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Zhang Y, Luo S, Gao Y, Tong W, Sun S. High-Density Lipoprotein Subfractions Remodeling: A Critical Process for the Treatment of Atherosclerotic Cardiovascular Diseases. Angiology 2024; 75:441-453. [PMID: 36788038 DOI: 10.1177/00033197231157473] [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: 02/16/2023]
Abstract
Numerous studies have shown that a low level of high-density lipoprotein cholesterol (HDL-C) is an independent biomarker of cardiovascular disease. High-density lipoprotein (HDL) is considered to be a protective factor for atherosclerosis (AS). Therefore, raising HDL-C has been widely recognized as a promising strategy to treat atherosclerotic cardiovascular diseases (ASCVD). However, several studies have found that increasing HDL-C levels does not necessarily reduce the risk of ASCVD. HDL particles are highly heterogeneous in structure, composition, and biological function. Moreover, HDL particles from atherosclerotic patients exhibit impaired anti-atherogenic functions and these dysfunctional HDL particles might even promote ASCVD. This makes it uncertain that HDL-raising therapy will prevent and treat ASCVD. It is necessary to comprehensively analyze the structure and function of HDL subfractions. We review current advances related to HDL subfractions remodeling and highlight how current lipid-modifying drugs such as niacin, statins, fibrates, and cholesteryl ester transfer protein inhibitors regulate cholesterol concentration of HDL and specific HDL subfractions.
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Affiliation(s)
- Yaling Zhang
- Hunan Provincial Key Laboratory of Tumor Microenvironment Responsive Drug Research, University of South China, Hengyang, China
- School of Pharmaceutical Science, Hengyang Medical School, University of South China, Hengyang, China
| | - Shiyu Luo
- Hunan Provincial Key Laboratory of Tumor Microenvironment Responsive Drug Research, University of South China, Hengyang, China
- School of Pharmaceutical Science, Hengyang Medical School, University of South China, Hengyang, China
| | - Yi Gao
- Hunan Provincial Key Laboratory of Tumor Microenvironment Responsive Drug Research, University of South China, Hengyang, China
- School of Pharmaceutical Science, Hengyang Medical School, University of South China, Hengyang, China
| | - Wenjuan Tong
- Department of Gynecology and Obstetrics, First Affiliated Hospital, University of South China, Hengyang, China
| | - Shaowei Sun
- Hunan Provincial Key Laboratory of Tumor Microenvironment Responsive Drug Research, University of South China, Hengyang, China
- School of Pharmaceutical Science, Hengyang Medical School, University of South China, Hengyang, China
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2
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Ikonen E, Olkkonen VM. Intracellular Cholesterol Trafficking. Cold Spring Harb Perspect Biol 2023; 15:a041404. [PMID: 37277190 PMCID: PMC10411867 DOI: 10.1101/cshperspect.a041404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Cholesterol is an essential lipid species of mammalian cells. Cells acquire it through synthesis in the endoplasmic reticulum (ER) and uptake from lipoprotein particles. Newly synthesized cholesterol is efficiently distributed from the ER to other organelles via lipid-binding/transfer proteins concentrated at membrane contact sites (MCSs) to reach the trans-Golgi network, endosomes, and plasma membrane. Lipoprotein-derived cholesterol is exported from the plasma membrane and endosomal compartments via a combination of vesicle/tubule-mediated membrane transport and transfer through MCSs. In this review, we provide an overview of intracellular cholesterol trafficking pathways, including cholesterol flux from the ER to other membranes, cholesterol uptake from lipoprotein donors and transport from the plasma membrane to the ER, cellular cholesterol efflux to lipoprotein acceptors, as well as lipoprotein cholesterol secretion from enterocytes, hepatocytes, and astrocytes. We also briefly discuss human diseases caused by defects in these processes and therapeutic strategies available in such conditions.
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Affiliation(s)
- Elina Ikonen
- Department of Anatomy and Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, 00100 Helsinki, Finland
- Minerva Foundation Institute for Medical Research, 00290 Helsinki, Finland
| | - Vesa M Olkkonen
- Minerva Foundation Institute for Medical Research, 00290 Helsinki, Finland
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Lebrun LJ, Pallot G, Nguyen M, Tavernier A, Dusuel A, Pilot T, Deckert V, Dugail I, Le Guern N, Pais De Barros JP, Benkhaled A, Choubley H, Lagrost L, Masson D, Gautier T, Grober J. Increased Weight Gain and Insulin Resistance in HF-Fed PLTP Deficient Mice Is Related to Altered Inflammatory Response and Plasma Transport of Gut-Derived LPS. Int J Mol Sci 2022; 23:13226. [PMID: 36362012 PMCID: PMC9654699 DOI: 10.3390/ijms232113226] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 10/24/2022] [Accepted: 10/26/2022] [Indexed: 11/15/2023] Open
Abstract
Bacterial lipopolysaccharides (LPS, endotoxins) are found in high amounts in the gut lumen. LPS can cross the gut barrier and pass into the blood (endotoxemia), leading to low-grade inflammation, a common scheme in metabolic diseases. Phospholipid transfer protein (PLTP) can transfer circulating LPS to plasma lipoproteins, thereby promoting its detoxification. However, the impact of PLTP on the metabolic fate and biological effects of gut-derived LPS is unknown. This study aimed to investigate the influence of PLTP on low-grade inflammation, obesity and insulin resistance in relationship with LPS intestinal translocation and metabolic endotoxemia. Wild-type (WT) mice were compared with Pltp-deficient mice (Pltp-KO) after a 4-month high-fat (HF) diet or oral administration of labeled LPS. On a HF diet, Pltp-KO mice showed increased weight gain, adiposity, insulin resistance, lipid abnormalities and inflammation, together with a higher exposure to endotoxemia compared to WT mice. After oral administration of LPS, PLTP deficiency led to increased intestinal translocation and decreased association of LPS to lipoproteins, together with an altered catabolism of triglyceride-rich lipoproteins (TRL). Our results show that PLTP, by modulating the intestinal translocation of LPS and plasma processing of TRL-bound LPS, has a major impact on low-grade inflammation and the onset of diet-induced metabolic disorders.
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Affiliation(s)
- Lorène J. Lebrun
- INSERM, LNC UMR1231, Université Bourgogne Franche-Comté, 21000 Dijon, France
- FCS Bourgogne-Franche Comté, LipSTIC LabEx, 21000 Dijon, France
- Institut Agro Dijon, 1 Esplanade Erasme, 21000 Dijon, France
| | - Gaëtan Pallot
- INSERM, LNC UMR1231, Université Bourgogne Franche-Comté, 21000 Dijon, France
- FCS Bourgogne-Franche Comté, LipSTIC LabEx, 21000 Dijon, France
| | - Maxime Nguyen
- INSERM, LNC UMR1231, Université Bourgogne Franche-Comté, 21000 Dijon, France
- FCS Bourgogne-Franche Comté, LipSTIC LabEx, 21000 Dijon, France
- Department of Anesthesiology and Intensive Care, Dijon University Hospital, 21000 Dijon, France
| | - Annabelle Tavernier
- INSERM, LNC UMR1231, Université Bourgogne Franche-Comté, 21000 Dijon, France
- FCS Bourgogne-Franche Comté, LipSTIC LabEx, 21000 Dijon, France
- Institut Agro Dijon, 1 Esplanade Erasme, 21000 Dijon, France
| | - Alois Dusuel
- INSERM, LNC UMR1231, Université Bourgogne Franche-Comté, 21000 Dijon, France
- FCS Bourgogne-Franche Comté, LipSTIC LabEx, 21000 Dijon, France
| | - Thomas Pilot
- INSERM, LNC UMR1231, Université Bourgogne Franche-Comté, 21000 Dijon, France
- FCS Bourgogne-Franche Comté, LipSTIC LabEx, 21000 Dijon, France
| | - Valérie Deckert
- INSERM, LNC UMR1231, Université Bourgogne Franche-Comté, 21000 Dijon, France
- FCS Bourgogne-Franche Comté, LipSTIC LabEx, 21000 Dijon, France
| | - Isabelle Dugail
- Faculté de Médecine Pitié-Salpêtrière, UMR1269, 75000 Paris, France
| | - Naig Le Guern
- INSERM, LNC UMR1231, Université Bourgogne Franche-Comté, 21000 Dijon, France
- FCS Bourgogne-Franche Comté, LipSTIC LabEx, 21000 Dijon, France
| | - Jean-Paul Pais De Barros
- INSERM, LNC UMR1231, Université Bourgogne Franche-Comté, 21000 Dijon, France
- FCS Bourgogne-Franche Comté, LipSTIC LabEx, 21000 Dijon, France
- Lipidomic Analytic Plate-Forme, UBFC, Bâtiment B3, 21000 Dijon, France
| | - Anissa Benkhaled
- INSERM, LNC UMR1231, Université Bourgogne Franche-Comté, 21000 Dijon, France
- FCS Bourgogne-Franche Comté, LipSTIC LabEx, 21000 Dijon, France
| | - Hélène Choubley
- INSERM, LNC UMR1231, Université Bourgogne Franche-Comté, 21000 Dijon, France
- FCS Bourgogne-Franche Comté, LipSTIC LabEx, 21000 Dijon, France
- Lipidomic Analytic Plate-Forme, UBFC, Bâtiment B3, 21000 Dijon, France
| | - Laurent Lagrost
- INSERM, LNC UMR1231, Université Bourgogne Franche-Comté, 21000 Dijon, France
- FCS Bourgogne-Franche Comté, LipSTIC LabEx, 21000 Dijon, France
| | - David Masson
- INSERM, LNC UMR1231, Université Bourgogne Franche-Comté, 21000 Dijon, France
- FCS Bourgogne-Franche Comté, LipSTIC LabEx, 21000 Dijon, France
- Laboratory of Clinical Chemistry, François Mitterrand University Hospital, 21000 Dijon, France
| | - Thomas Gautier
- INSERM, LNC UMR1231, Université Bourgogne Franche-Comté, 21000 Dijon, France
- FCS Bourgogne-Franche Comté, LipSTIC LabEx, 21000 Dijon, France
| | - Jacques Grober
- INSERM, LNC UMR1231, Université Bourgogne Franche-Comté, 21000 Dijon, France
- FCS Bourgogne-Franche Comté, LipSTIC LabEx, 21000 Dijon, France
- Institut Agro Dijon, 1 Esplanade Erasme, 21000 Dijon, France
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Wang Y, Li D, Jia Z, Hui J, Xin Q, Zhou Q, Cong W, Xu F. A Bibliometric Analysis of Research on the Links Between Gut Microbiota and Atherosclerosis. Front Cardiovasc Med 2022; 9:941607. [PMID: 35903667 PMCID: PMC9314574 DOI: 10.3389/fcvm.2022.941607] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 06/02/2022] [Indexed: 12/23/2022] Open
Abstract
BackgroundEmerging evidence has linked gut microbiota (GM) and its related metabolites to atherosclerosis (AS). This study aimed to analyze the evolution of GM in AS in the past decades, and provide valuable insights in this field.MethodsWeb of Science Core Collection (WoSCC) was applied to retrieve the publications related to GM in AS from their inception until 2 December 2021, and the data was analyzed in Microsoft Excel, Scimago Graphica, CiteSpace, and VOSviewer.ResultsIn total, 560 documents were extracted from the WoSCC databases. The publications have shown rapid growth since 2008. China and Cleveland Clin were the most prolific country and institution, respectively. The journal with the most publications is Nutrients, and Nature was the most co-cited journal. Among 3556 related authors, Hazen, Stanley L., Tang, W. H. Wilson, and Wang, Zeneng were the top 3 contributing authors in this field. Aside from “gut microbiota,” “atherosclerosis,” the terms “TMAO,” “metabolite,” “obesity,” and “phosphatidylcholine” were frequently occurred in the abstract and title of articles. Burst detection of keywords indicated that “metabolic syndrome,” “acid,” and “bile acid” were hot topics in recent years. According to the co-citation analysis of references, the research focus in this area has changed over time, and recent researches focus on choline, hypertension, butyrate, and berberine.ConclusionOur study showed that the researches of GM in AS have been flourishing, and the content themes were constantly deepened. Human GM is critical to atherosclerotic diseases, and this hot topic is still worthy of more focus in the future.
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Affiliation(s)
- Ya Wang
- Institute of Geriatric, Xiyuan Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Dandan Li
- Institute of Geriatric, Xiyuan Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Zijun Jia
- Institute of Geriatric, Xiyuan Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Jiaqi Hui
- Institute of Geriatric, Xiyuan Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Qiqi Xin
- Laboratory of Cardiovascular Diseases, Xiyuan Hospital, China Academy of Chinese Medical Sciences, Beijing, China
- National Clinical Research Center for Chinese Medicine Cardiology, Beijing, China
| | - Qingbing Zhou
- Institute of Geriatric, Xiyuan Hospital, China Academy of Chinese Medical Sciences, Beijing, China
- *Correspondence: Qingbing Zhou,
| | - Weihong Cong
- Laboratory of Cardiovascular Diseases, Xiyuan Hospital, China Academy of Chinese Medical Sciences, Beijing, China
- National Clinical Research Center for Chinese Medicine Cardiology, Beijing, China
- Weihong Cong,
| | - Fengqin Xu
- Institute of Geriatric, Xiyuan Hospital, China Academy of Chinese Medical Sciences, Beijing, China
- Fengqin Xu,
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Hoekstra M, Liu Q, Zhang Y, van der Wel EJ, Le Dévédec SE, Van Eck M. Hypocholesterolemic phospholipid transfer protein knockout mice exhibit a normal glucocorticoid response to food deprivation. Am J Transl Res 2022; 14:1884-1891. [PMID: 35422905 PMCID: PMC8991128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Accepted: 03/03/2022] [Indexed: 06/14/2023]
Abstract
OBJECTIVES Glucocorticoids, adrenal-derived steroid hormones, facilitate the physiological response to stress. High-density lipoproteins (HDL) are considered the primary source of cholesterol used for glucocorticoid synthesis in mice. Phospholipid transfer protein (PLTP) is a key player in HDL formation. In the current study we tested the hypothesis that HDL deficiency associated with genetic lack of PLTP negatively impacts the adrenal steroid function. METHODS We determined the glucocorticoid response to overnight food deprivation stress and the adrenal lipid and genetic phenotype of wild-type and PLTP knockout mice. RESULTS Basal plasma corticosterone levels, adrenal weights, and adrenocortical neutral lipid stores were not different between wild-type and PLTP knockout mice. Strikingly, plasma corticosterone levels were also equally high in the two groups of mice under fasting conditions (two-way ANOVA genotype effect: P>0.05). However, compensatory mechanisms were active to overcome adrenal lipid depletion, since gene expression levels of cholesterol synthesis, acquisition and mobilization proteins were ~2-fold higher in PLTP knockout adrenals versus wild-type adrenals. In support of an overall similar glucocorticoid stress response, hepatic relative mRNA expression levels of the glucocorticoid receptor target/glucocorticoid-sensitive genes PEPCK, ANGPTL4, FGF21, TDO2 and HMGCS2 were also not different. CONCLUSIONS We have shown that hypocholesterolemic PLTP knockout mice exhibit a normal glucocorticoid response to food deprivation. These novel data (1) highlight that the effect of HDL deficiency on adrenal glucocorticoid output in mice is model dependent and (2) imply that other (lipoprotein) cholesterol sources than HDL can also generate the pool utilized by adrenocortical cells to synthesize glucocorticoids.
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Affiliation(s)
- Menno Hoekstra
- Division of BioTherapeutics, Leiden Academic Centre for Drug Research, Leiden UniversityLeiden, Netherlands
| | - Qiuyu Liu
- Division of Drug Discovery and Safety, Leiden Academic Centre for Drug Research, Leiden UniversityLeiden, Netherlands
| | - Yiheng Zhang
- Division of BioTherapeutics, Leiden Academic Centre for Drug Research, Leiden UniversityLeiden, Netherlands
| | - Ezra J van der Wel
- Division of BioTherapeutics, Leiden Academic Centre for Drug Research, Leiden UniversityLeiden, Netherlands
| | - Sylvia E Le Dévédec
- Division of Drug Discovery and Safety, Leiden Academic Centre for Drug Research, Leiden UniversityLeiden, Netherlands
| | - Miranda Van Eck
- Division of BioTherapeutics, Leiden Academic Centre for Drug Research, Leiden UniversityLeiden, Netherlands
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6
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Sphingolipids and Cholesterol. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1372:1-14. [DOI: 10.1007/978-981-19-0394-6_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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7
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Anaganti N, Rajan S, Hussain MM. An improved assay to measure the phospholipid transfer activity of microsomal triglyceride transport protein. J Lipid Res 2021; 62:100136. [PMID: 34673018 PMCID: PMC8569553 DOI: 10.1016/j.jlr.2021.100136] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 09/27/2021] [Accepted: 10/07/2021] [Indexed: 12/02/2022] Open
Abstract
Microsomal triglyceride transfer protein (MTP) is essential for the assembly and secretion of apolipoprotein B-containing lipoproteins. MTP transfers diverse lipids such as triacylglycerol (TAG) and phospholipids (PLs) between vesicles in vitro. Previously, we described methods to measure these transfer activities using N-7-nitro-2-1,3-benzoxadiazol-4-yl (NBD)-labeled lipids. The NBD-TAG transfer assay is sensitive and can measure MTP activity in cell and tissue homogenates. In contrast, the NBD-PL transfer assay shows high background and is less sensitive; therefore, purified MTP is required to measure its PL transfer activity. Here, we optimized the assay to measure also the PL transfer activity of MTP in cell and tissue homogenates. We found that donor vesicles containing dioleoylphosphoethanolamine and palmitoyloleoylphosphoethanolamine result in a low background signal and are suitable to assay the PL transfer activity of MTP. This assay was capable of measuring protein-dependent and substrate-dependent saturation kinetics. Furthermore, the MTP inhibitor lomitapide blocked this transfer activity. One drawback of the PL transfer assay is that it is less sensitive at physiological temperature than at room temperature, and it requires longer incubation times than the TAG transfer assay. Nevertheless, this significantly improved sensitive assay is simple and easy to perform, involves few steps, can be conducted at room temperature, and is suitable for high-throughput screening to identify inhibitors. This assay can be adapted to measure other PL transfer proteins and to address biological and physiological importance of these activities.
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Affiliation(s)
- Narasimha Anaganti
- Department of Foundations of Medicine, New York University Long Island School of Medicine, Mineola, NY 11501, USA
| | - Sujith Rajan
- Department of Foundations of Medicine, New York University Long Island School of Medicine, Mineola, NY 11501, USA
| | - M Mahmood Hussain
- Department of Foundations of Medicine, New York University Long Island School of Medicine, Mineola, NY 11501, USA; VA New York Harbor Healthcare System, Brooklyn, NY 11209, USA.
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8
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Russo-Savage L, Schulman IG. Liver X receptors and liver physiology. Biochim Biophys Acta Mol Basis Dis 2021; 1867:166121. [PMID: 33713792 DOI: 10.1016/j.bbadis.2021.166121] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 02/26/2021] [Accepted: 03/01/2021] [Indexed: 12/29/2022]
Abstract
The liver x receptors LXRα (NR1H3) and LXRβ (NR1H2) are members of the nuclear hormone receptor superfamily of ligand dependent transcription factors that regulate transcription in response to the direct binding of cholesterol derivatives. Studies using genetic knockouts and synthetic ligands have defined the LXRs as important modulators of lipid homeostasis throughout the body. This review focuses on the control of cholesterol and fatty acid metabolism by LXRs in the liver and how modifying LXR activity can influence the pathology of liver diseases.
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Affiliation(s)
- Lillian Russo-Savage
- Department of Pharmacology, University of Virginia, School of Medicine, United States of America
| | - Ira G Schulman
- Department of Pharmacology, University of Virginia, School of Medicine, United States of America.
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9
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Berger JM, Moon YA. Increased Hepatic Lipogenesis Elevates Liver Cholesterol Content. Mol Cells 2021; 44:116-125. [PMID: 33658436 PMCID: PMC7941001 DOI: 10.14348/molcells.2021.2147] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 12/17/2020] [Accepted: 02/07/2021] [Indexed: 01/01/2023] Open
Abstract
Cardiovascular diseases (CVDs) are the most common cause of death in patients with nonalcoholic fatty liver disease (NAFLD) and dyslipidemia is considered at least partially responsible for the increased CVD risk in NAFLD patients. The aim of the present study is to understand how hepatic de novo lipogenesis influences hepatic cholesterol content as well as its effects on the plasma lipid levels. Hepatic lipogenesis was induced in mice by feeding a fat-free/high-sucrose (FF/HS) diet and the metabolic pathways associated with cholesterol were then analyzed. Both liver triglyceride and cholesterol contents were significantly increased in mice fed an FF/HS diet. Activation of fatty acid synthesis driven by the activation of sterol regulatory element binding protein (SREBP)-1c resulted in the increased liver triglycerides. The augmented cholesterol content in the liver could not be explained by an increased cholesterol synthesis, which was decreased by the FF/HS diet. HMGCoA reductase protein level was decreased in mice fed an FF/HS diet. We found that the liver retained more cholesterol through a reduced excretion of bile acids, a reduced fecal cholesterol excretion, and an increased cholesterol uptake from plasma lipoproteins. Very low-density lipoproteintriglyceride and -cholesterol secretion were increased in mice fed an FF/HS diet, which led to hypertriglyceridemia and hypercholesterolemia in Ldlr-/- mice, a model that exhibits a more human like lipoprotein profile. These findings suggest that dietary cholesterol intake and cholesterol synthesis rates cannot only explain the hypercholesterolemia associated with NAFLD, and that the control of fatty acid synthesis should be considered for the management of dyslipidemia.
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Affiliation(s)
- Jean-Mathieu Berger
- Departments of Internal Medicine and Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Young-Ah Moon
- Department of Molecular Medicine, Inha University College of Medicine, Incheon 22212, Korea
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10
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Jiang XC, Yu Y. The Role of Phospholipid Transfer Protein in the Development of Atherosclerosis. Curr Atheroscler Rep 2021; 23:9. [PMID: 33496859 DOI: 10.1007/s11883-021-00907-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/13/2021] [Indexed: 12/11/2022]
Abstract
PURPOSE OF REVIEW Phospholipid transfer protein (PLTP), a member of lipid transfer protein family, is an important protein involved in lipid metabolism in the circulation. This article reviews recent PLTP research progresses, involving lipoprotein metabolism and atherogenesis. RECENT FINDINGS PLTP activity influences atherogenic and anti-atherogenic lipoprotein levels. Human serum PLTP activity is a risk factor for human cardiovascular disease and is an independent predictor of all-cause mortality. PLTP deficiency reduces VLDL and LDL levels and attenuates atherosclerosis in mouse models, while PLTP overexpression exerts an opposite effect. Both PLTP deficiency and overexpression result in reduction of HDL which has different size, inflammatory index, and lipid composition. Moreover, although both PLTP deficiency and overexpression reduce cholesterol efflux capacity, but this effect has no impact in macrophage reverse cholesterol transport in mice. Furthermore, PLTP activity is related with metabolic syndrome, thrombosis, and inflammation. PLTP could be target for the treatment of dyslipidemia and atherosclerosis, although some potential off-target effects should be noted.
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Affiliation(s)
- Xian-Cheng Jiang
- Department of Cell Biology, SUNY Downstate Health Sciences University, 450 Clarkson Ave, Brooklyn, NY, USA.
| | - Yang Yu
- Shandong First Medical University & Shandong Academy of Medical Sciences, Taian, 271000, People's Republic of China
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11
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Impact of Phospholipid Transfer Protein in Lipid Metabolism and Cardiovascular Diseases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1276:1-13. [PMID: 32705590 DOI: 10.1007/978-981-15-6082-8_1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
PLTP plays an important role in lipoprotein metabolism and cardiovascular disease development in humans; however, the mechanisms are still not completely understood. In mouse models, PLTP deficiency reduces cardiovascular disease, while its overexpression induces it. Therefore, we used mouse models to investigate the involved mechanisms. In this chapter, the recent main progresses in the field of PLTP research are summarized, and our focus is on the relationship between PLTP and lipoprotein metabolism, as well as PLTP and cardiovascular diseases.
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12
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van Dijk PR, Abdulle AE, Bulthuis ML, Perton FG, Connelly MA, van Goor H, Dullaart RP. The Systemic Redox Status Is Maintained in Non-Smoking Type 2 Diabetic Subjects Without Cardiovascular Disease: Association with Elevated Triglycerides and Large VLDL. J Clin Med 2019; 9:jcm9010049. [PMID: 31878321 PMCID: PMC7019670 DOI: 10.3390/jcm9010049] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 12/10/2019] [Accepted: 12/22/2019] [Indexed: 12/11/2022] Open
Abstract
Decreased circulating levels of free thiols (R-SH, sulfhydryl groups) reflect enhanced oxidative stress, which plays an important role in the pathogenesis of cardiometabolic diseases. Since hyperglycemia causes oxidative stress, we questioned whether plasma free thiols are altered in patients with type 2 diabetes mellitus (T2DM) without cardiovascular disease or renal function impairment. We also determined their relationship with elevated triglycerides and very low density lipoproteins (VLDL), a central feature of diabetic dyslipidemia. Fasting plasma free thiols (colorimetric method), lipoproteins, VLDL (nuclear magnetic resonance spectrometry), free fatty acids (FFA), phospholipid transfer protein (PLTP) activity and adiponectin were measured in 79 adult non-smoking T2DM subjects (HbA1c 51 ± 8 mmol/mol, no use of insulin or lipid lowering drugs), and in 89 non-smoking subjects without T2DM. Plasma free thiols were univariately correlated with glucose (r = 0.196, p < 0.05), but were not decreased in T2DM subjects versus non-diabetic subjects (p = 0.31). Free thiols were higher in subjects with (663 ± 84 µmol/L) versus subjects without elevated triglycerides (619 ± 91 µmol/L; p = 0.002). Age- and sex-adjusted multivariable linear regression analysis demonstrated that plasma triglycerides were positively and independently associated with free thiols (β = 0.215, p = 0.004), FFA (β = 0.168, p = 0.029) and PLTP activity (β = 0.228, p = 0.002), inversely with adiponectin (β = −0.308, p < 0.001) but not with glucose (β = 0.052, p = 0.51). Notably, the positive association of free thiols with (elevated) triglycerides appeared to be particularly evident in men. Additionally, large VLDL were independently associated with free thiols (β = 0.188, p = 0.029). In conclusion, circulating free thiols are not decreased in this cohort of non-smoking and generally well-controlled T2DM subjects. Paradoxically, higher triglycerides and more large VLDL particles are likely associated with higher plasma levels of thiols, reflecting lower systemic oxidative stress.
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Affiliation(s)
- Peter R. van Dijk
- Department of Endocrinology, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, The Netherlands;
- Correspondence:
| | - Amaal Eman Abdulle
- Department of Internal Medicine, division vascular medicine, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, The Netherlands
| | - Marian L.C. Bulthuis
- Department of Pathology and Medical, Biology, Section Pathology, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, The Netherlands (H.v.G.)
| | - Frank G. Perton
- Laboratory Center, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, The Netherlands;
| | - Margery A. Connelly
- Laboratory Corporation of America® Holdings (LabCorp), Morrisville, NC 27560, USA;
| | - Harry van Goor
- Department of Pathology and Medical, Biology, Section Pathology, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, The Netherlands (H.v.G.)
| | - Robin P.F. Dullaart
- Department of Endocrinology, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, The Netherlands;
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13
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Song G, Zong C, Shao M, Yu Y, Liu Q, Wang H, Qiu T, Jiao P, Guo Z, Lee P, Luo Y, Jiang XC, Qin S. Phospholipid transfer protein (PLTP) deficiency attenuates high fat diet induced obesity and insulin resistance. Biochim Biophys Acta Mol Cell Biol Lipids 2019; 1864:1305-1313. [PMID: 31220615 DOI: 10.1016/j.bbalip.2019.06.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 06/07/2019] [Accepted: 06/14/2019] [Indexed: 01/09/2023]
Abstract
Increased phospholipid transfer protein (PLTP) activity has been found to be associated with obesity, and metabolic syndrome in humans. However, whether or not PLTP has a direct effect on insulin sensitivity and obesity is largely unknown. Here we analyzed the effect by using PLTP knockout (PLTP-/-) mouse model. Although, PLTP-/- mice have normal body-weight-gain under chow diet, these mice were protected from high-fat-diet-induced obesity and insulin resistance, compared with wild type mice. In order to understand the mechanism, we evaluated insulin receptor and Akt activation and found that PLTP deficiency significantly enhanced phosphorylated insulin receptor and Akt levels in high-fat-diet fed mouse livers, adipose tissues, and muscles after insulin stimulation, while total Akt and insulin receptor levels were unchanged. Moreover, we found that the PLTP deficiency induced significantly more GLUT4 protein in the plasma membranes of adipocytes and muscle cells after insulin stimulation. Finally, we found that PLTP-deficient hepatocytes had less sphingomyelins and free cholesterols in the lipid rafts and plasma membranes than that of controls and this may provide a molecular basis for PLTP deficiency-mediated increase in insulin sensitivity. We have concluded that PLTP deficiency leads to an improvement in tissue and whole-body insulin sensitivity through modulating lipid levels in the plasma membrane, especially in the lipid rafts.
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Affiliation(s)
- Guohua Song
- Key Laboratory of Atherosclerosis in Universities of Shandong and Institute of Atherosclerosis, Shandong First Medical University & Shandong Academy of Medical Sciences, Shandong, China.
| | - Chuanlong Zong
- Key Laboratory of Atherosclerosis in Universities of Shandong and Institute of Atherosclerosis, Shandong First Medical University & Shandong Academy of Medical Sciences, Shandong, China
| | - Mingzhu Shao
- Key Laboratory of Atherosclerosis in Universities of Shandong and Institute of Atherosclerosis, Shandong First Medical University & Shandong Academy of Medical Sciences, Shandong, China
| | - Yang Yu
- Key Laboratory of Atherosclerosis in Universities of Shandong and Institute of Atherosclerosis, Shandong First Medical University & Shandong Academy of Medical Sciences, Shandong, China
| | - Qian Liu
- Key Laboratory of Atherosclerosis in Universities of Shandong and Institute of Atherosclerosis, Shandong First Medical University & Shandong Academy of Medical Sciences, Shandong, China
| | - Hui Wang
- Key Laboratory of Atherosclerosis in Universities of Shandong and Institute of Atherosclerosis, Shandong First Medical University & Shandong Academy of Medical Sciences, Shandong, China
| | - Tingting Qiu
- Key Laboratory of Atherosclerosis in Universities of Shandong and Institute of Atherosclerosis, Shandong First Medical University & Shandong Academy of Medical Sciences, Shandong, China
| | - Peng Jiao
- Key Laboratory of Atherosclerosis in Universities of Shandong and Institute of Atherosclerosis, Shandong First Medical University & Shandong Academy of Medical Sciences, Shandong, China
| | - Zheng Guo
- Key Laboratory of Atherosclerosis in Universities of Shandong and Institute of Atherosclerosis, Shandong First Medical University & Shandong Academy of Medical Sciences, Shandong, China
| | - Phoebe Lee
- Downstate Medical Center State University of New York, NY, USA
| | - Yi Luo
- Downstate Medical Center State University of New York, NY, USA
| | | | - Shucun Qin
- Key Laboratory of Atherosclerosis in Universities of Shandong and Institute of Atherosclerosis, Shandong First Medical University & Shandong Academy of Medical Sciences, Shandong, China.
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14
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Zhao XM, Wang Y, Yu Y, Jiang H, Babinska A, Chen XY, He KG, Min XD, Han JJ, Yang CX, Deng K, Xue J, Zhang X, Song GH, Qin SC, Jiang XC. Plasma Phospholipid Transfer Protein Promotes Platelet Aggregation. Thromb Haemost 2018; 118:2086-2097. [PMID: 30419596 DOI: 10.1055/s-0038-1675228] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
It remains unclear whether plasma phospholipid transfer protein (PLTP) is involved in hyper-coagulation or hypo-coagulation. This study investigated the direct effect of PLTP on platelet aggregation and the underlying mechanism. Washed platelets from humans or mice and mouse platelet-rich plasma and human recombinant PLTP were isolated. PLTP is present in human platelets. We assessed adenosine diphosphate (ADP)-, collagen- and thrombin-induced platelet aggregation, phosphatidylserine externalization and photothrombosis-induced cerebral infarction in mice. PLTP over-expression increased platelet aggregation, while PLTP deficiency had the opposing reaction. Human recombinant PLTP increased both mouse and human platelet aggregation in a dose-dependent manner. Phosphatidylserine externalization provides a water/lipid surface for the interaction of coagulation factors, which accelerates thrombosis. Compared with wild-type controls, platelets from PLTP transgenic mice had significantly more phosphatidylserine on the exterior surface of the plasma membrane, whereas platelets from PLTP-deficient mice had significantly less phosphatidylserine on the surface, thus PLTP influences fibrinogen binding on the plasma membrane. Moreover, recombinant PLTP together with ADP significantly increased phosphatidylserine exposure on the plasma membrane of PLTP-deficient platelets, thereby increasing fibrinogen binding. PLTP over-expression significantly accelerated the incidence of photothrombosis-induced infarction in mice, whereas PLTP deficiency significantly reduced the frequency of infarction. We concluded that PLTP promotes phosphatidylserine externalization at the plasma membrane of platelets and accelerates ADP- or collagen-induced platelet aggregation. This effect plays an important role in the initiation of thrombin generation and platelet aggregation under sheer stress conditions. Thus, PLTP is involved in hyper-coagulation. Therefore, PLTP inhibition could be a novel approach for countering thrombosis.
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Affiliation(s)
- Xiao-Min Zhao
- The Institute of Atherosclerosis, Taishan Medical University, Taian, China
| | - Yun Wang
- The Institute of Atherosclerosis, Taishan Medical University, Taian, China
| | - Yang Yu
- The Institute of Atherosclerosis, Taishan Medical University, Taian, China
| | - Hui Jiang
- Department of Cell Biology, SUNY Downstate Medical Center, Brooklyn, New York, United States
| | - Anna Babinska
- Department of Cell Biology, SUNY Downstate Medical Center, Brooklyn, New York, United States
| | - Xiu-Yu Chen
- The Institute of Atherosclerosis, Taishan Medical University, Taian, China
| | - Ke-Gui He
- The Institute of Atherosclerosis, Taishan Medical University, Taian, China
| | - Xiang-Dong Min
- The Institute of Atherosclerosis, Taishan Medical University, Taian, China
| | - Ji-Ju Han
- The Institute of Atherosclerosis, Taishan Medical University, Taian, China
| | - Chen-Xi Yang
- The Institute of Atherosclerosis, Taishan Medical University, Taian, China
| | - Kevin Deng
- Department of Cell Biology, SUNY Downstate Medical Center, Brooklyn, New York, United States
| | - Jing Xue
- Hebei Collaborative Innovation Center for Cardio-cerebrovascular Disease, Hebei Key Laboratory of Vascular Homeostasis, Shijiazhuang, China
| | - Xiangjian Zhang
- Hebei Collaborative Innovation Center for Cardio-cerebrovascular Disease, Hebei Key Laboratory of Vascular Homeostasis, Shijiazhuang, China
| | - Guo-Hua Song
- The Institute of Atherosclerosis, Taishan Medical University, Taian, China
| | - Shu-Cun Qin
- The Institute of Atherosclerosis, Taishan Medical University, Taian, China
| | - Xian-Cheng Jiang
- Department of Cell Biology, SUNY Downstate Medical Center, Brooklyn, New York, United States.,Molecular and Cellular Cardiology Program, VA New York Harbor Healthcare System, Brooklyn, New York, United States
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15
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Bhatt-Wessel B, Jordan TW, Miller JH, Peng L. Role of DGAT enzymes in triacylglycerol metabolism. Arch Biochem Biophys 2018; 655:1-11. [PMID: 30077544 DOI: 10.1016/j.abb.2018.08.001] [Citation(s) in RCA: 107] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 07/25/2018] [Accepted: 08/02/2018] [Indexed: 01/22/2023]
Abstract
The esterification of a fatty acyl moiety to diacylglycerol to form triacylglycerol (TAG) is catalysed by two diacylglycerol O-acyltransferases (DGATs) encoded by genes belonging to two distinct gene families. The enzymes are referred to as DGAT1 and DGAT2 in order of their identification. Both proteins are transmembrane proteins localized in the endoplasmic reticulum. Their membrane topologies are however significantly different. This difference is hypothesized to give the two isozymes different abilities to interact with other proteins and organelles and access to different pools of fatty acids, thereby creating a distinction between the enzymes in terms of their role and contribution to lipid metabolism. DGAT1 is proposed to have dual topology contributing to TAG synthesis on both sides of the ER membrane and esterifying only the pre-formed fatty acids. There is evidence to suggest that DGAT2 translocates to the lipid droplet (LD), associates with other proteins, and synthesizes cytosolic and luminal apolipoprotein B associated LD-TAG from both endogenous and exogenous fatty acids. The aim of this review is to differentiate between the two DGAT enzymes by comparing the genes that encode them, their proposed topologies, the proteins they interact with, and their roles in lipid metabolism.
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Affiliation(s)
- Bhumika Bhatt-Wessel
- Centre for Biodiscovery and School of Biological Sciences, Victoria University of Wellington, New Zealand
| | - T William Jordan
- Centre for Biodiscovery and School of Biological Sciences, Victoria University of Wellington, New Zealand
| | - John H Miller
- Centre for Biodiscovery and School of Biological Sciences, Victoria University of Wellington, New Zealand
| | - Lifeng Peng
- Centre for Biodiscovery and School of Biological Sciences, Victoria University of Wellington, New Zealand.
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16
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Yu Y, Lei X, Jiang H, Li Z, Creemers JWM, Zhang M, Qin S, Jin W, Jiang X. Prodomain of Furin Promotes Phospholipid Transfer Protein Proteasomal Degradation in Hepatocytes. J Am Heart Assoc 2018; 7:e008526. [PMID: 29680823 PMCID: PMC6015287 DOI: 10.1161/jaha.118.008526] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Accepted: 03/22/2018] [Indexed: 12/21/2022]
Abstract
BACKGROUND Phospholipid transfer protein (PLTP) is one of the major modulators of lipoprotein metabolism and atherosclerosis development; however, little is known about the regulation of PLTP. The effect of hepatic prodomain of furin (profurin) expression on PLTP processing and function is investigated. METHODS AND RESULTS We used adenovirus expressing profurin in mouse liver to evaluate PLTP activity, mass, and plasma lipid levels. We coexpressed PLTP and profurin in human hepatoma cell line cells and studied their interaction. We found profurin expression significantly reduced plasma lipids, plasma PLTP activity, and mass in all tested mouse models, compared with controls. Moreover, the expression of profurin dramatically reduced liver PLTP activity and protein level. We further explored the mechanism using in vivo and ex vivo approaches. We found that profurin can interact with intracellular PLTP and promote its ubiquitination and proteasomal degradation, resulting in less PLTP secretion from the hepatocytes. Furin does not cleave PLTP; instead, it forms a complex with PLTP, likely through its prodomain. CONCLUSIONS Our study reveals that hepatic PLTP protein is targeted for proteasomal degradation by profurin expression, which could be a novel posttranslational mechanism underlying PLTP regulation.
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Affiliation(s)
- Yang Yu
- Department of Cell BiologyState University of New York Downstate Medical CenterBrooklynNY
- Key Laboratory of Atherosclerosis in Universities of Shandong and Institute of AtherosclerosisTaishan Medical UniversityTaianChina
| | - Xia Lei
- Department of Cell BiologyState University of New York Downstate Medical CenterBrooklynNY
| | - Hui Jiang
- Department of Cell BiologyState University of New York Downstate Medical CenterBrooklynNY
| | - Zhiqiang Li
- Department of Cell BiologyState University of New York Downstate Medical CenterBrooklynNY
| | - John W. M. Creemers
- Laboratory of Biochemical NeuroendocrinologyDepartment of Human GeneticsHerestraat 49 bus 6023000 LeuvenBelgium
| | - Ming Zhang
- Department of Cell BiologyState University of New York Downstate Medical CenterBrooklynNY
| | - Shucun Qin
- Key Laboratory of Atherosclerosis in Universities of Shandong and Institute of AtherosclerosisTaishan Medical UniversityTaianChina
| | - Weijun Jin
- Department of Cell BiologyState University of New York Downstate Medical CenterBrooklynNY
| | - Xian‐Cheng Jiang
- Department of Cell BiologyState University of New York Downstate Medical CenterBrooklynNY
- Molecular and Cellular Cardiology ProgramVeterans Affair New York Harbor Healthcare SystemBrooklynNY
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17
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Sirwi A, Hussain MM. Lipid transfer proteins in the assembly of apoB-containing lipoproteins. J Lipid Res 2018; 59:1094-1102. [PMID: 29650752 DOI: 10.1194/jlr.r083451] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Revised: 04/12/2018] [Indexed: 11/20/2022] Open
Abstract
A better understanding of intracellular lipoprotein assembly may help identify proteins with important roles in lipid disorders. apoB-containing lipoproteins (B-lps) are macromolecular lipid and protein micelles that act as specialized transport vehicles for hydrophobic lipids. They are assembled predominantly in enterocytes and hepatocytes to transport dietary and endogenous fat, respectively, to different tissues. Assembly occurs in the endoplasmic reticulum (ER) and is dependent on lipid resynthesis in the ER and on a chaperone, namely, microsomal triglyceride transfer protein (MTTP). Precursors for lipid synthesis are obtained from extracellular sources and from cytoplasmic lipid droplets. MTTP is the major and essential lipid transfer protein that transfers phospholipids and triacylglycerols to nascent apoB for the assembly of lipoproteins. Assembly is aided by cell death-inducing DFF45-like effector B and by phospholipid transfer protein, which may facilitate additional deposition of triacylglycerols and phospholipids, respectively, to apoB. Here, we summarize the current understanding of the different steps in the assembly of B-lps and discuss the role of lipid transfer proteins in these steps to help identify new clinical targets for lipid-associated disorders, such as heart disease.
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Affiliation(s)
- Alaa Sirwi
- School of Graduate Studies, Molecular and Cell Biology Program, State University of New York Downstate Medical Center, Brooklyn, NY
| | - M Mahmood Hussain
- New York University Winthrop Hospital, Mineola, NY and Veterans Affairs New York Harbor Healthcare System, Brooklyn, NY
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18
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Jiang XC. Phospholipid transfer protein: its impact on lipoprotein homeostasis and atherosclerosis. J Lipid Res 2018; 59:764-771. [PMID: 29438986 DOI: 10.1194/jlr.r082503] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Revised: 01/10/2018] [Indexed: 12/25/2022] Open
Abstract
Phospholipid transfer protein (PLTP) is one of the major modulators of lipoprotein metabolism and atherosclerosis development in humans; however, we still do not quite understand the mechanisms. In mouse models, PLTP overexpression induces atherosclerosis, while its deficiency reduces it. Thus, mouse models were used to explore the mechanisms. In this review, I summarize the major progress made in the PLTP research field and emphasize its impact on lipoprotein metabolism and atherosclerosis, as well as its regulation.
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Affiliation(s)
- Xian-Cheng Jiang
- Department of Cell Biology, Downstate Medical Center, State University of New York, Brooklyn, NY
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19
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Common, low-frequency, and rare genetic variants associated with lipoprotein subclasses and triglyceride measures in Finnish men from the METSIM study. PLoS Genet 2017; 13:e1007079. [PMID: 29084231 PMCID: PMC5679656 DOI: 10.1371/journal.pgen.1007079] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Revised: 11/09/2017] [Accepted: 10/16/2017] [Indexed: 12/12/2022] Open
Abstract
Lipid and lipoprotein subclasses are associated with metabolic and cardiovascular diseases, yet the genetic contributions to variability in subclass traits are not fully understood. We conducted single-variant and gene-based association tests between 15.1M variants from genome-wide and exome array and imputed genotypes and 72 lipid and lipoprotein traits in 8,372 Finns. After accounting for 885 variants at 157 previously identified lipid loci, we identified five novel signals near established loci at HIF3A, ADAMTS3, PLTP, LCAT, and LIPG. Four of the signals were identified with a low-frequency (0.005<minor allele frequency [MAF]<0.05) or rare (MAF<0.005) variant, including Arg123His in LCAT. Gene-based associations (P<10-10) support a role for coding variants in LIPC and LIPG with lipoprotein subclass traits. 30 established lipid-associated loci had a stronger association for a subclass trait than any conventional trait. These novel association signals provide further insight into the molecular basis of dyslipidemia and the etiology of metabolic disorders.
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20
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Paalvast Y, Gerding A, Wang Y, Bloks VW, van Dijk TH, Havinga R, Willems van Dijk K, Rensen PCN, Bakker BM, Kuivenhoven JA, Groen AK. Male apoE*3-Leiden.CETP mice on high-fat high-cholesterol diet exhibit a biphasic dyslipidemic response, mimicking the changes in plasma lipids observed through life in men. Physiol Rep 2017; 5:e13376. [PMID: 29038350 PMCID: PMC5641925 DOI: 10.14814/phy2.13376] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 07/08/2017] [Accepted: 07/10/2017] [Indexed: 12/18/2022] Open
Abstract
Physiological adaptations resulting in the development of the metabolic syndrome in man occur over a time span of several decades. This combined with the prohibitive financial cost and ethical concerns to measure key metabolic parameters repeatedly in subjects for the major part of their life span makes that comprehensive longitudinal human data sets are virtually nonexistent. While experimental mice are often used, little is known whether this species is in fact an adequate model to better understand the mechanisms that drive the metabolic syndrome in man. We took up the challenge to study the response of male apoE*3-Leiden.CETP mice (with a humanized lipid profile) to a high-fat high-cholesterol diet for 6 months. Study parameters include body weight, food intake, plasma and liver lipids, hepatic transcriptome, VLDL - triglyceride production and importantly the use of stable isotopes to measure hepatic de novo lipogenesis, gluconeogenesis, and biliary/fecal sterol secretion to assess metabolic fluxes. The key observations include (1) high inter-individual variation; (2) a largely unaffected hepatic transcriptome at 2, 3, and 6 months; (3) a biphasic response curve of the main metabolic features over time; and (4) maximum insulin resistance preceding dyslipidemia. The biphasic response in plasma triglyceride and total cholesterol appears to mimic that of men in cross-sectional studies. Combined, these observations suggest that studies such as these can help to delineate the causes of metabolic derangements in patients suffering from metabolic syndrome.
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Affiliation(s)
- Yared Paalvast
- Department of Pediatrics, University Medical Center Groningen, Groningen, The Netherlands
| | - Albert Gerding
- Department of Pediatrics, University Medical Center Groningen, Groningen, The Netherlands
| | - Yanan Wang
- Department of Pediatrics, University Medical Center Groningen, Groningen, The Netherlands
- Department Medicine, Division Endocrinology, Leiden University Medical Center, Leiden, The Netherlands
| | - Vincent W Bloks
- Department of Pediatrics, University Medical Center Groningen, Groningen, The Netherlands
| | - Theo H van Dijk
- Department of Pediatrics, University Medical Center Groningen, Groningen, The Netherlands
| | - Rick Havinga
- Department of Pediatrics, University Medical Center Groningen, Groningen, The Netherlands
| | - Ko Willems van Dijk
- Department Medicine, Division Endocrinology, Leiden University Medical Center, Leiden, The Netherlands
- Einthoven Laboratory for Experimental Vascular Medicine Leiden University Medical Center, Leiden, The Netherlands
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Patrick C N Rensen
- Department Medicine, Division Endocrinology, Leiden University Medical Center, Leiden, The Netherlands
- Einthoven Laboratory for Experimental Vascular Medicine Leiden University Medical Center, Leiden, The Netherlands
| | - Barbara M Bakker
- Department of Pediatrics, University Medical Center Groningen, Groningen, The Netherlands
| | - Jan Albert Kuivenhoven
- Department of Pediatrics, University Medical Center Groningen, Groningen, The Netherlands
| | - Albert K Groen
- Department of Laboratory Medicine, University Medical Center Groningen, Groningen, The Netherlands
- Department of Vascular Medicine, Amsterdam Medical Center, Amsterdam, The Netherlands
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21
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Warren CR, O'Sullivan JF, Friesen M, Becker CE, Zhang X, Liu P, Wakabayashi Y, Morningstar JE, Shi X, Choi J, Xia F, Peters DT, Florido MHC, Tsankov AM, Duberow E, Comisar L, Shay J, Jiang X, Meissner A, Musunuru K, Kathiresan S, Daheron L, Zhu J, Gerszten RE, Deo RC, Vasan RS, O'Donnell CJ, Cowan CA. Induced Pluripotent Stem Cell Differentiation Enables Functional Validation of GWAS Variants in Metabolic Disease. Cell Stem Cell 2017; 20:547-557.e7. [PMID: 28388431 DOI: 10.1016/j.stem.2017.01.010] [Citation(s) in RCA: 110] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Revised: 10/10/2016] [Accepted: 01/27/2017] [Indexed: 12/14/2022]
Abstract
Genome-wide association studies (GWAS) have highlighted a large number of genetic variants with potential disease association, but functional analysis remains a challenge. Here we describe an approach to functionally validate identified variants through differentiation of induced pluripotent stem cells (iPSCs) to study cellular pathophysiology. We collected peripheral blood cells from Framingham Heart Study participants and reprogrammed them to iPSCs. We then differentiated 68 iPSC lines into hepatocytes and adipocytes to investigate the effect of the 1p13 rs12740374 variant on cardiometabolic disease phenotypes via transcriptomics and metabolomic signatures. We observed a clear association between rs12740374 and lipid accumulation and gene expression in differentiated hepatocytes, in particular, expression of SORT1, CELSR2, and PSRC1, consistent with previous analyses of this variant using other approaches. Initial investigation of additional SNPs also highlighted correlations with gene expression. These findings suggest that iPSC-based population studies hold promise as tools for the functional validation of GWAS variants.
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Affiliation(s)
- Curtis R Warren
- Department of Stem Cell and Regenerative Biology and Harvard Stem Cell Institute, Harvard University, Cambridge, MA 02138, USA
| | - John F O'Sullivan
- Cardiovascular Research Center and Cardiology Division, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
| | - Max Friesen
- Department of Stem Cell and Regenerative Biology and Harvard Stem Cell Institute, Harvard University, Cambridge, MA 02138, USA
| | - Caroline E Becker
- Department of Stem Cell and Regenerative Biology and Harvard Stem Cell Institute, Harvard University, Cambridge, MA 02138, USA
| | - Xiaoling Zhang
- School of Medicine, Boston University, Boston, MA 02118, USA; The Framingham Heart Study, Population Sciences Branch, Division of Intramural Research, National Heart, Lung and Blood Institute, Framingham, MA 01702, USA
| | - Poching Liu
- DNA Sequencing and Genomics Core, National Heart Lung and Blood Institute, NIH, Bethesda, MD 20892, USA
| | - Yoshiyuki Wakabayashi
- DNA Sequencing and Genomics Core, National Heart Lung and Blood Institute, NIH, Bethesda, MD 20892, USA
| | - Jordan E Morningstar
- Cardiovascular Research Center and Cardiology Division, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
| | - Xu Shi
- Cardiovascular Research Center and Cardiology Division, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
| | - Jihoon Choi
- Department of Stem Cell and Regenerative Biology and Harvard Stem Cell Institute, Harvard University, Cambridge, MA 02138, USA
| | - Fang Xia
- Department of Stem Cell and Regenerative Biology and Harvard Stem Cell Institute, Harvard University, Cambridge, MA 02138, USA
| | - Derek T Peters
- Department of Stem Cell and Regenerative Biology and Harvard Stem Cell Institute, Harvard University, Cambridge, MA 02138, USA
| | - Mary H C Florido
- Department of Stem Cell and Regenerative Biology and Harvard Stem Cell Institute, Harvard University, Cambridge, MA 02138, USA
| | - Alexander M Tsankov
- Department of Stem Cell and Regenerative Biology and Harvard Stem Cell Institute, Harvard University, Cambridge, MA 02138, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Eilene Duberow
- Department of Stem Cell and Regenerative Biology and Harvard Stem Cell Institute, Harvard University, Cambridge, MA 02138, USA
| | - Lauren Comisar
- Department of Stem Cell and Regenerative Biology and Harvard Stem Cell Institute, Harvard University, Cambridge, MA 02138, USA
| | - Jennifer Shay
- Department of Stem Cell and Regenerative Biology and Harvard Stem Cell Institute, Harvard University, Cambridge, MA 02138, USA
| | - Xin Jiang
- Department of Stem Cell and Regenerative Biology and Harvard Stem Cell Institute, Harvard University, Cambridge, MA 02138, USA
| | - Alexander Meissner
- Department of Stem Cell and Regenerative Biology and Harvard Stem Cell Institute, Harvard University, Cambridge, MA 02138, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Kiran Musunuru
- Department of Stem Cell and Regenerative Biology and Harvard Stem Cell Institute, Harvard University, Cambridge, MA 02138, USA
| | - Sekar Kathiresan
- Center for Human Genetic Research and Cardiovascular Research Center, Massachusetts General Hospital, 185 Cambridge Street, CPZN 5.252, Boston, MA 02114, USA
| | - Laurence Daheron
- Department of Stem Cell and Regenerative Biology and Harvard Stem Cell Institute, Harvard University, Cambridge, MA 02138, USA
| | - Jun Zhu
- DNA Sequencing and Genomics Core, National Heart Lung and Blood Institute, NIH, Bethesda, MD 20892, USA
| | - Robert E Gerszten
- Cardiovascular Research Center and Cardiology Division, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
| | - Rahul C Deo
- Cardiovascular Research Institute, Department of Medicine and Institute for Human Genetics, University of California, San Francisco, and California Institute for Quantitative Biosciences, San Francisco, CA 94143, USA
| | - Ramachandran S Vasan
- The Framingham Heart Study, Sections of Preventive Medicine and Epidemiology and Cardiology, Framingham, MA 01702, USA; School of Medicine, Boston University, Boston, MA 02118, USA; School of Public Health, Boston University, Boston, MA 02118, USA
| | - Christopher J O'Donnell
- The Framingham Heart Study, Population Sciences Branch, Division of Intramural Research, National Heart, Lung and Blood Institute, Framingham, MA 01702, USA; Cardiology Section, Department of Medicine, Boston Veterans Administration Healthcare and Brigham and Women's Hospital, Boston, MA 02114, USA
| | - Chad A Cowan
- Department of Stem Cell and Regenerative Biology and Harvard Stem Cell Institute, Harvard University, Cambridge, MA 02138, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA 02114, USA.
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22
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Liu M, Chung S, Shelness GS, Parks JS. Hepatic ABCA1 deficiency is associated with delayed apolipoprotein B secretory trafficking and augmented VLDL triglyceride secretion. Biochim Biophys Acta Mol Cell Biol Lipids 2017; 1862:1035-1043. [PMID: 28694219 DOI: 10.1016/j.bbalip.2017.07.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 06/30/2017] [Accepted: 07/05/2017] [Indexed: 11/30/2022]
Abstract
ATP binding cassette transporter A1 (ABCA1) is a membrane transporter that facilitates nascent HDL formation. Tangier disease subjects with complete ABCA1 deficiency have <5% of normal levels of plasma HDL, elevated triglycerides (TGs), and defective vesicular trafficking in fibroblasts and macrophages. Hepatocyte-specific ABCA1 knockout mice (HSKO) have a similar lipid phenotype with 20% of normal plasma HDL levels and a two-fold elevation of plasma TGs due to hepatic overproduction of large, triglyceride-enriched VLDL. We hypothesized that enhanced VLDL TG secretion in the absence of hepatocyte ABCA1 is due to altered intracellular trafficking of apolipoprotein B (apoB), resulting in augmented TG addition to nascent VLDL. We found that trafficking of newly synthesized apoB through the secretory pathway was delayed in ABCA1-silenced rat hepatoma cells and HSKO primary hepatocytes, relative to controls. Endoglycosidase H treatment of cellular apoB revealed a likely delay in apoB trafficking in post-ER compartments. The reduced rate of protein trafficking was also observed for an adenoviral-expressed GPI-linked fluorescent fusion protein, but not albumin, suggesting a selective delay of secretory cargoes in the absence of hepatocyte ABCA1. Our results suggest an important role for hepatic ABCA1 in regulating secretory trafficking and modulating VLDL expansion during the TG accretion phase of hepatic lipoprotein particle assembly.
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Affiliation(s)
- Mingxia Liu
- Department of Internal Medicine-Section on Molecular Medicine, Wake Forest School of Medicine, Winston-Salem, NC, USA.
| | - Soonkyu Chung
- Department of Internal Medicine-Section on Molecular Medicine, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Gregory S Shelness
- Department of Internal Medicine-Section on Molecular Medicine, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - John S Parks
- Department of Internal Medicine-Section on Molecular Medicine, Wake Forest School of Medicine, Winston-Salem, NC, USA; Department of Biochemistry, Wake Forest School of Medicine, Winston-Salem, NC, USA
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Walsh MT, Hussain MM. Targeting microsomal triglyceride transfer protein and lipoprotein assembly to treat homozygous familial hypercholesterolemia. Crit Rev Clin Lab Sci 2016; 54:26-48. [PMID: 27690713 DOI: 10.1080/10408363.2016.1221883] [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] [Indexed: 01/25/2023]
Abstract
Homozygous familial hypercholesterolemia (HoFH) is a polygenic disease arising from defects in the clearance of plasma low-density lipoprotein (LDL), which results in extremely elevated plasma LDL cholesterol (LDL-C) and increased risk of atherosclerosis, coronary heart disease, and premature death. Conventional lipid-lowering therapies, such as statins and ezetimibe, are ineffective at lowering plasma cholesterol to safe levels in these patients. Other therapeutic options, such as LDL apheresis and liver transplantation, are inconvenient, costly, and not readily available. Recently, lomitapide was approved by the Federal Drug Administration as an adjunct therapy for the treatment of HoFH. Lomitapide inhibits microsomal triglyceride transfer protein (MTP), reduces lipoprotein assembly and secretion, and lowers plasma cholesterol levels by over 50%. Here, we explain the steps involved in lipoprotein assembly, summarize the role of MTP in lipoprotein assembly, explore the clinical and molecular basis of HoFH, and review pre-clinical studies and clinical trials with lomitapide and other MTP inhibitors for the treatment of HoFH. In addition, ongoing research and new approaches underway for better treatment modalities are discussed.
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Affiliation(s)
- Meghan T Walsh
- a School of Graduate Studies, Molecular and Cell Biology Program, State University of New York Downstate Medical Center , Brooklyn , NY , USA.,b Department of Cell Biology , State University of New York Downstate Medical Center , Brooklyn , NY , USA
| | - M Mahmood Hussain
- b Department of Cell Biology , State University of New York Downstate Medical Center , Brooklyn , NY , USA.,c Department of Pediatrics , SUNY Downstate Medical Center , Brooklyn , NY , USA.,d VA New York Harbor Healthcare System , Brooklyn , NY , USA , and.,e Winthrop University Hospital , Mineola , NY , USA
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Murakami M, Tognini P, Liu Y, Eckel-Mahan KL, Baldi P, Sassone-Corsi P. Gut microbiota directs PPARγ-driven reprogramming of the liver circadian clock by nutritional challenge. EMBO Rep 2016; 17:1292-303. [PMID: 27418314 DOI: 10.15252/embr.201642463] [Citation(s) in RCA: 106] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Accepted: 06/22/2016] [Indexed: 12/20/2022] Open
Abstract
The liver circadian clock is reprogrammed by nutritional challenge through the rewiring of specific transcriptional pathways. As the gut microbiota is tightly connected to host metabolism, whose coordination is governed by the circadian clock, we explored whether gut microbes influence circadian homeostasis and how they distally control the peripheral clock in the liver. Using fecal transplant procedures we reveal that, in response to high-fat diet, the gut microbiota drives PPARγ-mediated activation of newly oscillatory transcriptional programs in the liver. Moreover, antibiotics treatment prevents PPARγ-driven transcription in the liver, underscoring the essential role of gut microbes in clock reprogramming and hepatic circadian homeostasis. Thus, a specific molecular signature characterizes the influence of the gut microbiome in the liver, leading to the transcriptional rewiring of hepatic metabolism.
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Affiliation(s)
- Mari Murakami
- Center for Epigenetics and Metabolism, Department of Biological Chemistry, U904 INSERM, University of California Irvine, Irvine, CA, USA
| | - Paola Tognini
- Center for Epigenetics and Metabolism, Department of Biological Chemistry, U904 INSERM, University of California Irvine, Irvine, CA, USA
| | - Yu Liu
- Institute for Genomics and Bioinformatics, School of Information and Computer Sciences, University of California Irvine, Irvine, CA, USA
| | - Kristin L Eckel-Mahan
- Center for Epigenetics and Metabolism, Department of Biological Chemistry, U904 INSERM, University of California Irvine, Irvine, CA, USA Center for Metabolic and Degenerative Diseases, Institute of Molecular Medicine, University of Texas Health Sciences Center, Houston, TX, USA
| | - Pierre Baldi
- Institute for Genomics and Bioinformatics, School of Information and Computer Sciences, University of California Irvine, Irvine, CA, USA
| | - Paolo Sassone-Corsi
- Center for Epigenetics and Metabolism, Department of Biological Chemistry, U904 INSERM, University of California Irvine, Irvine, CA, USA
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Zhang F, Xie D, Liang M, Xiong M. Functional Regression Models for Epistasis Analysis of Multiple Quantitative Traits. PLoS Genet 2016; 12:e1005965. [PMID: 27104857 PMCID: PMC4841563 DOI: 10.1371/journal.pgen.1005965] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Accepted: 03/08/2016] [Indexed: 12/02/2022] Open
Abstract
To date, most genetic analyses of phenotypes have focused on analyzing single traits or analyzing each phenotype independently. However, joint epistasis analysis of multiple complementary traits will increase statistical power and improve our understanding of the complicated genetic structure of the complex diseases. Despite their importance in uncovering the genetic structure of complex traits, the statistical methods for identifying epistasis in multiple phenotypes remains fundamentally unexplored. To fill this gap, we formulate a test for interaction between two genes in multiple quantitative trait analysis as a multiple functional regression (MFRG) in which the genotype functions (genetic variant profiles) are defined as a function of the genomic position of the genetic variants. We use large-scale simulations to calculate Type I error rates for testing interaction between two genes with multiple phenotypes and to compare the power with multivariate pairwise interaction analysis and single trait interaction analysis by a single variate functional regression model. To further evaluate performance, the MFRG for epistasis analysis is applied to five phenotypes of exome sequence data from the NHLBI’s Exome Sequencing Project (ESP) to detect pleiotropic epistasis. A total of 267 pairs of genes that formed a genetic interaction network showed significant evidence of epistasis influencing five traits. The results demonstrate that the joint interaction analysis of multiple phenotypes has a much higher power to detect interaction than the interaction analysis of a single trait and may open a new direction to fully uncovering the genetic structure of multiple phenotypes. The widely used statistical methods test interaction for single phenotype. However, we often observe pleotropic genetic interaction effects. The simultaneous gene-gene (GxG) interaction analysis of multiple complementary traits will increase statistical power to detect GxG interactions. Although GxG interactions play an important role in uncovering the genetic structure of complex traits, the statistical methods for detecting GxG interactions in multiple phenotypes remains less developed owing to its potential complexity. Therefore, we extend functional regression model from single variate to multivariate for simultaneous GxG interaction analysis of multiple correlated phenotypes. Large-scale simulations are conducted to evaluate Type I error rates for testing interaction between two genes with multiple phenotypes and to compare power with traditional multivariate pair-wise interaction analysis and single trait interaction analysis by a single variate functional regression model. To further evaluate performance, the MFRG for interaction analysis is applied to five phenotypes of exome sequence data from the NHLBI’s Exome Sequencing Project (ESP) to detect pleiotropic GxG interactions. 267 pairs of genes that formed a genetic interaction network showed significant evidence of interactions influencing five traits.
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Affiliation(s)
- Futao Zhang
- Department of Computer Science, College of Internet of Things, Hohai University, Changzhou, China
| | - Dan Xie
- College of Information Engineering, Hubei University of Chinese Medicine, Hubei, China
| | - Meimei Liang
- Institute of Bioinformatics, Zhejiang University, Hangzhou, Zhejiang, China
| | - Momiao Xiong
- Human Genetics Center, Division of Biostatistics, The University of Texas School of Public Health, Houston, Texas, United States of America
- * E-mail:
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26
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PPAR-β/δ activation promotes phospholipid transfer protein expression. Biochem Pharmacol 2015; 94:101-8. [DOI: 10.1016/j.bcp.2015.01.016] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Revised: 01/27/2015] [Accepted: 01/27/2015] [Indexed: 12/30/2022]
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Manchekar M, Liu Y, Sun Z, Richardson PE, Dashti N. Phospholipid transfer protein plays a major role in the initiation of apolipoprotein B-containing lipoprotein assembly in mouse primary hepatocytes. J Biol Chem 2015; 290:8196-205. [PMID: 25638820 DOI: 10.1074/jbc.m114.602748] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
In this study, we tested the hypothesis that phospholipid transfer protein (PLTP) is a plausible mediator of phospholipid (PL) transfer to the N-terminal 1000 residues of apoB (apoB:1000) leading to the initiation of apoB-containing lipoprotein assembly. To this end, primary hepatocytes from wild type (WT) and PLTP knock-out (KO) mice were transduced with adenovirus-apoB:1000 with or without co-transduction with adenovirus-PLTP, and the assembly and secretion of apoB:1000-containing lipoproteins were assessed. PLTP deficiency resulted in a 65 and 72% reduction in the protein and lipid content, respectively, of secreted apoB:1000-containing lipoproteins. Particles secreted by WT hepatocytes contained 69% PL, 9% diacylglycerol (DAG), and 23% triacylglycerol (TAG) with a stoichiometry of 46 PL, 6 DAG, and 15 TAG molecules per apoB:1000. PLTP absence drastically altered the lipid composition of apoB:1000 lipoproteins; these particles contained 46% PL, 13% DAG, and 41% TAG with a stoichiometry of 27 PL, 10 DAG, and 23 TAG molecules per apoB:1000. Reintroduction of Pltp gene into PLTP-KO hepatocytes stimulated the lipidation and secretion of apoB:1000-containing lipoproteins by ∼3-fold; the lipid composition and stoichiometry of these particles were identical to those secreted by WT hepatocytes. In contrast to the WT, apoB:1000 in PLTP-KO hepatocytes was susceptible to intracellular degradation predominantly in the post-endoplasmic reticulum, presecretory compartment. Reintroduction of Pltp gene into PLTP-KO hepatocytes restored the stability of apoB:1000. These results provide compelling evidence that in hepatocytes initial recruitment of PL by apoB:1000 leading to the formation of the PL-rich apoB-containing initiation complex is mediated to a large extent by PLTP.
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Affiliation(s)
- Medha Manchekar
- From the Department of Medicine, Division of Gerontology, Geriatrics, and Palliative Care, Basic Sciences Section, University of Alabama, Birmingham, Alabama 35294 and
| | - Yanwen Liu
- From the Department of Medicine, Division of Gerontology, Geriatrics, and Palliative Care, Basic Sciences Section, University of Alabama, Birmingham, Alabama 35294 and
| | - Zhihuan Sun
- From the Department of Medicine, Division of Gerontology, Geriatrics, and Palliative Care, Basic Sciences Section, University of Alabama, Birmingham, Alabama 35294 and
| | - Paul E Richardson
- the Department of Chemistry and Physics, Coastal Carolina University, Conway, South Carolina 29528
| | - Nassrin Dashti
- From the Department of Medicine, Division of Gerontology, Geriatrics, and Palliative Care, Basic Sciences Section, University of Alabama, Birmingham, Alabama 35294 and
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Abstract
High-density lipoprotein (HDL) is considered to be an anti-atherogenic lipoprotein moiety. Generation of genetically modified (total body and tissue-specific knockout) mouse models has significantly contributed to our understanding of HDL function. Here we will review data from knockout mouse studies on the importance of HDL's major alipoprotein apoA-I, the ABC transporters A1 and G1, lecithin:cholesterol acyltransferase, phospholipid transfer protein, and scavenger receptor BI for HDL's metabolism and its protection against atherosclerosis in mice. The initial generation and maturation of HDL particles as well as the selective delivery of its cholesterol to the liver are essential parameters in the life cycle of HDL. Detrimental atherosclerosis effects observed in response to HDL deficiency in mice cannot be solely attributed to the low HDL levels per se, as the low HDL levels are in most models paralleled by changes in non-HDL-cholesterol levels. However, the cholesterol efflux function of HDL is of critical importance to overcome foam cell formation and the development of atherosclerotic lesions in mice. Although HDL is predominantly studied for its atheroprotective action, the mouse data also suggest an essential role for HDL as cholesterol donor for steroidogenic tissues, including the adrenals and ovaries. Furthermore, it appears that a relevant interaction exists between HDL-mediated cellular cholesterol efflux and the susceptibility to inflammation, which (1) provides strong support for the novel concept that inflammation and metabolism are intertwining biological processes and (2) identifies the efflux function of HDL as putative therapeutic target also in other inflammatory diseases than atherosclerosis.
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Affiliation(s)
- Menno Hoekstra
- Division of Biopharmaceutics, Gorlaeus Laboratories, Leiden Academic Centre for Drug Research, Leiden University, Einsteinweg 55, 2333CC, Leiden, The Netherlands,
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Jiang H, Yazdanyar A, Lou B, Chen Y, Zhao X, Li R, Hoang Bui H, Kuo MS, Navab M, Qin S, Li Z, Jin W, Jiang XC. Adipocyte phospholipid transfer protein and lipoprotein metabolism. Arterioscler Thromb Vasc Biol 2014; 35:316-22. [PMID: 25477345 DOI: 10.1161/atvbaha.114.303764] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Phospholipid transfer protein (PLTP) is highly expressed in adipose tissues. Thus, the effect of adipose tissue PLTP on plasma lipoprotein metabolism was examined. APPROACH AND RESULTS We crossed PLTP-Flox-ΔNeo and adipocyte protein 2 (aP2)-Cre recombinase (Cre) transgenic mice to create PLTP-Flox-ΔNeo/aP2-Cre mice that have a 90 and a 60% reduction in PLTP mRNA in adipose tissue and macrophages, respectively. PLTP ablation resulted in a significant reduction in plasma PLTP activity (22%), high-density lipoprotein-cholesterol (21%), high-density lipoprotein-phospholipid (20%), and apolipoprotein A-I (33%) levels, but had no effect on nonhigh-density lipoprotein levels in comparison with those of PLTP-Flox-ΔNeo controls. To eliminate possible effects of PLTP ablation by macrophages, we lethally irradiated PLTP-Flox-ΔNeo/aP2-Cre mice and PLTP-Flox-ΔNeo mice, and then transplanted wild-type mouse bone marrow into them to create wild-type→PLTP-Flox-ΔNeo/aP2-Cre and wild-type→PLTP-Flox-ΔNeo mice. Thus, we constructed a mouse model (wild-type→PLTP-Flox-ΔNeo/aP2-Cre) with PLTP deficiency in adipocytes but not in macrophages. These knockout mice also showed significant decreases in plasma PLTP activity (19%) and cholesterol (18%), phospholipid (17%), and apolipoprotein A-I (26%) levels. To further investigate the mechanisms behind the reduction in plasma apolipoprotein A-I and high-density lipoprotein lipids, we measured apolipoprotein A-I-mediated cholesterol efflux in adipose tissue explants and found that endogenous and exogenous PLTP significantly increased cholesterol efflux from the explants. CONCLUSIONS Adipocyte PLTP plays a small but significant role in plasma PLTP activity and promotes cholesterol efflux from adipose tissues.
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Affiliation(s)
- Hui Jiang
- From the Department of Cell Biology, State University of New York, Downstate Medical Center, Brooklyn (H.J., A.Y., Y.C., X.Z., R.L., Z.L., W.J., X.C.J.); Fudan University, Shanghai, China (B.L., Y.C.); Molecular and Cellular Cardiology Program, VA New York Harbor Healthcare System, New York (Z.L., X.C.J); Institute of Atherosclerosis, Taishan Medical University, Taian, China (X.Z., S.Q.); Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN (H.H.B., M.S.K.); and Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA (M.N.)
| | - Amirfarbod Yazdanyar
- From the Department of Cell Biology, State University of New York, Downstate Medical Center, Brooklyn (H.J., A.Y., Y.C., X.Z., R.L., Z.L., W.J., X.C.J.); Fudan University, Shanghai, China (B.L., Y.C.); Molecular and Cellular Cardiology Program, VA New York Harbor Healthcare System, New York (Z.L., X.C.J); Institute of Atherosclerosis, Taishan Medical University, Taian, China (X.Z., S.Q.); Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN (H.H.B., M.S.K.); and Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA (M.N.)
| | - Bin Lou
- From the Department of Cell Biology, State University of New York, Downstate Medical Center, Brooklyn (H.J., A.Y., Y.C., X.Z., R.L., Z.L., W.J., X.C.J.); Fudan University, Shanghai, China (B.L., Y.C.); Molecular and Cellular Cardiology Program, VA New York Harbor Healthcare System, New York (Z.L., X.C.J); Institute of Atherosclerosis, Taishan Medical University, Taian, China (X.Z., S.Q.); Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN (H.H.B., M.S.K.); and Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA (M.N.)
| | - Yunqin Chen
- From the Department of Cell Biology, State University of New York, Downstate Medical Center, Brooklyn (H.J., A.Y., Y.C., X.Z., R.L., Z.L., W.J., X.C.J.); Fudan University, Shanghai, China (B.L., Y.C.); Molecular and Cellular Cardiology Program, VA New York Harbor Healthcare System, New York (Z.L., X.C.J); Institute of Atherosclerosis, Taishan Medical University, Taian, China (X.Z., S.Q.); Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN (H.H.B., M.S.K.); and Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA (M.N.)
| | - Xiaomin Zhao
- From the Department of Cell Biology, State University of New York, Downstate Medical Center, Brooklyn (H.J., A.Y., Y.C., X.Z., R.L., Z.L., W.J., X.C.J.); Fudan University, Shanghai, China (B.L., Y.C.); Molecular and Cellular Cardiology Program, VA New York Harbor Healthcare System, New York (Z.L., X.C.J); Institute of Atherosclerosis, Taishan Medical University, Taian, China (X.Z., S.Q.); Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN (H.H.B., M.S.K.); and Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA (M.N.)
| | - Ruohan Li
- From the Department of Cell Biology, State University of New York, Downstate Medical Center, Brooklyn (H.J., A.Y., Y.C., X.Z., R.L., Z.L., W.J., X.C.J.); Fudan University, Shanghai, China (B.L., Y.C.); Molecular and Cellular Cardiology Program, VA New York Harbor Healthcare System, New York (Z.L., X.C.J); Institute of Atherosclerosis, Taishan Medical University, Taian, China (X.Z., S.Q.); Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN (H.H.B., M.S.K.); and Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA (M.N.)
| | - Hai Hoang Bui
- From the Department of Cell Biology, State University of New York, Downstate Medical Center, Brooklyn (H.J., A.Y., Y.C., X.Z., R.L., Z.L., W.J., X.C.J.); Fudan University, Shanghai, China (B.L., Y.C.); Molecular and Cellular Cardiology Program, VA New York Harbor Healthcare System, New York (Z.L., X.C.J); Institute of Atherosclerosis, Taishan Medical University, Taian, China (X.Z., S.Q.); Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN (H.H.B., M.S.K.); and Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA (M.N.)
| | - Ming-Shang Kuo
- From the Department of Cell Biology, State University of New York, Downstate Medical Center, Brooklyn (H.J., A.Y., Y.C., X.Z., R.L., Z.L., W.J., X.C.J.); Fudan University, Shanghai, China (B.L., Y.C.); Molecular and Cellular Cardiology Program, VA New York Harbor Healthcare System, New York (Z.L., X.C.J); Institute of Atherosclerosis, Taishan Medical University, Taian, China (X.Z., S.Q.); Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN (H.H.B., M.S.K.); and Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA (M.N.)
| | - Mohamad Navab
- From the Department of Cell Biology, State University of New York, Downstate Medical Center, Brooklyn (H.J., A.Y., Y.C., X.Z., R.L., Z.L., W.J., X.C.J.); Fudan University, Shanghai, China (B.L., Y.C.); Molecular and Cellular Cardiology Program, VA New York Harbor Healthcare System, New York (Z.L., X.C.J); Institute of Atherosclerosis, Taishan Medical University, Taian, China (X.Z., S.Q.); Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN (H.H.B., M.S.K.); and Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA (M.N.)
| | - Shucun Qin
- From the Department of Cell Biology, State University of New York, Downstate Medical Center, Brooklyn (H.J., A.Y., Y.C., X.Z., R.L., Z.L., W.J., X.C.J.); Fudan University, Shanghai, China (B.L., Y.C.); Molecular and Cellular Cardiology Program, VA New York Harbor Healthcare System, New York (Z.L., X.C.J); Institute of Atherosclerosis, Taishan Medical University, Taian, China (X.Z., S.Q.); Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN (H.H.B., M.S.K.); and Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA (M.N.)
| | - Zhiqiang Li
- From the Department of Cell Biology, State University of New York, Downstate Medical Center, Brooklyn (H.J., A.Y., Y.C., X.Z., R.L., Z.L., W.J., X.C.J.); Fudan University, Shanghai, China (B.L., Y.C.); Molecular and Cellular Cardiology Program, VA New York Harbor Healthcare System, New York (Z.L., X.C.J); Institute of Atherosclerosis, Taishan Medical University, Taian, China (X.Z., S.Q.); Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN (H.H.B., M.S.K.); and Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA (M.N.)
| | - Weijun Jin
- From the Department of Cell Biology, State University of New York, Downstate Medical Center, Brooklyn (H.J., A.Y., Y.C., X.Z., R.L., Z.L., W.J., X.C.J.); Fudan University, Shanghai, China (B.L., Y.C.); Molecular and Cellular Cardiology Program, VA New York Harbor Healthcare System, New York (Z.L., X.C.J); Institute of Atherosclerosis, Taishan Medical University, Taian, China (X.Z., S.Q.); Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN (H.H.B., M.S.K.); and Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA (M.N.)
| | - Xian-Cheng Jiang
- From the Department of Cell Biology, State University of New York, Downstate Medical Center, Brooklyn (H.J., A.Y., Y.C., X.Z., R.L., Z.L., W.J., X.C.J.); Fudan University, Shanghai, China (B.L., Y.C.); Molecular and Cellular Cardiology Program, VA New York Harbor Healthcare System, New York (Z.L., X.C.J); Institute of Atherosclerosis, Taishan Medical University, Taian, China (X.Z., S.Q.); Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN (H.H.B., M.S.K.); and Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA (M.N.).
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Specific collagen XVIII isoforms promote adipose tissue accrual via mechanisms determining adipocyte number and affect fat deposition. Proc Natl Acad Sci U S A 2014; 111:E3043-52. [PMID: 25024173 DOI: 10.1073/pnas.1405879111] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Collagen XVIII is an evolutionary conserved ubiquitously expressed basement membrane proteoglycan produced in three isoforms via two promoters (P). Here, we assess the function of the N-terminal, domain of unknown function/frizzled-like sequences unique to medium/long collagen XVIII by creating P-specific null mice. P2-null mice, which only produce short collagen XVIII, developed reduced bulk-adiposity, hepatic steatosis, and hypertriglyceridemia. These abnormalities did not develop in P1-null mice, which produce medium/long collagen XVIII. White adipose tissue samples from P2-null mice contain larger reserves of a cell population enriched in early adipocyte progenitors; however, their embryonic fibroblasts had ∼ 50% lower adipocyte differentiation potential. Differentiating 3T3-L1 fibroblasts into mature adipocytes produced striking increases in P2 gene-products and dramatic falls in P1-transcribed mRNA, whereas Wnt3a-induced dedifferentiation of mature adipocytes produced reciprocal changes in P1 and P2 transcript levels. P2-derived gene-products containing frizzled-like sequences bound the potent adipogenic inhibitor, Wnt10b, in vitro. Previously, we have shown that these same sequences bind Wnt3a, inhibiting Wnt3a-mediated signaling. P2-transcript levels in visceral fat were positively correlated with serum free fatty acid levels, suggesting that collagen α1 (XVIII) expression contributes to regulation of adipose tissue metabolism in visceral obesity. Medium/long collagen XVIII is deposited in the Space of Disse, and interaction between hepatic apolipoprotein E and this proteoglycan is lost in P2-null mice. These results describe a previously unidentified extracellular matrix-directed mechanism contributing to the control of the multistep adipogenic program that determines the number of precursors committing to adipocyte differentiation, the maintenance of the differentiated state, and the physiological consequences of its impairment on ectopic fat deposition.
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Hepatic overexpression of the prodomain of furin lessens progression of atherosclerosis and reduces vascular remodeling in response to injury. Atherosclerosis 2014; 236:121-30. [PMID: 25026302 DOI: 10.1016/j.atherosclerosis.2014.06.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/26/2013] [Revised: 06/16/2014] [Accepted: 06/18/2014] [Indexed: 11/24/2022]
Abstract
OBJECTIVE Atherosclerosis is a complex disease, involving elevated LDL-c, lipid accumulation in the blood vessel wall, foam cell formation and vascular dysfunction. Lowering plasma LDL-c is the cornerstone of current management of cardiovascular disease. However, new approaches which reduce plasma LDL-c and lessen the pathological vascular remodeling occurring in the disease should also have therapeutic value. Previously, we found that overexpression of profurin, the 83-amino acid prodomain of the proprotein convertase furin, lowered plasma HDL levels in wild-type mice. The question that remained was whether it had effects on apolipoprotein B (ApoB)-containing lipoproteins. METHODS Adenovirus mediated overexpression of hepatic profurin in Ldlr(-/-)mice and wild-type mice were used to evaluate effects of profurin on ApoB-containing lipoproteins, atherosclerosis and vascular remodeling. RESULTS Hepatic profurin overexpression resulted in a significant reduction in atherosclerotic lesion development in Ldlr(-/-)mice and a robust reduction in plasma LDL-c. Metabolic studies revealed lower secretion of ApoB and triglycerides in VLDL particles. Mechanistic studies showed that in the presence of profurin, hepatic ApoB, mainly ApoB100, was degraded by proteasomes. There was no effect on ApoB mRNA expression. Importantly, short-term hepatic profurin overexpression did not result in hepatic lipid accumulation. Blood vessel wall thickening caused by either wire-induced femoral artery injury or common carotid artery ligation was reduced. Profurin expression inhibited proliferation and migration in vascular smooth muscle cells in vitro. CONCLUSION These results indicate that a profurin-based therapy has the potential to treat atherosclerosis by improving metabolic lipid profiles and reducing both atherosclerotic lesion development and pathological vascular remodeling.
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Sun X, Luo W, Tan X, Li Q, Zhao Y, Zhong W, Sun X, Brouwer C, Zhou Z. Increased plasma corticosterone contributes to the development of alcoholic fatty liver in mice. Am J Physiol Gastrointest Liver Physiol 2013; 305:G849-61. [PMID: 24113770 PMCID: PMC3882437 DOI: 10.1152/ajpgi.00139.2013] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Ethanol ingestion increases endogenous glucocorticoid levels in both humans and rodents. The present study aimed to define a mechanistic link between the increased glucocorticoids and alcoholic fatty liver in mice. Plasma corticosterone levels were not affected in mice on a 2-wk ethanol diet regimen but significantly increased upon 4 wk of ethanol ingestion. Accordingly, hepatic triglyceride levels were not altered after 2 wk of ethanol ingestion but were elevated at 4 wk. Based on the observation that 2 wk of ethanol ingestion did not significantly increase endogenous corticosterone levels, we administered exogenous glucocorticoids along with the 2-wk ethanol treatment to determine whether the elevated glucocorticoid contributes to the development of alcoholic fatty liver. Mice were subjected to ethanol feeding for 2 wk with or without dexamethasone administration. Hepatic triglyceride contents were not affected by either ethanol or dexamethasone alone but were significantly increased by administration of both. Microarray and protein level analyses revealed two distinct changes in hepatic lipid metabolism in mice administered with both ethanol and dexamethasone: accelerated triglyceride synthesis by diacylglycerol O-acyltransferase 2 and suppressed fatty acid β-oxidation by long-chain acyl-CoA synthetase 1, carnitine palmitoyltransferase 1a, and acyl-CoA oxidase 1. A reduction of hepatic peroxisome proliferation activator receptor-α (PPAR-α) was associated with coadministration of ethanol and dexamethasone. These findings suggest that increased glucocorticoid levels may contribute to the development of alcoholic fatty liver, at least partially, through hepatic PPAR-α inactivation.
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Affiliation(s)
- Xiuhua Sun
- Ctr. for Translational & Biomedical Research, The Univ. of North Carolina at Greensboro, North Carolina Research Campus, Kannapolis, NC 28081.
| | - Weijun Luo
- 3Bioinformatics Services Division, UNC-Charlotte, ,4Center for Excellence in Post-Harvest Technologies, North Carolina Agricultural and Technical State University, North Carolina Research Campus, Kannapolis;
| | - Xiaobing Tan
- 1Center for Translational and Biomedical Research,
| | - Qiong Li
- 1Center for Translational and Biomedical Research,
| | - Yantao Zhao
- 5Department of Bioinformatics and Genomics, The University of North Carolina at Charlotte, North Carolina
| | - Wei Zhong
- 1Center for Translational and Biomedical Research,
| | - Xinguo Sun
- 1Center for Translational and Biomedical Research,
| | - Cory Brouwer
- 3Bioinformatics Services Division, UNC-Charlotte, ,4Center for Excellence in Post-Harvest Technologies, North Carolina Agricultural and Technical State University, North Carolina Research Campus, Kannapolis;
| | - Zhanxiang Zhou
- 1Center for Translational and Biomedical Research, ,2Department of Nutrition, The University of North Carolina at Greensboro,
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Yazdanyar A, Quan W, Jin W, Jiang XC. Liver-specific phospholipid transfer protein deficiency reduces high-density lipoprotein and non-high-density lipoprotein production in mice. Arterioscler Thromb Vasc Biol 2013; 33:2058-64. [PMID: 23846500 DOI: 10.1161/atvbaha.113.301628] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE The liver is one of the critical organs for lipoprotein metabolism and a major source for phospholipid transfer protein (PLTP) expression. The effect of liver-specific PLTP deficiency on plasma lipoprotein production and metabolism in mice was investigated. APPROACH AND RESULTS We created a liver-specific PLTP-deficient mouse model. We measured plasma high-density lipoprotein (HDL) and apolipoprotein B (apoB)-containing lipoprotein (or non-HDL) levels and their production rates. We found that hepatic ablation of PLTP leads to a significant decrease in plasma PLTP activity, HDL lipids, non-HDL lipids, apoAI, and apoB levels. In addition, nuclear magnetic resonance examination of lipoproteins showed that the deficiency decreases HDL and apoB-containing lipoprotein particle numbers, as well as very low-density lipoprotein particle size, which was confirmed by electron microscopy. Moreover, HDL particles from the deficient mice are lipid-poor ones. To unravel the mechanism, we evaluated the apoB and triglyceride production rates. We found that hepatic PLTP deficiency significantly decreases apoB and triglyceride secretion rates. To investigate the role of liver PLTP on HDL production, we set up primary hepatocyte culture studies and found that the PLTP-deficient hepatocytes produce less nascent HDL. Furthermore, we found that exogenous PLTP promotes nascent HDL production through an ATP-binding cassette A 1-mediated pathway. CONCLUSIONS Liver-specific PLTP deficiency significantly reduces plasma HDL and apoB-containing lipoprotein levels. Reduction of production rates of both particles is one of the mechanisms.
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Affiliation(s)
- Amirfarbod Yazdanyar
- Department of Cell Biology, State University of New York Downstate Medical Center, Brooklyn, NY 11203, USA
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Phospholipid transfer protein, an emerging cardiometabolic risk marker: Is it time to intervene? Atherosclerosis 2013; 228:38-41. [DOI: 10.1016/j.atherosclerosis.2013.01.043] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Accepted: 01/28/2013] [Indexed: 12/13/2022]
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Elevated expression of PLTP is atherogenic in apolipoprotein E deficient mice. Atherosclerosis 2012; 227:37-42. [PMID: 23313246 DOI: 10.1016/j.atherosclerosis.2012.11.022] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Revised: 11/01/2012] [Accepted: 11/25/2012] [Indexed: 11/23/2022]
Abstract
OBJECTIVE Plasma phospholipid transfer protein (PLTP) plays a key role in lipoprotein metabolism. Its exact function in the development of atherosclerosis is still under debate however. We studied the effect of elevated PLTP expression in one of the most commonly used models of atherosclerosis, the ApoE deficient mouse. METHODS Experiment 1: Plasma PLTP activity, total cholesterol, HDL cholesterol and atherosclerosis development was measured in ApoE deficient mice with or without elevated expression of PLTP. Experiment 2: The same parameters were measured in ApoE deficient mice after bone marrow transplantation from wild type mice or mice with elevated PLTP expression. Experiment 3: Similar to experiment 2, but using donor mice with an ApoE deficient background. RESULTS Experiment 1: ApoE deficient mice have more than two times more atherosclerosis when overexpressing PLTP and a strongly decreased plasma level of HDL. Experiment 2: Bone marrow transplantation with ApoE proficient cells results in a strong reduction of plasma cholesterol in ApoE deficient acceptor mice. Still, elevated PLTP in bone marrow derived cells evoke a reduction of HDL cholesterol and increased atherosclerosis. Experiment 3: Bone marrow transplantation with ApoE deficient cells results in much higher cholesterol levels, but here too HDL cholesterol levels are reduced and atherosclerosis increased. CONCLUSION In all the models with ApoE deficiency, elevated PLTP expression causes higher levels of diet-induced atherosclerosis coinciding with decreased plasma levels of HDL cholesterol.
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Jiang XC, Jin W, Hussain MM. The impact of phospholipid transfer protein (PLTP) on lipoprotein metabolism. Nutr Metab (Lond) 2012; 9:75. [PMID: 22897926 PMCID: PMC3495888 DOI: 10.1186/1743-7075-9-75] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2012] [Accepted: 06/30/2012] [Indexed: 02/05/2023] Open
Abstract
It has been reported that phospholipid transfer protein (PLTP) is an independent risk factor for human coronary artery disease. In mouse models, it has been demonstrated that PLTP overexpression induces atherosclerosis, while its deficiency reduces it. PLTP is considered a promising target for pharmacological intervention to treat atherosclerosis. However, we must still answer a number of questions before its pharmaceutical potential can be fully explored. In this review, we summarized the recent progresses made in the PLTP research field and focused on its effect on apoB-containing- triglyceride-rich particle and HDL metabolism.
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Affiliation(s)
- Xian-Cheng Jiang
- Department of Cell Biology, Downstate Medical Center, State University of New York, 450 Clarkson Ave,, Box 5, Brooklyn, NY, 11203, USA.
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