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Darabi N, Mashayekhy M, Borjian Boroujeni P, Mohtasebi P, Rokhsat Talab Z, Zamanian MR. APOE-E4 allele as a potential marker for implantation failure: A comparison between fertile women, ART success and RIF patients. Int J Gynaecol Obstet 2024. [PMID: 38619378 DOI: 10.1002/ijgo.15537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2023] [Revised: 03/13/2024] [Accepted: 04/02/2024] [Indexed: 04/16/2024]
Abstract
OBJECTIVE Apolipoprotein E (APOE) is the most important precursor for the production of steroid hormones and is also involved in regulating the function of steroid hormones, hence playing a significant role in reproductive processes. So, APOE gene expression may be correlated with the implantation process. This study tries to make a better clarification of the correlation between APOE gene polymorphisms and recurrent implantation failure (RIF), where we compared the frequency of APOE polymorphisms in RIF patients, assisted reproductive treatment (ART) success cases and fertile women. METHOD In all, 100 women with successful ART who got pregnant (fetal heart rate positive) in their first or second cycle of in vitro fertilization or intracytoplasmic sperm injection, 100 infertile RIF cases, and 100 normal fertile control cases with at least one live birth were included in present study. Following DNA extraction, genotypes were determined through polymerase chain reaction-restriction fragment length polymorphism method using HhaI restriction enzyme. Finally, statistical analysis was performed by chi-squared (χ2) test in SPSS software (P < 0.05). RESULTS The RIF group showed significantly higher frequency for E3/E4 genotype (29%) compared with the other two control groups (fertile = 15%, ART success [ART+] = 13%) (P = 0.007). There was also a significantly higher frequency of the E4 allele in the RIF group (14.5%) compared with both of the control groups (fertile = 7.5%, ART+ = 6.5%) (P = 0.018). CONCLUSION APOE4 is correlated with recurrent failure in the process of embryo implantation and, accordingly, it may potentially be considered a possible risk factor to the implantation process. The presence of E4 can be proposed as a predictive indicator in determining the results of assisted reproductive techniques.
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Affiliation(s)
- Nazanin Darabi
- Department of Molecular Cell Biology-Genetics, Faculty of Basic Sciences and Advanced Technologies in Biology, University of Science and Culture, ACECR, Tehran, Iran
- Department of Genetics, Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran
| | - Mehri Mashayekhy
- Department of Endocrinology and Female Infertility, Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran
| | - Parnaz Borjian Boroujeni
- Department of Genetics, Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran
| | - Parinaz Mohtasebi
- Department of Biology, Missouri State University, Springfield, Missouri, USA
| | - Zeinab Rokhsat Talab
- Department of Genetics, Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran
| | - Mohammad Reza Zamanian
- Department of Genetics, Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran
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2
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Strickland MR, Rau MJ, Summers B, Basore K, Wulf J, Jiang H, Chen Y, Ulrich JD, Randolph GJ, Zhang R, Fitzpatrick JAJ, Cashikar AG, Holtzman DM. Apolipoprotein E secreted by astrocytes forms antiparallel dimers in discoidal lipoproteins. Neuron 2024; 112:1100-1109.e5. [PMID: 38266643 PMCID: PMC10994765 DOI: 10.1016/j.neuron.2023.12.018] [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: 09/11/2023] [Revised: 11/24/2023] [Accepted: 12/22/2023] [Indexed: 01/26/2024]
Abstract
The Apolipoprotein E gene (APOE) is of great interest due to its role as a risk factor for late-onset Alzheimer's disease. ApoE is secreted by astrocytes in the central nervous system in high-density lipoprotein (HDL)-like lipoproteins. Structural models of lipidated ApoE of high resolution could aid in a mechanistic understanding of how ApoE functions in health and disease. Using monoclonal Fab and F(ab')2 fragments, we characterize the structure of lipidated ApoE on astrocyte-secreted lipoproteins. Our results provide support for the "double-belt" model of ApoE in nascent discoidal HDL-like lipoproteins, where two ApoE proteins wrap around the nanodisc in an antiparallel conformation. We further show that lipidated, recombinant ApoE accurately models astrocyte-secreted ApoE lipoproteins. Cryogenic electron microscopy of recombinant lipidated ApoE further supports ApoE adopting antiparallel dimers in nascent discoidal lipoproteins.
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Affiliation(s)
| | - Michael J Rau
- Washington University Center for Cellular Imaging, 660 S. Euclid Ave., St. Louis, MO 63110, USA
| | - Brock Summers
- Washington University Center for Cellular Imaging, 660 S. Euclid Ave., St. Louis, MO 63110, USA
| | - Katherine Basore
- Washington University Center for Cellular Imaging, 660 S. Euclid Ave., St. Louis, MO 63110, USA
| | - John Wulf
- Washington University Center for Cellular Imaging, 660 S. Euclid Ave., St. Louis, MO 63110, USA
| | - Hong Jiang
- Department of Neurology, 660 S. Euclid Ave., St. Louis, MO 63110, USA
| | - Yun Chen
- Department of Neurology, 660 S. Euclid Ave., St. Louis, MO 63110, USA; Department of Pathology and Immunology, 660 S. Euclid Ave., St. Louis, MO 63110, USA
| | - Jason D Ulrich
- Department of Neurology, 660 S. Euclid Ave., St. Louis, MO 63110, USA; Hope Center for Neurological Disorders, 660 S. Euclid Ave., St. Louis, MO 63110, USA; Knight Alzheimer's Disease Research Center, 4488 Forest Park Ave., St. Louis, MO 63108, USA
| | - Gwendalyn J Randolph
- Department of Pathology and Immunology, 660 S. Euclid Ave., St. Louis, MO 63110, USA
| | - Rui Zhang
- Department of Biochemistry and Molecular Biophysics, 660 S. Euclid Ave., St. Louis, MO 63110, USA
| | - James A J Fitzpatrick
- Washington University Center for Cellular Imaging, 660 S. Euclid Ave., St. Louis, MO 63110, USA
| | - Anil G Cashikar
- Hope Center for Neurological Disorders, 660 S. Euclid Ave., St. Louis, MO 63110, USA; Department of Psychiatry, 660 S. Euclid Ave., St. Louis, MO 63110, USA; Taylor Family institute for Innovative Psychiatric Research, 660 S. Euclid Ave., St. Louis, MO 63110, USA
| | - David M Holtzman
- Department of Neurology, 660 S. Euclid Ave., St. Louis, MO 63110, USA; Hope Center for Neurological Disorders, 660 S. Euclid Ave., St. Louis, MO 63110, USA; Knight Alzheimer's Disease Research Center, 4488 Forest Park Ave., St. Louis, MO 63108, USA.
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3
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Valencia-Olvera AC, Balu D, Moore A, Shah M, Ainis R, Xiang B, Saleh Y, Cai D, LaDu MJ, Tai LM. APOE2 Heterozygosity Reduces Hippocampal Soluble Amyloid-β42 Levels in Non-Hyperlipidemic Mice. J Alzheimers Dis 2024; 97:1629-1639. [PMID: 38306049 DOI: 10.3233/jad-231210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2024]
Abstract
APOE2 lowers Alzheimer's disease (AD) risk; unfortunately, the mechanism remains poorly understood and the use of mice models is problematic as APOE2 homozygosity is associated with hyperlipidemia. In this study, we developed mice that are heterozygous for APOE2 and APOE3 or APOE4 and overexpress amyloid-β peptide (Aβ) (EFAD) to evaluate the effect of APOE2 dosage on Aβ pathology. We found that heterozygous mice do not exhibit hyperlipidemia. Hippocampal but not cortical levels of soluble Aβ42 followed the order E2/2FAD > E2/3FAD≤E3/3FAD and E2/2FAD > E2/4FAD < E4/4FAD without an effect on insoluble Aβ42. These findings offer initial insights on the impact of APOE2 on Aβ pathology.
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Affiliation(s)
- Ana C Valencia-Olvera
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL, USA
| | - Deebika Balu
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL, USA
| | | | - Maitri Shah
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL, USA
| | - Rebecca Ainis
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL, USA
| | | | - Yaseen Saleh
- University of Miami/Jackson Healthcare System, Miami, FL, USA
| | - Dongming Cai
- Alzheimer Disease Research Center, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Research and Development Service, James J. Peters VA Medical Center, Bronx, NY, USA
- Department of Neurology, N. Bud Grossman Center for Memory Research and Care, University of Minnesota, Minneapolis, MN, USA
- Geriatric Research Education and Clinical Center (GRECC), Minneapolis VA Health Care System, Minneapolis, MN, USA
| | - Mary Jo LaDu
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL, USA
| | - Leon M Tai
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL, USA
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4
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Vecchio FL, Bisceglia P, Imbimbo BP, Lozupone M, Latino RR, Resta E, Leone M, Solfrizzi V, Greco A, Daniele A, Watling M, Panza F, Seripa D. Are apolipoprotein E fragments a promising new therapeutic target for Alzheimer’s disease? Ther Adv Chronic Dis 2022; 13:20406223221081605. [PMID: 35321401 PMCID: PMC8935560 DOI: 10.1177/20406223221081605] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Accepted: 01/28/2022] [Indexed: 11/17/2022] Open
Abstract
Human apolipoprotein E (ApoE) is a 299-amino acid secreted glycoprotein that binds cholesterol and phospholipids. ApoE exists as three common isoforms (ApoE2, ApoE3, and ApoE4) and heterozygous carriers of the ε4 allele of the gene encoding ApoE (APOE) have a fourfold greater risk of developing Alzheimer’s disease (AD). The enzymes thrombin, cathepsin D, α-chymotrypsin-like serine protease, and high-temperature requirement serine protease A1 are responsible for ApoE proteolytic processing resulting in bioactive C-terminal-truncated fragments that vary depending on ApoE isoforms, brain region, aging, and neural injury. The objectives of the present narrative review were to describe ApoE processing, discussing current hypotheses about the potential role of various ApoE fragments in AD pathophysiology, and reviewing the current development status of different anti-ApoE drugs. The exact mechanism by which APOE gene variants increase/decrease AD risk and the role of ApoE fragments in the deposition are not fully understood, but APOE is known to directly affect tau-mediated neurodegeneration. ApoE fragments co-localize with neurofibrillary tangles and amyloid β (Aβ) plaques, and may cause neurodegeneration. Among anti-ApoE approaches, a fascinating strategy may be to therapeutically overexpress ApoE2 in APOE ε4/ε4 carriers through vector administration or liposomal delivery systems. Another approach involves reducing ApoE4 expression by intracerebroventricular antisense oligonucleotides that significantly decreased Aβ pathology in transgenic mice. Differences in the proteolytic processing of distinct ApoE isoforms and the use of ApoE fragments as mimetic peptides in AD treatment are also under investigation. Treatment with peptides that mimic the structural and biological properties of native ApoE may reduce Aβ deposition, tau hyperphosphorylation, and glial activation in mouse models of Aβ pathology. Alternative strategies involve the use of ApoE4 structure correctors, passive immunization to target a certain form of ApoE, conversion of the ApoE4 aminoacid sequence into that of ApoE3 or ApoE2, and inhibition of the ApoE-Aβ interaction.
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Affiliation(s)
- Filomena Lo Vecchio
- Research Laboratory, Complex Structure of Geriatrics, Department of Medical Sciences, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Foggia 71013, Italy
| | - Paola Bisceglia
- Research Laboratory, Complex Structure of Geriatrics, Department of Medical Sciences, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | | | - Madia Lozupone
- Neurodegenerative Disease Unit, Department of Basic Medicine, Neuroscience, and Sense Organs, University of Bari Aldo Moro, Bari, Italy
| | - Raffaela Rita Latino
- Complex Structure of Neurology, Department of Medical Sciences, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Emanuela Resta
- Translational Medicine and Management of Health Systems, University of Foggia, Foggia, Italy
| | - Maurizio Leone
- Complex Structure of Neurology, Department of Medical Sciences, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Vincenzo Solfrizzi
- ‘Cesare Frugoni’ Internal and Geriatric Medicine and Memory Unit, University of Bari ‘Aldo Moro’, Bari, Italy
| | - Antonio Greco
- Department of Neuroscience, Catholic University of the Sacred Heart, Rome, Italy; Neurology Unit, IRCCS Fondazione Policlinico Universitario A. Gemelli, Rome, Italy
- Research Laboratory, Complex Structure of Geriatrics, Department of Medical Sciences, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | | | - Mark Watling
- CNS & Pain Department, TranScrip Ltd, Reading, UK
| | - Francesco Panza
- Research Laboratory, Complex Structure of Geriatrics, Department of Medical Sciences, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Foggia, Italy
- Population Health Unit, Healthy Aging Phenotypes Research Unit, ‘Salus in Apulia Study’, National Institute of Gastroenterology ‘Saverio de Bellis’, Research Hospital, Castellana Grotte, Bari 70013, Italy
| | - Davide Seripa
- Research Laboratory, Complex Structure of Geriatrics, Department of Medical Sciences, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
- Hematology and Stem Cell Transplant Unit, ‘Vito Fazzi’ Hospital, Lecce, Italy
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5
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Gharibyan AL, Wasana Jayaweera S, Lehmann M, Anan I, Olofsson A. Endogenous Human Proteins Interfering with Amyloid Formation. Biomolecules 2022; 12:biom12030446. [PMID: 35327638 PMCID: PMC8946693 DOI: 10.3390/biom12030446] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 03/08/2022] [Accepted: 03/11/2022] [Indexed: 01/09/2023] Open
Abstract
Amyloid formation is a pathological process associated with a wide range of degenerative disorders, including Alzheimer’s disease, Parkinson’s disease, and diabetes mellitus type 2. During disease progression, abnormal accumulation and deposition of proteinaceous material are accompanied by tissue degradation, inflammation, and dysfunction. Agents that can interfere with the process of amyloid formation or target already formed amyloid assemblies are consequently of therapeutic interest. In this context, a few endogenous proteins have been associated with an anti-amyloidogenic activity. Here, we review the properties of transthyretin, apolipoprotein E, clusterin, and BRICHOS protein domain which all effectively interfere with amyloid in vitro, as well as displaying a clinical impact in humans or animal models. Their involvement in the amyloid formation process is discussed, which may aid and inspire new strategies for therapeutic interventions.
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Affiliation(s)
- Anna L. Gharibyan
- Department of Clinical Microbiology, Umeå University, 901 87 Umeå, Sweden;
- Correspondence: (A.L.G.); (A.O.)
| | | | - Manuela Lehmann
- Department of Public Health and Clinical Medicine, Umeå University, 901 87 Umeå, Sweden; (M.L.); (I.A.)
| | - Intissar Anan
- Department of Public Health and Clinical Medicine, Umeå University, 901 87 Umeå, Sweden; (M.L.); (I.A.)
| | - Anders Olofsson
- Department of Clinical Microbiology, Umeå University, 901 87 Umeå, Sweden;
- Correspondence: (A.L.G.); (A.O.)
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6
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Moon HJ, Haroutunian V, Zhao L. Human apolipoprotein E isoforms are differentially sialylated and the sialic acid moiety in ApoE2 attenuates ApoE2-Aβ interaction and Aβ fibrillation. Neurobiol Dis 2022; 164:105631. [PMID: 35041991 PMCID: PMC9809161 DOI: 10.1016/j.nbd.2022.105631] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 01/09/2022] [Accepted: 01/11/2022] [Indexed: 01/05/2023] Open
Abstract
The APOE genotype is the most prominent genetic risk factor for the development of late-onset Alzheimer''s disease (LOAD); however, the underlying mechanisms remain unclear. In the present study, we found that the sialylation profiles of ApoE protein in the human brain are significantly different among the three isoforms, with ApoE2 exhibiting the most abundant sialic acid modification whereas ApoE4 had the least. We further observed that the sialic acid moiety in ApoE2 significantly affected the interaction between ApoE2 and Aβ peptides. The removal of sialic acid in ApoE2 increased the ApoE2 binding affinity for the Aβ17-24 region of Aβ and promoted Aβ fibrillation. These findings provide a plausible explanation for the well-documented differential roles of ApoE isoforms in Aβ pathogenesis. Specifically, compared to the other two isotypes, the higher expression of sialic acid in ApoE2 may contribute to the less potent interaction between ApoE2 and Aβ and ultimately the slower rate of brain Aβ deposition, a mechanism thought to underlie ApoE2-mediated decreased risk for AD. Future studies are warranted to determine whether the differential sialylation in ApoE isoforms may also contribute to some of their other distinct properties, such as their divergent preferences in associations with lipids and lipoproteins, as well as their potential impact on neuroinflammation through modulation of microglial Siglec activity. Overall, our findings lead to the insight that the sialic acid structure is an important posttranslational modification (PTM) that alters ApoE protein functions with relevance for AD.
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Affiliation(s)
- Hee-Jung Moon
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, KS 66045, USA
| | - Vahram Haroutunian
- The Alzheimer's Disease Research Center, Icahn School of Medicine at Mount Sinai, New York, NY 100029, USA
| | - Liqin Zhao
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, KS 66045, USA; Neuroscience Graduate Program, University of Kansas, Lawrence, KS 66045, USA.
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7
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Hu ML, Quinn J, Xue K. Interactions between Apolipoprotein E Metabolism and Retinal Inflammation in Age-Related Macular Degeneration. Life (Basel) 2021; 11:life11070635. [PMID: 34210002 PMCID: PMC8305051 DOI: 10.3390/life11070635] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 06/24/2021] [Accepted: 06/27/2021] [Indexed: 02/07/2023] Open
Abstract
Age-related macular degeneration (AMD) is a multifactorial retinal disorder that is a major global cause of severe visual impairment. The development of an effective therapy to treat geographic atrophy, the predominant form of AMD, remains elusive due to the incomplete understanding of its pathogenesis. Central to AMD diagnosis and pathology are the hallmark lipid and proteinaceous deposits, drusen and reticular pseudodrusen, that accumulate in the subretinal pigment epithelium and subretinal spaces, respectively. Age-related changes and environmental stressors, such as smoking and a high-fat diet, are believed to interact with the many genetic risk variants that have been identified in several major biochemical pathways, including lipoprotein metabolism and the complement system. The APOE gene, encoding apolipoprotein E (APOE), is a major genetic risk factor for AMD, with the APOE2 allele conferring increased risk and APOE4 conferring reduced risk, in comparison to the wildtype APOE3. Paradoxically, APOE4 is the main genetic risk factor in Alzheimer’s disease, a disease with features of neuroinflammation and amyloid-beta deposition in common with AMD. The potential interactions of APOE with the complement system and amyloid-beta are discussed here to shed light on their roles in AMD pathogenesis, including in drusen biogenesis, immune cell activation and recruitment, and retinal inflammation.
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Affiliation(s)
- Monica L. Hu
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC 3002, Australia;
| | - Joel Quinn
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK;
| | - Kanmin Xue
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK;
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 9DU, UK
- Correspondence:
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Differences in Recycling of Apolipoprotein E3 and E4-LDL Receptor Complexes-A Mechanistic Hypothesis. Int J Mol Sci 2021; 22:ijms22095030. [PMID: 34068576 PMCID: PMC8126166 DOI: 10.3390/ijms22095030] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 05/05/2021] [Accepted: 05/07/2021] [Indexed: 12/13/2022] Open
Abstract
Apolipoprotein E (ApoE) is a protein that plays an important role in the transport of fatty acids and cholesterol and in cellular signaling. On the surface of the cells, ApoE lipoparticles bind to low density lipoprotein receptors (LDLR) that mediate the uptake of the lipids and downstream signaling events. There are three alleles of the human ApoE gene. Presence of ApoE4 allele is a major risk factor for developing Alzheimer’s disease (AD) and other disorders late in life, but the mechanisms responsible for biological differences between different ApoE isoforms are not well understood. We here propose that the differences between ApoE isoforms can be explained by differences in the pH-dependence of the association between ApoE3 and ApoE4 isoforms and LDL-A repeats of LDLR. As a result, the following endocytosis ApoE3-associated LDLRs are recycled back to the plasma membrane but ApoE4-containing LDLR complexes are trapped in late endosomes and targeted for degradation. The proposed mechanism is predicted to lead to a reduction in steady-state surface levels of LDLRs and impaired cellular signaling in ApoE4-expressing cells. We hope that this proposal will stimulate experimental research in this direction that allows the testing of our hypothesis.
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Association of APOE genotype with lipid profiles and type 2 diabetes mellitus in a Korean population. Genes Genomics 2021; 43:725-735. [PMID: 33864613 DOI: 10.1007/s13258-021-01095-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Accepted: 03/29/2021] [Indexed: 12/15/2022]
Abstract
BACKGROUND Type 2 diabetes mellitus (T2DM) is associated with chronic hyperglycemia and lipid metabolism. A previous genome-wide association study revealed the TOMM40-APOE region as novel locus for T2DM susceptibility. OBJECTIVE This association study was conducted to determine the genetic effects of APOE single nucleotide polymorphisms (SNPs) on T2DM susceptibility and lipid profiles in a Korean population. METHODS A total of 6 tagging SNPs, including rs7412 and rs429358, were selected for ε genotype analysis and genotyped in 1436 subjects, consisting of 352 T2DM patients and 1084 unaffected controls. RESULTS Logistic regression analyses were conducted and there were no significant associations among the APOE 6 tagging SNPs, ε genotypes, and haplotypes with T2DM susceptibility. To investigate the association of the APOE tagging SNPs with the lipid profiles, a regression analysis was conducted. As a result, rs7412 was significantly associated with the total cholesterol (TC) and low-density lipoprotein cholesterol (LDL) levels (Pcorr = 2.30 × 10-5 and 3.39 × 10-13, respectively) in the unaffected controls. The ε2 allele and ε3 allele were significantly associated with the TC (Pcorr = 4.46 × 10-6 and 0.02, respectively) and LDL levels (Pcorr = 3.54 × 10-14 and 0.0006, respectively) in the unaffected controls. Further analysis of only the unaffected controls was conducted. As a result, the APOE alleles ε2 and ε3 showed a significant association with the TC and LDL levels (P < 0.05). CONCLUSION The results of this study may help in understanding APOE polymorphisms and ε alleles and lipid profiles, which have been highly linked to T2DM, in a Korean population.
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Gamache J, Yun Y, Chiba-Falek O. Sex-dependent effect of APOE on Alzheimer's disease and other age-related neurodegenerative disorders. Dis Model Mech 2020; 13:dmm045211. [PMID: 32859588 PMCID: PMC7473656 DOI: 10.1242/dmm.045211] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The importance of apolipoprotein E (APOE) in late-onset Alzheimer's disease (LOAD) has been firmly established, but the mechanisms through which it exerts its pathogenic effects remain elusive. In addition, the sex-dependent effects of APOE on LOAD risk and endophenotypes have yet to be explained. In this Review, we revisit the different aspects of APOE involvement in neurodegeneration and neurological diseases, with particular attention to sex differences in the contribution of APOE to LOAD susceptibility. We discuss the role of APOE in a broader range of age-related neurodegenerative diseases, and summarize the biological factors linking APOE to sex hormones, drawing on supportive findings from rodent models to identify major mechanistic themes underlying the exacerbation of LOAD-associated neurodegeneration and pathology in the female brain. Additionally, we list sex-by-genotype interactions identified across neurodegenerative diseases, proposing APOE variants as a shared etiology for sex differences in the manifestation of these diseases. Finally, we present recent advancements in 'omics' technologies, which provide a new platform for more in-depth investigations of how dysregulation of this gene affects the development and progression of neurodegenerative diseases. Collectively, the evidence summarized in this Review highlights the interplay between APOE and sex as a key factor in the etiology of LOAD and other age-related neurodegenerative diseases. We emphasize the importance of careful examination of sex as a contributing factor in studying the underpinning genetics of neurodegenerative diseases in general, but particularly for LOAD.
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Affiliation(s)
- Julia Gamache
- Division of Translational Brain Sciences, Department of Neurology, Duke University Medical Center, Durham, NC 27710, USA
- Center for Genomic and Computational Biology, Duke University Medical Center, Durham, NC 27708, USA
| | - Young Yun
- Division of Translational Brain Sciences, Department of Neurology, Duke University Medical Center, Durham, NC 27710, USA
- Center for Genomic and Computational Biology, Duke University Medical Center, Durham, NC 27708, USA
| | - Ornit Chiba-Falek
- Division of Translational Brain Sciences, Department of Neurology, Duke University Medical Center, Durham, NC 27710, USA
- Center for Genomic and Computational Biology, Duke University Medical Center, Durham, NC 27708, USA
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Shi J, Cheng Z, Qiu S, Cui H, Gu Y, Zhao Q, Ren Y, Zhang H, Sun H, Liu Y, Li Y, Qiao Y, Hu Y, Liu Y, Cheng Y. ε2 allele and ε2-involved genotypes (ε2/ε2, ε2/ε3, and ε2/ε4) may confer the association of APOE genetic polymorphism with risks of nephropathy in type 2 diabetes: a meta-analysis. Lipids Health Dis 2020; 19:136. [PMID: 32534589 PMCID: PMC7293775 DOI: 10.1186/s12944-020-01307-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2019] [Accepted: 06/02/2020] [Indexed: 01/11/2023] Open
Abstract
Background Diabetic nephropathy (DN) contributes to end-stage renal failure. Microvascular injury resulted from reactive oxygen species is implicated in the pathogenesis of DN. Genetic polymorphism of Apolipoprotein E (APOE) influences the antioxidative properties of the protein. The relationship of APOE polymorphism with the risks of nephropathy in type 2 diabetes (T2DN) remains elusive. Methods An up-to-date meta-analysis was conducted on the basis of studies selected from PubMed, WanFang database, Embase, Vip database, Web of Science, Scopus, and CNKI database. Results A total of 33 studies conferring 3266 cases and 3259 controls were selected on the basis of criteria of inclusion and exclusion in this meta-analysis. For APOE alleles, the pooled odds ratio (OR) of ε2 vs. ε3 was 1.89 (95% confidence intervals [95% CI]: 1.49–2.38, P < 0.0001). With regard to APOE genotypes, ε2/ε2, ε2/ε3, and ε2/ε4 increased the risk of T2DN (ε2/ε2 vs. ε3/ε3: OR = 2.32, 95% CI: 1.52–3.56, P = 0.0001; ε2/ε3 vs. ε3/ε3: OR = 1.97, 95% CI: 1.50–2.59, P<0.0001; ε2/ε4 vs. ε3/ε3: OR = 1.69, 95% CI: 1.18–2.44, P = 0.0046). Conclusions This meta-analysis found that the APOE ε2 allele and the ε2-involved genotypes (ε2/ε2, ε2/ε3, and ε2/ε4) are the risk factors of T2DN.
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Affiliation(s)
- Jikang Shi
- Department of Epidemiology and Biostatistics, School of Public Health, Jilin University, Changchun, 130021, Jilin, China
| | - Zhaorui Cheng
- Class of Clinical Medicine of English Teaching, Grade 2016, Ottawa-Shanghai Joint School of Medicine, Shanghai Jiao Tong University, Shanghai, 200023, China
| | - Shuang Qiu
- Department of Epidemiology and Biostatistics, School of Public Health, Jilin University, Changchun, 130021, Jilin, China
| | - Heran Cui
- Department of Epidemiology and Biostatistics, School of Public Health, Jilin University, Changchun, 130021, Jilin, China
| | - Yulu Gu
- Department of Epidemiology and Biostatistics, School of Public Health, Jilin University, Changchun, 130021, Jilin, China
| | - Qian Zhao
- Department of Epidemiology and Biostatistics, School of Public Health, Jilin University, Changchun, 130021, Jilin, China
| | - Yaxuan Ren
- Department of Epidemiology and Biostatistics, School of Public Health, Jilin University, Changchun, 130021, Jilin, China
| | - He Zhang
- Department of Epidemiology and Biostatistics, School of Public Health, Jilin University, Changchun, 130021, Jilin, China
| | - Helin Sun
- Department of Epidemiology and Biostatistics, School of Public Health, Jilin University, Changchun, 130021, Jilin, China
| | - Yunkai Liu
- Institute of Translational Medicine, The First Hospital of Jilin University, Changchun, 130021, Jilin, China
| | - Yong Li
- Department of Epidemiology and Biostatistics, School of Public Health, Jilin University, Changchun, 130021, Jilin, China
| | - Yichun Qiao
- Department of Epidemiology and Biostatistics, School of Public Health, Jilin University, Changchun, 130021, Jilin, China
| | - Yueyang Hu
- Department of children & adolescence health, School of Public Health, Jilin University, Changchun, 130021, Jilin, China
| | - Yawen Liu
- Department of Epidemiology and Biostatistics, School of Public Health, Jilin University, Changchun, 130021, Jilin, China.
| | - Yi Cheng
- Institute of Translational Medicine, The First Hospital of Jilin University, Changchun, 130021, Jilin, China.
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12
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Apolipoprotein E and Alzheimer disease: pathobiology and targeting strategies. Nat Rev Neurol 2019; 15:501-518. [PMID: 31367008 DOI: 10.1038/s41582-019-0228-7] [Citation(s) in RCA: 635] [Impact Index Per Article: 127.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/13/2019] [Indexed: 02/06/2023]
Abstract
Polymorphism in the apolipoprotein E (APOE) gene is a major genetic risk determinant of late-onset Alzheimer disease (AD), with the APOE*ε4 allele conferring an increased risk and the APOE*ε2 allele conferring a decreased risk relative to the common APOE*ε3 allele. Strong evidence from clinical and basic research suggests that a major pathway by which APOE4 increases the risk of AD is by driving earlier and more abundant amyloid pathology in the brains of APOE*ε4 carriers. The number of amyloid-β (Aβ)-dependent and Aβ-independent pathways that are known to be differentially modulated by APOE isoforms is increasing. For example, evidence is accumulating that APOE influences tau pathology, tau-mediated neurodegeneration and microglial responses to AD-related pathologies. In addition, APOE4 is either pathogenic or shows reduced efficiency in multiple brain homeostatic pathways, including lipid transport, synaptic integrity and plasticity, glucose metabolism and cerebrovascular function. Here, we review the recent progress in clinical and basic research into the role of APOE in AD pathogenesis. We also discuss how APOE can be targeted for AD therapy using a precision medicine approach.
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13
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Kai-Han T, Abhari D, Narayanaswami V. Conformational analysis of apolipoprotein E3/E4 heteromerization. FEBS J 2019; 286:1986-1998. [PMID: 30802357 PMCID: PMC6733585 DOI: 10.1111/febs.14794] [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: 11/05/2018] [Revised: 01/29/2019] [Accepted: 02/22/2019] [Indexed: 11/26/2022]
Abstract
Apolipoprotein E (apoE) is a 299 residue, exchangeable apolipoprotein that has essential roles in cholesterol homeostasis and reverse cholesterol transport. It is a two-domain protein with the C-terminal (CT) domain mediating protein self-association via helix-helix interactions. In humans, the APOE gene is polymorphic with three common alleles, ε2, ε3, and ε4, occurring in frequencies of ~ 5%, 77%, and 18%, respectively. Heterozygotes expressing apoE3 and apoE4 isoforms, which differ in residue at position 112 in the N-terminal domain (C112 in apoE3 and R112 in apoE4), represent the highest population of ε4 carriers, an allele highly associated with Alzheimer's disease. The objective of this study was to determine if apoE3 and apoE4 have the ability to hybridize to form a heteromer in lipid-free state. Refolding an equimolar mixture of His-apoE3 and FLAG-apoE4 (or vice versa) followed by pull-down and immunoblotting indicated formation of apoE3/apoE4 heteromers. Förster resonance energy transfer between donor fluorophore on one isoform and acceptor on the other, both located in the respective CT domains, revealed a distance of separation of ~ 46 Å between the donor/acceptor pair. Similarly, a quencher placed on one was able to mediate significant quenching of fluorescence emission on the other, indicative of spatial proximity within collisional distance between the two. ApoE3/apoE4 heteromer association was also noted in lipid-associated state in reconstituted lipoprotein particles. The possibility of heteromerization of apoE3/apoE4 bears implications in the potential mitigating role of apoE3 on the folding and physiological behavior of apoE4 and its role in maintaining cholesterol homeostasis.
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Affiliation(s)
| | | | - Vasanthy Narayanaswami
- Department of Chemistry and Biochemistry, 1250 Bellflower Blvd., California State University Long Beach, Long Beach, CA 90840, USA
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14
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Raulin AC, Kraft L, Al-Hilaly YK, Xue WF, McGeehan JE, Atack JR, Serpell L. The Molecular Basis for Apolipoprotein E4 as the Major Risk Factor for Late-Onset Alzheimer's Disease. J Mol Biol 2019; 431:2248-2265. [PMID: 31051176 PMCID: PMC6556554 DOI: 10.1016/j.jmb.2019.04.019] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 04/16/2019] [Accepted: 04/16/2019] [Indexed: 11/28/2022]
Abstract
Apolipoprotein E4 (ApoE4) is one of three (E2, E3 and E4) human isoforms of an α-helical, 299-amino-acid protein. Homozygosity for the ε4 allele is the major genetic risk factor for developing late-onset Alzheimer's disease (AD). ApoE2, ApoE3 and ApoE4 differ at amino acid positions 112 and 158, and these sequence variations may confer conformational differences that underlie their participation in the risk of developing AD. Here, we compared the shape, oligomerization state, conformation and stability of ApoE isoforms using a range of complementary biophysical methods including small-angle x-ray scattering, analytical ultracentrifugation, circular dichroism, x-ray fiber diffraction and transmission electron microscopy We provide an in-depth and definitive study demonstrating that all three proteins are similar in stability and conformation. However, we show that ApoE4 has a propensity to polymerize to form wavy filaments, which do not share the characteristics of cross-β amyloid fibrils. Moreover, we provide evidence for the inhibition of ApoE4 fibril formation by ApoE3. This study shows that recombinant ApoE isoforms show no significant differences at the structural or conformational level. However, self-assembly of the ApoE4 isoform may play a role in pathogenesis, and these results open opportunities for uncovering new triggers for AD onset.
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Affiliation(s)
- Ana-Caroline Raulin
- Sussex Neuroscience, School of Life Sciences, University of Sussex, Falmer, Brighton, East Sussex BN1 6NN, UK
| | - Lucas Kraft
- Sussex Drug Discovery Centre, School of Life Sciences, University of Sussex, Falmer, Brighton, East Sussex , BN1 6NN, UK
| | - Youssra K Al-Hilaly
- Sussex Neuroscience, School of Life Sciences, University of Sussex, Falmer, Brighton, East Sussex BN1 6NN, UK; Chemistry Department, College of Science, Mustansiriyah University, Baghdad, Iraq
| | - Wei-Feng Xue
- School of Biosciences, University of Kent, Canterbury, England CT2 7NJ, UK
| | - John E McGeehan
- School of Biological Sciences, Institute of Biological and Biomedical Sciences, Faculty of Science, University of Portsmouth, Portsmouth, Hampshire PO1 2DY, UK
| | - John R Atack
- Sussex Drug Discovery Centre, School of Life Sciences, University of Sussex, Falmer, Brighton, East Sussex , BN1 6NN, UK
| | - Louise Serpell
- Sussex Neuroscience, School of Life Sciences, University of Sussex, Falmer, Brighton, East Sussex BN1 6NN, UK.
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The Genetic Variability of APOE in Different Human Populations and Its Implications for Longevity. Genes (Basel) 2019; 10:genes10030222. [PMID: 30884759 PMCID: PMC6471373 DOI: 10.3390/genes10030222] [Citation(s) in RCA: 84] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 03/01/2019] [Accepted: 03/12/2019] [Indexed: 12/11/2022] Open
Abstract
Human longevity is a complex phenotype resulting from the combinations of context-dependent gene-environment interactions that require analysis as a dynamic process in a cohesive ecological and evolutionary framework. Genome-wide association (GWAS) and whole-genome sequencing (WGS) studies on centenarians pointed toward the inclusion of the apolipoprotein E (APOE) polymorphisms ε2 and ε4, as implicated in the attainment of extreme longevity, which refers to their effect in age-related Alzheimer's disease (AD) and cardiovascular disease (CVD). In this case, the available literature on APOE and its involvement in longevity is described according to an anthropological and population genetics perspective. This aims to highlight the evolutionary history of this gene, how its participation in several biological pathways relates to human longevity, and which evolutionary dynamics may have shaped the distribution of APOE haplotypes across the globe. Its potential adaptive role will be described along with implications for the study of longevity in different human groups. This review also presents an updated overview of the worldwide distribution of APOE alleles based on modern day data from public databases and ancient DNA samples retrieved from literature in the attempt to understand the spatial and temporal frame in which present-day patterns of APOE variation evolved.
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16
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Identifying genetic markers associated with susceptibility to cardiovascular diseases. Future Sci OA 2018; 5:FSO350. [PMID: 30652019 PMCID: PMC6331704 DOI: 10.4155/fsoa-2018-0031] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Accepted: 09/18/2018] [Indexed: 12/25/2022] Open
Abstract
The development of cardiovascular diseases (CVDs) is due to a complex interaction between the genome and the environment. Understanding how genetic differences in individuals contribute to their susceptibility to CVDs can help guide practitioners to give the best advice to achieve a favorable outcome for the patient. As genome technologies evolve, genotyping of individuals could be available to all patients using a simple saliva test. Large-scale genome-wide association studies and meta analyses have provided powerful insights into polymorphisms that may be predictive of disease and an individual's response to certain nutrients, but moving forward it is imperative that these insights can be applied in the medical setting to reduce the incidence and mortality of CVDs. Cardiovascular diseases (CVDs) are the leading cause of death worldwide, and while most CVDs can be prevented by adopting a healthy lifestyle, this is only half the story. Evidence suggests changes in an individual's genes or DNA can cause some form of CVDs, highlighting a complex relationship between genes and the environment. Genotyping, a process used to determine genetic differences within an individual's DNA, can provide doctors with relevant information to identify individuals who are at high risk of developing CVDs. This would allow treatment to begin early and encourage individuals to adopt a healthy lifestyle to reduce their risk.
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Liehn EA, Ponomariov V, Diaconu R, Streata I, Ioana M, Crespo-Avilan GE, Hernández-Reséndiz S, Cabrera-Fuentes HA. Apolipoprotein E in Cardiovascular Diseases: Novel Aspects of an Old-fashioned Enigma. Arch Med Res 2018; 49:522-529. [PMID: 30213474 DOI: 10.1016/j.arcmed.2018.08.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Accepted: 08/24/2018] [Indexed: 12/30/2022]
Abstract
The presence of different APOE isoforms represents a well-known risk factor for cardiovascular diseases. Besides the pleiotropic effects of APOE polymorphism on heart and neurological diseases, this review summarizes the less-known functions of APOE and the possible implications for cardiovascular disorders. Beyond the role as lipid transporting protein, its involvement in lipid membrane homeostasis and signaling, as well as its nuclear transcriptional effects suggests a more complex role of APOE, receiving great interest from researchers and physicians from all medical fields. Due to the presence of different APOE isoforms in human population, understanding APOE's role in pathological processes represents not only a challenge, but a demand for further development of therapeutic strategies for cardiovascular diseases.
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Affiliation(s)
- Elisa A Liehn
- Institute for Molecular Cardiovascular Research, Rheinisch Westfälische Technische Hochschule Aachen University, Aachen, Germany; Human Genomics Laboratory, University of Medicine and Pharmacy Craiova, Craiova, Romania; Department of Cardiology, Pulmonology, Angiology and Intensive Care, University Hospital, Rheinisch Westfälische Technische Hochschule, Aachen, Germany
| | - Victor Ponomariov
- Institute for Molecular Cardiovascular Research, Rheinisch Westfälische Technische Hochschule Aachen University, Aachen, Germany; Human Genomics Laboratory, University of Medicine and Pharmacy Craiova, Craiova, Romania
| | - Rodica Diaconu
- Human Genomics Laboratory, University of Medicine and Pharmacy Craiova, Craiova, Romania
| | - Ioana Streata
- Human Genomics Laboratory, University of Medicine and Pharmacy Craiova, Craiova, Romania
| | - Mihai Ioana
- Human Genomics Laboratory, University of Medicine and Pharmacy Craiova, Craiova, Romania
| | - Gustavo E Crespo-Avilan
- Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore, Singapore; National Heart Research Institute Singapore, National Heart Centre Singapore, Singapore
| | - Sauri Hernández-Reséndiz
- Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore, Singapore; National Heart Research Institute Singapore, National Heart Centre Singapore, Singapore
| | - Hector A Cabrera-Fuentes
- Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore, Singapore; National Heart Research Institute Singapore, National Heart Centre Singapore, Singapore; Kazan Federal University, Department of Microbiology, Kazan, Russian Federation; Escuela de Ingenieria y Ciencias, Centro de Biotecnologia-FEMSA, Tecnologico de Monterrey, Nuevo Leon, México; Institute of Biochemistry, Medical School, Justus-Liebig-University, Giessen, Germany.
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18
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Liu X, Zhan W, Wu Q, Wang F, Yang B, Ou Q. Polymorphism and plasma levels of apolipoprotein E and the risk of aneurysmal subarachnoid hemorrhage in a Chinese population: a case-control study. Lipids Health Dis 2018; 17:115. [PMID: 29769126 PMCID: PMC5956582 DOI: 10.1186/s12944-018-0755-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Accepted: 04/23/2018] [Indexed: 12/03/2022] Open
Abstract
Background Aneurysmal subarachnoid hemorrhage (aSAH) is the most common types of subarachnoid hemorrhage, which is a critical clinical problem with high morbidity, mortality, and economic impact. Recent studies have shown that APOE was a genetic risk factor of aSAH, however, the studies lack consistent conclusions and the evidence from Chinese Han population is rare. Objective To determine the relationship between APOE polymorphism and the incidence of aSAH in Chinese Fujian Han population and explore the possible mechanism of ApoE in the pathogenesis of aSAH. Methods A total of 131 patients newly diagnosed with aSAH were selected as aSAH group and 137 healthy subjects were selected as the control group. All the samples were analyzed for blood lipids and serum ApoE levels, and ApoE genotype was determined by a commercial chip and further confirmed with Sanger sequencing. An adjusted multivariate logistic regression analysis was carried out to estimate the effects of APOE polymorphism on the risk of aSAH. Results Compared with the controls, the serum TC, HDL-C and ApoA1 levels in aSAH were significantly lower: TC (4.52 ± 1.38 vs. 5.11 ± 0.86 mmol/L, P < 0.001), HDL-C (1.23 ± 0.46 vs. 1.44 ± 0.32 mmol/L, P < 0.001) and ApoA1 (1.20 ± 0.32 vs. 1.38 ± 0.25 g/L, P < 0.001). The distribution of ε2/ε3 genotype (19.08% vs. 9.49%, P = 0.038) and ε2 allele frequency (11.07% vs. 5.84%, P = 0.039) was significantly higher in aSAH than the healthy controls. The multivariate logistic regression identified that ApoE ε2 allele was independently associated with aSAH (OR = 2.083; and 95% CI = 1.045-4.153, P = 0.037). The serum ApoE in aSAH were significantly higher than controls (53.03 ± 24.64 vs. 45.06 ± 12.84 mg/L, P = 0.010). Conclusion APOE polymorphism might be associated with the incidence of aSAH in Chinese Fujian Han population. ApoE ε2 may be a risk factor for the incidence of aSAH, which may be related with the impacts of ApoE genotypes for the serum lipids, especially for the plasma levels of ApoE.
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Affiliation(s)
- Xiaofeng Liu
- Department of Laboratory Medicine, the First Affiliated Hospital of Fujian Medical University, No.20 Chazhong Road, Fuzhou, 350005, China. .,Gene Diagnostic Laboratory, the First Affiliated Hospital of Fujian Medical University, No.20 Chazhong Road, Fuzhou, 350005, China.
| | - Weiwu Zhan
- Department of Laboratory Medicine, the First Affiliated Hospital of Fujian Medical University, No.20 Chazhong Road, Fuzhou, 350005, China
| | - Qiumei Wu
- Department of Laboratory Medicine, the First Affiliated Hospital of Fujian Medical University, No.20 Chazhong Road, Fuzhou, 350005, China
| | - Fengqing Wang
- Department of Laboratory Medicine, the First Affiliated Hospital of Fujian Medical University, No.20 Chazhong Road, Fuzhou, 350005, China
| | - Bin Yang
- Department of Laboratory Medicine, the First Affiliated Hospital of Fujian Medical University, No.20 Chazhong Road, Fuzhou, 350005, China.,Gene Diagnostic Laboratory, the First Affiliated Hospital of Fujian Medical University, No.20 Chazhong Road, Fuzhou, 350005, China
| | - Qishui Ou
- Department of Laboratory Medicine, the First Affiliated Hospital of Fujian Medical University, No.20 Chazhong Road, Fuzhou, 350005, China. .,Gene Diagnostic Laboratory, the First Affiliated Hospital of Fujian Medical University, No.20 Chazhong Road, Fuzhou, 350005, China.
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Corsetti JP, Sparks CE, Bakker SJ, Gruppen EG, Dullaart RP. Roles of high apolipoprotein E blood levels and HDL in development of familial dysbetalipoproteinemia in ε2ε2 subjects. Clin Biochem 2018; 52:67-72. [DOI: 10.1016/j.clinbiochem.2017.11.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Revised: 11/14/2017] [Accepted: 11/16/2017] [Indexed: 12/11/2022]
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20
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Suvatha A, Kandi SM, Bhat DI, Rao N, Vazhayil V, Kasturirangan CG. Apolipoprotein E polymorphism and the risk of aneurysmal subarachnoid hemorrhage in a South Indian population. Cell Mol Biol Lett 2017; 22:25. [PMID: 29213291 PMCID: PMC5708094 DOI: 10.1186/s11658-017-0059-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 11/21/2017] [Indexed: 12/16/2022] Open
Abstract
Background The rupture of a brain aneurysm causes bleeding in the subarachnoid space. This is known as aneurysmal subarachnoid hemorrhage (aSAH). We evaluated the association of apolipoprotein E (APOE) polymorphism and the risk of aSAH in a South Indian population. Methods The study was performed on 200 subjects with aSAH and 253 healthy control subjects. Blood samples (5 ml) were used to isolate DNA and genotyping was performed for rs7412 and rs429358 using a Taqman allelic discrimination assay. Statistical software R.3.0.11 was used to statistically analyze the data and a p value < 0.05 was considered as statistically significant. Results We found a significant association with the risk of aSAH in ε3/ ε4 genetic model (OR = 1.91, 95% CI = 1.16-3.14, p = 0.01). However, in the other genetic models and allele frequency, there was no significant association with the risk of aSAH. In subtyping, we found a significant association of ε2 allele frequency with posterior communicating artery (PCOM) aneurysm (OR = 3.59, 95% CI = 1.11-11.64, p = 0.03). Conclusion Our results suggest that APOE polymorphism has an influence on the risk of aSAH in this South Indian population, specifically in the PCOM subtype.
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Affiliation(s)
- Arati Suvatha
- Department of Human Genetics, National Institute of Mental Health and Neuro Sciences, Bangalore, Karnataka 560029 India
| | - Sibin Madathan Kandi
- Department of Human Genetics, National Institute of Mental Health and Neuro Sciences, Bangalore, Karnataka 560029 India
| | - Dhananjaya Ishwara Bhat
- Department of Neurosurgery, National Institute of Mental Health and Neuro Sciences, Bangalore, 560029 India
| | - Narasinga Rao
- Department of Neurosurgery, National Institute of Mental Health and Neuro Sciences, Bangalore, 560029 India
| | - Vikas Vazhayil
- Department of Neurosurgery, National Institute of Mental Health and Neuro Sciences, Bangalore, 560029 India
| | - Chetan Ghati Kasturirangan
- Department of Human Genetics, National Institute of Mental Health and Neuro Sciences, Bangalore, Karnataka 560029 India
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Kara E, Marks JD, Fan Z, Klickstein JA, Roe AD, Krogh KA, Wegmann S, Maesako M, Luo CC, Mylvaganam R, Berezovska O, Hudry E, Hyman BT. Isoform- and cell type-specific structure of apolipoprotein E lipoparticles as revealed by a novel Forster resonance energy transfer assay. J Biol Chem 2017; 292:14720-14729. [PMID: 28684412 DOI: 10.1074/jbc.m117.784264] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Revised: 06/14/2017] [Indexed: 11/06/2022] Open
Abstract
Apolipoprotein E (apoE) has an important role in the pathogenesis of Alzheimer's disease with its three isoforms having distinct effects on disease risk. Here, we assessed the conformational differences between those isoforms using a novel flow cytometry-Forster resonance energy transfer (FRET) assay. We showed that the conformation of intracellular apoE within HEK cells and astrocytes adopts a directional pattern; in other words, E4 adopts the most closed conformation, E2 adopts the most open conformation, and E3 adopts an intermediate conformation. However, this pattern was not maintained upon secretion of apoE from astrocytes. Intermolecular interactions between apoE molecules were isoform-specific, indicating a great diversity in the structure of apoE lipoparticles. Finally, we showed that secreted E4 is the most lipidated isoform in astrocytes, suggesting that increased lipidation acts as a folding chaperone enabling E4 to adopt a closed conformation. In conclusion, this study gives insights into apoE biology and establishes a robust screening system to monitor apoE conformation.
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Affiliation(s)
- Eleanna Kara
- From the Alzheimer's Disease Research Laboratory, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129 and
| | - Jordan D Marks
- From the Alzheimer's Disease Research Laboratory, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129 and
| | - Zhanyun Fan
- From the Alzheimer's Disease Research Laboratory, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129 and
| | - Jacob A Klickstein
- From the Alzheimer's Disease Research Laboratory, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129 and
| | - Allyson D Roe
- From the Alzheimer's Disease Research Laboratory, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129 and
| | - Kelly A Krogh
- From the Alzheimer's Disease Research Laboratory, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129 and
| | - Susanne Wegmann
- From the Alzheimer's Disease Research Laboratory, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129 and
| | - Masato Maesako
- From the Alzheimer's Disease Research Laboratory, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129 and
| | - Christina C Luo
- Molecular Pathology, Massachusetts General Hospital, Charlestown, Massachusetts 02129
| | - Ravi Mylvaganam
- Molecular Pathology, Massachusetts General Hospital, Charlestown, Massachusetts 02129
| | - Oksana Berezovska
- From the Alzheimer's Disease Research Laboratory, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129 and
| | - Eloise Hudry
- From the Alzheimer's Disease Research Laboratory, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129 and
| | - Bradley T Hyman
- From the Alzheimer's Disease Research Laboratory, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129 and
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Frieden C, Wang H, Ho CMW. A mechanism for lipid binding to apoE and the role of intrinsically disordered regions coupled to domain-domain interactions. Proc Natl Acad Sci U S A 2017; 114:6292-6297. [PMID: 28559318 PMCID: PMC5474821 DOI: 10.1073/pnas.1705080114] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Relative to the apolipoprotein E (apoE) E3 allele of the APOE gene, apoE4 strongly increases the risk for the development of late-onset Alzheimer's disease. However, apoE4 differs from apoE3 by only a single amino acid at position 112, which is arginine in apoE4 and cysteine in apoE3. It remains unclear why apoE3 and apoE4 are functionally different. Described here is a proposal for understanding the functional differences between these two isoforms with respect to lipid binding. A mechanism is proposed that is based on the full-length monomeric structure of the protein, on hydrogen-deuterium exchange mass spectrometry data, and on the role of intrinsically disordered regions to control protein motions. It is proposed that lipid binds between the N-terminal and C-terminal domains and that separation of the two domains, along with the presence of intrinsically disordered regions, controls this process. The mechanism explains why apoE3 differs from apoE4 with respect to different lipid-binding specificities, why lipid increases the binding of apoE to its receptor, and why specific residues are conserved.
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Affiliation(s)
- Carl Frieden
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO 63110;
| | - Hanliu Wang
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130
| | - Chris M W Ho
- Drug Design Methodologies LLC, St. Louis, MO 63103
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Plasma levels of apolipoprotein E, APOE genotype and risk of dementia and ischemic heart disease: A review. Atherosclerosis 2016; 255:145-155. [DOI: 10.1016/j.atherosclerosis.2016.10.037] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 10/08/2016] [Accepted: 10/19/2016] [Indexed: 12/12/2022]
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Natarajan P, Bis JC, Bielak LF, Cox AJ, Dörr M, Feitosa MF, Franceschini N, Guo X, Hwang SJ, Isaacs A, Jhun MA, Kavousi M, Li-Gao R, Lyytikäinen LP, Marioni RE, Schminke U, Stitziel NO, Tada H, van Setten J, Smith AV, Vojinovic D, Yanek LR, Yao J, Yerges-Armstrong LM, Amin N, Baber U, Borecki IB, Carr JJ, Chen YDI, Cupples LA, de Jong PA, de Koning H, de Vos BD, Demirkan A, Fuster V, Franco OH, Goodarzi MO, Harris TB, Heckbert SR, Heiss G, Hoffmann U, Hofman A, Išgum I, Jukema JW, Kähönen M, Kardia SLR, Kral BG, Launer LJ, Massaro J, Mehran R, Mitchell BD, Mosley TH, de Mutsert R, Newman AB, Nguyen KD, North KE, O'Connell JR, Oudkerk M, Pankow JS, Peloso GM, Post W, Province MA, Raffield LM, Raitakari OT, Reilly DF, Rivadeneira F, Rosendaal F, Sartori S, Taylor KD, Teumer A, Trompet S, Turner ST, Uitterlinden AG, Vaidya D, van der Lugt A, Völker U, Wardlaw JM, Wassel CL, Weiss S, Wojczynski MK, Becker DM, Becker LC, Boerwinkle E, Bowden DW, Deary IJ, Dehghan A, Felix SB, Gudnason V, Lehtimäki T, Mathias R, Mook-Kanamori DO, Psaty BM, Rader DJ, Rotter JI, Wilson JG, van Duijn CM, Völzke H, Kathiresan S, Peyser PA, O'Donnell CJ. Multiethnic Exome-Wide Association Study of Subclinical Atherosclerosis. ACTA ACUST UNITED AC 2016; 9:511-520. [PMID: 27872105 DOI: 10.1161/circgenetics.116.001572] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 10/13/2016] [Indexed: 12/13/2022]
Abstract
BACKGROUND The burden of subclinical atherosclerosis in asymptomatic individuals is heritable and associated with elevated risk of developing clinical coronary heart disease. We sought to identify genetic variants in protein-coding regions associated with subclinical atherosclerosis and the risk of subsequent coronary heart disease. METHODS AND RESULTS We studied a total of 25 109 European ancestry and African ancestry participants with coronary artery calcification (CAC) measured by cardiac computed tomography and 52 869 participants with common carotid intima-media thickness measured by ultrasonography within the CHARGE Consortium (Cohorts for Heart and Aging Research in Genomic Epidemiology). Participants were genotyped for 247 870 DNA sequence variants (231 539 in exons) across the genome. A meta-analysis of exome-wide association studies was performed across cohorts for CAC and carotid intima-media thickness. APOB p.Arg3527Gln was associated with 4-fold excess CAC (P=3×10-10). The APOE ε2 allele (p.Arg176Cys) was associated with both 22.3% reduced CAC (P=1×10-12) and 1.4% reduced carotid intima-media thickness (P=4×10-14) in carriers compared with noncarriers. In secondary analyses conditioning on low-density lipoprotein cholesterol concentration, the ε2 protective association with CAC, although attenuated, remained strongly significant. Additionally, the presence of ε2 was associated with reduced risk for coronary heart disease (odds ratio 0.77; P=1×10-11). CONCLUSIONS Exome-wide association meta-analysis demonstrates that protein-coding variants in APOB and APOE associate with subclinical atherosclerosis. APOE ε2 represents the first significant association for multiple subclinical atherosclerosis traits across multiple ethnicities, as well as clinical coronary heart disease.
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25
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Zhao J, Ma B, Nussinov R. Compilation and Analysis of Enzymes, Engineered Antibodies, and Nanoparticles Designed to Interfere with Amyloid-β Aggregation. Isr J Chem 2016. [DOI: 10.1002/ijch.201600093] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Jun Zhao
- Cancer and Inflammation Program; National Cancer Institute; Frederick Maryland 21702 USA
| | - Buyong Ma
- Basic Science Program; Leidos Biomedical Research, Inc.; Cancer and Inflammation Program; National Cancer Institute; Frederick Maryland 21702 USA
| | - Ruth Nussinov
- Basic Science Program; Leidos Biomedical Research, Inc.; Cancer and Inflammation Program; National Cancer Institute; Frederick Maryland 21702 USA
- Sackler Institute of Molecular Medicine; Department of Human Genetics and Molecular Medicine; Sackler School of Medicine; Tel Aviv University; Tel Aviv 69978 Israel
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26
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Sharma AK, Friedman DJ, Pollak MR, Alper SL. Structural characterization of the C-terminal coiled-coil domains of wild-type and kidney disease-associated mutants of apolipoprotein L1. FEBS J 2016; 283:1846-62. [PMID: 26945671 DOI: 10.1111/febs.13706] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2015] [Revised: 01/25/2016] [Accepted: 03/02/2016] [Indexed: 01/08/2023]
Abstract
Trypanosomes that cause sleeping sickness endocytose apolipoprotein L1 (APOL1)-containing trypanolytic factors from human serum, leading to trypanolytic death through generation of APOL1-associated lytic pores in trypanosomal membranes. The trypanosome Trypanosoma brucei rhodesiense counteracts trypanolysis by expressing the surface protein serum response-associated (SRA), which can bind APOL1 common variant G0 to block its trypanolytic activity. However, two missense variants in the C terminal predicted coiled-coil (CC) domains of human APOL1 G1 (S342G/I384M) and G2 (ΔN388Y389) decrease or abrogate APOL1 binding to T. brucei rhodesiense SRA, thus preserving APOL1 trypanolytic activity. These evolutionarily selected APOL1 missense variants, found at a high frequency in some populations of African descent, also confer elevated risk of kidney disease. Understanding the SRA-APOL1 interaction and the role of APOL1 G1 and G2 variants in kidney disease demands structural characterization of the APOL1 CC domain. Using CD, heteronuclear NMR, and molecular dynamics (MD) simulation on structural homology models, we report here unique and dynamic solution conformations of nephropathy variants G1 and G2 as compared with the common variant G0. Conformational plasticity in G1 and G2 CC domains led to interhelical α1-α2 approximation coupled with secondary structural changes and delimited motional properties absent in the G0 CC domain. The G1 substitutions conferred local structural changes principally along helix α1, whereas the G2 deletion altered the structure of both helix α2 and helix α1. These dynamic features of APOL1 CC variants likely reflect their intrinsic structural properties, and should help interpret future APOL1 structural studies and define the contribution of APOL1 risk variants to kidney disease.
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Affiliation(s)
- Alok K Sharma
- Nephrology Division, Harvard Medical School, Boston, MA, USA.,Center for Vascular Biology Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.,Department of Medicine, Harvard Medical School, Boston, MA, USA
| | - David J Friedman
- Nephrology Division, Harvard Medical School, Boston, MA, USA.,Center for Vascular Biology Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.,Department of Medicine, Harvard Medical School, Boston, MA, USA
| | - Martin R Pollak
- Nephrology Division, Harvard Medical School, Boston, MA, USA.,Department of Medicine, Harvard Medical School, Boston, MA, USA
| | - Seth L Alper
- Nephrology Division, Harvard Medical School, Boston, MA, USA.,Center for Vascular Biology Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.,Department of Medicine, Harvard Medical School, Boston, MA, USA
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Apolipoprotein E levels and apolipoprotein E genotypes in incident cardiovascular disease risk in subjects of the Prevention of Renal and Vascular End-stage disease study. J Clin Lipidol 2016; 10:842-850. [PMID: 27578115 DOI: 10.1016/j.jacl.2016.03.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Accepted: 03/05/2016] [Indexed: 11/21/2022]
Abstract
BACKGROUND Apolipoprotein E (apoE) is a component of all major lipoprotein classes with multiple functions including clearance of circulating triglyceride-rich lipoprotein particles and hepatic production of triglyceride-rich lipoprotein, thus affording several avenues for apoE involvement in atherosclerosis development. ApoE has 3 isoforms (E2, E3, and E4) based on a common genetic polymorphism. Numerous studies have been performed assessing cardiovascular disease (CVD) risk relative to the 6 resulting genotypes; however, surprisingly, few studies have been performed assessing risk attributable to apoE plasma levels either alone or in addition also taking into account apoE genotypes. OBJECTIVE To examine the role of apoE levels together with apoE genotypes on incident CVD risk in a large population-based cohort and also to afford preliminary characterization of atherogenic apoE-containing lipoprotein particles. METHODS Cox multivariable proportional hazards modeling was performed on a cohort of the Prevention of Renal and Vascular End-Stage Disease (PREVEND) study as a function of apoE levels and apoE genotypes adjusted for age, gender, and past history of CVD. Further modeling was performed with single addition of clinical and biomarker parameters to elucidate the nature of apoE-associated risk. RESULTS High apoE levels were demonstrated to be associated with CVD risk (hazard ratio per apoE standard deviation, 1.20; 95% confidence interval, 1.11-1.31; P < .0001) both overall and within the high-frequency apoE genotype groups (ε2ε3, ε3ε3, and ε3ε4). Only on addition of apoB-containing lipoprotein parameters to models, did apoE levels lose association with risk. CONCLUSIONS ApoE levels positively associate with incident CVD risk with apoE-associated risk likely residing in apoB-containing lipoproteins.
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Salazar C, Valdivia G, Ardiles ÁO, Ewer J, Palacios AG. Genetic variants associated with neurodegenerative Alzheimer disease in natural models. Biol Res 2016; 49:14. [PMID: 26919851 PMCID: PMC4769573 DOI: 10.1186/s40659-016-0072-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2015] [Accepted: 02/12/2016] [Indexed: 01/05/2023] Open
Abstract
The use of transgenic models for the study of neurodegenerative diseases has made valuable contributions to the field. However, some important limitations, including protein overexpression and general systemic compensation for the missing genes, has caused researchers to seek natural models that show the main biomarkers of neurodegenerative diseases during aging. Here we review some of these models-most of them rodents, focusing especially on the genetic variations in biomarkers for Alzheimer diseases, in order to explain their relationships with variants associated with the occurrence of the disease in humans.
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Affiliation(s)
- Claudia Salazar
- Facultad de Ciencia, Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile.
| | - Gonzalo Valdivia
- Facultad de Ciencia, Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile.
| | - Álvaro O Ardiles
- Facultad de Ciencia, Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile.
| | - John Ewer
- Facultad de Ciencia, Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile.
| | - Adrián G Palacios
- Facultad de Ciencia, Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile. .,Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Pasaje Harrington 287, Playa Ancha, 2360102, Valparaíso, Chile.
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Morita SY. Metabolism and Modification of Apolipoprotein B-Containing Lipoproteins Involved in Dyslipidemia and Atherosclerosis. Biol Pharm Bull 2016; 39:1-24. [DOI: 10.1248/bpb.b15-00716] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Shin-ya Morita
- Department of Pharmacy, Shiga University of Medical Science Hospital
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Rasmussen KL, Tybjærg-Hansen A, Nordestgaard BG, Frikke-Schmidt R. Plasma levels of apolipoprotein E and risk of ischemic heart disease in the general population. Atherosclerosis 2015; 246:63-70. [PMID: 26761769 DOI: 10.1016/j.atherosclerosis.2015.12.038] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Revised: 12/21/2015] [Accepted: 12/24/2015] [Indexed: 11/18/2022]
Abstract
BACKGROUND AND AIMS Triglyceride-rich lipoproteins are causally associated with high risk of ischemic heart disease (IHD), and apolipoprotein E (apoE) has a central role in their plasma clearance. While both quantitative and qualitative changes of apoE are established causes of rare dyslipidemia syndromes, it remains unclear whether plasma levels of apoE are associated with risk of IHD in the general population. METHODS We tested whether plasma levels of apoE at enrollment were associated with future risk of IHD and myocardial infarction (MI) in 91,695 individuals from the general population. RESULTS Multifactorially adjusted hazard ratios (HRs) for highest versus lowest apoE tertile were 1.15 (1.04-1.27) for IHD and 1.16 (1.00-1.36) for MI in men, and 0.94 (0.84-1.05) and 1.04 (0.85-1.26) in women. These associations were attenuated by adjustments for triglyceride levels. Corresponding HRs for highest versus lowest apoE tertile in ε33 carriers were 1.18 (1.03-1.36) for IHD and 1.21 (0.98-1.49) for MI in men, and 0.91 (0.78-1.06) and 0.93 (0.71-1.21) in women. Thus, the present associations were independent of APOE genotype. CONCLUSION These findings suggest that high plasma levels of apoE are associated with IHD in men but not in women. Triglyceride-rich lipoproteins may partly explain these associations.
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Affiliation(s)
- Katrine L Rasmussen
- Department of Clinical Biochemistry, Rigshospitalet, Blegdamsvej 9, DK-2100 Copenhagen, Denmark; Copenhagen University Hospital and Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen, Denmark.
| | - Anne Tybjærg-Hansen
- Department of Clinical Biochemistry, Rigshospitalet, Blegdamsvej 9, DK-2100 Copenhagen, Denmark; The Copenhagen City Heart Study, Frederiksberg Hospital, Nordre Fasanvej 57, DK-2000 Frederiksberg, Denmark; The Copenhagen General Population Study, Herlev and Gentofte Hospital, Herlev Ringvej 75, DK-2730 Herlev, Denmark; Copenhagen University Hospital and Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen, Denmark.
| | - Børge G Nordestgaard
- The Copenhagen City Heart Study, Frederiksberg Hospital, Nordre Fasanvej 57, DK-2000 Frederiksberg, Denmark; The Copenhagen General Population Study, Herlev and Gentofte Hospital, Herlev Ringvej 75, DK-2730 Herlev, Denmark; Department of Clinical Biochemistry, Herlev and Gentofte Hospital, Herlev Ringvej 75, DK-2730 Herlev, Denmark; Copenhagen University Hospital and Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen, Denmark.
| | - Ruth Frikke-Schmidt
- Department of Clinical Biochemistry, Rigshospitalet, Blegdamsvej 9, DK-2100 Copenhagen, Denmark; The Copenhagen General Population Study, Herlev and Gentofte Hospital, Herlev Ringvej 75, DK-2730 Herlev, Denmark; Copenhagen University Hospital and Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen, Denmark.
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ApoE4-specific Misfolded Intermediate Identified by Molecular Dynamics Simulations. PLoS Comput Biol 2015; 11:e1004359. [PMID: 26506597 PMCID: PMC4623519 DOI: 10.1371/journal.pcbi.1004359] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Accepted: 05/28/2015] [Indexed: 11/19/2022] Open
Abstract
The increased risk of developing Alzheimer's disease (AD) is associated with the APOE gene, which encodes for three variants of Apolipoprotein E, namely E2, E3, E4, differing only by two amino acids at positions 112 and 158. ApoE4 is known to be the strongest risk factor for AD onset, while ApoE3 and ApoE2 are considered to be the AD-neutral and AD-protective isoforms, respectively. It has been hypothesized that the ApoE isoforms may contribute to the development of AD by modifying the homeostasis of ApoE physiological partners and AD-related proteins in an isoform-specific fashion. Here we find that, despite the high sequence similarity among the three ApoE variants, only ApoE4 exhibits a misfolded intermediate state characterized by isoform-specific domain-domain interactions in molecular dynamics simulations. The existence of an ApoE4-specific intermediate state can contribute to the onset of AD by altering multiple cellular pathways involved in ApoE-dependent lipid transport efficiency or in AD-related protein aggregation and clearance. We present what we believe to be the first structural model of an ApoE4 misfolded intermediate state, which may serve to elucidate the molecular mechanism underlying the role of ApoE4 in AD pathogenesis. The knowledge of the structure for the ApoE4 folding intermediate provides a new platform for the rational design of alternative therapeutic strategies to fight AD.
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Phillips MC. Apolipoprotein E isoforms and lipoprotein metabolism. IUBMB Life 2015; 66:616-23. [PMID: 25328986 DOI: 10.1002/iub.1314] [Citation(s) in RCA: 199] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Accepted: 09/09/2014] [Indexed: 11/09/2022]
Abstract
Apolipoprotein (apo) E is a 299-residue protein which functions as a key regulator of plasma lipid levels. Human apoE exists as three common isoforms and the parent form, apoE3, operates optimally in promoting clearance of triglyceride (TG)-rich lipoproteins and is associated with normal plasma lipid levels. This result occurs because apoE3 possesses both the requisite lipid-binding ability and affinity for the low density lipoprotein receptor (LDLR) to mediate appropriate lipolytic processing and endocytosis of TG-rich lipoprotein remnant particles. ApoE2 which differs from apoE3 by the single amino acid substitution Arg158Cys located near the LDLR recognition site exhibits impaired binding to the receptor and an inability to promote clearance of TG-rich lipoprotein remnant particles; this isoform is associated with Type-III hyperlipoproteinemia. ApoE4 which differs from apoE3 by the single amino acid substitution Cys112Arg is also associated with dyslipidemia although binding of this isoform to the LDLR is unaffected. The amino acid substitution affects the organization and stability of both the N-terminal helix bundle domain and separately folded C-terminal domain so that apoE4 has enhanced lipid binding ability. As a consequence, apoE4 binds better than apoE3 to the surface of very low density lipoprotein (VLDL) particles and impairs their lipolytic processing in the circulation so that apoE4 is associated with a more pro-atherogenic lipoprotein-cholesterol distribution (higher VLDL-cholesterol/high density lipoprotein-cholesterol ratio). This review summarizes current understanding of the structural differences between apoE2, apoE3, and apoE4, and the molecular mechanisms responsible for the alterations in lipoprotein metabolism resulting from this polymorphism of apoE. Detailed knowledge of how expression of structurally distinct apoE variants modifies lipoprotein metabolism provides a basis for developing ways to manipulate the functionality of apoE in vivo.
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Affiliation(s)
- Michael C Phillips
- Division of Translational Medicine and Human Genetics, Perelman School of Medicine at the University of Pennsylvania, 11-130 Translational Research Center, Philadelphia, PA, USA
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Lo CJ, Chyan CL, Chen YC, Chang CF, Huang HB, Lin TH. Resonance assignments and secondary structure of apolipoprotein E C-terminal domain in DHPC micelles. BIOMOLECULAR NMR ASSIGNMENTS 2015; 9:187-190. [PMID: 25239652 DOI: 10.1007/s12104-014-9571-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Accepted: 09/02/2014] [Indexed: 06/03/2023]
Abstract
Human apolipoprotein E (apoE) has been known to play a key role in the transport of plasma cholesterol and lipoprotein metabolism. It is an apolipoprotein of 299 amino acids with a molecular mass, ~34 kDa. ApoE has three major isoforms, apoE2, apoE3, and apoE4 which differ only at residue 112 or 158. ApoE consists of two independently folded domains (N-terminal and C-terminal domain) separated by a hinge region. The N-terminal domain and C-terminal domain of apoE are responsible for the binding to receptor and to lipid, respectively. Since the high resolution structures of apoE in lipids are still unavailable to date, we therefore aim to resolve the structures in lipids by NMR. Here, we reported the resonance assignments and secondary structure distribution of the C-terminal domain of wild-type human apoE (residue 195-299) in the micelles formed by dihexanoylphosphatidylcholine. Our results may provide a novel structural model of apoE in micelles and may shed new light on the molecular mechanisms underlying the apoE related biological processes.
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Affiliation(s)
- Chi-Jen Lo
- Institute of Biochemistry and Molecular Biology, National Yang-Ming University, Taipei, 112, Taiwan, ROC
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34
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Frieden C. ApoE: the role of conserved residues in defining function. Protein Sci 2014; 24:138-44. [PMID: 25377861 DOI: 10.1002/pro.2597] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Revised: 10/24/2014] [Accepted: 10/29/2014] [Indexed: 01/31/2023]
Abstract
The amino acid sequences of apolipoprotein E (apoE) from 63 different mammalian species have been downloaded from the protein database. The sequences were compared to human apoE4 to determine conserved and non-conserved sequences of amino acids. ApoE4 is the major risk factor for the development of late onset Alzheimer's disease while apoE3, which differs from apoE4 by a single amino acid change at position 112, poses little or no risk for the development of this disease. Thus, the two proteins appear to be structurally and functionally different. Seven highly conserved regions, representing approximately 47 amino acids (of 299) have been found. These regions are distributed throughout the protein and reflect ligand binding sites as well as regions proposed to be involved in the propagation of the cysteine-arginine change at position 112 to distant regions of the protein in the N- and C-terminal domains. Highly non-conserved regions are at the N- and C-terminal ends of the apoE protein.
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Affiliation(s)
- Carl Frieden
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri, 63110
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35
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Li W, Wang Y, Han Z, Luo C, Zhang C, Xiong J. Apolipoprotein e mutation and double filtration plasmapheresis therapy on a new Chinese patient with lipoprotein glomerulopathy. Kidney Blood Press Res 2014; 39:330-9. [PMID: 25300642 DOI: 10.1159/000355810] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/04/2014] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS Lipoprotein glomerulopathy (LPG) is a rare hereditary disease. In this study, we investigated the apoE mutation and the role of double filtration plasmapheresis therapy (DFPP) on a new Chinese patient with LPG. METHODS Renal biopsy was performed on this patient to allow a definitive diagnosis. The mutations in the coding sequence of apoE and the hereditary pedigree of this patient were investigated by DNA sequencing. The patient was treated with DFPP, and clinical parameters before and after DFPP were compared. RESULTS Two missense mutations were found in this patient: Cys112Arg and Arg25Cys. Arg25Cys was previously designated as APOE Kyoto. Family genotyping showed that Cys112Arg and Arg25Cys mutation were transmitted through his father and his mother, respectively. The patient's parents are healthy so far to date. Possibly there was a dose effect on apoE mutation induced LPG. Furthermore, DFPP treatment was first used on this patient and led to dramatic changes: Proteinuria and apo E values declined, and hemoglobin level increased significantly. CONCLUSION APOE Kyoto mutation was found in a new Chinese patient with LPG, accompanied by Cys112Arg. More cases and further functional experiments are needed to investigate the role of these two mutations together in LPG. DFPP is an effective therapeutic modality for improving NS in patients with LPG.
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Affiliation(s)
- Wencheng Li
- Department of Urology, Union Hospital, Tongji Medical College, Huazhong University of Science & Technology, Wuhan, China
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Abstract
The vast majority of Alzheimer's disease (AD) cases are late onset (LOAD), which is genetically complex with heritability estimates up to 80%. Apolipoprotein E (APOE) has been irrefutably recognized as the major genetic risk factor, with semidominant inheritance, for LOAD. Although the mechanisms that underlie the pathogenic nature of APOE in AD are still not completely understood, emerging data suggest that APOE contributes to AD pathogenesis through both amyloid-β (Aβ)-dependent and Aβ-independent pathways. Given the central role for APOE in the modulation of AD pathogenesis, many therapeutic strategies have emerged, including converting APOE conformation, regulating APOE expression, mimicking APOE peptides, blocking the APOE/Aβ interaction, modulating APOE lipidation state, and gene therapy. Accumulating evidence also suggests the utility of APOE genotyping in AD diagnosis, risk assessment, prevention, and treatment response.
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Affiliation(s)
- Jin-Tai Yu
- Department of Neurology, Qingdao Municipal Hospital, School of Medicine, Qingdao University, Qingdao 266071, China; ,
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Abstract
Serum amyloid A (SAA) represents an evolutionarily conserved family of inflammatory acute-phase proteins. It is also a major constituent of secondary amyloidosis. To understand its function and structural transition to amyloid, we determined a structure of human SAA1.1 in two crystal forms, representing a prototypic member of the family. Native SAA1.1 exists as a hexamer, with subunits displaying a unique four-helix bundle fold stabilized by its long C-terminal tail. Structure-based mutational studies revealed two positive-charge clusters, near the center and apex of the hexamer, that are involved in SAA association with heparin. The binding of high-density lipoprotein involves only the apex region of SAA and can be inhibited by heparin. Peptide amyloid formation assays identified the N-terminal helices 1 and 3 as amyloidogenic peptides of SAA1.1. Both peptides are secluded in the hexameric structure of SAA1.1, suggesting that the native SAA is nonpathogenic. Furthermore, dissociation of the SAA hexamer appears insufficient to initiate amyloidogenic transition, and proteolytic cleavage or removal of the C-terminal tail of SAA resulted in formation of various-sized structural aggregates containing ∼5-nm regular repeating protofibril-like units. The combined structural and functional studies provide mechanistic insights into the pathogenic contribution of glycosaminoglycan in SAA1.1-mediated AA amyloid formation.
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Stratikos E, Chroni A. A possible structural basis behind the pathogenic role of apolipoprotein E hereditary mutations associated with lipoprotein glomerulopathy. Clin Exp Nephrol 2013; 18:225-9. [PMID: 24149834 DOI: 10.1007/s10157-013-0886-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Accepted: 10/01/2013] [Indexed: 01/18/2023]
Abstract
Single amino acid mutations in apolipoprotein E (apoE) have been associated with the development of the rare kidney disease lipoprotein glomerulopathy (LPG). Although the genetic linkage to disease development is well established, the mechanism of pathogenesis is largely unknown, limiting therapeutic insight. Here, we summarize current knowledge in the field and focus on the possible effects of LPG-associated mutations on the structure of apoE. Recent findings have suggested that mutation-induced folding perturbations in apoE lead to structural destabilization and aggregation, effects that may underlie lipoprotein thrombi accumulation in the glomerulus, a hallmark of LPG. The recognition that structural destabilization may underlie the association between apoE mutations and LPG can be key for development of new innovative treatments for this rare disease.
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Affiliation(s)
- Efstratios Stratikos
- National Center for Scientific Research Demokritos, Patriarhou Gregoriou and Neapoleos Street, 15310, Agia Paraskevi, Greece,
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39
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Frieden C, Garai K. Concerning the structure of apoE. Protein Sci 2013; 22:1820-5. [PMID: 24115173 DOI: 10.1002/pro.2379] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Accepted: 09/12/2013] [Indexed: 12/16/2022]
Abstract
Apolipoprotein E (apoE), first described in 1973, is a truly fascinating protein. While studies initially focused on its role in cholesterol and lipid metabolism, one apoE isoform (apoE4) is a major risk factor for development of late onset Alzheimer's disease. Yet the difference between apoE3, the common form, and apoE4 is a single amino acid of the 299 in this 34 kDa protein. Structure determination of the two domain full length apoE3 protein was only accomplished in 2011 and supports the notion that mutations in the N-terminal domain can be propagated through the structure to the C-terminal domain. Understanding the structural differences between apoE3 and apoE4 is critical for finding ways to modulate the deleterious effect of apoE4.
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Affiliation(s)
- Carl Frieden
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri, 63110
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40
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Hung YH, Bush AI, La Fontaine S. Links between copper and cholesterol in Alzheimer's disease. Front Physiol 2013; 4:111. [PMID: 23720634 PMCID: PMC3655288 DOI: 10.3389/fphys.2013.00111] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Accepted: 04/30/2013] [Indexed: 01/01/2023] Open
Abstract
Altered copper homeostasis and hypercholesterolemia have been identified independently as risk factors for Alzheimer's disease (AD). Abnormal copper and cholesterol metabolism are implicated in the genesis of amyloid plaques and neurofibrillary tangles (NFT), which are two key pathological signatures of AD. Amyloidogenic processing of a sub-population of amyloid precursor protein (APP) that produces Aβ occurs in cholesterol-rich lipid rafts in copper deficient AD brains. Co-localization of Aβ and a paradoxical high concentration of copper in lipid rafts fosters the formation of neurotoxic Aβ:copper complexes. These complexes can catalytically oxidize cholesterol to generate H2O2, oxysterols and other lipid peroxidation products that accumulate in brains of AD cases and transgenic mouse models. Tau, the core protein component of NFTs, is sensitive to interactions with copper and cholesterol, which trigger a cascade of hyperphosphorylation and aggregation preceding the generation of NFTs. Here we present an overview of copper and cholesterol metabolism in the brain, and how their integrated failure contributes to development of AD.
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Affiliation(s)
- Ya Hui Hung
- Oxidation Biology Laboratory, Florey Institute of Neuroscience and Mental Health Parkville, VIC, Australia ; Centre for Neuroscience Research, The University of Melbourne Parkville, VIC, Australia
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41
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Tran TN, Kim SH, Gallo C, Amaya M, Kyees J, Narayanaswami V. Biochemical and biophysical characterization of recombinant rat apolipoprotein E: similarities to human apolipoprotein E3. Arch Biochem Biophys 2012; 529:18-25. [PMID: 23103361 DOI: 10.1016/j.abb.2012.10.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2012] [Revised: 10/12/2012] [Accepted: 10/13/2012] [Indexed: 11/28/2022]
Abstract
Apolipoprotein E (apoE) is an anti-atherogenic protein that plays a critical role in maintaining plasma cholesterol and triglyceride homeostasis by virtue of its ability to act as a ligand for the low-density lipoprotein receptor (LDLr) family of proteins. In this study, we characterized the biochemical and biophysical features of recombinant rat apoE, in comparison with those of human apoE3. Rat apoE was overexpressed in Escherichia coli using a codon optimized system and purified by affinity chromatography. SDS-PAGE and RP-HPLC of rat apoE confirmed the purity, while immunoblot verified the identity and cross-reactivity with the LDLr-binding region of apoE3. The α-helical content was calculated to be ~45% by circular dichroism spectroscopy. The protein exists in a predominantly tetrameric form in lipid-free state. Chemical denaturation studies reveal that the unfolding pattern is biphasic with mid points of denaturation corresponding to 0.8 and 2.2 M guanidine hydrochloride, suggesting the presence of two domains. Rat apoE converts DMPC vesicles to smaller DMPC/apoE complexes with a first order rate constant of 0.12 min(-1). It has the ability to bind the LDLr and to heparin. Our studies indicate that although its sequence resembles apoE4, an isoform of apoE3, rat apoE displays the biophysical behavior of apoE3.
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Affiliation(s)
- Tuyen N Tran
- Department of Chemistry and Biochemistry, 1250 Bellflower Boulevard, California State University Long Beach, Long Beach, CA 90840, USA
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42
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Topology of human apolipoprotein E3 uniquely regulates its diverse biological functions. Proc Natl Acad Sci U S A 2011; 108:14813-8. [PMID: 21873229 DOI: 10.1073/pnas.1106420108] [Citation(s) in RCA: 172] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Human apolipoprotein E (apoE) is one of the major determinants in lipid transport, playing a critical role in atherosclerosis and other diseases. Binding to lipid and heparan sulfate proteoglycans (HSPG) induces apoE to adopt active conformations for binding to low-density lipoprotein receptor (LDLR) family. ApoE also interacts with beta amyloid peptide, manifests critical isoform-specific effects on Alzheimer's disease. Despite the importance of apoE in these major human diseases, the fundamental questions of how apoE adjusts its structure upon binding to regulate its diverse functions remain unsolved. We report the NMR structure of apoE3, displaying a unique topology of three structural domains. The C-terminal domain presents a large exposed hydrophobic surface that likely initiates interactions with lipids, HSPG, and beta amyloid peptides. The unique topology precisely regulates apoE tertiary structure to permit only one possible conformational adaptation upon binding and provides a double security in preventing lipid-free and partially-lipidated apoE from premature binding to apoE receptors during receptor biogenesis. This topology further ensures the optimal receptor-binding activity by the fully lipidated apoE during lipoprotein transport in circulation and in the brain. These findings provide a structural framework for understanding the structural basis of the diverse functions of this important protein in human diseases.
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43
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Chen J, Wang J. A segmental labeling strategy for unambiguous determination of domain-domain interactions of large multi-domain proteins. JOURNAL OF BIOMOLECULAR NMR 2011; 50:403-10. [PMID: 21732209 DOI: 10.1007/s10858-011-9526-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2011] [Accepted: 06/16/2011] [Indexed: 05/19/2023]
Abstract
NMR structural determination of large multi-domain proteins is a challenging task due to significant spectral overlap with a particular difficulty in unambiguous identification of domain-domain interactions. Segmental labeling is a NMR strategy that allows for isotopically labeling one domain and leaves the other domain unlabeled. This significantly simplifies spectral overlaps and allows for quick identification of domain-domain interaction. Here, a novel segmental labeling strategy is presented for detection of inter-domain NOEs. To identify domain-domain interactions in human apolipoprotein E (apoE), a multi-domain, 299-residues α-helical protein, on-column expressed protein ligation was utilized to generate a segmental-labeled apoE samples in which the N-terminal (NT-) domain was (2)H(99%)/(15)N-labeled whereas the C-terminal (CT-) domain was either (15)N- or (15)N/(13)C-labeled. 3-D (15)N-edited NOESY spectra of these segmental-labeled apoE samples allow for direct observation of the inter-domain NOEs between the backbone amide protons of the NT-domain and the aliphatic protons of the CT-domain. This straightforward approach permits unambiguous identification of 78 inter-domain NOEs, enabling accurate definition of the relative positions of both the NT- and the CT-domains and determination of the NMR structure of apoE.
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Affiliation(s)
- Jianglei Chen
- Department of Biochemistry and Molecular Biology, School of Medicine, Wayne State University, Detroit, MI 48201, USA
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Petropoulou PA, Gantz DL, Wang Y, Rensen PCN, Kypreos KE. The aminoterminal 1-185 domain of human apolipoprotein E suffices for the de novo biogenesis of apoE-containing HDL-like particles in apoA-I deficient mice. Atherosclerosis 2011; 219:116-23. [PMID: 21802082 DOI: 10.1016/j.atherosclerosis.2011.06.057] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2011] [Revised: 06/20/2011] [Accepted: 06/30/2011] [Indexed: 10/18/2022]
Abstract
AIMS Recently we showed that apolipoprotein E promotes the de novo biogenesis of apoE-containing HDL particles in a process that requires the function of the lipid transporter ABCA1. Here, we sought to identify the domain of apoE that is responsible for its functional interactions with ABCA1 and the formation of apoE-rich HDL-like particles. METHODS AND RESULTS Recombinant attenuated adenoviruses expressing carboxy-terminal truncated forms of apoE4 (apoE4[1-259], apoE4[1-229], apoE4[1-202], and apoE4[1-185]) were administered to apoA-I-deficient mice at a low dose of 8×10(8) pfu and five days post-infection plasma samples were isolated and analyzed for HDL formation. Fractionation of plasma lipoproteins of the infected mice by density gradient ultracentrifugation and FPLC revealed that all forms were capable of promoting HDL formation. Negative staining electron microscopy analysis of the HDL density fractions confirmed that all C-terminal truncated forms of apoE4 promoted the formation of particles with diameters in the HDL region. Interestingly, apoE4[1-259], apoE4[1-229], and apoE4[1-202] led to the formation of spherical particles while plasma from apoE4[1-185] expressing mice contained a mixture of spherical and discoidal particles. CONCLUSIONS Taken together, our data establish that the aminoterminal 1-185 region of apoE suffices for the formation of HDL particles in vivo. Our findings may have important ramifications in the design of new biological drugs for the treatment of dyslipidemia, atherosclerosis and coronary heart disease.
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Abstract
The mechanism by which apolipoprotein E (ApoE) isoforms functionally influence the risk and progression of late-onset Alzheimer's disease (LOAD) remains hitherto unknown. Herein, we present evidence that all ApoE isoforms bind to nitric oxide synthase 1 (NOS1) and that such protein-protein interaction results in S-nitrosylation of ApoE2 and ApoE3 but not ApoE4. Our structural analysis at the atomic level reveals that S-nitrosylation of ApoE2 and ApoE3 proteins may lead to conformational changes resulting in the loss of binding to low-density lipoprotein (LDL) receptors. Collectively, our data suggest that S-nitrosylation of ApoE proteins may play an important role in regulating lipid metabolism and in the pathogenesis of LOAD.
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Affiliation(s)
- Alexander J. Abrams
- John P. Hussman Institute for Human Genomics, Dr. John T. Macdonald Foundation Department of Human Genetics, University of Miami Miller School of Medicine, Miami, FL 33136
| | - Amjad Farooq
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, FL 33136
| | - Gaofeng Wang
- John P. Hussman Institute for Human Genomics, Dr. John T. Macdonald Foundation Department of Human Genetics, University of Miami Miller School of Medicine, Miami, FL 33136
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46
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Reis KA, Ebinç FA, Koç E, Demirci H, Erten Y, Güz G, Derici ÜB, Bali M, Söylemezoğlu O, Arınsoy T, Sindel Ş. Association of the Angiotensinogen M235T and APO E Gene Polymorphisms in Turkish Type 2 Diabetic Patients with and without Nephropathy. Ren Fail 2011; 33:469-74. [DOI: 10.3109/0886022x.2011.568133] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Hauser PS, Narayanaswami V, Ryan RO. Apolipoprotein E: from lipid transport to neurobiology. Prog Lipid Res 2010; 50:62-74. [PMID: 20854843 DOI: 10.1016/j.plipres.2010.09.001] [Citation(s) in RCA: 216] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2010] [Revised: 09/04/2010] [Accepted: 09/12/2010] [Indexed: 12/17/2022]
Abstract
Apolipoprotein (apo) E has a storied history as a lipid transport protein. The integral association between cholesterol homeostasis and lipoprotein clearance from circulation are intimately related to apoE's function as a ligand for cell-surface receptors of the low-density lipoprotein receptor family. The receptor binding properties of apoE are strongly influenced by isoform specific amino acid differences as well as the lipidation state of the protein. As understanding of apoE as a structural component of circulating plasma lipoproteins has evolved, exciting developments in neurobiology have revitalized interest in apoE. The strong and enduring correlation between the apoE4 isoform and age of onset and increased risk of Alzheimer's disease has catapulted apoE to the forefront of neurobiology. Using genetic tools generated for study of apoE lipoprotein metabolism, transgenic "knock-in" and gene-disrupted mice are now favored models for study of its role in a variety of neurodegenerative diseases. Key structural knowledge of apoE and isoform-specific differences is driving research activity designed to elucidate how a single amino acid change can manifest such profoundly significant pathological consequences. This review describes apoE through a lens of structure-based knowledge that leads to hypotheses that attempt to explain the functions of apoE and isoform-specific effects relating to disease mechanism.
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Affiliation(s)
- Paul S Hauser
- Center for Prevention of Obesity, Cardiovascular Disease and Diabetes, Children's Hospital Oakland Research Institute, 5700 Martin Luther King Jr. Way, Oakland, CA 94609, USA
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48
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Patel AB, Khumsupan P, Narayanaswami V. Pyrene fluorescence analysis offers new insights into the conformation of the lipoprotein-binding domain of human apolipoprotein E. Biochemistry 2010; 49:1766-75. [PMID: 20073510 DOI: 10.1021/bi901902e] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The C-terminal domain (CT) of apolipoprotein E (apoE), a critical protein involved in cholesterol transport in the plasma and brain, plays an important role in high-affinity lipoprotein binding. Although high-resolution structural information is available for the N-terminal domain of apoE, the structural organization of the CT (residues 201-299) is largely unknown. In this study, we employ site-specific fluorescence labeling with pyrene maleimide to gain insight into the structure and conformation of apoE CT in its naturally self-associated state in buffer at physiologically relevant concentrations (5-50 microg/mL). Pyrene is a highly sensitive fluorophore that reports on spatial proximity between desired sites by displaying unique spectral features. Pyrene was covalently attached to single cysteine-containing recombinant human apoE CT at position 223 or 255 to probe the first predicted helical segment and at position 277 to monitor the terminal predicted helical segment. Regardless of the location of the probe, all three pyrene-labeled apoE CT variants display an intense and dramatic fluorescence excimer band at 460 nm, a signature feature of pyrene, which indicates that two pyrene moieties are within 10 A of each other. In addition, an intense peak at 387 nm (indicative of a highly hydrophobic environment) was noted in all cases. Fluorescence emission quenching by potassium iodide indicates that the accessibility to the probes was restricted at these locations. The possibility that the hydrophobicity of the pyrene moiety was the driving force for helix-helix interaction was excluded because pyrene located at position 209, which is predicted to be located in a nonhelical segment, did not display the above intense unique features. Lastly, denaturation studies suggest that the terminal helix unfolds prior to the first predicted helix in apoE CT. Our studies indicate that there are extensive intermolecular helix-helix contacts throughout the entire CT in the lipid-free state with two apoE CT molecules oriented parallel to each other to form a dimer, which dimerizes further to yield a tetramer. Such an organization allows helix-helix interactions to be replaced by helix-lipid interactions upon encountering a lipoprotein surface, with the terminal helix likely initiating the binding interaction. This study presents the possibility of employing pyrene fluorophores as powerful new alternatives to obtain conformational information of proteins at physiologically relevant concentrations.
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Affiliation(s)
- Arti B Patel
- Department of Chemistry and Biochemistry, 1250 Bellflower Boulevard, California State University Long Beach, Long Beach, California 90840, USA
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49
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Abstract
High density lipoprotein (HDL) possesses important anti-atherogenic properties and this review addresses the molecular mechanisms underlying these functions. The structures and cholesterol transport abilities of HDL particles are determined by the properties of their exchangeable apolipoprotein (apo) components. ApoA-I and apoE, which are the best characterized in structural terms, contain a series of amphipathic alpha-helical repeats. The helices located in the amino-terminal two-thirds of the molecule adopt a helix bundle structure while the carboxy-terminal segment forms a separately folded, relatively disorganized, domain. The latter domain initiates lipid binding and this interaction induces changes in conformation; the alpha-helix content increases and the amino-terminal helix bundle can open subsequently. These conformational changes alter the abilities of apoA-I and apoE to function as ligands for their receptors. The apoA-I and apoE molecules possess detergent-like properties and they can solubilize vesicular phospholipid to create discoidal HDL particles with hydrodynamic diameters of ~10 nm. In the case of apoA-I, such a particle is stabilized by two protein molecules arranged in an anti-parallel, double-belt, conformation around the edge of the disc. The abilities of apoA-I and apoE to solubilize phospholipid and stabilize HDL particles enable these proteins to be partners with ABCA1 in mediating efflux of cellular phospholipid and cholesterol, and the biogenesis of HDL particles. ApoA-I-containing nascent HDL particles play a critical role in cholesterol transport in the circulation whereas apoE-containing HDL particles mediate cholesterol transport in the brain. The mechanisms by which HDL particles are remodeled by lipases and lipid transfer proteins, and interact with SR-BI to deliver cholesterol to cells, are reviewed.
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50
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Narayanaswami V, Kiss RS, Weers PMM. The helix bundle: a reversible lipid binding motif. Comp Biochem Physiol A Mol Integr Physiol 2009; 155:123-33. [PMID: 19770066 DOI: 10.1016/j.cbpa.2009.09.009] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2009] [Revised: 09/09/2009] [Accepted: 09/11/2009] [Indexed: 01/01/2023]
Abstract
Apolipoproteins are the protein components of lipoproteins that have the innate ability to inter convert between a lipid-free and a lipid-bound form in a facile manner, a remarkable property conferred by the helix bundle motif. Composed of a series of four or five amphipathic alpha-helices that fold to form a helix bundle, this motif allows the en face orientation of the hydrophobic faces of the alpha-helices in the protein interior in the lipid-free state. A conformational switch then permits helix-helix interactions to be substituted by helix-lipid interactions upon lipid binding interaction. This review compares the apolipoprotein high-resolution structures and the factors that trigger this switch in insect apolipophorin III and the mammalian apolipoproteins, apolipoprotein E and apolipoprotein A-I, pointing out the commonalities and key differences in the mode of lipid interaction. Further insights into the lipid-bound conformation of apolipoproteins are required to fully understand their functional role under physiological conditions.
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Affiliation(s)
- Vasanthy Narayanaswami
- Department of Chemistry and Biochemistry, California State University Long Beach, Long Beach CA 90840, USA
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