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Wu H, Xie J, Peng W, Ji F, Qian J, Shen Q, Hou G. Effects of guanidinoacetic acid supplementation on liver and breast muscle fat deposition, lipid levels, and lipid metabolism-related gene expression in ducks. Front Vet Sci 2024; 11:1364815. [PMID: 38435369 PMCID: PMC10904544 DOI: 10.3389/fvets.2024.1364815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Accepted: 02/02/2024] [Indexed: 03/05/2024] Open
Abstract
Exogenous supplementation of guanidinoacetic acid can mechanistically regulate the energy distribution in muscle cells. This study aimed to investigate the effects of guanidinoacetic acid supplementation on liver and breast muscle fat deposition, lipid levels, and lipid metabolism-related gene expression in ducks. We randomly divided 480 42 days-old female Jiaji ducks into four groups with six replicates and 20 ducks for each replicate. The control group was fed the basal diet, and the experimental groups were fed the basal diet with 400, 600, and 800 mg/kg (GA400, GA600, and GA800) guanidinoacetic acid, respectively. Compared with the control group, (1) the total cholesterol (p = 0.0262), triglycerides (p = 0.0357), malondialdehyde (p = 0.0452) contents were lower in GA400, GA600 and GA800 in the liver; (2) the total cholesterol (p = 0.0365), triglycerides (p = 0.0459), and malondialdehyde (p = 0.0326) contents in breast muscle were decreased in GA400, GA600 and GA800; (3) the high density lipoprotein (p = 0.0356) and apolipoprotein-A1 (p = 0.0125) contents were increased in GA600 in the liver; (4) the apolipoprotein-A1 contents (p = 0.0489) in breast muscle were higher in GA600 and GA800; (5) the lipoprotein lipase contents (p = 0.0325) in the liver were higher in GA600 and GA800; (6) the malate dehydrogenase contents (p = 0.0269) in breast muscle were lower in GA400, GA600, and GA800; (7) the insulin induced gene 1 (p = 0.0326), fatty acid transport protein 1 (p = 0.0412), and lipoprotein lipase (p = 0.0235) relative expression were higher in GA400, GA600, and GA800 in the liver; (8) the insulin induced gene 1 (p = 0.0269), fatty acid transport protein 1 (p = 0.0234), and lipoprotein lipase (p = 0.0425) relative expression were increased in GA400, GA600, and GA800 in breast muscle. In this study, the optimum dosage of 600 mg/kg guanidinoacetic acid improved the liver and breast muscle fat deposition, lipid levels, and lipid metabolism-related gene expression in ducks.
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Affiliation(s)
- Hongzhi Wu
- Tropical Crop Genetic Resource Research Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou, China
| | - Jiajun Xie
- College of Animal Science and Technology, Northeast Agricultural University, Harbin, China
| | - Weiqi Peng
- Tropical Crop Genetic Resource Research Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou, China
| | - Fengjie Ji
- Tropical Crop Genetic Resource Research Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou, China
| | - Jinyu Qian
- Tropical Crop Genetic Resource Research Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou, China
| | - Qian Shen
- Hainan Xuhuai Technology Co., Ltd., Haikou, China
| | - Guanyu Hou
- Tropical Crop Genetic Resource Research Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou, China
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Liu K, Nilsson R, Lázaro-Ibáñez E, Duàn H, Miliotis T, Strimfors M, Lerche M, Salgado Ribeiro AR, Ulander J, Lindén D, Salvati A, Sabirsh A. Multiomics analysis of naturally efficacious lipid nanoparticle coronas reveals high-density lipoprotein is necessary for their function. Nat Commun 2023; 14:4007. [PMID: 37414857 PMCID: PMC10325984 DOI: 10.1038/s41467-023-39768-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 06/27/2023] [Indexed: 07/08/2023] Open
Abstract
In terms of lipid nanoparticle (LNP) engineering, the relationship between particle composition, delivery efficacy, and the composition of the biocoronas that form around LNPs, is poorly understood. To explore this we analyze naturally efficacious biocorona compositions using an unbiased screening workflow. First, LNPs are complexed with plasma samples, from individual lean or obese male rats, and then functionally evaluated in vitro. Then, a fast, automated, and miniaturized method retrieves the LNPs with intact biocoronas, and multiomics analysis of the LNP-corona complexes reveals the particle corona content arising from each individual plasma sample. We find that the most efficacious LNP-corona complexes were enriched with high-density lipoprotein (HDL) and, compared to the commonly used corona-biomarker Apolipoprotein E, corona HDL content was a superior predictor of in-vivo activity. Using technically challenging and clinically relevant lipid nanoparticles, these methods reveal a previously unreported role for HDL as a source of ApoE and, form a framework for improving LNP therapeutic efficacy by controlling corona composition.
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Affiliation(s)
- Kai Liu
- Advanced Drug Delivery, Pharmaceutical Sciences, R&D, AstraZeneca, Gothenburg, Sweden
| | - Ralf Nilsson
- Translational Science and Experimental Medicine, Research and Early Development, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Elisa Lázaro-Ibáñez
- Advanced Drug Delivery, Pharmaceutical Sciences, R&D, AstraZeneca, Gothenburg, Sweden
| | - Hanna Duàn
- Advanced Drug Delivery, Pharmaceutical Sciences, R&D, AstraZeneca, Gothenburg, Sweden
| | - Tasso Miliotis
- Translational Science and Experimental Medicine, Research and Early Development, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Marie Strimfors
- Bioscience Metabolism, Research and Early Development, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Michael Lerche
- Advanced Drug Delivery, Pharmaceutical Sciences, R&D, AstraZeneca, Gothenburg, Sweden
| | | | - Johan Ulander
- Data Science and Modelling, Pharmaceutical Sciences, R&D, AstraZeneca, Gothenburg, Sweden
| | - Daniel Lindén
- Bioscience Metabolism, Research and Early Development, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
- Division of Endocrinology, Department of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Anna Salvati
- Department of Nanomedicine & Drug Targeting, Groningen Research Institute of Pharmacy, University of Groningen, Groningen, 9713AV, The Netherlands
| | - Alan Sabirsh
- Advanced Drug Delivery, Pharmaceutical Sciences, R&D, AstraZeneca, Gothenburg, Sweden.
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Yu X, Jin T, Wang K, Li D, Cheng L. Benchmark studies on the large errors of calculated binding energies in metallophilic interactions. J Chem Phys 2022; 156:104103. [DOI: 10.1063/5.0085213] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Xinlei Yu
- Anhui University - Qingyuan Campus, China
| | - Tong Jin
- Anhui University - Qingyuan Campus, China
| | - Kun Wang
- Anhui University - Qingyuan Campus, China
| | - Dan Li
- Anhui University - Qingyuan Campus, China
| | - Longjiu Cheng
- Department of Chemistry, Anhui University College of Chemistry and Chemical Engineering, China
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4
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Ma YY, Yu YQ, Cheng LJ. Electronic stability of bimetallic Au2@Cu6 nanocluster: Closed-shell interaction and multicenter bonding. CHINESE J CHEM PHYS 2020. [DOI: 10.1063/1674-0068/cjcp1912200] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Ying-ying Ma
- Department of Chemistry, Anhui University, Hefei 230601, China
| | - Yuan-qin Yu
- School of Physics and Materials Science, Anhui University, Hefei 230601, China
| | - Long-jiu Cheng
- Department of Chemistry, Anhui University, Hefei 230601, China
- Anhui Province Key Laboratory of Chemistry for Inorganic/Organic Hybrid Functionalized Materials, Anhui University, Hefei 230601, China
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Tai LM, Ghura S, Koster KP, Liakaite V, Maienschein‐Cline M, Kanabar P, Collins N, Ben‐Aissa M, Lei AZ, Bahroos N, Green SJ, Hendrickson B, Van Eldik LJ, LaDu MJ. APOE-modulated Aβ-induced neuroinflammation in Alzheimer's disease: current landscape, novel data, and future perspective. J Neurochem 2015; 133:465-88. [PMID: 25689586 PMCID: PMC4400246 DOI: 10.1111/jnc.13072] [Citation(s) in RCA: 103] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 02/10/2015] [Accepted: 02/11/2015] [Indexed: 01/12/2023]
Abstract
Chronic glial activation and neuroinflammation induced by the amyloid-β peptide (Aβ) contribute to Alzheimer's disease (AD) pathology. APOE4 is the greatest AD-genetic risk factor; increasing risk up to 12-fold compared to APOE3, with APOE4-specific neuroinflammation an important component of this risk. This editorial review discusses the role of APOE in inflammation and AD, via a literature review, presentation of novel data on Aβ-induced neuroinflammation, and discussion of future research directions. The complexity of chronic neuroinflammation, including multiple detrimental and beneficial effects occurring in a temporal and cell-specific manner, has resulted in conflicting functional data for virtually every inflammatory mediator. Defining a neuroinflammatory phenotype (NIP) is one way to address this issue, focusing on profiling the changes in inflammatory mediator expression during disease progression. Although many studies have shown that APOE4 induces a detrimental NIP in peripheral inflammation and Aβ-independent neuroinflammation, data for APOE-modulated Aβ-induced neuroinflammation are surprisingly limited. We present data supporting the hypothesis that impaired apoE4 function modulates Aβ-induced effects on inflammatory receptor signaling, including amplification of detrimental (toll-like receptor 4-p38α) and suppression of beneficial (IL-4R-nuclear receptor) pathways. To ultimately develop APOE genotype-specific therapeutics, it is critical that future studies define the dynamic NIP profile and pathways that underlie APOE-modulated chronic neuroinflammation. In this editorial review, we present data supporting the hypothesis that impaired apoE4 function modulates Aβ-induced effects on inflammatory receptor signaling, including amplification of detrimental (TLR4-p38α) and suppression of beneficial (IL-4R-nuclear receptor) pathways, resulting in an adverse NIP that causes neuronal dysfunction. NIP, Neuroinflammatory phenotype; P.I., pro-inflammatory; A.I., anti-inflammatory.
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Affiliation(s)
- Leon M. Tai
- Department of Anatomy and Cell BiologyUniversity of IllinoisChicagoIllinoisUSA
| | - Shivesh Ghura
- Department of Anatomy and Cell BiologyUniversity of IllinoisChicagoIllinoisUSA
| | - Kevin P. Koster
- Department of Anatomy and Cell BiologyUniversity of IllinoisChicagoIllinoisUSA
| | | | | | - Pinal Kanabar
- UIC Center for Research Informatics University of IllinoisChicagoIllinoisUSA
| | - Nicole Collins
- Department of Anatomy and Cell BiologyUniversity of IllinoisChicagoIllinoisUSA
| | - Manel Ben‐Aissa
- Department of Anatomy and Cell BiologyUniversity of IllinoisChicagoIllinoisUSA
| | - Arden Zhengdeng Lei
- UIC Center for Research Informatics University of IllinoisChicagoIllinoisUSA
| | - Neil Bahroos
- UIC Center for Research Informatics University of IllinoisChicagoIllinoisUSA
| | | | - Bill Hendrickson
- UIC Research Resources CenterUniversity of IllinoisChicagoIllinoisUSA
| | | | - Mary Jo LaDu
- Department of Anatomy and Cell BiologyUniversity of IllinoisChicagoIllinoisUSA
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Lee CYD, Landreth GE. The role of microglia in amyloid clearance from the AD brain. J Neural Transm (Vienna) 2010; 117:949-60. [PMID: 20552234 DOI: 10.1007/s00702-010-0433-4] [Citation(s) in RCA: 470] [Impact Index Per Article: 33.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2010] [Accepted: 05/26/2010] [Indexed: 12/22/2022]
Abstract
Alzheimer's disease (AD), the most prominent cause of senile dementia, is clinically characterized by the extracellular deposition of beta-amyloid (Abeta) and the intracellular neurofibrillary tangles. It has been well accepted that AD pathogenesis arises from perturbation in the homeostasis of Abeta in the brain. Abeta is normally produced at high levels in the brain and cleared in an equivalent rate. Thus, even a moderate decrease in the clearance leads to the accumulation of Abeta and subsequent amyloid deposition. Microglia are the tissue macrophages in the central nervous system (CNS) and have been shown to play major roles in internalization and degradation of Abeta. Abeta exists in the brain both in soluble and in fibrillar forms. Microglia interact with these two forms of Abeta in different ways. They take up soluble forms of Abeta through macropinocytosis and LDL receptor-related proteins (LRPs) mediated pathway. Fibrillar forms of Abeta interact with the cell surface innate immune receptor complex, initiating intracellular signaling cascades that stimulate phagocytosis. Inflammatory responses influence the activation status of microglia and subsequently regulate their ability to take up and degrade Abeta. ApoE and its receptors have been shown to play critical roles in these processes. In this review, we will explore the mechanisms that microglia utilize to clear Abeta and the effectors that modulate the processes.
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Affiliation(s)
- C Y Daniel Lee
- School of Medicine, Case Western Reserve University, SOM E649, 10900 Euclid Avenue, Cleveland, OH 44106-4928, USA.
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Kim J, Basak JM, Holtzman DM. The role of apolipoprotein E in Alzheimer's disease. Neuron 2009; 63:287-303. [PMID: 19679070 PMCID: PMC3044446 DOI: 10.1016/j.neuron.2009.06.026] [Citation(s) in RCA: 1051] [Impact Index Per Article: 70.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2009] [Revised: 06/22/2009] [Accepted: 06/25/2009] [Indexed: 01/17/2023]
Abstract
The epsilon4 allele of apolipoprotein E (APOE) is the major genetic risk factor for Alzheimer's disease (AD). Although there have been numerous studies attempting to elucidate the underlying mechanism for this increased risk, how apoE4 influences AD onset and progression has yet to be proven. However, prevailing evidence suggests that the differential effects of apoE isoforms on Abeta aggregation and clearance play the major role in AD pathogenesis. Other potential mechanisms, such as the differential modulation of neurotoxicity and tau phosphorylation by apoE isoforms as well as its role in synaptic plasticity and neuroinflammation, have not been ruled out. Inconsistent results among studies have made it difficult to define whether the APOE epsilon4 allele represents a gain of toxic function, a loss of neuroprotective function, or both. Therapeutic strategies based on apoE propose to reduce the toxic effects of apoE4 or to restore the physiological, protective functions of apoE.
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Affiliation(s)
- Jungsu Kim
- Department of Neurology, Developmental Biology, Hope Center for Neurological Disorders, Alzheimer's Disease Research Center, Washington University School of Medicine, St. Louis, MO 63110, USA
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8
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Jiang Q, Lee CYD, Mandrekar S, Wilkinson B, Cramer P, Zelcer N, Mann K, Lamb B, Willson TM, Collins JL, Richardson JC, Smith JD, Comery TA, Riddell D, Holtzman DM, Tontonoz P, Landreth GE. ApoE promotes the proteolytic degradation of Abeta. Neuron 2008; 58:681-93. [PMID: 18549781 DOI: 10.1016/j.neuron.2008.04.010] [Citation(s) in RCA: 662] [Impact Index Per Article: 41.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2007] [Revised: 01/19/2008] [Accepted: 04/08/2008] [Indexed: 10/22/2022]
Abstract
Apolipoprotein E is associated with age-related risk for Alzheimer's disease and plays critical roles in Abeta homeostasis. We report that ApoE plays a role in facilitating the proteolytic clearance of soluble Abeta from the brain. The endolytic degradation of Abeta peptides within microglia by neprilysin and related enzymes is dramatically enhanced by ApoE. Similarly, Abeta degradation extracellularly by insulin-degrading enzyme is facilitated by ApoE. The capacity of ApoE to promote Abeta degradation is dependent upon the ApoE isoform and its lipidation status. The enhanced expression of lipidated ApoE, through the activation of liver X receptors, stimulates Abeta degradation. Indeed, aged Tg2576 mice treated with the LXR agonist GW3965 exhibited a dramatic reduction in brain Abeta load. GW3965 treatment also reversed contextual memory deficits. These data demonstrate a mechanism through which ApoE facilitates the clearance of Abeta from the brain and suggest that LXR agonists may represent a novel therapy for AD.
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Affiliation(s)
- Qingguang Jiang
- Alzheimer Research Laboratory, Department of Neurosciences, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
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9
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Hofmann SM, Zhou L, Perez-Tilve D, Greer T, Grant E, Wancata L, Thomas A, Pfluger PT, Basford JE, Gilham D, Herz J, Tschöp MH, Hui DY. Adipocyte LDL receptor-related protein-1 expression modulates postprandial lipid transport and glucose homeostasis in mice. J Clin Invest 2008; 117:3271-82. [PMID: 17948131 DOI: 10.1172/jci31929] [Citation(s) in RCA: 126] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2007] [Accepted: 08/01/2007] [Indexed: 12/13/2022] Open
Abstract
Diet-induced obesity and its serious consequences such as diabetes, cardiovascular disease, and cancer are rapidly becoming a major global health threat. Therefore, understanding the cellular and molecular mechanisms by which dietary fat causes obesity and diabetes is of paramount importance in order to identify preventive and therapeutic strategies. Increased dietary fat intake results in high plasma levels of triglyceride-rich lipoproteins (TGRL). Tissue uptake of TGRL has been shown to promote glucose intolerance. We generated mice with an adipocyte-specific inactivation of the multifunctional receptor LDL receptor-related protein-1 (LRP1) to determine its role in mediating the effects of TGRL on diet-induced obesity and diabetes. Knockout mice displayed delayed postprandial lipid clearance, reduced body weight, smaller fat stores, lipid-depleted brown adipocytes, improved glucose tolerance, and elevated energy expenditure due to enhanced muscle thermogenesis. We further demonstrated that inactivation of adipocyte LRP1 resulted in resistance to dietary fat-induced obesity and glucose intolerance. These findings identify LRP1 as a critical regulator of adipocyte energy homeostasis, where functional disruption leads to reduced lipid transport, increased insulin sensitivity, and muscular energy expenditure.
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Affiliation(s)
- Susanna M Hofmann
- Department of Pathology, University of Cincinnati College of Medicine, Cincinnati, Ohio 45237, USA
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Dergunov AD, Novoselov AV, Visvikis S, Siest G, Yakushkin VV, Tsibulsky V. The composition, structural properties and binding of very-low-density and low-density lipoproteins to the LDL receptor in normo- and hypertriglyceridemia: relation to the apolipoprotein E phenotype. Biol Chem 2005; 386:441-52. [PMID: 15927888 DOI: 10.1515/bc.2005.053] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The composition, apolipoprotein structure and lipoprotein binding to the LDL receptor were studied for very-low-density (VLDL) and low-density lipoprotein (LDL) particles isolated from subjects with apoE phenotype E3/3 (E3), E2/2 or E2/3 (E2+) and E3/4 or E4/4 (E4+) and a wide range of plasma triglyceride (TG) contents. The data combined for all three phenotype groups can be summarized as follows. (i) A decrease in accessibility of VLDL tryptophan residues to I- anions with a decrease in tryptophan surface density, concomitant with an increase in VLDL dimensions, reflects the increased efficiency of protein-protein interactions. (ii) A gradual increase in the quenching constant for LDL apoB fluorescence with an increase in TG/cholesterol (Chol) ratio reflects the 'freezing' effect of Chol molecules on apoB dynamics. (iii) Different mechanisms specific for a particular lipoprotein from E3/3 or E2/3 subjects are responsible for apoE-mediated VLDL binding and apoB-mediated LDL binding to the LDL receptor in a solid-phase binding assay. (iv) The 'spacing' effect of apoC-III molecules on apoE-mediated VLDL binding results in a decrease in the number of binding sites. (v) The maximum of the dependence of the LDL binding affinity constant on relative tryptophan density corresponds to LDL intermediate size. VLDL particles from hypertriglyceridemic E2/3 heterozygotic individuals had remnant-like properties (increased cholesterol, apoE and decreased apoC-III content) while their binding efficiency was unchanged. Based on the affinity constant value and LDL-Chol content, increased competition between VLDL and LDL for the binding to the LDL receptor upon increase in plasma TG is suggested, and LDL from hypertriglyceridemic E3/3 homozygotic individuals is the most efficient competitor.
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Affiliation(s)
- Alexander D Dergunov
- National Research Center for Preventive Medicine, Petroverigsky Street 10, 101953 Moscow, Russia.
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Dergunov AD, Perova NV, Visvikis S, Siest G. Time-dependent lipid response on fluvastatin therapy of patients with hypercholesterolemia sensitive to apoE phenotype. Vascul Pharmacol 2003; 40:237-45. [PMID: 15259790 DOI: 10.1016/j.vph.2003.09.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Sixty-seven male patients with hypercholesterolemia, divided into three groups according to apolipoprotein E phenotype (33 with apoE3/ 3 phenotype, E3 group; 23 with 2/2 or 2/3, E2+ group; 11 with 4/4 or 4/3, E4+ group), received daily 20-40 mg of fluvastatin for 12 weeks. The levels of triglyceride (TG), cholesterol (Chol), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) were measured after 0, 4, 8 and 12 weeks on fluvastatin and after 4 weeks washout period. Lipid percentage changes (delta) were not associated with apoE phenotype for any treatment time. Cholesterol decreased by 14% after 12 weeks and HDL-C increased by 14-16% after 12 weeks for three phenotype groups. deltaTG, deltaChol, deltaLDL-C were associated positively, while negatively for deltaHDL-C, with the corresponding basal lipid values for the three groups. The positive deltaTG values occurred at a low basal TG0 level and became negative at TG0 > 1.6-1.9 mM. For E3 and E4+ groups, only a single parameter contributed significantly into a variation of lipid percentage changes. For the E2+ group, TG0 and Chol0 contributed in a reciprocal manner into deltaTG12/0, both positively into deltaChol8/0; Chol0 and HDL-C0 both negatively contributed into deltaHDL-C12/0. HDL-C0 contributed reciprocally into LDL-C variability for E2+ and E4+ groups. Three effects seem to contribute differently into lipid response among patients with different apoE phenotype: the inhibition of hepatic and lipoprotein lipase activities, the competition between TG-rich and low-density lipoproteins for LDL-receptor and the accumulation of intermediate-density lipoproteins in patients bearing E2 isoform.
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Affiliation(s)
- Alexander D Dergunov
- National Research Centre for Preventive Medicine, 10, Petroverigsky Street, 101953 Moscow, Russia.
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Dergunov AD, Hoy A, Smirnova EA, Visvikis S, Siest G. Charge-based heterogeneity of human plasma lipoproteins at hypertriglyceridemia: capillary isotachophoresis study. Int J Biochem Cell Biol 2003; 35:530-43. [PMID: 12565713 DOI: 10.1016/s1357-2725(02)00359-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
To reveal the metabolic links between and within pools of pro-atherogenic triglyceride(TG)-rich lipoproteins and anti-atherogenic high density lipoproteins (HDL), the changes in lipoprotein profile at hypertriglyceridemia were analyzed by capillary isotachophoresis. Plasma samples from patients with apoE3/3 phenotype were stained with a fluorescent probe NBD-C6-ceramide and lipoproteins resolved into six H-, one (V+I) and four L-components which belong to HDL, very low and intermediate density (VLDL+IDL) and low density lipoproteins (LDL), respectively. The expected correlation between the relative size of the combined fractions and lipid and apolipoprotein values was obtained confirming the validity of the approach. The new findings were obtained as follows. (1) The fast L-component correlated inversely with HDL-cholesterol (Chol), while intermediate and slow H-components correlated inversely with plasma and LDL-Chol and apoB. (2) The content of intermediate and slow H-components increased within H-pool and decreased relative TG-rich lipoproteins as hypertriglyceridemia rose due to the impairment of triglyceride hydrolysis by lipoprotein lipase within TG-rich particles. (3) A predictive value of the ratios of fast to slow H-components as an indicator of lecithin:cholesterol acyltransferase activity was demonstrated which tended to decrease at hypertriglyceridemia. (4) The L1/L2 ratio may be considered as an indicator of the accumulation of small dense LDL, which is a feature of clinically manifested atherogenic B-pattern. The competition between H(DL) and L(DL) particles for hepatic lipase and significant contribution of apoE to functional deficiency of H(DL) particles at hypertriglyceridemia are suggested.
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Affiliation(s)
- Alexander D Dergunov
- National Research Centre for Preventive Medicine, 10, Petroverigsky street, 101953, Moscow, Russia.
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Dergunov AD, Vorotnikova YY, Visvikis S, Siest G. Homo- and hetero-complexes of exchangeable apolipoproteins in solution and in lipid-bound form. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2003; 59:1127-1137. [PMID: 12633731 DOI: 10.1016/s1386-1425(02)00298-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The self-association state of human plasma apolipoprotein E (apoE) in solution and in complexes with dimyristoylphosphatidylcholine (DMPC) varying in stoichiometry was studied in sub-micromolar concentration range by gel filtration, fluorescence anisotropy, fluorescence quenching and energy transfer measurements with apolipoprotein labeled with lysine-specific fluorescent dyes. Together, these results confirm the equilibrium scheme for various apoE structures in solution: oligomer (in aged preparations) <==> 'closed' tetramer <==> 'open' tetramer ('molten globule' state) <==> native or partially denatured monomer <==> fully denatured monomer. Within DMPC:apoE discoidal complex (125:1) the apolipoprotein association state seems to be intermediate between that in solution and in larger vesicular complex (1000:1); for both complexes, the degree of exposure of fluorescein chromophores into water phase decreased. Hetero-associates of apoA-I and apoC-III-1 in solution and in the complexes with DMPC appear to behave similarly to apoE. When extrapolated to native HDL particles, 'molten globule' state seems to be a structure responsible for the interaction of exchangeable apolipoproteins with phospholipid. For a first time, the location of various apolipoprotein molecules on disc periphery was confirmed. The lysine residue(s) seems to locate closely to reacting residue(s) within apolipoprotein molecules in associates, however, with different package constraints for discoidal versus vesicular complexes with phospholipid.
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Affiliation(s)
- Alexander D Dergunov
- National Research Center for Preventive Medicine, 10, Petroverigsky street, 101953 Moscow, Russia.
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Plasencia I, Cruz A, Casals C, Pérez-Gil J. Superficial disposition of the N-terminal region of the surfactant protein SP-C and the absence of specific SP-B-SP-C interactions in phospholipid bilayers. Biochem J 2001; 359:651-9. [PMID: 11672440 PMCID: PMC1222187 DOI: 10.1042/0264-6021:3590651] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
A dansylated form of porcine surfactant-associated protein C (Dns-SP-C), bearing a single dansyl group at its N-terminal end, has been used to characterize the lipid-protein and protein-protein interactions of SP-C reconstituted in phospholipid bilayers, using fluorescence spectroscopy. The fluorescence emission spectrum of Dns-SP-C in phospholipid bilayers is similar to the spectrum of dansyl-phosphatidylethanolamine, and indicates that the N-terminal end of the protein is located at the surface of the membranes and is exposed to the aqueous environment. In membranes containing phosphatidylglycerol (PG), the fluorescence of Dns-SP-C shows a 3-fold increase with respect to the fluorescence of phosphatidylcholine (PC), suggesting that electrostatic lipid-protein interactions induce important effects on the structure and disposition of the N-terminal segment of the protein in these membranes. This effect saturates above 20% PG molar content in the bilayers. The parameters for the interaction of Dns-SP-C with PC or PG have been estimated from the changes induced in the fluorescence emission spectrum of the protein. The protein had similar K(d) values for its interaction with the different phospholipids tested, of the order of a few micromolar. Cooling of Dns-SP-C-containing dipalmitoyl PC bilayers to temperatures below the phase transition of the phospholipid produced a progressive blue-shift of the fluorescence emission of the protein. This effect is interpreted as a consequence of the transfer of the N-terminal segment of the protein into less polar environments that originate during protein lateral segregation. This suggests that conformation and interactions of the N-terminal segment of SP-C could be important in regulating the lateral distribution of the protein in surfactant bilayers and monolayers. Potential SP-B-SP-C interactions have been explored by analysing fluorescence resonance energy transfer (RET) from the single tryptophan in porcine SP-B to dansyl in Dns-SP-C. RET has been detected in samples where native SP-B and Dns-SP-C were concurrently reconstituted in PC or PG bilayers. However, the analysis of the dependence of RET on the protein density excluded specific SP-B-Dns-SP-C associations.
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Affiliation(s)
- I Plasencia
- Departamento de Bioquímica, Facultad de Biología, Universidad Complutense, 28040 Madrid, Spain
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Plasencia I, Cruz A, López-Lacomba JL, Casals C, Pérez-Gil J. Selective labeling of pulmonary surfactant protein SP-C in organic solution. Anal Biochem 2001; 296:49-56. [PMID: 11520031 DOI: 10.1006/abio.2001.5222] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Pulmonary surfactant protein SP-C has been isolated from porcine lungs and treated with dansyl isothiocyanate in chloroform:methanol 2:1 (v/v) solutions,under conditions optimized to introduce a single dansyl group covalently attached to the N-terminalamine group of the protein without loss of its native thioesther-linked palmitic chains. The resulting derivative Dans-SP-C conserves the secondary structure of native SP-C as well as the ability to promote interfacial adsorption of DPPC suspensions and to affect the thermotropic behavior of DPPC bilayers. This derivative can be used to characterize lipid-protein and protein-protein interactions of a native-like SP-C in lipid/protein complexes.
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Affiliation(s)
- I Plasencia
- Departamento de Bioquímica, Facultad de Biología, Madrid, 28040, Spain
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Shearer GC, Stevenson FT, Atkinson DN, Jones H, Staprans I, Kaysen GA. Hypoalbuminemia and proteinuria contribute separately to reduced lipoprotein catabolism in the nephrotic syndrome. Kidney Int 2001; 59:179-89. [PMID: 11135070 DOI: 10.1046/j.1523-1755.2001.00478.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Hypertriglyceridemia is a result of reduced triglyceride (TG)-rich lipoprotein (TRL) catabolism and occurs in rats with nephrotic syndrome (NS) and in Nagase analbuminemic rats (NARs). While the heparin-releasable lipoprotein lipase (LpL) pool in NAR and in NS is similar, TG levels are significantly greater in NS, suggesting that factors other than reduced LpL alone act in NS but not in NARs. Furthermore, clearance of chylomicrons (CM) and very low-density lipoprotein (VLDL) is normal in vivo in NAR despite low LpL levels. We tested the hypotheses that impaired binding of VLDL and impaired VLDL-high density lipoprotein (HDL) interactions contribute to hyperlipidemia in NS. METHODS TG and apoB secretion was measured using Triton WR 1339. Clearance of CMs by perfused hearts from NS and NAR was determined. Binding of VLDL from control, NS and NAR to rat aortic endothelial cells (RAECs) was measured prior to and following incubation with HDL from NS, NARs, and control. ApoE, protein, and TG content was determined. RESULTS TG levels were greatest in NS (516 +/- 95 mg/dL), intermediate in NAR (193 +/- 20), and least in control (97 +/- 16, P = 0.05), while in contrast, TG secretion was least in NS (178 +/- 33 mg/dL/hour) versus 212 +/- 17 in NAR and 294 +/- 15 in control (P < 0.001 vs. NS). Clearance of CMs by NS and NAR hearts was the same and significantly reduced versus control (P < 0.005). Binding of NS-VLDL to endothelial cells was reduced, while NAR-VLDL binding was increased versus control (P < 0.001). Incubation of NS-VLDL with control or NAR HDL increased VLDL binding compared with binding following incubation with NS HDL (P < 0.001). CONCLUSION Increased TG levels in both NS and NAR are the result of decreased TRL clearance. TG levels are greater in NS because of the presence of a combined defect: (1) a decrease in endothelial-bound LpL that occurs as a consequence of reduced serum albumin concentration, and (2) a defect in VLDL binding to endothelial-bound LpL. This latter defect occurs only in the presence of proteinuria and is conferred by HDL.
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Affiliation(s)
- G C Shearer
- Division of Nephrology, Department of Medicine, UC Davis, Davis, CA 95616, USA
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