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Chauhan T, Mittal RD, Mittal B. Association of Common Single Nucleotide Polymorphisms of Candidate Genes with Gallstone Disease: A Meta-Analysis. Indian J Clin Biochem 2020; 35:290-311. [PMID: 32647408 DOI: 10.1007/s12291-019-00832-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2019] [Accepted: 05/04/2019] [Indexed: 12/22/2022]
Abstract
Numerous studies have investigated the relationship between various candidate gene polymorphisms and gallbladder stone disease (GSD) across ethnic populations; however, the results are often inconsistent. This meta-analysis aims to comprehensively evaluate the influence of common ABCG8 T400K, ABCG8 D19H, ABCG8 C54Y, ApoB100 EcoRI, ApoB100 XbaI, ApoE HhaI, CETP TaqI, CYP7A1 Bsa, LRPAP1 I/D and TNF-α A308G polymorphisms on the risk of gallbladder stone disease. 33 Full-text articles with 9250 cases and 12,029 healthy controls (total 21,279 subjects) were analyzed using the RevMan software (V5.1) and the Comprehensive Meta-analysis software (Version 2.0, BIOSTAT, Englewood, NJ) a Random-effects model was applied. Begg's funnel plots, Fail-safe number, Egger's regression intercept and Begg and Mazumdar rank correlation tests were performed for the potential publication bias and sensitivity analysis. The studies were also sub-grouped into European and non-European groups to find out role of ethnicity, if any, on GSD risk. Studies included in quantitative synthesis were ABCG8 T400K rs4148217 (cases/controls, n = 671/1416) (4 studies), ABCG8 D19H rs11887534 (n = 1633/2306) (8 studies), ABCG8 C54Y rs4148211 (n = 445/1194) (3 studies), ApoB100 EcoRI rs1042031 (n = 503/390) (4 studies), ApoB100 XbaI rs693 (n = 1214/1389) (9 studies), ApoE HhaI rs429358 (n = 1335/1482) (12 studies), CETP TaqI rs708272 (n = 1038/1025) (5 studies), CYP7A1 Bsa rs3808607 (n = 565/514) (3 studies), LRPAP1 I/D rs11267919 (n = 849/900) (3 studies), TNF-α A308G rs1800629 (n = 997/1413) (3 studies). The combined results displayed significant association of ABCG8 D19H (GC + CC) [OR with 95%CI = 2.2(1.7-2.8); p < 0.00001], ABCG8 Y54C (GA + GG) [OR with 95%CI = 0.65(0.5-0.9); p = 0.01]. APOB100 EcoRI (GG vs. AA) [OR with 95%CI = 0.51(0.3-0.9); p = 0.05], (GG vs. GA) [OR with 95%CI = 0.6(0.4-0.9); p = 0.04], (GA + AA) [OR with 95%CI = 0.6(0.4-0.9); p = 0.006]. APOB Xba I (X- vs. X+) [OR with 95%CI = 0.53(0.3-0.8); p = 0.006. APOE Hha I (E4/E4 vs. E3/E3) [OR with 95%CI = 3.5(1.1-14.9); p = 0.04] and LRPAP1 I/D (ID + II) [OR with 95%CI = 1.27(1.0-1.6); p = 0.03] with the GSD risk. It was found that ABCG D19H was significantly associated with GSD in both European and Non-European populations. While APOB XbaI and LRPAP1 I/D markers were associated with gallstone disease only in Non- European population. Additionally, APOE HhaI and APOB 100 ECoRI were found to be associated with GSD only in European population. The results of quantitative synthesis suggest that the ABCG8 D19H polymorphism was associated with the increased risk of GSD in both European and Non-European populations, APOE Hha I and LRPAP1 I/D polymorphisms were associated with the increased risk of GSD in European and Non-European population respectively. However, no association was found in ABCG8 T400K, CETP Taq1, CYP7A1 Bsa and TNF-A308G polymorphisms with Gallstone Disease.
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Affiliation(s)
- Tripty Chauhan
- Department of Biotechnology, Babasaheb Bhimrao Ambedkar University, Lucknow, UP India
| | - R D Mittal
- Department of Urology, SGPGIMS, Lucknow, UP India
| | - B Mittal
- Department of Biotechnology, Babasaheb Bhimrao Ambedkar University, Lucknow, UP India
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Chen WY, Chen YF, Chan HC, Chung CH, Peng HY, Ho YC, Chen CH, Chang KC, Tang CH, Lee AS. Role of apolipoprotein E in electronegative low-density lipoprotein-induced mitochondrial dysfunction in cardiomyocytes. Metabolism 2020; 107:154227. [PMID: 32275974 DOI: 10.1016/j.metabol.2020.154227] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 03/18/2020] [Accepted: 04/07/2020] [Indexed: 12/23/2022]
Abstract
OBJECTIVE L5, a highly electronegative subtype of low-density lipoprotein (LDL), is likely associated with the development of atherosclerosis and cardiovascular diseases. Normal LDL is composed mainly of apolipoprotein (Apo) B, but L5 has additional proteins such as ApoE. We previously demonstrated that L5 induces endothelial cell senescence by increasing mitochondrial reactive oxygen species. In the present study, we examined the effect of L5 on mitochondrial function in cardiomyocytes. METHODS We used the Seahorse XF24 extracellular flux analyzer to examine the effect of L5 and its components on mitochondrial energy production. The effects of L5 on mitochondrial morphology were examined by immunofluorescence using MitoTracker Green FM and the corresponding probes in H9c2 cardiomyoblasts. Mitochondrial permeability was assessed by using a calcium-induced swelling assay with a voltage-dependent anion-selective channel (VDAC) inhibitor to determine VDAC-dependence both in vitro and in vivo. L5 without ApoE, referred to as △L5, was used to clarify the role of ApoE in L5-induced mitochondrial dysfunction. RESULTS L5 not only significantly decreased basal (P < 0.05) and maximal respiration (P < 0.01) but also reduced spare respiratory capacity (P < 0.01) in H9c2 cells. Additionally, L5 caused phosphorylation of Drp1 and mitochondrial fission. Recombinant ApoE mimicked the mitochondrial effects of L5, but △L5 did not cause similar effects. After entering cells, ApoE on L5 colocalized with mitochondrial VDAC and caused mitochondria swelling both in vitro and in vivo. This effect was also seen with recombinant ApoE but not △L5. CONCLUSIONS ApoE may play an important role in electronegative LDL-induced mitochondrial dysfunction through the opening of the mitochondrial permeability transition pore via the interaction of ApoE and VDAC.
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Affiliation(s)
- Wei-Yu Chen
- Graduate Institute of Basic Medical Science, China Medical University, Taichung 40402, Taiwan; Department of Medicine, Mackay Medical College, New Taipei City 25245, Taiwan; Cardiovascular Research Laboratory, China Medical University Hospital, Taichung 40447, Taiwan
| | - Yun-Fang Chen
- Department of Medicine, Mackay Medical College, New Taipei City 25245, Taiwan; Cardiovascular Research Laboratory, China Medical University Hospital, Taichung 40447, Taiwan; Department of Chinese Pharmaceutical Sciences and Chinese Medicine Resources, China Medical University, Taichung 40402, Taiwan
| | - Hua-Cheng Chan
- Center for Lipid Biosciences, Kaohsiung Medical University Hospital, Kaohsiung 80756, Taiwan
| | - Ching-Hu Chung
- Department of Medicine, Mackay Medical College, New Taipei City 25245, Taiwan
| | - Hsien-Yu Peng
- Department of Medicine, Mackay Medical College, New Taipei City 25245, Taiwan
| | - Yu-Cheng Ho
- Department of Medicine, Mackay Medical College, New Taipei City 25245, Taiwan.
| | - Chu-Huang Chen
- Center for Lipid Biosciences, Kaohsiung Medical University Hospital, Kaohsiung 80756, Taiwan; Vascular and Medicinal Research, Texas Heart Institute, Houston, TX 77030, USA; New York Heart Research Foundation, Mineola, New York 11501, USA.
| | - Kuan-Cheng Chang
- Cardiovascular Research Laboratory, China Medical University Hospital, Taichung 40447, Taiwan
| | - Chih-Hsin Tang
- Department of Pharmacology, School of Medicine, China Medical University, Taichung 40402, Taiwan.
| | - An-Sheng Lee
- Department of Medicine, Mackay Medical College, New Taipei City 25245, Taiwan; Cardiovascular Research Laboratory, China Medical University Hospital, Taichung 40447, Taiwan.
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Marais AD. Apolipoprotein E in lipoprotein metabolism, health and cardiovascular disease. Pathology 2018; 51:165-176. [PMID: 30598326 DOI: 10.1016/j.pathol.2018.11.002] [Citation(s) in RCA: 176] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 10/31/2018] [Accepted: 11/01/2018] [Indexed: 12/16/2022]
Abstract
Apolipoprotein E (apoE), a 34 kDa circulating glycoprotein of 299 amino acids, predominantly synthesised in the liver, associates with triglyceride-rich lipoproteins to mediate the clearance of their remnants after enzymatic lipolysis in the circulation. Its synthesis in macrophages initiates the formation of high density-like lipoproteins to effect reverse cholesterol transport to the liver. In the nervous system apoE forms similar lipoproteins which perform the function of distributing lipids amongst cells. ApoE accounts for much of the variation in plasma lipoproteins by three common variants (isoforms) that influence low-density lipoprotein concentration and the risk of atherosclerosis. ApoE2 generally is most favourable and apoE4 least favourable for cardiovascular and neurological health. The apoE variants relate to different amino acids at positions 112 and 158: cysteine in both for apoE2, arginine at both sites for apoE4, and respectively cysteine and arginine for apoE3 that is viewed as the wild type. Paradoxically, under metabolic stress, homozygosity for apoE2 may result in dysbetalipoproteinaemia in adults owing to impaired binding of remnant lipoproteins to the LDL receptor and related proteins as well as heparan sulphate proteoglycans. This highly atherogenic condition is also seen with other mutations in apoE, but with autosomal dominant inheritance. Mutations in apoE may also cause lipoprotein glomerulopathy. In the central nervous system apoE binds amyloid β-protein and tau protein and fragments may incur cellular damage. ApoE4 is a strong risk factor for the development of Alzheimer's disease. ApoE has several other physiological effects that may influence health and disease, including supply of docosahexaenoic acid for the brain and modulating immune and inflammatory responses. Genotyping of apoE may have application in disorders of lipoprotein metabolism as well as glomerulopathy and may be relevant to personalised medicine in understanding cardiovascular risk, and the outcome of nutritional and therapeutic interventions. Quantitation of apoE will probably not be clinically useful. ApoE is also of interest as it may generate peptides with biological function and could be employed in nanoparticles that may allow crossing of the blood-brain barrier. Therapeutic options may emerge from these newer insights.
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Affiliation(s)
- A David Marais
- Chemical Pathology Division, Pathology Department, University of Cape Town Health Science Faculty and National Health Laboratory Service, Cape Town, South Africa.
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Tumor-associated macrophages-derived exosomes promote the migration of gastric cancer cells by transfer of functional Apolipoprotein E. Cell Death Dis 2018; 9:434. [PMID: 29567987 PMCID: PMC5864742 DOI: 10.1038/s41419-018-0465-5] [Citation(s) in RCA: 237] [Impact Index Per Article: 39.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Revised: 02/12/2018] [Accepted: 03/07/2018] [Indexed: 12/11/2022]
Abstract
Tumor-associated macrophages (TAMs) are a major component of the tumor microenvironment and have been shown to contribute to tumor aggressiveness. However, the detailed mechanisms underlying the pro-metastatic effect of TAMs on gastric cancer are not clearly defined. Here, we show that TAMs are enriched in gastric cancer. TAMs are characterized by M2-polarized phenotype and promote migration of gastric cancer cells in vitro and in vivo. Furthermore, we find that M2-derived exosomes determine the TAMs-mediated pro-migratory activity. Using mass spectrometry, we identify that apolipoprotein E (ApoE) is highly specific and effective protein in M2 macrophages-derived exosomes. Moreover, TAMs are uniquely immune cells population expressed ApoE in gastric cancer microenvironment. However, exosomes derived from M2 macrophages of Apoe−/− mice have no significant effect on the migration of gastric cancer cells in vitro and in vivo. Mechanistically, M2 macrophage-derived exosomes mediate an intercellular transfer of ApoE-activating PI3K-Akt signaling pathway in recipient gastric cancer cells to remodel the cytoskeleton-supporting migration. Collectively, our findings signify that the exosome-mediated transfer of functional ApoE protein from TAMs to the tumor cells promotes the migration of gastric cancer cells.
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Chang CL, Garcia-Arcos I, Nyrén R, Olivecrona G, Kim JY, Hu Y, Agrawal RR, Murphy AJ, Goldberg IJ, Deckelbaum RJ. Lipoprotein Lipase Deficiency Impairs Bone Marrow Myelopoiesis and Reduces Circulating Monocyte Levels. Arterioscler Thromb Vasc Biol 2018; 38:509-519. [PMID: 29371243 DOI: 10.1161/atvbaha.117.310607] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Accepted: 01/10/2018] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Tissue macrophages induce and perpetuate proinflammatory responses, thereby promoting metabolic and cardiovascular disease. Lipoprotein lipase (LpL), the rate-limiting enzyme in blood triglyceride catabolism, is expressed by macrophages in atherosclerotic plaques. We questioned whether LpL, which is also expressed in the bone marrow (BM), affects circulating white blood cells and BM proliferation and modulates macrophage retention within the artery. APPROACH AND RESULTS We characterized blood and tissue leukocytes and inflammatory molecules in transgenic LpL knockout mice rescued from lethal hypertriglyceridemia within 18 hours of life by muscle-specific LpL expression (MCKL0 mice). LpL-deficient mice had ≈40% reduction in blood white blood cell, neutrophils, and total and inflammatory monocytes (Ly6C/Ghi). LpL deficiency also significantly decreased expression of BM macrophage-associated markers (F4/80 and TNF-α [tumor necrosis factor α]), master transcription factors (PU.1 and C/EBPα), and colony-stimulating factors (CSFs) and their receptors, which are required for monocyte and monocyte precursor proliferation and differentiation. As a result, differentiation of macrophages from BM-derived monocyte progenitors and monocytes was decreased in MCKL0 mice. Furthermore, although LpL deficiency was associated with reduced BM uptake and accumulation of triglyceride-rich particles and macrophage CSF-macrophage CSF receptor binding, triglyceride lipolysis products (eg, linoleic acid) stimulated expression of macrophage CSF and macrophage CSF receptor in BM-derived macrophage precursor cells. Arterial macrophage numbers decreased after heparin-mediated LpL cell dissociation and by genetic knockout of arterial LpL. Reconstitution of LpL-expressing BM replenished aortic macrophage density. CONCLUSIONS LpL regulates peripheral leukocyte levels and affects BM monocyte progenitor differentiation and aortic macrophage accumulation.
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Affiliation(s)
- Chuchun L Chang
- From Institute of Human Nutrition (C.L.C., J.Y.K., R.R.A., R.J.D.), Division of Preventive Medicine and Nutrition, Department of Medicine (I.G.-A.), Division of Molecular Medicine, Department of Medicine (Y.H., A.J.M., I.J.G.), and Department of Pediatrics (R.J.D.), College of Physicians and Surgeons, Columbia University, New York; Department of Medical Biosciences/Physiological Chemistry, Umeå University, Sweden (R.N., G.O.); Division of Endocrinology, Diabetes, and Metabolism, New York University School of Medicine, New York (Y.H., I.J.G.); Haematopoiesis and Leukocyte Biology, Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia (A.J.M.); and Department of Immunology, Monash University, Melbourne, Victoria, Australia (A.J.M.)
| | - Itsaso Garcia-Arcos
- From Institute of Human Nutrition (C.L.C., J.Y.K., R.R.A., R.J.D.), Division of Preventive Medicine and Nutrition, Department of Medicine (I.G.-A.), Division of Molecular Medicine, Department of Medicine (Y.H., A.J.M., I.J.G.), and Department of Pediatrics (R.J.D.), College of Physicians and Surgeons, Columbia University, New York; Department of Medical Biosciences/Physiological Chemistry, Umeå University, Sweden (R.N., G.O.); Division of Endocrinology, Diabetes, and Metabolism, New York University School of Medicine, New York (Y.H., I.J.G.); Haematopoiesis and Leukocyte Biology, Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia (A.J.M.); and Department of Immunology, Monash University, Melbourne, Victoria, Australia (A.J.M.)
| | - Rakel Nyrén
- From Institute of Human Nutrition (C.L.C., J.Y.K., R.R.A., R.J.D.), Division of Preventive Medicine and Nutrition, Department of Medicine (I.G.-A.), Division of Molecular Medicine, Department of Medicine (Y.H., A.J.M., I.J.G.), and Department of Pediatrics (R.J.D.), College of Physicians and Surgeons, Columbia University, New York; Department of Medical Biosciences/Physiological Chemistry, Umeå University, Sweden (R.N., G.O.); Division of Endocrinology, Diabetes, and Metabolism, New York University School of Medicine, New York (Y.H., I.J.G.); Haematopoiesis and Leukocyte Biology, Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia (A.J.M.); and Department of Immunology, Monash University, Melbourne, Victoria, Australia (A.J.M.)
| | - Gunilla Olivecrona
- From Institute of Human Nutrition (C.L.C., J.Y.K., R.R.A., R.J.D.), Division of Preventive Medicine and Nutrition, Department of Medicine (I.G.-A.), Division of Molecular Medicine, Department of Medicine (Y.H., A.J.M., I.J.G.), and Department of Pediatrics (R.J.D.), College of Physicians and Surgeons, Columbia University, New York; Department of Medical Biosciences/Physiological Chemistry, Umeå University, Sweden (R.N., G.O.); Division of Endocrinology, Diabetes, and Metabolism, New York University School of Medicine, New York (Y.H., I.J.G.); Haematopoiesis and Leukocyte Biology, Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia (A.J.M.); and Department of Immunology, Monash University, Melbourne, Victoria, Australia (A.J.M.)
| | - Ji Young Kim
- From Institute of Human Nutrition (C.L.C., J.Y.K., R.R.A., R.J.D.), Division of Preventive Medicine and Nutrition, Department of Medicine (I.G.-A.), Division of Molecular Medicine, Department of Medicine (Y.H., A.J.M., I.J.G.), and Department of Pediatrics (R.J.D.), College of Physicians and Surgeons, Columbia University, New York; Department of Medical Biosciences/Physiological Chemistry, Umeå University, Sweden (R.N., G.O.); Division of Endocrinology, Diabetes, and Metabolism, New York University School of Medicine, New York (Y.H., I.J.G.); Haematopoiesis and Leukocyte Biology, Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia (A.J.M.); and Department of Immunology, Monash University, Melbourne, Victoria, Australia (A.J.M.)
| | - Yunying Hu
- From Institute of Human Nutrition (C.L.C., J.Y.K., R.R.A., R.J.D.), Division of Preventive Medicine and Nutrition, Department of Medicine (I.G.-A.), Division of Molecular Medicine, Department of Medicine (Y.H., A.J.M., I.J.G.), and Department of Pediatrics (R.J.D.), College of Physicians and Surgeons, Columbia University, New York; Department of Medical Biosciences/Physiological Chemistry, Umeå University, Sweden (R.N., G.O.); Division of Endocrinology, Diabetes, and Metabolism, New York University School of Medicine, New York (Y.H., I.J.G.); Haematopoiesis and Leukocyte Biology, Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia (A.J.M.); and Department of Immunology, Monash University, Melbourne, Victoria, Australia (A.J.M.)
| | - Rishi R Agrawal
- From Institute of Human Nutrition (C.L.C., J.Y.K., R.R.A., R.J.D.), Division of Preventive Medicine and Nutrition, Department of Medicine (I.G.-A.), Division of Molecular Medicine, Department of Medicine (Y.H., A.J.M., I.J.G.), and Department of Pediatrics (R.J.D.), College of Physicians and Surgeons, Columbia University, New York; Department of Medical Biosciences/Physiological Chemistry, Umeå University, Sweden (R.N., G.O.); Division of Endocrinology, Diabetes, and Metabolism, New York University School of Medicine, New York (Y.H., I.J.G.); Haematopoiesis and Leukocyte Biology, Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia (A.J.M.); and Department of Immunology, Monash University, Melbourne, Victoria, Australia (A.J.M.)
| | - Andrew J Murphy
- From Institute of Human Nutrition (C.L.C., J.Y.K., R.R.A., R.J.D.), Division of Preventive Medicine and Nutrition, Department of Medicine (I.G.-A.), Division of Molecular Medicine, Department of Medicine (Y.H., A.J.M., I.J.G.), and Department of Pediatrics (R.J.D.), College of Physicians and Surgeons, Columbia University, New York; Department of Medical Biosciences/Physiological Chemistry, Umeå University, Sweden (R.N., G.O.); Division of Endocrinology, Diabetes, and Metabolism, New York University School of Medicine, New York (Y.H., I.J.G.); Haematopoiesis and Leukocyte Biology, Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia (A.J.M.); and Department of Immunology, Monash University, Melbourne, Victoria, Australia (A.J.M.)
| | - Ira J Goldberg
- From Institute of Human Nutrition (C.L.C., J.Y.K., R.R.A., R.J.D.), Division of Preventive Medicine and Nutrition, Department of Medicine (I.G.-A.), Division of Molecular Medicine, Department of Medicine (Y.H., A.J.M., I.J.G.), and Department of Pediatrics (R.J.D.), College of Physicians and Surgeons, Columbia University, New York; Department of Medical Biosciences/Physiological Chemistry, Umeå University, Sweden (R.N., G.O.); Division of Endocrinology, Diabetes, and Metabolism, New York University School of Medicine, New York (Y.H., I.J.G.); Haematopoiesis and Leukocyte Biology, Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia (A.J.M.); and Department of Immunology, Monash University, Melbourne, Victoria, Australia (A.J.M.).
| | - Richard J Deckelbaum
- From Institute of Human Nutrition (C.L.C., J.Y.K., R.R.A., R.J.D.), Division of Preventive Medicine and Nutrition, Department of Medicine (I.G.-A.), Division of Molecular Medicine, Department of Medicine (Y.H., A.J.M., I.J.G.), and Department of Pediatrics (R.J.D.), College of Physicians and Surgeons, Columbia University, New York; Department of Medical Biosciences/Physiological Chemistry, Umeå University, Sweden (R.N., G.O.); Division of Endocrinology, Diabetes, and Metabolism, New York University School of Medicine, New York (Y.H., I.J.G.); Haematopoiesis and Leukocyte Biology, Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia (A.J.M.); and Department of Immunology, Monash University, Melbourne, Victoria, Australia (A.J.M.).
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Radiolabeled cholesteryl ethers: A need to analyze for biological stability before use. Biochem Biophys Rep 2017; 13:1-6. [PMID: 29188234 PMCID: PMC5697731 DOI: 10.1016/j.bbrep.2017.10.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Accepted: 10/23/2017] [Indexed: 11/22/2022] Open
Abstract
Radiolabeled cholesteryl ethers are widely used as non-metabolizable tracers for lipoproteins and lipid emulsions in a variety of in vitro and in vivo experiments. Since cholesteryl ethers do not leave cells after uptake and are not hydrolyzed by mammalian cellular enzymes, these compounds can act as markers for cumulative cell uptakes of labeled particles. We have employed [3H]cholesteryl oleoyl ether to study the uptake and distribution of triglyceride-rich emulsion particles on animal models. However, questionable unexpected results compelled us to analyze the stability of these ethers. We tested the stability of two commercially available radiolabeled cholesteryl ethers - [3H]cholesteryl oleoyl ether and [3H]cholesteryl hexadecyl ether from different suppliers, employing in vitro, in vivo and chemical model systems. Our results show that, among the two cholesteryl ethers tested, one ether was hydrolyzed to free cholesterol in vitro, in vivo and chemically under alkaline hydrolyzing agent. Free cholesterol, unlike cholesteryl ether, can then re-enter the circulation leading to confounding results. The other ether was not hydrolyzed to free cholesterol and remained as a stable ether. Hence, radiolabeled cholesteryl ethers should be analyzed for biological stability before utilizing them for in vitro or in vivo experiments. Tested stability of two commercially available radiolabeled cholesteryl ethers. One ether was hydrolyzed to free cholesterol (FC) in vitro and in vivo. FC, re-entered circulation giving questionable unexpected results in experiments. The other ether was unhydrolyzed in all model systems. Radiolabeled cholesteryl ethers should be analyzed for stability before use.
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Tian Y, Wang J, Ye Y, Sun L, Fan Y, Wang L, Li J, Wang Z, Wang K. Apolipoprotein E polymorphism and colorectal neoplasm: results from a meta-analysis. PLoS One 2014; 9:e102477. [PMID: 25029444 PMCID: PMC4100903 DOI: 10.1371/journal.pone.0102477] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Accepted: 06/19/2014] [Indexed: 11/18/2022] Open
Abstract
To investigate the relationship of Apolipoprotein E (APOE) gene polymorphism to colorectal neoplasia (CRN), we performed a systematic review and meta-analysis. Eligible studies were identified through a systematic literature review from PubMed, EMBASE, and the Science Citation Index up to February 2014. A combined analysis was performed, followed by a subgroup analyses stratified by the study design. We used data collected from 8 prospective studies involving respectively a total of 9243 participants and 4310 CRN cases which including 438 patients with colorectal adenoma (CRA), and 3873 patients with colorectal carcinoma (CRC). The pooled data from this meta-analysis indicated there was no significant association between APOE polymorphism and CRN (ε2: P = 0.51, OR 1.04 95% CI 0.93 to 1.16; ε4: P = 0.72, OR 0.98 95% CI 0.90 to 1.07). Interestingly, subgroup analysis demonstrated there was a significant decreased risk for proximal CRN in patients with APOE ε4 (P = 0.0007, OR 0.52 95% CI 0.35 to 0.76). Data showed no significant association between APOE genotype and overall CRN. However, compared with those carry APOE ε3 alleles, persons with APOE ε4 genotype have significant decreased risk suffering from proximal CRN but not from distal CRN.
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Affiliation(s)
- Yun Tian
- Department of Oncology, the Second Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, PR China
| | - Jirong Wang
- Department of Oncology, the Second Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, PR China
| | - Ying Ye
- Emergency Center, Affiliated Hospital of Xuzhou Medical College, Xuzhou, Jiangsu, PR China
| | - Liqun Sun
- Department of Intensive Care Unit, the Second Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, PR China
| | - Yingrui Fan
- Department of Oncology, the Second Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, PR China
| | - Li Wang
- Department of Oncology, the Second Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, PR China
| | - Juan Li
- Department of Oncology, the Second Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, PR China
| | - Zhaoxia Wang
- Department of Oncology, the Second Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, PR China
| | - Keming Wang
- Department of Oncology, the Second Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, PR China
- * E-mail:
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Wu CL, Zhao SP, Yu BL. Intracellular role of exchangeable apolipoproteins in energy homeostasis, obesity and non-alcoholic fatty liver disease. Biol Rev Camb Philos Soc 2014; 90:367-76. [PMID: 24834836 DOI: 10.1111/brv.12116] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Revised: 04/10/2014] [Accepted: 04/17/2014] [Indexed: 02/06/2023]
Affiliation(s)
- Chen-Lu Wu
- Department of Cardiology; The Second Xiangya Hospital, Central South University; Changsha Hunan 410011 China
| | - Shui-Ping Zhao
- Department of Cardiology; The Second Xiangya Hospital, Central South University; Changsha Hunan 410011 China
| | - Bi-Lian Yu
- Department of Cardiology; The Second Xiangya Hospital, Central South University; Changsha Hunan 410011 China
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ApoE influences amyloid-β (Aβ) clearance despite minimal apoE/Aβ association in physiological conditions. Proc Natl Acad Sci U S A 2013; 110:E1807-16. [PMID: 23620513 DOI: 10.1073/pnas.1220484110] [Citation(s) in RCA: 384] [Impact Index Per Article: 34.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Apolipoprotein E gene (APOE) alleles may shift the onset of Alzheimer's disease (AD) through apoE protein isoforms changing the probability of amyloid-β (Aβ) accumulation. It has been proposed that differential physical interactions of apoE isoforms with soluble Aβ (sAβ) in brain fluids influence the metabolism of Aβ, providing a mechanism to account for how APOE influences AD risk. In contrast, we provide clear evidence that apoE and sAβ interactions occur minimally in solution and in the cerebrospinal fluid of human subjects, producing apoE3 and apoE4 isoforms as assessed by multiple biochemical and analytical techniques. Despite minimal extracellular interactions with sAβ in fluid, we find that apoE isoforms regulate the metabolism of sAβ by astrocytes and in the interstitial fluid of mice that received apoE infusions during brain Aβ microdialysis. We find that a significant portion of apoE and sAβ compete for the low-density lipoprotein receptor-related protein 1 (LRP1)-dependent cellular uptake pathway in astrocytes, providing a mechanism to account for apoE's regulation of sAβ metabolism despite minimal evidence of direct interactions in extracellular fluids. We propose that apoE influences sAβ metabolism not through direct binding to sAβ in solution but through its actions with other interacting receptors/transporters and cell surfaces. These results provide an alternative frame work for the mechanistic explanations on how apoE isoforms influence the risk of AD pathogenesis.
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A meta-analysis of apolipoprotein E gene ε2/ε3/ε4 polymorphism for gallbladder stone disease. PLoS One 2012; 7:e45849. [PMID: 23049877 PMCID: PMC3458111 DOI: 10.1371/journal.pone.0045849] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2012] [Accepted: 08/23/2012] [Indexed: 01/11/2023] Open
Abstract
Background Numerous studies have investigated the relationship between apolipoprotein (Apo) E gene polymorphisms and gallbladder stone disease (GSD) across ethnic populations; however, the results are often inconsistent. This meta-analysis aims to comprehensively evaluate the influence of a common ε2/ε3/ε4 polymorphism in Apo E gene on the risk of gallbladder stone disease. Method Data were analyzed using the RevMan software (V5.1) and a random-effects model was applied irrespective of between-study heterogeneity. Publication bias was weighed using the fail-safe number. Results There were 17 study populations totaling 1773 cases and 2751 controls for ε2/ε3/ε4 polymorphism of Apo E gene. Overall comparison of alleles ε2 with ε3 in all study populations yielded a 16% decreased risk for GSD (95% confidence interval [95% CI]: 0.68–1.05; P = 0.31; I2 = 13%), and comparison of alleles ε4 with ε3 yielded a 25% increased risk (95% confidence interval [95% CI]: 0.97–1.61; P = 0.0003; I2 = 63%). Subgroup analysis by study design indicated that the magnitude of association in hospital-based studies was largely significantly strengthened for ε4 allelic model (odds ratio [OR] = 1.46; 95% CI: 1.05–2.02; p = 0.0007; I2 = 65%). Subgroup analysis by age of controls indicated a remarkably significant elevation in the magnitude of association in age >50 subgroups in ε4 allelic model (OR = 1.50; 95% CI: 1.03–2.19; p = 0.0009; I2 = 72%). Moreover, subgroup analysis by cases gender indicated a reduction in the magnitude of association in male<30% studies for E2/2 genotypic model (OR = 0.32; 95% CI: 0.07–1.49; p = 0.16; I2 = 45%). Conclusions Our results reveal that Apo E gene ε4 allele is a risk factor of gallbladder stone disease, especially in elder people and Chinese population.
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Murray-Taylor FM, Ho YY, Densupsoontorn N, Chang CL, Deckelbaum RJ, Seo T. n-3, but not n-6 lipid particle uptake requires cell surface anchoring. Biochem Biophys Res Commun 2010; 392:135-9. [PMID: 20056109 DOI: 10.1016/j.bbrc.2009.12.164] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2009] [Accepted: 12/31/2009] [Indexed: 10/20/2022]
Abstract
Omega-3 (n-3) fatty acids are emerging as bioactive agents protective against cardiovascular disease. However, their cellular delivery pathways are poorly defined. Here we questioned whether the uptake of n-3 triglyceride-rich particles (TGRP) is mediated by cell surface proteoglycans (PG) using LDL receptor (LDLR)+/+ and LDLR-/- cell models. LDLR+/+ but not LDLR-/- cells showed higher n-6 over n-3 TGRP uptake. Removal of cell surface proteins and receptors by pronase markedly enhanced the uptake of n-3 but not n-6 TGRP. Lactoferrin blockage of apoE-mediated pathways decreased the uptake of n-6 TGRP by up to 85% (p<0.05) but had insignificant effect on n-3 TGRP uptake. PG removal by sodium chlorate in LDLR+/+ cells substantially reduced n-3 TGRP uptake but had little effect on n-6 TGRP uptake. Thus, while n-6 TGRP uptake is preferentially mediated by LDLR-dependent pathways, the uptake of n-3 TGRP depends more on PG and non-LDLR cell surface anchoring.
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Affiliation(s)
- Faith M Murray-Taylor
- Institute of Human Nutrition, College of Physicians and Surgeons, Columbia University, USA
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12
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Kockx M, Guo DL, Traini M, Gaus K, Kay J, Wimmer-Kleikamp S, Rentero C, Burnett JR, Le Goff W, Van Eck M, Stow JL, Jessup W, Kritharides L. Cyclosporin A decreases apolipoprotein E secretion from human macrophages via a protein phosphatase 2B-dependent and ATP-binding cassette transporter A1 (ABCA1)-independent pathway. J Biol Chem 2009; 284:24144-54. [PMID: 19589783 DOI: 10.1074/jbc.m109.032615] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cyclosporin A (CsA) is an immunosuppressant that inhibits protein phosphatase 2B (PP2B/calcineurin) and is associated with hyperlipidemia, decreased cholesterol efflux via ATP-binding cassette transporter A1 (ABCA1), and increased risk of atherosclerosis. Apolipoprotein E (apoE) is an important regulator of lipid metabolism and atherosclerosis, the secretion of which from human macrophages is regulated by the serine/threonine protein kinase A (PKA) and intracellular calcium (Ca(2+)) (Kockx, M., Guo, D. L., Huby, T., Lesnik, P., Kay, J., Sabaretnam, T., Jary, E., Hill, M., Gaus, K., Chapman, J., Stow, J. L., Jessup, W., and Kritharides, L. (2007) Circ. Res. 101, 607-616). As PP2B is Ca(2+)-dependent and has been linked to PKA-dependent processes, we investigated whether CsA modulated apoE secretion. CsA dose- and time-dependently inhibited secretion of apoE from primary human macrophages and from Chinese hamster ovary cells stably transfected with human apoE and increased cellular apoE levels without affecting apoE mRNA. [(35)S]Met kinetic modeling studies showed that CsA inhibited both secretion and degradation of apoE, increasing the half-life of cellular apoE 2-fold. CsA also inhibited secretion from primary human Tangier disease macrophages and from mouse macrophages deficient in ABCA1, indicating that the effect is independent of the known inhibition of ABCA1 by CsA. The role of PP2B in mediating apoE secretion was confirmed using additional peptide and chemical inhibitors of PP2B. Importantly, kinetic modeling, live-cell imaging, and confocal microscopy all indicated that CsA inhibited apoE secretion by mechanisms quite distinct from those of PKA inhibition, most likely inducing accumulation of apoE in the endoplasmic reticulum compartment. Taken together, these results establish a novel mechanism for the pro-atherosclerotic effects of CsA, and establish for the first time a role for PP2B in regulating the intracellular transport and secretion of apoE.
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Affiliation(s)
- Maaike Kockx
- Centre for Vascular Research, School of Medical Sciences, University of New South Wales, Sydney, New South Wales 2052, Australia
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Carmel JF, Tarnus E, Cohn JS, Bourdon E, Davignon J, Bernier L. High expression of apolipoprotein E impairs lipid storage and promotes cell proliferation in human adipocytes. J Cell Biochem 2009; 106:608-17. [PMID: 19130493 DOI: 10.1002/jcb.22037] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Apolipoprotein E (apoE), a key regulator of lipid metabolism, is highly produced by adipose tissue and adipocytes. However, there is little information about its role on adipocyte functions. Because apoE-deficiency in adipocytes was shown to impair adipocyte differentiation, we investigated the consequences of apoE high expression on differentiation and proliferation of a human adipocytic cell line (SW872). SW872 cells were transfected with human apoE to induce a fivefold increase in apoE production and secretion. Adipocyte differentiation and proliferation were assayed by measuring lipid content, adipogenic gene expression, cell number, cell resistance to serum deprivation, and cell division kinetics. Cultured apoE-transfected cells accumulated less triglycerides and less cholesterol than control cells. This decrease in lipid accumulation was associated with a strong downregulation of peroxisome proliferator-activated receptors gamma1 and gamma2 and stearoyl-CoA desaturase 1. The decrease in lipid accumulation was not dependent on the presence of lipids, lipoproteins, or PPAR-gamma agonists in the culture medium, nor was it observed with exogenously added apoE. Moreover, we observed that apoE-transfected cells were more resistant to death induced by serum deprivation, and that these cells underwent more cell divisions than control cells. These results bring new evidence of apoE-involvement in metabolic disorders at the adipocyte level.
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Affiliation(s)
- Jean-François Carmel
- Hyperlipidemia and Atherosclerosis Research Group, Clinical Research Institute of Montreal, Montreal, Quebec, Canada
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Kosacka J, Gericke M, Nowicki M, Kacza J, Borlak J, Spanel-Borowski K. Apolipoproteins D and E3 exert neurotrophic and synaptogenic effects in dorsal root ganglion cell cultures. Neuroscience 2009; 162:282-91. [PMID: 19414061 DOI: 10.1016/j.neuroscience.2009.04.073] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2009] [Revised: 04/27/2009] [Accepted: 04/29/2009] [Indexed: 11/17/2022]
Abstract
Co-cultures of 3T3-L1 adipocytes with neurons from the rat dorsal root ganglia (DRG) showed enhanced neuritogenesis and synaptogenesis. Microarray analysis for upregulated genes in adipocyte/DRG co-cultures currently points to apolipoproteins D and E (ApoD, ApoE) as influential proteins. We therefore tested adipocyte-secreted cholesterol and the carrier proteins ApoD and ApoE3. Cholesterol, ApoD, and ApoE3 each increased neurite outgrowth and upregulated the expression of presynaptic synaptophysin and synaptotagmin, as well as the postsynaptic density protein 95. The neurotrophic effects of ApoD and ApoE3 were associated with an increased expression of the low-density lipoprotein receptor and apolipoprotein E receptor 2. Simultaneous treatment with receptor-associated protein, an apolipoprotein receptor antagonist, inhibited the neurotrophic function of both apolipoproteins. The application of ApoD, ApoE3, and cholesterol to DRG cell cultures corresponded with increased expression of the chemokine stromal cell-derived factor 1 and its receptor CXC chemokine receptor 4 (CXCR4). Surprisingly, the inhibition of CXCR4 by the antagonistic drug AMD3100 decreased the apolipoprotein/cholesterol dependent neurotrophic effects. We thus assume that apolipoprotein-induced neuritogenesis in DRG cells interferes with CXCR4 signaling, and that adipocyte-derived apolipoproteins might be helpful in nerve repair.
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Affiliation(s)
- J Kosacka
- Institute of Anatomy, University of Leipzig, Liebigstrabetae 13, D-04103 Leipzig, Germany.
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Kockx M, Jessup W, Kritharides L. Regulation of endogenous apolipoprotein E secretion by macrophages. Arterioscler Thromb Vasc Biol 2008; 28:1060-7. [PMID: 18388328 DOI: 10.1161/atvbaha.108.164350] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Apolipoprotein E has critical roles in the protection against atherosclerosis and is understood to follow the classical constitutive secretion pathway. Recent studies have indicated that the secretion of apoE from macrophages is a regulated process of unexpected complexity. Cholesterol acceptors such as apolipoprotein A-I, high density lipoprotein, and phospholipid vesicles can stimulate apoE secretion. The ATP binding cassette transporter ABCA1 is involved in basal apoE secretion and in lipidating apoE-containing particles secreted by macrophages. However, the stimulation of apoE secretion by apoA-I is ABCA1-independent, indicating the existence of both ABCA1-dependent and -independent pathways of apoE secretion. The release of apoE under basal conditions is also regulated, requiring intact protein kinase A activity, intracellular calcium, and an intact microtubular network. Mathematical modeling of apoE turnover indicates that whereas some pools of apoE are committed to either secretion or degradation, other pools can be diverted from degradation toward secretion. Targeted inhibition or stimulation of specific apoE trafficking pathways will provide unique opportunities to regulate the biology of this important molecule.
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Affiliation(s)
- Maaike Kockx
- Macrophage Biology Group, Centre for Vascular Research, Room 405C Wallace Wurth Building, University of New South Wales, High Street, Kensington, Sydney, NSW 2050, Australia
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Densupsoontorn N, Worgall TS, Seo T, Hamai H, Deckelbaum RJ. Fatty acid supplied as triglyceride regulates SRE-mediated gene expression as efficiently as free fatty acids. Lipids 2007; 42:885-91. [PMID: 17680293 DOI: 10.1007/s11745-007-3093-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2006] [Accepted: 06/26/2007] [Indexed: 01/21/2023]
Abstract
Sterol regulatory element binding proteins (SREBPs) are key transcription proteins that bind to sterol regulatory elements (SRE) of genes essential for cellular cholesterol and fatty acid homeostasis. Polyunsaturated fatty acids (PUFA) strongly inhibit SREBP processing at post-transcriptional levels. We questioned if delivering PUFA as part of a triglyceride (TG) molecule would have similar effects and efficiency as free non-esterified PUFA. CHO cells stably transfected with an SRE-promoter linked to the luciferase reporter gene were incubated for 8-24 h with linoleic acid (LA) complexed to BSA (molar ratios 0.5-4:1), VLDL-sized trilinolein emulsions (TL, 25-200 microg/ml), and chylomicron-sized soy oil emulsions in the presence and absence of apoE. Effects of LA and TL on decreasing SRE-luciferase activity were similar and dose and time dependent. Both TL and LA significantly and rapidly (<or=2-12 h) reduced SRE-mediated gene expression by up to 75%. At equal fatty acid concentrations, SRE inhibition by TL was as effective as LA. ApoE addition increased inhibition by TL. Inhibition of gene expression was highly correlated to cell TG accumulation. We conclude that TG like fatty acids are rapid and efficient modulators of SRE-mediated gene expression.
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Affiliation(s)
- Narumon Densupsoontorn
- Institute of Human Nutrition and Department of Pediatrics, College of Physicians and Surgeons, Columbia University, 630 W. 168th St., PH1512, New York, NY 10032, USA
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Kockx M, Guo DL, Huby T, Lesnik P, Kay J, Sabaretnam T, Jary E, Hill M, Gaus K, Chapman J, Stow JL, Jessup W, Kritharides L. Secretion of apolipoprotein E from macrophages occurs via a protein kinase A and calcium-dependent pathway along the microtubule network. Circ Res 2007; 101:607-16. [PMID: 17660382 DOI: 10.1161/circresaha.107.157198] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Macrophage-specific expression of apolipoprotein (apo)E protects against atherosclerosis; however, the signaling and trafficking pathways regulating secretion of apoE are unknown. We investigated the roles of the actin skeleton, microtubules, protein kinase A (PKA) and calcium (Ca2+) in regulating apoE secretion from macrophages. Disrupting microtubules with vinblastine or colchicine inhibited basal secretion of apoE substantially, whereas disruption of the actin skeleton had no effect. Structurally distinct inhibitors of PKA (H89, KT5720, inhibitory peptide PKI(14-22)) all decreased basal secretion of apoE by between 50% to 80% (P<0.01). Pulse-chase experiments demonstrated that inhibition of PKA reduced the rate of apoE secretion without affecting its degradation. Confocal microscopy and live cell imaging of apoE-green fluorescent protein-transfected RAW macrophages identified apoE-green fluorescent protein in vesicles colocalized with the microtubular network, and inhibition of PKA markedly inhibited vesicular movement. Chelation of intracellular calcium ([Ca2+]i) with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetate-acetoxymethyl ester (BAPTA-AM) inhibited apoE secretion by 77.2% (P<0.01). Injection of c57Bl6 apoE+/+ bone marrow-derived macrophages into the peritoneum of apoE-/- C57Bl6 mice resulted in time-dependent secretion of apoE into plasma, which was significantly inhibited by transient exposure of macrophages to BAPTA-AM and colchicine and less effectively inhibited by H89. We conclude that macrophage secretion of apoE occurs via a PKA- and calcium-dependent pathway along the microtubule network.
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Affiliation(s)
- Maaike Kockx
- Macrophage Biology Group, Centre for Vascular Research, School of Medical Sciences, University of New South Wales, Australia
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Chan WM, Ho YY. Inhibition of cell proliferation by apolipoprotein E isoform expression. Arch Biochem Biophys 2006; 451:97-102. [PMID: 16780788 DOI: 10.1016/j.abb.2006.05.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2006] [Revised: 05/06/2006] [Accepted: 05/08/2006] [Indexed: 10/24/2022]
Abstract
The anti-atherogenic effects of human apolipoprotein E3 (apoE3) have been partially attributed to its anti-proliferation properties. We studied if endogenously expressed apoE elicits isoform-dependent effects on cell proliferation. Rat F111 fibroblasts without native expression of apoE were used to establish cell lines with stable expression of the three human apoE isoforms. Cell growth curve studies showed that expression of apoE isoforms prolonged cell population doubling time in an isoform-dependent manner with apoE3 showing the most potent effect followed by apoE2 and apoE4 exhibiting comparable effects. Interestingly, saturation density of cell population was significantly reduced by the expression of apoE4 isofom. Further analyses revealed that all three apoE isoforms significantly lengthened G0/G1 phase (p < 0.05) of the cell cycle and were associated with the suppression of ERK1/2 activities. However, these changes were not sufficient to explain the isoform-dependent effects of apoE expression on cell population doubling time and saturation density.
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Affiliation(s)
- Wing-Man Chan
- Department of Biochemistry, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China
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McGarvey TW, Nguyen TB, Malkowicz SB. An interaction between apolipoprotein E and TERE1 with a possible association with bladder tumor formation. J Cell Biochem 2005; 95:419-28. [PMID: 15782423 DOI: 10.1002/jcb.20432] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
TERE1, a recently discovered gene/protein appears to play a role in bladder tumor growth regulation but to date does not have clear functional correlates. The objective of this study was to gain further insight into the function of the TERE1 protein by identifying potential protein to protein interactions with TERE1 and determining whether these interactions are associated with putative growth regulatory pathways and/or bladder tumor formation. Towards this aim, we have performed a bacterial two hybrid assay and isolated interacting clones, which then were sequenced and further examined by affinity chromatography and immunoprecipitation. From among several positive clones, we isolated a putative interacting plasmid containing the C-terminal portion of preapolipoprotein E starting from amino acid number 124 from the pBT-TERE1/pTarget-cDNA bacterial two hybrid system. The C-terminal portion of apoE interaction with the TERE1 was confirmed using ProBond columns by the expression of 6XHis recombinant and (35)S methionine/cysteine labeled proteins. We found that there was ubiquitous expression of the apoE transcript in normal bladder and in various grades and stages of transitional cell carcinoma (TCC) of the bladder. Likewise, we detected the apoE protein in both normal and malignant bladder tissues by Western blot. There was a significant decrease in the apoE protein in 12 of 16 muscle invasive TCCs of the bladder compared to normal bladder mucosa samples. Previous studies in rat fibroblasts have found that expression of apoE can decrease the phosphorylation of the growth factor-related p42/44 MAP kinase. A significant decrease in p44/p42 MAPK phophorylation was also apparent using a phosphorylation specific antibody in human 293 kidney cells upon transfection and expression of apoE. In conclusion, the results from this study suggest that the expression and regulation of the apoE pathway may yield clues toward understanding the function of TERE1.
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Affiliation(s)
- Terence W McGarvey
- Division of Urology, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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Ton MN, Chang C, Carpentier YA, Deckelbaum RJ. In vivo and in vitro properties of an intravenous lipid emulsion containing only medium chain and fish oil triglycerides. Clin Nutr 2005; 24:492-501. [PMID: 16054521 DOI: 10.1016/j.clnu.2005.03.001] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2004] [Accepted: 03/03/2005] [Indexed: 11/26/2022]
Abstract
BACKGROUND & AIMS The triglyceride (TG) fatty acyl composition in lipid emulsions influences their metabolism. Little is known about the effects of long chain omega-3 polyunsaturated fatty acids (PUFA) on lipid emulsion metabolism. We investigated possible differences between omega-3 containing emulsions in their metabolism and tissue-targeting in vivo in a mouse model, and in vitro using lipolysis and cell culture experiments. METHODS Soy oil (LCT), MCT/LCT/omega-3 (5:4:1, wt/wt/wt), and MCT/omega-3 (8:2, wt/wt) emulsions were radiolabeled with nondegradable 1alpha,2alpha (n)-[3H] cholesteryl oleoyl ether to trace core particle metabolism in C57BL/6J mice following a bolus injection. Blood samples obtained over 25 min and extracted organs were used to measure the tissue distribution of lipid emulsion particles. Lipoprotein lipase (LpL)-mediated hydrolysis experiments and cell uptake studies in cultured J774 murine macrophages were also performed. RESULTS Blood clearance of 8:2 was 13.4% and 29.8% faster compared to 5:4:1 and LCT, respectively. LCT had greatest liver uptake. LpL-mediated hydrolysis was greatest in 8:2 and lowest in LCT. Overall, cell TG accumulation in the presence of apolipoprotein E was least with 8:2. CONCLUSIONS Our data shows that 8:2 had the most efficient blood clearance but less hepatic uptake in vivo. In vitro, 8:2 had both highest hydrolysis by LpL and intracellular TG utilization in the presence of apoE. Thus, an 8:2 lipid emulsion undergoes efficient blood clearance and may direct omega-3 PUFA more towards extrahepatic tissues.
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Affiliation(s)
- Mimi N Ton
- Division of Gastroenterology, Hepatology, & Nutrition, Department of Pediatrics, Columbia University Medical Center, New York, NY, USA
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Dove DE, Linton MF, Fazio S. ApoE-mediated cholesterol efflux from macrophages: separation of autocrine and paracrine effects. Am J Physiol Cell Physiol 2004; 288:C586-92. [PMID: 15509658 DOI: 10.1152/ajpcell.00210.2004] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Macrophages in the vessel wall secrete high levels of apolipoprotein E (apoE). Cholesterol efflux from macrophages to apoE has been shown to decrease foam cell formation and prevent atherosclerosis. An apoE molecule can mediate cholesterol efflux from the macrophage that originally secreted it (autocrine effect) or from surrounding macrophages (paracrine effect). Traditional methodologies have not been able to separate these serial effects. The novel methodology presented here was developed to separate autocrine and paracrine effects by using a simple mathematical model to interpret the effects of dilution on apoE-mediated cholesterol efflux. Our results show that, at very dilute concentrations, the paracrine effect of apoE is not evident and the autocrine effect becomes the dominant mediator of efflux. However, at saturating concentrations, paracrine apoE causes 80-90% of the apoE-mediated cholesterol efflux, whereas autocrine apoE is responsible for the remaining 10-20%. These results suggest that the relative importance of autocrine and paracrine apoE depends on the size of the local distribution volume, a factor not considered in previous in vitro studies of apoE function. Furthermore, autocrine effects of apoE could be critical in the prevention of foam cell formation in vivo. This novel methodology may be applicable to other types of mixed autocrine/paracrine systems, such as signal transduction systems.
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Affiliation(s)
- Dwayne E Dove
- Department of Pathology, Vanderbilt University Medical Center, 383 Preston Research Bldg., Nashville, TN 37232-6300, USA
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Gingis-Velitski S, Zetser A, Kaplan V, Ben-Zaken O, Cohen E, Levy-Adam F, Bashenko Y, Flugelman MY, Vlodavsky I, Ilan N. Heparanase uptake is mediated by cell membrane heparan sulfate proteoglycans. J Biol Chem 2004; 279:44084-92. [PMID: 15292202 DOI: 10.1074/jbc.m402131200] [Citation(s) in RCA: 135] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Heparanase is a mammalian endoglycosidase that degrades heparan sulfate (HS) at specific intrachain sites, an activity that is strongly implicated in cell dissemination associated with metastasis and inflammation. In addition to its structural role in extracellular matrix assembly and integrity, HS sequesters a multitude of polypeptides that reside in the extracellular matrix as a reservoir. A variety of growth factors, cytokines, chemokines, and enzymes can be released by heparanase activity and profoundly affect cell and tissue function. Thus, heparanase bioavailability, accessibility, and activity should be kept tightly regulated. We provide evidence that HS is not only a substrate for, but also a regulator of, heparanase. Addition of heparin or xylosides to cell cultures resulted in a pronounced accumulation of, heparanase in the culture medium, whereas sodium chlorate had no such effect. Moreover, cellular uptake of heparanase was markedly reduced in HS-deficient CHO-745 mutant cells, heparan sulfate proteoglycan-deficient HT-29 colon cancer cells, and heparinase-treated cells. We also studied the heparanase biosynthetic route and found that the half-life of the active enzyme is approximately 30 h. This and previous localization studies suggest that heparanase resides in the endosomal/lysosomal compartment for a relatively long period of time and is likely to play a role in the normal turnover of HS. Co-localization studies and cell fractionation following heparanase addition have identified syndecan family members as candidate molecules responsible for heparanase uptake, providing an efficient mechanism that limits extracellular accumulation and function of heparanase.
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Affiliation(s)
- Svetlana Gingis-Velitski
- Cancer and Vascular Biology Research Center, Bruce Rappaport Faculty of Medicine, Technion, Haifa 31096, Israel
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Mullick AE, Deckelbaum RJ, Goldberg IJ, Al-Haideri M, Rutledge JC. Apolipoprotein E and lipoprotein lipase increase triglyceride-rich particle binding but decrease particle penetration in arterial wall. Arterioscler Thromb Vasc Biol 2002; 22:2080-5. [PMID: 12482838 DOI: 10.1161/01.atv.0000040221.70377.19] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Liver-derived apolipoprotein E (apoE) decreases atherosclerosis without altering the circulating concentrations of plasma lipoproteins. We evaluated the effects of apoE and lipoprotein lipase (LpL) on the interactions of triglyceride-rich particles (TGRPs) in the arterial wall. METHODS AND RESULTS Quantitative fluorescence microscopy was used to study the interactions of TGRPs (25- to 35-nm diameter) in the arterial wall. Carotid arteries were harvested from rats, placed in a perfusion chamber, and perfused with fluorescently labeled TGRPs. In the absence of apoE or LpL, 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine-TGRP (100 microg neutral lipid/mL) was poorly retained in the arterial wall. The addition of either apoE (10 microg/mL) or LpL (10 microg/mL) increased TGRP accumulation 220% and 100%, respectively. This effect was attenuated by heparin (10.0 IU/mL). Histological analyses of cross sections from these vessels demonstrate that in the absence of apoE or LpL, there is deep penetration of lipid into the arterial wall. With the addition of either apoE or LpL, arterial wall penetration of TGRP is blocked. CONCLUSIONS These results demonstrate that although apoE and LpL increase arterial wall accumulation of TGRPs, these proteins also reduce the penetration of TGRPs into the arterial wall. We postulate that this may represent a novel antiatherogenic property of apoE and LpL.
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Affiliation(s)
- Adam E Mullick
- Division of Endocrinology, University of California, Davis 95616, USA.
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Ho YY, Deckelbaum RJ, Chen Y, Vogel T, Talmage DA. Apolipoprotein E inhibits serum-stimulated cell proliferation and enhances serum-independent cell proliferation. J Biol Chem 2001; 276:43455-62. [PMID: 11551921 DOI: 10.1074/jbc.m105325200] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Independently of its role in lipid homeostasis, apolipoprotein E (apoE) inhibits cell proliferation. We compared the effects of apoE added to media (exogenous apoE) with the effects of stably expressed apoE (endogenous apoE) on cell proliferation. Exogenous and endogenous apoE increased population doubling times by 30-50% over a period of 14 days by prolonging the G(1) phase of the cell cycle. Exogenous and endogenous apoE also decreased serum-stimulated DNA synthesis by 30-50%. However, apoE did not cause cell cycle arrest; both apoE-treated and control cells achieved equivalent saturation densities at 14 days. Further analyses demonstrated that exogenous and endogenous apoE prevented activation of MAPK but not induction of c-fos expression in response to serum growth factors. Endogenous (but not exogenous) apoE altered serum concentration-dependent effects on proliferation. Whereas control (non-apoE-expressing) cell numbers increased with increasing serum concentrations (1.6-fold for every 2-fold increase in serum), apoE-expressing cell numbers did not differ as serum levels were raised from 2.5 to 10%. In addition, in low serum (0.1%), apoE-expressing cells had elevated DNA synthesis levels compared with control cells. We conclude that apoE does not simply inhibit cell proliferation; rather, the presence of apoE alters the response to and requirement for serum mitogens.
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Affiliation(s)
- Y Y Ho
- Institute of Human Nutrition and the Department of Pediatrics, Columbia University, New York, New York 10032, USA
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Burgess JW, Marcel YL. Dynamic and stable pools of apoE differ functionally at the HepG2 cell surface. J Lipid Res 2001. [DOI: 10.1016/s0022-2275(20)30273-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Lin CY, Huang ZH, Mazzone T. Interaction with proteoglycans enhances the sterol efflux produced by endogenous expression of macrophage apoE. J Lipid Res 2001. [DOI: 10.1016/s0022-2275(20)31603-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Abstract
Over the past 10 years, many advances have been made in our understanding of the intravascular metabolism of triglyceride-rich lipoproteins. It is now known that the complex extracellular interactions of triglyceride-rich lipoprotein-associated apolipoprotein E, lipoprotein lipase and hepatic lipase with heparan sulfate proteoglycans and lipoprotein receptors facilitate the hepatocellular uptake of triglyceride-rich lipoproteins. Recent studies have also revealed that the intracellular fate of internalized triglyceride-rich lipoproteins is highly complex. The dissociation of triglyceride-rich lipoprotein components within intracellular endosomal compartments involves the recycling of apolipoprotein E, whereas the remaining lipid core associated with apolipoprotein B is susceptible to lysosomal degradation. Apolipoprotein E recycling is an important newly discovered feature of lipoprotein metabolism, and will be discussed in the context of its intracellular transport mechanisms and cholesterol efflux. Current concepts concerning its potential relevance with regard to lipoprotein metabolism and atherosclerosis will also be discussed.
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Affiliation(s)
- J Heeren
- Department of Internal Medicine, University Hospital Hamburg-Eppendorf, Hamburg, Germany.
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