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Axmann M, Plochberger B, Mikula M, Weber F, Strobl WM, Stangl H. Plasma Membrane Lipids: An Important Binding Site for All Lipoprotein Classes. MEMBRANES 2021; 11:membranes11110882. [PMID: 34832111 PMCID: PMC8622984 DOI: 10.3390/membranes11110882] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 11/12/2021] [Accepted: 11/12/2021] [Indexed: 12/23/2022]
Abstract
Cholesterol is one of the main constituents of plasma membranes; thus, its supply is of utmost importance. This review covers the known mechanisms of cholesterol transfer from circulating lipoprotein particles to the plasma membrane, and vice versa. To achieve homeostasis, the human body utilizes cellular de novo synthesis and extracellular transport particles for supply of cholesterol and other lipids via the blood stream. These lipoprotein particles can be classified according to their density: chylomicrons, very low, low, and high-density lipoprotein (VLDL, LDL, and HDL, respectively). They deliver and receive their lipid loads, most importantly cholesterol, to and from cells by several redundant routes. Defects in one of these pathways (e.g., due to mutations in receptors) usually are not immediately fatal. Several redundant pathways, at least temporarily, compensate for the loss of one or more of them, but the defects trigger systemic diseases, such as atherosclerosis later on. Recently, intracellular membrane–membrane contact sites were shown to be involved in intracellular cholesterol transfer and the plasma membrane itself has been proposed to act as a binding site for lipoprotein-mediated cargo unloading.
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Affiliation(s)
- Markus Axmann
- School of Medical Engineering and Applied Social Sciences, University of Applied Sciences Upper Austria, Garnisonstrasse 21, 4020 Linz, Austria; (M.A.); (B.P.); (F.W.)
| | - Birgit Plochberger
- School of Medical Engineering and Applied Social Sciences, University of Applied Sciences Upper Austria, Garnisonstrasse 21, 4020 Linz, Austria; (M.A.); (B.P.); (F.W.)
| | - Mario Mikula
- Center for Pathobiochemistry and Genetics, Institute for Medical Genetics, Medical University of Vienna, Währingerstrasse 10, 1090 Vienna, Austria;
| | - Florian Weber
- School of Medical Engineering and Applied Social Sciences, University of Applied Sciences Upper Austria, Garnisonstrasse 21, 4020 Linz, Austria; (M.A.); (B.P.); (F.W.)
| | - Witta Monika Strobl
- Center for Pathobiochemistry and Genetics, Institute for Medical Chemistry, Medical University of Vienna, Währingerstrasse 10, 1090 Vienna, Austria;
| | - Herbert Stangl
- Center for Pathobiochemistry and Genetics, Institute for Medical Chemistry, Medical University of Vienna, Währingerstrasse 10, 1090 Vienna, Austria;
- Correspondence:
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Abstract
Cholesterol homeostasis is of central importance for life. Therefore, cells have developed a divergent set of pathways to meet their cholesterol needs. In this review, we focus on the direct transfer of cholesterol from lipoprotein particles to the cell membrane. More molecular details on the transfer of lipoprotein-derived lipids were gained by recent studies using phospholipid bilayers. While amphiphilic lipids are transferred right after contact of the lipoprotein particle with the membrane, the transfer of core lipids is restricted. Amphiphilic lipid transfer gains special importance in genetic diseases impairing lipoprotein metabolism like familial hypercholesterolemia. Taken together, these data indicate that there is a constant exchange of amphiphilic lipids between lipoprotein particles and the cell membrane.
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Haselgrübler R, Lanzerstorfer P, Röhrl C, Stübl F, Schurr J, Schwarzinger B, Schwarzinger C, Brameshuber M, Wieser S, Winkler SM, Weghuber J. Hypolipidemic effects of herbal extracts by reduction of adipocyte differentiation, intracellular neutral lipid content, lipolysis, fatty acid exchange and lipid droplet motility. Sci Rep 2019; 9:10492. [PMID: 31324860 PMCID: PMC6642187 DOI: 10.1038/s41598-019-47060-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Accepted: 07/05/2019] [Indexed: 12/12/2022] Open
Abstract
An increase in adipose tissue is caused by the increased size and number of adipocytes. Lipids accumulate in intracellular stores, known as lipid droplets (LDs). Recent studies suggest that parameters such as LD size, shape and dynamics are closely related to the development of obesity. Berberine (BBR), a natural plant alkaloid, has been demonstrated to possess anti-obesity effects. However, it remains unknown which cellular processes are affected by this compound or how effective herbal extracts containing BBR and other alkaloids actually are. For this study, we used extracts of Coptis chinensis, Mahonia aquifolium, Berberis vulgaris and Chelidonium majus containing BBR and other alkaloids and studied various processes related to adipocyte functionality. The presence of extracts resulted in reduced adipocyte differentiation, as well as neutral lipid content and rate of lipolysis. We observed that the intracellular fatty acid exchange was reduced in different LD size fractions upon treatment with BBR and Coptis chinensis. In addition, LD motility was decreased upon incubation with BBR, Coptis chinensis and Chelidonium majus extracts. Furthermore, Chelidonium majus was identified as a potent fatty acid uptake inhibitor. This is the first study that demonstrates the selected regulatory effects of herbal extracts on adipocyte function.
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Affiliation(s)
| | | | - Clemens Röhrl
- University of Applied Sciences Upper Austria, Wels, Austria.,Institute of Medical Chemistry, Center for Pathobiochemistry and Genetics, Medical University of Vienna, Vienna, Austria
| | - Flora Stübl
- University of Applied Sciences Upper Austria, Wels, Austria
| | - Jonas Schurr
- University of Applied Sciences Upper Austria, Hagenberg, Austria
| | - Bettina Schwarzinger
- Austrian Competence Center for Feed and Food Quality, Safety and Innovation, Wels, Austria
| | - Clemens Schwarzinger
- Johannes Kepler University, Institute for Chemical Technology of Organic Materials, Linz, Austria
| | | | - Stefan Wieser
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain
| | | | - Julian Weghuber
- University of Applied Sciences Upper Austria, Wels, Austria. .,Austrian Competence Center for Feed and Food Quality, Safety and Innovation, Wels, Austria.
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Velicky P, Meinhardt G, Plessl K, Vondra S, Weiss T, Haslinger P, Lendl T, Aumayr K, Mairhofer M, Zhu X, Schütz B, Hannibal RL, Lindau R, Weil B, Ernerudh J, Neesen J, Egger G, Mikula M, Röhrl C, Urban AE, Baker J, Knöfler M, Pollheimer J. Genome amplification and cellular senescence are hallmarks of human placenta development. PLoS Genet 2018; 14:e1007698. [PMID: 30312291 PMCID: PMC6200260 DOI: 10.1371/journal.pgen.1007698] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 10/24/2018] [Accepted: 09/17/2018] [Indexed: 12/16/2022] Open
Abstract
Genome amplification and cellular senescence are commonly associated with pathological processes. While physiological roles for polyploidization and senescence have been described in mouse development, controversy exists over their significance in humans. Here, we describe tetraploidization and senescence as phenomena of normal human placenta development. During pregnancy, placental extravillous trophoblasts (EVTs) invade the pregnant endometrium, termed decidua, to establish an adapted microenvironment required for the developing embryo. This process is critically dependent on continuous cell proliferation and differentiation, which is thought to follow the classical model of cell cycle arrest prior to terminal differentiation. Strikingly, flow cytometry and DNAseq revealed that EVT formation is accompanied with a genome-wide polyploidization, independent of mitotic cycles. DNA replication in these cells was analysed by a fluorescent cell-cycle indicator reporter system, cell cycle marker expression and EdU incorporation. Upon invasion into the decidua, EVTs widely lose their replicative potential and enter a senescent state characterized by high senescence-associated (SA) β-galactosidase activity, induction of a SA secretory phenotype as well as typical metabolic alterations. Furthermore, we show that the shift from endocycle-dependent genome amplification to growth arrest is disturbed in androgenic complete hydatidiform moles (CHM), a hyperplastic pregnancy disorder associated with increased risk of developing choriocarinoma. Senescence is decreased in CHM-EVTs, accompanied by exacerbated endoreduplication and hyperploidy. We propose induction of cellular senescence as a ploidy-limiting mechanism during normal human placentation and unravel a link between excessive polyploidization and reduced senescence in CHM.
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Affiliation(s)
- Philipp Velicky
- Department of Obstetrics and Gynaecology, Reproductive Biology Unit, Medical University of Vienna, Vienna, Austria
| | - Gudrun Meinhardt
- Department of Obstetrics and Gynaecology, Reproductive Biology Unit, Medical University of Vienna, Vienna, Austria
| | - Kerstin Plessl
- Department of Obstetrics and Gynaecology, Reproductive Biology Unit, Medical University of Vienna, Vienna, Austria
| | - Sigrid Vondra
- Department of Obstetrics and Gynaecology, Reproductive Biology Unit, Medical University of Vienna, Vienna, Austria
| | - Tamara Weiss
- Children's Cancer Research Institute, St. Anna Children´s Hospital, Vienna, Austria
| | - Peter Haslinger
- Department of Obstetrics and Gynaecology, Reproductive Biology Unit, Medical University of Vienna, Vienna, Austria
| | - Thomas Lendl
- Biooptics Facility of Institute of Molecular Pathology, Institute of Molecular Biotechnology and Gregor Mendel Institute, Vienna, Austria
| | - Karin Aumayr
- Biooptics Facility of Institute of Molecular Pathology, Institute of Molecular Biotechnology and Gregor Mendel Institute, Vienna, Austria
| | - Mario Mairhofer
- Department of Gynecological Endocrinology and Reproductive Medicine, Medical University of Vienna, Vienna, Austria
| | - Xiaowei Zhu
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, California, United States of America
| | - Birgit Schütz
- Center for Pathobiochemistry and Genetics, Medical University of Vienna, Vienna, Austria
| | - Roberta L. Hannibal
- Department of Genetics, Stanford University School of Medicine, Stanford, California, United States of America
| | - Robert Lindau
- Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
| | - Beatrix Weil
- Center for Pathobiochemistry and Genetics, Medical University of Vienna, Vienna, Austria
| | - Jan Ernerudh
- Department of Clinical Immunology and Transfusion Medicine, and Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
| | - Jürgen Neesen
- Center for Pathobiochemistry and Genetics, Medical University of Vienna, Vienna, Austria
| | - Gerda Egger
- Clinical Institute of Pathology, Medical University of Vienna, Vienna, Austria
| | - Mario Mikula
- Center for Pathobiochemistry and Genetics, Medical University of Vienna, Vienna, Austria
| | - Clemens Röhrl
- Center for Pathobiochemistry and Genetics, Medical University of Vienna, Vienna, Austria
| | - Alexander E. Urban
- Department of Psychiatry and Behavioral Sciences, Department of Genetics, Stanford University School of Medicine, Tasha and John Morgridge Faculty Scholar, Stanford Child Health Research Institute, Stanford, California, United States of America
| | - Julie Baker
- Department of Genetics, Stanford University School of Medicine, Stanford, California, United States of America
| | - Martin Knöfler
- Department of Obstetrics and Gynaecology, Reproductive Biology Unit, Medical University of Vienna, Vienna, Austria
| | - Jürgen Pollheimer
- Department of Obstetrics and Gynaecology, Reproductive Biology Unit, Medical University of Vienna, Vienna, Austria
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Hopkins PN, Brinton EA, Nanjee MN. Hyperlipoproteinemia type 3: the forgotten phenotype. Curr Atheroscler Rep 2015; 16:440. [PMID: 25079293 DOI: 10.1007/s11883-014-0440-2] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Hyperlipoproteinemia type 3 (HLP3) is caused by impaired removal of triglyceride-rich lipoproteins (TGRL) leading to accumulation of TGRL remnants with abnormal composition. High levels of these remnants, called β-VLDL, promote lipid deposition in tuberous xanthomas, atherosclerosis, premature coronary artery disease, and early myocardial infarction. Recent genetic and molecular studies suggest more genes than previously appreciated may contribute to the expression of HLP3, both through impaired hepatic TGRL processing or removal and increased TGRL production. HLP3 is often highly amenable to appropriate treatment. Nevertheless, most HLP3 probably goes undiagnosed, in part because of lack of awareness of the relatively high prevalence (about 0.2% in women and 0.4-0.5% in men older than 20 years) and largely because of infrequent use of definitive diagnostic methods.
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Affiliation(s)
- Paul N Hopkins
- Cardiovascular Genetics, Department of Internal Medicine, University of Utah, 420 Chipeta Way, Room 1160, Salt Lake City, UT, 84108, USA,
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6
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Zhao Y, Hoekstra M, Korporaal SJA, Van Berkel TJC, Van Eck M. HDL Receptor Scavenger Receptor BI. Atherosclerosis 2015. [DOI: 10.1002/9781118828533.ch25] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Lichtenstein L, Serhan N, Espinosa-Delgado S, Fabre A, Annema W, Tietge UJF, Robaye B, Boeynaems JM, Laffargue M, Perret B, Martinez LO. Increased atherosclerosis in P2Y13/apolipoprotein E double-knockout mice: contribution of P2Y13 to reverse cholesterol transport. Cardiovasc Res 2015; 106:314-23. [PMID: 25770145 DOI: 10.1093/cvr/cvv109] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Accepted: 03/07/2015] [Indexed: 11/14/2022] Open
Abstract
AIMS High-density lipoproteins (HDLs) protect against atherosclerosis mainly due to their function in hepatobiliary reverse cholesterol transport (RCT). This is a process whereby excess cholesterol from peripheral tissues is transported by HDL particles to the liver for further metabolism and biliary excretion. Hepatic uptake of HDL holoparticles involves the P2Y13 receptor, independently of the selective cholesteryl ester uptake mediated by scavenger receptor class B, type I (SR-BI). Accordingly, P2Y13-deficient mice (P2Y13 (-/-)) have impaired RCT. This study assessed whether P2Y13 deficiency would affect atherosclerotic development. METHODS AND RESULTS P2Y13 (-/-) mice were crossbred with atherosclerosis-prone apoE(-/-) mice. When 15 weeks old, P2Y13 (-/-)/apoE(-/-) mice had more aortic sinus lesions than apoE(-/-) mice. Bone marrow transplantation showed that the absence of the P2Y13 receptor in blood cells did not lead to significantly greater atherosclerotic plaque size formation compared with control apoE(-/-) reconstituted animals. Conversely, the absence of the P2Y13 receptor, except in blood cells, resulted in lesion sizes similar to that in P2Y13 (-/-)/apoE(-/-) reconstituted mice, pointing to a role for non-haematopoietic-derived P2Y13. Unexpectedly, P2Y13 (-/-)/apoE(-/-) mice displayed a lower HDL-cholesterol level than apoE(-/-) mice, which might be due to greater SR-BI expression in the liver. However, P2Y13 deficiency in apoE(-/-) mice was translated into reduced biliary and faecal sterol excretion and impaired RCT from macrophage to faeces, suggesting that an alteration in hepatobiliary RCT could be solely responsible for the greater atherosclerosis observed. CONCLUSION The P2Y13 receptor protects against atherosclerosis, primarily through its role in hepatobiliary RCT.
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Affiliation(s)
- Laeticia Lichtenstein
- INSERM, UMR 1048, Institut de Maladies Métaboliques et Cardiovasculaires, Toulouse, France Université de Toulouse III, UMR 1048, Toulouse, France
| | - Nizar Serhan
- INSERM, UMR 1048, Institut de Maladies Métaboliques et Cardiovasculaires, Toulouse, France Université de Toulouse III, UMR 1048, Toulouse, France
| | - Sara Espinosa-Delgado
- INSERM, UMR 1048, Institut de Maladies Métaboliques et Cardiovasculaires, Toulouse, France Université de Toulouse III, UMR 1048, Toulouse, France
| | - Aurélie Fabre
- INSERM, UMR 1048, Institut de Maladies Métaboliques et Cardiovasculaires, Toulouse, France Université de Toulouse III, UMR 1048, Toulouse, France
| | - Wijtske Annema
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Uwe J F Tietge
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Bernard Robaye
- Institute of Interdisciplinary Research, IRIBHM, Université Libre de Bruxelles, Gosselies, Belgium
| | - Jean-Marie Boeynaems
- Institute of Interdisciplinary Research, IRIBHM, Université Libre de Bruxelles, Gosselies, Belgium
| | - Muriel Laffargue
- INSERM, UMR 1048, Institut de Maladies Métaboliques et Cardiovasculaires, Toulouse, France Université de Toulouse III, UMR 1048, Toulouse, France
| | - Bertrand Perret
- INSERM, UMR 1048, Institut de Maladies Métaboliques et Cardiovasculaires, Toulouse, France Université de Toulouse III, UMR 1048, Toulouse, France CHU de Toulouse, Hôpital Purpan, Toulouse, France
| | - Laurent O Martinez
- INSERM, UMR 1048, Institut de Maladies Métaboliques et Cardiovasculaires, Toulouse, France Université de Toulouse III, UMR 1048, Toulouse, France CHU de Toulouse, Hôpital Purpan, Toulouse, France INSERM U1048, Bât. L3, Hôpital Rangueil, BP 84225, 31432 Toulouse cedex 04, France
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Huang H, McIntosh AL, Landrock KK, Landrock D, Storey SM, Martin GG, Gupta S, Atshaves BP, Kier AB, Schroeder F. Human FABP1 T94A variant enhances cholesterol uptake. Biochim Biophys Acta Mol Cell Biol Lipids 2015; 1851:946-55. [PMID: 25732850 DOI: 10.1016/j.bbalip.2015.02.015] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Revised: 02/19/2015] [Accepted: 02/20/2015] [Indexed: 01/09/2023]
Abstract
Although expression of the human liver fatty acid binding protein (FABP1) T94A variant alters serum lipoprotein cholesterol levels in human subjects, nothing is known whereby the variant elicits these effects. This issue was addressed by in vitro cholesterol binding assays using purified recombinant wild-type (WT) FABP1 T94T and T94A variant proteins and in cultured primary human hepatocytes expressing the FABP1 T94T (genotyped as TT) or T94A (genotyped as CC) proteins. The human FABP1 T94A variant protein had 3-fold higher cholesterol-binding affinity than the WT FABP1 T94T as shown by NBD-cholesterol fluorescence binding assays and by cholesterol isothermal titration microcalorimetry (ITC) binding assays. CC variant hepatocytes also exhibited 30% higher total FABP1 protein. HDL- and LDL-mediated NBD-cholesterol uptake was faster in CC variant than TT WT human hepatocytes. VLDL-mediated uptake of NBD-cholesterol did not differ between CC and TT human hepatocytes. The increased HDL- and LDL-mediated NBD-cholesterol uptake was not associated with any significant change in mRNA levels of SCARB1, LDLR, CETP, and LCAT encoding the key proteins in lipoprotein cholesterol uptake. Thus, the increased HDL- and LDL-mediated NBD-cholesterol uptake by CC hepatocytes may be associated with higher affinity of T94A protein for cholesterol and/or increased total T94A protein level.
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Affiliation(s)
- Huan Huang
- Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, TX 77843-4466, USA
| | - Avery L McIntosh
- Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, TX 77843-4466, USA
| | - Kerstin K Landrock
- Department of Pathobiology, Texas A&M University, TVMC, College Station, TX 77843-4467, USA
| | - Danilo Landrock
- Department of Pathobiology, Texas A&M University, TVMC, College Station, TX 77843-4467, USA
| | - Stephen M Storey
- Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, TX 77843-4466, USA
| | - Gregory G Martin
- Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, TX 77843-4466, USA
| | - Shipra Gupta
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
| | - Barbara P Atshaves
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
| | - Ann B Kier
- Department of Pathobiology, Texas A&M University, TVMC, College Station, TX 77843-4467, USA
| | - Friedhelm Schroeder
- Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, TX 77843-4466, USA.
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Mo D, Xu H, Zhou W, Yang Q, Yang J, Xiao B, Yang Q. Susceptibility gene for stroke or cerebral infarction in the Han population in Hunan Province of China. Neural Regen Res 2014; 8:1519-27. [PMID: 25206448 PMCID: PMC4107805 DOI: 10.3969/j.issn.1673-5374.2013.16.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2013] [Accepted: 05/20/2013] [Indexed: 12/16/2022] Open
Abstract
The scavenger receptor class B type I gene can protect against atherosclerosis; a mononucleotide polymorphism is associated with differences in blood lipid metabolism, postprandial serum lipid levels, insulin resistance, coronary artery disease and familial hyperlipidemia. In this study, the scavenger receptor class B type I gene exon 1 G4A gene polymorphism in atherosclerotic cerebral infarction patients, cerebral hemorrhage patients and normal controls was detected using the polymerase chain reaction-restriction fragment length polymorphism method. The results showed that the GA + AA genotype frequency of scavenger receptor class B type I gene G4A in atherosclerotic cerebral infarction patients was similar to that in cerebral hemorrhage patients and normal controls; however, the A allele frequency was significantly lower than that in normal controls. The serum level of high-density lipoprotein cholesterol in patients with the scavenger receptor class B type I gene G4A GA + AA genotype was significantly higher, while the serum level of low-density lipoprotein cholesterol was significantly lower than that in patients with the GG genotype, in both the atherosclerotic cerebral infarction and cerebral hemorrhage groups. The serum level of high-density lipoprotein cholesterol in patients with the scavenger receptor class B type I gene G4A GA + AA genotype was significantly higher, while the serum levels of low-density lipoprotein cholesterol and total cholesterol were significantly lower than those in normal controls with the GG genotype. Our experimental results suggest that the G4A polymorphism of the scavenger receptor class B type I gene is a possible predisposing risk factor for atherosclerotic cerebral infarction, and that it has no association with cerebral hemorrhage in the Han population in Hunan province of China. The A allele is possibly associated with the metabolism of high-density and low-density lipoprotein cholesterol.
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Affiliation(s)
- Danheng Mo
- Department of Neurology, Hunan Provincial Mawangdui Hospital, Changsha 410016, Hunan Province, China
| | - Hongwei Xu
- Department of Neurology, Xiangya Hospital, Central South University, Changsha 410008, Hunan Province, China
| | - Wensheng Zhou
- Department of Neurology, Hunan Provincial Mawangdui Hospital, Changsha 410016, Hunan Province, China
| | - Qiming Yang
- Department of Neurology, Hunan Provincial Mawangdui Hospital, Changsha 410016, Hunan Province, China
| | - Jianwen Yang
- Department of Neurology, Hunan Provincial Mawangdui Hospital, Changsha 410016, Hunan Province, China
| | - Bo Xiao
- Department of Neurology, Xiangya Hospital, Central South University, Changsha 410008, Hunan Province, China
| | - Qidong Yang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha 410008, Hunan Province, China
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Westhaus S, Bankwitz D, Ernst S, Rohrmann K, Wappler I, Agné C, Luchtefeld M, Schieffer B, Sarrazin C, Manns MP, Pietschmann T, Ciesek S, von Hahn T. Characterization of the inhibition of hepatitis C virus entry by in vitro-generated and patient-derived oxidized low-density lipoprotein. Hepatology 2013; 57:1716-24. [PMID: 23212706 DOI: 10.1002/hep.26190] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Revised: 11/14/2012] [Accepted: 11/15/2012] [Indexed: 12/14/2022]
Abstract
UNLABELLED Oxidized low-density lipoprotein (oxLDL) has been reported as an inhibitor of hepatitis C virus (HCV) cell entry, making it the only known component of human lipid metabolism with an antiviral effect on HCV. However, several questions remain open, including its effect on full-length cell-culture-grown HCV (HCVcc) of different genotypes or on other steps of the viral replication cycle, its mechanism of action, and whether endogenous oxLDL shares the anti-HCV properties of in vitro-generated oxLDL. We combined molecular virology tools with oxLDL serum measurements in different patient cohorts to address these questions. We found that oxLDL inhibits HCVcc at least as potently as HCV pseudoparticles. There was moderate variation between genotypes, with genotype 4 appearing the most oxLDL sensitive. Intracellular RNA replication and assembly and release of new particles were unaffected. HCV particles entering target cells lost oxLDL sensitivity with time kinetics parallel to anti-SR-BI (scavenger receptor class B type I), but significantly earlier than anti-CD81, suggesting that oxLDL acts by perturbing interaction between HCV and SR-BI. Finally, in chronically HCV-infected individuals, endogenous serum oxLDL levels did not correlate with viral load, but in HCV-negative sera, high endogenous oxLDL had a negative effect on HCV infectivity in vitro. CONCLUSION oxLDL is a potent pangenotype HCV entry inhibitor that maintains its activity in the context of human serum and targets an early step of HCV entry.
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Affiliation(s)
- Sandra Westhaus
- Institute for Molecular Biology, Medizinische Hochschule Hannover, Hannover, Germany
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12
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Röhrl C, Pagler TA, Strobl W, Ellinger A, Neumüller J, Pavelka M, Stangl H, Meisslitzer-Ruppitsch C. Characterization of endocytic compartments after holo-high density lipoprotein particle uptake in HepG2 cells. Histochem Cell Biol 2010; 133:261-72. [PMID: 20039053 PMCID: PMC3182552 DOI: 10.1007/s00418-009-0672-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/15/2009] [Indexed: 12/27/2022]
Abstract
Holo-high density lipoprotein (HDL) particle uptake, besides selective lipid uptake, constitutes an alternative pathway to regulate cellular cholesterol homeostasis. In the current study, the cellular path of holo-HDL particles was investigated in human liver carcinoma cells (HepG2) using combined light and electron microscopical methods. The apolipoprotein moiety of HDL was visualized with different markers: horseradish peroxidase, colloidal gold and the fluorochrome Alexa(568), used in fluorescence microscopy and after photooxidation correlatively at the ultrastructural level. Time course experiments showed a rapid uptake of holo-HDL particles, an accumulation in endosomal compartments, with a plateau after 1-2 h of continuous uptake, and a clearance 1-2 h upon replacement by unlabeled HDL. Correlative microscopy, using HDL-Alexa(568)-driven diaminobenzidine (DAB) photooxidation, identified the fluorescent organelles as DAB-positive multivesicular bodies (MVBs) in the electron microscope; their luminal contents but not the internal vesicles were stained. Labeled MVBs increased in numbers and changed shapes along with the duration of uptake, from polymorphic organelles with multiple surface domains and differently shaped protrusions dominating at early times of uptake to compact bodies with mainly tubular appendices and densely packed vesicles after later times. Differently shaped and labeled surface domains and appendices, as revealed by three dimensional reconstructions, as well as images of homotypic fusions indicate the dynamics of the HDL-positive MVBs. Double staining visualized by confocal microscopy, along with the electron microscopic data, shows that holo-HDL particles after temporal storage in MVBs are only to a minor degree transported to lysosomes, which suggests that different mechanisms are involved in cellular HDL clearance, including resecretion.
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Affiliation(s)
- Clemens Röhrl
- Center for Physiology and Pathophysiology, Institute of Medical Chemistry, Medical University of Vienna, Vienna, Austria
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