnIII repeats in the IRR pH-sensing. The first activation site includes the intrinsically disordered subdomain ID (646–716 within the FnIII-2 domain at the C-terminus of IRR alpha subunit together with closely located residues L135, G188, R244, H318, and K319 of L1 and C domains of the second subunit. The second site involves residue T582 of FnIII-1 domain at the top of IRR lambda-shape pyramid together with M406, V407, and D408 from L2 domain within the second subunit. A possible importance of the IRR carbohydrate moiety for its activation was also assessed. IRR is normally less glycosylated than IR and IGF-IR. Swapping both FnIII-2 and FnIII-3 IRR domains with those of IR shifted beta-subunit mass from 68 kDa for IRR to about 100 kDa due to increased glycosylation and abolished the IRR pH response. However, mutations of four asparagine residues, potential glycosylation sites in chimera IRR with swapped FnIII-2/3 domains of IR, decreased the chimera glycosylation and resulted in a partial restoration of IRR pH-sensing activity, suggesting that the extensive glycosylation of FnIII-2/3 provides steric hindrance for the alkali-induced rearrangement of the IRR ectodomain.

  16. Expression of LDL receptor-related proteins (LRPs in common solid malignancies correlates with patient survival.

    Directory of Open Access Journals (Sweden)

    Steven L Gonias

    Full Text Available LDL receptor-related proteins (LRPs are transmembrane receptors involved in endocytosis, cell-signaling, and trafficking of other cellular proteins. Considerable work has focused on LRPs in the fields of vascular biology and neurobiology. How these receptors affect cancer progression in humans remains largely unknown. Herein, we mined provisional databases in The Cancer Genome Atlas (TCGA to compare expression of thirteen LRPs in ten common solid malignancies in patients. Our first goal was to determine the abundance of LRP mRNAs in each type of cancer. Our second goal was to determine whether expression of LRPs is associated with improved or worsened patient survival. In total, data from 4,629 patients were mined. In nine of ten cancers studied, the most abundantly expressed LRP was LRP1; however, a correlation between LRP1 mRNA expression and patient survival was observed only in bladder urothelial carcinoma. In this malignancy, high levels of LRP1 mRNA were associated with worsened patient survival. High levels of LDL receptor (LDLR mRNA were associated with decreased patient survival in pancreatic adenocarcinoma. High levels of LRP10 mRNA were associated with decreased patient survival in hepatocellular carcinoma, lung adenocarcinoma, and pancreatic adenocarcinoma. LRP2 was the only LRP for which high levels of mRNA expression correlated with improved patient survival. This correlation was observed in renal clear cell carcinoma. Insights into LRP gene expression in human cancers and their effects on patient survival should guide future research.

  17. Effects of aerobic exercise on lipids and lipoproteins.

    Science.gov (United States)

    Wang, Yating; Xu, Danyan

    2017-07-05

    Dyslipidemia is the risk of cardiovascular disease, and their relationship is clear. Lowering serum cholesterol can reduce the risk of coronary heart disease. At present, the main treatment is taking medicine, however, drug treatment has its limitations. Exercise not only has a positive effect on individuals with dyslipidemia, but can also help improve lipids profile. This review is intending to provide information on the effects of exercise training on both tranditional lipids, for example, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglycerides and new lipids and lipoproteins such as non-high-density lipoprotein cholesterol, and postprandial lipoprotein. The mechanisms of aerobic exercise on lipids and lipoproteins are also briefly described.

  18. High Density Lipoprotein and it's Dysfunction.

    Science.gov (United States)

    Eren, Esin; Yilmaz, Necat; Aydin, Ozgur

    2012-01-01

    Plasma high-density lipoprotein cholesterol(HDL-C) levels do not predict functionality and composition of high-density lipoprotein(HDL). Traditionally, keeping levels of low-density lipoprotein cholesterol(LDL-C) down and HDL-C up have been the goal of patients to prevent atherosclerosis that can lead to coronary vascular disease(CVD). People think about the HDL present in their cholesterol test, but not about its functional capability. Up to 65% of cardiovascular death cannot be prevented by putative LDL-C lowering agents. It well explains the strong interest in HDL increasing strategies. However, recent studies have questioned the good in using drugs to increase level of HDL. While raising HDL is a theoretically attractive target, the optimal approach remains uncertain. The attention has turned to the quality, rather than the quantity, of HDL-C. An alternative to elevations in HDL involves strategies to enhance HDL functionality. The situation poses an opportunity for clinical chemists to take the lead in the development and validation of such biomarkers. The best known function of HDL is the capacity to promote cellular cholesterol efflux from peripheral cells and deliver cholesterol to the liver for excretion, thereby playing a key role in reverse cholesterol transport (RCT). The functions of HDL that have recently attracted attention include anti-inflammatory and anti-oxidant activities. High antioxidant and anti-inflammatory activities of HDL are associated with protection from CVD.This review addresses the current state of knowledge regarding assays of HDL functions and their relationship to CVD. HDL as a therapeutic target is the new frontier with huge potential for positive public health implications.

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

    DEFF Research Database (Denmark)

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

    2004-01-01

    Supply of lipids from the mother is essential for fetal growth and development. In mice, disruption of yolk sac cell secretion of apolipoprotein (apo) B-containing lipoproteins results in embryonic lethality. In humans, the yolk sac is vestigial. Nutritional functions are instead established very...... lipoproteins secreted from placental tissue showed spherical particles with a diameter of 47 +/- 10 nm. These results demonstrate that human placenta expresses both apoB and MTP and consequently synthesize and secrete apoB-100-containing lipoproteins. Placental lipoprotein formation constitutes a novel pathway...

  20. Outer membrane lipoprotein biogenesis: Lol is not the end.

    Science.gov (United States)

    Konovalova, Anna; Silhavy, Thomas J

    2015-10-05

    Bacterial lipoproteins are lipid-anchored proteins that contain acyl groups covalently attached to the N-terminal cysteine residue of the mature protein. Lipoproteins are synthesized in precursor form with an N-terminal signal sequence (SS) that targets translocation across the cytoplasmic or inner membrane (IM). Lipid modification and SS processing take place at the periplasmic face of the IM. Outer membrane (OM) lipoproteins take the localization of lipoproteins (Lol) export pathway, which ends with the insertion of the N-terminal lipid moiety into the inner leaflet of the OM. For many lipoproteins, the biogenesis pathway ends here. We provide examples of lipoproteins that adopt complex topologies in the OM that include transmembrane and surface-exposed domains. Biogenesis of such lipoproteins requires additional steps beyond the Lol pathway. In at least one case, lipoprotein sequences reach the cell surface by being threaded through the lumen of a beta-barrel protein in an assembly reaction that requires the heteropentomeric Bam complex. The inability to predict surface exposure reinforces the importance of experimental verification of lipoprotein topology and we will discuss some of the methods used to study OM protein topology. © 2015 The Author(s).

  1. Metabolism of cholesteryl esters of rat very low density lipoproteins.

    Science.gov (United States)

    Faergeman, O; Havel, R J

    1975-06-01

    Rat very low density lipoproteins (d smaller than 1.006), biologically labeled in esterified and free cholesterol, were obtained form serum 6 h after intravenous injection of particulate (3-H) cholesterol. When injected into recipient animals, the esterified cholesterol was cleared form plasma with a half-life of 5 min. After 15 min, 71% of the injected esterified (3-H) cholesterol had been taken up by the liver, where it was rapidly hydrolyzed. After 60 min only 3.3% of the amount injected had been transferred, via lipoproteins of intermediate density, to the low density lipoproteins of plasma (d 1.019-1.063). Both uptake in the liver and transfer to low density lipoproteins occurred without change of distribution of 3-H in the various cholesteryl esters. 3-H appearing in esterified cholesterol of high density lipoproteins (d greater than 1.063) was derived from esterification, presumably by lecithin: cholesterol acyltransferase, of simultaneously injected free (3-H) cholesterol. Content of free (3-H) cholesterol in the very low density lipoproteins used for injection could be reduced substantially by incubation with erythrocytes. This procedure, however, increased the rate of clearance of the lipoproteins after injection into recipient rats. These studies show that hepatic removal is the major catabolic pathway for cholesteryl esters of rat very low density lipoproteins and that transfer to low density lipoproteins occurs to only a minor extent.

  2. Identification of Lipoproteins Using Globomycin and Radioactive Palmitate.

    Science.gov (United States)

    Buddelmeijer, Nienke

    2017-01-01

    Bacterial lipoproteins are characterized by fatty acids that are covalently attached to their amino terminus via posttranslational modification in the cytoplasmic membrane. Three enzymatic steps are involved in the synthesis of mature triacylated lipoprotein: prolipoprotein converts into diacylglyceryl-prolipoprotein that in turn converts into apolipoprotein, which is finally converted into mature triacylated lipoprotein. Here we describe the detection of one of these intermediate forms of lipoprotein, diacylglyceryl-prolipoprotein, using 3 H-palmitate labeling and inhibition by globomycin and detection by fluorography.

  3. Changes in lipoprotein kinetics associated with type 2 diabetes affect the distribution of lipopolysaccharides among lipoproteins.

    Science.gov (United States)

    Vergès, Bruno; Duvillard, Laurence; Lagrost, Laurent; Vachoux, Christelle; Garret, Céline; Bouyer, Karine; Courtney, Michael; Pomié, Céline; Burcelin, Rémy

    2014-07-01

    Lipopolysaccharides (LPSs) are inflammatory components of the outer membrane of Gram-negative bacteria and, in plasma, are mostly associated with lipoproteins. This association is thought to promote their catabolism while reducing their proinflammatory effects. Our aim was to determine the impact of lipoprotein kinetics on plasma LPS distribution and how it may affect patients with type 2 diabetes mellitus (T2DM). We performed a kinetic study in 30 individuals (16 T2DM patients, 14 controls) and analyzed the impact of changes in lipoprotein kinetics on LPS distribution among lipoproteins. Plasma LPS levels in T2DM patients were not different from those in controls, but LPS distribution in the two groups was different. Patients with T2DM had higher LPS-very low-density lipoprotein (VLDL; 31% ± 7% vs 22% ± 11%, P = .002), LPS-high-density lipoprotein (HDL; 29% ± 9% vs 19% ± 10%, P = .015), free (nonlipoprotein bound) LPS (10% ± 4% vs 7% ± 4%, P = .043) and lower LPS-low-density lipoprotein (LDL; 30% ± 13% vs 52% ± 16%, P = .001). In multivariable analysis, VLDL-LPS was associated with HDL-LPS (P < .0001); LDL-LPS was associated with VLDL-LPS (P = .004), and VLDL apolipoprotein (apo) B100 catabolism (P = .002); HDL-LPS was associated with free LPS (P < .0001) and VLDL-LPS (P = .033); free LPS was associated with HDL-LPS (P < .0001). In a patient featuring a dramatic decrease in VLDL catabolism due to apoA-V mutation, LDL-LPS was severely decreased (0.044 EU/mL vs 0.788 EU/mL in controls). The difference between T2DM patients and controls for LDL-LPS fraction was no longer significant after controlling for VLDL apoB100 total fractional catabolic rate. Our data suggest that in humans, free LPS transfers first to HDL and then to VLDL, whereas the LPS-bound LDL fraction is mainly derived from VLDL catabolism; the latter may hence represent a LPS catabolic pathway. T2DM patients show lower LDL-LPS secondary to reduced VLDL catabolism, which may represent an

  4. Lipoprotein glomerulopathy treated with LDL-apheresis (Heparin-induced Extracorporeal Lipoprotein Precipitation system: a case report

    Directory of Open Access Journals (Sweden)

    Rivasi Paolo

    2009-12-01

    Full Text Available Abstract Introduction Lipoprotein glomerulopathy is a glomerulonephritis which was described for the first time by Saito in 1989 and is currently acknowledged as a separate nosological entity. It is histologically characterized by a marked dilatation of the glomerular capillaries and the presence of lipoprotein thrombi in the glomerular lumens. The dyslipidemic profile is similar to that of type III dyslipoproteinemia with Apolipoprotein E values that are often high; proteinuria and renal dysfunction are present. Proteinuria often does not respond to steroid and cytostatic treatments. The phenotypic expression of lipoprotein glomerulopathy is most probably correlated to a genetic alteration of the lipoprotein metabolism (mutation of the Apolipoprotein E coding gene. In literature, lipoprotein glomerulopathies have mainly been reported in Japanese and Chinese subjects, except for three cases in the Caucasian race, reported in France and the USA. Case presentation We describe the case of a 60-year-old female, Caucasian patient suffering from lipoprotein glomerulopathy, carrier of a new mutation on the Apolipoprotein E gene (Apolipoprotein EMODENA, and treated successfully with low density lipoprotein-apheresis with the Heparin induced extracorporeal lipoprotein precipitation system. After a first phase of therapeutic protocol with statins, the patient was admitted for nephrotic syndrome, renal failure and hypertension. Since conventional treatment alone was not able to control dyslipidemia, aphaeretic treatment with heparin-induced Extracorporeal Lipoprotein Precipitation - apheresis (HELP-apheresis was started to maintain angiotensin converting enzyme inhibitor therapy for the treatment of hypertension. Treatment with HELP-apheresis led to a complete remission of the proteinuria in a very short time (four months, as well as control of hypercholesterolemia and renal function recovery. Conclusion According to this case of lipoprotein glomerulopathy

  5. Lipoprotein particle distribution and skeletal muscle lipoprotein lipase activity after acute exercise.

    Science.gov (United States)

    Harrison, Michael; Moyna, Niall M; Zderic, Theodore W; O'Gorman, Donal J; McCaffrey, Noel; Carson, Brian P; Hamilton, Marc T

    2012-07-10

    Many of the metabolic effects of exercise are due to the most recent exercise session. With recent advances in nuclear magnetic resonance spectroscopy (NMRS), it is possible to gain insight about which lipoprotein particles are responsible for mediating exercise effects. Using a randomized cross-over design, very low density lipoprotein (VLDL) responses were evaluated in eight men on the morning after i) an inactive control trial (CON), ii) exercising vigorously on the prior evening for 100 min followed by fasting overnight to maintain an energy and carbohydrate deficit (EX-DEF), and iii) after the same exercise session followed by carbohydrate intake to restore muscle glycogen and carbohydrate balance (EX-BAL). The intermediate, low and high density lipoprotein particle concentrations did not differ between trials. Fasting triglyceride (TG) determined biochemically, and mean VLDL size were lower in EX-DEF but not in EX-BAL compared to CON, primarily due to a reduction in VLDL-TG in the 70-120 nm (large) particle range. In contrast, VLDL-TG was lower in both EX-DEF and EX-BAL compared to CON in the 43-55 nm (medium) particle range. VLDL-TG in smaller particles (29-43 nm) was unaffected by exercise. Because the majority of VLDL particles were in this smallest size range and resistant to change, total VLDL particle concentration was not different between any of these conditions. Skeletal muscle lipoprotein lipase (LPL) activity was also not different across these 3 trials. However, in CON only, the inter-individual differences in LPL activity were inversely correlated with fasting TG, VLDL-TG, total, large and small VLDL particle concentration and VLDL size, indicating a regulatory role for LPL in the non-exercised state. These findings reveal a high level of differential regulation between different sized triglyceride-rich lipoproteins following exercise and feeding, in the absence of changes in LPL activity.

  6. Hydrolysis of diacylglycerols by lipoprotein lipase.

    Science.gov (United States)

    Morley, N H; Kuksis, A; Buchnea, D; Myher, J J

    1975-05-10

    Enantiomeric diacylglycerols were emulsified, mole for mole, with lyso(1-acyl) lecithin and were hydrolyzed with lipoprotein lipase in NH4Cl-beef serum albumin buffer at pH 8.6 after a brief incubation with delipidated rat serum. The enzyme was prepared from lyophilized and dialyzed bovine skim milk in a 4 percent solution. The course of hydrolysis for each set of enantiomers was determined by gas-liquid chromatography of the masses of the diacylglycerols remaining or monoacylglycerols released in the medium between 0 and 15 min. The majority of sets of sn-1,2- and 2,3-diacylglycerols, including an isotope-labeled true enantiomeric set which was assessed by mass spectrometry, demonstrated preference by the enzyme for lipolysis at position 1 but with less specificity than previously was shown in sn-triacylglycerol hydrolysis. The results preclude the possibility that the predominance of sn-2,3-diacylglycerol intermediates during triacylglycerol hydrolysis is due solely to a preferential breakdown of the 1,2-isomers and reinforce the conclusion that lipoprotein lipase is specific for position 1.

  7. Serum lipoproteins attenuate macrophage activation and Toll-Like Receptor stimulation by bacterial lipoproteins

    Directory of Open Access Journals (Sweden)

    James Richard W

    2010-09-01

    Full Text Available Abstract Background Chlamydia trachomatis was previously shown to express a lipoprotein, the macrophage infectivity potentiator (Mip, exposed at the bacterial surface, and able to stimulate human primary monocytes/macrophages through Toll Like Receptor (TLR2/TLR1/TLR6, and CD14. In PMA-differentiated THP-1 cells the proinflammatory activity of Mip was significantly higher in the absence than in the presence of serum. The present study aims to investigate the ability of different serum factors to attenuate Mip proinflammatory activity in PMA-differentiated THP-1 cells and in primary human differentiated macrophages. The study was also extend to another lipoprotein, the Borrelia burgdorferi outer surface protein (OspA. The proinflammatory activity was studied through Tumor Necrosis Factor alpha (TNF-α and Interleukin (IL-8 release. Finally, TLR1/2 human embryonic kidney-293 (HEK-293 transfected cells were used to test the ability of the serum factors to inhibit Mip and OspA proinflammatory activity. Results In the absence of any serum and in the presence of 10% delipidated FBS, production of Mip-induced TNF-α and IL-8 in PMA-differentiated THP-1 cells were similar whereas they were significantly decreased in the presence of 10% FBS suggesting an inhibiting role of lipids present in FBS. In the presence of 10% human serum, the concentrations of TNF-α and IL-8 were 2 to 5 times lower than in the presence of 10% FBS suggesting the presence of more potent inhibitor(s in human serum than in FBS. Similar results were obtained in primary human differentiated macrophages. Different lipid components of human serum were then tested (total lipoproteins, HDL, LDL, VLDL, triglyceride emulsion, apolipoprotein (apoA-I, B, E2, and E3. The most efficient inhibitors were LDL, VLDL, and apoB that reduced the mean concentration of TNF-α release in Mip-induced macrophages to 24, 20, and 2%, respectively (p Conclusions These results demonstrated the ability of

  8. Redefining the essential trafficking pathway for outer membrane lipoproteins

    Science.gov (United States)

    Grabowicz, Marcin; Silhavy, Thomas J.

    2017-01-01

    The outer membrane (OM) of Gram-negative bacteria is a permeability barrier and an intrinsic antibiotic resistance factor. Lipoproteins are OM components that function in cell wall synthesis, diverse secretion systems, and antibiotic efflux pumps. Moreover, each of the essential OM machines that assemble the barrier requires one or more lipoproteins. This dependence is thought to explain the essentiality of the periplasmic chaperone LolA and its OM receptor LolB that traffic lipoproteins to the OM. However, we show that in strains lacking substrates that are toxic when mislocalized, both LolA and LolB can be completely bypassed by activating an envelope stress response without compromising trafficking of essential lipoproteins. We identify the Cpx stress response as a monitor of lipoprotein trafficking tasked with protecting the cell from mislocalized lipoproteins. Moreover, our findings reveal that an alternate trafficking pathway exists that can, under certain conditions, bypass the functions of LolA and LolB, implying that these proteins do not perform any truly essential mechanistic steps in lipoprotein trafficking. Instead, these proteins’ key function is to prevent lethal accumulation of mislocalized lipoproteins. PMID:28416660

  9. Redefining the essential trafficking pathway for outer membrane lipoproteins.

    Science.gov (United States)

    Grabowicz, Marcin; Silhavy, Thomas J

    2017-05-02

    The outer membrane (OM) of Gram-negative bacteria is a permeability barrier and an intrinsic antibiotic resistance factor. Lipoproteins are OM components that function in cell wall synthesis, diverse secretion systems, and antibiotic efflux pumps. Moreover, each of the essential OM machines that assemble the barrier requires one or more lipoproteins. This dependence is thought to explain the essentiality of the periplasmic chaperone LolA and its OM receptor LolB that traffic lipoproteins to the OM. However, we show that in strains lacking substrates that are toxic when mislocalized, both LolA and LolB can be completely bypassed by activating an envelope stress response without compromising trafficking of essential lipoproteins. We identify the Cpx stress response as a monitor of lipoprotein trafficking tasked with protecting the cell from mislocalized lipoproteins. Moreover, our findings reveal that an alternate trafficking pathway exists that can, under certain conditions, bypass the functions of LolA and LolB, implying that these proteins do not perform any truly essential mechanistic steps in lipoprotein trafficking. Instead, these proteins' key function is to prevent lethal accumulation of mislocalized lipoproteins.

  10. TRIIODOTHYRONINE RAPIDLY LOWERS PLASMA-LIPOPROTEIN (A) IN HYPOTHYROID SUBJECTS

    NARCIS (Netherlands)

    DULLAART, RPF; VANDOORMAAL, JJ; HOOGENBERG, K; SLUITER, WJ

    Background: Increases in plasma low-density-lipoprotein (LDL) cholesterol and apolipoprotein B (apo-B) are well known in primary hypothyroidism, but it is uncertain whether thyroid dysfunction is associated with elevated levels of the atherogenic lipoprotein (a) (Lp(a)). Methods: The effect of

  11. Prediction of lipoprotein signal peptides in Gram-negative bacteria

    DEFF Research Database (Denmark)

    Juncker, Agnieszka; Willenbrock, Hanni; Von Heijne, G.

    2003-01-01

    A method to predict lipoprotein signal peptides in Gram-negative Eubacteria, LipoP, has been developed. The hidden Markov model (HMM) was able to distinguish between lipoproteins (SPaseII-cleaved proteins), SPaseI-cleaved proteins, cytoplasmic proteins, and transmembrane proteins. This predictor ...

  12. A Phospholipidomic Analysis of All Defined Human Plasma Lipoproteins

    NARCIS (Netherlands)

    Dashti, Monireh; Kulik, Willem; Hoek, Frans; Veerman, Enno C.; Peppelenbosch, Maikel P.; Rezaee, Farhad

    2011-01-01

    Since plasma lipoproteins contain both protein and phospholipid components, either may be involved in processes such as atherosclerosis. In this study the identification of plasma lipoprotein-associated phospholipids, which is essential for understanding these processes at the molecular level, are

  13. A phospholipidomic analysis of all defined human plasma lipoproteins

    NARCIS (Netherlands)

    Dashti, Monireh; Kulik, Willem; Hoek, Frans; Veerman, Enno C.; Peppelenbosch, Maikel P.; Rezaee, Farhad

    2011-01-01

    Since plasma lipoproteins contain both protein and phospholipid components, either may be involved in processes such as atherosclerosis. In this study the identification of plasma lipoprotein-associated phospholipids, which is essential for understanding these processes at the molecular level, are

  14. The Influence of Decreased Levels of High Density Lipoprotein ...

    African Journals Online (AJOL)

    Background: Changes in lipoproteins levels in sickle cell disease (SCD) patients are well.known, but the physiological ramifications of the low levels observed have not been entirely resolved. Aim: The aim of this study is to evaluate the impact of decreased levels of high density lipoprotein cholesterol (HDL.c) on ...

  15. Effect of Ascorbic Acid on Lipoprotein Lipase Activity | Kotze | South ...

    African Journals Online (AJOL)

    Baboons kept on hypovitaminotic C diets, but without clinical signs of scurvy, had significantly higher heart muscle lipoprotein lipase activity than baboons on vitamin C 34 mg/kg body mass/day. When the serum vitamin C levels were above 0,35 mg/100 ml the heart muscle lipoprotein lipase was repressed. Serum vitamin C ...

  16. A clustering analysis of lipoprotein diameters in the metabolic syndrome

    Science.gov (United States)

    The presence of smaller low-density lipoproteins (LDL) has been associated with atherosclerosis risk, and the insulin resistance (IR) underlying the metabolic syndrome (MetS). In addition, some research has supported the association of very low-, low- and high-density lipoprotein (VLDL HDL) particle...

  17. DMPD: Lipoprotein trafficking in vascular cells. Molecular Trojan horses and cellularsaboteurs. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 9287290 Lipoprotein trafficking in vascular cells. Molecular Trojan horses and cell...ml) Show Lipoprotein trafficking in vascular cells. Molecular Trojan horses and cellularsaboteurs. PubmedID ...9287290 Title Lipoprotein trafficking in vascular cells. Molecular Trojan horses

  18. Nanotechnology for Synthetic High Density Lipoproteins

    Science.gov (United States)

    Luthi, Andrea J.; Patel, Pinal C.; Ko, Caroline H.; Mutharasan, R. Kannan; Mirkin, Chad A.; Thaxton, C. Shad

    2014-01-01

    Atherosclerosis is the disease mechanism responsible for coronary heart disease (CHD), the leading cause of death worldwide. One strategy to combat atherosclerosis is to increase the amount of circulating high density lipoproteins (HDL), which transport cholesterol from peripheral tissues to the liver for excretion. The process, known as reverse cholesterol transport, is thought to be one of the main reasons for the significant inverse correlation observed between HDL blood levels and the development of CHD. This article highlights the most common strategies for treating atherosclerosis using HDL. We further detail potential treatment opportunities that utilize nanotechnology to increase the amount of HDL in circulation. The synthesis of biomimetic HDL nanostructures that replicate the chemical and physical properties of natural HDL provides novel materials for investigating the structure-function relationships of HDL and for potential new therapeutics to combat CHD. PMID:21087901

  19. Alterations of serum cholesterol and serum lipoprotein in breast cancer of women

    OpenAIRE

    Hasija, Kiran; Bagga, Hardeep K.

    2005-01-01

    Fasting blood sample of 50 normal subjects (control) and 100 patients of breast cancer were investigated for serum total cholesterol, high density lipoprotein cholesterol, low density lipoprotein cholesterol, very low density lipoprotein, high density lipoprotein cholesterol:low density lipoprotein cholesterol ratio and total cholesterol:high density lipoprotein cholesterol ratio during breast cancer of women. Five cancer stages, types, age groups, parity and menopausal status were undertaken...

  20. The fibrate drug gemfibrozil disrupts lipoprotein metabolism in rainbow trout

    International Nuclear Information System (INIS)

    Prindiville, John S.; Mennigen, Jan A.; Zamora, Jake M.; Moon, Thomas W.; Weber, Jean-Michel

    2011-01-01

    Gemfibrozil (GEM) is a fibrate drug consistently found in effluents from sewage treatment plants. This study characterizes the pharmacological effects of GEM on the plasma lipoproteins of rainbow trout (Oncorhynchus mykiss). Our goals were to quantify the impact of the drug on: 1) lipid constituents of lipoproteins (phospholipids (PL), triacylglycerol (TAG), and cholesterol), 2) lipoprotein classes (high, low and very low density lipoproteins), and 3) fatty acid composition of lipoproteins. Potential mechanisms of GEM action were investigated by measuring lipoprotein lipase activity (LPL) and the hepatic gene expression of LPL and of the peroxisome proliferator-activated receptor (PPAR) α, β, and γ isoforms. GEM treatment resulted in decreased plasma lipoprotein levels (- 29%) and a reduced size of all lipoprotein classes (lower PL:TAG ratios). However, the increase in HDL-cholesterol elicited by GEM in humans failed to be observed in trout. Therefore, HDL-cholesterol cannot be used to assess the impact of the drug on fish. GEM also modified lipoprotein composition by reducing the abundance of long-chain n-3 fatty acids, thereby potentially reducing the nutritional quality of exposed fish. The relative gene expression of LPL was increased, but the activity of the enzyme was not, and we found no evidence for the activation of PPAR pathways. The depressing effects of GEM on fish lipoproteins demonstrated here may be a concern in view of the widespread presence of fibrates in aquatic environments. Work is needed to test whether exposure to environmental concentrations of these drugs jeopardizes the capacity of fish for reproduction, temperature acclimation or migratory behaviors.

  1. Effect of high density lipoproteins on permeability of rabbit aorta to low density lipoproteins

    International Nuclear Information System (INIS)

    Klimov, A.N.; Popov, V.A.; Nagornev, V.A.; Pleskov, V.M.

    1985-01-01

    A study was made on the effect of high density lipoproteins (HDL) on the permeability of rabbit aorta to low density lipoproteins (LDL) after intravenous administration of human HDL and human ( 125 I)LDL to normal and hypercholesterolemic rabbits. Evaluation of radioactivity in plasma and aorta has shown that the administration of a large dose of HDL decreased the aorta permeability rate for ( 125 I)LDL on an average by 19% in normal rabbits, and by 45% in rabbits with moderate hypercholesterolemia. A historadiographic study showed that HDL also decreased the vessel wall permeability to ( 125 I)LDL in normal and particularly in hypercholesterolemic animals. The suggestion was made that HDL at very high molar concentration can hamper LDL transportation through the intact endothelial layer into the intima due to the ability of HDL to compete with LDL in sites of low affinity on the surface of endothelial cells. (author)

  2. Transfer of plasma lipoprotein components and of plasma proteins into aortas of cholesterol-fed rabbits. Molecular size as a determinant of plasma lipoprotein influx

    International Nuclear Information System (INIS)

    Stender, S.; Zilversmit, D.B.

    1981-01-01

    The arterial influx of esterified and free cholesterol from low density lipoproteins and very low density lipoproteins in 20 hypercholesterolemic rabbits was measured simultaneously by the use of lipoproteins labeled in vivo with [ 3 H]- and [ 14 C]-cholesterol. The simultaneous arterial influx of either [ 3 H]-leucine-labeled very low density lipoproteins, low density lipoproteins, high density lipoproteins, or plasma proteins was also measured in each rabbit. The arterial influx was calculated as intimal clearance, i.e., the influx of a given fraction divided by its plasma concentration. The intimal clearance of low density lipoprotein esterified cholesterol was equal to that for the apolipoproteins of that fraction, which is compatible with an arterial influx of intact low density lipoprotein molecules. The intimal clearance of very low density apolipoprotein or cholesteryl ester was less than that for low density lipoprotein, whereas high density lipoprotein and albumin clearances exceeded low density lipoprotein clearance by 1.5- to 3-fold. The intimal clearances of plasma proteins, high density, low density, and very low density lipoproteins decreased linearly with the logarithm of the macromolecular diameter. This indicates that the arterial influx of three plasma lipoprotein fractions and of plasma proteins proceeds by similar mechanisms. Apparently the relative intimal clearances of lipoproteins are more dependent on their size relative to pores or vesicular diameters at the plasma-artery interface than on specific interactions between lipoproteins and the arterial intimal surface

  3. Triglycerides, total cholesterol, high density lipoprotein cholesterol and low density lipoprotein cholesterol in rats exposed to premium motor spirit fumes.

    Science.gov (United States)

    Aberare, Ogbevire L; Okuonghae, Patrick; Mukoro, Nathaniel; Dirisu, John O; Osazuwa, Favour; Odigie, Elvis; Omoregie, Richard

    2011-06-01

    Deliberate and regular exposure to premium motor spirit fumes is common and could be a risk factor for liver disease in those who are occupationally exposed. A possible association between premium motor spirit fumes and plasma levels of triglyceride, total cholesterol, high density lipoprotein cholesterol and low density lipoprotein cholesterol using a rodent model could provide new insights in the pathology of diseases where cellular dysfunction is an established risk factor. The aim of this study was to evaluate the possible effect of premium motor spirit fumes on lipids and lipoproteins in workers occupationally exposed to premium motor spirit fumes using rodent model. Twenty-five Wister albino rats (of both sexes) were used for this study between the 4(th) of August and 7(th) of September, 2010. The rats were divided into five groups of five rats each. Group 1 rats were not exposed to premium motor spirit fumes (control group), group 2 rats were exposed for 1 hour daily, group 3 for 3 hours daily, group 4 for 5 hours daily and group 5 for 7 hours daily. The experiment lasted for a period of 4 weeks. Blood samples obtained from all the groups after 4 weeks of exposure were used for the estimation of plasma levels of triglyceride, total cholesterol, high density lipoprotein- cholesterol and low density lipoprotein- cholesterol. Results showed significant increase in means of plasma total cholesterol and low density lipoprotein levels (P<0.05). The mean triglyceride and total body weight were significantly lower (P<0.05) in the exposed group when compared with the unexposed. The plasma level of high density lipoprotein, the ratio of low density lipoprotein to high density lipoprotein and the ratio of total cholesterol to high density lipoprotein did not differ significantly in exposed subjects when compared with the control group. These results showed that frequent exposure to petrol fumes may be highly deleterious to the liver cells.

  4. Lipoprotein particle distribution and skeletal muscle lipoprotein lipase activity after acute exercise

    LENUS (Irish Health Repository)

    Harrison, Michael

    2012-06-06

    AbstractBackgroundMany of the metabolic effects of exercise are due to the most recent exercise session. With recent advances in nuclear magnetic resonance spectroscopy (NMRS), it is possible to gain insight about which lipoprotein particles are responsible for mediating exercise effects.MethodsUsing a randomized cross-over design, very low density lipoprotein (VLDL) responses were evaluated in eight men on the morning after i) an inactive control trial (CON), ii) exercising vigorously on the prior evening for 100 min followed by fasting overnight to maintain an energy and carbohydrate deficit (EX-DEF), and iii) after the same exercise session followed by carbohydrate intake to restore muscle glycogen and carbohydrate balance (EX-BAL).ResultsThe intermediate, low and high density lipoprotein particle concentrations did not differ between trials. Fasting triglyceride (TG) determined biochemically, and mean VLDL size were lower in EX-DEF but not in EX-BAL compared to CON, primarily due to a reduction in VLDL-TG in the 70–120 nm (large) particle range. In contrast, VLDL-TG was lower in both EX-DEF and EX-BAL compared to CON in the 43–55 nm (medium) particle range. VLDL-TG in smaller particles (29–43 nm) was unaffected by exercise. Because the majority of VLDL particles were in this smallest size range and resistant to change, total VLDL particle concentration was not different between any of these conditions. Skeletal muscle lipoprotein lipase (LPL) activity was also not different across these 3 trials. However, in CON only, the inter-individual differences in LPL activity were inversely correlated with fasting TG, VLDL-TG, total, large and small VLDL particle concentration and VLDL size, indicating a regulatory role for LPL in the non-exercised state.ConclusionsThese findings reveal a high level of differential regulation between different sized triglyceride-rich lipoproteins following exercise and feeding, in the absence of changes in LPL activity.

  5. Lipoprotein particle distribution and skeletal muscle lipoprotein lipase activity after acute exercise

    Directory of Open Access Journals (Sweden)

    Harrison Michael

    2012-07-01

    Full Text Available Abstract Background Many of the metabolic effects of exercise are due to the most recent exercise session. With recent advances in nuclear magnetic resonance spectroscopy (NMRS, it is possible to gain insight about which lipoprotein particles are responsible for mediating exercise effects. Methods Using a randomized cross-over design, very low density lipoprotein (VLDL responses were evaluated in eight men on the morning after i an inactive control trial (CON, ii exercising vigorously on the prior evening for 100 min followed by fasting overnight to maintain an energy and carbohydrate deficit (EX-DEF, and iii after the same exercise session followed by carbohydrate intake to restore muscle glycogen and carbohydrate balance (EX-BAL. Results The intermediate, low and high density lipoprotein particle concentrations did not differ between trials. Fasting triglyceride (TG determined biochemically, and mean VLDL size were lower in EX-DEF but not in EX-BAL compared to CON, primarily due to a reduction in VLDL-TG in the 70–120 nm (large particle range. In contrast, VLDL-TG was lower in both EX-DEF and EX-BAL compared to CON in the 43–55 nm (medium particle range. VLDL-TG in smaller particles (29–43 nm was unaffected by exercise. Because the majority of VLDL particles were in this smallest size range and resistant to change, total VLDL particle concentration was not different between any of these conditions. Skeletal muscle lipoprotein lipase (LPL activity was also not different across these 3 trials. However, in CON only, the inter-individual differences in LPL activity were inversely correlated with fasting TG, VLDL-TG, total, large and small VLDL particle concentration and VLDL size, indicating a regulatory role for LPL in the non-exercised state. Conclusions These findings reveal a high level of differential regulation between different sized triglyceride-rich lipoproteins following exercise and feeding, in the absence of changes in

  6. IS LIPOPROTEIN (A A PREDICTOR OF CORONARY ARTERY DISEASE SEVERITY?

    Directory of Open Access Journals (Sweden)

    Tayyebeh Miandoabi

    2010-12-01

    Full Text Available Abstract    INTRODUCTION: Studies on the association between the plasma concentration of lipoprotein (a and coronary heart disease (CHD have reported conflicting findings.    METHOD AND MATERIALS: The objective of the present study was to evaluate the association between serum levels of lipoprotein (a and ischemic heart disease as well as other cardiovascular risk factors in a population-based study. Lipoprotein (a serum was measured in 142 patients with chronic stable angina undergoing clinically indicated coronary angiography. Lipid profile, fasting blood glucose, anthropometric and clinical parameters were analyzed.    RESULTS: Lipoprotein (a levels were significantly associated with coronary artery stenosis in men, but not in women. Also, an direct association between mean levels of lipoprotein (a and coronary artery stenosis in men younger than 55 years old and an inverse association in men older than 55 years old were observed.     CONCLUSION: Multivariate analysis revealed that lipoprotein (a was considered an independent predictor for severity of CAD in men, especially in younger ages.      Keywords: Lipoprotein (a, cardiovascular risk factors, Ischemic heart disease, coronary angiography.

  7. Genetics of Lipid and Lipoprotein Disorders and Traits.

    Science.gov (United States)

    Dron, Jacqueline S; Hegele, Robert A

    2016-01-01

    Plasma lipids, namely cholesterol and triglyceride, and lipoproteins, such as low-density lipoprotein (LDL) and high-density lipoprotein, serve numerous physiological roles. Perturbed levels of these traits underlie monogenic dyslipidemias, a diverse group of multisystem disorders. We are on the verge of having a relatively complete picture of the human dyslipidemias and their components. Recent advances in genetics of plasma lipids and lipoproteins include the following: (1) expanding the range of genes causing monogenic dyslipidemias, particularly elevated LDL cholesterol; (2) appreciating the role of polygenic effects in such traits as familial hypercholesterolemia and combined hyperlipidemia; (3) accumulating a list of common variants that determine plasma lipids and lipoproteins; (4) applying exome sequencing to identify collections of rare variants determining plasma lipids and lipoproteins that via Mendelian randomization have also implicated gene products such as NPC1L1 , APOC3 , LDLR , APOA5 , and ANGPTL4 as causal for atherosclerotic cardiovascular disease; and (5) using naturally occurring genetic variation to identify new drug targets, including inhibitors of apolipoprotein (apo) C-III, apo(a), ANGPTL3, and ANGPTL4. Here, we compile this disparate range of data linking human genetic variation to plasma lipids and lipoproteins, providing a "one stop shop" for the interested reader.

  8. The Acylation State of Surface Lipoproteins of Mollicute Acholeplasma laidlawii*

    Science.gov (United States)

    Serebryakova, Marina V.; Demina, Irina A.; Galyamina, Maria A.; Kondratov, Ilya G.; Ladygina, Valentina G.; Govorun, Vadim M.

    2011-01-01

    Acylation of the N-terminal Cys residue is an essential, ubiquitous, and uniquely bacterial posttranslational modification that allows anchoring of proteins to the lipid membrane. In Gram-negative bacteria, acylation proceeds through three sequential steps requiring lipoprotein diacylglyceryltransferase, lipoprotein signal peptidase, and finally lipoprotein N-acyltransferase. The apparent lack of genes coding for recognizable homologs of lipoprotein N-acyltransferase in Gram-positive bacteria and Mollicutes suggests that the final step of the protein acylation process may be absent in these organisms. In this work, we monitored the acylation state of eight major lipoproteins of the mollicute Acholeplasma laidlawii using a combination of standard two-dimensional gel electrophoresis protein separation, blotting to nitrocellulose membranes, and MALDI-MS identification of modified N-terminal tryptic peptides. We show that for each A. laidlawii lipoprotein studied a third fatty acid in an amide linkage on the N-terminal Cys residue is present, whereas diacylated species were not detected. The result thus proves that A. laidlawii encodes a lipoprotein N-acyltransferase activity. We hypothesize that N-acyltransferases encoded by genes non-homologous to N-acyltransferases of Gram-negative bacteria are also present in other mollicutes and Gram-positive bacteria. PMID:21540185

  9. Cholesterol synthesis by human fetal hepatocytes: effect of lipoproteins

    International Nuclear Information System (INIS)

    Carr, B.R.; Simpson, E.R.

    1984-01-01

    The purpose of the present investigation was to determine the effect of various lipoproteins on the rate of cholesterol synthesis of human fetal liver cells maintained in culture. This was accomplished by measuring the rate of incorporation of tritium from tritiated water or carbon 14-labeled acetate into cholesterol in human fetal liver cells. Optimal conditions for each assay were determined. When human fetal liver cells were maintained in the presence of low-density lipoprotein, cholesterol synthesis was inhibited in a concentration-dependent fashion. Intermediate--density lipoprotein and very-low-density lipoprotein also suppressed cholesterol synthesis in human fetal liver cells. In contrast, high-density lipoprotein stimulated cholesterol synthesis in human fetal liver cells. The results of the present as well as our previous investigations suggest that multiple interrelationships exist between fetal liver cholesterol synthesis and lipoprotein-cholesterol utilization by the human fetal adrenal gland and that these processes serve to regulate the lipoprotein-cholesterol levels in fetal plasma

  10. Redefining the essential trafficking pathway for outer membrane lipoproteins

    OpenAIRE

    Grabowicz, Marcin; Silhavy, Thomas J.

    2017-01-01

    In Gram-negative bacteria, most lipoproteins synthesized in the inner membrane (IM) are trafficked to the outer membrane (OM). The Lol pathway is the trafficking paradigm: LolCDE releases lipoproteins from the IM; LolA shuttles them between membranes to LolB in the OM. Several OM lipoproteins are essential for viability. In apparent concordance, the Lol proteins are each essential in wild-type cells. However, we show that Escherichia coli grows well without LolA and LolB in the absence of one...

  11. Hepatitis C virus relies on lipoproteins for its life cycle.

    Science.gov (United States)

    Grassi, Germana; Di Caprio, Giorgia; Fimia, Gian Maria; Ippolito, Giuseppe; Tripodi, Marco; Alonzi, Tonino

    2016-02-14

    Hepatitis C virus (HCV) infects over 150 million people worldwide. In most cases, HCV infection becomes chronic causing liver disease ranging from fibrosis to cirrhosis and hepatocellular carcinoma. Viral persistence and pathogenesis are due to the ability of HCV to deregulate specific host processes, mainly lipid metabolism and innate immunity. In particular, HCV exploits the lipoprotein machineries for almost all steps of its life cycle. The aim of this review is to summarize current knowledge concerning the interplay between HCV and lipoprotein metabolism. We discuss the role played by members of lipoproteins in HCV entry, replication and virion production.

  12. High-density lipoprotein cholesterol: How High

    Directory of Open Access Journals (Sweden)

    G Rajagopal

    2012-01-01

    Full Text Available The high-density lipoprotein cholesterol (HDL-C is considered anti-atherogenic good cholesterol. It is involved in reverse transport of lipids. Epidemiological studies have found inverse relationship of HDL-C and coronary heart disease (CHD risk. When grouped according to HDL-C, subjects having HDL-C more than 60 mg/dL had lesser risk of CHD than those having HDL-C of 40-60 mg/dL, who in turn had lesser risk than those who had HDL-C less than 40 mg/dL. No upper limit for beneficial effect of HDL-C on CHD risk has been identified. The goals of treating patients with low HDL-C have not been firmly established. Though many drugs are known to improve HDL-C concentration, statins are proven to improve CHD risk and mortality. Cholesteryl ester transfer protein (CETP is involved in metabolism of HDL-C and its inhibitors are actively being screened for clinical utility. However, final answer is still awaited on CETP-inhibitors.

  13. Low-Density Lipoproteins Oxidation and Endometriosis

    Directory of Open Access Journals (Sweden)

    Grzegorz Polak

    2013-01-01

    Full Text Available The etiopathogenesis of endometriosis still remains unknown. Recent data provide new valuable information concerning the role of oxidative stress in the pathophysiology of the disease. It has been proved that levels of different lipid peroxidation end products are increased in both peritoneal fluid (PF and serum of endometriotic patients. We assessed the concentration of oxidized low-density lipoproteins (oxLDL in PF of 110 women with different stages of endometriosis and 119 women with serous ( or dermoid ( ovarian cysts, as the reference groups. PF oxLDL levels were evaluated by ELISA. We found that concentrations of oxLDL in PF of endometriotic women were significantly higher compared to women with serous but not dermoid ovarian cysts. Interestingly, by analyzing concentrations of oxLDL in women with different stages of the disease, it was noted that they are significantly higher only in the subgroup of patients with stage IV endometriosis as compared to women with ovarian serous cysts. In case of minimal, mild, and moderate disease, PF oxLDL levels were similar to those noted in reference groups. Our results indicate that disrupted oxidative status in the peritoneal cavity of women with endometriosis may play a role in the pathogenesis of advanced stages of the disease.

  14. Lipoprotein(a in Cardiovascular Diseases

    Directory of Open Access Journals (Sweden)

    Michele Malaguarnera

    2013-01-01

    Full Text Available Lipoprotein(a (Lp(a is an LDL-like molecule consisting of an apolipoprotein B-100 (apo(B-100 particle attached by a disulphide bridge to apo(a. Many observations have pointed out that Lp(a levels may be a risk factor for cardiovascular diseases. Lp(a inhibits the activation of transforming growth factor (TGF and contributes to the growth of arterial atherosclerotic lesions by promoting the proliferation of vascular smooth muscle cells and the migration of smooth muscle cells to endothelial cells. Moreover Lp(a inhibits plasminogen binding to the surfaces of endothelial cells and decreases the activity of fibrin-dependent tissue-type plasminogen activator. Lp(a may act as a proinflammatory mediator that augments the lesion formation in atherosclerotic plaques. Elevated serum Lp(a is an independent predictor of coronary artery disease and myocardial infarction. Furthermore, Lp(a levels should be a marker of restenosis after percutaneous transluminal coronary angioplasty, saphenous vein bypass graft atherosclerosis, and accelerated coronary atherosclerosis of cardiac transplantation. Finally, the possibility that Lp(a may be a risk factor for ischemic stroke has been assessed in several studies. Recent findings suggest that Lp(a-lowering therapy might be beneficial in patients with high Lp(a levels. A future therapeutic approach could include apheresis in high-risk patients in order to reduce major coronary events.

  15. Transport of lipoprotein lipase across endothelial cells

    International Nuclear Information System (INIS)

    Saxena, U.; Klein, M.G.; Goldberg, I.J.

    1991-01-01

    Lipoprotein lipase (LPL), synthesized in muscle and fat, hydrolyzes plasma triglycerides primarily while bound to luminal endothelial cell surfaces. To obtain information about the movement of LPL from the basal to the luminal endothelial cell surface, the authors studied the transport of purified bovine milk LPL across bovine aortic endothelial cell monolayers. 125 I-labeled LPL ( 125 I-LPL) added to the basal surface of the monolayers was detected on the apical side of the cells in two compartments: (1) in the medium of the upper chamber, and (2) bound to the apical cell surface. The amount of 125 I-LPL on the cell surface, but not in the medium, reached saturation with time and LPL dose. Catalytically active LPL was transported to the apical surface but very little LPL activity appeared in the medium. Heparinase treatment of the basal cell surface and addition of dextran sulfate to the lower chamber decreased the amount of 125 I-LPL appearing on the apical surface. Similarly, the presence of increasing molar ratios of oleic acid/bovine serum albumin at the basal surface decreased the transport of active LPL across the monolayer. Thus, a saturable transport system, which requires haparan sulfate proteoglycans and is inhibited by high concentrations of free fatty acids on the basal side of the cells, appears to exist for passage of enzymatically active LPL across endothelial cells. They postulate that regulation of LPL transport to the endothelial luminal surface modulates the physiologically active pool of LPL in vivo

  16. Neisserial surface lipoproteins: structure, function and biogenesis.

    Science.gov (United States)

    Hooda, Yogesh; Shin, Hyejin E; Bateman, Thomas J; Moraes, Trevor F

    2017-03-01

    The surface of many Gram-negative bacteria contains lipidated protein molecules referred to as surface lipoproteins or SLPs. SLPs play critical roles in host immune evasion, nutrient acquisition and regulation of the bacterial stress response. The focus of this review is on the SLPs present in Neisseria, a genus of bacteria that colonise the mucosal surfaces of animals. Neisseria contains two pathogens of medical interest, namely Neisseria meningitidis and N. gonorrhoeae. Several SLPs have been identified in Neisseria and their study has elucidated key strategies used by these pathogens to survive inside the human body. Herein, we focus on the identification, structure and function of SLPs that have been identified in Neisseria. We also survey the translocation pathways used by these SLPs to reach the cell surface. Specifically, we elaborate on the strategies used by neisserial SLPs to translocate across the outer membrane with an emphasis on Slam, a novel outer membrane protein that has been implicated in SLP biogenesis. Taken together, the study of SLPs in Neisseria illustrates the widespread roles played by this family of proteins in Gram-negative bacteria. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  17. Novel Therapies Focused on the High-Density Lipoprotein Particle

    NARCIS (Netherlands)

    van Capelleveen, Julian C.; Brewer, H. Bryan; Kastelein, John J. P.; Hovingh, G. Kees

    2014-01-01

    Cardiovascular disease (CVD) remains a major burden for morbidity and mortality in the general population, despite current efficacious low-density lipoprotein-cholesterol-lowering therapies. Consequently, novel therapies are required to reduce this residual risk. Prospective epidemiological studies

  18. Lipoprotein lipase gene variants: Association with acute myocardial ...

    African Journals Online (AJOL)

    Mahyar Bahrami

    2015-05-13

    May 13, 2015 ... ated with acute myocardial infarction but with triglyceride levels. У 2015 The ... C) and low levels of high-density lipoprotein cholesterol. (HDL-C) are .... relationship between LDL, HDL, cholesterol and TG levels with LPL ...

  19. Unfavorable apoAI-containing lipoproteins profile in Tunisian obese ...

    African Journals Online (AJOL)

    hope&shola

    1Ecole Supérieure des Sciences et Techniques De la Santé, Sfax, Tunisia. 2Laboratoire de Génie Enzymatique ... lipoproteins metabolism. Control and obese women ... cholesteryl ester transfer protein; CHD, coronary heart disease. studied.

  20. Could Lipoprotein Lipase Play a Role in Alzheimer's Disease?

    Directory of Open Access Journals (Sweden)

    Jean-Francois Blain

    2004-01-01

    Full Text Available This paper reviews recent literature on the role of lipoprotein lipase in the central nervous system with a focus on its recently described role in synaptic remodeling. This novel role could have implication for Alzheimer's disease treatment.

  1. Oxidized low-density lipoprotein in postmenopausal women

    DEFF Research Database (Denmark)

    Jankowski, Vera; Just, Alexander R; Pfeilschifter, Johannes

    2014-01-01

    BACKGROUND: Oxidized low-density lipoprotein (oxLDL) leads to atherosclerosis and cardiovascular disease, the most frequent causes of death worldwide. After menopause, lipid and lipoprotein metabolism changes and women are at greater risk of cardiovascular disease compared to fertile women. The aim.......10-0.43). Although intima-media thickness did not differ, postmenopausal women with serous oxLDL had more often atherosclerotic plaques compared to women without oxLDL (6/66 vs. 0/467; P lipoprotein, impaired glucose intolerance, and DBP were independently associated...... with the occurrence of oxLDL. If oxLDL was present, higher high-density lipoprotein and glucose intolerance were associated with higher concentrations of oxLDL. In contrast, higher blood urea concentrations were associated with lower concentrations of oxLDL. CONCLUSION: This study presents the prevalence...

  2. Sex, plasma lipoproteins, and atherosclerosis: prevailing assumptions and outstanding questions.

    Science.gov (United States)

    Godsland, I F; Wynn, V; Crook, D; Miller, N E

    1987-12-01

    We review the hypothesis that the incidence of coronary heart disease (CHD) is higher in men than in women due to differences in plasma lipoprotein risk factors between the sexes. Men and women appear to be equally susceptible to the effects of lipoprotein risk factors for CHD, and the difference between the sexes in lipoprotein risk factors for CHD appears to be consistent with their being, at least in part, responsible for the sex difference in CHD. This is apparent both when men and women of equal age are compared, and when age-related variations in the sex differences in plasma lipoproteins and CHD are considered. Differences between the sexes in lipoprotein concentrations are still present when sex differences in adiposity, cigarette smoking, physical activity, and diet are taken into account. Evidence relating these sex differences in CHD and lipoproteins to the effects of sex hormones is critically examined. It is commonly accepted that androgens induce changes in lipoprotein concentrations that would predispose towards CHD, whereas estrogens are held to have opposite effects. However, much of the evidence for this comes from studies of changes associated with administration of synthetic gonadal steroids or with changes in gonadal function. Studies of differences in lipoprotein metabolism in normal men and women are extremely limited. In males high-density lipoprotein (HDL) cholesterol levels fall at puberty, correlating with the rise in plasma testosterone concentrations. In females, HDL levels do not change at puberty, despite the rise in estrogen concentrations. Evidence for lipoprotein changes during the menopause, when estrogen levels decline, is equivocal. Similarly, the evidence for an increase in CHD incidence at the menopause is inconclusive. National mortality data indicate that the decreasing sex difference in CHD after 50 years of age is due to a declining rate of increase in men rather than to an acceleration in CHD incidence in women. In men

  3. Heritability of Biomarkers of Oxidized Lipoproteins: Twin Pair Study.

    Science.gov (United States)

    Rao, Fangwen; Schork, Andrew J; Maihofer, Adam X; Nievergelt, Caroline M; Marcovina, Santica M; Miller, Elizabeth R; Witztum, Joseph L; O'Connor, Daniel T; Tsimikas, Sotirios

    2015-07-01

    To determine whether biomarkers of oxidized lipoproteins are genetically determined. Lipoprotein(a) (Lp[a]) is a heritable risk factor and carrier of oxidized phospholipids (OxPL). We measured oxidized phospholipids on apolipoprotein B-containing lipoproteins (OxPL-apoB), Lp(a), IgG, and IgM autoantibodies to malondialdehyde-modified low-density lipoprotein, copper oxidized low-density lipoprotein, and apoB-immune complexes in 386 monozygotic and dizygotic twins to estimate trait heritability (h(2)) and determine specific genetic effects among traits. A genome-wide linkage study followed by genetic association was performed. The h(2) (scale: 0-1) for Lp(a) was 0.91±0.01 and for OxPL-apoB 0.87±0.02, which were higher than physiological, inflammatory, or lipid traits. h(2) of IgM malondialdehyde-modified low-density lipoprotein, copper oxidized low-density lipoprotein, and apoB-immune complexes were 0.69±0.04, 0.67±0.05, and 0.80±0.03, respectively, and for IgG malondialdehyde-modified low-density lipoprotein, copper oxidized low-density lipoprotein, and apoB-immune complexes 0.62±0.05, 0.52±0.06, and 0.53±0.06, respectively. There was an inverse correlation between the major apo(a) isoform and OxPL-apoB (R=-0.49; Plipoprotein and copper oxidized low-density lipoprotein, and apoB-immune complexes. Sib-pair genetic linkage of the Lp(a) trait revealed that single nucleotide polymorphism rs10455872 was significantly associated with OxPL-apoB after adjusting for Lp(a). OxPL-apoB and other biomarkers of oxidized lipoproteins are highly heritable cardiovascular risk factors that suggest novel genetic origins of atherothrombosis. © 2015 American Heart Association, Inc.

  4. Recent advances in lipoprotein and atherosclerosis: A nutrigenomic approach

    OpenAIRE

    López, Sergio; Ortega, Almudena; Varela, Lourdes; Bermúdez, Beatriz; Muriana, Francisco JG; Abia, Rocío

    2009-01-01

    Atherosclerosis is a disease in which multiple factors contribute to the degeneration of the vascular wall. Many risk factors have been identified as having influence on the progression of atherosclerosis among them, the type of diet. Multifactorial interaction among lipoproteins, vascular wall cells, and inflammatory mediators has been recognised as the basis of atherogenesis. Dietary intake affects lipoprotein concentration and composition providing risk or protection at several stages of a...

  5. Mechanism of action of gemfibrozil on lipoprotein metabolism.

    OpenAIRE

    Saku, K; Gartside, P S; Hynd, B A; Kashyap, M L

    1985-01-01

    Gemfibrozil is a potent lipid regulating drug whose major effects are to increase plasma high density lipoproteins (HDL) and to decrease plasma triglycerides (TG) in a wide variety of primary and secondary dyslipoproteinemias. Its mechanism of action is not clear. Six patients with primary familial endogenous hypertriglyceridemia with fasting chylomicronemia (type V lipoprotein phenotype) with concurrent subnormal HDL cholesterol levels (HDL deficiency) were treated initially by diet and once...

  6. Lipoprotein(a) as a cardiovascular risk factor: current status

    DEFF Research Database (Denmark)

    Nordestgaard, Børge G; Chapman, M John; Ray, Kausik

    2010-01-01

    The aims of the study were, first, to critically evaluate lipoprotein(a) [Lp(a)] as a cardiovascular risk factor and, second, to advise on screening for elevated plasma Lp(a), on desirable levels, and on therapeutic strategies.......The aims of the study were, first, to critically evaluate lipoprotein(a) [Lp(a)] as a cardiovascular risk factor and, second, to advise on screening for elevated plasma Lp(a), on desirable levels, and on therapeutic strategies....

  7. Hemodynamics alter arterial low-density lipoprotein metabolism

    International Nuclear Information System (INIS)

    Warty, V.S.; Calvo, W.J.; Berceli, S.A.; Pham, S.M.; Durham, S.J.; Tanksale, S.K.; Klein, E.C.; Herman, I.M.; Borovetz, H.S.

    1989-01-01

    We have investigated the role of hemodynamic factors on low-density lipoprotein transport and metabolism in the intact arterial wall. Freshly excised canine carotid blood vessels were exposed to well-defined pulsatile flow in vitro for continuous periods up to 20 hours. We chose to impose the following hemodynamic conditions on our test carotid arteries: normotension, hypertension (at physiologic flow conditions), and hypertension coupled with elevated flow of canine serum perfusate. In several experiments the effect of endothelial denudation was examined in carotid arteries exposed to normotensive pulsatile flow. A trapped ligand method was used for quantitating low-density lipoprotein uptake and metabolism in the arterial wall. The distribution of both intact and degraded low-density lipoprotein fractions was determined from measurements of radiolabelled low-density lipoprotein activity within thin radial sections of perfused arteries. Our results suggest that both hypertensive hemodynamic simulations exacerbate the uptake of low-density lipoprotein within the arterial wall (by a factor of three to nine). The percentage of low-density lipoprotein that undergoes irreversible degradation falls from 41% under normotensive conditions to below 30% when hypertensive conditions are imposed, indicating that degradative processes are not proportionally elevated with the accelerated influx. A similar pattern is observed for deendothelialized vessels

  8. The use of transgenic animals to study lipoprotein metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Rubin, E.M.; Plump, A.S.

    1993-12-01

    The application of transgenic technology to lipoprotein metabolism and atherosclerosis was first reported in 1988. Today, a large percentage of the genes involved in lipoprotein metabolism have been overexpressed in mice, and a substantial number of these same genes have been disrupted by homologous recombination in embryonic stem (ES) cells. The utility of animal models of lipoprotein metabolism and atherosclerosis is far-reaching given the complex nature of these systems. There are at least 17 known genes directly involved in lipoprotein metabolism and likely dozens more may be involved. This massive network of interacting factors has necessitated the development of in vivo systems which can be subject to genetic manipulation. The power of overexpression is obvious: elucidating function in a relatively controlled genetic environment in which the whole system is present and operational. The not-so-obvious problem with transgenics is ``background,`` or for purposes of the current discussion, the mouse`s own lipoprotein system. With the advent of gene knockout, we have been given the ability to overcome ``background.`` By recreating the genetic complement of the mouse we can alter a system in essentially any manner desired. As unique tools, and in combination with one another, the overexpression of foreign genes and the targeted disruption or alteration of endogenous genes has already and will continue to offer a wealth of information on the biology of lipoprotein metabolism and its effect on atherosclerosis susceptibility.

  9. Prediction of lipoprotein signal peptides in Gram-negative bacteria.

    Science.gov (United States)

    Juncker, Agnieszka S; Willenbrock, Hanni; Von Heijne, Gunnar; Brunak, Søren; Nielsen, Henrik; Krogh, Anders

    2003-08-01

    A method to predict lipoprotein signal peptides in Gram-negative Eubacteria, LipoP, has been developed. The hidden Markov model (HMM) was able to distinguish between lipoproteins (SPaseII-cleaved proteins), SPaseI-cleaved proteins, cytoplasmic proteins, and transmembrane proteins. This predictor was able to predict 96.8% of the lipoproteins correctly with only 0.3% false positives in a set of SPaseI-cleaved, cytoplasmic, and transmembrane proteins. The results obtained were significantly better than those of previously developed methods. Even though Gram-positive lipoprotein signal peptides differ from Gram-negatives, the HMM was able to identify 92.9% of the lipoproteins included in a Gram-positive test set. A genome search was carried out for 12 Gram-negative genomes and one Gram-positive genome. The results for Escherichia coli K12 were compared with new experimental data, and the predictions by the HMM agree well with the experimentally verified lipoproteins. A neural network-based predictor was developed for comparison, and it gave very similar results. LipoP is available as a Web server at www.cbs.dtu.dk/services/LipoP/.

  10. Vascular access in lipoprotein apheresis: a retrospective analysis from the UK's largest lipoprotein apheresis centre.

    Science.gov (United States)

    Doherty, Daniel J; Pottle, Alison; Malietzis, George; Hakim, Nadey; Barbir, Mahmoud; Crane, Jeremy S

    2018-01-01

    Lipoprotein apheresis (LA) has proven to be an effective, safe and life-saving therapy. Vascular access is needed to facilitate this treatment but has recognised complications. Despite consistency in treatment indication and duration there are no guidelines in place. The aim of this study is to characterise vascular access practice at the UK's largest LA centre and forward suggestions for future approaches. A retrospective analysis of vascular access strategies was undertaken in all patients who received LA treatment in the low-density lipoprotein (LDL) Apheresis Unit at Harefield Hospital (Middlesex, UK) from November 2000 to March 2016. Fifty-three former and current patients underwent 4260 LA treatments. Peripheral vein cannulation represented 79% of initial vascular access strategies with arteriovenous (AV) fistula use accounting for 15%. Last used method of vascular access was peripheral vein cannulation in 57% versus AV fistula in 32%. Total AV fistula failure rate was 37%. Peripheral vein cannulation remains the most common method to facilitate LA. Practice trends indicate a move towards AV fistula creation; the favoured approach receiving support from the expert body in this area. AV fistula failure rate is high and of great concern, therefore we suggest the implementation of upper limb ultrasound vascular mapping in all patients who meet treatment eligibility criteria. We encourage close ties between apheresis units and specialist surgical centres to facilitate patient counselling and monitoring. Further prospective data regarding fistula failure is needed in this expanding treatment field.

  11. Cholesterol efflux from THP-1 macrophages is impaired by the fatty acid component from lipoprotein hydrolysis by lipoprotein lipase

    International Nuclear Information System (INIS)

    Yang, Yanbo; Thyagarajan, Narmadaa; Coady, Breanne M.; Brown, Robert J.

    2014-01-01

    Highlights: • Lipoprotein hydrolysis products were produced by lipoprotein lipase. • Hydrolysis products lowers expression of macrophage cholesterol transporters. • Hydrolysis products reduces expression of select nuclear receptors. • Fatty acid products lowers cholesterol transporters and select nuclear receptors. • Fatty acid products reduces cholesterol efflux from macrophages. - Abstract: Lipoprotein lipase (LPL) is an extracellular lipase that primarily hydrolyzes triglycerides within circulating lipoproteins. Macrophage LPL contributes to atherogenesis, but the mechanisms behind it are poorly understood. We hypothesized that the products of lipoprotein hydrolysis generated by LPL promote atherogenesis by inhibiting the cholesterol efflux ability by macrophages. To test this hypothesis, we treated human THP-1 macrophages with total lipoproteins that were hydrolyzed by LPL and we found significantly reduced transcript levels for the cholesterol transporters ATP binding cassette transporter A1 (ABCA1), ABCG1, and scavenger receptor BI. These decreases were likely due to significant reductions for the nuclear receptors liver-X-receptor-α, peroxisome proliferator activated receptor (PPAR)-α, and PPAR-γ. We prepared a mixture of free fatty acids (FFA) that represented the ratios of FFA species within lipoprotein hydrolysis products, and we found that the FFA mixture also significantly reduced cholesterol transporters and nuclear receptors. Finally, we tested the efflux of cholesterol from THP-1 macrophages to apolipoprotein A-I, and we found that the treatment of THP-1 macrophages with the FFA mixture significantly attenuated cholesterol efflux. Overall, these data show that the FFA component of lipoprotein hydrolysis products generated by LPL may promote atherogenesis by inhibiting cholesterol efflux, which partially explains the pro-atherogenic role of macrophage LPL

  12. Cholesterol efflux from THP-1 macrophages is impaired by the fatty acid component from lipoprotein hydrolysis by lipoprotein lipase

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yanbo; Thyagarajan, Narmadaa; Coady, Breanne M.; Brown, Robert J., E-mail: rbrown@mun.ca

    2014-09-05

    Highlights: • Lipoprotein hydrolysis products were produced by lipoprotein lipase. • Hydrolysis products lowers expression of macrophage cholesterol transporters. • Hydrolysis products reduces expression of select nuclear receptors. • Fatty acid products lowers cholesterol transporters and select nuclear receptors. • Fatty acid products reduces cholesterol efflux from macrophages. - Abstract: Lipoprotein lipase (LPL) is an extracellular lipase that primarily hydrolyzes triglycerides within circulating lipoproteins. Macrophage LPL contributes to atherogenesis, but the mechanisms behind it are poorly understood. We hypothesized that the products of lipoprotein hydrolysis generated by LPL promote atherogenesis by inhibiting the cholesterol efflux ability by macrophages. To test this hypothesis, we treated human THP-1 macrophages with total lipoproteins that were hydrolyzed by LPL and we found significantly reduced transcript levels for the cholesterol transporters ATP binding cassette transporter A1 (ABCA1), ABCG1, and scavenger receptor BI. These decreases were likely due to significant reductions for the nuclear receptors liver-X-receptor-α, peroxisome proliferator activated receptor (PPAR)-α, and PPAR-γ. We prepared a mixture of free fatty acids (FFA) that represented the ratios of FFA species within lipoprotein hydrolysis products, and we found that the FFA mixture also significantly reduced cholesterol transporters and nuclear receptors. Finally, we tested the efflux of cholesterol from THP-1 macrophages to apolipoprotein A-I, and we found that the treatment of THP-1 macrophages with the FFA mixture significantly attenuated cholesterol efflux. Overall, these data show that the FFA component of lipoprotein hydrolysis products generated by LPL may promote atherogenesis by inhibiting cholesterol efflux, which partially explains the pro-atherogenic role of macrophage LPL.

  13. Cholesterol efflux from THP-1 macrophages is impaired by the fatty acid component from lipoprotein hydrolysis by lipoprotein lipase.

    Science.gov (United States)

    Yang, Yanbo; Thyagarajan, Narmadaa; Coady, Breanne M; Brown, Robert J

    2014-09-05

    Lipoprotein lipase (LPL) is an extracellular lipase that primarily hydrolyzes triglycerides within circulating lipoproteins. Macrophage LPL contributes to atherogenesis, but the mechanisms behind it are poorly understood. We hypothesized that the products of lipoprotein hydrolysis generated by LPL promote atherogenesis by inhibiting the cholesterol efflux ability by macrophages. To test this hypothesis, we treated human THP-1 macrophages with total lipoproteins that were hydrolyzed by LPL and we found significantly reduced transcript levels for the cholesterol transporters ATP binding cassette transporter A1 (ABCA1), ABCG1, and scavenger receptor BI. These decreases were likely due to significant reductions for the nuclear receptors liver-X-receptor-α, peroxisome proliferator activated receptor (PPAR)-α, and PPAR-γ. We prepared a mixture of free fatty acids (FFA) that represented the ratios of FFA species within lipoprotein hydrolysis products, and we found that the FFA mixture also significantly reduced cholesterol transporters and nuclear receptors. Finally, we tested the efflux of cholesterol from THP-1 macrophages to apolipoprotein A-I, and we found that the treatment of THP-1 macrophages with the FFA mixture significantly attenuated cholesterol efflux. Overall, these data show that the FFA component of lipoprotein hydrolysis products generated by LPL may promote atherogenesis by inhibiting cholesterol efflux, which partially explains the pro-atherogenic role of macrophage LPL. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Novel estrogen receptor-related Transcripts in Marisa cornuarietis; a freshwater snail with reported sensitivity to estrogenic chemicals.

    Science.gov (United States)

    Bannister, Richard; Beresford, Nicola; May, Denise; Routledge, Edwin J; Jobling, Susan; Rand-Weaver, Mariann

    2007-04-01

    We have isolated novel molluskan steroid receptor transcripts orthologous to vertebrate estrogen receptors (ERs) and estrogen receptor-related receptors (ERRs) from the freshwater snail Marisa cornuarietis. Radiolabeled ligand binding analyses showed that neither recombinant receptor protein specifically bound 17beta-estradiol over the range applied (0.3-9.6 nM). These novel receptor transcripts have thus been designated mcER-like and mcERR respectively. Quantitative PCR revealed mcER-like to be expressed ubiquitously throughout a range of male and female structures studied, including neural and reproductive tissues. Highest absolute levels were seen in the male penis-sheath complex. The mcERR mRNA was also expressed ubiquitously throughout all male and female tissues analyzed here, with very low absolute transcript numbers in female accessory sex structures compared to other tissues.

  15. Preparation and Characterization of Stable α-Synuclein Lipoprotein Particles.

    Science.gov (United States)

    Eichmann, Cédric; Campioni, Silvia; Kowal, Julia; Maslennikov, Innokentiy; Gerez, Juan; Liu, Xiaoxia; Verasdonck, Joeri; Nespovitaya, Nadezhda; Choe, Senyon; Meier, Beat H; Picotti, Paola; Rizo, Josep; Stahlberg, Henning; Riek, Roland

    2016-04-15

    Multiple neurodegenerative diseases are caused by the aggregation of the human α-Synuclein (α-Syn) protein. α-Syn possesses high structural plasticity and the capability of interacting with membranes. Both features are not only essential for its physiological function but also play a role in the aggregation process. Recently it has been proposed that α-Syn is able to form lipid-protein particles reminiscent of high-density lipoproteins. Here, we present a method to obtain a stable and homogeneous population of nanometer-sized particles composed of α-Syn and anionic phospholipids. These particles are called α-Syn lipoprotein (nano)particles to indicate their relationship to high-density lipoproteins formed by human apolipoproteins in vivo and of in vitro self-assembling phospholipid bilayer nanodiscs. Structural investigations of the α-Syn lipoprotein particles by circular dichroism (CD) and magic angle solid-state nuclear magnetic resonance (MAS SS-NMR) spectroscopy establish that α-Syn adopts a helical secondary structure within these particles. Based on cryo-electron microscopy (cryo-EM) and dynamic light scattering (DLS) α-Syn lipoprotein particles have a defined size with a diameter of ∼23 nm. Chemical cross-linking in combination with solution-state NMR and multiangle static light scattering (MALS) of α-Syn particles reveal a high-order protein-lipid entity composed of ∼8-10 α-Syn molecules. The close resemblance in size between cross-linked in vitro-derived α-Syn lipoprotein particles and a cross-linked species of endogenous α-Syn from SH-SY5Y human neuroblastoma cells indicates a potential functional relevance of α-Syn lipoprotein nanoparticles. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  16. Characterization of lipoproteins in human and canine cerebrospinal fluid (CSF)

    International Nuclear Information System (INIS)

    Pitas, R.E.; Weisgraber, K.H.; Boyles, J.K.; Lee, S.; Mahley, R.W.

    1986-01-01

    Previously the authors demonstrated that rat brain astrocytes in vitro synthesize and secrete apo-E and possess apo-B,E(LDL) receptors. The apo-E secreted by astrocytes and apo-E in rat brain extracts differed from serum apo-E in two respects. Brain apo-E had a higher apparent molecular weight and a higher percentage of more acidic isoforms. To characterize further the apo-E within the central nervous system, apo-E in human and canine CSF was investigated. Compared to plasma apo-E, CSF apo-E had a higher apparent M/sub r/ and a higher percentage of acidic isoforms which were sialylated, as shown by neuraminidase digestion. The apo-E in human CSF was approx.5-10% of the plasma level. In CSF 60-80% of the apo-E was in lipoproteins with d = 1.09-1.15. The remainder of the apo-E was in the d > 1.21 fraction. Human CSF lipoproteins were primarily spherical (110-190 A) while canine CSF lipoproteins were a mixture of discs (205 x 65 A) while canine CSF lipoproteins were a mixture of discs (205 x 65 A) and spheres (100-150 A). The CSF also contained apo-AI in the d = 1.09-1.15 g/ml fraction. Human CSF lipoproteins containing both apo-E and apo-AI were isolated on an anti-apo-E affinity column, suggesting that apo-E and AI occurred in the same particles. The CSF apo-E-containing lipoproteins competed for binding of 125 I-LDL to the apo-B,E(LDL) receptor. There was no detectable apo-B in CSF. These data suggest that CSF lipoproteins might transport lipid and regulate lipid homeostasis within the brain

  17. Aminoacylation of the N-terminal cysteine is essential for Lol-dependent release of lipoproteins from membranes but does not depend on lipoprotein sorting signals.

    Science.gov (United States)

    Fukuda, Ayumu; Matsuyama, Shin-Ichi; Hara, Takashi; Nakayama, Jiro; Nagasawa, Hiromichi; Tokuda, Hajime

    2002-11-08

    Lipoproteins are present in a wide variety of bacteria and are anchored to membranes through lipids attached to the N-terminal cysteine. The Lol system of Escherichia coli mediates the membrane-specific localization of lipoproteins. Aspartate at position 2 functions as a Lol avoidance signal and causes the retention of lipoproteins in the inner membrane, whereas lipoproteins having residues other than aspartate at position 2 are released from the inner membrane and localized to the outer membrane by the Lol system. Phospholipid:apolipoprotein transacylase, Lnt, catalyzes the last step of lipoprotein modification, converting apolipoprotein into mature lipoprotein. To reveal the importance of this aminoacylation for the Lol-dependent membrane localization, apolipoproteins were prepared by inhibiting lipoprotein maturation. Lnt was also purified and used to convert apolipoprotein into mature lipoprotein in vitro. The release of these lipoproteins was examined in proteoliposomes. We show here that the aminoacylation is essential for the Lol-dependent release of lipoproteins from membranes. Furthermore, lipoproteins with aspartate at position 2 were found to be aminoacylated both in vivo and in vitro, indicating that the lipoprotein-sorting signal does not affect lipid modification.

  18. Activated platelets contribute to oxidized low-density lipoproteins and dysfunctional high-density lipoproteins through a phospholipase A2-dependent mechanism

    NARCIS (Netherlands)

    Blache, Denis; Gautier, Thomas; Tietge, Uwe J. F.; Lagrost, Laurent

    Plasma activity of secretory phospholipase A2 (sPLA2) increases in patients with cardiovascular disease. The present study investigated whether platelet-released sPLA2 induces low-density lipoprotein (LDL) and high-density lipoprotein (HDL) modifications that translate into changes in lipoprotein

  19. Achieving secondary prevention low-density lipoprotein particle concentration goals using lipoprotein cholesterol-based data.

    Directory of Open Access Journals (Sweden)

    Simon C Mathews

    Full Text Available BACKGROUND: Epidemiologic studies suggest that LDL particle concentration (LDL-P may remain elevated at guideline recommended LDL cholesterol goals, representing a source of residual risk. We examined the following seven separate lipid parameters in achieving the LDL-P goal of <1000 nmol/L goal for very high risk secondary prevention: total cholesterol to HDL cholesterol ratio, TC/HDL, <3; a composite of ATP-III very high risk targets, LDL-C<70 mg/dL, non-HDL-C<100 mg/dL and TG<150 mg/dL; a composite of standard secondary risk targets, LDL-C<100, non-HDL-C<130, TG<150; LDL phenotype; HDL-C ≥ 40; TG<150; and TG/HDL-C<3. METHODS: We measured ApoB, ApoAI, ultracentrifugation lipoprotein cholesterol and NMR lipoprotein particle concentration in 148 unselected primary and secondary prevention patients. RESULTS: TC/HDL-C<3 effectively discriminated subjects by LDL-P goal (F = 84.1, p<10(-6. The ATP-III very high risk composite target (LDL-C<70, nonHDL-C<100, TG<150 was also effective (F = 42.8, p<10(-5. However, the standard secondary prevention composite (LDL-C<100, non-HDL-C<130, TG<150 was also effective but yielded higher LDL-P than the very high risk composite (F = 42.0, p<10(-5 with upper 95% confidence interval of LDL-P less than 1000 nmol/L. TG<150 and TG/HDL-C<3 cutpoints both significantly discriminated subjects but the LDL-P upper 95% confidence intervals fell above goal of 1000 nmol/L (F = 15.8, p = 0.0001 and F = 9.7, p = 0.002 respectively. LDL density phenotype neared significance (F = 2.85, p = 0.094 and the HDL-C cutpoint of 40 mg/dL did not discriminate (F = 0.53, p = 0.47 alone or add discriminatory power to ATP-III targets. CONCLUSIONS: A simple composite of ATP-III very high risk lipoprotein cholesterol based treatment targets or TC/HDL-C ratio <3 most effectively identified subjects meeting the secondary prevention target level of LDL-P<1000 nmol/L, providing a potential alternative to advanced lipid testing in many clinical

  20. Binding of alpha2ML1 to the low density lipoprotein receptor-related protein 1 (LRP1 reveals a new role for LRP1 in the human epidermis.

    Directory of Open Access Journals (Sweden)

    Marie-Florence Galliano

    Full Text Available BACKGROUND: The multifunctional receptor LRP1 has been shown to bind and internalize a large number of protein ligands with biological importance such as the pan-protease inhibitor alpha2-macroglobulin (alpha2M. We recently identified Alpha2ML1, a new member of the alpha2M gene family, expressed in epidermis. alpha2ML1 might contribute to the regulation of desquamation through its inhibitory activity towards proteases of the chymotrypsin family, notably KLK7. The expression of LRP1 in epidermis as well as its ability to internalize alpha2ML1 was investigated. METHODS AND PRINCIPAL FINDINGS: In human epidermis, LRP1 is mainly expressed within the granular layer of the epidermis, which gathers the most differentiated keratinocytes, as shown by immunohistochemistry and immunofluorescence using two different antibodies. By using various experimental approaches, we show that the receptor binding domain of alpha2ML1 (RBDl is specifically internalized into the macrophage-like cell line RAW and colocalizes with LRP1 upon internalization. Coimmunoprecipitation assays demonstrate that RBDl binds LRP1 at the cell surface. Addition of RAP, a universal inhibitor of ligand binding to LRP1, prevents RBDl binding at the cell surface as well as internalization into RAW cells. Silencing Lrp1 expression with specific siRNA strongly reduces RBDl internalization. CONCLUSIONS AND SIGNIFICANCE: Keratinocytes of the upper differentiated layers of epidermis express LRP1 as well as alpha2ML1. Our study also reveals that alpha2ML1 is a new ligand for LRP1. Our findings are consistent with endocytosis by LRP1 of complexes formed between alpha2ML1 and proteases. LRP1 may thus control desquamation by regulating the biodisponibility of extracellular proteases.

  1. Osteoclasts from patients with autosomal dominant osteopetrosis type I caused by a T253I mutation in low-density lipoprotein receptor-related protein 5 are normal in vitro, but have decreased resorption capacity in vivo

    DEFF Research Database (Denmark)

    Henriksen, Kim; Gram, Jeppe; Høegh-Andersen, Pernille

    2005-01-01

    of osteoclast markers, morphology, and localization of proteins involved in bone resorption, such as ClC-7 and cathepsin K. The ability to resorb bone was also normal. In vivo, we compared the bone resorption and bone formation response to T3 in ADOI patients and age- and sex-matched controls. We found...

  2. Effect of I125 on oxidation behavior of lipoprotein subpopulations

    International Nuclear Information System (INIS)

    Majtenyi, S.

    2002-07-01

    Lipoproteins play a central role in lipid metabolism. They serve as a transport vehicle for cholesterol and triglycerides keeping them in plasma in solution. Lipoproteins are characterized by the content of specific apoproteins and differences in the hydrated density ranges. Moreover, they are distinguished by electrophoretic mobility and other characteristics as high and low-density lipoproteins, respectively lipoprotein (a). More specifically, HDL is classified into HDL 2 and HDL 3 . In atherogenesis, lipoproteins are considered to play a key-role. Oxidatively modified LDL is selectively taken up via scavenger receptors of the macrophage-monocyte system. These cells are transformed into foam cells promoting atherogenesis in vessels in the subendothelial space. Oxidized HDL essentially appears to loose its protective effects on LDL and its beneficial function in reverse cholesterol transport. Thus, it turns proatherogenic. The effects various species of free radicals exert on lipoproteins are the reason for this oxidative modification. Thyroid function also influences lipoproteins in a complex manner. Based on their hydrated density ranges, lipoprotein subpopulations were fractionated and isolated via isopycnic density gradient ultracentrifugation. After investigation of the general oxidation behavior, initiated by addition of CuSO 4 to the isolated samples of HDL 3 , HDL 2 , LDL and Lp(a), the influence of different activities of radioiodine-125 on the kinetics of the formation of conjugated dienes was assessed. This was achieved by coincubation of plasma with I 125 . The spectrophotometrical measurement of the concentration of conjugated dienes in the course of CuSO 4 -induced lipid peroxidation leads to measurable changes in absorption at 234 nm. These changes in absorption over time result in a characteristically shaped curve graphically plotted. The shape of these curves mirrors different indicators of lipid peroxidation. Therefrom lag time, maximal

  3. Interfacial Tension and Surface Pressure of High Density Lipoprotein, Low Density Lipoprotein, and Related Lipid Droplets

    DEFF Research Database (Denmark)

    Ollila, O. H. S.; Lamberg, A.; Lehtivaara, M.

    2012-01-01

    ) are essentially lipid droplets surrounded by specific proteins, their main function being to transport cholesterol. Interfacial tension and surface pressure of these particles are of great interest because they are related to the shape and the stability of the droplets and to protein adsorption at the interface....... Here we use coarse-grained molecular-dynamics simulations to consider a number of related issues by calculating the interfacial tension in protein-free lipid droplets, and in HDL and LDL particles mimicking physiological conditions. First, our results suggest that the curvature dependence......Lipid droplets play a central role in energy storage and metabolism on a cellular scale. Their core is comprised of hydrophobic lipids covered by a surface region consisting of amphiphilic lipids and proteins. For example, high and low density lipoproteins (HDL and LDL, respectively...

  4. Low density lipoproteins mediated nanoplatforms for cancer targeting

    International Nuclear Information System (INIS)

    Jain, Anupriya; Jain, Keerti; Kesharwani, Prashant; Jain, Narendra K.

    2013-01-01

    Chemotherapy is a foremost remedial approach for the treatment of localized and metastasized tumors. In order to explore new treatment modalities for cancer, it is important to identify qualitative or quantitative differences in metabolic processes between normal and malignant cells. One such difference may be that of increased receptor-mediated cellular uptake of low density lipoproteins (LDLs) by cancer cells. Lipoproteins in general and specifically LDL are ideal candidates for loading and delivering cancer therapeutic and diagnostic agents due to their biocompatibility. By mimicking the endogenous shape and structure of lipoproteins, the reconstituted lipoproteins can remain in circulation for an extended period of time, while largely evading the reticuloendothelial cells in the body’s defenses. In this account, we review the field of low density inspired nanoparticles in relation to the delivery of cancer imaging and therapeutic agents. LDL has instinctive cancer targeting potential and has been used to incorporate various lipophillic molecules to transport them to tumors. Nature’s method of rerouting LDL provides a strategy to extend the cancer targeting potential of lipoproteins far off its constricted purview. In this review, we have discussed the various aspects of LDL including its role in cancer imaging and chemotherapy in retrospect and prospect and current efforts aimed to further improve the delivery efficacy of LDL–drug complexes with reduced chances of drug resistance leading to optimal drug delivery. This review provides a strong support for the concept of using LDL as a drug carrier

  5. Serum lipid and lipoprotein concentrations following exposure to ozone

    Energy Technology Data Exchange (ETDEWEB)

    Vaughan, W J; Adamson, G L; Lindgren, F T; Schooley, J.C.

    1984-07-01

    The effects of exposure to ozone (O/sub 3/) on concentrations of serum lipids and lipoproteins were investigated. Male and female guinea pigs were exposed to O/sub 3/ at 1 ppm for two weeks. Serum concentrations of cholesterol, triglycerides, low density (LDL) and very low density (VLDL) lipoproteins were elevated after O/sub 3/ exposure, particularly in males. During O/sub 3/ exposure the food intake per day decreased (for a constant body weight), suggesting that metabolic rate and possibly basal metabolic rate was lower. Lung wet weights increased during O/sub 3/ exposure by 87% for males and 45% for females. When individual lung weight/body weight ratios were correlated with cholesterol and LDL values from the same animal, a high correlation is found for males (r . 0.81, P less than 0.05), suggesting that there may be a relationship between lipoprotein elevations and lung damage for males. Because elevated concentrations of lipids and lipoproteins in humans increase the risk of coronary heart disease (CHD), the lipoprotein results suggest that an epidemiological study of the incidence of CHD with metropolitan O/sub 3/ levels may be warranted.

  6. Lipoproteins tethered dendrimeric nanoconstructs for effective targeting to cancer cells

    Science.gov (United States)

    Jain, Anupriya; Jain, Keerti; Mehra, Neelesh Kumar; Jain, N. K.

    2013-10-01

    In the present investigation, poly (propylene imine) dendrimers up to fifth generation (PPI G5.0) were synthesized using ethylene diamine and acrylonitrile. Lipoproteins (high-density lipoprotein; HDL and low-density lipoprotein; LDL) were isolated from human plasma by discontinuous density gradient ultracentrifugation, characterized and tethered to G5.0 PPI dendrimers to construct LDL- and HDL-conjugated dendrimeric nanoconstructs for tumor-specific delivery of docetaxel. Developed formulations showed sustained release characteristics in in vitro drug release and in vivo pharmacokinetic studies. The cancer targeting potential of lipoprotein coupled dendrimers was investigated by ex vivo cytotoxicity and cell uptake studies using human hepatocellular carcinoma cell lines (HepG2 cells) and biodistribution studies in albino rats of Sprague-Dawley strain. Lipoprotein anchored dendrimeric nanoconstructs showed significant uptake by cancer cells as well as higher biodistribution of docetaxel to liver and spleen. It is concluded that these precisely synthesized engineered dendrimeric nanoconstructs could serve as promising drug carrier for fighting with the fatal disease, i.e., cancer, attributed to their defined targeting and therapeutic potential.

  7. Low density lipoproteins mediated nanoplatforms for cancer targeting

    Energy Technology Data Exchange (ETDEWEB)

    Jain, Anupriya; Jain, Keerti; Kesharwani, Prashant, E-mail: prashant_pharmacy04@rediffmail.com; Jain, Narendra K., E-mail: jnarendr@yahoo.co.in [Dr. H. S. Gour University, Pharmaceutics Research Laboratory, Department of Pharmaceutical Sciences (India)

    2013-09-15

    Chemotherapy is a foremost remedial approach for the treatment of localized and metastasized tumors. In order to explore new treatment modalities for cancer, it is important to identify qualitative or quantitative differences in metabolic processes between normal and malignant cells. One such difference may be that of increased receptor-mediated cellular uptake of low density lipoproteins (LDLs) by cancer cells. Lipoproteins in general and specifically LDL are ideal candidates for loading and delivering cancer therapeutic and diagnostic agents due to their biocompatibility. By mimicking the endogenous shape and structure of lipoproteins, the reconstituted lipoproteins can remain in circulation for an extended period of time, while largely evading the reticuloendothelial cells in the body's defenses. In this account, we review the field of low density inspired nanoparticles in relation to the delivery of cancer imaging and therapeutic agents. LDL has instinctive cancer targeting potential and has been used to incorporate various lipophillic molecules to transport them to tumors. Nature's method of rerouting LDL provides a strategy to extend the cancer targeting potential of lipoproteins far off its constricted purview. In this review, we have discussed the various aspects of LDL including its role in cancer imaging and chemotherapy in retrospect and prospect and current efforts aimed to further improve the delivery efficacy of LDL-drug complexes with reduced chances of drug resistance leading to optimal drug delivery. This review provides a strong support for the concept of using LDL as a drug carrier.

  8. Low density lipoproteins mediated nanoplatforms for cancer targeting

    Science.gov (United States)

    Jain, Anupriya; Jain, Keerti; Kesharwani, Prashant; Jain, Narendra K.

    2013-09-01

    Chemotherapy is a foremost remedial approach for the treatment of localized and metastasized tumors. In order to explore new treatment modalities for cancer, it is important to identify qualitative or quantitative differences in metabolic processes between normal and malignant cells. One such difference may be that of increased receptor-mediated cellular uptake of low density lipoproteins (LDLs) by cancer cells. Lipoproteins in general and specifically LDL are ideal candidates for loading and delivering cancer therapeutic and diagnostic agents due to their biocompatibility. By mimicking the endogenous shape and structure of lipoproteins, the reconstituted lipoproteins can remain in circulation for an extended period of time, while largely evading the reticuloendothelial cells in the body's defenses. In this account, we review the field of low density inspired nanoparticles in relation to the delivery of cancer imaging and therapeutic agents. LDL has instinctive cancer targeting potential and has been used to incorporate various lipophillic molecules to transport them to tumors. Nature's method of rerouting LDL provides a strategy to extend the cancer targeting potential of lipoproteins far off its constricted purview. In this review, we have discussed the various aspects of LDL including its role in cancer imaging and chemotherapy in retrospect and prospect and current efforts aimed to further improve the delivery efficacy of LDL-drug complexes with reduced chances of drug resistance leading to optimal drug delivery. This review provides a strong support for the concept of using LDL as a drug carrier.

  9. Recombinant Lipoproteins as Novel Vaccines with Intrinsic Adjuvant.

    Science.gov (United States)

    Chong, Pele; Huang, Jui-Hsin; Leng, Chih-Hsiang; Liu, Shih-Jen; Chen, Hsin-Wei

    2015-01-01

    A core platform technology for high production of recombinant lipoproteins with built-in immunostimulator for novel subunit vaccine development has been established. This platform technology has the following advantages: (1) easily convert antigen into lipidated recombinant protein using a fusion sequence containing lipobox and express high level (50-150mg/L) in Escherichia coli; (2) a robust high-yield up- and downstream bioprocess for lipoprotein production is successfully developed to devoid endotoxin contamination; (3) the lipid moiety of recombinant lipoproteins, which is identical to that of bacterial lipoproteins is recognized as danger signals by the immune system (Toll-like receptor 2 agonist), so both innate and adaptive immune responses can be induced by lipoproteins; and (4) successfully demonstrate the feasibility and safety of this core platform technology in meningococcal group B subunit vaccine, dengue subunit vaccine, novel subunit vaccine against Clostridium difficile-associated diseases, and HPV-based immunotherapeutic vaccines in animal model studies. © 2015 Elsevier Inc. All rights reserved.

  10. Learning from biology: synthetic lipoproteins for drug delivery.

    Science.gov (United States)

    Huang, Huang; Cruz, William; Chen, Juan; Zheng, Gang

    2015-01-01

    Synthetic lipoproteins represent a relevant tool for targeted delivery of biological/chemical agents (chemotherapeutics, siRNAs, photosensitizers, and imaging contrast agents) into various cell types. These nanoparticles offer a number of advantages for drugs delivery over their native counterparts while retaining their natural characteristics and biological functions. Their ultra-small size (lipoprotein receptors, i.e., low-density lipoprotein receptor (LDLR) and Scavenger receptor class B member 1 (SRB1) that are found in a number of pathological conditions (e.g., cancer, atherosclerosis), make them superior delivery strategies when compared with other nanoparticle systems. We review the various approaches that have been developed for the generation of synthetic lipoproteins and their respective applications in vitro and in vivo. More specifically, we summarize the approaches employed to address the limitation on use of reconstituted lipoproteins by means of natural or recombinant apolipoproteins, as well as apolipoprotein mimetic molecules. Finally, we provide an overview of the advantages and disadvantages of these approaches and discuss future perspectives for clinical translation of these nanoparticles. © 2014 Wiley Periodicals, Inc.

  11. Regulation of hepatic lipase activity by sphingomyelin in plasma lipoproteins.

    Science.gov (United States)

    Yang, Peng; Subbaiah, Papasani V

    2015-10-01

    Hepatic lipase (HL) is an important enzyme in the clearance of triacylglycerol (TAG) from the circulation, and has been proposed to have pro-atherogenic as well as anti-atherogenic properties. It hydrolyzes both phospholipids and TAG of lipoproteins, and its activity is negatively correlated with HDL levels. Although it is known that HL acts preferentially on HDL lipids, the basis for this specificity is not known, since it does not require any specific apoprotein for activity. In this study, we tested the hypothesis that sphingomyelin (SM), whose concentration is much higher in VLDL and LDL compared to HDL, is an inhibitor of HL, and that this could explain the lipoprotein specificity of the enzyme. The results presented show that the depletion of SM from normal lipoproteins activated the HL roughly in proportion to their SM content. SM depletion stimulated the hydrolysis of both phosphatidylcholine (PC) and TAG, although the PC hydrolysis was stimulated more. In the native lipoproteins, HL showed specificity for PC species containing polyunsaturated fatty acids at sn-2 position, and produced more unsaturated lyso PC species. The enzyme also showed preferential hydrolysis of certain TAG species over others. SM depletion affected the specificity of the enzyme towards PC and TAG species modestly. These results show that SM is a physiological inhibitor of HL activity in lipoproteins and that the specificity of the enzyme towards HDL is at least partly due to its low SM content. Published by Elsevier B.V.

  12. Lipoproteins tethered dendrimeric nanoconstructs for effective targeting to cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Jain, Anupriya; Jain, Keerti, E-mail: keertijain02@gmail.com; Mehra, Neelesh Kumar, E-mail: neelesh81mph@gmail.com; Jain, N. K., E-mail: dr.jnarendr@gmail.com [Dr. H. S. Gour University, Pharmaceutics Research Laboratory, Department of Pharmaceutical Sciences (India)

    2013-10-15

    In the present investigation, poly (propylene imine) dendrimers up to fifth generation (PPI G5.0) were synthesized using ethylene diamine and acrylonitrile. Lipoproteins (high-density lipoprotein; HDL and low-density lipoprotein; LDL) were isolated from human plasma by discontinuous density gradient ultracentrifugation, characterized and tethered to G5.0 PPI dendrimers to construct LDL- and HDL-conjugated dendrimeric nanoconstructs for tumor-specific delivery of docetaxel. Developed formulations showed sustained release characteristics in in vitro drug release and in vivo pharmacokinetic studies. The cancer targeting potential of lipoprotein coupled dendrimers was investigated by ex vivo cytotoxicity and cell uptake studies using human hepatocellular carcinoma cell lines (HepG2 cells) and biodistribution studies in albino rats of Sprague-Dawley strain. Lipoprotein anchored dendrimeric nanoconstructs showed significant uptake by cancer cells as well as higher biodistribution of docetaxel to liver and spleen. It is concluded that these precisely synthesized engineered dendrimeric nanoconstructs could serve as promising drug carrier for fighting with the fatal disease, i.e., cancer, attributed to their defined targeting and therapeutic potential.

  13. Experimental hypothyroidism modulates the expression of the low density lipoprotein receptor by the liver

    International Nuclear Information System (INIS)

    Scarabottolo, Lia; Trezzi, Ermanno; Roma, Paola; Catapano, A.L.

    1986-01-01

    The effect of exprimental hypothyroidism of the catabolism of plasma lipoproteins and on the expression of low density lipoprotein receptors by the liver was investigated in rats made hypothyroid by surgery. The animals developed mild hypercholesterolemia, mainly due to an increase of plasma low density lipoprotein, while other lipoprotein classes were only marginally affected. Kinetic studies using ( 125 I)LDL indicated that a decreased fractional catabolic rate of the lipoprotein was responsible for this finding in agreement with the in vitro observation of a reduced binding of lipoproteins to liver membranes from hyperthyroid rats and with the demonstrations, by ligand blotting analysis, of a decreasd expression of lipoprotein receptors in liver membranes. These data suggest that hypothyroidism affects lipoprotein distribution also by decreasing the catabolism of low density lipoproteins by the liver (author)

  14. Tissue-type plasminogen activator-binding RNA aptamers inhibiting low-density lipoprotein receptor family-mediated internalisation.

    Science.gov (United States)

    Bjerregaard, Nils; Bøtkjær, Kenneth A; Helsen, Nicky; Andreasen, Peter A; Dupont, Daniel M

    2015-07-01

    Recombinant tissue-type plasminogen activator (tPA, trade name Alteplase), currently the only drug approved by the US Food and Drug Administration and the European Medicines Agency for the treatment of cerebral ischaemic stroke, has been implicated in a number of adverse effects reportedly mediated by interactions with the low-density lipoprotein (LDL) family receptors, including neuronal cell death and an increased risk of cerebral haemorrhage. The tissue-type plasminogen activator is the principal initiator of thrombolysis in human physiology, an effect that is mediated directly via localised activation of the plasmin zymogen plasminogen at the surface of fibrin clots in the vascular lumen. Here, we sought to identify a ligand to tPA capable of inhibiting the relevant LDL family receptors without interfering with the fibrinolytic activity of tPA. Systematic evolution of ligands by exponential enrichment (SELEX) was employed to isolate tPA-binding RNA aptamers, which were characterised in biochemical assays of tPA association to low density lipoprotein receptor-related protein-1 (LRP-1, an LDL receptor family member); tPA-mediated in vitro and ex vivo clot lysis; and tPA-mediated plasminogen activation in the absence and presence of a stimulating soluble fibrin fragment. Two aptamers, K18 and K32, had minimal effects on clot lysis, but were able to efficiently inhibit tPA-LRP-1 association and LDL receptor family-mediated endocytosis in human vascular endothelial cells and astrocytes. These observations suggest that coadministration alongside tPA may be a viable strategy to improve the safety of thrombolytic treatment of cerebral ischaemic stroke by restricting tPA activity to the vascular lumen.

  15. A high-density lipoprotein-mediated drug delivery system.

    Science.gov (United States)

    Mo, Zhong-Cheng; Ren, Kun; Liu, Xing; Tang, Zhen-Li; Yi, Guang-Hui

    2016-11-15

    High-density lipoprotein (HDL) is a comparatively dense and small lipoprotein that can carry lipids as a multifunctional aggregate in plasma. Several studies have shown that increasing the levels or improving the functionality of HDL is a promising target for treating a wide variety of diseases. Among lipoproteins, HDL particles possess unique physicochemical properties, including naturally synthesized physiological components, amphipathic apolipoproteins, lipid-loading and hydrophobic agent-incorporating characteristics, specific protein-protein interactions, heterogeneity, nanoparticles, and smaller size. Recently, the feasibility and superiority of using HDL particles as drug delivery vehicles have been of great interest. In this review, we summarize the structure, constituents, biogenesis, remodeling, and reconstitution of HDL drug delivery systems, focusing on their delivery capability, characteristics, applications, manufacturing, and drug-loading and drug-targeting characteristics. Finally, the future prospects are presented regarding the clinical application and challenges of using HDL as a pharmacodelivery carrier. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Transvascular lipoprotein transport in patients with chronic renal disease

    DEFF Research Database (Denmark)

    Jensen, Trine Krogsgaard; Nordestgaard, Børge Grønne; Feldt-Rasmussen, Bo

    2004-01-01

    BACKGROUND: While increased plasma cholesterol is a well-established cardiovascular risk factor in the general population, this is not so among patients with chronic renal disease. We hypothesized that the transvascular lipoprotein transport, in addition to the lipoprotein concentration in plasma......, determines the degree of atherosclerosis among patients with chronic renal disease. METHODS: We used an in vivo method for measurement of transvascular transport of low-density lipoprotein (LDL) in 21 patients with chronic renal disease and in 42 healthy control patients. Autologous 131-iodinated LDL...... was reinjected intravenously, and the 1-hour fractional escape rate was taken as index of transvascular transport. RESULTS: Transvascular LDL transport tended to be lower in patients with chronic renal disease than in healthy control patients [3.3 (95% CI 2.4-4.2) vs. 4.2 (3.7-4.2)%/hour; NS]. However...

  17. Immunosuppressive activity of human cord-blood lipoproteins

    International Nuclear Information System (INIS)

    Forte, T.M.; Davis, P.A.; Curtiss, L.K.

    1985-01-01

    It is now known that the role of plasma lipoproteins is multifunctional. More recently it has been shown that lipoproteins may regulate immune responses as well. Low-density lipoproteins carrying apolipoprotein B (apoB) are known to suppress phytohemagglutinin (PHA) activated lymphocytes by inhibiting DNA synthesis. More recently, an immunoregulatory role has been described for another apolipoprotein, apoE, which is found in low quantities in normal plasma. In these studies with human umbilical-cord blood the authors were intrigued by two factors: the low level of LDL and hence apoB, and the elevated quantity of apoE. This study examines the hypothesis that apoE may regulate lymphocyte function in the human fetus

  18. Lipoprotein-associated phospholipase A2 distribution among lipoproteins differs in type 1 diabetes.

    Science.gov (United States)

    Jarvie, Jennifer L; Wang, Hong; Kinney, Gregory L; Snell-Bergeon, Janet; Hokanson, John E; Eckel, Robert H

    2016-01-01

    LpPLA2 mass and activity have been variably related to cardiovascular disease risk, and the distribution of LpPLA2 in patients with type 1 diabetes (T1D), wherein cardiovascular disease risk is high despite normal or higher levels of high-density lipoprotein (HDL) cholesterol, is unknown. To determine whether there are differences in the distribution of LpPLA2 mass and activity across lipoproteins and their association with coronary artery calcium (CAC) in patients with T1D. Men with T1D (n = 19) not on statins, with and without CAC progression, and men without diabetes matched for HDL cholesterol (n = 25) had lipoproteins separated by fast protein liquid chromatography. Both LpPLA2 mass and activity were found within low-density lipoprotein (LDL) and HDL pools with more LpPLA2 mass being associated with HDL (54% vs 44%; P-value lipoprotein subfractions was observed between all groups, and there was no relationship between LpPLA2 activity or mass and its distribution and CAC score progression in healthy or T1D men. LpPLA2 is found in both LDL and HDL and is distributed differently in men with T1D without any relationship to CAC score progression. Copyright © 2016 National Lipid Association. Published by Elsevier Inc. All rights reserved.

  19. The Tat protein of human immunodeficiency virus-1 enhances hepatitis C virus replication through interferon gamma-inducible protein-10

    Directory of Open Access Journals (Sweden)

    Qu Jing

    2012-04-01

    Full Text Available Abstract Background Co-infection with human immunodeficiency virus-1 (HIV-1 and hepatitis C virus (HCV is associated with faster progression of liver disease and an increase in HCV persistence. However, the mechanism by which HIV-1 accelerates the progression of HCV liver disease remains unknown. Results HIV-1/HCV co-infection is associated with increased expression of interferon gamma-induced protein-10 (IP-10 mRNA in peripheral blood mononuclear cells (PBMCs. HCV RNA levels were higher in PBMCs of patients with HIV-1/HCV co-infection than in patients with HCV mono-infection. HIV-1 Tat and IP-10 activated HCV replication in a time-dependent manner, and HIV-1 Tat induced IP-10 production. In addition, the effect of HIV-1 Tat on HCV replication was blocked by anti-IP-10 monoclonal antibody, demonstrating that the effect of HIV-1 Tat on HCV replication depends on IP-10. Taken together, these results suggest that HIV-1 Tat protein activates HCV replication by upregulating IP-10 production. Conclusions HIV-1/HCV co-infection is associated with increased expression of IP-10 mRNA and replication of HCV RNA. Furthermore, both HIV-1 Tat and IP-10 activate HCV replication. HIV-1 Tat activates HCV replication by upregulating IP-10 production. These results expand our understanding of HIV-1 in HCV replication and the mechanism involved in the regulation of HCV replication mediated by HIV-1 during co-infection.

  20. Sequence Variation in Rhoptry Neck Protein 10 Gene among Toxoplasma gondii Isolates from Different Hosts and Geographical Locations.

    Science.gov (United States)

    Zhao, Yu; Zhou, Donghui; Chen, Jia; Sun, Xiaolin

    2017-01-01

    Toxoplasma gondii, as a eukaryotic parasite of the phylum Apicomplexa, can infect almost all the warm-blooded animals and humans, causing toxoplasmosis. Rhoptry neck proteins (RONs) play a key role in the invasion process of T. gondii and are potential vaccine candidate molecules against toxoplasmosis. The present study examined sequence variation in the rhoptry neck protein 10 (TgRON10) gene among 10 T. gondii isolates from different hosts and geographical locations from Lanzhou province during 2014, and compared with the corresponding sequences of strains ME49 and VEG obtained from the ToxoDB database, using polymerase chain reaction (PCR) amplification, sequence analysis, and phylogenetic reconstruction by Bayesian inference (BI) and maximum parsimony (MP). Analysis of all the 12 TgRON10 genomic and cDNA sequences revealed 7 exons and 6 introns in the TgRON10 gDNA. The complete genomic sequence of the TgRON10 gene ranged from 4759 bp to 4763 bp, and sequence variation was 0-0.6% among the 12 T. gondii isolates, indicating a low sequence variation in TgRON10 gene. Phylogenetic analysis of TgRON10 sequences showed that the cluster of the 12 T. gondii isolates was not completely consistent with their respective genotypes. TgRON10 gene is not a suitable genetic marker for the differentiation of T. gondii isolates from different hosts and geographical locations, but may represent a potential vaccine candidate against toxoplasmosis, worth further studies.

  1. Interferon-inducible protein 10 (IP-10) is associated with viremia of early HIV-1 infection in Korean patients.

    Science.gov (United States)

    Lee, SoYong; Chung, Yoon-Seok; Yoon, Cheol-Hee; Shin, YoungHyun; Kim, SeungHyun; Choi, Byeong-Sun; Kim, Sung Soon

    2015-05-01

    Cytokines/chemokines play key roles in modulating disease progression in human immunodeficiency virus (HIV) infection. Although it is known that early HIV-1 infection is associated with increased production of proinflammatory cytokines, the relationship between cytokine levels and HIV-1 pathogenesis is not clear. The concentrations of 18 cytokines/chemokines in 30 HIV-1 negative and 208 HIV-1 positive plasma samples from Korean patients were measured by the Luminex system. Early HIV-1 infection was classified according to the Fiebig stage (FS) based on the characteristics of the patients infected with HIV-1. Concentrations of interleukin-12 (IL-12), interferon-inducible protein-10 (IP-10), macrophage inflammatory protein-1α (MIP-1α) and regulated upon activation, normal T cells expressed and secreted (RANTES) were increased significantly during the early stage of HIV-1 infection (FS II-IV) compared with the HIV-1-negative group. Of these cytokines, an elevated level of IP-10 was the only factor to be correlated positively with a higher viral load during the early stages of HIV-1 infection (FS II-IV) in Koreans (R = 0.52, P IP-10 may be an indicator for HIV-1 viremia and associated closely with viral replication in patients with early HIV-1 infection. © 2015 Wiley Periodicals, Inc.

  2. Application of directly coupled HPLC MMR to separation and characterization of lipoproteins from human serum

    DEFF Research Database (Denmark)

    Daykin, C. A.; Corcoran, O.; Hansen, S. H.

    2001-01-01

    method for the separation of highdensity lipoprotein, low-density lipoprotein, and very low-density lipoprotein from intact serum or plasma. The separation was achieved using a hydroxyapatite column and elution with pH 7.4 phosphate buffer with 100-muL injections of whole plasma. Coelution of HDL...... run time was 90 min with stopped-now 600-MHz NMR spectra of each lipoprotein being collected using 128 scans, in 7 min. The H-1 NMR chemical shifts of lipid signals were identical to conventional NMR spectra of freshly prepared lipoprotein standards, confirming that the lipoproteins were not degraded...

  3. Triglyceride-Rich Lipoproteins and Atherosclerotic Cardiovascular Disease

    DEFF Research Database (Denmark)

    Nordestgaard, Børge G

    2016-01-01

    Scientific interest in triglyceride-rich lipoproteins has fluctuated over the past many years, ranging from beliefs that these lipoproteins cause atherosclerotic cardiovascular disease (ASCVD) to being innocent bystanders. Correspondingly, clinical recommendations have fluctuated from a need.......1-fold for myocardial infarction, 3.2-fold for ischemic heart disease, 3.2-fold for ischemic stroke, and 2.2-fold for all-cause mortality. Also, genetic studies using the Mendelian randomization design, an approach that minimizes problems with confounding and reverse causation, now demonstrate...

  4. Identification and Localization of Myxococcus xanthus Porins and Lipoproteins

    Science.gov (United States)

    Bhat, Swapna; Zhu, Xiang; Patel, Ricky P.; Orlando, Ron; Shimkets, Lawrence J.

    2011-01-01

    Myxococcus xanthus DK1622 contains inner (IM) and outer membranes (OM) separated by a peptidoglycan layer. Integral membrane, β-barrel proteins are found exclusively in the OM where they form pores allowing the passage of nutrients, waste products and signals. One porin, Oar, is required for intercellular communication of the C-signal. An oar mutant produces CsgA but is unable to ripple or stimulate csgA mutants to develop suggesting that it is the channel for C-signaling. Six prediction programs were evaluated for their ability to identify β-barrel proteins. No program was reliable unless the predicted proteins were first parsed using Signal P, Lipo P and TMHMM, after which TMBETA-SVM and TMBETADISC-RBF identified β-barrel proteins most accurately. 228 β-barrel proteins were predicted from among 7331 protein coding regions, representing 3.1% of total genes. Sucrose density gradients were used to separate vegetative cell IM and OM fractions, and LC-MS/MS of OM proteins identified 54 β-barrel proteins. Another class of membrane proteins, the lipoproteins, are anchored in the membrane via a lipid moiety at the N-terminus. 44 OM proteins identified by LC-MS/MS were predicted lipoproteins. Lipoproteins are distributed between the IM, OM and ECM according to an N-terminal sorting sequence that varies among species. Sequence analysis revealed conservation of alanine at the +7 position of mature ECM lipoproteins, lysine at the +2 position of IM lipoproteins, and no noticable conservation within the OM lipoproteins. Site directed mutagenesis and immuno transmission electron microscopy showed that alanine at the +7 position is essential for sorting of the lipoprotein FibA into the ECM. FibA appears at normal levels in the ECM even when a +2 lysine is added to the signal sequence. These results suggest that ECM proteins have a unique method of secretion. It is now possible to target lipoproteins to specific IM, OM and ECM locations by manipulating the amino acid

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-12-01

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

  6. LDL receptor-related protein 1 regulates the abundance of diverse cell-signaling proteins in the plasma membrane proteome.

    Science.gov (United States)

    Gaultier, Alban; Simon, Gabriel; Niessen, Sherry; Dix, Melissa; Takimoto, Shinako; Cravatt, Benjamin F; Gonias, Steven L

    2010-12-03

    LDL receptor-related protein 1 (LRP1) is an endocytic receptor, reported to regulate the abundance of other receptors in the plasma membrane, including uPAR and tissue factor. The goal of this study was to identify novel plasma membrane proteins, involved in cell-signaling, that are regulated by LRP1. Membrane protein ectodomains were prepared from RAW 264.7 cells in which LRP1 was silenced and control cells using protease K. Peptides were identified by LC-MS/MS. By analysis of spectral counts, 31 transmembrane and secreted proteins were regulated in abundance at least 2-fold when LRP1 was silenced. Validation studies confirmed that semaphorin4D (Sema4D), plexin domain-containing protein-1 (Plxdc1), and neuropilin-1 were more abundant in the membranes of LRP1 gene-silenced cells. Regulation of Plxdc1 by LRP1 was confirmed in CHO cells, as a second model system. Plxdc1 coimmunoprecipitated with LRP1 from extracts of RAW 264.7 cells and mouse liver. Although Sema4D did not coimmunoprecipitate with LRP1, the cell-surface level of Sema4D was increased by RAP, which binds to LRP1 and inhibits binding of other ligands. These studies identify Plxdc1, Sema4D, and neuropilin-1 as novel LRP1-regulated cell-signaling proteins. Overall, LRP1 emerges as a generalized regulator of the plasma membrane proteome.

  7. Smooth muscle LDL receptor-related protein-1 deletion induces aortic insufficiency and promotes vascular cardiomyopathy in mice.

    Directory of Open Access Journals (Sweden)

    Joshua E Basford

    Full Text Available Valvular disease is common in patients with Marfan syndrome and can lead to cardiomyopathy. However, some patients develop cardiomyopathy in the absence of hemodynamically significant valve dysfunction, suggesting alternative mechanisms of disease progression. Disruption of LDL receptor-related protein-1 (Lrp1 in smooth muscle cells has been shown to cause vascular pathologies similar to Marfan syndrome, with activation of smooth muscle cells, vascular dysfunction and aortic aneurysms. This study used echocardiography and blood pressure monitoring in mouse models to determine whether inactivation of Lrp1 in vascular smooth muscle leads to cardiomyopathy, and if so, whether the mechanism is a consequence of valvular disease. Hemodynamic changes during treatment with captopril were also assessed. Dilation of aortic roots was observed in young Lrp1-knockout mice and progressed as they aged, whereas no significant aortic dilation was detected in wild type littermates. Diastolic blood pressure was lower and pulse pressure higher in Lrp1-knockout mice, which was normalized by treatment with captopril. Aortic dilation was followed by development of aortic insufficiency and subsequent dilated cardiomyopathy due to valvular disease. Thus, smooth muscle cell Lrp1 deficiency results in aortic dilation and insufficiency that causes secondary cardiomyopathy that can be improved by captopril. These findings provide novel insights into mechanisms of cardiomyopathy associated with vascular activation and offer a new model of valvular cardiomyopathy.

  8. Connective Tissue Growth Factor Domain 4 Amplifies Fibrotic Kidney Disease through Activation of LDL Receptor-Related Protein 6.

    Science.gov (United States)

    Johnson, Bryce G; Ren, Shuyu; Karaca, Gamze; Gomez, Ivan G; Fligny, Cécile; Smith, Benjamin; Ergun, Ayla; Locke, George; Gao, Benbo; Hayes, Sebastian; MacDonnell, Scott; Duffield, Jeremy S

    2017-06-01

    Connective tissue growth factor (CTGF), a matrix-associated protein with four distinct cytokine binding domains, has roles in vasculogenesis, wound healing responses, and fibrogenesis and is upregulated in fibroblasts and myofibroblasts in disease. Here, we investigated the role of CTGF in fibrogenic cells. In mice, tissue-specific inducible overexpression of CTGF by kidney pericytes and fibroblasts had no bearing on nephrogenesis or kidney homeostasis but exacerbated inflammation and fibrosis after ureteral obstruction. These effects required the WNT receptor LDL receptor-related protein 6 (LRP6). Additionally, pericytes isolated from these mice became hypermigratory and hyperproliferative on overexpression of CTGF. CTGF is cleaved in vivo into distinct domains. Treatment with recombinant domain 1, 1+2 (N terminus), or 4 (C terminus) independently activated myofibroblast differentiation and wound healing responses in cultured pericytes, but domain 4 showed the broadest profibrotic activity. Domain 4 exhibited low-affinity binding to LRP6 in in vitro binding assays, and inhibition of LRP6 or critical signaling cascades downstream of LRP6, including JNK and WNT/ β -catenin, inhibited the biologic activity of domain 4. Administration of blocking antibodies specifically against CTGF domain 4 or recombinant Dickkopf-related protein-1, an endogenous inhibitor of LRP6, effectively inhibited inflammation and fibrosis associated with ureteral obstruction in vivo Therefore, domain 4 of CTGF and the WNT signaling pathway are important new targets in fibrosis. Copyright © 2017 by the American Society of Nephrology.

  9. Effects of human low and high density lipoproteins on the binding of rat intermediate density lipoproteins to rat liver membranes

    International Nuclear Information System (INIS)

    Brissette, L.; Nol, S.P.

    1986-01-01

    Upon incubation with rat liver membranes, radioiodinated rat intermediate density lipoproteins (IDL) interacted with at least two binding sites having a low and a high affinity as demonstrated by the curvilinear Scatchard plots obtained from the specific binding data. The purpose of our work was to identify the nature of these binding sites. Human low density lipoproteins (LDL), contain apolipoprotein B only, and human high density lipoproteins (HDL3), containing neither apolipoprotein B nor E, were both capable of decreasing the specific binding of rat 125 I-IDL. The Scatchard analysis clearly revealed that only the low affinity component was affected by the addition of these human lipoproteins. In fact, the low affinity binding component gradually decreased as the amount of human LDL or HDL3 increased in the binding assay. At a 200-fold excess of human LDL or HDL3, the low affinity binding was totally masked, and the Scatchard plot of the specific 125 I-IDL binding became linear. Only the high affinity binding component was left, enabling a precise measurement of its binding parameters. In a series of competitive displacement experiments in which the binding assay contained a 200-fold excess of human LDL or HDL3, only unlabeled rat IDL effectively displaced the binding of rat 125 I-IDL. We conclude that the low affinity binding of rat IDL to rat liver membranes is due to weak interactions with unspecified lipoprotein binding sites. The camouflage of these sites by human lipoproteins makes possible the study of IDL binding to the high affinity component which likely represents the combined effect of IDL binding to both the remnant and the LDL receptors

  10. One precursor, three apolipoproteins: the relationship between two crustacean lipoproteins, the large discoidal lipoprotein and the high density lipoprotein/β-glucan binding protein.

    Science.gov (United States)

    Stieb, Stefanie; Roth, Ziv; Dal Magro, Christina; Fischer, Sabine; Butz, Eric; Sagi, Amir; Khalaila, Isam; Lieb, Bernhard; Schenk, Sven; Hoeger, Ulrich

    2014-12-01

    The novel discoidal lipoprotein (dLp) recently detected in the crayfish, differs from other crustacean lipoproteins in its large size, apoprotein composition and high lipid binding capacity, We identified the dLp sequence by transcriptome analyses of the hepatopancreas and mass spectrometry. Further de novo assembly of the NGS data followed by BLAST searches using the sequence of the high density lipoprotein/1-glucan binding protein (HDL-BGBP) of Astacus leptodactylus as query revealed a putative precursor molecule with an open reading frame of 14.7 kb and a deduced primary structure of 4889 amino acids. The presence of an N-terminal lipid bind- ing domain and a DUF 1943 domain suggests the relationship with the large lipid transfer proteins. Two-putative dibasic furin cleavage sites were identified bordering the sequence of the HDL-BGBP. When subjected to mass spectroscopic analyses, tryptic peptides of the large apoprotein of dLp matched the N-terminal part of the precursor, while the peptides obtained for its small apoprotein matched the C-terminal part. Repeating the analysis in the prawn Macrobrachium rosenbergii revealed a similar protein with identical domain architecture suggesting that our findings do not represent an isolated instance. Our results indicate that the above three apolipoproteins (i.e HDL-BGBP and both the large and the small subunit of dLp) are translated as a large precursor. Cleavage at the furin type sites releases two subunits forming a heterodimeric dLP particle, while the remaining part forms an HDL-BGBP whose relationship with other lipoproteins as well as specific functions are yet to be elucidated.

  11. Interferon-γ-inducible protein-10 in chronic hepatitis C: Correlations with insulin resistance, histological features & sustained virological response.

    Science.gov (United States)

    Crisan, Dana; Grigorescu, Mircea Dan; Radu, Corina; Suciu, Alina; Grigorescu, Mircea

    2017-04-01

    One of the multiple factors contributing to virological response in chronic hepatitis C (CHC) is interferon-gamma-inducible protein-10 (IP-10). Its level reflects the status of interferon-stimulated genes, which in turn is associated with virological response to antiviral therapy. The aim of this study was to evaluate the role of serum IP-10 levels on sustained virological response (SVR) and the association of this parameter with insulin resistance (IR) and liver histology. Two hundred and three consecutive biopsy proven CHC patients were included in the study. Serum levels of IP-10 were determined using ELISA method. IR was evaluated by homeostasis model assessment-IR (HOMA-IR). Histological features were assessed invasively by liver biopsy and noninvasively using FibroTest, ActiTest and SteatoTest. Predictive factors for SVR and their interrelations were assessed. A cut-off value for IP-10 of 392 pg/ml was obtained to discriminate between responders and non-responders. SVR was obtained in 107 patients (52.70%). Area under the receiver operating characteristic curve for SVR was 0.875 with a sensitivity of 91.6 per cent, specificity 74.7 per cent, positive predictive value 80.3 per cent and negative predictive value 88.7 per cent. Higher values of IP-10 were associated with increasing stages of fibrosis (P<0.01) and higher grades of inflammation (P=0.02, P=0.07) assessed morphologically and noninvasively through FibroTest and ActiTest. Significant steatosis and IR were also associated with increased levels of IP-10 (P=0.01 and P=0.02). In multivariate analysis, IP-10 levels and fibrosis stages were independently associated with SVR. Our findings showed that the assessment of serum IP-10 level could be a predictive factor for SVR and it was associated with fibrosis, necroinflammatory activity, significant steatosis and IR in patients with chronic HCV infection.

  12. Sequence Variation in Rhoptry Neck Protein 10 Gene among Toxoplasma gondii Isolates from Different Hosts and Geographical Locations

    Directory of Open Access Journals (Sweden)

    Yu ZHAO

    2017-09-01

    Full Text Available Background: Toxoplasma gondii, as a eukaryotic parasite of the phylum Apicomplexa, can infect almost all the warm-blooded animals and humans, causing toxoplasmosis. Rhoptry neck proteins (RONs play a key role in the invasion process of T. gondii and are potential vaccine candidate molecules against toxoplasmosis.Methods: The present study examined sequence variation in the rhoptry neck protein 10 (TgRON10 gene among 10 T. gondii isolates from different hosts and geographical locations from Lanzhou province during 2014, and compared with the corresponding sequences of strains ME49 and VEG obtained from the ToxoDB database, using polymerase chain reaction (PCR amplification, sequence analysis, and phylogenetic reconstruction by Bayesian inference (BI and maximum parsimony (MP. Results: Analysis of all the 12 TgRON10 genomic and cDNA sequences revealed 7 exons and 6 introns in the TgRON10 gDNA. The complete genomic sequence of the TgRON10 gene ranged from 4759 bp to 4763 bp, and sequence variation was 0-0.6% among the 12 T. gondii isolates, indicating a low sequence variation in TgRON10 gene. Phylogenetic analysis of TgRON10 sequences showed that the cluster of the 12 T. gondii isolates was not completely consistent with their respective genotypes.Conclusion: TgRON10 gene is not a suitable genetic marker for the differentiation of T. gondii isolates from different hosts and geographical locations, but may represent a potential vaccine candidate against toxoplasmosis, worth further studies.

  13. Human plasma phospholipid transfer protein increases the antiatherogenic potential of high density lipoproteins in transgenic mice

    NARCIS (Netherlands)

    M.J. van Haperen (Rien); A. van Tol (Arie); P. Vermeulen; M. Jauhiainen; T. van Gent (Teus); P.M. van den Berg (Paul); S. Ehnholm (Sonja); A.W.M. van der Kamp (Arthur); M.P.G. de Crom (Rini); F.G. Grosveld (Frank)

    2000-01-01

    textabstractPlasma phospholipid transfer protein (PLTP) transfers phospholipids between lipoprotein particles and alters high density lipoprotein (HDL) subfraction patterns in vitro, but its physiological function is poorly understood. Transgenic mice that overexpress

  14. The effect of interaction between Lipoprotein Lipase and ApoVLDL-II ...

    African Journals Online (AJOL)

    GREGO

    2007-04-02

    Apr 2, 2007 ... correlation between growth and fitness is not absolute, it ... significant differences are found in the plasma triglyceride ... (VLDL) and high density lipoprotein (HDL) concentration ... High-density lipoprotein cholesterol was.

  15. High-density lipoproteins and adrenal steroidogenesis : A population-based study

    NARCIS (Netherlands)

    Buitenwerf, Edward; Kerstens, Michiel N.; Links, Thera P.; Kema, Ido P.; Dullaart, Robin P. F.

    BACKGROUND: Cholesterol trafficked within plasma lipoproteins, in particular high-density lipoproteins (HDL), may represent an important source of cholesterol that is required for adrenal steroidogenesis. Based on a urinary gas chromatography method, compromised adrenal function has been suggested

  16. Atherogenic lipoprotein particle size and concentrations and the effect of pravastatin in children with familial hypercholesterolemia

    NARCIS (Netherlands)

    van der Graaf, Anouk; Rodenburg, Jessica; Vissers, Maud N.; Hutten, Barbara A.; Wiegman, Albert; Trip, Mieke D.; Stroes, Erik S. G.; Wijburg, Frits A.; Otvos, James D.; Kastelein, John J. P.

    2008-01-01

    OBJECTIVE: To determine lipoprotein particle concentrations and size in children with familial hypercholesterolemia (FH) and investigate the effect of pravastatin therapy on these measures. STUDY DESIGN: Lipoprotein particle concentrations and sizes were examined by nuclear magnetic resonance (NMR)

  17. Serum lipid and lipoprotein patterns of Iranian horses.

    Science.gov (United States)

    Asadi, F; Asadian, P; Shahriari, A; Pourkabir, M; Kazemi, A

    2011-12-01

    Patterns of serum biochemical parameters vary among horse breeds. The objective of the present study was to compare serum lipoproteins of Iranian Caspian ponies with those of other horses (Arabs and Thoroughbreds) in the Iranian region. Serum lipoprotein values were determined by agar-agarose gel electrophoresis and measured by scan densitometry. Moreover, serum triglyceride and cholesterol concentrations were determined and the results were analysed by one-way analysis of variance. Serum triglyceride and cholesterol values were 1.13 +/- 0.23 and 2.38 +/- 0.18 mmol/l in Caspian ponies, 1.96 +/- 0.49 and 1.92 +/- 0.25 mmol/l in Arab horses and 1.38 +/- 0.26 and 2.17 +/- 0.53 mmol/l in Thoroughbred horses. The relative percentages of alpha- (72.63 +/- 17.76%) and beta-lipoproteins (29.10 +/- 5.49%) in serum electrophoretic tracings from Caspian ponies were not significantly different from those of other horses (p > 0.05). The lipoprotein phenotype in Caspian ponies may be useful for evaluating metabolic diseases.

  18. Low-density lipoprotein cholesterol and risk of gallstone disease

    DEFF Research Database (Denmark)

    Stender, Stefan; Frikke-Schmidt, Ruth; Benn, Marianne

    2013-01-01

    Drugs which reduce plasma low-density lipoprotein cholesterol (LDL-C) may protect against gallstone disease. Whether plasma levels of LDL-C per se predict risk of gallstone disease remains unclear. We tested the hypothesis that elevated LDL-C is a causal risk factor for symptomatic gallstone...

  19. PCSK9 and triglyceride-rich lipoprotein metabolism.

    Science.gov (United States)

    Druce, I; Abujrad, H; Ooi, T C

    2015-07-20

    Pro-protein convertase subtilisin-kexin 9 (PCSK9) is known to affect low-density lipoprotein (LDL) metabolism, but there are indications from several lines of research that it may also influence the metabolism of other lipoproteins, especially triglyceride-rich lipoproteins (TRL). This review summarizes the current data on this possible role of PCSK9. A link between PCSK9 and TRL has been suggested through the demonstration of (1) a correlation between plasma PCSK9 and triglyceride (TG) levels in health and disease, (2) a correlation between plasma PCSK9 and markers of carbohydrate metabolism, which is closely related to TG metabolism, (3) an effect of TG-lowering fibrate therapy on plasma PCSK9 levels, (4) an effect of PCSK9 on postprandial lipemia, (5) an effect of PCSK9 on adipose tissue biology, (6) an effect of PCSK9 on apolipoprotein B production from the liver and intestines, (7) an effect of PCSK9 on receptors other than low density lipoprotein receptor (LDLR) that are involved in TRL metabolism, and (8) an effect of anti-PCSK9 therapy on serum TG levels. The underlying mechanisms are unclear but starting to emerge. © 2015 the Journal of Biomedical Research. All rights reserved.

  20. Lipoprotein(a) accelerates atherosclerosis in uremic mice

    DEFF Research Database (Denmark)

    Pedersen, Tanja X; McCormick, Sally P; Tsimikas, Sotirios

    2010-01-01

    Uremic patients have increased plasma lipoprotein(a) [Lp(a)] levels and elevated risk of cardiovascular disease. Lp(a) is a subfraction of LDL, where apolipoprotein(a) [apo(a)] is disulfide bound to apolipoprotein B-100 (apoB). Lp(a) binds oxidized phospholipids (OxPL), and uremia increases lipop...

  1. Increased oxidizability of low-density lipoproteins in hypothyroidism

    NARCIS (Netherlands)

    Diekman, T.; Demacker, P. N.; Kastelein, J. J.; Stalenhoef, A. F.; Wiersinga, W. M.

    1998-01-01

    Hypothyroidism leads to an increase of plasma low-density lipoprotein (LDL) cholesterol levels. Oxidation of LDL particles changes their intrinsic properties, thereby enhancing the development of atherosclerosis. T4 has three specific binding sites on apolipoprotein B; furthermore it inhibits LDL

  2. Role of oxidized low-density lipoprotein in renal disease

    NARCIS (Netherlands)

    Heeringa, P; Tervaert, JWC

    Accelerated atherosclerosis is often observed in patients with chronic renal failure. In the present review we summarize and discuss the recent literature on the pathogenic role of low-density lipoproteins modified by oxidative processes in atherosclerosis and the possible role in renal diseases.

  3. Antioxidant activity of high-density lipoprotein (HDL) using different ...

    African Journals Online (AJOL)

    HDL is a potent antioxidant in terms of inhibition of lipid peroxidation, ROS production and LDL oxidation. These may to some extent add to the antiatherogenic beyond reverse-cholesterol transport properties of HDL. Keywords: high-density lipoprotein; reverse cholesterol transport; apolipoprotein A1; antioxidant; in vitro.

  4. [Residual risk: The roles of triglycerides and high density lipoproteins].

    Science.gov (United States)

    Grammer, Tanja; Kleber, Marcus; Silbernagel, Günther; Scharnagl, Hubert; März, Winfried

    2016-06-01

    In clinical trials, the reduction of LDL-cholesterol (LDL-C) with statins reduces the incidence rate of cardiovascular events by approximately one third. This means, that a sizeable "residual risk" remains. Besides high lipoprotein (a), disorders in the metabolism of triglyceride-rich lipoproteins and high density liproteins have been implicated as effectors of the residual risk. Both lipoprotein parameters correlate inversely with each other. Therefore, the etiological contributions of triglycerides and / or of HDL for developing cardiovascular disease can hardly be estimated from either observational studies or from intervention studies. The largely disappointing results of intervention studies with inhibitors of the cholesteryl ester transfer protein and in particular the available set of genetically-epidemiological studies suggest that in the last decade, the importance of HDL cholesterol has been overvalued, while the importance of triglycerides has been underestimated. High triglycerides not always atherogenic, but only if they are associated with the accumulation relatively cholesterol-enriched, incompletely catabolized remnants of chylomicrons and very low density lipoproteins (familial type III hyperlipidemia, metabolic syndrome, diabetes mellitus). The normalization of the concentration of triglycerides and remnants by inhibiting the expression of apolipoprotein C3 is hence a new, promising therapeutic target. © Georg Thieme Verlag KG Stuttgart · New York.

  5. Lifecycle of a Lipoprotein from a Biophysical Perspective

    Science.gov (United States)

    Rutledge, John C.; Huser, Thomas; Voss, John; Chan, James; Parikh, Atul

    The goal of our project was to understand how lipids and lipoproteins interact with cell membranes. This chapter will present the five major areas in which we have focused our attention on understanding how lipids and lipoproteins interact with cell membranes (Fig. 11.1): (1) triglycerides and vascular injury, (2) single lipoprotein analysis, (3) apolipoprotein E (apoE) conformation changes in the postprandial state, (4) triglyceride-rich lipoproteins (TGRLs) and endothelial cell inflammation, and (5) TGRL lipolysis products and monocyte activation. For over a hundred years, Western civilization has questioned how the food we eat translates into disease, and specifically atherosclerotic cardiovascular disease. Although most information indicates that this basic pathophysiological process is mediated through consumption of excess saturated fats, much remains unknown. After humans eat a meal, there is an elevation of triglycerides in the blood in the postprandial state. In normal individuals, triglycerides can rise after a meal by 50 to 100%. This has been documented many times in the past, including a paper by Hyson et al, (1998) [1]. In that study, normal healthy individuals were given a 40%-fat meal. Plasma triglycerides, which were modestly elevated initially, rose about 60% higher three to four hours after ingestion of the meal. Subsequently plasma triglycerides fell to baseline levels six hours after the meal. Even in these healthy individuals, a significant elevation of triglycerides was noted after ingestion of a moder ately high-fat meal.

  6. Dietary oils, serum lipoproteins, and coronary heart disease.

    NARCIS (Netherlands)

    Katan, M.B.; Zock, P.L.; Mensink, R.P.

    1995-01-01

    Variable amounts of olive oil rather than hard fats were used in classic Mediterranean diets. We review the effects of replacing hard fats with olive oils or starchy foods on blood lipoprotein concentrations. The saturated fatty acids lauric, myristic, and palmitic acids raise both low-density

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

    DEFF Research Database (Denmark)

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

    2004-01-01

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

  8. Lipoprotein Lipase Maintains Microglial Innate Immunity in Obesity

    NARCIS (Netherlands)

    Gao, Yuanqing; Vidal-Itriago, Andrés; Kalsbeek, Martin J; Layritz, Clarita; García-Cáceres, Cristina; Tom, Robby Zachariah; Eichmann, Thomas O; Vaz, Frédéric M; Houtkooper, Riekelt H; van der Wel, Nicole; Verhoeven, Arthur J; Yan, Jie; Kalsbeek, A.; Eckel, Robert H; Hofmann, Susanna M; Yi, Chun-Xia

    2017-01-01

    Consumption of a hypercaloric diet upregulates microglial innate immune reactivity along with a higher expression of lipoprotein lipase (Lpl) within the reactive microglia in the mouse brain. Here, we show that knockdown of the Lpl gene specifically in microglia resulted in deficient microglial

  9. Role of Lipids in Spheroidal High Density Lipoproteins

    NARCIS (Netherlands)

    Vuorela, Timo; Catte, Andrea; Niemela, Perttu S.; Hall, Anette; Hyvonen, Marja T.; Marrink, Siewert-Jan; Karttunen, Mikko; Vattulainen, Ilpo

    2010-01-01

    We study the structure and dynamics of spherical high density lipoprotein (HDL) particles through coarse-grained multi-microsecond molecular dynamics simulations. We simulate both a lipid droplet without the apolipoprotein A-I (apoA-I) and the full HDL particle including two apoA-I molecules

  10. Role of lipids in spheroidal high density lipoproteins

    NARCIS (Netherlands)

    Vuorela, T.A.; Catte, A.; Niemelä, P.S.; Hall, A.; Hyvönen, M.T.; Marrink, S.J.; Karttunen, M.E.J.; Vattulainen, I.

    2010-01-01

    We study the structure and dynamics of spherical high density lipoprotein (HDL) particles through coarse-grained multi-microsecond molecular dynamics simulations. We simulate both a lipid droplet without the apolipoprotein A-I (apoA-I) and the full HDL particle including two apoA-I molecules

  11. High density lipoproteins, dyslipidemia, and coronary heart disease

    National Research Council Canada - National Science Library

    2010-01-01

    ... with premature coronary heart disease (CHD). These familial disorders include lipoprotein(a) excess, dyslipidemia (high triglycerides and low HDL), combined hyperlipidemia (high cholesterol and high triglycerides often with low HDL), hypoalphalipoproteinemia (low HDL), and hypercholesterolemia. We discuss the management of these disorders. W...

  12. Serum lipids and lipoproteins in patients with psoriasis.

    Science.gov (United States)

    Taheri Sarvtin, Mehdi; Hedayati, Mohammad Taghi; Shokohi, Tahereh; HajHeydari, Zohreh

    2014-05-01

    Psoriasis is a common chronic and recurrent inflammatory skin disorder characterized by hyperproliferation of keratinocytes and infiltration of T cells, monocytes/macrophages and neutrophils into dermal and epidermal layers of the skin. The prevalence of cardiovascular disorders in these patients is remarkably higher compared to normal individuals, which seems to be associated with the hyperlipidemia. This study was designed and conducted to investigate the serum lipid profile in psoriatic patients and its association with the severity of disease. This case-control study was performed on 50 plaque-type psoriasis patients and 50 healthy individuals as control, matched for age and sex. Blood samples were collected after 14 h fasting. Serum triglyceride, cholesterol and lipoproteins were assayed using the standard kit (made by Pars Azmon Co. Iran). Certain parameters, including serum triglyceride, cholesterol, low density lipoprotein (LDL), and very low density lipoprotein (VLDL), were significantly higher in the case group compared to the controls (P lipoprotein (HDL) was significantly lower in the former (P < 0.001). In addition, there was a significant relationship between severity of psoriasis and serum lipid profile. The results have revealed the higher plasma level of lipids in psoriatic patients. This may elevate the risk of atherosclerosis, particularly cardiovascular disorders. Therefore, from the epidemiological point of view, screening psoriatic patients, particularly those with severe psoriasis, is recommended.

  13. Evaluation of plasma lipids and lipoproteins in nigerians suffering ...

    African Journals Online (AJOL)

    There are conflicting reports on the role of plasma lipids in depressive illness. Very little is known about the lipid and lipoprotein status in Nigerian adults suffering from depression. One hundred subjects consisting of sixty (60) depressed patients with mean age (40.3±12.3 yrs) and forty (40) apparently healthy controls ...

  14. Evaluation of Homocysteine, Lipoprotein(a) and Endothelin as ...

    African Journals Online (AJOL)

    Indians have been reported to have high prevalence rates of coronary artery disease (CAD) even in the absence of traditional risk factors. The objective of this study was to assess the role of endothelin, lipoprotein(a), homocysteine and lipid profile as markers of CAD in Indian population. It was a hospital based ...

  15. Inhibition of endothelial lipase activity by sphingomyelin in the lipoproteins.

    Science.gov (United States)

    Yang, Peng; Belikova, Natalia A; Billheimer, Jeff; Rader, Daniel J; Hill, John S; Subbaiah, Papasani V

    2014-10-01

    Endothelial lipase (EL) is a major determinant of plasma HDL concentration, its activity being inversely proportional to HDL levels. Although it is known that it preferentially acts on HDL compared to LDL and VLDL, the basis for this specificity is not known. Here we tested the hypothesis that sphingomyelin, a major phospholipid in lipoproteins is a physiological inhibitor of EL, and that the preference of the enzyme for HDL may be due to low sphingomyelin/phosphatidylcholine (PtdCho) ratio in HDL, compared to other lipoproteins. Using recombinant human EL, we showed that sphingomyelin inhibits the hydrolysis of PtdCho in the liposomes in a concentration-dependent manner. While the enzyme showed lower hydrolysis of LDL PtdCho, compared to HDL PtdCho, this difference disappeared after the degradation of lipoprotein sphingomyelin by bacterial sphingomyelinase. Analysis of molecular species of PtdCho hydrolyzed by EL in the lipoproteins showed that the enzyme preferentially hydrolyzed PtdCho containing polyunsaturated fatty acids (PUFA) such as 22:6, 20:5, 20:4 at the sn-2 position, generating the corresponding PUFA-lyso PtdCho. This specificity for PUFA-PtdCho species was not observed after depletion of sphingomyelin by sphingomyelinase. These results show that sphingomyelin not only plays a role in regulating EL activity, but also influences its specificity towards PtdCho species.

  16. Epidemiological reference ranges for low-density lipoprotein ...

    African Journals Online (AJOL)

    Although there is widespread acceptance that total cholesterol (TC) value reference ranges should be based on epidemiological rather than statistical considerations, the epidemiological action limits for Iow-density lipoprotein cholesterol (LDL-C) are still incomplete and only statistical reference ranges for apolipoprotein B ...

  17. Serum Lipids and Lipoproteins Levels and Selected Trace Metals In ...

    African Journals Online (AJOL)

    This study aim to determine the serum levels of trace metals and correlate same with serum levels of lipoproteins (an established marker of HBP) in newly diagnosed hypertensives (NDH) A total of 50 NDH subjects (24 males and 26 females) attending Ladoke Akintola University of Technology Teaching Hospital, Osogbo ...

  18. Pneumococcal lipoproteins involved in bacterial fitness, virulence, and immune evasion.

    Science.gov (United States)

    Kohler, Sylvia; Voß, Franziska; Gómez Mejia, Alejandro; Brown, Jeremy S; Hammerschmidt, Sven

    2016-11-01

    Streptococcus pneumoniae (pneumococcus) has evolved sophisticated strategies to survive in several niches within the human body either as a harmless commensal or as a serious pathogen causing a variety of diseases. The dynamic interaction between pneumococci and resident host cells during colonization of the upper respiratory tract and at the site of infection is critical for bacterial survival and the development of disease. Pneumococcal lipoproteins are peripherally anchored membrane proteins and have pivotal roles in bacterial fitness including envelope stability, cell division, nutrient acquisition, signal transduction, transport (as substrate-binding proteins of ABC transporter systems), resistance to oxidative stress and antibiotics, and protein folding. In addition, lipoproteins are directly involved in virulence-associated processes such as adhesion, colonization, and persistence through immune evasion. Conversely, lipoproteins are also targets for the host response both as ligands for toll-like receptors and as targets for acquired antibodies. This review summarizes the multifaceted roles of selected pneumococcal lipoproteins and how this knowledge can be exploited to combat pneumococcal infections. © 2016 Federation of European Biochemical Societies.

  19. Proton nuclear magnetic resonance spectroscopy of plasma lipoproteins in malignancy

    International Nuclear Information System (INIS)

    Nabholtz, J.M.; Rossignol, A.; Farnier, M.; Gambert, P.; Tremeaux, J.C.; Friedman, S.; Guerrin, J.

    1988-01-01

    A recent study described a method of detecting malignant tumors by water-supressed proton nuclear magnetic resonance (1 H NMR) study of plasma. We performed a similar study of the W 1/2, a mean of the full width at half height of the resonances of the methyl and methylene groups of the lipids of plasma lipoproteins which is inversely related to the spin-spin apparent relaxation time (T 2 * ). W 1/2 values were measured at a fixed baseline width of 310 Hz. The study was prospective and blinded and comprised 182 subjects consisting of 40 controls, 68 patients with untreated malignancies, 45 with malignant tumors undergoing therapy and 29 benign tumor patients. No differences were seen between any groups that could serve as a basis for a useful clinical test. The major difficulty in the determination of W 1/2 was due to interference of metabolite protons (particularly lactate) within the lipoprotein resonance signal. Triglyceride level was seen to correlate inversely with W 1/2 within malignant patient groups. These discrepant results may be related to differing triglyceride-rich very low density lipoprotein (VLDL) levels in the ;atient populations of each study. We conclude that the water-suppressed 1H NMR of plasma lipoproteins is not a valid measurement for assessing malignancy. (orig.)

  20. Human Low Density Lipoprotein as a Vehicle of Atherosclerosis ...

    African Journals Online (AJOL)

    Low-density lipoproteins have been sufficiently established as an important precursor of atherosclerosis. The actual mechanism is still unclear, and the current technique of using radioisotopes has clinical limitation. However, the current study techniques or methods excellently elucidate the functional aspects of ...

  1. Serum Lipid and Lipoprotein Profile in Nigerian Patients with ...

    African Journals Online (AJOL)

    Purpose: To evaluate the changes in lipid and lipoprotein patterns in adult patients with haematological cancers with any possible risk of cardiovascular event. Patients and Methods: The clinico-pathological types of haematological cancers, body mass index and ages of the of all 74 haematological cancer patients attending ...

  2. Peri and Postparturient Concentrations of Lipid Lipoprotein Insulin and Glucose in Normal Dairy Cows

    OpenAIRE

    BAŞOĞLU, Abdullah; SEVİNÇ, Mutlu; OK, Mahmut

    1998-01-01

    In order to provide uniqe insight into the metabolic disturbences seen after calving cholesterol, triglycerid, high density lipoprotein, low density lipoprotein, very low density lipoprotein, glucose and insulin levels in serum were studied before calving (group I), in aerly (group II) and late (group III) lactation in 24 normal cows. Serum lipoproteins were separeted into various density classes by repeated ultracentrifugation. The results indicate that there was a rise in glucose, trygl...

  3. Elevated Lipoprotein(A Impairs Platelet Radiolabeling Yield

    Directory of Open Access Journals (Sweden)

    Susanne Granegger

    2015-02-01

    Full Text Available Objectives: Platelet radiolabeling in clinical routine usually results in labeling efficiencies (LE above 80%. A variety of risk factors and clinical conditions are known to impair platelet labeling yield, among them elevated triglycerides and low-density lipoproteins. The potential influence of lipoprotein(a (Lp(a, an atherogenic lipoprotein particle containing a kringle subunit, which is widely found in the proteins of fibrinolysis pathway, has never been studied. Normal Lp(a levels range below 30 mg/ dl. The exact prevalence of elevated Lp(a is unknown, most likely ranging below 10%. Even more rare is an isolated elevation despite an otherwise normal lipoprotein profile. Methods: We examined the role of isolated elevated Lp(a (> 50 mg/dl, ranging up to 440 mg/dl compared to patients with normal lipid profile. Platelets were radiolabeled with in-111-oxine at 37 °C for 5 minutes using ISORBE-consensus methodology. Results: The findings indicate that already at levels below 100 mg/dl Lp(a decreases LE. LE assessment after cross-incubation of hyper-Lp(a platelets with normal Lp(a plasma and vice versa reveals that platelets rather than the plasmatic environment are responsible for the deterioration of labeling yield. This behavior already has been reported for elevated low-density lipoproteins. Apparently, the quantitative influence of LDL and Lp(a/mg is comparable. Plotting the sum of LDL and Lp(a versus LE reveals a clear significant negative correlation. Conclusion: As extremely elevated Lp(a, particularly above 150 mg/dl, may significantly impair labeling results. We therefore recommend to include extremely elevated Lp(a into the list of parameters, which should be known before performing radiolabeling of human platelets.

  4. The biological properties of iron oxide core high-density lipoprotein in experimental atherosclerosis

    NARCIS (Netherlands)

    Skajaa, Torjus; Cormode, David P.; Jarzyna, Peter A.; Delshad, Amanda; Blachford, Courtney; Barazza, Alessandra; Fisher, Edward A.; Gordon, Ronald E.; Fayad, Zahi A.; Mulder, Willem J. M.

    2011-01-01

    Lipoproteins are a family of plasma nanoparticles responsible for the transportation of lipids throughout the body. High-density lipoprotein (HDL), the smallest of the lipoprotein family, measures 7-13 nm in diameter and consists of a cholesteryl ester and triglyceride core that is covered with a

  5. 21 CFR 866.5590 - Lipoprotein X immunolog-ical test system.

    Science.gov (United States)

    2010-04-01

    ... device that consists of the reagents used to measure by immunochemical techniques lipoprotein X (a high-density lipoprotein) in serum and other body fluids. Measurement of lipoprotein X aids in the diagnosis of obstructive liver disease. (b) Classification. Class I (general controls). The device is exempt from the...

  6. Isoflavones enhance interleukin-17 gene expression via retinoic acid receptor-related orphan receptors α and γ

    Science.gov (United States)

    Kojima, Hiroyuki; Takeda, Yukimasa; Muromoto, Ryuta; Takahashi, Miki; Hirao, Toru; Takeuchi, Shinji; Jetten, Anton M.; Matsuda, Tadashi

    2018-01-01

    The retinoic acid receptor-related orphan receptors α and γ (RORα and RORγ), are key regulators of helper T (Th)17 cell differentiation, which is involved in the innate immune system and autoimmune disorders. In this study, we investigated the effects of isoflavones on RORα/γ activity and the gene expression of interleukin (IL)-17, which mediates the function of Th17 cells. In doxycycline-inducible CHO stable cell lines, we found that four isoflavones, biochanin A (BA), genistein, formononetin, and daidzein, enhanced RORα- or RORγ-mediated transcriptional activity in a dose-dependent manner. In an activation assay of the Il17a promoter using Jurkat cells, these compounds enhanced the RORα- or RORγ-mediated activation of the Il17a promoter at concentrations of 1 × 10−6 M to 1 × 10−5 M. In mammalian two-hybrid assays, the four isoflavones enhanced the interaction between the RORα- or RORγ-ligand binding domain and the co-activator LXXLL peptide in a dose-dependent manner. In addition, these isoflavones potently enhanced Il17a mRNA expression in mouse T lymphoma EL4 cells treated with phorbol myristate acetate and ionomycin, but showed slight enhancement of Il17a gene expression in RORα/γ-knockdown EL4 cells. Immunoprecipitation and immunoblotting assays also revealed that BA enhanced the interaction between RORγt and SRC-1, which is a co-activator for nuclear receptors. Taken together, these results suggest that the isoflavones have the ability to enhance IL-17 gene expression by stabilizing the interactions between RORα/γ and co-activators. This also provides the first evidence that dietary chemicals can enhance IL-17 gene expression in immune cells. PMID:25583575

  7. Native High Density Lipoproteins (HDL Interfere with Platelet Activation Induced by Oxidized Low Density Lipoproteins (OxLDL

    Directory of Open Access Journals (Sweden)

    Ivo Volf

    2013-05-01

    Full Text Available Platelets and lipoproteins play a crucial role in atherogenesis, in part by their ability to modulate inflammation and oxidative stress. While oxidized low density lipoproteins (OxLDL play a central role in the development of this disease, high density lipoproteins (HDL represent an atheroprotective factor of utmost importance. As platelet function is remarkably sensitive to the influence of plasma lipoproteins, it was the aim of this study to clarify if HDL are able to counteract the stimulating effects of OxLDL with special emphasis on aspects of platelet function that are relevant to inflammation. Therefore, HDL were tested for their ability to interfere with pro-thrombotic and pro-inflammatory aspects of platelet function. We are able to show that HDL significantly impaired OxLDL-induced platelet aggregation and adhesion. In gel-filtered platelets, HDL decreased both the formation of reactive oxygen species and CD40L expression. Furthermore, HDL strongly interfered with OxLDL-induced formation of platelet-neutrophil aggregates in whole blood, suggesting that platelets represent a relevant and sensitive target for HDL. The finding that HDL effectively competed with the binding of OxLDL to the platelet surface might contribute to their atheroprotective and antithrombotic properties.

  8. Effect of apolipoprotein M on high density lipoprotein metabolism and atherosclerosis in low density lipoprotein receptor knock-out mice

    DEFF Research Database (Denmark)

    Christoffersen, Christina; Jauhiainen, Matti; Moser, Markus

    2008-01-01

    To investigate the role of apoM in high density lipoprotein (HDL) metabolism and atherogenesis, we generated human apoM transgenic (apoM-Tg) and apoM-deficient (apoM(-/-)) mice. Plasma apoM was predominantly associated with 10-12-nm alpha-migrating HDL particles. Human apoM overexpression (11-fol...

  9. Alterations in plasma lipoproteins and apolipoproteins before the age of 40 in heterozygotes for lipoprotein lipase deficiency

    NARCIS (Netherlands)

    Bijvoet, S.; Gagné, S. E.; Moorjani, S.; Gagné, C.; Henderson, H. E.; Fruchart, J. C.; Dallongeville, J.; Alaupovic, P.; Prins, M. [=Martin H.; Kastelein, J. J.; Hayden, M. R.

    1996-01-01

    We have assessed the expression of heterozygosity for lipoprotein lipase (LPL) deficiency by studying a single large French Canadian family comprising 92 persons including 21 carriers of the catalytically defective P207L mutation. Phenotypic changes distinguishing heterozygotes from controls were

  10. Growth factor receptor-binding protein 10 (Grb10) as a partner of phosphatidylinositol 3-kinase in metabolic insulin action.

    Science.gov (United States)

    Deng, Youping; Bhattacharya, Sujoy; Swamy, O Rama; Tandon, Ruchi; Wang, Yong; Janda, Robert; Riedel, Heimo

    2003-10-10

    The regulation of the metabolic insulin response by mouse growth factor receptor-binding protein 10 (Grb10) has been addressed in this report. We find mouse Grb10 to be a critical component of the insulin receptor (IR) signaling complex that provides a functional link between IR and p85 phosphatidylinositol (PI) 3-kinase and regulates PI 3-kinase activity. This regulatory mechanism parallels the established link between IR and p85 via insulin receptor substrate (IRS) proteins. A direct association was demonstrated between Grb10 and p85 but was not observed between Grb10 and IRS proteins. In addition, no effect of mouse Grb10 was observed on the association between IRS-1 and p85, on IRS-1-associated PI 3-kinase activity, or on insulin-mediated activation of IR or IRS proteins. A critical role of mouse Grb10 was observed in the regulation of PI 3-kinase activity and the resulting metabolic insulin response. Dominant-negative Grb10 domains, in particular the SH2 domain, eliminated the metabolic response to insulin in differentiated 3T3-L1 adipocytes. This was consistently observed for glycogen synthesis, glucose and amino acid transport, and lipogenesis. In parallel, the same metabolic responses were substantially elevated by increased levels of Grb10. A similar role of Grb10 was confirmed in mouse L6 cells. In addition to the SH2 domain, the Pro-rich amino-terminal region of Grb10 was implicated in the regulation of PI 3-kinase catalytic activity. These regulatory roles of Grb10 were extended to specific insulin mediators downstream of PI 3-kinase including PKB/Akt, glycogen synthase kinase, and glycogen synthase. In contrast, a regulatory role of Grb10 in parallel insulin response pathways including p70 S6 kinase, ubiquitin ligase Cbl, or mitogen-activated protein kinase p38 was not observed. The dissection of the interaction of mouse Grb10 with p85 and the resulting regulation of PI 3-kinase activity should help elucidate the complexity of the IR signaling

  11. The CXC chemokines gamma interferon (IFN-gamma)-inducible protein 10 and monokine induced by IFN-gamma are released during severe melioidosis

    NARCIS (Netherlands)

    Lauw, F. N.; Simpson, A. J.; Prins, J. M.; van Deventer, S. J.; Chaowagul, W.; White, N. J.; van der Poll, T.

    2000-01-01

    Gamma interferon (IFN-gamma)-inducible protein 10 (IP-10) and monokine induced by IFN-gamma (Mig) are related CXC chemokines which bind to the CXCR3 receptor and specifically target activated T lymphocytes and natural killer (NK) cells. The production of IP-10 and Mig by various cell types in vitro

  12. Comparison of gemfibrozil versus simvastatin in familial combined hyperlipidemia and effects on apolipoprotein-B-containing lipoproteins, low-density lipoprotein subfraction profile, and low-density lipoprotein oxidizability

    NARCIS (Netherlands)

    Bredie, S. J.; de Bruin, T. W.; Demacker, P. N.; Kastelein, J. J.; Stalenhoef, A. F.

    1995-01-01

    We evaluated in a double-blind, placebo-controlled, randomized trial of 45 well-defined patients with familial combined hyperlipidemia, the effect of gemfibrozil (1,200 mg/day) or simvastatin (20 mg/day) on apolipoprotein-B (apo-B)-containing lipoproteins, low-density lipoprotein (LDL) subfraction

  13. Ultracentrifugal and electrophoretic characteristics of the plasma lipoproteins of miniature schnauzer dogs with idiopathic hyperlipoproteinemia.

    Science.gov (United States)

    Whitney, M S; Boon, G D; Rebar, A H; Story, J A; Bottoms, G D

    1993-01-01

    To better characterize the idiopathic hyperlipoproteinemia of Miniature Schnauzer dogs, the plasma lipoproteins of 20 Miniature Schnauzers (MS) and 11 dogs of other breeds (DOB) were evaluated by ultracentrifugation, electrophoresis, and biochemical tests. Seventeen MS were healthy; 3 had diabetes mellitus. Plasma from 6 of 17 healthy and all 3 diabetic MS was visibly lipemic. Lipemia was slight to marked in healthy lipemic MS, and marked in diabetic ones. All DOB had clear plasma; 8 were healthy and 3 had diabetes. All healthy lipemic MS and diabetic lipemic MS had hypertriglyceridemia associated with excess very low density lipoproteins. Chylomicronemia was present in 4 of 6 healthy lipemic MS and all 3 diabetic lipemic MS. Lipoproteins with ultracentrifugal and electrophoretic characteristics of normal low density lipoprotein were lacking in 4 of 6 healthy lipemic MS. The lipoprotein patterns of 4 of 11 healthy nonlipemic MS were characterized by mild hypertriglyceridemia associated with increased very low density lipoproteins and a lack of lipoproteins with characteristics of normal low density lipoproteins. Lipoprotein patterns of diabetic DOB closely resembled those of healthy DOB; those of diabetic lipemic MS resembled those of markedly lipemic healthy lipemic MS. In conclusion, the hyperlipoproteinemia of Miniature Schnauzers is characterized by increased very low density lipoproteins with or without accompanying chylomicronemia; some affected dogs may have decreased low density lipoproteins.

  14. Sorting of bacterial lipoproteins to the outer membrane by the Lol system.

    Science.gov (United States)

    Narita, Shin-ichiro; Tokuda, Hajime

    2010-01-01

    Bacterial lipoproteins comprise a subset of membrane proteins with a lipid-modified cysteine residue at their amino termini through which they are anchored to the membrane. In Gram-negative bacteria, lipoproteins are localized on either the inner or the outer membrane. The Lol system is responsible for the transport of lipoproteins to the outer membrane.The Lol system comprises an inner-membrane ABC transporter LolCDE complex, a periplasmic carrier protein, LolA, and an outer membrane receptor protein, LolB. Lipoproteins are synthesized as precursors in the cytosol and then translocated across the inner membrane by the Sec translocon to the outer leaflet of the inner membrane, where lipoprotein precursors are processed to mature lipoproteins. The LolCDE complex then mediates the release of outer membrane-specific lipoproteins from the inner membrane while the inner membrane-specific lipoproteins possessing Asp at position 2 are not released by LolCDE because it functions as a LolCDE avoidance signal, causing the retention of these lipoproteins in the inner membrane. A water-soluble lipoprotein-LolA complex is formed as a result of the release reaction mediated by LolCDE. This complex traverses the hydrophilic periplasm to reach the outer membrane, where LolB accepts a lipoprotein from LolA and then catalyzes its incorporation into the inner leaflet of the outer membrane.

  15. Interaction between retinoid acid receptor-related orphan receptor alpha (RORA and neuropeptide S receptor 1 (NPSR1 in asthma.

    Directory of Open Access Journals (Sweden)

    Nathalie Acevedo

    Full Text Available Retinoid acid receptor-related Orphan Receptor Alpha (RORA was recently identified as a susceptibility gene for asthma in a genome-wide association study. To investigate the impact of RORA on asthma susceptibility, we performed a genetic association study between RORA single nucleotide polymorphisms (SNPs in the vicinity of the asthma-associated SNP (rs11071559 and asthma-related traits. Because the regulatory region of a previously implicated asthma susceptibility gene, Neuropeptide S receptor 1 (NPSR1, has predicted elements for RORA binding, we hypothesized that RORA may interact biologically and genetically with NPSR1. 37 RORA SNPs and eight NPSR1 SNPs were genotyped in the Swedish birth cohort BAMSE (2033 children and the European cross-sectional PARSIFAL study (1120 children. Seven RORA SNPs confined into a 49 kb region were significantly associated with physician-diagnosed childhood asthma. The most significant association with rs7164773 (T/C was driven by the CC genotype in asthma cases (OR = 2.0, 95%CI 1.36-2.93, p = 0.0003 in BAMSE; and 1.61, 1.18-2.19, p = 0.002 in the combined BAMSE-PARSIFAL datasets, respectively, and strikingly, the risk effect was dependent on the Gln344Arg mutation in NPSR1. In cell models, stimulation of NPSR1 activated a pathway including RORA and other circadian clock genes. Over-expression of RORA decreased NPSR1 promoter activity further suggesting a regulatory loop between these genes. In addition, Rora mRNA expression was lower in the lung tissue of Npsr1 deficient mice compared to wildtype littermates during the early hours of the light period. We conclude that RORA SNPs are associated with childhood asthma and show epistasis with NPSR1, and the interaction between RORA and NPSR1 may be of biological relevance. Combinations of common susceptibility alleles and less common functional polymorphisms may modify the joint risk effects on asthma susceptibility.

  16. Isoflavones enhance interleukin-17 gene expression via retinoic acid receptor-related orphan receptors α and γ

    International Nuclear Information System (INIS)

    Kojima, Hiroyuki; Takeda, Yukimasa; Muromoto, Ryuta; Takahashi, Miki; Hirao, Toru; Takeuchi, Shinji; Jetten, Anton M.; Matsuda, Tadashi

    2015-01-01

    Highlights: • Nuclear receptors, RORα and RORγ, are key regulators of Th17 cell differentiation. • Isoflavones have RORα/γ agonistic activities. • Isoflavones enhance the interaction of RORα/γ with co-activator. • These compounds enhance the expression of Il17a mRNA in mouse EL4 cells. • Dietary isoflavones can act as modulators of Il17a expression via RORα/γ. - Abstract: The retinoic acid receptor-related orphan receptors α and γ (RORα and RORγ), are key regulators of helper T (Th)17 cell differentiation, which is involved in the innate immune system and autoimmune disorders. In this study, we investigated the effects of isoflavones on RORα/γ activity and the gene expression of interleukin (IL)-17, which mediates the function of Th17 cells. In doxycycline-inducible CHO stable cell lines, we found that four isoflavones, biochanin A (BA), genistein, formononetin, and daidzein, enhanced RORα- or RORγ-mediated transcriptional activity in a dose-dependent manner. In an activation assay of the Il17a promoter using Jurkat cells, these compounds enhanced the RORα- or RORγ-mediated activation of the Il17a promoter at concentrations of 1 × 10 −6 M to 1 × 10 −5 M. In mammalian two-hybrid assays, the four isoflavones enhanced the interaction between the RORα- or RORγ-ligand binding domain and the co-activator LXXLL peptide in a dose-dependent manner. In addition, these isoflavones potently enhanced Il17a mRNA expression in mouse T lymphoma EL4 cells treated with phorbol myristate acetate and ionomycin, but showed slight enhancement of Il17a gene expression in RORα/γ-knockdown EL4 cells. Immunoprecipitation and immunoblotting assays also revealed that BA enhanced the interaction between RORγt and SRC-1, which is a co-activator for nuclear receptors. Taken together, these results suggest that the isoflavones have the ability to enhance IL-17 gene expression by stabilizing the interactions between RORα/γ and co-activators. This also

  17. Limitations of Using IL-17A and IFN-γ-Induced Protein 10 to Detect Bovine Tuberculosis

    Science.gov (United States)

    Xin, Ting; Gao, Xintao; Yang, Hongjun; Li, Pingjun; Liang, Qianqian; Hou, Shaohua; Sui, Xiukun; Guo, Xiaoyu; Yuan, Weifeng; Zhu, Hongfei; Ding, Jiabo; Jia, Hong

    2018-01-01

    Bovine tuberculosis (bTB) is primarily caused by infection with Mycobacterium bovis, which belongs to the Mycobacterium tuberculosis complex. The airborne route is considered the most common for transmission of M. bovis, and more than 15% of cattle with bTB shed the Mycobacterium, which can be detect by nested PCR to amplify mycobacterial mpb70 from a nasal swab from a cow. To screen for cytokines fostering early and accurate detection of bTB, peripheral blood mononuclear cells were isolated from naturally M. bovis-infected, experimentally M. bovis 68002-infected, and uninfected cattle, then these cells were stimulated by PPD-B, CFP-10-ESAT-6 (CE), or phosphate-buffered saline (PBS) for 6 h. The levels of interferon gamma (IFN-γ), IFN-γ-induced protein 10 (IP-10), IL-6, IL-12, IL-17A, and tumor necrosis factor alpha mRNA were measured using real-time PCR. To explore the cytokines associated with different periods of M. bovis infection, cattle were divided into three groups: PCR-positive, PCR-negative, and uninfected using the tuberculin skin test, CFP-10/ESAT-6/TB10.4 protein cocktail-based skin test, IFN-γ release assay (IGRA), CFP-10/ESAT-6 (CE)-based IGRA, and nested PCR. The expression of IP-10, IL-17A, and IFN-γ proteins induced by PPD-B, CE, or PBS was detected by ELISA. The results showed that levels of PPD-B-stimulated IL-17A and IP-10 (mRNA and protein), and CE-induced IP-10 (mRNA and protein) were significantly higher in cattle naturally or experimentally infected with M. bovis than in those that were uninfected. The levels of PPD-B- or CE-induced IL-17A and IP-10 (protein) could be used to differentiate M. bovis-infected calves from uninfected ones for 6 to 30 weeks post-infection, whereas PPD-B- and CE-induced IP-10 and IL-17A mRNA expression could be used to differentiate M. bovis-infected calves from uninfected ones between 6 and 58 weeks post-infection. However, CE-induced IL-17A (protein) was not a reliable indicator of M. bovis infection

  18. High-Density Lipoproteins and the Immune System

    Directory of Open Access Journals (Sweden)

    Hidesuke Kaji

    2013-01-01

    Full Text Available High-density lipoprotein (HDL plays a major role in vasodilation and in the reduction of low-density lipoprotein (LDL oxidation, inflammation, apoptosis, thrombosis, and infection; however, HDL is now less functional in these roles under certain conditions. This paper focuses on HDL, its anti-inflammation behavior, and the mechanisms by which HDL interacts with components of the innate and adaptive immune systems. Genome-wide association studies (GWAS and proteomic studies have elucidated important molecules involved in the interaction between HDL and the immune system. An understanding of these mechanisms is expected to be useful for the prevention and treatment of chronic inflammation due to metabolic syndrome, atherosclerosis, or various autoimmune diseases.

  19. Nonalcoholic Fatty Liver Disease: Focus on Lipoprotein and Lipid Deregulation

    Directory of Open Access Journals (Sweden)

    Klementina Fon Tacer

    2011-01-01

    Full Text Available Obesity with associated comorbidities is currently a worldwide epidemic and among the most challenging health conditions in the 21st century. A major metabolic consequence of obesity is insulin resistance which underlies the pathogenesis of the metabolic syndrome. Nonalcoholic fatty liver disease (NAFLD is the hepatic manifestation of obesity and metabolic syndrome. It comprises a disease spectrum ranging from simple steatosis (fatty liver, through nonalcoholic steatohepatitis (NASH to fibrosis, and ultimately liver cirrhosis. Abnormality in lipid and lipoprotein metabolism accompanied by chronic inflammation is the central pathway for the development of metabolic syndrome-related diseases, such as atherosclerosis, cardiovascular disease (CVD, and NAFLD. This paper focuses on pathogenic aspect of lipid and lipoprotein metabolism in NAFLD and the relevant mouse models of this complex multifactorial disease.

  20. Interrelationships between postprandial lipoprotein B:CIII particle changes and high-density lipoprotein subpopulation profiles in mixed hyperlipoproteinemia.

    Science.gov (United States)

    Saïdi, Y; Sich, D; Camproux, A; Egloff, M; Federspiel, M C; Gautier, V; Raisonnier, A; Turpin, G; Beucler, I

    1999-01-01

    We studied the relationships postprandially between triglyceride-rich lipoprotein (TRL) and high-density lipoprotein (HDL) in 11 mixed hyperlipoproteinemia (MHL) and 11 hypercholesterolemia (HCL) patients. The high and prolonged postprandial triglyceridemia response observed in MHL but not HCL patients was essentially dependent on very-low-density lipoprotein (VLDL) changes. This abnormal response was related to decreased lipoprotein lipase (LPL) activity (-48.7%, P<.01) in MHL compared with HCL subjects. Cholesteryl ester transfer protein (CETP) activity was postprandially enhanced only in MHL patients, and this elevation persisted in the late period (+19% at 12 hours, P<.05), sustaining the delayed enrichment of VLDL with cholesteryl ester (CE). The late postprandial period in MHL patients was also characterized by high levels of apolipoprotein B (apoB)-containing lipoproteins with apoCIII ([LpB:CIII] +36% at 12 hours, P<.01) and decreased levels of apoCIII contained in HDL ([LpCIII-HDL] -34% at 12 hours, P<.01), reflecting probably a defective return of apoCIII from TRL toward HDL. In MHL compared with HCL patients, decreased HDL2 levels were related to both HDL2b and HDL2a subpopulations (-57% and -49%, respectively, P<.01 for both) and decreased apoA-I levels (-53%, P<.01) were equally linked to decreased HDL2 with apoA-I only (LpA-I) and HDL2 with both apoA-I and apoA-II ([LpA-I:A-II] -55% and -52%, respectively, P<.01 for both). The significant inverse correlations between the postprandial magnitude of LpB:CIII and HDL2-LpA-I and HDL2b levels in MHL patients underline the close TRL-HDL interrelationships. Our findings indicate that TRL and HDL abnormalities evidenced at fasting were postprandially amplified, tightly interrelated, and persistent during the late fed period in mixed hyperlipidemia. Thus, these fasting abnormalities are likely postprandially originated and may constitute proatherogenic lipoprotein disorders additional to the HCL in MHL patients.

  1. Lipoprotein (a) as a cause of cardiovascular disease

    DEFF Research Database (Denmark)

    Nordestgaard, Børge G; Langsted, Anne

    2016-01-01

    Human epidemiologic and genetic evidence using the Mendelian randomization approach in large-scale studies now strongly supports that elevated lipoprotein (a) [Lp(a)] is a causal risk factor for cardiovascular disease, that is, for myocardial infarction, atherosclerotic stenosis, and aortic valve...... with very high concentrations to reduce cardiovascular disease are awaited. Recent genetic evidence documents elevated Lp(a) as a cause of myocardial infarction, atherosclerotic stenosis, and aortic valve stenosis....

  2. A clustering analysis of lipoprotein diameters in the metabolic syndrome

    Directory of Open Access Journals (Sweden)

    Frazier-Wood Alexis C

    2011-12-01

    Full Text Available Abstract Background The presence of smaller low-density lipoproteins (LDL has been associated with atherosclerosis risk, and the insulin resistance (IR underlying the metabolic syndrome (MetS. In addition, some research has supported the association of very low-, low- and high-density lipoprotein (VLDL HDL particle diameters with components of the metabolic syndrome (MetS, although this has been the focus of less research. We aimed to explore the relationship of VLDL, LDL and HDL diameters to MetS and its features, and by clustering individuals by their diameters of VLDL, LDL and HDL particles, to capture information across all three fractions of lipoprotein into a unified phenotype. Methods We used nuclear magnetic resonance spectroscopy measurements on fasting plasma samples from a general population sample of 1,036 adults (mean ± SD, 48.8 ± 16.2 y of age. Using latent class analysis, the sample was grouped by the diameter of their fasting lipoproteins, and mixed effects models tested whether the distribution of MetS components varied across the groups. Results Eight discrete groups were identified. Two groups (N = 251 were enriched with individuals meeting criteria for the MetS, and were characterized by the smallest LDL/HDL diameters. One of those two groups, one was additionally distinguished by large VLDL, and had significantly higher blood pressure, fasting glucose, triglycerides, and waist circumference (WC; P Conclusions While small LDL diameters remain associated with IR and the MetS, the occurrence of these in conjunction with a shift to overall larger VLDL diameter may identify those with the highest fasting glucose, TG and WC within the MetS. If replicated, the association of this phenotype with more severe IR-features indicated that it may contribute to identifying of those most at risk for incident type II diabetes and cardiometabolic disease.

  3. Lipid and lipoprotein abnormalities in acute lymphoblastic leukemia survivors.

    Science.gov (United States)

    Morel, Sophia; Leahy, Jade; Fournier, Maryse; Lamarche, Benoit; Garofalo, Carole; Grimard, Guy; Poulain, Floriane; Delvin, Edgard; Laverdière, Caroline; Krajinovic, Maja; Drouin, Simon; Sinnett, Daniel; Marcil, Valérie; Levy, Emile

    2017-05-01

    Survivors of acute lymphoblastic leukemia (ALL), the most common cancer in children, are at increased risk of developing late cardiometabolic conditions. However, the mechanisms are not fully understood. This study aimed to characterize the plasma lipid profile, Apo distribution, and lipoprotein composition of 80 childhood ALL survivors compared with 22 healthy controls. Our results show that, despite their young age, 50% of the ALL survivors displayed dyslipidemia, characterized by increased plasma triglyceride (TG) and LDL-cholesterol, as well as decreased HDL-cholesterol. ALL survivors exhibited lower plasma Apo A-I and higher Apo B-100 and C-II levels, along with elevated Apo C-II/C-III and B-100/A-I ratios. VLDL fractions of dyslipidemic ALL survivors contained more TG, free cholesterol, and phospholipid moieties, but less protein. Differences in Apo content were found between ALL survivors and controls for all lipoprotein fractions except HDL 3 HDL 2 , especially, showed reduced Apo A-I and raised Apo A-II, leading to a depressed Apo A-I/A-II ratio. Analysis of VLDL-Apo Cs disclosed a trend for higher Apo C-III 1 content in dyslipidemic ALL survivors. In conclusion, this thorough investigation demonstrates a high prevalence of dyslipidemia in ALL survivors, while highlighting significant abnormalities in their plasma lipid profile and lipoprotein composition. Special attention must, therefore, be paid to these subjects given the atherosclerotic potency of lipid and lipoprotein disorders. Copyright © 2017 by the American Society for Biochemistry and Molecular Biology, Inc.

  4. Lipoprotein Nanoplatform for Targeted Delivery of Diagnostic and Therapeutic Agents

    Directory of Open Access Journals (Sweden)

    Jerry D. Glickson

    2008-03-01

    Full Text Available Low-density lipoprotein (LDL provides a highly versatile natural nanoplatform for delivery of visible or near-infrared fluorescent optical and magnetic resonance imaging (MRI contrast agents and photodynamic therapy and chemotherapeutic agents to normal and neoplastic cells that overexpress low-density lipoprotein receptors (LDLRs. Extension to other lipoproteins ranging in diameter from about 10 nm (high-density lipoprotein [HDL] to over a micron (chylomicrons is feasible. Loading of contrast or therapeutic agents onto or into these particles has been achieved by protein loading (covalent attachment to protein side chains, surface loading (intercalation into the phospholipid monolayer, and core loading (extraction and reconstitution of the triglyceride/cholesterol ester core. Core and surface loading of LDL have been used for delivery of optical imaging agents to tumor cells in vivo and in culture. Surface loading was used for delivery of gadolinium-bis-stearylamide contrast agents for in vivo MRI detection in tumor-bearing mice. Chlorin and phthalocyanine near-infrared photodynamic therapy agents (≤ 400/LDL have been attached by core loading. Protein loading was used to reroute the LDL from its natural receptor (LDLR to folate receptors and could be used to target other receptors. A semisynthetic nanoparticle has been constructed by coating magnetite iron oxide nanoparticles with carboxylated cholesterol and overlaying a monolayer of phospholipid to which apolipoprotein A1 or E was adsorbed for targeting HDL or adsorbing synthetic amphipathic helical peptides ltargeting LDL or folate receptors. These particles can be used for in situ loading of magnetite into cells for MRI-monitored cell tracking or gene expression.

  5. Pharmacologic management of isolated low high-density lipoprotein syndrome.

    Science.gov (United States)

    Bermúdez, Valmore; Cano, Raquel; Cano, Clímaco; Bermúdez, Fernando; Arraiz, Nailet; Acosta, Luis; Finol, Freddy; Pabón, María Rebeca; Amell, Anilsa; Reyna, Nadia; Hidalgo, Joaquin; Kendall, Paúl; Manuel, Velasco; Hernández, Rafael

    2008-01-01

    High-density lipoprotein (HDL) cholesterol is a heterogeneous group of lipoproteins exhibiting a variety of properties like prostacyclin production stimulation, decrease in platelet aggregation, endothelial cell apoptosis inhibition, and low-density lipoprotein oxidation blockade. Epidemiologic studies have shown an inverse relation between HDL cholesterol levels and cardiovascular risk. Low HDL cholesterol is associated with increased risk for myocardial infarction, stroke, sudden death, peripheral artery disease, and postangioplasty restenosis. In contrast, high HDL levels are associated with longevity and protection against atherosclerotic disease development. Given the evolving epidemic of obesity, diabetes mellitus, and metabolic syndrome, the prevalence of low HDL will continue to rise. In the United States, low HDL is present in 35% of men, 15% of women, and approximately 63% of patients with coronary artery disease. Data extracted from the Framingham study highlight that 1-mg increase in HDL levels decreases by 2% to 3% the risk of cardiovascular disease. There is no doubt regarding clinical importance about isolated low HDL, but relatively few clinicians consider a direct therapeutic intervention of this dyslipidemia. In this sense, lifestyle measures should be the first-line strategy to manage low HDL levels. On the other hand, pharmacologic options include niacin, fibrates, and statins. Fibrates appear to reduce risk preferentially in patients with low HDL with metabolic syndrome, whereas statins reduce risk across all levels of HDL. Torcetrapib, a cholesteryl esters transfer protein inhibitor, represented a hope to raise this lipoprotein; however, all clinical trials on this drug had ceased after ILLUMINATE, RADIANCE and ERASE trials had recorded an increase in mortality, rates of myocardial infarction, angina, and heart failure. In the near future, drugs as beta-glucans, Apo-A1 mimetic peptides, and ACAT inhibitors, are the new promises to treat this

  6. Apolipoprotein (A) Isoform Distribution and Plasma Lipoprotein (a ...

    African Journals Online (AJOL)

    Plasma lipoprotein (a) Concentrations and apo(a) isoforms were determined in 101 healthy Nigerian subjects (M=63), F=38; age range 17-68 years), and coronary heart disease (CHD) patients (M=19, F=17, age range 30-79 years). Median Lp(a) level was 24.4 mg/di in the CHD patients and 22.1 mg/di in the controls.

  7. Correlation studies between serum concentrations of zinc and lipoproteins

    International Nuclear Information System (INIS)

    Saiki, Mitiko; Alves, Edson R.; Vasconcellos, M.B.A.; Sumita, Nairo M.; Jaluul, Omar; Jacob-Filho, Wilson

    2009-01-01

    In this study, serum zinc and lipoprotein concentrations were determined in order to assess the health status of an elderly population residing in Sao Paulo city, SP, Brazil. This population consisted of elderly considered healthy and participating of a 'Successful Ageing' program of the Sao Paulo University Medical School. Fasting blood samples were collected from 87 elderly individuals (63 females and 24 males) aged 60-91 and mean age of 72 +- 7 years. Zn concentrations were determined by neutron activation analysis at the IPEN/CNEN/ SP and, the lipoprotein (HDL, LDL and total cholesterol) concentrations were determined using routine analysis methods of the Central Laboratory Division, Hospital das Clinicas, FMUSP. Results obtained for Zn indicated that all the individuals presented this element within the recommended value. For total cholesterol and HDL-cholesterol concentrations, 96 % of elderly presented levels within the desired range but for LDL cholesterol concentrations only about 70.0 % of individuals were in the desired range. Serum concentration of Zn were positively correlated to LDL-cholesterol levels (correlation coefficient r = 0.21, p < 0.06). Furthermore, the ratios of [HDL-cholesterol] / [LDL-cholesterol] were negatively correlated with Zn concentrations (r = - 0.234, p < 0.04). The positive correlation found between the serum concentrations of Zn and LDL-cholesterol indicates the possible effect of this element in serum lipoprotein profiles. Thus ,these findings suggest that more investigations should be conducted on Zn supplementation in elderly subjects with cardiovascular diseases. (author)

  8. Central nervous system regulation of intestinal lipid and lipoprotein metabolism.

    Science.gov (United States)

    Farr, Sarah; Taher, Jennifer; Adeli, Khosrow

    2016-02-01

    In response to nutrient availability, the small intestine and brain closely communicate to modulate energy homeostasis and metabolism. The gut-brain axis involves complex nutrient sensing mechanisms and an integration of neuronal and hormonal signaling. This review summarizes recent evidence implicating the gut-brain axis in regulating lipoprotein metabolism, with potential implications for the dyslipidemia of insulin resistant states. The intestine and brain possess distinct mechanisms for sensing lipid availability, which triggers subsequent regulation of feeding, glucose homeostasis, and adipose tissue metabolism. More recently, central receptors, neuropeptides, and gut hormones that communicate with the brain have been shown to modulate hepatic and intestinal lipoprotein metabolism via parasympathetic and sympathetic signaling. Gut-derived glucagon-like peptides appear to be particularly important in modulating the intestinal secretion of chylomicron particles via a novel brain-gut axis. Dysregulation of these pathways may contribute to postprandial diabetic dyslipidemia. Emerging evidence implicates the central and enteric nervous systems in controlling many aspects of lipid and lipoprotein metabolism. Bidirectional communication between the gut and brain involving neuronal pathways and gut peptides is critical for regulating feeding and metabolism, and forms a neuroendocrine circuit to modulate dietary fat absorption and intestinal production of atherogenic chylomicron particles.

  9. Lipoprotein(a Serum Levels in Diabetic Patients with Retinopathy

    Directory of Open Access Journals (Sweden)

    Giulia Malaguarnera

    2013-01-01

    Full Text Available Background. Atherogenic lipoproteins, such as total cholesterol, LDL cholesterol, oxidized low density lipoprotein, and triglycerides, are associated with progression of retinopathy. Aim. To evaluate the relationship between lipoprotein(a and retinopathy in patients with type 2 diabetes mellitus. Materials and Methods. We enrolled 145 diabetic consecutive patients (82 females, 63 males; mean age 66.8±12 years, mean duration of diabetes 9.4±6.8 years. Presence and severity of retinopathy were evaluated. Serum lipid profile, including Lp(a level, was assessed. Results. High Lp(a levels have been observed in 54 (78.3% subjects and normal levels in 13 (18.85% subjects as regards diabetic patients with retinopathy. Lp(a levels were high in 15 subjects (21.75% and normal in 63 subjects (91.35% as regards patients without retinopathy. Conclusions. Lp(a levels are increased in a significant percentage of patients with retinopathy compared to diabetic patients without retinopathy. The impact of Lp(a levels on diabetic retinopathy needs to be further investigated.

  10. Assessment of permeation of lipoproteins in human carotid tissue

    Science.gov (United States)

    Ghosn, Mohamad G.; Syed, Saba H.; Leba, Michael; Morrisett, Joel D.; Tuchin, Valery V.; Larin, Kirill V.

    2010-02-01

    Cardiovascular disease is among the leading causes of death in the United States. Specifically, atherosclerosis is an increasingly devastating contributor to the tally and has been found to be a byproduct of arterial permeability irregularities in regards to lipoprotein penetration. To further explore arterial physiology and molecular transport, the imaging technique of Optical Coherence Tomography (OCT) was employed. With OCT, the permeation of glucose (MW = 180 Da), low density lipoprotein (LDL; MW = 2.1 × 106 Da), and high density lipoprotein (HDL; MW = 2.5 × 105 Da) in human carotid tissue was studied to determine the effect of different molecular characteristics on permeation in atherosclerotic tissues. The permeability rates calculated from the diffusion of the molecular agents into the abnormal carotid tissue samples is compared to those of normal, healthy tissue. The results show that in the abnormal tissue, the permeation of agents correlate to the size constraints. The larger molecules of LDL diffuse the slowest, while the smallest molecules of glucose diffuse the fastest. However, in normal tissue, LDL permeates at a faster rate than the other two agents, implying the existence of a transport mechanism that facilitates the passage of LDL molecules. These results highlight the capability of OCT as a sensitive and specific imaging technique as well as provide significant information to the understanding of atherosclerosis and its effect on tissue properties.

  11. Acrolein consumption induces systemic dyslipidemia and lipoprotein modification

    International Nuclear Information System (INIS)

    Conklin, Daniel J.; Barski, Oleg A.; Lesgards, Jean-Francois; Juvan, Peter; Rezen, Tadeja; Rozman, Damjana; Prough, Russell A.; Vladykovskaya, Elena; Liu, SiQi; Srivastava, Sanjay; Bhatnagar, Aruni

    2010-01-01

    Aldehydes such as acrolein are ubiquitous pollutants present in automobile exhaust, cigarette, wood, and coal smoke. Such aldehydes are also constituents of several food substances and are present in drinking water, irrigation canals, and effluents from manufacturing plants. Oral intake represents the most significant source of exposure to acrolein and related aldehydes. To study the effects of short-term oral exposure to acrolein on lipoprotein levels and metabolism, adult mice were gavage-fed 0.1 to 5 mg acrolein/kg bwt and changes in plasma lipoproteins were assessed. Changes in hepatic gene expression related to lipid metabolism and cytokines were examined by qRT-PCR analysis. Acrolein feeding did not affect body weight, blood urea nitrogen, plasma creatinine, electrolytes, cytokines or liver enzymes, but increased plasma cholesterol and triglycerides. Similar results were obtained with apoE-null mice. Plasma lipoproteins from acrolein-fed mice showed altered electrophoretic mobility on agarose gels. Chromatographic analysis revealed elevated VLDL cholesterol, phospholipids, and triglycerides levels with little change in LDL or HDL. NMR analysis indicated shifts from small to large VLDL and from large to medium-small LDL with no change in the size of HDL particles. Increased plasma VLDL was associated with a significant decrease in post-heparin plasma hepatic lipase activity and a decrease in hepatic expression of hepatic lipase. These observations suggest that oral exposure to acrolein could induce or exacerbate systemic dyslipidemia and thereby contribute to cardiovascular disease risk.

  12. Acrolein consumption induces systemic dyslipidemia and lipoprotein modification

    Energy Technology Data Exchange (ETDEWEB)

    Conklin, Daniel J., E-mail: dj.conklin@louisville.ed [Diabetes and Obesity Center, University of Louisville, Louisville, KY 40202 (United States); Barski, Oleg A; Lesgards, Jean-Francois [Diabetes and Obesity Center, University of Louisville, Louisville, KY 40202 (United States); Juvan, Peter; Rezen, Tadeja; Rozman, Damjana [Centre for Functional Genomics and Bio-Chips (CFGBC), Institute of Biochemistry, Faculty of Medicine, University of Ljubljana, Zaloska 4, SI-1000 Ljubljana (Slovenia); Prough, Russell A [Department of Biochemistry and Molecular Biology, University of Louisville, Louisville, KY 40202 (United States); Vladykovskaya, Elena; Liu, SiQi; Srivastava, Sanjay [Diabetes and Obesity Center, University of Louisville, Louisville, KY 40202 (United States); Bhatnagar, Aruni [Diabetes and Obesity Center, University of Louisville, Louisville, KY 40202 (United States); Department of Biochemistry and Molecular Biology, University of Louisville, Louisville, KY 40202 (United States)

    2010-02-15

    Aldehydes such as acrolein are ubiquitous pollutants present in automobile exhaust, cigarette, wood, and coal smoke. Such aldehydes are also constituents of several food substances and are present in drinking water, irrigation canals, and effluents from manufacturing plants. Oral intake represents the most significant source of exposure to acrolein and related aldehydes. To study the effects of short-term oral exposure to acrolein on lipoprotein levels and metabolism, adult mice were gavage-fed 0.1 to 5 mg acrolein/kg bwt and changes in plasma lipoproteins were assessed. Changes in hepatic gene expression related to lipid metabolism and cytokines were examined by qRT-PCR analysis. Acrolein feeding did not affect body weight, blood urea nitrogen, plasma creatinine, electrolytes, cytokines or liver enzymes, but increased plasma cholesterol and triglycerides. Similar results were obtained with apoE-null mice. Plasma lipoproteins from acrolein-fed mice showed altered electrophoretic mobility on agarose gels. Chromatographic analysis revealed elevated VLDL cholesterol, phospholipids, and triglycerides levels with little change in LDL or HDL. NMR analysis indicated shifts from small to large VLDL and from large to medium-small LDL with no change in the size of HDL particles. Increased plasma VLDL was associated with a significant decrease in post-heparin plasma hepatic lipase activity and a decrease in hepatic expression of hepatic lipase. These observations suggest that oral exposure to acrolein could induce or exacerbate systemic dyslipidemia and thereby contribute to cardiovascular disease risk.

  13. Triglyceride-rich lipoproteins and high-density lipoprotein cholesterol in patients at high risk of cardiovascular disease: evidence and guidance for management

    NARCIS (Netherlands)

    Chapman, M. John; Ginsberg, Henry N.; Amarenco, Pierre; Andreotti, Felicita; Borén, Jan; Catapano, Alberico L.; Descamps, Olivier S.; Fisher, Edward; Kovanen, Petri T.; Kuivenhoven, Jan Albert; Lesnik, Philippe; Masana, Luis; Nordestgaard, Børge G.; Ray, Kausik K.; Reiner, Zeljko; Taskinen, Marja-Riitta; Tokgözoglu, Lale; Tybjærg-Hansen, Anne; Watts, Gerald F.

    2011-01-01

    Even at low-density lipoprotein cholesterol (LDL-C) goal, patients with cardiometabolic abnormalities remain at high risk of cardiovascular events. This paper aims (i) to critically appraise evidence for elevated levels of triglyceride-rich lipoproteins (TRLs) and low levels of high-density

  14. Effects of gemfibrozil or simvastatin on apolipoprotein-B-containing lipoproteins, apolipoprotein-CIII and lipoprotein(a) in familial combined hyperlipidaemia

    NARCIS (Netherlands)

    Bredie, S. J.; Westerveld, H. T.; Knipscheer, H. C.; de Bruin, T. W.; Kastelein, J. J.; Stalenhoef, A. F.

    1996-01-01

    Familial combined hyperlipidaemia (FCH), characterized by elevated very-low-density lipoprotein (VLDL) and/or low-density lipoprotein (LDL), is associated with an increased prevalence of premature cardiovascular disease. Therefore, lipid-lowering is frequently indicated. We evaluated in a parallel,

  15. Triglyceride-rich lipoproteins and high-density lipoprotein cholesterol in patients at high risk of cardiovascular disease: evidence and guidance for management

    DEFF Research Database (Denmark)

    Chapman, M John; Ginsberg, Henry N; Amarenco, Pierre

    2011-01-01

    Even at low-density lipoprotein cholesterol (LDL-C) goal, patients with cardiometabolic abnormalities remain at high risk of cardiovascular events. This paper aims (i) to critically appraise evidence for elevated levels of triglyceride-rich lipoproteins (TRLs) and low levels of high-density lipop...

  16. Plasma Cholesteryl Ester Transfer, But Not Cholesterol Esterification, Is Related to Lipoprotein-Associated Phospholipase A(2) : Possible Contribution to an Atherogenic Lipoprotein Profile

    NARCIS (Netherlands)

    Dullaart, Robin P. F.; Constantinides, Alexander; Perton, Frank G.; van Leeuwen, Jeroen J. J.; van Pelt, Joost L.; de Vries, Rindert; van Tol, Arie

    Context: Plasma lipoprotein-associated phospholipase A(2) (Lp-PLA(2)) predicts incident cardiovascular disease and is associated preferentially with negatively charged apolipoprotein B-containing lipoproteins. The plasma cholesteryl ester transfer (CET) process, which contributes to low high-density

  17. Sorting of an integral outer membrane protein via the lipoprotein-specific Lol pathway and a dedicated lipoprotein pilotin.

    Science.gov (United States)

    Collin, Séverine; Guilvout, Ingrid; Nickerson, Nicholas N; Pugsley, Anthony P

    2011-05-01

    The lipoprotein PulS is a dedicated chaperone that is required to target the secretin PulD to the outer membrane in Klebsiella or Escherichia coli, and to protect it from proteolysis. Here, we present indirect evidence that PulD protomers do not assemble into the secretin dodecamer before they reach the outer membrane, and that PulS reaches the outer membrane in a soluble heterodimer with the general lipoprotein chaperone LolA. However, we could not find any direct evidence for PulD protomer association with the PulS-LolA heterodimer. Instead, in cells producing PulD and a permanently locked PulS-LolA dimer (in which LolA carries an R43L substitution that prevents lipoprotein transfer to LolB in the outer membrane), LolAR43L was found in the inner membrane, probably still associated with PulS bound to PulD that had been incorrectly targeted because of the LolAR43L substitution. It is speculated that PulD protomers normally cross the periplasm together with PulS bound to LolA but when the latter cannot be separated (due to the mutation in lolA), the PulD protomers form dodecamers that insert into the inner membrane. © 2011 Blackwell Publishing Ltd.

  18. Triglyceride content in remnant lipoproteins is significantly increased after food intake and is associated with plasma lipoprotein lipase.

    Science.gov (United States)

    Nakajima, Katsuyuki; Tokita, Yoshiharu; Sakamaki, Koji; Shimomura, Younosuke; Kobayashi, Junji; Kamachi, Keiko; Tanaka, Akira; Stanhope, Kimber L; Havel, Peter J; Wang, Tao; Machida, Tetsuo; Murakami, Masami

    2017-02-01

    Previous large population studies reported that non-fasting plasma triglyceride (TG) reflect a higher risk for cardiovascular disease than TG in the fasting plasma. This is suggestive of the presence of higher concentration of remnant lipoproteins (RLP) in postprandial plasma. TG and RLP-TG together with other lipids, lipoproteins and lipoprotein lipase (LPL) in both fasting and postprandial plasma were determined in generally healthy volunteers and in patients with coronary artery disease (CAD) after consuming a fat load or a more typical moderate meal. RLP-TG/TG ratio (concentration) and RLP-TG/RLP-C ratio (particle size) were significantly increased in the postprandial plasma of both healthy controls and CAD patients compared with those in fasting plasma. LPL/RLP-TG ratio demonstrated the interaction correlation between RLP concentration and LPL activity The increased RLP-TG after fat consumption contributed to approximately 90% of the increased plasma TG, while approximately 60% after a typical meal. Plasma LPL in postprandial plasma was not significantly altered after either type of meal. Concentrations of RLP-TG found in the TG along with its particle size are significantly increased in postprandial plasma compared with fasting plasma. Therefore, non-fasting TG determination better reflects the presence of higher RLP concentrations in plasma. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  19. Androgen and FSH synergistically stimulate lipoprotein degradation and utilization by ovary granulosa cells

    International Nuclear Information System (INIS)

    Schreiber, J.R.; Nakamura, K.; Schmit, V.; Weinstein, D.B.

    1984-01-01

    Androgen can directly modulate the induction of steroidogenic enzymes by FSH (follicle stimulating hormone) in ovary granulosa cells. In studies of its mechanism of action, the authors examined the androgen effect on granulosa cell interaction with lipoproteins, the physiologic source of cholesterol. After granulosa cells were cultured for 48 hours with and without androgen and/or FSH, the cells were incubated for 24 hours with 125 I-lipoproteins [human high density lipoprotein (HDL), rat HDL, or human low density lipoprotein (LDL)]. The media were then analyzed for lipoprotein protein coat degradation products (mainly 125 I-monoiodotyrosine) and progestin [mainly 20 alpha-dihydroprogesterone (20 alpha-DHP)]. In the absence of FSH and androgen, 2 X 10(5) granulosa cells degraded basal levels of all three lipoproteins, but produced no measurable 20 alpha-DHP. The addition of 10(-7) M androstenedione (A), testosterone (T), or 5 alpha-dihydrotestosterone (DHT) had no effect on lipoprotein protein degradation or 20 alpha-DHP production. FSH alone stimulated lipoprotein protein degradation by 50 to 300% while the addition of androgen synergistically augmented the FSH-stimulated 20 alpha-DHP production as well as protein coat degradation of all three lipoproteins. DHT and T were both effective, indicating that androgens themselves, and not estrogen products, were responsible for the effect on lipoprotein protein degradation and 20 alpha-DHP production

  20. Comparison of lipoprotein electrophoresis and apolipoprotein e genotyping in investigating dysbetalipoproteinemia

    International Nuclear Information System (INIS)

    Ahmed, F.; Kadiki, A.E.

    2017-01-01

    Dysbetalipoproteinemia is often associated with apolipoprotein E2E2 homozygosity; however, lipoprotein electrophoresis may also be used to assist in the diagnosis. The aim of this study was to compare apolipoprotein E (apo E) genotyping and lipoprotein electrophoresis in investigating dysbetalipoproteinemia. Data were collected over a three-year period from a lipid clinic in a tertiary referral centre and reviewed for apo E genotyping and lipoprotein electrophoresis. Sixty-two patients had both apo E genotyping and lipoprotein electrophoresis. Of these, 16 patients showed broad beta band on electrophoresis. However, only 3 of them had apo E2E2 homozygosity on genotyping. Lipoprotein electrophoresis and apo E genotyping results showed poor concordance. This was primarily due to visual interpretation error of lipoprotein electrophoresis which may over diagnose dysbetalipoproteinemia. (author)

  1. Comparison of Lipoprotein Electrophoresis and Apolipoprotein E Genotyping in Investigating Dysbetalipoproteinemia.

    Science.gov (United States)

    Ahmed, Farhan; El-Kadiki, Alia; Gibbons, Stephen

    2017-06-01

    Dysbetalipoproteinemia is often associated with apolipoprotein E2E2 homozygosity; however, lipoprotein electrophoresis may also be used to assist in the diagnosis. The aim of this study was to compare apolipoprotein E (apo E) genotyping and lipoprotein electrophoresis in investigating dysbetalipoproteinemia. Data were collected over a three-year period from a lipid clinic in a tertiary referral centre and reviewed for apo E genotyping and lipoprotein electrophoresis. Sixty-two patients had both apo E genotyping and lipoprotein electrophoresis. Of these, 16 patients showed broad beta band on electrophoresis. However, only 3 of them had apo E2E2 homozygosity on genotyping. Lipoprotein electrophoresis and apo E genotyping results showed poor concordance. This was primarily due to visual interpretation error of lipoprotein electrophoresis which may over diagnose dysbetalipoproteinemia.

  2. Recent advances in lipoprotein and atherosclerosis: A nutrigenomic approach

    Directory of Open Access Journals (Sweden)

    López, Sergio

    2009-03-01

    Full Text Available Atherosclerosis is a disease in which multiple factors contribute to the degeneration of the vascular wall. Many risk factors have been identified as having influence on the progression of atherosclerosis among them, the type of diet. Multifactorial interaction among lipoproteins, vascular wall cells, and inflammatory mediators has been recognised as the basis of atherogenesis. Dietary intake affects lipoprotein concentration and composition providing risk or protection at several stages of atherosclerosis. More intriguingly, it has been demonstrated that the extent to which each lipid or lipoprotein is associated with cardiovascular disease depends on the time to last meal; thus, postprandial lipoproteins, main lipoproteins in blood after a high-fat meal, have been shown to strongly influence atherogenesis. As a complex biological process, the full cellular and molecular characterization of atherosclerosis derived by diet, calls for application of the newly developing “omics” techniques of analysis. This review will considered recent studies using high-throughput technologies and a nutrigenomic approach to reveal the patho-physiological effects that the fasting and postprandial lipoproteins may exert on the vascular wall.La aterosclerosis es una enfermedad en la que múltiples factores, entre los que se encuentra la dieta, contribuyen a la degradación de la pared vascular. En la etiología de la aterogénesis son determinantes las lipoproteínas plasmáticas y los distintos tipos celulares de la pared vascular, incluyendo una respuesta inflamatoria. La ingesta de alimentos afecta la concentración y composición de las lipoproteínas, ejerciendo un papel de riesgo o protector durante las diferentes etapas del proceso aterosclerótico. Es importante destacar que la naturaleza de las lipoproteínas y por lo tanto su papel en la enfermedad cardiovascular, también depende del tiempo transcurrido entre comidas. Por ejemplo, las lipoprote

  3. Correlation studies between serum concentrations of zinc and lipoproteins

    Energy Technology Data Exchange (ETDEWEB)

    Saiki, Mitiko; Alves, Edson R.; Vasconcellos, M.B.A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)], e-mail: mitiko@ipen.br, e-mail: eralves@ipen.br, e-mail: mbvascon@ipen.br; Sumita, Nairo M. [Universidade de Sao Paulo (USP), SP (Brazil). Hospital das Clinicas.Central Lab. Division and Laboratories of Medical Investigation (LIM-03)], e-mail: dlc.bioquimica@hcnet.usp.br; Jaluul, Omar; Jacob-Filho, Wilson [Universidade de Sao Paulo (USP), SP (Brazil). Faculdade de Medicina], e-mail: jaluul@uol.com.br, wiljac@usp.br

    2009-07-01

    In this study, serum zinc and lipoprotein concentrations were determined in order to assess the health status of an elderly population residing in Sao Paulo city, SP, Brazil. This population consisted of elderly considered healthy and participating of a 'Successful Ageing' program of the Sao Paulo University Medical School. Fasting blood samples were collected from 87 elderly individuals (63 females and 24 males) aged 60-91 and mean age of 72 +- 7 years. Zn concentrations were determined by neutron activation analysis at the IPEN/CNEN/ SP and, the lipoprotein (HDL, LDL and total cholesterol) concentrations were determined using routine analysis methods of the Central Laboratory Division, Hospital das Clinicas, FMUSP. Results obtained for Zn indicated that all the individuals presented this element within the recommended value. For total cholesterol and HDL-cholesterol concentrations, 96 % of elderly presented levels within the desired range but for LDL cholesterol concentrations only about 70.0 % of individuals were in the desired range. Serum concentration of Zn were positively correlated to LDL-cholesterol levels (correlation coefficient r = 0.21, p < 0.06). Furthermore, the ratios of [HDL-cholesterol] / [LDL-cholesterol] were negatively correlated with Zn concentrations (r = - 0.234, p < 0.04). The positive correlation found between the serum concentrations of Zn and LDL-cholesterol indicates the possible effect of this element in serum lipoprotein profiles. Thus ,these findings suggest that more investigations should be conducted on Zn supplementation in elderly subjects with cardiovascular diseases. (author)

  4. Characterization of the Pseudomonas aeruginosa Lol system as a lipoprotein sorting mechanism.

    Science.gov (United States)

    Tanaka, Shin-Ya; Narita, Shin-Ichiro; Tokuda, Hajime

    2007-05-04

    Escherichia coli lipoproteins are localized to either the inner or the outer membrane depending on the residue that is present next to the N-terminal acylated Cys. Asp at position 2 causes the retention of lipoproteins in the inner membrane. In contrast, the accompanying study (9) revealed that the residues at positions 3 and 4 determine the membrane specificity of lipoproteins in Pseudomonas aeruginosa. Since the five Lol proteins involved in the sorting of E. coli lipoproteins are conserved in P. aeruginosa, we examined whether or not the Lol proteins of P. aeruginosa are also involved in lipoprotein sorting but utilize different signals. The genes encoding LolCDE, LolA, and LolB homologues were cloned and expressed. The LolCDE homologue thus purified was reconstituted into proteoliposomes with lipoproteins. When incubated in the presence of ATP and a LolA homologue, the reconstituted LolCDE homologue released lipoproteins, leading to the formation of a LolA-lipoprotein complex. Lipoproteins were then incorporated into the outer membrane depending on a LolB homologue. As revealed in vivo, lipoproteins with Lys and Ser at positions 3 and 4, respectively, remained in proteoliposomes. On the other hand, E. coli LolCDE released lipoproteins with this signal and transferred them to LolA of not only E. coli but also P. aeruginosa. These results indicate that Lol proteins are responsible for the sorting of lipoproteins to the outer membrane of P. aeruginosa, as in the case of E. coli, but respond differently to inner membrane retention signals.

  5. Secretion of Bacterial Lipoproteins: Through the Cytoplasmic Membrane, the Periplasm and Beyond

    Science.gov (United States)

    Zückert, Wolfram R.

    2014-01-01

    Bacterial lipoproteins are peripherally anchored membrane proteins that play a variety of roles in bacterial physiology and virulence in monoderm (single membrane-enveloped, e.g., grampositive) and diderm (double membrane-enveloped, e.g., gram-negative) bacteria. After export of prolipoproteins through the cytoplasmic membrane, which occurs predominantly but not exclusively via the general secretory or Sec pathway, the proteins are lipid-modified at the cytoplasmic membrane in a multistep process that involves sequential modification of a cysteine residue and cleavage of the signal peptide by the signal II peptidase Lsp. In both monoderms and diderms, signal peptide processing is preceded by acylation with a diacylglycerol through preprolipoprotein diacylglycerol transferase (Lgt). In diderms but also some monoderms, lipoproteins are further modified with a third acyl chain through lipoprotein N-acyl transferase (Lnt). Fully modified lipoproteins that are destined to be anchored in the inner leaflet of the outer membrane (OM) are selected, transported and inserted by the Lol (lipoprotein outer membrane localization) pathway machinery, which consists of the inner-membrane (IM) ABC transporterlike LolCDE complex, the periplasmic LolA chaperone and the OM LolB lipoprotein receptor. Retention of lipoproteins in the cytoplasmic membrane results from Lol avoidance signals that were originally described as the “+2 rule”. Surface localization of lipoproteins in diderms is rare in most bacteria, with the exception of several spirochetal species. Type 2 (T2SS) and type 5 (T5SS) secretion systems are involved in secretion of specific surface lipoproteins of γ-proteobacteria. In the model spirochete Borrelia burgdorferi, surface lipoprotein secretion does not follow established sorting rules, but remains dependent on N-terminal peptide sequences. Secretion through the outer membrane requires maintenance of lipoproteins in a translocation-competent unfolded conformation

  6. Obtention of scintillography images by low density lipoproteins labelled with technetium 99

    International Nuclear Information System (INIS)

    Silva, S.; Coelho, I.; Zanardo, E.; Pileggi, F.; Meneguethi, C.; Maranhao, R.C.

    1992-01-01

    The low density lipoproteins carry the most part of the cholesterol in the blood plasma. These lipoproteins are labelled with technetium-99-m and have been used for obtaining images in nuclear medicine. The introduction of this technique is presented, aiming futures clinical uses. Scintillographic images are obtained 25 minutes and 24 hours after the injection of 3 m Ci of low density lipoproteins - technetium-99 m in rabbits. (C.G.C.)

  7. Biomimetic High Density Lipoprotein Nanoparticles For Nucleic Acid Delivery

    Science.gov (United States)

    McMahon, Kaylin M.; Mutharasan, R. Kannan; Tripathy, Sushant; Veliceasa, Dorina; Bobeica, Mariana; Shumaker, Dale K.; Luthi, Andrea J.; Helfand, Brian T.; Ardehali, Hossein; Mirkin, Chad A.; Volpert, Olga; Thaxton, C. Shad

    2014-01-01

    We report a gold nanoparticle-templated high density lipoprotein (HDL AuNP) platform for gene therapy which combines lipid-based nucleic acid transfection strategies with HDL biomimicry. For proof-of-concept, HDL AuNPs are shown to adsorb antisense cholesterylated DNA. The conjugates are internalized by human cells, can be tracked within cells using transmission electron microscopy (TEM), and regulate target gene expression. Overall, the ability to directly image the AuNP core within cells, the chemical tailorability of the HDL AuNP platform, and the potential for cell-specific targeting afforded by HDL biomimicry make this platform appealing for nucleic acid delivery. PMID:21319839

  8. Analyzing the molecular mechanism of lipoprotein localization in Brucella

    CSIR Research Space (South Africa)

    Goolab, S

    2015-10-01

    Full Text Available doi: 10.3389/fmicb.2015.01189 Edited by: Lee Mark Wetzler, Boston University School of Medicine, USA Reviewed by: Moriya Tsuji, Aaron Diamond AIDS Research Center, USA Thomas A. Ficht, Texas A&M University, USA *Correspondence: Shivani Goolab...-associated lipoproteins; POTRA, polypeptide-transport-associated; PRR, pattern-recognition receptors; RGD, Arg- Gly- Asp; Sec, system, general secretory; Tat system, twin-arginine translocation; T1SS, type I secretion system; T2SS, type II secretion system; T3SS, type III...

  9. Low density lipoprotein sensor based on surface plasmon resonance

    International Nuclear Information System (INIS)

    Matharu, Zimple; Sumana, G.; Pandey, M.K.; Gupta, Vinay; Malhotra, B.D.

    2009-01-01

    Biotinylated heparin has been immobilized onto self-assembled monolayer of 4-aminothiophenol using avidin-biotin specific binding. The modified electrodes have been characterized using surface plasmon resonance technique (SPR), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), atomic force microscopy (AFM) and contact angle (CA) measurements. The interaction of immobilized biotinylated heparin with low density lipoprotein (LDL) has been studied using surface plasmon resonance technique. The biotinylated heparin modified electrode can be used to detect LDL in the range of 20 to 100 mg/dl with the sensitivity of 513.3 m o /μM.

  10. Low density lipoprotein sensor based on surface plasmon resonance

    Energy Technology Data Exchange (ETDEWEB)

    Matharu, Zimple [Department of Science and Technology Centre on Biomolecular Electronics, National Physical Laboratory, Dr. K. S. Krishnan Marg, New Delhi-110012 (India); Department of Physics and Astrophysics, University of Delhi, New Delhi-110007 (India); Sumana, G.; Pandey, M.K. [Department of Science and Technology Centre on Biomolecular Electronics, National Physical Laboratory, Dr. K. S. Krishnan Marg, New Delhi-110012 (India); Gupta, Vinay [Department of Physics and Astrophysics, University of Delhi, New Delhi-110007 (India); Malhotra, B.D., E-mail: bansi.malhotra@gmail.co [Department of Science and Technology Centre on Biomolecular Electronics, National Physical Laboratory, Dr. K. S. Krishnan Marg, New Delhi-110012 (India)

    2009-11-30

    Biotinylated heparin has been immobilized onto self-assembled monolayer of 4-aminothiophenol using avidin-biotin specific binding. The modified electrodes have been characterized using surface plasmon resonance technique (SPR), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), atomic force microscopy (AFM) and contact angle (CA) measurements. The interaction of immobilized biotinylated heparin with low density lipoprotein (LDL) has been studied using surface plasmon resonance technique. The biotinylated heparin modified electrode can be used to detect LDL in the range of 20 to 100 mg/dl with the sensitivity of 513.3 m{sup o}/{mu}M.

  11. Low-density lipoproteins cause atherosclerotic cardiovascular disease

    DEFF Research Database (Denmark)

    Ference, Brian A.; Ginsberg, Henry N.; Graham, Ian

    2017-01-01

    Aims To appraise the clinical and genetic evidence that low-density lipoproteins (LDLs) cause atherosclerotic cardiovascular disease (ASCVD). Methods and results We assessed whether the association between LDL and ASCVD fulfils the criteria for causality by evaluating the totality of evidence from...... proportional to the absolute reduction in LDL-C and the cumulative duration of exposure to lower LDL-C, provided that the achieved reduction in LDL-C is concordant with the reduction in LDL particle number and that there are no competing deleterious off-target effects. Conclusion Consistent evidence from...

  12. Sphingolipids and Lipoproteins in Health and Metabolic Disorders.

    Science.gov (United States)

    Iqbal, Jahangir; Walsh, Meghan T; Hammad, Samar M; Hussain, M Mahmood

    2017-07-01

    Sphingolipids are structurally and functionally diverse molecules with significant physiologic functions and are found associated with cellular membranes and plasma lipoproteins. The cellular and plasma concentrations of sphingolipids are altered in several metabolic disorders and may serve as prognostic and diagnostic markers. Here we discuss various sphingolipid transport mechanisms and highlight how changes in cellular and plasma sphingolipid levels contribute to cardiovascular disease, obesity, diabetes, insulin resistance, and nonalcoholic fatty liver disease (NAFLD). Understanding of the mechanisms involved in intracellular transport, secretion, and extracellular transport may provide novel information that might be amenable to therapeutic targeting for the treatment of various metabolic disorders. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Cholesterol transfer from normal and atherogenic low density lipoproteins to Mycoplasma membranes

    International Nuclear Information System (INIS)

    Mitschelen, J.J.; St Clair, R.W.; Hester, S.H.

    1981-01-01

    The purpose of this study was to determine whether the free cholesterol of hypercholesterolemic low density lipoprotein from cholesterol-fed nonhuman primates has a greater potential for surface transfer to cell membranes than does the free cholesterol of normal low density lipoprotein. The low density lipoproteins were isolated from normal and hypercholesterolemic rhesus and cynomolgus monkeys, incubated with membranes from Acholeplasma laidlawii, a mycoplasma species devoid of cholesterol in its membranes, and the mass transfer of free cholesterol determined by measuring membrane cholesterol content. Since these membranes neither synthesize nor esterify cholesterol, nor degrade the protein or cholesterol ester moieties of low density lipoprotein, they are an ideal model with which to study differences in the cholesterol transfer potential of low density lipoprotein independent of the uptake of the intact low density lipoprotein particle. These studies indicate that, even though there are marked differences in the cholesterol composition of normal and hypercholesterolemic low density lipoproteins, this does not result in a greater chemical potential for surface transfer of free cholesterol. Consequently, if a difference in the surface transfer of free cholesterol is responsible for the enhanced ability of hypercholesterolemic low density lipoprotein to promote cellular cholesterol accumulation and, perhaps, also atherosclerosis, it must be the result of differences in the interaction to the hypercholesterolemic low density lipoprotein with the more complicated mammalian cell membranes, rather than differences in the chemical potential for cholesterol transfer

  14. Apolipoprotein B-containing lipoproteins and atherosclerotic cardiovascular disease [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Michael D. Shapiro

    2017-02-01

    Full Text Available Cholesterol-rich, apolipoprotein B (apoB-containing lipoproteins are now widely accepted as the most important causal agents of atherosclerotic cardiovascular disease. Multiple unequivocal and orthogonal lines of evidence all converge on low-density lipoprotein and related particles as being the principal actors in the genesis of atherosclerosis. Here, we review the fundamental role of atherogenic apoB-containing lipoproteins in cardiovascular disease and several other humoral and parietal factors that are required to initiate and maintain arterial degeneration. The biology of foam cells and their interactions with high-density lipoproteins, including cholesterol efflux, are also briefly reviewed.

  15. Defective Lipoprotein Sorting Induces lolA Expression through the Rcs Stress Response Phosphorelay System

    OpenAIRE

    Tao, Kazuyuki; Narita, Shin-ichiro; Tokuda, Hajime

    2012-01-01

    The Escherichia coli LolA protein is a lipoprotein-specific chaperone that carries lipoproteins from the inner to the outer membrane. A dominant negative LolA mutant, LolA(I93C/F140C), in which both 93Ile and 140Phe are replaced by Cys, binds tightly to the lipoprotein-dedicated ABC transporter LolCDE complex on the inner membrane and therefore inhibits the detachment of outer membrane-specific lipoproteins from the inner membrane. We found that the expression of this mutant strongly induced ...

  16. In vitro studies on the distribution of probucol among human plasma lipoproteins

    International Nuclear Information System (INIS)

    Urien, S.; Riant, P.; Albengres, E.; Brioude, R.; Tillement, J.P.

    1984-01-01

    The role of human plasma lipoproteins as carriers in the blood transport of the cholesterol-lowering and water-insoluble drug, probucol, was investigated in in vitro studies. [ 14 C]Probucol was incubated in whole human blood, a serum pool, individual diluted sera, and isolated protein and lipoprotein fractions. In whole blood, about 90% partitioned in plasma. Following ultracentrifugal fractionation of the serum, it was found that less than 5% distributed in the d greater than 1.20 protein fraction (albumin-rich fraction) and more than 95% in the lipoprotein fractions. The distribution of probucol in the lipoprotein fractions correlated with the lipoprotein total lipid volume under saturation conditions (incubation of isolated lipoprotein fractions) as well as nonsaturation conditions (fractionation of serum exposed to [ 14 C]probucol). Incubation of the albumin-rich fraction and of apolipoproteins originating from the isolated lipoprotein fractions showed that they account for a negligible part in the interaction of probucol with blood components. The probucol uptake of individual sera was shown to be correlated to the lipid content of the serum. When probucol was incubated in erythrocyte suspensions containing variable amounts of lipoproteins, probucol partitioned less in erythrocytes as the lipoprotein concentration increased in the suspension

  17. Native and Reconstituted Plasma Lipoproteins in Nanomedicine: Physicochemical Determinants of Nanoparticle Structure, Stability, and Metabolism.

    Science.gov (United States)

    Pownall, Henry J; Rosales, Corina; Gillard, Baiba K; Ferrari, Mauro

    2016-09-01

    Although many acute and chronic diseases are managed via pharmacological means, challenges remain regarding appropriate drug targeting and maintenance of therapeutic levels within target tissues. Advances in nanotechnology will overcome these challenges through the development of lipidic particles, including liposomes, lipoproteins, and reconstituted high-density lipoproteins (rHDL) that are potential carriers of water-soluble, hydrophobic, and amphiphilic molecules. Herein we summarize the properties of human plasma lipoproteins and rHDL, identify the physicochemical determinants of lipid transfer between phospholipid surfaces, and discuss strategies for increasing the plasma half-life of lipoprotein- and liposome-associated molecules.

  18. Wolbachia lipoproteins: abundance, localisation and serology of Wolbachia peptidoglycan associated lipoprotein and the Type IV Secretion System component, VirB6 from Brugia malayi and Aedes albopictus.

    Science.gov (United States)

    Voronin, Denis; Guimarães, Ana F; Molyneux, Gemma R; Johnston, Kelly L; Ford, Louise; Taylor, Mark J

    2014-10-06

    Lipoproteins are the major agonists of Wolbachia-dependent inflammatory pathogenesis in filariasis and a validated target for drug discovery. Here we characterise the abundance, localisation and serology of the Wolbachia lipoproteins: Wolbachia peptidoglycan associated lipoprotein and the Type IV Secretion System component, VirB6. We used proteomics to confirm lipoprotein presence and relative abundance; fractionation, immunoblotting and confocal and electron immuno-microscopy for localisation and ELISA for serological analysis. Proteomic analysis of Brugia malayi adult female protein extracts confirmed the presence of two lipoproteins, previously predicted through bioinformatics: Wolbachia peptidoglycan associated lipoprotein (wBmPAL) and the Type IV Secretion System component, VirB6 (wBmVirB6). wBmPAL was among the most abundant Wolbachia proteins present in an extract of adult female worms with wBmVirB6 only detected at a much lower abundance. This differential abundance was reflected in the immunogold-labelling, which showed wBmPAL localised at numerous sites within the bacterial membranes, whereas wBmVirB6 was present as a single cluster on each bacterial cell and also located within the bacterial membranes. Immunoblotting of fractionated extracts confirmed the localisation of wBmPAL to membranes and its absence from cytosolic fractions of C6/36 mosquito cells infected with wAlbB. In whole worm mounts, antibody labelling of both lipoproteins were associated with Wolbachia. Serological analysis showed that both proteins were immunogenic and raised antibody responses in the majority of individuals infected with Wuchereria bancrofti. Two Wolbachia lipoproteins, wBmPAL and wBmVirB6, are present in extracts of Brugia malayi with wBmPAL among the most abundant of Wolbachia proteins. Both lipoproteins localised to bacterial membranes with wBmVirB6 present as a single cluster suggesting a single Type IV Secretory System on each Wolbachia cell.

  19. Comparison of 2 electrophoretic methods and a wet-chemistry method in the analysis of canine lipoproteins.

    Science.gov (United States)

    Behling-Kelly, Erica

    2016-03-01

    The evaluation of lipoprotein metabolism in small animal medicine is hindered by the lack of a gold standard method and paucity of validation data to support the use of automated chemistry methods available in the typical veterinary clinical pathology laboratory. The physical and chemical differences between canine and human lipoproteins draw into question whether the transference of some of these human methodologies for the study of canine lipoproteins is valid. Validation of methodology must go hand in hand with exploratory studies into the diagnostic or prognostic utility of measuring specific lipoproteins in veterinary medicine. The goal of this study was to compare one commercially available wet-chemistry method to manual and automated lipoprotein electrophoresis in the analysis of canine lipoproteins. Canine lipoproteins from 50 dogs were prospectively analyzed by 2 electrophoretic methods, one automated and one manual method, and one wet-chemistry method. Electrophoretic methods identified a higher proportion of low-density lipoproteins than the wet-chemistry method. Automated electrophoresis occasionally failed to identify very low-density lipoproteins. Wet-chemistry methods designed for evaluation of human lipoproteins are insensitive to canine low-density lipoproteins and may not be applicable to the study of canine lipoproteins. Automated electrophoretic methods will likely require significant modifications if they are to be used in the analysis of canine lipoproteins. Studies aimed at determining the impact of a disease state on lipoproteins should thoroughly investigate the selected methodology prior to the onset of the study. © 2016 American Society for Veterinary Clinical Pathology.

  20. Triglyceride-rich lipoproteins and high-density lipoprotein cholesterol in patients at high risk of cardiovascular disease: evidence and guidance for management

    DEFF Research Database (Denmark)

    Chapman, M John; Ginsberg, Henry N; Amarenco, Pierre

    2011-01-01

    Even at low-density lipoprotein cholesterol (LDL-C) goal, patients with cardiometabolic abnormalities remain at high risk of cardiovascular events. This paper aims (i) to critically appraise evidence for elevated levels of triglyceride-rich lipoproteins (TRLs) and low levels of high......-density lipoprotein cholesterol (HDL-C) as cardiovascular risk factors, and (ii) to advise on therapeutic strategies for management. Current evidence supports a causal association between elevated TRL and their remnants, low HDL-C, and cardiovascular risk. This interpretation is based on mechanistic and genetic...

  1. Direct solid phase radioimmunoassay for chicken lipoprotein lipase

    International Nuclear Information System (INIS)

    Cheung, A.H.; Bensadoun, A.; Cheng, C.

    1979-01-01

    A direct, noncompetitive immunoassay for chicken lipoprotein lipase (LPL) was developed. Antibodies to LPL were purified by immunoadsorption chromatography of goat antisera on an LPL-Sepharose column. Purified anti-LPL immunoglobulins were coupled covalently to hydrophilic polyacrylamide beads by a carbodiimide reagent. An excess amount of these beads was incubated with the sample on the standard to be assayed. The amount of LPL immobilized by the heads was then detected by an excess amount of 125 I-labeled anti-LPL immunoglobulin. A linear relationship was obtained between the radioactivity bound and the amount of highly purified LPL used as a standard. The range of the assay was from 0.1 to 1.1 ng PLP. The assay was specific for chicken LPL and showed no cross-reactivity with liver lipase. It does not distinguish heat-inactivated from catalytically active enzyme species. This assay should be useful in studies of lipoprotein lipase where both catalytic activity and enzyme mass need to be quantitated

  2. Transport of cholesterol autoxidation products in rabbit lipoproteins

    International Nuclear Information System (INIS)

    Peng, Shi-Kaung; Phillips, G.A.; Xia, Guang-Zhi; Morin, R.J.

    1987-01-01

    Radiolabeled pure [4- 14 C] cholesterol was kept at 60 0 C under air to autoxidize for 5 weeks, after which approximately 12% cholesterol oxidation products were formed. The mixture, suspended in gelatin, was given to rabbits by gastric gavage. Rabbits were killed 4, 24 and 48 h after treatment. Cholesterol and its autoxidation products were separated by thin-layer chromatography into 5 fractions and radioactivities of each fraction were measured. Percentages of each fraction of cholesterol oxidation products and cholesterol in the original mixture before administration and in the rabbit sera after administration were similar, suggesting that the rates of absorption of cholesterol oxidation products are not significantly different from that of cholesterol. Lipoproteins were fractioned by ultracentrifugation into VLDL, LDL and HDL. Radioactivities of each fraction in lipoproteins separated by thin layer chromatography showed that fractions containing cholestane-3β, 5α, 6β-triol, 7α- and 7β-hydroxycholesterol and 7-ketocholesterol were more selectively transported in VLDL, whereas most of the 25-hydroxycholesterol was present in LDL. HDL contained only minute amounts of cholesterol oxidation products. 22 refs

  3. A Trimeric Lipoprotein Assists in Trimeric Autotransporter Biogenesis in Enterobacteria*

    Science.gov (United States)

    Grin, Iwan; Hartmann, Marcus D.; Sauer, Guido; Hernandez Alvarez, Birte; Schütz, Monika; Wagner, Samuel; Madlung, Johannes; Macek, Boris; Felipe-Lopez, Alfonso; Hensel, Michael; Lupas, Andrei; Linke, Dirk

    2014-01-01

    Trimeric autotransporter adhesins (TAAs) are important virulence factors of many Gram-negative bacterial pathogens. TAAs form fibrous, adhesive structures on the bacterial cell surface. Their N-terminal extracellular domains are exported through a C-terminal membrane pore; the insertion of the pore domain into the bacterial outer membrane follows the rules of β-barrel transmembrane protein biogenesis and is dependent on the essential Bam complex. We have recently described the full fiber structure of SadA, a TAA of unknown function in Salmonella and other enterobacteria. In this work, we describe the structure and function of SadB, a small inner membrane lipoprotein. The sadB gene is located in an operon with sadA; orthologous operons are only found in enterobacteria, whereas other TAAs are not typically associated with lipoproteins. Strikingly, SadB is also a trimer, and its co-expression with SadA has a direct influence on SadA structural integrity. This is the first report of a specific export factor of a TAA, suggesting that at least in some cases TAA autotransport is assisted by additional periplasmic proteins. PMID:24369174

  4. Lipoprotein (a and cardiovascular risk factors in children and adolescents

    Directory of Open Access Journals (Sweden)

    Ástrid Camêlo Palmeira

    2013-12-01

    Full Text Available OBJECTIVE: To review the relationship between lipoprotein (a [Lp(a] and other risk factors for cardiovascular disease (CVD in children and adolescents. DATA SOURCES: This systematic review included studies from 2001 to 2011, a ten-year time period. Epidemiological studies with children and/or adolescents published in English, Portuguese or Spanish and fully available online were included. The searches were performed in Science Direct, PubMed/Medline, BVS (Biblioteca Virtual em Saúde and Cochrane Library databases, using the following combination of key-words: "lipoprotein a" and "cardiovascular diseases" and "obesity". DATA SYNTHESIS: Overall, 672 studies were obtained but only seven were included. Some studies assessed the family history for CVD. In all of them, Lp(a levels were increased in patients with family history for CVD. There was also a positive correlation between Lp(a and LDL-cholesterol, total cholesterol, and apolipoprotein B levels, suggesting an association between Lp(a levels and the lipid profile. CONCLUSIONS: The evidence that CVD may originate in childhood and adolescence leads to the need for investigating the risk factors during this period in order to propose earlier and possibly more effective interventions to reduce morbidity and mortality rates.

  5. Lipoprotein (a) and cardiovascular risk factors in children and adolescents.

    Science.gov (United States)

    Palmeira, Ástrid Camêlo; Leal, Adriana Amorim de F; Ramos, Nathaly de Medeiros N; Neto, José de Alencar F; Simões, Mônica Oliveira da S; Medeiros, Carla Campos M

    2013-12-01

    To review the relationship between lipoprotein (a) [Lp(a)] and other risk factors for cardiovascular disease (CVD) in children and adolescents. This systematic review included studies from 2001 to 2011, a ten-year time period. Epidemiological studies with children and/or adolescents published in English, Portuguese or Spanish and fully available online were included. The searches were performed in Science Direct, PubMed/Medline, BVS (Biblioteca Virtual em Saúde) and Cochrane Library databases, using the following combination of key-words: "lipoprotein a" and "cardiovascular diseases" and "obesity". Overall, 672 studies were obtained but only seven were included. Some studies assessed the family history for CVD. In all of them, Lp(a) levels were increased in patients with family history for CVD. There was also a positive correlation between Lp(a) and LDL-cholesterol, total cholesterol, and apolipoprotein B levels, suggesting an association between Lp(a) levels and the lipid profile. The evidence that CVD may originate in childhood and adolescence leads to the need for investigating the risk factors during this period in order to propose earlier and possibly more effective interventions to reduce morbidity and mortality rates.

  6. Influence of medium components on the expression of recombinant lipoproteins in Escherichia coli.

    Science.gov (United States)

    Tseng, Chi-Ling; Leng, Chih-Hsiang

    2012-02-01

    Bacterial lipoproteins are crucial antigens for protective immunity against bacterial pathogens. Expression of exogenous lipoproteins in Escherichia coli at high levels is thought to be an extremely difficult endeavor because it frequently results in incomplete or absent lipid modification. Previously, we identified a fusion sequence (D1) from a Neisseria meningitidis lipoprotein that induced a non-lipidated protein, E3 (the domain III of the dengue virus envelope protein), to become lipidated. However, without optimizing the growth conditions, some of the D1-fusion proteins were not lipidated. Here, we report the influence of medium components on the expression of recombinant lipoproteins in E. coli. For high-level expression of mature lipoproteins in the C43 (DE3) strain, M9 medium was better than M63 and the rich medium. Furthermore, we analyzed the influence of other media factors (including nitrogen and carbon sources, phosphate, ferrous ions, calcium, magnesium, and pH) on the levels of lipoprotein expression. The results showed that excess nitrogen sources and phosphate in M9 medium could increase the amount of immature lipoproteins, and glucose was a better carbon source than glycerol for expressing mature lipoproteins. We also found that lipoproteins tended to be completely processed in the alkaline environment, even in the nutrient-rich medium. Additional constructs expressing different immunogens or lipid signal peptides as targets were also utilized, demonstrating that these targets could be expressed as completely mature lipoproteins in the M9 medium but not in the rich medium. Our results provide the useful information for expressing mature exogenous lipoproteins in E. coli.

  7. Lipoprotein Transport: Greasing the Machines of Outer Membrane Biogenesis: Re-Examining Lipoprotein Transport Mechanisms Among Diverse Gram-Negative Bacteria While Exploring New Discoveries and Questions.

    Science.gov (United States)

    Grabowicz, Marcin

    2018-04-01

    The Gram-negative outer membrane (OM) is a potent permeability barrier against antibiotics, limiting clinical options amid mounting rates of resistance. The Lol transport pathway delivers lipoproteins to the OM. All the OM assembly machines require one or more OM lipoprotein to function, making the Lol pathway central for all aspects of OM biogenesis. The Lol pathways of many medically important species clearly deviate from the Escherichia coli paradigm, perhaps with implications for efforts to develop novel antibiotics. Moreover, recent work reveals the existence of an undiscovered alternate route for bringing lipoproteins to the OM. Here, lipoprotein transport mechanisms, and the quality control systems that underpin them, is re-examined in context of their diversity. © 2018 WILEY Periodicals, Inc.

  8. Increased fluidity and oxidation of malarial lipoproteins: relation with severity and induction of endothelial expression of adhesion molecules

    Directory of Open Access Journals (Sweden)

    Looareesuwan Sornchai

    2004-06-01

    Full Text Available Abstract Introduction Oxidative stress has been demonstrated in malaria. The potential oxidative modification of lipoproteins derived from malaria patients was studied. These oxidized lipids may have role in pathogenesis of malaria. Method The plasma lipid profile and existence of oxidized forms of very low density lipoprotein (VLDL, low density lipoprotein (LDL and high density lipoprotein (HDL were investigated in malaria (17 mild and 24 severe patients and 37 control subjects. Thiobarbituric acid reactive substances (TBARs, conjugated dienes, tryptophan fluorescence and fluidity of lipoproteins were determined as markers of oxidation. The biological effect of malarial lipoproteins was assessed by the expression of adhesion molecules on endothelial cells. Results Malarial lipoproteins had decreased cholesterol (except in VLDL and phospholipid. The triglyceride levels were unchanged. The cholesterol/phospholipid ratio of LDL was decreased in malaria, but increased in VLDL and HDL. TBARs and conjugate dienes were increased in malarial lipoproteins, while the tryptophan fluorescence was decreased. The fluidity of lipoproteins was increased in malaria. These indicated the presence of oxidized lipoproteins in malaria by which the degree of oxidation was correlated with severity. Of three lipoproteins from malarial patients, LDL displayed the most pronounced oxidative modification. In addition, oxidized LDL from malaria patients increased endothelial expression of adhesion molecules. Conclusion In malaria, the lipoproteins are oxidatively modified, and the degree of oxidation is related with severity. Oxidized LDL from malarial patients increases the endothelial expression of adhesion molecules. These suggest the role of oxidized lipoproteins, especially LDL, on the pathogenesis of disease.

  9. Lipoprotein distribution and serum concentrations of 7α-hydroxy-4-cholesten-3-one and bile acids: effects of monogenic disturbances in high-density lipoprotein metabolism

    DEFF Research Database (Denmark)

    Steiner, Carine; Holleboom, Adriaan G; Karuna, Ratna

    2012-01-01

    BA (bile acid) formation is considered an important final step in RCT (reverse cholesterol transport). HDL (high-density lipoprotein) has been reported to transport BAs. We therefore investigated the effects of monogenic disturbances in human HDL metabolism on serum concentrations and lipoprotein...... concentrations of conjugated and secondary BAs differed between heterozygous carriers of SCARB1 (scavenger receptor class B1) mutations and unaffected individuals (P...

  10. Effects of Anabolic Steroids on Lipoprotein Profiles of Female Weight Lifters.

    Science.gov (United States)

    Moffatt, Robert J.; And Others

    1990-01-01

    This study examined the effects of resistance exercise and anabolic steroids on lipoprotein profiles of female weightlifters. The study found that women who participate in resistance training have better lipoprotein profiles than their sedentary counterparts, but these changes do not offset the deleterious effects of steroid use. (SM)

  11. Should we change our lipid management strategies to focus on non-high-density lipoprotein cholesterol?

    NARCIS (Netherlands)

    Rana, Jamal S.; Boekholdt, S. Matthijs

    2010-01-01

    Purpose of review Despite aggressive low-density lipoprotein cholesterol lowering, patients continue to be at significant risk of cardiovascular events. Assessment of non-high-density lipoprotein cholesterol (non-HDL-C) provides a measure of cholesterol contained in all atherogenic particles. In the

  12. Analysis of lipoproteins by capillary zone electrophoresis in microfluidic devices: Assay development and surface roughness measurements

    NARCIS (Netherlands)

    Weiller, Bruce H.; Ceriotti, Laura; Shibata, Takayuki; Rein, Dietrich; Roberts, Matthew A.; Lichtenberg, Jan; German, J. Bruce; De Rooij, Nico F.; Verpoorte, Elisabeth

    2002-01-01

    The development of a new assay for lipoproteins by capillary electrophoresis in fused-silica capillaries and in glass microdevices is described in this paper. The separation of low-density (LDL) and high-density (HDL) lipoproteins by capillary zone electrophoresis is demonstrated in fused-silica

  13. Overexpression of porcine lipoprotein-associated phospholipase A2 in swine

    NARCIS (Netherlands)

    Tang, Xiaochun; Wang, Gangqi; Liu, Xingxing; Han, Xiaolei; Li, Zhuang; Ran, Guangyao; Li, Zhanjun; Song, Qi; Ji, Y; Wang, Haijun; Wang, Yuhui; Ouyang, Hongsheng; Pang, Daxin

    2015-01-01

    Lipoprotein-associated phospholipase A 2 (Lp-PLA2) is associated with the risk of vascular disease. It circulates in human blood predominantly in association with low-density lipoprotein cholesterol (LDL-C) and hydrolyses oxidized phospholipids into pro-inflammatory products. However, in the mouse

  14. Apolipoprotein(a) phenotypes and lipoprotein(a) concentrations in patients with hyperthyroidism

    DEFF Research Database (Denmark)

    Klausen, I C; Hegedüs, L; Hansen, P S

    1995-01-01

    Lipoprotein(a) [Lp(a)] is a low-density lipoprotein (LDL) particle in which apolipoprotein B-100 (apoB) is attached to a glycoprotein called apolipoprotein(a) [apo(a)]. Apo(a) has several genetically determined phenotypes differing in molecular weight, to which Lp(a) concentrations in plasma are ...

  15. Changes in lipids and lipoprotein particle concentrations after interruption of antiretroviral therapy

    DEFF Research Database (Denmark)

    Lampe, Fiona C; Duprez, Daniel A; Kuller, Lewis H

    2010-01-01

    The effect of interruption of antiretroviral therapy (ART) on lipoprotein particle subclasses has not been studied. We examined short-term changes in lipids and lipoprotein particles among 332 HIV-infected individuals randomized to interrupt or continue ART in the "Strategies for Management...

  16. Lipoprotein(a) concentration and the risk of coronary heart disease, stroke, and nonvascular mortality

    DEFF Research Database (Denmark)

    (Tybjaerg-Hansen, A.) The Fibrinogen Studies Collaboration.The Copenhagen City Heart Study; Tybjærg-Hansen, Anne

    2009-01-01

    CONTEXT: Circulating concentration of lipoprotein(a) (Lp[a]), a large glycoprotein attached to a low-density lipoprotein-like particle, may be associated with risk of coronary heart disease (CHD) and stroke. OBJECTIVE: To assess the relationship of Lp(a) concentration with risk of major vascular...

  17. Human luteinized granulosa cells secrete apoB100-containing lipoproteins

    NARCIS (Netherlands)

    Gautier, Thomas; Becker, Steffi; Drouineaud, Veronique; Menetrier, Franck; Sagot, Paul; Nofer, Jerzy-Roch; von Otte, Soeren; Lagrost, Laurent; Masson, David; Tietge, Uwe J. F.

    Thus far, liver, intestine, heart, and placenta have been shown to secrete apolipoprotein (apo) B-containing lipoproteins. In the present study, we first investigated lipoproteins in human follicular fluid (FF), surrounding developing oocytes within the ovary, as well as in corresponding plasma

  18. Plasma lipoprotein(a) levels in patients with homozygous autosomal dominant hypercholesterolemia

    NARCIS (Netherlands)

    Sjouke, Barbara; Yahya, Reyhana; Tanck, Michael W. T.; Defesche, Joep C.; de Graaf, Jacqueline; Wiegman, Albert; Kastelein, John J. P.; Mulder, Monique T.; Hovingh, G. Kees; Roeters van Lennep, Jeanine E.

    2017-01-01

    Patients with autosomal dominant hypercholesterolemia (ADH), caused by mutations in either low-density lipoprotein receptor (LDLR), apolipoprotein B (APOB), or proprotein convertase subtilisin-kexin type 9 (PCSK9) are characterized by high low-density lipoprotein cholesterol levels and in some

  19. Plasma lipoprotein(a) levels in patients with homozygous autosomal dominant hypercholesterolemia

    NARCIS (Netherlands)

    Sjouke, B.; Yahya, R.; Tanck, M.W.T.; Defesche, J.C.; Graaf, J. de; Wiegman, A.; Kastelein, J.J.; Mulder, M.T.; Hovingh, G.K.; Roeters van Lennep, J.E.

    2017-01-01

    BACKGROUND: Patients with autosomal dominant hypercholesterolemia (ADH), caused by mutations in either low-density lipoprotein receptor (LDLR), apolipoprotein B (APOB), or proprotein convertase subtilisin-kexin type 9 (PCSK9) are characterized by high low-density lipoprotein cholesterol levels and

  20. Oxidized low-density lipoprotein in children with familial hypercholesterolemia and unaffected siblings: effect of pravastatin

    NARCIS (Netherlands)

    Rodenburg, Jessica; Vissers, Maud N.; Wiegman, Albert; Miller, Elizabeth R.; Ridker, Paul M.; Witztum, Joseph L.; Kastelein, John J. P.; Tsimikas, Sotirios

    2006-01-01

    OBJECTIVES: To assess the role of oxidized phospholipids (OxPLs) in children with familial hypercholesterolemia (FH) and the effect of pravastatin. BACKGROUND: Oxidized phospholipids are a major component of oxidized low-density lipoprotein (OxLDL) and are bound to lipoprotein (a) [Lp(a)]. The

  1. Lipoprotein(a) and ischemic heart disease-A causal association? A review

    DEFF Research Database (Denmark)

    Kamstrup, P.R.

    2010-01-01

    association of LPA copy number variants, influencing levels of lipoprotein(a), with risk of IHD. In conclusion, results from epidemiologic, in vitro, animal, and genetic epidemiologic studies support a causal association of lipoprotein(a) with risk of IHD, while results from randomized clinical trials...

  2. Quantification of lipoprotein profiles by nuclear magnetic resonance spectroscopy and multivariate data analysis

    DEFF Research Database (Denmark)

    Aru, Violetta; Lam, Chloie; Khakimov, Bekzod

    2017-01-01

    Lipoproteins and their subfraction profiles have been associated to diverse diseases including Cardio Vascular Disease (CVD). There is thus a great demand for measuring and quantifying the lipoprotein profile in an efficient and accurate manner. Nuclear Magnetic Resonance (NMR) spectroscopy is un...

  3. ApoE and the role of very low density lipoproteins in adipose tissue inflammation

    Science.gov (United States)

    Our goal was too identify the role of triglyceride-rich lipoproteins and apoE, a major apolipoprotein in triglyceride-rich lipoproteins, in adipose tissue inflammation with high-fat diet induced obesity. Male apoE-/- and C57BL/6J wild-type mice fed high fat diets for 12 weeks were assessed for metab...

  4. Serum amyloid A is found on ApoB-containing lipoproteins in obese humans with diabetes.

    Science.gov (United States)

    Jahangiri, Anisa; Wilson, Patricia G; Hou, Tianfei; Brown, Aparna; King, Victoria L; Tannock, Lisa R

    2013-05-01

    In murine models of obesity/diabetes, there is an increase in plasma serum amyloid A (SAA) levels along with redistribution of SAA from high-density lipoprotein (HDL) to apolipoprotein B (apoB)-containing lipoprotein particles, namely, low-density lipoprotein and very low-density lipoprotein. The goal of this study was to determine if obesity is associated with similar SAA lipoprotein redistribution in humans. Three groups of obese individuals were recruited from a weight loss clinic: healthy obese (n = 14), metabolic syndrome (MetS) obese (n = 8), and obese with type 2 diabetes (n = 6). Plasma was separated into lipoprotein fractions by fast protein liquid chromatography, and SAA was measured in lipid fractions using enzyme-linked immunosorbent assay and Western blotting. Only the obese diabetic group had SAA detectable in apoB-containing lipoproteins, and SAA reverted back to HDL with active weight loss. In human subjects, SAA is found in apoB-containing lipoprotein particles only in obese subjects with type 2 diabetes, but not in healthy obese or obese subjects with MetS. Copyright © 2012 The Obesity Society.

  5. The effect of interaction between Lipoprotein Lipase and ApoVLDL-II ...

    African Journals Online (AJOL)

    Body weight, abdominal fat weight and serum biochemical levels were determined from lean and fat chicken breeds at 12 weeks of age. Single nucleotide polymorphism (SNP) in apoVLDL-II and lipoprotein lipase genes was screened by PCR-SSCP and detected by direct sequencing. Lipoprotein lipase gene frequency ...

  6. Mycobacterium tuberculosis lipoproteins in virulence and immunity - fighting with a double-edged sword.

    Science.gov (United States)

    Becker, Katja; Sander, Peter

    2016-11-01

    Bacterial lipoproteins are secreted membrane-anchored proteins characterized by a lipobox motif. This lipobox motif directs post-translational modifications at the conserved cysteine through the consecutive action of three enzymes: Lgt, LspA and Lnt, which results in di- or triacylated forms. Lipoproteins are abundant in all bacteria including Mycobacterium tuberculosis and often involved in virulence and immunoregulatory processes. On the one hand, disruption of the biosynthesis pathway of lipoproteins leads to attenuation of M. tuberculosis in vivo, and mycobacteria deficient for certain lipoproteins have been assessed as attenuated live vaccine candidates. On the other hand, several mycobacterial lipoproteins form immunodominant antigens which promote an immune response. Some of these have been explored in DNA or subunit vaccination approaches against tuberculosis. The immune recognition of specific lipoproteins, however, might also benefit long-term survival of M. tuberculosis through immune modulation, while others induce protective responses. Exploiting lipoproteins as vaccines is thus a complex matter which requires deliberative investigation. The dual role of lipoproteins in the immunity to and pathogenicity of mycobacteria is discussed here. © 2016 Federation of European Biochemical Societies.

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

    DEFF Research Database (Denmark)

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

    2010-01-01

    Rationale: Plasma apolipoprotein (apo)M is mainly associated with high-density lipoprotein (HDL). HDL-bound apoM is antiatherogenic in vitro. However, plasma apoM is not associated with coronary heart disease in humans, perhaps because of a positive correlation with plasma low-density lipoprotein...

  8. Formation of tissue factor activity following incubation of recombinant human tissue factor apoprotein with plasma lipoproteins

    International Nuclear Information System (INIS)

    Sakai, T.; Kisiel, W.

    1990-01-01

    Incubation of recombinant human tissue factor apoprotein (Apo-TF) with human plasma decreased the recalcified clotting time of this plasma in a time-and dose-dependent manner suggesting relipidation of the Apo-TF by plasma lipoproteins. Incubation of Apo-TF with purified preparations of human very low density, low density and high density lipoproteins resulted in tissue factor activity in a clotting assay. The order of effectiveness was VLDL greater than LDL much greater than HDL. Tissue factor activity generated by incubation of a fixed amount of Apo-TF with plasma lipoproteins was lipoprotein concentration-dependent and saturable. The association of Apo-TF with lipoprotein particles was supported by gel filtration studies in which 125 I-Apo-TF coeluted with the plasma lipoprotein in the void volume of a Superose 6 column in the presence and absence of calcium ions. In addition, void-volume Apo-TF-lipoprotein fractions exhibited tissue factor activity. These results suggest that the factor VIII-bypassing activity of bovine Apo-TF observed in a canine hemophilic model may be due, in part, to its association with plasma lipoproteins and expression of functional tissue factor activity

  9. Characterization and Purification of Polydisperse Reconstituted Lipoproteins and Nanolipoprotein Particles

    Directory of Open Access Journals (Sweden)

    Paul D. Hoeprich

    2009-07-01

    Full Text Available Heterogeneity is a fact that plagues the characterization and application of many self-assembled biological constructs. The importance of obtaining particle homogeneity in biological assemblies is a critical goal, as bulk analysis tools often require identical species for reliable interpretation of the results—indeed, important tools of analysis such as x-ray diffraction typically require over 90% purity for effectiveness. This issue bears particular importance in the case of lipoproteins. Lipid-binding proteins known as apolipoproteins can self assemble with liposomes to form reconstituted high density lipoproteins (rHDLs or nanolipoprotein particles (NLPs when used for biotechnology applications such as the solubilization of membrane proteins. Typically, the apolipoprotein and phospholipids reactants are self assembled and even with careful assembly protocols the product often contains heterogeneous particles. In fact, size polydispersity in rHDLs and NLPs published in the literature are frequently observed, which may confound the accurate use of analytical methods. In this article, we demonstrate a procedure for producing a pure, monodisperse NLP subpopulation from a polydisperse self-assembly using size exclusion chromatography (SEC coupled with high resolution particle imaging by atomic force microscopy (AFM. In addition, NLPs have been shown to self assemble both in the presence and absence of detergents such as cholate, yet the effects of cholate on NLP polydispersity and separation has not been systematically examined. Therefore, we examined the separation properties of NLPs assembled in both the absence and presence of cholate using SEC and native gel electrophoresis. From this analysis, NLPs prepared with and without cholate showed particles with well defined diameters spanning a similar size range. However, cholate was shown to have a dramatic affect on NLP separation by SEC and native gel electrophoresis. Furthermore, under

  10. Surface-Exposed Lipoproteins: An Emerging Secretion Phenomenon in Gram-Negative Bacteria.

    Science.gov (United States)

    Wilson, Marlena M; Bernstein, Harris D

    2016-03-01

    Bacterial lipoproteins are hydrophilic proteins that are anchored to a cell membrane by N-terminally linked fatty acids. It is widely believed that nearly all lipoproteins produced by Gram-negative bacteria are either retained in the inner membrane (IM) or transferred to the inner leaflet of the outer membrane (OM). Lipoproteins that are exposed on the cell surface have also been reported but are generally considered to be rare. Results from a variety of recent studies, however, now suggest that the prevalence of surface-exposed lipoproteins has been underestimated. In this review we describe the evidence that the surface exposure of lipoproteins in Gram-negative bacteria is a widespread phenomenon and discuss possible mechanisms by which these proteins might be transported across the OM. Published by Elsevier Ltd.

  11. Effect of omega-3 fatty acids on the oxylipin composition of lipoproteins in hypertriglyceridemic, statin-treated subjects

    Science.gov (United States)

    Background: Oxylipins mediate many physiological processes, including inflammation and vascular function. Generally considered local and transient, we suggest their presence in lipoproteins indicates they also mediate the effects lipoproteins have on inflammation and vascular biology. To support th...

  12. Low density lipoprotein receptors: preliminary results on 'in vivo' study

    International Nuclear Information System (INIS)

    Lupattelli, G.; Virgolini, I.; Li, S.R.; Sinzinger, H.

    1991-01-01

    Plasmatic levels of low density lipoproteins (LDL) are regulated by the receptor pathway and most LDL receptor are located in the liver. A receptor defect due to genetic mutations of the LDL receptor gene is the cause of familial hypercholesterolemia (F.H.), a disease characterized by high cholesterol levels and premature atherosclerosis. Injections of autologous radiolabelled LDL, followed by hepatic scintiscanning, can be used to obtain 'in vivo' quantification of hepatic receptor activity, both in normal and hypercholesterolemic patients. In this study we observe no hepatic increase of radioactivity in patients affected by F.H., confirming the liver receptor defect. Scintigraphy is a non-invasive technique which can be used to diagnose this disease and to monitor the efficiacy of hypolipidemic therapy. (Authors)

  13. Methylation status regulates lipoprotein lipase expression in chronic lymphocytic leukemia.

    Science.gov (United States)

    Abreu, Cecilia; Moreno, Pilar; Palacios, Florencia; Borge, Mercedes; Morande, Pablo; Landoni, Ana Inés; Gabus, Raul; Dighiero, Guillermo; Giordano, Mirta; Gamberale, Romina; Oppezzo, Pablo

    2013-08-01

    Among different prognostic factors in chronic lymphocytic leukemia (CLL), we previously demonstrated that lipoprotein lipase (LPL) is associated with an unmutated immunoglobulin profile and clinical poor outcome. Despite the usefulness of LPL for CLL prognosis, its functional role and the molecular mechanism regulating its expression are still open questions. Interaction of CLL B-cells with the tissue microenvironment favors disease progression by promoting malignant B-cell growth. Since tissue methylation can be altered by environmental factors, we investigated the methylation status of the LPL gene and the possibility that overexpression could be associated with microenvironment signals. Our results show that a demethylated state of the LPL gene is responsible for its anomalous expression in unmutated CLL cases and that this expression is dependent on microenvironment signals. Overall, this work proposes that an epigenetic mechanism, triggered by the microenvironment, regulates LPL expression in CLL disease.

  14. Lipoprotein Lipase Maintains Microglial Innate Immunity in Obesity

    Directory of Open Access Journals (Sweden)

    Yuanqing Gao

    2017-09-01

    Full Text Available Consumption of a hypercaloric diet upregulates microglial innate immune reactivity along with a higher expression of lipoprotein lipase (Lpl within the reactive microglia in the mouse brain. Here, we show that knockdown of the Lpl gene specifically in microglia resulted in deficient microglial uptake of lipid, mitochondrial fuel utilization shifting to glutamine, and significantly decreased immune reactivity. Mice with knockdown of the Lpl gene in microglia gained more body weight than control mice on a high-carbohydrate high-fat (HCHF diet. In these mice, microglial reactivity was significantly decreased in the mediobasal hypothalamus, accompanied by downregulation of phagocytic capacity and increased mitochondrial dysmorphologies. Furthermore, HCHF-diet-induced POMC neuronal loss was accelerated. These results show that LPL-governed microglial immunometabolism is essential to maintain microglial function upon exposure to an HCHF diet. In a hypercaloric environment, lack of such an adaptive immunometabolic response has detrimental effects on CNS regulation of energy metabolism.

  15. Lipoprotein(a Induces Human Aortic Valve Interstitial Cell Calcification

    Directory of Open Access Journals (Sweden)

    Bin Yu, PhD

    2017-08-01

    Full Text Available Lipoprotein(a, or Lp(a, significantly increased alkaline phosphatase activity, release of phosphate, calcium deposition, hydroxyapatite, cell apoptosis, matrix vesicle formation, and phosphorylation of signal transduction proteins; increased expression of chondro-osteogenic mediators; and decreased SOX9 and matrix Gla protein (p < 0.001. Inhibition of MAPK38 and GSK3β significantly reduced Lp(a-induced calcification of human aortic valve interstitial cells (p < 0.001. There was abundant presence of Lp(a and E06 immunoreactivity in diseased human aortic valves. The present study demonstrates a causal effect for Lp(a in aortic valve calcification and suggests that interfering with the Lp(apathway could provide a novel therapeutic approach in the management of this debilitating disease.

  16. Changes in plasma low-density lipoprotein (LDL)- and high-density lipoprotein cholesterol in hypo- and hyperthyroid patients are related to changes in free thyroxine, not to polymorphisms in LDL receptor or cholesterol ester transfer protein genes

    NARCIS (Netherlands)

    Diekman, M. J.; Anghelescu, N.; Endert, E.; Bakker, O.; Wiersinga, W. M.

    2000-01-01

    Thyroid function disorders lead to changes in lipoprotein metabolism. Both plasma low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) increase in hypothyroidism and decrease in hyperthyroidism. Changes in LDL-C relate to altered clearance of LDL particles

  17. Biominetic High Density Lipoproteins for the Delivery of Therapeutic Oligonucleotides

    Science.gov (United States)

    Tripathy, Sushant

    Advances in nanotechnology have brought about novel inorganic and hybrid nanoparticles with unique physico-chemical properties that make them suitable for a broad range of applications---from nano-circuitry to drug delivery. A significant part of those advancements have led to ground-breaking discoveries that have changed the approaches to formulation of therapeutics against diseases, such as cancer. Now-a-days the focus does not lie solely on finding a candidate small-molecule therapeutic with minimal adverse effects, but researchers are looking up to nanoparticles to improve biodistribution and biocompatibility profile of clinically proven therapeutics. The plethora of conjugation chemistries offered by currently extant inorganic nanoparticles have, in recent years, led to great leaps in the field of biomimicry---a modality that promises high biocompatibility. Further, in the pursuit of highly specific therapeutic molecules, researchers have turned to silencing oligonucleotides and some have already brought together the strengths of nanoparticles and silencing oligonucleotides in search of an efficacious therapy for cancer with minimal adverse effects. This dissertation work focuses on such a biomimetic platform---a gold nanoparticle based high density lipoprotein biomimetic (HDL NP), for the delivery of therapeutic oligonucleotides. The first chapter of this body of work introduces the molecular target of the silencing oligonucleotides---VEGFR2, and its role in the progression of solid tumor cancers. The background information also covers important aspects of natural high density lipoproteins (HDL), especially their innate capacity to bind and deliver exogenous and endogenous silencing oligonucleotides to tissues that express their high affinity receptor SRB1. We subsequently describe the synthesis of the biomimetic HDL NP and its oligonucleotide conjugates, and establish their biocompatibility. Further on, experimental data demonstrate the efficacy of silencing

  18. Rethinking reverse cholesterol transport and dysfunctional high-density lipoproteins.

    Science.gov (United States)

    Gillard, Baiba K; Rosales, Corina; Xu, Bingqing; Gotto, Antonio M; Pownall, Henry J

    2018-04-12

    Human plasma high-density lipoprotein cholesterol concentrations are a negative risk factor for atherosclerosis-linked cardiovascular disease. Pharmacological attempts to reduce atherosclerotic cardiovascular disease by increasing plasma high-density lipoprotein cholesterol have been disappointing so that recent research has shifted from HDL quantity to HDL quality, that is, functional vs dysfunctional HDL. HDL has varying degrees of dysfunction reflected in impaired reverse cholesterol transport (RCT). In the context of atheroprotection, RCT occurs by 2 mechanisms: one is the well-known trans-hepatic pathway comprising macrophage free cholesterol (FC) efflux, which produces early forms of FC-rich nascent HDL (nHDL). Lecithin:cholesterol acyltransferase converts HDL-FC to HDL-cholesteryl ester while converting nHDL from a disc to a mature spherical HDL, which transfers its cholesteryl ester to the hepatic HDL receptor, scavenger receptor B1 for uptake, conversion to bile salts, or transfer to the intestine for excretion. Although widely cited, current evidence suggests that this is a minor pathway and that most HDL-FC and nHDL-FC rapidly transfer directly to the liver independent of lecithin:cholesterol acyltransferase activity. A small fraction of plasma HDL-FC enters the trans-intestinal efflux pathway comprising direct FC transfer to the intestine. SR-B1 -/- mice, which have impaired trans-hepatic FC transport, are characterized by high plasma levels of a dysfunctional FC-rich HDL that increases plasma FC bioavailability in a way that produces whole-body hypercholesterolemia and multiple pathologies. The design of future therapeutic strategies to improve RCT will have to be formulated in the context of these dual RCT mechanisms and the role of FC bioavailability. Copyright © 2018 National Lipid Association. Published by Elsevier Inc. All rights reserved.

  19. Degradation of high density lipoprotein in cultured rat luteal cells

    International Nuclear Information System (INIS)

    Rajan, V.P.; Menon, K.M.J.

    1986-01-01

    In rat ovary luteal cells, degradation of high density lipoprotein (HDL) to tricholoracetic acid (TCA)-soluble products accounts for only a fraction of the HDL-derived cholesterol used for steroidogenesis. In this study the authors have investigated the fate of 125 I]HDL bound to cultured luteal cells using pulse-chase technique. Luteal cell cultures were pulse labeled with [ 125 I]HDL 3 and reincubated in the absence of HDL. By 24 h about 50% of the initallay bound radioactivity was released into the medium, of which 60-65% could be precipitated with 10% TCA. Gel filtration of the chase incubation medium on 10% agarose showed that the amount of TCA-soluble radioactivity was nearly completely accounted for by a sharp peak in the low molecular weight region which was identified as 96% monoiodotyrosine by paper chromatography. The TCA-precipitable radioactivity was nearly completely accounted for by a sharp peak in the low molecular weight region which was identified as 96% monoiodotyrosine by paper chromatography. The TCA-precipitable radioactivity eluted over a wide range of molecular weights (15,000-80,000), and there was very little intact HDL present. Electrophoresis of the chase medium showed that component of the TCA-precipitable portion had mobility similar to apo AI. Lysosomal inhibitors of receptor-mediated endocytosis had no effect on the composition or quantity of radioactivity released during chase incubation. The results show that HDL 3 binding to luteal cells is followed by complete degradation of the lipoprotein, although the TCA-soluble part does not reflect the extent of degradation

  20. Insulin Resistance Predicts Atherogenic Lipoprotein Profile in Nondiabetic Subjects

    Directory of Open Access Journals (Sweden)

    Flávia De C. Cartolano

    2017-01-01

    Full Text Available Background. Atherogenic diabetes is associated with an increased cardiovascular risk and mortality in diabetic individuals; however, the impact of insulin resistance (IR in lipid metabolism in preclinical stages is generally underreported. For that, we evaluated the capacity of IR to predict an atherogenic lipid subfraction profile. Methods. Complete clinical evaluation and biochemical analysis (lipid, glucose profile, LDL, and HDL subfractions and LDL phenotype and size were performed in 181 patients. The impact of IR as a predictor of atherogenic lipoproteins was tested by logistic regression analysis in raw and adjusted models. Results. HDL-C and Apo AI were significantly lower in individuals with IR. Individuals with IR had a higher percentage of small HDL particles, lower percentage in the larger ones, and reduced frequency of phenotype A (IR = 62%; non-IR = 83%. IR individuals had reduced probability to have large HDL (OR = 0.213; CI = 0.999–0.457 and had twice more chances to show increased small HDL (OR = 2.486; CI = 1.341–7.051. IR was a significant predictor of small LDL (OR = 3.075; CI = 1.341–7.051 and atherogenic phenotype (OR = 3.176; CI = 1.469–6.867. Conclusion. IR, previously DM2 diagnosis, is a strong predictor of quantitative and qualitative features of lipoproteins directly associated with an increased atherogenic risk.

  1. Bio F1B hamster: a unique animal model with reduced lipoprotein lipase activity to investigate nutrient mediated regulation of lipoprotein metabolism

    Directory of Open Access Journals (Sweden)

    Cornish Marion L

    2007-12-01

    Full Text Available Abstract Background Bio F1B hamster is an inbred hybrid strain that is highly susceptible to diet-induced atherosclerosis. We previously reported that feeding a high fat fish oil diet to Bio F1B hamster caused severe hyperlipidaemia. In this study we compared the effects of various diets in the Bio F1B hamster and the Golden Syrian hamster, which is an outbred hamster strain to investigate whether genetic background plays an important role in dietary fat mediated regulation of lipoprotein metabolism. We further investigated the mechanisms behind diet-induced hyperlipidaemia in F1B hamster. Methods The Bio F1B and Golden Syrian hamsters, 8 weeks old, were fed high fat diets rich in either monounsaturated fatty acids, an n-6: n-3 ratio of 5 or a fish oil diet for 4 weeks. Animals were fasted overnight and blood and tissue samples were collected. Plasma was fractionated into various lipoprotein fractions and assayed for triacylglycerol and cholesterol concentrations. Plasma lipoprotein lipase activity was measured using radioisotope method. Microsomal triglyceride transfer protein activity was measured in the liver and intestine. Plasma apolipoproteinB48, -B100 and apolipoprotein E was measured using Western blots. Two-way ANOVA was used to determine the effect of diet type and animal strain. Results The fish oil fed F1B hamsters showed milky plasma after a 14-hour fast. Fish oil feeding caused accumulation of apolipoproteinB48 containing lipoprotein particles suggesting hindrance of triglyceride-rich lipoprotein clearance. There was no significant effect of diet or strain on hepatic or intestinal microsomal triglyceride transfer protein activity indicating that hyperlipidaemia is not due to an increase in the assembly or secretion of lipoprotein particles. F1B hamsters showed significantly reduced levels of lipoprotein lipase activity, which was inhibited by fish oil feeding. Conclusion Evidence is presented for the first time that alterations in

  2. Sort1, encoded by the cardiovascular risk locus 1p13.3, is a regulator of hepatic lipoprotein export

    DEFF Research Database (Denmark)

    Kjølby, Mads Fuglsang; Andersen, Olav Michael; Breiderhoff, Tilman

    2010-01-01

    of lipoproteins from the liver and ameliorates hypercholesterolemia and atherosclerotic lesion formation in LDL receptor-deficient animals. In contrast, sortilin overexpression stimulates hepatic release of lipoproteins and increases plasma LDL levels. Our data have uncovered a regulatory pathway in hepatic...... lipoprotein export and suggest a molecular explanation for the cardiovascular risk being associated with 1p13.3. Udgivelsesdato: september 8...

  3. Effects of APOA5 S19W polymorphism on growth, insulin sensitivity and lipoproteins in normoweight neonates

    Science.gov (United States)

    Apolipoprotein (Apo) A5 is a protein involved in the activation of lipoprotein lipase (LPL) and the metabolism of triglyceride (TG)-rich lipoproteins. LPL plays a major role in the metabolism of TG-rich lipoproteins, and placental LPL activity is known to correlate positively with foetal fat deposit...

  4. Influence of impaired lipoprotein biogenesis on surface and exoproteome of Streptococcus pneumoniae.

    Science.gov (United States)

    Pribyl, Thomas; Moche, Martin; Dreisbach, Annette; Bijlsma, Jetta J E; Saleh, Malek; Abdullah, Mohammed R; Hecker, Michael; van Dijl, Jan Maarten; Becher, Dörte; Hammerschmidt, Sven

    2014-02-07

    Surface proteins are important for the fitness and virulence of the Gram-positive pathogen Streptococcus pneumoniae. They are crucial for interaction of the pathogen with its human host during infection. Therefore, the analysis of the pneumococcal surface proteome is an important task that requires powerful tools. In this study, two different methods, an optimized biotinylation approach and shaving with trypsin beads, were applied to study the pneumococcal surface proteome and to identify surface-exposed protein domains, respectively. The identification of nearly 95% of the predicted lipoproteins and 75% of the predicted sortase substrates reflects the high coverage of the two classical surface protein classes accomplished in this study. Furthermore, the biotinylation approach was applied to study the impact of an impaired lipoprotein maturation pathway on the cell envelope proteome and exoproteome. Loss of the lipoprotein diacylglyceryl transferase Lgt leads to striking changes in the lipoprotein distribution. Many lipoproteins disappear from the surface proteome and accumulate in the exoproteome. Further insights into lipoprotein processing in pneumococci are provided by immunoblot analyses of bacterial lysates and corresponding supernatant fractions. Taken together, the first comprehensive overview of the pneumococcal surface and exoproteome is presented, and a model for lipoprotein processing in S. pneumoniae is proposed.

  5. Hepatic apo B-100 lipoproteins and plasma LDL heterogeneity in African green monkeys

    International Nuclear Information System (INIS)

    Murthy, V.N.; Marzetta, C.A.; Rudel, L.L.; Zech, L.A.; Foster, D.M.

    1990-01-01

    The contribution of hepatic apolipoprotein (apo) B-100 lipoproteins to plasma low-density lipoprotein (LDL) metabolic heterogeneity was examined in African green monkeys. Hepatic 3H-labeled very low-density lipoproteins (VLDL) (d less than 1.006, where d is density in g/ml) or hepatic 131I-labeled LDL (1.030 less than d less than 1.063) were isolated from perfused livers and injected simultaneously with autologous plasma 125I-LDL into African green monkeys. Serial blood samples were taken, and the distribution of radioactivity among various subfractions of apo B-100 lipoproteins was determined using density-gradient ultracentrifugation. Compartmental models were developed to describe simultaneously the kinetics of hepatic lipoproteins and plasma LDL. In five of seven studies, the metabolic behavior of LDL derived from radiolabeled hepatic lipoprotein precursors differed from the metabolic behavior of radiolabeled autologous plasma LDL. These differences could be described by different models supporting two hypotheses with different physiological interpretations: (1) lipoproteins of donor and recipient animals are kinetically distinct, and/or (2) plasma LDL derived from various potential sources are kinetically distinct. Compartmental modeling was used to test these hypotheses, which were not accessible to testing by conventional experimental methodologies. The kinetic analyses of these studies suggest that plasma LDL may be derived from a variety of precursors, including hepatic VLDL and hepatic LDL, with each source giving rise to metabolically distinct plasma LDL

  6. Bariatric surgery in morbidly obese patients improves the atherogenic qualitative properties of the plasma lipoproteins.

    Science.gov (United States)

    Julve, Josep; Pardina, Eva; Pérez-Cuéllar, Montserrat; Ferrer, Roser; Rossell, Joana; Baena-Fustegueras, Juan Antonio; Fort, José Manuel; Lecube, Albert; Blanco-Vaca, Francisco; Sánchez-Quesada, José Luis; Peinado-Onsurbe, Julia

    2014-05-01

    The purpose of this study was to evaluate the effect of weight loss induced in morbidly obese subjects by Roux-en-Y gastric bypass bariatric surgery on the atherogenic features of their plasma lipoproteins. Twenty-one morbidly obese subjects undergoing bariatric surgery were followed up for up to 1 year after surgery. Plasma and lipoproteins were assayed for chemical composition and lipoprotein-associated phospholipase A2 (Lp-PLA2) activity. Lipoprotein size was assessed by non-denaturing polyacrylamide gradient gel electrophoresis, and oxidised LDL by ELISA. Liver samples were assayed for mRNA abundance of oxidative markers. Lipid profile analysis revealed a reduction in the plasma concentrations of cholesterol and triglycerides, which were mainly associated with a significant reduction in the plasma concentration of circulating apoB-containing lipoproteins rather than with changes in their relative chemical composition. All patients displayed a pattern A phenotype of LDL subfractions and a relative increase in the antiatherogenic plasma HDL-2 subfraction (>2-fold; P lipoprotein-bound Lp-PLA2. Our data indicate that the weight loss induced by bariatric surgery ameliorates the atherogenicity of plasma lipoproteins by reducing the apoB-containing Lp-PLA2 activity and oxidised LDL, as well as increasing the HDL-2 subfraction. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  7. Membrane receptors for very low density lipoprotein (VLDL) inhibitor of lymphocyte proliferation

    International Nuclear Information System (INIS)

    Yi, P.I.; Beck, G.; Zucker, S.

    1981-01-01

    Physiologic concentrations of human plasma very low density lipoproteins inhibit the DNA synthesis of lymphocytes stimulated by allogeneic cells or lectins. In this report reachers have compared the effects of isolated lipoproteins [very low density lipoproteins (VLDL), low density lipoproteins (LDL), and high density lipoproteins (HDL)] and lipoprotein-depleted plasma (LDP) on DNA synthesis by phytohemagglutinin-stimulated human lymphocytes. The relative potency for the inhibition of lymphocyte proliferation was VLDL greater than LDL greater than HDL greater than LDP. Fifty percent inhibition of DNA synthesis was observed at a VLDL protein concentration of 1.5--2.0 microgram/ml. Researchers have further demonstrated the presence of specific receptors for VLDL on human lymphocytes. Native VLDL was more effective than LDL in competing for 125I-VLDL binding sites. Subsequent to binding to lymphocytes, 125I-VLDL was internalized and degraded to acid-soluble products. Based on a Scatchard analysis of VLDL binding at 4 degrees C, the number of VLDL receptors per lymphocyte was estimated at 28,000 +/- 1300. Based on an estimated mean binding affinity for the VLDL receptor complex at half saturation of approximately 8.8 X 10(7) liter/mole, it is estimated that 91% of lymphocyte VLDL receptors are occupied at physiologic VLDL concentrations in blood. Although the immune regulatory role of plasma lipoproteins is uncertain, researchers suggest tha VLDL and LDL-In may maintain circulating blood lymphocytes in a nonproliferative state via their respective cell receptor mechanisms

  8. The Impact of Cardiorespiratory Fitness on Age-Related Lipids and Lipoproteins

    Science.gov (United States)

    Park, Yong-Moon Mark; Sui, Xuemei; Liu, Junxiu; Zhou, Haiming; Kokkinos, Peter F.; Lavie, Carl J.; Hardin, James W.; Blair, Steven N.

    2015-01-01

    Background Evidence on the effect of cardiorespiratory fitness (CRF) on age-related longitudinal changes of lipids and lipoproteins is scarce. Objectives This study sought to assess the longitudinal, aging trajectory of lipids and lipoproteins for the life course in adults, and to determine whether CRF modifies the age-associated trajectory of lipids and lipoproteins. Methods Data came from 11,418 men, 20 to 90 years of age, without known high cholesterol, high triglycerides, cardiovascular disease, and cancer at baseline and during follow-up from the Aerobics Center Longitudinal Study. There were 43,821 observations spanning 2 to 25 (mean 3.5) health examinations between 1970 and 2006. CRF was quantified by a maximal treadmill exercise test. Marginal models using generalized estimating equations were applied. Results Total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), triglycerides (TG), and non-high-density lipoprotein cholesterol (non-HDL-C) presented similar inverted U-shaped quadratic trajectories with aging: gradual increases were noted until the mid-40s to early 50s, with subsequent declines (all p lipoproteins in young to middle-aged men than in older men. Conclusions Our investigation reveals a differential trajectory of lipids and lipoproteins with aging according to CRF in healthy men, and suggests that promoting increased CRF levels may help delay the development of dyslipidemia. PMID:25975472

  9. Lipoproteins in Drosophila melanogaster—Assembly, Function, and Influence on Tissue Lipid Composition

    Science.gov (United States)

    Palm, Wilhelm; Sampaio, Julio L.; Brankatschk, Marko; Carvalho, Maria; Mahmoud, Ali; Shevchenko, Andrej; Eaton, Suzanne

    2012-01-01

    Interorgan lipid transport occurs via lipoproteins, and altered lipoprotein levels correlate with metabolic disease. However, precisely how lipoproteins affect tissue lipid composition has not been comprehensively analyzed. Here, we identify the major lipoproteins of Drosophila melanogaster and use genetics and mass spectrometry to study their assembly, interorgan trafficking, and influence on tissue lipids. The apoB-family lipoprotein Lipophorin (Lpp) is the major hemolymph lipid carrier. It is produced as a phospholipid-rich particle by the fat body, and its secretion requires Microsomal Triglyceride Transfer Protein (MTP). Lpp acquires sterols and most diacylglycerol (DAG) at the gut via Lipid Transfer Particle (LTP), another fat body-derived apoB-family lipoprotein. The gut, like the fat body, is a lipogenic organ, incorporating both de novo–synthesized and dietary fatty acids into DAG for export. We identify distinct requirements for LTP and Lpp-dependent lipid mobilization in contributing to the neutral and polar lipid composition of the brain and wing imaginal disc. These studies define major routes of interorgan lipid transport in Drosophila and uncover surprising tissue-specific differences in lipoprotein lipid utilization. PMID:22844248

  10. Environment-Mediated Accumulation of Diacyl Lipoproteins over Their Triacyl Counterparts in Staphylococcus aureus

    Science.gov (United States)

    Kurokawa, Kenji; Kim, Min-Su; Ichikawa, Rie; Ryu, Kyoung-Hwa; Dohmae, Naoshi

    2012-01-01

    Bacterial lipoproteins are believed to exist in only one specific lipid-modified structure, such as the diacyl form or the triacyl form, in each bacterium. In the case of Staphylococcus aureus, recent extensive matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) mass spectrometry analysis revealed that S. aureus lipoproteins exist in the α-aminoacylated triacyl form. Here, we discovered conditions that induce the accumulation of diacyl lipoproteins that lack α-aminoacylation in S. aureus. The accumulation of diacyl lipoproteins required a combination of conditions, including acidic pH and a post-logarithmic-growth phase. High temperatures and high salt concentrations additively accelerated the accumulation of the diacyl lipoprotein form. Following a post-logarithmic-growth phase where S. aureus MW2 cells were grown at pH 6, SitC lipoprotein was found almost exclusively in its diacyl structure rather than in its triacyl structure. This is the first report showing that the environment mediates lipid-modified structural alterations of bacterial lipoproteins. PMID:22467779

  11. The effect of cardiorespiratory fitness on age-related lipids and lipoproteins.

    Science.gov (United States)

    Park, Yong-Moon Mark; Sui, Xuemei; Liu, Junxiu; Zhou, Haiming; Kokkinos, Peter F; Lavie, Carl J; Hardin, James W; Blair, Steven N

    2015-05-19

    Evidence on the effect of cardiorespiratory fitness (CRF) on age-related longitudinal changes of lipids and lipoproteins is scarce. This study sought to assess the longitudinal aging trajectory of lipids and lipoproteins for the life course in adults and to determine whether CRF modifies the age-associated trajectory of lipids and lipoproteins. Data came from 11,418 men, 20 to 90 years of age, without known high cholesterol, high triglycerides, cardiovascular disease, and cancer at baseline and during follow-up from the Aerobics Center Longitudinal Study. There were 43,821 observations spanning 2 to 25 health examinations (mean 3.5 examinations) between 1970 and 2006. CRF was quantified by a maximal treadmill exercise test. Marginal models using generalized estimating equations were applied. Total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), triglycerides, and non-high-density lipoprotein cholesterol (non-HDL-C) presented similar inverted U-shaped quadratic trajectories with aging: gradual increases were noted until age mid-40s to early 50s, with subsequent declines (all p lipoproteins in young to middle-age men than in older men. Our investigation reveals a differential trajectory of lipids and lipoproteins with aging according to CRF in healthy men and suggests that promoting increased CRF levels may help delay the development of dyslipidemia. Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  12. Dietary fatty acids were not independently associated with lipoprotein subclasses in elderly women.

    Science.gov (United States)

    Alaghehband, Fatemeh Ramezan; Lankinen, Maria; Värri, Miika; Sirola, Joonas; Kröger, Heikki; Erkkilä, Arja T

    2017-07-01

    Dietary fatty acids are known to affect serum lipoproteins; however, little is known about the associations between consumption of dietary fatty acids and lipoprotein subclasses. In this study, we hypothesized that there is an association between dietary fatty acids and lipoprotein subclasses and investigated the cross-sectional association of dietary fat intake with subclasses of lipoproteins in elderly women. Altogether, 547 women (aged ≥65 years) who were part of OSTPRE cohort participated. Dietary intake was assessed by 3-day food records, lifestyle, and health information obtained through self-administrated questionnaires, and lipoprotein subclasses were determined by nuclear magnetic resonance spectroscopy. To analyze the associations between fatty acids and lipoprotein subclasses, we used Pearson and Spearman correlation coefficients and the analysis of covariance (ANCOVA) test with, adjustment for physical activity, body mass index, age, smoking status, and intake of lipid-lowering drugs. There were significant correlations between saturated fatty acids (SFA; % of energy) and concentrations of large, medium, and small low-density lipoproteins (LDL); total cholesterol in large, medium, and small LDL; and phospholipids in large, medium, and small LDL, after correction for multiple testing. After adjustment for covariates, the higher intake of SFA was associated with smaller size of LDL particles (P = .04, ANCOVA) and lower amount of triglycerides in small very low-density lipoproteins (P = .046, ANCOVA). However, these associations did not remain significant after correction for multiple testing. In conclusion, high intake of SFA may be associated with the size of LDL particles, but the results do not support significant, independent associations between dietary fatty acids and lipoprotein subclasses. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Characteristics of 2,4,5,2',4',5'-hexachlorobiphenyl distribution among lipoproteins in vitro

    International Nuclear Information System (INIS)

    Vomachka, M.S.; Vodicnik, M.J.; Lech, J.J.

    1983-01-01

    The uptake, distribution, and transfer of 2,4,5,2',4',5'-hexachlorobiphenyl (6-CB) were examined in vitro with human and rat whole blood, plasma, and lipoprotein fractions. 6-CB distribution between plasma and erythrocytes as well as among lipoproteins was determined following sedimentation of erythrocytes and ultracentrifugal fractionation of plasma. In both rat and human whole blood, 70 to 75% of 6-CB partitioned into plasma and 25 to 30% into erythrocytes. The uptake of 6-CB into plasma was extremely rapid and the rate of uptake was found to be dependent upon temperature. The distribution of 6-CB among lipoproteins was relatively homogeneous with 20 to 30% being distributed in very low-density lipoproteins (VLDL, d . 0.95-1.006 g/ml), 15 to 20% in low-density lipoproteins (LDL, d . 1.006-1.063 g/ml), and 15 to 25% in high-density lipoproteins (HDL, d . 1.063-1.21 g/ml). Over 25% of 6-CB was found in the remaining bottom fraction. In addition, each isolated fraction when incubated alone with 6-CB was shown capable of uptake. The relative proportion of 6-CB among the lipoproteins was independent of the level taken up by plasma. 6-CB was also found to transfer among lipoproteins. This exchange of 6-CB proved to be dependent upon the concentrations of both protein and triacylglycerol in the incubations. Two proteins in the bottom fraction (Bf), albumin and a steroid binding globulin, were capable of competing with the lipoproteins for 6-CB uptake

  14. Recurrent Embolic Strokes of Undetermined Source in a Patient with Extreme Lipoprotein(a Levels

    Directory of Open Access Journals (Sweden)

    Zachary Bulwa

    2016-08-01

    Full Text Available Lipoprotein(a is a plasma lipoprotein and known cardiovascular risk factor most recently implicated in the development of high-risk carotid atherosclerotic plaques without significant carotid stenosis. We present a case of a young African-American female with recurrent embolic strokes of undetermined source. After our thorough investigation we identified the link between a small, irregular plaque in the right internal carotid artery and an extremely elevated plasma level of lipoprotein(a as the source of her embolic strokes.

  15. Extreme lipoprotein(a) levels and risk of myocardial infarction in the general population

    DEFF Research Database (Denmark)

    Kamstrup, Pia R; Benn, Marianne; Tybjaerg-Hansen, Anne

    2008-01-01

    Elevated lipoprotein(a) levels are associated with myocardial infarction (MI) in some but not all studies. Limitations of previous studies include lack of risk estimates for extreme lipoprotein(a) levels, measurements in long-term frozen samples, no correction for regression dilution bias, and lack...... of absolute risk estimates in the general population. We tested the hypothesis that extreme lipoprotein(a) levels predict MI in the general population, measuring levels shortly after sampling, correcting for regression dilution bias, and calculating hazard ratios and absolute risk estimates....

  16. Secretion of bacterial lipoproteins: through the cytoplasmic membrane, the periplasm and beyond.

    Science.gov (United States)

    Zückert, Wolfram R

    2014-08-01

    Bacterial lipoproteins are peripherally anchored membrane proteins that play a variety of roles in bacterial physiology and virulence in monoderm (single membrane-enveloped, e.g., gram-positive) and diderm (double membrane-enveloped, e.g., gram-negative) bacteria. After export of prolipoproteins through the cytoplasmic membrane, which occurs predominantly but not exclusively via the general secretory or Sec pathway, the proteins are lipid-modified at the cytoplasmic membrane in a multistep process that involves sequential modification of a cysteine residue and cleavage of the signal peptide by the signal II peptidase Lsp. In both monoderms and diderms, signal peptide processing is preceded by acylation with a diacylglycerol through preprolipoprotein diacylglycerol transferase (Lgt). In diderms but also some monoderms, lipoproteins are further modified with a third acyl chain through lipoprotein N-acyl transferase (Lnt). Fully modified lipoproteins that are destined to be anchored in the inner leaflet of the outer membrane (OM) are selected, transported and inserted by the Lol (lipoprotein outer membrane localization) pathway machinery, which consists of the inner-membrane (IM) ABC transporter-like LolCDE complex, the periplasmic LolA chaperone and the OM LolB lipoprotein receptor. Retention of lipoproteins in the cytoplasmic membrane results from Lol avoidance signals that were originally described as the "+2 rule". Surface localization of lipoproteins in diderms is rare in most bacteria, with the exception of several spirochetal species. Type 2 (T2SS) and type 5 (T5SS) secretion systems are involved in secretion of specific surface lipoproteins of γ-proteobacteria. In the model spirochete Borrelia burgdorferi, surface lipoprotein secretion does not follow established sorting rules, but remains dependent on N-terminal peptide sequences. Secretion through the outer membrane requires maintenance of lipoproteins in a translocation-competent unfolded conformation

  17. Role of adipocyte-derived lipoprotein lipase in adipocyte hypertrophy

    Directory of Open Access Journals (Sweden)

    Orlando Robert A

    2007-10-01

    Full Text Available Abstract Background A major portion of available fatty acids for adipocyte uptake is derived from lipoprotein lipase (LPL-mediated hydrolysis of circulating lipoprotein particles. In vivo studies aimed at identifying the precise role of adipocyte-derived LPL in fat storage function of adipose tissue have been unable to provide conclusive evidence due to compensatory mechanisms that activate endogenous fatty acid synthesis. To address this gap in knowledge, we have measured the effect of reducing adipocyte LPL expression on intracellular lipid accumulation using a well-established cultured model of adipocyte differentiation. Methods siRNA specific for mouse LPL was transfected into 3T3-L1 adipocytes. Expression of LPL was measured by quantitative real-time PCR and cell surface-associated LPL enzymatic activity was measured by colorimetric detection following substrate (p-nitrophenyl butyrate hydrolysis. Apolipoprotein CII and CIII expression ratios were also measured by qRT-PCR. Intracellular lipid accumulation was quantified by Nile Red staining. Results During differentiation of 3T3-L1 pre-adipocytes, LPL mRNA expression increases 6-fold resulting in a 2-fold increase in cell surface-associated LPL enzymatic activity. Parallel to this increase in LPL expression, we found that intracellular lipids increased ~10-fold demonstrating a direct correlation between adipocyte-derived LPL expression and lipid storage. We next reduced LPL expression in adipocytes using siRNA transfections to directly quantify the contributions of adipocyte-derived LPL to lipid storage, This treatment reduced LPL mRNA expression and cell surface-associated LPL enzymatic activity to ~50% of non-treated controls while intracellular lipid levels were reduced by 80%. Exogenous addition of purified LPL (to restore extracellular lipolytic activity or palmitate (as a source of free fatty acids to siRNA-treated cells restored intracellular lipid levels to those measured for non

  18. Modification of low-density lipoprotein by different radioiodination methods

    International Nuclear Information System (INIS)

    Sobal, G.; Resch, U.; Sinzinger, H.

    2004-01-01

    Scintigraphic imaging of radiolabeled low-density lipoproteins (LDL) is an interesting tool for the understanding of its role in pathomechanism of atherosclerosis. Metabolism of native LDL shows quite different pattern and kinetics as compared to that of modified LDL which is not mediated by classical LDL-receptor and accumulates in atherosclerotic lesions to form lipid-laden foam cells. Therefore we were interested whether radiolabelling of LDL induces structural modifications. We performed the iodine labeling of LDL for scintigraphic imaging of atherosclerosis by three different methods: chloramine-T (A), iodine monochloride (B) and iodogen (C). The highest radiolabelling yield of 125 I was obtained by the iodogen method (75.44±13.52%) and the lowest (49.01±12.74%) by iodine monochloride. Chloramine T showed a labeling yield of 62.82±6.17%. The stability of the tracer was very high with all the methods, persisting up to 6 h (98.83±1.2% - 91.38±4.7%, 15 min vs 6 h after labeling). For the first time we not only investigated the influence of radiolabelling on relative electrophoretic mobility (REM), but also various oxidation parameters such as baseline dienes (BD), thiobarbituric acid reactive substances (TBARS), endogenous peroxides (POX) and oxidation resistance in the copper-mediated oxidation system (expressed as lag-time) were measured. Furthermore, oxidation- derived fragmentation of the lipoproteins was examined with SDS-PAGE electrophoresis. Data are expressed as % change compared to native LDL before radiolabeling. BD were reduced by 32% using the method (A), but increased by 33% and 47% with the monochloride (B) and iodogen method (C), respectively. The effect on lag-time was comparable for all the three methods, ranging from 25 to 36% reduction in lag-time. TBARS were strongly increased 5-7 fold by all the methods. REM was changed by all three methods. While by methods A and C we have found a moderate increase in REM by 1.75 and 2.0 fold

  19. Evaluation of serum lipids and lipoproteins as prognosticators in leukoplakia.

    Science.gov (United States)

    Ganavi, B S; Patil, Shankargouda; Rao, Roopa S

    2014-05-01

    Oral cancer is the 8th most common cancer worldwide. Squamous cell carcinomas constitute 94% of all oral malignancies and are often preceded by leukoplakia. Despite many adjunctive techniques to monitor transformation of leukoplakia to oral squamous cell carcinoma (OSCC), the mortality rate is on the rise. Incidentally, patients diagnosed with oral potentially malignant disorders (OPMDs) and oral cancers manifest with low choles-terol levels. Given a thought, hypolipidemia may be a useful adjunctive tool as it reflects the initial changes within the neo-plastic cells, thus giving a red alert in malignant transformation of leukoplakia at the earlier stage. To evaluate the feasibility of serum lipid profile as an adjunct early marker for malignant transformation of leukoplakia to OSCC. To estimate the serum cholesterol, triglycerides and lipoprotein (HDL, LDL, VLDL) levels in patients with leukoplakia, OSCC and age matched healthy control group. To compare the serum cholesterol, triglycerides and lipoprotein levels between patients of leukoplakia, OSCC and age matched healthy control group. The study group comprised of selected 30 individuals which included 10 each of histopathologically confirmed OSCC, leukoplakia and healthy controls. A written consent was taken from all of them, and a thorough case history was recorded and then venous blood was collected 12 hours post fasting and centrifuged. The serum cholesterol, triglycerides and HDL were estimated by enzymatic and colorimetric methods using commercially available kits--Roche/ Hitachi cobas systems. Chemistry assay QC procured from Bio-Rad was used as control. VLDL and LDL were derived from these values. Results were statistically analyzed using ANOVA and post hoc Tukey Test. Oral squamous cell carcinoma patients demonstrated significantly lower mean serum cholesterol level (151.60 mg/dl) than the control group (183.70 mg/dl). The mean cholesterol level in leukoplakia patients (173.90 mg/dl) was lower than that

  20. First WHO/IFCC International Reference Reagent for Lipoprotein(a) for Immunoassay--Lp(a) SRM 2B.

    Science.gov (United States)

    Dati, Francesco; Tate, Jillian R; Marcovina, Santica M; Steinmetz, Armin

    2004-01-01

    Lipoprotein(a) is an important predictor of cardiovascular disease risk. The lack of internationally accepted standardization has impeded the broad application of this lipoprotein in laboratory medicine. The International Federation of Clinical Chemistry and Laboratory Medicine (IFCC), through its Working Group on Lipoprotein(a) and together with research institutions and several diagnostic companies, have succeeded in developing an international reference material that is intended for the transfer of a lipoprotein(a) concentration to manufacturers' master calibrators. IFCC SRM 2B has recently been accepted by the WHO Expert Committee on Biological Standardization as the 'First WHO/IFCC International Reference Reagent for Lipoprotein(a) for Immunoassay'. The assigned unitage of 0.1071 nanomoles of lipoprotein(a) per vial is traceable to the consensus reference method for lipoprotein(a) and will enable conformity by diagnostic companies to the European Union's Directive on In vitro Diagnostic Medical Devices for the metrological traceability of calibrator materials.

  1. Low fasting low high-density lipoprotein and postprandial lipemia

    Directory of Open Access Journals (Sweden)

    Sorodila Konstandina

    2004-07-01

    Full Text Available Abstract Background Low levels of high density lipoprotein (HDL cholesterol and disturbed postprandial lipemia are associated with coronary heart disease. In the present study, we evaluated the variation of triglyceride (TG postprandially in respect to serum HDL cholesterol levels. Results Fifty two Greek men were divided into 2 main groups: a the low HDL group (HDL p = 0.002. The low HDL group had significantly higher TG at 4, 6 and 8 h postprandially compared to the controls (p = 0.006, p = 0.002, and p p = 0.017 compared to the matched-control group. ROC analysis showed that fasting TG ≥ 121 mg/dl have 100% sensitivity and 81% specificity for an abnormal TG response (auc = 0.962, p Conclusions The delayed TG clearance postprandially seems to result in low HDL cholesterol even in subjects with low fasting TG. The fasting TG > 121 mg/dl are predictable for abnormal response to fatty meal.

  2. Lipoprotein(a) and risk of type 2 diabetes

    DEFF Research Database (Denmark)

    Mora, Samia; Kamstrup, Pia R; Rifai, Nader

    2010-01-01

    BACKGROUND: Previous studies have demonstrated that cardiovascular risk is higher with increased lipoprotein (a) [Lp(a)]. Whether Lp(a) concentration is related to type 2 diabetes is unclear. METHODS: In 26 746 healthy US women (mean age 54.6 years), we prospectively examined baseline Lp......(a) concentrations and incident type 2 diabetes (n = 1670) for a follow-up period of 13 years. We confirmed our findings in 9652 Danish men and women with prevalent diabetes (n = 419). Analyses were adjusted for risk factors that included age, race, smoking, hormone use, family history, blood pressure, body mass...... index, hemoglobin A(1c) (Hb A(1c)), C-reactive protein, and lipids. RESULTS: Lp(a) was inversely associated with incident diabetes, with fully adjusted hazard ratios (HRs) and 95% CIs for quintiles 2-5 vs quintile 1 of 0.87 (0.75-1.01), 0.80 (0.68-0.93), 0.88 (0.76-1.02), and 0.78 (0.67-0.91); P...

  3. High Density Lipoprotein: A Therapeutic Target in Type 2 Diabetes

    Directory of Open Access Journals (Sweden)

    Philip J. Barter

    2013-09-01

    Full Text Available High density lipoproteins (HDLs have a number of properties that have the potential to inhibit the development of atherosclerosis and thus reduce the risk of having a cardiovascular event. These protective effects of HDLs may be reduced in patients with type 2 diabetes, a condition in which the concentration of HDL cholesterol is frequently low. In addition to their potential cardioprotective properties, HDLs also increase the uptake of glucose by skeletal muscle and stimulate the synthesis and secretion of insulin from pancreatic β cells and may thus have a beneficial effect on glycemic control. This raises the possibility that a low HDL concentration in type 2 diabetes may contribute to a worsening of diabetic control. Thus, there is a double case for targeting HDLs in patients with type 2 diabetes: to reduce cardiovascular risk and also to improve glycemic control. Approaches to raising HDL levels include lifestyle factors such as weight reduction, increased physical activity and stopping smoking. There is an ongoing search for HDL-raising drugs as agents to use in patients with type 2 diabetes in whom the HDL level remains low despite lifestyle interventions.

  4. [Plasma lipoproteins as drug carriers. Effect of phospholipid formulations].

    Science.gov (United States)

    Torkhovskaia, T I; Ipatova, O M; Medvedeva, N V; Ivanov, V S; Ivanova, L I

    2010-01-01

    The extensive development of nanotechnologies in the last two decades has brought about new understanding of plasma lipoproteins (LP) as natural drug nanocarriers that escape interaction with immune and reticuloendothelial systems. Drugs bound to LP (especially LDL) can more actively penetrate into cells of many cancer and inflammation tissues with enhanced expression or/and dysregulation of B,E receptors or possibly scavenger SR-BI receptors. Relevant studies are focused on the development of new dosage forms by conjugating lipophilic drugs either with isolated plasma LP or with their model formulations, such as nanoemulsions, mimetics, lipid nanospheres, etc. Some authors include in these particles serum or recombinant apoproteins, peptides, and modified polymer products. As shown recently, protein-free lipid nanoemulsions in plasma take up free apoA and apoE. Complexes with various LP also form after direct administration of lypophilic drugs into blood especially those enclosed in phospholipid formulations, e.g. liposomes. Results of evaluation of some lipophilic dugs (mainly cytostatics, amphotericin B, cyclosporine A, etc.) are discussed. Original data are presented on the influence of phospholipid formulations on the distribution of doxorubicin and indomethacin between LP classes after in vitro incubation in plasma. On the whole, the review illustrates the importance of research on LP and phospholi pid forms as drug nanocarriers to be used to enhance effect of therapy.

  5. Lipoprotein(a: Cellular Effects and Molecular Mechanisms

    Directory of Open Access Journals (Sweden)

    Kirsten Riches

    2012-01-01

    Full Text Available Lipoprotein(a (Lp(a is an independent risk factor for the development of cardiovascular disease (CVD. Indeed, individuals with plasma concentrations >20 mg/dL carry a 2-fold increased risk of developing CVD, accounting for ~25% of the population. Circulating levels of Lp(a are remarkably resistant to common lipid lowering therapies, and there are currently no robust treatments available for reduction of Lp(a apart from plasma apheresis, which is costly and labour intensive. The Lp(a molecule is composed of two parts, an LDL/apoB-100 core and a unique glycoprotein, apolipoprotein(a (apo(a, both of which can interact with components of the coagulation cascade, inflammatory pathways, and cells of the blood vessel wall (smooth muscle cells (SMC and endothelial cells (EC. Therefore, it is of key importance to determine the molecular pathways by which Lp(a exerts its influence on the vascular system in order to design therapeutics to target its cellular effects. This paper will summarise the role of Lp(a in modulating cell behaviour in all aspects of the vascular system including platelets, monocytes, SMC, and EC.

  6. Metabolic fate of rat heart endothelial lipoprotein lipase

    International Nuclear Information System (INIS)

    Chajek-Shaul, T.; Bengtsson-Olivecrona, G.; Peterson, J.; Olivecrona, T.

    1988-01-01

    When isolated rat hearts were perfused with medium containing 125I-labeled bovine lipoprotein lipase (LPL), they bound both lipase activity and radioactivity. More than 80% of the bound lipase could be rapidly released by heparin. Low concentrations of bovine LPL displaced 50-60% of the endogeneous, endothelial-bound LPL. Higher concentrations caused additional binding. Both binding and exchange were rapid processes. The hearts continuously released endogenous LPL into the medium. An antiserum that inhibited bovine but not rat LPL was used to differentiate endogeneous and exogeneous LPL activity. When the pool of endothelial LPL was labeled with bovine 125I-labeled LPL and then chased with unlabeled bovine LPL, approximately 50% of the labeled lipase was rapidly displaced. During chase perfusion with medium only, catalytically active bovine LPL appeared in the perfusate. The rate of release was similar to that observed for endogeneous LPL activity and amounted to 10-13% of the heparin-releasable fraction in the first 5 min of perfusion. There was little or no degradation of bovine 125I-labeled LPL to fragments or acid-soluble products. These results indicate that endothelial LPL is accessible for exchange with exogeneous LPL and that detachment rather than degradation may be the pathway for catabolism of endothelial LPL

  7. Hemorheological abnormalities in lipoprotein lipase deficient mice with severe hypertriglyceridemia

    International Nuclear Information System (INIS)

    Zhao Tieqiang; Guo Jun; Li Hui; Huang Wei; Xian Xunde; Ross, Colin J.D.; Hayden, Michael R.; Wen Zongyao; Liu George

    2006-01-01

    Severe hypertriglyceridemia (HTG) is a metabolic disturbance often seen in clinical practice. It is known to induce life-threatening acute pancreatitis, but its role in atherogenesis remains elusive. Hemorheological abnormality was thought to play an important role in pathogenesis of both pancreatitis and atherosclerosis. However, hemorheology in severe HTG was not well investigated. Recently, we established a severe HTG mouse model deficient in lipoprotein lipase (LPL) in which severe HTG was observed to cause a significant increase in plasma viscosity. Disturbances of erythrocytes were also documented, including decreased deformability, electrophoresis rate, and membrane fluidity, and increased osmotic fragility. Scanning electron microscopy demonstrated that most erythrocytes of LPL deficient mice deformed with protrusions, irregular appearances or indistinct concaves. Analysis of erythrocyte membrane lipids showed decreased cholesterol (Ch) and phospholipid (PL) contents but unaltered Ch/PL ratio. The changes of membrane lipids may be partially responsible for the hemorheological and morphologic abnormalities of erythrocytes. This study indicated that severe HTG could lead to significant impairment of hemorheology and this model may be useful in delineating the role of severe HTG in the pathogenesis of hyperlipidemic pancreatitis and atherosclerosis

  8. Acrolein impairs the cholesterol transport functions of high density lipoproteins.

    Science.gov (United States)

    Chadwick, Alexandra C; Holme, Rebecca L; Chen, Yiliang; Thomas, Michael J; Sorci-Thomas, Mary G; Silverstein, Roy L; Pritchard, Kirkwood A; Sahoo, Daisy

    2015-01-01

    High density lipoproteins (HDL) are considered athero-protective, primarily due to their role in reverse cholesterol transport, where they transport cholesterol from peripheral tissues to the liver for excretion. The current study was designed to determine the impact of HDL modification by acrolein, a highly reactive aldehyde found in high abundance in cigarette smoke, on the cholesterol transport functions of HDL. HDL was chemically-modified with acrolein and immunoblot and mass spectrometry analyses confirmed apolipoprotein crosslinking, as well as acrolein adducts on apolipoproteins A-I and A-II. The ability of acrolein-modified HDL (acro-HDL) to serve as an acceptor of free cholesterol (FC) from COS-7 cells transiently expressing SR-BI was significantly decreased. Further, in contrast to native HDL, acro-HDL promotes higher neutral lipid accumulation in murine macrophages as judged by Oil Red O staining. The ability of acro-HDL to mediate efficient selective uptake of HDL-cholesteryl esters (CE) into SR-BI-expressing cells was reduced compared to native HDL. Together, the findings from our studies suggest that acrolein modification of HDL produces a dysfunctional particle that may ultimately promote atherogenesis by impairing functions that are critical in the reverse cholesterol transport pathway.

  9. Adropin induction of lipoprotein lipase expression in tilapia hepatocytes.

    Science.gov (United States)

    Lian, Anji; Wu, Keqiang; Liu, Tianqiang; Jiang, Nan; Jiang, Quan

    2016-01-01

    The peptide hormone adropin plays a role in energy homeostasis. However, biological actions of adropin in non-mammalian species are still lacking. Using tilapia as a model, we examined the role of adropin in lipoprotein lipase (LPL) regulation in hepatocytes. To this end, the structural identity of tilapia adropin was established by 5'/3'-rapid amplification of cDNA ends (RACE). The transcripts of tilapia adropin were ubiquitously expressed in various tissues with the highest levels in the liver and hypothalamus. The prolonged fasting could elevate tilapia hepatic adropin gene expression, whereas no effect of fasting was observed on hypothalamic adropin gene levels. In primary cultures of tilapia hepatocytes, synthetic adropin was effective in stimulating LPL release, cellular LPL content, and total LPL production. The increase in LPL production also occurred with parallel rises in LPL gene levels. In parallel experiments, adropin could elevate cAMP production and up-regulate protein kinase A (PKA) and PKC activities. Using a pharmacological approach, cAMP/PKA and PLC/inositol trisphosphate (IP3)/PKC cascades were shown to be involved in adropin-stimulated LPL gene expression. Parallel inhibition of p38MAPK and Erk1/2, however, were not effective in these regards. Our findings provide, for the first time, evidence that adropin could stimulate LPL gene expression via direct actions in tilapia hepatocytes through the activation of multiple signaling mechanisms. © 2016 Society for Endocrinology.

  10. Escherichia coli lipoprotein binds human plasminogen via an intramolecular domain

    Directory of Open Access Journals (Sweden)

    Tammy eGonzalez

    2015-10-01

    Full Text Available Escherichia coli lipoprotein (Lpp is a major cellular component that exists in two distinct states, bound-form and free-form. Bound-form Lpp is known to interact with the periplasmic bacterial cell wall, while free-form Lpp is localized to the bacterial cell surface. A function for surface-exposed Lpp has yet to be determined. We hypothesized that the presence of C-terminal lysines in the surface-exposed region of Lpp would facilitate binding to the host zymogen plasminogen, a protease commandeered by a number of clinically important bacteria. Recombinant Lpp was synthesized and the binding of Lpp to plasminogen, the effect of various inhibitors on this binding, and the effects of various mutations of Lpp on Lpp-plasminogen interactions were examined. Additionally, the ability of Lpp-bound plasminogen to be converted to active plasmin was analyzed. We determined that Lpp binds plasminogen via an atypical domain located near the center of mature Lpp that may not be exposed on the surface of intact E. coli according to the current localization model. Finally, we found that plasminogen bound by Lpp can be converted to active plasmin. While the consequences of Lpp binding plasminogen are unclear, these results prompt further investigation of the ability of surface exposed Lpp to interact with host molecules such as extracellular matrix components and complement regulators, and the role of these interactions in infections caused by E. coli and other bacteria.

  11. Lipoprotein(a) and risk of type 2 diabetes

    DEFF Research Database (Denmark)

    Mora, S.; Kamstrup, Pia R; Rifai, N.

    2010-01-01

    (a) concentrations and incident type 2 diabetes (n = 1670) for a follow-up period of 13 years. We confirmed our findings in 9652 Danish men and women with prevalent diabetes (n = 419). Analyses were adjusted for risk factors that included age, race, smoking, hormone use, family history, blood pressure, body mass......BACKGROUND: Previous studies have demonstrated that cardiovascular risk is higher with increased lipoprotein (a) [Lp(a)]. Whether Lp(a) concentration is related to type 2 diabetes is unclear. METHODS: In 26 746 healthy US women (mean age 54.6 years), we prospectively examined baseline Lp...... index, hemoglobin A(1c) (Hb A(1c)), C-reactive protein, and lipids. RESULTS: Lp(a) was inversely associated with incident diabetes, with fully adjusted hazard ratios (HRs) and 95% CIs for quintiles 2-5 vs quintile 1 of 0.87 (0.75-1.01), 0.80 (0.68-0.93), 0.88 (0.76-1.02), and 0.78 (0.67-0.91); P...

  12. Improving lipoprotein profiles by liver-directed gene transfer of low ...

    Indian Academy of Sciences (India)

    cesses, where a myriad of proteins necessary for metabolism and immune .... containing 5% nonfat milk for several hours, the membrane .... high-density lipoprotein cholesterol; mice were fed with a high fat diet (21% fat, 0.15% choles- terol).

  13. Altered Serum Lipoprotein Profiles in Male and Female Power Lifters Ingesting Anabolic Steroids.

    Science.gov (United States)

    Cohen, Jonathan C.; And Others

    1986-01-01

    Serum lipoprotein profiles were measured in nine male and three female weightlifters who were taking anabolic steroids. The profiles suggest that steriod users may face an increased risk of coronary artery disease. (Author/MT)

  14. Assessing the functional properties of high-density lipoproteins : an emerging concept in cardiovascular research

    NARCIS (Netherlands)

    Triolo, Michela; Annema, Wijtske; Dullaart, Robin P. F.; Tietge, Uwe J. F.

    Although plasma concentrations of high-density lipoprotein (HDL) cholesterol correlate inversely with the incidence of atherosclerotic cardiovascular disease, results from recent epidemiological, genetic and pharmacological intervention studies resulted in a shift of concept. Rather than HDL

  15. Moderate doses of alcoholic beverages with dinner and postprandial high density lipoprotein composition

    NARCIS (Netherlands)

    Hendriks, H.F.J.; Veenstra, J.; Tol, A. van; Groener, J.E.M.; Schaafsma, G.

    1998-01-01

    Moderate alcohol consumption is associated with a reduced risk of coronary heart disease. In this study, postprandial changes in plasma lipids, high-density lipoprotein (HDL) composition and cholesteryl ester transfer protein (CETP) and lecithin: cholesterol acyltransferase (LCAT) activity levels

  16. High lipoprotein(a) as a possible cause of clinical familial hypercholesterolaemia

    DEFF Research Database (Denmark)

    Langsted, Anne; Kamstrup, Pia Rørbœk; Benn, Marianne

    2016-01-01

    , and that individuals with both high lipoprotein(a) concentrations and clinical familial hypercholesterolaemia have the highest risk of myocardial infarction. METHODS: We did a prospective cohort study that included data from 46 200 individuals from the Copenhagen General Population Study who had lipoprotein...... cholesterol, mean lipoprotein(a) concentrations were 23 mg/dL in individuals unlikely to have familial hypercholesterolaemia, 32 mg/dL in those with possible familial hypercholesterolaemia, and 35 mg/dL in those with probable or definite familial hypercholesterolaemia (ptrend... LDL cholesterol for lipoprotein(a) cholesterol content the corresponding values were 24 mg/dL for individuals unlikely to have familial hypercholesterolaemia, 22 mg/dL for those with possible familial hypercholesterolaemia, and 21 mg/dL for those with probable or definite familial...

  17. Metabolic activity of boar semen stored in different extenders supplemented with ostrich egg yolk lipoproteins

    OpenAIRE

    Dziekońska Anna; Kinder Marek; Fraser Leyland; Strzeżek Jerzy; Kordan Władysław

    2017-01-01

    Introduction: The aim of this study was to evaluate the effect of lipoprotein fraction isolated from ostrich egg yolk (LPFo) on the metabolic activity of boar spermatozoa following liquid semen storage in different extenders and temperatures.

  18. Metabolic activity of boar semen stored in different extenders supplemented with ostrich egg yolk lipoproteins

    Directory of Open Access Journals (Sweden)

    Dziekońska Anna

    2017-03-01

    Full Text Available Introduction: The aim of this study was to evaluate the effect of lipoprotein fraction isolated from ostrich egg yolk (LPFo on the metabolic activity of boar spermatozoa following liquid semen storage in different extenders and temperatures.

  19. Behavioral versus genetic determination of lipoproteins andidentical twins discordant for exercise

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Paul T.; Blanche, Patricia J.; Krauss, Ronald M.

    2004-06-01

    Lipoprotein and weight differences between vigorously active and sedentary MZ twins are used to: (1) estimate the effects of training while controlling for genotype; (2) estimate genetic concordance in the presence of divergent lifestyles.

  20. An alternative procedure for incorporating radiolabelled cholesteryl ester into human plasma lipoproteins in vitro

    International Nuclear Information System (INIS)

    Roberts, D.C.K.; Miller, N.E.; Price, S.G.L.; Crook, D.; Cortese, C.; Ville, A. La; Masana, L.; Lewis, B.

    1985-01-01

    A simple method has been developed for labelling human plasma lipoproteins to high specific radioactivity with radioactive cholesteryl esters in vitro. After isolation by preparative ultracentrifugation, the selected lipoprotein was incubated for 30 min at 4 0 C in human serum (d > 1.215) that had been prelabelled with [4- 14 C]cholesteryl oleate or [1,2- 3 H]cholesteryl linoleate, and was then re-isolated by ultracentrifugation. All major lipoprotein classes were labelled by the procedure. Specific radioactivities of up to 18 d.p.m. .pmol -1 (46d.p.m. .ng -1 ) were achieved. When radiolabelled high-density lipoprotein was infused intravenously, the radioactive cholesteryl ester behaved in vivo indistinguishably from endogenous cholesteryl esters produced by the lecithin (phosphatidylcholine): cholesterol acyltransferase reaction. (author)

  1. Binding of digitoxin and digoxin to normal human β-lipoproteins

    International Nuclear Information System (INIS)

    Brock, A.

    1976-01-01

    The binding of digitoxin and digoxin to purified β-lipoprotein, obtained from pooled normal human serum, was studied under equilibrium conditions. Even with as high concentrations of unbound digitoxin or digoxin as 4 μmol/l, the preparations of β-lipoproteins, containing cholesterol 1.98-3.95 mmol/l, showed no signs of saturation. The binding affinity of digitoxin was about ten times as high as that of digoxin. Gel filtration chromatography, performed on native serum after addition of 3 H-digitoxin or 3 H-digoxin, showed a minor fraction of the cardiac glycosides to be associated with te protein fraction of highest molecular weight. This phenomenon disappeared after precipitation of the β-lipoproteins. In clinical relations the contribution of protein-bound digitoxin caused by the lipoprotein interaction is immaterial compared to that caused by the albumin interaction. (author)

  2. Association of mitotane with chylomicrons and serum lipoproteins: practical implications for treatment of adrenocortical carcinoma.

    Science.gov (United States)

    Kroiss, Matthias; Plonné, Dietmar; Kendl, Sabine; Schirmer, Diana; Ronchi, Cristina L; Schirbel, Andreas; Zink, Martina; Lapa, Constantin; Klinker, Hartwig; Fassnacht, Martin; Heinz, Werner; Sbiera, Silviu

    2016-03-01

    Oral mitotane (o,p'-DDD) is a cornerstone of medical treatment for adrenocortical carcinoma (ACC). Serum mitotane concentrations >14  mg/l are targeted for improved efficacy but not achieved in about half of patients. Here we aimed at a better understanding of intestinal absorption and lipoprotein association of mitotane and metabolites o,p'-dichlorodiphenylacetic acid (o,p'-DDA) and o,p'-dichlorodiphenyldichloroethane (o,p'-DDE). Lipoproteins were isolated by ultracentrifugation from the chyle of a 29-year-old patient and serum from additional 14 ACC patients treated with mitotane. HPLC was applied for quantification of mitotane and metabolites. We assessed NCI-H295 cell viability, cortisol production, and expression of endoplasmic reticulum (ER) stress marker genes to study the functional consequences of mitotane binding to lipoproteins. Chyle of the index patient contained 197  mg/ml mitotane, 53  mg/ml o,p'-DDA, and 51  mg/l o,p'-DDE. Of the total mitotane in serum, lipoprotein fractions contained 21.7±21.4% (VLDL), 1.9±0.8% (IDL), 8.9±5.5% (LDL1), 18.9±9.6% (LDL2), 10.1±4.0% (LDL3), and 26.3±13.0% (HDL2). Only 12.3±5.5% were in the lipoprotein-depleted fraction. Mitotane content of lipoproteins directly correlated with their triglyceride and cholesterol content. O,p'-DDE was similarly distributed, but 87.9±4.2% of o,p'-DDA found in the HDL2 and lipoprotein-depleted fractions. Binding of mitotane to human lipoproteins blunted its anti-proliferative and anti-hormonal effects on NCI-H295 cells and reduced ER stress marker gene expression. Mitotane absorption involves chylomicron binding. High concentrations of o,p'-DDA and o,p'-DDE in chyle suggest intestinal mitotane metabolism. In serum, the majority of mitotane is bound to lipoproteins. In vitro, lipoprotein binding inhibits activity of mitotane suggesting that lipoprotein-free mitotane is the therapeutically active fraction. © 2016 European Society of Endocrinology.

  3. Atorvastatin decreases apolipoprotein C-III in apolipoprotein B-containing lipoprotein and HDL in type 2 diabetes: a potential mechanism to lower plasma triglycerides

    NARCIS (Netherlands)

    Dallinga-Thie, Geesje M.; Berk-Planken, Ingrid I. L.; Bootsma, Aart H.; Jansen, Hans

    2004-01-01

    Apolipoprotein (apo)C-III is a constituent of HDL (HDL apoC-III) and of apoB-containing lipoproteins (LpB:C-III). It slows the clearance of triglyceride-rich lipoproteins (TRLs) by inhibition of the activity of the enzyme lipoprotein lipase (LPL) and by interference with lipoprotein binding to

  4. X-ray and neutron small-angle scattering studies of human serum lipoproteins

    International Nuclear Information System (INIS)

    Luzzati, V.; Tardieu, A.; Mateu, L.; Sardet, C.; Stuhrmann, H.B.; Aggerbeck, L.; Scanu, A.M.

    1976-01-01

    The paper describes an extended x-ray study of two types of human serum lipoproteins and a neutron study of one of them. The results are similar and to some extent complementary. Serum lipoproteins provide an excellent illustration of the wealth of information that can be obtained by a small-angle scattering approach to the structure of particles with non-uniform density distribution, by using solvents of variable density

  5. Structural and metabolic heterogeneity of plasma low density lipoproteins in nonhuman primates

    International Nuclear Information System (INIS)

    Marzetta, C.A.

    1986-01-01

    To test the hypothesis that a variety of precursor particles secreted by the liver could result in heterogeneity of LDL products in plasma, the metabolic fate of selected radiolabeled hepatic lipoproteins evaluated was determined in vivo. The hepatic lipoproteins evaluated were isolated from liver perfusate and were triglyceride-rich VLDL (d < 1.006 or d < 1.017) and phospholipid-rich LDL (1.017 < d < 1.049 or 1.030 < d < 1.063). Radiolabeled autologous plasma LDL were injected into recipient animals together with the radiolabeled hepatic lipoproteins. Density gradient ultracentrifugation and gel filtration were used to characterize the distribution of radiolabeled lipoproteins in the plasma at selected times after injection. A variety of hepatic lipoproteins were precursors to lipoproteins that resembled plasma LDL. Between 22 to 80% of the injected dose of radiolabeled hepatic lipoprotein apo B-100 was converted to plasma LDL-like particles, regardless of the type of hepatic lipoprotein injected. A kinetic model was generated to describe the metabolic behavior of hepatic VLDL-derived and plasma LDL-derived apo B-100 radioactivity. Both models required multiple metabolic pools to fit the data. Hepatic VLDL-derived apo B-100 radioactivity was metabolized rapidly into various kinds of LDL subfractions. This rapid conversion of hepatic VLDL apo B-100 to LDL apo B-100 may be analogous to the portion of plasma VLDL that gets converted to LDL without passing through the delipidation cascade that has been described in humans and has been termed direct LDL production

  6. Activation of Murine Macrophages by Lipoprotein and Lipooligosaccharide of Treponema denticola

    OpenAIRE

    Rosen, Graciela; Sela, Michael N.; Naor, Ronit; Halabi, Amal; Barak, Vivian; Shapira, Lior

    1999-01-01

    We have recently demonstrated that the periodontopathogenic oral spirochete Treponema denticola possesses membrane-associated lipoproteins in addition to lipooligosaccharide (LOS). The aim of the present study was to test the potential of these oral spirochetal components to induce the production of inflammatory mediators by human macrophages, which in turn may stimulate tissue breakdown as observed in periodontal diseases. An enriched lipoprotein fraction (dLPP) from T. denticola ATCC 35404 ...

  7. Deficiency of lipoprotein lipase in neurons modifies the regulation of energy balance and leads to obesity

    OpenAIRE

    Wang, H; Astarita, G; Taussig, MD; Bharadwaj, KG; Dipatrizio, NV; Nave, KA; Piomelli, D; Goldberg, IJ; Eckel, RH

    2011-01-01

    Free fatty acids (FFAs) suppress appetite when injected into the hypothalamus. To examine whether lipoprotein lipase (LPL), a serine hydrolase that releases FFAs from circulating triglyceride (TG)-rich lipoproteins, might contribute to FFA-mediated signaling in the brain, we created neuron-specific LPL-deficient mice. Homozygous mutant (NEXLPL-/-) mice were hyperphagic and became obese by 16 weeks of age. These traits were accompanied by elevations in the hypothalamic orexigenic neuropeptides...

  8. Comparison of human plasma low- and high-density lipoproteins as substrates for lecithin: cholesterol acyltransferase.

    Science.gov (United States)

    Barter, P J; Hopkins, G J; Gorjatschko, L

    1984-01-17

    A recent observation that lecithin: cholesterol acyltransferase (EC 2.3.1.43) interacts with both low-density lipoproteins (LDL) and high-density lipoproteins (HDL) in human plasma is in apparent conflict with an earlier finding that the purified enzyme, while highly reactive with isolated HDL, was only minimally reactive with LDL. There is evidence, however, that lecithin: cholesterol acyltransferase may exist physiologically as a component of a complex with other proteins and that studies with the isolated enzyme may therefore provide misleading results. Consequently, interactions of the enzyme with isolated human lipoproteins have been re-examined in incubations containing lecithin: cholesterol acyltransferase as a component of human lipoprotein-free plasma in which a physiologically active complex of the enzyme with other proteins may have been preserved. In this system there was a ready esterification of the free cholesterol associated with both LDL and HDL-subfraction 3 (HDL3) in reactions that obeyed typical enzyme-saturation kinetics. For a given preparation of lipoprotein-free plasma the Vmax values with LDL and with HDL3 were virtually identical. The apparent Km for free cholesterol associated with HDL3 was 5.6 X 10(-5) M, while for that associated with LDL it was 4.1 X 10(-4) M. This implied that, in terms of free cholesterol concentration, the affinity of HDL3 for lecithin: cholesterol acyltransferase was about 7-times greater than that of LDL. When expressed in terms of lipoprotein particle concentration, however, it was apparent that the affinity of LDL for the enzyme was considerably greater than that of HDL3. When the lipoprotein fractions were equated in terms of lipoprotein surface area, the apparent affinities of the two fractions for the enzyme were found to be comparable.

  9. Serum Sialic Acid Concentration and Content in ApoB-Containing Lipoproteins in Liver Diseases.

    Science.gov (United States)

    Gudowska, Monika; Gruszewska, Ewa; Cylwik, Bogdan; Panasiuk, Anatol; Filisiak, Robert; Szmitkowski, Maciej; Chrostek, Lech

    2016-01-01

    The great significance for the metabolism of lipoproteins is the composition of carbohydrate chain of apolipoproteins, where sialic acid (SA) is located. In VILDL and LDL sialic acid is attached to apolipoprotein B. The sialylation of serum proteins including apolipoprotein B can be affected in the course of liver diseases. Therefore, the aim of this study was to assess the effect of liver diseases on the concentration and content of SA in ApoB-containing lipoproteins. The tested group consisted of 165 patients (118 males, 47 females) with liver diseases: alcoholic cirrhosis, non-alcoholic cirrhosis, chronic hepatitis, toxic hepatitis, chronic viral hepatitis, and liver cancer. ApoB-containing lipoproteins were isolated by a turbidimetric procedure and SA concentration was measured according to an enzymatic method. There was a significant increase in the serum concentration of SA in ApoB-containing lipoproteins in viral hepatitis. Although the serum concentration of ApoB was not significantly different between specific liver diseases, the serum levels of SA in ApoB-containing lipoproteins appeared to be different. There is an association between SA concentration and triglycerides in alcoholic cirrhosis and viral hepatitis. Also, in viral hepatitis SA concentration correlated negatively with HDL-cholesterol. The content of SA in ApoB-containing lipoproteins in alcoholic cirrhosis and viral hepatitis was significantly higher than that in the control group, but did not differ between diseases. This study may explain the variations in serum lipids and lipoproteins in liver diseases. It seems that the reason for these abnormalities is the changes in the concentration of sialic acid in ApoB-containing lipoproteins.

  10. Effects of atorvastatin on biomarkers of immune activation, inflammation, and lipids in virologically suppressed, human immunodeficiency virus-1-infected individuals with low-density lipoprotein cholesterol <130 mg/dL (AIDS Clinical Trials Group Study A5275).

    Science.gov (United States)

    Nixon, Daniel E; Bosch, Ronald J; Chan, Ellen S; Funderburg, Nicholas T; Hodder, Sally; Lake, Jordan E; Lederman, Michael M; Klingman, Karin L; Aberg, Judith A

    Persistent immune activation and inflammation in virologically suppressed human immunodeficiency virus (HIV) infection are linked to excess cardiovascular risk. To evaluate atorvastatin as a strategy to reduce cardiovascular risk. A5275 was a multicenter, prospective, randomized, double-blind, placebo-controlled, cross-over pilot study of atorvastatin (10 mg/day for 4 weeks then 20 mg/day for 16 weeks) with a planned enrollment of 97 HIV-infected participants ≥18 years old, receiving boosted protease inhibitor-based antiretroviral therapy for ≥6 months, with plasma HIV-1 RNAs below limits of quantification ≥180 days, and fasting low-density lipoprotein (LDL) cholesterol ≥70 and atorvastatin treatment. Analyses were as-treated. Ninety-eight participants were enrolled at 31 U S sites and 73 completed study treatment. Atorvastatin treatment did not decrease T-lymphocyte or monocyte activation, circulating biomarker levels (interleukin-6, D-dimer, soluble CD14, soluble CD163, monocyte chemoattractant protein-1, interferon-gamma-induced protein-10, high-sensitivity C-reactive protein, CD40L, and P-selectin) or white blood cell Krüppel-like Factor 2/4 messenger RNA levels. Pre-to-post atorvastatin reductions in calculated LDL (-38%), oxidized-LDL (-33%), and lipoprotein-associated phospholipase A2 (-31%) were significant (P atorvastatin did not significantly decrease levels of soluble or cellular biomarkers of immune activation and inflammation but resulted in robust reductions in LDL cholesterol, oxLDL, and lipoprotein-associated phospholipase A 2 , biomarkers associated with cardiovascular risk. Copyright © 2016 National Lipid Association. All rights reserved.

  11. Small-Molecule Inhibitors of Gram-Negative Lipoprotein Trafficking Discovered by Phenotypic Screening

    Science.gov (United States)

    Fleming, Paul R.; MacCormack, Kathleen; McLaughlin, Robert E.; Whiteaker, James D.; Narita, Shin-ichiro; Mori, Makiko; Tokuda, Hajime; Miller, Alita A.

    2015-01-01

    In Gram-negative bacteria, lipoproteins are transported to the outer membrane by the Lol system. In this process, lipoproteins are released from the inner membrane by the ABC transporter LolCDE and passed to LolA, a diffusible periplasmic molecular chaperone. Lipoproteins are then transferred to the outer membrane receptor protein, LolB, for insertion in the outer membrane. Here we describe the discovery and characterization of novel pyridineimidazole compounds that inhibit this process. Escherichia coli mutants resistant to the pyridineimidazoles show no cross-resistance to other classes of antibiotics and map to either the LolC or LolE protein of the LolCDE transporter complex. The pyridineimidazoles were shown to inhibit the LolA-dependent release of the lipoprotein Lpp from E. coli spheroplasts. These results combined with bacterial cytological profiling are consistent with LolCDE-mediated disruption of lipoprotein targeting to the outer membrane as the mode of action of these pyridineimidazoles. The pyridineimidazoles are the first reported inhibitors of the LolCDE complex, a target which has never been exploited for therapeutic intervention. These compounds open the door to further interrogation of the outer membrane lipoprotein transport pathway as a target for antimicrobial therapy. PMID:25583975

  12. Small-molecule inhibitors of gram-negative lipoprotein trafficking discovered by phenotypic screening.

    Science.gov (United States)

    McLeod, Sarah M; Fleming, Paul R; MacCormack, Kathleen; McLaughlin, Robert E; Whiteaker, James D; Narita, Shin-Ichiro; Mori, Makiko; Tokuda, Hajime; Miller, Alita A

    2015-03-01

    In Gram-negative bacteria, lipoproteins are transported to the outer membrane by the Lol system. In this process, lipoproteins are released from the inner membrane by the ABC transporter LolCDE and passed to LolA, a diffusible periplasmic molecular chaperone. Lipoproteins are then transferred to the outer membrane receptor protein, LolB, for insertion in the outer membrane. Here we describe the discovery and characterization of novel pyridineimidazole compounds that inhibit this process. Escherichia coli mutants resistant to the pyridineimidazoles show no cross-resistance to other classes of antibiotics and map to either the LolC or LolE protein of the LolCDE transporter complex. The pyridineimidazoles were shown to inhibit the LolA-dependent release of the lipoprotein Lpp from E. coli spheroplasts. These results combined with bacterial cytological profiling are consistent with LolCDE-mediated disruption of lipoprotein targeting to the outer membrane as the mode of action of these pyridineimidazoles. The pyridineimidazoles are the first reported inhibitors of the LolCDE complex, a target which has never been exploited for therapeutic intervention. These compounds open the door to further interrogation of the outer membrane lipoprotein transport pathway as a target for antimicrobial therapy. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  13. Plasma Lipoprotein(a Levels and Atherosclerotic Renal Artery Stenosis in Hypertensive Patients

    Directory of Open Access Journals (Sweden)

    Cristiana Catena

    2015-03-01

    Full Text Available Background/Aims: The contribution of emergent cardiovascular risk factors to atherosclerotic renal artery stenosis (ARAS is debated. We investigated the relationship of lipoprotein(a and prothrombotic factors with ARAS in hypertension. Methods: In 50 hypertensive patients with angiographic evidence of ARAS and 58 hypertensive patients who had comparable cardiovascular risk factor burden but no evidence of renovascular disease, we measured renal function, lipoprotein(a, homocysteine, and hemostatic-fibrinolytic markers. Results: Patients with ARAS were more frequently smokers and had longer duration of hypertension, heavier antihypertensive treatment, and worse renal function than controls. Lipoprotein(a was higher in patients with ARAS than controls, whereas no differences were found in homocysteine and all hemostatic variables. Multivariate analysis showed that lipoprotein(a was associated with ARAS independent of other confounders including renal function and history of coronary heart, cerebrovascular, and peripheral artery disease. Conclusion: Lipoprotein(a might contribute to the development of ARAS and detection of elevated levels of this lipoprotein could raise the suspicion of renovascular disease in patients with high blood pressure.

  14. Serum prolactin, leptin, lipids and lipoproteins levels during antipsychotics treatment in Parkinson's disease and related psychosis.

    Science.gov (United States)

    Rustembegovic, Avdo; Sofic, Emin; Wichart, Ildiko

    2006-01-01

    Weight gain is a common adverse effect associated with the use of most typical and atypical antipsychotic. Aim of this study was to investigate serum prolactin, leptin, cholesterol, triglyceride, lipoproteins, such high density lipoprotein (HDL), and low density lipoprotein (LDL) levels in patients with Parkinson's disease (PD)-related psychosis during long-term medication with atypical antipsychotic. The study population comprised 40 patients, who were divided into 4 groups: olanzapine (n=10), risperidone (n=10), seroquel (n=10) monotherapy, a group of 10 patients receiving only antiparkinson drugs and a control group of 8 healthy persons. The patients were evaluated at baseline and at the sixth and twelfth week according to the Positive and Negative Syndrome Scale (PANSS), body mass index (BMI), and fasting serum prolactin, leptin, lipids and lipoproteins levels. Treatment of patients with olanzapine caused marked increase of serum LDL, cholesterol, triglyceride, and leptin levels (prelationship between serum leptin, lipid levels and BMI. However, treatment of patients with seroquel did not cause changes in serum prolactin, leptin, lipids, and lipoproteins levels. Our results suggest that treatment of patients with PD-related psychosis with seroquel appears to have minimal influence on serum leptin, prolactin, lipids, lipoproteins and BMI compared with olanzapine and risperidone.

  15. Acetaldehyde binding increases the catabolism of rat serum low-density lipoproteins

    International Nuclear Information System (INIS)

    Savolainen, M.J.; Baraona, E.; Lieber, C.S.

    1987-01-01

    Acetaldehyde was found to form adducts with rat serum lipoproteins. The binding of [ 14 C]acetaldehyde to lipoproteins was studied at low concentrations which are known to exist during ethanol oxidation. The amount of lipoprotein adducts was a linear function of acetaldehyde concentration up to 250 μM. Incubation of rat plasma low-density lipoproteins (LDL) with 200 μM acetaldehyde increased the disappearance rate of the 3 H-label from the cholesterol ester moiety of LDL injected into normal rats. The data show that even low concentrations of acetaldehyde are capable of affecting LDL metabolism. These findings may provide an explanation for the low concentrations of serum LDL in alcoholics. The alcohol-induced hyperlipidemia includes either a lack of increase or a decrease in the low-density lipoprotein (LDL) concentration, but the underlying mechanism is not known. It has been shown previously, that the acetylation of lysine residues of LDL apoprotein (apoB) by acetanhydride leads to rapid uptake of LDL particles by macrophages through a non-LDL receptor pathway. Since acetaldehyde, the first toxic metabolite of ethanol, is a chemically reactive compound capable of binding to proteins, they tested whether acetaldehyde forms adducts with serum lipoproteins and subsequently alters the catabolism of LDL. 19 references, 2 figures, 1 table

  16. The Journey of Lipoproteins Through the Cell: One Birthplace, Multiple Destinations.

    Science.gov (United States)

    Szewczyk, J; Collet, J-F

    2016-01-01

    Bacterial lipoproteins are a very diverse group of proteins characterized by the presence of an N-terminal lipid moiety that serves as a membrane anchor. Lipoproteins have a wide variety of crucial functions, ranging from envelope biogenesis to stress response. In Gram-negative bacteria, lipoproteins can be targeted to various destinations in the cell, including the periplasmic side of the cytoplasmic or outer membrane, the cell surface or the external milieu. The sorting mechanisms have been studied in detail in Escherichia coli, but exceptions to the rules established in this model bacterium exist in other bacteria. In this chapter, we will present the current knowledge on lipoprotein sorting in the cell. Our particular focus will be on the surface-exposed lipoproteins that appear to be much more common than previously assumed. We will discuss the different targeting strategies, provide numerous examples of surface-exposed lipoproteins and discuss the techniques used to assess their surface exposure. © 2016 Elsevier Ltd All rights reserved.

  17. Lipoprotein receptors in copper-deficient rats: in vitro binding of high-density lipoprotein subfractions to liver membranes

    International Nuclear Information System (INIS)

    Hassel, C.A.

    1986-01-01

    Three studies were conducted to determine whether the elevated plasma and HDL cholesterol levels observed in copper-deficient rats could be explained by the interaction of 125 I-HDL subfractions with liver membrane preparations in vitro. Rats from all studies were randomly divided into two dietary treatments, copper-deficient and adequate (0.7 mg and 8.0 mg Cukg diet, respectively). Total binding data and computer derived estimates (K/sub d/ and B/sub max/) were used to compare differences between treatments. Binding data from all experiments conformed to a one-site model. In all cases, binding was saturable and EDTA and pronase insensitive. Treatment differences were observed in Study I ( 125 I-apo E-free HDL binding to crude liver membranes). Significantly lower total binding and B/sub max/ were observed when lipoproteins and membranes from copper-deficient animals were used in the assay. Competition experiments from Studies II and III demonstrate that the different HDL subfractions competed effectively with one another for binding sites, indicating that apo E is not a determinant in binding of rat 125 I-HDL subfractions to purified liver plasma membranes

  18. A 90 minute soccer match decreases triglyceride and low density lipoprotein but not high-density lipoprotein and cholesterol levels

    Directory of Open Access Journals (Sweden)

    Nader - Rahnama

    2009-11-01

    Full Text Available

    • BACKGROUND: The association between the lipid profiles level and the incidence and severity of coronary heart disease (CHD is very pronounced in epidemiological studies, and an inverse relation between physical fitness and the incidence of coronary heart disease has been observed in many studies. The aim of this study was to investigate the impact of a soccer match on lipid parameters of professional soccer players.
    • METHODS: Twenty two professional soccer players participated in the study. Blood (10ml for determination of lipid profiles was obtained at rest and immediately after a 90 minute soccer match. Lipid parameters were measured using Boehringer Mannheim kits and Clinilab and BioMerieux analyser.
    • RESULTS: The results of this study showed that the triglyceride was significantly higher before the match than afterwards (159.09 ± 58.2 vs. 88.63 ± 34.1 mg/dl, p < 0.001, whereas the low-density lipoprotein (LDL was lower before the match than after it (98.04 ± 28.9 vs. 112.31 ± 30.5 mg/dl. Moreover, there were no significant differences in cholesterol concentration (171.4 ± 30.28 mg/dl vs. 173.18 ± 32.75 mg/dl and high-density lipoprotein (HDL concentration (34.04 ± 5.58 mg/dl vs. 34.4 ± 4.6 mg/dl between before and after the match.
    • CONCLUSIONS: Although the soccer competitive match has no favourable acute effect on lipid

    • Role of alpha-crystallin, early-secreted antigenic target 6-kDa protein and culture filtrate protein 10 as novel diagnostic markers in osteoarticular tuberculosis

      Directory of Open Access Journals (Sweden)

      Nazia Rizvi

      2016-07-01

      Full Text Available Osteoarticular tuberculosis constitutes about 3% of all tuberculosis cases. Early and accurate diagnosis of tuberculosis is a challenging problem especially in the case of osteoarticular tuberculosis owing to the lower number of bacilli. However, an accurate and timely diagnosis of the disease results in an improved efficacy of the given treatment. Besides the limitations of conventional methods, nowadays molecular diagnostic techniques have emerged as a major breakthrough for the early diagnosis of tuberculosis with high sensitivity and specificity. Alpha-crystallin is a dominantly expressed protein responsible for the long viability of the pathogen during the latent phase under certain stress conditions such as hypoxia and nitric oxide stress. Two other proteins—early secreted antigenic target-6 and culture filtrate protein-10—show high expression in the active infective phase of Mycobacterium tuberculosis. In this article, we focus on the different proteins expressed dominantly in latent/active tuberculosis, and which may be further used as prognostic biomarkers for diagnosing tuberculosis, both in latent and active phases.

    • Oxidative stress and plasma lipoproteins in cancer patients

      Energy Technology Data Exchange (ETDEWEB)

      Maia, Fernanda Maria Machado; Santos, Emanuelly Barbosa; Reis, Germana Elias [Universidade Estadual do Ceará, Fortaleza, CE (Brazil)

      2014-07-01

      To evaluate the relation between oxidative stress and lipid profile in patients with different types of cancer. This was an observational cross-sectional. A total of 58 subjects were evaluated, 33 males, divided into two groups of 29 patients each: Group 1, patients with cancer of the digestive tract and accessory organs; Group 2 patients with other types of cancers, all admitted to a public hospital. The plasma levels (lipoproteins and total cholesterol, HDL, and triglycerides, for example) were analyzed by enzymatic kits, and oxidative stress based on thiobarbituric acid-reactive substances, by assessing the formation of malondialdehyde. In general the levels of malondialdehyde of patients were high (5.00μM) as compared to 3.31μM for healthy individuals. The median values of lipids exhibited normal triacylglycerol (138.78±89.88mg/dL), desirable total cholesterol values (163.04±172.38mg/dL), borderline high LDL (151.30±178.25mg/dL) and low HDL (31.70±22.74mg/dL). Median HDL levels in Group 1 were lower (31.32mg/dL) than the cancer patients in Group 2 (43.67mg/dL) (p=0.038). Group 1 also showed higher levels of oxidative stress (p=0.027). The lipid profile of patients with cancer was not favorable, which seems to have contributed to higher lipid peroxidation rate, generating a significant oxidative stress.

  1. Effect of soy protein on swine intestinal lipoproteins

    International Nuclear Information System (INIS)

    Ho, H.T.

    1987-01-01

    Hypocholesterolemic effect of soy protein appears to be the result of reduced cholesterol absorption and enhanced cholesterol excretion. The objective of this study is to delineate the underlying mechanism of soy protein effect on cholesterol absorption. At the end of a 5-week soy-protein or casein diet, swine were subjected to cannulation of mesenteric lymph duct under halothane anesthesia. A single dose of 250 μCi [ 14 C]-cholesterol and 10 mCi [ 3 H]-leucine was infused into the upper jejunum two hours after one-fifth of daily food was given. Then lymph was collected hourly for three hours and the lipoprotein fractions were separated by ultracentrifugation. SDS-PAGE (5%) was used to measure the concentrations of individual apoproteins by densitometric scanning. The three-hour lymphatic transport of cholesterol in casein-fed swine was significantly higher than in those fed soy protein. Triglyceride transports were similar in two groups. The [ 3 H]-leucine incorporation study revealed that transport of apo B-48 bore a significant positive relationship to transport of cholesterol in both chylomicron and VLDL fractions of mesenteric lymph. A greater apo B-48 secretion with higher specific activity was probably responsible for the greater transport of cholesterol in chylomicrons in casein-fed swine. On the other hand, the lesser cholesterol transport in chylomicrons in soy protein-fed swine was probably caused by lower apo B-48 secretion. Similarly, the transport of lymph VLDL cholesterol in swine fed casein or soy protein paralleled the amount of accompanying apo B-48. Dietary proteins probably influence the intestinal synthesis of apo B-48 which in turn affects cholesterol transport into the lymphatics

  2. Association of serum lipoprotein (a) with hypertension in diabetic patients

    International Nuclear Information System (INIS)

    Nasri, H.

    2008-01-01

    To evaluate the influence of serum Lp(a) concentration on hypertension in patients with diabetes mellitus (DM) and under treatment with oral hypoglycemic agents or insulin injections, we studied 122 patients, 82 females and 40 males with a mean age of 63+-10 years and duration of DM and HTN of 7.4+-5.8 and 3.2+-4.6 years, respectively. The mean systolic and diastolic blood pressure (BP) was 138+-23 mmHg and 83+-12mmHg, respectively. In this cross-sectional study, we measured serum lipoprotein (a) (Lp(a), glycosilated hemoglobin (HbA1c) and other lipids while the patients were receiving either oral hypoglycemic agents or insulin. In addition, body mass index (BMI) and creatinine clearance (CrCL) were assessed. The mean serum Lp(a) was 22.2+-24.7 mg/dl (median: 18.3 mg/dl), and serum Lp(a) levels >30 mg/dl was found in 29(23.8%) patients. There were significant positive correlations of duration of DM and duration of hypertension, and serum Lp(a) levels with of systoli and diastolic levels of BP. However, a significant inverse correlation of serum Lp(a) with CrCl were observed. This study suggests that kidney function is an independent determination of Lp(a) and HTN in diabetic patients. Furthermore Lp(a) in diabetic patients may have important implications for the increased susceptibility to vascular diseases in these patients. (author)

  3. Radioiodinated cholesteryl ester analogs as residualizing tracers of lipoproteins disposition

    International Nuclear Information System (INIS)

    DeForge, L.E.

    1989-01-01

    Due to the importance of low density lipoprotein (LDL) in lipid metabolism and atherosclerosis, efforts were made to incorporate 125 I-cholesteryl iopanoate ( 125 I-CI), a residualizing cholesteryl ester (CE) analog, into the lipid core of LDL. This preparation is potentially useful as a scintigraphically detectable tracer of LDL uptake into atheroma and tissues such as the adrenal and liver. Initial studies using a cholesterol-fed rabbit model of atherosclerosis validated the use of 125 I-CI as a tracer of CE deposition. However, scintigraphy revealed considerable nonspecific 125 I-CI uptake due to tissue cholesterol loading. An alternative animal model was the guinea pig, which responds moderately to cholesterol feeding and carries the plasma cholesterol predominantly as LDL. Dietary fat and cholesterol, coupled with chronic aortic injury caused by an indwelling catheter, resulted in lipid containing, smooth muscle cell proliferative lesions in many animals. However, further studies are necessary to fully characterize this model. In additional studies, in vitro methods for incorporating 125 I-CI into LDL were examined. These included a reconstitution procedure described by Krieger et al. and a procedure involving incubation of detergent (Tween 20)-solubilized 125 I-CI with plasma. Although both LDL preparations were taken up normally by cultured fibroblasts, the plasma clearance rate of reconstituted LDL was markedly abnormal in guinea pigs. In contrast, LDL labeled by the detergent method cleared from the plasma identically to a radioiodinated LDL control. Therefore, this latter procedure was also used to incorporate two novel radioiodinated cholesteryl ether analogs 125 I-CI cholesteryl m-iodobenzyl ether [ 125 I-CIDE] and 125 I-cholesteryl 12-(miodophenyl)dodecyl ether [ 125 I-CIDE] into LDL

  4. Aggregation and fusion of modified low density lipoprotein.

    Science.gov (United States)

    Pentikäinen, M O; Lehtonen, E M; Kovanen, P T

    1996-12-01

    In atherogenesis, low density lipoprotein (LDL, diameter 22 nm) accumulates in the extracellular space of the arterial intima in the form of aggregates of lipid droplets (droplet diameter up to 400 nm). Here we studied the effects of various established in vitro LDL modifications on LDL aggregation and fusion. LDL was subjected to vortexing, oxidation by copper ions, proteolysis by alpha-chymotrypsin, lipolysis by sphingomyelinase, and nonenzymatic glycosylation, and was induced to form adducts with malondialdehyde or complexes with anti-apoB-100 antibodies. To assess the amount of enlarged LDL-derived structures formed (due to aggregation or fusion), we measured the turbidity of solutions containing modified LDL, and quantified the proportion of modified LDL that 1) sedimented at low-speed centrifugation (14,000 g), 2) floated at an increased rate at high-speed centrifugation (rate zonal flotation at 285,000 gmax), 3) were excluded in size-exclusion column chromatography (exclusion limit 40 MDa), or 4) failed to enter into 0.5%. Fast Lane agarose gel during electrophoresis. To detect whether particle fusion had contributed to the formation of the enlarged LDL-derived structures, particle morphology was examined using negative staining and thin-section transmission electron microscopy. We found that 1) aggregation was induced by the formation of LDL-antibody complexes, malondialdehyde treatment, and glycosylation of LDL; 2) fusion of LDL was induced by proteolysis of LDL by alpha-chymotrypsin; and 3) aggregation and fusion of LDL were induced by vortexing, oxidation by copper ions, and lipolysis by sphingomyclinase of LDL. The various modifications of LDL differed in their ability to induce aggregation and fusion.

  5. Lipoprotein (a): a potential biological marker for unruptured intracranial aneurysms.

    Science.gov (United States)

    Phillips, J; Roberts, G; Bolger, C; el Baghdady, A; Bouchier-Hayes, D; Farrell, M; Collins, P

    1997-05-01

    The diagnosis and treatment of intracranial aneurysms (IAs) prior to rupture reduces the high morbidity and mortality associated with their occurrence. Elevated serum lipoprotein (a) [Lp(a)] level, an independent risk factor for atherogenesis, has been demonstrated in sporadic IA disease (1). The purpose of this study was to assess the degree of correlation between elevated Lp(a) levels and the occurrence of IAs in asymptomatic first degree relatives of index cases from three families exhibiting a familial tendency towards IA development. 25 family members and 41 healthy controls were screened by random serum Lp(a) sampling. All family members received 4-vessel cerebral angiography. Eleven family members were found on angiography to harbour asymptomatic aneurysms and all were successfully treated by surgery. Of these 11, ten had significantly raised serum Lp(a) levels (> 30 mg%). Fourteen family members had negative angiograms. Eight of this latter group, mean age 43.6 +/- 3.8 years, had serum Lp(a) levels above the normal range. Mean Lp(a) levels were 53.7 +/- 1.2 mg% in subjects with aneurysms compared with 22.1 +/- 1.45 mg% in subjects without demonstrable aneurysms and 10.5 +/- 0.48 mg% in the control population. The prevalence of elevated Lp(a) levels in these families and the high degree of association of raised Lp(a) levels with the presence of IAs in several family members warrants follow up of angiographically negative young subjects. We require a case-control study to establish whether particular polymorphisms at the apoprotein (a) gene level are associated with the occurrence of IAs in these families.

  6. Association of Serum Lipoprotein (a with Hypertension in Diabetic Patients

    Directory of Open Access Journals (Sweden)

    Nasri Hamid

    2008-01-01

    Full Text Available To evaluate the influence of serum Lp(a concentration on hypertension in patients with diabetes mellitus (DM and under treatment with oral hypoglycemic agents or insulin injections, we studied 122 patients, 82 females and 40 males with a mean age of 63 ± 10 years and duration of DM and HTN of 7.4 ± 5.8 and 3.2 ± 4.6 years, respectively. The mean systolic and diastolic blood pressure (BP were 138 ±23 mmHg and 83 ± 12 mmHg, respectively. In this cross-sectional study, we measured serum lipoprotein(a (Lp(a, glycosilated hemoglobine (HbA1c and other lipids while the patients were receiving either oral hypogycemic agents or insulin. In addition, body mass index (BMI and creatinine clearance (CrCL were asessed. The mean serum Lp(a was 22.2 ± 24.7 mg/dl (median: 18.3 mg/dl, and serum Lp(a levels > 30 mg/dl was found in 29 (23.8% patients. There were significant positive correlations of duration of DM and duration of hypertension, and serum Lp(a levels with of systoli and diastolic levels of BP. However, a significant inverse correlation of serum Lp(a with CrCL were observed. This study suggests that kidney function is an independent determinant of Lp(a and HTN in diabetic patients. Furthermore, Lp(a in diabetic patients may have important implications for the increased susceptibility to vascular disease in these patients.

  7. Biomimetic High-Density Lipoproteins from a Gold Nanoparticle Template

    Science.gov (United States)

    Luthi, Andrea Jane

    For hundreds of years the field of chemistry has looked to nature for inspiration and insight to develop novel solutions for the treatment of human diseases. The ability of chemists to identify, mimic, and modifiy small molecules found in nature has led to the discovery and development of many important therapeutics. Chemistry on the nanoscale has made it possible to mimic natural, macromolecular structures that may also be useful for understanding and treating diseases. One example of such a structure is high-density lipoprotein (HDL). The goal of this work is to use a gold nanoparticle (Au NP) as a template to synthesize functional mimics of HDL and characterize their structure and function. Chapter 1 details the structure and function of natural HDL and how chemistry on the nanoscale provides new strategies for mimicking HDL. This Chapter also describes the first examples of using nanoparticles to mimic HDL. Chapter 2 reports the synthesis and characterization of biomimetic HDL using different sizes of Au NPs and different surface chemistries and how these variables can be used to tailor the properties of biomimetic HDL. From these studies the optimal strategy for synthesizing biomimetic HDL was determined. In Chapter 3, the optimization of the synthesis of biomimetic HDL is discussed as well as a full characterization of its structure. In addition, the work in this chapter shows that biomimetic HDL can be synthesized on a large scale without alterations to its structure or function. Chapter 4 focuses on understanding the pathways by which biomimetic HDL accepts cholesterol from macrophage cells. The results of these studies demonstrate that biomimetic HDL is able to accept cholesterol by both active and passive pathways of cholesterol efflux. In Chapter 5 the preliminary results of in vivo studies to characterize the pharmacokinetics and pharmacodynamics of biomimetic HDL are presented. These studies suggest that biomimetic HDL traffics through tissues prone to

  8. An energetic orphan in an endocrine tissue: a revised perspective of the function of estrogen receptor-related receptor alpha in bone and cartilage.

    Science.gov (United States)

    Bonnelye, Edith; Aubin, Jane E

    2013-02-01

    Estrogen receptor-related receptor alpha (ERRα) is an orphan nuclear receptor with sequence homology to the estrogen receptors, ERα/β, but it does not bind estrogen. ERRα not only plays a functional role in osteoblasts but also in osteoclasts and chondrocytes. In addition, the ERRs, including ERRα, can be activated by coactivators such as peroxisome proliferator-activated receptor-gamma coactivator-1 (PGC1α and β) and are implicated in adipogenesis, fatty acid oxidation, and oxidative stress defense, suggesting that ERRα-through its activity in bone resorption and adipogenesis--may regulate the insulin and leptin pathways and contribute to aging-related changes in bone and cartilage. In this review, we discuss data on ERRα and its cellular and molecular modes of action, which have broad implications for considering the potential role of this orphan receptor in cartilage and bone endocrine function, on whole-organism physiology, and in the bone aging process. Copyright © 2013 American Society for Bone and Mineral Research.

  9. Analysis of Epidermal Growth Factor Receptor Related Gene Expression Changes in a Cellular and Animal Model of Parkinson’s Disease

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    In-Su Kim

    2017-02-01

    Full Text Available We employed transcriptome analysis of epidermal growth factor receptor related gene expression changes in cellular and animal models of Parkinson’s disease (PD. We used a well-known Parkinsonian toxin 1-methyl-4-phenylpyridine (MPP+ to induce neuronal apoptosis in the human neuroblastoma SH-SY5Y cell line. The MPP+-treatment of SH-SY5Y cells was capable of inducing neuro-apoptosis, but it remains unclear what kinds of transcriptional genes are affected by MPP+ toxicity. Therefore the pathways that were significantly perturbed in MPP+ treated human neuroblastoma SH-SY5Y cells were identified based on genome-wide gene expression data at two time points (24 and 48 h. We found that the Epidermal Growth Factor Receptor (EGFR pathway-related genes showed significantly differential expression at all time points. The EGFR pathway has been linked to diverse cellular events such as proliferation, differentiation, and apoptosis. Further, to evaluate the functional significance of the altered EGFR related gene expression observed in MPP+-treated SH-SY5Y cells, the EGFR related GJB2 (Cx26 gene expression was analyzed in an MPP+-intoxicated animal PD model. Our findings identify that the EGFR signaling pathway and its related genes, such as Cx26, might play a significant role in dopaminergic (DAergic neuronal cell death during the process of neuro-apoptosis and therefore can be focused on as potential targets for therapeutic intervention.

  10. The lipid- and lipoprotein- [LDL-Lp(a)] apheresis techniques. Updating.

    Science.gov (United States)

    Stefanutti, C; Morozzi, C; Perrone, G; Di Giacomo, S; Vivenzio, A; D'Alessandri, G

    2012-01-01

    Therapeutic plasmapheresis allows the extracorporeal removal of plasmatic lipoproteins (Lipid-apheresis) (LA). It can be non selective (non specific), semi - selective or selective low density lipoprotein-lipoprotein(a) (specific [LDL- Lp(a)] apheresis) (Lipoprotein apheresis, LDLa). The LDL removal rate is a perfect parameter to assess the system efficiency. Plasma-Exchange (PEX) cannot be considered either specific nor, selective. In PEX the whole blood is separated into plasma and its corpuscular components usually through centrifugation or rather filtration. The corpuscular components mixed with albumin solution plus saline (NaCl 0.9%) solution at 20%-25%, are then reinfused to the patient, to substitute the plasma formerly removed. PEX eliminates atherogenic lipoproteins, but also other essential plasma proteins, such as albumin, immunoglobulins, and hemocoagulatory mediators. Cascade filtration (CF) is a method based on plasma separation and removal of plasma proteins through double filtration. During the CF two hollow-fiber filters with pores of different diameter are used to eliminate the plasma components of different weight and molecular diameter. A CF system uses a first polypropylene filter with 0.55 µm diameter pores and a second one of diacetate of cellulose with 0.02 µm pores. The first filter separates the whole blood, and the plasma is then perfused through a second filter which allows the recovery of molecules with a diameter lower than 0.02 µm, and the removal of molecules larger in diameter as apoB100-containing lipoproteins. Since both albumin and immunoglobulins are not removed, or to a negligible extent, plasma-expanders, substitution fluids, and in particular albumin, as occurs in PEX are not needed. CF however, is characterized by lower selectivity since removes also high density lipoprotein (HDL) particles which have an antiatherogenic activity. In the 80's, a variation of Lipid-apheresis has been developed which allows the LDL

  11. Comparison of soymilk and probiotic soymilk effects on serum high-density lipoprotein cholesterol and low-density lipoprotein cholesterol in diabetic Wistar rats

    Directory of Open Access Journals (Sweden)

    Mina Babashahi

    2015-04-01

    Full Text Available BACKGROUND: Soy milk (SM and its fermented products are identified as rich sources of bioactive compounds helping to manage and to reduce the risk of chronic disease. This study aimed to compare the effects of SM and probiotic SM (PSM consumption on serum low-density lipoprotein cholesterol (LDL-C and high-density lipoprotein cholesterol (HDL-C in diabetic Wistar rats. METHODS: Probiotic SM was prepared by fermentation of the plain SM with a native strain of Lactobacillus plantarum. 20 streptozotocin-nicotinamide-induced diabetic Wistar rats were divided into two groups based on the type of administered SM (SM group and PSM group. The animals were fed with 1 ml/day of either soy or PSM for 21 days. The serum lipoprotein levels were analyzed at baseline and the end of the intervention period. RESULTS: HDL-C increased significantly in PSM group. Furthermore, this group showed more percent of change in increased HDL-C in compression with SM group (P < 0.050. Regarding LDL-C level, rats fed with SM was not significantly different from the PSM group (P < 0.050; though, this biomarker was reduced in both group. CONCLUSION: Probiotic SM could modulate blood lipoprotein levels. Thus, it may be considered in managing diabetes complications and atherosclerotic risks. 

  12. Different effects of diets rich in olive oil, rapeseed oil and sunflower-seed oil on postprandial lipid and lipoprotein concentrations and on lipoprotein oxidation susceptibility

    DEFF Research Database (Denmark)

    Nielsen, Nina Skall; Pedersen, A.; Sandstrøm, B.

    2002-01-01

    oxidation of fasting and postprandial lipoproteins eighteen males consumed diets enriched with rapeseed oil (RO), olive oil (OO), or sunflower-seed oil (SO) in randomised order for periods of 3 weeks followed by a RO test meal. In the postprandial state the concentrations of cholesterol and triacylglycerol...

  13. Effects of 1,2-cyclohexanedione modification on the metabolism of very low density lipoprotein apolipoprotein B: potential role of receptors in intermediate density lipoprotein catabolism

    International Nuclear Information System (INIS)

    Packard, C.J.; Boag, D.E.; Clegg, R.; Bedford, D.; Shepherd, J.

    1985-01-01

    The conversion of very low density (VLDL) to low density lipoproteins (LDL) is a two-step process. The first step is mediated by lipoprotein lipase, but the mechanism responsible for the second is obscure. In this study we examined the possible involvement of receptors at this stage. Apolipoprotein B (apoB)-containing lipoproteins were separated into three fractions, VLDL (Sf 100-400), an intermediate fraction IDL (Sf 12-100), and LDL (Sf 0-12). Autologous 125I-labeled VLDL and 131I-labeled 1,2-cyclohexanedione-modified VLDL were injected into the plasma of four normal subjects and the rate of transfer of apoB radioactivity was followed through IDL to LDL. Modification did not affect VLDL to IDL conversion. Thereafter, however, the catabolism of modified apoB in IDL was retarded and its appearance in LDL was delayed. Hence, functional arginine residues (and by implication, receptors) are required in this process. Confirmation of this was obtained by injecting 125I-labeled IDL and 131I-labeled cyclohexanedione-treated IDL into two additional subjects. Again, IDL metabolism was delayed by approximately 50% as a result of the modification. These data are consistent with the view that receptors are involved in the metabolism of intermediate density lipoprotein

  14. Association of polymorphisms in genes involved in lipoprotein metabolism with plasma concentrations of remnant lipoproteins and HDL subpopulations before and after hormone therapy in postmenopausal women

    Science.gov (United States)

    Diabetes mellitus is a major risk factor for coronary heart disease (CHD), renal failure, retinopathy, and neuropathy. Lowering glycosylated hemoglobin (HbA1c) as well as low-density lipoprotein-cholesterol (LDL-C) has been associated with a decreased risk of these complications. We evaluated the ut...

  15. Elevated plasma low-density lipoprotein and high-density lipoprotein cholesterol levels in amenorrheic athletes: effects of endogenous hormone status and nutrient intake.

    Science.gov (United States)

    Friday, K E; Drinkwater, B L; Bruemmer, B; Chesnut, C; Chait, A

    1993-12-01

    To determine the interactive effects of hormones, exercise, and diet on plasma lipids and lipoproteins, serum estrogen and progesterone levels, nutrient intake, and plasma lipid, lipoprotein, and apolipoprotein concentrations were measured in 24 hypoestrogenic amenorrheic and 44 eumenorrheic female athletes. When compared to eumenorrheic athletes, amenorrheic athletes had higher levels of plasma cholesterol (5.47 +/- 0.17 vs. 4.84 +/- 0.12 mmol/L, P = 0.003), triglyceride (0.75 +/- 0.06 vs. 0.61 +/- 0.03 mmol/L, P = 0.046), low-density lipoprotein (LDL; 3.16 +/- 0.15 vs. 2.81 +/- 0.09 mmol/L, P = 0.037), high-density lipoprotein (HDL; 1.95 +/- 0.07 vs. 1.73 +/- 0.05 mmol/L, P = 0.007), and HDL2 (0.84 +/- 0.06 vs. 0.68 +/- 0.04 mmol/L, P = 0.02) cholesterol. Plasma LDL/HDL cholesterol ratios, very low-density lipoprotein and HDL3 cholesterol, and apolipoprotein A-I and A-II levels were similar in the two groups. Amenorrheic athletes consumed less fat than eumenorrheic subjects (52 +/- 5 vs. 75 +/- 3 g/day, P = 0.02), but similar amounts of calories, cholesterol, protein, carbohydrate, and ethanol. HDL cholesterol levels in amenorrheic subjects correlated positively with the percent of dietary calories from fat (r = 0.42, n = 23, P = 0.045) but negatively with the percent from protein (r = -0.49, n = 23, P = 0.017). Thus, exercise-induced amenorrhea may adversely affect cardiovascular risk by increasing plasma LDL and total cholesterol. However, cardioprotective elevations in plasma HDL and HDL2 cholesterol may neutralize the risk of cardiovascular disease in amenorrheic athletes.

  16. The relationship between oxidized lipoprotein(a and carotid atherosclerosis in asymptomatic subjects: A comparison with native lipoprotein(a

    Directory of Open Access Journals (Sweden)

    Taniguchi Nobuyuki

    2011-10-01

    Full Text Available Abstract Background Oxidized lipoprotein(a (oxLp(a can be a more potent marker of atherogenesis than native Lp(a, although Lp(a is considered to be a risk factor for atherosclerotic diseases. Limited clinical data are available regarding the significance of oxLp(a in atherosclerotic manifestations. This study aimed to investigate the association between the serum oxLp(a and carotid artery intima-media thickness (CIMT, in comparison to the serum Lp(a levels, among asymptomatic subjects. Methods The atheroscrerosis-related variables including Lp(a and oxLp(a were measured in 136 cardiovascular disease-free subjects (61 males and 75 females, mean age of 64 years. The serum oxLp(a level was quantified using a sandwich ELISA system. The CIMT level was ultrasonographically measured on bilateral carotid arteries. Results The median level of Lp(a was 120 μmol/L, oxLp(a was 0.06 nmol/L, and CIMT was 0.7 mm, respectively. A simple correlation test showed that the CIMT was significantly and positively correlated with age, systolic blood pressure and oxLp(a (r = 0.208, P Conclusions These results suggest that oxLp(a may be more closely associated with accelerated carotid atherosclerosis, in comparison to Lp(a, in this population. This finding can be important for obtaining a better understanding of the different atherogenic roles played by oxLp(a in comparison to Lp(a.

  17. EFFECTS OF EXERCISE TRAINING ON BLOOD LIPIDS AND LIPOPROTEINS IN CHILDREN AND ADOLESCENTS

    Directory of Open Access Journals (Sweden)

    Kerstin Stoedefalke

    2007-09-01

    Full Text Available The following review aims to describe what is known about the effects of exercise training in children and adolescents on the following blood lipids and lipoproteins: total cholesterol (TC, high density lipoprotein cholesterol (HDL-C, low density lipoprotein cholesterol (LDL-C, and triglycerides (TG. Only studies that described mode, frequency, duration and intensity of the exercise were included in the review. The results of the studies reviewed were equivocal. Clearly the effects of exercise training on the blood lipid and lipoprotein levels of normolipidemic children and adolescents are equivocal. Of the 14 studies reviewed, six observed a positive alteration in the blood lipid and lipoprotein profile, four of the studies observed no alteration in the blood lipid and lipoprotein profile and one study observed a negative effect on HDL-C but an overall improvement in the lipid and lipoprotein profile due to the decrease in the TC/HDL ratio. It appears that methodological problems present in the majority of the exercise training studies limits the ability to make a conclusive, evidence based statement regarding the effect exercise training has on blood lipid levels in normolipidemic children. Most of the research design flaws can be linked to one or more of the following: small numbers of subjects in each study, low or no representation of girls, inclusion of both boys and girls in the subject pool, inclusion of boys and girls at different maturational stages in the subject pool, exercise training regimes that do not adequately control for exercise intensity, exercise training regimes that do not last longer than 8 weeks and exercise training studies that do not have an adequate exercise volume to elicit a change. Ideally, future research should focus on longitudinal studies which examine the effects of exercise training from the primary school years through adulthood

  18. Characterization of Two Metal Binding Lipoproteins as Vaccine Candidates for Enterococcal Infections.

    Science.gov (United States)

    Romero-Saavedra, Felipe; Laverde, Diana; Budin-Verneuil, Aurélie; Muller, Cécile; Bernay, Benoit; Benachour, Abdellah; Hartke, Axel; Huebner, Johannes

    2015-01-01

    Enterococcus faecium and faecalis are Gram-positive opportunistic pathogens that have become leading causes of nosocomial infections over the last decades. Especially multidrug resistant enterococci have become a challenging clinical problem worldwide. Therefore, new treatment options are needed and the identification of alternative targets for vaccine development has emerged as a feasible alternative to fight the infections caused by these pathogens. We extrapolate the transcriptomic data from a mice peritonitis infection model in E. faecalis to identify putative up-regulated surface proteins under infection conditions in E. faecium. After the bionformatic analyses two metal binding lipoproteins were identified to have a high homology (>72%) between the two species, the manganese ABC transporter substrate-binding lipoprotein (PsaAfm,) and the zinc ABC transporter substrate-binding lipoprotein (AdcAfm). These candidate lipoproteins were overexpressed in Escherichia coli and purified. The recombinant proteins were used to produce rabbit polyclonal antibodies that were able to induce specific opsonic antibodies that mediated killing of the homologous strain E. faecium E155 as well as clinical strains E. faecium E1162, Enterococcus faecalis 12030, type 2 and type 5. Mice were passively immunized with the antibodies raised against recombinant lipoproteins, showing significant reduction of colony counts in mice livers after the bacterial challenge and demonstrating the efficacy of these metal binding lipoproteins as promising vaccine candidates to treat infections caused by these enterococcal pathogens. Overall, our results demonstrate that these two metal binding lipoproteins elicited specific, opsonic and protective antibodies, with an extensive cross-reactivity and serotype-independent coverage among these two important nocosomial pathogens. Pointing these two protein antigens as promising immunogens, that can be used as single components or as carrier proteins

  19. Accumulation of native and methylated low density lipoproteins by healing rabbit arterial wall

    International Nuclear Information System (INIS)

    Fischman, A.J.; Lees, A.M.; Lees, R.S.; Barlai-Kovach, M.; Strauss, H.W.

    1987-01-01

    To determine whether healing arterial wall accumulation of low density lipoproteins (LDL) is mediated by the high affinity LDL receptor, normocholesterolemic rabbits were injected with 125 I-LDL, /sup 99m/Tc-LDL, or the reductively methylated analogs of these compounds ( 125 I-MeLDL, /sup 99m/Tc-MeLDL), 1 month after balloon catheter deendothelialization of the abdominal aorta. If the mechanism of accumulation requires interaction with the LDL receptor, reductively methylated lipoproteins which do not bind to the receptor should not accumulate in healing arterial wall. Twenty-four hours after injection of labelled lipoproteins, each animal was injected with Evans blue dye, in order to distinguish reendothelialized from deendothelialized aorta. One hour after dye injection, the aorta was fixed, removed, divided into abdominal (ballooned) and thoracic (unballooned) regions and counted. For all lipoprotein preparations, there were three to four times as many counts in the abdominal as in the thoracic aorta. En face autoradiographs were made of the aortas that had been exposed to 125 I-labelled lipoproteins. In the autoradiographs, the areas of the lowest activity corresponded to the centers of healing endothelial islands. The most intense radioactivity for both lipoproteins occurred in the region of the leading edge of the endothelial islands where active endothelial regeneration was in progress. The overall distribution of native and MeLDL accumulation was the same. The results suggest that low density lipoproteins are accumulated in areas of active endothelial regeneration by a mechanism that does not involve the high affinity LDL receptor

  20. Triglyceride-Rich Lipoproteins and Atherosclerotic Cardiovascular Disease: New Insights From Epidemiology, Genetics, and Biology.

    Science.gov (United States)

    Nordestgaard, Børge G

    2016-02-19

    Scientific interest in triglyceride-rich lipoproteins has fluctuated over the past many years, ranging from beliefs that these lipoproteins cause atherosclerotic cardiovascular disease (ASCVD) to being innocent bystanders. Correspondingly, clinical recommendations have fluctuated from a need to reduce levels to no advice on treatment. New insight in epidemiology now suggests that these lipoproteins, marked by high triglycerides, are strong and independent predictors of ASCVD and all-cause mortality, and that their cholesterol content or remnant cholesterol likewise are strong predictors of ASCVD. Of all adults, 27% have triglycerides >2 mmol/L (176 mg/dL), and 21% have remnant cholesterol >1 mmol/L (39 mg/dL). For individuals in the general population with nonfasting triglycerides of 6.6 mmol/L (580 mg/dL) compared with individuals with levels of 0.8 mmol/L (70 mg/dL), the risks were 5.1-fold for myocardial infarction, 3.2-fold for ischemic heart disease, 3.2-fold for ischemic stroke, and 2.2-fold for all-cause mortality. Also, genetic studies using the Mendelian randomization design, an approach that minimizes problems with confounding and reverse causation, now demonstrate that triglyceride-rich lipoproteins are causally associated with ASCVD and all-cause mortality. Finally, genetic evidence also demonstrates that high concentrations of triglyceride-rich lipoproteins are causally associated with low-grade inflammation. This suggests that an important part of inflammation in atherosclerosis and ASCVD is because of triglyceride-rich lipoprotein degradation and uptake into macrophage foam cells in the arterial intima. Taken together, new insights now strongly suggest that elevated triglyceride-rich lipoproteins represent causal risk factors for low-grade inflammation, ASCVD, and all-cause mortality. © 2016 American Heart Association, Inc.

  1. [Measurement of sialic acid from lipoproteins and human plasma by liquid chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Guo, Shoudong; Sang, Hui; Yang, Nana; Kan, Yujie; Li, Fuyu; Li, Yu; Li, Fangyuan; Qin, Shucun

    2014-11-01

    A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was established to quantify sialic acid (N-acetylneuraminic acid, NANA) from lipoproteins and human plasma. The method was used to investigate the different contents of NANA from lipoproteins between diabetic with an average age of 51.6 years and healthy participants with an average age of 50.7 years. The NANA from lipoprotein samples was hydrolyzed by acetic acid (pH = 2) at 80 °C for 2 h and analyzed by the optimized LC-MS/MS method after high speed centrifugation and filtration. The limits of detection and quantification of NANA were 7.4 and 24.5 pg, respectively. The linear range was 2.5-80 ng/mL for NANA and the correlation coefficient (R2) was more than 0.998. The levels of NANA in the plasma of type II diabetics and healthy participants were (548.3 ± 88.9) and (415.3 ± 55.5) mg/L, respectively; and the levels of NANA from very low density lipoproteins (VLDL), low density lipoproteins (LDL), and high density lipoproteins (HDL) of the type II diabetics and the healthy participants were (4.91 ± 0.19), (6.95 ± 0.28), (3.61 ± 0.22) μg/mg and (2.90 ± 0.27), (7.03 ± 0.04), (2.40 ± 0.09) μg/mg, respectively. The sialic acid levels of VLDL and HDL from the type II diabetics were markedly higher than those of the corresponding healthy participants with the similar ages (P lipoproteins, and is reproducible and time saving.

  2. Involvement of microtubules in lipoprotein degradation and utilization for steroidogenesis in cultured rat luteal cells

    International Nuclear Information System (INIS)

    Rajan, V.P.; Menon, K.M.

    1985-01-01

    Cells isolated from superovulated rat ovaries metabolize low density lipoprotein (LDL) and high density lipoprotein (HDL) of human or rat origin and use the lipoprotein-derived cholesterol as a precursor for progesterone production. Under in vitro conditions, both lipoproteins are internalized and degraded in the lysosomes, although degradation of HDL is of lower magnitude than that of LDL. In this report we have examined the role of cellular microtubules in the internalization and degradation of human LDL and HDL in cultured rat luteal cells. The microtubule depolymerizing agents colchicine, podophyllotoxin, vinblastine, and nocodazole as well as taxol, deuterium oxide, and dimethyl sulfoxide, which are known to rapidly polymerize cellular tubulin into microtubules, were used to block the function of microtubules. When these antimicrotubule agents were included in the incubations, degradation of the apolipoproteins of [ 125 I]iodo-LDL and [ 125 I]iodo-HDL by the luteal cells was inhibited by 50-85% compared to untreated control values. Maximum inhibitory effects were observed when the cells were preincubated with the inhibitor for at least 4 h at 37 C before treatment with the labeled lipoprotein. Lipoprotein-stimulated progesterone production by luteal cells was also inhibited by 50% or more in the presence of antimicrotubule agents. However, basal and hCG-stimulated progesterone production were unaffected by these inhibitors. The binding of [ 125 I]iodo-LDL and [ 125 I]iodo-HDL to luteal cell plasma membrane receptors was not affected by the microtubule inhibitors. Although binding was unaffected and degradation was impaired in the presence of the inhibitors, there was no detectable accumulation of undegraded lipoprotein within the cells during the 24 h of study

  3. Cholesteryl ester transfer activity in plasma measured by using solid-phase-bound high-density lipoprotein

    International Nuclear Information System (INIS)

    Sparks, D.L.; Frohlich, J.; Cullis, P.; Pritchard, P.H.

    1987-01-01

    We studied the ability of lipid-transfer factors in plasma to promote transfer, to endogenous lipoproteins, of [ 3 H]cholesteryl ester from high-density lipoprotein (HDL) covalently bound to Sepharose 4B beads. After incubation for 2 h at 37 degrees C, 12 to 14% of the [ 3 H]cholesteryl ester had been transferred to the lipoproteins of the plasma, in the proportions 57% to HDL and 43% to low- and very-low-density lipoproteins. This process was a function of the amount of plasma present and was stimulated by addition of partly purified lipid-transfer protein. Transfer also depended on the concentration of donor HDL but was independent of the amount of acceptor lipoprotein. This simple evaluation of cholesteryl ester transfer does not require removal of lipoproteins from the plasma before incubation

  4. Large-scale preparation of the homogeneous LolA–lipoprotein complex and efficient in vitro transfer of lipoproteins to the outer membrane in a LolB-dependent manner

    OpenAIRE

    Watanabe, Shoji; Oguchi, Yuki; Yokota, Naoko; Tokuda, Hajime

    2007-01-01

    An ATP-binding cassette transporter LolCDE complex of Escherichia coli releases lipoproteins destined to the outer membrane from the inner membrane as a complex with a periplasmic chaperone, LolA. Interaction of the LolA–lipoprotein complex with an outer membrane receptor, LolB, then causes localization of lipoproteins to the outer membrane. As far as examined, formation of the LolA–lipoprotein complex strictly depends on ATP hydrolysis by the LolCDE complex in the presence of LolA. It has be...

  5. Low-density lipoprotein apheresis: an evidence-based analysis.

    Science.gov (United States)

    2007-01-01

    To assess the effectiveness and safety of low-density lipoprotein (LDL) apheresis performed with the heparin-induced extracorporeal LDL precipitation (HELP) system for the treatment of patients with refractory homozygous (HMZ) and heterozygous (HTZ) familial hypercholesterolemia (FH). BACKGROUND ON FAMILIAL HYPERCHOLESTEROLEMIA: Familial hypercholesterolemia is a genetic autosomal dominant disorder that is caused by several mutations in the LDL-receptor gene. The reduced number or absence of functional LDL receptors results in impaired hepatic clearance of circulating low-density lipoprotein cholesterol (LDL-C) particles, which results in extremely high levels of LDL-C in the bloodstream. Familial hypercholesterolemia is characterized by excess LDL-C deposits in tendons and arterial walls, early onset of atherosclerotic disease, and premature cardiac death. Familial hypercholesterolemia occurs in both HTZ and HMZ forms. Heterozygous FH is one of the most common monogenic metabolic disorders in the general population, occurring in approximately 1 in 500 individuals. Nevertheless, HTZ FH is largely undiagnosed and an accurate diagnosis occurs in only about 15% of affected patients in Canada. Thus, it is estimated that there are approximately 3,800 diagnosed and 21,680 undiagnosed cases of HTZ FH in Ontario. In HTZ FH patients, half of the LDL receptors do not work properly or are absent, resulting in plasma LDL-C levels 2- to 3-fold higher than normal (range 7-15mmol/L or 300-500mg/dL). Most HTZ FH patients are not diagnosed until middle age when either they or one of their siblings present with symptomatic coronary artery disease (CAD). Without lipid-lowering treatment, 50% of males die before the age of 50 and 25% of females die before the age of 60, from myocardial infarction or sudden death. In contrast to the HTZ form, HMZ FH is rare (occurring in 1 case per million persons) and more severe, with a 6- to 8-fold elevation in plasma LDL-C levels (range 15-25mmol

  6. Genetic analysis of intracapillary glomerular lipoprotein deposits in aging mice.

    Directory of Open Access Journals (Sweden)

    Gerda A Noordmans

    Full Text Available Renal aging is characterized by functional and structural changes like decreased glomerular filtration rate, and glomerular, tubular and interstitial damage. To gain insight in pathways involved in renal aging, we studied aged mouse strains and used genetic analysis to identify genes associated with aging phenotypes.Upon morphological screening in kidneys from 20-month-old mice from 26 inbred strains we noted intracapillary PAS-positive deposits. The severity of these deposits was quantified by scoring of a total of 50 glomeruli per section (grade 0-4. Electron microscopy and immunohistochemical staining for apoE, apoB, apoA-IV and perilipin-2 was performed to further characterize the lesions. To identify loci associated with these PAS-positive intracapillary glomerular deposits, we performed haplotype association mapping.Six out of 26 mouse strains showed glomerular PAS-positive deposits. The severity of these deposits varied: NOD(0.97, NZW(0.41, NON(0.30, B10(0.21, C3 H(0.9 and C57BR(0.7. The intracapillary deposits were strongly positive for apoE and weakly positive for apoB and apoA-IV. Haplotype association mapping showed a strong association with a 30-Kb haplotype block on Chr 1 within the Esrrg gene. We investigated 1 Mb on each site of this region, which includes the genes Spata17, Gpatch2, Esrrg, Ush2a and Kctd3.By analyzing 26 aged mouse strains we found that some strains developed an intracapillary PAS and apoE-positive lesion and identified a small haplotype block on Chr 1 within the Esrrg gene to be associated with these lipoprotein deposits. The region spanning this haplotype block contains the genes Spata17, Gpatch2, Esrrg, Ush2a and Kctd3, which are all highly expressed in the kidney. Esrrg might be involved in the evolvement of these glomerular deposits by influencing lipid metabolism and possibly immune reponses.

  7. Functional outcome in young adult ischemic stroke: impact of lipoproteins.

    Science.gov (United States)

    Putaala, J; Strbian, D; Mustanoja, S; Haapaniemi, E; Kaste, M; Tatlisumak, T

    2013-01-01

    To determine the functional outcome in a cohort of young adults with ischemic stroke patients, focusing on components of lipid profile. In our registry including consecutive patients with first-ever ischemic stroke aged 15-49 from 1994 to 2007, we analyzed predictors of 3-month functional outcome (modified Rankin Scale, mRS). Infarct size fell into small, medium, large posterior, or large anterior. Stroke severity was assessed with NIH Stroke Scale (NIHSS). Serum lipids were measured within 72 h after admission. Binary, multinomial ordinal, and Poisson regressions allowed revealing factors associated with size of infarct, stroke severity, and unfavorable outcome or death (mRS, 2-6) or mRS as an ordinal measure. In the 968 patients included (mean age, 41.3 ± 7.6; 62.6% men; 49.5% with mRS 0-1), factors associated with unfavorable outcome after multivariable analysis were increasing age (odds ratio, 1.03 per year; 95% confidence interval, 1.01-1.05), higher NIHSS score (1.23 per point, 1.17-1.29), large anterior (4.37, 2.26-8.42) or posterior (1.73, 1.05-2.85) infarcts, bilateral lesions (2.28, 1.30-3.98), internal carotid artery dissection (ICAD) (3.65, 1.41-9.47), and inversely high-density lipoprotein (HDL) levels (0.58 per unit increase, 0.38-0.86). Increasing HDL associated with smaller infarct size (0.71, 0.51-0.98). Both higher total and HDL cholesterol associated with lower NIHSS score (0.96, 0.93-0.98 for total cholesterol and 0.82, 0.75-0.88 for HDL) and lower 3-month mRS (0.87, 0.78-0.97 for total cholesterol and 0.65, 0.47-0.90 for HDL). In addition to known prognosticators, ICAD and lower HDL levels were independently associated with adverse clinical outcomes in our young adult stroke cohort. © 2012 John Wiley & Sons A/S.

  8. Human endothelial progenitor cells internalize high-density lipoprotein.

    Directory of Open Access Journals (Sweden)

    Kaemisa Srisen

    Full Text Available Endothelial progenitor cells (EPCs originate either directly from hematopoietic stem cells or from a subpopulation of monocytes. Controversial views about intracellular lipid traffic prompted us to analyze the uptake of human high density lipoprotein (HDL, and HDL-cholesterol in human monocytic EPCs. Fluorescence and electron microscopy were used to investigate distribution and intracellular trafficking of HDL and its associated cholesterol using fluorescent surrogates (bodipy-cholesterol and bodipy-cholesteryl oleate, cytochemical labels and fluorochromes including horseradish peroxidase and Alexa Fluor® 568. Uptake and intracellular transport of HDL were demonstrated after internalization periods from 0.5 to 4 hours. In case of HDL-Alexa Fluor® 568, bodipy-cholesterol and bodipy-cholesteryl oleate, a photooxidation method was carried out. HDL-specific reaction products were present in invaginations of the plasma membrane at each time of treatment within endocytic vesicles, in multivesicular bodies and at longer periods of uptake, also in lysosomes. Some HDL-positive endosomes were arranged in form of "strings of pearl"- like structures. HDL-positive multivesicular bodies exhibited intensive staining of limiting and vesicular membranes. Multivesicular bodies of HDL-Alexa Fluor® 568-treated EPCs showed multilamellar intra-vacuolar membranes. At all periods of treatment, labeled endocytic vesicles and organelles were apparent close to the cell surface and in perinuclear areas around the Golgi apparatus. No HDL-related particles could be demonstrated close to its cisterns. Electron tomographic reconstructions showed an accumulation of HDL-containing endosomes close to the trans-Golgi-network. HDL-derived bodipy-cholesterol was localized in endosomal vesicles, multivesicular bodies, lysosomes and in many of the stacked Golgi cisternae and the trans-Golgi-network Internalized HDL-derived bodipy-cholesteryl oleate was channeled into the lysosomal

  9. Phenotypic Characterization of Genetically Lowered Human Lipoprotein(a) Levels

    Science.gov (United States)

    Emdin, Connor A.; Khera, Amit V.; Natarajan, Pradeep; Klarin, Derek; Won, Hong-Hee; Peloso, Gina M.; Stitziel, Nathan O.; Nomura, Akihiro; Zekavat, Seyedeh M.; Bick, Alexander G.; Gupta, Namrata; Asselta, Rosanna; Duga, Stefano; Merlini, Piera Angelica; Correa, Adolfo; Kessler, Thorsten; Wilson, James G.; Bown, Matthew J.; Hall, Alistair S.; Braund, Peter S.; Samani, Nilesh J.; Schunkert, Heribert; Marrugat, Jaume; Elosua, Roberto; McPherson, Ruth; Farrall, Martin; Watkins, Hugh; Willer, Cristen; Abecasis, Gonçalo R.; Felix, Janine F.; Vasan, Ramachandran S.; Lander, Eric; Rader, Daniel J.; Danesh, John; Ardissino, Diego; Gabriel, Stacey; Saleheen, Danish; Kathiresan, Sekar

    2017-01-01

    BACKGROUND Genomic analyses have suggested that the LPA gene and its associated plasma biomarker, lipoprotein(a) (Lp[a]), represent a causal risk factor for coronary heart disease (CHD). As such, lowering Lp(a) has emerged as a therapeutic strategy. Beyond target identification, human genetics may contribute to the development of new therapies by defining the full spectrum of beneficial and adverse consequences and by developing a dose-response curve of target perturbation. OBJECTIVES We attempted to establish the full phenotypic impact of LPA gene variation and to estimate a dose-response curve between genetically altered plasma Lp(a) and risk for CHD. METHODS We leveraged genetic variants at the LPA gene from 3 data sources: individual-level data from 112,338 participants in the UK Biobank; summary association results from large-scale genome-wide association studies; and LPA gene sequencing results from cases with and controls free of CHD. RESULTS One standard deviation genetically lowered Lp(a) level was associated with 29% lower risk of CHD (odds ratio [OR]: 0.71; 95% confidence interval [CI]: 0.69 to 0.73), 31% lower risk of peripheral vascular disease (OR: 0.69; 95% CI: 0.59 to 0.80), 13% lower risk of stroke (OR: 0.87; 95% CI: 0.79 to 0.96), 17% lower risk of heart failure (OR: 0.83; 95% CI: 0.73 to 0.94), and 37% lower risk of aortic stenosis (OR: 0.63; 95% CI: 0.47 to 0.83). We observed no association with 31 other disorders including type 2 diabetes and cancer. Variants that led to gain of LPA gene function increased risk for CHD whereas those that led to loss of gene function reduced CHD risk. CONCLUSIONS Beyond CHD, genetically lowered Lp(a) is associated with a lower risk of peripheral vascular disease, stroke, heart failure, and aortic stenosis. As such, pharmacological lowering of plasma Lp(a) may impact a range of atherosclerosis-related diseases. PMID:28007139

  10. Genes encoding two lipoproteins in the leuS-dacA region of the Escherichia coli chromosome

    International Nuclear Information System (INIS)

    Takase, I.; Ishino, F.; Wachi, M.; Kamata, H.; Doi, M.; Asoh, S.; Matsuzawa, H.; Ohta, T.; Matsuhashi, M.

    1987-01-01

    The coding of two rare lipoproteins by two genes, rlpA and rlpB, located in the leuS-dacA region (15 min) on the Escherichia coli chromosome was demonstrated by expression of subcloned genes in a maxicell system. The formation of these two proteins was inhibited by globomycin, which is an inhibitor of the signal peptidase for the known lipoproteins of E. coli. In each case, this inhibition was accompanied by formation of a new protein, which showed a slightly lower mobility on sodium dodecyl sulfate-polyacrylamide gel electrophoresis and which we suppose to be a prolipoprotein with an N-terminal signal peptide sequence similar to those of the bacterial major lipoproteins and lysis proteins of some bacteriocins. The incorporation of 3 H-labeled palmitate and glycerol into the two lipoproteins was also observed. Sequencing of DNA showed that the two lipoprotein genes contained sequences that could code for signal peptide sequences of 17 amino acids (rlpA lipoprotein) and 18 amino acids (rlpB lipoprotein). The deduced sequences of the mature peptides consisted of 345 amino acids (M/sub r/ 35,615, rlpA lipoprotein) and 175 amino acids (M/sub r/ 19,445, rlpB lipoprotein), with an N-terminal cysteine to which thioglyceride and N-fatty acyl residues may be attached. These two lioproteins may be important in duplication of the cells

  11. Insulin receptor-related receptor as an extracellular pH sensor involved in the regulation of acid-base balance.

    Science.gov (United States)

    Petrenko, Alexander G; Zozulya, Sergey A; Deyev, Igor E; Eladari, Dominique

    2013-10-01

    Recent studies of insulin receptor-related receptor (IRR) revealed its unusual property to activate upon extracellular application of mildly alkaline media, pH>7.9. The activation of IRR with hydroxyl anion has typical features of ligand-receptor interaction; it is specific, dose-dependent, involves the IRR extracellular domain and is accompanied by a major conformational change. IRR is a member of the insulin receptor minifamily and has been long viewed as an orphan receptor tyrosine kinase since no peptide or protein agonist of IRR was found. In the evolution, IRR is highly conserved since its divergence from the insulin and insulin-like growth factor receptors in amphibia. The latter two cannot be activated by alkali. Another major difference between them is that unlike ubiquitously expressed insulin and insulin-like growth factor receptors, IRR is found in specific sets of cells of only some tissues, most of them being exposed to extracorporeal liquids of extreme pH. In particular, largest concentrations of IRR are in beta-intercalated cells of the kidneys. The primary physiological function of these cells is to excrete excessive alkali as bicarbonate into urine. When IRR is removed genetically, animals loose the property to excrete bicarbonate upon experimentally induced alkalosis. In this review, we will discuss the available in vitro and in vivo data that support the hypothesis of IRR role as a physiological alkali sensor that regulates acid-base balance. This article is part of a Special Issue entitled: Emerging recognition and activation mechanisms of receptor tyrosine kinases. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Maternal-fetal cholesterol transport in the second half of mouse pregnancy does not involve LDL receptor-related protein 2.

    Science.gov (United States)

    Zwier, M V; Baardman, M E; van Dijk, T H; Jurdzinski, A; Wisse, L J; Bloks, V W; Berger, R M F; DeRuiter, M C; Groen, A K; Plösch, T

    2017-08-01

    LDL receptor-related protein type 2 (LRP2) is highly expressed on both yolk sac and placenta. Mutations in the corresponding gene are associated with severe birth defects in humans, known as Donnai-Barrow syndrome. We here characterized the contribution of LRP2 and maternal plasma cholesterol availability to maternal-fetal cholesterol transport and fetal cholesterol levels in utero in mice. Lrp2 +/- mice were mated heterozygously to yield fetuses of all three genotypes. Half of the dams received a 0.5% probucol-enriched diet during gestation to decrease maternal HDL cholesterol. At E13.5, the dams received an injection of D7-labelled cholesterol and were provided with 1- 13 C acetate-supplemented drinking water. At E16.5, fetal tissues were collected and maternal cholesterol transport and fetal synthesis quantified by isotope enrichments in fetal tissues by GC-MS. The Lrp2 genotype did not influence maternal-fetal cholesterol transport and fetal cholesterol. However, lowering of maternal plasma cholesterol levels by probucol significantly reduced maternal-fetal cholesterol transport. In the fetal liver, this was associated with increased cholesterol synthesis rates. No indications were found for an interaction between the Lrp2 genotype and maternal probucol treatment. Maternal-fetal cholesterol transport and endogenous fetal cholesterol synthesis depend on maternal cholesterol concentrations but do not involve LRP2 in the second half of murine pregnancy. Our results suggest that the mouse fetus can compensate for decreased maternal cholesterol levels. It remains a relevant question how the delicate system of cholesterol transport and synthesis is regulated in the human fetus and placenta. © 2016 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

  13. Inhibitory effects of azole-type fungicides on interleukin-17 gene expression via retinoic acid receptor-related orphan receptors α and γ

    Science.gov (United States)

    Kojima, Hiroyuki; Muromoto, Ryuta; Takahashi, Miki; Takeuchi, Shinji; Takeda, Yukimasa; Jetten, Anton M.; Matsuda, Tadashi

    2013-01-01

    The retinoic acid receptor-related orphan receptors α and γ (RORα and RORγ), are key regulators of helper T (Th)17 cell differentiation, which is involved in the innate immune system and autoimmune disorders. However, it remains unclear whether environmental chemicals, including pesticides, have agonistic and/or antagonistic activity against RORα/γ. In this study, we investigated the RORα/γ activity of several azole-type fungicides, and the effects of these fungicides on the gene expression of interleukin (IL)-17, which mediates the function of Th17 cells. In the ROR-reporter gene assays, five azole-type fungicides (imibenconazole, triflumizole, hexaconazole, tetraconazole and imazalil) suppressed RORα- and/or RORγ-mediated transcriptional activity as did benzenesulphonamide T0901317, a ROR inverse agonist and a liver X receptor (LXR) agonist. In particular, imibenconazole, triflumizole and hexaconazole showed RORγ inverse agonistic activity at concentrations of 10−6 M. However, unlike T0901317, these fungicides failed to show any LXRα/β agonistic activity. Next, five azole-type fungicides, showing ROR inverse agonist activity, were tested on IL-17 mRNA expression in mouse T lymphoma EL4 cells treated with phorbol myristate acetate and ionomycin. The quantitative RT-PCR analysis revealed that these fungicides suppressed the expression of IL-17 mRNA without effecting RORα and RORγ mRNA levels. In addition, the inhibitory effect of imibenconazole as well as that of T0901317 was absorbed in RORα/γ-knocked down EL4 cells. Taken together, these results suggest that some azole-type fungicides inhibit IL-17 production via RORα/γ. This also provides the first evidence that environmental chemicals can act as modulators of IL-17 expression in immune cells. PMID:22289359

  14. Cultured human astrocytes secrete large cholesteryl ester- andtriglyceride-rich lipoproteins along with endothelial lipase

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Lin; Liu, Yanzhu; Forte, Trudy M.; Chisholm, Jeffrey W.; Parks, John S.; Shachter, Neil S.

    2003-12-01

    We cultured normal human astrocytes and characterized their secreted lipoproteins. Human astrocytes secreted lipoproteins in the size range of plasma VLDL (Peak 1), LDL (Peak 2), HDL (Peak 3) and a smaller peak (Peak 4), as determined by gel filtration chromatography, nondenaturing gradient gel electrophoresis and transmission electron microscopy. Cholesterol enrichment of astrocytes led to a particular increase in Peak 1. Almost all Peak 2, 3 and 4 cholesterol and most Peak 1 cholesterol was esterified (unlike mouse astrocyte lipoproteins, which exhibited similar peaks but where cholesterol was predominantly non-esterified). Triglycerides were present at about 2/3 the level of cholesterol. LCAT was detected along with two of its activators, apolipoprotein (apo) A-IV and apoC-I. ApoA-I and apoA-II mRNA and protein were absent. ApoJ was present equally in all peaks but apoE was present predominantly in peaks 3 and 4. ApoB was not detected. The electron microscopic appearance of Peak 1 lipoproteins suggested partial lipolysis leading to the detection of a heparin-releasable triglyceride lipase consistent with endothelial lipase. The increased neuronal delivery of lipids from large lipoprotein particles, for which apoE4 has greater affinity than does apoE3, may be a mechanism whereby the apoE {var_epsilon}4 allele contributes to neurodegenerative risk.

  15. Consumption of nonfat milk results in a less atherogenic lipoprotein profile: a pilot study.

    Science.gov (United States)

    Hidaka, Hiroya; Takiwaki, Masaki; Yamashita, Mine; Kawasaki, Kenji; Sugano, Mitsutoshi; Honda, Takayuki

    2012-01-01

    An increase in plasma low-density lipoprotein (LDL) is a well-known risk factor in the development of atherosclerosis. Dairy consumption may lower the risk of atherosclerosis; however, studies on the effects of milk on cardiovascular risk factors are still scarce. We were interested in investigating whether the intake of milk improves the atherogenic lipoprotein profile. We investigated the effects of consuming whole or nonfat milk on plasma lipoprotein composition in healthy Japanese subjects as a pilot study. Normolipidemic subjects consumed 500 ml of whole milk (whole milk group; n=7) or nonfat milk (nonfat milk group; n=7) every day for 2 weeks. The consumption of nonfat milk resulted in a lowering of plasma triglyceride (TG) and phospholipid levels and TG level in high-density lipoprotein (HDL) and increased the plasma apolipoprotein (apo) C-III level. In addition, the TG/cholesterol ratios in HDL and LDL were significantly decreased, and LDL particles became larger. In contrast, the only changes observed following whole milk consumption were increases in the plasma levels of apoC-III and apoE. These findings suggest that consumption of nonfat milk, but not whole milk, may result in a less atherogenic lipoprotein profile, and that the constituents of nonfat milk may improve lipid metabolism.

  16. Relationship between Serum Lipoprotein Ratios and Insulin Resistance in Polycystic Ovary Syndrome

    Directory of Open Access Journals (Sweden)

    Shou-Kui Xiang

    2012-01-01

    Full Text Available Objective. To investigate the association between serum lipoprotein ratios and insulin resistance in women with polycystic ovarian syndrome (PCOS. Methods. 105 PCOS patients and 109 controls were randomly enrolled in the study. Serum levels of luteinizing hormone (LH, follicle-stimulating hormone (FSH, estradiol (E2, total testosterone (T, fasting glucose (FBG, fasting insulin (FINS, serum triglycerides (TG, total cholesterol (TC, high-density lipoprotein (HDL-C, and low-density lipoprotein (LDL-C levels were checked, and then TG/HDL-C ratio, TC/HDL-C, ratio and LDL-C/HDL-C ratio were calculated. The homeostasis model assessment of insulin resistance (HOMA-IR was used to calculate the insulin resistance. Results. All lipoprotein ratios were significantly higher in PCOS patients as compared to healthy controls (<0.05. TG/HDL-C ratio, TC/HDL-C ratio, and LDL-C/HDL-C ratio were significantly correlated with HOMA-IR (<0.05. The ROC curve demonstrated that TC/HDL-C ratio had higher sensitivity and specificity in diagnosing PCOS with insulin resistance. Conclusion. This study demonstrates that serum lipoprotein ratio significantly correlates with insulin resistance and can be used as the marker of insulin resistance in PCOS patients.

  17. Structure and motion of phospholipids in human plasma lipoproteins. A 31P NMR study

    International Nuclear Information System (INIS)

    Fenske, D.B.; Chana, R.S.; Parmar, Y.I.; Treleaven, W.D.; Cushley, R.J.

    1990-01-01

    The structure and motion of phospholipids in human plasma lipoproteins have been studied by using 31 P NMR. Lateral diffusion coefficients, D T , obtained from the viscosity dependence of the 31 P NMR line widths, were obtained for very low density lipoprotein (VLDL), low-density lipoprotein (LDL), high-density lipoproteins (HDL 2 , HDL 3 ), and egg PC/TO microemulsions at 25 degree C, for VLDL at 40 degree C, and for LDL at 45 degree C. In order to prove the orientation and/or order of the phospholipid head-group, estimates of the residual chemical shift anistropy, Δσ, have been obtained for all the lipoproteins and the microemulsions from the viscosity and field dependence for the 31 P NMR line widths. These results suggest differences in the orientation and/or ordering of the head-group in the HDLs. The dynamic behavior of the phosphate moiety in LDL and HDL 3 has been obtained from the temperature dependence of the 31 P spin-lattice relaxation rates. Values of the correlation time for phosphate group reorientation and the activation energy for the motion are nearly identical in LDL and HDL 3 and are similar to values obtained for phospholipid bilayers. This argues against long-lived protein-lipid interactions being the source of either the slow diffusion in LDL or the altered head-group orientation in the HDLs

  18. Investigations on the transport and metabolism of high density lipoprotein cholesteryl esters in African green monkeys

    International Nuclear Information System (INIS)

    Sorci-Thomas, M.G.

    1984-01-01

    The metabolic fate of circulating high density lipoprotein cholesteryl esters was studied in African green monkeys to determine the significance of the lipid transfer reaction on the catabolism of lipoprotein cholesteryl esters. A method of doubly labeling both moieties of lipoprotein cholesteryl esters with [ 3 He]cholesteryl oleate and cholesteryl [ 14 C]oleate was developed for the purpose of studying plasma cholesteryl ester metabolism in vivo. In these studies the total plasma [ 3 He]cholesterol turnover resulted in production rates, which ranged from 10-17 mg/kg day, similar to previously reported values in African green monkeys and in normal lipoproteinemic humans. In contrast to the production rates calculated from the decay of plasma 3 He-radioactivity, the production rates calculated from lipoproteins labeled with cholesteryl [ 14 C]oleate were approximately 2-3 times greater. In addition to these studies, a plasma cholesteryl ester transacylation activity was demonstrated in vitro when HDL containing doubly labeled cholesteryl esters were incubated with fresh plasma. These results demonstrated that high density lipoprotein cholesteryl esters undergo transacylation in vitro, resulting in release and reesterification of free [ 3 H]cholesterol

  19. Early incorporation of cell-derived cholesterol into pre-beta-migrating high-density lipoprotein

    International Nuclear Information System (INIS)

    Castro, G.R.; Fielding, C.J.

    1988-01-01

    Cultures of human skin fibroblasts were labeled to high cholesterol specific activity with [ 3 H]cholesterol and incubated briefly (1-3 min) with normal human plasma. The plasma was fractionated by two-dimensional agarose-polyacrylamide gel electrophoresis and the early appearance of cholesterol label among plasma lipoproteins determined. A major part of the label at 1-min incubation was in a pre-beta-migrating apo A-I lipoprotein fraction with a molecular weight of ca. 70,000. Label was enriched about 30-fold in this fraction relative to its content of apo A-I (1-2% of total apo A-I). The proportion of label in this lipoprotein was strongly correlated with its concentration in plasma. Further incubation (2 min) in the presence of unlabeled cells demonstrated transfer of label from this fraction to a higher molecular weight pre-beta apo A-I species, to low-density lipoprotein, and to the alpha-migrating apo A-I that made up the bulk (96%) of total apo A-I in plasma. The data suggest that a significant part of cell-derived cholesterol is transferred specifically to a pre-beta-migrating lipoprotein A-I species as part of a cholesterol transport transfer sequence in plasma

  20. Impact of hormonal contraception and weight loss on high-density lipoprotein cholesterol efflux and lipoprotein particles in women with polycystic ovary syndrome.

    Science.gov (United States)

    Dokras, Anuja; Playford, Martin; Kris-Etherton, Penny M; Kunselman, Allen R; Stetter, Christy M; Williams, Nancy I; Gnatuk, Carol L; Estes, Stephanie J; Sarwer, David B; Allison, Kelly C; Coutifaris, Christos; Mehta, Nehal; Legro, Richard S

    2017-05-01

    To study the effects of oral contraceptive pills (OCP), the first-line treatment for PCOS, on high-density lipoprotein cholesterol (HDL-C) function (reverse cholesterol efflux capacity) and lipoprotein particles measured using nuclear magnetic resonance spectroscopy in obese women. Secondary analysis of a randomized controlled trial (OWL-PCOS) of OCP or Lifestyle (intensive Lifestyle modification) or Combined (OCP + Lifestyle) treatment groups for 16 weeks. Eighty-seven overweight/obese women with PCOS at two academic centres. Change in HDL-C efflux capacity and lipoprotein particles. High-density lipoprotein cholesterol efflux capacity increased significantly at 16 weeks in the OCP group [0·11; 95% confidence interval (CI) 0·03, 0·18, P = 0·008] but not in the Lifestyle (P = 0·39) or Combined group (P = 0·18). After adjusting for HDL-C and TG levels, there was significant mean change in efflux in the Combined group (0·09; 95% CI 0·01, 0·15; P = 0·01). Change in HDL-C efflux correlated inversely with change in serum testosterone (r s = -0·21; P = 0·05). In contrast, OCP use induced an atherogenic low-density lipoprotein cholesterol (LDL-C) profile with increase in small (P = 0·006) and large LDL-particles (P = 0·002). Change in small LDL-particles correlated with change in serum testosterone (r s = -0·31, P = 0·009) and insulin sensitivity index (ISI; r s = -0·31, P = 0·02). Both Lifestyle and Combined groups did not show significant changes in the atherogenic LDL particles. Oral contraceptive pills use is associated with improved HDL-C function and a concomitant atherogenic LDL-C profile. Combination of a Lifestyle program with OCP use improved HDL-C function and mitigated adverse effects of OCP on lipoproteins. Our study provides evidence for use of OCP in overweight/obese women with PCOS when combined with Lifestyle changes. © 2017 John Wiley & Sons Ltd.

  1. Determining the risk of cardiovascular disease using ion mobility of lipoproteins

    Science.gov (United States)

    Benner, W. Henry; Krauss, Ronald M.; Blanche, Patricia J.

    2010-05-11

    A medical diagnostic method and instrumentation system for analyzing noncovalently bonded agglomerated biological particles is described. The method and system comprises: a method of preparation for the biological particles; an electrospray generator; an alpha particle radiation source; a differential mobility analyzer; a particle counter; and data acquisition and analysis means. The medical device is useful for the assessment of human diseases, such as cardiac disease risk and hyperlipidemia, by rapid quantitative analysis of lipoprotein fraction densities. Initially, purification procedures are described to reduce an initial blood sample to an analytical input to the instrument. The measured sizes from the analytical sample are correlated with densities, resulting in a spectrum of lipoprotein densities. The lipoprotein density distribution can then be used to characterize cardiac and other lipid-related health risks.

  2. Lipophilic antioxidants and polyunsaturated fatty acids in lipoprotein classes: distribution and interaction

    DEFF Research Database (Denmark)

    Sunesen, V.H.; Weber, Christine; Hølmer, Gunhild Kofoed

    2001-01-01

    supplementations, but fish oil increased the amount of n-3 fatty acids at the expense of n-6 fatty acids. Conclusion: Lipoprotein distribution of CoQ(10) is markedly different from that of alpha -tocopherol, suggesting that they may be metabolised by distinct routes. alpha -Tocopherol is distributed similarly to n......Objective: To study the lipoprotein distribution of supplemented coenzyme Q(10) (CoQ(10)), vitamin E, and polyunsaturated fatty acids (PUFA). Design: Balanced three- period crossover study. Setting: University research unit. Subjects: Eighteen apparently healthy free-living non-smoking volunteers...... the first period and then after each period. Plasma and isolated lipoproteins were analysed for cholesterol, triacylglycerol, alpha- and gamma -tocopherol, CoQ(10), and fatty acid composition. Results: Significant (P

  3. Direct effects of fatty meals and adiposity on oxidised low-density lipoprotein.

    Science.gov (United States)

    Laguna-Camacho, Antonio; Alonso-Barreto, Arely S; Mendieta-Zerón, Hugo

    2015-01-01

    High-fat intake and high adiposity contribute to hyperlipaemia. In a hyperlipaemic state, lipoproteins infiltrate arterial wall where they are modified and cause an immune response characteristic of atherosclerosis. A small fraction of modified lipoproteins including oxidised low-density lipoprotein (ox-LDL) returns to circulation. The present study tracked high-fat meals during four weeks as to find effects of sustained frequency change on adiposity and ox-LDL. The findings indicated that changes in frequency of consumption of high-fat eating episodes correlated directly with changes in adiposity and ox-LDL. Hence the number of fatty meals consumed by people with overweight or obesity in few weeks could affect the atherogenic process. Copyright © 2015 Asian Oceanian Association for the Study of Obesity. Published by Elsevier Ltd. All rights reserved.

  4. Lipoprotein receptor LRP1 regulates leptin signaling and energy homeostasis in the adult central nervous system.

    Science.gov (United States)

    Liu, Qiang; Zhang, Juan; Zerbinatti, Celina; Zhan, Yan; Kolber, Benedict J; Herz, Joachim; Muglia, Louis J; Bu, Guojun

    2011-01-11

    Obesity is a growing epidemic characterized by excess fat storage in adipocytes. Although lipoprotein receptors play important roles in lipid uptake, their role in controlling food intake and obesity is not known. Here we show that the lipoprotein receptor LRP1 regulates leptin signaling and energy homeostasis. Conditional deletion of the Lrp1 gene in the brain resulted in an obese phenotype characterized by increased food intake, decreased energy consumption, and decreased leptin signaling. LRP1 directly binds to leptin and the leptin receptor complex and is required for leptin receptor phosphorylation and Stat3 activation. We further showed that deletion of the Lrp1 gene specifically in the hypothalamus by Cre lentivirus injection is sufficient to trigger accelerated weight gain. Together, our results demonstrate that the lipoprotein receptor LRP1, which is critical in lipid metabolism, also regulates food intake and energy homeostasis in the adult central nervous system.

  5. Lipoprotein receptor LRP1 regulates leptin signaling and energy homeostasis in the adult central nervous system.

    Directory of Open Access Journals (Sweden)

    Qiang Liu

    2011-01-01

    Full Text Available Obesity is a growing epidemic characterized by excess fat storage in adipocytes. Although lipoprotein receptors play important roles in lipid uptake, their role in controlling food intake and obesity is not known. Here we show that the lipoprotein receptor LRP1 regulates leptin signaling and energy homeostasis. Conditional deletion of the Lrp1 gene in the brain resulted in an obese phenotype characterized by increased food intake, decreased energy consumption, and decreased leptin signaling. LRP1 directly binds to leptin and the leptin receptor complex and is required for leptin receptor phosphorylation and Stat3 activation. We further showed that deletion of the Lrp1 gene specifically in the hypothalamus by Cre lentivirus injection is sufficient to trigger accelerated weight gain. Together, our results demonstrate that the lipoprotein receptor LRP1, which is critical in lipid metabolism, also regulates food intake and energy homeostasis in the adult central nervous system.

  6. Method of assessing a lipid-related health risk based on ion mobility analysis of lipoproteins

    Science.gov (United States)

    Benner, W. Henry; Krauss, Ronald M.; Blanche, Patricia J.

    2010-12-14

    A medical diagnostic method and instrumentation system for analyzing noncovalently bonded agglomerated biological particles is described. The method and system comprises: a method of preparation for the biological particles; an electrospray generator; an alpha particle radiation source; a differential mobility analyzer; a particle counter; and data acquisition and analysis means. The medical device is useful for the assessment of human diseases, such as cardiac disease risk and hyperlipidemia, by rapid quantitative analysis of lipoprotein fraction densities. Initially, purification procedures are described to reduce an initial blood sample to an analytical input to the instrument. The measured sizes from the analytical sample are correlated with densities, resulting in a spectrum of lipoprotein densities. The lipoprotein density distribution can then be used to characterize cardiac and other lipid-related health risks.

  7. Radiochemical and immunohistochemical detection of low density lipoprotein surface binding by lymphocytes

    International Nuclear Information System (INIS)

    Melzner, I.; Hambitzer, R.; Haferkamp, O.

    1983-01-01

    Human peripheral blood lymphocytes bind and take up low density lipoprotein (LDL) by receptor-mediated endocytosis. The binding of LDL was determiend by incubation with 125 I-LDL and an immunohistochemical assay. By both techniques a diminished rate of binding was found when cells were freshly isolated from the blood, but increased 5 to 10 fold when lymphocytes were incubated in lipoprotein-deficient medium for 72 hours. In addition, it was shown immunohistochemically that only few ceels showed an LDL-dependent fluorescent labelling: approximately 5 to 10 % of the freshly isolated lymphocytes and 40 to 50 % of the cells incubated for 72 hours under lipoprotein-free conditions. The present data indicate that not only the high affinity LDL receptor described by Goldstein and Braun may be involved in the uptake of cholesterol by lymphocytes, but also other binding sites, which may have immunological function in some lymphocyte subpopulations. (author)

  8. Vitamin D supplementation does not affect serum lipids and lipoproteins in Pakistani immigrants

    DEFF Research Database (Denmark)

    Andersen, Rikke; Brot, Christine; Mejborn, Heddie

    2009-01-01

    Potential long-term negative effects of increased vitamin D consumption are not thoroughly examined. The aim of this study was to investigate possible negative effects of vitamin D supplementation on serum lipids and lipoproteins. A 1-year long randomised double-blinded placebo-controlled interve......Potential long-term negative effects of increased vitamin D consumption are not thoroughly examined. The aim of this study was to investigate possible negative effects of vitamin D supplementation on serum lipids and lipoproteins. A 1-year long randomised double-blinded placebo......-cholesterol/HDL-cholesterol ratio, VLDL-cholesterol and triacylglycerol after daily supplementation with 10 or 20 g vitamin D for 1 year. In conclusion, increasing the vitamin D intake by 10–20 g per day for 1 year is safe for Pakistani immigrants with regards to serum lipids and lipoproteins....

  9. Serum lipoprotein (a) concentration in patients with nephrotic syndrome and its clinical implication.

    Science.gov (United States)

    Yang, X; Wang, H; Zhu, Z; Deng, A

    1998-01-01

    Serum lipoprotein(a) [Lp(a)] concentration was determined in 42 patients with primary nephrotic syndrome (NS) and the relationships between Lp (a) and plasma lipids, apolipoproteins, serum creatinine (Scr), albumin, urinary proteins (Upro) were also analyzed. The results showed that: (1) serum Lp(a) concentrations in the patients with NS were higher than those in healthy controls; (2) the levels of serum Lp(a) were correlated positively with total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), very low density lipoprotein cholesterol (VLDL-C), apolipoprotein B (Apo-B), Upros (Upro). It is concluded that the NS patients had the potential risk of suffering from coronary artery disease, glomerular sclerosis and thrombosis. The remission of NS may partially decrease the serum Lp(a) levels. Further studies are needed to explore the prevention and treatment of dislipedemia in patients with NS.

  10. Cardiac metabolism and mechanics are altered by genetic loss of lipoprotein triglyceride lipolysis.

    Science.gov (United States)

    Noh, Hye-Lim; Yamashita, Haruyo; Goldberg, Ira J

    2006-12-01

    Most circulating fatty acids are contained in lipoprotein triglycerides. For the heart to acquire these lipids, they must be broken down into free fatty acids via the enzyme lipoprotein lipase (LpL). Although it has long been known that hearts primarily use esterified fatty acids as fuel, different sources of fatty acids were thought to be interchangeable. By creating mice with neonatal and acute LpL deletion we showed that lipoprotein-derived fatty acids could not be replaced by albumin-associated free fatty acids. Loss of cardiac LpL forces the heart to increase its uptake of glucose, reduce fatty acid oxidation, and eventually leads to cardiac dysfunction. In contrast, cardiomyocyte specific overexpression of an anchored form of LpL leads to excess lipid uptake, induction of fatty acid oxidation genes, and dilated cardiomyopathy. Increasing lipid secretion from the heart or redirecting lipids to adipose tissue can alleviate this lipotoxic situation.

  11. Mice with chimeric livers are an improved model for human lipoprotein metabolism.

    Science.gov (United States)

    Ellis, Ewa C S; Naugler, Willscott Edward; Nauglers, Scott; Parini, Paolo; Mörk, Lisa-Mari; Jorns, Carl; Zemack, Helen; Sandblom, Anita Lövgren; Björkhem, Ingemar; Ericzon, Bo-Göran; Wilson, Elizabeth M; Strom, Stephen C; Grompe, Markus

    2013-01-01

    Rodents are poor model for human hyperlipidemias because total cholesterol and low density lipoprotein levels are very low on a normal diet. Lipoprotein metabolism is primarily regulated by hepatocytes and we therefore assessed whether chimeric mice extensively repopulated with human cells can model human lipid and bile acid metabolism. FRG [ F ah(-/-) R ag2(-/-)Il2r g (-/-)]) mice were repopulated with primary human hepatocytes. Serum lipoprotein lipid composition and distribution (VLDL, LDL, and HDL) was analyzed by size exclusion chromatography. Bile was analyzed by LC-MS or by GC-MS. RNA expression levels were measured by quantitative RT-PCR. Chimeric mice displayed increased LDL and VLDL fractions and a lower HDL fraction compared to wild type, thus significantly shifting the ratio of LDL/HDL towards a human profile. Bile acid analysis revealed a human-like pattern with high amounts of cholic acid and deoxycholic acid (DCA). Control mice had only taurine-conjugated bile acids as expcted, but highly repopulated mice had glycine-conjugated cholic acid as found in human bile. RNA levels of human genes involved in bile acid synthesis including CYP7A1, and CYP27A1 were significantly upregulated as compared to human control liver. However, administration of recombinant hFGF19 restored human CYP7A1 levels to normal. Humanized-liver mice showed a typical human lipoprotein profile with LDL as the predominant lipoprotein fraction even on a normal diet. The bile acid profile confirmed presence of an intact enterohepatic circulation. Although bile acid synthesis was deregulated in this model, this could be fully normalized by FGF19 administration. Taken together these data indicate that chimeric FRG-mice are a useful new model for human lipoprotein and bile-acid metabolism.

  12. Effects of soy bean on serum paraoxonase 1 activity and lipoproteins in hyperlipidemic postmenopausal women.

    Science.gov (United States)

    Shidfar, Farzad; Ehramphosh, Elham; Heydari, Iraj; Haghighi, Ladan; Hosseini, Sharieh; Shidfar, Shahrzad

    2009-05-01

    Because of an unfavorable serum lipoprotein profile, postmenopausal women are at risk of cardiovascular disease. Soy protein may help protect against these risk factors, although its effect on paraoxonase 1 (PON1) is not clear. The aim of the present study was to determine the effects of soy protein on serum concentration of lipoproteins and PON1 activity in hypercholesterolemic postmenopausal women. In a double-blind randomized clinical trial with a parallel design, 52 hypercholesterolemic postmenopausal women were randomly assigned to 50 g/day soy protein containing 164 mg isoflavones or placebo, for 10 weeks. Serum lipoproteins and PON1 activity were measured at baseline and at the 10th week. There was significant increase in PON1 activity (P=0.029) and a significant decrease in low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC), LDL-C/high-density lipoprotein cholesterol (HDL-C), triacylglycerol/HDL-C and TC/HDL-C in the soy group compared with the placebo group (P=0.001, P=0.008, P=0.012, P=0.04 and P=0.029, respectively) at the end of the study. Similarly, PON1 activity was significantly increased (P=0.015) and LDL-C, TC, LDL-C/HDL-C, triacylglycerol/HDL-C and TC/HDL-C were significantly decreased (P=0.001, P=0.002, P=0.001, P=0.016 and P=0.001) at the end of the study compared with the beginning value in soy group. Soy protein reduces the cardiovascular disease risk in postmenopausal women because of both modest reductions in serum lipoproteins and an increase in PON1 activity.

  13. A receptor-based biosensor for lipoprotein docking at the endothelial surface and vascular matrix.

    Science.gov (United States)

    Siegel, G; Malmsten, M; Klüssendorf, D; Michel, F

    2001-12-01

    Proteoheparan sulfate can be adsorbed to a methylated silica surface in a monomolecular layer via its transmembrane hydrophobic protein core domain. Due to electrostatic repulsion, its anionic glycosaminoglycan side chains are stretched out into the blood substitute solution, representing a receptor site for specific lipoprotein binding through basic amino acid-rich residues within their apolipoproteins. The binding process was studied by ellipsometric techniques showing that HDL has a high binding affinity to the receptor and a protective effect on interfacial heparan sulfate proteoglycan layers, with respect to LDL and Ca(2+) complexation. LDL was found to deposit strongly at the proteoheparan sulfate, particularly in the presence of Ca(2+), thus creating the complex formation "proteoglycan-low density lipoprotein-calcium". This ternary complex build-up may be interpreted as arteriosclerotic nanoplaque formation on the molecular level responsible for the arteriosclerotic primary lesion. On the other hand, HDL bound to heparan sulfate proteoglycan protected against LDL docking and completely suppressed calcification of the proteoglycan-lipoprotein complex. In addition, HDL and aqueous garlic extract were able to reduce the ternary complex deposition and to disintegrate HS-PG/LDL/Ca(2+) aggregates. Although much remains unclear regarding the mechanism of lipoprotein depositions at proteoglycan-coated surfaces, it seems clear that the use of such systems offers possibilities for investigating lipoprotein deposition at a "nanoscopic" level under close to physiological conditions. In particular, Ca(2+)-promoted LDL deposition and the protective effect of HDL, even at high Ca(2+) and LDL concentrations, agree well with previous clinical observations regarding risk and beneficial factors for early stages of atherosclerosis. Therefore, we believe that the system can be of some use in investigations, e.g. of the interplay between different lipoproteins in arteriosclerotic

  14. Blood lipid concentrations and lipoprotein patterns in captive and wild American black bears (Ursus americanus).

    Science.gov (United States)

    Frank, Nicholas; Elliott, Sarah B; Allin, Shawn B; Ramsay, Edward C

    2006-02-01

    To compare blood lipid concentrations and lipoprotein patterns for captive and wild American black bears (Ursus americanus). 7 captive and 9 wild adult (> or = 4 years old) black bears. Blood was collected from 2 groups of captive black bears (groups A and B) and 1 group of wild black bears (group C). Blood triglyceride (TG) and cholesterol concentrations were compared among groups. Plasma lipoproteins were isolated by use of a self-generating gradient of iodixanol, and lipoprotein patterns were compared between groups A and B. Captive bears (mean +/- SD, 187.8 +/- 44.4 kg) weighed significantly more than wild bears (mean, 104.8 +/- 41.4 kg), but mean body weight did not differ between groups A and B. Mean blood TG concentrations for groups B (216.8 +/- 16.0 mg/dL) and C (190.7 +/- 34.0 mg/dL) were significantly higher than that of group A (103.9 +/- 25.3 mg/dL). Mean blood cholesterol concentration was also significantly higher for group B (227.8 +/- 8.2 mg/dL) than for groups A (171.7 +/- 35.5 mg/dL) or C (190.8 +/- 26.8 mg/dL). Mean very-low-density lipoprotein TG and low-density lipoprotein cholesterol concentrations were 2- and 3-fold higher, respectively, for group B, compared with concentrations for group A. Blood lipid concentrations vary significantly among populations of black bears. Plasma lipoprotein patterns of captive bears differed significantly between colonies and may have reflected differences in diet or management practices.

  15. Purification of a sarcoplasmic reticulum protein that binds Ca2+ and plasma lipoproteins

    International Nuclear Information System (INIS)

    Hofmann, S.L.; Brown, M.S.; Lee, E.; Pathak, R.K.; Anderson, R.G.; Goldstein, J.L.

    1989-01-01

    A protein in the sarcoplasmic reticulum of rabbit skeletal and cardiac muscle was identified because of its ability to bind 125I-labeled low density lipoprotein (LDL) with high affinity after sodium dodecyl sulfate-polyacrylamide gel electrophoresis. This protein, referred to as the 165-kDa protein, is restricted to striated muscle. It was not detected in 14 other tissues, including several that contain smooth muscle, but it appears in rat L6 myoblasts when they differentiate into myocytes. Immunofluorescence and immunoelectron microscopic studies revealed that the protein is present throughout the sarcoplasmic reticulum and the terminal cisternae. It binds 45Ca2+ on nitrocellulose blots and stains metachromatically with Stains-all, a cationic dye that stains Ca2+-binding proteins. It does not appear to be a glycoprotein, and it appears slightly larger than the 160-kDa glycoprotein previously described in sarcoplasmic reticulum. The 165-kDa protein binds LDL, beta-migrating very low density lipoprotein, and a cholesterol-induced high density lipoprotein particle that contains apoprotein E as its sole apoprotein with much higher affinity than it binds high density lipoprotein. The protein is stable to boiling and to treatment with sodium dodecyl sulfate, but it becomes sensitive to these treatments when its cystine residues are reduced and alkylated. The protein was purified 1300-fold to apparent homogeneity from rabbit skeletal muscle membranes. It differs from the cell surface LDL receptor in that (1) its apparent molecular weight is not changed by reduction and alkylation; (2) it is present in Watanabe-heritable hyperlipidemic rabbits, which lack functional LDL receptors; (3) binding of lipoproteins is not inhibited by EDTA; and (4) it is located within the lumen of the sarcoplasmic reticulum where it has no access to plasma lipoproteins

  16. [3H]cholesteryl ester labeling and transfer among human and honhuman primate plasma lipoproteins

    International Nuclear Information System (INIS)

    Thomas, M.S.; Rudel, L.L.

    1983-01-01

    Aliquots of human and nonhuman primate plasma containing 5,5'-dithiobis (2-nitrobenzoic acid) were incubated at 37 0 C in tubes previously coated with trace amounts of tritium-labeled cholesteryl oleate ([ 3 H]CO). Initially, cholesteryl esters were transferred at a rapid rate into plasma after which the rate slowed. During 24 h of incubation, an average of 55% of the [ 3 H]CO transferred from the side of the tube into African green monkey plasma, 44% into human plasma and 21% into rat plasma. Greater than 98% of the radioactive ester transferred into plasma was found to be associated with plasma lipoproteins that were then rapidly separated using vertical rotor density gradient ultracentrifugation. In very low density lipoprotein (VLDL)-poor plasma after 30 min incubations, high density lipoproteins (HDL) contained most of the [ 3 H]CO while 5- to 24-h incubations resulted in increased labeling of low density proteins (LDL). In VLDL-rich plasma, it was found that in addition to the labeling of HDL, VLDL contained about 25% of the labeled cholesteryl esters after 30-min incubations and, as above, the proportion in LDL subsequently increased. Compositional analyses showed that intermediate-sized LDL (ILDL) were accumulating cholesteryl ester mass while transfer occurred. LDL labeled using this method were injected intravenously into monkeys and their removal from plasma was found to be similar to that found for LDL labeled in vivo. It was concluded that this method of plasma lipoprotein cholesteryl ester labeling, presumably a result of cholesteryl ester transfer protein activity, was efficient, resulted in lipoproteins labeled only in the cholesteryl ester moiety, and induced minimal modification of lipoprotein particles that did not alter their biological activity

  17. Novel lipoprotein density profiling in healthy dogs of various breeds, healthy miniature schnauzers, and miniature schnauzers with hyperlipidemia

    Science.gov (United States)

    2013-01-01

    Background Despite the importance of abnormalities in lipoprotein metabolism in clinical canine medicine, the fact that most previously used methods for lipoprotein profiling are rather laborious and time-consuming has been a major obstacle to the wide clinical application and use of lipoprotein profiling in this species. The aim of the present study was to assess the feasibility of a continuous lipoprotein density profile (CLPDP) generated within a bismuth sodium ethylenediaminetetraacetic acid (NaBiEDTA) density gradient to characterize and compare the lipoprotein profiles of healthy dogs of various breeds, healthy Miniature Schnauzers, and Miniature Schnauzers with primary hypertriacylglycerolemia. A total of 35 healthy dogs of various breeds with serum triacylglycerol (TAG) and cholesterol concentrations within their respective reference intervals were selected for use as a reference population. Thirty-one Miniature Schnauzers with serum TAG and cholesterol concentrations within their respective reference intervals and 31 Miniature Schnauzers with hypertriacylglyceridemia were also included in the study. Results The results suggest that CLPDP using NaBiEDTA provides unique diagnostic information in addition to measurements of serum TAG and cholesterol concentrations and that it is a useful screening method for dogs with suspected lipoprotein metabolism disorders. Using the detailed and continuous density distribution information provided by the CLPDP, important differences in lipoprotein profiles can be detected even among dogs that have serum TAG and cholesterol concentrations within the reference interval. Miniature Schnauzers with serum TAG and cholesterol concentrations within the reference interval had significantly different lipoprotein profiles than dogs of various other breeds. In addition, it was further established that specific lipoprotein fractions are associated with hypertriacylglyceridemia in Miniature Schnauzers. Conclusions The results of the

  18. Relationship Between Two Common Lipoprotein Lipase Variants and the Metabolic Syndrome and Its Individual Components

    DEFF Research Database (Denmark)

    Vishram, Julie K. K.; Hansen, Tine W; Torp-Pedersen, Christian

    2016-01-01

    BACKGROUND: Common lipoprotein lipase (LPL) variants are important determinants of triglycerides (TG) and high-density lipoprotein (HDL) cholesterol (C) concentrations. High TG/low HDL-C tend to cluster with hypertension, glucose intolerance, and abdominal obesity and comprise the metabolic...... syndrome (MetS). The role of LPL variants as a cause of MetS is unclear. This study investigated the relationship between two common LPL variants and the presence of MetS and its individual components. METHODS: Cross-sectional study, including 2348 Danish women (50.7%) and men, age 41-72 years, without...

  19. Transvascular low-density lipoprotein transport in patients with diabetes mellitus (type 2)

    DEFF Research Database (Denmark)

    Kornerup, Karen; Nordestgaard, Børge Grønne; Feldt-Rasmussen, Bo

    2002-01-01

    accumulation and, thus, atherosclerosis. METHODS AND RESULTS: We developed an in vivo method for measurement of transvascular transport of low density lipoprotein (LDL) and applied it in 16 patients with maturity-onset diabetes (type 2) and 29 healthy control subjects. Autologous 131I-labeled LDL...... plasma insulin levels in diabetic patients. CONCLUSIONS: Transvascular LDL transport may be increased in patients with type 2 diabetes. This suggests that lipoprotein flux into the arterial wall is increased in people with diabetes, possibly explaining the accelerated development of atherosclerosis....... in patients with diabetes and control subjects, respectively (P2.5%/h and 5.3+/-1.6%/h (P

  20. Triglyceride-rich lipoproteins as a causal factor for cardiovascular disease

    Directory of Open Access Journals (Sweden)

    Toth PP

    2016-05-01

    Full Text Available Peter P Toth1,2 1Ciccarone Center for the Prevention of Cardiovascular Disease, Johns Hopkins University School of Medicine, Baltimore, MD, 2Preventive Cardiology, CGH Medical Center, Sterling, IL, USA Abstract: Approximately 25% of US adults are estimated to have hypertriglyceridemia (triglyceride [TG] level ≥150 mg/dL [≥1.7 mmol/L]. Elevated TG levels are associated with increased cardiovascular disease (CVD risk, and severe hypertriglyceridemia (TG levels ≥500 mg/dL [≥5.6 mmol/L] is a well-established risk factor for acute pancreatitis. Plasma TG levels correspond to the sum of the TG content in TG-rich lipoproteins (TRLs; ie, very low-density lipoproteins plus chylomicrons and their remnants. There remains some uncertainty regarding the direct causal role of TRLs in the progression of atherosclerosis and CVD, with cardiovascular outcome studies of TG-lowering agents, to date, having produced inconsistent results. Although low-density lipoprotein cholesterol (LDL-C remains the primary treatment target to reduce CVD risk, a number of large-scale epidemiological studies have shown that elevated TG levels are independently associated with increased incidence of cardiovascular events, even in patients treated effectively with statins. Genetic studies have further clarified the causal association between TRLs and CVD. Variants in several key genes involved in TRL metabolism are strongly associated with CVD risk, with the strength of a variant's effect on TG levels correlating with the magnitude of the variant's effect on CVD. TRLs are thought to contribute to the progression of atherosclerosis and CVD via a number of direct and indirect mechanisms. They directly contribute to intimal cholesterol deposition and are also involved in the activation and enhancement of several proinflammatory, proapoptotic, and procoagulant pathways. Evidence suggests that non-high-density lipoprotein cholesterol, the sum of the total cholesterol carried by

  1. Enzymatic Modification of Plasma Low Density Lipoproteins in Rabbits: A Potential Treatment for Hypercholesterolemia

    Science.gov (United States)

    Labeque, Regine; Mullon, Claudy J. P.; Ferreira, Joao Paulo M.; Lees, Robert S.; Langer, Robert

    1993-04-01

    Phospholipase A_2 (EC 3.1.1.4) hydrolyzes certain phospholipids of low density lipoprotein (LDL). Plasma clearance of phospholipase A_2-modified human LDL is up to 17 times faster than that of native human LDL in hypercholesterolemic rabbits. Modification of blood lipoproteins of hypercholesterolemic rabbits was performed by using an extracorporeal circuit containing immobilized phospholipase A_2. After 90-min treatments, nearly 30% decreases in plasma cholesterol concentrations were observed. Erythrocyte, leukocyte, and platelet counts showed no net change after treatment. This technique does not require any fluid replacement or sorbent regeneration and offers a potential approach for lowering serum cholesterol and LDL levels.

  2. Elevated plasma YKL-40, lipids and lipoproteins, and ischemic vascular disease in the general population

    DEFF Research Database (Denmark)

    Kjaergaard, Alisa D; Johansen, Julia S; Bojesen, Stig E

    2015-01-01

    BACKGROUND AND PURPOSE: We tested the hypothesis that observationally and genetically elevated YKL-40 is associated with elevated lipids and lipoproteins and with increased risk of ischemic vascular disease. METHODS: We conducted cohort and Mendelian randomization studies in 96 110 individuals from...... the Danish general population, with measured plasma levels of YKL-40 (n=21 647), plasma lipids and lipoproteins (n=94 461), and CHI3L1 rs4950928 genotype (n=94 579). RESULTS: From 1977 to 2013, 3256 individuals developed ischemic stroke, 5629 ischemic cerebrovascular disease, 4183 myocardial infarction...

  3. Characterization of Lipoprotein Lipases interactions with Sortilin and SorLA

    DEFF Research Database (Denmark)

    Klinger, Stine Christensen

    and regulation of both ligands, as well as to increase the understanding of SorLA’s and sortilin’s functions. Sortilin and SorLA were both shown to bind apolipoprotein A-V at the cell surface and mediate endocytosis. Apolipoprotein A-V trafficking could subsequently be followed through early endosomes, the trans-Golgi......LA might be involved in regulation or transport of brain lipoprotein lipase. In summary, this work adds new details to the current knowledge about the functions of SorLA and sortilin. Moreover, it increases our understanding of lipoprotein lipase and apolipoprotein A-V processing and regulation....

  4. Staphylococcus aureus lipoproteins trigger human corneal epithelial innate response through toll-like receptor-2

    OpenAIRE

    Li, Qiong; Kumar, Ashok; Gui, Jian-Fang; Yu, Fu-Shin X.

    2007-01-01

    Bacterial lipoproteins (LP) are a family of cell wall components found in a wide variety of bacteria. In this study, we characterized the response of HUCL, a telomerase-immortalized human corneal epithelial cell (HCEC) line, to LP isolated from Staphylococcus (S) aureus. S. aureus LP (saLP) prepared by Triton X-114 extraction stimulated the activation of NF-κB, JNK, and P38 signaling pathways in HUCL cells. The extracts failed to stimulate NF-κB activation in HUCL cells after lipoprotein lipa...

  5. Purification and properties of a mitochondrial lipoprotein inhibitor of sterol synthesis

    International Nuclear Information System (INIS)

    Madhosingh, C.; Migicovsky, B.B.; Starratt, A.N.

    1976-01-01

    A lipoprotein inhibitor of hydroxymethylglutaryl CoA reductase (EC 1.1.1.34) and of cholesterol synthesis by rat liver homogenates, was isolated from the mitochondria of starved rats' livers. The isolated lipoprotein complex contained a low molecular weight protein and fatty acids. The fatty acids identified were arachidonic, linoleic, oleic, stearic and palmitic. The saturated fatty acids and oleic acid did not inhibit. Inhibition of the enzyme was to a large extent related to the degree of fatty acid unsaturation. (auth.)

  6. Social Inclusion Predicts Lower Blood Glucose and Low-Density Lipoproteins in Healthy Adults.

    Science.gov (United States)

    Floyd, Kory; Veksler, Alice E; McEwan, Bree; Hesse, Colin; Boren, Justin P; Dinsmore, Dana R; Pavlich, Corey A

    2017-08-01

    Loneliness has been shown to have direct effects on one's personal well-being. Specifically, a greater feeling of loneliness is associated with negative mental health outcomes, negative health behaviors, and an increased likelihood of premature mortality. Using the neuroendocrine hypothesis, we expected social inclusion to predict decreases in both blood glucose levels and low-density lipoproteins (LDLs) and increases in high-density lipoproteins (HDLs). Fifty-two healthy adults provided self-report data for social inclusion and blood samples for hematological tests. Results indicated that higher social inclusion predicted lower levels of blood glucose and LDL, but had no effect on HDL. Implications for theory and practice are discussed.

  7. Electrophoretic demonstration of glycoproteins, lipoproteins, and phosphoproteins in human and bovine enamel

    DEFF Research Database (Denmark)

    Kirkeby, S; Moe, D; Bøg-Hansen, T C

    1990-01-01

    Enamel proteins from fully mineralized human molars and from bovine tooth germs were separated by electrophoresis. The gels were stained for detection of glycoproteins, lipoproteins, and phosphoproteins. Glycoproteins were shown by periodic acid-Schiff staining and lectin blotting. In mature human...... enamel a number of high molecular weight proteins could be demonstrated after ethylenediaminetetra-acetic acid demineralization and subsequent Triton X-100 extraction. These proteins are suggested to be lipoproteins. Phosphoproteins could only be visualized in enamel matrix from the tooth germs....

  8. Oxidized lipoproteins are associated with markers of inflammation and immune activation in HIV-1 infection

    Science.gov (United States)

    Kelesidis, T; Jackson, N; McComsey, GA; Wang, X; Elashoff, D; Dube, MP; Brown, TT; Yang, OO; Stein, JH; Currier, JS

    2016-01-01

    Objective The pathogenesis of immune dysfunction in chronic HIV-1 infection is unclear, and a potential role for oxidized lipids has been suggested. We hypothesize that both oxidized low- and high-density lipoproteins (HDLox, LDLox) contribute to HIV-1 related immune dysfunction. Study In the AIDS Clinical Trials Group (ACTG) A5260, 234 HIV-infected antiretroviral therapy (ART)-naïve participants were randomized to receive tenofovir-emtricitabine plus protease inhibitors or raltegravir and had HIV-1 RNA lipoproteins may contribute to persistent immune activation on ART. PMID:27603288

  9. Clinical significance of changes of serum lipoprotein (a) levels in patients with cerebral vascular accidents

    International Nuclear Information System (INIS)

    Li Qian; Chen Xinghua

    2004-01-01

    Objective: To investigate the relationship between changes of serum lipoprotein (a) levels and development of stroke. Methods: Lipoprotein (a) levels were determined with ELISA in 100 patients with stroke and 60 controls. Results: The serum LP (a) levels in patients with stroke complicated with diabetes were also significantly higher than those in patients with stroke but without diabetes (P<0.01). Conclusion: The levels of serum LP(a) was a relatively independent risk factor, and it could be of some prognostic value. (authors)

  10. Lipoprotein metabolism in familial hypercholesterolemia: Serial assessment using a one-step ultracentrifugation method

    Directory of Open Access Journals (Sweden)

    Hayato Tada

    2015-04-01

    Full Text Available Objectives: It is well known that familial hypercholesterolemia (FH is a common inherited disorder that can markedly elevate the level of plasma LDL cholesterol. However, little data exists regarding the clinical impact of the plasma triglyceride (TG-rich lipoprotein fraction, including VLDL and IDL, in FH. Thus, we assessed the hypothesis that the mutations in the LDL receptor modulate lipoprotein metabolism other than the LDL fraction. Design and methods: We investigated plasma lipoprotein with a one-step ultracentrifugation method for 146 controls (mean age=61.4±17.1 yr, mean LDL cholesterol=92.7±61.2 mg/dl, 213 heterozygous mutation-determined FH subjects (mean age=46.0±18.0 yr, mean LDL cholesterol=225.1±61.2 mg/dl, and 16 homozygous/compound heterozygous mutation-determined FH subjects (mean age=26.9±17.1 yr, mean LDL cholesterol=428.6±86.1 mg/dl. In addition, we evaluated cholesterol/TG ratio in each lipoprotein fraction separated by ultracentrifugation. Results: In addition to total cholesterol and LDL cholesterol levels, VLDL cholesterol (19.5±10.4, 25.2±19.3, 29.5±21.4 mg/dl, respectively and IDL cholesterol (8.3±3.7, 16.8±11.5, 40.0±37.3 mg/dl, respectively exhibited a tri-model distribution according to their status in LDL receptor mutation(s. Moreover, the ratios of cholesterol/TG of each lipoprotein fraction increased significantly in heterozygous FH and homozygous/compound heterozygous FH groups, compared with that of controls, suggesting that the abnormality in LDL receptor modulates the quality as well as the quantity of each lipoprotein fraction. Conclusions: Our results indicate that cholesterol in TG-rich lipoproteins, including VLDL and IDL, are significantly higher in FH subjects, revealing a tri-modal distribution according to the number of LDL receptor mutations. Keywords: LDL cholesterol, Familial hypercholesterolemia, Ultracentrifugation, Lipoprotein

  11. Darapladib, a lipoprotein-associated phospholipase A2 inhibitor, in diabetic macular edema

    DEFF Research Database (Denmark)

    Staurenghi, Giovanni; Ye, Li; Magee, Mindy H

    2015-01-01

    PURPOSE: To investigate the potential of lipoprotein-associated phospholipase A2 inhibition as a novel mechanism to reduce edema and improve vision in center-involved diabetic macular edema (DME). DESIGN: Prospective, multicenter, randomized, double-masked, placebo-controlled phase IIa study...... (AEs) and nonocular AEs were similar between treatment groups. CONCLUSIONS: Once-daily oral darapladib administered for 3 months demonstrated modest improvements in vision and macular edema that warrant additional investigation of this novel lipoprotein-associated phospholipase A2 inhibitory mechanism...

  12. Metabolism of triglyceride-rich lipoproteins and transfer of lipids to high-density lipoproteins (HDL) in vegan and omnivore subjects.

    Science.gov (United States)

    Vinagre, J C; Vinagre, C G; Pozzi, F S; Slywitch, E; Maranhão, R C

    2013-01-01

    Vegan diet excludes all foodstuffs of animal origin and leads to cholesterol lowering and possibly reduction of cardiovascular disease risk. The aim was to investigate whether vegan diet improves the metabolic pathway of triglyceride-rich lipoproteins, consisting in lipoprotein lipolysis and removal from circulation of the resulting remnants and to verify whether the diet alters HDL metabolism by changing lipid transfers to this lipoprotein. 21 vegan and 29 omnivores eutrophic and normolipidemic subjects were intravenously injected triglyceride-rich emulsions labeled with (14)C-cholesterol oleate and (3)H-triolein: fractional clearance rates (FCR, in min(-1)) were calculated from samples collected during 60 min for radioactive counting. Lipid transfer to HDL was assayed by incubating plasma samples with a donor nanoemulsion labeled with radioactive lipids; % lipids transferred to HDL were quantified in supernatant after chemical precipitation of non-HDL fractions and nanoemulsion. Serum LDL cholesterol was lower in vegans than in omnivores (2.1 ± 0.8, 2.7 ± 0.7 mmol/L, respectively, p vegans than in omnivores (0.016 ± 0.012, 0.003 ± 0.003, p vegans than in omnivores (2.7 ± 0.6, 3.5 ± 1.5%, p vegans, but the lipolysis process, estimated by triglyceride FCR was equal. Increased removal of atherogenic remnants and diminution of cholesteryl ester transfer may favor atherosclerosis prevention by vegan diet. Copyright © 2011 Elsevier B.V. All rights reserved.

  13. Lipoprotein lipase gene polymorphisms: associations with myocardial infarction and lipoprotein levels, the ECTIM study. Etude Cas Témoin sur l'Infarctus du Myocarde.

    Science.gov (United States)

    Jemaa, R; Fumeron, F; Poirier, O; Lecerf, L; Evans, A; Arveiler, D; Luc, G; Cambou, J P; Bard, J M; Fruchart, J C

    1995-10-01

    Several lipoprotein lipase (LPL) gene polymorphisms have been found associated with fasting lipid levels, but their impact on coronary heart disease (CHD) is less clearly established. We investigated associations of LPL polymorphisms (HindIII, PvuII, Ser447-->Ter) and the newly described mutation Asn291-->Ser with the risk of myocardial infarction (MI), severity of atherosclerosis, and fasting plasma lipoprotein concentrations in the ECTIM study (614 patients and 733 controls). The Ter447 allele had a lowering effect on triglycerides (P Ser polymorphisms did not exhibit any significant association with the biochemical traits examined. The HindIII genotype distributions differed between cases and controls, the odds ratios for MI associated with H+H+ and H+H- genotypes being 2.05 (P Ter and MI suggested that this mutation was unlikely to be the cause of the association found with HindIII. In some cases, the severity of atherosclerosis assessed by coronarography increased with the presence of P+ allele (coronary scores: 1.41, 1.57, and 1.64 in P-P-, P-P+, and P+P+ individuals respectively, P Ser mutation (1.58 vs. 1.90, P = 0.06). Our results suggest that the LPL gene is involved in the determination of lipoprotein profiles, the predisposition to CHD, and the severity of atherosclerosis.

  14. Onset of lipoprotein-supported steroidogenesis in differentiating granulosa cells of rats: cellular events involved in mediating FSH-enhanced uptake of low-density lipoproteins

    International Nuclear Information System (INIS)

    Foster, J.D.

    1987-01-01

    Luteal cells use lipoproteins as the main source of cholesterol in steroidogenesis. However, little is known about the mechanisms underlying hormonal control of lipoprotein uptake. Thus, the authors tested the hypothesis that FSH and androgens regulate low density lipoprotein (LDL)-supported steroidogenesis in maturing granulosa cells by affecting receptor-mediated endocytosis of LDL at a cellular level. For this, immature ovarian granulosa cells were cultured with or without hormones, compactin (de novo synthesis inhibitor), or unlabeled or labeled ( 125 I or gold particles) LDL. Nonhormone-treated cultures produced little progestin; FSH and FSH/androstenedione stimulated steroid secretion. Progestin production by hormone-, but not nonhormone-, treated cultures was decreased by compactin, suggesting that de novo synthesis provided sterol for steroidogenesis. EM quantitation of cells exposed to gold-LDL at 37 0 C revealed that, compared to nonhormone-treated cells, FSH-treated cells (1) bound and internalized more gold-LDL, (2) had a smaller percentage of gold-LDL at their surfaces, (3) displayed a faster apparent rate of LDL internalization and delivery to lysosomes, and (4) contained more gold-labeled lysosomes. Data from biochemical studies in which 125 I-LDL was used supported the morphological findings. In conclusion, this study demonstrates that FSH has important effects at the cellular level on LDL uptake, which seem to underlie the striking increase in progestin production accompanying granulosa cell differentiation

  15. microRNA-4516 Contributes to Different Functions of Epithelial Permeability Barrier by Targeting Poliovirus Receptor Related Protein 1 in Enterovirus 71 and Coxsackievirus A16 Infections

    Directory of Open Access Journals (Sweden)

    Yajie Hu

    2018-04-01

    Full Text Available Enterovirus 71 (EV-A71 and coxsackievirus A16 (CV-A16 remain the predominant etiological agents of hand, foot, and mouth disease (HFMD. The clinical manifestations caused by the two viruses are obviously different. CV-A16 usually triggers a repeated infection, and airway epithelial integrity is often the potential causative factor of respiratory repeated infections. Our previous studies have demonstrated that there were some differentially expressed miRNAs involved in the regulation of adhesion function of epithelial barrier in EV-A71 and CV-A16 infections. In this study, we compared the differences between EV-A71 and CV-A16 infections on the airway epithelial barrier function in human bronchial epithelial (16HBE cells and further screened the key miRNA which leaded to the formation of these differences. Our results showed that more rapid proliferation, more serious destruction of 16HBE cells permeability, more apoptosis and disruption of intercellular adhesion-associated molecules were found in CV-A16 infection as compared to EV-A71 infection. Furthermore, we also identified that microRNA-4516 (miR-4516, which presented down-regulation in EV-A71 infection and up-regulation in CV-A16 infection was an important regulator of intercellular junctions by targeting Poliovirus receptor related protein 1(PVRL1. The expressions of PVRL1, claudin4, ZO-1 and E-cadherin in CV-A16-infected cells were significantly less than those in EV-A71-infected cells, while the expressions of these proteins were subverted when pre-treated with miR-4516-overexpression plasmid in EV-A71 infected and miR-4516-knockdown plasmid in CV-A16 infected 16HBE cells. Thus, these data suggested that the opposite expression of miR-4516 in EV-A71 and CV-A16 infections might be the initial steps leading to different epithelial impairments of 16HBE cells by destroying intercellular adhesion, which finally resulted in different outcomes of EV-A71 and CV-A16 infections.

  16. Pregnancy-associated osteoporosis with a heterozygous deactivating LDL receptor-related protein 5 (LRP5) mutation and a homozygous methylenetetrahydrofolate reductase (MTHFR) polymorphism.

    Science.gov (United States)

    Cook, Fiona J; Mumm, Steven; Whyte, Michael P; Wenkert, Deborah

    2014-04-01

    Pregnancy-associated osteoporosis (PAO) is a rare, idiopathic disorder that usually presents with vertebral compression fractures (VCFs) within 6 months of a first pregnancy and delivery. Spontaneous improvement is typical. There is no known genetic basis for PAO. A 26-year-old primagravida with a neonatal history of unilateral blindness attributable to hyperplastic primary vitreous sustained postpartum VCFs consistent with PAO. Her low bone mineral density (BMD) seemed to respond to vitamin D and calcium therapy, with no fractures after her next successful pregnancy. Investigation of subsequent fetal losses revealed homozygosity for the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism associated both with fetal loss and with osteoporosis (OP). Because her neonatal unilateral blindness and OP were suggestive of loss-of-function mutation(s) in the gene that encodes LDL receptor-related protein 5 (LRP5), LRP5 exon and splice site sequencing was also performed. This revealed a unique heterozygous 12-bp deletion in exon 21 (c.4454_4465del, p.1485_1488del SSSS) in the patient, her mother and sons, but not her father or brother. Her mother had a normal BMD, no history of fractures, PAO, ophthalmopathy, or fetal loss. Her two sons had no ophthalmopathy and no skeletal issues. Her osteoporotic father (with a family history of blindness) and brother had low BMDs first documented at ages ∼40 and 32 years, respectively. Serum biochemical and bone turnover studies were unremarkable in all subjects. We postulate that our patient's heterozygous LRP5 mutation together with her homozygous MTHFR polymorphism likely predisposed her to low peak BMD. However, OP did not cosegregate in her family with the LRP5 mutation, the homozygous MTHFR polymorphism, or even the combination of the two, implicating additional genetic or nongenetic factors in her PAO. Nevertheless, exploration for potential genetic contributions to PAO may explain part of the pathogenesis of this

  17. Inhibitory effects of azole-type fungicides on interleukin-17 gene expression via retinoic acid receptor-related orphan receptors α and γ

    Energy Technology Data Exchange (ETDEWEB)

    Kojima, Hiroyuki, E-mail: kojima@iph.pref.hokkaido.jp [Hokkaido Institute of Public Health, Kita-19, Nishi-12, Kita-ku, Sapporo 060-0819 (Japan); Muromoto, Ryuta; Takahashi, Miki [Graduate School of Pharmaceutical Sciences, Hokkaido University, Kita-12, Nishi-6, Kita-ku, Sapporo 060-0812 (Japan); Takeuchi, Shinji [Hokkaido Institute of Public Health, Kita-19, Nishi-12, Kita-ku, Sapporo 060-0819 (Japan); Takeda, Yukimasa; Jetten, Anton M. [National Institute of Environmental Health Sciences, National Institutes of Health, 111 T. W. Alexander Drive, Research Triangle Park, NC 27709 (United States); Matsuda, Tadashi [Graduate School of Pharmaceutical Sciences, Hokkaido University, Kita-12, Nishi-6, Kita-ku, Sapporo 060-0812 (Japan)

    2012-03-15

    The retinoic acid receptor-related orphan receptors α and γ (RORα and RORγ), are key regulators of helper T (Th)17 cell differentiation, which is involved in the innate immune system and autoimmune disorders. However, it remains unclear whether environmental chemicals, including pesticides, have agonistic and/or antagonistic activity against RORα/γ. In this study, we investigated the RORα/γ activity of several azole-type fungicides, and the effects of these fungicides on the gene expression of interleukin (IL)-17, which mediates the function of Th17 cells. In the ROR-reporter gene assays, five azole-type fungicides (imibenconazole, triflumizole, hexaconazole, tetraconazole and imazalil) suppressed RORα- and/or RORγ-mediated transcriptional activity as did benzenesulphonamide T0901317, a ROR inverse agonist and a liver X receptor (LXR) agonist. In particular, imibenconazole, triflumizole and hexaconazole showed RORγ inverse agonistic activity at concentrations of 10{sup −6} M. However, unlike T0901317, these fungicides failed to show any LXRα/β agonistic activity. Next, five azole-type fungicides, showing ROR inverse agonist activity, were tested on IL-17 mRNA expression in mouse T lymphoma EL4 cells treated with phorbol myristate acetate and ionomycin. The quantitative RT-PCR analysis revealed that these fungicides suppressed the expression of IL-17 mRNA without effecting RORα and RORγ mRNA levels. In addition, the inhibitory effect of imibenconazole as well as that of T0901317 was absorbed in RORα/γ-knocked down EL4 cells. Taken together, these results suggest that some azole-type fungicides inhibit IL-17 production via RORα/γ. This also provides the first evidence that environmental chemicals can act as modulators of IL-17 expression in immune cells. -- Highlights: ► Nuclear receptors, RORα and RORγ, are key regulators of Th17 cell differentiation. ► Five azole-type fungicides act as RORα/γ inverse agonists. ► These fungicides

  18. Inhibitory effects of azole-type fungicides on interleukin-17 gene expression via retinoic acid receptor-related orphan receptors α and γ

    International Nuclear Information System (INIS)

    Kojima, Hiroyuki; Muromoto, Ryuta; Takahashi, Miki; Takeuchi, Shinji; Takeda, Yukimasa; Jetten, Anton M.; Matsuda, Tadashi

    2012-01-01

    The retinoic acid receptor-related orphan receptors α and γ (RORα and RORγ), are key regulators of helper T (Th)17 cell differentiation, which is involved in the innate immune system and autoimmune disorders. However, it remains unclear whether environmental chemicals, including pesticides, have agonistic and/or antagonistic activity against RORα/γ. In this study, we investigated the RORα/γ activity of several azole-type fungicides, and the effects of these fungicides on the gene expression of interleukin (IL)-17, which mediates the function of Th17 cells. In the ROR-reporter gene assays, five azole-type fungicides (imibenconazole, triflumizole, hexaconazole, tetraconazole and imazalil) suppressed RORα- and/or RORγ-mediated transcriptional activity as did benzenesulphonamide T0901317, a ROR inverse agonist and a liver X receptor (LXR) agonist. In particular, imibenconazole, triflumizole and hexaconazole showed RORγ inverse agonistic activity at concentrations of 10 −6 M. However, unlike T0901317, these fungicides failed to show any LXRα/β agonistic activity. Next, five azole-type fungicides, showing ROR inverse agonist activity, were tested on IL-17 mRNA expression in mouse T lymphoma EL4 cells treated with phorbol myristate acetate and ionomycin. The quantitative RT-PCR analysis revealed that these fungicides suppressed the expression of IL-17 mRNA without effecting RORα and RORγ mRNA levels. In addition, the inhibitory effect of imibenconazole as well as that of T0901317 was absorbed in RORα/γ-knocked down EL4 cells. Taken together, these results suggest that some azole-type fungicides inhibit IL-17 production via RORα/γ. This also provides the first evidence that environmental chemicals can act as modulators of IL-17 expression in immune cells. -- Highlights: ► Nuclear receptors, RORα and RORγ, are key regulators of Th17 cell differentiation. ► Five azole-type fungicides act as RORα/γ inverse agonists. ► These fungicides suppress

  19. Ten years of lipoprotein apheresis for familial hypercholesterolemia in Malaysia: A creative approach by a cardiologist in a developing country

    NARCIS (Netherlands)

    Khoo, Kah Lin; Page, Michael M.; Liew, Yin Mei; Defesche, Joep C.; Watts, Gerald F.

    2016-01-01

    Familial hypercholesterolemia (FH) leads to premature coronary artery disease and aortic stenosis, with undertreated severe forms causing death at a young age. Lipoprotein apheresis (LA) is often required for lowering low-density lipoprotein cholesterol levels in severe FH. The objective of this

  20. Moderate alcohol consumption and changes in postprandial lipoproteins of premenopausal and postmenopausal women : a diet-controlled, randomized intervention study

    NARCIS (Netherlands)

    Gaag, van der M.S.; Sierksma, A.; Schaafsma, G.; Bakker, M.; Hendriks, J.F.J.

    2000-01-01

    Moderate alcohol consumption is associated with a reduced risk of coronary heart disease. Earlier studies in men have shown that moderate alcohol consumption affects lipoprotein metabolism and hemostasis. In this diet-controlled, randomized, crossover trial, we investigated the effect on lipoprotein

  1. DMPD: The oxidation of lipoproteins by monocytes-macrophages. Biochemical andbiological mechanisms. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 10473535 The oxidation of lipoproteins by monocytes-macrophages. Biochemical andbio.... (.png) (.svg) (.html) (.csml) Show The oxidation of lipoproteins by monocytes-macrophages. Biochemical and...onocytes-macrophages. Biochemical andbiological mechanisms. Authors Chisolm GM 3rd, Hazen SL, Fox PL, Cathca

  2. Increased lipogenesis and resistance of lipoproteins to oxidative modification in two patients with glycogen storage disease type 1a

    NARCIS (Netherlands)

    Bandsma, RHJ; Rake, JP; Visser, G; Neese, RA; Hellerstein, MK; van Duyvenvoorde, W; Princen, HMG; Stellaard, F; Smit, GPA; Kuipers, F

    We describe 2 patients with glycogen storage disease type la and severe hyperlipidemia without premature atherosclerosis. Susceptibility of low-density lipoproteins to oxidation was decreased, possibly related to the similar to40-fold increase in palmitate synthesis altering lipoprotein saturated

  3. An extrahepatic receptor-associated protein-sensitive mechanism is involved in the metabolism of triglyceride-rich lipoproteins

    NARCIS (Netherlands)

    Vlijmen, B.J.M. van; Rohlmann, A.; Page, S.T.; Bensadoun, A.; Bos, I.S.T.; Berkel, T.J.C. van; Havekes, L.M.; Herz, J.

    1999-01-01

    We have used adenovirus-mediated gene transfer in mice to investigate low density lipoprotein receptor (LDLR) and LDLR-related protein (LRP)- independent mechanisms that control the metabolism of chylomicron and very low density lipoprotein (VLDL) remnants in vivo. Overexpression of receptor-

  4. Dynamics of the content of lipoproteins in blood serum of carp under the influence of ions of heavy metals

    International Nuclear Information System (INIS)

    Kurant, V.Z.; Sinyuk, Yu.V.; Arsan, V.O.; Grubyinko, V.V.

    2005-01-01

    A change of the content of lipoproteins in the blood serum of carp under the influence of ions of manganese, zinc, copper, and lead is studied. The important role of lipoproteins in the blood serum of fish in the processes of detoxication of ions of heavy metals that come to their organism from the water environment is shown

  5. Plasma Lp-PLA2 mass and apoB-lipoproteins that carry Lp-PLA2 decrease after sodium

    NARCIS (Netherlands)

    Constantinides, Alexander; Kerstens, Michiel N.; Dikkeschei, Bert D.; van Pelt, L. Joost; Tellis, Constantinos C.; Tselepis, Alexandros D.; Dullaart, Robin P. F.

    2012-01-01

    Eur J Clin Invest 2012; 42 (11): 12351243 Abstract Background Lipoprotein-associated phospholipase A2 (Lp-PLA2) is a novel cardiovascular risk marker, which is predominantly complexed to apolipoprotein (apo) B-containing lipoproteins in human plasma. As increasing dietary sodium intake may decrease

  6. A Common LPA Null Allele Associates With Lower Lipoprotein(a) Levels and Coronary Artery Disease Risk

    NARCIS (Netherlands)

    Kyriakou, Theodosios; Seedorf, Udo; Goel, Anuj; Hopewell, Jemma C.; Clarke, Robert; Watkins, Hugh; Farrall, Martin; van der Hout, A.H.

    Objective-Increased levels of lipoprotein(a) are a highly heritable risk factor for coronary artery disease (CAD). The genetic determinants of lipoprotein(a) levels are mainly because of genetic variation in the apolipoprotein(a) gene (LPA). We have tested the association of a relatively common null

  7. Effect of theobromine consumption on serum lipoprotein profiles in apparently healthy humans with low HDL-cholesterol concentrations

    NARCIS (Netherlands)

    Jacobs, Doris M.; Smolders, Lotte; Lin, Yuguang; Roo, de Niels; Trautwein, Elke A.; Duynhoven, van John; Mensink, Ronald P.; Plat, Jogchum; Mihaleva, Velitchka V.

    2017-01-01

    Scope: Theobromine is a major active compound in cocoa with allegedly beneficial effect on high-density-lipoprotein-cholesterol (HDL-CH). We have investigated the effect of theobromine (TB) consumption on the concentrations of triglyceride (TG) and cholesterol (CH) in various lipoprotein (LP)

  8. A lipoprotein lipase mutation (Asn291Ser) is associated with reduced HDL cholesterol levels in premature atherosclerosis

    NARCIS (Netherlands)

    Reymer, P.W.A.; Gagné, S E; Groenemeyer, B E; Zhang, H; Forsyth, I; Jansen, H; Seidell, J C; Kromhout, D.; Lie, K E; Kastelein, J.J.

    1995-01-01

    A reduction of high density lipoprotein cholesterol (HDC) is recognized as an important risk factor for coronary artery disease (CAD). We now show in approximately 1 in 20 males with proven atherosclerosis that an Asn291Ser mutation in the human lipoprotein lipase (LPL) gene is associated with

  9. Plasma levels of HDL subpopulations and remnant lipoproteins predict the extent of angiographically defined disease in post-menopausal women

    Science.gov (United States)

    The association of coronary heart disease (CHD) with subpopulations of triglyceride (TG)-rich lipoproteins and high-density lipoproteins (HDL) is established in men, but has not been well characterized in women. Plasma HDL subpopulation concentrations, quantified by 2-dimensional gel electrophoresis...

  10. Effects of aerobic exercise, diet, or both on lipids and lipoproteins in adults: a meta-analysis

    Science.gov (United States)

    BACKGROUND: Studies addressing the effects of aerobic exercise (E), diet (D), or both (ED) on lipids and lipoproteins have led to conflicting results. OBJECTIVE: Determine the effects of E, D, and ED on lipids and lipoproteins. METHODS: Using the aggregate data meta-analytic approach, studies were ...

  11. Plasma Lipoprotein-associated Phospholipase A(2) Is Inversely Correlated with Proprotein Convertase Subtilisin-kexin Type 9

    NARCIS (Netherlands)

    Constantinides, Alexander; Kappelle, Paul J.W.H.; Lambert, Gilles; Dullaart, Robin P. F.

    Background and Aims. Lipoprotein-associated phospholipase A(2) (Lp-PLA(2)) is a proatherogenic phospholipase A(2), which is predominantly complexed to low-density lipoprotein (LDL) particles. Proprotein convertase subtilisin-kexin type 9 (PCSK9) provides a key step in LDL metabolism by stimulating

  12. Characterization of blood lipoproteins and validation of cholesterol and triacylglycerol assays for free-ranging polar bears (Ursus maritimus).

    Science.gov (United States)

    Whiteman, John P; Frank, Nicholas; Greller, Katie A; Harlow, Henry J; Ben-David, Merav

    2013-05-01

    Blood triacylglycerol (TG) and lipoproteins are important variables for evaluating nutritional status of wildlife, but measurements are often expensive and difficult. Performance of a small, portable blood analyzer intended for human medical diagnostics was evaluated in measuring these variables in plasma and serum from free-ranging polar bears (Ursus maritimus), which are experiencing nutritional stress related to sea ice loss. The analyzer accurately tracked changes in concentration of total cholesterol (Ctotal), cholesterol associated with high-density lipoprotein (CHDL), and TG during a validation protocol of diluting samples and spiking them with exogenous cholesterol and glycerol. Values of Ctotal and TG agreed well with values obtained by other methods (ultracentrifugation followed by colorimetric assays); agreement was variable for values of cholesterol associated with specific lipoproteins. Similar to a study of captive polar bears, ultracentrifugation methods revealed greater TG in very low-density lipoproteins than in low-density lipoprotein, which is unusual and merits additional study.

  13. Hepatitis C Virus, Cholesterol and Lipoproteins — Impact for the Viral Life Cycle and Pathogenesis of Liver Disease

    Science.gov (United States)

    Felmlee, Daniel J.; Hafirassou, Mohamed Lamine; Lefevre, Mathieu; Baumert, Thomas F.; Schuster, Catherine

    2013-01-01

    Hepatitis C virus (HCV) is a leading cause of chronic liver disease, including chronic hepatitis, fibrosis, cirrhosis, and hepatocellular carcinoma. Hepatitis C infection associates with lipid and lipoprotein metabolism disorders such as hepatic steatosis, hypobetalipoproteinemia, and hypocholesterolemia. Furthermore, virus production is dependent on hepatic very-low-density lipoprotein (VLDL) assembly, and circulating virions are physically associated with lipoproteins in complexes termed lipoviral particles. Evidence has indicated several functional roles for the formation of these complexes, including co-opting of lipoprotein receptors for attachment and entry, concealing epitopes to facilitate immune escape, and hijacking host factors for HCV maturation and secretion. Here, we review the evidence surrounding pathogenesis of the hepatitis C infection regarding lipoprotein engagement, cholesterol and triglyceride regulation, and the molecular mechanisms underlying these effects. PMID:23698400

  14. Lipoprotein Lipase and PPAR Alpha Gene Polymorphisms, Increased Very-Low-Density Lipoprotein Levels, and Decreased High-Density Lipoprotein Levels as Risk Markers for the Development of Visceral Leishmaniasis by Leishmania infantum

    Directory of Open Access Journals (Sweden)

    Márcia Dias Teixeira Carvalho

    2014-01-01

    Full Text Available In visceral leishmaniasis (VL endemic areas, a minority of infected individuals progress to disease since most of them develop protective immunity. Therefore, we investigated the risk markers of VL within nonimmune sector. Analyzing infected symptomatic and, asymptomatic, and noninfected individuals, VL patients presented with reduced high-density lipoprotein cholesterol (HDL-C, elevated triacylglycerol (TAG, and elevated very-low-density lipoprotein cholesterol (VLDL-C levels. A polymorphism analysis of the lipoprotein lipase (LPL gene using HindIII restriction digestion (N = 156 samples (H+ = the presence and H− = the absence of mutation revealed an increased adjusted odds ratio (OR of VL versus noninfected individuals when the H+/H+ was compared with the H−/H− genotype (OR = 21.3; 95% CI = 2.32–3335.3; P = 0.003. The H+/H+ genotype and the H+ allele were associated with elevated VLDL-C and TAG levels (P < 0.05 and reduced HDL-C levels (P < 0.05. An analysis of the L162V polymorphism in the peroxisome proliferator-activated receptor alpha (PPARα gene (n = 248 revealed an increased adjusted OR when the Leu/Val was compared with the Leu/Leu genotype (OR = 8.77; 95% CI = 1.41–78.70; P = 0.014. High TAG (P = 0.021 and VLDL-C (P = 0.023 levels were associated with susceptibility to VL, whereas low HDL (P = 0.006 levels with resistance to infection. The mutated LPL and the PPARα Leu/Val genotypes may be considered risk markers for the development of VL.

  15. Genetic analysis of long-lived families reveals novel variants influencing high density-lipoprotein cholesterol

    DEFF Research Database (Denmark)

    Feitosa, Mary F; Wojczynski, Mary K; Straka, Robert

    2014-01-01

    The plasma levels of high-density lipoprotein cholesterol (HDL) have an inverse relationship to the risks of atherosclerosis and cardiovascular disease (CVD), and have also been associated with longevity. We sought to identify novel loci for HDL that could potentially provide new insights...

  16. Low density lipoprotein induces upregulation of vasoconstrictive endothelin type B receptor expression

    DEFF Research Database (Denmark)

    Xu, Cang-Bao; Zheng, Jian-Pu; Zhang, Wei

    2014-01-01

    Vasoconstrictive endothelin type B (ET(B)) receptors promote vasospasm and ischemic cerebro- and cardiovascular diseases. The present study was designed to examine if low density lipoprotein (LDL) induces upregulation of vasoconstrictive ET(B) receptor expression and if extracellular signal...

  17. Moderate alcohol consumption and lipoprotein-associated phospholipase A2 activity

    NARCIS (Netherlands)

    Beulens, J.W.J.; Berg, R. van den; Kok, F.J.; Helander, A.; Vermunt, S.H.F.; Hendriks, H.F.J.

    2008-01-01

    Background and aims: To investigate the effect of moderate alcohol consumption on lipoprotein-associated phospholipase A2 activity, markers of inflammation and oxidative stress and whether these effects are modified by BMI. Methods and results: Eleven lean (BMI: 18.5-25 kg/m2) and 9 overweight (BMI

  18. Pyrene-Labeled Amphiphiles: Dynamic And Structural Probes Of Membranes And Lipoproteins

    Science.gov (United States)

    Pownall, Henry J.; Homan, Reynold; Massey, John B.

    1987-01-01

    Lipids and proteins are important functional and structural components of living organisms. Although proteins are frequently found as soluble components of plasma or the cell cytoplasm, many lipids are much less soluble and separate into complex assemblies that usually contain proteins. Cell membranes and plasma lipoproteins' are two important macro-molecular assemblies that contain both lipids and proteins. Cell membranes are composed of a variety of lipids and proteins that form an insoluble bilayer array that has relatively little curvature over distances of several nm. Plasma lipoproteins are different in that they are much smaller, water-soluble, and have highly curved surfaces. A model of a high density lipoprotein (HDL) is shown in Figure 1. This model (d - 10 nm) contains a surface of polar lipids and proteins that surrounds a small core of insoluble lipids, mostly triglycerides and cholesteryl esters. The low density (LDL) (d - 25 nm) and very low density (VLDL) (d 90 nm) lipoproteins have similar architectures, except the former has a cholesteryl ester core and the latter a core that is almost exclusively triglyceride (Figure 1). The surface proteins of HDL are amphiphilic and water soluble; the single protein of LDL is insoluble, whereas VLDL contains both soluble and insoluble proteins. The primary structures of all of these proteins are known.

  19. Effect of methylglyoxal on the physico-chemical and biological properties of low-density lipoprotein

    NARCIS (Netherlands)

    Schalkwijk, C.G.; Vermeer, M.A.; Stehouwer, C.D.A.; Koppele, J. te; Princen, H.M.G.; Hinsbergh, V.W.M. van

    1998-01-01

    In patients with diabetes, non-enzymatic glycation of low-density lipoprotein (LDL) has been suggested to be involved in the development of atherosclerosis. α-Dicarbonyl compounds were identified as intermediates in the non-enzymatic glycation and increased levels were reported in patients with

  20. Genetics, Lifestyle, and Low-Density Lipoprotein Cholesterol in Young and Apparently Healthy Women

    NARCIS (Netherlands)

    Balder, Jan-Willem; Rimbert, Antoine; Zhang, Xiang; Viel, Martijn; Kanninga, Roan; van Dijk, Freerk; Lansberg, Peter; Sinke, Richard; Kuivenhoven, Jan Albert

    2018-01-01

    BACKGROUND: Atherosclerosis starts in childhood but low-density lipoprotein cholesterol (LDL-C), a causal risk factor, is mostly studied and dealt with when clinical events have occurred. Women are usually affected later in life than men and are underdiagnosed, undertreated, and understudied in