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Miao G, Zhuo D, Han X, Yao W, Liu C, Liu H, Cao H, Sun Y, Chen Z, Feng T. From degenerative disease to malignant tumors: Insight to the function of ApoE. Biomed Pharmacother 2023; 158:114127. [PMID: 36516696 DOI: 10.1016/j.biopha.2022.114127] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 12/03/2022] [Accepted: 12/09/2022] [Indexed: 12/14/2022] Open
Abstract
Apolipoprotein E (ApoE) is a multifunctional protein involved in lipid transport and lipoprotein metabolism, mediating lipid distribution/redistribution in tissues and cells. It can also regulate inflammation and immune function, maintain cytoskeleton stability, and improve neural tissue Function. Due to genetic polymorphisms of ApoE (ε2, ε3, and ε4), its three common structural isoforms (ApoE2, ApoE3, ApoE4) are also associated with the risk of many diseases, especially degenerative diseases, such as vascular degenerative diseases including atherosclerosis (AS), coronary heart disease (CHD), and neurodegenerative disease like Alzheimer's disease (AD). The frequency of the ε4 allele and APOE variants were significantly higher than that of the ε2 and ε3 alleles in the patients with CHD or AD. In recent years, ApoE has frequently appeared in tumor research and become a tumor biomarker gradually. It has been found that ApoE is highly expressed in most solid tumor tissues, such as glioblastoma, gastric cancer, pancreatic ductal cell carcinoma, etc. Studies illustrated that ApoE could regulate the polarization changes of macrophages, participate in the construction of tumor immune microenvironment, regulate tumor inflammation and immune response and play a role in tumor progression, invasion, and metastasis. Of course, many functions of ApoE and its relationship with diseases are still under research. By reviewing the structure and function of ApoE from degeneration diseases to tumor neoplasms, we hope to better understand such a biomarker and further explore the value of ApoE in later studies.
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Affiliation(s)
- Ganggang Miao
- Department of General Surgery, The People's Hospital of Danyang, Affiliated Danyang Hospital of Nantong University, Danyang, Jiangsu, China; Department of General Surgery, The Affiliated Nanjing Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Danping Zhuo
- First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Xue Han
- Department of Clinical Laboratory, the Affiliated Hospital of Qingdao University, Qingdao, Shangdong, China
| | - Wentao Yao
- Department of Urology, Suzhou TCM Hospital Affiliated to Nanjing University of Chinese Medicine, Suzhou, Jiangsu, China
| | - Chuan Liu
- Hepatobiliary/Liver Transplantation Center, The First Affiliated Hospital of Nanjing Medical University, Key Laboratory of Living Donor Transplantation, Chinese Academy of Medical Sciences, Nanjing, China
| | - Hanyuan Liu
- Department of General Surgery, The Affiliated Nanjing Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Hongyong Cao
- Department of General Surgery, The Affiliated Nanjing Hospital of Nanjing Medical University, Nanjing, Jiangsu, China.
| | - Yangbai Sun
- Department of Musculoskeletal Surgery, Fudan University Shanghai Cancer Center, Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China.
| | - Zhiqiang Chen
- Department of Nuclear Medicine, The First Affiliated Hospital of Soochow University, Suzhou, China.
| | - Tingting Feng
- Jiangsu Key Laboratory of Infection and Immunity, Institute of Biology and Medical Sciences, Soochow University, Suzhou, China.
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Heidemann BE, Koopal C, Baass A, Defesche JC, Zuurbier L, Mulder MT, Roeters van Lennep JE, Riksen NP, Boot C, Marais AD, Visseren FLJ. Establishing the relationship between Familial Dysbetalipoproteinemia and genetic variants in the APOE gene. Clin Genet 2022; 102:253-261. [PMID: 35781703 PMCID: PMC9543580 DOI: 10.1111/cge.14185] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 06/27/2022] [Accepted: 06/28/2022] [Indexed: 11/30/2022]
Abstract
Familial Dysbetalipoproteinemia (FD) is the second most common monogenic dyslipidemia and is associated with a very high cardiovascular risk due to cholesterol‐enriched remnant lipoproteins. FD is usually caused by a recessively inherited variant in the APOE gene (ε2ε2), but variants with dominant inheritance have also been described. The typical dysbetalipoproteinemia phenotype has a delayed onset and requires a metabolic hit. Therefore, the diagnosis of FD should be made by demonstrating both the genotype and dysbetalipoproteinemia phenotype. Next Generation Sequencing is becoming more widely available and can reveal variants in the APOE gene for which the relation with FD is unknown or uncertain. In this article, two approaches are presented to ascertain the relationship of a new variant in the APOE gene with FD. The comprehensive approach consists of determining the pathogenicity of the variant and its causal relationship with FD by confirming a dysbetalipoproteinemia phenotype, and performing in vitro functional tests and, optionally, in vivo postprandial clearance studies. When this is not feasible, a second, pragmatic approach within reach of clinical practice can be followed for individual patients to make decisions on treatment, follow‐up, and family counseling.
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Affiliation(s)
- Britt E Heidemann
- Department of Vascular Medicine, University Medical Center Utrecht, Utrecht University, The Netherlands
| | - Charlotte Koopal
- Department of Vascular Medicine, University Medical Center Utrecht, Utrecht University, The Netherlands
| | - Alexis Baass
- Genetic Dyslipidemias Clinic of the Montreal Clinical Research Institute, Québec, Canada; Department of Medicine, Divisions of Experimental Medicine and Medical Biochemistry, McGill University, Québec, Canada
| | - Joep C Defesche
- Department of Human Genetics, Amsterdam University Medical Centers, University of Amsterdam, Netherlands
| | - Linda Zuurbier
- Department of Human Genetics, Amsterdam University Medical Centers, University of Amsterdam, Netherlands
| | - Monique T Mulder
- Department of Internal Medicine, Erasmus University Medical Center, Rotterdam, Netherlands
| | | | - Niels P Riksen
- Department of Internal Medicine and Research Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Christopher Boot
- Department of Blood Sciences, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | - A David Marais
- Division of Chemical Pathology, Department of Pathology, Faculty of Health Sciences, University of Cape Town, South Africa; Cape Town, South Africa
| | - Frank L J Visseren
- Department of Vascular Medicine, University Medical Center Utrecht, Utrecht University, The Netherlands
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3
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Khalil YA, Rabès JP, Boileau C, Varret M. APOE gene variants in primary dyslipidemia. Atherosclerosis 2021; 328:11-22. [PMID: 34058468 DOI: 10.1016/j.atherosclerosis.2021.05.007] [Citation(s) in RCA: 59] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 04/30/2021] [Accepted: 05/12/2021] [Indexed: 01/10/2023]
Abstract
Apolipoprotein E (apoE) is a major apolipoprotein involved in lipoprotein metabolism. It is a polymorphic protein and different isoforms are associated with variations in lipid and lipoprotein levels and thus cardiovascular risk. The isoform apoE4 is associated with an increase in LDL-cholesterol levels and thus a higher cardiovascular risk compared to apoE3. Whereas, apoE2 is associated with a mild decrease in LDL-cholesterol levels. In the presence of other risk factors, apoE2 homozygotes could develop type III hyperlipoproteinemia (familial dysbetalipoproteinemia or FD), an atherogenic disorder characterized by an accumulation of remnants of triglyceride-rich lipoproteins. Several rare APOE gene variants were reported in different types of dyslipidemias including FD, familial combined hyperlipidemia (FCH), lipoprotein glomerulopathy and bona fide autosomal dominant hypercholesterolemia (ADH). ADH is characterized by elevated LDL-cholesterol levels leading to coronary heart disease, and due to molecular alterations in three main genes: LDLR, APOB and PCSK9. The identification of the APOE-p.Leu167del variant as the causative molecular element in two different ADH families, paved the way to considering APOE as a candidate gene for ADH. Due to non mendelian interacting factors, common genetic and environmental factors and perhaps epigenetics, clinical presentation of lipid disorders associated with APOE variants often strongly overlap. More studies are needed to determine the spectrum of APOE implication in each of the diseases, notably ADH, in order to improve clinical and genetic diagnosis, prognosis and patient management. The purpose of this review is to comment on these APOE variants and on the molecular and clinical overlaps between dyslipidemias.
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Affiliation(s)
- Yara Abou Khalil
- Laboratory for Vascular Translational Science (LVTS), INSERM U1148, Centre Hospitalo-Universitaire Xavier Bichat, Paris, France; Université de Paris, Paris, France; Laboratory of Biochemistry and Molecular Therapeutics (LBTM), Faculty of Pharmacy, Pôle Technologie- Santé (PTS), Saint-Joseph University, Beirut, Lebanon
| | - Jean-Pierre Rabès
- Laboratory for Vascular Translational Science (LVTS), INSERM U1148, Centre Hospitalo-Universitaire Xavier Bichat, Paris, France; Laboratory of Biochemistry and Molecular Genetics, Centre Hospitalo-Universitaire Ambroise Paré, HUPIFO, AP-HP. Paris-Saclay, Boulogne-Billancourt, France; UFR Simone Veil-Santé, UVSQ, Montigny-Le-Bretonneux, France
| | - Catherine Boileau
- Laboratory for Vascular Translational Science (LVTS), INSERM U1148, Centre Hospitalo-Universitaire Xavier Bichat, Paris, France; Université de Paris, Paris, France; Genetics Department, AP-HP, CHU Xavier Bichat, Paris, France
| | - Mathilde Varret
- Laboratory for Vascular Translational Science (LVTS), INSERM U1148, Centre Hospitalo-Universitaire Xavier Bichat, Paris, France; Université de Paris, Paris, France.
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4
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Boot CS, Luvai A, Neely RDG. The clinical and laboratory investigation of dysbetalipoproteinemia. Crit Rev Clin Lab Sci 2020; 57:458-469. [PMID: 32255405 DOI: 10.1080/10408363.2020.1745142] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Familial dysbetalipoproteinemia (type III hyperlipoproteinemia) is a potentially underdiagnosed inherited dyslipidemia associated with greatly increased risk of coronary and peripheral vascular disease. The mixed hyperlipidemia observed in this disorder usually responds well to appropriate medical therapy and lifestyle modification. Although there are characteristic clinical features such as palmar and tuberous xanthomata, associated with dysbetalipoproteinemia, they are not always present, and their absence cannot be used to exclude the disorder. The routine lipid profile cannot distinguish dysbetalipoproteinemia from other causes of mixed hyperlipidemia and so additional investigations are required for confident diagnosis or exclusion. A range of investigations that have been proposed as potential diagnostic tests are discussed in this review, but the definitive biochemical test for dysbetalipoproteinemia is widely considered to be beta quantification. Beta quantification can determine the presence of "β-VLDL" in the supernatant following ultracentrifugation and whether the VLDL cholesterol to triglyceride ratio is elevated. Both features are considered hallmarks of the disease. However, beta quantification and other specialist tests are not widely available and are not high-throughput tests that can practically be applied to all patients with mixed hyperlipidemia. Using apolipoprotein B (as a ratio either to total or non-HDL cholesterol or as part of a multi-step algorithm) as an initial test to select patients for further investigation is a promising approach. Several studies have demonstrated a high degree of diagnostic sensitivity and specificity using these approaches and apolipoprotein B is a relatively low-cost test that is widely available on high-throughput platforms. Genetic testing is also important in the diagnosis, but it should be noted that most individuals with an E2/2 genotype do not suffer from remnant hyperlipidemia and around 10% of familial dysbetalipoproteinemia cases are caused by rarer, autosomal dominant mutations in APOE that will only be detected if the gene is fully sequenced. Wider implementation of diagnostic pathways utilizing apo B could lead to more rational use of specialist investigations and more consistent detection of patients with dysbetalipoproteinemia. Without the application of a consistent evidence-based approach to identifying dysbetalipoproteinemia, many cases are likely to remain undiagnosed.
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Affiliation(s)
- Christopher S Boot
- Department of Blood Sciences, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | - Ahai Luvai
- Department of Blood Sciences, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | - Robert D G Neely
- Department of Blood Sciences, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
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5
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Autosomal dominant familial dysbetalipoproteinemia: A pathophysiological framework and practical approach to diagnosis and therapy. J Clin Lipidol 2017; 11:12-23.e1. [DOI: 10.1016/j.jacl.2016.10.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Revised: 08/26/2016] [Accepted: 10/02/2016] [Indexed: 11/18/2022]
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6
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Update on the molecular biology of dyslipidemias. Clin Chim Acta 2016; 454:143-85. [DOI: 10.1016/j.cca.2015.10.033] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Revised: 10/24/2015] [Accepted: 10/30/2015] [Indexed: 12/20/2022]
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7
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Mak ACY, Pullinger CR, Tang LF, Wong JS, Deo RC, Schwarz JM, Gugliucci A, Movsesyan I, Ishida BY, Chu C, Poon A, Kim P, Stock EO, Schaefer EJ, Asztalos BF, Castellano JM, Wyss-Coray T, Duncan JL, Miller BL, Kane JP, Kwok PY, Malloy MJ. Effects of the absence of apolipoprotein e on lipoproteins, neurocognitive function, and retinal function. JAMA Neurol 2015; 71:1228-36. [PMID: 25111166 DOI: 10.1001/jamaneurol.2014.2011] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
IMPORTANCE The identification of a patient with a rare form of severe dysbetalipoproteinemia allowed the study of the consequences of total absence of apolipoprotein E (apoE). OBJECTIVES To discover the molecular basis of this rare disorder and to determine the effects of complete absence of apoE on neurocognitive and visual function and on lipoprotein metabolism. DESIGN, SETTING, AND PARTICIPANTS Whole-exome sequencing was performed on the patient's DNA. He underwent detailed neurological and visual function testing and lipoprotein analysis. Lipoprotein analysis was also performed in the Cardiovascular Research Institute, University of California, San Francisco, on blood samples from the proband's mother, wife, 2 daughters, and normolipidemic control participants. MAIN OUTCOME MEASURES Whole-exome sequencing, lipoprotein analysis, and neurocognitive function. RESULTS The patient was homozygous for an ablative APOE frameshift mutation (c.291del, p.E97fs). No other mutations likely to contribute to the phenotype were discovered, with the possible exception of two, in ABCC2 (p.I670T) and LIPC (p.G137R). Despite complete absence of apoE, he had normal vision, exhibited normal cognitive, neurological, and retinal function, had normal findings on brain magnetic resonance imaging, and had normal cerebrospinal fluid levels of β-amyloid and tau proteins. He had no significant symptoms of cardiovascular disease except a suggestion of myocardial ischemia on treadmill testing and mild atherosclerosis noted on carotid ultrasonography. He had exceptionally high cholesterol content (760 mg/dL; to convert to millimoles per liter, multiply by 0.0259) and a high cholesterol to triglycerides ratio (1.52) in very low-density lipoproteins with elevated levels of small-diameter high-density lipoproteins, including high levels of prebeta-1 high-density lipoprotein. Intermediate-density lipoproteins, low-density lipoproteins, and very low-density lipoproteins contained elevated apoA-I and apoA-IV levels. The patient's apoC-III and apoC-IV levels were decreased in very low-density lipoproteins. Electron microscopy revealed large lamellar particles having electron-opaque cores attached to electron-lucent zones in intermediate-density and low-density lipoproteins. Low-density lipoprotein particle diameters were distributed bimodally. CONCLUSIONS AND RELEVANCE Despite a profound effect on lipoprotein metabolism, detailed neurocognitive and retinal studies failed to demonstrate any defects. This suggests that functions of apoE in the brain and eye are not essential or that redundant mechanisms exist whereby its role can be fulfilled. Targeted knockdown of apoE in the central nervous system might be a therapeutic modality in neurodegenerative disorders.
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Affiliation(s)
- Angel C Y Mak
- Cardiovascular Research Institute, University of California, San Francisco
| | - Clive R Pullinger
- Cardiovascular Research Institute, University of California, San Francisco
| | - Ling Fung Tang
- Cardiovascular Research Institute, University of California, San Francisco
| | - Jinny S Wong
- Gladstone Institute of Cardiovascular Disease, San Francisco, California
| | - Rahul C Deo
- Cardiovascular Research Institute, University of California, San Francisco
| | - Jean-Marc Schwarz
- College of Osteopathic Medicine, Touro University California, Vallejo
| | | | - Irina Movsesyan
- Cardiovascular Research Institute, University of California, San Francisco
| | | | - Catherine Chu
- Cardiovascular Research Institute, University of California, San Francisco
| | - Annie Poon
- Cardiovascular Research Institute, University of California, San Francisco
| | - Phillip Kim
- Darin M. Camarena Health Centers, Madera, California
| | - Eveline O Stock
- Cardiovascular Research Institute, University of California, San Francisco
| | | | | | - Joseph M Castellano
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, California
| | - Tony Wyss-Coray
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, California7Center for Tissue Regeneration, Repair, and Restoration, VA Palo Alto Health Care System, Palo Alto, California
| | - Jacque L Duncan
- Department of Ophthalmology, University of California, San Francisco
| | - Bruce L Miller
- Memory and Aging Center, University of California, San Francisco
| | - John P Kane
- Cardiovascular Research Institute, University of California, San Francisco
| | - Pui-Yan Kwok
- Cardiovascular Research Institute, University of California, San Francisco
| | - Mary J Malloy
- Cardiovascular Research Institute, University of California, San Francisco
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8
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Abstract
Apolipoprotein E (APOE) is a lipid-transport protein abundantly expressed in most neurons in the central nervous system. APOE-dependent alterations of the endocytic pathway can affect different functions. APOE binds to cell-surface receptors to deliver lipids and to the hydrophobic amyloid-β peptide, regulating amyloid-β aggregations and clearances in the brain. Several APOE isoforms with major structural differences were discovered and shown to influence the brain lipid transport, glucose metabolism, neuronal signaling, neuroinflammation, and mitochondrial function. This review will summarize the updated research progress on APOE functions and its role in Alzheimer's disease, Parkinson's disease, cardiovascular diseases, multiple sclerosis, type 2 diabetes mellitus, Type III hyperlipoproteinemia, vascular dementia, and ischemic stroke. Understanding the mutations in APOE, their structural properties, and their isoforms is important to determine its role in various diseases and to advance the development of therapeutic strategies. Targeting APOE may be a potential approach for diagnosis, risk assessment, prevention, and treatment of various neurodegenerative and cardiovascular diseases in humans.
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Affiliation(s)
- Vo Van Giau
- Department of Bionano Technology, Gachon Medical Research Institute, Gachon University, Seongnam, South Korea
| | - Eva Bagyinszky
- Department of Bionano Technology, Gachon Medical Research Institute, Gachon University, Seongnam, South Korea
| | - Seong Soo A An
- Department of Bionano Technology, Gachon Medical Research Institute, Gachon University, Seongnam, South Korea
| | - Sang Yun Kim
- Department of Neurology, Seoul National University College of Medicine in Seoul National Bundang Hospital, Seoul, South Korea
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9
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Hoffmann MM, Scharnagl H, Köster W, Winkler K, Wieland H, März W. Apolipoprotein E1 Baden (Arg(180)-->Cys). A new apolipoprotein E variant associated with hypertriglyceridemia. Clin Chim Acta 2001; 303:41-8. [PMID: 11163021 DOI: 10.1016/s0009-8981(00)00372-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Apolipoprotein (apo) E mediates the removal of chylomicron and very low density lipoprotein remnants from plasma. It is polymorphic in sequence and the products of the three common alleles (epsilon 2, epsilon 3, epsilon 4) differ from one another in their binding to lipoprotein receptors. ApoE2 is defective in binding and homozygosity for apoE2 is associated with type III hyperlipoproteinemia (HLP). Other rare isoforms of apoE have been found to be associated either with dominant type III HLP or with the development of hypertriglyceridemia. We identified a 42 year-old hypertriglyceridemic woman with an apoE phenotype 3/1. Restriction isotyping using AflIII/HaeII resulted in an apparent apoE genotype 3/2, suggesting that the mutation occurred in an epsilon 2 allele. DNA sequence analysis revealed a C-->T point mutation at the first position of the codon for amino acid residue 180 of the mature apoE. This predicted a change Arg(180)-->Cys. The mutation altered a recognition site for the endonuclease HaeII, which allowed us rapidly to screen for this mutation. In relatives of the proband, apoE1 Baden was consistently associated with hypertriglyceridemia. Similar to other apoE variants linked to hypertriglyceridemia, the Arg(180)-->Cys mutation is located within the lipid binding domain of apoE. We therefore suggest that apoE1 Baden may cause hypertrigylceridemia, possibly by inhibiting the hydrolysis of triglycerides associated with very low density lipoproteins.
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Affiliation(s)
- M M Hoffmann
- Division of Clinical Chemistry, Medical School, Albert Ludwigs-University, Hugstetter Str. 55, D-79106 Freiburg, Germany.
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10
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Abstract
Type III hyperlipoproteinemia (HLP) is usually associated with homozygosity for apolipoprotein (apo) E2 (Arg112 --> Cys, Arg158 --> Cys). This common apo E isoform is defective in its binding to lipoprotein receptors. However, other rare mutations in the apo epsilon gene may also, in part dominantly, predispose to the disease. In order to assess the prevalence of rare apo E variants and mutations in the apo epsilon gene in Germany, we examined apo epsilon genotypes by restriction isotyping (RI) and apo E phenotypes by isoelectric focusing (IEF) in 107 German patients with type III HLP. Concordance between apo epsilon genotype and apo E phenotype was observed in 101 subjects (94.4%). Six individuals (5.6%) had genotypes and phenotypes other than E2/2. One subject was apparently homozygous for apo E2 by IEF, but heterozygous for epsilon3/2 by RI. Sequencing of the apo epsilon gene disclosed a hitherto undescribed point mutation (TGG --> TGA) at the third position of the codon for amino acid 20 (Trp), introducing a premature termination codon. This is the first study demonstrating that in the German population type III HLP is mainly associated with homozygosity for apo E2 (Arg112 --> Cys, Arg158 --> Cys) and that discrepancies between apo epsilon genotype and apo E phenotype are rare in this genetic condition.
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Affiliation(s)
- G Feussner
- Medizinische Universitätsklinik, Heidelberg, Germany.
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11
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Abstract
One hundred forty-seven relatives of 43 patients with "classical" type III hyperlipoproteinemia (HLP) having the apolipoprotein (apo) E2/2 phenotype were studied to determine the occurrence of hyperlipidemia and the presence of further possible genes for lipoprotein disorders in these families. In 12 pedigrees primary dyslipidemia was prevalent among patients and respective blood-relatives. In these kindreds the coexistent presence of genes for familial combined hyperlipidemia (n = 6), familial hypertriglyceridemia (n = 5), and familial hypercholesterolemia (n = 1), respectively, was supposed. Our results, therefore, confirm and extend previous data on the multifactorial genesis of the diseases. Besides homozygosity for a receptor binding-defective isoform of apo E (apo E2), additional genes for familial lipoprotein disorders might operate in the pathogenesis of type III HLP. This is the largest family study performed so far in this primary lipoprotein disorder.
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Affiliation(s)
- G Feussner
- Abteilung Innere Medizin I, Medizinische Universitätsklinik Heidelberg, Germany
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12
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Orth M, Weng W, Funke H, Steinmetz A, Assmann G, Nauck M, Dierkes J, Ambrosch A, Weisgraber KH, Mahley RW, Wieland H, Luley C. Effects of a frequent apolipoprotein E isoform, ApoE4Freiburg (Leu28-->Pro), on lipoproteins and the prevalence of coronary artery disease in whites. Arterioscler Thromb Vasc Biol 1999; 19:1306-15. [PMID: 10323784 DOI: 10.1161/01.atv.19.5.1306] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Different isoforms of apoE modulate the concentrations of plasma lipoproteins and the risk for atherosclerosis. A novel apoE isoform, apoE4Freiburg, was detected in plasma by isoelectric focusing because its isoelectric point is slightly more acidic than that of apoE4. ApoE4Freiburg results from a base exchange in the APOE4 gene that causes the replacement of a leucine by a proline at position 28. Analysis of the allelic frequencies in whites in southwestern Germany revealed that this isoform is frequent among control subjects (10:4264 alleles) and is even more frequent in patients with coronary artery disease (21:2874 alleles; P=0.004; adjusted odds ratio, 3.09; 95% confidence interval, 1.20 to 7.97). ApoE4Freiburg affects serum lipoproteins by lowering cholesterol, apoB, and apoA-I compared with apoE4 (P<0.05). Our 4 apoE4Freiburg homozygotes suffered from various phenotypes of hyperlipoproteinemia (types IIa, IIb, IV, and V). In vitro binding studies excluded a binding defect of apoE4Freiburg, and in vivo studies excluded an abnormal accumulation of chylomicron remnants. ApoE4Freiburg and apoE4 accumulated to a similar extent in triglyceride-rich lipoproteins. HDLs, however, contained about 40% less apoE4Freiburg than apoE4. In conclusion, our data indicate that apoE4Freiburg exerts its possible atherogenic properties by affecting the metabolism of triglyceride-rich lipoproteins and HDL.
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Affiliation(s)
- M Orth
- Institut für Klinische Chemie und Pathobiochemie, Universität Magdeburg, Germany
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13
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Groß W, März W. Application of electrophoretic techniques to the diagnosis of disorders of lipoprotein metabolism. Examples at the levels of lipoproteins and apolipoproteins. Anal Chim Acta 1999. [DOI: 10.1016/s0003-2670(98)00497-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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14
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Orth M, Luley C. Diagnostic pitfalls during therapy for extreme hypertriglyceridaemia. EUROPEAN JOURNAL OF CLINICAL CHEMISTRY AND CLINICAL BIOCHEMISTRY : JOURNAL OF THE FORUM OF EUROPEAN CLINICAL CHEMISTRY SOCIETIES 1997; 35:101-3. [PMID: 9056751 DOI: 10.1515/cclm.1997.35.2.101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
We report the case of a 34-year-old man with extreme hypertriglyceridaemia (276.6 mmol/l) that was corrected by diet and triple-drug therapy. No primary defect could be found despite an intensive biochemical and genetic evaluation. Early in the time course of triglyceride-lowering therapy, the composition and concentration of different lipoprotein species changed markedly. His lipoprotein profile mimicked type III hyperlipidaemia, then familial hypercholesterolaemia, and finally hyperalphalipoproteinaemia. The increase in LDL cholesterol and apolipoprotein B was paralleled by a sixfold increase in lipoprotein(a). We conclude that these different forms of hypercholesterolaemia disappear solely with a continuation of the triglyceride-lowering therapy.
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Affiliation(s)
- M Orth
- Medizinische Klinik der Albert-Ludwigs Universität, Abteilung Klinische Chemie, Freiburg, Germany
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15
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Pocovi M, Cenarro A, Civeira F, Myers RH, Casao E, Esteban M, Ordovas JM. Incomplete dominance of type III hyperlipoproteinemia is associated with the rare apolipoprotein E2 (Arg136-->Ser) variant in multigenerational pedigree studies. Atherosclerosis 1996; 122:33-46. [PMID: 8724110 DOI: 10.1016/0021-9150(95)06745-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
In the process of screening apolipoprotein (apo) E genotypes in a population of subjects with lipid abnormalities, we have identified five subjects (one homozygote and four heterozygotes) with an abnormal 109 base pairs band following apo E restriction isotyping of amplified DNA with the restriction endonuclease CfoI. The polymerase chain reaction (PCR) products were cloned and their sequencing revealed a C-->A substitution at the first nucleotide of codon 136. This mutation resulted in an amino acid substitution Arg to Ser, previously described as apo E2 Christchurch. Family studies were carried out for four of the probands. In these kindreds, stepwise multiple regression analyses indicated that 78% of the cholesterol variability in men was predicted by body mass index, age and the rare apo E2 (Arg136-->Ser) variant. In women, age and the apo E2 (Arg136-->Ser variant predicted 54.9% of the variability in cholesterol levels. Linkage analysis suggested that the presence of the apo E2 (Arg136-->Ser) variant was linked with the occurrence of cholesterol enriched triglyceride rich lipoproteins and with an incomplete dominance of type III hyperlipoproteinemia. Our data indicates that this mutation may be a relatively common cause of dyslipidemia in the Spanish population.
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Affiliation(s)
- M Pocovi
- Department of Biochemistry and Molecular and Cellular Biology, University of Zaragoza, Spain
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Dobmeyer J, Lohrmann J, Feussner G. Prevalence and association of atherosclerosis at three different arterial sites in patients with type III hyperlipoproteinemia. Atherosclerosis 1996; 119:89-98. [PMID: 8929260 DOI: 10.1016/0021-9150(95)05633-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
We have examined the prevalence of clinically significant atherosclerosis in 78 patients with type III hyperlipoproteinemia (HLP) and homozygosity for apolipoprotein (apo) E2. Forty-six of these individuals (59%) had no atherosclerosis, 32 patients (41%) had atherosclerosis, i.e., atherosclerosis of the extracranial carotid arteries (CAA), coronary arteries (CAD) or/and peripheral arteries of the legs (PVD), either singly or in combination. No association could be shown with respect to the co-prevalence of atherosclerotic lesions at these different arterial sites, except for the high predictive value (pv = 0.88, P = 0.006) of CAA for the presence of PVD. Hence, documentation of atherosclerosis under clinical aspects at one of these exposed arterial territories does not allow a reliable prediction of generalised atherosclerosis or local atherosclerosis at other sites of the arterial tree in individuals with this familial lipoprotein disorder. Therefore, assessment of the extent of clinically significant atherosclerosis in type III HLP patients should include careful and thorough examination of the extracranial carotid arteries, the coronary arteries, and the peripheral arteries of the legs.
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Affiliation(s)
- J Dobmeyer
- Department of Internal Medicine I, Endocrinology and Metabolism, University of Heidelberg, Germany
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Hergenc G, Taga Y, Emerk K, Cirakoglu B. Apolipoprotein E Genotyping in Turkish Myocardial Infarction Survivors and Healthy Controls. J Biomed Sci 1995; 2:46-49. [PMID: 11725040 DOI: 10.1007/bf02257924] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
The apolipoprotein (Apo) E gene is known to be polymorphic. Three common alleles determine six phenotypes which can easily be detected by restriction fragment length polymorphism. We performed apo E genotyping in myocardial infarction survivors and healthy controls for the first time in the Turkish population. DNA was amplified by polymerase chain reaction (PCR) and the PCR product was digested with restriction enzymes HhaI to detect apo E2, E3, E4 and with TaqI to detect apo E1. Relative allele frequency for the patient group was found to be 0.91 for E3, 0.07 for E2, 0.02 for E4 and for the control group 0.875 for E3, 0.067 for E2, 0.058 for E4. Copyright 1995 S. Karger AG, Basel
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Affiliation(s)
- G. Hergenc
- Department of Biochemistry, Medical Faculty, Marmara University, Istanbul, Turkey
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18
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Maekawa B, Cole TG, Seip RL, Bylund D. Apolipoprotein E genotyping methods for the clinical laboratory. J Clin Lab Anal 1995; 9:63-9. [PMID: 7722775 DOI: 10.1002/jcla.1860090112] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
To select the best method for detecting apolipoprotein E (apo E) genotypes determined by the three common alleles epsilon 2, epsilon 3 and epsilon 4, we compared the radiolabeled allele-specific oligonucleotide (ASO) probe assay and the nonisotopic restriction isotyping assay. Leukocytic DNA was extracted from the blood of 93 patients after which the region containing two mutation points coding amino acid residues 112 and 158 was amplified by using the polymerase chain reaction (PCR). Amplified DNA fragments were spotted on nylon membranes, then hybridized for the ASO probe assay. The amplified DNA fragments were also digested with restriction endonuclease Hhal, followed by polyacrylamide gel electrophoresis for the restriction isotyping assay. The apo E genotypes determined by both methods for every specimen studied were in complete agreement. Although the radiolabeled ASO probe method was 10 times more sensitive than restriction isotyping on polyacrylamide gel, the two were comparable in accuracy. Additionally, because it is simpler to perform, is less time consuming, and is less expensive, we conclude that the restriction isotyping assay is the more suitable of these two methods for use in a clinical laboratory.
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Affiliation(s)
- B Maekawa
- Tsukuba Research Laboratory, Hitachi Chemical Co., Ltd., Ibaraki, Japan
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19
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Feussner G, Feussner V, Ziegler R. Apolipoprotein (a) phenotypes and lipoprotein (a) concentrations in patients with type III hyperlipoproteinaemia. J Intern Med 1994; 235:425-30. [PMID: 8182397 DOI: 10.1111/j.1365-2796.1994.tb01098.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
OBJECTIVES The familial lipoprotein disorder type III hyperlipoproteinaemia (HLP) carries a marked increase in the risk of accelerated and premature atherosclerosis, but there is considerable variation amongst affected individuals in their susceptibility to cardiovascular disease (CVD). Therefore, it was the aim of our study to investigate the possible influence of lipoprotein (a) [Lp(a)] in the pathogenesis of type III HLP: DESIGN Apolipoprotein (a) [apo(a)] phenotypes and Lp(a) concentrations were determined in patients with the disease and in an appropriate control group. SETTING University out-patient lipid disorder clinic. SUBJECTS Seventy-six apoE-2 homozygous patients with type III HLP and 76 normolipidaemic and healthy age- and sex-matched controls. MAIN OUTCOME MEASURES The frequencies of different apo(a) phenotypes and their correlations with Lp(a) serum concentrations were determined in patients and controls. RESULTS Lp(a) concentrations were not significantly different in type III HLP patients (14.1 +/- 19.1 mg dl-1) as compared with the controls (13.3 +/- 16.2 mg dl-1; P = 0.549, NS). In addition, there was no significant difference in apo(a) phenotype frequencies amongst both groups (0.2 > P > 0.1). CONCLUSIONS We conclude that the apo(a) polymorphism does not participate (to a significant extent) in the phenotypical expression of type III HLP:
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Affiliation(s)
- G Feussner
- Department of Internal Medicine I (Endocrinology and Metabolism), University of Heidelberg, Germany
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de Knijff P, van den Maagdenberg AM, Frants RR, Havekes LM. Genetic heterogeneity of apolipoprotein E and its influence on plasma lipid and lipoprotein levels. Hum Mutat 1994; 4:178-94. [PMID: 7833947 DOI: 10.1002/humu.1380040303] [Citation(s) in RCA: 91] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Apolipoprotein E (apoE) is one of the major protein constituents of chylomicron and very-low-density lipoprotein (VLDL) remnants and plays a central role as a ligand in the receptor-mediated uptake of these particles by the liver. Including the most common variant, apoE3, 30 apoE variants have been characterized. At present, 14 apoE variants have been found to be associated with familial dysbetalipoproteinemia, a genetic lipid disorder characterized by elevated plasma cholesterol and triglyceride levels and an increased risk for atherosclerosis. Seven apoE variants were found to be associated with other forms of hyperlipoproteinemia. This report presents an overview of all currently known apoE variants and their effects on lipoprotein metabolism.
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Affiliation(s)
- P de Knijff
- TNO Institute of Prevention and Health Research, Gaubius Laboratory, Leiden, The Netherlands
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Wenham PR, McDowell IF, Hodges VM, McEneny J, O'Kane MJ, Davies RJ, Nicholls DP, Trimble ER, Blundell G. Rare apolipoprotein E variant identified in a patient with type III hyperlipidaemia. Atherosclerosis 1993; 99:261-71. [PMID: 8503953 DOI: 10.1016/0021-9150(93)90028-s] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
We report a rare apolipoprotein E variant in an Irish female with Type III hyperlipidaemia who has the phenotype E2E1 as determined by isoelectric focusing. Sequence analysis of the apolipoprotein E gene from the proband and from four other family members, using DNA amplified by the polymerase chain reaction, demonstrated the presence of a point mutation in the common epsilon 2 allele with a G-->A transition at nucleotide 3791. This was confirmed by digestion with the restriction endonuclease TaqI, which cuts at a new site within the apolipoprotein E gene, created by the base change. This mutation results in a substitution of aspartic acid for glycine at position 127 of the mature protein. We believe this to be the first description of this apolipoprotein E variant in a family from the British Isles. The mutation appears to be 'recessive' with respect to the expression of Type III hyperlipidaemia, although it may be somewhat more potent in this regard than the parent epsilon 2 allele. The Type III hyperlipidaemia is responsive to treatment with diet and gemfibrozil.
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Affiliation(s)
- P R Wenham
- Department of Clinical Biochemistry, Western General Hospital, Edinburgh, UK
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