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Bhale AS, Meilhac O, d'Hellencourt CL, Vijayalakshmi MA, Venkataraman K. Cholesterol transport and beyond: Illuminating the versatile functions of HDL apolipoproteins through structural insights and functional implications. Biofactors 2024. [PMID: 38661230 DOI: 10.1002/biof.2057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Accepted: 04/02/2024] [Indexed: 04/26/2024]
Abstract
High-density lipoproteins (HDLs) play a vital role in lipid metabolism and cardiovascular health, as they are intricately involved in cholesterol transport and inflammation modulation. The proteome of HDL particles is indeed complex and distinct from other components in the bloodstream. Proteomics studies have identified nearly 285 different proteins associated with HDL; however, this review focuses more on the 15 or so traditionally named "apo" lipoproteins. Important lipid metabolizing enzymes closely working with the apolipoproteins are also discussed. Apolipoproteins stand out for their integral role in HDL stability, structure, function, and metabolism. The unique structure and functions of each apolipoprotein influence important processes such as inflammation regulation and lipid metabolism. These interactions also shape the stability and performance of HDL particles. HDLs apolipoproteins have multifaceted roles beyond cardiovascular diseases (CVDs) and are involved in various physiological processes and disease states. Therefore, a detailed exploration of these apolipoproteins can offer valuable insights into potential diagnostic markers and therapeutic targets. This comprehensive review article aims to provide an in-depth understanding of HDL apolipoproteins, highlighting their distinct structures, functions, and contributions to various physiological processes. Exploiting this knowledge holds great potential for improving HDL function, enhancing cholesterol efflux, and modulating inflammatory processes, ultimately benefiting individuals by limiting the risks associated with CVDs and other inflammation-based pathologies. Understanding the nature of all 15 apolipoproteins expands our knowledge of HDL metabolism, sheds light on their pathological implications, and paves the way for advancements in the diagnosis, prevention, and treatment of lipid and inflammatory-related disorders.
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Affiliation(s)
- Aishwarya Sudam Bhale
- Centre for Bio-Separation Technology, Vellore Institute of Technology, Vellore, Tamil Nadu, India
| | - Olivier Meilhac
- Inserm, UMR 1188 Diabète Athérothrombose Thérapies Réunion Océan Indien (DéTROI), Université de La Réunion, Saint-Pierre, France
| | - Christian Lefebvre d'Hellencourt
- Inserm, UMR 1188 Diabète Athérothrombose Thérapies Réunion Océan Indien (DéTROI), Université de La Réunion, Saint-Pierre, France
| | | | - Krishnan Venkataraman
- Centre for Bio-Separation Technology, Vellore Institute of Technology, Vellore, Tamil Nadu, India
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Chen YQ, Yang Y, Zhen EY, Beyer TP, Li H, Wen Y, Ehsani M, Jackson N, Xie K, Jung H, Scheithauer JL, Kumari A, Birrane G, Russell AM, Balasubramaniam D, Liao Z, Siegel RW, Qian Y, Ploug M, Young SG, Konrad RJ. Carboxyl-terminal sequences in APOA5 are important for suppressing ANGPTL3/8 activity. Proc Natl Acad Sci U S A 2024; 121:e2322332121. [PMID: 38625948 PMCID: PMC11046700 DOI: 10.1073/pnas.2322332121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2023] [Accepted: 03/16/2024] [Indexed: 04/18/2024] Open
Abstract
Apolipoprotein AV (APOA5) lowers plasma triglyceride (TG) levels by binding to the angiopoietin-like protein 3/8 complex (ANGPTL3/8) and suppressing its capacity to inhibit lipoprotein lipase (LPL) catalytic activity and its ability to detach LPL from binding sites within capillaries. However, the sequences in APOA5 that are required for suppressing ANGPTL3/8 activity have never been defined. A clue to the identity of those sequences was the presence of severe hypertriglyceridemia in two patients harboring an APOA5 mutation that truncates APOA5 by 35 residues ("APOA5Δ35"). We found that wild-type (WT) human APOA5, but not APOA5Δ35, suppressed ANGPTL3/8's ability to inhibit LPL catalytic activity. To pursue that finding, we prepared a mutant mouse APOA5 protein lacking 40 C-terminal amino acids ("APOA5Δ40"). Mouse WT-APOA5, but not APOA5Δ40, suppressed ANGPTL3/8's capacity to inhibit LPL catalytic activity and sharply reduced plasma TG levels in mice. WT-APOA5, but not APOA5Δ40, increased intracapillary LPL levels and reduced plasma TG levels in Apoa5-/- mice (where TG levels are high and intravascular LPL levels are low). Also, WT-APOA5, but not APOA5Δ40, blocked the ability of ANGPTL3/8 to detach LPL from cultured cells. Finally, an antibody against a synthetic peptide corresponding to the last 26 amino acids of mouse APOA5 reduced intracapillary LPL levels and increased plasma TG levels in WT mice. We conclude that C-terminal sequences in APOA5 are crucial for suppressing ANGPTL3/8 activity in vitro and for regulating intracapillary LPL levels and plasma TG levels in vivo.
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Affiliation(s)
- Yan Q. Chen
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN462585
| | - Ye Yang
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA90095
- Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, CA90095
| | - Eugene Y. Zhen
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN462585
| | - Thomas P. Beyer
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN462585
| | - Hongxia Li
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN462585
| | - Yi Wen
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN462585
| | - Mariam Ehsani
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN462585
| | - Nicholas Jackson
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA90095
| | - Katherine Xie
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA90095
| | - Hyesoo Jung
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA90095
| | - Julia L. Scheithauer
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA90095
| | - Anni Kumari
- Finsen Laboratory, Centre for Cancer and Organ Diseases, Copenhagen University Hospital-Rigshospitalet, DK-2200Copenhagen N, Denmark
- Finsen Laboratory, Biotech Research and Innovation Centre, University of Copenhagen, DK-2200Copenhagen N, Denmark
| | - Gabriel Birrane
- Division of Experimental Medicine, Beth Israel Deaconess Medical Center, Boston, MA02215
| | - Anna M. Russell
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN462585
| | | | - Zhongping Liao
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN462585
| | - Robert W. Siegel
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN462585
| | - Yuewei Qian
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN462585
| | - Michael Ploug
- Finsen Laboratory, Centre for Cancer and Organ Diseases, Copenhagen University Hospital-Rigshospitalet, DK-2200Copenhagen N, Denmark
- Finsen Laboratory, Biotech Research and Innovation Centre, University of Copenhagen, DK-2200Copenhagen N, Denmark
| | - Stephen G. Young
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA90095
- Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, CA90095
| | - Robert J. Konrad
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN462585
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Perera SD, Hegele RA. Genetic variation in apolipoprotein A-V in hypertriglyceridemia. Curr Opin Lipidol 2024; 35:66-77. [PMID: 38117614 PMCID: PMC10919278 DOI: 10.1097/mol.0000000000000916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2023]
Abstract
PURPOSE OF REVIEW While biallelic rare APOA5 pathogenic loss-of-function (LOF) variants cause familial chylomicronemia syndrome, heterozygosity for such variants is associated with highly variable triglyceride phenotypes ranging from normal to severe hypertriglyceridemia, often in the same individual at different time points. Here we provide an updated overview of rare APOA5 variants in hypertriglyceridemia. RECENT FINDINGS Currently, most variants in APOA5 that are considered to be pathogenic according to guidelines of the American College of Medical Genetics and Genomics are those resulting in premature termination codons. There are minimal high quality functional data on the impact of most rare APOA5 missense variants; many are considered as variants of unknown or uncertain significance. Furthermore, particular common polymorphisms of APOA5 , such as p.Ser19Trp and p.Gly185Cys in Caucasian and Asian populations, respectively, are statistically overrepresented in hypertriglyceridemia cohorts and are sometimes misattributed as being causal for chylomicronemia, when they are merely risk alleles for hypertriglyceridemia. SUMMARY Both biallelic and monoallelic LOF variants in APOA5 are associated with severe hypertriglyceridemia, although the biochemical phenotype in the monoallelic state is highly variable and is often exacerbated by secondary factors. Currently, with few exceptions, the principal definitive mechanism for APOA5 pathogenicity is through premature truncation. The pathogenic mechanisms of most missense variants in APOA5 remain unclear and require additional functional experiments or family studies.
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Affiliation(s)
- Shehan D Perera
- Departments of Biochemistry and Medicine, Schulich School of Medicine and Dentistry, Western University, 1151 Richmond Street North, London, Ontario, Canada
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Liu Y, Dai S, Qin S, Zhou J, Wang Z, Yin G. The pathogenic mutations of APOA5 in Chinese patients with hyperlipidemic acute pancreatitis. Lipids Health Dis 2024; 23:44. [PMID: 38331899 PMCID: PMC10851583 DOI: 10.1186/s12944-024-02011-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 01/09/2024] [Indexed: 02/10/2024] Open
Abstract
BACKGROUND AND AIMS To study the role of gene mutations in the development of severe hypertriglyceridemia (HTG) in patients with hyperlipidemic acute pancreatitis (HLAP), especially different apolipoprotein A5 (APOA5) mutations. METHODS Whole-exome sequencing was performed on 163 patients with HLAP and 30 patients with biliary acute pancreatitis (BAP). The pathogenicity of mutations was then assessed by combining clinical information, predictions of bioinformatics programs, information from multiple gene databases, and residue location and conservation. The pathogenic mutations of APOA5 were visualized using the software. RESULTS 1. Compared with BAP patients, pathogenic mutations of APOA5 were frequent in HLAP patients; among them, the heterozygous mutation of p.G185C was the most common. 2. All six pathogenic mutations of APOA5 identified in this study (p.S35N, p.D167V, p.G185C, p.K188I, p.R223C, and p.H182fs) were positively correlated with severe HTG; they were all in the important domains of apolipoprotein A-V (apoA-V). Residue 223 is strictly conserved in multiple mammals and is located in the lipoprotein lipase (LPL)-binding domain (Pro215-Phe261). When Arg 223 is mutated to Cys 223, the positive charge of this residue is reduced, which is potentially destructive to the binding function of apoA-V to LPL. 3. Four new APOA5 mutations were identified, namely c.563A > T, c.667C > T, c.788G > A, and c.544_545 insGGTGC. CONCLUSIONS The pathogenic mutations of APOA5 were specific to the patients with HLAP and severe HTG in China, and identifying such mutations had clinical significance in elucidating the etiology and subsequent treatment.
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Affiliation(s)
- Yuxin Liu
- Department of Gastroenterology, The Second Affiliated Hospital of Soochow University, District, No.1055, San-Xiang Road, Gu-Su, Suzhou, 215000, Jiangsu Province, China
| | - Si Dai
- Department of Gastroenterology, Songtao Miao Autonomous County People's Hospital, Tongren, 554199, Guizhou Province, China
| | - Shuqi Qin
- Department of Gastroenterology, The Second Affiliated Hospital of Soochow University, District, No.1055, San-Xiang Road, Gu-Su, Suzhou, 215000, Jiangsu Province, China
| | - Jing Zhou
- Department of Gastroenterology, The Second Affiliated Hospital of Soochow University, District, No.1055, San-Xiang Road, Gu-Su, Suzhou, 215000, Jiangsu Province, China
| | - Zhendan Wang
- Department of Gastroenterology, The Second Affiliated Hospital of Soochow University, District, No.1055, San-Xiang Road, Gu-Su, Suzhou, 215000, Jiangsu Province, China
| | - Guojian Yin
- Department of Gastroenterology, The Second Affiliated Hospital of Soochow University, District, No.1055, San-Xiang Road, Gu-Su, Suzhou, 215000, Jiangsu Province, China.
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5
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Perera SD, Wang J, McIntyre AD, Hegele RA. Variability of longitudinal triglyceride phenotype in patients heterozygous for pathogenic APOA5 variants. J Clin Lipidol 2023; 17:659-665. [PMID: 37586912 DOI: 10.1016/j.jacl.2023.08.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2023] [Revised: 07/15/2023] [Accepted: 08/03/2023] [Indexed: 08/18/2023]
Abstract
BACKGROUND Biallelic pathogenic variants in APOA5 are an infrequent cause of familial chylomicronemia syndrome characterized by severe, refractory hypertriglyceridemia (HTG), and fasting plasma triglyceride (TG) >10 mmol/L (>875 mg/dL). The TG phenotype of heterozygous individuals with one copy of a pathogenic APOA5 variant is less familiar. We evaluated the longitudinal TG phenotype of individuals with a single pathogenic APOA5 variant allele. METHODS Medically stable outpatients from Ontario, Canada were selected for study based on having: 1) a rare pathogenic APOA5 variant in a single allele; and 2) at least three serial fasting TG measurements obtained over >1.5 years of follow-up. RESULTS Seven patients were followed for a mean of 5.3 ± 3.7 years. Fasting TG levels varied widely both within and between patients. Three patients displayed at least one normal TG measurement (<2.0 mmol/L or <175 mg/dL). All patients displayed mild-to-moderate HTG (2 to 9.9 mmol/L or 175 to 875 mg/dL) at multiple time points. Five patients displayed at least one severe HTG measurement. 10%, 54%, and 36% of all TG measurements were in normal, mild-to-moderate, and severe HTG ranges, respectively. CONCLUSIONS Heterozygosity for pathogenic variants in APOA5 is associated with highly variable TG phenotypes both within and between patients. Heterozygosity confers susceptibility to elevated TG levels, with secondary factors likely modulating the phenotypic severity.
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Affiliation(s)
- Shehan D Perera
- Robarts Research Institute, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada; Department of Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Jian Wang
- Robarts Research Institute, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Adam D McIntyre
- Robarts Research Institute, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Robert A Hegele
- Robarts Research Institute, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada; Department of Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada; Department of Medicine, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada.
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6
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Wen Y, Chen YQ, Konrad RJ. The Regulation of Triacylglycerol Metabolism and Lipoprotein Lipase Activity. Adv Biol (Weinh) 2022; 6:e2200093. [PMID: 35676229 DOI: 10.1002/adbi.202200093] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 05/03/2022] [Indexed: 01/28/2023]
Abstract
Triacylglycerol (TG) metabolism is tightly regulated to maintain a pool of TG within circulating lipoproteins that can be hydrolyzed in a tissue-specific manner by lipoprotein lipase (LPL) to enable the delivery of fatty acids to adipose or oxidative tissues as needed. Elevated serum TG concentrations, which result from a deficiency of LPL activity or, more commonly, an imbalance in the regulation of tissue-specific LPL activities, have been associated with an increased risk of atherosclerotic cardiovascular disease through multiple studies. Among the most critical LPL regulators are the angiopoietin-like (ANGPTL) proteins ANGPTL3, ANGPTL4, and ANGPTL8, and a number of different apolipoproteins including apolipoprotein A5 (ApoA5), apolipoprotein C2 (ApoC2), and apolipoprotein C3 (ApoC3). These ANGPTLs and apolipoproteins work together to orchestrate LPL activity and therefore play pivotal roles in TG partitioning, hydrolysis, and utilization. This review summarizes the mechanisms of action, epidemiological findings, and genetic data most relevant to these ANGPTLs and apolipoproteins. The interplay between these important regulators of TG metabolism in both fasted and fed states is highlighted with a holistic view toward understanding key concepts and interactions. Strategies for developing safe and effective therapeutics to reduce circulating TG by selectively targeting these ANGPTLs and apolipoproteins are also discussed.
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Affiliation(s)
- Yi Wen
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, 46285, USA
| | - Yan Q Chen
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, 46285, USA
| | - Robert J Konrad
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, 46285, USA
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Huang PP, Zhu WQ, Xiao JM, Zhang YQ, Li R, Yang Y, Shen L, Luo F, Dai W, Lian PA, Tang YX, Ran JL, Huang XS. Alterations in sorting and secretion of hepatic apoA5 induce hypertriglyceridemia due to short-term use of olanzapine. Front Pharmacol 2022; 13:935362. [PMID: 36034782 PMCID: PMC9411997 DOI: 10.3389/fphar.2022.935362] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 07/07/2022] [Indexed: 11/13/2022] Open
Abstract
Long-term use of olanzapine, an antipsychotic drug, induces hypertriglyceridemia, resulting in a higher risk of cardiovascular disease. However, the effects and underlying mechanisms of short-term use of olanzapine on circulating triglyceride levels remain poorly understood. Here, the role of apolipoprotein A5 (apoA5), a regulator of triglyceride metabolism, was investigated in olanzapine-induced hypertriglyceridemia. Our multi-center clinical study recruited 36 schizophrenia patients who received short-term (8 weeks) of olanzapine. Besides, female C57BL/6J mice were treated with olanzapine (3 mg/kg/day versus 6 mg/kg/day) for 6 weeks. We demonstrated that short-term use of olanzapine increased plasma triglyceride and decreased plasma apoA5 levels in the patients and mice, with a negative correlation between the two factors. However, no obesity was observed in the patients and mice. Interestingly, olanzapine increased hepatic apoA5 protein in the mice, without significant changes in hepatic Apoa5 mRNA. Consistently, in vitro studies indicated that olanzapine increased medium triglyceride levels and decreased medium apoA5 levels in a dose-dependent manner in human HepG2 cells and primary mouse hepatocytes. Whereas the olanzapine treatment increased hepatic apoA5 protein in vitro, without effects on hepatic APOA5 mRNA. Of note, olanzapine increased the co-localization between apoA5 protein and accumulated lipid droplets in hepatocytes, as opposed to at the hepatocellular plasma membrane, in mouse liver as demonstrated by fluorescence staining. Therefore, our study indicated that short-term use of olanzapine induced hypertriglyceridemia due to defects of sorting and secretion of hepatic apoA5.
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Affiliation(s)
- Piao-Piao Huang
- Department of Cardiovascular Medicine, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
- Research Institute of Blood Lipid and Atherosclerosis, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Wen-Qiang Zhu
- Department of Cardiovascular Medicine, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
- Research Institute of Blood Lipid and Atherosclerosis, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Jing-Mei Xiao
- National Clinical Research Center for Mental Disorders, and Department of Psychiatry, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China
| | - Yi-Qi Zhang
- Department of Critical Care Medicine, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Rong Li
- Department of Stomatology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Yang Yang
- Department of Cardiovascular Medicine, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
- Research Institute of Blood Lipid and Atherosclerosis, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Li Shen
- Department of Cardiovascular Medicine, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
- Research Institute of Blood Lipid and Atherosclerosis, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Fei Luo
- Department of Cardiovascular Medicine, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
- Research Institute of Blood Lipid and Atherosclerosis, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
- Department of Molecular Genetics, University of Texas Southwestern Medical Center at Dallas, Dallas, TX, United States
| | - Wen Dai
- Department of Cardiovascular Medicine, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
- Research Institute of Blood Lipid and Atherosclerosis, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
- Department of Medicine, Columbia University Medical Center, New York, NY, United States
| | - Ping-An Lian
- Department of Cardiovascular Medicine, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
- Research Institute of Blood Lipid and Atherosclerosis, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Ya-Xin Tang
- Department of Cardiovascular Medicine, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
- Research Institute of Blood Lipid and Atherosclerosis, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Juan-Li Ran
- Department of Stomatology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Xian-Sheng Huang
- Department of Cardiovascular Medicine, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
- Research Institute of Blood Lipid and Atherosclerosis, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
- *Correspondence: Xian-Sheng Huang,
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Genetic Factors Associated with Response to Vitamin E Treatment in NAFLD. Antioxidants (Basel) 2022; 11:antiox11071284. [PMID: 35883775 PMCID: PMC9311784 DOI: 10.3390/antiox11071284] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 06/15/2022] [Accepted: 06/20/2022] [Indexed: 12/07/2022] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) is becoming the predominant liver disease worldwide, and vitamin E has been clinically shown to improve histological parameters in a subset of patients. In this narrative review, we investigate whether genetic factors may help to explain why some patients show histological improvements upon high-dose alpha-tocopherol (αT) treatment while others do not. In summary, we identified two factors that are associated with treatment response, including genetic variations in haptoglobin as well as fatty acid desaturase 1/2 (FADS1/FADS2). Other genetic variants such as in alpha-tocopherol transfer protein (αTTP), tocopherol associated protein (TAP), transmembrane 6 superfamily 2 (TM6SF2), cluster of differentiation 36 (CD36), and proteins involved in lipoprotein metabolism may also play a role, but have not yet been investigated in a clinical context. We propose to further validate these associations in larger populations, to then use them as a clinical tool to identify the subset of patients that will benefit the most from vitamin E supplementation.
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Apolipoprotein A5, a unique modulator of fasting and postprandial triglycerides. Biochim Biophys Acta Mol Cell Biol Lipids 2022; 1867:159185. [DOI: 10.1016/j.bbalip.2022.159185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 04/30/2022] [Accepted: 05/13/2022] [Indexed: 11/19/2022]
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10
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The Importance of Lipoprotein Lipase Regulation in Atherosclerosis. Biomedicines 2021; 9:biomedicines9070782. [PMID: 34356847 PMCID: PMC8301479 DOI: 10.3390/biomedicines9070782] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 07/02/2021] [Accepted: 07/04/2021] [Indexed: 02/07/2023] Open
Abstract
Lipoprotein lipase (LPL) plays a major role in the lipid homeostasis mainly by mediating the intravascular lipolysis of triglyceride rich lipoproteins. Impaired LPL activity leads to the accumulation of chylomicrons and very low-density lipoproteins (VLDL) in plasma, resulting in hypertriglyceridemia. While low-density lipoprotein cholesterol (LDL-C) is recognized as a primary risk factor for atherosclerosis, hypertriglyceridemia has been shown to be an independent risk factor for cardiovascular disease (CVD) and a residual risk factor in atherosclerosis development. In this review, we focus on the lipolysis machinery and discuss the potential role of triglycerides, remnant particles, and lipolysis mediators in the onset and progression of atherosclerotic cardiovascular disease (ASCVD). This review details a number of important factors involved in the maturation and transportation of LPL to the capillaries, where the triglycerides are hydrolyzed, generating remnant lipoproteins. Moreover, LPL and other factors involved in intravascular lipolysis are also reported to impact the clearance of remnant lipoproteins from plasma and promote lipoprotein retention in capillaries. Apolipoproteins (Apo) and angiopoietin-like proteins (ANGPTLs) play a crucial role in regulating LPL activity and recent insights into LPL regulation may elucidate new pharmacological means to address the challenge of hypertriglyceridemia in atherosclerosis development.
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11
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Liu T, Chen JM, Zhang D, Zhang Q, Peng B, Xu L, Tang H. ApoPred: Identification of Apolipoproteins and Their Subfamilies With Multifarious Features. Front Cell Dev Biol 2021; 8:621144. [PMID: 33490085 PMCID: PMC7820372 DOI: 10.3389/fcell.2020.621144] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2020] [Accepted: 11/24/2020] [Indexed: 01/24/2023] Open
Abstract
Apolipoprotein is a group of plasma proteins that are associated with a variety of diseases, such as hyperlipidemia, atherosclerosis, Alzheimer’s disease, and diabetes. In order to investigate the function of apolipoproteins and to develop effective targets for related diseases, it is necessary to accurately identify and classify apolipoproteins. Although it is possible to identify apolipoproteins accurately through biochemical experiments, they are expensive and time-consuming. This work aims to establish a high-efficiency and high-accuracy prediction model for recognition of apolipoproteins and their subfamilies. We firstly constructed a high-quality benchmark dataset including 270 apolipoproteins and 535 non-apolipoproteins. Based on the dataset, pseudo-amino acid composition (PseAAC) and composition of k-spaced amino acid pairs (CKSAAP) were used as input vectors. To improve the prediction accuracy and eliminate redundant information, analysis of variance (ANOVA) was used to rank the features. And the incremental feature selection was utilized to obtain the best feature subset. Support vector machine (SVM) was proposed to construct the classification model, which could produce the accuracy of 97.27%, sensitivity of 96.30%, and specificity of 97.76% for discriminating apolipoprotein from non-apolipoprotein in 10-fold cross-validation. In addition, the same process was repeated to generate a new model for predicting apolipoprotein subfamilies. The new model could achieve an overall accuracy of 95.93% in 10-fold cross-validation. According to our proposed model, a convenient webserver called ApoPred was established, which can be freely accessed at http://tang-biolab.com/server/ApoPred/service.html. We expect that this work will contribute to apolipoprotein function research and drug development in relevant diseases.
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Affiliation(s)
- Ting Liu
- School of Basic Medical Sciences, Southwest Medical University, Luzhou, China
| | - Jia-Mao Chen
- School of Basic Medical Sciences, Southwest Medical University, Luzhou, China
| | - Dan Zhang
- Center for Informational Biology, University of Electronic Science and Technology of China, Chengdu, China
| | - Qian Zhang
- School of Basic Medical Sciences, Southwest Medical University, Luzhou, China
| | - Bowen Peng
- Division of international Cooperation, Health Commission of Sichuan Province, Chengdu, China
| | - Lei Xu
- School of Electronic and Communication Engineering, Shenzhen Polytechnic, Shenzhen, China
| | - Hua Tang
- School of Basic Medical Sciences, Southwest Medical University, Luzhou, China.,Central Nervous System Drug Key Laboratory of Sichuan Province, Luzhou, China
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12
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Castleberry M, Davis X, Liu M, Thompson TB, Tso P, Davidson WS. Functional recombinant apolipoprotein A5 that is stable at high concentrations at physiological pH. J Lipid Res 2020; 61:244-251. [PMID: 31831525 PMCID: PMC6997596 DOI: 10.1194/jlr.d119000103] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 11/25/2019] [Indexed: 11/20/2022] Open
Abstract
APOA5 is a low-abundance exchangeable apolipoprotein that plays critical roles in human triglyceride (TG) metabolism. Indeed, aberrations in the plasma concentration or structure of APOA5 are linked to hypertriglyceridemia, hyperchylomicronemia, myocardial infarction risk, obesity, and coronary artery disease. While it has been successfully produced at low yield in bacteria, the resulting protein had limitations for structure-function studies due to its low solubility under physiological buffer conditions. We hypothesized that the yield and solubility of recombinant APOA5 could be increased by: i) engineering a fusion protein construct in a codon optimized expression vector, ii) optimizing an efficient refolding protocol, and iii) screening buffer systems at physiological pH. The result was a high-yield (25 mg/l) bacterial expression system that produces lipid-free APOA5 soluble at concentrations of up to 10 mg/ml at a pH of 7.8 in bicarbonate buffers. Physical characterization of lipid-free APOA5 indicated that it exists as an array of multimers in solution, and far UV circular dichroism analyses show differences in total α-helicity between acidic and neutral pH buffering conditions. The protein was functional in that it bound and emulsified multilamellar dimyristoyl-phosphatidylcholine vesicles and could inhibit postprandial plasma TG accumulation when injected into C57BL/6J mice orally gavaged with Intralipid.
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Affiliation(s)
- Mark Castleberry
- Departments of Molecular Genetics, Biochemistry, and Microbiology University of Cincinnati College of Medicine, Cincinnati, OH
| | - Xenia Davis
- Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, OH
| | - Min Liu
- Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, OH
| | - Thomas B Thompson
- Departments of Molecular Genetics, Biochemistry, and Microbiology University of Cincinnati College of Medicine, Cincinnati, OH
| | - Patrick Tso
- Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, OH
| | - W Sean Davidson
- Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, OH
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13
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Ashraf Y, Duval S, Sachan V, Essalmani R, Susan-Resiga D, Roubtsova A, Hamelin J, Gerhardy S, Kirchhofer D, Tagliabracci VS, Prat A, Kiss RS, Seidah NG. Proprotein convertase 7 (PCSK7) reduces apoA-V levels. FEBS J 2020; 287:3565-3578. [PMID: 31945259 DOI: 10.1111/febs.15212] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Revised: 11/07/2019] [Accepted: 01/10/2020] [Indexed: 01/24/2023]
Abstract
The locus of the human proprotein convertase subtilisin-kexin type-7 (PC7) gene (PCSK7) is on chromosome 11q23.3 close to the gene cluster APOA5/APOA4/APOC3/APOA1, a region implicated in the regulation of lipoprotein metabolism. A GWAS reported the association of PCSK7 SNPs with plasma triglyceride (TG), and exome sequencing of African Americans revealed the association of a low-frequency coding variant of PC7 (R504H; SNP rs142953140) with a ~ 30% TG reduction. Another PCSK7 SNP rs508487 is in linkage disequilibrium with a promoter variant of the liver-derived apolipoprotein A-V (apoA-V), an indirect activator of the lipoprotein lipase (LpL), and is associated with elevated TG levels. We thus hypothesized that PC7 regulates the levels/activity of apoA-V. Studies in the human hepatic cell line HuH7 revealed that wild-type (WT) PC7 and its endoplasmic reticulum (ER)-retained forms bind to and enhance the degradation of human apoA-V in acidic lysosomes in a nonenzymatic fashion. PC7-induced degradation of apoA-V is inhibited by bafilomycin A1 and the alkalinizing agents: chloroquine and NH4 Cl. Thus, the PC7-induced apoA-V degradation implicates an ER-lysosomal communication inhibited by bafilomycin A1. In vitro, the natural R504H mutant enhances PC7 Ser505 phosphorylation at the structurally exposed Ser-X-Glu507 motif recognized by the secretory kinase Fam20C. Co-expression of the phosphomimetic PC7-S505E with apoA-V resulted in lower degradation compared to WT, suggesting that Ser505 phosphorylation of PC7 lowers TG levels via reduced apoA-V degradation. In agreement, in Pcsk7-/- mice fed high-fat diet, plasma apoA-V levels and adipocyte LpL activity are increased, providing an in vivo mechanistic link for a role of liver PC7 in enhanced TG storage in adipocytes.
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Affiliation(s)
- Yahya Ashraf
- Laboratory of Biochemical Neuroendocrinology, Clinical Research Institute of Montreal, QC, Canada
| | - Stéphanie Duval
- Laboratory of Biochemical Neuroendocrinology, Clinical Research Institute of Montreal, QC, Canada
| | - Vatsal Sachan
- Laboratory of Biochemical Neuroendocrinology, Clinical Research Institute of Montreal, QC, Canada
| | - Rachid Essalmani
- Laboratory of Biochemical Neuroendocrinology, Clinical Research Institute of Montreal, QC, Canada
| | - Delia Susan-Resiga
- Laboratory of Biochemical Neuroendocrinology, Clinical Research Institute of Montreal, QC, Canada
| | - Anna Roubtsova
- Laboratory of Biochemical Neuroendocrinology, Clinical Research Institute of Montreal, QC, Canada
| | - Josée Hamelin
- Laboratory of Biochemical Neuroendocrinology, Clinical Research Institute of Montreal, QC, Canada
| | - Stefan Gerhardy
- Early Discovery Biochemistry, Genentech Inc., South San Francisco, CA, USA
| | - Daniel Kirchhofer
- Early Discovery Biochemistry, Genentech Inc., South San Francisco, CA, USA
| | - Vincent S Tagliabracci
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Annik Prat
- Laboratory of Biochemical Neuroendocrinology, Clinical Research Institute of Montreal, QC, Canada
| | - Robert Scott Kiss
- Research Institute, McGill University Health Center, Montreal, QC, Canada
| | - Nabil G Seidah
- Laboratory of Biochemical Neuroendocrinology, Clinical Research Institute of Montreal, QC, Canada
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14
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High density lipoprotein promotes nascent apolipoprotein A-V secretion from mRNA transfected cells. Biochem Biophys Res Commun 2019; 512:387-391. [PMID: 30902391 DOI: 10.1016/j.bbrc.2019.03.087] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Accepted: 03/15/2019] [Indexed: 01/09/2023]
Abstract
Despite its exceptionally low circulating concentration, apolipoprotein (apo) A-V is a potent modulator of plasma triacylglycerol levels. The secretion efficiency of nascent apoA-V was investigated in cultured cells transfected with mRNA. Following transfection of HepG2 cells with wild type apoA-V mRNA, apoA-V protein was detectable in cell lysates by 6 h. At 24 h post transfection, evidence of apoA-V secretion into media was obtained, although most apoA-V was recovered in the cell lysate fraction. By contrast, apoA-I was efficiently secreted into the culture medium. A positive correlation between culture medium fetal bovine serum content and the percentage of apoA-V recovered in conditioned media was observed. When transfected cells were cultured in serum-free media supplemented with increasing amounts of high density lipoprotein, a positive correlation with apoA-V secretion was observed. The data indicate that, following signal sequence cleavage, the bulk of nascent apoA-V remains cell associated. Transit of nascent apoA-V out of cultured cells is enhanced by the availability of extracellular lipid particle acceptors.
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15
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Treviño-Villarreal JH, Reynolds JS, Bartelt A, Langston PK, MacArthur MR, Arduini A, Tosti V, Veronese N, Bertozzi B, Brace LE, Mejia P, Trocha K, Kajitani GS, Longchamp A, Harputlugil E, Gathungu R, Bird SS, Bullock AD, Figenshau RS, Andriole GL, Thompson A, Heeren J, Ozaki CK, Kristal BS, Fontana L, Mitchell JR. Dietary protein restriction reduces circulating VLDL triglyceride levels via CREBH-APOA5-dependent and -independent mechanisms. JCI Insight 2018; 3:99470. [PMID: 30385734 DOI: 10.1172/jci.insight.99470] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Accepted: 09/11/2018] [Indexed: 12/14/2022] Open
Abstract
Hypertriglyceridemia is an independent risk factor for cardiovascular disease. Dietary interventions based on protein restriction (PR) reduce circulating triglycerides (TGs), but underlying mechanisms and clinical relevance remain unclear. Here, we show that 1 week of a protein-free diet without enforced calorie restriction significantly lowered circulating TGs in both lean and diet-induced obese mice. Mechanistically, the TG-lowering effect of PR was due, in part, to changes in very low-density lipoprotein (VLDL) metabolism both in liver and peripheral tissues. In the periphery, PR stimulated VLDL-TG consumption by increasing VLDL-bound APOA5 expression and promoting VLDL-TG hydrolysis and clearance from circulation. The PR-mediated increase in Apoa5 expression was controlled by the transcription factor CREBH, which coordinately regulated hepatic expression of fatty acid oxidation-related genes, including Fgf21 and Ppara. The CREBH-APOA5 axis activation upon PR was intact in mice lacking the GCN2-dependent amino acid-sensing arm of the integrated stress response. However, constitutive hepatic activation of the amino acid-responsive kinase mTORC1 compromised CREBH activation, leading to blunted APOA5 expression and PR-recalcitrant hypertriglyceridemia. PR also contributed to hypotriglyceridemia by reducing the rate of VLDL-TG secretion, independently of activation of the CREBH-APOA5 axis. Finally, a randomized controlled clinical trial revealed that 4-6 weeks of reduced protein intake (7%-9% of calories) decreased VLDL particle number, increased VLDL-bound APOA5 expression, and lowered plasma TGs, consistent with mechanistic conservation of PR-mediated hypotriglyceridemia in humans with translational potential as a nutraceutical intervention for dyslipidemia.
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Affiliation(s)
| | - Justin S Reynolds
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - Alexander Bartelt
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA.,Sabri Ülker Center for Nutrient, Genetic, and Metabolic Research, Boston, Massachusetts, USA.,Institute for Cardiovascular Prevention (IPEK), Ludwig-Maximilians-University, Munich, Germany.,German Center for Cardiovascular Research (DZHK), Partner Site Munich Heart Alliance, Munich, Germany
| | - P Kent Langston
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - Michael R MacArthur
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - Alessandro Arduini
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA.,Sabri Ülker Center for Nutrient, Genetic, and Metabolic Research, Boston, Massachusetts, USA
| | - Valeria Tosti
- Department of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Nicola Veronese
- Department of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Beatrice Bertozzi
- Department of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Lear E Brace
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - Pedro Mejia
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - Kaspar Trocha
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA.,Division of Vascular and Endovascular Surgery, Department of Surgery, and
| | - Gustavo S Kajitani
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - Alban Longchamp
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA.,Division of Vascular and Endovascular Surgery, Department of Surgery, and
| | - Eylul Harputlugil
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - Rose Gathungu
- Division of Sleep and Circadian Disorders, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts.,Division of Sleep Medicine, Department of Medicine, Harvard Medical School (HMS), Boston, Massachusetts, USA
| | - Susan S Bird
- Department of Neurosurgery, Brigham and Women's Hospital, Boston, Massachusetts, USA.,Department of Surgery, HMS, Boston, Massachusetts, USA
| | - Arnold D Bullock
- Division of Urology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Robert S Figenshau
- Division of Urology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Gerald L Andriole
- Division of Urology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Andrew Thompson
- Dana Farber Cancer Institute/HMS Rodent Histopathology Core Facility, HMS, Boston, Massachusetts, USA
| | - Jöerg Heeren
- Department for Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Germany
| | - C Keith Ozaki
- Division of Vascular and Endovascular Surgery, Department of Surgery, and
| | - Bruce S Kristal
- Division of Sleep and Circadian Disorders, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts.,Division of Sleep Medicine, Department of Medicine, Harvard Medical School (HMS), Boston, Massachusetts, USA.,Department of Neurosurgery, Brigham and Women's Hospital, Boston, Massachusetts, USA.,Department of Surgery, HMS, Boston, Massachusetts, USA
| | - Luigi Fontana
- Department of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA.,Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy.,School of Medicine and Charles Perkins Centre, University of Sydney, Sydney, Australia
| | - James R Mitchell
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
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16
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Zafar U, Khaliq S, Ahmad HU, Manzoor S, Lone KP. Metabolic syndrome: an update on diagnostic criteria, pathogenesis, and genetic links. Hormones (Athens) 2018; 17:299-313. [PMID: 30171523 DOI: 10.1007/s42000-018-0051-3] [Citation(s) in RCA: 107] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Accepted: 06/19/2018] [Indexed: 02/06/2023]
Abstract
Metabolic syndrome (MetS), today a major global public health problem, is a cluster of clinical, metabolic, and biochemical abnormalities, such as central adiposity, hypertension, insulin resistance, and dyslipidemias. These MetS-related traits significantly increase the risk of type 2 diabetes mellitus, adverse cardiac events, stroke, and hepatic steatosis. The pathogenesis of MetS is multifactorial, with the interplay of environmental, nutritional, and genetic factors. Chronic low-grade inflammation together with visceral adipose tissue, adipocyte dysfunction, and insulin resistance plays a major role in the progression of the syndrome by impairing lipid and glucose homeostasis in insulin-sensitive tissues, such as the liver, muscle, and adipocytes. Adipose-derived inflammatory cytokines and non-esterified fatty acids establish the link between central obesity IR, inflammation, and atherogenesis. Various studies have reported an association between MetS and related traits with single-nucleotide polymorphisms of different susceptibility genes. Modulation of cytokine levels, pro-oxidants, and disturbed energy homeostasis, in relation to the genetic variations, is described in this review of the recent literature, which also provides updated data regarding the epidemiology, diagnostic criteria, and pathogenesis of MetS.
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Affiliation(s)
- Uzma Zafar
- Department of Physiology & Cell Biology, University of Health Sciences, Lahore, Pakistan.
- Department of Physiology, Lahore Medical and Dental College, Lahore, Pakistan.
| | - Saba Khaliq
- Department of Physiology & Cell Biology, University of Health Sciences, Lahore, Pakistan
| | - Hafiz Usman Ahmad
- Department of Physiology & Cell Biology, University of Health Sciences, Lahore, Pakistan
| | - Sobia Manzoor
- Department of Healthcare Biotechnology, Atta-ur-Rahman School of Applied Biosciences, NUST, Islamabad, Pakistan
| | - Khalid P Lone
- Department of Physiology & Cell Biology, University of Health Sciences, Lahore, Pakistan.
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17
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Su X, Kong Y, Peng DQ. New insights into apolipoprotein A5 in controlling lipoprotein metabolism in obesity and the metabolic syndrome patients. Lipids Health Dis 2018; 17:174. [PMID: 30053818 PMCID: PMC6064078 DOI: 10.1186/s12944-018-0833-2] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2018] [Accepted: 07/20/2018] [Indexed: 01/01/2023] Open
Abstract
Apolipoprotein A5 (apoA5) has been identified to play an important role in lipid metabolism, specifically in triglyceride (TG) and TG-rich lipoproteins (TRLs) metabolism. Numerous evidence has demonstrated for an association between apoA5 and the increased risk of obesity and metabolic syndrome, but the mechanism remains to be fully elucidated. Recently, several studies verified that apoA5 could significantly reduce plasma TG level by stimulating lipoprotein lipase (LPL) activity, and the intracellular role of apoA5 has also been proved since apoA5 is associated with cytoplasmic lipid droplets (LDs) and affects intrahepatic TG accumulation. Furthermore, since adipocytes provide the largest storage depot for TG and play a crucial role in the development of obesity, we could infer that apoA5 also acts as a novel regulator to modulate TG storage in adipocytes. In this review, we focus on the association of gene and protein of apoA5 with obesity and metabolic syndrome, and provide new insights into the physiological role of apoA5 in humans, giving a potential therapeutic target for obesity and associated disorders.
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Affiliation(s)
- Xin Su
- Department of Cardiovascular Medicine, the Second Xiangya Hospital, Central South University, Changsha, 410011, Hunan, China
| | - Yi Kong
- Department of Dermatology, Hunan Key Laboratory of Medical Epigenomics, the Second Xiangya Hospital, Central South University, Changsha, 410011, Hunan, China
| | - Dao-Quan Peng
- Department of Cardiovascular Medicine, the Second Xiangya Hospital, Central South University, Changsha, 410011, Hunan, China.
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18
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Wang F, Wang IZ, Ellis S, Archacki S, Barnard J, Hubbard C, Topol EJ, Chen Q, Wang QK. Analysis of causal effect of APOA5 variants on premature coronary artery disease. Ann Hum Genet 2018; 82:437-447. [PMID: 30024021 DOI: 10.1111/ahg.12273] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2018] [Revised: 05/17/2018] [Accepted: 06/18/2018] [Indexed: 11/30/2022]
Abstract
Apolipoprotein A5 (APOA5) regulates the metabolisms of triglyceride and HDL. APOA5 variants have been linked to coronary artery disease (CAD), but their causal roles are not well studied yet. This study aims to identify the causal effects of APOA5 variants on premature CAD. Sequencing analysis of APOA5 in 128 premature, familiar CAD patients from GeneQuest identified 11 genomic variants, including p.S19W (rs3135506). SKAT analysis showed that all sequenced variants, in aggregate, significantly increased the risk of premature CAD (P-skat = 0.037). Individually, the p.S19W variant was significantly associated with risk of premature CAD (OR = 2.30, P = 0.008) in an independent set of 342 premature CAD patients and 537 controls after adjusting for covariates of sex, age, hypertension, body mass index, triglycerides (TGs), and total, LDL-, and HDL-cholesterol levels. Meanwhile, p.S19W significantly correlated with HDL-C levels (P = 0.048) and TG levels (P = 0.025). Mediation analysis yielded a mediation effect of p.S19W on risk of premature CAD through HDL-C (OR = 0.98, P = 0.040) and TG (OR = 0.98, P = 0.042), suggesting a causal relationship between p.S19W and premature CAD partially through its effects on HDL-C and TG levels. These results suggest that APOA5 variation regulates TG and HDL levels, thus displaying a causal role in the development of CAD.
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Affiliation(s)
- Fan Wang
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA.,Department of Molecular Medicine, Department of Genetics and Genome Science, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH, USA
| | - Isabel Z Wang
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA.,Shaker Heights High School, Shaker Heights, OH, USA
| | - Stephen Ellis
- Department of Cardiovascular Medicine, Sydell & Arnold Miller Family Heart & Vascular Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Stephen Archacki
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA.,Department of Molecular Medicine, Department of Genetics and Genome Science, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH, USA
| | - John Barnard
- Department of Quantitative Health Sciences, Cleveland Clinic, Cleveland, OH, USA
| | - Carlos Hubbard
- Department of Cardiovascular Medicine, Sydell & Arnold Miller Family Heart & Vascular Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Eric J Topol
- Scripps Translational Science Institute, Scripps Research Institute, Scripps Clinic, La Jolla, CA, USA
| | - Qiuyun Chen
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA.,Department of Molecular Medicine, Department of Genetics and Genome Science, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH, USA
| | - Qing K Wang
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA.,Department of Molecular Medicine, Department of Genetics and Genome Science, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH, USA.,Department of Cardiovascular Medicine, Sydell & Arnold Miller Family Heart & Vascular Institute, Cleveland Clinic, Cleveland, OH, USA.,The Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Center for Human Genome Research, Cardio-X Institute, Huazhong University of Science and Technology, Wuhan, P. R. China
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19
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Jasim AA, Al-Bustan SA, Al-Kandari W, Al-Serri A, AlAskar H. Sequence Analysis of APOA5 Among the Kuwaiti Population Identifies Association of rs2072560, rs2266788, and rs662799 With TG and VLDL Levels. Front Genet 2018; 9:112. [PMID: 29686695 PMCID: PMC5900548 DOI: 10.3389/fgene.2018.00112] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Accepted: 03/21/2018] [Indexed: 11/13/2022] Open
Abstract
Common variants of Apolipoprotein A5 (APOA5) have been associated with lipid levels yet very few studies have reported full sequence data from various ethnic groups. The purpose of this study was to analyse the full APOA5 gene sequence to identify variants in 100 healthy Kuwaitis of Arab ethnicities and assess their association with variation in lipid levels in a cohort of 733 samples. Sanger method was used in the direct sequencing of the full 3.7 Kb APOA5 and multiple sequence alignment was used to identify variants. The complete APOA5 sequence in Kuwaiti Arabs has been deposited in GenBank (KJ401315). A total of 20 reported single nucleotide polymorphisms (SNPs) were identified. Two novel SNPs were also identified: a synonymous 2197G>A polymorphism at genomic position 116661525 and a 3′ UTR 3222 C>T polymorphism at genomic position 116660500 based on human genome assembly GRCh37/hg:19. Five SNPs along with the two novel SNPs were selected for validation in the cohort. Association of those SNPs with lipid levels was tested and minor alleles of three SNPs (rs2072560, rs2266788, and rs662799) were found significantly associated with TG and VLDL levels. This is the first study to report the full APOA5 sequence and SNPs in an Arab ethnic group. Analysis of the variants identified and comparison to other populations suggests a distinctive genetic component in Arabs. The positive association observed for rs2072560 and rs2266788 with TG and VLDL levels confirms their role in lipid metabolism.
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Affiliation(s)
- Anfal A Jasim
- Department of Biological Sciences, Faculty of Science, Kuwait University, Kuwait, Kuwait
| | - Suzanne A Al-Bustan
- Department of Biological Sciences, Faculty of Science, Kuwait University, Kuwait, Kuwait
| | - Wafa Al-Kandari
- Department of Biological Sciences, Faculty of Science, Kuwait University, Kuwait, Kuwait
| | - Ahmad Al-Serri
- Human Genetics Unit, Department of Pathology, Faculty of Medicine, Kuwait University, Kuwait, Kuwait
| | - Huda AlAskar
- Department of Biological Sciences, Faculty of Science, Kuwait University, Kuwait, Kuwait
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20
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Han Y, Dorajoo R, Chang X, Wang L, Khor CC, Sim X, Cheng CY, Shi Y, Tham YC, Zhao W, Chee ML, Sabanayagam C, Chee ML, Tan N, Wong TY, Tai ES, Liu J, Goh DYT, Yuan JM, Koh WP, van Dam RM, Low AF, Chan MYY, Friedlander Y, Heng CK. Genome-wide association study identifies a missense variant at APOA5 for coronary artery disease in Multi-Ethnic Cohorts from Southeast Asia. Sci Rep 2017; 7:17921. [PMID: 29263402 PMCID: PMC5738399 DOI: 10.1038/s41598-017-18214-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 12/01/2017] [Indexed: 12/19/2022] Open
Abstract
Recent genome-wide association studies (GWAS) have identified multiple loci associated with coronary artery disease (CAD) among predominantly Europeans. However, their relevance to multi-ethnic populations from Southeast Asia is largely unknown. We performed a meta-analysis of four GWAS comprising three Chinese studies and one Malay study (Total N = 2,169 CAD cases and 7,376 controls). Top hits (P < 5 × 10-8) were further evaluated in 291 CAD cases and 1,848 controls of Asian Indians. Using all datasets, we validated recently identified loci associated with CAD. The involvement of known canonical pathways in CAD was tested by Ingenuity Pathway Analysis. We identified a missense SNP (rs2075291, G > T, G185C) in APOA5 for CAD that reached robust genome-wide significance (Meta P = 7.09 × 10-10, OR = 1.636). Conditional probability analysis indicated that the association at rs2075291 was independent of previously reported index SNP rs964184 in APOA5. We further replicated 10 loci previously identified among predominantly Europeans (P: 1.33 × 10-7-0.047). Seven pathways (P: 1.10 × 10-5-0.019) were identified. We identified a missense SNP, rs2075291, in APOA5 associated with CAD at a genome-wide significance level and provided new insights into pathways contributing to the susceptibility to CAD in the multi-ethnic populations from Southeast Asia.
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Affiliation(s)
- Yi Han
- Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore; and Khoo Teck Puat - National University Children's Medical Institute, National University Health System, Singapore, Singapore
| | - Rajkumar Dorajoo
- Genome Institute of Singapore, Agency for Science, Technology and Research, Singapore, Singapore
| | - Xuling Chang
- Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore; and Khoo Teck Puat - National University Children's Medical Institute, National University Health System, Singapore, Singapore
| | - Ling Wang
- Genome Institute of Singapore, Agency for Science, Technology and Research, Singapore, Singapore
| | - Chiea-Chuen Khor
- Genome Institute of Singapore, Agency for Science, Technology and Research, Singapore, Singapore
| | - Xueling Sim
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore, Singapore
| | - Ching-Yu Cheng
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
- Ophthalmology & Visual Sciences Academic Clinical Program (Eye ACP), Duke-NUS Medical School, Singapore, Singapore
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Yuan Shi
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
| | - Yih Chung Tham
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
| | - Wanting Zhao
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
| | - Miao Ling Chee
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
| | - Charumathi Sabanayagam
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
- Centre for Quantitative Medicine, Duke-NUS Graduate Medical School, Singapore, Singapore
| | - Miao Li Chee
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
| | - Nicholas Tan
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
- Department of Ophthalmology, National University Hospital, Singapore, Singapore
| | - Tien Yin Wong
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
- Ophthalmology & Visual Sciences Academic Clinical Program (Eye ACP), Duke-NUS Medical School, Singapore, Singapore
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - E-Shyong Tai
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore, Singapore
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, National University Health System, Singapore, Singapore
| | - Jianjun Liu
- Genome Institute of Singapore, Agency for Science, Technology and Research, Singapore, Singapore
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore, Singapore
| | - Daniel Y T Goh
- Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore; and Khoo Teck Puat - National University Children's Medical Institute, National University Health System, Singapore, Singapore
| | - Jian-Min Yuan
- Department of Epidemiology, Graduate School of Public Health; and University of Pittsburgh Cancer Institute, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Woon-Puay Koh
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore, Singapore
- Duke-NUS Graduate Medical School Singapore, Singapore, Singapore
| | - Rob M van Dam
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore, Singapore
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, National University Health System, Singapore, Singapore
| | - Adrian F Low
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- National University Heart Centre, National University Health System, Singapore, Singapore
| | - Mark Yan-Yee Chan
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Yechiel Friedlander
- School of Public Health and Community Medicine, Hebrew University of Jerusalem, Jerusalem, Israel.
| | - Chew-Kiat Heng
- Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore; and Khoo Teck Puat - National University Children's Medical Institute, National University Health System, Singapore, Singapore.
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Zemánková K, Dembovská R, Piťha J, Kovář J. Glucose added to a fat load suppresses the postprandial triglyceridemia response in carriers of the -1131C and 56G variants of the APOA5 gene. Physiol Res 2017; 66:859-866. [PMID: 28730827 DOI: 10.33549/physiolres.933552] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Apolipoprotein A-V plays an important role in the determination of plasma triglyceride (TG) concentration. We aimed to determine whether polymorphisms -1131T>C (rs662799) and 56C>G (rs3135506) of the APOA5 gene have an impact on the course of postprandial lipemia induced by a fat load and a fat load with added glucose. Thirty healthy male volunteers, seven heterozygous for the -1131C variant and three for the 56G variant (HT) carriers, and 20 wild-type (WT) carriers underwent two 8-hour tests of postprandial lipemia - one after an experimental breakfast consisting of 75 g of fat and second after a breakfast consisting of 75 g of fat and 25 g of glucose. HT carriers had a higher postprandial response after fat load than WT carriers (AUC TG: 14.01+/-4.27 vs. 9.84+/-3.32 mmol*h/l, respectively, p=0.016). Glucose added to the test meal suppressed such a difference. Heterozygous carriers of the variants of APOA5 (-1131C and 56G) display more pronounced postprandial lipemia after pure fat load than WT carriers. This statistically significant difference disappears when glucose is added to a fat load, suggesting that meal composition modulates the effect of these polymorphisms on the magnitude of postprandial lipemia.
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Affiliation(s)
- K Zemánková
- Laboratory for Atherosclerosis Research, Institute for Clinical and Experimental Medicine, Prague, Czech Republic.
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Sharma D, Garg S, Mehndiratta M, V Madhu S, Puri D. Relationship of Serum Apolipoprotein A-V Levels, Oxidative Stress and Inflammatory Biomarkers with Hypertriglyceridemia in Type 2 Diabetes Mellitus. Int J Endocrinol Metab 2017; 15:e44805. [PMID: 28848612 PMCID: PMC5556325 DOI: 10.5812/ijem.44805] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Revised: 02/28/2017] [Accepted: 04/08/2017] [Indexed: 12/04/2022] Open
Abstract
BACKGROUND Serum levels of triglycerides (TGs) are often found to be raised in type 2 diabetes mellitus (T2DM). TG levels ≥ 2.2 mM, systemic inflammation and oxidative stress (OS) are known to increase the risk of incident cardiovascular disease (CVD) substantially. In recent years, apolipoprotein A-V (Apo A-V protein) has attracted considerably as a modulator of circulating TG levels. OBJECTIVES The study was conducted in order to evaluate the levels of Apo A - V proteins and markers of inflammation and OS in patients of T2DM with and without hypertriglyceridemia (HTG) and also to assess correlation between them. METHODS T2DM patients were categorized into two groups of 40 participants, according to criteria for risk of CVD: group 1/ controls (TG ≤ 1.65 mM, n = 40) and group 2/ cases (TG ≥ 2.2 mM, n = 40). Despite the routine investigations, serum levels of Apo A-V, interleukin-6 (IL-6) and Insulin were estimated using ELISA, free fatty acids (FFA) with fluorometric assay and malondialdehyde (MDA) was measured using a spectrophotometer. Comparison of levels and correlation between variables was carried out with appropriate statistical tools. RESULTS Serum Apo A-V protein levels were found significantly lower (P = 0.04) and MDA was significantly higher (P = 0.049) in cases. MDA correlated with TG levels positively (P = 0.000) and negatively with high density lipoproteins (HDL) (P = 0.000). However Apo A-V protein levels did not correlate with TG levels (P = 0.819, r = -0.027), IL-6 (r = 0.135, P = 0.269), FFA (r = 0.128, P = 0.277) and MDA (r = -0.217, P = 0.073). IL-6 levels significantly and positively correlated with HOMA-IR (r = 0.327, P = 0.004) in the all patients. CONCLUSIONS In patients of T2DM, low levels of Apo A-V are associated with HTG, indicating that Apo A-V is linked with TG metabolism. Burden of oxidative stress is greater in HTG of T2DM as is evident from MDA levels and its correlation with TG levels. Since oxidative stress is an important patho-physiological basis which increases the risk of CVD in patients of T2DM with HTG. Further studies are required in order to explore the possible role of Apo A-V in TG metabolism in diabetes.
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Affiliation(s)
- Devesh Sharma
- Departement of Biochemistry, University College of Medical Sciences and GTB Hospital, University of Delhi, Delhi, India
| | - Seema Garg
- Departement of Biochemistry, University College of Medical Sciences and GTB Hospital, University of Delhi, Delhi, India
- Corresponding author: Seema Garg, Department of Biochemistry, University College of Medical Sciences, Dilshad Garden, Delhi. Tel: +011-225829745206, E-mail:
| | - Mohit Mehndiratta
- Departement of Biochemistry, University College of Medical Sciences and GTB Hospital, University of Delhi, Delhi, India
| | - S V Madhu
- Department of Medicine, University College of Medical Sciences and GTB Hospital, University of Delhi, Delhi, India
| | - Dinesh Puri
- Departement of Biochemistry, University College of Medical Sciences and GTB Hospital, University of Delhi, Delhi, India
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He H, Lei L, Chen E, Dong J, Zhang K, Yang J. The c.553G>T Genetic Variant of the APOA5 Gene and Altered Triglyceride Levels in the Asian Population: A Meta-Analysis of Case-Control Studies. Genet Test Mol Biomarkers 2016; 20:758-765. [PMID: 27813673 DOI: 10.1089/gtmb.2016.0047] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
AIM To explore the association of the APOA5 gene c.553G>T polymorphism with hypertriglyceridemia (HTG) susceptibility and altered triglyceride levels. METHODS We searched the PubMed, Google Scholar, and CNKI databases for published studies relating to analyses of these associations. Case-control and comparative studies of the association between the APOA5 c.553G>T variant and altered triglyceride levels were included. In total, the meta-analysis involved 10 studies on HTG, which provided 2219 cases and 3401 controls. To measure the correlation between the c.553G>T polymorphism and HTG susceptibility, odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. The overall OR was calculated using a random-effects model. RESULTS Compared with APOA5 c.553 GG carriers, c.553T carriers displayed an increased risk of HTG in the Asian population, with an overall random effects OR of 3.55 (95% CI: 2.46-5.13) in the dominant model. There was significant heterogeneity among the studies (Pheterogeneity: Chi2 = 45.80, I2 = 75.98%), which may be largely explained by certain patient types. Both the sensitivity analysis and publication bias suggested that the overall result was acceptable. Subgroup analysis showed a large difference in serum triglyceride levels based on the c.553 G > T polymorphism in healthy individuals and HTG patients. APOA5 c.553T carriers exhibit higher triglyceride levels than GG carriers. CONCLUSION Our results suggest that APOA5 c. 553T is an independent risk factor for HTG and increased triglyceride levels in the Asian population. APOA5 c. 553T could be employed as a genetic risk marker for HTG and increased triglyceride levels.
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Affiliation(s)
- Hongjuan He
- College of Life Science, Institute of Preventive Genomic Medicine, Northwest University , Xi'an, China
| | - Lei Lei
- College of Life Science, Institute of Preventive Genomic Medicine, Northwest University , Xi'an, China
| | - Erfei Chen
- College of Life Science, Institute of Preventive Genomic Medicine, Northwest University , Xi'an, China
| | - Jing Dong
- College of Life Science, Institute of Preventive Genomic Medicine, Northwest University , Xi'an, China
| | - Kejin Zhang
- College of Life Science, Institute of Preventive Genomic Medicine, Northwest University , Xi'an, China
| | - Jin Yang
- College of Life Science, Institute of Preventive Genomic Medicine, Northwest University , Xi'an, China
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Zhang LS, Xu M, Yang Q, Ryan RO, Howles P, Tso P. Apolipoprotein A-V deficiency enhances chylomicron production in lymph fistula mice. Am J Physiol Gastrointest Liver Physiol 2015; 308:G634-42. [PMID: 25617349 PMCID: PMC4385892 DOI: 10.1152/ajpgi.00339.2014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Accepted: 01/16/2015] [Indexed: 01/31/2023]
Abstract
Apolipoprotein A-V (apoA-V), a liver-synthesized apolipoprotein discovered in 2001, strongly modulates fasting plasma triglycerides (TG). Little is reported on the effect of apoA-V on postprandial plasma TG, an independent predictor for atherosclerosis. Overexpressing apoA-V in mice suppresses postprandial TG, but mechanisms focus on increased lipolysis or clearance of remnant particles. Unknown is whether apoA-V suppresses the absorption of dietary lipids by the gut. This study examines how apoA-V deficiency affects the steady-state absorption and lymphatic transport of dietary lipids in chow-fed mice. Using apoA-V knockout (KO, n = 8) and wild-type (WT, n = 8) lymph fistula mice, we analyzed the uptake and lymphatic transport of lipids during a continuous infusion of an emulsion containing [(3)H]triolein and [(14)C]cholesterol. ApoA-V KO mice showed a twofold increase in (3)H (P < 0.001) and a threefold increase in (14)C (P < 0.001) transport into the lymph compared with WT. The increased lymphatic transport was accompanied by a twofold reduction (P < 0.05) in mucosal (3)H, suggesting that apoA-V KO mice more rapidly secreted [(3)H]TG out of the mucosa into the lymph. ApoA-V KO mice also produced chylomicrons more rapidly than WT (P < 0.05), as measured by the transit time of [(14)C]oleic acid from the intestinal lumen to lymph. Interestingly, apoA-V KO mice produced a steadily increasing number of chylomicron particles over time, as measured by lymphatic apoB output. The data suggest that apoA-V suppresses the production of chylomicrons, playing a previously unknown role in lipid metabolism that may contribute to the postprandial hypertriglyceridemia associated with apoA-V deficiency.
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Affiliation(s)
- Linda S. Zhang
- 1Children's Hospital Oakland Research Institute, Oakland, California
| | - Min Xu
- 1Children's Hospital Oakland Research Institute, Oakland, California
| | - Qing Yang
- 1Children's Hospital Oakland Research Institute, Oakland, California
| | - Robert O. Ryan
- 2Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio; and
| | - Philip Howles
- 1Children's Hospital Oakland Research Institute, Oakland, California
| | - Patrick Tso
- 1Children's Hospital Oakland Research Institute, Oakland, California
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Amyloid-Forming Properties of Human Apolipoproteins: Sequence Analyses and Structural Insights. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2015; 855:175-211. [PMID: 26149931 DOI: 10.1007/978-3-319-17344-3_8] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Apolipoproteins are protein constituents of lipoproteins that transport cholesterol and fat in circulation and are central to cardiovascular health and disease. Soluble apolipoproteins can transiently dissociate from the lipoprotein surface in a labile free form that can misfold, potentially leading to amyloid disease. Misfolding of apoA-I, apoA-II, and serum amyloid A (SAA) causes systemic amyloidoses, apoE4 is a critical risk factor in Alzheimer's disease, and apolipoprotein misfolding is also implicated in cardiovascular disease. To explain why apolipoproteins are over-represented in amyloidoses, it was proposed that the amphipathic α-helices, which form the lipid surface-binding motif in this protein family, have high amyloid-forming propensity. Here, we use 12 sequence-based bioinformatics approaches to assess amyloid-forming potential of human apolipoproteins and to identify segments that are likely to initiate β-aggregation. Mapping such segments on the available atomic structures of apolipoproteins helps explain why some of them readily form amyloid while others do not. Our analysis shows that nearly all amyloidogenic segments: (i) are largely hydrophobic, (ii) are located in the lipid-binding amphipathic α-helices in the native structures of soluble apolipoproteins, (iii) are predicted in both native α-helices and β-sheets in the insoluble apoB, and (iv) are predicted to form parallel in-register β-sheet in amyloid. Most of these predictions have been verified experimentally for apoC-II, apoA-I, apoA-II and SAA. Surprisingly, the rank order of the amino acid sequence propensity to form amyloid (apoB>apoA-II>apoC-II≥apoA-I, apoC-III, SAA, apoC-I>apoA-IV, apoA-V, apoE) does not correlate with the proteins' involvement in amyloidosis. Rather, it correlates directly with the strength of the protein-lipid association, which increases with increasing protein hydrophobicity. Therefore, the lipid surface-binding function and the amyloid-forming propensity are both rooted in apolipoproteins' hydrophobicity, suggesting that functional constraints make it difficult to completely eliminate pathogenic apolipoprotein misfolding. We propose that apolipoproteins have evolved protective mechanisms against misfolding, such as the sequestration of the amyloidogenic segments via the native protein-lipid and protein-protein interactions involving amphipathic α-helices and, in case of apoB, β-sheets.
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26
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Shou W, Wang Y, Xie F, Wang B, Yang L, Wu H, Wang Y, Wang Z, Shi J, Huang W. A functional polymorphism affecting the APOA5 gene expression is causally associated with plasma triglyceride levels conferring coronary atherosclerosis risk in Han Chinese Population. Biochim Biophys Acta Mol Basis Dis 2014; 1842:2147-54. [DOI: 10.1016/j.bbadis.2014.08.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Revised: 07/29/2014] [Accepted: 08/13/2014] [Indexed: 01/21/2023]
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27
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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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28
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Halalkhor S, Jalali F, Tilaki KH, Shojaei S. Association of two common polymorphisms of apolipoprotein A5 gene with metabolic syndrome indicators in a North Iranian population, a cross-sectional study. J Diabetes Metab Disord 2014; 13:48. [PMID: 24708648 PMCID: PMC4030732 DOI: 10.1186/2251-6581-13-48] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/26/2013] [Accepted: 03/13/2014] [Indexed: 12/03/2022]
Abstract
Background Metabolic syndrome is an obesity dependent disorder with a worldwide high prevalence. Regarding the high prevalence of Metabolic syndrome in Iran we analyzed the influence of -1131T>C (rs662799) and c.56C>G (S19W, rs3135506) polymorphisms of the novel apolipoprotein gene, ApoA5, on some Metabolic Syndrome indicators in population from north of Iran. Methods 199 volunteers from Babol city-Iran were divided in two groups of low (N = 99, TG ≤ 103 mg/dl) and high (N = 100, TG ≥ 150 mg/dl) serum levels of Triglycerides (TG). We amplified the gene fragments containing -1131T>C and c.56C>G polymorphisms by PCR method and revealed the polymorphisms by RFLP analysis. Results We found a significant association (p = 0.016, Independent t-test) between high levels of TG and -1131T>C polymorphism but not between this polymorphism and serum HDL-C concentrations. Carriers of the C allele had a 1.97 times higher odds ratio to be in the high-TG group than those of the TT genotype (95%, CI = 1.05-3.68). We observed no association between -1131T>C polymorphism with either Waist-to-Hip Ratio (WHR) or Body-Mass-Index (BMI). In the case of c.56C>G polymorphism, although it showed a significant relationship with WHR (p = 0/040, Independent t-test), but failed to correlate with either levels of TG (p = 0.594) or HDL-C (p = 0.640) in serum. Conclusion Our study confirms that ApoA5 gene polymorphisms, -1131T>C and c.56C>G are associated with the two criteria of Metabolic Syndrome, TG and WHR, respectively.
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Affiliation(s)
- Sohrab Halalkhor
- Department of Biochemistry and Biophysics, School of Medicine, Babol University of Medical Sciences, Babol, Iran
| | - Farzad Jalali
- Department of Cardiology, School of Medicine, Babol University of Medical Sciences, Babol, Iran
| | - Karimollah Hajian Tilaki
- Department of Social Medicine, School of Medicine, Babol University of Medical Sciences, Babol, Iran
| | - Shahla Shojaei
- Department of Biochemistry, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
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Albers K, Schlein C, Wenner K, Lohse P, Bartelt A, Heeren J, Santer R, Merkel M. Homozygosity for a partial deletion of apoprotein A-V signal peptide results in intracellular missorting of the protein and chylomicronemia in a breast-fed infant. Atherosclerosis 2014; 233:97-103. [DOI: 10.1016/j.atherosclerosis.2013.12.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2010] [Revised: 11/29/2013] [Accepted: 12/01/2013] [Indexed: 10/25/2022]
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30
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Fathy MM, Wahab AAA, Tabozada S, Ibrahim M, Aref W, Hamid MAA. Association of apolipoprotein A5 gene 1131T/C polymorphism with dyslipidemia and insulin resistance in Egyptian patients with metabolic syndrome. COMPARATIVE CLINICAL PATHOLOGY 2013; 22:1245-1250. [DOI: 10.1007/s00580-012-1558-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
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31
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van den Berg SAA, Heemskerk MM, Geerling JJ, van Klinken JB, Schaap FG, Bijland S, Berbée JFP, van Harmelen VJA, Pronk ACM, Schreurs M, Havekes LM, Rensen PCN, van Dijk KW. Apolipoprotein A5 deficiency aggravates high-fat diet-induced obesity due to impaired central regulation of food intake. FASEB J 2013; 27:3354-62. [PMID: 23650188 DOI: 10.1096/fj.12-225367] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Mutations in apolipoprotein A5 (APOA5) have been associated with hypertriglyceridemia in humans and mice. This has been attributed to a stimulating role for APOA5 in lipoprotein lipase-mediated triglyceride hydrolysis and hepatic clearance of lipoprotein remnant particles. However, because of the low APOA5 plasma abundance, we investigated an additional signaling role for APOA5 in high-fat diet (HFD)-induced obesity. Wild-type (WT) and Apoa5(-/-) mice fed a chow diet showed no difference in body weight or 24-h food intake (Apoa5(-/-), 4.5±0.6 g; WT, 4.2±0.5 g), while Apoa5(-/-) mice fed an HFD ate more in 24 h (Apoa5(-/-), 2.8±0.4 g; WT, 2.5±0.3 g, P<0.05) and became more obese than WT mice. Also, intravenous injection of APOA5-loaded VLDL-like particles lowered food intake (VLDL control, 0.26±0.04 g; VLDL+APOA5, 0.11±0.07 g, P<0.01). In addition, the HFD-induced hyperphagia of Apoa5(-/-) mice was prevented by adenovirus-mediated hepatic overexpression of APOA5. Finally, intracerebroventricular injection of APOA5 reduced food intake compared to injection of the same mouse with artificial cerebral spinal fluid (0.40±0.11 g; APOA5, 0.23±0.08 g, P<0.01). These data indicate that the increased HFD-induced obesity of Apoa5(-/-) mice as compared to WT mice is at least partly explained by hyperphagia and that APOA5 plays a role in the central regulation of food intake.
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Abstract
PURPOSE OF REVIEW Apolipoprotein (apo) A-V functions to modulate intracellular and extracellular triacylglycerol metabolism. The present review addresses molecular mechanisms underlying these effects. The relevance of apoA-V to human disease conditions is illustrated by the strong correlation between single nucleotide polymorphisms in APOA5, elevated plasma triacylglycerol and dyslipidemic disease. RECENT FINDINGS Despite undergoing processing for secretion from hepatocytes, a portion of apoA-V escapes this destiny and accumulates as a component of cytosolic lipid droplets. Expression of recombinant apoA-V in hepatocarcinoma cells results in increased lipid droplet size and number at the expense of triacylglycerol secretion.ApoA-V modulates atherosclerosis in hypercholesterolemic apoE null mice. ApoE null/human apoA-V transgenic mice had reduced levels of triacylglycerol and cholesterol in plasma along with decreased aortic lesion size. SUMMARY ApoA-V modulates triacylglycerol metabolic fate. Following its synthesis, apoA-V enters the endoplasmic reticulum and associates with membrane defects created by triacylglycerol accumulation. Association of apoA-V with endoplasmic reticulum membrane defects promotes nascent lipid droplets budding toward the cytosol. Despite its low concentration in plasma (∼150 ng/ml), apoA-V modulates lipoprotein metabolism by binding to glycosylphosphatidylinositol-anchored high-density lipoprotein binding protein 1. This interaction effectively localizes triacylglycerol-rich lipoproteins in the vicinity of glycosylphosphatidylinositol-anchored high-density lipoprotein binding protein1's other ligand, lipoprotein lipase.
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Affiliation(s)
- Vineeta Sharma
- Children's Hospital Oakland Research Institute, Oakland, CA 94609, USA
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33
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Zheng XY, Zhao SP, Yan H. The role of apolipoprotein A5 in obesity and the metabolic syndrome. Biol Rev Camb Philos Soc 2012; 88:490-8. [PMID: 23279260 DOI: 10.1111/brv.12005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2012] [Revised: 11/10/2012] [Accepted: 11/20/2012] [Indexed: 12/17/2022]
Affiliation(s)
- Xiao-Yan Zheng
- Department of Cardiology; The Second Xiangya Hospital, Central South University; Changsha; 410011; China
| | - Shui-Ping Zhao
- Department of Cardiology; The Second Xiangya Hospital, Central South University; Changsha; 410011; China
| | - Hu Yan
- Institute of Mental Health; The Second Xiangya Hospital, Central South University; Changsha; 410011; China
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Nutrigenomics: a case for the common soil between cardiovascular disease and cancer. GENES AND NUTRITION 2012; 3:19-24. [PMID: 18850195 DOI: 10.1007/s12263-008-0079-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The border between health and disease is often set by a complex equilibrium between two elements, genetics on one hand, lifestyle on the other, To know it better, means to give new weapons, often crucial, in the hands of the doctors and their patients. It also means to adjust therapies, to find out which drug is good for a patient and which prevention strategy will work better for him/her. Nutrigenomics is an approach to individualize or personalize food and nutrition, and ultimately health, by tailoring the food to the individual genotype. In this review, we present the interaction between certain genetic polymorphisms and diet and increased cardiovascular or cancer risk. It is, indeed, now clear that a large number of bioactive food components may provide risk or protection at several stages of both atherosclerosis and cancer formation processes. We are giving here few examples of gene-food interactions relevant for both the risk of cardiovascular disease and cancer, since a common soil could exist in the genesis of cardiovascular disease and of some types of cancer (mainly gastrointestinal tract and hormone-dependent).
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Garelnabi M, Lor K, Jin J, Chai F, Santanam N. The paradox of ApoA5 modulation of triglycerides: evidence from clinical and basic research. Clin Biochem 2012; 46:12-9. [PMID: 23000317 DOI: 10.1016/j.clinbiochem.2012.09.007] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2012] [Revised: 08/13/2012] [Accepted: 09/10/2012] [Indexed: 01/02/2023]
Abstract
UNLABELLED Apolipoprotein A5 (ApoA5) is a key regulator of plasma triglycerides (TG), even though its plasma concentration is very low compared to other known apoproteins. Over the years, researchers have attempted to elucidate the molecular mechanisms by which ApoA5 regulates plasma TG in vivo. Though still under debate, two theories broadly describe how ApoA5 modulates TG levels: (i) ApoA5 enhances the catabolism of TG-rich lipoproteins and (ii) it inhibits the rate of production of very low-density lipoprotein (VLDL), the major carrier of TGs. This review will summarize the basic and clinical studies that describe the importance of ApoA5 in TG metabolism. Population studies conducted in various countries have demonstrated an association between single nucleotide polymorphisms (SNPs) in ApoA5 and the increased risk to cardiovascular disease and metabolic syndrome (including diabetes and obesity). ApoA5 is also highly expressed during liver regeneration and is an acute phase protein associated with HDL, which is independent of its effects on TG metabolism. CONCLUSION Despite considerable evidences available from clinical and basic research studies on the role of ApoA5 in TG metabolism and its indirect link to metabolic diseases, additional investigations are needed to understand the paradoxical role of this important apoprotein is modulated by both diet and its polymorphism variants.
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Affiliation(s)
- Mahdi Garelnabi
- Department of Clinical Laboratory and Nutritional Sciences, University of Massachusetts Lowell, MA 01854, USA.
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Gao X, Forte TM, Ryan RO. Influence of apolipoprotein A-V on hepatocyte lipid droplet formation. Biochem Biophys Res Commun 2012; 427:361-5. [PMID: 23000161 DOI: 10.1016/j.bbrc.2012.09.065] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2012] [Accepted: 09/11/2012] [Indexed: 11/30/2022]
Abstract
Apolipoprotein A-V (apoA-V) is postulated to modulate intra-hepatic triglyceride (TG) trafficking. Stably transfected McA-RH7777 hepatocarcinoma cells expressing human apoA-V displayed enhanced neutral lipid staining while conditioned media from these cells had 40±8% less TG than cells transfected with a control vector. To obtain homogeneous cell lines expressing different amounts of apoA-V, a strategy of clonal selection was pursued. Immunoblot analysis of two distinct apoA-V stable cell lines yielded one that expresses low amounts of apoA-V and another that expresses higher amounts. Confocal fluorescence microscopy of control cells and cells expressing low levels of apoA-V had similar numbers of lipid droplets while cells expressing higher amounts of apoA-V had twice as many lipid droplets, on average. Thus, apoA-V expression promotes lipid droplet accumulation in these cells.
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Affiliation(s)
- Xuan Gao
- Children's Hospital Oakland Research Institute, 5700 Martin Luther King Jr. Way, Oakland, CA 94609, USA
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Guardiola M, Alvaro A, Vallvé JC, Rosales R, Solà R, Girona J, Serra N, Duran P, Esteve E, Masana L, Ribalta J. APOA5 gene expression in the human intestinal tissue and its response to in vitro exposure to fatty acid and fibrate. Nutr Metab Cardiovasc Dis 2012; 22:756-762. [PMID: 21489765 DOI: 10.1016/j.numecd.2010.12.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2010] [Revised: 10/05/2010] [Accepted: 12/11/2010] [Indexed: 01/11/2023]
Abstract
BACKGROUND AND AIMS APOA5, a key gene regulating triglyceride (TG) levels, is reported to be expressed exclusively in the liver where it may regulate TG-rich particle synthesis and secretion. Since the same lipoprotein processing occurs in the intestine, we have postulated that this organ would also express APOA5. METHODS AND RESULTS We have detected the APOA5 gene expression in C57BL/6J mouse and in human small intestine samples. In humans, it is expressed mainly in the duodenum and colon, with messenger RNA (mRNA) levels four orders of magnitude lower than in the liver, and the protein product being one-sixth of the liver equivalent. Subsequently, we carried out in vitro experiments in TC-7/CaCo(2) human intestinal cells to analyse the expression of APOA5, APOC3, APOB and MTP genes after the incubation with long- and short-chain fatty acids, and a peroxisome proliferator-activated receptor alpha (PPARα) agonist (Wy 14643, a fibrate therapeutic agent). In the TC-7 cell line, APOA5 expression was significantly upregulated by saturated fatty acids. The short-chain fatty acid butyrate increased APOA5 expression almost fourfold while APOB was downregulated by increasing butyrate concentrations. When TC-7 cells were incubated with PPARα agonist, the APOA5 expression was increased by 60%, while the expression of APOB, MTP and APOC3 was decreased by 50%, 30% and 45%, respectively. CONCLUSION Our results demonstrate that APOA5 is expressed in the intestine, albeit at a much lower concentration than in the liver. While it remains to be determined whether intestinal apo A-V is functional, our in vitro experiments show that its expression is modifiable by dietary and pharmacological stimuli.
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Affiliation(s)
- M Guardiola
- Unitat de Recerca en Lípids i Arteriosclerosi, Institut d'Investigacions Sanitàries Pere, Virgili, Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas, Universitat Rovira i Virgili, Reus, Spain
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Liu CF, Yang QF, Chen XL, Liu CY. Apolipoprotein a5 gene polymorphism and risk for metabolic syndrome: a meta-analysis. Genet Test Mol Biomarkers 2012; 16:1241-5. [PMID: 22905904 DOI: 10.1089/gtmb.2012.0183] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
BACKGROUND Many studies have focused on the association between the apolipoprotein A5 (ApoA5) polymorphism and the risk of metabolic syndrome (MetS). However, these studies drew inconsistent conclusions. The aim of this study was to evaluate the exact association between the ApoA5 polymorphism and MetS in a large-scale meta-analysis. METHODS The PubMed, Embase, and Science Citation Index (ISI Web of Science) databases were searched to collect all publications on the association between the ApoA5 polymorphism and MetS. Two common variants of ApoA5 (namely -1131T>C in the promoter region and c.56C>G in the coding region) with the risk of MetS were analyzed. The overall odd ratios (ORs) and 95% confidence intervals (CIs) for -1131T>C (CC+TC) versus TT genotype and c.C56G (GG+GC) versus CC were assessed between the MetS and control group. Subgroup analysis was further performed by ethnicity. The meta-analysis was performed by Stata11.0. RESULTS Twelve studies from 10 publications were chosen in our meta-analysis. The combined results showed that C allele carriers (CC+TC) of -1131T>C had a significantly higher risk of MetS for the overall (OR=1.32; 95% CI: 1.14-1.53; p=0.000) with moderate heterogeneity (I2=54.9%, p=0.014). Subgroup analysis was further performed according to ethnicity, and the association was still significant in Asians (OR=1.42; 95% CI: 1.25-1.62; p=0.000), but not in white populations (OR=1.25; 95% CI: 0.97-1.61; p=0.087). When analyzing the association between c.C56G and MetS, the G allele carrier (GG+GC) genotype significantly increased the risk of MetS (OR=1.32; 95% CI: 1.15-1.50; p=0.000) in white populations. No significant publication bias was observed in either -1131T>C or c.C56G. CONCLUSIONS Our study suggested that the ApoA5 -1131T>C polymorphism was significantly associated with the risk of MetS in Asians, but not in white populations. However, the c.C56G polymorphism was significantly associated with MetS in white populations.
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Affiliation(s)
- Cun-Fei Liu
- Department of Geriatrics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, P.R. China
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Apolipoprotein A-V; a potent triglyceride reducer. Atherosclerosis 2011; 219:15-21. [DOI: 10.1016/j.atherosclerosis.2011.07.019] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2011] [Revised: 07/03/2011] [Accepted: 07/04/2011] [Indexed: 11/21/2022]
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Huang YJ, Lin YL, Chiang CI, Yen CT, Lin SW, Kao JT. Functional importance of apolipoprotein A5 185G in the activation of lipoprotein lipase. Clin Chim Acta 2011; 413:246-50. [PMID: 22008704 DOI: 10.1016/j.cca.2011.09.045] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2011] [Revised: 08/12/2011] [Accepted: 09/29/2011] [Indexed: 11/25/2022]
Abstract
BACKGROUND Apolipoprotein A5 (APOA5) over-expression enhances lipolysis of triglyceride (TG) through stimulation of lipoprotein lipase (LPL) activity; however, an APOA5 G185C variant was found associated with hypertriglyceridemia. The aim of this study was, therefore, to explore the importance of APOA5 185GG in the activation of LPL. METHODS A fragment containing mature human APOA5 cDNA was obtained by RT-PCR and subcloned into pET-15b vector. Site-directed mutagenesis was performed to generate 19 variants. Recombinant human APOA5 wild type and variants were produced in Escherichia coli, and then activation of LPL was measured. RESULTS Activity of APOA5 variants on LPL-mediated 1,2-dimyristoyl-sn-glycero-3-phosphocholine hydrolysis was reduced by 17 to 74% in comparison to wild type APOA5 (P<0.0001). All variants also showed reduced activation (P<0.0001) of LPL-mediated hydrolysis of very low-density lipoprotein (VLDL); activation abilities of APOA5 variants ranged from 31 to 81% of wild-type APOA5. CONCLUSIONS APOA5 residue 185G is very important in LPL-mediated VLDL hydrolysis, and any mutation at this residue will decrease LPL activation and concomitant TG modulation.
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Affiliation(s)
- Yi-Jan Huang
- Department of Clinical Laboratory Sciences and Medical Biotechnology, College of Medicine, National Taiwan University, Taiwan
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Maász A, Szolnoki Z, Balikó L, Melegh B. Genetics of ischemic stroke: where are we now? Orv Hetil 2011; 152:455-63. [DOI: 10.1556/oh.2011.29069] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
As stroke is the third leading cause of death after heart failure and tumors worldwide, cerebrovascular diseases reached substantial attention. In the past few years, significant progression has been seen in identification of genetic variants in the background of stroke and other cerebrovascular and cardiovascular events. Examination of these variants is a new approach to recognize pathogenesis of disorders that hopefully helps in future prevention and prospects of screening and, optimistically, it contributes to special care of patients susceptible for stroke. In the background of ischemic stroke several genetic variants have been identified, which localize in genes encoding proteins involved in hemostasis, renin-angiotensin system and lipid metabolism. The number of these variants exponentially increases permanently due to rapid spreading of genome wide association studies. The goal of this review is to summarize the results of genetic studies on ischemic stroke. Here the authors focus on genetic variants which can have major role in personalized medicine and prevention of stroke. Orv. Hetil., 2011, 152, 455–463.
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Affiliation(s)
- Anita Maász
- Pécsi Tudományegyetem, Általános Orvostudományi Kar Orvosi Genetikai Intézet Pécs Szigeti út 12. 7624
| | - Zoltán Szolnoki
- Pándy Kálmán Kórház Neurológia és Agyérbetegségek Osztály Gyula
| | - László Balikó
- Veszprém Megyei Cholnoky Ferenc Kórház Neurológiai Osztály Veszprém
| | - Béla Melegh
- Pécsi Tudományegyetem, Általános Orvostudományi Kar Orvosi Genetikai Intézet Pécs Szigeti út 12. 7624
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Haqparast S, Ramandi MF, Samadikuchaksaraei A, Pazhakh V. A Single Nucleotide Polymorphism -1131T>C in the Apolipoprotein A5 Gene Modulates the Levels of Triglyceride. Lab Med 2011. [DOI: 10.1309/lm3fqygrw64htinw] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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Blade AM, Fabritius MA, Hou L, Weinberg RB, Shelness GS. Biogenesis of apolipoprotein A-V and its impact on VLDL triglyceride secretion. J Lipid Res 2011; 52:237-44. [PMID: 21115968 PMCID: PMC3023543 DOI: 10.1194/jlr.m010793] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2010] [Revised: 11/09/2010] [Indexed: 12/12/2022] Open
Abstract
Apolipoprotein A-V (apoA-V) is a potent regulator of intravascular triglyceride (TG) metabolism, yet its plasma concentration is very low compared with that of other apolipoproteins. To examine the basis for its low plasma concentration, the secretion efficiency of apoA-V was measured in stably transfected McA-RH7777 rat hepatoma cells. Pulse-chase experiments revealed that only ∼20% of newly synthesized apoA-V is secreted into culture medium within 3 h postsynthesis and that ∼65% undergoes presecretory turnover; similar results were obtained with transfected nonhepatic Chinese hamster ovary cells. ApoA-V secreted by McA-RH7777 cells was not associated with cell surface heparin-competable binding sites. When stably transfected McA-RH7777 cells were treated with oleic acid, the resulting increase in TG synthesis caused a reduction in apoA-V secretion, a reciprocal increase in cell-associated apoA-V, and movement of apoA-V onto cytosolic lipid droplets. In a stably transfected doxycycline-inducible McA-RH7777 cell line, apoA-V expression inhibited TG secretion by ∼50%, increased cellular TG, and reduced Z-average VLDL(1) particle diameter from 81 to 67 nm; however, no impact on apoB secretion was observed. These data demonstrate that apoA-V inefficiently traffics within the secretory pathway, that its intracellular itinerary can be regulated by changes in cellular TG accumulation, and that apoA-V synthesis can modulate VLDL TG mobilization and secretion.
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Affiliation(s)
- Anna M. Blade
- Department of Pathology, Wake Forest University School of Medicine, Winston-Salem, NC 27157
| | - Melissa A. Fabritius
- Department of Pathology, Wake Forest University School of Medicine, Winston-Salem, NC 27157
| | - Li Hou
- Department of Pathology, Wake Forest University School of Medicine, Winston-Salem, NC 27157
| | - Richard B. Weinberg
- Department of Pathology, Wake Forest University School of Medicine, Winston-Salem, NC 27157
- Physiology and Pharmacology, Wake Forest University School of Medicine, Winston-Salem, NC 27157
| | - Gregory S. Shelness
- Department of Pathology, Wake Forest University School of Medicine, Winston-Salem, NC 27157
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Guardiola M, Ribalta J, Gómez-Coronado D, Lasunción MA, de Oya M, Garcés C. The apolipoprotein A5 (APOA5) gene predisposes Caucasian children to elevated triglycerides and vitamin E (Four Provinces Study). Atherosclerosis 2010; 212:543-7. [DOI: 10.1016/j.atherosclerosis.2010.07.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2010] [Revised: 06/17/2010] [Accepted: 07/05/2010] [Indexed: 01/11/2023]
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Maasz A, Melegh B. Three periods of one and a half decade of ischemic stroke susceptibility gene research: lessons we have learned. Genome Med 2010; 2:64. [PMID: 20831840 PMCID: PMC3092115 DOI: 10.1186/gm185] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Candidate gene association studies, linkage studies and genome-wide association studies have highlighted the role of genetic factors in the development of ischemic stroke. This research started over a decade ago, and can be separated into three major periods of research. In the first wave classic susceptibility markers associated with other diseases (such as the Leiden mutation in Factor V and mutations in the prothrombin and 5,10-methylenetetrahydrofolate reductase (MTHFR) genes) were tested for their role in stroke. These first studies used just a couple of hundred samples or even less. The second and still ongoing period bridges the two other periods of research and has led to a rapid increase in the spectrum of functional variants of genes or genomic regions, discovered primarily in relation to other diseases, tested on larger stroke samples of clinically better stratified patients. Large numbers of these alleles were originally discovered by array-based genome-wide association studies. The third period of research involves the direct array screening of large samples; this approach represents significant progress for research in the field. Research into susceptibility genes for stroke has taught us that careful stratification of patients is critical, that susceptibility alleles are often shared between diseases, and that not all susceptibility factors that associate with clinical traits that are themselves risk factors for stroke (such as increase of triglycerides) necessarily represent susceptibility for stroke. Research so far has been mainly focused on large- and small-vessel associated stroke, and knowledge on other types of stroke, which represent much smaller population samples, is still very scarce. Although some susceptibility allele tests are on the palette of some direct-to-consumer companies, the clinical utility and clinical validity of these test results still do not support their use in clinical practice.
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Affiliation(s)
- Anita Maasz
- Department of Medical Genetics, University of Pecs, H-7624 Pecs, Szigeti 12, Hungary.
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Park JY, Paik JK, Kim OY, Chae JS, Jang Y, Lee JH. Interactions between the APOA5 -1131T>C and the FEN1 10154G>T polymorphisms on ω6 polyunsaturated fatty acids in serum phospholipids and coronary artery disease. J Lipid Res 2010; 51:3281-8. [PMID: 20802161 DOI: 10.1194/jlr.m010330] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
We determined the contribution of the combination of FEN1 10154G>T with the most significant association in the analysis of plasma arachidonic acid (AA, 20:4ω6) and the APOA5-1131T>C on phospholipid ω6PUFA and coronary artery disease (CAD). Patients with CAD (n = 807, 27-81 years of age) and healthy controls (n = 1123) were genotyped for FEN1 10154G>T and APOA5-1131T>C. We found a significant interaction between these two genes for CAD risk (P = 0.007) adjusted for confounding factors. APOA5-1131C allele carriers had a higher CAD risk [odds ratio (OR):1.484, 95% confidence interval (CI):1.31-1.96; P = 0.005] compared with APOA5-1131TT individuals in the FEN1 10154GG genotype group but not in the FEN1 10154T allele group (OR:1.096, 95%CI:0.84-1.43; P = 0.504). Significant interactions between these two genes were also observed for the AA proportion (P = 0.04) and the ratio of AA/linoleic acid (LA, 18:2ω6) (P = 0.004) in serum phospholipids of controls. The APOA5-1131C allele was associated with lower AA (P = 0.027) and AA/LA (P = 0.014) only in controls carrying the FEN1 10154T allele. In conclusion, the interaction between these genes suggests that the FEN1 10154T variant allele decreases AA and AA/LA in the serum phospholipids of carriers of the APOA5-1131C allele, but contributes no significant increase in CAD risk for this population subset despite their increased triglylcerides and decreased apoA5.
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Affiliation(s)
- Ju Yeon Park
- National Research Laboratory of Clinical Nutrigenetics/Nutrigenomics, Department of Food and Nutrition, College of Human Ecology, Yonsei University, Seoul, Korea
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Delgado-Lista J, Perez-Jimenez F, Ruano J, Perez-Martinez P, Fuentes F, Criado-Garcia J, Parnell LD, Garcia-Rios A, Ordovas JM, Lopez-Miranda J. Effects of variations in the APOA1/C3/A4/A5 gene cluster on different parameters of postprandial lipid metabolism in healthy young men. J Lipid Res 2010; 51:63-73. [PMID: 19592705 DOI: 10.1194/jlr.m800527-jlr200] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The APOA1/C3/A4/A5 gene cluster encodes important regulators of fasting lipids, but the majority of lipid metabolism takes place in the postprandial state and knowledge about gene regulation in this state is scarce. With the aim of characterizing possible regulators of lipid metabolism, we studied the effects of nine single nucleotide polymorphisms (SNPs) during postprandial lipid metabolism. Eighty-eight healthy young men were genotyped for APOA1 -2630 (rs613808), APOA1 -2803 (rs2727784), APOA1 -3012 (rs11216158), APOC3 -640 (rs2542052), APOC3 -2886 (rs2542051), APOC3 G34G (rs4520), APOA4 N147S (rs5104), APOA4 T29T (rs5092), and A4A5_inter (rs1263177) and were fed a saturated fatty acid-rich meal (1g fat/kg of weight with 60% fat, 15% protein and 25% carbohydrate). Serial blood samples were extracted for 11 h after the meal. Total cholesterol and fractions [HDL-cholesterol, LDL-cholesterol, trifacylglycerols (TGs) in plasma, TG-rich lipoproteins (TRLs) (large TRLs and small TRLs), apolipoprotein A-I and apolipoprotein B] were determined. APOA1 -2803 homozygotes for the minor allele and A4A5_inter carriers showed a limited degree of postprandial lipemia. Carriers of the rare alleles of APOA4 N147S and APOA4 T29T had lower APOA1 plasma concentration during this state. APOC3 -640 was associated with altered TG kinetics but not its magnitude. We have identified new associations between SNPs in the APOA1/C3/A4/A5 gene cluster and altered postprandial lipid metabolism.
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Affiliation(s)
- Javier Delgado-Lista
- Lipids and Atherosclerosis Research Unit, Reina Sofía University Hospital, Instituto Maimonides de Investigación Biomedica de Cordoba (IMIBIC), University of Cordoba, Ciber Fisiopatología Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, CordobaSpain
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Shu X, Nelbach L, Ryan RO, Forte TM. Apolipoprotein A-V associates with intrahepatic lipid droplets and influences triglyceride accumulation. Biochim Biophys Acta Mol Cell Biol Lipids 2010; 1801:605-8. [PMID: 20153840 DOI: 10.1016/j.bbalip.2010.02.004] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2009] [Revised: 02/01/2010] [Accepted: 02/03/2010] [Indexed: 11/24/2022]
Abstract
Apolipoprotein A-V (apoA-V), secreted solely by the liver, is a low abundance protein that strongly influences plasma triglyceride (TG) levels. In vitro, in transfected hepatoma cell lines apoA-V is largely retained within the cell in association with cytosolic lipid droplets (LD). To evaluate if this is true in vivo, in the present study the amount of apoA-V in the plasma compartment versus liver tissue was determined in APOA5 transgenic (Tg) mice. The majority of total apoA-V ( approximately 80%) was in the plasma compartment. Injection of APOA5 Tg mice with heparin increased plasma apoA-V protein levels by approximately 25% indicating the existence of a heparin-releasable pool. Intrahepatic apoA-V was associated with LD isolated from livers of wild type (WT) and APOA5 Tg mice. Furthermore, livers from APOA5 Tg mice contained significantly higher amounts of TG than livers from WT or apoa5 knockout mice suggesting that apoA-V influences intrahepatic TG levels.
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Affiliation(s)
- Xiao Shu
- Center for Prevention of Obesity, Diabetes and Cardiovascular Disease, Children's Hospital Oakland Research Institute, Oakland, CA 94609, USA
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Smith CE, Tucker KL, Lai CQ, Parnell LD, Lee YC, Ordovás JM. Apolipoprotein A5 and lipoprotein lipase interact to modulate anthropometric measures in Hispanics of Caribbean origin. Obesity (Silver Spring) 2010; 18:327-32. [PMID: 19629056 PMCID: PMC2813926 DOI: 10.1038/oby.2009.216] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Apolipoprotein A5 (APOA5) and lipoprotein lipase (LPL) proteins interact functionally to regulate lipid metabolism, and single-nucleotide polymorphisms (SNPs) for each gene have also been associated independently with obesity risk. Evaluating gene combinations may be more effective than single SNP analyses in identifying genetic risk, but insufficient minor allele frequency (MAF) often limits evaluations of potential epistatic relationships. Populations with multiple ancestral admixtures may provide unique opportunities for evaluating genetic interactions. We examined relationships between LPL m107 (rs1800590) and APOA5 S19W (rs3135506) and lipid and anthropometric measures in Caribbean origin Hispanics (n = 1,019, aged 45-75 years) living in the Boston metropolitan area. Significant interaction terms between LPL m107 and APOA5 S19W were observed for BMI (P = 0.003) and waist circumference (P = 0.019). Higher BMI (P = 0.001), waist (P = 0.011) and hip (P = 0.026) circumference were observed in minor allele (G) carriers for LPL m107 who also carried the APOA5 S19W minor allele (G). Additionally, extreme obesity (BMI > or = 40 kg/m(2)) risk was higher (odds ratio = 4.02; 95% confidence interval: 1.81-8.91; global P = 0.008) for minor allele carriers for both SNPs (LPL TG+GG, APOA5 CG+GG) compared to major allele carriers for both SNPs. In summary, we identified significant interactions for APOA5 S19W and LPL m107 for obesity in Caribbean Hispanics. Population-specific MAFs increase the difficulties of replicating gene-gene interactions, but may support the hypothesis that combinations of frequencies in selected genes could heighten obesity susceptibility in a given population. Analyses of gene-gene interactions may improve understanding of genetically based obesity risk, and underscore the need for further study of groups with multiple ancestral admixtures.
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Affiliation(s)
- Caren E. Smith
- Jean Mayer US Department of Agriculture Human Nutrition Research Center on Aging at Tufts University, Boston, MA
| | - Katherine L. Tucker
- Jean Mayer US Department of Agriculture Human Nutrition Research Center on Aging at Tufts University, Boston, MA
| | - Chao-Qiang Lai
- Jean Mayer US Department of Agriculture Human Nutrition Research Center on Aging at Tufts University, Boston, MA
| | - Laurence D. Parnell
- Jean Mayer US Department of Agriculture Human Nutrition Research Center on Aging at Tufts University, Boston, MA
| | - Yu-Chi Lee
- Jean Mayer US Department of Agriculture Human Nutrition Research Center on Aging at Tufts University, Boston, MA
| | - José M. Ordovás
- Jean Mayer US Department of Agriculture Human Nutrition Research Center on Aging at Tufts University, Boston, MA
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